1,446 research outputs found

    Joint Optimization Framework for Operational Cost Minimization in Green Coverage-Constrained Wireless Networks

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    In this work, we investigate the joint optimization of base station (BS) location, its density, and transmit power allocation to minimize the overall network operational cost required to meet an underlying coverage constraint at each user equipment (UE), which is randomly deployed following the binomial point process (BPP). As this joint optimization problem is nonconvex and combinatorial in nature, we propose a non-trivial solution methodology that effectively decouples it into three individual optimization problems. Firstly, by using the distance distribution of the farthest UE from the BS, we present novel insights on optimal BS location in an optimal sectoring type for a given number of BSs. After that we provide a tight approximation for the optimal transmit power allocation to each BS. Lastly, using the latter two results, the optimal number of BSs that minimize the operational cost is obtained. Also, we have investigated both circular and square field deployments. Numerical results validate the analysis and provide practical insights on optimal BS deployment. We observe that the proposed joint optimization framework, that solves the coverage probability versus operational cost tradeoff, can yield a significant reduction of about 65%65\% in the operational cost as compared to the benchmark fixed allocation scheme.Comment: 30 pages, 15 figures, submitted to IEEE Transactions on Green Communications and Networkin

    Joint Optimal Design for Outage Minimization in DF Relay-assisted Underwater Acoustic Networks

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    This letter minimizes outage probability in a single decode-and-forward (DF) relay-assisted underwater acoustic network (UAN) without direct source-to-destination link availability. Specifically, a joint global-optimal design for relay positioning and allocating power to source and relay is proposed. For analytical insights, a novel low-complexity tight approximation method is also presented. Selected numerical results validate the analysis and quantify the comparative gains achieved using optimal power allocation (PA) and relay placement (RP) strategies.Comment: 5 pages, 2 figures; accepted to IEEE Communications Letters 201

    Effects of Government's Policy in Stock Price: A Case of Nepse

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    The purpose of this study is to find out the relationship of government's policy on the price movement of Nepal stock exchange (NEPSE). This study followed a case study research design, because it offers a deeper perspective and clearer understanding of the stock price movement of Nepalese joint venture banks. The sample size of this study consists of five joint venture commercial Banks, economic analysis and survey reports conducted by central bank of Nepal (Nepal Rastra Bank).The judgmental sampling method has been applied for selection of joint venture banks. The study was totally based on secondary data. in order to make proper analysis descriptive and inferential statistics were used using SPSS software version 26. The finding of this study revealed that the GDP and import are inversely associated with stock price movement and CRR, export, interest rate and inflation are positively associated with stock price movement. Further, it is found that the macroeconomic variables are key factors to determine the Nepalese stock price movement. More importantly, stock market has been found to respond significantly to changes in the government policy. It is recommended that CRR, EXPORT, INTEREST RATE and INFLATION are major factors which largely affect the stock price movement of NEPSE. GDP and IMPORT are not compliance with the stock price movement as they produce negative association with the stocks volatility

    Biogeographical Approaches for Studying Species Invasion

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    Many of the most notorious biological invasions occur at continent-wide or global scales but studies investigating mechanisms enhancing species invasions are often conducted at small spatial scales. Moreover, the contribution of mechanisms facilitating invasion might also vary across a geographical space. I used biogeographical approaches to explore the mechanisms enhancing invasion of introduced genotypes of Phragmites australis along the coastal wetlands of North America. I tested the hypotheses that large-scale disturbance events, such as hurricanes and tropical storms, enhance the invasion success of introduced P. australis in North America. The growth rate of P. australis patches was strongly and positively related to the frequency of hurricane events along the coastal wetlands of the United States. Hurricane frequency alone explained 81% of the variation in the growth rate of P. australis patches over this broad geographical range. I also examined the evolution of latitudinal gradients in native and invasive genotypes of P. australis in relation to plant-herbivore interactions in North America. Common garden experiments revealed that the native and invasive genotypes of P. australis have evolved latitudinal clines on traits associated with herbivory, specifically for aphid Hyalopterus pruni. For a chewing herbivore, Spodoptera frugiperda, only native genotypes exhibited latitudinal clines. The existence of non-parallel latitudinal gradients between native and invasive genotypes creates spatial heterogeneity in the importance of herbivory on P. australis invasion and suggests the greater susceptibility of high-latitude communities. These latitudinal and genotypic variations on plant defenses, palatability, and herbivory suggest a possibility of an asymmetric apparent competition between native and invasive genotypes. A replicated field study in four sites along the Atlantic Coast showed that invasive genotypes could suppress the fitness of native genotypes by herbivore-mediated apparent competition. Moreover, the intensity of apparent competition declined with increasing latitude. These biogeographical studies suggest that multiple processes might be contributing to the spread of the introduced genotypes of P. australis in North America and that the importance of these processes might vary along an environmental gradient. These studies have broader implications for understanding species invasions at the continental scale and for managing natural habitats that are threatened by plant invasions

    Informal settlement segmentation using VHR RGB and height information from UAV imagery: a case study of Nepal

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    Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Geospatial TechnologiesInformal settlement in developing countries are complex. They are contextually and radiometrically very similar to formal settlement. Resolution offered by Remote sensing is not sufficient to capture high variations and feature size in informal settlements in these situations. UAV imageries offers solution with higher resolution. Incorporating UAV image and normalized DSM obtained from UAV provides an opportunity of including information on 3D space. This can be a crucial factor for informal settlement extraction in countries like Nepal. While formal and informal settlements have similar texture, they differ significantly in height. In this regard, we propose segmentation of informal settlement of Nepal using UAV and normalized DSM, against traditional approach of orthophoto only or orthophoto and DSM. Absolute height, normalized DSM(nDSM) and vegetation index from visual band added to 8 bit RGB channels are used to locate informal settlements. Segmentation including nDSM resulted in 6 % increment in Intersection over Union for informal settlements. IoU of 85% for informal settlement is obtained using nDSM trained end to end on Resnet18 based Unet. Use of threshold value had same effect as using absolute height, meaning use of threshold does not alter result from using absolute nDSM. Integration of height as additional band showed better performance over model that trained height separately. Interestingly, benefits of vegetation index is limited to settlements with small huts partly covered with vegetation, which has no or negative effect elsewhere

    Governance Capacity for Climate Adaptation in Nepal

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    For the last few decades global warming has become a strong threat to human development The climate change has been affecting on water resources biodiversity agriculture forestry and public health in specific and the way of life in general Nepal is highly vulnerable to the negative impacts of climate change The crux of the problem for managing climate change adaptation is the rampant poverty In such context this study aims to review the key challenges of climate change governance in Nepal and to determine the extent of the Nepal s climate change governance capacity The primary data for this study was collected by administering a score-sheet to the extensively experienced persons in the field of environment and or climate change This paper concludes that Nepal s climate change governance capacity is of moderate level and marginally improving since 201

    Impact of international trade fairs in export promotion : a case study on Nepalese handicraft products

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    Masteroppgave i bedriftsøkonomi - Universitetet i Nordland, 2011Nepal aggressively liberalized its foreign trade during the 1990s taking the aim to proliferate its market with many countries. Nepal is known as more liberalized country in comparison to other South-Asian nations. This research work is about the impact of International Trade Fairs on the export of Nepalese Handicraft products. This study is based on the handicraft products of Nepal. Handicrafts are third major export item of Nepal. These handicraft products are exhibited in international trade fairs held in different continents of the World. This paper aims to study the effectiveness of international trade fairs as a promotional activity for the expansion of Nepalese handicraft products in international market. It also analyses the emergence of Nepalese trade to gain comparative advantage from its handicraft industry. It also examines the position of the handicraft firms after participating in international trade fairs. It analyzes the potential economic benefits from its handicraft trade and the problems faced by Nepalese handicraft exhibitors while participating in international trade fairs. This research is based upon the data available from 2004 to 2010 so, the analysis part is confined within this period. To analyse the impact of trade fairs precisely, author has taken a case about Nepalese handicraft products. Based upon the articles, journals and research papers from different local and international organisations and the content analysis done by author, this paper suggests that no significant improvements were recorded in the overall productivity growth and spatial distribution of manufacturing which appear to be due mainly to the lack of basic infrastructure and the shortage of skilled manpower. Nepal’s participation in international trade fair is encouraging, but unavailability of proper information and the location, inadequate government support in terms of funding, cooperation, market intelligence, mode of payment for export, inconvenient and long process of selection are some problems that the Nepalese exhibitors are facing in the process of participation in international trade fairs. Nepal’s unrest political insurgency is hindering the overall trade performance so, without solving the biggest problem of peace restoration and state by rule, the potential benefits of liberalization should not be fully achieved

    Supply and demand for cereals in Nepal, 2010–2030:

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    This paper attempts to estimate the future supply and demand for cereals in Nepal. While there has been considerable research in the past examining the agricultural sector in Nepal, to the best of our knowledge there has been no analysis of the supply-demand scenario for food grains in the country. The analysis undertaken in this paper attempts to bridge this gap in the literature by estimating supply and demand models for the three most important cereals in Nepal's food basket: rice, wheat, and maize. The supply projections have been carried out on the basis of a single-crop production function model using data for the period 1995–2008. For estimating the demand function and projecting future demand, data from the Nepal Living Standards Survey II (NLSS II), undertaken in the year 2003/04, are used.cereal supply, cereal demand,

    A Low-Complexity Post-Weighting Predistorter in a mMIMO Transmitter Under Crosstalk

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    In hybrid beamforming, the beam oriented digital predistortion (BO-DPD) is incompetent to linearize the output in different directions except the desired direction to the transmitter. Therefore, subsequent to the BO-DPD operation, we perform a post-weighting (PW) processing to minimize the nonlinear radiations in the wide range of directions. Here, the optimized PW coefficients are multiplied by the polynomial basis functions of the BO-DPD, then, the resultant signals are distributed to the PAs to compensate the nonlinear radiations. In this work, first, we propose fully-featured post-weighting (FF-PW) scheme, then, we derive a low-complexity post-weighting (LC-PW) scheme.Comment: 5 pages, 4 figure

    Thymoma with Myasthenia Gravis in Adolescent

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    Thymomas are exceedingly rare in the first 20 years of life, Thymic lesions comprise approximately 2–3% of all pediatric mediastinal tumors and include thymic cysts, hyperplasia, carcinoma, and thymomas. Fewer than 30 cases in children have been described in the literature. Thymomas in adults are commonly associated with other diseases, the most frequent being myasthenia gravis. However, this association has been rarely reported in childhood. These tumors are typically aggressive, with poor outcomes. We report a case of thymoma associated with myasthenia gravis in a 16-year-old girl and review the literature
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