• Journal of the korean Society of Automotive Engineers
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• 제14권5호
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• pp.128-135
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• 1992

Using a commercial flow-analysis code VSAERO, a method to predict the drag of an automobile induced by the intake air of the cooling system has been devised. Given the pressure loss coefficient across the radiator, which varies with the radiator shape and the local Re, a simplified model of the internal flow is coupled with VSAERO to find the mass-flow rate through the car. The flow rate is obtained iteratively and that, in turn, gives the drag associated with this flow, which essentially is the momentum carried by the drained air. The results of a few sample cases are presented for two front-end shapes in combination with varying radiator frontal area.

• Journal of information and communication convergence engineering
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• 제7권2호
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• pp.87-91
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• 2009

Over the past several years both licensed and unlicensed services and devices have enjoyed extensive growth in the wireless marketplace. In some urban areas in the Kazakhstan, the penetration rate of licensed cellular and PCS services is more than 60%. Similarly, the use of unlicensed wireless local area network technologies has grown significantly as these systems have been deployed in homes, offices, and 'hot spots' in restaurants, hotels, public meeting areas, etc. As more services are wirelessly enabled and as technologies continue to evolve, the demand for new spectrum for commercial services will also continue to increase. Thus, the appropriate regulatory models for future spectrum allocations will continue to be debated throughout the wireless industry.

• Journal of the East Asian Society of Dietary Life
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• 제7권1호
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• pp.41-46
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• 1997

Diet is generally accepted as one of the important factors in human cancer development. Ethyl carbamate has been associated with cancer for several decades and mainly found in the fermented beverages and foodstuff. The relationship between ethyl carbamate and the human health cannot be ignored especially in the areas where fermented foods consists of regular food consumption. To investigate the ethyl carbamate exposure level in Korean population, commercial fermented food samples were collected form local markets I Seoul area and home-made varieties were collected throughout the country. Following partial purification the concentration of ethyl carbamete was determined by GC/ MS. The concentration of ethyl carbamate ranged to 70 ppb in soysauce, to 10 ppb in soybean paste, and to 5 ppb in vinegars. Korean traditional alcoholic beverages showed small amount of ethyl carbamate. The estimated daily exposure of Korean population was 0~1900ng/day. It would be prudent to put efforts to minimize the formation of ethyl carbamate since the risk from the higher range exposure cannot be ignored.

• The Journal of Information Systems
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• 제17권1호
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• pp.131-153
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• 2008

So many location based service systems, including automobile navigation system logistic management, taxi fleet management, and so on, are being used everywhere. However, these are all outdoors. This paper provides a stepping stone for commercial indoor location based services by developing an integrated system of our indoor positioning and map viewer modules. For the indoor positioning, we propose WLAN (Wireless Local Area Network) based EKF (Extended Kalman Filter) which estimates user's current location and tracts user's trace in the sequence of time. Our map viewer renders a map recorded in an Autocad DXF file and provides functions of map manipulation such as zoom-in, zoom-out, and move. We integrate our indoor positioning and map viewer modules and discuss the experimental results of the integrated system.

• International conference on construction engineering and project management
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.956-961
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• 2009

When construction engineers perform their work in the jobsite, they have to record as-built conditions in the project log (Data Collection). On the other hand, the engineers often have to refer to the construction documents when necessary at the job faces (Data Access). The practice of Data Collection and Data Access in the jobsite can be greatly enhanced by utilizing mobile computing with wireless communications. In this paper, two cases of mobile computing applications for construction field management are presented; Mobile Specifications System and Mobile Data Collection System. The demonstration of the process for developing two mobile applications is the primary purpose of the paper. The problems and issues involved with adopting mobile computing for construction field are also presented. The simple information framework for mobile computing has been also proposed as an outcome of the research. As for development tools, readily available relational database and wireless network have been used. The use of commercial mobile broadband was examined for data communication where local area network is not available.

• Proceedings of the Korea Information Processing Society Conference
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• 한국정보처리학회 2010년도 추계학술발표대회
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• pp.958-961
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• 2010

We can monitor home from any remote location using our existing telephone line. We have already some technologies to perform these types of application such as: Bluetooth, IR. But these are used in a limited area which we can easily come over in our system. Our propose system has two sections one is Remote Section (RS) where the client will place the request and another is Local Section (LS) where the telephone line is connected with an Input Interfacing Circuit (IIC). Input Interfacing Circuit (IIC) receives the frequency and converts frequency to machine language. Output Interfacing Circuit (OIC) sends voice signal to the client as acknowledgement through modem then the client proceeds for the next steps. This system can be used in commercial or industrial purposes such as controlling computer from remote locations, home monitoring system instead of man or any kind of switching.

• The Journal of Economics, Marketing and Management
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• 제3권2호
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• pp.21-28
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• 2015

The purpose of the study was to investigate state and problems of Seongnam Jungang Market that lost competitiveness under rapidly changing logistics environment, and to give market redevelopment model, project validity and operation management plan considering commercial area and location of the market. The public market at the community that has tradition and culture of the residents provides small merchants with employment chance and to let residents buy daily necessities. The market allows farmers to sell agriculture products by themselves and to increase income. Most of public markets that open every five days help residents meet each other to exchange information. Most of public markets have been placed at local towns and rural areas to lose distribution functions remarkably at less population and quick aging.

• Electronics and Telecommunications Trends
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• 제33권3호
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• pp.1-10
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• 2018

This article presents spectrum sharing policy trends both overseas and domestically. The Federal Communications Commission recently adopted rules for the commercial use of a 150 MHz bandwidth at 3.55 to 3.7 GHz, which has been utilized for defense and satellite services. This frequency band for spectrum sharing is called the citizens broadband radio service (CBRS) band. In Europe, the related regimes for licensed shared access application at 2.3 to 2.4 GHz has been organized, and interface standardization for sharing frequency information has been completed. In Korea, efforts are being made to establish spectrum-sharing policies to improve the efficiency of the frequency utilization. This article also introduces both the IEEE 802 local area network/metropolitan area network and 3GPP standardization activities with regard to frequency sharing technologies. To effectively solve the spectrum-sharing problem in IEEE 802, standardization activities on the CBRS and the mid-band (3.7-24 GHz) are underway. 3GPP is currently developing the standardization of a licensed assisted access technology, which extends mobile communication services provided in the licensed band to unlicensed bands.

• The Journal of Korean Institute of Information Technology
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• 제16권12호
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• pp.13-24
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• 2018

Recently, light pollution has become a serious environment issue caused by excessive uses of artificial light. Central and local governments have made efforts to manage light pollution and mitigate light pollution damages. Developing methods to diagnose light pollution is critical to effectively monitor light pollution conditions in Seoul. This study develops a methodology to create a map that presents the status of light pollution in Seoul, using International Space Station(ISS) night-time images. Through the map, we evaluated the areas that show high levels of light intensity and found out local characteristics of light intensity; Commercial area, office building concentrated area, and large sports facilities. The result of study provides basic understanding to present a new way for monitoring light pollution in urban sites.

• Journal of Korean Society for Geospatial Information Science
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• 제23권2호
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• pp.3-9
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• 2015

Since changes in land use in urban space cause traffic volume and it is closely related to traffic accidents. Therefore, an analysis on the causes of traffic accidents is judged to be an essential factor to establish the measure to reduce traffic accidents. In this regard, the analysis was conducted on the clustering by using the nearest neighbor indexes with regard to the occurrence frequencies of commercial and residential zone based on traffic accident data of the past five years (2009-2013) with the target of local small-medium sized city, Jinju-si. The analysis results, obtained in this study, are as follows: the occurrence frequency of traffic accidents was the highest in spring and the lowest in winter respectively. The clustering of traffic accident occurrence at nighttime was stronger than at daytime. In addition, terms of the analysis on the clustering of traffic accident according to land use, changes according to the seasons was not significant in commercial areas, while clustering density in winter tended to become significantly lower in residential areas. The analysis results of traffic accident types showed that the side-right angle collision of cars was the highest in frequency occurrence, and widespread in both commercial areas and residential areas. These results can provide us with important information to identify the occurrence pattern of traffic accidents in the structure of urban space, and it is expected that they will be appropriately utilized to establish measures to reduce traffic accidents.