• Journal of Applied Reliability
• /
• 제8권4호
• /
• pp.181-192
• /
• 2008

In this paper, we proposed effective algorithm that do Availability of communication network account using total probability formula. Use path tracing method about PSTN linked with MSC in WCDMA considering occasion that do not consider mobility of terminal and Availability did account. First, express minimum path series gathering by structure function after network that do modeling by stochastic graph for communication network saves all minimal path sets between particular two abutments and we gain Availability value in angular variable after express structure function by Boolean operation form and Availability between two abutments did account.

• Proceedings of the KSRS Conference
• /
• 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
• /
• pp.290-295
• /
• 1999

Lineament extraction from mountain area often provides valuable geological information. In many cases, the lineaments correspond to a series of continuous large valleys. This paper introduces a new lineament extraction method from Digital Elevation Model (DEM) using Raindrop Tracing Algorithm (RTA). The main advantage of this algorithm over conventional Segment Tracing Algorithm (STA) is that it utilizes DEM directly unlike the STA Which utilizes the shaded relief of DEM. The RTA simulates the real life of raindrops that converge into a large valley. The simulation has been done by sprinkling the randomized raindrops over DEM and counting the number of raindrop path that follows the negative gradient of the DEM. The large counting number indicates the location of a big valley where the raindrops converge. With the help of the counting number array (accumulator array) recording the flowing path information, RTA can produce perfectly unbiased binary image of the lineament.

• Journal of the Korean Institute of Telematics and Electronics
• /
• 제25권7호
• /
• pp.734-745
• /
• 1988

In this paper, it is tried to improve efficiency of the D-algorithm by assigning the logic values effectively on the nodes related to the critical path for back tracing to reduce the number of search nodes when acyclic combinational logic circuits are composed of NAND gates only. For that purpose, LASAR algorithm which is suitable for determining a critical path for back tracing is applied to the D-algorithm and it is implemented by IBM-PC with APL language. The test results on a number of NAND circuits which have multi-fanout, reconvergent and symetric characteristics show that the modified D-algorihtm reduces the number of search nodes in forward and backward tracing and decreases the run time of CPU about 10 percents.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• 제48권5호
• /
• pp.636-642
• /
• 1999

The synthesis of the 3D images is the most important part of the virtual reality. The ray tracing is the best method for reality in the 3D graphics. But the ray tracing requires long computation time for the synthesis of the 3D images. So, we implement the ray tracing with software and hardware. Specially we design the hit-test unit with FPGA tool for the ray tracing. Hit-test unit is a very important part of ray tracing to improve the speed. In this paper, we proposed a new hit-test algorithm and apply the parallel architecture for hit-test unit to improve the speed. We optimized the arithmetic unit because the critical path of hit-test unit is in the multiplication part. We used the booth algorithm and the baugh-wooley algorithm to reduce the partial product and adapted the CSA and CLA to improve the efficiency of the partial product addition. Our new Ray tracing processor can produce the image about 512ms/F and can be adapted to real-time application with only 10 parallel processors.

• Journal of Communications and Networks
• /
• 제11권6호
• /
• pp.589-598
• /
• 2009

In wireless sensor networks, a node that reports information gathered from adjacent assets should relay packets appropriately so that its location context is kept private, and thereby helping ensure the security of the assets that are being monitored. Unfortunately, existing routing methods that counter the local eavesdropping-based tracing deal with a single asset, and most of them suffer from the packet-delivery latency as they prefer to take a separate path of many hops for each packet being sent. In this paper, we propose a routing method, greedy perimeter stateless routing-based source-location privacy with crew size w (GSLP-w), that enhances location privacy of the packet-originating node (i.e., active source) in the presence of multiple assets. GSLP-w is a hybrid method, in which the next-hop node is chosen in one of four modes, namely greedy, random, perimeter, and retreat modes. Random forwarding brings the path diversity, while greedy forwarding refrains from taking an excessively long path and leads to convergence to the destination. Perimeter routing makes detours that avoid the nodes near assets so that they cannot be located by an adversary tracing up the route path. We study the performance of GSLP-w with respect to crew size w (the number of packets being sent per path) and the number of sources. GSLP-w is compared with phantom routing-single path (PR-SP), which is a notable routing method for source-location privacy and our simulation results show that improvements from the point of the ratio of safety period and delivery latency become significant as the number of source nodes increases.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• 제41권12호
• /
• pp.1942-1949
• /
• 2016

This paper proposed automatic path-tracing methods for Flying Disc Golf by adopting IoT comcepts at smart-marker. We tried to implement service system by making database. Smart-marker's configurations & roles are proposed. By making test-boards and adoption to various Flying Disc Golf games, the efficiency is proved. The positions and distances captured by the smart-marker are transferred to the smart-pole per each hole. The smart-pole captured them and transfers to web-server which is databased them. The result can be searched by web or smartphone in real time.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• 제7권4호
• /
• pp.736-742
• /
• 2003

This paper presents the propagation path loss in a tunnel which is a kinds of underground environments. To predict propagation path loss more accurately, we choose a straight tunnel with rectangular cross-section. The simulated receiver powers that are using a hybrid waveguide model and a Ray-Tracing method, are compared with the measured ones as a function of distance between TX and RX antennas in tunnel. The attenuation value of regression analysis for measured power in the tunnel is 0.0238dB/m which is similar to the one of the EH1.2 mode, 0.0246dB/m in hybrid waveguide model. By comparing simulation with measurement in tunnels, it has been shown that the measured values are approximate to the simulated results of ray-tracing model. In the analysis of wide-band channel characteristics of the tunnel, the more the distance between TX and RX antennas in tunnel increases, RMS delay spread increases and coherence bandwidth decreases.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2002년도 ICCAS
• /
• pp.108.1-108
• /
• 2002

This paper is willing to propose a method of wall tracing, a moving algorithm between two points, when a Cleaning robot between two points moves. We use the information about obstacles and wall side in calculating different weight vector the each infrared sensors in cleaning robot. Therefore the cleaning robot navigates the wall. In the algorithm of wall tracing, the value of error in angle and distance between starting point and ending point should be zero to navigate the wall safely. The propriety of algorithm of the wall tracing is simulated as this method by using Visual C++. The result simulated proved to the simulation.

• Journal of Advanced Navigation Technology
• /
• 제11권4호
• /
• pp.454-460
• /
• 2007

In this paper, we implemented a ray-tracing simulator with a ray-launching technique and generated the propagation path of each ray in an multiple-wall indoor environment. In this simulator, we adopted two dimension ray-tracing techniques considering the reflection and penetration were dominant propagation factor in the indoor channel. From the result, we verified that this ray-tracing simulator shows the similar pattern and delay distribution with the experiment results of the previous research.

• Journal of electromagnetic engineering and science
• /
• 제1권1호
• /
• pp.30-36
• /
• 2001

Whereas it is well known that microwave propagation around corners of urban area is estimated well by the uniform geometrical theory of diffraction (UTD), it is not clear how much depolarization occurs at a given receiver position and how much transmission through walls affects to total path loss. This paper presents the results of the ray tracing simulation to answer these questions. Simulations of microwave propagation around corners were performed for various line-of-sight (LOS) and out-of-sight(OOS) positions of a receiver, by summing the electrical fields of reflected, diffracted and transmitted rays coherently. Since height difference between transmitter and receiver, as well as ground plane, causes depolarization, the ray tracing simulation estimates the cross-polarization coupling. It was found that the cross-polarization coupling decreases as receiver moves away from transmitter. Another part of the study focused on the signal transmitted through building walls of the corner. It was found that the transmitted field is dominant at OOS region when the conductivity of the walls is low (for example, lower than 0.0l S/m). The simulation results of the ray tracing technique in this study agreed well with an experimental measurement around corners.