Sensitivity analysis for reliable design verification of nuclear turbosets

In this paper, we present an application of sensitivity analysis for design verification of nuclear turbosets. Before the acquisition of a turbogenerator, energy power operators perform independent design assessment in order to assure safe operating conditions of the new machine in its environment. Variables of interest are related to the vibration behaviour of the machine: its eigenfrequencies and dynamic sensitivity to unbalance. In the framework of design verification, epistemic uncertainties are preponderant. This lack of knowledge is due to inexistent or imprecise information about the design as well as to interaction of the rotating machinery with supporting and sub-structures. Sensitivity analysis enables the analyst to rank sources of uncertainty with respect to their importance and, possibly, to screen out insignificant sources of uncertainty. Further studies, if necessary, can then focus on predominant parameters. In particular, the constructor can be asked for detailed information only about the most significant parameters.     

有毒有害气体报警器智能检定装置的研制

为提高检定的准确度和工作效率,保障工作人员的健康,综合运用自动配气技术、图像采集与识别技术、远程控制技术和检定信息系统等,研制一套有毒有害气体报警器智能检定装置.该装置配气精度达到±1％,图像采集识别率达100％,数据处理系统平均响应时间小于5s,具备遥控操作控制功能,提供开放的数据通信接口,能够自动生成、核验、批准和打印检定证书,具有较好的实用价值.     

多孔材料性能模型研究2:实验验证

在三维网状多孔材料"八面体结构模型"及其系列基本物理、力学性能相关数理模型和表征方式基础上,本文对传导和拉伸等若干性能指标的数理关系验证进行了综述。重点讨论了数理关系的实践性、修正系数的合理性、对计算结果的影响、对应致密体的许用应力取值和塑性指数取值等问题。按照这种数理关系,通过多孔产品孔率等基本参量即可计算其电阻率等性能指标,实验结果证明了其可行性。本方法可以优越于有限元等复杂计算。     

分置式牛津型斯特林制冷机的数值分析与实验验证

对分置式牛津型斯特林制冷机进行了数值计算 ,介绍了计算模型考虑到的众多不可逆因素。通过对计算结果与实验结果的对比 ,验证了本文数值计算的准确性 ,说明本文计算模型与数值处理方法是切实可行的     

Development of a safety critical software requirements verification method with combined CPN and PVS: a nuclear power plant protection system application

Safety-critical software systems such as certain nuclear instrumentation and control (NI&C) systems should be developed with thorough verification. This study presents a method of software requirement verification with a case study for a nuclear power plant (NPP) protection system. The verification introduces colored petri net (CPN) for system modeling and prototype verification system (PVS) for mathematical verification. In order to aid flow-through from modeling by CPN to mathematical proof by PVS, an information extractor from CPN models has been developed in this paper. In order to convert the extracted information to the PVS specification language, a translator has also been developed. This combined method has been applied to the functional requirements of the Wolsong NPP Shut Down System #2 (SDS2); logical properties of the requirements were verified. Through this research, guidelines and a tool support for the use of formal methods have been developed for application to NI&C software verification.     

Experimental verification and application of a practical corrosion model for uniformly depassivated steel in concrete

A practical corrosion model for predicting the corrosion rate of uniformly depassivated steel in concrete was previously developed. The model is built on Stern’s earlier work that an optimum anode-to-cathode ratio exists on the steel surface for which the corrosion current reaches a maximum value. Based on this principle, analytical and numerical techniques were used to obtain a relationship among the steel corrosion rate, concrete resistivity, the oxygen concentration on the surface of the member, oxygen diffusion coefficient, and cover thickness. The main objective of this paper is to present an extensive experimental verification and application of the developed model. For this purpose, three experimental programs carried out by other research groups were selected. The first set of data was used in the verification of the model when different types of cement are used in concrete. The second study was selected to verify the model with the measured corrosion rates obtained by different instruments to eliminate any concerns that may originate from the corrosion measurement technique. Finally, in the last verification study, the model’s interpretation of the effects of concrete resistivity and the oxygen concentration on the corrosion rate is verified. In all cases, it has been demonstrated that the developed model predicts the experimental observations with reasonable accuracy.     

The step complexity measure for emergency operating procedures: measure verification

In complex systems, such as nuclear power plants (NPPs) or airplane control systems, human errors play a major role in many accidents. Therefore, to prevent an occurrence of accidents or to ensure system safety, extensive effort has been made to identify significant factors that can cause human errors. According to related studies, written manuals or operating procedures are revealed as one of the most important factors, and the understandability is pointed out as one of the major reasons for procedure-related human errors.Many qualitative checklists are suggested to evaluate emergency operating procedures (EOPs) of NPPs. However, since qualitative evaluations using checklists have some drawbacks, a quantitative measure that can quantify the complexity of EOPs is very necessary to compensate for them.In order to quantify the complexity of steps included in EOPs, Park et al. suggested the step complexity (SC) measure. In addition, to ascertain the appropriateness of the SC measure, averaged step performance time data obtained from emergency training records for the loss of coolant accident and the excess steam dump event were compared with estimated SC scores. Although averaged step performance time data show good correlation with estimated SC scores, conclusions for some important issues that have to be clarified to ensure the appropriateness of the SC measure were not properly drawn because of lack of backup data.In this paper, to clarify remaining issues, additional activities to verify the appropriateness of the SC measure are performed using averaged step performance time data obtained from emergency training records. The total number of available records is 36, and training scenarios are the steam generator tube rupture and the loss of all feedwater. The number of scenarios is 18 each. From these emergency training records, averaged step performance time data for 30 steps are retrieved.As the results, the SC measure shows statistically meaningful correlation with averaged step performance time data. In addition, since it is observed that the SC measure seems to have the procedure independent property (i.e. steps that have similar SC scores, whether they are included in different procedures or not, would have similar step performance time), it can be concluded that the SC measure can represent the complexity of steps included in EOPs.     

信息融合技术及其在包装工业中的应用

论述了多传感器信息融合技术(MIF)的结构,从工业应用的角度出发探讨和提出了一种多传感器信息融合的结构模型.将经典的统计理论和估计理论以及现代的信息理论和人工智能理论应用于信息融合,通过学科交叉和边沿化,形成了多传感器信息融合的算法和理论.提出了一种用于包装工业的多传感器信息融合控制系统模型,为多传感器信息融合在包装工业控制中的应用迈出了一步.     

中央空调系统节能改造方案的节能量测量及验证方法初探

通过调研中央空调系统节能改造项目相关案例,分析和归纳目前常用的中央空调系统节能改造措施及策略。重点介绍GB／T287502012规定的节能量测量和验证方法,明确不同方法在中央空调系统中的适用情况,给出不同方法的典型应用场合和应用示例。     

Experience in evaluating the data of inter-laboratory comparisons for calibration and verification laboratories

Results are presented for approval and comparative analysis of the suggested algorithms and criteria for actual experimental data of inter-laboratory comparisons performed in calibration and verification laboratories of the Belorussian Republic. __________ Translated from Izmeritel’naya Tekhnika, No. 6. pp. 15–21, June, 2007. The article was written for presentation at the fourth international seminar “Mathematical, statistical, and computer support for the quality of measurements.” (see Izmeritel’naya Tekhnika, Nos. 2–5, 2007).     

Application of genetic algorithms in production and operations management: a review

Over the last decade, there has been a rapid growth of the use of genetic algorithms in the various areas of production and operations management. This paper provides a review of genetic algorithms research published in twenty-one major production and operations management journals from 1990–2001. More specifically, it identifies research trends and publication outlets of genetic algorithms applications. Our findings show that there are only a handful of production and operations management areas to which genetic algorithms have been applied as the solution approach. Furthermore, we recognize and discuss potential research areas and outlets in which researchers may target their work as well as the need for top ranked POM journals to consider publishing genetic algorithms related papers.     

Image analysis algorithm and verification for on-line molecular sieve size and shape inspection

An online machine vision inspection method is proposed to implement feedback control of molecular sieve growth process in rotary drum granulation. An experimental platform, comprising of a high-resolution digital camera and an image analysis system, has been developed to confirm the validity of the method on particle size distribution (PSD) and sphericity measurements. Experiments were performed with non-uniform molecular sieve particles (1–3 mm diameter) obtained from production line. The particle images are first obtained through digital camera and are then processed by image analysis system. After separating the overlap particles and removing non-target particles of the images, the molecular sieve size and shape are computed in less than 0.9 s. The validity of the size measuring accuracy is confirmed through comparing with the results from micrometer. The experimental results show that the repetitive precision of the proposed inspection system is about ±1%, the diameter measurement error between image method and micrometer is about ±3%, single image inspection speed is around 0.9 s/frame. The proposed method is reliable to provide feedback information for control system in rotary drum granulation.     

Models,algorithms and performance analysis for adaptive operating room scheduling

The complex optimisation problems arising in the scheduling of operating rooms have received considerable attention in recent scientific literature because of their impact on costs, revenues and patient health. For an important part, the complexity stems from the stochastic nature of the problem. In practice, this stochastic nature often leads to schedule adaptations on the day of schedule execution. While operating room performance is thus importantly affected by such adaptations, decision-making on adaptations is hardly addressed in scientific literature. Building on previous literature on adaptive scheduling, we develop adaptive operating room scheduling models and problems, and analyse the performance of corresponding adaptive scheduling policies. As previously proposed (fully) adaptive scheduling models and policies are infeasible in operating room scheduling practice, we extend adaptive scheduling theory by introducing the novel concept of committing. Moreover, the core of the proposed adaptive policies with committing is formed by a new, exact, pseudo-polynomial algorithm to solve a general class of stochastic knapsack problems. Using these theoretical advances, we present performance analysis on practical problems, using data from existing literature as well as real-life data from the largest academic medical centre in The Netherlands. The analysis shows that the practically feasible, basic, 1-level policy already brings substantial and statistically significant improvement over static policies. Moreover, as a rule of thumb, scheduling surgeries with large mean duration or standard deviation early appears good practice.     

Commercial accounting for thermal energy in heat sources: Problems and resolution

Problems of accounting for thermal energy from heat sources are considered.Translated from Izmeritelnaya Tekhnika, No. 11, pp. 63–66, November, 2004.     

Cell model for nonlinear fracture analysis – II. Fracture- process calibration and verification

A cell endowed with the micro-separation characteristics of the material is critical to formulating a predictive tool for nonlinear fracture mechanics analysis. This companion article addresses the second step in a two-step calibration scheme, namely, the calibration of the fracture-process parameters D and f0. The discrete, three-dimensional nature of a cell element enables it to capture important features of (i) interaction between the cell elements forming the fracture process zone and the crack including a single cavity-crack tip interaction and (ii) interaction between the fracture process and the plastic dissipation in the background material. The full three-dimensional computational model is applied to two crack geometries known to give rise to significantly different crack tip constraints and crack growth resistance behavior. Details of the load, displacement and crack growth histories in these specimens including the measured three-dimensional crack profiles are accurately predicted by the computational model. The comparison of model predictions and test data of surface cracked plates loaded by different combinations of tension and bending is reported in the third paper (Gao et al., 1997) in this series. This revised version was published online in July 2006 with corrections to the Cover Date.     

Stability analysis and experimental verification for optimum notch configuration in chevron-notched round bar specimens

In some earlier communications [Ray and Poddar, FFEMS, 27 (2004), Sarkar and Ray, FFEMS, 31 (2008)], a methodology to estimate the minimum normalized stress intensity factor for chevron-notched round bar (CVNRB) specimens has been outlined. The primary aim of this report is to theoretically analyse stable crack propagation in CVNRB specimens in order to estimate conservative fracture toughness value associated with this specimen geometry. The theoretical analyses have been substantiated using fracture toughness tests on CVNRB specimens of steel having initial normalized notch lengths (α₀) between 0.2 and 0.5. The major inferences drawn from this investigation are: (1) the optimum notch geometry in CVNRB specimens corresponds to 0.2 < α₀ < 0.3 for the maximum stable crack extension, and (2) the estimated fracture toughness of the steel using CVNRB specimens indicates minimum K_ICV at α₀= 0.29 in good agreement with the theoretical analyses.     

生物医学表面界面信息新概念及光电测试系统

虽然生物力学和生物流变学发展很快，涉及的内容和对病理生理的阐明起了很大作用，但尚未从生物医学表面界面信息方面进行研究，本文填充了这一不足之处，从理论上阐明了生物医学表面界面的信息和新概念，用表面波光栅衍射的新方法开辟了获取与处理生物表面界面信息的新途径和新技术，从而为研究生物医学表面界面与病理生理之间的联系，提供了新的科学依据，起到了独特的功效。     

气象用湿敏电容传感器的稳定性测试与分析

为研究湿敏电容传感器的稳定性特征,利用14支湿敏电容传感器静态测试数据,用误差年漂移量定量表征湿敏电容传感器的稳定性,并对误差年漂移量的变化规律及影响因素进行分析。结果表明,湿敏电容传感器的稳定性受温度、温度和湿度的交互作用以及厂家制造水平的影响,低温时稳定性较差;室温时稳定性随湿度升高而降低。经过一年的使用,78.6%的湿敏电容传感器无法满足技术指标要求。     

A framework for evaluating hydrogen control and management

The present paper presents a new framework for assessing accident management strategies using decision trees. The containment event tree (CET) model considers characteristics associated with the implementation of each strategy. It is constructed and quantified using data obtained from NUREG-1150, other probabilistic risk assessments, and the MAAP4 calculations. The proposed framework for evaluating hydrogen control strategies is based on the concept of a measure using a risk triplet. Ulchin units of nuclear power plants 3 and 4 are used as the reference plant. On the basis of best-estimate assessment, it is shown that it is beneficial to execute hydrogen igniters rather than to do nothing with respect to expected value of hydrogen concentration in the containment during an accident. The proposed approach is shown to be flexible in that it can be applied to various accident management strategies based on the timing of mitigation. The advantage of using the CET for assessing an accident management strategy lies with its capability for modeling both the positive and negative aspects associated with progression of the accident, which may in turn affect the containment failure mode.     

一种车间生产实时监测及信息网络化技术的分析与实现

当前，我国把“以信息化带动工业化”的战略提到重要议程上来，应用计算机信息化管理，提升企业现代化管理水平已成为共识。本文就是根据某车间的实际情况，基于传统的MIS系统开发的一套车间管理控制系统，对车间生产进行实时检测，并将生产信息网络化，从而满足了车间加快市场响应速度，提高生产效率及资源利用率，改善信息流等迫切要求。