A tese discute o tema contemporâneo do ganho indireto dos cooperados de sociedades cooperativas de produção agropecuária e agroindustriais. Procura responder por quais diferentes maneiras essas organizações adicionam valor econômico aos cooperados, e como os cooperados percebem as diferentes categorias de benefícios econômicos e não-econômicos. Foi realizada análise da cooperação na linha teórica da Nova Economia Institucional (NEI), com ênfase no mapeamento das percepções econômicas e não-econômicas dos cooperados nas relações existentes com a sociedade cooperativa de produção agropecuária e, ainda, na ótica da teoria da renda, com a análise dos benefícios econômicos e sociais do cooperado produtor rural pessoa física dentro da sociedade cooperativa de produção agropecuária. Para o estudo de caso, utilizaram-se como fonte de informações entrevistas com técnicos especializados e aplicação de questionários aos cooperados, cuja finalidade foi extrair dados qualitativos das sociedades cooperativas de produção agropecuárias e agroindustriais, de objetos sociais variados, localizadas no Estado do Rio Grande do Sul. Constataram-se transferências indiretas pelas sociedades cooperativas que são percebidas pelos cooperados na forma de ganhos pecuniários e não-pecuniários. Os ganhos não-pecuniários são relacionados ao status, conforto, conhecimento, segurança, entre outros, descritos como privilégios no âmbito dessas organizações. Tais ganhos não são voltados ao aumento de riqueza, mas contribuem para o aumento do bem-estar de todos os cooperados. Então, ao fim, é possível formular a conclusão que os cooperados percebem os ganhos indiretos das mais variadas formas, principalmente pela melhoria do bem-estar econômico e social. / The thesis discusses a contemporary theme on the indirect gain of members of the agricultural production cooperative society. It seeks to answer by which different ways these organizations add economic value to the cooperative member and how the member realize the various categories of economic and non-economic benefits. An analysis of cooperation was conducted under the theoretical framework of the New Institutional Economics - NIE, emphasizing the mapping of economic and non-economic perceptions of the existing cooperative relations with agricultural production cooperative society and yet from the perspective of the theory of income, analysis of the economic and social benefits of the cooperative member rural producer as individual into the cooperative agricultural production. To the case study, it were used as a source of information interviews with technical experts and applied questionnaires to cooperative members, to obtain qualitative data of agricultural and agro-industrial production cooperative societies, of various corporate purposes, located in the state of Rio Grande do Sul, Brazil. Forms of indirect transfers from cooperative societies are perceived by the cooperative members as pecuniary and non-pecuniary gain. The non-pecuniary gain is related to status, comfort, knowledge, security among others, described as privileges within those organizations. These gains are not geared to increasing wealth, but contribute to increase the well-being of all cooperative members. Therefore, in the end, one can conclude that the cooperative realize the indirect gains in the most variable ways, mainly by improving economic and social well-being.

Tourism has come to be recognised as a major contributor to national economies. In a knowledge-based economy (that emphasises the benefits of industry/government and academic research), a strong research base must underpin management of a tourist destination if it is to realise its full potential. The establishment of collaborative networks between industry, academia, and government in the strategic planning and management of cities and towns is becoming increasingly popular. However, the way in which the processes underlying these settings facilitate or inhibit eventual outcomes is poorly understood. If knowledge is to drive innovation and economic growth optimally, it is important not just to develop an understanding of the processes underlying the creation, diffusion and utilisation of knowledge in cooperative research settings, but also the relationships among them. Accordingly, the aim of this investigation is to examine the relationships among knowledge creation, diffusion and utilisation occurring in the Cooperative Research Centres (CRC) Program, specifically, the Gold Coast Visioning Project, with a view to identifying the most efficient means for formulating and disseminating research designed for industry and/or government application. Knowledge is defined as information that is imbued with meaning or relevance. However, this definition says little of the ways that individuals, groups and organisations acquire knowledge. While cognitive psychologists have produced several theories suggesting the structure and mechanisms of individual cognitive processes underlying the acquisition and use of knowledge, social scientists have sought to describe and explain the process by investigating the influence of social factors. Recent contributions to group learning have examined group composition, group size, familiarity among group members, and communication processes in an attempt to understand the ways in which groups acquire knowledge. Research shows that knowledge utilisation in organisations results from the interdependent influences of organisational processes and the control opportunities and control problems that arise through organisational structure. These frameworks provide accounts of how knowledge is utilised within an organisation, but not of how organisations learn. Recent research suggests that organisations learn through knowledge networks where organisational focus moves from the consideration and protection of boundaries to the management of (and care for) relationships. Therefore, organisations contain static (rules, norms and procedures) and dynamic (social relationships) elements that mutually influence the degree to which organisations learn. A synthesis of the available literature resulted in the development of a series of models that served not only to inform, but also be informed by the analysis of this investigation. A single case study, namely the Gold Coast Visioning Project, was used to examine the ways in which knowledge was created, disseminated and utilised in a CRC setting. This ethnographic investigation considered the process of knowledge creation through to utilisation at individual, group, organisational, and inter-organisational levels, while simultaneously examining the interrelated influences of social, cognitive, affective and communication factors. Throughout the project, data were collected through stakeholder interviews, various documents and participant observation of stakeholder meetings and workshops. Data were analysed using a grounded theory approach and methods of thick description. The results show that researchers and industry stakeholders bring different frames of reference, different expectations, and different knowledge bases to the exercise. This inhibited communication, and gave the appearance of dissension when, in fact, what was being sought was a common frame for understanding and communication. Additionally, the gap between industry and researcher worldviews generated the sense that industry was resisting or failing to understand what the research was seeking to achieve. Consequently, in order to manage the relationship, research plans and findings were communicated to industry in a teacher-to-student fashion, which fostered single-loop learning, and reduced industry stakeholders' sense of ownership in the process and findings. During the project, industry stakeholders frequently sought to have research come pre-packaged with "meaning", but researchers lacked the contextual knowledge necessary to specify the relevance of their research. The results also show that research findings need to be integrated and diffused to industry over time, and specific applications need to be formulated (and reformulated) in response to particular and changing needs of industry. As a result of this investigation, a model of 'best practice' has been developed with detailed recommendations for the design, implementation, and reporting of CRC-sponsored research to optimise its utility for end-users of such research. From a theoretical perspective, the findings of this study challenge the ways that current theories account for the ways in which knowledge is acquired and utilised since the results show that knowledge is constructed both socially and emotionally. Any investigation that seeks to understand how knowledge is acquired and utilised must consider social and affective influences. To ignore the role of emotion and values in the process of knowledge acquisition is to ignore a key component of an individual's reasoning capacity.

In recent years, global mobile data traffic has been increasing exponentially as mobile devices pervade our daily lives. To cope with the ever growing demands for higher data rates and seamless connectivity, one solution is to drastically increase the number of macro base stations in the conventional cellular architecture. However, this results in high deployment costs. Deploying low-power nodes such as relays that do not require a wired backhaul connection within a macrocell is one of cost-effective ways to extend high data rate coverage range. Relays are typically deployed to increase signal strength in poor coverage areas or to eliminate dead spots. But more importantly, relays provide a natural diversity, called cooperative diversity. In addition to a direct signal from a base station, extra copies of the same signal are forwarded from relays. Utilizing this diversity at the destination can yield significant performance enhancements. Thus, cooperative relay strategies need to be considered to enable high data rate coverage in a cost-effective manner. In this dissertation, we consider a simple single-relay network and present low-complexity and power-efficient cooperative relay designs that can achieve low error rate. We first study decode-and-forward (DF) relay networks with a single antenna at each node, where the relay decodes the received signal and forwards the re-encoded information to the destination. In DF relay scheme, decoding at the relay is not perfect and the error-propagation phenomenon is a detrimental problem, preventing the destination from collecting the cooperative diversity. To enable cooperative diversity in DF relay networks, we adopt link-adaptive power-scaling relay strategies where the relay scales the transmission power of the re-encoded signal based on the reliability of the source-relay link. We generalize power-profile designs and analyze the diversity order enabled by the general power-profile designs. We provide necessary and sufficient conditions for the designs to enable full cooperative diversity at the destination. In the second part of this dissertation, we extend the power-scaling relay strategy to DF multi-input multi-output (MIMO) relay networks, where multiple antennas are adopted at each node, and show that full cooperative diversity can also be achieved here. To collect spatial diversity provided by multiple antennas without using maximum-likelihood equalizers (MLEs) or near-ML detectors which exhibit high complexity, channel-controlled automatic repeat request (CC-ARQ) scheme is developed for DF MIMO relay networks to enable spatial diversity with linear equalizers (LEs) maintaining low-complexity. We also show that joint cooperative and spatial diversity can be achieved at the destination when the power-scaling strategy and the CC-ARQ with LEs are combined. Finally, amplify-and-forward (AF) MIMO relay designs, where the relay simply amplifies the received signal and forwards it to the destination, are studied with consideration of peak-power constraints at the relay. One practical concern for AF relaying is that the output signal at the relay may suffer from large peak-to-average power ratio (PAR), which may cause nonlinear distortion and/or saturation in the transmitted signal due to the limited linear range of power amplifiers. Thus, we first investigate peak-power constrained power-scaling strategies and find a sufficient condition to enable joint cooperative and spatial diversity at the destination. Based on this study, we propose simple and practical AF MIMO relay designs with peak-power constraint at the relay. CC-ARQ is also applied to AF MIMO relay networks to reduce the decoding complexity.

La presente tesis doctoral contribuye a la incesante evolución de las comunicaciones inalámbricas. Se centra en el diseño de protocolos de acceso al medio (MAC) para redes ad hoc y redes inalámbricas cooperativas. En una primera parte introductoria se presenta un minucioso estado del arte y se establecen las bases teóricas de las contribuciones presentadas en la tesis. En esta primera parte introductoria se definen las principales motivaciones de la tesis y se plantean los objetivos. Después, las contribuciones de la tesis se organizan en dos grandes bloques, o partes. En la primera parte de esta tesis se diseña, analiza y evalúa el rendimiento de un novedoso protocolo MAC de alta eficiencia llamado DQMAN (Protocolo MAC basado en colas distribuidas para redes ad hoc). Este protocolo constituye la extensión y adaptación del protocolo DQCA, diseñado para redes centralizadas, para operar en redes sin infraestructura. En DQMAN se introduce un nuevo paradigma en el campo del acceso al medio para redes distribuidas: la integración de un algoritmo de clusterización espontáneo y dinámico basado en una estructura de master y esclavo junto con un protocolo MAC de alta eficiencia diseñado para redes centralizadas. Tanto el análisis teórico como las simulaciones por ordenador presentadas en esta tesis muestran que DQMAN mejora el rendimiento del actual estándar IEEE 802.11. La principal característica de DQMAN es que se comporta como un protocolo de acceso aleatorio cuando la carga de tráfico es baja y cambia automática y transparentemente a un protocolo de reserva a medida que el tráfico de la red aumenta. Además, su rendimiento es prácticamente independiente del número de usuarios simultáneos de la red, lo cual es algo deseable en redes que nacen para cubrir una necesidad espontánea y no pueden ser planificadas. El hecho de que algoritmo de clusterización se base en un acceso aleatorio permite la coexistencia e intercomunicación de usuarios DQMAN con usuarios basados en el estándar IEEE 802.11. Este estudio se presenta en esta primera parte de la tesis y es fundamental de cara a una posible explotación comercial de DQMAN. La metodología presentada en esta tesis mediante el cual se logra extender la operación de DQCA a entornos ad hoc sin infraestructura puede ser utilizada para adaptar cualquier otro protocolo centralizado. Con el objetivo de poner de manifiesto esta realidad, la primera parte de la tesis concluye con el diseño y evaluación de DPCF como una extensión distribuida del modo de coordinación centralizado (PCF) del estándar IEEE 802.11 para operar en redes distribuidas. La segunda parte de la tesis se centra en el estudio de un tipo específico de técnicas cooperativas: técnicas cooperativas de retransmisión automática (C-ARQ). La idea principal de las técnicas C-ARQ es que cuando un paquete de datos se recibe con bits erróneos, se solicita retransmisión, no a la fuente de datos, si no a cualquiera de los usuarios que escuchó la transmisión original. Estos usuarios se convierten en espontáneos retransmisores que permiten mejorar la eficiencia de la comunicación. A pesar de que este tipo de esquema puede obtener diversidad de cooperación, el hecho de implicar a más de un usuario en una comunicación punto a punto requiere una coordinación que hasta ahora ha sido obviada en la literatura, asumiendo que los retransmisores pueden coordinarse perfectamente para retransmitir uno detrás de otro. En esta tesis se analiza y evalúa el coste de coordinación impuesto por la capa MAC y se identifican los principales retos de diseño que las técnicas C-ARQ imponen al diseño de la capa MAC. Además, se presenta el diseño y análisis de dos novedosos protocolos MAC para C-ARQ: DQCOOP y PRCSMA. El primero se basa en DQMAN y constituye una extensión de este para operar en esquemas C-ARQ, mientras que el segundo constituye la adaptación del estándar IEEE 802.11 para poder ejecutarse en un esquema C-ARQ. El rendimiento de estos esquemas se compara en esta tesis tanto con esquemas no cooperativos como con esquemas ideales cooperativos donde se asume que el MAC es ideal. Los resultados principales muestran que el diseño eficiente de la capa MAC es esencial para obtener todos los beneficios potenciales de los esquemas cooperativos. / This thesis aims at contributing to the incessant evolution of wireless communications. The focus is on the design of medium access control (MAC) protocols for ad hoc and cooperative wireless networks. A comprehensive state of the art and a background on the topic is provided in a first preliminary part of this dissertation. The motivations and key objectives of the thesis are also presented in this part. Then, the contributions of the thesis are divided into two fundamental parts. The first part of the thesis is devoted to the design, analysis, and performance evaluation of a new high-performance MAC protocol. It is the Distributed Queueing MAC Protocol for Ad hoc Networks (DQMAN) and constitutes an extension and adaptation of the near-optimum Distributed Queueing with Collision Avoidance (DQCA) protocol, designed for infrastructure-based networks, to operate over networks without infrastructure. DQMAN introduces a new access paradigm in the context of distributed networks: the integration of a spontaneous, dynamic, and soft-binding masterslave clustering mechanism together with a high-performance infrastructure-based MAC protocol. Theoretical analysis and computer-based simulation show that DQMAN outperforms IEEE 802.11 Standard. The main characteristic of the protocol is that it behaves as a random access control protocol when the traffic load is low and it switches smoothly and automatically to a reservation protocol as the traffic load grows. In addition, its performance is almost independent of the number of users of a network. The random-access based clustering algorithm allows for the coexistence and intercommunication of stations using DQMAN with the ones just based on the legacy IEEE 802.11 Standard. This assessment is also presented in this first part of the dissertation and constitutes a key contribution in the light of the commercial application of DQMAN. Indeed, the rationale presented in this first part of the thesis to extend DQCA and become DQMAN to operate over distributed networks can be used to extend the operation of any other infrastructure-based MAC protocol to ad hoc networks. In order to exemplify this, a case study is presented to conclude the first part of the thesis. The Distributed Point Coordination Function (DPCF) MAC protocol is presented as the extension of the PCF of the IEEE 802.11 Standard to be used in ad hoc networks. The second part of the thesis turns the focus to a specific kind of cooperative communications: Cooperative Automatic Retransmission Request (C-ARQ) schemes. The main idea behind C-ARQ is that when a packet is received with errors at a receiver, a retransmission can be requested not only from the source but also to any of the users which overheard the original transmission. These users can become spontaneous helpers to assist in the failed transmission by forming a temporary ad hoc network. Although such a scheme may provide cooperative diversity gain, involving a number of users in the communication between two users entails a complicated coordination task that has a certain cost. This cost has been typically neglected in the literature, assuming that the relays can attain a perfect scheduling and transmit one after another. In this second part of the thesis, the cost of the MAC layer in C-ARQ schemes is analyzed and two novel MAC protocols for C-ARQ are designed, analyzed, and comprehensively evaluated. They are the DQCOOP and the Persistent Relay Carrier Sensing Multiple Access (PRCSMA) protocols. The former is based on DQMAN and the latter is based on the IEEE 802.11 Standard. A comparison with non-cooperative ARQ schemes (retransmissions performed only from the source) and with ideal CARQ (with perfect scheduling among the relays) is included to have actual reference benchmarks of the novel proposals. The main results show that an efficient design of the MAC protocol is crucial in order to actually obtain the benefits associated to the C-ARQ schemes.

Solving the key issue of sustainability of battery-powered sensors continues to attract significant research attention. The prevailing theme of this research is to address this concern using energy-efficient protocols based on a form of simple cooperative transmission (CT) called the opportunistic large arrays (OLAs), and intelligent exploitation of energy harvesting and hybrid energy storage systems (HESSs). The two key contributions of this research, namely, OLA with transmission threshold (OLA-T) and alternating OLA-T (A-OLA-T), offer an signal-to-noise ratio (SNR) advantage (i.e., benefits of diversity and array (power) gains) in a multi-path fading environment, thereby reducing transmit powers or extending range. Because these protocols do not address nodes individually, the network overhead remains constant for high density networks or nodes with mobility. During broadcasting across energy-constrained networks, while OLA-T saves energy by limiting node participation within a single broadcast, A-OLA-T optimizes over multiple broadcasts and drains the the nodes in an equitable fashion. Another important contribution of this research is the design and analysis of a novel routing metric called communications using HESS (CHESS), which extends the rechargeable battery (RB)-life by relaying exclusively with supercapacitor (SC) energy, and is asymptotically optimal with respect to the number of nodes in the network.

For large multihop networks, the time synchronization (TS) error accumulates as the hop number increases with conventional methods, such as Timing-sync Protocol for Sensor Networks (TPSN), Reference Broadcast Synchronization (RBS), and Flooding Time Synchronization Protocol (FTSP). In this paper, to reduce the number of hops to cover the large network and exploit the spatial averaging of TS error between clusters, a novel method combining Concurrent Cooperative Transmission (CCT) and Semi-Cooperative Spectrum Fusion (SCSF) is proposed. This novel method named Cooperative Analog and Digital (CANDI) Time Synchronization protocol consists of two phases: The digital stage and the analog stage. The digital stage uses CCT to broadcast TS packet containing the time information. Cooperating nodes transmit the digitally encoded message in orthogonal channels simultaneously, so the receiver combines the multiple packet to acheive significant SNR advantage. In the analog stage, the cooperating nodes simultaneously transmit their slightly different individual estimates of the propagation time by using frequency shift modulation. Nodes receiving this signal combat fading and reduce estimation error in one step through the averaging inherent in diversity combining. Simulation results for two-dimension (2-D) networks are given to evaluate the performance of CANDI, and CANDI is compared with TPSN.

This MA Report explains the impact coffee cooperatives are having on the Ethiopian coffee industry. It analyses how the current multi-billion dollar global coffee industry began in what remains one of the world’s poorest countries, where arabica coffee was discovered sometime before the sixth century. It explains the emergence of coffee cooperatives historically, as well as their present role offering an alternative to the country’s previous reliance on the assistance of Western nongovernmental organizations with their possible negative impact, including arguments they enforced a dependency on Ethiopia that impeded the country’s development. In discussing coffee buyers and coffee consumption, the report focuses on America, although the same points made apply to the vast majority of Western countries. The report investigates whether cooperatives offer a business model sufficient to achieve self-sustainability for Ethiopian coffee farmers, and discusses how the interaction between and among cooperatives, unions, the Ethiopian government, and specialty coffee buyers in America is enabling Ethiopian coffee to increase its leverage on the international coffee market, generating essential income for the struggling Ethiopian economy. The report focuses on the following areas: the connection between poverty and linkage to markets; how coffee travels from smallholding farmers in Ethiopia to be sold in American cities like Austin, Texas; the emergence of certification systems like Fair Trade to protect farmers and ensure they receive a fair price for their produce, as well as the chain of commerce that Fair Trade is part of; the quality and characteristics of Ethiopian coffee; and whether cooperatives and unions can remain true to the original goals of serving their farmer members—not turning into purely profit-orientated businesses. While this report focuses on Ethiopia, it dissects and debates economic trends that usually affect developing nations producing coffee. It explores the logistics and ethics of prices paid in the West for coffee from developing countries like Ethiopia. The report ultimately aims to enlighten readers so they’re able to make an ethical purchase of a good quality coffee, while aware of the myriad factors and trends affecting the international coffee market. / text

No description available.

Concurrent cooperative transmission (CCT) occurs when a collection of power-constrained single-antenna radios transmit simultaneously to form a distributed multi-input and multi-output (DMIMO) link. DMIMO can be a means for highly reliable and low-latency cooperative routing, when the MIMO channel is exploited for transmit and receive diversity; in this context, the range extension benefit is emphasized. Alternatively, DMIMO can be a means for high-throughput ad hoc networking, when the MIMO channel is used with spatial multiplexing. In both cases, concatenated DMIMO links are treated. The key contribution of this dissertation is a method of pre-synchronization of distributed single-antenna transmitters to form a virtual antenna array, in the absence of a global clock, such as a global positioning system (GPS) receiver or a network time protocol (NTP) to provide reference signals for the synchronization. Instead, the reference for synchronization comes from a packet, transmitted by the previous virtual array and simultaneously received by all the cooperative transmitters for the next hop. The method is realized for two types of modulation: narrowband non-coherent binary frequency-shift keying (NCBFSK) and wideband orthogonal frequency division multiplexing (OFDM). The pre-synchronization algorithms for transmission are designed to minimize the root-mean-square (RMS) transmit time, sampling and carrier frequency error between cooperative transmitters, with low implementation complexity. Since CCT is not supported by any existing standard or off-the-shelf radios, CT must be demonstrated by using software-defined radios (SDRs). Therefore, another contribution is a fully self-contained and real-time SDR testbed for CCT-based networking. The NCBFSK and OFDM systems have been designed and implemented in C++ and Python programming languages in the SDR testbed, providing practical performance of the CCT-based systems.

Thesis (Ph. D.)--University of Wisconsin, 1963. / Extension Repository Collection. Typescript (carbon copy). Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 170-174).