• Journal of Broadcast Engineering
• /
• v.19 no.6
• /
• pp.767-788
• /
• 2014

The worldwide transition from analog to digital broadcasting has now been completed and the need to study next generation standards for Ultra High Definition TV (UHDTV) broadcasting, and broadcasting & communication convergence systems is rapidly growing. In particular, high resolution mobile broadcasting services are needed to satisfy recent consumers. Therefore, the development of highly efficient convergence broadcasting systems that provide fixed/mobile broadcasting through a single channel is needed. In this paper, a service scenario and requirements for providing 4K UHD & HD convergence broadcasting services through a terrestrial single channel are analyzed by employing the latest transmission and A/V codec technologies. Optimized transmission parameters for 6 MHz & 8 MHz terrestrial bandwidths are drawn, and receiving performances are measured under Additive White Gaussian Noise (AWGN) and time-varying multipath channels. From the results, in a 6 MHz bandwidth, the reliable receiving of HD layer data can be achieved when the receiver velocity is maximum 140 Km/h and is not achieved when the velocity is over 140 Km/h due to the limit of bandwidth. When the bandwidth is extended to 8 MHz, the reliable receiving of both 4K UHD and HD layer data is achieved under a very fast fading multipath channel.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.31 no.6_1
• /
• pp.431-437
• /
• 2013

Landslides are caused by earthquakes or heavy rains. Recently the incidence of landslides has been increased. However, it is impossible to predict the occurrence of landslide exactly. The purpose of this research is that subdivide the classes of elements in the landslide management system by using spatial analysis technique and AHP method. The existing landslide management system is only comprised of weighted value the slope elements without weighted value about the slop direction elements. For the accuracy improvement in landslide occurrence point, weighted value about the slope direction should be considered. This research is focused on segmentation in slope direction three categories. If the direction of landslide does not affect the structure, I do not think the subject is worth considerating. Based on these results will discuss the improvements in Landslides management systems. Analysis results, segmentation on the slope and the slope direction are needed. Segmented categories about topography elements will be increase the accuracy of landslides management system. Also, since topography of the elements is only considered, segmentation of different elements is needed.

• Journal of Korea Port Economic Association
• /
• v.26 no.3
• /
• pp.221-239
• /
• 2010

This study aims to provide solutions concerned with to residential moving companies about their operational problems. In order to shed light on these problem, factor analysis and fuzzy AHP method are adopted. Selected factors are low quality of workers and equipments, weak condition of business, policy and form of a contract, and excessive competition. The results of survey show that excessive competition is the most urgent problem compared with other problems. In the twelve-measured variables, The problem of non-certificated firms, low service quality caused by excessive competition, and claims caused by lack of service instruction are chosen as the urgent matters. As a result of the analyses, the study would propose policy directions how to solve these problems. Firstly, the government should make the legal basis of operating the industry because there is too competitive in the field. Secondly, the government should regulate firms which have not a certificate because they are the cause of low service quality in the field. Thirdly, in order to improve the service quality, the study would suggest that the managers should instruct the workers of residential moving companies. Lastly, the paper would suggest that customers check the certificate of the firm allowed by the government authorities.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.4D
• /
• pp.361-368
• /
• 2010

It is general that mostly congested sections of national backbone networks have been improved based on the national network expansion plan. However, in case of intermodal terminals which are origins of logistics, it is still so congested that travel time between origin and destination is long. Therefore, intermodal transportation systems plan of major intermodal terminals for the intermodal connector networks between intermodal terminal and national backbone network or intermodal terminal was established. With the limitation of priority methodology applying to intermodal connector facility under existing methodology, this study suggests an improved priority methodology. This study includes characteristics of terminal on the hierarchical structure and assessment list, but it does not concentrate on the specific terminal type through survey. To avoid a certain concentration, budget constraint for each terminal type was considered ahead of priority. Finally priority methodology was developed with two-step assessment under consideration that specific terminal is not involved in intermodal connector facility project. As a result of calculating weights by survey, effects such as d/c and accessibility fluctuations index through project implementation gain high weight, and degree of region underdevelopment gets next. Although the methodology in this study could not yields the priority by assessment list, it will be useful for setting the direction on policy related to intermodal connector facility projects.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.8
• /
• pp.1182-1189
• /
• 2012

The purpose of this study was to analyze university student' perception of the price of coffee shops using price sensitivity measurements. The questionnaires were distributed to 640 university students in Changwon, Korea from March 13 to April 8, 2011. A total 571 were used for the final analysis, which excluded improperly-completed questionnaires. The results of this study were as follows. Indifference prices (IDPs) were \2,200 for on-campus coffee shops and \2,850 for off-campus coffee shops. The optimum price points (OPP) were \2,300 for on-campus coffee shops and \2,850 for off-campus coffee shops. The price stress range (PSR) was \100 (\2,200~2,300) for on-campus coffee shops and \0 (\2,850~2,850) for off-campus coffee shops. The point of marginal cheapness (PMC) was \1,100 for on-campus coffee shops and \1,500 for off-campus coffee shops, whereas the point of marginal expensiveness (PME) was \3,600 for on-campus coffee shops and \4,100 for off-campus coffee shops. The ranges of acceptable prices (RAP) were \2,500 (\1,100~3,600) for on-campus coffee shops and \2,600 (\1,500~4,100) for off-campus coffee shops. On the basis of IDP percentage, university students were more sensitive to off-campus coffee shops than on-campus coffee shops. In contrast, on the basis of PSR and RAP, university students were more sensitive to on-campus coffee shops than off-campus coffee shops. Therefore, the price increase for an americano should be recommended to be from \1,100 to \3,600 for on-campus coffee shops and from \1,500 to \4,100 for off-campus coffee shops. The manager of on-campus coffee shops should be careful when increasing the prices, and the manager of off-campus coffee shops should make it possible for customers to perceive service quality.

• Journal of Wetlands Research
• /
• v.16 no.2
• /
• pp.235-243
• /
• 2014

According to the "Safety Evaluation Detailed Instructions (Dam)", precise safety inspection is carried out for dams that exceed a certain scale. However, as the Hydrological Safety Evaluation from various evaluation standards is designed to evaluate the safety of existing dams considering PMF, the evaluation is much less applicable for most agricultural reservoirs. Therefore, the Hydrological Safety Guidelines for agricultural reservoirs are expected to be re-evaluated considering the diverse risk factors with the coefficient model and AHP in this study. The coefficient model has been developed by selecting the hydrological safety superordinate subordinate evaluation factors to reflect diverse risk factors of agricultural reservoirs. After calculating the sum of indicators score for each evaluation factors, validation procedures were performed for the questionnaire which a panel answered. The practical coefficient has eventually been estimated for the hydrological safety evaluation considering the diverse risk factors. The conclusions acquired based on the study done are that both most agricultural reservoirs were classified as flood defense capability is insufficient and agricultural reservoirs which meet embankment-freeboard standards considering PMF was overestimated.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2006.06b
• /
• pp.265-271
• /
• 2006

According to globalization of world economy by extension of production, sales and distribution all around the world and international transportation system changed into a transport system that puts great importance on speediness and value-added services, international transport system is changing into a Multimodal Transport Routing centered system that systematically connects marine, air and rail transports. Due to such changes production, sales and distribution must be provided in time and Multimodal Transport Routing, which can provide multi-dimensional logistics services to customers of global network, is needed but information connection for international transport and connection system between transport modes are insufficient and can not be activated. Especially in Korea, selection standard of 3rd party logistics companies and transport companies is presented, but logistics exclusive companies, which plan and execute the transportation, can't present a systematic evaluation standard for international Multimodal Transport Routing, selection. Thus, this research surveys important previous studies about Multimodal Transport Routing, selection, derives an evaluation standard for Multimodal Transport Routing, selection through interview with company officials, and presents a theoretical basis for Multimodal Transport Routing, selection through systematic analysis of Multimodal Transport Routing, selection using Analytical Hierarchy Process (AHP).

• Journal of Wetlands Research
• /
• v.17 no.2
• /
• pp.130-138
• /
• 2015

According to the "Safety Evaluation Detailed Instructions (Dam)", a precise safety inspection is carried out for dams that exceed a certain scale. However, as the Hydrological Safety Evaluation from various evaluation standards is designed to evaluate the safety of existing dams considering PMF(Probable Maximum Flood), the evaluation is much less applicable for most agricultural reservoirs. Therefore, the Hydrological Safety Guidelines for agricultural reservoirs are expected to be re-evaluated considering the diverse risk factors with the coefficient model and AHP(Analytic Hierarchy Process) in this study. The coefficient model has been developed by selecting the hydrological safety superordinate subordinate evaluation factors to reflect diverse risk factors of agricultural reservoirs. This study indicated that in the short term, improving the safety check condition evaluation grade will be useful to improve the hydrological safety of the agricultural reservoir because it can be performed immediately.

• Journal of the Economic Geographical Society of Korea
• /
• v.21 no.2
• /
• pp.156-172
• /
• 2018

Recently, Korea suffered serious social conflicts between generations due to population aging. Anxiety about depletion of the National Pension Fund is one of the social problem to young generation, because of the uncertainty that they will not able to receive the pension they paid. At the same time, due to the high housing rent in Seoul metropolitan area, the demand for housing welfare and supply of public rental housing for young generation was increased. There are some opinions about using National Pension Fund to supplying public rental houses in the society. In this research, we were concentrated on finding the suitable areas for the public rental house using National Pension Fund. First, verifying the validity of the investment using National Pension Fund for the public rental housing was done. And spatial statistical methods were applied to explore the suitable areas for the public rental housing in Seoul metro area. Finally, this study divided young people into three groups and analyzed ways to supply public rental housing for each group in proper areas by their demand. This research's ultimate goals are mitigating the conflicts between the generations and achieving both profitability and publicness of National Pension Fund.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.53 no.5
• /
• pp.25-36
• /
• 2016

The goal of the SmartGrid is to maximize energy efficiency by exchanging bi-directional real-time power information with the help of ICT(Information and Communication Technology). In this paper, we propose a "JRS-MS" (Joint Routing and Scheduling for Multi-channel SmartGrid) algorithm that uses numerical modeling methods in IEEE 802.11s based STDMA multi-channel SmartGrid NAN networks. The proposed algorithm controls the amount of data transmission adaptively at the link layer and finds a high data-rate path which has the least interference between traffic flows in multi-channel SmartGrid NAN networks. The proposed algorithm improve transmission performance by enhancing network utilization. By comparing the results of performance analysis between the proposed algorithm and the JRS-SG algorithm in the previous paper, we showed that the JRS-MS algorithm can improve transmission performance by maximally utilizing given network resources when the number of flows are increasing in the multi-hop NAN wireless mesh networks.