• The Journal of Korean Physical Therapy
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• 제20권3호
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• pp.9-18
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• 2008

Purpose: We determined the effect of global synkinesis(GS) on gait ability, muscle contraction, and central neuron action potentials in post-stroke hemiplegic subjects. Methods: Thirty hemiplegia patients were evaluated for walking ability, muscle contraction, central neuron action potential, and comparing differences between the H-GS(high-global synkinesis) group and L-GS(low-global synkinesis) group. To obtain the GS level, surface electromyography(EMG) data were digitized and processed to root mean square(RMS). Walking ability was tested with a modified motor assessment scale(MMAS), a 10 m walking test, timed up and go(TUG) test, and a Fugl-Meyer assessment(FMA). Muscle contraction ability was measured as maximal isometric contraction(MIC) peak, MIC slope, and MIC ramp up using mechanomyography(MMG). Central neuron action potential was measured as the H/Mmax ratio or V/Mmax ratio using EMG. The data were analyzed with t-tests to determine the statistical significance. Results: MMAS(p<0.01), 10 m walking velocity(p<0.01), TUG(p<0.01), FMA-HKA(Hip, Knee, Ankle)(p<0.05), FMA-coordination(p<0.05), MIC peak (p<0.05), MIC slope(p<0.01), and MIC ramp up(p<0.05) were significantly different between H-GS and L-GS, as was the V/Mmax ratio(p<0.05), but H/Mmax was not. Conclusion: Lower GS levels indicated better walking ability and motor function. Therefore, intervention programs should consider GS levels in gait training of chronic hemiplegia.

• 대한전자공학회논문지SD
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• 제47권6호
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• pp.13-21
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• 2010

본 논문에서는 가변 펌핑 클록 주파수를 이용한 모바일 D랩용 고효율 승압 전압 발생기를 제안한다. 제안된 승압 전압 발생기는 효율을 높이기 위해서 3단 Cross-coupled 점하 펌프를 사용하였으며, 또한 최종 출력 전압의 승압 시간을 줄이기 위해 기존의 승압 전압 발생기에서 사용되는 고정된 펌핑 클록 주파수 대신 전압 제어 발생기를 사용하여 펌핑 클록 주파수을 가변하였다. 따라서 제안된 승압 전압 발생기는 1.2 V 전원 전압, 최대 2 mA의 부하 전류, 1 nF의 부하 캐퍼시터 조건에서 24.0-${\mu}s$안에 3.0 V의 최종 출력 전압을 승압할 수 있다. 실험 결과 제안된 승압 전압 발생기는 에너지 소비를 26% (1573 nJ $\rightarrow$ 1162 nJ), 승압 시간을 29% (33.7-${\mu}s$ $\rightarrow$ 24.0-${\mu}s$) 감소시켰다. 따라서 제안된 승압 전압 발생기를 사용함으로써, 높은 에너지 효율과 빠른 승압을 동시에 구현할 수 있다.

• 한국운동역학회지
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• 제18권3호
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• pp.71-82
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• 2008

본 연구의 목적은 $20^{\circ}$ 경사로에 서 앞 뒤 보행 동작 시 지면반력 형태를 비교 분석하고자 한다. 본 연구를 위해서 두 대의 지면 반력기를 통해 전 후, 좌 우, 수직 지면반력값, 최대값, 최소값, 평균값 압력 중심 변위, 부하율과 감소율을 측정하였다. BD보행 시 RTO 시점에서 수직 지면반력값이 FU 보행에 비해 유의하게 높은 수치를 보인 반면, $RHC_2$ 시점에서는 더 낮은 수치를 보였다. 이는 보행 동작의 차이와 보행 시 발목과 무릎의 위치 변화, 무게 중심의 변화가 지면 반력의 형태에 직접적인 영향을 미치는 것으로 판단되어진다. 전 후 압력중심변위는 하향 보행 시 상향 보행에 비해 낮은 변화를 보였는데 이는 하향 시 생기는 불안정성을 상쇄하기 위해 더 강한 제동력이 발생되어 진 것으로 사료되어 진다. BD보행 시 부하율이 다른 보행에 비해 낮은 것을 알 수 있는데 이러한 결과를 통해 등산로에서 후방 보행 동작이 하지 근골격계에 지속적인 스트레스를 감소시켜 상해를 예방할 수 있는 방법으로 제시될 수 있을 것이다.

• 한국초전도ㆍ저온공학회논문지
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• 제2권1호
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• pp.19-23
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• 2000

We are developing a small-sized superconducting magnetic energy storge ($\mu$SMES) magnet with the storage capacity of a few megajoules, which provides electric power with high quality to sensitive electric loads. A kA class superconductor with a high coppe $r^erconductor ratio was selected as a candidate conductor. The superconductor was tested in two points of view, which are basic and important in development of the $\mu$SMES magnet. First, stabilities of the superconductor against localized disturbances such as wire motions were estimated by using a wire heater. Second, the quench current characteristics for different charge rates were also tested. The stability data showed that the short heat pulses made the conductor more unstable. The superconductor had relatively high recovery currents ranging between 40% and 50% of its critical currents. The quench tests indicated that the quench currents of the conductor were independent of current ramp rates up to 3000 A/s and nearly equal to its cuitical current data.ta.

• Journal of Information Display
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• 제7권1호
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• pp.25-29
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• 2006

By the voltage threshold (Vt) close-curve measurement method, the changes in the discharge characteristics such as a firing voltage and IR emission among the three electrodes were examined relative to the low or high panel temperature ranging from -10 to $80^{\circ}$. The variation in the panel temperature was found significantly influence the surface discharge between the MgO surfaces rather than the plate gap discharge between the MgO and phosphor layers. Based on this experimental observation, a modified reset waveform that alleviates the surface discharge during a ramp-up and -down period was deeloped. By adopting the proposed reset waveform, a stable address discharge could be obtained irrespective of the panel temperature variation.

• 전기전자학회논문지
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• 제20권1호
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• pp.75-81
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• 2016

본 논문은 SIMT(Single Instruction Multi Thread)구조 GP-GPU(General Purpose Graphic Processing Unit)에서 그래픽 어플리케이션 성능을 향상시키기 위해 타일 기반 그래픽 파이프라인 구조를 제안한다. 타일 기반 그래픽 파이프라인 구조는 병렬적으로 Rasterization 단계를 처리하고, 불필요한 그래픽 처리 연산은 수행하지 않는다. SIMT구조를 통해 대용량 데이터를 병렬로 처리하여 연산 성능을 향상시켰고, 이는 3D 그래픽 파이프라인 처리의 성능을 향상하였다. 제안하는 구조를 통해 3D 그래픽 어플리케이션을 처리할 때 3D 모델을 구성하는 정점 데이터가 많아 질수록 높은 효율을 보인다. 제안하는 구조는 'RAMP'와 기존의 선행 연구를 비교하여 약 1.18배에서 최대 3배까지의 처리 성능 향상을 확인하였다.

• 인간식물환경학회지
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• 제24권1호
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• pp.85-94
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• 2021

Background and objective: This study examined, compared, and analyzed the tree vitality of the trees growing on the artificial ground of Seoullo 7017 that transformed the overpass that was to be demolished into a "sky garden" using portable tree pots. Methods: Based on the summer season when the metabolic activity of plants is most active, this study measured the cambial electrical resistance in four directions(east, west, south and north), using the Shigometer (model OZ-93, Osmose) and compared the location and analysis of pots according to their means and standard errors. Results: Meanwhile, according to the analysis, vitality was relatively superior in pots with a big diameter, trees planted individually than in groups, trees of the ramp section rather than the bridge section, and in the southwest direction of the cambium. Conclusion: This study revealed the improper condition of the planting plan and implementation on the site, where various species of trees are displayed in a poor environment. Despite the significant assessment of the vitality of various trees introduced within Seoullo 7017 for the first time, this study is limited in that the data used were measured only once in summer. In this regard, it raised the need for continuous interest in and monitoring of a special plant environment and development of proper maintenance and management techniques, along with follow-up research on seasonal and temperature conditions, soil moisture and root development conditions to supplement this research.

• 한국안전학회지
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• 제30권5호
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• pp.8-13
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• 2015

Molded Case Circuit Breakers (MCCBs) are typically used to provide over current protection for electrical safety caused by short circuit faults and overloads in indoor low voltage power systems. The MCCB automatically connects and disconnects loads from the electrical source when the current reaches a value and duration that will cause an excessive. However, the MCCB sometimes is not interrupted due to a malfunction, nuisance tripping, or in a fire. Ensuring electrical safety is very important in a indoor low voltage power system. This paper presents the operating characteristics of MCCBs according to a temperature rise from room temperature to 160 degrees Celsius delivered by a radiant panel heater. The ABS 54c(rated current: 30A) of the hydraulic magnetic trip type was used in the experiments. The signals of temperature, voltage, and current were measured using the high accuracy Signal Conditioning Extensions for Instrumentation (SCXI) measurement system with the LabVIEW program manufactured by National Instruments. The operating characteristics were measured as functions of current amplitude and ramp-up rate. The MCCB tripping time decreased as a result of increasing current amplitude and ramp-up rate under a temperature rise condition, because the temperature and level of the current are directly proportional to the tripping time. Additionally, an instantaneous operation was observed after 8 times of the rated current, and the MCCB began to melt a surface temperature of around 300 degrees Celsius of. The experimental results coincided well with the operating curve.

• 전자통신동향분석
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• 제34권1호
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• pp.75-85
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• 2019

Quantum technology is undergoing a revolution. Theoretically, strange phenomena of quantum mechanics, such as superposition and entanglement, can enable high-performance computing, unconditionally secure communication, and high-precision sensing. Such theoretical possibilities have been examined in the last few decades. The goal now is to apply these quantum advantages to daily life. Europe, where quantum mechanics was born a 100 years ago, is struggling to be placed at the front of this quantum revolution. Thus, the European Commission has decided to invest 1 billion EUR over 10 years and has initiated the ramp-up phase with 20 projects in the fields of communication, simulation, sensing and metrology, computing, and fundamental science. This program, approved by the European Commission, is called the "Quantum Technology Flagship" program. Its first objective is to consolidate and expand European scientific leadership and excellence in quantum research. Its second objective is to kick-start a competitive European industry in quantum technology and develop future global industrial leaders. Its final objective is to make Europe a dynamic and attractive region for innovative and collaborative research and business in quantum technology. This program also trains next-generation quantum engineers to achieve a world-leading position in quantum technology. However, the most important principle of this program is to realize quantum technology and introduce it to the market. To this end, the program emphasizes that academic institutes and industries in Europe have to collaborate to research and develop quantum technology. They believe that without commercialization, no technology can be developed to its full potential. In this study, we review the strategy of the Quantum Europe Flagship program and the 20 projects of the ramp-up phase.

• 수산해양기술연구
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• 제35권2호
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• pp.161-169
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• 1999

본 논문은 개량식 정치망내에 방류한 체장 30 cm의 부시리, Seriola aureovittata의 유영행동 및 탈출행동을 텔레메트리기법으로 추적하고, 그 결과를 기술한 것이다. 압력센서를 내장한 초음파 핑거를 부착시켜 방류한 시험어의 행동은 장기선 방식의 어군행동 원격감시 시스템을 사용하여 추적하였다. 수신점의 수는 3개였고, 초음파 핑거의 3차원 위치는 쌍곡선위치결정법으로 구한 평면좌표 x, y와 압력센서로 관측한 심도 z를 사용하여 구하였다. 실험에서 얻은 결과는 다음과 같다. 1. 시험어는, 방류직후,15 m 깊이까지 급잠하였다가 수면가까이 부상하는 행동을 보였고, 방류직후부터 5분간 측정한 평균 유영속도는 0.87 m/sec를 나타내었다. 2. 시간이 경과함에 따라 시험어의 유영속도는 점차 느려지는 경향을 나타내었고, 방류후 1시간정도 경과한 때부터는 주로 헛통쪽 비탈그물 부근에서 섬도 1～7 m 에 머물면서 탈출을 시도하는 행동을 보였다. 이 시간대의 평균 유영속도는 0.52 m/sec로 나타났다. 3. 양망을 시작하여 25분정도가 경과하기까지는 시험어가 1단계 비탈그물에서 벗어나 2단계 원통쪽으로 도피하면서 1단계 원통그물의 구석까지 빠른 속도로 왕복하는 수평 유영행동을 보였고, 수직적으로는 심도 20 m 까지 하강하였다가 다시 표층으로 부상하는 행동을 나타내었다. 그 이후 시간에는 양망 중임에도 불구하고 다시 1 단계 비탈그물 부근에 머물면서 헛통쪽으로 탈출하고자하는 행동을 나타내었고, 양망 중에 헛통으로 탈출한 것으로 나타났다. 양망 초기의 평균 유영속도는 양망직전의 유영속도에 비하여 38.5 % 증가한 0.72 m/sec (체장의 2.4 배)였으며, 방류 후 1단계 원통을 탈출할 때까지 측정한 평균 유영속도는 0.67 m/sec로 체장대비 2.2배의 빠르기였다.