高速数字传输中的帧同步提取分析

本文讨论具有帧结构的高速数字流的帧同步提取技术。从帧同步器方案的最佳参数设计出发,以误码性能为主要目标,本文较系统地提出了一套有关帧同步过程的基本概念和分析方法,并导出在各种情况下的统计关系及重要结论。本文还以美国陆地卫星TM数据流为例,特别阐述了复帧结构情况下的帧同步提取及其最佳参数设计。     

Clean-up of wastewater containing zinc and aluminum simultaneously

Conclusions When zinc is replaced by aluminum in viscose fibre technology, the volume of the settler in water clean-up units must be increased by a factor of 1.2–1.6.In spinning fibre into a zinc-aluminum-containing precipitation bath, it is advisable to isolate the zinc and aluminum from the wastewater and to use them repeatedly in the form of a zinc- and aluminum-containing product.Translated from Khimicheskie Volokna, No. 6, pp. 41–43, November–December, 1989.     

Adsorption of soy oil free fatty acids by rice hull ash

Studies demonstrated that free fatty acids can be adsorbed from a soybean oil/hexane miscella by inorganic rice hull ash. A 1% dose was effective in diminishing free fatty acid concentrations but acid activation reduced the adsorption. Binding of free fatty acids followed a Freundlich isotherm with smaller doses of ash adsorbing more efficiently. Addition of isopropanol to the miscella promoted the adsorption, while water deactivation of the ash had no effect, possibly because water occupied sites not accessible to free fatty acids. Impaired adsorption behavior of ash heated above 700°C could have been due to disruption of the crystal form. The adsorption behavior of rice hull ash may be more fully understood with a better knowledge of adsorbent structure.     

Einflüsse von Triazolapplikationen auf Kornertrag und -qualität von Winterraps

Effects of Growth Substance Applications (Triazole) on Yield Formation and Grain Quality of Winter Rape Field trials have been conducted for two years (1986/87 and 1987/88) with cv. Lirabon (low erucic acid and low glucosinolate content). At several growth stages uptil beginning of flowering and at different rates the triazole RSW 0411 (Bayer) was applied. The problem was to investigate growth regulator effects on agronomically important traits, the utilization of yield potential and on seed quality. Applications during stem elongation reduced plant height phoma lingam infestation and lodging. Branching and numbers of pods/plant increased, partly on costs of pod filling. In 1986/87 grain yields/ha indicated (not significant) increases without any effects on grain quality. In 1987/88 grain yield/ha decreased significantly combined with increasing protein- and glucosinolate contents.     

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.     

The polymerase chain reaction: Applications for the detection of foodborne pathogens

Faster methods for the detection of foodborne microbial pathogens are needed. The polymerase chain reaction (PCR) can amplify specific segments of DNA and is used to detect and identify bacterial genes responsible for causing diseases in humans. The major features and requirements for the PCR are described along with a number of important variations. A considerable number of PCR‐based assays have been developed, but they have been applied most often to clinical and environmental samples and more rarely for the detection of foodborne microorganisms. Much of the difficulty in implementing PCR for the analysis of food samples lies in the problems encountered during the preparation of template DNAs from food matrices; a variety of approaches and considerations are examined. PCR methods developed for the detection and identification of particular bacteria, viruses, and parasites found in foods are described and discussed, and the major features of these reactions are summarized.     

Oxidatively modified LDL and atherosclerosis: An evolving plausible scenario

Much evidence has accumulated that implicates the oxidative modification of low‐density lipoprotein (LDL) in the early stages of atherogenesis. The antioxidant nutrients alpha‐tocopherol, ascorbic acid, and beta‐carotene have been shown to inhibit in vitro LDL oxidation. In addition, they have been shown to increase the resistance of LDL to oxidation when given to animals and humans. Because plasma levels of these nutrients can be increased by dietary supplementation with minimal side effects, they may show promise in the prevention of coronary artery disease.     

IT-Security in der Energieautomatisierung

The increasing use of information technology in energy distribution and the wide interconnection of such systems bring security issues into the focus of interest. This contribution introduces the essential concepts and concentrates on specific security requirements and risks in energy automation. At the example of the two different data acquisition systems REMPLI and JEVis a possible implementation of security concepts is discussed.     

Interoperability testing of Web Services for e-learning

Web Service technologies seem to open interesting unexplored scenarios in the e-learning domain. Particularly appealing is the possibility of defining and standardizing services that, when implemented and composed, will result in complex e-learning applications. However, an agreed standard specification per se is not sufficient, rather methodologies for validating conformance against it have to be released. This paper discusses current approaches to standardise Web Service specification and implementation and outlines an approach to conformance verification of services through testing, aiming at reducing the risk of interoperability issues at execution time.