bluuebunny/crossref_metadata_2025 huggingface dataset:
A flash photolytic investigation of the photosolvolysis of α-(2,6-dimethoxyphenyl)vinyl chloride. Characterization of the 2,6-dimethoxyacetophenone keto–enol system
Authors: Chiang Yvonne , Eliason Robert , Jones Joel , Kresge A. Jerry , Evans Kevin L. , Gandour Richard D.
Published: May 2006

Photosolvolysis of α-(2,6-dimethoxyphenyl)vinyl chloride in trifluoroethanol solution at 25 °C was found to produce the α-(2,6-dimethoxyphenyl)vinyl cation as a transient species with the lifetime τ = 1 μs. Addition of water reduced this lifetime markedly, until, at compositions greater than 80% water, it was too short to measure (τ < 20 ns); extrapolation of the data suggests τ = 9 ns in pure water. Hydration of this cation gave the much longer lived enol of 2,6-dimethoxyacetophenone, whose rates of ketonization were measured in dilute perchloric acid and sodium hydroxide solutions. These data, when combined with rates of enolization of the ketone determined by iodine scavenging, give pKE = 6.98 for the keto–enol equilibrium constant in the 2,6-dimethoxyacetophenone system, [Formula: see text] for the acidity constant of the enol ionizing as an oxygen acid, and [Formula: see text] for the acidity constant of the ketone ionizing as a carbon acid; these constants refer to wholly aqueous solution at 25 °C and ionic strength = 0.10 M.
In situ Fourier transform infrared spectroelectrochemical studies of the oxidation of some octaethylporphyrin complexes
Authors: Hinman A. Scott , Olorunyolemi Temitayo
Published: May 2006

The oxidations of OEPNi(II), OEPCu(II), OEPFe(III)Cl, OEPMn(III)ClO4, OEPAg(II), OEPCo(II), and OEPZn(II) (OEP = 2,3,7,8,12,13,17,18-octaethylporphyrin dianion) have been studied by in situ FTIR reflectance spectroelectrochemistry in dibromomethane. One-electron oxidation of the porphyrin ring to produce a π-cation radical results in the appearance of a strong new absorbance band near 1550 cm−1. Other features typical of π-cation radical formation are a strong absorbance increase near 1470 cm−1, and absorbance decreases near 1270 and 1018 cm−1. Oxidation of the metal centre, as observed for OEPCo(II) in the presence of CH3CN, and for OEPAg(II), results in considerably less perturbation of the vibrational spectra of the complexes. For OEPCo(II) in dry dibromomethane, initial oxidation at the porphyrin ligand is followed by a second oxidation at the metal centre. This order is reversed when acetonitrile is added to solution. Production of porphyrin π-dications was observed for OEPCu(II) and OEPNi(II). This results in a shift of the 1550 cm−1 π-cation radical marker band to higher energy, and a strong absorbance increase near 1380 cm−1. Unusual spectral changes observed on one-electron oxidation of OEPZn(II) are suggested to result from the formation of a dimer.
Catalysis of the deprotonation of β-keto esters by cyclodextrins
Authors: Tee Oswald S. , Iyengar N. Rani , Takasaki Bryan K.
Published: May 2006

The rates of deprotonation of several β-keto esters in basic aqueous solution are elevated by α- and β-cyclodextrin (α- and β-CD). In most cases saturation kinetics are observed that indicate fairly strong binding of the esters to the CDs (Kd = 0.22–11 mM); catalytic ratios (kc/ku) are in the range 1.9–17. For esters of the form RCO-CH2COOEt with both α- and β-CD the values of Kd and kc/ku show little sensitivity to the acyl group, RCO (R = Me, Et, Pr, i-Pr), and for 2-carboethoxycyclopentanone, a cyclic analogue, these parameters are similar. In contrast, for R-COCH2CO-OR′ (R = Me or Et; R′ = Me, Et, allyl) there is a marked dependence of the parameters on the alkoxyl group, OR′. These results suggest that the β-keto esters studied bind to the CDs with their alkoxyl groups in the CD cavity and that the catalysis ensues from the complexes thus formed. Variations in two other kinetic parameters, k2 = kc/Kd (substrate selectivity) and KTS = ku/k2 (apparent constant for dissociation of CD from the transition state) support this interpretation. Apparent second-order rate constants for the reaction of the esters with neutral CD (k2 = kc/Kd) are 1900–360 000 M−1 s−1 (at pH ≈ 10), whereas for hydroxide ion attack on ethyl acetoacetate kOH = 5500 M−1 s−1. Assuming the pKas of the CDs are 12.2 and 12.3, deprotonation of the esters by the CD anions has rate constants of 105 to 5 × 107 M−1 s−1. Thus, binding of the β-keto esters in the CD cavities, adjacent to a basic oxyanion site, enhances the reactivity of the CD anions towards these weak carbon acids by at least 2–4 orders of magnitude.
Properties of some alkali fluoride–chloride salt mixtures I. Primary crystallization and density measurements
Authors: Rajagopalan N. , Belawadi J.B. , Sen Utpal
Published: May 2006

The primary crystallization and density of the fluoride–chloride salt systems (i) NaF–LiCl and (ii) NaF–(LiCl + KCl) eutectic were determined experimentally using thermal analysis and the Archimedean technique, respectively. The corresponding liquidus curves for the two systems were constructed and compared. Molar volume and excess volume functions were computed from density data at different compositions and temperatures. The positive values of the excess volumes correspond to volume expansion that increases with temperature for both systems. The results suggest that as far as the primary crystallization and density behaviours are concerned, it is possible to replace the component, pure LiCl, in the fluoride–chloride salt system by the eutectic mixture of (LiCl + KCl) for the system's use as a potential electrolyte for aluminium electrolysis.
Molecular dynamics simulation of interhalogen compounds using two potential models 2. Liquid bromine trifluoride (BrF3) — structure and thermodynamics
Authors: Saxena Vivek
Published: May 2006

This paper reports on the molecular dynamics simulation results of liquid bromine trifluoride (BrF3) at 299, 315, and 363 K. We have assumed that the molecules interact via Lennard–Jones 12–6 site–site pair potential and Lennard–Jones site–site + fractional charges over atomic sites. Lennard–Jones potential parameters of Singer et al. (Mol. Phys. 33, 1757 (1977)) have been used for Br–Br, and F–F interactions and cross interaction terms are calculated using Lorentz–Berthelot mixing rules. Fractional charges are assigned to reproduce the experimentally determined gaseous-state molecular dipole moment. Various structural and thermodynamic properties for liquid state are reported and compared in detail with results from diffraction studies (Mittkin et al. J. Struct. Chem. 28, 60 (1987)). Some mechanical properties such as mean-square force and torque, self-diffusion coefficient have also been calculated. The repulsive part of the proposed atom–atom pair potential is a good approximation since both molecular configurations are in good agreement with experimental results.
The role of catalyst activation in the enantioselective hydrogenation of methyl acetoacetate over silica-supported nickel catalysts
Authors: Keane Mark A.
Published: May 2006

A range of Ni–SiO2 catalysts have been prepared by homogeneous precipitation–deposition and impregnation techniques and modified with aqueous solutions of R-(+)-tartaric acid (TA) to induce enantioselectivity in the asymmetric hydrogenation of a prochiral β-ketoester (methyl acetoacetate) to a β-hydroxyester ((R)-(−)-methyl 3-hydroxybutyrate). The effects of catalyst precursor preparation, nickel loading, and precalcination on the reduction of the precursor were examined and the nature of the resultant nickel particle size distribution is described. The influence of metal–support interactions on the uptake of TA was investigated and data on the corrosive metal leaching and the consequent changes in metal dispersion are presented. Modification of the catalysts with TA not only induced enantioselectivity, but also increased the turnover frequency by up to 15 times that observed for the unmodified surface. The amount of TA adsorbed and the fractional surface coverage by TA is related to the degree of enantiodifferentiation. The effects of variations in supported nickel metal particle sizes (in the overall range of 1.4–13.6 nm) on the reaction rate and enantioselectivity were examined; while the selectivity was independent of metal particle size, the rate of hydrogenation was found to be structure sensitive and a correlation between reaction rate sensitivity and particle size is presented.
Ab initio study of C—H bond breaking in olefins. II. GVB computations on propene ↔ H + cis- or trans-propen-1-yl
Authors: De Maré George R. , Evleth Earl M. , Poirier Raymond A. , Collin Guy J.
Published: May 2006

The Generalized-Valence-Bond-Perfect-Pairing (GVB-PP) method has been used to investigate the structural behaviour, energy, and dipole moment along the reaction coordinates for propene ↔ H + cis- or trans-propen-1-yl. Geometry optimizations were carried out at the GVB(9)/STO-3G level (complete valence shell) for the minimum energy propene structure (complete optimization) and for numerous structures up to r(C—H) = 10 Å (only the elongated C—H distance kept fixed). The dissociation curves are smooth, without a maximum, and yield predicted dissociation energies of propene to H + cis-propen-1-yl and H + trans-propen-1-yl of 555.8 and 554.8 kJ mol−1, respectively. These values are within several percent of those obtained for C—H bond rupture in ethylene using GVB and MCSCF methods with the same basis set. They are obviously too high but they confirm that removal of a hydrogen atom from the CH2 moiety in propene requires about the same energy as removal of a hydrogen atom from ethylene. GVB(7)/6-31G//GVB(9)/STO-3G computations lower the predicted dissociation energies of propene ↔ H + cis-propen-1-yl and H + trans-propen-1-yl to 448.2 and 448.6 kJ mol−1, respectively.The reduced energy concept (ER = (E∞ − Er)/De) is applied to the reaction coordinates. Linear behaviour for In ER versus bond length is observed at long bond distances. At r(C—H) = 3 Å, the values of the slopes, d(ln ER)/dr(C—H), which are related to the effective Morse constant B are −3.73 and −3.74 (GVB(9)/STO-3G) and −2.75 and −2.81 (GVB(7)/6-31 G//GVB(9)/STO-3G) for the H + cis- and H + tras-propen-1-yl reaction coordinates, respectively.
Design and synthesis of analogues of ionomycin
Authors: Hu Thomas Q. , Weller Larry
Published: May 2006

Based on the analysis of the crystal structure of the Ca2+ salt of ionomycin and the chemical and physical data on ionomycin, a number of ionomycin analogues have been synthesized to study the structural features affecting the Ca2+ binding and transport. Compounds 2, 3, and 4 were synthesized to study the effect of additional intramolecular oxygen coordination sites on Ca2+ transport. Compounds 5a–5d were prepared to study the effect of lipid solubility on Ca2+ binding and transport. Compounds 6a–6c were prepared to study the effect of the distance between the β-diketone and the carboxyl group on Ca2+ transport. A general synthetic route to these compounds has been developed. The key reactions in this route are the consecutive regioselective alkylations of the dianion of 2,4-pentanedione with the appropriate bromides.[Formula: see text]
Synthesis and separation of diastereomers of O-(2,2,2-trifluoroethyl)-3′,5′-dinucleoside phosphates
Authors: Luo Weide , Atrazheva Elena , Fregeau Nancy , Gmeiner William H. , Lown J. William
Published: May 2006

The synthesis, diastereomeric separation, and characterization are described for a series of novel O-(2,2,2-trifluoroethyl)-3′,5′-dinucleoside phosphates, required for incorporation into antisense probes in the magnetic resonance imaging investigation of biodistribution. Preliminary assignment of the absolute configuration of the Rp and Sp diastereomers is made on the basis of 31 P NMR spectra.
Incorporating realistic constraints into a student team software project
Authors: Goulding Tom , DiTrolio Rita
Published: May 2006

Instruction in the theory and practice of the System Design Life Cycle is a significant component of introductory software engineering courses. In this study, project development pressures and management realities, which imitate those found in an industrial setting, were used to enhance student team projects. This paper examines the results of those constraints and presents an assessment of student experiences.
Algorithm 847
Authors: Klimke Andreas , Wohlmuth Barbara
Published: May 2006

To recover or approximate smooth multivariate functions, sparse grids are superior to full grids due to a significant reduction of the required support nodes. The order of the convergence rate in the maximum norm is preserved up to a logarithmic factor. We describe three possible piecewise multilinear hierarchical interpolation schemes in detail and conduct a numerical comparison. Furthermore, we document the features of our sparse grid interpolation software package spinterp for MATLAB.
Tile-based QCA design using majority-like logic primitives
Authors: Huang J. , Momenzadeh M. , Schiano L. , Ottavi M. , Lombardi F.
Published: May 2006

The design of circuits and systems in Quantum-dot Cellular Automata (QCA) is still in infancy. The basic logic primitive in QCA is the majority voter (MV), that is not a universal function; so, inverters (INV) are also required. Blocks (referred to as tiles) are utilized in this article. A tile with a combined logic function of MV and INV (MV-like function) is proposed. It is shown that the MV-like tile can be effectively used in logic design as basic primitive. Tiles based on both the fully populated (FP) and non-fully populated (NFP) grids are investigated in detail. Various arrangements in inputs and outputs are also possible among the 4 sides of a grid, thus defining different tiles. Using a coherence vector simulation engine, it is shown that the 3 × 3 grid offers versatile logic operation. Different combinational functions such as majority-like and wire crossing are obtained using these tiles. Tile-based design of different circuits is compared to gate-based and SQUARES designs.
Incremental definition and operationalization of domain-specific markup languages in ADDS
Authors: Sierra José L. , Navarro Antonio , Fernández-Manjón Baltasar , Fernández-Valmayor Alfredo
Published: May 2006

ADDS is our proposal for the development of content-intensive applications. Applications in ADDS are produced by processing documents that describe their main aspects and that have been marked up using application-dependent, Domain-Specific Markup Languages (DSMLs). To make ADDS of practical value, we promote the incremental definition of DSMLs, as well as their incremental operationalization (i.e. the incremental construction of their processors). In this paper we describe how this incremental definition is carried out by using a technique called PADDS (DSML Provision in ADDS), and how incremental operationalization is accomplished using a model called OADDS (Operationalization in ADDS).
Automatic recovery from software failure
Authors: Robertson Paul , Williams Brian
Published: May 2006

A model-based approach to self-adaptive software.
Computer science education in the 21
st
century
Authors: Patterson David A.
Published: May 2006

To draw students to CS, we must first look to create a curriculum that reflects the exciting opportunities and challenges of IT today versus the 1970s. Future students and faculty would greatly benefit from a reinvigorated CS curriculum.
A specification language for coordinated objects
Authors: Ciobanu Gabriel , Lucanu Dorel
Published: May 2006

The paper presents a specification language of autonomous objects supervised by a coordinating process. The coordination is defined by means of an interaction wrapper. The coordination semantics is described in the terms of bisimulation relations. The properties of the coordinated objects are expressed as temporal formulas, and verified by specific model-checking algorithms. We use the alternating bit protocol to exemplify our specification language and its semantics.This approach allows a clear separation of concerns: the same coordinating process can be used with different concurrent objects, and the same objects can be used with a different coordinator. Thus our specification language allows easy modifications and customization. The method is effective in assembling increasingly complex systems from components. Moreover, composing different coordinating processes can be done without changing the code of the coordinated objects. In this way, the difficult task of implementing the mechanism of coordination becomes substantially easier.
Specification and verification of inter-component constraints in CTL
Authors: Thang Nguyen Truong , Katayama Takuya
Published: May 2006

The most challenging issue of component-based software is about component composition. Current component specification, in addition to the syntactic level, is very limited in dealing with semantic constraints. Even so, only static aspects of components are specified. This paper gives a formal approach to make component specification more comprehensive by including component semantic. Fundamentally, the component semantic is expressed via the powerful temporal logic CTL. There are two semantic aspects in the paper, component
dynamic behavior
and
consistency
- namely a component does not violate some property in another when composed. Based on the proposed semantic, components can be efficiently cross-checked for their consistency by an incremental verification method - OIMC, even for many future component extensions.
Theory of infinite streams and objects
Authors: Chekin Konstantin
Published: May 2006

This paper provides a theory of infinite streams and objects, which contains our point of view on the problem of formal modelling of behaviors of objects and their systems with big or infinite number of internal states.
Monodic temporal resolution
Authors: Degtyarev Anatoli , Fisher Michael , Konev Boris
Published: May 2006

Until recently, First-Order Temporal Logic (FOTL) has been only partially understood. While it is well known that the full logic has no finite axiomatisation, a more detailed analysis of fragments of the logic was not previously available. However, a breakthrough by Hodkinson et al., identifying a finitely axiomatisable fragment, termed the
monodic
fragment, has led to improved understanding of FOTL. Yet, in order to utilise these theoretical advances, it is important to have appropriate proof techniques for this monodic fragment.In this paper, we modify and extend the clausal temporal resolution technique, originally developed for propositional temporal logics, to enable its use in such monodic fragments. We develop a specific normal form for monodic formulae in FOTL, and provide a complete resolution calculus for formulae in this form. Not only is this clausal resolution technique useful as a practical proof technique for certain monodic classes, but the use of this approach provides us with increased understanding of the monodic fragment. In particular, we here show how several features of monodic FOTL can be established as corollaries of the completeness result for the clausal temporal resolution method. These include definitions of new decidable monodic classes, simplification of existing monodic classes by reductions, and completeness of clausal temporal resolution in the case of monodic logics with expanding domains, a case with much significance in both theory and practice.
An investigation into the effects of Text-To-Speech voice and 3D avatars on the perception of presence and flow of live help in electronic commerce
Authors: Qiu Lingyun , Benbasat Izak
Published: May 2006

Expansion and growth of online shopping has led many companies to provide real-time communications on their Web sites to facilitate human-to-human interaction between service representatives and customers. The current study analyzes the interface design of such Live Help functions. More specifically, it attempts to understand whether or not the implementation of Text-To-Speech (TTS) voice communication and 3D avatars in the user interface of Live Help affects consumers' views of their own interactions with a service person.A laboratory experiment was designed to empirically test the hypotheses that TTS voice communication and 3D avatars can significantly affect consumers' perceptions of presence and flow. A 2*3 full factorial design was used (assessing three options for the use of voice and text, and two options for the use of avatars). The results of the experiment demonstrate that the presence of TTS voice significantly increases consumers' perceptions of flow (a construct depicting a user's interaction with a computer as playful and exploratory), while 3D avatars enhance consumers' feelings of telepresence (a user's experience of seeming to be present in a remote environment by means of a communication medium). These findings offer practitioners guidelines on how to improve interface designs for real-time human-to-human communications on electronic commerce Web sites.
Moshe Vardi speaks out on the proof, the whole proof, and nothing but the proof
Authors: Winslett Marianne
Published: May 2006

Welcome to ACM SIGMOD Record's series of interviews with distinguished members of the database community. I'm Marianne Winslett, and I have here with me Moshe Vardi, who holds an endowed professorship at Rice University and is a former chair of their Computer Science Department. Before joining Rice, Moshe was a manager at IBM Almaden Research Center. Moshe is an ACM Fellow, a AAAI Fellow, a co-winner of the Goedel Prize, and a member of the U.S. National Academy of Engineering and the European Academy of Sciences. His research interests include databases, verification, complexity theory, and multi-agent systems, and his PhD is from the Hebrew University of Jerusalem. So Moshe, welcome!
Travelling through wormholes
Authors: Veríssimo Paulo E.
Published: May 2006

The evolution of distributed computing and applications has put new challenges on models, architectures and systems. To name just one, 'reconciling uncertainty with predictability' is required by today's simultaneous pressure on increasing the quality of service of applications, and on degrading the assurance given by the infrastructure.This challenge can be mapped onto more than one facet, such as time or security or others. In this paper we explore the time facet, reviewing past and present of distributed systems models, and making the case for the use of hybrid (vs. homogeneous) models, as a key to overcoming some of the difficulties faced when asynchronous models (uncertainty) meet timing specifications (predictability). The Wormholes paradigm is described as the first experiment with hybrid distributed systems models.
Cryptography as an operating system service
Authors: Keromytis Angelos D. , Wright Jason L. , Raadt Theo De , Burnside Matthew
Published: May 2006

Cryptographic transformations are a fundamental building block in many security applications and protocols. To improve performance, several vendors market hardware accelerator cards. However, until now no operating system provided a mechanism that allowed both uniform and efficient use of this new type of resource.We present the OpenBSD Cryptographic Framework (OCF), a service virtualization layer implemented inside the operating system kernel, that provides uniform access to accelerator functionality by hiding card-specific details behind a carefully designed API. We evaluate the impact of the OCF in a variety of benchmarks, measuring overall system performance, application throughput and latency, and aggregate throughput when multiple applications make use of it.We conclude that the OCF is extremely efficient in utilizing cryptographic accelerator functionality, attaining 95% of the theoretical peak device performance and over 800 Mbps aggregate throughput using 3DES. We believe that this validates our decision to opt for ease of use by applications and kernel components through a uniform API and for seamless support for new accelerators. Furthermore, our evaluation points to several bottlenecks in system and operating system design: data copying between user and kernel modes, PCI bus signaling inefficiency, protocols that use small data units, and single-threaded applications. We identify some of these limitations through a set of measurements focusing on application-layer cryptographic protocols such as SSL. We offer several suggestions for improvements and directions for future work. We provide experimental evidence of the effectiveness of a new approach which we call
operating system shortcutting.
Shortcutting can improve the performance of application-layer cryptographic protocols by 27% with very small changes to the kernel.
Working together to improve K-12 computer science education
Authors: Cutler Robb , Stephenson Chris
Published: May 2006

The on-going crisis in K-12 computer science education is now exacerbating pipeline issues at all educational levels. This session explores Computer Science Teachers Association's perspective on addressing the challenges facing K-12 computer science and how the solutions will the benefit both secondary and post-secondary education.
A laboratory based capstone course in computer security for undergraduates
Authors: O'Leary Mike
Published: May 2006

We describe a laboratory based capstone course in computer security for undergraduates. The course is based on a sequence of hands-on laboratory exercises for four teams of students. It emphasizes defensive tools and techniques at the expense of attacks; it also takes a network centered view where student teams set up and configure entire networks. In this paper, we describe the course, how it fits into the curriculum, and the laboratory facilities we have developed. We then present the details of some of our lab exercises, and discuss the lessons that we have learned.
A database security course on a shoestring
Authors: George Binto , Valeva Anna
Published: May 2006

Database security has paramount importance in industrial, civilian and government domains. Despite its importance, our search reveals that only a small number of database security courses are being offered. In this paper, we share our experience in developing and offering an undergraduate elective course on database security with limited resources. We believe that database security should be considered in its entirety rather than being component specific. Therefore, we emphasize that students develop and implement a database security plan for a typical real world application. In addition to the key theoretical concepts, students obtain hands-on experience with two popular database systems. We encourage students to learn independently making use of the documentation and technical resources freely available on the Internet. This way, our hope is that they will be able to adapt to emerging systems and application scenarios.
Teaching a web security course to practice information assurance
Authors: Yu H. , Liao W. , Yuan X. , Xu J.
Published: May 2006

This paper presents a hybrid teaching approach, a new Web Security course as well as how to use the hybrid approach to teach the Web Security course to practice information assurance. The hybrid teaching approach contains three key issues that are keeping the lecture materials up-to-date, assigning former research projects as comprehensive team projects, and connecting classroom knowledge with real world web applications. We have applied this approach to the teaching a Web Security course and achieved excellent results. Our experience exhibits that integrating education, research and web applications into the Web Security course to practice information assurance are essential for a sound security education. Using this approach instructors connect knowledge in the classroom to real world applications, attract students to the security area, and train students to become information assurance professionals.
A compiler tutorial scaled for the programming languages course
Authors: Mead Jerry
Published: May 2006

This paper describes the structure of two, self-paced, language-translation tutorials that integrate nicely into a principles-based undergraduate programming languages course, thus bringing material normally covered in a compiler course down into the context of a traditional programming languages course. The primary goal of the tutorials is to provide students with useful models for programming language principles as well as a very basic introduction to compiling techniques, including tokenizing, parsing, static semantic checking, and code generation. The paper also exposes a pedagogic technique of repeated exposure that drives the success of these tutorials.
Virtual machines - an idea whose time has returned
Authors: Bullers William I. , Burd Stephen , Seazzu Alessandro F.
Published: May 2006

Virtual machines provide a secure environment within which students may install, configure, and experiment with operating system, network, and database software. This paper describes experiences teaching three advanced courses in system and network administration, information security and assurance, and database administration using VMware workstation in a shared student laboratory. The paper describes benefits and challenges in course and lab configuration, security, and administration.
Thinking, speaking, and writing for freshmen
Authors: Osborne Lawrence J.
Published: May 2006

Our entering freshmen have little experience with the underlying concepts of computer science and information technology, and they are not familiar with the process of absorbing new information through listening and reading and cooperating with other well-trained individuals to increase their knowledge and skills in a subject. Simply making group assignments requiring research papers and presentations does not enable students to appreciate this process which is a characteristic of all fields of scientific inquiry today. Most of our upper division courses have team projects, but student culture resists effective teamwork. We have established a course for freshman entitled "Thinking, Speaking, and Writing in Computer Science" in which we try to lay the groundwork for group work in later classes by fostering a sense of interdependence among team members, accountability of individual students to the team in the form of preparation and completion of project tasks, frequent meetings to promote team goals, the development of social skills required for collaboration, and the value of group discussion of strategies in problem solving. Although the course has been in existence only two years, our department has observed that students are finding that following this approach to learning leads to improved academic performance, and that students are becoming more adept in learning skills as they realize the benefits that accrue from our approach to intelligent interaction with their peers and instructors.
Bridging writing to learn and writing in the discipline in computer science education
Authors: Hoffman Mark E. , Dansdill Timothy , Herscovici David S.
Published: May 2006

Writing in Computer Science education is typically writing to communicate to a professional audience--also known as "writing in the discipline." (WID) A few Computer Science educators have promoted "writing to learn" (WTL) for active learning. A gap exists between these two forms of writing that inhibits the general adoption of writing in Computer Science. We propose that "bridging" informal WTL assignments to formal disciplinary writing as a way of promoting general adoption of writing across all courses, thus improving thinking and writing skills for all Computer Science students. We include examples of assignments that bridge writing to learn and writing in the discipline.
A framework in which to teach (technical) communication to computer science majors
Authors: Etlinger Henry A.
Published: May 2006

We describe a framework in which to consider designing an entire course for Computer Science majors that covers both technical communications as well as more general communication issues. By utilizing abstraction, we're able to fashion a framework that allows instructors to design specific course elements that meet their needs or priorities. We take advantage of many other efforts reported upon in the past that discuss processes that students can follow in developing effective communication artifacts, blend writing or speaking assignments into individual courses, or talk about communication-intensive courses.
A systematic approach to active and cooperative learning in CS1 and its effects on CS2
Authors: Gonzalez Graciela
Published: May 2006

This paper presents a description of a course redesign to incorporate active and cooperative learning techniques into an Introduction to Programming course (CS1) in a systematic way that addresses all aspects of the course: delivery, management, and assessment. The primary goals of the experience were to improve student learning in CS1 and help students develop a support system. By increasing their competence and confidence, and helping them establish a working relationship with their peers, we sought to improve their persistence and performance in the program. We thus focus on student performance and retention through the follow-up class (CS2) as taught at Sam Houston State University. The results are encouraging. We observed that 70% of those students that had the Active Learning experience in CS1 end up getting a passing grade in CS2, with only 10% withdrawing (dropping or resigning), in contrast to a 44% passing rate and 25% withdrawal rate among those that took a regular CS1 class.
An evaluation method of project based learning on software development experiment
Authors: Matsuura Saeko
Published: May 2006

In recent years, it has been widely acknowledged that classes designed by utilizing PBL (Project-Based Learning) are effective in enhancing the problem-solving ability of university students. In PBL-based classes, students try to apply their knowledge to solve the problems by themselves; therefore, such classes are effective in improving problem-solving and communication abilities of students. However, it is difficult for a teacher to appropriately assess individual contributions in a group work such as PBL. Since 2002, we have been planning and conducting group-work-based software development experiments as an approach to PBL. This paper describes the manner in which the class was designed and conducted in order to evaluate the contribution of each individual student based on the degree of achievement of a goal in a group work. We propose an evaluation method based on an evaluation model of PBL and discuss the trial results.
Bioinformatics and computing curriculum
Authors: Fetrow Jacquelyn S. , John David J.
Published: May 2006

An interdisciplinary bioinformatics course has been taught at Wake Forest for three semesters. Undergraduate and graduate students from multiple academic specialties are brought together in a single classroom. In addition to focusing on traditional bioinformatics topics, this course concentrates on interdisciplinary collaboration in the in-class exercises and the research-based course project. A team of faculty from complementary disciplines teach the course. Productive communication is one key goal of this course.
Learning strategies and undergraduate research
Authors: Polack-Wahl Jennifer A. , Anewalt Karen
Published: May 2006

Undergraduate students often lack the skills necessary to conduct independent research. In order to improve students' skills in research, the Computer Science department at the University of Mary Washington has designed and offered a course in research methods. The course teaches students about learning strategies that they can apply across the computing discipline and beyond. This paper describes the process that was used to create a new research methods course, the details related to the first offering of the course, and findings on how the course changed students' perception of research.
CSE volunteers
Authors: Christensen K. , Rundus D. , Perera G. , Zulli S.
Published: May 2006

Service-learning enables computer science and engineering students to apply and refine their technical skills, learn new soft skills, and make a contribution to their community. At the University of South Florida we have organized a group of computer science and engineering students, called the CSE Volunteers, to provide IT support to the Hillsborough County School District. In spring 2005 over 7% of our undergraduate students voluntarily served in this program. While the work is fairly low-level, the experience for the students and school district has been very positive. Future directions include quantitative assessment, tackling projects of greater complexity, seeking corporate funding, and applying this program to help recruit new students to the major.
An undergraduate course on software bug detection tools and techniques
Authors: Larson Eric
Published: May 2006

The importance of software bug detection tools is high with the constant threat of malicious activity. Companies are increasingly relying on software bug detection tools to catch exploitable bugs before the program is released. This paper describes a course on software bug detection techniques that is aimed at undergraduates. Courses in software verification are often taught at the graduate level and too theoretical and research oriented for undergraduates. A key component of the course is the programming assignments where students gain practical experience in creating their own software bug detection tools using a source to source converter for a subset of C++.
A project in algorithms based on a primary historical source about catalan numbers
Authors: Pengelley David , Pivkina Inna , Ranjan Desh , Villaverde Karen
Published: May 2006

We discuss a project based on an original source from 1838 by Gabriel Lamé, which was used to teach dynamic programming in an Algorithms and Data Structures course for junior level computer science students. The project was developed as part of a group effort at New Mexico State University on using original historical sources in teaching. The project is based on an excerpt from a letter of Monsieur Lamé to Monsieur Liouville on the question: Given a convex polygon, in how many ways can one partition it into triangles by means of diagonals? A variety of tasks in the project, which includes reading, writing, proving statements by mathematical induction, deriving formulas, writing computer programs and analyzing and comparing them for efficiency, help students to develop verbal, analytical and discrete mathematics skills necessary for computer science. We also discuss student reactions to the project and to learning from historical sources.
Using market basket analysis to integrate and motivate topics in discrete structures
Authors: Wick Michael R. , Wagner Paul J.
Published: May 2006

Nearly every computer science curriculum includes a course called "Discrete Structures" or "Discrete Mathematics". Over the past few years, considerable attention has been paid to this course in an attempt to overcome the misperception by students that the material is mathematics and not related to computer science. Most of these efforts deal with attempting to explicitly show students the application of discrete mathematics within computer science. We present an application that adds to the efforts of this community by giving instructors a modern, powerful, and elegant example to motivate student engagement in discrete structures.
Turning automata theory into a hands-on course
Authors: Rodger Susan H. , Bressler Bart , Finley Thomas , Reading Stephen
Published: May 2006

We present a hands-on approach to problem solving in the formal languages and automata theory course. Using the tool JFLAP, students can solve a wide range of problems that are tedious to solve using pencil and paper. In combination with the more traditional theory problems, students study a wider-range of problems on a topic. Thus, students explore the formal languages and automata concepts computationally and visually with JFLAP, and theoretically without JFLAP. In addition, we present a new feature in JFLAP, Turing machine building blocks. One can now build complex Turing machines by using other Turing machines as components or building blocks.
Qualitative research in computer science education
Authors: Hazzan Orit , Dubinsky Yael , Eidelman Larisa , Sakhnini Victoria , Teif Mariana
Published: May 2006

This paper discusses the suitability of the qualitative research approach to computer science education research. It is based on the following two observations: First, only a small proportion of works presented in the computer science education literature contain some experimental component (Fincher and Petre, 2004; Valentine, 2004). Second, those research works conducted in computer science education that do, usually employ a quantitative research approach. This paper focuses on the qualitative research approach, presenting its nature, discussing its relationships to the quantitative research approach and addressing its application in general and in the context of computer science education in particular.
The evolution of a computational outreach program to secondary school students
Authors: Dodds Zachary , Karp Leslie
Published: May 2006

This paper tracks the five-year growth and current trajectory of a computational outreach program at a small, liberal-arts college. The program has enhanced opportunities for talented high-school students to experience computation more deeply than their HS curriculum currently offers. This outreach evolved from a naive initial premise into a mutually beneficial interaction between an undergraduate computer science department and a local secondary school. The most important factor in the program's sustainability is a supportive liaison within the high school's administration. We hope the lessons we have learned will help other CS departments develop sustainable outreach programs.
Teaching the power of randomization using a simple game
Authors: Kortsarts Yana , Rufinus Jeffrey
Published: May 2006

Any deterministic algorithm can be viewed as a game between the algorithm player and the input player. A randomized algorithm can be viewed as a mixed strategy for the first player, used to minimize the disadvantage of being the first to reveal its move. We suggest a simple and accessible guessing game that can serve as both a way to explain notions in algorithms (like worst case input) to students and also to illustrate the power of randomization, presented in an intuitive way.
Relationship of early programming language to novice generated design
Authors: Chen Tzu-Yi , Monge Alvaro , Simon Beth
Published: May 2006

What measurable effect do the language and paradigm used in early programming classes have on novice programmers' ability to do design? This work investigates the question by using data collected from 136 "first competency" students as part of a multi-national, multi-institutional study of students' approach to and attitudes toward design. Analysis of a number of surface characteristics of their designs found strikingly few differences between designs produced by students at schools that teach using objects-early, imperative-early, and functional-early paradigms. A similar lack of difference was found between students at C++-first and Java-first schools. While statistically significant differences are found for three characteristic comparisons across language and paradigm, these results seem to have little meaning for teaching given the complexity of the null hypotheses tested in those three cases. In particular, for the following design characteristics no statistically significant differences across language or paradigm of early instruction were found: attempt to address requirements, type of design produced, number of parts in design, recognition of ambiguity in design, and connectedness of design.
Case-based analysis
Authors: Quinn Michael J.
Published: May 2006

Case-based analysis is a bottom-up methodology for ethical reasoning. In a teaching environment, it can be a useful alternative to top-down methods, such as Kantianism, utilitarianism, rights-based theories, and virtue ethics. We describe a methodology for case-based analysis and illustrate the methodology by evaluating three test cases in the areas of Internet etiquette, intellectual property, and privacy, respectively. We summarize the strengths and weaknesses of using the case-based approach in a classroom setting.
Computing in context
Authors: Martin Fred G. , Kuhn Sarah
Published: May 2006

A hands-on embedded computing project is introduced into an undergraduate social sciences course. In the pilot module, nine student teams created working prototypes, using the technology to address social, ecological and ethical issues. The teams included freshman to senior level computer science majors, other technical majors, and non-technical students. Most students became highly engaged in the activity, developed exciting ideas, and reported improved learning in the social sciences.
A data mining course for computer science
Authors: Musicant David R.
Published: May 2006

An undergraduate elective course in data mining provides a strong opportunity for students to learn research skills, practice data structures, and enhance their understanding of algorithms. I have developed a data mining course built around the idea of using research-level papers as the primary reading material for the course, and implementing data mining algorithms for the assignments. Such a course is accessible to students with no prerequisites beyond the traditional data structures course, and allows students to experience both applied and theoretical work in a discipline that straddles multiple areas of computer science. This paper provides detailed descriptions of the readings and assignments that one could use to build a similar course.
Compile-time area estimation for LUT-based FPGAs
Authors: Kulkarni Dhananjay , Najjar Walid A. , Rinker Robert , Kurdahi Fadi J.
Published: May 2006

The Cameron Project has developed a system for compiling codes written in a high-level language called SA-C, to FPGA-based reconfigurable computing systems. In order to exploit the parallelism available on the FPGAs, the SA-C compiler performs a large number of optimizations such as full loop unrolling, loop fusion and strip-mining. However, since the area on an FPGA is limited, the compiler needs to know the effect of compiler optimizations on the FPGA area; this information is typically not available until after the synthesis and place and route stage, which can take hours. In this article, we present a compile-time area estimation technique to guide SA-C compiler optimizations. We demonstrate our technique for a variety of benchmarks written in SA-C. Experimental results show that our technique predicts the area required for a design to within 2.5% of actual for small image processing operators and to within 5.0% for larger benchmarks. The estimation time is in the order of milliseconds, compared with minutes for the synthesis tool.
Supporting complex queries on multiversion XML documents
Authors: Chien Shu-Yao , Tsotras Vassilis J. , Zaniolo Carlo , Zhang Donghui
Published: May 2006

Managing multiple versions of XML documents represents a critical requirement for many applications. Recently, there has been much work on supporting complex queries on XML data (e.g., regular path expressions, structural projections, etc.). In this article, we examine the problem of implementing efficiently such complex queries on multiversion XML documents. Our approach relies on a numbering scheme, whereby durable node numbers (DNNs) are used to preserve the order among the nodes of the XML tree while remaining invariant with respect to updates. Using the document's DNNs, we show that many complex queries are reduced to combinations of
range version retrieval
queries. We thus examine three alternative storage organizations/indexing schemes to efficiently evaluate range version retrieval queries in this environment. A thorough performance analysis is then presented to reveal the advantages of each scheme.