Miracle-dz/UniFAR-FTUs huggingface dataset:
VMCD: A Virtual Multi-Channel Disk I/O Scheduling Method for Virtual Machines

In the era of cloud computing and big data, virtualization is gaining great popularity in storage systems. Since multiple guest virtual machines (DomUs) are running on a single physical device, disk I/O fairness among DomUs and aggregated throughput remain the challenges in virtualized environments. Although several methods have been developed for disk I/O performance virtualization among multiple DomUs, most of them suffer from one or more of the following drawbacks. (1) A fair scheduling mechanism is missing when requests converge together from multiple queues. (2) Existing methods rely on better performance of the underlying storage system such as solid state drive (SSD). (3) Throughput and latency are not considered simultaneously. To address these disadvantages, this paper presents a virtual multi-channel of disk I/O (VMCD) method that can be built on top of an ordinary storage utility, which mitigates the interference among multiple DomUs by using separated virtual channel (V-Channel) and an I/O request queue for each DomU. In our VMCD, several mechanisms are employed to enhance the I/O performance, including a credit allocation mechanism, a global monitoring strategy, and a virtual multi-channel fair scheduling algorithm. The proposed techniques are implemented on the Xen virtual disk and evaluated on Linux guest operating systems. Experiments results show that VMCD increases fairness by 70 percent approximately compared with CFQ and Anticipatory schedulers, by 30 percent approximately compared with Deadline scheduler; and enhances bandwidth utilization by 28 percent approximately compared with CFQ and Anticipatory schedulers, by 37 percent compared with Deadline in the case of three or more virtual DomUs running on the same physical host.
Foamed Nanocomposites for EMI Shielding Applications

INTRODUCTION : The addition of nanoparticles having specific properties inside a matrix with different properties creates a novel material that exhibits hybrid and even new properties. The nanocomposites presented in this paper combine the properties of foamed polymers (inexpensive, lightweight, easy to mould into any desired shape, etc.) with those of carbon nanotubes (CNTs). The addition of any conductive nanoparticles to an otherwise insulating matrix leads to a significant increase of the electrical conductivity. But CNTs have a very high aspect ratio; a much lower content of CNTs is therefore required to get the same conductivity increase as the one obtained with more compact nanoparticles. This is especially interesting for EMI shielding materials since, as will be explained in further details in this chapter, it is desirable for such materials to have a high conductivity but a low dielectric constant, in order to minimize the electromagnetic power outside the shield casing but also to minimize the power reflected back inside the casing, as is explained in section 2. In particular, two parameters of interest when comparing shielding materials are detailed and discussed. The polymer/CNTs nanocomposites were fabricated and characterized using a two-step diagnostic method. They were first characterized in their solid form, i.e. before the foaming process and the most interesting polymer matrices (with embedded CNTs) could be selected. This way, only the promising blends were foamed, therefore avoiding the unnecessary fabrication of a number of foams. These selected blends were foamed and then characterized. The samples, both solid and foamed, are described and their fabrication processes are briefly explained in section 3 while the characterization methods are shown in section 4. A simple electrical model is given and explained in section 5 and an optimized topology for the foams is also proposed in the second part of the same section. The measurement results for the solids and for the mono-layered and multi-layered foams are summarized and discussed in section 6. They are then compared to results obtained using the electrical model presented in the previous section and they are also correlated to rheological characterizations.
Pattern formation during capillary rising of a fluid front into a granular media

We report results concerning the pattern formation during the capillary rising of a fluid front into a dense dry granular media. The system consists in a modified Hele-Shaw cell filled with grains of different gradings and confined in a narrow gap between the glass plates. This assembly is vertically installed over a water reservoir to allow an ascending front of liquid to percolate into the granular media. We acquire digital images of the liquid/air front which are treated by means of imaging analysis techniques. Thus, we are able to assess the temporal evolution of the air/liquid boundary profiles. We measure the roughness of the profiles, using a detrended fluctuation analysis technique, to obtain their fractal dimension. We compare our results with similar experiments reported in literature considering fluid displacement into heterogeneous media and directed percolation theory. However, the range of values for the Hurst exponent obtained from our experiments are odd to the measured/predicted values in experiments or theory.
Hierarchical Segmentation: Finding Changes in a Text Signal

This paper describes a signal processing algorithm which discovers the hierarchical organization of a document or media presentation. We use latent semantic indexing to describe the semantic content of the signal, and scalespace segmentation to describe its features at many different scales. We represent the semantic content of the document as a signal that varies through the document. We lowpass filter this signal to compute the document’s semantic path at many different time scales and then look for changes. The changes are sorted by their strength to form a hierarchical segmentation. We present results from a text document and a video transcript. 1. THE PROBLEM As prices decline and storage and computational horsepower increase, we will soon be swamped in multimedia data. Unfortunately, given an audio or a video signal there is little information readily available that can help us find our way around such a time-based signal. Technical papers are structured into major and minor headings, imposing a hierarchical structure. Often professional or high-quality audio–visual (AV) presentations are also structured. However, this information is hidden in the signal. Our goal is to use the semantic information in the AV signal to create a hierarchical table of contents that describes the associated signal. Towards this end we combine two powerful concepts: scale space (SS) filtering and Latent Semantic Indexing (LSI). We use LSI to provide a continuously valued feature that describes the semantic content of an AV signal. By doing this we reduce the dimensionality of the problem and, more importantly, we address synonymy and polysemy as LSI does. The combined approach remains language independent. We use scale-space techniques to represent the semantic signal over many different time scales. We are looking for changes in the signal and scale space allows us to talk about features of the document that span from a single sentence to entire chapters. The scale parameter specifies the level of detail for our analysis. Intuitively, at small scales we are looking at the individual trees, and at large scales we are seeing the entire forest. We look at a wide range of scales to determine when the content of the signal has changed. In Section 5 we use Latent Semantic Indexing (LSI) as a means to describe the semantic content of a signal.
Journal abstracts from current research in the field of child and adolescent mental health

Gonzales NA, Coxe S, Roosa MW, White RMB, Knight GP, Zeiders KH and Saenz D (2011) Economic hardship, neighborhood context, and parenting: Prospective effects on Mexican–American adolescent's mental health. American Journal of Community Psychology 47(1–2): 98–113 O’Kane D (2011) A phenomenological study of child and adolescent mental health consultation in primary care. Journal of Psychiatric and Mental Health Nursing 18(2): 185–188 Sentse M, Ormel J, Veenstra R, Verhulst FC and Oldehinkel AJ (2011) Child temperament moderates the impact of parental separation on adolescent mental health: The trails study. Journal of Family Psychology 25(1): 97–106 Leo RJ, Srinivasan SP and Parekh S (2011) The role of the mental health practitioner in the assessment and treatment of child and adolescent chronic pain. Child and Adolescent Mental Health 16(1): 2–8 James AC, Winmill L, Anderson C and Alfoadari K (2011) A preliminary study of an extension of a community dialectic behaviour therapy (DBT) programme to adolescents in the looked after care system. Child and Adolescent Mental Health 16(1): 9–13 Flouri E, Hickey J, Mavroveli S and Hurry J (2011) Adversity, emotional arousal, and problem behaviour in adolescence: The role of non-verbal cognitive ability as a resilience promoting factor. Child and Adolescent Mental Health 16(1): 22–29 Paradis AD, Giaconia RM, Reinherz HZ, Beardslee WR, Ward KE and Fitzmaurice GM (2011) Adolescent family factors promoting healthy adult functioning: A longitudinal community study. Child and Adolescent Mental Health 16(1): 30–37 Webster-Stratton C, Rinaldi J and Reid JM (2011) Long-term outcomes of Incredible Years parenting program: Predictors of adolescent adjustment. Child and Adolescent Mental Health 16(1): 38–46 Baruch G, Vrouva I and Wells C (2011) Outcome findings from a parent training programme for young people with conduct problems. Child and Adolescent Mental Health 16(1): 47–54 Davis Kenaley BL and Williams NJ (2011) A preliminary evaluation: Demographic and clinical profiles and changes in functioning in children receiving psychosocial rehabilitation. Children and Youth Services Review 33(2): 301–307
EXPLODE : A Lightweight , General Approach to Finding Serious Errors in Storage Systems

File systems, RAID systems, and applications that require data consistency, among others, assure data integrity by carefully forcing valuable data to stable storage. Unfortunately, verifying that a system can recover from a crash to a valid state at any program counter is very difficult. Previous techniques for finding data integrity bugs have been heavyweight, requiring extensive effort for each OS and file system to be checked. We demonstrate a lightweight, flexible, easyto-apply technique by developing a tool called Explode and show how we used it to find 25 serious bugs in eight Linux file systems, Linux software RAID 5, Linux NFS, and three version control systems.
Informatics and Data Mining Tools and Strategies for the Human Connectome Project

The Human Connectome Project (HCP) is a major endeavor that will acquire and analyze connectivity data plus other neuroimaging, behavioral, and genetic data from 1,200 healthy adults. It will serve as a key resource for the neuroscience research community, enabling discoveries of how the brain is wired and how it functions in different individuals. To fulfill its potential, the HCP consortium is developing an informatics platform that will handle: (1) storage of primary and processed data, (2) systematic processing and analysis of the data, (3) open-access data-sharing, and (4) mining and exploration of the data. This informatics platform will include two primary components. ConnectomeDB will provide database services for storing and distributing the data, as well as data analysis pipelines. Connectome Workbench will provide visualization and exploration capabilities. The platform will be based on standard data formats and provide an open set of application programming interfaces (APIs) that will facilitate broad utilization of the data and integration of HCP services into a variety of external applications. Primary and processed data generated by the HCP will be openly shared with the scientific community, and the informatics platform will be available under an open source license. This paper describes the HCP informatics platform as currently envisioned and places it into the context of the overall HCP vision and agenda.
iSwitch: Coordinating and optimizing renewable energy powered server clusters

Large-scale computing systems such as data centers are facing increasing pressure to cap their carbon footprint. Integrating emerging clean energy solutions into computer system design therefore gains great significance in the green computing era. While some pioneering work on tracking variable power budget show promising energy efficiency, they are not suitable for data centers due to lack of performance guarantee when renewable generation is low and fluctuant. In addition, our characterization of wind power behavior reveals that data centers designed to track the intermittent renewable power incur up to 4X performance loss due to inefficient and redundant load matching activities. As a result, mitigating operational overhead while still maintaining desired energy utilization becomes the most significant challenge in managing server clusters on intermittent renewable energy generation. In this paper we take a first step in digging into the operational overhead of renewable energy powered data center. We propose iSwitch, a lightweight server power management that follows renewable power variation characteristics, leverages existing system infrastructures, and applies supply/load cooperative scheme to mitigate the performance overhead. Comparing with state-of-the-art renewable energy driven system design, iSwitch could mitigate average network traffic by 75%, peak network traffic by 95%, and reduce 80% job waiting time while still maintaining 96% renewable energy utilization. We expect that our work can help computer architects make informed decisions on sustainable and high-performance system design.
Power minimization for parallel real-time systems with malleable jobs and homogeneous frequencies

In this work, we investigate the potential benefit of parallelization for both meeting real-time constraints and minimizing power consumption. We consider malleable Gang scheduling of implicit-deadline sporadic tasks upon multiprocessors. By extending schedulability criteria for malleable jobs to DPM/DVFS-enabled multiprocessor platforms, we are able to derive an offline polynomial-time optimal processor/frequency-selection algorithm. Simulations of our algorithm on randomly generated task systems executing on platforms having up to 16 processing cores show that the theoretical power consumption is reduced by a factor of 36 compared to the optimal non-parallel approach.
Measures of Emotional and Motivational Processes Activated by Stress or Comfort Conditions

Under stress conditions, obtained in the field or experimentally induced, changes occur in the nature and intensity of affective processes (emotions, motivations). Symmetrical changes occur under opposite (comfort) conditions. One of the first procedures for determining temporary stress states consists of administering difficult logical tasks (15 minutes), with erroneous or ambiguous feedback and social pressure. For example, some very difficult Raven Matrices were individually assigned to participants. The first two authors later found another procedure equally effective and even more advantageous for certain aspects: the “drawing recollection” of personal stressful experiences. The corresponding comfort treatments are, firstly, a progressive relaxation session in penumbra; or, in the second case, the “drawing recollection” of personal pleasant and positive experiences. To assess the emotional changes, we prepared seven-point bipolar scales centering on the main opposing emotions. As regards motivations, we used a list of nine motivational systems [1]. The whole set of items made up the so-called Self-Appraisal Scales, administered before and after a specific treatment, thereby obtaining a measure through the differences between the two successive assessments. Factor analyses were conducted for selecting the main emotional and motivational factors. Affective reverberations on cognitive processes were also studied and measured.
DDB Expert: A Recommender for Distributed Databases Design

This paper proposes a framework based on expert systems for distributed database design. The DB fragmentation advisor recommends table fragmentation or full/partial replication through DB schema analysis, DB workload analysis and DB statistics. The advisor is low cost, has a low memory footprint, and is very fast. The framework is flexible since it's open to workload changes with new business requirements or query/interaction's frequency changes as well as recommender enhancements with new rules.
Morning Surge in Blood Pressure as a Predictor of Silent and Clinical Cerebrovascular Disease in Elderly Hypertensives: A Prospective Study

Background—Cardiovascular events occur most frequently in the morning hours. We prospectively studied the association between the morning blood pressure (BP) surge and stroke in elderly hypertensives. Methods and Results—We studied stroke prognosis in 519 older hypertensives in whom ambulatory BP monitoring was performed and silent cerebral infarct was assessed by brain MRI and who were followed up prospectively. The morning BP surge (MS) was calculated as follows: mean systolic BP during the 2 hours after awakening minus mean systolic BP during the 1 hour that included the lowest sleep BP. During an average duration of 41 months (range 1 to 68 months), 44 stroke events occurred. When the patients were divided into 2 groups according to MS, those in the top decile (MS group; MS ≥55 mm Hg, n=53) had a higher baseline prevalence of multiple infarcts (57% versus 33%, P =0.001) and a higher stroke incidence (19% versus 7.3%, P =0.004) during the follow-up period than the others (non-MS group; MS <55 mm Hg, n=466). After they were matched for age and 24-hour BP, the relative risk of the MS group versus the non-MS group remained significant (relative risk=2.7, P =0.04). The MS was associated with stroke events independently of 24-hour BP, nocturnal BP dipping status, and baseline prevalence of silent infarct (P =0.008). Conclusions—In older hypertensives, a higher morning BP surge is associated with stroke risk independently of ambulatory BP, nocturnal BP falls, and silent infarct. Reduction of the MS could thus be a new therapeutic target for preventing target organ damage and subsequent cardiovascular events in hypertensive patients.
Optical detection of structural changes in human carotid atherosclerotic plaque

Background: Arterial bifurcations are commonly the sites of developing atherosclerotic plaque that lead to arterial occlusions and plaque rupture (myocardial infarctions and strokes). Laser induced fluorescence (LIF) spectroscopy provides an effective nondestructive method supplying spectral information on extracellular matrix (ECM) protein composition, specifically collagen and elastin. Purpose: To investigate regional differences in the ECM proteins -- collagen I, III and elastin in unstable plaque by analyzing data from laser-induced fluorescence spectroscopy of human carotid endarterectomy specimens. Methods: Gels of ECM protein extracts (elastin, collagen types I & III) were measured as reference spectra and internal thoracic artery segments (extra tissue from bypass surgery) were used as tissue controls. Arterial segments and the endarterectomy specimens (n=21) were cut into 5mm cross-sectional rings. Ten fluorescence spectra per sampling area were then recorded at 5 sites per ring with argon laser excitation (357nm) with a penetration depth of 200 μm. Spectra were normalized to maximum intensity and analyzed using multiple regression analysis. Tissue rings were fixed in formalin (within 3 hours of surgery), sectioned and stained with H&E or Movat's Pentachrome for histological analysis. Spectroscopy data were correlated with immunohistology (staining for elastin, collagen types I, III and IV). Results: Quantitative fluorescence for the thoracic arteries revealed a dominant elastin component on the luminal side -- confirmed with immunohistology and known artery structure. Carotid endarterectomy specimens by comparison had a significant decrease in elastin signature and increased collagen type I and III. Arterial spectra were markedly different between the thoracic and carotid specimens. There was also a significant elevation (p<0.05) of collagen type I distal to the bifurcation compared to proximal tissue in the carotid specimens. Conclusion: Fluorescence spectroscopy is an effective method for evaluating ECM (collagen and elastin) associated with vascular remodeling despite the considerable variability in the plaque structure. Consistent regional differences were detected in the carotid specimens.
Denaturing gradient gel electrophoresis profiles of 16S rRNA-defined populations inhabiting a hot spring microbial mat community

Denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA gene segments was used to profile microbial populations inhabiting different temperature regions in the microbial mat community of Octopus Spring, Yellowstone National Park. DGGE allowed a rapid evaluation of the distributions of amplifiable sequence types. Profiles were essentially identical within regions of the mat defined by one temperature range but varied between sites with different temperature ranges. Individual DGGE bands were sequenced, and the sequences were compared with those previously obtained from the mat by cloning and from cultivated Octopus Spring isolates. Two known cyanobacterial populations and one known green nonsulfur bacterium-like population were detected by DGGE, as were many new cyanobacterial and green nonsulfur and green sulfur bacterium-like populations and a novel bacterial population of uncertain phylogenetic affiliation. The distributions of several cyanobacterial populations compared favorably with results obtained previously by oligonucleotide probe analyses and suggest that adaptation to temperature has occurred among cyanobacteria which are phylogenetically very similar.
Bayesian Combinatorial Auctions: Expanding Single Buyer Mechanisms to Many Buyers

For Bayesian combinatorial auctions, we present a general framework for approximately reducing the mechanism design problem for multiple buyers to the mechanism design problem for each individual buyer. Our framework can be applied to any setting which roughly satisfies the following assumptions: (i) The buyer's types must be distributed independently (not necessarily identically). (ii) The objective function must be linearly separable over the set of buyers (iii) The supply constraints must be the only constraints involving more than one buyer. Our framework is general in the sense that it makes no explicit assumption about any of the following: (i) The buyer's valuations (e.g., sub modular, additive, etc). (ii) The distribution of types for each buyer. (iii) The other constraints involving individual buyers (e.g., budget constraints, etc). We present two generic $n$-buyer mechanisms that use $1$-buyer mechanisms as black boxes. Assuming that we have an$\alpha$-approximate $1$-buyer mechanism for each buyer\footnote{Note that we can use different $1$-buyer mechanisms to accommodate different classes of buyers. } and assuming that no buyer ever needs more than $\frac{1}{k}$ of all copies of each item for some integer $k \ge 1$, then our generic $n$-buyer mechanisms are $\gamma_k\cdot\alpha$-approximation of the optimal$n$-buyer mechanism, in which $\gamma_k$ is a constant which is at least $1-\frac{1}{\sqrt{k+3}}$. Observe that $\gamma_k$ is at least $\frac{1}{2}$ (for $k=1$) and approaches $1$ as $k$ increases. As a byproduct of our construction, we improve a generalization of prophet inequalities. Furthermore, as applications of our main theorem, we improve several results from the literature.