• Structural Engineering and Mechanics
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• 제55권2호
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• pp.263-280
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• 2015

This paper describes a study of the collision of hard steel spheres against aluminium thin circular plates at speeds up to 140 m/s. The tests were monitored by a high speed camera and a chronoscope, which allowed the determination of the ballistic limit and the plate deformation pattern. Quasi-static material parameters were obtained from tests on a universal testing machine and dynamic mechanical characterization of two aluminium alloys were conducted in a split Hopkinson pressure bar. Using a damage model, the perforation of the plates was simulated by finite element analysis. Axisymmetric, shell and solid elements were employed with various parameters of the numerical analysis being thoroughly discussed, in special, the dynamic model parameters. A good agreement between experiments and the numerical analysis was obtained.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1995년도 가을 학술발표회 논문집
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• pp.258-265
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• 1995

For design of seismic isolated system the determination of isolated frequency is very important. In this paper the effects of seismic isolated frequency for cylindrical tank are investigated using the 1940 EL Centre earthquake(NS). From the results of analysis the seismic isolated frequencies significantly depend on input acceleration and displacement components in lower frequency regions. Therefore, the seismic isolated frequency should be determined by consideration of input ground motion characteristics. For the seismic analysis the modified hysteretic hi-linear model of seismic isolators which can consider the yield load variation, shape of hysterisis loop variation and hardening effects of isolators is proposed. The analyses using the proposed model give similar displacement responses but higher maximum acceleration responses than those using the simple hysteretic hi-linear model.

• Structural Engineering and Mechanics
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• 제38권5호
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• pp.593-618
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• 2011

This paper deals with the problem of the determination of the response of a viscoelastic Bernoulli-Navier beam, which is resting on an elastic medium. Assuming uniaxial bending, the displacement of the beam axis is governed by an integro-differential equation. The compatibility of the displacements between the beam and the elastic medium is imposed through an integral equation. In general and in particular in the case of a Boussinesq medium, the solution has to be pursued numerically. On the contrary, in the case of a Winkler's medium the compatibility equation becomes a linear finite relationship, which allows finding an original analytical solution of the problem for both hereditary and aging behavior of the beam. Some numerical examples complete the paper, in which a comparison is made between the hereditary and the aging model for the creep of the beam.

• Computers and Concrete
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• 제23권4호
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• pp.273-279
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• 2019

Corrosion of the rebar embedded in concrete has a fundamental role in the determination of life and durability of the concrete structures. Researches have demonstrated that artificial neural networks (ANNs) can effectively predict issues such as expected damage in concrete structures in marine environment caused by chloride penetration, the potential of steel embedded in concrete under the influence of chloride, the corrosion of the steel embedded in concrete and corrosion current density in steel reinforced concrete. In this study, data from different kind of concrete under the influence of chloride ion, are analyzed using the neural network and it is concluded that this method is able to predict the bond strength between the concrete and the steel reinforcement in mentioned condition with high reliability.

• 한국경제지리학회지
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• 제5권2호
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• pp.187-207
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• 2002

본 연구는 우리나라 광역대도시의 노동시장을 사례로, 지역노동시장이 갖는 지역성을 임금결정과정을 중심으로 고찰하였다 외환위기이후 주목을 받기 시작한 대도시내 실업과 같은 노동시장의 구조변화와 계층간의 사회적 분극화는 별개의 현상이 아니며 대도시내 노동시장과정을 통해 긴밀히 연결되어 있다. 임금결정과정에 대한 회귀분석결과, 전체적으로 고학력 및 고기능 사무직 근로자에 대한 임금상승효과가 대도시를 중심으로 두드러지게 나타난다. 이는 대도시에서 산업재구조화와 정보기술의 보급에 따른 노동시장의 수요변화와 맞물리면서 기술적.공간적 불일치에 의한 구조적 실업의 양산과 직종간의 임금격차를 유발하게 되는 것과 긴밀히 관련되어 있다. 또한 임금결정과정에 기초한 노동시장과정은 뚜렷한 지역성을 갖고 있기 때문에, 개별 광역시 노동시장내 임금결정과정과 그것이 갖는 소득변화에 대한 영향은 특정 노동시장의 특성, 즉 노동시장의 공급 및 수요구조, 산업구조 및 실업변화 등에 기초해서 이해되어야 한다 이러한 사실이 바로 지역정책으로서 노동시장정책이 올바로 정립되어야 하는 이유이며, 이는 바로 노동시장에 대한 지리학적 연구를 통해 이루어질 수 있다.

• 복식문화연구
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• 제24권6호
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• pp.825-838
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• 2016

The purpose of this study was to empirically examine the effects of salespeople's self-determination, shared value; and communication satisfaction on their job satisfaction, organizational commitment, and turnover intention in a fashion company. Questionnaires were administered to 475 salespeople who worked in fashion shop at the time of the study. The data was analyzed via factor analysis, correlation analysis, and a structural equation model. The results indicated that self-determination was extracted as autonomy, competence, and relatedness. Only the relatedness of self-determination factors was positively correlated with formal and informal communication satisfaction. In addition, recognizing hared value was positively correlated with formal and informal communication satisfaction; whereas, the practice of shared value was positively correlated with formal, but not informal communication satisfaction. Formal communication satisfaction was significantly correlated with job satisfaction and organizational commitment. Conversely, informal communication satisfaction was significantly correlated with job satisfaction, but was not related to organizational commitment. Finally, job satisfaction was significantly correlated with organizational commitment and negatively correlated with turnover intention. Moreover, organizational commitment was negatively correlated with turnover intention. The implications of this research for human resources management within fashion companies are discussed in the concluding section of this paper.

• 한국전자통신학회논문지
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• 제17권2호
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• pp.375-386
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• 2022

정보자산 보호가 조직의 중요한 관리 요인으로 인식되면서, 조직들은 정보보안 정책 및 기술 도입을 위한 투자를 높이고 있다. 하지만, 엄격한 정보보안의 적용은 조직원에게 스트레스를 통해 미준수 행동을 일으킬 수 있다. 본 연구의 목적은 정보보안 역할 강화로 인해 형성된 조직원의 스트레스가 자기결정성을 통해 준수 의도에 미치는 매커니즘을 제시하고, 개인조직 적합성을 통해 준수 의도 강화 방안을 제시하는 것이다. 연구는 정보보안 정책을 도입한 기업에 근무하는 조직원을 대상으로 온라인 설문을 하였으며, 475개의 표본을 활용하여 가설검증을 하였다. 첫째, 구조방정식 모형을 적용한 주효과 분석 결과는 역할 스트레스가 자기결정성을 감소하여 준수 의도에 영향을 미쳤다. 둘째, Process 3.1을 적용한 조절 효과 분석 결과는 개인조직 적합성이 자율성, 관계성이 준수 의도에 미치는 영향을 강화하였다. 연구는 조직원의 정보보안 스트레스, 행동 동기의 영향을 확인함으로써, 조직 내부의 정보보안 목표달성 방향을 제언한 측면에서 시사점을 가진다.

• Steel and Composite Structures
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• 제13권4호
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• pp.309-325
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• 2012

The risk of progressive collapse in steel framed buildings under fire conditions is gradually rising due to the increasing use of combustible materials. The fire resistance of such steel framed buildings is evaluated by fire tests. Recently, the application of performance based fire engineering makes it easier to evaluate the fire resistance owing to various engineering techniques and fire science. The fire resistance of steel structural members can be evaluated by the comparison of the limiting temperatures and maximum temperatures of structural steel members. The limiting temperature is derived at the moment that the failure of structural member results from the rise in temperature and the maximum temperature is calculated by using a heat transfer analysis. To obtain the limiting temperatures for structural steel of grades SS400 and SM490 in Korea, tensile strength tests of coupons at high temperature were conducted. The limiting temperatures obtained by the tensile coupon tests were compared with the limiting temperatures reported in the literature and the results of column fire tests under four types of loading with different load ratios. Simple limiting temperature formulas for SS400 and SM490 steel based on the fire tests of the tensile coupons are proposed. The limiting temperature predictions using the proposed formulas were proven to be conservative in comparison with those obtained from H-section and hollow section column fire tests.

• Wind and Structures
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• 제31권2호
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• pp.165-183
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• 2020

The first step of performance-based design for transmission lines is the determination of wind fields as well as wind loads, which are largely depending on local wind climate and the surrounding terrain. Wind fields in a mountainous area are very different with that in a flat terrain. This paper firstly investigated both mean and fluctuating wind characteristics of a typical mountainous wind field by wind tunnel tests and computational fluid dynamics (CFD). The speedup effects of mean wind and specific turbulence properties, i.e., turbulence intensity, power spectral density (PSD) and coherence function, are highlighted. Then a hybrid simulation framework for generating three dimensional (3D) wind velocity field in the mountainous area was proposed by combining the CFD and proper orthogonal decomposition (POD) method given the properties of the target turbulence field. Finally, a practical 220 kV transmission line was employed to demonstrate the effectiveness of the proposed wind field generation framework and its role in the performance-based design. It was found that the terrain-induce turbulence effects dominate the performance-based structural design of transmission lines running through the mountainous area.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2005년도 추계학술발표대회 개요집
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• pp.82-84
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• 2005

Fatigue assessment of welded structure is very sensitive to the method of local stress determination. Normally, hot spot stress which is surface stress extracted from 0.5t, 1.5t away from weld toe is widely used to obtain local stress. However, this method has a lot of limitation in the evaluation of fatigue strength. Therefore, mesh has to comply with strict requirements since stress extracted from this method strongly rely on mesh size and element types. And that method does not cover the stress gradient through thickness direction since only surface stress is considered. Recently, new method to obtain local stress is proposed, which is structural stress. This method has an advantage, which is mesh intransitiveness and covering the effect of both bending and axial stress in local area. In this paper, fatigue test data for various welded joints was analyzed to review the reliability of structural stress. As a result, it is verified that S-N curve using structural stress guaranteed single master curve for various joint type and testing condition.