bluuebunny/crossref_metadata_2025 huggingface dataset:
Disturbance regime of a cold temperate forest as deduced from tree-ring patterns: the Tantaré Ecological Reserve, Quebec
Authors: Payette Serge , Filion Louise , Delwaide Ann
Published: June 2008

The recent history and disturbance regime of an old-growth sugar maple – yellow birch forest located in the Tantaré Ecological Reserve, Québec, were determined using tree-ring growth patterns of individual trees that had undergone suppression and release. Within a sampling quadrat (0.25 ha) where all living and dead trees were mapped, the age, size, and spatial pattern of gaps formed since the mid-19th century were inferred from tree-ring signatures of standing trees. From 1860 onwards, more than 30 gaps of various form and size occurred, most gaps being < 200 m2 and covering a total area of 3775 m2. During the 1930–1985 period, the tree-fall frequency was 0.45 per year, the tree fall free interval was 3.2 years, and the tree-fall rotation period (turnover rate) was estimated to be 45 years. The rather short life-span of most trees (<125 years) may be attributed to the cool and humid conditions prevailing at the site, which stimulated self-pruning of mature trees. The spatiotemporal development of the sugar maple forest has been active during the past 2 centuries through small-scale disturbances associated with successve, often overlapping, single and multiple tree falls. This situation explains the uneven age distribution of sugar maple and yellow birch populations subjected to differential survival conditions caused by gap dynamics. It is concluded that tree-ring patterns corresponding to periods of suppression and release will likely give a finer resolution record of gap dynamics than other methods of determining natural disturbance regime and reconstruction of recent stand history.
BASE-POINT-FREE PENCILS ON TRIPLE COVERS OF SMOOTH CURVES
Authors: SHIN DONGSOO
Published: June 2008

Let X be a smooth algebraic curve. Suppose that there exists a triple covering f: X → Y where Y is a smooth algebraic curve. In this paper, we investigate the existence of morphisms from X to the projective line P1 which do not factor through the covering f. For this purpose, we generalize the classical results of Maroni concerning base-point-free pencils on trigonal curves to the case of triple covers of arbitrary smooth irrational curves.
SYMPLECTIC ALTERNATING ALGEBRAS
Authors: TRAUSTASON GUNNAR
Published: June 2008

This paper begins the development of a theory of what we will call symplectic alternating algebras. They have arisen in the study of 2-Engel groups but seem also to be of interest in their own right. The main part of the paper deals with the challenging classification of some algebras of this kind which arise in the context of 2-Engel groups and give some new information about these groups. The main result is that there are 31 such algebras with dimension 6 over the field of three elements.
POLYNOMIAL CLONES ON SQUAREFREE GROUPS
Authors: MAYR PETER
Published: June 2008

We prove that, on a set of size n, the number of clones that contain a group operation and all constant functions is finite if n is squarefree. This confirms a conjecture by Paweł Idziak from [5] where the converse implication was shown. Our result follows from the observation that the polynomial clone of an expansion of a squarefree group is uniquely determined by its binary functions. We also note that, in general, such a clone is not determined by the congruence lattice and the commutator operation of the corresponding algebra. This refutes a second conjecture from [5].
HANDLING AMBIGUOUS VALUES IN INSTANCE-BASED CLASSIFIERS
Authors: HOLLAND HANS , KUBAT MIROSLAV , ŽIŽKA JAN
Published: June 2008

In an attempt to automate evaluation of network intrusion detection systems, we encountered the problem of ambiguously described learning examples. For instance, an attribute's value, or a class label, in a given example was known to be a or b but definitely not c or d. Previous research in machine learning usually either “disambiguated” the value (by giving preference to a or b), or replaced it with a “don't-know” symbol. Neither approach is satisfactory: while the former distorts the available information by pretending precise knowledge, the latter ignores the fact that at least something is known. Our experiments confirm the intuition that classification performance is indeed impaired if the ambiguities are not handled properly. In the research reported here, we limited ourselves to the realm of the relatively simple nearest-neighbor classifiers and investigated a few alternative solutions. The paper describes the techniques we used and describes their behavior in experimental domains.
RANDOM SUBSETS SUPPORT LEARNING A MIXTURE OF HEURISTICS
Authors: PETROVIC SMILJANA , EPSTEIN SUSAN L.
Published: June 2008

Problem solvers, both human and machine, have at their disposal many heuristics that may support effective search. The efficacy of these heuristics, however, varies with the problem class, and their mutual interactions may not be well understood. The long-term goal of our work is to learn how to select appropriately from among a large body of heuristics, and how to combine them into a mixture that works well on a specific class of problems. The principal result reported here is that randomly chosen subsets of heuristics can improve the identification of an appropriate mixture of heuristics. A self-supervised learner uses this method here to learn to solve constraint satisfaction problems quickly and effectively.
KNOWLEDGE TRANSFER IN DEEP CONVOLUTIONAL NEURAL NETS
Authors: GUTSTEIN STEVEN , FUENTES OLAC , FREUDENTHAL ERIC
Published: June 2008

Knowledge transfer is widely held to be a primary mechanism that enables humans to quickly learn new complex concepts when given only small training sets. In this paper, we apply knowledge transfer to deep convolutional neural nets, which we argue are particularly well suited for knowledge transfer. Our initial results demonstrate that components of a trained deep convolutional neural net can constructively transfer information to another such net. Furthermore, this transfer is completed in such a way that one can envision creating a net that could learn new concepts throughout its lifetime.

The experiments we performed involved training a Deep Convolutional Neural Net (DCNN) on a large training set containing 20 different classes of handwritten characters from the NIST Special Database 19. This net was then used as a foundation for training a new net on a set of 20 different character classes from the NIST Special Database 19. The new net would keep the bottom layers of the old net (i.e. those nearest to the input) and only allow the top layers to train on the new character classes. We purposely used small training sets for the new net to force it to rely as much as possible upon transferred knowledge as opposed to a large and varied training set to learn the new set of hand written characters. Our results show a clear advantage in relying upon transferred knowledge to learn new tasks when given small training sets, if the new tasks are sufficiently similar to the previously mastered one. However, this advantage decreases as training sets increase in size.
Value-at-Risk Efficient Portfolio Selection Using Goal Programming
Authors: Chen Hsin-Hung
Published: June 2008

The purpose of this study is to apply polynomial goal programming to establish a new portfolio selection model that considers the tradeoffs between expected return and Value-at-Risk (VaR) of portfolios and the flexibility of incorporating investor's preferences. The historical data of 10 international stock markets of Pacific Rim countries were used in the empirical analysis. The results showed that the proposed model demonstrated the ability to resolve the problems of a traditional asset allocation model. The validity and fitness of the proposed model were confirmed.
Dividend Initiations by High-Tech Firms
Authors: Lacina Michael , Zhang Zhaohui
Published: June 2008

We study the stock price and trading volume reactions to dividend initiations by high-tech firms relative to those by non-high tech firms. We find significant positive cumulative abnormal returns and abnormal trading volume for both high-tech and non-high tech firms surrounding dividend initiations. However, when we control for variables such as size and dividend yield, stock returns and trading volume around dividend initiations are higher for high-tech firms than for non-high tech firms. We also find evidence that stock returns and trading volume for high-tech firms are higher with increases in liquid assets, although the volume reaction to increases in liquid assets is stronger than the return reaction, perhaps indicating clientele shifts. Overall, our findings convey stronger investor reaction to dividend initiations by high-tech firms, especially those with sufficient liquid assets.
The Dynamics of Trades and Quote Revisions Across Stock, Futures, and Option Markets
Authors: Kang Jangkoo , Park Hyoung-Jin
Published: June 2008

This paper examines the dynamics of returns and order imbalances across the KOSPI 200 cash, futures and option markets. The information effect is more dominant than the liquidity effect in these markets. In addition, returns have more predictability power for the future movements of prices than order imbalances. Information seems to be transmitted more strongly from derivative markets to their underlying asset markets than from the underlying asset markets to their derivative markets. Finally, domestic institutional investors prefer futures, domestic individual investors prefer options, and foreign investors prefer stocks relative to other investor groups when they have new information.
Efficient Market Hypothesis (EMH): Past, Present and Future
Authors: Yen Gili , Lee Cheng-few
Published: June 2008

In this survey article, after delineating its historical origin of the Efficient Market Hypothesis (EMH), the authors summarize from the methodological perspective the empirical findings from 1960s through 1990s bearing on the EMH under the headings "supporting empirical findings as documented in 1960s", "mixed empirical findings as merged in the late 1970s through 1980s" and "challenging empirical findings as appeared in 1990s". The authors move on to sketch the ongoing debate in the 21st century based on empirical evidence available and then present an overall assessment of the EMH. Once necessary reservations and precautious interpretations are taken into consideration, the authors contend at the end of the article that the EMH is here to stay and will continue to play an important role in modern finance for years to come.
EMPIRICAL INVARIANCE PRINCIPLE FOR ERGODIC TORUS AUTOMORPHISMS: GENERICITY
Authors: DURIEU OLIVIER , JOUAN PHILIPPE
Published: June 2008

We consider the dynamical system given by an algebraic ergodic automorphism T on a torus. We study a Central Limit Theorem for the empirical process associated to the stationary process (f◦Ti)i∈ℕ, where f is a given ℝ-valued function. We give a sufficient condition on f for this Central Limit Theorem to hold.

In the second part, we prove that the distribution function of a Morse function is continuously differentiable if the dimension of the manifold is at least three and Hölder continuous if the dimension is one or two. As a consequence, the Morse functions satisfy the empirical invariance principle, which is therefore generically verified.
SELF-DUALITY OF HARADA RING OF A COMPONENT TYPE
Authors: BABA YOSHITOMO
Published: June 2008

We define Harada rings of a component type. The class of them contains indecomposable serial rings. We consider the structure of them and show that they have weakly symmetric self-dualities.
QUANTUM MECHANICAL DESCRIPTION OF THE INTERACTIONS BETWEEN DNA AND 9,10-ANTHRAQUINONE
Authors: RIAHI SIAVASH , GANJALI MOHAMMAD REZA , NOROUZI PARVIZ
Published: June 2008

Molecular geometries of the 9,10-anthraquinone (AQ) and DNA bases (Adenine, Guanine, Cytosine, and Thymine) were optimized using B3LYP/6-31G** method. Properties of isolated intercalator (9,10-anthraquinone) and their stacking interactions with adenine ⋯ thymine (AT) and guanine ⋯ cytosine (GC) nucleic acid base pairs were investigated by means of DFTB method. DFTB method, an approximate version of the DFT method, was extended to cover London dispersion energy. AQ exhibits a large charge delocalization and it has no site with dominant charge. This intercalator has a large polarizability and is a good electron acceptor, while base pairs are good electron donors. B3LYP/6-31G** stabilization energies of intercalator ⋯ base pair complexes are large (-18.83 kcal/mol for AT ⋯ AQ and -15.69 kcal/mol for GC ⋯ AQ). It is concluded that, the dispersion energy predominantly contributes to the stability of intercalator ⋯ DNA base pair complexes. Any procedure which does not cover dispersion energy is thus not suitable for studying the process of intercalation. The results showed that AQ changes the structure of DNA on bond length, bond angle, torsion angle, and charges.
VARIATIONAL ELECTROSTATICS FOR CHARGE SOLVATION
Authors: WANG ZHEN-GANG
Published: June 2008

We show that the equations of continuum electrostatics can be obtained entirely and simply from a variational free energy comprising the Coulomb interactions among all charged species and a spring-like term for the polarization of the dielectric medium. In this formulation, the Poisson equation, the constitutive relationship between polarization and the electric field, as well as the boundary conditions across discontinuous dielectric boundaries, are all natural consequences of the extremization of the free energy functional. This formulation thus treats the electrostatic equations and the energetics within a single unified framework, avoiding some of the pitfalls in the study of electrostatic problems. Application of this formalism to the nonequilbrium solvation free energy in electron transfer is illustrated. Our calculation reaffirms the well-known result of Marcus. We address the recent criticisms by Li and coworkers who claim that the Marcus result is incorrect, and expose some key mistakes in their approach.
THEORETICAL STUDIES ON THE COUPLING INTERACTIONS AND SELF-EXCHANGE REACTION MECHANISMS IN THE COMPLEXES OF NO WITH ONH AND NOH
Authors: LI PING , XIE XIAOYAN , BU YUXIANG , WANG WEIHUA , WANG NANA , SHI JUNYOU , MOU ZHAOXIA
Published: June 2008

The coupling interactions and self-exchange reaction mechanisms between NO and ONH (NOH) have been systematically investigated at the B3LYP/6-311++G** level of theory. All the equilibrium complexes are characterized by the intermolecular H-bonds and co-planar geometries. The cisoid NOH/ON species is the most stable one among all the complexes considered due to the formation of an N – N bond. Moreover, all the cisoid complexes are found to be more stable than the corresponding transoid ones. The origin of the blueshifts occurring in the selected complexes has been explored, employing the natural bond orbital (NBO) calculations. Additionally, the proton transfer mechanisms for the self-exchange reactions have been proposed, i.e. they can proceed via the three-center proton-coupled electron transfer or five-center cyclic proton-coupled electron transfer mechanism.
CARBON-SUBSTITUTING IN (4,4) BORON NITRIDE NANOTUBE: DENSITY FUNCTIONAL STUDY OF BORON-11 AND NITROGEN-14 ELECTRIC FIELD GRADIENT TENSORS
Authors: SEIF AHMAD , BOSHRA ASADOLLAH , MIRZAEI MAHMOUD , AGHAIE MEHRAN
Published: June 2008

Density functional theory (DFT) study is performed to investigate the influence of carbon substituting in a representative model of armchair boron nitride nanotubes (BNNTs). To this aim, the electric field gradient (EFG) tensors at the sites of11B and11N nuclei are calculated in two models of (4,4) single-walled BNNT. Model one (raw) consists of 36 B and 36 N atoms with 12 saturating H atoms of two mouths while 7 B and 7 N atoms are substituted by 14 C atoms like a wire in model two ( C -substituted). The converted EFG tensors to measurable nuclear quadrupole resonance (NQR) parameters, quadrupole coupling constant (CQ) and asymmetry parameter (ηQ), reveal that the CQvalues in the length of raw BNNT are divided into some layers with equal magnitude and among them the mouth layers have the largest CQmagnitudes. In the C -substituted model, in addition to the mouth layers, the CQof those B and N nuclei directly bonded to C atoms are increased to the magnitudes as large as those mouth nuclei meaning that the active sites are increased in the C -substituted BNNT model. It is worth noting that the NQR parameters of other nuclei rather than those directly bonded to C and also those in the first neighborhood of C atoms are almost in equal values in the two models. Comparing the results with a recent study on zigzag BNNT (Mirzaei M et al., Z. Naturforsch A62:56, 2007) reveals that armchair and zigzag BNNTs show almost similar electronic properties. However, there is a significant difference in the electronic properties of those B and N atoms located at the mouth of the two BNNTs whose mouths are similar in armchair, whereas there are two different mouths ( B -mouth and N -mouth) in zigzag BNNT.
A PREDICTIVE CYTOCHROME P450 MONOOXYGENASE FUNCTIONAL MODEL FOR GENERIC HYDROXYLATION BYRHIZOPUS ORYZAEATCC 11145
Authors: MARTIN GLENROY D. A. , DURRANT MARCUS C. , REESE PAUL B.
Published: June 2008

An active site model for generic hydroxylation of xenobiotes by the fungus Rhizopus oryzae ATCC 11145 has been developed. The model was constructed using data from known metabolites of R. oryzae, as reported in the chemical literature, including diterpenes and steroids. The model takes the form of an irregular polyhedron of 340 Å3volume, with two hydrophilic patches and an active site region. It was validated using data for other known substrates, including terpenes, steroids, octalin, and hydrindenone derivatives, drawn from the literature. The interpretive and predictive abilities of the model are discussed.
SEEKING ADVICE IN A DYNAMIC AND COMPLEX BUSINESS ENVIRONMENT: IMPACT ON THE SUCCESS OF SMALL FIRMS
Authors: DYER LINDA M. , ROSS CHRISTOPHER A.
Published: June 2008

The research explored the antecedents and outcomes of seeking information and advice about the marketplace in which a small firm exists. A survey of 185 small business owners suggested that both operating in a dynamic environment and having complex marketing activities had a direct link to the frequency with which the small business owner sought marketplace information and advice. Marketplace advice seeking, in turn, was positively correlated with owners' perceptions of business performance. The usefulness of the findings for owners and business-support advisors was discussed.
EXPLORING THE NATURE AND IMPACT OF GESTATION-SPECIFIC HUMAN CAPITAL AMONG NASCENT ENTREPRENEURS
Authors: DIOCHON MONICA , MENZIES TERESA V. , GASSE YVON
Published: June 2008

This article explores the nature and impact of gestation-specific human capital on successful start-up among a random sample of Canadian nascent entrepreneurs. Although much is known about the relationship between individual-level factors and the probability of becoming a nascent entrepreneur, the same cannot be said for the relationship between individual-level factors and success in starting a business. Previous studies of existing business founders indicate that general human capital (education and work experience) plays a role in opportunity identification, but at best plays a very weak role in opportunity pursuit. In light of these findings we sought to identify elements of human capital that would be specific to gestation–previous start-up experience, completion of classes or workshops in starting a business, and financial management capability (FMC). In documenting these elements, we found the majority of the sample had not taken any classes or workshops on starting a business, were novices to the start-up process, and were characterized by a wide range of financial management capability. Among those nascent entrepreneurs who succeeded in starting a business, FMC was found to be associated with sustainability. We conclude by discussing implications for researchers.
FINANCIAL FUNDING OF IMMIGRANT BUSINESSES
Authors: KUSHNIROVICH NONNA , HEILBRUNN SIBYLLE
Published: June 2008

This study investigates differences in financial funding between immigrant and non-immigrant businesses and delineates factors influencing financial funding of immigrant businesses. Data for the study were collected in Israel between 2000 and 2005. By combining convenient and snowball samples, 214 native Israelis and 153 FSU immigrant entrepreneurs answered a questionnaire. We classified financial sources for immigrant businesses according to their affiliation to the ethnic community, and according to their relation to official financial institutions. Our study revealed that the scope of funding of immigrant businesses is significantly smaller than that of non-immigrant businesses. Immigrant entrepreneurs are more likely to finance their businesses from informal sources but they use fewer loans from family and friends than non-immigrant entrepreneurs. We found that immigrant entrepreneurs who deal with co-ethnic clients do not use more ethnic sources of capital for financing their businesses: the share of co-ethnic clients does not influence the ratio of ethnic financial sources for both setting up and expanding immigrant businesses. Our study revealed that governmental support in the terms of designated loans is the most salient factor influencing financial funding of immigrant businesses. The results suggest important implications for public policy.
ECONOMIC FREEDOM AND THE SUCCESS OF MICROFINANCE INSTITUTIONS
Authors: CRABB PETER
Published: June 2008

This study looks at the relationship between the success of microfinance institutions and the degree of economic freedom in their host countries. Many microfinance institutions are currently not self-sustaining, and both theoretical and empirical work suggests that the economic environment in which they operate is an important factor in their ability to reach this goal, furthering the mission of outreach to the poor. The sustainability of the microfinance institutions is analyzed here using a large cross-section of institutions and countries. The results show that microfinance institutions operate primarily in countries with a relatively low degree of overall economic freedom and that government intervention in the economy can reduce their sustainability.
BREATHING SHOES AND COMPLEMENTARITIES: STRATEGIC INNOVATION IN A MATURE INDUSTRY
Authors: CAMUFFO ARNALDO , FURLAN ANDREA , ROMANO PIETRO , VINELLI ANDREA
Published: June 2008

This paper tells the story of Geox, an Italian footwear manufacturer that, in less than a decade, has become one of the world's largest shoe manufacturers. Applying the related notions of complementarity and performance landscape to study strategic positioning in the footwear industry, we show that, though grounded on product innovation (the original Geox breathes®patented system which allows ventilation in waterproof rubber sole), Geox's competitive advantage has not grown out of operational excellence in single activities in the business, but, rather, derives from a unique and consistent configuration of complementary activities. Such configuration represents an innovative strategic position and corresponds to a peak in the footwear industry performance landscape. The case study offers anecdotal evidence in support of complementarity based economic theory. It confirms that, in the presence of complementarities, rivals find strategy imitation and reverse engineering difficult due to the unique nature of the relationships among complementary variables.
A basis for information retrieval in context
Authors: Melucci Massimo
Published: June 2008

Information retrieval (IR) models based on vector spaces have been investigated for a long time. Nevertheless, they have recently attracted much research interest. In parallel, context has been rediscovered as a crucial issue in information retrieval. This article presents a principled approach to modeling context and its role in ranking information objects using vector spaces. First, the article outlines how a basis of a vector space naturally represents context, both its properties and factors. Second, a ranking function computes the probability of context in the objects represented in a vector space, namely, the probability that a contextual factor has affected the preparation of an object.
Unified relevance models for rating prediction in collaborative filtering
Authors: Wang Jun , de Vries Arjen P. , Reinders Marcel J. T.
Published: June 2008

Collaborative filtering aims at predicting a user's interest for a given item based on a collection of user profiles. This article views collaborative filtering as a problem highly related to information retrieval, drawing an analogy between the concepts of users and items in recommender systems and queries and documents in text retrieval.

We present a probabilistic user-to-item relevance framework that introduces the concept of relevance into the related problem of collaborative filtering. Three different models are derived, namely, auser-based, anitem-based, and aunified relevance model, and we estimate their rating predictions from three sources: the user's own ratings for different items, other users' ratings for the same item, and ratings from different but similar users for other but similar items.

To reduce the data sparsity encountered when estimating the probability density function of the relevance variable, we apply the nonparametric (data-driven) density estimation technique known as theParzen-window method(or kernel-based density estimation). Using a Gaussian window function, the similarity between users and/or items would, however, be based on Euclidean distance. Because the collaborative filtering literature has reported improved prediction accuracy when using cosine similarity, we generalize the Parzen-window method by introducing aprojection kernel.

Existing user-based and item-based approaches correspond to two simplified instantiations of our framework. User-based and item-based collaborative filterings represent only a partial view of the prediction problem, where the unified relevance model brings these partial views together under the same umbrella. Experimental results complement the theoretical insights with improved recommendation accuracy. The unified model is more robust to data sparsity because the different types of ratings are used in concert.
Assessing multivariate Bernoulli models for information retrieval
Authors: Losada David E. , Azzopardi Leif
Published: June 2008

Although the seminal proposal to introduce language modeling in information retrieval was based on a multivariate Bernoulli model, the predominant modeling approach is now centered on multinomial models. Language modeling for retrieval based on multivariate Bernoulli distributions is seen inefficient and believed less effective than the multinomial model. In this article, we examine the multivariate Bernoulli model with respect to its successor and examine its role in future retrieval systems. In the context of Bayesian learning, these two modeling approaches are described, contrasted, and compared both theoretically and computationally. We show that the query likelihood following a multivariate Bernoulli distribution introduces interesting retrieval features which may be useful for specific retrieval tasks such as sentence retrieval. Then, we address the efficiency aspect and show that algorithms can be designed to perform retrieval efficiently for multivariate Bernoulli models, before performing an empirical comparison to study the behaviorial aspects of the models. A series of comparisons is then conducted on a number of test collections and retrieval tasks to determine the empirical and practical differences between the different models. Our results indicate that for sentence retrieval the multivariate Bernoulli model can significantly outperform the multinomial model. However, for the other tasks the multinomial model provides consistently better performance (and in most cases significantly so). An analysis of the various retrieval characteristics reveals that the multivariate Bernoulli model tends to promote long documents whose nonquery terms are informative. While this is detrimental to the task of document retrieval (documents tend to contain considerable nonquery content), it is valuable for other tasks such as sentence retrieval, where the retrieved elements are very short and focused.
Your attention, please
Authors: Roman David
Published: June 2008

The redesigned CACM Web site will deliver exactly what you want.
Cloud computing
Authors: Hayes Brian
Published: June 2008

As software migrates from local PCs to distant Internet servers, users and developers alike go along for the ride.
Quantum computing
Authors: Ross Michael , Oskin Mark
Published: June 2008

Researchers are optimistic, but a practical device is years away.
In search of dependable design
Authors: Hoffman Leah
Published: June 2008

How can software and hardware developers increase the reliability of their designs?
Legally SpeakingRevisiting patentable subject matter
Authors: Samuelson Pamela
Published: June 2008

Is everything under the sun made by humans patentable subject matter?
Kode ViciousBeautiful code exists, if you know where to look
Authors: Neville-Neil George V.
Published: June 2008

Coding is his game, pleasantries distained
Point/CounterpointTechnology curriculum for the early 21st century
Authors: Andriole Stephen J. , Roberts Eric
Published: June 2008

In case you missed IT, the world has changed.
InterviewThe 'art' of being Donald Knuth
Authors: Knuth Donald
Published: June 2008

In this first of a two-part talk, the renowned scholar and computer scientist reflects on the influences that set the course for his extraordinary career.
Beyond relational databases
Authors: Seltzer Margo
Published: June 2008

There is more to data access than SQL.
Q&ATalking model-checking technology
Authors: Hoffman Leah
Published: June 2008

A conversation with the 2007 ACM A.M. Turing Award winners
SIGWEB annual report
Authors: Munson Ethan V.
Published: June 2008

I want to take a few moments to bring you up-to-date on the state of SIGWEB. I'll be making a formal report to the membership at our annual meeting on June 19 in Pittsburgh, USA, which will be during the Hypertext 2008 conference, and also right at the end of the JCDL 2008 conference.
Hypertext 2007 conference review
Authors: Chin Alvin , Goulding James
Published: June 2008

From September 10 to 12, 2007, over 100 attendees convened in Manchester, England, travelling from all over Europe, as well as the far climes of North America, Asia and Australia. Unlike many visitors to Manchester they weren't here to witness the city's much heralded football team, but had gathered instead at the University of Manchester for the 18th International Conference on Hypertext and Hypermedia (Hypertext 2007). Here they would discuss recent innovations in hypertext, whose most famous form exists as the World Wide Web, and assess the challenges and opportunities in the latest groundbreaking research. Traditionally the success of the Hypertext conference series has been attributed to its immense diversity, and this year was no different, with papers being divided into 5 varied tracks: Hypertext and the Person; Hypertext and Society; Practical Hypertext; Hypertext Culture and Communication; and Hypertext Models and Theory. The conference was a vibrant affair that featured 16 full papers and 7 short papers (with a 29% overall acceptance rate), posters, demos, keynotes, panels, Birds-of-a-Feather (BOFs) and social events. However, what characterized this year's conference the most was an underlying sense of reintegration, a rejoining of disparate trends in hypertext to common goals. And as such a lot of unity and camaraderie too.
Wanted
Authors: Harper Simon
Published: June 2008

It's been a year now since starting and editing SIGWEB Quarterly and it is now time to pass on the mantle to another volunteer! Darren Lunn our current Media Manager has agreed to step up to the plate, and so now we need a volunteer to run the SIGWEB Website under the direction of Yeliz Yesilada, the SIGWEB Information Director. DO YOU HAVE WHAT IT TAKES?
Interview with Mark Bernstein
Authors: Atzenbeck Claus
Published: June 2008

Mark Bernstein is chief scientist at Eastgate Systems, Inc. A graduate of Swarthmore College, he received his Ph.D. (in physical chemistry) from Harvard University. After helping to organize Eastgate in 1982, he joined the research staff at the Artificial Intelligence group at E. I. duPont de Nemours & Co., where here remained until returning to Eastgate in 1987. At Eastgate, he has overseen Eastgate's influential hypertext publishing program, which includes many of the most respected fiction and nonfiction hypertexts that have appeared to date. He has managed development of the Storyspace hypertext writing environment and designed Tinderbox, a content assistant for making, analyzing, and sharing notes. A part of nearly every ACM Hypertext Conference program committee since 1989, he has twice been its program co-chair, and was its keynote speaker in 1999. He is currently program chair of WikiSym '08, the 4th ACM Symposium on Wikis. His book, The Tinderbox Way, was published by Eastgate in 2006.
Using real data to invigorate student learning
Authors: Jukic Nenad , Gray Paul
Published: June 2008

Students need hands-on-experience with industrial strength databases and large data sets so they can deal with them when once employed. Many schools find it too expensive because of the cost and faculty resources required. That excuse is no longer valid. Colleges and Universities throughout the world can avail themselves of an extraordinary gift from Teradata Corporation that allows introducing large, complex problems into computer science classes without cost. The gift includes software and enormous databases available through the Internet as Software as a Service. This editorial describes the Teradata University Network, and how faculty can obtain this resource for their classes.
Global collaboration in course delivery
Authors: Clear Tony
Published: June 2008

Some recent experiences with Global Educational Collaborations have given me occasion to reflect on how sustainable such initiatives are, and whether they will over time become embedded in the fabric of modern University education, especially for courses such as Global Software Engineering. Swigger and colleagues argue to the contrary at least for now, observing that "technical barriers such as unreliable software and institutional regulations discourage most teachers from exploring distributed learning" [1]. But does this pessimistic view truly recognize the realities of the age? For Giddens "one of the dominant characteristics of modernity is the separation of time from space made possible by the standardization of time across the world", with "human efforts to standardize temporal frameworks inscribed in official time zones" [2]. Is a
Global Collaboration
then, inherently a product of the trend towards universal time, wherein time is the scarce resource of 'clock' time (based on what might be termed a
temponomic
world view [3, P.61].
Role of information systems as a business discipline
Authors: Topi Heikki
Published: June 2008

One of the questions that is frequently raised during any serious discussion related to the identity of Information Systems (IS) education is the relationship between the business domain and IS and the role of IS as a business discipline. Naturally, IS as an academic discipline has its strongest roots within the business school community and a history that is closely linked to the rapid growth in the dependence of businesses of all types and sizes on information technology. Particularly in North America, most of the founding academics in the field of IS came from business schools, and information systems as artifacts were seen to exist to support management in organizations. Both in research and in curriculum development, large corporations got more attention than smaller companies because they presented the most interesting and challenging problems to solve and had the most focused demand for graduates. In addition, business schools identified the need to hire academic specialists who are able to integrate issues related to business and technology in their research and teaching. Particularly during the boom years of late 1980s and 1990s, student demand for courses in Information Systems was very high, which obviously raised the level of interest in the discipline among business school administrators. The events of early 2000s led to the rapid declines in enrollments that we all have experienced and are fighting against. Not surprisingly, these developments have made some business schools question the value of IS programs and departments, but the field is still predominantly associated with business schools.
The originality glut
Authors: Lister Raymond
Published: June 2008

Originality is over-rated in computing education research. We have a world-wide glut of originality.
Some IFIP happenings
Authors: Turner A. Joe
Published: June 2008

As described in previous columns, the International Federation for Information Processing (IFIP) is a federation of IT societies. ACM is a member of IFIP, and SIGCSE sponsors ACM's representative to the IFIP Technical Committee on Education (TC3). This column provides a summary of some recent and upcoming IFIP activities.
Drink the coffee and see the puffy white clouds
Authors: Kaczmarczyk Lisa
Published: June 2008

Sometimes, in pursuit of your well percolated vision, you have to break with convention and take a really big risk. In my last column I wrote about taking a risk in the CS classroom, scary events that followed, and the ultimate pedagogical payoff that made it all worth it. This month I introduce you to my latest, and to date largest, plunge off the deep end.
Abstraction, model checking and software correctness
Authors: Henderson Peter B.
Published: June 2008

I hope you were able to read the contribution from Maria and Gary Litvin,
Pre-college Math Concepts vs Skills - Preparation for Computing Studies
, in my last column. This article addressed one of the most important issues our discipline faces, the preparation and motivation of young people to pursue a career in computing. To repeat, here is a quote from the back cover of their book for high school students
Mathematics for the Digital Age and Programming in Python: "The vision behind this book is that math and computer science should help each other. A programmer needs to be comfortable with abstractions, and that is precisely what math teaches. Computer science reciprocates by providing models and hands-on exercises that help clarify and illustrate more abstract math."
This columns contribution "Reflections on Teaching Abstraction and Other Soft Ideas" by Orit Hazzan, which can be found on page?? of this issue of Inroads, further reinforces the relevance of abstraction for software developers.
Separating between foes
Authors: Ginat David
Published: June 2008

The current issue's new challenge is slightly different from previous challenges. It involves two questions, of whether particular goals may be achieved. If they may be achieved, then a suitable algorithm should be developed and justified; otherwise -a proof of impossibility should be displayed. The solutions for both questions involve relevant and useful notions in computer science.
Supercomputing in plain english
Authors: Neeman Henry , Severini Horst , Wu Dee
Published: June 2008

The field of Cyberinfrastructure (CI) has experienced rapid and exciting progress in enabling technologies, but much slower improvements in application codes, largely because of the ongoing disconnect between the CI and application research communities. At the University of Oklahoma, the OU Supercomputing Center for Education & Research (OSCER) is addressing this issue using a multipronged pedagogical strategy that combines workshops, tours, question-and-answer and "rounds" (one-on-one interactions), with minimal jargon, using storytelling and analogies to capture the essential properties of Cyberinfrastructure.
Sudoku
Authors: Schreiner Axel T. , Heliotis James E.
Published: June 2008

Paying only lip service to the principles of object-oriented programming rarely results in the expected benefits. This paper presents a series of designs for a Sudoku application that will lead introductory students through the all-important process of trial and error. They will see examples of design analysis, criticism, and improvement. The paper concludes with some general pointers why and how the initial mistakes could have been avoided.
Perverse and foolish oft I strayed
Authors: Rolfe Timothy J.
Published: June 2008

This uses a massively wrong-headed algorithm for sorting to exemplify the use of the backtracking strategy and the branch-and-bound strategy. In addition, brief notes are included on parallel processing approaches: Java theads on multi-core computers and distributed processing through such message passing systems as PVM and MPI.
A denotational tracing domain for C++ programs
Authors: Goluboff Barry
Published: June 2008

By adding certain denotational constructs to C++, a domain is created wherein programs are traced as an augmentation of their source code. This tracing method is intended to be used along with other instructional strategies for teaching C++ programming.
Leveraging students' programming laboratory work as worked examples
Authors: Lui Andrew K. , Cheung Yannie H. Y. , Li Siu Cheung
Published: June 2008

This paper describes a web-based courseware that is designed to further improve the programming skills of strong students. The courseware leverages students' laboratory work as worked examples. Worked examples are regarded as an efficient tool for schema acquisition. The variations in the methods used in the examples provide an opportunity to acquire alternative schemas for solving problems. The paper describes the functions of the courseware. The results of the evaluations suggest that students' solutions are intrinsically useful as worked examples because they exhibit significant variations.
Reviewing the SIGCSE reviewing process
Authors: Kumar Amruth , Joseph Patricia A. , Goldweber Michael , Wagner Paul J.
Published: June 2008

The ACM Special Interest Group in Computer Science Education (SIGCSE) has long used a double-blind reviewing process for both its annual symposium and ITiCSE conference. However, it is healthy for a community to review its policies and practices periodically to ensure that they continue to meet the needs and objectives of the community. Toward this end, this paper suggests a set of general goals for the SIGCSE reviewing process, identifies a number of important issues, and presents suggestions for resolving these issues.
Teaching the business of software development
Authors: Vandever Kelly
Published: June 2008

Computer science graduates come into the software development workforce with some great knowledge. But additional education is required to better prepare them for the business of software development. In this article, Kelly Vandever of Communications for Everyone, LLC encourages educators to consider what other elements should be included as part of their college programs.
Kids in Computing (K.I.C.)
Authors: Rafieymehr Ali
Published: June 2008

We, as educators, have all seen firsthand that computer science enrollment numbers have gone down during the past few years. Is there a solution that we can employ that will solve the enrollment problem? Although there is no single solution to solve the problem, this paper will present a combination of various ways that could be used to tackle the enrollment problem and hopefully help improve enrollment numbers.
Improving the computer science in bioinformatics through open source pedagogy
Authors: Dionisio John David N. , Dahlquist Kam D.
Published: June 2008

Bioinformatics relies more than ever on information technologies. This pressures scientists to keep up with software development best practices. However, traditional computer science curricula do not necessarily expose students to collaborative and long-lived software development. Using open source principles, practices, and tools forms an effective pedagogy for software development best practices. This paper reports on a bioinformatics teaching framework implemented through courses introducing computer science students to the field. The courses led to an initial product release consisting of software and an
Escherichia coli
K12 GenMAPP Gene Database, within a total "incubation time" of six months. (1)
An industry perspective on the beginnings of CAD
Authors: Sanders Norman
Published: June 2008

This paper is a discussion of the early days of CAM-CAD at The Boeing Company, covering the period approximately 1956 to 1965. This period saw probably the first successful industrial application of ideas that were gaining ground during the very early days of the computing era. Although the primary goal of the CAD activity was to find better ways of building the 727 airplane, this activity led quickly to the more general area of computer graphics, leading eventually to today's picture-dominated use of computers. The paper started as an internal exchange of memories between some of the people primarily concerned, but is now offered as the possible start of a discussion involving other such initiatives during that period.
Eliminating phosphorylation sites of the parathyroid hormone receptor type 1 differentially affects stimulation of phospholipase C and receptor internalization
Authors: Miedlich Susanne U. , Abou-Samra Abdul B.
Published: June 2008

The parathyroid hormone (PTH)/PTH-related peptide (PTHrP) receptor (PTH1R) belongs to family B of seven-transmembrane-spanning receptors and is activated by PTH and PTHrP. Upon PTH stimulation, the rat PTH1R becomes phosphorylated at seven serine residues. Elimination of all PTH1R phosphorylation sites results in prolonged cAMP accumulation and impaired internalization in stably transfected LLC-PK1 cells. The present study explores the role of individual PTH1R phosphorylation sites in PTH1R signaling through phospholipase C, agonist-dependent receptor internalization, and regulation by G protein-coupled receptor kinases. By means of transiently transfected COS-7 cells, we demonstrate that the phosphorylation-deficient (pd) PTH1R confers dramatically enhanced coupling to Gq/11proteins upon PTH stimulation predominantly caused by elimination of Ser491/492/493, Ser501, or Ser504. Reportedly, impaired internalization of the pd PTH1R, however, is not dependent on a specific phosphorylation site. In addition, we show that G protein-coupled receptor kinase 2 interferes with pd PTH1R signaling to Gq/11proteins at least partially by direct binding to Gq/11proteins.