• Journal of Korean Society of Steel Construction
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• v.17 no.2 s.75
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• pp.243-251
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• 2005

The fracture mechanics analysis of a crack in a weld must consider residual stress generated during welding. The standard definition of the J-integral requires a path dependent value in the presence of a residual stress field. Therefore, it is necessary to develop a path independent J-integral definition for a crack in a residual stress field. This paper addresses the modification of the Rice-J-integral to produce a path- independent J-integral when residual stresses and external forces are present. The residual stress problem is treated as an initial strain problem and the J-integral proposed for this type of problems is used. A program which can evaluate the J-integral for a crack in a weld is developed using the proposed J-integral definition. The situation when only residual stress is present is examined as is the case when mechanical stresses are applied in conjunction with a residual stress.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.17 no.4
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• pp.423-431
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• 2004

For the fracture mechanics analysis of cracks in welds of dissimilar steels, residual stress analysis and fracture analysis must be performed simultaneously. The standard definition of the J -integral leads to a path dependent value in the presence of a residual stress field. And unlike cracks in homogeneous materials, a bimaterial interface crack always induces both opening and shearing modes of stress in the vicinity of the crack tip. Therefore, it is necessary to develope a path independent J-integral definition for a crack in a residual stress field generated by welding of dissimilar steels. This paper addresses the modification of the Rice-J-integral to produce a path independent J -integral when residual stresses due to welding of dissimilar steels and external forces are present. The residual stress problem is treated as an initial strain problem and the J-integral proposed for this class of problems is used. And a program which can evaluate the J -integral for a crack in a weld of dissimialr steels is developed using proposed J integral definition.

• Computers and Concrete
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• v.14 no.4
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• pp.445-462
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• 2014

To solve structural optimization problems, it is necessary to integrate a structural analysis package and an optimization package. There have been many packages that can be employed to analyze reinforced concrete plane frames. However, because most structural analysis packages suffer from closeness of systems, it is very difficult to integrate them with optimization packages. To overcome the difficulty, we proposed a possible alternative, DAMDO, which integrates Design, Analysis, Modeling, Definition, and Optimization phases into an integration environment as follows. (1) Design: first generate many possible structural design alternatives. Each design alternative consists of many design variables X. (2) Analysis: employ the structural analysis software to analyze all structural design alternatives to obtain their internal forces and displacements. They are the response variables Y. (3) Modeling: employ artificial neural networks to build the models Y=f(X) to obtain the relationship functions between the design variables X and the response variables Y. (4) Definition: employ the design variables X and the response variables Y to define the objective function and constraint functions. (5) Optimization: employ the optimization software to solve the optimization problem consisting of the objective function and the constraint functions to produce the optimum design variables. The RC frame optimization problem was examined to evaluate the DAMDO approach, and the empirical results showed that it can be solved by the approach.

• Journal of the Korean Society of Systems Engineering
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• v.10 no.1
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• pp.33-41
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• 2014

New design concept of Reactor Coolant System (RCS) including a reactor assembly for the SMR is introduced in this work. An exploration of new type of reactor that is advanced from proposed SMRs is performed by using systems engineering approach. In this point of view project structured on three main phases; needs analysis (NA), concept exploration (CE), and concept definition (CD). Main objectives as an output of the CE stage are a small size, low cost, shortening the schedule, and enhancing safety. The SMRs usually have a small size requirement. In order to meet the size requirement and to achieve a productivity, in other words, easiness to manufacture, this paper suggests an integrated PWR design concept through researching predecessors. Although the integrated PWR concept provides many advantages, it has disadvantages that composite of maintenance and a low availability problem. Therefore, this paper comes up with a run-to-fail design concept based on modular design to address the maintenance problem and to maximize the availability of SMRs as well as to be compatible with the overall-SMRs including Barge Mounted(BM)type.

• Journal of Educational Research in Mathematics
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• v.8 no.2
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• pp.495-507
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• 1998

This article intends to review what problems the terms in calculus have and how those problems are caused. For this purpose We make examinations on the considerations in the analysis of mathematical terminology, which includes the problems of general and technical terms, the meaning and the boundary of words, their consistency, the name and meaning, concept and their concept images, translations and qwerty effects. And in chapter 3, We analyse the textbook which are currently used, through which I was able to find out that the terms in calculus have some problems, In other words, the key terms such as "differentiable", "differential coefficient", "differential" have their roots in the term "differential" but the term "derived function" is very distinct from other terms and thus obstructs the consistency of terms. And the central term "differential" is being used without clear definition. In particular, the fact that "differential", when used in its arbitrary definition, has the image of "splitting minutely" can be an obstacle to understanding the exact concepts of calculus. In chapter 4, We make a review on the history of calculus and the term "differential" currently used in modern mathematics so that I can identify the origin of the problem connected with the usage of the term "differential". We should recognize the specified problems and its causes and keep their instructional implications in mind. Furthermore, following researches and discussions should be made on whether the terminology system of calculus should be reestablished and how the reestablishment should be made.e terminology system of calculus should be reestablished and how the reestablishment should be made.

• International Journal of Contents
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• v.15 no.2
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• pp.53-58
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• 2019

The aim of this paper is to discuss how designers lead and direct 'technology-driven society' using their creative communication skill. To this end, it is required for communication designers to take conscious steps to recognize the future direction of their profession. Despite the advancement in technology, there is a human being at the center of all design activities. From a certain point of view, contemporary communication design takes an open-ended exploration of the subject matter, rather than a finished output. The notion of creative leadership may potentially expand more in terms of improving the methodology of today's visual culture. The paper will examine creative leadership that could be proposed by the challenge of discourse upon the upcoming industrial revolution. Today, communication designers are confronted by new leadership opportunities and challenges. Some leading designers seem to focus on brand new media technologies to prepare the 4th industrial revolutions. However, communication design cannot be discussed in the medium but can be understood as a process. Top-down and bottom-up process is always a concerned about the relationship since the focus of leadership has changed. In the top-down process, the leadership has existed between 'designer and client' because designers have played their role as a problem solver. On the other hand, there is a different model of leadership between 'design and technology' based on bottom-up process, which stem from the design authorship. In this regard, the new definition of creative leadership in the $4^{th}$ industrial revolution proposes a designer as a problem-finder based on the relationship between the 'designer and the public'.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.9-18
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• 2002

A capital investment problem is essentially one of determining whether the anticipated cash Inflows from a proposed project are sufficiently attractive to invest funds in the project. The net present value(NPV) criterion and internal rate of return(IRR) criterion are widely used as means of making investment decisions. A positive NPV means the equivalent worth of the inflows is greater than the equivalent worth of outflows, so, the project makes profit. Business people are familiar with rates of return because they all borrow money to finance ventures, even If the money they borrow is their own. Thus they are apt to use the IRR in preference to the NPV. The IRR can be defined as the discount rate that causes the net present value of a cash flow to equal zero. Why the project are accepted if the project's IRR is greater than the investor's minimum attractive rate of return. Against the NPV, the definition cannot distinctly explain the concept of the IRR as decision criterion. We present a new definition of the IRR as the ratio of profit on the invested capital.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.2
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• pp.44-49
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• 2007

An agent is an abstract unit for problem solving in the field of distributed artificial intelligence, and an agent-based system is designed and implemented based on the definition of agent as its central concept. Agent modeling is advantageous to abstraction, disintegration and structuring for describing complex system, so its application is increased in various areas including air traffic control, power transmission, e-commerce and medicine. There is no agreed definition of agent but agents have common points as follows: autonomy, reactivity, pro-activeness and cooperation. An agent-oriented modeling is an approach of a concept different form existing object-oriented modeling. This study proposed the agent application for E-Beam manufacturing system. To evaluate the performance of the proposed process design, we used the JADE library. The JADE toolkit provides a FIPA-compliant agent platform and a package to develp Java agents. It provides a basic set of functionalities that are regarded as essential for an autonomous agent architecture.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3159-3168
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• 2014

Interevent Time Definition(IETD) is essential in CSOs(Combined Sewer Overflows) tank design for the treatment of non-point source pollution. However, existent rainfall analysis can not calculate total amout of non-point source pollution. For deviding continuous rainfall events, therre are several IETD calculating methods. In this research, After calculate IETD by existents methods, problem of results is identified as existents method. To supplement these problems, new method using exponential decay function is suggested. The confidence range of ${\lambda}$ is estimated.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.4
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• pp.183-190
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• 1996

The purpose of this paper is to show that the solutions of the problem for the anaphor ocured in korean senstence, by means of one-direction activated chart parsing leaded by a head. This is the phenomenon frequently occured in the conversation of natural language and the part necessarily required in the construction of natural language processing system for the practical use. To solve the problem of anaphor in the korean language, we have computerized definition and the management conditions necessary in the semantic classification between the anaphor and its antecedent and index are added in the feature structure in lexicon. To deal with anaphor in parser and algorithm is proposed to solve the problem for anaphor. The range of management of pareser is extended to solve the problem for anaphor of the indeclinable parts of speech in korean occured in all the sentences the parser HPSG developed previously manages.