• Journal of Advanced Marine Engineering and Technology
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• 제28권1호
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• pp.46-55
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• 2004

Thermal characteristics of the various cooling methods in electronic equipment are studied numerically. A common chip cooling system is modeled as a parallel channel with protruding heat sources. A two-dimensional model has been developed for the numerical analysis of compressible. viscous. laminar flow. and conjugate heat transfer between parallel plates with uniform block heat sources. The finite volume method is used to solve this problem. The assembly consists of two channels formed by two covers and one printed circuit board that is assumed to have three uniform heat source blocks. Various cooling methods are considered to find out the efficient cooling method in a given geometry and heat sources. The velocity and the temperature fields. the local temperature distribution along the surface of blocks. and the maximum temperature in each block are obtained. The results are compared to examine the thermal characteristics of the different cooling methods both quantitatively and qualitatively.

• 융합신호처리학회논문지
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• 제21권1호
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• pp.13-20
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• 2020

조선소에서는 선박 건조 시 설계 및 각 선체 블록의 제작 조립 후 선행의장이라는 것을 실시한다. 선행의장은 선체를 제외한 다른 부품, 장비들을 탑재하는 것을 의미하는데, 이 과정에서 블록 내 존재하는 파이프 및 다양한 장비들의 체결이 각 블록 간 조립 시 정확히 이루어지지 않는다면 오작업 및 그에 따른 생산품질 저하와 재작업 등에 따른 막대한 비용이 발생한다. 또한 이미 완료한 의장작업이라도 파이프 및 내부 자재 공간배치 등의 문제 발생 시 재작업에 따른 선박 생산효율이 나빠진다. 따라서 본 연구에서는 이러한 문제점 해결을 위해 3D 설계도면을 이용하여 공존현실 기술을 기반으로 한 선체의장 작업 전후 공간 배치 및 검사 시스템에 대해 소개하고자 한다. 본 연구에서 개발 및 소개한 다양한 공존현실 알고리즘 및 검사 시스템은 국내에는 도입이 전무한 AR 서비스를 기반으로 하고 있으므로 조선 선박제조 공정뿐 아니라 자동차, 건축 등 설계도면을 이용한 다양한 제조 산업 분야에 널리 적용 가능할 것으로 사료된다.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2002년도 봄 학술발표회 논문집
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• pp.351-351
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• 2002

새로운 LCST 형 블록 공중합체를 설계하기 위하여 LCST 블렌드 계를 선정하고, 이로부터 대응되는 블록 공중합체를 고안하였다 고안된 블록 공중합체의 분자 변수와 자기 집합에 의한 나노 미세 상 발현 거동과의 관계를 Cho의 압축성 random-phase approximation (RPA) 이론을 이용하여 구하였다. 본 연구의 대상 물질은 polystyrene (PS)과 poly(vinyl methyl ether) (PVME), PS 와 Poly(cyclo hexyl methacrylate) (PCHMA)의 블록 공중합체이다. (중략)

• 한국고분자학회지:고분자과학과기술
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• 제15권3호
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• pp.327-333
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• 2004

블록공중합체를 한 블록에 대해서만 선택적인 용매에 용해시키면 자발적인 상분리에 의하여 크기가 50 nm에서 200 nm 정도인 마이셀 구조로 자기 조립되며, 그 크기와 형태는 벌크상에서와 마찬가지로 블록공중합체의 분자량, 각 블록의 부피비, 각 블록간과 블록과 용매간의 Flory-Huggins 상호작용계수 ($\chi$)등에 의해서 결정된다. (중략)

• 접착 및 계면
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• 제6권2호
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• pp.21-28
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• 2005

• 산업기술연구
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• 제19권
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• pp.91-99
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• 1999

The dock is the most important resource in shipbuilding yard. Among the shipbuilding schedules, the ship erection schedule in a dock is preferentially built. As results of it, the other schedules(machining in plants, block assembly, pre-painting, pre-rigging, painting and etc) are made. In this study, ship erection scheduling is formulated using ILOG Scheduler. This study is to develop a new problem solving method for ship erection to make an effective schedule based on Constraint Satisfaction Technique(CST).

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.12-12
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• 2011

Interfacing functional materials with electrical or biological systems is of prime importance in terms of expanding applicative fields and obtaining high performances of devices. Herein, I report the functionalization of graphenes through supramolecular assembly and their electrochemical applications into fuel cells, supercapacitors, and biosensor devices. The solution processable nanohybridization of graphenes by functional materials such as ionic liquids, polyelectrolytes, block copolymers, and biomaterials, described herein would pave the way to obtain high performances of flexible energy and biosensor devices as well as to overcome the existing technology barriers.

• Carbon letters
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• 제15권4호
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• pp.295-298
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• 2014

In this work, nanoporous carbons (NPCs) were prepared by the self-assembly of polymeric carbon precursors and block copolymer template in the presence of tetraethyl orthosilicate and colloidal silica. The NPCs' pore structures and total pore volumes were analyzed by reference to $N_2$/77 K adsorption isotherms. The porosity and elemental mercury adsorption of NPCs were increased by activation with carbon dioxide. It could be resulted that elemental mercury adsorption ability of NPCs depended on their specific surface area and micropore fraction.

• Structural Engineering and Mechanics
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• 제16권6호
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• pp.713-730
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• 2003

This paper contains the results of the study on the development of fracture and crack propagation in quasi-brittle materials, such as concrete or rocks, using the Discrete Element Method (DEM). A new discrete element numerical model is proposed as the basis for analyzing the inelastic evolution and growth of cracks up to the point of gross material failure. The model is expected to predict the fracture behavior for the quasi-brittle material structure using the elementary aggregate level, the interaction between aggregate materials, and bond cementation. The algorithms generate normal and shear forces between two interfacing blocks and contains two kinds of contact logic, one for connected blocks and the other one for blocks that are not directly connected. The Mohr-Coulomb theory has been used for the fracture limit. In this algorithm the particles are moving based on the connected block logic until the forces increase up to the fracture limit. After passing the limit, the particles are governed by the discrete block logic. In setting up a discrete polygon element model, two dimensional polygons are used to investigate the response of an assembly of different shapes, sizes, and orientations with blocks subjected to simple applied loads. Several examples involving assemblies of particles are presented to show the behavior of the fracture and the failure process.

• Bulletin of the Korean Chemical Society
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• 제29권8호
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• pp.1539-1544
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• 2008

A polymeric micelle, based on the poly(benzyl-L-histidine)-b-poly(ethylene glycol) (polyBz-His-b-PEG) diblock copolymer, was designed as a tumor-specific targeting carrier. The micelles (particle size: 67-80 nm, critical micelle concentration (CMC); 2-3 $\mu$g/mL) were formed from the diafilteration method at pH 7.4, as a result of self-assembly of the polyBz-His block at the core and PEG block on the shell. Removing benzyl (Bz) group from polyBz-His block provided pH-sensitivity of the micellar core; the micelles were physically destabilized in the pH range of pH 7.4-5.5, depending on the content of the His group free from Bz group. The ionization of His group at a slightly acidic pH promoted the deformation of the interior core. These pHdependent physical changes of the micelles provide the mechanism for pH-triggering anticancer drug (e.g., doxorubicin: DOX) release from the micelle in response to the tumor’s extracellular pH range (pH 7.2-6.5).