• Title/Summary/Keyword: metric space

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Energy-Aware Self-Stabilizing Distributed Clustering Protocol for Ad Hoc Networks: the case of WSNs

  • Ba, Mandicou;Flauzac, Olivier;Haggar, Bachar Salim;Makhloufi, Rafik;Nolot, Florent;Niang, Ibrahima
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.7 no.11
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    • pp.2577-2596
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    • 2013
  • In this paper, we present an Energy-Aware Self-Stabilizing Distributed Clustering protocol based on message-passing model for Ad Hoc networks. The latter does not require any initialization. Starting from an arbitrary configuration, the network converges to a stable state in a finite time. Our contribution is twofold. We firstly give the formal proof that the stabilization is reached after at most n+2 transitions and requires at most $n{\times}log(2n+{\kappa}+3)$ memory space, where n is the number of network nodes and ${\kappa}$ represents the maximum hops number in the clusters. Furthermore, using the OMNeT++ simulator, we perform an evaluation of our approach. Secondly, we propose an adaptation of our solution in the context of Wireless Sensor Networks (WSNs) with energy constraint. We notably show that our protocol can be easily used for constructing clusters according to multiple criteria in the election of cluster-heads, such as nodes' identity, residual energy or degree. We give a comparison under the different election metrics by evaluating their communication cost and energy consumption. Simulation results show that in terms of number of exchanged messages and energy consumption, it is better to use the Highest-ID metric for electing CHs.

A Vector Tagging Method for Representing Multi-dimensional Index (다차원 인덱스를 위한 벡터형 태깅 연구)

  • Jung, Jae-Youn;Zin, Hyeon-Cheol;Kim, Chong-Gun
    • Journal of KIISE:Software and Applications
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    • v.36 no.9
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    • pp.749-757
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    • 2009
  • A Internet user can easily access to the target information by web searching using some key-words or categories in the present Internet environment. When some meta-data which represent attributes of several data structures well are used, then more accurate result which is matched with the intention of users can be provided. This study proposes a multiple dimensional vector tagging method for the small web user group who interest in maintaining and sharing the bookmark for common interesting topics. The proposed method uses vector tag method for increasing the effect of categorization, management, and retrieval of target information. The vector tag composes with two or more components of the user defined priority. The basic vector space is created time of information and reference value. The calculated vector value shows the usability of information and became the metric of ranking. The ranking accuracy of the proposed method compares with that of a simply link structure, The proposed method shows better results for corresponding the intention of users.

Construction of Theme Melody Index by Transforming Melody to Time-series Data for Content-based Music Information Retrieval (내용기반 음악정보 검색을 위한 선율의 시계열 데이터 변환을 이용한 주제선율색인 구성)

  • Ha, Jin-Seok;Ku, Kyong-I;Park, Jae-Hyun;Kim, Yoo-Sung
    • The KIPS Transactions:PartD
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    • v.10D no.3
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    • pp.547-558
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    • 2003
  • From the viewpoint of that music melody has the similar features to time-series data, music melody is transformed to a time-series data with normalization and corrections and the similarity between melodies is defined as the Euclidean distance between the transformed time-series data. Then, based the similarity between melodies of a music object, melodies are clustered and the representative of each cluster is extracted as one of theme melodies for the music. To construct the theme melody index, a theme melody is represented as a point of the multidimensional metric space of M-tree. For retrieval of user's query melody, the query melody is also transformed into a time-series data by the same way of indexing phase. To retrieve the similar melodies to the query melody given by user from the theme melody index the range query search algorithm is used. By the implementation of the prototype system using the proposed theme melody index we show the effectiveness of the proposed methods.

3D Reconstruction and Self-calibration based on Binocular Stereo Vision (스테레오 영상을 이용한 자기보정 및 3차원 형상 구현)

  • Hou, Rongrong;Jeong, Kyung-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.9
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    • pp.3856-3863
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    • 2012
  • A 3D reconstruction technique from stereo images that requires minimal intervention from the user has been developed. The reconstruction problem consists of three steps of estimating specific geometry groups. The first step is estimating the epipolar geometry that exists between the stereo image pairs which includes feature matching in both images. The second is estimating the affine geometry, a process to find a special plane in the projective space by means of vanishing points. The third step, which includes camera self-calibration, is obtaining a metric geometry from which a 3D model of the scene could be obtained. The major advantage of this method is that the stereo images do not need to be calibrated for reconstruction. The results of camera calibration and reconstruction have shown the possibility of obtaining a 3D model directly from features in the images.

File-System-Level SSD Caching for Improving Application Launch Time (응용프로그램의 기동시간 단축을 위한 파일 시스템 수준의 SSD 캐싱 기법)

  • Han, Changhee;Ryu, Junhee;Lee, Dongeun;Kang, Kyungtae;Shin, Heonshik
    • Journal of KIISE
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    • v.42 no.6
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    • pp.691-698
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    • 2015
  • Application launch time is an important performance metric to user experience in desktop and laptop environment, which mostly depends on the performance of secondary storage. Application launch times can be reduced by utilizing solid-state drive (SSD) instead of hard disk drive (HDD). However, considering a cost-performance trade-off, utilizing SSDs as caches for slow HDDs is a practicable alternative in reducing the application launch times. We propose a new SSD caching scheme which migrates data blocks from HDDs to SSDs. Our scheme operates entirely in the file system level and does not require an extra layer for mapping SSD-cached data that is essential in most other schemes. In particular, our scheme does not incur mapping overheads that cause significant burdens on the main memory, CPU, and SSD space for mapping table. Experimental results conducted with 8 popular applications demonstrate our scheme yields 56% of performance gain in application launch, when data blocks along with metadata are migrated.

Utility Design for Graceful Degradation in Embedded Systems (우아한 성능감퇴를 위한 임베디드 시스템의 유용도 설계)

  • Kang, Min-Koo;Park, Kie-Jin
    • Journal of KIISE:Computer Systems and Theory
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    • v.34 no.2
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    • pp.65-72
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    • 2007
  • As embedded system has strict cost and space constraints, it is impossible to apply conventional fault-tolerant techniques directly for increasing the dependability of embedded system. In this paper, we propose software fault-tolerant mechanism which requires only minimum redundancy of system component. We define an utility metric that reflects the dependability of each embedded system component, and then measure the defined utility of each reconfiguration combinations to provide fault tolerance. The proposed utility evaluation process shows exponential complexity. However we reduce the complexity by hierachical subgrouping at the software level of each component. When some components of embedded system are tailed, reconfiguration operation changes the system state from current faulty state to pre-calculated one which has maximum utility combination.

Exploratory Study to Develop Customers' Experience Measurement Scale of H&B Store

  • NOH, Eun-Jung;CHA, Seong-Soo
    • The Journal of Industrial Distribution & Business
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    • v.11 no.7
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    • pp.51-60
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    • 2020
  • Purpose: Recently, Korean cosmetics distribution market has been reorganized with the H&B store. In the domestic cosmetics distribution market, existing brand road shops are decreasing, and multi-shops are leading the H & B stores, which have greatly improved their experience and content. In these environmental changes, the offline distribution channels are turning into the multi-editing shops that have introduced products of various brands and greatly enhanced experiences and contents. Nevertheless, most studies of factors and measurement items for measuring customer experience in the H&B store use Schmitt (1999)'s Strategic Experience Modules (SEMs). Therefore, the purpose of this study is to propose a measure that is practicable through consideration of the in-store customer experience components of the H&B store. Research design, data and methodology: Based on Schmitt's Strategic Experience Modules (SEMs), which are widely used in customer experience marketing, the metric pool was constructed through customer and literature research on H & B store managers. Since then, 101 preliminary surveys and 211 main surveys have been conducted in order to propose a dimension of customer experience and refine the metrics. Results: As a result of the research, H&B store's customer experience was derived from a measurement model consisting of 19 measurement items in total of five dimensions: environmental experience, intellectual experience, behavioral experience, tech experience, and relationship experience. This study analyzed that compared to the existing Schmitt's Strategic Experience Modules (SEMs), (1) emotional experience expanded to environmental experience, (2) Cognitive and relationship experiences are maintained (3) behavioral experience was subdivided into physical and technical experiences. In particular, the environmental experience has been proposed as a major component is an important point because the H&B store recently opened a large flagship store and is competitive in constructing a differentiated space. Conclusions: Related experience was seen as an important component of customer experience in the offline store, but in the process of refining the scale, interaction items with employees of the H&B store were removed, and rather, participation in the APP or SNS channel of the company, event Participation, interaction with other customers, etc. appear to be important, while suggesting the practical implications.

Analysis of Harmonic Mean Distance Calculation in Global Illumination Algorithms (전역 조명 알고리즘에서의 조화 평균 거리 계산의 분석)

  • Cha, Deuk-Hyun;Ihm, In-Sung
    • Journal of KIISE:Computing Practices and Letters
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    • v.16 no.2
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    • pp.186-200
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    • 2010
  • In order to render global illumination realistically, we need to accurately compute the direct and indirect illumination that represents the light information incoming through complex light paths. In this process, the indirect illumination at given point is greatly affected by surrounding geometries. Harmonic mean distance is a mathematical tool which is often used as a metric indicating the distance from a surface point to its visible objects in 3D space, and plays a key role in such advanced global illumination algorithms as irradiance/radiance caching and ambient occlusion. In this paper, we analyze the accuracy of harmonic mean distance estimated against various environments in the final gathering and photon mapping methods. Based on the experimental results, we discuss our experiences and future directions that may help develop an effective harmonic mean distance computation method in the future.

A Study on Classification of Waveforms Using Manifold Embedding Based on Commute Time (컴뮤트 타임 기반의 다양체 임베딩을 이용한 파형 신호 인식에 관한 연구)

  • Hahn, Hee-Il
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.2
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    • pp.148-155
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    • 2014
  • In this paper a commute time embedding is implemented by organizing patches according to the graph-based metric, and its properties are investigated via changing the number of nodes on the graph.. It is shown that manifold embedding methods generate the intrinsic geometric structures when waveforms such as speech or music instrumental sound signals are embedded on the low dimensional Euclidean space. Basically manifold embedding algorithms only project the training samples on the graph into an embedding subspace but can not generalize the learning results to test samples. They are very effective for data clustering but are not appropriate for classification or recognition. In this paper a commute time guided transform is adopted to enhance the generalization ability and its performance is analyzed by applying it to the classification of 6 kinds of music instrumental sounds.

An Approach to the BIM-enabled Assessment of Building Circulation using Quantitative Data and its Weight (동선관련 정성적 요구사항 평가를 위한 가중치를 적용한 BIM기반 정량데이터 활용방안에 관한 연구)

  • Shin, Jaeyoung;Lee, Jin-Kook
    • Journal of Digital Contents Society
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    • v.16 no.2
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    • pp.335-343
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    • 2015
  • This paper describes a quantitative approach to the BIM-enabled assessment of building circulation by using quantitative data and applying its weight. Assessment of building circulation plays an important role before construction stage because of related requirements regulated by design guide, building codes, etc. and design decision making as well. In this paper, Qualitative issue is mainly dealt with that are usually excluded from rule checking objects due to their implicit definition such as 'comfortable circulation'. A weighting framework is suggested using weighted data of circulation properties such as 1) metric distance, 2) number of passing spaces, 3) number of turning spaces, 4) window area of passing space, etc.