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.

온실가스 배출규제와 기업전략

박찬우,Park, Chan-U 환경보전협회 2008 환경정보 Vol.30 No.375

5세기 삼국의 대외 위기의식과 전쟁 -평양 천도에서 한성 함락까지-

박찬우(Park, Chan-U) 한국고대사학회 2023 韓國古代史硏究 Vol.- No.112

In Korean history, the 5th century is represented as Goguryeo’s southward movement, especially the relocation of the capital to Pyongyang in 427 and the fall of Hanseong and the relocation of the capital to Ungjin in 475 are major events symbolizing Goguryeo’s southward movement. The general understanding of the historical image of the 5th century was that “the southward movement of Goguryeo” symbolized by the relocation of the capital to Pyongyang and “the passive Baekje and Silla”. However, a close examination of historical materials shows that Goguryeo’s unilateral attacks are not noticeable during that period. There were signs of a two-way war, such as a pre-emptive strike by Baekje and Silla, and Goguryeo’s attack was rather passive. Eventually, Goguryeo abandoned its long-standing policy of maintaining the status quo since King Kwanggaeto and raided and fell Hanseong of Baekje. In this paper, the Three Kingdoms explained these aggressive actions against the strong of the relatively weak and the motivation for breaking the status quo with a sense of external crisis or fear. This paper explains these aggressive actions against the strong of the relatively weak and the motivation for breaking the status quo with sense of external crisis or fear that each of the Three Kingdoms had.

640년대 전반 ‘麗濟連和’의 실상과 唐의 백제 인식

박찬우(Park, Chan-U) 한국사학회 2021 史學硏究 Vol.- No.141

7세기 전반 한반도를 둘러싼 국제관계는 흔히 동서연합(신라‧당) 對남북연합(고구려‧백제)의 구도로 설명되었다. 이에 따라 백제와 당의 관계가 신라와 당의 관계보다 밀접하지 않다거나 또 ‘麗濟連和’가 오랜 기간 지속되었다는 등의 역사상이 구축되었다. 그러나 이에 대해서는 신라사신의 ‘麗濟連和’에 대한 ‘주장’과 ‘실제’를 분리해서 보아야 한다는 반론도 제기된 바 있다. 이 글은 이러한 비판적 사료 연구를 계승‧발전시켜 640년대 전반 ‘麗濟連和’의 실체가 사료적으로 명확히 뒷받침되지 않음을 논하였다. 한편 근래에는 백제와 당의 관계가 630년대 이래 645년 이전까지는 대체로 우호적이었다고 보고 있다. 다만 표면적 우호관계에만 주목할 경우, 643년 9월 신라 遣唐使의 ‘麗濟連和’ 주장을 기점으로 당과 백제의 관계가 급격히 악화된 상황을 쉽게 설명하기 어렵다. 이 점의 해명을 위해 과거 高隋戰爭때 백제가 보인 이중적 태도, 620년대 당의 중재 후에도 지속된 백제의 신라 공격 등을 배경으로 하여, 당이 한편으로는 백제에 대한 부정적 인식도 견지하고 있었음을 논하였다. In the first half of the 7th century, international relations on the Korean Peninsula were often explained in the composition of East-West Union(Silla&Tang) vs. North-South Union(Goguryeo&Baekje). Therefore, scholars have suggested that the relationship between Baekje and Tang was not as close as that between Silla and Tang, and the Goguryeo–Baekje alliance lasted for a long time. However, some objections were raised to the view that the claims of Silla’s envoy should be separated from the actual situation. Based on such critical research, this paper revealed that the reality of the Goguryeo–Baekje alliance in the early 640s was lacking in historical evidence. On the other hand, some recent papers consider that the relationship between Baekje and Tang was generally friendly from the 630s until before 645. However, if we focus only on superficial relations, we cannot explain the situation where relations between Tang and Baekje deteriorated rapidly due to the Silla mission to Tang in September 643. Accordingly, based on Baekje’s uncooperative attitude during the Goguryeo and Sui wars and the fact that Baekje continued to attack Silla in the 620s despite Tang’s intervention, this paper revealed that Tang had a negative perception of Baekje.

『我邦疆域考』 역주·비평 (2) -四郡總考・樂浪考-

박대재(Park, Dae-Jae),박찬우(Park, Chan-U) 고려사학회 2020 한국사학보 Vol.- No.79

정약용은 『아방강역고』 四郡總考에서 위만조선 멸망 이후 설치된 漢四郡의 지역범위에 관해 江界外徼에 있던 진번군을 제외하고는 대부분 압록강 동쪽 지역에 해당한다고 본 뒤 4군이 2府로 전환한 과정을 살펴보았다. 이어서 樂浪考에서는 前漢, 後漢, 晉 시기 낙랑군의 연혁을 살펴보고 주요 속현의 위치를 비정하였다. 하지만 2府를 설정하는 문제나 낙랑군 東部都尉 및 南部都尉의 관할 지역에 관한 이해, 遂成縣의 위치 비정 등은 조선 후기 다른 역사지리서나 현재의 통설과 크게 차이가 나는 부분이라 지적할 수 있다. In “Sagunch"onggo(四郡總考 The General Review of the Four Commanderies)” of Abang Kangyŏkko(我邦疆域考), Chŏng Yagyong (丁若鏞) studied the process of the four commanderies’ administrative transformation into two prefectures(府), under the assumption that the commanderies were located in the eastern region of Amnok River except Zhenfan Commandery. Meanwhile, he demonstrated the history of Lelang Commandery and estimated the location of its counties during the periods of Former Han, Later Han and Jin Dynasty. Yet, it is noteworthy that his arguments about the two prefectures, the Lelang commandery’s Eastern and Southern Part Districts, the location of Suichen County(遂成縣), and other arguments were significantly different from the general opinions held by scholars after the later period of Chosŏn dynasty.

대한산업보건협회 산업보건연구소의 미국 정도관리 참여결과

이선주,최호춘,박찬우,오미순,이준승,전수경,박화미,정규철,Lee, Seon-Ju,Choe, Ho-Chun,Park, Chan-U,O, Mi-Sun,Lee, Jun-Seung,Jeon, Su-Gyeong,Park, Hwa-Mi,Jeong, Gyu-Cheol 대한산업보건협회 1995 산업보건 Vol.88 No.-

PAT program(The Proficiency Analytical Testing Program)은 미국산업위생협회(American Industrial Hygiene Association AIHA)와 미국산업안전보건연구원(National Institute for Occupational Safety and Health NIOSH)에서 공동주관하는 정도관리로서 일년에 4회 실시하고 있다. 실시항목은 금속(납, 카드뮴, 크롬, 아연), 유리규산, 석면, 유기,용제(Benzen, O-Xylene, Toluene, Carbon Tetrachloride, 1, 1, 1-Trichloroethane, Chloroform, Tetrachloroethylene, 1, 2-Dichloroethane, methanol, p-Dioxane)이다. 대한산업보건협회 산업보건연구소에서는 위의 4가지 항목을 모두 신청하여 1995년 1월에 실시된 120회 부터 참여하였는데 다음은 본 연구소의 120화에 대한 분석방법과 NIOSH로 부터 받은 결과이다.

흡수기 용액 재순환이 흡수식 냉동기 성능에 미치는 영향

정종수,진성민,박찬우,최승학,정봉철,Jeong, Jong-Su,Jin, Seong-Min,Park, Chan-U,Choe, Seung-Hak,Jeong, Bong-Cheol 대한기계학회 2002 大韓機械學會論文集B Vol.26 No.5

If a part of the poor solution from the absorber outlet is recirculated to the absorber inlet, the solution temperature at the solution spray pump can be reduced, and the solution flow rate in the absorber is increased. We have performed the experiments on the influences of the absorption chiller performance according to the ratio of the recirculation, defined as the ratio of the recirculation flow rate to the total solution flow rate at the absorber outlet. As increasing the ratio of the recirculation, the absorption capacity of the solution can be deteriorated. On the other hand, due to the increasing flow rate, the heat transfer rate can be enhanced. As a result, the performance of the absorber and the cooling capacity of the absorption chiller have nothing to do with the recirculation ratio, and the lifetime of the spray pump will be maintained.

패키지된 실리콘-게르마늄 이종접합 바이폴라 트랜지스터의 콜렉터 형성 조건에 따른 전기적 특성

이승윤,이상흥,김홍승,박찬우,김상훈,이자열,심규환,강진영,Lee, Seung-Yun,Lee, Sang-Heung,Kim, Hong-Seung,Park, Chan-U,Kim, Sang-Hun,Lee, Ja-Yeol,Sim, Gyu-Hwan,Gang, Jin-Yeong 한국재료학회 2002 한국재료학회지 Vol.12 No.6

The effects of the conditions of the collector formation on electrical characteristics of the packaged SiGe hetero-junction bipolar transistors (HBT) were investigated. While the DC characteristics of SiGe HBTs such as IV characteristic, forward current gain, Early voltage, and breakdown voltage were hardly changed after packaging, the AC characteristics such as $f_{\tau}\; and\; f_{max}$ were degraded severely. With the rise of the collector concentration, the break-down voltage decreased but the $f_{\tau}$ increased. Additionally, $\beta$ and $f_{\tau}$ values were kept high in the range of elevated collector current due to the increase of the critical current density for the onset of the Kirk effect. The devices As implanted before the collector deposition showed lower breakdown voltage and higher $f_{\tau}$ than the others, which seems to be originated from the As up-diffusion resulting in the thinner collector.

보조생식술에서 저용량 Aspirin과 Prednisolone 병합투여의 효용성

허걸 ( Heo Geol ),박찬우 ( Park Chan U ),김혜옥 ( Kim Hye Og ),김진영 ( Kim Jin Yeong ),양광문 ( Yang Gwang Mun ),궁미경 ( Gung Mi Gyeong ),강인수 ( Kang In Su ) 대한산부인과학회 2003 Obstetrics & Gynecology Science Vol.46 No.9

Objective : To estimate the efficacy of low-dose aspirin and prednisolone supplementation in women undergoing controlled ovarian hyperstimulation (COH) for in vitro fertilization and embryo transfer (IVF-ET). Methods : From 1 July 2001 to 31 July 2002, A