• 제목/요약/키워드: lower secondary

검색결과 1,303건 처리시간 0.032초

An Assessment of the Secondary Neutron Dose in the Passive Scattering Proton Beam Facility of the National Cancer Center

  • Han, Sang-Eun;Cho, Gyuseong;Lee, Se Byeong
    • Nuclear Engineering and Technology
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    • 제49권4호
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    • pp.801-809
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    • 2017
  • The purpose of this study is to assess the additional neutron effective dose during passive scattering proton therapy. Monte Carlo code (Monte Carlo N-Particle 6) simulation was conducted based on a precise modeling of the National Cancer Center's proton therapy facility. A three-dimensional neutron effective dose profile of the interior of the treatment room was acquired via a computer simulation of the 217.8-MeV proton beam. Measurements were taken with a $^3He$ neutron detector to support the simulation results, which were lower than the simulation results by 16% on average. The secondary photon dose was about 0.8% of the neutron dose. The dominant neutron source was deduced based on flux calculation. The secondary neutron effective dose per proton absorbed dose ranged from $4.942{\pm}0.031mSv/Gy$ at the end of the field to $0.324{\pm}0.006mSv/Gy$ at 150 cm in axial distance.

Secondary Production of Monocorophium acherusicum (Amphipoda, Corophiidae) in a Seagrass Bed (Zostera marina)

  • Jeong Seung-Jin;Yu Ok-Hwan;Suh Hae-Lip
    • 한국수산과학회지
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    • 제39권spc1호
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    • pp.236-241
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    • 2006
  • We measured the secondary production of the amphipod Monocorophium acherusicum Costa in a seagrass bed (Zostera marina L.) in Gwangyang Bay, southern Korea. M. acherusicum biomass was positively correlated (P<0.05) with seagrass standing crop, suggesting that there were biological interactions between the two species. M. acherusicum displays two main breeding periods per year: spring (March to April) and fall (October to November). M. acherusicum biomass in the spring breeding periods was higher than in the fall. Annual secondary production of M. acherusicum was 3.54 g DW/$m^2$/yr with an annual P/B ratio of 3.48. Secondary production and the P/B ratio of M. acherusicum were lower than those observed for other amphipods inhabiting seagrass beds. These results suggest that biological interactions between M. acherusicum and seagrass, as well as dietary competition with other amphipods can potentially cause declines in secondary production and the P/B ratio.

Characteristic of Lower Hydrogenated Oxide Films Deposited by the Higher Energy Assisting Deposition Systems Using the with Precursor Siloxane Species

  • Kim, J.;Yang, J.;Park, G.;Hur, G.;Lee, J.;Ban, W.;Jung, D.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.339.1-339.1
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    • 2014
  • In this paper we studied the application of inter-poly dielectric as silicon dioxide-like film was deposited by the higher energy assisting deposition (HEAD) process the modified CCP process, which enables low temperature (LT) process and improving film density. In these experiments the relative hydrogen concentration of $SiO_2$-like films deposited on silicon substrate were analyzed by the secondary ion mass spectroscopy (SIMS) and it was shown that our lower hydrogenated oxide (LHO) film prepared by HEAD process with the precursor contained the siloxane species had lower hydrogen concentration, $8{\times}10{\cdot}^{22}cm{\cdot}^3$ than that of the commercial undoped silicon glass (USG) film ($1{\times}10{\cdot}^{21}cm{\cdot}^3$) prepared by the high density plasma-chemical vapor deposition (HDP-CVD). We consider that the LHO film deposited by HEAD process used as high performance material into Flash memory devices.

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이차전지용 알루미늄 파우치 필름의 제조 공정 변수에 따른 접착력에 대한 연구 (Study on the Adhesive Strength by the Manufacturing Process Parameter of the Aluminum Pouch for Secondary Battery)

  • 유민숙;김도현;조정민;배성우;김동수
    • 한국정밀공학회지
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    • 제33권2호
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    • pp.149-155
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    • 2016
  • In this study, we investigated the adhesive strength by molecular weight, mixture ratio, coating thickness, lamination temperature and aging condition of adhesive in manufacture process of Nylon-Aluminum for secondary aluminum pouch. It found that as the molecular weight of adhesive gets lower, the adhesive strength increases. In the mixture ratio, as the content of hardener get higher and as the content of solvent get lower, the adhesive strength increases. Also, as the coating thickness of adhesive get thicker, the adhesive strength increase. In addition, the adhesive strength is higher at 90 degrees of lamination temperature. So, it found that 90 degrees of lamination temperature is appropriate. In the aging condition when aged for 5 days, it found that the reaction and curing of adhesive is sufficient by measuring the adhesive strength.

비골골절의 비관혈적 정복술 중 사용한 초음파의 유용성 (Usefulness of Ultrasound-Guided Closed Reduction of Nasal Bone Fracture)

  • 이성표;석정훈;최원석;김태범;양완석
    • 대한두개안면성형외과학회지
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    • 제9권1호
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    • pp.12-16
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    • 2008
  • Purpose: Closed reduction is most common treatment method for nasal bone fracture but it requires secondary correction operation commonly. For preventing secondary revision, we applied ultrasonography during closed reduction of nasal bone fracture and examined the result of operation. Methods: 80 patients were sorted into 2 groups, ultrasound-guided closed reduction group(n=40) and manual closed reduction group(n=40). We classified the unilateral fracture involving lower 1/2 of nasal bone into type I, the bilateral fracture involving lower 1/2 of nasal bone into type III and the fracture of upper 1/2 of nasal bone into type III. The occurrence rate of overcorrection and undercorrection were evaluated by comparing preoperative and postoperative MDCT(Multi Direction Computed Tomography). Results: In manual closed reduction group, overcorrection were found in 4 patients and undercorrection were found in 3 patients. In ultrasound-guided closed reduction group, overcorrection was not observed and undercorrection was observed in 2 patients. Conclusion: Intraoperative ultrasound evaluation of nasal bone fracture resulted in reduced occurrence rate of secondary nasal deformities, showed easier detection of the fractured site and have superiority upon simple physical examination or simple x-ray.

넓은 유리 광 배 근피부 판을 이용한 하지 재건술 (Reconstruction of the Lower Extremities with the Large Latissimus Dorsi Myocutaneous Free Flap)

  • 이준모;허달영
    • Archives of Reconstructive Microsurgery
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    • 제9권1호
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    • pp.80-87
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    • 2000
  • Acute high speed accidents that results in full thickness skin defect and exposure of tendon, nerve, vessel and periosteum over denuded bone demands soft tissue coverage. Exposed bone often ensues chronic infection and requires free flap transplantation which surely covers defects in one stage operation and enhances transport of oxygen-rich blood and converts a non-osteogenic or partially osteogenic site into a highly osteogenic site, but exposed bone which had performed free flap transplantation sometimes necroses and needs secondary bone procedure. Scar contracture limits joint motion should be excised and covered with normal soft tissue to restore normal range of motion. Authors have performed the large latissimus dorsi myocutaneous free flap in 8 cases of extensive soft tissue defect and exposed bone lesion in the leg and 1 case of the flap was failed. The secondary ilizarov bone procedure was performed in 3 of 8 cases. 2 cases of large burn scar contracture and 1 case of posttraumatic scar contracture in lower extremity were restored with the large latissimus dorsi myocutaneous free flap. Authors concluded that large latissimus dorsi myocutaneous free flap is the most acceptable microvascular procedure in large soft tissue defect combined with exposed periosteum and bone requiring secondary bone procedure and in large burn scar contracture limiting knee joint motion.

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종양으로 인한 이차성 림프부종에 대한 오령산 치험 2례 (Two Cases of Cancer-induced Lymphedema Patients Treated with Oryeongsan)

  • 이지영;채진;정의홍;이수경;정현식
    • 대한한방내과학회지
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    • 제34권3호
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    • pp.322-328
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    • 2013
  • Objectives : The purpose of this study was to report two cases which suggest Oryeongsan as a pharmacological treatement option for cancer-induced secondary lymphedema. Methods : The cases were two female patients with peripheral edema. The first was diagnosed with cervical cancer with paraaortic lymph node metastasis and suffered from bilateral edema of the lower extremities. The second was a breast cancer patient with right arm lymphedema, which was aggravated after a weekly regimen of chemotherapy. Oryeongsan was orally administered for 3-4 days to both patients. Results : The symptoms in lower extremities and body weight of the cervical cancer patient decreased. The breast cancer patient did not lose body weight, but pain in upper extremities was reduced. Conclusions : Oryeongsan may potentially be an option for secondary lymphedemas, including cancer-induced lymphedema.

프랑스의 수학교육 및 수학교육과정 (The Teaching of Mathematics and the Mathematics Curriculum in France)

  • 장혜원
    • 대한수학교육학회지:학교수학
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    • 제3권2호
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    • pp.401-421
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    • 2001
  • This paper describes the teaching of mathematics in France at the elementary and secondary levels. It consists of four parts: the structure of the french education system and the status of mathematics within it, the evolution of mathematics teaching in France from 1968 to nowadays, the teacher training in France, the mathematical contents in the elementary school curriculum and the mathematics curriculum in the lower secondary school. From this review, we can extract some characteristics of the teaching of mathematics in France.

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간섭 제약 네트워크에서 파운틴 코드를 사용한 협동 릴레이 프로토콜 설계 (Cooperative Relaying Protocol using Fountain Codes under Interference Constraint Networks)

  • 공형윤
    • 한국인터넷방송통신학회논문지
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    • 제13권3호
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    • pp.39-45
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    • 2013
  • 본 논문에서는, 간섭 조건의 2차 네트워크에서 파운틴 코드를 사용하는 협력 릴레이 프로토콜을 제안한다. 제안된 프로토콜에서 2차 소스는 2차 릴레이의 도움으로 2차 목적지까지 파운틴 코드로 메시지를 전송한다. 2차 소스와 릴레이는 언더레이 모델에서 작동하며, 1차 사용자에 의해 발생된 간섭의 경우, 허용된 임계 값보다 낮기 때문에 2차 소스와 릴레이의 전송 전력에 적응해야한다. 제안된 프로토콜의 성능 평가를 위해, 레일리히 페이딩 채널환경에서 평균 전송 시간의 식을 유도한다. 또한, 몬테-카를로 시뮬레이션을 통하여 유도된 식을 검증 하였다.

컴퓨터 시뮬레이션을 이용한 최적 이차침전지 형상 파악 (Defining optimum configuration for secondary clarifier using computer simulation)

  • 이병희
    • 상하수도학회지
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    • 제24권2호
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    • pp.219-230
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    • 2010
  • Computer simulation has been widely used to design and optimize the operation of wastewater treatment plants since 1980. For secondary clarifiers, the simulation has been a tool to optimize the performance by providing dimensions for flocculation well. However, there has been no attempt to find the optimized geometrical parameters in circular secondary clarifier using simulation tools. In this study, three SVIs (Sludge Volume Indexes), two well types (feed and flocculation wells), 8 SWDs (Side Water Depths) and 9 bottom slopes were variables for simulation. Diurnal inflow and associated MLSS (Mixed Liquor Suspended Solid) concentrations were used for input loadings. When flocculation well was installed, 48% less concentration at lowest ESS (Effluent Suspended Solid) concentrations was produced and the diurnal ESS concentration range had been reduced by 52%. From these results, flocculation well must be installed to produce lower and stable ESS from circular secondary clarifiers. Under same loading conditions with $300m{\ell}$/g of SVI, The lowest ESS was produced when SWD was 4.5m with 4% of bottom slope. Therefore, SWD and bottom slope must not be deeper than 4.5m and must be near 4%, respectively, in circular clarifier with flocculation well to produce the lowest ESS concentration.