• Reproductive and Developmental Biology
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• v.33 no.3
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• pp.171-177
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• 2009

Spermatogonial stem cells(SSCs) only are responsible for the generation of progeny and for the transmission of genetic information to the next generation in male. Other in vitro studies have cultured SSCs for proliferation, differentiation, and genetic modification in mouse and rat. Currently, information regarding in vitro culture of porcine Germline Stem Cell(GSC) such as gonocyte or SSC is limited and is in need of further studies. Therefore, in this study, we report development of a successful culture system for gonocytes of neonatal porcine testes. Testis cells were extracted from $10{\sim}14$-day-old pigs. These cells were harvested using enzymatic digestion, and the harvested cells were purified with combination of percoll, laminin, and gelatin selection techniques. The most effective culture system of porcine gonocytes was established through trial experiments which made a comparison between different feeder cells, medium, serum concentrations, temperatures, and $O_2$ tensions. Taken together, the optimal condition was established using C166 or Mouse Embryonic Fibroblast(MEF) feeder cell, Rat Serum Free Medium(RSFM), 0% serum concentration, $37^{\circ}C$ temperature, and $O_2$ 20% tension. Although we discovered the optimal culture condition for proliferation of porcine gonocytes, the gonocyte colonies ceased to expand after one month. These results suggest inadequate acquirement of ingredients essential for long term culture of porcine GSCs. Consequently, further study should be conducted to establish a successful long-term culture system for porcine GSCs by introducing various growth factors or nutrients.

• Journal of Engineering Education Research
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• v.8 no.3
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• pp.57-68
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• 2005

The purpose of this study was to analyze the effect of Engineering computer programming instruction using project learning, to find out the ways to solve some revealed problems, and to improve the instruction. Unlike traditional lecture courses, students are encouraged to cultivate problem solving and teamwork skills through the programming project. In order to examine the effect of project learning, a survey was conducted with 49 students. The questionnaire consisted of 20 items with 5-grade scale each, the contents of which included learning value, workload, skills acquirement, assignment and comment. The SPSS, statistical analysis software was used to get statistics such as ANOVA, correlation and mean, etc. The results of this study showed (1) project learning was more efficient to acquire problem solving and teamwork skills compared with lecture learning, (2) there was significant correlation between self directed learning skill and information collecting skill, (3) cyber education system(i-campus) was helpful for students' self learning. But the results also showed that (4) students did not give high scores on items of the workload or difficulty of assignments. So we can conclude that it is necessary to develop the suitable projects for the capability of students to make the better project learning.

• Journal of Distribution Science
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• v.8 no.3
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• pp.5-15
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• 2010

Business corporations have become specialized and on the basis of various interests try to strengthen their competitiveness through a cooperative system of purchase, distribution, service and IT technology. And an advanced Internet-based electronic commerce has witnessed explosive growth and a business-to-business (B2B) electronic commerce. Through E-marketplace. business corporations achieve such diverse utilities as expenditure curtailment, process reduction and prime cost reduction. And with business depression worldwide and soaring prices of materials, many business corporations consider the introduction of comprehensive purchase of MRO (maintenance, repair and operation) materials. The Purpose of this study was to examine the definition of B2B E-marketplace and the utilities of MRO commerce correctly focusing on an empirical analysis of cases of MRO supply and purchase business corporations. The indications acquired from this research results are as follows. Firstly, as for MRO integrated purchase under the characteristics of the market environment, it had to use the supplier obligatorily through the integrated purchase on the level of CEO's decision-making or the group rather than the voluntary will of the purchasing department or the procurement department. Secondly, as for the present B2B E-marketplace MRO purchase, the purchasing agency business has formed the mainstream, but it is aiming at the diversification of the benefit by supplementing/correcting the business model such as category type, mediation business type, MRO-type advancing in the store inclusive of the purchasing agency business, keeping pace with the potential market of MRO. Thirdly, as for analysis of the products, the purchaser wants more various products and assortment of goods than those of the present time, and also to be provided with the precise product information. Especially, as the importance of the product sourcing becomes high, the whole energy has been bestowed on acquirement of the excellent suppliers. Fourth, as for use of B2B E-marketplace MRO integrated purchasing system, there are the purchasing companies complaining the inconvenience even until now, and there is the demerit spending the long time during the image move and the process treatment. It shall try to shorten the searching time and the process treatment time as the system is centered on the purchaser. In order to enhance the efficiency of MRO E-marketplace purchase, followings must be considered: First, because the importance of product sources ever increases, an excellent supplier must be secured earnestly. Second, the time of process must be reduced focusing on purchasers. B2B E-marketplace will increase and diversify electronic commerce continuously. Through MRO E-marketplace, business corporations will reduce expenditure, achieve a transparent and speedy trade, and purchase products of fine quality, thus establishing a most effective market. In addition, in this study the investigator brings focus into MRO which has not been clearly discussed in the academic and business world so far and intensively highlights an indirect material-oriented expenditure curtailment effect. By taking all the aspects of supplier, purchaser and practical economical value into account, the investigator presents a strategic direction for the successful comprehensive purchase of B2B MRO.

• Journal of Conservation Science
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• v.27 no.2
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• pp.181-190
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• 2011

A precision measurement and digital image restoration of the 5th century's gilt bronze cap of Baekje dynasty, excavated from the ancient tomb of Andong, Goheung in 2006, was undertaken. The objective of the scanning is to preserve precise feature of the artefact in the form of digital data by embodying it in 3 dimensional space. Acquirement of the data has been undertaken in the following process : 3D scanning to obtain 3D shape and color information(original data photographing)-3D modelling(joining original data and restoring non-photographed or damaged area)-CG image production. Production of restoration CG image was based on joined shape of original data and each part's measurement on CAD. Non-photographed part and area of loss was restored referring actual measurement and research result of excavated cap from the 5th to 8th century. 3D image restoration is one of artefact restoration methods which restores artefact without risk. It is also undertaken with historical research. As result, this method can enhance aesthetic and academic value of the artefact by successful restoration.

• Journal of Korean Society of Forest Science
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• v.82 no.1
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• pp.1-6
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• 1993

This study was conducted to provide a fundamental information for a income raise of agricultural and mountain villagers and a policy planning by analyzing 145 chestnut producing farms in Korea. The results of this study are as follows : 1. Though the proportion of forest by-products in farm household economy was very slight, it is very important for agricultural and mountain villagers who have relatively lower income level to become a valuable income source. 2. As chestnut cultivating orchards have very small-scale that account for 50.0% of 0.5 to 1.0 hectares and 40.3% of 1.0 to 3.0 hectares reaching 90.3% of total farmers, the small-scale ownership makes the normality and rationalization of management difficult, and therefore the economity of scale has to be accomplished. 3. The difficulties on chestnut cultivating management were in order of the following ; Labour-power shortage(38.5%), desease and pest demage(24.8%), economity(15.2%), management(11.7%), inferiority of site condition(5.9%), technical acquirement(3.8%). 4. In the matter of storaging facilities, 87.6% of total surveyed farmers were recognizing the need of storaging facilities, but only 12.4 of surveyed farmers were possessing these facilities, and therefore the measurement has to be considered such as the forest associations invests to cold storaging facilities unable to privately invest, in order to increase a receiving price of producers.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.1
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• pp.53-62
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• 2016

In recent years, UAV Photogrammetry based on an ultra-light UAS(Unmanned Aerial System) installed with a low-cost compact navigation device and a camera has attracted great attention through fast and accurate acquirement of geo-spatial data. In particular, UAV Photogrammetry do gradually replace the traditional aerial photogrammetry because it is able to produce DEMs(Digital Elevation Models) and Orthophotos rapidly owing to large amounts of high resolution image collection by a low-cost camera and image processing software combined with computer vision technique. With these advantages, UAV-Photogrammetry has therefore been applying to a large scale mapping and cadastral surveying that require accurate position information. This paper presents experimental results of an accuracy performance test with images of 4cm GSD from a fixed wing UAS to demarcate parcel boundaries in agricultural area. Consequently, the accuracy of boundary point extracted from UAS orthoimage has shown less than 8cm compared with that of terrestrial cadastral surveying. This means that UAV images satisfy the tolerance limit of distance error in cadastral surveying for the scale of 1: 500. And also, the area deviation is negligible small, about 0.2%(3.3m²), against true area of 1,969m² by cadastral surveying. UAV-Photogrammetry is therefore as a promising technology to demarcate parcel boundaries.

• The KIPS Transactions:PartA
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• v.12A no.6 s.96
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• pp.557-562
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• 2005

Throughput and latency of interconnection network are important factors of the performance of multiprocessor systems. The dual-link CC-NUMA architecture using point-to-point unidirectional link is one of the popular structures in high-end commercial systems. In terms of optimal path between nodes, several paths exist with the optimal hop count by its native multi-path structure. Furthermore, transaction latency between nodes is affected by congestion of links on the transaction path. Hence the transaction latency may get worse if the transactions make a hot spot on some links. In this paper, I propose a dynamic transaction routing algorithm that maintains the balanced link utilization with the optimal path length, and I compare the performance with the fixed path method on the dual-link CC-NUMA systems. By the proposed method, the link competition is alleviated by the real-time path selection, and consequently, dynamic transaction algorithm shows a better performance. The program-driven simulation results show $1{\~}10\%$ improved fluctuation of link utilization, $1{\~}3\%$ enhanced acquirement of link, and $1{\~}6\%$ improved system performance.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2007.05a
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• pp.234-245
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• 2007

The empirical studies on the implementation of data warehousing systems (DWS) are lacking while there exist a number of studies on the implementation of IS. This study intends to examine the factors affecting the implementation success of DWS. The study adopts the empirical analysis of the sample of 112 responses from DWS practitioners. The study results suggest several implications for researchers and practitioners. First, when the support from top management becomes great, the implementation success of DWS in organizational aspects is more likely. When the support from top management exists, users are more likely to be encouraged to use DWS, and organizational resistance to use DWS is well coped with increasing the possibility of implementation success of DWS. The support of resource increases the implementation success of DWS in project aspects while it is not significantly related to the implementation success of DWS in organizational aspects. The support of funds, human resources, and other efforts enhances the possibility of successful implementation of project; the project does not exceed the time and resource budgets and meet the functional requirements. The effect of resource support, however, is not significantly related to the organizational success. The user involvement in systems implementation affects the implementation success of DWS in organizational and project aspects. The success of DWS implementation is significantly related to the users' commitment to the project and the proactive involvement in the implementation tasks. users' task. The observation of the behaviors of competitors which possibly increases data quality does not affect the implementation success of DWS. This indicates that the quality of data such as data consistency and accuracy is not ensured through the understanding of the behaviors of competitors, and this does not affect the data integration and the successful implementation of DWS projects. The prototyping for the DWS implementation positively affects the implementation success of DWS. This indicates that the extent of understanding requirements and the communication among project members increases the implementation success of DWS. Developing the prototypes for DWS ensures the acquirement of accurate or integrated data, the flexible processing of data, and the adaptation into new organizational conditions. The extent of consulting activities in DWS projects increases the implementation success of DWS in project aspects. The continuous support for consulting activities and technology transfer enhances the adherence to the project schedule preventing the exceeding use of project budget and ensuring the implementation of intended system functions; this ultimately leads to the successful implementation of DWS projects. The research hypothesis that the capability of project teams affects the implementation success of DWS is rejected. The technical ability of team members and human relationship skills themselves do not affect the successful implementation of DWS projects. The quality of the system which provided data to DWS affects the implementation success of DWS in technical aspects. The standardization of data definition and the commitment to the technical standard increase the possibility of overcoming the technical problems of DWS. Further, the development technology of DWS affects the implementation success of DWS. The hardware, software, implementation methodology, and implementation tools contribute to effective integration and classification of data in various forms. In addition, the implementation success of DWS in organizational and project aspects increases the data quality and system quality of DWS while the implementation success of DWS in technical aspects does not affect the data quality and system quality of DWS. The data and systems quality increases the effective processing of individual tasks, and reduces the decision making times and efforts enhancing the perceived benefits of DWS.

• Journal of fish pathology
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• v.9 no.2
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• pp.185-193
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• 1996

Extensive acquirement of drug resistance to traditional antibacterial agents poses a serious problem to eel aquaculturists. To collect the basic information for new drug development in the future, we assessed the in vitro antibacterial efficacy of 14 new quinolones with 75 isolates of Edwardsiella tarda from local aquaculture tanks of Anguilla japonica. Of all tested quinolones under development or marketed for human use, DU-6859 was most potent with its $MIC_{50}$ value of $0.05{\mu}g$/ml in broth microdilution assay. The drugs whose $MIC_{50}$ values ranged from 0.2 to $0.78{\mu}g$/ml were T-3762, Bay-y3118, ciprofloxacin, norfloxacin, ofloxcin and tosufloxacin. The weakest group of drugs, with their $MIC_{50}$ being 1.56-$3.13{\mu}g$/ml, were difloxacin, sparfloxacin, fleroxacin, Q-35, amifloxacin, lomefloxacin and enoxacin. The number of resistant strains, when arbitrarily defined with their MICs of $\geq6.25{\mu}g$/ml, was : 3 to T-3762, 3 to Bay-y3118, 44 to difloxacin, 16 to sparfloxacin, 13 to ciprofloxacin, 19 to fleroxacin, 36 to Q-35). 31 to amifloxacin, 5 to norfloxacin, 13 to ofloxacin, 31 to lomefloxacin, 41 to enoxacin, 12 to tosufloxacin and 0% to DU-6859, respectively. This information can be taken into consideration for the future development of fisheries antibacterial quinolones.

• Journal of Radiation Protection and Research
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• v.39 no.2
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• pp.118-126
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• 2014

A survey was conducted on perceptions, knowledge, and attitudes of elementary, middle, and high school students, who will lead public opinion in the future, regarding irradiated food, nuclear power generation, and medical radiation. These topics urgently require general social acceptability among various fields in which radiation is used. Educational methods to enhance social acceptability were partially discovered. First, it is necessary to implement different strategies when designing courses for female and male students. Male students have higher levels of objective knowledge (p<0.039) of irradiated food, necessity (p<0.001) and objective knowledge (p<0.001) of nuclear power generation, approval of building a nuclear power plant in the nation (p<0.001), necessity (p<0.001) and objective knowledge (p<0.001) of medical radiation, and attitudes regarding using medical radiation (p<0.007, p<0.001). Second, the educational effect of explanations to help increase national understanding of the necessity and safety of nuclear power generation will increase if information on the necessity and safety of medical radiation is provided as well. Both male and female students perceived that medical radiation is the most necessary (p<0.001), medical radiation is the safest (p<0.001), and nuclear power generation is the least safe (p<0.013). Moreover, the correlation between medical radiation and nuclear power generation was the highest. Third, there is a need for different lectures between classes, since the patterns of perception vary according to the field of radiation use among elementary, middle, and high school students. Elementary school students had high interest in education on nuclear power generation (p<0.005), perceived that irradiated food is safe (p<0.001), and had the most positive attitude toward consuming irradiated food (p<0.001). Middle school students had high interest in education on nuclear power generation (p<0.018), perceived that nuclear power generation (p<0.001) and medical radiation (p<0.002) are safe, and had the most positive attitude toward using radiation for treatment (p<0.001). High school students had the highest level of objective knowledge on nuclear power generation (p<0.001) and medical radiation (p<0.001), and perceived that medical radiation is the most necessary (p<0.017); however, they perceived that nuclear power generation is the least safe (p<0.001). Attitudes toward irradiated food intake (p<0.001) and approving construction of a nuclear power plant in their neighborhood (p<0.001) were both low. Fourth, it is necessary to provide educational programs to change perceptions and improve attitudes rather than providing education focused on objective knowledge. There was no correlation between objective knowledge and necessity of irradiated food, objective knowledge and safety and interest in education on nuclear power generation, and objective knowledge and interest in education and information acquirement regarding medical radiation. In particular, high school students had the highest level of objective knowledge and yet had the least positive attitudes toward approving construction of nuclear power plants in their neighborhood and intake of irradiated food. Therefore, to increase the social acceptability of using nuclear energy and radiation in Korea, it is desirable to provide strategic educational programs to improve perceptions, knowledge, and attitudes regarding the necessity and safety of their use.