• Journal of Information Processing Systems
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• v.14 no.6
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• pp.1445-1456
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• 2018

Environment perception and three-dimensional (3D) reconstruction tasks are used to provide unmanned ground vehicle (UGV) with driving awareness interfaces. The speed of obstacle segmentation and surrounding terrain reconstruction crucially influences decision making in UGVs. To increase the processing speed of environment information analysis, we develop a CPU-GPU hybrid system of automatic environment perception and 3D terrain reconstruction based on the integration of multiple sensors. The system consists of three functional modules, namely, multi-sensor data collection and pre-processing, environment perception, and 3D reconstruction. To integrate individual datasets collected from different sensors, the pre-processing function registers the sensed LiDAR (light detection and ranging) point clouds, video sequences, and motion information into a global terrain model after filtering redundant and noise data according to the redundancy removal principle. In the environment perception module, the registered discrete points are clustered into ground surface and individual objects by using a ground segmentation method and a connected component labeling algorithm. The estimated ground surface and non-ground objects indicate the terrain to be traversed and obstacles in the environment, thus creating driving awareness. The 3D reconstruction module calibrates the projection matrix between the mounted LiDAR and cameras to map the local point clouds onto the captured video images. Texture meshes and color particle models are used to reconstruct the ground surface and objects of the 3D terrain model, respectively. To accelerate the proposed system, we apply the GPU parallel computation method to implement the applied computer graphics and image processing algorithms in parallel.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.854-856
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• 2014

Has been released of make it possible to control the using for smart devices of a wide variety home appliances and electronics in smart appliances in accordance with the one person multi devices. In addition, is increasing rapidly for the number of the product on cleaning robot and refrigerator, air conditioning, TV, etc. these devices are using the implement up DLNA system. And at home and abroad for development and has provided with Iot and Alljoyn such systems. But currently using home appliances or electronic devices of there are a lot of the operating system non installed than the installed products. In addition, smart appliances do not use for user than buying existing electronic products a lot more. In addition, more occur for smart appliances of that do not use for the user on smart appliances rather than buying existing electronics. In this paper, Suggested and implemented for system of control such as smart devices to existed home appliance on not have an operating system, Using mobile device for want users to quantify the data to transfer from arduino board.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.329-335
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• 2018

Satellite images, which are widely used in various applications, are very useful for monitoring the surface of the earth. Since satellite data is obtained from a remote sensor, it contains a lot of noise and errors depending on observation weather conditions during data acquisition and sensor malfunction status. Since the accuracy of the data affects the accuracy and reliability of the data analysis results, noise removal and data restoration for high quality data is important. In this study, we propose a reconstruction system that models the time dependent dynamic characteristics of satellite data using a multi-period harmonic model and performs adaptive data restoration considering the spatial correlation of data. The proposed method is a real-time restoration method and thus can be employed as a preprocessing algorithm for real-time reconstruction of satellite data. The proposed method was evaluated with both simulated data and MODIS NDVI data for six years from 2011 to 2016. Experimental results show that the proposed method has the potentiality for reconstructing high quality satellite data.

• The Journal of the Korea Contents Association
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• v.12 no.4
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• pp.60-68
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• 2012

In recent years, the requirements on the high quality environment monitoring by using the sensor nodes which can handle the multimedia data in WSN have been increased. However, because the volume of multimedia data is tremendous, the limited bandwidth of a wireless channel may incur the bottleneck of a system. To solve such a problem, most of the existing distributed multi-path routing protocols based on multimedia data just focused on overcoming the limited bandwidth in order to enhance the energy efficiency and the transmission rate. However, because the existing methods can not apply a key-based technique to encrypt the multimedia data, they are very weak for the security. In this paper, we propose a secure disjointed multipath routing scheme for multimedia data transmission. Since our proposed scheme divides multimedia data(eg. image) into pixels and sends them through disjointed multipath routing, it can provide security to the whole network without using the key-based method. Our experimental results show that our proposed scheme reduces about 10% the amount of the energy consumption and about 65% the amount of the missed data packets caused by malicious nodes over the existing methods on average.

• Journal of Korea Water Resources Association
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• v.48 no.5
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• pp.409-423
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• 2015

In this study the very short-term rainfall forecasting and storm water forecasting using the weather radar data were implemented in an urban stream basin. As forecasting time increasing, the very short-term rainfall forecasting results show that the correlation coefficient was decreased and the root mean square error was increased and then the forecasting model accuracy was decreased. However, as a result of the correlation coefficient up to 60-minute forecasting time is maintained 0.5 or higher was obtained. As a result of storm water forecasting in an urban area, the reduction in peak flow and outflow volume with increasing forecasting time occurs, the peak time was analyzed that relatively matched. In the application of storm water forecasting by radar rainfall forecast, the errors has occurred that we determined some of the external factors. In the future, we believed to be necessary to perform that the continuous algorithm improvement such as simulation of rapid generation and disappearance phenomenon by precipitation echo, the improvement of extreme rainfall forecasting in urban areas, and the rainfall-runoff model parameter optimizations. The results of this study, not only urban stream basin, but also we obtained the observed data, and expand the real-time flood alarm system over the ungaged basins. In addition, it is possible to take advantage of development of as multi-sensor based very short-term rainfall forecasting technology.

• Journal of the Korea Society for Simulation
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• v.19 no.2
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• pp.73-80
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• 2010

A wireless sensor network which is deployed in hostile environment can be easily compromised by attackers. The selective forwarding attack can jam the packet or drop a sensitive packet such as the movement of the enemy on data flow path through the compromised node. Xiao, Yu and Gao proposed the checkpoint-based multi-hop acknowledgement scheme(CHEMAS). In CHEMAS, each path node enable to be the checkpoint node according to the pre-defined probability and then can detect the area where the selective forwarding attacks is generated through the checkpoint nodes. In this scheme, the number of hops is very important because this parameter may trade off between energy conservation and detection capacity. In this paper, we used the fuzzy rule system to determine adaptive threshold value which is the number of hops for the ACK packets. In every period, the base station determines threshold value while using fuzzy logic. The energy level, the number of compromised node, and the distance to each node from base station are used to determine threshold value in fuzzy logic.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.295-299
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• 2007

Today, ubiquitous technology (e.g. computers or networked devices pervade everywhere we are) has enlarged by great advancement of information and communication technologies. If ubiquitous technologies is applied to, innovation of spatial information technology is expected. traditional spatial information technologies such as survey, GIS, GPS, LBS, and RS and ubiquitous technology gradual1y have been converged. The aim of this study is to create shared visions in spatial information technologies by scenario based roadmapping. So, we surveyed the state of the art in main spatial information technologies, market status and patent map. Consequently, prospects of spatial information technologies is suggested. The aim of 1st and 2nd NGIS project focused on map supplier was to develop digital map(e.g. framework data, various thematic map). As a result, the best technology of digital mapping is achieved in the world. But, there is not enough to develop GIS and LBS solution. Current market in GIS S/W and Telematics is about 384billon won and 250billion won. a patent is applied in the order, like a USA(1571case, 47%), Japan(883case, 26%), EU(478case, 14%), Korea(446case, 13%). In the future, spatial information technology fused on ubiquitous technology will be focused on user's demand and developing convenience context. The developing target will be realtime monitoring of 3D spatial data based on high resolution coordinate system, sharing and supplying multi-sensor data considered users demand, location service by ubiquitous technologies.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.415-418
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• 2006

다양한 데이터에 대해 정확한 분석이 요구되는 분야가 증가하면서, 데이터를 효율적으로 가시화하는 방법에 대한 요구도 증가하고 있다. 분석에 효율적인 가시화란 데이터의 특성을 잘 표현함으로써 분석가가 데이터를 직관적으로 이해할 수 있도록 도와주는 것을 말한다. 이를 통해 데이터를 분석하는 시간을 줄이고 정확한 결과를 얻는데 도움을 준다. 본 논문에서는 가스 배관을 검사하기 위한 Geometry 피그（PIG:Pipeline Inspection Gauge)와 MFL 피그로부터 얻어지는 데이터를 다양한 방법으로 가시화하고 분석에 효과적인 가시화와 시스템의 구현에 대해 다룬다. 각 피그의 다중 센서를 통해 얻어온 데이터를 Line graph, Pseudo Color Image, 3D Surface, Polar View, 3D Pipeline View와 같은 다양한 방법으로 가시화하고 view들 간의 동기화 및 사용자 지정 view 배치를 통해 빠르고 정확한 분석을 가능하게 하는 여러 가지 방법에 대해 설명한다.

• Journal of Sensor Science and Technology
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• v.26 no.3
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• pp.214-222
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• 2017

In this study, the effects of internal heat treatment associated sintering temperatures were simulated by the Finite Element Method (FEM). The sintering mechanism of pulsed current activated sintering process (PCAS) is still unclear because of some unexplainable heat transfer phenomena in coupled multi-physical fields, as well as the difficulty in measuring the interior temperatures of metal powder. We have carried out simulation study to find out thermal distributions between graphite mold and Ruthenium powder prior to PCAS process. For PCAS process, heating rate was maintained at $100^{\circ}C/min$ the simulation indicates that the sintering temperature range was between $1000^{\circ}C$ to $1300^{\circ}C$ under 60 MPa. The heat transfer inside the Ruthenium sintered-body sample was modelled through the whole process in order to predict the minimum interior temperature. Thermal simulation shows that the interior temperature gradient decreased by graphite punch length and calculation results well agreed with the PCAS field test results.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.250-252
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• 2007

본 논문에서는 Multi-stage Electro-magnetic Launcher(EML)를 개발함에 있어, Photo Sensor Switching System을 구성하여 Reluctance type의 2-Stage Coilgun을 설계, 제작하였다. 이를 위해, 솔레노이드 코일의 최적 aspect ratio와 발사체의 size를 F.E.M. 해석을 통해 결정하였고, 탄속측정기를 제작하여 실험을 통해 각 stage의 최적 시정수를 결정하였다.