Miracle-dz/UniFAR-FTUs huggingface dataset:
An Approach for Improving Performance of Back off Algorithm

In the field of wireless networks one of the arduous assignments is to design an efficient MAC scheme. The key aspect in the design of any contention-based medium access control (MAC) protocol is the mechanism to measure and resolve simultaneous contention because of dynamic topology IEEE 802.11 suffers from high collision rate which affects the performance of WLAN to overcome this many back off schemes have been proposed. IEEE 802.11, which provides technical specifications for wireless interfaces, uses DCF (Distributed Coordinated Function) as the MAC scheme. DCF uses BEB (Binary Exponential Back off) algorithm for Contention resolution among the stations. it performed well at the beginning but researchers found that DCF’s main limitation is as the number of stations increases, number of collisions also increases to a great extent. Increased collision rate has affected other performance metrics such as decreased throughput. This has led to the DCF’s performance degradation hence a back off scheme is needed to improve the performance of the network. it is found that to improve the performance of a MAC protocol, the back off algorithm play an important role. Hence, we have modified a BEB algorithm suitable for a MANET. The entire enhancement done to this algorithm is studied in depth. In this paper we discuss about the Sensing Back off algorithm which has been integrated with MAC protocol this algorithm greatly reduces the end to end delay and collision rate the important factor here is the proposed algorithm simulated at different data rate.
Extragalactic Background Light: new constraints from the study of the photon-photon absorption on blazar spectra

The study of the Extragalactic Background Light (EBL) is crucial to understand many astrophysical problems (as the formation of first stars, the evolution of galaxies and the role of dust emission). At present, one of the most powerful ways to put constraints on EBL is represented by the study of the photon-photon absorption on gamma-ray spectra of TeV blazars. Adopting this method, we found that, if the only contribution to the optical and Near Infrared (NIR) background is given by galaxies, the spectrum of the blazar H1426+428 cannot be fitted. To reproduce the observational data of H1426+428 a Near Infrared excess with respect to galaxy counts is required, with amplitude consistent with both the Matsumoto et al. (2000) data with Kelsall's model of zodiacal light (ZL) subtraction and the DIRBE data with Wright's model of ZL subtraction. The derived constraints on the optical EBL are weaker, because the experimental errors on blazar data are still bigger than the differences among various optical EBL models. In the mid-infrared the SPITZER measurement at 24 micron provides the best fit of the blazar spectrum.
From Pictures to Words: Generating Locative Descriptions of Objects in an Image

In this paper we describe a system that integrates image processing and natural language processing for tasks that involve communicating visual information. The system determines information about the spatial relationship of objects in images and conveys it in the form of an English sentence. We are exploring the applicability of this system to two tasks: landmark navigation and the generation of descriptions of abnormal densities in radiographs. Our previous work described a computational model of preposition semantics and a method for handling some of the ambiguities associated with natural language. Here we concentrate on generating optimal locative expressions for object pairs. In describing the system we will explain the method-ologies it employs to achieve its goals. We will illustrate the system's use of these methodologies through several examples for each task.
A High Precision CMOS Current-mode Band-gap Voltage Reference

A new high precision CMOS current-mode band-gap voltage reference which takes advantage of the high-order curvature-compensated technique and the enhancement pre-regulator technique is proposed. Based on the 1 st 0.35mum standard mixed-signal CMOS process technology, the circuit achieves a much low temperature coefficient of 3.68ppm/degC over the temperature range of -40 degC to +150degC with 1.00V output reference voltage and a high PSRR over a broad frequency range. The PSRR is -125.4dB at 100Hz and remains -59.2dB at 100MHz. Using push-pull output stage instead of the bias circuits, the power dissipation is only about 50muW
Combining Deterministic and Probabilistic Methods to Produce Gridded Climatologies

There are nearly 8,000 sites in the United States for which detailed climatologies of various atmospheric variables have been produced. However, spatial interpolation of these point climatologies via traditional techniques (IDW, kriging, etc.) is often not accurate, especially in mountainous regions, coastal zones, or data sparse areas. This paper discusses NCDC's preliminary efforts to combine deterministic and probabilistic methods to produce improved gridded climatologies. Two methods to combine multiple linear regression information with deterministic climatologies produced by the Advanced Climate Modeling and Environmental Simulation (ACMES) modeling system are described. GIS is used to visualize intermediate and final grids during the development of these techniques.
Forced displacement : why rights matter

Introduction K.Grabska and L.Mehta Protection and Durable Solutions: Regimes for Development and Conflict-Induced Internally Displaced and Resettled Populations R.Muggah Rights and Development-Induced Displacement: Risk Management or Social Protection? B.Morvaridi Brothers or Poor Cousins? Rights, Policies and the Wellbeing of Refugees in Egypt K.Grabska Refugees or Foreigners? The Case of Palestinians in Lebanon J.Suleiman Access to Economic and Social Rights in First Countries of Asylum and Repatriation: A Case Study of Eritrean Refugees in Sudan G.Kibreab Rights and Decisions to Return: Internally Displaced Persons in Post-war Sudan M.Assal Rights, Needs and Responsibility: Challenges to Rights-Based Advocacy for Refugees' Health and Education in Lebanon S.Trad and M.Kagan Indigenous Peoples, Displacement Through 'Development' and Rights Violations: The Case of the Orang Asli of Peninsular Malaysia C.Yong Ooi Lin Why are Human Rights Violated with Impunity? Forced Displacement in India's Narmada Valley L.Mehta Protests Against UNHCR to Achieve Rights: Some Reflections B.Harrell-Bond Conclusion K.Grabska and L.Mehta
Large scale characterisation of YouTube requests in a cellular network

Traffic from wireless and mobile devices is expected to soon exceed traffic from fixed devices. Understanding the behaviour of users on mobile devices is important in order to improve the offered services and the provision of the underlying network. Globally, more than 60% of consumer Internet traffic is estimated to be video traffic, and the most popular video website, YouTube, estimates that mobile access makes up nearly 40% of the global watch time. This paper presents the first work to study the characteristics of YouTube user requests on a nationwide cellular network. This study is based on the analysis of a large dataset generated by 3 million users and collected by a major telecom operator. We show for instance that 20% of the users generate 78% of the requests, and that over 80% of the requests target only 20% of the distinct videos accessed during the data collection period. Our results provide a comprehensive insight into the way people use YouTube on mobile devices, and show a very high potential for video cacheability on the cellular network.
Delay QoS provisioning in cognitive radio systems using adaptive modulation

The spectrum of licensees can be shared by some secondary users in cognitive radio systems. However, the secondary transmitters are limited by an interference threshold constraint which is imposed by the primary receivers in order to ensure primary users' reliable communication. In this paper, we assume that a number of secondary transmitters are trying to transmit their data to some secondary receivers in the presence of primary transmitters and receivers and, therefore, their inflicted interference at the primary receivers should be less than a specific threshold. We consider the delay quality of service and use the idea of effective capacity to guarantee a desired delay quality of service for every secondary link. By maximizing the sum of effective capacities of the secondary links we propose adaptive modulation schemes to support the desired quality of service. Two different optimal (continuous) and suboptimal (discrete) schemes are proposed and the rate and power allocation is obtained for each scheme. The performance of these two schemes is also compared.
Perceived Individual Collaboration Know-How Development Through IT-Enabled Contextualization : Evidence from Distributed Teams

In today’s global market environment, enterprises are increasingly turning to use of distributed teams to leverage their resources and address diverse markets. Individual members of such structurally diverse distributed teams need to develop their collaboration know-how to work effectively with others on their team. The lack of face-to-face cues creates challenges in developing the collaboration knowhow, challenges that can be overcome by communicating not just content, but also context. We derive a theoretical model from Te’eni’s (2001) cognitive-affective model of communication to elaborate how IT can support an individual’s communication of context in order to develop collaboration know-how. 263 individuals working in structurally diverse distributed teams using a variety of virtual workspace technologies to support their communication needs were surveyed to test the model. Results indicate that when individuals perceive their task as non-routine, there is a positive relationship between an individual’s perceived degree of IT support for communicating context information and their collaboration know-how development. However, when individuals perceived their task as routine, partial IT support for contextualization was associated with lower levels of collaboration know-how development. This finding is attributed to individuals’ misunderstanding of the conveyed context or struggling to utilize the context conveyed with partial IT support, making a routine task more prone to misunderstanding, leaving the user worse than if she had no IT support for contextualization. We end the paper by drawing theoretical and practical implications based on these findings.
On the scattering theory of the Laplacian with a periodic boundary condition. II. Additional channels of scattering

We study spectral and scattering properties of the Lapla- cian H (¾) = i¢ in L2(R 2 ) corresponding to the boundary condition @u @o +¾u = 0 for a wide class of periodic functions ¾. For non-negative ¾ we prove that H (¾) is unitarily equivalent to the Neumann Lapla- cian H (0) . In general, there appear additional channels of scattering
Frequency, Collocation, and Statistical Modeling of Lexical Items: A Case Study of Temporal Expressions in Two Conversational Corpora

This study examines how different dimensions of corpus frequency data may affect the outcome of statistical modeling of lexical items. Our analysis mainly focuses on a recently constructed elderly speaker corpus that is used to reveal patterns of aging people's language use. A conversational corpus contributed by speakers in their 20s serves as complementary material. The target words examined are temporal expressions, which might reveal how the speech produced by the elderly is organized. We conduct divisive hierarchical clustering analyses based on two different dimensions of corporal data, namely raw frequency distribution and collocation-based vectors. When different dimensions of data were used as the input, results showed that the target terms were clustered in different ways. Analyses based on frequency distributions and collocational patterns are distinct from each other. Specifically, statistically-based collocational analysis generally produces more distinct clustering results that differentiate temporal terms more delicately than do the ones based on raw frequency.
PAPR Reduction Techniques Comparison inOFDM System

In recent years, multimedia based application which requires the technology that supports high speed data transmission is growing rapidly. To achieve this high speed communication orthogonal frequency division multiplexing (OFDM) is most widely used technology. OFDM system makes the use of orthogonal subcarriers for data transmission with efficient usage of available bandwidth. However as number of subcarriers goes on increasing, Peak to average power ratio (PAPR) of OFDM signal also increasing. This high PAPR causes significant distortions when passed through non-linear amplifier. A number of promising techniques have been proposed & implemented to reduce PAPR of OFDM signal with expense of transmitted signal power, Bit error rate (BER), complexity etc. In this paper, amplitude clipping and filtering (ACF), Iterative clipping and filtering (ICF) and interleaved OFDM techniques are implemented for PAPR reduction of OFDM signal at transmitter. Comparison of these PAPR reduction techniques is done based PAPR and BER performance of the system.
Facilitators for e-Government Development: An Application of the Technology-Organization- Environment Framework

There are relatively few empirical studies that analyze e-Government development from a global perspective. Using secondary data from 115 countries and the Technology-Organization-Environment (TOE) as the guiding theoretical lens, we examine the facilitators for e-Government development. Our research highlights the importance of national technological and organizational (human capital) contexts for e-Government development. Our results also show that national environment (institutional and macro-economic) is not a significant facilitator for e-Government development. Further post hoc analysis reveals the anomalous significant relationship of public institutions with e-Government development in the negative direction. Through this research, we make some important contributions and implications for researchers, practitioners and policy makers.
AUTOMATIC RECTIFICATION OF LONG IMAGE SEQUENCES

This paper addresses the problem of automatically computing homographies between successive frames in image sequences and compensating for the panning, tilting and zooming of the cameras. A homography is a projective mapping between two image planes and describes the transformation created by a fixed camera as it pans, tilts, rotates, and zooms around its optical centre. Our algorithm achieves improved robustness for large motions by combining elements of two previous approaches: it first computes the local displacements of image features using the KanadeLucas-Tomasi (KLT) tracker and determines local matches. The majority of these features are selected by RANSAC and give the initial estimate of the homography. Our modelbased correction system then compensates for remaining projection errors in the image to rink mapping. The system is demonstrated on a digitized sequence of an NHL hockey game, and it is capable of analyzing long sequences of consecutive frames from broadcast video by mapping them into the rink coordinates.
Multi-tenant web application framework architecture pattern

Multi-tenancy is a key to successful and sustainable cloud-based systems. Creating a web application framework for multiple tenants from scratch is challenging. To create an extensible, stable and robust multi-tenant web application framework developers have to understand how a web application framework is structured and how a web request is handled for each user of a specific tenant. This knowledge often takes software architects and developers a lot of effort to obtain. In this paper, we present a novel object-oriented architecture pattern for developing multi-tenant web application frameworks in which maximum reuse and modularity can be achieved and application concerns can be separated. We evaluate the modularity, the extensibility, the reusability, the maintainability and the efficiency of our pattern by qualitative analysis based on well-known patterns used in our pattern. We validate the applicability, the correctness, the security and the performance of our pattern by testing real world systems that were built using our pattern. We believe that our pattern would reduce time and cost when developing multi-tenancy systems as well as understanding, evaluating and modifying existing web application frameworks.
Selecting Domain-Specific Concepts for Question Generation With Lightly-Supervised Methods

In this paper we propose content selection methods for question generation (QG) which exploit domain knowledge. Traditionally, QG systems apply syntactical transformation on individual sentences to generate open domain questions. We hypothesize that a QG sys-tem informed by domain knowledge can ask more important questions. To this end, we propose two lightly-supervised methods to select salient target concepts for QG based on domain knowledge collected from a corpus. One method selects important semantic roles with bootstrapping and the other selects important semantic relations with Open Information Extraction (OpenIE). We demonstrate the effectiveness of the two proposed methods on heterogeneous corpora in the business domain. This work exploits domain knowledge in QG task and provides a promising paradigm to generate domain-speciﬁc questions.
Hadoop energy consumption reduction with hybrid HDFS

Apache Hadoop has evolved significantly over the last years, with more than 60 releases bringing new features. By implementing the MapReduce programming paradigm and leveraging HDFS, its distributed file system, Hadoop has become a reliable and fault tolerant middleware for parallel and distributed computing over large datasets. Nevertheless, Hadoop may struggle under certain workloads, resulting in poor performance and high energy consumption. Users increasingly demand that high performance computing solutions address sustainability and limit energy consumption. In this paper, we introduce HDFSH, a hybrid storage mechanism for HDFS, which uses a combination of Hard Disks and Solid-State Disks to achieve higher performance while saving power in Hadoop computations. HDFSH brings to the middleware the best from HDs (affordable cost per GB and high storage capacity) and SSDs (high throughput and low energy consumption) in a configurable fashion, using dedicated storage zones for each storage device type. We implemented our mechanism as a block placement policy for HDFS, and assessed it over six recent releases of Hadoop with different architectural properties. Results indicate that our approach increases overall job performance while decreasing the energy consumption under most hybrid configurations evaluated. Our results also showed that, in many cases, storing only part of the data in SSDs results in significant energy savings and execution speedups.
Projected Gradient Flows for BV/Level Set Relaxation

This paper introduces a new level set method based on projected gradient flows for problems that can be solved by a recently introduced relaxation approach. For the class of problems the relaxation is exact, it can be shown that the solution of the flow converges to a solution of the relaxed problem for large time, and the level sets of the limit are solutions of the original problem. We introduce a simple computational scheme based on explicit time discretization and apply the method to imaging examples. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Salivary exoglycosidases as markers of alcohol dependence.

BACKGROUND Some salivary markers of alcohol abuse/dependence have been proposed so far: aminotransferases, gamma-glutamyltransferase, ethanol, ethyl glucuronide, ethyl sulfate, sialic acid, β-hexosaminidase A, oral peroxidase, methanol, diethylene/ethylene glycol, α-amylase, clusterin, haptoglobin, heavy/light chains of immunoglobulins and transferrin. AIM To investigate the effect of chronic alcohol drinking and smoking on the activity (pKat/ml) and output (pKat/min) of salivary lysosomal exoglycosidases: α-fucosidase (FUC), α-mannosidase (MAN), β-galactosidase (GAL), and β-glucuronidase (GLU), and their applicability as markers of alcohol dependence. METHODS The activity of FUC, MAN, GAL and GLU was measured colorimetrically in the saliva of healthy social drinkers, alcohol-dependent non-smokers and alcohol-dependent smokers. RESULTS We observed an increased salivary activity of FUC, GAL, GLU and MAN, as well as an increased output of GAL and GLU, in comparison with controls. The highest increase in the activity/output was found in salivary GLU and MAN (GLU, even 7- to 18-fold), and the least in GAL. We found an excellent sensitivity and specificity and a high accuracy (measured by the area under the ROC curve) for salivary FUC, GLU and MAN activities. The salivary GLU activity positively correlated with the number of days of last alcohol intoxication. Salivary activity of FUC, GAL and MAN, but not GLU, positively correlated with the periodontal parameters such as gingival index and papilla bleeding index. CONCLUSIONS Although we found an excellent sensitivity and specificity as well as a high accuracy for the salivary activity of FUC, GLU and MAN, the GLU activity seems to be mostly applicable as a marker of chronic alcohol drinking (alcohol dependence).
Varadhan's formula, conditioned diffusions, and local volatilities

Motivated by marginals-mimicking results for It\^o processes via SDEs and by their applications to volatility modeling in finance, we discuss the weak convergence of the law of a hypoelliptic diffusions conditioned to belong to a target affine subspace at final time, namely $\mathcal{L}(Z_t|Y_t = y)$ if $X_{\cdot}=(Y_\cdot,Z_{\cdot})$. To do so, we revisit Varadhan-type estimates in a small-noise regime (as opposed to small-time), studying the density of the lower-dimensional component $Y$. The application to stochastic volatility models include the small-time and, for certain models, the large-strike asymptotics of the Gyongy-Dupire's local volatility function. The final product are asymptotic formulae that can (i) motivate parameterizations of the local volatility surface and (ii) be used to extrapolate local volatilities in a given model.
An improved edge detector based on the Laplacian operator

In this paper, we propose an improved edge detection method based on the Laplacian operator. The improved edge detector is constructed by combining the optimal criteria for zero-crossing based edge detector and the edge-matching model for Laplacian operator-based edge detector. In order to extract the edges objectively, an unsupervised thresholding technique is introduced. Finally, the validity of the new edge detector is shown by some comparison experiments.