• International Journal of Safety
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• v.2 no.1
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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.

• Transactions of the Korean Society of Mechanical Engineers
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• v.7 no.3
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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.

• Journal of Power System Engineering
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• v.14 no.5
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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.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.6
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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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• v.7 no.6
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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.

• Journal of Arbitration Studies
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• v.17 no.2
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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.

• Korean Journal of Construction Engineering and Management
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• v.11 no.1
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• pp.122-129
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• 2010

Until now, the domestic construction market has been formed focusing on new construction and reconstruction in the apartment industry. Recently, however, the remodeling market for old structures have shown a tendency towards land shortage and land price increases in the major cities : the reinforcement of regulations regarding reconstruction ; expenditure reduction and the solving of environmental problems by regarding old structures is pursuing low costs and maximum efficiency. The interest in remodeling is increasing, however, remodeling has not been successfully initiated in the apartment division for a reasonable period of time. Consequently to acquire mutual agreement for remodeling from the residential occupants. In order to evaluate profitability, it is necessary to set priorities and reasonable criteria for remodelling and to this end, it is also required to assess each fact of remodelling in view of both customers and supplied.

• Journal of Yeungnam Medical Science
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• v.22 no.2
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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.

• Journal of Climate Change Research
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• v.9 no.4
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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.

• Geomechanics and Engineering
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• v.34 no.2
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• pp.197-208
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• 2023

Rate-dependent mechanical response of sand, subjected to loading of medium to high strain rate range, is of interest for several civilian and military applications. Such rate-dependent response can vary significantly based on the initial density state of the sand, applied confining pressure, considered strain rate range, drainage condition and sand morphology. A numerical study has been carried out employing a recently proposed visco-plastic constitutive model to explore the rate-dependent mechanical behaviour of Toyoura sand under drained triaxial loading condition. The model parameters have been calibrated using the experimental data on Toyoura sand available in published literature. Under strain rates higher than a reference strain rate, the simulation results are found to be in good agreement with the experimentally observed characteristic shearing behaviour of sand, which includes increased shear strength, pronounced post-peak softening and suppressed compression. The rate-dependent response, subjected to intermediate strain rate range, has further been assessed in terms of enhancement of peak shear strength and peak friction angle over varying initial density and confining pressure. The simulation results indicate that the rate-induced strength increase is highest for the dense state and such strength enhancements remain nearly independent of the applied confinement level.