Renewal Model Research Articles

Copula-based multivariate renewal model for life-cycle analysis of civil infrastructure considering multiple dependent deterioration processes

Copula-based multivariate renewal model for life-cycle analysis of civil infrastructure considering multiple dependent deterioration processes

Towards solar extractivism? A political ecology understanding of the solar energy and agriculture boom in rural China

Contemporary global climate change imperative has stimulated innovative technological systems to combine renewable energy production and other socioeconomic functions, which offer promising solutions to materialize both climate change mitigation and developmental targets. Agrivoltaics—an array of colocation models of solar photovoltaic (PV) infrastructure and agriculture—are becoming increasingly popular across the world and are widely considered a laudable green development model. Since circa 2013, agrivoltaics have started to diffuse across China, with promises of multiple socioeconomic and ecological benefits. Different from existent studies that mostly took apolitical innovation diffusion frameworks, this article draws on an in-depth case study and multiple secondary sources including information on 421 agrivoltaic projects to approach the proliferation of agrivoltaics in China through a political ecology lens. It finds that the diffusion of agrivoltaics in China has been driven neither by technological superiority nor by market-business viability but by a salient logic of solar extractivism in the name of green development. The solar extractivism is featured by: large-scale (agricultural) land acquisition, prioritization of solar electricity production, domination of renewable industries, deep engagement from local state, discourses of green transition and inclusive development, exclusionary enforcement techniques, and neglect of local socioecological systems. The stark contrast between discourses and realities reveals that the deployment of agrivoltaics embodies solar extractivism and the implicated “green agenda” served rather as a legitimation strategy for resource extraction. The solar extractivism perspective cautions against the fetishism of renewables and relevant green infrastructures in popular green development discourses and calls for critical examination of renewable integrative technical models through social justice lenses.

Second Order Runge-Kutta Method in Solving Renewable Natural Resources Model Case Study: Fishes and Water Resources Management

This research presents a study of a dynamical system which models natural resources. Using fishes and water resources as the case study. In this work a model equation was used to determine the density of the resources. We also introduced second stage Runge Kutta method, which was used to obtain the result for harvesting terms from 10% to 50% producing the population of life in the pond after each harvesting.
 In this research work, the solution of a dynamic system that can model natural resources using the second stage Runge-Kutta method was reported. To actualize this result, a model, a first order ordinary differential equation and the famous Runge-Kutta second stage method is used. Harvesting terms from 10% to 50% is used for the iteration to demonstrate the validity of the result. The result of this study was applied to the population of fish in a pond, which is a renewable natural resource, with great success.
 In line with the objectives stated at the beginning of the work, the results of this research has shown that by applying the second order Runge-Kutta method, the solution of a dynamical system can be obtained and applied to model natural resources with great success.

How Transformative Business Model Renewal Leads to Sustained Exploratory Business Model Innovation in Incumbents: Insights from a System Dynamics Analysis of Case Studies

The digital era and mounting sustainability pressures have reinforced incumbents’ need to respond to radical innovation through business model innovation. Despite advancements in the literature on incumbent business model innovation, there are still open debates regarding strategies for achieving systematic innovation and poor integration between the literature on managing multiple business models and the strategic management of business model innovation. To address these gaps, we investigated three Brazilian incumbents that developed systematic business model innovation processes and analyzed their evolution. We followed a multiple case study methodology, deploying system dynamics as an analytical lens. Our findings showed that the evolution of innovation departments from business model renewal to exploration is based on a systemic tension between solving the core problems of the business and creating openness to innovation, innovation capabilities, and resources. By assigning the innovation departments a vital role in the renewed business model and exploring synergies to manage multiple business models, the companies create a “buffer” to sustain exploratory business model innovation. We suggest that the strategy for conducting business model renewal matters, especially when the renewal is transformative, aiming to shape the future. We contribute to incumbent business model innovation theory by showing the system dynamics behind the evolution from business model renewal to exploration and by connecting the management of parallel business models to the strategic management of business model innovation.

Optimal renewable energy export strategies of islands: Hydrogen or electricity?

Renewable energy has the characteristics of wide distribution, sustainable use and low impact on the environment, which is suitable for application and promotion in the island area. Given the concerns about wind and PV curtailment of energy-rich islands, it is potentially a good idea to export extra renewable energy to the mainland. The aim of this paper is to investigate the economic viability of transforming renewable energy into exportable electricity or hydrogen. A comprehensive renewable energy system model is developed based on the P-graph to simulate an energy system, which integrates electricity, heat and hydrogen on a virtual island. Solar, wind, wave and biomass are the main renewable energy sources in the developed energy system. The objective includes the construction cost, operating cost, and also environmental cost, which is related to the greenhouse gas footprint. Findings from the case study show that extra renewable energy exporting by electricity is cheaper than using hydrogen for the studied island, and the optimal dispatch structure can deliver 51 GWh of electricity annually for 292 M CNY (about 42 M EUR). A sensitivity analysis of export prices and renewable energy uncertainty verifies the economics of electricity export.

An integrate-and-fire approach to Ca2+ signaling. Part I: Renewal model

In computational neuroscience integrate-and-fire models capture the spike generation by a subthreshold dynamics supplemented by a simple fire-and-reset rule; they allow for a numerically efficient and analytically tractable description of stochastic single cell as well as network dynamics. Stochastic spiking is also a prominent feature of Ca2+ signaling which suggests to adopt the integrate-and-fire approach for this fundamental biophysical process. The model introduced here consists of two components describing 1) activity of clusters of inositol-trisphosphate receptor channels and 2) dynamics of the global Ca2+ concentrations in the cytosol. The cluster dynamics is given in terms of a cyclic Markov chain, capturing the puff, i.e., the punctuated release of Ca2+ from intracellular stores. The cytosolic Ca2+ concentration is described by an integrate-and-fire dynamics driven by the puff current. For the cyclic Markov chain we derive expressions for the statistics of the interpuff interval, the single-puff strength and the puff current assuming constant cytosolic Ca2+. The latter condition is often well approximated because cytosolic Ca2+ varies much slower than the cluster activity does. Furthermore, because the detailed two-component model is numerically expensive to simulate and difficult to treat analytically, we develop an analytical framework to approximate the driving puff current of the stochastic cytosolic Ca2+ dynamics by a temporally uncorrelated Gaussian noise. This approximation reduces our two-component system to an integrate-and-fire model with a nonlinear drift function and a multiplicative Gaussian white noise, a model that is known to generate a renewal spike train, i.e., a point process with statistically independent interspike intervals. The model allows for fast numerical simulations, permits to derive analytical expressions for the rate of Ca2+ spiking and the coefficient of variation of the interspike interval, and to approximate the interspike interval density and the spike train power spectrum. Comparison of these statistics to experimental data is discussed.

Uniform asymptotics for ruin probabilities of a time-dependent bidimensional renewal risk model with dependent subexponential claims

This paper considers a continuous-time bidimensional renewal risk model with subexponential claims. In this model, the claim size vectors and their inter-arrival times form a sequence of independent and identically distributed random vectors following some general dependence structures introduced by [T. Jiang, Y. Wang, Y. Chen and H. Xu, Uniform asymptotic estimate for finite-time ruin probabilities of a time-dependent bidimensional renewal model, Insur. Math. Econom. 64 (2015), pp. 45–53.]. We not only extend the results of [T. Jiang, Y. Wang, Y. Chen and H. Xu, Uniform asymptotic estimate for finite-time ruin probabilities of a time-dependent bidimensional renewal model, Insur. Math. Econom. 64 (2015), pp. 45–53.] under some weak conditions, but we also obtain an asymptotic estimate of the finite-time sum-ruin probability. Furthermore, when the distributions of claim sizes have nonzero lower Karamata indices, some explicit asymptotic formulas are established for the infinite-time ruin probabilities.

Enhancing the cosmetics industry sustainability through a renewed sustainable supplier selection model

ABSTRACT The cosmetics industry requires a long-term sustainable strategy to balance its continuously growing trend worldwide and its resources consumption. In this view, the suppliers’ selection process is gaining more attention affecting products’ overall sustainability. The objective of this contribution is hence to develop and validate the Cosmetics Sustainable Supplier Selection (C-SSS) model allowing the selection of sustainable suppliers for the cosmetic industry, evaluating them in an objective and balanced manner. The model was built relying on both scientific and grey literature, by incorporating the characteristics of existing SSS models usually used separately. The C-SSS enabled to integrate the EMM approach (to reduce the subjectivity), the ANP approach (to evaluate criteria interconnections), and the TOPSIS and ELECTRE models (to create a hybrid compensation model) to support managers in objectively selecting the most sustainable suppliers. The C-SSS model was applied and validated through an industrial use case in a cosmetics Italian company.

Optimal sizing and assessment of grid-tied hybrid renewable energy system for electrification of rural site

In the developing countries, rural and remote sites are rarely connected with the national grid due to the lack of transmission and distribution infrastructure. The development of hybrid renewable energy model is an alternate solution to provide electricity accessibility in such areas. In the present research work, a grid-connected hybrid system model has been developed based on the available renewable resources. The proposed model consists of local renewable sources i.e., solar and biomass along with batteries for storage purposes. Major objectives of the study are to optimize the sizing of PV panels and batteries with power sales or purchases from the grid. The net present cost of the system has been minimized which is subjected to power reliability, SOC of batteries, upper and lower bound of SPV and batteries. Discrete Harmony Search (DHS) Algorithm has been adopted to optimize the system. Among the various considered scenarios, optimal configuration includes 30 kW biomass, 83.50 kWp solar PV, 78.70 kW converter and 38.40 kWh battery bank. Further, the optimization result yields the minimum cost of energy and net present cost as 4.66 INR/kWh and 13.07 million INR respectively.

Design of Renewable Energy Consumption Scheduling Model Based on Quantitative Feedback Theory

In the renewable energy consumption scheduling, due to the large fluctuation of wind power output, the renewable energy consumption rate is low, and the energy consumption scheduling effect is poor. Therefore, a new renewable energy consumption scheduling model based on quantitative feedback theory is designed. For the first time, calculate the output response of wind power generation, obtain the output change rate of the wind farm at the time scale, and determine the response curve of wind power generation according to the power generation process is divided into three stages: the initial stage, the peak stage and the end stage, and the response output during the peak period, so as to obtain the transfer rate of output during the peak period. Build a mathematical model of renewable energy power generation, calculate the output state of wind power generation, and analyze the output characteristics of renewable energy storage system; Secondly, the objective weight coefficient of renewable energy consumption is determined by using quantitative feedback theory, the objective function of renewable energy consumption is constructed, the power injected by parameter nodes is determined, the quantitative feedback controller is designed by using loop shaping technology, the control structure of two degrees of freedom is determined, the objective function of renewable energy consumption is constructed, and the constraint range of renewable energy consumption capacity is determined according to static constraints such as current constraints and voltage constraints; Then, the quantitative feedback theoretical controller is designed, the input and output transfer functions of the consumption system are determined, and the renewable energy consumption scheduling model is constructed. The renewable energy consumption scheduling model is solved by particle swarm optimization through a variety of index parameters in the renewable energy consumption determined by the QFT controller. The experimental results show that the proposed model can effectively improve the renewable energy consumption rate and optimize the consumption scheduling effect.

Benefits Evaluation Method of an Integrated Energy System Based on a Fuzzy Comprehensive Evaluation Method

Building an integrated energy system (IES) is an excellent solution to environmental pollution and energy consumption currently. However, there are usually various IES configurations with different performances, and it is usually difficult for the decision-makers to select the most sustainable IES solution among multiple choices. In this paper, we attempt to design an evaluation method that considers the renewable energy and energy system model for evaluating the benefit of an IES. Firstly, this paper constructs an evaluation index system including four dimensions of technology, economy, environment, and society, based on the physical architecture of IES and its benefit influencing factors. It focuses on multiple energy sources or systems, and satisfies the overall evaluation of IES, resulting in accurate benefit evaluation results. Secondly, the subjective weight is determined by combining the triangular fuzzy number (TFN) and the analytic hierarchy process (AHP). The objective weight is determined by the entropy method. The combined weight is obtained by combining the subjective and objective weights, which solves the problem of the weight calculation error caused by the mutual influence between the indexes. Finally, the fuzzy comprehensive evaluation method is used to conduct the benefit evaluation of the IES, which solves the problem that the qualitative index cannot be calculated. This paper takes an IES project in a city in northern China as a case study. Through sensitivity analysis and comparative analysis, the reliability and feasibility of the evaluation results and proposed method are verified. The analysis results show that the model evaluation results are intuitive and consistent with reality, and the data information utilization rate is high.

A Study on the Path of Narrative Renewal of Traditional Villages: A Case of Shawan Ancient Town, Guangdong, China.

Traditional villages are a valuable for their historical and cultural heritage, and have long been the focus of academic research regarding their protection and renewal methods in the face of increasing urbanization. In the village renewal model, the continuation and regeneration of cultural context is the core issue. This paper aims to construct the updated narrative text of Shawan Ancient Town on the basis of narrative rules and methods, while also exploring how to generate the conservation and renewal strategies based on the narrative text. Drawing on the concepts and methods of narratology and based on the cultural background and current conditions of Shawan Ancient Town's architectural heritage, this paper takes "narrative in terms of theme, clue, path, and material" as the basic framework to construct the narrative text in the context of traditional village renewal. Then four aspects, such as "base combing, interface integration, patch symbiosis, and debris collection", are used to update the methods of the spatial situation of individual places. Additionally, multiple construction forms are explained, generating a historic, interesting, and experiential strategy for the protection and renewal of ancient towns. This study demonstrates logical thinking from the construction of narrative text to the generation of renewal strategies from a narrative perspective while deepening the typical research on the traditional village narrative renewal mode. It is advantageous to build a protection mechanism for historical and cultural villages, and explore a path to protect, inherit, and promote the cultural heritage of villages based on China's current situation.

A rigorous surface renewal model for transient gas absorption with first-order chemical reaction in a stirred liquid

This work presents a rigorous surface renewal model for unsteady-state gas absorption in a stirred batch cell in which the dissolved gas undergoes a first-order chemical reaction with a liquid-phase reagent for the cases of zero and finite gas-phase mass-transfer resistance, with the concentration of dissolved gas in the bulk liquid being a function of time. For oxygen absorption in water containing a reagent (e.g., sodium sulfite), the model predicts that the rates of absorption and dissolved-gas transfer to the bulk liquid have an inverse behavior during the initial moments of absorption after which they level out as steady state is approached, with the former being higher than the latter due to the consumption of dissolved gas by the reaction occurring in the surface elements. In general, predictions of the dissolved oxygen concentration made with the rigorous model compare quite well with those of a much simpler pseudo steady-state model. However, the rigorous surface renewal model gives a finer grained picture of the phenomenon of absorption, i.e., of the rates of absorption and dissolved-gas transfer, especially during the initial moments of absorption. A hybrid model, which uses both the pseudo steady-state and rigorous surface renewal models, is proposed for performing unsteady-state gas absorption calculations.

Towards sustainable energy technologies at a COVID-19 hospital in Dhaka, Bangladesh

The current energy demands in Bangladesh far supersedes the supply. The thesis provides an efficient way to account for the energy deficit by using a renewable hybrid model design. Solar, Wind, and Biogas were the focus of this thesis for their abundance in the study region. Our thesis explored the possibilities of implementing a hybrid energy system in a makeshift COVID-19 hospital in Purbachal, Bangladesh. The COVID-19 situation is getting worse, even after the first case detected in March 2020.. It is tough to manage sufficient hospital beds with minimum facilities in the least developing country like Bangladesh. The hybrid model developed using HOMER software utilized solar, Wind, and Biogas in a configuration that achieved the best COE and NPC values. The model adjusted parameters such as fuel cost, wind speed, solar radiation, electricity price, and component cost for smooth and realistic simulation. From our simulations, we observed that wind energy was not a feasible option for the region of study, and without Biogas, the PV-Wind or only PV system had a COE of 0.492 and 0.516 USD, respectively. We find good optimize results for PV-Bio as a generator-Battery system. We are getting the COE of around 0.176 USD with a considerable amount of initial capital, 82806.25 USD. Even though the model was primarily fashioned for the healthcare sector in Purbachal, Bangladesh. The model can easily be modified for use in any region of the world and be re-purposed for use in other industries.

The definition of corporate corruption prevention during the last decade: Bibliometrics and content data for the future research agenda

AbstractThe purpose of this research is to provide a valuable study about the development of literature on corruption prevention during the last decade suggesting the way for the future agenda. We collected documents with the aims to develop a structured literature review (SLR). We collected 113 documents adopting a not grey analysis. Our results shows two main research areas: (i) the corruption prevention understanding its features and using accounting and ethical activities in the business and government procurement and (ii) anticorruption measures, disclosure and behaviours as renewed tools to increase corporate governance sustainability and corporate social responsibility. This is the first time for proposing the SLR on corporate corruption preventions and renewed models directed to build an updated background and emerging issues. This paper is original because proposes for the first time the literature collection of corporate corruption prevention's models providing valuable insights, critique and definition for the future research.

머신러닝을 활용한 KBO 외국인 투수 재계약 예측 모형

한국프로야구협회에서는 리그 전력 평준화 및 야구팬들에게 새로운 볼거리 제공을 위해 외국인 선수 제도를 도입하였다. 외국인 투수는 팀의 성적에 영향을 미친다. 일반적으로 외국인 투수의 기록이 좋은 팀은 포스트시즌에 진출하며 그렇지 못한 팀은 하위권에 머무른다. 지난 11년간 재계약 한 선수는 143명 중 49명으로 약 34%의 투수만이 재계약에 성공하였다. 이는 좋은 외국인 투수를 스카우트 하는 것이 쉽지 않음을 보여준다. 즉 구단이 외국인 투수와 재계약을 한다는 것은 성공적인 스카우트였다고 볼 수 있다. 따라서 외국인 투수가 다음 시즌에도 팀과 함께할지를 결정하는 재계약 여부를 영입하기 전에 미리 예측할 수 있다면, 뛰어난 투수를 영입하여 KBO 리그의 수준을 더 높여 야구 팬들에게 수준 높은 경기를 제공할 수 있다. 본 논문은 한국프로야구협회에 등록되었던 외국인 투수의 마이너리그 (트리플A) 성적, 입단 시즌 KBO 성적, 선수들의 얼굴 사진, Strike zone heat map 이미지 등을 독립변수들로 선정하였으며, 이를 토대로 주성분 분석과 머신러닝 알고리즘을 이용하여 KBO 외국인 투수의 재계약 여부를 예측하는 모형을 제안한다.

The impact of diesel operation time constraint on total cost of diesel-based hybrid renewable power system simulation model

This study proposes a simulation model with practical constraints on the use of diesel engine and investigates the impact of adding the constraint of the minimum length of diesel operation time on total cost of hybrid power system, which is designed to supply power for a small village located in the east part of Iran. The results indicated that in the presence of the aforementioned constraint, total cost of hybrid power system increased by shortening diesel generator lifespan and growing diesel fuel consumption. The research did not find any specific uptrend or downtrend in battery lifetime by adding the mentioned constraint into the model. The study outcomes also specified that the surplus power of the hybrid power system inclined in the existence of the minimum length of diesel operation time constraint. The results demonstrated that one hour increment in the minimum length of diesel operation time left a remarkable part of generated renewable power as a surplus power.

General Modelling Method for the Active Distribution Network with Multiple Types of Renewable Distributed Generations

With a proliferation of diverse types of renewable distributed generation (DG) into the distribution network, an equivalent model of an active distribution network (ADN) is extremely important, since the detailed modeling of the whole ADN is much more complex and time consuming. However, different studies developed different model structures of ADNs, which are difficult to be applied in a power system simulation. At the same time, the DG’s low voltage ride through the (LVRT) control was not considered in the existing ADN model, which may lead to a large modelling error. In this paper, a general equivalent model is developed for the ADN with a significant amount of DGs, based on a two-step modelling method. Step one, motivated by the dynamic similarities between the doubly-fed induction generator (DFIG)-based wind turbines, direct drive permanent magnet synchronous generator (DDPMSG)-based wind turbines, and photovoltaic (PV) generation, a general model structure of a renewable DG is initially developed. Then, an aggregation method for the DG’s nonlinear subsystems of the low voltage ride through (LVRT) control and the converter’s current limits are presented. Step two, the ADN model is represented by a general renewable DG model paralleled with a composite load model, and the model is validated, based on an actual distribution network with different renewable DG penetrations and different disturbance degrees. The simulation results show that our model outperforms others with acceptable errors.

From Galactic chemical evolution to cosmic supernova rates synchronized with core-collapse supernovae limited to the narrow progenitor mass range

ABSTRACT Massive (≥8 M⊙) stars perish via one of two fates: core-collapse supernovae (CCSNe), which release synthesized heavy elements, or failed supernovae, thereby forming black holes. In the conventional Galactic chemical evolution (GCE) scheme, a substantial portion of massive stars, e.g. all stars in the mass range of 8–100 M⊙, are assumed to enrich the Galaxy with their nucleosynthetic products. However, this hypothesis conflicts with the observations, namely, few CCSNe whose progenitor stars are more massive than ∼18 M⊙. Here, we show that the chemical characteristics shaped by local thin disc stars are compatible with the predictions by enrichment via CCSNe limited to less massive progenitors in the new paradigm of Galactic dynamics that allows stars to migrate from the inner disc. This renewed GCE model predicts that the bursting star formation events − which are considered to take place in the Galactic bulge and in the thick disc − generate more numerous low-mass CCSNe than those expected from the locally determined canonical initial mass function. This finding suggests a high rate of CCSNe in early-type galaxies, which reflects a unique cosmic history of the CCSN rate. With considerable contributions from these galaxies to the cosmic star formation rates in the early Universe, we predict a more steeply increasing slope of the CCSN rate with increasing redshift than that in proportion to cosmic star formation. This predicted redshift evolution agrees well with the measured rates for $0 \lesssim z \lesssim 0.8$; however, its predicted CCSN rate for higher z calls for more precise data from future surveys.

Design, development, and techno-economic analysis of extreme fast charging topologies using Super Capacitor and Li-Ion Battery combinations

In the past few decades, it has been observed that Renewable Energy System (RES) coupled with a grid is a potential option for fulfilling the fast-growing load demand. However, the intermittent nature of renewable energy resources limits the performance of RES and prevents it from being properly utilized. This results in power quality issues and grid system instability. To address this issue, it is a common practice to combine RES with effective energy storage technologies, including the latest storage system based on Lithium-Ion Batteries (LIB) and Super Capacitors (SC). However, the fast charging of LIB and slow discharging of SC are still debatable. Time taken for charging LIB is usually sky-high that the Cost of Energy (CoE) becomes unprofitable. On the other side, although the charging of SC is faster, but undergoes quick discharging. Hence, in this paper, a cutting-edge model of LIB, i.e., an extreme Fast Charging LIB (FCLIB) is developed, where LIB is integrated with fast charging SC. This reduces the charging time of storage systems in comparison with conventional systems. In the current paper, six alternative topologies of FCLIB are developed and analyzed for CoE estimation, using real commercial load profiles and resource data. It is observed that the proposed FCLIB with the best topology is achieving 80 % of its State of Charge (SoC) in 5.84 min and 100 % of SoC in 13.5 min. The Optimized Electric Renewable Model (OERM) was employed to analyze the techno-economic analysis of the proposed FCLIB. It is estimated that the proposed topology of FCLIB has a CoE of 0.32$/kWh with fast charging, which is approximately equal to the CoE of a conventional slow charging LIB (estimated as 0.33$/kWh). Thus, the designed FCLIB provides an optimal storage solution for RES to overcome the intermittent nature of renewable energy resources to meet the load demand.