• Journal of the Korean Institute of Gas
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• v.22 no.2
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• pp.1-20
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• 2018

Despite many measures, still from time to time catastrophic events occur, even after reviewing potential scenarios with HAZID tools. Therefore, it is evident that in order to prevent such events, answering the question: "What can go wrong?" requires more enhanced HAZID tools. Recently, new system based approaches have been proposed, such as STPA (system-theoretic process analysis) and Blended Hazid, but for the time being for several reasons their availability for general use is very limited. However, by making use of available advanced software and technology, traditional HAZID tools can still be improved in degree of completeness of identifying possible hazards and in work time efficiency. The new HAZID methodology proposed here, the Data-based semi-Automatic HAZard IDentification (DAHAZID), seeks to identify possible scenarios with a semi-automated system approach. Based on the two traditional HAZID tools, Hazard Operability (HAZOP) Study and Failure Modes, Effects, and Criticality Analysis (FMECA), the new method will minimize the limitations of each method. This will occur by means of a thorough systematic preparation before the tools are applied. Rather than depending on reading drawings to obtain connectivity information of process system equipment elements, this research is generating and presenting in prepopulated work sheets linked components together with all required information and space to note HAZID results. Next, this method can be integrated with proper guidelines regarding process safer design and hazard analysis. To examine its usefulness, the method will be applied to a case study.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.458-461
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• 2008

The primary objective of this study is to provide simple analytical tools to estimate dynamic characteristics of steel framed floor system in hospital building for vibration serviceability due to human activities, bogie, medical equipment. and so on. In order to evaluate the dynamic characteristics and vibration levels according to steel framed floor system, we had executed impact test and measurement on steel structure floor system in various hospital buildings. But perhaps most importantly, how to make the most of deduced design factor for design of hospital building. therefore we presented the access method such as the three-dimensional F.E. numerical analysis on the basis of the design drawing, and the properties of all floors for estimation of vibration level in hospital building.

• Journal of the Korea Computer Industry Society
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• v.10 no.3
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• pp.99-104
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• 2009

In this paper, fluorescent lamp on/off control and luminous intensity used an power line communication and remotely will be able to control system design. Embodied the respectively illumination equipment and tools by the network using PLC. In order to remote control and on/off of illumination equipment, luminous intensity composed a server. Will convert a previous analog system with digital system and the possibility witch will reduce an error ratio was. Consequently will be able to simplify a circuit.

• Journal of Welding and Joining
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• v.34 no.4
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• pp.9-16
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• 2016

Metal parts are produced by conventional methods such as casting, forging and cutting, extrusion, etc. However, nowadays, with additive manufacturing (AM), it is possible to directly commercialize by means of stacking of equipment to the 3D drawing and use of high precision tools such as laser source. Thus, drawing of materials is an important aspect in delivering good products. AM deals with production of lighter aircraft parts and few more three-dimensional molds, it wish to manufacture special medical parts and want to steadily expand the new market area. The cost of related equipment and materials are still expensive and difficult to obtain on a mass production. However, the ability to make changes and lead the innovation in the paradigm of traditional manufacturing process is still effective. In this paper, we introduce metal AM and the principles of the related devices, metal powder production process, and their application.

• Journal of Korea Multimedia Society
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• v.25 no.2
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• pp.197-205
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• 2022

The Cyber Physical System(CPS) is an important concept in achieving SMSs(Smart Manufacturing Systems). Generally, CPS consists of physical and virtual elements. The former involves manufacturing devices in the field space, whereas the latter includes the technologies such as network, data collection and analysis, security, and monitoring and control technologies in the cyber space. Currently, all these elements are being integrated for achieving SMSs in which we can control and analyze various kinds of producing and diagnostic issues in the cyber space without the need for human intervention. In this study, we focus on implementing a production equipment monitoring system related to building a SMS. First, we describe the development of a fog-based gateway system that links physical manufacturing devices with virtual elements. This system also interacts with the cloud server in a multimedia network environment. Second, we explain the proposed network infrastructure to implement a monitoring system operating on a cloud server. Then, we discuss our monitoring applications, and explain the experience of how to apply the ML(Machine Learning) method for predictive diagnostics.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.6
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• pp.476-484
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• 2007

Recently, in accordance with the buildings are becoming to large-sizes, high-stories, the large scaled facilities and equipments in machine room are quite demanding, and the generated noise volume according to this situation is on increasing. Since such noise is becoming to the object of a serious civil appeal, it is the real situation that a reduction countermeasure against the machine room equipment noise is keenly necessitated. On such viewpoint, this study has recorded, measured the noises which were generated from each individual as same as the whole equipped machines and tools, on the object of the dormitory machine rooms of the 3 colleges that haying mutually different peculiarities, then after grasp-ing their characters and acoustic powers, this research has verified its prediction possibility and the authenticity by comparison the estimated numerical value with the actually measured numerical value through the acoustic simulation. After grasping the prediction possibility in such way, by utilization of the sound absorption material in the machinery room, from the stage of design, the soundproof measures for the noise reduction at machine room could be regulated effectively, and it is also considered that such data would be utilized as the fundamental material for an establishment of the measure for sound insulation.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.30-35
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• 2008

This paper describes a fault detection and diagnosis (FDD) system developed for the heat source apparatus in building air-conditioning system. As HVAC&R systems in building become complex and instrumented with highly automated controllers, the processes and systems get more difficult for the operator to understand and detect the mal-functions. Poorly maintained, degraded, and improperly controlled equipment wastes an estimated 15% to 30% of energy used in commercial building. When operating a complex facility, FDD system is beneficial in equipment management to provide the operator with tools which can help in decision making for recovery from a failure of the system. Automated FDD for HVAC&R system has the potential to reduce energy and maintenance costs and improves comfort and reliability. Over the last decade there has been considerable research for developing FDD system for HVAC&R equipment. However, they are being made too much of a theoretical study, so only a small of FDD methods are deployed in the field. This study deduced an actual defect source for the heat source apparatus and suggested a low price FDD method which is ready to be deployed in the field.

• Journal of Power Electronics
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• v.15 no.4
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• pp.994-1005
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• 2015

This paper presents a novel power control strategy for PWM current-source rectifiers (CSRs) in the stationary frame based on the instantaneous power theory. In the proposed control strategy, a virtual resistance based on the capacitor voltage feedback is used to realize the active damping. In addition, the proportional resonant (PR) controller under the two-phase stationary coordinate is designed to track the ac reference current and to avoid the strong coupling brought about by the coordinate transformation. The limitations on improving steady-state performance of the PR controller is investigated and mitigated using a cascaded lead-lag compensator. In the z-domain, a straightforward procedure is developed to analyze and design the control-loop with the help of MATLAB/SISO software tools. In addition, robustness against parameter variations is analyzed. Finally, simulation and experimental results verify the proposed control scheme and design method.

• Journal of The Korea Institute of Healthcare Architecture
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• v.30 no.2
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• pp.23-34
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• 2024

Purpose: The Hybrid care environment, combining interventional procedures and surgeries in one space, is crucial for managing complex diseases, responding to emergencies, and reducing recovery times and pain. This study provides foundational data for creating architectural guidelines for a Hybrid Operating Unit in a general hospital's surgical department, focusing on cardiovascular care. Methods: The study analyzed the spatial and configuration types of the Vascular Angiography Unit and the Cardiac Operating Unit, which are the basic components of the Hybrid Operating Unit, through a literature review. Based on the initial research findings, interviews with experts were conducted. Results: In the Hybrid Operating Process, the study proposed spatial configuration alternatives that consider the positioning of medical staff and the types and arrangement changes of equipment, including Angiography, Heart-lung machines, and other surgical tools and instruments. Implications: The integration of the two units leads to increased diversity and demand for medical staff, equipment, and supplies during surgical and interventional procedures. Therefore, strategic spatial configurations and equipment placement are necessary to effectively respond to these needs.

• Journal of the Korea Furniture Society
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• v.20 no.4
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• pp.253-261
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• 2009

school. This study was carried out by literature review. Values of woodworking in extrinsic viewpoint were justified as well-balanced development between left brain and right brain, effective improvement of creative problem solving skill, formation of affirmative attitude toward woodworking, and obtaining method to use tools and equipment effectively. Values of woodworking in intrinsic viewpoint were justified as students' instinct liking of woodworking, psychological stability, and implanting self-confidence in students. In addition to these, woodworking has more educational values. Such values should be justified in the following studies.