Paging Procedure Research Articles

On location management for personal communications networks

Personal communications services (PCS) support mobile terminals (MTs) which are free to travel within the service coverage area. In order to effectively locate an MT when a called is initiated, location management schemes are used to keep track of the locations of the MTs. The current approach to location management requires each MT to report its location to the network periodically. The location information is then stored in databases. When a call is initiated. The network determines the current location of the called MT through a database lookup and paging procedure. A currently available standard for location management is described. Research results on location management are surveyed in detail.

Quickest detection for sequential decentralized decision systems

Quickest detection procedures are techniques used to detect sudden or abrupt changes (also called disorders) in the statistics of a random process. The goal is to determine as soon as possible that the change occurred, while at the same time minimizing the chance of falsely signaling the occurrence of a disorder before the change. In this work the distributed quickest detection problem when the disorder occurs at an unknown time is considered. The distributed local detectors utilize a simple summing device and threshold comparator, with a binary decision at the output. At the fusion center, the optimal maximum likelihood (ML) procedure is analyzed and compared with the more practical Page procedure for quickest detection. It is shown that the two procedures have practically equivalent performance. For the important case of unknown disorder magnitudes, a version of the Hinkley procedure is also examined. Next, a simple method for choosing the thresholds of the local detectors based on an asymptotic performance measure is presented. The problem of selecting the local thresholds usually requires optimizing a constrained set of nonlinear equations; our method admits a separable problem, leading to straightforward calculations. A sensitivity analysis reveals that the resulting threshold settings are optimal for practical purposes. The issue of which sample size to use for the local detectors is investigated, and the tradeoff between decision delay and communication cost is evaluated. For strong signals, it is shown that the relative performance deteriorates as the sample size increases, that is, as the system cost decreases. Surprisingly, for the weak signal case, lowering the system cost (increasing the sample size) does not necessarily result in a degradation of performance.

Minimizing the average cost of paging under delay constraints

Efficient paging procedures help minimize the amount of bandwidth expended in locating a mobile unit. Given a probability distribution on user location, it is shown that the optimal paging strategy which minimizes the expected number of locations polled $E[L]$ is to query each location sequentially in order of decreasing probability. However, since sequential search over many locations may impose unacceptable polling delay, D, optimal paging subject to delay constraints is considered. It is shown that substantial reductions in E[L] can be had even after moderate constraints are imposed on acceptable D (i.e., D \leq 3). Since all methods of mobility management eventually reduce to considering a time-varying probability distribution on user location, this work should be applicable to a wide range of problems in the area. most notably those with additive cost structures.

Intelligent paging strategies for third generation mobile telecommunication systems

Location management procedures, in conjunction with the millions of users expected to subscribe to third generation mobile telecommunication systems, will generate a huge signaling load. In this paper, we propose a method which aims at the reduction of signaling overhead on the radio link produced by the paging procedure. The key idea is the application of a multiple step paging strategy which operates as follows: at the instance of a call terminating to a mobile user who roams within a certain location area, paging is initially performed in a portion of the location area (the paging area) that the so-called "paging related information" indicates. On no paging response, the mobile user is paged in the complementary portion of the location area-this phase can be completed in more than one (paging) step. Various "paging related information" elements (e.g. recent interaction information, high mobility flag, etc.) can be used and several "intelligent" paging strategies can be defined. Representative paging strategies are analyzed in terms of network performance and quality of service (paging signaling, paging delay, processing power requirements), via a simulation tool which models a realistic city area environment.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Assessment of lymphokine profiles in activated lymphocytes by semiquantitative PCR

Several methods are currently used to detect the expression of specific mRNAs in leukocytes. While Northern blot analysis and RNase protection assays are commonly chosen for quantitative assessment of mRNA levels, these methods require a significant quantity of RNA, making their use unfeasible when limiting numbers of cells are available. Alternatively, use of the reverse transcription-polymerase chain reaction (RT-PCR) technique allows detection of specific mRNAs even at low copy number. It is, however, difficult to establish the conditions which allow consistent semi-quantitative assessment of specific mRNA expression, using the RT-PCR method. We report here a modification of the RT-PCR technique, which has enabled us to compare lymphokine mRNA expression profiles in mixed cell populations activated either in vivo or in vitro. This modification is based on the use of standard RNAs generated by in vitro transcription of size-modified CD3 and IFN-γ-specific PCR products subcloned into the pGEM3 plasmid. Equal amounts of standard RNAs are introduced into each sample, reverse transcribed and co-amplified with cellular mRNA to control the reproducibility and efficiency of the method. The template therefore follows the cellular RNA through all steps of the analysis, and the corresponding 32P-labelled PCR products are subsequently separated by PAGE procedure. The amount of radioactivity incorporated into lymphokine-specific bands is determined by densitomery aand normalized against the density of standard bands. Under optimal PCR conditions this method is linear over a 50-fold range of dilutions. The technique is specific, reproducible and fast, allowing an analysis of lymphokine-specific mRNA profiles in samples containing 10 4–10 6 cells.

A simplified SDS—PAGE procedure for separating LMW subunits of glutenin

Wheat dough characteristics and end-use quality are strongly influenced by the amount and specific composition of the glutenins, the major components of gluten. Such proteins are divided into high-molecular-weight glutenins, encoded by the Glu-A1, Glu-B1 and Glu-D1 loci; and low-molecular-weight glutenins, encoded by the Glu-A3, Glu-B3 and Glu-D3 loci. Allelic variation at each of these loci has been associated with changes in wheat functionality. However, most of the studies conducted so far included a relatively limited number of genotypes. Also for this reason, it is still unclear which locus contributes more to dough characteristics and how important are the interactions between the glutenin loci. To try to answer these questions, the quality data of 4623 grain samples derived from 2550 genotypes and generated across 10 years at the CIMMYT bread wheat breeding program, was used to estimate the effect of the glutenin loci and their interactions on gluten quality and bread-making potential. Gluten strength was the trait more strongly influenced by glutenin variations, with the Glu-B1, Glu-D1 and Glu-B3 loci having the greatest effect. Among the glutenin alleles, Glu-A1a, Glu-A1b, Glu-B1al, Glu-B1i, Glu-B1f, Glu-D1d, Glu-A3b, Glu-A3d, Glu-A3f, Glu-B3c and Glu-B3d were associated in general with greater gluten strength, good extensibility and higher bread loaf volume. Differently, alleles Glu-A1c, Glu-B1a, Glu-B1d, Glu-D1a, Glu-A3e and Glu-B3j were associated with an overall poor quality. Glutenin interactions were significantly associated with most of the analyzed quality traits even if their influence was often lower compared to the effect of the single glutenin loci. This is probably the largest study ever done on the effects of the glutenins on wheat quality. The results obtained confirm the importance of such proteins on wheat quality variation and corroborate the usefulness of determining the glutenin profile to improve the selection efficiency for wheat quality in breeding programs.

Sympathectomy stimulates capillary but not precapillary growth in hypertrophic hearts

Sympathetic nerves are known to influence vascular growth, but their role in coronary vascular adaptations to pressure-overload left ventricular (LV) hypertrophy is unknown. Accordingly, regional sympathectomy (SYMX) was produced by painting a ring of phenol on the posterior third of the LV in seven renal hypertensive (Page: 1 kidney, 1 wrap) and seven normotensive (sham: 1 kidney, no wrap) rabbits. Two months later, maximal myocardial blood flow (MBF) following dipyridamole-induced coronary vasodilation was determined with microspheres in the intact anterior and the sympathectomized posterior regions of conscious rabbits. Histomorphometric methods were then utilized to evaluate capillary density (CD), intercapillary distance (ICD), and volume density (VD) of subepicardial and endocardial samples of each region of perfused-fixed hearts. The Page procedure significantly increased systolic blood pressure (+29%) and LV wt/body wt (+20%) above sham rabbits. In both sham and Page groups, MBF was not significantly different between intact and sympathectomized regions within either group. SYMX did not significantly alter CD, ICD, or VD between regions in the sham animals. In contrast, SYMX significantly increased CD (+30%) and VD (+26%) and decreased ICD (-21%) in the subendocardial region of Page animals. Regional SYMX did not alter myocyte cross-sectional area in Page animals. We conclude that SYMX neither 1) significantly increases resistance vessel cross-sectional lumen area in either normal or hypertrophic hearts, nor 2) significantly influences capillary growth in normal hearts, but SYMX does 3) promote capillary growth in hearts undergoing hypertrophy in response to hypertension.

Ovulation and Early Embryogenesis in Swine1

Thirty gilts were used to examine if the sequence in which oocytes were released at ovulation contributed to differences in embryonic development and uterine secretions by Day 12 (Day 0 = onset of estrus). Oocytes of follicles destined to ovulate last were recovered 42 h after injecting proestrous gilts with hCG, incubated with a fluorescent stain, and returned to the donor's oviduct. These later-maturing oocytes subsequently became the lesser-developed (p less than 0.01) embryos on Day 4. In a second experiment, lesser- vs. more-developed Day 4 embryos from additional gilts were transferred to ligated uterine horns of nonpregnant gilts. Subsequently, the lesser-developed Day 4 embryos became the smaller (p less than 0.01) blastocysts within a litter on Day 12. Uterine flushings associated with lesser-developed embryos on Day 12 contained less estradiol (p less than 0.01), less total protein (p less than 0.10), and less acid phosphatase activity (p less than 0.05), but total content of calcium was not different compared to flushings that contained more-developed embryos. Analysis of uterine flushings with two-dimensional PAGE procedures indicated advanced uteroferrin-associated glycoprotein secretion from the horn that contained more-developed embryos. Results of these experiments suggested that oocytes of later-ovulating follicles were progenitors of smaller embryos, which probably stimulated uterine secretion later than more advanced littermates on Day 12.

Acid PAGE procedure for detection of phaseolins in field beans (Phaseolus vulgaris L.)

A procedure based on acid polyacrylamide gel electrophoresis (acid PAGE) has been described. Resolution of phaseolin bands appears to be relatively superior to that obtained with basic PAGE system. The procedure discriminates S, T, C, M and B types of phaseolins; S, T and C have been reported previously while M and B types were identified in the present study.

A diffusion process and its applications to detecting a change in the drift of Brownian motion

Abstract : The purpose of the present paper is to make a quantitative comparison of the Shiryayev-Roberts and Page procedures. We do this in the context of continuous time in order to use the machinery of diffusion processes to perform explicitly certain calculations, which seem impossible in discrete time. Although the continuous time results are not especially good approximations to the corresponding quantities in discrete time, they provide very useful comparative information on which to base selection of a stopping rule. This paper is organized as follows. The Shiryayev-Roberts process is defined and shown to be a novel diffusion process with some surprising properties. We also specify more precisely the basis for our comparison of the two procedures and give the results of some elementary calculations. These developments contain an asymptotic evaluation. We define a modification of our basic procedure and give an asymptotic evaluation of its average run length. Numerical comparisons and a discussion of their significance are contained next. Our conclusions are roughly these. In simple situations where the two procedures can be directly compared, neither seems dramatically superior to the other. However, the Shiryayev-Roberts procedure is more easily adapted to complex circumstances and consequently warrants additional study.

On Sequential Detection of a Shift in the Probability of a Rare Event

Abstract Suppose one is monitoring a sequence of observations for a possible increase in the probability of a rare event, and that it is not possible to immediately stop the process under observation or influence it to return to its normal state. One would then desire a scheme which takes advantage of observations occurring after a detection of a change is proclaimed. A modification of Page's CUSUM Procedure is developed, taking account of these additional observations. A table is given enabling one to select a modified Page procedure with a specified rate of false alarms. A comparison is made between the modified Page procedure and a procedure proposed by Chen (1978).

On Sequential Detection of a Shift in the Probability of a Rare Event

Abstract Suppose one is monitoring a sequence of observations for a possible increase in the probability of a rare event, and that it is not possible to immediately stop the process under observation or influence it to return to its normal state. One would then desire a scheme which takes advantage of observations occurring after a detection of a change is proclaimed. A modification of Page's CUSUM Procedure is developed, taking account of these additional observations. A table is given enabling one to select a modified Page procedure with a specified rate of false alarms. A comparison is made between the modified Page procedure and a procedure proposed by Chen (1978).

BARLEY CULTIVAR IDENTIFICATION BY ELECTROPHORETIC ANALYSIS OF HORDEIN PROTEINS II. CATALOGUE OF ELECTROPHOREGRAM FORMULAE FOR CANADIAN-GROWN BARLEY CULTIVARS

Hordein proteins, extracted from 62 Canadian-grown two- and six-rowed barley cultivars and six American-grown six-rowed barley cultivars, were separated by polyacrylamide gel electrophoresis at acid pH. Band mobilities were shown to be reproducible within ± 0.005 relative mobility units. Hordein electrophoregram formulae were determined and catalogued for the 68 barley cultivars analyzed. Twenty-five of the cultivars produced unique electrophoregram formulae. The remaining 43 cultivars were divided into 17 groups, each containing between two and eight indistinguishable cultivars. Further analysis of electrophoregram formulae for Canadian-grown barley cultivars revealed that the majority of malting barley cultivars were distinguishable from feed barley cultivars. The usefulness of the acidic PAGE procedure for the identification of Canadian-grown barley cultivars is evaluated.