• Journal of Power Electronics
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• v.17 no.5
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• pp.1256-1267
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• 2017

A fault tolerant structure and its corresponding control strategy for electromagnetic stirring power supplies are proposed in this paper. The topology structure of the electromagnetic stirring power supply contains two-stages. The fore-stage is the PWM rectifier. The back-stage is the fault tolerant inverter, which is a two-phase three-bridge orthogonal inverter circuit while operating normally. When the power switch devices in the inverter are faulty, the structure of the inverter is reconfigured. The two-phase half bridge inverter circuit is constructed with the remaining power switch devices and DC-link capacitors to keep the system operating after cutting the faulty power switch devices from the system. The corresponding control strategy is proposed to let the system work under both normal and fault conditions. The reliability of the system is improved and the requirement of the electromagnetic stirring process is met. Finally, simulation and experimental results verify the feasibility of the proposed fault tolerant structure and corresponding control strategy.

• Journal of Internet Computing and Services
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• v.3 no.2
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• pp.57-67
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• 2002

The main goal of this paper is to establish the management network structure by adopting TMN concept. Hence, the management network structure consists in layers; from management application layer to lower physical layer In this paper, TMN-DCN structure is designed. That means, since the current communication network technology has developed so fast and new and more diverse communication networks have appeared, There is a need to process each management information in fast manner, The design method of management network physical structure that enhances the efficiency in network management with prompt transmission and reception of management information is proposed and the architecture is designed as well. Although there is some increase in installation fee for total link that constitutes the physical structure in lower physical layer. network management can be promptly implemented since the structure that can transfer the management information fastest is proposed.

• Journal of the Korean GEO-environmental Society
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• v.22 no.3
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• pp.31-35
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• 2021

The expansion joints installed on the bridge for the accommodation of expansion and contraction of the supper structure are essential members of the bridge. However, the expansion joints are deteriorated over time and the waterproof function weakens, causing rainwater to penetrate and deteriorate the structure. In order to solve the traffic congestion caused by frequent replacement of the old expansion joints along with the deterioration of the structure, a post-integrated abutment bridge in which the existing expansion joints are removed and replaced with reinforced concrete link connection has been applied to highway bridges since 2016. After the post-integrated abutment method was applied, it was partially applied to bridges in which the superstructure and abutment were jammed. In this study, the causes of problems that may occur when the post-integrated abutment method is applied to the jammed bridge were analyzed numerically. It was analyzed that damage occurred in the link connection part. Based on the results of this study, the application condition for the post-integrated abutment method is reinforced as it is not possible to apply the post-integrated abutment method to bridges are already jammed.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.4
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• pp.163-170
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• 2017

As the usage of smart phones continues to increase, the control UI, which users have to continue to use, sometimes finds a heavy burden on users. Therefore, in this study, we have studied the control user interface structure along with the theoretical background of the control user interface, and we have studied the role and usage of the control component based on it. Typical commonly used controls are button controls for transmission, selection controls for various selections, link controls for navigation, text controls for inputting characters, indicator controls for feedback on progress, A message control that displays information about warnings and errors, and a window control such as a dialog box. The structure of the control should be designed according to the use of the separated control to help the user efficiently use the control user interface. Based on the analysis of the theoretical usage of representative components belonging to the separated controls, we presented a new and correct way to use the control to improve the user experience. The use of improved control components will help to design the control structure efficiently and to improve the user experience.

• The Journal of Korean Academic Society of Nursing Education
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• v.10 no.1
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• pp.54-63
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• 2004

The purpose of this study is to identify the factors that influence stress experienced by nursing students and to provide a perceived causal structure model among these variables. The ultimate goal of this study is to develop efficient guidance to clinical nursing education in this population. This study intends to apply perceived causal structure: network analysis method which was developed by Kelly(1983), and has been applied in nursing research. This method is selected to show dynamic relationship of stressor using network method. Data was collected from convenient sample of 186 junior college nursing students who had the clinical practice experience during 10 weeks. Data collection and analysis was conducted in 2 steps from December, 9, 2002 to February, 8, 2003. Step 1.: Data was collected using literature review(10 articles) to identify the causes of stress. Nine causes of stress were extracted. Step 2.: As perceived casual structure network study, data was collected using questionnaires which included 9 extracted cause and stress. The questionnaire contained a 10 X 10 grid table with 10 causes and effects printed. In network analysis, 'Yes' was scored as 1, 'No' was scored as 0, and the mean(maximum 1, minimum 0) was calculated. Construction of the network under inductive eliminative analysis which stopped the construction of the network when the consensual agreement level dropped near 50% was proceeded by adding causes in order of the mean rating level. In this study, construction of the final network was stopped by consensual agreement level of 52% of the total subjects. The results are summarized as follows : Step 1: Investigation of the causes of stress ; The extracted causes of stress from quality data was identified 9 categories ; negative nurse, lack of clinical practice opportunity, ambiguous role, negative patient, lack of nursing knowledge and skill, difficult of personal relations, inefficient clinical practice guidance, gap of theory and practice, lack of support. Step 2 : Construction of the perceived causal structure model ; 1) The most central cause of stress is ambiguous role in the systems of causation. 2) The distal cause of stress is inefficient clinical practice guidance 3) The causes that have a number of outgoing link are negative nurse, ambiguous role. 4) The causes that have a number of incoming link are ambiguous role, gap of theory- practice, lack of clinical practice opportunity, lack of nursing knowledge- skill. 5) There is a mutual relationship between stress and difficult of personal relations, stress and ambiguous role, ambiguous role and negative nurse, ambiguous role and lack of clinical practice opportunity, ambiguous role and lack of nursing knowledge-skill, lack of nursing knowledge-skill and gap of theory- practice. In conclusion, the network suggests that the first centre cause is related on ambiguous role and the second on negative nurse, inefficient clinical practice guidance in the systems of causation

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.702-708
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• 2018

3D printing technology is attracting increasing attention as a key technology of the fourth industrial revolution that can change the production paradigm of existing industries. The introduction of construction 3D printing technology has been slower than other industries because of the characteristics of the construction field. On the other hand construction automation using 3D printing is required to reduce the production population, as well as improve productivity and safety. In this study, a construction 3D printing work breakdown structure and link method to a standard estimation system were developed as a preliminary preparation for introducing 3D printing to construction. Based on expert consultation on construction and 3D printing, a hypothetical scenario was developed based on existing construction 3D printing technology. According to the scenario, 16 kinds of works required for 3D printing construction work were derived. The existing work breakdown structure and standard estimation system were analyzed, and the 3D printing work was linked. 3D printing works that were the same as the existing breakdown structure were found, and non-existent works were added to the similar breakdown structure. These results are expected to be helpful for future 3D printing construction management and cost estimation. The actual standard estimation system through 3D printing work will need to be calculated.

• Journal of the Korean Mathematical Society
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• v.38 no.6
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• pp.1167-1177
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• 2001

The groups generated by reflections in faces of Coxeter polyhedra in three-dimensional Thurstons spaces are considered. We develop a method for finding of finite index subgroups of Coxeter groups which uniformize three-dimensional manifolds obtained as two-fold branched coverings of manifolds of Heegaard genus one, that are lens spaces L(p, q) and the space S$^2$$\times$S$^1$.

• Journal of the Chungcheong Mathematical Society
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• v.19 no.4
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• pp.349-356
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• 2006

The aim of this paper is to endow a monoid structure on the set S of all oriented knots(links) under the operation ${\biguplus}$, called addition of knots. Moreover, we prove that there exists a homomorphism of monoids between ($S_d,\;{\biguplus}$) to (N, +), where $S_d$ is a subset of S with an extra condition and N is the monoid of non negative integers under usual addition.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.11
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• pp.31-35
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• 1992

This paper presents a decentralized adaptive controller design for a robot manipulator to track the given desired trajectory in the joint space. The controller is of distributed structure and does not require the complex manipulator dynamic model, thereby it is computationally very efficient. Each joint is independently controlled by a PID feedback part and a velocity-acceleration feedforward part. Simulation results for a two-link direct drive manipulator conform that the proposed decentralized scheme is feasible.

• Biomolecules & Therapeutics
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• v.19 no.3
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• pp.267-273
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• 2011

Syndecans are membrane-anchored proteoglycans and implicated in the pathogenesis of cancer progression and metastasis. Syndecans also play important roles in interacting with growth factors, extracellular matrix and other cell surface molecules such as IGF-1 receptor. In the present review, we discuss about the syndecan structure, their role in signaling with other receptors, in addition to its general biology. The emerging roles of syndecans in the pathophysiology of human diseases, especially insulin resistance, diabetes and cancer is discussed.