• Journal of the Korean Society of Child Welfare
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• no.32
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• pp.7-32
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• 2010

The purpose of this research is to identify the longitudinal reciprocal relationship between family social capital and self-esteem of adolescents. Five waves of panel data from the Korea Youth Panel Survey were employed for this research. Korean Adolescents Policy Research Institute collected the first wave data in 2004 from elementary school children in 4th grade. Autoregressive cross-lagged modeling was performed to analysis the longitudinal reciprocal relationship between family social capital and self-esteem. The major findings were as follows. First, stability coefficient of family social capital and self-esteem showed that both variables were significantly stable over time. Secondly family social capital(t) had statistically significant effect on self-esteem(t+1), whereas self-esteem did not predict family social capital at a statistically significant level. These findings suggest that family social capital and self-esteem is stable overtime, and that obtaining family social capital and establishing positive self-esteem is important during this period in childhood. In addition, the results show that family social capital affects self-esteem, which highlights the importance of family social capital accumulation on the development of adolescent self-esteem.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.273-286
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• 2013

Recently, due to problems with subway and bus operations, a need has emerged for a solution such as the introduction of an Advanced Transit System. In several municipalities, systems have been introduced using light rail as AGT urban aesthetics construction. There is high inhibition and civil cases are delayed by more environmentally friendly and accessible remedies. For the purpose of this study, Changwon city would be transformed to have an environmentally friendly transportation system such as a tram with an overview. Features, advantages, and disadvantages are analyzed, and systems are established the existing public transport routes by transfer system. Changwon city's tram plan is first step in open in year 2018, and second step with the opening goal of the year 2021, and the total line length of 33.9 km, the station will be built in the 38 locations. and also in 2011 a feasibility study, evaluated a low economic as B/C to 0.88, but it evaluated the high value of the policy analysis as AHP to 0.502. However, introduction of a tram project that should precede the as following condition. The first step in Changwon city's tram plan would be as follows : The introduction of the tram system would demand traffic management along with a restructuring of the bus system, and the tram system would be selected for domestic realities. Secondly, the introduction of trams would comprehend the advanced traffic composition in accordance with the consensus of the citizenship, and a legal system should be established for the introduction of the trams.

• The Korean Journal of Air & Space Law and Policy
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• v.18
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• pp.41-64
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• 2003

This paper describes the liability regime of the air carrier under the Montreal Convention of 1999 for the international cargo, comparing to those of the existing Warsaw system. Also this paper deals with main issues of the Montreal Convention which are relevent for the carrier's liability in the carriage of the air cargo. The Warsaw Convention was adopted in 1929 and modified successively in 1955, 1961, 1971, 1975, and 1999. The Montreal Convention of 1999 modernized and consolidated the Warsaw Convention and related instruments. The air carrier is liable by application of principle of strict liability as stated in the Montreal Convention : The carrier is liable for the destruction or loss of, or damage to cargo and delay during the carriage by air, and the carrier's liability is limited to a sum of 17 Special Drawing Rights per kilogramme. However, the Montreal Convention has some outstanding issues with respect to the liability of the air carrier : potential conflicts between the Montreal Convention and the Warsaw Convention, the amounts of limits of the carrier's liability, the duration of the carrier's liability, the exessive litigation, and the aviation insurance. Therefore, the conditions and limits of the carrier's liability under the Montreal Convention should be readjusted and regulated in detail.

• The Korean Journal of Air & Space Law and Policy
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• v.35 no.3
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• pp.39-63
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• 2020

This paper reviews the Interpretative Guidelines on EU passenger rights regulations in the context of the developing situation with COVID-19 of EU commission. To enlighten the obscurity and to mitigate the economic impacts of the COVID-19, European Commission has published "Interpretative Guidelines on EU passenger rights regulations in the context of the developing situation with Covid-19" on March 18, 2020. The Guideline essentially aims to create a coherent system of rules to assist the passengers, industry and national authorities overall under the unprecedented circumstances across the European Union. To do so, the Guideline is drafted to cover the rights of passengers travelling by air, rail, ship or bus/coach, maritime and inland waterways, as well as the corresponding obligations for carriers. From an aviation industry focused perspective, by referencing the Regulation (EC) numbered 261/2004, the Guideline specifically applies to cancellation and delay in flights which are seen as the dark spots for the air carriers concerning potential burdens.

• Journal of Korea Spatial Information System Society
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• v.8 no.2 s.17
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• pp.53-73
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• 2006

Recently, the need for Location-Based Services (LBS) has increased due to the development of mobile devices, such as PDAs, cellular phones and GPS. As a moving object database that stores and manages the positions of moving objects is the core technology of LBS, the scheme for maintaining the main memory DBMS to the server is necessary to store and process frequent reported positions of moving objects efficiently. However, previous works on a moving object database have studied mostly a disk based moving object index that is not guaranteed to work efficiently in the main memory DBMS because these indexes did not consider characteristics of the main memory. It is necessary to study the main memory index scheme for a moving object database. In this paper, we propose the main memory index scheme based on the R-tree for storing and processing positions of moving objects efficiently in the main memory DBMS. The proposed index scheme, which uses a growing node structure, prevents the splitting cost from increasing by delaying the node splitting when a node overflows. The proposed scheme also improves the search performance by using a MergeAndSplit policy for reducing overlaps between nodes and a LargeDomainNodeSplit policy for reducing a ratio of a domain size occupied by node's MBRs. Our experiments show that the proposed index scheme outperforms the existing index scheme on the maximum 30% for range queries.

• Journal of the Korea Convergence Society
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• v.9 no.9
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• pp.285-292
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• 2018

The purpose of this study is to analyze the association of smoking cessation attempts and the perceived stress level and to identify the factors affecting the perceived stress level of quit smoking. The study utilized the 2015 Korean National Health and Nutrition Examination Survey, and was applied an Ordinal Logistic Regression to examine the association of smoking cessation attempts and perceived stress level. The current smoker those who experience failure in smoking cessation, were more stressful than those who experience success in smoking cessation (OR=1.72, CI;1.41-2.08). This study identified smoking cessation failure as a major psychiatric factor associated with high perceived stress level, and suggests high stress after smoking cessation failure as one of the reasons why smokers do not reach complete smoking cessation. Also, in order to promote smoking cessation, it is needed to have political approach in reducing the psychiatric hurdle like high stress after smoking cessation failure.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.3
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• pp.116-126
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• 2015

In a distributed heterogeneous computing system, the performance of a parallel application greatly depends on its task scheduling algorithm. Therefore, in order to improve the performance, it is essential to consider some factors that can have effect on the performance of the parallel application in a given environment. One of the most important factors that affects the total execution time is a critical path. In this paper, we propose the CLTS algorithm for a task scheduling. The CLTS sets the priorities of all nodes to improve overall performance by applying leveling method to improve parallelism of task execution and by reducing the delay caused by waiting for execution of critical nodes in priority phase. After that, it conditionally uses insertion based policy or duplication based policy in processor allocation phase to reduce total schedule time. To evaluate the performance of the CLTS, we compared the CLTS with the DCPD and the HCPFD in our simulation. The results of the simulations show that the CLTS is better than the HCPFD by 7.29% and the DCPD by 8.93%. with respect to the average SLR, and also better than the HCPFD by 9.21% and the DCPD by 7.66% with respect to the average speedup.

• Journal of the Korea Society for Simulation
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• v.24 no.2
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• pp.31-39
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• 2015

Unemployment is related to social issues as well as personal economics activity so various policies have been made to reduce the unemployment rate in many countries. Because of delay inherent in the survey mechanism to collect unemployment data, it takes lots of time to acquire survey unemployment data. To develop proper policies for reducing unemployment rate at the right time, it is quite critical to obtain faster and more accurate information concerning about unemployment level. To remedy this problem, recently an advanced analytics utilizing internet queries is suggested. To examine the potential of Web query information, this research investigates the usefulness of internet activity data to predict Korean unemployment rate. One of selected web-query data(unemployment claim) has a quite strong correlation with unemployment rate. This research employes a time series approach of the ARIMA model that utilizes the information of keyword queries provided by the Naver(Korean representative portal site) trend together with unemployment rate data provisioned from Statistics Korea. With respect to model selection guidelines of mean squared error and prediction error, the model with utilizing the web query information shows better results than the model without such information. This suggests that there is a strong potential for the used method, which needs to be further explored.

• Journal of Digital Convergence
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• v.12 no.10
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• pp.317-327
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• 2014

To improve the efficiency of wireless channel, IEEE 802.11ac uses the DL MU-MIMO MAC scheme through which an AP transmits multiple frames to different mobile nodes simultaneously. IEEE 802.11ac DL MU-MIMO MAC needs a new step, called as TXOP sharing, between legacy IEEE 802.11n DL SU-MIMO's two operations, the obtaining an EDCA TXOP and the transmitting multiple frames for EDCA TXOP. In the TXOP sharing operation, both wireless channel destinations and frames transmitted for its TXOP period should are determined. So this paper deals with the TXOP sharing for improving IEEE 802.11ac MAC performance. However, the EDCA priority based method mentioned by IEEE 802.11ac standard document not fair among the buffers and the frames of buffers, and occurs in high_loss rate and high_delay about specific buffers. In this paper, we propose a new scheme of the TXOP sharing with sequencing p-AC, s-AC in similar properties, and all S-AC. This method provides a differentiated service without damage of EDCA characteristics.

• Journal of the Korea Society of Computer and Information
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• v.15 no.5
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• pp.113-124
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• 2010

In this study, the hybrid authorization quotation technique is based on the device ID for the integrity of the source region guarantee of user certificate, in order to improve the convenience and security for user in the hybrid PKI certificate Mechanism for authentication. The feature of the model in which it is presented from this paper is 5. First, because the user can select the policy himself in which it matches with each authentication situation and security level, the convenience can be improved. Second, the integrity of the source region of the user certificate can be guaranteed through the comparison of the DLDI Key, that is the hash-value of the device ID. Third, the security can be improved by continuously changing an encoding, and the value of the key in which it decodes through the EOTP Key. Fourth, the index value is added to a certificate, and the storage of a certificate is possible at the Multi-Device. Fifth, since the addi the inan aratus for the integrity of the source region guarantee of a certificate is not needed, the authentication process time can be reduced and the computational load of the certificate server can be reduced also.