An efficient processor allocation strategy that maintains a high degree of contiguity among processors in 2D mesh connected multicomputers

Two strategies are used for the allocation of jobs to processors connected by mesh topologies: contiguous allocation and non-contiguous allocation. In non-contiguous allocation, a job request can be split into smaller parts that are allocated to non-adjacent free sub-meshes rather than always waiting until a single sub-mesh of the requested size and shape is available. Lifting the contiguity condition is expected to reduce processor fragmentation and increase system utilization. However, the distances traversed by messages can be long, and as a result the communication overhead, especially contention, is increased. The extra communication overhead depends on how the allocation request is partitioned and assigned to free sub-meshes. This paper presents a new Non-contiguous allocation algorithm, referred to as Greedy-Available-Busy-List (GABL for short), which can decrease the communication overhead among processors allocated to a given job. The simulation results show that the new strategy can reduce the communication overhead and substantially improve performance in terms of parameters such as job turnaround time and system utilization. Moreover, the results reveal that the Shortest-Service-Demand-First (SSD) scheduling strategy is much better than the First-Come-First-Served (FCFS) scheduling strategy

Non-contiguous processor allocation strategy for 2D mesh connected multicomputers based on sub-meshes available for allocation

Contiguous allocation of parallel jobs usually suffers from the degrading effects of fragmentation as it requires that the allocated processors be contiguous and has the same topology as the network topology connecting these processors. In non-contiguous allocation, a job can execute on multiple disjoint smaller sub-meshes rather than always waiting until a single sub-mesh of the requested size is available. Lifting the contiguity condition in non-contiguous allocation is expected to reduce processor fragmentation and increase processor utilization. However, the communication overhead is increased because the distances traversed by messages can be longer. The extra communication overhead depends on how the allocation request is partitioned and allocated to free sub-meshes. In this paper, a new non-contiguous processor allocation strategy, referred to as Greedy-Available-Busy-List, is suggested for the 2D mesh network, and is compared using simulation against the well-known non-contiguous and contiguous allocation strategies. To show the performance improved by proposed strategy, we conducted simulation runs under the assumption of wormhole routing and all-to-all communication pattern. The results show that the proposed strategy can reduce the communication overhead and improve performance substantially in terms of turnaround times of jobs and finish times

The effect of real workloads and stochastic workloads on the performance of allocation and scheduling algorithms in 2D mesh multicomputers

The performance of the existing non-contiguous processor allocation strategies has been traditionally carried out by means of simulation based on a stochastic workload model to generate a stream of incoming jobs. To validate the performance of the existing algorithms, there has been a need to evaluate the algorithms' performance based on a real workload trace. In this paper, we evaluate the performance of several well-known processor allocation and job scheduling strategies based on a real workload trace and compare the results against those obtained from using a stochastic workload. Our results reveal that the conclusions reached on the relative performance merits of the allocation strategies when a real workload trace is used are in general compatible with those obtained when a stochastic workload is used

A performance comparison of the contiguous allocation strategies in 3D mesh connected multicomputers

The performance of contiguous allocation strategies can be significantly affected by the distribution of job execution times. In this paper, the performance of the existing contiguous allocation strategies for 3D mesh multicomputers is re-visited in the context of heavy-tailed distributions (e.g., a Bounded Pareto distribution). The strategies are evaluated and compared using simulation experiments for both First-Come-First-Served (FCFS) and Shortest-Service-Demand (SSD) scheduling strategies under a variety of system loads and system sizes. The results show that the performance of the allocation strategies degrades considerably when job execution times follow a heavy-tailed distribution. Moreover, SSD copes much better than FCFS scheduling strategy in the presence of heavy-tailed job execution times. The results also show that the strategies that depend on a list of allocated sub-meshes for both allocation and deallocation have lower allocation overhead and deliver good system performance in terms of average turnaround time and mean system utilization

Inhibition of allogeneic inflammatory responses by the Ribonucleotide Reductase Inhibitors, Didox and Trimidox

<p>Abstract</p> <p>Background</p> <p>Graft-versus-host disease is the single most important obstacle facing successful allogeneic stem cell transplantation (SCT). Even with current immunosuppressive therapies, morbidity and mortality rates are high. Current therapies including cyclosporine A (CyA) and related compounds target IL-2 signaling. However, although these compounds offer great benefit, they are also associated with multiple toxicities. Therefore, new compounds with a greater efficacy and reduced toxicity are needed to enable us to overcome this hurdle.</p> <p>Methods</p> <p>The allogeneic mixed lymphocyte reaction (MLR) is a unique <it>ex vivo </it>method to study a drug's action on the initial events resulting in T-cell activation and proliferation, synonymous to the initial stages of tissue and organ destruction by T-cell responses in organ rejection and Graft-versus-host disease. Using this approach, we examined the effectiveness of two ribonucleotide reductase inhibitors (RRI), Didox and Trimidox, to inhibit T-cell activation and proliferation.</p> <p>Results</p> <p>The compounds caused a marked reduction in the proliferative responses of T-cells, which is also accompanied by decreased secretion of cytokines IL-6, IFN-γ, TNF-α, IL-2, IL-13, IL-10 and IL-4.</p> <p>Conclusions</p> <p>In conclusion, these data provide critical information to justify further investigation into the potential use of these compounds post allogeneic bone marrow transplantation to alleviate graft-versus-host disease thereby achieving better outcomes.</p

ƴ-Selective directed catalytic asymmetric hydroboration of 1,1-disubstituted alkenes

Directed catalytic asymmetric hydroborations of 1,1-disubstituted alkenes afford ƴ -dioxaborato amides and esters in high enantiomeric purity (90–95% ee)

Assessing the Psychological and Social Impacts of the Refugee Crisis on Members of the Refugees-Hosting Community: A Survey Study of the Jordan Community

ملخص: هدف البحث الحالي إلى تقييم الآثار النفسيّة والاجتماعية النّاتجة عن أزمة اللجوء لدى أفراد المجتمعات المستضيفة للاجئين، وقد تكوّنت عيّنة الدّراسة من (3152) فرداً، تمّ اختيارهم بالطريقة المتيسرة.ولتحقيق هدف الدراسة، تم تطوير مقياس الآثار النفسية والاجتماعية الذي تألف من (42) فقرة بحيث وزّعتْ على مجالين هما: (الآثار النفسية، والآثار الاجتماعية).وأظهرت نتائج الدراسة أنّ مستوى الآثار النفسية كان منخفضاً؛ بينما جاء مستوى الآثار الاجتماعية بدرجة متوسطة، كما أظهرت النتائج وجود فروق ذات دلالة إحصائية في الآثار النفسية تعزى لمتغيرات الجنس، العمر، وطبيعة العمل، وعدم وجود فروق دالة إحصائيًا تعزى لمتغير مستوى التعليم. في حين أظهرت النتائج وجود فروق ذات دلالة إحصائية للآثار الاجتماعية تعزى لمتغيرات الجنس، والعمر، وعدم وجود فروق دالة إحصائيًا تعزى لمتغيرات مستوى التعليم، وطبيعة العمل. وأوصى الباحثون بضرورة تبني نهج مؤسسي تخصصي للاهتمام بالصحة النفسية لأفراد المجتمع الأردني، والعمل على استحداث برامج للتأهيل المهني والاجتماعي للباحثين عن عمل.Abstract: The current research aimed to assess the psychological and social impacts on Jordanian. The Convenience sample consisted of (3152)To achieve the aim of the study, measure were developed to the psychosocial and social impact scale, which consists of (42) items, The results shown that the psychological effects are low, and social effects are moderate. The results also shown a significance difference on psychological effects to gender and age and work, but there were no significance differences on education level. The results also shown a significance difference on social effects to gender and age, but there is no a significance differences on education level and work. So, The researchers recommend to adopting a specialized institutional approach to take care of Jordanian's mental health, and working on rehabilitating the unemployed individuals functionally, psychologically and socially

Utilization Potential of Glass Fiber and Crumbled Rubber as Subgrade Reinforcement for Expansive Soil

Due to its high potential for volume change, expansive soil is a problematic building material that can cause harm to road infrastructure. The purpose of this study is to examine the effect of glass fiber and rubber on the properties of expansive soil and their suitability as subgrade reinforcement in road applications. For different percentages of glass fiber and rubber in the soil, the Maximum Dry Density (MDD), Optimum Moisture Content (OMC), and CBR were measured. The results demonstrated that the incorporation of glass fiber and rubber improved the soil's properties. With increasing fiber and rubber content, the MDD and CBR increased, while the OMC decreased. In addition, the strength of the reinforced soil was significantly greater than that of the unreinforced soil. The research indicates that the addition of glass fiber and rubber can improve the efficacy of expansive soil as subgrade reinforcement in road applications.   Doi: 10.28991/HEF-2023-04-03-06 Full Text: PD

Evaluation of gait symmetry in poliomyelitis subjects : Comparison of a conventional knee ankle foot orthosis (KAFO) and a new powered KAFO.

Background: Compared to able-bodied subjects, subjects with post polio syndrome and poliomyelitis demonstrate a preference for weight-bearing on the non-paretic limb, causing gait asymmetry. Objectives: The purpose of this study was to evaluate the gait symmetry of the poliomyelitis subjects when ambulating with either a drop- locked knee ankle foot orthosis (KAFO) or a newly developed powered KAFO. Methods: Seven subjects with poliomyelitis who routinely wore conventional KAFOs participated in this study, and received training to enable them to ambulate with the powered KAFO on level ground, prior to gait analysis. Results: There were no significant differences in the gait symmetry index (SI) of step length (P=0.085), stance time (P=0.082), double limb support time (P=0.929) or speed of walking (p=0.325) between the two test conditions. However, using the new powered KAFO improved the SI in step width (P=0.037), swing time (P=0.014), stance phase percentage (P=0.008) and knee flexion during swing phase (p≤0.001) compared to wearing the dropped locked KAFO. Conclusion: The use of a powered KAFO for ambulation by poliomyelitis subjects affects gait symmetry in the base of support, swing time, stance phase percentage and knee flexion during swing phase

Cyclin dependent kinase inhibitor 3 (CDKN3) upregulation is associated with unfavorable prognosis in clear cell renal cell carcinoma and shapes tumor immune microenvironment: A bioinformatics analysis

Cell cycle regulatory proteins plays a pivotal role in the development and progression of many human malignancies. Identification of their biological functions as well as their prognostic utility presents an active field of research. As a continuation of the ongoing efforts to elucidate the molecular characteristics of clear cell renal cell carcinoma (ccRCC); we present a comprehensive bioinformatics study targeting the prognostic and mechanistic role of cyclin-dependent kinase inhibitor 3 (CDKN3) in ccRCC. The ccRCC cohort from the Cancer Genome Atlas Program was accessed through the UCSC Xena browser to obtain CDKN3 mRNA expression data and their corresponding clinicopathological variables. The independent prognostic signature of CDKN3 was evaluated using univariate and multivariate Cox logistic regression analysis. Gene set enrichment analysis and co-expression gene functional annotations were used to discern CDKN3-related altered molecular pathways. The tumor immune microenvironment was evaluated using TIMER 2.0 and gene expression profiling interactive analysis. CDKN3 upregulation is associated with shortened overall survival (hazard ratio [HR] = 2.325, 95% confident interval [CI]: 1.703–3.173, P < .0001) in the Cancer Genome Atlas Program ccRCC cohort. Univariate (HR: 0.426, 95% CI: 0.316–0.576, P < .001) and multivariate (HR: 0.560, 95% CI: 0.409–0.766, P < .001) Cox logistic regression analyses indicate that CDKN3 is an independent prognostic variable of the overall survival. High CDKN3 expression is associated with enrichment within the following pathways including allograph rejection, epithelial–mesenchymal transition, mitotic spindle, inflammatory response, IL-6/JAK/STAT3 signaling, spermatogenesis, TNF-α signaling via NF-kB pathway, complement activation, KRAS signaling, and INF-γ signaling. CDKN3 is also associated with significant infiltration of a wide spectrum of immune cells and correlates remarkably with immune-related genes. CDKN3 is a poor prognostic biomarker in ccRCC that alters many molecular pathways and impacts the tumor immune microenvironment.Scopu