• Journal of Navigation and Port Research
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• v.34 no.10
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• pp.775-780
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• 2010

In the machinery, the brake system is as important part as machine's working. The situation of emergency stop, the machine doesn't stopped would be occur big accident. This is common things for all of machinery, also for the ships. There are two kind of mooring devices are existed on the ship. One of them, the windlass winch, is used to anchor. The other, the mooring winch is used to moor the ship in pier use the rope tied to bitt on dock. In case of previously been used mooring winch made of a steel plate, and the bolt which was connect brake band and lining broken. In this study, prevent an accident find the position of stress concentration by finite element analysis program. And removed stress concentration. And search the optimum position of the separation angle to be more efficient.

• Journal of the Korean Society for Library and Information Science
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• v.43 no.1
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• pp.235-250
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• 2009

This study analysed the user behaviors and satisfaction for the government information service of Nation Assembly Library of Korea, based on the questionnaires from users including the legislative employees and other library users. The results showed that legislative employees used the services more often and have more needs for the services than other users. Most legislative employees and other library users evaluated that the services should be improved and that it would be desirable to develop a portal system and services providing the integrated search and offering government information as one stop service.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2534-2540
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• 2010

In this paper we propose contents and results on installation and commissioning test for ATP on-board unit, which has propelled as one of the research projects, so called, "Reliability assessment and operation technology development for Korean-type tilting trains" in order to ensure the safety and operation efficiency of tilting trains. In KRRI, we have developed tilting trains for the speed-up of existing lines and for the passenger service improvement where the KTX is not available. And we also make progress the operation trial test at the speed of 10km with the use of ATS units, used in existing lines, for the purpose of the reliability assessment of the developed tilting trains. In MLTM, they have decided to accelerate the speed at more than 200km/h for the 7 existing lines including Jungang-line and Chungbuk-line where KTX has not operated. According to this decision, Train control system is to be changed from ATS to ATP. We should install an ATP on-board unit in tilting trains and verify the operational suitability. Therefore, we have installed and tested the same ATP on-board unit on tilting trains that used in the ATP construction project on Gyeongbu-line and Honam-line.

• Genes and Genomics
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• v.40 no.11
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• pp.1199-1211
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• 2018

Soil acidification is one of major problems limiting crop growth and especially becoming increasingly serious in China owing to excessive use of nitrogen fertilizer. Only the STOP1 of Arabidopsis was identified clearly sensitive to proton rhizotoxicity and the molecular mechanism for proton toxicity tolerance of plants is still poorly understood. The main objective of this study was to investigate the transcriptomic change in plants under the low pH stress. The low pH as a single factor was employed to induce the response of the wheat seedling roots. Wheat cDNA microarray was used to identify differentially expressed genes (DEGs). A total of 1057 DEGs were identified, of which 761 genes were up-regulated and 296 were down-regulated. The greater percentage of up-regulated genes involved in developmental processes, immune system processes, multi-organism processes, positive regulation of biological processes and metabolic processes of the biological processes. The more proportion of down-regulation genes belong to the molecular function category including transporter activity, antioxidant activity and molecular transducer activity and to the extracellular region of the cellular components category. Moreover, most genes among 41 genes involved in ion binding, 17 WAKY transcription factor genes and 17 genes related to transport activity were up-regulated. KEGG analysis showed that the jasmonate signal transduction and flavonoid biosynthesis might play important roles in response to the low pH stress in wheat seedling roots. Based on the data, it is can be deduced that WRKY transcription factors might play a critical role in the transcriptional regulation, and the alkalifying of the rhizosphere might be the earliest response process to low pH stress in wheat seedling roots. These results provide a basis to reveal the molecular mechanism of proton toxicity tolerance in plants.

• Korea Trade Review
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• v.45 no.5
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• pp.141-159
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• 2020

Container terminals at Gwangyang Port are operated by three container operators: A, B and C. Ultimately, there is consensus that a single operator should operate all terminals so that economies of scale can be achieved even in the operation of the container terminal. Integration between operators has a positive effect on both operators and shipping companies. From the operator's point of view, overlapping fixed costs between operators can be unified, reducing overall costs and utilizing spare facilities. On the other hand, from the viewpoint of the shipping company, it is possible to ensure stable use of the port facilities and always allow berthing, reduce days on demurrage and ship waiting, and provide one-stop service for work. However, existing cases of operators' integration or relocation of terminals remained to estimate the expected effects of alternatives, emphasizing only the financial point of view. The port terminal is a large system, and it is important to consider that it is an aggregate of major logistics facilities and equipment. Moreover, if the estimation can be made by quantifying the expected effect, the justification of the terminals' relocation can be further emphasized. Therefore, it is very important to estimate the expected effect from the viewpoint of systemic operation. Moreover, the need for operators' integration can be further emphasized if it can be estimated through quantification of expected effects. Currently, three alternatives are considered as alternatives to the terminals' relocation, and in this study, the optimal plan was derived for the 3 alternatives by the linear planning model of the minimum shuttle transportation cost in the terminal. The optimal plan is alternative 2, which shows the most advantageous integration effect in terms of expected effects. Alternative 2 integrates the B terminal into the C terminal, and the A terminal operates independently as it is.

• Progress in Medical Physics
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• v.26 no.2
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• pp.87-92
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• 2015

The gated RapidArc may produce a dosimetric error due to the stop-and-go motion of heavy gantry which can misalign the gantry restart position and reduce the accuracy of important factors in RapidArc delivery such as MLC movement and gantry speed. In this study, the effect of stop-and-go motion in gated RapidArc was analyzed with varying gating window time, which determines the total number of stop-and-go motions. Total 10 RapidArc plans for treatment of liver cancer were prepared. The RPM gating system and the moving phantom were used to set up the accurate gating window time. Two different delivery quality assurance (DQA) plans were created for each RapidArc plan. One is the portal dosimetry plan and the other is MapCHECK2 plan. The respiratory cycle was set to 4 sec and DQA plans were delivered with three different gating conditions: no gating, 1-sec gating window, and 2-sec gating window. The error between calculated dose and measured dose was evaluated based on the pass rate calculated using the gamma evaluation method with 3%/3 mm criteria. The average pass rates in the portal dosimetry plans were $98.72{\pm}0.82%$, $94.91{\pm}1.64%$, and $98.23{\pm}0.97%$ for no gating, 1-sec gating, and 2-sec gating, respectively. The average pass rates in MapCHECK2 plans were $97.80{\pm}0.91%$, $95.38{\pm}1.31%$, and $97.50{\pm}0.96%$ for no gating, 1-sec gating, and 2-sec gating, respectively. We verified that the dosimetric accuracy of gated RapidArc increases as gating window time increases and efforts should be made to increase gating window time during the RapidArc treatment process.

• Korean Security Journal
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• no.59
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• pp.217-242
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• 2019

Nowadays, Terrorism has become bloodier. Unlike the past, the recent terrorism has been indiscriminate in the purpose of mass- killing. Given this aspect, the threat of a CBRN attack is the biggest one to modern society. Notably, the possibility of terrorist attacks in Korea by international terrorist groups such as ISIL is higher than ever in consideration of its allusion; crusades and the devil's allied forces. To overcome these circumstances, various measures have been taken for counter terrorism at the state level including anti-terrorist legislation. Under the anti-terrorist act, police have to lead relevant inter agencies when it comes to the CBRN terror. At first glance, current countermeasures would work well. However, in order to respond quickly, the standing cooperations system of related departments need to be set up. In this sense, this article proposed a coagulatory body that could not only consider institutional-oriented organizational restructuring and response but also integrate and operate functions of various specialized institutions. It also stressed that the council should move toward a consultative body of information gathering, distribution and working- level consultation. With this cooperation system, counter-terrorism agencies can respond rapidly, stop wasting their effort and assets by about 30%. Also, they could design the atypical aspect of terrorism into standardized.

• Journal of Technologic Dentistry
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• v.35 no.3
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• pp.243-257
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• 2013

Purpose: This study aims to analyze the factors affecting the dropout intentions of the dental technology students of a college. Methods: The subject of this study was 76 freshmen and 74 sophomores of dental technician major in an anonymous college. Results from the questionnaire called K-vision diagnosis program were computed by means of t-test, One-Way ANOVA, and correlation analysis. Results: 1. Total points of the drop out intention came to 782.14 points. Of the five categories concerned with the drop out intention, complain in college satisfaction(50.12points) was the highest and department satisfaction(47.51points) was the lowest. Of 16 subcategories, complaining in administrative supporting system proved the highest as 50.80 points and Inquiry to Professor the lowest(45.56 points). 2. Among the general characteristic gender (p<. 01), student group (p<.01), and credit (p<.05) made a meaningful statistical difference; no statistical significance was found in grade, admission, and dwellings. 3. Of the five categories, statistical significance was shown as follows; Department satisfaction (p<.01), College satisfaction (p<.05) under gender, Department satisfaction (p<.05) in grade, Academic integration (p<.01), Department satisfaction (p<.01) in credit. No statistical meaning was found in admission and dwellings. 4. Statistical significance was found under 16 subcategories as follows: Career identification(p<.01), Academic support system(p<.01), Social activity II(p<.05) in gender area, Inquiry to professor(p<.01), Learning(p<.05), Understanding learning I(p<.05) in grade area, Learning(p<.001), Career identification(p<.001), Understanding learning I(p<.01), Understanding learning II(p<.01), Inquiry to professor (p<.01), Learning ability (p<.05), Occupation (p<.05), Social Activity II(p<.05), Administrative support system (p<.05) in student group area, Credit (p<.001), Career identification (p<.01), Understanding learning I(p<.05) in credit area; admission and dwellings was statistically meaningless. 5. Of the 5 categories academic integration (r=.766) was most relevant to the dropout intention of the subjects and followed by department satisfaction (r=.735), college satisfaction (r=.554), service acceptability (r=.373), and statistical significance was shown as p<.01. Conclusion: Considering the results of this study, we are in a pressing need for the introduction of policies and programmes aiming at preventing the dropout rates of the dental technician majors at college. In tandem with this, qualitative and viable human resource management of the dental technicians should be implemented.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.1115-1122
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• 2013

Recently the demands for traffic information tend to increase, and travel time might one of the most important traffic information. To effectively estimate exact travel time, highly reliable traffic data collection is required. BIS(Bus Information System) data would be useful for the estimation of the route travel time because BIS is collecting data for the bus travel time on the main road of the city on real-time basis. Traditionally use of BIS data has been limited to the realm of bus operating but it has not been used for a variety of traffic categories. Therefore, this study estimates a route travel time on road networks in urban areas on the basis of real-time data of BIS and then eventually constructs regression models. These models use an explanatory variable that corresponds to bus travel time excluding service time at the bus stop. The results show that the coefficient of determination for the constructed regression model is more than 0.950. As a result of T-test performance with assistance from collected data and estimated model values, it is likely that the model is statistically significant with a confidence level of 95%. It is generally found that the estimation for the exact travel time on real-time basis is plausible if the BIS data is used.

• Journal of The Korean Association of Information Education
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• v.8 no.2
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• pp.155-164
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• 2004

In the field of number and operation of mathematics, a learner's learning deficit in one year can disturb or obstruct his or her learning in the following year, which is an obvious characteristic in math education. But the problem doesn't stop here. It may increase poor learning in the related math field or, in a serious case, cause mathematical learning incompetence. In the other hand, a teacher must guide a class of about 40 students and take charge of overburdensome routine; it's really impossible for him or her to secure individual teaching time for poor learners and to give lessons considering their individual poor learning elements. In order to solve these problems, this study has found out some poor learning elements from poor learners in teaching mathematical number and operation, offered learning fit for them, and allowed them to approach a learning system regardless of time and space. And it has embodied a web-based learning system for operation field underachiever in elementary school, applied it to the scene of education, and analyzed the results so that a teacher may manage their learning results by DB and guide poor learners systematically. As a consequence, the study could reduce a teacher's teaching overburden and at the same time, raise the learning accomplishments of poor learners.