• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.80-80
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• 2006

As the size scale of features continue to shrink in devices, the use of self-assembly, i.e. a "bottom up" approach, for device fabrication becomes increasingly important. Yet, simple self-assembly alone will not be sufficient to meet the increasing demands place on the registry of structures, particularly nanostructured materials. Several criteria are key in the rapid advancement and technology transfer for self-assembling systems. Specifically, the assembly processes must be compatible with current $^{\circ}{\infty}top\;down^{\circ}{\pm}$ approaches, where standard photolithographic processes are used for device fabrication. Secondly, simple routes must be available to induce long-range order, in either two or three dimensions, in a rapid, robust and reliable manner. Thirdly, the in-plane orientation and, therefore, ordering of the structures, must be susceptible to a biasing by an external, macroscopic means in at least one, if not two directions, so that individual elements can be accessed in a reliable manner. Block copolymers, specifically block copolymers having a cylindrical microdomain morphology, are one such material that satisfy many, if not all, of the criteria that will be necessary for device fabrication. Here, we discuss several routes by which these versatile materials can be used to produce arrays of nanoscopic elements that have high aspect ratios (ideal for templating and scaffolding), that exhibit long-range order, that give access to multiple length scale structuring, and that are amenable to being biased by macroscopic features placed on a surface.

• 대한기계학회논문집A
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• 제24권4호
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• pp.811-823
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• 2000

In design and manufacturing airframe structures which are composed of a lot of sub-assemblies and large complex profile shapes it is difficult to reduce so called hardware variations. Accordingly cost increasing factors for manufacturing airframe parts are much more than other machine parts because of the variability of fabricated details and assemlies. To improve cost and quality, accurate assembly methods and DPD techniques are proposed in this paper which are based upon using CAD/CAM techniques, the concept of KC's and the coordinated datum and index throughout the design, tooling, manufacturing and inspection. The proposed methods are applied to produce fuselage frame assemblies and related engineering aspects are described regarding the design of parts and tools in the context of concurrent digital definition. First articles and consequent mass production of frame assemblies shows a great improvement of the process capability ratio from 0.7 by the past processes to 1.0 by the proposed methods in addition to the cost reduction due to the less number of tools, reduced total assembly times and the space compaction needed by massive inventory. The need to achieve better Cpk, however, and future studies to be investigated will be addressed briefly.

• 생명과학회지
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• 제8권2호
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• pp.223-233
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• 1998

Molecular chaperone의 발견은 생명과학자들에게 살아있는 세포 내에서 어떻게 생체활성단백질이 만들어지고 유지되는지에 대한 자극과 함께 그것을 증명하기 위한 실험동기를 부여하였다. 초기에는 Molecular chaperone이 nucleosomes의 assembly에 관여하는 단백질을 설명하기 위하여 사용되었으나, 지금은 기본적인 세포생리기능의 하나인 단백질의 folding과 assembly를 돕는 assistant protein으로 주로 사용된다. 단백질합성 뿐만 아니라 단백질수송, oligomeric structure의 assembly와 disassembly, heat shock을 포함한 각종 내, 외부스트래스에 의해서 변성된 단백질의 세로내분화와 회복에도 Molecular chaperone이 관여하고 있다. 그러나 아직까지는 Molecular chaperone들의 3차구조와 그들간의 상호작용에 관한 정보가 부족하여 크게 진전되지 못하고 있지만, 많은 연구자에 의한 정보축적으로 인하여 빠른 시일 내에 Molecular chaperone에 세포내역할이 분명하게밝혀질 것이다.

• Bulletin of the Korean Chemical Society
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• 제26권4호
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• pp.553-557
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• 2005

The formation of striped phases of unsymmetric hexyl octadecyl disulfide ($CH_3(CH_2)_5SS(CH_2)_{17}CH_3$, HOD) and 1-hydroxyundecyl octadecyl disulfide ($CH_3(CH_2)_{17}SS(CH_2)_{11}$OH, HUOD) on Au(111) and graphite has been investigated by scanning tunneling microscopy (STM) to understand the self-assembly processes of dialkyl disulfides. STM imaging clearly shows the formation of striped phases having corrugation periodicities that are nearly consistent with the molecular length of alkanethiolate moieties formed after the S-S bond cleavage of dialkyl disulfide on a gold surface. On the other hand, self-assembled monolayers (SAMs) of dialkyl disulfides on a graphite surface displayed long-range, well-ordered monolayers with one striped pattern that shows periodicity as a function of molecular length via nondissociative adsorption. From a nonoscopic viewpoint, we have clearly demonstrated that dialkyl disulfide SAMs on gold form via S-S bond cleavage of disulfide.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.185-189
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• 2002

Flexible displays such as plastic based LCDs and organic light-emitting diodes for mobile communication devices have been researched and developed at KETI in KOREA since 1997. The Plastic film substrate has so poor thermal tolerance and non-rigidness that the fabrication of active devices and panel assembly have to perform at low temperature and pressure. In addition, high thermal expansion of the substrate is also a serious problem for reliable metallic film deposition. In this paper, we investigated particularly on the fundamental characteristics of various plastic substrates and then, suggested novel methods that improve the fabrication processes of plastic LCD panel. In order to maintain stable substrate surface and uniform cell gap during panel assembly, we utilized newly-invented iii and vacuum chuck. Electro-optical characteristics of fabricated plastic LCD are better than or equivalent to those of typical glass based LCDs though it is thinner, lighter-weight and more robust.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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• pp.439-443
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• 1987

This paper presents a method for constructing model of manufacturing processes for simulation and design of the discrete control logic. The models represent the discrete vent evolution of the system as well as features of the underlying continues processes, for applications such as discrete parts manufacture and assembly, the process is decomposed into operations and for each operation the required resources and associated discrete resource slates are Identified. The structure of the discrete-level control is modeled by modified Perti nets which are synthesized from single resource activity cycles. Construction of nets provides discrete control logic with guaranteed properties based on extended Petri nets theory, for illustration, the proposed method is applied to the high-level discrete control of a two-robotic assembly cell.

• 산업공학
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• 제14권2호
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• pp.120-126
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• 2001

Virtual manufacturing is a technology facilitating effective development and agile manufacturing of products via sophisticated computer models representing physical and logical schema and behavior of real manufacturing systems including manufacturing resources, environments, and products. Based on these models, virtual manufacturing supports decision making and error checking in the entire manufacturing processes from design to mass production. At first, we analyzed manufacturing preparation activities of the four major production shops such as press, body assembly, painting and final assembly, of a Korean automotive company. We then developed the workflow models out of the analysis by the IDEF methodology, and generated a strategic plan for the systematic application of the virtual manufacturing technologies. We identified many manufacturing preparation activities that can be improved by the application of virtual manufacturing technologies. Finally, we estimated the effect of improvement including time savings in car development processes and corresponding cost savings.

• Industrial Engineering and Management Systems
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• 제8권2호
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• pp.109-120
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• 2009

As the use of 3DCAD data became widespread in designing products in manufacturing, attempts have been made to shorten lead time and reduce cost of production preparation utilizing 3DCAD data for launching assembly lines. In order to create assembly plans not only efficient but easy for operators to operate ('easy-to-operate'), this study presents approaches, methods, and systems for creating 3DCGAs (3 Dimensional Computer Graphic Animations) which automatically utilize a prototype-free production preparation methodology. Characteristics of this study include that it proposes the methodology for creating assembly operation 3DCGAs automatically, for all the possible assembly operations corresponding each of the possible assembly sequences first. Using the created 3DCGAs, the study next considers assembly methods by evaluating how easy or 'operator friendly' they are in implementing, and devises tools or jigs to be used, and plans efficient assembly line organization. The concept of the methodology was formed by focusing on the value-adding assembly steps at which parts turn into products directly. The study also validates the effectiveness of the presented methodology by employing the methods used in actual production preparation process in businesses, and proves that an efficient assembly line can be organized in a shorter period of time utilizing the developed system and by preparing easy-to-operate and efficient plans in 3DCGAs at the design stage.

• 정보처리학회논문지B
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• 제13B권2호
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• pp.139-148
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• 2006

협업적 제품 설계 환경에서는 여러 설계자가 작업에 참여하기 때문에 설계자간의 원활한 의사 소통이 필수적인 요소이다. 즉, 제품 설계에 내재되어 있는 다른 설계자의 설계의도를 파악할 수 있어야 하고, 각 설계자마다 사용하고 있는 상이한 모델링 용어에 대한 의미적 처리가 필요하다. 시맨틱 웹에서 온톨로지는 의미 정보를 명시적으로 표현할 수 있기 때문에 데이터와 서비스에 대한 통합되고 일관된 접근을 가능하게 한다. 따라서 제품을 여러 설계자가 설계하는 협업적 환경에서 온톨로지를 사용한다면 조립체내의 내포된 공학적 관계들, 공간적 관계들, 그리고 접합 관계들이 명확하게 표현되고, 추론을 통해 설계자의 의도가 파악되어 설계자간의 의사소통이 원활하게 이루어질 수 있다. 본 논문에서 는 조립체를 온톨로지를 이용하여 표현함으로써 협업적 환경에서 조립체 설계정보를 공유할 수 있는 시맨틱 조립체 모델링 프레임워크를 제안한다. 시맨틱 조립체 모델링 프레임워크에서는 조립체 관계 모델(Assembly Relationship Model, ARM)을 OWL(Web Ontology Language)와 SWRL(Semantic Web Rule Language)로 표현한다. 이를 통해 조립체 내에 내포된 공학적 관계들, 공간적 관계들, 그리고 접합 관계들이 명확하게 표현되고, 추론되어 설계 의도가 파악된다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 춘계학술발표대회 논문집
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• pp.163-166
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• 2002

For the development of an all composite unmanned aerial vehicle (UAV), manufacturing consideration in design phase, works for composite parts fabrication, subassembly and final assembly are summarized. In design phase, to maximize the advantage of composite material, manufacturing processes such as cocuring, cobonding and secondary bonding are introduced. For the curing of designed parts, composite tools are designed and manufactured. Assembly jigs are designed to satisfy dimensional tolerance of the structure. Inspection criteria are established and applied to the manufacturing. Technical data about inspection items and methods are summarized as manufacturing specifications for the mass production of the UAV structure.