Towards a novel biologically-inspired cloud elasticity framework

With the widespread use of the Internet, the popularity of web applications has significantly increased. Such applications are subject to unpredictable workload conditions that vary from time to time. For example, an e-commerce website may face higher workloads than normal during festivals or promotional schemes. Such applications are critical and performance related issues, or service disruption can result in financial losses. Cloud computing with its attractive feature of dynamic resource provisioning (elasticity) is a perfect match to host such applications. The rapid growth in the usage of cloud computing model, as well as the rise in complexity of the web applications poses new challenges regarding the effective monitoring and management of the underlying cloud computational resources. This thesis investigates the state-of-the-art elastic methods including the models and techniques for the dynamic management and provisioning of cloud resources from a service provider perspective. An elastic controller is responsible to determine the optimal number of cloud resources, required at a particular time to achieve the desired performance demands. Researchers and practitioners have proposed many elastic controllers using versatile techniques ranging from simple if-then-else based rules to sophisticated optimisation, control theory and machine learning based methods. However, despite an extensive range of existing elasticity research, the aim of implementing an efficient scaling technique that satisfies the actual demands is still a challenge to achieve. There exist many issues that have not received much attention from a holistic point of view. Some of these issues include: 1) the lack of adaptability and static scaling behaviour whilst considering completely fixed approaches; 2) the burden of additional computational overhead, the inability to cope with the sudden changes in the workload behaviour and the preference of adaptability over reliability at runtime whilst considering the fully dynamic approaches; and 3) the lack of considering uncertainty aspects while designing auto-scaling solutions. This thesis seeks solutions to address these issues altogether using an integrated approach. Moreover, this thesis aims at the provision of qualitative elasticity rules. This thesis proposes a novel biologically-inspired switched feedback control methodology to address the horizontal elasticity problem. The switched methodology utilises multiple controllers simultaneously, whereas the selection of a suitable controller is realised using an intelligent switching mechanism. Each controller itself depicts a different elasticity policy that can be designed using the principles of fixed gain feedback controller approach. The switching mechanism is implemented using a fuzzy system that determines a suitable controller/- policy at runtime based on the current behaviour of the system. Furthermore, to improve the possibility of bumpless transitions and to avoid the oscillatory behaviour, which is a problem commonly associated with switching based control methodologies, this thesis proposes an alternative soft switching approach. This soft switching approach incorporates a biologically-inspired Basal Ganglia based computational model of action selection. In addition, this thesis formulates the problem of designing the membership functions of the switching mechanism as a multi-objective optimisation problem. The key purpose behind this formulation is to obtain the near optimal (or to fine tune) parameter settings for the membership functions of the fuzzy control system in the absence of domain experts’ knowledge. This problem is addressed by using two different techniques including the commonly used Genetic Algorithm and an alternative less known economic approach called the Taguchi method. Lastly, we identify seven different kinds of real workload patterns, each of which reflects a different set of applications. Six real and one synthetic HTTP traces, one for each pattern, are further identified and utilised to evaluate the performance of the proposed methods against the state-of-the-art approaches

Low-Dose Sertraline-Induced Erythema Multiforme in a Child

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98495/1/cap%2E2011%2E0061.pd

Genetic optimization of fuzzy membership functions for cloud resource provisioning

The successful usage of fuzzy systems can be seen in many application domains owing to their capabilities to model complex systems by exploiting knowledge of domain experts. Their accuracy and performance are, however, primarily dependent on the design of its membership functions and control rules. The commonly employed technique to design membership functions is to exploit the knowledge of domain experts. However, in certain application domains, the knowledge of domain experts are limited and therefore, cannot be relied upon. Alternatively, optimization techniques such as genetic algorithms are utilized to optimize the various design parameters of fuzzy systems. In this paper, we report a case study of optimizing the membership functions of a fuzzy system using genetic algorithm, which is an important part of our recently developed cloud elasticity framework. This work aims to improve the overall performance of the framework. Results obtained from this research work demonstrate performance improvement in comparison with our previous experimental settings

EFFECTS OF REMITTANCES ON PER CAPITA ECONOMIC GROWTH OF PAKISTAN

This study investigates the effects of remittances on per capita economicgrowth of Pakistan for the period 1976 to 2013. The Auto RegressiveDistributed Lag (ARDL) Bounds testing model was employed toexplore short run and long run liaison of remittances with per capitaeconomic growth. The analyses evidence statistically significantpositive long run and short run impacts of remittances on per capitaeconomic growth. Based upon the empirical results, this study suggeststhat government should formulate and adopt policies which canfurther motivate and enhance remittances inflow, and hence a morepromising economic growth

Hypovitaminosis D Causing Idiopathic Musculoskeletal Pain in Children

OBJECTIVES To determine the frequency of hypovitaminosis D in children presenting with Idiopathic musculoskeletal pain IMSP). METHODOLOGY The cross-sectional research was carried out at Peshawar’s Hayatabad Medical Complex’s Department of Pediatrics. The study duration was 6 months. The study comprised 151 patients with non-specific musculoskeletal pain who were tested for vitamin D levels to diagnose hypovitaminosis. RESULTS The age range of the participants was 3 to 15 years with a male predominance of 72.8%. The sample’s average the weight was above the 25 percentile. Hypovitaminosis D was found in 23.2%. Decreased sun exposure was documented in 82.85% of cases with hypovitaminosis. Hypocalcemia, hypophosphatemia and increased alkaline phosphatase were documented in 71.4%, 11.4% and 42.8% participants respectively with hypovitaminosis. CONCLUSION Hypovitaminosis D Is one of the risk factors for non-specific musculoskeletal pain but the current study revealed only 23.2% of participants had hypovitaminosis and inadequate sun exposure was a major risk factor for hypovitaminosis

Some differential subordination and superordination properties of symmetric analytic functions involving Noor integral operator

In this paper, we obtain some interesting properties of differential subordination and superordination for the classes of symmetric functions analytic in the unit disc, by applying Noor integral operator. We investigate several sandwich theorems on the basis of this theory

Footsteps in the fog: Certificateless fog-based access control

The proliferating adoption of the Internet of Things (IoT) paradigm has fuelled the need for more efficient and resilient access control solutions that aim to prevent unauthorized resource access. The majority of existing works in this field follow either a centralized approach (i.e. cloud-based) or an architecture where the IoT devices are responsible for all decision-making functions. Furthermore, the resource-constrained nature of most IoT devices make securing the communication between these devices and the cloud using standard cryptographic solutions difficult. In this paper, we propose a distributed access control architecture where the core components are distributed between fog nodes and the cloud. To facilitate secure communication, our architecture utilizes a Certificateless Hybrid Signcryption scheme without pairing. We prove the effectiveness of our approach by providing a comparative analysis of its performance in comparison to the commonly used cloud-based centralized architectures. Our implementation uses Azure – an existing commercial platform, and Keycloak – an open-source platform, to demonstrate the real-world applicability. Additionally, we measure the performance of the adopted encryption scheme on two types of resource-constrained devices to further emphasize the applicability of the proposed architecture. Finally, the experimental results are coupled with a theoretical analysis that proves the security of our approach

Board diversity and financial reporting quality: evidence from China

This study explores the relationship between board diversity and financial reporting quality (FRQ) in China, an emerging market, by using panel data techniques. Specifically, it investigates firms registered from 2005 to 2018. Board diversity is categorised into relation (i.e., gender and age), task (i.e., education, tenure, and experience), and overall board diversity (sum of relation and task diversities). Findings indicate that board diversity has a significant positive impact on FRQ. The relationship between board diversity and FRQ is also strong in non-stateowned firms and during noncrisis periods. Findings remain consistent after numerous robustness checks comprising instrumental approach, propensity score matching, generalised method of moment, lag of independent variables, Heckman two-step model, change analysis, and alternative FRQ measures. Overall, board diversity is found to be associated with corporate outcomes

Evaluation of Tomato Hybrids for Resistance against Tomato Mosaic Virus (ToMV)

Tomato mosaic virus (ToMV) drastically affects the tomato production worldwide. To deal with this problem, breeding of ToMV-resistant hybrids/varieties is the ultimate need and most successful approach. In wild tomato species, three dominant ToMV-resistant genes (Tm-1, Tm-2 and Tm-22 ) were identified and the World Vegetable Center developed few fresh market tomato lines resistant to ToMV by the introgression of these genes. Recently at Nuclear Institute for Agriculture and Biology, Faisalabad, Pakistan a breeding programme was initiated to develop high yielding and ToMV tolerant hybrids using these lines. Current study was performed to screen elite F1 hybrids carrying Tm gene along with their parents against ToMV using mechanical inoculation, confirmation of the virus using DAS-ELISA and marker assisted selection of hybrids. Out of 28 hybrids and 17 parent accessions/genotypes, eight hybrids and five accessions were found to be highly resistant and the virus was not detected in DAS-ELISA. Five hybrids were resistant, nine hybrids and four genotypes were tolerant, while the remaining six hybrids and eight genotypes were susceptible. For the confirmation of Tm-22 gene, the tomato hybrids and their parents were subjected to molecular analysis using cleaved amplified polymorphic sequence (CAPS) primers. The result of CAPS markers for the confirmation of Tm-22 gene was found consistent with phenotypic data of the inoculated tomato genotypes/ hybrids. Higher phenolic content, total soluble proteins, better CAT and SOD activities were positively correlated with resistance. Screening results based on phenotype, biochemical and molecular marker data indicate that hybrids carrying Tm-22 gene are good sources of resistance against ToMV

Discriminatory dissolution testing for liquisolid compacts containing a poorly water-soluble drug (Hydrochlorothiazide)

Drug release from liquisolid compacts is dependent on several variables and changes in experimental parameters, like drug loading and the type and quantity of the carrier material, which affect the dissolution rate, significantly. Therefore, a dissolution method is needed that can discriminate among in vitro release profiles of liquisolid compacts of varying nature. The objective of this study was to develop and validate a discriminatory dissolution testing method for liquisolid compacts of hydrochlorothiazide (HCTZ) to evaluate the effect of formulation and process variables on dissolution rate. Various experimental conditions were optimized, and the method was validated according to USP and ICH guidelines for different parameters like linearity, specificity, accuracy, precision, and stability of solution. Analysis of dissolution samples was carried out by high-performance liquid chromatography (HPLC). The discriminatory nature of the method was confirmed by determining dissolution rates of liquisolid compacts of HCTZ prepared with different load factors. A model-independent approach was applied for comparison of different dissolution profiles. Based on a screening study, USP apparatus I (basket method) was selected. The best in vitro dissolution profile was obtained using purified water containing Tween-80 (0.5% v/v) as the dissolution medium (900 mL), stirred at 75 rpm. Complete dissolution (99.83 ± 1.03%) was achieved within 60 min and dissolution media had no interference with sample analysis. HCTZ exhibited a linear response (r2 = 0.9974) in the selected dissolution medium and showed accurate results (98%–100%) in the concentration rage of 80%–120% of the dose. All validation parameters were found in acceptable range (%RSD > 2), and drug samples prepared in dissolution medium were stable for the specified period. Comparison of dissolution profiles in the official and developed media showed significant differences in f1 and f2 values. The developed dissolution test exhibited higher discriminative capacity in differentiating release profiles of HCTZ and can be applied during formulation development and quality control analysis of liquisolid compacts