Dynamic Shared‐Taxi Dispatch Algorithm with Hybrid‐Simulated Annealing

Taxi is certainly the most popular type of on‐demand transportation service in urban areas because taxi‐dispatching systems offer more and better services in terms of shorter wait times and passenger travel convenience. However, a shortage of taxicabs has always been critical in many urban contexts especially during peak hours, and taxi has great potential to maximize its efficiency by employing the shared‐ride concept. There are recent successes in dynamic ride‐sharing projects that are expected to bring substantial benefits arising from energy consumption and operation efficiency and thus, it is essential to develop advanced shared‐taxi‐dispatch algorithms and investigate the collective benefits of dynamic ride‐sharing by maximizing occupancy and minimizing travel times in real‐time. This article investigates how taxi services can be improved by proposing shared‐taxi algorithms and what type of objective functions and constraints could be employed to prevent excessive passenger detours. Hybrid‐simulated annealing (HSA) is applied to dynamically assign passenger requests efficiently. A series of simulations are conducted with two different taxi operation strategies. The simulation results reveal that allowing ride‐sharing for taxicabs increases productivity over the various demand levels and HSA can be considered as a suitable solution to maximize the system efficiency of dynamic ride‐sharing.     

Valuing a price cap contract for material procurement as a real option

This paper uses real option methodology to compare the cost of a long‐term contract with a price cap to that of spot purchases in construction material procurement. In construction, material procurements are usually short‐term, project‐based and subject to high price volatility. These characteristics and the competitive nature of the industry lower the profit margin of contractors. We have observed that contractors purchase a stable amount of commodity materials such as concrete, structural steel and lumber year after year. For contractors, the price cap reduces the price volatility of materials without their being obliged to purchase a certain quantity; for suppliers, the price‐cap contracts give them steady demand and a bigger market share. We evaluate this price‐cap contract as a real option and find the contractor's optimal ordering policy. When materials are not frequently traded, we model price processes by using related market information and then evaluate the idiosyncratic uncertainties in a risk‐neutral setting. Our methodology does not require market completeness and incorporates some of the results of the latest research in finance such as correlation pricing, option pricing and zero level pricing, as well as Monte Carlo simulation.     

Price‐sensitive demand and market entry

This paper revisits the optimal entry decision in a differentiated product market where customer demand is price‐sensitive and depends on a per‐unit transport cost. We show that compared to the socially optimal outcome, too few firms may enter when entry costs and transport costs are high.     

Optimal pricing and environmental improvement for a hazardous waste disposal supply chain with emission penalties

Hazardous waste management has become a municipal problem, associated with industrial development and changing consumption patterns. We study the hazardous waste management system as a supply chain with a disposal facility and a contractor, which serves customers with demand sensitive to price and environment impact. The government intervenes with this supply chain by imposing emission penalties that make the waste disposal facility responsible for reducing disposal process emissions. The Stackelberg game and Nash equilibrium are used to model the decision-making sequence between the disposal facility and the contractor. We specify different scenarios to model the hazardous waste management supply chain. The goal of this research is to find the optimal disposal service price and level of environmental improvement to mitigate adverse impacts and maximize profits. The applicability of dual-channel service in the hazardous waste supply chain is also investigated. Our study shows that the supply chain obtains the highest profit if both the disposal facility and the contractor operate in a centralized model. Under some scenarios, profitability improves if the disposal facility becomes active in waste collection and transportation under a dual-channel supply-chain model. Demand sensitivity to price and environmental impacts can affect the adopted level of improvement by disposal facilities.     

Optimal microgrid programming based on an energy storage system,price-based demand response,and distributed renewable energy resources

Microgrids (MGs) in distribution systems can be operated in far regions at lower investment costs using renewable distributed energy resources (DERs). The present paper introduces a stochastic model for optimal energy-heat programming and the daily storage of an MG. Bi-level stochastic programming is presented for integrated energy-heat scheduling and storage in the presence of an energy storage system (ESS) and demand response (DR) based on social welfare maximization. Out of the incentive-based DR programs, the tender and redemption and the ancillary services market programs were selected and applied to the given model. Besides, the time of use (TOU) -based DR and real-time pricing (RTP) were considered as the price-based demand response (PBDR) programs in optimal programming. The PBDR programs have been included in the objective function using a linear function based on consumer benefits. The proposed bi-level stochastic model was solved using a developed metaheuristic optimization algorithm called the lightning search algorithm (LSA) in the present work. The Latin hypercube sampling (LHS) and KMEANS methods were used to produce and reduce the scenario. The proposed framework was investigated in a 33-bus test model. The obtained simulation results were evaluated from different aspects. The TOU and RTP effects and ESS are shown in obtained numerical analysis by considering the operating cost, total social welfare, and the client's utility function.     

Cities,regions and privatised utilities

Utility networks are physically embedded in places and they also operate within a regulated environment which imposes obligations on them. Within this framework they need to demonstrate commercial success which is directly related to new management strategies that have profound implications for the economic social and environmental performance of localities and regions. Privatisation and liberalisation have heralded a movement from relatively uniform service provision to a utility patchwork with increased variations in tariffs, and styles of service provision. Realisation amongst urban studies and policy makers communities that utility strategies raise important issues for urban and regional development has been slow to emerge. But this is now rapidly changing. Voluntary and community groups and charities have attempted to ensure that low income households gain access to affordable water, heat, light and communication services. Economic development agencies have begun to realise that utilities can act as powerful allies for attracting inward investment. More slowly, they are turning attention to the implications of take-overs and job losses. Environmental groups have recognised the benefits of policies to cut demand and are working with utility companies on energy and water saving strategies. This paper explores the socio-spatial implications of emerging utility strategies within contemporary UK cities.     

城市出租汽车需求量预测模型及应用

分析了我国出租汽车现状保有量和影响出租汽车需求量的各方面因素,提出了基于神经网络理论的出租汽车需求量预测模型,并在算例中从影响出租汽车容量的各因素入手对成都市出租汽车需求量进行预测。     

Modeling,equilibrium, and demand management for mobility and delivery services in Mobility-as-a-Service ecosystems

Mobility-as-a-Service (MaaS) is an emerging business model integrating various travel modes into a single mobility service accessible on demand. Besides the on-demand mobility services, instant delivery services have increased rapidly and particularly boomed during the coronavirus (COVID-19) pandemic, requiring online orders to be delivered timely. In this study, to deal with the redundant mobility resources and high costs of instant delivery services, we model an MaaS ecosystem that provides mobility and instant delivery services by sharing the same multimodal transport system. We derive a two-class bundle choice user equilibrium (BUE) for mobility and delivery users in the MaaS ecosystems. We propose a bilateral surcharge–reward scheme (BSRS) to manage the integrated mobility and delivery demand in different incentive scenarios. We further formulate a bilevel programming problem to optimize the proposed BSRS, where the upper level problem aims to minimize the total system equilibrium costs of mobility and delivery users, and the lower level problem is the derived two-class BUE with BSRS. We analyze the optimal operational strategies of the BSRS and develop a solution algorithm for the proposed bilevel programming problem based on the system performance under BSRS. Numerical studies conducted with real-world data validate the theoretical analysis, highlight the computational efficiency of the proposed algorithm, and indicate the benefits of the BSRS in managing the integrated mobility and delivery demand and reducing total system equilibrium costs of the MaaS ecosystems.     

Robust Optimal Lane Allocation for Isolated Intersections

Lane allocation including approach and exit lane numbers and lane markings of approach lanes plays an important role in improving the capacity of an intersection. Conventional approaches for optimizing lane allocation often ignore fluctuations in traffic demand (TD). This article presents a stochastic model for robust optimal lane allocation of an isolated intersection under stochastic traffic conditions. This model is built in three steps. In the first step, an enhanced lane‐based model in the form of a binary mixed‐integer nonlinear program is proposed to optimize lane allocation and traffic signals for both vehicles and pedestrians in a unified framework under deterministic traffic conditions. In the second step, a two‐level stochastic model is developed to obtain a robust lane allocation that is less sensitive to traffic flow fluctuations considering the flexibility of traffic signals. In the third step, the two‐level model is further transformed into a TD‐based stochastic model in a two‐phase form to reduce the solution dimension for efficient computation. A TD‐based genetic algorithm procedure is presented for solvability. Numerical studies are conducted to validate the model formulations and solution algorithms.     

Supply and Demand for Low Energy Housing in the UK: Insights from a Science and Technology Studies Approach

Economic theory about supply and demand suggests that if consumer demand for a product increases then producers respond by increasing supply. In the UK housing market there is emerging evidence of consumer demand for low energy housing, yet little has been built to date by private sector housebuilders: existing low energy housing is largely within the social housing and self-build sectors. Ideas from science and technology studies (STS) are introduced to help further understanding of why the housing market might be slow to respond to changing consumer preferences. Although standard economic concepts concerning costs and price are able in part to explain the situation, greater attention to socio-technical issues highlights some of the reasons why innovation and change are difficult to effect. The housing market is best viewed as a socio-technical system, whereby the social and the technical are interlinked.     

A dynamic competition model for construction contractors

In construction, the issue of competition has been studied focusing on competitive bidding. The objective of most competitive bidding models is to find the optimum mark‐up to maximise the expected profit from a single firm's perspective. However, a firm's success depends on its long‐term interactions with the market and its competitors. To better understand competition in the market, there is a need to analyse competition from a dynamic market perspective. Building on previous models and relevant competition studies, a dynamic simulation model has been developed to provide an analytical framework for understanding dynamic competition. In this model, similar firms are equally exposed to demand uncertainties. Each applies its own policy, responding to market changes and to competitors' actions to optimise its market position. The firms' responses and their dynamic feedback are simulated and analysed. The results show how difficult it is for any firm to acquire a long‐term competitive advantage by means of bidding/marketing strategies—just as it is in the real world of price‐competitive contracting. Some considerations are presented for a single firm to develop a competitive strategy.     

An economic modelling approach for public sector construction workload planning

The effectiveness of public sector construction workload planning can be enhanced through employing an economic modelling approach to predict the impact of different workloads on tender price changes. The main problem associated with existing methods used for predicting tender price index (TPI) for construction projects is a lack of robustness when the market becomes unstable. This is due to limited consideration of market conditions in these methods. An economic modelling approach has been developed and applied for public sector construction workload planning in the States of Guernsey where forward planning was required. The developed model overcomes the problem of existing methods—lack of robustness—by correlating TPI of construction projects to demand over capacity ratio of the industry, which represents the industry's economic condition. The model generates the price changes under different planning options associated with different workloads over a five‐year planning period. The information is valuable to the public sector in estimating actually required investment. This ensures the feasibility of the plan and the possibility of contribution to the stability of the construction market. The model development and application process developed in this research can be used to assist a planning process for an industry where a demand, capacity and price relationship is applied.     

Industry views on water resources planning methods – prospects for change in England and Wales

This paper describes a qualitative study of practitioner perspectives on regulated water resources planning practice in England and Wales. The study focuses on strengths and weaknesses of existing practice and the case for change towards a risk‐based approach informed by stochastic modelling assessments. In‐depth, structured interviews were conducted to capture the views of planners, regulators and consultants closely involved in the planning process. We found broad agreement that the existing water availability assessment methods are fallible; they lack transparency, are often highly subjective and may fail to adequately expose problems of resilience. While most practitioners believe these issues warrant a more detailed examination of risk in the planning process, few believe there is a strong case for a fundamental shift towards risk‐based planning informed by stochastic modelling assessments. The study identifies perceived business risks associated with change and exposes widespread scepticism of stochastic methods.     

The determinants of informal housing price in Beijing: Village power,informal institutions,and property security

Although the how's of the informal housing market in China has been discussed widely; the answers remain conflicted. Using the theory of new institutional economics, this paper aims to answer two questions: what informal institutions secure the de facto tenure and facilitate the market? and How do informal institutions affect the pricing mechanism? We propose a conceptual framework to investigate the links between informal institutions, de facto tenure, and the price of informal housing. It is argued that villages have the ability to seek political patronage and regulate the market transactions to secure the tenure of informal housing. This ability is authorized by several formalities: the dual land system and the regime of village autonomy. The growing powers of market agencies in local development help strengthen the village's ability. The variances in ability between villages lead to a heterogeneity of tenure security, thus creating price differentials in the market. A higher tenure security increases the housing price. In conclusion, the informal housing market in China is “regulated” by a “semi-formal” system in which both informality and formality work and intertwine. A robust pricing mechanism has been emerging within the context of transition.     

Methoden zum Einsatz diskreter,webbasierter Wetterprognosen in Gebäudetechnik und Lastmanagement

Using Discrete Online Weather Forecasts for Building Services Applications and Load Management. Usually, commercially used hourly weather forecasts of national weather institutes are implemented for predictive control strategies. Energy demand and energy loads are calculated by utilizing adequate models with predicted air temperatures. However, on the internet, numerous providers offer freely available weather forecasts. Mostly forecasts of maximum and minimum outside air temperatures are available for five to nine days in advance. Many applications in building services do require hourly or quarter‐hourly data. This paper describes a method for generating weather data of any resolution for freely available weather forecasts issued by online services. Ice storage and load prediction of a building are cited as examples of predictive control strategies using web‐based weather forecasts.     

A model for water sharing in the Ganges River Basin

This study investigates water resources sharing and in particular the impact of the Farakka Barrage in the Ganges River Basin management which has led to conflict between the Ganges states since 1951. A deadlock prevailed between Bangladesh and India during the dry seasons. The 1996 water sharing treaty adopted and the results suggest that availability of flows is crucial during the period 1 March to 31 May. Moreover, the average flow availability at Farakka dam has been gradually declining during the period 1997 to 2007. For 2005 and 2006, it was found that the average flow availability declined by 12 and 25%, respectively. A Stackelberg leader–follower model is described for optimal water allocation in the Ganges River Basin between Bangladesh and India both with and without additional water transfers from Nepal. It is recommended that a market‐based water transfer arrangement from Nepal is implemented for both Bangladesh and India.     

2003—2012年武汉市房地产泡沬研究

房地产业是我国国民经济中的支柱产业,在整个国民经济体系中具有十分重要的地位。房地产市场的健康发展能有效的拉动社会经济的健康发展。武汉市的房地产业随着经济的发展和人们的生活水平的不断提高得到迅猛发展,房价也随着人们的刚性需求和投资投机性需求的增长不断攀升。该文从供给、需求、价格三个不同角度选取七个指标进行比对来研究武汉市房地产泡沫状况,表明2003年—2012年10年间,武汉市房地产的多数指标均超过相应的房地产泡沬参考值,武汉市的房地产市场己经存在了泡沬。     

The housing provision chain as a comparative analytical framework

This article argues a number of points, some to do with comparative analysis and some with political choices. In relation to comparative housing study it argues that: Ex‐socialist systems in transition are seeking to learn partly by drawing on western housing experience; comparative study to form the basis for this learning depends upon a sound analytical framework; the Housing Provision Chain model provides one such framwork; the “private/public” division is better seen as a “democratic/non‐democratic division”; the various stages of the Chain and the various forms of subsidy input need to be clearly separated out. In relation to policy‐making it argues that: The notion of housing provision by “free market plus safety net” is fallacious; all western markets are carefully regulated; the central financial question concerns the distribution of state support between supply and demand side subsidies; the central political question concerns the distribution of power, money and initiative between the Democratic and Non‐democratic sectors; the questions of the optimal tenure mix needs to be approached pragmatically not ideologically.     

基于Android的景区景点路线推荐服务研究

移动空间信息服务是移动网络、互联网、空间信息服务、移动终端技术协同发展的产物,是一种基于位置的空间信息服务。本文从移动空间信息服务关键技术探讨基于路线推荐服务的研究方法,设计并编程实现了一个基于特定景区景点的满足用户时间需求的旅游路线推荐服务软件。该软件基于Android平台,使用了SQLite数据库等多种技术,实现了基于用户所在景点的景区概况介绍、景区风景欣赏以及根据用户现有时间推荐最优旅游路线和到达出口的最优旅游路线推荐服务等功能。     

基于博弈论的建设工程投标报价模型分析

从投标报价行为的竞争性角度对最低价中标机制下投标者的报价问题进行研究。在分析报价博弈过程的基础上,建立了基于不完全信息博弈论的报价数学模型,结合企业追求期望利润最大化的目标,对企业竞标成功的概率进行详细的分析,并给出了满足企业期望效益最大的最优报价方法。