• Title/Summary/Keyword: sequence-to-sequence 모델

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MCMC Algorithm for Dirichlet Distribution over Gridded Simplex (그리드 단체 위의 디리슐레 분포에서 마르코프 연쇄 몬테 칼로 표집)

  • Sin, Bong-Kee
    • KIISE Transactions on Computing Practices
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    • v.21 no.1
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    • pp.94-99
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    • 2015
  • With the recent machine learning paradigm of using nonparametric Bayesian statistics and statistical inference based on random sampling, the Dirichlet distribution finds many uses in a variety of graphical models. It is a multivariate generalization of the gamma distribution and is defined on a continuous (K-1)-simplex. This paper presents a sampling method for a Dirichlet distribution for the problem of dividing an integer X into a sequence of K integers which sum to X. The target samples in our problem are all positive integer vectors when multiplied by a given X. They must be sampled from the correspondingly gridded simplex. In this paper we develop a Markov Chain Monte Carlo (MCMC) proposal distribution for the neighborhood grid points on the simplex and then present the complete algorithm based on the Metropolis-Hastings algorithm. The proposed algorithm can be used for the Markov model, HMM, and Semi-Markov model for accurate state-duration modeling. It can also be used for the Gamma-Dirichlet HMM to model q the global-local duration distributions.

Virtual Power Plant System using OpenADR2.0 and TASE.2 for Integrated Management of Distributed Energy Resource (분산자원 통합 관리를 위한 OpenADR2.0 및 TASE.2 기반 가상발전소 시스템)

  • Seo, Jong Kwan;Lee, Tae Il;Lee, Whee Sung;Park, Jeom Bae
    • Journal of IKEEE
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    • v.24 no.1
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    • pp.311-318
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    • 2020
  • A virtual power plant is a kind of software power plant that enables participation in power operation by integrally managing individual distributed resources. This paper proposes a common information communication architecture based on the TASE.2 standard and the OpenADR2.0 standard to operate a virtual power plant as a single power system. ESS is designed TASE.2 SBO devices that related objects are mapped to OpenADR2.0 services and composed as a single sequence type. Through simulation verification, it conforms data exchange and operation based on both standards.

New Scheme for Smoker Detection (흡연자 검출을 위한 새로운 방법)

  • Lee, Jong-seok;Lee, Hyun-jae;Lee, Dong-kyu;Oh, Seoung-jun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.9
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    • pp.1120-1131
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    • 2016
  • In this paper, we propose a smoker recognition algorithm, detecting smokers in a video sequence in order to prevent fire accidents. We use description-based method in hierarchical approaches to recognize smoker's activity, the algorithm consists of background subtraction, object detection, event search, event judgement. Background subtraction generates slow-motion and fast-motion foreground image from input image using Gaussian mixture model with two different learning-rate. Then, it extracts object locations in the slow-motion image using chain-rule based contour detection. For each object, face is detected by using Haar-like feature and smoke is detected by reflecting frequency and direction of smoke in fast-motion foreground. Hand movements are detected by motion estimation. The algorithm examines the features in a certain interval and infers that whether the object is a smoker. It robustly can detect a smoker among different objects while achieving real-time performance.

Tweets analysis using a Dynamic Topic Modeling : Focusing on the 2019 Koreas-US DMZ Summit (트윗의 타임 시퀀스를 활용한 DTM 분석 : 2019 남북미정상회동 이벤트를 중심으로)

  • Ko, EunJi;Choi, SunYoung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.25 no.2
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    • pp.308-313
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    • 2021
  • In this study, tweets about the 2019 Koreas-US DMZ Summit were collected along with a time sequence and analyzed by a sequential topic modeling method, Dynamic Topic Modeling(DTM). In microblogging services such as Twitter, unstructured data that mixes news and an opinion about a single event occurs at the same time on a large scale, and information and reactions are produced in the same message format. Therefore, to grasp a topic trend, the contextual meaning can be found only by performing pattern analysis reflecting the characteristics of sequential data. As a result of calculating the DTM after obtaining the topic coherence score and evaluating the Latent Dirichlet Allocation(LDA), 30 topics related to news reports and opinions were derived, and the probability of occurrence of each topic and keywords were dynamically evolving. In conclusion, the study found that DTM is a suitable model for analyzing the trend of integrated topics in a specific event over time.

Analysis of Wave Distribution at Nakdong River Estuary Depending on the Incident Wave Directions Based on SWAN Model Simulation (SWAN 모델을 이용한 낙동강 하구역의 입사파향별 파랑분포 특성)

  • Park, Soon;Yoon, Han-Sam;Park, Hyo-Bong;Ryu, Seung-Woo;Ryu, Cheong-Ro
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.12 no.3
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    • pp.188-196
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    • 2009
  • This study conducted numerical simulations to analyze the wave characteristics(distribution) depending on the directional changes of waves in the Nakdong river estuary by using SWAN(Simulating WAves Nearshore) model. The results from the tests are summarized as below. The wave height rates are generally highly distributed with the incident waves from the S, SSE, SSW, SE, SW in sequence. When the waves from the S, SSW, SSE directions are predominant, the bigger waves were observed in front of sandbars. According to the results of the wave steepness against the wave direction, at the east coast of Gadeok island(northwest of Nakdong estuary), where has mild seabed slopes, the wave height rates distribute in the range of 0.4~0.6; the wave height rates over the west coastal region of Dadeapo(southeast of Nakdong estuary) are 0.5~0.6. The wave height rate tends to be rapidly decreased over the east region of Nakdong river estuary rather than its west region.

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Development of a complex failure prediction system using Hierarchical Attention Network (Hierarchical Attention Network를 이용한 복합 장애 발생 예측 시스템 개발)

  • Park, Youngchan;An, Sangjun;Kim, Mintae;Kim, Wooju
    • Journal of Intelligence and Information Systems
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    • v.26 no.4
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    • pp.127-148
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    • 2020
  • The data center is a physical environment facility for accommodating computer systems and related components, and is an essential foundation technology for next-generation core industries such as big data, smart factories, wearables, and smart homes. In particular, with the growth of cloud computing, the proportional expansion of the data center infrastructure is inevitable. Monitoring the health of these data center facilities is a way to maintain and manage the system and prevent failure. If a failure occurs in some elements of the facility, it may affect not only the relevant equipment but also other connected equipment, and may cause enormous damage. In particular, IT facilities are irregular due to interdependence and it is difficult to know the cause. In the previous study predicting failure in data center, failure was predicted by looking at a single server as a single state without assuming that the devices were mixed. Therefore, in this study, data center failures were classified into failures occurring inside the server (Outage A) and failures occurring outside the server (Outage B), and focused on analyzing complex failures occurring within the server. Server external failures include power, cooling, user errors, etc. Since such failures can be prevented in the early stages of data center facility construction, various solutions are being developed. On the other hand, the cause of the failure occurring in the server is difficult to determine, and adequate prevention has not yet been achieved. In particular, this is the reason why server failures do not occur singularly, cause other server failures, or receive something that causes failures from other servers. In other words, while the existing studies assumed that it was a single server that did not affect the servers and analyzed the failure, in this study, the failure occurred on the assumption that it had an effect between servers. In order to define the complex failure situation in the data center, failure history data for each equipment existing in the data center was used. There are four major failures considered in this study: Network Node Down, Server Down, Windows Activation Services Down, and Database Management System Service Down. The failures that occur for each device are sorted in chronological order, and when a failure occurs in a specific equipment, if a failure occurs in a specific equipment within 5 minutes from the time of occurrence, it is defined that the failure occurs simultaneously. After configuring the sequence for the devices that have failed at the same time, 5 devices that frequently occur simultaneously within the configured sequence were selected, and the case where the selected devices failed at the same time was confirmed through visualization. Since the server resource information collected for failure analysis is in units of time series and has flow, we used Long Short-term Memory (LSTM), a deep learning algorithm that can predict the next state through the previous state. In addition, unlike a single server, the Hierarchical Attention Network deep learning model structure was used in consideration of the fact that the level of multiple failures for each server is different. This algorithm is a method of increasing the prediction accuracy by giving weight to the server as the impact on the failure increases. The study began with defining the type of failure and selecting the analysis target. In the first experiment, the same collected data was assumed as a single server state and a multiple server state, and compared and analyzed. The second experiment improved the prediction accuracy in the case of a complex server by optimizing each server threshold. In the first experiment, which assumed each of a single server and multiple servers, in the case of a single server, it was predicted that three of the five servers did not have a failure even though the actual failure occurred. However, assuming multiple servers, all five servers were predicted to have failed. As a result of the experiment, the hypothesis that there is an effect between servers is proven. As a result of this study, it was confirmed that the prediction performance was superior when the multiple servers were assumed than when the single server was assumed. In particular, applying the Hierarchical Attention Network algorithm, assuming that the effects of each server will be different, played a role in improving the analysis effect. In addition, by applying a different threshold for each server, the prediction accuracy could be improved. This study showed that failures that are difficult to determine the cause can be predicted through historical data, and a model that can predict failures occurring in servers in data centers is presented. It is expected that the occurrence of disability can be prevented in advance using the results of this study.

Adaptive Shot Change Detection Technique Using Mean of Feature Value on Variable Reference Block (가변 참조 구간의 평균 특징값을 이용한 적응적인 장면 전환 검출 기법)

  • Kim, Won-Hee;Moon, Kwang-Seok;Kim, Jong-Nam
    • Journal of the Institute of Convergence Signal Processing
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    • v.9 no.4
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    • pp.272-279
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    • 2008
  • Shot change detection is an important technique for effective management of video data, so detection scheme requires adaptive detection techniques to be used actually in various video. In this paper, we propose an adaptive shot change detection algorithm using the mean of feature value on variable reference blocks. Our algorithm determines shot change detection by defining adaptive threshold values with the feature value extracted from video frames and comparing the feature value and the threshold value. We obtained better detection ratio than the conventional methods maximally by 15% in the experiment with the same test sequence. We also had good detection ratio for other several methods of feature extraction and could see realtime operation of shot change detection in the hardware platform with low performance was possible by implementing it in TVUS model of HOMECAST company. Thus, our algerian in the paper can be useful in PMP(portable multimedia player) or other portable players.

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Feature Extraction and Image Segmentation of Mechanical Structures from Human Medical Images (의료 영상을 이용한 인체 역학적 구조물 특징 추출 및 영상 분할)

  • 호동수;김성현;김도일;서태석;최보영;김의녕;이진희;이형구
    • Progress in Medical Physics
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    • v.15 no.2
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    • pp.112-119
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    • 2004
  • We tried to build human models based on medical images of live Korean, instead of using standard data of human body structures. Characteristics of mechanical structures of human bodies were obtained from medical images such as CT and MR images. For each constitutional part of mechanical structures CT images were analyzed in terms of gray levels and MR images were analyzed in terms of pulse sequence. Characteristic features of various mechanical structures were extracted from the analyses. Based on the characteristics of each structuring element we peformed image segmentation on CT and MR images. We delineated bones, muscles, ligaments and tendons from CT and MR images using image segmentation or manual drawing. For the image segmentation we compared the edge detection method, region growing method and intensity threshold method and applied an optimal compound of these methods for the best segmentation results. Segmented mechanical structures of the head/neck part were three dimensionally reconstructed.

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Thermal Residual Stresses in the Frequency Selective Surface Embedded Composite Structures and Design of Frequency Selective Surface (주파수 선택적 투과막이 결합된 복합재료의 잔류응력평가 및 선택적 투과막 설계)

  • Kim, Ka-Yeon;Chun, Heoung-Jae;Kang, Kyung-Tak;Lee, Kyung-Won;Hong, Ic-Pyo;Lee, Myoung-Keon
    • Composites Research
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    • v.24 no.1
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    • pp.37-44
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    • 2011
  • In this paper, Particle Swarm Optimization(PSO) is applied to the design of the Frequency Selective Surface(FSS) and residual stresses of hybrid radome is predicted. An equivalent circuit model with Square Loops arrays was derived and then PSO was applied for acquiring the optimized geometrical parameters with proper resonant frequency. Residual stresses occur in the FSS embedded composite structures after cocuring and have a great influence on the strength of the FSS embedded composite structures. They also effect transmission quality because of delamination. Therefore, the thermal residual stresses of FSS embedded composite structures were analyzed using finite element analysis with considering the effects of FSS pattern, and composite stacking sequence.

Product Recommendation System on VLDB using k-means Clustering and Sequential Pattern Technique (k-means 클러스터링과 순차 패턴 기법을 이용한 VLDB 기반의 상품 추천시스템)

  • Shim, Jang-Sup;Woo, Seon-Mi;Lee, Dong-Ha;Kim, Yong-Sung;Chung, Soon-Key
    • The KIPS Transactions:PartD
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    • v.13D no.7 s.110
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    • pp.1027-1038
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    • 2006
  • There are many technical problems in the recommendation system based on very large database(VLDB). So, it is necessary to study the recommendation system' structure and the data-mining technique suitable for the large scale Internet shopping mail. Thus we design and implement the product recommendation system using k-means clustering algorithm and sequential pattern technique which can be used in large scale Internet shopping mall. This paper processes user information by batch processing, defines the various categories by hierarchical structure, and uses a sequential pattern mining technique for the search engine. For predictive modeling and experiment, we use the real data(user's interest and preference of given category) extracted from log file of the major Internet shopping mall in Korea during 30 days. And we define PRP(Predictive Recommend Precision), PRR(Predictive Recommend Recall), and PF1(Predictive Factor One-measure) for evaluation. In the result of experiments, the best recommendation time and the best learning time of our system are much as O(N) and the values of measures are very excellent.