흥분제(Psychostimulants)에 대한 신경생물학 측면의 고찰 -Methamphetamine 남용을 중심으로

이태경,존 E 그랜트,김석원,오동열,Lee Tae Kyung,Jon E. Grant,Kim, Suck Won,Oh Dong Yul 대한임상독성학회 2003 대한임상독성학회지 Vol.1 No.1

Methamphetamine (MA) is a major drug of abuse in Korea. Currently preliminary evidence suggests that MA dependence may cause long-term neural damage in human. Repeated exposure to psychostimulants such as methamphetamine results in behavioral sensitization, a paradigm thought to be relevant to drug craving and addiction in human. Sensitization alters neural circuitry involved in normal processes of incentrive, motivation, and reward. However the precise mechanism of this behavioral sensitization has not yet been fully elucidated. Repeated use of high dose MA causes neurotoxicity which is characterized by a long-lasting depletion of striatal dopamine (DA) and tyrosin hydroxylase activity of DA, DA-transporter binding sites in the striatum. The loss of DA transporters correlates with memory problems and lack of motor coordination. DA fuels motivation and pleasure, but it' s also crucial for learning and movement. This selective review provides a summary of studies that assess the neurobiological mechanisms of MA.

Mechanisms of Tensile Improvement in Caliber-Rolled High-Carbon Steel

이태경,Chan Hee Park,Sang-Yoon Lee,Il-Heon Son,Duk-Lak Lee,이종수 대한금속·재료학회 2012 METALS AND MATERIALS International Vol.18 No.3

The microstructural evolution and tensile characteristics of caliber-rolled plain carbon steels were quantita-tively investigated and compared with those of the as-received plain carbon steels. The caliber-rolled steels exhibited a similar microstructure consisting of an ultrafine-grained ferritic matrix and dispersed fine cementite particles. In contrast to the general trend of caliber-rolling processes showing significant reduc-tions in elongation while retaining a high strength, the present caliber-rolled high-carbon steel exhibited simultaneously improved strength and elongation. This distinctive tensile enhancement of the caliber-rolled high-carbon steel was attributed to the increased strain hardening rate caused by the high fraction of sub-micron cementite particles and to the transition of the fracture mode from a brittle state to a ductile state.

IMC의 영향에 따른 Flip-Chip Bump Layer의 열변형 해석

이태경,김동민,전호인,허석환,정명영,Lee, Tae Kyoung,Kim, Dong Min,Jun, Ho In,Huh, Seok-Hwan,Jeong, Myung Young 한국마이크로전자및패키징학회 2012 마이크로전자 및 패키징학회지 Vol.19 No.3

최근 전자 제품의 소형화, 박형화 및 집적화에 따라 칩과 기판을 연결하는 범프의 미세화가 요구되고 있다. 그러나 범프의 미세화는 직경 감소와 UBM의 단면적 감소로 인하여 전류 밀도를 증가시켜 전기적 단락을 야기할 수 있다. 특히 범프에서 형성되는 금속간화합물과 KV의 형성은 전기적 및 기계적 특성에 큰 영향을 줄 수 있다. 따라서 본 논문에서는 유한요소해석을 이용하여 플립칩 범프의 열변형을 분석하였다. 우선 TCT의 온도조건을 통하여 플립칩 패키지의 열변형 특성을 분석한 결과, 범프의 열 변형이 시스템의 구동에 큰 영향을 미칠 수 있음을 확인하였다. 그리고 범프의 열변형 특성에 큰 영향을 미칠 것을 생각되는 IMC층의 두께와 범프의 직경을 변수로 선정하여 온도변화, 열응력 및 열변형에 대한 해석을 수행하였으며, 이를 통하여 IMC층이 범프에 영향을 미치는 원인에 대한 분석을 수행하였다. Recently, by the trends of electronic package to be smaller, thinner and more integrative, fine bump is required. but It can result in the electrical short by reduced cross-section of UBM and diameter of bump. Especially, the formation of IMCs and KV can have a significant affects about electrical and mechanical properties. In this paper, we analyzed the thermal deformation of flip-chip bump by using FEM. Through Thermal Cycling Test (TCT) of flip-chip package, We analyzed the properties of the thermal deformation. and We confirmed that the thermal deformation of the bump can have a significant impact on the driving system. So we selected IMCs thickness and bump diameter as variable which is expected to have implications for characteristics of thermal deformation. and we performed analysis of temperature, thermal stress and thermal deformation. Then we investigated the cause of the IMC's effects.

SysML 기반 문서 모델링 사례

이태경,차재민,김준영,Lee, Taekyong,Cha, Jae-Min,Kim, Joon-Young,Salim, Shelly 한국시스템엔지니어링학회 2018 시스템엔지니어링학술지 Vol.14 No.2

In traditional Document Based Configuration Management(DBCM) environment, changes in a system's configurations are hard to be reflected to existing engineering documents. This nature of DBCM triggers unconformities of system configurations which could become great risks. Model-based Configuration Management(MBCM) has been introduced to solve the problem of DBCM by managing system's configurations through an unified model. Therefore, it is important to model engineering documents in a general modeling language, down to low-level information items to develop traceability and flexibility of a system's engineering information. So, in the research, to explore the possibility of Model-based Approach(MBA) in the field of configuration management, a development of a systems requirement document model using SysML based Views & Viewpoints concept has been studied.

시스템 엔지니어링 공통 프로세스 개선 연구 : 기술 프로세스를 중심으로

이태경,이중윤,Lee, Taekyong,Lee, Joong-Yoon 한국시스템엔지니어링학회 2017 시스템엔지니어링학술지 Vol.13 No.1

Systems engineering is being applied to various fields of industry such as national defense, aerospace, transportation, railway, and information technology industries. But in Korea, systems engineering has been selectively applied to government-driven projects such as space rocket development projects and unmanned flight development projects. And systems engineering processes introduced from international systems engineering standards has been directly applied to those projects. Unfortunately, this application method is not recommended as it requires highly experienced systems engineers. From our previous paper, we have proposed that domain specific engineering standards should be developed to be used as references for development of organizational engineering guide, so that more successful engineering performances can be achieved. And in this paper we have proposed a refinement of systems engineering processes from international systems engineering standards as they are bases of domain specific engineering standards.

SysML DSL 기반 플랜트 모델링 케이스

이태경,차재민,김준영,신중욱,김진일,염충섭,Lee, Taekyong,Cha, Jae-Min,Kim, Jun-Young,Shin, Junguk,Kim, Jinil,Yeom, Choongsub 한국시스템엔지니어링학회 2017 시스템엔지니어링학술지 Vol.13 No.2

Implementation of Model-based Systems Engineering(MBSE) depends on a model supporting efficient communication among engineers from various domains. And SysML is designed to create models supporting MBSE but unfortunately, SysML itself is not practical enough to be used in real-world engineering projects. SysML is designed to express generic systems and requires specialized knowledge, so a model written in SysML is less capable of supporting communication between a systems engineer and a sub-system engineer. Domain Specific Languages(DSL) can be a great solution to overcome the weakness of the standard SysML. A SysML based DSL means a customized SysML for a specific engineering domain. Unfortunately, current researches on SysML Domain Specific Language(DSL) for the plant engineering industry are still on the early stage. So as the first step, we have developed our own SysML based Piping & Instrumentation Diagram (P&ID) creation environment and P&ID itself of a specific plant system, using a widely used SysML authoring tool called MagicDraw. P&ID is one of the most critical output during the plant design phase, which contains all information required for the plant construction phase. So a SysML based P&ID has a great potential to enhance the communication among plant engineers of various disciplines.

노드의 연결성을 이용한 패스 표현의 효과적인 처리

이태경,Lee, Tae-Gyeong 한국정보처리학회 2002 정보처리학회논문지D Vol.9 No.3

Recently, there has been a lot of research on graph-type data because it can model seamless the application domains such as GIS, network, WWW, multimedia presentations etc., and domain in which the data sequence is important. In this paper, an efficient code system, called node code system, is proposed to evaluate paths of DAG in a multimedia presentation graph. The node code system assigns a unique binary string to each node of a graph. The comparison of node codes of two nodes tells the connectivity between the nodes without actual traversal of a graph. The method using the property of the node code system allows us to construct the paths between two nodes more efficiently than the method using conventional graph traversals. The algorithms to construct paths using the node code system are provided. 최근에 그래프 타입의 자료에 대한 연구가 이루어지고 있다. 그 이유는 그래프가 지리정보시스템, 네트워크, WWW, 멀티미디어 프리젠테이션 등과 같은 영역의 문제들을 자연스럽게 표현할 수 있으며 자료 변화의 순서가 중요한 영역의 문제들도 자연스럽게 표현할 수 있기 때문이다. 이 논문에서는 방향 비순환 그래프로 표현되는 멀티미디어 프리젠테이션 그래프의 경로를 효과적으로 검색 처리하는 코드 시스템인 노드 코드 시스템을 제안한다. 노드 코스 시스템은 그래프의 각 노드마다 유일한 2진 문자열을 부여한다. 두 노드의 노드 코드를 비교하여 그래프 운행 없이 두 노드가 연결되어 있는지를 확인할 수 있다. 전통적인 그래프 운행을 이용한 방법보다 노드 코드 시스템의 이 특성을 이용하면 두 노드 사이의 경로의 건설을 효과적으로 할 수 있다. 노드 코드 시스템을 이용하여 경로를 건설할 수 있는 알고리즘을 제시한다.

CMP 패드 두께 프로파일 측정 장치 및 방법에 관한 연구

이태경,김도연,강필식,Lee, Tae-kyung,Kim, Do-Yeon,Kang, Pil-sik 한국산업융합학회 2020 한국산업융합학회 논문집 Vol.23 No.6

The chemical mechanical planarization (CMP) is a process of physically and chemically polishing the semiconductor substrate. The planarization quality of a substrate can be evaluated by the within wafer non-uniformity (WIWNU). In order to improve WIWNU, it is important to manage the pad profile. In this study, a device capable of non-contact measurement of the pad thickness profile was developed. From the measured pad profile, the profile of the pad surface and the groove was extracted using the envelope function, and the pad thickness profile was derived using the difference between each profile. Thickness profiles of various CMP pads were measured using the developed PMS and envelope function. In the case of IC series pads, regardless of the pad wear amount, the envelopes closely follow the pad surface and grooves, making it easy to calculate the pad thickness profile. In the case of the H80 series pad, the pad thickness profile was easy to derive because the pad with a small wear amount did not reveal deep pores on the pad surface. However, the pad with a large wear amount make errors in the lower envelope profile, because there are pores deeper than the grooves. By removing these deep pores through filtering, the pad flatness could be clearly confirmed. Through the developed PMS and the pad thickness profile calculation method using the envelope function, the pad life, the amount of wear and the pad flatness can be easily derived and used for various pad analysis.

시스템 엔지니어링 표준 기반 제철 플랜트 엔지니어링 업무표준 개발 사례

이태경,조래혁,이중윤,Lee, TaeKyong,Cho, RaeHyuk,Salim, Shelly,Lee, JoongYoon 한국시스템엔지니어링학회 2016 시스템엔지니어링학술지 Vol.12 No.1

Plant engineering industry is considered as a key industry which will drive the future of Korea. However, Korean plant engineering companies have recently made huge losses in overseas businesses and the lack of engineering capability is pointed out as a main cause of this situation. Unlike Korean plant engineering companies, world leading engineering companies such as Flour and Bechtel have their own systems Engineering Standards/Guides ensuring successful fulfillments of the concept and basic design processes. An engineering standard for an organization is an essential means to shorten the time for engineering design, to maintain the engineering quality and to secure the engineering efficiency in the development of the complex system. Korean plant engineering companies'lack of engineering capability comes from the absence of the engineering standard. In the paper, we have developed a steel-making plant engineering standard based on a systems engineering standard. We chose both ISO/IEC/IEEE 15288 and NASA SE Handbook as main reference standards. First, we have introduced a life-cycle definition and a physical hierarchy of a general steel-making plant. Then we have introduced detailed engineering processes of each life-cycle stage. The full scope of the study was from the feasibility study to the basic design but in the paper, we have only introduced detailed engineering processes and exit criteria for the feasibility study and the concept design.

마이크로 패턴 구조를 이용한 플립칩 패키지 BGA의 최적 열설계

이태경,김동민,전호인,하상원,정명영,Lee, Tae-Kyoung,Kim, Dong-Min,Jun, Ho-In,Ha, Sang-Won,Jeong, Myung-Yung 한국마이크로전자및패키징학회 2011 마이크로전자 및 패키징학회지 Vol.18 No.3

소형화, 박형화 및 집적화의 경향에 따라 FCBGA가 휴대폰과 같은 전자제품에 활발히 사용되고 있다. 그러나, 플립칩은 전기적 저항에 의한 열이 필연적으로 발생하며, 발생된 열은 패키지의 소형화에 따라 열의 분산 면적 감소로 인하여 발열의 증가가 나타나게 된다. 발열은 온도와 응력에 민감하게 반응하는 소자의 수명을 저해하고, 시스템에 있어 고장의 발생을 가져올 수 있다. 따라서 본 논문에서는 플립칩의 발열문제를 해결하기 위하여 Comsol 3.5a의 heat transfer module을 이용하여 FCBGA의 발열 특성을 정량적으로 분석하였다. 그리고 열 문제를 해결하기 위하여 시뮬레이션을 통한 새로운 마이크로 구조가 부착된 플립칩을 제안하였다. 또한 마이크로 패턴 구조의 형상, 높이, 간격에 대한 열 소산을 분석함으로써, 기존 플립칩에 비하여 열소산 특성이 18% 향상됨을 확인하였다. According to the trends of electronic package to be smaller, thinner and more integrative, Flip Chip Ball Grid Array (FCBGA) become more used for mobile phone. However, the flip chip necessarily generate the heat by the electrical resistance and generated heat is increased due to reduced distribution area of the heat in accordance with the miniaturization trend of the package. Thermal issues can result in problems of devices that are sensitive to temperature and stress. Then the heat can generate problems to the system. In this paper, in order to improve the thermal issues of FCBGA, thermal characteristics of FCBGA was analyzed qualitatively by using the general heat transfer module of Comsol 3.5a and In order to solve thermal issues, flip chip with new micro structure is proposed by the simulation. and also by comparing existing model and analyzing variables such as pitch, height of the pattern and shape of the heat spreader, the improvement of heat dissipation characteristics about 18% was confirmed.