• Journal of the Korean Geotechnical Society
• /
• v.19 no.1
• /
• pp.61-75
• /
• 2003

Comprehensive review on the determination of critical state parameters in sandy soils from standard triaxial testing was performed to facilitate the application of critical state soil mechanics to the shear behavior of sandy soils. First, semantic differences in literature were clarified, inferring that critical state should be considered as the ultimate state at large deformation. Second, the characteristics of critical state parameters were discussed, and also the uniqueness of critical state line and the sensitivity of quasi-steady state condition were verified in relation to initial state, fabric, loading condition, and drainage condition. Third, as an example, the critical state soil mechanics was applied to evaluate the post-liquefaction shear strength, i.e. the reliable ultimate shear strength in liquified soils, in terms of critical state parameters.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38A no.8
• /
• pp.656-661
• /
• 2013

In Guided Scrambling (GS) encoding for the holographic storage, after scrambling augmented source word into codeword, the best codeword satisfying modulation constraint is determined. Modulation constraints considered in this paper are strength which is the minimum number of transition between '0' and '1' in each row and column of codeword array and the symbol balancedness of codeword array. In this paper, we show that GS encoding procedure can be formulated as an integer programming model and develop a fast neighborhood search heuristic for fast computation of control bits. In the simulation, we compared the performance of heuristic algorithm with the integer programming model for various array and control bit size combinations.

• 한국연소학회:학술대회논문집
• /
• 2014.11a
• /
• pp.25-28
• /
• 2014

In this study, waste cooking oil was gasified in a fluidized bed reactor. The main objective of this study was to produce clean producer gas for power generation engine. As a result, heating value of producer gas is suitable for engine operation and tar content in producer gas was satisfied after use of activated carbon filter. Results from a lab scale experiment and a preliminary results from a pilot scale experiment will be presented.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2009.11a
• /
• pp.231-234
• /
• 2009

본 논문에서는 고속 동영상 방식의 스킵 블록 예측을 이용한 변환 과정 및 양자화 과정 생략 기법에 대해 제안한다. 정수여현 변환과 양자화 과정을 이용하여 생략 가능 블록을 예측하고, 이를 이용하여 압축 효율에 영향 없이 효과적으로 양자화 생략하는 방식에 대해 기술한다. 실험 결과를 통해 제안 방식을 이용한 예측된 블록이 부가적인 계산 없이 효과적으로 예측되어 생략되었음을 확인할 수 있었다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2020.11a
• /
• pp.127-128
• /
• 2020

본 논문은 딥러닝 네트워크의 압축을 위한 양자화 오프셋의 바이어스 기법을 제안한다. 양자화는 32비트 정밀도를 갖는 가중치와 활성화 데이터를 특정 비트 이하의 정수로 압축한다. 양자화는 원 데이터에 스케일과 오프셋을 더함으로써 수행되므로 오프셋을 위한 합성곱 연산이 추가된다. 본 논문에서는 입력 활성화 데이터의 양자화 오프셋과 가중치의 합성곱의 출력은 바이어스에 임베딩될 수 있음을 보여준다. 이를 통해 추론 과정 중 오프셋의 합성곱 연산을 제거할 수 있다. 실험 결과는 오프셋의 합성곱이 바이어스에 임베딩이 되더라도 영상 분류 정확도에 영향이 거의 없음을 증명한다.

• Journal of the Korean Geographical Society
• /
• v.49 no.3
• /
• pp.423-437
• /
• 2014

Districting is a spatial decision making process to make a new regional framework for affecting human activities. Natural barriers such as rivers and mountains located within a reorganized district may reduce the efficiency of reorganized human activities. This implies that it is necessary to consider boundary characteristics in a districting process. The purpose of this research is to develop a new spatial optimization model based on boundary characteristics for districting problems. The boundary characteristics are evaluated as continuous value expressing the possibility of combining adjacent two basic spatial units rather than a dichotomous value with 1 or 0 and are defined as an objective function in the model. In addition, the model has explicitly formulated contiguity constraints as well as constraints enforcing demand balance among districts such as population and area. The boundary attributes are categorized into physical and relational characteristics. Suitability analysis is used to combine various variables related to each boundary characteristic and to evaluate the coupling possibility between two neighboring basic units. The model is applied to an administrative redistricting problem. The analytical results demonstrate that various boundary characteristics could be modeled in terms of mixed integer programming (MIP).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.10a
• /
• pp.479-482
• /
• 2011

This paper proposes a design of a ship backbone network-based on the survival and efficiency of the ship network. Currently IEC operates the standard ship network, a standard specification "IEC 61162-410 maintains the operation of the network. IEC 61162-410 offers a high stability of the ship network by using terminal equipment. But current studies are incomplete because it has been assumed that the ship's network will operate at double its current capacity. This paper analyzes the double ship backbone topology for an organization and then will summarise the minimum costs required to implement the ship backbone topology using an ILP. Also, we present an effective traffic assignment technique that uses an ILP, metaheuristic, heuristic algorism-based underlying the ship backbone network. The results by experimenting the design of the network confirmed a greter efficiency, stability and cost-effectiveness of the ship network.

• Journal of the Korean GEO-environmental Society
• /
• v.11 no.8
• /
• pp.5-14
• /
• 2010

Recent researches on the behavior of gravelly soils have been focused mainly on the relative density or on the gravel content. And some researchers presented the liquefaction behavior based on the relative density whereas others based on the gravel content of gravelly soil. However the relative densities vary with gravel content and relative density is not enough to fully express the behavior of gravelly soils. Therefore in this research state parameter which considers void ratio and effective confining pressure is introduced and Steady State Line(SSL) of gravelly soils for various gravel content are determined by undrained triaxial tests in order to express the behavior of gravelly soils. From the research the position of SSL moved downward with gravel content. And the same density of soil showed dense sand behavior or loose sand behavior depending upon the confining pressure. Especially relative density 80% of gravelly soil showed loose sand behavior under high confining pressure. However the gravelly soils with similar state parameters showed similar stress behaviors. It can bee seen that state parameter is useful tool to evaluate undrained behavior of gravelly soils. Also state parameter and undrained strength showed good correlations.

• Korean Journal of Materials Research
• /
• v.5 no.8
• /
• pp.913-920
• /
• 1995

RFe$_2$(R=rare earth) Laves Phase intermetallic compounds are one of the promising materials for magnetostrictive applications, due to large magnetostriction coefficients in the order of 10$^{-3}$ . However, because RFe$_2$intermetallic compounds have large magnetostriction constants as well as large magnetocrystalline anisotropy constants, a large external magnetic field is necessary to reach saturation magnetostriction. Hence researches on giant magnetostriction have been concentrated on producing materials exhibiting a high value of magnetostriction in a low magentic field. The main research trend of the giant magnetostriction to obtain the large value in the low magnetic filed, fortunately as the signs of magnetocrystalline anisotropy constans in RFe$_2$intermetallic compounds alternate with the rare earth metals, has been to substitute the rare earth metal for others and hence to reduce the magnetocrystalline anisotropy energy. In addition, amorphous RFe$_2$alloys have been researched. In this research, both of the methods which are substitution of the rare earth metal and amorphization in RFe$_2$ intermetallic compounds are simultaneously conducted to obtain the large magnetostriction coefficient in the low external magnetic field. Among them, SmFe$_2$and PrFe$_2$are selected, and amorphized in substrate-free bulk state. Magnetism in amorphous bulk (Sm$_{1-x}$ Pr$_{x}$) Fe$_2$alloys is investigated in the low magnetic field.ld.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.27 no.7
• /
• pp.1076-1086
• /
• 2003

The effect of a rubber mould on densification behavior of aluminum alloy powder was investigated under cold isostatic compaction. A thickness of rubber mould and friction effect between die wall and rubber mould were also studied. The hyperelastic constitutive equation based on the Ogden strain energy potential was employed to analyze deformation of rubber. The elastoplastic constitutive equation of Shima and Oyane and that of Lee on densification were implemented into a finite element program (ABAQUS) to simulate densification of metal powder for cold isostatic pressing and rubber isostatic pressing. Finite element results were compared with experimental data for densification and deformation of aluminum alloy powder under isostatic compaction.