• The Journal of Korean Society for Radiation Therapy
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• v.18 no.1
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• pp.1-5
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• 2006

Purpose: IMRT quality assurance(Q.A) is consist of the absolute dosimetry using ionization chamber and relative dosimetry using the film. We have in general used 0.015 cc ionization chamber, because small size and measure the point dose. But this ionization chamber is too small to give an accurate measurement value. In this study, we have examined the degree of calculated to measured dose difference in intensity modulated radiotherapy(IMRT) based on the observed/expected ratio using various kinds of ion chambers, which were used for absolute dosimetry. Materials and Methods: we peformed the 6 cases of IMRT sliding-window method for head and neck cases. Radiation was delivered by using a Clinac 21EX unit(Varian, USA) generating a 6 MV x-ray beam, which is equipped with an integrated multileaf collimator. The dose rate for IMRT treatment is set to 300 MU/min. The ion chamber was located 5cm below the surface of phantom giving 100cm as a source-axis distance(SAD). The various types of ion chambers were used including 0.015cc(pin point type 31014, PTW. Germany), 0.125 cc(micro type 31002, PTW, Germany) and 0.6 cc(famer type 30002, PTW, Germany). The measurement point was carefully chosen to be located at low-gradient area. Results: The experimental results show that the average differences between plan value and measured value are ${\pm}0.91%$ for 0.015 cc pin point chamber, ${\pm}0.52%$ for 0.125 cc micro type chamber and ${\pm}0.76%$ for farmer type 0.6cc chamber. The 0.125 cc micro type chamber is appropriate size for dose measure in IMRT. Conclusion: IMRT Q.A is the important procedure. Based on the various types of ion chamber measurements, we have demonstrated that the dose discrepancy between calculated dose distribution and measured dose distribution for IMRT plans is dependent on the size of ion chambers. The reason is small size ionization chamber have the high signal-to-noise ratio and big size ionization chamber is not located accurate measurement point. Therefore our results suggest the 0.125 cc farmer type chamber is appropriate size for dose measure in IMRT.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.2
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• pp.237-244
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• 2007

An experiment was conducted to study the growth performance, bone mineralization and mineral excretion in broiler starter chicks fed high levels of cholecalciferol (CC) at sub-optimal levels of calcium (Ca) and non-phytate phosphorus (NPP). Five hundred and sixty day-old Vencobb female broiler chicks were housed in raised wire floor stainless steel battery brooder pens ($24"{\times}30"{\times}18"$) at the rate of five chicks per pen. A maize-soyabean meal basal diet was supplemented with dicalcium phosphate, oyster shell powder and synthetic CC to arrive at two levels each of Ca (0.50 and 0.60%), and NPP (0.25 and 0.30%) and four levels of CC (200, 1,200, 2,400 and 3,600 ICU/kg) in a $2{\times}3{\times}4$ factorial design. Each diet was fed ad libitum to chicks in 7 pens from 2 to 21days of age. Body weight gain, feed intake and bone weight increased (p<0.05) with increase in level of CC at both the Ca and NPP levels tested. The CC levels required to obtain significant improvement in body weight gain and feed intake reduced (2,400 ICU/kg vs. 1,200 ICU/kg) with increase in levels of P in diet (0.25% vs. 0.3%, respectively). The feed conversion ratio was significantly improved (p<0.05) with increase in level of CC from 200 to 1,200 ICU/kg diet at 0.5% Ca, while at 0.6% Ca, the level of CC in diet did not influence the feed efficiency. Tibia mineralization (density, breaking strength and ash content) and Ca and P contents in serum increased significantly (p<0.05) with increase in levels of CC in diet. The CC effect on these parameters was more pronounced at lower levels of Ca and NPP (0.5 and 0.25%, respectively). The data on body weight gain and feed intake indicated that NPP level in diet can be reduced from 0.30 to 0.25% by increasing CC from 200 to 2,400 ICU/kg. Similarly, the bone mineralization (tibia weight, density and ash content) increased non-linearly (p<0.01) with increase in CC levels in diet. Concentrations of P and Mn in excreta decreased (p<0.01), by increasing CC level from 200 to 2,400 ICU/kg diet. It can be concluded that dietary levels of Ca and NPP could be reduced to 0.50 and 0.25%, respectively by enhancing the levels of cholecalciferol from 200 to 2,400 ICU/kg with out affecting body weight gain, feed efficiency and bone mineralization. Additionally, phosphorus and manganese excretion decreased with increase in levels of CC in broiler diet.

• Journal of Information Processing Systems
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• v.11 no.2
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• pp.266-279
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• 2015

In this paper, we propose a novel block cipher mode of operation, which is known as the counter chain (CC) mode. The proposed CC mode integrates the cipher block chaining (CBC) block cipher mode of operation with the counter (CTR) mode in a consistent fashion. In the CC mode, the confidentiality and authenticity of data are assured by the CBC mode, while speed is achieved through the CTR mode. The proposed mode of operation overcomes the parallelization deficiency of the CBC mode and the chaining dependency of the counter mode. Experimental results indicate that the proposed CC mode achieves the encryption speed of the CTR mode, which is exceptionally faster than the encryption speed of the CBC mode. Moreover, our proposed CC mode provides better security over the CBC mode. In summary, the proposed CC block cipher mode of operation takes the advantages of both the Counter mode and the CBC mode, while avoiding their shortcomings.

• Progress in Superconductivity and Cryogenics
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• v.19 no.4
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• pp.26-30
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• 2017

The promising characteristics of 2G high-temperature superconductor (HTS) coated conductor (CC) tapes have made it possible to apply to various electrical device applications. In this study, the mechanical and electromechanical properties of Sn-Cu double layer stabilized GdBCO CC tapes have been characterized. The stress and strain tolerances of $I_c$ in GdBCO CC tapes adopting stainless steel substrate were evaluated using $I_c$-strain measurement at 77 K under both uniaxial tension and monotonic bending conditions. The results were compared to the conventional single Cu layer stabilized CC tape. As a result, the Sn-Cu double layer stabilized GdBCO CC tapes showed somehow lower or comparable electromechanical properties as compared to the Cu stabilized CC tape ones.

• Nuclear Engineering and Technology
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• v.7 no.3
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• pp.223-226
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• 1975

The relative detection efficiency of ${\gamma}$-ray full-energy Peaks was obtained by a pair-point method using the $^{56}$ Co source whose ${\gamma}$-ray relative emission rates were well measured. Three Ge(Li) detectors with active volumes of 43.8cc, 32.6cc, and 6cc were calibrated over the ${\gamma}$-ray energy energy range 800-5, 500keV.

• Journal of Environmental Health Sciences
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• v.14 no.2
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• pp.13-27
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• 1988

Two asbestos slate manufacturing and seven asbestos textile plants in Korea were surveyed from May 20 to July 2, 1987. The purposes of this study were to evaluate 1) worker exposure to asbestos, 2) compliance to the standards and 3) the efficiency of existing local exhaust systems. Sixty-two personal samples and eighty-three area samples were collected and analyzed using "NIOSH 7400" method. Results of this study were as follows. 1. The asbesots exposure concentrations in asbestos textile plants were 1.3 - 14.3 fibers/cc(geometric mean(GM), 4.4 fibers/cc). 2. Worker exposure level to asbestos fiber in asbestos slate manufacturing industry was 0.21 fibers/cc during wet processing, which is below the Korean Standard of 2 fibers/cc. 3. Most local exhaust systems installed in asbestos textile plants were inadequately designed. 4. Ninety-six percent of the 145 samples exceeded the U.S. Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL) of 0.2 fibers/cc and forty-nine percent of the samples exceeded the Korean Standatd of 2 fibers/cc.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05c
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• pp.2121-2124
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• 2003

정보보호시스템의 국제공통평가기준인 CC(또는 ISO/IEC 1540B)에서는 평가용 문서(즉, 제출물)에 대한 세부지침을 포함하지 않고 있으므로, CC기반 평가체계를 구축하기 위해서는 문서 스키마(즉, 목차와 내용요구사항)를 개발해야 한다. 본 논문에서는 CC기반 평가체계에서 활용할 수 있는 문서 스키마를 개발하였다. CC내의 보증클래스로부터 Weakest precondition함수, 문서량 축소규칙, 문서 종속성 분석방법을 적용하여 문서스키마와 DTD를 개발하였다. 본 연구의 접근방법은 소프트웨어 품질의 평가체계에서 사용할 문서스키마 또는 DTD를 개발하는데 응용될 수 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11c
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• pp.1811-1814
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• 2003

CC는 정보보호시스템의 국제표준이며 CC평가 및 인증체계에서는 평가기관을 운영하며 평가기관에서는 적정한 평가비 산정을 위한 근거가 필요하다. 본 연구에서는 CC기준과 기존의 PP 및 ST만을 바탕으로 하여 제품유형별 및 보증수준별 평가업무량의 상대적 배수를 평가실무자들의 경험, 보안기능의 사용율 개념, 기능점수방법 등을 이용하여 산정하였다. 본 결과는 CC평가환경에서 정보보호제품의 평가비 및 기간의 산정을 위한 기본자료로 활용될 수 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.832-834
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• 2015

최근 CCRA(Common Criteria Recognition Arrangement) 협정서 개정에 따라 공통평가기준인 CC(Common Criteria) 평가제도에 변화가 생기고 있다. 현재의 CC 평가제도가 가지는 한계를 보완하고자 PP(protection profile)를 대신하는 cPP(collaborative protection profile)가 개발되었는데, 기존의 폐쇄적으로 운영되던 PP 개발 프로세스와 달리 cPP 개발에는 CCRA 회원국의 여러 기관 및 기업이 적극적으로 개발에 참여할 수 있다. 따라서 현재 세계 각국에서 cPP 개발에 관한 논의가 활발히 진행되고 있으며 세분화된 연구도 요구되고 있다. 본 논문에서는 기존의 CC 평가제도가 가지는 한계를 살펴보고 이러한 한계를 극복하기 위한 cPP의 등장 및 개정되는 새로운 CC 평가제도의 운영을 분석한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.1090-1093
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• 2009

최근 혁신적으로 발전하고 있는 데이터 방송은 사용자를 만족시키기 위해 더 높은 품질의 영상과 음성은 물론 다양한 어플리케이션을 제공하고 있다. 이러한 어플리케이션은 DSM-CC 프로토콜에 의해 STB(Set-top Box)에 전송되는데 각각의 DTV 미들웨어에 따라 DSM-CC 프로토콜의 데이터 구조가 다르다. 그리고 방송 환경의 특성상 데이터를 놓치게 되면 한 Cycle을 기다려야 하는 문제가 발생한다. 또한 캐시 관리 전략에 따라 사용자가 원하는 어플리케이션의 응답 속도가 다르기 때문에 효율적인 캐시 관리 전략이 필요하다. 본 논문에서는 각 미들웨어에서 사용하는 DSM-CC 프로토콜의 차이점을 파악하여 변경이 필요한 부분은 모듈화해서 쉽게 확장 할 수 DSM-CC 처리 시스템을 제안했다. 또한, 어플리케이션을 실행시키기 위한 응답 시간을 줄이기 위해 사용자의 선호도와 사용 빈도수를 고려한 캐시 전략을 제안한다.