• Asia pacific journal of information systems
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• 제9권1호
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• pp.193-209
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• 1999

Developing Information Systems is a process of decomposing the entire systems into sub systems and identifying a hierarchical structure among the sub systems. Diagrammatic representation of hierarchy is an essential part of systems development since the identified hierarchical structures are usually presented in diagrams. The main goal of this research is to identify the most effective ways of representing system structures using diagrams. In order to achieve the main goal, this study performed three phases of research. In the first step, a theoretical model was constructed to conceptually explain users' comprehension on diagrams. Then visual factors of diagrammatic representations were identified based on the diagrams used in systems development. Finally, three consecutive experiments were conducted to identify the impacts of visual factors on the level of users' comprehension. The results indicate that familiarity and affordance of diagrams affect the degree of comprehension about the diagrams, which is in turn influenced by the complexity of tasks and the types of hierarchies. This paper concludes with the limitations of the study results and implications in the development of information systems.

• KDI Journal of Economic Policy
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• 제43권3호
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• pp.1-32
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• 2021

With CB data in South Korea, this study examines whether the credit risk of borrowers changes when the regulation on bank mortgage supply is relaxed. We analyze the effect of deregulation on LTV and DTI limits in the Seoul-metropolitan area in August 2014 with a difference-in-difference approach. We find that the probability of delinquency is lower in the Seoul metropolitan area after the deregulation than in other urban areas. The effect is noticeable among low-income and low-credit borrowers. We also find that borrowers change their debt structure to reduce the interest costs utilizing their improved access to bank mortgages. The findings suggest the necessity to consider the burden of the high interest costs of unsecured loans for debtors with low incomes and low credit ratings in designing housing finance regulations.

• 전자통신동향분석
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• 제33권6호
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• pp.139-153
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• 2018

The explosive interest in block chain, which was triggered by Bitcoin in 2009, is leading to substantial investment and the development of block chain technology. There is no dispute among experts that block chain will be the next generation of innovation. However, despite the high expectations for block chains, the related technology still has certain limitations. In addition to improving issues such as a low transaction throughput, inefficient agreement algorithms, and an inflexible governance structure, it is necessary to solve various problems for commercialization and full-scale spreading owing to the trilemma problem among the scalability, security, and decentralization. Under this situation, identification of the technology characteristics according to the generation is helpful for the development of the core technology requirements and commercialization blueprint in establishing an R&D direction. Therefore, in this article, the development of blockchain technology is divided into generations and analyzed in terms of the operational structure, consensus algorithm, governance, scalability, and security.

• 수산해양기술연구
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• 제44권2호
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• pp.99-111
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• 2008

The purpose of this study is to develop the jellyfish separator system(JSS) for reducing fishery damage by the increase of jellyfish in the sea area of Korea in summer. First of all, to find the optimum structure of a JSS, six types of JSS in trawl fishery were designed and manufactured, the underwater shape of JSS and the separating process by JSS were observed in the circulating water channel(CWC). And the field experiments were carried out in July and September 2004 in the southern sea of Korea. For the moving path of the jellyfish model in the CWC, in case that the model was larger than the mesh size of the separator net, it was guided toward the lower part of the separator net by the guiding net and discharged through the outlet. In case that the model was smaller than the mesh size of the separator net, some models which passed through the upper part of the guiding net were smaller than the mesh size of the guiding net and discharged through the outlet and most of the model which passed through the lower part of the guiding net moved to the codend passing through the separator net. According to the field experiment result, the optimum tilt angle of separator net was inferred $20^{\circ}$ that the discharge rate of jellyfish was higher than the other tilt angle of separator net and the optimum structure of JSS was inferred GS type(consists of guiding net and separator net) that the discharge rate of jellyfish was higher than S type(consists of separator net). It was demamded to carry out more study for the countermeasure to reduce loss of fish.

• 분석과 대안
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• 제6권1호
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• pp.195-222
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• 2022

From the economic development perspective, economic growth should accompany structural improvement in order to meet complex demands from a society. In the context of development economics, economic growth is critically dependent on successful structural advancement. The issue of structural change is also important for advanced economies as the landscape of modern industry is changing fast. Many advanced countries of slow growth are experiencing dawdling changes in industry structure. However, there is no definitive answer to the question of whether there is a causal relationship between structural change and growth. This study empirically assesses the relationship between structural change or 'speed' thereof and economic growth in developed countries of OECD. Rather than looking into the causes of structural changes, this study simply measures structural changes in OECD economies and examines if structural change is really contributing to growth. The reason why this study focuses on advanced countries of OECD is rather obvious; technological innovation and emergence of new industries pressure these countries to restructure their economies to address these new challenges though they are at stages well beyond conventional industrialization. And structural rigidity can always limit growth even in advanced countries. The main results of this study can be summarized as a positive relationship between 'change and growth'. 'Change' in this study refers to changes in the industrial structure based on value-added and was analyzed to have a close positive relationship with economic growth. This result is consistent with arguments of early development economists emphasizing structural upgrade as an indispensable process for growth and development. The result of this study potentially confirms that the main argument of development economics is valid also for advanced economies. One of our results suggests that business/professional services and social services should be main targets for restructuring for advanced economies. The rational may be that rapid convergence of manufacturing and services is a key for structural advancement in the era of new technologies. Obviously, as manufacturing technology and production are standardized, it is difficult to secure international competitiveness through traditional manufacturing alone and the role of R&D, design, logistics, and marketing is becoming more important.

• 한국농공학회논문집
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• 제58권3호
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• pp.13-19
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• 2016

Element-focused network analysis method for truss structure is proposed. The propagation process of loads from external loads to connected other elements is similar to that of connections between nodes in accordance with attachment rule in a network. Here nodes indicate elements in a truss structure and edges represent propagated loads. Therefore, the flows of loads in a truss structure can be calculated using the network analysis method, and consequently the structure can also be analyzed. As a first step to analyze a truss structure as a network, we propose a local load transfer rule in accordance with the topology of elements, and then analyze the loads of the truss elements. Application of this method reveal that the internal loads and reactions caused by external loads can be accurately estimated. Consequently, truss structures can be considered as networks and network analysis method can be applied to further complex truss structures.

• 대한기계학회논문집A
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• 제28권6호
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• pp.726-731
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• 2004

This paper suggests a material mixing method to mix several materials in a structure. This method is based on ESO(Evolutionary Structural Optimization), which has been used to optimize topology of only one material structure. In this study, two criterions for material transformation and element removal are implemented for mixing several materials in a structure. Optimal topology for a multiple material structure can be obtained through repetitive application of the two criterions at each iteration. Two practical design examples of a short cantilever are presented to illustrate validity of the suggested material mixing method. It is found that the suggested method works very well and a multiple material structure has more stiffness than one material structure has under the same mass.

• 한국생산제조학회지
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• 제8권1호
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• pp.142-149
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• 1999

A machine frame has been manufactured by casting. However, due to the development of the industrial society, 3-D duties was refused. Especially, the declination of the casting industry makes it difficult to produce the frame. Many companies still manufacture the small casting products. The large casting products are extremely limited and manufactured for their own use. Therefore, it is difficult to keep the term of order. In this study, the characteristics of steel structure which is produced by welding were identified in the view of mechanical strength of steel structure which is produced by welding were identified in the view of mechanical strength to substitute steel structure for casting frame. But welding structure has the residual stress, HAZ and welding deformation. Residual stress and HAZ especially cause crack growth. The proposed steel structure, based on the simulation and experiment(tensile curve and S-N curve), can reduce not only the producting term but also the weight of the frame.

• 한국전기전자재료학회논문지
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• 제19권4호
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• pp.328-333
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• 2006

In this paper, we developed a pressure measurement apparatus with the parallel structure to improve the measurement efficiency of pressure sensors by reducing the measurement time of pressure. The developed system has two parallel positions for loading Silicon pressure sensor and has a dual valve structure. The semiconductor pressure sensors prepared by Copal Electronics were used to confirm the performance of the developed measurement system. Two stage differential amplifier circuit was employed to amplify the weak output signal and the amplified output signal was improved utilizing a low-pass filter. New apparatus shows the measurement time of pressure two times shorter than that of conventional one with the serial structure, while both structures show the similar linear output versus pressure characteristics.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 추계학술대회
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• pp.259-264
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• 2003

This paper suggests a material mixing method to mix several materials in a structure. This method is based on ESO(Evolutionary Structural Optimization), which has been used to optimize topology of only one material structure. In this study, two criterions for material transformation and element removal are implemented for mixing several materials in a structure. Optimal topology for a multiple material structure can be obtained through repetitive application of the two criterions at each iteration. Two practical design examples of a short cantilever are presented to illustrate validity of the suggested material mixing method. It is found that the suggested method works very well and a multiple material structure has more stiffness than one material structure has under the same mass.