• Aerospace Engineering and Technology
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• v.7 no.2
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• pp.46-52
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• 2008

The instrumentation was studied in order to measure aerodynamic performance and efficiency of a compressor as a component of a 5MW-class gas turbine for power generation. In case of an axial compressor, the distributions of static pressure on a casing can be obtained by averaging at each stage and those of total pressure and temperature in the flow field of the compressor can be measured with a Kiel temperature probe. In case of a centrifugal compressor, the static pressures at the hub and the tip, respectively, of an impeller exit are considerably different, so the pressures need to be measured at both positions and thereafter averaged. The distributions of static pressures in a diffuser and a deswirler are measured at ten positions along five streamlines in one pitch. In addition the flow field can be measured in detail by 5-hole Pitot tube in order to analyze the flow characteristics of the core flow region and wake region and the rotor-stator interaction of the compressor.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.8
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• pp.1091-1096
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• 2012

The aerodynamic characteristics of circular cylinder in a channel are studied to make clear the flow feature by solving the Navier-Stokes equation based on the finite volume method with unstructured grids. Reviews are made on with the vorticity, velocity, dynamic pressure, residual and drag, where the Reynolds numbers are 50 and 100. The flows for $Re{\succeq}50$ shows the vortex shedding in the wake, and the result is the same as the case of moving cylinder. The ground effect of flat bottom results in the growth of vortex, being generated in the upper side of the cylinder and elongated in the rear. As the cylinder approaches to wall, for example 0.6, the cylinder plays as a role of blockage to obstruct the flow between the cylinder and wall. The drag coefficients are compared with others' results to confirm the validity of the present numerical simulation.

• Journal of Korean Public Health Nursing
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• v.7 no.1
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• pp.1-16
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• 1993

The objective of this study is to review the role and function of the village health worker in the wake of the recent social changes in Korea. The stud}' also aimed at' elucidating' the characteristics of the village health worker organizations developed through community participation in this country. The study methods employed were: a review of literature and other existing information related to VHW's activities ; the use of Questionnaire and interview with VHW's on their activities in one selected county in 1992. The major findings obtained are as follows: 1. So far the community health care activities have been carried out by medical colleges, foreign aid agencies and religious organizations with a view to improving health care for the population in rural area. 2. The VHWs employed by the local community health services received remuneratiorin cash or in kind. However, presently no remuneration is paid to VHWs employed by the government village health projects. The training for VHWs is organized by County Health Center once a year for 1-2days regardless of pre-employment or refresher. 3. The needs of care for maternal and child health and family planning has been decline due to the decrease of the target population, but on the other hand, the needs of care by VHW for prevention of infectious diseases, health of the aging, management of geriatric diseases, prevention of poisoning of pesticides and environmental sanitation has beer increased. 4. It was felt strongly that the training for VHWs should be strengthened by means of developing a problem-solving oriented educational program in order to improve practical skills of VHWs.

• Journal of Korean Society of Rural Planning
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• v.22 no.3
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• pp.71-80
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• 2016

Korea is becoming a model country for the developing countries' agricultural and rural development. Drawing implications for Vietnam from Korea's experiences can help make development strategies and policies for other developing countries including North Korea as well as for Vietnam itself. Vietnam is facing an inefficiency in agricultural production and the gap between urban and rural growth has been widening. Farm sizes per household are small and farmlands are scattered. Diversification in rural industry is very restricted. To attack these problems, investment is urgently needed for rural infrastructure building as well as agricultural structure adjustment. In the process of rural development, there have been also encountered such problems as financial procurement, community's spontaneous participation, manpower development for adjusting to industrial structural change. Korea's experiences may be helpful for establishing rural development strategies and policies in Vietnam. Benchmark scopes can go beyond Saemaul Undong in 1970s. Korea's pre- and post-Saemaul Undong era as well as the Saemaul Undong era can be referred. In the wake of globalization, Vietnam has not only experienced compressed rapid economic growth but also encountered policy tasks to eradicate poverty, to realize self-reliance and income increase, and to lessen urban-rural development gap, at the same time. Korea's experiences show that priority needs to be put on the establishment of national and rural development strategies based on Vietnam-specific conditions, utilization of village's resources including community tradition and social capital, fund raising for rural development, farmland development and mobilization, production and living infrastructure building, technology transfer for farmers and vocational training for new job seekers.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.10
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• pp.823-832
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• 2018

In general, the fidelity of the aircraft dynamic model is verified by comparison with the flight test results of the target aircraft. Therefore, the reference flight data for performance comparisons must be extracted. This process requires a lot of time and manpower to extract useful data from the vast quantity of flight test data containing various noise for comparing fidelity. In particular, processing of flight data is complex because rotorcraft have high non-linearity characteristics such as coupling and wake interference effect and perform various maneuvers such as hover and backward flight. This study defines flight data processing criteria for rotorcraft and provides procedures and methods for automated processing of static and dynamic flight data using data mining techniques. Finally, the methods presented are validated using flight data.

• Journal of Korean Society of Steel Construction
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• v.9 no.2 s.31
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• pp.269-275
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• 1997

Wind tunnel test results and their interpretations, which were performed to study the aerodynamic stability of tower of self-anchored suspension bridge, are presented in this paper. Tower and full models were tested under smooth and turbulent flow conditions. In the case of the tower with inclined two columns, the vibration due to wakes were occurred at wide velocity zone because the wakes with various frequencies were generated by inclined upstream column. It has to be emphasized that the vibration characteristics of the tower in the self-anchored suspension bridge may be very sensitive to the longitudinal boundary conditions of the girder at the supports. Because of the two natural frequency of the tower, out-of-plane bending and torsional, were not well separated, coupled motions were observed in a wide range of wind velocity. The effectiveness of corner cut, countermeasure to reduce the tower vibrations, was also studied. It has been found that 1:10, comer cut size to column width, may be the most effective ratio for reducing the vibrations.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.1
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• pp.9-25
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• 1994

In the present study, the Reynolds-averaged Navier-Stokes equations, together with the equations of the $k-{\varepsilon}$ model of turbulence, were solved numerically in a general body-fitted coordinate system for three-dimensional turbulent flows around the six basic shapes of the magnetically levitated train(MAGLEV). The numerical computations were conducted on the MAGLEV model configurations to provide information on shapes of this type very near the elevated track at a constant Reynolds number of $1.48{\times}10^{6}$ based on the body length. The coordinate system was generated by numerically solving a set of Poisson equations. The convective transport equations were discretized using the finite-analytic scheme which employed analytic solutions of the locally-linearized equations. A time marching algorithm was employed to enable future extensions to be made to handle unsteady and fully-elliptic problems. The pressure-velocity coupling was treated with the SIMPLER-algorithm. Of particular interests were wall effect by the elevated track on the aerodynamic forces and flow characteristics of the six models calculated. The results indicated that the half-circle configuration with extended sides and with smooth curvature of sides was desirable because of the low aerodynamic forces and pitching moment. And it was found that the separation bubble was occured at wake region in near the elevated track.

• Wind and Structures
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• v.22 no.4
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• pp.477-501
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• 2016

Though hilly topography influences both wind speeds and directions aloft, only the influence on wind speeds, i.e. the speed-up effect, has been thoroughly investigated. Due to the importance of a model showing the spatial variations of wind directions above hilly terrains, it is worthwhile to systematically assess the applicability and limitations of the model describing the influence of hilly topographies on wind directions. Based on wind-tunnel test results, a model, which describes the horizontal and vertical variations of the wind directions separately, has been proposed in a companion paper. CFD (Computational Fluid Dynamics) techniques were employed in the present paper to evaluate the applicability of the proposed model. From the investigation, it has been found that the model is acceptable for describing the vertical variation of wind directions by a shallow hill whose primary-to-secondary axis ratio (aspect ratio) is larger than 1. When the overall hill slope exceeds $20^{\circ}$, the proposed model should be used with caution. When the aspect ratio is less than 1, the proposed model is less accurate in predicting the spatial variation of wind directions in the wake zone in a separated flow. In addition, it has been found that local slope of a hill has significant impact on the applicability of the proposed model. Specifically, the proposed model is only applicable when local slope of a hill varies gradually from 0 (at the hill foot) to the maximum value (at the mid-slope point) and then to 0 (at the hill top).

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.1
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• pp.29-37
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• 2011

PIV measurements of the velocity field, pressure field, vorticity, and turbulent intensity in the rear of curved section of an oil fence with current speed showed that the flow directions in the rear of flow boundary area were similar to those in the front of it. As the current speed increased, the patterns of pressure distribution were changed, and the turbulent flow became more irregular. CFD simulations under the same conditions as the PIV tests showed that the flow patterns of the wake were similar to those by PIV tests in speed of 0.3 m/s and less, but were distinctively deviated from those in 0.4 m/s due to the flexibility of the oil fence, which was not properly taken care of in CFD modeling.

• Korean Journal of Psychosomatic Medicine
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• v.7 no.2
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• pp.241-246
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• 1999

Delirium is a syndrome characterized by impairement of consciousness, disorientation, disturbance of sleep-wake cycle, memory impairement, disturbance of perception. It is induced by many causes, which are CNS diseases(head trauma, vascular disease, brain tumor, etc), medical diseases(metabolic disorder, endocrine disturbance, cardiovascular disease) and drugs(anticholinergics, anticonvulsant, antipsychotics, cimetidine etc). Transdermal scopolamine which is usually used to prevent motion sickness has anticholinergic property, and so it can induce delirium. The authors report two cases of delirium induced by transdermal scopolamine. The cases shared common characteristics which were as follows : 1. All of two patients were elderly women. 2. Delirium symptom was abruptly occurred during trip after attaching scopolamine patches. 3. Delirium symptom was rapidly improved within 2-3 days. It is important to educate for both users and managers about directions for transdermal scopolamine patch usage to prevent delirium. And careful history taking is needed to diagnose delirium induced by transdermal scopolamine accurately.