In many algorithms for Orthogonal Frequency Division Multiplexing (OFDM) systems, the channel estimation is one of the most essential factors. In wireless environment, channel is change very fast, and the channel has multipath effect, the channel length is obtained by channel estimation. In this paper, we estimation the channel length and the SNR by virtual carriers (VC) and Singular value decomposition, when channel estimator known the information for channel length, then calculate complicated can be reduced. Besides, we proposed the estimated method at carriers frequency offset effect. Noise variance (or noise power) can improve performance of channel estimator, e.g. MMSE channel estimator, turbo code or power allocation. In this paper, we were estimate noise variance by using the blind method of property of orthogonality of matrix, which is differed from the traditional method of Pilots.

Thesis (Ph. D.)--Oregon State University, 2009. / Printout. Includes bibliographical references. Also available on the World Wide Web.

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 260-285).

Thesis (Ph. D.)--University of Hong Kong, 2010. / Includes bibliographical references (leaves 182-203). Also available in print.

Thesis (Ph. D.)--University of Hong Kong, 2010. / Includes bibliographical references (leaves 182-203). Also available online.

Thesis (M.S.)--Ball State University, 2009. / Title from PDF t.p. (viewed on Feb. 08, 2010). Includes bibliographical references (p. 81-94).

Since the 1980s, companies have taken a larger interest in quality and it´s economic impact within the company. Having the knowledge that it´s not quality that costs money, but it´s rather the lack of quality. The work immerses itself in the field of cost of poor quality and the development of key performance indicators. The thesis is performed at Bufab Holding in Värnamo. Bufab Holding is a trading company which mainly buys and sells C-parts. C-parts include fasteners, other small metal-, rubber- or plastic parts such as wires, springs and electronic fasteners. The aim of this thesis was to make a survey of the cost of poor quality and to find key performance indicators (KPI) for cost of poor quality that can be continuously monitored. This work can serve as a basis for other companies within the Bufab group if the company believes that the content of the report can be used. With this aim two issues was created. What is the cost of poor quality that are linked to Bufabs complaints today, and where do they occur? Which key performance indicators can be created, which continuously can be monitored? The work began with a literature study to gain a deeper understanding of the cost of poor quality and the creation of KPI´s. The literature led the writers of this thesis into the methods that were used. Through the data collection, document gathering and given interviews an understanding of the company´s current economic situation. On this basis the company´s claims and processes where analysed with the help of "Seven quality tools". With the help of the piece cost model cost barriers was prepared and the cost of poor quality was calculated. Furthermore KPI´s was created through Lars Sörqvists description of ratio. The cost carriers differed depending on whether it was Bufab who caused the error, if it was a wrong product quality claim or if it was the supplier who caused the error. The cost of poor quality totaled of 4,7 Mkr. The pareto chart shows that the cause wrong product quality caused the highest costs. The costs of poor quality that where calculated mostly consisted of different labor costs. One of the KPI´s was based on labor cost and the other was based on total costs. Furthermore KPI´s where made of the number of complaints with the base of total number of order lines that have been sent. The company can then use this result to show how good quality the company have when new contracts are negotiated. If the methodology and results are promising, this thesis can be a working model for more companies within the Bufab group. Not all visible costs of poor quality was calculated in this thesis due a lack of time. The thesis also lacks entirely an assessment of the hidden costs of poor quality.

A series of experiments have been performed to understand fast electron generation from ultra intense laser-solid interaction, and their transports through a cold material. Using Micro-Electro-Mechanical Systems (MEMS), we contrived various shape of cone and wedge targets. The first set of experiment was for investigating hot electron generations by measuring x-ray production in different energy ranges. K[alpha] and hard x-ray yields were compared when the laser was focused into pyramidal shaped cone targets and wedge shaped targets. Hot electron production is highest in the wedge targets irradiated with transverse polarization, though K[alpha] is maximized with wedge targets and parallel polarization. These results are explained with particle-in-cell (PIC) simulations utilizing PICLS and OOPIC codes. We also investigate hot electron transport in foil, wedge, and cone targets by observing the transition radiation emitted from the targets rear side along with bremsstrahlung x-ray measurement. Twodimensional images and spectra of 800 nm coherent transition radiation (CTR) along with ballistic electron transport analysis have revealed the spatial, temporal, and temperature characteristics of hot electron micro-pulses. Various patterns from different target-laser configurations suggest that hot electrons were guided by the strong static electromagnetic fields at the target boundary. Evidence about fast electron guiding in the cone is also observed. CTR at 400 nm showed that two distinct beams of MeV electrons are emitted from the target rear side at the same time. This measurement indicates that two different mechanisms, namely resonance absorption and j x B heating, create two populations of electrons at the targets front side and drive them to different directions, with distinct temperatures and temporal characteristics. This interpretation is consistent with the results from 3D-PIC code Virtual Laser Plasma Laboratory (VLPL). / text

published_or_final_version / Microbiology / Master / Master of Medical Sciences

published_or_final_version / Microbiology / Master / Master of Medical Sciences