Alloy 600 노즐관통부의 이종금속용접 잔류응력에 따른 응력부식균열 거동 분석

김성우,김홍표,김동진,정재욱,장윤석,Kim, Sung-Woo,Kim, Hong-Pyo,Kim, Dong-Jin,Jeong, Jae-Uk,Chang, Yoon-Suk 한국압력기기공학회 2010 한국압력기기공학회 논문집 Vol.6 No.2

This work is concerned with the analysis of stress corrosion cracking(SCC) behavior of Alloy 600 nozzle penetration mock-up according to a residual stress induced by a dissimilar metal welding(DMW) in a nuclear reactor pressure vessel. The effects of the dimension and materials of the nozzle penetration on the deformation and the residual stress induced by DMW were investigated using a finite element analysis(FEA). The inner diameter(ID) change of the nozzle by DMW and its dependance on the design variables, calculated by FEA, were well consistent with those measured from the mock-up. Accelerated SCC tests were performed for three mock-ups with different wall thicknesses in a highly acidic solution to investigate mainly the effect of the residual stress on the SCC behavior of Alloy 600 nozzle. From a destructive examination of the mock-up after the tests, the SCC behavior of the nozzle was fairly related with the residual stress induced by DMW : axial cracks were found in the ID surface of the nozzle within the J-weld region where the highest tensile hoop stress was predicted by FEA, while circumferential cracks were observed beyond both J-weld root and toe where the highest tensile axial stress was expected.

방향성이 높은 사운드 빔 형성 알고리즘

김성우,허유미,박영철,윤대희,Kim, Seona-Woo,Hur, Yoo-Mi,Park, Young-Chul,Youn, Dae-Hee 한국음향학회 2010 韓國音響學會誌 Vol.29 No.1

본 논문에서는 스피커 어레이를 사용하여 높은 방향성을 가진 사운드 빔을 형성하는 알고리즘을 제안하고, 제안된 알고리즘을 멀티 채널 3D사운드 시스템에 적용하는 방법을 설명한다. 제안된 알고리즘은 두 과정을 거친다. 첫 번째 과정에서는 표적 지점과 제어 영역간의 음향 파워 비를 최대화 하는 최적 빔 형성 계수를 구하고, 다음 과정에서는 상관행렬을 조절해 가면서 사운드 빔의 방향성을 반복적으로 향상시킨다. 여러 가지 상황에서 제안된 알고리즘의 성능을 평가하였으며, 실험 결과는 제안된 알고리즘이 기존의 방법들에 비해 더 높은 방향성을 갖는 사운드 빔을 제공함을 보였다. This paper proposes a technique of sound beamforming that can generate high-directive sound beams, and this paper also presents applications of the proposed algorithm to multi-channel 3D sound systems. The proposed algorithm consists of two phases: first, optimum weights maximizing a sound pressure level ratio between the target and control acoustic regions are designed, and later, the directivity of the pre-designed sound beam is iteratively enhanced by modifying the covariance matrix. The proposed method was evaluated under various situations, and the results showed that it could provide more focused sound beams than the conventional methods.

미국의 패권전략과 한국 군사전략 발전방향

김성우,Kim, Sung-Woo 대전대학교 군사연구원 2010 군사학연구 Vol.8 No.-

This thesis is to make an appropriate national defense policy of Republic of Korea through studying the Hegemony Strategy of United States. I searched the theory of hegemony. The hegemony was differently defined by the point of time and region. The strong power nations with the hegemony have been making efforts to maintain their hegemony everytime. I have conclusion that the presence of hegemony once emerged, it brought regional stability in place whether it is coercive or beneficial. The stability and instability of international order IS not exclusively dependent on hegemony. Even if the safety of hegemony cannot guarantee absolute stability of international order, there IS on doubt that the hegemony has enormous impact on that. According to the hegemonic theory, the history of mankind equals to the history of rising and falling hegemony. The international order was changed as the hegemony changes. The United States has been making efforts to maintain her global hegemony during the post cold-war era as well. Taking all these into consideration, relevant military strategy direction able to pursue national interest is that to make up for the relative weakness in the strategic environment. South Korea have to prepare security policy response as following. First, South Korea should build the military force equipped with advanced weapons in military technology sector and solidify military diplomatic relation able to form cooperative relation in wartime. Second, South Korea should make solid Alliance of Korea and U.S. Third, develop and maintain multilateral security cooperation of East Asia. Forth, we could realize that there are means that can neutralize opponent's strong point by seeking one or two and more asymmetry in the aspect of strategy, tactics, and means through asymmetric strategy. Than the military force of South Korea should develop into a force that is able to overcome to the traditional North Korea's threat and new type of conflicts. And the force should have sufficient strength and be deployed to effectively defend the Korean Peninsula. So, we need to establish a denial and defense system against any hostile neighboring country. Therefore, ROK military forces preparing for the future should try to construct a future military power to gradually establish enough strength for self-defense to prepare for a uncertain security environment and when the Korean Peninsula is unified in a future.

Measurement of Electron Beam Output for the Prototype Compact Linac

김성우,강상구,이동주,임희진,이만우,이준규,이무진,양광모,노태익,정동혁,Kim, Sung-Woo,Kang, Sang Koo,Rhee, Dong Joo,Lim, Heuijin,Lee, Manwoo,Yi, Jungyu,Lee, Mujin,Yang, Kwangmo,Ro, Tae Ik,Jeong, Dong Hyeok Korean Society of Medical Physics 2015 의학물리 Vol.26 No.1

The C-band compact linear accelerator (linac) is being developed at Dongnam Institute of radiological & Medical Sciences (DIRAMS) for medical and industrial applications. This paper was focused on the output measurement of the electron beam generated from the prototype electron linac. The dose rate was measured in unit of cGy/min per unit pulse frequency according to the IAEA TRS-398 protocol. Exradin-A10 Markus type plane parallel chamber used for the measurement was calibrated in terms of dose to water at the reference depth in water. The beam quality index ($R_{50}$) was determined by the radiochromic film with a solid water phantom approximately due to low energy electrons. As a result, the determined electron beam output was $17.0cGy/(min{\cdot}Hz$. The results were used to monitor the accelerator performance during the development procedure. 의료용 및 산업용으로 활용하기 위한 C-밴드형 콤팩트 선형가속기의 개발이 동남권원자력의학원에서 진행되고 있다. 본 논문에서는 선형가속기 시작품에서 발생한 전자빔의 출력 측정 결과를 보고하고자 한다. 출력 측정은 물흡수선량에 대해 교정된 Exradin-A10 마커스형 평행평판형 전리함을 사용하여 물속 기준 깊이에서 IAEA TRS-398 프로토콜에 따라 흡수선량율을 결정하는 과정으로 진행되었다. 전자선 에너지가 낮은 점으로 인하여 선질지표($R_{50}$)은 필름 측정법을 써서 근사적으로 결정하였다. 결과로서 단위 펄스 진동수당의 선형가속기 전자빔의 출력은 $17.0cGy/(min{\cdot}Hz$로 나타났다. 본 연구의 결과는 개발 중인 전자가속기의 성능 평가 자료로 활용될 것이다.

비대칭전 주요사례 연구

김성우,Kim, Sung Woo 한국융합보안학회 2016 융합보안 논문지 Vol.16 No.6

비대칭전은 상대방이 효과적으로 대응할 수 없도록 상대방과 다른 성격 및 기능을 가진 수단과 방법으로 수행하는 작전이며 '이질성'과 '우월성'을 원칙으로 한다. 여기서 '이질성'이라 함은 적이 보유하고 있지 않거나 개발하지 못한 무기체계를 운용하여 적의 취약분야를 공격하거나 적의 능력을 파괴하는 것이며, '우월성'은 적보다 양적 질적 측면에서 압도하는 능력으로 대응하는 것이다. 비대칭 전략의 유형은 복잡하기 때문에 다양한 비대칭 전략의 유형분류가 가능하다. 따라서 비대칭전에 대한 여러 측면에서의 이해가 요구된다. 비대칭전의 관점에서 본다면, 고대전투에서 현대전에 이르기까지 혁신적인 방법과 전략 전술로 적을 격멸한 사례들은 비대칭전의 사례로 볼 수 있다. 전투에서 승리한 핵심요인에는 비대칭 전략 및 수단의 차별적 우월성이 반드시 존재했고 앞으로도 이러한 현상은 지속될 것이다. 한 때 창출된 비대칭은 시간이 경과함에 따라 상대편이 모방적으로 적응하여 비대칭이 소멸된다. 현대전에서 전략적 전술적 비대칭의 우위를 확보하려면 새로운 비대칭 전에 대하여 연구하고 상대방의 전략과 전술에 대응하는 방책개발을 계속해야 한다. We can not respond asymmetric warfare effectively. The asymmetric operation is performed in asymmetric methods and means with different characteristics and functions to their enemy. And the character of the asymmetric operation have 'heterogeneity' and 'superiority' in principle. The type of asymmetric strategy is complex and diverse. Since we can classify the type of the asymmetric strategy in many different way and we must study in many ways and aspects. When we study asymmetric war previous cases from modern to ancient era, we can find that the key factors of the victory have superiority of the asymmetric strategy and discriminatory measures. The asymmetry is created when one party has to adapt to the strategic environment. If we want to secure a strategic advantage, we must take a number of case studies and countermeasures for asymmetric warfare.

호남지방 전통주택에서의 규모와 평면형식 -전남 장흥군 관산읍 방촌만을을 중심으로-

김성우,이소연,Kim, Sung-Woo,Lee, So-Yeon 한국건축역사학회 1993 건축역사연구 Vol.2 No.2

The plan of Korean traditional houses are devided by the span-units which is the automatic result of the timber construction. This study aims to analyze the ways plan type change when the number of span changes. One village named Bangchon in Honan Province was selected where we investigated more than 30 houses ranging from 3 span to 6 span. It is identified that there were certain rules which govern the plan change when number of span change. When one span is added onto 3 span houses, wooden floor of one span is added in between the two ondol-rooms. When one span is added onto 4 span houses, kitchen is enlarged. When one span is added onto 5 span houses, wooden floor is enlarged into 2 span, Also the plan of Man's quarter(Sarang-chae) was investigated and compared to Lady's quarter. The research proves that such rules of plan change need to be considered as a basic standard of analysis when traditional houses are to be studied.

Mo/SiO₂ 촉매상에서 t-Butyl hydroperoxide에 의한 염화알릴의 에폭시화반응에 관한 속도론적 연구

김성우,박대원,정종식,박대철,Kim, Sung-Woo,Park, Dae-Won,Chung, Jong-Shik,Park, Dae-Chul 한국공업화학회 1992 공업화학 Vol.3 No.4

The synthesis of epichlorohydrin was carried out by the epoxidation of allyl chloride with tert-butyl hydroperoxide(TBHP) over silica supported molybdenum catalyst. Kinetic study was performed at $60-80^{\circ}C$ and 10 atm with the molar ratio of TBHP/Allyl chloride between 0.01 and 0.1 in a batch reactor. The epoxidation of allyl chloride was inhibited by tert-butyl alcohol and kinetic data could be represented by Michaelis-Meten type rate equation. The reaction mechanism could be explained by the combination of reversible adsorption of TBHP and tert-butyl alcohol accompanied by reaction of allyl chloride with TBHP adsorbed on $Mo/SiO_2$ catalyst. t-Butyl hydroperoxide(TBHP)에 의한 염화알릴의 에폭시화에 의해서 에피클로로히드린을 합성하는데 실리카에 담지된 몰리브데늄 촉매를 사용하였다. 속도론적 연구는 회분 반응기를 사용하여 $60-80^{\circ}C$, 10기압에서 TBHP/염화알릴의 농도비를 0.01-0.1의 범위내에서 수행하였다. t-butyl alcohol(TBA)에 의해서 염화알릴의 에폭시화 반응이 억제되었고, 반응속도는 Michaelis-Menten 형태의 속도식으로 표현할 수 있었다. 반응기구는 TBHP와 TBA의 가역흡착과 $Mo/SiO_2$에 흡착된 TBHP와 염화알릴의 표면반응으로 설명할 수 있었다.

망막분지정맥폐쇄에서 황반중심부의 후유리체박리가 황반부종에 미치는 영향

김성우,오인경,오재령,허걸,Seong Woo Kim,In Kyung Oh,Jae Ryung Oh,Kuhl Huh 대한안과학회 2006 대한안과학회지 Vol.47 No.3

Purpose: To quantitatively compare the role of posterior vitreous detachment in macular edema associated with branch retinal vein occlusion (BRVO) using OCT. Methods: A retrospective study of 36 eyes with BRVO-associated macular edema was carried out from November 2003 to February 2005. There was posterior vitreous detachment (PVD) in 23 eyes [PVD (+) group], and vitreoretinal attachment on the fovea in 31 eyes [PVD (-) group]. PVD was detected with an indirect ophthalmoscope or 90D lens. The foveal thicknesses of the two groups were measured and compared. Results: The mean foveal thicknesses of the PVD (-) and PVD (+) groups were 398.0±217.2 ?m and 233.6±80.6 ?m, respectively (p=0.000, Mann-Whitney test). The mean BCVA (log MAR) was 0.77±0.52 in the PVD (-) group and 0.40±0.37 in the PVD (+) group (p=0.002, Mann-Whitney test). Conclusions: The extent of macular edema associated with BRVO was significantly less in the PVD(+) group and BCVA was significantly better in the PVD (+) group as well.

Mo / SiO2 촉매상에서 t - Butyl hydroperoxide 에 의한 염화알릴의 에폭시화반응에 관한 속도론적 연구

김성우,박대원,정종식,박대철 ( Sung Woo Kim,Dae Won Park,Jong Shik Chung,Dae Chul Park ) 한국공업화학회 1992 공업화학 Vol.3 No.4

t-Butyl hydroperoxide(TBHP)에 의한 염화알릴의 에폭시화에 의해서 에피클로로히드린을 합성하는데 실리카에 담지된 몰리브데늄 촉매를 사용하였다. 속도론적 연구는 회분 반응기를 사용하여 60-80℃, 10기압에서 TBHP/염화알릴의 농도비를 0.01-0.1의 범위내에서 수행하였다. t-butyl alcohol(TBA)에 의해서 염화알릴의 에폭시화 반응이 억제되었고 반응속도는 Michaelis-Menten 형태의 속도식으로 표현할 수 있었다. 반응기구는 TBHP와 TBA의 가역흡착과 Mo/SiO_2에 흡착된 TBHP와 염화알릴의 표면반응으로 설명할 수 있었다. The synthesis of epichlorohydrin was carried out by the epoxidation of allyl chloride with tert-butyl hydroperoxide(TBHP) over silica supported molybdenum catalyst. Kinetic study was performed at 60-80℃ and 10 atm with the molar ratio of TBHP/Allyl chloride between 0.01 and 0.1 in a batch reactor. The epoxidation of allyl chloride was inhibited by tert-butyl alcohol and kinetic data could be represented by Michaelis-Meten type rate equation. The reaction mechanism could be explained by the combination of reversible adsorption of TBHP and tert-butyl alcohol accompanied by reaction of allyl chloride with TBHP adsorbed on Mo/SiO_2 catalyst.

방광에 발생한 평활근종의 초음파, CT, MRI 소견: 증례 보고

김성우,Kim, Seong-U 대한영상의학회 2004 대한영상의학회지 Vol.50 No.3

평활근종은 비뇨생식기의 어느 곳에도 생길 수 있다. 자궁에 가장 흔한 종양이기도 하지만 매우 드물게 방광에서 기원하기도 한다. 저자들은 방광에 생긴 평활근종의 초음파, CT, MRI 소견 1예를 경험하였기에 이를 보고하고자 한다. Leiomyomas are the most common benign tumors of the uterus, and although they can occur at any site in the genitourinary tract, they very rarely originate from the urinary bladder. We report a case in which a leiomyoma occurred at that site, deseribing the US, CT, and MRI findings.