• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권7호
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• pp.3733-3755
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• 2019

E-cash has its merits comparing with other payment modes. However, there are two problems, which are how to achieve practical/complete tracing and how to achieve it in compact E-cash. First, the bank and the TTP (i.e., trusted third party) have different duties and powers in the reality. Therefore, double-spending tracing is bank's task, while unconditional tracing is TTP's task. In addition, it is desirable to provide lost-coin tracing before they are spent by anyone else. Second, compact E-cash is an efficient scheme, but tracing the coins from double-spender without TTP results in poor efficiency. To solve the problems, we present a compact E-cash scheme. For this purpose, we design an embedded structure of knowledge proof based on a new pseudorandom function and improve the computation complexity from O(k) to O(1). Double-spending tracing needs leaking dishonest users' secret knowledge, but preserving the anonymity of honest users needs zero-knowledge property, and our special knowledge proof achieves it with complete proofs. Moreover, the design is also useful for other applications, where both keeping zero-knowledge and leaking information are necessary.

• 대한치과기공학회지
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• 제2권1호
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• pp.25-27
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• 1980

In the process of arranging artificial teeth the simple atracing technique was shown to be more precise and convenient for general use in dental clinic than gothic arch tracing. The simple tracing technique had some advantages over other ones in that they were very useful to check protrusive, lateral and central occlusion of mandible movement, and it was very easy to transfer the oral condition and mandible movements precisely onto the articulator. Also the technique was more effective than when using wax bite in that the functional movement range has shifted to 0.2 - 0.4mm form central occlusion.

• 반도체디스플레이기술학회지
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• 제21권4호
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• pp.23-26
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• 2022

In this paper, our ray tracing hardware is implemented on the latest high-capacity FPGA board. The system included ray tracing hardware for rendering and tree building hardware for handling dynamic scenes. The FPGA board used in the implementation is a Xilinx Alveo U250 accelerator card for data centers. This included 12 ray tracing hardware cores and 1 tree-building hardware core. As a result of testing in various scenes in Full HD resolution, the FPS performance of the proposed ray tracing system was measured from 8 to 28. The overall average is about 17.7 FPS.

• 한국항행학회논문지
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• 제11권4호
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• pp.454-460
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• 2007

본 논문에서는 실내 환경에서 전파의 전달특성을 모델링하기 위해 광선추적법을 이용한 2차원 ray-tracing 시뮬레이터를 구현하였고, 이를 통해 다중 벽면으로 구성된 환경에서 ray의 전파 경로를 분석하고 평가하였다. 실험 결과, 구현된 광선추적법의 경로 패턴 및 시간지연 분포는 동일한 무선 환경에서 수행된 이전의 실험 결과와 비슷한 결과가 나타남을 확인하였으며, 송수신 거리 및 방사각에 따른 수신반경의 조절이 타당함을 확인하였다. 특히 비가시거리 송수신 환경에서 다중 벽면을 투과한 ray가 반사와 투과를 형성하여 수신기에 도달할 때까지의 channel profile은 기존 연구의 실험 결과와 유사함을 확인하였다.

• 한국정밀공학회지
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• 제32권1호
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• pp.75-81
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• 2015

Modeling and analysis using a ray tracing method for internal defects were described. Reflection and refraction of rays on the interface of defects were modeled using the Harvey model and the Lambertian model. The diffraction on the interface of defects affected the incoming signals and it could evaluate any defects in the matter and its signal would be analyzed with the ray tracing simulation. The simulation results were compared with actual detecting signals and the ray tracing model was shown in good agreement with experimental data. This method has a possibility to be used as wave propagation modeling in non-destructive testing.

• 한국한의학연구원논문집
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• 제12권3호통권18호
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• pp.31-47
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• 2006

Nowadays Korean governments use Information Technology to improve the quality of life for a people. One of these tries is building the Food Tracing System based on Information Technology. Koreans have big concern about food that is good for health. The Food Tracing System means that the system can follows, traces, and records every steps of production and delivery of food and its ingredient. And this process should be identified and grouped by using tags, marks, and other methods. For example, producer of ingredient, processing steps of food, delivered place could be traced. In addition to food, medical herbs need consumer's trust in production and delivery. To trace and prosecute contaminated medical herbs, medical herbs also need this kind of Tracing System based on Information Technology. This study shows current medical herbs tracing ways and RFID(Radio Frequency IDentification) technology trend. As preceding study for future RFID based medical herbs tracing system, this study suggests the building plan and scenario of the Medical Herbs Tracing System. The determination of the main body for sticking RFID Tags is very important to design for RFID Traceability System. In this study, the starting point of information to medical herbs is an inspection agency. The Medical Herbs to product domestically or import moved to an inspection agency. An inspection agency bond the RFID Tags to packing of the Medical Herbs after examining the a basic its component. At the same time inspector give the information of production or importation to the Tags. This Tags are moved for logistical process to end point, the Korean medicine agency. The customer confirmed the traceability and certification information of the Medical Herbs. For success tracing of medical herbs, institutional support and close cooperation between related organizations is necessary besides good system design.

• IEIE Transactions on Smart Processing and Computing
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• 제4권2호
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• pp.65-70
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• 2015

In this paper, we describe the world's first real-time ray-tracing chip architecture. Ray-tracing technology generates high-quality 3D graphics images better than current rasterization technology by providing four essential light effects: shadow, reflection, refraction and transmission. The real-time ray-tracing chip named RayChip includes a real-time ray-tracing graphics processing unit and an accelerating tree-building unit. An ARM Ltd. central processing unit (CPU) and other peripherals are also included to support all processes of 3D graphics applications. Using the accelerating tree-building unit named RayTree to minimize the CPU load, the chip uses a low-end CPU and decreases both silicon area and power consumption. The evaluation results with RayChip show appropriate performance to support real-time ray tracing in high-definition (HD) resolution, while the rendered images are scaled to full HD resolution. The chip also integrates the Linux operating system and the familiar OpenGL for Embedded Systems application programming interface for easy application development.

• 한국군사과학기술학회지
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• 제15권1호
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• pp.46-56
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• 2012

Traitor Tracing schemes are broadcast encryption systems where at least one of the traitors who were implicated in the construction of a pirate decoder can be traced. This traceability is required in various contents delivery system like satellite broadcast, DMB, pay-TV, DVD and so on. In this paper, we propose a public key traitor tracing scheme with key-update method. If the system manager can update a secret key which is stored in an authorized decode, it makes a pirate decoder useless by updating a secret key A pirate decoder which cannot update a secret key does not decrypt contents in next session or during tracing a traitor, this scheme has merits which will make a pirate decoder useless, therefore this scheme raises the security to a higher level.

• 한국기계가공학회지
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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.

• 정보보호학회논문지
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• 제30권6호
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• pp.1151-1166
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• 2020

COVID-19 감염 확산을 효과적으로 막기 위해 최근 ICT 기술을 기반으로 하는 접촉자 추적 기술이 사용되고 있으며, 이 기술들에는 추적 방식에 따라 다양한 유형이 존재한다. 하지만 이러한 기술들은 항상 보안 위협에 노출되어 있으며 각각의 유형에 따라 발생 가능한 위협도 다양하다. 본 논문에서는 다양한 유형의 접촉자 추적 기술에서 공통적으로 발생하는 프로세스들을 확인하고 이 과정에서 발생할 수 있는 위협을 식별하였다. 이를 통해 다양한 유형의 접촉자 추적 기술 모두에 적용 가능한 공통된 평가 기준을 도출하였으며, 이를 실제 공개된 접촉자 추적 기술에 적용하여 유형 별 비교 분석을 수행하였다. 이러한 연구는 여러 유형 간의 비교를 통해 안전하고 효과적인 접촉자 추적 기술을 선택하는데 도움이 될 수 있을 것이다.