Violation Of Property Research Articles

Exact non-Markovian dynamics of Gaussian quantum channels: Finite-time and asymptotic regimes

We investigate the Markovian and non-Markovian dynamics of Gaussian quantum channels, exploiting a recently introduced necessary and sufficient criterion and the ensuing measure of non-Markovianity based on the violation of the divisibility property of the dynamical map. We compare the paradigmatic instances of Quantum Brownian motion (QBM) and Pure Damping (PD) channels, and for the former we find that the exact dynamical evolution is always non-Markovian in the finite-time as well as in the asymptotic regimes, for any nonvanishing value of the non-Markovianity parameter. If one resorts to the rotating wave approximated (RWA) form of the QBM, that neglects the anomalous diffusion contribution to the system dynamics, we show that such approximation fails to detect the non-Markovian nature of the dynamics. Finally, for the exact dynamics of the QBM in the asymptotic regime, we show that the quantifiers of non-Markovianity based on the distinguishability between quantum states fail to detect the non-Markovian nature of the dynamics.

A new class of discrete-time stochastic volatility model with correlated errors

ABSTRACTReturns of risky assets and their time-dependent volatility are often jointly modelled by stochastic volatility models (SVMs). Over the last few decades, several SVMs have been proposed to adequately capture the features of the relationship between the return and its volatility. The earliest SVM considers a hierarchical model, with current return as a function of the current latent volatility, which is further modelled as an auto-regressive process. In an attempt to make SVM more appropriate for complex realistic market behaviour, leverage parameter was introduced, which however led to violation of martingale difference property of the risky part of return (a necessary mean-zero condition that prevents arbitrage opportunities under mild regularity conditions). Subsequently, alternative SVMs had been developed and are currently in use. In this article, we propose mean-corrections for several generalizations of SVM with leverage that capture the complex market behaviour as well as satisfy martingale difference property of returns. We also establish a few theoretical results to characterize the key desirable features of these models, and present comparison with other popular competitors. Furthermore, three real-life examples (CITI bank stock price, euro–USD rate and S&P 500 index returns) have been used to demonstrate the performance of this new class of SVMs.

España y los sefarditas de Salónica durante el incendio de 1917

En este artículo quiero poner de relieve la ayuda prestada por el cónsul general de España en Salónica, Teodoro Varela y Gil, a la colonia española, con ocasión del incendio que allí estalló en el verano de 1917, dejando en la ruina a miles de judíos, entre los que se encontraban numerosos protegidos españoles. El diplomático obtuvo del gobierno español la suma de 20.000 francos, contribuyendo al reparto de los socorros enviados desde España entre la comunidad sefardita de Salónica. Varela y Gil expuso también a su gobierno en Madrid las quejas de un grupo de sefarditas españoles que protestaban por la ley de expropiación de los terrenos incendiados que el gobierno griego quería poner en marcha.

A Survey of Symbolic Execution Techniques

Many security and software testing applications require checking whether certain properties of a program hold for any possible usage scenario. For instance, a tool for identifying software vulnerabilities may need to rule out the existence of any backdoor to bypass a program’s authentication. One approach would be to test the program using different, possibly random inputs. As the backdoor may only be hit for very specific program workloads, automated exploration of the space of possible inputs is of the essence. Symbolic execution provides an elegant solution to the problem, by systematically exploring many possible execution paths at the same time without necessarily requiring concrete inputs. Rather than taking on fully specified input values, the technique abstractly represents them as symbols, resorting to constraint solvers to construct actual instances that would cause property violations. Symbolic execution has been incubated in dozens of tools developed over the past four decades, leading to major practical breakthroughs in a number of prominent software reliability applications. The goal of this survey is to provide an overview of the main ideas, challenges, and solutions developed in the area, distilling them for a broad audience.

Rhythmic Keccak: SCA Security and Low Latency in HW

Glitches entail a great issue when securing a cryptographic implementation in hardware. Several masking schemes have been proposed in the literature that provide security even in the presence of glitches. The key property that allows this protection was introduced in threshold implementations as non-completeness. We address crucial points to ensure the right compliance of this property especially for low-latency implementations. Specifically, we first discuss the existence of a flaw in DSD 2017 implementation of Keccak by Gross et al. in violation of the non-completeness property and propose a solution. We perform a side-channel evaluation on the first-order and second-order implementations of the proposed design where no leakage is detected with up to 55 million traces. Then, we present a method to ensure a non-complete scheme of an unrolled implementation applicable to any order of security or algebraic degree of the shared function. By using this method we design a two-rounds unrolled first-order Keccak-

JPR

Java PathFinder (JPF) is a backtrackable Java Virtual Machine (JVM), which is implemented in Java and runs on a standard JVM (e.g., Oracle HotSpot). Thus, a JPF developer can use off-the- shelf Java debuggers (e.g., jdb) when debugging code that makes up JPF. JPF explores all non-deterministic executions of a given target program and monitors for property violations. To facilitate debugging of the target program, JPF can capture and replay the execution trace that leads to a property violation. While the deterministic replay is invaluable, the replay with JPF does not allow the developer to attach an off-the-shelf Java debugger to the target program (e.g., step through the application code, set breakpoints, etc.). We present a technique, dubbed JPR, to improve the debugging experience of the JPF captured traces by migrating the JPF traces to a new format that can be executed using the standard JVM. JPR annotates each JPF trace, during the capture phase, with ex- tra data (e.g., instruction index, instruction count, etc.); the an- notated trace is then used to instrument Java bytecode to enforce the same execution trace on a standard JVM. JPR is compatible with various optimizations, e.g., state matching and partial-order reduction. We evaluated JPR on all multi-threaded Java pro- grams in the official JPF distribution. Our results show that JPR successfully replayed all JPF traces on the standard JVM with reasonable overhead during both recording and replaying.

Topological classification of $Ω$-stable flows on surfaces by means of effectively distinguishable multigraphs

Structurally stable (rough) flows on surfaces have only finitely many singularities and finitely many closed orbits, all of which are hyperbolic, and they have no trajectories joining saddle points. The violation of the last property leads to \begin{document}$Ω$\end{document} -stable flows on surfaces, which are not structurally stable. However, in the present paper we prove that a topological classification of such flows is also reduced to a combinatorial problem. Our complete topological invariant is a multigraph, and we present a polynomial-time algorithm for the distinction of such graphs up to an isomorphism. We also present a graph criterion for orientability of the ambient manifold and a graph-associated formula for its Euler characteristic. Additionally, we give polynomial-time algorithms for checking the orientability and calculating the characteristic.

Violation of Cluster Property in Quantum Antiferromagnet

The cluster property is one of fundamental properties in physics. This property means that there are no relations between two events that are sufficiently separated. Because the cluster property is directly connected with entanglement in quantum field theory and in many-body systems, theoretical and experimental progress on entanglement stimulates us to study this property deeply. In this paper we investigate the cluster property in the spin 1/2 XXZ antiferromagnet on the square lattice with an explicitly symmetry breaking interaction of strength g. In this model spontaneous symmetry breaking occurs when the lattice size N is infinitely large. On the other hand, we have to make g zero in order to obtain quantities in the XXZ model with no symmetry breaking interaction. Since some results depend on the sequence of limit operations — and , it is difficult to draw a clear conclusion in these limits. Therefore we study the model with finite g on the finite lattice, whose size N is supposed to be 1020, for our quantitative calculations. Then we can obtain the concrete ground state. In order to study the cluster property we calculate the spin correlation function. It is known that the function due to Nambu-Goldstone mode (gapless mode), which is calculated using linear spin wave theory, satisfies this property. In this paper we show that almost degenerate states also induce the spin correlation. We assume that the spin correlation function in measurements is a sum of the function due to Nambu-Goldstone mode and one due to these degenerate states. Then we examine whether the additional correlation function violates the cluster property or not. Our conclusion is that this function is finite at any distance, which means the violation of the cluster property, and it is of order of . Except for the case of extremely small g, this violation is the fine effect. Therefore the correlation function due to the degenerate states can be observed only when it is larger than the spin correlation function due to Nambu-Goldstone mode. We show that g required for this condition depends on the distance between positions of two spin operators.

Boundary-spanning demand-side search and radical technological innovations in China

PurposeThe purpose of this paper is to explore how boundary-spanning demand-side search (BSDSS) fuels radical technological innovations as well as how innovation appropriability moderates this relationship. In particular, based on Teece’s (1986) argument regarding the appropriability of innovation, the authors divide factors to influence innovation appropriability into two types: external institution related and internal capability related.Design/methodology/approachThis study employs a survey methodology. Specifically, the authors collected a sample composed of 150 high-tech manufacturing Chinese firms.FindingsResults show that BSDSS has a positive effect on radical technological innovations. Further, the authors find that dysfunctional competition and political ties negatively moderate the main effect, whereas firms’ legal and IPRs protection capabilities positively moderate the main effect.Research limitations/implicationsOne major limitation is that the findings are based on data derived from Chinese firms, which may limit the generalization of the findings.Practical implicationsThe findings suggest that firms competing Chinese market, both Chinese and foreign firms, should actively leverage BSDSS to boost radical technological innovations. Chinese firms should pay attention to the negative roles of appropriability hazards originating from external institutional environment. Foreign firms in Chinese market should be cautious on potential dysfunctional competition from local competitors, such as imitation and intelligence property violation, and enhance appropriability through building internal capabilities, such as legal and IPRs capabilities.Originality/valueThe study highlights the crucial roles of BSDSS in radical technological innovations, as well as the moderating roles of innovation appropriability. These results provide new insights into the drivers of radical technological innovations.

History, Institutions, and Intellectual Property Rights: Debate between the United States and China

Using a point-counterpoint format, this panel seeks to address the key and timely debate over intellectual property rights (IPR) between China and the United States (U.S.). Today, the U.S. takes a strong position on improving and enforcing IPR, especially calling out countries such as China and India for intellectual property violations of technology and cultural content such as films and television. Yet Peng (2013) and Peng, Ahlstrom, Carraher, & Shi (2017) have argued that, during the 19th century the U.S. was not a leading IPR advocate as it is today, but rather, was a leading IPR violator, mostly pilfering British inventions and cultural content. Developing an institution-based view of IPR history, they identify three underlying theoretical mechanisms: path dependence, long-term processes, and institutional transitions. It is sometimes argued that both the U.S. refusal to protect foreign IPR in the 19th century and the current Chinese lack of enthusiasm to meet U.S. IPR demands embody rational responses to their respective situations. However, in the long run, institutional transitions in favor of better IPR protection are possible. Finally, they draw on the IPR history in over 10 other countries to develop a more globally generalizable framework. Begging to differ, Vertinsky argues that China is not in the same position today as the U.S. was in the 19th century, and that the long-term processes affecting its evolution will be quite different. The U.S. and other Western powers should consider the use of any bargaining power that they have now to compel China to enhance IPR protection before it becomes obsolete.

Mapping out Arab international book fairs

PurposeThe purpose of this study is to investigate the status, challenges and impacts of the Arab international book fairs, with particular focus on the Muscat Book Fair. This study proposes a framework to assist in the design and organisation of future Arab book fairs.Design/methodology/approachThe study used a variety of methods to obtain data, including questionnaires, site visits (both regional and international), observations and interviews. A literature review was also undertaken which helped determine major worldwide issues related to aspects of book fairs and the publishing industry, focusing on Arab book fairs.FindingsArab international book fairs remain relatively traditional, however, there are several examples of innovative improvements in some states. Reading habits and literacy trends were found to be influenced by dominant socio-cultural factors, emphasising religion and children’s literature. This seems to have a reverse effect on the publishing industry. Results also revealed a number of disadvantages related to economic downturns and political instability. Despite continuous expansion, Arab book fairs still suffer from various obstacles which affect the publishing industry’s growth. There are other obstacles that they face which are directly associated with distribution and marketing as well as violations of intellectual property laws.Practical implicationsThis study proposes a framework for future improvement of the Muscat Book Fair. It discusses the engagement of local cultural institutions, non-profit community and academic organisations, as well as private sector organisations. These will leverage value and help keep abreast of international developments in book fairs/publishing. It is hoped that the proposed framework will be beneficial to those running book fairs at a regional level, and to countries with developing economies.Originality/valueThere have been no previous empirical studies investigating book fairs in the Arab states. This study adds to the currently scarce body of literature related to book fairs and the publishing industry.

The Imperial Condition of Photography in Palestine: Archives, Looting, and the Figure of the Infiltrator

In front of many cameras and representatives of the international community that surround him, unexpectedly, and outside of any protocol that was prepared for this occasion, an elderly Palestinian man dares to stop, to withdraw his consent to leave his home and ceases to move. This old man is my companion in exploring the archives and attempting to understand its implication in the invention of the figure of “infiltrator.” Together, we refrain from studying his figure, as defined by the nation‐state that forced him out of his home. Halting precisely where many cameras were present, this person threatens to spoil the orchestrated spectacle of Arabs “leaving of their will.” Together, we study the linkage between the expulsion of several hundred thousands of Palestinians and the looting of a vast treasure of books, documents, and photographs from Palestinians in 1948 and their transformation into “abandoned files” in the newly constructed Israeli archives at the same time. The article proposes to relate to the ongoing looting of archives not merely as a violation of Palestinian property and rights, but rather as a continuous performance of national sovereignty. Sovereignty is performed as the continued project of partition of populations into distinct, differentiated groups, whereby violence among the two groups is both the pretext and the effect.

Model-based falsification of an artificial pancreas control system

We present a model-based falsification scheme for artificial pancreas controllers. Our approach performs a closed-loop simulation of the control software using models of the human insulin-glucose regulatory system. Our work focuses on testing properties of an overnight control system for hypoglycemia/hyperglycemia minimization in patients with type-1 diabetes. This control system is currently the subject of extensive phase II clinical trials. We describe how the overall closed loop simulator is constructed, and formulate properties to be tested. Significantly, the closed loop simulation incorporates the control software, as is, without any abstractions. Next, we demonstrate the use of a simulation-based falsification approach to find potential property violations in the resulting control system. We formulate a series of properties about the controller behavior and examine the violations obtained. Using these violations, we propose modifications to the controller software to improve its performance under these adverse (corner-case) scenarios. We also illustrate the effectiveness of robustness as a metric for identifying interesting property violations. Finally, we identify important open problems for future work.

Injunctive Relief in Frand Disputes in the EU Intellectual Property and Competition Law at the Remedies Stage

In dealing with applications for injunctive relief by the holders of FRAND-encumbered SEPs in the course of protracted licensing negotiations, any legal system faces the challenge of reaching the proper balance between predictability for stakeholders and differentiation between possible scenarios (tough negotiations, holdup, holdout or exclusion). In the EU, that challenge fell to be addressed first under the various national laws concerning remedies for intellectual property violations, as partially harmonized by Directive 2004/48. The outcome was not optimal. After German courts introduced competition law in the equation in Orange Book, the European Commission felt compelled to intervene with a different approach in Motorola and Samsung, leading to a reference to the CJEU in Huawei v ZTE. That ruling sets out an elaborate choreography that SEP holder and implementer must respect, in order to avoid breaching Article 102 TFEU or avert injunctive relief, respectively. Huawei represents a satisfactory compromise in practice, but its theoretical foundation in competition law is not solid. Subsequent case-law has unmoored Huawei from competition law and is turning it into a stand-alone lex specialis for injunctions in FRAND cases. In the longer run, legislative intervention might be preferable to de facto harmonization via competition law.

Criminality among Former Child and Adolescent Psychiatric Patients and Matched Controls

Background: Externalizing symptoms in children (aggression, oppositionality, property and status violations), and the Attention Deficit Hyperactivity Disorder (ADHD) triad of problems (inattention, hyperactivity, impulsivity) display a substantial co-morbidity. The “short temper” problem is common to these syndromes, which are predictive of a range of negative life outcomes including substance abuse and criminality in adulthood. There is a gender gap for the syndromes (boys are more affected), for criminality (men are more criminal) and knowledge (we know less about girls’ criminal careers). Aims: The main aim was to compare crime rates and crime profiles among former Child and Adolescent Psychiatric (CAP) patients with corresponding data for matched controls, focusing externalizing and internalizing psychiatric symptoms, sex and adverse social factors. Method: Data for 6055 former CAP-Stockholm outpatients were extracted from available treatment registers. For each CAP patient, two matched controls from the general population were randomly selected from the same area of residence, of the same sex and with the same year of birth (N approx. 12,000). Data on criminality for these individuals were obtained from a Swedish police register which also includes crimes committed prior to age 15. Results: Overall, twice as many former CAP patients were registered for crimes at a mean age of 21.4 compared to the controls. The over-representation was larger for crimes of violence. Females were registered for a much lower number of crimes, particularly crimes of violence (gender gap). The gender gap among the CAP patients was smaller than among controls. Compared with controls, CAP patients characterized by externalizing problems at referral had an odds ratio (OR) for crimes of 5 for males and 10 for females. Neglect was the only adverse social factor which was associated with a higher crime rate and affected boys more than girls. Compared to previous Swedish CAP cohorts, the criminality of the current cohort was much higher. Conclusion: In-depth studies of female crime careers characterized by externalising problems are needed. Child psychiatric services must find new and more effective ways of identifying and treating children with such problems, regardless of sex. The findings can guide the choice of strategies which will reduce crime rate.

Violation of cluster decomposition and absence of light cones in local integer and half-integer spin chains

We compute the ground state correlation functions of an exactly solvable chain of integer spins, recently introduced in [R. Movassagh and P. W. Shor, arXiv:1408.1657], whose ground-state can be expressed in terms of a uniform superposition of all colored Motzkin paths. Our analytical results show that for spin s$\ge$2 there is a violation of the cluster decomposition property. This has to be contrasted with s=1, where the cluster property holds. Correspondingly, for s=1 one gets a light-cone profile in the propagation of excitations after a local quench, while the cone is absent for s=2, as shown by time dependent density-matrix-renormalization-group. Moreover, we introduce an original solvable model of half-integer spins which we refer to as Fredkin spin chain, whose ground-state can be expressed in terms of superposition of all Dyck paths. For this model we exactly calculate the magnetization and correlation functions, finding that for s=1/2, a cone-like propagation occurs while for higher spins, s$\ge$3/2, the colors prevent any cone formation and clustering is violated, together with square root deviation from the area law for the entanglement entropy.

Conditions on the violation of the cluster decomposition property in QCD

The behaviour of correlators at large distances plays an important role in the dynamics of quantum field theories. In many instances, correlators satisfy the so-called cluster decomposition property (CDP), which means that they tend to zero for space-like asymptotic distances. However, under certain conditions, it is possible for correlators to violate this property. In the context of quantum chromodynamics (QCD), violation of the CDP for correlators of clusters involving colored fields implies that the strength of the correlations between the colored degrees of freedom in these clusters increases at large distances, which is a sufficient condition for confinement. In this paper, we establish a criterion when the CDP is violated. By applying this criterion to QCD, it turns out that certain lattice results involving the quark and gluon propagators can be interpreted as evidence that quarks and gluons are confined due to a violation of the CDP.

Litigation risk and cash holdings

We use a unique hand-collected dataset on corporate lawsuits to examine the relationship between litigation risk and cash holdings. We find that an increase in litigation risk is associated with a significant increase in cash holdings. In addition, we document a positive relationship between the level of cash holdings and lawsuits related to the violations of labor, intellectual property, contracts, securities, environmental, product liability, medical liability, and other laws.

(De-)Composing Causality in Labeled Transition Systems

In this paper we introduce a notion of counterfactual causality in the Halpern and Pearl sense that is compositional with respect to the interleaving of transition systems. The formal framework for reasoning on what caused the violation of a safety property is established in the context of labeled transition systems and Hennessy Milner logic. The compositionality results are devised for non-communicating systems.

Experimental quantum data locking

Classical correlation can be locked via quantum means--quantum data locking. With a short secret key, one can lock an exponentially large amount of information, in order to make it inaccessible to unauthorized users without the key. Quantum data locking presents a resource-efficient alternative to one-time pad encryption which requires a key no shorter than the message. We report experimental demonstrations of quantum data locking scheme originally proposed by DiVincenzo et al. [Phys. Rev. Lett. 92, 067902 (2004)] and a loss-tolerant scheme developed by Fawzi, Hayde, and Sen [J. ACM. 60, 44 (2013)]. We observe that the unlocked amount of information is larger than the key size in both experiments, exhibiting strong violation of the incremental proportionality property of classical information theory. As an application example, we show the successful transmission of a photo over a lossy channel with quantum data (un)locking and error correction.