Implementing Session Centered Calculi

Recently, specific attention has been devoted to the development of service oriented process calculi. Besides the foundational aspects, it is also interesting to have prototype implementations for them in order to assess usability and to minimize the gap between theory and practice. Typically, these implementations are done in Java taking advantage of its mechanisms supporting network applications. However, most of the recurrent features of service oriented applications are re-implemented from scratch. In this paper we show how to implement a service oriented calculus, CaSPiS (Calculus of Services with Pipelines and Sessions) using the Java framework IMC, where recurrent mechanisms for network applications are already provided. By using the session oriented and pattern matching communication mechanisms provided by IMC, it is relatively simple to implement in Java all CaSPiS abstractions and thus to easily write the implementation in Java of a CaSPiS process

Introducing New Methodologies for Identifying Design Patterns for Internationalization and Localization

This paper describes a new methodology for deriving interaction design patterns from an analysis of ethnographic data. It suggests using inductive and deductive analysis processes to identify and articulate patterns that address the needs of culturally diverse users of interactive, collaborative systems. This might inform the internationalization and localization process of computer supported collaboration systems

Dataplane Specialization for High-performance OpenFlow Software Switching

OpenFlow is an amazingly expressive dataplane program- ming language, but this expressiveness comes at a severe performance price as switches must do excessive packet clas- sification in the fast path. The prevalent OpenFlow software switch architecture is therefore built on flow caching, but this imposes intricate limitations on the workloads that can be supported efficiently and may even open the door to mali- cious cache overflow attacks. In this paper we argue that in- stead of enforcing the same universal flow cache semantics to all OpenFlow applications and optimize for the common case, a switch should rather automatically specialize its dat- aplane piecemeal with respect to the configured workload. We introduce ES WITCH , a novel switch architecture that uses on-the-fly template-based code generation to compile any OpenFlow pipeline into efficient machine code, which can then be readily used as fast path. We present a proof- of-concept prototype and we demonstrate on illustrative use cases that ES WITCH yields a simpler architecture, superior packet processing speed, improved latency and CPU scala- bility, and predictable performance. Our prototype can eas- ily scale beyond 100 Gbps on a single Intel blade even with complex OpenFlow pipelines

Evaluating the implications of attack and security patterns with premortems.

Security patterns are a useful way of describing, packaging and applying security knowledge which might otherwise be unavailable. However, because patterns represent partial knowledge of a problem and solution space, there is little certainty that addressing the consequences of one problem won't introduce or exacerbate another. Rather than using patterns exclusively to explore possible solutions to security problems, we can use them to better understand the security problem space. To this end, we present a framework for evaluating the implications of security and attack patterns using premortems: scenarios describing a failed system that invites reasons for its failure. We illustrate our approach using an example from the EU FP 7 webinos project

Pemanfaatan Citra Quickbird untuk Pemetaan Permukiman Kumuh dan Tingkat Prioritas Penanganan di Kecamatan Semarang Utara

Permukiman kumuh di Kecamatan Semarang Utara disebabkan oleh kualitas lingkungan yang menurun dan peningkatan kepadatan penduduk. Penelitian ini dilakukan untuk mengkaji manfaat citra Quickbird dalam menyadap parameter kekumuhan, memetakan persebaran permukiman kumuh, dan mengetahui prioritas penanganan permukiman kumuh. Metode yang digunakan adalah interpretasi visual parameter kekumuhan dari citra Quickbird tahun 2011. Penentuan sampel dilakukan dengan metode proportionate stratified random sampling, wawancara, dan uji ketelitian interpretasi. Penentuan tingkat prioritas penanganan kumuh disesuaikan dengan aspek non fisiknya. Tingkat ketelitian interpretasi citra Quickbird dalam menyadap informasi kekumuhan berkisar antara 90,46% sampai 94,47%.. Hasil akhir penelitian ini berupa peta persebaran permukiman kumuh yang terbagi menjadi 4 kelas, yaitu tidak kumuh (352 blok), kumuh ringan (32 blok), kumuh sedang (187 blok), dan kumuh berat (88 blok). Kondisi kumuh yang mendapatkan prioritas utama untuk ditangani cenderung berada di lahan milik pemerintah yang digunakan oleh masyarakat umum

The Interpreter In An Undergraduate Compilers Course

An undergraduate compilers course poses significant challenges to students, in both the conceptual richness of the major components and in the programming effort necessary to implement them. In this paper, I argue that a related architecture, the interpreter, serves as an effective conceptual framework in which to teach some of the later stages of the compiler pipeline. This framework can serve both to unify some of the major concepts that are taught in a typical undergraduate course and to structure the implementation of a semester-long compiler project.Comment: Final version to appear in SIGCSE '1