• Title/Summary/Keyword: 순차탐색

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Study for Android Smartphone's Gallery Thumbnail Forensic Analysis (안드로이드 스마트폰의 갤러리 썸네일(Thumbnail)에 대한 포렌식 분석 방법에 관한 연구)

  • Yun, Daeho;Lee, Sang Jin
    • KIPS Transactions on Computer and Communication Systems
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    • v.6 no.1
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    • pp.31-42
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    • 2017
  • Thumbnail, the small sized graphic file such as JPEG or GIF, serves to help the users to be recognized as a rapidly helps to make it easier recognize while browsing the large sized graphic file. Gallery application, which is installed in a later version of the 4.4.x(Kitkat) Android smartphone records the generated time of graphic file in thumbnail metadata. Thumbnail can be used to draw up the timeline of user action about user's action such as creation, modification, deletion with original graphic file analysis. Also, take advantage of the features thumbnails are stored sequentially in a single thumbcache file, even if the thumbcache is deleted, we can restore the thumbnails. This paper illustrates the feature of thumbnail created by Android OS basic gallery app and methods for utilization in digital forensics.

Pet Location Tracking and Remote Monitoring System using a Wireless Sensor Network (무선센서네트워크를 이용한 애완동물 위치추적 및 원격모니터링 시스템)

  • Hwang, Sung-Ho;Park, Jae-Choon;Kwon, Ki-Hyeon;Choi, Shin-Hyeong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.1
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    • pp.351-356
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    • 2011
  • In this paper, we design a pet location tracking and remote monitoring system that uses ultrasonic, temperature, humidity and illumination sensors to study behavioral patterns and habits. Using ultrasonic waves to calculate distances, a WSN(Wireless Sensor Network) was constructed to transmit data at pet's location, such as temperature, humidity and illumination, to a sink mote. Data received by the system are stored in the database in real time to trace pet's location. Interference among transmitting motes was eliminated by sequentially transmitting RF beacons using sink mote's beacon as the reference signal. Experiments were performed with the laboratory prototype of a pet animal monitoring system implemented for this study. The system analyzes locations of a pet and displays movement patterns, areas of movement, temperature, humidity and illumination using a GUI (graphical user interface).

A Model-Driven Approach for Converting UML Model to OWL-S Ontology (UML 모델을 OWL-S 온톨로지로 변환하기 위한 모델지향접근방식)

  • Kim, Il-Woong;Lee, Kyong-Ho
    • Journal of KIISE:Computing Practices and Letters
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    • v.13 no.3
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    • pp.179-192
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    • 2007
  • Based on ontologies, semantic Web services enable the discovery, selection, and composition. OWL-S is a do facto standard ontology for describing semantics of Web services. Due to the difficulty of the OWL-S grammar, the teaming curve for constructing OWL-S description manually can be steep. This paper presents an efficient method for generating OWL-S descriptions from UML diagrams, which are widely used for software design and development. The proposed method is based on UML profiles to generate an OWL-S ontology from sequence or activity diagrams, which represent the behavior of a business process. Specifically, an XMI file extracted from UML diagrams is transformed into an OWL-S description via an XSLT script. Experimental results with a large volume of UML diagrams show that the proposed method deals with the control flow of complex processes and is superior to previous methods.

High-Speed Search Mechanism based on B-Tree Index Vector for Huge Web Log Mining and Web Attack Detection (대용량 웹 로그 마이닝 및 공격탐지를 위한 B-트리 인덱스 벡터 기반 고속 검색 기법)

  • Lee, Hyung-Woo;Kim, Tae-Su
    • Journal of Korea Multimedia Society
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    • v.11 no.11
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    • pp.1601-1614
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    • 2008
  • The number of web service users has been increased rapidly as existing services are changed into the web-based internet applications. Therefore, it is necessary for us to use web log pre-processing technique to detect attacks on diverse web service transactions and it is also possible to extract web mining information. However, existing mechanisms did not provide efficient pre-processing procedures for a huge volume of web log data. In this paper, we proposed both a field based parsing and a high-speed log indexing mechanism based on the suggested B-tree Index Vector structure for performance enhancement. In experiments, the proposed mechanism provides an efficient web log pre-processing and search functions with a session classification. Therefore it is useful to enhance web attack detection function.

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An Experimental Comparison on Visualization Techniques of Long Menu-Lists (긴 메뉴항목 리스트의 시각화 기법 비교에 관한 실험적 연구)

  • Seo, Eun-Gyoung;Sung, Hye-Eun
    • Journal of the Korean Society for information Management
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    • v.24 no.2
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    • pp.71-87
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    • 2007
  • With the rapid change of the Web and E-transaction application, the search interface is providing more powerful search and visualization methods, while offering smoother integration of technology with task. Especially, visualization techniques for long menu-lists are applied in retrieval system with the goal of improving performance in user's ability to select one item from a long list. In order to review visualization techniques appropriate to the types of users and data set, this study compared the five visualization browsers such as the Tree-structured menu, the Table-of-contents menu, the Roll-over menu, the Click menu, and Fisheye menu. The result of general analyses shows that among the hierarchical methods, the experienced group prefers the Table-of-contents method menu, whereas the novice's group prefers the Tree-structure method menu. Among the linear methods, the two groups prefer the Roll-over menu. The Roll-over menu is most preferred among the five browsers by the two groups.

Matched-target Model Inversion for the Position Estimation of Moving Targets (정합-표적모델 역산을 이용한 기동 표적의 위치 추정)

  • 장덕홍;박홍배;김성일;류존하;김광태
    • The Journal of the Acoustical Society of Korea
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    • v.22 no.7
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    • pp.562-572
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    • 2003
  • A matched-target model inversion method was developed for a passive sonar to estimate the position of moving targets. Based on the well known matched-field processing in underwater acoustics, the method finds target position by matching the measured target directions and frequencies with the corresponding values of the proposed target model. For the efficient and accurate estimations, the parameter searching was accomplished using a hybrid optimizing method, which first starts with a global optimization such as generic algorithm or simulated annealing then applies a local optimization of a simple down hill algorithm. The suggested method was testified using simulations for three different moving scenarios. The simulation results showed that the method is robust in convergence, even under the situation of over 5 times standard deviation of Gaussian distribution of measured error, and is practical in calculation time as well.

An exploratory study on the core spectrum for mobile telecommunication (이동통신 주파수 핵심 우량대역에 관한 탐색 연구)

  • Lee, Seong-Jun;Han, Sung-Soo
    • Journal of Digital Convergence
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    • v.12 no.12
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    • pp.37-47
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    • 2014
  • The characteristics of the spectrum, which are necessary for mobile telecommunication services, may determine the advantage of operators' competition for mobile services. We have a focus on the possibility that there would be the core spectrum within the frequencies. We define the core spectrum of frequencies in terms of 4 criteria (global source/roaming, cost-effectiveness, the experience of utilization and the possibility of use). They are based on the aspects of applicative and economic effectiveness by not technological and but market conditions. We have explored the current core spectrum by using the stepwise selection from these criteria. Our result indicates that the core spectrum may be movable with the development of technology and the flow of time. The results of this paper could be practically used as the reasonable justifications of the policies for not only the competition management but also the alignment about the frequencies for mobile telecommunication.

A Parallel Sphere Decoder Algorithm for High-order MIMO System (고차 MIMO 시스템을 위한 저 복잡도 병렬 구형 검출 알고리즘)

  • Koo, Jihun;Kim, Jaehoon;Kim, Yongsuk;Kim, Jaeseok
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.5
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    • pp.11-19
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    • 2014
  • In this paper, a low complexity parallel sphere decoder algorithm is proposed for high-order MIMO system. It reduces the computational complexity compared to the fixed-complexity sphere decoder (FSD) algorithm by static tree-pruning and dynamic tree-pruning using scalable node operators, and offers near-maximum likelihood decoding performance. Moreover, it also offers hardware-friendly node operation algorithm through fixing the variable computational complexity caused by the sequential nature of the conventional SD algorithm. A Monte Carlo simulation shows our proposed algorithm decreases the average number of expanded nodes by 55% with only 6.3% increase of the normalized decoding time compared to a full parallelized FSD algorithm for high-order MIMO communication system with 16 QAM modulation.

A Study on Frame Interpolation and Nonlinear Moving Vector Estimation Using GRNN (GRNN 알고리즘을 이용한 비선형적 움직임 벡터 추정 및 프레임 보간연구)

  • Lee, Seung-Joo;Bang, Min-Suk;Yun, Kee-Bang;Kim, Ki-Doo
    • Journal of IKEEE
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    • v.17 no.4
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    • pp.459-468
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    • 2013
  • Under nonlinear characteristics of frames, we propose the frame interpolation using GRNN to enhance the visual picture quality. By full search with block size of 128x128~1x1 to reduce blocky artifact and image overlay, we select the frame having block of minimum error and re-estimate the nonlinear moving vector using GRNN. We compare our scheme with forward(backward) motion compensation, bidirectional motion compensation when the object movement is large or the object image includes zoom-in and zoom-out or camera focus has changed. Experimental results show that the proposed method provides better performance in subjective image quality compared to conventional MCFI methods.

An Example-Based Approach to the Synthesis of Rube Goldberg Machines (루브 골드버그 기계의 합성을위한 예제 기반 접근방법)

  • Lee, Kang Hoon
    • Journal of the Korea Computer Graphics Society
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    • v.20 no.2
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    • pp.25-32
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    • 2014
  • We present an example-based approach to synthesizing physically simulated Rube Goldberg machines in which a series of rigid body elements are sequentially triggered and driven along the causal chain. Given a set of elements, our goal is to automatically instantiate and arrange those elements to meet the user-specified requirements including the start and end positions, and the boundary of movement. To do so, we first sample small-scale machines consisting of only a few elements randomly, and represent the connectivity between every pair of components as a graph structure. Searching over possible paths in this graph solves our problem by finding a path that can be unrolled to satisfy the given requirements, and then assembling components sequentially along the solution path. In order to ensure that the machine works precisely in a physically simulated environment, we finally elaborate the layout of assembled components by a simple greedy algorithm. We demonstrate the usefulness of our approach by displaying a large diversity of Rube Goldberg machines built with only five kinds of elements.