• 대한화학회지
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• 제7권2호
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• pp.122-127
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• 1963

Pyrolysis fo polyethylene and polypropylene has been studied in order to clarify the mechanism of chain scission and effect of oxygen on degradation. Rate of weight decrease was measured under nitrogen and air atmosphere at constant temperature for the samples of high density polyethylene, low density polyethylene and isotactic polypropylene, and then gaseous hydrocarbons produced from pyrolysis were analysed by gas chromatography. Although there is little substantial difference between composition of hydrocarbon gases from pyrolysis of high density polyethylene and low density polyethylene except some difference in quantity of total gas produced, gas composition from polypropylene pyrolysis differs from that of polyethylene pyrolysis. Gases from pyrolysis under air contain much more unsaturated hydrocarbons than those from pyrolysis under inert gas.

• 대한안전경영과학회지
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• 제14권4호
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• pp.1-12
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• 2012

This study investigated the comprehension of the occupational safety policy direction by job characteristics of the safety managers at 211 workplace selected under the Occupational Safety and Health Act. As for the characteristics of the subjects' firms, there was difference in their perception on the occupational safety policy direction by their region, type, scale, and the existence of labor union. Regarding the job characteristics of the subjects, there was difference in the comprehension of the occupational safety policy direction by their age, experience and department. This study suggests that the government policy as well as the awareness about safety by management and safety managers need to be changed by analyzing the comprehension of occupational safety policy direction by the job characteristics of corporate occupational safety managers.

• 산업기술연구
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• 제19권
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• pp.343-350
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• 1999

The separation of humic acid by ultrafiltration was most influenced by pressure difference. when pressure difference increased from latm to 3atm, permeate flux increased from 40% to 60% but rejection rate reduced from 97% to 91% because of adsorption of molecules of humic acid at membrane surface. Since physical adsorption was more dominant than chemical adsorption, adsorption of membrane surface was reduced 50% when slow rate increased at same conditions.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제4권2호
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• pp.135-142
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• 2000

We consider a multigrid algorithm for higher order finite difference scheme for the Poisson problem on rectangular domain. Several smoothers including Jacobi, Red-black Gauss-Seidel are tested and compared. Since higher order scheme gives much more accurate result then 5-point scheme, one may use small number of levels with higher order scheme and thus the overall cost is reduced quite a lot. The numerical experiment compares the two cases.

• 산업융합연구
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• 제11권1호
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• pp.31-44
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• 2013

This study was to identify the relationships among the autonomy, job stress, and job performance of nurses. For general characteristics, there was no difference was a difference in the job stress of the subjects in accordance with their ages and clinical nursing career. In conclusion, in order to enhance nursing specialty by offering qualitative nursing, To amerliorate job performance, it is necessary to improve the autonomy of nurses and to manage their job stress properly.

• 대한안전경영과학회지
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• 제12권2호
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• pp.161-166
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• 2010

EPC Information Services (EPCIS) is an EPCglobal standard designed to enable EPC-related data sharing within and across supply chain. The EPCIS standard defines standard interfaces to enable EPC-related data to be captured and subsequently to be queried using a set of service operations and an associated data model. There are two kinds of EPCIS data: event data and master data. Event data is created in the process of carrying out business processes. Traceability of goods across supply chain is based on event data. Therefore, each company must have an event data. This study compared he difference between MS-SQL(DRDBMS) and ALTIBASE(MMDBMS) for data storage. We compared the difference between two database management in many respects such as insert time and select time. We come to a conclusion that ALTIBASE is more efficient than MS-SQL.

• 산업경영시스템학회지
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• 제41권2호
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• pp.153-158
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• 2018

At the Bank of Korea, capital stock statistics were created by the PIM (perpetual inventory method) with fixed capital formation data. Asset classifications also included 2 categories in residential buildings, 4 non-residential buildings, 14 constructions, 9 transportation equipment, 28 machinery, and 2 intangible fixed assets. It is the Korean government accounting system which is developed much with the field of the national accounts including the valuation, but until 2008 it was consistent with single-entry bookkeeping. Many countries, including Korea, were single-entry bookkeeping, not double-entry bookkeeping which can be aggregated by government accounting standard account. There was no distinction in journaling between revenue and capital expenditure when it was consistent with single-entry bookkeeping. For example, we would like to appropriately divide the past budget accounts and the settlement accounts data that have been spent on dredging into capital expenditure and revenue expenditure. It, then, tries to add the capital expenditure calculated to FCF (fixed capital formation), because revenue expenditure is cost for maintenance etc. This could be a new direction, especially, in the estimation of capital stock by the perpetual inventory method for infrastructure (SOC, social overhead capital). It should also be noted that there are differences not only between capital and income expenditure but also by other factors. How long will this difference be covered by the difference between the 'new series' and 'old series' methodologies? In addition, there is no large difference between two series by the major asset classification level. If this is treated as a round-off error, this is a problem.

• 품질경영학회지
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• 제52권2호
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• pp.287-301
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• 2024

Purpose: This paper aims to verify the difference in production resilience between local clusters and regions without clusters before and after a major crisis. Furthermore, this paper aims to identify the clusters' quality factors that impact clusters' shock vulnerability and resilience. Methods: Utilizing open-source data from the US Cluster Mapping platform, this paper compares regions with industrial clusters to those without using the Differences-in-Differences (DID) estimator. It considers the regions with industrial clusters as a treatment group and others as the control group, comparing the period before and after the pandemic. Additionally, the paper examines which cluster factors make a difference in economic resilience during the crisis using Regression Discontinuity Design (RDD). Results: The study finds that regions with industrial clusters show higher production resilience compared to regions without clusters. Moreover, the number of establishments, annual payrolls, and employment can have a positive impact on resilience during the pandemic shock. Conclusion: Though clusters could be vulnerable during the global crisis, industrial clusters can contribute to regional economic development and production resilience in the long-term aspect. Thus, it is required to construct a high-quality local cluster and support it during the economic crisis in the long-term aspect.

• 산업경영시스템학회지
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• 제39권4호
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• pp.117-124
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• 2016

Stress is resistance to stimuli to destroy a balance of mind and body in order to maintain an original steady state : A type of response and avoidance. Mild stress, which happens in tension, has a positive effect to improve concentration, but most of stress is likely to be a main factor to damage health. This is because it causes physical ailments and psychological diseases (e.g., depression, anger, frustration, loneliness, and anxiety). The purpose of this study is to analyze the difference between two groups, daytime and night university students, on ego-state, stressors, and stress coping types to improve their academic achievement by reducing their stress. There were 266 university students, who participated in a survey from November 30, 2015 until September 30, 2016. The study employed three measuring instruments : Ego-gram, stressor scale, and stress coping type scale. All the collected data were analyzed through regression analysis and t-test. The results of the regression analysis showed no significant differences in ego-state, stressors, and stress coping types between two groups. However, the results of t-test showed significant difference between the two groups : In terms of ego-state, a CP (Critical Parent) average of the night university students was significantly higher than the daytime university students'. Also, there is a significant difference in employment, future issues, and economic issues : the daytime university students considered employment and future issues more serious, while the night university students had more mental burdens of economic issues. When it comes to coping stress types, there was no significant difference between the two groups.

• Environmental Analysis Health and Toxicology
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• 제20권2호
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• pp.97-108
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• 2005

This study is to estimate differences, relationships and related factors of environmental risk perception and perceived benefit among residents and workers. A self-administered questionnaire survey using a structured instrument was carried out to residents and workers in industrial area during April, 2002. Total number of participants were 657 including 329 residents and 328 workers. Participants assessed environmental risk perception, self- assessed knowledge, trust in authorities and perceived benefit associated with 10 products manufactured in industrial area. There were difference in environmental risk perception, knowledge and trust in authorities and perceived benefit among residents and workers. Especially, trust in authorities and perceived benefit were statistically significant difference among residents and workers. Inverse relationships between environmental risk perception and perceived benefit have been observed for different products. In other words, the greater the perceived benefit, the lower the perceived risk, and vice versa. Factors mostly associated with participant's characteristics of environmental risk perception were age. marriage status (workers), education level (workers). There was statistically significant difference. Perceived benefit was statistically significant difference with sex, marriage status, residence duration, education level (workers). Related factors of environmental risk perception among residents and workers were age, trust in authorities. And factors affecting the perceived benefit were sex, age, education level (workers), and trust in authorities (workers). According to the results, people having high trust in the authorities perceived less risks than people having low in the authorities. To improve the communication of risk information, further study focus on assessment of experts, government and stakeholder in industrial area. Methodologies of this study can be used as the basis for investigating the structure of public perception of environmental products risks and benefit, designing a public information and risk communication program, and developing policy actions to improve acceptance.