• Spatial Information Research
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• v.16 no.3
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• pp.373-383
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• 2008

LiDAR, unlike satellite imagery and aerial photographs, which provides irregularly distributed three-dimensional coordinates of ground surface, enables three-dimensional modeling. In this study, urban area was classified based on 3D information collected by LiDAR. Morphological and spatial properties are determined by the ratio of ground and non-ground point that are estimated with the number of ground reflected point data of LiDAR raw data. With this information, the residential and forest area could be classified in terms of height and density of trees. The intensity of the signal is distinguished by a statistical method, Jenk's Natural Break. Vegetative area (high or low density) and non-vegetative area (high or low density) are classified with reflective ratio of ground surface.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2002.04a
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• pp.3-10
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• 2002

요즘 측량분야에서 Geomatics 또는 Geoinformatics라는 새로운 용어가 대두되고 있다. 해외의 유수 기관 및 대학교에서도 측량이라는 학과명 또는 기관명을 Geomatics라는 용어로 교체하고 있으며, 이는 측량분야의 다양화와 학제간 연구수행의 필요성을 반영하는 것이다. 최근 45로 일컬어지는 GPS, 원격탐사(RS), GIS, ITS의 경우 각기 독자적인 영역을 구축하기보다는 상호 보완적인 역할을 하며 통합되어 가는 추세이다. 1950년대에 기본적인 위성관측기술 및 계산 기술의 개발을 시작으로 1980년대에 이르러서는 위성 기술은 측지학 및 측량 분야에 적용되기 시작했다. 그 대표적인 것이 GPS(Global Positioning System)로 기존의 천체측정학 방식을 대체하는 유용한 위치결정 수단으로 사용되기 시작했다. DNSS로부터 시작된 GPS는 측지 측량분야, 지구물리학분야, 항법 및 교통, GIS Mapping, 기상 및 해양, 재난 및 레저, 인공위성 궤도결정 등 다양한 분야에 적용되었으며, 특히 2000년 5월 1일 SA가 해제되면서 그 활용도는 더욱 증가하고 있다. 위성원격탐사의 경우 초창기에 중ㆍ저해상도의 다중분광영상에서 시작하여 그 해상도가 꾸준히 향상되어 오늘날 0.61 미터급 고해상도 위성인 QuickBird 위성이 발사되어 운용 중에 있다. 위성영상의 공간해상도, 분광해상도, 방사해상도는 향후 계속 향상될 것이며 이에 따른 방대한 데이터의 처리 문제 및 하드웨어/소프트웨어 지원에 대한 연구가 수반되어야 할 것이다. GPS 및 원격탐사(RS)는 더 이상 독자적인 영역으로서가 아니라 Geomatics를 이루는 중요한 분야로서 타 시스템과의 보완적인 관계로서 통합되어 나갈 것이다. 이를 위해서는 공간정보에 대한 표준화 및 데이터 처리, 통합, 시스템 구축을 위한 기술적 연구가 계속 진행되어야 할 것이다.분 공부상면적보다 늘어났다. 2. 좌표의 이동량이 일률적이지 못하므로 기초점에 대한 문제라고 생각되며, 따라서 도해지적을 수치지적으로 전환함에 있어서 가장 우선되어야 할 사항이 기초점 정비라 하겠다.승이 뚜렷하였다. 따라서 비파 착즙액 첨가 기능성 yoghurt 제조시 비파 착즙액을 10% 첨가하여 혼합 starter로 Str. thermophilus와 Lac. acidophilus 혼합균주를 사용하는 것이 이들 유산균의 증식에 가장 적합한 것으로 나타났다.타났다..297, 0.293, 0.205에서 50일 경과 후 0.612, 0.472, 0.898로 비살균에서 높은 값을 보였다. 따라서 비살균의 경우 저장말기에 TBA값이 높아지는 경향을 보였다. 5. L값은 살균처리의 경우 저장 30일 이후 약간 어두워지는 경향을 보였고, 121$^{\circ}C$ 살균처리에서 높은 값을 보였다. 대체로 저장온도가 높고 저장기간이 길어질수록 약간 밝아지는 경향을 보였다. 적색도는 인삼 첨가구의 경우 상온 및 냉장저장에서 10$0^{\circ}C$ 살균이 121$^{\circ}C$ 처리구 보다 약간 높은 값을 보였다. 저장기간에 따른 적색도의 변화는 인삼과 송이 첨가구에서 비교적 안정적이었다. 황색도는 상온 및 냉장저장에서 저장기간에 따라 약간 감소하는 경향을 보인 후 상온저장 50일 째, 냉장 60일 째 가장 높게 나타났다. 121$^{\circ}C$ 살균처리구가 10$0^{\circ}C$ 처리구보다 약간 높은 경향을 보였다.^{\circ}C$$,에서는 20시간 가열시 0.706$\mu\textrm{g}$/kg으로 가장 높게 생성된 후 서서히 감소하였다. 그러나 산값과 공액이중산값은 계속 증가하는 양상을 나타냈다. 즉 B(a)

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.3
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• pp.10-24
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• 2014

Bicycle is a useful transportation mode that is healthy, emission-free, and environmentally compatible. Although large efforts have been made to promote the use of bicycling to date, there still exist various hurdles and limitations. One of the key issues to increase bicycling is how to gather bicycle-related data from the field and to generate valuable information for both users and operations agencies. This study proposes a method to process bicycle trajectory data which is obtained from tracing global positioning systems(GPS) equipped bicycle, which is defined as the probe bicycle. The proposed method is based on the concept of statistical quality control of data. In addition, a data collection and processing scenario in support of public bicycle system is presented. The outcomes of this study would be valuable fundamentals for developing bicycle traffic information systems that is a part of future intelligent transportation systems(ITS).

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.11
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• pp.183-190
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• 2012

Conventional physical activity monitoring systems, which use accelerometers, global positioning system (GPS), heartbeats, or body temperature information, showed limited performances due to their own restrictions on measurement environment and measurable activity types. To overcome these limitations, we developed a portable exercise analysis system that can analyze aerobic exercises as well as isotonic exercises. For bioelectric signal acquisition during exercise, waist belt with two body contact electrodes was used. For exercise analysis, the measured signals were firstly divided into two signal groups with different frequency ranges which can represent respiration related signal and muscular motion related signal, respectively. After then, power values, differential of power values, and median frequency values were selected for feature values. Selected features were used as inputs of support vector machine (SVM) to classify the exercise types. For verification of statistical significance, ANOVA and multiple comparison test were performed. The experimental results showed 100% accuracy for classification of aerobic exercise and isotonic resistance exercise. Also, classification of aerobic exercise, isotonic resistance exercise, and hybrid types of exercise revealed 92.7% of accuracy.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.8
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• pp.2052-2063
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• 1998

Various full-scale radio location systems have been developed since ground-based radio navigation systems appeared during World War II, and more recently global positioning systems (GPS) have been widely used as a representative location system. In addition, radio location systems based on cellular systems are intensively being studied as cellular services become more and more popular. However, these studies have been focused mainly on macrocellular systems of which based stations are mutually synchronized. There has been no study about systems of which based stations are asynchronous. In this paper, we proposed two radio location algorithms in microcellular CDMA systems of which base stations are asychronous. The one is to estimate the position of a personal station at the center of rectangular shaped area which approximates the realistic common area. The other, as a method based on road map, is to first find candidate positions, the centers of roads pseudo-range-distant from the base station which the personal station belongs to and then is to estimate the position by monitoring the pilot signal strengths of neighboring base stations. We compare these two algorithms with three wide-spread algorithms through computer simulations and investigate interference effect on measuring pseudo ranges. The proposed algorithms require no recursive calculations and yield smaller position error than the existing algorithms because of less affection of non-line-of-signt propagation in microcellular environments.

• Journal of Intelligence and Information Systems
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• v.16 no.4
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• pp.147-157
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• 2010

With the immergence of the iPhone, the interest in Smartphones is getting higher as services can be provided directly between service providers and consumers without the network operators. As the number of international tourists increase, individual tourists are also increasing. According to the WTO's (World Tourism Organization) prediction, the number of international tourists will be 1.56 billion in 2020,and the average growth rate will be 4.1% a year. Chinese tourists, in particular, are increasing rapidly and about 100 million will travel the world in 2020. In 2009, about 7.8 million foreign tourists visited Korea and the Ministry of Culture, Sports and Tourism is trying to attract 12 million foreign tourists in 2014. A research institute carried out a survey targeting foreign tourists and the survey results showed that they felt uncomfortable with communication (about 55.8%) and directional signs (about 21.4%) when they traveled in Korea. To solve this inconvenience for foreign tourists, multilingual servicesfor traffic signs, tour information, shopping information and so forth should be enhanced. The appearance of the Smartphone comes just in time to provide a new service to address these inconveniences. Smartphones are especially useful because every Smartphone has GPS (Global Positioning System) that can provide users' location to the system, making it possible to provide location-based services. For improvement of tourists' convenience, Seoul Metropolitan Government hasinitiated the u-tour service using Kiosks and Smartphones, and several Province Governments have started the u-tourpia project using RFID (Radio Frequency IDentification) and an exclusive device. Even though the u-tour or u-tourpia service used the Smartphone and RFID, the tourist should know the location of the Kiosks and have previous information. So, this service did not give the solution yet. In this paper, I developed a new convenient service which can provide location based information for the individual tourists using GPS, WiFi, and 3G. The service was tested at Insa-dong in Seoul, and the service can provide tour information around the tourist using a push service without user selection. This self-tour service is designed for providing a travel guide service for foreign travelers from the airport to their destination and information about tourist attractions. The system reduced information traffic by constraining receipt of information to tourist themes and locations within a 20m or 40m radius of the device. In this case, service providers can provide targeted, just-in-time services to special customers by sending desired information. For evaluating the implemented system, the contents of 40 gift shops and traditional restaurants in Insa-dong are stored in the CMS (Content Management System). The service program shows a map displaying the current location of the tourist and displays a circle which shows the range to get the tourist information. If there is information for the tourist within range, the information viewer is activated. If there is only a single resultto display, the information viewer pops up directly, and if there are several results, the viewer shows a list of the contents and the user can choose content manually. As aresult, the proposed system can provide location-based tourist information to tourists without previous knowledge of the area. Currently, the GPS has a margin of error (about 10~20m) and this leads the location and information errors. However, because our Government is planning to provide DGPS (Differential GPS) information by DMB (Digital Multimedia Broadcasting) this error will be reduced to within 1m.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.5
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• pp.545-553
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• 2009

Digital Elevation Models (DEM) is widely used in establishing the topographic profile in nation spatial information. Aerial Light Detection And Ranging (LiDAR) system is one of the well-known means to produce DEM. The system has fast data acquisition procedures and less weather-dependent restrictions compared to photogrammetric approaches. In this regards, LiDAR has been widely utilized and accepted in the process of nation spatial information generation due to its sufficient positional accuracy. However, the investigation of the accuracy of aerial LiDAR data over the area of forestation with various kinds of vegetations has been barely implemented in Korea. Hence, this research focuses on the investigation of the accuracy of aerial LiDAR data over the area of forestation and the evaluation of the acquired accuracy according to the characteristics of the vegetations. The study areas include land with shrubs and its adjacent forest area with mixed tree species. The spots for the investigation have been selected to be well-distributed over the whole study areas and their coordinates are surveyed by Global Positioning Systems (GPS). Then, the surveyed information and aerial LiDAR data have been compared with each other and the result accuracy has been evaluated. Conclusively, it is recommended that LiDAR data collection to be conducted after defoliation period, especially over the areas with broadleaf trees due to the possibility of significant outliers.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2002.04a
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• pp.17-24
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• 2002

Mechanization is the characteristic of the industrial era and computerization is the characteristic of the Information Era. Now we are facing on the transition from Industrial Era to information Era. Established the National Geo-spatial Data Infrastructures is the fundamental base for information society and is one part of the national basic economic development plan. From 1980's China started his successful transition from traditional methods to high-tech based mapping. China has laid out a high accuracy national GPS (global Positioning System) network, and completed the geographic information databases for scale of 1:1million and 1:250,000. Now it is working on the databases for scales of 1:50,000 and 1:10,000, the world highest level. The massive national programmed has been dubbed "Digital China," since it involves massive quantities of digitized geographical information. Simultaneity, GIS technology and the geo-spatial data have been used widely in electronic government affair, environmental protection, disaster control, ITS and etc. The users have realized the benefits more and more widely. Internet is an efficient way to distribute the geo-information, the State Bureau of Surveying and Mapping has give great effort to settle down the rules and standards to establish the clearing house. Some National Geo-standards have issued, and some of them are on the way. The GIS software is another important factor in the GIS industry. Chinese government working-out some good policy to supports the GIS software developer to have their own copyright. This paper is based on the above to introduce the status and development of Geomatics in China. in China.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.12
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• pp.1216-1227
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• 2013

GNSS(Global Navigation Satellite System) is now being widely used in both civilian and military applications where accurate positioning and timing information are required and it is considered as a representative convergence technique in IT-Military application techniques. However, GNSS has low sensitivity level of GNSS receivers and is vulnerable to jamming signal, since the signals come from the satellite located at approximately 20,000 Km above the earth. The studies for the anti-jamming techniques in military applications have been passively performed in the domestic, because the information related GNSS are dependent on the countries that have GNSS. In this paper, we show the effect of jammer ERP by analyzing the link budget of GPS J/S power as a function of distance between jammer and receiver. Also, we categorize the anti-jamming techniques based on the functional block diagram of GNSS receiver structure and analyze the recent anti-jamming GNSS products and their technologies developed in domestic and foreign countries.

• Journal of Information Processing Systems
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• v.7 no.2
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• pp.221-240
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• 2011

Vehicular networks are a promising application of mobile ad hoc networks. In this paper, we introduce an efficient broadcast technique, called CB-S (Cell Broadcast for Streets), for vehicular networks with occlusions such as skyscrapers. In this environment, the road network is fragmented into cells such that nodes in a cell can communicate with any node within a two cell distance. Each mobile node is equipped with a GPS (Global Positioning System) unit and a map of the cells. The cell map has information about the cells including their identifier and the coordinates of the upper-right and lower-left corner of each cell. CB-S has the following desirable property. Broadcast of a message is performed by rebroadcasting the message from every other cell in the terrain. This characteristic allows CB-S to achieve an efficient performance. Our simulation results indicate that messages always reach all nodes in the wireless network. This perfect coverage is achieved with minimal overhead. That is, CB-S uses a low number of nodes to disseminate the data packets as quickly as probabilistically possible. This efficiency gives it the advantage of low delay. To show these benefits, we give simulations results to compare CB-S with four other broadcast techniques. In practice, CB-S can be used for information dissemination, or to reduce the high cost of destination discovery in routing protocols. By also specify the radius of affected zone, CB-S is also more efficient when broadcast to a subset of the nodes is desirable.