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        검색결과 12

        1.
        2024.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Biodiesel is a traditional energy field that can replace low-quality marine fuels for ships and various studies have been conducted. Since the 2000s, Korea has introduced a mandatory supply system of biodiesel for domestic vehicle diesel, gradually raising the blending ratio from 0.5% to 3.5%, and is expected to raise the mandatory blending ratio to about 8.0% by 2030. Therefore, in this study attempted to blend high-quality samples that meet the biodiesel quality standards manufactured by domestic companies with MGO in ratios ranging from 0 to 60%. We utilized a 1-ton combustion chamber to compare and analyze the exhaust gas emissions characteristics. As a result, in the BD60 condition, which represents the maximum range in this study, the O2 increased by approximately 1.5%p, and CO2 tended to decrease by 1.1%p. NOx decreased by approximately 18.2%p from 34.1 ppm to 27.9 ppm. In the case of SOx, a very low concentration of 0.08 ppm was detected under the BD0 condition, and it was undetectable under all other conditions containing biodiesel. This suggests that MGO itself has excellent low-sulfur oil quality and can implement zero SOx through biodiesel mixing. Furthermore the combustion efficiency decreased by approximately 1.91%, from 72% to 70.2%, and the exhaust gas temperature also decreased by about 4.5%p. However despite the lower calorific value of biodiesel compared to MGO, it demonstrated relatively close thermal output per unit content. This indicates sufficient potential for biodiesel to serve as a viable alternative fuel for ships in the future.
        4,000원
        2.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study intends to development of a lap scale 1-ton standard combustion chamber. The manufactured standard combustion chamber analyzes pilot combustion tests and emission standard data of MGO fuel oil. The actual capacity of the standard combustion chamber is about 900L, total weight of 265kg. As a result of the pilot combustion test, the O2 was about 8.01% and the CO2 was about 9.34%. In the case of NOx, it was about 33.50 ppm, and SOx (SO2) was about 0.76ppm. The combustion efficiency was about 72.41%, the exhaust gas temperature was 366.7℃, and the combustion chamber internal temperature was about 448.0℃.
        4,000원
        3.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study intends to use the possibility of an eco-friendly alternative fuel to be applied to ships as a sample manufacturing method for ship MGO and bioethanol mixed fuel oil as basic evidence. The components of the manufactured mixed fuel oil were analyzed using the ISO-8217 standard testing method. As a result of analysis showed that in the lower calorific value decreased to 43030J/g at BE0 fuel and 37010J/g at BE30 fuel. The high calorific value decreased to 46.065MJ/kg at BE0 fuel and 39.460MJ/kg at BE30 fuel. The density decreased to 840.8kg/m3 at BE0 fuel and 837.0kg/m3 at BE30 fuel. In the case of flash point it was 67.5℃ when BE0, and decreased to less than 40.0℃ when BE10 to BE30. Finally the Kinematic Viscosity was 3.011mm2/s at BE0 and decreased to 2.502mm2/s at BE30.
        4,000원
        4.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The use of printing inks containing organic solvents by the master, offset and screen printing process implies the release of volatile organic compounds (VOCs) to the work environment. In this study, the volatile content of inks was evaluated by using a thermogravimetric analyzer (TGA), in which the solvent is evaporated. And, to identify the the characterization of VOCs emissions from printing inks, air samples were collected in a thermal extractor (TE) and analyzed by thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS). Weight loss curves suggest that there are two main stages, such as dry fastening and chemical curing. As the result, the first stage of mass loss (below 100oC) was due to VOC evaporation. At this stage, master and offset inks are slightly stable thermally up to 100oC, but screen inks weight loss increases distinctly beyond 25oC. The volatile content is higher in screen inks than in the master and offset inks. The results of the mass-specific TVOC emission rate of the master, offset, and screen inks were 6.3 μg/(g·h), 8.4 μg/(g·h), and 212.2 μg/(g·h), respectively. Then the TVOC emission rate of the screen inks was 25~33 times higher than that of the master and offset inks. The main species were 1-Ethyl-2-pyrrolidinone, 1,2,4-Trimethylbenzene, 1,2,3-Trimethylbenzene, 1,2,4,5-Tetramethylbenzene, 1-Methoxy-2- propanol, Decane, Undecane, and Nonane.
        4,600원
        5.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The concern of fine particle (PM2.5) management of outdoor environments has been increasing due to its exposure and related health effects in Korea. As a result, PM2.5 standard in atmosphere environment was regulated in 2015. On the other hand, indoor PM2.5 standard has been required because most people spent their times in indoor environments. In this study, we measured the PM2.5 and PM10 concentrations both indoor and outdoor environments of public-use facilities such as underground stations, underground shopping centers, and nurseries for 24 hour with filter-weighing method in Seoul and Daegu. Measurement duration was from March to April in 2014 during the Asian dust period. At all measurements, indoor to outdoor (I/O) concentration ratios exceeded 1 except 1 day nursery in Daegu in spite of Asian dust period. The ratios of PM2.5 to PM10 concentrations ranged from 0.63 to 0.75 in indoor environments, and from 0.63 to 0.82 in outdoor, indicating that PM2.5 should be carefully managed in indoor environments as well as outdoor atmosphere.
        4,000원
        6.
        2014.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to verify the relationships among innovative behavior, turnover intention, and job security. An additional purpose was to examine partial mediating effects on psychological ownership. The baseline of analyzing those relationships in this study is that the role of psychological ownership will be a mediator between job security and turnover intention as well as innovative behavior in the organization. To accomplish these purposes, a model was built among job security as predictor variable, the psychological ownership as mediating variable and turnover intention, and innovative behavior as criteria variables based on the studies conducted in the various areas. The 248 questionnaires surveyed from the area of DaeGu and Kyungbuk were used in the statistical analyses. The detail statistical techniques are such as descriptive analysis, reliability analysis, factor analysis, correlation analysis, and multi regression analysis. The results of the study show that job security had positively significant effect on turnover intention and innovative behavior. In addition, only the psychological ownership of organization-level thinking have partial mediating effects between job security and innovative behavior also job security and turnover intention. The results may indicate that the psychological ownership of organization-level thinking be a key factor to alleviate the turnover intention of employees and to encourage the innovative behavior during their works for the small-medium size companies showing the unstable job security.
        4,900원
        7.
        2012.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Many companies have endeavored to build a quality cost management system in order to be more productive business organization. This study shows the detail procedures of constructing a quality cost management system which is believed to be appropriate for their business system. That is, the method to calculate the quality cost and the linking logic between the quality improvement and its financial impact are explained based on a particular industry case. In this sense, the changes of business performance measures such as market share, customer satisfaction, etc. were analyzed in the longitudinal perspective for the consecutive 4 years (2003~2006). As the quantitative results of this study, the improvement activities based on the quality cost management system resulted in the 32% reduction of quality cost and the 121% increase of business profit, compared 2005 with 2006. In the qualitative perspective, the successive practice of quality cost reduction and the job information sharing in business unit were obtained by providing the best practices and bench-marking cases. Finally, the customer satisfaction has increased so that the customer-friendly management system has been accomplished. With these efforts, the 3.4% increase of the market share and the 3% increase of the customer satisfaction were obtained in 2005. As the future study, the current study can be extended to the concept of COPQ (cost of poor quality) which focuses on the hidden quality cost of the whole business activities. Such extension of analysis will help us understand the wider role of a quality cost management system in the business.
        4,300원
        8.
        2008.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
          Manufacturing Execution System (MES) is a system that companies can use to measure and control critical production activities. This paper shows case study of implementation of MES (Manufacturing Execution System) and its methodology in a medium sized pr
        4,000원
        9.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
          Motorola developed the framework of six sigma in 1987. In these days, many companies adapt this powerful tool. In 1996, six sigma was introduced to the Korean companies as a management innovation tool. This study shows case study of ‘Champion Project’ w
        4,300원
        10.
        2007.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to explore the applicability of AHP(Analytic Hierarchy Process) to select more productive projects among various proposed projects in a particular company. To achieve this research objective, the characteristics of project evaluation and selection are first reviewed with respect to when, where, and how the decision is made. Then the theoretical basis of the AHP is briefly reviewed along with its mathematical underpinnings to construct the framework of project evaluation and selection. To be more specific, the evaluation and selection criteria were reorganized in the AHP-based framework to make the process of project evaluation and selection more productive. Project evaluation and selection is one of the most important activities for the most companies to be more advantageous in the market. Despite the importance of decision making process of project selection, not many of how to choose the best project were suggested as the reliable project selection methods in the industries. It may be because it involves various activities related to conflict resolution among different evaluation criteria, high uncertainties of market, and the unclear tradeoff among various project objectives. Furthermore, the decision, once made at this point, tends to be irrevocable until the whole process turns out to be a complete success or failure. As the result, the AHP method showed better financial performance rather than the traditional method in a case study.
        5,500원
        11.
        2003.10 구독 인증기관 무료, 개인회원 유료
        This study aims to examine the relationships between total quality management(TQM) practices and operational performance perceived by employees who are in different organization types, R&D organization and Non-R&D organization in manufacturing companies. Operational performance is defined as the degree of operation efficiency in the perspective of quality, delivery, and cost. Our study showed that the degree of TQM practice has significant difference in organization type. In case of R&D organization, the categories of customer focus and process management were the strongest significant predictors of operational performance. Therefore, the optimal TQM practices for R&D organization can be obtained in consideration of customer focus and process management.
        3,000원
        12.
        2017.11 KCI 등재 서비스 종료(열람 제한)
        Side scanning sonar (SSS) provides valuable information for robot navigation. However using the side scanning sonar images in the navigation was not fully studied. In this paper, we use range data, and side scanning sonar images from UnderWater Simulator (UWSim) and propose measurement models in a feature based simultaneous localization and mapping (SLAM) framework. The range data is obtained by echosounder and sidescanning sonar images from side scan sonar module for UWSim. For the feature, we used the A-KAZE feature for the SSS image matching and adjusting the relative robot pose by SSS bundle adjustment (BA) with Ceres solver. We use BA for the loop closure constraint of pose-graph SLAM. We used the Incremental Smoothing and Mapping (iSAM) to optimize the graph. The optimized trajectory was compared against the dead reckoning (DR).