• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 지반공학 공동 학술발표회
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• pp.639-648
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• 2005

Up to now, practical engineers applying simplicity value of rockfall block weight suggested in design manual without considering in-situ rockfall block weight which reflect joint characteristics. However, the size of rockfall block varies with joint spacing of discontinuities and influences over rockfall analysis results. In this paper, we estimate realistic rockfall block weight distribution using statistical invariances of joint spacing derived from scan-line survey result. And, we study whether this distribution is applicable in practical rockfall analysis directly. As the results of this study, rockfall analysis results that using rockfall block weight distribution estimated from scan-line survey show resonable and realistic outcomes.

• Korean Chemical Engineering Research
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• 제46권1호
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• pp.1-6
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• 2008

블록공중합체(block copolymer)는 각 고분자 블록의 상대적인 조성비와 분자량에 따라 구, 실린더, 라멜라 등의 다양한 자기조립 나노구조를 형성하는 것으로 알려져 있다. 최근에는 블록공중합체의 자기조립 나노구조를 이용하여 나노복합재료, 포토닉 크리스탈, 나노선, 자기저장매체, 플래시 메모리 소자 등에 적용하려는 연구들이 활발히 진행되고 있다. 그러나 자연적으로 형성되는 블록공중합체 나노구조는 수많은 결함구조들을 포함하고 있어 실제 소자 적용에 큰 걸림돌이 되고 있다. 블록공중합체 나노구조의 실제적인 응용을 위해서는 박막상태의 시료 내에서 나노구조의 배향과 배열을 원하는 형태로 조절할 수 있는 공정의 확립이 선행되어야 한다. 즉, 블록공중합체의 자기조립을 나노기술분야에 적용하기 위해서는 대면적으로 완벽히 제어된 블록공중합체 나노구조를 구현하는 것이 필요하다.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.293-293
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• 2006

Self-assembled nanostructures of block copolymer thin films have gathered significant attention due to their potential applications as templates for nanofabrication. However the lack of a robust strategy to control the structure formation in thin film geometries has been considered a major obstacle for the practical application. In this presentation 'epitaxial self-assembly' will be introduced as a successful strategy to control the self-assembled nanostructure of block copolymer. Chemically patterned surfaces prepared by advanced lithographic techniques successfully registered nanodomains in block copolymer thin film without any single defect over an arbitrarily large area.

• Asian-Australasian Journal of Animal Sciences
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• 제1권4호
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• pp.233-239
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• 1988

The base of Indian milk production is the millions of nondescript cows and buffaloes in rural areas, fed mainly on crop residues and agro-industrial wastes. The mainstay of the feeding system is straws and stovers. Therefore the approach to increase the fibrous residues utilisation for animal production was ideal and useful. The methods available for the above purpose were not found acceptable in rural areas owing to certain practical problems. The development of urea molasses block was, therefore aimed at solving the practical field problems. Urea Molasses Block has been developed as a feed supplement that can bring forth an effect of rumen manipulation thereby increase the conversion rate of feeds. The formula and process technology were thus developed. Before starting the mass production and popularisation the product was tested in controlled condition in farms and also in villages. Encouraged with the results the feed is now commercially manufactured under Indian Patent No. 156047.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2006년도 춘계 학술대회 개요집
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• pp.77-79
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• 2006

To achieve high productivity of assembly hull blocks, it is important to predict welding deformations accurately and to apply these data to the production planning. In the deformation analysis of hull block, simplified methods (elastic analysis) such as inherent method, equivalent loading method and local & global approach are usually used instead of thermal-elastic-plastic analysis because of calculating time and cost. To be much more practical, these simplified methods should consider gravity effect of plate and contact condition between the plate and the positioning jig. In this research, using finite element method, practical predicting method for the welding deformation of the curved hull blocks with considering welding sequence, gravity effect and contact condition is proposed.

• 한국정보전자통신기술학회논문지
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• 제10권6호
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• pp.587-593
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• 2017

본 논문에서는 로봇제어분야의 이론적인 내용에 대해서 실제 실습교육이 가능한 환경을 구축하는데 따른 애로를 해결하기 위한 하나의 방안을 제시하기 위해서 세그웨이 구조의 양바퀴 이동로봇을 레고(LEGO) 블록을 사용하여 제작하고, 제작된 로봇이 로봇공학 교육의 동적시스템이나 비선형 시스템과 같은 고급제어 이론기술을 적용하는 실습용으로 활용하는 것에 대한 타당성을 제시하기 위하여 로봇이 주행 중에 중력의 변화에 대해서도 균형을 유지하면서 안정된 자세를 취하도록 하는 자세제어에 대한 실험을 수행하고 그 결과를 제시하였다. 로봇의 자세제어 주행 실험은 평면과 경사로에서 각각 수행하였으며, 평면 주행실험에서는 장애물을 인식하고 회피하는 실험을 병행하여 그 결과도 함께 제시함으로써 로봇공학의 고급제어 이론의 실습교육용으로 레고(LEGO) 블록을 이용해서 제작한 로봇이 효과적인 실습도구로 활용될 수 있음을 확인하였다.

• International Journal of Internet, Broadcasting and Communication
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• 제12권1호
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• pp.67-72
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• 2020

The fifth generation (5G) mobile communication has an impact on the human life over the whole world, nowadays, through the artificial intelligence (AI) and the internet of things (IoT). The low latency of the 5G new radio (NR) access is implemented by the state-of-the art technologies, such as non-orthogonal multiple access (NOMA). This paper investigates a practical issue that in NOMA, for the practical channel models, such as fading channel environments, the successive interference cancellation (SIC) should be performed on the stronger channel users with low power allocation. Only if the SIC is performed on the user with the stronger channel gain, NOMA performs better than orthogonal multiple access (OMA). Otherwise, NOMA performs worse than OMA. Such the superiority requirement can be easily implemented for the channel being static or slow varying, compared to the block interval time. However, most mobile channels experience fading. And symbol by symbol channel estimations and in turn each symbol time, selections of the SIC-performing user look infeasible in the practical environments. Then practically the block of symbols uses the single channel estimation, which is obtained by the training sequence at the head of the block. In this case, not all the symbol times the SIC is performed on the stronger channel user. Sometimes, we do perform the SIC on the weaker channel user; such cases, NOMA performs worse than OMA. Thus, we can say that by what percent NOMA is better than OMA. This paper calculates analytically the percentage by which NOMA performs better than OMA in the practical mobile communication systems. We show analytically that the percentage for NOMA being better than OMA is only the function of the ratio of the stronger channel gain variance to weaker. In result, not always, but almost time, NOMA could perform better than OMA.

• 한국정보처리학회논문지
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• 제3권5호
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• pp.1329-1336
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• 1996

많은 영상 데이타 압축 응용분야에서 DCT는 높은 압축 성능으로 인하여 널리 잘 알려져 있다. 그러나 낮은 비트율에서는 인간의 시각에 거슬리는 블록 효과(block artifacls)가 생기는 문제점을 가지고 있다. 또한 실제적인 응용에 있어서, DCT계수의 빠른 계산과 간단한 VLSI 구현도 중요한 과제이다. 따라서 블록 효과의 제거와 빠른 CT 계산은 실제적인 연구의 대상이 된다. 본 논문에서는 수정된 DCT 계산 방법을 연구 하였고, 이것은 빠른 계산과 함께 블록 효과를 효과적으로 제거할 수 있었다. 이러한 새로운 접근 방법을 낮은 비트 율에서 영상의 부호화 및 복호화에 적용하였다. 실제 영상을 대상으로 실험한 결과, 제안된 방법을 통해 표준적인 방법에 비하여 성능을 개선할 수 있었다.

• 대한기계학회논문집B
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• 제22권12호
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• pp.1746-1754
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• 1998

A computer program has been developed to predict the heat transfer characteristics and the temperature distribution in the cylinder block of a 4-cylinder, 4-stroke engine. The finete element method is employed to handle the complex geometries associated with the practical cylinder block. The hexahedron finite element is used for a mesh generation of three-dimensional domain. The present numerical procedure has been validated with the measured temperature at several locations of cylinder block. The heat transfer characteristics of engine cylinder block is systematically analyzed for various engine speeds and loading conditions.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.461-464
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• 1988

In order to use mBIZ code as the practical transmission code, the information block length have to be determined. If the information block length is short, timing information disapperance is reduced, but transmission speed is increased as the result of inserted redundancy bit. While, if the information block length is long, timing information disapperance and jitter are caused. So it is very important to determine the optimal timing information block length. Therefore, in this paper, we determined the optimal information block length using S/X endurance method.