On the Static Analysis for SPARQL Queries Using Modal Logic

International audienceStatic analysis is a core task in query optimization and knowledge base verification. We study static analysis techniques for SPARQL, the standard language for querying Semantic Web data. Specifically , we investigate the query containment problem and query-update independence analysis. We are interested in developing techniques through reductions to the validity problem in logic

Survivors’ Perspectives of Organizational Downsizing on Knowledge Sharing in a Downsized Environment

Organizational workforce reductions can negatively affect a company’s ability to preserve its knowledge base. The problem researched in this study was the perceived effect of downsizing on knowledge sharing among surviving employees. The purpose of this study was to determine the perceived effect of downsizing on knowledge sharing. Survivors’ knowledge sharing behavior was examined in relation to (a) survivor syndrome, (b) attitude towards knowledge sharing, and (c) perceived loss of knowledge power. A quantitative correlation research design was used to investigate the relationship between downsizing and knowledge sharing. A web-based survey was used to collect data. The convenience sample consisted of 37 management employees in the Texas region of a management consultant organization. Three sets of variables were examined: (a) survivor syndrome and actual knowledge sharing behavior, (b) survivors’ attitudes toward knowledge sharing and actual knowledge sharing behavior, and (c) perceived loss of knowledge power and actual knowledge sharing behavior. Findings from a Spearman rank order correlation revealed a statistically significant positive correlation between perceived loss of knowledge power and actual knowledge sharing behavior. Understanding survivors’ reactions can assist with planning for future reductions, and lead to the development of training programs to counter the challenges

Survivors’ Perspectives of Organizational Downsizing on Knowledge Sharing in a Downsized Environment

Organizational workforce reductions can negatively affect a company’s ability to preserve its knowledge base. The problem researched in this study was the perceived effect of downsizing on knowledge sharing among surviving employees. The purpose of this study was to determine the perceived effect of downsizing on knowledge sharing. Survivors’ knowledge sharing behavior was examined in relation to (a) survivor syndrome, (b) attitude towards knowledge sharing, and (c) perceived loss of knowledge power. A quantitative correlation research design was used to investigate the relationship between downsizing and knowledge sharing. A web-based survey was used to collect data. The convenience sample consisted of 37 management employees in the Texas region of a management consultant organization. Three sets of variables were examined: (a) survivor syndrome and actual knowledge sharing behavior, (b) survivors’ attitudes toward knowledge sharing and actual knowledge sharing behavior, and (c) perceived loss of knowledge power and actual knowledge sharing behavior. Findings from a Spearman rank order correlation revealed a statistically significant positive correlation between perceived loss of knowledge power and actual knowledge sharing behavior. Understanding survivors’ reactions can assist with planning for future reductions, and lead to the development of training programs to counter the challenges

On Basing Auxiliary-Input Cryptography on NP-Hardness via Nonadaptive Black-Box Reductions

Constructing one-way functions based on NP-hardness is a central challenge in theoretical computer science. Unfortunately, Akavia et al. [Akavia et al., 2006] presented strong evidence that a nonadaptive black-box (BB) reduction is insufficient to solve this challenge. However, should we give up such a central proof technique even for an intermediate step? In this paper, we turn our eyes from standard cryptographic primitives to weaker cryptographic primitives allowed to take auxiliary-input and continue to explore the capability of nonadaptive BB reductions to base auxiliary-input primitives on NP-hardness. Specifically, we prove the followings: - if we base an auxiliary-input pseudorandom generator (AIPRG) on NP-hardness via a nonadaptive BB reduction, then the polynomial hierarchy collapses; - if we base an auxiliary-input one-way function (AIOWF) or auxiliary-input hitting set generator (AIHSG) on NP-hardness via a nonadaptive BB reduction, then an (i.o.-)one-way function also exists based on NP-hardness (via an adaptive BB reduction). These theorems extend our knowledge on nonadaptive BB reductions out of the current worst-to-average framework. The first result provides new evidence that nonadaptive BB reductions are insufficient to base AIPRG on NP-hardness. The second result also yields a weaker but still surprising consequence of nonadaptive BB reductions, i.e., a one-way function based on NP-hardness. In fact, the second result is interpreted in the following two opposite ways. Pessimistically, it shows that basing AIOWF or AIHSG on NP-hardness via nonadaptive BB reductions is harder than constructing a one-way function based on NP-hardness, which can be regarded as a negative result. Note that AIHSG is a weak primitive implied even by the hardness of learning; thus, this pessimistic view provides conceptually stronger limitations than the currently known limitations on nonadaptive BB reductions. Optimistically, it offers a new hope: breakthrough construction of auxiliary-input primitives might also provide construction standard cryptographic primitives. This optimistic view enhances the significance of further investigation on constructing auxiliary-input or other intermediate cryptographic primitives instead of standard cryptographic primitives

The future of crystalline silicon technology in the US Department of Energy program

Two basic findings were presented in the outlined report. The first is that silicon has a very high potential efficiency, demonstrated improvement in reliability and a significant potential for cost reductions. The second is that the photovoltaic technology development process is highly uncertain, but crystalline silicon technology has a substantial knowledge base to draw from, improving its chances of success. Several issues to be addressed are outlined

The workforce retention dividend - valuing knowledge and skills in the public sector workforce

This report demonstrates the hidden costs of public sector job losses.  Key findings: Rapid loss of public sector workers, especially those with more experience and skill, will result in the loss of corporate knowledge and hinder the transfer of skills within the South Australian public service. This loss represents a considerable value which needs to be taken into account in public sector workforce planning. Over the next five years an accelerating retirement rate of public servants will coincide with the significant expansion of the resources sector. Combined these forces will result in tightening of the South Australian labour market. In this environment it will be more difficult to attract and retain experienced workers in the public sector. Loss of knowledge and skill in this context is particularly problematic. It may harm the ability of the State Government to deliver its programs effectively and efficiently. It is possible to estimate the approximate average value (investment) of a public service worker over his or her tenure in order to understand the implications of the State Governments public sector workforce employment reductions strategy (1600 FTEs or approximately 1913 persons on an FTE to person ratio). The total cost of hiring 1913 persons is approximately $38,259,200. The average total expenditure on training for them during their tenure is$25,308,460. Therefore, the total recruitment and training expenditure on average for the 1600 FTE public sector workforce reductions is around $63,567,660. The State Government needs to develop a better understanding of the implications of staff losses for the knowledge and skill base of the public service as a central element of public sector workforce planning. The central challenge to be faced by policymakers is the potential loss of a large number of experienced and skilled public sector workers over a relatively short period of time and the growing difficulty of sourcing suitable replacements in a tighter labour market. There is an urgent need to develop a multi-faceted approach to attraction and retention that addresses a range of drivers and barriers. Some progress is being made in this respect. The Treasurers announcement, in the 2011-12 State Budget of the introduction a new Retention Provision represents a constructive contribution to this and should be implemented universally across the public sector. There will be particular challenges associated with attraction and retention of public servants in regional South Australia where employment demand generated by mining projects has the potential to starve the public sector of various occupational skills. Related identifier: ISBN: 978-0-9871950-4-

The effect of regional differences on the performance of software firms in the Netherlands

In this paper, we concentrate on how evolutionary economics contributes to a better understanding of the spatial evolution of newly emerging industries. Inspired by evolutionary thinking, four types of explanations are discussed and tested in an empirical analysis of the spatial pattern of the software sector in the Netherlands. Traditionally, agglomeration economies provide an explanation for the spatial concentration of an industry. Firms located in a cluster of similar or related sectors benefit from cost reductions, due to lower transportation costs, a thick labour market, specialised suppliers and information spillovers. An evolutionary approach on agglomeration economies provides an alternative view. It focuses explicit attention on knowledge spillovers as a vehicle of local diffusion of organizational routines or competences from one firm to the other. Such transfers of (tacit) knowledge are facilitated by spatial proximity of firms and a common knowledge base. In addition, an evolutionary approach takes a dynamic perspective on the role of agglomeration economies. During the initial stage of development of a new industry, the surrounding environment is still directed to routines and competences related to existing industries. When the new industry concentrates in a particular area to a considerable degree, a supportive environment (specialized knowledge, labour with specific skills) may gradually come into being, and localization economies may arise. Other evolutionary mechanisms may also provide an explanation for the spatial formation of new industries. We distinguish another three of them. First of all, transfer of knowledge and successful routines between firms in an emerging industry may occur through spin-off dynamics. Secondly, (social) networks may function as effective channels of knowledge diffusion and interactive learning, because they can provide a common knowledge base and mutual understanding and trust. Thirdly, firms in new industries with organizational capabilities that can deal effectively with the lack of required resources (such as knowledge, skills and capital) may become dominant, due to selection and imitation. Based on cross-sectional data gathered among 265 software firms in the Netherlands in 2003, we have tested which factors have influenced the innovative productivity of these firms. Using regression techniques, the outcomes suggest that spin-offs and firms with organizational capabilities perform better, while networks relations do not seem to affect the performance of software firms. Geography matters as well: software firms located in a region with a labour market with more ICT-skills show a higher innovative productivity. Keywords: evolutionary economics, industrial location, evolution of industries, software sector, agglomeration economies, organizational capabilities, spin-off, networks

The effect of regional differences on the performance of software firms in the Netherlands

In this paper, we concentrate on how evolutionary economics contributes to a better understanding of the spatial evolution of newly emerging industries. Inspired by evolutionary thinking, four types of explanations are discussed and tested in an empirical analysis of the spatial pattern of the software sector in the Netherlands. Traditionally, agglomeration economies provide an explanation for the spatial concentration of an industry. Firms located in a cluster of similar or related sectors benefit from cost reductions, due to lower transportation costs, a thick labour market, specialised suppliers and information spillovers. An evolutionary approach on agglomeration economies provides an alternative view. It focuses explicit attention on knowledge spillovers as a vehicle of local diffusion of organizational routines or competences from one firm to the other. Such transfers of (tacit) knowledge are facilitated by spatial proximity of firms and a common knowledge base. In addition, an evolutionary approach takes a dynamic perspective on the role of agglomeration economies. During the initial stage of development of a new industry, the surrounding environment is still directed to routines and competences related to existing industries. When the new industry concentrates in a particular area to a considerable degree, a supportive environment (specialized knowledge, labour with specific skills) may gradually come into being, and localization economies may arise. Other evolutionary mechanisms may also provide an explanation for the spatial formation of new industries. We distinguish another three of them. First of all, transfer of knowledge and successful routines between firms in an emerging industry may occur through spin-off dynamics. Secondly, (social) networks may function as effective channels of knowledge diffusion and interactive learning, because they can provide a common knowledge base and mutual understanding and trust. Thirdly, firms in new industries with organizational capabilities that can deal effectively with the lack of required resources (such as knowledge, skills and capital) may become dominant, due to selection and imitation. Based on cross-sectional data gathered among 265 software firms in the Netherlands in 2003, we have tested which factors have influenced the innovative productivity of these firms. Using regression techniques, the outcomes suggest that spin-offs and firms with organizational capabilities perform better, while networks relations do not seem to affect the performance of software firms. Geography matters as well: software firms located in a region with a labour market with more ICT-skills show a higher innovative productivity.Evolutionary economics, industrial location, evolution of industries, software sector, agglomeration economies, organizational capabilities, spin-off, networks