• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.447-452
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• 1998

우리나라에서도 고준위폐기물 처분시설의 장기안전성 확보를 위한 기초연구가 시작되고 있어 안전성 기준에 대한 논의가 필요한 시점이다. 여기서는 고준위폐기물 처분시설의 안전성 기준에 대한 국제기관들의 권고하는 기준들을 조사하고, 현재 여러 나라에서 제안되거나 개정중에 있는 기준들을 비교 분석하였다. 안전성기준에서의 큰 차이점은 유도기준의 필요성(현재 미국만의 유도기준을 사용), ALARA 적용문제, 종합적 위험도 적용방법론의 문제, 위험도 수준등에서 나타나고 있으며, 특히 미래 상황의 불확실성 때문에 현재 및 개 국가에서 제시하고 있는 안전성평가기간 (10,000면)은 계속 논란이 일 것으로 보인다. 미래 예측이 어느 정도 가능한 최소한의 기간(수천년 혹은 만년)까지는 위험도를 기준으로, 그리고 그 이후는 지표로의 누출율을 기준으로 정하는 것도 바람직한 대안이 될 것으로 생각된다. 또한 안전성기준은 설계자로 하여금 대안분석을 통한 최적화를 방해하는 구체적인 유포기준보다는 융통성을 어느 정도 부여하는 방향으로 설정되는 것이 바람직한 것으로 사료된다.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.2 s.95
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• pp.5-14
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• 1999

The necessity of six axis force-torque sensors is well recognized in the fields of automatic fine assembly, deburring polishing, and automatic fish processing using robotic manipulators. The paper proposes a simple and compact elastic structure of the force-torque sensor which senses externally applied three force and three torque components. Rough surface strain distribution of the elastic structure is examined analytically, and then more accurate surface strain are obtained from finite element analysis. The compliance matrix which is a linear relationship between force components and strain measurements is obtained for the proposed sensor. Some basic principles of measuring 3 force and torque components are also presented.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.2
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• pp.345-353
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• 1994

This paper proposes a high resolution direction finding method, which is so called the 'averaged MUSIC'. This method uses a new sample array covariance matrix that consists of diagonal components obtained by taking averages of the diagonal component values of the sample covariance matrix for the MUSIC. This paper also shows that the proposed method performs higher resolced direction-of-arrival estimation than the MUSIC in such cases as low signal-to-noise ratio, closed signal sources, and limited number of sensors, based on the statistical analysis.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.262-265
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• 2003

Radiofrequency thermal ablation (RTA) as one of the microwave hyperthermia is becoming the treatment of choice for small but inoperable tumors of the liver. In this paper, we designed the applicator composed of semi-rigid coaxial cable antenna with a ring slot for RTA. To optimize the maximum output of radiation at 2450 MHz, we simulated the antenna using Electromagnetic simulation tools Maxwell program and analyzed the return loss and the electric field $E_{tot}$ at the near-field region between the simulation results and measurement results. As a result, we obtained the return loss of -29.786 dB at 2450 MHz when the antenna was placed between two blocks of a pig's liver, and the measurement results agreed with the simulation results well. Therefore, this semi-rigid coaxial cable antenna with a ring slot can be used very usefully as the applicator for RTA.r RTA.A.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.2
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• pp.98-104
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• 2005

A glass transfer robot is used for handling LCDs in the production line of flat panel displays under clean environments. During glass transfer operations of the robot, chattering phenomenon occurs at the robot hand. This deteriorates the accuracy and repeatability of the end-effector of the robot. In this paper, we present the kinematic solution of the robot and then analyze the cause of this chattering phenomenon in view of the mechanism and servo control and propose a practical solution that can reduce the chattering significantly at the robot hand of the glass transfer robot.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.6
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• pp.627-637
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• 2011

To cope with the high power density and low cost in switching power supply, this paper presents a novel planar transformer, which can regulate the leakage inductance of planar transformer used for LLC resonant converter. Modeling and analysis of a novel planar transformer are discussed in detail and a prototype 200W LLC resonant converter is tested to verify.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.3
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• pp.177-181
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• 2005

Yellowish uranium compounds were enriched at the interface between a Ca-bentonite block and a waste glass, containing about $20\%$ uranium oxide, in contact with the block due to the dissolution of uranium by a synthetic granitic groundwater in Ar atmosphere. The uranium compound formed for 6 years leach time was identified as a beta-uranophane $[Ca(UO_2)_2(SiO_{3}OH)_{2}5H_{2}O]$ using XRD, IR and mass spectrometer. The solubility of the beta-uranophane was measured to be about $10^{-6}\;mole/L$ in de-mineralized water at $80^{\circ}C$.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.1229-1232
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• 2005

국내 공공기관에서는 사이버 행정환경의 기밀성, 무결성, 신원확인, 부인방지등을 보장하기 위하여 행정전자서명인증체계(GPKI:Government Public Key Infrastructure)의 구축과 함께 모든 문서를 XML형태로 표준화하여 공공기관간의 문서를 통합하기 위한 시도를 하고 있다. 하지만 행정전자서명인증체계에서 사용하는 공개키기반(PKI)을 연동한 인증체계는 단순한 사용자 인증만을 제공하여, 공공기관의 응용업무 환경에서 요구되는 다양한 사용자의 직위, 직무, 역할정보 등의 관리가 어려우며 XML형태의 공공문서에 대한 상세한 접근제어를 지원하지 못하는 한계점이 있다. 이러한 한계점을 해결하기 위하여 본 논문에서는 공공기관에서 사용하는 인증 및 접근제어 시스템의 가상시나리오를 통하여 보안문제점을 도출하고 분석한 후에 이를 근거로 공공기관의 보안 문제점을 해결할 수 있는 보안기술인 PMI(Privilege Management Infrastructure)와 XACML(eXtensible Access Control Markup Language)을 연동한 접근제어모델을 제안하였다..

• Tunnel and Underground Space
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• v.13 no.2
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• pp.138-152
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• 2003

Three-dimensional computer modeling using FLAC3D had been carried out fur evaluating the thermal-mechanical stability of a high-level radioactive waste repository excavated in several hundred deep location. For effective modeling, a FISH program was made and the geological conditions and rock properties achieved from the drilling sites in Kosung and Yusung areas were used. Sensitivity analysis fer the stresses and temperatures from the modeling designed utilizing fractional factorial design was carried out. From the sensitivity analysis, the important design parameters and their interactions could be determined. From this study, it was found that deposition hole spacing is the most important parameter on the thermal and mechanical stability. The second and third most important parameters were disposal tunnel and buffer thickness.

• Journal of Yeungnam Medical Science
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• v.7 no.1
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• pp.197-201
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• 1990

The primary treatment modality of malignant tumors of the nasopharynx is radiation therapy owing to its inaccessibility to surgical intervention. Over the last two decades there were many changes in techniques of delivery, which include the use of higher doses of radiotherapy, the use of wide radiation field, including the elective radiation of the whole neck, the combined use of brachy- and teletherapy, and the use of split-course therapy. In spite of these advances local and regional recurrences remain the major cause of death. As a boost therapy after external irradiation, high-dose-rate intracavitary irradiation using remote control afterloading system(RALS) was used in two patients. Our results were satisfactory, however, this procedure should only be performed by those who have developed enough expertise in the use of intracavitary techniques for the treatment of nasopharyngeal cancer and have a supportive team including a physicist, dosimetrist, nurse, and trained technologist.