• Title/Summary/Keyword: minimal graphs

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A Label Graph Based Verifiable Secret Sharing Scheme for General Access Structures

  • Hsu, Ching-Fang;Zeng, Bing;Cheng, Qi
    • Journal of Communications and Networks
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    • v.15 no.4
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    • pp.407-410
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    • 2013
  • Secret sharing is that a dealer distributes a piece of information (called a share) about a secret to each participant such that authorized subsets of participants can reconstruct the secret but unauthorized subsets of participants cannot determine the secret. In this paper, an access structure can be represented by a label graph G, where a vertex denotes a participant and a complete subgraph of G corresponds to a minimal authorized subset. The vertices of G are labeled into distinct vectors uniquely determined by the maximum prohibited structure. Based on such a label graph, a verifiable secret sharing scheme realizing general access structures is proposed. A major advantage of this scheme is that it applies to any access structure, rather than only structures representable as previous graphs, i.e., the access structures of rank two. Furthermore, verifiability of the proposed scheme can resist possible internal attack performed by malicious participants, who want to obtain additional shares or provide a fake share to other participants.

For the quadrangular graphs (사변형 그래프에 관하여)

  • Jeong, Nae-Gyeong;Im, Hyung-Kyu;Park, Se-Won
    • The Journal of the Korea institute of electronic communication sciences
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    • v.5 no.3
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    • pp.239-244
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    • 2010
  • In this paper, we study the adjacency matrix of a minimal connected quadrangular graph G, and then we obtain an upper bound on |E(G)| for such a graph G, and we obtain the graph for which the upper bound is attained. In addition, we obtain an upper bound on |E(G)| for a critical matching covered quadrangular graph G.

Maximum Capacity-based Minimum Cut Algorithm (최대 수용량-기반 최소절단 알고리즘)

  • Lee, Sang-Un
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.5
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    • pp.153-162
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    • 2011
  • The minimum cut problem is to minimize c(S,T), that is, to determine source S and sink T such that the capacity of the S-T cut is minimal. The flow-based algorithm is mostly used to find the bottleneck arcs by calculating flow network, and does not presents the minimum cut. This paper suggests an algorithm that simply includes the maximum capacity vertex to adjacent set S or T and finds the minimum cut without obtaining flow network in advance. On applying the suggested algorithm to 13 limited graphs, it can be finds the minimum cut value $_{\min}c$(S, T) with simply and correctly.

Inter-Factor Determinants of Return Reversal Effect with Dynamic Bayesian Network Analysis: Empirical Evidence from Pakistan

  • HAQUE, Abdul;RAO, Marriam;QAMAR, Muhammad Ali Jibran
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.3
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    • pp.203-215
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    • 2022
  • Bayesian Networks are multivariate probabilistic factor graphs that are used to assess underlying factor relationships. From January 2005 to December 2018, the study examines how Dynamic Bayesian Networks can be utilized to estimate portfolio risk and return as well as determine inter-factor relationships among reversal profit-generating components in Pakistan's emerging market (PSX). The goal of this article is to uncover the factors that cause reversal profits in the Pakistani stock market. In visual form, Bayesian networks can generate causal and inferential probabilistic relationships. Investors might update their stock return values in the network simultaneously with fresh market information, resulting in a dynamic shift in portfolio risk distribution across the networks. The findings show that investments in low net profit margin, low investment, and high volatility-based designed portfolios yield the biggest dynamical reversal profits. The main triggering aspects related to generation reversal profits in the Pakistan market, in the long run, are net profit margin, market risk premium, investment, size, and volatility factor. Investors should invest in and build portfolios with small companies that have a low price-to-earnings ratio, small earnings per share, and minimal volatility, according to the most likely explanation.

Trainees Can Safely Learn Video-Assisted Thoracic Surgery Lobectomy despite Limited Experience in Open Lobectomy

  • Yu, Woo Sik;Lee, Chang Young;Lee, Seokkee;Kim, Do Jung;Chung, Kyung Young
    • Journal of Chest Surgery
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    • v.48 no.2
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    • pp.105-111
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    • 2015
  • Background: The aim of this study was to establish whether pulmonary lobectomy using video-assisted thoracic surgery (VATS) can be safely performed by trainees with limited experience with open lobectomy. Methods: Data were retrospectively collected from 251 patients who underwent VATS lobectomy at a single institution between October 2007 and April 2011. The surgical outcomes of the procedures that were performed by three trainee surgeons were compared to the outcomes of procedures performed by a surgeon who had performed more than 150 VATS lobectomies. The cumulative failure graph of each trainee was used for quality assessment and learning curve analysis. Results: The surgery time, estimated blood loss, final pathologic stage, thoracotomy conversion rate, chest tube duration, duration of hospital stay, complication rate, and mortality rate were comparable between the expert surgeon and each trainee. Cumulative failure graphs showed that the performance of each trainee was acceptable and that all trainees reached proficiency in performing VATS lobectomy after 40 cases. Conclusion: This study shows that trainees with limited experience with open lobectomy can safely learn to perform VATS lobectomy for the treatment of lung cancer under expert supervision without compromising outcomes.

A Study on the Change of Body Composition of Female Adolescents for School Uniform Design (교복 설계를 위한 여자 청소년의 체형 변화 연구)

  • Kim, Seowoo;Nam, Yun Ja;Kim, Kyoung Sun
    • Journal of the Korean Society of Clothing and Textiles
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    • v.44 no.2
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    • pp.224-236
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    • 2020
  • In this study, the 4th (1997) and 6th (2013) direct measurements of Size Korea compared the changing shape of women between the ages of 12 and 18. Comparing the items of height and length, the height and shoulder height were significantly reduced, the waist height was not significantly different, and the height of the upper hip was significantly increased, resulting in a smaller upper torso ratio and a higher lower torso rate. The width and thickness associated with human obesity, the circumference items and obesity levels often increased significantly with the change of the times, indicating that the overall body size was increased and that the chest area was changed to a cylindrical shape with changes in the breast equilibrium. Comparing agespecific measurements with graphs analyzing the trend of change in growth, the results showed that the change in 1997 was minimal since age 14; however, a continuous increase was achieved in 2013 that corresponded to the age at which growth is complete. The results of these studies are expected to be used as basic data to predict pattern design, body implementation, and trends in shape changes for young women.

Proposition and Evaluation of Parallelism-Independent Scheduling Algorithms for DAGs of Tasks with Non-Uniform Execution Time

  • Kirilka Nikolova;Atusi Maeda;Sowa, Masa-Hiro
    • Proceedings of the IEEK Conference
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    • 2000.07a
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    • pp.289-293
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    • 2000
  • We propose two new algorithms for parallelism-independent scheduling. The machine code generated from the compiler using these algorithms in its scheduling phase is parallelism-independent code, executable in minimum time regardless of the number of the processors in the parallel computer. Our new algorithms have the following phases: finding the minimum number of processors on which the program can be executed in minimal time, scheduling by an heuristic algorithm for this predefined number of processors, and serialization of the parallel schedule according to the earliest start time of the tasks. At run time tasks are taken from the serialized schedule and assigned to the processor which allows the earliest start time of the task. The order of the tasks decided at compile time is not changed at run time regardless of the number of the available processors which means there is no out-of-order issue and execution. The scheduling is done predominantly at compile time and dynamic scheduling is minimized and diminished to allocation of the tasks to the processors. We evaluate the proposed algorithms by comparing them in terms of schedule length to the CP/MISF algorithm. For performance evaluation we use both randomly generated DAGs (directed acyclic graphs) and DACs representing real applications. From practical point of view, the algorithms we propose can be successfully used for scheduling programs for in-order superscalar processors and shared memory multiprocessor systems. Superscalar processors with any number of functional units can execute the parallelism-independent code in minimum time without necessity for dynamic scheduling and out-of-order issue hardware. This means that the use of our algorithms will lead to reducing the complexity of the hardware of the processors and the run-time overhead related to the dynamic scheduling.

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Merge Algorithm of Maximum weighted Independent Vertex Pair at Maximal Weighted Independent Set Problem (최대 가중치 독립집합 문제의 최대 가중치 독립정점 쌍 병합 알고리즘)

  • Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.20 no.4
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    • pp.171-176
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    • 2020
  • This paper proposes polynomial-time algorithm for maximum weighted independent set(MWIS) problem that is well known as NP-hard. The known algorithms for MWIS problem are polynomial-time to specialized in particular graph type, distributed, or clustering method. But there is no unified algorithm is suitable to all kinds of graph types. Therefore, this paper suggests unique polynomial-time algorithm that is suitable to all kinds of graph types. The proposed algorithm merges the maximum weighted vertex vi and maximum weighted vertex vj that is not adjacent to vi. As a result of apply to undirected graphs and trees, this algorithm can be get the optimal solution. This algorithm improves previously known solution to new optimal solution.

Hardware-Software Cosynthesis of Multitask Multicore SoC with Real-Time Constraints (실시간 제약조건을 갖는 다중태스크 다중코어 SoC의 하드웨어-소프트웨어 통합합성)

  • Lee Choon-Seung;Ha Soon-Hoi
    • Journal of KIISE:Computer Systems and Theory
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    • v.33 no.9
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    • pp.592-607
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    • 2006
  • This paper proposes a technique to select processors and hardware IPs and to map the tasks into the selected processing elements, aming to achieve high performance with minimal system cost when multitask applications with real-time constraints are run on a multicore SoC. Such technique is called to 'Hardware-Software Cosynthesis Technique'. A cosynthesis technique was already presented in our early work [1] where we divide the complex cosynthesis problem into three subproblems and conquer each subproblem separately: selection of appropriate processing components, mapping and scheduling of function blocks to the selected processing component, and schedulability analysis. Despite good features, our previous technique has a serious limitation that a task monopolizes the entire system resource to get the minimum schedule length. But in general we may obtain higher performance in multitask multicore system if independent multiple tasks are running concurrently on different processor cores. In this paper, we present two mapping techniques, task mapping avoidance technique(TMA) and task mapping pinning technique(TMP), which are applicable for general cases with diverse operating policies in a multicore environment. We could obtain significant performance improvement for a multimedia real-time application, multi-channel Digital Video Recorder system and for randomly generated multitask graphs obtained from the related works.

COMPARISON OF MECHANICAL PROPERTIES OF VARIOUS POST AND CORE MATERIALS

  • Ahn Seung-Geun;Sorensen John A.
    • The Journal of Korean Academy of Prosthodontics
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    • v.41 no.3
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    • pp.288-299
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    • 2003
  • Statement of problem: Many kinds of post and core systems are in the market, but there are no clear selection criteria for them. Purpose: The purpose of this study was to compare the flexural strength and modulus of elasticity of core materials, and measure the bending strength of post systems made of a variety of materials. Material and Methods: The flexural strength and elastic modulus of thirteen kinds core buildup materials were measured on beams of specimens of $2.0{\times}2.0{\times}24{\pm}0.1mm$. Ten specimens per group were fabricated and loaded on an lnstron testing machine at a crosshead speed of 0.25mm/min. A test span of 20 mm was used. The failure loads were recorded and flexural strength calculated with the measured dimensions. The elastic modulus was calculated from the slopes of the linear portions of the stress-stram graphs. Also nine kinds commercially available prefabricated posts made of various materials with similar nominal diameters, approximately 1.25mm, were loaded in a three-point bend test until plastic deformation or failure occurred. Ten posts per group were tested and the obtained data were anaylzed with analysis of variance and compared with the Tukey multiple comparison tests. Results: Clearfil Photo Core and Luxacore had flexural strengths approaching amalgam, but its modulus of elasticity was only about 15% of that of amalgam. The strengths of the glass ionomer and resin modified glass ionomer were very low. The heat pressed glass ceramic core had a high elastic modulus but a relatively low flexural strength approximating that of the lower strength composite resin core materials. The stainless steel, zirconia and carbon fiber post exhibited high bending strengths. The glass fiber posts displayed strengths that were approximately half of the higher strength posts. Conclusion: When moderate amounts of coronal tooth structure are to be replaced by a post and core on an anterior tooth, a prefabricated post and high strength, high elastic modulus core may be suitable. CLINICAL IMPLICATIONS In this study several newly introduced post and core systems demonstrated satisfactory physical properties. However when the higher stress situation exists with only a minimal ferrule extension remaining a cast post and core or zirconia post and pressed core are desirable.