• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.129-131
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• 1993

Power conversion system of high performance requires high switching frequency power converter. In order to minimize commutation stress and switching losses, in this paper, AC-DC converter is embedded a partial resonant DC-Link circuit with the object of ZVCS(zero voltage switching and zero current switching). The partial resonant occurs just before converter switch operates. Thus, VA ratings of the elements and their dissipations due to effective series resistance (ESR) are very low. Some simulative results on computer are included to confirm the validity of the analytical results.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.872-877
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• 2003

The fixed-angle based modified compression field theory (MCFT) was developed to include the slip deformation across the crack, thereby allowing for the non-coincident directions of the principal strain and stress. To investigate the significance of crack modelling on the analysis, a series of tests on beams without transverse reinforcement was predicted by both rotating- and fixed-angle crack models within the frame of the MCFT. The results predicted by the fixed-angle MCFT were comparable to those by the rotating-angle MCFT when the initial crack angle of 45deg. and the related friction law are used.

• JSTS:Journal of Semiconductor Technology and Science
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• v.4 no.1
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• pp.1-11
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• 2004

A FinFET, a novel double-gate device structure is capable of scaling well into the nanoelectronics regime. High-performance CMOS FinFETs , fully depleted silicon-on-insulator (FDSOI) devices have been demonstrated down to 15 nm gate length and are relatively simple to fabricate, which can be scaled to gate length below 10 nm. In this paper, some of the key elements of these technologies are described including sub-lithographic pattering technology, raised source/drain for low series resistance, gate work-function engineering for threshold voltage adjustment as well as metal gate technology, channel roughness on carrier mobility, crystal orientation effect, reliability issues, process variation effects, and device scaling limit.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.625-631
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• 1999

In this study, a series of test was conducted to show the characteristics of freezing -thawing process on soilcrete using the soft clay in a redevelopment paddy area, was treated with cement and several additives such as Beestar, CaSO4 , MgO, and polypropylene fiber, From the results of test, it was found that first addtivies -cement and beestar-was effective for compressive strength, and the resistance against freezing -thawing process was improved by secondary additives, in the order their effectiveness, i.e. CaSO4 , Synthetic fiber, MgO and Beestar.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.11a
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• pp.153-157
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• 2002

Thermal management is very important for the success of high density circuit design in LTCC. To realized more accurate thermal analysis for structure design, a series of simple thermal resistance measurement by laser flash method and parametric numerical analysis have been carried out. The design of via filled material would be useful in thermal management of power devices.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1104-1105
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• 2007

본 논문은 고압방전램프용 안정기의 점화기 4종류를 ESR(Equivalent Series Resistance)를 고려하여 등가모델링 하였다. 전자식 안정기의 구동식에 따른 풀 브리지 방식의 점화기 2종류와 하프 브리지 방식의 1종류 마지막으로 자기식 안정기의 점화기를 모델링하고 타당성을 증명하기 위해 실험을 통하여 입증하였다.

• Journal of Korean Society of Steel Construction
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• v.26 no.6
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• pp.595-604
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• 2014

In this paper, a series of experiments for the evaluation of flexural resistance of longitudinally stiffened plate girder with slender web were conducted. For the purpose, four plate girder specimens with and without longitudinal stiffener were fabricated for the web slenderness of 219 and 156. The test results were compared with the current AASHTO LRFD and Eurocode 3 codes, respectively. As presented in the previous paper by the authors, it was acknowledged that the AASHTO LRFD code could considerably underestimate the flexural resistance of longitudinally stiffened girder with slender web and the proposed method in the previous paper could estimate the flexural resistance reasonably.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.8
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• pp.2741-2749
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• 2010

This paper presents the impact damage behavior of filament wound composite vessels and the effect of surface protective materials on their impact resistance. Using an instrumented impact testing machine, a series of impact tests was performed on the base panels and the protected panels (panels with surface protective materials of rubber, kevlar/epoxy or glass/epoxy laminates) that were cut from the full scale vessel. And the impact damage parameters were used to identify the effect of protective materials on the damage resistance of composite vessels. Damage resistance of the composite vessels was considerably affected by the protective materials regardless of the shape of the indenters. Among the protective materials, glass/epoxy laminates was the most effective mean for improving the damage resistance of composite vessels.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.5
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• pp.689-696
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• 2010

Bulbous bow is one of the important design factors on the design of fore-body hull form. Using the interference technique of ship waves, the bulbous bow can decrease the wave resistance of ship. Recently, the goose neck bulb is applied mainly for high speed vessels like passenger ships and ferries etc.. Also, the goose neck bulb is applied for relatively high speed merchant vessels like container ships and LNG carriers. However, existing research papers about the goose neck bulb are not enough as reference data for the design of bow hull form. In this study, numerical calculations are carried out to investigate the bow wave characteristics of a high speed ferry with a normal high nose bulb or a goose neck bulb. By comparing the pressure distributions on the hull surface and the wave systems near the bow, the features of wave resistance reduction are discussed. Also, Numerical calculations were carried out for a series of goose neck bulbs to figure out the optimum bulb size. The maximum reduction rate of pressure resistance for the fore-body is achievable up to 8% by adopting the goose neck bulb in the present calculation.

• Journal of IKEEE
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• v.25 no.3
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• pp.467-472
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• 2021

Stable operation of semiconductor devices is needed even at high temperatures. Among the structures of semiconductor devices, the area that can cause unstable electrical responses at high temperatures is the contact layer between the metal and the semiconductor. In this study, the effect of annealing conditions included in the process of forming a contact layer of nickel silicide(NiSix) on a p-type SiC layer on the specific contact resistance of the contact layer and the total resistance between the metal and the semiconductor was investigated. To this end, a series of electrodes for TLM (transfer length method) measurements were patterned on the 4 inch p-type SiC layer under conditions of changing annealing temperature of 1700 and 1800 ℃ and annealing time of 30 and 60 minutes. As a result, it was confirmed that the annealing conditions affect the resistance of the contact layer and the electrical stability of the device.