65 results on '"Hee Su Park"'
Search Results
2. Targeting High Mobility Group Box-1 (HMGB1) Promotes Cell Death in Myelodysplastic Syndrome
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Angel Y.F. Kam, Hee Su Park, Chad M. McCall, David A. Rizzieri, Sadhna O. Piryani, and Phuong L. Doan
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0301 basic medicine ,Cancer Research ,Programmed cell death ,Cell Survival ,Azacitidine ,CD34 ,Gene Expression ,Decitabine ,Apoptosis ,chemical and pharmacologic phenomena ,Article ,Immunophenotyping ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Cell Line, Tumor ,hemic and lymphatic diseases ,Animals ,Humans ,Medicine ,DNA Breaks, Double-Stranded ,HMGB1 Protein ,Mice, Knockout ,Innate immune system ,business.industry ,Gene Expression Profiling ,Toll-Like Receptors ,Sivelestat ,NF-kappa B ,Immunohistochemistry ,Immunity, Innate ,Haematopoiesis ,030104 developmental biology ,Oncology ,chemistry ,Myelodysplastic Syndromes ,030220 oncology & carcinogenesis ,Mutation ,Cancer research ,Disease Susceptibility ,business ,medicine.drug - Abstract
Purpose: Myelodysplastic syndrome (MDS) is associated with a dysregulated innate immune system. The purpose of this study was to determine whether modulation of the innate immune system via high mobility group box-1 (HMGB1) could reduce cell viability in MDS. Experimental Design: We quantified HMGB1 in an MDS cell line MDS-L and in primary MDS cells compared with nonmalignant hematopoietic cells. We performed loss-of-function studies of HMGB1 using pooled siRNAs and a small-molecule inhibitor sivelestat compared with standard chemotherapy. We measured levels of engraftment of MDS-L cells in NOD-scidIL2Rgnull (NSG) mice following treatment with sivelestat. Mechanistically, we interrogated cell survival pathways and 45 targets within the NFκB pathway using both protein analysis and a proteome profiler array. Results: We discovered that HMGB1 had increased expression in both MDS-L cells and in primary CD34+ MDS cells compared with healthy CD34+ hematopoietic cells. Sivelestat impaired MDS cell expansion, increased cellular death, and spared healthy hematopoietic cells. MDS-L marrow engraftment is reduced significantly at 17 weeks following treatment with sivelestat compared with control mice. Treatment of CD34+ MDS cells with sivelestat and azacitidine or decitabine was additive to increase apoptotic cell death compared with chemotherapy alone. Sivelestat promoted apoptosis with increased expression of PUMA, activated caspase 3, and increased DNA double-strand breaks. Inhibition of HMGB1 reduced levels of Toll-like receptors (TLR) and suppressed activation of NFκB in MDS-L cells. Conclusions: Inhibition of HMGB1 could promote MDS cell death and alter innate immune responses via suppression of NFκB pathways.
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- 2019
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3. Cladding mode analysis and experimental acousto-optic mode conversion for dynamic inter-core routing in a four-core fiber
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Kwang Yong Song, Jae Hyeong Youn, and Hee Su Park
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Core (optical fiber) ,Coupling ,Materials science ,business.industry ,Mode (statistics) ,Physics::Optics ,Optoelectronics ,Fiber ,Routing (electronic design automation) ,business ,Cladding (fiber optics) ,Cladding mode ,Refractive index - Abstract
High-efficiency and wavelength-selective excitation of higher-order cladding modes in a four-core fiber is implemented using an acousto-optic mode converter. Dynamic inter-core routing through core-to-cladding-to-core three-mode coherent coupling is demonstrated with good agreement with theory.
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- 2021
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4. Vaccine Development: From Laboratory to Policy
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Eliana L Samuels, Joseph A. Bocchini, and Hee Su Park
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Vaccine safety ,Licensure ,medicine.medical_specialty ,2019-20 coronavirus outbreak ,Clinical Trials as Topic ,Safety Management ,Vaccines ,Coronavirus disease 2019 (COVID-19) ,business.industry ,United States Food and Drug Administration ,Public health ,Public relations ,United States ,Pediatrics, Perinatology and Child Health ,Pandemic ,Drug approval ,medicine ,Product Surveillance, Postmarketing ,Humans ,Public acceptance ,business ,Drug Approval - Abstract
Vaccines are one of the greatest public health achievements, protecting children and adults against numerous infectious diseases; however, the complex, rigorous process of vaccine development is unknown to many. A candidate vaccine undergoes extensive evaluation of safety and efficacy to meet licensure requirements before recommendations for use become policy. This time-consuming process involves an intricate collaboration among academia, public and private organizations, and federal agencies to ensure that safety is prioritized in every step. Vaccine safety continues to be monitored after licensure through a robust system. Yet, vaccine hesitancy remains a major challenge, especially now with the coronavirus disease 2019 (COVID-19) pandemic and concerns about the speed with which candidate vaccines are being developed. This article reviews the vaccine development process and the systems in place to ensure safety and effectiveness. A better understanding of these topics is necessary to address concerns and improve public acceptance of all vaccines, particularly COVID-19 vaccines. [ Pediatr Ann . 2020;49(12):e509–e515.]
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- 2020
5. Temporal Multiplexing of Heralded Single Photon Sources Using Optical Fiber Delays
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Eunjoo Lee, Sang Min Lee, and Hee Su Park
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Physics ,Photon ,Optics ,Optical fiber ,business.industry ,law ,Temporal multiplexing ,business ,law.invention - Abstract
We demonstrate time-multiplexing of heralded single-photon sources using switchable optical fiber d elay l ines a ided b y p olarization-space m ultiplexing. Relative-multiplexing HOM interferometry tests the indistinguishability of output photons.
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- 2020
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6. Acousto-optic generation of orbital angular momentum states of light in a tapered optical fiber
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Changkeun Song, Kwang Yong Song, Hee Su Park, and Byoung Yoon Kim
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Physics ,Angular momentum ,Optical fiber ,business.industry ,Degenerate energy levels ,Physics::Optics ,General Physics and Astronomy ,02 engineering and technology ,Acoustic wave ,Interference (wave propagation) ,law.invention ,020210 optoelectronics & photonics ,Optics ,law ,Excited state ,Reference beam ,0202 electrical engineering, electronic engineering, information engineering ,General Materials Science ,business ,Excitation - Abstract
We demonstrate an acousto-optic mode converter based on a tapered optical fiber to efficiently generate orbital angular momentum states of light. In our scheme an acoustic wave is deployed to the waist of tapered optical fiber where two degenerate HE21 modes leading to +1 and −1 orbital angular momentum eigen-modes are resonantly excited. The excitation of TM01 and TE01 modes is suppressed by enlarging the intermodal index difference between near-degenerate spatial modes. Numerical calculation for optimization of the taper diameter is provided. The experimental characterization of generated states is performed by analyzing the output far-field pattern and the spatial interference fringes with a uniform reference beam.
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- 2018
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7. Effect of Hand-free 'Chin Tuck against Resistance (CTAR)' Exercise on Hyoid Bone Movement and the Degree of Aspiration in Stroke Patients with Dysphagia: A Report of 2 Cases
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YunHo Kim, Dooho Lee, Na-Kyoung Hwang, Sang Hoon Jung, Dong-Hwan Oh, Yong Hwa Kwon, Hee-Su Park, Hee-Jung Kim, and Nami Han
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Orthodontics ,Stroke patient ,business.industry ,Hyoid bone ,medicine.disease ,Dysphagia ,Chin ,medicine.anatomical_structure ,Swallowing ,medicine ,Suprahyoid muscles ,medicine.symptom ,business ,Stroke - Published
- 2018
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8. Azimuth-Rotated Splicings of a Four-Core Optical Fiber for Inter-Core Group Delay Compensation
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Hee Su Park, Eunjoo Lee, and Hee Jung Lee
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Physics ,Optical fiber ,business.industry ,Physics::Optics ,02 engineering and technology ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Compensation (engineering) ,law.invention ,010309 optics ,Core (optical fiber) ,Azimuth ,Interferometry ,020210 optoelectronics & photonics ,Optics ,law ,Differential group delay ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Fiber ,Electrical and Electronic Engineering ,business ,Group delay and phase delay - Abstract
This letter presents an experimental method to compensate for the differential group delay between the core modes in a multi-core fiber. Optical fiber sections are sequentially spliced with azimuthal offsets such that light initially launched to any cores can propagate through the combination of the same lengths of different cores, resulting in ideally uniform group delay. The differential group delays before and after the compensation are measured by wavelength-domain Mach–Zehnder interferometry through multi-core fiber sections. The experimental results show that the group delay compensation is practically limited by non-uniformity of the multi-core fiber.
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- 2017
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9. Sensor Fusion Docking System of Drone and Ground Vehicles Using Image Object Detection
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Hee-Su Park, Ji-Hun Shin, Jonghwan Beck, Se-Ryeong Oh, and Sanghoon Kim
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business.industry ,Docking (molecular) ,Computer science ,Template matching ,Computer vision ,Artificial intelligence ,Ground vehicles ,business ,Sensor fusion ,Drone ,Image object - Published
- 2017
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10. Measurement of bending-induced birefringence in a hollow-core photonic crystal fiber
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Byoung Yoon Kim, Hee Su Park, Dongyun Chung, and Fabian Rotermund
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Hollow core ,Quantitative Biology::Biomolecules ,Birefringence ,Materials science ,Fast axis ,Scanning electron microscope ,business.industry ,Inverse-square law ,Bend radius ,Physics::Optics ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Polarization (waves) ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,010309 optics ,Optics ,0103 physical sciences ,Physics::Accelerator Physics ,0210 nano-technology ,business ,Photonic-crystal fiber - Abstract
We report the measurement of bending-induced birefringence in the presence of large intrinsic birefringence in a hollow-core photonic crystal fiber (HC-PCF). The fast axis of bending-induced birefringence was found to be normal to the bending plane, in contrast to the conventional fiber case. The dependence of the induced birefringence on the bending radius was also different from the typical inverse square law. Possibilities and design criteria for polarization controllers using bending-induced birefringence in HC-PCFs are presented.
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- 2019
11. Relative time multiplexing of heralded telecom-band single-photon sources using switchable optical fiber delays
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Sang Min Lee, Hee Su Park, and Eunjoo Lee
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Physics ,Optical fiber ,business.industry ,Physics::Optics ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Interference (wave propagation) ,01 natural sciences ,Optical switch ,Atomic and Molecular Physics, and Optics ,law.invention ,Coherence length ,010309 optics ,Interferometry ,Optics ,Optical path ,Path length ,law ,0103 physical sciences ,Photonics ,0210 nano-technology ,business - Abstract
We experimentally demonstrate a time-multiplexing method for pulse-pumped heralded single-photon sources using switchable optical fiber delay lines. The optical fibers constitute a 32-channel binary-division photon buffer that can multiplex time slots into single temporal mode to enhance single-photon generation rate without increasing multi-photon noise. Relative time multiplexing using the same actively controlled variable delay realizes Hong-Ou-Mandel interferometry by two photons produced in arbitrary two time-bins. The interference dip depth in good agreement with theory verifies path length matching within the photonic coherence length and dispersion compensation of the optical fiber delay sections. We independently confirm by low-coherence interferometry that the internal optical path lengths of the optical switches are constant during the switching operations.
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- 2019
12. Urinary neutrophil gelatinase-associated lipocalin as a biomarker of acute kidney injury in sepsis patients in the emergency department
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Hee Su Park, Jin Young Kim, Sin Young Kim, Sang Kuk Han, Jong Won Kim, Dae Young Hong, Kyeong Ryong Lee, and Sang O Park
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0301 basic medicine ,Male ,medicine.medical_specialty ,Urinary system ,Clinical Biochemistry ,Lipocalin ,urologic and male genital diseases ,Biochemistry ,Gastroenterology ,Procalcitonin ,Sepsis ,03 medical and health sciences ,0302 clinical medicine ,Lipocalin-2 ,Internal medicine ,medicine ,Humans ,Aged ,Aged, 80 and over ,business.industry ,Septic shock ,Biochemistry (medical) ,Acute kidney injury ,General Medicine ,Emergency department ,Acute Kidney Injury ,Middle Aged ,medicine.disease ,Prognosis ,female genital diseases and pregnancy complications ,030104 developmental biology ,ROC Curve ,030220 oncology & carcinogenesis ,Biomarker (medicine) ,Female ,business ,Emergency Service, Hospital ,Biomarkers - Abstract
Plasma neutrophil gelatinase-associated lipocalin (NGAL) is a useful biomarker for predicting acute kidney injury (AKI). The purpose of this study was to evaluate the diagnostic performance of urinary NGAL in predicting AKI in sepsis patients in the emergency department.A total of 140 patients were enrolled. We compared serum procalcitonin and urinary NGAL concentrations between patients with local infection, sepsis, and septic shock, and between patients who did and did not develop AKI with sepsis. Receiver-operating characteristic curve analysis was used to evaluate the ability to predict AKI in sepsis patients.Both serum procalcitonin and urinary NGAL concentrations were significantly higher in the sepsis and septic shock groups than in the local infection group (both p 0.001). In sepsis patients, serum procalcitonin and urinary NGAL concentrations were higher in AKI patients than in those without AKI (p = 0.006, p 0.001, respectively). The area under the curve for predicting of AKI was higher for a urinary NGAL of 0.820 (95% confidence interval (CI) 0.721-0.895) than for a serum procalcitonin concentration of 0.76 (95% CI 0.597-0.800).Urinary NGAL concentration may predict AKI in patients with sepsis in the emergency department.
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- 2019
13. Analysis on Transition between Index- and Bandgap-guided Modes in Photonic Crystal Fiber
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Kee Suk Hong, Sun Do Lim, Seung Kwan Kim, and Hee Su Park
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Mode volume ,Materials science ,Birefringence ,Guided-mode resonance ,business.industry ,Physics::Optics ,02 engineering and technology ,Microstructured optical fiber ,01 natural sciences ,Yablonovite ,Atomic and Molecular Physics, and Optics ,010309 optics ,020210 optoelectronics & photonics ,0103 physical sciences ,Dispersion (optics) ,0202 electrical engineering, electronic engineering, information engineering ,Optoelectronics ,business ,Photonic crystal ,Photonic-crystal fiber - Abstract
We calculate optical properties of guided modes of a hybrid-guiding photonic crystal fiber. The design and modeling of such hybrid-guiding PCF is made by replacing air holes with inserts of high refractive index material layer by layer in order. The optical properties such as mode intensity profile, mode dispersion, optical birefringence, confinement loss, and chromatic dispersion during transition of the guiding mechanism are analyzed and discussed. The guided modes in the hybrid-guiding region are also compared with those of reference index-guiding and bandgap-guiding photonic crystal fibers.
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- 2016
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14. Numerical calculation of the operation wavelength range of a polarization controller based on rotatable wave plates
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Aditya N. Sharma and Hee Su Park
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Materials science ,Optical fiber ,Birefringence ,Polarization rotator ,Wavelength range ,business.industry ,Numerical analysis ,Polarization-maintaining optical fiber ,Polarization (waves) ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,010305 fluids & plasmas ,Electronic, Optical and Magnetic Materials ,law.invention ,Polarization controller ,Optics ,Control and Systems Engineering ,law ,0103 physical sciences ,Condensed Matter::Strongly Correlated Electrons ,Electrical and Electronic Engineering ,010306 general physics ,business ,Instrumentation - Abstract
We calculate the operation wavelength range of polarization controllers based on rotating wave plates such as paddle-type optical fiber devices. The coverages over arbitrary polarization conversion or arbitrary birefringence compensation are numerically estimated. The results present the acceptable phase retardation range of polarization controllers composed of two quarter-wave plates or a quarter-half-quarter-wave plate combination, and thereby determines the operation wavelength range of a given design. We further prove that a quarter-quarter-half-wave-plate combination is also an arbitrary birefringence compensator as well as a conventional quarter-half-quarter-wave-plate combination, and show that the two configurations have the identical range of acceptable phase retardance within the uncertainty of our numerical method.
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- 2016
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15. A comparative study of the methods for measuring lumbar intervertebral gap using radiographic images
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Hee Su Park, Cheolwoong Ko, and Tae Soo Bae
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Orthodontics ,030222 orthopedics ,Supine position ,business.industry ,Mechanical Engineering ,Radiography ,Lumbar vertebrae ,Industrial and Manufacturing Engineering ,03 medical and health sciences ,0302 clinical medicine ,Lumbar ,medicine.anatomical_structure ,Medicine ,Lumbar spine ,Electrical and Electronic Engineering ,business ,030217 neurology & neurosurgery - Abstract
Anterior and posterior intervertebral gap of lumbar spine is important when developing the spinal implants regarding lumbar system. However, the measuring methods continue to be still controversial because of the absence of a standardized measurement. The objective of this study is to propose novel methods of measuring lumbar intervertebral gap and to conduct comparative analysis with other measuring methods. We took the lateral radiography images of 20 males taking the postures of supine, seat and standup. The anterior intervertebral gap and posterior intervertebral gap were measured with three different methods and two pre-existing methods. The comparison of results from three different measuring methods and two pre-existing methods showed that the difference at the anterior intervertebral gap was mostly statistically significant. This study suggests that it is necessary to consider the clinical meaning of the difference among measuring methods in order to establish a database to fabricate spine implants and to make efforts to improve measuring methods in the future.
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- 2016
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16. Wavelength-scanning calibration of detection efficiency of single photon detectors by direct comparison with a photodiode
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Hee Jung Lee, Hee Su Park, Han Seb Moon, Dong-Hoon Lee, Seongchong Park, Myoungsik Cha, Heonoh Kim, and Kee Suk Hong
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Attenuator (electronics) ,Physics ,Photocurrent ,Laser diode ,business.industry ,Amplifier ,General Engineering ,01 natural sciences ,law.invention ,Photodiode ,010309 optics ,Wavelength ,Optics ,Band-pass filter ,law ,0103 physical sciences ,010306 general physics ,business ,Beam splitter - Abstract
We present a practical calibration method of the detection efficiency (DE) of single photon detectors (SPDs) in a wide wavelength range from 480 nm to 840 nm. The setup consists of a GaN laser diode emitting a broadband luminescence, a tunable bandpass filter, a beam splitter, and a switched integrating amplifier which can measure the photocurrent down to the 100 fA level. The SPD under test with a fibre-coupled beam input is directly compared with a reference photodiode without using any calibrated attenuator. The relative standard uncertainty of the DE of the SPD is evaluated to be from 0.8% to 2.2% varying with wavelength (k = 1).
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- 2016
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17. Systemic Lupus Erythematosus Presenting with Idiopathic Retroperitoneal Fibrosis
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Soo Yoon Moon, Ji Young Woo, Jong Jin Yoo, Kyung Up Kim, Hee Su Park, Hye Mi Oh, and Jae Kyun Choi
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030203 arthritis & rheumatology ,03 medical and health sciences ,medicine.medical_specialty ,0302 clinical medicine ,business.industry ,General surgery ,Medicine ,030212 general & internal medicine ,Creative commons ,Idiopathic Retroperitoneal Fibrosis ,business ,License ,Anti-SSA/Ro autoantibodies - Abstract
177 Copyrightc 2016 The Korean Association of Internal Medicine This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Received: 2015. 8. 24 Revised: 2015. 9. 10 Accepted: 2015. 9. 16
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- 2016
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18. Deterministic Secure Quantum Communication on the BB84 System
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Jeong Younchang, Hee Su Park, Changho Hong, Jingak Jang, and Se-Wan Ji
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Computer science ,Optical communication ,General Physics and Astronomy ,lcsh:Astrophysics ,01 natural sciences ,Article ,010305 fluids & plasmas ,lcsh:QB460-466 ,0103 physical sciences ,lcsh:Science ,010306 general physics ,Quantum information science ,BB84 ,Quantum ,Protocol (object-oriented programming) ,Computer Science::Cryptography and Security ,optical communication ,Authentication ,Shuffling ,business.industry ,quantum mechanics ,lcsh:QC1-999 ,Quantum cryptography ,quantum cryptography ,lcsh:Q ,business ,lcsh:Physics ,Computer network - Abstract
In this paper, we propose a deterministic secure quantum communication (DSQC) protocol based on the BB84 system. We developed this protocol to include quantum entity authentication in the DSQC procedure. By first performing quantum entity authentication, it was possible to prevent third-party intervention. We demonstrate the security of the proposed protocol against the intercept-and-re-send attack and the entanglement-and-measure attack. Implementation of this protocol was demonstrated for quantum channels of various lengths. Especially, we propose the use of the multiple generation and shuffling method to prevent a loss of message in the experiment.
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- 2020
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19. Experimental Demonstration of Four-Dimensional Photonic Spatial Entanglement between Multi-core Optical Fibres
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Hee Su Park, Hee Jung Lee, and Sang-Kyung Choi
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Photon ,Optical fiber ,Science ,02 engineering and technology ,Quantum entanglement ,01 natural sciences ,Article ,law.invention ,Quantum nonlocality ,Optics ,Quantum state ,law ,0103 physical sciences ,010306 general physics ,Physics ,Multidisciplinary ,Spatial light modulator ,business.industry ,Quantum tomography ,021001 nanoscience & nanotechnology ,Medicine ,Photonics ,0210 nano-technology ,business - Abstract
Fibre transport of multi-dimensional photonic quantum states promises high information capacity per photon without space restriction. This work experimentally demonstrates transmission of spatial ququarts through multi-core optical fibres and measurement of the entanglement between two fibres with quantum state analyzers, each composed of a spatial light modulator and a single-mode fibre. Quantum state tomography reconstructs the four-dimension entangled state that verifies the nonlocality through concurrences in two-dimensional subspaces, a lower bound of four-dimensional concurrence and a Bell-type CGLMP inequality.
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- 2017
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20. Controlling the spatial entanglement between multi-core optical fibers based on pump beam shaping of SPDC
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Hee Jung Lee and Hee Su Park
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Optical fiber ,Photon ,Materials science ,business.industry ,Physics::Optics ,Quantum channel ,Quantum entanglement ,Laser ,law.invention ,Optics ,Spontaneous parametric down-conversion ,law ,Optoelectronics ,Laser beam quality ,business ,Parametric statistics - Abstract
We demonstrate an experimental method to control four-dimensional spatially entangled states between two multi-core optical fibers based on spatial beam shaping of a laser that pumps spontaneous parametric down-conversion.
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- 2017
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21. Acoustooptic Generation and Characterization of the Higher Order Modes in a Four-Mode Fiber for Mode-Division Multiplexed Transmission
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Kwang Yong Song, Byoung Yoon Kim, Du-Ri Song, and Hee Su Park
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Mode scrambler ,Physics ,Mode volume ,Optics ,Multi-mode optical fiber ,business.industry ,Single-mode optical fiber ,Dispersion-shifted fiber ,Polarization-maintaining optical fiber ,Radiation mode ,business ,Graded-index fiber ,Atomic and Molecular Physics, and Optics - Abstract
We demonstrate a highly efficient acoustooptic mode converter for selective excitation of the higher-order modes in a four-mode fiber which guides the LP01, LP11, LP21, and LP02 modes at telecommunication wavelengths. The coupling efficiency and the mode extinction ratio are measured by analyzing the output far-field patterns. The acoustic resonance frequencies and the operating bandwidths are compared with the theoretical results, by which the modal characteristics, the core diameter, and the core-cladding index difference are estimated.
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- 2014
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22. Comparison of orbicularis oris muscle strength and endurance in young and elderly adults
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Hee Jeong Kim, Dong-Hwan Oh, Jae-Young Park, Hee-Su Park, and Jin-Uk Kim
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medicine.medical_specialty ,business.industry ,viruses ,Orbicularis oris muscle ,Physical Therapy, Sports Therapy and Rehabilitation ,biochemical phenomena, metabolism, and nutrition ,Endurance ,03 medical and health sciences ,0302 clinical medicine ,Physical medicine and rehabilitation ,Younger adults ,Maximal strength ,medicine ,Swallowing therapy ,Original Article ,030212 general & internal medicine ,Elderly adults ,Strength ,Young adult ,business ,030217 neurology & neurosurgery - Abstract
[Purpose] The purpose of this study was to compare the strength and endurance of the orbicularis oris muscle in healthy Korean (young vs. elderly adults). [Participants and Methods] A total of 60 participants (30 young adults and 30 elderly adults) were recruited. The Iowa Oral Performance Instrument was used to measure orbicularis oris muscle maximal strength and endurance. [Results] Elderly adults showed significantly lower orbicularis oris muscle strength and endurance than younger adults. [Conclusion] This study confirmed a significant age-related decrease in orbicularis oris muscle strength and endurance. The data collected will be useful as a basis for future on speech and swallowing therapy.
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- 2018
23. Effect of orbicularis oris muscle training on muscle strength and lip closure function in patients with stroke and swallowing disorder
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Hee Jeong Kim, Hee Su Choi, Jae-Young Park, Hee-Su Park, and Young-Hwa Kwon
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Orthodontics ,030506 rehabilitation ,Palsy ,business.industry ,Repetition maximum ,Orbicularis oris muscle ,Physical Therapy, Sports Therapy and Rehabilitation ,Swallowing ,medicine.disease ,Stroke ,stomatognathic diseases ,03 medical and health sciences ,0302 clinical medicine ,Muscle strength ,medicine ,Original Article ,In patient ,Lip closure ,0305 other medical science ,business ,030217 neurology & neurosurgery - Abstract
[Purpose] We aimed to investigate the effect of resistance training of the orbicularis oris muscles on lip muscle strength and closure function in patients with swallowing disorder with facial palsy after stroke. [Participants and Methods] This study recruited 10 patients with swallowing disorder and facial palsy after stroke. All the participants received orbicularis oris muscle training at an intensity of 70% of 1 repetition maximum by using an Iowa oral performance instrument. Muscle strength and lip closure function were evaluated after orbicularis oris muscle training. [Results] After the intervention, the orbicularis oris muscle strength showed a statistically significant increase from 20.5 ± 5.15 to 25.3 ± 4.2 kilopascal. Lip closure function showed a statistically significant improvement from 2.6 ± 1.5 to 1.2 ± 1.0. [Conclusion] This study recommends to train at an intensity of 70% of 1 repetition maximum for 4 weeks to increase theorbicularis oris muscle strength and improve lip closure function.
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- 2018
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24. Detection efficiency measurement of single photon avalanche photodiodes by using a focused monochromatic beam tunable from 250 nm to 1000 nm
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Seongchong Park, Kee-Suk Hong, Han Seb Moon, Dong-Hoon Lee, J. S. Borbely, In-Ho Bae, Hee Jung Lee, and Hee Su Park
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Materials science ,Photon ,Spatial filter ,Physics::Instrumentation and Detectors ,business.industry ,Detector ,General Engineering ,Radiant energy ,Avalanche photodiode ,01 natural sciences ,Photodiode ,law.invention ,010309 optics ,Responsivity ,Optics ,law ,0103 physical sciences ,Monochromatic color ,010306 general physics ,business - Abstract
We demonstrate the measurement of detection efficiency, the probability for the successful detection of a single photon incident on a detector, in a wide wavelength range from 250 nm to 1000 nm. The method is based on the responsivity comparison of two detectors by using a tunable monochromatic light source at a radiant power controlled to the pico-Watt level. As the reference detector, a photodiode with a switched integrating amplifier is used, whose spectral responsivity is calibrated at a photo-current level of pico-Ampere. A fibre-based spatial filter is used to form a beam focus that is focused to a diameter of less than 100 µm at the detector under test. The typical uncertainty of the detection-efficiency measurement for a Si-based single photon avalanche photodiode is evaluated to be less than 1% as a relative standard uncertainty (k = 1), which is currently limited by the characteristics of the tunable source.
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- 2019
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25. Primary Thyroid Angiosarcoma with Tracheal Invasion
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Eun-Jae Chung, Seong-Jin Cho, Yousang Ko, Yong Bum Park, So Young Park, Young Soo Rho, Eun Kyung Mo, Haemi Oh, Kyung Up Kim, Hee Su Park, Jae Kyun Choi, Soo Yoon Moon, and Ji Young Woo
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medicine.medical_specialty ,Hemoptysis ,Thyroid Angiosarcoma ,Tumor resection ,Hemangiosarcoma ,03 medical and health sciences ,0302 clinical medicine ,Bronchoscopy ,Biopsy ,Internal Medicine ,Medicine ,Humans ,Neoplasm Invasiveness ,Thyroid Neoplasms ,neoplasms ,Pathological ,medicine.diagnostic_test ,business.industry ,General Medicine ,respiratory system ,Middle Aged ,medicine.disease ,digestive system diseases ,Trachea ,medicine.anatomical_structure ,Otorhinolaryngology ,030220 oncology & carcinogenesis ,Female ,Radiology ,business ,Tomography, X-Ray Computed ,030217 neurology & neurosurgery ,Blood vessel - Abstract
A 48-year-old woman was referred to our clinic because she had been experiencing hemoptysis for 1 month. Chest computed tomography revealed a small portion of a thyroid mass was penetrating the trachea. Bronchoscopy revealed a blood vessel covered mass located in her trachea. The presence of a malignant tumor was confirmed by a biopsy. The patient was referred to the otolaryngology department for tumor resection and a pathological evaluation identified the thyroid angiosarcoma with tracheal invasion. Angiosarcomas have a poor prognosis, but the patient has not experienced any recurrence two years after surgery. A very rare case of primary thyroid angiosarcoma with tracheal invasion was cured successfully.
- Published
- 2016
26. Linear optical scheme for producing polarization-entangled NOON states
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Hyunchul Nha, Hee Su Park, Tomasz Paterek, and Su-Yong Lee
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Physics ,Quantum Physics ,business.industry ,FOS: Physical sciences ,Noon ,Polarization (waves) ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Optics ,Quantum mechanics ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Quantum Physics (quant-ph) ,NOON state ,business - Abstract
We propose a linear optical scheme that can conditionally generate high NOON states using polarization modes. This scheme provides advantages over the previous proposals on path-entangled NOON states in view of success probability or required resources of optical elements. We also investigate two experimental schemes feasible within existing technology that can produce the NOON-like or the NOON state for N = 4., Published version, 5 pages, 4 figures
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- 2012
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27. Effect of mirror therapy and electrical stimulation on upper extremity function in stroke with hemiplegic patient: a pilot study
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Donghwan Oh, Jeong-Hoon Lee, Hee-Su Park, Doo-Ho Lee, and Young-Rim Paik
- Subjects
030506 rehabilitation ,medicine.medical_specialty ,Stroke patient ,business.industry ,Fugl meyer ,Physical Therapy, Sports Therapy and Rehabilitation ,Stimulation ,medicine.disease ,Upper Extremity Part ,Mirror therapy ,Stroke ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,Physical medicine and rehabilitation ,Electrical stimulation ,medicine ,Upper limb ,Original Article ,Function recovery ,0305 other medical science ,business ,030217 neurology & neurosurgery - Abstract
[Purpose] This study investigated the effects of mirror therapy and neuromuscular electrical stimulation on upper extremity function in stroke patients. [Subjects and Methods] This study recruited 8 stroke patients. All patients were treated with mirror therapy and neuromuscular electrical stimulation five times per week for 4 weeks. Upper limb function evaluation was performed using upper extremity part of fugl meyer assessment. [Results] Before and after intervention, fugl meyer assessment showed significant improvement. [Conclusion] In this study, mirror therapy and neuromuscular electrical stimulation are effective methods for upper extremity function recovery in stroke patients.
- Published
- 2017
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28. Inhibition of High Mobility Group Box-1 (HMGB1) Eradicates Human Myelodysplastic Syndrome
- Author
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Chad M. McCall, Phuong L. Doan, Sadhna O. Piryani, Nelson J. Chao, Angel Y.F. Kam, and Hee Su Park
- Subjects
Severe combined immunodeficiency ,biology ,business.industry ,Immunology ,Azacitidine ,Sivelestat ,Bone marrow failure ,CD34 ,Cell Biology ,Hematology ,medicine.disease ,Biochemistry ,Haematopoiesis ,chemistry.chemical_compound ,chemistry ,hemic and lymphatic diseases ,biology.protein ,medicine ,Cancer research ,p53 upregulated modulator of apoptosis ,Stem cell ,business ,medicine.drug - Abstract
Myelodysplastic syndrome (MDS) is a heterogeneous and pre-leukemic clonal stem cell disorder characterized by aberrant hematopoiesis and bone marrow failure. Since MDS is associated with a dysregulated innate immune system, we performed a genetic screen of the human toll-like receptor (TLR) pathway and found that high mobility group box-1 (HMGB1) was abundantly expressed in MDS. HMGB1 is a ubiquitously expressed, non-histone chromatin-binding protein. In solid cancers, high expression of HMGB1 was associated with both shortened progression-free and overall survival, but its role in hematologic malignancies is not well defined. We hypothesized that targeting HMGB1 could be therapeutic in MDS. To study HMGB1 in human MDS, we utilized a cell line, MDS-L, derived from a patient with myelodysplastic syndrome with ring sideroblasts. Morphologically, the cells display dysplastic features, including cytoplasmic vacuolation and prominent, irregular nucleoli. We found that HMGB1 was detected at high levels in both MDS-L and in primary CD34+ MDS compared to CD34+ cord blood and healthy human marrow (*p Next, we sought to pharmacologically inhibit HMGB1 signaling with sivelestat, which is a small molecule inhibitor for neutrophil elastase and HMGB1. Since sivelestat has not been studied in either normal or malignant hematopoiesis, whether it or other HMGB1 inhibitors could impact MDS is not yet defined. Following 72 h culture, HMGB1 protein levels were decreased in both MDS-L cells and in primary CD34+ MDS cells treated with 300 mg/ml sivelestat compared to cultures with vehicle alone (*p Since treatment with sivelestat could decrease both MDS cell expansion and impair the ability to generate colonies in methylcellulose assays, we sought to determine whether blocking HMGB1 could decrease MDS engraftment in NOD-scid ILR2gnull (NSG) mice. At 17 weeks, irradiated NSG mice that were transplanted with MDS-L cells treated with sivelestat demonstrated a 3.2-fold decrease in human CD45 marrow engraftment with MDS-L compared to control cultures (*p Mechanistically, sivelestat increased cellular apoptosis in cultures of MDS cells compared to control cultures (*p=0.001). This was done in part by increasing levels of p53 upregulated modulator of apoptosis (PUMA, *p=0.0003), activated caspase 3 (*p Disclosures No relevant conflicts of interest to declare.
- Published
- 2018
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29. Dead time correction in coincidence counting of photon pairs
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Hee Su Park, SK Choi, J Lee, Jy Lee, Myeong Soo Kang, and DH Lee
- Subjects
Physics ,Photon ,business.industry ,General Engineering ,Dead time ,Coincidence ,Optics ,Transmission (telecommunications) ,Control theory ,Calibration ,Range (statistics) ,Coincidence counting ,Oscilloscope ,business - Abstract
We describe two methods for evaluating the dead time of a time-to-amplitude converter (TAC). The dead time is obtained by measuring either the corresponding time interval in an oscilloscope trace or the relation between the single count rate and the coincidence count rate. Values for the TAC dead time are obtained in the range from 3.4 µs to 14.3 µs for the two methods with respective standard uncertainties of 2.9 × 10−8 s and 3.3 × 10−9 s. The TAC dead time is applied to the calibration of coincidence-counting measurements of optical transmission and photon-heralding efficiency.
- Published
- 2008
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30. Measurement of arbitrary superpositions of core modes in a multi-core fiber
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Han Seb Moon, Hee Jung Lee, Sang-Kyung Choi, and Hee Su Park
- Subjects
Physics ,Mode volume ,Multi-mode optical fiber ,Optical fiber ,business.industry ,Single-mode optical fiber ,Physics::Optics ,Polarization-maintaining optical fiber ,Graded-index fiber ,law.invention ,Optics ,law ,business ,Plastic optical fiber ,Photonic-crystal fiber - Abstract
We propose and demonstrate an experimental technique that generates and measures arbitrary superpositions of the core modes in a multi-core fiber. This technique is potentially useful for transmission of high-dimensional quantum states through optical fiber.
- Published
- 2015
- Full Text
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31. A Time-Multiplexed Heralded Single-Photon Source
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Hee Su Park, Paul G. Kwiat, Jia Jun Wong, Kevin McCusker, Fumihiro Kaneda, and Bradley G. Christensen
- Subjects
Physics ,Quantum optics ,Quantum Physics ,Photon ,business.industry ,FOS: Physical sciences ,Physics::Optics ,Optical storage ,Quantum information processing ,Multiplexing ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Single-photon source ,Photon polarization ,Optoelectronics ,Quantum information ,business ,Quantum Physics (quant-ph) - Abstract
Photons have proven to be excellent carriers of quantum information and play essential roles in numerous quantum information processing (QIP) applications. In particular, heralded single-photon sources via spontaneous parametric-down conversion (SPDC) have been a key technology for demonstrating small-scale QIP, yet their low generation efficiency is a critical limitation to furthering the scale-up of optical QIP technology. In order to efficiently overcome the probabilistic nature of SPDC, here we demonstrate time multiplexing for up to 30 time slots of a periodically pumped heralded single-photon source using a switchable low-loss optical storage cavity. We observe a maximum single-photon probability of 38.6±0.4% in periodic output time windows, corresponding to ∼6 times enhancement over a nonmultiplexed source but with no increase in the contribution of unwanted multiphoton events. Combining this time-multiplexing technique with a heralded source producing pure single-photon states should enable larger-scale optical QIP systems than previously realized.
- Published
- 2015
32. Multi-core fiber interferometer using spatial light modulators for measurement of the inter-core group index differences
- Author
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Han Seb Moon, Hee Su Park, Hee Jung Lee, and Sang-Kyung Choi
- Subjects
Physics ,Mode volume ,Multi-mode optical fiber ,business.industry ,Physics::Optics ,Polarization-maintaining optical fiber ,Long-period fiber grating ,Graded-index fiber ,Atomic and Molecular Physics, and Optics ,Optics ,Fiber Bragg grating ,Fiber optic sensor ,Dispersion-shifted fiber ,business - Abstract
We demonstrate an experimental technique to generate and measure arbitrary superpositions of core modes in a multi-core fiber. Two spatial light modulators couple the fundamental mode of a single-mode fiber with multiple-core modes of the MCF to constitute a Mach-Zehnder-type multi-path interferometer. The phase tunability of each path is verified by comparing two-, three-, and four-path interference patterns with the theory. Interference fringes in the wavelength domain estimates the inter-core group index differences with a resolution of 10(-5) using a fiber length of 1 m.
- Published
- 2015
33. Temporal Multiplexing toward Periodic and Deterministic Single-Photon Sources
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Jia Jun Wong, Paul G. Kwiat, Kevin McCusker, Bradley G. Christensen, Hee Su Park, and Fumihiro Kaneda
- Subjects
Physics ,Photon ,business.industry ,Physics::Optics ,Laser ,Multiplexing ,Optical parametric amplifier ,law.invention ,Optics ,Spontaneous parametric down-conversion ,law ,Photon polarization ,Optoelectronics ,Photonics ,business ,Parametric statistics - Abstract
Utilizing time multiplexing of a heralded single-photon source based on spontaneous parametric downconversion pumped by periodic laser pulses, we observed large enhancements in the single-photon probability.
- Published
- 2015
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- View/download PDF
34. Detection of laser-generated ultrasound based on phase demodulation technique using a fibre Fabry–Perot interferometer
- Author
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Hee Su Park, Brian Culshaw, and Graham Thursby
- Subjects
Materials science ,Optical fiber ,Physics::Instrumentation and Detectors ,business.industry ,Applied Mathematics ,Acoustics ,Detector ,Physics::Optics ,Acoustic wave ,Fibre optic gyroscope ,Laser ,law.invention ,Interferometry ,Optics ,law ,Demodulation ,business ,Instrumentation ,Engineering (miscellaneous) ,Fabry–Pérot interferometer - Abstract
This paper describes a novel non-contact laser-ultrasound system which is compact and has a high level of immunity to ambient vibration, based on the use of an optical fibre Fabry–Perot interferometer as an acoustic detector. The new optical acoustic detector was employed for measuring a high-frequency acoustic wave of small amplitude generated by a relatively low output power source using an erbium-doped fibre amplifier. Together with the characteristics of the proposed detector, the preliminary results of 80 MHz laser-ultrasound experiments on an aluminium film are described.
- Published
- 2005
- Full Text
- View/download PDF
35. Detecting Ultrasound Using Optical Fibres
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Fengzhong Dong, Graham Thursby, Brian Culshaw, Syed Atique, Hee Su Park, Daniel Betz, and B. Sorazu
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Signal processing ,Optical fiber ,Materials science ,genetic structures ,business.industry ,Detector ,Bandwidth (signal processing) ,Fibre optic gyroscope ,Atomic and Molecular Physics, and Optics ,Fault detection and isolation ,law.invention ,Optics ,Lamb waves ,law ,Ultrasonic sensor ,sense organs ,business - Abstract
Optical fibre techniques for detecting ultrasonic waves are, in principle, well established. The ultrasonic wave could impose a pressure and/or strain field on an optical fibre in its path and this pressure and/or strain modulation would in turn be observed as a change in optical delay along the fibre length. The delay change may be detected interferometrically, polarimetrically or through using the induced strain changes in Bragg gratings. The resulting fibre optic detection system can perform as well in terms of signal to noise ratio over specified bandwidths as more established piezoelectric ceramic detectors. Additionally fibre systems can also perform some signal processing, particularly beam forming, and have inherently much higher spatial and temporal bandwidth than the piezoceramic precursor. This paper explores some of the options available for the use of fibre optics in detecting ultrasound and demonstrates the elements of basic signal processing techniques including examples of source location (equivalent to fault detection) and optical fibre beam forming. Whilst these functions can be performed using piezoceramics, and indeed can be made more adaptable through electronic element by element processing on large arrays, fibre optic systems in contrast offer substantial benefits in terms of a much simplified array interconnect (only the fibre itself is required) and material compatibility especially for high performance high strain range mechanical systems.
- Published
- 2004
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- View/download PDF
36. All-fiber wavelength-tunable acoustooptic switches based on intermodal coupling in fibers
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Seok Hyun Yun, Kwang Yong Song, Hee Su Park, and Byoung Yoon Kim
- Subjects
Materials science ,Optical fiber ,business.industry ,Multiplexer ,Optical switch ,Atomic and Molecular Physics, and Optics ,law.invention ,Switching time ,Optics ,Fiber Bragg grating ,law ,Wavelength-division multiplexing ,business ,Optical add-drop multiplexer ,Passband - Abstract
In this paper, we demonstrate a novel all-fiber wavelength-tunable acoustooptic switch utilizing intermodal coupling in a two-mode fiber (TMF). Its all-fiber configuration consisting of a fiber acoustooptic tunable filter and a mode-selective coupler results in the low loss ( 50 nm, the switching time of 40 /spl mu/sec, and the crosstalk of 20 dB were achieved. By controlling the design parameters of the two-mode fiber, the 3-dB bandwidth of the switched signal was varied from 2.5 nm to >35 nm. A novel all-fiber dynamic optical add-drop multiplexer is also demonstrated using two acoustooptic switches in series.
- Published
- 2002
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37. Acousto-optic resonant coupling of three spatial modes in an opticalfiber
- Author
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Kwang Yong Song and Hee Su Park
- Subjects
Physics ,Mode volume ,Optical fiber ,business.industry ,Electromagnetically induced transparency ,Single-mode optical fiber ,Physics::Optics ,Polarization-maintaining optical fiber ,Acoustics ,Equipment Design ,Long-period fiber grating ,Micro-Electrical-Mechanical Systems ,Models, Theoretical ,Multiplexing ,Atomic and Molecular Physics, and Optics ,law.invention ,Equipment Failure Analysis ,Optics ,Transmission (telecommunications) ,law ,Optoelectronics ,Computer Simulation ,business ,Optical Fibers - Abstract
A fiber-optic analogue to an externally driven three-level quantum state is demonstrated by acousto-optic coupling of the spatial modes in a few-mode fiber. Under the condition analogous to electromagnetically induced transparency, a narrow-bandwidth transmission within an absorption band for the fundamental mode is demonstrated. The presented structure is an efficient converter between the fundamental mode and the higher-order modes that cannot be easily addressed by previous techniques, therefore can play a significant role in the next-generation space-division multiplexing communications as an arbitrarily mode-selectable router. (C) 2014 Optical Society of America
- Published
- 2014
38. Tunable Polarization-Dependent-Loss Element Based on Rotatable Birefringent Prisms and a Half-Wave Plate
- Author
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Hee Su Park, Heonoh Kim, and Sang-Kyung Choi
- Subjects
Birefringence ,Materials science ,Wavelength range ,business.industry ,Optical polarization ,Waveplate ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Interferometry ,Wavelength ,Optics ,Interference (communication) ,Optoelectronics ,Electrical and Electronic Engineering ,Polarization dependent ,business - Abstract
A novel tunable polarization-dependent-loss (PDL) element is realized using two rotatable birefringent prisms and a half-wave plate. The design is favorable for interferometric stability and is operable over a wide wavelength range. The PDL can be tuned from 0 to 35 dB for a wavelength of 780 nm. An interference visibility of 0.98 between the two principal polarizations for 0-dB loss is achieved by compensating for thickness mismatch between the prisms.
- Published
- 2009
- Full Text
- View/download PDF
39. Two-mode fiber acoustooptic tunable bandpass filter with zero frequency-shift
- Author
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Byoung Yoon Kim, Hee Su Park, and Myeong Soo Kang
- Subjects
Materials science ,Transmission dynamic ,Extinction ratio ,business.industry ,Bandwidth (signal processing) ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Wavelength ,Optics ,Band-pass filter ,Insertion loss ,Electrical and Electronic Engineering ,Zero frequency ,business ,Intensity modulation - Abstract
We propose and experimentally demonstrate a novel configuration for an acoustooptic tunable bandpass filter based on intermodal coupling in a two-mode fiber. The double-pass scheme provides zero frequency-shift, bandwidth narrowing, and enhanced extinction ratio. A 3-dB bandwidth of 2.0 nm, insertion loss of 5.6 dB, and sidelobe suppression ratio of 14 dB were achieved. The wavelength tuning range was greater than 90 nm for the transmission dynamic range larger than 20 dB. Multiwavelength operation of a single device is achieved by simply applying multifrequency electrical signal. Unwanted intensity modulation of the multiwavelength filter is also investigated
- Published
- 2006
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40. Beam Recombination Characteristics in Array Laser Amplification Using Stimulated Brillouin Scattering Phase Conjugation
- Author
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Hee Su Park, Yun Sup Shin, Hong Jin Kong, Hyogun Kim, Jae Oh Byun, and Jae Yong Lee
- Subjects
Diffraction ,Materials science ,business.industry ,Near and far field ,Laser ,Atomic and Molecular Physics, and Optics ,law.invention ,Optics ,law ,Brillouin scattering ,Piston (optics) ,Laser beam quality ,Phase conjugation ,business ,Beam (structure) - Abstract
Beam recombination characteristics were numerically investigated in array laser amplification using stimulated Brillouin scattering phase conjugation. To clarify the effect of piston errors due to imperfect phase locking, spatial intensity profiles of the beam recombination output were calculated in both the near and the far field on the basis of Rayleigh-Sommerfeld diffraction theory. The analyses indicate that piston errors are seriously detrimental to the quality of a beam recombination output and should be eliminated by a proper phase locking. It is also found that the gap between the beam splitting-combining wedges has a negligible effect.
- Published
- 1997
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41. Narrow-bandwidth all-fiber acoustooptic tunable filter with low polarization-sensitivity
- Author
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Hee Su Park, Byoung Yoon Kim, Myeong Soo Kang, Hyo Sang Kim, and Dong-Il Yeom
- Subjects
Materials science ,business.industry ,Bandwidth (signal processing) ,Cladding (fiber optics) ,Polarization (waves) ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Narrow bandwidth ,Stress field ,Wavelength ,All fiber ,Optics ,Electrical and Electronic Engineering ,Large group ,business - Abstract
We demonstrate a narrow-bandwidth acoustooptic tunable filter with very low polarization-sensitivity using a dispersion-compensating fiber that has a large group index difference between the core and the cladding modes with a specific stress distribution. The 3-dB bandwidth of the filter is 0.8 nm with the interaction length of 10 cm, and the polarization-dependent center-wavelength splitting is 0.04 nm at the wavelength around 1550 nm. The origin of the low polarization-dependence is successfully explained through the analysis on the stress field in the fiber.
- Published
- 2005
- Full Text
- View/download PDF
42. Experimental direct estimation of nonlinear functionals of photonic quantum states via interferometry with a controlled-swap operation
- Author
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Sang Min Lee, Hee Su Park, and Sang-Kyung Choi
- Subjects
Quantum optics ,Physics ,Photons ,Light ,business.industry ,Cavity quantum electrodynamics ,Equipment Design ,Models, Theoretical ,Atomic and Molecular Physics, and Optics ,Equipment Failure Analysis ,Interferometry ,Nonlinear system ,Refractometry ,Optics ,Nonlinear Dynamics ,Quantum state ,Qubit ,Computer-Aided Design ,Quantum Theory ,Scattering, Radiation ,Computer Simulation ,Quantum information ,Photonics ,business - Abstract
We propose a multi-photon interferometer with a generalized C-SWAP operation that can estimate Tr[rho(1)rho(2)center dot center dot center dot rho(n)], a nonlinear functional of n photonic density matrices. The scheme is demonstrated for three single-photon states whose overlap is experimentally measured as the interference visibility of a control qubit encoded into photonic paths. The validity of this method is verified by comparing the visibility with the results of Hong-Ou-Mandel experiments. (C) 2013 Optical Society of America
- Published
- 2013
43. Quantum-enhanced spatial interference with the three-photon N00N state
- Author
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Osung Kwon, Sang Min Lee, Hee Su Park, Yong-Su Kim, Yoon-Ho Kim, Heonoh Kim, Jong-Chan Lee, and Sang-Kyung Choi
- Subjects
Quantum optics ,Physics ,Photon ,business.industry ,Physics::Optics ,State (functional analysis) ,Interference (wave propagation) ,law.invention ,Optics ,law ,Quantum interference ,Reflection coefficient ,business ,Quantum ,Astrophysics::Galaxy Astrophysics ,Beam splitter - Abstract
We report the experimental demonstration of the Young's double-slit type spatial quantum interference of the three-photon N00N state, showing three times denser non-classical spatial interference fringes than that of the single-photon state.
- Published
- 2013
- Full Text
- View/download PDF
44. Tunable Narrow-Bandwidth Optical Filter Based on Acoustically Modulated Fiber Bragg Grating
- Author
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Hee Su Park, Byoung Yoon Kim, and Dong-Il Yeom
- Subjects
Condensed Matter::Quantum Gases ,PHOSFOS ,Materials science ,business.industry ,Physics::Optics ,Grating ,Long-period fiber grating ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Optics ,Fiber Bragg grating ,Fiber optic sensor ,Optoelectronics ,Dispersion-shifted fiber ,Electrical and Electronic Engineering ,business ,Plastic optical fiber ,Photonic-crystal fiber - Abstract
We demonstrate a novel tunable narrow-bandwidth optical filter based on an acoustically modulated fiber Bragg grating (FBG). A flexural acoustic wave applied to an off-centered core FBG modulates the period of the grating, producing sidebands tunable both in wavelength and magnitude.
- Published
- 2004
- Full Text
- View/download PDF
45. Optical frequency-domain reflectometry based on wavelength-swept mode-locked fiber laser
- Author
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Myoung Sook Oh, Byoung Yoon Kim, and Hee Su Park
- Subjects
Distributed feedback laser ,Materials science ,Multi-mode optical fiber ,business.industry ,Polarization-maintaining optical fiber ,Graded-index fiber ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Optics ,Fiber Bragg grating ,Fiber optic sensor ,Fiber laser ,Optoelectronics ,Dispersion-shifted fiber ,Electrical and Electronic Engineering ,business - Abstract
We demonstrate a novel optical frequency-domain reflectometry system with compactness and short measurement time based on the use of a wavelength-swept mode-locked fiber laser. The optical source uses an intracavity tunable Fabry-Perot filter as a tuning element. The fiber laser sweeps 20 nm in less than 10 ms. Spatial resolution of 100 /spl mu/m and total measurement range of several centimeters are demonstrated.
- Published
- 2003
- Full Text
- View/download PDF
46. Measurement of the Entanglement between Photonic Spatial Modes in Optical Fibers
- Author
-
Sang Min Lee, Hee Su Park, Byoung Yoon Kim, Sang-Kyung Choi, Jaekwon Ko, and Yoonshik Kang
- Subjects
Physics ,Bell state ,Photon ,business.industry ,Physics::Optics ,General Physics and Astronomy ,Quantum Physics ,Quantum entanglement ,Quantum tomography ,Optics ,Quantum state ,Photonics ,business ,Quantum information science ,Photonic crystal - Abstract
We experimentally demonstrate the entanglement of spatial modes between two photons propagating through separate few-mode optical fibers. Quantum states over the two lowest-order spatial modes are measured with highly efficient spatial-mode analyzers based on acousto-optics. Quantum state tomography verifies the entanglement of the spatial-domain Bell state.
- Published
- 2012
- Full Text
- View/download PDF
47. Experimental realization of a four-photon seven-qubit graph state for one-way quantum computation
- Author
-
Dong-Hoon Lee, Jae Yong Lee, Heonoh Kim, Sang-Kyung Choi, Yoonshik Kang, Jaeyoon Cho, Sang Min Lee, and Hee Su Park
- Subjects
Photon ,Light ,Computer science ,GeneralLiterature_INTRODUCTORYANDSURVEY ,FOS: Physical sciences ,Quantum entanglement ,Data_CODINGANDINFORMATIONTHEORY ,Topology ,Graph state ,Computer Science::Emerging Technologies ,Scattering, Radiation ,Computer Simulation ,Hardware_ARITHMETICANDLOGICSTRUCTURES ,Quantum computer ,Quantum Physics ,Photons ,business.industry ,Optical Devices ,Signal Processing, Computer-Assisted ,Equipment Design ,Models, Theoretical ,Polarization (waves) ,Atomic and Molecular Physics, and Optics ,Equipment Failure Analysis ,Qubit ,Computer-Aided Design ,Photonics ,business ,Quantum Physics (quant-ph) - Abstract
We propose and demonstrate the scaling up of photonic graph state through path qubit fusion. Two path qubits from separate two-photon four-qubit states are fused to generate a two-dimensional seven-qubit graph state composed of polarization and path qubits. Genuine seven-qubit entanglement is verified by evaluating the witness operator. Six qubits from the graph state are used to execute the general two-qubit Deutsch-Jozsa algorithm with a success probability greater than 90%., Comment: 4 pages. Supplementary Material is included in the zip file
- Published
- 2012
48. Path Qubit Fusion for Photonic Cluster State Generation
- Author
-
Yoonshik Kang, Jaeyoon Cho, Sang Min Lee, Hee Su Park, and Sang-Kyung Choi
- Subjects
Physics ,Quantum optics ,business.industry ,Cluster state ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Quantum Physics ,One-way quantum computer ,Computer Science::Emerging Technologies ,Quantum mechanics ,Qubit ,Photon polarization ,Hardware_ARITHMETICANDLOGICSTRUCTURES ,W state ,Photonics ,business ,Superconducting quantum computing - Abstract
This work describes an experimental fusion operation of photonic path qubits. This new method helps to construct a more complex cluster state composed of single-photon two-qubit states that possess both polarization and path qubits.
- Published
- 2011
- Full Text
- View/download PDF
49. All-fiber add-drop wavelength-division multiplexer based on intermodal coupling
- Author
-
In Kag Hwang, Seok Hyun Yun, Hee Su Park, Byoung Yoon Kim, and Sang Bae Lee
- Subjects
Materials science ,business.industry ,Physics::Optics ,Communications system ,Multiplexer ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Wavelength ,Optics ,All fiber ,Fiber Bragg grating ,Wavelength-division multiplexing ,Drop (telecommunication) ,Electrical and Electronic Engineering ,business ,Optical add-drop multiplexer ,Computer Science::Information Theory - Abstract
We demonstrate a novel all-fiber add-drop multiplexer by using a tilted Bragg grating written on a two-mode fiber and a mode-selective coupler. The device can be made potentially with low loss and low cost, useful for add-drop of a small number of channels in wavelength-division-multiplexing (WDM) communication systems.
- Published
- 2001
- Full Text
- View/download PDF
50. Observation of Young's Double-Slit Interference with the Three-Photon N00N State
- Author
-
Yong-Su Kim, Osung Kwon, Sang Min Lee, Jong-Chan Lee, Heonoh Kim, Sang-Kyung Choi, Hee Su Park, and Yoon-Ho Kim
- Subjects
Photon ,Light ,Physics::Optics ,FOS: Physical sciences ,Quantum entanglement ,Interference (wave propagation) ,Optics ,Quantum mechanics ,Scattering, Radiation ,Computer Simulation ,Reflection coefficient ,Lithography ,Quantum ,Quantum computer ,Quantum optics ,Physics ,Quantum Physics ,Photons ,business.industry ,Visibility (geometry) ,State (functional analysis) ,Models, Theoretical ,Atomic and Molecular Physics, and Optics ,Refractometry ,Quantum Theory ,Double-slit experiment ,Photonics ,business ,Quantum Physics (quant-ph) - Abstract
Spatial interference of quantum mechanical particles exhibits a fundamental feature of quantum mechanics. A two-mode entangled state of N particles known as N00N state can give rise to non-classical interference. We report the first experimental observation of a three-photon N00N state exhibiting Young's double-slit type spatial quantum interference. Compared to a single-photon state, the three-photon entangled state generates interference fringes that are three times denser. Moreover, its interference visibility of $0.49 \pm 0.09$ is well above the limit of 0.1 for spatial super-resolution of classical origin. The demonstration of spatial quantum interference by a N00N state composed of more than two photons represents an important step towards applying quantum entanglement to technologies such as lithography and imaging.
- Published
- 2010
- Full Text
- View/download PDF
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