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

Kinerja usahatani dan pemasaran terong ungu di Kabupaten Kupang, Nusa Tenggara Timur

Purple eggplant is becoming a popular plant cultivated, especially by small farmers in Kupang, East Nusa Tenggara (NTT). The purpose of this study was to measure the farm performance and marketing of purple eggplant. The research method used a survey method, using 46 sample farmers obtained by simple random sampling—the standard of eggplant cultivation measures farming performance. Business feasibility uses R/C ratio and marketing performance using Margin and Farmer Share (FS) and the marketing function. The results showed that the farming performance, as seen from the cultivation of purple eggplant, showed that every cultivation activity carried out by the farmer had almost fulfilled the ideal growth requirements according to the farmer's expectations with a production yield of 7.476 ton / 0.3ha. The income of purple eggplant farming is Rp. 3,033,840/the land area/planting season once. Purple eggplant farming is feasible, indicated by R/C> 1—marketing of purple eggplant through 4 marketing channels. The marketing system for eggplant is quite good, as indicated by the FS of 41.66%. Not many marketing functions are carried out at each stage so that not much-added value is generated. It is necessary to improve the purple eggplant cultivation system and increase the marketing function to increase the added value of purple eggplant

Effect of zero tillage and different weeding methods on grain yield of durum wheat in semi-arid regions

Received: September 28th, 2020 ; Accepted: December 1st, 2020 ; Published: December 10th, 2020 ; Correspondence: [email protected] high grain yield of wheat is limited by the dominance of weeds, particularly wild oat. Therefore, to improve wheat yield under these conditions, a field experiment was carried out in Maru Agricultural Research Station, Jordan during 2015–2016 and 2016–2017 to investigate yield response of two wheat varieties (Triticum durum L.) to different tillage and weeding treatments. The experimental design used was a split-split arrangement in a randomized complete block design with three replicates. Two-tillage treatments (conventional vs. zero tillage) were applied to the main plot, two wheat varieties to sub-plot, and five weeding methods (hand weeding, broadleaf + narrow leaf herbicide, broadleaf herbicide, narrow leaf herbicide, and controls) as a sub-sub-plot. The variety ‘Umqais’ had higher plant height, biological, grain, and straw yield than the variety ‘Sham’. Hand weeding slightly increased grain yield compared with mixed herbicides (the 2,4-D plus Antelope Clodinatop- propagyl). Furthermore, mixed herbicides presented a higher grain yield than using either single herbicide. The interaction between tillage systems and weeding methods was significant in both years. The highest (P < 0.05) straw yield (5,990 kg ha-1 ) was obtained by hand weeding under conventional tillage in the first season while the highest grain yield (2,005 kg ha-1 ) was obtained by hand weeding under zero tillage in the second season. Under all weed control treatments, the variety ‘Umqais’ had higher biological, grain, and straw yields than the variety ‘Sham’ in the second season indicating that variety ‘Umqais’ performed better under dry conditions. Our results confirmed the superior of zero tillage for increasing the grain yield of the variety ‘Umqais’, and for increasing the biological and straw yields of the variety ‘Sham’ under semi-arid rainfed conditions of Jordan

Characteristics of the summit lakes of Ambae volcano and their potential for generating lahars

Volcanic eruptions through crater lakes often generate lahars, causing loss of life and property. On Ambae volcano, recent eruptive activities have rather tended to reduce the water volume in the crater lake (Lake Voui), in turn, reducing the chances for outburst floods. Lake Voui occupies a central position in the summit caldera and is well enclosed by the caldera relief. Eruptions with significantly higher magnitude than that of 1995 and 2005 are required for an outburst. A more probable scenario for lahar events is the overflow from Lake Manaro Lakua bounded on the eastern side by the caldera wall. Morphology and bathymetry analysis have been used to identify the weakest point of the caldera rim from which water from Lake Manaro Lakua may overflow to initiate lahars. The 1916 disaster described on south-east Ambae was possibly triggered by such an outburst from Lake Manaro Lakua. Taking into account the current level of Lake Manaro Lakua well below a critical overflow point, and the apparently low potential of Lake Voui eruptions to trigger lahars, the Ambae summit lakes may not be directly responsible for numerous lahar deposits identified around the Island

Durability Assessment of Sustainable Mortar by Incorporating the Combination of Solid Wastes: An Experimental Study

The excessive mining of high-quality river sand for cement sand mortar resulted in environmental impacts and ecological imbalances. The present study aims to produce sustainable mortar by combining solid waste such as desert sand, stone dust, and crumb rubber to fully replace river sand. In addition, replacing cement with silica fume helps reduce the environmental carbon footprint. The present research prepared three types of mortar mixes: natural dune sand mortar (M1), natural dune sand stone dust crumb rubber mortar (M2), and natural dune sand stone dust crumb rubber silica fume mortar (M3). The developed mortar samples were examined at ambient and elevated temperatures of 100°C, 200°C, and 300°C for 120 minutes. Furthermore, 3 cycles of 12 hours each at freezing temperature (-10° ± 2°C) and crushed ice cooling (0° to -5°C) were also tested. Results of the study showed an increment in compressive strength values in M1, M2, and M3 mortar mixes (up to 200°C). Later, an abrupt drop in the compressive strength was noticed at 300°C in all mixes M1, M2, and M3, respectively. The mix M3 combinations resist heating impacts and perform significantly better than other mixes M1 and M2. Also, M3 combinations resist the cooling effect better than M1 and M2. It can be concluded that the mortar mix M3 with desert sand, stone dust, crumb rubber, and silica fume combination is considered the best mix for both heating and cooling resistance. Hence, the developed sustainable mortar M3 combination can be utilized in all adverse weather conditions. Doi: 10.28991/CEJ-2023-09-11-09 Full Text: PD

Seatbelt syndrome associated with an isolated rectal injury: case report

Seatbelt syndrome is defined as a seatbelt sign associated with a lumbar spine fracture and a bowel perforation. An isolated rectal perforation due to seatbelt syndrome is extremely rare. There is only one case reported in the Danish literature and non in the English literature. A 48-year old front seat restrained passenger was involved in a head-on collision. He had lower abdominal pain and back pain. Seatbelt mark was seen across the lower abdomen. Initial trauma CT scan was normal except for a burst fracture of L5 vertebra which was operated on by internal fixation on the same day. The patient continued to have abdominal pain. A repeated abdominal CT scan on the third day has shown free intraperitoneal air. Laparotomy has revealed a perforation of the proximal part of the rectum below the recto sigmoid junction. Hartmann's procedure was performed. The abdomen was left open. Gradual closure of the abdominal fascia over a period of two weeks was performed. Postoperatively, the patient had temporary urinary retention due to quada equina injury which resolved 10 months after surgery. The presence of a seatbelt sign and a lumbar fracture should raise the possibility of a bowel injury

THE ECONOMIC BENEFITS OF KNOWLEDGE VALIDATION OF ERP TO LOW TECH SMES

Abstract: Knowledge Validation is a challenge in Small to Medium Sized Enterprises (SMEs), as most of the available information is held in people&apos;s minds as tacit knowledge, or saved on each employees PC without sharing or common validation. This case study is based on a company in Leicester who installed an enterprise resource planning (ERP) system after two previous failed trials with different type of software. The underlying reasons for the problems were due to the distributed and tacitly held knowledge where the assumptions in one part of the company were inconsistent with other parts. The research goes through three years of ERP implementation and analyses the main problem of validating knowledge in more detail and identifies the consequences of failing to do this. It also describes the potential economic benefits for installing enterprise resource planning system in SMEs and investigates the claim of ERP vendors that their ERP solutions increase the performance of their customers, increase profitability and efficiency of work processes. It discusses the effects of ER