Load Allocation Research Articles

Coded Computation Across Shared Heterogeneous Workers With Communication Delay

Distributed computing enables large-scale computation tasks to be processed over multiple workers in parallel. However, the randomness of communication and computation delays across workers causes the straggler effect, which may degrade the performance. Coded computation helps to mitigate the straggler effect, but the amount of redundant load and their assignment to the workers should be carefully optimized. In this work, we consider a multi-master heterogeneous-worker distributed computing scenario, where multiple matrix multiplication tasks are encoded and allocated to workers for parallel computation. The goal is to minimize the communication plus computation delay of the slowest task. We propose worker assignment, resource allocation and load allocation algorithms under both dedicated and fractional worker assignment policies, where each worker can process the encoded tasks of either a single master or multiple masters, respectively. Then, the non-convex delay minimization problem is solved by employing the Markov's inequality-based approximation, Karush-Kuhn-Tucker conditions, and successive convex approximation methods. Through extensive simulations, we show that the proposed algorithms can reduce the task completion delay compared to the benchmarks, and observe that dedicated and fractional worker assignment policies have different scopes of applications.

Water Quality Management at a Critical Checkpoint by Coordinated Multi-Catchment Urban-Rural Load Allocation

Water Quality Management at a Critical Checkpoint by Coordinated Multi-Catchment Urban-Rural Load Allocation

Water Quality Management at a Critical Checkpoint by Coordinated Multi-Catchment Urban-Rural Load Allocation

Water Quality Management at a Critical Checkpoint by Coordinated Multi-Catchment Urban-Rural Load Allocation

The Effects of the Model Predictive Controller Compared to the LQR Controller on the Optimal Distribution of the Suitable Load and the Creation of Balance in Microgrids

Background and Objectives: Distributed generation (DG) sources are modeled using an ideal DC voltage source connected to the microgrid via voltage source converters (VSCs). Model predictive control presents a distinct method for energy processing.Methods: In this method, the electric power converter is considered a power amplifier with a discrete and nonlinear structure. Therefore, unlike linear control methods, the discrete and nonlinear nature of the converter is considered in this method. In this paper, the distributed model predictive controller was selected from among different methods of load allocation among DG sources due to its more advantages compared to the linear quadratic regulator (LQR) controller.Results: It has been Proposed that we could obtain better results in predictive control, utilizing similarity transform in the state matrix and its modification. In this research, all the simulations have been performed in the MATLABSimpower environment of MATLAB software.Conclusion: Moreover, to demonstrate the superior performance of the model predictive controller compared to the LQR controller, both performance modes of the microgrid, namely the grid-connected and islanding modes, have been considered.

Steam-Water Modelling and the Coal-Saving Scheduling Strategy of Combined Heat and Power Systems

China aims to peak carbon emissions by 2030. As a result, small-scale coal-fired combined heat and power (CHP) units and self-provided units are gradually shut down, and large-scale coal-fired CHP units are a solution to undertake the industrial heat loads. From the perspective of the industrial heat load allocation during the non-heating season, the problems regarding the coal-saving scheduling strategy of coal-fired CHP units are addressed. The steam-water equations of CHP units are established to analyze the heat-power coupling characteristics. The energy utilization efficiency, exergy efficiency and the coal consumption are analyzed. The optimization model of saving coal consumption is established and the adaptive mutation particle swarm optimization (AMPSO) is introduced to solve the above model. The 330 MW coal-fired CHP unit is taken as an example, and the results show that for the constant main flow rate, each increase of 1 t/h industrial steam extraction will reduce the power output by about 0.321 MW. The energy utilization efficiency and the exergy are mainly influenced by industrial steam supply and the power load, respectively. For the CHP system with two parallel CHP units, the unequal allocation of industrial heat load between two units saves more coal than equal allocation. The coal consumption can be reduced when the unit with lower power load undertakes more industrial heat load. In the typical day, the total coal consumption after optimization is 3203.92 tons, a decrease of 14.66 tons compared to the optimization before. The two CHP units in the case can benefit about 5,612,700 CHY extra in one year.

EFISIENSI BIAYA MELALUI PEMANFAATAN TRANSPORTATION METHOD

This study was conducted to find out whether the transportation costsof cement at PT. Bosowa in 2020 to distribute cement from Palaran andBalikpapan storage warehouses to markets that require it, namely Handil,Samboja, Samarinda and Spaku, can be saved or streamlined by usingtransportation methods. It also proves whether the temporary load allocationusing the North West Corner Method has provided the optimum solution orwhether it must be accompanied by optimal testing.The theoretical basis used in this study is management accountingtheory which emphasizes cost efficiency and transportation theory whichpresents transportation methods.The analytical tool used in this study is the North West Corner Method(NWCM) to allocate temporary loads while the optimal allocation uses theStepping Stone Method.The findings of this study indicate that the use of the North WestCorner Method of temporary load allocation does not necessarily result inoptimal load allocation and determination of transportation costs, thereforeit is necessary to test the temporary load allocation using the stepping stonemethod or the modified distribution method. Transportation Method isproven to be able to streamline cement transportation costs at PT. BosowaSamarinda branch in 2020.

The Water Quality Improvement through Two Pollutant Load Allocation Methods in Gehu Lake, China

AbstractDue to many industrial and domestic pollution sources gathered around Gehu Lake and the lack of effective reduction measures, the ammonia nitrogen and total phosphorus in a large area of th...

An adaptive surrogate-based, multi-pollutant, and multi-objective optimization for river-reservoir system management

Integrated management of quality and quantity of river-reservoir water can provide comprehensive information to manage river-reservoir water resources. However, high computational bottlenecks have prevented such management from being applicable in real-world systems. Accordingly, in the present study, we proposed a multi-objective optimization algorithm based on modular support vector regression (SVR) in which several small sub-SVR modules trained through an efficient adaptive procedure cooperate to solve a large-scale problem related to integrated management of quality and quantity of river-reservoir. The performance of the proposed approach was evaluated through an adaptive surrogate-based simulation-optimization (ASBSO) framework under reservoir selective withdrawal scheme (SWS) in Ilam integrated River-Reservoir. The ASBSO framework provided a set of non-dominated optimal solutions to alleviate Ilam River water quality standard violations, enhance Ilam Reservoir outflow water quality, and maximize the downstream water supply satisfaction. The analysis of the Pareto-front indicated that the implementation of MPWLA (multi-pollutant waste load allocation) programs at any level could alleviate the water quality problems in Ilam Reservoir. Furthermore, the reservoir water storage in the regular patterns to meet downstream water demands have resulted in water quality deteriorations in Ilam Reservoir. The results obtained from examining the proposed approach, showed that integrated river-reservoir system management improved water quality in the range from 7 to 28% at the checkpoints of the Gol-Gol Branch of Ilam River and in the range from 5 to 21% at Ilam Reservoir outflow.

Comparison of Theta Beta Ratio in children with Attention deficit/hyperactive disorder and specific Learning Disorder during active EEG

Introduction: Theta-Beta Ratio (TBR) has been claimed as a biomarker to diagnose Attention Deficit and Hyperactivity Disorder (ADHD). However, the effectiveness of this index to differentiate between different groups of disorders is still under discussion. The primary purpose was to determine to what extent active TRB can differentiate between children with ADHD and specific Learning Disorder (sLD) as the most common comorbid disorder. Methods: Two groups of school-aged children with sLD (N=15) and ADHD (N=15) were diagnosed through a process of clinical interview and observation. Electroencephalography (EEG) was recorded in both groups during active condition. The implemented cognitive task was the visual continuous performance task (VCPT). TBR in sites of CZ and Fz, and cognitive measures of VCPT were calculated in the aforementioned groups. Results: There was no significant differences in cognitive measures (containing Commission, Omission, Reaction Time, and Variability of Reaction Times) shown in two matched groups of children with sLD and ADHD. According to TBR, two groups demonstrated no significant results in comparison. Conclusion: TBR cannot be considered as a reliable biomarker to differentiate between those groups of psychological disorders that contain primary cognitive deficits and require the allocation of attention and working memory loads.

An adaptive metamodelling for multipollutant waste load allocation in a river–reservoir system; hydrodynamic simulation–optimization

AbstractDischarge of nutrient load from aquaculture activities may pose an eutrophication risk to receiving waterbodies. In this study, monthly multipollutant waste load allocation (MPWLA) programmes are developed to determine the required treatment levels of pollutants released into a river–reservoir system. The objectives of the MPWLA programmes consist of minimizing the total wastewater treatment cost, maximizing the profit from fish production and improving water quality index. The CE‐QUAL‐W2 model with artificial neural networks is linked to the multiobjective particle swarm optimization algorithm to obtain the trade‐off surface in a surrogate‐based simulation–optimization framework. To tackle the ambiguities in quantifying the discharged pollutants, fuzzy membership functions are defined. The application of the proposed MPWLA programmes in the Behesht‐Abad River‐Reservoir system, Iran, has led to a reduction in phosphate concentration more than 3%, enhancement in dissolved‐oxygen levels in the ranges of 2% to 11.6%, and alleviation of Carlson Index between 3 to 7 units.

Comparison of Deterministic and Statistical Models for Water Quality Compliance Forecasting in the San Joaquin River Basin, California

Model selection for water quality forecasting depends on many factors including analyst expertise and cost, stakeholder involvement and expected performance. Water quality forecasting in arid river basins is especially challenging given the importance of protecting beneficial uses in these environments and the livelihood of agricultural communities. In the agriculture-dominated San Joaquin River Basin of California, real-time salinity management (RTSM) is a state-sanctioned program that helps to maximize allowable salt export while protecting existing basin beneficial uses of water supply. The RTSM strategy supplants the federal total maximum daily load (TMDL) approach that could impose fines associated with exceedances of monthly and annual salt load allocations of up to $1 million per year based on average year hydrology and salt load export limits. The essential components of the current program include the establishment of telemetered sensor networks, a web-based information system for sharing data, a basin-scale salt load assimilative capacity forecasting model and institutional entities tasked with performing weekly forecasts of river salt assimilative capacity and scheduling west-side drainage export of salt loads. Web-based information portals have been developed to share model input data and salt assimilative capacity forecasts together with increasing stakeholder awareness and involvement in water quality resource management activities in the river basin. Two modeling approaches have been developed simultaneously. The first relies on a statistical analysis of the relationship between flow and salt concentration at three compliance monitoring sites and the use of these regression relationships for forecasting. The second salt load forecasting approach is a customized application of the Watershed Analysis Risk Management Framework (WARMF), a watershed water quality simulation model that has been configured to estimate daily river salt assimilative capacity and to provide decision support for real-time salinity management at the watershed level. Analysis of the results from both model-based forecasting approaches over a period of five years shows that the regression-based forecasting model, run daily Monday to Friday each week, provided marginally better performance. However, the regression-based forecasting model assumes the same general relationship between flow and salinity which breaks down during extreme weather events such as droughts when water allocation cutbacks among stakeholders are not evenly distributed across the basin. A recent test case shows the utility of both models in dealing with an exceedance event at one compliance monitoring site recently introduced in 2020.

Study on Total Control of Total Nitrogen in the Laizhou Bay

Human activity imposes a stronger and increasing impact on the coastal environment by land-based discharge and run-off pollution inputs. Land-based total nitrogen (TN) pollution, as the main cause of eutrophication in the Laizhou Bay, China, should be controlled effectively. Based on a three-dimensional pollution transport model, 20 groups of allocation schemes were designed under the requirement that the allocations of three estuaries in the inner bay were adjusted properly, while the two estuaries in the outer bay, i.e., the Yellow River and the Jiehe River, were kept unchanged. The statistical results show that the area ratio of heavily polluted seawater to the entire Laizhou Bay reached the maximum (35.14%) when the load allocation of the Xiaoqinghe River accounted for a high proportion (65%), and the Yuhe River and the Jiaolaihe River accounted for 15% and 20%, respectively. Overall, the pollution levels of the Laizhou Bay were positively associated with the allocation of the Xiaoqinghe River. Reducing pollutant allocation in the Xiaoqinghe River contributed most to the improvement of the seawater quality of the entire Laizhou Bay, and it was followed by a reduction in the Yuhe River and the Jiaolaihe River.

Bi-level decentralized control of electric heating loads considering wind power accommodation in real-time electricity market

Flexible resources on demand-side, such as electric heating loads (EHLs), are perceived as an effective way of supporting the power balance of power grids with large scale renewable energy integration. However, it is difficult to quickly, effectively and evenly aggregate and schedule a large population of these loads because of their heterogeneity and geographic dispersion. The efficiency and effectiveness of optimal control are important for achieving the power balance between power source and load, especially in real-time scheduling. Moreover, the even load allocation between these heterogeneous loads also needs to motivate users participation in real-time power balance. To follow wind power in the real-time electricity market, this study presents a bi-level control method for EHLs based on distributed optimization computing, which considers the bi-level queuing method, different load control modes and multi-time scales between different control levels. First, each load group, which includes a large population of EHLs is controlled by a distributed server (DS); all the load groups are scheduled by the central management server (CMS), which deals with the wind farm or electricity retailer. Next, a distributed optimization model is built based on the bi-level control structure, in which the different power balance statuses and multi-time scales between the electricity market and EHLs are considered. Furthermore, considering the power balance on the multi-time scales, layer-by-layer load allocation optimization through the bi-level time-varying temperature queuing method, and the load-leveling optimization, serve as the sequential optimization problems. Finally, a simulation including 12,500 EHLs based on measured data in northern China is carried out. The results show that the proposed approach can effectively realize real-time power balance between wind power and EHLs, while maintaining uniform load allocation between the EHLs.

Performance Characterization of Load Balancing Algorithm

The developing interest in mobile services increases the demand for well-planned and cautiously managed wireless local area networks (WLAN) deployment. In WLAN, a station can access services of the network through an access point (AP) after associating with it. Any number of access points can be accessed by the station whose signal strength is available from among the APs. But practically, a WLAN station (STA) always associates with the access point with higher signal strength among the APs. In WLAN, mobile stations continuously change their location, which results in an uneven network load allocation. This uneven load dissemination prompts an extensive performance degradation of WLAN. This paper presents mathematical modeling to characterize the WLAN performance by balancing the network load and enhancing network throughput. Riverbed Modeler simulator was used to investigate the performance parameters as network load and throughput of the network.

Allocation of allowable pollution load by using the bankruptcy solution rules

Abstract Bankruptcy solution methods are widely used and efficient methods for conflict resolution which attract considerable attention in the area of solving conflicts related to water resources. However, most of the related studies have focused on the use of bankruptcy solution methods in solving quantitative water resources conflicts. In this study, four bankruptcy solution rules including proportional (PRO), constrained equal awards (CEA), constrained equal losses (CEL), and Talmud (TAL) rules were used to develop four models to allocate the allowable pollution loads to pollution sources. One of the novel aspects of the current study is to consider the amount of each flow discharge in addition to the pollution concentration of each pollution source. Evaluation of performances of the selected bankruptcy solution rules in a reach of Karun River in Iran showed that the CEA-based model can be considered as the most desirable option for small pollution sources whereas the CEL-based model seems to be the most appropriate option for large pollution sources. The models based on PRO and TAL rules provide results between those of CEA and CEL rules which can be considered as more probable options to reach agreement on between small and large pollution sources.

Load Allocation as Quality and secured in Mobile Cloud Networking Location

In portable cloud organizations (MCNs), a versatile client is associated with a cloud worker through an organization entryway, which is answerable for giving the necessary nature of-administration (QoS) to the clients. On the off chance that a client expands its administration interest, the associating passage may neglect to give the mentioned QoS because of the over-burden interest, while different entryways remain underloaded. Because of the expansion in burden in one Gateway, the sharing of burden among all the passages is one of the imminent answers for giving QoS-ensured administrations to the portable clients. Moreover, if a client makes trouble, the circumstance turns out to be all the more testing. In this paper, we address the issue of QoS-ensured made sure about help provisioning in MCNs. We plan a utility boost issue for quality-guaranteed made sure about burden sharing (QuaLShare) in MCN, and decide its ideal arrangement utilizing sell off hypothesis. In QuaLShare, the over-burden passage identifies the getting out of hand Gateways, and, at that point, keeps them from partaking in the closeout cycle. Hypothetically, we portray both the issue and the arrangement approaches in a MCN climate. At last, we explore the presence of Nash Equilibrium of the proposed plot. We expand the answer for the instance of different clients, trailed by hypothetical examination. Mathematical investigation sets up the accuracy of the proposed calculations.

The examination of stress shielding in a finite element lumbar spine inclusive of the thoracolumbar fascia.

Despite the prevalence of low back pain (LBP) in society, the pathomechanism of LBP continues to elude researchers. LBP patients have demonstrated morphological and material property changes to their lumbar soft tissues, potentially leading to irregular load sharing within the lumbar spine. This study aims to analyze potential stress shielding consequential of augmented soft tissue properties via the comparison of a healthy and LBP finite element models. The models developed in this study include the vertebrae, intervertebral discs and soft tissues from L1-S1. Soft tissue morphology and material properties for the LBP model were augmented to reflect documented clinical findings. Model validation preceded testing and was confirmed through comparison to the available literature. Relative to the healthy model, the LBP model demonstrated an increase in stress by 15.6%, with 99.8% of this stress increase being distributed towards the thoracolumbar fascia. The majority of stress skewed towards the fascia may indicate a potential stress allocation bias whereby the lumbar muscles are unable to receive regular loading, leading to stress shielding. This load allocation bias and subsequent stress shielding may potentially contribute to the progression and pathomechanism of LBP but prospective studies would be required to make that link.

ACADEMIC WORKLOADS: INPUTS TO INSTRUCTIONAL LEADERS’ PRODUCTIVITY AND JOB SATISFACTION

This study was conducted to determine the significant effect of academic workloads to productivity and job satisfaction of elementary teachers in selected schools in Liliw District, Laguna. It is important to value the teachers’ productivity and job satisfaction because the researcher believed that these influences teachers’ turnover and quality of teaching. The independent variables included the academic workloads of elementary teachers. On the other hand, teachers’ productivity and job satisfaction are used as an indicator for dependent variables. It aimed to answer the questions such as the mean level of respondent’s academic workloads in terms of: Teaching Load Allocation, Working Hours, Preparation Time, Coaching and Mentoring and Ancillary Function. Also, the mean level of instructional leaders’ productivity in terms of Community services and linkages, Research, Professional Development and Awards and Recognition as well as the mean level of instructional leaders’ job satisfaction in terms of Work Condition, Job Security, Salaries and Benefits, Working Environment; and Social Satisfaction. Presented the summary of findings, ancillary function had a significant effect to instructional leaders’ productivity as to research and job satisfaction as to Job Security, Salaries and Benefits. Preparation time had a significant effect to teachers’ job satisfaction as to work condition and social satisfaction. Ancillary function and preparation time had significant effect to teachers’ productivity as to community services and linkages and professional development. Therefore, the null hypothesis that academic workloads have no significant effect on instructional leaders’ productivity and job satisfaction among selected elementary schools in Liliw, Laguna at 0.05 level of significance was partially accepted. Based on the drawn conclusions resulted to the following recommendations: Rebalance the workload on a regular basis, it may be recommended that automating faculty workload to ensure faculties in institutions optimally spend their time and align with the interests of the institution to maximize efficiency and effectiveness in all areas of operations. Faculty workload management system can help administrators to determine how best to divide the work. Furthermore, creating an action plan based on evaluation scores to enable faculty members to attend workshops, courses and conferences that promote the development of skills for both teaching and research can also be an option for the Academic Workloads of teachers to be improved.

Accounting for the faculty differentials in the production of PhD graduates in a South African university

The ability of an institution to graduate students, also known as the throughput rate, is one of the most important means of an institution receiving a grant/ subsidy from the government. This article sought to interrogate the differentials in throughput rates of PhD graduates per faculty in a selected institution over a period of five years. Framed within the interpretive paradigm, a qualitative approach and a case study design were adopted. A non-probability purposive sample of 30 participants was selected the academic staff within the six faculties that make up the university under investigation. Data was collected through in-depth interviews and document analysis. Interview transcripts were analysed thematically and using the constant comparison technique. The major findings pointed to differentials in PhD production across faculties as emanating from variations in supervision approaches as reflected in the recruitment and selection of candidates, students’ composition, allocation of supervision load, preparation and orientation of candidates, mentoring of both students and junior staff members, as well as monitoring and evaluation of students’ progress. The findings also revealed challenges like lack of financial support for students, poor structural set-up of some faculties as well as “positive” discrimination in some faculties. These factors constrained the throughput rates in different faculties differently, resulting to a difference in PhD graduate production. It is concluded that there are some quality concerns resulting from the poor processes and procedures as well as the number of graduates from some staff members. It is recommended that the university harmonise its diverse PhD processes and procedures, and enlarge some faculties by creating distinct departments to provide requisite support and interventions to narrow the differentials and improve quality.

Adaptive data-driven optimization of chiller loading with domain knowledge

In order to ensure energy saving and reliable operation for the actual multi-chiller systems, this paper proposes a novel chiller loading strategy that combines the operation data and domain knowledge. The operation data are used to establish the near-optimal performance map which can guide the optimization of chiller loading. The domain knowledge is used to formulate rules to keep the operation reliability of multi-chiller systems. Then a comprehensive method is developed to determine the near-optimal load allocation by considering the map, rules, and the current operation condition. Both the performance prediction study and on-site study are conducted to validate the proposed control strategy. In the performance prediction study, the strategy is compared with other two reference strategies during March to November. The results show that the proposed strategy has the highest energy efficiency among the three strategies. In field study, the proposed strategy is compared with the original strategy on the actual multi-chiller system. The on-site results show that the total energy saving of the proposed strategy is 5.3% compared with that of the original strategy. Then the proposed strategy can adapt to different operation conditions, ensuring energy savings while operating within the plant's constraints.