• Journal of the Korean Data and Information Science Society
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• v.26 no.1
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• pp.65-75
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• 2015

This paper analyzes the determinants of wage for the college and university graduates utilizing both individual-level and industry-level variables. We note that wage determination has multi-level structure in the sense that individual wage is influenced by individual-level variables (level-1) and industry-level (level-2) variables. Then, the assumption that individual wage is independent in the classical regression is violated. Therefore, this paper utilizes the hierarchical linear model (HLM). The major results are the followings. First, the multiple correspondence analysis including level-1 and 2 variables reveals that both level 1 and level 2 variables affects individual wages judging from the fact that the values of level 1 and level 2 variables differ across the different level of individual wage groups. Second, the decision tree analysis including level-1 and 2 variables shows that the most influential variable in wage determination is industry-level wage and the next is industry-level working hour, ages and sex in the decling order in. This suggests that the utilization of the HLM is appropriate since the characteristics of industry is important in determining the individual wage. Third, it is shown that the HLM model is the best compared to the other models which do not take level-1 and level-2 variables simultaneously into account.

• Korean Journal of Construction Engineering and Management
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• v.15 no.6
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• pp.53-62
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• 2014

Recently, the number of super high-rise building projects have been increased after recovering from international financial crisis. In super high-rise building project, vertical lifting is critical to overall project productivity, due to its limited lifting equipments. Also for projects which buildings' height are higher than 400m, transfer operation in lifting is inevitable because of lifts' maximum lifting height. In transfer operation, setting a transfer floor is essential for saving lifting time of resources. In this research, using discrete event simulation modeling with AnyLogic 7.0 software and metaheuristic optimization with OptQuest software, the method of optimizing a transfer floor for workers during the morning peak time is proposed. Comparing to the result of the case which transfer floor is designated to the middle floor, setting optimized transfer floor significantly decrease the total lifting time of workers. By using proposed simulation and optimization tool, saving budget and time through increasing available working hour is expected.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.11-11
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• 2010

Thin-film-transistors (TFTs) that can be deposited at low temperature have recently attracted lots of applications such as sensors, solar cell and displays, because of the great flexible electronics and transparent. Transparent and flexible transistors are being required that high mobility and large-area uniformity at low temperature [1]. But, unfortunately most of TFT structures are used to be $SiO_2$ as gate dielectric layer. The $SiO_2$ has disadvantaged that it is required to high driving voltage to achieve the same operating efficiency compared with other high-k materials and its thickness is thicker than high-k materials [2]. To solve this problem, we find lots of high-k materials as $HfO_2$, $ZrO_2$, $SiN_x$, $TiO_2$, $Al_2O_3$. Among the High-k materials, $Al_2O_3$ is one of the outstanding materials due to its properties are high dielectric constant ( ~9 ), relatively low leakage current, wide bandgap ( 8.7 eV ) and good device stability. For the realization of flexible displays, all processes should be performed at very low temperatures, but low temperature $Al_2O_3$ grown by sputtering showed deteriorated electrical performance. Further decrease in growth temperature induces a high density of charge traps in the gate oxide/channel. This study investigated the effect of growth temperatures of ALD grown $Al_2O_3$ layers on the TFT device performance. The ALD deposition showed high conformal and defect-free dielectric layers at low temperature compared with other deposition equipments [2]. After ITO was wet-chemically etched with HCl : $HNO_3$ = 3:1, $Al_2O_3$ layer was deposited by ALD at various growth temperatures or lift-off process. Amorphous InGaZnO channel layers were deposited by rf magnetron sputtering at a working pressure of 3 mTorr and $O_2$/Ar (1/29 sccm). The electrodes were formed with electron-beam evaporated Ti (30 nm) and Au (70 nm) bilayer. The TFT devices were heat-treated in a furnace at $300^{\circ}C$ and nitrogen atmosphere for 1 hour by rapid thermal treatment. The electrical properties of the oxide TFTs were measured using semiconductor parameter analyzer (4145B), and LCR meter.

• The Journal of the Korea Contents Association
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• v.12 no.5
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• pp.541-552
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• 2012

The purpose of the study was to investigate the effects of On-Line Community Assisted Team Learning (OCATL) activities on academic achievement and team member's Shared Mental Model(SMM) subscale scores. Two studies were conducted over two semesters in different universities. The first study was aimed at examining the effects of OCATL on university students' academic achievement using pre- and post- experimental design. For this experiment, 133 university students composed of 80 male and 53 female students from 13 colleges participated. The OCATL activities included the orientation of OCATL, seminar on collaborative learning, on-line community assisted team learning with sixteen hour participation during one semester and a final report (or a term paper). To measure these students' academic achievement, their pre- and post-semester's GPA were compared. The results of paired t-test revealed a significant difference in academic achievement (p<.05). The second study was designed to compare the scores of SMM subscales of the experimental group with the OCATL activities and those of the control group without using OCATL activities. The data was collected using the scale of Shared Mental Model(SMM)-short version developed by Johnson in 2011[18]. For this study, 74 participants from 10 teams served as an experimental group and 15 teams which were not exposed to OCATL activities served as a control group. The MANOVA results showed that SMM subscores of two groups measured after the experiment were statistically significantly different: The experimental group with the OCATL activities showed high scores on general task and team knowledge, general task and communication skills, attitudes toward team and task, team dynamics and interactions, team resources and working environment, and satisfaction with the team.

• Korea journal of population studies
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• v.25 no.2
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• pp.69-105
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• 2002

This paper is aimed at three points. Firstly the size and trend of women self-employed in korea are analysed during 30 years. Second the demographic characteristics and labor condition like working hour, income and etc. of them are presented. Last, when did they begin or end their own work as their life stages were changed.

• Nutritional Sciences
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• v.7 no.4
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• pp.247-253
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• 2004

This study has investigated the effect of dietary attitudes on nutritional status of nurses living in Kyungnam province. A total of 249 muses working at hospitals in the Kyungnam area participated in this study. The general characteristics and dietary attitudes of the subjects were surveyed using a self-administered questionnaire, and nutrient intakes were examined using one day 24-hour recall method from November 14 to December 20, in 2001. The data of nutrient intakes were analyzed by the Computer Aided Nutritional Analysis Program and then the diet quality was estimated using the Index of Nutritional Quality (INQ). The subjects were classified as the high score group (17.3 %), medium score group (54.2%), and low score group (28.5%) based on dietary attitude score. The results were as follows: Average age of subjects was 27.1 years old, average nursingexperience was 5.7 years, and 70.7% of the subjects graduated from a junior college. The rate of shift work (45.4%) and non-shift work (54.6%) were similar. The average score on dietary attitudes in thehigh score group was 78.8, and those in he medium score group and in the low score group were 58.6 and 40.8 out of 100 points respectively. The average intake of energy (p < 0.001), carbohydrate (p < 0.001), protein (p < 0.05), animal protein (p < 0.01), animal fat (p < 0.05), vitamin $B_1$ (p < 0.01), vitamin $B_2$ (p < 0.0l), niacin (p < 0.001), Ca (p < 0.001), Fe (p < 0.001), animal Fe (p < 0.01), P (p < 0.001), and crude fiber (p < 0.00l), were significantly higher in the high score group than those in the medium score group and low score group. In the high score group, the average intake of protein, vitamin $B_1$, niacin, vitamin C and P were above 125% of the Korean RDA, and in medium score group, those of vitamin C and P, and in low score group, that of vitamin C were above 125% of the Korean RDA. In the high score group, nutrient of intake below 75% of the Korean RDA was Ca, and those in medium score group were vitamin $B_2$, Ca, and Fe, and those in low score group were energy, vitamin $B_2$, Ca and Fe. The intake ratio of Ca and P showed an unbalanceof 1:2, and that of animal protein/plant protein, and that of animal fat/plant fat were high (1.45-1.64) in all group;. The dietary attitude had a positive correlation (p < 0.00l) with nutrition intake except vitamin A and vitamin C.

• Restorative Dentistry and Endodontics
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• v.19 no.2
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• pp.534-548
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• 1994

The purpose of this study is to observe the corrosion characteristics of seven dental amalgams (CAULK FINE CUT, CAULK SPHERICAL, OPTALLOY II, DISPERSALLOY, HI VERALOY, TYTIN, VALIANT) through the anodic polarization curve obtained by using a potentiostat. After each amalgam alloy and Hg being triturated, the triturated mass was inserted into the cylindrical metal mold, and condensed by hydrolic pressure(160 kg/$cm^2$). Each specimen was removed from the metal mold. 24 hours after condensation, specimens were polished with the emery paper and stored at room temperature for 1 week. The anodic polarization curves were employed to compare the corrosion behaviours of the amalgam in 0.9% saline solution, Fusayama's artificial saliva, and stimulated parotid saliva at $37^{\circ}C$ with 3-electrode potentiostat. After the immersion of specimen in electrolyte for 1 hour, the potential scan was begun. The potential scan range was. -1700m V ~ + 400m V(vs. S. C. E) in the working electrode and the scan rate was 50m V /sec. The results were as follows, 1. The corrosion potential, the potential of anodic current peak, and transpassive potential in the stimulated parotid saliva shifted to more anodic direction than those in saline solution, and the current density in the stimulated parotid saliva was lower than that in saline solution. Those in Fusayama's artificial saliva was similar to those in stimulated parotid saliva. 2. The anodic polarization profiles in Fusayama's artificial saliva and stimulated parotid saliva indicated a region of slow slope current density, which is extending from the corrosion potential to the potential of anodic current peak, but that in 0.9% saline solution indicated no region of slow slope. 3. The corrosion potentials for CAULK FINE CUT, CAULK SPHERICAL, and OPT ALLOY II had the similarity in 0.9% saline solution, Fusayama's artificial saliva and stimulated parotid saliva, but those for high coper amalgam and VALIANT had no similarity. 4. The current density for TYTIN amalgam in stimulated parotid saliva was the lowest among the others. 5. As for current density, there was no significant difference between palladium enriched VALINAT and other high copper amalgams.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6627-6640
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• 2015

This study was performed to determine the complaint rates of musculoskeletal symptoms and its association with related factors among manufacturing workers. The self-administered questionnaires were given to 856 male with 50 or less employees in manufacturing industries. As a results, complaint rates of work-related musculoskeletal symptoms of the body sites was 61.2% for shoulders, 55.4% for low back, 55.3% for neck, 38.6%, for legs/feet, 32.2% for hands/wrists/fingers and 26.9% for arms/elbows. In logistic regression analysis of significant factors related with musculoskeletal symptoms of body sites, neck was related with marital status, subjective health status, smoking, drinking coffee and occupational stress, shoulders was related with job tenure, shift work, visiting out-patient department and occupational stress, arms/elbows was related with sleeping time, experience of sick absence and occupational stress, hands/wrists/fingers was related with age, smoking, drinking coffee, working hour, job position, job tenure, visiting out-patient department and occupational stress, low back was related with educational level, BMI, sleeping time, job position, job tenure, visiting out-patient department and occupational stress and legs/feet was related with marital status, job position, job tenure, history of hospitalization and occupational stress.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.2898-2907
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• 2013

The purpose of this study was to develop the creative thinking training program(CTTP) focused on a nursing case for registered nurses(RN) working at hospital, and to examine the CTTP's effects on nurses' creative thinking ability and disposition. This quasi-experimental study was conducted on the basis of pre and post-test design with a comparison group for nurses enrolled in registered nurse bachelor science degree program in a University located in Southern area of Korea. The 5 hour-CTTP, including 7 creative activity tasks related to a nursing case, was implemented on 35 RNs of the experimental group from November 21, throughout November 28, 2011. The 39 RNs were participated in this study as a control group. Pre-and post-tests were done with the questionnaire items of the Integrated Creativity Instrument for creative ability and creative disposition. There were significant differences in creative thinking ability(t=3.62, p=001) and creative disposition(t=2.91, p=.01) between the experimental and the control group. The CTTP, developed in this research would contribute to increasing creativity competency for registered nurses.

• Microbiology and Biotechnology Letters
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• v.41 no.3
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• pp.372-378
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• 2013

An alginate-degrading bacterium, identified as Shewanella oneidensis PKA 1008 by 16S ribosomal RNA sequence analysis, was isolated from the green alga Ulva pertusa. Optimal conditions for the alginate-degrading ability of its crude enzyme were then determined. The optimal culture conditions for the growth of S. oneidensis PKA 1008 were pH 9, 2% NaCl, $30^{\circ}C$, and 24 hours incubation time. The crude enzyme produced by S. oneidensis PKA 1008 showed the highest alginate-degrading activity at pH 9, $30^{\circ}C$ and produced 1.001 g of reducing sugar per liter in 3.5% (w/v) sodium alginate for 1 hour.