• Journal of the Institute of Convergence Signal Processing
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• v.14 no.3
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• pp.205-211
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• 2013

Recently, the needs of system performances such as working speed and processing accuracy in machine tools have been increased. Especially, the working speed increment generates harmful heat at both moving part of the machine tools and handicrafts. The heat is a main drawback to progress accuracy of the processing. Hence, a oil cooler to control temperature is inevitable for the machine tools. In general, two representative control schemes, hot-gas bypass and variable speed control of a compressor, have been adopted in the oil cooler system. This paper deals with design and implementation method of fuzzy controller for obtaining precise temperature characteristic of HB oil cooler system in machine tools. The opening angle of an electronic expansion valve are controlled to keep reference value and room temperature of temperature at oil outlet. Especially, the fuzzy controller is added to suppress temperature fluctuation under abrupt disturbances. Through some experiments, the suggested method can control the target temperature within steady state error of ${\pm}0.22^{\circ}C$.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.4
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• pp.303-308
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• 2010

Excessive oral and maxillofacial bleeding causes upper airway obstruction, bronchotracheal and gastric aspiration and hypovolemic shock. Therefore, the rapid and correct bleeding control is very important for saving lives in the emergency room. Despite the conventional bleeding control methods of wiring (jaw fracture, wound suture and direct pressure), continuous bleeding can occur due to the presence of various bleeding disorders. There are five main causes for excessive bleeding disorders in the clinical phase; (1) vascular wall alteration (infection, scurvy etc.), (2) disorders of platelet function (3) thrombocytopenic purpura (4) inherited disorders of coagulation, and (5) acquired disorders of coagulation (liver disease, anticoagulant drug etc.). In particular, infections can alter the structure and function of the vascular wall to a point at which the patient may have a clinical bleeding problem due to vessel engorgement and erosion. Wound infection is a frequent cause of postoperative active bleeding. To prevent postoperative bleeding, early infection control using a wound suture with proper drainage establishment is very important, particularly in the active bleeding sites in a contaminated emergency room. This is a case report of a rational bleeding control method by rapid wiring, wound suture with drainage of a rubber strip & iodoform gauze and wet gauze packing, in a 26-year-old male cerebral palsy patient with active oral and maxillofacial bleeding injuries caused by a traffic accident.

• Nuclear Engineering and Technology
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• v.44 no.8
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• pp.929-938
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• 2012

The Computerized Procedure System (CPS) is one of the primary operating support systems in the digital Main Control Room. The CPS displays procedure on the computer screen in the form of a flow chart, and displays plant operating information along with procedure instructions. It also supports operator decision making by providing a system decision. A procedure flow should be correct and reliable, as an error would lead to operator misjudgment and inadequate control. In this paper we present a modeling for the CPS that enables formal verification based on Petri nets. The proposed State Token Petri Nets (STPN) also support modeling of a procedure flow that has various interruptions by the operator, according to the plant condition. STPN modeling is compared with Coloured Petri net when they are applied to Emergency Operating Computerized Procedure. A converting program for Computerized Procedure (CP) to STPN has been also developed. The formal verification and validation methods of CP with STPN increase the safety of a nuclear power plant and provide digital quality assurance means that are needed when the role and function of the CPS is increasing.

• Nuclear Engineering and Technology
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• v.44 no.6
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• pp.653-662
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• 2012

We evaluate the technical and organizational aspects of the severe accident management guideline (SAMG), focusing on the decision-making process in the technical support center (TSC). From the technical aspects, we conclude that the present SAMG is a good tool that can assist the TSC in efficiently managing probable severe accidents. However, we suggest that the clear separation of the emergency operating procedure (EOP) and SAMG, which shifts plant control from the main control room (MCR) to the TSC, might not be an effective framework from an organizational perspective. Studies on organizational behavior demonstrate that a group decision made under a risky situation might be polarized in either a risky or cautious way. We recognize that we cannot be free from the polarization effect since the current SAMG recommends that the TSC evaluate the advantages and disadvantages of strategies to be implemented and choose the best one based on a group decision process. Illustrative examples of accident management under risky conditions are recapitulated from previous studies of the authors and we propose that the SAMG should be more proceduralized to remove this polarization from the decision-making process.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2723-2725
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• 2001

Nuclear power generations have been developed gradually since 1950. Nowadays, 440 nuclear power generations are taking charge of 16% of electric power production in the world. The most important factor to operate the nuclear power generations is safety. It is not easy way to control nuclear power generations with safety because nuclear power generations are very complicated systems. In the main control room of the nuclear power generations, about 4000 numbers of alarms and monitoring devices are equipped to handle the signals corresponding to operating equipments. Thus, operators have to deal with massive information and to grasp the situation immediately. If they could not achieve these task, then they should make big problem in the power generations Owing to too many variables, operators could be also in the uncontrolled situation. So in this paper, automatic systems to diagnose the fault are constructed using 2 steps neural networks. This diagnosis method is based on the pattern of the principal variables which could represent the type and severity of faults.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.3
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• pp.292-300
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• 2014

The Laplace Transform solution is used as a mathematical model to analyse the thermal performance of the building constructed using different wall materials. The solution obtained from Laplace Transform is an analytical solution of an one dimensional, linear, partial differential equation for wall temperature profiles and room air temperatures. The main purpose of the study is showing the detail of obtaining solution process of the Laplace Transform. This study is conducted using weather data from two different locations in Korea: Seoul, Busan for both winter and summer conditions. A comparison is made for the cases of an on-off controller and a proportional controller. The weather data are processed to yield hourly average monthly values. Energy consumption load is well calculated from the solution. The result shows that there is an effect of mass on the thermal performance of heavily constructed house in mild weather conditions such as Busan. Building using proportional control experience a higher comfort level in a comparison of building using on-off control.

• Progress in Superconductivity and Cryogenics
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• v.11 no.3
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• pp.26-30
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• 2009

Korea Superconducting Tokamak Advanced Research(KSTAR) device is composed of 30 superconducting magnets, magnet structure, vacuum vessel, cryostat, current feeder system, and etc. KSTAR device is operated in the cryogenic temperature and high magnetic field. We install about 800 sensors - temperature sensors, stain gages, displacement gages, hall sensors - to monitor the thermal, mechanical, electrical status of KSTAR during operation. As a tremendous numbers of sensors should be installed for monitoring the KSTAR device, the method of effective installation was developed. The sensor test was successfully carried out to check its reliability and its reproduction in the cryogenic temperature. The sensor signal is processed by PXI-based DAQ system and communicated with central control system via machine network and is shown by Operator Interface(OPI) display in the main control room. In order to safely operate the device, any violations of mechanical & superconductive characteristic of the device components were informed to its operation system & operator. If the monitored values exceed the pre-set values, the protective action should be taken against the possible damage. In this paper, the system composition, operation criteria, operation result were presented.

• Journal of Internet Computing and Services
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• v.24 no.4
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• pp.57-64
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• 2023

The ROK military faces a significant challenge in its vigilance mission due to demographic problems, particularly the current aging population and population cliff. This study demonstrates the crucial role of the 4th industrial revolution and its core artificial intelligence algorithm in maximizing work efficiency within the Command&Control room by mechanizing simple tasks. To achieve a fully developed military surveillance system, we have chosen multi-object tracking (MOT) technology as an essential artificial intelligence component, aligning with our goal of an intelligent and automated surveillance system. Additionally, we have prioritized data visualization and user interface to ensure system accessibility and efficiency. These complementary elements come together to form a cohesive software application. The CCTV video data for this study was collected from the CCTV cameras installed at the 1st and 2nd main gates of the 00 unit, with the cooperation by Command&Control room. Experimental results indicate that an intelligent and automated surveillance system enables the delivery of more information to the operators in the room. However, it is important to acknowledge the limitations of the developed software system in this study. By highlighting these limitations, we can present the future direction for the development of military surveillance systems.

• Nuclear Engineering and Technology
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• v.52 no.2
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• pp.397-416
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• 2020

Investigations of the commercial aircraft impact effect on nuclear island infrastructures have been drawing extensive attention, and this paper aims to perform the safety assessment of Generation III nuclear power plant (NPP) buildings subjected to typical commercial aircrafts crash. At present Part II, based on the verified finite element (FE) models of aircrafts Airbus A320 and A380, as well as the NPP containment and auxiliary buildings in Part I of this paper, the whole collision process is reproduced numerically by adopting the coupled missile-target interaction approach with the finite element code LS-DYNA. The impact induced damage of NPP plant under four impact locations of containment (cylinder, air intake, conical roof and PCS water tank) and two impact locations of auxiliary buildings (exterior wall and roof of spent fuel pool room) are evaluated. Furthermore, by considering the inner structures in the containment and raft foundation of NPP, the structural vibration analyses are conducted under two impact locations (middle height of cylinder, main control room in the auxiliary buildings). It indicates that, within the discussed scenarios, NPP structures can withstand the impact of both two aircrafts, while the functionality of internal equipment on higher floors will be affected to some extent under impact induced vibrations, and A380 aircraft will cause more serious structural damage and vibrations than A320 aircraft. The present work can provide helpful references to assess the safety of the structures and inner equipment of NPP plant under commercial aircraft impact.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.10 no.6
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• pp.253-260
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• 2015

In this study, using the FDS as the fire simulation and evacuation simulations of the Pathfinder, set the main control room of the building to the fire point fire safety assessment studies were carried out. At first the quantitative result such as distribution of visibility as time passing, distribution of temperature, distribution of CO density produced results using fire-simulation and evacuation-simulation was carried out based on the result that produced the final safety evaluation result as being calculated of evacuation time. As the risk increased with the distribution of visibility at the result of fire-simulation, evacuation-simulation was carried out using the result. Finally the result was made 127.9 sec that everyone could evacuate. The numerical results are analyzed in case of the places in the building required safe egress time for safety a as the analysis to be no more than available safe egress time was analyzed to be secured. The results of this safety evaluation represent that more smooth evacuation safety performance can be secured by linking the event of fire firefighting equipment as a result of simulating the worst conditions.