Using Java for distributed computing in the Gaia satellite data processing

In recent years Java has matured to a stable easy-to-use language with the flexibility of an interpreter (for reflection etc.) but the performance and type checking of a compiled language. When we started using Java for astronomical applications around 1999 they were the first of their kind in astronomy. Now a great deal of astronomy software is written in Java as are many business applications. We discuss the current environment and trends concerning the language and present an actual example of scientific use of Java for high-performance distributed computing: ESA's mission Gaia. The Gaia scanning satellite will perform a galactic census of about 1000 million objects in our galaxy. The Gaia community has chosen to write its processing software in Java. We explore the manifold reasons for choosing Java for this large science collaboration. Gaia processing is numerically complex but highly distributable, some parts being embarrassingly parallel. We describe the Gaia processing architecture and its realisation in Java. We delve into the astrometric solution which is the most advanced and most complex part of the processing. The Gaia simulator is also written in Java and is the most mature code in the system. This has been successfully running since about 2005 on the supercomputer "Marenostrum" in Barcelona. We relate experiences of using Java on a large shared machine. Finally we discuss Java, including some of its problems, for scientific computing.Comment: Experimental Astronomy, August 201

Introducing Java : the case for fundamentals-first

Java has increasingly become the language of choice for teaching introductory programming. In this paper, we examine the different approaches to teaching Java (Objects-first, Fundamentals-first and GUI-first) to ascertain whether there exists an agreed ordering of topics and difficulty levels between nine relatively basic Java topics. The results of our literature survey and student questionnaire suggests that the Fundamentals-first approach may have benefits from the student's point of view and an agreed ordering of the Java topics accompanying this approach has been established

A Java Reference Model of Transacted Memory for Smart Cards

Transacted Memory offers persistence, undoability and auditing. We present a Java/JML Reference Model of the Transacted Memory system on the basis of our earlier separate Z model and C implementation. We conclude that Java/JML combines the advantages of a high level specification in the JML part (based on our Z model), with a detailed implementation in the Java part (based on our C implementation)

Provably correct Java implementations of Spi Calculus security protocols specifications

Spi Calculus is an untyped high level modeling language for security protocols, used for formal protocols specification and verification. In this paper, a type system for the Spi Calculus and a translation function are formally defined, in order to formalize the refinement of a Spi Calculus specification into a Java implementation. The Java implementation generated by the translation function uses a custom Java library. Formal conditions on such library are stated, so that, if the library implementation code satisfies such conditions, then the generated Java implementation correctly simulates the Spi Calculus specification. A verified implementation of part of the custom library is further presente

ANALISIS PENGARUH PRODUK DOMESTIK REGIONAL BRUTO, TINGKAT PENGANGGURAN TERBUKA DAN TINGKAT PENDIDIKAN TERHADAP KEMISKINAN DI PROVINSI JAWA TIMUR TAHUN 2017-2021

The purpose of this study is to explain GRDP, Unemployment Rate and Education Level jointly affect the Poverty Rate in East Java Province in 2017-2021 in East Java and explain the more dominant independent variables between GDP, unemployment rate, level of education on level poverty in East Java Province. The method used in this study is multiple linear regression analysis on panel data. The analysis tool used is e-views 9. This study uses a quantitative approach with 38 observation objects in the 2017-2021 time frame. The results of this study are based on the F test of economic growth variables, unemployment rates and education levels have an effect on poverty levels. then the results of the t-test show that the unemployment rate and education level variables significantly influence the poverty rate in East Java Province in 2017-2021. However, the education level variable is not significant for the poverty rate in East Java Province in 2017-2021