• 한국자동차공학회논문집
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• 제3권1호
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• pp.97-107
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• 1995

Global postbuckling analysis is accomplished for one-dimensional and two-dimensional delaminations. A new finite element model, which can be used to model the global postbuckling analysis of one-dimensional and two-dimensional delaminations, is presented. In order to calculate the strain energy release rate, geometrically nonlinear analysis is accomplished, and the incremental crack closure technique is introduced. To check the effectiveness of the finite element models and the incremental crack closure technique, the simplified closed-form sloution for a through-the-width delamination with plane strain condition is derived and compared with the finite element result. The finite element results show good agreement with the closed-foul1 solutions. The present method was extended to calculate the strain energy release rate for two-dimensional delamination. For a symmetric circular delamination, the strain energy release rate shows great variation along the delamination front. and the delamination growth appears to occur perpendicular to the loading direction.

• International Journal of Safety
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• 제2권1호
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• pp.12-16
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• 2003

In Part 1, the flame structure of the counterflow nonpremixed flames computed by using Fire Dynamics Simulator was compared with that of OPPDIF for different concentrations of methane in the fuel stream. In this study, comparisons were made for the global strain rate that is an important parameter for diffusion flames for further evaluation of FDS. At each of the three fuel concentrations, $20% CH_4＋ 80% N_2, 50% CH_4 ＋ 50% N_2, 90% CH_4 ＋ 10% N_2$ in the fuel stream, the temperature and axial velocity profiles were investigated for the global strain rate in the range from 20 to $100s^{-1}$. Changes in flame thickness and radius were also compared with OPPDIF. There was good agreement in the temperature and axial velocity profiles between the axisymmetric simulations and the one-dimensional computations except for the regions where the flame temperature reach its peak and the axial velocity rapidly changes. The simulations of the axisymmetric flames with FDS showed that the flame thickness decreases and the flame radius increases with increasing global strain rate.

• 대한기계학회논문집
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• 제7권3호
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• pp.328-334
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• 1983

The turbulent hydrogen-air diffussion flame was studied experimentally and theoretically. Laser Doppler anemometer was used to measure the velocity field in the flame. Two mathematical models for the combustion reaction term, which are infinite rate model and finite rate to be derived eddy break-up model, were tested by comparing predictions with experimental data for coaxial turbulent diffusion flame. The agreement between the predictions and the data is, on the whole, very good in the case of employing the finite rate model rather than the infinite rate model. But, it was shown that the finite rate model was practically applicable to the predictions of the turbulent diffussion flame structure.

• 동력기계공학회지
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• 제14권5호
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• pp.71-75
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• 2010

Leak detection technology is a challenging research until nowadays, because it has wide and various applications in industry. Furthermore pneumatic component reliability test based on ISO requires air leakage measurement. The conventional measurement methods need a complex operation and the calibration of leak detector. Tracing the history of our study, we proposed a new method for measurement of leak flow rate using isothermal chamber. In this study, propose a simulation model of isothermal chamber by infinitesimal flow -rate, such as a leak flow-rate. The effectiveness of the proposed simulation model is proved by simulation and experimental results. Base on the comparison results, proposed simulation model is good agreement with experimental results.

• 한국정밀공학회지
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• 제20권6호
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• pp.37-46
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• 2003

This paper is to predict quality deterioration resulting from a caulking process of yoke which is a part of automotive steering system. The caluking is a plastic deformation process involving such as impact of high speed tool, contacts between part and fixtures and strain rate sensitivity of the part material. Elaborate application of finite element method is neccesary to calculate changes of part dimensions because they fall into a level of tolerances. Simple work hardening and strain rate sensitive model is proposed fur the material and applied for the simulation by using Abaqus which is able to cater for elastoplastic rate sensitive material and contacts. Numerical results of test models that represent tensile bar and tensile plate are compared with material data inputs. Dimensional changes for the yoke are calculated from simulations and compared to the mesurements and they show good agreement. The method presented here with the material model proved to be valuable to assess quality deterioration for similar metal forming processes.

• Current Optics and Photonics
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• 제7권6호
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• pp.732-737
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• 2023

A high-power Yb-doped femtosecond (fs) fiber laser at a repetition rate of 1.83 GHz is reported. By employing a 5-stage repetition rate multiplier, the repetition rate of the mode-locked master oscillator was multiplied from 57.1 MHz to 1.83 GHz. The ultrashort pulse output at 1.83 GHz was amplified in a two-stage Yb-doped fiber amplifier, leading to >100 W of fs laser output with a pulse duration of 290 fs. The theoretical pulse width along the fiber was simulated, showing that it was in good agreement with experimental results. Further improvement in power scaling is discussed.

• 한국중재학회지:중재연구
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• 제17권2호
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• pp.189-219
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• 2007

Mediation is type of intervention in which the disputing parties accept the offer of the judge or a third party to recommend a solution for their controversy. Mediation differs from arbitration in being a voluntary resolution rather than a judicial procedure. Thus, the parties to the dispute are not bound to accept the mediator's recommendation. Resort to mediation has become increasingly frequent for civil disputes. Mediation has been successful in many cases of civil conflict. Mediation has become increasingly important for monetary disputes as well, particularly in damage cases. While most people consider mediation a far superior experience to court, everything I tell you a mediator should not do is something that at least one mediator I have dealt with has done to a client. In theory, a mediator should never share anything you tell him or her without your permission. In theory a mediator should not "spring" evaluations on anyone in a mediation without your permission (e.g. a mediator should never say "your case is worth \OOOO and I just told the other side that). In theory a mediator should not browbeat or threaten you. At the end, usually about 55% of the time with a good mediator in Kwangju Appellate Court in 2003, the parties reach an agreement that is in their best interests. If they decide to sign off on a signed agreement, the signed agreement is binding. I obviously feel mediation is a very good thing and the numbers and surveys bear me out. This article is written about how mediation is proceeded, what is the realities, what is the problem and what is the activating way. For this study, I research with legal sociological approach using Korean Judicial Year Boot judicial document and my experience as meditator in Kwangju District Court.

• 한국건설관리학회논문집
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• 제11권1호
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• pp.122-129
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• 2010

최근 공동주택 리모델링을 둘러싼 여건의 변화는 리모델링과 관련된 제도적인 변화와 거주민의 요구사항의 변화에 있다. 이 중에 제도적 변화를 제외하고 리모델링의 추진에 대한 단지 내 주민들의 의사를 어떻게 조정할 것인가가 주요한 과제로 대두되고 있다. 재건축의 대안으로서 리모델링에 대한 관심이 점차 높아지고 있지만, 그 동안의 연구들이 대부분 리모델링의 활성화에만 주력하면서 리모델링의 시행에 따라 제기될 수 있는 여러 문제점들에 대해서는 상대적으로 관심이 부족한 경향이 있었다. 그 중 주민 동의율 확보의 저해요인은 리모델링의 사업추진 및 승인과정을 어렵게 하고 있어 리모델링 사업주체와 관할 행정당국은 미처 예상치 못한 새로운 난제에 직면하고 있다. 그러므로 리모델링 사업의 활성화를 위해서는 주민의 동의율 확보를 위한 대책과 방안제시가 요구된다. 본 연구에서는 리모델링 사업추진시 주민들이 중요하게 생각하는 요인들을 규명하여 사업추진시 제약요인을 분석함으로써, 동의율을 확보하는데 효율적인 방안을 제시하고자 한다.

• Journal of Yeungnam Medical Science
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• 제22권2호
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• pp.141-149
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• 2005

Purpose: This study was conducted to assess the level of agreement among survey instruments used to study dementia and to determine the prevalence rate of suspected dementia using different instruments. Subjects and Methods: A total 171 subjects older than 65 in Gyeongju-si, Gyeongsangbuk-do, were surveyed from February to October 2003. The age, sex and educational level were examined through interview surveys, and cognitive function was evaluated using three survey instruments including MMSE-K, S-SDQ, and KDSQ. Results: The cognitive function scores obtained with the MMSE-K showed significant difference according to age. For sex and educational level significant differences were observed with all three survey instruments. The kappa index, the level of agreement between the questionnaires, was 0.302 between MMSE-K and S-SDQ, 0.401 between MMSE-K and KDSQ, and 0.762 between KDSQ and S-SDQ. The prevalence rate of suspected dementia based on the criteria suggested by MMSE-K, S-SDQ, and KDSQ was 27.5%, 15.2%, and 17.0% respectively. Conclusion: The results of this study suggest that caution is needed when comparing the measured cognitive function scores and analyzing the prevalence of dementia; this is because the prevalence of dementia and cognitive functions vary according to the questionnaires used.

• 한국기후변화학회지
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• 제9권4호
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• pp.357-368
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• 2018

The Paris Agreement, adopted in 2015, requires global mitigation actions by all countries, whether they are developed or developing countries. All member countries prepared and communicated a greenhouse gas reduction target, formally called the Intended Nationally Determined Contribution (INDC). There has been some concern regarding whether the INDCs communicated are sufficient to achieve the emissions reduction needed to hold the increase in global temperature to $2^{\circ}C$ above pre-industrial levels. How to address this emissions gap in an equitable and fair manner remains controversial. Beginning in the year 2023, global stocktaking under the Paris Agreement will be performed by the Conference of the Parties to assess progress towards temperature goals. The present study, based on various composite indicators reflecting equity, fairness, ability and efficiency, analyzed the GHG reduction targets of eleven major countries and the ambitiousness of these targets. Employing share indicators and comparative ratio indicators (resulting in eight composite indicators), this study showed that when share indicators are applied, Korea's appropriate reduction requirement rate is relatively low at 1~2%. However, when comparative ratio indicators are applied, Korea's appropriate reduction requirement rate increases dramatically to 6~11%. In a similar vein, when share indicators are applied, Korea's 2030 target is very ambitious compared to other countries, while the opposite is seen with comparative ratio indicators. This strongly suggests that Korea needs to apply more share indicators than comparative ratio indicators when discussing the equitable and ambitious role of Korea in the climate debate.