• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.12
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• pp.1195-1207
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• 2012

Fast and reliable message broadcasting is critical for safety critical applications of VANET due to the urgency and/or significance of the messages for passengers and drivers. For reliable message delivery, a mechanism for checking the reception of message at the neighboring vehicles and retransmitting it if necessary is required. Especially, in urban environments, where the traffic density tends to be high, mechanisms that minimize control message overhead such as beacon are appropriate in order to minimize the message collisions. Furthermore, broadcast delivery is especially difficult at the intersection due to the road side obstacles such buildings, and hence, a mechanism that enables effective and efficient delivery across intersections is required. In this paper, we propose a beaconless reliable and efficient broadcast approach which specifically taking into account the urban streets. The proposed approach checks the message reception of neighboring vehicles implicitly by taking into account the broadcast of message by next vehicle as the acknowledgement. When retransmissions is necessary around the intersections, vehicles located within the intersection area, where the chance of successful signal propagation toward every branch of the intersection is higher due to less signal attenuation caused by road side obstacles, are to do the retransmissions. Simulation results show that the proposed approach can provide better reliability while consume less resources than the existing approaches.

• Journal of the Korea Concrete Institute
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• v.18 no.4 s.94
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• pp.459-467
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• 2006

Recently, interest grew on the quality of aggregates following the diminution of primary resources from river as to grow construction demand and the low grade of nature sand like sea sand. Following, need is to diversify the supply sources of fine aggregates which are excessively relying on sea sand and urgency is to find as soon as possible aggregate resources that can substitute sea sand. On the other hand, various fine aggregates are utilized to produce concrete in the domestic construction fields. However, few studies have been systematically investigated on the effects of such fine aggregates on concrete properties. Therefore, this study examined the effects of comparatively widely used fine aggregates in the domestic construction fields on the quality of concrete through the analysis of the effects of such fine aggregates on the physical properties of fresh concrete and strength of hardened concrete. Results revealed that crushed sand degraded the fluidity and air entraining of concrete compared to natural aggregates like sea sand and river sand. Especially, the use of crushed sand exhibiting bad grain shape and grade was larger adverse effect on the physical properties of concrete. The type of fine aggregates appeared to have negligible influence on the strength for W/C of 55%, 45% while crushed sand decreased the strength for W/C of 35% compared to natural aggregates. It analyzed that the combination of crushed sand exhibiting bad grain shape and grade with natural aggregates improved the characteristics of fresh concrete and had negligible influence on the strength.

• Journal of Food Hygiene and Safety
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• v.28 no.2
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• pp.99-107
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• 2013

Food contaminants are an emerging issue because food is highly influential to human health. Delphi survey was performed to establish the plan for effective management of food contaminants. Fifty experts from academia, research institute, government and food industries on food safety and policy participated in this study. From open-end questions 161 topics were collected and classified into five areas and 42 topics as the first round. The five areas were 'the integrated management system on food contaminants', 'safety management of food contaminants derived from environment', 'safety management of natural toxins contaminated on foods', 'safety management of hazardous substances produced during food processing' and 'construction of cooperative system and public relationship'. At the second round, after analyzing the replies (30/50 replied) the preliminary order was obtained and it was confirmed at the third round (24/30 replied). We suggest the order of priority for required research area of food contaminants considering the importance and urgency of the research.

• Land and Housing Review
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• v.2 no.2
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• pp.101-109
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• 2011

Recently, the construction of U-City or of U-City service (U-service) in many kinds of urban development projects becomes the general trend. However, as the construction of U-city comes into the spotlight like the trend of the times, various service constructions are being indiscreetly implemented since it's processed focusing on local specialized projects or local landmark project by a local autonomous entity or an institute in charge being off the original purpose of the improvement of living quality of residents and the efficiency of urban management, which causes a number of problems on the process, maintenance, operation and management of those projects. Therefore, this study is to derive the standard pattern of U-service construction through the analysis of patterns and numbers of U-service and problems during the process of construction in domestic U-City construction case district, and is aimed to suggest the reasonable direction of service construction based on this. 11 projects areas in which data related to U-service are available among U-City construction project areas were selected for the subjects of this study, and it's standardized with 228 detailed unit services that were suggested by U-Eco City R&D and with 11 service domains that are regulated in "the Act of ubiquitous city construction etc.", and it is limited to services that were suggested in U-City case area of which design was completed by July, 2010 based on this. The actual state of various U-service construction is analyzed through case studies as well as reviews on the legal and theoretical concept and the method of pattern classification of U-service, the plan for the standardization (pattern classification) of U-service and the plan for the construction body of service and to share the costs are suggested as the plan to construct reasonable U-service based on this for the method and the procedure of this study For the method to construct U-service, the plan to classify the pattern of U-service into the basic service and additional service is suggested, and whether it has the publicity, whether urban infrastructure is included, whether utilities are included, the body of realization, the recipients, the urgency, the importance and the spreading, etc. are suggested for the index to determine the pattern of service. The method to get the executor of a project to construct the basic service, the method to get the executor of a project to construct the most basic service among the group classification of service and to get a private entity and a local autonomous entity to perform additional service in the future, and the method to construct the whole service and to distribute the construction costs were suggested, and the first one that determines the body of construction after dividing U-service into the basic service and the additional service was evaluated to be the most reasonable one. And the plan to solve the problem that the excessive construction costs of U-service are shifted onto the executor of a project through benefit principle, balanced distribution principle and consultation and mediation between the interested parties was suggested for the criteria to share the costs.

• Journal of the Society of Disaster Information
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• v.13 no.2
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• pp.155-162
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• 2017

This study has some issues about the elderly, the disabled, and the vulnerable groups whose economic ability is low even if the disaster or disaster situation is not a big problem for the people. we should emphasize the necessity of disaster preparedness action manual considering the characteristics of disaster vulnerable classes and taking serious risks to them even in the same situation. We also want to conduct research only for people with disabilities who are choosing the same definition of the world among the vulnerable groups. I would like to provide a basis for developing a site action manual for people with disabilities by comparing the cases of Korea and Japan. Therefore, through the cases of Japan and Korea, it is possible to maintain the independence of everyday life during disasters, the communication function in disasters, the method of moving information and mobile information, the function of recognizing emergency response, Action Emphasize the urgency of developing action manuals. From this domestic situation, we will conclude the discussion on the disaster safety and action manual for the disabled.

• Korean Journal of Environmental Agriculture
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• v.31 no.4
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• pp.368-374
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• 2012

BACKGROUND: The urgency of feeding the world's growing population while combating soil pollution, salinization and desertification requires suitable biotechnology not only to improve crop productivity but also to improve soil health through interactions of soil nutrient and soil microorganism. Interest in the utilization of microbial fertilizer has increased. A principle of nature farming is to produce abundant and healthy crops without using chemical fertilizer and pesticides, and without interrupting the natural ecosystem. Beneficial microorganisms may provide supplemental nutrients in the soil, promote crop growth, and enhance plant resistance against pathogenic microorganisms. We mixed beneficial microorganisms such as Bacillus sp. Han-5 with anti-fungal activities, Trichoderma harziaum, Trichoderma longibrachiatum with organic material degrading activity, Actinomycetes bovis with antibiotic production and Pseudomonas sp. with nitrogen fixation. This study was carried out to investigate the mixtures on the soil microflora and soil chemical properties and the effect on the growth of lettuce and cucumber under greenhouse conditions. METHODS AND RESULTS: The microbial mixtures were used with each of organic fertilizer, swine manure and organic+swine manure and compared in regard to changes in soil chemical properties, soil microflora properties and crop growth. At 50 days after the treatment of microorganism mixtures, the pH improved from 5.8 to 6.3, and the EC, $NO_3$-Na and K decreased by 52.4%, 60.5% and 29.3%, respectively. The available $P_2O_5$ and $SiO_2$ increased by 25.9% and 21.2%, respectively. Otherwise, the population density of fluorescent Pseudomonas sp. was accelerated and the growth of vegetables increased. Moreover, the population density of E. coli and Fusarium sp., decreased remarkably. The ratio of bacteria to fungi (B/F) and the ratio of Actinomycetes bovis to fungi (A/F) increased 2.3 (from 272.2 to 624.4) and 1.7 times (from 38.3 to 64), respectively. Furthermore, the growth and yield of cucumber and lettuce significantly increased by the treatment of microorganism mixtures. CONCLUSION(S): These results suggest that the treatment of microorganism mixtures improved the chemical properties and the microflora of soil and the crop growth. Therefore, it is concluded that the microorganism mixtures could be good alternative soil amendments to restore soil nutrients and soil microflora.

• Health Policy and Management
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• v.25 no.2
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• pp.140-148
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• 2015

Vaccination is the most powerful and useful preparation against infectious diseases. However, developing vaccines costs a lot and requires extensive long-term efforts. Therefore, the government should research and develop vaccines with a national-level policy. To greatly enhance the success rate of vaccine development, the policy should be set up considering priorities such as the current status of domestic research, the importance for public health, the urgency of research. The Delphi technique was utilized to draft this survey, through a brainstorming stage, then two inquiries, and finally the final panel meeting where unresolved items were discussed, to draw the conclusion. Among the results, firstly, the highest ranked item on centralized fields for vaccine development by the Ministry of Health was 'self-sufficiency of vaccines.' Secondly, 'emerging infectious disease' was most highly ranked in prioritized fields of vaccine development and research. Thirdly, for the vaccine that needs to be improved and developed further by the government to improve its efficacy and safety, BCG (Bacille de Calmette) for tuberculosis was ranked the highest on both types (intradermal and subcutaneous injection) from National Immunization Programme (NIP) and non-NIP. As for the high risk pathogens, 'anthrax' and 'smallpox' were first and second, consecutively. Lastly, 'development and control of vaccine candidates' was ranked the highest for the area in need for technique development in order to improve domestic vaccine's research level. The results of this study will be put to good use as basic data for the national vaccine research and development (R&D) policy of the country. This study was first step and more studies should be carried out for the final decision of the national vaccine R&D priority.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.189-199
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• 2016

Pending issues present in the Nation Technical Qualifications System (NTQS) have been discussed to deal with the causes and improvements of the issues. The key present situations of the NTQS were investigated to analyze the problems of the NTQS. The acquisition distribution of the items of additional points in employment and the items applied to the laws and regulations of duty employment was revealed to be related with preferential items. The AHP analysis has been conducted based on issues for improvement of the NTQS raised till now. The urgency priority of the elements to be improved was ranked according to the AHP analysis result. The agendas for the improvement of the NTQS was suggested by consideration of the priority of the elements. First, a solution to raise discrimination of the NTQS was suggested by taking the view points of the experts into account. Second, an opinion was proposed that the preferential policies in employment should be directed toward expansion of qualification for duty employment. Third, two ideas were proposed to rectify problems embedded in the technician career handbook system. And four remedies have been made suggested, including the merger of similar events. The results of this research are expected to serve as a useful material for the future design of the NTQS.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.11
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• pp.1169-1174
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• 2015

Risk-Risk-based inspection (RBI) has been developed in order to identify risky equipments that can cause major accidents or damages in large-scale plants. This assessment evaluates the equipment's risk, categorizes their priorities based on risk level, and then determines the urgency of their maintenance or allocates maintenance resources. An earlier version of the risk-based assessment software is already installed within the equipment management system; however, the assessment is based on examination by an inspector, and the results can be influenced by his subjective judgment, rather than assessment being based on failure probability. Moreover, the system is housed within a server, which limits the inspector's work space and time, and such a system can be used only on site. In this paper, the development of independent risk-based assessment software is introduced; this software calculates the failure probability by an analytical method, and analyzes the field inspection results, as well as inspection effectiveness. It can also operate on site, since it can be installed on an independent platform, and has the ability to generate an I/O function for the field inspection results regarding the period for an optimum maintenance cycle. This program will provide useful information not only to the field users who are participating in maintenance, but also to the engineers who need to decide whether to extend the lifecycle of the power machinery or replace only specific components.

• Journal of Environmental Policy
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• v.7 no.4
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• pp.75-103
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• 2008

It is widely recognized that destruction of the eco-system with the counter-effect from the rapid industrialization threatens the life of human species. Furthermore, the extinction of some wild species keeps sending a warning message on the threat to human lives in the sense that both the human and wild lives have coexisted for a long time before the industrialization. Therefore, this study will shed a light on the importance of a natural ecology protection, focusing on wild-life conservation. This will provide an opportunity to consider the economic value of biodiversity through conservation of diverse wild lives and a natural ecology. Also, the irreversible damage to natural resources and extinction of certain species represent the urgency of this issue. This paper will perform a theoretical examination on the concept of wild plants and animals, an analysis of factors influencing their survivals, as well as the theory of natural ecology protections. This also examine the problems arising out of current domestic legislation of a natural ecology protection, comparing it with case studies of foreign countries. Through these analysis, this paper will seek for a maintenance of the currently enforcing natural ecology protection law to overcome its limits and will ultimately find alternatives to current system.