• Title/Summary/Keyword: inference model

Search Result 1,171, Processing Time 0.03 seconds

Air Threat Evaluation System using Fuzzy-Bayesian Network based on Information Fusion (정보 융합 기반 퍼지-베이지안 네트워크 공중 위협평가 방법)

  • Yun, Jongmin;Choi, Bomin;Han, Myung-Mook;Kim, Su-Hyun
    • Journal of Internet Computing and Services
    • /
    • v.13 no.5
    • /
    • pp.21-31
    • /
    • 2012
  • Threat Evaluation(TE) which has air intelligence attained by identifying friend or foe evaluates the target's threat degree, so it provides information to Weapon Assignment(WA) step. Most of TE data are passed by sensor measured values, but existing techniques(fuzzy, bayesian network, and so on) have many weaknesses that erroneous linkages and missing data may fall into confusion in decision making. Therefore we need to efficient Threat Evaluation system that can refine various sensor data's linkages and calculate reliable threat values under unpredictable war situations. In this paper, we suggest new threat evaluation system based on information fusion JDL model, and it is principle that combine fuzzy which is favorable to refine ambiguous relationships with bayesian network useful to inference battled situation having insufficient evidence and to use learning algorithm. Finally, the system's performance by getting threat evaluation on an air defense scenario is presented.

The National Forest Inventory of the United States of America

  • McRoberts, Ronald E.
    • Journal of Forest and Environmental Science
    • /
    • v.24 no.3
    • /
    • pp.127-135
    • /
    • 2008
  • The mission of the Forest Inventory and Analyis (FIA) program of the Forest Service, U.S. Department of Agriculture, is to conduct the national forest inventory of the United States of America for purposes of estimating the area of forest land; the volume, growth, and removal of forest resources; and the health of the forest. Users of FIA data, estimates, and related products include land managers, policy and decision-makers, forest industry, environmental organizations, and university researchers. To accomplish its mission, the FIA program has established a sampling design with an intensity of approximately one permanent plot per 2,400 ha across the entire country. Depending on the region of the country, each plot is remeasured at intervals of five or 10 years. The program releases data annually and reports estimates at the county level for each state every five years. Due to budgetary constraints and natural variability among plot observations, sufficient numbers of plots cannot be measured to satisfy precision guidelines for the estimates of many variables unless the estimation process is enhanced using ancillary data. Classified satellite imagery has been demonstrated to be a source of ancillary data that can be used with stratified estimation techniques to increase the precision of estimates with little corresponding increase in costs. A crucial factor restricting the utility of FIA data is that the exact locations of inventory plots cannot be released to the public. Thus, users are generally not able to obtain estimates for small areas or for their own areas of interest if exact plot locations are required. To compensate, satellite imagery, inventory plot data, and the k-Nearest Neighbors technique are being used to construct Internet-based maps of forest attributes from which estimates for arbitrary user-defined areas of interest may be obtained.

  • PDF

On the prediction of unconfined compressive strength of silty soil stabilized with bottom ash, jute and steel fibers via artificial intelligence

  • Gullu, Hamza;Fedakar, Halil ibrahim
    • Geomechanics and Engineering
    • /
    • v.12 no.3
    • /
    • pp.441-464
    • /
    • 2017
  • The determination of the mixture parameters of stabilization has become a great concern in geotechnical applications. This paper presents an effort about the application of artificial intelligence (AI) techniques including radial basis neural network (RBNN), multi-layer perceptrons (MLP), generalized regression neural network (GRNN) and adaptive neuro-fuzzy inference system (ANFIS) in order to predict the unconfined compressive strength (UCS) of silty soil stabilized with bottom ash (BA), jute fiber (JF) and steel fiber (SF) under different freeze-thaw cycles (FTC). The dosages of the stabilizers and number of freeze-thaw cycles were employed as input (predictor) variables and the UCS values as output variable. For understanding the dominant parameter of the predictor variables on the UCS of stabilized soil, a sensitivity analysis has also been performed. The performance measures of root mean square error (RMSE), mean absolute error (MAE) and determination coefficient ($R^2$) were used for the evaluations of the prediction accuracy and applicability of the employed models. The results indicate that the predictions due to all AI techniques employed are significantly correlated with the measured UCS ($p{\leq}0.05$). They also perform better predictions than nonlinear regression (NLR) in terms of the performance measures. It is found from the model performances that RBNN approach within AI techniques yields the highest satisfactory results (RMSE = 55.4 kPa, MAE = 45.1 kPa, and $R^2=0.988$). The sensitivity analysis demonstrates that the JF inclusion within the input predictors is the most effective parameter on the UCS responses, followed by FTC.

Foreign Direct Investment and Economic Growth: A Cross-Country Analysis (외국인 직접투자와 경제성장에 대한 다국가 분석)

  • Jeong, Dong-Won;Jeong, Kyong-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.18 no.10
    • /
    • pp.588-596
    • /
    • 2017
  • Although many policy makers and scholars argue that foreign direct investment is crucial to the economic growth of developing countries, there is no universal agreement on the positive relationship between foreign direct investment inflows and economic growth. Using a cross-country analysis based on data from 88 countries for the years 1990-2015, this paper empirically explores the impact of FDI on economic growth. To this end, several versions of the neoclassical growth models, explicitly including FDI, are estimated. Subject to the appropriate caveats, the results provide further support for several key conclusions of former studies, including the inference that investment in physical capital, population growth, and human capital are important in accounting for economic growth across countries. The results show that FDI significantly contributes to economic growth in developing countries.

Causal reasoning studies with a focus on the Power Probabilistic Contrast Theory (힘 확률 대비 이론에 기반을 둔 인과 추론 연구)

  • Park, Jooyong
    • Korean Journal of Cognitive Science
    • /
    • v.27 no.4
    • /
    • pp.541-572
    • /
    • 2016
  • Causal reasoning is actively studied not only by psychologists but, in recent years, also by cognitive scientists taking the Bayesian approach. This paper seeks to provide an overview of the recent trends in causal reasoning research with a focus on the power probabilistic contrast theory of causality, a major psychological theory on causal inference. The power probabilistic contrast theory (PPCT) assumes that a cause is a power that initiates or inhibits the result. This power is purported be understood through statistical correlation under certain conditions. The paper examines the supporting empirical evidence in the development of PPCT. Also, introduced are the theoretical dispute between the PPCT and the model based on Bayesian approach, and the current developments and implications of research on causal invariance hypothesis, which states that cause operates identically regardless of the context. Recent studies have produced experimental results that cannot be readily explained by existing empirical approach. Therefore, these results call for serious examination of the power theory of causality by researchers in neighboring fields such as philosophy, statistics, and artificial intelligence.

Comparative Analysis of Parameter Estimation Methods in Estimation of Spatial Distribution of Probability Rainfall (확률강우량의 공간분포추정에 있어서 매개변수 추정기법의 비교분석)

  • Seo, Young-Min;Yeo, Woon-Ki;Jee, Hong-Kee
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2011.05a
    • /
    • pp.413-413
    • /
    • 2011
  • 강우의 공간분포에 대한 신뢰성 있는 추정은 수자원 해석 및 설계에 있어서 필수적인 요소이다. 강우장의 공간변동성에 대한 고해상도 추정은 홍수, 특히 돌발홍수의 원인이 되는 국지성 호우의 확인 및 분석에 있어서 중요하다. 또한 강우의 공간 변동성에 대한 고려는 면적평균강우량 추정의 정확도를 향상시키는데 있어서 중요하며, 강우-유출모델의 모의결과에 대한 신뢰도를 향상시키는데 큰 영향을 미친다. 최근 공간자료에 대한 공간분포예측에 있어서 공간상관성을 고려할 수 있는 공간통계학적 기법의 적용이 증가하고 있으며, 이러한 공간통계학적 기법의 적용에 있어서 신뢰성 있는 모델 매개변수의 추정 및 불확실성 평가는 공간분포 예측결과에 대한 신뢰성을 향상시키는데 중요한 역할을 한다. 외국의 경우 공간분포예측 및 모의, 매개변수의 불확실성 평가 등과 관련하여 활발한 연구가 이루어지고 있는 반면 국내 수자원 분야에서는 아직까지 활발한 연구가 이루어지고 있지 않은 실정이다. 따라서 본 연구에서는 계층구조로 구성된 가우시안 공간선형혼합모델을 적용하여 확률강우량의 공간분포를 추정함에 있어서 모델 매개변수에 대한 추정기법을 비교하였으며, 매개변수 추정기법으로서 경험베리오그램에 대한 곡선적합기법인 보통최소제곱법 및 가중최소제곱법, 우도함수를 기반으로 하는 최우도법 및 REML과 같은 기존의 매개변수 추정기법들과 최근 공간통계학 분야에서 적용이 증가하고 있는 Bayesian 기법을 비교하였다. 이로부터 매개변수 추정기법 간의 매개변수 추정치에 대한 정량적 비교결과를 제시하였으며, Bayesian 기법의 적용을 통해 매개변수에 대한 불확실성 추정결과를 제시하였다. 이러한 결과들은 확률강우량의 공간분포 추정에 있어서 공간예측모델의 매개변수 추정 및 예측에 대한 신뢰성을 향상시킬 수 있는 기초자료로 활용될 수 있을 것이다.

  • PDF

Embeded-type Search Function with Feedback for Smartphone Applications (스마트폰 애플리케이션을 위한 임베디드형 피드백 지원 검색체)

  • Kang, Moonjoong;Hwang, Mintae
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.21 no.5
    • /
    • pp.974-983
    • /
    • 2017
  • In this paper, we have discussed the search function that can be embedded and used on Android-based applications. We used BM25 to suppress insignificant and too frequent words such as postpositions, Pivoted Length Normalization technique used to resolve the search priority problem related to each item's length, and Rocchio's method to pull items inferred to be related to the query closer to the query vector on Vector Space Model to support implicit feedback function. The index operation is divided into two methods; simple index to support offline operation and complex index for online operation. The implementation uses query inference function to guess user's future input by collating given present input with indexed data and with it the function is able to handle and correct user's error. Thus the implementation could be easily adopted into smartphone applications to improve their search functions.

Covariate selection criteria for controlling confounding bias in a causal study (인과연구에서 중첩편향을 제거하기 위한 공변량선택기준)

  • Thepepomma, Seethad;Kim, Ji-Hyun
    • The Korean Journal of Applied Statistics
    • /
    • v.29 no.5
    • /
    • pp.849-858
    • /
    • 2016
  • It is important to control confounding bias when estimating the causal effect of treatment in an observational study. We illustrated that the covariate selection in the causal inference is different from the variable selection in the ANCOVA model. We then investigated the three criteria of covariate selection for controlling confounding bias, which can be used when we have inadequate information to draw a complete causal graph. VanderWeele and Shpitser (2011) proposed one of them and claimed it was better than the other two. We show by example that their criterion also has limitations and some disadvantages. There is no clear winner; however, their criterion is better (if some correction is made on its condition) than the other two because it can remove the confounding bias.

Development of Water Demand Forecasting Simulator and Performance Evaluation (단기 물 수요예측 시뮬레이터 개발과 예측 알고리즘 성능평가)

  • Shin, Gang-Wook;Kim, Ju-Hwan;Yang, Jae-Rheen;Hong, Sung-Taek
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.25 no.4
    • /
    • pp.581-589
    • /
    • 2011
  • Generally, treated water or raw water is transported into storage reservoirs which are receiving facilities of local governments from multi-regional water supply systems. A water supply control and operation center is operated not only to manage the water facilities more economically and efficiently but also to mitigate the shortage of water resources due to the increase in water consumption. To achieve the goal, important information such as the flow-rate in the systems, water levels of storage reservoirs or tanks, and pump-operation schedule should be considered based on the resonable water demand forecasting. However, it is difficult to acquire the pattern of water demand used in local government, since the operating information is not shared between multi-regional and local water systems. The pattern of water demand is irregular and unpredictable. Also, additional changes such as an abrupt accident and frequent changes of electric power rates could occur. Consequently, it is not easy to forecast accurate water demands. Therefore, it is necessary to introduce a short-term water demands forecasting and to develop an application of the forecasting models. In this study, the forecasting simulator for water demand is developed based on mathematical and neural network methods as linear and non-linear models to implement the optimal water demands forecasting. It is shown that MLP(Multi-Layered Perceptron) and ANFIS(Adaptive Neuro-Fuzzy Inference System) can be applied to obtain better forecasting results in multi-regional water supply systems with a large scale and local water supply systems with small or medium scale than conventional methods, respectively.

Complete Mitochondrial Genome of a Troglobite Millipede Antrokoreana gracilipes (Diplopoda, Juliformia, Julida), and Juliformian Phylogeny

  • Woo, Hyung-Jik;Lee, Yong-Seok;Park, Shin-Ju;Lim, Jong-Tae;Jang, Kuem-Hee;Choi, Eun-Hwa;Choi, Yong-Gun;Hwang, Ui Wook
    • Molecules and Cells
    • /
    • v.23 no.2
    • /
    • pp.182-191
    • /
    • 2007
  • The complete mitochondrial genome of a troglobite millipede Antrokoreana gracilipes (Verhoeff, 1938) (Dipolopoda, Juliformia, Julida) was sequenced and characterized. The genome (14,747 bp) contains 37 genes (2 ribosomal RNA genes, 22 transfer RNA genes and 13 protein-encoding genes) and two large non-coding regions (225 bp and 31 bp), as previously reported for two diplopods, Narceus annularus (order Spirobolida) and Thyropygus sp. (order Spirostreptida). The A + T content of the genome is 62.1%, and four tRNAs ($tRNA^{Ser(AGN)}$, $tRNA^{Cys}$, $tRNA^{Ile}$ and $tRNA^{Met}$) have unusual and unstable secondary structures. Whereas Narceus and Thyropygus have identical gene arrangements, the $tRNA^{Thr}$ and $tRNA^{Trp}$ of Antrokoreana differ from them in their orientations and/or positions. This suggests that the Spirobolida and Spirostreptida are more closely related to each other than to the Dipolopoda. Three scenarios are proposed to account for the unique gene arrangement of Antrokoreana. The data also imply that the Duplication and Nonrandom Loss (DNL) model is applicable to the order Julida. Bayesian inference (BI) and maximum likelihood (ML) analyses using amino acid sequences deduced from the 12 mitochondrial protein-encoding genes (excluding ATP8) support the view that the three juliformian members are monophyletic (BI 100%; ML 100%), that Thyropygus (Spirostreptida) and Narceus (Spirobolida) are clustered together (BI 100%; ML 83%), and that Antrokoreana (Julida) is a sister of the two. However, due to conflict with previous reports using cladistic approaches based on morphological characteristics, further studies are needed to confirm the close relationship between Spirostreptida and Spirobolida.