• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.921-926
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• 2006

The present study has been conducted economic analysis through actual operation of EHP and GHP which are installed at the same building of an university Cost items, such as initial cost, annual energy cost and maintenance cost of each system are considered to analyze LCC and economical efficiency is compared. The initial cost is considered on the basis of actual costs, and annual energy cost is converted into the cost after measuring electricity and gas consumption a day. LCC applied present value method is used to assess economical efficiency of both them. Variables used to LCC analysis are electricity cost escalation rate, natural gas cost escalation rate, interest rate, and service lives and when each of them are 4%, 2%, 8%, and 20 years, results of analysis short that EHP(148,257,306 won) is 8.05%(12,981,990 won) more profitable than GHP(161,239,295 won).

• Journal of the Korea Society of Computer and Information
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• v.14 no.7
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• pp.151-160
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• 2009

The aim of this study is to propose economical driving speed index which those are geometric road status; assess the levels of which those cost-benefit of driving energy consumption and emission; are search road safety design and operational technology for driving simulator. For the objective, we analyzed the current status of driving energy consumption and driving scenarios by the road alignments, and reviewed driving and technical specifications by the geometric types of road according to the implementation, and extended completion. Throughout the result of this study, diverse related driving information provision service, efficiently navigation driving module is expected to be implemented in the national highway design system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.1
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• pp.171-175
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• 2015

In this paper, because of global environmental problems such as energy shortage and abnormal climate, green energy development and energy saving technology development is being magnified. Heat insulation, the most basic and traditional energy saving method, is highly expected. Especially, simple and advanced heat insulation technique based on Nano material is promising future technology. The railway system also requires heat insulation. Especially, traditional heat insulator such as glass wool has been adopted frequently to rolling stock. The heat insulator is also adopted in general railway service buildings. Take account of cost-effective heat blocking performance, the heat insulator shall be adopted in diverse fields such as electric power, railroad, signal and communication. The only and direct solution for this problem is installing heat insulator with outstanding endurance, corrosion resistance and heat resistance to block outer heat Upgrading heat specification of equipment can be a solution, but since price and maintenance cost rise severely, this plan might be incongruous. In this research, energy saving effect of ultrathin heat insulator film was demonstrated by installing the film on roof of electrical room.

• Journal of Advanced Navigation Technology
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• v.26 no.6
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• pp.481-486
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• 2022

The recent rapid growth of the IoT(Internet of Things) is leading to the spread of low-power wireless technology. A major challenge in designing IoT wireless networks is to achieve coexistence between different wireless technologies that share the 2.4 [GHz] ISM (Industrial Scientific Medical) frequency band. Therefore, there is a need for research on improving the reliability of wireless networks and coexisting operation between wireless networks. In particular, it is necessary to study an interference model and performance for mutual service coexistence in a BLE (Bluetooth Low Energy) wireless network environment, which is expected to be widely used as a connection medium between devices in various industrial fields. In this paper, the co-channel interference model with the IEEE 802.15.4 system is established focusing on the physical layer of the BLE system widely used in residential and industrial wireless applications, and the performance of the BLE wireless communication system is analyzed in the co-channel interference environment. As a result of the analysis, as the distance between the interference source and the BLE system increases in an environment where noise and co-channel interference exist, the amount of co-channel interference decreases and the error rate performance of the BLE system improves.

• Proceedings of the Korean Society of Crop Science Conference
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• 1999.11a
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• pp.102-144
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• 1999

The major problems of food crop cultivation in Korea are low yield of most crops except rice. inefficient cultivation techniques for aged farmers. and low international competibility. Therefore, development of cultivation techniques of food crops should aim the yield. quality improvement, labor reduction and production cost. The primary issue for increasing the yield of soybean, barely and wheat is to reduce the yield gap between the farmer's yield and recommended ones of experiment station. More advanced cultivation techniques needs to be developed. and/or the conventional breeding methods to be reconsidered. The newly developed labor-saving mechanized technique needs to reduce labor hours , and the cost of agricultural implements and machineries. In other words the labor-saving mechanized technique should be developed based on the improvement of total farming system as well as systemic fundamental innovation of cultural methods. The efficiency of solar energy use in food production of Korea in 1997 is as low as $0.52{\%}$ so there is much room to increase yield. It is recommendable that the concept of food Production should be changed to energy Producing efficiency Per unit area basis from volume and weight of food materials. Moreover, introduction of resonable cropping system is needed to increase yield of main crops, farmer's income, solar energy use efficiency, and decrease of land service expenditure. Current cropping system emphasized on economic crops. especially in vegetables , is not desirable for resonable use of arable land. stability of agricultural management and staple food crop self-sufficiency ratio. It is desirable to increase food crops . that are energy of carbohydrate and protein rich and land dependent crops. in cropping system. And the agronomist should develop the cultural methods to replace food crops for food self-sufficiency and stable farming management instead of economic crops in current cropping system. Low-input and environmentally-sound crop cultivation techniques, especially nitrogen-reducing culture technique which is directly related to food crop quality, also needs to be developed urgently. The extended cultivation of corn in upland and barely and wheat in lowland as a feed stuffs is recommended to prevent further decrease of food self-sufficiency ratio, which is mainly caused by the high reliance on imported feed grain. It is also considered that the calculation and presentation methods of standard agricultural income needs to be improved. The current calculation method uses unit land area of 10a regardless of crop kinds , characteristics of agricultural management and cultivation scale. So, it is apt to lead misunderstanding of farm income value. Therefore. it should show an income of average farmers for certain number of years. Research and developing system for food producing is not desirable because they are conducted currently individual crop and mono-culture basis. But actual agricultural income is usually earned by cropping system including upland and lowland. For example. the barley and wheat is usually cultivated in double cropping system. The cooperation among research institutes such as university agribusiness. government and farmers is indispensible. The public information and education on importance and consumption habit of food crops is necessary in Korean society to increase food self-sufficiency through nationwide cooperation.

• The Journal of Engineering Geology
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• v.26 no.2
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• pp.197-205
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• 2016

Rainfall-induced landslide disaster case histories are typically required to establish critical lines based on the decrease coefficient for judging the likelihood of slope collapse or failure; however, reliably setting critical lines is difficult because the number of nationwide disaster case histories is insufficient and not well distributed across the region. In this study, we propose a method for setting the critical area to judge the risk of slope collapse without disaster case history information. Past 10 years rainfall data based on decrease coefficient are plotted as points, and a reference line is established by connecting the outermost points. When realtime working rainfall cross the reference line, warning system is operating and this system can be utilized nationwide through setting of reference line for each AWS (Automatic Weather Station). Warnings were effectively predicted at 10 of the sites, and warnings could have been issued 30 min prior to the landslide movement at eight of the sites. These results indicate a reliability of about 67%. To more fully utilize this model, it is necessary to establish nationwide rainfall databases and conduct further studies to develop regional critical areas for landslide disaster prevention.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.155-157
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• 2008

An electric multiple unit(EMU) consists of car body, bogie and brake equipment which is directly related to safety and performance of the motorcar. The blending brake mixed an electric brake and a friction brake is to reduce the energy by applying the restoration energy caused when the motorcar is stopped to car lines and to curtail the maintenance cost by saving the friction brake use. We have developed the advanced EMU since 2004, based on the experiences on the standard EMU in 1999, and we develop the installation which minimizes the use rate of the friction air brake by maximizing the electric brake use in the existing blending brake. We could accomplish the goal by improving the motorcar's Performance and solving the restoration energy's deficit by the friction brake. Actually, when it comes to the test results of standard EMU, except the service brake, in most conditions, we use electric brake to meet the requirements of the necessary brake power, exclusive when the motorcar leaves and stops. Therefore, in this paper, we consider the design concept of motorcar's blending brakes and suggest the way to develop the blending brake using the electric brake maximumly, which is caused by adequately controling the electric brake and the restoration brake.

• Journal of the Korea Institute of Building Construction
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• v.2 no.2
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• pp.121-127
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• 2002

The functions and uses of existing buildings are not properly changing as modern life needs. As a result, the frequent reconstruction(construction after removal) of existing buildings have been done but it became more and more difficult because of strengthening of regulations and systems concerning construction. And also it has several disadvantages like lower plot ratio and site coverage than existed buildings, enormous construction cost, production of waste-construction materials and thoughtless consumption of natural resources, which gives rise to environmental pollution. Therefore renovation is brought to the fore. In Korea, many business buildings were constructed in 1960s-1970s, during the period of high growth. Such buildings needs to be repaired in whole. It is caused by the change of social, economic, and cultural conditions and deterioration of equipments. Therefore renovation meets some necessary conditions; recovery of building functions and extension of building life span. In case study, the present state of renovation in business buildings is 1) Basic safety, for example, fire prevention and crime prevention, is great important. 2) Advanced technology, INS(international news service), IBS(Intelligent Building System), and internationalization, is pursued for adapting to multimedia ages. 3) It tries to promote proficiency, and to save the energy using spatial environment and natural energy(light and sound). Also, improving comfortable level of users and installing equipments for physically handicapped person needs to be considered.

• Journal of Environmental Science International
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• v.18 no.2
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• pp.177-186
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• 2009

The changes in the worldwide paradigm of the sustainable development have started to be applied in the entire industry fields, and they come out as the sustainable tourism in the field of tourism. And the ecotourism has emerged as a practical method to meet the needs of the actual practice and the intellectual system for the sustainable tourism. In the type of tourists based on tourist attitude, 82.3% has the environment-friendly tourist attitude as a potential ecological tourist or an ecological tourist. In addition, there are the potentials of increase in ecological tourists as well as the revitalization of ecological tourism. First, the ecological tourists are mostly the well-educated and married professional workers at 40, housewives, and people earning a high income. Next, the potential ecological tourists are mainly the well-educated and married professional workers at 30, workers in the service industry, and middle-class citizens. Lastly, the general tourists are the students at 20 who are single, earn a low income, and has low level of education. This study presents useful data to the tourist business in terms of the development, operation and management of sustainable ecological tourism.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.241-243
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• 2015

Recently, There is increasing interest in the IoT(Internet of Thing) as intelligent information service that enables communication between people and things based on internet. In particular the demand for indoor location-based services with the development of smart devices is rapidly increasing. If iBeacon of BLE(Bluetooth Low Energy) is made available to provide a basic signal for the indoor location information measurement then reliability of Indoor location information for unreliable signal data for a variety of reasons, such as signal interference is significantly lowered. In this paper, Proposes a technique for obtaining an effective and reliable location information via genetic operations in order to obtain reliable location information from the iBeacon signal information.