Online Project Management for Dynamic e-Collaboration

Today’s collaborative projects demand efficient and productive software application tools for the workplace that will bring remote teams together to get the work done. Dynamic e-collaboration is a necessity for virtual relations and business agreements. It depends on two distinct factors: trust and need. This paper presents a way to manage remote teams using a web application developed with ColMap model of project management in an IT company. The information exposed and shared applications with partners in collaborative projects are based on RBAC. Group collaboration and management software has been proven to successfully manage and coordinate projects.Dynamic E-collaboration, Collaboration Model, Web Application

Min (A)cyclic Feedback Vertex Sets and Min Ones Monotone 3-SAT

In directed graphs, we investigate the problems of finding: 1) a minimum feedback vertex set (also called the Feedback Vertex Set problem, or MFVS), 2) a feedback vertex set inducing an acyclic graph (also called the Vertex 2-Coloring without Monochromatic Cycles problem, or Acyclic FVS) and 3) a minimum feedback vertex set inducing an acyclic graph (Acyclic MFVS). We show that these problems are strongly related to (variants of) Monotone 3-SAT and Monotone NAE 3-SAT, where monotone means that all literals are in positive form. As a consequence, we deduce several NP-completeness results on restricted versions of these problems. In particular, we define the 2-Choice version of an optimization problem to be its restriction where the optimum value is known to be either D or D+1 for some integer D, and the problem is reduced to decide which of D or D+1 is the optimum value. We show that the 2-Choice versions of MFVS, Acyclic MFVS, Min Ones Monotone 3-SAT and Min Ones Monotone NAE 3-SAT are NP-complete. The two latter problems are the variants of Monotone 3-SAT and respectively Monotone NAE 3-SAT requiring that the truth assignment minimize the number of variables set to true. Finally, we propose two classes of directed graphs for which Acyclic FVS is polynomially solvable, namely flow reducible graphs (for which MFVS is already known to be polynomially solvable) and C1P-digraphs (defined by an adjacency matrix with the Consecutive Ones Property)

On the Epistemology of Modal Rationalism: the Main Problems and Their Significance

In this paper, I discuss the main characteristics of the epistemology of modal rationalism by proceeding from the critical investigation of Peacocke’s theory of modality. I build on arguments by Crispin Wright and Sonia Roca-Royes, which are generalised and supplemented by further analysis, in order to show that principle-based accounts have little prospects of succeeding in their task of providing an integrated account of the metaphysics and the epistemology of modality. I argue that it is unlikely that we will able to develop an exhaustive and accurate principle-based account that discriminates objectively between correct and deviant modal knowledge. Even if such an account can be formulated, a non-circular way of justifying its necessity also seems to be out of our reach

Clustering before training large datasets - Case study: K-SVD

Training and using overcomplete dictionaries has been the subject of many developments in the area of signal processing and sparse representations. The main idea is to train a dictionary that is able to achieve good sparse representations of the items contained in a given dataset. The most popular approach is the K-SVD algorithm and in this paper we study its application to large datasets. The main interest is to speedup the training procedure while keeping the representation errors close to some specific values. This goal is reached by using a clustering procedure, called here T-mindot, which reduces the size of the dataset but keeps the most representative data items and a measure of their importance. Experimental simulations compare the running times and representation errors of the training method with and without the clustering procedure and they clearly show how effective T-mindot is

Agricultural Policy Influence Upon the Economic Behaviour of Rural Households

The deep transformations brought about by the progressive and steady commitment of Romanian economy to the market economy have determined, among others, the modification of the role and status of rural household in the economic activity. Rural household changed from a simple participant, constrained to act in a certain way under a centralised, equalising and levelling system during the communist period, to a participant that carries out its activity in a competing environment in which initiative, creativity and efficiency are defining elements. Based on field surveys conducted at national level, the present paper intends to identify the evolution of economic behaviours specific to rural households under the influence of agricultural policy measures in the period 1997-2000. The conclusions of this study reveal that in this period, most of rural households operated under a subsistence system, according to an economic rationality in which market economy mechanism are lacking. However, the economic picture is far from being a homogeneous one: the emergence of a nucleus of agricultural entrepreneurs, i.e. those who assume the risk of shifting from subsistence to competitive agriculture, those who are trying to turn the peasant household into a farm managed on the capitalist principles, has induced new economic behaviours in the rural communities.rural household, economic behaviour, agricultural policy, Romania, Consumer/Household Economics,

Block Orthonormal Overcomplete Dictionary Learning

In the field of sparse representations, the overcomplete dictionary learning problem is of crucial importance and has a growing application pool where it is used. In this paper we present an iterative dictionary learning algorithm based on the singular value decomposition that efficiently construct unions of orthonormal bases. The important innovation described in this paper, that affects positively the running time of the learning procedures, is the way in which the sparse representations are computed - data are reconstructed in a single orthonormal base, avoiding slow sparse approximation algorithms - how the bases in the union are used and updated individually and how the union itself is expanded by looking at the worst reconstructed data items. The numerical experiments show conclusively the speedup induced by our method when compared to previous works, for the same target representation error

Agricultural Land Fragmentation and Land Consolidation Rationality

Adopted about one year after the 1989 Revolution, Land Law (Law 18/1991) represented the starting point of land reform in Romania. As a result of this law implementation, at the beginning of the year 2000 the private sector owned 84% of total agricultural land: 82% of arable land, 74% of land under vineyards, 67% of land under orchards and 87% of land under meadows and pastures. Besides the benefic social and economic effects, the mutations produced represent a distortion source in the rural area, determining the following, among others: a) crisis of ownership relations - a main aspect of this being the confusion concerning the ownership rights. The prolongation of clearing up these rights represents a major obstacle to a good operation of land market, to agricultural land consolidation implicitly; b) managerial crisis, manifested by the lack of competitive behaviour, which gives an increased importance to the production function, to the detriment of commercial function; this results in the increased share of small-sized subsistence farms (households), lack of strategic orientations, etc; c) land market crisis - occurred in the context of the lack of legal and institutional framework concerning the land market operation (credits in advantageous conditions for buying land through the banking system or by establishing specialised banks, solving up the problems in connection to using land as collateral for obtaining credits, mortgage credit stimulation); d) crisis of agricultural economic efficiency - mainly generated by land property excessive fragmentation, large area (about 55%) owned by old persons or by persons not having their domicile in the rural area, lack of main production factors combination, limited circulation of land capital, lack of an adequate legal and institutional framework, etc. An analysis of the concrete, social and economic situation of land fragmentation and of agricultural land consolidation opportunity was conducted in the commune Balaciu; this commune is located in the plain area, with a population of 3540 inhabitants and a total area of 8462 ha. In order to identify the rural social actors which can favour land consolidation by their structure, behaviour and functionality, the following typology of rural households has been used as methodology: agricultural households (consisting of persons working only in agriculture); pluriactive households (consisting of persons involved in both agricultural and non-agricultural activities); non-active households (consisting of non-active persons); non-agricultural households (only persons working in other non-agricultural activities). The survey revealed that the main entities which can become the social actors of rural/agricultural modernisation, of land consolidation implicitly are the pluriactive and non-agricultural households. In order to consolidate the agricultural land, there is an obvious and imperative need to conceive a well articulated and coherent framework of support measures, understood and treated as a complex of economic, social, legal and technical measures, aiming at rural community development.Farm Management, Land Economics/Use,

Speculative Approximations for Terascale Analytics

Model calibration is a major challenge faced by the plethora of statistical analytics packages that are increasingly used in Big Data applications. Identifying the optimal model parameters is a time-consuming process that has to be executed from scratch for every dataset/model combination even by experienced data scientists. We argue that the incapacity to evaluate multiple parameter configurations simultaneously and the lack of support to quickly identify sub-optimal configurations are the principal causes. In this paper, we develop two database-inspired techniques for efficient model calibration. Speculative parameter testing applies advanced parallel multi-query processing methods to evaluate several configurations concurrently. The number of configurations is determined adaptively at runtime, while the configurations themselves are extracted from a distribution that is continuously learned following a Bayesian process. Online aggregation is applied to identify sub-optimal configurations early in the processing by incrementally sampling the training dataset and estimating the objective function corresponding to each configuration. We design concurrent online aggregation estimators and define halting conditions to accurately and timely stop the execution. We apply the proposed techniques to distributed gradient descent optimization -- batch and incremental -- for support vector machines and logistic regression models. We implement the resulting solutions in GLADE PF-OLA -- a state-of-the-art Big Data analytics system -- and evaluate their performance over terascale-size synthetic and real datasets. The results confirm that as many as 32 configurations can be evaluated concurrently almost as fast as one, while sub-optimal configurations are detected accurately in as little as a $1/20^{\text{th}}$ fraction of the time

A Survey on Array Storage, Query Languages, and Systems

Since scientific investigation is one of the most important providers of massive amounts of ordered data, there is a renewed interest in array data processing in the context of Big Data. To the best of our knowledge, a unified resource that summarizes and analyzes array processing research over its long existence is currently missing. In this survey, we provide a guide for past, present, and future research in array processing. The survey is organized along three main topics. Array storage discusses all the aspects related to array partitioning into chunks. The identification of a reduced set of array operators to form the foundation for an array query language is analyzed across multiple such proposals. Lastly, we survey real systems for array processing. The result is a thorough survey on array data storage and processing that should be consulted by anyone interested in this research topic, independent of experience level. The survey is not complete though. We greatly appreciate pointers towards any work we might have forgotten to mention.Comment: 44 page