열림 모드에 대한 형상 최적화

한석영,송시엽 한국공작기계학회 2001 한국공작기계학회 춘계학술대회논문집 Vol.2001 No.-

The relationship between structural geometry and number of life cycles to failure is investigated to improve the fatigue life of structural components. The linear elastic fracture mechanics(LEFM) approach is integrated with shape optimal design methodology. The primary objective of this study is to decide an optimal shape for enhancing the life of the structure. The results from LEFM analyses are used in the fatigue model to predict the life of the structure before failure is occurred. The shape of the structure is optimized by using the growth strain method. Relevant issues such as problem formulation, finite element modeling are explained. Three design examples are solved, and the results show that, with proper shape changes, the life of structural systems subjected to fatigue loads can be enhanced significantly.

지상파 TV 중간 광고의 상대적 가치 분석: 전/중/후CM의 성별, 연령, 시간대 등에 따른 차이 분석

한석영,박현수,권영빈 한국방송학회 2023 방송통신연구 Vol.- No.124

This study attempted to verify the exposure effects and cost efficiency of Mid-program advertising by using data for one year after the beginning of Network TV Mid-program advertising in Korea. In the absence of study about effects of Network TV Mid-program advertising, this study investigated the relative exposure effects and cost efficiency of Mid-program advertising, compared to Pre and Post program advertising. The strong exposure effects of Mid-program advertising was confirmed by analyzing the advertising ratings by gender, age, weekday/weekend, genre etc. In order to verify the difference in efficiency according to the advertising location, CPRP was converted to INDEX to check whether the difference gathered by gender, age, weekday/weekend, and time zone. As a result, advertising locations with excellent efficiency were different according to demographic variables. This study is the first to verify the exposure effects and value of Network TV Mid-program advertising in Korea. It has academic significance in that it quantitatively verified the exposure effects and cost efficiency using advertising ratings and CPRP as well. In addition, the results of this study can be used as basic data to calculate the appropriate value of Network TV Mid-program advertising. Aslo it has practical significance which contributes to mutual understanding between demand and supply of Mid-program advertising which can provide practical guidelines for efficient advertising in Korea.

위상 최적화 기법에 대하여

한석영 한국공작기계학회 2001 한국공작기계학회지 Vol.10 No.3

탠덤압연설비에서 테이퍼롤 채용에 의한 냉연강판 에지드롭 개선

한석영,이준정 대한기계학회 1994 대한기계학회논문집 Vol.18 No.1

In order to improve thickness profile of cold rolled steel strip, a computer simulation and actual cold rolling experiments on a 4-high tandem cold mill were carried out. In this study, tapered barrel end at top work roll and incurved barrel body at bottom work roll were examined for reducing edge drop and threading of stripe. Also, the most effective stand of tandem cold mill and magnitude of optimal taper crown at several stand were investigated under a typical rolling condition. From actual rolling experiments, it was verified that thickness deviation over strip width could be improved up to 1.06% by applying tapered and incurved work roll only at the second and up to 0.89% by applying them at both the second and the third stand.

디지털 레버리징: 기술을 인간의 삶에 적용하는 방법론

한석영,김희철,황원주 한국멀티미디어학회 2019 멀티미디어학회논문지 Vol.22 No.2

After the launch of smart phones, various miniaturized smart devices such as wearable and IOT devices have deeply embedded in human life, and have created a technology-oriented society. In this technologyoriented society, technology development itself is important, however it seems more important to utilize existing technology appropriately and deliver effectively to human life. As the computer became personalized after the appearance of PC, human-centered computing such as HCI and UCD had begun to appear. However, most of the researches focused on technology that made human being convenient to interact with computer such as computer systems design and UX development. In the technology-oriented society, it seems more urgent to apply existing technology to human life. In this paper, we propose a methodology, ‘Digital Leveraging’ which guides how to effectively apply technology to human life. Digital Leveraging is the way of convergence between technology and humanities.

체적제어에 의한 적층 복합재 구멍의 형상 최적화

한석영,마영준 대한기계학회 2004 大韓機械學會論文集A Vol.28 No.9

신경망 최적화 기법을 이용한 다익 홴/스크롤 시스템의 설부에 대한 형상 최적화

한석영,맹주성,유달현,진경욱,Han, Seog-Young,Maeng, Joo-Sung,Yoo, Dal-Hyun,Jin, Kyong-Uk 대한기계학회 2002 大韓機械學會論文集B Vol.26 No.10

In order to improve efficiency of a system with three-dimensional flow characteristics, this paper presents a new method that overcomes three-dimensional effects by using two-dimensional CFD and neural network. The method was applied to shape optimization of cut-off in a multi-blade fan/scroll system. As the entrance conditions of two-dimensional CFD, the experimental values at the positions out of the inactive zone were used. The distributions of velocity and pressure obtained by two-dimensional CFD were compared with those of three-dimensional CFD and experimental results. It was found that the distributions of velocity and pressure have qualitative similarity. The results of two-dimensional CFD were used for teaming as target values of neural network. The optimal angle and radius of cut-off were determined as 71$^{\circ}$and 0.092 times the outer diameter of impeller, respectively. It is quantified in the previous report that the optimal angle and radius of cut-off are approximately 72$^{\circ}$and 0.08 times the outer diameter of impeller, respectively.

마이크로폴라 탄성이론

한석영 대한기계학회 1990 大韓機械學會誌 Vol.30 No.3

마이크로폴라 탄성이론은 다른 마이크로연속체(microcontinuum) 이론에 비해 적용이 간단하며, 실제 많은 물리적인 현상을 규명하는 데 다양하게 이용할 수 있다. 특히 고전 탄성이론에 의해 적절하게 해결될 수 없는 덤벨(dumbell) 분자로 이루어진 물체, 액체 결정체(liquid crystals), 과립상(granular)의 분자로 구성된 물체와 복합 섬유재료(composite fibrous materials) 등은 마 이크로폴라 탄성이론에 의해 잘 해결될 수 있다. 또한 마이크로폴라 탄성이론은 고체 내에서의 파의 전파(propagation)와 분산(dispersion), 구멍 주위의 응력집중과 외부 하중을 받는 물체에 있어 균열끝에서의 응력 분포 등의 고체역학 문제들은 물론이고, 경계층(boundary layer), 난 류(turbulence), 유체 유동의 불안정(instability)과 표면장력 현상 등의 유체역학에서의 복잡한 문제들을 해결하는 데에도 이용할 수 있다. 마이크로폴라 탄성이론은 고전 탄성이론에 비해 상 대적으로 새롭고 미개척 분야이긴 하지만 이론의 기반이 확고하기 때문에 앞으로의 회전응력 측정장치의 개발을 통해 미소구조의 영향을 고려해야 하는 많은 문제들을 해결하는데 큰 기여를 할 것으로 전망된다.

밀도분포법을 이용한 부재의 연결구조 최적화

한석영,유재원 한국공작기계학회 2003 한국생산제조학회지 Vol.12 No.4

Most engineering products contain more than one component. Failure occurs either at the connection itself or in the component at the point of attachment of the connection in many engineering structures. The allocation and design of connections such as bolts, spot-welds, adhesive etc. usually play an important role in the structure of multi-components. Topology optimization of connection component provides more practical solutions in design of multi-component connection system. In this study, a topology optimization based on density distribution approach has been applied to optimal location of fasteners such as T-shape, L-shape and multi-component system. From the results, it was verified that the number of iteration was reduced, and the optimal topology was obtained very similarly comparing with ESO method. Therefore, it can be concluded that the density distribution method is very suitable for topology optimization of multi-component structures.

워크 롤 타입 변화에 의한 규소강판 에지 드롭 개선

한석영,김종택,이영호,이준정,김종근 대한기계학회 1990 대한기계학회논문집 Vol.14 No.4

본 연구에서는 에지 드롭 현상이 가장 심하게 나타나고 있는 M-class 저급 무 방향성 규소 강판을 대상으로 MKW압연기의 롤 탄성변형 해석을 컴퓨터 시뮬레이션을 통하여 수행함으로써 에지 드롭을 최소화할 수 있는 개선책을 마련하였고 실제 현장 압연실험을 통하여 그 결과를 확인하였다.