• Korean Journal of Culture and Social Issue
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• v.15 no.4
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• pp.565-589
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• 2009

The present study explored the major components of adaptive game behavior among adolescents in Korea. Based on relevant research and a pilot testing, an Adaptive Game Use Scale (AGUS) was developed and validated. A stratified sampling procedure was used to draw a representative sample, and a total of 600 male and female students from middle schools and high schools in various regions participated in the study. Factor analyses revealed 7 facets of adaptive game behavior, including experiencing vitality, expanding life experience, making good use of leisure time, experiencing flow, exercising control, experiencing self-esteem, maintaining and expanding social network. Internal consistency and temporal stability(4 weeks) of the scale were both high. A confirmatory factor analysis indicated that a 7-factor hierarchical model fits well with the data. Moreover, additional analyses suggested that AGUS and game addiction are conceptually distinct. Correlational analyses also indicated that AGUS has good discriminant validity and concurrent validity. Implications of the findings and future directions were discussed.

• Annals of Occupational and Environmental Medicine
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• v.35
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• pp.13.1-13.12
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• 2023

Background: Indoor air pollution can cause and exacerbate asthma. We report a previously undescribed case of occupational asthma related to indoor air pollution in a worker at an indoor air gun shooting range and highlight the potential risk of developing occupational asthma in this environment. Case presentation: A 31-year-old man presented with dyspnea, cough, and sputum and was diagnosed with asthma complicated by pneumonia. Objective evidence of asthma was obtained by performing a methacholine bronchial provocation test. It was suspected that the patient had occupational asthma, which began one month after changing jobs to work within the indoor air gun shooting range. The highest peak expiratory flow (PEF) diurnal variability on working days was 15%, but the highest variation was 24%, with 4 days out of 4 weeks having a variation of over 20% related to workplace exposure. Conversely, the diurnal variability on the rest days was 7%, and no day showed a variation exceeding 20%. The difference in the average PEF between working and rest days was 52 L/min. PEF deterioration during working days and improvement on rest days were noted. Conclusions: The results obtained from the in-depth analysis of the PEF were adequate to diagnose the patient with occupational asthma. Exposure to indoor air pollution and lead and the patient's atopy and allergic rhinitis may have contributed to the development of occupational asthma.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.2
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• pp.221-227
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• 2016

The main shaft is one of the key components connecting the rotor hub and gear box of a wind power generator. Typically, main shafts are manufactured by open die forging method. However, the main shaft for large MW class wind generators is designed to be hollow in order to reduce the weight. Additionally, the main shafts are manufactured by a casting process. This study aims to develop a manufacturing process for hollow main shafts by the open die forging method. The design of a forging process for a solid main shaft and hollow shaft was prepared by an open die forging process design scheme. Finite element analyses were performed to obtain the flow stress by a hot compression test at different temperature and strain rates. The control parameters of each forging process, such as temperature and effective strain, were obtained and compared to predict the suitability of the hollow main shaft forging process. Finally, high productivity reflecting material utilization ratio, internal quality, shape, and dimension was verified by the prototypes manufactured by the proposed forging process for hollow main shafts.

• The Journal of Engineering Geology
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• v.8 no.2
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• pp.175-188
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• 1998

This paper describes the internal structures and K-Ar ages of fault gouges collected from the Dongnae fault zone. This fault zone is internally zoned and occurs in the multiple fault cores. A fault core consists of thin gouge and narrow cataclastic zones that are bounded by a much thicker damage zone. Intensity of deformation and alteration increases from damage zone through cataclastic zone to gouge zone. It is thought that cataclasis of brittle deformation was the dominant strain-accomodation mechanism in the early stage of deformation to form the gouge zone and that crushed materials in the regions of maximum localization of fault slip subsequently moved by cataclastic flow. Deformation mechanism drastically changed from brittle processes to fluid-assisted flow along the gouge zone as the high porosity and permeability of pulverzied materials during faulting facilitated the influx of the hydrothermal fluids. Subsequently, the fluids reacted with gouge materials to form clay minerals. Fracturing and alteration could have repeatedly taken place in the gouge zone by elevated fluid pressures generated from the reduction of pore volume due to the formation of clay minerals and precipitation of other materials. XRD analysis revealed that the most common clay minerals of the gouge zones are illite and smectite with minor zeolite and kaolinite. Most of illites are composed of 1Md polytype, indicating the products of hydrothermal alteration. The major activities of the Dongnae fault can be divided into two periods based upon K-Ar age data of the fault gouges : 51.4∼57.5Ma and 40.3∼43.6Ma. Judging from the enviromental condition of clay mineral formation, it is inferred that the hydrothermal alteration of older period occured at higher temperature than that of younger period.

• Fire Science and Engineering
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• v.27 no.5
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• pp.19-25
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• 2013

The fire took place in the synthetic heat transfer fluid boiler. This study uses simulation to investigate the first, second and third passes and the temperature in the fire burner. The boiler's internal fluid is more or less unsteady due to the out of order inverter. As the operation continues, the flame's flow and speed are unsteady. The synthetic heat transfer fluid leak spouted about 120 kg/min in the form of vapor in the early period of the fire. The flame extended to the second and third passes. The highest temperature of the second and third pass is $1059^{\circ}C$ and $1007^{\circ}C$, respectively. The simulation shows that the temperature is $767^{\circ}C$ in the low part of the third pass. The synthetic heat transfer fluid spouted through the cracked part of the fire box in the first pass and accumulated on the turn table. The temperature rises to $183^{\circ}C$ in the low part of the burner. Therefore, it is expected that the temperature of the interior of the fire box is above $1200^{\circ}C$. The temperature of the burner rises to a maximum level several times in a short period. On account of that, several explosions occur in the fire burner.

• Journal of Korean Neurosurgical Society
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• v.29 no.4
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• pp.471-476
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• 2000

Objective : p16/INK4a, a kind of tumor suppressor genes, encodes a specific inhibitor of the cyclin D-dependent kinases CDK4 and CDK6. This prevents the association of CDK4 with cyclin D1, and subsequently inhibits phosphorylation of retinoblastoma tumor suppressor protein(pRb), thus preventing exit from the G1 phase. According to previous reports, over 50% of glioma tissue and 80% of glioma cell lines have been demonstrated inactivation of p16/INK4a gene. The purpose of this study was to determine whether recombinant adenovirus-p16 virus is a suitable candidate for gene replacement therapy in cases of glioma. Methods : Three human glioma cell lines(U251MG, U87MG and U373MG) that express mutant p16 protein were used. Replication-deficient adenovirus was utilized as an expression vector to transfer exogenous p16 cDNA into the cells ; control cells were infected with the Ad-${\beta}$-gal expressing ${\beta}$-galactosidase. To monitor gene transfer and the expression of exogenous genes, we used Western Blotting analysis. Flow cytometry studies of cellular DNA content were performed to determine the cell cycle phenotype of the glioma cells before and after treatment. Results : We showed here that restoration of p16/INK4a expression in p16 negative U87MG, U251MG and partially deleted U373MG by Ad-CMV-p16 induced growth suppression in vitro. Flow cytometric study revealed that Ad-CMV-p16 infected U87MG cells were arrested during the G0-G1 phase of the cell cycle. Expression of p16 transferred by Ad-CMV-p16 in glioma cells was highly efficient and maintained for more than seven days. Conclusions : Our results suggest that Ad-CMV-p16 gene therapy strategy is potentially useful and warrants further clinical investigation for the treatment of gliomas.

• Tuberculosis and Respiratory Diseases
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• v.53 no.5
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• pp.485-496
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• 2002

Background : Nonsteroidal anti-inflammatory drugs (NSAIDs) are useful in the chemoprevention of colon cancers. Continuous NSAID use results in a 40% to 50% reduction in the relative risk of colorectal cancer. The precise mechanism by which NSAIDs prevent and/or cause the regression of colorectal tumors is not known. Some investigators have reported that certain NSAIDs induce apoptosis and alter the expression of the cell cycle regulatory genes in some carcinoma cells when administered at a relatively high concentration. However, the possibility of NSAIDs application as chemopreventive agents in lung cancers remains to be elucidated. To address this question, the human lung cancer cell line NCI-H1299 was used to investigate whether or not NSAIDs might induce the apoptotic death of NCI-H1299 cells. Methods : A viability test was carried out using a MTT assay. Apoptosis was measured by flow cytometric analysis and unclear staining(DAPI). The talytic activity of the caspase family was measured by the fluirigenic cleavage of biosubstrates. To define the mechanical basis of apoptosis, western blot was performed to analyze the expression of the death substrates(PARP and ICAD). Results : NaSaL significantly decreased the viability of the NCI-H1299 cells, which was revealed as apoptosis characterized by an increase in the $subG_0/G_1$ population and unclear fragmentation. The catalytic activity of caspase-3 protease began to increase after 24 Hr and reached a peak 30 Hr after treatment with 10 mM NaSaL. In contrast, caspase-6, 8, and 9 proteases did not have a significantly altered enzymatic activity. Consistent with activation of caspase-3 protease, NaSaL induced the cleavage of the protease biosubstrate. Conclusion : NaSaL induces the apoptotic death of NCI-H1299 human lung cancer cells via the activation of caspase-3 protease.

• Cartoon and Animation Studies
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• s.40
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• pp.33-53
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• 2015

The movement of characters is one of the crucial elements to deliver their emotion flowing inside. Though it is the same movement, it may appear or be expressed differently according to the character's personality or emotion or the particular situation. The purpose of this study is to analyze not only the movement found superficially in an animation but also a character's internal emotion and attitude with Laban's movement analysis system, particularly effort, one of its analysis categories, and examine how effectively Laban's movement analysis often employed at the circles of dance can analyze movement in an animation. is about a monster that constantly makes efforts to realize its dream to be a scarer. Functional movement forms the most part, but expressive movement to show how a character thinks or feels also appears harmoniously. Characters' externally shown movement can express their internal emotion properly sometimes, but they also often move expressing their feelings in moderation. Therefore, this study analyzes the movement of characters found in the four scenes of with LMA's effort. According to the findings, at the scene where Michael enters the door leading to the human world following the scarer, the emotional state of Michael envious of the scarer is expressed with the Vision Drive giving the strong feel of dreaming. At the scene of the second game to choose the best scare team, it shows us the Spell Drive with its careful and light movement having clear intention to survive at the game. At the scene where there is a party held for the teams that have survived, it shows the Passion Drive of being eagerly expressing happy and delightful feelings without considering what is around. At the scene where Michael and Sullivan are pursued by people, the Action Drive was used to express movement that was heavy and strong and was getting faster gradually by focusing the feelings of the characters in haste into one place.

• Tuberculosis and Respiratory Diseases
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• v.44 no.1
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• pp.44-51
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• 1997

Background : The changes of the composition in the T-lymphocyte are important as an immunological abnormality in the pathogenesis of tuberculosis. Previously, the second type of TCR dimer(${\gamma}{\delta}$ T lymphocyte) that did not express CD4 or CD8 molecules was found. In other reports the presence of this type of lymphocytes was increased in the initial stage of tuberculous infections. Method : To determine whether there are some differences in the T-lymphocyte subsets in the peripheral blood or pleural effusion between pleural tuberculosis and other pleurisy. Thirty patients with pleural effusion among the forty-nine patients were examined T-lymphocyte subset analysis(CD4+T-cell,CD8+ T-cell,${\gamma}{\delta}$ T-lymphocytes) with anti- Leu4, anti-Leu3a, anti-Lea2a, anti HLA-DR and anti-TCR-${\gamma}{\delta}$-1(Becton & Dickinson Co.). Results : The average age of the patients was 50 years old(17-81year). There were 33 males and 16 female patients. Patiensts with tuberculosis are 30cases(tuberculous pleurisy 15), lung cancer 12cases(malignant effusion 9) and pneumonia 7cases(parapneumonic effusion 6cases) In T lymphocyte subsets of pleural effusion, helper T lymphocyte(54.6 + 13.8 %) of tuberculous pleurisy was higher than that(36.2 + 25.3 %) of non-tuberculous pleurisy(p=0.04). The peripheral blood ${\gamma}{\delta}$ T-lymphocytes in tuberculousis was insignificantly higher than non-tuberculous patients(p= 0.24). The peripheral blood ${\gamma}{\delta}$ T-lymphocytes and pleural ${\gamma}{\delta}$ T-Iymphocytes in tuberculous pleurisy was insignificantly higher than in non-tuberculous pleurisy(p= 0.16, p= 0.12). Conclusion : The percentage of -${\gamma}{\delta}$ T lymphocytes among the total T-lymphocytes is not significantly increased in the peripheral blood or pleural effusion of the pleural tuberculosis. ${\gamma}{\delta}$ T lymphocytes is less useful as a diagnostic method of pleural tuberculosis.

• Proceedings of the Technology Innovation Conference
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• 1996.12a
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• pp.265-295
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• 1996

This paper investigates empirically the relationship between various business portfolio properties (particularly technological properties) and chaebol′s performance using data on the 50 largest chaebols in Korea. In addition to the traditional indexes to measure diversification such as entropy index we calculated inter-industry technological similarity using R&D expenditure data by industry and 1990 Input-output Table in Korea, and obtained chaebol-level technological relatedness and internal transaction proportion from chaebols′business profile, inter-industry technological similarity and 1990 input-output table. We applied factor analysis on 13 business portfolio property indexes and showed that they could be grouped into 3 dimensions, diversification scope, inter-business relatedness and degree of vertical integration. In this paper, using 50 largest chaebols′financial data (1989-1994), we analyzed empirically the effect of business portfolio properties on ROS (Return On Sales) which is conventional index for firm performance and on TFP(Total Factor Productivity) growth which is a pure measure of firm performance. To utilize the advantage of panel data, FEM(Fixed Effect Model) and REM(Random Effect Model) were used. The empirical result shows that the entropy index as a measurement of inter-business relatedness is not significant but technological relatedness index is significant. OLS estimates on pooled data were considerably different from FEM or REM estimates on panel data. By introducing interaction effect among the three variables for business portfolio properties, we obtained three findings. First, only VI (Vertical integration) has a significant positive correlation with ROS. Second, when using TFP growth as an dependent variable, both TR(Technological Relatedness) and f[ are significant and positively related to the deepened variable. Third, the interaction term between TR and VI is significant and negatively affects TFP growth, meaning that TR and VI are substitutes. These results suggest strategic directions on restructuring business portfolio. As VI is increased, chaebols will get more profit. A higher level of either TR or W will increase TFP growth rate. but increase in both TR and VI will have a negative effect on TFP growth. To summarize, certain business portfolio properties such as VI and TR can be considered "resources" themselves since they can affect profit rate and productivity growth. VI and TR have a synergy effect of change in profit rate and productivity growth. VI increases ROS and productivity growth, while TR increases productivity growth representing a technological synergy effect.