• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.132-137
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• 2000

A complete theoretical treatment of the photothermal displacement technique has been performed for thermal diffusivity measurement in solid materials. The influence of parameters - radius and modulation frequency of pump beam and thickness of material - on the phase lag was studied. The phase decreases up to a certain position, then starts to increase and does have an asymptotic value. The position, where phase has the minimum value, is a function of thermal diffusion length thickness of sample, and radius of pump beam. A new method based on minimum phase lag is described to determine the thermal diffusivity of solid material.

• Nuclear Engineering and Technology
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• 제32권2호
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• pp.99-107
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• 2000

A probabilistic integrity analysis method is presented for a reactor vessel under pressurized thermal shock(PTS) based on Monte Carlo simulation. This method can be applied to the structural integrity assessment of a reactor vessel subjected to pressurized thermal shock where the coolant temperature transient cannot be expressed explicitly as a time function. An axially or circumferentially oriented infinite length surface crack is assumed to be in the beltline weld region of the rector vessel's inside surface. The random variables are the initial crack depth, neutron fluence on the vessel's inside surface, the copper and nickel content of the vessel materials, R $T_{NDT}$ , $K_{IC}$ , and K/aub la/. The reliability of a sample reactor vessel under PTS is assessed quantitatively and the influence of the amount of neutron fluence is also examined by applying the present method.sent method.

• 한국의류학회지
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• 제27권3_4호
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• pp.384-394
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• 2003

The purpose of this research is to provide the apparel companies with a successful business strategy by analyzing the concept, function and current status of mileage programs; and examining how customer's attitude, recognition, experience, compensation method of the mileage program in apparel companies affect its brand loyalty. In this research simple random sampling was performed. The sample pool was based on 494 people which included college students and employed men and women in their twenties and thirties living in Seoul and in the metropolitan area. The data analysis was completed on the basis of SPSS package, using frequency, percentage, mean, standard deviation, factor analysis, variation, Scheffe test, regression, t-test, and X/sup2/. The following results were found in this research: It is effective to maintain brand loyalty through continuous relationship with consumers as fierce competition increases in apparel companies. A mileage program is a win/win strategy that allows clothing companies to increase its sales and brand loyalty while consumers feel greater satisfaction.

• 한국재료학회지
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• 제17권10호
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• pp.532-537
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• 2007

A series of wet grinding experiments have been carried out using a stirred ball mill to systematically investigate consideration of grinding characteristics. The particle size distribution and median diameter of the grinding consumption power for a given grinding time were considered. Also, the effect of grinding aids on particle size and grinding consumption energy defined as the summation of grinding power was investigated. The grinding aids had influence on the smaller products size and decrease grinding consumption energy because the function of grinding aids were to be attribute to the prevention of agglomeration and ball and grinding chamber wall coating of sample powder. The grinding process seemed to be controlled by the force of agglomeration of the ground products. It was demonstrated that the particle size and grinding consumption energy could be more decreased by the addition of grinding aids.

• 한국의류학회지
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• 제43권3호
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• pp.327-348
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• 2019

Among the many methods to make sustainable garments, convertible garments have the potential to change style and function that allow consumers to keep and use garments longer with the possibility of enhancing sustainability. This research analyzes consumer preferences in changeable design options for convertible dresses and the consumers' influence on environmentally responsible apparel consumption (ERC) behaviors on their preferences regarding changeable design options of dresses, which are popular items. An online survey collected data from a convenient sample of 321 female college students from four universities in the United States. Data were analyzed using IBM SPSS through descriptive analysis, cluster analysis, and independent samples t-test. There were significant differences between high and low ERC groups in design preferences that considered important aspects of purchasing, using convertible dresses, and purchase intentions. Detailed differences among sub-groups were analyzed. Designers are encouraged to make tying/folding/wrapping dresses with changes of size/fit, dress length, or color/pattern. The results are beneficial for apparel designers when developing convertible dresses with the guidance of consumers' design preferences and differences according to ERC levels.

• 대한한의학회지
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• 제20권4호
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• pp.39-49
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• 2000

This study was conducted to prove that there exists a relation between the spleen and learning and memory as Oriental medicine believesTo promote the function of the Spleen, Guibitang was administered to rats in this study. Rats were 250～300g Sprague-Dawley, and were divided into three groups. One was the normal group without any pretreatment. Another was the control group which was administered normal saline and the abdominal injection of L-NAME before learning and memory test. And the 3rd was the sample group, to which was administered Guibitang extract and (no 'the') abdominal injection of L-NAME before the learning and memory test. Each group was made up of 12 rats. Morris water maze and radial arm maze tasks were performed in the learning test and Morris water maze task in the memory test. For 2 days to evaluate the ability of learning in the Morris water maze, 16 trials were carried out and first latency(lapse time to find the escape platform for the first time) was measured. The next day, to evaluate the ability of memory, the escape platform was eliminated from the maze, and total path, target entry number, first latency and memory score were measured. 48hrs before the radial arm maze task was performed, bait was deprived from each group. After learning test, bait was permitted to each group. So 85% of the body weight was maintained for 6 days of the test. Each of the eight arms was baited; correct choice numer and error were counted; each trial was finished when the rat had entered each of the eight arms, or more than 10 minutes had elapsed. The results were as follows: In the learning test, the first latency of the sample group in the Morris water maze showed evident improvement of learning compared to control group at the 11th, 12th, 13th trial of 16 trials, and correct choice number in radial arm maze showed noticeable improvement compared to the control group at 3rd, 4th and 5th; In the memory test, the memory score of the sample group showed evident improvement compared to the control group. From the above results, the administration of Guibitang, which tonifies the function of the Spleen, could enhance the ability of learning and memory. So it was suggested that the Spleen has a relation with learning and memory.

• 산경연구논집
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• 제10권9호
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• pp.53-60
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• 2019

Purpose - The objective of this paper is to discover if there exists a relationship between the economic index and distribution industry index in Korean. Because of the distribution industry boom in the recent years, a lot of interest in the relationship between the economic index and distribution industry index in Korean and the economy has been generated. This article examine on the mutual influence between economic index and distribution industry index in Korean. Research design, data, and methodology - For this purpose, we use the vector-auto regression model, impulse response function and variance decomposition of the economic index and distribution industry index, Granger causality test using weekly data on the economic index and distribution industry price index in korea. The sample period is covering from January 2, 2010 to August 31, 2019. The VAR model can also be linked to cointegration analysis. Cointegration Analysis makes possible to find a mechanism causing x and y to move around a long-run equilibrium (Engle and Granger, 1987). This equilibrium means that external shocks may separate the series temporarily at any particular time, but there will be an overall tendency towards some type of long-run equilibrium. If variables are found to have this tendency they are said to be cointegrated and a long-run relationship between these series is established. These econometric tools have been applied widely into economics and business areas to analyze intertemporal linkages between different time series. Results - This research showed following main results. First, from the basic statistic analysis of the economic index and distribution industry index in Korean, the economic index and the distribution industry index in korea have unit roots. Second, there is at least one cointegration between the economic index and distribution industry index in Korean. Finally, the correlation between of the economic index and the distribution industry index in korea is (+) 0.528876. Conclusions - We find that the distribution industry price index Granger cause the economic index in korea. As a consequence, the distribution industry index affect the economic index in Korean. The distribution industry index to the economic index is stronger than that from the economic index to the distribution industry index.

• 약학회지
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• 제39권6호
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• pp.636-644
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• 1995

Comparison of bioavailabflity (BA) of three brands of ranitidine (RT) tablets has been studied m rats. The purpose of this study was to characterize the pharniacolunetics of RT tablets in the rat and to coinpare phannacolunetic parameters of three brands of RT tablets. In addition, it was investigated whether plasma RT concentrations m humans can be predicted from pharmacokinetic parameters obtained in rats. RT was administered intravenously in dose of RT.HCI 10mg/kg and orally in dose of RT.HCI 50mg/kg as solution or crushed sample of thablets. Plasma RT concentrations were determned by HPLC. Plasma RT concentrations as a function of time were fitted to two compartment model. Plasma RT concentrations declined with a terminal half life ($t_{{1}/2{\betha}}$) of 40.9 min. The plasma RT concentration-time curve showed two peak plasma concentrations following an oral administration of solution or crushed sample in rats like humans. No significant difference among pharmacokinetic parameters was observed except $T_{max2}$ (p<0.05). The BA for crushed sample A, B and C were found to be 54.6 40.7 and 40.0%, respectively. Equivalence of $C_{max1}$ and $T_{max2}$ were guaranteed in this study. However, it was concluded that three brands of RT tablets are bioequivalent, taking the following characteristics of RT into consideration;(1) rapid onset of the effect is not required, (2) $C_{max1}$ and $T_{max2}$ do not seem to influence the effectiveness of the drug during a long-term treatment by the usual administration of twice a day. Results from this study were combined with plarmacokinetic data for RT in dogs and humans to develop a basis for interspecies scale-up of the disposition characteristics of the drug. there were similarities in the general disposition of the drug. Allometric relationships were sought between pharmacokinetic parameters nd species body weight. Significant interspecies correlations were found for total body clearance($Cl_{t}$) and steady state volume of distribution ($Bd_{ss}$). Thus, plasma RT concentrations in humans can be predicted from pharmacokinetic parameters obtained in rats.

• Geomechanics and Engineering
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• 제11권4호
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• pp.493-513
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• 2016

A modified grey clustering method is presented to systematically evaluate the risk of water inrush in karst tunnels. Based on the center triangle whitenization weight function and upper and lower limit measure whitenization weight function, the modified grey evaluation model doesn't have the crossing properties of grey cluster and meets the standard well. By adsorbing and integrating the previous research results, seven influence factors are selected as evaluation indexes. A couple of evaluation indexes are modified and quantitatively graded according to four risk grades through expert evaluation method. The weights of evaluation indexes are rationally distributed by the comprehensive assignment method. It is integrated by the subjective factors and the objective factors. Subjective weight is given based on analytical hierarchy process, and objective weight obtained from simple dependent function. The modified grey evaluation model is validated by Jigongling Tunnel. Finally, the water inrush risk of Shangjiawan Tunnel is evaluated by using the established model, and the evaluation result obtained from the proposed method is agrees well with practical situation. This risk assessment methodology provides a powerful tool with which planners and engineers can systematically assess the risk of water inrush in karst tunnels.

• 한국환경보건학회지
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• 제43권5호
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• pp.370-381
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• 2017

Objectives: The rate at which the nationwide highway is outsourcing the duties of toll gate cashiers to the public is increasing. The aim of this study is to conduct research on job stress for the rate at which the fares are collected by national highway toll gate cashiers. Methods: The population selected was a statistically significant group making up 10% of the total number of people surveyed in 2015, with a population of approximately 5,495 persons. The sample size is intended to cover the maximum sample size of 550 samples and the maximum number of samples that should be obtained. After allocating the number of samples by quota allocation, the qualitative function of Quality Function Deployment (QFD) was applied by random sampling. Results: Job stress ranked at $46.6{\pm}11.5$ points was found to be under the stress of 50% reported in other occupations. Job stress items showed higher for "job instability" compared to other types of tasks. Also, it appeared lower in "conflict in relationships." This is a result of the work characteristics of highway service operators. Conclusions: Time was found to have the highest influence on the workload (${\beta}=0.80$, p. 0.001), which calls for a reduction in time and workload. est influence on the workload (${\beta}=0.80$, p. 0.001), which requires a reduction in time and workload.