• 대한전기학회논문지:전력기술부문A
• /
• 제51권11호
• /
• pp.559-567
• /
• 2002

This paper presents the general recommendations for the overload criterions of mineral-oil-immersed distribution transformers rated 100kVA and less. For this purpose, we analyze the characteristics of top-oil temperature rising for mineral-oil-immersed power distribution transformer rated 100kVA and less, manufactured in Korea, In order to analyze the characteristics of top-oil temperature rising due to the distribution transformer loading, we performed experiments at KERI (Korea Electrical Research Institute) from December 2000 to May 2001. The restraint of ambient temperatures for the experiment results is solved using the results of foreign standards. Finally, we present the overload criterions of distribution transformer for summer and winter season, respectively.

• 한국해양공학회지
• /
• 제18권2호
• /
• pp.64-69
• /
• 2004

The characteristics of the probability distribution for mechanical properties, e.g. tensile strength, reduction of area, and elongation, for STS304 stainless steel in elevated temperature are investigated. Tensile test is performed by constant crosshead speed controls with 1mm/min. The probability distribution function of measured mechanical properties seems to follow $\alpha$ 3-parameter Weibull, and shows a slight dependence on the temperature. When the temperature is raised, the shape parameter a is increased, but both the scale parameter $\beta$ and location parameter v are decreased.

• 대한한방부인과학회지
• /
• 제25권4호
• /
• pp.38-45
• /
• 2012

Purpose: The purpose of this study is to find the factors that can affect the assessment on severity of cold hypersensitivity on hands and feet by comparing the temperature distribution among the seasons, the scan time and the laboratory temperature. Methods: We compared the temperature distribution of the arms and legs, according to the season and scan time on the basis of the results of Digital Infrared Thermal Imaging(DITI) conducted on 178 women who visited the hospital in summer and winter. We evaluated the correlation between the laboratory temperature and temperature distribution of the arms and legs. Results: The temperature distribution of the arms and legs was significantly different between summer and winter. The temperature distribution of the arms and legs was not significantly different according to the scan time. There was no significant correlation between laboratory temperature and the temperature distribution of the arms and legs in summer and winter. Conclusions: The diagnostic criteria to assess the severity of cold hypersensitivity on hands and feet need to be changed according to the season. The scan time and the small variation($24^{\circ}C{\sim}27^{\circ}C$) of the laboratory temperature doesn't affect the assessment of severity of cold hypersensitivity.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1991년도 추계학술대회 논문집 학회본부
• /
• pp.115-118
• /
• 1991

The temperature distribution on the superconducting thin-film is analyzed as moving constant field is applied above upper critical field. The distribution of magnetic field is derived in the normal spot. Governing equation is obtained with the help of the equation of conservation of energy. The temperature distribution and the heat dissipation are obtained through computer simulation by the method of numerical analysis. Maximum temperature is occured in the most right side inside normal spot. The temperature is increased abruptly inside the normal spot, and decreased more gradually outside normal spot in the direction of moving field as velocity is increased. Increasing the velocity rather than increasing magnitude of the normal spot and the applied field makes maximum temperature larger. Heat dissipation is affected by the velocity rather than the magnitude of normal spot and the applied field.

• 전기학회논문지
• /
• 제60권10호
• /
• pp.1881-1887
• /
• 2011

In this work the recyclable new polyethylene(PE) and polypropylene(PP), which are thermoplastic, have been investigated as the eco-friendly insulating candidates to replace the cross-linked polyethylene (XLPE). The temperature dependence of conductivities of these materials has been measured and its effects on electric field and space charge distribution in polymeric insulated power cable under temperature gradient have been calculated. It is shown that the sensitivity of conductivity to temperature change has more critical influence to determine the electric field distribution in the power cable than the absolute value of conductivity does and it can be said that the temperature dependence is one of most important factors for the power cable design.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
• /
• pp.1292-1295
• /
• 1987

In noninvasive temperature measurement within body, this paper is presented temperature measurement method in security and with effect from Applicator by electromagnetic, and it is analyzed heat generation quantity or temperature rise distribution by computer simulation within body. In this paper, two-dimensional model is considered and temperature distribution produced by RF capacitive heating system is analyzed by using Finit Element Method (F.E.M). A passibility of temperature distribution control is examined based on the position and size of Applicator.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 하계학술대회 논문집
• /
• pp.780-782
• /
• 2001

The mold transformer has anti-burnt and possibility of small size contrary to oil-immersed transformer. The mold transformer has generally cooling duct between low voltage coil and high voltage coil and also made by one body molding for small size and low loss. In this paper, the temperature distribution of designed 50kVA pole mold transformer for power distribution is investigated by FEM program. The designed transformer is also manufactured and temperature rise test is carried out.

• 지구물리
• /
• 제8권3호
• /
• pp.123-130
• /
• 2005

It is necessary, in the light of the importance of long-term slope stability problem, to develop a simple method or tool which can figure out the possible failure zone resulted from weathering effect and other factors. The FBG sensor system is used to estimate the correlations between the temperature and the slope in Kimhae, and to find a failure zone in slopes effectively. This research is to seek for the correlation between the soil temperature distribution and the strain distribution in a active zone by analyzing the data from the in-situ measurement so that the possible failure zone should be well defined based on the correlation. For instance, the zone of high temperature fluctuation can be regarded as one of the possible sliding zone due to the weathering effect while the constant temperature depth of the ground, if exists would not be relatively affected by the weathering process.

• 한국주조공학회지
• /
• 제28권1호
• /
• pp.25-30
• /
• 2008

To develop a functionally graded microstructure of cylindrical liner, effect of centrifugal casting parameters such as pouring temperature of hyper-eutectic Al-Si alloy melt, mold pre-heating temperature, and rotational frequency of mold on distribution of primary Si particles across wall thickness were investigated. Segregation tendency of Si particles toward inner side of cylindrical liner increased as the increase of rotational frequency of mold, pouring temperature of melt and mold pre-heating temperature. Especially, distribution density of primary Si particles within 1.5 mm from inner surface of cylindrical liner was above 35% under the centrifugal casting condition of $750^{\circ}C$ melt pouring temperature, $300^{\circ}C$ mold pre-heating temperature, and 2500 rpm mold rotational frequency.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2002년도 가을 학술발표회 논문집
• /
• pp.643-650
• /
• 2002

It is necessary, in the light of the importance of long-term slope stability problem, to develop a simple method or tool which can figure out the possible failure zone resulted from weathering effect and other factors. The FBG sensor system is used to estimate the correlations between the temperature and the slope in Yunhwajae, and to find a failure zone in slopes effectively. This research is to seek for the correlation between the soil temperature distribution and the strain distribution in a active zone by analyzing the data from the in-situ measurement so that the possible failure zone should be well defined based on the correlation. The zone of high temperature fluctuation can be regarded as one of the possible sliding zone due to the weathering effect while the constant temperature depth of the ground, if exists, would not be relatively affected by the weathering process.