• Journal of Electrodiagnosis and Neuromuscular Diseases
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• v.20 no.2
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• pp.130-134
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• 2018

A 36-year-old male patient developed diffuse low back pain. His past medical history was unremarkable and had no family history of neuromuscular disease. He had no bladder and bowel problems. Creatine kinase was 172 U/L (normal < 170). Other fluid and blood chemistry tests were normal. Manual muscle test grades of extremities and sensory examination were normal. Muscle stretch reflexes were normal. Fasciculations and myotonia were not detected. Straight leg raising test was negative. There was no spinal root compression, spinal stenosis, or signal intensity change of spinal cord on magnetic resonance imaging (MRI). Fatty change and atrophy of the cervical, thoracic and lumbar paraspinal muscles were noted on MRI. Nerve conduction studies were normal. Electromyography showed 1+ positive sharp waves in the lumbar paraspinal muscles. Electromyography of upper and lower extremity muscles revealed no abnormal spontaneous activity. We report a rare case of severe paraspinal muscle atrophy with fatty degeneration in a Young Adult.

• Journal of Sensor Science and Technology
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• v.30 no.1
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• pp.61-65
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• 2021

In this study, we propose a 2500 frame per second (fps) high-speed binary complementary metal oxide semiconductor (CMOS) image sensor using a gate/body-tied (GBT) p-channel metal oxide semiconductor field effect transistor-type high-speed photodetector. The GBT photodetector generates a photocurrent that is several hundred times larger than that of a conventional N+/P-substrate photodetector. By implementing an additional binary operation for the GBT photodetector with such high-sensitivity characteristics, a high-speed operation of approximately 2500 fps was confirmed through the output image. The circuit for binary operation was designed with a comparator and 1-bit memory. Therefore, the proposed binary CMOS image sensor does not require an additional analog-to-digital converter (ADC). The proposed 2500 fps high-speed operation binary CMOS image sensor was fabricated and measured using standard CMOS process.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.1425-1428
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• 2013

이 기술은 CCTV의 본연의 목적인 범죄 예방을 좀 더 효과적이고 효율적으로 하기 위해 개발하였다. 먼저 사용 공간에 제약을 줄이기 위해 와이파이 기반의 CCTV를 사용하기로 하였다. 그리고 단순히 영상을 수집하는 것이 아니라 아래와 같은 알고리즘을 영상에 적용하여 범죄 예방을 위한 판단을 좀 더 빠르고 정확하게 할 수 있도록 하였다. 첫 번째로 배경에서 객체들을 분리한 뒤 각각의 객체들을 labeling하여 서로를 구분하였다. 그 후 특징점을 이용해 각 객체들을 추적한 뒤 객체마다 적당한 관심영역을 설정한다. 관심영역에서 색을 이용한 외부인 침입 감지기능과 객체의 속도와 방향을 이용한 폭력적인 행동 감지기능을 적용하였다. 더 나아가 사용자의 편의를 위해 서버/클라이언트 모델을 사용하여 외부인 침입이나 폭력이 감지되면 서버가 클라이언트에게 경고 메시지와 함께 현재 상태를 이미지로 보낼 수 있도록 하였고 클라이언트가 원한다면 언제든지 실시간 영상도 볼 수 있도록 하였다.

• Journal of Sensor Science and Technology
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• v.30 no.2
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• pp.119-124
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• 2021

Isolation and separation of biological nanoparticles, such as cells and extracellular vesicles, are important techniques for their characterization. Dielectrophoresis (DEP) based on microfluidic chips is an effective method to isolate and separate the nanoparticles. However, the electrodes of the DEP chips are electrolyzed by the electrical signals applied to the nanoparticles. Thus, the isolation/separation efficiency of the nanoparticles is reduced considerably. Through this study, we developed a microfluidic DEP chip for reliable isolation/ separation of nanoparticles and developed a passivation technique for the protection of the DEP chip electrodes. The electrode passivation process was designed using a hydrogel and the stability of the hydrogel passivation layer was verified. The fabricated DEP chip and the proposed passivation technique were used for the collection and dispersion of the fluorescent polystyrene nanoparticles. The proposed chip and the technique for isolation and separation of nanoparticles can be leveraged in various bioelectronic applications.

• Journal of Sensor Science and Technology
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• v.30 no.2
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• pp.105-108
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• 2021

Detection and localization of partial discharge are considered critical techniques for estimating the lifetimes of power cables. High-frequency current transformers (HFCTs) are commonly used for the detection of partial discharge in high-voltage alternating current (HVAC) power cables; however, their applicability is compromised by the limitations of the installation locations. HFCTs are typically installed in cable terminals or insulation joint boxes because HVACs induce strong time-varying magnetic fields around the cables, saturating the ferromagnetic materials in the HFCTs. Therefore, partial discharges near the installation locations can be detected. In this study, the feasibility of partial discharge detection using a HFCT was investigated for high-voltage direct current (HVDC) cables. We demonstrated that the HFCT could be installed at any location in the HVDC power cable to monitor partial discharge along the entire cable length. Furthermore, we showed that the HFCT could detect the location of partial discharge with high accuracy.

• Transactions of the Korean hydrogen and new energy society
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• v.32 no.6
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• pp.464-469
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• 2021

A reforming catalyst for hydrogen production from ammonia is being studied. Non-novel metal based Ni catalysts for use in ammonia reforming processes are being developed. In this study, the ammonia reforming characteristics according to Ni content of the alumina pellet supported catalyst in the mid-temperature region were investigated under different space velocity. 20 Ni and 3,000 h^-1 showed the best catalytic activity with ammonia conversion of 63% among all conditions.

• Journal of the Korean Wood Science and Technology
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• v.31 no.1
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• pp.16-21
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• 2003

The methanol extractives from root bark of Ulmus davidiana var japonica nakai were fractionated with n-hexane, ethyl ether, ethyl acetate and waster, the water soluble fraction was also fractionated with silicagel column chromatograhy. The chemical structure of purifided compounds were identified with UV, IR, ¹H-NMR and ¹³C-NMR spectra and the antibacterial activities also were investigated. Two different antibacterial compounds (compound A and B) were fractionated with silicagel chromatography and TLC. Compounds B was identified as a catechin rahmnoside. The both of compounds had antibacterial activity on Staphylococcus aureus and Salmonella typhimurium.

• Journal of ILASS-Korea
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• v.27 no.4
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• pp.173-180
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• 2022

Cooling fog is being used in various parts of society such as fine dust reduction, cleanliness, and temperature drop. Cooling fog has the advantage of low flow rate and ease of use compared to other spray systems. In the case of cooling fog, it was confirmed that the injection angle increased as the pressure increased and the nozzle diameter increased. In this study, the minimum injection angle was 33.61 degrees and the maximum injection angle was 107.38 degrees. It was confirmed that the larger the nozzle diameter and the smaller the pressure, the larger the droplet size. In addition, it was confirmed that the Sauter Mean Diameter (SMD) increased along the X and Y axis directions. It was confirmed that the size of the droplet decreases as it approaches the nozzle tip due to the characteristics of the nozzle design factor.

• Korean Journal of Poultry Science
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• v.49 no.4
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• pp.265-272
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• 2022

Many studies on poultry have been conducted in the poultry industry to improve their important economic traits, such as egg production, meat quality, and carcass yield. Environmental changes affect the poultry's economic traits, including muscle growth. The purpose of this study is to investigate the mechanisms by which simvastatin causes muscle injury in quail muscle cells. Following treatment with various doses of simvastatin, LD50 in the quail myoblast cells was determined using a cell viability test; cell death was caused by apoptosis and/or necrosis. Thereafter, the expression patterns of the atrophy marker genes were examined via quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The results showed that the transcriptional levels of the muscle atrophy marker genes (Atrogin-1, TRIM63) and the upstream genes in their signaling cascade were increased by simvastatin treatment. This indicated that simvastatin induced myogenic cell death and muscle injury via protein degradation through muscle atrophy signaling. Further studies should focus on identifying the mechanism by which simvastatin induces the protein degradation signaling pathway in quail muscle..

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.97-97
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• 2023

최근 재해분야에서 인공신경망(ANN), 기계학습(ML), 딥러닝(DL) 등 AI 기술이 활용성이 점차 증가하고 있으며, 센싱정보와 연계한 시설물 안전관리, 원격탐사와 연계한 재해감시(녹조, 산사태, 산불 등), 수문시계열(수위, 유량 등) 예측, 레이더·위성강수 자료의 보정과 예측, 상하수도 관망누수예측 등 다양한 분야에서 AI 기술이 적용되고 그 활용성이 검증된 바 있다. 본 연구에서는 ML, DL, 물리기반신경망(Pysics-informed Neural Networks, PINNs)을 이용한 다양한 재해분석 사례를 소개하고, 그 활용성과 한계에 대해서 논의하고자 한다. 주요사례로는 (1) SAR영상과 기계학습을 이용한 재해피해지역(울진 산불) 감지, (2) 국가 디지털 정보를 이용한 산사태 위험지역 판별(인제 산사태) (3) 기계학습 및 딥러닝 기법을 이용한 위성강수 자료의 보정·예측 및 유출해석, (4) 수리해석을 위한 수치해석분야에서의 PINNs의 적용성(1차원 Saint-Venant 식 해석) 평가 연구결과를 공유한다. 특히, 자료의 입·출력 자료만으로 학습된 인공신경망 모형 대신 지배방정식(물리방정식)을 만족하도록 강제한 PINNs의 경우, 인공신경망 모형보다 우수한 모의능력을 보여주었으며, 향후 복잡한 수리모델링 등 수치해석분야에서 그 활용가능성이 매우 높을 것으로 판단된다.