Search results for: performance modeling

Authors: Ahmed Shaik

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Estimates are very critical in accounting and Financial Reporting cannot be complete without these estimates. There is a long list of accounting estimates that are required to be made to compute Net Income and to determine the value of assets and liabilities. To name a few, valuation of inventory, depreciation, valuation of goodwill, provision for bad debts and estimated warranties, etc. require the use of different valuation models and forecasts. Different business entities under the same industry may use different approaches to measure the value of financial items being reported in Income Statement and Balance Sheet. The disclosure notes do not provide enough details of the approach used by a business entity to arrive at the value of a financial item. Lack of details in the disclosure notes makes it difficult to compare the financial performance of one business entity with the other in the same industry. This paper is an attempt to identify the lack of enough information about accounting estimates in disclosure notes, the impact of the absence of details of accounting estimates on the comparability of financial data and financial analysis. An attempt is made to suggest the detailed disclosure while taking care of the cost and benefit of making such disclosure.

Keywords: accounting estimates, disclosure notes, financial reporting, transparency

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Authors: James S. Kwame, E. Yakushina, P. Blackwell

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The challenges in forming titanium alloys at room temperature are well researched and are linked both to the limitations imposed by the basic crystal structure and their ability to form texture during plastic deformation. One major issue of concern for the sheet forming of titanium alloys is their high sensitivity to surface inhomogeneity. Various machining processes are utilised in preparing sheet hole edges for edge flanging applications. However, the response of edge forming tendencies of titanium to different edge surface finishes is not well investigated. The hole expansion test is used in this project to elucidate the impact of abrasive water jet (AWJ) and electro-discharge machining (EDM) cutting techniques on the edge formability of CP-Ti (Grade 2) and Ti-3Al-2.5V alloys at room temperature. The results show that the quality of the edge surface finish has a major effect on the edge formability of the materials. The work also found that the variations in the edge forming performance are mainly the result of the influence of machining induced edge surface defects.

Keywords: titanium alloys, hole expansion test, edge formability, non-conventional machining

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Authors: Mozadded Hossen

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This study investigates the varied effects of internet addiction on college students, specifically examining the behavioral and academic outcomes. The widespread use of the Internet in academic settings has substantially impacted students' mental well-being and academic achievements. The study investigates the correlation between excessive internet usage and addiction, which manifests through symptoms including social isolation, anxiety, despair, and sleep disruptions. Additionally, the study examines the relationship between internet addiction and academic results, finding that kids with more severe addiction levels generally have lower academic performance, experience diminished focus, and show reduced involvement in academic tasks. The study intends to analyze the many consequences of internet addiction to gain insights into its ramifications. It also urges educational institutions to develop techniques that can reduce the negative impact of internet addiction and encourage healthier internet use among students. The results emphasize the necessity of implementing comprehensive measures to tackle the behavioral and academic difficulties caused by internet addiction among college students.

Keywords: internet addiction, behavioral consequences, college students, social isolation

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Authors: Paolo Grasso, Sai Kalyan Yelike, Federico Benzi, Mathieu Le Cam

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The cabin air quality (CAQ) in commercial aircraft is of prime interest, especially in the context of the COVID-19 pandemic. Current Environmental Control Systems (ECS) rely on a prescribed fresh airflow per passenger to dilute contaminants. An adaptive ECS strategy is proposed, leveraging air sensing and filtration technologies to ensure a better CAQ. This paper investigates the CAQ level achieved in commercial aircraft’s cabin during various flight scenarios. The modeling and simulation analysis is performed in a Modelica-based environment describing the dynamic behavior of the system. The model includes the following three main systems: cabin, recirculation loop and air-conditioning pack. The cabin model evaluates the thermo-hygrometric conditions and the air quality in the cabin depending on the number of passengers and crew members, the outdoor conditions and the conditions of the air supplied to the cabin. The recirculation loop includes models of the recirculation fan, ordinary and novel filtration technology, mixing chamber and outflow valve. The air-conditioning pack includes models of heat exchangers and turbomachinery needed to condition the hot pressurized air bled from the engine, as well as selected contaminants originated from the outside or bled from the engine. Different ventilation control strategies are modeled and simulated. Currently, a limited understanding of contaminant concentrations in the cabin and the lack of standardized and systematic methods to collect and record data constitute a challenge in establishing a causal relationship between CAQ and passengers' comfort. As a result, contaminants are neither measured nor filtered during flight, and the current sub-optimal way to avoid their accumulation is their dilution with the fresh air flow. However, the use of a prescribed amount of fresh air comes with a cost, making the ECS the most energy-demanding non-propulsive system within an aircraft. In such a context, this study shows that an ECS based on a reduced and adaptive fresh air flow, and relying on air sensing and filtration technologies, provides promising results in terms of CAQ control. The comparative simulation results demonstrate that the proposed adaptive ECS brings substantial improvements to the CAQ in terms of both controlling the asymptotic values of the concentration of the contaminant and in mitigating hazardous scenarios, such as fume events. Original architectures allowing for adaptive control of the inlet air flow rate based on monitored CAQ will change the requirements for filtration systems and redefine the ECS operation.

Keywords: cabin air quality, commercial aircraft, environmental control system, ventilation

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Authors: A. Hamidi, S. Khelladi, L. Illoul, A. Tcharkhtchi

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Reactive rotational molding (RRM) is a process to manufacture hollow plastic parts with reactive material has several advantages compared to conventional roto molding of thermoplastic powders: process cycle time is shorter; raw material is less expensive because polymerization occurs during processing and high-performance polymers may be used such as thermosets, thermoplastics or blends. However, several phenomena occur during this process which makes the optimization of the process quite complex. In this study, we have used a mixture of isocyanate and polyol as a reactive system. The chemical transformation of this system to polyurethane has been studied by thermal analysis and rheology tests. Thanks to these results of the curing process and rheological measurements, the kinetic and rheokinetik of polyurethane was identified. Smoothed Particle Hydrodynamics, a Lagrangian meshless method, was chosen to simulate reactive fluid flow in 2 and 3D configurations of the polyurethane during the process taking into account the chemical, and chemiorehological results obtained experimentally in this study.

Keywords: reactive rotational molding, simulation, smoothed particle hydrodynamics, surface tension, rheology, free surface flows, viscoelastic, interpolation

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Authors: Navid Khayat

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This study investigates the retrofitting of schools in Ahvaz City. Three schools, namely, Enghelab, Sherafat, and Golchehreh, in Ahvaz City are initially examined through Schmidt hammer and ultrasonic tests. Given the tests and controls on the structures of these schools, the methods are presented for their reconstruction. The plan is presented for each school by estimating the cost and generally the feasibility and estimated the duration of project reconstruction. After reconstruction, the mentioned tests are re-performed for rebuilt parts and the results indicate a significant improvement in performance of structure because of reconstruction. According to the results, despite the fact that the use of fiber reinforced polymers (FRP) for structure retrofitting is costly, due to the low executive costs and also other benefits of FRP, it is generally considered as one of the most effective ways of retrofitting. Building the concrete coating on walls is another effective method in retrofitting the buildings. According to this method, a grid of horizontal and vertical bars is installed on the wall and then the concrete is poured on it. The use of concrete coating on the concrete and brick structures leads to the useful results and the experience indicates that the poured concrete filled the joints well and provides the appropriate binding and adhesion.

Keywords: renovation, retrofitting, masonry structures, old school

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Authors: Josue Javier Martinez Flores, Jaime Alvarez Quintana

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A thermal rectifier consists of a device which can load a different heat flow which depends on the direction of that flow. That device is a thermal diode. It is well known that heat transfer in solids basically depends on the electrical, magnetic and crystalline nature of materials via electrons, magnons and phonons as thermal energy carriers respectively. In the present research, we have synthesized polycrystalline Ni-Cu alloys and identified the Curie temperatures; and we have observed that by way of secondary phase transitions, it is possible manipulate the heat conduction in solid state thermal diodes via transition temperature. In this sense, we have succeeded in developing solid state thermal diodes with a control gate through the Curie temperature via the activation and deactivation of magnons in Ni-Cu ferromagnetic alloys at room temperature. Results show thermal diodes with thermal rectification factors up to 1.5. Besides, the performance of the electrical rectifiers can be controlled by way of alloy Cu content; hence, lower Cu content alloys present enhanced thermal rectifications factors than higher ones.

Keywords: thermal rectification, Curie temperature, ferromagnetic alloys, magnons

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Authors: Johana Jaramillo, Robin Kalfat, Dmitriy A. Dikin

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The cement production process is one of the major sources of carbon dioxide (CO₂), a potent greenhouse gas. Indeed, as a result of its cement manufacturing process, concrete contributes approximately 8% of global greenhouse gas emissions. In addition to environmental concerns, concrete also has a low tensile and ductility strength, which can lead to cracks. Graphene nanoplatelets (GNPs) have proven to be an eco-friendly solution for improving the mechanical and durability properties of concrete. The current research investigates the effects of preparing concrete enhanced with GNPs by using different wet dispersions techniques and mixing methods on its mechanical properties. Concrete specimens were prepared with 0.00 wt%, 0.10 wt%, 0.20 wt%, 0.30 wt% and wt% GNPs. Compressive and flexural strength of concrete at age 7 days were determined. The results showed that the maximum improvement in mechanical properties was observed when GNPs content was 0.20 wt%. The compressive and flexural were improved by up to 17.5% and 8.6%, respectively. When GNP dispersions were prepared by the combination of a drill and an ultrasonic probe, mechanical properties experienced maximum improvement.

Keywords: concrete, dispersion techniques, graphene nanoplatelets, mechanical properties, mixing methods

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Authors: Wheyming Tina Song, Chi-Hao Hong

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In this study, we investigate the effect of a new boarding policy - short stay, on the overcrowding efficiency in emergency department (ED). The decision variables are no. of short stay beds for least acuity ED patients. The performance measurements used are national emergency department overcrowding score (NEDOCS) and ED retention rate (the percentage that patients stay in ED over than 48 hours in one month). Discrete event simulation (DES) is used as an analysis tool to evaluate the strategy. Also, common random number (CRN) technique is applied to enhance the simulation precision. The DES model was based on a census of 6 months' patients who were treated in the ED of the National Taiwan University Hospital Yunlin Branch. Our results show that the new short-stay boarding significantly impacts both the NEDOCS and ED retention rate when the no. of short stay beds is more than three.

Keywords: emergency department (ED), common random number (CRN), national emergency department overcrowding score (NEDOCS), discrete event simulation (DES)

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Authors: Débora C. G. Oliveira, Julio D. Salles, Bruna A. Moriy, João A. Rossignolo, Holmer Savastano Jr.

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The objective of this study was to identify the optimal level of partial replacement of Portland cement by the ashes originating from burning straw and bagasse from sugar cane (ASB). Order to this end, were made five series of flat plates and cylindrical bodies: control and others with the partial replacement in 20, 30, 40, and 50% of ASB in relation to the mass of the Ordinary Portland cement, and conducted a mechanical testing of simple axial compression (cylindrical bodies) and the four-point bending (flat plates) and determined water absorption (WA), bulk density (BD) and apparent void volume (AVV) on both types of specimens. Based on the data obtained, it may be noted that the control treatment containing only Portland cement, obtained the best results. However, the cylindrical bodies with 20% ashes showed better results compared to the other treatments. And in the formulations plates, the treatment which showed the best results was 30% cement replacement by ashes.

Keywords: modulus of rupture, simple axial compression, waste, bagasse sugarcane

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Authors: Kriengkrai Assawamartbunlue, Channarong Wantha

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This paper presents the effects of the mean operating pressure on the optimal operating frequency based on temperature differences across stack ends in a thermoacoustic refrigerator. In addition to the length of the resonance tube, components of the thermoacoustic refrigerator have an influence on the operating frequency due to their acoustic properties, i.e. absorptivity, reflectivity and transmissivity. The interference of waves incurs and distorts the original frequency generated by the driver so that the optimal operating frequency differs from the designs. These acoustic properties are not parameters in the designs and it is very complicated to infer their responses. A prototype thermoacoustic refrigerator is constructed and used to investigate its optimal operating frequency compared to the design at various operating pressures. Helium and air are used as working fluids during the experiments. The results indicate that the optimal operating frequency of the prototype thermoacoustic refrigerator using helium is at 6 bar and 490Hz or approximately 20% away from the design frequency. The optimal operating frequency at other mean pressures differs from the design in an unpredictable manner, however, the optimal operating frequency and pressure can be identified by testing.

Keywords: acoustic properties, Carnot’s efficiency, interference of waves, operating pressure, optimal operating frequency, stack performance, standing wave, thermoacoustic refrigerator

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Authors: Mark Lokanan

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The paper analyzes the processing of complaints against investment brokers and dealer members through the Investment Industry Regulatory Organization of Canada (IIROC) from 2008 to 2017. IIROC is the self-regulatory organization (SRO) that is responsible for policing investment dealers and brokerage firms that trade in Canada’s securities market. Data from the study came from IIROC's enforcement annual reports for the years examined. The case processing is evaluated base on the misconduct funnel that was originally designed for street crime and applies to the enforcement of investment fraud. The misconduct funnel is used as a framework to examine IIROC’s claim that it brought in more complaints (funnel in) than government regulators and shows how these complaints are funneled out and funneled away as they are processed through IIROC’s enforcement system. The results indicate that IIROC is ineffective in disciplining its members and is unable to handle the more serious quasi-criminal and improper sales practices offenses. It is hard not to see the results of the paper being used by the legislator in Ottawa to show the importance of a federal securities regulatory agency such as the Securities and Exchange Commission (SEC) in the United States.

Keywords: investment fraud, securities regulation, compliance, enforcement

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Authors: Suppara Charoenpoom

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The objectives of this research was to design and develop a quality management of the school buildings and environment. A quantitative and qualitative mixed research methodology was used. The population sample included 14 directors of primary schools. Two research tools were used. The first research tool included an in-depth interview and questionnaire. The second research tool included the Quality Business Process and Quality Work Procedure, and a Key Performance Indicator of each activity. The statistics included mean and standard deviation. The findings for the development of a quality management process of buildings and environment administration of the basic schools consisted of one quality business process (QBP) and seven quality work processes (QWP). The result from the experts’ evaluation revealed that the process and implementation of quality management of the school buildings and environment has passed the inspection process with consensus. This implies that the process of quality management of the school buildings and environment is suitable for implementation. Moreover, the level of agreement in the feasibility of the implementation of this plan had the mean in the range of 0.64-1.00 which suggests the design of the new plan is acceptable.

Keywords: process, building, environment, management

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Authors: Karim Farahmandfar, Hamidolah Izadi, Mohammadreza Rezaei, Amin Ardali, Ebrahim Goshtasbi Rad, Khosro Jafarpoor

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Statistics illustrates that the higher amount of annual energy consumption is related to surmounting the demand in buildings. Therefore, it is vital to economize the energy consumption and also find the solution with regard to this issue. One of the systems for the sake of heating the building is floor heating. As a matter of fact, floor heating performance is based on convection and radiation. Actually, in addition to creating a favorable heating condition, this method leads to energy saving. It is the goal of this article to outline the constructal theory and introduce the optimization method in branch networks for floor heating. There are several steps in order to gain this purpose. First of all, the pressure drop through the two points of the network is calculated. This pressure drop is as a function of pipes diameter and other parameters. After that, the amount of heat transfer is determined. Consequently, as a result of the combination of these two functions, the final function will be determined. It is necessary to mention that flow is laminar.

Keywords: constructal theory, optimization, floor heating system, turbulent flow

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Authors: Pascal François Faye, Baye Mor Sall, Bineta Dembele, Jeanne Ana Awa Faye

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In agriculture, estimating crop yields is key to improving productivity and decision-making processes such as financial market forecasting and addressing food security issues. The main objective of this paper is to have tools to predict and improve the accuracy of crop yield forecasts using machine learning (ML) algorithms such as CART , KNN and SVM . We developed a mobile app and a web app that uses these algorithms for practical use by farmers. The tests show that our system (collection and deployment architecture, web application and mobile application) is operational and validates empirical knowledge on agro-climatic parameters in addition to proactive decision-making support. The experimental results obtained on the agricultural data, the performance of the ML algorithms are compared using cross-validation in order to identify the most effective ones following the agricultural data. The proposed applications demonstrate that the proposed approach is effective in predicting crop yields and provides timely and accurate responses to farmers for decision support.

Keywords: prediction, machine learning, artificial intelligence, digital agriculture

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Authors: Anjana Rajput, Sandeep Chouksey, Bhaskar Bhandari, Shimpi Chourasia

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Ecologically, grassland is any plant community dominated by grasses, whether they exist naturally or because of management practices. Most forest grasslands are anthropogenic and established plant communities planted for forage production, though some are established for soil and water conservation and wildlife habitat. In Satpura Tiger Reserve, Madhya Pradesh, India, most of the grasslands have been established on evacuated village sites. Total of 42 villages evacuated, and study was carried out in 23 sites to evaluate habitat improvement. Grasslands were classified into three categories, i.e., evacuated sites, established sites, and controlled sites. During the present study impact of various management interventions on grassland health was assessed. Grasslands assessment was done for its composition, status of palatable and non-palatable grasses, the status of herbs and legumes, status of weeds species, and carrying capacity of particular grassland. Presence of wild herbivore species in the grasslands with their abundance, availability of water resources was also assessed. Grassland productivity is dependent mainly on the biotic and abiotic components of the area, but management interventions may also play an important role in grassland composition and productivity. Variation in the status of palatable and non-palatable grasses, legumes, and weeds was recorded and found effected by management intervention practices. Overall in all the studied grasslands, the most dominant grasses recorded are Themeda quadrivalvis, Dichanthium annulatum, Ischaemum indicum, Oplismenus burmanii, Setaria pumilla, Cynodon dactylon, Heteropogon contortus, and Eragrostis tenella. Presence of wild herbivores, i.e., Chital, Sambar, Bison, Bluebull, Chinkara, Barking deer in the grassland area has been recorded through the installation of camera traps and estimated their abundance. Assessment of developed grasslands was done in terms of habitat suitability for Chital (Axis axis) and Sambar (Rusa unicolor). The parameters considered for suitability modeling are biotic and abiotic life requisite components existing in the area, i.e., density of grasses, density of legumes, availability of water, site elevation, site distance from human habitation. Findings of the present study would be useful for further grassland management and animal translocation programmes.

Keywords: carrying capacity, dominant grasses, grassland, habitat suitability, management intervention, wild herbivore

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Authors: Alexander Hudson, Shaogang Gong

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Structure determination is key to understanding protein function at a molecular level. Whilst significant advances have been made in predicting structure and function from amino acid sequence, researchers must still rely on expensive, time-consuming analytical methods to visualise detailed protein conformation. In this study, we demonstrate that it is possible to make accurate (≥80%) predictions of protein class and architecture from structures determined at low (>3A) resolution, using a deep convolutional neural network trained on high-resolution (≤3A) structures represented as 2D matrices. Thus, we provide proof of concept for high-speed, low-cost protein structure classification at low resolution, and a basis for extension to prediction of function. We investigate the impact of the input representation on classification performance, showing that side-chain information may not be necessary for fine-grained structure predictions. Finally, we confirm that high resolution, low-resolution and NMR-determined structures inhabit a common feature space, and thus provide a theoretical foundation for boosting with single-image super-resolution.

Keywords: transfer learning, protein distance maps, protein structure classification, neural networks

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Authors: Lalit Ahuja, Nancy Das, Yashas Shetty

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LED lighting has been increasingly adopted for vehicles in both domestic and foreign automotive markets. Although this miniaturized technology gives the best light output, low energy consumption, and cost-efficient solutions for driving, the same is the need of the hour. In this paper, we present a methodology for driving the highest class two-wheeler headlamp with regulator and rectifier (RR) output. Unlike usual LED headlamps, which are driven by a battery, regulator, and rectifier (RR) driven, a low-cost and highly efficient LED Driver Module (LDM) is proposed. The positive half of magneto output is regulated and used to charge batteries used for various peripherals. While conventionally, the negative half was used for operating bulb-based exterior lamps. But with advancements in LED-based headlamps, which are driven by a battery, this negative half pulse remained unused in most of the vehicles. Our system uses negative half-wave rectified DC output from RR to provide constant light output at all RPMs of the vehicle. With the negative rectified DC output of RR, we have the advantage of pulsating DC input which periodically goes to zero, thus helping us to generate a constant DC output equivalent to the required LED load, and with a change in RPM, additional active thermal bypass circuit help us to maintain the efficiency and thermal rise. The methodology uses the negative half wave output of the RR along with a linear constant current driver with significantly higher efficiency. Although RR output has varied frequency and duty cycles at different engine RPMs, the driver is designed such that it provides constant current to LEDs with minimal ripple. In LED Headlamps, a DC-DC switching regulator is usually used, which is usually bulky. But with linear regulators, we’re eliminating bulky components and improving the form factor. Hence, this is both cost-efficient and compact. Presently, output ripple-free amplitude drivers with fewer components and less complexity are limited to lower-power LED Lamps. The focus of current high-efficiency research is often on high LED power applications. This paper presents a method of driving LED load at both High Beam and Low Beam using the negative half wave rectified pulsating DC from RR with minimum components, maintaining high efficiency within the thermal limitations. Linear regulators are significantly inefficient, with efficiencies typically about 40% and reaching as low as 14%. This leads to poor thermal performance. Although they don’t require complex and bulky circuitry, powering high-power devices is difficult to realise with the same. But with the input being negative half wave rectified pulsating DC, this efficiency can be improved as this helps us to generate constant DC output equivalent to LED load minimising the voltage drop on the linear regulator. Hence, losses are significantly reduced, and efficiency as high as 75% is achieved. With a change in RPM, DC voltage increases, which can be managed by active thermal bypass circuitry, thus resulting in better thermal performance. Hence, the use of bulky and expensive heat sinks can be avoided. Hence, the methodology to utilize the unused negative pulsating DC output of RR to optimize the utilization of RR output power and provide a cost-efficient solution as compared to costly DC-DC drivers.

Keywords: class D LED headlamp, regulator and rectifier, pulsating DC, low cost and highly efficient, LED driver module

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Authors: Eun-Jeong Jang

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Inequality has been considered as a core issue in public policy. Korea is categorized into one of the countries in the high level of inequality, which matters to not only current but also future generations. The relationship between individuals' origin and destination has an implication of intergenerational inequality. The previous work on this was mostly conducted at macro level using panel data to our knowledge. However, in this level, there is no room to track down what happened during the time between origin and destination. Individuals' origin is represented by their parents' socio-economic status, and in the same way, destination is translated into their own socio-economic status. The first research question is that how origin is related to the destination. Certainly, destination is highly affected by origin. In this view, people's destination is already set to be more or less than a reproduction of previous generations. However, educational achievement is widely believed as an independent factor from the origin. From this point of view, there is a possibility to change the path given by parents by educational attainment. Hence, the second research question would be that how education is related to destination and also, which factor is more influential to destination between origin and education. Also, the focus lies in the mediation of education between origin and destination, which would be the third research question. Socio-economic status in this study is referring to class as a sociological term, as well as wealth including labor and capital income, as an economic term. The combination of class and wealth would be expected to give more accurate picture about the hierarchy in a society. In some cases of non-manual and professional occupations, even though they are categorized into relatively high class, their income is much lower than those who in the same class. Moreover, it is one way to overcome the limitation of the retrospective view during survey. Education is measured as an absolute term, the years of schooling, and also as a relative term, the rank of school. Moreover, all respondents were asked the effort scaled by time intensity, self-motivation, before and during the course of their college based on a standard questionnaire academic achieved model provides. This research is based on a survey at an individual level. The target for sampling is an individual who has a job, regardless of gender, including income-earners and self-employed people and aged between thirties and forties because this age group is considered to reach the stage of job stability. In most cases, the researcher met respondents person to person visiting their work place or home and had a chance to interview some of them. One hundred forty individual data collected from May to August in 2017. It will be analyzed by multiple regression (Q1, Q2) and structural equation modeling (Q3).

Keywords: class, destination, educational achievement, effort, income, origin, socio-economic status, South Korea

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Authors: Shin Je Lee, Go Bong Choi, Jeong Cheol Seo, Jong Min Lee, Gibaek Lee

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Water pipe network is installed underground and once equipped; it is difficult to recognize the state of pipes when the leak or burst happens. Accordingly, post management is often delayed after the fault occurs. Therefore, the systematic fault management system of water pipe network is required to prevent the accident and minimize the loss. In this work, we develop online fault detection system of water pipe network using data of pipes such as flow rate or pressure. The transient model describing water flow in pipelines is presented and simulated using Matlab. The fault situations such as the leak or burst can be also simulated and flow rate or pressure data when the fault happens are collected. Faults are detected using statistical methods of fast Fourier transform and discrete wavelet transform, and they are compared to find which method shows the better fault detection performance.

Keywords: fault detection, water pipeline model, fast Fourier transform, discrete wavelet transform

Procedia PDF Downloads 510

Authors: Taboka Motlhabane, Pradeep Sahoo

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The global demand for cooling has grown exponentially over the past century to meet economic development and social needs, accounting for approximately 10% of the global electricity consumption. As global temperatures continue to rise, the demand for cooling and heating, ventilation and air-conditioning (HVAC) equipment is set to rise with it. The increased use of HVAC equipment has significantly contributed to the growth of greenhouse gas (GHG) emissions which aid the climate crisis- one of the biggest challenges faced by the current generation. The need to address emissions caused directly by HVAC equipment and electricity generated to meet the cooling or heating demand is ever more pressing. Currently, developed countries account for the largest cooling and heating demand, however developing countries are anticipated to experience a huge increase in population growth in 10 years, resulting in a shift in energy demand. Developing countries, which are projected to account for nearly 60% of the world's GDP by 2030, are rapidly building infrastructure and economies to meet their growing needs and meet these projections. Cooling, a very energy-intensive process that can account for 20 % to 75% of a building's energy, depending on the building's use. Solar photovoltaic (PV) driven air-conditioning offers a great cost-effective alternative for adoption in both residential and non-residential buildings to offset grid electricity, particularly in countries with high irradiation, such as Botswana. This research paper explores the potential of a grid-connected solar photovoltaic vapor-compression air-conditioning system for the Peter-Smith herbarium at the Okavango Research Institute (ORI) University of Botswana campus in Maun, Botswana. The herbarium plays a critical role in the collection and preservation of botanical data, dating back over 100 years, with pristine collection from the Okavango Delta, a UNESCO world heritage site and serves as a reference and research site. Due to the herbarium’s specific needs, it operates throughout the day and year in an attempt to maintain a constant herbarium temperature of 16°?. The herbarium model studied simulates a variable-air-volume HVAC system with a system rating of 30 kW. Simulation results show that the HVAC system accounts for 68.9% of the building's total electricity at 296 509.60 kWh annually. To offset the grid electricity, a 175.1 kWp nominal power rated PV system requiring 416 modules to match the required power, covering an area of 928 m2 is used to meet the HVAC system annual needs. An economic assessment using PVsyst found that for an installation priced with average solar PV prices in Botswana totalled to be 787 090.00 BWP, with annual operating costs of 30 500 BWP/year. With self-project financing, the project is estimated to have recouped its initial investment within 6.7 years. At an estimated project lifetime of 20 years, the Net Present Value is projected at 1 565 687.00 BWP with a ROI of 198.9%, with 74 070.67 tons of CO2 saved at the end of the project lifetime. This study investigates the performance of the HVAC system to meet the indoor air comfort requirements, the annual PV system performance, and the building model has been simulated using DesignBuilder Software.

Keywords: vapor compression refrigeration, solar cooling, renewable energy, herbarium

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Authors: Rawad Asfour, Salam Khamas, Edward A. Ball

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This paper is focused on the design of an mm-wave phased array. To date, linear polarization is adapted in the reported designs of phased arrays. However, linear polarization faces several well-known challenges. As such, an advanced design for phased array antennas is required that offers circularly polarized (CP) radiation. A feasible solution for achieving CP phased array antennas is proposed using open-circular loop antennas. To this end, a 3-element circular loop phased array antenna is designed to operate at 28GHz. In addition, the array ability to control the direction of the main lobe is investigated. The results show that the highest achievable field of view (FOV) is 100°, i.e., 50° to the left and 50° to the right-hand side directions. The results are achieved with a CP bandwidth of 15%. Furthermore, the results demonstrate that a high broadside gain of circa 11 dBi can be achieved for the steered beam. Besides, a radiation efficiency of 97 % can also be achieved based on the proposed design.

Keywords: loop antenna, phased array, beam steering, wide bandwidth, circular polarization, CST

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Authors: B. Kriheli, E. Levner, T. C. E. Cheng, C. T. Ng

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During the last decades, research interest in planning, scheduling, and control of emergency response operations, especially people rescue and evacuation from the dangerous zone of marine accidents, has increased dramatically. Until the survivors (called ‘targets’) are found and saved, it may cause loss or damage whose extent depends on the location of the targets and the search duration. The problem is to efficiently search for and detect/rescue the targets as soon as possible with the help of intelligent mobile robots so as to maximize the number of saved people and/or minimize the search cost under restrictions on the amount of saved people within the allowable response time. We consider a special situation when the autonomous mobile robots (AMR), e.g., unmanned aerial vehicles and remote-controlled robo-ships have no operator on board as they are guided and completely controlled by on-board sensors and computer programs. We construct a mathematical model for the search process in an uncertain environment and provide a new fast algorithm for scheduling the activities of the autonomous robots during the search-and rescue missions after an accident at sea. We presume that in the unknown environments, the AMR’s search-and-rescue activity is subject to two types of error: (i) a 'false-negative' detection error where a target object is not discovered (‘overlooked') by the AMR’s sensors in spite that the AMR is in a close neighborhood of the latter and (ii) a 'false-positive' detection error, also known as ‘a false alarm’, in which a clean place or area is wrongly classified by the AMR’s sensors as a correct target. As the general resource-constrained discrete search problem is NP-hard, we restrict our study to finding local-optimal strategies. A specificity of the considered operational research problem in comparison with the traditional Kadane-De Groot-Stone search models is that in our model the probability of the successful search outcome depends not only on cost/time/probability parameters assigned to each individual location but, as well, on parameters characterizing the entire history of (unsuccessful) search before selecting any next location. We provide a fast approximation algorithm for finding the AMR route adopting a greedy search strategy in which, in each step, the on-board computer computes a current search effectiveness value for each location in the zone and sequentially searches for a location with the highest search effectiveness value. Extensive experiments with random and real-life data provide strong evidence in favor of the suggested operations research model and corresponding algorithm.

Keywords: disaster management, intelligent robots, scheduling algorithm, search-and-rescue at sea

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Authors: Hassan Mohammad Karimi, Ali Salehzade Nobari, Hosein Shahverdi

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With the advancement of technology and the decreasing weight of aerial structures, there is a growing demand for alternative energy sources. Structural vibrations can now be utilized to power low-power sensors for monitoring structural health and charging small batteries in drones. Research on extracting energy from flutter using piezoelectric has been extensive in recent years. This article specifically examines the use of a single-jointed beam with a free surface attached to its free end and a bimorph piezoelectric patch connected to the joint, providing two degrees of torsional and bending freedom. The study investigates the voltage harvested at various wind speeds and bending and twisting stiffness in a wind tunnel. The results indicate that as flutter speed increases, the output voltage also increases to some extent. However, at high wind speeds, the limited cycle created becomes unstable, negatively impacting the harvester's performance. These findings align with other research published in reputable scientific journals.

Keywords: energy harvesting, piezoelectric, flutter, wind tunnel

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Authors: Luke Andrighetto, Paul G. Stevenson, Luke C. Henderson, Jim Pearson, Xavier A. Conlan

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As pseudoephedrine, a common ingredient in cold and flu medications is closely monitored and restricted in Australia, alternative methods of accessing it are of interest. The impurities and by-products of every reaction step of pseudoephedrine/ephedrine and methamphetamine synthesis have been mapped in order to develop a chemical fingerprint based on synthetic route. Likewise, seized methamphetamine contains a combination of different cutting agents and starting materials. Therefore, in-silico optimised two-dimensional HPLC with DryLab® and OpenMS® software has been used to efficiently separate complex seizure samples. An excellent match between simulated and real separations was observed. Targeted separation of model compounds was completed with significantly reduced method development time. This study produced a two-dimensional separation regime that offers unprecedented separation power (separation space) while maintaining a rapid analysis time that is faster than those previously reported for gas chromatography, single dimension high performance liquid chromatography or capillary electrophoresis.

Keywords: chemical fingerprint, ephedrine, methamphetamine, two-dimensional HPLC

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Authors: Piotr Romaniuk, Krzysztof Kaczmarek, Adam Szromek

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Background: A number of approaches to assess the performance of health system have been proposed so far. Nonetheless, they lack a consensus regarding the key components of assessment procedure and criteria of evaluation. The WHO and OECD have developed methods of assessing health system to counteract the underlying issues, but they are not free of controversies and did not manage to produce a commonly accepted consensus. The aim of the study: On the basis of WHO and OECD approaches we decided to develop own methodology to assess the performance of health systems in Central and Eastern European countries. We have applied the method to compare the effects of health systems reforms in 20 countries of the region, in order to evaluate the dynamic of changes in terms of health system outcomes.Methods: Data was collected from a 25-year time period after the fall of communism, subsetted into different post-reform stages. Datasets collected from individual countries underwent one-, two- or multi-dimensional statistical analyses, and the Synthetic Measure of health system Outcomes (SMO) was calculated, on the basis of the method of zeroed unitarization. A map of dynamics of changes over time across the region was constructed. Results: When making a comparative analysis of the tested group in terms of the average SMO value throughout the analyzed period, we noticed some differences, although the gaps between individual countries were small. The countries with the highest SMO were the Czech Republic, Estonia, Poland, Hungary and Slovenia, while the lowest was in Ukraine, Russia, Moldova, Georgia, Albania, and Armenia. Countries differ in terms of the range of SMO value changes throughout the analyzed period. The dynamics of change is high in the case of Estonia and Latvia, moderate in the case of Poland, Hungary, Czech Republic, Croatia, Russia and Moldova, and small when it comes to Belarus, Ukraine, Macedonia, Lithuania, and Georgia. This information reveals fluctuation dynamics of the measured value in time, yet it does not necessarily mean that in such a dynamic range an improvement appears in a given country. In reality, some of the countries moved from on the scale with different effects. Albania decreased the level of health system outcomes while Armenia and Georgia made progress, but lost distance to leaders in the region. On the other hand, Latvia and Estonia showed the most dynamic progress in improving the outcomes. Conclusions: Countries that have decided to implement comprehensive health reform have achieved a positive result in terms of further improvements in health system efficiency levels. Besides, a higher level of efficiency during the initial transition period generally positively determined the subsequent value of the efficiency index value, but not the dynamics of change. The paths of health system outcomes improvement are highly diverse between different countries. The instrument we propose constitutes a useful tool to evaluate the effectiveness of reform processes in post-communist countries, but more studies are needed to identify factors that may determine results obtained by individual countries, as well as to eliminate the limitations of methodology we applied.

Keywords: health system outcomes, health reforms, health system assessment, health system evaluation

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Authors: Nariman O. Kandil, Ehab K. Abou-Elkheir, Amr M. Kotb

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Effective IT governance guarantees the strategic alignment of IT and business goals, risk mitigation control, and better IT and business performance. This study seeks to examine empirically the extent of IT governance implementation within the firms listed on the Egyptian stock exchange (EGX30) and its determinants. Accordingly, 18 semi-structured interviews face to face, phone, and video-conferencing interviews using various tools (e.g., WebEx, Zoom, and Microsoft Teams) were undertaken at the interviewees’ offices in Egypt between the end of November 2019 and the end of August 2020. Results suggest that there are variances in the extent of IT Governance (ITG) implementation within the firms listed on the Egyptian stock exchange (EGX30), mainly caused by the industry type and internal and external triggers. The results also suggest that the organization size, the type of auditor, the criticality of the industry, the effective processes & KPIs, and the information intensity expertise of the CIO have a significant impact on IT governance implementation within the firms.

Keywords: effective IT governance, Egyptian market, information security, risk controls

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Authors: Sanaz Moayer, Fang Huang, Scott Gardner

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In the highly leveraged business world of today, an organisation’s success depends on how it can manage and organize its traditional and intangible assets. In the knowledge-based economy, knowledge as a valuable asset gives enduring capability to firms competing in rapidly shifting global markets. It can be argued that ability to create unique knowledge assets by configuring ICT and human capabilities, will be a defining factor for international competitive advantage in the mid-21st century. The concept of KM is recognized in the strategy literature, and increasingly by senior decision-makers (particularly in large firms which can achieve scalable benefits), as an important vehicle for stimulating innovation and organisational performance in the knowledge economy. This thinking has been evident in professional services and other knowledge intensive industries for over a decade. It highlights the importance of social capital and the value of the intellectual capital embedded in social and professional networks, complementing the traditional focus on creation of intellectual property assets. Despite the growing interest in KM within professional services there has been limited discussion in relation to multinational resource based industries such as mining and petroleum where the focus has been principally on global portfolio optimization with economies of scale, process efficiencies and cost reduction. The Australian minerals and metals mining industry, although traditionally viewed as capital intensive, employs a significant number of knowledge workers notably- engineers, geologists, highly skilled technicians, legal, finance, accounting, ICT and contracts specialists working in projects or functions, representing potential knowledge silos within the organisation. This silo effect arguably inhibits knowledge sharing and retention by disaggregating corporate memory, with increased operational and project continuity risk. It also may limit the potential for process, product, and service innovation. In this paper the strategic application of knowledge management incorporating contemporary ICT platforms and data mining practices is explored as an important enabler for knowledge discovery, reduction of risk, and retention of corporate knowledge in resource based industries. With reference to the relevant strategy, management, and information systems literature, this paper highlights possible connections (currently undergoing empirical testing), between an Strategic Knowledge Management (SKM) framework incorporating supportive Data Mining (DM) practices and competitive advantage for multinational firms operating within the Australian resource sector. We also propose based on a review of the relevant literature that more effective management of soft and hard systems knowledge is crucial for major Australian firms in all sectors seeking to improve organisational performance through the human and technological capability captured in organisational networks.

Keywords: competitive advantage, data mining, mining organisation, strategic knowledge management

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Authors: Helena Costa Oliveira, Carmem Oliveira, Rita Moutinho

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The Balanced Scorecard (BSC) is a continuous strategic monitoring model focused not only on financial issues but also on internal processes, patients/users, and learning and growth. Initially dedicated to business management, it currently serves organizations of other natures - such as hospitals. This paper presents a BSC designed for a Portuguese Acute Pain Unit (APU). This study is qualitative and based on the experience of collaborators at the APU. The management of APU is based on four perspectives – users, internal processes, learning and growth, and financial and legal. For each perspective, there were identified strategic objectives, critical factors, lead indicators and initiatives. The strategic map of the APU outlining sustained strategic relations among strategic objectives. This study contributes to the development of research in the health management area as it explores how organizational insufficiencies and inconsistencies in this particular case can be addressed, through the identification of critical factors, to clearly establish core outcomes and initiatives to set up.

Keywords: acute pain unit, balanced scorecard, hospital management, organizational performance, Portugal

Procedia PDF Downloads 144

Authors: Brandon To, Yong S. Park

Abstract:

As more battery electric vehicles are being introduced into the automobile industry, continuous advancements are constantly made in the electric vehicle space. Improvements in lithium-ion battery technology allow electric vehicles to be capable of traveling long distances. The batteries are capable of being charged faster, allowing for a sufficient range in shorter amounts of time. With increased reliance on battery technology and the changes in vehicle power trains, new challenges arise from this. Resulting electric vehicle fires caused by collisions are potentially more dangerous than those of the typical internal combustion engine. To further reduce the battery failures involved with side collisions, this project intends to reinforce an existing battery pack of an electric vehicle with honeycomb structures such that intrusion into the batteries can be minimized with weight restrictions in place. Honeycomb structures of hexagonal geometry are implemented into the side extrusions of the battery pack. With the use of explicit dynamics simulations performed in ANSYS, quantitative results such as deformation, strain, and stress are used to compare the performance of the battery pack with and without the implemented honeycomb structures.

Keywords: battery pack, electric vehicle, honeycomb, side impact

Procedia PDF Downloads 115