• 제목/요약/키워드: change core method

검색결과 354건 처리시간 0.027초

Modelling of headed stud in steel-precast composite beams

  • El-Lobody, Ehab;Lam, Dennis
    • Steel and Composite Structures
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    • 제2권5호
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    • pp.355-378
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    • 2002
  • Use of composite steel construction with precast hollow core slabs is now popular in the UK, but the present knowledge in shear capacity of the headed shear studs for this type of composite construction is very limited. Currently, all the information is based on the results obtained from experimental push-off tests. A finite element model to simulate the behaviour of headed stud shear connection in composite beam with precast hollow core slabs is described. The model is based on finite element method and takes into account the linear and non-linear behaviour of all the materials. The model has been validated against the test results, for which the accuracy of the model used is demonstrated. Parametric studies showing the effect of the change in transverse gap size, transverse reinforcement diameter and in-situ concrete strength on the shear connection capacity are presented.

철도 변전설비를 위한 싸이리스터 이중 컨버터 전력 시스템의 제어 기법 (Control Algorithm of Thyristor Dual Converter Power System for Railway Power Substations)

  • 한성우;이창희;김영우;문동옥
    • 전력전자학회논문지
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    • 제20권6호
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    • pp.573-579
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    • 2015
  • A control algorithm of thyristor dual converter power system is proposed in this study for a railway power substation. The thyristor dual converter can use regenerative power without an additional system using control algorithm. An autonomous voltage and mode change method is also proposed to provide uninterrupted power to the railway. A 10 kW reduced model of the thyristor dual converter power system is built and tested to verify the validity of the proposed control algorithm.

BSCCO-2223계 초전도 선재의 기계적 가공이 임계 전류 밀도에 미치는 영향 (The effect of mechanical processing in BSCCO-2223 tape on critical current density)

  • 임성우;강형곤;최명호;박경국;한병성
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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    • pp.355-357
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    • 1998
  • BSCCO-2223 superconducting tape made by PIT method can be influenced in the critical characteristics by the heat treatment and the mechanical processing. Particulary, it has been reported that the mechanical deformation affects the core density, texture of the core, sausaging and so on. Therefore the accurate control of the deformation process is very important to achieve high J$\sub$c/. In this study, we measured the J$\sub$c/ variation for different rolling reduction rate and investigated the change of core shape to compare the formation of sausaging.

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소프트웨어 프로덕트 라인에서 핵심 자산으로서 요구사항을 관리하는 방법 (An Approach to Managing Requirements as a Core Asset in Software Product-Line)

  • 문미경;염근혁
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제31권8호
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    • pp.1010-1026
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    • 2004
  • 소프트웨어 프로덕트 라인 공학의 목표는 일련의 유사한 소프트웨어 시스템의 공통성과 구별되는 특성을 이해하고 제어함으로써 시스템의 체계적인 개발을 지원하는 것이다[1]. 이것은 소프트웨어 개발 시 나오는 산출물들을 핵심 자산으로 만들어 놓고 이를 체계적으로 재사용 할 수 있도록 지원하기 위한 프레임웍 역할을 한다. 현재 많은 기술들이 프로덕트 라인 공학 관련하여 연구되고 있지만, 그 초점이 소프트웨어 아키텍쳐나 상세 설계 또는 코드에 맞추어져 있다[2]. 소프트웨어 프로덕트 라인 공학에서는 컴포넌트의 공급, 조립뿐만 아니라 조립공정까지 특정 요구나 변화에 신속히 적응할 수 있도록 관리하는 것이 중요한데, 이는 요구사항 분석 단계에서부터 이루어져야 한다. 소프트웨어 프로덕트 라인 공학에서 요구사항은 전통적인 시스템 개발에서와 마찬가지로 모든 개발의 기초가 되는 부분이며, 다른 핵심 자산의 공통성과 가변성의 성질을 결정짓게 만들 수 있는 기준이 된다. 그러나 요구사항들을 다 반영하기도 전에 변경이 발생하는 수많은 경험을 해 온 것처럼, 올바른 요구사항을 획득하고 이를 분석, 관리한다는 것은 결코 쉬운 일이 아니다. 특히, 여러 개의 시스템을 개발할 때 사용할 요구사항은 공통성과 가변성의 속성을 가지게 된다. 그러므로 계획할 수 있는 변화에는 충분히 안정적이면서, 반면에 예측하지 못하는 변화에 잘 적응하고 개조될 수 있도록 유연성을 지닌 핵심 요구사항을 개발, 관리하기 위한 체계적인 방법이 필요하다. 본 논문에서는 소프트웨어 프로덕트 라인에서 핵심 자산의 하나인 도메인 요구사항을 관리하는 방법에 대하여 제안한다. 이를 통해 도메인 요구사항에 대한 재사용성을 중대시키고 시스템의 목표를 정확히 세우는 데 투자되는 많은 시간과 노력을 감소시켜 준다. 이는 결과적으로 소프트웨어 개발 시간과 비용을 줄이고, 생산성을 향상시키는 등의 장점을 가져다준다.

Influence of modification in core building procedure on fracture strength and failure patterns of premolars restored with fiber post and composite core

  • Kim, Young-Hoi;Lee, Jong-Hyuk
    • The Journal of Advanced Prosthodontics
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    • 제4권1호
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    • pp.37-42
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    • 2012
  • PURPOSE. The influence of the modified process in the fiber-reinforced post and resin core foundation treatment on the fracture resistance and failure pattern of premolar was tested in this study. MATERIALS AND METHODS. Thirty-six human mandibular premolars were divided into 4 groups (n = 9). In group DCT, the quartz fibre post (D.T. Light-post) was cemented with resin cement (DUO-LINK) and a core foundation was formed with composite resin (LIGHT-CORE). In group DMO and DMT, resin cement (DUO-LINK) was used for post (D.T. Lightpost) cementation and core foundation; in group DMO, these procedures were performed simultaneously in one step, while DMT group was accomplished in separated two steps. In group LCT, the glass fiber post (LuxaPost) cementation and core foundation was accomplished with composite resin (LuxaCore-Dual) in separated procedures. Tooth were prepared with 2 mm ferrule and restored with nickel-chromium crowns. A static loading test was carried out and loads were applied to the buccal surface of the buccal cusp at a 45 degree inclination to the long axis of the tooth until failure occurred. The data were analyzed with MANOVA (${\alpha}$= .05). The failure pattern was observed and classified as either favorable (allowing repair) or unfavorable (not allowing repair). RESULTS. The mean fracture strength was highest in group DCT followed in descending order by groups DMO, DMT, and LCT. However, there were no significant differences in fracture strength between the groups. A higher prevalence of favorable fractures was detected in group DMT but there were no significant differences between the groups. CONCLUSION. The change of post or core foundation method does not appear to influence the fracture strength and failure patterns.

Analysis of Fuelling Sequence and Fatigue Life for 4-Bundle Shift Refuelling Scheme in CANDU6 NPP

  • Namgung, Ihn
    • Nuclear Engineering and Technology
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    • 제34권2호
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    • pp.176-185
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    • 2002
  • A 4-bundle shift refuelling method of CANDU6 F/H (Fuel Handling) System is analyzed to assess the operational flexibility and capacity of F/H system. The current 8-bundle shift refuelling scheme requires to refuel eight fuel bundles from a single fuel channel, and to refuel 14 fuel channels in a week on average assuming that the reactor is in a steady state. The analysis showed that the 4-bundle shift refuelling method increases F/M (Fuelling Machine) duty cycle and operator load. However, the fuellin’g method change from the 8- to 4-bundle shift refuelling ill not require additional team of operators. A marginal increase in the maintenance cost may be resulted in by the change of fuelling method and the increase of fatigue usage factors requires some components to be replaced during the FM lifetime.

졸-겔법을 이용한 실리카 핵을 가지는 하이브리드 안료의 제조와 잉크젯 분산 잉크로서 응용 (Preparation of Silica Core-Hybrid Pigment via Sol-Gel Process and It's Application for Inkjet Dispersion Ink)

  • 전영민;김종규;공명선
    • 한국재료학회지
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    • 제16권10호
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    • pp.599-605
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    • 2006
  • N-(3-triethoxysilylpropyl)-1,4-diaminoanthrquinone-2,3-dicarboximide (TESP-DADI), an organic blue pigment, has been prepared and incorporated into silica solid matrix reacting triethyl orthosilicate (TEOS) via sol-gel method. Morphology and microstructure of resulting hybrid pigment were studied employing SEM and TEM. The micrographs and particle size distributions showed that uniform pigment can be obtained employing TEOS-based sol-gel method forming silica core. Particle size distribution of dispersed pigment in water was examined using the technique of dynamic light scattering. The ensuing pigment dispersion ink was subjected to various physicochemical evaluation such as viscosity, surface tension, inkjet stability, storage stability, and color change as inkjet ink using spectrophotometric, and microscopic techniques.

피레토세라피를 이용(利用)한 건선환자(乾癬患者) 62명(名)에 대(對)한 임상보고(臨床報告) (Clinical study about 62 cases of psoriasis patient using pyretotherapy)

  • 강재춘
    • 한방안이비인후피부과학회지
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    • 제25권4호
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    • pp.35-44
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    • 2012
  • Objectives : This study was aimed to evaluate the treatment effect of psoriasis patient using pyretotherapy. Methods : The clinical study was performed using retrospective observational research method. Treatment method was pyretotherapy that optimized core temperature through herbs therapy, food therapy, excercise and life style change. In other aspects, pyretotherapy is skin cure therapy that rise core temperature, down skin temperature and open sweat gland. Results : 1. 40s years showed the most coming of clinic in the distribution of age of psoriasis patient. 2. Board type showed the most number in the classification of psoriasis. 3. Pyretotherapy was very effective results in psoriasis patient treatment. 4. Pyretotherapy showed effects of rising axillary temperature and moving facial high skin temperature toward abdominal portion. Conclusions : The author is able to say that it is possible for pyretotherapy to become new skin therapy for many skin disease, especially psoriasis.

The optimization study of core power control based on meta-heuristic algorithm for China initiative accelerator driven subcritical system

  • Jin-Yang Li;Jun-Liang Du;Long Gu;You-Peng Zhang;Cong Lin;Yong-Quan Wang;Xing-Chen Zhou;Huan Lin
    • Nuclear Engineering and Technology
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    • 제55권2호
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    • pp.452-459
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    • 2023
  • The core power control is an important issue for the study of dynamic characteristics in China initiative accelerator driven subcritical system (CiADS), which has direct impact on the control strategy and safety analysis process. The CiADS is an experimental facility that is only controlled by the proton beam intensity without considering the control rods in the current engineering design stage. In order to get the optimized operation scheme with the stable and reliable features, the variation of beam intensity using the continuous and periodic control approaches has been adopted, and the change of collimator and the adjusting of duty ratio have been proposed in the power control process. Considering the neutronics and the thermal-hydraulics characteristics in CiADS, the physical model for the core power control has been established by means of the point reactor kinetics method and the lumped parameter method. Moreover, the multi-inputs single-output (MISO) logical structure for the power control process has been constructed using proportional integral derivative (PID) controller, and the meta-heuristic algorithm has been employed to obtain the global optimized parameters for the stable running mode without producing large perturbations. Finally, the verification and validation of the control method have been tested based on the reference scenarios in considering the disturbances of spallation neutron source and inlet temperature respectively, where all the numerical results reveal that the optimization method has satisfactory performance in the CiADS core power control scenarios.

필댐 보수보강후 시간경과에 따른 효과 분석 (Effect analysis by time passage after Repair & Reinforcement of Fill Dams)

  • 김재홍;오병현;임은상;홍원표
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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    • pp.697-703
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    • 2008
  • Excessive water leakage phenomenon happens through damage of nation core zone of about 17,000 storage of water facilities or collapse of dam is worried, is being damaged or enforce dilapidated fill dam core zone's repair reinforcement. Example that use grouting method of construction considering construction and economic performance etc. recently by repair reinforcement way about defect of dam is increased. Permeation grouting method repair & reinforcement of fill dam countermeasure is preferred in nation. Do that is economical to decide these repair reinforcement effect and grouting effect estimation method that do not give damage to dam is effective. Therefore, observing electricity resistivity Survey change of dam since grouting reinforcement using Electric resistivity Survey inquiry of seismic survey method in this research, Wished to verify grouting effect whether is possible as Electric resistivity Survey, and study whether integrity of dam through repair reinforcement defined.

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