탄소중립 시대의 가스 냉방 및 열 구동 냉방 시스템

박찬우 대한설비공학회 2022 설비저널 Vol.51 No.2

봉쇄와 교착이 존재하는 시스템의 성능분석을 위한 페트리-네트 기반 모의실험 소프트웨어 개발

박찬우,황상철,이효성 한국시뮬레이션학회 2000 한국시뮬레이션학회 논문지 Vol.9 No.1

In this paper, a new software package for modeling and simulating discrete-event dynamic systems is developed. The new software is a general-purpose, graphical tool based on timed Petri-nets and is developed using Visual Basic and Visual C++ for the window environment. It allows the user to graphically build a Petri-net model and enter input data for executing the Petri-net simulation model. It is equipped with a deadlock detection and recovery function as well as an automatic error check function. In addition, the software supports various enabling functions and distribution functions and provides various statistics for the performance measures of interests pertaining to the system. We expect the new software will be used in a wide number of applications including computer, communication and manufacturing systems.

A Study on the Propagation of Measurement Uncertainties into the Result on a Turbine Performance Test

박찬우,조수용 대한기계학회 2004 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.18 No.4

Uncertainties generated from the individual measured variables have an influence on the uncertainty of the experimental result through a data reduction equation. In this study, a performance test of a single stage axial type turbine is conducted, and total-to-total efficiencies are measured at the various off-design points in the low pressure and cold state. Based on an experimental apparatus, a data reduction equation for turbine efficiency is formulated and six measured variables are selected. Codes are written to calculate the efficiency, the uncertainty of the efficiency, and the sensitivity of the efficiency uncertainty by each of the measured quantities. The influence of each measured variable on the experimental result is figured out. Results show that the largest uncertainty magnification factor (UMF) value is obtained by the inlet total pressure among the six measured variables, and its value is always greater than one. The UMF values of the inlet total temperature, the torque, and the RPM are always one. The uncertainty percentage contribution (UPC) of the RPM shows the lowest influence on the uncertainty of the turbine efficiency, but the UPC of the torque has the largest influence to the result among the measured variables. These results are applied to find the correct direction for meeting an uncertainty requirement of the experimental result in the planning or development phase of experiment, and also to offer ideas for preparing a measurement system in the planning phase.

중소도시 대학병원에 내원한 알레르기 반응 환자의 임상 양상

박찬우,옥택근,조준휘,김성은,최기훈,배지훈,서정열,정재봉,안희철,안무업,조병렬,유기철 대한응급의학회 2004 大韓應急醫學會誌 Vol.15 No.6

P u r p o s e: Emergency department visits for acute allergic reactions are common. However, relatively little is known about the characteristics of patients who visit the emergency department for such reactions. We undertook this study to evaluate the frequency, the cause, the severity, the treatment and the prognosis of patients admitted for allergic reactions to a college hospital in a city. M e t h o d s: We studied 724 patients visiting two emergency departments of college hospitals during the years 2002- 2003. Clinical symptoms involved pruritus, dyspnea, hoarseness, nausea, vomiting, abdominal pain, diarrhea, dizziness, and seizure. Physical examinations involved vital signs, urticaria, rash, local edema, angioedema, rhinitis/conjunctivitis, wheezing, stridor, cyanosis, and laryngeal edema. We divided the causative agents into drugs, insects, foods, and others. We classified the treatments of the allergic reaction as antihistamines, corticosteroids, epinephrine, oxygen, and hydration. We divided patients into mild, moderate, and severe acute hypersensitivity groups. R e s u l t s: In order of frequency, clinical symptoms were pruritus (88.1%), urticaria (72.4%), rash (68.9%), local edema (11.7%), etc. The causative agents were foods (53.0%), unknown origin (29.1%), insects (11.0%), and drugs (6.8%). Antihistamine, corticosteroid, epinephrine were injected in 93.4%, 89.1%, 2.3% of the patients, respectively. The mild, moderate, and severe groups were 87%, 9.8%, and 3.2% of the patients, respectively. C o n c l u s i o n: For patients with allergic symptoms visiting to the university-affiliated teaching hospitals in a small city, foods were the major causative agent, but drugs and insects provoked more severe allergic reactions.

감사위원회

박찬우 연세대학교 법학연구원 2002 法學硏究 Vol.12 No.3

The Commercial Law of Korea recently adopted the systems of outside directors, committee in the board of directors including audit committee. So a corporation may have an audit committee in accordance with the articles of incorporation in place of auditors. In that case the corporation shall not appoint any auditors. Under the Securities and Exchange Act of Korea, large publicly held corporations should have an audit committee. The audit committee is the one under the board of directors. The change of auditing system following that of the United States of America is an important reform of the corporate goverance. The indepence of the audit committee from both executives and directors is a verry important premise for the success of the audit committee system. In order that an audit committee may work effectively, we need some more improvements. First, members of the audit committee have to be elected by the general meeting of shareholders. Second, the audit committee should operate in the way of supervisory meeting system. Third, the resolution of the audit committee must not be reversed by the board of directors. Finally, we have to arrange the responsibility of outside directors within reasonable extent 없음.

Cellulose nanofibril (CNF) 강화 바이오플라스틱 제조 및 응용

박찬우,한송이,박지수,이은아,박정윤,권구중,이승환 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

본 연구에서는 생분해성 바이오플라스틱인 thermoplastic starch (TPS)의 강화 필러로써 cellulose nanofibril (CNF)을 활용하였다. CNF 수현탁액에 옥수수 전분과 가소제(글리세롤, 솔비톨)를 첨가한 후, 80°C에서 1시간동안 젤라틴화하여 마스터배치를 제조하였다. 제조된 마스터배치를 180°C 이축압출기에서 용융 혼련하여 CNF 강화 TPS 복합재료를 제조하였다. CNF의 화학조성비 및 첨가비율에 따른 TPS 복합재료의 물성을 평가하였으며, 3D 프린팅 소재로써의 응용성을 평가하였다. ^** 이 연구는 2018년도 정부(교육부)의 재원으로 한국연구재단의 지원을 받아 수행된 기초연구사업임(No. 2018R1A6A1A03025582).

Alienor Method와 Radial Basis 함수를 이용한 전역적 최적화에 대한 연구

박찬우,천영성,서욱호 한국항공우주학회 2008 한국항공우주학회 학술발표회 논문집 Vol.- No.-

626년경의 삼국 분쟁과 당의 백제 인식

박찬우 한국사학회 2023 史學硏究 Vol.- No.149

그동안 삼국 분쟁의 격화와 당의 개입이라는 역사상은 640년대를 중심으로 논의되었다. 이는 신라와 당의 연합, 고구려·백제의 멸망과 연결된다는 점에서 한국 역사상 중대한 변곡점이라 할 수 있다. 그런데 626년경에도 삼국 분쟁에 당이 朱子奢를 파견하여 개입한 사건이 있었다. 이에 대해 대체로 당 고조대의 사건으로 보아왔지만, 이 글에서는 사료비판을 통해 당 태종이 朱子奢를 파견했음을 밝혀보았다. 아울러 주자사의 사행 목적은 회맹의 제안에 있었고, 그것이 627년 연말 당 조정에서 삼국 사신의 회합으로 실현되었다고 추론했다. 627년 회맹에서 당 태종이 주재하는 가운데 삼국은 장래의 화평을 약속했다. 백제 무왕은 사죄의 표문을 당에 보내기까지 했다. 그런데 백제는 627년 이후에도 신라 침공을 멈추지 않았다. 당의 입장에서 보면 백제는 ‘군신 간의 약속’을 어긴 셈이 된다. 이와 관련하여 640년대 이래의 사료를 보면 당의 백제에 대한 부정적 인식을 엿볼 수 있다. 백제가 원격지에 위치함을 믿고 약속을 쉽게 어긴다거나 겉과 속이 다르다는 것이었다. 이 글에서는 그러한 인식이 백제가 627년의 회맹에서의 약속을 파기한데서 비롯되었음을 지적해보았다. 당의 부정적 백제 인식은 640년대 이후 양국 관계의 악화와도 무관하지 않다. 620년대 중반의 삼국 분쟁과 회맹을 640년대 이후 역사상의 기점으로써 주목해볼 필요가 있다.

150 RT급 흡수식 열펌프용 고온재생기의 열전달 특성

박찬우,정종수 대한설비공학회 1999 설비공학 논문집 Vol.11 No.3

Experiments were carried out to study the heat transfer characteristics of a disrober for 150 RT LiBr-water absorption heat pump. An experimental apparatus was divided into four sections, a combustion chamber area, two bare-tube areas, and finally a finned-tube area to quantify the heat transfer rate of each section by measuring the generation rate of vapor. Dividing plates was installed at the upper inside part of deserter to prohibit the moving of vapor generated at heating tubes of a section to another section near. In the first bare-tube area, the generation rate of vapor was the largest among the four sections. The finned-tube area only contributed to give sensible heat increase of solution to the saturation temperature. The heat transfer area of the finned-tube area was 52.2%, which absorbed only 9.2% of the total heat from the combustion gas. On the contrary, the heat transfer area of the first bare-tube area was 16.6%, but it absorbed 52.4% of the total absorbed heat. The temperature of the solution at upper part at the finned-tube area was lower than that of the lower part, because weak solution came in upper part of the finned-tube area. But, this tendency was changed at the first and second bare-tube area due to the vigorous heat transfer and fluid flow enhanced by vapor generation through heating tubes. The overall heat transfer coefficient and heat flux were the largest at the first bare-tube area among the other sections.

난류 발생기의 형상에 따른 수직 PCB채널에서의 열전달 및 압력손실 변화

박찬우,장승일,정종수,남평우,Park, Chan-U,Jang, Seung-Il,Jeong, Jong-Su,Nam, Pyeong-U 대한기계학회 1996 大韓機械學會論文集B Vol.20 No.7

This study was performed to analyze the cooling effect of heated ribs which are frequently used for cooling of electronic parts, using the numerical method. To prevent the excessive pressure drop due to turbulence promoters for the enhancement of heat transfer rate especially, the effect of the angle of turbulence promoter was investigated by the numerical analysis. Heat transfer rate with turbulence promoters with rectangular cross-section increased by 13% in average, but the coefficient of pressure drop increased by 1.68 times than that without them. In the present study, triangular cross-sectional shape turbulence promoters were suggested and numerically tested. Pressure drop of turbulence promoter with the 30 degree triangular cross-sectional shape decreased by 30% from that of rectangular cross-section promoters while heat transfer rate was almost the same. While with 4 turbulence promoters, the heat transfer rate increased by 21%, the pressure drop increased 4 times. It means that the higher capacity of cooling fan should be needed. With the triangular cross-sectional shape, the size of vortex region at the rear of promoters became considerably smaller, so pressure drop became smaller. The effect of the change of cross-sectional shape was not found in the flow pattern near the ribs, so that heat transfer characteristics in the ribs were not changed.