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To solve the problems of energy limitation, spectrum shortage, and serious co-frequency interference in the unmanned aerial vehicle (UAV)-assisted D2D (device-to-device) communication network under passive eavesdropping, the concept of the network secrecy energy efficiency was introduced by taking into account the secrecy rate and transmit power constraints of each user.Based on the physical layer secure transmission theory, the joint optimization problem of spectrum multiplexing and power control strategies was investigated to maximize the network secrecy energy efficiency.The problem was a nonlinear nonconvex problem, a resource allocation algorithm combining Dinkelbach’s algorithm and the convex approximation algorithm was proposed to transform the nonconvex optimization problem into a geometric planning problem through the convex approximation algorithm and ensure that the original problem converges to the global optimal solution by Dinkelbach’s algorithm.Simulation results show that the proposed algorithm can effectively mitigate the co-channel interference, improve the network secrecy energy efficiency, and balance the relationship between the secure communication performance and power consumption of the network.

To solve the problems of energy limitation, spectrum shortage, and serious co-frequency interference in the unmanned aerial vehicle (UAV)-assisted D2D (device-to-device) communication network under passive eavesdropping, the concept of the network secrecy energy efficiency was introduced by taking into account the secrecy rate and transmit power constraints of each user.Based on the physical layer secure transmission theory, the joint optimization problem of spectrum multiplexing and power control strategies was investigated to maximize the network secrecy energy efficiency.The problem was a nonlinear nonconvex problem, a resource allocation algorithm combining Dinkelbach’s algorithm and the convex approximation algorithm was proposed to transform the nonconvex optimization problem into a geometric planning problem through the convex approximation algorithm and ensure that the original problem converges to the global optimal solution by Dinkelbach’s algorithm.Simulation results show that the proposed algorithm can effectively mitigate the co-channel interference, improve the network secrecy energy efficiency, and balance the relationship between the secure communication performance and power consumption of the network.

Bu çalışma, 1990-2016 döneminde koordineli piyasa ekonomileri için tarımsal katma değerin, orman alanlarının, ekonomik büyümenin ve yenilenebilir ve yenilenemez enerji tüketiminin çevresel kalite üzerindeki etkisini panel Common Corelated Effects (CCE) modelini kullanarak incelemeyi amaçlamaktadır. Panel CCE modelinden elde edilen uzun dönem katsayılara göre orman alanlarının çevre kalitesini arttırdığı, başka bir ifadeyle karbondioksit emisyonunu azalttığı, yenilenemez enerji tüketiminin ve ekonomik büyümenin ise çevre kalitesi üzerinde negatif bir etki oluşturduğu tespit edilmiştir. Ayrıca, incelenen dönemde tarımsal katma değerin ve yenilenebilir enerji tüketiminin çevre kalitesi üzerinde bir etki oluşturmadığı görülmüştür. Son olarak değişkenler arasındaki nedensellik ilişkisi Dumitrescu–Hurlin testi ile araştırılmıştır. Uygulanan nedensellik testi ile tarım ile karbondioksit emisyonları, tarım ile yenilenemez enerji tüketimi, yenilenebilir enerji tüketimi ile yenilenemez enerji tüketimi arasında çift yönlü nedensellik ilişkisi elde edilmiştir.

Bu çalışma, 1990-2016 döneminde koordineli piyasa ekonomileri için tarımsal katma değerin, orman alanlarının, ekonomik büyümenin ve yenilenebilir ve yenilenemez enerji tüketiminin çevresel kalite üzerindeki etkisini panel Common Corelated Effects (CCE) modelini kullanarak incelemeyi amaçlamaktadır. Panel CCE modelinden elde edilen uzun dönem katsayılara göre orman alanlarının çevre kalitesini arttırdığı, başka bir ifadeyle karbondioksit emisyonunu azalttığı, yenilenemez enerji tüketiminin ve ekonomik büyümenin ise çevre kalitesi üzerinde negatif bir etki oluşturduğu tespit edilmiştir. Ayrıca, incelenen dönemde tarımsal katma değerin ve yenilenebilir enerji tüketiminin çevre kalitesi üzerinde bir etki oluşturmadığı görülmüştür. Son olarak değişkenler arasındaki nedensellik ilişkisi Dumitrescu–Hurlin testi ile araştırılmıştır. Uygulanan nedensellik testi ile tarım ile karbondioksit emisyonları, tarım ile yenilenemez enerji tüketimi, yenilenebilir enerji tüketimi ile yenilenemez enerji tüketimi arasında çift yönlü nedensellik ilişkisi elde edilmiştir.

Abstract The effect of the thermal environment on performance and productivity has been a focus of interest among indoor environmental researchers for nearly a century, but most of that work has been conducted in relative isolation from the cognate disciplines of human performance evaluation. The present review examines thermal environmental effects on cognitive performance research conducted across multiple disciplines. After differentiating performance from productivity, we compare the two dominant conceptual models linking thermal stress to performance; (1) the inverted-U concept and (2) the extended-U relationship. The inverted-U specifies a single optimum temperature (or its corresponding subjective thermal sensation) at which performance is maximised. In contrast, the extended-U model posits a broad central plateau across which there is no discernible thermal effect on cognitive performance. This performance plateau is bounded by regions of progressive performance decrements in more extreme thermal conditions. The contradictions between these opposing conceptual models might derive from various confounding factors at play in their underlying research bases. These include, inter alia, environment-related, task-related, and performer-related factors, as well as their associated two-way and three-way interaction effects. Methodological discrepancies that might also contribute to the divergence of these conceptual models are evaluated, along with the proposed causal mechanisms underlying the two models. The weight of research evidence reviewed in this paper suggests that the extended-U hypothesis fits the relationship between moderate thermal environments and cognitive performance. In contrast to the inverted-U relationship, implemention of the extended-U in indoor climate control implies substantial reductions in building energy demand, since it permits the heating and cooling setpoint deadband to expand across the full width of the thermal comfort zone, or even slightly further during emergencies such as peak demand events on the electricity grid. Use of personal comfort systems can further extend the thermostat setpoint range beyond the comfort zone.

Abstract The effect of the thermal environment on performance and productivity has been a focus of interest among indoor environmental researchers for nearly a century, but most of that work has been conducted in relative isolation from the cognate disciplines of human performance evaluation. The present review examines thermal environmental effects on cognitive performance research conducted across multiple disciplines. After differentiating performance from productivity, we compare the two dominant conceptual models linking thermal stress to performance; (1) the inverted-U concept and (2) the extended-U relationship. The inverted-U specifies a single optimum temperature (or its corresponding subjective thermal sensation) at which performance is maximised. In contrast, the extended-U model posits a broad central plateau across which there is no discernible thermal effect on cognitive performance. This performance plateau is bounded by regions of progressive performance decrements in more extreme thermal conditions. The contradictions between these opposing conceptual models might derive from various confounding factors at play in their underlying research bases. These include, inter alia, environment-related, task-related, and performer-related factors, as well as their associated two-way and three-way interaction effects. Methodological discrepancies that might also contribute to the divergence of these conceptual models are evaluated, along with the proposed causal mechanisms underlying the two models. The weight of research evidence reviewed in this paper suggests that the extended-U hypothesis fits the relationship between moderate thermal environments and cognitive performance. In contrast to the inverted-U relationship, implemention of the extended-U in indoor climate control implies substantial reductions in building energy demand, since it permits the heating and cooling setpoint deadband to expand across the full width of the thermal comfort zone, or even slightly further during emergencies such as peak demand events on the electricity grid. Use of personal comfort systems can further extend the thermostat setpoint range beyond the comfort zone.

Construction involves the use of significant quantities of raw materials and entails high-energy consumption. For the sake of choosing the most appropriate solution that considers environmental and sustainable concepts, tools such as the integrated value model for sustainable assessment (Modelo Integrado de Valor para una Evaluación Sostenible, MIVES) used in Spain, plays a key role in obtaining the best solution. MIVES is a multi-criteria decision-making method based on the value function concept and the seminars delivered by experts. Such tools, in order to show how they may work, require application to case studies. In this paper, two concrete slabs manufactured with differing reinforcements during the construction of the La Canda Tunnels are compared by means of MIVES. The two concrete slabs were reinforced with a conventional steel-mesh and with polyolefin fibres. This research was focussed on the main aspects affecting the construction. That is to say, the environmental, economic, and social factors were assessed by the method, being of special impact the issues related with maintenance of the structure. The results showed that from the point of view of sustainability, the use of polyolefin fibres provided a significant advantage, mainly due to the lower maintenance required.

Construction involves the use of significant quantities of raw materials and entails high-energy consumption. For the sake of choosing the most appropriate solution that considers environmental and sustainable concepts, tools such as the integrated value model for sustainable assessment (Modelo Integrado de Valor para una Evaluación Sostenible, MIVES) used in Spain, plays a key role in obtaining the best solution. MIVES is a multi-criteria decision-making method based on the value function concept and the seminars delivered by experts. Such tools, in order to show how they may work, require application to case studies. In this paper, two concrete slabs manufactured with differing reinforcements during the construction of the La Canda Tunnels are compared by means of MIVES. The two concrete slabs were reinforced with a conventional steel-mesh and with polyolefin fibres. This research was focussed on the main aspects affecting the construction. That is to say, the environmental, economic, and social factors were assessed by the method, being of special impact the issues related with maintenance of the structure. The results showed that from the point of view of sustainability, the use of polyolefin fibres provided a significant advantage, mainly due to the lower maintenance required.