• Journal of the Korean Society of Manufacturing Process Engineers
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• 제6권1호
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• pp.7-12
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• 2007

The optic industry is a high value-added advanced technology industry combined with the precision machine industry and the digital electronics industry. The aspheric lens, one of optic parts, is a key technology having a significant influence on the performance of optic equipment. So this study relates to designing an aspheric lens to which a ray-tracing method is applied. In the ray-tracing method, a refractive index of material is used, which take an advantage that the location of a light source and incident angle can be fixed, unlike the ray back-tracing scheme.

• Journal of the Korean Society for Precision Engineering
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• 제20권10호
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• pp.191-198
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• 2003

In this study, aberration free aspherical lens design method named ray reverse tracing method is introduced. Differently from the traditional design method, the ray reverse tracing method traces the shape and location of a real object by use of its virtual image. From the result, especially spherical aberration free aspherical lens could be designed by use of the ray reverse tracing method. Furthermore, it could reduce the degree of dependence of optical characteristics on designer's ability, because deformation terms and optimization can be eliminated, which has been performed in conventional lens design process.

• Convergence Security Journal
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• 제8권3호
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• pp.73-81
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• 2008

We can find easily about researches or technical development that deal with grasping the location of an object with GPS(Global Positioning System) in order to use them as a useful information. Most researches or technical development on application of tracing have been developed for the purpose of tracing objects in broad area as physical distribution or transportation, but recently, there are many researches on tracing materials in premise area as a fork lift, carts, or the equipment of work. In general, a system that utilizes location information of objects needs data communication network to transmit location data and it ensures data communication network by using common networks(SK, LG, KFT) or wireless LAN. However these two methods need monthly payment for the rental fee or require considerable amount of investment for the early stage so it is difficult to use them merely for tracing premise subjects. This study was conducted to build a tracing system for premise area by local area RF relay algorithm with low cost applying RF relay algorithm to local area wireless communication(ZIGBEE, 424MHz, Bluetooth, 900MHz) system in order to supplement these demerits and included relay algorithm, RF locating information terminal, local area RF gab-fillers, a plan for collection server of locating information, and the way of realization as they are needed in this system. I consider that this study would be applicable with flexibility in the industry area that needs tracing solution within a specific area or needs ensuring data communication network, to transmit data in ubiquitous environment, by easier and more rapid way with lower cost.

• Journal of Korea Water Resources Association
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• 제50권9호
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• pp.609-616
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• 2017

In this study, algorithm for the selecting the optimum monitoring location and leakage detection algorithm based on back tracing calculation method were developed and verified by the experiments in pilot plant of water distribution system. First of all, optimum monitoring locations were selected and pressure changes were measured due to artificial leakage by pressure gauges in pilot plant. Simulations of leakage detection was performed for the verification of back tracing calculation method as a leakage detection method. From the results, it was found that leakage locations and leakage amount were exactly estimated. Various leakage amount from $0.0005m^3/s$ to $0.0018m^3/s$ were reproduced and leakage location was detected by back tracing calculation method. It was verified that back tracing calculation method as a leakage detection method is effective.

• Journal of the Society of Naval Architects of Korea
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• 제43권1호
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• pp.87-95
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• 2006

There are hundreds of ship blocks which are under the block assembly, painting, and outfitting assembly works in the pre-erection shops of shipyard. Generally, each block is planned to be processed in a pre-erection shop according to the block type by the long-term production-scheduling before six months. However, many blocks can't be processed in the planned time and the planned shop since the before and after block-processing changes or delays the planned sequential works in pre-erection shops. Therefore, it is essential to monitor the current location of each block and work in process to cope with the changed situation of pre-erection shops. Present study integrates PDA, GPS, and CDMA not only to chase the location of each block but also to exchange the pre-erection work order and the work report between the production-scheduling server and the production managers in the pre-erection shops. This study shows a prototype for the block tracing and process monitoring in the pre-erection shops.

• Journal of KSNVE
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• 제10권2호
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• pp.240-246
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• 2000

One of the widely accepted methods for evaluating the interior sound quality of automobiles is Articulation Index(AI). The AI actually measures the articulation level of the sound in the vehicle cabin as passengers talk to one another. In this study, the effect of two different absorption materials inside the cabin on AI has been investigated by ray-tracing method : one is firewall, the other is celling. It turns out that the back seat location is found to be strongly dependent on the type of absorption materials treated at the celling, since the sound absorbing area is different due to the location and the firewall is situated in the "Reverberation Radius". The proposed methdo could be used to improve the sound quality of automobiles at the design stge.sign stge.

• Proceedings of the KSRS Conference
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• 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
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• pp.290-295
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• 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 Optical Society of Korea
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• 제20권1호
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• pp.118-124
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• 2016

The shape and location of the cutoff shield in a projection-type headlight system were optimized by a ray-tracing technique. A shield based on a Petsval surface showed better cutoff characteristics than a flat or cylindrical shield, such as a sharp intensity gradient and less color separation at the cutoff line. Adjustment of the shield’s location between the reflector and the aspheric lens further improved its cutoff characteristics.

• Proceedings of the Korean Society of Computer Information Conference
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• 한국컴퓨터정보학회 2012년도 제45차 동계학술발표논문집 20권1호
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• pp.15-17
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• 2012

최근 들어 스마트폰이 급격하게 보급됨에 따라 스마트폰을 이용하여 상대방의 위치를 확인하는 응용 프로그램이 많이 개발되고 있다. 현재 운영중인 위치 추적 서비스는 두 사람이 스마트폰을 소지하고 있는 경우의 서비스 형태와 한 사람만 스마트폰을 소지하고 있는 경우의 서비스 형태로 분류된다. 우리는 스마트폰과 스마트폰 간의 위치 정보 교환을 통해 상대방의 위치를 찾는 방식이 아닌 스마트폰과 GPS모듈 간의 위치 정보 교환을 통하여 어린이나 애완견의 위치를 찾을 수 있도록 GPS 모듈을 개발하고 이 모듈과 통신하는 스마트폰 앱을 개발하였다. 개발된 GPS 모듈은 위치 정보를 받아 전달하는 기능만 가지므로 스마트폰에 비해 매우 저렴하게 구성할 수 있어서 적은 경비로 상대방을 찾을 수 있으며 공중망 대신 무선랜 망을 통해 위치정보를 전달하게 설계되어 추가적인 통신 비용이 들지 않는 장점을 가진다. 하지만 위치추적 서비스가 무선랜 망이 구축된 제한된 구역에서만 가능하다는 단점이 있다. 개발된 위치추적 서비스 방식은 시장이나 놀이공원 같은 특수한 지역에서 유용하게 사용될 수 있을 것으로 생각된다.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제27권1B호
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• pp.114-124
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• 2002

In this paper, we proposed the image-based 3D ray tracing indoor propagation model using a patch scattering model for fading analysis of indoor propagation environments. An image-based 3D ray tracing technique is mainly used, which allows the rapid generation of the complex channel impulse response for any given location and polarization of transmitter and receiver. Due to the site specific nature of indoor environment, we took into account the location and the electrical properties of individual walls and objects such as windows, doors and plaster board in our propagation model. Besides, the 3D radiation beam-patterns and polarizations of arbitrary antennas were considered, and using patch scattering model we can consider the change of the polarization due to the scattering from the various indoor objects, like desks, chairs and etc. the are almost impossible to be modeled with the basic image-based ray tracing method. The model will predict the impulse response, the rms delay spread, the fading characteristics of the channel and performances of the polarization diversity schemes.