Suchergebnisse

International audience ; The paper overview one of the projects at the middle 80-th, supported by USSR government and oriented on breakthrough in hardware/software development. Several academic groups with industrial companies fulfilled a lot of investigations, built prototypes of perspective computers and intellectual programs. Author, as one of participants and headers of START project, analyses some principles of the project organizing structure. Although most brilliant results of START project were not used by industry because of economic and political crisis in Soviet Union, the impact of enthusiastic work and generating new ideas, was great for all major developers. Several opinions of participants are presented in conclusion.

Complex hardware systems become more and more ubiquitous in mission critical applications such as military, satellite, and medical to name but a few. In such applications, reliability remains a primary concern because a failure that occurs during their normal operations might produce important catastrophes like loss of life or loss of money. All these failures are often caused by minuscule bug that exists inside the software which controls the systems, or within the hardware itself. In addition, most of these systems cannot be interrupted while working, even for a few seconds a year, making it difficult to repair bugs found during their normal operations. The main purpose of this work is to build efficient verification techniques for asynchronous concurrent systems. Because of the pivotal roles these systems assume in a given application, designers of such systems must keep development and maintenance costs under control and meet nonfunctional constraints on the design of the system, such as cost, power, weight, or the system architecture by itself. But most importantly, they must assure their customer as well as the certification authorities that both the design and its implementation are correct. Otherwise, they may end up shipping unsafe systems to the market, and the consequences of this action would be catastrophic. To achieve this goal, designers need efficient methods and tools to assist them in verifying the correctness of the design. In this thesis we focus on a symbolic model checking technique called bounded model checking (BMC). BMC is a method targeted mainly at finding bugs in a system. It answers the questions whether there exists a counterexample, shorter than a given length, that violates a given property. During a BMC operation each execution path is encoded into Boolean formula, and the problem is reduced to satisfiability checking of the formula. Therefore, the operation consists mainly in constructing a Boolean formula that is satisfiable if and only if such a counterexample exists. We model our systems with transition systems (TSs). In particular, we are mainly interested in synchronized product of TSs. Since concurrent systems are formed by a combination of several components communicating between each other, synchronized product of TSs is well-suited to capture the behavior of such systems. The executions of concurrent systems are commonly modeled using the so-called interleaving execution, which allows only one single event to fire at each step. However, due to the complexity of such systems inteleaving method will not only require many steps but also generate long formulas. In this work, we adopt another approach based on breadth-first search (BFS). In a BMC operation, the translation of the model into a Boolean formula is polynomial in the size of the model, but the solving time of the Boolean formula can be exponential in the size of the formula. Therefore, our research hypothesis is that we can improve the efficiency of BMC by generating succinct formula, and by minimizing the number of necessary steps during an execution. We introduce several BMC techniques aimed at improving the efficiency of BMC for asynchronous concurrent systems. The techniques are grouped in two main parts (i) techniques for checking reachability properties and (ii) techniques for checking properties written in linear temporal logic (LTL). In addition, we also propose some methods for minimizing the number of execution steps or bound. We implemented all these methods in a BMC toolset. At the end of the dissertation, we will discuss the experimental results we obtained. ; Postprint (published version)

Complex hardware systems become more and more ubiquitous in mission critical applications such as military, satellite, and medical to name but a few. In such applications, reliability remains a primary concern because a failure that occurs during their normal operations might produce important catastrophes like loss of life or loss of money. All these failures are often caused by minuscule bug that exists inside the software which controls the systems, or within the hardware itself. In addition, most of these systems cannot be interrupted while working, even for a few seconds a year, making it difficult to repair bugs found during their normal operations. The main purpose of this work is to build efficient verification techniques for asynchronous concurrent systems. Because of the pivotal roles these systems assume in a given application, designers of such systems must keep development and maintenance costs under control and meet nonfunctional constraints on the design of the system, such as cost, power, weight, or the system architecture by itself. But most importantly, they must assure their customer as well as the certification authorities that both the design and its implementation are correct. Otherwise, they may end up shipping unsafe systems to the market, and the consequences of this action would be catastrophic. To achieve this goal, designers need efficient methods and tools to assist them in verifying the correctness of the design. In this thesis we focus on a symbolic model checking technique called bounded model checking (BMC). BMC is a method targeted mainly at finding bugs in a system. It answers the questions whether there exists a counterexample, shorter than a given length, that violates a given property. During a BMC operation each execution path is encoded into Boolean formula, and the problem is reduced to satisfiability checking of the formula. Therefore, the operation consists mainly in constructing a Boolean formula that is satisfiable if and only if such a counterexample exists. We model our systems with transition systems (TSs). In particular, we are mainly interested in synchronized product of TSs. Since concurrent systems are formed by a combination of several components communicating between each other, synchronized product of TSs is well-suited to capture the behavior of such systems. The executions of concurrent systems are commonly modeled using the so-called interleaving execution, which allows only one single event to fire at each step. However, due to the complexity of such systems inteleaving method will not only require many steps but also generate long formulas. In this work, we adopt another approach based on breadth-first search (BFS). In a BMC operation, the translation of the model into a Boolean formula is polynomial in the size of the model, but the solving time of the Boolean formula can be exponential in the size of the formula. Therefore, our research hypothesis is that we can improve the efficiency of BMC by generating succinct formula, and by minimizing the number of necessary steps during an execution. We introduce several BMC techniques aimed at improving the efficiency of BMC for asynchronous concurrent systems. The techniques are grouped in two main parts (i) techniques for checking reachability properties and (ii) techniques for checking properties written in linear temporal logic (LTL). In addition, we also propose some methods for minimizing the number of execution steps or bound. We implemented all these methods in a BMC toolset. At the end of the dissertation, we will discuss the experimental results we obtained. ; Postprint (published version)

Complex hardware systems become more and more ubiquitous in mission critical applications such as military, satellite, and medical to name but a few. In such applications, reliability remains a primary concern because a failure that occurs during their normal operations might produce important catastrophes like loss of life or loss of money. All these failures are often caused by minuscule bug that exists inside the software which controls the systems, or within the hardware itself. In addition, most of these systems cannot be interrupted while working, even for a few seconds a year, making it difficult to repair bugs found during their normal operations. The main purpose of this work is to build efficient verification techniques for asynchronous concurrent systems. Because of the pivotal roles these systems assume in a given application, designers of such systems must keep development and maintenance costs under control and meet nonfunctional constraints on the design of the system, such as cost, power, weight, or the system architecture by itself. But most importantly, they must assure their customer as well as the certification authorities that both the design and its implementation are correct. Otherwise, they may end up shipping unsafe systems to the market, and the consequences of this action would be catastrophic. To achieve this goal, designers need efficient methods and tools to assist them in verifying the correctness of the design. In this thesis we focus on a symbolic model checking technique called bounded model checking (BMC). BMC is a method targeted mainly at finding bugs in a system. It answers the questions whether there exists a counterexample, shorter than a given length, that violates a given property. During a BMC operation each execution path is encoded into Boolean formula, and the problem is reduced to satisfiability checking of the formula. Therefore, the operation consists mainly in constructing a Boolean formula that is satisfiable if and only if such a counterexample exists. We model ...

In der CNC-Bearbeitung ist es zur Kollisionsvermeidung sehr wichtig, dass real aufgebaute Spannsysteme exakt der Vorgabe aus der CAD/CAM-Simulation entsprechen. In diesem Beitrag wird ein industrietaugliches Assistenzsystem präsentiert, mit dem per Augmented Reality (AR) die manuelle Montage von modularen Spannsystemen unterstützt wird und so Fehler vermieden werden können. Es wird aufgezeigt, dass die Kamera-Monitor-basierte AR geeignet ist, um unter rauen Bedingungen intuitive Montageanleitungen zu visualisieren. Dadurch lassen sich Bearbeitungszeiten in der CNC-Maschine verkürzen und die Montage beschleunigen.

In CNC machining, the similarity of real assembled clamping systems compared to the constructed clampings in CAD/CAM is of critical importance. If differences are present, unintentional collisions between tool and clamping system can occur, which may lead to total breakdown. In this work we present an Augmented Reality (AR) industry-ready assistance solution, which helps workers to reduce the error rate when clamping systems are assembled manually. We will show that camera-screen-based AR is well suited to present assembly instructions in harsh environmental conditions and that by using this solution machining times can be reduced and the assembly itself can be accelerated significantly.

This dissertation conceptualizes a new type of clientelistic party, which despite being widespread has not been properly theorized. I refer to it as modular. Since clientelism — the exchange of goods for votes — requires substantial organization, scholars often assume that only dominant parties or solid political machines can engage in clientelistic mobilization. I show that is not the case. Rather, modular parties are makeshift organizations whose integrity from one election to the next is uncertain, but whose politicians are nevertheless able to mobilize voters through patron-client relationships.Modular parties do not own, but "hire" or outsource the networks of clients they use. Well before the advent of elections, community chiefs, community organization leaders, ethnic leaders, landowners, local officials, and other types of local notables already established considerable political capital through their private and relatively small clienteles. Instead of ignoring or dismantling these networks, politicians running elections above the local level created modular parties to connect these networks. In this sense, modular par- ties are made up of two tiers: one on top, responsible for acquiring state resources and acting at the level of subnational or national politics; and one at the bottom composed of multiple modules, each with a local notable running local politics and acting as broker in favor of the upper stratum. Throughout time, these local leaders may take new roles, such as union leaders, bureaucrats, and local politicians, but they remain responsible for the construction and maintenance of patron–client networks. Today in Brazil, this local no- table is usually a mayoral candidate diligently brokering votes for the party offering most state resources or direct payments.Such outsourcing of the organization of patron-client linkages to local authorities may facilitate the rapid mobilization of voters for politicians in modular parties, but it also prevents these politicians from building a reliable support base. Brokers in modular parties act as free–agents, and switch parties as they see appropriate. As long as there are other parties outsourcing clientelistic mobilization, brokers may switch whenever they receive a more lucrative proposal.Using a research design that detects when parties receive resources they can use to hire brokers as-if randomly, I am able to show that variations in resources cause parties to expand or contract the number of modules working for them. Moreover, taking advantage of an unexpected institutional reform that made party switching potentially costly, and employing regression discontinuities to separate the brokers who were subject to this new ruling, I was able to evaluate how party switching drastically damages the electoral prospects of modular parties.Substantively, the fluidity of modules sheds light on why clientelism can be resilient and widespread on many parts of the developing world, at the same time that strong clientelistic machines are relatively rare. It is durable because brokers offer their services to the highest bidding party, thus maximizing their ability to nurture their networks. However, by relying on these autonomous brokers parties will not create direct linkages of their own, frustrating any hope of making parties organizationally strong.

This book takes up the challenge of developing an empirically based foundation for evolutionary economics built upon complex system theory. The authors argue that modern evolutionary economics is at a crossroads. At a theoretical level, modern evolutionary economics is moving away from the traditional focus of the operation of selection mechanisms and towards concepts of "complex adaptive systems" and self-organisation. On an applied level, new and innovative methods of empirical research are being developed and considered. The contributors take up this challenge and examine aspects of complexity and evolution in applied contexts

AbstractToday we are standing at a critical juncture of societal evolution at which unprecedented human fulfillment as well as the annihilation of the human race are equally possible. However, we are not at the mercy of evolutionary forces but have the potential and the opportunity to give direction to societal evolution by design, provided we create a vision for the future of humankind and develop the will and the competence to realize that vision in all of our human systems, from the family on to the global system of humanity.First I present a brief overview of societal evolution and point out evolutionary gaps that are potential sources of our destruction. I will then suggest we have the power within us to steer societal evolution toward a hoped‐for future, provided we: (1) develop evolutionary consciousness, (2) create an evolutionary vision for societal development, (3) acquire evolutionary competence, and (4) apply our competence in guiding the evolution and development of our sociocultural and socio‐technical systems.In the third part, I elaborate on item (4) above and discuss: (a) a general model for evolutionary guidance, (b) the role of design in societal evolution, and (c) the process by which Evolutionary Guidance Systems can be created and used in societal development.