• 제목/요약/키워드: Combined distribution line

검색결과 78건 처리시간 0.031초

균일한 두께분포를 위한 신장/블로 공정을 이용한 초소성 성형 공정설계 해석 (Analysis of Superplastic Forming Process Design Using a Combined Stretch/Blow Process for Uniform Thickness Distribution)

  • Hong, S.S.;Lee, J.S.;Kin, Y.H.
    • 한국정밀공학회지
    • /
    • 제11권1호
    • /
    • pp.129-137
    • /
    • 1994
  • A rigid-viscoplastic finite element method has been used for modeling superplastic stretch/blow process design to improve thickness distribution. Punch velocity-time relationship of the stretch forming and pressure-time cycle of the blow forming for a given strain rate are calculated. A superplastic material is assumed to be isotropic and a plane-strain line element based on membrane approximation is employed for the formulation. The effects of the width, corner radius and height of the punch during stretch forming are examined for the final thickness distribution, and the process design to improve thickness distribution can be established.

  • PDF

혼합배전계통에서 뇌과전압 해석을 통한 중성선과 가공지선 혼용 운전시 적정 피뢰기 위치에 관한 연구 (A Study on the Optimal Position of Lightning Arrester on Joint Operation of Neutral Wire and Overhead Grounding Wire through Lightning Surge Analysis in Combined Distribution System)

  • 정석산;장화윤;안천용;이종범
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2011년도 제42회 하계학술대회
    • /
    • pp.535-536
    • /
    • 2011
  • This paper studies the validity about a joint operation of neutral wire and overhead grounding wire in combined distribution systems. The overhead grounding wire and neutral wire are currently installed separately and grounded by common. However there is no any ineffectiveness or electrical problem in case of the proposed system, such system can be operated at real distribution system. Therefore this paper describes the suitability of a joint operation through lightning surge analysis on combined distribution systems and analyzes the optimal position of lightning arrester on joint operation of neutral wire and overhead grounding wire. Lightning surge analysis is carried out by EMTP/ATPDraw to obtain the overvoltage of overhead line and underground cable in various conditions such as location and current types of lightning stroke. Over voltage gained by the analysis show that the insulation strength of the joint operation case is not stable compare with the current operation case.

  • PDF

Spur Gear의 표면온도상승에 관한 연구 Part I - Flash Temperature (A Study on the Surface Temperature Rise in Spur Gear Part I - Flash Temperature)

  • 김희진;문석만;김태완;구영필;조용주
    • 한국윤활학회:학술대회논문집
    • /
    • 한국윤활학회 2000년도 제31회 춘계학술대회
    • /
    • pp.251-257
    • /
    • 2000
  • A numerical simulation of the temperature rise for sliding surface in dry contact is based on Jaeger's formula combined with a calculated heat input. A gear tooth temperature analysis was performed. The pressure distribution has the Hertzian pressure distribution on the heat source. The heat partition factor is calculated along line of action. A Temperature distribution of tooth surface is calculated about before and after profile modification. A Temperature of addendum and deddendum in modified gear have reduced.

  • PDF

시험관내의 인체폐암 세포 A549의 방사선 및 5-Fluorouracil에 대한 효과 (The Effect of 5-FU and Radiation on A549 Cells In Vitro)

  • 이명자;전하정;이원영
    • Radiation Oncology Journal
    • /
    • 제7권1호
    • /
    • pp.1-13
    • /
    • 1989
  • Effects of ionizing radiation alone and combined with chemotherapy on tumor growth and it's clonal specificity monitored by changes in distribution of chromosome number were studies in A549 ceil line originated from human adenocarcinoma of the lung. Radiation (300 rad, 600 rad and 900 rad) were delivered with or without 5-FU. Forty eight hours later, 57.5% of growth inhibition of cell w8s seen in cells treated with 5-FU concentration of $0.4{\mu}g/ml$ for 24hr exposure. Cell survival curves after radiation with and without 5-FU were made. Chromosomal analysis of cells in metaphase in control, and in cells treated with 300 rad of radiation, or $0.4{\mu}g/ml$ of 5-FU treatment, and combined treatment of both were done to examine the changes in ploidy and number of chromosome. Radiation combined with S-FU enhanced growth inhibition of A549 cells. However, no evidence of synergegic effects in growth. inhibition was observed in the cells treated with the combination therapy. Pattern of chromosomal distribution of survived cells were shifted from hyperploidy to hypoploidy by single dose of radiation (300 rad). As radiation dose increased a large number of hypoploidy cells were observed. Following treatment of cells with 5-FU, chomosomal distribution of survived cells were also shifted to hypodiploidy which were seen in cells treated with radiation, The ceil treated with 5-FU and fellowed by radiation within 24 hrs had cell with increased number of hypodiploidy cells. Almost same type of chromosomal changes were reproduced in cells treated with combined treatment with radiation and 5-FU. Minor differences were that cells with fewer number of chromosome were more frequent in cells treated with combined therapy. Further increase in cells of hypoploidy (93%) having 1-10 chromosome were induced by additional radiation. Therefore, the enhanced therapeutic effect of 5-FU combined with radiation of A549 cells appeared to be additive rather than synergistic.

  • PDF

유전 알고리즘과 Tabu Search를 이용한 배전계통 사고복구 및 최적 재구성 (A service Restoration and Optimal Reconfiguration of Distribution Network Using Genetic Algorithm and Tabu Search)

  • 조철희;신동준;김진오
    • 대한전기학회논문지:전력기술부문A
    • /
    • 제50권2호
    • /
    • pp.76-82
    • /
    • 2001
  • This paper presents a approach for a service restoration and optimal reconfiguration of distribution network using Genetic algorithm(GA) and Tabu search(TS) method. Restoration and reconfiguration problems in distribution network are difficult to solve in short times, because distribution network supplies power for customers combined with many tie-line switches and sectionalizing switches. Furthermore, the solutions of these problems have to satisfy radial operation conditions and reliability indices. To overcome these time consuming and sub-optimal problem characteristics, this paper applied Genetic-Tabu algorithm. The Genetic-Tabu algorithm is a Tabu search combined with Genetic algorithm to complement the weak points of each algorithm. The case studies with 7 bus distribution network showed that not the loss reduction but also the reliability cost should be considered to achieve the economic service restoration and reconfiguration in the distribution network. The results of suggested Genetic-Tabu algorithm and simple Genetic algorithm are compared in the case study also.

  • PDF

ZD1839 and Cisplatin Alone or in Combination for Treatment of a Nasopharyngeal Carcinoma Cell Line and Xenografts

  • Gu, Wei-Guang;Huang, Yan;Yuan, Zhong-Yu;Peng, Rou-Jun;Luo, Hai-Tao;He, Zhi-Ren;Wang, Shu-Sen
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제14권3호
    • /
    • pp.1787-1790
    • /
    • 2013
  • This study evaluated the effects of ZD1839, an orally active, selective epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, on nasopharyngeal carcinoma (NPC) both in vitro and in vivo. Influence of ZD1839 alone or combined with cisplatin on the NPC cell line CNE2 was detected by MTT assay with flow cytometry assessment of cell cycle distribution and apoptosis rates. Nude mice NPC xenografts were also used to evaluate the effects of ZD1839 alone or combined with cisplatin. The Student's t test evaluated statistical significance. ZD1839 alone or combined with cisplatin inhibited CNE2 cell line proliferation. ZD1839 induced CNE2 cell cycle arrest in the G1 phase, and higher concentrations induced apoptosis. Xenograft tumors were significantly smaller when treated with 200 mg/kg ZD1839, cisplatin, or cisplatin combined with 100 mg/kg ZD1839 than untreated controls. ZD1839 (200 mg/kg) alone showed good tumor inhibition effects, reduction of tumor weights, and smaller tumor volume without loss of body weight. ZD1839 (200 mg/kg) might provide a good and effective therapeutic reagent for NPC.

다각 주사법을 이용한 비대칭 매연분포의 재구성 (Tomographic Reconstruction of Asymmetric Soot Structure from Multi-angular Scanning)

  • 이상민;황준영;정석호
    • 한국연소학회지
    • /
    • 제8권3호
    • /
    • pp.24-30
    • /
    • 2003
  • A convolution algorithm combined with Fourier transformation has been applied to the tomographic reconstruction of asymmetric soot structure to identify the local soot volume fraction distribution. Line-of-sight integrated data from light extinction measurement with multi-angular scanning formed basic information for the deconvolution. Multi-peak following interpolation technique was applied to obtain the effect of increasing number of scanning angles. Height-by-height reconstructed soot volume fraction distribution was compared with laser-induced incandescence signals.

  • PDF

지중배전시스템의 개선된 중성점 접지방식 제안과 실효성에 대한 해석적 평가 (Proposition of Improved Neutral Grounding Method and Analytical Evaluation on Practicality in Underground Distribution System)

  • 정석산;이종범;장성환;김용갑;권신남
    • 전기학회논문지
    • /
    • 제60권3호
    • /
    • pp.479-485
    • /
    • 2011
  • In 22.9kV underground distribution system, power cables are provided with multiple-point ground in which each neutral line of the distribution cable(A, B, C phases) and three-wire common grounded at every connecting section. But in such grounding methods, circulating current flows between the neutral wire and grounding wire. And power loss due to circulating current also occurs in all conductors. Therefore it is getting necessary reducing circulating current in underground distribution system. This paper presents improved grounding method to overcome such problems. The proposed grounding method eliminates circulating current in the neutral line effectively and is verified that there is no electrical problem or any ineffectiveness of operating protection systems. These analyses are carried out by EMTP/ATPDraw to compare each grounding methods in steady and transient state. This grounding method suggested in this paper can be applied on real distribution system after field tests considering elimination of circulating current was implemented.

지중배전계통에서 변압기 모델을 고려한 과도현상 해석 (Analysis of Transient Phenomena Considering Transformer Model in Underground Distribution Systems)

  • 윤창섭;이종범;송일근;김병숙
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2006년도 추계학술대회 논문집 전력기술부문
    • /
    • pp.151-153
    • /
    • 2006
  • This paper describes the transient phenomena considering transformer model in combined distribution systems with power cables. To evaluate the overvoltage, the change of transformer model and system structure are considered. Transformer parameters calculated by BCTRAN of EMTP are considered to evaluate surge generation in underground distribution systems when underground distribution system has various parameters. It is evaluated that overvoltage value increases and decreases according to the structure of system. However it is confirmed that there is not much effect to overvoltage as transformer is operated in distribution line.

  • PDF

신뢰도 지수를 고려한 계통의 Neural-Tabu 알고리즘을 이용한 최적 전송 경로 결정 (Neural-Tabu algorithm in optimal routing considering reliability indices)

  • 신동준;정현수;김진오
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1999년도 하계학술대회 논문집 C
    • /
    • pp.1245-1247
    • /
    • 1999
  • This paper describes the optimal reconfiguration of distribution network. The optimal routing of distribution network should provide electricity to customers with quality, and this paper shows that optimal routing of distribution network can be obtained by Neural-Tabu algorithm while keeping constraints such as line power capacity, voltage drop and reliability indices. The Neural-Tabu algorithm is a Tabu algorithm combined with Neural network to find neighborhood solutions. This paper shows that not only the loss cost but also the reliability cost should be considered in distribution network reconfiguration to achieve the optimal routing.

  • PDF