• Journal of Positioning, Navigation, and Timing
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• v.4 no.2
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• pp.43-55
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• 2015

In the case of satellite navigation positioning, the shielding of satellite signals is determined by the environment of the region at which a user is located, and the navigation performance is determined accordingly. The accuracy of user position determination varies depending on the dilution of precision (DOP) which is a measuring index for the geometric characteristics of visible satellites; and if the minimum visible satellites are not secured, position determination is impossible. Currently, the GLObal NAvigation Satellite system (GLONASS) of Russia is used to supplement the navigation performance of the Global Positioning System (GPS) in regions where GPS cannot be used. In addition, the European Satellite Navigation System (Galileo) of the European Union, the Chinese Satellite Navigation System (BeiDou) of China, the Quasi-Zenith Satellite System (QZSS) of Japan, and the Indian Regional Navigation Satellite System (IRNSS) of India are aimed to achieve the full operational capability (FOC) operation of the navigation system. Thus, the number of satellites available for navigation would rapidly increase, particularly in the Asian region; and when integrated navigation is performed, the improvement of navigation performance is expected to be much larger than that in other regions. To secure a stable and prompt position solution, GPS-GLONASS integrated navigation is generally performed at present. However, as available satellite navigation systems have been diversified, finding the minimum satellite constellation combination to obtain the best navigation performance has recently become an issue. For this purpose, it is necessary to examine and predict the navigation performance that could be obtained by the addition of the third satellite navigation system in addition to GPS-GLONASS. In this study, the current status of the integrated navigation performance for various satellite constellation combinations was analyzed based on 2014, and the navigation performance in 2020 was predicted based on the FOC plan of the satellite navigation system for each country. For this prediction, the orbital elements and nominal almanac data of satellite navigation systems that can be observed in the Korean Peninsula were organized, and the minimum elevation angle expecting signal shielding was established based on Matlab and the performance was predicted in terms of DOP. In the case of integrated navigation, a time offset determination algorithm needs to be considered in order to estimate the clock error between navigation systems, and it was analyzed using two kinds of methods: a satellite navigation message based estimation method and a receiver based method where a user directly performs estimation. This simulation is expected to be used as an index for the establishment of the minimum satellite constellation for obtaining the best navigation performance.

• Journal of the Korean Society for Nondestructive Testing
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• v.36 no.5
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• pp.353-362
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• 2016

Thermal barrier coating (TBC) is an essential element consisting of a super-alloy base and ceramic coating designed to achieve long operational time under a high temperature and pressure environment. However, the top coat of TBC can be delaminated at certain temperatures with long operation time. As the delamination of TBC is directly related to the blade damage, the coupling status of the TBC should be assured for reliable operation. Conventional studies of nondestructive evaluation have been made for detecting generation of thermally grown oxide (TGO) or qualitatively evaluating delamination in TBC. In this study, the ultrasonic C-scan method was developed to obtain the damage map inside TBC by estimating the delamination in a quantitative way. All specimens were isothermally degraded at $1,100^{\circ}C$ with different time, having different partial delamination area. To detect partial delamination in TBC, the C-scan was performed by a single transducer using pulse-echo method with normal incidence. Partial delamination coefficients of 1 mm to 6 mm were derived by the proportion of the surface reflection signal and flaw signal which were theoretical signals using Rogers-Van Buren and Kim's equations. Using the partial delamination coefficients, the partial delamination maps were obtained. Regardless of the partial delamination coefficient, partial delamination area was increased when degradation time was increased in TBC. In addition, a decrease in partial delamination area in each TBC specimen was observed when the partial delamination coefficient was increased. From the portion of the partial delamination maps, the criterion for delamination was derived.

• Journal of Korean Society of Forest Science
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• v.109 no.2
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• pp.179-188
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• 2020

Weeding refers to the process of removing weeds around crop trees, which cause competition in nutrients, moisture, and light, and has a great effect on the early growth and survival of crop trees for establishing forest resources. This study was conducted to find out the timing and method of weeding that is the most suitable for the major afforestation species in national forests. We investigated (1) weeding time and frequency for each afforestation species and (2) the height of crop trees and the length of weeds. Up to 99% weeding operation was carried out until 5 years following afforestation. Pinus densiflora, Larix kaempferi, Chamaecyparis obtusa, Prunus sargentii, and Betula platyphylla plantations accounted for more than 70% of the total weeding sites. Once-a-year weeding process was conducted from late June to late July (67%), and twice-a-year weeding process was the highest in June-August by 31%. Most species were shorter than the weeds until the first and second year of planting, but the height of the crop trees was higher than that of the weeds by 48% in average from the third year. Therefore, from the third year of afforestation, except for some species, it is possible to reduce the cost of weeding operations while reducing nutrient competition by the weeds through the removal of weed sprouts, mainly woody weeds, rather than clear cutting. This study contributes to efficiently develop forest resource establishment while reducing operational costs through a detailed weeding schedule and species-specific method.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.1
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• pp.65-74
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• 2016

Recently our government has presented the realization of 'Creative Economy' as a primary goal of the state administration through encouraging start-ups and ventures. Activation of entrepreneurship education is an important task for a national job creation and entrepreneurship activation policy. Since 2012, as a mid and long term project, the Korea Ministry of Education has led to activate creative entrepreneurship, entrepreneurship education and entrepreneurial culture within university by installing entrepreneurship centers respectively in 61 universities. In this study, we provide future entrepreneurship improvement subject and policy implication through the case analysis of entrepreneurship center operation and management. In order to achieve the research purpose, we will examine the program and condition of successful entrepreneurship centers in overseas universities and explore the factors that can enhance domestic entrepreneurship center development and operational effectiveness by analyzing 61 university-entrepreneurship center survey. First, primary research was conducted through survey focusing on organization and operation of centers, entrepreneurship education, startup support for students and entrepreneurship culture activation to proceed with comparative analysis. Through this case study, we expect to be able to derive policy implications for the effective operation of entrepreneurship center and the nurture of creative entrepreneurial young generation.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.1
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• pp.113-123
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• 2012

This study aims at identifying whether graduate school of Entrepreneurship is proposed as an alternative for institution enhancing the expertise of entrepreneurship education which is demanded these days and also examining which forms of graduate school of Entrepreneurship is needed between special graduate school of Entrepreneurship and professional graduate school of Entrepreneurship. Three researches are made by this study. First of all, status of special graduate schools of Entrepreneurship and advanced studies are researched and secondly, educational performance and operational performance of them are researched and how they secure the prestige as a professional institution for educating Entrepreneurship has been analyzed. Finally, what needs of switching over from special graduate school of Entrepreneurship to professional graduate school of Entrepreneurship has been rveyed As a result, graduate school of Entrepreneurship has been established at five rovince in Korea. Doctoral course of Entrepreneurship has been opened independently in U. S. A. And also high performance of promoting Entrepreneur and consultant for Entrepreneur has been researched. Level of satisfaction on education program and faculties has been surveyed highly. High demand for reconversion to professional graduate school of Entrepreneurship and doctoral course of Entrepreneurship has been investigated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.594-600
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• 2018

Landscape law was enacted in 2007 after the development of the Korea Planning Support System (KOPSS) in 2006. In addition, KOPSS was utilized by many local governments to improve reliability and optimization in 2010. In 2014, landscape law was fully revised, and it is likely to have a considerable impact on municipal ordinances and deliberations, which may have a considerable effect on the results of landscape reviews. This paper presents an analysis and verification of changes in the subject of deliberation by the amendment of the law and system, the method of deliberation, the composition of the scenery committee, and the introduction of KOPSS. We also propose a direction for improving the landscape deliberation system. As a result, the change of the number of deliberation items repeatedly increased and decreased due to the change of the deliberation subject and deliberation management according to the total revision of the resultant laws and institutions. In sum, it affected the deliberation decisions.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.9
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• pp.2097-2104
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• 2013

Scientific and technological research data is increasing exponentially and, Kisti(Korea Institute of Science and Technology Information) built and supported GSDC(Global Science experimental Data hub Center) depending on the needs processing large data computing and storage devices. Mobile web standards-based the MUPS was built for global community and services of gsdc to spreading mobile devices rapidly. And for analyze Operational status and system resources of GSDC at n this paper researched and implemented system resource monitor method of gsdc to mobile web environment, in this paper researched and implemented system resource monitor method of gsdc to mobile web environment. Research support system of GSDC operated by scientific linux. Sysstat resource monitoring tools create a daily report through sar(system analysis report), after sadc(system activity data collector) collected system resource utilization information. In this paper, sar reports designed and implemented in mobile web to can visualize in a mobile environment. We do not depend specific OS by implementation of the mobile web. So we are available in variety mobile OS. And through provided visual graph, this system can monitor easily and more conveniently then the existing system.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.193-199
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• 2006

This article reviews several microwave instruments employed in observation and analysis of tropical cyclones (TCs), typhoon, and hurricanes. Microwave signals are useful for observing tropical cyclones with severe storms since it isn't severely absorbed by the clouds and rain in the storm. The instruments discussed include scatterometers, microwave radiometers, synthetic aperture radars (SARs), and rain radar from space. The date such as winds, rainfall and cloud-distribution in the TCs obtained by microwave instruments provide important informations for forecasting the intensity and path of the typhoon. For example, there're wind-distribution provided by SSM/I which has a wide swath, detailed wind fields from ERS-1, 2 scatterometers and RADARSAT-1 SAR and TRMM's rain radar pro 떠 ding high resolution. Operational satellite instruments lunched recently have improved upon the problems of low resolution and narrow swath indicated at the beginning microwave remote sensing. Understanding and practical using sufficiently about the microwave instruments will serve for searching the features such as generation and development of the TCs.

• Strategy21
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• s.45
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• pp.148-187
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• 2019

This paper is to analyse the necessity and development direction of the ROK's maritime security strategy white paper. To this end the paper is composed of 5 chapters titled introduction; the necessity of the ROK's maritime security strategy white paper; the ROK's actual situation in relation to maritime security strategy and cases of major advanced oceanic countries; the vision, goals, strategic tasks, and implementation system of the ROK's 'national maritime security strategy'; and conclusion. The achievement of the national marine strategic vision, such as the 'Ocean G5,' is of course possible when Korea can maintain and strengthen the maritime safety and maritime security of the people. The Sewol Ferry incident reminds us that we need a 'national maritime security strategy white paper' like the advanced marine countries. In order for the national maritime security strategy to be carried our efficiently, as in advanced oceanic countries, mere should be a dedicated department with sufficient authority and status to mobilize the cooperation of related organizations including naval-coastal cooperation. It would be good to set up a tentatively named Maritime Security Council, an organization of minister-level officials involved under the National Security Council, and an executive body composed of working-level officials from related ministries. In order to successfully carry out the national maritime security strategy for the maritime safety and maritime security of the people like the United States and the United Kingdom, we need to further strengthen our domestic cooperation and cooperation system, international cooperation, and maritime security. We have to promote the establishment and promotion of maritime security strategies by the Navy; strengthening the operational link between the Navy and the Coast Guard; strengthening the maritime surveillance capability at the national level, and promoting sharing with the private sector, etc.

• Journal of Environmental Policy
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• v.11 no.4
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• pp.85-105
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• 2012

In this paper, the energy efficiency of wastewater utilities was evaluated to explore ways to save energy via operational measures. The correlation of each wastewater characteristic parameter to energy was assessed to find a set of parameters that explained most of the variations in energy use among utilities. The results show that increases in inflow, influent COD concentration, and ratio of advanced treatment generally increased the energy use. On the other hand, increases in load factor (influentaverage flow/design flow) reduced the energy use. In the regression analysis, the energy efficiency was highest in the A2O advanced process. On the other hand, the membrane process (among the advanced processes) and the contacted aeration process (among the secondary processes) require more efforts in saving energy. However, the data base system related to energy use must be supplemented in order for more accurate analysis of energy consumption in wastewater treatment facilities. In particular, i) electricity consumption of relay pumps and, ii) energy usage per unit process, iii) pump power usage to discharge treated wastewater in a long distance, if necessary, and iv) alternative energy production and utilization status must be recorded. By utilizing the results of the analysis conducted in this study, it is possible to quantify a level of energy savings needed and establish customized energy saving measures to achieve a certain target level for benchmarking a successful case of wastewater utilities.