291 research outputs found

    Developing a user-centric distributed middleware for SLA monitoring in SaaS cloud computing using RESTful services

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    One of the most important discussions in the cloud computing field is user satisfaction with the associated services. It is important to maintain trusted relationships between clients and providers, for customers who pay subscriptions to receive these services in a timely and accurate manner. Despite the overwhelming advantages of cloud services, clients sometimes have problems in service outage and resource failure. This is due to the failures that can happen in cloud servers, which cause outages to the received services. For example, the failure of Microsoft Office 365 on 18th of January 2016, caused email disruption which lasted for many days. New measures are needed to ensure that the contract signed between the two parties, known as a Service Level Agreement (SLA) has been adhered to. Measuring the quality of cloud computing provision from the client’s point of view is, therefore, essential in order to ensure that the service conforms to the level specified in the agreement; this is usually referred to as Quality of Experience. In recent years, there has been an increase shift in using Simple Object Access Protocol (SOAP) to Representational State Transfer (REST) technology as an alternative technology in cloud applications APIs development. However, there is a penchant in most of cloud monitoring solutions to use SOAP protocol in managing the monitoring process. This trend has drawn the attention to the need for using REST technology in transferring the monitored data between the provider side and the client side. This thesis addresses the problem of monitoring the quality of Software as a Service from the users’ perspective, and the need for developing a lightweight middleware for delivering the monitored data in Software as a Service cloud computing. The aim of this research is to propose a user centric approach for monitoring Software as a Service in cloud computing, and to reduce the overhead caused by the monitoring process. In order to achieve this aim, a user centric middleware capable of monitoring the Quality of Experience has been developed. The developed middleware is a Service Oriented middleware which uses RESTful web services and provides the monitoring process as an add-on service. A new approach was developed for embedding the SLA parameters in REST services through extending the HTTP messages and exploiting the HEAD and OPTIONS methods to transmit the monitored data and to send notifications about anySLA violations. This reduces the need to exchange extra monitoring messages between the two parties, and hence reduces the communication overhead. Furthermore, the estimation of the user satisfaction was implemented by developing a decision making approach to estimate the Quality of Experience value and to predict the effect of the SLA parameters and the Quality of Service (QoS) on the user satisfaction. Fuzzy logic techniques were employed in the decision making process.The developed middleware is called MonSLAR, for Monitoring SLA for Restful services in SaaS cloud computing environments. The middleware was implemented using the Java programming language, and tested successfully in a cloud environment to prove the proposed solution’s capability of transmitting the data using the REST methods, in addition to providing automated and real time feedback. MonSLAR uses a distributed monitoring architecture, which allows SLA parameters to be embedded in the requests and responses of the REST protocol. The proposed middleware was evaluated by measuring the overhead caused by using REST technology in terms of response time and message size and compared to existing techniques. The results revealed that the message size overhead of using REST is approximately five times less than the message size overhead caused by SOAP. Furthermore, the response time overhead of the monitoring process is comparable to the overhead caused by the available monitoring frameworks. To sum up, the proposed middleware will help to strengthen the relationship between the client and the provider by using real time notifications to the client about any degradation in the cloud services, using a lightweight middleware

    Water use vs. socio-economic factors in a water stressed urban area having economic affluence

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    The paper presents household water-use data collected from a water use survey in an urban area located in a water stressed region in the Middle East. The purpose of the survey was to investigate the effect and relationships of water shortage, economic effluence and socioeconomic attributes of house holds on per capita water use in the area. Results indicated wide variation of water uses in smaller districts of the urban area. In small areas socioeconomic factors are significantly related to per capita water use. However, when total urban area is considered, same set of factors do not show any meaningful relationship to per capita water use. Water use in summer is about 2-6 times more than that in winter. Over all per capita water use in the area is recorded to be one the highest in the world

    Techno-Economic Feasibility to Generate Electricity by Using PSO Technique for the Urban City in Iraq: Case Study

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    For developing nations such as Iraq, electricity access in rural areas, especially those which are remote, is limited. Thus, the present study explores the electrical needs of the city of Zerbattiya, Iraq. The proposed system’s components include solar panels, wind turbines, diesel generators, and batteries. This research proposes a techno-economically feasible and optimal sizing for each component to generate electricity for the village. Particle swarm optimization (PSO) algorithm was used in this research by using MATLAB. The ideal setting of a hybrid renewable energy system (HRES) is achieved by considering the lowest possible COE with the highest reliability and possible value of renewable energy factors. Reliability is gauged on the basis of “loss of power supply probability†(LPSP). Results showed that the respective optimal values for NPV (30), NWT (30), NDG (3), NBT (281), COE (US$0.142), LPSP (0.002085), reliability (99.791) and renewable factors (21.42%). The findings further demonstrate that the algorithm was able to achieve optimal solutions to reduce overall cost, quickly and accurately. In conclusion, implementation of HRES was found to be an apt method of meeting electrical needs of remote rural areas, not only in Iraq, but also other developing nations with similar climates

    Effect of in ovo injection of epigallocatechin-3 gallate and oleuropein on hatching, productive and physiological aspects of broiler chicks exposed to short heat stress

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    This study was aimed to investigate the influence of in ovo injection (IO) into air cell (AC) or yolk sac (YS) of epigallocatechin-3 gallate (EG) and oleuropein (OL) as antioxidants on hatching, physiological and productive performance of heat-stressed chicks. 840 fertile eggs were chosen for IO on 12th day of incubation. Eggs were divided into 7 groups within 4 replications each as follows: negative control (NC) without IO and other groups involved IO of 100 μl distilled water and 5 mg each of EG and OL in both AC and YS sites of egg. After hatching, chicks were exposed to heat stress for 24 h and raised for 42 d. Compared with NC, the results revealed that main effect of IO with EG and OL increased (p≤0.05) hatchability and decreased deformed chicks and serum levels of glucose, cholesterol, aspartate aminotransferase, corticosterone and heat shock protein 70 with enhancing feed efficiency, superoxide dismutase, glutathione peroxidase and thyroxine in serum or liver. High chick length and relative chick weight with low serum protein carbonyl and feed intake were recorded (p≤0.05) by EG. Low rectal temperature and heterophil to lymphocyte ratio with high body weight were recordered (p≤0.05) by OL. No mainly altered effects between both IO sites on most variables measured. However, there were significant influences among interactive treatments which related to in ovo injected substance in an injection site-dependent manner. It is concluded that improved hatchability, physiological and productive characteristics of heat-stressed chicks were achieved by IO of EG and OL

    Glimpse on Hemostatic Changes Produced By Plasmapheresis.

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    Background: Aphaeresis is a term that means to separate or to take away. The basic idea of aphaeresis is efficient removal of a circulating cellular blood component, either cells (Cytopheresis) or plasma solute (plasmapheresis, plasma exchange).Thus, the treatment goal of aphaeresis is to remove the circulating cell or substance directly responsible for the disease process. Acceleration and development of aphaeresis applications had taken place with the arrival of automated cell separators in 1970s that ensure selectively removal of one or more of blood components from the blood and return the remainder to the individual. Plasmapheresis is separation of plasma from blood cells which are returned to the body. It is accompanied by multiple changes in haemostatic system. As many coagulation factors are removed during procedure, changes in selective parameters: Prothrombin Time (PT), Partial Thromboplastin Time (PTT), Thrombin Time (TT), Fibrinogen (FNG) & platelets count are found when the replacement fluids devoid from coagulation factor are used. Patients and Methods: This clinico-haematological study conducted during a period of six months, from February 2004 to July 2004 at the National Blood Transfusion Center (NBTC) in Baghdad & 50 patients underwent Therapeutic Plasma Exchange (TPE) for various disorders with the use of two types of automated blood cell separators (Haemonetics MCS + which represent an intermittent flow centrifugation technique – IFC & Fresenius AS. TEC 204 which represent the continuous flow centrifugation technique - CFC) in this study, but no instrument type influenced the coagulation screening tests. Results: The changes in all selective parameter: Prothrombin Time (PT), Partial Thromboplastin Time (PTT), Thrombin Time (TT), Fibrinogen (FNG), Platelets count, Haemoglobin (Hb) and Packed Cell Volume (PCV) were significant after Therapeutic Plasma Exchange (TPE). There was no significant difference in changes in crystalloid group from that in Fresh Frozen Plasma group. In crystalloid group, significant correlation was observed between Prothrombin Time (PT), Activated Partial Thromboplastin Time (APTT), Thrombin Time (TT) & volume of Plasma Exchanged (PE) /session, while spacing between sessions and the number of sessions is significantly correlated with Thrombin Time (TT). Plasma fibrinogen concentration and platelets count were decreased in the patients included in our current study. Conclusion: There is no significant difference in changes in haemostatic system whether crystalloid or diluted Fresh Frozen Plasma (FFP) was used as replacement fluid. Thus, crystalloid, solution devoid of coagulation material can be used as a replacement fluid in the Therapeutic Plasma Exchange (TPE) if the volume of Plasma Exchanged (PE) is small. These results are of vital importance from the practical & public health point of view in minimizing the usage of blood components((i.e. Fresh Frozen Plasma (FFP) which is a potential source of Transfusion Transmissible Infections (TTIs) worldwide)) & replaced by crystalloid solution as a safer replacement fluid substitute in Therapeutic Plasma Exchange (TPE) process

    Alloimmunization in Transfusion Dependent Thalassaemic Patients.

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    Background: Life-long red blood cells (RBCs) transfusion remains the main treatment for severe cases of thalassaemia. The development of anti-RBC antibodies (alloantibodies and for autoantibodies) can significantly complicate transfusion therapy. Some alloantibodies are hemolytic and may cause, though not invariably, hemolytic transfusion reactions and limit the availability of further safe transfusion. Erythrocyte autoantibodies appear less frequently in blood cross match. Patients and methods: This is a descriptive study ducted at Al-Karama Thalassaemia Center in Baghdad .The sampling was done from September 2005 to April 2006 and all patients were diagnosed as Thalassaemia Major according to the hemoglobin electrophoresis results were included in the study (60 patients). Antibodies identification was carried out on serum employing commercial two cell panel, using standardized blood bank methods. If the patients were found to have irregular red cell alloantibodies, then the antibodies identification was performed by indirect coombs test using 18 panel cells. Results: Sixty thalassaemic patients were included in the study, 35 patients were males and 25 females. The age of patients ranged from 18 months to 33 years (median 25.2 7). Irregular red cell antibodies were found in 9 patients (15%). Mean age of patients who developed red cell antibodies was 25.2±7.0 years. Two patients developed autoantibodies (3.3%) and seven patients developed alloantibodies (11.7%).Six patients developed single antibodies (10%) while 3 patients developed multiple antibodies (5.0%). Total anti-k was found in 4 patients (6.7%), two patients had anti-k 1 and two patients had anti-k2. The higher rate of alloimmunization was in the rhesus Rh system, which was detected in (8.3%) 5 patients (one patient developed anti-D, one patient developed anti-c and 3 patients developed total anti-e). while total anti-M presented in 3 patients(5.09%)while one patient developed anti-Lea (1.7%).  Conclusion: We concluded that there is a relatively high rate of alloimmunization in our set of patients when compared to data from Iraq geographic region. However, more data required from various other large centers in Iraq. It is recommended that red cell alloimmunization should not be overlooked in patients with B- thalassaemia major receiving regular blood transfusion. Those patients with Thalassaemia Major repeatedly suffer from hemolytic transfusion reaction or not being able to maintain hemoglobin at desired level in spite of regular transfusion due to the presence of irregular alloantibodies in their circulation. Proper blood cross matching, regular screening, detection & identification of the red blood cell alloantibodies would add towards the better management of these patients & reduce the chance of development of these irregular antibodies & other possible additional alloantibodies

    Modelling oxygen capillary supply to striated muscle tissues

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    The ability to characterise functional capillary supply (FCS) plays a key role in developing effective therapeutic interventions for numerous pathological conditions, such as chronic ischaemia in skeletal or cardiac muscle. Detailed tissue geometry, such as muscle fibre size, has been incorporated into indices of FCS by considering the distribution of Voronoi tessellations (‘capillary domains’) generated from vessel locations in a plane perpendicular to muscle fibre orientation, implicitly assuming that each Voronoi polygon represents the area of supply of its enclosed capillary. However, to assess the capacity of FCS in muscle, we are naturally led to use a modelling framework that can account for the local anatomic and metabolic heterogeneities of muscle fibres. Such a framework can be used to explore the validity of the Voronoi polygon representation of FCS regions while also providing a general platform for robust predictions of FCS
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