• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.527-529
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• 2001

Interfaces are the point of interconnection between distributed generation and the energy infrastructure. These interfaces are generally physical but can include a market dimension as well. While there are issues surrounding various interfaces, the most important issues in the short term are on the electrical interface. Much of the discussion and debate surrounding distributed generation interconnection has centered on technical issues. However, there are two elements of Interconnection that merit equal consideration-process and contractual issues. The solution of distributed generation Interconnection issues depends on whether existing requirements can be modified to make them more efficient, transparent, and standardized while maintaining the grid's reliability and safety. In this paper, two main courses, standardization and third party participation, are suggested for the resolution of these issues.

• Transactions on Electrical and Electronic Materials
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• 제11권4호
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• pp.178-181
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• 2010

An automotive IC voltage regulator which consists of one-chip based on a metal-oxide semiconductor field effect transistor (MOSFET) is investigated experimentally with three types of packaging. The closed type is filled with thermal silicone gel and covered with a plastic lid on the MOSFET. The half-closed type is covered with a plastic case but without thermal silicone gel on the MOSFET. Opened type is no lid without thermal silicone gel. In order to simulate the high temperature condition in engine bay, the operating circuit of the MOSFET is constructed and the surrounding temperature is maintained at $100^{\circ}C$. In the overshoot the maximum was mainly found at the half-closed packaging and the magnitude is dependent on the packaging type and the surrounding temperature. Also the impressed current decreased exponentially during the MOSFET operation.

• 한국분무공학회지
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• 제2권2호
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• pp.24-34
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• 1997

This paper describes the investigation of combustion characteristics of gasoline-methanol blend in constant volume combustion chamber. A constant volume combustion chamber was used to elucidate a basic combustion characteristics and the premixer was installed to control temperature and equivalence ratio. And the maximum pressure, combustion duration and flame propagation according to the evaporation rate were measured to determine the optimal temperature range for evaporating a blend fuel. These experimental results indicate that the combustion characteristics such as combustion chamber pressure and combustion were deteriorated by decreasing surrounding temperature of fuel. These experimental results indicate that the combustion characteristics such as combustion chamber pressure and combustion were deter orated by decreasing surrounding temperature of fuel injected. It was also found that the overall gasification process for methanol blend fuel was influenced by a combustion chamber temperature rather than a premixer temperature.

• 음성과학
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• 제8권1호
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• pp.77-91
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• 2001

This paper investigates the timing of Korean spoken in a news-reading speech style in order to improve the naturalness of durations used in Korean speech synthesis. Each segment in a corpus of 671 read sentences was annotated with 69 segmental and prosodic features so that the measured duration could be correlated with the context in which it occurred. A CART model based on the features showed a correlation coefficient of 0.79 with an RMSE (root mean squared prediction error) of 23 ms between actual and predicted durations in reserved test data. These results are comparable with recent published results in Korean and similar to results found in other languages. An analysis of the classification tree shows that phrasal structure has the greatest effect on the segment duration, followed by syllable structure and the manner features of surrounding segments. The place features of surrounding segments only have small effects. The model has application in Korean speech synthesis systems.

• Perspectives in Nursing Science
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• 제1권1호
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• pp.50-65
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• 2004

Despite the new wave of diverse philosophical thoughts in nursing, the criteria for theory evaluation rarely incorporate the new thoughts in its realm. Especially, feminist thoughts, which have contributed to the development of nursing knowledge through incorporating diversities and complexities of nursing phenomenon and reflecting social, cultural, and historical contexts surrounding nursing encounters, were rarely incorporated into the evaluation criteria. In this paper, a feminist approach to theory evaluation is proposed based on a critical analysis of the existing evaluation criteria. First, a historical review of feminist thoughts is provided, and feminist principles across diverse groups of thinking within feminism are discussed. Then, theory evaluation criteria are historically analyzed and critiqued while considering the feminist principles. The critical points found in the currently available theory evaluation criteria include: (a) the evaluation criteria are based on objectivity, (b) they are ignoring gender differences; (c) cultural differences tend not to be seriously considered; and (d) contexts surrounding nursing phenomenon are rarely considered. Based on the critical points, four additional components for theory evaluation are proposed. The components are: (a) respect for subjectivity; (b) historical and sociopolitical contextual considerations; (c) gender sensitivity; (d) cultural competence; and (e) blueprint for action.

• 설비공학논문집
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• 제14권2호
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• pp.108-115
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• 2002

The fundamental mechanism of a dispersed two-phase flow was investigated. Experiments were carried out to understand how the particles behaves under the influence of the particle size, shape, metamorphoses (bubble) and buoyancy of a single particle which is ascending from the standstill water. Two CCD cameras were employed for image processing of the behavior of the particles and the surrounding flow, which was interpreted with the technique of correlation PIV (Particle Image Velocimetry) and PTV (Particle Tracking Veloci- metry), respectively The experimental results showed that the large density difference bet- ween a particle and water caused high relative velocity and induced zigzag motion of the particle. Furthermore, the turbulence intensity of a bubble was about twice the case of the spherical solid particle of similar diameter.

• 대한조선학회지
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• 제14권2호
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• pp.1-9
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• 1977

Streamlines around a ship's hull can be calculated by using streamline tracing method replacing the ship section with distribution of singularity. The influence of frame lines on the stream surrounding a hull surface, however, can not be found. Jinnaka studied on streamlines for Lewis form by applying the slender body theory. The influence of frame lines on stream surrounding a hull surface is well found in Jinnaka's method. In this paper streamline calculation method for chine type has been developed by using conformal transformation and applying slender body theory as Jinnaka did. Three kinds of model-one of series 62 for chine type, V.L.C.C. and high speed craft built in Korea for Lewis form-were used for streamline calculation;

• 한국해양공학회지
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• 제2권1호
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• pp.125-134
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• 1988

The feasibility for improving the cooling rates and mechanical properties of wet welding process is experimentally investigated by using new developed underwater wet electrodes and H.T. steel plates. Main results of this experimental study can be summarized as follows; 1) By shielding around weld arc surrounding, the cooling rates resulting from wet welds with developed electrodes on TMCP steel plates can be lower than of non-shielded wet welds. 2)A high quality of mechanical properties of wet welds on TMCP steel plates can be obtained with shielded weld arc surrounding.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.290-292
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• 2003

The intake tower of D-dam located in a mountainous area positioned in the left side of the dam and its structure installed alone on the water surface then, can become target of direct lightening. To protect the intake tower from the direct lightening and indirect-lightening, lightening rod installed in the top area of the intake tower and ground pole laid under the surrounding ground. however, because the surrounding ground almost consists of a rock, it is very difficult to obtain the grounding resistance. It is main object to examine the construction plan of the optimum lightening rod equipment and ground pole with measuring the earth specific resistance of the around of the intake tower which is the scheduled area to lay the ground pole with the Wenner's 4-electric pole method and the Schlumberger's method. and using the analysis tool, ESII.

• 교육시설
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• 제3권1호
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• pp.53-58
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• 1996

The purpose of this study was to obtain a new guideline on designing the visual environment in the classrooms of elementary schools. This study was carried out through the field measurements on the classrooms and a survey using the questionnaire about the visual environment for learning. The major findings of the study were as follows: (1) It was unbalanced among the illumination, luminance, and color distributions in the classrooms. (2) It was too bright or dark around the surrounding surfaces (walls, floors, and ceilings) of students in the classrooms. Therefore, it is needed to be careful attention on the light distribution and the reflection ratio around the surrounding surfaces of students in the classrooms.