• International Journal of Control, Automation, and Systems
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• v.3 no.3
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• pp.493-501
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• 2005

A power plant simulation tool ('PowerSim') has been developed with 10 years experience from the development of a plant simulator for efficient modeling of a power plant. PowerSim is the first developed tool in Korea for plant simulation with various plant component models, instructor station function and the Graphic Model Builder (GMB). PowerSim is composed of a graphic editor using general purpose design software, a netlist converter, component models, the scheduler, Instructor Station and an executive. The graphic editor generates a netlist that shows the connection status of the various plant components from the Simdiagram, which is drawn by Icon Drag method supported by GUI environment of the PowerSim. Netlist Converter normalizes the connection status of the components. Scheduler makes scheduling for the execution of the device models according to the netlist. Therefore, the user makes Simdiagram based on the plant Pipe and Instrument Drawing (P&ID) and inputs the plant data for automatic simulating execution. This paper introduces Graphic Model Builder (GMB), instructor station, executive and the detailed introduction of thermal-hydraulic modeling. This paper will also introduce basic ideas on how the simulation Diagram, based on netlist generated from general purpose design software, is made and how the system is organized. The developed tool has been verified through the simulation of a real power plant.

• The Korean Journal of Health Service Management
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• v.6 no.4
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• pp.153-163
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• 2012

The purpose of this study is to measure IPA(Importance Performance Analysis) of the hospital choice factors between internal and external customers at rural general hospital. This study was used 5 types of choice factor such as physical, human, accessibility, connection, and external image. Also, this study was used IPA which can be applied to identify the strengths and weaknesses quality attributes from customers' viewpoint by simultaneously evaluating importance and performance. IPA was assessed using a sample of 98 patients and 96 internal employees who work at C general hospital in Chunkcheongbuk-do. Data were collected with self-administered questionnaires from February 13 to March 30 in 2012 and analyzed SPSS 18 by using frequency, paired t-test and scatter plot graph. The results of IPA show that "Keep up the good work" quadrant was human factor and "Low Priority" quadrant was physical and connection factors between internal and external customers. The finding of this study will be applied to improve human service quality in administrative department of hospital. Also, this study presents primary data for correct decision making to authorities of local hospitals that have concern about hospital strategy. The implications of this study are discussed and areas for future research are presented.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.4
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• pp.241-245
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• 2011

In this paper, when photovoltaic (PV) systems are connected to power distribution system, most effective capacity and connected-point of PV system are presented considering power distribution system reliability. The reliability model of PV system is presented considering the duration of sunshine. Also the model of time-varying load and reliability test system bus2 model are used. To simulate the effects of PV system, various cases are selected; (1) base case which is no connection of PV system to power distribution system when faults are occurred, (2) 3MW case which is 3[MW] connection of PV system (3) 4[MW] case, and (4) 20[MW] case which is 20[MW] connection of PV system to the bus of power distribution system. The capacity limit of connected PV system is settled to 14[MW] for all cases except case 4. The reliability for residential, general, industrial, and educational customer is evaluated.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.988-993
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• 2004

This paper considers corrosion problems in the bolt connection of weathering steel box girder bridge using the external electric type corrosion resistance method which resisted to local corrosion in coated steel surface with contacted air. The weathering steel was created a rust itself in the passive state. but a coated box girder type was easily dew form could be made galvanic cell that accelerated corrosion. so that it was ruled by protection coat with some paint. Therefore, it needed that can be applied the external electric type corrosion resistance method in coated surface. As a result of the test of polarization amount had measured that the weathering steel was higher currents than the general steel by about $5\~10\%$. Therefore. an external electric type corrosion resistance method can be used to protect local corrosion in the coated bolt connection of weathering steel box girders effectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.08a
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• pp.37-40
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• 2002

Ground connection began by experimenting lightning with the use of a kite and it means electric appliances, communication equipments, measuring instruments and so on connecting the Earth in order to flow away overcharged electricity. There are two kinds of earth connection: Power Ground and Signal Ground. Power Ground is for preventing an electric shock and in general there's no current in the connector. However in an accident, there's a quick flow of electricity out to the Earth. Signal Ground is not only for the safety of appliances but also for the safety of equipment operation. This paper is about connection for noise and interference reduce in order to prevent wrong operation and distortion of signal in the electrical appliances which can take place in cable TV.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.593-598
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• 2000

In this paper the critical speed analysis and design sensitivity investigation are carried out with an APU(auxiliary power unit) gas turbine having a spline shaft connection. The DDM(direct differential method) is directly applied to formulate the critical speed design sensitivity problem of a general nonsymmetric-matrix rotor-bearing system. The design sensitivity analysis have shown that the critical speed change rate to the support modeling of the spline shaft connection point is extremely negligible, and thereby its design uncertainty is lifted. It has also been confirmed that the critical speeds up to the 4th are not sensitive to the design stiffness coefficients of 4-main bearings or supports, including two air foil bearings. Further, the critical speed change rate to the shaft-element length have shown quantitatively that the spline shaft has some limited influence on the 4th critical speed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.12
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• pp.1992-2007
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• 1997

A new algorithm for planning a collision-free path is developed based on linear prametric curve. In this paper robot is assumed to a point, and two linear parametric curve is used to construct a path connecting start and goal point, in which single intermediate connection point between start and goal point is considered. The intermediate connection point is set in polar coordinate(${\theta}{\delta}$) , and the interference between path and obstacle is mapped into CPS(connection point space), which is defined a CWS GM(circular work space geometry mapping). GM of all obstacles in workspace creates overlapping images of obstacle in CPS(Connection Point Space). The GM for all obstacles produces overlapping images of obstacle in CPS. The empty area of CPS that is not occupied by obstacle images represents collision-free paths in Euclidian Space. A GM based on connection point in elliptic coordinate(${\theta}{\delta}$) is also developed in that the total length of path is depend only on the variable .delta.. Hence in EWS GM(elliptic work space geometry mapping), increasing .delta. and finding the value of .delta. for collision-free path, the shortest path can be searched without carring out whole GM. The GM of obstacles expersses all possible collision-free path as empty spaces in CPS. If there is no empty space available in CPS, it indicates that path planning is not possible with given number of connection points, i.e. path planning is failed, and it is necessary to increase the number of connection point. A general case collision-free path planning is possible by appling GM to configuration space obstacles. Simulation of GM of obstacles in Euclidian space is carried out to measure performance of algorithm and the resulting obstacle images are reported.

• Journal of The Korea Institute of Healthcare Architecture
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• v.29 no.2
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• pp.39-48
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• 2023

Purpose: In Korea, the increase rate of the number of mentally ill patients increases, and the hospitalization period for severely mentally ill patients to stay in acute wards is long and the re-hospitalization rate is high. In order to improve the dignity of patients with acute mental illness and to plan a therapeutic environment for this, this study attempted to present a basic framework of spacial planning for establishing guidelines for psychiatric acute ward in general hospitals. Methods: By analyzing the acute psychiatric ward guidelines of the UK, Australia, and the US., this study analyzed the areas and required rooms of psychiatric acute ward in general hospitals, as well as the net floor area of each room, and the connection between the rooms. Results: As a result of the study, the basic framework for the ward areas and the required rooms, the net floor areas of the rooms, and the connection between the rooms were presented for the establishment of guidelines for the psychiatric acute ward in general hospitals. Implication: The results of the study will be used as a basic framework of space planning for establishing of guidelines for the psychiatric acute ward in general hospitals and will contribute to the establishment of detailed guidelines based on the space configuration through surveys and analysis of space use status, operation status, and expert interviews in Korea.

• Journal of Mechanical Science and Technology
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• v.17 no.1
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• pp.57-63
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• 2003

An eigenvalue design sensitivity formulation of a general nonsymmetric-matrix rotor-bearing system is devised. using the DDM (direct differential method). Then, investigations on the design sensitivities of critical speeds are carried out for an APU turbogenerator with a spline shaft connection. Results show that the dependence of the rate of change of the critical speed on the stiffness changes of bearing models of spline shaft connection points is negligible, and thereby their modeling uncertainty does not present any problem. And the passing critical speeds up to the 4th critical speed are not sensitive to the design stiffness coefficients of four main bearings. Further, the dependence of the rate of change of the critical speed on the shaft-element length changes shows quantitatively that the spline shaft has some limited influence on the 4th critical speed but no influence on the 1st to 3rd critical speeds. With no adverse effect from the spline shaft, the APU system achieves a critical speed separation margin of more than 40% at a rated speed of 60,000 rpm.

• Journal of Chest Surgery
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• v.22 no.1
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• pp.25-31
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• 1989

Forty-five patients, aged 16 months to 15.5 years mean 69 months, with a wide variety of cardiac malformations underwent the modified Fontan operation between Sep. 1986 to Aug. 1988. Nineteen patients had previously undergone palliative operations mainly modified B-T shunt. Twenty patients had a mean pulmonary artery pressure greater than 15 mmHg, with nine operative deaths. Thirteen patients had anomalies of systemic venous connection and seven patients had anomalies of pulmonary venous connection. There were eighteen patients under the age 4 years and fifteen of them survived [83.3%]. Eighteen patients had a pulmonary vascular resistance [PVR] more than 2.5U/m, and nine died [50%] whereas two of twenty-three with a PVR less than 2.5U/m died[8.6%]. PVR and anomalies of pulmonary venous connection had a significant influence on survival, but age and anomalies of systemic venous connection did not. Amount of pleural effusion drained postoperatively and PVR had positive linear correlation. Pulmonary artery pressure was not an independent predictor of outcome and pulmonary artery pressure alone should not contraindicate a Fontan procedure if PVR is low. In general, the Fontan operation should be done at a younger age less than 4 year to avoid ventricular dysfunction due to long-standing exposure to hypoxia.