Equipment Capacity Research Articles

Exploiting user preferences to reduce bandwidth requirements for VoD services with client caching

Internet traffic is already dominated by video streaming applications. The quality of transmitted videos and the number of content available online is expected to increase in the upcoming years, which will further pressure the available network infrastructures. In this scenario, Video-on-Demand services require that distribution mechanisms improve the efficiency of video transmission, which impacts the network performance and system scalability. The efficiency of distribution is strongly related to the operating costs of the providers of such services. The most efficient methods available for Video-on-Demand distribution use strategies that combine multicast transmission and the storage capacity of the user's equipment. This paper presents a new method for Video-on-Demand distribution that explores the client storage capabilities by modelling the users' preferences with a Hidden Markov Model. The efficiency of the proposed method is demonstrated through computational simulations of different scenarios, including a sample of real users' activity. Our results indicate that the proposed scheme substantially outperforms the current Video-on-Demand distribution mechanisms in terms of network bandwidth consumption, significantly reducing operation costs by improving the system scalability.

Aggregate production planning model under demand uncertainty: A case study in an Indonesian cement company

In this paper, a multi-product, multi-stage and multi-period aggregate production-planning model is proposed to deal with demand uncertainty in an Indonesian Cement Company. The demand uncertainty is modelled as a number of discrete scenarios with known probabilities. This problem consists of determining the optimal production, subcontract and inventory level of clinker and cement in order to fulfil demand at minimum cost within the planning horizon. This research aims to develop an aggregate production-planning model under demand uncertainty in an Indonesian Cement Company. The model constructed as a linear programming problem using scenario-based approach to satisfy demand at minimum cost. The outcome of this research is the development of an aggregate production-planning model that accommodates demand uncertainty in Indonesian Cement Company by considering material balance at each stage of the process, equipment capacity and inventory storage capacity during the planning horizon. The proposed model can be used as a decision-making basis for production and inventory control manager to produce or subcontract clinker and semen in each period to fulfil demand at minimum cost.

Optimization of heavy equipment for earthwork in the construction of Mainroad Section X of Pandaan-Malang Toll Road

The construction of Mainroad Section X of Pandaan-Malang Toll Road requires of heavy equipment for excavation and embankment works. The type and number of the heavy equipment can be varied depending upon the construction volume, equipment capacity, and the budget. Therefore, the combination of heavy equipment must be chosen carefully to minimize the cost. This study aims to determine the optimum number of heavy equipment combinations with constraints of work volume, schedule, and resources availability to minimize the construction cost. The data needed is site lay-out plan, cross section of the road, project time schedule, specifications of the heavy equipment, and the resources unit price. The method for optimization is Linear Programming using Simplex Method. The results shows that the optimum combination of heavy equipment for excavation work are 14 units of bulldozer type Zoomlion ZD160-3, 5 unit excavator type Komatsu PC200-8MO, and 19 units dump trucks type Mitsubishi Fuso-FN627 at Rp 14.839.362.044,00. As for the embankment work, the optimum equipment are 5 units excavators type Komatsu PC200-8MO, 19 units of dump truck type Mitsubishi Fuso-FN627, 19 units of motor grader type Caterpillar 120K, 18 units of sheep foot roller type Ammann ASC-200, and 23 units of water tank truck type Mitsubishi-125HD at Rp 22.979.058.760,00.

Site of Care for COVID-19-Like Respiratory Illnesses.

COVID-19 is primarily a respiratory illness. Historically, upper and lower respiratory illness has been cared for at home or in the ambulatory primary care setting. It is likely that patients experiencing COVID-19-like symptoms may first contact their primary care provider. The Medical Expenditure Panel Survey (MEPS) is a representative sample of patients from the United States that regularly assesses their use of medical care services. We analyzed 2017 MEPS data to determine the number and proportion of patients who were seen in primary care or family medicine ambulatory settings or hospitalized for upper or lower respiratory illness or pneumonia. In a given year, 19.5 million patients are seen by primary care for an upper respiratory illness, 10.7 million patients for bronchitis, and 9 million for pneumonia. In contrast, 890,000 patients are hospitalized with pneumonia. Given that a primary etiology for respiratory illness in early 2020 was SARS CoV-2 (COVID-19), primary care practices likely were the site of first contact for most patients with COVID-19 illness. Unfortunately, there has been inadequate support for in-person and telehealth visits. Primary care clinicians reported serious shortages of personal protective equipment (PPE) and testing capacity. Inadequate reimbursement for telehealth visits coupled with decreased in-person visits put primary care practices at risk of layoffs and closure. Policies related to primary care payment, federal relief efforts, PPE access, testing and follow-up capacity, and telehealth technical support are essential so primary care can provide first contact and continuity for their patients and communities throughout the COVID-19 pandemic response and recovery.

Seismic response of electrical equipment subjected to high–frequency ground motions

Recent ground motion studies conducted at nuclear facilities indicate that in Central and Eastern United States, the ground motion response spectra exceed the safe–shutdown earthquake spectra at high frequencies. Even though high–frequency ground motions do not cause structural damage, high–frequency accelerations may propagate through the structure and interfere with the output of the safety–related equipment such as relays required to ensure safe shutdown of the plant during a seismic event. Hence, it is essential to seismically qualify electrical equipment subjected to high–frequency accelerations. The seismic qualification is conducted by comparing in–cabinet response spectra evaluated at the equipment locations with the capacities of equipment obtained from shake table tests. The in–cabinet response spectrum is obtained from analysis of nuclear power plant building and electrical cabinet in which the equipment are mounted. This study is based on the hypothesis that the high–frequency motions do not reach the equipment as the small displacements induced by such motions are filtered out by the geometric nonlinearities. The effect of two different types of nonlinearities are studied: (1) a gap in the connection between electrical cabinet and floor; (2) sliding friction between electrical cabinet’s base and the floor. The results from an analyses of various different cases show that the high–frequency motions do not reach the relays if the maximum displacement of building floor is less than the gap. Even if the displacement is larger than the gap, the in–cabinet spectral accelerations are not excessively high. On the contrary, results from a conventional linear analysis give excessively high unrealistic spectral accelerations.

Qualitative and quantitative detection of SARS-CoV-2 RNA in untreated wastewater in Western Cape Province, South Africa.

Recent studies have shown that the detection of SARS-CoV-2 genetic material in wastewater may provide the basis for a surveillance system to track the environmental dissemination of this virus in communities. An effective wastewater-based epidemiology (WBE) system may prove critical in South Africa (SA), where health systems infrastructure, testing capacity, personal protective equipment and human resource capacity are constrained. In this proof-of-concept study, we investigated the potential of SARS-CoV-2 RNA surveillance in untreated wastewater as the basis for a system to monitor COVID-19 prevalence in the population, an early warning system for increased transmission, and a monitoring system to assess the effectiveness of interventions. The laboratory confirmed the presence (qualitative analysis) and determined the RNA copy number of SARS-CoV-2 viral RNA by reverse transcription polymerase chain reaction (quantitative) analysis from 24-hour composite samples collected on 18 June 2020 from five wastewater treatment plants in Western Cape Province, SA. The study has shown that a WBE system for monitoring the status and trends of COVID-19 mass infection in SA is viable, and its development and implementation may facilitate the rapid identification of hotspots for evidence-informed interventions.

Changing the conventional clarification method in metal sulfide precipitation by a membrane-based filtration process

The metal sulfide precipitation process is a widely studied technology used to recover metals or remove pollutants from different aqueous sources. However, the conventional clarification stage used to separate the generated precipitates cannot effectively remove them from recovered solutions. Taking this into account, the current study focuses on developing a new separation method applied in metal sulfide precipitates, based on a membrane filtration process. Different operating conditions and metal concentration in the feed solution were evaluated for the separation of copper sulfide precipitates formed from synthetic cyanide solutions in ceramic microfiltration membranes. Results showed attractive values of flux and copper recovery. Flux results ranged between 0.9 L/m2s and 1.2 L/m2s for copper concentrations above 500 mg/L, and copper recoveries resulted closer to 100% at the determined optimal operating conditions (4.5 pH, 120% NaHS stoichiometric dosage, and 2 bar feed pressure). These flux values decreased up to one order of magnitude for diluted copper concentrations, due to a change of aggregation capacity of precipitates. This study has demonstrated that the membrane filtration process can be a suitable alternative for the conventional gravitational clarification, promoting better performance results in terms of equipment capacity, metal recovery, and process safety.

Analysis of green technology investment for Chinese waste electrical and electronic equipment processing enterprises under different subsidy modes

Under the current subsidy of China, the dismantle capacity of waste electrical and electronic equipment (WEEE) has expanded dramatically contrary to a weak investment in green technologies for deep processing. Green technology investment plays a critical role in promoting the recycling rate or the purification degree of the recycled materials, thus benefiting to resources recovery and the establishment of an environmental-friendly society. This study firstly modeled the policy impact of the current subsidy mode and varied subsidy values using decision-making models contingent on maximized project net present values (NPV). The results showed that, under bounded capital, the decision time interval and the improved technology degree are positively correlated with the green technology investment, while the technology achievement time and green technology investment cost correlate with it negatively. Meanwhile, it was found that in certain conditions the current subsidy mode and a lifted subsidy value can impede WEEE processing enterprises’ green technology investment. To promote the green technology investment, three reformed subsidy modes with varied threshold settings are proposed. Their impacts on green technology investment are analyzed using decision-making models contingent on NPV and the static game-theoretic model. All of the proposed reformed subsidy modes can promote the green technology investment. Moreover, the associated threshold setting (the third reformed subsidy) performs better in terms of accommodation of fiscal deficits and fairness regarding assignment of subsidy. Lastly, this paper took the treatment of refrigerator and washing machine in China as case studies for a numerical analysis that delivered visible results.

A new forging technology of 19 tons flat ingot with semi-solid liquid core

In order to reduce the casting defects in the large forgings such as solidification segregation, a new forming technology of the semi-solid liquid core forging is put forward in this paper. We elucidate the effectiveness of the semi-solid liquid core forging by simulating the forging process of the 19 tons flat steel ingot in the commercial software DEFORM-3D. A coupled temperature/stress finite element (FE) model is developed to calculate the temperature, the effective stress, the effective strain, the maximum principal stress and the anvil force. These output variables are compared correspondingly from the semi-solid liquid core forging and the traditional forging after the first pass reduction. The deformation of the semi-solid liquid core forging is more uniform and the equipment capacity is also improved. Compared with the traditional forging, the new forging technology is directly forged at high temperature without reheating for a long time and the energy is saved.

Comparative research on nucleocapsid and spike glycoprotein as the rapid immunodetection targets of COVID-19 and establishment of immunoassay strips

The SARS-CoV-2 virus responsible for coronavirus 2019 (COVID-19) poses a significant challenge to healthcare systems worldwide. According to the World Health Organization (WHO), the outbreak of COVID-19 has been a pandemic that infected more than 25.32 million people and caused more than 848.25 thousand deaths worldwide at the time of 1st September 2020. Despite governmental initiatives aimed to contain the spread of the disease, several countries are experiencing unmanageable increases in medical equipment and larger testing capacity. The current diagnosis based on nuclear acid requires specialized instruments, time-consuming, and laborious, the low-cost and convenient technologies were still urgently needed. Both spike and nucleocapsid are key structural proteins of COVID-19 with good immunogenicity, can serve as primary targets for immunoassay. After comparative research, we certified nucleocapsid antigen-monoclonal antibody (mAbs) system was more suitable for the COVID-19 immunodetection. Subsequently, we designed a rapid test strip based on it that can be used in large-scale screening of COVID-19 in population and more suitable for some remote and special needs areas were restricted by a medical condition or for quick and large quantities of screenings.

Selection of Heat Pump Capacity Used at Thermal Power Plants under Electricity Market Operating Conditions

The percentage of heat pumps used in thermal power plants (TPPs) in the fuel and energy balance is extremely low in in most countries. One of the reasons for this is the lack of a systematic approach to selecting and justifying the circuit solutions and equipment capacity. This article aims to develop a new method of calculating the maximum capacity of heat pumps. The method proposed in the article has elements of marginal analysis. It takes into account the limitation of heat pump capacity by break-even operation at electric power market (compensation of fuel expenses, connected with electric power production). In this case, the heat pump’s maximum allowable capacity depends on the electric capacity of TPP, electricity consumption for own needs, specific consumption of conditional fuel for electricity production, a ratio of prices for energy resources, and a conversion factor of heat pump. For TPP based on combined cycle gas turbine (CCGT) CCGT-450 with prices at the Russian energy resources markets at the level of 2019, when operating with the maximum heat load, the allowable heat pump capacity will be about 50 MW, and when operating with the minimum heat load—about 200 MW.

Location planning of distributed energy stations based on improved P-median model

The integrated energy system creates the possibility for the interconnection and coordination of different energy sources, and is an effective means to improve the energy use of the system, increase energy efficiency, and reduce environmental pollution. At present, the planning of distributed energy stations for integrated energy systems mostly focuses on equipment selection and equipment capacity. However, there are relatively few studies on the location of energy stations and pipeline layout planning. Firstly, this paper proposes a distributed energy station location method based on the improved p-median model, which combines the energy supply path of the energy station with the actual transportation network, and introduces the weight coefficient of multi energy load to reflect the diversity of energy demand of load. Finally, the specific solution method is given, and the rationality and feasibility of the proposed method are verified by an example.

Multi-objective operation optimization of regional integrated energy system based on NSGA-II algorithm

With the deepening of China’s energy market reform and the promotion of integrated energy services, the regional integrated energy system becomes an important development direction of energy supply system. In order to maximize the economic efficiency and reduce the air pollutant emission of the regional integrated energy system, the distributed power generation module and the cooling-heat-power (CCHP) triple-supply module are formed into a model, and the power balance, equipment capacity and environmental factors of the system are constrained with the objective function of minimizing the daily operation cost of the system as well as minimizing the air pollutant emission. Based on the mathematical system framework model and the optimal operation control strategy, the NSGA-II algorithm is used to solve the multi-objective programming model to obtain the Pareto solution set, and the hourly output of the optimal operation of the system equipment with both economic and environmental benefits is obtained. The results show that the daily operating costs and pollutant emissions of the district energy system are significantly reduced compared with those without optimization, which effectively solves the problems of low operating efficiency and serious environmental pollution of the district energy system and achieves the optimal operation with both economic and environmental benefits.

Дослідження силових параметрів технологічного процесу різання хлібобулочних виробів

Goal To investigate the influence of force parameters of bakery cutting process on cutting productivity and equipment capacity. Actuality of the work is to optimize energy costs and increase the durability of equipment. Method The technique is that the analysis of the force parameters of the cutting process was performed using experimental studies, on the basis of which a mathematical model of the cutting process was built by the method of a complete factorial experiment. Results. A mathematical model of the technological process of cutting with the help of a full factorial experiment is constructed and the influence of force parameters on cutting productivity and equipment power is analyzed. Scientific novelty. The influence of force parameters on productivity and quality of technological process of cutting of bakery products is confirmed. The mathematical model of the process of cutting bakery products has been improved. Practical significance. The study of the influence of force parameters on the specific cutting force allowed to optimize the process, reducing energy consumption and ensuring maximum productivity of the cutting process. The obtained results can be used to design new equipment.

Controle de sobrecarga de equipamentos de transporte de minérios

Overloading of ore transportation equipment is a problem that directly impacts the physical availability and maintenance costs of the equipment, and must be managed and minimized. In this context, the objective of this study is to improve the overload control of trucks used in the transportation of ore from an underground mine by adopting the 10/10/20 payload control policy and to evaluate the impacts on the physical availability of this equipment. Therefore, the methodology consisted basically in defining the problems caused by the overload of transportation equipment, elaboration and implementation of new operational procedures aiming at the application of the 10/10/20 load control policy, generation of management reports, evaluation of physical availability indicators and problem mitigation. The results indicated an increase in average physical availability of 9.21% from the first to the second half of 2019, the latter contemplating the period in which the overload control actions were implemented. In addition, an increase in the number of trips with load suitable to the equipment's capacity was noted.

Interference Mitigation in HetNets to Improve the QoS Using Q-Learning

Small cells (SCs) based ultra-dense heterogeneous networks (HetNets) are one of the promising solutions for increased coverage and capacity in 5G cellular networks. However, in multi-tiered architecture, co-tier and cross-tier interferences are both performance-limiting factors. Efficient resource allocation techniques can handle interferences effectively, however, their complexity linearly increases with the density of the HetNets resulting from dynamic and unplanned deployment of SCs. Therefore, HetNets can be implemented only through an algorithm that is self-organizing and adaptive to the dynamic conditions. In this research article, a Q-Learning (QL) based adaptive resource allocation scheme is proposed and evaluated for SC-based ultra-dense HetNets. This QL scheme allocates optimal power to the small cell base station (SBS) to meet the minimum required capacity of macrocell user equipment (MUEs) and the small cell user equipment (SUEs) to provide quality of service (QoS). The proposed QL scheme not only maintains the minimum required capacities of the MUEs and SUEs but has also shown a significant improvement in the capacities of MUEs and SUEs in high interference scenarios as compared to the prior works. In the high co-tier and cross-tier interference scenario, where the state of the art schemes fail to maintain the minimum required capacity of the MUE, the proposed scheme provides a minimum MUE capacity of 2 b/s/Hz, which is twice the minimum required QoS threshold. In a similar way, the proposed solution guarantees QoS up to 16 SCs which are 37.5% more SC than the previously reported works in high interference scenario while maintaining a minimum SUE capacity of 1.5 b/s/Hz, which is 33% higher than the minimum required QoS threshold. By simultaneously mitigating co-tier and cross-tier interferences in ultra-dense HetNets, the proposed solution not only improved the minimum capacities of MUEs and SUEs but also sets a new benchmark for minimum QoS threshold.

Variation coefficient of torsional vibrations of the connection nodes of vibrating machines

Purpose. To formalize the dependence of the eigenfrequencies of translational and torsional vibrations of the structural elements of the vibrating machine articulated by the connection node on their design parameters and mechanical characteristics, as well as regulatory requirements for vibration activity, strength and accuracy. To develop a method for selecting the design parameters of the elastic band element of the package, taking into account the specified values of the amplitude and frequency characteristics of the dynamic loads reproduced by the supporting structure and the coefficient of variation of the natural frequencies of translational and torsional vibrations. Methodology. The research is based on fundamental approaches of applied mechanics, machine dynamics and vibration reliability. Findings. The dependences of the eigenfrequencies of torsional vibrations of the body parts of the vibrating machine connected by the connection node on their design parameters and mechanical characteristics are obtained and analyzed. Vibrations around an axis orthogonal to the working direction of the node are considered. A comparative analysis of the natural frequencies of the node in the direction of the transmitted vibration and its circular vibrations from the design parameters and mechanical characteristics of the elastic band elements, their number in the package and the number of packages in the connection node is performed. Originality. It is in the fact that for the first time the dependences describing the natural frequencies of translational and torsional vibrations of the body parts of a vibrating machine, articulated by a package of elastic band elements, are obtained. Also the paradigm for the choice of design parameters and mechanical characteristics of the elastic band element of the package, which is based on the results of a comparative analysis of the eigenfrequencies of vibrations in the working and connected directions through their coefficient of variation is innovative. This made it possible to include the criterion of vibration reproduction accuracy, which is formalized through the coefficient of frequency variation, together with the criteria of strength and rigidity, in the methodology of synthesis of the structural scheme of the vibrating machine. Practical value. The proposed methodological solutions for the calculation and selection of design parameters and mechanical characteristics of tape elastic elements ensure the achievement of vibration activity indicators of articulated parts, as well as the ratio of natural vibration frequencies in the working and related directions at the level of the requirements of normative documents when upgrading existing machines and creating new modern equipment. As a result, the reliability, durability, safety, productivity and load-bearing capacity of machines, equipment and mechanisms of mining engineering, aviation, transport and space technology are increased.

Wireless Resource Management and Resilience Optimization of the M2M‐Oriented Mobile Communication System

Machine‐to‐machine (M2M) communication technology is an emerging technology that can connect smart wireless devices. The most obvious feature of M2M is that the communication between devices does not require human intervention. Therefore, ensuring the low‐energy consumption of M2M devices is a necessary condition for prolonging the survival time of their devices. This paper first considers the coexistence of M2M and H2H scenarios. Aimed at the energy efficiency of M2M equipment and the channel capacity of H2H equipment, a multiobjective problem is constructed for joint spectrum and power resource management, and a weighted Chebyshev algorithm is proposed to solve this problem. Secondly, in view of the additional interference problems caused by the introduction of M2M communication, the intercell cooperative link selection algorithm is used to optimize its resilience. The effectiveness of the algorithm is proven by simulation results.

Research on the model of smart grid wide-area measurement cyber-physical fusion system based on data fusion

Due to price and technical reasons, it is currently impossible to install phasor measurement units in the entire network. How to use the minimum number of phasor measurement units to maximize the observation of the state or dynamic behavior of the power grid is the first consideration for the wide-area measurement system at this stage. This paper proposes a method to optimize the configuration of the phasor measurement unit while ensuring that the power grid is fully observable and can capture the dynamic behavior of the power grid under transient conditions. This paper proposes a load modeling method based on wide-area measurement. Aiming at the problems of traditional large-area power grid load modeling based on load characteristic measurement devices and the characteristics of the current wide-area measurement system, a load modeling method based on local PMU observations is proposed. This method combines particle swarm optimization algorithm and time. Domain simulation calculation can identify the load models at all load nodes of the system at the same time. This paper proposes a CPPS information flow transmission model based on graph theory and information flow dynamics. This model considers the coupling effect of CPPS, the processing capacity of communication equipment and the transmission mode of CPPS information flow, and constructs a CPPS dynamics model from the perspective of communication transmission. In the analysis of the calculation example, by applying the information flow transmission model to CPPS topologies generated by different scales and different modeling methods, the influence of network scale, key nodes and network topology structure on the efficiency of CPPS information transmission was explored, and the effectiveness of the model was verified.

Application of Modern Machinery Design Method in Mine Machinery Design

In the context of the rapid development of science and technology, people’s demand for energy is also increasing. Moreover, mineral resources are an important type of energy indispensable in the development of the national economy. However, as the mining volume of mineral resources continues to increase, the difficulty of mining mineral resources is also increasing. Therefore, we must improve traditional mining machinery and equipment and increase the production capacity of mining machinery and equipment. Only in this way can we improve mining efficiency. In this process, we can use modern mechanical design methods to ensure that the design of mining machinery is compatible with the actual mining of minerals. At the same time, this can also improve the design level of mining machinery and equipment, and ensure mining benefits.