• 제목/요약/키워드: responsible engineers

검색결과 293건 처리시간 0.025초

배전 계토의 손실 최소 재구성을 위한 시뮬레이티드 어닐링의 구현 (Implementation of Simulated Annealing for Distribution System Loss Minimum Reconfiguration)

  • 전영재;최승규;김재철
    • 대한전기학회논문지:전력기술부문A
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    • 제48권4호
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    • pp.371-378
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    • 1999
  • This paper presents an efficient algorithm for loss reduction of distribution system by automatic sectionalizing switch operation in large scale distribution systems of radial type. Simulated Annealing algorithm among optimization techniques can avoid escape from local minima by accepting improvements in cost, but the use of this algorithm is also responsible for an excessive computation time requirement. To overcome this major limitation of Simulated Annealing algorithm, we may use advanced Simulated Annealing algorithm. All constaints are divided into two constraint group by using perturbation mechanism and penalty factor, so all trail solutions are feasible. The polynomial-time cooling schedule is used which is based on the statistics calculation during the search. This approaches results in saving CPU time. Numerical examples demonstrate the validity and effectiveness of the proposed methodology.

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전력기기 적용을 위한 초전도 세라믹의 전기자기적 특성 (Electromagnetic Characteristics of Superconducting Ceramics for Electrical Power Devices)

  • 이상헌
    • 전기학회논문지
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    • 제60권2호
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    • pp.349-351
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    • 2011
  • The formation of oxide superconducting phase fabrication of superconducting wire materials and fabrication of precise superconducting material were studied for developing superconductor application technique. The $ZrO_2$ addition reduced the particle size $BaZrO_3$ trapped in the matrix after the sintering growth. The added $ZrO_2$ was converted to fine particles of $BaZrO_3$ which is the conventional sintering temperature for YBaCuO, $Y_2Ba_1Cu_1O_5$ and CuO are formed as by products of the reaction between $ZrO_2$ and YBaCuO phase. The formation of highly $BaZrO_3$ particle appears to be responsible for the refinement of $BaZrO_3$ phase after the citric acid sintering process.

기술 표준 제정과 거버넌스 접근법: 전기공사 마스터 스펙 사례 (A Study of Technical Standard Making from Governance Perspective: The Case of Master Spec. in Electrical Construction)

  • 조현석
    • 전기학회논문지
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    • 제61권5호
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    • pp.770-776
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    • 2012
  • For a few recent years, KECA(Korea Electrical Contractor Association) has promoted a project to establish an electrical construction specification called Master Spec. This paper analyses the characteristics of standards-making process of the Master Spec. as an umbrella technical standard in electrical construction industry in Korea. This paper argues that even if the Master Spec. is recognized to be technical standards, the standards-making process involves both technical and social practices when viewed from social construction theory and governance perspective. This aspect of social practices in technical standards making should be well understood because various stakeholders in terms of interests, resources, and motives try to influence the process positively and negatively. KECA in responsible for enactment of the Mater Spec. should be very thoughtful in building consensus first of all among electrical contractors, managing relationship with concerned government officials, and dealing with potential deviant groups as well as in pooling expertises and developing technical knowledge needed for designing technical specification.

MeV 이온주입에 의한 Retrograde Triple-well 형성시 발생하는 결함제어 (Control of Defect Produced in a Retrograde Triple Well Using MeV Ion Implantation)

  • 정희석;고무순;김대영;류한권;노재상
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.17-20
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    • 2000
  • This study is about a retrograde triple well employed in the Cell tr. of next DRAM and flash memory. Triple well structure is formed deep n-well under the light p-well using MeV ion implantation. MeV P implanted deep n-well was observed to show greatly improved characteristics of electrical isolation and soft error. Junction leakage current, however, showed a critical behavior as a function of implantation and annealing conditions. {311} defects were observed to be responsible for the leakage current. {311} defects were generated near the R$\_$p/ (Projected range) region and grown upward to the surface during annealing. This is study on the defect behavior in device region as a function of implantation and annealing conditions.

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초고주파대역용 소자를 위한 FeTaN 박막의 이방자계의 영향 (The effect of anisotropy field of FeTaN thin films for ultraigh-hfrequency applications)

  • 류성룡;배석;정종한;김충식;남승의;김형준
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.303-305
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    • 2000
  • The effect of anisotropy field on the high frequency magnetic characteristics of FeTaN films was investigated. Those films show good magnetic properties : 4$\pi$Ms of 13KG, Hc of 0.6 Oe, effective permeability(${\mu}$') of 800 with a stable frequency response up to 800MHz. The films also show a large anisotropy field(Hk) over 21Oe. It result from the increased anisotropy of patterned FeTaN films. The combination of high saturation magnetization and relatively high Hk in these films is believed to the partly responsible for FeTaN for the excellent high-frequency behavior.

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EPDM/Clay 컴파운드의 절연특성 (Dielectric Properties of EPDM/Clay Compounds)

  • 조용석;이헌주;전영준;이철호;김상욱
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 춘계학술대회 논문집 유기절연재료 방전 플라즈마
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    • pp.13-17
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    • 2000
  • In EPDM/ATH/clay compounds, clay rich compounds show lower tensile strength due to lower cure state derived from acidic nature of clay filler. As the ATH is replaced by clay, dielectric properties such as $tan{\delta}$, dielectric constant and volume resistivity improve, Polar nature of ATH is responsible for the higher hot water ingress. The amount of charge in the EPDM/clay compounds increases with an increase of clay concentration.

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마찰 하중에 의한 HMX, RDX, AP기반 고에너지물질의 발화특성모델링 연구 (Friction-induced ignition and initiation modeling of HMX, RDX and AP based energetic materials)

  • 곽민철;유지창;여재익
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2008년도 제31회 추계학술대회논문집
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    • pp.283-287
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    • 2008
  • 충격과 관통 같은 에너지의 소실은 열을 발생시키며 이를 통하여 기계적 변화와 더불어 열적 변화를 유발하게 된다. 고에너지 물질의 경우 이런 마찰에 의해 발생되는 열이 점화 원인이 될 수 있다. 그래서 본 연구에는 BAM 마찰 실험을 통하여 획득된 HMX, RDX 그리고 AP를 기반으로 한 추진제의 마찰 점화 실험 자료를 바탕으로 하여 마찰에 의한 고에너지 물질의 점화를 모델링한다.

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POLYVINYLPYRROLIDONE METAL COMPLEXES. FORMATION STABILITY AND THEIR BIOLOGICAL ACTIVITY

  • Lee, V. A.;S. Sh. Rashidova
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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    • pp.463-465
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    • 1998
  • The peculiarities of the polyvinylpyrrolydone (PVP) interaction with transition metal ions of the first row in solution were studied. It was shown that PVP macromolecules due to their swelling conformation in organic solvents form the stable metal complexes. Metal ions were bond with oxygen and nitrogen atoms of PVP lactam rings. In water solution every metal ion interacts with one or two oxygen atoms out of 10-12 monomer units of the polymer. The additional contraction of PVP macromolecule coils in water have been found out by dissolving of the polymer metal complexes (PMC) synthesized in organic media. Toxicity, blood forming and immune stimulating activity and pharmaco-kinetic too of obtained polymers and their metal completes have been investigated. The factors and effects that responsible fur changing of PMC physical-chemical and biological properties have been estimated.

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계약 조항의 애매모호성에 의해서 발생되는 공기지연 클레임의 책임 당사자 확인 프로세스 (The Process of Identifying the Responsibility Party of Caused Delay Claim by Ambiguity of the Conditions of the Contract)

  • 이치주;권태욱;고훈석
    • 한국건축시공학회지
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    • 제20권6호
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    • pp.527-535
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    • 2020
  • 본 연구에서는 EPC/턴키 프로젝트에서 발생 가능한 클레임의 주요 원인들을 발주자와 건설사의 관점에서 분석하였다. 그 원인들은 EPC/턴키 프로젝트의 표준 계약서인 FIDIC 실버 북을 기반으로 도출하였다. 발생 빈도가 가장 높은 클레임의 유형은 공기지연으로 분석되었다. 그 후, 가장 발생 빈도가 높은 클레임에 대한 책임이 계약 당사자간에 누구에게 있는지를 분석하는 프로세스를 제안하였다. 제안된 프로세스는 2010년에 수행한 2건의 대규모 EPC/턴키 프로젝트들과 FIDIC 실버 북의 공기지연 클레임에 관련된 계약 조항들을 기반으로 제안되었다. 제안된 프로세스는 발주자가 공사기간 지연에 대해 배상금을 설정하는지에 대한 의도에 따라 분류된다. 본 연구의 주요 기여도는 사례 프로젝트의 계약 조건을 기반으로 다양한 계약 유형에 적용할 수 있는 프로세스를 제안한 것이다. 뿐만 아니라, 계약서 작성 전에 발생 가능한 클레임의 유형을 확인할 수 있고, 공사기간 지연 클레임이 발생할 경우에 책임 당사자를 예측할 수 있으므로, 명확한 계약서 작성에도 기여할 수 있을 것이다.

POSSIBILITIES TO IMPROVE TRANSIENT GEAR SHIFT NOISE (SHIFT CLONK) IN A PASSENGER CAR

  • BIERMANN J. W.;REITZ A.
    • International Journal of Automotive Technology
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    • 제6권1호
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    • pp.23-28
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    • 2005
  • The presented investigation of shift clonk in a vehicle with front-wheel drive shows how a detailed analysis of the complete acoustic system with respect to excitation, transfer and radiation foremost enables possibilities of noise reduction to be worked out. One of the most important basics for the shift clonk analysis was a synchronous measurement of both, torsional vibrations in the drive train on the excitation side as well as airborne and structure-borne noise signals on the transfer and radiation side. Thus, root causes could be identified and improvement measures of the internal shift system could be worked out. An analysis of the transfer paths by means of airborne and structure borne noise measurements made evident that the side shafts were responsible for the disturbing frequencies in the transfer paths. With the help of the FE-simulation it was possible to develop measures of structure optimisation for the side shaft system. The realisation of these measures clearly reduced the shift-noises in the vehicle interior.