• 제목/요약/키워드: Experimental results

검색결과 64,782건 처리시간 0.073초

개방형 DC-DC 컨버터의 손실 분석에 관한 연구 (A Study on Loss Analysis of Open-Frame Type DC-DC Converter)

  • 연제선;이봉준;안태영
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 하계학술대회 논문집 B
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    • pp.1193-1195
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    • 2003
  • In this paper, to analyze efficiency characteristic, one of important factors in design of DC-DC converter prototype, theoretically derived power loss of individual components generating in DC-DC converter and compared theoretical results with experimental results. For evaluation of results, active clamp type Forward DC-DC converter with synchronous rectifier was composed of experimental converter. Efficiency result measured in experimental converter was compared with theoretical efficiency result derived in this paper. In comparative result, a fact that derived theoretical value and experimental value comparatively correspond have been able to verify.

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고속 회전시 광디스크의 플러터 불안정성: 이론적 예측과 실험 비교 (Flutter Instability of an Optical Disk Rotating at High Speeds: Theoretical Estimation and Experimental Results)

  • 김지덕;이승엽
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 추계학술대회논문집
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    • pp.777-783
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    • 2000
  • As the disk rotation speed increases in information storage devices, aerodynamically excited disk vibration is induced by airflow around the disk. This paper investigates both experimental and theretical studies on the flutter instability. From the experimental results using an ASMO disk, it is found that the three nodal diameter mode of the optical disk experiences its flutter instability around 8750 rpm. At the flutter speed, the amplitude of the corresponding mode increases dramatically and the backward natural frequency does not increase with increasing rotational speeds. The experimental results on flutter instability are compared with analytical predictions.

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다점 단순지지된 연속원통셸의 진동특성에 대한 실험적 고찰 (An Experimental Study on the Vibraton Characteristics of a Continuous Circular Cylindrical Shell with the Multi-simple Support)

  • 이영신;한창환;김근택;김현수
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 추계학술대회논문집
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    • pp.568-574
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    • 2000
  • This paper presents the vibration characteristics of a continuous circular cylindrical shell multi-simply supported at arbitrary axial positions for searching design parameters. In this modal test the impulse test method is applied to the excitation of experimental model. Natural frequencies are obtained from the peak points of frequency response function(FRF) through frequency analyzer and vibration behaviors are investigated. FE analysis is performed with ANSYS 5.5 to improve the reliability of experimental results. Their results are compared with experimental results. The effect of dynamic characteristics is analyzed for the number of support point on the shell.

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Experimental study on lead extrusion damper and its earthquake mitigation effects for large-span reticulated shell

  • Yang, M.F.;Xu, Z.D.;Zhang, X.C.
    • Steel and Composite Structures
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    • 제18권2호
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    • pp.481-496
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    • 2015
  • A Lead Extrusion Damper (LED) is experimentally studied under various frequencies and displacement amplitudes. Experimental results show that the force-displacement hysteresis loops of the LED are close to rectangular and the force-velocity hysteresis loops exhibit nonlinear hysteretic characteristic. Also, the LED can provide consistent energy dissipation without any stiffness degradation. Based on the experimental results, a mathematical model is then proposed to describe the effects of frequency and displacement on property of LED. It can be proved from the comparison between experimental and numerical results that the mathematical model can accurately describe the mechanical behavior of LED. Subsequently, the seismic responses of the Schwedler reticulated shell structure with LEDs are analyzed by ANSYS software, in which three different installation forms of LEDs are considered. It can be concluded that the LED can effectively reduce the displacement and acceleration responses of this type of structures.

CNN 기반 특징맵 사용에 따른 특징점 가시화와 에러율 (Feature Visualization and Error Rate Using Feature Map by Convolutional Neural Networks)

  • 진태석
    • 한국산업융합학회 논문집
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    • 제24권1호
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    • pp.1-7
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    • 2021
  • In this paper, we presented the experimental basis for the theoretical background and robustness of the Convolutional Neural Network for object recognition based on artificial intelligence. An experimental result was performed to visualize the weighting filters and feature maps for each layer to determine what characteristics CNN is automatically generating. experimental results were presented on the trend of learning error and identification error rate by checking the relevance of the weight filter and feature map for learning error and identification error. The weighting filter and characteristic map are presented as experimental results. The automatically generated characteristic quantities presented the results of error rates for moving and rotating robustness to geometric changes.

전단스팬비를 고려한 철근콘크리트 보의 전단강도 예측에 관한 연구 (A Study on the Shear Strength Prediction of Reinforced Concrete Beams Considering Shear Span Ratio)

  • 김상우;이정윤
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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    • pp.885-890
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    • 2001
  • For the shear strength prediction of reinforced concrete beams, this paper considered the bending moment effect. Experimental results of the thirty-seven reinforced concrete beams were compared with analytical results by the FA-STM, TATM and TATM considered bending moment effect. While Ratios of test results to analytical results by using the truss models does not considered the bending moment effect decreased as shear span ratio increased, those by using the proposed method considered that were almost constant regardless of the increase of the shear span ratio. Predicted results obtained from proposed method agreed well with the experimental results.

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Polyethersulfone 중공사 분리막에 의한 이산화탄소 분리 : 실험과 수치해석 비교 (Carbon Dioxide Separation by Hollow Fiber Membrane of Polyethersulfone : Comparison of Experimental Results with Numerical Analysis Data)

  • 이용택;송인호;안효성;전현수;정헌규;김정훈;이수복
    • 멤브레인
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    • 제17권2호
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    • pp.134-139
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    • 2007
  • 동일 운전 조건에서 폴리이서술폰 중공사 분리막을 이용하여 혼합 기체로부터 이산화탄소 분리 실험과 수치해석으로 얻어진 결과를 비교하였다. 순수한 기체의 투과도로부터 구한 이상 선택도를 활용한 예측값과 실험값이 많은 차이 가 있음을 확인할 수 있었다. 그러나 이산화탄소 투과도와 선택도를 혼합 기체 분리 실험 결과로부터 구한 후 공급 이산화탄소 몰 분율, 공급 압력과 투과측 압력의 함수로서 투과도와 선택도를 얻을 경우 수치해석 예측값과 실험값이 잘 일치하는 것을 확인하였다.

Effects of Sensory Integration Therapy with Sibling on Play Level and Time for Children with Disabilities

  • Chang, Ki-Yeon;Kim, Ki-Jong
    • 대한통합의학회지
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    • 제9권3호
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    • pp.1-8
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    • 2021
  • Purpose : There is a lack of research on this field in the Republic of Korea, especially those that have seen the effect of interaction between siblings through sensory integration therapy (SIT). Therefore, this study sought to find out the effectiveness of SIT with siblings through the Revised Knox Preschool Play Scale (RKPPS) and playtime. Methods : The experimental group consisted of 10 disabled children, and 10 normal siblings of the disabilities joined the program as a helper. In addition, 10 children with disabilities conducted the intervention as a control group. The difference between the experimental group and the control group is whether they participate with their sibling or not during the intervention period. The present study was conducted a SIT for 40 minutes per week for the experimental and the control group and then had 10 minutes of an interview with the parents of children with disabilities. A total of 10 programs were implemented for 10 weeks. Results : The experimental group showed statistically significant differences in space management, material management, pretense/symbolic, participation, and total scores. The control group showed significant differences between pre and post results in the participation and the total scores. The experimental group and the control group showed significant differences in the pre-post comparison results. The comparison of post-intervention between both groups of the RKPPS and playtime results showed a statistically significant increase in the experimental group. Conclusion : The sibling SIT showed better play level and time than the individual therapy. However, comparisons before and after the intervention in the level of play showed significant results only in participation and total scores in the control group. Clinically, it is recommended to make good use of sibling relationships when applying SIT, and if that is not possible, continuous observation is needed that children who received treatment become familiar with the environment in which they can be treated.

췌관 결찰에 의한 실험적 췌장염의 임상병리학적 관찰 (Clinicopathological observations on the experimental pancreatitis Induced by ligation of pancreatic ducts)

  • 성은주;이현범
    • 대한수의학회지
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    • 제34권2호
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    • pp.407-415
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    • 1994
  • Present experiments were undertaken in order to find out the most available diagnostic method for acute pancreatitis. Experimental dogs were divided into experimental group and control group. The experimental dogs were laparotomized and their pancreatic ducts were ligated for the induction of pancreatitis. The control dogs were laparotomized only for comparison. In addition to the complete blood count, serum amylase and lipase activities, serum glucose, total protein and albumin contents were measured daily for 11 days after the operation. Fecal fat droplet count by Sudan III staining and fecal trypsin activity examination by x-ray film digetion test were also undertaken daily. The results obtained were summarized as follows; 1. Serum amylase activities of the experimental group increased to peak on the third day and returned to the preoperative values on the eighth day. 2. Serum lipase activities of the experimental group increased to peak on the first day and returned to the preopertive values within six to eight days. 3. Serum glucose contents of the experimental group showed significant increse only on the first day. 4. Serum albumin contents of the experimental group decreased significantly during the experimental period. Whereas those of the control group significantly decreased only on the first day. 5. The experimental group showed marked leukocytosis, neutrophilia, and lymphopenia for the first 5 or 8 days. Whereas the control group showed only neutrophilia for the first 3 days. 6. The results of fecal fat droplet count showed some diagnostic value on the third and fourth day in only one experimental dog(No 1). No significant changes in the fecal trypsin activity were noticed in all dogs. 7. Histopathologically. all dogs of experimental group showed changes of pancreatitis. However the degree of the pancreatic lesion was not pararell to the degree of the serum amylase or lipase activity changes.

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구획실 내 가연물들의 화재거동에 대한 B-RISK와 FDS 연계 화재 시뮬레이션 예측성능 평가 (Evaluation of the Prediction of B-RISK-FDS-Coupled Simulations for Multi-Combustible Fire Behavior in a Compartment)

  • 백빛나;오창보
    • 한국화재소방학회논문지
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    • 제33권4호
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    • pp.50-58
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    • 2019
  • 구획실 내 가연물들의 화재거동에 대한 B-RISK의 예측성능을 Fire dynamics simulator (FDS)와 연계하여 검토하였다. 먼저 열발생률(Heat release rate, HRR)에 대한 B-RISK의 예측성능을 검토하기 위해 가연물 한 세트의 실험에서 측정된 HRR 값과 디자인 화재곡선을 B-RISK의 입력조건으로 사용하여 가연물 두 세트에 대한 HRR 곡선을 계산하고 실험에서 측정된 가연물 두 세트의 HRR 값과 비교하였다. B-RISK 결과와 실험결과를 비교하여 B-RISK가 화재성장률에 대한 예측은 어렵지만 최대 HRR 값과 총 열발생량에 대해서는 충분히 예측할 수 있음을 확인하였다. 그리고 B-RISK 계산을 통해 예측된 HRR 값을 FDS의 입력조건으로 사용하여 계산된 결과와 실험결과를 비교하여 B-RISK 계산을 통해 예측된 HRR 값의 화재거동에 대해 검토하였다. 실험에서 측정된 온도 및 화학종 농도 결과와 비교하여 화재성장구간에 대해 차이가 있는 것을 확인하였지만 예측된 HRR 값에서 Percentile이 약 70%인 HRR 값을 사용하더라도 충분히 전체적인 화재거동을 예측할 수 있음을 확인하였다.