27,813 research outputs found
Coded Modulation Assisted Genetic Algorithm Based Multiuser Detection for CDMA Systems
No full textIn this contribution we propose a novel Coded Modulation assisted Genetic Algorithm based Multiuser Detection (CM-GA-MUD) scheme for synchronous CDMA systems. The performance of the proposed scheme was investigated using Quadrature-Phase-Shift-Keying (QPSK), when communicating over AWGN and narrowband Rayleigh fading channels. When compared with the optimum MUD scheme, the GA-MUD subsystem is capable of reducing the computational complexity significantly. On the other hand, the CM subsystem is capable of obtaining considerable coding gains despite being fed with sub-optimal Information provided by the GA-MUD output
She ji kuan dai jin ling xiang ying chao cai liao zhi ce lüe
No full textNg, Ka Ki = 設計寬帶近零響應超材料之策略 / 吳嘉麒.Thesis M.Phil. Chinese University of Hong Kong 2015.Includes bibliographical references (leaves 107-111).Abstracts also in Chinese.Title from PDF title page (viewed on 29, September, 2016).Ng, Ka Ki = She ji kuan dai jin ling xiang ying chao cai liao zhi ce lüe / Wu Jiaqi
CE Challenges: Work to Do
No full textCE has been used for more than two decades now. Despite many successes and advantages, there are still many challenges to be addressed. These challenges are both technical and organisational. In the paper we will address the current challenges of CE. Many challenges are related to the exchange of data and knowledge and to the systems that make data and knowledge exchange possible. Although much progress has been made in enabling extensive data and knowledge exchange and use, much remains to be wished. For example, there are still barriers to data exchange. Technically, these barriers may consist of different formats, differences in infrastructures and systems, and different semantics. There are also organisational and political barriers. For example, investment in information system may heavily impact upstream suppliers, while revenues of better information exchange may predominantly be gained by downstream actors. Without sharing costs and revenues, chain-wide information exchange will not be easily realised. Another barrier is the possible lack of willingness to share information, because of potential misuse of knowledge and loss of power. The paper is organised as follows. First we will describe the current manifestation of CE as described in a recent book. Second, we will list current trends in CE. Third, we will present some Critical Success Factors (CSFs) that are considered relevant for implementing and adapting CE practices. Last, we indicate some research and practical questions to be addressed, especially for areas that have a high potential and actual impact. </p
Beginning Farmers and Ranchers
No full textUSDA defines beginning farmers and ranchers as those who have operated a farm or ranch for 10 years or less either as a sole operator or with others who have operated a farm or ranch for 10 years or less. Beginning farmers tend to be younger than established farmers and to operate smaller farms or ranches, some of which may provide no annual production. Beginning farmers often face obstacles getting started, including high startup costs and limited availability of land. USDA—through the Farm Service Agency and the Natural Resources Conservation Service—provides loans and conservation assistance to beginning farmers and ranchers. This report draws on data from annual surveys and the Census of Agriculture to provide policymakers with a better understanding of beginning farmers and ranchers, including how they contribute to U.S. agricultural production.agricultural production, Agricultural Resource Management Survey (ARMS), beginning farmers and ranchers, Census of Agriculture, farm assets, Food, Conservation, and Energy Act of 2008, Conservation Reserve Program, operator characteristics, Agricultural and Food Policy, Farm Management,
NG-stack, a temperature proxy for northern Greenland
No full textThe "NG-stack" was calculated by averaging the delta-18O-records of NGT and the NGRIP ice cores in their overlapping time period. Before stacking, all records were centred and normalized regarding their common time window (1505-1953 CE)
Synthesis optimization and charge carrier transfer mechanism in LiLuSiO<sub>4</sub>:Ce, Tm storage phosphor
No full textLiLuSiO4:Ce and LiLuSiO4:Ce, Tm show very efficient charge carrier storage properties upon beta irradiation after samples have received treatment in vacuum. They outperform the commercial storage phosphor BaFBr(I):Eu2+ in many aspects. The influence of the synthesis conditions, Ce and Tm concentration, nonstoichiometry and codoping with Ca, Hf, Al and Ge are reported. Based on the results of the synthesis optimization, thermoluminescence (TL) emission and TL excitation spectra a mechanism of charge carrier transfer, storage, and recombination during irradiation and thermal or optical readout is proposed.Accepted Author ManuscriptRST/Fundamental Aspects of Materials and EnergyRST/Luminescence Material
Threefold Divisorial Contractions to Singularities of cE Type
No full text極小模型理論是雙有理幾何的一個有力工具。為了更清楚暸解三維多樣體的幾何學，我們希望利用明確極小模型理論對三維多樣體進行明確分類，其中「明確」（explicit）指的是透過對具體方程式的研究以得到更細緻的結論。而divisorial contractions、flips和flops被視為極小模型理論中的初等雙有理映射，對它們的認識將有助加深我們對三維幾何學的瞭解。
在這裡我們會著眼於divisorial contractions，亦即因子收縮映射。由[Kwk05]我們知道把因子收縮到指標大於1的點的因子收縮映射皆可以寫成一個加權blowup。我們猜想把因子收縮到指標是1的點的因子收縮映射也都可以寫成一個加權blowup。
本文探討把因子收縮到cE型奇異點而且discrepancy為1的因子收縮映射。我們將會整理並介紹早川貴之（Takayuki Hayakawa）的工作[HayP2]。特別地，在discrepancy 1的假設下，我們可以對cE型奇異點引入適當的結構，使得在建構因子收縮映射時對cE型奇異點有較好的分類。最後，我們按照前述cE型奇異點的分類建構出一些因子收縮映射，從而部分地驗證我們的猜想。The minimal model program (MMP) has long been a powerful tool in birational geometry. In order to know more about the geometry in dimension 3, we hope to develop an explicit classification of threefolds by using the MMP explicitly. By explicit we mean the study concerns concrete equations so as to gain more details. Note that divisorial contractions, flips and flops are considered elementary birational maps in the MMP. Having some explicit awareness about these birational maps allows us to have a better understanding of threefolds.
Here we intend to study divisorial contractions. It is known that a divisorial contraction to a point of index greater than 1 can be realized as some weighted blowup ([Kwk05]). We conjecture that the statement is also true for points of index 1; that is, every divisorial contraction to a point of index 1 can also be realized as a weighted blowup.
This thesis considers divisorial contractions to cE points with discrepancy 1. We will survey the work [HayP2] of Hayakawa. In particular, certain structure will be introduced to cE singularities so that we would have a better classification for constructing or studying the divisorial contractions. Finally, we construct some divisorial contractions according to that classification of cE points in order to partially examine our conjecture.Thesis Approval Form (i)
Acknowledgements (ii)
Abstract in Chinese (iii)
Abstract in English (iv)
Chapter 1. Introduction (1)
Chapter 2. Normal Forms of cE Singularities (3)
Chapter 3. Constructing Weighted Blowups via Toric Method (5)
3.1. Hyperquotient Singularities (5)
3.2. Weighted Blowups (6)
Chapter 4. Admissible Weights and Canonical Forms (10)
4.1. Discrepancy 1 and Admissible Weights (10)
4.2. Levels and Stages of a Normal Form (12)
Chapter 5. Admissible Weighted Blowups (15)
5.1. General Properties (15)
5.2. With Weights in Stage 0 (19)
5.3. With Weights in Stage 1 (21)
Chapter 6. Divisorial Contractions with Discrepancy 1 (22)
6.1. To cE Singularities of Level 6 (22)
6.2. To cE Singularities of Level 5 (25)
6.3. To cE Singularities of Level 4 (25)
6.4. A Comment about cE Points of Lower Levels (28)
Bibliography (30
Rent-Seeking in Developed and Developing Countries: Cross Section and Time Series Studies
No full textThe property rights issue is one of the most important institutional differences between developed/developing countries. The violation of the property rights results with rentseeking. In order to see if the extent of rent-seeking differs significantly between developed and developing countries, I applied a cross section and a time series study with the intention to measure rent-seeking. I found that rent-seeking is low in developed countries whilst it is high in developing counterparts. Turkey, as a developing country was my special case to apply time series study to see if rentseeking vary over the years. In my additional work for Turkey, I found that there is a cointegrating relationship between rent- seeking as a percentage of the budget LnRt and government size ( LnGYt ), and GNP per capita income ( LnGNPCt ).Rent-Seeking; Budgetary Allocation; Cross Section Study; Time Series Study
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