Community participation should be at the heart of Nepal’s post-earthquake reconstruction

Little progress has been made in reconstruction efforts following the twin earthquakes in Nepal last year. Bishal Chalise writes that a key problem has been the exclusion of the affected communities from the reconstruction process, and argues that giving these groups a voice would help to ensure a more tailored, effective and accountable process. This article forms part of our Nepal Earthquake Anniversary series. Read previous posts here

Wireless Information and Power Transfer in Full-Duplex Systems with Massive Antenna Arrays

We consider a multiuser wireless system with a full-duplex hybrid access point (HAP) that transmits to a set of users in the downlink channel, while receiving data from a set of energy-constrained sensors in the uplink channel. We assume that the HAP is equipped with a massive antenna array, while all users and sensor nodes have a single antenna. We adopt a time-switching protocol where in the first phase, sensors are powered through wireless energy transfer from HAP and HAP estimates the downlink channel of the users. In the second phase, sensors use the harvested energy to transmit to the HAP. The downlink-uplink sum-rate region is obtained by solving downlink sum-rate maximization problem under a constraint on uplink sum-rate. Moreover, assuming perfect and imperfect channel state information, we derive expressions for the achievable uplink and downlink rates in the large-antenna limit and approximate results that hold for any finite number of antennas. Based on these analytical results, we obtain the power-scaling law and analyze the effect of the number of antennas on the cancellation of intra-user interference and the self-interference.Comment: Accepted for the IEEE International Conference on Communications (ICC 2017

Diet of Bengal Tigers (Panthera tigris tigris) in Chitwan National Park, Nepal

We studied the diet of the Bengal tigers (Panthera tigris tigris) in Chitwan National Park, Nepal, by identifying 109 prey items from 85 tiger scats. Tigers in this region fed upon eight different mammal species. Chital (Axis axis) was the major prey with a frequency of 45% of the Tigers’ diet. The occurrence of other prey species included sambar (Cervus unicolor, 23%), wild pig (Sus scrofa, 15%), hog deer (Axis porcinus, 9%), barking deer (Muntiacus muntjak, 4%), and gaur (Bos gaurus, 2%). Tigers also hunted livestock, but this prey comprised a small component of the relative biomass (buffalo 5% and cow 2%). Our study suggests that the tiger depends mostly upon wild prey for its subsistence in the Chitwan National Park, but will also sporadically hunt livestock

Customizable Area Whole Farm Insurance (CAWFI)

The customizable area whole farm insurance (CAWFI) was designed and compared with no insurance program and currently available whole farm insurance based on farm level yield (CFWFI). The CAWFI yields higher certainty equivalents over no insurance program, but lower to CFWFI; CAWFI has fairly small indemnity compared with CFWFI.Agricultural and Food Policy, Crop Production/Industries, Production Economics, Risk and Uncertainty,

If India wants a meaningful place in the Asian Century it must act big and act now

The 1990s saw high and sustained growth for India but this has slowed in recent years. Bishal Chalise writes while that another wave of holistic reforms is required to address structural bottlenecks, India also needs to invest in its human capital and operate closer to the global technology frontier if it wants to become a high-income economy in the long term

Strengthening infrastructure governance in Nepal

The development narrative in Nepal often focusses almost exclusively on how to raise funds for Nepal’s considerable infrastructure needs. Ashutosh Mani Dixit and Bishal K Chalise supplement this with robust framework to ensure resources are used efficiently

Beamforming Optimization for Full-Duplex Wireless-powered MIMO Systems

We propose techniques for optimizing transmit beamforming in a full-duplex multiple-input-multiple-output (MIMO) wireless-powered communication system, which consists of two phases. In the first phase, the wireless-powered mobile station (MS) harvests energy using signals from the base station (BS), whereas in the second phase, both MS and BS communicate to each other in a full-duplex mode. When complete instantaneous channel state information (CSI) is available, the BS beamformer and the time-splitting (TS) parameter of energy harvesting are jointly optimized in order to obtain the BS-MS rate region. The joint optimization problem is non-convex, however, a computationally efficient optimum technique, based upon semidefinite relaxation and line-search, is proposed to solve the problem. A sub-optimum zero-forcing approach is also proposed, in which a closed-form solution of TS parameter is obtained. When only second-order statistics of transmit CSI is available, we propose to maximize the ergodic information rate at the MS, while maintaining the outage probability at the BS below a certain threshold. An upper bound for the outage probability is also derived and an approximate convex optimization framework is proposed for efficiently solving the underlying non-convex problem. Simulations demonstrate the advantages of the proposed methods over the sub-optimum and half-duplex ones.Comment: 14 pages, accepte