• 한국초전도ㆍ저온공학회논문지
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• 제15권4호
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• pp.48-52
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• 2013

This paper compares the features of second generation (2G) High Temperature Superconducting (HTS) field coil with those of magnesium diboride ($MgB_2$) field coil for a 10 MW class superconducting generator. Both coils can function effectively in their respective magnetic flux density range: 10-12 T for 2G HTS field coil, 2 T for $MgB_2$ superconducting field coil. Even though some leading researchers have been developing 10 MW class superconducting generator with 2G HTS field coil, other research groups have begun to focus on $MgB_2$ wire, which is more economical and suitable for mass production. However 2G HTS wire is still appealing in functions such as in-field property and critical temperature, it shows higher in-field property and critical temperature than $MgB_2$ wire.

• 한국초전도ㆍ저온공학회논문지
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• 제15권1호
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• pp.51-54
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• 2013

This paper deals with harmonic components of the voltage on high temperature superconducting wire carrying an alternating current. HTS wire is used to manufacture superconducting power applications carrying an alternating current. Typically, international standard, IEC 61788-3 is used for critical current measurement. Thus, it is not ideal that critical current criteria in dc are adapted to superconducting power devices to decide the operating current of the devices. In this paper, we confirmed odd harmonic voltage on HTS wires carrying an AC. The ratio between harmonic components and fundamental component can be significant clues to decide the critical current criteria for HTS wire and its power applications in AC circumstance.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1632-1636
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• 2007

Generally, fine high carbon steel wire is produced using a multi-pass drawing process with speeds over 1000 m/min. The productivity of the wire drawing mainly depends on achieving the highest drawing speed without breaking the wire. In the multi-pass drawing, as the final drawing speed increases, the temperature rises several hundred Celsius. High temperature of wire increases the brittleness and leads to breaks. The objective of this study is to design pass schedule and wire drawing machine for superhigh speed. In the drawing experiment, it was possible to increase the productivity through the increase in final speed from 1100 m/min to 2000 m/min.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 제5회 압연심포지엄 신 시장 개척을 위한 압연기술
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• pp.27-36
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• 2004

Contemporary objectives for steel rod rolling processing are increasingly complex and often contrasting i.e. obtaining a desired product with optimum combination of properties such as strength, toughness and formability at lower cost. Low-alloy steel rods have been produced with several heat treatments for drawing and forging processes at room temperature. In order to reduce these heat treatments much of the researches concerning of high temperature mechanical behavior of steel rods have been conducted at wire rod mill of POSCO. In this present work, optimizations of rolling temperature and cooling rate for JS-SCM435 are performed to eliminate softening heat treatment(Low Temperature Annealing) for drawing process. The results from the optimization changed the microstructure of rods after rod rolling from Bainite with high tensile strength of 1000Mpa to Pearlite and Ferrite with appropriate strength of 750Mpa that is equivalent tensile strength after softening heat treatment.

• Journal of Magnetics
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• 제12권1호
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• pp.7-11
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• 2007

We confirm the validity of the analytic expression for the temperature of the Joule heated nano-wire [C.-Y. You et al. Appl. Phys. Lett. 89, 222513 (2006)] with finite element method. The temperature of the Joule heated nano-wire is essential information for the research of the current induced domain wall movement. The analytic expression includes an adjustable parameter which must be determined. Since the physical origin of the adjustable parameter is simplification of the heat source profile, the validity of the analytic expression must be examined for wide range of the nano-wire structure. By comparison with this analytic expression with the results of full numerical finite element method, the adjustable parameter has been determined. The numerically confirmed adjustable parameter values are in the range of 0.60$\sim$0.69, which is well matched with the theoretically expected one. Furthermore, it is found that the adjustable parameter is a slow varying function of the nano-wire geometry. Based on this numerical confirmation, we can apply the analytic expression for the wide range of the nano-wire geometry with proper adjustable parameters.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2012년 추계학술대회
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• pp.355-368
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• 2012

This paper, the hardness of the silicone rubber wire for 50, 60 degrees, 70 degrees High Temperature Vulcanizing (HTV) method using specimens were fabricated. In this paper, in order to investigate the dielectric properties of silicone rubber for wire specimens, the temperature range of $30^{\circ}C{\sim}170^{\circ}C$, the frequency range from 100Hz~4.5MHz report surveyed about the frequency and temperature dependent properties.

• Journal of Mechanical Science and Technology
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• 제14권8호
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• pp.851-860
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• 2000

Temperature field and cooling rate are important parameters to influence the properties of clad layer and the heat affected zone. In this paper the temperature field and cooling rate of laser cladding are studied by a two-dimensional time-dependent finite element model. Experiment has been carried out by Nd:YAG laser cladding with wire feeding. Research results indicate that at the beginning of cladding, the width and depth of melt pool increase with cladding time. The cooling rate is related to position, cladding time, cladding speed, and preheating temperature. The temperature near melt pool changes rapidly while the temperature far from melt pool changes slowly. With the increase of cladding time, cooling rate decreases. The further the distance from the melt pool, the lower the temperature and the slower the cooling rate. The faster the cladding speed, the faster the cooling rate. The higher the preheating temperature, the slower the cooling rate. The FEM results coincide well with the experiment results.

• 대한기계학회논문집B
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• 제20권1호
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• pp.295-303
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• 1996

A new temperature compensation technique for hot-wire anemometer is proposed in this article. In contrast to the available compensation techniques, a photoconductive cell is introduced here as a variable resistor in the bridge. The major advantage of adopting an active component such as photoconductive cell is that temperature compensation can be achieved by using any kind of temperature sensors, once the output of temperature sensor is given as a voltage. Thereby, the temperature compensation can be made automatically and intelligently by a computer software or a hardware device. Validation experiments using a photoconductive cell with a thermocouple-thermometer are conducted in the temperature range from 3$0^{\circ}C$ to 5$0^{\circ}C$ and the velocity ranges from 8 m/s to 18 m/s.

• 복식
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• 제63권4호
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• pp.132-142
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• 2013

This study has evaluated the physiological reaction to wearing brassiere as well as the sensations that the wearer feels in order to understand the effect of brassiere use on the human body. Six healthy women in their twenties were used as subjects and the experiment measured the difference in their S.C.L, Skin Temperature, B.V.P and Pulse. The measurements were made in the following conditions: Women not wearing any brassiere, women wearing sports brassiere, and the women wearing wire brassiere. The results showed significant differences in the following areas. 1. S.C.L was found to be the highest when they didn't wear any brassiere, followed by when they wore wire-brassiere and then sports brassiere. 2. The Skin Temperature was found to be the highest when they wore wire-brassiere, followed by when they wore sports brassiere and when they didn't wear any of them. In particular, when they wore sports brassiere, the B.V.P was found to be the highest when they wore none of them, fir skin temperature dropped as time passed. 3.ollowed by when they wore sports brassiere and then wire brassiere. When they wore sports brassiere, they had irregular blood-flow. 4. Pulse was found to be the highest when they didn't wear any of them, followed by when they wore sports brassiere and then wire brassiere. 5. Those who didn't wear any brassiere felt the most chill, followed by those wearing wire brassiere and then sports brassiere. The moisture level was found to be the highest when they wore sports brassiere, followed by when they wore wire brassiere and then when they wore none of them. Comfort level was found to be the best with no brassiere, followed by wire brassiere and then sports brassiere.

• 대한기계학회논문집B
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• 제20권11호
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• pp.3666-3675
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• 1996

A new hardware temperature compensation method for hot-wire anemometer is investigated and an analog compensating circuit is proposed in this article. A photoconductive cell is introduced here as a variable resistor in the anemometer bridge and the linearized output of a thermistor is used to monitor the input of the photoconductive cell. In contrast with the conventional method, any type of temperature sensor can be used for compensation if once the output of thermometer varies linearly with temperature. So the present technique can diversify the compensating means from a conventional passive compensating resistance to currently available thermometers. Because the resistance of a photoconductive cell can be set precisely by adopting a stabilizing circuit whose operation is based on the integration function of the operational amplifier, the accuracy of compensation can be enhanced. As an example of linearized thermometer, thermistor sensor whose output is linearized by a series resistor was used to monitor the fluid temperature variation. Validation experiment is conducted in the temperature ranged from 30 deg. C to 60 deg. C and the velocity up to 40 m/s. It is found that the present technique can be adopted as a compensating circuit for anemometer and hot-wire type airflow meter.