Campos-delgado, Daniel U.; Luna-rivera, J. Martin; Bonilla, Isela
This work studies the distributed power control algorithm proposed in 1993 by Foschini-Miljanic, standardised for universal mobile telecommunication systems. Continuous and discrete time versions of this algorithm are analysed. First, the stability of the distributed power allocation schemes was studied, where sufficient conditions to guarantee stability and convergence to a desired quality of service were provided. In this study, the channel gains are assumed to be slowly time-varying or piece-wise constant. For closed-loop control, a proportional controller is then employed under integral action in order to achieve good tracking despite time-varying and unknown channel gains. Next, the effects of constant and time-varying time delays in the closed-loop structure are studied. Explicit stability regions for the control gains in the Foschini-Miljanic scheme are derived for both the continuous and discrete-time versions of the algorithm, under constant and time-varying delays. For time-varying scenario, the resulting stability regions do not impose limitations on the rate change of the time-varying profiles. A comprehensive evaluation using simulations is performed to validate the analytical derivations described in the paper.
Lee, Lung-Sheng; Chen, Ya-Yan
In Taiwan, human resource development (HRD) is defined as the systematic education, training, and development employers provide for their employees as well as organizational development for corporations. A history of HRD development indicates that in the 1960s, the government began to implement planning measures for HRD in business and industry;…
This 120-page book is a concise, yet comprehensive, clearly-written and well-illustrated monograph that covers the subject matter from basic principles through design, construction and calibration details to the principal applications. The book will be useful, as a primer, to the uninitiated and, as a reference book to the practitioner involved with transformer-type ratio devices. The length of the book and the style of presentation will not overburden any informed reader. The described techniques and the cited references are primarily from the work at the National Research Council, Canada (NRC). Any omissions, however, are not serious with respect to coverage of the subject matter, since most of the development work has been done at NRC. The role of transformers and transformer-like devices for establishing accurate voltage and current ratios has been recognized for over half a century. Transformer techniques were much explored and developed in the fifties and sixties for accuracy levels suitable for standards laboratories. Three-winding voltage transformers were developed for scaling of impedances in connection with the calculable Thompson Lampard capacitor; three-winding current transformers or current comparators were initially explored for the calibration of current transformers and later for specialized impedance measurements. Extensive development of the current comparator and its applications has been and is still being conducted at the NRC by a team that was started and, until his retirement, led by N L Kusters. The team is now led by W J M Moore. He and P N Miljanic, the authors of this book, have had the principal roles in the development of the current comparator. It is fortunate for the field of metrology that considerabe resources and a talented group of researchers were available to do this development along with mechanisms that were available to transfer this technology to a private sector instrument manufacturer and, thus, disseminate it world wide
According to Jaan Valsiner, development takes place within culturally structured environments jointly organized by the activities of children and the people around them. When overlap between promoted activity and the child's zone of proximal development exists, the structure of action that results from the interplay of the two is internalized by…
van Doorn, J.; Hollinger, T. C.; Oudega, B.
A sensitive and specific detection method was developed for Xanthomonas hyacinthi; this method was based on amplification of a subsequence of the type IV fimbrial-subunit gene fimA from strain S148. The fimA gene was amplified by PCR with degenerate DNA primers designed by using the N-terminal and C-terminal amino acid sequences of trypsin fragments of FimA. The nucleotide sequence of fimA was determined and compared with the nucleotide sequences coding for the fimbrial subunits in other type IV fimbria-producing bacteria, such as Xanthomonas campestris pv. vesicatoria, Neisseria gonorrhoeae, and Moraxella bovis. In a PCR internal primers JAAN and JARA, designed by using the nucleotide sequences of the variable central and C-terminal region of fimA, amplified a 226-bp DNA fragment in all X. hyacinthi isolates. This PCR was shown to be pathovar specific, as assessed by testing 71 Xanthomonas pathovars and bacterial isolates belonging to other genera, such as Erwinia and Pseudomonas. Southern hybridization experiments performed with the labelled 226-bp DNA amplicon as a probe suggested that there is only one structural type IV fimbrial-gene cluster in X. hyacinthi. Only two Xanthomonas translucens pathovars cross-reacted weakly in PCR. Primers amplifying a subsequence of the fimA gene of X. campestris pv. vesicatoria (T. Ojanen-Reuhs, N. Kalkkinen, B. Westerlund-Wikström, J. van Doorn, K. Haahtela, E.-L. Nurmiaho-Lassila, K. Wengelink, U. Bonas, and T. K. Korhonen, J. Bacteriol. 179: 1280–1290, 1997) were shown to be pathovar specific, indicating that the fimbrial-subunit sequences are more generally applicable in xanthomonads for detection purposes. Under laboratory conditions, approximately 1,000 CFU of X. hyacinthi per ml could be detected. In inoculated leaves of hyacinths the threshold was 5,000 CFU/ml. The results indicated that infected hyacinths with early symptoms could be successfully screened for X. hyacinthi with PCR. PMID:11157222
Kuusk, P.; Muursepp, P. V.; Piir, Ivar
The first popular lecture on the Einstein theory of relativity was given in Estonia already in 1914 by Jaan Sarv (1877-1954),afterwards a professor of mathematics at the Tartu University. The first student courses on special relativity were delivered by Professor of Mathematics Juri Nuut (1892-1952): non-Euclidean geometry (1930), the mathematical theory of relativity (1932/1933),the Lorenz transformations (1937). His own research work concerned the Lobachevsky geometry  and its application to cosmology . Harald Keres qraguated from the Tartu University in 1936. He gave the first student course on general relativity (based on books [11-14]in 1940.In 1942,he got the dr.phil.nat degree form the Tartu University for his theses "Raum und Zeit in der allgemeinen Relativitatstheorie". The degree of the doctor of mathematical and physical sciences was confirmed by VAK (the All-Union Higher Attestation Commission) in 1949.In this period, he got aquainted with the leading Soviet scientists working on General Relativity, prof.V.A.Fock,Prof.D.D.Ivanenko,Prof.A.Z.Petrov,and Prof.M.F.Shirokov. After World War two all-union university courses were introduced in Tartu State University. According to the curriculum of the course the special theory of relativity is a part of electrodynamics obligatory for all students of the department of Physics. From 1947 till 1985 this course was delivered by Prof.PaulKard(1914-1985).He also published a number of text-books on the subject [15-19]. The general theory of relativity was read by Prof.H.Keres in 1951-1960 and later by his pupils R.Lias and A.Koppel [20-23] as a special course for students specializing in theoretical Physics. The first PHD-s in general relativity were made by R.Lias (1954) and I.Piir  (1955). In 1961, Prof.H.Keres was elected a member of the Academy of Sciences of the Estonian S.S.R. He left the TArtu State University and began to work in the Institute of Physics as the head of the Department of