• Journal of the Korea Institute of Military Science and Technology
• /
• v.13 no.2
• /
• pp.313-319
• /
• 2010

GNSS receiver which uses the weak satellite signal is very vulnerable to the intentional jamming or non-intentional electromagnetic interference. One of the best method to overcome this disadvantage is to use an adaptive array antenna which has the capability of beamforming or nulling to the certain direction. In this paper, the performance of spatial adaptive null pattern control algorithm of 5 element array antenna is analyzed. A control algorithm which is designed in the 5 element array antenna is OPM(Output Power Minimization) which is eliminating the correlation characteristics between a reference antenna and the others. This algorithm can be applied effectively to the satellite navigation's CRPA because the satellite direction is not considered and GNSS signal power is below the thermal noise. The feature of the OPM algorithm is analyzed and the performance is compared with other null pattern control algorithm.

• Spatial Information Research
• /
• v.4 no.2
• /
• pp.159-179
• /
• 1996

The objective of the paper is to recommend a database format of geographic informa¬tion systems for transportation (GIS-T) based on a review of geographic data files (GDF), a European standard format for navigation and the topologically integrated geographic encoding and referenc¬ing files (TIGER) if the USA The establishment of the standard format for transportation database is important for sharing data since data collection is costly. We believe the recommended format would reduce the implementation costs for GIS-T in Korea in the future.

• The Journal of Korea Robotics Society
• /
• v.9 no.2
• /
• pp.96-103
• /
• 2014

Global localization is one of the essential issues for mobile robot navigation. In this study, an indoor global localization method is proposed which uses a Kinect sensor and a monocular upward-looking camera. The proposed method generates an environment map which consists of a grid map, a ceiling feature map from the upward-looking camera, and a spatial feature map obtained from the Kinect sensor. The method selects robot pose candidates using the spatial feature map and updates sample poses by particle filter based on the grid map. Localization success is determined by calculating the matching error from the ceiling feature map. In various experiments, the proposed method achieved a position accuracy of 0.12m and a position update speed of 10.4s, which is robust enough for real-world applications.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2010.04a
• /
• pp.207-208
• /
• 2010

In this paper, we carried out calibration of laser scanning MMS(Mobile Mapping System) using Lynx Mobile Mapper, a new MMS developed at Optech Incorporated. Laser scanning MMS could be defined as an integration of several subsystems. Subsystems are composed of laser scanner, gps receiver and antenna, INS(Inertial Navigation System), DMI(Distance Measurement Instrument). These are obtained 3D spatial information by direct-georeferencing technology. To obtain 3D spatial information, calibration of laser scanning MMS is required prior to operation system, it is similar to airborme lidar system. 145 checkpoints were used to accuracy estimation. The accuracy results are about 5cm(RMSE) for calibration in all directions(east, north, ellipsoidal height).

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.5
• /
• pp.1166-1176
• /
• 1999

The spationtemporal databases support a historical informations as well as spatial managements for various kinds of objects in the real world, and can be efficiently used in many applications such as geographic information system, urban plan system, car navigation system. However it is difficult to represent efficiently historical operations with conventional database query language for spatial objects. In terms of cost for query processing, it also degenerates performance of query processing because of syntactic limitations which is innate in conventional query representation. So in this paper, we introduce a new query language, entitled as STQL, which has been extended on the basis of the most popular relational database query language SQL. And we implement as well as evaluate a spationtemporal query processing system that get a query written by STQL and then process it in a main memory.

• Advances in robotics research
• /
• v.2 no.3
• /
• pp.219-236
• /
• 2018

This research focuses on controlling robots and their formations using rough mereology as a means for spatial reasoning. The authors present the state of the art theory behind path planning, robot cooperation domains and ways of creating robot formations. Furthermore, the theory behind Rough Mereology as a way of implementing mereological potential field based path creation and navigation for single and multiple robots is described. An implementation of the algorithm is shown in simulation using RoboSim simulator. Five formations are tested (Line, Rhomboid, Snake, Circle, Cross) along with three decision systems (First In, Leader First, Horde Mode) as compared to other methods.

• Journal of Korean Neurosurgical Society
• /
• v.65 no.4
• /
• pp.489-498
• /
• 2022

Spatial insight into intracranial pathology and structure is important for neurosurgeons to perform safe and successful surgeries. Three-dimensional (3D) printing technology in the medical field has made it possible to produce intuitive models that can help with spatial perception. Recent advances in 3D-printed disease models have removed barriers to entering the clinical field and medical market, such as precision and texture reality, speed of production, and cost. The 3D-printed disease model is now ready to be actively applied to daily clinical practice in neurosurgical planning, simulation, and training. In this review, the development of 3D-printed neurosurgical disease models and their application are summarized and discussed.

• 한국공간정보시스템학회:학술대회논문집
• /
• 2007.06a
• /
• pp.324-328
• /
• 2007

텔레매틱스 분야에서 가장 널리 서비스되고 있는 내비게이션 시스템의 최신 동향은 주행중 운전자의 정보 인지를 쉽게 하도록 하는 것이다. 실감 내비게이션 기술은 운전자의 시야와 동일한 전방 영상을 카메라로부터 획득하여 운전자에게 필요한 정보를 그 위에 오버레이하여 직접 전달하는 기술이다. 이러한 실감 내비게이션을 위하여 기존 방식과는 다른 빠르고 효과적인 정보전달 방식이 필요하며, 어떤 정보를 사용자에게 어떻게 전달하느냐에 따라 다른 효과를 가져올 수 있다. 본 논문에서는 실감 내비게이션에서의 정보 표현을 위한 화면 배치, 가상객체의 디자인 안, 정보량의 적정수준 등 디자인 방향과 고려사항을 논의하고 사용자 평가에 의한 디자인 최적 대안을 제시한다.

• 한국공간정보시스템학회:학술대회논문집
• /
• 2007.06a
• /
• pp.188-193
• /
• 2007

본 논문에서는 실사영상을 기반으로 동작하는 내비게이션에서 핵심적인 역할을 담당하고 있는 모듈 가운데 하나인 도로객체인식 모듈의 기능에 대해서 살펴보고자 한다. 이 모듈은 기존의 맵 기반의 내비게이션에서 찾아볼 수 없는 부분이며, 실사 영상위에 차량의 경로를 안내하기 위해서는 이 모듈을 통해 다양한 도로객체를 인식해야 하는데, 주행차선인식, 주행차로인식 및 신호등 인식이 필요하며 경우에 따라서는 건물인식이 여기에 포함될 수 있다.

• Spatial Information Research
• /
• v.15 no.4
• /
• pp.385-395
• /
• 2007

As the growth of performance of the computer and the development of the Internet are exponential, sharing and using the information illegally have also increased to the same proportion. In this paper, we proposed a novel method on the vector map data among digital contents. Vector map data are used for GIS, navigation and web-based services etc. We embedded watermark into the coordinate of the vector map data using bit operation and extracted the watermark. This method helps to protect the copyright of the vector map data. This watermarking method is a spatial domain method and it embeds the watermark within an allowable error. Our experiment shows that the watermark produced by this method is resistant to simplification and translation.