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This article proposes a triple-mode isolated resonant buck–boost converter over a wide input voltage range for residential applications of photovoltaic arrays and fuel cells. First, in case that the input voltage is smaller than the nominal voltage, it operates in a resonant-boost mode that boosts the input voltage by using a bridgeless structure on the secondary-side. Next, if the input voltage is within the range of the nominal voltage, it operates in a fully series-resonant mode, which results in high efficiency by the soft-switching on the primary-side switches and reduced conduction loss. Last, if the input voltage is more than the nominal voltage, it operates in a pulsewidth modulation series-resonant buck mode, which can achieve the step-down conversion by reducing the duty cycle. Unlike the conventional resonant converters, the proposed converter achieves high efficiency and less number of power components over a wide input voltage range. Finally, the performance of the proposed triple-mode isolated resonant converter has been fully verified on a prototype 400 W test-bed in the wide input voltage of 35–65 V.

Cortical connectivity analysis is a widely used method for understanding the causes of neurological disorders and related brain mechanisms. Although there exist numerous activity analysis toolboxes for functional near-infrared spectroscopy (fNIRS), there are only a few cortical connectivity analysis toolboxes. In 2019, we released a MATALB toolbox named OptoNet , which has helped researchers to analyze brain networks using fNIRS. In this study, we developed an advanced MATLAB toolbox, named OptoNet II, to add new features that overcome the shortcomings of OptoNet . With these new features, OptoNet II can efficiently analyze cortical connectivity according to brain region using any fNIRS channel sets and can present the results of two connectivity analyses with auto-thresholding based on surrogate tests. To evaluate the efficacy of the new functions, the finger-tapping task experiment was carried out before and after transcranial direct current stimulation (tDCS) in the primary motor area. OptoNet II can efficiently show the effects of tDCS on functional brain region connectivity, which has been difficult to confirm by conventional methods. In this article, we propose the OptoNet II as a useful and efficient toolbox for researchers who want to perform cortical connectivity analysis using fNIRS.

Recently, efforts have been made to adapt surface acoustic waves (SAWs) for use in chemical sensors for detection of chemical warfare agents (CWAs). In this study, a four-channel real-time CWA detection system was constructed using four 250-MHz SAW sensors. Each system consists of three different chemical sensors and one reference sensor. The reference sensor compensates for frequency variations according to humidity and temperature conditions. Signals from the SAW sensors can be checked on a PC-based graphical user interface without additional measuring equipment. To measure dimethyl methylphosphonate (DMMP), a simulant of sarin gas, polyhedral oligomeric silsesquioxane (POSS) and thiourea (TU)-based synthetic polymers were used as sensing materials. The reference sensor was not coated, whereas the three different chemical sensors were coated with POSS, TU-1, and TU-2. The maximum frequencies of POSS, TU-1, and TU-2 were shifted 15.86, 13.85, and 0.944 kHz, showing significant values. We also found a relatively good linear relation between the frequency shift and the concentration of DMMP. The three sensing materials selected-POSS, TU-1, and TU-2-responded significantly to DMMP and triethylphosphate in the selectivity tests. This response is due to the chemical bonding of the sensing materials with the phosphonate in the nerve-agent simulants. These results indicate that the four-channel SAW monitoring system described in this paper shows potential as a portable real-time monitoring system to detect a variety of toxic vapors simultaneously, without using complex measuring equipment. In addition, this approach has demonstrated potential for developing excellent portable sensors to detect different types of CWAs.

The effects of a plasma treatment on the sensing performance of surface acoustic wave (SAW) sensors to detect chemical warfare agents (CWAs) were investigated. SAW sensors designed for an operating frequency of 250 MHz were fabricated using lift-off techniques followed by the deposition of a very thin thiourea (TU) layer as a sensing film on the sensing area of the SAW sensor. To achieve some advantages from the plasma treatment on the surface, such as cleaning, surface activation and modification, a post-plasma treatment was performed on the sensing layer and the sensing performance of the SAW sensor was measured by a comparison with the measured responses, providing different simulant gases through the gas feeding system. The sensitivity test revealed significant improvement in the sensing ability of the SAW sensor to detect DMMP, a simulant of a CWA, but with a relatively longer recovery time. The responses of other simulants at different concentrations and different simulant vapors were compared. The results showed that a plasma treatment on the sensing layer of a SAW device can improve the selectivity and sensitivity to a certain target gas or some volatile organic compounds. Therefore, a plasma treatment will be very useful for improving the selectivity and sensitivity of SAW sensors for the detection of CWAs.

Background: Recently, the kinesiology taping (KT) method was reported to be effective in improving walking ability in foot drop patients after stroke, but the clinical basis is still unclear. Objectives: The KT method was compared with ankle-foot orthotics (AFO) to investigate gait ability in foot drop patients after stroke. Design: Crossover study design. Methods: In this study, 11 stroke patients with foot drop participated. Walking ability of all subjects for both conditions (KT and AFO) was measured using the GAITRite system. The order of application of the two conditions was determined randomly by drawing lots. Wilcoxon signed-rank test was used to compare walking ability between the two conditions. The level of statistical significance was set at P< .05. Results: There were no significant differences between the KT and AFO methods in terms of velocity, cadence, step length, and stride length (P >.05, all). Conclusion: This study recommends KT as an alternative to the AFO, since KT provides evidence of preventing of foot drops and improving gait ability in stroke patient.

The modern automobile industry is rapidly shifting toward the era of self-driving cars. Due to rapid technological development, many mechanical parts in automobiles have been switched to electronic devices. Therefore, the proportion of electronic devices in modern cars is increasing. Even though many parts have been replaced by electronic devices, vehicles still require the periodic maintenance not only for mechanical parts, but also for automotive electronics. To guarantee the high reliability of automotive Application-Specific Integrated Circuits (ASICs), automotive chips are tested during manufacturing for functional and structural defects. Moreover, automobile chips are also tested using several in-field diagnostic techniques (e.g., online Built-In Self-Test (BIST), Software-Based Self-Test (SBST)) while the chips are operating. By using these in-field diagnostic techniques, functional and structural defects in automotive ASICs, which occur in the early-life cycle and normal operation, can be detected. However, automotive semiconductor devices still require testing for aging-induced defects and soft errors to prevent critical functional failures. Moreover, aging-induced defects are hard to detect with conventional in-field diagnostic techniques which is based on BIST techniques. Thus, this work presents a secure Controller Area Network (CAN) -based Test Access Mechanism (TAM) for aging defect diagnosis with efficient soft-error resilient scan cell design for automotive ASICs. The proposed TAM incurs area overhead of 6% to 9% depending upon the selection of mode identification. Further, the proposed Aging monitoring and Soft Error Resilience Flip Flop (ARFF) incurs 22% less area and power as compared to separate implementation of the Built-In Soft Error Resilience (BISER) and the Early Capture Flip Flop (ECFF).

In the elderly, walking while simultaneously engaging in other activities becomes more difficult. This study aimed to examine the changes in cortical activity during walking with aging. We try to reveal the effects of an additional task and increased walking speed on cortical activation in the young-old and the old-old elderly. Twenty-seven young-old (70.2 ± 3.0 years) and 23 old-old (78.0 ± 2.3 years) participated in this study. Each subject completed four walking tasks on the treadmill, a 2 × 2 design; two single-task (ST) walking conditions with self-selected walking speed (SSWS) and fast walking speed (FWS), and two dual-task (DT) walking conditions with SSWS and FWS. Functional near-infrared spectroscopy was applied for measurement of cerebral oxyhemoglobin (oxyHb) concentration during walking. Cortical activities were increased during DT conditions compared with ST conditions but decreased during the FWS compared with the SSWS on the primary leg motor cortex, supplementary motor area, and dorsolateral prefrontal cortex in both the young-old and the old-old. These oxyHb concentration changes were significantly less prominent in the old-old than in the young-old. This study demonstrated that changes in cortical activity during dual-task walking are lower in the old-old than in the young-old, reflecting the reduced adaptive plasticity with severe aging.

The Radiation Therapy Oncology Group (RTOG) 9310 protocol clinical trial established high-dose methotrexate (HDMTX) as the standard for primary central nervous system lymphoma (PCNSL). We aimed to investigate the RTOG 9310 protocol’s PCNSL outcomes by examining progression-free survival (PFS) and overall survival (OS) rates and determining the influential factors. Between 2007 and 2020, 87 patients were histopathologically diagnosed with PCNSL and treated with the RTOG 9310 protocol. All received HDMTX 2.5 g/m2 and vincristine 1.4 mg/m2/day for 1 day during weeks 1, 3, 5, 7, and 9, and procarbazine 100 mg/m2/day for 1 day during weeks 1, 5, and 9. Dexamethasone was administered on a standard tapering schedule from the first week to the sixth week. Whole brain radiotherapy (WBRT), consisting of 45 Gy for patients with less than a complete response to the chemotherapy or 36 Gy for complete responders, was started 1 week after the last dose of chemotherapy was administered. Within three weeks of the completion of WBRT, patients received two courses of cytarabine, which were separated by 3–4 weeks. Clinical, radiological, and histopathological characteristics were retrospectively reviewed. All patients completed five HDMTX cycles and a mean follow-up of 60.2 (range, 6–150) months. Twenty-eight (32.2%) patients experienced recurrence during follow-up. The mean time to recurrence was 21.8 months, while the mean PFS was 104.3 (95% confidence interval (CI), 90.6–118.0) months. Eleven (12.6%) patients died, the mean OS was 132.1 (95% CI, 122.2–141.9) months. The 3- and 5-year survival rates were 92.0% and 87.4%, respectively. One patient experienced acute renal failure, while the remainder tolerated any cytotoxic side effects. On multivariate analysis, the Eastern Cooperative Oncology Group performance score ≤ 2, the International Extranodal Lymphoma Study Group low-risk status, XBP-1, p53, and c-Myc negativity, homogenous enhancement, gross total resection, independently correlated with long PFS and OS. The RTOG 9310 protocol is effective for PCNSL and features good outcomes.

The effect of the swirl clocking on three-dimensional nozzle guide vane (NGV) is investigated using computational fluid dynamics. The research reports the loss characteristics of leaned and swept NGVs and the influence of swirl clocking. The three-dimensional NGVs are built by stacking the same 2D profile along different linear axes, characterized by different angles with respect to the normal or radial direction: ε = −12° ~ +12° for the leaned and γ = −5° ~ +10° for the swept airfoils. A total of 40 models are analyzed to study the effects of lean and sweep on aerodynamic performance. To investigate the influence of swirl clocking, the analysis cases include the center of the swirl that was positioned at the leading edge as well as the middle of the passage. The prediction results show that the relationship of the changes in mass flow rate and throat area are not monotonic. Further observation confirms the redistribution of loading and flow angle under different lean and sweep angles, thus, three-dimensional design is a key influencing factor on aerodynamic performance. In the presence of swirl clocking, NGV performance is changed significantly and the findings offer new insight and opportunities to improve three-dimensional NGV airfoil design.

This paper presents a hybrid dual-path Buck-Boost DC-DC converter (DPBB) achieving high power efficiency for the entire input voltage (V IN ) range (2.8 to 4.2V) from a Li-ion battery for mobile applications. Unlike conventional noninverting buck-boost converters (CBB), the proposed DPBB supplies a load current (I LOAD ) at all phases by using the inductor path (L-path) and capacitor path (C-path) alternately. As a result, our design achieves high efficiency by reducing conduction losses and suppresses the output voltage (V OUT ) ripple. It has only a single control mode over the whole V IN range, unlike the previous designs that require complex mode transitions. Note that high efficiency is achieved not only across a wide I LOAD range but also over a wide V IN range. The proposed DPBB achieves 96.6% peak efficiency with the smallest difference between the maximum and minimum efficiencies over a given range of I LOAD and V IN .

The objective of this study was to evaluate whether Cerebrolysin combined with rehabilitation therapy supports additional motor recovery in stroke patients with severe motor impairment. This study analyzed the combined data from the two phase IV prospective, multicenter, randomized, double-blind, placebo-controlled trials. Stroke patients were included within seven days after stroke onset and were randomized to receive a 21-day treatment course of either Cerebrolysin or placebo with standardized rehabilitation therapy. Assessments were performed at baseline, immediately after the treatment course, and 90 days after stroke onset. The plasticity of the motor system was assessed by diffusion tensor imaging and resting state fMRI. In total, 110 stroke patients were included for the full analysis set (Cerebrolysin n = 59, placebo n = 51). Both groups showed significant motor recovery over time. Repeated-measures analysis of varianceshowed a significant interaction between time and type of intervention as measured by the Fugl–Meyer Assessment (p &lt, 0.05). The Cerebrolysin group demonstrated less degenerative changes in the major motor-related white matter tracts over time than the placebo group. In conclusion, Cerebrolysin treatment as an add-on to a rehabilitation program is a promising pharmacologic approach that is worth considering in order to enhance motor recovery in ischemic stroke patients with severe motor impairment.

Chemical Warfare Agents (CWAs), powerful chemical weapons in warfare and armed conflict, were prohibited by the Organization for the Prohibition of Chemical Weapons (OPCW), but the danger persists because of its misuse in terrorism and warfare. It is crucial to detect them rapidly because exposure to small quantity of CWAs can cause lethal damage or death in a short time. Generally, they have been detected by various conventional techniques such as photoionization, ion mobility spectroscopy, flame photometry, and IR spectroscopy. But most of these methods possess a crucial challenge in being a portable detector because they are heavy, bulky, and consumes large power. In this study, the surface acoustic wave (SAW) sensor, quartz crystal microbalance (QCM) sensor, and quantum cascade lasers (QCL) were used to detect simulant of CWA. The SAW sensor and QCM sensor, a chemical detector based on piezoelectric substrates, detect chemical compounds using mass loading effect. It is caused by the adsorption of chemical compounds on the sensing material coated on the surface of the delay line. Therefore, the synthesis method, coating process, type, and concentration of sensing material have a prime effect on the sensitivity of the sensor. QCL was used to make a contactless small chemical detector with a mid-infrared photodetector, drive circuit, and optical hardware. Most CWAs have very high absorption rates and different absorption spectra in the range of 8-12 μm wavelengths. This detection method provides real-time detection of CWAs based on advantages of being contactless, excellent selectivity, and high sensitivity.

Background: Low-frequency rTMS can induce upregulation of excitability in the contralateral hemisphere by interhemispheric interaction. Objective: The aim of this study was to compare the effects of interhemispheric modulation on hemodynamic changes after applying low-frequency rTMS over the anatomical hand knob (HK) and the hand motor hotspot (hMHS) in the dominant motor cortex. Methods: Ten healthy right-handed participants without a history of neurological or psychiatric symptoms (five males; 29.8±2.8 years) participated in this single-blind, randomized, cross-over study. rTMS was applied under three conditions over the dominant (left) hemisphere for 20 minutes: 1) 1 Hz rTMS stimulation on the HK (HK-rTMS), 2) 1 Hz rTMS stimulation on the hMHS (hMHS-rTMS), and 3) sham stimulation (Sham-rTMS). For all participants, functional near-infrared spectroscopy (fNIRS) was applied for measurement of cerebral oxyhemoglobin (oxyHb) and deoxyhemoglobin (deoxyHb) concentration over the non-dominant (right) hemisphere during a serial reaction time task (SRTT) with the non-dominant (left) hand before and after each condition. Results: The average coordinates of the hMHS (x = – 39.60 mm, y = – 17.11 mm, z = 66.40 mm) were anterior and lateral to the HK (x = – 36.72 mm, y = – 28.87 mm, z = 56.41 mm). In fNIRS time-series analysis, the integral value of oxyHb was significantly increased over the motor cortical region of the non-dominant hemisphere after the hMHS-rTMS compared with Sham-rTMS. The HK-rTMS also showed slight increment of oxyHb concentration but without statistical significance. The SPM group analysis showed greater magnitude of the activity in hMHS-rTMS than that of HK-rTMS after stimulation (p

We report a schlieren-style stroboscopic phase-contrast field-amplitude imaging of two-dimensional acoustic whispering gallery modes in a circular shell cavity immersed in liquid. A schlieren signal is combined with a presplit reference beam to enable nonscan field-amplitude imaging. Excitation mechanisms of standing and traveling eigenmodes, respectively, are analyzed with acoustic ray simulations presented in a Poincaré surface of sections. The time evolutions for both standing and traveling eigenmodes are reconstructed using the stroboscopic capability.

Background and purpose Various clinical and neuroimaging predictive factors have been identified for the recovery of upper extremity (UE) motor function after stroke. However, few studies have addressed factors related to the recovery of lower extremity (LE) motor function after stroke or performed direct comparisons of UE and LE motor recovery in the same set of patients. In this study, predictive factors for UE and LE motor recovery after stroke were investigated using clinical and neuroimaging characteristics. Methods Forty-two subacute ischaemic stroke patients underwent structural and functional magnetic resonance imaging data acquisition and cognitive/behavioral assessments using the Fugl-Meyer assessment, the National Institutes of Health Stroke Scale (NIHSS) and the Mini-Mental State Examination (MMSE) 2 weeks after stroke onset. Neuroimaging factors, including corticospinal tract (CST) fractional anisotropy, lesion volume, CST lesion load and interhemispheric homotopic functional connectivity, were extracted. The outcome of motor function was assessed by Fugl-Meyer assessment scores 3 months after onset. Results Early clinical and neuroimaging factors for predicting motor recovery were noticeably different for UE and LE. UE motor function recovery was related to age, NIHSS, MMSE, CST lesion load, lesion volume, ipsilesional CST integrity and interhemispheric homotopic functional connectivity. In contrast, LE motor recovery was related to ipsilesional and contralesional CST integrity and MMSE. Specifically, LE recovery showed a strong relationship to the preservation of cognitive function compared with motor impairment. Conclusions Our results indicate that different mechanisms underlie UE and LE motor recovery after stroke. LE motor recovery seems to be more intensively modulated by cognitive functions than UE.

Repetitive transcranial magnetic stimulation (rTMS) is used to modulate neuronal excitability of the human brain. Distant effects on contralateral corticomotor excitability can be exerted by interhemispheric modulation by low-frequency rTMS on ipsilateral hemisphere. To modulate corticospinal excitability, accurate determination of the stimulation site is important to maximize the effects of rTMS. In the present study, we investigated the difference in the distant effect of 1 Hz rTMS with respect to inducing functional improvement in the non-dominant hand by inhibiting the dominant hemisphere depending on cortical target areas. Ten healthy right-handed volunteers without any neurological disorders were enrolled. The anatomical hand knob (HK) identified from individual magnetic resonance imaging and the transcranial magnetic stimulation (TMS) induced hand motor hotspot (hMHS) by recording motor evoked potentials (MEPs) in the contralateral first dorsal interosseous muscle were determined. All participants underwent three conditions of 1 Hz rTMS on left hemisphere intervention; rTMS application over the HK, rTMS application over the hMHS, and sham-rTMS. Before and after each intervention, all participants undergone motor function assessments with their left hand. The cortical mapping showed that the hMHS was located anteriorly and laterally compared to the HK. Motor function tests showed the most significant improvements after the hMHS stimulation. When we compared the distant effects of target site on corticospinal excitability and motor behavior, delivering 1 Hz rTMS to the hMHS was more effective than delivering it to the HK for improving corticomotor excitability, motor skill, and dexterity. These results suggest that TMS-induced hMHS is an optimal target area to induce distant effect of low-frequency rTMS in motor function.

Background Surgery is the most important treatment modality for papillary thyroid cancer (PTC). However, the relationship between surgeon volume and long-term oncological outcomes has not been explored. Methods Patients diagnosed with N1b PTC after initial thyroid surgery between 1 July 1994 and 31 December 2011 were eligible for inclusion in the study. Surgeons were categorized into high (at least 100 operations per year) and low (fewer than 100 operations per year) volume groups. Kaplan–Meier survival analysis according to surgeon volume was performed, and Cox proportional hazard modelling was used to estimate hazard ratios (HRs) with 95 per cent confidence intervals according to patient, tumour and surgeon factors. Results A total of 1103 patients with a median follow-up of 81 (i.q.r. 62–108) months were included in the study. During follow-up, 200 patients (18·1 per cent) developed structural recurrence. A high surgeon volume was associated with low structural recurrence (P = 0·006). After adjustment for age, sex and conventional risk factors for recurrence (histology, tumour size, gross extrathyroidal extension, margin status, more than 5 positive lymph nodes, radioactive iodine therapy), the adjusted HR for structural recurrence for low-volume surgeons was 1·46 (95 per cent c.i. 1·08 to 1·96), compared with high-volume surgeons. Distant metastasis (P = 0·242) and disease-specific mortality (P = 0·288) were not affected by surgeon volume. Conclusion Surgeon volume is associated with structural recurrence, but not distant metastasis or cancer-specific death in patients with N1b PTC. Surgeon volume is important in initial surgery for advanced PTC with extensive nodal metastasis in order to ensure curative outcome and reduce treatment-related morbidity.

This paper proposes a fuzzy model predictive direct torque control (FMP-DTC) strategy of interior permanent magnet synchronous motors (IPMSMs) for electric vehicle (EV) applications. The fuzzy logic control technique incorporated into the proposed FMP-DTC scheme dynamically determines the appropriate values of the weighting factors, and then generates the optimal switching states that minimize the electromagnetic torque and stator flux errors. Unlike the conventional model predictive (MP)-DTC strategy, the optimal switching states of the proposed FMP-DTC are selected without retuning the weighting factors. It means that they are updated depending on the specific operating conditions. Therefore, the proposed FMP-DTC is effective in various operating conditions that make it suitable for the EV-traction operating environment. Hence, the proposed FMP-DTC method has a simple control structure and can explicitly handle the system constraints. The performance evaluation is carried out via both MATLAB/Simulink and a prototype IPMSM test-bed with a TMS320F28335 digital signal processor (DSP). Comparative simulation and experimental results present the evidence of the performance improvements based on the proposed FMP-DTC strategy compared with the conventional MP-DTC strategy by indicating a fast transient torque response, low ripples, and an accurate speed tracking even under rapid climbing or emergency braking situations.

This paper proposes an online identification method that can accurately estimate the stator resistance and dq -axis stator inductances for the effective model-based sensorless control of interior permanent magnet synchronous motors (IPMSMs). The proposed affine projection algorithms are uniquely designed in the estimated rotating γ-δ frame to precisely identify the parameters mentioned above. The two time-scale approaches are employed in the affine projection algorithms to estimate the three electrical parameters. Despite the electrical parameter variations due to the temperature change and magnetic saturation during operation, the rich enough data are provided to the affine projection algorithms in the discrete-time domain to accurately retrieve the updated parameters. These correctly estimated parameters are adapted to the extended back electromotive force observer for the sensorless control of IPMSM drives. Hence, the adaptation of online updated parameters makes the observer stable and robust to parameter variations as compared to the conventional observer without updated parameters. The MATLAB/Simulink-based simulation results and experimental results via a prototype IPMSM test-bed having TMS320F28335 DSP are given to verify the accurate convergence of the estimated parameters, which results into a stable sensorless control system under various operating conditions.

Objective: The purpose of this study was to apply a general linear model in statistics to marker position vectors used to study human joint rotational motion in biomechanics. Method: For this purpose, a linear model that represents the effect of the center of hip joint rotation and the rotation of the marker position on the response was formulated. Five male subjects performed hip joint functional motions, and the positions of nine markers attached on the thigh with respect to the pelvic coordinate system were acquired at the same time. With the nine marker positions, the center of hip joint rotation and marker positions on the thigh were estimated as parameters in the general linear model. Results: After examining the fitted model, this model did not fit the data appropriately. Conclusion: A refined model is required to take into account specific characteristics of longitudinal data and other covariates such as soft tissue artefacts.

Background The patterns, predictive factors and prognostic impact of multilevel metastasis in patients with N1b papillary thyroid carcinoma (PTC) were investigated. Methods A retrospective review of patients with N1b PTC from a tertiary referral centre in Korea who underwent unilateral modified radical neck dissection was undertaken. Results Of 658 patients, multilevel metastasis was found in 73·9 per cent; the most common type was metastasis in two levels. Tumour size per 0·1-cm increment (adjusted odds ratio (OR) 1·33, 95 per cent c.i. 1·08 to 1·64), microscopic extrathyroidal extension (adjusted OR 1·72, 1·10 to 2·71), gross extrathyroidal extension (adjusted OR 2·35, 1·24 to 4·46), unilateral central lymph node metastasis (adjusted OR 2·45, 1·53 to 3·92) and bilateral central lymph node metastasis (adjusted OR 4·06, 2·29 to 7·18) were independent predictors of multilevel metastasis. Only four-level metastasis significantly increased the risk of overall locoregional recurrence (LRR) (adjusted hazard ratio (HR) 7·41, 95 per cent c.i. 2·20 to 24·53) and lateral neck LRR (adjusted HR 7·22, 1·82 to 28·65), compared with one-level metastasis. Two subgroup analyses were conducted, showing that only three-level metastasis including metastasis in level V significantly increased the risk of overall LRR (adjusted HR 5·66, 1·20 to 26·75). In addition, having level V metastasis was an independent predictor of both overall (adjusted HR 3·26, 1·72 to 6·18; P < 0·001) and lateral neck (adjusted HR 3·28, 1·50 to 7·16; P = 0·003) LRR. Conclusion Level V metastasis rather than multilevel metastasis itself is associated with an increased risk of LRR. Patients with N1b PTC and level V metastasis require risk restratification and meticulous follow-up.

The current study proposes a new pre-swirler configuration with a splitter for gas turbines. The pre-swirl vane with low aspect ratio results in strong secondary flows and high endwall loss. The splitter concept is demonstrated to reduce aerodynamic loss and improve swirl ratio. The discharge coefficient and swirl ratio increase after the distance between the vane and the splitter is adjusted. Numerical simulations are conducted to validate the performance of the pre-swirler with a splitter. The total pressure loss at the exit of the pre-swirler is reduced by 14 % to 17 % when the splitter is installed. The exit yaw angle increases when the space between the upper vane and the splitter is reduced. Consequently, the increased exit yaw angle increases the tangential velocity at the exit of the pre-swirler and the swirl ratio of the pre-swirl system. A vane-type pre-swirler with splitter is recommended to improve the performance of the pre-swirl system.

The demand to ensure the safety, reliability and comfort in automobiles has increased the complexity of in-vehicle electronic systems. Like mechanical maintenance, regular monitoring of the health of semiconductor chips is also important. This paper presents a framework for a low abstraction level maintenance of semiconductor chips of the vehicular network nodes through FlexRay network, while complying with the FlexRay protocol. The proposed framework is demonstrated with the scan-test data transportation.

In the present work, design optimization of film-cooling hole array on the pressure side of high pressure turbine nozzle was conducted. There are four rows of fan-shaped film cooling holes on the nozzle pressure side surface and each row has a straight array of holes in the spanwise direction for baseline model. For design optimization, hole distributions in streamwise and spanwise directions for three rows of holes except first row are parameterized as a 2nd-order shape function. Three-dimensional compressible RANS equations are used for flow and thermal analysis around the nozzle surface and optimization technique using Design of Experiment, Kriging surrogate model and Genetic Algorithm is used . The results shows that averaged adiabatic wall temperature at the whole nozzle surface decreases about 2.7% and averaged film cooling effectiveness at the pressure side of nozzle increased about 8.2%. 1. 서 론 가스터빈 엔진의 성능 및 효율의 향상과 함께 터빈 입구온도(Turbine Inlet Temperature, TIT)는 지속적으로 증가되어왔다. 이 때문에 고온 고압의 유동조건을 견디기 위한 재료 및 냉각기법에 대한 많은 연구가 수행되었다.막냉각(Film-cooling)기법은 냉각공기를 물체 표면으로 분사시켜 냉각기체에 의한 막을 형성함으로서 금속표면을 보호하는 외부냉각 기법이다. 막냉각 성능에는 분사각, 홀 사이의 간격, 홀의 형상과 같은 분사형상과 분사비, 밀도비, 난류강도 등의 유동조건이 영향을 미친다. 따라서 다양한 분사형상 및 분사조건에 대한 연구를 통한 막냉각 홀의 냉각성능 향상 시도가 있어왔으며 그 결과 다양한 형상의 막냉각 홀이 제시되었다.

The workspace, working velocity, excavating force, and load capacity of a hydraulic excavator play critical roles in the performance of the excavator for various tasks. This paper presents an optimal design of the front linkage of an excavator to maximize the performances of several indices simultaneously. A multi-objective function is defined to increase the excavator’s workspace, working velocity, excavating force, and load capacity simultaneously. The workspace is defined by using four geometrical indices and the working velocity is defined by the amount of time needed to perform one cycle composed of digging and dumping. The excavating force consists of two forces, and the load capacity is defined by using the minimum values of three types with specific operations. A total of 10 indices define objective function with each weight, and pin-points of the front linkage are the design parameters, including joint positions of links and hydraulic actuators. A two-step optimization procedure is considered based on a new method called the hybrid Taguchi-random coordinate search algorithm. The results indicate a 3.43% increase in performance relative to the initial design parameters of a commercial excavator. More specifically, the excavator’s workspace, working velocity, excavating force, and load capacity increase by 5.55%, 0.14%, 5.46%, and 0.33%, respectively. These improved design parameters can be applied to next generation excavators.

In this study, a numerical analysis methodology is studied to predict thermal and flow characteristics of C3X vane with internal cooling. Effects of turbulence models, transition models and viscous work term on temperature and pressure distributions on the vane surface are investigated. These optional terms have few effects on the pressure distributions over the vane surface. However, they have great influence on prediction of the temperature distributions on the vane surface. The combination of k-ω based SST turbulence model, γ transition model and viscous work term are better than RSM turbulence model on prediction of the surface temperature. The average temperature difference between CFD results and experimental results is calculated 2 % at the pressure side and 1 % at the suction side. Furthermore computing time of this combination is half of the RSM turbulence model. When k-ω based SST turbulence model and γ transition model with viscous work term are applied, more accurate predictions of thermal and internal flow characteristics of high pressure turbine are expected.

Modern automobiles house many ECUs (Electronic Control Units), which are connected through VCNs (Vehicle Control Networks). Typically, integrated circuits are tested for structural defects, which could occur during fabrication. In general, vehicular ECUs are tested for functional operation. However, due to vibrations, high temperature, etc., defects might be developed in ICs. This work presents a test access mechanism for in-vehicle ICs based on VCNs. The proposed test access mechanism complies with protocols of VCNs and allows the access to the on-chip circuitry.

This study extracts a sign language primitive (SLP) for sign recognition using surface electromyography (sEMG) sensor and a motion sensor. Considering the characteristics of gesture communication, the proposed SLP is composed of hand-shape vector and motion direction vector. 12 representative hand-shape primitives are recognized as hand-shape vector by sum of eight-channel muscle tension at brachial 6 hand-movement primitives are classified as motion direction vector by using the Euler angle differences. Sign language word is recognized by the combination of the extracted SLP. We confirm that the proposed primitive would classify the sign word in 5 different sentences.

Secondary loss of low aspect ratio turbines takes as much as 50% of the total loss. Non-axisymmetric endwall profile optimization was conducted for the nozzle hub and shroud of a 1-stage high-pressure transonic turbine. The endwalls of the hub and the shroud were individually optimized using an approximation model. Kriging model was used for response surface generation and the optimum solution was searched using Genetic Algorithm with stage efficiency as the objective function. Optimized endwall profiles reduced nozzle losses and shocks, thereby improving stage efficiency. The shroud endwall profile showed higher performance, because it influenced the flow over the whole span, whereas the influence of the hub endwall profile was limited close to the hub. The stage efficiency was improved by 0.39%p when both the hub and the shroud endwall profiles were applied. However, the mass flow rate exceeded the design limit and the efficiency had no benefit to the single shroud endwall profile, showing the limitations of individually optimized endwall profiles.

Recently, Building Information Modeling (BIM) has emerged as a hot topic in the construction industry. However, the application of civil engineering, both domestic and foreign, is minor because of the distribution in a wide area, highly liner dependence and difficulty to take advantage of the standard library. Civil engineering requires a lot of time and financial resources compared to architectural engineering. If BIM is completely applied to civil engineering, it will be possible to manage the schedule and cost using 3D and facilitates effective communication between various stakeholders. For the application of BIM in civil engineering, we surveyed the awareness, utilization and effectiveness of BIM on the civil engineering companies. Also, we derived necessary improvements and analyzed new business areas for BIM application. The results of the study will be used as a reference of development for SOC civil engineering BIM ordering guide and related standard.

Introduction/Background Low-level light therapy (LLLT) is used to stimulate cell function or reduce pain by applying light emitting diodes (LED) to the skin. LLLT is known to contribute to the neuronal recovery during the reconstruction of brain tissue for the treatment of degenerative disorders. This research aims to confirm the slow oscillations of cerebral hemodynamics changes when LLLT is applied to the elderly and patients with mild cognitive impairment (MCI). Material and method Eight patients with MCI and 7 healthy elderly participated in this study. They were randomly divided into four groups; carotid artery stimulation, vertebral artery stimulation, simultaneous carotid and vertebral artery stimulation, or sham stimulation. The subjects received LLLT using Color DNA® (Color Seven Co.) with a LED light source for 30 minutes a day during 20 days. The hemodynamic responses were recorded by an fNIRS system (NIRScout®) with 74 channels at the first and the 20th intervention days, before, during, and after the LLLT. The spectral power density over the very low-frequency oscillations (VLFO) of cerebral hemodynamics was calculated using Welch technique. Results In both healthy and MCI patients, VLFO increased in the whole cerebral area during LLLT compared to the resting state, and these changes are more contrasting in the condition with simultaneous carotid and vertebral artery stimulation condition. These characteristics were observed in both the first and 20th intervention days however, VLFO in the 20th intervention day were more increased than the first day. Conclusion Increase of very low frequency oscillations demonstrated increasing spontaneous activity of cerebrovascular tone and neuronal activation. These findings may suggest a possibility of modulating effect of LLLT on neuronal activity and blood vessel reconstruction.

In this paper, we introduce a new tangible interface that allows someone to hit any parts of a medium such as a wooden block in order to generate original multimedia content. We investigate a new technique to estimate precisely the location in which the interaction occurs using two microphones, Arduino and an amplifier. With this setup, and functions that we describe, we can obtain the time spent from the sound of the hit between the user and the medium, to reach each microphone. These travelling times and the knowledge of the material used as medium are then used to precisely locate the origin of the hit. In the last part of this paper, we show an example of use of our system. We use everyday objects and augment them to provide new unexpected experiences when they are touch by someone. We firmly believe the input technique can be used more generally in many different contexts.

In this paper, instead of the input device that is limited to two-dimensional interfaces, we propose input device which is suitable for the virtual display and three-dimensional interfaces. We suggest the wearable device which is capable of 4-DOF continuous intensity input by using the signal extracted through the AHRS and the EMG electrode attached to the hand. By using this device, it is possible not only to represent the movement of the user’s arm but also to reflect the intensity of holding the fist using the magnitude of the EMG. This interface is designed as a universal interface applicable to various displays, and in order to be applied to different locations and to be used in the same way, a wearable-type was selected. In this paper, we present the structure, shape and implementation of the interface and we evaluated the applicability of the device through experiments and simple applications based on MATLAB. Input devices proposed in this paper, was confirmed superior in ease of use and the position control performance when it is compared to the existing pointing input device. There is significance in utilizing as an input device, not only the interface of two-dimension, but the interface with ultra-large display such as a three-dimensional interface.

Flexible parts can be deformed by contact force during assembly. For successful assembly, information about their deformation as well as possible misalignment between mating parts is essential. However, because of the nonlinear and complex relationship between parts deformation and reaction forces, it is difficult to acquire all required information from the reaction forces alone. In this paper, we propose an algorithm that can measure parts deformation and misalignment by using a visual sensing system in flexible parts assembly. Simulation results show that the system is effective in measuring parts deformation and misalignment, thereby dramatically increasing the rate of success in assembly operations.

Flexible parts can be deformed by the contact forces during assembly on the contrary to rigid parts and thus their successful assembly requires information about their deformation as well as a misalignment between mating parts. However, because of the nonlinear and complex relationship between parts deformation and the reaction forces during assembly, it is difficult to acquire all required information from only the reaction forces. In this paper, we propose a visual sensing system for measuring parts deformation in any direction and a misalignment for flexible parts assembly. It is composed of a camera and a series of mirrors, and it can overcome the self-occlusion when a hole is occluded by mating parts. The simulation results show that the system can be effectively used for measuring parts deformation and a misalignment, thereby drastically increasing the success rate of assembly operation.