• Journal of Electrical Engineering and Technology
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• v.8 no.6
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• pp.1451-1456
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• 2013

This paper presents the improved zero power levitation control algorithm for a quadruple hybrid EMS (Electromagnetic Suspension) system. Quadruple hybrid EMS system is a united form of four hybrid EMS systems one on each corner coupled with a metal plate. Technical issue in controlling a quadruple hybrid EMS system is the permanent magnet's equilibrium point deviation caused by design tolerance which eventually leads to a limited zero power levitation control that only satisfies the zero power levitation in one or two hybrid EMS system among the four hybrid EMS system. In order to satisfy a complete zero power levitation control of the quadruple hybrid EMS system, the proposed method presented in this paper adds a compensating algorithm which adjusts the gap reference of each individual axe. Later, this paper proves the stability and effectiveness of the proposed control algorithm via experiment and disturbance test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.6
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• pp.1256-1264
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• 2009

When unapproved users access to healthcare system and use medical information for other malicious purposes, it could severely threaten important information related to patients' life, because in ubiquitous environment healthcare service makes patient's various examination results, medical records or most information of a patient into data. Therefore, to solve these problems, we design RBAC(Role Based Access Control) for U-healthcare that can access control with location, time and context-awareness information like status information of user and protect patient's privacy. With implementation of the proposed model, we verify effectiveness of the access control model for healthcare in ubiquitous environment.

• The Journal of Information Systems
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• v.20 no.2
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• pp.1-20
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• 2011

In this study, we verify the relationship, which is presented by ISO/IEC 15504, between the assessor's competence and the efficiency of assessment. The ISO standard has been developed by many formal trial experiences for the software process assessment. The software process assessment determines the process capability, and makes the software process improvement possible in the development cycle. In the field assessment, third-party and team-based assessments are generally recommended. Therefore assessors' competences are essential to achieve the effectiveness and the efficiency of assessment. Survey data are collected from the third-party process assessment of a real IT industry, and the analysis is done by a causal modelling technique - PLS. Some findings are as follows. Depending on assessors' SE experiences, effects of the assessor's competence are existed, and their standard knowledge and assessment skill are effected each other. And the efficiency of assessment depends on the assessor's competence. In addition, the power analysis is presented and future research is suggested, because of many limitations of this study.

• The Journal of Korean Academic Society of Nursing Education
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• v.19 no.4
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• pp.675-683
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• 2013

Purpose: Nineteen articles were analyzed to gather opinions and nursing implications about NIPT recently launched. Methods: Nineteen articles were selected from EBSCO (eBook business collection), Google Scholar, and two Korean academic d-bases with key words 'prenatal screening testing', 'prenatal genetic diagnostic testing', NIPT or 'cell free DNA (cfDNA)'. Authors developed a framework for analyzing the 19 articles including opinions and suggestions for future implications. Results: Eleven articles written by the first author affiliated with medicine or genetics, viewed NIPT as promising because of safety, accuracy, early detectability and cost effectiveness. Articles written by journalists or authors affiliated with history and ethics were concerned with the possible risk of ELSI (ethical, legal, social issues), erratic interpretation of test results, and lack of genetic counseling service. Conclusion: With consideration of Korean clinical, and legal circumstances, not only pregnant women and families but also health professionals must prepare for clinical NIPT implications including updating prenatal genetic testing, counseling services, protecting ELSI and amulticultural team approach.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.6
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• pp.546-552
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• 2012

This paper presents an active anti-islanding detection method using negative sequence voltage injection to the grid through a three-phase photovoltaic inverters. Because islanding operation mode can cause a variety of problems, the islanding detection of grid-connected photovoltaic inverter is the mandatory feature. The islanding mode is detected by measuring the magnitude of negative sequence impedance calculated by the negative sequence voltage and current at the point of common coupling. Simulation and experimental test are performed to verify the effectiveness of the proposed method which can detect the islanding mode in the specified time. The test has been done in accordance with the condition on IEEE Std 929-2000.

• Journal of the Korean Society of Industry Convergence
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• v.19 no.3
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• pp.109-124
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• 2016

The objective of this paper is to find the density, stiffness, and strength of truss-wall diamond corrugation model combined with pinwheel truss inside space. The truss-wall diamond corrugation (TDC) model is defined as a unit cell coming from solid-wall diamond corrugation (SDC) model. Pinwheel truss-wall diamond corrugation (P-TDC) model is made by TDC connected with pinwheel structure inside of the space. Derived ideal solutions of P-TDC is based on truss-wall and pinwheel truss model at first. And then it is compared with Gibson-Ashby's ideal solution. To validate the ideal solutions of the P-TDC, ABAQUS software is used to predict the density, strength, and stiffness, and then each of them are compared to the ideal solution of Gibson-Ashby with a log-log scale. Applied material property is stainless steel 304 because of having cost effectiveness. Applied parameters for P-TDC are 1 thru 5 mm diameter within fixed opening width as 4mm. In conclusion, the relative Young's modulus and relative yield strength of the P-TDC unit model is reasonable matched to the ideal expectations of the Gibson-Ashby's theory. In nearby future, P-TDC model is hoped to be applied to make sandwich core structure by advanced technologies such as 3D printing skills.

• Journal of the Korean Society of Industry Convergence
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• v.19 no.3
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• pp.133-143
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• 2016

The objective in here is to find the density, stiffness, and strength of truss-wall rectangular (TWR) model which is combined with lattice truss (MLT) inside space. The TWR unit-cell model is defined as a unit cell originated from a solid-wall rectangular (SWR) model and it has an empty space inside. Thus, the empty space inside of the TWR is filled with lattice truss model defined as TWR-MLT. The ideal solutions derived of TWR-MLT are based on TWR with MLT model and it has developed by Gibson-Ashby's theory. To validate the ideal solutions of the TWR-MLT, ABAQUS software is applied to predict the density, strength, and stiffness, and then each of them are compared with the Gibson-Ashby's ideal solution as a log-log scale. Applied material property is stainless steel 304 because of cost effectiveness and easy to get around. For the analysis, SWR and TWR-MLT models are 1mm, 2mm, and 3mm truss diameter separately within a fixed 20mm opening width. In conclusion, the relative Young's modulus and relative yield strength of the TWR-MLT unit model is reasonably matched to the ideal expectations of the Gibson-Ashby's theory. In nearby future, TWR-MLT model can be verified by advanced technologies such as 3D printing skills.t.

• Women's Health Nursing
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• v.12 no.4
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• pp.316-325
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• 2006

Purpose: The purpose of this study was to develop a Critical Pathway for Uterine Artery Embolization patients. Method: There were 6 steps that were taken. Step 1 was selecting a diagnosis, and Step 2 was organizing a development team consisting of 7 experts. Step 3 analyzed the medical records, and Step 4 drew up a preliminary Critical Pathway. Step 5 tested the clinical validity of the preliminary Critical Pathway, and Step 6 developed the final Critical Pathway. Result: The contents of the medical practices observed in the medical records were investigated in seven areas: monitoring/assessment, treatment, medication, diet, activity, consults, and education/discharge plan; and a total of 73 items was identified. The validity of the 73 items was examined by a group of specialists. 68 items were adopted, 4 items revised, 1 item removed, and 1 item was added. Using the results, a preliminary Critical Pathway was drawn up. According to the results from examining the clinical validity of the preliminary Critical Pathway with five patients for five weeks, 3 items which showed discrepancy were revised and another 3 items were added. Then, the final Critical Pathway was completed. Conclusion: This Critical Pathway needs to be clinically applied and continuously to measure its effects in terms of the length of stay, cost.effectiveness, and the patients' and staffs' satisfaction.

• Journal of Sensor Science and Technology
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• v.7 no.1
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• pp.23-30
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• 1998

In this paper, we analyzed the effect of the time delay of the image sensor in the tracking loop of Electro-Optical Tracking System(EOTS). we showed that Smith predictor can greatly improve the stability and various performances of EOTS with time delay. And also, to verify the realistic validity, we executed the experiment in EOTS recently developed, and confirmed the effectiveness in EOTS.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.7
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• pp.517-524
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• 2014

Micro-vibration induced by on-board equipments such as fly-wheel and cryogenic cooler with mechanical moving parts affects the image quality of high-resolution observation satellite. Micro-vibration isolation system has been widely used for enhancing the pointing performance of observation satellites. In general, the micro-vibration isolation system requires a launch locking mechanism additionally to guarantee the structural safety of mission payloads supported by the isolation system with low stiffness under launch environment. In this study, we propose a passive launch and on-orbit vibration isolation system using shape memory alloy mesh washers for the micro-vibration isolation of spaceborne compressor, which does not require the additional launch locking mechanism. The basic characteristics of the isolator were measured in static and free vibration tests of the isolator, and a simple equivalent model of the isolator was proposed. The effectiveness of the isolator design in a launch environment was demonstrated through sine vibration, random vibration and shock tests.