• 수산해양교육연구
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• 제27권5호
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• pp.1221-1228
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• 2015

The purpose of this study was to describe and understand experiences of surgical ward practice in nursing students. The interview data were collected from 9 nursing students and analyzed by using descriptive phenomenology of Colazzi. The procedural steps was that described the phenomenon of interest, collected participants' descriptions of the phenomenon, extracted the meaning of significant statement, organized the meaning into them clusters, wrote exhaustive descriptions and then incorporated data into categories. The essential meanings of surgical ward practice experiences of nursing students were as following; 'Permission of direct nursing practice', 'Professionality of nursing domain', 'Serving as a stepping stone of patients' nursing', and 'Sense of achievement to participating nursing'. The results of this study would provide for basic data of surgical ward practice program and have important implication for understanding field practice in nursing. So would contribute to develop nursing practice curriculum.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.294-298
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• 2001

Satellite propulsion system is employed for orbit transfer, orbit correction, and attitude control. The monopropellant feeding system in the low-earth-orbit satellite blowdowns fuel to the thrust chamber. The thrust produced by the thruster depends on fuel amount flowed into the combustion chamber. If the thruster valve be given on-off signal from on-board commander in the satellite, valve will be opened or closed. When the thrusters fire fuel flows through opened thruster valve. Instantaneous stoppage of flow in according to valve actuation produces transient pressure due to pressure wave. This paper describes transient pressure predictions of the KOMPSAT2 propulsion system resulting from latching valve and thrust control valve operations. The time-dependent set of the fluid mass and momentum equations are calculated by Method of Characteristics (MOC).

• 대한기계학회논문집B
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• 제28권6호
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• pp.665-671
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• 2004

A mathematical model is presented to predict the frost properties and heat and mass transfer within the frost layer formed on a cold plate. The model consists of the laminar flow equations for air-side and the empirical correlation of local frost density. The correlation of local frost density used in this study is obtained from various experimental conditions by considering frosting parameters. The numerical results are compared with experimental data to validate the model, and agree well with experimental data within a maximum error of 9%.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2000년도 제14회 학술강연논문집
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• pp.6-6
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• 2000

On-orbit thermal behavior of KOMPSAT (Korea Multi-purpose Satellite) propulsion system employing hydrazine (N$_2$H$_4$) liquid monopropellant is addressed. Thermal control performance to prevent propellant freezing in spacecraft-operational orbit was verified by flight telemetry data obtained during LEOP (Launch and Early Operation Phase). Results are depicted in terms of temperature history during several orbits selected and are compared with acceptable temperature ranges of system components. Cyclic behavior of temperature is reduced into duty cycles of the avionics heaters and subsequently converted into the electrical power required to keep away from propellant freezing. Temperature of each component which was achieved under on-ground thermal-balanced condition of spacecraft, is presented for comparison with the flight data, additionally.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.199-202
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• 2007

In storm sewer networks a lot of manholes are installed to maintain and connect a sewer of urban area. There are some shapes of manhole such as circular type, square type, and so on. Square shape manholes are installed to connect the large diameter drainage pipes in general and have lager head losses than circular one. Consequently, it is important to analyze the head losses in square manhole because the head losses in square manhole are much bigger than the friction losses in pipes. Hydraulic experimental apparatus which can be changed the inside shape in square manhole was installed for this study. The experimental discharge was $16{\ell}/sec$. The head loss coefficients in the manhole were calculated by the experimental results. The range of head loss coefficients in the general square manhole were from 0.33 to 0.48 and the range of head loss coefficients in the square manhole changed inside shape were from 0.23 to 0.28.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.595-598
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• 2007

Urban storm water collection and conveyance systems are critical components of the urban infrastructures. During a storm event, street grate inlets are usually loaded with debris by the first-flush runoff volume. Grate inlets are subject to clogging effects. Effective interception area of grate inlets was decreased by clogging. It also decreased the interception capacity of grate inlets and increased the inundation area in street. Therefore, it is necessary to analyze the clogging characteristics and interception capacity change by clogging for appropriate design and management of grate inlets. In this study, field survey was executed to investigate debris and clogging pattern of grate inlet in 9 areas. The clogging factor with consideration of urban area characteristics was estimated with the field survey results.

• E2M - 전기 전자와 첨단 소재
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• 제10권5호
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• pp.419-424
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• 1997

It is well known that the metallo-phthalocyanines (MPcs) are sensitive to toxic gaseous molecules such as NO$_2$ as well as are chemically and thermally stable. Therefore, lots of MPcs have been studied as the potential chemical sensor for NO$_2$gas using quartz crystal microbalance(QCM) or electrical conductivity. In this study, thin films of octa(2-ethylhexyloxy)copper-phthalocyanine were prepared by Langmuir-Blodgett method and characterized by using UV-VIS absorption spectroscopy and ellipsometry. Optimal transfer condition of LB films was investigated and preliminary results of current-voltage(I-V) characteristics of these films exposed to NO$_2$gas as a function of film thickness, temperature and concentration were discussed.

• 한국항만경제학회지
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• 제21권4호
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• pp.1-31
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• 2005

Major companies in USA, Europe and Japan as well as even China and Russia put more overseas investment in Asian regions than before, while northeast Asian regional trade gets more attractive and important under the influence of China's super-speed economic growth. Possibly, it is expected that such ever-increasing gravity of regional trade will help spotlight the importance of local trade route considerably. In particular, northeast Asian region's economic briskness and step-up in international economic partnerships will expectedly contribute to much boosting up the quantity of goods transported via local coasting route. Thus, it is advisable that both Busan New port specialize in dealing with freights via East Sea rim, while Gwangyang port specialize in dealing with freights via Yellow Sea rim. Furthermore, it is required that both ports share some of their own roles as hub port and hub & spoke port respectively, so that both of them can be devoted to stepping up into northeast Asian hub ports.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 추계학술대회 논문집 학회본부
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• pp.382-385
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• 1991

In order to stabilize linear time-invariant systems with the unknown system matrix, a piecewise constant linear state feedback control law including switching logic is developed. A number of feedback gain matrices are first precomputed by solving the Algebraic Riccati Equation with prescribed degree of stability, and then are switched over in a direction to increase degree of stability. Switching stops when a Lyapunov function shows the decreasing property, and hence switching times are finite.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.49-51
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• 2004

This paper presents a realization of fault detection algorithm and Fieldbus based communication for condition monitoring of check valve. We first acquired the AE(Acoustic Emission) sensor data at the KAERI check valve test loop, extract fault features through the learned Neural network, and send the processed data to a remote site. The overall system has been implemented and experimental results are given to show its effectiveness.