A Low-Complexity Precoding Scheme for the Downlink of Multi-Cell Multi-User MIMO AF System

Because of its simplicity, amplify-and-forward (AF) is one of the most popular cooperative relaying technique. Relays are used in cooperative communication to improve reliability, coverage or spectral efficiency of cell-edge users. However, relays tend to increase the interferences seen by users of adjacent cells, particularly by the cell-edge users, when used in multi-cell systems. In this paper, we propose a low-complexity precoding scheme to mitigate the effect of other-cell interference (OCI) in cooperative communication. The scheme is designed by taking into account the interference plus noise covariance matrix of each user for mitigating the interference at each receiver by means of precoding at the relay node. Simulation results show the effectiveness of the proposed scheme, both in terms of sum-rate and computational complexity, when compared to other existing OCI-aware precoding algorithms for AF

Effect of Vegetative Propagation Materials on Globe Artichoke Production in Semi-Arid Developing Countries: Agronomic, Marketable and Qualitative Traits

Abstract: In Tunisia, globe artichoke is mainly propagated by underground dormant axillary buds (ovoli), which are removed from the field in August during the quiescence period. The high cost of in vitro-plants and the absence of specialized nurseries were among the reasons for the rise of heterogeneity and spread of diseases. The aim was to help farmers to improve artichoke yield and quality by ameliorating their vegetative propagation technique with low cost methods. Three plant cuttings management methods were tested: summer ovoli (T0); spring offshoots nursery\u2019s cuttings forced to pass a vegetative rest period by stopping irrigation (T1); and offshoots nursery\u2019s cuttings not forced (T2). The cuttings management can affect both yield and qualitative traits of artichoke. T1 nursery plants produced the heaviest primary heads, 7% and 23% higher than T2 and T0, respectively. T1 plants exhibited the highest yield during the harvest season, with +17.7% and +12.2% compared to T0 and T2, respectively. T0 and T1 showed the highest total antioxidant capacity and inulin content; the propagation method also affected the short-chain sugars ratio. T1 is a viable and sustainable alternative to the traditional one that does not heavily impact on growing costs and improves yield and quality of artichoke

Expanding cellular coverage via cell-edge deployment in heterogeneous networks: spectral efficiency and backhaul power consumption perspectives

Heterogeneous small-cell networks (HetNets) are considered to be a standard part of future mobile networks where operator/consumer deployed small-cells, such as femtocells, relays, and distributed antennas (DAs), complement the existing macrocell infrastructure. This article proposes the need-oriented deployment of smallcells and device-to-device (D2D) communication around the edge of the macrocell such that the small-cell base stations (SBSs) and D2D communication serve the cell-edge mobile users, thereby expanding the network coverage and capacity. In this context, we present competitive network configurations, namely, femto-on-edge, DA-onedge, relay-on-edge, and D2D-communication on- edge, where femto base stations, DA elements, relay base stations, and D2D communication, respectively, are deployed around the edge of the macrocell. The proposed deployments ensure performance gains in the network in terms of spectral efficiency and power consumption by facilitating the cell-edge mobile users with small-cells and D2D communication. In order to calibrate the impact of power consumption on system performance and network topology, this article discusses the detailed breakdown of the end-to-end power consumption, which includes backhaul, access, and aggregation network power consumptions. Several comparative simulation results quantify the improvements in spectral efficiency and power consumption of the D2D-communication-onedge configuration to establish a greener network over the other competitive configurations

Free primary health care for vulnerable social groups in low income settings : lessons from Malawi and Zambia

Due to the increased burden of poor health on poor and rural households, Malawi and Zambia waived user fees in health. Malawi introduced an Essential Health Package (EHP) in 2004 to address common causes of morbidity and mortality that disproportionately affect the poor. Zambia abolished user fees in health for rural households in 2006. Waving user fees was seen as an effective tool for bridging the socio-economic divide and improving health equity. These policies sought to reduce the national health burden, which falls more heavily on poor and rural households. Against this back drop, this study was formulated to review literature on the effects of the stated policies on access to health services by vulnerable social groups in both nations and investigate the challenges that constrain their implementation. The study focused on social protection in health for vulnerable groups using a social constructionist approach. The review found that access and utilization of health services have significantly improved in both cases. However, coverage of services is still limited. Services are free in principle but poor households still have to bear indirect costs to health services. Health centers and personnel are still disproportionately distributed between urban and rural areas and structural factors still threaten household accessibility to services. The analysis also finds the targeting strategies used in delivering services inadequate. Thus, both countries have not effectively extending coverage of services. Overall, Malawi’s EHP has produced better coverage than the Zambian waiver policy due to more coordinated implementation. However, the understanding of what the policies entail on the part of health managers at facility level is in both cases weak thus compromising implementation. Although intended to be supply-side both policies are in practice demand-side. Both nations suffer human resource and essential medicine shortages, poor distribution of health facilities and poor funding and coordination. Hence, health systems should be strengthened and remote areas targeted more. Both governments should increase social protection budgets. Donors should pool support to reduce coordination problems in implementation and a quasi-internal market in health care with a system of purchasers and providers of services should be introduced. Further inquiry on social impacts of the policies and not only cost effectiveness is necessary.Master in International Social Welfare and Health Polic

Agro-Industry and Smallholder Agriculture: Institutional Arrangements and Rural Poverty Reduction in Mozambique

Resultados das investigações do Departamento de Análise de Políticas MADER - Direcção de Economíafood security, food policy, Mozambique, agroindustrial, smallholder agriculture, Agribusiness, Q18,

PERSEPSI TOKOH ADAT KOTA SUBULUSSALAM TERHADAP PEMBENTUKAN LEMBAGA WALI NANGGROE

Sejak pembentukan Lembaga Wali Nanggroe, menimbulkan beragam persepsi baik yang pro dan kontra dikalangan tokoh adat, tidak terkecuali dikalangan tokoh adat Kota Subulussalam. Sejak pembentukan Wali Nanggroe tentunya ada yang menjadi permasalahan berupa persepsi tokoh adat yang pro dan kontra terhadap Lembaga Wali Nanggroe di daerah Kota Subulussalam. Tujuan penelitian ini untuk mengetahui persepsi tokoh adat Kota Subulussalam terhadap pembentukan Lembaga Wali Nanggroe, serta untuk mengetahui perbedaan persepsi tokoh adat Kota Subulussalam. Teknik pengumpulan data yang digunakan yaitu penelitian lapangan dan penelitian kepustakaan. Penelitian lapangan adalah untuk memperoleh data primer yang dilakukan dengan wawancara dan observasi, sedangkan penelitian kepustakaan adalah untuk memperoleh data sekunder dengan cara membaca buku referensi, peraturan perundang-undangan, dan bahan bacaan lainnya yang berkaitan dengan penelitian ini. Hasil penelitian menunjukkan bahwa persepsi tokoh adat Kota Subulussalam terhadap pembentukan Lembaga Wali Nanggroe menimbulkan pro dan kontra, penyebab pro dan kontra dikalangan tokoh adat dikarenakan tidak adanya sosialisasi perihal Wali Nanggroe, sebagian tokoh adat juga tidak merespon adanya Wali Nanggroe dan sebagian tokoh adat tidak mengetahui tugas dan fungsi Lembaga Wali Nanggroe. Disarankan sabaiknya Lembaga Wali Nanggroe disosialisasikan terlebih dahulu, setiap tokoh adat juga diikut sertakan dalam urusan Lembaga Wali Nanggroe, pemangku Lembaga Wali Nanggroe juga aktif melakukan pendekatan-pendekatan sosial ke setiap daerah Provinsi Aceh agar Wali Nanggroe terealisasikan dengan baik

Electromagnetic emission-aware schedulers for the uplink of OFDM wireless communication systems

The popularity and convergence of wireless communications have resulted in continuous network upgrades in order to support the increasing demand for bandwidth. However, given that wireless communication systems operate on radiofrequency waves, the health effects of electromagnetic emission from these systems are increasingly becoming a concern due to the ubiquity of mobile communication devices. In order to address these concerns, we propose two schemes (offline and online) for minimizing the EM emission of users in the uplink of OFDM systems, while maintaining an acceptable quality of service. We formulate our offline EM reduction scheme as a convex optimization problem and solve it through water-filling. This is based on the assumption that the long-term channel state information of all the users is known. Given that, in practice, long-term channel state information of all the users cannot always be available, we propose our online EM emission reduction scheme, which is based on minimizing the instantaneous transmit energy per bit of each user. Simulation results show that both our proposed schemes significantly minimize the EM emission when compared to the benchmark classic greedy spectral efficiency based scheme and an energy efficiency based scheme. Furthermore, our offline scheme proves to be very robust against channel prediction errors

A User Scheduling Scheme for Reducing Electromagnetic (EM) Emission in the Uplink of Mobile Communication Systems

The ubiquity and convergence of wireless communication services have contributed to an unprecedented popularity of mobile communications. Given that wireless communication systems operate on radiofrequency waves, the electromagnetic (EM) radiation exposure they generate is also unprecedented and, hence, this could have adverse health effects on both humans and animals according to the World Health Organization. In this paper, we propose a user scheduling/power allocation scheme to minimize the EM exposure of users subject to transmitting a target number of bits. Our user scheduling method is based on assigning priority levels to each user and the user with the lowest priority level is scheduled for transmission. Power allocation, on the other hand, is based on the water-filling approach over time by using the past channel gains of a user to compute its water level. Simulation results show that our proposed scheme performs much better than a spectral efficiency based scheme but has a higher EM emission in comparison with a non-practical ideal scheme

A survey and tutorial of electromagnetic radiation and reduction in mobile communication systems

This paper provides a survey and tutorial of electromagnetic (EM) radiation exposure and reduction in mobile communication systems. EM radiation exposure has received a fair share of interest in the literature; however, this work is one of the first to compile the most interesting results and ideas related to EM exposure in mobile communication systems and present possible ways of reducing it. We provide a comprehensive survey of existing literature and also offer a tutorial on the dosimetry, metrics, international projects as well as guidelines and limits on the exposure from EM radiation in mobile communication systems. Based on this survey and given that EM radiation exposure is closely linked with specific absorption rate (SAR) and transmit power usage, we propose possible techniques for reducing EM radiation exposure in mobile communication systems by exploring known concepts related to SAR and transmit power reduction in mobile systems. Thus, this paper serves as an introductory guide to EM radiation exposure in mobile communication systems and provides insights toward the design of future low-EM exposure mobile communication networks