선박용 고강도 Al합금(5456-H116)의 최적 방식 전위결정에 관한 연구

김성종,고재용,Kim Sung-Jong,Ko Jae-Yong 한국마린엔지니어링학회 2006 한국마린엔지니어링학회지 Vol.30 No.1

Recently, interest in using Al alloys in ship construction instead of fiber-reinforced plastic (FRP) has increased because of the advantages of A) alloy ships over FRP ships, including high speed, increased load capacity. and ease of recycling. This paper investigated the mechanical and electrochemical properties of Al alloys in a slow strain rate test under various potential conditions. These results will provide reference data for ship design by determining the optimum protection potential regarding hydrogen embrittlement and stress corrosion cracking. In general, Al and Al alloys do not corrode on formation of a film that has resistance to corrosion in neutral solutions. In seawater, however, $Cl^-$ ions lead to the formation and destruction of a Passive film. In a potentiostatic experiment. the current density after 1200 sec in the Potential range of $-0.68\~-1.5\;V$ was low. This low current density indicates the protection potential range. Elongation at an applied potential of 0 V was high in this SSRT. However, corrosion protection under these conditions is impossible because the mechanical properties are worse owing to decreased strength resulting from the active dissolution reaction in parallel parts of the specimen. A film composed of $CaCO_3\;and\;Mg(OH)_2$ confers corrosion resistance. However, at potentials below -1.6 V forms non-uniform electrodeposition coating, since there is too little time to form a coating. Therefore, we concluded that the mechanical properties are poor because the effect of hydrogen gas generation exceeds that of electrodeposition. Comparison of the maximum tensile strength, elongation, and time to fracture indicated that the optimum protection potential range was from -1.45 to -0.9 V (SSCE).

고성능 씰리스 실린더의 해석 및 누설유량 시험

김성종(Kim sung-jong),김동수(Kim dong-soo),이승현(Lee seung-hyun) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.4

The cylinder without seal has a piston with air bearing which is partly cylindrical and conical shape. The description of system geometry is deviation by the flow rate equation. Then pressure distribution and bearing force equations are derived. Several non-dimensional parameters are suggested. The relationship among bearing force, leakage flow and geometry of the bearing is investigated by simulation. And determination method for optimal design of sealless cylinder is given. A prototype of sealless cylinder which had rod bearing with four pockets, five pockets, and six pockets was built respectively. As a result of leakage flow test, it is evaluation to air bearing in sealless cylinder.

복숭아 우산식 지주시설 설치로 작업노력 절감

김성종(Sung Jong Kim),류명상(Myeong Sang Ryu) 한국원예학회 2009 한국원예학회 학술발표요지 Vol.2009 No.5

F10/F12 분기기에서의 가드레일 길이 변화에 따른 주행안전성 해석

김성종(Sung Jong Kim),엄범규(Beom Gyu Eom),이희성(Hi Sung Lee) 대한기계학회 2012 대한기계학회 춘추학술대회 Vol.2012 No.4

기존선에서의 속도향상을 저해하는 요인은 매우 다양하지만, 그 중 분기기 통과속도 제한규정을 가장 대표적 사례로 손꼽히고 있다. 현재, 기존선 분기기의 직선측 최고 통과속도는 일반 선로의 차량 최고 주행속도에 비하여 낮은 속도로 제한되어 운행하고 있으며 분기기내에서 주행속도를 제한하는 것은 분기기 통과시 철도차량의 주행안정성을 확보하는데 목적을 두고 있다. 본 연구에서는 대구도시철도공사의 분기기 가드레일에 대한 형상 변경사례를 기반으로 하여, 분기기에서의 차륜/레일 형상에 따른 기하학적 접촉 특성을 이론적으로 검토하였으며, 개발한 VI-Rail 분기기 해석기법을 통하여 F10/F12 분기기에서의 가드레일 길이 변화에 따른 주행안정성 해석을 수행하여 그에 따른 영향을 살펴보았다. The speed-limit regulation on the turnout is the main cause which hinders the speed-up of conventional lines among many factors. The specification speed for the train which passes the turnout system is lower than that on the general track. And this is for securing running safety of railway vehicle passing through turnout. In this paper, shape change example for guard rail component of turnout in Daegu Metropolitan Transit Corporation(DTRO) was studied. Theoretical examination on the geometrical contact characteristics according to wheel/rail shape at turnout was carried out. And the running safety analysis by changing length of guard rail on F10/F12 turnout using the developed analysis techniques (by VI-Rail) was achieved and the effect on the railway safety was examined accordingly.

열충격을 받은 Graphite 재료의 열응력 해석

김성종(Sung-Jong Kim),이영신(Young-Shin Lee),김재훈(Jae-Hoon Kim),구송회(Song-Hoe Koo) 대한기계학회 2002 대한기계학회 춘추학술대회 Vol.2002 No.5

Graphite is a good conductor of electricity and a superior refractory, it has high thermal conductivity,<br/> high thermal shock resistance, excellent high temperature strength, excellent machinability, and a low modulus of elasticity. It is most expected to apply to rocket nozzle and spaceship etc. which is used under severe temperature conditions. However, thermal shock resistance and strength of graphite on high temperature have not been evaluated yet. In this study, the transient heat conduction and thermal stress analysis are performed through use of the finite element method with nonlinear code MSC.Marc. The thermal-mechanical analysis carried out, and the temperature and thermal stress contour of graphite are investigated. This result will be taken advantage of assist data for thermal shock experiment.

북한 이탈 주민 정착지원을 위한 협력적 거버넌스 구축

김성종(Sung-Jong Kim) 한국콘텐츠학회 2012 한국콘텐츠학회논문지 Vol.12 No.2

본 연구는 탈북자 정착지원 협력적 거버넌스 구축을 위한 참여주체인 중앙정부, 지방자치단체, 민간단체의 구체적 역할을 논의하기 위해 수행되었다. 중앙정부는 현재 통일부, 행정안전부, 고용노동부, 교육과학기술부, 보건복지부 등 다양한 차원에서 수행되고 있는 기능에 대한 정책조정 기능이 취약하므로 총괄 부서를 지명하고 정책기획, 예산확보 및 배정, 사후평가 및 책임성확보를 담당해야 한다. 지방자치단체는 실질적 서비스를 전달하기 위한 네트워크를 구축하고 관리하는 기능을 담당하기 위해서 의사소통 체널을 확보하고 관계망을 형성하며 다양한 주체들의 집행업무를 조정하는 역할을 담당해야 한다. 민간단체는 전문성을 바탕으로 서비스 개발하고 지역의 자원을 발굴하며 밀착서비스 제공하는 것이 바람직할 것이다. This study was conducted to establish collaborative governance for North Korean Refugees’ settlement support service. Three major actors were identified. At the central government level, there is no control center to coordinate various functions. This study suggested three roles for central government in collborative governance, which are policy planning based on public value, allocating financial resources to implementing organizations, and program evaluation for securing public accountability. The rloes of local government are establishing communication channels between implementing participants, maintenancing good relations, and coordination. Finally, the role of private actors is developing high quality service programs, connecting local resources for settlement service.

복숭아 발육과정 중 품종별 당조성과 관련효소 활성의 변화

김성종(Sung Jong Kim),박혜영(Hye Young Park) 한국원예학회 2007 원예과학기술지 Vol.25 No.3

본 연구는 복숭아 주요 품종의 발육단계별 과실 생장 및 당대사 특성을 밝히고, 품종별 당조성과 당대사 관련 효소 활성의 변화와 이들의 상관을 구명하여 복숭아 과실의 당대사 기작을 밝히고자 하였다. 수확시기가 다른 복숭아의 4가지 품종의 종횡경 비(ℓ/D ratio), 전분함량과 산도는 시간의 경과에 따라서 감소하는 경향을 나타냈으며 이와는 반대로 당도와 총 수용성 당 함량은 수확기까지 계속 증가하는 경향을 나타냈다. 또한 생육 초기에 포도당과 과당이 높게 나타났으나 성숙기에 자당함량이 크게 증가하여 수확기의 중요한 당 조성 성분은 자당으로 나타났다. 복숭아 과실의 당 축적은 자당 합성효소와 자당 분해효소에 의하여 큰 영향을 받았으나 자당 인산화합성효소나 소르비톨 산화효소의 활성은 전 생육기간동안 전반적으로 낮은 활성을 나타냈다. 총 전분과 총 수용성 당은 부의 상관을 나타냈고, 당도와 총 수용성 당은 정의 상관을 나타냈다. 그러나 각 수용성 당과 당도의 상관은 품종에 따라서 다르게 나타나서 당도 증가에 직접적인 영향을 끼치는 수용성 당은 품종의 차이를 보였다. The purpose of this research was to assess the sugar accumulation and related enzyme activities of peach fruit during fruit development. Fruit growth and development patterns of ‘Kanoiwa Hakuto’ (an early maturing cultivar), ‘Nagazawa Hakuho’ (a medium maturing cultivar), ‘Yumyeong’ (a late maturing cultivar) and ‘Changhowon Hwangdo’ (a very late maturing cultivar) were similar. In all cultivars, soluble solid content (SSC) increased rapidly as the fruit matured. The contrast, titratable acidity increased gradually until pit hardening stage, and then decreased as the fruit matured. Total soluble sugar content in fruit increased with fruit maturation. The change was almost sigmoid and mainly due to the change in sucrose which was the predominant soluble sugar in mature fruits, although initially glucose and fructose were the predominant soluble sugars in immature stage. Activity of sucrose synthase (SS) was high in young fruit and decreased as the fruit matured. That of SS increased again to high level with fruit maturation in all cultivars. On the other hand, sucrose-phosphate synthase activity was low throughout fruit maturation. Thus SS might account for the most portion of sucrose synthesis. Acid invertase (AI) activity was high at the initial fruit growth, and decreased to low level at ripening. Since AI activity was high at the early developmental stage, content of reducing sugars such as glucose and fructose were higher than sucrose content. There was the negative correlation between total starch and total soluble sugar. Sucrose was positively correlated with SSC in all the cultivars, while glucose, fructose and sorbitol showed negative correlations with SSC.

F10/F12 분기기에서의 가드레일 변화에 따른 주행안전성 해석

김성종(Kim, Sung Jong),엄범규(Eom, Beom Gyu) 한국도시철도학회 2013 한국도시철도학회논문집 Vol.1 No.1

기존선의 속도향상을 저해하는 요인은 매우 다양하지만 분기기 통과속도 제한규정은 그중 가장 대표적 사례로 손꼽히고 있다. 본 연구에서는 분기기에서의 속도향상을 목표로 대구 지하철공사 현장조사를 통한 분기기에서의 가드레일의 형상을 검토하였고, 개발한 분기기 해석기법을 통하여 F10/F12 분기에서의 가드레일 길이 변화에 따른 주행안전성 해석을 수행하였다. The speed-limit regulation on the turnout is the main cause which hinders the speed-up of conventional lines among many factors. The specification speed for the train which passes the turnout system is lower than that on the general track. In this paper, shape of guard rail of Daegu Metropolitan Transit Corporation was investigated, and the effect of the variation of guard rail length on the running safety of a vehicle was analyzed for the purpose of speed improvement on turnout using the developed analysis method.

북한 시장화와 사회적 자본

김성종(Kim, Sung-Jong) 충북대학교 국제개발연구소 2020 사회적경제와 정책연구 Vol.10 No.1

본 연구는 북한 시장화에 따른 사회구조 및 질서 변화를 사회적 자본의 관점에서 고찰하는 것을 목적으로 한다. 사회적 자본은 한 사회의 지배적 규범이나 가치체계의 특성을 거시적 관점에서 관찰할 때 발견할 수 있다. 사회적 자본의 핵심적 구성요소는 연결망, 규범, 신뢰이다. 시장화 이전 북한 사회의 대표적 연결망은 국가 또는 당 중심의 공식적 연결망이다. 공식적 연결망은 통제와 지시가 이루어지는 수직적이고 폐쇄적 연결망이었고 감시와 속박의 수단으로 기능했다. 연결망 구성원들은 상호 간 신뢰가 낮고 서로 무관심했다. 시장화 과정에서 거래와 교환을 목적으로 비공식적 연결망이 활성화되었다. 혈연적 연결망이 가장 기본이 되었고 다양한 연줄 관계가 형성되면서 자발성에 입각한 유기적 연대가 만들어지고 신뢰에 기반한 호혜성 규범이 생겨났다. 신뢰 대상에 대한 표준화가 이루어지고 신용거래가 등장하는 등 신뢰는 필수적 요소로 인식되었다. 북한 시장화 과정에서 등장한 연결망에 배태된 호혜성 규범이 사회 전반의 일반화된 호혜성으로 발전하지 못하고 있는 점이 현재 북한의 사회적 자본의 특성이라고 하겠다. The purpose of this study is to examine the changes in social structure and order due to the marketization of North Korea from the perspective of social capital. The key components of social capital are social networks, norms, and trust. The main social network of North Korean society before marketization was the official network of the one-party state. The formal network was a controlled, vertical-closed network that served as a means of monitoring and restraint. In the process of marketization, the kinetic network was the most basic, and various linkages were formed, resulting in spontaneous organic solidarity and trust-based reciprocity norms. Trust was recognized as an essential element with the standardization of trust targets and the emergence of credit transactions. It is North Korean social capital characteristics that have allowed the network that emerged from the process of marketization with embedded norms of reciprocity to develop without the development of generalized reciprocity in open society.

地方公共서비스 供給의 生產效率性 構造 分析

金聖鍾(Kim Sung-Jong) 한국지방자치학회 2000 韓國地方自治學會報 Vol.12 No.2

Various forms of Data Envelopment Analysis models were applied to investigate the productive efficiency in the provision of local public services in 70 Korean city governments. Technical efficiency scores and cost efficiency scores for each city governments were estimated. Major findings can be summarized as follows: (1) There are significant differences in technical efficiency between large city governments and small city governments, (2) Many city governments are operating in the increasing returns to scale technology, (3) In terms of inefficiency, technical inefficiency is more serious than cost efficiency. To reduce technical efficiency, government need to emphasize manpower training and organization restructuring.