• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.6
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• pp.643-656
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• 2019

The development of hot social networking services, including the Internet, has transformed rental car services into IT-based car-sharing services. The car-sharing service is a service that allows people to rent cars online without having to face-to-face. It has become the preffered service among young people who are accustomed to drinking and eating alone. Users can use their smartphones to book their types of cars and hours of rent, and then go to a nearby designated parking lot to use their reserved cars. You can open a designated car door with a smart phone and drive. It is a very convenient service to pay for the distance you drive. However, the car-sharing service already in use in business has the following problems: underage who do not have a driver's license may drive a car borrowed by an acquaintance, the status of a license registered at the time of join membership with a car-sharing company may change to a suspension or cancellation of a license while renting and driving, or even a drunk person may rent a car and drive. In this paper, the method to solve these problems has been studied and proposed. The proposed method is to reduce the cost of investment by a car-sharing service provider and to minimize user inconvenience. And, it was compared and analyzed with the existing method. For the method to be used efficiently, the active operation of the car-sharing company and the government's policies will have to be supported.

• 대한공업교육학회지
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• v.36 no.1
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• pp.1-22
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• 2011

The purpose of this study was to develop and apply activity-centered STEM education program of electricity and electronics technology are in middle schools. The program was developed on the emphasis of problem solving in real world in relation to knowledge, attitude, and skill of Science, Technology, Engineering, and Mathematics. Basically the activity-centered STEM education program was developed through three steps of preparation, development and improvement. In the preparation stage the fellowing was included: (1) need analysis of student, educator, society (2) selection of integration type (3) analyzing subject matter of electricity, electronics area (4) establishing criteria for selecting activity tasks. In the development stage the fellowing was conducted: (1) selection of activity tasks (2) setting up educational goals (3) analyzing activity and clarifing the detailed activity (4) selecting program content, (5) organization of instructional content (6) statement of instructional objectives (7) structuring STEM education program In the improvement stage the fellowing was consisted of: (1) verification of validity by experts (2) execution of pilot test and field test by students and correction of program. The results of the applied the Activity-Based STEM Education Program to 'Afterschool' activities of S middle school were as follow: First, student' satisfaction level was high. Second, student' achievement in the cognitive domain, and affective domain was positive change. Third, student' problem solving ability was positive effect.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.4
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• pp.209-214
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• 1974

The utilization dietary protein in young rainbow trout was investigated when feeded with the diets of controlled levels of casein and lipids for 12 days. The composition of the diet is shown in Table 1. Body weight gain was in proportion to the protein content in diet up to $40\%$, ana the maximum was obtained with $40.4\%$ of crude protein (Fig. 1, Table 2). On the other hand, the accumulated protein in body also showed almost maximum value around 40n of protein level in the diet and: the change of accumulated protein showed a little with more-protein level(Fig. 3, Table 9). The protein accumulation rate (protein accumulated/protein consumed) showed its highest value at about $40\%$ of protein level, while the protein utilization value (protein accumulation rate x protein content of diet) attained its highest value at $54.8\%$ of protein level (Table 3). With the above results it is observed that the requirement of dietary protein for young rainbow trout is about $40\%$ of protein in the diet when casein is used as the sole protein source. In protein efficiency ratio (PER) the lower protein level in the diet, the higher PER yields and the more the quantity of protein increases, the more PER decreases and its relation could be figured out as an equation of y=4.91-0.034x (Fig.4), Nose measured PER utilizing the diet which result of this, it is reported that PER rate of casein dropped within the extent of $25\%$ protein in diet. The reason why such a different PER rate appeared at the low protein level is revealed as the carbohydrate is low but the lipid high in capacity of utililzing nutrients for rainbow trout. The relation between the protein content of diet and the conversion factor, feed efficiency were determined and the results are shown in Fig. 2.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.140-149
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• 2017

Recently, it has become necessary to consider climate change when managing multi-purpose river functions. However, in terms of domestic rivers, the management of national and local rivers is separated and the river information cannot be integratedly handled. Especially, it is not sufficient to collect and update information by recycling reports for design and construction. In addition, the basic information of the rivers is dependent on the GIS-based RIMGIS system, but the reliability of the information is deteriorating due to the construction of spatial information using the river basement planning results. The purpose of this study is to investigate the current status of the information system with regard to the maintenance and operation of the river facilities. Through the verification of actual cases, the optimal solution was suggested from the point of view of practical information. As a result, we constructed an information system for the reliable maintenance of river facilities and examined the integrated information management plan. The results of this study can be used to improve the existing information and technical and institutional procedures for the integrated maintenance and operation of river facilities. It will be helpful to introduce the BIM as well as solve to the information gap with other fields through the establishment of an information framework to improve the information construction of river areas.

• International Journal of Highway Engineering
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• v.10 no.4
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• pp.9-18
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• 2008

Curling is caused by the difference in the temperature and humidity by the depth of the slab in Jointed Plain Concrete Pavement. Slab curvature shape and size change due to curling exert a profound influence on the internal stress and roughness of the pavement, affecting structural and functional performance of the pavement. Direct measurement of the slab curvature entails many problems. Many measuring instruments have to be installed at the early-stage of the pavement construction, and the behavior of the slab curvature needs to be measured accurately from the early-stage. Moreover, the cost and technical difficulty are very formidable to measure the slab curvature. This study develops a measurement method for slab curvature in jointed concrete pavement at any given time by applying Power Spectrum Density Analysis and Inverse Fast Fourier Transformation to the profile data, that can be easily obtained at the construction field site. The effectiveness of this developed method is verified by measuring the profile data of the test road of jointed concrete pavement at an inland central expressway by the hour and by examining the result of extracting the slab curvature shape from this profile data. Additionally, the profile data of CRCP(Continuously Reinforced Concrete Pavement) sections on the same expressway were obtained and analyzed at the same time. The validity of the method developed for the slab curvature shape extraction is verified by comparing the result from the analysis of the profile data of CRCP sections with that from the analysis of the prof1Ie data of jointed concrete pavement sections.

• Journal of Korean Society of Transportation
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• v.21 no.1
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• pp.41-49
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• 2003

Marine traffic management could be defined as the implementation of managerial technical measures to improve vessel traffic safety. The managerial elements of vessel traffic management for ports and harbours or narrow channels include the total amount of traffic control, the vessel traffic separation scheme, speed restriction, traffic control by signals, the navigation information service and so forth. This research aims to quantify how much the traffic separation schemes(TSS) contribute to the alleviation effect of ship handling difficulty and to propose a design standard when the individual management measure is applied in an actual waterway. Traffic separation schemes have now been established in most of the major routes and congested waters of the world, and the number of collisions and groundings have often been dramatically reduced. In this part, the relationship between the alleviation of ship handling difficulty and the reduction of encounter figures among ships is quantitatively clarified by applying the ES model. As results of simulation analysis, it is recognized that a traffic separation system is most effective in the case of narrow width and heavy traffic volume. The centre buoy installation reduces about 1/4 of the alleviation of ship handling difficulty, TSS establishment 1/3, and design change to one-way traffic from two-way traffic reduces 1/2.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.29 no.5
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• pp.247-259
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• 2017

Numerical model with LPT (Lagrangian Particle Tracking) module was used to understand the variation of residence time in the outer sea of the Sihwa lake result operating from the Sihwa tidal power plant. Numerical model was composed in order to investigate the spatial distribution characteristics, the average residence time in each area was calculated by dividing the outer sea area of Sihwa lake into 4 areas. The average residence time of the areas appeared to be increase as it entered the areas located in the inner bay (13 days) from the area located in most outer sea (3 days) both before and during operation. Variation of average residence time by areas were increased in the area that was located in the most outer sea of during operation compared to before operation, and decreased in the other area. Artificial discharges from tidal power plant induces particle traps in the formation of vortex in the area located in the most outer seas, entrainment in the remaining areas, which affects variation in residence time. In other words, the jet flow generated during drainage and the change in the residence time due to the vortex and entrainment action indicate the increase horizontal mixing of water in the outer sea and in the inner bay.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.2
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• pp.371-384
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• 2010

This research investigates the historical changes of the educational system for the clothing departments at vocational high schools. According to the growth of the fashion industry, employment potential in the clothing departments of the vocational high schools, numerical changes in the educational statistics, and curriculums were investigated by papers, reports, and statistic data. The statistic data were derived from the 'Center Educational Statistics and Information', 'School Information' (Hak-gyo Alimi), 'Korean Statistical Information Services' and internet home pages of vocational high schools. Technical service workers that graduate from clothing departments and vocational high schools have limited competitiveness in a thriving fashion industry field. Highly developed fashion industries require more professional workers in fashion design, fashion marketing, and fashion materials. Compared to 1994, when 35 classes were conducted in 5 vocational high schools, 69 classes are now conducted at 15 schools. They have over 2,000 students and produce over 600 graduates. However, 222 credits of the $1^{st}$ curriculum in 1958 went down to 82 credits in the 2007 revised curriculum to complete the credits of clothing departments. The 15 courses of the 1st curriculum fell to 5 courses in the 2007 revised curriculum on the number of major subjects. It is a fundamental problem that major courses in clothing education have been excessively reduced despite the demand for of highly specialized workers in the fashion industry. In the view of operating conditions of those schools, there were several problems such as the wide gaps in the curriculum, limited equipment, the supply of teachers, and counseling on the choice of college or a career. In conclusion, the following measures are required: 1) the increase of complement credits in major subjects and renovation of curriculum, 2) national substantial support to change the social circumstance concerning vocational education and occupational consciousness, 3) operation of credit approving systems in universities and colleges for students that have completed the same courses at vocational high schools, 4) designing realistic programs for vocational education and cooperation systems with corporate enterprises.

• Explosives and Blasting
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• v.27 no.2
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• pp.33-41
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• 2009

Specific charge, also called powder factor, is defined as the total explosive mass in a blast divided with the total volume or weight of rock to be fragmented. It is a well-known fact that change in explosive consumption per ton or per cubic meter of rock is always a good indication of changed rock conditions. In mining, it is common to use explosive consumption per ton of ore as a measure of the blastability for rock. On the contrary, in civil engineering, it is common to use explosive consumption per cubic meter of rock. In this paper, we adopt the definition of the civil engineering because we are mainly concerned with tunnel blasting. Up to now, although various methods for tunnel blast design have been proposed, there are so many cases in which the proposed methods do not work well. These may be caused by the differences in rock conditions between countries or regions, and can give a serious technical difficulty to a contractor. But if we know the specific charge for a given rock, then the blast design can become much more easier. In this respect, we suggest an algorithm for tunnel blast design that can exactly produce the predetermined specific charge as a result of the design. The algorithm is based on the concept of assigning different fixation factors to various parts of tunnel section, and may be used in combination with the known methods of tunnel blast design.

• Journal of the Korean Society for Library and Information Science
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• v.41 no.4
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• pp.93-111
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• 2007

The Internet is now an integral part of the everyday lives of a majority of people. Web users are becoming increasingly skeptical of the information and services offered online. They are demanding web sites that offer credible information. This study focused on what features of web sites affect the perception of web credibility. For this purpose, I took the responses from 648 people and extracted 49 factors that affect web credibility. I placed the individual factors - the specific questions asked in the survey - into one of four categories expertise. trustworthiness, ads and other and calculated the means for each of the 49 factors. As a result, 29 out of 49 factors increase the Perceptions of credibility and 20 factors decrease the web credibility. Sites with frequently update. the credentials of authors, strict content guides, search capabilities, clear connections to the real world fared good in credibility. Technical problems such as broken links, site sown, or typographical errors were rated the most negative on this scale On the other end of the scale, a domain name that ends in' .org' or' .or.kr' caused little change in perception of credibility.