scholarly journals Improvement and Performance Evaluation When Implementing a Distance-Based Registration

2021 ◽  
Vol 11 (15) ◽  
pp. 6823
Author(s):  
Jang Hyun Baek

An efficient location registration scheme is essential to continuously accommodate the increasing number of mobile subscribers and to offer a variety of multimedia services with good quality. The objective of this study was to analyze the optimal size for the location area of a distance-based registration (DBR) scheme by varying the number of location areas on a cell-by-cell basis, not on a ring-by-ring basis. Using our proposed cell-by-cell distance-based registration scheme with a random walk mobility model, a variety of circumstances were analyzed to obtain the optimal number of cells for location area for minimizing the total signaling cost on radio channels. Analysis results showed that the optimal number of cells for location area was between 4 and 7 in most cases. Our cell-by-cell distance-based location registration scheme had less signaling cost than an optimal ring-by-ring distance-based location registration scheme with an optimal distance threshold of 2 (the optimal number of cells for location area was 7). Therefore, when DBR is adopted, it must be implemented with an LA increasing on a cell-by-cell basis to achieve optimal performance.

2007 ◽  
Vol 24 (05) ◽  
pp. 667-685 ◽  
Author(s):  
JANG-HYUN BAEK ◽  
KYUNG-HEE KIM ◽  
DOUGLAS C. SICKER

An efficient mobility management for mobile stations plays an important role in mobile communication networks. Two basic operations of mobility management are location registration and paging. A zone-based registration (ZBR) is implemented in most of the mobile communication networks and we consider the mobility management scheme that combines a zone-based registration and a selective paging (SP). We propose a new analytical model that can reflect the characteristics of the ZBR smoothly where location areas of the ZBR are set up so that regions such as roads, bridges, rivers and mountains, where there is relatively little traffic, will constitute their boundaries. We adopt a revised 2-dimensional random walk mobility model to consider such characteristics. In addition, we propose a more efficient division scheme of location area for 2-step selective paging. We evaluate the performance of the mobility management scheme using our mobility model to determine the optimal size of a location area that will result in the minimum signaling traffic on radio channels. Numerical results are provided to demonstrate that our mobility model is useful to evaluate the ZBR more exactly. The results of this study can be used effectively in analyzing and comparing the performances of various mobility management schemes.


2020 ◽  
Author(s):  
Kuba Nowak ◽  
Paweł Błażej ◽  
Małgorzata Wnetrzak ◽  
Dorota Mackiewicz ◽  
Paweł Mackiewicz

1AbstractReprogramming of the standard genetic code in order to include non-canonical amino acids (ncAAs) opens a new perspective in medicine, industry and biotechnology. There are several methods of engineering the code, which allow us for storing new genetic information in DNA sequences and transmitting it into the protein world. Here, we investigate the problem of optimal genetic code extension from theoretical perspective. We assume that the new coding system should encode both canonical and new ncAAs using 64 classical codons. What is more, the extended genetic code should be robust to point nucleotide mutation and minimize the possibility of reversion from new to old information. In order to do so, we follow graph theory to study the properties of optimal codon sets, which can encode 20 canonical amino acids and stop coding signal. Finally, we describe the set of vacant codons that could be assigned to new amino acids. Moreover, we discuss the optimal number of the newly incorporated ncAAs and also the optimal size of codon blocks that are assigned to ncAAs.


Computation ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 71
Author(s):  
Miroslava Mikusova ◽  
Jamshid Abdunazarov ◽  
Joanna Zukowska ◽  
Juraj Jagelcak

Nowadays, in all cities, there is an acute problem of a lack of parking spaces. The number of vehicles is constantly increasing not only in big cities and megacities, but also in small towns of the country, and there are not enough parking places—the pace of solving the problem is several times slower than the growth rate of transport among citizens. The paper is dedicated to the determination of an optimal size of a parking place for design vehicles in a parking space as an element of roads. In the example of passenger cars and trucks, the optimal number of parking places is presented. The results of the research on the dimensioning of parking spaces serve as recommendations and can be used for the design of objects of transportation infrastructure. According to the research, authors introduce the term “design vehicle” and provide its definition. They also figure out optimal parameters for each design vehicle and recommend a special template for designing parking places.


1981 ◽  
Vol 18 (01) ◽  
pp. 65-75 ◽  
Author(s):  
Aidan Sudbury

In cell-size-dependent growth the probabilistic rate of division of a cell into daughter-cells and the rate of increase of its size depend on its size. In this paper the expected number of cells in the population at time t is calculated for a variety of models, and it is shown that population growths slower and faster than exponential are both possible. When the cell sizes are bounded conditions are given for exponential growth.


2004 ◽  
Vol 24 (14) ◽  
pp. 6268-6277 ◽  
Author(s):  
Yonghong Zhu ◽  
Carmen Alvarez ◽  
Ronald Doll ◽  
Hirokazu Kurata ◽  
Xiao Min Schebye ◽  
...  

ABSTRACT To ensure proper progression through a cell cycle, checkpoints have evolved to play a surveillance role in maintaining genomic integrity. In this study, we demonstrate that loss of CDK2 activity activates an intra-S-phase checkpoint. CDK2 inhibition triggers a p53-p21 response via ATM- and ATR-dependent p53 phosphorylation at serine 15. Phosphorylation of other ATM and ATR downstream substrates, such as H2AX, NBS1, CHK1, and CHK2 is also increased. We show that during S phase when CDK2 activity is inhibited, there is an unexpected loading of the minichromosome maintenance complex onto chromatin. In addition, there is an increased number of cells with more than 4N DNA content, detected in the absence of p53, suggesting that rereplication can occur as a result of CDK2 disruption. Our findings identify an important role for CDK2 in the maintenance of genomic stability, acting via an ATM- and ATR-dependent pathway.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4394-4394
Author(s):  
Vanessa de Souza Valim ◽  
Fernanda Oliveira ◽  
Maria Aparecida Lima da Silva ◽  
Bruna Amorin ◽  
Lauro Moraes ◽  
...  

Abstract Abstract 4394 Introduction and objectives: Studies with mesenchymal stem cells (MSCs) have shown its benefits in hematology, mainly for Graft-versus-host disease (Lancet 371:1579–86, 2008), with three unsettled matters: (1)MSCs expansion in medium supplemented with Fetal Calf Serum (FCS) and its risk of xenoreaction (Blood 89:776–9, 1997); (2)The optimal number of cells needed for therapy is not yet defined, but there is an empirical indication for 2×106células/Kg with the need to optimize expansion, number and time wise; and (3)the utilization of third party donors. This study was designed to determine the superiority or no-inferiority of the Platelet Lysates (PL) over FCS on the expansion of MSC, the optimal cell plating density and days between each pass, and to investigate if in our conditions total nucleated cells (TNC) obtained from the washouts of HSCT explants can expand to be used at clinical grade. Methods and Results: TNC were removed from the filters and bags used in the HSCT (Cytotherapy 11:403–13, 2009) and after the first passage were plated in different concentrations (2000/cm2, 3000/cm2, 4000/cm2, 5000/cm2, 6000/cm2 and 7000/cm2) with 10% FBS or 10% PL, and the number of days reach 80% of confluence was observe (Transfusion, 49:2680–5, 2009). Next, cultures with the same plating density were fed either with 10% PL or 10% FCS and were trypsinized after seven days and counted to analyze how much they have grown in that time period. And finally, cultures were allowed to growth up to Passage 3 (P3) to test the ability to obtain clinical grade number of cells. The proliferation of mesenchymal stem cells in the presence of PL and SFB was averaged 11.88 and 2.5 times, respectively, in a period of 7 days (p = 0.005). The highest concentration of plating cells using PL, took less time (6 days) to reach confluence as compared with the three lower (7.55 to 8.55 days) (p = 0.005), and at P3 with PL we obtained from 10×109 up to 10 × 1011 cells. Conclusion: This study suggests that the PL is the best choice as a supplement to expand MSC, and allow the proliferation of a sufficient number of MSC at P3 for clinical use obtained from the washouts of HSCT explants. Disclosures: No relevant conflicts of interest to declare.


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