• Journal of Power Electronics
• /
• 제7권1호
• /
• pp.28-37
• /
• 2007

A new PWM-controlled quasi-resonant converter for a high efficiency PDP sustaining power module is proposed in this paper. The load regulation of the proposed converter can be achieved by controlling the ripple of the resonant voltage across the resonant capacitor with a bi-directional auxiliary circuit, while the main switches are operating at a fixed duty ratio and fixed switching frequency. Hence, the waveforms of the currents can be expected to be optimized from the view-point of conduction loss. Furthermore, the proposed converter has good ZVS capability, simple control circuits, no high voltage ringing problem of rectifier diodes, no DC offset of the magnetizing current and low voltage stresses of power switches. In this paper, operational principles, features of the proposed converter, and analysis and design considerations are presented. Experimental results demonstrate that the output voltage can be controlled well by the auxiliary circuit using the PWM method.

• 한국과학기술학회:학술대회논문집
• /
• 한국과학기술학회 2015년도 후기 학술대회
• /
• pp.247-278
• /
• 2015

최근 한국에서도 DNR(소생거부)이 확산됨에 따라 의료적으로 무의미한 연명치료에 대한 논의가 심화되고 있다. 이와 연관된 법원의 판례도 생명윤리와 연관된 정책적 거버넌스적 측면에서 주목을 받고 있는데, 가령 '무의미한연명치료장치제거등'에 관한 대법원 선고(대법원 2009.5.21, 선고, 2009다 17417, 전원합의제 판결) 등은 언론에서도 소개되었을 정도로 시민사회의 공공영역에서 많은 논쟁을 촉발하였다. 이런 사례들은 이전의 의료기술로는 생명유지가 어려운 환자에 대한 신기술 개발 및 적용을 통한 소생과 연명치료가 가능해지면서, 이와 연계된 기술적 거버넌스의 논의가 필요함을 우리에게 보여준다. 본 연구는 첫째, 한국 사회에서 최근 이루어지고 있는 존엄사 및 연명의료와 관련된 정책적, 법적 이슈들을 40여 편의 선행연구를 분석하여 메타적으로 정리한다. 둘째, 생명윤리정책적 관점에서 연명의료기술의 거버넌스가 새로운 윤리적(thanatoethics), 정책적(thanatopolitics) 함의를 우리에게 제시함을 보인다. 이런 관점의 연장선상에서 바라보면, 연명의료 중단을 통한 자발적 존엄사의 선택은 타나토권력(thanatopower)을 주체에게 복속시키는 행위로도 볼 수 있다. 연명 소생기술이 극단적으로 발전하면서 기술의 정책적 함의를 분석함에 있어 이처럼 새로운 개념을 도입할 필요성도 요청된다. 마지막으로 기술 거버넌스 영역에서 최근 주목받는 사회에 책임지는 기술(responsible research and innovation, RRI)은, 연명 및 소생기술의 혁신에도 적용된 바 있다. '간펀화된 자동제세동기(AED)'의 개발이 한 사례이다 기술의 사용주체인 시민사회에서 DNR등을 통해 해당 기술의 사용을 거부하는 경우, 이는 RRI의 한계로 드러나게 된다. 그럼에도 불구하고 아직까지 RRI의 기술혁신을 진행함에 있어 이런 측면은 그다지 고려되지 않는다. 연명의료기술을 개발하고 정책적으로 적용하는 단계에서 앞으로 이런 점은 함께 고려될 필요가 있다.

• 산업융합연구
• /
• 제17권2호
• /
• pp.53-61
• /
• 2019

본 연구는 간호대학생의 도덕적 민감성, 생명의료윤리의식이 연명치료중단에 대한 태도에 미치는 영향을 파악하기 위한 서술적 조사연구이다. 연구대상자는 D시 소재의 일개 간호학과 1, 2학년 학생 302명이었으며, 구조화된 설문지를 이용하여 자료를 수집하였다. 연구결과, 간호대학생의 도덕적 민감성 정도는 보통 수준이었고, 생명의료윤리인식정도는 높은 수준이었으며, 연명치료중단에 대한 태도는 긍정적인 것으로 나타났다. 또한 도덕적 민감성은 생명의료윤리의식(r=.149, p=.010), 연명치료중단(r=.223 p<001)과 유의한 정적 상관관계를, 생명의료윤리의식과 연명치료중단은 유의한 부적상관관계(r=-.129 p=.025)를 나타내었다. 도덕적 민감성(${\beta}=.247$, p<.001)과 생명의료윤리의식(${\beta}=-.166$, p=.003)은 연명치료중단에 대한 태도에 유의한 영향을 미치는 요인으로 확인되었다. 따라서 대상자의 도덕적 민감성, 생명의료 윤리의식 수준과 내용을 고려한 차별화된 연명치료중단에 대한 교육을 적용해야 할 것으로 생각된다.

• Journal of Power Electronics
• /
• 제5권1호
• /
• pp.67-75
• /
• 2005

A high efficiency ZVS PWM asymmetrical half bridge converter for a plasma display panel (PDP) sustaining power modules is proposed in this paper. To achieve the ZVS of power switches for the wide load range, a small additional inductor L/sub 1kg/, which also acts as an output filter inductor, is serially inserted into the transformer's primary side. At that point, to solve the problem of ringing in the secondary rectifier caused by L/sub 1kg/, the proposed circuit employs a structure without the output filter inductor, which helps the voltages across rectifier diodes to be clamped at the output voltage. Therefore, no dissipative RC (resistor capacitor) snubber for rectifier diodes is needed and a high efficiency as well as low noise output voltage can be realized. In addition, since it has no large output inductor filter, the asymmetrical half bridge converter features a simpler structure, lower cost, less mass, and lighter weight. In addition, since all energy stored in L/sub 1kg/ is transferred to the output side, the circulating energy problem can be effectively solved. The operational principle, theoretical analysis, and design considerations are presented. To confirm the operation, validity, and features of the proposed circuit, experimental results from a 425W, 385Vdc/170Vdc prototype are presented.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2004년도 전력전자학술대회 논문집(2)
• /
• pp.723-727
• /
• 2004

A new high-performance and low cost single switch energy recovery display driver for an AC plasma display panel (PDP) is proposed. Since it is composed of only one auxiliary power switch, two small inductors, and eight diodes compared with the conventional circuit consisting of four auxiliary power switches, two small inductors, eight power diodes, and two external capacitors, it features a much simpler structure and lower cost. Nevertheless, since the rootmean-square (RMS) value of the inductor current is very small, it also has very desirable advantages such as n low conduction loss and high efficiency. Furthermore, there are no serious voltage-drops caused by the large gas-discharge current with the aid of the discharge current compensation, which can also greatly reduce the current flowing through power switches and maintain the panel to light at n lower sustaining voltage. In addition, all main power switches are turned on under the zero-voltage switching (ZVS) and thus, the proposed circuit has a improved EMI, increased reliability, and high efficiency. Therefore, the proposed circuit will be well suited to the wall hanging PDP TV. To confirm the validity of the proposed circuit, circuit operations, features,and design considerations are presented and verified experimentally on a 6-inch PDP, 50kHz-switching frequency, and sustaining voltage 141V based prototype.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2004년도 전력전자학술대회 논문집(2)
• /
• pp.537-541
• /
• 2004

A high efficiency ZVS PWM asymmetrical half bridge converter for a plasma display panel (PDP) sustaining power module is proposed in this paper. To achieve the ZVS of power switches for the wide fond range, n small additional inductor $L_{lkg}$, which also acts as an output filter inductor, is serially inserted to the transformer primary side. Then, to solve the problem related to ringing in the secondary rectifier caused by $L_{lkg}$, the proposed circuit employs a structure without the output filter inductor, which helps the voltages across rectifier diodes to be clamped at the output voltage. Therefore, no dissipative RC (resistor capacitor) snubber for rectifier diodes is needed and n high efficiency as well as low noise output voltage can be realized. In addition, since it has no large output inductor filter, it features a simpler structure, lower cost, less mass, and lighter weight. Moreover, since all energy stored in $L_{lkg}$ is transferred to the output side, the circulating energy problem can be effectively solved. The operational principle, theoretical analysis, and design considerations are presented. To confirm the operation, validity, and features of the proposed circuit, experimental results from a 425W, 385Vdc/170Vdc prototype are presented.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2005년도 전력전자학술대회 논문집
• /
• pp.380-384
• /
• 2005

Plasma display panel (PDP) has a serious thermal problem, because the luminance efficiency of the conventional PDP is about 1.5 lm/W and it is less than $3{\sim}5$ lm/W of cathode ray tube (CRT). Thus there is a need for improving the luminance efficiency of the PDP There are several approaches to improve the luminance efficiency of the PDP and we adopt the driving PDP at high frequency range from 400 kHz up to over 700 kHz. Since a PDP is regarded as an equivalent inherent capacitance, many types of sustaining drivers have been proposed and widely used to recover the energy stored in the PDP. However, these circuits have some drawbacks for driving PDP at high frequency range. In this paper, we investigate the effect of the parasitic components of PDP itself and driver when the reactive energy of panel is recovered. Various drivers are classified and evaluated whether it is suitable for high frequency driver, and finally current-fed type with do input voltage biased is proposed. This driver overcomes the effect of parasitic component in panel and driver and fully achieves ZVS of all full-bridge switches and reduces the transition time of the panel polarity.

• 지역사회간호학회지
• /
• 제32권4호
• /
• pp.445-456
• /
• 2021

Purpose: This study was conducted to investigate the effects of a community-based death education program for older adults. Methods: The study was conducted as a quasi-experimental study with a non-equivalent control group and pretest-posttest design. The subjects were community elders aged over 65 registered at a community health center and were convenience sampled. The experimental group consisted of 33 participants and the control group consisted of 32 participants. Experiments are conducted from June 18 to July 24, 2020. We tested our hypothesis using an independent t-test, and paired t-test. Results: The experimental group had significantly higher scores for psychological well-being than the control group after treatment (t=2.24, p=.028). In general attitude toward the use of life-sustaining technology, however, only the experimental group had a significant difference before and after the experiment with lower scores compared to the control group (t=-5.41, p<.001). Conclusion: We found that the community-based death education program developed in this study was partially effective in improving older adults' psychological well-being and general attitude toward the use of life-sustaining technology.

• Journal of Korean Neurosurgical Society
• /
• 제42권2호
• /
• pp.135-140
• /
• 2007

It is not the best way to treat a hopeless patient with life-sustaining medical devices until the heart beats stop. Advanced medical technology may prolong the life for a significant period without recovery from the disease. However, it would give an unbearable economic burden to the family and the society. In 2006, we decided not to operate 9 patients with traumatic intracranial hematomas. We examined those patients with special references to possible legal and ethical problems. It is reasonable to withhold a treatment after documentation that the family never wants any life sustaining treatment when the treatment does not guarantee the meaningful life.

• 예술인문사회 융합 멀티미디어 논문지
• /
• 제9권5호
• /
• pp.565-575
• /
• 2019

본 연구는 물리환경 및 미기후, 쾌적성이 외부활동 지속에 미치는 영향 도출을 목적으로 한다. 본 연구에서는 외부활동 지속에 영향을 미치는 요소로 도시 내 물리환경, 물리환경에 대해 외부공간 활동자가 느끼는 쾌적성, 미기후, 미기후에 대해 외부공간 활동자가 느끼는 쾌적성 등을 중심으로 접근했다. 이에 대한 분석을 위해서 2017년 중 봄, 여름, 겨울과 같이 세 계절에 대해서 외부공간 활동자가 느끼는 다양한 쾌적도에 대한 설문조사를 수행하였다. 설문조사 응답자가 설문조사에 응답하고 있는 동안에 주변 장소의 미기후에 대한 측정을 실시하였다. 이렇게 구축된 자료를 이용하여 효과적인 분석수행을 위해서 로짓회귀분석을 이용하였다. 분석결과, 물리환경 쾌적성의 용이성 및 안전성과 기후환경 쾌적성의 온도, 바람, 일사량 쾌적성 등은 외부공간의 활동 지속도와 유의미한 관계를 맺고 있었다. 머물기 및 대화 행위 보다는 걷기와 쇼핑 행위가 물리적 환경 및 기후환경에 보다 예민하게 영향을 받는 요소임을 도출했다.