Demand-based Method Research Articles

Multi-airport system flight slot optimization method based on absolute fairness.

With the rapid development of the civil aviation industry, the number of flights has increased rapidly. However, the availability of flight slot resources remains limited, and how to allocate flight slot resources effectively has been a hot research topic in recent years. A comprehensive flight slot optimization method can significantly enhance the rationality of the allocation results. The effective allocation of flight slot is the key to improving the operational efficiency of the multi-airport system. We will optimize the flight schedule of the entire multi-airport system considering the fairness of each airport in it. The optimization results will provide an important reference for the reasonable allocation of flight slot within the multi-airport system. Based on the operation characteristics of the multi-airport system, we have established a multi-objective flight slot allocation optimization model. In this model, we set the airport capacity limit, shared waypoint capacity limit and aircraft turnaround time limit as the constraints. The optimization goal of the model is to minimize total flight schedule displacement and the maximum deviation of fairness from the absolute fairness. Gurobi solver is used to solve the model. We have innovatively incorporated the rolling capacity constraint method into our model to ensure more accurate flight slot allocation results. The Beijing-Tianjin-Hebei regional multi-airport system is selected as an example to verify the above model, and the flight slot optimization results have successfully met the fairness goal. The comparative analysis has demonstrated that the rolling capacity constraint method significantly improves the accuracy of solution results, leading to more stable flight slot allocation. The results also prove that the flight slot allocation method of multi-airport system based on absolute fairness of peak demand can improve the fairness of the allocation results. To achieve a higher level of fairness, we have found that the peak-demand based fairness method requires a smaller slot displacement compared to the non-peak demand-based method. Through the optimization of flight slot of the multi-airport system, the coordination between airports can be significantly improved. It can provide a new solution for the efficient operation of the multi-airport system.

Strategic Pricing of Bee Products from the Ruse Region

The study reveals that in the context of global competition in supply, limited demand, and product parity in the B2B and B2C markets for bee products, there are significant limitations on the applicability of cost pricing methods (cost and desired profit) and partly of demand-based methods. In addition, the study shows that the most applicable pricing methods are the ones based on competition. Regional honey, the main product of beekeeping in the Ruse region, has a negligible differentiated value (monetary and psychological) in the B2B and B2C markets compared to its competing counterparts, due to which its price fluctuates around its market price. The lack of product differentiation, as well as established regional image and brand nowadays, do not allow producers to achieve prices higher than the market ones. Beekeeping farms in the Ruse region should build horizontal and vertical strategic relationships to gain price leadership through low costs and high quality. Value communication is necessary to protect the value and importance of regional bee products from competitors. This should be done by increasing the willingness of customers to pay a higher price for them. The pricing policy of beekeeping farms defines the general price behaviour based on the achieved differentiated value of the regional bee products and its continuous increase. The formation of regional bee products with high added value has a decisive role in the positive perception of the price by the different segments, due to which they reach higher price levels.

Improved characterisation of unmetered stock and domestic groundwater use in the Surat and Southern Bowen basins of the Great Artesian Basin (Australia)

Time-series and current estimates of groundwater use are critical for conceptualisation of groundwater systems and for understanding system responses. A key challenge for managing Australia’s Great Artesian Basin (GAB) is the limited available data on water use. In the absence of an existing method, the Queensland Government’s Office of Groundwater Impact Assessment developed a demand-based method to estimate unmetered stock and domestic (S&D) groundwater use in 2016, with further enhancements since then. The method integrates publicly available datasets including property grazing potential and availability of other water supplies to derive a range of groundwater use estimates. The method also distributes the estimated demand for groundwater use across water supply bores and across screened geological formations based on bore construction and screened-aquifer information. The method has been applied to the GAB’s Surat and southern Bowen basins. Integrating the results and outcomes from related research projects, this article provides an overview of the demand-based method, highlighting new understanding of the temporal and spatial distribution of groundwater use. Results were validated at the bore scale with limited metered bore data, and at the sub-regional level from census data and landholder survey information. Across the Surat Basin, comparisons with previous estimates show, as estimated, a reduction in S&D water extraction from approximately 80,000 to 25,000 ML/year.

Demand-Based Optimal Design of Storage Tank with Inerter System

A parameter optimal design method for a tank with an inerter system is proposed in this study based on the requirements of tank vibration control to improve the effectiveness and efficiency of vibration control. Moreover, a response indicator and a cost control indicator are selected based on the control targets for liquid storage tanks for simultaneously minimizing the dynamic response and controlling costs. These indicators are reformulated through a random vibration analysis under virtual excitation. The problem is then transformed from a multiobjective optimization problem to a single-objective nonlinear problem using the ε-constraint method, which is consistent with the demand-based method. White noise excitation can be used to design the tank with the inerter system under seismic excitation to simplify the calculation. Subsequently, a MATLAB-based calculation program is compiled, and several optimization cases are examined under different excitation conditions. The effectiveness of the demand-based method is proven through a time history analysis. The results show that specific vibration control requirements can be met at the lowest cost with a simultaneous reduction in base shears and overturning base moments.

Rheumatology Workforce Planning in Western Countries: A Systematic Literature Review.

To compare health care planning models forecasting rheumatology workforce requirements in western countries. A systematic literature review was conducted through medical databases (Ovid MEDLINE, Embase, CINAHL, and Cochrane Library) and the grey literature. All articles reporting a rheumatology workforce model were included. The search yielded 6,508 articles, and 14 publications (on 12 studies) were included. Workforce models were available for the US (n = 3), Canada (n = 3), the US plus Canada (n = 1), Germany (n = 2), Spain (n = 1), and the UK (n = 2). The number of rheumatologists required to serve a population of 100,000 people was calculated, with a range of 0.7 (UK, calculated for 1988) to 3.5 (Spain, calculated for 2021). Most models used a needs-based approach (n = 6); 3 studies each applied a supply- or demand-based method. The following variables were considered by ≥1 model: disease prevalence, patients' referral to rheumatologists, clinical visits/patient/year, population development, factors influencing performance of rheumatologists, patient flow/care sharing, and medical technologies/infrastructure development. Heterogeneity in methods used, the period or calendar years for which the estimates were projected, and heterogeneity of variables evaluated led to disparate estimates, with results ranging from 0.7 to 3.5 rheumatologists per 100,000 population. An international initiative is needed to agree upon a common approach for a reliable estimation of manpower requirements in rheumatology.

Infodemiology and Infoveillance: Framework for an Emerging Set of Public Health Informatics Methods to Analyze Search, Communication and Publication Behavior on the Internet

Infodemiology can be defined as the science of distribution and determinants of information in an electronic medium, specifically the Internet, or in a population, with the ultimate aim to inform public health and public policy. Infodemiology data can be collected and analyzed in near real time. Examples for infodemiology applications include: the analysis of queries from Internet search engines to predict disease outbreaks (eg. influenza); monitoring peoples' status updates on microblogs such as Twitter for syndromic surveillance; detecting and quantifying disparities in health information availability; identifying and monitoring of public health relevant publications on the Internet (eg. anti-vaccination sites, but also news articles or expert-curated outbreak reports); automated tools to measure information diffusion and knowledge translation, and tracking the effectiveness of health marketing campaigns. Moreover, analyzing how people search and navigate the Internet for health-related information, as well as how they communicate and share this information, can provide valuable insights into health-related behavior of populations. Seven years after the infodemiology concept was first introduced, this paper revisits the emerging fields of infodemiology and infoveillance and proposes an expanded framework, introducing some basic metrics such as information prevalence, concept occurrence ratios, and information incidence. The framework distinguishes supply-based applications (analyzing what is being published on the Internet, eg. on Web sites, newsgroups, blogs, microblogs and social media) from demand-based methods (search and navigation behavior), and further distinguishes passive from active infoveillance methods. Infodemiology metrics follow population health relevant events or predict them. Thus, these metrics and methods are potentially useful for public health practice and research, and should be further developed and standardized.

The orthopaedic workforce: which rate is right?

Since the 1970s, the number of clinically active specialists in the United States per 100,000 population has more than doubled. For example, the number of orthopaedic surgeons increased from 3.6 in 1970 to 7.1 currently (Fig. 1). The increase in the supply of physicians has been associated with an increase in per capita costs and in utilization of specialist care. As a result of this escalation in health-care spending, the federal government has called for a dramatic change in the way in which they support graduate medical education. In this new scenario, institutions would be rewarded for reducing the number of residency trainees3. Fig. 1 Map showing the ratios of orthopaedic surgeons per 10,000 United States residents by hospital referral region in the United States in 1996 (Dartmouth Atlas Working Group, Hanover, New Hampshire, 1998). However, it is necessary to determine how many physicians are needed. In order to do this prudently, the organizations that are responsible for the education and training of future orthopaedists commissioned a study by the RAND Corporation4. The results of this study, which appear in this issue of The Journal, indicate a current excess of 3546 orthopaedic surgeons, which will increase to 4122 by the year 2010. The RAND researchers4 obtained these estimates of excess capacity by applying what they characterize as a demand-based method to estimate workforce requirements. According to their definition, demand is the same as the average utilization rate for the nation. They estimated this rate for services provided by orthopaedic surgeons by using several databases that, taken together, cover the major sectors in which orthopaedic care is provided: physicians' offices, ambulatory care centers, and hospitals. The number of full-time-equivalent orthopaedists required to provide services for the nation was then calculated on the basis of the rate …

Working set generation methods for labor tour scheduling

Working set methods in labor scheduling generally consist of a generation and implementation phase. The generation phase involves the selection of a subset of work schedules from the complete (master) set of all allowed work schedules. In the implementation phase, either heuristic or integer optimal solutions are obtained upon the basis of the schedules in the working set. We classify previous working set generation procedures as being either structural, demand-based, or refinement. Two new working set procedures within the first category and one new procedure within the second category are developed. Subsequently, we compare the efficacy of the new and previously published generation procedures within the context of a discontinuous tour scheduling environment where the sole objective is minimization of total labor hours scheduled. All comparative analysis was based upon the global integer optimal solutions to problems posed by the master set associated with 36 different labor requirements distributions. The second of the new structural methods resulted in the best performance for all working set sizes. In particular, it resulted in global integer optimal solutions, for all test problems, with working set sizes of 40 and 50. The new demand-based method resulted in the second best performance at a working set size of 50. We conclude with a discussion of the implications of the results for future research and practice.

PRICING BEHAVIOUR OF SMALL FIRMS: AN EMPIRICAL ANALYSIS

ABSTRACT This exploratory study of 247 small firms representing the manufacturing, service and trade sectors attempts to provide a description of the pricing behaviour of small businesses and insights as to the extent to which they reason about pricing decisions. The results suggest that pricing practice among small firms is primarily costoriented, intuitive, mechanical and simplistic. Only a small minority use sophisticated techniques such as marginal analysis, demand-based methods or market research to determine optimum price levels. Yet, despite the shortcomings of the pricing methods used, there is evidence of an effort on the part of small firms to maximize profits through less-sophisticated pricing methods. The study also uncovered an unwillingness among small businesses to lower or raise prices according to market conditions. This lack of flexibility places small firms in a weak position and renders them ineffective in adapting to demand and market pressures.