• 대한화학회지
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• 제34권1호
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• pp.51-62
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• 1990

다섯 자리 Schiff base cobalt(II) 착물로서 Co(II)(Sal-DET)와 Co(Ⅱ)(Sal-DPT)들을 합성하여 비수용매에서 산소와 반응시켜 산소첨가 착물로서 [Co(III)(Sal-DET)]$_2O_2$ 및 [Co(III)(DPT)]$_2O_2$들을 합성하였다. 이 착물들은 원소분석, IR spectra, TGA, DSC 및 자화율을 측정하여 확인하였으며, 비수용매에서 이들 착물들의 산소와의 몰결합비가 첫단계는 1:1이나 시간이 경과하면 고체상태에서와 같이 1:2로 가는 $\mu$-peroxo형의 6배위 Cobalt(III)착물들이 형성됨을 알았다. Co(II)(Sal-DET)및 Co(II)(Sal-DPT)와 이들 산소첨가 착물들의 0.1M TEAP-DMSO와 0.1M TEAP-pyridine 용액에서 순환전압-전류법 및 DPP법에 의한 환원과정은 두 단계로 일전자의 비가역적인 Co(III)/Co(II)와 Co(II)/Co(I)의 과정이 주어지나 산소첨가 착물에서 산소결합의 환원전위는 $E_{pc}$ = -0.97V∼-0.86V이고 이에 couple인 산화전위는 $E_{pa}$ = -0.87V ∼ 0.64V에서 일전자의 준가역적 산화환원 과정으로 일어남을 알았다.

• 소성∙가공
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• 제8권1호
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• pp.57-64
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• 1999

The press formability analysis of welding parts was studied in the current work by the tailor welded blank. As the body panel is used in the press forming of welding parts by a weld method of the tailor welded blank, the following conditions are demanded: 1) The strength of welding parts must be the higher than base metals. 2) After the welding, severe welding deformatins must be avoided. 3) The press formability of welding parts is similar to that of many base metals. 4) The productibility of a welding has to be higher. There are many welding methods satisfying these conditions, but the purpose of this study is to inbestigate the upset weldability and formability of the material (SPCC). SPCC steel sheet showed good weldability and formability under some welding conditions. The experimental results were discussed by the evaluation of the results obtained from tensile tests, hardness tests, micro-structures and Erichsen cup test was a little lower than that of parent material.

• Earthquakes and Structures
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• 제10권6호
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• pp.1273-1289
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• 2016

This paper addresses the concept of lateral overstrength; the ratio of actual lateral strength to design base shear force, for both SDOF and MDOF systems considering soil structure interaction. Overstrength factors are obtained with inelastic time history analysis for SDOF systems for period range of 0.1-3.0 s, five different aspect ratios (h/r=1, 2, 3, 4, 5) and five levels of ductility (${\mu}$=2, 3, 4, 5, 6) considering soil structure interaction. Structural overstrength for MDOF systems are obtained with inelastic time history collapse analysis for sample 1, 3, 6, 9, 12 and 15 storey RC frame systems. In analyses, 64 ground motions recorded on different site conditions such as rock, stiff soil, soft soil and very soft soil are used. Also lateral overstrength ratios considering soil structure interaction are compared with those calculated for fixed-base cases.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 가을 학술발표회 논문집
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• pp.64-69
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• 1996

As Waste-concretes generated in construction field are increasing, it is becoming difficult and expensive to dispose them. For environmental reasons, many attempts have been made to find ways of reusing these materials. However, very little waste-concrete is currently recycled or reused anywhere on the world. Recycled concrete is mainly used as nonstabilized base of sub-base in highway construction. In this study, in order to promote the reuse of the waste-concretes, no-fines concrete blocks using recycled concrete aggregates were produced and their properties are evaluated. From the test results about strengths, pemeability, and durability, it is known that to use recycled aggregates for construction goods is promising and economical.

• 한국안전학회지
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• 제12권2호
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• pp.57-64
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• 1997

Fatigue crack propagation behaviors and life prediction for SUS 321 plate and its electron beam weld metal were investigated using compact tension specimens. The larger the stress ratio is, the faster the crack propagates, but the variation of crack propagation rate decreases. The effect of stress ratio is greater in the slow crack propagation area than in the faster one. The crack propagation rate of electron beam weld metal is faster than that of base metal because of hardening, weld defect and residual stress in welding area. The crack propagation rate of transverse weld metal has a lower than that of base metal due to the effect of residual stress, but in the time of passing through welding area, has a higher rate. The crack propagation rate using $\Delta$K$_{eff}$ can be well plotted regardless of stress ratio. The fatigue life prediction method of considering crack closure more exactly predicts fatigue life than conventional one. conventional one.e.

• 대한물리의학회지
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• 제13권3호
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• pp.121-132
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• 2018

PURPOSE: This study was conducted to investigate the effects of type of exercise on neck disability, pain, and postural changes in subjects with forward head posture. METHODS: Two independent researchers conducted a search using KISS, RISS, DBpia (domestic), PubMed, OVID, and Science Direct (overseas) databases. We selected randomized controlled clinical trials by searching using the terms "forward head posture", "exercise therapy", and "therapeutic exercise". Studies published from 2007 to December 2017 were included. PEDro Scale was used to evaluate the quality of the selected studies, and meta-analysis was conducted using the CMA program. This review was registered at PROSPERO (CRD42018068633). RESULTS: Of the total 13768 studies searched, 17 were selected. Positive effects on neck disability were achieved with the base and biomechanical elements (ES=1.63, 95% confidence interval [CI] .49 to 2.75) as well as base, modulator, and biomechanical elements (ES=1.50, 95% [CI] .69 to 2.30). Neck pain improved with the base, modulator, and biomechanical elements (ES=1.96, 95% [CI] 1.08 to 2.82), while postural changes improved with biomechanical elements (ES=1.45, 95% [CI] .64 to 2.25). Additionally, type of exercise had a positive effect. CONCLUSION: The most effective exercises for neck disability are of the base and biomechanical elements, while the most effective types for neck pain are of the base, modulator, and biomechanical elements and the most effective exercise for posture is of biomechanical elements. Combined exercises targeting biomechanical elements were effective at treating disability, pain, and postural changes.

• Journal of Welding and Joining
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• 제31권1호
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• pp.58-64
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• 2013

The following results were obtained, microstructures and tensile properties in arc brazed joints of DP(dual phase) steel using Cu-5.3wt%Sn insert metal was investigated as function of brazing current. 1) The Fusion Zone was composed of ${\alpha}Fe+{\gamma}Cu$ and Cu23Sn2. The reason for the formation of these solid solutions. Despite, Fe & Cu were impossible to solid solution at room temperature. It's melting & reaction to something of insert metal & Base Metal (DP Steel) by Arc. Brazing Process has faster cooling rate then Cast Process, Supersaturated solid solution at room temperature. 2) The increase Hardness of Fusion Zone was directly proportional to the rise of welding current. Because, ${\alpha}Fe+{\gamma}Cu$ phase (higher hardness than the Cu23Sn2.(104.1Hv < 271.9Hv)) Volume fraction was Growth, due to increasing the amount of base metal melting by High current. 3) The results of tensile shear test by Brazing, All specimens happen to fracture in Fusion Zone. On the other hand, when Brazing Current increasing tend to rise tensile load. but it was very small, about 26-30% of the base metal. 4) The result of fracture analysis, The crack initiate at Triple Point for meet to Upper B.M/Under B.M/Fusion Zone. This Crack propagated to Fusion zone. So ruptured by tensile strength. The Reason to in the fusion zone fracture, Fusion zone by Brazing of hardness (strength) was very lower then the base metal (DP steel). In addition the Fusion Zone's thickness in triple point was thin than the base metal's thickness in triple point.

• 한국식품조리과학회지
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• 제2권1호
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• pp.59-64
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• 1986

This study was designed to revive the disappeared Younsa and to investigate the optimum processing condition and characteristics of Younsa nade of the glutinous rice powder. Agitating time of base mixture, thickness of Younsa base, and frying time were examined as the influencing factors in Younsa processings. The textural parameters of Younsa were determined by sensory cvaluation and hardness of Younsa was measured by Rheometer. The results were found as follows; 1. In the sensory evaluation, 1) The Younsa base agitated for 10 minutes by agitating machine was favorable. It, however, did not showed any significant difference among products prepared under varying agitaing time-10 minutes, 20 minutes, and 30 minutes. (p<0.05) 2) The thinnest Younsa base (5 cm$\times$4cm, 1.1-1.5g) showed the most favorable quality and the second quality went to 5cm$\times$4cm, 1.6-2.0g, the third 5cm$\times$4cm, 2.1-2.5g, the fourth 5 cm$\times$4 cm, 2.6-3.0g. (p<0.05) 3) In examination of varying frying time, the optimal time for frying Younsa was 12 minutes was 12 minutes in $150 ^{\circ}C$. However, the quality was found no significant difference between 12 minutes's fried Younsa and 14 minutes's. (p<0.05). 2. The hardness of the most favorable Younsa, agitated for 10 minutes, the thinnest (5 cm$\times$4 cm, 1.1-1.5g), ana fried for 12 minutes in $150^{\circ}C$ was 0.59-0.73 kg/wt measured by Rheometer. The thickest Younsa base (5 cm$\times$4 cm, 2.6-3.0g) is the hardest (1.26 kg/wt). The most optimal conditions in this experiment were found the same ones which was written in historical literature.

• Structural Engineering and Mechanics
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• 제64권6권
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• pp.731-736
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• 2017

Friction Pendulum isolators are tools developed in the past few decades. The simplest form of these isolators, are FPS whose main disadvantages are having a constant frequency independent of the frequency of the structure. For this reason, researchers have invented VFPI isolator whose frequency is variable and depends on displacement. Another friction pendulum isolator is DCFP isolator which is a combination of two FPS isolators. In this article, first by changing the geometry of DCFP isolator plates from spherical to elliptical, the motion and frequency equations of DVFPI isolators are defined, and then the seismic behavior of DVFPI isolators are analyzed in various geometric and plate friction settings using motion equations, and confirmed using ABAQUS software. The most important results of this study are that the hysteresis behavior of DVFPI isolators are severely nonlinear, its curve follows two distinct curvatures, and that the restoring force is faced with softening mechanism that limits the seismic force transmitted to the structure, whereas the restoring force in DCFP isolators increases linearly with increasing displacement.

• 산업경영시스템학회지
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• 제37권3호
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• pp.64-74
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• 2014

We show how a supplier can peg cost measures to the reliability of his time guarantees via the penalty costs considered in the framework. The framework also enables us to study the connections between the logistics network and the market. In this context, we show that even when the market base increases significantly, the supplier can still use the logistics network designed to satisfy lower demand density, with only a marginal reduction in profit. Finally we show how the framework is useful to evaluate and compare various logistics system improvement strategies. The supplier can then easily choose the improvement strategy that increases his profit with the minimal increase in his logistics costs.