Miracle-dz/UniFAR-FTUs huggingface dataset:
Detecting and understanding students' misconceptions related to algorithms and data structures

We describe the first results of our work towards a concept inventory for Algorithms and Data Structures. Based on expert interviews and the analysis of 400 exams we were able to identify several core topics which are prone to error. In a pilot study, we verified misconceptions known from the literature and identified previously unknown misconceptions related to Algorithms and Data Structures. In addition to this, we report on methodological issues and point out the importance of a two-pronged approach to data collection.
The Human–Artifact Model: An Activity Theoretical Approach to Artifact Ecologies

Although devices of all shapes and sizes currently dominate the technological landscape, human–computer interaction (HCI) as a field is not yet theoretically equipped to match this reality. In this article we develop the human–artifact model, which has its roots in activity theoretical HCI. By reinterpreting the activity theoretical foundation, we present a framework that helps addressing the analysis of individual interactive artifacts while embracing that they are part of a larger ecology of artifacts. We show how the human–artifact model helps structuring the understanding of an artifact's action-possibilities in relation to the artifact ecology surrounding it. Essential to the model is that it provides four interconnected levels of analysis and addresses the possibilities and problems at these four levels. Artifacts and their use are constantly developing, and we address development in, and of, use. The framework needs to support such development through concepts and methods. This leads to a methodological approach that focuses on new artifacts to supplement and substitute existing artifacts. Through a design case, we develop the methodological approach and illustrate how the human–artifact model can be applied to analyze present artifacts and to design future ones. The model is used to structure such analysis and to reason about findings while providing leverage from activity theoretical insights on mediation, dialectics, and levels of activity.
USING CONCEPT RELATIONSHIPS TO IMPROVE DOCUMENT CATEGORIZATION

In the information age we much depend on our ability to find information hidden in mostly unstructured and textual documents. This article proposes a simple method in which (as an addition to existing systems) categorization accuracy can be improved, compared to traditional techniques, without requiring any time-consuming or language-dependent computation. That result is achieved by exploiting properties observed in the entire document collection as opposed to individual documents, which may also be regarded as a construction of an approximate concept network (measuring semanticdistances). Thesepropertiesaresufficientlysimpletoavoidentailingmassivecomputations; however, they try to capture the most fundamental relationships between words or concepts. Experiments performed on the Reuters-21578 news article collections were evaluated using a set of simple measurements estimating clustering efficiency, and in addition by Cluto, a widely used document clustering software. Results show a 5–10% improvement in clustering quality over traditional tf (term frequency) or tf× idf (term frequency-inverse document frequency) based clustering.
BIOMETRIC TECHNOLOGIES FOR ONLINE STUDENT AUTHENTICATION

In this work we present: i) an analysis of biometric technologies for online student authentication; ii) a case study on keystroke dynamics authentication applied to a real operational environment. Concisely, this work studies the biometric technologies and their advantages/disadvantages for online student authentication services. The analysis is made on the basis of three main pillars: performance, usability and legal concerns. Our study provides new insights on the deployment of these technologies in educational environments with special attention to keystroke dynamics systems. Keystroke dynamic authentication has attracted much interest from industry and researchers during the last decade. Keystroke dynamics authentication is interesting for online authentication because it is: i) transparent (it runs in the background without requiring explicit user interaction); ii) continuous (authentication can be performed over all the user activity, not only based on an initial access to the platform). This work includes a case study on keystroke dynamic authentication over the typing patterns of 64 students answering questions in 3 online exams over a semester. We analyze the performance of four keystroke biometric systems and the results obtained show a promising performance with a correct student authentication over 90%. This work encourages to further explore in authentication services based on biometric technologies for online courses.
Public Education: Reply

To understand the significance of the price and wealth elasticities estimated in my 1975 article and reestimated for a variety of samples by George Perkins, it is useful to recall the legal controversy that surrounded education finance in the early 1970's. In the historic and much publicized case of Serrano vs. Priest (1971), the California Supreme Court held that California's system of educational finance violated California's state constitution because local educational outlays were related to local property values. Similar cases were being introduced in the courts of other states and in the U.S. Supreme Court. Perhaps the most commonly discussed legal remedy in cases like Serrano was a plan referred to as "district power equalization" (DPE) by its original advocates, J. E. Coons, W. H. Clune, and S. D. Sugarman in their very influential book (1970). District power equalization is a matching grant formula that makes each percentage point of tax rate levied on the market value of local property produce the same revenue, independent of the actual local tax base. To be more precise, let W, be the tax base ("wealth") per pupil in school district i and 6i be the tax rate chosen by school district i. The per pupil tax raised locally would therefore be Ti =61iWi. District power equalization would make the total per pupil revenue of district i proportional to 6i but independent of W, or Ri = 6iW*, where W* is the equivalent tax base implicitly assigned to all school districts by the DPE matching rate formula. The matching rate for district i (min) is the number of state level dollars given to district i for every dollar of revenue that they raise locally; therefore 1 + mi = R/Ti = W*/Wi. The DPE formula is important because it implies that the local "price" of educational outlays is proportional to wealth. If district i's price of buying educational outlays is defined as the amount that the district must produce in local tax revenue per dollar of total spending, the DPE formula implies pi = TIRi = WJ/W*. In terms of the pricewealth elasticity of my earlier paper and Perkins' comment, district power equalization implies v =-1. My reason for estimating price and wealth elasticities of demand for local school districts was to answer the following two questions. First, if the courts required the state governments to finance education in a way that eliminated the currently observed association between local wealth and educational outlays, what would be the appropriate matching formula? Second, if the courts mandated the district power equalizing rule, what would be the resulting association between wealth and educational outlays? To make these ideas more precise, I decided to measure the association by the elasticity of per pupil education outlays with respect to per pupil wealth and called this elasticity the degree of wealth neutrality. By applying Theil's famous formula for specification bias, I showed that the wealth neutrality (a) can be written
Case Studies on Cache Performance and Optimization of Programs with Unit Strides

Cache performance in modern computers is important for program efficiency. A cache is thrashing if a significant amount of time is spent moving data between the memory and the cache. This paper presents two cache thrashing examples, one in scientific computing and one in image processing, both of which involve several one‐dimensional arrays that are accessed sequentially, i.e., with unit strides. Accessing arrays in unit strides was considered very efficient on cache‐based computer systems. However, the existence of cache thrashing is demonstrated by significant increases in computing speed in the equivalent programs tuned for cache locality. This shows that accessing several arrays sequentially may cause cache thrashing. Thus, to improve cache performance, it is important that the compiler or the programmer takes all arrays inside a loop into consideration. © 1997 by John Wiley & Sons, Ltd.
Design of a flexible high-speed FPGA-based flow monitor for next generation networks

The evolution of new services and the development of next generation networks is placing severe demands on networks. In order to support emerging services, it is clear that a higher degree of monitoring functionality is needed within networks. One approach is to use the programmability and performance of Field Programmable Gate Array (FPGA) technology to allow distributed monitoring but this present challenges around memory usage and highlights the need for a strategically different approach to how flows are monitored. A novel FPGA-based, programmable IP flow monitor is presented, that permits various forms of network monitoring functionality, specifically monitoring of different classes of traffic, to be performed. A key aspect was to address the traditionally long design times, through the use of a new, experimental, high-level design flow called Packet Xpress which allowed functions to be quickly implemented, providing a twentyfold speed-up in design time. The monitor has been implemented on a Xilinx Virtex-5 based ML506 board and verified in hardware using real Internet traffic traces. The platform allowed us to experiment with various monitoring functions and establish their resource requirements.
Constructing the eEconomy Bled , Slovenia , June 17-19 , 2002 Promises and Pitfalls of SME Integration

The advent of Web technology and standards as XML had many hope for seamless business integration. Especially small and medium sized enterprises (SMEs) were considered to finally participate in existing EDI networks. But there are drawbacks to SME integration. In this paper we show that there are principle obstacles to integrating SMEs that are often neglected. If SMEs do not employ automated material management systems, there is obviously most likely no possible benefit from processes automation. Also, the SMEs’ relative position within a value chain can pose typical problems. Addressing some of the identified problems, a solution called ASP-EDI is proposed, the concept of which has recently been proven when it was implemented as part of the new Internet strategy within the German office supply industry (95% SMEs). The co-developed WebEDI converter descript in section 5.1 (ASP-EDI) has won the third price of the German “IT inside SME 2010” award. Roman Beck, Tim Weitzel, Wolfgang König 568 1. SME Integration: The Problem Has Been Here Before
Studying PH. A. N. T. O. M. in the wild: a pervasive persuasive game for daily physical activity

A pervasive persuasive game, PH. A. N. T. O. M. , has been designed and developed to increase the daily exercise level of the players. The idea is to embed the physical activity into a fun and engaging mobile game experience. This is combined with a storyline and virtual game setting integrated into the everyday life of the players to add a sense of purpose for them to get outside and be active. This paper reports from a field study with nine participants which was conducted to evaluate the user experience of the game in the wild and investigate the persuasive nature of it.
Effective lagrangian for 3d Script N = 4 SYM theories for any gauge group and monopole moduli spaces

We construct low energy effective lagrangians for 3d = 4 supersymmetric Yang-Mills theory with any gauge group. They represent supersymmetric ? models at hyper-K? hler manifolds of dimension 4r (r is the rang of the group). In the asymptotic region, perturbatively exact explicit expression for the metric are written. We establish the relationship of this metric with the TAUB-NUT metric describing the perturbatively exact effective lagrangians for unitary groups and monopole moduli spaces: the former is obtained out of the latter by a proper hyper-K? hler reduction. We describe in details the reduction procedure for SO / Sp / G2 gauge groups, where it can also be given a natural interpretation in D-brane language. We conjecture that the exact nonperturbative metrics can be obtained by a similar hyper-K? hler reduction from the corresponding multidimensional Atiyah-Hitchin metrics.
Group Orbit Optimization: A Unified Approach to Data Normalization

In this paper we propose and study an optimization problem over a matrix group orbit that we call \emph{Group Orbit Optimization} (GOO). We prove that GOO can be used to induce matrix decomposition techniques such as singular value decomposition (SVD), LU decomposition, QR decomposition, Schur decomposition and Cholesky decomposition, etc. This gives rise to a unified framework for matrix decomposition and allows us to bridge these matrix decomposition methods. Moreover, we generalize GOO for tensor decomposition. As a concrete application of GOO, we devise a new data decomposition method over a special linear group to normalize point cloud data. Experiment results show that our normalization method is able to obtain recovery well from distortions like shearing, rotation and squeezing.
Short adjacent repeat identification based on Chemical Reaction Optimization

The analysis of short tandem repeats (STRs) in DNA sequences has become an attractive method for determining the genetic profile of an individual. Here we focus on a more general and practical issue named short adjacent repeats identification problem (SARIP), which is extended from STR by allowing short gaps between neighboring units. Presently, the best available solution to SARIP is BASARD, which uses Markov chain Monte Carlo algorithms to determine the posterior estimate. However, the computational complexity and the tendency to get stuck in a local mode lower the efficiency of BASARD and impede its wide application. In this paper, we prove that SARIP is NP-hard, and we also solve it with Chemical Reaction Optimization (CRO), a recently developed metaheuristic approach. CRO mimics the interactions of molecules in a chemical reaction and it can explore the solution space efficiently to find the optimal or near optimal solution(s). We test the CRO algorithm with both synthetic and real data, and compare its performance in mode searching with BASARD. Simulation results show that CRO enjoys dozens of times, or even a hundred times shorter computational time compared with BASARD. It is also demonstrated that CRO can obtain the global optima most of the time. Moreover, CRO is more stable in different runs, which is of great importance in practical use. Thus, CRO is by far the best method on SARIP.
Factor productivity and efficiency of the Vietnamese economy in transition

The purpose of this paper is to estimate changes in productivity, technical efficiency and technology across the economic sectors during the period 1985-2006. We also seek to identify the turning points for productivity growth to see whether it was accompanied by technological change and/or technical efficiency. For estimating economic growth, aggregate production function is used. We find that, during the study period, technical progress contributed about 19.7 per cent to the country’s economic growth. We also estimate total factor productivity for the whole economy as well as for individual economic sectors, and the results show that the economy’s productivity growth was largely driven by the industrial sector.
Research on Supply Chain Inventory Planning with Time-Space Network Under E-Commerce Environment

The problem of multi-period inventory planning in the three layers supply chain composed of multi-manufacturers, multi-retailers and multi-consumers under e-Commerce environment is studied, in which the demand is equal with the supply. The interactive relation of the order time and the transportation space is taken into account. The time-space network is introduced to describe this problem, by which the mathematical model for inventory planning that make the supply chain get the smallest cost is established. Finally, a numerical example is analyzed to prove the rationality of this model, which confirms that the model can provide the best supply chain inventory planning under e-commerce environment.
Evolutionary models for low-mass stars and brown dwarfs: uncertainties and limits at very young ages

We analyse pre-Main Sequence evolutionary tracks for low mass stars with masses $m \\le 1.4 \\msol$ based on the Baraffe et al. (1998) input physics. We also extend the recent Chabrier et al. (2000) evolutionary models based on dusty atmosphere to young brown dwarfs down to one mass of Jupiter. We analyse current theoretical uncertainties due to molecular line lists, convection and initial conditions. Simple tests on initial conditions show the high uncertainties of models at ages $\\simle$ 1 Myr. We find a significant sensitivity of atmosphere profiles to the treatment of convection at low gravity and $\\te < 4000$ K, whereas it vanishes as gravity increases. This effect adds another source of uncertainty on evolutionary tracks at very early phases. We show that at low surface gravity ($\\log g \\simle 3.5$,) the common picture of vertical Hayashi lines with constant $\\te$ is oversimplified. The effect of a variation of initial deuterium abundance is studied. We compare our models with evolutionary tracks available in the literature and discuss the main differences. We finally analyse to which extent current observations of young systems provide a good test for pre-Main Sequence tracks.
GA Based Congestion Aware Algorithm for Application in NoC

Efficient application assignment algorithm is important for high performance and low power consumption in NoC architecture. In this paper, we apply novel algorithm based on GA (Genetic Algorithm) and maximal free matrix constraint, which aim at using confliction avoidance and minimization between router communications in order to provide less network contentions during several running applications and get global optimization in a given NoC platform (16x16 cores). After applying our GA based congestion-aware placement algorithm, we observe dramatic reduction of congestion and improvement of performance compared to random selection results. A GA based algorithm for the purpose of congestion avoidance and minimization handles the inter-processor communication. When the several applications run in NoC architecture, these tasks need to be allocated to the appropriate resources of the given NoC configuration. The GA based algorithm makes a run-time decision by executing our proposed algorithm in order to ensure reduced communication energy savings. Recent work shows that task migration mechanisms with check points can also provide energy savings. Our algorithm for application mapping approach can be also used in conjunction with task migration to provide high performance and further energy savings.
Low Cholesterol is Associated With Mortality From Stroke, Heart Disease, and Cancer: The Jichi Medical School Cohort Study

Background We investigated the relationship between low cholesterol and mortality and examined whether that relationship differs with respect to cause of death. Methods A community-based prospective cohort study was conducted in 12 rural areas in Japan. The study subjects were 12 334 healthy adults aged 40 to 69 years who underwent a mass screening examination. Serum total cholesterol was measured by an enzymatic method. The outcome was total mortality, by sex and cause of death. Information regarding cause of death was obtained from death certificates, and the average follow-up period was 11.9 years. Results As compared with a moderate cholesterol level (4.14–5.17 mmol/L), the age-adjusted hazard ratio (HR) of low cholesterol (<4.14 mmol/L) for mortality was 1.49 (95% confidence interval [CI]: 1.23–1.79) in men and 1.50 (1.10–2.04) in women. High cholesterol (≥6.21 mmol/L) was not a risk factor. This association was unchanged in analyses that excluded deaths due to liver disease, which yielded age-adjusted HRs of 1.38 (95% CI, 1.13–1.67) in men and 1.49 (1.09–2.04) in women. The multivariate-adjusted HRs and 95% CIs of the lowest cholesterol group for hemorrhagic stroke, heart failure (excluding myocardial infarction), and cancer mortality significantly higher than those of the moderate cholesterol group, for each cause of death. Conclusions Low cholesterol was related to high mortality even after excluding deaths due to liver disease from the analysis. High cholesterol was not a risk factor for mortality.
Complete Multimedia Database Solution

This paper describes MoonBase, a multimedia database system being developed for new emerging multimedia applications. MoonBase provides a complete system solution to manage diverse multimedia technologies and integrate multimedia islands-of-information. MoonBase is an extensible federated relational database coordinator that non-intrusively adds multimedia capabilities to existing relational database management systems for mission-critical environments. MoonBase uses a parallel multimedia object server called Prospector, to store and manipulate multimedia objects. Prospector is a multi-purpose object server that internally builds upon Bell Labs’ EOS transactional object manager. Prospector executes User Defined Functions (UDFs) in a parallel environment which allows high performance content-analysis and complex operations to be performed on large databases of (multimedia) objects. In this paper, we describe the global architectures of Moonbase and Prospector; the SQL3 Abstract Data Type (ADT) and UDF development and execution facilities; and key differentiators of Moonbase in the current multimedia market. We will highlight areas that are key to making Moonbase a successful multimedia solution: multimedia networking issues; infrastructure and a virtual networking strategy to manage heterogeneous networks; client user interface design and new multimedia use semantics; and video object servers.