Modeling of Qiandao Lake submerged floating tunnel subject to multi-support seismic input

Abstract The modeling and seismic analysis of Qiandao lake submerged floating tunnel (SFT) is addressed with particular attention to the mooring system, to dissipation issues and to the spatial variability of the excitation, within a numerical procedure developed by the research group to perform the step-by-step dynamic analysis of discretized non-linear structural systems. The procedure, which can handle arbitrary external loading allowing for multiple-support seismic excitation, is enhanced by enriching the mooring cables model adding non-linear hydrodynamic loads. Different dissipation models account for hydrodynamic damping, structural damping and radiation damping which are included, respectively, as non-linear forces, as linear viscous damping equivalent to linear hysteretic by means of an iterative procedure, and as linear viscous damping. A possible solution is here studied to define an adequate cable discretization in order to correctly model nonlinear geometric effects and to avoid fictitious compressions. A uniformly modulated random process, whose spatial variability is governed by a single coherency function, is deemed adequate to model multi-support seismic input for the given structure. A novel method to obtain response spectrum compatible accelerograms is here proposed

The role of customer loyalty as a brand extension purchase predictor

The paper explores the relationship between customer loyalty to the retail brand and the purchase of non-traditional products and services (NTPS) offered by grocery retailers with their private label (i.e. over-the-counter products, photo printing, mobile communication services and travel booking). Customer loyalty to the retail brand is measured through its behavioral and attitudinal components. A survey was conducted administering a questionnaire to 480 retail customers in two stores belonging to different retail grocers. A binary logistic regression was then applied using the buying of at least one NTPS as the dependent variable (1 = buy; 0 = no buy) and behavioral loyalty and attitudinal loyalty as independent variables. Results show that attitudinal loyalty plays a significant role as buying predictor, but this depends on the NTPS offered. Theoretical and managerial implications are derived

MADAM: Effective and Efficient Behavior-based Android Malware Detection and Prevention

Android users are constantly threatened by an increasing number of malicious applications (apps), generically called malware. Malware constitutes a serious threat to user privacy, money, device and file integrity. In this paper we note that, by studying their actions, we can classify malware into a small number of behavioral classes, each of which performs a limited set of misbehaviors that characterize them. These misbehaviors can be defined by monitoring features belonging to different Android levels. In this paper we present MADAM, a novel host-based malware detection system for Android devices which simultaneously analyzes and correlates features at four levels: kernel, application, user and package, to detect and stop malicious behaviors. MADAM has been designed to take into account those behaviors characteristics of almost every real malware which can be found in the wild. MADAM detects and effectively blocks more than 96% of malicious apps, which come from three large datasets with about 2,800 apps, by exploiting the cooperation of two parallel classifiers and a behavioral signature-based detector. Extensive experiments, which also includes the analysis of a testbed of 9,804 genuine apps, have been conducted to show the low false alarm rate, the negligible performance overhead and limited battery consumption

A Framework for Probabilistic Contract Compliance

We propose PICARD (ProbabIlistic Contract on AndRoiD), a framework to detect repackaged applications for Android smartphones based upon probabilistic contract matching. A contract describes the sequences of actions that an application is allowed to perform at run-time, i.e. its legal behavior. In PICARD, contracts are generated from the set of traces that represent the usage profile of the application. Both the contract and the application\u27s run-time behavior are represented through clustered probabilistic automata. At run-time, a monitoring system verifies the compliance of the application trace with the contract. This approach is useful in detecting repackaged applications, whose behavior is strongly similar to the original application but it differs only from small paths in the traces. In this paper, we discuss the framework of PICARD for describing and generating contracts through probabilistic automata and introduce the notion of ActionNode, a cluster of related system calls. Then, we present a first set of results using a prototype implementation of PICARD for Android smartphones to prove the efficacy of the framework in detecting two classes of applications, repackaged and trojanized ones

Numerical study of compressor fouling mechanism based on Eulerian-Eulerian approach

AbstractThe paper describes a fluid dynamic numerical model to study the fouling mechanism for turbomachines (such as large gas turbines and small turbochargers). For this purpose, the gas-particle behaviour over a compressor blade is modelled using an open source CFD tool, OpenFOAM®. Through this model, two-fluid implicit equations system, with Eulerian-Eulerian approach is considered. This approach uses RANS turbulent models and also takes into account the particle fluid interactions. Applying Johnson-Kendal-Robert (JKR) theory, the particle deposition over the blade surface is predicted. According to the simulation results, there are certain regions which are facing the huge amount of deposition. The surfaces of these regions are prone to form an almost thick layer of sticked particles and affect the boundary layers and blade aerodynamics significantly. In order to capture this effect, a model to predict the deformation of the boundary with respect to deposition rate is also introduced

A Multi-Criteria-Based Evaluation of Android Applications

Android users can face the risk of downloading and installing bad applications on their devices. In fact, many applications may either hide malware, or their expected behavior do not fully follow the user\u27s expectation. This happens because, at install-time, even if the user is warned with the potential security threat of the application, she often skips this alert message. On Android this is due to the complexity of the permission system, which may be tricky to fully understand. We propose a multi-criteria evaluation of Android applications, to help the user to easily understand the trustworthiness degree of an application, both from a security and a functional side. We validate our approach by testing it on more than 180 real applications found either on official and unofficial markets

Sustainable Retrofitting Solutions: Evaluating the Performance of Jute Fiber Nets and Composite Mortar in Natural Fiber Textile Reinforced Mortars

Sustainable building materials for integrated (structural and thermal) retrofitting are the need of the hour to retrofit/upgrade the seismic vulnerable and ill-insulated existing building stocks. At the same time, the use of natural fibers and their recyclability could help construct safer and more sustainable buildings. This paper presents three aspects of jute fiber products: (1) the evaluation of the mechanical performance of the jute nets (2.5 cm × 2.5 cm and 2.5 cm and 1.25 cm mesh configurations) through tensile strength tests (with the aim for these to be used in upgrading masonry wall with natural fiber textile reinforced mortars (NFTRM) systems); (2) the hundred percentage recyclability of left-over jute fibers (collected during the net fabrication and failed nets post-tensile strength tests) for the composite mortar preparation; (3) and the evaluation of insulation capacity of the recycled jute net fiber composite mortar (RJNFCM) through thermal conductivity (TC) measurements, when a maximum amount of 12.5% of recycled jute fiber could be added in the mortar mixture at laboratory conditions and with available instruments Notably, when more than the said amount was used, the fiber–mortar bonding was found to be not optimal for the composite mortar preparation. These studies have been carried out considering these products’ applicability for integrated retrofitting purposes. It has been found that the denser mesh configuration (2.5 cm × 1.25 cm) is 35.80% stiffer than the other net configurations (2.5 cm × 2.5 cm). Also, the mesh configuration (2.5 cm × 1.25 cm) shows about 60% more capability to absorb strain energy. TC tests have demonstrated the moderate insulation capacity of these composite mortar samples, and the TC values obtained from the tests range from 0.110 (W/mK) to 0.121 (W/mK)

Risk analysis of Android applications: A user-centric solution

Android applications (apps) pose many risks to their users, e.g., by including code that may threaten user privacy or system integrity. Most of the current security countermeasures for detecting dangerous apps show some weaknesses, mainly related to users' understanding and acceptance. Hence, users would benefit from an effective but simple technique that indicates whether an app is safe or risky to be installed. In this paper, we present MAETROID (Multi-criteria App Evaluator of TRust for AndrOID), a framework to evaluate the trustworthiness of Android apps, i.e., the amount of risk they pose to users, e.g., in terms of confidentiality and integrity. MAETROID performs a multi-criteria analysis of an app at deploy-time and returns a single easy-to-understand evaluation of the app's risk level (i.e., Trusted, Medium Risk, and High Risk), aimed at driving the user decision on whether or not installing a new app. The criteria include the set of requested permissions and a set of metadata retrieved from the marketplace, denoting the app quality and popularity. We have tested MAETROID on a set of 11,000 apps both coming from Google Play and from a database of known malicious apps. The results show a good accuracy in both identifying the malicious apps and in terms of false positive rate

L\u2019impatto del sisma 2012 in Emilia sulle imprese commerciali: primi risultati e riflessioni

L\u2019articolo presenta i primi risultati emersi da un pi\uf9 ampio lavoro di ricerca volto ad esaminare l\u2019impatto che il terremoto del 2012 ha prodotto sulle attivit\ue0 commerciali della bassa emiliana e le reazioni di tali imprese all\u2019evento critico in un\u2019ottica di dynamic capabilities. Nello specifico, nel presente articolo si presenter\ue0 una sintesi dei risultati preliminari emersi dall\u2019analisi esplorativa svolta tramite focus group e interviste semi-strutturate a un campione di dettaglianti colpiti dal sisma. Si tratta di temi che la letteratura corrente non ha affrontato in modo sistematico ed adeguato in condizioni di criticit\ue0, soprattutto con riferimento al contesto della distribuzione al dettaglio

Human cytochrome P450 2B6 genetic variability in Botswana: a case of haplotype diversity and convergent phenotypes

Identification of inter-individual variability for drug metabolism through cytochrome P450 2B6 (CYP2B6) enzyme is important for understanding the di erences in clinical responses to malaria and HIV. This study evaluates the distribution of CYP2B6 alleles, haplotypes and inferred metabolic phenotypes among subjects with di erent ethnicity in Botswana. A total of 570 subjects were analyzed for CYP2B6 polymorphisms at position 516G>T (rs3745274), 785A>G (rs2279343) and 983T>C (rs28399499). Samples were collected in three districts of Botswana where the population belongs to Bantu (Serowe/Palapye and Chobe) and San-related (Ghanzi) ethnicity. The three districts showed di erent haplotype composition according to the ethnic background but similar metabolic inferred phenotypes, with 59.12%, 34.56%, 2.10% and 4.21% of the subjects having, respectively, an extensive, intermediate, slow and rapid metabolic pro le. The results hint at the possibility of a convergent adaptation of detoxifying metabolic phenotypes despite a di erent haplotype structure due to the di erent genetic background. The main implication is that, while there is substantial homogeneity of metabolic inferred phenotypes among the country, the response to drugs metabolized via CYP2B6 could be individually associated to an increased risk of treatment failure and toxicity. These are important facts since Botswana is facing malaria elimination and a very high HIV prevalence