• 제목/요약/키워드: Sequential context

검색결과 69건 처리시간 0.021초

보다 정확한 동적 상황인식 추천을 위해 정확 및 오류 패턴을 활용하여 순차적 매칭 성능이 개선된 상황 예측 방법 (Context Prediction Using Right and Wrong Patterns to Improve Sequential Matching Performance for More Accurate Dynamic Context-Aware Recommendation)

  • 권오병
    • Asia pacific journal of information systems
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    • 제19권3호
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    • pp.51-67
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    • 2009
  • Developing an agile recommender system for nomadic users has been regarded as a promising application in mobile and ubiquitous settings. To increase the quality of personalized recommendation in terms of accuracy and elapsed time, estimating future context of the user in a correct way is highly crucial. Traditionally, time series analysis and Makovian process have been adopted for such forecasting. However, these methods are not adequate in predicting context data, only because most of context data are represented as nominal scale. To resolve these limitations, the alignment-prediction algorithm has been suggested for context prediction, especially for future context from the low-level context. Recently, an ontological approach has been proposed for guided context prediction without context history. However, due to variety of context information, acquiring sufficient context prediction knowledge a priori is not easy in most of service domains. Hence, the purpose of this paper is to propose a novel context prediction methodology, which does not require a priori knowledge, and to increase accuracy and decrease elapsed time for service response. To do so, we have newly developed pattern-based context prediction approach. First of ail, a set of individual rules is derived from each context attribute using context history. Then a pattern consisted of results from reasoning individual rules, is developed for pattern learning. If at least one context property matches, say R, then regard the pattern as right. If the pattern is new, add right pattern, set the value of mismatched properties = 0, freq = 1 and w(R, 1). Otherwise, increase the frequency of the matched right pattern by 1 and then set w(R,freq). After finishing training, if the frequency is greater than a threshold value, then save the right pattern in knowledge base. On the other hand, if at least one context property matches, say W, then regard the pattern as wrong. If the pattern is new, modify the result into wrong answer, add right pattern, and set frequency to 1 and w(W, 1). Or, increase the matched wrong pattern's frequency by 1 and then set w(W, freq). After finishing training, if the frequency value is greater than a threshold level, then save the wrong pattern on the knowledge basis. Then, context prediction is performed with combinatorial rules as follows: first, identify current context. Second, find matched patterns from right patterns. If there is no pattern matched, then find a matching pattern from wrong patterns. If a matching pattern is not found, then choose one context property whose predictability is higher than that of any other properties. To show the feasibility of the methodology proposed in this paper, we collected actual context history from the travelers who had visited the largest amusement park in Korea. As a result, 400 context records were collected in 2009. Then we randomly selected 70% of the records as training data. The rest were selected as testing data. To examine the performance of the methodology, prediction accuracy and elapsed time were chosen as measures. We compared the performance with case-based reasoning and voting methods. Through a simulation test, we conclude that our methodology is clearly better than CBR and voting methods in terms of accuracy and elapsed time. This shows that the methodology is relatively valid and scalable. As a second round of the experiment, we compared a full model to a partial model. A full model indicates that right and wrong patterns are used for reasoning the future context. On the other hand, a partial model means that the reasoning is performed only with right patterns, which is generally adopted in the legacy alignment-prediction method. It turned out that a full model is better than a partial model in terms of the accuracy while partial model is better when considering elapsed time. As a last experiment, we took into our consideration potential privacy problems that might arise among the users. To mediate such concern, we excluded such context properties as date of tour and user profiles such as gender and age. The outcome shows that preserving privacy is endurable. Contributions of this paper are as follows: First, academically, we have improved sequential matching methods to predict accuracy and service time by considering individual rules of each context property and learning from wrong patterns. Second, the proposed method is found to be quite effective for privacy preserving applications, which are frequently required by B2C context-aware services; the privacy preserving system applying the proposed method successfully can also decrease elapsed time. Hence, the method is very practical in establishing privacy preserving context-aware services. Our future research issues taking into account some limitations in this paper can be summarized as follows. First, user acceptance or usability will be tested with actual users in order to prove the value of the prototype system. Second, we will apply the proposed method to more general application domains as this paper focused on tourism in amusement park.

CRFNet: Context ReFinement Network used for semantic segmentation

  • Taeghyun An;Jungyu Kang;Dooseop Choi;Kyoung-Wook Min
    • ETRI Journal
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    • 제45권5호
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    • pp.822-835
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    • 2023
  • Recent semantic segmentation frameworks usually combine low-level and high-level context information to achieve improved performance. In addition, postlevel context information is also considered. In this study, we present a Context ReFinement Network (CRFNet) and its training method to improve the semantic predictions of segmentation models of the encoder-decoder structure. Our study is based on postprocessing, which directly considers the relationship between spatially neighboring pixels of a label map, such as Markov and conditional random fields. CRFNet comprises two modules: a refiner and a combiner that, respectively, refine the context information from the output features of the conventional semantic segmentation network model and combine the refined features with the intermediate features from the decoding process of the segmentation model to produce the final output. To train CRFNet to refine the semantic predictions more accurately, we proposed a sequential training scheme. Using various backbone networks (ENet, ERFNet, and HyperSeg), we extensively evaluated our model on three large-scale, real-world datasets to demonstrate the effectiveness of our approach.

전시공간의 표현요소 연구 (A Study on the Expressive Factors of Exhibition Space)

  • 김준호
    • 한국디자인학회:학술대회논문집
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    • 한국디자인학회 2000년도 추계 학술발표대회 논문집
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    • pp.46-47
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    • 2000
  • 전시공간에는 공간성과 시간성이 교차한다. 구조화된 공간은 시간적 인식 매커니즘으로 개별 시퀀스의 맥락적 합으로 인식된다. 그것은 마치 한편의 영화를 감상할 때나 전통 중국음식을 음미할 때에 잔상, 잔미의 연속적 롤 플레잉의 과정과 유사하다. (중략)

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모바일 환경을 위한 멀티모달 미들웨어의 설계 및 구현 (Design and Implementation of Multimodal Middleware for Mobile Environments)

  • 박성수;안세열;김원우;구명완;박성찬
    • 대한음성학회지:말소리
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    • 제60호
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    • pp.125-144
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    • 2006
  • W3C announced a standard software architecture for multimodal context-aware middleware that emphasizes modularity and separates structure, contents, and presentation. We implemented a distributed multimodal interface system followed the W3C architecture, based on SCXML. SCXML uses parallel states to invoke both XHTML and VoiceXML contents as well as to gather composite or sequential multimodal inputs through man-machine interactions. We also hire Delivery Context Interface(DCI) module and an external service bundle enabling middleware to support context-awareness services for real world environments. The provision of personalized user interfaces for mobile devices is expected to be used for different devices with a wide variety of capabilities and interaction modalities. We demonstrated the implemented middleware could maintain multimodal scenarios in a clear, concise and consistent manner by some experiments.

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상황 추론을 위한 Fuzzy Colored Timed Petri Net (Fuzzy Colored Timed Petri Nets for Context Inference)

  • 이건명;이경미;황경순
    • 한국지능시스템학회논문지
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    • 제16권3호
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    • pp.291-296
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    • 2006
  • 상황은 단일 사건에 의해 결정되는 경우도 있지만, 많은 경우 일련의 사건이 특정 시간 제약을 만족하면서 발생할 때 상황이 결정된다. 따라서 상황에 대한 추론은 시간 제약 조건 만족 여부와 함께 사건의 발생을 순서를 확인하는 방법으로 수행될 수 있다. 한편, 어떤 상황은 분명하게 정의되는 것이 아니라 애매한 개념을 사용하여 기술되기 때문에, 퍼지 개념을 이용한 상황 기술과 이에 대한 추론이 필요하다. 한편, 유비쿼터스 환경에서와 같이 여러 대상에 대한 상황을 유추하여 서비스를 제공해야 하는 경우에, 대상 간에 동일한 상황이 발생할 수 있기 때문에 이에 대한 고려가 필요하다. 이러한 상황 추론을 위해서 이 논문에서는 Fuzzy Colored Timed Petri net 모델이라는 상황 추론 모델에 대해서 제안한다. 제안한 모델은 Timed Petri net 성질을 이용하여 일련의 사건 발생을 모델링하고, Colored Petri net의 성질을 이용하여 다수 대상에 대한 상황 추론을 허용하며, fuzzy 토큰 개념을 이용하여 애매한 개념을 사용하여 정의된 상환에 대한 추론을 가능하게 한다.

순차적 시뮬레이션을 위한 순차적인 Percentile 추정에 관한 연구 (Sequential Percentile Estimation for Sequential Steady-State Simulation)

  • 이종숙;정해덕
    • 정보처리학회논문지D
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    • 제10D권6호
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    • pp.1025-1032
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    • 2003
  • 백분위수는 시뮬레이션 결과의 전체적인 성향을 파악하는데 아주 유용한 측정 기법 중의 하나이다. 그러나, 시뮬레이션으로 수집된 데이터들에 대한 평균이나 표준편차와는 달리 백분위수를 추정하기 위해서는 모든 관측된 데이터들을 저장해야 만 한다, 왜냐하면 백분위수의 추정을 위해서는 관측된 모든 데이를 분류하여 오른차순으로 정렬하는 등 여러 단계의 처리과정이 필요하기 때문이다. 따라서, 백분위수 추정을 위해서는 관측된 모든 데이터를 저장하기 위한 대용량의 저장장치와 정렬을 위한 계산시간 (O($nlog_{2}n$))이 요구된다. 이러한 문제점을 해결하기 위한 여러 백분위수 추정 기법들이 제안되었으나 고정된 샘플 크기의 시뮬레이선(fixed sample size simulation) 을 수행할 경우에만 적용 가능하다. [11, 12, 21]. 본 논문에서는 3가지 백분위수 추정 기법(linear PE, batching PE, spectral $P^2$ PE) 을 순차적인 안정상태 시뮬레이션(sequential steady-state simulation) 에 적용하여 연구하였다. 또한, 3가지의 백분위수 추정 기법들에 대해 coverage 분석을 수행한 결과를 제시하였다.

효율적인 웹기반 교육을 위한 네비게이션 화면의 설계 기법 (A Study on Design Methods of Navigational Interfaces for Effective WWW-Based Instruction)

  • 전명진;박판우
    • 정보교육학회논문지
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    • 제4권2호
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    • pp.212-222
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    • 2001
  • 본 논문에서는 교육용 웹 기반 멀티미디어 코스웨어를 구축할 때 고려해야 하는 네비게이션 화면의 설계 방법에 관하여 연구하였다. 코스웨어를 구성하는 정보구조와 각 구조에 적합한 구체적 탐색 기법에 관해 분석하였으며, 이를 바탕으로 효율적인 초등학생용 웹 기반 멀티미디어 코스웨어를 위한 네비게이션 화면의 설계 방법으로 메뉴-연속 조합형 방법을 제안하였다. 그리고, 제안된 화면 설계방법에 따른 구체적인 코스웨어를 구현하여 현장에 적용 분석하였다.

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대형 설계 시스템의 효율적 반응표면 근사화를 위한 점진적 이차 근사화 기법 (Progressive Quadratic Approximation Method for Effective Constructing the Second-Order Response Surface Models in the Large Scaled System Design)

  • 홍경진;김민수;최동훈
    • 대한기계학회논문집A
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    • 제24권12호
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    • pp.3040-3052
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    • 2000
  • For effective construction of second-order response surface models, an efficient quad ratic approximation method is proposed in the context of trust region model management strategy. In the proposed method, although only the linear and quadratic terms are uniquely determined using 2n+1 design points, the two-factor interaction terms are mathematically updated by normalized quasi-Newton formula. In order to show the numerical performance of the proposed approximation method, a sequential approximate optimizer is developed and solves a typical unconstrained optimization problem having 2, 6, 10, 15, 30 and 50 design variables, a gear reducer system design problem and two dynamic response optimization problems with multiple objectives, five objectives for one and two objectives for the other. Finally, their optimization results are compared with those of the CCD or the 50% over-determined D-optimal design combined with the same trust region sequential approximate optimizer. These comparisons show that the proposed method gives more efficient than others.

User Intention-Awareness System for Goal-oriented Context-Awareness Service

  • Lee, Jung-Eun;Yoon, Tae-Bok;Lee, Jee-Hyong
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제7권2호
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    • pp.154-158
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    • 2007
  • As the technology developed, the system is being developed as the structure that is adapted to the intelligent environment. Therefore, the existing situation information system couldn't provide satisfactory service to the user as it provides service only by the information which it received from the sensor. This paper analyzed the problems of the existing user intention awareness system and suggested user intention awareness system to provide a stable and efficient service that fits to the intention of the user compensating this. This paper has collected the behavior data based on the scenario of the sequential behavior course of the user that occurs at breakfast time in the kitchen which is the home domain environment thai is closely related to our lives. This scenario course also showed the flow that the goal intentional user intention awareness system acted that it suggested, and showed the sequential course processing the user behavior data by tables and charts.

An Integrated Sequential Inference Approach for the Normal Mean

  • Almahmeed, M.A.;Hamdy, H.I.;Alzalzalah, Y.H.;Son, M.S.
    • Journal of the Korean Statistical Society
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    • 제31권4호
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    • pp.415-431
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    • 2002
  • A unified framework for statistical inference for the mean of the normal distribution to derive point estimates, confidence intervals and statistical tests is proposed. This optimal design is justified after investigating the basic information and requirements that are possible and impossible to control when specifying practical and statistical requirements. Point estimation is only credible when viewed in the larger context of interval estimation, since the information required for optimal point estimation is unspecifiable. Triple sampling is proposed and justified as a reasonable sampling vehicle to achieve the specifiable requirements within the unified framework.