• Title/Summary/Keyword: improvement of route performance

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Boarding environment of training ship KAYA for the hull vibration (실습선 가야호의 선체진동에 대한 승선환경)

  • Kim, Min-Son;Shin, Hyeon-Ok;Kim, Min-Seok;Han, Jin-Seok
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.45 no.1
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    • pp.46-55
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    • 2009
  • To compare and evaluate the suitability and comfort levels of the environment on board a stern trawl training ship, KAYA(GT: 1737 tons, Pukyong National University), with the international standardization guide ISO 6954:2000(E), measurements of the hull vibration on accommodation areas and working areas of the training ship from July 8 to July 10, 2008 were completed upon KAYA's linear sea route. The vibrations along the z-axis were measured with the use of a 3-axis vibration level meter, which included a marine vibration card. Results show accelerations of the vibrations on the passenger's accommodation area to be 42.0-115.8(average: 78.0, standard deviation(SD): 21.0) mm/$s^2$, which is largely below the permissible upper limit, but 75 % of the observation points exceeded the permissible lower limit of 71.5 mm/$s^2$, indicating a comfortable environment. The accelerations of the vibration in a frequency of 10-24Hz lowering the visual performance were measured at 2.5-12.0(average: 7.6, SD: 3.1) mm/$s^2$. The crew s accommodation area experienced vibration accelerations of 42.9-82.3(average: 93.1, SD: 53.1) mm/$s^2$, which is generally below the permissible upper limit of 214.0 mm/$s^2$, and 62.5% of the observation points did not exceed the permissible lower limit of 107.0 mm/$s^2$, denoting a level of comfort. The acceleration of the vibration in a frequency of 10-24Hz were 4.7-28.3(average: 12.4, SD: 8.8) mm/$s^2$. On the crew s working area the accelerations were measured at 86.9-153.9(average 119.3, SD 18.0) mm/$s^2$. These values were generally below the permissible upper limit of 286.0 mm/$s^2$ and only 12.5% of the observation points did not exceed the permissible lower limit of 143.0 mm/$s^2$, the level at which a high level of comfort is maintained. The accelerations in frequency of 10-24Hz and 30Hz were 9.1-29.8 (average 13.8, SD= 4.5) mm/$s^2$ and 8.9-13.7 (average 11.8, SD 2.1) mm/$s^2$, respectively. In conclusion the boarding environment of the training ship was good in general although an improvement of the vibration condition partially needed on the crew s accommodation area near the engine room.

Different Perception on Product Attributes of HMR: Focusing on College Students and Consumers (가정간편식의 제품속성에 대한 인식차이: 대학생들과 소비자를 중심으로)

  • Yang, Hoe-Chang;Kim, Jong-Baek;Kim, An-Sik
    • Journal of Distribution Science
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    • v.14 no.2
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    • pp.47-56
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    • 2016
  • Purpose - The purpose of this study is to investigate the difference in the degree of significance and satisfaction perceived by college students and ordinary consumers on the HMR product attributes. Comparison of the difference on HMR product attributes between ordinary consumers and college students who belong to the current and future consumption groups of HMR will provide information for clear marketing strategies and PR on target consumers from the aspects of companies. Also, overall difference on HMR was investigated through IPA(importance-performance analysis) on significance and satisfaction with each product attribute. This result will provide information to food companies that produce or supply HMR products to be supplemented and improved. Finally, IPA was conducted between groups on product attribute to find which difference exists between groups. This result is also expected to provide crucial information to companies as suggested in the first purpose. Research design, data, and methodology - The procedure of analysis is as follows. First, independent sample t-test was conducted on the significance and satisfaction on HMR product attributes. Second, with using IPA, the significance and satisfaction on HMR product attributes of the respondents were checked to investigate marketing strategy direction on overall HRM products. Third, the difference between generations was verified using IPA on the college student and consumer groups. According to this result, the direction of marketing strategy on HRM products was to be proposed to food companies. Results - It was known that consumers consider HMR product attributes statistically and significantly such as nutrient content(nutrition), country of origin, brand, main raw material, packaging, and awareness of manufacturer. They keep after purchase more importantly than college students who considered only volume and price than consumers. In comparison with the difference in satisfaction on HMR product attributes, the college student group was more satisfied than ordinary consumers only in flavor, condition of food additives, and volume. Also, HMR related food companies must maintain taste, cooking method, manufacturing date, expiration date, and safety on current products continuously. Finally, as a result of analysis from the groups, the attributes such as cooking method, manufacturing date, expiration date, and safety were considered significantly with high achievement by the two groups. It was known that college students considered food texture to be important, but consumers considered storage method to be important after purchasing it. Conclusions - There is necessity to differentiate effectiveness of products when releasing HMR products subject to consumers and college students. The result will give great assistance to the improvement of companies, produce or supply HMR products. It will also provide entry strategies on target groups of companies that are planning for entry. The factors that consumers commonly considered not to be significant were brand, package form(appearance), cooking time, and sale(purchase) location, which were found in the comparison with the groups that awareness about manufacturers and storage method after purchase corresponded to college students and that distribution route corresponded to ordinary consumers.

A study on performance comparison of jacket cooling fresh water system for marine diesel engine (선박용 디젤기관의 재킷 냉각청수시스템 성능 비교에 관한 연구)

  • Kim, Duk-Kyung;Lee, Jae-Hyun;Cho, Kwon-Hae
    • Journal of Advanced Marine Engineering and Technology
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    • v.41 no.1
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    • pp.8-14
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    • 2017
  • Due to the financial crisis in 2008, the world economy collapsed leading to an increase in oil prices and a decrease in freight by shipping. To overcome this crisis, major shipping companies ordered larger ships, changed their trading route and improved operating of ships to overcome deficits. In particular, low-speed navigation was much favored by many companies so that it can reduce fuel consumption. However, the long-term operation of high-speed optimized engines in low-speeds has affected the jacket cooling fresh water (J.C.F.W.) system as they fail to maintain the normal operational temperature. The temperature of J.C.F.W. system dropped leading to low temperature corrosion. As a result, when the engine is operating at minimal load the functioning of existing J.C.F.W cooler is decreased and the use of fresh water generator is substantially limited. Therefore, an improvement in the functioning of J.C.F.W. system is necessary. In this paper, in order to review the improvements required for the operation of J.C.F.W. of low-speed operating marine diesel, an experiment was conducted by comparing and analyzing the results of the main engine J.C.F.W. system of a Panamax class bulk carrier 82k and a Cape class bulk carrier 180k by installing and uninstalling the J.C.F.W. Cooler. Thus, this paper proposed an improved design of the J.C.F.W. system that is suitable for the present low-speed operation.

Hydrologically Route-based Green Infra facilities assessment Model: Focus on Bio-retention cells, Infiltration trenches, Porous Pavement System, and Vegetative Swales (수문학적 추적 기반의 GI 시설 평가 모델: 생태저류지, 침투도랑, 투수성포장, 식생수로를 대상으로)

  • Won, Jeongeun;Seo, Jiyu;Choi, Jeonghyeon;Kim, Sangdan
    • Journal of Wetlands Research
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    • v.23 no.1
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    • pp.74-84
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    • 2021
  • Active stormwater management is essential to minimize the impact of urban development and improve the hydrological cycle system. In recent years, the Low Impact Development (LID) technique for urban stormwater management is attracting attention as a reasonable alternative. The Storm Water Management Model (SWMM) is actively used in urban hydrological cycle improvement projects as it provides simulation functions for various GI (Green Infra) facilities through its LID module. However, in order to simulate GI facilities using SWMM, there are many difficulties in setting up complex watersheds and deploying GI facilities. In this study, a model that can evaluate the performance of GI facilities is proposed while implementing the core hydrological process of GI facilities. Since the proposed model operates based on hydrological routing, it can not only reflect the infiltration, storage, and evapotranspiration of GI facilities, but also quantitatively evaluate the effect of improving urban hydrological cycle by GI facilities. The applicability of the proposed model was verified by comparing the results of the proposed model with the results of SWMM. In addition, a discussion of errors occurring in the SWMM's permeable pavement system simulation is included.

Comparative Analysis on Competitiveness between Ports in Northeast Asia Employing Shift-share Analysis and DEA (변이할당기법과 DEA를 활용한 동북아시아 항만간 경쟁력 비교 분석)

  • Lee, Choongbae;Kwon, A Rim
    • Journal of Korea Port Economic Association
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    • v.30 no.4
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    • pp.219-254
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    • 2014
  • Due to the recent development of globalization and supply chain management, growth of international trade has led to increasing cargo volume around the world. Since maritime logistics environments have changed, increased container ship size, improvement of harbor equipment, global port operation and rapid technological development have had an significant effects on shipping and port industry, which is contributing to competitiveness of port. Since a larger volume of port throughputs are generally regarded as an indicator of the more competitive port, inefficient port operation could reduce its competitiveness. On the other hand, high efficient ports could increase their competitive power while increasing cargo volume. This study aims at comparing competitiveness of the ports in the Northeast Asia by investigating changes of container throughputs and evaluating efficiency performance of ports. Shift-Share analysis and Data Envelopment Analysis(DEA) have been conducted with 21 Northeast Asian ports and then separated them into 4 groups for comparative analysis to identify competitive position of each port. The results of this study show that Incheon and Gwangyang port have been decreased container cargo volume, while volume of Busan port would increase by means of active marketing, various route development and incentive policy for the port.

A Study on the Structure Model of Social Welfare Students' Career Preparation Behavior based on Social-cognitive Career Theory (사회인지진로이론에 기초한 사회복지학 전공 대학생의 진로준비행동 구조모형 검증)

  • Yu, Young-Ju;Park, Ji-Sun
    • Journal of Digital Convergence
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    • v.16 no.1
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    • pp.85-92
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    • 2018
  • In this study investigated the factors for the career preparation behaviors of social welfare major students based on Lent et al. (1994)'s Social-cognitive Career Theory so as to provide essential baseline data for establishing proper career support strategies that suit the distinctive nature of social welfare studies. The participants of this study are 132 social welfare major students from three colleges who have completed social welfare field education. This study analyzed the relationship between cognitive factor (outcome expectation), vocational interest factor (major selection satisfaction), goal factor (career decision level), and work performance factor (career preparation behavior). For analysis, SPSS 24.0 and AMOS 24.0 were used. The analysis results are as follows. First, the model's goodness of fit was found to be at a statistically ideal level with CFI=.904, TLI=.887, and RMSEA=.068. Second, the result of analyzing the correlation between the primary variables is as follows: as outcome expectation increased, major selection satisfaction grew, which then increased the career decision level and led to the improvement in career preparation behavior. These results indicate the importance of developing a customized route support program considering the perceived and interesting factors of individual students to improve their career preparation behavior for social welfare majors.