• Applied Chemistry for Engineering
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• v.9 no.2
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• pp.165-171
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• 1998

The $Y_1Ba_2Cu_3O_{7-x}$(123) superconductor powders were prepared by pyrophoric synthesis method(PSM) using $Y_2O_3$(99.9%), $BaCO_3$(99.9%), and CuO(99.9%) powders. The phase formation and reaction kinetics of 123 superconductor manufactured with powders prepared in various pHs of pyrophoric synthetic solution have been studied through the experiments at various heat treatment temperatures and times. Inductively coupled plasma(ICP) spectroscopy and scanning electron microscopy(SEM) measurements were performed to examine the composition and morphology of the sample. X-ray diffraction(XRD) analysis was done to determine phase formation and conversion ratio of Y-Ba-Cu-O systems. The 123 powder prepared at pH 7(${\pm}0.3$) yields the best result in terms of purity, homogeneity, and reactivity. The activation energies(${\Delta}E_a$) of 123 phase formation were found to be 191 kJ/mol and 230kJ/mol in solid state reaction method and pyrophoric synthesis method, respectively.

• Journal of Korean Theatre Studies Association
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• no.52
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• pp.359-397
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• 2014

This paper describes dramatherapy with a bulmina nervosa patient. She was in her early 20s and has been under the various psychotherapies for cure of deep depression since 2005. We had 24 sessions and 3 persons - the patient, the therapist, and the assist-therapist- participated in dramatherapy. I found there's a big collision between her important roles in the course of initial interview and diagnosis. Those roles are 'a good daughter of mom' and 'an independent adult'. Therefore I defined her bulmina nervosa as 'an symbolic behavior repeats compulsively the failure of separation from her mother.' And I set the general goals, the separation from her mother, the awareness and expression of negative emotions, and the diminuation of overeating and vomiting. To attain these object, we had many different dramatic experiences in dramatherapy. We made a self-portrait, the mask of bulmina nervosa, family sculpture, figure work, the past I and the present I, psychodramatic scene and several stories. In order to objective assessment, I used behavioral observation and 6PSM(6 Pieces Story Making) analysis. First of all the most noticeable change was a rapid decrease in over-eating and vomiting. Before the dramatherapy she had overeaten 30 times per week. At the closure it has fallen off to 1 time per week. Another behavioral changes were shift of outward appearance, not going church, working for living, and having a date with only one. She made 3 stories on 1th session, 13th session, and 23th session. And I comparatively analysed those stories with both qualitative and quantitative method. For qualitative analysis, I classified 5 structures according to the substantial similrarity. On protagonist structure, there's no difference. Three protagonists are dead things. The type of task structure is changed from an escape, a traveling, to metamorphosis. The type of obstruction structure is changed from the protagonist to an outside object. The type of closure structure is changed from an exaggerated happy ending, sad ending to probable happy ending. To quantitify the aspects of transformation, I developed an assesment tool using likert scale. It is composed of 4 sub-categories-reality testing, imagination, ego-strength, optimism problem-solving. In reality testing category, a shift of score was 9-11-15, imagination 2-5-5, ego strength 3-2-2, optimism 6-3-7, and total score 20-21-29. This change of score reflects the growth of problem solving capacity. Viewed in this light, dramatherapy with this girl was successful on the whole. The thing had significant effect on it was psycho-dynamic approach focused on separation from her mother and defence mechanism to avoid negative emotion. And assessment method used in this case will be full of suggestions to researches to come.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.6
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• pp.59-64
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• 2010

Building a firebreak against surface forest fire is a typical indirect suppression method that stops spread of flame by removing surface fuel, such as fallen leaves and bushes. In the sense of fire dynamic, building a firebreak is to set a section which will block thermal energy from igniting on virgin fuel. This study suggests and evaluates a calculation method for width of firebreak against surface fire for variant wind and slope conditions by applying the Point Source Model (PSM) to fallen leaves of Pinus densiflora. Width of firebreak was measured based on the distance the threshold radiant heat igniting Pinus densiflora fallen leaves at the heat flux of $4.9\;kW/m^2$ reaches. As a result, at the wind velocity of 0~5 m/s and on the slope of $0{\sim}50^{\circ}$, the appropriate width of a firebreak was 0.35~0.65 m for the mean flame height and 0.75~1.05 m for the maximum flame height. Accordingly, considering the factor of safety, the most appropriate width of a firebreak is 1.05 m based on the maximum flame height. Additional comparative analyses through experiments and field surveys are deemed necessary to determine appropriate widths of firebreak for different types of surface fuel.

• Journal of Korea Technology Innovation Society
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• v.15 no.3
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• pp.649-674
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• 2012

The purpose of this study is to investigate the effects of public R&D subsidies on private R&D. We have analyzed rationales for the public R&D subsidy from different perspectives. On the basis of literature review, a two step research model is constructed: participation phase (when firms benefit from public subsidies) and decision phase (when firms make decision on additional R&D investments). Using propensity score matching(PSM) method, we compare the potential outcome of the treated group to a matched controlled group of non-subsidized firms. The data used in this paper was collected from various sources. The Korean Innovation Survey 2008(manufacturing sector) is a main source of data. Financial data such as revenue, asset and capital stock, and number of employees were supplemented from the Nice Information Service KIS Value database. The R&D survey, conducted by MEST(Ministry of Education, Science and Technology) each year, was also used for the R&D expenditures of the manufacturing firms. This study comes up with the following empirical results. First, a firm's innovation capability, financial constraints, and sector appear to influence the selection of firms who were benefited from government's financial supports for R&D. Second, empirical results show that public R&D funding complements private investment on average and appear to have perpetual effects on the following year. Finally, sectoral difference in the effect of public subsidies on firms' R&D investment was confirmed. In addition, SMEs show more positive effects than large firms.

• Korean Journal of Social Welfare
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• v.67 no.4
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• pp.279-299
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• 2015

This study examines the impact of Long-Term Care Insurance(LTCI) on family caregivers(especially focused on female household members) labor supply in South Korea. When public care and informal care are substitutes, LTCI will change allocation of time of family caregivers to spend more time to paid work. The impact of LTCI on labor supply depends on each country's institutional level of public care services. If public care can not substitute for informal care, labor supply of family caregivers will not rise significantly. The conclusions of vigorous empirical study from western countries' are incompatible and problem of endogeneity in terms of methodology has been raised consistently. The dataset of this study are used the third and ninth waves of Korea Welfare Panel. As a result, the introduction of LTCI had no effect on labor supply of household members. Robust findings suggest the positive effects of caregiving on labor market outcomes in simple comparison t-test, but not in fixed-effect regression. Compared with western countries, South Korea's public care services can be interpreted as a supplement to only part that remained at the level does not substitute informal care. These findings may suggest that if LTCI become much more prevalent in the future, senior citizens and family members will be able to choose the LTCI arrangement that best suits their needs.

• Membrane Journal
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• v.32 no.6
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• pp.367-382
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• 2022

Numerous metal-organic frameworks (MOFs) produced by periodic combinations of organic ligands and metal ions or metal-oxo clusters have led the way for the creation of energy-efficient membrane-based separations that may serve as viable replacements for traditional thermal counterparts. Although tremendous progress has been made over the past decade in the synthesis of polycrystalline MOF membranes, only a small number of MOFs have been exploited in the relevant research. Intercrystalline defects, or nonselective diffusion routes in polycrystalline membranes, are likely the reason behind the delay. Postsynthetic modifications (PSMs) are newly emerging strategies for providing polycrystalline MOF membrane diversity by leveraging advanced membranes as a platform and improving their separation capabilities via physical and/or chemical treatments; therefore, neither designing and developing MOFs nor tailoring membrane synthesis techniques for focused MOFs is necessary. In this minireview, seven subclasses of PSM techniques that have recently been adapted to polycrystalline MOF membranes are outlined, along with obstacles and future directions.

• Journal of the Korean Society of Safety
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• v.21 no.4 s.76
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• pp.127-133
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• 2006

The major purpose of this paper to identify safety climate practices, and to find the affecting variables that influence to the difference in the level of safety climate between plants and employees. And this paper attempted to find the interventions for improving safety climate in the chemical plants. The questionnaires were developed from literature review, especially made by HSE(Health and Safety Executive) in the UK and distributed to managers and workers. The frequency analysis was applied for identifying the level of safety climate. The affecting variables(plant size, accident occurrence, accident experience, injury experience and severity, and length of employment) are tested through analysis of variance(ANOVA). The results of frequency analysis showed that both managers and workers recorded generally high level of safety climate, and the major underlying problems are inadequate H&S procedures/rules, pressure for production, and rule breaking. According to the outcomes of ANOVA, the variable 'length of employment' is the only variable which makes the level of safety climate different. From the survey of safety climate practice, this study finds the level of safety climate and three major underlying problems in safety climate factors of the responded plants, and presents two interventions for improving safety performance. Despite of these outcomes, the applied factors are remained questionable for reflecting as the best ones for identifying safety climate in the chemical industry. In addition, the bias caused by self-report exist in the reliability of the response, and the equivalent size of respondents.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.1 s.343
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• pp.65-70
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• 2006

An image sensor has limited dynamic range while the human eye has logarithmic response over wide range of light intensity. Although the sensor gain can be set high to identify details in darker area on the image, this results in saturation in brighter area. The gamma correction is essential to fit the human eye response. However, the digital gamma correction degrades image quality especially for darker area on the image due to the limited ADC resolution and the dynamic range. This Paper proposes a CMOS image sensor (CIS) with a nonlinear analog-to-digital converter (AU) which performs analog gamma correction. The CIS with the proposed nonlinear analog-to-digital conversion scheme was fabricated with a $0.35{\mu}m$ CMOS process. The analog gamma correction using the proposed nonlinear ADC CIS provides the 2.2dB peak-signal-to-noise-ratio(PSM) improved image qualify than conventional digital gamma correction. The PSNR of the image obtain from the digital gamma correction is 25.6dB while it is 27.8dB for analog gamma correction. The PSNR improvement over digital gamma correction is about $28.8\%$.

• Fire Science and Engineering
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• v.30 no.5
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• pp.1-8
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• 2016

Safety management in hazardous areas with potentially explosive gas atmospheres (here in after referred to as hazardous areas) in large scale facilities dealing with combustible or flammable materials at home and abroad is very important (significant) for the coexistence of the company and local society based on business continuity management (BCM) and reliance. For the safety management in hazardous areas, two systems are mainly used: (1) the control system for the prevention of combustible or flammable substances and (2) the explosion proof system for the elimination of ignition sources when flammable gases are leaked to inhibit the transition to fire or explosion accidents. While technology and regulations on explosion proof facilities or devices for electrical ignition sources are well developed and defined, those for thermal ignition sources need to be more developed and established. In this study, the internal combustion engine in hazardous areas was investigated to determine the risk of ignition. For this purpose, document searches were conducted on the relevant international standards and accidents cases and risk analysis reports. In addition, this study assessed the application cases of the diesel engine's safety equipment, such as spark arresters regarding the site of process safety management (PSM) system in central Korea. To practically apply these results to the hydrocarbon industry, the safety management method for explosion prevention in hazardous areas was provided by risk identification for ignition sources of internal combustion engines, such as diesel engines.

• Journal of Korea Technology Innovation Society
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• v.21 no.2
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• pp.767-787
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• 2018

Technology-driven innovation and job-creation has each been the subject of much scholarly attention, but have largely been considered separately rather than in conjunction with each other. While the previous literature on economics pinpointed the macro effects on industry-level, this study explores the micro-level comparisons on innovation sources over the employment and financial performances. The PSM (propensity-score matching) analysis presents that firms, involved in an inward technology, tend to have higher employees with dominant technology capabilities than in-house R&D firms. The in-house R&D firms, on the contrary, have superior financial performances, suggesting that external technology commercialized firms suffer from low transformative efficiency. The mediation test analysis corroborates that the external technology-driven innovation induces more human resources in internalizing the exogenous technology. The positive relationship between R&D innovation and employment allow verification of the government's intervention in the promotion of technology commercialization in public sector. On the other hand, it also signals that the policy needs to enhance the recipient firms' commercializing capacity rather than a 'one-hit' transaction.