• Journal of Korean Society for Geospatial Information Science
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• v.16 no.3
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• pp.79-85
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• 2008

This study aims to derive a practical coordinate transformation method for the existing geographic information database. After analyzing the status and problems of existing 1/1,000 digital base map and GIS application database, the transformation parameters are estimated and the accuracy of the transformation is determined based on the transformed coordinates. We analyzed the accuracy of a transformation using the published national transformation coefficients as well as the estimated local transformation coefficients using national and urban control points in a study area. In addition, the 1/1,000 digital base map from aerial triangulation is compared with respect to the coordinates of urban control points. Based on the comparison, the biases on the national control points which were used at the time of digital map generation was analyzed. Then, the accuracy of transformed coordinates based on the world geodetic system using local transformation coefficients estimated from urban control points are determined. We also analyzed the transformation accuracy of underground infrastructure database using the same transformation method as the case of 1/1,000 digital base map. Through this study, it was found that the estimation of transformation coefficients by Molodensky-Badekas using urban control points was suitable for a local government. Furthermore, it was obvious that the accuracy of a 2-dimensional affine transformation was comparable to that of 7 parameter transformation for a local area. Applying the coordinate transformation and bias correction, we could transform GIS application database which was built by an offset surveying based on digital base map within the transformation accuracy of 10 cm. Therefore, it was judged that there will not be a big problem on the transformation of the GIS DB to the world geodetic system.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.4
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• pp.189-197
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• 2007

GIS is the tool widely used for the practical solution of spatial problems in every region regardless of the language and ideology. In this paper research trends and tendencies of GIS in North Korea are reviewed compared with those in South Korea. For this purpose, academic publications on GIS in North Korea are surveyed and classified according to main subjects in GIS. Such classification by main subjects of GIS in North Korea are conducted on the basis of the classification of research trends and tendencies of GIS in South Korea. As a result, researches in North Korea are mainly focused upon such fields as geodetic surveying and measurement, map manufacture, atmospheric phenomena, agriculture and disasters, while there are few studies related to such fields as national GIS policy and circulation, GIS education, internet-based GIS, and traffic, to name but a few. Most parts of applied data are based on low and medium resolution image such as meteorological satellite images, Landsat images, and so on. This reflects the low level of the development of GIS DB infrastructure in North Korea.

• Journal of Korea Game Society
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• v.5 no.1
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• pp.61-66
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• 2005

The item is an interactive element to escalate interest in the games as well as element providing various satisfactions to players. They give satisfactions to economic desire which is intrinsic in human beings. In this paper we propose an efficient method for item productions and managements by giving name values to items and managing them by database, so that new communities of players could grow with economic systems, which would improve specialties of games as well as solve problems such as hacking, etc.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04b
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• pp.718-720
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• 2002

현재 교사를 위한 다양한 인격 연수가 시행되고 있다. 그러나 연수 내용을 살펴보면 교사 연수의 핵심이라고 할 수 있는 교수법 향상에 관련된 내용보다는 교과의 전문지식이나 기능적인 부분에 대해 더 많이 다루고 있는 것이 사실이다. 교사들은 대학에서 뿐만 아니라 교육 현장에서 자기 연수 혹은 연수 기관을 통해 끊임없이 교수법 향상을 위해 노력해야한다 연수 기관에서 그룹별 토의 시스템, 동영상 동기화 교수-학습 지도안 제작 도구, 교수학습 DB 등으로 구성된 인지적 도제 모델형 원격 연수 시스템을 이용한다면 좀 더 나은 교수법 향상을 기대할 수 있을 것이다.

• The Journal of the Korea Contents Association
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• v.9 no.10
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• pp.22-31
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• 2009

Although the amount of UCC(user created content) rapidly grows nowadays, there are various problems in authoring, distribution and management of this abundant content because the platforms for fabrication and replaying content are not compatible and the authoring environments are not sufficiently interoperable with other site or with each other. In this paper, we propose a CPMS(content publication and management system) scheme improved in interoperability to solve these problems, and we design a novel system enhancing the efficiency and speed of content distribution and management by minimizing the repetitions in the processes of production, reshaping, and publication. Moreover the proposed system adopts an improved content management technology by changing from simple point-to-point method to the centralized distribution method, and as for the service scheme, we change from the site link method to the database link method, and we also take duplex interlink scheme instead of simplex one. We finally compare the proposed system to the conventional ones as points of view of compatibility and interoperability to prove the improved performance of our system.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.5
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• pp.537-546
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• 2008

The digital map has been updated in every five years in the past. However, it has been changed to make corrections and updated in every two years for metropolitan region and every four years for other regions since year 2008. Although, the correctness and reliability were decreased and updating work is being delayed due to the updating work in a lump. The period update spends a lot of money because this method uses aerial photogrammetry, and the digital map has the time gap between periods. Therefore, this study provides information necessary for digital map produced by the government and develops digital map production system based on objects which can be updated frequently in order to save state and local government budgets that double investment are generated to update digital map. In order to analyze usefulness of the developed system, subject area was selected and errors of updated data were analyzed. As the result of analysis, checked 66 errors were corrected and saved in the database.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.4
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• pp.234-243
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• 2022

In Korea, hail damage occurs every year, and in the case of agriculture, it causes severe field crop and cultivation facility losses. Therefore, it is necessary to develop a hail information service system customized for Korea's primary production and crop-growing areas to minimize hail damage. However, the observation of hail is relatively more difficult than that of other meteorological variables, and the available data are also spatially and temporally variable. A hail information service system was developed to understand the temporal and spatial distribution of hail occurrence. As part of this, a hail observation database was established that integrated the observation data from Korea Meteorological Administration with the information from newspaper reports. Furthermore, a hail risk map was produced based on this database. The risk map presented the nationwide distribution and characteristics of hail showers from 1970 to 2018, and the northeastern region of South Korea was found to be relatively dangerous. Overall, hail occurred nationwide, especially in the northeast and some inland areas (Gangwon, Gyeongbuk, and Chungbuk province) and in winter, mainly on the north coast and some inland areas as graupel (small and soft hail). Analyzing the time of day, frequency, and hailstone size of hail shower occurrences by region revealed that the incidence of large hail stones (e.g., 10 cm at Damyang-gun) has increased in recent years and that showers occurred mainly in the afternoon when the updraft was well formed. By integrating multidisciplinary data, the temporal and spatial gap in hail data could be supplemented. The hail risk map produced in this study will be helpful for the selection of suitable crops and growth management strategies under the changing climate conditions.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6D
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• pp.771-779
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• 2009

Digital topographical maps used for GIS DB are mainly produced by the traditional way of analogue aerial photogrammetry. Therefore, analogue photos are only available for digital mapping after preprocessing such as film developing, printing and scanning. However, digital aerial camera is able to get digital image directly without preprocessing and thus the performance and efficiency of photogrammetry are extremely increased. This study aims to investigate geometric stability of digital aerial frame camera DMC (Digital Modular Camera). In order to verify the geometric stability of digital aerial camera DMC, some different block conditions with and without cross strips, GPS/INS data and variation of GCPs are introduced in the block adjustment. The accuracy results of every block condition were compared each other by computation of residuals of exterior orientation (EO) parameters. Results of study shows that the geometric stability of the block adjustment with cross strips is increased about 30% against without cross strips. The accuracy of EO parameters of block adjustment with cross strips is also increased about 2cm for X-coordinate, 3cm for Y-coordinate, 3cm for Z-coordinate, and 6" for omega, 4" for phi and 3" for kappa.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.6
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• pp.93-98
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• 2010

Recently, users using social network service(SNS) with smart phone as well as users using smart phone are so rapidly increasing. In this paper, Android based local SNS system is proposed and developed. The main feature and contribution are as follows. First, the proposed SNS system is developed based on smart phone Android for supporting both the search of neighbor users and the addition of friends to start SNS with Web/DB. Second, the system is designed with the unchanged basic UI of Android and user oriented approach. The performance evaluation is performed by using OPTIMUS-Q/ANDROID 2.1. The results of performance evaluation show that the proposed SNS system can efficiently support the neighbor search services by using android based bluetooth neighbor search. Currently, we are still ongoing working on bluetooth autofaring in android to improve the performance of the proposed system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.8
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• pp.851-856
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• 2010

This paper presents an efficiency enhancement for the balanced power amplifier using DBS(Dynamic Bias Switching) method which dynamically provides the power amplifier with two bias voltage levels according to the input envelope signal. In order to apply the dynamic biases to each side of the balanced power amplifier, two switching stages are adopted. Using an OFDM signal with a bandwidth of 20 MHz and a PAR(Peak to Average Ratio) of 8.5 dB, 6 % of PAE(Power-Added Efficiency) is improved at an output power of 42.5 dBm.