Uma perspectiva de extensão do modelo de aceitação de tecnologia para explicar o uso de linguagens de desenvolvimento WEB: pesquisa com desenvolvedores Pyton e Java

The spread of the Web boosted the dissemination of Information Systems (IS) based on the Web. In order to support the implementation of these systems, several technologies came up or evolved with this purpose, namely the programming languages. The Technology Acceptance Model TAM (Davis, 1986) was conceived aiming to evaluate the acceptance/use of information technologies by their users. A lot of studies and many applications have used the TAM, however, in the literature it was not found a mention of the use of such model related to the use of programming languages. This study aims to investigate which factors influence the use of programming languages on the development of Web systems by their developers, applying an extension of the TAM, proposed in this work. To do so, a research was done with Web developers in two Yahoo groups: java-br and python-brasil, where 26 Java questionnaires and 39 Python questionnaires were fully answered. The questionnaire had general questions and questions which measured intrinsic and extrinsic factors of the programming languages, the perceived usefulness, the perceived ease of use, the attitude toward the using and the programming language use. Most of the respondents were men, graduate, between 20 and 30 years old, working in the southeast and south regions. The research was descriptive in the sense of its objectives. Statistical tools, descriptive statistics, main components and linear regression analysis were used for the data analysis. The foremost research results were: Java and Python have machine independence, extensibility, generality and reliability; Java and Python are more used by corporations and international organizations than supported by the government or educational institutions; there are more Java programmers than Python programmers; the perceived usefulness is influenced by the perceived ease of use; the generality and the extensibility are intrinsic factors of programming languages which influence the perceived ease of use; the perceived ease of use influences the attitude toward the using of the programming language

Jmodels: Java models of earth system regulation

The JModel suite consists of a number of models of aspects of the Earth System. They can all be run from the JModels website. They are written in the Java language for maximum portability, and are capable of running on most computing platforms including Windows, MacOS and Unix/Linux. The models are controlled via graphical user interfaces (GUI), so no knowledge of computer programming is required to run them. The models currently available from the JModels website are: Ocean phosphorus cycle Ocean nitrogen and phosphorus cycles Ocean silicon and phosphorus cycles Ocean and atmosphere carbon cycle Energy radiation balance model (under development) The main purpose of the models is to investigate how material and energy cycles of the Earth system are regulated and controlled by different feedbacks. While the central focus is on these feedbacks and Earth System stabilisation, the models can also be used in other ways. These resources have been developed by: National Oceanography Centre, Southampton project led by Toby Tyrrell and Andrew Yool, focus on how the Earth system works.

Use of Java Cards in a telematic voting system.

This paper presents a general view of the telematic voting system developed by its authors, with a special emphasis on the important role that smart cards play in this scenario. The use of smart cards as basic pieces for providing secure cryptographic operations in this type of voting scheme is justified. The differences and advantages of Java Cards in comparison with the ?classical? smart cards (those that completely conform to the ISO/IEC 7816 standard) are also discussed. As an example, the paper describes one of the applets implemented in the voting Java Card as part of the general telematic voting application.

Tool support for executable documentation of Java class hierarchies

While object-oriented programming offers great solutions for today's software developers, this success has created difficult problems in class documentation and testing. In Java, two tools provide assistance: Javadoc allows class interface documentation to be embedded as code comments and JUnit supports unit testing by providing assert constructs and a test framework. This paper describes JUnitDoc, an integration of Javadoc and JUnit, which provides better support for class documentation and testing. With JUnitDoc, test cases are embedded in Javadoc comments and used as both examples for documentation and test cases for quality assurance. JUnitDoc extracts the test cases for use in HTML files serving as class documentation and in JUnit drivers for class testing. To address the difficult problem of testing inheritance hierarchies, JUnitDoc provides a novel solution in the form of a parallel test hierarchy. A small controlled experiment compares the readability of JUnitDoc documentation to formal documentation written in Object-Z. Copyright (c) 2005 John Wiley & Sons, Ltd.

Lightweight Modeling of Java Virtual Machine Security Constraints using Alloy

The Java programming language has been widely described as secure by design. Nevertheless, a number of serious security vulnerabilities have been discovered in Java, particularly in the component known as the Bytecode Verifier. This paper describes a method for representing Java security constraints using the Alloy modeling language. It further describes a system for performing a security analysis on any block of Java bytecodes by converting the bytes into relation initializers in Alloy. Any counterexamples found by the Alloy analyzer correspond directly to insecure code. Analysis of a real-world malicious applet is given to demonstrate the efficacy of the approach.

Driving the refactoring of Java Enterprise applications by evaluating the distance between application elements

Java Enterprise Applications (JEAs) are complex systems composed using various technologies that in turn rely on languages other than Java, such as XML or SQL. Given the complexity of these applications, the need to reverse engineer them in order to support further development becomes critical. In this paper we show how it is possible to split a system into layers and how is possible to interpret the distance between application elements in order to support the refactoring of JEAs. The purpose of this paper is to explore ways to provide suggestions about the refactoring operations to perform on the code by evaluating the distance between layers and elements belonging those layers. We split JEAs into layers by considering the kinds and the purposes of the elements composing the application. We measure distance between elements by using the notion of the shortest path in a graph. Also we present how to enrich the interpretation of the distance value with enterprise pattern detection in order to refine the suggestion about modifications to perform on the code.

A large study on the effect of code obfuscation on the quality of java code

Context: Obfuscation is a common technique used to protect software against mali- cious reverse engineering. Obfuscators manipulate the source code to make it harder to analyze and more difficult to understand for the attacker. Although different ob- fuscation algorithms and implementations are available, they have never been directly compared in a large scale study. Aim: This paper aims at evaluating and quantifying the effect of several different obfuscation implementations (both open source and commercial), to help developers and project manager to decide which one could be adopted. Method: In this study we applied 44 obfuscations to 18 subject applications covering a total of 4 millions lines of code. The effectiveness of these source code obfuscations has been measured using 10 code metrics, considering modularity, size and complexity of code. Results: Results show that some of the considered obfuscations are effective in mak- ing code metrics change substantially from original to obfuscated code, although this change (called potency of the obfuscation) is different on different metrics. In the pa- per we recommend which obfuscations to select, given the security requirements of the software to be protected.

From conceptual process models to running systems: A holistic approach for the configuration of enterprise system processes

This paper proposes a method which aims at increasing the efficiency of enterprise system implementations. First, we argue that existing process modeling languages that feature different degrees of abstraction for different user groups exist and are used for different purposes which makes it necessary to integrate them. We describe how to do this using the meta models of the involved languages. Second, we argue that an integrated process model based on the integrated meta model needs to be configurable and elaborate on the enabling mechanisms. We introduce a business example using SAP modeling techniques to illustrate the proposed method.

Role of 3D visual conceptualisation of groundwater system models as a management support tool

After the recent prolonged drought conditions in many parts of Australia it is increasingly recognised that many groundwater systems are under stress. Although this is obvious for systems that are utilised for intensive irrigation many other groundwater systems are also impacted.Management strategies are highly variable to non-existent. Policy and regulation are also often inadequate, and are reactive or politically driven. In addition, there is a wide range of opinion by water users and other stakeholders as to what is “reasonable”management practice. These differences are often related to the “value”that is put on the groundwater resource. Opinions vary from “our right to free water”to an awareness that without effective management the resource will be degraded. There is also often misunderstanding of surface water-groundwater linkages, recharge processes, and baseflow to drainage systems.

Complex modelling of open system design for sustainable architecture

This paper argues a model of complex system design for sustainable architecture within a framework of entropy evolution. The spectrum of sustainable architecture consists of the efficient use of energy and material resource in life-cycle of buildings, the active involvement of the occupants in micro-climate control within buildings, and the natural environmental context. The interactions of the parameters compose a complex system of sustainable architectural design, of which the conventional linear and fragmented design technologies are insufficient to indicate holistic and ongoing environmental performance. The complexity theory of dissipative structure states a microscopic formulation of open system evolution, which provides a system design framework for the evolution of building environmental performance towards an optimization of sustainability in architecture.

In vitro cultivation of adult human chondrocytes : importance of culture system, oxygen and zonal differences

Articular cartilage exhibits limited intrinsic regenerative capacity and focal tissue defects can lead to the development of osteoarthritis (OA), a painful and debilitating loss of cartilage tissue. In Australia, 1.4 million people are affected by OA and its prevalence is increasing in line with current demographics. As treatment options are limited, new therapeutic approaches are being investigated including biological resurfacing of joints with tissue-engineered cartilage. Despite some progress in the field, major challenges remain to be addressed for large scale clinical success. For example, large numbers of chondrogenic cells are required for cartilage formation, but chondrocytes lose their chondrogenic phenotype (dedifferentiate) during in vitro propagation. Additionally, the zonal organization of articular cartilage is critical for normal cartilage function, but development of zonal structure has been largely neglected in cartilage repair strategies. Therefore, we hypothesised that culture conditions for freshly isolated human articular chondrocytes from non-OA and OA sources can be improved by employing microcarrier cultures and a reduced oxygen environment and that oxygen is a critical factor in the maintenance of the zonal chondrocyte phenotype. Microcarriers have successfully been used to cultivate bovine chondrocytes, and offer a potential alternative for clinical expansion of human chondrocytes. We hypothesised that improved yields can be achieved by propagating human chondrocytes on microcarriers. We found that cells on microcarriers acquired a flattened, polygonal morphology and initially proliferated faster than monolayercultivated cells. However, microcarrier cultivation over four weeks did not improve growth rates or the chondrogenic potential of non-OA and OA human articular chondrocytes over conventional monolayer cultivation. Based on these observations, we aimed to optimise culture conditions by modifying oxygen tension, to more closely reflect the in vivo environment. We found that propagation at 5% oxygen tension (moderate hypoxia) did not improve proliferation or redifferentiation capacity of human osteoarthritic chondrocytes. Moderate hypoxia increased the expression of chondrogenic markers during redifferentiation. However, osteoarthritic chondrocytes cultivated on microcarriers exhibited lower expression levels of chondrogenic surface marker proteins and had at best equivalent redifferentiation capacities compared to monolayer-cultured cells. This suggests that monolayer culture with multiple passaging potentially selects for a subpopulation of cells with higher differentiation capacity, which are otherwise rare in osteoarthritic, aged cartilage. However, fibroblastic proteins were found to be highly expressed in all cultures of human osteoarthritic chondrocytes indicating the presence of a high proportion of dedifferentiated, senescent cells with a chondrocytic phenotype that was not rescued by moderate hypoxia. The different zones of cartilage support chondrocyte subpopulations, which exhibit characteristic protein expression and experience varying oxygen tensions. We, therefore, hypothesised that oxygen tension affects the zonal marker expression of human articular chondrocytes isolated from the different cartilage layers. We found that zonal chondrocytes maintained these phenotypic differences during in vitro cultivation. Low oxygen environments favoured the expression of the zonal marker proteoglycan 4 in superficial cells, most likely through the promotion of chondrogenesis. The putative zonal markers clusterin and cartilage intermediate layer protein were found to be expressed by all subpopulations of human osteoarthritic chondrocytes ex vivo and, thus, may not be reliable predictors of in vitro stratification using these clinically relevant cells. The findings in this thesis underline the importance of considering low oxygen conditions and zonal stratification when creating native-like cartilaginous constructs. We have not yet found the right cues to successfully cultivate clinically-relevant human osteoarthritic chondrocytes in vitro. A more thorough understanding of chondrocyte biology and the processes of chondrogenesis are required to ensure the clinical success of cartilage tissue engineering.