• Investigative Magnetic Resonance Imaging
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• v.20 no.3
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• pp.152-157
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• 2016

Purpose: Operating room management is the serious and complex task for hospital managers and the common approach is to develop relevant standard operational procedures. From patient and staff safety perspective, operating room management should be well-studied and hospital should identify and address any potential risks. Simultaneous usage of different imaging and less-invasive treatment technologies demands strong management control. Materials and Methods: We have formed the multidisciplinary expert panel (surgeons, anesthesiologists, radiologists, healthcare managers etc.) for hybrid theater management standard operational procedure development. On the first stage the general concept of hybrid room design and patient routing was developed. The second stage included the technical details discussion. For patient safety improvement we modified the Surgical Safety Check-list in accordance with potential MRI-related safety challenges and concerns. Results: WHO Surgical Safety Checklist is a simple and easy-to use tool which includes three blocks of question (grouped by the surgery process). We have developed two additional blocks of questions for the intraoperative magnetic resonance investigation. It is very important to have a special detailed routing with a strong control of ferromagnetic devices and anesthesiology care. Conclusion: High-energy MRI (1.5-3.0T) is characterized by potential influence on patient and staff safety in case of hybrid surgery. It is obvious to have a strong managerial control of ferromagnetic devices and anesthesiology care. Surgical Safety Checklist is the validated tool for improving patient safety. Modification and customization of this check-list potentially provides the opportunity for surgery processes improving.

• The Journal of Korea Robotics Society
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• v.11 no.3
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• pp.183-192
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• 2016

Generating motion of center of mass for biped robots is a challenging issue since biped robots can easily lose balance due to limited contact area between foot and ground. In this paper, we propose force control method to generate high-speed motion of the center of mass for horizontal direction without losing balancing condition. Contact consistent multi-body dynamics of the robot is used to calculate force for horizontal direction of the center of mass considering balance. The calculated force is applied for acceleration or deceleration of the center of mass to generate high speed motion. The linear inverted pendulum model is used to estimate motion of the center of mass and the estimated motion is used to select either maximum or minimum force to stop at goal position. The proposed method is verified by experiments using 12-DOF torque controlled human sized legged robot.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.73-76
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• 2003

A zero voltage soft switching inverter using active clamp is presented for induction heating application. This converter have long been attractive because of its simplicity, high efficiency, and low cost compared to other schemes. In addition to those merits, Input power factor can be improved with a variable frequency control. In this paper, it describe the control method and operational principle to improve a power factor with a single stage US converter using active clamp for induction heating application.

• Earthquakes and Structures
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• v.15 no.3
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• pp.263-273
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• 2018

Operational modal analysis is being widely used in aerospace, mechanical and civil engineering. Common research fields include optimal design and rehabilitation under dynamic loads, structural health monitoring, modification and control of dynamic response and analytical model updating. In many practical cases, influence of noise contamination in the recorded data makes it difficult to identify the modal parameters accurately. In this paper, an improved frequency domain method called Enhanced Least Square Complex Frequency (eLSCF) is developed to extract modal parameters from noisy recorded data. The proposed method makes the use of pre-defined approximate mode shape vectors to refine the cross-power spectral density matrix and extract fundamental frequency for the mode of interest. The efficiency of the proposed method is illustrated using an example five story shear frame loaded by random excitation and different noise signals.

• Journal of Distribution Science
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• v.12 no.9
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• pp.113-123
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• 2014

Purpose - After Korea's Free Economic Zone (FEZ) system was launched in 2003, there have been many debates about upgrading it and its support systems. However, as of 2013, there were insufficient results. Further, upon the designation of the East Coast and Chungbuk as official FEZs from February 4, 2013 by the 56th the Commission, there is a concern that many people are in the area designated as FEZ 8. This study investigates Korea's new FEZ system as part of Korea's primary new economic development policy in the 21st century. Therefore, this study examines views on the weaknesses of the past ten years of FEZs so that Korea can expand its FEZ system. Research design, data, and methodology -Many countries have considered the FEZ as an economic special zone. By reviewing previous research models, this study provides an update using recent data and materials, until 2013, from the Center of Free Economic Zones. In previous studies, the lack of support systems was attributed to proposals to ensure operational autonomy and differentiation of each FEZ; however, the main cause cannot be solved through regulatory issues, as difficulties caused by the operational system are responsible for the problems. We wish to analyze the FEZ, specifically the operational system; this is the main issue of this study. Results - After the first FEZs were established, it became necessary to have basic plans, as investment results in 2013 compared to the same period this year led to lower earnings in the first half of 2014. We propose an improvement of the operational system because in the free economic zones, the operational system is the root cause of the underlying problem. The results of this research are as follows. The weak management of the FEZ system is influenced by weak investment, delayed development, foreigners' living facilities, benefits of foreign investments, the control tower's policy making decision process, quickness of the process of satisfying legal requirements, and support For the independence of FEZs. Conclusion - Local governments do not have legal rights over FEZ deregulation and investment industries. This study suggests that the local government should have more independence from the central government. Moreover, independent management committees are more effective for ensuring public rights, better employee responsibilities, and better-qualified personnel. The FEZ committee struggles to effectively manage the locations of FEZs, foreign investments, and related facilities under the control of the Ministry of Trade, Industry and Energy. Thus, the FEZ committee should be under either the Prime Minister's office or the Presidential committee, to control and effectively coordinate between the local and central governments. If the problem clearly applies to the operational system in 2013, it is necessary to provide materials and methods so that the results of the first half of 2014 can be computed despite the data limits and lack of resources, and the data can be analyzed in a more diachronic thesis.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.2
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• pp.213-221
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• 2009

An aircraft collision accident is a disaster that causes great losses of inventories and lives. Though a collision avoidance warning function is provided automatically to pilots in the aircrafts by the enhancement of the aircraft capability, achieving fast decision-making to escape a collision situation is a complex and dangerous work for pilots. If an in-flight collision situation is controlled by the air traffic control system which monitors all airplanes in the air, it would be more efficient to prevent in-flight collisions because it can handle the emergency before the pilot's action. In this paper, we develop the collision avoidance warning function in the air traffic control system. Specifically, we design and implement the five stages of the collision avoidance function, and propose a visualization method which could effectively provide the operators with the trajectories and altitudes of the aircrafts in a collision situation. By developing an in-flight collision warning function in the air traffic control system that visualizes flight patterns through the state transition data of in-flight aircrafts on the flight path lines, it can effectively prevent in-flight collisions with traffic alerts. The developed function allows operators to effectively select and control the aircraft in a collision situation by providing the operators with the expected collision time, the relative distance, and the relative altitude while assessing the level of alert, and visualizing the alert information which includes the Attention-Warning-Alert phase via embodying the TCAS standard. With the developed function the air traffic control system could sense an in-flight collision situation before the pilot's decision-making moment.

• Aerospace Engineering and Technology
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• v.11 no.1
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• pp.158-168
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• 2012

This paper deals with TVC nozzle stroke verification test and corresponding analysis techniques related to kick motor TVC system of KSLV-I second stage. It is shown that the relationship between TVC stroke and potentiometer voltage is revealed via the open-loop stroke verification test, and other major operational parameters including nozzle alignment error, actuation error, neutral position, radius of nozzle rotation, location of nozzle rotation center, angle conversion coefficients, etc. are analyzed via the closed-loop stroke verification test. The TVC stroke verification test results for the first and second flight model of KSLV-I show that all TVC operational parameters of KSLV-I second stage were normally setup for the first and second flight tests.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.7
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• pp.97-104
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• 2011

This paper presents modeling and control for the emerging IGBT converter-based high-voltage direct-current system (IGBT-HVDC). This paper adds to the representation of the IGBT-HVDC system in the dq-synchronous reference frame and its decoupled control scheme. Additionally, since the IGBT-HVDC is able to actively support the grid due to its capacity to control independently active and reactive power production, a reactive power control scheme is presented in order to regulate/contribute to the voltage at a remote location by taking into account its operational state and limits. The ability of the control scheme is assessed and discussed by means of simulations using ahybrid power system, which consists of a permanent magnetic synchronous-generator (PMSG) based wind turbine, an IGBT-HVDC, and a local load.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.992-995
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• 1996

The major roles of Power SCADA System are continuous monitoring of electrical equipments state, real-time data processing and dispatching. Especially, SCADA system demands fast response time in heavy load condition, high reliability, fault tolerance, expansion capacity for the future. According to developing computer system technology, SCADA system is changing system configuration from centralized processing system to distributed processing system. This paper describes operational benefits, problems and improvement (which is studying in theory) in the application of Open System Architecture SCADA which has been installed since 1994, Seoul regional control center in KEPCO.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.67 no.4
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• pp.200-207
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• 2018

In recent, KEPCO (Korea Electric Power Corporation) faced difficulties of the DCC (distribution control center) due to the increase of field equipment and operational cost, and aging of operating staffs. In response to these changes in the DCC, KEPCO is trying to change the organization and system of the DCC. In this paper, we present a new attempt to change organization and structure of distribution control center, which was implemented by KEPCO recently. This paper is divided into three major parts. First, to examine the adequacy of the divided basis of current DCCs based on the quantity of installed electrical equipment, we analyzed the correlation between the operational history of the DCCs and the number of equipment. Through the analysis, we confirmed that there is little relationship between the number of equipment and actual workload. Second, we conducted visits and questionnaire surveys of all the DCCs to identify factors affecting the actual workload of distribution operators and then summarized the results. Third, based on this survey, a general formula for analyzing the workload of a DCC was derived, and each DCC's average annual total workload, day/night workload, and required number of personnel were calculated. Through this study, we proposed a more realistic management method of DCCs that can overcome the division criteria based on equipment quantity.