Miracle-dz/UniFAR-FTUs huggingface dataset:
Bidirectional type class instances

GADTs were introduced in Haskell’s eco-system more than a decade ago, but their interaction with several mainstream features such as type classes and functional dependencies has a lot of room for improvement. More specifically, for some GADTs it can be surprisingly difficult to provide an instance for even the simplest of type classes. In this paper we identify the source of this shortcoming and address it by introducing a conservative extension to Haskell’s type classes: Bidirectional Type Class Instances. In essence, under our interpretation class instances correspond to logical bi-implications, in contrast to their traditional unidirectional interpretation. We present a fully-fledged design of bidirectional instances, covering the specification of typing and elaboration into System FC, as well as an algorithm for type inference and elaboration. We provide a proof-of-concept implementation of our algorithm, and revisit the meta-theory of type classes in the presence of our extension.
Cinematic scientific visualization: the art of communicating science

The Advanced Visualization Lab (AVL) is part of the the National Center for Supercomputing Applications (NCSA) at the University of Illinois at Urbana-Champaign. The AVL is led by Professor Donna Cox, who coined the term "Renaissance Team", with the belief that bringing together specialists of diverse backgrounds creates a team that is greater than the sum of its parts, and members of the AVL team reflect that in our interdisciplinarity. We specialize in creating high-quality cinematic scientific visualizations of supercomputer simulations for public outreach.
Stage Delay Scheduling: Speeding up DAG-style Data Analytics Jobs with Resource Interleaving

To increase the resource utilization of datacenters, big data analytics jobs are commonly running stages in parallel which are organized into and scheduled according to the Directed Acyclic Graph (DAG). Through an in-depth analysis of the latest Alibaba cluster trace and our motivation experiments on Amazon EC2, however, we show that the CPU and network resources are still under-utilized due to the unwise stage scheduling, thereby prolonging the completion time of a DAG-style job (e.g., Spark). While existing works on reducing the job completion time focus on either task scheduling or job scheduling, stage scheduling has received comparably little attention. In this paper, we design and implement DelayStage, a simple yet effective stage delay scheduling strategy to interleave the cluster resources across the parallel stages, so as to increase the cluster resource utilization and speed up the job performance. With the aim of minimizing the makespan of parallel stages, DelayStage judiciously arranges the execution of stages in a pipelined manner to maximize the performance benefits of resource interleaving. Extensive prototype experiments on 30 Amazon EC2 instances and complementary trace-driven simulations show that DelayStage can improve the cluster resource utilization by up to 81.8% and reduce the job completion time by up to 41.3%, in comparison to the stock Spark and the state-of-the-art stage scheduling strategies, yet with acceptable runtime overhead.
Are we done with ray tracing?

Real-time graphics has come a long way since the "brute-force approach" of rasterization had been classified "ridiculously expensive" in 1974. Henceforth the promise "Ray tracing is the future and ever will be" drove the development of ray tracing algorithms and hardware, and resulted in a major revolution of image synthesis. This course will take a look at how far out the future is, review the state of the art, and identify the current challenges for research. Not surprisingly, it looks like we are not done with ray tracing, yet.
A characterization of cooperation in dynamic network games

This paper explores conditions under which players cooperate in a dynamic network game. Historically, folk theorems have provided a speckled perspective by showing that there exists equilibria where players cooperate, do not cooperate, as well as a myriad of equilibria between these extremes. Our main contribution is identifying a necessary and sufficient equilibrium refinement such that, for all equilibria, all players cooperate in order to reach a strictly Pareto dominant graph. We base our results on a class of games that subsume forward-looking extensions of exchange economies with indivisible goods.
FlowCon: Elastic Flow Configuration for Containerized Deep Learning Applications

An increasing number of companies are using data analytics to improve their products, services, and business processes. However, learning knowledge effectively from massive data sets always involves nontrivial computational resources. Most businesses thus choose to migrate their hardware needs to a remote cluster computing service (e.g., AWS) or to an in-house cluster facility which is often run at its resource capacity. In such scenarios, where jobs compete for available resources utilizing resources effectively to achieve high-performance data analytics becomes desirable. Although cluster resource management is a fruitful research area having made many advances (e.g., YARN, Kubernetes), few projects have investigated how further optimizations can be made specifically for training multiple machine learning (ML) / deep learning (DL) models. In this work, we introduce FlowCon, a system which is able to monitor loss functions of ML/DL jobs at runtime, and thus to make decisions on resource configuration elastically. We present a detailed design and implementation of FlowCon, and conduct intensive experiments over various DL models. Our experimental results show that FlowCon can strongly improve DL job completion time and resource utilization efficiency, compared to existing approaches. Specifically, FlowCon can reduce the completion time by up to 42.06% for a specific job without sacrificing the overall makespan, in the presence of various DL job workloads.
Tessellating Star Stencils

Stencil computations represent a very common class of nested loops in scientific and engineering applications. The exhaustively studied tiling is one of the most powerful transformation techniques to explore the data locality and parallelism. Existing work often uniformly handles different stencil shapes. This paper first presents a concept called natural block to identify the difference between the star and box stencils. Then we propose anew two-level tessellation scheme for star stencils, where the natural block, as well as its successors can tessellate the spatial space and their extensions along the time dimension are able to form a tessellation of the iteration space. Furthermore, a novel implementation technique called double updating is developed for star stencils specifically to improve the in-core data reuse pattern. Evaluation results are provided that demonstrate the effectiveness of the approach.
On Integration of Appends and Merges in Log-Structured Merge Trees

As widely used indices in key-value stores, the Log-Structured Merge-tree (LSM-tree) and its variants suffer from severe write amplification due to frequent merges in compactions for write-intensive applications. To address the problem, we first propose the Log-Structured Append-tree (LSA-tree), which tries to compact data with appends instead of merges, significantly reduces the write amplification and solves the issues existed in current append trees. However LSA increases read and space amplifications. Furthermore based on LSA, we design the Integrated Append/Merge-tree (IAM-tree). IAM selects appends or merges in compaction operations according to the size of memory-cached data. Theoretical analysis shows that IAM reduces the write amplification of LSM while keep the same read and space amplification. We implement IAM as a user library named IamDB. Experiments show that its write amplification is much less than that of LSM, only 8.71 vs. 19.00 for 1TB data with 64GB memory. Compared with nicely tuned LevelDB and RocksDB, IamDB provides 1.4-2.7× and 1.6-1.9× better write throughput, saves 12% and 10% disk space respectively, as well as the comparable read and scan performance. At the meantime IamDB achieves the most stable tail latency.
ICT and the New Zealand secondary school curriculum

Val Savidan Information and Communication Technology (ICT) does not have a strong presence in New Zealand secondary school settings. This paper examines the introduction of the new curriculum and ICT up to its development at the millenium. The current status of ICT in secondary schools is then outlined, and barriers and issues related to innovation adoption are discussed. Links are made with postmodern theory. A rationale for why schools should strive for integration of ICT is provided, and there are suggestions for how schools could achieve this.
Effect of Micro Polypropylene Fibre on the Performance of Fly Ash-Based Geopolymer Concrete

Abstract Geopolymer offers significant promise to the construction world as a possible alternative to ordinary Portland cement (OPC). Like conventional Portland cement concrete, the matrix brittleness in geopolymer composites can be reduced by introducing suitable fibre reinforcement. A few investigations on fibre reinforced geopolymer composites are available. However there is still a gap to comprehend and enhance their performance. This paper describes the effect of incorporating micro polypropylene fibres on the strength and durability characteristics of geopolymer concrete. The engineering and durability properties like workability, compressive strength, split tensile strength, flexural strength, modulus of elasticity, and sorptivity of geopolymer concrete reinforced with micro polypropylene fibres is presented. The effect of the sulfuric acid attack on Geopolymer Concrete reinforced with micro polypropylene fibres is also discussed. The results show that hydrophobic characteristics of the micro polypropylene fibre led to weak contact with the geopolymer binder and hence weakened the mechanical performance of the fly ash based geopolymer matrix. However significant improvements in durability properties were noted.
Virtualization Solutions Supporting Privacy and Data Protection in Online Activities

Abstract Nowadays, smart devices like computers, tablets, and smartphones allow transmitting the information everywhere, with high speed, over the World Wide Web. However, risks regarding data integrity, privacy and security when using the Internet, increased dramatically, as methods designed to exploit the system’s vulnerabilities are more and more sophisticated. Therefore the need for people working in professional environments to protect their private data when using unsecure connections, by employing advanced tools. There are multiple solutions, but we will focus on the use of virtualization software like VMware or Oracle Virtual Box, together with traditional privacy measures (use of proxies and VPN’s). Today’s smart devices store an important amount of data about their owners and, in most of the cases, people don’t even realize this. Installing and using protection means is often not enough. They have to be properly setup in order to ensure the desired level of security, or anonymity, when using the Internet, and require for the military personnel a good knowledge not only about cyber vulnerabilities and risks, but also technical capabilities and features of the employed security solutions. DISCLAIMER: This paper expresses the views, interpretations, and independent position of the authors. It should not be regarded as an official document, nor expressing formal opinions or policies, of NATO or the HUMINT Centre of Excellence (HCOE).
Reproduction of silver fir (Abies alba Mill) forests in the Ukrainian Carpathians

Abstract Existing knowledge of the Ukrainian foresters related to the historical changes and current state of silver fir forests, as well as on the various methods of restoration of such forests in the Ukrainian Carpathians were discussed. Forest cover of fir stands in this region has been diminishing in the last two centuries. Only in the period from 1947 to 1956, the area of fir stands in Ukrainian Carpathians decreased by 38.8%. Currently, the restoration of fir stands in these areas are crucial for Ukrainian forestry. Therefore, the natural as well as artificial regeneration using seeds obtained from seed orchards are currently used. Thus, improving the forest stands’ conditions mostly composed of single-spruce plantations need to be improved through changing the species compositions. However, the restoration of fir stands is time and labour-intensive, and require a long-term strategy.
A 82.5% Power Efficiency at 1.2 mW Buck Converter with Sleep Control

This paper presents a DC-DC buck converter which uses a sleep control to improve the power efficiency in a few mW light load condition. The sleep control turns off analog controller building blocks to reduce the static power losses during the off-duty period of pulse width modulation. For verification, a buck converter has been implemented in a 0.18 mm CMOS process. The power efficiency has been improved from 76.7% to 82.5% with a 1.2 mW load. The maximum power efficiency is 95% with a 9 mW load.
Visual Analysis of Cylindrically Polarized Light Beams’ Focal Characteristics by Path Integral

Abstract To analyze the focal characteristics of cylindrically polarized beams, a visual analysis method is proposed. As known, the focal field can be described by three mutually perpendicular components, each one is the total contribution of all parts of the incident beams. For each component of all contributing parts weapply path integral method, then from the path integral curves extract focal field properties immediately, such as polarization state or intensity distribution. The analysis process of PI is visual and more understandable, and has more powerful information extraction function, which is also helpful for the design of special filtering pupil.
Evaluation of Impulsivity and Decision Making in Early and Late-Onset Alcohol Addiction

Objective: In this study we aimed to compare impulsivity and decision-making (DM) in early and late-onset alcohol addicts and investigate the relation between impulsivity and DM. Method: In our study, impulsivity and DM were evaluated respectively with Barratt Impulsivity Scale (BIS-11) and Iowa Gambling Test (IGT) in total 55 alcohol addicted male patients, 27 of them were early onset and 28 were late onset. Early and late onset groups were compared in terms of Obsessive Compulsive Drinking Scale (OCDS), alcohol amount that was consumed per day and the family history of alcoholism. Results: While only 33.3% of patients in early onset group were married, the patients in late onset group who were married were found to be 71.4%. There was a history of alcohol addiction respectively in the family of 66.6% of early onset group and of 39.3% of late onset group. In early onset group, attention and motor impulsivity were at more significant level than late onset group. In early onset group; OCDS score were at significant level more than late onset group. It was determined that there is no difference in terms of DM which was evaluated from the early stage to the last stage of IGT. Negative correlation was found between education period and attention impulsivity. Negative correlation was determined at significant level between age of regular alcohol usage, alcohol amount that was consumed per day, attention impulsivity and OCDS. Positive correlation was determined at significant level between alcohol amount which is used per day, attention, motor, non-planning impulsivity and OCDS. Increased amount of alcohol that was consumed per day and high OCDS score are effect attention impulsivity in regression analysis. Increased amount of alcohol that was consumed per day is effects motor impulsivity. Conclusion: While impulsivity in early-onset alcohol addicts is at more significant level than late-onset group, it was determined that there is no difference of DM between two groups.
Chemical Compounds from Thymus Vulgaris and their Antimicrobial Activity

Abstract This paper aims at highlighting the antibacterial activity of thyme (Thymus vulgaris) essential oils against the Staphylococcus aureus strain isolated from the nasal secretion of an anonymous patient, by employing the Kirby-Bauer method, and at establishing their chemical composition through GC MS methods. The oils were made from plants industrially grown in several geographic areas. The measurements taken showed that thyme oils contain thymol (between 32% and 41.5%), and that the antibacterial action of thyme depends both on the provenance of the culture from which the essential oil was extracted and on the concentration of thymol in the oil, as well as on the sensitivity of the isolated strain.
IT Reliability and Innovation in SMEs: Empirical Research

Abstract Purpose: Analysis of theoretical views and empirical research concerning the relation between IT reliability and the innovation level of organizations. Methodology: The pilot (sample: 100) and main (sample: 400) survey was conducted in 2017 among SMEs located in Poland. Findings: The empirical analysis shows that there is a relation between IT reliability and innovation level. Moreover, information reliability appears as a factor that may influence the organization’s ability to create innovations. Furthermore, service reliability proves to correlate with innovation level as well, which provides additional conclusions that support the realization that service is an important feature, which may also influence employees’ ability to employ IT appropriately and efficiently, thereby supporting the generation of innovation. Implications: Findings enable us to indicate the direction of further promising research that should concern the relationship between IT reliability and innovation in the context of stages of the innovation process and different types of innovation, which should be analyzed separately. Value: The article presents a new factor that may influence the possibility of creating various types of innovations. Usually, papers focus on IT systems, while the relationship between IT reliability and innovation allows us to look deeper into this relationship.
IREX III: Performance of Iris Identification Algorithms

Disclaimer Specific hardware and software products identified in this report were used in order to perform the evaluations described in this document. In no case does identification of any commercial product, trade name, or vendor, imply recommendation or endorsement by the National Institute of Standards and Technology, nor does it imply that the products and equipment identified are necessarily the best available for the purpose.
Assessment of the Financial Performance Transparency of Public Benefit Organisations

Abstract Research purpose. The aim of the research is to assess the transparency of financial performance of public benefit organisations (PBOs). Methodology. To achieve the aim and to accomplish the tasks set, general-scientific methods were used: the monographic method, the method of document analysis and the graphical method. A statistical analysis method – descriptive statistics – and a sociological research method – surveying – were used as well. Findings. Since 1 October 2014 when the Public Benefit Organisation Law came into force in Latvia, the number of PBOs has been increasing every year. On 1 January 2018, the number of organisations with valid PBO status had reached 2,775. To get an insight into the opinions of Latvian PBOs on the disclosure of financial information, a questionnaire was developed. The survey was attended by 201 respondents. The questionnaires revealed that 64.68 percent of the respondent organisations had a website or a web page on a social network, although only 21.89 percent of these respondents' websites contained some sort of financial information. In parallel with the PBO survey, a society survey was conducted to get an overview of the public opinions about the need to make PBO financial information freely available. The survey was attended by 116 respondents. The results indicated that although the PBO attitude to the disclosure of financial information was considered to be reserved, the public saw the need for such information. In view of the insufficient availability of financial information in the country and the low activity of PBOs themselves in voluntarily disclosing their financial information on their websites, it is necessary to carry out activities that supplement free-access information resources and/or motivate the organisations themselves to provide free access to such information. Practical implications. Based on the experience of other European countries, the Ministry of Finance has to consider amending the PBO Law to oblige PBOs to publish their annual financial and performance reports on their websites or in an equivalent way, thereby contributing to the transparency and accountability of the PBOs towards the society.
Student-Centered Learning for Interdisciplinary Courses: A Multifaceted Approach

Dr. Nigel Zheng received his B. Eng from Zhejiang University, China, M.Sc. from College of Medicine, Shanghai Jiaotong University, and M.Sc. and Ph.D. from Univesity of Saskatchewan, Canada. Currently he is an assistant professor in the Center for Biomedical Engineering Systems, Department of Mechanical Engineering and Engineering Science at the University of North Carolina at Charlotte. His research interests include orthopedic biomechanics, sports medicine and rehabilitation, and motion analysis.
PrEP Use Among Female Sex Workers: No Evidence for Risk Compensation

Background: Little is known about risk compensation among female sex workers (FSW) on HIV pre-exposure prophylaxis (PrEP), and self-report of sexual behaviours is subject to bias. Setting: Prospective observational PrEP demonstration study conducted among FSW in Cotonou, Benin. Methods: Over a period of 24 months, we assessed and compared trends in unprotected sex as measured by self-report (last 2 or 14 days), by detection of sexually transmitted infections (STI), and by vaginal detection of prostate-specific antigen and Y-chromosomal DNA, two biomarkers of semen exposure in the last 2 or 14 days, respectively. Trends were assessed and compared using a log-binomial regression that was simultaneously fit for all unprotected sex measures. Results: Of 255 participants, 120 (47.1%) completed their follow-up. Prevalence of STI decreased from 15.8% (95% confidence interval: 11.8%-21.0%) at baseline to 2.1% (95% confidence interval: 0.4%-10.2%) at 24 months of follow-up (p-trend=0.04). However, we observed no trend in self-report of unprotected sex in the last 2 (p=0.42) or 14 days (p=0.49), nor in prostate-specific antigen (p=0.53) or Y chromosomal DNA (p=0.25) over the same period. We observed no statistically significant difference between trends in self-report of unprotected sex and trends in biomarkers of semen exposure in the last 2 days (p=0.14) or in the last 14 days (p=0.29). Conclusion: We observed no evidence of risk compensation, and a decrease in STI among FSW on PrEP. PrEP intervention may be an opportunity to control STI among FSW. Future studies should assess risk compensation with biomarkers of semen exposure when possible.