Das TU-Kooperationszentrum für Katastrophen-vorbeugung und Sicherheit in Bauten

The Cooperation Center for Disaster Mitigation and Security in Buildings as an interdisciplinary academic facility of the Vienna University of Technology (VUT) aims at the goal to carry out “research for the benefit of mankind”. It takes place in the framework of practice oriented and society relevant research projects of complex quality, which require a close cooperation between the various disciplines. Because of the increasing number of hazards caused by the violating forces of nature the Vienna University of Technology has made research driven education a new focal point for students of the Department of Architecture in cooperation with experts of disaster mitigation. By means of an agreement and through joint projects in cooperation with the University of Tokyo, since 1981 the Vienna University of Technology has had a close relation with Japan, which similarly to Austria is a natural hazard prone country. The so-called Key Station of the VUT plays an important role by continuously maintaining the prerequisites of scientific cooperation with Japan and by directing research activities, as well. An actual theme is the Niigata-Project, which will be carried out in the framework of the official program “Japan — EU Year of People-to-People Exchanges 2005” on the occasion of the disastrous earthquake in Japan 2004. Some of the disaster mitigation projects on the fields earthquake, tsunami, flood, avalanche and landslide carried out by students of the VUT are presented.     

Channel Estimation Method for OFDM in Low SNR Based on Two-dimensional Spreading

In this paper, we present a channel estimation method based on two-dimensional signal spreading applicable to orthogonal frequency multiple access multicarrier systems. Our method exploits a spreading of a transmitted data signal as well as a pilot signal over the assigned frequency range and time period. As a spreading sequence we exploited orthogonal Walsh–Hadamard sequences. When compared with traditional pilot symbol based channel estimation, our method is beneficial in low signal to noise ratio (SNR). For a comparison of our method with state-of-the-art channel estimation method, we utilized an open source LTE downlink simulator developed at TU Vienna. This enables a reproducibility of our results. Considering the LTE system, our method outperforms the traditional approach in typical range of SNR from \(-\) 5 to 10 dB. For a comparison of a throughput performance, a number of channel models has been employed.     

Radar und Radiometer-wichtige Hilfsmittel für die Wellen-ausbreitungsforschung, Niederschlagsmessung und Naturgefahrenfrüherkennung

This paper gives an overview on research and development projects carried out by the Radar and Propagation Research Group (at INW/TU Graz and IAS/Joanneum Research) during the last 26 years. Starting off from the original objective, i.e. research regarding the influence of tropospheric precipitation on communications satellite signal propagation, the reported activities span up to the utilization of created tools and abilities for purposes of meteorology, hydrology and natural hazards early detection and warning.     

Rough mode cost–based fast intra coding for high-efficiency video coding

The quadtree-based coding unit (CU) and transform unit (TU) structure, as well as various prediction units (PUs) of HEVC, considerably increase encoding complexity in intra coding and inter coding. This paper proposes a rough mode cost (RMC)-based algorithm for accelerating CU/TU depth decisions and PU mode decisions in HEVC intra coding. For CU depth decisions, RMC values are used for the fast determination of CU partition. In the case of PU mode decisions, modes with higher RMCs are removed from the candidate list to reduce the number of test modes. For TU depth decisions, the TU partition of the mode with the least RMC is used to determine the TU partitions of remaining modes. The proposed TU partitioning method demonstrates superior performance to the default method in reference software. The proposed algorithm can reduce encoding time by approximately 51% on average, with a 0.69% increase in the Bjøntegaard-Delta (BD) rate.     

Highly sensitive wide-dynamic range optical burst-mode receivers for ultra fast gain switching

Highly sensitive optical receivers in BiCMOS, sub-micron and deep-sub-micron CMOS technology are compared. Special attention is paid to burst-mode receivers with a wide-dynamic input range and with fast gain switching. A new burst-mode receiver design in 0.12μm CMOS technology for a data rate of 2.5 Gb/s and very fast gain switching is presented. Handling a wide dynamic range leads to stability problems when the transimpedance gain of the preamplifier is decreased. These stability problems could be solved by decreasing the open-loop gain of the transimpedance amplifier. Stability analysis of this solution is presented here. Kerstin Schneider was born in St. Poelten, Austria, on February 15, 1975. She received the Dipl. Ing. degree from the Vienna University of Technology, Austria, in 2000. In 2004 she received her Dr. techn. degree at the Vienna University of Technology, Austria. Since 2001 she is with the Vienna University of Technology, Institute for Electrical Measurements and Circuit Design, Vienna, Austria. She is author of the Springer book ‘Highly Sensitive Optical Receivers’. Her major fields of interest are optoelectronics and integrated circuit design. Horst Zimmermann (M’98–SM’02) born in Sulzbach-Rosenberg, Bavaria, on 27 December 1957 studied Physics in Bayreuth, Germany, and received the Dr.-Ing. degree in the Fraunhofer Institute for Integrated Circuits (IIS-B), Erlangen, Germany in 1991. Then, Dr. Zimmermann was an Alexander-von-Humboldt Research-Fellow at Duke University, Durham, N.C., where he worked on diffusion in Si, GaAs, and InP until 1992. In 1993, he joined the Chair for Semiconductor Electronics at Kiel University, where he lectured optoelectronics and worked on optoelectronic integration. Since 2000 he is professor for Electronic Circuit Design at the Vienna University of Technology, Vienna, Austria. His main interests are in design and characterization of analog deep-sub-micron CMOS circuits and optoelectronic integrated CMOS and BiCMOS circuits. He is author of the Springer books ‘Integrated Silicon Optoelectronics’ and ‘Silicon Optoelectronic Integrated Circuits’ and co-author of ‘Highly Sensitive Optical Receivers’ as well as author and co-author of more than 140 publications.     

基于自适应深度预测的快速变换单元判决算法

新一代视频编码标准HEVC相比之前标准,在提升编码效率的同时显著增加计算复杂度。针对这一问题,本文提出了一种基于自适应深度预测的快速变换单元(TU)判决算法,利用残差四叉树(RQT)深度自身分布特点以及时空相邻RQT最大深度的相关性预测不同尺寸编码单元(CU)的RQT深度,跳过不必要的深度计算。仿真结果表明,在标准编码配置条件下,相比全部深度判决方法,本算法在保证编码效果的前提下,平均降低50%的TU运算时间,极大减少计算复杂度;同时相比于同类算法在处理复杂序列时的低效率,本算法很好地解决了此类问题。     

两路STM-1开销和支路净荷处理的设计实现

利用低成本的FPGA实现两路STM-1开销和TU3/TU12支路净荷处理,同时利用FPGA内嵌的PLL产生155m线路时钟和77M参考时钟,以满足系统对时序的要求.设计支持19m和77m两种Telecom bus总线接口,支持TU3/TU12或混合模式的净荷处理.     

Identification of the impurity phase in chemically deposited CdS thin films

Identification of the impurity phase present in chemically deposited CdS thin films and in the precipitate used for screen printing CdS/CdTe solar cells is reported in this paper. X-ray diffraction (XRD) studies of the films and the precipitate showed that the impurity phase is a mixture of cadmium oxide sulphate (Cd₃O₂SO₄) and cadmium oxide (CdO). Analysis of the films and the powders obtained using thiourea (TU) and thioacetamide (TA) as sulphursing agents showed that the impurity phase is predominantly present when TU is used in the chemical bath. The high conductivity shown by chemically deposited CdS films (using TU) when annealed at higher temperatures in air is attributed to the predominance of the conducting CdO phase in the film.     

Zugsicherungstechnik bei der Wiener U-Bahn

For the second building stage of the Vienna subway with the lines U3 and U6 whose first plants went in operation in September 1988, the conceptions for the signal installations and the train protection were to be determined on time. Numerous innovations are to be recorded although one could not yet then decide for computer-controlled interlocking systems nevertheless compared to the plants in the subway ground net, as the modular interlocking system (MSU) developed especially for the Vienna subway, the electronic LZB devices LZB 513, simulation with the system TRANSIT, remote control of the interlocking stations with the computer-controlled system Command 900 as well as integration of the proved computer-controlled train guidance system BLW. The report consequently contains the outfit state of the last decade on the sector train control system plants at the Vienna subway with view onto the outfit of the new lines.     

Resource allocation scheme for orthogonal frequency division multiple access networks based on cooperative game theory

Cooperative game theory can be applied to orthogonal frequency division multiple access (OFDMA) networks for fair resource allocation. In this work, we consider a comprehensive cross‐layer framework including physical and medium access control layer requirements. We apply two cooperative games, nontransferable utility (NTU) game and transferable utility (TU) game, to provide fairness in OFDMA networks. In NTU game, fairness is achieved by defining appropriate objective function, whereas in TU game, fairness is provided by forming the appropriate network structure. For NTU game, we analyze the Nash bargaining solution as a solution of NTU game taking into account channel state information and queue state information. In a TU game, we show that coalition among subcarriers to jointly provide rate requirements leads to better performance in terms of power consumption. The subcarrier's payoff is determined according to the amount of payoff which that subcarrier brings to the coalition by its participation. We show that although NTU and TU games are modeled as rate adaptive and margin adaptive problems, respectively, both solutions provide a fair distribution of resources with minimum fairness index of 0.8. Copyright © 2012 John Wiley & Sons, Ltd.     

50 Jahre Kybernetik in Österreich

The term “cybernetics” is very old, but in the middle of the last century it gained new importance as steering brought new aspects to the area of information technology. This paper deals with the general history of cybernetics and then describes the beginning of this field at Vienna University of Technology. In this context it was an important step, when the book “Cybernetics” by Norbert Wiener first came to Vienna; thus the interest in cybernetic models evolved. Originating from the interest in cybernetic models, three models were recreated (and refined):

1. the model of the conditioned reflex (artificial tortoise),
2. the model of orientation in a maze (mouse), and
3. the model of homeostasis (homeostat).

The third and final part of this paper illustrates the gradual transition to artificial intelligence (AI). Hopes that were tied up with this term are discussed. Apart from that the question of how much has been left of cybernetics and artificial intelligence today is raised. The mouse in the maze is very closely connected to our Emeritus: He built the Viennese version of it as part of his diploma thesis.     

Effective capacity of a correlated Rayleigh fading channel

The next generation wireless networks call for quality of service (QoS) support. The effective capacity (EC) proposed by Wu and Negi provides a powerful tool for the design of QoS provisioning mechanisms. In their previous work, Wu and Negi derived a formula for effective capacity of a Rayleigh fading channel with arbitrary Doppler spectrum. However, their paper did not provide simulation results to verify the accuracy of the EC formula derived in their paper. This is due to difficulty in simulating a Rayleigh fading channel with a Doppler spectrum of continuous frequency, required by the EC formula. To address this difficulty, we develop a verification methodology based on a new discrete‐frequency EC formula; different from the EC formula developed by Wu and Negi, our new discrete‐frequency EC formula can be used in practice. Through simulation, we verify that the EC formula developed by Wu and Negi is accurate. Furthermore, to facilitate the application of the EC theory to the design of practical QoS provisioning mechanisms in wireless networks, we propose a spectral‐estimation‐based algorithm to estimate the EC function, given channel measurements; we also analyze the effect of spectral estimation error on the accuracy of EC estimation. Simulation results show that our proposed spectral‐estimation‐based EC estimation algorithm is accurate, indicating the excellent practicality of our algorithm. Copyright © 2010 John Wiley & Sons, Ltd.     

Biography - Ernst Weber

Dr. Weber was born in Vienna, Austria, on September 6, 1901, and received all his education there. He was graduated with the diploma of Electrical Engineer from the Technical University in Vienna in 1924, and joined the Austrian Siemens-Schuckert Company as research engineer. On the basis of several papers on field theory applied to machinery, he received the degree of Sc.D. from the Technical University in Vienna in 1927.     

基于统计建模的VVC快速码率估计算法

为降低新一代通用视频编码（versatilevideocoding,VVC）标准率失真优化过程的编码复杂度,提出一种基于统计建模的快速码率估计算法。首先,算法充分考虑依赖性量化（dependent quantization,DQ）的量化行为和熵编码中的上下文依赖,提出可以准确刻画编码过程中上下文状态迁移的码率特征,初步预估变换单元（transformunit,TU）中部分语法元素的码率;其次,基于系数分布特性,定义系数混乱度特征和稀疏度特征来区分系数分布差异带来的码率影响,并构建TU级码率模型;最后,算法根据码率构成特性将大尺寸TU和小尺寸TU分开建模实现更精准的码率预估。通过统计方式对大量样本进行回归训练,得到最终的线性码率模型,并应用于VVC的模式决策中。实验结果表明,所提出算法在随机访问（random access,RA）配置下,可以实现16.289%的复杂度降低,而码率变化率（Bjontegaard delta bit rate,BD-BR）仅增加1.567%。     

SDH系统中去同步器泄漏率算法的研究

介绍了一种SDH系统中去同步器的比特泄漏率算法,该算法适用于基于相位扩散技术的去同步器。它监测TU指针调整计数器,根据指针调整的速度,在不同的区间采用不同的算法,使得输出的E1接口指标完全达到ITU-T相关标准要求,而且占用CPU较少的资源,具有一定的先进性。     

Dual Effects of Slow Recrystallization and Defects Passivation Achieve Efficient Tin-Based Perovskite Solar Cells with Good Stability Up to One Year

Tin-based perovskite solar cells (TPSCs) have become a star candidate in lead-free perovskite cells due to their excellent optoelectronic properties and low toxicity. However, there are a lot of problems such as uncontrollable crystallizationprocess, easy oxidation of Sn²⁺ and high defect density have not been completely resolved in TPSCs. Here, the thiourea (TU) and amidine thiourea (ASU) are added into the perovskite precursor to regulate the microstructure, inhibit the oxidation of Sn²⁺ and promote charge transfer. The characterization results demonstrate that the TU additive can not only improve the micrograph, crystallinity and antioxidant, but also significantly induce recrystallization and passivate trap states. Thus, the TPSCs with TU (TU-modified TPSCs) show a significantly higher power conversion efficienc (PCE) and better stability than those of the TPSCs with ASU (ASU-modified PSCs) and reference TPSCs. After stored in N₂ atmosphere for 8 months, the unencapsulated TU-modified PSCs achieve a champion PCE of 10.9% with an open-circuit voltage of 0.79 V. Furthermore, the unsealed TU-modified PSCs can maintain 115% of its initial efficiency after stored in N₂ atmosphere for one year. This is the longest lifetime of unencapsulated pure TPSCs in N₂ atmosphere.     

The expanding world of R&D

How various countries and companies are attempting to maintain their competitive positions in an increasingly Japanese-dominated climate is examined. The role of government in supporting research, technology, and their applications (which varies widely among countries) is discussed. Unlike the US, other countries gear their roles to helping their citizens gain advantage in the commercial marketplace. In Japan, emphasis is on transferring ideas to the marketplace; efforts by companies are coordinated by a variety of organizations led by the Ministry of International Trade and Industry. A cornerstone of R&D efforts in the European Community (EC) is the European Strategic Program for Research and Development in Information Technology (ESPRIT). As of the end of 1989, more than 150 ESPRIT projects contributed directly to new products or services; nearly 120 resulted in tools and methods used outside the ESPRIT community; and more than 40 contributed to international standards. Research spending by major corporations is recounted, with big spenders being found in every part of the world. Ways to assess a country's commitment to R&D are described, and the growing role of international cooperation is addressed     

DC-free error-control block codes

DC-free codes and error-control (EC) codes are widely used in digital transmission and storage systems. To improve system performance in terms of code rate, bit-error rate (BER), and low-frequency suppression, and to provide a flexible tradeoff between these parameters, this paper introduces a new class of codes with both dc-control and EC capability. The new codes integrate dc-free encoding and EC encoding, and are decoded by first applying standard EC decoding techniques prior to dc-free decoding, thereby avoiding the drawbacks that arise when dc-free decoding precedes EC decoding. The dc-free code property is introduced into standard EC codes through multimode coding techniques, at the cost of minor loss in BER performance on the additive white Gaussian noise channel, and some increase in implementation complexity, particularly at the encoder. This paper demonstrates that a wide variety of EC block codes can be integrated into this dc-free coding structure, including binary cyclic codes, binary primitive BCH codes, Reed-Solomon codes, Reed-Muller codes, and some capacity-approaching EC block codes, such as low-density parity-check codes and product codes with iterative decoding. Performance of the new dc-free EC block codes is presented.     

Vienna整流器单周控制技术研究

通过分析三相三开关三电平(Vienna)整流器的工作原理,研究了该整流器的单周控制策略,并采用电压外环和电流内环的双闭环控制,实现了Vienna整流器的可靠稳定、低谐波畸变特性。基于Matlab仿真平台,搭建了Vienna整流器的仿真模型,仿真结果表明,基于单周控制方法的8 kW三相PFC整流器,控制结构简单,系统可靠稳定,谐波畸变率＜3%,功率因数可达99%。     

从WAP的应用看移动因特网的发展

ＷＡＰ技术的开发与应用揭开了移动因特网发展的崭新一页,据预测,到２００４年亚太地区移动用户数将达到３．７亿,其中移动数据用户将占１．６亿;移动电子商务市场也将于２００３年超过固定电子商务市场。移动互联网未来的热点包括企业网的无线应用、与位置相关的服务以及移动电子商务。