Miracle-dz/UniFAR-FTUs huggingface dataset:
Decomposing DAGs into spanning trees: A new way to compress transitive closures

Let G(V, E) be a digraph (directed graph) with n nodes and e edges. Digraph G* = (V, E*) is the reflexive, transitive closure if (v, u) ∈ E* iff there is a path from v to u in G. Efficient storage of G* is important for supporting reachability queries which are not only common on graph databases, but also serve as fundamental operations used in many graph algorithms. A lot of strategies have been suggested based on the graph labeling, by which each node is assigned with certain labels such that the reachability of any two nodes through a path can be determined by their labels. Among them are interval labelling, chain decomposition, and 2-hop labeling. However, due to the very large size of many real world graphs, the computational cost and size of labels using existing methods would prove too expensive to be practical. In this paper, we propose a new approach to decompose a graph into a series of spanning trees which may share common edges, to transform a reachability query over a graph into a set of queries over trees. We demonstrate both analytically and empirically the efficiency and effectiveness of our method.
Mixtures of Monotone Networks for Prediction

In many data mining applications, it is a priori known that the target function should satisfy certain constraints imposed by, for example, economic theory or a human-decision maker. In this paper we consider partially monotone prediction problems, where the target variable depends monotonically on some of the input variables but not on all. We propose a novel method to construct prediction models, where monotone dependences with respect to some of the input variables are preserved by virtue of construction. Our method belongs to the class of mixture models. The basic idea is to convolute monotone neural networks with weight (kernel) functions to make predictions. By using simulation and real case studies, we demonstrate the application of our method. To obtain sound assessment for the performance of our approach, we use standard neural networks with weight decay and partially monotone linear models as benchmark methods for comparison. The results show that our approach outperforms partially monotone linear models in terms of accuracy. Furthermore, the incorporation of partial monotonicity constraints not only leads to models that are in accordance with the decision maker’s expertise, but also reduces considerably the model variance in comparison to standard neural networks with weight decay. Keywords— mixture models, monotone neural networks, partially monotone models, partially monotone problems.
Performance comparison of MRT and ZF for single cell downlink massive MIMO system

The next generation of wireless communications high data rate and link with high reliability became main factors in measuring the performance of system. Therefore; massive Multiple Input Multiple Output systems (massive MIMO) will be a promising technology for fifth generation wireless communication so it will provide acceptable data rate and high reliability. This paper focuses on eliminating/mitigating the effect of Multi User Interference (MUI) (an interference results from other user in same cell). The MUI has one of the major impact factors in decreasing performance (achievable sum rate) of cellular communication system when more users access to the wireless link. It presents performance comparison of two linear precoding techniques which are Maximum Ratio Transmission (MRT) and Zero Forcing (ZF) for downlink massive multiple input multiple output System over perfect channel state information depending on vector normalization and matrix normalization methods at high and low downlink transmit power. Simulations results show that using linear precoding techniques and increasing number of base station antennas enhance system performance and vector normalization and matrix normalization for ZF gives better performances at high power while vector normalization and matrix normalization for MRT gives better performance at low power.
Deep BVR photometry of the Chandra Deep Field South from the COMBO-17 survey

We report on deep multi-color imaging ($R_{5\sigma} = 26$) of the Chandra Deep Field South, obtained with the Wide Field Imager (WFI) at the MPG/ESO 2.2 m telescope on La Silla as part of the multi-color survey COMBO-17. As a result we present a catalogue of 63 501 objects in a field measuring $31\farcm5 \times 30\arcmin$ with astrometry and BVR photometry. A sample of 37 variable objects is selected from two-epoch photometry. We try to give interpretations based on color and variation amplitude.
A service policy for real-time customers with (m,k) firm deadlines

The problem of scheduling multiple streams of realtime customers is addressed in this paper. The paper first introduces the notion of (m, k)-firm deadlines to better characterize the timing constraints of real-time streams. More specifically, a stream is said to have (m, k)-firm deadlines if at least m out of any k consecutive customers must meet their deadlines. Note that, the notion of (m, k)-firm deadlines is a generalization of firm and soft deadlines. In particular, m=k=1 characterizes a stream with firm deadlines. A large value for k with m/k equal to the maximum allowable loss percentage can be used to represent a stream with soft deadlines. A stream with (m, k)-firm deadlines will experience a dynamic failure if fewer than m out of any k consecutive customers meet their deadlines. The paper proposes a policy for scheduling N such streams on a single server to reduce the probability of dynamic failure. The basic idea of the proposed policy is to assign higher priorities to customers from streams which have had too many recent missed deadlines. The paper proposes a heuristic for assigning these priorities. The effectiveness of the approach is evaluated through simulation under various customer arrival and service patterns. The evaluation shows that by properly assigning the priorities one can substantially reduce the probability of dynamic failure. <<ETX>>
Potential field based approach for coordinate exploration with a multi-robot team

In this paper we introduce a new distributed algorithm for the exploration of an unknown environment with a team of mobile robots. The objective is to explore the whole environment as fastest as possible. The proposed approach is based on the potential field method. The advantages of using this method are several and well known, but the presence of many local minima does not assure the exploration of the entire environment. Our idea is to preserve these advantages but overcome the problem of local minima by introducing a leader in the team which has a different control law, unaffected by this problem. Furthermore, we consider also the case of several local leaders, dynamically selected on the basis of a hierarchy within the team. Extensive simulations are presented to evaluate the performance of the algorithm. In particular, the results are compared with the exploration obtained by a potential field approach without leaders.
Modelling a Complex Production Scheduling Problem : Optimization Techniques

In this thesis, and complex real world problem, a sequence dependent scheduling of different product orders on a number of lines is addressed. Changeover costs occur between product orders belonging to different product groups. The operational research cycle is employed exploring different optimization techniques as mathematical modelling and heuristic approaches. The identification, implementation and demonstration of the techniques are supported with numerical results from experiments. One combination of different solution techniques is put forward. Some suggestions are done for reducing cost and increasing productivity.
PRL-3 Phosphatase Is Implicated in Ovarian Cancer Growth

Purpose: The PRL-3 phosphatase has been found expressed at higher levels in metastasis than in primary tumors of patients with colorectal cancer. In the present study, we evaluated the expression of PRL-3 in ovarian cancer tissue and its role in ovarian cancer cell growth. Experimental Design: PRL-3 phosphatase expression was evaluated in 84 ovarian tumor samples. PRL-3 expression has been knocked down using specific small interfering RNAs to determine its role in ovarian cancer cell growth in vitro. Results: In ovarian cancers, PRL-3 expression correlates with disease progression, being higher in advanced (stage III) than in early (stage I) tumors. In situ measurements of PRL-3 expression showed that it was confined to the epithelial neoplastic cells. The molecular mechanism underlying PRL-3 overexpression in ovarian cancers is independent from amplification of the corresponding genomic locus. Ovarian cancer cells growing in culture have high levels of expression of this phosphatase. PRL-3–specific knockdown using small interfering RNA severely impaired the growth of cells without affecting the expression of the closely related homologue PRL-1. Intriguingly, the growth of human colon carcinoma cells expressing lower levels of the PRL-3 was not affected by the PRL-3 knockdown. Conclusions: Altogether, these results show that PRL-3 expression is associated with ovarian cancer progression and point to a key role for this phosphatase in the control of ovarian cancer cells growth. This strongly suggests that PRL-3 should be considered as a target for the discovery of new anticancer agents to be tested against this malignancy.
Design Guidelines for Agent Based Model Visualization

In the field of agent-based modeling (ABM), visualizations play an important role in identifying, communicating and understanding important behavior of the modeled phenomenon. However, many modelers tend to create ineffective visualizations of Agent Based Models (ABM) due to lack of experience with visual design. This paper provides ABM visualization design guidelines in order to improve visual design with ABM toolkits. These guidelines will assist the modeler in creating clear and understandable ABM visualizations. We begin by introducing a non-hierarchical categorization of ABM visualizations. This categorization serves as a starting point in the creation of an ABM visualization. We go on to present well-known design techniques in the context of ABM visualization. These techniques are based on Gestalt psychology, semiology of graphics, and scientific visualization. They improve the visualization design by facilitating specific tasks, and providing a common language to critique visualizations through the use of visual variables. Subsequently, we discuss the application of these design techniques to simplify, emphasize and explain an ABM visualization. Finally, we illustrate these guidelines using a simple redesign of a NetLogo ABM visualization. These guidelines can be used to inform the development of design tools that assist users in the creation of ABM visualizations.
Deterministic multi-channel information exchange

In this paper, we study the information exchange problem on a set of multiple access channels: k arbitrary nodes have information they want to distribute to the entire network via a shared medium partitioned into channels. We present algorithms and lower bounds on the time and channel complexity for disseminating these k information items in a single-hop network of n nodes. More precisely, we devise a deterministic algorithm running in asymptotically optimal time O(k) using O(n(log (k)/k)) channels if k less or equal to (1/6) * log n and O(log(1+p) (n/k) channels otherwise, where p>0 is an arbitrarily small constant. In addition, we show that Omega(n(Ω(1/k))+logk n) channels are necessary to achieve this time complexity.
Actin-driven cell dynamics probed by Fourier transform light scattering

We applied the newly developed Fourier transform light scattering (FTLS) to study dynamic light scattering in single live cells, at a temporal scale of seconds to hours. The nanoscale cell fluctuations were measured with and without the active actin contribution. We found experimentally that the spatio-temporal signals rendered by FTLS reveal interesting cytoskeleton dynamics in glial cells (the predominant cell type in the nervous system). The active contribution of actin cytoskeleton was obtained by modulating its dynamic properties via Cytochalasin-D, a drug that inhibits actin polymerization/depolymerization.
Calcium-sensing receptor silencing in colorectal cancer is associated with promoter hypermethylation and loss of acetylation on histone 3

The calcium‐sensing receptor (CaSR) is suggested to mediate the antiproliferative effects of calcium in colon. However, in colorectal cancer (CRC) the expression of the CaSR is silenced and the underlying mechanisms leading to its loss are poorly understood. We investigated whether loss of the CaSR expression in colorectal tumors is caused by DNA hypermethylation and imbalance of transcriptionally permissive/repressive histone alterations. We observed significantly lower CaSR mRNA expression (n = 65, p < 0.001) in colorectal tumors compared with the adjacent mucosa from the same patient. Immunofluorescence staining confirmed downregulation of the CaSR protein also. The CaSR promoter was methylated to a greater extent in tumors compared with adjacent mucosa as determined by bisulfite sequencing (n = 20, p < 0.01) and by pyrosequencing (n = 45, p < 0.001), and methylation correlated inversely with mRNA expression (n = 20, ρ = −0.310, p < 0.05 and n = 45, ρ = −0.588, p < 0.001). Treatments with 5‐aza‐2′‐deoxycytidine (DAC), a DNA methyltransferase inhibitor and/or with two different histone deacetylase inhibitors, trichostatin A (TSA) or suberoylanilide hydroxamic acid (SAHA) restored the expression of CaSR in colon cancer cells. Restored CaSR expression in Coga1A and HT29 cells was functional. Inhibition of lysine‐specific demethylase 1 (LSD1) to prevent demethylation of mono‐ and dimethylated H3K4, increased CaSR expression only marginally. Our data show that hypermethylation of the CaSR promoter and H3K9 deacetylation, but not H3K4me2 demethylation are important factors that cause silencing of the CaSR in colorectal cancer.
Developing a Real-Time Identify-and-Locate System for the Blind

It is safe to say that computer vision holds great potential for providing a broad range of benefits to the blind in the foreseeable future. But despite the rapid advances in computer hardware and vision algorithms, robust, self-contained functional systems that can be used by the blind for ‘identify-and-locate’ tasks are not yet available. This paper describes the challenges encountered and experience gained in building such a functional ‘identify-and-locate’ system by a group of undergraduates in the Gemstone Program at the University of Maryland, College Park. The greatest resistance to getting this task off the starting block was the need to simultaneously tackle several technical challenges requiring a range of expertise. These included developing a robust and real-time computer vision algorithm, a voice recognition and speech output system, a directional feedback interface, and the means to integrate these components into a single functional unit. With access to a pool of students with differing skills and backgrounds, we overcame the initial resistance. The bulk of the project was completed over a one year period, resulting in a prototype system that the blind can use in controlled environments to reliably identify and locate objects and signs within seconds.
Detecting the Stochastic Gravitational Wave Background Using Pulsar Timing

The direct detection of gravitational waves is a major goal of current astrophysics. We provide details of a new method for detecting a stochastic background of gravitational waves using pulsar timing data. Our results show that regular timing observations of 40 pulsars each with a timing accuracy of 100 ns will be able to make a direct detection of the predicted stochastic background from coalescing black holes within 5 years. With an improved prewhitening algorithm, or if the background is at the upper end of the predicted range, a significant detection should be possible with only 20 pulsars.
Speaker Identification using MFCC-Domain Support Vector Machine

Speech recognition and speaker identification are important for authentication and verification in security purpose, but they are difficult to achieve. Speaker identification methods can be divided into text-independent and text-dependent. This paper presents a technique of text-dependent speaker identification using MFCC-domain support vector machine (SVM). In this work, melfrequency cepstrum coefficients (MFCCs) and their statistical distribution properties are used as features, which will be inputs to the neural network. This work firstly used sequential minimum optimization (SMO) learning technique for SVM that improve performance over traditional techniques Chunking, Osuna. The cepstrum coefficients representing the speaker characteristics of a speech segment are computed by nonlinear filter bank analysis and discrete cosine transform. The speaker identification ability and convergence speed of the SVMs are investigated for different combinations of features. Extensive experimental results on several samples show the effectiveness of the proposed approach.
Human behavior recognition using a context-free grammar

Abstract. Automatic recognition of human activities and behaviors is still a challenging problem for many reasons, including limited accuracy of the data acquired by sensing devices, high variability of human behaviors, and gap between visual appearance and scene semantics. Symbolic approaches can significantly simplify the analysis and turn raw data into chains of meaningful patterns. This allows getting rid of most of the clutter produced by low-level processing operations, embedding significant contextual information into the data, as well as using simple syntactic approaches to perform the matching between incoming sequences and models. We propose a symbolic approach to learn and detect complex activities through the sequences of atomic actions. Compared to previous methods based on context-free grammars, we introduce several important novelties, such as the capability to learn actions based on both positive and negative samples, the possibility of efficiently retraining the system in the presence of misclassified or unrecognized events, and the use of a parsing procedure that allows correct detection of the activities also when they are concatenated and/or nested one with each other. An experimental validation on three datasets with different characteristics demonstrates the robustness of the approach in classifying complex human behaviors.
Morphology, Structure, and Ontogeny of Trichomes of the Grape Genus (Vitis, Vitaceae)

Trichomes are widely distributed on surfaces of different organs in the grape genus Vitis and are of taxonomic utility. To explore the morphology, structure and ontogeny of Vitis trichomes, we investigated the diversity and distribution of trichomes in 34 species of Vitis. Two main types of trichomes in Vitis are documented: non-glandular and glandular. Within non-glandular trichomes, ribbon and simple trichomes are found on different vegetative plant organs. The morphology and ontogeny of these types of trichomes are further examined with light microscopy and scanning electron microscopy. The ultrastructure of the glandular trichomes is explored with transmission electron microscopy. The ribbon trichomes are twisted, greatly elongated and unicellular, and this trichome type may be a morphological synapomorphy of Vitis and its closest tropical relative Ampelocissus and Pterisanthes in Vitaceae. The simple trichomes are documented in most species sampled in the genus. The glandular trichomes are multicellular, non-vascularized and composed of both epidermis and subjacent layers. We show that prickles occurring along the stems and petioles of Vitis davidii are modified glandular trichomes. We observed that glandular trichomes of V. romanetii secrete mucilage and volatile substances which trap insectes on the glands. Transmission electron microscopy indicates that metabolic products accumulate in vacuoles, the cytoplasm and intercellular spaces. We infer that glandular trichomes and young prickles are involved in the secretion of these metabolic products and the intercellular spaces may be the places of temporary storage of these secretions.
Grazing regimes and plant reproduction in semi-natural grasslands

The dominating grazing regime in semi-natural grasslands today is continuous grazing throughout the season, and a high grazing pressure is often advised in order to avoid litter accumulation. Traditional management, on the other hand, included late mowing and grazing, which favoured plant flowering and seed production. This thesis studies the effects of alternative grazing regimes that may ecologically mimic traditional management. The ingoing papers examines: 1) Plant reproduction under late onset of grazing compared to continuous grazing; 2) The tradeoff between disturbance and competition for plant seed production and establishment; 3) Effects of increased flower density in late grazed grasslands on pollinator abundance, visitation rate, and pollen limitation; 4) The impact of landscape, habitat, population, and management on pollination, reproduction, and population structure of Primula veris. The studies were performed by using grazing and pollination experiments combined with estimates of habitat and landscape properties. Late grazing enhanced the fruit set without increasing the litter depth. The management effect for individual plant species depended mainly on the species’ phenology of reproduction. Late grazing and 1-yr grazing interruption increased seed production linearly, but reduced seedling establishment as a threshold function. The net effect was an increased seedling density and, after six years, species density. Increased flower density in late grazing attracted more pollinators, but resulted in competition for pollinators among flowers. No pollen limitation was, however, found in two experimental species. Direct grazing of reproductive organs outweighed indirect effects on plant reproduction through effects on pollination. Reproduction and population structure of P. veris was mainly controlled by seedling establishment, pollen limitation, and direct grazing of fruits. No constant landscape effects were found. Grazed populations had high proportions of seedlings and juveniles due to high recruitment and mortality of adult plants, whereas ungrazed populations had higher proportions of adult plants due to low recruitment. The net effect was similar densities of young plants in grazed and ungrazed populations. Management regimes such as less intense grazing, late summer grazing, or late summer mowing would increase both seed production and establishment, thereby favouring populations of P. veris.