• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제50권8호
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• pp.367-373
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• 2001

This paper presents racetrack High Temperature Superconducting (HTS) magnet with iron plates to achieve the maximum current-carrying capacity and the simple shape that can easily be wound and jointed. On the basis of the magnetic field analysis using Biot-Savart's law and 3 Dimensional Finite Element Analysis (3D FEA), this study is focused on the function of iron plates, which is to obtain smaller B${\perp}$, and stress and strain condition of Ag-sheathed Bi-2223 37-filament HTS tapes are considered. Moreover, the measured performance of the magnet with iron plates improved by 50% on the basis of initial magnet.

• Tribology and Lubricants
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• 제12권3호
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• pp.85-91
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• 1996

An analysis for turbulent hybrid beatings with fluid inertia and swirl injection effect was derived for studying static characteristics of swirl-controlled hybrid journal. The swirl-controlled hybrid journal beating is considered to have more freedom in stability control in high speed rotating machinery. Current analysis is compared with experimental results with 3-recess hydrostatic journal bearing. The analysis revealed that the fluid momentum exchange at orifice discharge could produce pressure rise inside the recess region which can control the shear flow induced by journal rotation. The analysis also shows that the swirl-controlled hybrid journal beating has a capability of controlling load carrying capacity and stability by manipulating supply pressure and injection angle.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 A
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• pp.159-161
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• 2000

This paper examines the thermal circuit of underground tunnels installed power cables. It can be appreciated to understand the mechanism of heat transfer and to calculate the current carrying capacity of power cables in tunnel.

• International Journal of Concrete Structures and Materials
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• 제5권1호
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• pp.19-28
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• 2011

This paper documents an experimental study of dynamic response of reinforced concrete beams following instantaneous removal of a bearing column. Four half-scale specimens representing two-span beam bridging across the removed column were tested. The test boundary conditions simulated rotational and longitudinal restraints imposed on a frame beam by the neighboring structural components. The gravity loads were simulated by attaching mass blocks on the beams at three locations. Dynamic loading effects due to sudden removal of a column were simulated by quickly releasing the supporting force at the middle of the specimens. The experimental study investigated the load-carrying capacity of beams restrained longitudinally at the boundaries and dynamic impact on forces. The tests confirmed the extra flexural strength provided by compressive arch action under dynamic loading. The tests also indicated that the dynamic amplification effects on forces were much lower than that assumed in the current design guideline for progressive collapse.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1280-1285
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• 2003

In the developement of LNG cargo, the current concern focuses on the slim design of insulation layer to increase the LNG carrying capacity. Not only thermal stability with BOR(Boil-Off Rate) but structual stability against the LNG weight and the sloshing phenomenon must be also considered. In this paper, we applied the stitched sandwitch composite called the 3X-Board which is stitched through the core thickness direction using glass fiber to the LNG cargo. We evaluated the thermal and structural characteristics of 3X-Board by changing the core thickness and the material, in order to explore a validity for the slim design through the finite element analysis.

• 전기학회논문지P
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• 제55권4호
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• pp.190-195
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• 2006

In this paper, safety algorithm of transformer is introduced for the sake of MV/LV distribution customers by using fuzzy theory. The current-carrying capacity of transformer is usually determined by the maximum temperature at which the transformer is permitted to operate. Overload of transformer has an effect on transformer utilization rate and maximum temperature rises as well as maximum ambient temperature of insulating materials. Therefore, we proposed the safety algorithm considering the overload of transformer and ambient temperature in this paper. We introduced the correlational equations between each parameters using experimental data of IEEE std C57.91-1995, and deduced the result using fuzzy reasoning. We guessed the safety algorithm making a diagnosis for the safety status of oil-immersed transformer.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.2029-2031
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• 2000

This paper introduces an meanings of the soil thermal properties and an probe method to analyze the soil thermal property. And its method was applied to the soils surrounding the underground transmission power cables at S/S and C/H.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 A
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• pp.174-176
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• 1993

Laying up homogeneous power cable in the earth. we sure that one of the most effectest fact is the rising of thermal resistivity. Today, system designing of in and outdoor project, calculating current carrying capacity totally depend on standard of JCS-168D and IEC-287 to applicate. Specially, the formula of calculating soil thermal resistivity is what is based on KENELLY,s is usually used. In this report, Let's study the formula of soil thermal resistivity which was born in the idea of KENELLY.

• Steel and Composite Structures
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• 제11권3호
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• pp.233-250
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• 2011

An experimental study has been carried out to reveal the shear-bond failure mechanism of composite deck slabs. Thirteen full scale simply supported composite slabs are studied experimentally, with the influence parameters like span length, slab depth, shear span length and end anchorage provided by steel headed studs. A dozen of strain gauges and LVDTs are monitored to capture the strain distribution and variation of the composite slabs. Before the onset of shear-bond slip, the longitudinal shear forces along the span are deduced and found to be proportional to the vertical shear force in terms of the shear-bond strength in the m-k method. The test results are appraised using the current design procedures. Based on the partial shear-bond connection at the ultimate state, an improved method is proposed by introducing two reduction factors to assess the moment resistance of a composite deck slab. The new method has been validated and the results predicted by the revised method agree well with the test results.

• 한국초전도ㆍ저온공학회논문지
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• 제9권1호
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• pp.57-60
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• 2007

Superconducting electric power devices need to stack HTS wires to increase the current carrying capacity. Uniform multi-stacked wires(UMS) which were made of the same HTS wires have been used. This paper shows the magnetization loss of hybrid multi-stacked(HMS) wire made of BSCCO wires and YBCO wires. Five HMS wires, YB(YBCO-BSCCO), YYBB. YBYB, YBBY and BYYB, were made and tested. Magnetization losses of each UMS wire were compared with corresponding HMS wire. Test results show that magnetization losses per unit length of HMS wire are between the corresponding UMS BSCCO wire and HMS YBCO wire below critical magnetic field. Above the critical magnetic field, magnetization losses of HMS wires are larger than that of corresponding both VMS wires.