• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.10
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• pp.58-66
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• 2010

This paper shows an implementation and management result of wireless networks based security light control system, which performs a great role in protection of pedestrians and prevention of crime. Conventional security light units have severe limits in confirmation and inspection of security light unit failure, like wilful damage by someone or failure by influence of other equipment or failure by spontaneous heat-increase, and so on. In addition, local government offices are responsible for maintenance of security light units and as a matter of fact, most of civil complaints are about security light units. It is an obvious that the existing security light maintenance system reaches the limit and the security light maintenance problem is a difficulty of local government. Therefore, efficient security light control system is needed, which enables central control and intelligent maintenance. Moreover, the system has to be easy to control and has to be stable. In this study, wireless sensor network based security light control system is implemented, which is independent of programming language and platform, and which is simple to control and extend the system. The proven protocols, HTTP and SOAP, are utilized in order to improve the system reliability. This paper shows the excellence of our proposed system by implementing and operating it in real environment.

• Journal of KIISE:Databases
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• v.29 no.4
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• pp.321-333
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• 2002

As web-based services are becoming more and more popular, concurrent updates of spatial data should be possible in the web-based environments in order to use the various services. Web-based GIS applications are characterized by large quantity of data providing and these data should be continuously updated according to various user's requirements. Faced with such an enormous data providing system, it is inefficient for a server to do all of the works of updating spatial data requested by clients. Besides, the HTTP protocol used in the web environment is established under the assumption of 'Connectionless'and 'Stateless'. Lots of problems may occur if the scheme of transaction processing based on the LAN environment is directly applied to the web environment. Especially for long transactions of updating spatial data, it is very difficult to control the concurrency among clients and to keep the consistency of the server data. This paper proposes a solution of keeping consistency during updating directly spatial data in the client-side by resolving the Dormancy Region Lock problem caused by the 'Connectionless'and 'Stateless'feature of the HTTP protocol. The RX(Region-eXclusive) lock and the periodically sending of ALIVE_CLIENTi messages can solve this problem. The protocol designed here is verified as effective enough through implementing in the main memory spatial database system, called CyberMap.

• Journal of Biosystems Engineering
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• v.38 no.1
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• pp.25-32
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• 2013

Purpose: The objective of this study is to develop a data middleware for u-IT convergence in agricultural environment monitoring, which can support non-standard data interfaces and solve the compatibility problems of heterogenous sensor networks. Methods: Six factors with three different interfaces were chosen as target data among the environmental monitoring factors for crop cultivation. PostgresSQL and PostGIS were used for database and the data middleware was implemented by Python programming language. Based on hierarchical model design and key-value type table design, the data middleware was developed. For evaluation, 2,000 records of each data access interface were prepared. Results: Their execution times of File I/O interface, SQL interface and HTTP interface were 0.00951 s/record, 0.01967 s/record and 0.0401 s/record respectively. And there was no data loss. Conclusions: The data middleware integrated three heterogenous sensor networks with different data access interfaces.

• Journal of Korean Society of Rural Planning
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• v.10 no.4 s.25
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• pp.55-64
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• 2004

National Agricultural Pesticide Risk Analysis (NAPRA) WWW 시스템 (http://pasture.ecn.purdue.edu/${\sim}napra$)은 각기 다른 영농방법이 지표수질, 유사, 그리고 지하수질에 미치는 영향을 평가하기 위하여 개발되었다. 이 NAPRA WWW 시스템은 Total Maximum Daily Loads와 같은 수질 요건을 만족시킬 수 있는 최적영농 방법이 무엇인지 찾는데, 그리고 수질측면에서 취약한 지역을 찾아내는데 매우 효율적인 시스템이다. 이 NAPRA WWW 시스템을 이용하여 미국 인디애나주의 수계에 대해서, NAPRA 모의 Nitrogen과 Atrazine 결과를 실측치와 비교하였다. 18개 수계에 대해서 NAPRA 예측 질소값과 실측 질소값을 비교한 결과 $R^2$ 값은 0.51이고, 6개 수계에 대해서 NAPRA 예측 Atrazine값과 실측값을 비교한 결과 $R^2$ 값은 0.87이었다. 이 연구에서 보여지는 바와 같이 NAPRA WWW 시스템은 수계내에서 질소와 Atrazine에 따른 오염지역을 찾아내는데 효율적으로 사용될 수 있는 시스템이다.

• Journal of Korean Society of Rural Planning
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• v.9 no.1 s.18
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• pp.85-93
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• 2003

Many features of the Single Field version have been enhanced to provide user friendly interface. The County/Watershed version of NAPRA WWW system was further enhanced. The newly developed Web GIS version is an ideal tool for novice users, such as farmers, to simulate the effects of agricultural management for their farms because of its easy-to-use Web GIS interface. The NAPRA WWW system provides an easy to use WWW interface and uses spatial and relational databases to simplify the process of preparing model files. Thus, the NAPRA WWW systems now can be effectively used for nutrient management as well as pesticide management to identify the least impact agricultural management practices.

• Atmosphere
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• v.23 no.2
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• pp.221-229
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• 2013

There has been an increasing need to assess the effects of climate change on human health. It is hard to use climate data to evaluate health effects because such data have a grid format, which could not represent specific cities or provinces. Therefore, the grid-format climate data of South Korea based on RCP (Representative Concentration Pathway) scenarios were modified into area-format climate data according to the major cities or provinces of the country, up to the year 2100. Moreover, heat index (HI) and discomfort index (DI) databases were developed from the modified climate database. These databases will soon be available for experts via a Website, and the expected HI and DI of any place in the country, or at any time, can be found in the country's climate homepage (http://www.climate.go.kr). The HI and DI were analyzed by plotting the average indices every ten years, and by comparing cities or provinces with index level changes, using the geographic information system (GIS). Both the HI and DI are expected to continually increase from 2011 to 2100, and to reach the most dangerous level especially in August 2100. Among the major cities of South Korea, Gwangju showed the highest HI and DI, and Gangwon province is expected to be the least affected area in terms of HI and DI among all the country's provinces.

• Korean Journal of Ecology and Environment
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• v.51 no.1
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• pp.105-123
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• 2018

Currently, satellite images act as essential and important data in water resources, environment, and ecology as well as information of geographic information system. In this paper, we will investigate basic characteristics of satellite images, especially application examples in water resources. In recent years, researches on spatial and temporal characteristics of large-scale regions utilizing the advantages of satellite imagery have been actively conducted for fundamental hydrological components such as evapotranspiration, soil moisture and natural disasters such as drought, flood, and heavy snow. Furthermore, it is possible to analyze temporal and spatial characteristics such as vegetation characteristics, plant production, net primary production, turbidity of water bodies, chlorophyll concentration, and water quality by using various image information utilizing various sensor information of satellites. Korea is planning to launch a satellite for water resources and environment in the near future, so various researches are expected to be activated on this field.