• Title/Summary/Keyword: Hard Real-time Systems

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A Study on Distributed & Intelligent Platform for Digital Contents (디지털 콘텐츠 저장 및 유통을 위한 분산 지능형 플랫폼에 관한 연구)

  • 장연세;임승린;나오키엔도
    • Journal of the Korea Society of Computer and Information
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    • v.8 no.3
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    • pp.53-60
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    • 2003
  • In these day, Digital Contents is authorized in forms of HTML and various kind of multi-media by an enterprise and/or organization. At this circumstances, it is very hard or impossible to search a contents between them. Futhermore, you may have to change your contents service systems to extend to cover more user services needs. On this paper, we propose a new architecture to get extendability and empowered interoperability without any maintenance, update or changes. And we introduce the OMG's CORBA to make fault resilient system and to provide a load balancing using a distributed process mechanism. Even more, we adopted the SyncML specification. It can help us to make it real to synchronize between DBMS at real-time. So all these are support easy content synchronization and user-friendness.

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Bounding Worst-Case Data Cache Performance by Using Stack Distance

  • Liu, Yu;Zhang, Wei
    • Journal of Computing Science and Engineering
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    • v.3 no.4
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    • pp.195-215
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    • 2009
  • Worst-case execution time (WCET) analysis is critical for hard real-time systems to ensure that different tasks can meet their respective deadlines. While significant progress has been made for WCET analysis of instruction caches, the data cache timing analysis, especially for set-associative data caches, is rather limited. This paper proposes an approach to safely and tightly bounding data cache performance by computing the worst-case stack distance of data cache accesses. Our approach can not only be applied to direct-mapped caches, but also be used for set-associative or even fully-associative caches without increasing the complexity of analysis. Moreover, the proposed approach can statically categorize worst-case data cache misses into cold, conflict, and capacity misses, which can provide useful insights for designers to enhance the worst-case data cache performance. Our evaluation shows that the proposed data cache timing analysis technique can safely and accurately estimate the worst-case data cache performance, and the overestimation as compared to the observed worst-case data cache misses is within 1% on average.

Optimal RM Scheduling for Simply Periodic Tasks on Uniform Multiprocessors (유니폼 멀티프로세서 환경에서 단순 주기성 태스크를 위한 최적 RM 스케줄링)

  • Jung, Myoung-Jo;Cho, Moon-Haeng;Kim, Joo-Man;Lee, Cheol-Hoon
    • The Journal of the Korea Contents Association
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    • v.9 no.12
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    • pp.52-63
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    • 2009
  • The problem of scheduling simply periodic task systems upon a uniform multiprocessor is considered. Partitioning of periodic task systems requires solving the bin-packing problem, which is known to be intractable (NP-hard in the strong sense). This paper presents a global scheduling algorithm which transforms a given simply periodic task system into another using a "task-splitting" technique. Each transformed simply periodic task system is guaranteed to be successfully scheduled upon any uniform multiprocessor using a partitioned scheduling algorithm. It is proven that the proposed algorithm achieves the theoretical maximum utilization bound upon any uniform multiprocessor platform.

Functional Design of Manufacturing Quote Services for Collaboration between Designer and Manufacturer (설계와 제조간 협업을 위한 제조견적서비스의 기능설계)

  • Joo, Jaekoo;Jeong, Buhwan;Ko, Jee-Hoon
    • Journal of Korean Institute of Industrial Engineers
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    • v.34 no.2
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    • pp.255-269
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    • 2008
  • The increasing dynamic and distributed nature of a business and manufacturing environment makes it hard to collaborate between design and manufacturing parties. The seamless collaboration necessitates a manufacturing quote service (MQS) that delivers manufacturing quotes timely for designer's requests. After envisioning a SOA-inherited collaboration framework, the paper details MQS' functionalities, and syntax and semantics of collaboration messages (i.e., RFQ and manufacturing quote). The MQS is implemented as a Web Service so as to be accessible by designers. For each RFQ, the MQS adaptively generates a responding manufacturing quote by using the DPM library and real-time shop status information. The paper also presents an evolution process that shows the whole process of RQF generation from given product design data. The proposed framework enabled partners to exchange engineering data rapidly and adaptively during the dynamic collaboration, and also increased the benefits of distributed and global production.

Heuristic Algorithms for Resource Leveling in Pre-Erection Scheduling and Erection Scheduling of Shipbuilding (조선 선행탑재 및 탑재 일정계획에서의 부하평준화를 위한 발견적 기법)

  • Woo, Sang-Bok;Ryu, Hyung-Gon;Hahn, Hyung-Sang
    • IE interfaces
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    • v.16 no.3
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    • pp.332-343
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    • 2003
  • This paper deals with pre-erection scheduling and erection scheduling in shipbuilding. Among shipbuilding scheduling, the ship erection scheduling in a dock is one of the most important since the dock is the most critical resource in a shipyard. However, it is more reasonable to consider pre-erection scheduling and erection scheduling as unified because they compete with the common constrained resources such as labor, crane, space, and so on. It is very hard to consider two scheduling problems simultaneously, and hence, we approach them sequentially. At first, we propose space resource leveling heuristics in pre-erection scheduling given erection date. And then, considering the manpower resource determined by pre-erection scheduling, we also propose manpower resource leveling heuristics in erection scheduling. Various experimental results with real world data show that the proposed heuristics have good performance in terms of scheduling quality and time.

Unified Detection and Tracking of Humans Using Gaussian Particle Swarm Optimization (가우시안 입자 군집 최적화를 이용한 사람의 통합된 검출 및 추적)

  • An, Sung-Tae;Kim, Jeong-Jung;Lee, Ju-Jang
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.4
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    • pp.353-358
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    • 2012
  • Human detection is a challenging task in many fields because it is difficult to detect humans due to their variable appearance and posture. Furthermore, it is also hard to track the detected human because of their dynamic and unpredictable behavior. The evaluation speed of method is also important as well as its accuracy. In this paper, we propose unified detection and tracking method for humans using Gaussian-PSO (Gaussian Particle Swarm Optimization) with the HOG (Histograms of Oriented Gradients) features to achieve a fast and accurate performance. Keeping the robustness of HOG features on human detection, we raise the process speed in detection and tracking so that it can be used for real-time applications. These advantages are given by a simple process which needs just one linear-SVM classifier with HOG features and Gaussian-PSO procedure for the both of detection and tracking.

A Practical Implementation of Fuzzy Fingerprint Vault

  • Lee, Sun-Gju;Chung, Yong-Wha;Moon, Dae-Sung;Pan, Sung-Bum;Seo, Chang-Ho
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.5 no.10
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    • pp.1783-1798
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    • 2011
  • Recently, a cryptographic construct, called fuzzy vault, has been proposed for crypto-biometric systems, and some implementations for fingerprint have been reported to protect the stored fingerprint template by hiding the fingerprint features. In this paper, we implement the fuzzy fingerprint vault, combining fingerprint verification and fuzzy vault scheme to protect fingerprint templates. To implement the fuzzy fingerprint vault as a complete system, we have to consider several practical issues such as automatic fingerprint alignment, verification accuracy, execution time, error correcting code, etc. In addition, to protect the fuzzy fingerprint vault from the correlation attack, we propose an approach to insert chaffs in a structured way such that distinguishing the fingerprint minutiae and the chaff points obtained from two applications is computationally hard. Based on the experimental results, we confirm that the proposed approach provides higher security than inserting chaffs randomly without a significant degradation of the verification accuracy, and our implementation can be used for real applications.

An Efficient Method for Design and Implementation of Tweet Analysis System (효율적인 트윗 분석 시스템 설계 및 구현 방법)

  • Choi, Minseok
    • Journal of Digital Convergence
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    • v.13 no.2
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    • pp.43-50
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    • 2015
  • Since the popularity of social network services (SNS) rise, the data produced from them is rapidly increased. The SNS data includes personal propensity or interest and propagates rapidly so there are many requests on analyzing the data for applying the analytic results to various fields. New technologies and services for processing and analyzing big data in the real-time are introduced but it is hard to apply them in a short time and low coast. In this paper, an efficient method to build a tweet analysis system without inducing new technologies or service platforms for handling big data is proposed. The proposed method was verified through building a prototype monitoring system to collect and analyze tweets using the MySQL database and the PHP scripts.

An Exploratory Study on the Factors Affecting the Success and Utilization of Reestablished Knowledge Management Systems in a Customer Center: Case of K Life Insurance (고객센터 지식관리시스템 재구축 성공과 활용에 영향을 미치는 요인에 관한 탐색적 연구: K 보험사 사례를 중심으로)

  • Hong, Byung Sun;Koh, Joon;Cheong, Ki Ju
    • Knowledge Management Research
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    • v.17 no.3
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    • pp.93-116
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    • 2016
  • Knowledge, as a source of firm's competitive edges, has been drawing attention, while numerous enterprises are investing huge amount of assets to foster the right environments for executing knowledge management (KM). As a practical way of such KM, knowledge management systems (KMS) support the creation, diffusion, and utilization of knowledge, which are the tools for practicing such management style. Recently, the customer centers which make the closest contact with the customers are being concerned about the establishment of KMS. Considering the characteristics of real-time problem solving in customer centers during the consultation with the customers, the importance of KMS is paramount to the centers. This study analyzes major factors influencing the success and utilization of the customer center KMS's reestablishment, as an exploratory case study of the reestablishment of KMS in the customer center of K insurance company. First, the characteristic differences between the customer center's KMS and the traditional KMS are discussed, and the triangulation technique is applied to secure objectivity of this case study's findings. Major results of the case study state that, for the success of KMS and improvement of utilization, the followings should be considered preferentially: excellent system quality (accessibility, user convenience, easy searching, speed/menus); high information quality (accuracy, usefulness, timeliness, task-relevance, diversity, degree of specification); appropriate operation strategy and process for the utilization of system (education, training opportunity, appropriate personnel, speed and procedure of approval, compensation/evaluation); and change management via the support from the CEO's level (concern and participation of CEO, will to propel the project, investment, advertisement, etc.). This study provides practical suggestions with respect to factors which should be more carefully dealt with, since still many customer centers have hard time establishing and operating KMS due to lack of previous studies.

A Recovery Scheme of SSD-based Databases using Snapshot Log (스냅샷 로그를 사용한 SSD 기반 데이터베이스 복구 기법)

  • Lim, Seong-Chae
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.19 no.4
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    • pp.85-91
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    • 2019
  • In this paper, we propose a new logging and recovery scheme that is suited for the high-performance transaction processing system base on flash memory storage. The proposed scheme is designed by considering flash's I/O characteristic of asymmetric costs between page update/read operations. That is, we substitute the costly update operation with writing and real-time usage of snapshot log, which is for the page-level physical redo. From this, we can avoid costly rewriting of a dirty page when it is evicted form a buffering pool. while supporting efficient revery procedure. The proposed scheme would be not lucrative in the case of HDD-based system. However, the proposed scheme offers the performance advance sush as a reduced number of updates and the fast system recovery time, in the case of flash storage such as SSD (solid state drive). Because the proposed scheme can easily be applied to existing systems by saving our snapshot records and ordinary log records together, our scheme can be used for improving the performance of upcoming SSD-based database systems through a tiny modification to existing REDO algorithms.