• Title/Summary/Keyword: Conditional Probability

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Conditional Probability Based Early Termination of Recursive Coding Unit Structures in HEVC (HEVC의 재귀적 CU 구조에 대한 조건부 확률 기반 고속 탐색 알고리즘)

  • Han, Woo-Jin
    • Journal of Broadcast Engineering
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    • v.17 no.2
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    • pp.354-362
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    • 2012
  • Recently, High Efficiency Video Coding (HEVC) is under development jointly by MPEG and ITU-T for the next international video coding standard. Compared to the previous standards, HEVC supports variety of splitting units, such as coding unit (CU), prediction unit (PU), and transform unit (TU). Among them, it has been known that the recursive quadtree structure of CU can improve the coding efficiency while the encoding complexity is increased significantly. In this paper, a simple conditional probability to predict the early termination condition of recursive unit structure is introduced. The proposed conditional probability is estimated based on Bayes' formula from local statistics of rate-distortion costs in encoder. Experimental results show that the proposed method can reduce the total encoding time by about 32% according to the test configuration while the coding efficiency loss is 0.4%-0.5%. In addition, the encoding time can be reduced by 50% with 0.9% coding efficiency loss when the proposed method was used jointly with HM4.0 early CU termination algorithm.

Statistical analysis and its application of bicycle accidents (자전거 교통사고의 통계분석 및 활용)

  • Hong, Chong-Sun;Kim, Moung-Jin
    • Journal of the Korean Data and Information Science Society
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    • v.21 no.6
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    • pp.1081-1090
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    • 2010
  • Most nations including Korean government make a great endeavor to realize low-carbon and green-growth world. We also work hard to expand bicycle facilities and bicycle road in order to increase bicycle transportation rate. Nowadays number of cyclists is increasing but fortunately, bicycle accidents also increase rapidly. Most data of bicycle accidents published by National Police Agency annually are represented as frequencies in two dimensional contingency tables. In this work, risk rates and characteristics of bicycle accidents are analyzed by using concepts of the probability and conditional probability. Especially with numbers of estimated cyclists and registered cars, risk rates of various kinds of bicycle accidents are obtained. Under the assumption of the conditional independence, probability of bicycle accident occurred at realistic situations could be estimated. Furthermore we discuss to reduce bicycle accidents with these results obtained in this work.

Virtual Machine Provisioning Scheduling with Conditional Probability Inference for Transport Information Service in Cloud Environment (클라우드 환경의 교통정보 서비스를 위한 조건부 확률 추론을 이용한 가상 머신 프로비저닝 스케줄링)

  • Kim, Jae-Kwon;Lee, Jong-Sik
    • Journal of the Korea Society for Simulation
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    • v.20 no.4
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    • pp.139-147
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    • 2011
  • There is a growing tendency toward a vehicle demand and a utilization of traffic information systems. Due to various kinds of traffic information systems and increasing of communication data, the traffic information service requires a very high IT infrastructure. A cloud computing environment is an essential approach for reducing a IT infrastructure cost. And the traffic information service needs a provisioning scheduling method for managing a resource. So we propose a provisioning scheduling with conditional probability inference (PSCPI) for the traffic information service on cloud environment. PSCPI uses a naive bayse inference technique based on a status of a virtual machine. And PSCPI allocates a job to the virtual machines on the basis of an availability of each virtual machine. Naive bayse based PSCPI provides a high throughput and an high availability of virtual machines for real-time traffic information services.

Development of Context Awareness and Service Reasoning Technique for Handicapped People (장애인을 위한 상황인식 및 서비스 추론기술 개발)

  • Ko, Kwang-Eun;Shin, Dong-Jun;Sim, Kwee-Bo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.18 no.4
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    • pp.512-517
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    • 2008
  • It is show that increasing of aged and handicapped people requires development of Ubiquitous computing technique to offer the specialized service for handicapped-people. For this, we need a development of Context Awareness and Service Reasoning Technique that the technique is supplied interaction between user and U-environment instead of the old unilateral relation. The old research of context awareness needed probabilistic presentation model like a Bayesian Network based on expert Systems for recognize given circumstance by a domain of uncertain real world. In this article, we define a domain of disorder activity assistant service application and context model based on ontology in diversified environment and minimized intervention of user and developer. By use this context model, we apply the structure learning of Bayesian Network and decide the service and activity to development of application service for handicapped people. Finally, we define the proper Conditional Probability Table of the structured Bayesian Network and if random situation is given to user, then present state variable of Activity and Service by given Causal relation of Bayesian Network based on Conditional Probability Table and it can be result of context awareness.

Improved Global-Soft Decision Incorporating Second-Order Conditional MAP for Speech Enhancement (음성향상을 위한 2차 조건 사후 최대 확률기법 기반 Global Soft Decision)

  • Kum, Jong-Mo;Chang, Joon-Hyuk
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.6C
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    • pp.588-592
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    • 2009
  • In this paper, we propose a novel method to improve the performance of the global soft decision which is based on the second-order conditional maximum a posteriori (CMAP). Conventional global soft decision scheme has an disadvantage in that the speech absence probability adjusted by a fixed-parameter was sensitive to the various noise environments. In proposed approach using the second-order CMAP, speech absence probability value is more flexible which exploit not only the current observation but also the speech activity decisions in the previous two frames. Experimental results show that the proposed improved global soft decision method based on second-order conditional MAP yields better results compared to the conventional global soft decision technique with the performance criteria of the ITU-T P. 862 perceptual evaluation of speech quality (PESQ).

Speech Enhancement based on Minima Controlled Recursive Averaging Technique Incorporating Second-order Conditional Maximum a posteriori Criterion (2차 조건 사후 최대 확률 기반 최소값 제어 재귀평균기법을 이용한 음성향상)

  • Kum, Jong-Mo;Chang, Joon-Hyuk
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.46 no.4
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    • pp.132-138
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    • 2009
  • In this paper, we propose a novel approach to improve the performance of minima controlled recursive averaging (MCRA) which is based on the second-order conditional maximum a posteriori (CMAP). From an investigation of the MCRA scheme, it is discovered that the MCRA method cannot take full consideration of the inter-frame correlation of voice activity since the noise power estimate is adjusted by the speech presence probability depending on an observation of the current frame. To avoid this phenomenon, the proposed MCRA approach incorporates the second-order CMAP criterion in which the noise power estimate is obtained using the speech presence probability conditioned on both the current observation and the speech activity decisions in the previous two frames. Experimental results show that the proposed MCRA technique based on second-order conditional MAP yields better results compared to the conventional MCRA method.

Agency Problems in Banks and the Efficiency of Restructuring Distressed Firms (은행의 대리문제와 부실기업에의 출자전환)

  • Lee, Sang-Woo;Park, Rae-Soo
    • The Korean Journal of Financial Management
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    • v.24 no.2
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    • pp.113-145
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    • 2007
  • In this paper, we examine whether the poor performance of distressed firms where banks take equity may occur due to agency problems in banks. By adopting the debt-equity swap, the bank can effectively postpone the occurrence of bad loans form the failure of the distressed firm. As a result, firms with more debt will be more likely to obtain debt-equity swap, regardless of their probabilities of revival. This is not because they are more profitable, but because they have more debt and thus it poses greater risk to the bank. We empirically look into these predictions with the data of 44 workout firms and find the following results. First, debt-equity swap appears to be more applicable especially when the distressed firms are large and when BIS of related banks is low. Specifically, the conditional probability of 'large firms' based on debt-equity swap is 65.52% and the conditional probability of 'bad banks' based on debt-equity swap is 75.86%. Also, as predicted, the performance of these debt-equity firms is poorer than that of non debt-equity firms. The conditional probability of 'large firms' based on posterior failure is 84.62% and the conditional probability of 'bad banks' based on posterior failure is 84.62%. This is consistent with our predictions and is also confirmed through results of the logit regression analysis. Second, when the restructuring is led by 'good banks', the performance of equity-swap firms is superior to that of non equity-swap firms. This result is consistent with that of James(1995). Hence, we can conclude that there may be some agency problems in restructuring distressed firm-especially when distressed firms are large and banks are bad. And these agency problems can reconcile the difference between James' results and Park, Lee, and Jang's.

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A Study on Drought Trend in Han River Basin (한강유역의 가뭄경향에 관한 연구)

  • Kim, Hyeong-Su;Mun, Jang-Won;Kim, Jae-Hyeong;Kim, Jung-Hun
    • Journal of Korea Water Resources Association
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    • v.33 no.4
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    • pp.437-446
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    • 2000
  • THe drought analysis is performed by applications of truncation level method and conditional probability concept for hydrologic time series in Han river basin. The distributed trend of conditional probability is determined using kriging method for the time series. This study uses daily flowrate, monthly rainfall, and daily high temperature data sets. The daily flowrate data of 12 years(1986~1997) is used for the analysis. Also, the 14 years' data sets(1986~1999) for monthly rainfall and daily high temperature obtained from the National Weather Service of Korea are used in this study. In the cases of flowrate and rainfall data sets, the estimated value corresponding to the truncation level is decreased as the truncation level is increased but in the high temperature data, the value is increased as the truncation level is increased. The conditional probability varies according to the observations and sites. However, the distributed trend of drought is similar over the basin. As a result, the possibility of the drought is high in the middle and lower parts of Han river basin and thus it is recommended the distributed trend of drought be considered when the plan or measures for drought are established.

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A Study on Methodology for Improving Demand Forecasting Models in the Designated Driver Service Market (대리운전 시장의 지역별 수요 예측 모형의 성능 향상을 위한 방법론 연구)

  • Min-Seop Kim;Ki-Kun Park;Jae-Hyeon Heo;Jae-Eun Kwon;Hye-Rim Bae
    • The Journal of Bigdata
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    • v.8 no.1
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    • pp.23-34
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    • 2023
  • Nowadays, the Designated Driver Services employ dynamic pricing, which adapts in real-time based on nearby driver availability, service user volume, and current weather conditions during the user's request. The uncertain volatility is the main cause of price increases, leading to customer attrition and service refusal from driver. To make a good Designated Driver Services, development of a demand forecasting model is required. In this study, we propose developing a demand forecasting model using data from the Designated Driver Service by considering normal and peak periods, such as rush hour and rush day, as prior knowledge to enhance the model performance. We propose a new methodology called Time-Series with Conditional Probability(TSCP), which combines conditional probability and time-series models to enhance performance. Extensive experiments have been conducted with real Designated Driver Service data, and the result demonstrated that our method outperforms the existing time-series models such as SARIMA, Prophet. Therefore, our study can be considered for decision-making to facilitate proactive response in Designated Driver Services.

VUS and HUM Represented with Mann-Whitney Statistic

  • Hong, Chong Sun;Cho, Min Ho
    • Communications for Statistical Applications and Methods
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    • v.22 no.3
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    • pp.223-232
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    • 2015
  • The area under the ROC curve (AUC), the volume under the ROC surface (VUS) and the hypervolume under the ROC manifold (HUM) are defined and interpreted with probability that measures the discriminant power of classification models. AUC, VUS and HUM are expressed with the summation and integration notations for discrete and continuous random variables, respectively. AUC for discrete two random samples is represented as the nonparametric Mann-Whitney statistic. In this work, we define conditional Mann-Whitney statistics to compare more than two discrete random samples as well as propose that VUS and HUM are represented as functions of the conditional Mann-Whitney statistics. Three and four discrete random samples with some tie values are generated. Values of VUS and HUM are obtained using the proposed statistic. The values of VUS and HUM are identical with those obtained by definition; therefore, both VUS and HUM could be represented with conditional Mann-Whitney statistics proposed in this paper.