Miracle-dz/UniFAR-FTUs huggingface dataset:
Latent Hierarchical Model of Temporal Structure for Complex Activity Classification

Modeling the temporal structure of sub-activities is an important yet challenging problem in complex activity classification. This paper proposes a latent hierarchical model (LHM) to describe the decomposition of complex activity into sub-activities in a hierarchical way. The LHM has a tree-structure, where each node corresponds to a video segment (sub-activity) at certain temporal scale. The starting and ending time points of each sub-activity are represented by two latent variables, which are automatically determined during the inference process. We formulate the training problem of the LHM in a latent kernelized SVM framework and develop an efficient cascade inference method to speed up classification. The advantages of our methods come from: 1) LHM models the complex activity with a deep structure, which is decomposed into sub-activities in a coarse-to-fine manner and 2) the starting and ending time points of each segment are adaptively determined to deal with the temporal displacement and duration variation of sub-activity. We conduct experiments on three datasets: 1) the KTH; 2) the Hollywood2; and 3) the Olympic Sports. The experimental results show the effectiveness of the LHM in complex activity classification. With dense features, our LHM achieves the state-of-the-art performance on the Hollywood2 dataset and the Olympic Sports dataset.
Recommending VideoLectures with Linear Regression

This paper describes our approach to the task 1 of the ECML PKDD 2011 VideoLectures.Net Recommender System Challenge. The task was to select a set of lectures to be recommended to a visitor of the VideoLecture.Net homepage after already seeing another lecture. Our proposed approach is a hybrid recom- mender system combining content and collaborative approaches. The core of the system is a linear regression model for predicting the rank of a lecture, whereas by rank we mean the lecture's position in the list of all lectures ordered by the interest of the visitor. Due to the complexity of the problem, the model could not be learned by a classical approach - instead, we had to employ the stochastic gradient descent optimization. The present paper furthermore, through evalua- tion, identifies and describes some interesting properties of the domain and of the algorithm that were crucial to achieve a higher prediction accuracy. The final accuracy of the model was enough to take the third place in the competition.
Correlation model of overall and local sitting comfort based on rating scales

To evaluate the perception of subjective sitting comfort requires overall comfort and local comfort as main indexes . The reliability and validity of a rating scale which was designed to measure local and overall comfort of two separate sitting postures on an adjustable chair was examined. The subjects included 20 males and 20 females, ranging in age from 22 to 32 (Mean=27, SD=4.7). Overall comfort was evaluated by direct or indirect method. The indirect overall comfort measure cannot substitute for direct measure from experimental data. As a result, the linear regression models were constructed between direct overall and local sitting comfort. The overall comfort can be predicted by three local comfort indexes.
Load-sensitive CPU Power Management for Web Search Engines

Web search engine companies require power-hungry data centers with thousands of servers to efficiently perform searches on a large scale. This permits the search engines to serve high arrival rates of user queries with low latency, but poses economical and environmental concerns due to the power consumption of the servers. Existing power saving techniques sacrifice the raw performance of a server for reduced power absorption, by scaling the frequency of the server's CPU according to its utilization. For instance, current Linux kernels include frequency governors i.e., mechanisms designed to dynamically throttle the CPU operational frequency. However, such general-domain techniques work at the operating system level and have no knowledge about the querying operations of the server. In this work, we propose to delegate CPU power management to search engine-specific governors. These can leverage knowledge coming from the querying operations, such as the query server utilization and load. By exploiting such additional knowledge, we can appropriately throttle the CPU frequency thereby reducing the query server power consumption. Experiments are conducted upon the TREC ClueWeb09 corpus and the query stream from the MSN 2006 query log. Results show that we can reduce up to ~24% a server power consumption, with only limited drawbacks in effectiveness w.r. t. a system running at maximum CPU frequency to promote query processing quality.
Essential roles of exploiting internal parallelism of flash memory based solid state drives in high-speed data processing

Flash memory based solid state drives (SSDs) have shown a great potential to change storage infrastructure fundamentally through their high performance and low power. Most recent studies have mainly focused on addressing the technical limitations caused by special requirements for writes in flash memory. However, a unique merit of an SSD is its rich internal parallelism, which allows us to offset for the most part of the performance loss related to technical limitations by significantly increasing data processing throughput. In this work we present a comprehensive study of essential roles of internal parallelism of SSDs in high-speed data processing. Besides substantially improving I/O bandwidth (e.g. 7.2×), we show that by exploiting internal parallelism, SSD performance is no longer highly sensitive to access patterns, but rather to other factors, such as data access interferences and physical data layout. Specifically, through extensive experiments and thorough analysis, we obtain the following new findings in the context of concurrent data processing in SSDs. (1) Write performance is largely independent of access patterns (regardless of being sequential or random), and can even outperform reads, which is opposite to the long-existing common understanding about slow writes on SSDs. (2) One performance concern comes from interference between concurrent reads and writes, which causes substantial performance degradation. (3) Parallel I/O performance is sensitive to physical data-layout mapping, which is largely not observed without parallelism. (4) Existing application designs optimized for magnetic disks can be suboptimal for running on SSDs with parallelism. Our study is further supported by a group of case studies in database systems as typical data-intensive applications. With these critical findings, we give a set of recommendations to application designers and system architects for exploiting internal parallelism and maximizing the performance potential of SSDs.
Dental Identification based on Teeth and Dental Works Matching for Bitewing Radiographs

This paper presents an enhanced human identification method based on matching both the contours of teeth and the shapes of dental works (DWs) using bitewing radiographs. To reduce teeth matching error due to unsatisfactory alignment of two incomplete tooth contours, we propose an enhanced contour alignment by pruning the outliers from both contours after they are aligned with the original contours using an adopted regular alignment method then realigning the pruned contours again, and a revised Hausdorff distance for measuring the distance between two contours. To compensate DW matching error based on the distance of DWs’ contours due to imperfect alignment of the teeth in which they reside, we propose using alignment-invariant Fourier descriptors of DWs’ contours as an additional feature. The distance between the contours of teeth and the distance between the shapes of DWs are weightily combined for improving identification matching. Experiments on a small database show that (1) matching with pruned tooth contours improved 8% accuracy for the top-1 retrieval when compared to the result of matching with original contours; (2) matching with the combined frequency and spatial features of DWs improved about 19% and 5% accuracy, respectively, when compared to matching with only the spatial and the frequency feature for the top-1 retrieval; and (3) matching with the pruned tooth contours and both the spatial and frequency features of DWs, the retrieval accuracy in identification matching achieved to 100% for the upper, the lower, and both jaws.
Does Gender Kuznets Curve Exist in South Asian Countries? Role of Gender Equality and Economic Development

This study aims to determine the relationship between gender equality and economic growth in major South Asian countries. This study suggests checking the gender Kuznets curve or whether the data support a linear, quadratic, or cubic gender Kuznets curve for major South Asian countries. We used time series data and covered the period from 1980 to 2019. We applied the Ng-Perron unit root test to check for non-stationary time series data. After the integration order is established, the autoregressive distributive lag (ARDL) model is used in three steps. The ARDL bound testing approach of covariance shows that Sri Lanka has an S-shaped Gender Cognition Curve (GKC), India has a Z-shaped GKC, Pakistan has an S-shape, and Bangladesh has an S-shape. is the -shaped GKC association. Periods of countries were considered. We also conclude that gender equality is not a direct result of development. Consequently, politicians with gender equality policies should subsidize women's employment in times of financial hardship.
Mind the chasm: A FishEye lens view of sustainable software engineering in UK higher education

Requirements that express the needs of all stakeholders and cover the key aspects of a software system (such as those addressing sustainability) are critical to the system’s successful development and adoption. For practitioners who want to develop sustainable software-intensive systems, it is also argued that software requirements are the key leverage point. But what do software developers know about broader sustainability and sustainability requirements in particular? As part of the University of Huddersfield’s ’Student as a Researcher’ initiative, this paper provides a FishEye Lens View on how novice software developers who design and develop software systems at software companies relate to the notions of sustainability and sustainability requirements. The study has found that although sustainability is valued highly by the novice software developers, the concept of sustainability and sustainability requirements are not fully understood. This lack of knowledge in the software industry and organizations must be addressed to enable delivery of truly sustainability enabling software systems.
Classification of Croatian winegrowing regions based on bioclimatic indices

The aim of this work was to classifie vine growing regions of Croatia using bioclimatic indices. For the analysis of climatic conditions, linear trends of bioclimatic indices were determined using meteorological observations for all avaliable climatological stations located in vine growing regions of Croatia. Analysis were performed for two different climatological periods: 1961-1990 and 1988-2017. Four commonly used bioclimatic indices were determined: the Winkler index, the Huglin index, Cool night index and Growing season average temperature.
Effect of Valve Port Gas Inertia on Valve Dynamics - Part II: Flow of Retardation at Valve Opening

T.J. Trella, U.S. Department of Tr~nsportation, Transportation Systems Center, Cambridge, Massachusetts 02142 and A mathematical model of non-linear reciprocating air-compressor discharge valve . system unsteady response was presented :n Part I. As a first step, to demonstrate the application of the unsteady modeling approach, a comparison of discharge discvalve response was made with a more popular quasi-steady modeling technique. For unsteady disc-valve response, contraction coefficients in the vicinity of the valve and ori~ice sections were determined from static measurements of discharge and liftforce coefficients. Under the assumptions that the contraction coefficients do not change appreciably from the static flow pattern during the dynamic response of the disc-valve, it is shown by comparing results of both modelin~ techniques that the inertia of the fluid, which initially retards tre flow between the disc-valve and seat, has a dominant effect on valve response for suction to pressure ratioscommo~ ly used in most air compressor designs. Lastly some calculated time histories are shown which illustrate the effects of mechanical disc-valve systems natural frequency, ~ass and stiffness, damping and valve diameter on unsteady flow and valve response.
Internal solitary waves observation and feature extraction based on wavelet transform by Sentinel-1A in Lombok Strait, Indonesia

Lombok Strait is an essential pathway in trans-oceanic water mass transport. Due to this water mass transport flowing over Indonesian waters, the current is known as Indonesian Throughflow (ITF), which plays a role in the transfer of warm water masses from the Pacific to the Indian Ocean annually. Lombok Strait has intensive characteristics of the internal waves (IWs) generation because of the strong current that passes through the complex bathymetry along the strait area. IWs with large amplitude and nonlinear properties are known as Internal Solitary Waves (ISW) that can be detected by Synthetic Aperture Radar (SAR) images. A Wavelet Transform method for ISW feature extraction was applied to SAR images by Sentinel-1A (C-band). ISW packet characteristics can be distinguished from other phenomena based on their geometrical structure and shape. ISW packet pattern consists of light and dark lines which decrease intensity from front to rear. SAR observation detected 5 parameters (phase speed, soliton numbers, wavelength, first crest length, and propagation direction). The arc-like ISW in the Lombok Strait propagated to the North of the sill with average phase speeds of about 2.13 m/s and was frequently detected during the northwest monsoon (NWM). The detected soliton number is less than 6 solitons per packet with a wavelength of about 1 – 4 km, and the first crest length varies from about 12.16 km to more than 100 km. ISW detected in Sentinel-1A images were located at the bathymetry about 800 meters around the Lombok Strait area.
Magnetopause Surface Reconstruction From Tangent Vector Observations

Entire fields of science, most notably in astrophysics, rely on line‐of‐sight observations. In planetary science and heliophysics, the techniques of soft X‐ray and energetic neutral atom imaging also produce line‐of‐sight measurements. An important question is whether the geometry of the surface, for example, the magnetopause, can be reconstructed using only line‐of‐sight observations from a single spacecraft. Under a broad range of conditions, the peak emission corresponds to the tangent to the boundary surface, such as the planetary surface or magnetopause, the so‐called limb brightening phenomenon. Thus, line‐of‐sight observations frequently provide information concerning the tangent to the surfaces being observed. We present an algorithm to reconstruct the cross section of the magnetopause using line‐of‐sight soft X‐ray observations (and, in principle, energetic neutral atom observations). The algorithm successfully reconstructs the cross section of the magnetopause in the orbit plane. The three‐dimensional magnetopause structure can be recovered from observations by a spacecraft whose orbit precesses around the magnetosphere.
The interchangeability of tandem queues with heterogeneous customers and dependent service times

Consider m queueing stations in tandem, with infinite buffers between stations, all initially empty, and an arbitrary arrival process at the first station. The service time of customer j at station i is geometrically distributed with parameter pi, but this is conditioned on the fact that the sum of the m service times for customer j is cj . Service times of distinct customers are independent. We show that for any arrival process to the first station the departure process from the last station is statistically unaltered by interchanging any of the pi 's. This remains true for two stations in tandem even if there is only a buffer of finite size between them. The well-known interchangeability of ·/M/1 queues is a special case of this result. Other special cases provide interesting new results.
Body mass index, abdominal fatness and pancreatic cancer risk: a systematic review and non-linear dose-response meta-analysis of prospective studies.

BACKGROUND Questions remain about the shape of the dose-response relationship between body mass index (BMI) and pancreatic cancer risk, possible confounding by smoking, and differences by gender or geographic location. Whether abdominal obesity increases risk is unclear. METHODS We conducted a systematic review and meta-analysis of prospective studies of the association between BMI, abdominal fatness and pancreatic cancer risk and searched PubMed and several other databases up to January 2011. Summary relative risks (RRs) were calculated using a random-effects model. RESULTS Twenty-three prospective studies of BMI and pancreatic cancer risk with 9504 cases were included. The summary RR for a 5-unit increment was 1.10 [95% confidence interval (CI) 1.07-1.14, I(2) = 19%] and results were similar when stratified by gender and geographic location. There was evidence of a non-linear association, P(non-linearity) = 0.005; however, among nonsmokers, there was increased risk even within the 'normal' BMI range. The summary RR for a 10-cm increase in waist circumference was 1.11 (95% CI 1.05-1.18, I(2) = 0%) and for a 0.1-unit increment in waist-to-hip ratio was 1.19 (95% CI 1.09-1.31, I(2) = 11%). CONCLUSIONS Both general and abdominal fatness increases pancreatic cancer risk. Among nonsmokers, risk increases even among persons within the normal BMI range.
Pathogenic seedborne viruses are rare but Phaseolus vulgaris endornaviruses are common in bean varieties grown in Nicaragua and Tanzania

Common bean (Phaseolus vulgaris) is an annual grain legume that was domesticated in Mesoamerica (Central America) and the Andes. It is currently grown widely also on other continents including Africa. We surveyed seedborne viruses in new common bean varieties introduced to Nicaragua (Central America) and in landraces and improved varieties grown in Tanzania (eastern Africa). Bean seeds, harvested from Nicaragua and Tanzania, were grown in insect-controlled greenhouse or screenhouse, respectively, to obtain leaf material for virus testing. Equal amounts of total RNA from different samples were pooled (30–36 samples per pool), and small RNAs were deep-sequenced (Illumina). Assembly of the reads (21–24 nt) to contiguous sequences and searches for homologous viral sequences in databases revealed Phaseolus vulgaris endornavirus 1 (PvEV-1) and PvEV-2 in the bean varieties in Nicaragua and Tanzania. These viruses are not known to cause symptoms in common bean and are considered non-pathogenic. The small-RNA reads from each pool of samples were mapped to the previously characterized complete PvEV-1 and PvEV-2 sequences (genome lengths ca. 14 kb and 15 kb, respectively). Coverage of the viral genomes was 87.9–99.9%, depending on the pool. Coverage per nucleotide ranged from 5 to 471, confirming virus identification. PvEV-1 and PvEV-2 are known to occur in Phaseolus spp. in Central America, but there is little previous information about their occurrence in Nicaragua, and no information about occurrence in Africa. Aside from Cowpea mild mosaic virus detected in bean plants grown from been seeds harvested from one region in Tanzania, no other pathogenic seedborne viruses were detected. The low incidence of infections caused by pathogenic viruses transmitted via bean seeds may be attributable to new, virus-resistant CB varieties released by breeding programs in Nicaragua and Tanzania.
Diversification and asymmetrical gene flow across time and space: lineage sorting and hybridization in polytypic barking frogs

Young species complexes that are widespread across ecologically disparate regions offer important insights into the process of speciation because of their relevance to how local adaptation and gene flow influence diversification. We used mitochondrial DNA and up to 28 152 genomewide single nucleotide polymorphisms from polytypic barking frogs (Craugastor augusti complex) to infer phylogenetic relationships and test for the signature of introgressive hybridization among diverging lineages. Our phylogenetic reconstructions suggest (i) a rapid Pliocene–Pleistocene radiation that produced at least nine distinct lineages and (ii) that geographic features of the arid Central Mexican Plateau contributed to two independent northward expansions. Despite clear lineage differentiation (many private alleles and high between‐lineage FST scores), D‐statistic tests, which differentiate introgression from ancestral polymorphism, allowed us to identify two putative instances of reticulate gene flow. Partitioned D‐statistics provided evidence that these events occurred in the same direction between clades but at different points in time. After correcting for geographic distance, we found that lineages involved in hybrid gene flow interactions had higher levels of genetic variation than independently evolving lineages. These findings suggest that the nature of hybrid compatibility can be conserved overlong periods of evolutionary time and that hybridization between diverging lineages may contribute to standing levels of genetic variation.
Shifting and scaling patterns from gene expression data

MOTIVATION During the last years, the discovering of biclusters in data is becoming more and more popular. Biclustering aims at extracting a set of clusters, each of which might use a different subset of attributes. Therefore, it is clear that the usefulness of biclustering techniques is beyond the traditional clustering techniques, especially when datasets present high or very high dimensionality. Also, biclustering considers overlapping, which is an interesting aspect, algorithmically and from the point of view of the result interpretation. Since the Cheng and Church's works, the mean squared residue has turned into one of the most popular measures to search for biclusters, which ideally should discover shifting and scaling patterns. RESULTS In this work, we identify both types of patterns (shifting and scaling) and demonstrate that the mean squared residue is very useful to search for shifting patterns, but it is not appropriate to find scaling patterns because even when we find a perfect scaling pattern the mean squared residue is not zero. In addition, we provide an interesting result: the mean squared residue is highly dependent on the variance of the scaling factor, which makes possible that any algorithm based on this measure might not find these patterns in data when the variance of gene values is high. The main contribution of this paper is to prove that the mean squared residue is not precise enough from the mathematical point of view in order to discover shifting and scaling patterns at the same time. CONTACT aguilar@lsi.us. es.