Complexity of Strong Implementability

We consider the question of implementability of a social choice function in a classical setting where the preferences of finitely many selfish individuals with private information have to be aggregated towards a social choice. This is one of the central questions in mechanism design. If the concept of weak implementation is considered, the Revelation Principle states that one can restrict attention to truthful implementations and direct revelation mechanisms, which implies that implementability of a social choice function is easy to check. For the concept of strong implementation, however, the Revelation Principle becomes invalid, and the complexity of deciding whether a given social choice function is strongly implementable has been open so far. In this paper, we show by using methods from polyhedral theory that strong implementability of a social choice function can be decided in polynomial space and that each of the payments needed for strong implementation can always be chosen to be of polynomial encoding length. Moreover, we show that strong implementability of a social choice function involving only a single selfish individual can be decided in polynomial time via linear programming

Automatic speech analysis to early detect functional cognitive decline in elderly population

This study aimed at evaluating whether people with a normal cognitive function can be discriminated from subjects with a mild impairment of cognitive function based on a set of acoustic features derived from spontaneous speech. Voice recordings from 90 Italian subjects (age >65 years; group 1: 47 subjects with MMSE>26; group 2: 43 subjects with 20≤ MMSE ≤26) were collected. Voice samples were processed using a MATLAB-based custom software to derive a broad set of known acoustic features. Linear mixed model analyses were performed to select the features able to significantly distinguish between groups. The selected features (% of unvoiced segments, duration of unvoiced segments, % of voice breaks, speech rate, and duration of syllables), alone or in addition to age and years of education, were used to build a learning-based classifier. The leave-one-out cross validation was used for testing and the classifier accuracy was computed. When the voice features were used alone, an overall classification accuracy of 0.73 was achieved. When age and years of education were additionally used, the overall accuracy increased up to 0.80. These performances were lower than the accuracy of 0.86 found in a recent study. However, in that study the classification was based on several tasks, including more cognitive demanding tasks. Our results are encouraging because acoustic features, derived for the first time only from an ecologic continuous speech task, were able to discriminate people with a normal cognitive function from people with a mild cognitive decline. This study poses the basis for the development of a mobile application performing automatic voice analysis on-the-fly during phone calls, which might potentially support the detection of early signs of functional cognitive decline

Investments in the digital silk road

This chapter discusses opportunities for the new digital economy, a strategically important factor of the economic growth for contributing to the Central Asia Digital Silk Road concept. Focusing on new opportunities for international cooperation, including the development of digital technologies, the chapter also draws attention to the fact that technology advancement causes changes in the economic system which may result in digital inequality. It argues that the O&G industry can become a key driver of growth and development and could potentially boost competitiveness across all sectors. The authors consider a set of public policies in ICT-related sectors in Kazakhstan. These policies are focusing on diversification from the O&G sector, supporting domestic companies and research, encouraging export-oriented projects, and pushing companies to join international initiatives

The Usability of E-learning Platforms in Higher Education: A Systematic Mapping Study

The use of e-learning in higher education has increased significantly in recent years, which has led to several studies being conducted to investigate the usability of the platforms that support it. A variety of different usability evaluation methods and attributes have been used, and it has therefore become important to start reviewing this work in a systematic way to determine how the field has developed in the last 15 years. This paper describes a systematic mapping study that performed searches on five electronic libraries to identify usability issues and methods that have been used to evaluate e-learning platforms. Sixty-one papers were selected and analysed, with the majority of studies using a simple research design reliant on questionnaires. The usability attributes measured were mostly related to effectiveness, satisfaction, efficiency, and perceived ease of use. Furthermore, several research gaps have been identified and recommendations have been made for further work in the area of the usability of online learning

A constant approximation algorithm for the densest k-subgraph problem on chordal graphs

The densest k-subgraph (DkS) problem asks for a k-vertex subgraph of a given graph with the maximum number of edges. The DkS problem is NP-hard even for special graph classes including bipartite, planar, comparability and chordal graphs, while no constant approximation algorithm is known for any of these classes. In this paper we present a 3-approximation algorithm for the class of chordal graphs. The analysis of our algorithm is based on a graph theoretic lemma of independent interest. © 2008 Elsevier B.V. All rights reserved

The densest k-subgraph problem on clique graphs

The Densest k-Subgraph (DkS) problem asks for a k-vertex subgraph of a given graph with the maximum number of edges. The problem is strongly NP-hard, as a generalization of the well known Clique problem and we also know that it does not admit a Polynomial Time Approximation Scheme (PTAS). In this paper we focus on special cases of the problem, with respect to the class of the input graph. Especially, towards the elucidation of the open questions concerning the complexity of the problem for interval graphs as well as its approximability for chordal graphs, we consider graphs having special clique graphs. We present a PTAS for stars of cliques and a dynamic programming algorithm for trees of cliques. © 2007 Springer Science+Business Media, LLC

The densest k-subgraph problem on clique graphs

The Densest k-Subgraph (DkS) problem asks for a k-vertex subgraph of a given graph with the maximum number of edges. The problem is strongly NP-hard, as a generalization of the well known Clique problem and we also know that it does not admit a Polynomial Time Approximation Scheme (PTAS). In this paper we focus on special cases of the problem, with respect to the class of the input graph. Especially, towards the elucidation of the open questions concerning the complexity of the problem for interval graphs as well as its approximability for chordal graphs, we consider graphs having special clique graphs. We present a PTAS for stars of cliques and a dynamic programming algorithm for trees of cliques

An optimum level of nano-selenium supplementation of a broiler diet according to the performance, economical parameters, plasma constituents and immunity

An optimum nano-Se content in a diet of highly productive broilers has not been defined yet. Meanwhile, there are contradictory reports regarding effects of nano-Se on production traits and the etiology of possible positive effects. The aims of the present study were to test the hypothesis that low levels of nano-Se can improve productivity and metabolic functions during a 42-day-long broiler production cycle, to determine an optimum nano-Selenium (nano-Se) concentration of the diet, and finally to explore the etiology of these effects. One-hundred-eighty 1-day-old, male, Ross 308 broiler chicks were used in a completely randomized experiment, where the birds were placed in experimental pens, in three replicate pens of 10 chicks each, making a total of 18 experimental units. They were assigned diets with different nano-Selenium levels. All birds were fed an almost identical diet from 1 until 42 d, different only in the nano-Se content, namely: 1) control (CON) group 0.0 nano-Se, 2) NS1 group 0.1 mg kg-1 dietary nano-Se, 3) NS2 group 0.2 mg kg-1 dietary nano-Se, 4) NS3 group 0.3 mg kg-1 dietary nano-Se, 5) NS4 group 0.4 mg kg-1 dietary nano-Se, 6) NS5 group 0.5 mg kg-1 dietary nano-Se, supplied from 1 to 42 day of life. The significance level was declared at P<0.05. The final bird weight was higher and production cost was lower in NS3 and NS4 groups compared to CON, NS1 and NS5. The weight of an eviscerated carcass was lower in CON group compared to the other groups. The serum blood parameters as well as the weight of organs related with the immune system were not significantly different between groups. Nano-Se supplementation positively affected body weight gain (BWG) and feed conversion ratio (FCR). Higher BWG was achieved owing to better FCR rather than higher feed intake. The supplementation of 0.3-0.4 mg nano-Se kg-1 is the optimum level to be added as a feed additive in broiler diets, increasing animal productivity and diminishing environmental impac

Tsuyuko-hime [picture]

Title taken from the reference source by Nanako Yamada.; Printmaker's seal and signature present.; 880-04 Yamada, Nanako. Mokuhan kuchi-e soran 80.5; Also available in an electronic version via the internet: http://nla.gov.au/nla.pic-vn5197062; 880-05 The print was produced as a kuchie frontispiece for a novel titled Tsuyuko-hime by Ishibashi Ningetsu