Predicting the course of Covid-19 and other epidemic and endemic disease

The Gompertz Function is an accurate model for epidemics from Cholera in 1853 to Spanish Flu in 1918 and Ebola in 2014. It also describes the acute phase of annual outbreaks of endemic influenza and in all of these instances it has significant predictive power. For Covid-19, we show that the Gompertz Function provides accurate forecasts not just for cases and deaths but, independently, for hospitalisations, intensive care admissions and other medical requirements. In particular Gompertz Function projections of healthcare requirements have been reliable enough to allow planning for: hospital admissions,intensive care admissions,ventilator usage, peak loads and duration. Analysis of data from the Spanish Flu pandemic and the endemic influenza cycle reveals alternating periods of Gompertz Function growth and linear growth in cumulative cases or deaths. Linear growth means the Reproduction Number is equal to 1 which in turn indicates endemicity. The same pattern has been observed with Covid-19. All the initial outbreaks ended in linear growth. Each new outbreak has been preceded by a period of linear growth and has ended with a transition from Gompertz Function growth to linear growth. This suggests that each of these outbreak cycles ended with a transition to endemicity for the current dominant strain and that the normal seasonal respiratory virus periods will continue to see new outbreaks. It remains to be seen if widespread vaccination will disrupt this cyclicality. Because both Gompertz Function Growth and linear growth are accurately predictable, the forecasting problem is reduced to identifying the transition between these modes and to improving the performance in the early Gompertz Function growth phase where its predictive power is lowest. The dynamics of the Gompertz Function are determined by the Gumbel probability distribution. This is an exceptional distribution with respect to the geometry determined by the affine group on the line which is the key to the Gumbel distribution's role as an Extreme Value Theory attractor. We show that this, together with the empirically observed asymmetry in epidemic data, makes the Gompertz Function growth essentially inevitable in epidemic models which agree with observations.

Membership Function Optimization of Fuzzy Inference System Using Cuckoo Search Algorithm for Peak Load Forecasting in National Holiday

This study aims to analysis peak load prediction of Indonesian national holidays for Jawa-Bali electricity system. Forecasting applied using the Fuzzy Logic System (FLS) method combined with the Cuckoo Search Algorithm (CSA). CSA is used to determine the optimal membership function in fuzzy logic. Cuckoo search algorithm has a very good performance in terms of optimization. This method is applied for short-term load estimates on holidays/special days on the Jawa-Bali electricity system, Indonesia. The study used data from daily peak loads during Indonesian national holidays in 2014 on the Jawa-Bali electricity system. The data analyzed is the daily peak load documentation data for 4 days before national holidays and during national holidays in 2014. Testing the simulation results, it was found that the Fuzzy Logic System - Cuckoo Search Algorithm (FLS-CSA) method gives good forecasting results, this is evidenced by using the mean absolute percentage error (MAPE). Forecasting results using the Cuckoo Search Algorithm (CSA) optimization method on fuzzy logic membership functions for peak loads on national holidays on the Java-Bali 500kV electrical system give satisfactory results with an average forecasting error of 1.511314562%.

Clustering-Based Energy Management of Residential Loads by using Artificial Intelligence

Developing countries have witnessed a remarkable surge in the energy crisis due to the supply and demand gap. One of the solutions to overcome this problem is the optimal use of energy that can be achieved by employing demand side management (DSM) and demand response (DR) methods intelligently. Machine learning and data analysis tools help us create intelligent systems that motivate us to use machine learning to implement DSM/DR programs. In this paper, a novel DSM algorithm is introduced to implement DSM intelligently by using artificial intelligence. The results show an efficient implementation of an artificial neural network (ANN) along with demand side management, whereas the peak and off-peak loads were normalized to a certain range where a perfect agreement between supply and demand can be reached.

The role of demand response in residential electricity load reduction using appliance shifting techniques

Purpose Some of the major concerns since the implementation of smart meters (prepaid meters) in some parts of Ghana is how electricity consumers have benefited from data obtained from these meters by providing important statistics on electricity-saving advice; this is one of the key demand-side management methods for achieving load reduction in residential homes. Appliance shifting techniques have proved to be an effective demand response strategy in load reduction. The purpose of this paper is therefore to help consumers of electricity understand when and how they can shift some appliances from peak to off-peak and vice versa. Design/methodology/approach The research uses an analysis technique of Richardson et al. (2010). In their survey on time-of-use surveys to determine the usage of electricity in households as far as appliance shifting was concerned, this study allowed for the assessment of how the occupants’ daily activities in households affect residential electricity consumption. Fell et al. (2014) modeled an aggregate of electricity demand using different appliances (n) in the household. The data for the peak time used in this study were identified from 05:00 to 08:00 and 17:00 to 21:00 for testing the load shifting algorithms, and the off-peak times were pecked from 10:00 to 16:00 and 23:00. This study technique used load management considering real-time scheduling for peak levels in the selected homes. The household devices are modeled in terms of controlled parameters. Using this study’s time-triggered loads on refrigerators and air conditioning systems, the findings suggested that peak loads can be reduced to 45% as a means of maintaining the simultaneous quality of service. To minimize peak loads to around 35% or more, Chaiwongsa and Wongwises (2020) have indicated that room air conditioning and refrigerator loads are simpler to move compared to other household appliances such as cooking appliances. Yet in conclusion, this study made a strong case that a decrease in household peak demand for electricity is primarily contingent on improvements in human behavior. Findings This study has shown that appliance load shifting is a very good way of reducing electrical consumption in residential homes. The comparative performance shows a moderate reduction of 1% in load as was found in the work done by Laicaine (2014). The results, however, indicate that load shifting to a large extent can be achieved by consumer behavioral change. The main response to this study is to advise policymakers in Ghana to develop the appropriate demand response and consumer education towards the general reduction in electrical load in domestic households. The difficulty, however, is how to get the attention of consumer’s on how to start using appliances with less load at peak and also shift some appliances from off-peak times. By increasing consumer knowledge and participation in demand response, it is possible to achieve more efficiency and flexibility in load reduction. The findings were benchmarked with existing comparison studies but may benefit from the potential production of structured references. However, the findings show that load shifting can only be done by modifying consumer actions. Research limitations/implications It should be remembered that this study showed that the use of appliances shifting in residential homes results in load reduction benefits for customers, expressed as savings in electricity prices. The next step will be to build on this cost/benefit study to explain and measure how these reductions transform into net consumer gains for all Ghanaian households. Practical/implications Load shifting will include load controllers in the future, which would automatically handle electricity consumption from various appliances in the home. Based on the device and user needs, the controllers can prioritize loads and appliance usage. The algorithms that underpin automatic load controllers will include knowledge about the behaviors of groups of end users. The results on the time dependency of activities may theoretically inform the algorithms of automatic demand controllers. Originality/value This paper addresses an important need for the country in the midst of finding solutions to an unending energy crisis. This paper presents demand response to the Ghanaian electricity consumer as a means to help in the reduction of load in residential homes. This is a novel research as no one has at yet carried out any research in this direction in Ghana. This paper has some new information to offer in the field of demand in household electricity consumption.

Residual Strength Prediction Based on Size Effect of Cracked Concrete Members

In engineering materials, defects, such as cracks, may occur during production and/or due to various reasons. One of the aims of fracture mechanics is to determine the fracture toughness-based residual strength of structural members with cracks. A quasi-brittle material, such as concrete or rock, may include certain defects, such as voids and cracks, even before being exposed to loads. Experimental analyses on concrete members indicated that specimens’ nominal strength values were decreased as their sizes increased while specimen geometry is the same. In fracture mechanics, this condition was defined as the “size effect” in both concrete and reinforced concrete units. In the literature, numerous theoretical and experimental studies were conducted on beams while compact split-tension specimens, particularly notched ones are limited. In this study, six series of notched beams with three different sizes and notched square prismatic specimens with four different sizes were tested. According to the test results, the peak loads were analyzed by using the fundamental theorem of the modified size effect law. In conclusion, two formulae were proposed to predict the flexural strength and the splitting strength of quasi-brittle bodies with cracks.

RE-EVALUATION OF THE EGYPTIAN CODE OF HOUSING AND ENERGY CONSUMPTION WITH EMPHASIS ON SHADING DEVICES ROTATION ANGLES

The passive system technique is dynamically used as an alternative to the active system, in order to minimize the peak loads and the total EUI in kWh/ m2 for any building prototype. Sun breaker or shading device is a basic traditional method and Mashrabiya previously used for privacy and reduces the heat gained and emitted from sun`s rays, in addition to the fabricated wood material and its specs of bad conductor. the study aims to investigate the effect of rotational shading devices around the y-axis, will the rotation have a significant impact on the EUI or not? The research methodology is built upon generative modeling tool of parametric design, Rhinoceros Version 6.0, with the cooperation of Grasshopper, Ladybug& Honeybee, and Toolbox. Five hundred running simulations are carried out to determine the optimal angle of rotation with maximum reduction in cooling loads, and the interpretation is 30°. Two linear regression equations are derived out of this valuable study to deduce the correlation between independent and dependent variables when the sun breaker material is matt or reflective, and how the total EUI kWh/m2 can be minimized?

Dispatch Strategies for the Utilisation of Battery Storage Systems in Smart Grid Optimised Buildings

This study investigates Smart Grid Optimised Buildings (SGOBs) which can respond to real-time electricity prices by utilising battery storage systems (BSS). Different building design characteristics are assessed to evaluate the impact on energy use, the interaction with the battery, and potential for peak load shifting. Two extreme cases based on minimum and maximum annual energy consumption were selected for further investigation to assess their capability of utilising BSS to perform arbitrage, under real-time pricing. Three operational dispatch strategies were modelled to allow buildings to provide such services. The most energy-efficient building was capable of shifting a higher percentage of its peak loads and export more electricity, when this is allowed. When using the biggest battery (220 kWh) to only meet the building loads, the energy-efficient building was able to shift 39.68% of its original peak loads in comparison to the 33.95% of the least efficient building. With exports allowed, the shifting percentages went down to 31.76% and 29.46%, respectively, while exports of 18.08 and 16.34 kWh/m2 took place. The formation of a regulatory framework is vital in order to establish proper motives for buildings to undertake an active role in the smart grid.

Effects of Shear Tabs and High-Strength Bolts in Seismic Performance of Steel Moment Connections

A shear tab and high-strength bolts are often used to connect a steel H-beam to a column. The design demand and capacity of these elements vary from one standard to the other. To investigate the effect, this study applied a finite element method (FEM) to develop models for two steel moment connections and validated the effectiveness by test data. The connections were characteristic of bolted-web-and-welded-flange details. The FEM models were then used to study the design of shear tabs and high-strength bolts in accordance with the U.S. and Japan standards and compared to the Taiwan practice. The result showed a small difference in the peak loads of the connections. However, the U.S. direct welded flange connection had flange buckling and strength degradation at a relatively smaller drift. The connection had a thinner shear tab and fewer high-strength bolts. The other two connections had very similar design results and loading responses. The increase in shear-tab thickness reduced the stress concentration and fracture potential of the connections. It is, therefore, recommended to design a shear tab with moment capacity greater than the beam web. This will reduce the stress concentration of the base metal surrounding the beam-flange groove welds, increasing the connection ductility.