• Progress in Medical Physics
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• v.21 no.3
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• pp.239-245
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• 2010

The purpose of this study is to comprehensively compare and evaluate the characteristics of image quality for digital mammography systems which use a direct and indirect conversion detector. Three key metrics of image quality were evaluated for the direct and indirect conversion detector, the modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE), which describe the resolution, noise, and signal to noise performance, respectively. DQE was calculated by using a edge phantom for MTF determination according to IEC 62220-1-2 regulation. The contrast to noise ratio (CNR) was evaluated according to guidelines offered by the Korean Institute for Accreditation of Medical Image (KIAMI). As a result, the higher MTF and DQE was measured with direct conversion detector compared to indirect conversion detector all over spatial frequency. When the average glandular dose (AGD) was the same, direct conversion detector showed higher CNR value. The direct conversion detector which has higher DQE value all over spatial frequency would provide the potential benefits for both improved image quality and lower patient dose in digital mammography system.

• The Journal of Fisheries Business Administration
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• v.39 no.1
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• pp.87-114
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• 2008

The cultured tuna production which has suddenly expanded at the short time and the demand for it attract attention. Farming mode, distribution transactions, change of the market (domestic and international) and the price trend are reviewed from the Japan's position which is the biggest consuming country. This paper tries to describe the current status of the food system related to the cultured tuna. Japanese government began the development of the tuna culture technology in 1970. It was by the Fisheries Agency's project. Kinki University which is the large scale private university in Japan participated in the project. After that, 32 years have passed. Kinki University established the full farming of the bluefin tuna in August, 2002. On the other hand, in 1974, one Japanese private enterprise began its tuna farming business in Canada. Kinki University gave this company technical cooperation. Also, in the early stages of the 90s, as for the policy of the overseas fishery cooperation foundation, it supported the tuna farming business in Australia. It is very clear to understand that the long-term technological-development has supported the take-off scene of the tuna culture business not only in foreign countries but also in Japan. The total shipment scale of the cultured tuna expanded very much within about 10 recent years. However, the decrease of the wild tuna catch, the reinforcement of the fisheries regulation and the tuna body to dwarf are remarkable now. Under the condition as the mentioned above, Japan's tuna consumption, especially, in the market at the fatty meat of tuna of the cultured tuna is building up firm status. At present, the Mediterranean Sea coastal countries, Australia, Mexico and Japan have the tuna farming sites. Australia farms the southern bluefin tuna. The others do the bluefin tuna. About for 3 years, Japan farms the juvenile of the tuna. The global production areas are as follows. 8 coastal countries of the Mediterranean Sea; 18,000 tons (61 % of the cultured tuna quantity in foreign countries), Mexico; 4,500 ton (15%), Australia; 7,000 tons (24%). In 2003, Japan has 32 managements and 39 offices for tuna farming. In Japan, Kyushu and Okinawa district, the share shows itself as 80 % of the domestic production quantity. Especially, the share of Amami-oshima Island in Kagoshima Prefecture exceeds 60 %. Therefore, this island has the maximum production scale of Japan. The amount of supply of BT and SBT was 56,000 tons in 2004. In Abroad, the tuna farming business forms a fixed connection between the importer and the wholesaler which have their office in Japan. In the field of the capital composition, the payment in advance, transaction and the way of settlement, each maintains their fixed relation. The market conditions of the cultured tuna are supported by "the decline of price level" and "the expansion of the general public consumption segment". These lead a team merchandising, and it is supported by the fixed business connection of each. This makes the profit of each business which are on the cultured tuna distribution. However, they have competition on the power balance among them.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.35 no.1
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• pp.25-34
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• 1999

The Steering and Sailing Rules of International Regulation for Preventing Collisions at Sea now in use direct actions to avoid collision when two power-driven vessels are meeting on reciprocal or nearly reciprocal courses so as to involve risk of collision. But these rules do not refer to the minimum relative distances and safety relative distances between two vessels when they should take such actions.In this paper the ship's collision avoiding actions being analyzed from a viewpoint of ship motions, the mathematical formulas to calculate such relative distances necessary for taking actions to avoid collision were worked out. The values of maneuvering indices being figured out through experiments of 20 actual ships of small, medium, large and mammoth size and applied to calculating formulas, the minimum relative distances and safety relative distances were calculated. The main results were as follows. 1. It was confirmed that the criterion elements for collision avoiding actions in head-on situation of two vessels shall be the minimum relative distances and safety relative distances between them. 2. On the assumption that two vessels same in size and condition were approaching each other in head-on situation, the minimum relative distance of small vessel(GT : 160~650tons) was found to be about 4.7 times her own length, and those of medium (GT:2,300~4,500tons),large(GT:15,000~62,000tons) and mommoth (GT:91,000~194,000tons) vessels were found to be about 5.2 times, about 5.2 times and about 6.1 times their own lengths respectively. 3. On the assumption that two vessels same in size and condition were approaching each other in head-on situation, the safe relative distance of small vessel (GT : 160~650tons) was found to be about 6.8 times her own length, and those of medium (GT : 2,300~4,500tons), large (GT: 15,000~62,000tons) and mammoth (GT : 91,000~194,000tons) vessels were found to be about 9.0 times, about 6.3 times, and about 8.0 times their own lengths respectively. 4. It is considered to be helpful for the safety of ship handling that the sufficient safe relative distances for every vessels shall be more than about 12~14 times which are 2 times minimum relative distance, their own length on above assumption.

• Journal of Korea Technology Innovation Society
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• v.16 no.1
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• pp.252-278
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• 2013

Many countries implement an offset program as a method of the acquisition of modern military technology for enhancement of the domestic military strength. Offset agreements are made based on the value, not a monetary unit. The value should be above minimum threshold fixed by the related regulation. Hence, technology valuation model which is objective and reasonable is required vitally. At present, some defense related organizations such as DTaQ, ADD valuate the proposed technology by using their own method. However, due to the lack of differentiation of valuation analysis indicators for various technologies, existing offset valuation models are inadequate to consider whole characteristics of such technologies. In this paper, we developed four sets of offset valuation analysis indicators considering the characteristics of each technology, parts production, depot maintenance, military equipment performance upgrade, and R&D related technology, by using the Delphi method. Also, we structurized those indicators in each technology by using the factor analysis. Through applying developed indicators, it is expected that technology valuation in the offset program would be more credible and accurate. Ultimately, it gives greater bargaining power to negotiators in the procedure of the offset negotiation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.618-624
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• 2017

In Seoul and most metropolitan cities, urban trains are delayed due to high congestion during commute times. The delay effect of passengers boarding and disembarking is also significant. In this study, a wide passenger door system was developed as a way to improve the scheduled speed of urban trains by decreasing the passengers' flow time. The door size was defined experimentally to shorten the entrance time. The optimum door size was also determined to improve the stop precision performance of the train while considering the interference effect with peripheral devices. Because the change in door size changes the structural characteristics of the vehicle, the structural stability of a train was analyzed numerically. A prototype of the wide door system was made, and the proposed design was verified using functional and endurance tests. The systematic development process can be used as design data for door size definition and system production when applying a wide door to improve the scheduled speed.

• Cartoon and Animation Studies
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• s.17
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• pp.53-67
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• 2009

According to the changes of current regulation of media, the broadcasting environment has been loosened by market power, and came into competitive era for broadcasting industry with new technology of combined broadcasting and communication. To resolve these issues, the broadcasting provides are trying process of new channel brand identity to introduce their channels. The purpose of the research is to analyze Spot animation that has fast access to viewers among channel brand identity factors, review expandability and usage of Spot animation character to plan, manage character that can improve awareness and loyalty. Therefore it will study creation background and production, activities of each character representing KBS and MBC, compare the structure, color, material, expression of Spot animation character and summarize properties. To conclusion, three characters of KBS and MBC failed to apply structured and professional plan and management, only expressed image that each channel pursue on Station ID Spot animation and had issues of not deeply sighting expandability and usefulness as a character. The important factor to improve channel brand value of broadcasting provider is to have differentiated identity, and the core of it is to make image-responsible Station ID to be effective. Therefore, Spot animation and character of Station ID is a very important factor so there must be professional research and structural management from the early planning and production for character that represents the providers.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.10
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• pp.767-773
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• 2011

The purpose of this study was to investigate the possibility of an alternative fuel resource by incinerating a mix of combustible MSW (municipal solid waste) and offals after separating recyclable material at the MRF (material recovery facilities) location. We analyzed the physical and chemical properties including the 3-contents, the calorific value, and chemical compositions of the separation rejects in MRF, and compared the results with combustible MSW. Moreover, we experimented the trend of combustible properties and the concentration change of air pollutants at mixed incineration in the MSW incinerator. According to the results of the experiment, the separation rejects showed higher heating value (5,865 kcal/kg), and lower moisture and ash content than combustible MSW. Since we have incinerated MSW in the MSW incinerator mixing the offals at 30% and 50% respectively, we know that the change of the concentration of dust, $SO_2$, $NO_2$, and CO did not appear significant, and not exceed the pollutants emission regulation. But, considering the enhancement of the HCl emission concentration (max. 33.7 ppm) at the co-incineration of the 50% offals, we believe that the proper mixing ratio of the separation rejects would become within 30%.

• Elastomers and Composites
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• v.46 no.4
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• pp.335-342
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• 2011

The virgin and recycled polyethylene composites with various ratio of fly ash were manufactured by using a fully intermeshing co-rotating twin screw extruder for the reuse of fly ash from power plant and post-consumed polyethylene. Fly ash were blended with virgin HDPE and recycled polyethylene at the weight fraction of 0 to 40 wt.%. Mechanical properties such as yield strength, abrasion resistance, and slow crack resistance were measured with ISO and ASTM standards. The experimental results for the various composites showed that the elongation at break and the yield stress of the composites decreased with increasing fly ash contents. Generally, the abrasion resistance of PEs decreased with increasing sandpaper grits but the abrasion resistance of the composites increased with fly ash content at finer abrasive surface. The slow crack growth resistance of virgin HDPE, recycled JRPE and the JRPE composite showed higher slow crack growth resistance up to 50% of load at notch depth of 20% and 30%, but KRPE and the KRPE composite showed much lower resistance than virgin HDPE, JRPE and the JRPE composite. Time to break, measured with NCLS test method, of all PEs and the composites satisfies the regulation of Korean Industrial Specification for sewer pipe and support application.

• Journal of Service Research and Studies
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• v.4 no.2
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• pp.1-10
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• 2014

According to recent trends in technological advances and globalization, medical device industry may improve the constitution to meet worldwide medical equipment management system. Also it is holding a strand of mitigation to reach the level of international regulation. In addition, recent legislation tends are to stay limited ranges of industry regulations at least and take as open attitude for integration of new technologies combined medical devices. A greater environmental risk is not likely to work in medical technology, Combinded medical device is used as close to zero risk in most of the human body, which is classified as Class 1. Even medical device such as little or no risk in handling, it is possible to minimize the unnecessary administrative power and a waste of time to occur. For the medical device may be improving people's choices and access, medical equipment operator is expanding to include dealers, because this will be exalted to particular area of the business of the company. In this paper, we investigate the legal prerequisites for the establishment of a medical device. And propose improved regulations in topics in order to facilitate the repair and distribution markets for fair trade.

• Journal of the Korea Concrete Institute
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• v.15 no.6
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• pp.840-847
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• 2003

Recently, the coal-ash production has been increased by increase of consumption of electric power. So it is important to secure a reclaimed land and treatment utility for coal-ash. This is an experimental study to compare and analyze the engineering properties of concrete according to W/C and replacement ratio of bottom ash. For this purpose, the mix proportions of concrete according to W/C(40, 50, 60%) and replacement ratio of bottom ash(0, 10, 20, 35, 50%) were established, and then tested for slump, chloride content, setting time, bleeding content, compressive strength. Also the durability test of concrete with W/E 60% was performed. According to test results, it was found that the bleeding content of concrete decreased as the replacement ratio of bottom ash increased. And the chloride content of concrete using the bottom ash increased as the replacement ratio of bottom ash increased, but it is satisfied with the chloride content of fresh concrete $0.30kg/m^3$ below("concrete standard specification" regulation value). The compressive strength of concrete using the bottom ash was similar to that of BA0 concrete after 28 days of curing and the carbonation depth of concrete was increased according to increase of the replacement ratio of bottom ash.