共查询到20条相似文献,搜索用时 31 毫秒
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Brian Thoroman Natassia Goode Paul Salmon 《Theoretical Issues in Ergonomics Science》2013,14(6):712-737
AbstractLearning from near misses is an important component of maintaining safe work systems. Within safety science it is widely accepted that a systems approach is the most appropriate for analysing incidents in sociotechnical systems. The aim of this article is to determine whether industry-level near miss reporting systems are consistent with systems thinking. Twenty systems were identified, from a range of work domains, and were evaluated against systems thinking-based criteria. While none of the reporting systems fulfilled the full set of criteria, all are able to identify actors and contributing factors proximal to events in sociotechnical systems and many capture information on how accidents were prevented. It is concluded that the explanatory power of near miss reporting systems is limited by the systems currently used to gather data. The article closes by outlining a research agenda designed to ensure that near miss reporting systems can fully align with the systems approach. 相似文献
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Odd Andreas Asbjornsen 《Engineering Management Journal; EMJ》2013,25(3):30-35
ABSTRACTA set of definitions of systems engineering concepts is the point of departure of this article. Those definitions are generic and cover the system and its life cycle, the systems engineering discipline, and the systems engineering process. A systems engineer must be able to analyze and understand systems first on a conceptual level independent of technology, that is, a technology-free functional analysis. More detailed knowledge and deeper insight into a concrete technology are required later. The systems engineer must be able to move from one system project to another, sometimes with entirely different technologies and requirements. This article points to a need for greater flexibility and easier adaptability on the part of the systems engineer. This need implies that the knowledge base and professional toolbox for the systems engineer must meet this requirement also. A way this requirement can be met is by system similarity and the principle of analogy between functional characteristics of systems. 相似文献
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Kanban control systems have been around for decades and have been used to control work-in-process of manufacturing systems. Lately many variations of the basic control system have been developed; however, much of the work in the development and comparison of control systems has focused on a single-stage manufacturing system producing a single product type. In this research, we present procedures for optimising multiple product kanban control systems, namely Base Stock, Traditional Kanban Control System and Extended Kanban Control System (both dedicated and shared type). We then conduct a detailed simulation study to compare the performance of the systems using a common total cost measure. Numerical results show that the dedicated and shared-extended kanban control systems outperform the other two systems. The study also shows that in spite of their different schematics and contrary to conventional wisdom, the performance of dedicated and shared-extended kanban control systems doesn’t differ much. 相似文献
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目的 构建一套基于用户场景的装配式阳台装修系统解决方案。方法 以装配式阳台系统体系构建为目标,从装配式阳台系统的设计方法、概念、架构、系统模块等方面,对装配式阳台系统进行全面系统的探讨。结果 得出装配式阳台系统由四大基装系统、八大选装系统、三大加载系统构成。结论 装配式阳台系统包括装配式阳台基装系统、装配式阳台选装系统、装配式阳台加载系统。其中基装系统包括:顶面系统、墙面系统、地面系统、封阳系统。选装系统包括:家政模块、晾晒模块、休闲模块、绿植模块、办公模块、健身模块、厨房辅助收纳模块、卧室辅助收纳模块。加载系统包括:智慧照明系统、智慧安防系统、智慧遮阳系统。随着“双碳”目标、大数据、人工智能、新型生活方式的发展,兼顾标准化、工业化、个性化、智能化的多元阳台生活场景的系统解决方案将会得到快速发展。 相似文献
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ABSTRACTA wide variety of estimating software systems for the construction industry is available on the market. Just as the needs of estimators vary greatly, so do the capabilities and applications of these systems. This article summarizes the results of a recent survey of commercially available cost-estimating software systems for the construction industry. The focus of this study is on the Australian market, although a few of the systems reviewed are from the United Kingdom and the United States. The study identifies a list of software features on which the systems are evaluated and summarizes these features in 17 commercially available estimating systems. The benefits of these systems are illustrated by example applications. The article then compares Australian estimating systems to U.K. and U.S. systems, based on similar studies performed by other researchers in those two countries. This article aims to assist users in identifying particular software features currently available from vendors and to provide a basis for the initial comparison of the systems reviewed. It illustrates the current level of development of commercially available computerized estimating systems found in most markets. It can help readers to become aware of the possibilities that now exist for computerized estimating. 相似文献
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This paper is devoted to the study of dynamics of non-autonomous Lorenz systems. These systems are formulated and investigated in the context of non-autonomous dynamical systems. First, we prove that such systems admit a compact global attractor and characterize its structure. Then, we obtain conditions of convergence, under which all solutions of the non-autonomous Lorenz systems approach a point attractor. Third, we derive a criterion for existence of almost periodic, quasi-periodic, periodic, and recurrent motions. Finally, we prove a global averaging principle for non-autonomous Lorenz systems. 相似文献
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稳定性是控制系统分析与设计的基础.探索分数阶系统,特别是分数阶时滞非线性系统的稳定性条件是控制理论与工程领域中的难点问题.本文研究了一类分数阶非线性时滞系统的稳定性和镇定.通过将原系统转化成等价的分数阶积分系统,再借助不等式放缩技术,提出了一个有效且形式简单的确保该类系统稳定新的时滞无关稳定性准则.根据所得的稳定条件,提出了基于时滞线性反馈控制器的镇定控制方法.最后,数值实例验证了所得结果的有效性.此外,本文所使用的方法可以推广和应用于其他类型的分数阶系统的稳定性和镇定控制. 相似文献
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Commuter railroad systems in the US employ three combinations of station platforms and car entranceways. These are high-level platforms with remotely controlled doors and level entranceway (HL-RC), low-level platforms (just above the rail) with steps and remotely controlled doors (LL-RC), and a mixture of the two platform types with a correspondingly more complex, partly manual, door and entranceway arrangement (ML-MO). Much controversy exists over which type of platform/entranceway is better. This seemingly small feature significantly impacts many performance characteristics of these systems, including cost, speed, and boarding and alighting accidents. Northeastern systems are generally moving toward the mixed platform design or all high-level platforms, while systems elsewhere are generally selecting the low-level design. Data on actual accident experience for 1995-2000 are analyzed to determine the effect of platform/entranceway type on passenger and employee injuries. Passenger injury rates on systems with the HL-RC design are lowest, with LL-RC systems next, and ML-MO systems having the highest rates. Employee injury rates are the least on LL-RC systems, but higher on ML-MO and HL-RC systems. Systems with a mixture of high and low platforms (ML-MO) experience a higher overall (combined passenger and employee) injury rate than the other two designs. The implications of these results for both the modernization of existing systems and the design of new systems, in the US and abroad, are discussed. 相似文献
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Jens Hauslage Sebastian M. Strauch Olaf Eßmann Ferdinand W. M. Haag Peter Richter Julia Krüger Julia Stoltze Ina Becker Adeel Nasir Gerhild Bornemann Hartmut Müller Toni Delovski Thomas Berger Aleksandra Rutczynska Karel Marsalek Michael Lebert 《Microgravity science and technology》2018,30(6):933-942
Human space exploration needs stable life support systems for the supply of oxygen, water and food for each human explorer due to long term missions. The most promising approach for building stable life support systems is a combination of physico-chemical and biological systems. These hybrid systems combine the reliability of physico-chemical and the sustainability of biological life support systems. Also the disadvantages, which are the finite resources of physico-chemical and the imperfect reliability of biological systems, are mutually balanced. To improve the reliability of biological life support systems, a combination of different biological systems may stabilize the whole approach during long term operations. The satellite mission Eu:CROPIS (Euglena gracilis: Combined Regenerative Organic-food Production In Space) is a testbed for investigating the behavior of combined biological life support systems under the influence of altered gravity, here, Lunar and Martian gravity. The core systems are a biological trickle filter for processing urine into a fertilizer solution via nitrification and Euglena gracilis, a photosynthetic protist which is able to produce oxygen and biomass while protecting the whole system against high ammonia concentrations. 相似文献
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A life cycle optimization model intended to potentially reduce the environmental impacts of energy use in commercial buildings is presented. A combination of energy simulation, life cycle assessment, and operations research techniques are used to develop the model. In addition to conventional energy systems, such as the electric grid and a gas boiler, cogeneration systems which concurrently generate power and heat are investigated as an alternative source of energy. Cogeneration systems appeared to be an attractive alternative to conventional systems when considering life cycle environmental criteria. Internal combustion engine and microturbine (MT) cogeneration systems resulted in a reduction of up to 38% in global warming potential compared with conventional systems, while solid oxide fuel cell and MT cogeneration systems resulted in a reduction of up to 94% in tropospheric ozone precursor potential (TOPP). Results include a Pareto-optimal frontier between reducing costs and reducing the selected environmental indicators. 相似文献
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Asynchronized automated material handling systems, e.g. automated electrified monorail systems and automated guided vehicle systems, have been playing important roles in manufacturing. Reliability becomes a critical issue as manufacturing enterprises are moving toward automation. In the past, reliability tissue has not been analysed explicitly for these types of systems. In this research, a new measure was proposed to specify reliability. A mixed integer programming model was developed to design flow paths for a special class of material handling systems, i.e. single-loop dual-rail systems. The model can be used to design systems with higher reliability. The model and application procedure in design and analysis were demonstrated through two case studies. 相似文献
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C. Forza 《国际生产研究杂志》2013,51(3):817-836
Offering a large variety of products at competitive prices and reasonable delivery times is a complex managerial challenge that many companies have to address. Software vendors responded to this challenge by developing and proposing various solutions, such as product configuration (PC) systems, product data management (PDM) systems and customer relationship management (CRM) systems. The relative newness, complexity and mutual interdependencies among these systems make it difficult to understand how they—individually and as a whole—actually support a firm in managing its product variety. Precisely these complexities, ultimately, add to the risks of software selection, leading companies to make inconsistent choices or to implement the wrong systems. Starting from this theoretical and practical concern, the present paper provides a conceptualization of the essential functions of PC, PDM and CRM systems, discussing how these functions help a company to manage its product variety and how they relate to each other. This paper proposes that two core data structures of PC systems—namely the sales and technical configuration models—are essential elements of the information management infrastructure of a company offering a large variety of products, because they enable a number of important product variety management functions also present within PDM and CRM systems. 相似文献
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As a consequence of the phasing out of CFCs, sorption systems appear to be potential candidates to replace vapour compression systems. Amongst sorption systems there exists a choice between several systems, such as liquid absorption, solid adsorption and chemical reaction heat pumps. Nevertheless, few comparative studies between these systems have been undertaken so far. It is the aim of this paper to present such a study based on combined first and second law thermodynamical analysis of the different cycles. Simple entropy generation processes explain why the basic cycles for these systems yield performances much lower than the Carnot efficiency. The possibility of operating regenerative cycles with internal heat recovery and higher efficiencies has also been considered for typical common base conditions. Different entropy generation considerations have been visualised, such as thermal coupling (external/internal), non-uniform temperature component entropy production and other irreversible processes for the COP degradation in these systems. It is found that thermal coupling irreversibilities in solid sorption systems and other internal irreversibilities in liquid sorption systems with solution heat exchanger are dominant in the actual COP degradation with respect to the reversible Carnot COP. 相似文献
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The results from several reviews have been presented and the aspects of road safety associated with intelligent transport systems (ITS) applications have been addressed. The attempt is to make a state-of-the-art regarding effects on accidents by categorising systems according to levels of evaluations methods that have been applied. These categories are effects on behaviour, effects on accidents by proxy/surrogate methods, accident studies from real traffic, effects on accident types and finally by meta-analysis where weighted estimates of effects on accidents can be calculated. Thirty-three IT systems including driver assistance systems/advanced driver assistance systems, in-vehicle information systems, in-vehicle data-collection systems and road telematics have been listed. Effects based on meta-analysis are estimated for 11 systems, and single accident studies are found for an additional 2 systems. For the remaining 20 systems, no studies from real road traffic have been identified. Effects on accidents of antilocking brake systems and electronic stability control (ESC) are presented in more detail according to their effects on certain accident types. ESC appears to be very efficient in reducing the number of accidents. Behavioural adaptations to ITS are considered and discussed, especially in terms of compensation mechanisms. Four hypotheses regarding prediction of effects on accidents are stated according to whether systems increase or decrease 'windows of opportunities' by calling upon a driver behaviour model where emotions play a central role 相似文献
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Qingchen Shen Zhen Luo Shuai Ma Peng Tao Chengyi Song Jianbo Wu Wen Shang Tao Deng 《Advanced materials (Deerfield Beach, Fla.)》2018,30(28)
Bioinspired engineering offers a promising alternative approach in accelerating the development of many man‐made systems. Next‐generation infrared (IR) sensing systems can also benefit from such nature‐inspired approach. The inherent compact and uncooled operation of biological IR sensing systems provides ample inspiration for the engineering of portable and high‐performance artificial IR sensing systems. This review overviews the current understanding of the biological IR sensing systems, most of which are thermal‐based IR sensors that rely on either bolometer‐like or photomechanic sensing mechanism. The existing efforts inspired by the biological IR sensing systems and possible future bioinspired approaches in the development of new IR sensing systems are also discussed in the review. Besides these biological IR sensing systems, other biological systems that do not have IR sensing capabilities but can help advance the development of engineered IR sensing systems are also discussed, and the related engineering efforts are overviewed as well. Further efforts in understanding the biological IR sensing systems, the learning from the integration of multifunction in biological systems, and the reduction of barriers to maximize the multidiscipline collaborations are needed to move this research field forward. 相似文献
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Whittaker first put forward a new approach, called the initial motions, to solve the differential equations of motion aimed at holonomic systems. Since most of the differential equations of motion for mechanical systems are nonlinear ordinary ones, which are difficult to find the analytic solutions. Fortunately, the concept of initial motions can manage these situations and study its subsequent motions. This work is devoted to discuss and investigate the initial motions for mechanical systems, particularly for nonholonomic systems. First, the differential equations for holonomic systems are formulated, and the formulation and solution of initial motions of the systems are proposed. Second, the differential equations of motion for nonholonomic systems are established, based on the new method of initial motions to obtain the initial values of high-order derivatives of generalized velocities, the formulation and solution of initial motions are introduced in the general nonholonomic systems and Chaplygin systems. The methods and results obtained are illustrated by a number of classical examples, both for holonomic and nonholonomic systems. 相似文献
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In recent years, many flexible manufacturing systems have been or are being developed. FMS is important in order to adapt to severe changes in market and technology and also to increase productivity. In this paper, the evaluation variables of flexibility are proposed and factors improving the flexibility of single-stage production systems with different characters are discussed. However, most production systems are multi-stage mixed type systems. This paper also points out the characteristics of the amplification of multi-stage production systems as one of the important factors affecting the flexibility and productivity of the systems. Furthermore, some ways of reducing the amplification by the ordering systems are also presented. The multi-stage ordering models discussed here are simplified, neglecting the characteristics of the single production systems which make up total multi-stage production systems and neglecting parameters concerning transportation and material flows. The flexible manufacturing system of today is treated as a stage which is part of an overall system consisting of a succession of production stages with difference characteristics. However, it should also be considered as a way to increase the flexibility and productivity of the system as a whole. 相似文献