Formal Modeling and Analysis of Mobile Ad hoc Networks

Fokkink, W.J. [Promotor]Luttik, S.P. [Copromotor

Komentar Semi Otomatis Untuk Memudahkan Pemahaman Pada Bahasa Pemrograman Java

Studi memperkirakan bahwa biaya perawatan perangkat lunak meningkat dengan sangat cepat hingga mencapai 90% dari biaya keseluruhan dalam daur hidup pengembangan perangkat lunak. Perawatan perangkat lunak menjadi sangat sulit dikarenakan tidak adanya dokumentasi pada program yang ada. Salah satu bentuk dokumentasi program adalah pemberian komentar program. Komentar sangat berguna dalam pemahaman program dan pemeliharaan program. Komentar memungkinkan pengembang dalam memahami kode lebih cepat dalam pembacaan kode program. Pemberian komentar program biasanya dilakukan manual oleh programmer. Pada tesis ini, dilakukan dua kegiatan pemberian komentar pada bahasa pemrograman java, yaitu pemberian komentar secara otomatis dan pemberian komentar secara semi otomatis. Komentar semi otomatis yang diberikan pada program secara langsung dapat mempermudah proses pemahaman pada program khususnya bahasa pemrograman java. Penggunaan ekspresi regular sangat membantu dalam mempolakan baris kode sumber. Aplikasi yang dibangun oleh peneliti telah mampu memberikan kontribusi pemahaman terhadap program sebesar 14.29% sampai dengan 42.86% ==================================================================================================================The study estimates that the cost of software maintenance is increasing very rapidly until it reaches 90% of the overall cost of the software development life cycle. Software maintenance becomes very difficult due to the lack of documentation on the existing program. One form of program documentation was commenting program. Comments are very useful in understanding the program and maintenance program. The comment allows developers to understand the code faster in reading the program code. Commenting program is usually done manually by the programmer. In this thesis, carried out two activities commenting on the Java programming language, the automatic comment and semi-automatic comment. Semi-automatic comments given on direct program is expected to simplify the process of understanding the particular program java programming language. The use of regular expressions is helpful in patterns of lines of source code. Applications built by the researchers have been able to contribute to the understanding of the program at 14.29% to 42.86%

Mara Salvatrucha (MS-13): The Imminent Threat Inside Our Borders and Throughout the Continent

For the past decade, citizens, governments, and scholars alike have expressed ongoing concerns about the increasing rates of violent crimes committed by drug traffickers, organized criminal groups, and gangs within the United States and Central America. The gang Mara Salvatrucha, familiarly known as MS-13, arguably presents the largest threat to national and regional security. The gang’s relatively recent emergence, growth, and expansion has raised serious concern. The criminal group is responsible for a multitude of crimes that directly threaten the welfare of citizens and state security from the suburbs of Washington D.C. to slums in Central American. This gang’s coast-to-coast presence plagues cities and communities across the United States, claiming territory in at least 42 states. MS-13 now claims 10,000 members in the U.S. and 70,000 Latin American members across the entire American continent (FBI 2008). The U.S. government’s concerns about gangs have heightened with the increasing growth of MS-13, both in membership and sophistication. Congress maintains an interest in crime and gang violence in Central America, as well as the related activities of the U.S. branches of MS-13 within our borders. Central American governments, the media, and some scholars have attributed a significant proportion of violent crime plaguing the region to the recent globalization of U.S. gang culture. This thesis provides a current overview of the threat posed by MS-13, as well its historical origins and evolution as a criminal organization. The first half analyzes the birth of the gang in Los Angeles in the 1980s and the political factors contributing to MS-13’s continental migration south over the past two decades. American criminal deportations play an important role in the transnational nature of MS-13 and will be analyzed. Many blame U.S. deportation policies for the globalization of the gang and fueling the current gang epidemic in Central America. Subsequently, the context in which the gang operates within Central America, specifically in El Salvador is examined. Many scholars and government officials agree that the suppressive policies enacted by Central American states, specifically the Mano Dura (“hard hand”) laws have failed at countering both MS-13 membership and its associated crime and violence. The latter half of this thesis focuses on the evolution of U.S. policy responses, at the international level, enacted to address the security implications posed by MS-13. The concern of this thesis is not whether the U.S. government is responding but rather if its responses are designed and implemented thoughtfully so that the limited funding is allocated effectively. Policy-makers in the U.S. and Central American are struggling to find the right combination of suppressive and preventive policies to combat MS-13. Most analysts agree that a more comprehensive, regional approach to the sophisticated gang is necessary to prevent further escalation of the problems created by the gang’s illicit activity

Midterm evaluation Research 2016-2018:

The research of TU Delft’s Faculty of Architecture and the Built Environment (Faculteit Bouwkunde) covers the full spectrum of design, engineering, planning, and management of the built environment. Its research portfolio comprises the research that is conducted by four departments: Architecture Architectural Engineering + Technology (AE+T) Management in the Built Environment (MBE) Urbanism The faculty’s research focusses specifically at improving the design and performance of buildings, districts, cities and regions in order to better meet the requirements and expectations of their users and communities. From that perspective, much of the research that is conducted can be understood as applied science, appealing to the curiosity and the needs of other researchers, practitioners and the broader public alike. The research is a blend of humanities, social and engineering sciences. The humanities are strongest represented in the Architecture department, social sciences in the MBE and Urbanism departments, while the engineering sciences find their strongest representation in AE+T

Improving interoperability in distributed multi-tier software stacks

Distributed multi-tier software stacks organise and deploy software components as a hierarchy of interacting tiers. The components are typically heterogeneous, i.e. each component may be written in a different language and may interoperate using a variety of protocols. Tiered software is modular but leads to a range of interoperability challenges including the following. (1) Interoperating components in multiple languages and paradigms increases developer cognitive load since they must simultaneously reason in multiple languages and paradigms. (2) There must be correct interoperation of components, e.g. adherence to the API or communication protocols between components. (3) Interoperation between different components can lead to diverse modes of failure as each component can fail in unique ways. Many of these challenges are the result of contributing factors like tight coupling or polyglot programmming. This thesis investigates techniques to improve heterogeneous interoperability in distributed multi-tier software stacks. Some common approaches include microservices and tierless languages. Microservices are perceived to offer better reliability than components in multi-tier software stacks through the loose coupling of services. The reliability of microservices is investigated by combining the established properties of dependence and state with reliability. This defines a new three-dimensional space: the Microservices Dependency State Reliability (MDSR) classification with six classes. The feasibility of statically identifying MDSR classes is demonstrated with a prototype analyser that identifies all six classes in Flask microservices web applications. The reliability implications of the different MDSR classes are evaluated by running three case study applications (Hipster-Shop, JPyL & WordPress) against a fault injector. Key results are as follows. (1) All applications fail catastrophically if a critical microservice fails. (2) Applications survive the failure of individual minor microservice(s). (3) The failure of any chain of microservices in JPyL & Hipster is catastrophic. (4) Individual microservices do not necessarily have minor reliability implications. In a tierless language, the compiler generates the code for each component and ensures their correct interoperation. They are mainly used to implement web stacks. However, their use in implementing IoT stacks is less common. This investigation compares interoperation in tiered and tierless IoT stacks through the systematic evaluation of four implementations of the prototype UoG smart campus IoT system: two tierless and two Python-based tiered. Key results of the study are as follows. (1) Tierless languages have the potential to significantly reduce the development effort for IoT systems, requiring 70% less code than the tiered implementations. (2) Tierless languages have the potential to significantly improve the reliability of IoT systems. (3) The first comparison of a tierless codebase for resource-rich sensor nodes and one for resourceconstrained sensor nodes shows that they have very similar functional structure and code sizes - within 7%. Tier elimination is a technique that removes a tier/component by integrating two tiers. Specifically, this thesis investigates the implications of eliminating the Apache web server in a 4-tier web stack: Jupyter Notebook, Apache, Python, Linux (JAPyL) and replacing it with PHP libraries in the frontend webpage to get the 3-tier (JPL). The study reveals the following. (1) The JPL 3-tier web stack requires that the developer uses fewer programming languages and paradigms than JAPyL, i.e two compared with four languages and two compared with three paradigms. (2) JPL requires 42% less code than JAPyL. (3) In JPL, some of the functionalities can be automated due to the decreased abstraction levels at the upper layers of the stack. (4) However, the latency in JPL is two to three times greater than that of JAPyL. So while tier elimination reduces developer effort and semantic friction the tradeoffs are high performance overhead & resource consumption and increasing code complexity