• 한국주거학회논문집
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• 제21권5호
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• pp.93-101
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• 2010

The purpose of the study is to investigate the behaviors for ventilation to control indoor air quality and characteristics of the maintenance for ventilation equipments by multi-family housing residents. This study was conducted by the survey in the area of Seoul and Kyungki-do. The results of the study are as follows: the majority of respondents conduct ventilation once a day, below 20 minutes with opening some windows of the inside of the house. The time for ventilation is generally between 9-11 am. and 5-7 pm. Most of the wives are responsible for ventilation activities. In addition, so far building materials and furniture are not seriously considered as the source of indoor air pollution by the respondents. Their satisfaction for indoor air before and after ventilation is perceived as just the level of average. As the mechanical ventilation equipments such as a hood and an exhaust fan, half of the respondents are using them frequently. However, the ventilation equipments are not maintained well. Specially maintenance and checks for exhaust fans are hardly conducted. In conclusion, the frequency of ventilation is very limited and residents show passive attitudes about ventilation and maintenance of ventilation equipments. Therefore, for the actualization of healthy housing, educational programs and guidelines on the way of ventilation targeting the residents should be set up and a certain organization has to check periodically the performance of the ventilation equipments of each house in the multi-family housing complex.

• 골판지포장물류
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• 제7권32호
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• pp.149-156
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• 2000

• 산업공학
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• 제7권2호
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• pp.71-74
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• 1994

With the increasing competitions and globalization of markets, quality has become rather crucial. Because of the significance of the quality, ISO 9000 quality standards has been used in Korea companies. It is difficult to understand ISO 9000 series since the expressions used in the series are not specific, but comprehensive. It is even more difficult to implement the quality system. This paper describes the problems found during the implementation and maintenance of the ISO 9000 standards in companies.

• 원예과학기술지
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• 제30권4호
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• pp.400-408
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• 2012

Effects of initial controlled atmosphere (CA) treatment on quality maintenance of 'Fuji' apples were assessed and compared with 1-methylcyclopropene (1-MCP) treatment and continuous CA storage. Apples were harvested twice at different maturity, treated with 1 ${\mu}L{\cdot}L^{-1}$ 1-MCP and then stored for 8 months at $0^{\circ}C$ under 3 conditions: air, CA for the first month followed by air (initial CA), and continuous CA (full CA). CA storage was performed with 1.5 kPa $O_2$ and < 1.0 kPa ($N_2$ balance). Following long-term storage, export simulation, refrigerated shipment and local distribution, were performed by holding apples at $0^{\circ}C$ for 2 weeks and on the shelf at $20^{\circ}C$ for 7 days. Both the application of 1-MCP and CA storage reduced ethylene production and respiration rates. Initial CA storage was also effective on reducing the metabolism although the effects were not as noticeable as full CA. Full CA storage with or without 1-MCP treatment maintained titratable acidity, flesh firmness, and sensory quality at the acceptable to excellent level even after the export simulation following 8-month storage regardless of harvest maturity. In contrast, effects of initial CA storage were limited to the maintenance of firmness and texture in early-harvested apples. Overall results indicated that harvest maturity is the critical factor for export fruit quality after long-term storage when separate treatment of initial CA storage or 1-MCP treatment is applied as a postharvest program.

• 한국병원경영학회지
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• 제22권4호
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• pp.74-86
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• 2017

Purposes: This study was performed to understand the recognition about accreditation motives, support within the hospital and accreditation survey process for the hospitals that participated in the accreditation program and to find out whether these factors are related to hospital management performances, so that the study can suggest plans for activation and development of the accreditation program. Methodology: This study was performed targeting 98 hospitals answered th the survey among 189 acute care hospitals that acquired accreditation from December 2010 to February 2014. For data analysis, frequency analysis, ${\chi}^2$-test, reliability analysis, ANOVA, Kruskal-Wallis H test and multiple regression analysis with SPSS 21.0 were used. Findings: The hospitals that had staff in charge of patient safety had bigger hospital culture change than those that didn't have(p<.05). In addition, the hospital culture change was bigger as internal motives were bigger, and as CEO's will was bigger(p<.05). Meanwhile, as maintenance rate of internal management after accreditation was higher, and as CEO's will was bigger, process improvement level was higher(p<.05). The quality improvement and patient satisfaction level were higher as CEO's will was bigger, and as suitability of survey process was recognized to be high(p<.05). As a result of analyzing the factors that affect hospital management performances with hospital culture change, process improvement and quality improvement combined, as internal management maintenance rate was higher, as CEO's will was bigger, and as suitability of survey process was higher, performances were higher(p<.05). Practical Implications: Hospitals need to reinforce internal motives to improve internal competences such as the whole system maintenance opportunity and staff training. In addition, the will of hospital director is most important, and if there is hospital director's interest in quality improvement and improvement intention definitely, employees voluntarily participate in and cooperate with the accreditation program, so that prompt medical service provision and high quality of medical services can be guaranteed, leading to hospitals' management performances.

• 산업경영시스템학회지
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• 제43권4호
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• pp.161-167
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• 2020

In the process of cutting large aircraft parts, the tool may be abnormally worn or damaged due to various factors such as mechanical vibration, disturbances such as chips, and physical properties of the workpiece, which may result in deterioration of the surface quality of the workpiece. Because workpieces used for large aircrafts parts are expensive and require strict processing quality, a maintenance plan is required to minimize the deterioration of the workpiece quality that can be caused by unexpected abnormalities of the tool and take maintenance measures at an earlier stage that does not adversely affect the machining. In this paper, we propose a method to indirectly monitor the tool condition that can affect the machining quality of large aircraft parts through real-time monitoring of the current signal applied to the spindle motor during machining by comparing whether the monitored current shows an abnormal pattern during actual machining by using this as a reference pattern. First, 30 types of tools are used for machining large aircraft parts, and three tools with relatively frequent breakages among these tools were selected as monitoring targets by reflecting the opinions of processing experts in the field. Second, when creating the CNC machining program, the M code, which is a CNC auxiliary function, is inserted at the starting and ending positions of the tool to be monitored using the editing tool, so that monitoring start and end times can be notified. Third, the monitoring program was run with the M code signal notified from the CNC controller by using the DAQ (Data Acquisition) device, and the machine learning algorithms for detecting abnormality of the current signal received in real time could be used to determine whether there was an abnormality. Fourth, through the implementation of the prototype system, the feasibility of the method proposed in this paper was shown and verified through an actual example.

• 산업경영시스템학회지
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• 제46권4호
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• pp.133-141
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• 2023

Approximately 40,000 elevators are installed every year in Korea, and they are used as a convenient means of transportation in daily life. However, the continuous increase in elevators has a social problem of increased safety accidents behind the functional aspect of convenience. There is an emerging need to induce preemptive and active elevator safety management by elevator management entities by strengthening the management of poorly managed elevators. Therefore, this study examines domestic research cases related to the evaluation items of the elevator safety quality rating system conducted in previous studies, and develops a statistical model that can examine the effect of elevator maintenance quality as a result of the safety management of the elevator management entity. We review two types: odds ratio analysis and logistic regression analysis models.

• 한국조경학회지
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• 제33권5호통권112호
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• pp.83-93
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• 2005

Research was initiated to investigate turf performance under USGA soil system. USGA system 45 centimeters deep was built with rootzone layer, intermediate layer, and drainage layer. Six turfgrass entries were comprised of 3 blends and 3 mixtures from cool-season grasses (CSG). Turfgrass color and quality ratings were best in spring and fall, especially early May to early July and late August to early November. Kentucky bluegrass (KB) consistently produced the greatest performance, while perennial ryegrass (PR) the poorest. Intermediate turf performance between KB and PR was observed with tall fescue (TF). Among CSG mixtures it increased with KB but decreased with PR. There were considerable variations in summer turf Performance. No summer drought injury was found in KB and TF. However, PR showed poor performance through summer as compared with others. Among mixtures, it decreased with PR. It was suggested that PR mix in less than $20\%$ in the mixtures to have an acceptable quality in summer. Cultural intensity also affected it. With lowering mowing height, KB of rhizomatous-type in growth habit kept good quality, while PR and TF with bunch-type in growth habit poor quality. Mowing quality was greatly different among CSG. KB produced clean-cut surface, but PR unclean one. If had an intermediate mowing quality between KB and PR. A great difference in green color retention was observed among CSG. The longest CSG was PR that kept green for 339 days, while the shortest one TF for 267 days. KB continued to keep green for 290 days. The mixtures kept green in color for 292 to 315 days, depending on turfgrass mixing intensity. The greater the PR in content, the longer the green color duration. These results demonstrate that KB was the best and PR the worst among CSG grown in USGA system under a domestic climate, in regards of turf quality, color, mowing quality, summer turf performance and green color duration. KB and TF are most adequate for high-maintenance and low-maintenance area, respectively. In case of mixtures for high-quality turf, it was desirable to use KB-based mixture with PR of below $20\%$ in seeding rate.

• Journal of the Korean Data and Information Science Society
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• 제20권6호
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• pp.999-1007
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• 2009

본 논문에서는 무료수리보증이 종료된 이후의 최적의 주기적 예방보전정책을 고려한다. 이를 위해서 Wu와 Clements-Croome (2005) 그리고 Jung (2006b)이 제안한 확률적 보전효과를 갖는 두 종류의 예방보전모형을 가정하고자 한다. 이 때, 시스템이 가동되는 동안에 사용자가 지불해야 할 비용이 주어져 있을 때, 단위시간당 기대비용을 유도한다. 그리고 이렇게 구해진 단위시간당 기대비용을 최소화하는 최적의 예방보전 횟수와 예방보전 주기를 결정한다. 끝으로 수치적 예를 통해서 제안된 예방보전정책을 자세히 설명한다.

• 품질경영학회지
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• 제40권4호
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• pp.599-614
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• 2012

Purpose: We measure service quality based on service process, and examine relationships among product quality, product and service loyalty. Methods: We develop a construct to evaluate process based service quality. We collect data from customers of auto maintenance centers to measure perceived product quality, service and product quality. We test relationships between constructs using structural equation model and regression analysis. Results: Relationships among perceived-product quality, service quality, service loyalty, and product loyalty are all significant. Conclusion: Perceived-product quality has a indirect impact through service quality and loyalty in addition to a direct impact on product loyalty.