• 제목/요약/키워드: Prediction Accuracy

검색결과 3,787건 처리시간 0.03초

모델의 불확실성이 구조물의 손상예측정확도에 미치는 영향 (Damage Prediction Accuracy as a Function of Model Uncertainty in Structures)

  • 김정태
    • 전산구조공학
    • /
    • 제7권3호
    • /
    • pp.153-166
    • /
    • 1994
  • 구조물의 손상예측정확도를 모델불확실성의 함수로 산정하는 방법론이 제시되었다. 먼저, 구조물의 손상발생위치과 크기를 결정할 수 있는 알고리즘의 요약되고 모델불확실성과 손상발견정확도를 측정하는 방법들이 제시되었다. 다음으로, 실존구조물의 손상발견정확도에 미치는 모델불확실성의 영향을 산정하는 방법론이 제시되었다. 마지막으로, 한개의 진동모드가 측정된 Plate-Girder교량을 사용하여 이같은 산정방법론의 적합성이 예증되었다.

  • PDF

목표고객의 연령속성을 이용한 협력적 필터링 추천 시스템의 정확도 향상 (Accuracy improvement of a collaborative filtering recommender system using attribute of age)

  • 이석환;박승헌
    • 대한안전경영과학회지
    • /
    • 제13권2호
    • /
    • pp.169-177
    • /
    • 2011
  • In this paper, the author devised new decision recommendation ordering method of items attributed by age to improve accuracy of recommender system. In conventional recommendation system, recommendation order is decided by high order of preference prediction. However, in this paper, recommendation accuracy is improved by decision recommendation order method that reflect age attribute of target customer and neighborhood in preference prediction. By applying decision recommendation order method to recommender system, recommendation accuracy is improved more than conventional ordering method of recommendation.

이동열원을 고려한 레이저 보조가공에서 절삭공구와 홀더의 변형 예측에 관한 연구 (A Study on the Cutting Tool and Holder Deformation Prediction undergoing Laser-assisted Machining with Moving Heat Sources)

  • 정재원;이춘만
    • 한국정밀공학회지
    • /
    • 제26권9호
    • /
    • pp.127-134
    • /
    • 2009
  • Laser-assisted machining uses primarily laser power to heat the local area before the material is removed. It not only efficiently reduces the cutting force during the manufacturing process but also improves the machining characteristics and accuracy with regard to difficult-to-machine materials. The prediction of relative deformations between the cutting tool and workpiece is important to improve the accuracy of machined components. This paper presents the deformation errors caused for a cylindrical workpiece by thermal effects in the laser-assisted machine tool using finite element method. The results can be used to increase the cutting accuracy by compensating thermal distortion prior to laser-assisted machining.

비측량용 사진기에 의한 수렴사진의 정확도에 관한 연구 (A Study on the Accuracy of Convergent Photographs Using Non-Metric Camera)

  • 유복모;권현;유기윤
    • 한국측량학회지
    • /
    • 제7권2호
    • /
    • pp.63-68
    • /
    • 1989
  • 본 연구는 근거리 사진측량에 있어서 비측량용 사진기를 이용한 수렴사진에 대한 수학적 정확도 예측모델을 개발하고, 촬영거리와 수렴각의 변화에 따른 위치오차를 분석함으로써 정확도 예측모델의 타당성을 입증하였다. 본 연구에서 개발한 정확도 예측모델을 이용하여 주어진 촬영조건하에서 대상물에 대한 정확도를 예측할 수 있었으며, 또한 대상물의 평면 및 높이에 관한 요구되는 정확도에 따른 합리적인 촬영방법을 제안하였다.

  • PDF

Using Standard Deviation with Analogy-Based Estimation for Improved Software Effort Prediction

  • Mohammad Ayub Latif;Muhammad Khalid Khan;Umema Hani
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제17권5호
    • /
    • pp.1356-1376
    • /
    • 2023
  • Software effort estimation is one of the most difficult tasks in software development whereas predictability is also of equal importance for strategic management. Accurate prediction of the actual cost that will be incurred in software development can be very beneficial for the strategic management. This study discusses the latest trends in software estimation focusing on analogy-based techniques to show how they have improved the accuracy for software effort estimation. It applies the standard deviation technique to the expected value of analogy-based estimates to improve accuracy. In more than 60 percent cases the applied technique of this study helped in improving the accuracy of software estimation by reducing the Magnitude of Relative Error (MRE). The technique is simple and it calculates the expected value of cost or time and then uses different confidence levels which help in making more accurate commitments to the customers.

분기 명령어의 조기 예측을 통한 예측지연시간 문제 해결 (Early Start Branch Prediction to Resolve Prediction Delay)

  • 곽종욱;김주환
    • 정보처리학회논문지A
    • /
    • 제16A권5호
    • /
    • pp.347-356
    • /
    • 2009
  • 정교한 분기 예측기의 설계는 오늘날의 프로세서 성능 향상에 중요한 역할을 하게 되었다. 분기 예측의 정확도가 더욱 더 중요해 지면서 정확도의 향상을 위한 다수의 기법들이 제안되었지만, 기존의 연구들은 예측 지연 시간을 간과하는 경향이 있었다. 본 논문에서는 예측 지연 시간 문제를 해결하고자 조기 예측 기법 (ESP, Early Start Prediction)을 제안한다. 조기 예측 기법은 분기 예측에 있어서 활용되는 분기 명령어의 주소 대신 그것과 일대일 대응이 되는 기본 블록의 시작 주소 (BB_SA, Basic Block Start Address)를 이용한다. 즉, 분기 명령어의 주소가 사용되는 기존의 환경에서, BB_SA를 활용하여 조기 예측을 시작함으로써, 예측 지연 시간을 숨긴다. 또한 제안된 기법은 짧은 간격 숨김 기법(short interval hiding technique)을 통해 보다 더 나은 성능 향상을 기대할 수 있다. 실험 결과 본 논문에서 제안된 기법은 예측 지연 시간을 줄임으로써, 예측 지연 시간이 1 사이클인 이상적인 분기 예측기의 성능에 0.25% 이내로 근접한 IPC 결과를 얻었다. 또한 기본 블록의 시작주소와 분기 명령어 사이에 짧은 간격을 가질 경우에 대한 개선 방법을 추가적으로 적용시킬 경우, 기존의 방식과 비교하여 평균 4.2%, 최대 10.1%의 IPC 향상을 가져왔다.

Analysis of delay compensation in real-time dynamic hybrid testing with large integration time-step

  • Zhu, Fei;Wang, Jin-Ting;Jin, Feng;Gui, Yao;Zhou, Meng-Xia
    • Smart Structures and Systems
    • /
    • 제14권6호
    • /
    • pp.1269-1289
    • /
    • 2014
  • With the sub-stepping technique, the numerical analysis in real-time dynamic hybrid testing is split into the response analysis and signal generation tasks. Two target computers that operate in real-time may be assigned to implement these two tasks, respectively, for fully extending the simulation scale of the numerical substructure. In this case, the integration time-step of solving the dynamic response of the numerical substructure can be dozens of times bigger than the sampling time-step of the controller. The time delay between the real and desired feedback forces becomes more striking, which challenges the well-developed delay compensation methods in real-time dynamic hybrid testing. This paper focuses on displacement prediction and force correction for delay compensation in the real-time dynamic hybrid testing with a large integration time-step. A new displacement prediction scheme is proposed based on recently-developed explicit integration algorithms and compared with several commonly-used prediction procedures. The evaluation of its prediction accuracy is carried out theoretically, numerically and experimentally. Results indicate that the accuracy and effectiveness of the proposed prediction method are of significance.

전자상거래에서 지식탐사기법의 활용에 관한 연구 (An Application of Data Mining Techniques in Electronic Commerce)

  • 성태경;주석진;김중한;홍준석
    • 한국정보시스템학회지:정보시스템연구
    • /
    • 제14권2호
    • /
    • pp.277-292
    • /
    • 2005
  • This paper uses a data mining approach to develop bankruptcy prediction models suitable for traditional (off-line) companies and electronic (on-line) companies. It observes the differences in the composition prediction models between these two types of companies and provides interpretation of bankruptcy classifications. The bankruptcy prediction models revealed the major variables in predicting bankruptcy to be 'cash flow to total assets' and 'gross value-added to net sales' for traditional off-line companies while 'cash flow to liabilities','gross value-added to net sales', and 'current ratio' for electronic companies. The accuracy rates of final prediction models for traditional off-line and electronic companies were found to be $84.7\%\;and\;82.4\%$, respectively. When the model for traditional off-line companies was applied for electronic companies, prediction accuracy dropped significantly in the case of bankruptcy classification (from $70.4\%\;to\;45.2\%$) at the level of a blind guess ($41.30\%$). Therefore, the need for different models for traditional off-line and electronic companies is justified.

  • PDF

Prediction equations for digestible and metabolizable energy concentrations in feed ingredients and diets for pigs based on chemical composition

  • Sung, Jung Yeol;Kim, Beob Gyun
    • Animal Bioscience
    • /
    • 제34권2호
    • /
    • pp.306-311
    • /
    • 2021
  • Objective: The objectives were to develop prediction equations for digestible energy (DE) and metabolizable energy (ME) of feed ingredients and diets for pigs based on chemical composition and to evaluate the accuracy of the equations using in vivo data. Methods: A total of 734 data points from 81 experiments were employed to develop prediction equations for DE and ME in feed ingredients and diets. The CORR procedure of SAS was used to determine correlation coefficients between chemical components and energy concentrations and the REG procedure was used to generate prediction equations. Developed equations were tested for the accuracy according to the regression analysis using in vivo data. Results: The DE and ME in feed ingredients and diets were most negatively correlated with acid detergent fiber or neutral detergent fiber (NDF; r = -0.46 to r = -0.67; p<0.05). Three prediction equations for feed ingredients reflected in vivo data well as follows: DE = 728+0.76×gross energy (GE)-25.18×NDF (R2 = 0.64); ME = 965+0.66×GE-24.62×NDF (R2 = 0.60); ME = 1,133+0.65×GE-29.05×ash-23.17×NDF (R2 = 0.67). Conclusion: In conclusion, the equations suggested in the current study would predict energy concentration in feed ingredients and diets.

기존 계측 기반 침하 예측 이론식 한계점 도출 및 가중 비선형 회귀분석을 통한 침하 예측 개선방안 제시 (Analysis of the Limitations of the Existing Subsidence Prediction Method Based on the Subsidence Measurement Data and Suggestions for Improvement Method Through Weighted Nonlinear Regression Analysis)

  • 곽태영;홍성호;이주형;우상인
    • 한국지반공학회논문집
    • /
    • 제38권12호
    • /
    • pp.103-112
    • /
    • 2022
  • 본 연구에서는 시간-침하량 계측 데이터를 기반으로 한 기존 침하 예측 이론식을 확인하였다. 기존 계측 기반 침하 예측 이론식 중 쌍곡선법 및 Asaoka법이 정확도가 높게 나타났으며, 이외 방법은 정확도가 낮은 것으로 확인되었다. 이러한 분석 결과를 토대로 기존 침하 예측 방법의 한계점을 도출하였으며, 이러한 한계점을 보완할 수 있는 개선방안으로써 가중 비선형 회귀분석을 통한 침하 예측 방법을 제시하였다.