• 제목/요약/키워드: Song Mode

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혼합모드 단일과대하중 하에서 피로균열 전파거동의 예측 (Prediction of Fatigue Crack Propagation Behavior Under Mixed-Mode Single Overload)

  • 이정무;송삼홍
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 추계학술대회
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    • pp.359-364
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    • 2004
  • In this study, experiments were tried on the mixed-mode I+II single overloading model which changes the loading mode of overload and fatigue load. Aspects of deformation field in front of the crack which is formed by mixed-mode I+II single overloading were experimentally studied. Then the shape and size of mixed-mode plastic zone were approximately calculated. The propagation behavior of fatigue crack was examined under the test conditions combined by changing the loading mode. The behavior of fatigue cracks were greatly affected by shapes of plastic deformation field and applying mode of fatigue load. Accuracy of prediction and evaluation for fatigue life may be improved by considering all aspects of deformation and behavior of fatigue cracks.

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혼합모드 하중 하에서의 균열성장 중 피로파단면 마찰과 균열닫힘효과의 상호관계 (The Correlation between Fatigue Fracture Crack Surface Friction and Crack Closure Effect in Crack Growth under Mixed-mode loading)

  • 서기정;송삼홍;이정무
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 추계학술대회
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    • pp.214-219
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    • 2004
  • Crack tip behavior of single mode loading condition(mode I)depend on tensile loading component but one of mixed mode loading condition(mode I+II) have influenced on shear loading component like the practical structure. Because crack closure is caused by shear loading component under mixed-mode loading a research on the behavior in the stage of crack initiation and propagation require to be evaluate about crack closure effect by fatigue crack surface friction. For that reasion we examined the behavior at the crack tip by direct measuring method. Measured behavior at the crack tip was analyzed through vector crack tip displacement. As a result, crack propafation equation was corrected by considering with crack closure effect. In addition we compared fatigue fracture crack surface and crack closure level.

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혼합모드 단일과대하중 하의 피로균열 전파거동에 관한 실험적 연구 (An Experimental Study on the Fatigue Crack Propagation Behavior Under Mixed-Mode Single Overload)

  • 송삼홍;이정무;홍석표
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.119-124
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    • 2003
  • In this study, retardation behavior of fatigue crack under single overloading of the mixed mode I+II state was experimentally investigated. To produce single overload in the mixed mode I+II state, the compact tension shear (CTS) specimen and loading device were used. The propagation tests for fatigue crack were performed under mode I loading overloading afterwards. We examined the observed deformation aspects, variation of fatigue life and crack propagation rate, and the aspects of retardation behavior from tests. The retardation effect of mixed-mode single overload on fatigue crack propagation behavior was smaller than that of mode I single overload. It has been confirmed that the retardation behavior did not immediately appear and the retardation length was short when the component of mixed-mode overload was changed.

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간접전류제어방식 병렬형 계통연계 인버터의 무순단 모드절환 (Seamless Mode Transfer of Indirect Current Controlled Parallel Grid-Connected Inverters)

  • 송인종;최준수;임경배;최재호
    • 전력전자학회논문지
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    • 제24권5호
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    • pp.334-341
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    • 2019
  • This study proposes the control strategy for the seamless mode transfer of indirect current controlled parallel grid-connected inverters. Under the abnormal grid condition, the grid-connected inverter can convert the operation mode from grid-connected to stand-alone mode to supply power to the local load. For a seamless mode transfer, the time delay problems caused by the accumulated control variable error must be solved, and the indirect current control method has been applied as one of the solutions. In this study, the design of control parameters for the proportional-resonant-based triple-loop indirect current controller and the control strategy for the seamless mode transfer of parallel grid-connected inverters are described and analyzed. The validity of the proposed mode transfer method is verified by the PSiM simulation results.

Validity of the Korean Version of the Schema Mode Inventory (SMI)

  • Song, Younghee;Lee, Eunhee
    • International Journal of Advanced Culture Technology
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    • 제8권1호
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    • pp.248-256
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    • 2020
  • This study investigated whether the schema modes have validity in Korean adults. We examined the validity and reliability of the Schema Mode Inventory (SMI) in a Korean adult sample (N = 768; Mean age = 22.29 years; range = 19-55 years; 69.3% Males). Psychometric properties, such as factor structure, internal reliability, as well as intercorrelations among subscales were assessed. Confirmatory factor analyses yield satisfying fits for a 61-item Korean Schema Mode Inventory. Thirteen Schema Mode Inventory scales were found to have adequate reliability of the original 14 schema factors. Furthermore, the SMI scales differentiated between depressed and non-depressed participants as theoretically predicted. These findings imply that the SMI is a sound instrument to measure the schema mode model in a Korean setting for assessment prior to schema therapy.

Development of Desk top Tug-barge Simulator and Evaluation Module

  • Jeong, Tae-Gwoen;Song, Chae-Uk;Chen, Chao;Lee, Shin-Geol;Lee, Jeong-Jin
    • 한국항해항만학회지
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    • 제35권2호
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    • pp.113-119
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    • 2011
  • This paper is a part of the development on the safe navigation model of tugs and barges in Korea waters. desk-top tug-barge simulator is to train the crew of tugs and barges, especially tugs' crew. It is connected with steering and engine telegraph console and winch control console, and can describe three types of operation mode for a tug-barge working unit, towing mode, side by side and push mode. It can also record and assess each simulation run. The evaluation module can confirm the result of a finished simulation run and help trainees to find and correct their faults, and it is composed of result evaluation and process evaluation.

모드 II 하중을 받는 CTS 시험편의 피로균열 전파거동에 관한 실험적 연구 (An Experimental Study on the Fatigue Crack Propagation Behavior in CTS Specimen under Mode II Loading)

  • 송삼홍;이정무
    • 대한기계학회논문집A
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    • 제27권7호
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    • pp.1217-1226
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    • 2003
  • The purpose of this paper is to investigate fatigue crack behavior under shear(Mode II) loading. Various specimens and devices have been used in order to produce Mode II loading in fatigue experiments for shear crack propagation. But, there is not sufficient comparisons of experimental results between Mode II and others loading modes, because of characteristics of applied loads and specimens. So, compact tension shear(CTS) specimens were used in this paper to investigate the propagation behavior of Mode II by comparing the experimental results between loading modes. We firstly observed the characteristics which was showed in Mode II experiment using CTS specimens. The experimental results under Mode II loading were compared with fatigue crack behavior under Mode I and Mixed-mode I+II loading. The characteristics for initiation and propagation behavior under Mode II loading was investigated by such comparisons.

성덕대왕신종의 맥놀이 지도 (Beat Maps of King Song-Dok Bell)

  • 김석현
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 추계학술대회논문집
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    • pp.498-504
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    • 2002
  • Vibration beat phenomenon is theoretically investigated on a slightly asymmetric cylindrical shell, which is a simplified model of Korean bell. Mode pairs of the slightly asymmetric shell are obtained by receptance analysis and impulse response of the shell is derived using modal expansion and Laplace transform. Based on the impulse response model, beat mapping method is proposed to explain the reason that the beat of a bell vibration shows periodic distribution on the circumference. Beat characteristics of King Song-Dok Bell are explained in detail using the beat map and the measured modal data.

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Meshless local collocation method for natural frequencies and mode shapes of laminated composite shells

  • Xiang, Song;Chen, Ying-Tao
    • Structural Engineering and Mechanics
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    • 제51권6호
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    • pp.893-907
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    • 2014
  • Meshless local collocation method produces much better conditioned matrices than meshless global collocation methods. In this paper, the meshless local collocation method based on thin plate spline radial basis function and first-order shear deformation theory are used to calculate the natural frequencies and mode shapes of laminated composite shells. Through numerical experiments, the accuracy and efficiency of present method are demonstrated.

Reputation Rating Mode and Aggregating Method of Online Reputation Management System

  • Song, Guang-Xing
    • 한국산업정보학회:학술대회논문집
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    • 한국산업정보학회 2007년도 춘계학술대회
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    • pp.190-196
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    • 2007
  • With the rapid development of electronic commerce, online reputation management systems are of increasing importance in building trust and managing risk. Reputation rating mode and aggregating method are the most crucial parts of a reputation management system. In this paper, we analyze the merits and disadvantages associated with the rating mode and aggregating approach of current reputation management systems, and put forward some suggestions. These suggestions are helpful in improving current reputation management systems and developing new reputation management systems.

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