What to consider for applying backfilling on non-dedicated environments

The resource utilization level in open laboratories of several universities has been shown to be very low. Our aim is to take advantage of those idle resources for parallel computation without disturbing the local load. In order to provide a system that lets us execute parallel applications in such a non-dedicated cluster, we use an integral scheduling system that considers both Space and Time sharing concerns. For dealing with the Time Sharing (TS) aspect, we use a technique based on the communication-driven coscheduling principle. This kind of TS system has some implications on the Space Sharing (SS) system, that force us to modify the way job scheduling is traditionally done. In this paper, we analyze the relation between the TS and the SS systems in a non-dedicated cluster. As a consequence of this analysis, we propose a new technique, termed 3DBackfilling. This proposal implements the well known SS technique of backfilling, but applied to an environment with a MultiProgramming Level (MPL) of the parallel applications that is greater than one. Besides, 3DBackfilling considers the requirements of the local workload running on each node. Our proposal was evaluated in a PVM/MPI Linux cluster, and it was compared with several more traditional SS policies applied to non-dedicated environments.

CISNE-P: a global scheduling oriented to NOW environments

In this work, we present an integral scheduling system for non-dedicated clusters, termed CISNE-P, which ensures the performance required by the local applications, while simultaneously allocating cluster resources to parallel jobs. Our approach solves the problem efficiently by using a social contract technique. This kind of technique is based on reserving computational resources, preserving a predetermined response time to local users. CISNE-P is a middleware which includes both a previously developed space-sharing job scheduler and a dynamic coscheduling system, a time sharing scheduling component. The experimentation performed in a Linux cluster shows that these two scheduler components are complementary and a good coordination improves global performance significantly. We also compare two different CISNE-P implementations: one developed inside the kernel, and the other entirely implemented in the user space.

Post-Ottoman Coexistence : Sharing Space in the Shadow of Conflict /

"Post-Ottoman Coexistence", interrogates ways of living together and asks what practices enabled centuries of cooperation and sharing, as well as how and when such sharing was disrupted. This title was made Open Access by libraries from around the world through Knowledge Unlatched.

Public Participation geographic information systems in developing countries: lessons from Uganda on the impacts of interactive screens PPGIS and community perceptions of space

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

On codes, matroids, and secure multiparty computation from linear secret-sharing schemes

Error-correcting codes and matroids have been widely used in the study of ordinary secret sharing schemes. In this paper, the connections between codes, matroids, and a special class of secret sharing schemes, namely, multiplicative linear secret sharing schemes (LSSSs), are studied. Such schemes are known to enable multiparty computation protocols secure against general (nonthreshold) adversaries.Two open problems related to the complexity of multiplicative LSSSs are considered in this paper. The first one deals with strongly multiplicative LSSSs. As opposed to the case of multiplicative LSSSs, it is not known whether there is an efficient method to transform an LSSS into a strongly multiplicative LSSS for the same access structure with a polynomial increase of the complexity. A property of strongly multiplicative LSSSs that could be useful in solving this problem is proved. Namely, using a suitable generalization of the well-known Berlekamp–Welch decoder, it is shown that all strongly multiplicative LSSSs enable efficient reconstruction of a shared secret in the presence of malicious faults. The second one is to characterize the access structures of ideal multiplicative LSSSs. Specifically, the considered open problem is to determine whether all self-dual vector space access structures are in this situation. By the aforementioned connection, this in fact constitutes an open problem about matroid theory, since it can be restated in terms of representability of identically self-dual matroids by self-dual codes. A new concept is introduced, the flat-partition, that provides a useful classification of identically self-dual matroids. Uniform identically self-dual matroids, which are known to be representable by self-dual codes, form one of the classes. It is proved that this property also holds for the family of matroids that, in a natural way, is the next class in the above classification: the identically self-dual bipartite matroids.

New ideas need new space

We develop a setting with weak intellectual property rights, where firms' boundaries, location and knowledge spillovers are endogenous. We have two main results. The first one is that, if communication costs increase with distance, entrepreneurs concerned about information leakage have a benefit from locating away from the industry center: distance is an obstacle to collusive trades between members andnon-members. The second result is that we identify a trade-off for the entrepreneur between owning a facility (controlling all its characteristics) and sharing a facility with a {\it non-member} (an agent not involved in production), therefore losing control over some of its characteristics. We focus on ``location" as the relevant characteristic of the facility, but location can be used as a spatial metaphor for other relevant characteristics of the facility. For theentrepreneur, sharing the facility with non-members implies that the latter, as co-owners, know the location (even if they do not have access to it). Knowledge of the location for the co-owners facilitates collusion with employees, what increases leakage. The model yields a benefit for new plants from spatial dispersion (locating at the periphery of the industry), particularly so for new plants of new firms.We relate this result with recent empirical findings on the dynamics of industry location.

Knowledge sharing in virtual communities

The Internet has transformed the scope, boundaries and dynamics of social and economic interactions. It is argued to have broadened the notion of the community from physical, colocated groups towards collectives that are able to transcend time and space, i.e. virtual communities. Even if virtual communities have been on the academic agenda for a couple of decades, there is still surprisingly little research on knowledge sharing within them. In addition, prior research has largely neglected the complex dynamics between Internet-based communication channels and the surrounding communities in which they are embedded. This thesis aims at building a better understanding of knowledge sharing supported by conversational technologies in intra-organisational virtual communities and external virtual communities supporting relationships with customers. The focus is thus on knowledge sharing in types of virtual communities that seem to be of relevance to business organisations. The study consists of two parts. The first part introduces the research topic and discusses the overall results. The second part comprises seven research publications. Qualitative research methods are used throughout the study. The results of the study indicate that investigation of the processes of knowledge sharing in virtual communities requires a socio-technical perspective, combining the individual, social and technological levels, and understanding the interplay between them. It is claimed that collective knowledge in virtual communities creates the enabling structure for knowledge sharing, and forms the invisible structure of the community on the basis of which it operates. It consists of a shared context, social capital and a unique community culture. The Internet does not inevitably erode social interaction: it seems that supporting social relationships by means of communication technology is a matter of quantity rather than quality. In order to provide access to external knowledge and expertise, firms need to open themselves up to an array of Internet-based conversations, and to consider the relevance of virtual communities to their businesses.

Design Space Exploration for MPSoC Architectures

Multiprocessor system-on-chip (MPSoC) designs utilize the available technology and communication architectures to meet the requirements of the upcoming applications. In MPSoC, the communication platform is both the key enabler, as well as the key differentiator for realizing efficient MPSoCs. It provides product differentiation to meet a diverse, multi-dimensional set of design constraints, including performance, power, energy, reconfigurability, scalability, cost, reliability and time-to-market. The communication resources of a single interconnection platform cannot be fully utilized by all kind of applications, such as the availability of higher communication bandwidth for computation but not data intensive applications is often unfeasible in the practical implementation. This thesis aims to perform the architecture-level design space exploration towards efficient and scalable resource utilization for MPSoC communication architecture. In order to meet the performance requirements within the design constraints, careful selection of MPSoC communication platform, resource aware partitioning and mapping of the application play important role. To enhance the utilization of communication resources, variety of techniques such as resource sharing, multicast to avoid re-transmission of identical data, and adaptive routing can be used. For implementation, these techniques should be customized according to the platform architecture. To address the resource utilization of MPSoC communication platforms, variety of architectures with different design parameters and performance levels, namely Segmented bus (SegBus), Network-on-Chip (NoC) and Three-Dimensional NoC (3D-NoC), are selected. Average packet latency and power consumption are the evaluation parameters for the proposed techniques. In conventional computing architectures, fault on a component makes the connected fault-free components inoperative. Resource sharing approach can utilize the fault-free components to retain the system performance by reducing the impact of faults. Design space exploration also guides to narrow down the selection of MPSoC architecture, which can meet the performance requirements with design constraints.

“Why share in uncertain conditions?” Factors of individual level knowledge sharing in offshoring cases

The objective of this Master’s Thesis was to research factors influencing and enhancing individual level knowledge sharing in offshore projects which often involve uncertainty of the knowledge provider’s own future. The purpose was to understand why individuals are willing to share their knowledge under these kinds of circumstances. In addition the goal was to identify obstacles to interpersonal knowledge sharing in order to understand how to mitigate their influence. The research was conducted as a qualitative multiple case study in a global IT company, and the data was gathered using semi-structured personal theme interviews within two different offshore projects. In order to a gain a wider perspective on the matter, some management representatives were interviewed as well. Data was analysed with the inductive content analysis method. Results of the study indicate that individuals are willing to share their knowledge despite of uncertainty if they are motivated, if they are provided with opportunities to do so, and if they have skills, competence and experience to share their knowledge. A strong knowledge sharing culture in the organization or team also works as a strong incentive for individual level knowledge sharing. The findings suggest that even under uncertain conditions it is possible to encourage people to share their knowledge if uncertainty can be decreased to a bearable level, a robust and personal connection and relationship between the knowledge provider and acquirer can be created and suitable opportunities for knowledge sharing are provided. In addition, based on the results the support and commitment of management and HR in addition to favourable environmental circumstances play an essential role in building a bridge between the knowledge provider and acquirer in order to create a virtual environment and space for knowledge sharing: Ba.

A Boolean algebra and a Banach space obtained by push-out iteration

Under the assumption that c is a regular cardinal, we prove the existence and uniqueness of a Boolean algebra B of size c defined by sharing the main structural properties that P(omega)/fin has under CH and in the N(2)-Cohen model. We prove a similar result in the category of Banach spaces. (C) 2011 Elsevier B.V. All rights reserved.

Breadcrumbs: location and context aware mobile platform for story sharing

With the current proliferation of sensor equipped mobile devices such as smartphones and tablets, location aware services are expanding beyond the mere efficiency and work related needs of users, evolving in order to incorporate fun, culture and the social life of users. Today people on the move have more and more connectivity and are expected to be able to communicate with their usual and familiar social networks. That means communications not only with their peers and colleagues, friends and family but also with unknown people that might share their interests, curiosities or happen to use the same social network. Through social networks, location aware blogging, cultural mobile applications relevant information is now available at specific geographical locations and open to feedback and conversations among friends as well as strangers. In fact, nowadays smartphone technologies aloud users to post and retrieve content while on the move, often relating to specific physical landmarks or locations, engaging and being engaged in conversations with strangers as much as their own social network. The use of such technologies and applications while on the move can often lead people to serendipitous discoveries and interactions. Throughout our thesis we are engaging on a two folded investigation: how can we foster and support serendipitous discoveries and what are the best interfaces for it? In fact, to read and write content while on the move is a cognitively intensive task. While the map serves the function of orienting the user, it also absorbs most of the user’s concentration. In order to address this kind of cognitive overload issue with Breadcrumbs we propose a 360 degrees interface that enables the user to find content around them by means of scanning the surrounding space with the mobile device. By using a loose metaphor of a periscope, harnessing the power of the smartphone sensors we designed an interactive interface capable of detecting content around the users and display it in the form of 2 dimensional bubbles which diameter depends on their distance from the users. Users will navigate the space in relation to the content that they are curious about, rather than in relation to the traditional geographical map. Through this model we envisage alleviating a certain cognitive overload generated by having to continuously confront a two dimensional map with the real three dimensional space surrounding the user, but also use the content as a navigational filter. Furthermore this alternative mean of navigating space might bring serendipitous discovery about places that user where not aware of or intending to reach. We hence conclude our thesis with the evaluation of the Breadcrumbs application and the comparison of the 360 degrees interface with a traditional 2 dimensional map displayed on the devise screen. Results from the evaluation are compiled in findings and insights for future use in designing and developing context aware mobile applications.

Genetic algorithm based distance spectrum technique for performance union bound of space-time trellis coded OFDM

This paper derives the performance union bound of space-time trellis codes in orthogonal frequency division multiplexing system (STTC-OFDM) over quasi-static frequency selective fading channels based on the distance spectrum technique. The distance spectrum is the enumeration of the codeword difference measures and their multiplicities by exhausted searching through all the possible error event paths. Exhaustive search approach can be used for low memory order STTC with small frame size. However with moderate memory order STTC and moderate frame size the computational cost of exhaustive search increases exponentially, and may become impractical for high memory order STTCs. This requires advanced computational techniques such as Genetic Algorithms (GAS). In this paper, a GA with sharing function method is used to locate the multiple solutions of the distance spectrum for high memory order STTCs. Simulation evaluates the performance union bound and the complexity comparison of non-GA aided and GA aided distance spectrum techniques. It shows that the union bound give a close performance measure at high signal-to-noise ratio (SNR). It also shows that GA sharing function method based distance spectrum technique requires much less computational time as compared with exhaustive search approach but with satisfactory accuracy.

Automatic and adaptable registration of live RGBD video streams sharing partially overlapping views

In this thesis, we introduce DeReEs-4v, an algorithm for unsupervised and automatic registration of two video frames captured depth-sensing cameras. DeReEs-4V receives two RGBD video streams from two depth-sensing cameras arbitrary located in an indoor space that share a minimum amount of 25% overlap between their captured scenes. The motivation of this research is to employ multiple depth-sensing cameras to enlarge the field of view and acquire a more complete and accurate 3D information of the environment. A typical way to combine multiple views from different cameras is through manual calibration. However, this process is time-consuming and may require some technical knowledge. Moreover, calibration has to be repeated when the location or position of the cameras change. In this research, we demonstrate how DeReEs-4V registration can be used to find the transformation of the view of one camera with respect to the other at interactive rates. Our algorithm automatically finds the 3D transformation to match the views from two cameras, requires no human interference, and is robust to camera movements while capturing. To validate this approach, a thorough examination of the system performance under different scenarios is presented. The system presented here supports any application that might benefit from the wider field-of-view provided by the combined scene from both cameras, including applications in 3D telepresence, gaming, people tracking, videoconferencing and computer vision.

Meating the social: sharing atiku-euiash in Sheshatshiu, Labrador

This work examines atiku-euiash (caribou meat) sharing practices in Sheshatshiu, Newfoundland and Labrador, and aims to elucidate an overarching question: how do sharing practices participate in the co-constitution of the Innu ‘social’? The ‘social’ is understood in this work as a descriptor that refers to the emergent properties of the Innu collective. The thesis is that sharing practices participate in the co-constitution of the Innu social and enact its boundaries. Inside these boundaries, atiku-euiash is more than simply a food resource: by realizing Innu values of generosity, respect and autonomy, sharing implicates the associations of human, animal, and animal masters that constitute the Innu world. Sharing is connected with the enskilment of the younger generations by their el-ders, and thus with the reproduction of Innu values through time. The ways of sharing are relevant because changes in such practices affect the constitution of the Innu social. Giv-en Euro-Canadian colonization, the Innu are in a fraught social space in which sharing is interrupted by colonization practices and values. Understanding sharing is necessary to develop policies that do not interrupt the reproduction of the Innu world This work uses several research methods: participant observation, sharing surveys, and interviews. It also uses network analysis as sharing practices leave traces of giving and receiving actions and these traces can be represented as a network of givers, receivers and circulating caribou meat. There are two main ways in which caribou is hunted and shared: household-based hunts and community-based hunts. The household-based hunts are organized by the hunters themselves, who are able and willing to hunt. Community-based hunts are completely organized and funded by the SIFN or the Innu Nation. In or-der to understand the differences in the distribution of the two hunt types, the categories of centrality and clustering are used to show how the flow of atiku-eiuash and its associ-ated realization of values and enskilment correlate with different degrees of centralization inside the sharing clusters.

Open Space – Estratégia e Concretização: o caso EDP Porto

Este estudo centra-se numa investigação sobre o conceito de trabalho em open space na nova sede no Porto da empresa Energias de Portugal - SA, tendo em conta a estratégia implementada e os resultados conseguidos. Para isso, dissecámos as premissas apresentadas aos trabalhadores na cerimónia de inauguração do novo espaço - “O Open Space opera como plataforma de comunicação e de partilha de informação” e “O Open Space responde às necessidades dos trabalhadores, criando ambientes de trabalho modernos e funcionais”. A fim de avaliarmos o campo empírico, construímos e enviámos em formato eletrónico para o e-mail de todos os trabalhadores da amostra um instrumento de medida que denominámos de open space (OS). As ilações retiradas estão baseadas nos resultados analisados e discutidos após processamento em SPSS - predictive analytics software and solutions e em reports gráficos. O open space da EDP Porto é um local moderno e funcional, privilegiado em relação à fluidez e partilha de informação, capaz de manifestar estratégias de negócio e de salientar aspetos da marca e da cultura da Empresa. A formação/informação sobre comportamentos e regras básicas a seguir na partilha de um mesmo espaço, as razões de negócio que levam a organização a mudar o espaço de trabalho, a par das vantagens que ambas as partes podem tirar do novo conceito, influencia positivamente ou negativamente a perceção da mudança e o estado emocional dos trabalhadores. O ruído, a temperatura ambiente, a concentração ou a privacidade, são alguns dos fatores que poderão variar com o layout e funcionam como condicionantes de uma maior ou menor satisfação ambiental. No entanto, existem sempre questões que permanecem pendentes e foi nesse contexto que deixámos algumas propostas para novas investigações num trabalho científico que nunca se esgota. / This study focuses on researching the concept of working in an open space in the new Oporto’s headquarters of the company Energias de Portugal - SA, given the strategy implemented and the results achieved. For this, we dissected the assumptions presented to workers at the inauguration ceremony of the new space - "The Open Space operates as a platform for communication and information sharing" and "The Open Space responds to the needs of workers, creating modern and functional workplaces". In order to evaluate the empirical side, we built and sent, in electronic format, an e-mail to all the workers of the sample with a measurement tool that we called the open space (OS). The conclusions are based on the results analyzed and discussed after being processed in SPSS - predictive analytics software and solutions and graphs in reports. The open space of the EDP Oporto is a modern and functional place, privileged in relation to fluidity and information sharing, capable of manifesting business strategies and highlight aspects of the brand and culture of the Company. The training/information on behaviors and basic rules to follow when sharing the same space, the business reasons that lead the organization to change the workspace, along with the advantages that both parties can benefit from the new concept, influence positively or negatively the perception of change and the emotional state of workers. Noise, temperature, concentration or privacy, are some of the factors that may vary with the layout and function as constraints in a greater or lesser environmental satisfaction. However, there are always issues that remain outstanding and it was in this context that we made some proposals for further research in a scientific paper that never runs out.