한국의 고령화와 의료산업

윤재중 대한전기학회 2018 전기의 세계 Vol.67 No.1

LED구동회로를 위한 새로운 LED단락 검출방법

윤재중(Jae-Jung Yun) 한국조명·전기설비학회 2020 조명·전기설비학회논문지 Vol.34 No.4

If some LEDs are shorted, overcurrent flows through an LED string consisting of multiple LEDs connected in series. In the LED driving circuit, a current regulator with semiconductor devices such as transistors can protect overcurrent but it generates heat in semiconductor devices, which can damage the LED driving circuit and LED string. In this paper, a novel LED short detection circuit is proposed to solve the LED short problem. The proposed circuit consists of an comparator and a MOSFET and operates in combination with a current regulator. It detects when the LED is shorted and then opens the transistor in current regulator so that the LED current does not flow. To verify the operation and effectiveness of the proposed circuit, a prototype of current regulator and short detection circuit was fabricated and tested by connecting to three LED strings. At LED diving voltage of 18V, The LED currents of all LED strings were 38.7mA∼39.1mA by the constant current operation of current regulators. When a LED is shorted in any LED string and the proposed circuit is not used, the collector-emitter voltage of the transistor in the current regulator was increased to 4.23V and the power consumption of 164.5mW is generated in the transistor. However, when using the proposed circuit, it protects the LED string and LED driving circuit by opening the transistor so that the LED current does not flow.

근대5종 대학선수의 슬관절 등속성 기능평가 및 진단 연구

강설중 ( Kang Seol-jung ),김영선 ( Kim Yeong-sun ),윤재량 ( Yoon Jae-ryang ) 한국체육대학교 체육과학연구소 2017 스포츠사이언스 Vol.35 No.1

본 연구는 근대5종 선수를 대상으로 하지관절인 무릎관절의 등속성 근관절 기능을 측정하여 슬관절의 주동근(신근력)과 길항근(굴근력)이 균형을 이루고 있는지를 진단, 평가하는데 있다. 본 연구에 참여한 연구대상은 서울 소재 K대학교 재학생 근대5종 선수 중 8명을 선정하였으며 선수경력 평균 9년 이상인 자를 대상으로 하였다. 근대5종 선수의 슬관절 등속성 기능평가를 하기 위해 피험자의 체성분을 측정 후 등속성 근관절(60°/sec, 240°/sec)를 수행하였다. 이에 대한 연구결과는 다음과 같다. 첫째, 좌측과 우측 슬관절 근력비(좌우비)의 균형여부 평가 결과, 신근력의 대퇴사두근에서는 좌측과 우측간에 비교적 정상적인 균형을 이루고 있으나 굴근력의 햄스트링근에서는 좌측에서 상대적으로 상당히 약한 것으로 나타났다. 따라서, 좌,우 양측 균형을 위해서는 슬관절의 햄스트링 근력강화 트레이닝이 필수적인 것으로 평가되었다. 둘째, 동측 슬관절의 근력비(굴신비)의 균형여부 평가 결과, 신근력의 주동근인 대퇴사두근은 대체로 정상에 가까운 수준을 보이고 있으나 굴곡근의 주동근인 좌, 우측 햄스트링근은 상당히 약한 것으로 나타났다. 따라서, 좌측과 우측 모두에서 슬관절의 햄스트링 근력강화 트레이닝이 필수적인 것으로 평가되었다. 선수 개인별 분석결과를 종합해보면, 본 연구에 참여한 근대5종 선수들은 지속적인 웨이트 운동과 같은 근력강화 트레이닝을 실시하되, 일정 주기별로 슬관절의 근기능 검사를 통해서 동측 근력비와 양측 굴신비의 불균형 여부를 평가하고, 이에 대한 적절한 근력 보강트레이닝, 특히 햄스트링근의 보강 트레이닝이 철저히 요구됨을 확인할 수 있었다. The purpose of this study is an analysis and diagnose isokinetic function of knee joints in modern pentathlon college athletes. The subjects of this study were 8 college athletes(9years over) of K university in Seoul. In order to evaluate the isokinetic function of the knee joints of the modern pentathlon athlete, the isokinetic test (60 ° / sec, 240 ° / sec) was performed after measuring the body composition of the subject. The results of this study are as follows. First, the balance between the left and right knee strength ratios (left to right ratio) was evaluated to be relatively normal balance between the right and left quadriceps muscles, but relatively weak in the hamstring muscles of the left flexor muscles. Therefore, it is estimated that hamstring strengthening training of the knee is essential for both left and right balance. Second, as a result of evaluating the balance of muscular strength (flexor/extensor ratio) of the isolateral knee, the quadriceps muscle of the extension muscle is near the normal level, but the left and right hamstring muscles of the flexor muscles are significantly weak. Therefore, it was evaluated that hamstring strengthening training of the knee was necessary in both the left and right side. In conclusion, the athletes perform strength training such as continuous weight training, and evaluate the imbalance of isolateral strength ratio and bilateral flexor- extensor ratio through the strength examination of the knee at regular intervals. In particular, it was confirmed that adequate hamstring strength training was required.

배터리 관리시스템을 위한 듀얼 능동 셀 밸런싱 회로

윤재중(Jae-Jung Yun),최윤걸(Yoon-Geol Choi),이상원(Sang-Won Lee) 대한전기학회 2016 대한전기학회 학술대회 논문집 Vol.2016 No.3

급성 유기인계 중독과 관련된 초기 심전도 변화

이환중,윤재철,정태오,진영호,이재백,Lee, Hwan-Jung,Yoon, Jae-Chol,Jeong, Tae-O,Jin, Young-Ho,Lee, Jae-Baek 대한임상독성학회 2009 대한임상독성학회지 Vol.7 No.2

Purpose: Various electrocardiogram (ECG) changes can occur in patients with acute organophosphate poisoning (OPP) and may be associated with the clinical severity of poisoning. The present study aimed to evaluate the extent and frequency of ECG changes and cardiac manifestations, and their association with acute OPP clinical severity. Methods: Seventy-two adult patients admitted to our emergency department with a diagnosis of acute OPP were studied retrospectively. ECG changes and cardiac manifestations at admission were evaluated. ECG changes between respiratory failure (RF) group and no respiratory failure (no RF) groups were compared. Results: Prolongation of QTc interval (n=40, 55.6%) was the most common ECG change, followed by sinus tachycardia (n=36, 50.0%). ST-T wave changes such as ST segment elevation or depression and T wave change (inversion or non-specific change) were evident in 16 patients (22.2%). Prolongation of QTc interval was significantly higher in the RF group compared with the no RF group (p=0.03), but was not an independent predictor for RF in acute OPP (OR; 4.00, 95% CI; 0.70-23.12, p=0.12). Conclusion: While patients with acute OPP can display ECG changes that include prolongation of QTc interval, sinus tachycardia, and ST-T wave changes at admission, these changes are not predictors of respiratory failure.

중년 남성 소방관의 심폐체력과 동맥경직도, 심박수변이도 및 수면의 질 간의 연관성

강설중,고광준,하지철,윤재량 대한운동학회 2017 아시아 운동학 학술지 Vol.19 No.2

[PURPOSE] The aim of this study was the relationship between cardiovascular fitness and arterial stiffness, heart rate variability, and quality of sleep in middle-aged male firefighters. [METHODS] The subjects were 180 firefighters who were examined for cardiovascular fitness, arterial stiffness, heart rate variability, and sleep quality at the National Fitness Center in 2016. The maximal oxygen uptake was measured by exercise test. The marker of arterial stiffness was the brachial-ankle pulse wave velocity. The heart rate variability index used time domain analysis and frequency domain. The quality of sleep was assessed by the quality index of the Korean version of Pittsburgh. [RESULTS] There was a correlation between cardiorespiratory fitness and arterial stiffness(r=-0.292, p<.05). LF/HF in cardiovascular fitness and heart rate variability(r=-0.318, p<.05). However, there was no correlation between cardiorespiratory fitness and sleep quality. [CONCLUSIONS] These results can be used as a basis for judging the importance of cardiorespiratory fitness enhancement to prevent the risk of cardiovascular disease in firefighters

유방암 환자와 정상여성의 혈액 및 지방조직중 PCBs 형태에 관한 연구

노영만,이강숙,윤재중,구정완,임현우 한국보건교육건강증진학회 2000 한국보건교육·건강증진학회 학술대회 발표논문집 Vol.- No.-

시린지리스 전기방사를 통한 부직포 기반 건조 콜라겐 마스크팩 제조

정한진,이소연,윤재중,이경진 한국고분자학회 2022 폴리머 Vol.46 No.3

마스크 팩은 다양한 유효 물질을 함유하며 피부 개선을 위해 이용되고 있으나, 최근 1회용 플라스틱 지지체 이용의 최소화를 위해 건조 형태의 마스크 팩에 대한 많은 연구가 진행되고 있다. 본 연구에서는 유효 물질인 저분자량 콜라겐과 고분자량 히알루론산을 기반으로 하여 시린지리스 전기방사를 통해 나노 섬유 부직포를 제조하였다. 이를 통해 마스크 팩의 표면적을 향상시키고 유효 물질의 전달 속도를 개선하고자 하였다. 고분자 용액 조성을 조절하고 모폴로지를 관찰하여 전기 방사성이 용이하면서도 유효 물질인 콜라겐이 다량 함유된 부직포 기반 마스크팩을 제조할 수 있었다. 또한 물 분사 시 건조된 콜라겐 부직포가 용해되는 것을 통해 건조 마스크 팩으로서의 응용 가능성을 확인하였다.

수동 셀 밸런싱 알고리즘 비교 분석을 통한 밸런싱 최적화에 관한 연구

이재형(Jaehyung Lee),윤재중(Jaejung Yun) 한국자동차공학회 2023 한국자동차공학회 학술대회 및 전시회 Vol.2023 No.11

The passive cell balancing techniques currently commercialized in electric vehicles and railway vehicles include algorithms based on minimum and average voltage values and smart balancing algorithms proposed by TI. The balancing speed and efficiency of these techniques differ depending on the battery type and application, and optimization is required to improve performance and stability depending on the requirements of the system. Therefore, this paper constructed a BMS test bench with a Mater-Slave structure using an LFP battery module to optimize the balancing algorithm. The balancing operation range for experiments of the each algorithm was set between OCV at 80% SOC and full charge voltage. The experimental results of the minimum voltage based algorithm showed that the balancing efficiency was 86.7% and the charging speed was slow. The results of the average voltage based algorithm showed that balancing efficiency was 90% and the charging speed was fast. The smart balancing algorithm had the fastest charging speed but the balancing efficiency was low at 85.3%. Based on the results of each balancing algorithm, we researched to optimize the balancing method to improve the performance and efficiency of a battery system.

GaN FET 기반 플라이백 컨버터를 이용한 능동 셀 밸런싱의 성능 향상

최영훈(Young-Hoon Choi),윤재중(Jae-Jung Yun) 한국조명·전기설비학회 2022 조명·전기설비학회논문지 Vol.36 No.2

In a battery module with multiple cells in series, the efficiency of the cell balancing circuit is very important because it is related to the balancing time and energy usage. This paper proposes a high efficiency active cell balancing circuit that can transfer energy from module to cell. The proposed balancing circuit consists of a flyback converter for transferring energy and bidirectional switches for selecting a weak cell. In order for the proposed circuit to have high efficiency, the flyback converter uses GaN FETs with excellent electrical characteristics and operates in DCM(Discontinuous Conduction Mode) for soft switching. To verify the performance of the proposed circuit, a 5W GaN FET based flyback converter was built and cell balancing experiments was performed. This was compared to a MOSFET based balancing circuit. Experimental results show that the proposed circuit improves maximum efficiency by 8.6%, reduces cell balancing time by 10%, and reduces cell balancing energy loss by 16% compared to the MOSFET-based circuit.