• 제목/요약/키워드: Model Uncertainty

검색결과 2,307건 처리시간 0.028초

A Study on Fuzzy Ranking Model based on User Preference

  • Kim Dae-Won
    • 한국지능시스템학회논문지
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    • 제16권3호
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    • pp.326-331
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    • 2006
  • A great deal of research has been made to model the vagueness and uncertainty in information retrieval. One such research is fuzzy ranking models, which have been showing their superior performance in handling the uncertainty involved in the retrieval process. In this study we develop a new fuzzy ranking model based on the user preference. Through the experiments on the TREC-2 collection of Wall Street Journal documents, we show that the proposed method outperforms the conventional fuzzy ranking models.

품질기능전개에서 입력정보의 불확실성에 대한 고찰 (Consideration of Uncertainty in input information of QFD)

  • 김덕환;김광재;민대기
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회/대한산업공학회 2005년도 춘계공동학술대회 발표논문
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    • pp.566-573
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    • 2005
  • Quality function deployment (QFD) is a useful tool for ensuring quality throughout each stage of the product development and production process. Since the focus of QFD is placed on the early stage, the uncertainty in the input information of QFD is inevitable. If the uncertainty is neglected, the QFD analysis results are likely to be misleading. This paper classifies the sources of uncertainty in QFD, and proposes a new approach to model and analyze the effects of uncertainty in QFD.

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UNCERTAINTY IN DAM BREACH FLOOD ROUTING RESULTS FOR DAM SAFETY RISK ASSESSMENT

  • Lee, Jong-Seok
    • Water Engineering Research
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    • 제3권4호
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    • pp.215-234
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    • 2002
  • Uncertainty in dam breach flood routing results was analyzed in order to provide the basis fer the investigation of their effects on the flood damage assessments and dam safety risk assessments. The Monte Carlo simulation based on Latin Hypercube Sampling technique was used to generate random values for two uncertain input parameters (i.e., dam breach parameters and Manning's n roughness coefficients) of a dam breach flood routing analysis model. The flood routing results without considering the uncertainty in two input parameters were compared with those with considering the uncertainty. This paper showed that dam breach flood routing results heavily depend on the two uncertain input parameters. This study indicated that the flood damage assessments in the downstream areas can be critical if uncertainty in dam breach flood routing results are considered in a reasonable manner.

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구조화된 불확실성을 갖는 전력 계통의 적응 관측기 설계 (Design of Adaptive Observer for Power System with Structured Uncertainty)

  • 황정록;김도우;김홍필;양해원
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 C
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    • pp.1211-1214
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    • 1999
  • Power system operating conditions vary with system configuration and loading conditions. Coefficients in nominal system model change in a complex manner with different operating point and so does system dynamic behavior. With the aid of unstructured and structured uncertainty descriptions the worst system variations can be estimated and formulated into two different uncertainty models multiplicative unstructured uncertainty in the form of transfer function and structured uncertainty with the parametric uncertainty description. in frequency domain

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함정탑재장비 진동 측정불확도 추정 (Estimation of Uncertainty in Vibration Measurement of Shipboard Equipment)

  • 박성호;이경현;한형석
    • 한국소음진동공학회논문집
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    • 제24권7호
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    • pp.509-516
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    • 2014
  • This paper proposes estimation model of uncertainty in vibration measurement of shipboard equipment and analyzes the result of uncertainty estimation. Vibration of shipboard equipments affects underwater radiated noise that is important performance related to stealth of the naval vessel. Acceptance testing for shipboard equipment is required to guarantee the stealth performance of naval vessel. In measuring, detailed uncertainty estimation is essential to improve measuring reliability. Acceptance testing result of structure-borne noise and vibration is used to analyze uncertainty in vibration measurement of shipboard equipment.

Dynamic Relationship between Stock Prices and Exchange Rates: Evidence from Nepal

  • Kim, Do-Hyun;Subedi, Shyam;Chung, Sang-Kuck
    • 국제지역연구
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    • 제20권3호
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    • pp.123-144
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    • 2016
  • This paper investigates the linkages between returns both in foreign exchange and stock markets, and uncertainties in two markets using daily data for the period of 16 July 2004 to 30 June 2014 in Nepalese economy. Four hypotheses are tested about how uncertainty influences the stock index and exchange rates. From the empirical results, a bivariate EGARCH-M model is the best to explain the volatility in the two markets. There is a negative relationship from the exchange rates return to stock price return. Empirical results do provide strong empirical confirmation that negative effect of stock index uncertainty and positive effect of exchange rates uncertainty on average stock index. GARCH-in-mean variables in AR modeling are significant and shows that there is positive effect of exchange rates uncertainty and negative effect of stock index uncertainty on average exchange rates. Stock index shocks have longer lived effects on uncertainty in the stock market than exchange rates shock have on uncertainly in the foreign exchange market. The effect of the last period's shock, volatility is more sensitive to its own lagged values.

Sparsity Increases Uncertainty Estimation in Deep Ensemble

  • Dorjsembe, Uyanga;Lee, Ju Hong;Choi, Bumghi;Song, Jae Won
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2021년도 춘계학술발표대회
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    • pp.373-376
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    • 2021
  • Deep neural networks have achieved almost human-level results in various tasks and have become popular in the broad artificial intelligence domains. Uncertainty estimation is an on-demand task caused by the black-box point estimation behavior of deep learning. The deep ensemble provides increased accuracy and estimated uncertainty; however, linearly increasing the size makes the deep ensemble unfeasible for memory-intensive tasks. To address this problem, we used model pruning and quantization with a deep ensemble and analyzed the effect in the context of uncertainty metrics. We empirically showed that the ensemble members' disagreement increases with pruning, making models sparser by zeroing irrelevant parameters. Increased disagreement implies increased uncertainty, which helps in making more robust predictions. Accordingly, an energy-efficient compressed deep ensemble is appropriate for memory-intensive and uncertainty-aware tasks.

돼지고기 중 플루벤다졸 잔류분석의 불확도 추정 (Estimation of uncertainty for the determination of residual flubendazole in pork)

  • 김미경;박수정;임채미;조병훈;권현정;김동규;정갑수
    • 대한수의학회지
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    • 제47권2호
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    • pp.139-145
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    • 2007
  • Measurement uncertainty could play an important role in the assessment of test results in laboratories and industries. We investigated measurement uncertainties possibly included in determination of flubendazole, a benzimidazole anthelmintic, in pork by HPLC. The concentration of flubendazole was 62.69 ng/g in a sample of pork. Uncertainty was estimated in the analytical procedure of flubendazole. A model equation was made for determination of flubendazole in pork. The four uncertainty components such as weight of sample, volume of sample, calibration curve, and recovery were selected to estimate measurement uncertainties. Standard uncertainty was calculated for each component and all the standard uncertainties were combined. The combined standard uncertainty was expanded to a sample population as an expanded uncertainty. The expanded uncertainty was calculated using k value on Student's t-table and effective degrees of freedom from Welch-Satterthwaite formula. The expanded uncertainty was calculated as 3.45 with the combined standard uncertainty, 1.584 6 and the k value, 2.18. The final expression can be ($62.69{\pm}3.45$) ng/g (confidence level 95%, k = 2.18). The uncertainty value might be estimated differently depending on the selection of the uncertainty components. It is difficult to estimate all the uncertainty factors. Therefore, it is better to take several big effecting components instead of many small effecting components.

Fixed Charge Transportation Problem and Its Uncertain Programming Model

  • Sheng, Yuhong;Yao, Kai
    • Industrial Engineering and Management Systems
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    • 제11권2호
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    • pp.183-187
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    • 2012
  • In this paper, we study the fixed charge transportation problem with uncertain variables. The fixed charge transportation problem has two kinds of costs: direct cost and fixed charge. The direct cost is the cost associated with each source-destination pair, and the fixed charge occurs when the transportation activity takes place in the corresponding source-destination pair. The uncertain fixed charge transportation problem is modeled on the basis of uncertainty theory. According to inverse uncertainty distribution, the model can be transformed into a deterministic form. Finally, in order to solve the uncertain fixed charge transportation problem, a numerical example is given to show the application of the model and algorithm.