• Journal of KIISE:Databases
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• v.31 no.5
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• pp.492-504
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• 2004

Recently, as growing of interest for LBS(location-based services) techniques, lots of works on moving objects that continuously change their information over time, have been performed briskly. Also, researches for NN(nearest neighbor) query which has often been used in LBS, are progressed variously However, the results of conventional NN Query processing techniques may be invalidated as the query and data objects move. Therefore, they are usually meaningless in moving object management system such as LBS. To solve these problems, in this paper we propose a new nearest neighbor query processing technique, called CTNN, which is possible to meet accurate and continuous query processing for moving objects. Our techniques include an Approximate CTNN(ACTNN) technique, which has quick response time, and an Exact CTNN(ECTNN) technique, which makes it possible to search nearest neighbor objects accurately. In order to evaluate the proposed techniques, we experimented with various datasets. Experimental results showed that the ECTNN technique has high accuracy, but has a little low performance for response time. Also the ACTNN technique has low accuracy comparing with the ECTNN, but has quick response time The proposed techniques can be applied to navigation system, traffic control system, distribution information system, etc., and specially are most suitable when both data and query are moving objects and when we already know their trajectory.

• The Korean Journal of Air & Space Law and Policy
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• v.17
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• pp.111-132
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• 2003

The air transport industry is the most important as means of human exchange between the countries. Because the spread effect and the durability by aviation cooperation between the countries are much higher than any other industry, a research about air transport industry is very important to allied industry field as well as national policy about International cooperation and integration. Specially, according to the economic interchange with North Korea becomes active, the role of air transport as related traffic network with North Korea becomes more important. The number of flights is increasing sharply after South-North summit meeting, and two sides established and are using temporary direct route between South-North Korea. When we consider that the number of flights utilizing temporary direct route is increasing every year, It is not desirable to use temporary routes continuously because the current agreement between South and North cant be reliable far the case of unexpected circumstance. In addition, the current agreement is not based on the international standards. The paper is to study the condition to promote the coordination of civil aviation in the whole Korean peninsula. As known, the aviation system in North Korea is mainly operated by military unit. The study will review the current status of air transport system of South and North and the effective way of cooperation of civil aviation between both sides. The cooperation between governments as well as between airlines is studied. The establishment of Air Traffic Service Agreement is going to be handled heavily because the stable air traffic service is the most required base for the operation of air transport. The authors also try to find a way to support the development of infrastructure of aviation industry in North Korea.

• Korean Journal of Environment and Ecology
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• v.21 no.6
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• pp.526-535
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• 2007

This study was conducted at the Civilian Controlled Zone(CCZ) in the Cherowon from February to March 2004 to investigate the reaction to the vehicles of Red-crowned Cranes(RCC) and White-naped Cranes(WNC) and trade-off of the vehicle interruption with food resources. The for-aging distance from the road of WNC was much closer than that of RCC. The large flocks of cranes' average feeding distance from the road was farther than small flocks of cranes in both species. Cranes showed the reaction, such as alert, walking, running and flying against the vehicle stop and were more sensitive as they were close to the road. The reacting time to the stopping vehicle were reduced as it was farther from the road. The distance of about 250m was a reaction threshold distance against the vehicle stop to both species. The reacting time in the same distance was not different in relation to the traffic volume, but large traffic volume tended to cause cranes to stay far away from the road and not to feed themselves near a traffic congested area. The reason cranes fed themselves on fallen rice grains in spite of the vehicular traffic interruption factor was that there was a high density of the fallen rice grains remaining at the area near a road.

• Journal of the Korean Institute of Gas
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• v.20 no.5
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• pp.64-71
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• 2016

According to the urban gas business law, electrical corrosion prevention measures shall be installed to the buried gas pipelines and the pipe-to-soil potentials should be measured at the test box at least once a year. Most of the test boxes installed in urban area are usually located on the road where the vehicle travels, therefore, it is difficult to measure the CP potentials at the test boxes. That is, we need traffic control when carrying out the measurement of the CP potentials on daytime when the traffic is heavy, or we have to measure the potentials in the late night when the traffic is light. To solve these difficulties, we have studied remotely CP potential measuring method by using the patrol car. We have installed solid reference electrodes and data loggers under the test boxes on the site and received the CP potentials from the data loggers when the vehicle moves. It was difficult to send and receive the data because the data logger was located under the ground. We have applied 3 different method including 2 antenna systems to achieve best effective way in receiving the data. We have found the remote CP measuring method by using a car can save more 20 times of measuring time than conventional measuring methods.

• The Journal of the Korea Contents Association
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• v.17 no.6
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• pp.643-649
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• 2017

This research is to compare factors which influence to mobilize police force necessary for crowd gathering occasions, and the purpose of this research is to prepare scientific basis for mobilization of police force by understanding order of priority of obstructive factors to mobilize police force for progressing safe crowd gathering occasions. Crowd gathering occasion has a characteristic that minor cause can lead to huge damage because many people concentrically gather at a specific place. In order to control these risks, it is necessary to analyze criteria on order of priority which can arouse risk to mobilize police force. In this research, I classified the factors influencing safety of crowd gathering occasion as internal risk factor, external risk factor and traffic safety threatening and set up the level of private security manpower and participants mobilized to crowd gathering occasion as independent variable and set up mobilized police force from 2013 to 2014 as dependent variable and analyzed it hierarchical analysis. From the result of analysis, the biggest influence to mobilization of police force for crown gathering occasion was the number of participants, and next self order-keeping agents and reason of mobilizing police force. Based on the result of analysis that the biggest factor to mobilize police force to crowd gathering occasion is the number of participants, it can be resulted that the number of participants influence to the risk of crowd gathering occasion.

• Korean Security Journal
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• no.50
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• pp.91-115
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• 2017

Recently the characteristics of those who committed serious terrorist crimes are not directly related to the direct command system of a specific terrorist organization (ex. IS) but are influenced by the political propaganda of terrorist organizations online, Terrorist crime under the loose form of the terrorist organization. Therefore, this study suggests ways to improve countermeasures against terrorism in metropolitan subways. Although it is important for the prevention of terrorism in the subway, it is important for the police officers of the subway police and the special police officers of the railway to have a physical limit to take charge of them, and after confirming that improvement measures are necessary, And pointed out the possibility of establishing independent security departments where judicial and administrative control is not feasible to grant police rights. In addition, I pointed out how to improve the safety of subways in the metropolitan area through the recruitment of core job candidates and the identity survey during the subway operation. Furthermore, it was confirmed that a special council on terrorism, which can take into consideration the characteristics of subway terrorism, such as airports and ports, is required to be established in charge of terrorism prevention under the current Anti-Terrorism Act. Finally, it is once again emphasized that the strengthening of the powers of the counterparts to terrorism must inevitably limit the basic rights of the people, so the principle of proportionality must be observed in their activities.

• Journal of Intelligence and Information Systems
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• v.11 no.3
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• pp.25-43
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• 2005

In modern automated container terminals, automated guided vehicle (AGV) systems are considered a viable option for the horizontal tansportation of containers between the stacking yard and the quayside cranes. AGVs in a container terminal move rather freely and do not follow fixed guide paths. For an efficient operation of such AGVs, however, a sophisticated traffic management system is required. Although the flexible routing scheme allows us to find the shortest possible routes for each of the AGVs, it may incur many coincidental encounters and path intersections of the AGVs, leading to collisions or deadlocks. However, the computational cost of perfect prediction and avoidance of deadlocks is prohibitively expensive for a real time application. In this paper, we propose a traffic control method that predicts and avoids some simple, but at the same time the most frequently occurring, cases of deadlocks between two AGVs. More complicated deadlock situations are not predicted ahead of time but detected and resolved after they occur. Our method is computationally cheap and readily applicable to real time applications. The efficiency and effectiveness of our proposed methods have been validated by simulation.

• KDI Journal of Economic Policy
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• v.13 no.2
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• pp.129-140
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• 1991

The primary purpose of price regulation on public utilities and other public services is not to prevent them from rising and control inflation but to allocate resources efficiently and reflect social values, when market does not function perfectly. That is, price regulation by government is a policy tool which is aimed at microeconomic effects. Therefore, when a microeconomic policy tool is used for macroeconomic policy objectives, such as price stabilization, we can have problems stemming from the mismatch. One of the examples is distortions in the relative price structure of resources. As government suppresses increases in regulated prices in an effort to reduce inflationary pressures, some of the public services become relatively cheaper, resulting in excess use of those services under regulation. Also, inflexibility of adjusting regulated prices to the overall price changes results in deterioration of qualities of public services. This paper proposes a set of reform proposals which are itnended to minimize such government failures. It is argued that the authority of price regulation should be decentralized, and ultimately done by independent regulatory commissions for each service. The pricing should be based on the principle of separate and independent accounting by each service unit and the principle of beneficiaries bearing the costs of services.

• Korean Journal of Poultry Science
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• v.11 no.1
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• pp.49-64
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• 1984

During the 1978-79 Newcastle disease (ND) epizootic period, a detailed survey was conducted on the five representative farms which had been following one of the recommended vaccination programs. When the disease broke out during laying period, clinical symptoms were mild to moderate respiratory distress and greenish diarrhea. Affected flocks experienced weekly mortality from less than 1% to 17%. Egg production returned to normal 18 to 36 days after the initial signs appeared although some flocks never returned to normal. On postmortem examination,, most affected chickens showed severe hemorrhagic lesions in the duodenum, hematoma on ova, and heavy fat accmulation on various visceral organs. Most of the NO affected flocks had geometric mean hemagglutination inhibition antibody(HIA) titers of 7 log$_2$ or higher two to three weeks after the appearance of clinical signs. These HIA titers were at least 16-fold higher than those before infection. Flock mean HIA titers before infection were usually lower than 3 log$_2$. Severity of clinical signs and anamnestic antibody response were maximum in the flocks whose vaccination immunity was insufficient or waned considerably. Observations showed that even young birds, if properly vaccinated, could get effective protection from field ND exposure.

• Journal of Korean Home Economics Education Association
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• v.19 no.3
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• pp.19-36
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• 2007

The purpose of this study is to identify the consumer roles-gainer, allocator, buyer, user and disposer- of middle school students. The methodology that has been applied to this study was an ethnography study based on in-depth interviews with ten middle schoolers selected in Changwon, Gyeongnam. The result of this study is as follows; First, as gainers, teenagers usually gained their money from their parents. Because this tends to be not periodical, allowance education should be performed to both parents and teenagers. Second, as allocators, teenagers allocated most of their money in entertaining, shopping, traveling, leaving small amount of money for saving. Thorough education supported by school and home should be held for efficient and balanced allocation of acquired allowance. Third, teenagers as buyer should be encouraged to examine carefully in their buying goods and services thus increasing their ability in solving problems related to consume. Fourth, due to the fact that teenagers' role as user is very feeble, educations related to usually consumed products and consuming environments should be strengthened. Fifth, N generation's internet-based character is reflected in disposer rules so education for better disposal in internet world should be needed. Conclusively, education for teenagers' role as consumer will be efficient is linked with school, home, and society thus providing better standard for consumers.