bluuebunny/crossref_metadata_2025 huggingface dataset:
Intuitionistic Fuzzy Synthetic Measure on the Basis of Survey Responses and Aggregated Ordinal Data
Authors: Jefmański Bartłomiej , Roszkowska Ewa , Kusterka-Jefmańska Marta
Published: December 2021

The paper addresses the problem of complex socio-economic phenomena assessment using questionnaire surveys. The data are represented on an ordinal scale; the object assessments may contain positive, negative, no answers, a “difficult to say” or “no opinion” answers. The general framework for Intuitionistic Fuzzy Synthetic Measure (IFSM) based on distances to the pattern object (ideal solution) is used to analyze the survey data. First, Euclidean and Hamming distances are applied in the procedure. Second, two pattern object constructions are proposed in the procedure: one based on maximum values from the survey data, and the second on maximum intuitionistic values. Third, the method for criteria comparison with the Intuitionistic Fuzzy Synthetic Measure is presented. Finally, a case study solving the problem of rank-ordering of the cities in terms of satisfaction from local public administration obtained using different variants of the proposed method is discussed. Additionally, the comparative analysis results using the Intuitionistic Fuzzy Synthetic Measure and the Intuitionistic Fuzzy TOPSIS (IFT) framework are presented.
An Improved Moth-Flame Optimization Algorithm with Adaptation Mechanism to Solve Numerical and Mechanical Engineering Problems
Authors: Nadimi-Shahraki Mohammad H. , Fatahi Ali , Zamani Hoda , Mirjalili Seyedali , Abualigah Laith
Published: December 2021

Moth-flame optimization (MFO) algorithm inspired by the transverse orientation of moths toward the light source is an effective approach to solve global optimization problems. However, the MFO algorithm suffers from issues such as premature convergence, low population diversity, local optima entrapment, and imbalance between exploration and exploitation. In this study, therefore, an improved moth-flame optimization (I-MFO) algorithm is proposed to cope with canonical MFO’s issues by locating trapped moths in local optimum via defining memory for each moth. The trapped moths tend to escape from the local optima by taking advantage of the adapted wandering around search (AWAS) strategy. The efficiency of the proposed I-MFO is evaluated by CEC 2018 benchmark functions and compared against other well-known metaheuristic algorithms. Moreover, the obtained results are statistically analyzed by the Friedman test on 30, 50, and 100 dimensions. Finally, the ability of the I-MFO algorithm to find the best optimal solutions for mechanical engineering problems is evaluated with three problems from the latest test-suite CEC 2020. The experimental and statistical results demonstrate that the proposed I-MFO is significantly superior to the contender algorithms and it successfully upgrades the shortcomings of the canonical MFO.
Series Representations for Uncertain Fractional IVPs in the Fuzzy Conformable Fractional Sense
Authors: Bataineh Malik , Alaroud Mohammad , Al-Omari Shrideh , Agarwal Praveen
Published: December 2021

Fuzzy differential equations provide a crucial tool for modeling numerous phenomena and uncertainties that potentially arise in various applications across physics, applied sciences and engineering. Reliable and effective analytical methods are necessary to obtain the required solutions, as it is very difficult to obtain accurate solutions for certain fuzzy differential equations. In this paper, certain fuzzy approximate solutions are constructed and analyzed by means of a residual power series (RPS) technique involving some class of fuzzy fractional differential equations. The considered methodology for finding the fuzzy solutions relies on converting the target equations into two fractional crisp systems in terms of ρ-cut representations. The residual power series therefore gives solutions for the converted systems by combining fractional residual functions and fractional Taylor expansions to obtain values of the coefficients of the fractional power series. To validate the efficiency and the applicability of our proposed approach we derive solutions of the fuzzy fractional initial value problem by testing two attractive applications. The compatibility of the behavior of the solutions is determined via some graphical and numerical analysis of the proposed results. Moreover, the comparative results point out that the proposed method is more accurate compared to the other existing methods. Finally, the results attained in this article emphasize that the residual power series technique is easy, efficient, and fast for predicting solutions of the uncertain models arising in real physical phenomena.
Ecosystem Services Research Trends: A Bibliometric Analysis from 2000–2020
Authors: Gangahagedara Ruchira , Subasinghe Shyamantha , Lankathilake Madhushan , Athukorala Wasantha , Gamage Isurun
Published: December 2021

The study of ecosystem services (ES) is becoming increasingly popular, as it plays an important role in human wellbeing, economic growth, and livelihoods. The primary goal of this research is to investigate the global trend in ES research using a rigorous systematic review of highly cited articles. The articles for this study were extracted from Science Citation Index Expanded (SCI-E), Emerging Sources Citation Index (ESCI), and Social Sciences Citation Index (SSCI) databases of Web of Science Core Collection (WoSCC) covering the period from 2000 to 2020. This study was limited to SCI-E, ESCI, and SSCI databases of the Web of Science. The term “ecosystem service/s” has been used as a research term to filter the study sample and eliminate other databases from the analysis. A citation level equal to or greater than 200 was used to further filtration of articles. This query could restrict to 128 articles that are highly cited in the selected period. Bibliometric analysis results show that, according to the author’s keywords, the “ecosystem service/s” keyword is highly connected to the “biodiversity”, “valuation”, “marine spatial planning”, and “conservation planning”. The U.S.A., Canada, China, France, and Australia are the leading countries in the cumulative number of highly cited articles and networks of co-authors. The U.S.A. is a strong contributor to ES research with China, Canada, and France. The most productive universities linked to the United States were the University of Minnesota, the University of California-Santa Barbara (UC Santa Barbara), and the Chinese Academy of Science. The most significant and compelling author is Halpern S Benjamin, who represents UC Santa Barbara. He has earned international recognition for a model he developed to analyze global data sets of anthropogenic drivers of ecological change in marine environments. The most accessed and studied fields in the ES are terrestrial, urban, and marine environments.
Interdependency Pattern Recognition in Econometrics: A Penalized Regularization Antidote
Authors: Ntotsis Kimon , Karagrigoriou Alex , Artemiou Andreas
Published: December 2021

When it comes to variable interpretation, multicollinearity is among the biggest issues that must be surmounted, especially in this new era of Big Data Analytics. Since even moderate size multicollinearity can prevent proper interpretation, special diagnostics must be recommended and implemented for identification purposes. Nonetheless, in the areas of econometrics and statistics, among other fields, these diagnostics are controversial concerning their “successfulness”. It has been remarked that they frequently fail to do proper model assessment due to information complexity, resulting in model misspecification. This work proposes and investigates a robust and easily interpretable methodology, termed Elastic Information Criterion, capable of capturing multicollinearity rather accurately and effectively and thus providing a proper model assessment. The performance is investigated via simulated and real data.
Does the Choice of Realized Covariance Measures Empirically Matter? A Bayesian Density Prediction Approach
Authors: Jin Xin , Liu Jia , Yang Qiao
Published: December 2021

This paper suggests a new approach to evaluate realized covariance (RCOV) estimators via their predictive power on return density. By jointly modeling returns and RCOV measures under a Bayesian framework, the predictive density of returns and ex-post covariance measures are bridged. The forecast performance of a covariance estimator can be assessed according to its improvement in return density forecasting. Empirical applications to equity data show that several RCOV estimators consistently perform better than others and emphasize the importance of RCOV selection in covariance modeling and forecasting.
Institutional Governance of Innovations: Novel Insights of Leadership in Russian Public Procurement
Authors: Tsygankov Sergey , Syropyatov Vadim , Volchik Vyacheslav
Published: December 2021

In the modern conditions of the post-COVID world, the transformation of the world economy in the framework of the transition to the post-industrial paradigm, and the economy of “knowledge”, the national innovation system (NIS) plays a leading role in the formation of competitive sectors of any given country. Within this setting, the performance of the Russian innovation system significantly lags behind other countries and calls for modernisation based on the modern regulatory tools, policies, and world’s leading trends. The direct import of institutions of foreign innovation systems demonstrates its limited effectiveness due to the incompleteness of institutions and mechanisms for regulating the institutional environment of the Russian economy. One of the generally recognised, leading, and the most “universal” instruments for implementing innovation policy by government institutions is the public procurement of innovation. The analysis of international experience shows that the implementation of the innovation policy via innovative public procurement has a highly heterogeneous landscape even in such a “cohesive” jurisdiction as those represented by the European Union (EU) as far as different types of policy dominate in different countries of the world. There is no clear trend towards the only one mainstream regulatory approach. In this context, the Russian experience demonstrates de facto the absence of any centralised, transparent, and effective policy expressed in such pseudo-innovative procurement as refuelling cartridges or car repairs. This paper identifies the existing institutional failures of the Russian NIS on the example of the regulation of innovative domestic procurement. It proposes ways to modernise the current policy based on the institutional and narrative approaches in order to foster its leading position in the international competition. This article shows the gaps in the literature in institutional governance of innovations and innovation procurement in Russia and points at directions for future research based on narrative economics. Outlining the present knowledge as a foundation for future research in institutional governance of innovations, this article holds implications for both academics and practitioners in the field of the innovation policies and public procurement.
Formation of a Sustainable Mechanism of Preferential VAT Taxation of Exports as Evidenced by the Russian Federation Practice
Authors: Sidorova Elena , Sebechenko Ekaterina , Kostyukhin Yury , Boboshko Diana , Kostin Alexey , Kostina Olga , Vikhrova Natalia
Published: December 2021

In this article we review the issues of applying a preferential value added tax (VAT) taxation regime on export transactions involving unlawful tax benefit claims and tax evasion. The main objective of this study is to supplement the theoretical and methodological foundations of transforming the system of indirect taxation of exports in the Russian Federation based on the analysis of legal precedents. We analyzed the foreign trade statistics for the Russian Federation and the volumes of export VAT; we also studied the court rulings in VAT-related tax disputes. Based on our analysis of the court cases, we discovered the main schemes of unlawful application of VAT preferences, such as “false exports”, introduction of additional layers of intermediaries, and use of agency services by exporting sellers. In addition, we formulated two problematic scenarios where bona fide transactions fall under the definition of such schemes. Specifically, these two scenarios include services contracts by foreign service providers that are reclassified by the tax authorities with an aim to challenge the offsetting of incoming VAT amounts and the specifics of applying VAT to transactions involving compensation-free transfer of goods to foreign legal entities. To minimize the number of tax disputes, we suggest that certain provisions of the Russian legislation are amended with more detail. The proposed innovations can positively affect international trade as they bring more easily understandable and stable conditions for the development of businesses engaged in cross-border service provisioning. At the same time, a reduction in the number of disputes based on the tax authorities’ subjective opinion of taxpayers’ activities would allow the tax authorities to concentrate on clearer and more objective criteria of tax compliance by Russian companies, thus simplifying tax administration in one of the domains of tax law.
Empirical Evidence on Factors Conditioning the Turning Point of the Public Debt–Growth Relationship
Authors: Butkus Mindaugas , Cibulskiene Diana , Garsviene Lina , Seputiene Janina
Published: December 2021

This paper contributes to the limited literature on the factors conditioning the turning point of the public debt–growth relationship. A decade after the global financial crisis, when the debt ratio in many countries was still above pre-crisis levels, the COVID-19 pandemic again increased the pressure on public finances. It revived the debate on the ability to promote economic recovery through debt-financed government expenditure. However, more intense government borrowing increases its costs and uncertainty about future taxation policy, thus potentially disturbing private consumption, investment, and economic growth. In this paper, we estimate the thresholds of indicators on which the expenditure multiplier depends, which may already imply a risk that public debt will dampen economic growth. We use a methodology of structural threshold regression to examine the varying effects that debt might have on growth using consumption, investment, taxes, and imports as threshold variables, as well as several other factors suggested by previous contributions. The applied methodology allows for the addressing of parameter heterogeneity and endogeneity to be accounted for at the same time. The main results suggest that a positive debt effect is more likely if the conditions for a high expenditure multiplier are met, that an increase in the public-debt-to-GDP ratio is not necessarily deleterious to growth if shares of private consumption and investment in GDP are high, while the tax-revenue-to-GDP ratio is low.
The Analysis of Residential Rooftop PV in Indonesia’s Electricity Market
Authors: Haryadi Fajar Nurrohman , Hakam Dzikri Firmansyah , Ajija Shochrul Rohmatul , Simaremare Arionmaro Asi , Aditya Indra Ardhanayudha
Published: December 2021

This study aimed to examine the customer interest in using rooftop PV considering the economic background and customer profile in Indonesia’s electricity market using primary survey data with potential and existing (households and industries) respondents. This research uses logit model regression to analyze the impact of the demographic background of respondents and uses exploratory factor analysis (EFA) to understand the reasons why the existing users utilize rooftop PV at their homes. The results show that education, residence location, and income can positively and significantly affect the probability of using rooftop PV as the source of electricity. Then, there are several factors that influence the use of rooftop PV, such as easily finding it in their area, having concern for the environment, following trends, and loyalty. Some disadvantages of installing rooftop PV are felt by users, such as relatively high installation cost and frequent overheating during usage. Regarding customer satisfaction, most of the respondents from both households and industries answered that they were satisfied with their rooftop’s PV. Consumers say that the benefits they obtain are comparable to the required installation costs, and the majority of consumers also said that the rooftop PV worked well and did not need many repairs every month, so consumers did not need to spend significant money on it.
Factors Determining the Competitive Strategic Positions of the SMEs in Asian Developing Nations: Case Study of SMEs in the Agricultural Sector in Sri Lanka
Authors: Prasanna RPIR , Upulwehera JMHM , Senarath BDTN , Abeyrathne GAKNJ , Rajapakshe PSK , Jayasundara JMSB , Ekanayake EMS , Gamage Sisira Kumara Naradda
Published: December 2021

Economic globalization has rapidly intensified the competition among businesses. Therefore, it is pivotal that SMEs follow competitive strategic positions and adopt strategic methods in order to confront the various challenges in this era. This study assessed the factors that determine the competitive strategic position of SMEs in the developing nations of Asia by considering the agro-based SMEs in Sri Lanka as a case study. By using primary data of 463 SMEs, the study estimated a binary logistic regression model to deal with the research subject. The findings revealed seven significant strategic variables: innovation in product and marketing, business exhibition in the local setting, gender, strategic market location, sustainable business practices, marketing efficiency, and business reputation and superior services. Moreover, the study identified and commented on seven insignificant variables: specialization in production, experience in the business field, experience in attending business exhibitions at overseas setting, credit market accessibility, provision of high-quality products, research and development, and strategic firm location, which are relevant in developed countries. Therefore, the government and policymakers must initiate measures to establish a more favorable business environment for SMEs to gain competitive advantage from these variables in the near future to permit an ameliorated and strong SME sector in Sri Lanka.
Trauma-Informed School Strategies for SEL and ACE Concerns during COVID-19
Authors: Scott Jesse , Jaber Lindsey S. , Rinaldi Christina M.
Published: December 2021

The precarious circumstances associated with the COVID-19 pandemic have raised important questions concerning the potential impact on child and adolescent development. For instance, how might this disruption influence social and emotional learning (SEL) and affect adverse childhood experiences (ACEs)? Moreover, what protective practices may be put in place to mitigate risks? The purpose of this critical review is to engage with these questions. Relevant research findings published before and during pandemic contexts are presented. Connections between SEL, ACEs and past social disruptions are substantiated in the literature. Additionally, preliminary evidence has elucidated variables associated with ACEs and SEL concerns during the pandemic. For instance, research suggests that students from socially disadvantaged positions may be disproportionately impacted by these issues. Actionable trauma-informed recommendations for educators are discussed, including creating safe school environments and adopting a strength-based perspective.
Sustainability Awareness of In-Service Physical Education Teachers
Authors: Baena-Morales Salvador , Ferriz-Valero Alberto , Campillo-Sánchez Javier , González-Víllora Sixto
Published: December 2021

Physical Education has been described as a subject with unique characteristics that can contribute to achieving Sustainable Development Goals. However, an analysis of PE teachers’ (PETs) sustainability consciousness has not yet been conducted. For this purpose, a total of 203 PETs completed the validated SCQ-S instrument to measure the three dimensions of sustainable development in three components of consciousness (attitudes, knowledge and behaviours). The results obtained show that the PETs have a high consciousness for sustainable development (SD), except for attitudes within the economic dimension. Sex has been identified as a variable that determines awareness in sustainability with significantly higher scores for women in all the variables evaluated, except for knowledge and behaviour in the social dimension. These findings provide new knowledge within the Physical Education and SD paradigm, serving as a link for future research that aims to harness the benefits of Physical Education for the sustainability of the planet.
STEM Students’ Perceptions on Emergency Online Learning during the COVID-19 Pandemic: Challenges and Successes
Authors: Selco Jodye I. , Habbak Mariam
Published: December 2021

Declaration of the COVID-19 pandemic by the World Health Organization in 2020 forced many schools to switch to emergency virtual instruction. This situation provided an opportunity to explore the effectiveness of online learning from students’ perspectives. To discover best practices for online learning, 584 STEM students at California State Polytechnic University Pomona (Cal Poly Pomona) were surveyed about their Spring and Fall 2020 experiences. Some of the obstacles students faced were adapting to a new lifestyle, feeling disconnected, managing schedule and workload, and overcoming distractions. Despite difficulties, 61% of students benefited from the flexibility, convenience, and increased productivity. The time students normally spent commuting to and parking on campus was instead spent getting more sleep, studying, working extra hours, spending time with family, and practicing self-care. Another major benefit was the increased accessibility to course materials posted online. Major themes from students’ responses were belonging, organization and transparency, and the need for real-world applications. Incorporating these strategies enhance the effectiveness of teaching methods. Responses along with some problem-solving suggestions that can improve the effectiveness of both online and in-person learning are discussed.
The Language of “Rate of Change” in Mathematics
Authors: Avgerinos Evgenios , Remoundou Dimitra
Published: December 2021

Language is an essential aspect of teaching and learning mathematics. It is necessary for communication, the transmission of concepts and ideas, and the formation of meaning of mathematical concepts. In mathematics, besides symbols, which are usually common among different languages, words and expressions are used, which may invoke different concept images to students in various languages. Some words are used in mathematics and in everyday language with different meanings, while others are used only in mathematics or in mathematics and other disciplines in similar but non-identical ways. In Mathematical Analysis, the used vocabulary is gradually enhanced, and the concepts are defined in a more formal way. In the current study, the language used regarding mathematics of change is examined, focusing on “rate of change”, and its relation to misconceptions among students.
Parameterized 2D Field Model of a Switched Reluctance Motor
Authors: Bieńkowski Krzysztof , Szulborski Michał , Łapczyński Sebastian , Kolimas Łukasz , Cichecki Hubert
Published: December 2021

This work aimed to develop a parameterized, two-dimensional field model of a switched reluctance motor (SRM). The main task of the developed model was to calculate the value of the electromagnetic torque for various positions of the rotor. Based on these calculations, the characteristics of the electromagnetic torque were determined depending on the position of the rotor angle φ for the current function I (T = f (φ, I)). Using the model, it was possible to additionally observe the phenomena occurring in the motor winding, e.g., distributions, isolines of magnetic potential, induction, and to calculate the values of the temperature. The parameterized structural elements that made up the entire model can be freely changed and, thus, the results for various structures can be obtained. Thanks to this, it was possible to evaluate and compare motor of different designs. To validate the model, measurements were conducted on real-scale reluctance motors, and families of electromagnetic torque characteristics were obtained for various design cases. The results received from the tested motors were juxtaposed with simulation results procured via the model. Based on this comparison, it was possible to determine the accuracy of the model’s operation.
Mutual Inductance Calculation of Circular Coils Sandwiched between 3-Layer Magnetic Mediums for Wireless Power Transfer Systems
Authors: Yang Minsheng , Li Zhongqi , Zhang Min , Wan Jingying
Published: December 2021

The mutual inductance between coils directly affects many aspects of performance in wireless power transmission systems. Therefore, a reliable calculation method for the mutual inductance between coils is of great significance to the optimal design of transmission coil structures. In this paper, a mutual inductance calculation for circular coils sandwiched between 3-layer magnetic mediums in a wireless power transmission system is proposed. First, the structure of circular coils sandwiched between 3-layer magnetic mediums is presented, and then a mutual inductance model of the circular coils is established. Accordingly, a corresponding magnetic vector potential analysis method is proposed based on Maxwell equations and the Bessel transform. Finally, the mutual inductance calculation method for circular coils between 3-layer magnetic mediums is obtained. The correctness of the proposed mutual inductance calculation method is verified by comparing the calculated, simulated, and measured mutual inductance data.
Estimation and Interpretation of Machine Learning Models with Customized Surrogate Model
Authors: Ali Mudabbir , Khattak Asad Masood , Ali Zain , Hayat Bashir , Idrees Muhammad , Pervez Zeeshan , Rizwan Kashif , Sung Tae-Eung , Kim Ki-Il
Published: December 2021

Machine learning has the potential to predict unseen data and thus improve the productivity and processes of daily life activities. Notwithstanding its adaptiveness, several sensitive applications based on such technology cannot compromise our trust in them; thus, highly accurate machine learning models require reason. Such models are black boxes for end-users. Therefore, the concept of interpretability plays the role if assisting users in a couple of ways. Interpretable models are models that possess the quality of explaining predictions. Different strategies have been proposed for the aforementioned concept but some of these require an excessive amount of effort, lack generalization, are not agnostic and are computationally expensive. Thus, in this work, we propose a strategy that can tackle the aforementioned issues. A surrogate model assisted us in building interpretable models. Moreover, it helped us achieve results with accuracy close to that of the black box model but with less processing time. Thus, the proposed technique is computationally cheaper than traditional methods. The significance of such a novel technique is that data science developers will not have to perform strenuous hands-on activities to undertake feature engineering tasks and end-users will have the graphical-based explanation of complex models in a comprehensive way—consequently building trust in a machine.
Design and Experiments of the Sheet Electron Beam Transport with Periodic Cusped Magnetic Focusing for Terahertz Traveling-Wave Tubes
Authors: Zhang Changqing , Pan Pan , Chen Xueliang , Su Siming , Song Bowen , Li Ying , Lü Suye , Cai Jun , Gong Yubin , Feng Jinjun
Published: December 2021

The successful transport of a sheet electron beam under the periodic cusped magnet (PCM) focusing at the terahertz frequencies is reported. The sheet beam with a current density of 285 A/cm2 is intended for the developing G-band sheet-beam traveling-wave tube (TWT) whose operating voltage is nominally 24.5 kV. A beamstick was developed to validate the design of the electron optics system, which is considered as the most challenging part for developing a sheet-beam device. A beam transmission ratio of 81% is achieved over a distance of 37.5 mm at a cathode voltage of −25.0 kV. The total current and the collector current were measured to be 125 and 102 mA, respectively. The experimental results are promising, demonstrating that the PCM scheme is capable of focusing a high-current-density sheet beam and hence can find use in the terahertz TWTs, offering the advantages of compact size and light weight.
Investigation of Mean-Time-to-Failure Measurements from AlGaN/GaN High-Electron-Mobility Transistors Using Eyring Model
Authors: Chakraborty Surajit , Kim Tae-Woo
Published: December 2021

We present the mean-time-to-failure (MTTF) calculations for AlGaN/GaN high-electron-mobility transistors (HEMTs) using two independent acceleration factors. MTTF predictions are generally calculated through the Arrhenius relationship, based on channel temperature and acceleration, depend only on one parameter. Although the failure modes of the AlGaN/GaN HEMTs depend largely on the applied electric fields, the Eyring model is introduced to investigate both voltage and temperature dependent degradation of AlGaN/GaN devices. In anticipation of adequate MTTF values, studies were conducted on non-commercial devices. Further, we distinguished the cumulative failure percentages through the Weibull and log-normal distributions. We also explored the increase in gate leakage current at high temperatures for early device deterioration.
A Novel Low Voltage Selective Circuit Breaker with Additional Current Path
Authors: Rozegnał Bartosz , Albrechtowicz Paweł , Cisek Piotr
Published: December 2021

The subject of the article is a description of the operating principle of the new proposal of the selective circuit breaker, which is an extension of the existing selective devices. The solution proposed in the article allows one to increase the selectivity range of classic selective circuit breakers. In the case of networks with high values of short-circuit loop impedance, operating at reduced supply voltage, the proposed solution will not limit the short-circuit current too excessively as it is in the case of classic solutions. This advantage will allow for the correct reaction of the protections preceding them. The article presents the structure and analysis of the selection of parameters of the proposed solution. The results of simulation calculations have also been illustrated.
The Impact of Government Subsidies on Single-Channel Recycling Based on Recycling Propaganda
Authors: Zhang Fangfang , Wang Hao , Wu Xiaoyu
Published: December 2021

The recycling of waste products is an important way to achieve global sustainable development. To analyze the impact of different objects of government subsidies on single-channel recycling based on recycling propaganda, four theory game models of single-channel recycling based on government subsidies and recycling propaganda are established. By comparing and analyzing the effects of different subsidies and propaganda strategies on the recycling of waste products in the four models, this article mainly draws the following conclusions: the government selecting different objects to subsidize has the same effect on the unit recycling price, quantity, and revenue of waste products; when the government subsidizes the processors, the consigned recycling price of waste products will increase, but when the government subsidizes recyclers, it will decrease; when the propagandist is determined, the optimal value of propaganda is related to the sensitivity of residents to the unit recycling price of waste products, the unit propaganda of waste products, and the expenses of propagating waste products.
Photovoltaic Evaporative Chimney I–V Measurement System
Authors: Casado Pablo , Blanes José M. , Valero Francisco Javier Aguilar , Torres Cristian , Lucas Miralles Manuel , Ruiz Ramírez Javier
Published: December 2021

The photovoltaic evaporative chimney is a novel solar-cooling system that serves a double purpose: it increases the efficiency of the photovoltaic (PV) panels and it cools down a water stream which can be used to dissipate the heat from a refrigeration cycle. One of the major issues arising from the operation of the chimney is the temperature stratification in the panel due to the movement of the air in the chimney. This effect can trigger the activation of the bypass diodes of the module, creating local maximum power points (MPP) that can compromise the grid-tied inverter tracking. To fill this gap, this paper deals with the design and implementation of an I–V curve measurement system to be used in the performance analysis of the system. The I–V curve tracer consists of a capacitive load controlled by a single board computer. The final design includes protections, capacitor charging/discharging power electronics, remote commands inputs, and current, voltage, irradiance, and temperature sensors.The results show that the modules bypass diodes are not activated during the tests, and no local MPPs appear. Moreover, the curves measured show the benefits of the photovoltaic chimney: the cooling effect increases the power generated by the PV panels by around 10%.
Energy Losses Due to Imperfect Payment Infrastructure and Payment Instruments
Authors: Melnychenko Oleksandr
Published: December 2021

One of the strategic objectives of the European Union is a reduction in greenhouse gas emissions and improvement of energy efficiency by at least 32.5% in different areas of the economy by 2030. However, little is known about the impact of payment in retail on energy consumption. The purpose of this paper is to assess the chain of losses of time and energy, and therefore financial losses, that occur due to the imperfection of payment infrastructure and instruments using data of cashiers’ working time. The research is based on a regression analysis method, where the energy cost per payment transaction is considered in this study as a function of the number of customers per hour and the energy cost. The results of the panel models highlight that the number of customers per hour has a negative impact on the cost of energy per payment transaction. Furthermore, modern means and methods of payment, including cryptocurrencies, do not solve the problem of the excessive time that it takes to service payments, which entails a waste of energy and money. The empirical results give valuable insights into how to best organise payment in retail to achieve lower energy costs and improve energy efficiency in payment infrastructure.
Assessing the Effects of Uncertain Energy and Carbon Prices on the Operational Patterns and Economic Results of CHP Systems
Authors: Benalcazar Pablo , Kaszyński Przemysław , Kamiński Jacek
Published: December 2021

In the power and heat sectors, the uncertainty of energy and carbon prices plays a decisive role in the rationale for decommissioning/repurposing coal-fired CHP (combined heat and power) systems and on investment decisions of energy storage units. Therefore, there is a growing need for advanced methods that incorporate the stochastic disturbances of energy and carbon emission prices into the optimization process of an energy system. In this context, this paper proposes an integrated method for investigating the effects of uncertain energy and carbon prices on the operational patterns and financial results of CHP systems with thermal energy storage units. The approach combines mathematical programming and Monte Carlo simulation. The computational process generates feasible solutions for profit maximization considering the technical constraints of the CHP system and the variation of energy and carbon emission prices. Four scenarios are established to compare the operational patterns and economic performance of a CHP system in 2020 and 2030. Results show that in 2020, there is an 80% probability that the system’s annual profit will be less than or equal to €30.98 M. However, at the same probability level, the annual profit in 2030 could fall below €11.88 M. Furthermore, the scenarios indicate that the incorporation of a thermal energy storage unit leads to higher expected profits (€0.74 M in 2020 and €0.71 M in 2030). This research shows that coal-fired CHP plant operators will face costly risks and potentially greater challenges in the upcoming years with the increasing regulatory and financial pressure on CO2 emissions and the EU’s plan of phasing out fossil fuels from electricity and heat generation.
Development of an Integrated Performance Design Platform for Residential Buildings Based on Climate Adaptability
Authors: Li Zhixing , Tian Mimi , Zhao Yafei , Zhang Zhao , Ying Yuxi
Published: December 2021

Building energy waste has become one of the major challenges confronting the world today, so specifications and targets for building energy efficiency have been put forward in countries around the world in recent years. The schematic design stage matters a lot for building energy efficiency, while most architects nowadays are less likely to make energy efficiency design decisions in this stage due to the lack of necessary means and methods for analysis. An integrated multi-objective multivariate framework for optimization analysis is proposed for the schematic design stage in the paper. Here, the design parameters of the building morphology and the design parameters of the building envelope are integrated for analysis, and an integrated performance prediction model is established for low-rise and medium-rise residential buildings. Then, a comparison of the performance indicators of low-rise and medium-rise residential buildings under five typical urban climatic conditions is carried out, and the change patterns of the lighting environment, thermal environment, building energy demand, and life cycle cost of residential buildings in each city under different morphological parameters and design parameters of the building envelope are summarized. Specific analysis methods and practical tools are provided in the study for architectural design to ensure thermal comfort, lighting comfort, low energy consumption, and low life-cycle cost requirement, and this design method can inspire and guide the climate adaptation analysis and design process of low-rise and medium-rise residential buildings in China, improve architects’ perception of energy-saving design principles of low-rise and medium-rise residential buildings on the ontological level, as well as provide them with a method to follow and a case to follow in the actual design process.
Accelerating Building Energy Retrofitting with BIM-Enabled BREEAM-NL Assessment
Authors: Simhachalam Vyshali , Wang Tong , Liu Yan , Wamelink Hans , Montenegro Lorena , van Gorp Geert
Published: December 2021

The Paris Agreement requires building retrofitting practices to be more efficient and effective. However, the current practice for building energy retrofitting is lacking behind, and one reason for that is the time-consuming process of energy credit evaluation. Energy performance assessment such as BREEAM-NL in the Netherlands could apply a more automatic approach with the help of building information modelling (BIM) for an efficient building energy retrofitting evaluation process. However, to what extent BIM can help in accelerating energy performance evaluation in the BREEAM-NL certification process is under-examined. This paper first combines literature findings with practical interviews from a case study organization to present a holistic overview of the potential for automating energy-related credits evaluation in BREEAM-NL using BIM. To understand the possible impacts of such transition, a responsible, accountable, consulted, and informed (RACI) matrix is developed to map the impacts on different actors involved. Furthermore, to help practitioners in an organizational context to adopt a BIM-enabled energy credits assessment workflow, the case study organization is studied to (1) understand their current BIM use status; (2) propose a suitable starting point to take toward a BIM-enabled energy performance assessment for building energy retrofitting. Finally, the proposed starting point is demonstrated using a customized application, and the project team’s feedback is used to verify its efficiency and future directions are identified.
The CO2 Emission Efficiency of China’s Hotel Industry under the Double Carbon Objectives and Homestay Growth
Authors: Li Jiachen , Li Xue , Chen Chiyin
Published: December 2021

Hotels emit large amounts of CO2 when providing services. Carbon neutrality objectives and the growth of homestays have forced hotel managers to pay more attention to carbon reduction. First, this paper adopted the input–output method to calculate hotel CO2 emissions. It was found that the amount of CO2 emissions in the hotel industry decreased from the year of 2016 to 2018, and there are structural differences in the CO2 emissions of the hotel industry in China. Furthermore, this paper adopted the three-stage SBM-DEA model to evaluate hotel CO2 emission efficiency in 30 provinces in China. The results show that CO2 emission efficiency increased significantly when environmental factors were eliminated. A close observation of different regions shows that the eastern region has a higher CO2 emission efficiency than the western and middle regions. The emergence of homestays has led to increased input slacks in the labor and energy consumption of hotels, which has a negative effect on efficiency indirectly. Finally, implications and recommendations for the hotel industry are proposed.
An Overview of Voltage Boosting Techniques and Step-Up DC-DC Converters Topologies for PV Applications
Authors: de Carvalho Márcio R. S. , Neto Rafael C. , Barbosa Eduardo J. , Limongi Leonardo R. , Bradaschia Fabrício , Cavalcanti Marcelo C.
Published: December 2021

The development of technologies to improve the performance of photovoltaic (PV) module integrated converters (MICs) is fundamental to increase the use of distributed generation systems with photovoltaic power source in large urban centers, mainly for complex residential roofs. For two-stage PV MICs, high step-up DC-DC converters are required to boost the low PV module voltage to a higher voltage, in order to suit the DC bus voltage requirements of grid-tied inverters. Thus, to support researchers interested in developing DC-DC power conversion for PV microinverters, this paper classifies the DC-DC converters according to their operational and constructive characteristics and presents some elementary voltage-boosting techniques to aid in analyzing and understanding more complex topologies. Finally, high step-up DC-DC converters based on magnetic coupling and switched capacitor widely cited by important works related to PV applications are presented, with their principles of operation analysed in a simple and objective way, but sufficient to understand their capability to provide high voltage gain. The approach presented by this paper leads to insight into how to place the energy storage elements to create new topologies of DC-DC converters, so that high voltage gain is achieved, and how to analise the high voltage gain capability of complex topologies
Three-Dimensional TID Hardening Design for 14 nm Node SOI FinFETs
Authors: Lu Peng , Yang Can , Li Yifei , Li Bo , Han Zhengsheng
Published: December 2021

The fin field-effect transistor (FinFET) has been the mainstream technology on the VLSI platform since the 22 nm node. The silicon-on-insulator (SOI) FinFET, featuring low power consumption, superior computational power and high single-event effect (SEE) resistance, shows advantages in integrated circuits for space applications. In this work, a rad-hard design methodology for SOI FinFETs is shown to improve the devices’ tolerance against the Total Ionizing Dose (TID) effect. Since the fin height direction enables a new dimension for design optimization, a 3D Source/Drain (S/D) design combined with a gate dielectric de-footing technique, which has been readily developed for the 14 nm node FinFETs, is proposed as an effective method for SOI FinFETs’ TID hardening. More importantly, the governing mechanism is thoroughly investigated using fully calibrated technology computer-aided design (TCAD) simulations to guide design optimizations. The analysis demonstrates that the 3D rad-hard design can modulate the leakage path in 14 nm node n-type SOI FinFETs, effectively suppress the transistors’ sensitivity to the TID charge and reduce the threshold voltage shift by >2×. Furthermore, the rad-hard design can reduce the electric field in the BOX region and lower its charge capture rate under radiation, further improving the transistor’s robustness.
Plant Biomass Production in Constructed Wetlands Treating Swine Wastewater in Tropical Climates
Authors: Sandoval-Herazo Mayerlin , Martínez-Reséndiz Georgina , Fernández Echeverria Eduardo , Fernández-Lambert Gregorio , Sandoval Herazo Luis Carlos
Published: December 2021

The production of both aboveground and belowground plant biomass in constructed wetlands (CW) is a poorly understood topic, although vegetation plays an important role in the process of pollutant removal from wastewater. The objective of this study was to evaluate the aboveground and belowground biomass production of Typha latifolia and Canna hybrids in a large-scale constructed wetland treating swine wastewater in tropical climates. Parameters, such as temperature, DO, pH, COD, TSS, TN, TP, and TC, as well as destructive and non-destructive biomass, were evaluated. It was found that, despite the high concentrations of pollutants, the vegetation adapted easily and also grew healthily despite being exposed to high concentrations of pollutants from swine water. Although Typha latifolia (426 plants) produced fewer plants than Canna hybrids (582 plants), the higher biomass of the Typha latifolia species was slightly higher than that of Canna hybrids by 5%. On the other hand, the proximity of the water inlet to the system decreased the capacity for the development of a greater number of seedlings. As for the elimination of pollutants, after treatment in the constructed wetland, COD: 83.6 ± 16.9%; TSS: 82.2 ± 17.7%; TN: 94.4 ± 15.8%; TP: 82.4 ± 23.2%; and TC: 94.4 ± 4.4% were significantly reduced. These results show that wetlands constructed as tertiary systems for the treatment of swine wastewater produce a large amount of plant biomass that significantly helps to reduce the concentrations of pollutants present in this type of water in tropical areas. The use of these plants is recommended in future wetland designs to treat swine wastewater.
Production and Physicochemical Characterization of Analog Rice Obtained from Sago Flour, Mung Bean Flour, and Corn Flour Using Hot Extrusion Technology
Authors: Sumardiono Siswo , Budiyono Budiyono , Kusumayanti Heny , Silvia Nada , Luthfiani Virginia Feren , Cahyono Heri
Published: December 2021

Extrusion technology allows the preparation of analog rice, an artificial product made of carbohydrate sources other than rice, with characteristics similar to natural rice. In this study, we aimed at determining the effect of composition and temperature on the nutritional content of analog rice obtained using heat extrusion technology. The physical properties and acceptability of the resulting product were also studied. Skim milk, sago, mung bean, and corn flour as well as the binder carboxymethyl cellulose (CMC) were used. The procedure was conducted in four stages: raw-material preparation, formulation, physicochemical evaluation, and sensory property evaluation. The best analog rice formula was established as 50% sago flour, 30% corn flour, 19.2% mung bean flour, 0.4% skim milk, and 0.4% CMC. The panelists’ most preferred rice analog formula was the one with the highest sago starch and skim milk content. The extrusion temperature did not significantly affect the nutrient content. However, it had a considerable impact on the thermal profile and physical properties, such as appearance and granular morphology.