• Journal of Mechanical Science and Technology
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• 제20권6호
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• pp.782-794
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• 2006

Classical finite element programs are not well suited to the design of composite structures, because they are primarily analysis tools and need much time for the data input and as well as for the interpretation of the results. The aim of this paper is to develop a program which allows very fast analyses and reanalyses for design process, thanks to a fast reanalysis method with changes of data and conditions. Speed in the analysis Is obtained by simplification of the analysed structure and limitations in its geometrical generality and improvements in numerical methods. The use of the program is made easy with interactive user-friendly facilities.

• 콘크리트학회지
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• 제20권2호
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• pp.25-36
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• 2008

Seismic design of reinforced concrete flat plate structures is often complicated as it deals with three dimensionality and continuous spans, and mostly material complexity and reinforcement variation. A great degree of uncertainty in such structural and material properties is thus inherent in the RC flat plate systems, and hinders simplification of the design process in terms of slab flexure, unbalanced moment transfer at a slab-column connection, and punching shear. For these reasons, there have been substantial changes and updates in building codes relating to flat plates and slab-column connections over a handful of decades. Also, for the same reason, some of codes never have been revised. As a consequence of nonsimultaneous development of each provision, it tends to confuse structural engineers when using a mixture of all different US code provisions. In this paper, in the step-by-step logical order, seismic design of the RC flat plate systems is re-organized and clarified to make it easier to apply. Furthermore, recent changes or proposed changes are introduced, and are explained as to how it will apply in practice.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2018년도 춘계 종합학술대회 논문집
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• pp.441-442
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• 2018

인터넷의 급속한 발달에 따라 다양한 앱(App)들이 기능적인 디자인으로 변모하고 있다. 그러나 아직 미적인 감성을 기반으로 한 간결성과 단순성에 대한 사용자 입장에서는 많은 불편함이 많은 실정이다. 그래서 이를 극복하기 위하여 앱을 설계할 때 사용자의 만족도도 높이면서 앱의 간결성에 영향을 미치는 요인에 대한 요소를 분석하고자 한다.

• International Journal of CAD/CAM
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• 제3권1_2호
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• pp.67-75
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• 2003

Viewpoint-dependent feature-based modelling in computer-aided design is developed for the purposes of supporting engineering design representation and automation. The approach of this paper uses a combination of a multi-level modelling approach. This has two stages of mapping between models, and the multi-level model approach is implemented in three-level architecture. Top of this level is a feature-based description for each viewpoint, comprising a combination of form features and other features such as loads and constraints for analysis. The middle level is an executable representation of the feature model. The bottom of this multi-level modelling is a evaluation of a feature-based CAD model obtained by executable feature representations defined in the middle level. The mappings involved in the system comprise firstly, mapping between the top level feature representations associated with different viewpoints, for example for the geometric simplification and addition of boundary conditions associated with moving from a design model to an analysis model, and secondly mapping between the top level and the middle level representations in which the feature model is transformed into the executable representation. Because an executable representation is used as the intermediate layer, the low level evaluation can be active. The example will be implemented with an analysis model which is evaluated and for which results are output. This multi-level modelling approach will be investigated within the framework aimed for the design automation with a feature-based model.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.406-409
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• 2006

Serviceability resign is required to control the cracking at the joint of precast decks having longitudinal prestress in continuous composite bridges. Especially, details of twin girder bridges are complex not only due to main reinforcements and transverse prestress for the resign of long-span concrete slabs but also due to shear pockets for obtaining the composite action. This paper suggests the design guidelines for the magnitude of the effective prestress and for the selection of filling materials and their requirements in order to use precast decks for twin-girder continuous composite bridges. The necessary initial prestress was also evaluated through the long-term behavior analysis. From the analysis, existing design examples were revised and their effectiveness was estimated. When a filling material having bonding strength higher than the requirement is used in the region of high negative moment, uniform configuration of longitudinal prestressing steels along the whole span length of continuous composite bridges can be achieved resulting in simplification of details and enhancement of the construction costs.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.349-352
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• 1999

In this paper, we present simplified fault set which is made by analyzing fault relation to design specification in CMOS operational amplifier. The hard fault is easily modeled because an effect of hard fault is out of all design specification. However, the soft fault is not easily modeled because an effect of soft fault on design specification is varied according to position and depth of fault. We simulated hard and soft fault by HSPICE, varying threshold voltage and W/L ratio from 90% increase to 90% decrease. The decrease of test time and the production of high reliability mixed-mode IC are possible by the proposed fault set.

• 복식
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• 제64권3호
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• pp.155-164
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• 2014

This paper discusses the social changes in the late 19th century that provided a historical background in the appearance of the ready-to-wear clothing in the West. It examines the social meanings of the appearance of the ready-to-wear clothing at the time and traces the origins of these social characteristics to the book published in the $16^{th}$ century by Thomas More, Utopia. The results of this study can be summarized as the following. First, the appearance and expansion of the ready-to-wear clothing coincided with the social transition from a class-based society to a democratic society in the west in the $19^{th}$ century. Second, uniforms were produced in the $18^{th}$ century Europe in order to distinguish different classes and ethnic groups, with the military uniforms being the most visible example. Frequent military campaigns in Europe resulted in the increasing demand and expansion of military uniforms, which later became the basis of the standardization of the men's clothing with uniforms. Third, the women's ready-to-wear clothing appeared later than their male counterpart and was made possible by the simplification of design, an important characteristic of women's wear in the later period. Fourth, the social characteristics of the ready-to-wear clothing can be traced to a democratic and egalitarian society without personal properties that was depicted in the book of Utopia by Thomas More. Fifth, one of the characteristics of the ready-to-wear clothing can be found in the description of Utopia, in which everyone in Utopia wears a clothing of the same form for life.

• Computers and Concrete
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• 제9권4호
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• pp.275-291
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• 2012

The service loads are often decisive in the design of concrete structures. The evaluation of the cracking moment, $M_{cr}$, is an important issue to predict the performance of the structure, such as, the deflections of the reinforced concrete beams and slabs. To neglect the steel bars of the section is a simplification that is normally used in the computation of the cracking moment. Such simplification leads to small errors in the value of this moment (typically less than 20%). However, these small errors can conduce to significant errors when the values of deflections need to be computed from $M_{cr}$. The article shows that an error of 10% on the evaluation of $M_{cr}$ can lead to errors over 100% in the deformation values. When the deformation of the structure is the decisive design parameter, the exact computing of the cracking moment is obviously very important. Such rigorous computing might lead to important savings in the cost of the structure. With this article the authors wish to draw the attention of the technical community to this fact. A simple equation to evaluate the cracking moment, $M_{cr}$, is proposed for a rectangular cross-section. This equation leads to cracking moments higher than those obtained by neglecting the reinforcement bars and is a simple rule that can be included in Eurocode 2. To verify the accuracy of the developed model, the results of the proposed equation was compared with a rigorous computational procedure. The proposed equation corresponds to a good agreement when compared with the previous approach and, therefore, this model can be used as a practical aid for calculating an accurate value of the cracking moment.

• 한국통신학회논문지
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• 제15권4호
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• pp.331-340
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• 1990

통신 프로토콜의 설계에 있어 설계 과정의 단순화와 설계된 프로토콜의 논리적 정당성 입증은 중요한 과제이다. 본 논문에서는 FSM을 이용한 통신 프로토콜 설계 과정 효율화를 위한 합성방법을 제안한다. 통신 프로토콜의 속성 정보를 묵시적으로 표현하여 설계 과정이 단순화되도록 기존의 FSM을 확장시켜 CFSM 을 저의한다. 통신 프로토콜의 설계자는 FSM을 이용하여 오류를 고려하지 않은 한 통신 기계 M 만을 기술하며, 동기화를 보장받는 두 통신 기계 M'과 N'이 합성되며 M'과 N'이 오류 회복 기능을 갖도록 오류 회복용 변환 규칙을 적용하여 최종 프로토콜 EM'과 EN'을 얻는다.

• 대한기계학회논문집A
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• 제38권10호
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• pp.1075-1084
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• 2014

플랜트 설계를 위해서는 기자재 카탈로그를 구축해야 한다. 기자재의 3 차원 CAD 모델은 목적에 따라 서로 다른 상세도를 가진다. 기자재 제작사는 높은 상세도를 갖는 CAD 데이터를 제공하는 반면에 플랜트 엔지니어링사는 낮은 상세도를 가지는 CAD 데이터가 필요하다. 이와 같은 문제를 해결하기 위해서 기자재 3D CAD 조립체 데이터를 자동으로 간략화하는 시스템을 개발하였다. 이 논문에서는 간략화 시스템의 구조, 상세 기능과 함께 카탈로그 생성을 위한 중립 데이터 형식을 제안한다. 그리고 프로토타입 시스템을 이용한 간략화 실험 결과를 설명한다.