Timed k-Tail: Automatic Inference of Timed Automata

Accurate and up-to-date models describing the be- havior of software systems are seldom available in practice. To address this issue, software engineers may use specification mining techniques, which can automatically derive models that capture the behavior of the system under analysis. So far, most specification mining techniques focused on the functional behavior of the systems, with specific emphasis on models that represent the ordering of operations, such as tempo- ral rules and finite state models. Although useful, these models are inherently partial. For instance, they miss the timing behavior, which is extremely relevant for many classes of systems and com- ponents, such as shared libraries and user-driven applications. Mining specifications that include both the functional and the timing aspects can improve the applicability of many testing and analysis solutions. This paper addresses this challenge by presenting the Timed k-Tail (TkT) specification mining technique that can mine timed automata from program traces. Since timed automata can effectively represent the interplay between the functional and the timing behavior of a system, TkT could be exploited in those contexts where time-related information is relevant. Our empirical evaluation shows that TkT can efficiently and effectively mine accurate models. The mined models have been used to identify executions with anomalous timing. The evaluation shows that most of the anomalous executions have been correctly identified while producing few false positives

Family Succession and Firm Performance: Evidence from Italian Family Firms

This article contributes to the growing empirical literature on family firms by studying the impact of the founder–chief executive officer (CEO) succession in a sample of Italian firms. We contrast firms that continue to be managed within the family by the heirs to the founders with firms in which the management is passed on to outsiders. Family successions, that is, successions by the founder’s heirs, are further analyzed by assessing the impact of the sectoral intensity of competition on the post-succession performance. This analysis also addresses the endogeneity in the timing of the CEO succession by controlling for a pure mean-reversion effect in the firm’s performance. We find that the maintenance of management within the family has a negative impact on the firm’s performance, and this effect is largely borne by the good performers, especially in the more competitive sectors. These results indicate that there is no inherent superiority of the family-firm structure and emphasize the importance of conducting an analysis of governance in a variety of institutional settings.Family successions; Family firms; Founder-run firms

Dynamic macroeconomic effects of public capital: evidence from regional Italian data

This paper assesses the effects of public capital in Italy on the main macroeconomic aggregates: GDP, private capital and labour. A cointegrated vector autoregressive (VAR) model, in line with recent advancements in the field, allows us to take into account the complex nexus of direct and indirect links between the variables. We find a persistent increase in GDP in response to a positive shock to public capital; this result is mainly attributable to a strong stimulus exerted by public infrastructures on private capital (crowding in). The positive effects of public capital are quite pervasive across Italy, albeit to differing extents. In particular, a higher elasticity of GDP to public capital is estimated for the South, whereas marginal productivity turns out to be higher in the Centre-North. This suggests that public capital has a lower economic return in the South, bearing out the existence of a potential conflict between equity and efficiency goals. Finally, we indirectly document the existence of positive spillover effects at the regional level, allowing individual regions to benefit from the endowment of public capital in the rest of the country.public capital, crowding in effects, Italian regional divides, VAR models

Policy Enforcement with Proactive Libraries

Software libraries implement APIs that deliver reusable functionalities. To correctly use these functionalities, software applications must satisfy certain correctness policies, for instance policies about the order some API methods can be invoked and about the values that can be used for the parameters. If these policies are violated, applications may produce misbehaviors and failures at runtime. Although this problem is general, applications that incorrectly use API methods are more frequent in certain contexts. For instance, Android provides a rich and rapidly evolving set of APIs that might be used incorrectly by app developers who often implement and publish faulty apps in the marketplaces. To mitigate this problem, we introduce the novel notion of proactive library, which augments classic libraries with the capability of proactively detecting and healing misuses at run- time. Proactive libraries blend libraries with multiple proactive modules that collect data, check the correctness policies of the libraries, and heal executions as soon as the violation of a correctness policy is detected. The proactive modules can be activated or deactivated at runtime by the users and can be implemented without requiring any change to the original library and any knowledge about the applications that may use the library. We evaluated proactive libraries in the context of the Android ecosystem. Results show that proactive libraries can automati- cally overcome several problems related to bad resource usage at the cost of a small overhead.Comment: O. Riganelli, D. Micucci and L. Mariani, "Policy Enforcement with Proactive Libraries" 2017 IEEE/ACM 12th International Symposium on Software Engineering for Adaptive and Self-Managing Systems (SEAMS), Buenos Aires, Argentina, 2017, pp. 182-19

BDCI: Behavioral Driven Conflict Identification

Source Code Management (SCM) systems support software evolution by providing features, such as version control, branching, and conflict detection. Despite the presence of these features, support to parallel software development is often limited. SCM systems can only address a subset of the conflicts that might be introduced by developers when concurrently working on multiple parallel branches. In fact, SCM systems can detect textual conflicts, which are generated by the concurrent modification of the same program locations, but they are unable to detect higher-order conflicts, which are generated by the concurrent modification of different program locations that generate program misbehaviors once merged. Higher-order conflicts are painful to detect and expensive to fix because they might be originated by the interference of apparently unrelated changes. In this paper we present Behavioral Driven Conflict Identification (BDCI), a novel approach to conflict detection. BDCI moves the analysis of conflicts from the source code level to the level of program behavior by generating and comparing behavioral models. The analysis based on behavioral models can reveal interfering changes as soon as they are introduced in the SCM system, even if they do not introduce any textual conflict. To evaluate the effectiveness and the cost of the proposed approach, we developed BDCIf , a specific instance of BDCI dedicated to the detection of higher-order conflicts related to the functional behavior of a program. The evidence collected by analyzing multiple versions of Git and Redis suggests that BDCIf can effectively detect higher-order conflicts and report how changes might interfere

Hypofractionated high-dose radiation therapy for prostate cancer with intensity-modulated and image-guided radiotherapy (IMRT-IGRT)

Obiettivo: valutare la tossicità ed il controllo di malattia di un trattamento radioterapico ipofrazionato ad alte dosi con tecnica ad intensità modulata (IMRT) guidata dalle immagini (IGRT) in pazienti affetti da carcinoma prostatico a rischio intermedio, alto ed altissimo di recidiva. Materiali e metodi: tutti i pazienti candidati al trattamento sono stati stadiati e sottoposti al posizionamento di tre “markers” fiduciali intraprostatici necessari per l’IGRT. Mediante tecnica SIB – IMRT sono stati erogati alla prostata 67,50 Gy in 25 frazioni (EQD2 = 81 Gy), alle vescichette 56,25 Gy in 25 frazioni (EQD2 = 60,35 Gy) e ai linfonodi pelvici, qualora irradiati, 50 Gy in 25 frazioni. La tossicità gastrointestinale (GI) e genitourinaria (GU) è stata valutata mediante i CTCAE v. 4.03. Per individuare una possibile correlazione tra i potenziali fattori di rischio e la tossicità registrata è stato utilizzato il test esatto di Fisher e la sopravvivenza libera da malattia è stata calcolata mediante il metodo di Kaplan-Meier. Risultati: sono stati arruolati 71 pazienti. Il follow up medio è di 19 mesi (3-35 mesi). Nessun paziente ha dovuto interrompere il trattamento per la tossicità acuta. Il 14% dei pazienti (10 casi) ha presentato una tossicità acuta GI G ≥ 2 e il 15% (11 pazienti) ha riportato una tossicità acuta GU G2. Per quanto riguarda la tossicità tardiva GI e GU G ≥ 2, essa è stata documentata, rispettivamente, nel 14% dei casi (9 pazienti) e nell’11% (7 pazienti). Non è stata riscontrata nessuna tossicità, acuta o cronica, G4. Nessun fattore di rischio correlava con la tossicità. La sopravvivenza libera da malattia a 2 anni è del 94%. Conclusioni: il trattamento radioterapico ipofrazionato ad alte dosi con IMRT-IGRT appare essere sicuro ed efficace. Sono comunque necessari ulteriori studi per confermare questi dati ed i presupposti radiobiologici dell’ipofrazionamento del carcinoma prostatico.Purpose: to evaluate toxicity and control of disease with hypofractionated high-dose intensity-modulated (IMRT) and image guided (IGRT) radiotherapy in patients with intermediate, high and very high risk of prostate cancer. Materials and Methods: patients eligible for treatment were staged and three fiducial "markers" needed for IGRT were implanted in the prostate. It was delivering with SIB- IMRT 67,50 Gy in 25 fractions (EQD2 = 81 Gy) to the prostate, 56,25 Gy in 25 fractions (EQD2 = 60,35 Gy) to the seminal vesicles and 50 Gy in 25 fractions to the pelvic lymph nodes, when irradiated. Gastrointestinal (GI) and genitourinary (GU) toxicity were assessed using CTCAE v. 4.03. Correlation between potential risk factors and toxicity was performed using the Fisher's test and disease-free survival was calculated using the Kaplan-Meier method. Results: seventy-one patients were evaluated. The mean follow-up was 19 months (3-35 months). No patient had to discontinue treatment for acute toxicity. 14% of patients (10 cases) presented acute GI G ≥ 2 and 15% (11 patients) reported acute toxicity GU G2. Regarding the late toxicity GI and GU G ≥ 2, it has been detected, respectively, in 14% (9 patients) and 11% of cases (7 patients). There was no incidence of any acute or late toxicity G4. No risk factor correlated with toxicity. The disease-free survival at 2 years was 94%. Conclusions: hypofractionated high-dose IMRT-IGRT radiotherapy appears to be safe and effective. However, further studies are needed to confirm these data and the radiobiological bases of hypofractionated radiotherapy of prostate cancer

The producer service sector in Italy: Long-term growth and its local determinants

This paper analyses the local determinants of producer service growth in Italy, focusing on agglomeration economies, and taking into account the particular features of this sector with respect to manufacturing. Using an OECD classification, we estimate a dynamic specification allowing for transitory dynamics around the long-run employment path derived from a model in which both demand and supply factors are considered. Compared with the prevailing modelling approach, the spatial scope of externalities is extended to include possible interactions across different urban areas. Our main findings are the following. Long-run employment growth is positively affected by Marshall-Arrow-Romer externalities, with a minor role played by urbanization externalities, a result similar to that obtained by more recent research on the Italian manufacturing sector and its industrial districts. Among the remaining supply factors, human capital exerts a positive influence on the long-run employment level in producer services industry; among demand factors, the size of the local market appears to be important, given the still incomplete tradability of service output. Significant interactions across urban areas are shown to occur; in particular, positive knowledge externalities on local productivity appear to be induced by location in urban areas contiguous to cities specializing in producer services.agglomeration economies, human capital, producer services