• Korean Architects
• /
• no.7 s.363
• /
• pp.46-47
• /
• 1999

• Korean Architects
• /
• no.2 s.286
• /
• pp.20-45
• /
• 1993

• Proceedings of the KIPE Conference
• /
• 2011.07a
• /
• pp.573-574
• /
• 2011

본 논문에서는 DC-DC 컨버터의 설계 및 해석 방법을 PSpice와 Simulink를 이용한 Co-Simulation방법으로 제안하였다. 일반적인 회로 및 제어기 설계방식은 회로와 제어기를 각각 설계하여 시제품으로 측정하는 방법과 이상적인 모델을 이용하여 시뮬레이션 하는 방법을 사용한다. 본 논문에서는 상용 소자모델로 구성된 컨버터를 PSpice로 설계하였고, Simulink에서 PSpice Solver를 이용하여 시뮬레이션 함으로써 일반적인 설계 방식보다 높은 신뢰성을 가진 시뮬레이션 방법을 제안한다.

• Proceedings of the KIPE Conference
• /
• 2011.07a
• /
• pp.408-409
• /
• 2011

본 논문에서는 전력전자 시스템 해석 시 PSpice와 Simulink를 이용한 Co-Simulation방법으로 회로 레벨(Circuit level)을 포함한 시스템 레벨(System level)에서의 시뮬레이션 해석 방법을 제안한다. 일반적인 전력전자 시스템의 설계 방법은 회로 레벨과 시스템 레벨에서 별도로 시뮬레이션하거나 이상적인 모델을 이용하여 시스템을 해석하여 왔으나, 이러한 시스템 설계 방법은 별도의 시제품을 제작하여 측정함으로써 시간과 금전적 손실이 있었다. 이러한 점을 보완하기 위해서 PSpice와 Simulink를 이용한 Co-Simulation방법을 제안한다.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.13 no.6
• /
• pp.1330-1338
• /
• 1989

본 연구에서는 직각밀폐용기의 수평경계면이 단열인 경우뿐만 아니라 등온 조건을 갖는 경우에 대해 실험적으로 연구하여 경계조건의 변화가 직각밀폐용기내 흐름 및 열전달에 미치는 영향, 특히 등온조건을 갖는 경우 수직 온도차에 따르는 안정온도 구배효과로 예상되는 흐름의 억제, 지연효과를 작종 물리적 변수들의 영향과 함께 세밀히 조사하였다.

• Proceedings of the KIPE Conference
• /
• 2009.11a
• /
• pp.93-95
• /
• 2009

The synchronous PI current controller has been widely used for the high performance PM synchronous drives and generally implemented using a digital signal processor. This paper describes the control characteristics of the digital PI current controller for PM synchronous drives. The stability of the current control system considering the sampling time is investigated and the effects of the mismatched decoupling terms in the discrete-time domain are also discussed. The simulation results are provided to verify the theoretic results.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.3 no.5
• /
• pp.365-375
• /
• 1991

Confined natural convection due to lateral temperature difference in rectangular enclosures was studied numerically and experimentally for the insulated and the constant temperature enclosures. In the case of insulated enclosure, the flow pattern and heat transfer modes are rather simple depending mainly upon Rayleigh number. In the case of isothermal enclosure, however, the phenomena of flow and heat transfer are somewhat complex and interesting due to the stable thermal gradients and various circumstances resulted from four wall temperature conditions. As a dimensionless variable, to describe properly the flow and heat transfer phenomena in the isothermal enclosure, temperature difference ratio ${\Delta}T_v/{\Delta}T_H$ is newly introduced and this parameter seems to be appropriate in the analysis of results on the effect of stabilizing thermal gradient.

• Proceedings of the KIPE Conference
• /
• 2008.06a
• /
• pp.31-33
• /
• 2008

A novel lossless current sensing technique for a synchronous buck converter is presented. The inductor DCR method is generally used as a low cost and lossless current sensing technique of DC/DC converters. It is however difficult to obtain the accurate current value for the conventional DCR method because the inductor resistance varies depending on the operating frequency. In order to overcome this problem, an improved current sensing technique is proposed, which has the separated DC and AC sensing circuits. The concept and operation of the proposed method are explained and the experimental results are provided to show its effectiveness.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.12 no.1
• /
• pp.40-49
• /
• 2000

The flow and heat transfer characteristics of the exhaust airflow window system were studied numerically by a finite volume method. Attention was paid to see the decrease in indoor cooling load. The exhaust air flow rate, solar energy power and aspect ratio of window were considered as main variables. From the result of the comparison between the exhaust airflow window and the enclosed window, the indoor heat gain was reduced remarkably by 76%. It is also suggested that in the design of the exhaust airflow window optimum values of aspect ratio, H/W and exhaust air flow rate, Re were about 0.05 and 600, respectively.

• The Korean Journal of Emergency Medical Services
• /
• v.26 no.2
• /
• pp.19-35
• /
• 2022

Purpose: This study aimed to identify research topics in the emergency medical technician (EMT) field and examine research trends. Methods: In this study, 261 research papers published between January 2000 and May 2022 were collected, and EMT research topics and trends were analyzed using topic modeling techniques. This study used a text mining technique and was conducted using data collection flow, keyword preprocessing, and analysis. Keyword preprocessing and data analysis were done with the RStudio Version 4.0.0 program. Results: Keywords were derived through topic modeling analysis, and eight topics were ultimately identified: patient treatment, various roles, the performance of duties, cardiopulmonary resuscitation, triage systems, job stress, disaster management, and education programs. Conclusion: Based on the research results, it is believed that a study on the development and application of education programs that can successfully increase the emergency care capabilities of EMTs is needed.