scholarly journals Region-wide comprehensive implementation of roguing infected trees, tree replacement, and insecticide applications successfully controls citrus HLB

2020 ◽  
Author(s):  
Xiaoyong Yuan ◽  
Cixiang Chen ◽  
Renato Bassanezi ◽  
Feng Wu ◽  
Zheng Feng ◽  
...  
Keyword(s):  
Regression Model ◽  
Large Scale ◽  
Regional Level ◽  
Economic Feasibility ◽  
Small Scale ◽  
Comprehensive Strategy ◽  
Endemic Diseases ◽  
Dynamic Regression Model ◽  
Partial Implementation ◽  
Citrus Disease

Huanglongbing (HLB) is a devastating citrus disease worldwide. A three-pronged approach to controlling HLB has been suggested, namely, removal of HLB-symptomatic trees, psyllid control, and replacement with HLB-free trees. However, such a strategy did not lead to successful HLB control in many citrus producing regions. We hypothesize this is because of the small-scale or incomprehensive implementation of the program, conversely, a comprehensive implementation of such a strategy at regional level can successfully control HLB. Here we investigated the effects of region-wide comprehensive implementation of this scheme to control HLB in Gannan region, China, with a total planted citrus acreage of over 110,000 ha from 2013–2019. With the region-wide implementation of comprehensive HLB management, overall HLB incidence in Gannan decreased from 19.71% in 2014 to 3.86% in 2019. A partial implementation of such a program (without a comprehensive inoculum removal) at the regional level in Brazil resulted in HLB incidence increasing from 1.89% in 2010 to 19.02% in 2019. A dynamic regression model analyses predicated that in a region-wide comprehensive implementation of such a program, HLB incidence would be controlled to a level of less than 1%. Economic feasibility analyses showed that average net profits were positive for groves that implemented the comprehensive strategy, but negative for groves without such a program over a ten-year period. Overall, the key for the three-pronged program to successfully control HLB control is the large scale (region-wide) and comprehensiveness in implementation. This study provides valuable information to control HLB and other endemic diseases worldwide.

scholarly journals Governance and enterprise restructuring: the case of Macedonia

2014 ◽  
Vol 9 (1) ◽  
pp. 147-156 ◽  
Author(s):  
Mico Apostolov
Keyword(s):  
Corporate Governance ◽  
Regression Model ◽  
Financial Institutions ◽  
Large Scale ◽  
Transition Economy ◽  
Small Scale ◽  
Institution Building ◽  
Content Type ◽  
Enterprise Restructuring ◽  
The Republic

Purpose – This paper is a case study of the Republic of Macedonia and focuses on the development of governance and enterprise restructuring. Thus, country's effective corporate governance and corporate control, which impact enterprise restructuring, are essential in the analysis of market-driven restructuring through domestic financial institutions and markets. The data used in this article are analyzed with an econometric regression model, which as employed in this study examines the interrelationships between governance and enterprise restructuring and set of policies that influence the governance patterns. Two basic hypothesis are taken in the analysis: first, governance and enterprise restructuring depend on set of policies, such as, large-scale privatization, small-scale privatization, price liberalization, competition policy, trade and foreign exchange system, banking reform and interest rate liberalization, securities markets and non-bank financial institutions and overall infrastructure reform; and second, governance and enterprise restructuring improves over time due to imposed policies. The paper aims to discuss these issues. Design/methodology/approach – The data used in this article are analyzed with an econometric regression model, which as employed in this study examines the interrelationships between governance and enterprise restructuring and set of policies that influence the governance patterns. Findings – There is still more to be done in order to bring these economies closer to the standards of developed ones. Indeed, it is needed considerable improvement of corporate governance, institution-building to control agency problems and imposing already adopted regulation, as well as, enforcing new enterprise restructuring policies, within existing policies of overall transition economy restructuring. Originality/value – This paper is a contribution to the research developing the business aspects of the Macedonian economy, as there is constant lack of scientific papers that deal with the specific issues of corporate governance and enterprise restructuring.

scholarly journals An adaptive two-stage analog/regression model for probabilistic prediction of small-scale precipitation in France

2018 ◽  
Vol 22 (1) ◽  
pp. 265-286 ◽  
Author(s):  
Jérémy Chardon ◽  
Benoit Hingray ◽  
Anne-Catherine Favre
Keyword(s):  
Regression Model ◽  
Large Scale ◽  
Linear Models ◽  
Transfer Functions ◽  
Small Scale ◽  
Probabilistic Prediction ◽  
Two Stage ◽  
Precipitation Occurrence ◽  
Seasonal Stratification ◽  
Local Weather

Abstract. Statistical downscaling models (SDMs) are often used to produce local weather scenarios from large-scale atmospheric information. SDMs include transfer functions which are based on a statistical link identified from observations between local weather and a set of large-scale predictors. As physical processes driving surface weather vary in time, the most relevant predictors and the regression link are likely to vary in time too. This is well known for precipitation for instance and the link is thus often estimated after some seasonal stratification of the data. In this study, we present a two-stage analog/regression model where the regression link is estimated from atmospheric analogs of the current prediction day. Atmospheric analogs are identified from fields of geopotential heights at 1000 and 500 hPa. For the regression stage, two generalized linear models are further used to model the probability of precipitation occurrence and the distribution of non-zero precipitation amounts, respectively. The two-stage model is evaluated for the probabilistic prediction of small-scale precipitation over France. It noticeably improves the skill of the prediction for both precipitation occurrence and amount. As the analog days vary from one prediction day to another, the atmospheric predictors selected in the regression stage and the value of the corresponding regression coefficients can vary from one prediction day to another. The model allows thus for a day-to-day adaptive and tailored downscaling. It can also reveal specific predictors for peculiar and non-frequent weather configurations.

scholarly journals Geo-Spatially Based Analysis And Economic Feasiblity Evaluation Of Waste-To-Energy Facilities: A Case Study Of Local Government Areas Of Anambra State Of Nigeria

2021 ◽  
Author(s):  
Emmanuel Chukwuma ◽  
John Ojediran ◽  
Daniel Azikiwe Anizoba ◽  
Joseph Azikiwe Ubah ◽  
Pius Nwachukwu
Keyword(s):  
Local Government ◽  
Large Scale ◽  
Clean Energy ◽  
Economic Feasibility ◽  
Waste To Energy ◽  
Small Scale ◽  
Optimum Number ◽  
Organic Fraction ◽  
Anambra State

Abstract Access to affordable clean energy source as stipulated in UN SDG goal number 7 is important for the development and socio-economic well-being of people, the need for proper assessment of resources to achieve this goal is indisputable. The goal of this study is to assess the economic feasibility of utilizing organic fraction of Municipal Solid Wastes (MSWof) using a case study of 21 Local Government Areas (LGA) or Authority for Anambra State of Nigeria for waste to energy project. The quantity of organic fraction of MSW, energy recovery and optimum number of plants at the various LGAs was estimated. The result of the study indicates that about 198 tons maximum value of MSWof can be generated daily in Aguata LGA, with electric energy potential value of 545MW. The number of plants for the LGAs ranged from 10 to 50 and from 3 to 12 for small and medium scale plants. A large scale plant of about 50m3 can possibly be installed at all the LGAs, with a maximum of 4 plants in Idemili and Aguata LGA. The economic assessment based on Net Present Value (NPV) criteria shows poor economic feasibility for small scale plant, while NPV was positive for medium and large scale plants. The Internal Rate of Return (IRR) ranged from 0.32 to 0.94, with a general increase from small scale to large scale economic feasibility. It is suggested that the autonomy of the various LGAs in the country should serve as a major motivation in adopting bio-energy projects independently, and this study will serve as a decision toolkit in the appropriate scale to be adopted.

A techno-economic feasibility assessment on small-scale forest biomass gasification at a regional level

2014 ◽  
Vol 8 ◽  
pp. 6565-6576 ◽  
Author(s):  
Daniele Dell’Antonia ◽  
Sirio R. S. Cividino ◽  
Olga Malev ◽  
Gianfranco Pergher ◽  
Rino Gubiani
Keyword(s):  
Forest Biomass ◽  
Biomass Gasification ◽  
Regional Level ◽  
Economic Feasibility ◽  
Small Scale ◽  
Feasibility Assessment

ECONOMIC FEASIBILITY OF TWO TECHNOLOGIES FOR PRODUCTION OF A MYCOPESTICIDE IN MADAGASCAR

1997 ◽  
Vol 129 (S171) ◽  
pp. 101-113 ◽  
Author(s):  
Dan Swanson
Keyword(s):  
Large Scale ◽  
Net Present Value ◽  
Capital Budgeting ◽  
Cash Flows ◽  
Economic Feasibility ◽  
Small Scale ◽  
Scale Production ◽  
Production Models ◽  
Investment Capital ◽  
Capital Intensive

AbstractThe net present value (NPV) approach to capital budgeting is used to determine the relative economic feasibility of two production models capable of manufacturing a fungi-based biopesticide in Madagascar. Sales revenues are projected at $10–12 per hectare for 20 000–80 000 ha annually, with recurrent costs estimated in Madagascar and investment costs from IITA (Cotonou, Benin) and Mycotech Corporation (Butte, Montana). These cash flows are discounted by an appropriate interest rate and risk factor, with positive results for both the labour-intensive model and the capital-intensive model under several scenarios. Cost advantages for the two models depend on both technology and scale. The labour-intensive model achieves a higher NPV in a market of 20 000 ha per annum as compared with the capital-intensive model. The capital-intensive model achieves a higher NPV in a market of 80 000 ha (including exports to southern Africa). Both models benefit from scale economies, although this benefit is relatively greater for the capital-intensive model. Consumers of mycopesticides in Madagascar could realize nearly 20% savings under a higher output scenario with a capital-intensive technology, than under a lower output scenario with a labour-intensive technology. Large-scale producers, however, would require nearly four times as much investment capital, and could find it difficult to produce for export from Madagascar. In the absence of a large-scale producer, small-scale production would be appropriate and feasible based on lower investment costs. Malagasy production is also protected from foreign competition because of current phytosanitary regulations.

A NEW VIEWPOINT OF S-CURVE REGRESSION MODEL AND ITS APPLICATION TO CONSTRUCTION MANAGEMENT

2006 ◽  
Vol 15 (02) ◽  
pp. 131-142 ◽  
Author(s):  
TING-YA HSIEH ◽  
MORRIS H. L. WANG ◽  
CHENG-WU CHEN ◽  
CHEN-YUAN CHEN ◽  
SHANG-EN YU ◽  
...  
Keyword(s):  
Regression Model ◽  
Large Scale ◽  
Fuzzy Model ◽  
Least Square Method ◽  
Least Square ◽  
City Government ◽  
Fuzzy Regression ◽  
Small Scale ◽  
Project Control ◽  
S Curve

The least square method is in generally used for curve fitting problems. We here propose a fuzzy S-curve regression model to deal with the case in which the observed data are given by fuzzy numbers. The fuzzy regression curve, obtained for project control and predicting the progress of large-scale or small-scale engineering, is smoothly connected by a Takagi-Sugeno (T-S) fuzzy model. This paper also proposes the concept that the upper bound and lower bound are given instead of the confidence interval when the observed data are not obtained exactly. Based on the project cash flow and progress payment records of an example project taken from the Department of Rapid Transit Systems, Taipei City Government, this model is demonstrated and tentative conclusions concerning the model are given. The S-curve equation developed here could be used in a variety of applications related to project control for the management of working capital for construction firms.

scholarly journals Selection of a chipper technology for small-scale operations – a Finnish case

2019 ◽  
Vol 65 (No. 4) ◽  
pp. 121-133 ◽  
Author(s):  
Juha Laitila ◽  
Robert Prinz ◽  
Lauri Sikanen
Keyword(s):  
Large Scale ◽  
Net Present Value ◽  
Unit Cost ◽  
Economic Feasibility ◽  
Operating Costs ◽  
Small Scale ◽  
Technical Details ◽  
The Cost ◽  
Cost Factors ◽  
Selection Of

The objective of this study was to determine the economic performance of alternative chipper choices for small-scale chipping based on unit cost (€ per chip-m3) and net present value (NPV) calculations. For the chipping cost and investment profitability analyses four tractor-powered professional or semi-professional disc chippers and two professional drum chippers mounted on a truck or powered by tractor were selected. Initial investment, operating costs, and the cost of outsourced chipping were the key elements for comparing the profitability of investment alternatives. The average purchase prices, cost factors, and technical details of the chipper units were acquired from machine dealers, specification sheets, a literature review, and interviews with chipping entrepreneurs. The results of the three tractor-powered professional chippers involved in the comparison were very close to each other. The profitable running of a truck-mounted drum chipper calls for high annual chipping volumes: the chipper type is therefore a feasible choice for an entrepreneur in large-scale chipping. Semi-professional disc chippers offer lower investment costs, but their economic feasibility is relatively poor.

Performance Analysis and Modeling of Different Volumetric Expanders for Small-Scale Organic Rankine Cycles

2011 ◽  
Author(s):  
Stefano Clemente ◽  
Diego Micheli ◽  
Mauro Reini ◽  
Rodolfo Taccani
Keyword(s):  
Energy Recovery ◽  
Large Scale ◽  
High Efficiency ◽  
Waste Heat ◽  
Low Cost ◽  
Economic Feasibility ◽  
Small Scale ◽  
Main Research ◽  
Energy Field ◽  
Organic Rankine Cycles

In the last years one of the main research topics in energy field is represented by Organic Rankine Cycles (ORCs), due to their applicability in energy recovery from waste heat and in distributed combined heat and power (CHP) generation, particularly in small and micro scale systems. One of the key devices of the cycle is the expander: it must have a limited cost (like all the other components, in order to ensure the economic feasibility), but also a high efficiency, since the temperature of the heat source is often low and then the cycle efficiency is inherently scarce. In the first part of this paper a literature review on various positive-displacement expanders is presented, in order to outline their performances and their application field. Then, the numerical model of a volumetric reciprocating expander is implemented. This model, and another one previously developed to simulate scroll expanders, is combined with a thermodynamic model of the whole ORC system, so that a comparison between the two technologies can be carried out. The results confirm the possibility of realizing small scale energy recovery and cogeneration (CHP) systems with acceptable electrical efficiency also adopting low-cost components, directly derived from large scale industrial components.

scholarly journals Socio-Economic Impact Research of Foundry Industry By using Neural Network

2019 ◽  
Vol 8 (11S) ◽  
pp. 401-404
Keyword(s):  
Neural Network ◽  
Regression Model ◽  
Large Scale ◽  
Small Scale ◽  
Total Production ◽  
Environmental Aspect ◽  
Foundry Industry ◽  
Socio Economic Impact ◽  
Casting Production ◽  
Critical Aspects

Global casting production reached 104.4 million tons in 2016. The top ten casting production nation produces 91.6 million metric tons of the total production of 104.4 million metric tons. Nearly 47.2 million metric tons of casting produces by China. Casting production increases from 5.4% to 11.35% million metric tons. USA, Japan, Germany, Russia, Korea, Mexico, Brazil and Italy are the top ten nations. Almost 6500 foundry units are in country out of which 90% can be categorized as small scale units, medium scale units as 8% and large scale units as 2%. Foundry industry includes several critical aspects related to social, economic and environmental aspect need to assess. The results gained by these models are compared with regression model. Socio- economic foundry industry complex relationship between different parameters can be modeled by using neural network and regression model. It can also study running such program lead to substantial improvements in socioeconomic circumstances of targeted industry and make it sustainable industry.

PERFORMANCE OF IRRIGATION: AN ASSESSMENT AT DIFFERENT SCALES IN ETHIOPIA

2011 ◽  
Vol 47 (S1) ◽  
pp. 57-69 ◽  
Author(s):  
SELESHI BEKELE AWULACHEW ◽  
MEKONNEN AYANA
Keyword(s):  
Performance Indicators ◽  
Large Scale ◽  
Relative Proportion ◽  
National Level ◽  
Regional Level ◽  
Irrigated Agriculture ◽  
Small Scale ◽  
Command Area ◽  
Water Control ◽  
Output Performance

SUMMARYEthiopia has an irrigation potential of 5.3 million ha (Mha) of which 3.7 Mha can be developed using surface water sources, and 1.6 Mha using groundwater and rainwater management. Irrigation contributes to rapid transformation of agriculture as present-day agriculture is dominated by rainfed single crops. The current irrigation development in Ethiopia is about 0.7 Mha, and the performance of the existing schemes is not well understood. As the country is planning to expand irrigated agriculture in the next five years, it will be useful to review existing performance and to identify areas for interventions that help revitalize underperforming systems. In this paper, we have investigated the performances of irrigation at three levels: (a) national level for broad performance, (b) regional level for small-scale irrigation and (c) scheme level for large-scale irrigation. National level indicators measure (i) the relative proportion of operating schemes, (ii) ratio of actually cultivated area to planned command area and (iii) relative number of benefited to targeted number of households. The result shows that 86.5% of schemes are operating, 74.1% of command area is under cultivation and only 46.8% of the planned beneficiaries have benefited from implemented irrigation. For regional level irrigation performances, the regions of Southern Nations and Nationalities and Oromia Regions were investigated. We used technological (structural) and management factors as measures of performances. Sixty-four underperforming schemes were sampled from the two regions to analyse the causes. About 30 parameters were identified as causes of underperformance. Watershed degradation related problems that are causing erosion and sedimentation of water control and conveyance structures are found to be the major cause for structural failures, while lack of sustainable funding, extension of agronomic practice, and post harvest technologies are identified as the top management-related problems. For evaluating performances of large-scale schemes, we used irrigation water delivery performance and output performance indicators applied to six large-scale schemes. Scheme level performance indicators results showed that all of the schemes considered have supplied adequate to excess amounts of water during the period. The Wonji scheme that uses pump diversion showed higher water use efficiency than other schemes that are using simple gravity diversion types. In this case it might be the running costs of pumps that have encouraged efficient management of water. In terms of output performance, sugarcane based irrigation schemes are superior and up to ten times that of banana, cotton, and maize or tobacco production. The results of these assessments are useful for decision-makers and disclosed the low performance of the existing irrigation schemes. They also indicated the need to revitalize existing schemes to improve performance in parallel to the implementation of new projects. The paper also provided new indicators of evaluation of performance with respect to national level, structural and management related performance.

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