• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.6
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• pp.663-670
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• 2014

The Pyeongtaek port is expected lack of waiting anchorage due to increase of incoming ships whit increasing of trading volume in the near future. In case of an anchorage facility's structural alternations and expansion, it should be considered comprehensively how it affects other anchorage facilities. In addition, the volume of ship traffic to relevant area should be estimated accurately and then the facility's scale is calculated. In this paper, researchers calculated cargo per unit ship with the throughput for every ship and predicted the number of ships which had entered Pyeongtaek port. As a result, the port's ability to be docked was predicted to be not enough in 2030. It will exceed the number of ships able to cast anchor at specific two parts simultaneously 12.6 and 1.6 respectively consequently, the necessity to expand the ports was suggested. Hence, the best expansion plan was examined with analysis of marine transportation environment at each ports and the improvements suggested are anchoring ships at Ippado anchorage is 19.7 and the one at Janganseo anchorage is 12.6.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.4
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• pp.507-514
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• 2022

Jinhae Bay is used as a major typhoon shelter in the southeastern region of Korea. However, when a typhoon strikes, the Jinhae Bay is facing the possibility of marine accidents caused by dragging anchors and the increased number of ships. This paper suggested ways to safely and efficiently manage the port of Jinhae Bay when a typhoon strikes from Vessel traffic service operators in the sea, derived relative importance by conducting an Analytic Hierarchy Process assessment to ship operators, and suggested safety measures reflecting manager and user opinions. In order to select safety measures factors for the AHP survey, VTS operators analyzed the evaluation of measures when a typhoon strikes in Jinhae Bay. As a result of conducting a survey based on the selected safety measure factors, it was found that ship operators consider the safety of ships more than twice as important as efficient management, and comprehensively consider them in the order of management of evacuated ships, management of anchorage area, management of evacuation information, preparation regulations and guidelines, improvement of system equipment, education, publicity, and notification activities. Through the measures and relative importance identified in this paper, it is believed that Jinhae Bay can serve as the basis for safely and efficiently managing typhoon shelters.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.25 no.2
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• pp.75-81
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• 1989

In this paper, the authors describe on the field experiment of the newly designed actual stow net, standing on the result of the model experiment to examine the performance of the conventional net and the newly designed net, presented in two previous reports of this series. Concurrently the additional experiment to find out the possibility of changing of operating system from the side to the stern was carried out. 1. Fundamental shape of the experimented net was 20 times aslarge asthe newly designed model net. Performance of the net was detected by using two ultrasonic echo sounders: one was set downward at the top-most spreader of the shearing device to detect the opening height of the device from the sea bed, and the other sidewise at the starboard top-most spreader to detect the top-most opening width of the devices. Opening height of the newly designed net showed about 3m smaller than the conventional net at slow current of 0.6m/sec and less but it overcome 1m at speedy current of 0.8m/sec and more. Opening width of the newly designed net was 1.4 times as large as that of the conventional net, ant the front projection area of the newly designed net mouth was estimated as 1.3~1.6 times as large as that of the conventional net. 2. The experiment on the stern operating system was tightly limited by the structure of the ship employed in the experiment, which was a stern trawler of 2275 GT. The ship confronted by the wind with main anchor, while the net was put over the stern slipway and the hauling line of shearing device was operated through the top rollers of gallows. The experiment was very suggestive in the view point to mechanize the operating system, and so to decrease the man power except the following question. The of bow-stern line of ship, and that of net is much different.

• Journal of Intelligence and Information Systems
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• v.18 no.4
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• pp.97-116
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• 2012

Conceptual modeling is an important step for successful system development. It helps system designers and business practitioners share the same view on domain knowledge. If the work is successful, a result of conceptual modeling can be beneficial in increasing productivity and reducing failures. However, the value of conceptual modeling is unlikely to be evaluated uniformly because we are lack of agreement on how to elicit concepts and how to represent those with conceptual modeling constructs. Especially, designing relationships between components, also known as part-whole relationships, have been regarded as complicated work. The recent study, "Representing Part-Whole Relations in Conceptual Modeling : An Empirical Evaluation" (Shanks et al., 2008), published in MIS Quarterly, can be regarded as one of positive efforts. Not only the study is one of few attempts of trying to clarify how to select modeling alternatives in part-whole design, but also it shows results based on an empirical experiment. Shanks et al. argue that there are two modeling alternatives to represent part-whole relationships : an implicit representation and an explicit one. By conducting an experiment, they insist that the explicit representation increases the value of a conceptual model. Moreover, Shanks et al. justify their findings by citing the BWW ontology. Recently, the study from Shanks et al. faces criticism. Allen and March (2012) argue that Shanks et al.'s experiment is lack of validity and reliability since the experimental setting suffers from error-prone and self-defensive design. They point out that the experiment is intentionally fabricated to support the idea, as such that using concrete UML concepts results in positive results in understanding models. Additionally, Allen and March add that the experiment failed to consider boundary conditions; thus reducing credibility. Shanks and Weber (2012) contradict flatly the argument suggested by Allen and March (2012). To defend, they posit the BWW ontology is righteously applied in supporting the research. Moreover, the experiment, they insist, can be fairly acceptable. Therefore, Shanks and Weber argue that Allen and March distort the true value of Shanks et al. by pointing out minor limitations. In this study, we try to investigate the dispute around Shanks et al. in order to answer to the following question : "What is the proper value of the study conducted by Shanks et al.?" More profoundly, we question whether or not using the BWW ontology can be the only viable option of exploring better conceptual modeling methods and procedures. To understand key issues around the dispute, first we reviewed previous studies relating to the BWW ontology. We critically reviewed both of Shanks and Weber and Allen and March. With those findings, we further discuss theories on part-whole (or part-of) relationships that are rarely treated in the dispute. As a result, we found three additional evidences that are not sufficiently covered by the dispute. The main focus of the dispute is on the errors of experimental methods: Shanks et al. did not use Bunge's Ontology properly; the refutation of a paradigm shift is lack of concrete, logical rationale; the conceptualization on part-whole relations should be reformed. Conclusively, Allen and March indicate properly issues that weaken the value of Shanks et al. In general, their criticism is reasonable; however, they do not provide sufficient answers how to anchor future studies on part-whole relationships. We argue that the use of the BWW ontology should be rigorously evaluated by its original philosophical rationales surrounding part-whole existence. Moreover, conceptual modeling on the part-whole phenomena should be investigated with more plentiful lens of alternative theories. The criticism on Shanks et al. should not be regarded as a contradiction on evaluating modeling methods of alternative part-whole representations. To the contrary, it should be viewed as a call for research on usable and useful approaches to increase value of conceptual modeling.

• Journal of The Korean Association For Science Education
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• v.18 no.4
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• pp.601-615
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• 1998

Establishing and evaluating science education policies and revising and monitoring the effectiveness of science curriculum should be based upon the results of systematic and scientific research studies. Advanced nations have already been administering and developing national level science assessments for these purposes. The science assessments administered in Korea have been reported having many limitations and problems, and not succeeded in providing data for science education policy making and curriculum reform. The major purpose of the study is developing national level science knowledge assessment system in order to identify longitudinal trends of elementary and secondary school students science knowledge achievements. The research team consisted of science education experts and teachers from various school levels, decided the directions and major elements of national level science knowledge assessment with the consultation of educational evaluation experts. Item developing ability of the researchers was improved by seminars? and workshops on national assessment in advanced nations and developing skills of writing science items. Nearly 500 items were developed and revised. Pilot test was administered with 958 students at various school levels. 380 items were selected and tested with 8766 students, and the characteristics were analyzed in terms of item response theory. The target populations for national level science knowledge assessment are 5th-grade of elementary school, 2nd-grade of middle school, 1st and 2nd-grade of high school students. The proper period for the assessment is February every year. Multi-stage clustered sampling method is desirable and rotated forms are recommendable for the test format. Bridge items should be introduced to compare the results of multiple tests, and various grades. Anchor items should also be used for longitudinal interpretations of the results. The items for elementary school require low to medium abilities, for middle school and first grade of high school require medium to high abilities and for 2nd-grade of high school high abilities. The discrimination ability of the items developed is high.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.24 no.2
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• pp.55-64
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• 1988

Stow nets have widely been used in the western sea of Korea from the olden age. The original structure of a stow net is a large square-sectional bag net made of 4 netting panels, and the front fringes of top and bottom panels are connected to the top and bottom beams respectively. Wire ropes, which is originated from the holding anchor are gradually forked and biforked, and finally 4 pieces of wire rope (biforked pendants) are jointed to each beam. Much convenience caused by long and heavy beams were problemed, then some studies have been carried out to improve the net since 1930's. The most effective improvement were achieved in 1980 by Mr. Han and his colleagues. The key point of improvement was that the beams were removed and the belt shaped shearing device made by canvas was attached to the side panels, the head rope and ground rope to the front fringe of top and bottom panel, and biforked pendants are joined to the shearing device. Even though this is the epoch-making improvement of a stow net, the further study should be required to find out more effective method. The authors carried out a model experiment on the stow net to determine the vertical and horizontal opening of a net mouth, and also examine the front, top and side-view configuration of the net. The model net was constructed depending on the Similarity Law of Fishing Gear in 1/10 and 1/20 scale and set against to the current at shallow and speedy flowing channel. The vertical and horizontal openings were determined by using scaled bamboo poles, and the configuration was observed by using specially prepared observation platform and underwater observation glass, and also photographed by using specially prepared underwater photographic equipment. The results obtained can be summarized as follows: 1. The opening height and width of the shearing device varied in accordance with the relative length of the biforked pendants. Considering the height and width of shearing device in 6 cases of the arrangement system of biforked pendants, the best result was obtained in the case that the 2nd, 3rd and 4th pendents from the bottom-most was 5%, 9% and 4% longer than that. 2. On the top-view configuration the excessive deformation of head rope and ground rope were observed. In the actual net, 54m long head rope and ground rope were attached to the front fringe of top and bottom panels so that the head rope may be lifted to make the net mouth open highly. But actually the head rope and the ground rope are streamed backward without any lift, and also the netting followed the ropes were deformed until the 2/5 in the whole length of the net. This deformation may be guessed to disturb the entrance of fish school into the net and also caused the net to get caught by obstacles in the sea bed and to be broken largely. 3. Hydrodynamic resistance R of the actual net may be deduced as R(kg)=29.2$\times$103 v1.65. It is also expressed as R(kg)=5.9$\times$d/l$\times$ab v1.65. depending on the formula deduced by Koyama to estimate the resistance of trawl nets, where d/l denote the ratio between diameter of netting twine and length of mesh leg in every part of side panel, a and b, the stretched circumference of the mouth and the stretched length of the net, respectively.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.152-161
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• 2023

In general, large-capacity hydrogen storage vessels, typically in the form of vertical cylindrical vessels, are constructed using steel materials. These vessels are anchored to foundation slabs that are specially designed to suit the environmental conditions. This anchoring method involves pre-installed anchors on top of the concrete foundation slab. However, it's important to note that such a design can result in concentrated stresses at the anchoring points when external forces, such as seismic events, are at play. This may lead to potential structural damage due to anchor and concrete damage. For this reason, in this study, it selected an vertical hydrogen storage vessel based on site observations and created a 3D finite element model. Artificial seismic motions made following the procedures specified in ICC-ES AC 156, as well as domestic recorded earthquakes with a magnitude greater than 5.0, were applied to analyze the structural behavior and performance of the target structures. Conducting experiments on a structure built to actual scale would be ideal, but due to practical constraints, it proved challenging to execute. Therefore, it opted for an analytical approach to assess the safety of the target structure. Regarding the structural response characteristics, the acceleration induced by seismic motion was observed to amplify by approximately ten times compared to the input seismic motions. Additionally, there was a tendency for a decrease in amplification as the response acceleration was transmitted to the point where the centre of gravity is located. For the vulnerable components, specifically the sub-system (support columns and anchorages), the stress levels were found to satisfy the allowable stress criteria. However, the concrete's tensile strength exhibited only about a 5% margin of safety compared to the allowable stress. This indicates the need for mitigation strategies in addressing these concerns. Based on the research findings presented in this paper, it is anticipated that predictable load information for the design of storage vessels required for future shaking table tests will be provided.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.2
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• pp.33-51
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• 2022

This study analyzes newly listed companies on KOSDAQ from 2011 to 2020 for both firms having experience in attracting venture investment before listing (VI) and those without having experience in attracting venture investment (NVI) by examining differences between two groups (VI and NVI) with respect to both the level of listing performance and that of firm performance (growth) after the listing. This paper conducts descriptive statistics, mean difference, and multiple regression analysis. Independent variables for regression models include VC investment, firm age at the time of listing, firm type, firm location, firm size, the age of VC, the level of expertise of VC, and the level of fitness of VC with investment company. Throughout this paper, results suggest that listing performance and post-listed growth are better for VI than NVI. VC investment shows a negative effect on the listing period and a positive effect on the sales growth rate. Also, the amount of VC investment has negative effects on the listing period and positive effects on the market capitalization at the time of IPO and on sales growth among growth indicators. Our evidence also implies a significantly positive effect on growth after listing for firms which belong to R&D specialized industries. In addition, it is statistically significant for several years that the firm age has a positive effect on the market capitalization growth rate. This shows that market seems to put the utmost importance on a long-term stability of management capability. Finally, among the VC characteristics such as the age of VC, the level of expertise of VC, and the level of fitness of VC with investment company, we point out that a higher market capitalization tends to be observed at the time of IPO when the level of expertise of anchor VC is high. Our paper differs from prior research in that we reexamine the venture ecosystem under the outbreak of coronavirus disease 2019 which stimulates the degradation of the business environment. In addition, we introduce more effective variables such as VC investment amount when examining the effect of firm type. It enables us to indirectly evaluate the validity of technology exception policy. Although our findings suggest that related policies such as the technology special listing system or the injection of funds into the venture ecosystem are still helpful, those related systems should be updated in a more timely fashion in order to support growth power of firms due to the rapid technological development. Furthermore, industry specialization is essential to achieve regional development, and the growth of the recovery market is also urgent.

• Journal of Intelligence and Information Systems
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• v.19 no.4
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• pp.39-53
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• 2013

The emergence of the internet technology and SNS has increased the information flow and has changed the way people to communicate from one-way to two-way communication. Users not only consume and share the information, they also can create and share it among their friends across the social network service. It also changes the Social Media behavior to become one of the most important communication tools which also includes Social TV. Social TV is a form which people can watch a TV program and at the same share any information or its content with friends through Social media. Social News is getting popular and also known as a Participatory Social Media. It creates influences on user interest through Internet to represent society issues and creates news credibility based on user's reputation. However, the conventional platforms in news services only focus on the news recommendation domain. Recent development in SNS has changed this landscape to allow user to share and disseminate the news. Conventional platform does not provide any special way for news to be share. Currently, Social News Service only allows user to access the entire news. Nonetheless, they cannot access partial of the contents which related to users interest. For example user only have interested to a partial of the news and share the content, it is still hard for them to do so. In worst cases users might understand the news in different context. To solve this, Social News Service must provide a method to provide additional information. For example, Yovisto known as an academic video searching service provided time dependent metadata from the video. User can search and watch partial of video content according to time dependent metadata. They also can share content with a friend in social media. Yovisto applies a method to divide or synchronize a video based whenever the slides presentation is changed to another page. However, we are not able to employs this method on news video since the news video is not incorporating with any power point slides presentation. Segmentation method is required to separate the news video and to creating time dependent metadata. In this work, In this paper, a time dependent metadata-based framework is proposed to segment news contents and to provide time dependent metadata so that user can use context information to communicate with their friends. The transcript of the news is divided by using the proposed story segmentation method. We provide a tag to represent the entire content of the news. And provide the sub tag to indicate the segmented news which includes the starting time of the news. The time dependent metadata helps user to track the news information. It also allows them to leave a comment on each segment of the news. User also may share the news based on time metadata as segmented news or as a whole. Therefore, it helps the user to understand the shared news. To demonstrate the performance, we evaluate the story segmentation accuracy and also the tag generation. For this purpose, we measured accuracy of the story segmentation through semantic similarity and compared to the benchmark algorithm. Experimental results show that the proposed method outperforms benchmark algorithms in terms of the accuracy of story segmentation. It is important to note that sub tag accuracy is the most important as a part of the proposed framework to share the specific news context with others. To extract a more accurate sub tags, we have created stop word list that is not related to the content of the news such as name of the anchor or reporter. And we applied to framework. We have analyzed the accuracy of tags and sub tags which represent the context of news. From the analysis, it seems that proposed framework is helpful to users for sharing their opinions with context information in Social media and Social news.