Script Code Research Articles

Lucretia — intersection type polymorphism for scripting languages

Scripting code may present maintenance problems in the long run. There is, then, the call for methodologies that make it possible to control the properties of programs written in dynamic languages in an automatic fashion. We introduce Lucretia, a core language with an introspection primitive. Lucretia is equipped with a (retrofitted) static type system based on local updates of types that describe the structure of objects being used. In this way, we deal with one of the most dynamic features of scripting languages, that is, the runtime modification of object interfaces. Judgements in our systems have a Hoare-like shape, as they have a precondition and a postcondition part. Preconditions describe static approximations of the interfaces of visible objects before a certain expression has been executed and postconditions describe them after its execution. The field update operation complicates the issue of aliasing in the system. We cope with it by introducing intersection types in method signatures.

Thermodynamic description of the systems Co–Nb, Al–Nb and Co–Al–Nb

The Co–Al–Nb ternary system and its two binary subsystems Co–Nb and Al–Nb were thermodynamically modeled by the Calphad method based on own experimental results and critically assessed literature data. A characteristic of the Co–Nb and Co–Al–Nb system is the coexistence of three polytypes of Laves phases: hexagonal C14 and C36 as well as cubic C15. Two-sublattice models were used for the three Laves phases to enable a realistic description of their homogeneity ranges in the Co–Nb and Co–Al–Nb system. A re-assessment was needed for the Al–Nb system to obtain a better description of the homogeneity range of Nb2Al and the liquidus projection of the Co–Al–Nb system. The comparison between calculated and experimental values shows that the optimized set of thermodynamic parameters gives a very good description of most of the experimental data resulting in a complete, consistent thermodynamic description of the three systems Co–Nb, Al–Nb and Co–Al–Nb.

Fracture mechanics of planetary gear set by using extended finite element method-linear elastic fracture mechanics approach

Contour integral method is the conventional approach in order to characterise main crack parameters in fracture studies. This method is used in verity fields in fractures mechanics because of its capability in linear and non-linear fracture mechanics. Whereas, requirements such as mesh singularity in crack tip and refined layers of elements in surrounding contours, which increase computing time and make it prolix for large components. The main aim of this paper is to develop an extended finite element method-linear elastic fracture mechanics (XFEM-LEFM) model to impart XFEM advantages in survey of fracture mechanics of planetary gear sets. At first main crack parameters of root crack of the planet gear have been obtained and compared with conventional method, and after that crack growth path is predicted, and finally effect of rim thickness is investigated and compared with other researches to illustrate the efficiency of the developed model. For this purpose, Python script code is generated to automatically calculate the stress intensity factors of root crack and after that simulate the crack growth path until final fracture.

Design and Construction of Distributed JavaScript Parsing System

With the rapid development of the Internet technology, JS (short for JavaScript), as one of the representative of script languages, which is very powerful, is becoming more and more popular to the developers and users. But JS programming is more complex than usual static technology. In the field of search engine and information acquisition, it's very difficult to get the information hidden in script code. In this paper, the authors design a distributed system for parsing the JS code embedded in HTML file and retrieving the underling information. the authors describe how to extract JS codes from HTML file and parse them. Also, they introduce a task scheduling algorithm for the JS parsing system by employing Hadoop distributed computing technology. The experimental results indicate that the proposed algorithm and system can achieve a reasonable task scheduling efficiency and parse JS codes rapidly.

Design and Realization of Universal Integrated Testing Platform for Equipment-Embedded Software

An universal testing platform for equipment-embedded software is designed and realized to support the dynamic verification test of embedded software on CI level and system level. This Platform, based on LAN and USB bus architecture, has provided the function of system interface modelling, test project management, test case script code, test result control and analysis, and test report generation, and is available for real time, closed-loop and non-invasive dynamic testing on the embedded software with the characteristic of portability, easy operation, flexibility in size configuration and universality of protocol description.

A likelihood-based biostatistical model for analyzing consumer movement in simultaneous choice experiments.

Consumer feeding preference among resource choices has critical implications for basic ecological and evolutionary processes, and can be highly relevant to applied problems such as ecological risk assessment and invasion biology. Within consumer choice experiments, also known as feeding preference or cafeteria experiments, measures of relative consumption and measures of consumer movement can provide distinct and complementary insights into the strength, causes, and consequences of preference. Despite the distinct value of inferring preference from measures of consumer movement, rigorous and biologically relevant analytical methods are lacking. We describe a simple, likelihood-based, biostatistical model for analyzing the transient dynamics of consumer movement in a paired-choice experiment. With experimental data consisting of repeated discrete measures of consumer location, the model can be used to estimate constant consumer attraction and leaving rates for two food choices, and differences in choice-specific attraction and leaving rates can be tested using model selection. The model enables calculation of transient and equilibrial probabilities of consumer-resource association, which could be incorporated into larger scale movement models. We explore the effect of experimental design on parameter estimation through stochastic simulation and describe methods to check that data meet model assumptions. Using a dataset of modest sample size, we illustrate the use of the model to draw inferences on consumer preference as well as underlying behavioral mechanisms. Finally, we include a user's guide and computer code scripts in R to facilitate use of the model by other researchers.

Conceptual independence: A design principle for the construction of adaptive information systems

This paper examines the problem of conceptual dependence, the coupling of software applications׳ internal structures and logic with their underlying conceptual models. Although conceptual dependence is almost universal in information system design, it produces a range of unintended negative consequences including system inflexibility and increased maintenance costs. Many information systems contain components, such as database tables and classes, whose design reflects the entity types and relationships in underlying, domain-oriented conceptual models. When the models change, work is involved in altering the software components. For example, an e-commerce system might include tables and classes representing product types, customers and orders, with associated code in methods, stored procedures and other scripts. The structure of the entity types and their relationships will be implicit in the tables, classes and code, coupling the system to its conceptual model. Any change to the model (such as the introduction of a new entity type, representing order lines) invalidates existing structures and code, causing rework. In large systems, this rework can be time-consuming and expensive. Research shows that schema change is common, and that it contributes significantly to the high cost of software maintenance. We argue that much of the cost may be avoidable if alternative design strategies are used. The paper describes an alternative design approach based on the principle of conceptual independence, which can be used to produce adaptive information systems (AIS). It decouples the internal structures and logic of information systems from the domain-specific entity types and relationships in the conceptual models they implement. An architecture for AIS is presented which includes soft schemas (conceptual models stored as data), an end-user conceptual modelling tool, a set of archetypal categories (predefined semantic categories), and an adaptive data model which allows data to be stored without conceptual dependence. The archetypal categories allow domain-specific run time behaviour to be provided, despite the absence of domain-specific software structure and logic. An advantage of AIS over conventionally-designed applications is that each AIS can be used in a wide variety of domains. AIS offer the prospect of significantly reduced maintenance costs, as well as increased scope for the development and modification of systems by end users. Work to date on implementation of the AIS architecture is discussed, and an agenda for future research is outlined including development and evaluation of a fully-featured AIS. The paper discusses challenges to be overcome and barriers to adoption.

Web Application Security

In today's world, web applications are used for sharing information and servicing delivery over the Internet. As their use is increasing day by day for critical services, web applications become a popular and valuable target for security attacks. Although a large number of techniques have been developed to fortify web applications and mitigate the attacks towards web applications, there is little effort devoted to drawing connections among these techniques and building a big picture of web application security research. Web applications are important, common distributed systems whose current security relies primarily on server-side mechanisms. Web applications provide access to server functionality through a set of web pages to the end users. These pages often contain script code to be executed dynamically within the client web browser. Most web applications aim to enforce simple, intuitive security policies, such as, for web-based email, disallowing any scripts in entrusted email messages. Even so, web applications are currently subject to a plethora of successful attacks, such as cross-site scripting, cookie theft, session riding, browser hijacking and the recent self-propagating worms in web-based email and social networking sites. This paper makes the end-to-end argument that the client and server must collaborate to achieve security goals, to eliminate common security exploits and to secure the emerging class of rich, cross-domain web applications referred to as Web 2.0.

Thermodynamic optimization of Co–Ge binary system

Phase diagram of Co–Ge binary system was thermodynamically assessed by using CALPHAD approach in this study. The excess Gibbs energy of the solution phases, liquid, α(Co) and ɛ(Co), were modeled with Redlich–Kister polynomial. Magnetic contribution to the Gibbs energy was also taken into account for α(Co) and ɛ(Co). Considering its crystal structure and solubility range, the intermetallic compound βCo5Ge3, with B82-structure, was particularly described with a three-sublattice model, (Co,Va)1:(Co)4:(Co,Ge)3. And the compound CoGe was described with two-sublattice model according to its crystal structure. Other intermetallic compounds were described as stoichiometric phases because of their narrow homogeneity ranges or unknown crystal structure. In order to obtain a reasonable description of several Co–Ge compounds, first-principle calculations were performed before optimization to determine their formation enthalpies. Finally, a set of thermodynamic parameters was finally obtained so that most data of phase boundaries and thermodynamic properties of various phases were reproduced in present optimization.

Use of infrared spectroscopy and density functional theory to study the influence of rubidium on alumina-supported molybdenum carbide catalyst for higher alcohol synthesis from syngas

Molybdenum carbide nanoclusters supported on alumina were promoted by Rb2CO3 and tested for higher alcohol synthesis from syngas. At 573K and 30bar syngas (H2/CO=1), the promoted catalyst demonstrated 63% selectivity to alcohols (on a CO2-free basis), with hydrocarbons and ethers as side products. In contrast, the alcohol selectivity of an unpromoted Mo2C/Al2O3 catalyst was very low. DRIFTS of adsorbed CO on Mo2C/Al2O3 revealed a significant red shift in the CO band with added Rb promoter, which correlated to a decrease in hydrocarbon production rate and therefore an increase in alcohol selectivity. A quantum chemical description of CO adsorbed on a model Mo2C surface identified several possible binding modes of the CO. Both reactivity studies and DRIFTS of adsorbed CO demonstrated that mobility of the Rb promoter was enhanced in the presence of water vapor, which facilitates dispersion of Rb across the catalyst surface and effectively neutralizes acid sites that are deleterious to alcohol selectivity.

Implementing artificial intelligence: a generic approach with software support

In computer games, one of the eminent trends is to create large virtual worlds with numerous non-player characters. Usually their artificial intelligence (AI) is implemented by scripting, which can be a burden for the application developers involved. This paper suggests an approach facilitating designing AI functionalities and striving to reduce, via software tool support, the amount of hand-written AI script code needed. Our approach is suitable for, e.g., creating autonomous agents with personal characteristics, capable of behaving in a natural manner. For instance, the goal-oriented agent paradigm can be applied easily with the approach. The definitions needed are written using a script language. Therefore, the agent configurations can be tested rapidly. We have extended an existing AI environment and created a script framework for implementing general-purpose AIs. Moreover, we have implemented software tools capable of generating script code for helping in the AI structure design and for simplifying the actual code-writing task. For demonstrating the applicability of our approach, three example scenarios specialized from the framework are presented.

Unicode Applications in the Digital Libraries of India

The digitisation of documents content and metadata of other than English language works is gaining importance as the need for multilingual access and retrieval is increasing all over the world, including India. This paper discusses the technical issues relating to UNICODE applications in digital libraries. The special emphasis is laid on standard codes especially for Indian languages although it has touched other languages like Thai, Hebrew etc. ASCII (The American Standard Code for Information Interchange) and ISCII (Indian Script Code for Information Interchange) are briefly mentioned. It has stressed on Unicode collation algorithm (UCA) as “a customizable method to compare two strings”. Finally, it has touched activities of digital libraries in an Indian environment.

An Approach to Detect Similar Script Functions in Web Applications Based on Calling Information

Cloned code might exacerbate a system maintenance problem, so it is important to remove duplicate code to improve system performance. In web development, script code can often be duplicated as a unit of a script function. Previous research for detecting similar script functions forecasted candidates of similar script functions based on the name of the function and classified the detected candidates into four similarity levels by comparing factors contained within the script functions. There are two key issues that need to be considered to detect similar script functions when using that method. One was that a pair of similar script functions needs to have the same name to be detected. The other was that some modifications particularly such as adding or removing calling statements were not identified after detecting. Adding or removing calling statements might prevent identification for duplicate script function. In this paper, we propose a novel approach to detect similar script functions that can determine the similarity of a script function by evaluating the structural similarity of function code and the calling structure. The evaluation for detecting the structural similarity of code and the calling structure is performed based on a similarity metric, FSIM, which we have defined. We showed the usefulness of FSIM by applying it to three open source projects.

Life's code script does not code itself

Biology faces the challenge of integrating a deluge of empirical information about living systems into a theoretical framework. However, popular analogies with machines or computers are misguided and do not reflect the true nature of biological systems.

CompASM: an Amber-VMD alanine scanning mutagenesis plug-in

Alanine scanning mutagenesis (ASM) of protein–protein interfacial residues is a popular means to understand the structural and energetic characteristics of hot spots in protein complexes. In this work, we present a computational approach that allows performing such type of analysis based on the molecular mechanics/Poisson– Boltzmann surface area method. This computational approach has been used largely in the past and has proven to give reliable results in a wide range of complexes. However, the sequential preparation and manual submission of dozens of files has been often a major obstacle in using it. To overcome these limitations and turn this approach user-friendly, we have designed the plug-in CompASM (computational alanine scanning mutagenesis). This software has an easy-to-use graphical interface to prepare the input files, run the calculations, and analyze the final results. CompASM was built in TCL/TK programming language to be included in VMD as a plug-in. The CompASM package is distributed as an independent platform, with script code under the GNU Public License from http://compbiochem.org/Software/compasm/Home.html.

Using Python for scientific computing: Efficient and flexible evaluation of the statistical characteristics of functions with multivariate random inputs

This paper examines the feasibility of high-level Python based utilities for numerically intensive applications via an example of a multidimensional integration for the evaluation of the statistical characteristics of a random variable. We discuss the approaches to the implementation of mathematically formulated incremental expressions using high-level scripting code and low-level compiled code. Due to the dynamic typing of the Python language, components of the algorithm can be easily coded in a generic way as algorithmic templates. Using the Enthought Development Suite they can be effectively assembled into a flexible computational framework that can be configured to execute the code for arbitrary combinations of integration schemes and versions of instantiated code. The paper describes the development cycle using a simple running example involving averaging of a random two-parametric function that includes discontinuity. This example is also used to compare the performance of the available algorithmic and executional features. The implemented package including further examples and the results of performance studies have been made available via the free repository [1] and CPCP library. Program summaryProgram title: spirridCatalogue identifier: AENL_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AENL_v1_0.htmlProgram obtainable from: CPC Program Library, Queen’s University, Belfast, N. IrelandLicensing provisions: Special licence provided by the authorNo. of lines in distributed program, including test data, etc.: 10722No. of bytes in distributed program, including test data, etc.: 157099Distribution format: tar.gzProgramming language: Python and C.Computer: PC.Operating system: LINUX, UNIX, Windows.Classification: 4.13, 6.2.External routines: NumPy (http://numpy.scipy.org/), SciPy (http://www.scipy.com)Nature of problem:Evaluation of the statistical moments of a function of random variables.Solution method:Direct multidimensional integration.Running time:Depending on the number of random variables the time needed for the numerical estimation of the mean value of a function with a sufficiently low level of numerical error varies. For orientation, the time needed for two includedexamples: examples/fiber_tt_2p/fiber_tt_2p.py with 2 randomvariables: few millisecondsexamples/fiber_po_8p/fiber_po_8p.py with 8 randomvariables: few seconds

원격코드검증을 통한 웹컨텐츠의 악성스크립트 탐지

최근 웹사이트는 매쉬업, 소셜 서비스 등으로 다양한 출처의 리소스를 상호 참조하는 형태로 변화하면서 해킹 시도도 사이트를 직접 공격하기보다 서비스 주체와 연계 서비스, 클라이언트가 상호 작용하는 접점에 악성스크립트를 삽입하는 공격이 증가하고 있다. 본 논문에서는 웹사이트 이용 시 신뢰관계에 있는 여러 출처로부터 다운받은 웹컨텐츠의 HTML 코드와 자바스크립트 코드가 클라이언트 브라우저에서 구동 시 삽입된 악성스크립트를 원격의 검증시스템으로부터 탐지하는 모델을 제안한다. 서비스 주체의 구현코드 정보를 활용하여 요청 출처에 따라 검증 항목을 분류하고 웹컨텐츠의 검증 요소를 추출하여 검증 평가결과를 화이트, 그레이, 블랙 리스트로 데이터베이스에 저장하였다. 실험평가를 통해 제안한 시스템이 악성스크립트를 효율적으로 탐지하여 클라이언트의 보안이 향상됨을 확인하였다. Sharing cross-site resources has been adopted by many recent websites in the forms of service-mashup and social network services. In this change, exploitation of the new vulnerabilities increases, which includes inserting malicious codes into the interaction points between clients and services instead of attacking the websites directly. In this paper, we present a system model to identify malicious script codes in the web contents by means of a remote verification while the web contents downloaded from multiple trusted origins are executed in a client's browser space. Our system classifies verification items according to the origin of request based on the information on the service code implementation and stores the verification results into three databases composed of white, gray, and black lists. Through the experimental evaluations, we have confirmed that our system provides clients with increased security by effectively detecting malicious scripts in the mashup web environment.

Detection of Cross Site Scripting Attack in Wireless Networks Using n-Gram and SVM

Large parts of attacks targeting the web are aiming at the weak point of web application. Even though SQL injection, which is the form of XSS (Cross Site Scripting) attacks, is not a threat to the system to operate the web site, it is very critical to the places that deal with the important information because sensitive information can be obtained and falsified. In this paper, the method to detect themalicious SQL injection script code which is the typical XSS attack using n-Gram indexing and SVM (Support Vector Machine) is proposed. In order to test the proposed method, the test was conducted after classifying each data set as normal code and malicious code, and the malicious script code was detected by applying index term generated by n-Gram and data set generated by code dictionary to SVM classifier. As a result, when the malicious script code detection was conducted using n-Gram index term and SVM, the superior performance could be identified in detecting malicious script and the more improved results than existing methods could be seen in the malicious script code detection recall.

BrowserGuard: A Behavior-Based Solution to Drive-by-Download Attacks

Along with an increasing user population of various web applications, browser-based drive-by-download attacks soon become one of the most common security threats to the cyber community. A user using a vulnerable browser or browser plug-ins may become a victim of a drive-by-download attack right after visiting a vicious web site. The end result of such attacks is that an attacker can download and execute any code on the victim's host. This paper proposes a runtime, behavior-based solution, BrowserGuard, to protect a browser against drive-by-download attacks. BrowserGuard records the download scenario of every file that is loaded into a host through a browser. Then based on the download scenario, BrowserGuard blocks the execution of any file that is loaded into a host without the consent of a browser user. Due to its behavior-based detection nature, BrowserGuard does not need to analyze the source file of any web page or the run-time states of any script code, such as Javascript. BrowserGuard also does not need to maintain any exploit code samples and does not need to query the reputation value of any web site. We utilize the standard BHO mechanism of Windows to implement BrowserGuard on IE 7.0. Experimental results show that BrowserGuard has low performance overhead (less than 2.5%) and no false positives and false negatives for the web pages used in our experiments.

Simple One-Center Model for Linear Molecules: Application to Carbon Dioxide

With computational efficacy in mind, a one-center model for linear molecules is heuristically sketched. When parametrized for CO(2), all parameters save for two are supplied from literature quantum chemistry calculation or, in one case, heuristic argument. Using the remaining two adjustable parameters, the mean unsigned relative errors (predicted/observed) over the temperature range 220-290 K are 4.7% for the energy of vaporization, 0.6% for the liquid, and 8.0% for the vapor coexistence densities, respectively. The critical temperature is estimated at T(c) = 308 K, the critical density at ρ(c) = 0.460 g/cm(3), and the critical pressure at p(c) = 8.26 ± 0.11 MPa. This order of accuracy is comparable to that of many all-atom potential descriptions of CO(2) but is obtained at roughly nine times the speed. When supplied with the experimental bond length, somewhat worse agreement with experiment is exhibited for the neutron-weighted atomic pair distribution function of the liquid. This disparity is tentatively attributed to an overestimated electrostatic quadrupole-quadrupole interaction relative to the other forces present.