Discounting in LTL

In recent years, there is growing need and interest in formalizing and reasoning about the quality of software and hardware systems. As opposed to traditional verification, where one handles the question of whether a system satisfies, or not, a given specification, reasoning about quality addresses the question of \emph{how well} the system satisfies the specification. One direction in this effort is to refine the "eventually" operators of temporal logic to {\em discounting operators}: the satisfaction value of a specification is a value in $[0,1]$, where the longer it takes to fulfill eventuality requirements, the smaller the satisfaction value is. In this paper we introduce an augmentation by discounting of Linear Temporal Logic (LTL), and study it, as well as its combination with propositional quality operators. We show that one can augment LTL with an arbitrary set of discounting functions, while preserving the decidability of the model-checking problem. Further augmenting the logic with unary propositional quality operators preserves decidability, whereas adding an average-operator makes some problems undecidable. We also discuss the complexity of the problem, as well as various extensions

Containment and equivalence of weighted automata: Probabilistic and max-plus cases

This paper surveys some results regarding decision problems for probabilistic and max-plus automata, such as containment and equivalence. Probabilistic and max-plus automata are part of the general family of weighted automata, whose semantics are maps from words to real values. Given two weighted automata, the equivalence problem asks whether their semantics are the same, and the containment problem whether one is point-wise smaller than the other one. These problems have been studied intensively and this paper will review some techniques used to show (un)decidability and state a list of open questions that still remain

A methodology pruning the search space of six compiler transformations by addressing them together as one problem and by exploiting the hardware architecture details

Today’s compilers have a plethora of optimizations-transformations to choose from, and the correct choice, order as well parameters of transformations have a significant/large impact on performance; choosing the correct order and parameters of optimizations has been a long standing problem in compilation research, which until now remains unsolved; the separate sub-problems optimization gives a different schedule/binary for each sub-problem and these schedules cannot coexist, as by refining one degrades the other. Researchers try to solve this problem by using iterative compilation techniques but the search space is so big that it cannot be searched even by using modern supercomputers. Moreover, compiler transformations do not take into account the hardware architecture details and data reuse in an efficient way. In this paper, a new iterative compilation methodology is presented which reduces the search space of six compiler transformations by addressing the above problems; the search space is reduced by many orders of magnitude and thus an efficient solution is now capable to be found. The transformations are the following: loop tiling (including the number of the levels of tiling), loop unroll, register allocation, scalar replacement, loop interchange and data array layouts. The search space is reduced (a) by addressing the aforementioned transformations together as one problem and not separately, (b) by taking into account the custom hardware architecture details (e.g., cache size and associativity) and algorithm characteristics (e.g., data reuse). The proposed methodology has been evaluated over iterative compilation and gcc/icc compilers, on both embedded and general purpose processors; it achieves significant performance gains at many orders of magnitude lower compilation time

Racism and hate speech – A critique of Scanlon’s Contractual Theory

The First Amendment is an important value in American liberal polity. Under this value, racism, hate speech and offensive speech are protected speech. This article scrutinizes one of the clear representatives of the American liberal polity - Thomas Scanlon. The paper tracks the developments in his theory over the years. It is argued that Scanlon’s arguments downplay tangible harm that speech might inflict on its target victim audience. Scanlon’s distinction between participant interests, audience interests, and the interests of bystanders is put under close scrutiny. The article criticizes viewpoint neutrality and suggests a balancing approach, further arguing that democracy is required to develop protective mechanisms against harm-facilitating speech as well as profound offences. Both should be taken most seriously

First international new intravascular rigid-flex endovascular stent study (FINESS): Clinical and angiographic results after elective and urgent stent implantation

Objectives. The purpose of this study was to determine the feasibility, safety and efficacy of elective and urgent deployment of the new intravascular rigid-flex (NIR) stent in patients with coronary artery disease. Background. Stent implantation has been shown to be effective in the treatment of focal, new coronary stenoses and in restoring coronary flow after coronary dissection and abrupt vessel closure. However, currently available stents either lack flexibility, hindering navigation through tortuous arteries, or lack axial strength, resulting in suboptimal scaffolding of the vessel. The unique transforming multicellular design of the NIR stent appears to provide both longitudinal flexibility and radial strength. Methods. NIR stent implantation was attempted in 255 patients (341 lesions) enrolled prospectively in a multicenter international registry from December 1995 through March 1996. Nine-, 16- and 32-mm long NIR stents were manually crimped onto coronary balloons and deployed in native coronary (94%) and saphenous vein graft (6%) lesions. Seventy-four percent of patients underwent elective stenting for primary or restenotic lesions, 21% for a suboptimal angioplasty result and 5% for threatened or abrupt vessel closure. Fifty-two percent of patients presented with unstable angina, 48% had a previous myocardial infarction, and 45% had multivessel disease. Coronary lesions were frequently complex, occurring in relatively small arteries (mean [±SD] reference diameter 2.8 ± 0.6 mm). Patients were followed up for 6 months for the occurrence of major adverse cardiovascular events. Results. Stent deployment was accomplished in 98% of lesions. Mean minimal lumen diameter increased by 1.51 ± 0.51 mm (from 1.09 ± 0.43 mm before to 2.60 ± 0.50 mm after the procedure). Mean percent diameter stenosis decreased from 61 ± 13% before to 17 ± 7% after intervention. A successful interventional procedure with <50% diameter stenosis of all treatment site lesions and no major adverse cardiac events within 30 days occurred in 95% of patients. Event-free survival at 6 months was 82%. Ninety-four percent of surviving patients were either asymptomatic or had mild stable angina at 6 month follow-up. Conclusions. Despite unfavorable clinical and angiographic characteristics of the majority of patients enrolled, the acute angiographic results and early clinical outcome after NIR stent deployment were very promising. A prospective, randomized trial comparing the NIR stent with other currently available stents appears warranted

Historical perspectives on pastoralism and land tenure transformation in Ngamiland, Botswana: What are the policy and institutional lessons?

Pastoral societies in dryland Africa continue to face changes to their pastoral systems. These systems are influenced by a range of historical factors but little use is made of this information to design policies that suit pastoralists’ landscapes. This article provides a synthesis of historical perspectives on pastoral land use and tenure transformations in Ngamiland, south of the Okavango Delta, Botswana. Little documentation of herders’ historical perspectives exists and less is known about how past experiences can be applied to sustainable pastoralism policies. In this article, current land use pressing issues are examined and analysed within the context of past experiences. We use a series of oral histories with key informants, focus group discussions, expert interviews and rangelands field observations. Ngamiland historical perspectives depict a pastoral landscape that has been shaped by a variety of factors; livestock diseases, Human-wildlife-conflicts, droughts, land tenure transformations associated with rangeland policies and the pastoral identity of the Ovaherero/Ovambanderu ethnic groups. Pastoralists have followed unique trajectories, specific to their rangeland conditions and socio-cultural context. Resilience to climate shocks and diseases has been weakened by inequitable patterns of control over rangeland resources. We recommend institutional diversity such that from experiences of the past, lessons can be drawn of the sort of processes and institutions required for pastoralism policies including targeted pastoralists’ adaptations. Using pastoralists to provide information, especially in the area of indigenous knowledge, strategies can be developed to link conservation of wildlife and rangelands with pastoral production by developing ecologically-sensitive low-volume tourism that pastoral communities can tap in to diversify their livelihoods

Taxonomy and structure of the Romanian personality lexicon

We identified 1746 personality-relevant trait-adjectives in a Romanian dictionary, of which 412 were classified as descriptors of dispositions by 10 judges. Self-ratings were collected from 515 participants on those 412 adjectives, and the ratings were factored using principal components analysis. Solutions with different numbers of factors were analysed. The two- and three-factor solutions, respectively, confirmed the Big Two and Big Three of personality traits. A five-factor solution reflected the Big Five model with a fifth factor emphasising Rebelliousness versus Conventionality. The five-factor solution was related to the International Personality Item Pool-Big Five scales, and the highest correlations were indeed between the corresponding factors and scales. A six-factor solution was indicative of the six-factor model as expressed in the HEXACO model, yet with a weak Honesty-Humility factor. Additional analysis with self-ratings from 218 participants on marker-scales for the six-factor solution and on the six scales of the HEXACO did not produce a clear one-to-one correspondence between the two sets of scales, confirming indeed that the six-factor model was only partially found

Conflicted Emotions Following Trust-based Interaction

We investigated whether 20 emotional states, reported by 170 participants after participating in a Trust game, were experienced in a patterned way predicted by the “Recalibrational Model” or Valence Models. According to the Recalibrational Model, new information about trust-based interaction outcomes triggers specific sets of emotions. Unlike Valence Models that predict reports of large sets of either positive or negative emotional states, the Recalibrational Model predicts the possibility of conflicted (concurrent positive and negative) emotional states. Consistent with the Recalibrational Model, we observed reports of conflicted emotional states activated after interactions where trust was demonstrated but trustworthiness was not. We discuss the implications of having conflicted goals and conflicted emotional states for both scientific and well-being pursuits