Queueing models for capacity changes in cellular networks

With the rapid development of cellular communication techniques, many recent studies have focused on improving the quality of service (QoS) in cellular networks. One characteristic of the systems in cellular networks, which can have direct impact on the system QoS, is the fluctuation of the system capacity. In this thesis, the QoS of systems with capacity fluctuations is studied from two perspectives: (1) priority queueing systems with preemption, and (2) the M/M/~C/~C system. In the first part, we propose two models with controlled preemption and analyze their performance in the context of a single reference cell that supports two kinds of traffic (new calls and handoff calls). The formulae for calculating the performance measures of interest (i.e., handoff call blocking probability, new call blocking and dropping probabilities) are developed, and the procedures for solving optimization problems for the optimal number of channels required for each proposed model are established. The proposed controlled preemption models are then compared to existing non-preemption and full preemption models from the following three perspectives: (i) channel utilization, (ii) low priority call (i.e., new calls) performance, and (iii) flexibility to meet various constraints. The results showed that the proposed controlled preemption models are the best models overall. In the second part, the loss system with stochastic capacity, denoted by M/M/~C/~C, is analyzed using the Markov regenerative process (MRGP) method. Three different distributions of capacity interchange times (exponential, gamma, and Pareto) and three different capacity variation patterns (skip-free, distance-based, and uniform-based) are considered. Analytic expressions are derived to calculate call blocking and dropping probabilities and are verified by call level simulations. Finally, numerical examples are provided to determine the impact of different distributions of capacity interchange times and different capacity variation patterns on system performance

Empirical study of dense schedule performance ratio on open-shop scheduling problem

In this paper, we study properties of dense schedules for the open-shop problems and their average performance ratio. After using two sets of test problems, we show that the average performance ratio of dense schedules is actually much better than ( ), the worst-case performance ratio in the conjecture. The results from randomly generated problems which have large sizes show that when the dimension of open-shop problems become larger, the average performance ratio is getting even smaller. Twelve heuristic algorithms to generate dense schedules are presented in Chapter 3 and the computational results of two sets of test problems are also provided

Validation of the Oregon Scientific BPU 330 for self-monitoring of blood pressure according to the International Protocol

Li Li1, XinYu Zhang1, ChunHong Yan1, QingXiang Liang21Biomedical Engineering Lab, Faculty of Information Engineering, ShenZhen University, ShenZhen, China; 2Bao An People’s Hospital, ShenZhen, ChinaObjective: Extensive marketing of devices for self-measurement of blood pressure has created a need for purchasers to be able to satisfy themselves that such devices have been evaluated according to agreed criteria. The Oregon Scientific BPU 330 blood pressure monitor is an electronic device for upper arm measurement. This study assessed the accuracy of the Oregon Scientific BPU 330 blood pressure monitor according to the International Protocol by the Working Group on Blood Pressure Monitoring of the European Society of Hypertension for validation of blood pressure measuring devices.Method: 52 participants over 30 years of age were studied in the validation. Nine blood pressure measurements were taken alternately with a mercury sphygmomanometer by two observers, and by the supervisor, using the BPU 330 device. A total of 33 participants were selected for the analysis. The validation was divided into two phases. Phase 1 included 15 participants. If the device passed phase 1, 18 more participants were included. The 99 pairs of measurements were compared according to the International Protocol. The device was given a pass/fail recommendation based on its accuracy compared with the mercury standard (within 5, 10, and 15 mmHg), as well as the number met in the ranges specified by the International Protocol.Results: The mean and standard deviation of the difference between the mean of the observers and the BPU 330 device were 1.7 ± 4.7 mmHg and 2.8 ± 3.9 mmHg for systolic blood pressure (SBP) and diastolic blood pressure (DBP), respectively. In phase 1, the device passed with a total of 33, 43, and 44 SBP readings; 38, 44, and 45 DBP readings were within 5, 10, and 15 mmHg, respectively. In phase 2.1, 81, 95, and 96 for SBP, and 83, 95, and 98 for DBP readings fell within the zones of 5, 10, and 15 mmHg, respectively. In phase 2.2, the last phase, 28 participants fell within the zone of two of the three comparisons, lying within 5 mmHg for SBP and 29 participants for DBP. No participants fell within the zone of all three of their comparisons over 5 mmHg apart for both SBP and DBP.Conclusion: The BPU 330 can be recommended for self-monitoring of blood pressure in the adult population, according to the International Protocol.Keywords: blood pressure, self-monitoring, hypertension, International Protoco

Conditional Concordance-Assisted Learning Under Matched Case-Control Design For Combining Biomarkers For Population Screening

Incorporating promising biomarkers into cancer screening practices for early-detection is increasingly appealing because of the unsatisfactory performance of current cancer screening strategies. The matched case-control design is commonly adopted in biomarker development studies to evaluate the discriminative power of biomarker candidates, with an intention to eliminate confounding effects. Data from matched case-control studies have been routinely analyzed by the conditional logistic regression, although the assumed logit link between biomarker combinations and disease risk may not always hold. We propose a conditional concordance-assisted learning method, which is distribution-free, for identifying an optimal combination of biomarkers to discriminate cases and controls. We are particularly interested in combinations with a clinically and practically meaningful specificity to prevent disease-free subjects from unnecessary and possibly intrusive diagnostic procedures, which is a top priority for cancer population screening. We establish asymptotic properties for the derived combination and confirm its favorable finite sample performance in simulations. We apply the proposed method to the prostate cancer data from the carotene and retinol efficacy trial (CARET)

Novel effects of piperlogumine on uterine fibroid tumor: An in vitro mouse model study

Purpose: To investigate the in vivo anti-tumor effect of piperlongumine (PL) in a mouse model of leiomyoma xenograft and in leiomyoma cell lines. Methods: The anti-proliferative effect of PL on ELT-3 cells was determined using MTT assay. Human and rat leiomyoma cells were used for the in vitro investigations. Rat leiomyoma cell lines were treated with various PL concentrations (50 - 100 μM)) for 48 h. Immunodeficient mice were subcutaneously injected with varying doses of estrogen or progesterone, and xenografted with explanting human leiomyoma cells in in vivo experiments. Proliferation assessment, caspase-3 expression, analysis of tumour samples, insertion of pellets of oestrogen-progesterone, tissue treatment and implantation, and immuno-histochemical analyses were carried out using appropriate procedures. Results: Piperlongumine (PL) produced significant and dose-dependent increase in caspase-3 activity, apoptosis and suppression of cellular proliferation (p < 0.01). Moreover, Western blot data demonstrated that PL decreased phosphorylation of Akt signaling pathway. The results showed significant (p < 0.01) inhibition of tumor growth, including in ultra-sound in vivo studies, when compared with 30-day control and animals treated with PL (100 μg/g). Immuno-histochemical studies showed that PL decreased the expression of proliferation marker in xenografted tumor tissues (p < 0.02). Conclusion: These results suggest that piperlongumine has potentials as a therapeutic agent for the management of uterine leiomyoma. However, additional studies using human cell lines are required to understand its genetic and molecular mechanisms

Evaluation of a novel saliva-based epidermal growth factor receptor mutation detection for lung cancer: A pilot study.

BackgroundThis article describes a pilot study evaluating a novel liquid biopsy system for non-small cell lung cancer (NSCLC) patients. The electric field-induced release and measurement (EFIRM) method utilizes an electrochemical biosensor for detecting oncogenic mutations in biofluids.MethodsSaliva and plasma of 17 patients were collected from three cancer centers prior to and after surgical resection. The EFIRM method was then applied to the collected samples to assay for exon 19 deletion and p.L858 mutations. EFIRM results were compared with cobas results of exon 19 deletion and p.L858 mutation detection in cancer tissues.ResultsThe EFIRM method was found to detect exon 19 deletion with an area under the curve (AUC) of 1.0 in both saliva and plasma samples in lung cancer patients. For L858R mutation detection, the AUC of saliva was 1.0, while the AUC of plasma was 0.98. Strong correlations were also found between presurgery and post-surgery samples for both saliva (0.86 for exon 19 and 0.98 for L858R) and plasma (0.73 for exon 19 and 0.94 for L858R).ConclusionOur study demonstrates the feasibility of utilizing EFIRM to rapidly, non-invasively, and conveniently detect epidermal growth factor receptor mutations in the saliva of patients with NSCLC, with results corresponding perfectly with the results of cobas tissue genotyping

Comparisons of time series of annual mean surface air temperature for China since the 1900s: Observations, model simulations and extended reanalysis

This paper assesses the similarities and differences of several annual average SAT time series for China based on historical meteorological observations since the 1900s. Time series of global or regional average surface air temperature (SAT) are fundamental to climate change studies. A number of studies have developed several national and regional SAT series for China, but due to the diversity of meteorological observational sites, different quality control routines for data and the inconsistency of statistical methods used, they differ in long-term trends. This paper assesses the similarities and differences of the existing time series of the annual average SAT for China that are based upon historical meteorological observations since the 1900s. The results indicate that the China average is similar to the series for the Northern Hemisphere (NH) landmass, except that the initial warming of the NH series derived from the CRUTEM3/4 datasets ends earlier (before the early 1940s) than in China’s series. A major difference among the existing China average time series is the 1940s warmth, a period when there were very few observations across the country due to World War II. The SAT anomalies for China during the 1930s-1940s have been reduced by improved homogeneity assessment compared to previous estimates. The new improved time series is in better agreement with both the historical 20th century reanalysis data and the historical climate simulation of CMIP5 models. The new time series also shows the slowdown of the warming trend during the past 18 years (1998-2015). The best estimate of a linear trend for increases in temperature with a 95% uncertainty range is 0.121±0.009 °C per decade for 1900-2015, indicating that the improved homogeneity assessment for China leads to a slightly greater trend than that based on raw data (0.107±0.009 °C per decade)

A new integrated and homogenized global monthly land surface air temperature dataset for the period since 1900

A new dataset of integrated and homogenized monthly surface air temperature over global land for the period since 1900 [China Meteorological Administration global Land Surface Air Temperature (CMA-LSAT)] is developed. In total, 14 sources have been collected and integrated into the newly developed dataset, including three global (CRUTEM4, GHCN, and BEST), three regional and eight national sources. Duplicate stations are identified, and those with the higher priority are chosen or spliced. Then, a consistency test and a climate outlier test are conducted to ensure that each station series is quality controlled. Next, two steps are adopted to assure the homogeneity of the station series: (1) homogenized station series in existing national datasets (by National Meteorological Services) are directly integrated into the dataset without any changes (50% of all stations), and (2) the inhomogeneities are detected and adjusted for in the remaining data series using a penalized maximal t test (50% of all stations). Based on the dataset, we re-assess the temperature changes in global and regional areas compared with GHCN-V3 and CRUTEM4, as well as the temperature changes during the three periods of 1900–2014, 1979–2014 and 1998–2014. The best estimates of warming trends and there 95% confidence ranges for 1900–2014 are approximately 0.102 ± 0.006 °C/decade for the whole year, and 0.104 ± 0.009, 0.112 ± 0.007, 0.090 ± 0.006, and 0.092 ± 0.007 °C/decade for the DJF (December, January, February), MAM, JJA, and SON seasons, respectively. MAM saw the most significant warming trend in both 1900–2014 and 1979–2014. For an even shorter and more recent period (1998–2014), MAM, JJA and SON show similar warming trends, while DJF shows opposite trends. The results show that the ability of CMA-LAST for describing the global temperature changes is similar with other existing products, while there are some differences when describing regional temperature changes

Generation of Numerical Models of Anisotropic Columnar Jointed Rock Mass Using Modified Centroidal Voronoi Diagrams

A columnar joint network is a natural fracture pattern with high symmetry, which leads to the anisotropy mechanical property of columnar basalt. For a better understanding the mechanical behavior, a novel modeling method for columnar jointed rock mass through field investigation is proposed in this paper. Natural columnar jointed networks lies between random and centroidal Voronoi tessellations. This heterogeneity of columnar cells in shape and area can be represented using the coefficient of variation, which can be easily estimated. Using the bisection method, a modified Lloyd’s algorithm is proposed to generate a Voronoi diagram with a specified coefficient of variation. Modelling of the columnar jointed rock mass using six parameters is then presented. A case study of columnar basalt at Baihetan Dam is performed to demonstrate the feasibility of this method. The results show that this method is applicable in the modeling of columnar jointed rock mass as well as similar polycrystalline materials

The effect of calcium propionate on the ruminal bacterial community composition in finishing bulls

Objective Manipulating the fermentation to improve the performance of the ruminant has attracted the attention of both farmers and animal scientists. Propionate salt supplementation in the diet could disturb the concentration of propionate and total volatile fatty acids in the rumen. This study was conducted to evaluate the effect of calcium propionate supplementation on the ruminal bacterial community composition in finishing bulls. Methods Eight finishing bulls were randomly assigned to control group (CONT) and calcium propionate supplementation (PROP) feeding group, with four head per group. The control group was fed normal the total mixed ration (TMR) finishing diet, and PROP group was fed TMR supplemented with 200 g/d calcium propionate. At the end of the 51-day feeding trial, all bulls were slaughtered and rumen fluid was collected from each of the animals. Results Propionate supplementation had no influence the rumen fermentation parameters (p>0.05). Ruminal bacterial community composition was analyzed by sequencing of hypervariable V3 regions of the 16S rRNA gene. The most abundant phyla were the Firmicutes (60.68%) and Bacteroidetes (23.67%), followed by Tenericutes (4.95%) and TM7 (3.39%). The predominant genera included Succiniclasticum (9.43%), Butyrivibrio (3.74%), Ruminococcus (3.46%) and Prevotella (2.86%). Bacterial community composition in the two groups were highly similar, except the abundance of Tenericutes declined along with the calcium propionate supplementation (p = 0.0078). Conclusion These data suggest that the ruminal bacterial community composition is nearly unchanged by propionate supplementation in finishing bulls