237 results on '"Chan Hong Park"'
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102. Crustal analysis of the Ulleung Basin in the East Sea (Japan Sea) from enhanced gravity mapping
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Chan Hong Park, Jeong Woo Kim, Ralph R. B. von Frese, D. R. Roman, and Nobuhiro Isezaki
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Underplating ,geography ,geography.geographical_feature_category ,Seamount ,Crust ,Oceanography ,Gravity anomaly ,Mantle (geology) ,Geophysics ,Geochemistry and Petrology ,Oceanic crust ,Bathymetry ,Geology ,Seismology ,Terrane - Abstract
To facilitate geological analyses of the Ulleung Basin in the East Sea (Japan Sea) between Korea and Japan, shipborne and satellite altimetry-derived gravity data are combined to derive a regionally coherent anomaly field. The 2-min gridded satellite altimetry-based gravity predicted by Sandwell and Smith [Sandwell DT, Smith WHF (1997) J Geophys Res 102(B5):10,039–10,054] are used for making cross-over adjustments that reduce the errors between track segments and at the cross-over points of shipborne gravity profiles. Relative to the regionally more homogeneous satellite gravity anomalies, the longer wavelength components of the shipborne anomalies are significantly improved with minimal distortion of their shorter wavelength components. The resulting free-air gravity anomaly map yields a more coherent integration of short and long wavelength anomalies compared to that obtained from either the shipborne or satellite data sets separately. The derived free-air anomalies range over about 140 mGals or more in amplitude and regionally correspond with bathymetric undulations in the Ulleung Basin. The gravity lows and highs along the basin’s margin indicate the transition from continental to oceanic crust. However, in the northeastern and central Ulleung Basin, the negative regional correlation between the central gravity high and bathymetric low suggests the presence of shallow denser mantle beneath thinned oceanic crust. A series of gravity highs mark seamounts or volcanic terranes from the Korean Plateau to Oki Island. Gravity modeling suggests underplating by mafic igneous rocks of the northwestern margin of the Ulleung Basin and the transition between continental and oceanic crust. The crust of the central Ulleung Basin is about a 14–15 km thick with a 4–5 km thick sediment cover. It may also include a relatively weakly developed buried fossil spreading ridge with approximately 2 km of relief.
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- 2006
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103. Efficacy of transforaminal laser annuloplasty versus intradiscal radiofrequency annuloplasty for discogenic low back pain.
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Chan Hong Park, Kyoung Kyu Lee, and Sang Ho Lee
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LUMBAR pain , *ANALGESIA , *LASERS , *PAIN management , *THERAPEUTICS - Abstract
Background: Discogenic pain is a common cause of disability and is assumed to be a major cause of nonspecific low back pain. Various treatment methods have been used for the treatment of discogenic pain. This study was conducted to compare the therapeutic success of radiofrequency (an intradiscal procedure) and laser annuloplasty (both an intradiscal and extradiscal procedure). Methods: This single-center study included 80 patients and followed them for 6 months. Transforaminal laser annuloplasty (TFLA, 37 patients) or intradiscal radiofrequency annuloplasty (IDRA, 43 patients) was performed. The main outcomes included pain scores, determined by the numeric rating scale (NRS), and Oswestry disability index (ODI), at pre-treatment and at post-treatment months 1 and 6. Results: The patients were grouped according to procedure. In all procedures, NRS and ODI scores were significantly decreased over time. Mean post-treatment pain scores at months 1 and 6 were significantly lower (P < 0.01) in both groups, and between-group differences were not significant. The ODI score was also significantly decreased compared with baseline. Among patients undergoing TFLA, 70.3% (n = 26) reported pain relief (NRS scores < 50% of baseline) at post-treatment 6 months, vs. 58.1% (n = 25) of those undergoing IDRA. There were no statistically significant differences between the groups in ODI reduction of > 40%. Conclusions: Our results indicate that annuloplasty is a reasonable treatment option for carefully selected patients with lower back and radicular pain of discogenic origin, and TFLA might be superior to IDRA in patients with discogenic low back pain. (Korean J Pain 2019; 32: 113-9) [ABSTRACT FROM AUTHOR]
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- 2019
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104. Lumbar Transforaminal Epidural Blood Patch
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Chan Hong Park and Sang-Ho Lee
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Epidural blood patch ,medicine.medical_specialty ,business.industry ,Epidural steroid injection ,medicine.medical_treatment ,General Medicine ,Bed rest ,Spinal pain ,Epidural space ,Surgery ,Anesthesiology and Pain Medicine ,Lumbar ,medicine.anatomical_structure ,Intravenous fluid ,Anesthesia ,medicine ,Neurology (clinical) ,Salt intake ,business - Abstract
Dear Editor, We present a case of successful treatment of post-dural puncture headache (PDPH) using a lumbar transforaminal epidural blood patch (TFEBP). Although epidural steroid injections are frequently used to manage lumbar spinal pain, a number of complications may arise ⇓. Among complications, PDPH is a painful one. The incidence of dural puncture ranges from 0.16–1.3%, but PDPH develops in 16–86% of patients after attempted epidural block with large-bore needles ⇓. A lumbar transforaminal epidural steroid injection (TFESI) may pose less risk than interlaminar injections ⇓ but still not free of minor complications ⇓. Treatment of PDPH varies. Standard conservative therapy (bed rest, oral hydration, increased salt intake) is appropriate initially, and other innocuous remedies (intravenous fluid, caffeine, and the use of abdominal truss) have been suggested ⇓. However, when conservative therapy fails, epidural blood patch (EBP) is a reasonable alternative. Generally, EBP calls for interlaminar approach, with injection of sterile autologous blood (10–30 mL) into epidural space ⇓. In our patient, PDPH occurred subsequent to lumbar TFESI and was successfully …
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- 2013
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105. A low-power cmos bluetooth rf transceiver with a digital offset canceling dll-based gfsk demodulator
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Chan-Hong Park, Sung-Ho Wang, Sangjin Byun, Yongchul Song, C. Conroy, and Beomsup Kim
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Engineering ,Frequency-shift keying ,business.industry ,Transmitter ,Electrical engineering ,law.invention ,Bluetooth ,CMOS ,Direct digital synthesizer ,law ,Hardware_INTEGRATEDCIRCUITS ,Electronic engineering ,Frequency offset ,Demodulation ,Electrical and Electronic Engineering ,Transceiver ,business - Abstract
This paper presents a fully integrated 0.18-/spl mu/m CMOS Bluetooth transceiver. The chip consumes 33 mA in receive mode and 25 mA in transmit mode from a 3-V system supply. The receiver uses a low-IF (3-MHz) architecture, and the transmitter uses a direct modulation with ROM-based Gaussian low-pass filter and I/Q direct digital frequency synthesizer for high level of integration and low power consumption. A new frequency shift keying demodulator based on a delay-locked loop with a digital frequency offset canceller is proposed. The demodulator operates without harmonic distortion, handles up to /spl plusmn/160-kHz frequency offset, and consumes only 2 mA from a 1.8-V supply. The receiver dynamic range is from -78 dBm to -16 dBm at 0.1% bit-error rate, and the transmitter delivers a maximum of 0 dBm with 20-dB digital power control capability.
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- 2003
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106. Sacral Nerve Stimulation Through the Sacral Hiatus
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Bong Il Kim and Chan Hong Park
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musculoskeletal diseases ,medicine.medical_specialty ,spinal cord stimulation ,business.industry ,Brief Report ,anterograde ,Stimulation ,Spinal cord stimulation ,Anatomy ,musculoskeletal system ,medicine.disease ,digestive system diseases ,Surgery ,body regions ,stomatognathic diseases ,Anesthesiology and Pain Medicine ,medicine.anatomical_structure ,Sacral nerve root ,Sacral nerve stimulation ,medicine ,Retrograde approach ,sacral nerve stimulation ,business ,Sacral hiatus ,Irritable bowel syndrome - Abstract
Sacral nerve stimulation through the retrograde approach has been used for peroneal or irritable bowel syndrome through the retrograde approach. However, several reasons, lead could not be advanced down ward. In this case, anterograde sacral nerve stimulation through the sacral hiatus could be used. The aim of this report is to present of technique of sacral nerve root stimulation through the sacral hiatus approach.
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- 2012
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107. Geomorphology and Volcaniclastic Deposits around Dokdo: Dokdo Caldera
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Sik Huh, Dae Kyo Cheong, Chan Hong Park, Jong Hwa Chun, and Sang Joon Han
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Fluid Flow and Transfer Processes ,geography ,geography.geographical_feature_category ,Pyroclastic rock ,Geology ,Ocean Engineering ,Aquatic Science ,Lapilli ,Sedimentary depositional environment ,Volcano ,Pyroclastic surge ,Breccia ,Subaerial ,Caldera ,Geomorphology - Abstract
Detailed investigations on both submarine and subaerial volcaniclastic deposits around Dokdo were carried out to identify geomorphologic characteristics, stratigraphy, and associated depositional processes of Dokdo caldera. Dokdo volcano has a gently sloping summit (about 11km in diameter) and relatively steep slope (basal diameter is about 20-25 km) rising above sea level at about 2,270m. We found ragged, elliptical-form of Dokdo caldera with a diameter of about 2km estimated by Chirp (3-11 kHz) sub-bottom profile data and side scan sonar data for the central summit area of Dokdo volcano. We interpreted that the volcaniclastic deposits of Dokdo unconformably consist of the Seodo (west islet) and the Dongdo(east islet) formations based on internal structure, constituent mineral composition, and bedding morphology. The Seodo Formation mainly consisted of massive or inversely graded trachytic breccias (Unit S-I), overlain by fine-grained tuff (Unit S-II), which is probably supplied by mass-wasting processes resulting from Dokdo caldera collapse. The Dongdo Formation consists of alternated units of stratified lapilli tuff and inversely graded basaltic breccia (Unit D-I, Unit D-III, and Unit D-V), and massive to undulatory-bedded basaltic tuff breccias (Unit D-II and Unit D-IV) formed by a repetitive pyroclastic surge and reworking processes. Although, two islets of Dokdo are geographically near each other, they have different formations reflecting their different depositional processes and eruptive stages.
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- 2002
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108. Design of a Water Sports Kayak Using Collaborative Filtering
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Chan-Hong Park and Seong Hyeon Kyeong
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Engineering ,Multimedia ,business.industry ,Collaborative filtering ,Recommender system ,business ,computer.software_genre ,computer - Published
- 2014
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109. Thermogram in spinal cord stimulation with complex regional pain syndrome and a review of the literature
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Matthew Ranson, Chan Hong Park, Jason Ravanbakht, Garlon Lee Campbell, and Billy K. Huh
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medicine.medical_specialty ,integumentary system ,business.industry ,General Medicine ,Spinal cord stimulation ,Blood flow ,medicine.disease ,Microcirculation ,Surgery ,Anesthesiology and Pain Medicine ,Complex regional pain syndrome ,nervous system ,Neurology ,Anesthesia ,Thermographic imaging ,Medicine ,Pink color ,Intractable pain ,Neurology (clinical) ,business ,tissues ,Left lower extremity - Abstract
Introduction: Spinal cord stimulation (SCS) is an efficient procedure for treatment of intractable pain. Methods: We present a patient who underwent SCS lead placement for severe left lower extremity pain. The patient had experienced good pain. He underwent thermographic imaging before, just after and ten days later of procedure. Results: Thermogram study revealed from blue color (hypothermic) pattern at before procedure to reddish or pink color (hyperthermic) pattern at ten days later. Discussion: SCS may be increase microcirculation and seems to have sympatholytic effects. Conclusion: We experienced that improvement of blood flow as result of SCS in CRPS.
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- 2010
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110. A low-noise, 900-MHz VCO in 0.6-μm CMOS
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Beomsup Kim and Chan-Hong Park
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Frequency synthesizer ,Voltage-controlled oscillator ,Materials science ,Offset (computer science) ,CMOS ,Noise measurement ,Oscillation ,business.industry ,Phase noise ,Electrical engineering ,dBc ,Electrical and Electronic Engineering ,business - Abstract
This paper describes a low-noise, 900-MHz, voltage-controlled oscillator (VCO) fabricated in a 0.6-/spl mu/m CMOS technology. The VCO consists of four-stage fully differential delay cells performing full switching. It utilizes dual-delay path techniques to achieve high oscillation frequency and obtain a wide tuning range. The VCO operates at 750 MHz to 1.2 GHz, and the tuning range is as large as 50%. The measured results of the phase noise are -101 dBc/Hz at 100-kHz offset and -117 dBc/Hz at 600-kHz offset from the carrier frequency. This value is comparable to that of LC-based integrated oscillators. The oscillator consumes 10 mA from a 3.0-V power supply. A prototype frequency synthesizer with the VCO is also implemented in the same technology, and the measured phase noise of the synthesizer is -113 dSc/Hz at 100-kHz offset.
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- 1999
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111. Design of Microstrip Patch Antenna Using Inset-Fed Layered for Metallic Object in u-Port
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Yong-Seok Choi, Myung-Dong Kim, Jong-Dae Park, Hyeon-Kyeong Seong, Byeong-Ho Park, and Chan-Hong Park
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Patch antenna ,Microstrip antenna ,Materials science ,Antenna height considerations ,Acoustics ,Port (circuit theory) ,Antenna (radio) ,Electrical impedance ,Computer Science::Information Theory ,Common emitter ,Ground plane - Abstract
In this paper, an industrial RFID layered microstrip patch antenna is designed using an inset feed method in order to improve recognition rates in a long distance as tags are attached to metal objects by improving a problem of feeding power in fabricating metal tags and reducing effects of metallic objects. The inset feed shows a distinctive characteristic that has no separation between emitters and feed lines differing from a structure with the conventional inductive coupling feed. This structure makes possible to produce a type that presents a low antenna height and enables impedance coupling for tag chips. Although it shows a difficulty in the impedance coupling due to increases in the parasite capacitance between a ground plane and an emitter in an antenna according to decreases in the height of a tag antenna, it may become a merit in designing the tag antenna because the antenna impedance can be determined as an inductive manner if a shorted structure is used for feeding power. Therefore, in this paper the microstrip patch antenna is designed as a modified type and applies the inset feed in order to reduce effects of metallic objects where the antenna is to be attached. Also, the antenna uses a multi-layer structure instead of using a single layer. That is, a metal plate is inserted to the contact between an emitter and a ground plane for preventing a decrease in its characteristics.
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- 2013
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112. Cerebral Thromboembolic Events During Anterior Cervical Spine Surgery: Retrospective Case Series Study With Diffusion-Weighted Magnetic Resonance Imaging Followup in the Immediate Postoperative Period.
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Seok-Won Chung, Min-Soo Kang, Sang-Ho Lee, Shin-Young Lee, Yong-Hwan Shin, and Chan-Hong Park
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DIFFUSION magnetic resonance imaging ,CEREBRAL embolism & thrombosis ,SPINAL surgery - Abstract
Objective: We evaluated the efficacy of diffusion-weighted magnetic resonance imaging (DW-MRI) in detecting perioperative cerebral thromboembolic events after anterior cervical discectomy and fusion (ACDF). Methods: This retrospective case series included 51 consecutive patients that underwent ACDF. To assess baseline presence of plaque or stenosis, all patients were assessed for risk factors of cerebrovascular events and underwent carotid ultrasound preoperatively and cerebral DW-MRI was performed in all patients postoperatively, with areas of high signal intensity interpreted as a cerebral thromboembolic event. Results: One male patient who underwent a C4/5 ACDF had a focal diffusion abnormality on DW-MRI concerning for cerebral thromboembolic events in the right posterior cerebral artery territory. He remained asymptomatic and did not display related neurological symptoms, such as visual deficits. Conclusion: Asymptomatic cerebral thromboembolic events can be detected by DW-MRI after ACDF. The incidence of such events remains very rare despite the direct manipulation and associated alteration of common carotid artery flow dynamics. [ABSTRACT FROM AUTHOR]
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- 2018
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113. Eidurographic Findings Following Percutaneous Epidural Adhesiolysis Failed to Correlate with Level of Pain Reduction in Patients with Lumbar Spinal Stenosis
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Chan Hong Park and Sang Ho Lee
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Adult ,Epidural Space ,medicine.medical_specialty ,Visual analogue scale ,Spinal stenosis ,medicine.medical_treatment ,Injections, Epidural ,Neurogenic claudication ,03 medical and health sciences ,Spinal Stenosis ,0302 clinical medicine ,030202 anesthesiology ,medicine ,Humans ,Minimally Invasive Surgical Procedures ,Pain Management ,Spinal canal ,Anesthetics, Local ,Aged ,Aged, 80 and over ,Lumbar Vertebrae ,business.industry ,Epidural steroid injection ,Lumbar spinal stenosis ,General Medicine ,Middle Aged ,medicine.disease ,Combined Modality Therapy ,Magnetic Resonance Imaging ,Low back pain ,Epidural space ,Surgery ,Treatment Outcome ,Anesthesiology and Pain Medicine ,medicine.anatomical_structure ,Anesthesia ,Neurology (clinical) ,medicine.symptom ,business ,Low Back Pain ,030217 neurology & neurosurgery - Abstract
Background. Spinal stenosis is characterized by narrowing of the spinal canal, with mechanical compression of spinal nerve roots. The latter may cause low back pain and/or leg pain, as well as neurogenic claudication. Epidural steroid injection is commonly used to treat patients with lumbar spinal stenosis (LSS), but percutaneous epidural adhesiolysis has been utilized when symptoms prove refractory. Our goal was to assess the relationship between improvement shown on epidurogram and subjective patient response to adhesiolysis. Methods. For this prospective study, 78 patients with degenerative LSS were enrolled. Each subject underwent magnetic resonance imaging of the lumbar spine, with all therapeutic procedures conducted in the operating room. Two weeks later, a second epidurography was performed. Second epidurography was conducted to assess any change in epidural filling defects. Outcome measures were obtained using the visual analogue scale (VAS) score at two weeks, one month, and three months post-treatment. Results. All of the 78 study participants (mean age = 60.9 years, range = 34–85 years) displayed epidural filling defects at baseline. After percutaneous adhesiolysis, epidurographic filling defects were absent in 73% of patients. In the presence or absence of filling defects, mean VAS scores were 5.2 and 4.5, respectively, at two weeks’ follow-up. No significant correlation between postprocedural VAS score and status of filling defects (yes or no) was evident during the three-month follow-up period. Conclusion. In patients with LSS, eidurographic findings following percutaneous epidural adhesiolysis failed to correlate with level of pain reduction achieved.
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- 2016
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114. Association between serum gonadotropin level and insulin resistance-related parameters in Korean women with polycystic ovary syndrome
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Sungwook Chun and Chan-Hong Park
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Luteinizing hormone ,endocrine system ,medicine.medical_specialty ,030209 endocrinology & metabolism ,03 medical and health sciences ,Follicle-stimulating hormone ,0302 clinical medicine ,Insulin resistance ,Waist–hip ratio ,Internal medicine ,Reproductive Endocrinology ,Medicine ,Polycystic ovary syndrome ,030219 obstetrics & reproductive medicine ,business.industry ,Follicle stimulating hormone ,Obstetrics and Gynecology ,medicine.disease ,Antral follicle ,Polycystic ovary ,Endocrinology ,Original Article ,business ,Body mass index ,Gonadotropins ,Hormone - Abstract
Objective To evaluate the relationship between serum gonadotropin level and parameters related to insulin resistance in Korean women with polycystic ovary syndrome (PCOS). Methods This retrospective study included 138 women aged 18 to 35 years who were newly diagnosed with PCOS according to the Rotterdam consensus. Participants were divided into three groups based on the serum luteinizing hormone to follicle-stimulating hormone (LH/FSH) ratio in the early follicular phase: group 1 (LH/FSH 2.0), and group 3 (LH/FSH ≥2.0). The correlations between the LH/FSH ratio and various metabolic parameters were evaluated using Pearson correlation coefficients. Results Patients with higher LH/FSH ratios showed higher total antral follicle counts and higher total ovarian volume. In the comparison of anthropometric and biochemical parameters among the three groups, the waist to hip ratio was the only parameter that differed significantly among the groups (P=0.003). Correlation analysis revealed no significant correlations between serum LH/FSH ratios and biochemical parameters related to insulin resistance. However, after adjustments for age and body mass index, a significant correlation between total cholesterol level and serum LH/FSH ratio was observed (r=0.221, P=0.018). Conclusion Most parameters related to insulin resistance, with the exception of total cholesterol level, are unrelated to the inappropriate pattern of serum gonadotropin secretion in Korean women with PCOS.
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- 2016
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115. Effect of relative injectate pressures on the efficacy of lumbar transforaminal epidural steroid injection in patients with lumbar foraminal stenosis
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Sang Ho Lee and Chan Hong Park
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Male ,medicine.medical_specialty ,medicine.medical_treatment ,Pain relief ,Injections, Epidural ,Lumbar ,Spinal Stenosis ,Adrenal Cortex Hormones ,medicine ,Pressure ,Humans ,In patient ,Radiculopathy ,Aged ,Pain Measurement ,Foraminal stenosis ,Aged, 80 and over ,Epidural steroid ,Epidural steroid injection ,business.industry ,Middle Aged ,medicine.disease ,Surgery ,Anesthesiology and Pain Medicine ,Treatment Outcome ,Pain reduction ,Radicular pain ,Anesthesia ,Female ,business - Abstract
Objective Transforaminal epidural steroid injections (TFESIs) are often used to treat lumbar foraminal stenosis. Injectate pressure (of contrast) was monitored during fluoroscopically guided TFESI to assess the effect on short-term pain reduction. Design A total of 40 patients underwent single-level lumbar TFESI for unilateral lumbar radicular pain ascribed to foraminal stenosis. Relative injectate pressure of contrast epidurography during TFESI was recorded and compared with pre- and postprocedural pain levels using the Roland 5-point pain scoring method. Results Pain relief achieved after TFESI revealed no statistically significant correlation with injectate pressure (mean 13.0 cm H2O). Mean pressures in patients with and without demonstrable pain reduction were 12.9 and 13.2 cm H2O, respectively. Limitations Secondary outcomes were not measured, and no mid- or long-term follow-up was conducted. Conclusion In this setting, relative injectate pressures had no significant effect on immediate outcomes of TFESI.
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- 2012
116. Effect of intravenous lidocaine on the neuropathic pain of failed back surgery syndrome
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Sug Hyun Jung, Chan Hong Park, and Chang Gyu Han
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neuropathic pain ,medicine.medical_specialty ,systemic lidociane ,Lidocaine ,business.industry ,Visual analogue scale ,medicine.medical_treatment ,Nerve injury ,Placebo ,Spinal cord ,Crossover study ,pain quality ,Surgery ,Anesthesiology and Pain Medicine ,medicine.anatomical_structure ,Anesthesia ,Neuropathic pain ,Medicine ,Original Article ,failed back surgery syndrome ,medicine.symptom ,business ,Saline ,medicine.drug - Abstract
Background: An intravenous infusion of lidocaine has been used on numerous occasions to produce analgesia in neuropathic pain. In the cases of failed back surgery syndrom, the pain generated as result of abnormal impulse from the dorsal root ganglion and spinal cord, for instance as a result of nerve injury may be particularly sensitive to lidocaine. The aim of the present study was to identify the effects of IV lidocaine on neuropathic pain items of FBSS. Methods: The study was a randomized, prospective, double-blinded, crossover study involving eighteen patients with failed back surgery syndrome. The treatments were: 0.9% normal saline, lidocaine 1 mg/kg in 500 ml normal saline, and lidocaine 5 mg/kg in 500 ml normal saline over 60 minutes. The patients underwent infusions on three different appointments, at least two weeks apart. Thus all patients received all 3 treatments. Pain measurement was taken by visual analogue scale (VAS), and neuropathic pain questionnaire. Results: Both lidocaine (1 mg/kg, 5 mg/kg) and placebo significantly reduced the intense, sharp, hot, dull, cold, sensitivity, itchy, unpleasant, deep and superficial of pain. The amount of change was not significantly different among either of the lidocaine and placebo, or among the lidocaine treatments themselves, for any of the pain responses, except sharp, dull, cold, unpleasant, and deep pain. And VAS was decreased during infusion in all 3 group and there were no difference among groups. Conclusions: This study shows that 1 mg/kg, or 5 mg/kg of IV lidocaine, and palcebo was effective in patients with neuropathic pain attributable to FBSS, but effect of licoaine did not differ from placebo saline. (Korean J Pain 2012; 25: 94-98)
- Published
- 2012
117. A Study on Design of Microstrip Patch Antenna for Mobile Communication Systems
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Jong-Dae Park, Myung-Dong Kim, Hyeon-Kyeong Seong, Sung-Won Jang, Chan-Hong Park, and Byeong-Ho Park
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Materials science ,Coaxial antenna ,business.industry ,Phased array ,Acoustics ,Bandwidth (signal processing) ,Astrophysics::Instrumentation and Methods for Astrophysics ,Particle swarm optimization ,Relative permittivity ,Microstrip patch antenna ,Microstrip antenna ,Mobile telephony ,business ,Computer Science::Information Theory - Abstract
In this paper, a novel particle swarm optimization method based on IE3D is used to design a mobile communication Microstrip Patch Antenna. The aim of the thesis is to Design and fabricate an inset fed rectangular Microstrip Antenna and paper the effect of antenna dimensions Length (L), Width (W) and substrate parameters relative Dielectric constant (e r ), substrate thickness on Radiation parameters of Band width. When the antenna was designed, a dual-band, dual-polarized antenna was used to secure the bandwidth and improve performance, and a coaxial probe feeding method so that the phased array of antenna is easy.
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- 2012
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118. Overcoming Overlapped Fields and Geolocation Errors in Point‐Dipole Magnetic Field Inversions
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R. M. René, Ki Young Kim, Chan Hong Park, and Ryan T. René
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Geolocation ,Dipole ,Point (geometry) ,Geodesy ,Geology ,Magnetic field ,Remote sensing - Published
- 2012
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119. A seismic experiment in the Ulleung Basin (Tsushima Basin), southwestern Japan Sea (East Sea of Korea)
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Chan Hong Park, Tae Woong Chung, V. Zhigulef, Hyeong Tae Jou, Jong Kuk Hong, Han-Joon Kim, and G. I. Anosov
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geography ,geography.geographical_feature_category ,Crust ,Structural basin ,Seismic wave ,Paleontology ,Tectonics ,Geophysics ,Mohorovičić discontinuity ,Oceanic crust ,General Earth and Planetary Sciences ,Sedimentary rock ,Oceanic basin ,Geology ,Seismology - Abstract
Understanding the crustal structure of the Ulleung basin (Tsushima basin) in the southwestern Japan sea (East sea of Korea) is important for reconstructing the opening tectonics of the Japan sea. A Korea and Russia collaborative seismic experiment was carried out in 1991 to investigate the crustal structure of this basin using ocean bottom seismometers (OBSs) and large capacity air guns. The results of the experiment reveal that the Ulleung basin is floored by distinctive upper and lower crustal layers with velocities typical of layers 2 and 3. The lower crust, however, is unusually thick (7–8 km) and the Moho lies flat at 15–16 km depths. Though similar to the Yamato basin in crustal thickness, the Ulleung basin has a much thicker sedimentary sequence and a slightly thinner lower crust in the center. Geophysical evidence, thus, shows that the crust under the Ulleung basin has velocity range and crustal layering falling closer to those of normal oceanic crust than the Yamato basin. The formation mechanism of the thicker than normal lower crust should be clarified to better understand the complex opening process in the southern Japan sea.
- Published
- 1994
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120. Dural sac cross-sectional area does not correlate with efficacy of percutaneous adhesiolysis in single level lumbar spinal stenosis
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Sang Ho Lee, Jin Young Jung, and Chan Hong Park
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Adult ,Male ,medicine.medical_specialty ,Percutaneous ,Spinal stenosis ,Injections, Epidural ,Neurogenic claudication ,Tissue Adhesions ,Lumbar ,Spinal Stenosis ,Adrenal Cortex Hormones ,Medicine ,Humans ,Spinal canal ,Anesthetics, Local ,Prospective cohort study ,Aged ,Aged, 80 and over ,Saline Solution, Hypertonic ,Lumbar Vertebrae ,business.industry ,Lumbar spinal stenosis ,Middle Aged ,medicine.disease ,Low back pain ,Magnetic Resonance Imaging ,Surgery ,Anesthesiology and Pain Medicine ,medicine.anatomical_structure ,Treatment Outcome ,Anesthesia ,Female ,Dura Mater ,medicine.symptom ,business ,Low Back Pain - Abstract
Background: Spinal stenosis is a narrowing of the spinal canal, which causes mechanical compression of spinal nerve roots. The compression of these nerve roots can cause low back pain and/or leg pain, as well as neurogenic claudication. Lumbar epidural steroid injections have commonly been used in patients with lumbar spinal stenosis (LSS). In cases that are refractory to epidural steroid injections, percutaneous epidural adhesiolysis has been used. Objective: The aim of our study is to determine the relationship between the severity of spinal stenosis and the participants’ response to adhesiolysis, and to evaluate the mid-term effectiveness of adhesiolysis. Study Design: A prospective observational study. Methods: Sixty-six patients with degenerative LSS were enrolled in this prospective study. All participants underwent lumbar spine magnetic resonance imaging (MRI). The cross-sectional area of the dural sac was measured on the transverse angled sections through the central part of the disc on conventional MR images. All percutaneous adhesiolyses were performed in the operating room. One hour following the procedure, 6 mL of 8% sodium chloride solution was infused during 30 minutes in the recovery room while the patient underwent monitoring. Outcome measures were obtained using the 5-point patient satisfaction scale at 2 weeks and 6 months post-treatment. To evaluate outcome predictors, we divided the participants into 2 groups according to their response to treatment. Limitations: Secondary outcomes were not measured and the study did not include a long-term follow-up period. Results: Improvement (including reports of slightly improved, much improved, and no pain) was observed in 49 participants (74.2%) at 2 weeks and 45 participants (66.7%) at 6 months after the procedure. The dural sac cross-sectional area (DSCSA) did not differ between participants who reported improvement and those who did not. There was no statistically significant correlation between pain relief and DSCSA, age, or participant sex. Conclusion: Percutaneous adhesiolysis was shown to be effective for the treatment of LSS, with mid-term result, without affecting DSCSA. Key words: Low back pain, lumbar spinal stenosis, failed back surgery syndrome, dural sac, interventional techniques, epidural injection, percutaneous adhesiolysis.
- Published
- 2011
121. Lumbar retrodiscal versus post-ganglionic transforaminal epidural steroid injection for the treatment of lumbar intervertebral disc herniations
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Chan Hong, Park, Sang Ho, Lee, and Hahck Soo, Park
- Subjects
Adult ,Male ,Lumbar Vertebrae ,Double-Blind Method ,Adrenal Cortex Hormones ,Case-Control Studies ,Humans ,Injections, Epidural ,Female ,Middle Aged ,Intervertebral Disc Displacement ,Pain Measurement - Abstract
Lumbar transforaminal epidural steroid injections (TFESIs) are procedures often utilized in the treatment of radicular pain. TFESIs with a preganglionic approach have been reported to be more effective than TFESIs performed using a classic approach. However, it is unknown whether TFESIs using a retrodiscal approach are as effective as other approaches.To investigate the effect of an epidural steroid injection (ESI) on radicular pain, we conducted a randomized, controlled trial comparing a retrodiscal approach with a classic approach to treat lumbar disc herniation.A case control study.Forty patients were randomized to receive lumbar TFESIs with either a retrodiscal approach (n=20) or with a classic approach (n=20). Measurements were taken before as well as 4 and 8 weeks after treatment using a visual analog scale (VAS) score, Patient Satisfaction Index (PSI) and the Roland 5-point pain score.In the retrodiscal group, there was a statistically significant improvement in the VAS score after injection compared to baseline. In the classic group, there was a statistically significant improvement in the VAS score after injection compared to baseline. There was no statistically significant difference in the VAS score, PSI, or the Roland 5-point pain score between those treated with a retrodiscal approache and those treated with a classic approach.Secondary outcomes were not measured and the study did not include a mid- or long-term follow-up period.In this study, TFESIs performed using a retrodiscal or classic approach had similar effects on radicular pain. The classic and the retrodiscal transforaminal steroid injection resulted in equivalent pain relief.
- Published
- 2011
122. Dermatomal skin rash after lumbar epidural steroid injection
- Author
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Sang Ho Lee, Yong Hwan Shin, and Chan Hong Park
- Subjects
medicine.medical_specialty ,medicine.medical_treatment ,Injections, Epidural ,Lumbar vertebrae ,Lumbar epidural steroid injection ,Lumbar ,Clinical report ,Dermatomal ,medicine ,Humans ,Lumbar Vertebrae ,business.industry ,Epidural steroid injection ,Middle Aged ,Rash ,Surgery ,Anesthesiology and Pain Medicine ,medicine.anatomical_structure ,Anesthesia ,Female ,Steroids ,Neurology (clinical) ,Drug Eruptions ,medicine.symptom ,business ,Complication - Abstract
Objectives the objective of this case is to report an occurrence of a skin rash in a dermatomal distribution subsequent to a lumbar transforaminal epidural steroid injection. Methods in this clinical report, a 54-year old woman performed a left L5 transforaminal epidural steroid injection to manage left thigh and foot pain and tingling. She developed a rash in left L5 dermatomal distribution following injection. Results and discussion this is the first described case of a focal dermatomal rash occurring following lumbar transforaminal epidural steroid injection and we wish to remind pain practitioner’s of the possibility of anaphylactic events.
- Published
- 2011
123. Prognostic usefulness of high sensitivity C-reactive protein for transforaminal epidural steroid injection in patients with radicular pain
- Author
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Sang Ho Lee and Chan Hong Park
- Subjects
Adult ,Male ,Visual analogue scale ,Spinal stenosis ,medicine.medical_treatment ,Injections, Epidural ,Pain ,Neurogenic claudication ,Lumbar ,Spinal Stenosis ,Medicine ,Humans ,cardiovascular diseases ,Radiculopathy ,Aged ,business.industry ,Epidural steroid injection ,Lumbar spinal stenosis ,General Medicine ,Middle Aged ,medicine.disease ,Prognosis ,Low back pain ,Anesthesiology and Pain Medicine ,C-Reactive Protein ,Radicular pain ,Anesthesia ,Steroids ,Neurology (clinical) ,medicine.symptom ,business ,Biomarkers - Abstract
Objective. There are several types of lumbar stenosis, such as central, lateral recess, foraminal. The symptoms of lumbar stenosis are neurogenic claudication, numbness, tingling, etc. The treatment modality is medication, physical therapy, intervention, and surgery. The epidural steroid injection has been used for treatment of low back pain/radiculopathy. However, we could not predict what percent had pain relief after epidural steroid injection. The purpose of this study was to evaluate the usefulness of high sensitivity C-reactive protein (hsCRP) as a marker for predicting the efficacy of lumbar transforaminal epidural steroid injection. Design. A total of 55 patients with lumbar stenosis underwent lumbar transforaminal epidural steroid injection under fluoroscopic guidance. Prior to injection, all patients were examined and their visual analog scale (VAS) score and hsCRP score were recorded. They returned 4 weeks following their initial injection and repeat hsCRP, and VAS sores were obtained. Results. The average pretreatment hsCRP and VAS score for all 55 patients were 3.2 ± 4.3 mg/L and 8.1 ± 1.1, respectively. Forty-two of 55 patients had 1.6 mg/L of hsCRP. After procedure, the VAS decreased from 8.0 ± 1.1 to 2.5 ± 1.1. In contrast, the averages of hsCRP and VAS scores of 13 patients were 9.4 ± 3.7 mg/L and 8.2 ± 0.9, respectively, at baseline, which decreased to 1.2 ± 0.9 mg/L and 2.5 ± 0.8 at 4 weeks later. At posttreatment, the VAS score difference between the two groups was not statistically significant. There was no correlation between hsCRP and VAS score ( P = 0.426). Conclusion. The results suggest that there was no correlation between pretreat hsCRP and posttreat VAS. Therefore, hsCRP may not be useful as predictor of response to TFESI in patients with spinal stenosis.
- Published
- 2011
124. A Study on Receiving Performance Improvement of LTE Communication Network Using Multi-hop Relay Techniques
- Author
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Yong-Seok Choi, Chan-Hong Park, Hyeon-Kyeong Seong, and Young-Hwan Han
- Subjects
Terminal (telecommunication) ,business.industry ,Computer science ,Telecommunications network ,Multi hop relay ,law.invention ,Set (abstract data type) ,Installation ,Relay ,law ,Mobile telephony ,Performance improvement ,business ,Computer network - Abstract
This paper made research to boost reception performance in link-down transmission method of LTE system, which is the next-generation mobile communication technology standard underway in 3GPP. To this end, it proposed installing relay (RS) in between station(BS) and terminal(MS), set the distance between BS and RS at 500m and 1,000m, each, and chose OFDMA and SC-FDMA as transmission method of RS. The paper found SC-FDMA to be better choice in RS when it is closer to BS and OFDMA to be a better choice in RS when the distance between BS and RS is farther. The system’s reception performance improved when the most appropriate transmission method fitting the circumstances was used in the middle between BS and MS.
- Published
- 2011
- Full Text
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125. Single-chip RF CMOS UMTS/EGSM transceiver with integrated receive diversity and GPS
- Author
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Hongyan Yan, E. Lei, H. Lee, Kamal Sahota, R. Jonnalagedda, T. Pan, B. Ahrari, Sang-Oh Lee, Beomsup Kim, Chan-Hong Park, S. Sridhara, Charles J. Persico, Kevin Hsi Huai Wang, Wei Zhuo, C. Conroy, Jian Yang, Jin-Su Ko, T. Nguyen, R. Brockenbrough, Wenjun Su, Hong Sun Kim, J. Chen, Marco Cassia, Aristotele Hadjichristos, Jonghae Kim, and Conor Donovan
- Subjects
Spread spectrum ,Engineering ,Multi-mode optical fiber ,CMOS ,business.industry ,GSM ,Global Positioning System ,Electronic engineering ,Enhanced Data Rates for GSM Evolution ,Transceiver ,business ,UMTS frequency bands - Abstract
The large commercial success of multiband multimode 3rd-generation cellular products has driven single-chip integration, SAW-filter reduction and low power consumption. State-of-the-art solutions require quad-band EGSM combined with multiband WCDMA/HSPA receiver diversity and integrated GPS. Compact form factors make single-chip SAW-less solutions highly desirable. A Quad-Band GSM/EDGE-only transceiver was published in [1], and Triple-Band WCDMA-only transceiver solutions were published in [2–4]. This work describes the first multiband WCDMA/HSPA/EGPRS single-chip transceiver with GPS and receiver diversity. This device supports UMTS Bands 1,2,3,4,5,6,8,9,10 and GSM/EDGE 800, 900, 1800, 1900MHz Bands. It is implemented in cost-effective 0.18µm RF CMOS technology and uses a reduced number of TX and RX SAW filters.
- Published
- 2009
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126. Description of Croceitalea gen. nov. in the family Flavobacteriaceae with two species, Croceitalea eckloniae sp. nov. and Croceitalea dokdonensis sp. nov., isolated from the rhizosphere of the marine alga Ecklonia kurome
- Author
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Sang-Jin Kim, Jung-Hyun Lee, Hee-Soon Lee, Sung-Hyun Yang, Chan Hong Park, Kae Kyoung Kwon, and Seung Seob Bae
- Subjects
DNA, Bacterial ,Ecklonia kurome ,Sequence analysis ,Molecular Sequence Data ,Phaeophyta ,Microbiology ,DNA, Ribosomal ,Species Specificity ,RNA, Ribosomal, 16S ,Botany ,Seawater ,Ecology, Evolution, Behavior and Systematics ,Phylogeny ,Rhizosphere ,Base Composition ,Korea ,biology ,Fatty Acids ,General Medicine ,Sequence Analysis, DNA ,Ribosomal RNA ,16S ribosomal RNA ,biology.organism_classification ,Flavobacteriaceae ,Bacterial Typing Techniques ,Type species ,Phenotype ,Taxonomy (biology) - Abstract
Two novel bacterial strains, designated DOKDO 025(T) and DOKDO 023(T), were isolated on Dokdo Island, Korea, from the rhizosphere of the brown alga Ecklonia kurome. The strains were subjected to a polyphasic taxonomy study and were found to be Gram-negative, aerobic, rod-shaped, non-motile and orange-coloured. The isolates shared 96.3 % 16S rRNA gene sequence similarity. They showed 93.8-95.6 % 16S rRNA gene sequence similarity with respect to members of the genus Muricauda in the family Flavobacteriaceae, but formed a distinct phyletic line. Moreover, the cellular appendages reported for all Muricauda species were absent from strains DOKDO 025(T) and DOKDO 023(T). The predominant cellular fatty acids of strain DOKDO 025(T) were iso-C(15 : 0), iso-C(15 : 1) and one with an equivalent chain-length of 13.565 and those of strain DOKDO 023(T) were iso-C(15 : 0), iso-C(15 : 1) and iso-C(17 : 0) 3-OH. The DNA G+C content of strains DOKDO 025(T) and DOKDO 023(T) were 59.5 and 66.5 mol%, respectively, higher than any values found in recognized members of the family Flavobacteriaceae. The major respiratory quinone was MK-6. On the basis of evidence from the polyphasic study, strains DOKDO 025(T) and DOKDO 023(T) represent two novel species in a new genus, Croceitalea gen. nov., for which the names Croceitalea eckloniae sp. nov. (the type species) and Croceitalea dokdonensis sp. nov. are proposed. The type strain of Croceitalea eckloniae sp. nov. is DOKDO 025(T) (=KCCM 42309(T) =JCM 13827(T)) and that of Croceitalea dokdonensis sp. nov. is DOKDO 023(T) (=KCCM 42308(T) =JCM 13826(T)).
- Published
- 2008
127. Hybrid Resource Allocation Algorithm for Inter-cell Interference Avoidance in LTE-Advanced System
- Author
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Chan-Hong Park and Seong Hyeon Kyeong
- Subjects
LTE Advanced ,Interference (communication) ,business.industry ,Computer science ,Resource allocation ,Resource allocation algorithm ,business ,Computer network - Published
- 2015
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128. EDGE-ADAPTIVE GAPPED GRADIENT-NULLING FILTERS AND INVERSION OF MAGNETIC FIELDS IN A LAKE SURVEY OF POSSIBLE DREDGING HAZARDS AND UXO
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Chan Hong Park, Ki Young Kim, and R. M. René
- Subjects
Unexploded ordnance ,Dipole ,Mining engineering ,Perpendicular ,Stereographic projection ,Inversion (meteorology) ,Geodesy ,Magnetic dipole ,Geology ,Regular grid ,Magnetic field - Abstract
A method of modifying a zero-dc symmetric filter to obtain an edge-adaptive gapped gradientnulling (EAGGN) filter is developed and tested on sparse magnetic field data. These data were obtained in a magnetic field survey on Chongcho Lake in the Republic of Korea to determine possible dredging hazards or impediments including possible unexploded ordnance (UXO). The data are interpolated to a regular grid but only grid points proximate to the observed field stations are flagged for use in inversion. The least-squares inversion simultaneously estimates a modeled magnetic dipole, dc-bias and, optionally, a constant-gradient background (regional) field. The EAGGN filter is applied as a preinversion filter here, but is also useful as an intra-inversion filter for other applications including UXO surveys. Bull’s eye plots present a stereographic projection of a dipole’s orientation onto a plane perpendicular to the earth’s field. These help visualize the deviation of a magnetic dipole’s orientation from the direction of the earth’s field. Deviations of less than 60 deg are consistent with UXO that have been shock demagnetized by firing or impact.
- Published
- 2006
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129. Edge‐Adaptive Gapped Gradient‐Nulling Filters and Inversion of Magnetic Fields in a Lake Survey of Possible Dredging Hazards and UXO
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R. M. René, Chan Hong Park, and Ki Young Kim
- Published
- 2006
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130. Epidurographic Findings Following Percutaneous Epidural Adhesiolysis Failed to Correlate with Level of Pain Reduction in Patients with Lumbar Spinal Stenosis.
- Author
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Chan Hong Park and Sang Ho Lee
- Subjects
- *
TISSUE adhesions , *SPINAL stenosis treatment , *SPINE radiography , *STATISTICAL correlation , *LONGITUDINAL method , *LUMBAR vertebrae , *HEALTH outcome assessment , *VISUAL analog scale , *TREATMENT effectiveness , *THERAPEUTICS - Abstract
Background. Spinal stenosis is characterized by narrowing of the spinal canal, with mechanical compression of spinal nerve roots. The latter may cause low back pain and/or leg pain, as well as neurogenic claudication. Epidural steroid injection is commonly used to treat patients with lumbar spinal stenosis (LSS), but percutaneous epidural adhesiolysis has been utilized when symptoms prove refractory. Our goal was to assess the relationship between improvement shown on epidurogram and subjective patient response to adhesiolysis. Methods. For this prospective study, 78 patients with degenerative LSS were enrolled. Each subject underwent magnetic resonance imaging of the lumbar spine, with all therapeutic procedures conducted in the operating room. Two weeks later, a second epidurography was performed. Second epidurography was conducted to assess any change in epidural filling defects. Outcome measures were obtained using the visual analogue scale (VAS) score at two weeks, one month, and three months post-treatment. Results. All of the 78 study participants (mean age = 60.9 years, range = 34-85 years) displayed epidural filling defects at baseline. After percutaneous adhesiolysis, epidurographic filling defects were absent in 73% of patients. In the presence or absence of filling defects, mean VAS scores were 5.2 and 4.5, respectively, at two weeks' follow-up. No significant correlation between postprocedural VAS score and status of filling defects (yes or no) was evident during the three-month follow-up period. Conclusion. In patients with LSS, epidurographic findings following percutaneous epidural adhesiolysis failed to correlate with level of pain reduction achieved. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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131. Design of a 3.0 V CMOS continuous time low-pass filter with on-chip tuning circuits for CDMA cellular phone application
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Chan-Hong Park and Beomsup Kim
- Subjects
Phase-locked loop ,Engineering ,CMOS ,business.industry ,Filter (video) ,Low-pass filter ,Electronic engineering ,Prototype filter ,business ,Chip ,m-derived filter ,Electronic circuit - Abstract
This paper describes a 6/sup th/-order continuous-time elliptic low-pass filter fabricated in a 0.8 /spl mu/m 2-poly, 2-metal CMOS process. The magnitude and phase characteristics meet the specification of the analog processor used in CDMA cellular phone system. The direct sample method is used in on-chip tuning circuit and it requires less area and power dissipation than conventional method using PLL. The tuning circuit stabilizes the cut-off frequency of the filter to 630 kHz with a stable external clock. Experimental results show that the filter exhibits 0.5 dB passband ripple and 42 dB stop band attenuation. The whole chip dissipates about 12 mW from a single 3.0 V supply.
- Published
- 2005
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132. Intra-Inversion Filtering For Least-Squares Inversion Of Magnetic Dipole Fields In The Presence Of Residual Non-Dc Background Magnetic Fields And Overlapping Dipole Fields
- Author
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Ki Young Kim, R. M. René, and Chan Hong Park
- Subjects
Physics ,Dipole ,Nuclear magnetic resonance ,Inversion (meteorology) ,Filter (signal processing) ,Electric dipole transition ,Residual ,Magnetic dipole ,Magnetic field ,DC bias ,Computational physics - Abstract
Least-squares or similar magnetic field inversion is commonly used to characterize and distinguish unexploded ordnance (UXO) from other magnetic sources. The results may be inaccurate if fields of the target dipole sources are superimposed upon complex “regional” fields of deeper or more laterally extensive magnetic sources or if the tails of fields of nearby dipoles overlap significantly. Inversion commonly derives seven parameters for each dipole: three components of dipole moment, three coordinates to define the dipole’s position and the estimated DC bias. An inversion-derived estimate of the background field can be obtained by subtraction of the modeled dipole’s field from the input field. If that estimate of the background field is not approximated by a constant field plus random noise, then intra-inversion filtering (IIF) may provide a better estimate of magnetic dipole parameters. In the IIF method, a low-cut, high-cut, or band-pass filter is applied to the input field and the same, or similar, filter is applied to the components of the modeled fields used to match the observed field through inversion. The IIF method may be computationally efficient in the case of gridded data. The IIF filter is applied once to the fields of unit-strength dipoles at each possible depth in the search window for the target dipole. That field is then shifted laterally to obtain the field for all possible locations of the dipole beneath the nodes of the grid of field points. Low-cut (high-pass) IIF is demonstrated for synthetic fields of dipoles and non-dc bias in a regular orthogonal grid. The results are shown to be significantly better than those that are obtained by the simple least-squares inversion without filtering.
- Published
- 2004
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133. Intra‐Inversion Filtering for Least‐Squares Inversion of Magnetic Dipole Fields in the Presence of Residual Non‐DC Background Magnetic Fields and Overlapping Dipole Fields
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R. M. René, Chan Hong Park, and Ki Young Kim
- Published
- 2004
- Full Text
- View/download PDF
134. Enhanced Free-air Gravity Anomalies by Satellite Radar Altimetry
- Author
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Ralph R. B. von Frese, D. R. Roman, Chan Hong Park, and Jeong Woo Kim
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Geodesy ,Gravity anomaly ,Physics::Geophysics ,law.invention ,Wavelength ,Gravitational field ,Radar altimeter ,law ,Geoid ,Wavenumber ,Satellite ,Altimeter ,Physics::Atmospheric and Oceanic Physics ,Geology - Abstract
Ocean satellite altimetry-implied free-air gravity anomalies have had the shortest wavelengths removed during the processing to generate the optimal solution between multiple radar altimeter missions. ERS-1 168-day mission altimetry was residualized to a reference geoid surface generated by integrating Anderson and Knudsen’s free-air gravity anomalies for the Barents Sea. The altimetry tracks were reduced and filtered to extract the shortest wavelengths (between 4 and 111 km) from both ascending and descending tracks, respectively. These data were recombined using existing quadrant-swapping techniques in the wavenumber domain to generate a correlated, high frequency gravity field related to the local geologic sources. This added-value surface adjusted the reference free-air gravity anomalies to better reflect features in the gravity field at a wavelength related to the distance between altimetry ground tracks.
- Published
- 2003
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135. Quality-of-Life Evaluation of Patients Undergoing Lumbar Discectomy Using Short Form 36
- Author
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Chan Hong Park, Chan Park, Sang Ho Lee, and Sang Lee
- Subjects
Discectomy ,medicine.medical_specialty ,business.industry ,Pain medicine ,medicine.medical_treatment ,Letter to Editor ,Low back pain ,Mental health ,Anesthesiology and Pain Medicine ,Quality of life ,Anesthesiology ,Spinal fusion ,Quality of Life ,Physical therapy ,Medicine ,medicine.symptom ,business ,Low Back Pain ,Depression (differential diagnoses) - Abstract
Dear Editor, I have recently reviewed the interesting article by Farzanegan et al. (1), published in the 2011 issue of the Anesthesiology and Pain Medicine: “Quality of life (QOL) evaluation of patients undergoing lumbar discectomy using Short Form 36”. Lumbar discectomy improved both the physical and mental health subscales in patients’ QOL with chronic disc herniation. The mean improvement in physical health scores was significantly higher in the female patients, than in the male subjects. However, there are no statistically significant differences in the improvement in mental health scores between the two sexes, or their education levels and body mass index’ (BMI). Lumbar radiculopathy is a disease, and lumbar discectomy is the most common surgical procedure for patients who are experiencing back and leg pain as a result of herniated discs. It is well-known that surgical procedures such as; percutaneous endoscopic discectomy, lumbar microdiscectomy, or spinal fusion, improve the patients’ QOL after 6 months. Also QOL improves more quickly in surgically treated patients, then in those treated conservatively. The results of this article are consistent with previous studies. Depression plays a role in pain; it is a major contributor to how pain is processed and coped with, affecting QOL and disability after back surgery. Patients with more depressive symptoms preoperatively, were less likely to achieve clinically significant improvements in disability and QOL following lumbar discectomy (2). Hence, patients with depressive symptoms may benefit from preoperative psychological treatment, with the aim of improving their outcomes. Patients with psychological comorbidities often experience long-term disability from low-back pain. In the present study, the Short Form 36 (SF-36) questionnaire was used to assess QOL after lumbar surgery. The SF-36 consists of eight sections, which are; vitality, physical functioning, bodily pain, general health perceptions, physical role functioning, emotional role functioning, social functioning, and mental health. Despite the fact that the SF-36 has a number of advantages for the evaluation of QOL, there is still a need for greater precision in measuring QOL. In addition, this article lacks an interpretation of why educational levels and BMI do not affect the SF-36. In chronic low back pain patients, pain severity is more strongly related to being overweight and psychological factors than to pathophysiological changes (3). Although, this study has a few demerits, Farzanegan et al. have provided evidence that lumbar discectomy is a safe and effective technique to improve both the physical and mental health subscales of the QOL in patients with chronic disc herniation.
- Published
- 2012
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136. Commentary on: Quality of Life Evaluation of Patients Undergoing Lumbar Discectomy Using Short Form 36
- Author
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Chan Hong Park and Sang Ho Lee
- Subjects
Anesthesiology and Pain Medicine - Published
- 2012
- Full Text
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137. A low-noise 900 MHz VCO in 0.6 μm CMOS
- Author
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Beomsup Kim and Chan-Hong Park
- Subjects
Frequency synthesizer ,Physics ,Voltage-controlled oscillator ,CMOS ,business.industry ,Phase noise ,Electrical engineering ,Volt ,dBc ,Ring oscillator ,Center frequency ,business - Abstract
This paper presents a low noise 900 MHz voltage controlled oscillator (VCO) implemented in 0.6 /spl mu/m CMOS technology. The VCO based on a 4-stage ring oscillator adopted a new differential delay cell to reduce the phase noise. The measured phase noise is -101 dBc/Hz at 100 kHz offset from the center frequency and comparable to that of LC based integrated oscillators. The measured value is smaller than any other previously reported ones in the ring oscillator VCO's. A prototype frequency synthesizer with this VCO shows phase noise of -117 dBc/Hz at 100 kHz offset. The VCO operates from 750 MHz to 1.2 GHz with a single 3 volt power supply.
- Published
- 2002
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138. Low noise clock synthesizer design using optimal bandwidth
- Author
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Kyoohyun Lim, Chan-Hong Park, and Beomsup Kim
- Subjects
Phase-locked loop ,Direct digital synthesizer ,Computer science ,Bandwidth (signal processing) ,Electronic engineering ,Low noise ,Jitter - Abstract
This paper presents a salient method to design a low noise clock synthesizer for high-speed data processing applications. The proposed design method optimizes the loop bandwidth by using a discrete-time analysis of a PLL and minimizes the clock synthesizer output jitter. Computer simulation is performed and simulation results strongly support the theoretical analysis. A 900 MHz clock synthesizer is experimentally designed and shows the minimum jitter at the optimum bandwidth obtained from the analysis.
- Published
- 2002
- Full Text
- View/download PDF
139. A fully integrated CMOS RF front-end with on-chip VCO for WCDMA applications
- Author
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Chan-Hong Park, Beomsup Kim, Jae Joon Kim, Kyoohyun Lim, and Hyung Ki Ahn
- Subjects
Engineering ,RF front end ,Broadband networks ,business.industry ,Hardware_PERFORMANCEANDRELIABILITY ,Noise figure ,Voltage-controlled oscillator ,CMOS ,Phase noise ,Hardware_INTEGRATEDCIRCUITS ,CDMA2000 ,Electronic engineering ,business ,Intermodulation - Abstract
Increasing demand on the broadband data transmission via mobile phones drives standards for the third generation cellular phones. Both wide-band CDMA (WCDMA) and CDMA2000 compliant cellular phones make possible full-bandwidth Internet access. A high level of integration is necessary because of low power and low cost requirements, making CMOS implementation attractive. In the WDMA RF receiver, sensitivity, single-tone desensitization, and intermodulation rejection are the key performance indicators and should be minimized by controlling the parameters such as noise figure (NF), input-referred 3/sup rd/-order intercept (IIP3), gain distributions, and voltage-controlled oscillator (VCO) phase noise. Because of the high data rate supported by the WCDMA standard, more stringent control over the parameters is required. An on-chip VCO is helpful, because it eliminates I/O buffers and reduces substrate noise injection and power consumption.
- Published
- 2002
- Full Text
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140. A 1.8-GHz self-calibrated phase-locked loop with precise I/Q matching
- Author
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Ook Kim, Chan-Hong Park, and Beomsup Kim
- Subjects
Physics ,Frequency synthesizer ,Engineering ,Offset (computer science) ,Signal generator ,business.industry ,Electrical engineering ,Phase (waves) ,dBc ,Ring oscillator ,Hardware_PERFORMANCEANDRELIABILITY ,Phase-locked loop ,Loop (topology) ,Voltage-controlled oscillator ,CMOS ,PLL multibit ,Phase noise ,Hardware_INTEGRATEDCIRCUITS ,Electronic engineering ,Calibration ,Electrical and Electronic Engineering ,business ,Phase frequency detector ,Electronic circuit ,Hardware_LOGICDESIGN - Abstract
This paper describes a 1.8-GHz self-calibrated phase-locked loop (PLL) implemented in 0.35-/spl mu/m CMOS technology. The PLL operates as an edge-combining type fractional-N frequency synthesizer using multiphase clock signals from a ring-type voltage-controlled oscillator (VCO). A self-calibration circuit in the PLL continuously adjusts delay mismatches among delay cells in the ring oscillator, eliminating the fractional spur commonly found in an edge-combing fractional divider due to the delay mismatches. With the calibration loop, the fractional spurs caused by the delay mismatches are reduced to -55 dBc, and the corresponding maximum phase offsets between the multiphase signals is less than 0.20. The frequency synthesizer PLL operates from 1.7 to 1.9 GHz and the closed-loop phase noise is -105 dBc/Hz at 100-kHz offset from the carrier. The overall circuit consumes 20 mA from a 3.0-V power supply.
- Published
- 2002
- Full Text
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141. Location of Magnetic Dipoles in Chongcho Lake, Republic of Korea: An Application of the SOAPFI (Shape‐of‐Anomaly Potential Field Inversion) Program
- Author
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Chan Hong Park, R. M. René, and Ki Young Kim
- Published
- 2002
- Full Text
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142. Location Of Magnetic Dipoles In Chongcho Lake, Republic Of Korea: An Application Of The Soapfi (Shape-Of-Anomaly Potential Field Inversion) Program
- Author
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R. M. René, Chan Hong Park, and Ki Young Kim
- Subjects
Hydrology ,Dipole ,Curvilinear coordinates ,Geography ,The Intersect ,Potential field ,Inversion (meteorology) ,Filter (signal processing) ,Geophysics ,Magnetic dipole ,Magnetic field - Abstract
The SOAPFI (shape-of-anomaly potential field inversion) program has been previously applied to the inversion of gravity and magnetic data. These earlier applications add rectangular parallelepipeds to a growing model's periphery according to a criterion that minimizes the difference between the shapes of the modeled and observed fields using an L1- or L2-norm. That method is generalized here to the inversion of magnetic fields using one or more magnetic dipoles. In the presence of measurement or geologic noise, both the growing-model and magnetic dipole inversions are improved by the application of spatial filters to the observed and modeled fields. An improved “profile-adaptive” filtering of modeled fields matches the filter applied to the observed field in curvilinear profiles that may intersect and overlap. Approximately 90 km of magnetic-field profiles was recorded in the 1-km2 Chongcho Lake in Sokcho, Kangwon-do, Korea. Magnetic dipoles, including perhaps unexploded ordinance, were located in this lake. Automatic determination of dipole strengths and locations used total magnetic field anomalies. For each data window, one or more dipoles were modeled. To attenuate local anomalies due to broader and deeper sources than the targeted dipoles, spatial high-pass filtering was applied to observed data in profiles.
- Published
- 2002
- Full Text
- View/download PDF
143. The perfect alignment: Korea Hydro & Nuclear Power has employed a high precision photogrammetry technique to successfully ensure the correct alignment of nuclear fuel rod assemblies within a nuclear reactor vessel following a scheduled refueling outage
- Author
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Edmundson, Kenneth, Ganci, Giuseppe, and Chan-Hong, Park
- Subjects
Nuclear energy -- Methods ,Nuclear reactors -- Methods ,Nuclear power plants -- Methods ,Business ,Engineering and manufacturing industries ,Business, international ,Petroleum, energy and mining industries - Abstract
Measuring nuclear fuel rod assemblies is a difficult task because the environment is hazardous. The assemblies lie 12 m underwater and are radioactive. Faced with this, Korea Hydro & Nuclear [...]
- Published
- 2007
144. Erratum to: Possible origin of coastal sands and their long-term distribution along the high slope-gradient, wave-dominated eastern coast, Korea
- Author
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Jeseon Yoo, Jun-Yong Park, Ho Kyung Ha, Eui Young Jeong, Hee Jun Lee, Chang Woong Shin, SangHoon Lee, and Chan-Hong Park
- Subjects
Oceanography ,Benthic zone ,Terrigenous sediment ,Flash flood ,Slope gradient ,General Earth and Planetary Sciences ,Storm ,STREAMS ,Radial distribution ,Geomorphology ,Sediment transport ,Geology ,General Environmental Science - Abstract
This study aims to investigate possible source and long-term distributional patterns of coastal sands in the high slope-gradient, wave-dominated coast with no large rivers, eastern Korea. Chirp (2–7 kHz) seismic profiles show that the coastal sand deposits, the uppermost transparent layer, are up to 7.1 m thick off small, mountainous stream mouths, and thins laterally, showing a radial distribution from the stream mouths with a slightly SE-skewed elongated (i.e., alongshore) geometry. These features suggest that the terrigenous coarse sediments emptied by the streams during the summer flash flooding season have been a major source to the adjacent coastal sands. Hydrodynamic measurements with benthic tripod systems indicate that alongshore currents occurring during episodic storms play a significant role in the displacement of the coastal sands toward the southeast, resulting in the slightly SE-skewed elongated (i.e., alongshore) distributional geometry of the sands.
- Published
- 2013
- Full Text
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145. A digital audio signal processor for cellular phone application
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Chan-Hong Park, Beomsup Kim, and Jeongsik Yang
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Digital signal processor ,Audio signal ,Computer science ,business.industry ,Clock rate ,Filter (signal processing) ,Audio signal flow ,computer.software_genre ,Embedded system ,Mobile telephony ,Audio signal processing ,business ,Standby power ,computer ,Computer hardware ,Digital signal processing ,Digital audio - Abstract
A salient digital audio signal processor for a mobile communication receiver is described. With this IC, the complete audio signal processing system of an AMPS or a TACS cellular phone is easily implemented. The processor can be also applied to cellular radio, high performance cordless telephone, etc. In the paper, as an example of application, the implementation of the AMPS audio signal processing system is presented. To save power consumption, some special consideration of low power architectures has been made. The DSP core uses 4 stage pipelining without a routine memory access stage to reduce the power consumption and execution speed. The parallel calculations of data in the DSP and separated filter blocks also contribute to reduce the clock frequency and to save power. It also provides a power-down mode that turns off the IC except the internal bus interface in the standby mode. It uses a 3.3 V power supply, a 10 MHz 4-phase clock. The data sampling rate is 10 K-samples per second.
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- 1995
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146. Response to the Letter by Dr. Collighan
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Chan Hong Park
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medicine.medical_specialty ,Letter to the editor ,business.industry ,Significant difference ,Pain relief ,General Medicine ,Pearson product-moment correlation coefficient ,symbols.namesake ,Anesthesiology and Pain Medicine ,symbols ,Physical therapy ,Medicine ,Neurology (clinical) ,business - Abstract
Dear Editor, We appreciate the letter to the editor by Dr. Collighan, who mentioned that nonparticulate steroids had better mean pain relief, but there was no statistically significant difference between either one of the groups' degrees of pain relief. The improvement in activities exhibits a positive Pearson correlation in both particulate and nonparticulate steroids, but the correlation …
- Published
- 2011
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147. Involvement of Selective Alpha-2 Adrenoreceptor in Sympathetically Maintained Pain
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Sang Ho Lee, Chan Hong Park, and An Yong
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Sympathetic nervous system ,Clinical Article ,Visual analogue scale ,business.industry ,medicine.anatomical_structure ,Phentolamine ,Allodynia ,McGill Pain Questionnaire ,Anesthesia ,Neuropathic pain ,Hyperalgesia ,medicine ,medicine.symptom ,business ,Burning Pain ,medicine.drug - Abstract
Objective : Peripheral nerve injury often leads to neuropathic pain, which is characterized by burning pain, allodynia, and hyperalgesia. The role of the sympathetic nervous system in neuropathic pain is a complex and controversial issue. It is generally accepted that the alpha adrenoreceptor (AR) in sympathetic nerve system plays a significant role in the maintenance of pain. Among alpha adrenoreceptor, alpha-1 receptors play a major role in the sympathetic mediated pain. The primary goal of this study is to test the hypothesis that sympathetically maintained pain involves peripheral alpha-2 receptors in human. Methods : The study was a randomized, prospective, double-blinded, crossover study involving twenty patients. The treatments were : Yohimbine (30 mg mixed in 500 mL normal saline), and Phentolamine (1 mg/kg in 500 mL normal saline) in 500 mL normal saline at 70 mL/hr initially then titrated. The patients underwent infusions on three different appointments, at least one month apart. Thus, all patients received all 2 treatments. Pain measurement was by visual analogue scale, neuropathic pain questionnaire, and McGill pain questionnaire. Results : There were significant decreases in the visual analogue scale, neuropathic score, McGill pain score of yohimnine, and phentolamine. Conclusion : We conclude that alpha-2 adrenoreceptor, along with alpha-2 adrenoreceptor, may be play role in sympathetically maintained pain in
- Published
- 2010
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148. Anterior Epidural Irrigation in a Lumbar Spinal Stenosis Patient
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Chan Hong Park, Jun Seok Lee, and Hong Tae Kwon
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medicine.medical_specialty ,Anesthesiology and Pain Medicine ,Spinal stenosis ,business.industry ,Anesthesia ,medicine ,Lumbar spinal stenosis ,medicine.disease ,business ,Surgery ,Vas score - Abstract
척추관 협착증은 주로 노인에서 발생하는 흔한 질환으로 척추관이나 신경근 통로부, 또는 척추 사이 구멍(intervertebral foramen)이 추간판이나 후관절의 퇴행성 변화로 좁아져 서 신경근을 압박하여 증상이 발현되며, 요하지통의 주요한 원인이 되는 질환이다. 퇴행성 척추관 협착증 환자들은 수 술을 시행하기도 하나 대부분 나이가 많아 수술보다는 대 증요법 등으로 치료를 하고 있다. 그러나 이러한 치료에 도 증상의 호전이 없거나 효과가 있어도 매우 짧은 경우가 있다. 특히 대증요법 중 전 경막외강(anterior epidural space) 스테로이드 요법을 시행하여도 치료에 불응하는 경우에는 협착 부위를 중심으로 경막과 후종인대 사이가 유착되어 좁아진 부위에 충분히 약물이 도달하지 못하기 때문으로 생각된다. 전 경막외강 차단술은 많이 알려져 있고 널리 시 행되고 있지만 전 경막외강에 카테터를 삽입하여 그 효과 를 보고한 예를 국내는 물론 국외에서도 찾아보기 어렵다. 이에 저자들은 척추관 협착증 환자에서 카테터를 이용하 여 전 경막외강을 세정하여 임상적 효과를 확인하고자 하 였다.
- Published
- 2006
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149. Difficult Intubation due to Low Located and Right Deviated Thyroid Cartilage: A case report
- Author
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Jeong Kyu Kim, Ho Young Kim, Chan Hong Park, Jin Yong Chung, Bong Il Kim, and Woon Seok Rho
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Larynx ,Epiglottis ,medicine.medical_specialty ,Glottis ,business.industry ,medicine.medical_treatment ,Thyroid cartilage ,Thyromental distance ,Surgery ,Anesthesiology and Pain Medicine ,medicine.anatomical_structure ,Discectomy ,medicine ,Intubation ,business ,Airway - Abstract
We report a case of difficult intubation due to a low located thyroid cartilage and a left deviated glottis abnormality. A 35-year-old woman was scheduled to undergo a laminectomy and discectomy for a L4-5 disc herniation. After injecting intravenous induction agents and muscle relaxant, intubation was attempted with a direct laryngoscope. However, no vocal cords were seen and only the epiglottis was seen albeit only slightly. According to Cormack and Lehane`s grading, the patient was grade III. Although intubation was re-attempted after changing the anesthesiologist and device such as a light wand, the endotracheal tube could not be advanced below the epiglottis because of resistance. When patient was rechecked, her thyroid cartilage was located abnormally low and the thyromental distance was 14.5 cm. In addition, the preoperative chest X-ray revealed her airway to be deviated to the left. Intubation could be successfully performed after additional 100% oxygen mask ventilation. An otolaryngologic examination revealed that the glottic opening was deviated to the left, and ventricle of the larynx, which is normally not seen with a laryngocope was located to the center. It is believed that the reason for resistance of the advancing endotracheal tube was a centrally located ventricle of the larynx. (Korean J Anesthesiol 2006; 51: 742~5)
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- 2006
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150. A Case of Asystolic Cardiac Arrest in the Sitting Position for Shoulder Arthroscopy using an Interscalene Block: A case report
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Chan Hong Park, Hong Tae Kwon, and Woon Seok Roh
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Shoulder arthroscopy ,medicine.medical_specialty ,Shoulder surgery ,Side effect ,business.industry ,medicine.medical_treatment ,Sitting ,medicine.disease ,Surgery ,Position (obstetrics) ,Anesthesiology and Pain Medicine ,Regional anesthesia ,Anesthesia ,Medicine ,business ,Vasovagal syncope ,Interscalene block - Abstract
An interscalene block for shoulder surgery provides excellent surgical conditions and is well received by patients. However, a combination of the sitting position, regional anesthesia, an awake patient, and a surgical procedure can result in another side effect, vasovagal episodes, which may lead to cardiac arrest in extreme cases. We experienced a case of 32-year-old male patient with a severe vasovagal episode that led to asystolic cardiac arrest 15 minutes after the changing to the sitting position under an interscalene block for shoulder arthroscopic surgery. (Korean J Anesthesiol 2006; 51: 383~6)
- Published
- 2006
- Full Text
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