• Title/Summary/Keyword: Dependability engineering

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Design of safety critical and control systems of Nuclear Power Plants using Petri nets

  • Singh, Pooja;Singh, Lalit Kumar
    • Nuclear Engineering and Technology
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    • v.51 no.5
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    • pp.1289-1296
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    • 2019
  • Non-functional requirements plays a critical role in designing variety of applications domain ranges from safety-critical systems to simple gaming applications. Performance is one of the crucial non-functional requirement, especially in control and safety systems, that validates the design. System risk can be quantified as a product of probability of system failure and severity of its impact. In this paper, we devise a technique to do the performance analysis of safety critical and control systems and to estimate performance based risk factor. The technique elaborates Petri nets to estimate performability to ensure system dependability requirements. We illustrate the technique on a case study of Nuclear Power Plant system. The technique has been validated on 17 safety critical and control systems of Nuclear Power Plant.

A New Cryptographic Algorithm for Safe Route Transversal of Data in Smart Cities using Rubik Cube

  • Chhabra, Arpit;Singhal, Niraj;Bansal, Manav;Rizvi, Syed Vilayat
    • International Journal of Computer Science & Network Security
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    • v.22 no.8
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    • pp.113-122
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    • 2022
  • At the point when it is check out ourselves, it might track down various information in each turn or part of our lives. Truth be told, information is the new main thrust of our advanced civilization and in this every day, "information-driven" world, security is the significant angle to consider to guarantee dependability and accessibility of our organization frameworks. This paper includes a new cryptographic algorithm for safe route traversal for data of smart cities which is a contemporary, non-hash, non-straight, 3D encryption execution intended for having information securely scrambled in the interim having a subsequent theoretical layer of safety over it. Encryption generally takes an information string and creates encryption keys, which is the way to unscramble as well. In the interim in another strategy, on the off chance that one can sort out the encryption key, there are opportunities to unravel the information scrambled inside the information string. Be that as it may, in this encryption framework, the work over an encryption key (which is created naturally, henceforth no pre-assurance or uncertainty) just as the calculation produces a "state" in a way where characters are directed into the Rubik block design to disregard the information organization.

Fault Tree Analysis and its Application for Designing High Reliability Electrical System in Underwater Vehicle (수중함 전기 계통의 고 신뢰도 설계를 위한 고장나무분석과 적용)

  • Kim, Jin-San;Choi, Jin-Sung;Bin, Jae-Goo;Kang, Feel-soon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.1
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    • pp.33-39
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    • 2017
  • A top priority in the design of underwater vehicle is to guarantee the dependability of the electric system because failure of the electrical power supply system is directly related to the life of the passengers. In this paper, we present four kinds of alternative designs to improve reliability of electrical system in underwater vehicle. To reduce the risk and to increase availability of the electrical system, we use the redundancy of the grid structure and power converter. For all design alternatives, we carry out Fault Tree Analysis. Based on the FTA result, we implement RAM simulation to compare the risk and availability for the proposed design alternatives.

Modeling and Simulation of Ship Panel-block Assembly Line Using Petri Nets (Petri Nets을 이용한 조선소 패널 블록 조립 라인의 모델링과 시뮬레이션)

  • Han, Sang-Dong;Ryu, Cheol-Ho;Shin, Jong-Gye;Lee, Jong-Kun
    • Korean Journal of Computational Design and Engineering
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    • v.13 no.1
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    • pp.36-44
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    • 2008
  • This paper proposes a modeling and simulation process of a panel production line (PPL) in a shipyard. The panel production line is an assembly process to produce a main panel of a flat block and a curved block. In this paper, its activity analysis is carried out using expression of IDEF0, and its process is qualitatively and quantitatively analyzed and modeled by Petri Nets. A commercial discrete event simulation tool, $QUEST^{TM}$, is used for virtual PPL and simulation. The modeling results by Petri Net are mapped to elements of the simulation tool. Finally, an integrated simulation environment of PPL is implemented in order to efficiently utilize the virtual PPL model. With the help of IDEF0 and Petri Nets, we could systematically analyze and describe the PPL process that are characterized as being concurrent, asynchronous, distributed, parallel, nondeterministic, and/or stochastic. Also, the dynamic and concurrent activities of a PPL system were able to be simulated. A timing concept can be included into the Petri nets model to evaluate performance and dependability issues of the system.

Numerical Analysis of Waves coming with Oblique Angle to Submerged Breakwater on the Porous Seabed (침투층 위의 잠제에 경사각을 가지고 입사하는 파랑의 수치해석)

  • Kim, Nam-Hyeong;Woo, Su-Min
    • Journal of Navigation and Port Research
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    • v.37 no.3
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    • pp.283-289
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    • 2013
  • Wave profiles coming with oblique angle to trapezoidal submerged breakwater on the porous seabed are computed numerically by using a boundary element method. The analysis method is based on the wave pressure function with the continuity in the analytical region including fluid and structure. When compared with the existing results on the oblique incident wave, the results of this study show good agreement. The fluctuation of wave profiles is increased in the rear of the submerged breakwater due to the increase of the transmission coefficient, as the incident angle increases. In addition, in the case of the wave profiles passing over the submerged breakwater on porous seabed, it is able to verify that the attenuation of wave height occurs more significantly due to the wave energy dissipation than that of passing over the submerged breakwater on the impermeable seabed. The results indicate that wave profile own high dependability regarding the change of oblique incident waves and porous seabed. Therefore, the results of this study are estimated to be applied as an accurate numerical analysis referring to oblique incident waves and porous seabed in real sea environment.

A State-of-the-Art Report on the Current Human Error Studies: What and How to Cope with (인적 오류 연구의 동향과 과제: 어떻게 하고 있으며, 무엇이 필요한가?)

  • Lee, Yong-Hee
    • Journal of the Ergonomics Society of Korea
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    • v.30 no.1
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    • pp.1-8
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    • 2011
  • While human error has been one of the main technical issues from the early era of human factors engineering, it still remains hot and somewhat vague due to the various types of the concepts and words on human errors in practice. There may be some technical limitations hindering human error prevention activities. This paper introduces the human error activities described in the papers if this issue of ESK Journal according to a few criteria proposed for more effective technical review. And two basic technical issues are discussed on the concepts, perspectives, and classifications about human errors. Each activity shows its own artifacts associated with the safety purpose and the nature of the industry. This paper also provides a set of new technical bases proposed for a more effective management of human errors by considering the dependability, representativeness, and structuredness of human errors. Additionally, this paper includes some new challenges over the current prevention-oriented activities; positive utilizations of human errors to training/education, advertisements, fun and entertainments, and nudges.

Developing drilling rate index prediction: A comparative study of RVR-IWO and RVR-SFL models for rock excavation projects

  • Hadi Fattahi;Nasim Bayat
    • Geomechanics and Engineering
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    • v.36 no.2
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    • pp.111-119
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    • 2024
  • In the realm of rock excavation projects, precise estimation of the drilling rate index stands as a pivotal factor in strategic planning and cost assessment. This study introduces and evaluates two pioneering computational intelligence models designed for the prognostication of the drilling rate index, a pivotal parameter with direct implications for cost estimation in rock excavation projects. These models, denoted as the Relevance Vector Regression (RVR) optimized with the Invasive Weed Optimization algorithm (IWO) (RVR-IWO model) and the RVR integrated with the Shuffled Frog Leaping algorithm (SFL) (RVR-SFL model), represent a groundbreaking approach to forecasting drilling rate index. The RVR-IWO and RVR-SFL models were meticulously devised to harness the capabilities of computational intelligence and optimization techniques for drilling rate index estimation. This research pioneers the integration of IWO and SFL with RVR, constituting an unprecedented effort in forecasting drilling rate index. The primary objective of this study was to gauge the precision and dependability of these models in forecasting the drilling rate index, revealing significant distinctions between the two. In terms of predictive precision, the RVR-IWO model emerged as the superior choice when compared to the RVR-SFL model, underscoring the remarkable efficacy of the Invasive Weed Optimization algorithm. The RVR-IWO model delivered noteworthy results, boasting a Variance Account for (VAF) of 0.8406, a Mean Squared Error (MSE) of 0.0114, and a Squared Correlation Coefficient (R2) of 0.9315. On the contrary, the RVR-SFL model exhibited slightly lower precision, yielding an MSE of 0.0160, a VAF of 0.8205, and an R2 of 0.9120. These findings serve to highlight the potential of the RVR-IWO model as a formidable instrument for drilling rate index prediction, particularly within the framework of rock excavation projects. This research not only makes a significant contribution to the realm of drilling engineering but also underscores the broader adaptability of the RVR-IWO model in tackling an array of challenges within the domain of rock engineering. Ultimately, this study advances the comprehension of drilling rate index estimation and imparts valuable insights into the practical implementation of computational intelligence methodologies within the realm of engineering projects.

A Novel Grasshopper Optimization-based Particle Swarm Algorithm for Effective Spectrum Sensing in Cognitive Radio Networks

  • Ashok, J;Sowmia, KR;Jayashree, K;Priya, Vijay
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.2
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    • pp.520-541
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    • 2023
  • In CRNs, SS is of utmost significance. Every CR user generates a sensing report during the training phase beneath various circumstances, and depending on a collective process, either communicates or remains silent. In the training stage, the fusion centre combines the local judgments made by CR users by a majority vote, and then returns a final conclusion to every CR user. Enough data regarding the environment, including the activity of PU and every CR's response to that activity, is acquired and sensing classes are created during the training stage. Every CR user compares their most recent sensing report to the previous sensing classes during the classification stage, and distance vectors are generated. The posterior probability of every sensing class is derived on the basis of quantitative data, and the sensing report is then classified as either signifying the presence or absence of PU. The ISVM technique is utilized to compute the quantitative variables necessary to compute the posterior probability. Here, the iterations of SVM are tuned by novel GO-PSA by combining GOA and PSO. Novel GO-PSA is developed since it overcomes the problem of computational complexity, returns minimum error, and also saves time when compared with various state-of-the-art algorithms. The dependability of every CR user is taken into consideration as these local choices are then integrated at the fusion centre utilizing an innovative decision combination technique. Depending on the collective choice, the CR users will then communicate or remain silent.

Stress and fatigue analysis of major components under dynamic loads for a four-row tractor-mounted radish collector

  • Khine Myat Swe;Md Nasim Reza;Milon Chowdhury;Mohammod Ali;Sumaiya Islam;Sang-Hee Lee;Sun-Ok Chung;Soon Jung Hong
    • Korean Journal of Agricultural Science
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    • v.49 no.2
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    • pp.269-284
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    • 2022
  • The development of radish collectors has the potential to increase radish yields while decreasing the time and dependence on human labor in a variety of field activities. Stress and fatigue analyses are essential to ensure the optimal design and machine life of any agricultural machinery. The objectives of this research were to analyze the stress and fatigue of major components of a tractor-mounted radish collector under dynamic load conditions in an effort to increase the design dependability and dimensions of the materials. An experiment was conducted to measure the shaft torque of stem-cutting and transferring conveyor motors using rotary torque sensors at different tractor ground speeds with and without a load. The Smith-Watson-Topper mean stress equation and the rain-flow counting technique were utilized to determine the required shear stress with the distribution of the fatigue life cycle. The severity of the operation was assessed using Miner's theory. All running conditions produced more than 107 of high cycle fatigue strength. Furthermore, the highest severity levels for motor shafts used for stem cutting and transferring and for transportation joints and cutting blades were 2.20, 4.24, 2.07, and 1.07, and 1.97, 3.81, 1.73, and 1.07, respectively, with and without a load condition, except for 5.24 for a winch motor shaft under a load. The stress and fatigue analysis presented in this study can aid in the selection of the most appropriate design parameters and material sizes for the successful construction of a tractor-mounted radish collector, which is currently under development.

Fault Tolerant Processor Design for Aviation Embedded System and Verification through Fault Injection (항공용 임베디드 시스템을 위한 고장감내형 프로세서 설계와 오류주입을 통한 검증)

  • Lee, Dong-Woo;Ko, Wan-Jin;Na, Jong-Wha
    • Journal of Advanced Navigation Technology
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    • v.14 no.2
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    • pp.233-238
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    • 2010
  • In this paper, we applied the forward and backward error recovery techniques to a reduced instruction set computer (risc) processor to develop two fault-tolerant processors, namely, fetch redundant risc (FRR) processor and a redundancy execute risc (RER) processor. To evaluate the fault-tolerance capability of three target processors, we developed the base risc processor, FRR processor, and RER processor in SystemC hardware description language. We performed fault injection experiment using the three SystemC processor models and the SystemC-based simulation fault injection technique. From the experiments, for the 1-bit transient fault, the failure rate of the FRR, RER, and base risc processor were 1%, 2.8%, and 8.9%, respectively. For the 1-bit permanent fault, the failure rate of the FRR, RER, and base risc processor were 4.3%, 6.5%, and 41%, respectively. As a result, for 1-bit fault, we found that the FRR processor is more reliable among three processors.