The present study was conducted to judge the applicability of field quality control by children's goods manufacturers by assessing the contents of heavy metals such as Pb and Cd in outdoor play goods for children through measurement using Portable XRF and comparing the results through detailed analyses using ICP. Heavy metal contents of 711 part samples of 505 products were measured using XRF. According to the results, the ratio of products that exceeded the Pb and Cd content standards specified under the Quality Management and Safety Control of Industrial Products Act were 2.4% and 2.6%. Many products certified for self-regulated safety exceeded the standards and thus it was considered that harmful chemical material centered safety management systems would be necessary. Detailed ICP analyses of some products were compared and the results showed deviations of 0.9～80.8% from XRF results. The reasons for this are deviations in the characteristics of measured cross sections and the homogeneity of samples resulting from sample preparation methods, etc. Therefore, it is considered that field quality control will be applicable if measuring methods are efficiently established based on product characteristics and calibration curve preparation methods are established through quality control.

본 연구는 각 호흡 위상에 따른 계획용표적체적(planning target volume. PTV)의 움직임 및 체적(PTV volume)의 변화를 횡격막(diaphragm)의 움직임을 이용하여 정량적으로 분석함으로써 폐암의 호흡 동기 방사선치료를 위한 최적화된 호흡 위상을 알아보고자 하였다. 비특이적 호흡이나 불규칙적인 호흡에 의한 체계적 오류(system error)를 최소화하기 위하여 모의 호흡 훈련을 시행하였다. 정규화된 호흡 동기 방사선치료 절차에 따라 각 호흡 위상 i에 따른 4차원 전산화치료계획(4-dimensional computed tomography. 4DCTi)을 시행하였으며 0~90%, 30~70%, 40~60% 호흡위상으로 재구성된 4DCTi 영상에서 PTV를 정의하고 PTVi의 움직임 및 체적의 변화를 정략적으로 분석하였다. 모의호흡 훈련에 의한 평균 호흡 주기는 3.4±0.5초로 나타났으며 임상적으로 유도되는 예상 값과 실제 측정값의 일치 정도를 나타내는 R-제곱 값은 1에 근접하여 유의하였다. 또한 각 호흡 위상 i에 따른 PTVi의 움직임은 0~90% 호흡 위상의 경우 13.4±6.4mm, 30~70% 호흡 위상의 경우 6.1±2.9mm, 40~60% 호흡 위상의 경우 4.0±2.1mm 이었으며 PTVi의 체적 변화는 30~70% 호흡 위상의 경우 32.6±8.7%, 40~60% 호흡 위상의 경우 41.6±6.2% 감소되었다. 결론적으로 짧은 호흡 위상(40~60%: 30% duty cycle) 폭을 적용하였을 때 PTV의 움직임 및 체적의 변화가 감소되어호흡을 고려한 PTV 마진이 4mm 이내이면서 PTV 내 선량의 균일성을 얻을 수 있었다.

This study was conducted to investigate the effect of mature stages on quality of Rafito tomatoes (Lycopersicon esculentum Mill.) during storage at low temperature. Tomatoes grown in greenhouse were harvested at three different mature stages (turning, pink, and red), packaged with a 30-μm-thick polyethylene film, and then stored at 5 and 10℃, respectively. The changes in firmness, soluble solids content (SSC), titratable acidity (TA), colour, lycopene content, decay, and chilling injury were measured on a weekly basis. After three weeks of storage, chilling injury and decay were found to have individually occurred at 5 and 10℃, respectively. As there was little change in quality at 5℃, it was concluded that red tomatoes could maintain their good quality for two weeks. The normal postharvest ripening was inhibited in the turning and pink tomatoes during storage at 5℃. The turning and pink tomatoes showed improved quality after two-week storage at 10℃. In particular, the turning fruits showed the highest firmness throughout the storage period. Furthermore, the red colour, SSC/TA, and lycopene content of the turning fruits reached the same levels as with the red fruits after two-week storage at 10℃. These results suggest that red tomatoes should be stored at 5℃ to inhibit decay, and that the optimum temperature for early-harvested tomato (turning and pink) is 10℃ for the ripening process after harvest.

의료용 선형가속기 (linear accelerator)와 나선형 컴퓨터 단층 촬영 장치 (helical computed tomography scanner)의 결합 장치인 토모테라피는 세기 변조 방사선 치료 (intensity modulated radiation therapy(IMRT))의 큰 혁신을 이끌었다. 토모테라피 치료 과정에서, Megavoltage computed tomography (MVCT) 영상획득은 치료 환자의 정확한 자세 정렬을 위해 치료 전 또는 후에 이용된다. 그러나 이는 환자의 총 선량을 증가시키는 결과를 만들며, 본 연구는 이처럼 MVCT 영상 획득 시 증가되는 선량을 Cylindrical "Cheese" Phantom을 이용하여 측정, 비교하였다. 각각의 pitch별로 (1, 2, 3 mm) 동일한 개수의 slice (10 slice), 그리고 동일한 length (약 9 cm)를 scanning하여, 이때의 선량 (MVCT Scanning Dose)을 A1SL ion chamber를 이용하여 측정하였다. 측정 결과 동일한 Slice 개수 (각각의 pitch 당 10개)일 때, MVCT scanning dose의 평균값은 각각 (pitch 1, 2, 3mm) 2.24 cGy, 1.02 cGy, 0.81 cGy가 측정되었다. 동일한 length에서 MVCT scanning dose의 평균값은 각각 (pitch 1, 2, 3mm) 2.47 cGy, 1.28 cGy, 0.88 cGy가측정되었다. 이는 할당된 pitch와 scanning length가 MVCT scanning dose에 큰 영향을 미치는 가장 중요한 매개 변수임을 말하며, pitch는 MVCT scanning dose와 역비례 관계를 나타냈다. 때문에 적절한 pitch와 scanning length의 선택으로 치료 선량 외의 추가 선량을 최소로 줄여야 하겠다.

For the investigation of the quality loss of mulberry during distribution, the deterioration rate, microorganism growth, and sensory quality of mulberry kept at 20, 10 and 0℃, respectively, were investigated. Based on the results, the optimum temperature for extending the freshness of mulberry was examined in the temperature range of -1.5 to 1.5℃. The level of mold in the mulberry kept at 20 and 10℃, respectively, was much higher than that kept at 0℃. The quality of the mulberry deteriorated seriously after two days at 20℃, after six days at 10℃, and after 12 days at 0℃. The marketability of mulberry as determined via sensory evaluation was much more prolonged by decreasing the keeping temperature from 20 to 0℃. To extend the freshness of mulberry using these results, the optimum temperature was evaluated at the range of -1.5 to 1.5℃ for 25 days. During storage, the changes in the color and pH of the berry were not significantly different by storage temperature, but the microbial levels and deterioration rate increased in the order of 1.5, 0, and -1.5℃. In particular, the firmness of the mulberry decreased rapidly at 1.5℃, showing a significant difference from the others. The titratable acidity and sugar contents decreased gradually at all the applied temperatures. The anthocyanin content decreased sharply at 1.5℃ but gently changed at -1.5℃. Through the sensory results of this study, it was adjudged that the marketability of mulberry could be maintained about 0.7 times at 1.5℃ and 1.3 times at -1.5℃ compared with the marketability at 0℃, respectively.

게임업계 맞춤형 인력양성사업은 2009년부터 정부가 선정 및 지원하는 계약학과를 통하여 본격적으로 진행된 바, 본 논문에서는 가천대학교의 게임프로젝트트랙을 통하여 지난 3년간 진행되었던 게임인력 양성사례 및 그 성과를 분석한 것이다. 게임프로젝트트랙은 38개의 중견 게임업체와 산학협력계약을 체결한 후 교육과정개발 및 학생선발 등을 공동으로 추진하면서 체계적인 산학협력 시스템을 구축하였으며, 특히 게임업체에서 요구하는 현장밀착형 교육을 진행하기 위하여 협력업체 대표 혹은 개발팀장이 정규교육과정에 투입되면서 실무교육의 질을 한 차원 높였다. 또한 학기 중 부족한 게임개발 시간을 확보하기 위하여 방학 중 현업개발자의 게임개발 특강 및 협력업체에서의 인턴실습 등을 통하여 학생들의 현장적응 능력을 크게 강화한 결과, 졸업생 40명 중 39명(97.5%)이 채용되고 6개(8팀)의 외부공모전을 수상하는 등의 괄목할 만한 성과를 창출함으로써 게임업계의 인재양성에 필요한 산학협력교육의 새로운 패러다임을 제시하였다.

In this paper, we evaluate the applicability of p-y curve on the lateral behavior of monopile foundations as compared with FEM 3D models and present safety factors in case p-y curve method is used to investigate the lateral behavior of monopile foundations for 5MW offshore wind turbines in Korea.

In this study, bearing capacities under large lateral displacement were obtained using the formulas suggested by Naeim & Kelly(1999) and ISO 22762 Part.3(2010) and those were compared with the results of Hwang's experiments(2006) to decide which formula is more reasonable

The application of a base isolation to nuclear systems should be considered in lots of view points of operation at the stage of design before construction. Those points includes protection and maintenance of isolators for a seismically isolated nuclear power plant. The methodology suggested in this paper is applicable for any type of isolators in which an isolated structure part is easily replaced and confined pressure can be easily controlled with a height-adjustable part. The height-adjustable part being adjusted by suppling or discharging fluid therein or therefrom

This paper introduces the performance of a newly developed base isolation system made from the combination of a polyurethane disk - attached double friction PTFE plate and MER Springs. Type test have been completed to confirm shear dependency characteristics and comparison with design value to AASHTO Guide spec. As a results, It is that all requirements for bridge bearing in the AASHTO guide spec. are satisfied.

In this paper, we analyze the lateral behavior of a jacket substructure for offshore wind turbine embedded in sandy soil, and identify the differences of results by soil modeling methods that are fixed end method, coefficient of subgrade reaction method, coupled matrix method, and p-y, t-z, q-z curve methods.

I investigated the river morphology and river naturality according to the environment of the Hwang River. The numbers of flexions at the upstream regions were more than those of downstream regions. The Hwang River showed very low overall diversity of the flow. Materials of river shore at low channel width were mainly boulders or gravel at the upstream regions, and the middle and downstream were silts and clay. Artificial masonry and natural materials were mixed from materials of river levees. The Hwang River was some of the natural herbaceous vegetation to riparian zones. Land utilities for floodplain were extremely overall farmland were predominant, and partly used by natural vegetation in the forest, a soccer field, some park facilities, residential, and commercial facilities. The water was width sleep / rivers beam ratio of 10 to 20%. Currently estimation for river naturality widely used in rivers were consisted of a narrow wide a variety of items and did not reflect the actual.

수자원시스템의 설계공급량을 결정하기 위한 평가지표의 선택은 수자원기술자가 직면한 중요한 문제이다. 대부분 신뢰도, 회복도 그리고 취약도를 대상으로 평가하게 된다. 그러나 각 지표 간에는 중복성이 있고 회복도와 취약도는 용수공급 여건이 나빠져도 개선되는 증감현상이 나타날 수 있다. 실제 적용에서는 이와 같은 문제점을 인지하지 못하고 한번 계산된 추정치로 판단하는 경우가 대부분이다. 이런 현상에 대한 원인은 수자원시스템의 다양한 특성에 의해 나타나고 있는데 수문 및 수요의 계절적 변동성이 대표적이다. 본 연구에서는 우리나라 댐 설계시 일반적으로 적용하고 있는 신뢰도 지표에 추가하여 다기준 적용을 위한 회복도 및 취약도의 적용성을 분석하였다. 분석방법은 계절적 변동성이 큰 농업용수의 구성비율을 기준으로 7개댐을 선정하여 각 지표 간 상관성과 증감현상을 분석하였다. 분석 결과, 연중 일정량을 공급하는 용담댐은 일반적 추세를 보였으나 농업용수를 공급하는 충주, 안동 및 남강댐 등은 회복도와 취약도에서 증감현상이 뚜렷이 나타났다.