Offer And Demand Research Articles

Integrated optimal scheduling of repair crew and relief vehicle after disaster

When catastrophes occur, certain areas could be isolated and have more hardship in being provided with the relief goods because of the destruction of roads. Additional damages will occur if isolated areas cannot be supplied relief goods quickly. Therefore, to provide adequate relief goods to the demand area in time, it is essential to recover the destroyed roads and make the isolated areas accessible. In addition, relief goods should be distributed on the basis of optimal scheduling. If the order for repairing destroyed roads and supplying relief goods to an isolated area is established from the respective viewpoints, a delay will occur compared to optimal schedule considering both of them simultaneously. Thus, this study proposes a mathematical model based on Mixed Integer Linear Programming (MILP) and an Ant Colony Optimization (ACO) algorithm providing optimal scheduling by taking into account both reconstruction and delivery. By conducting various numerical experiments, the solution from the MILP and ACO could lead to more effective results than decisions based on two points of view that are not synchronized. Some meaningful findings are also found by numerous computational experiments. This research can help to make the optimal decision for scheduling of recovery and supply that thus reduces any additional damage after a major disaster.

Collection, Consumption, and Sale of Lusala (Dioscorea hirtiflora)\u2014a Wild Yam\u2014by Rural Households in Southern Province, Zambia

Dioscorea hirtiflora Benth. is an indigenous wild edible tuberous climbing plant native to Zambia. Known as lusala, the tubers are sold in markets across southern Zambia. Lusala collection, consumption, and trade were investigated through interviews with rural households (four districts) and market traders (three towns), and supplementary focus group discussions. Of 278 households interviewed, high proportions collected (83%), consumed (96%), and sold (59%) lusala, not varying amongst district or wealth category. Lusala populations were perceived to be declining in the wild by 79% of households. Tuber collection, largely by females and mainly from March to September, peaked in April when households engaged in each activity and collected 27.9 kg, consumed 12.0 kg, and sold 35.7 kg (from 129, 108, and 69 reporting households, respectively) that month, regardless of district, wealth category, or gender. Those sales provided an average household income of USD 16 in April 2017. In August 2017, each market trader purchased an average of 899 kg for USD 383. Local knowledge of D. hirtiflora was considerable. Lusala collected from forests is an important edible wild tuber in the local economy of the Southern Province of Zambia; it provides a seasonally important food supply and income to rural households and supplies demand for urban populations.

Independent bodies specialized in ensuring the principle of participation in the federal system Study under the permanent Iraqi constitution for 2005

The Constitution of Iraq in 2005 has restructured the Iraqi state in accordance with two main and interrelated demands for the Iraqis, namely the democratization and federalism of the Iraqi state. The constitutional legislator resorted to many principles, institutions and procedures to achieve the two previous demands. Among these institutions that the Constitution required to be established are the Independent Commissions, Some of These Independent commissions related to technical issues and others concerned with the democratization of the state. Two of them were dedicated to the new federalism of Iraq, by ensuring the realization and application of one of the main principles of the federal state which is the principle of participation, these two Independent Commissions are (The Public Commission of Guarantee the rights of regions and governorates that are not organized in the region) which provided for in Article (105) of the Constitution and (The Public Commission of auditing and appropriation of federal revenues) which provided for in Article (106) of the Constitution. This study will examine these two Commissions and deal with them in all their aspects in light of both the Iraqi Constitution and the laws governing them, and marking down our observations on the law and propose what we consider necessary amendments for the purpose of development, due to their importance for the new phase of the Iraqi state

Bayesian regularized NAR neural network based short-term prediction method of water consumption

With the continuous construction of urban water supply infrastructure, it is extremely urgent to change the management mode of water supply from traditional manual experience to modern and efficient means. The water consumption forecast is the premise of water supply scheduling, and its accuracy also directly affects the effectiveness of water supply scheduling. This paper analyzes the regularity of water consumption time series, establishes a short-term water consumption prediction model based on Bayesian regularized NAR neural network, and compares and evaluates the prediction effect of the model. The verification results show that the Bayesian based NAR neural network prediction model has higher adaptability to the water consumption prediction than the standard BP neural network and the Bayesian regularized BP neural network. The prediction accuracy can more accurately reflect the short-term variation of water consumption.

The specificity of the antihypertensive action of the renin-angiotensin system inhibitors

Objective: the determination of the presence and character of action of the agents suppressing the renin-angiotensin system activity, their ability not only induce antihypertensive effect but also influence on the atherogenic blood potential and vascular remodeling in patients with arterial hypertension.Material and methods. 97 patients with stage 1 and 2 arterial hypertension were enrolled in the investigation. All patients were divided into 3 groups: 1) persons who were treated with receptor angiotensin II blockers 2) patients who were treated with ACE inhibitors (50 persons) 3) (control, 20 persons) patients who were treated with calcium channel blockers. All patients additionally received hydrochlorothiazide. The duration of the investigation was 1+0,1 year. There were measured the levels of SAP, DAP and pulse pressure. There was also determined the blood content of glucose, cholesterol, triglyceride, cholesterol of high-density lipoproteins with the use of analyzer BioSystems A‑25 (Spain). Level of low and very low density lipoprotein cholesterol was calculated according to the Freedwald formula. The echocardiographic investigation was carried out in M and B regimes according to the standard protocol. The cardiac activity, double product, total peripheral vascular resistance were calculated. The obtained data were analyzed statistically with the application of the program Excel 2003. The changes were considered as significant in р<0,05. Results. The development of arterial hypertension was the result of functional and structural remodeling of the arterial vessels wall with an increase of total vascular resistance on the background of unchanged central hemodynamics in conjunction with the increase of cardiac activity and its demand in blood supply, which meant the decrease of the economy of heart activity. In parallel rose the blood atherogenic potential with increasing of the blood content of low and very low-density lipoprotein cholesterol, decreasing of high-density lipoprotein cholesterol and growth of atherogenic index. Application of calcium channel blockers with diuretics had pronounced antihypertensive effect but nevertheless, SAP pulse pressure and the level of total vascular resistance remained higher in comparison with normal values. That pointed only to the partial elimination of vascular remodelling. There was not also marked the influence on increased atherogenic potential. On the contrary, the application of renin-angiotensin system inhibitors led to the achievement of the target level of AP with a primary decrease of SAP and pulse pressure in conjunction with almost complete normalization of vascular resistance that witnessed about the pronounced regression of vascular remodeling. As a result, there was marked the significant decrease of the heart work and his blood supply demand, which pointed to the optimization of heart activity. There was also marked the significant decrease in blood atherogenic potential. Conclusions. The data proves the significant priority of the antihypertensive therapy with application of renin-angiotensin system inhibitors. That was proved by more pronounced AP normalization, more pronounced regression of the vascular remodelling, significant decrease of blood atherogenic potential and lowering as a result the risk of ischemic heart disease development.

Novel control strategy of grid‐connected photovoltaic power supply for frequency regulation

The maximum power point tracking (MPPT) mode is widely applied in photovoltaic (PV) power generation system. In this article, instead of MPPT, a novel control strategy of grid-connected PV power supply for frequency regulation is proposed. First, the static frequency characteristic curve of PV plant is proposed, and a method of synthesising the PV power output power–voltage characteristic curve and static frequency characteristic curve into frequency regulation curve of PV power supply is introduced. So the PV plant can participate in frequency regulation of the system. Through simulation analysis in power systems computer aided design (PSCAD)/electromagnetic transients including DC (EMTDC), PV plant realises the function of frequency regulation when load changes, so the variation of system frequency can be reduced and the frequency stability of power system can be improved, and the effectiveness of the strategy is verified.

Stranded wealth: rethinking the politics of oil in an age of abundance

This article argues that the oil industry is unlikely to return to the pre-2014 status quo as two profound shifts in technology and markets are dramatically changing the longer-term outlook for the oil industry. In the short term, traditional producers will feel persistent pressure from the shale revolution, a disruptive technology that has altered the cost curve and elasticity of oil supply. In the medium term, the industry must confront a structural slowdown and eventual peak in demand owing to innovation and evolving consumer preferences, related in part to concerns over climate change. Together, these shifts reflect a new energy order in which oil is no longer an exhaustible resource, new trading patterns emerge and oil prices exhibit greater short-term volatility amid a long-term declining trend. These new rules of the game force us to reconsider some of the theories and concepts of the international political economy of oil. We flag three key political effects from these market shifts: first, key oil-producing states face economic and political turmoil; second, OPEC cannot influence the price of oil in the long term by cutting output; and third, power is redistributed in the international system.

PRINCIPLES OF MODELING OF THE GENERAL ECONOMIC EQUILIBRIUM

This paper focuses on formulation of the principles of macroeconomic modeling and their implementation in the theory of general dynamic equilibrium. The subject of the theoretical study is a closed private economy, in which two macroeconomic actors – households and investment firms – interact. Known general scientific principles – the analysis of dimensions, homogeneity and correspondence – are supplemented by specific principles that allow us to obtain an analytical form of behavioral functions. The general properties of these functions are analyzed from the point of view of utility theory. The relationship between the equations of profit and profitability dynamics and the forms of investment function is revealed. A comparative analysis of their properties is carried out. The functions of rates of payment for resources, which take into account their limitations, are proposed. It is shown that endogenous cyclic fluctuations arise in the classical AD – AS model, supplemented by equations of the dynamics of fixed capital and profitability. A mathematical analysis of the proposed model is carried out and its graphical interpretation is given using long-run curves of aggregate demand and aggregate supply. Indicators of the state of long-run equilibrium and the condition of its stability are determined.The possible directions of the proposed model are considered. In particular, it is shown that this model can include a financial market in which households and investment firms directly lend money to each other. This market can be represented using two symmetric demand-supply functions that link the interest rate, present and expected future cash reserves.

Elasticities, Tax Rates and Industry Opposition to Unilateral Carbon Pricing: Evidence from Agriculture

Environmental regulation can interact with agricultural markets to produce underappreciated competitiveness and leakage effects. This paper measures effective carbon tax stringency by structurally recovering the domestic supply schedule for a trade-exposed beef cattle industry such that elasticities and carbon tax rates change with product prices (i.e., due to the curvature of the supply function). Two basic propositions from the economics of taxation -- that excess burdens increase in elasticities and tax rates -- are shown to cause the stringency of uniform carbon policy to vary nonlinearly with output prices. Based on the domestic supply function, the relationship between marginal excess burden, a measure of policy stringency from the industry's perspective, and product prices is estimated. Several policy-relevant counterfactual scenarios are explored. Results show that with moderately high output prices, supply elasticities are small and the efficiency cost of a $40/tCO2e carbon tax (gross of environmental benefits) is less than $0.01 per dollar tax revenue. As prices decline, supply curves become increasingly elastic and marginal excess burdens grow rapidly.

Can cryptocurrencies fulfil the functions of money?

This paper analyses the monetary characteristics of five cryptocurrencies to evaluate whether they can perform the functions of money. While all cryptocurrencies can theoretically and practically serve as a medium of exchange, they are unlikely to become common and liquid media of exchange unless they can illustrate utility in one of the other functions of money. Digital currencies’ rigidly inflexible supply and wildly fluctuating demand make them too unstable to be used as a unit of account for the foreseeable future. Of the five, only Bitcoin has the potential to serve as a store of value, due to its strict commitment to low supply growth, credibly backed by the network’s distributed protocol and credible demonstration of the absence of any authority capable of altering the supply schedule. Other cryptocurrencies’ centralized control, and use as tokens for specific applications make them unlikely to fulfil monetary functions.

On the Relevance of Implementation of the Automated System of Production and Supply Sheduling at Oil Refinery

The article discusses the relevance of implementing scheduling system for the purposes of production and supply scheduling at refineries. For this objective, we identified the main factors that affect the complexity of the task of scheduling and reduce the accuracy of the developed schedules, and proposed a practical approach to assessing the influence of these factors in order to analyze the relevance of the implementation of scheduling system. The article also considers the issues of economic efficiency derived from the implementation of scheduling system.

The concept of “Grass-based Livestock Husbandry” and its practice in Hulun Buir, Inner Mongolia

Grassland is the largest area of territorial ecosystems in China, and accounts for more than 30% of the total national land area. Primarily located in the north part and as the homeland of most ethnic minorities, the grassland region is critical for ecological safety and the national security of the country. Furthermore, grassland provides nearly one-third of the country total red meat and dairy products, respectively, and is important for national healthy food supply. Yet, it is believed that a large proportion of China’s grasslands has been degraded or desertified at various degrees because of overgrazing, increased population, mining, farming activities, and climate change. To achieve grassland sustainable development, new concepts and technological advancement are required to tackle the degradation challenges and to balance the relationships between “ecological civilization, sustainable production and better living standard”. For this purpose, we proposed the concept of “Grass-based Livestock Husbandry” (abbreviated as GLiH concept), which defines ecologically-sound management of grass-fed livestock and includes three production systems: forage cultivation, forage processing, and livestock management and processing. This paper documents contents and significance of the GLiH concept, and discusses key scientific and technical issues in the development of grass-based livestock husbandry and their possible solutions. The key of the concept is the coupling and coherent development of an inter-dependent “grass-livestock relationship”. In the GLiH concept, “grasses” (including various perennial and annual grass and shrub species) are considered as the foundation of “livestock” and provides an explanation for the long-standing frustration in China’s livestock farming industry, in which for years forage production has been totally neglected. GLiH also emphasizes the dual (productional and ecological) function of the grassland and proposes to manage the grassland regions according to the “small vs. big” theory, i.e., to allocate a small area of resources-rich land for cultivation of forage crops with high biomass and high quality to protect the vast but fragile grasslands away from over-grazing and over-exploitation, as such to secure the demand of the animal feed supplies as well as to allow the grassland to make its ecological functioning. We also propose eight principles for the development of grass-based livestock husbandry, including grass breeding, artificial grassland farming, conservation and better use of natural grassland, rational allocation between grass production and ecological functioning, efficient harvesting and processing, efficient feeding of livestock, efficient use of natural resources, and systems development. To verify the GLiH concept, a large scale pilot project of “Development of Experimental Zone for Sustainable Management of Grass-based Livestock Systems” has been implemented, in collaboration with Hulun Buir State Farm Conglomerate, and the project has achieved a big success ecologically and economically.

Assessment of empirical and regression methods for infilling missing streamflow data in Little Ruaha catchment Tanzania

Water resources and engineering projects are of major importance due to great demand of water and power supplies, irrigation needs, drought mitigation and flood control. In order to plan and design these projects, complete and reliable hydrological datasets are required. Missing data can severely compromise data quality and utility. The Rufiji Water Basin Office has developed and kept a database of daily streamflow records from 1950s to-date for at least 87 gauging stations. While the majority of the records are complete, data checks revealed significant gaps. Some stations are experiencing large gaps of up to 19 consecutive years. There is no dedicated study that looked at assessment of suitable methods for infilling such gaps.This study therefore made a contribution by appraising empirical and regression rainfall runoff based methods in the Little Ruaha River catchment, a sub-catchment of the Great Ruaha River sub-basin both within the Rufiji River Basin. The methods employed included simple linear regression (with untransformed and log-transformed data), multiple linear regression (with untransformed and log-transformed data), rainfall-runoff relationship using double mass curve technique, flow duration matching and drainage-area ratio. In addition, rainfall runoff modeling using HBV-Light was done for further comparison. With exception to the rainfall-runoff relationship and HBV-Light model, all other methods relied upon data transfer from donor stations (upstream & downstream station(s)) for infilling a downstream/upstream station. Data quality and consistency checks were performed, and performances of infilling methods were evaluated based on three performance criteria namely Nash-Sutcliffe efficiency coefficient (NSE), Coefficient of determination (R2) and standard error of estimate (SE) during calibration and validation periods. Four gauging stations (2 each upstream and downstream) were separately used to infill artificially created gaps to the target station. Overall, the calibration and validation daily results at 1KA21A indicated that the flow duration matching technique and multiple linear regression methods performed better than other methods with NSE (71%; 93%) and NSE (55%; 75%) respectively. These results have a potential for wide application in other basins of Tanzania for hydrological analysis and water resource management, where missing data is very common.

PCN129 - Cost-Effectiveness of Short-Course Radiotherapy Compared to Long-Course Chemoradiotherapy in the Treatment of Stage Iii Rectal Cancer Patients from the US Societal Perspective

Rectal cancer is a major cause of morbidity and mortality in the United States. Development and validation of newer technologies has made the treatment for locally advanced rectal cancer a moving target. The study was undertaken to evaluate the cost-effectiveness of short-course (SC) radiotherapy (RT) against long-course (LC) chemoradiotherapy (CRT) in the treatment of stage III rectal cancer from the US societal perspective. A four state Markov model was developed for this evaluation. Health outcomes and costs were discounted at 3% annually. The Trans-Tasman rectal trial informed the patient population and initial transition probabilities. Preoperative and postoperative treatment costs were evaluated using both CPT codes and the Veteran Affairs Federal Supply Schedule (FSS). Health state utilities were based on prior publications. One-way and probabilistic sensitivity analyses (PSA) were conducted to estimate the model’s robustness. SC RT dominated LC CRT. It yielded 0.07 more life years and 0.08 QALYs while costing more than $23,000 less. The resulting incremental Net Monetary Benefit (NMB) at baseline was over $34,000 in favor of SC RT at $150,000 willingness-to-pay (WTP) threshold. The one-way sensitivity analysis showed that the probability of distant recurrence in either arm was the most sensitive parameter, while the PSA illustrated the similarities between the two arms in terms of both costs and QALYs. In all, SC had a 70-71% likelihood of being cost-effective at WTP threshold of $100,000 or higher. To date, this is the first cost effectiveness model evaluating SC RT and LC CRT from the US societal perspective. The base case and PSA outcomes demonstrate that SC RT is likely more cost-effective. Distant recurrence is the main driver of morbidity, mortality, and costs in this model. Future research should focus on providing robust cost and health state utility estimates for these patients.

Visualization of logistic algorithm in Wilson model

Economic order quantity (EOQ), defined by the Wilson's model, is widely used at different stages of production and distribution of different products. It is useful for making decisions in the management of inventories, providing a more efficient business operation and thus bringing more economic benefits. There is a large amount of reference material and extensive computer shells that help solving various logistics problems. However, the use of large computer environments is not always justified and requires special user training. A tense supply schedule in a logistics model is optimal, if, and only if, the planning horizon coincides with the beginning of the next possible delivery. For all other possible planning horizons, this plan is not optimal. It is significant that when the planning horizon changes, the plan changes immediately throughout the entire supply chain. In this paper, an algorithm and a program for visualizing models of the optimal value of supplies and their number, depending on the magnitude of the planned horizon, have been obtained. The program allows one to trace (visually and quickly) all main parameters of the optimal plan on the charts. The results of the paper represent a part of the authors’ research work in the field of optimization of protection and support services of ports in the Russian North.

Statistical model checking of relief supply location and distribution in natural disaster management

Examining the efficacy of natural disaster management readiness and response activities is challenging due to the involvement of many random and uncertain components. These uncertainties can be captured by stochastic models. The analysis of these models is carried out using Monte Carlo simulations to judge the effectiveness of natural disaster management solutions. However, this approach uses static estimators, which generally rely on sampled number of events taken from the random space. The safety-critical nature of disaster management requires a more quantifiable analysis. In order to overcome this challenge, we propose to use statistical model checking for relief supply location and distribution in natural disaster management. For illustration purposes, we use the PRISM model checker to model and analyze a real-world scenario of relief supply location and distribution while considering some key factors, like demand of medical supplies at hospitals, predestined routes from warehouses to hospitals, capacity of warehouses and transportation plans.

Accounting for the Boundary Problem at Subnational Level: The Supply–Demand Balance of Biomass Cooking Fuels in Kitui County, Kenya

In sub-Saharan Africa, the high demand for wood-based cooking fuels calls for urgent policy action to steer the cooking energy sector towards more sustainability. While the subnational scale is growing in importance for policy planning, current energy assessments still only consider individual entities without taking into account resource flows. Ignoring flows of biomass cooking fuels in supply–demand assessments is a system boundary problem that can lead to misleading policy recommendations. In this paper, we tackle the boundary problem in subnational supply–demand assessments and provide a tool to support knowledge-based decision-making on the management of biomass cooking fuels in sub-Saharan Africa. Using Kitui County as a case study, we developed and tested an approach consisting of a supply model, local demand model, balance model, availability model, and adjusted balance model. The balance model only considers local fuel supplies and demand, whereas the adjusted balance model also considers external demand, which reduces the locally available supply of fuel. The results show that fuel demand and supply are spatially heterogeneous and vary between wood-based and non-woody fuels, and that the transport distance of fuels strongly affects local fuel availability and determines whether the supply–demand balance is positive or negative. We conclude that subnational energy policies should consider geographical distribution of supply and demand, aim to increase the fuel mix, consider external demand in supply–demand assessments, and differentiate between fuels for self-consumption and the market.

Active monetary policy and the slowdown: Evidence from DSGE based Indian aggregate demand and supply

We explore reasons for the strongly asymmetric Indian monetary transmission and response to other shocks, compared to those of the United States, obtained in a standard New Keynesian Dynamic Stochastic General Equilibrium (DSGE) model. While counterfactual analysis moderates other impulse responses, it suggests large cost shocks remain a primitive cause of inflation, and the strong transmission comes from large interest rate changes. Reducing the variance of the interest rate shock can significantly moderate the large output cost. Asymmetric excess volatility due to preference and technology shocks is reduced on introducing regime switching between multiple steady-states. The estimated model including multiple regimes is therefore used to obtain aggregate demand and aggregate supply schedules, which incorporate the policy reaction function, and to identify their shifts during the Indian slowdown. The correlation between factors shifting aggregate demand and supply is estimated. Since it is negative it aggravates the shocks. The post 2011 slowdown is explained by severe demand contraction in response to adverse supply shocks. Habit persistence in consumption changes the slope of both aggregate demand and supply curves significantly.

Strategic Bidding of Electric Power Generating Companies: Evidence from the Australian National Energy Market

We extend existing theoretical frameworks describing electricity markets where each generator provides a Market Operator (MO) with a supply schedule in advance. The MO combines these with demand forecasts to produce equilibrium prices and instructs firms on their dispatch. We incorporate the possibility that generating firms may rebid (or revise) their supply schedule prior to dispatch - an important feature of markets in many countries which has not previously been included in theoretical models. We show that a dominant firm can gain substantially by manipulating its bids, and take advantage of the opportunity to submit rebids. In the Australian National Energy Market (NEM) where settlement prices are an average of six dispatch prices, it can, for example, withhold capacity at lower prices for the first bid in a period, creating a price hike, and then add capacity at lower prices to ensure dispatch. Using data from the Australian NEM we provide the first empirical evidence consistent with the hypothesized theoretical behaviour in the observed data.

Dayahead Electricity Pricing for a Heterogeneous Microgrid Under Arbitrary Utility and Cost Structures

In this paper, we consider the dayahead load and supply allocation problem in an electrical microgrid, which consists of a system manager, consumers, and suppliers. We do not impose any mathematical, operational, and economic assumptions on the consumers and suppliers other than restricting them to have a finite number of load and supply schedules. For example, a consumer can have arbitrary forms of flexibilities in its demand, such as deferrability or intermittence, and the user can choose from a set of predetermined load allocations that represent these flexibilities. Thus, our system model can accommodate heterogeneous user requirements and constraints in the same problem formulation. Under this system model, we formulate a welfare maximization problem, and derive a distributed primal–dual pricing algorithm. In our algorithm, the system manager generates prices for the load and supply allocations of the users, and given these prices, the users independently choose the schedules to their best operational and economic interests. Furthermore, the pricing algorithm incentivizes the users so that their decisions benefit the system performance, and it achieves the optimal load and supply allocation. Finally, we study the algorithm’s performance via simulations and demonstrate how the demand-side flexibilities are utilized for the system’s benefit.