14636461
Introducing object-oriented programming into the computer science curriculum
In recent years, object-oriented programming languages and object-oriented program design have become increasingly popular. Dialects of many popular programming languages are now available which support the major concepts of object-oriented programming; namely message-passing, classes, generic operations and inheritance. Experience in the paradigm is increasingly supporting the view that object-oriented programming may be to the 80's what structured programming was to the 70's in terms of its influence on software development.
After reviewing the notions of object-oriented programming, we describe our experiences in introducing the object-oriented paradigm into the Computer Science curriculum. The impact was felt in four courses dealing with data types and data structures, programming languages, software engineering, and compiler construction. In addition, we describe the use of the Smalltalk environment in advanced course and project work. We chronicle our experiences in the expectation that they will be of benefit to other educators considering adopting the object-oriented paradigm. Finally, we review the potential benefits of introducing object-oriented programming into the computer science curriculum.
41645329
The (Re) Emergence of Agile Languages and Domain-Oriented Programming
The JAOO conference in Aarhus, Denmark has become one of the most enjoyable and informative developer conferences in the land of OO. Originally a Java conference, it has expanded to cover a wide variety of topics from MS.NET and Java technology to best practices in software engineering. This year's conference followed on the heels of the Microsoft PDC earlier in the month. Both conferences featured tracks and sessions on scripting, dynamic languages and domain specific languages. There was also a Dynamic Languages Symposium Would any OO professional really consider using Basic when she has access to the full power of C#? Can MS really make it possible for disenfranchised Basic developers to have first class language access to XML, Databases and Objects with ease? Many at the PDC and JAOO were in shock as Erik Meijer (http://research.microsoft.com/~emeijer/) and the VB team showed off VB 9 features that combine clever type inference and structural sub-typing to simply and elegantly manipulate squares (relational tuples), circles (objects) and triangles (XML info sets) as simple polymorphic collections. Erik has also abandoned his solemn monadic oath of Haskell and quietly snuck some really interesting functional machinery under the hood of C#3.0 and VB 9 Erik is of course one of the key contributors to MS Zen and COmega (http://research.microsoft.com/COmega/) research efforts which are now bearing fruit in MS next language products under the name Language Integrated Query (LINQ – The LINQ team has really been thinking out of the box on this project and has made brave new efforts with very popular and widely used languages, which is always a great language design and implementation challenge.
9882210
MDA: revenge of the modelers or UML utopia?
Modeling is at the core of many disciplines, but it is especially important in engineering because it facilitates communication and constructs complex things from smaller parts. Model engineering or model-driven development, treats software development as a set of transformations between successive models from requirements to analysis, to design, to implementation, to deployment. We discuss UML and MDA tools for developing software models. We also discuss domain specific languages, domain-oriented programming, platform-specific models and model engineering.
11005034
Fostering software robustness in an increasingly hostile world
Software can kill. What are you doing to stay alive? Our world faces an increasingly hostile environment with challenges in complexity, technology, social engineering and clashing cultures. Failure to achieve sufficient software robustness can lead to customer dissatisfaction, financial loss, or in extreme cases -- loss of life. This panel brings together differing contexts and solution approaches.
2028674
An Exemplar Based Smalltalk
Two varieties of object-oriented systems exist: one based on classes as in Smalltalk and another based on exemplars (or prototypical objects) as in Act/1. By converting Smalltalk from a class based orientation to an exemplar base, independent instance hierarchies and class hierarchies can be provided. Decoupling the two hierarchies in this way enables the user's (logical) view of a data type to be separated from the implementer's (physical) view. It permits the instances of a class to have a representation totally different from the instances of a superclass. Additionally, it permits the notion of multiple representations to be provided without the need to introduce specialized classes for each representation. In the context of multiple inheritance, it leads to a novel view of inheritance (or-inheritance) that differentiates it from the more traditional multiple inheritance notions (and-inheritance). In general, we show that exemplar based systems are more powerful than class based systems. We also describe how an existing class based Smalltalk can be transformed into an exemplar-based Smalltalk and discuss possible approaches for the implementation of both and-inheritance and or-inheritance.
25083231
Meeting the challenge of software engineering education for working professionals in the 21st century
Software engineering education for working professionals remains a challenge from the perspective of determining relevant content; identifying effective methods for delivery; and maintaining the focus and motivation of students. This panel brings together academic and industry professionals to share their perspectives and experiences. Anticipated points for discussion include: education/training delivery strategies, curriculum definition, certification challenges, marketing issues, collaboration strategies to engage industry sponsorship, value assessments for students and sponsoring organizations, and program success stories. This will be a highly interactive panel and the audience should come prepared to both ask and answer questions.
41519577
Anonymizing Tables
We consider the problem of releasing tables from a relational database containing personal records, while ensuring individual privacy and maintaining data integrity to the extent possible. One of the techniques proposed in the literature is k-anonymization. A release is considered k-anonymous if the information for each person contained in the release cannot be distinguished from at least k–1 other persons whose information also appears in the release. In the k-Anonymityproblem the objective is to minimally suppress cells in the table so as to ensure that the released version is k-anonymous. We show that the k-Anonymity problem is NP-hard even when the attribute values are ternary. On the positive side, we provide an O(k)-approximation algorithm for the problem. This improves upon the previous best-known O(klog k)-approximation. We also give improved positive results for the interesting cases with specific values of k — in particular, we give a 1.5-approximation algorithm for the special case of 2-Anonymity, and a 2-approximation algorithm for 3-Anonymity.
45579896
Full Minimal Steiner Trees on Lattice Sets
Given a finite set of points P in the Euclidean plane, the Steiner problem asks us to constuct a shortest possible network interconnecting P. Such a network is known as a minimal Steiner tree. The Steiner problem is an intrinsically difficult one, having been shown to be NP-hard [7]; however, it often proves far more tractable if we restrict our attention to points in special geometric configurations. One such restriction which has generated considerable interest is that of finding minimal Steiner trees for nice sets of integer lattice points. The first significant result in this direction was that of Chung and Graham [4], which, in effect, precisely characterized the minimal Steiner trees for any horizontal 2_n array of integer lattice points. In 1989, Chung et al. [3] examined a related problem, which they described as the Checkerboard Problem. They asked how to find a minimal Steiner tree for an n_n square lattice, that is, a collection of n_n points arranged in a regular lattice of unit squares like the corners of the cells of article no. TA962752
5754219
Privacy preserving OLAP
We present techniques for privacy-preserving computation of multidimensional aggregates on data partitioned across multiple clients. Data from different clients is perturbed (randomized) in order to preserve privacy before it is integrated at the server. We develop formal notions of privacy obtained from data perturbation and show that our perturbation provides guarantees against privacy breaches. We develop and analyze algorithms for reconstructing counts of subcubes over perturbed data. We also evaluate the tradeoff between privacy guarantees and reconstruction accuracy and show the practicality of our approach.
2682242
Two Can Keep A Secret: A Distributed Architecture for Secure Database Services
Recent trends towards database outsourcing, as well as concerns and laws governing data privacy, have led to great interest in enabling secure database services. Previous approaches to enabling such a service have been based on data encryption, causing a large overhead in query processing. We propose a new, distributed architecture that allows an organization to outsource its data management to {\em two} untrusted servers while preserving data privacy. We show how the presence of two servers enables efficient partitioning of data so that the contents at any one server are guaranteed not to breach data privacy. We show how to optimize and execute queries in this architecture, and discuss new challenges that emerge in designing the database schema.
15059814
Caching queues in memory buffers
Motivated by the need for maintaining multiple, large queues of data in modern high-performance systems, we study the problem of caching queues in memory under the following simple, but widely applicable, model. At each clock-tick, any number of data items may enter the various queues, while data-items are consumed from the heads of the queues. Since the number of unconsumed items may exceed memory buffer size, some items in the queues need to be spilled to secondary storage and later moved back into memory for consumption. We provide online queue-caching algorithms under a number of interesting cost models.