Uppsala University

About: Uppsala University is a education organization based out in Uppsala, Sweden. It is known for research contribution in the topics: Population & Gene. The organization has 36485 authors who have published 107509 publications receiving 4220668 citations. The organization is also known as: Uppsala universitet & uu.se.

Space-Time Block Coding for Wireless Communications

Abstract: Space-time coding is a technique that promises greatly improved performance in wireless networks by using multiple antennas at the transmitter and receiver. Space-Time Block Coding for Wireless Communications is an introduction to the theory of this technology. The authors develop the topic using a unified framework and cover a variety of topics ranging from information theory to performance analysis and state-of-the-art space-time coding methods for both flat and frequency-selective fading multiple-antenna channels. The authors concentrate on key principles rather than specific practical applications, and present the material in a concise and accessible manner. Their treatment reviews the fundamental aspects of multiple-input, multiple output communication theory, and guides the reader through a number of topics at the forefront of current research and development. The book includes homework exercises and is aimed at graduate students and researchers working on wireless communications, as well as practitioners in the wireless industry.

Characteristic chromosomal abnormalities in biopsies and lymphoid‐cell lines from patients with burkitt and non‐burkitt lymphomas

Abstract: The karyotypes of cells from 10 Burkitt lymphoma (BL) biopsies, eight cell lines established from BL and nine cell lines from non-BL sources were studied by chromosome banding techniques. With the exception of the BL-derived cell lines BJAB, GC-BJAB, Maku and U-8691 all biopsies and lines of Burkitt origin contained an extra band at the distal region of the long arm of one chromosome 14. An extra band on chromosome 14 was also found in cells of one non-BL biopsy, in cells from a lymphosarcoma-derived cell line and in a long-established cell line derived from the pleural exudate of a patient with Hodgkin's disease. A distal region at the long arm of one chromosome 8 was missing in all metaphase figures of good technical quality in the same material. The size, morphology and stain-ability of the missing region corresponded fairly well to the extra region at chromosome 14. We therefore suggest that the chromosome 14 marker represents a translocation between chromosomes 8 and 14,t (8q-; 14q+). The translocation was present neither in lymphocytes of the peripheral blood of five Burkitt patients nor in five lymphoblastoid cell lines of non-BL origin. Trisomy 7 was found in two of the 10 BL biopsies, in two BL-derived cell lines, in one non-BL biopsy, in two lymphosarcoma-derived cell lines and in one cell line derived from a patient with Hodgkin's disease.

MaltParser: A language-independent system for data-driven dependency parsing

Abstract: Parsing unrestricted text is useful for many language technology applications but requires parsing methods that are both robust and efficient. MaltParser is a language-independent system for data-driven dependency parsing that can be used to induce a parser for a new language from a treebank sample in a simple yet flexible manner. Experimental evaluation confirms that MaltParser can achieve robust, efficient and accurate parsing for a wide range of languages without language-specific enhancements and with rather limited amounts of training data.

Dye-sensitized solar cells for efficient power generation under ambient lighting

Abstract: Solar cells that operate efficiently under indoor lighting are of great practical interest as they can serve as electric power sources for portable electronics and devices for wireless sensor networks or the Internet of Things. Here, we demonstrate a dye-sensitized solar cell (DSC) that achieves very high power-conversion efficiencies (PCEs) under ambient light conditions. Our photosystem combines two judiciously designed sensitizers, coded D35 and XY1, with the copper complex Cu(II/I)(tmby) as a redox shuttle (tmby, 4,4′,6,6′-tetramethyl-2,2′-bipyridine), and features a high open-circuit photovoltage of 1.1 V. The DSC achieves an external quantum efficiency for photocurrent generation that exceeds 90% across the whole visible domain from 400 to 650 nm, and achieves power outputs of 15.6 and 88.5 μW cm–2 at 200 and 1,000 lux, respectively, under illumination from a model Osram 930 warm-white fluorescent light tube. This translates into a PCE of 28.9%. A dye-sensitized solar cell that has been designed for efficient operation under indoor lighting could offer a convenient means for powering the Internet of Things.