• Title/Summary/Keyword: Redundancy design

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Corrective Control of Asynchronous Sequential Machines for Tolerating Permanent Faults (교정 제어를 이용한 비동기 순차 머신의 영구 고장 극복)

  • Yang, Jung-Min
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.47 no.5
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    • pp.9-17
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    • 2010
  • Corrective control compensates the stable-state behavior of asynchronous sequential machines so that the closed-loop system can be changed in a desirable way. Using corrective control, we present a novel fault tolerance scheme that overcomes permanent faults for asynchronous sequential machines. When a permanent fault occurs to an asynchronous machine, the fault is not recovered forever while the machine is irreversibly stuck in a set of failure states. But, if the machine has control redundancy in the limited behavior range, corrective control can be applied to solve the fault tolerance problem against permanent faults. We present the condition on detecting permanent faults and the existence condition of an appropriate corrective controller. The design procedure for the proposed controller is described in a case study.

Implementation of IEEE 1451 based Dual CAN Module for Fault Tolerance of In-Vehicle Networking System (차량 네트워크 시스템의 결함 허용을 위한 IEEE 1451 기반 중복 CAN 모듈의 구현)

  • Lee, Jong-Gap;Kim, Man-Ho;Park, Jee-Hun;Lee, Suk;Lee, Kyung-Chang
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.7
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    • pp.753-759
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    • 2009
  • As many systems depend on electronics in an intelligent vehicle, concern for fault tolerance is growing rapidly. For example, a car with its braking controlled by electronics and no mechanical linkage from brake pedal to calipers of front tires(brake-by-wire system) should be fault tolerant because a failure can come without any warning and its effect is devastating. In general, fault tolerance is usually designed by placing redundant components that duplicate the functions of the original module. In this way a fault can be isolated, and safe operation is guaranteed by replacing the faulty module with its redundant and normal module within a predefined interval. In order to make in-vehicle network fault tolerant, this paper presents the concept and design methodology of an IEEE 1451 based dual CAN module. In addition, feasibility of the dual CAN network was evaluated by implementing the dual CAN module.

A Study on BMS by BDS for Distribution-Business: Business Model System by Buyer's Decision Step

  • Lim, Heon-Wook;Seo, Dae-Sung
    • Journal of Distribution Science
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    • v.17 no.4
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    • pp.27-32
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    • 2019
  • Purpose - The business model is a method of creating corporate value, in existing "classification of business model", limitations and redundancy phenomena are applied when a new type flows in, and as consumer's purchasing decision of consumer behavior 5 steps. The classification schemes can be used for more accurate data analysis by proposing a new mapping technique in the fourth industry. Research design, data, and methodology - It was far more classified on the business model (BMS by BDS), and so on. Designing the new horizons of logistics, marketing, methodology by reclassifying these existing data to new useful data with the old methods, in order to analyze the areas where the problem has been raised for the point that the existing methods are not suitable configured. This will be applicable to the system of quaternary industry from the perspective of the buyer. Results - The mapping results of the consumer purchase decision were as follows,the 1st stage (interest) was 23.73%, 2nd stages (publicity) 33.90%, 3rd stages (sales) 13.56%, 4th stages (decision) 11.86%, 5th stages (repurchaser) 16.95%. This verified that "the business model can be classified through "BMS by BDS". Conclusions - This structural classification is the basis of logistics marketing in the 4th industry, and proposes a innovative and effective model of constructing theory.

A Mapping Technique of XML Documents into Relational Schema based on the functional dependencies (함수적 종속성을 반영향 XML 문서의 관계형 스키마 매핑 기법)

  • Cho, Jung-Gil
    • Journal of Internet Computing and Services
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    • v.8 no.2
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    • pp.95-103
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    • 2007
  • Many techniques have been proposed for mapping from XML to relations, but most techniques did not negotiate the semantics of XML data. The semantics is important to validate storage, query optimization, modification anomaly in process of schema design. Specially, functional dependencies are an important part of database theory, also it is basis of normalization for relational table in BCNF. This paper propose a new technique that reflect functional dependencies to store relation mapped from XML based on XML Schema. The technique can reduce storage redundancy and can keep up content and structure with constraint described by functional dependencies.

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팔의 자세예측을 위한 비용함수의 개발에 관한 연구

  • 최재호;김성환;정의승
    • Proceedings of the ESK Conference
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    • 1994.04a
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    • pp.115-123
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    • 1994
  • A man model can be used as an effective tool to design ergomonically sound products and workplaces, and subsequently evaluate them properly. For a man model to be truly useful, it must be integrated with a posture prediction model which should be capable of representing the human arm reach posture in the context of equipments and workspaces. Since the human movement possesses redundant degrees of freedom, accurate representation or prediction of human movemtn was known to be a difficult problem. To solve this redundancy problem, the psychophysical cost function can predict the arm reach posture accurately. But the joint discomfort that human feels at the joint can not be predicted since the effects of external factors on the joint discomfort is not known. In this study a psychophysical experi- ment using the magnitude estimation technique was performed to evaluate the effects of external factors such as joint, joint angle and Perceived Exertion Ratio on the joint discomfort. Results showed that the joint discomfort increased as the Perceived Exertion Ratio increased, but the relation is not linear and was affected not only by the joint but also by the joint angle for the same Perceived Exertion Ratio. The interaction effect of the joint and the joint angle was also significant. From the results it is needed to develope the cost function which can predict the joint discomfort considering the joint, joint angle and external load.

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A Study on Cable Functional Failure Temperature by Exposed Fire in Nuclear Power Plants (원전 노출 화재시 케이블 기능상실 온도에 관한 연구)

  • Kim, Doo-Hyun;Lim, Hyuk-Soon
    • Journal of the Korean Society of Safety
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    • v.26 no.5
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    • pp.41-45
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    • 2011
  • The fire event occurred in fire proof zone often causes serious electrical problems such as shorts, ground faults, or open circuits in nuclear power plants. These would be directed to the loss of safe shutdown capabilities performed by safety related systems and equipments The fire event can treat the basic design principle that safety systems should keep their functions with redundancy and independency. In case of a cable fire, operators can not perform their mission properly and can misjudge the situation because of spurious operation, wrong indication or instrument. These would deteriorate the plant capabilities of safety shutdown and make disastrous conditions. In this paper, the cables of the representative nuclear power plant in korea is selected and the cable functional failure temperature by exposed fire using Cable Response to Live Fire(CAROLFIRE) is studied. It is expected that the results are very useful to know the cable failure temperature by exposed fire. We confirmed the safety and integrity of the cable by exposed fire and those results will use the based data of cable exposed fire characteristics.

Performance of bridge structures under heavy goods vehicle impact

  • Zhao, Wuchao;Qian, Jiang;Wang, Juan
    • Computers and Concrete
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    • v.22 no.6
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    • pp.515-525
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    • 2018
  • This paper presents a numerical study on the performance of reinforced concrete (RC) bridge structures subjected to heavy goods vehicle (HGV) collision. The objectives of this study are to investigate the dynamic response and failure modes of different types of bridges under impact loading as well as to give an insight into the simplified methods for modeling bridge structures. For this purpose, detailed finite-element models of HGV and bridges are established and verified against the full-scale collision experiment and a recent traffic accident. An intensive parametric study with the consideration of vehicle weight, vehicle velocity, structural type, simplified methods for modeling bridges is conducted; then the failure mode, impact force, deformation and internal force distribution of the validated bridge models are discussed. It is observed that the structural type has a significant effect on the force-transferring mechanism, failure mode and dynamic response of bridge structures, thus it should be considered in the anti-impact design of bridge structures. The impact force of HGV is mainly determined by the impact weight, impact velocity and contact interface, rather than the simplification of the superstructure. Furthermore, to reduce the modeling and computing cost, it is suggested to utilize the simplified bridge model considering the inertial effect of the superstructure to evaluate the structural impact behavior within a reasonable precision range.

Behavioral trends of shear strengthened reinforced concrete beams with externally bonded fiber-reinforced polymer

  • Barakat, Samer;Al-Toubat, Salah;Leblouba, Moussa;Burai, Eman Al
    • Structural Engineering and Mechanics
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    • v.69 no.5
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    • pp.579-589
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    • 2019
  • Numerous experimental studies have been conducted on reinforced concrete (RC) beams strengthened in shear with externally bonded fiber reinforced polymer (EBFRP). The objectives of this work are to study the behavioral trends of shear strengthened EBFRP RC beams after updating the existing database. The previously published databases have been updated, enriched and cross checked for completeness, redundancy and consistency. The updated database now contains data on 698 EBFRP beams and covers the time span from 1992 to 2018. The collected database then refined applying certain filters and used to investigate and capture better interactions among various influencing parameters affecting the shear strength of EBFRP beams. These parameters include the type and properties of FRP, fiber orientation as well as the strengthening scheme, the shear and the longitudinal steel reinforcement ratios, the shear span ratio, and the geometry of the member. The refined database is used to test the prediction accuracy of the existing design models. Considerable scatters are found in the results of all tested prediction models and in many occasions the predictions are unsafe. To better understand the shear behavior of the EBFRP RC beams and then enhance the prediction models, it was concluded that focused experimental programs should be carried out.

Beyond SDLC: Process Modeling and Documentation Using Thinging Machines

  • Al-Fedaghi, Sabah
    • International Journal of Computer Science & Network Security
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    • v.21 no.7
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    • pp.191-204
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    • 2021
  • The software development life cycle (SDLC) is a procedure used to develop a software system that meets both the customer's needs and real-world requirements. The first phase of the SDLC involves creating a conceptual model that represents the involved domain in reality. In requirements engineering, building such a model is considered a bridge to the design and construction phases. However, this type of model can also serve as a basic model for identifying business processes and how these processes are interconnected to achieve the final result. This paper focuses on process modeling in organizations, per se, beyond its application in the SDLC when an organization needs further documentation to meet its growth needs and address regular changes over time. The resultant process documentation is created alongside the daily operations of the business process. The model provides visualization and documentation of processes to assist in defining work patterns, avoiding redundancy, or even designing new processes. In this paper, a proposed diagrammatic representation models each process using one diagram comprising five actions and two types of relations to build three levels of depiction. These levels consist of a static description, events, and the behavior of the modeled process. The viability of a thinging machine is demonstrated by re-modeling some examples from the literature.

Design of Delayed Triple-Core Lock-Step Processor with Memory Rollback for Automotive Applications (메모리 롤백 기능을 가진 차량 어플리케이션용 삼중 코어 지연 락스텝 프로세서 설계)

  • Seonghyun, Yang;Ji-Woong, Choi;Seongsoo, Lee
    • Journal of IKEEE
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    • v.26 no.4
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    • pp.628-632
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    • 2022
  • In this paper, a triple-core delayed lock-step processor is proposed for automotive applications. It performs same operations in three different cores independently, and votes their results to get final values. Therefore its operations are safe even if errors occur in one core. Its three cores operate in a delayed manner to prevent simultaneous errors in multiple cores due to radiative ray or electromagnetic wave. When an error occurs in main core connected to the memory, wrong values can be stored in the memory, so the proposed processor performs memory rollback to restore correct values. Simulation results show that the proposed processor successfully compensates various errors.