• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.4
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• pp.897-905
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• 2015

This research suggested the traffic signal calculation model of active transit signal priority using a shockwave model. Using this signal priority timing optimization model, the shockwave area is computed under the condition of Early Green and Green Extension among active transit signal priority techniques. This study suggested the speed estimation method of backward shockwave using average travel time and intersection passing time. A shockwave area change is calculated according to signal timing change of transit signal priority. Moreover, this signal timing calculation model could determine the optimal signal priority timings to minimize intersection delay of general vehicles. A micro simulation analysis using VISSIM and its user application model ComInterface was applied. This study checked that this model could calculate the signal timings to minimize intersection delay considering saturation condition of traffic flow. In case studies using an isolated intersection, this study checked that this model could improve general vehicle delay of more over ten percentage as compared with equality reduction strategy of non-priority phases. Recently, transit priority facilities are spreading such as tram, BRT and median bus lane in Korea. This research has an important significance in that the proposed priority model is a new methodology that improve operation efficiency of signal intersection.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.3
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• pp.439-448
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• 2018

Conventional Earthquake Early Warning System (EEWS) detects the propagated P-wave from epicenter which should be achieved within 5 seconds to provide seconds to minutes of warning, allowing people to prepare for protective actions. EEWS in Korea is currently capable of providing a warning within 50 seconds after the primary P-wave detection, however, it is well-known that earthquake warning systems operating around Korean National Parks (KNP) have limited capability to fully monitor earthquake events. This study, therefore, presents a strategy to quantify the potential vulnerability to earthquake hazards by superimposing the distribution of Korea Integrated Seismic System (KISS) and the discretized map of KNP. Total 22 national parks are evaluated, and the results suggest that the improvement of the on-site systems should be necessitated for Gyoengju, Gyeryongsan, Songnisan, Gayasan, and Deogyusan national parks, whereas enhancement of regional systems is required for Bukhansan national park.

• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.3
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• pp.149-155
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• 2020

Cattle feeding in South Korea has been heavily dependent on domestically produced rice straw and imported grain. Around 42% of domestically produced rice straw is utilized for forage, and the remainder is recycled to restore soil fertility. Approximately 35% of round baleages were made with rice straw. However, higher quality hay is desired over rice straw. Due to increasing stockpiles of rice, there has been an economic burden on the government to store the surplus; therefore production of annual forage crops in rice fields has been further promoted in recent years. Hay import from the USA currently constitutes more than 80% of total imported hays. The main imported hays are alfalfa (Medicago sativa), timothy (Phleum pretense), and tall fescue (Festica arundinacea). The estimated forage required for cattle feeding was approximately 5.4 million MT in 2016. Domestically produced forage sates only 43% of that value, while low quality rice straw and imported hay covered the rest of demand by 33% and 20%, respectively. As utilization of domestically produced forage is more desirable for forage-based cattle production, long-term strategies have been necessary to promote domestic production of high quality baleage. One such strategy has been utilizing the fertile soil and abundance of fallow rice fields of western region of S. Korea to produce forage crops. Italian ryegrass (Lolium multiflorum) is the most successfully produced winter annual in the region and is approximately 56% of the total winter annual forage production. Forage sorghums (Sorghum bicolor), sorghum × sudangrass hybrids, and hybrid corn (Zea mays) produce a substantial amount of warm-season forage during summer. Produced forage has been largely stored through baleage due to heavy dew and frequent rains and has been evaluated according to S. Korea's newly implemented baleage commodity evaluation system. The system weighs 50% of its total grading points on moisture content because of its importance in deliverable DM content and desirable baleage fermentation; this has proved to be an effective method. Although further improvement is required for the future of forage production in South Korea, the current government-led forage production in rice fields has been able to alleviate some of the country's shortage for quality hay.

• Journal of Life Science
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• v.24 no.2
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• pp.196-208
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• 2014

During the life cycle of plants, water deficit leads to an adverse effect on its growth and development. To increase the productivity of crops, overcoming such drought stress is one of the most important issues in the field of plant study. Among plant hormones, the phytohormone, abscisic acid (ABA) plays a crucial role in eliciting resistance to drought stress as well as in multiple developmental processes, such as seed germination, stomatal closure, and seedling growth. Therefore, further understanding of the ABA-mediated signal transduction pathway in plants is an effective strategy to generate drought-tolerant plants. Posttranslational modification, such as phosphorylation and ubiquitination, is an efficient mechanism for plants to acquire quick adaptation against environmental stress conditions since this process directly affects pre-existing signaling components by modulating protein activity and stability. Here, recent reports on ABA signaling are reviewed, especially focusing on ABA transport, perception, signaling, and posttranslational modification in ABA-mediated cellular responses. Also, we present future prospects on how the control of such a mechanism can be applied to generate useful agricultural crops.

• Korean journal of communication and information
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• v.52
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• pp.177-202
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• 2010

IPTV has been drawing attention as a representative convergence media. The analysis of the convergence media, as like IPTV, requires an investigation into the use perception and multidimensional factors. So this research examines the IPTV usage, based on the Technology Acceptance Model. The analysis was made with the 500 users, based on the online survey. The first results is concerned with the user characteristics. A positive influential relationship between the user characteristics and use perception was confirmed, along with the individual attribute and environmental influence. The second, 'perceived ease of use' was found to positively influence 'perceived usefulness' and 'perceived playfulness'. This finding suggests that it is an important diffusion strategy to enhance the ease of use of IPTV. The third is the emphasis of playfulness of IPTV. Since IPTV is multimedia, playfulness played a significant role in diffusing IPTV. The application of the TAM to the media analysis of IPTV, which reflects the environments of the convergence media and use perception, was successful in drawing a significant outcome.

• Journal of the Korea Convergence Society
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• v.6 no.4
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• pp.139-146
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• 2015

WSN has been utilized in various directions from basic infrastructure of environment composition to business models including corporate inventory, production and distribution management. However, as energy organizations' private information, which should be protected safely, has been integrated with ICT such as WSN to be informatization, it is placed at potential risk of leaking out with ease. Accordingly, it is time to need secure sensor node deployment strategies for stable enterprise business. Establishment of fragmentary security enhancement strategies without considering energy organizations' security status has a great effect on energy organizations' business sustainability in the event of a security accident. However, most of the existing security level evaluation models for diagnosing energy organizations' security use technology-centered measurement methods, and there are very insufficient studies on managerial and environmental factors. Therefore, this study would like to diagnose energy organizations' security and to look into how to accordingly establish strategies for planning secure sensor node deployment strategies.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.3
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• pp.52-62
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• 2008

By analyzing specific plant distributions and physicochemical characteristics of topsoil in a reclaimed dredging area, baseline data was found of natural landscape planting sites, and developing dredged fill ground. The reclaimed dredging area is five different stands (1, 2, 3, 4 and 5) which were examined in this research. They are located from sea level to 15 meters in altitude and exhibited typical characteristics of the salt marsh in Gwangyang Bay. Species with high constancy in the vegetation on the reclaimed soil were classified into four stages. A total of 12, 15, 22, 27 and 35 different plant species were found and also increased in stands 1, 2, 3, 4 and 5, respectively. Moving from stand 1 to 5, halophytes decreased and non-halophytes increased. Desalination at each stage of the reclaimed dredging area was a driving force affecting the performance and distribution of halophytes and non-halophytes. Overall, 35 quadrats of soil were selected and analyzed for specific physicochemical characteristics of topsoil between O${\sim}$20cm. Results of the physicochemical analysis such as altitude, slope, vegetation and kind of reclaimed dredging soil, exhibited irregular increases or decreases. As survey areas moved from stand 1 to 4, desalination areas, soil acidity, electric conductions, content of salinity, available phosphorus, potassium, chlorine, calcium, and magnesium indicated decreasing patterns; however, total nitrogen, silt, and clay content increased. Cluster analysis and PCA by environmental data within the stands clearly showed five distinct vegetation patterns on the tested reclaimed area. These results indicate that the differences of performance and distribution of vegetation are due to the SAR in the reclaimed soil and related to the natural survival strategy at the given hostile habitat.

• Journal of Korean Society of Forest Science
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• v.98 no.3
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• pp.263-271
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• 2009

This study aims to identify negotiation alternatives related to Post-2012 reducing emissions from deforestation (RED) and enhancement of forest carbon stock (EFCS) activities. It also aims to recommend a negotiation strategy considering environmental integrity and national interest on the basis of estimating reduction potentials of each alternative on the assumption that tradable carbon credits play an important role as positive incentives. In order to estimate greenhouse gas (GHG) reduction potentials and income potential from RED and EFCS activities, 99 countries were selected by the Global Forest Resources Assessment of the Food and Agriculture Organization of the United Nations. A 'baseline and credit' method was applied to estimate RED activities. Gross-net and net-net methods were applied for EFCS activities. According to the results, Brazil, Indonesia, and the Democratic Republic of Congo have more potential to get positive incentives through RED, while China, Chile, and the Republic of Korea have more potential to get positive incentives through EFCS. This study suggests including both RED and EFCS activities in the boundary of policy approaches and endowment of positive incentives to consider GHG reduction potentials in the global scale and equity among developing countries. Making a discount rate application of forest management activities can be also recommended to factor out the effects of human-induced activities by EFCS activities.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3815-3823
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• 2009

As a critical element for success of community based tourism, festivals and special events play a significant role in enticing visitors from outside of the host community. More importantly, festivals and events contribute to improve the life quality for both hosts and guests. The purpose of this study is to develop a market segmentation strategy based on the perceived festival impacts among visitors to Poonggi Ginseng Festival so that each segment can be treated and communicated with separatedly for utmost visiting satisfaction. In this study, two market segments based on visitors' socio-cultural and environmental evaluation of the festival were identified, namely high appraisal group and low appraisal group. Two groups contrast sharply in terms of their behavioral patterns and perceived value and overall satisfaction. Practical marketing strategies are suggested accordingly.

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.1
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• pp.13-18
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• 2014

Sensor nodes are used for monitoring and collecting the environmental data via wireless sensor network. The wireless sensor network with various sensor nodes draws attention as a key technology in ubiquitous computing. Sensor nodes has very small memory capacity and limited power resource. Thus, it is essential to have energy efficient strategy for the sensor nodes. Since the sensor nodes are operating on the same frequency bands with ISM frequency bands, the interference by the devices operating on the ISM band degrades the quality of communication integrity. In this paper, the convolutional code is proposed instead of ARQ for the error control for the sensor network. The proposed convolutional code was implemented and the BER performance is measured. For the fixed transmitting powers of -19.2 dBm and -25dBm, the BER with various communication distances are measured. The packet loss rate and the retransmission rate are calculated from the measured BER. It is shown that the porposed method obtained about 9~12% and 12-19% reduction in retransmission rate for -19.2 dBm and -25 dBm respectively.