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Fiber-reinforced Foamed Urethane (FFU) synthetic sleeper is used in ballasted track with the potential problem of insufficient lateral resistance due to lower weight and smooth surface compared with concrete sleepers. In this paper, the lateral resistance of prototype and modified FFU synthetic sleepers was investigated by single tie push tests and Discrete Element Method (DEM) analysis, where the real shape of ballast particles was created using the 3D scanning technique. Results indicate that due to the smooth surface of sleeper facets, the lateral resistance of prototype FFU sleepers is reduced by 10-15% and governed by the interactions of shoulder ballast and sleeper ends. On the other hand, modification of the sleeper shape by adding FFU strip block along sleeper base and sides increased lateral resistance up to 19% of prototype sleepers with higher interlocking ability between ballast and sleeper sides. Results could be used to develop modified FFU sleepers for application in various ballasted tracks. [ABSTRACT FROM AUTHOR]

Railway traffic control is based on specialized devices that are designed to exclude collision runs that may lead to loss of safety. A research issue arises in the context of determining effective maintenance intervals and the manner of conducting a technical service policy for existing devices. The aim of the article is to determine the structure of reliability research of selected railway traffic control devices in the aspect of device structure, the current strategy and the state of knowledge on service strategies. The article describes railway traffic control devices to discuss the issue of scheduling technical maintenance of this type of system. [ABSTRACT FROM AUTHOR]

This paper captures the processes by which the French revolutionary and Napoleonic wars redefined enduringly the logics of interaction between Prussia/Germany and France. It explains transformations of power, political imagination and social organisation that are key to understanding the 'special' nature of contemporary German-French relations. The paper finds that historical and international relations narratives fail to address the entire range of system-level transformations in the international order. Making use of approaches and concepts such as liminality, communitas, mimetic theory and the sacred, this paper proposes a novel, political anthropological perspective on such transformations, conceiving them as the interlocking of mimetic binds. First, I present wars and revolutions as liminal moments of collective threshold experiences. Second, I show how the liminal process functions at the international system-level. Third, I explain the challenge that the approach of liminality is posing to theories of international and systemic change. Fourth, I analyse the liminal process in Prussia and show how the said wars brought the French and the Prussians/Germans in a long-term mimetic rivalry. Finally, I argue that the proposed theoretical framework can take the research on international institutions and nationalism beyond the narratives of sociology, political science and historical studies. [ABSTRACT FROM AUTHOR]

A stabilized thermo-hydro-mechanical (THM) finite element model is introduced to investigate the freeze–thaw action of frozen porous media in the finite deformation range. By applying the mixture theory, frozen soil is idealized as a composite consisting of three phases, i.e., solid grain, unfrozen water and ice crystal. A generalized hardening rule at finite strain is adopted to replicate how the elasto-plastic responses and critical state evolve under the influence of phase transitions and heat transfer. The enhanced particle interlocking and ice strengthening during the freezing processes and the thawing-induced consolidation at the geometrical nonlinear regimes are both replicated in numerical examples. The numerical issues due to lack of two-fold inf–sup condition and ill-conditioning of the system of equations are addressed. Numerical examples for engineering applications at cold region are analyzed via the proposed model to predict the impacts of changing climate on infrastructure at cold regions. [ABSTRACT FROM AUTHOR]

Control systems for parallel compressor trains consist of a discharge pressure, anti-surge and load-sharing regulation. Control of a parallel compressor system has proven to be challenging because the control targets usually exhibit control interactions between the different control loops. To decouple this control interference, Mitsubishi Heavy Industries has developed an advanced feed-forward control structure for parallel fixed-speed compressor systems. However, operation in the presence of an unpredictable disturbance presents a few technical challenges for this structure. Most of these problems result in poor load sharing and then operation in the recycle mode in order to protect the system from surge conditions. Moreover, an anti-surge control delay occurs when operating under a low load. To overcome these problems, an improved control structure that incorporates an additional discharge flow controller signal and a nonlinear signal calculator for anti-surge valve control is proposed. To demonstrate the benefits of the proposed method, the control performance of the conventional control structure is compared to that of the proposed control structure. The target process is a parallel fixed-speed compressor system for a fuel gas supply plant. The improved control structure allows for desired load-sharing control, which is not possible with the conventional control structure. The improved control structure manages to exit the anti-surge control region, whereas the conventional control structure activates the interlock system. [ABSTRACT FROM AUTHOR]

Effects of particle shape on the durability (as determined from micro-Deval test) and performance [as determined from resilient modulus (MR), and permanent deformation (PD) tests] of unbound aggregate base (UAB) used in road structures have been evaluated in detail. Four crushed aggregates with different mineralogy (but similar angularity) were selected, and each aggregate type was mixed based on varying particle shapes (ranging from flat to equidimensional) to create dense-and open-graded gradations. The findings showed that the increase in flatness ratio affects the compaction and interlocking characteristics of the open-graded UAB materials much more than the densegraded UAB materials. For open-graded UAB samples, the MR of the aggregates, regardless of the mineralogy, increased with increasing flatness ratio. The MR values of the dense-graded aggregates had an observed peak value at a flatness ratio of 0.6, whereas the final permanent strain during PD testing increased with increasing flatness ratio at the higher stress conditions tested. The effect of the particle shape was modeled using the MEPDG model, and the results showed that particle shape may have an effect on the overall performance. [ABSTRACT FROM AUTHOR]

The schemotechnical solutions of object controllers (OCs) cannot be generally accessible due to their technological value. At the same time, OCs are an integral part of computer-based interlocking systems (CBIS), and study of their operation is required to determine the prospects of development and training of the service staff of CBIS. To replenish the insufficient information, the analysis has been carried out per the description of CBIS EBILOCK 950 and the circuit-based technical solution for high-power outputs of MOT OC for three-phase e-motors of alternating current is offered. The proposed schemotechnical solution comprises also a set of diagnostic tools (DT). This set enables to follow the technical condition of power elements of MOT OC, as well as the technical condition of the object of control and diagnosing (OCD), which increases the penetration depth of DT. Application of the expanded set of DT in high-power outputs of MOT OC, allows to ensure more efficient maintenance process of point machine. The maintenance efficiency is achieved through use of technical diagnosis of OCD and determines the maintenance frequency, ensuring the timeliness of preventive work. [ABSTRACT FROM AUTHOR]

In this article, we present a method and an associated toolchain for the formal verification of the new Danish railway interlocking systems that are compatible with the European Train Control System (ETCS) Level 2. We have made a generic and reconfigurable model of the system behaviour and generic safety properties. This model accommodates sequential release – a feature in the new Danish interlocking systems. To verify the safety of an interlocking system, first a domain-specific description of interlocking configuration data is constructed and validated. Then the generic model and safety properties are automatically instantiated with the well-formed description of interlocking configuration data. This instantiation produces a model instance in the form of a Kripke structure, and concrete safety properties expressed as invariants. Finally, using a combination of SMT based bounded model checking (BMC) and inductive reasoning, it is verified that the generated model instance satisfies the generated safety properties. Using this method, we are able to verify the safety properties for model instances corresponding to railway networks of industrial size. Experiments show that BMC is also efficient for finding bugs in the railway interlocking designs. Additionally, benchmarking results comparing the performance of our approach with alternative verification techniques on the interlocking models are presented. [ABSTRACT FROM AUTHOR]

We present an operationally simple iterative coupling strategy for the synthesis of oligomeric homo- and hetero[n]rotaxanes with precise control over the position of each macrocycle. The exceptional yield of the AT-CuAAC reaction, combined with optimized conditions that allow the rapid synthesis of the target oligomers, opens the door to the study of precision-engineered oligomeric interlocked molecules. [ABSTRACT FROM AUTHOR]

Railway transportation system is a critical sector where design methods and techniques are defined by international standards in order to reduce possible risks to an acceptable minimum level. CENELEC 50128 strongly recommends the utilization of finite state machines during system modelling stage and formal proof methods during the verification and testing stages of control algorithms. Due to the high importance of interlocking table at the design state of a signalization system, the modelling and verification of interlocking tables are examined in this work. For this purpose, abstract state machines are used as a modelling tool. The developed models have been performed in a generalized structure such that the model control can be done automatically for the interlocking systems. In this study, NuSMV is used at the verification state. Also, the consistency of the developed models has been supervised through fault injection. The developed models and software components are applied on a real railway station operated by Metro Istanbul Co. [ABSTRACT FROM AUTHOR]

An interlocking system monitors the status of the objects in a railway yard, allowing or denying the movement of trains, in accordance with safety rules. The high number of complex interlocking rules that guarantee the safe movements of independent trains in a large station makes the verification of such systems a complex task, which needs to be addressed in conformance with EN50128 safety guidelines. In this paper we show how the problem has been addressed by a manufacturer at the final validation stage of production interlocking systems, by means of a model extraction procedure that creates a model of the internal behaviour, to be exercised with the planned test suites, in order to reduce the high costs of direct validation of the target system. The same extracted model is then subject to formal verification experiments, employing an iterative verification process implementing slicing and CEGAR-like techniques, defined to address the typical complexity of this application domain. [ABSTRACT FROM AUTHOR]

Purpose: Recent advancements in technology have enabled railway organizations to shift from manual to computer based automated interlocking systems for increasing their efficiency and profits. Since automated systems are complex and interlocking systems are safety critical systems, these systems should be modeled and verified against safety requirements to weed out any design bugs which might lead to catastrophes during their system life cycles. In this study, we model software based automated interlocking control system of a train station, located at Rawalpindi Cantt (Pakistan). Methods: We have modeled software based automated interlocking control system using timed automata and verified its correctness using UPPAAL model checking software. Timed automata have successfully been used for the modeling and verification of real-time systems. Results: We constructed a real-time model of railyard interlocking system by employing a model-checking approach to determine behavior of the model under various conditions. The model checker ascertains the absence of errors in a system by inspecting all the possible states or scenarios of the modeled system. The results show that important properties related to the safety of the designed interlocking system of the railyard management system can be verified using our presented approach. These properties ranged from collision and de-railment avoidance to checking the correct error handling functionality of the timed automata models. Conclusions: The final modular design can easily adapt to the route upgrades and changes within the station by simple variable adjustments. Based on the laid down methodology and verification techniques, this study can be further built upon, extended and linked to cover the shunting aspect of the train station operations, run through operations, introducing automatic train stop (ATS) functionality and recommend three to four aspect traffic signaling for the train station. This study takes a first step in providing an indigenous solution to an indigenous problem of designing an upgraded and verified signaling infrastructure for Pakistan Railway's Rawalpindi Cantt train station. [ABSTRACT FROM AUTHOR]

Despite years of railway control and signalling development, modern formal description methods are still not widely used. Lack of standards in the interlocking logic construction method causes the development of the railway control systems to be more and more expensive. Moreover, the microprocessor technology used nowadays reaches its limits regarding signal processing time in decentralised systems. This forces the industry to seek for new solutions. This paper presents an algorithmic approach to interlocking logic development, together with a modern implementation methods using hardware description languages and programmable devices. [ABSTRACT FROM AUTHOR]

The safety analysis of interlocking railway systems involves verifying freedom from collision, derailment and run-through (that is, trains rolling over wrongly-set points). Typically, various unrealistic assumptions are made when modelling trains within networks in order to facilitate their analyses. In particular, trains are invariably assumed to be shorter than track segments; and generally only a very few trains are allowed to be introduced into the network under consideration. In this paper we propose modelling methodologies which elegantly dismiss these assumptions. We first provide a framework for modelling arbitrarily many trains of arbitrary length in a network; and then we demonstrate that it is enough with our modelling approach to consider only two trains when verifying safety conditions. That is, if a safety violation appears in the original model with any number of trains of any and varying lengths, then a violation will be exposed in the simpler model with only two trains. Importantly, our modelling framework has been developed alongside – and in conjunction with – railway engineers. It is vital that they can validate the models and verification conditions, and – in the case of design errors – obtain comprehensible feedback. We demonstrate our modelling and abstraction techniques on two simple interlocking systems proposed by our industrial partner. As our formalization is, by design, near to their way of thinking, they are comfortable with it and trust it. [ABSTRACT FROM AUTHOR]

This paper describes a tool for extracting formal safety conditions from interlocking tables for railway interlocking systems. The tool has been applied to generate safety conditions for the interlocking system at Stenstrup station in Denmark, and the SAL model checker tool has been used to check that these conditions were satisfied by a model of the relay circuits implementing the interlocking system at Stenstrup station. [ABSTRACT FROM AUTHOR]

We describe a novel framework for modelling railway interlockings which has been developed in conjunction with railway engineers. The modelling language used is CSP $$||$$ B. Beyond the modelling we present a variety of abstraction techniques which make the analysis of medium- to large-scale networks feasible. The paper notably introduces a covering technique that allows railway scheme plans to be decomposed into a set of smaller scheme plans. The finitisation and topological abstraction techniques are extended from previous work and are given formal foundations. All three techniques are applicable to other modelling frameworks besides CSP $$||$$ B. Being able to apply abstractions and simplifications on the domain model before performing model checking is the key strength of our approach. We demonstrate the use of the framework on a real-life, medium-size scheme plan. [ABSTRACT FROM AUTHOR]

ABSTRACT There are a variety of economic and ecological benefits to increased resource efficiency. Social, institutional and technical innovations can all contribute towards efficiency increases. Companies face different hurdles in fostering such innovation. Small and medium-sized companies are subject to specific constraints that may prevent them from benefiting from innovation-induced resource efficiency improvements. Qualitative interviews were conducted among German small and medium-sized enterprises (SMEs) and intermediaries to identify barriers for resource efficiency innovations and to elaborate a policy mix at the federal level that could help SMEs to overcome these. We found five major barriers to resource efficiency innovations in German SMEs, comprising deficits in innovation culture, inter-firm cooperation along the value chain, finance, awareness and take-up of government funds. We propose a distinct policy mix as a response to this situation. The policy mix comprises the interlocking and synergistic elements of government funding schemes, innovation agents and innovation laboratories. Copyright © 2014 John Wiley & Sons, Ltd and ERP Environment. [ABSTRACT FROM AUTHOR]

Highlights: [•] Area monitoring system and control system are needed for LIPAc radiation management. [•] To secure the radiation safety, these systems are linked with two kinds of data path. [•] Hardwired data paths are adopted to realize the fast transfer of interlock signals. [•] Dual LAN and shared memory are adopted to the reliable transfer of monitoring data. [•] Data transfers without unnecessary load are designed and configured for these systems. [Copyright &y& Elsevier]

Railway signaling has become more important over the years, with the increase in railway traffic and the use of highspeed trains. Since the most important aspect of a railway signaling system is safety, the decision-making ?interlocking system? is the critical element of a railway-signaling system. To satisfy the safety standards set for railway-signaling systems, the interlocking software design must be taken into account, using formal methods. In this study, an automata-based railway signaling and interlocking system is introduced and implemented, using a fail-safe programmable logic controller (PLC) on a scale railway model. [ABSTRACT FROM AUTHOR]

Due to the complexity and size of railway interlocking systems, conventional verification and testing techniques are not able to provide sufficient safety assurance. This paper proposes an online observer for safety assurance of railway interlocking systems. The observer provides runtime checking of the states and behaviors of interlocking devices by using a topology-based mathematical model. Route signals, points, and track sections are interpreted in a topological space, and safety properties are expressed as topology theorems. Running synchronously with the interlocking task, the observer conducts safety checks on the route processes and point operations. A case study of an example Chinese railway interlocking system is presented to illustrate the proposed method and its strengths. It is anticipated that this method will provide a fresh means to verify safety properties of railway interlocking systems in addition to traditional testing and verification methods. [ABSTRACT FROM AUTHOR]

Ballast flying problems obsess the ballasted high speed railway, its microscopic mechanics is less of discovered. In the paper, the railway ballast particle force equilibrium is analyzed through basic mechanics and mathematic formula, and a model is set up to discover the factors and influence. The microscopic ballast flying model is used for ballast bed geometry and ballast shape optimization, and guide the ballast flying countering methods. Results show that ballast flying particle is correlated with ballast shape and mass, especially the ballast shape mass ratio corresponds to operation speed. Ballast interlock ability governs the ballast flying possibility and severity. Ballast flying possibility increases with ballast bed acceleration. The paper focus on ballast particle force equilibration, shape and mass, under the condition of vibration and wind effects, the ballast flying mechanism is analyzed and discussed with related counteracting methods presented. [ABSTRACT FROM AUTHOR]

The paper deals with the significant results of the experimental research of current harmonic spectrum of traction drive with permanent magnet synchronous motor. The experiments were done on a special workplace with a real traction drive for wheel vehicles. Current harmonic spectrum was analyzed by a specialized device on the base of central measuring station. The knowledge of current marked subharmonic components of stator winding is the most significant finding of experiments. The frequencies of these components are given by multiples of frequency of mechanical speeds. The subharmonic components also pass to input DC current of drive. This fact is important in particular from the point of view of legislative requirements to electromagnetic compatibility of drive with railway interlocking devices. [ABSTRACT FROM AUTHOR]

In early stage of safety critical system development, traditional hazard analysis is inaccurate and incomplete. To overcome the shortcomings, a SCADE (safety critical application development environment) model-based approach to functional hazard analysis (FuHA) is proposed. The SCADE data flow was used to construct system functional architecture model and function fault model, and then that two models were integrated into one model. Based on SCADE, the integrated model was analyzed by the way of implementing a risk scenario capturing algorithm and the system safety critical functions and hazards could be identified. The approach is applied to computer based interlocking system in railway signaling application. The simulation result shows that it can increase the precision and completeness for FuHA. [ABSTRACT FROM AUTHOR]

Represented interface model give a possibility to make interconnection between microprocessors interlocking and Auto Block systems. With in interface model will be kept all functional interdependences and safety level. Absence of running cost for interface integration to Auto Block has positive economical effect. Interface model can be easy integrated to any interlocking type what is constructed or under construction in Baltic countries. Conclusion about compatibility interface model with microprocessors interlocking based on detailed research of software and hardware possibilities. [ABSTRACT FROM AUTHOR]

The railway interlocking system, being a safety-critical system, has achieved importance in the railway industry. Advanced technologies are being applied for its modelling, preventing collision and derailing of trains and at the same time allowing efficient movement of trains. In this study, we have applied Z notation by constructing a specification of the critical components of moving block interlocking. Graphs are used for modelling static components and are then integrated with Z to describe its entire state space. At first a real topology is transferred to a model topology in graph theory and then the critical components of the railway network, for example, tracks, switches, crossings and level crossing, are formalised. These components are integrated to define the static part of the system and then dynamic components, the state space of the static part, trains and controls, are integrated to describe the complete system. Formal specification of the system is given using Z and the model is analysed and validated using Z/EVES tool. [ABSTRACT FROM AUTHOR]

The article compares the effectiveness of buzzer-light and starter-interlock reminder systems in automobiles based on the use or nonuse of safety belts in the U.S. It indicates that belts used was increased in urban areas by the introduction of the interlock system in 1974 vehicles. In spite of the interlock system, however, 41 percent of drivers in the 1974 vehicles were not using any belts. Thus, they continued to be unprotected by restraint systems in low to moderate speed crashes. The difference in belt use between 1974 and 1973 vehicles is much greater than year-to-year differences in belt use. The similarity of belt use in registered vehicles suggests that the interlock's effect on belt use persists for at least a few months.

The article presents information on several tips on how to prevent serious consequences from the outcomes of bypassing a safety system. These include the used of interlocks and other protective systems as designed, the verification of the automatic shutoff system's working effectivity during process hazard analyses (PHA), and the failure of a critical instrument or alarm system reporting.