• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2714-2719
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• 2007

HANARO, an open-tank-in-pool type research reactor of 30 MWth power in Korea, has been operating normally since its initial criticality in February, 1995. For the last about ten years, A cooling tower of a secondary cooling system has been operated normally in HANARO. Last year, the cooling tower has been overhauled for preservative maintenance including fills, eliminators, wood support, water distribution system, motors, driving shafts, gear reducers, basements, blades and etc. This paper describes the results of the overhaul. As results, it is confirmed that the cooling tower maintains a good operability through a filed test. And a cooling capability will be tested when a wet bulb temperature is maintained about 28 $^{\circ}C$ in summer and the reactor is operated with the full power.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.1
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• pp.71-77
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• 2003

This research has been conducted to collect regional ecotypes of Poa pratensis throughout the southern part of korean peninsula during 2000~2002. 227 local ecotypes of Poa pratensis were collected mostly from roadsides, riversides and rice paddies. The $35^{\circ}$ latitude was supposed to be the southern limit of native Poa pratensis habitat. 130 ecotypes of Poa pratensis found from the poor environmental condition such as roadsides showed Poa pratensis naturally grew throughout the country. When surveyed the habitat environment, it was concluded that native Poa pratensis were mostly found on open fields or half shaded areas, on sandy soil or sandy loam soil, and in the individual patch type.

• Solar Energy
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• v.12 no.1
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• pp.95-102
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• 1992

A small scale solar collector system composed of a Fresnel lens of $0.5m^2$ area as a solar concentrator and a compact fluidized-bed solar receiver was developed. Performance and temperature distribution in the fluidized bed receiver were measured using SiC for particles and air for working fluid. The maximum gas temperature was attained up to 1250K at this moment. In this study, energy efficiency achieved by the present experiment was high for the small scale solar collector system and compact receiver.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.650-652
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• 2000

Proposed slotless PM machine is constructed without stator winding slots. Its stator magnetic material is in the form of a ring and winding have a toroidal configuration and its rotor consists of a 4-pole Halbach array or radially magnetized PM rotor. Thus, airgap flux density distribution and induced emf waveform are essentially sinusoidal. Open circuit magnetic fields and developed torque of each type are presented from the analytical method and finite element method.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.37-39
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• 1998

The hybrid step motor has found applications in a wide range of mechanical systems as a low cost, open-loop positioning device. The step motor provides good stiffness at rest against disturbing load influences, a combination of moderate speed fine resolution, high reliability and simplicity. In recent years, considerable competition has arisen over the technological issue of wheather the device should be applied as a 2-Phase or 5-Phase machine. In this paper, to compare two systems, we have atempted to derive the mathematical. model, and analysed operating detent torque with this model. The analysis shows that a fundamental component of the permeance distribution produces the average torque and that harmonic components produce the ripple torque.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.288-291
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• 2004

The spray characteristics of coaxial swirl injector under ambient high pressure conditions were investigated in this paper. Three injectors were used to study the effect of recess length and fuel injector type(open or closed). In this research, experimental conditions(ambient gas density) were calculated by Buckingham Pi-theory and spray characteristics of the injectors were represented by mass flow rate according to the injection pressure, the spray angle, mass distribution, and mean diameter of droplet.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.25 no.4
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• pp.35-44
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• 2012

Objectives : This study was aimed to evaluate the treatment effect of psoriasis patient using pyretotherapy. Methods : The clinical study was performed using retrospective observational research method. Treatment method was pyretotherapy that optimized core temperature through herbs therapy, food therapy, excercise and life style change. In other aspects, pyretotherapy is skin cure therapy that rise core temperature, down skin temperature and open sweat gland. Results : 1. 40s years showed the most coming of clinic in the distribution of age of psoriasis patient. 2. Board type showed the most number in the classification of psoriasis. 3. Pyretotherapy was very effective results in psoriasis patient treatment. 4. Pyretotherapy showed effects of rising axillary temperature and moving facial high skin temperature toward abdominal portion. Conclusions : The author is able to say that it is possible for pyretotherapy to become new skin therapy for many skin disease, especially psoriasis.

• Journal of Korea Spatial Information System Society
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• v.1 no.2 s.2
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• pp.63-80
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• 1999

This study presents NGDM(National Geospatial Information Distribution Model) in order to effectively utilize and differently apply geospatial information which is important in the dispersion of GIS. In order to establish the NGDM, this study draws the guideline of NGDM in Korea by analyzing its present condition of domestic and foreign geospatial information distribution. It also investigates some major factors forming the infrastructure of NGDM in regulative, technical, physical, and social aspects. Based on these factors, this study presents a three-staged NGDM that is applicable in Korea. The NGDM consists of four components that are the consumer, supplier, gateway for the clearinghouse and the clearinghouse of the geospatial information. According to the management form of geospatial information, the types of NGDM are classified as the concentration type, the distribution type, and compound type. Also, this study explains the mutual relationship between the NGDM's components and suggests a three-staged NGDM of planting, growth, and maturity period considering comparison results of classified models and development direction of regulation, protocol, communication network, electronic commerce, and etc.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.6 s.97
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• pp.571-579
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• 2005

This paper presents the classical site attenuation characteristics of a forced resonant electromagnetic interference (EMI) dipole antenna for frequencies below 80 MHz. The coupled integral equations for unknown current distribution are solved by the Galerkin's method of moments with piecewise sinusoidal functions. The results show that the forced resonant type EMI dipole antenna for frequencies below 80 MHz can be used effectively for measuring the classical site attenuation of horizontal polarization. The theoretical site attenuation curves presented can be used as reference curves for evaluating the performance of an open area test site.

• Progress in Superconductivity and Cryogenics
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• v.14 no.1
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• pp.25-29
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• 2012

The novel type of cable under consideration is cooled by gaseous Helium at elevated pressure. Helium is known for having poor electric breakdown strength; therefore the dielectric capabilities of this type of cable must be tested under conditions similar to the envisaged operation. In order to study the dielectric performance we have designed and built a novel high pressure cryostat rated at 2.17 MPa which has been used for testing model cables of lengths of up to 1 m. The cryostat is an open system where the gas is not re-circulated. This allows maintaining a high purity of the gas. The target temperature range is between 40 K and 70 K. This substantially increases the critical current density of the HTS compared to 77 K, which is the typical temperature of cables cooled by liquid nitrogen. The cryostat presented allows for adjusting the temperature and keeping it constant for the time necessary to run a complete dielectric characterization test. We give a detailed description of the cryostat. Measurements of partial discharge inception voltages as well as the temperature distribution along the model cables as a function of time are presented.