Locating of Series FACTS Devices for Multi-Objective Congestion Management Using Components of Nodal Prices

Directory of Open Access Journals (Sweden)

A. R. Moradi

2017-03-01

Full Text Available Congestion and overloading for lines are the main problems in the exploitation of power grids. The consequences of these problems in deregulated systems can be mentioned as sudden jumps in prices in some parts of the power system, lead to an increase in market power and reduction of competition in it. FACTS devices are efficient, powerful and economical tools in controlling power flows through transmission lines that play a fundamental role in congestion management. However, after removing congestion, power systems due to targeting security restrictions may be managed with a lower voltage or transient stability rather than before removing. Thus, power system stability should be considered within the construction of congestion management. In this paper, a multi-objective structure is presented for congestion management that simultaneously optimizes goals such as total operating cost, voltage and transient security. In order to achieve the desired goals, locating and sizing of series FACTS devices are done with using components of nodal prices and the newly developed grey wolf optimizer (GWO algorithm, respectively. In order to evaluate reliability of mentioned approaches, a simulation is done on the 39-bus New England network.

Sustainable energy management in urban transport: The public's response of road congestion pricing in Thailand

International Nuclear Information System (INIS)

Kunchornrat, Janthana; Pairintra, Rattanachai; Namprakai, Pichai

2008-01-01

Fuel consumption of vehicles is one of the most vigorously debated issues in Thailand. Concerns about the effect of emissions from the vehicles and a significant reliance on imported oil provide legitimate reasons for government action to manage fuel consumption. There are several different policy measures available to affect the fuel-efficient vehicles as well as reduce the amount of driving. This paper presents the major policy measure studies namely congestion pricing, etc. In congestion pricing measure, we conducted a survey of 400 samples in Bangkok area. The purpose of the survey was to inform respondents about a policy designed to reduce freeway congestion and to estimate respondent support for this policy. After receiving extensive information about the policy, respondents were polled on whether they would support, i.e., vote for any or all of these options. The results of the congestion fee survey suggest that 22% of commuting motorists in Bangkok will support congestion fees on the freeways of the region. Public acceptance is substantially enhanced by promising to return at least some of the revenues in the form of reductions in other taxes. (author)

Financial and technical feasibility of dynamic congestion pricing as a revenue generation source in Indiana : exploiting the availability of real-time information and dynamic pricing technologies.

Science.gov (United States)

2011-10-19

"Highway stakeholders continue to support research studies that address critical issues of the current era, including congestion mitigation and revenue generation. A mechanism that addresses both concerns is congestion pricing which establishes a dir...

Influence of TCSC on congestion and spot price in electricity market with bilateral contract

International Nuclear Information System (INIS)

Acharya, Naresh; Mithulananthan, Nadarajah

2007-01-01

This paper presents a quantitative analysis of the effect of TCSC on congestion and spot price in deregulated electricity markets. The paper could also be considered as a comprehensive tutorial on the influence of TCSC in electricity market. A voluntary pool market, where the market participants can trade electricity either via a pool or through bilateral contracts is considered. The electricity market is modeled in an optimal power flow framework with the objective of maximizing the social welfare. In such formulation, the Lagrange operators associated with the equality constraints associated with real power balance give the spot prices of energy at each bus of the system. Studies are carried out with and without TCSC at peak and low loading conditions to capture the influence and to see the effectiveness of TCSC at different loading conditions. The paper further explores the effect of TCSC compensation level on the spot prices and the congestion under varying pool and bilateral loading conditions. A 5-bus test system is used for numerical studies and to showcase the influence of TCSC in an electricity market environment. (author)

Slot allocation on congested motorways : An alternative to congestion pricing

NARCIS (Netherlands)

Koolstra, K.

1999-01-01

With respect to the prevailing congestion problems in the more urbanised regions of the European Union, transportation planners and policymakers are facing a dilemma. Supply-side measures, i.e. increasing the capacities, might shorten the congestion duration, especially if bottlenecks can be

Agent-Based Model of Price Competition and Product Differentiation on Congested Networks

OpenAIRE

Lei Zhang; David Levinson; Shanjiang Zhu

2007-01-01

Using consistent agent-based techniques, this research models the decision-making processes of users and infrastructure owner/operators to explore the welfare consequence of price competition, capacity choice, and product differentiation on congested transportation networks. Component models include: (1) An agent-based travel demand model wherein each traveler has learning capabilities and unique characteristics (e.g. value of time); (2) Econometric facility provision cost models; and (3) Rep...

Contemporary approaches to congestion pricing : lessons learned from the national evaluation of congestion pricing strategies at six sites.

Science.gov (United States)

2015-08-01

This document represents the final report of the national evaluation of congestion reduction strategies at six sites that received federal funding under the Urban Partnership Agreement (UPA) and Congestion Reduction Demonstration (CRD) programs. The ...

Congestion levies; Congestieheffingen

Energy Technology Data Exchange (ETDEWEB)

Verhoef, E.T. [Vakgroep Ruimtelijke Economie, Vrije Universiteit en Tinbergen Instituut, Amsterdam (Netherlands)

1998-02-20

Traffic jams or congestion can be controlled by means of Pigouvian levies. Congestion costs comprise both time losses as scheduling costs. Because a part of those costs are external costs, the free market output is not Pareto-efficient, and therefore levies are required to recover the efficiency. With some restrictions, road-pricing for the western part of the Netherlands is considered to be a feasible option

Congestion management in Alberta

International Nuclear Information System (INIS)

Way, R.

2002-01-01

The challenges facing Alberta regarding electricity market design and congestion management were described. The electricity market in the province consists of a central power pool, an open access transmission network, and a single pool price, unlike many other jurisdictions in North America which have adopted a location margin price (LMP) design with significant price differences between various locations within the power network. Alberta's transmission network is regulated and provides carrier functions. Power moves freely throughout Alberta's power pool network with no congestion, therefore the common pool price signals market participants throughout the entire network with no segregation into zones. Alberta is currently at a cross road in choosing between a single pool price model or a nodal price model. In the first instance, the province would have to strengthen the transmission network to maintain the market at a reasonable size. The alternative would permit Alberta to use market-based techniques to deal with the evolution of many smaller markets in the province, but these would be very small by North American standards and their ability to compete would be questionable

Distribution Locational Marginal Pricing through Quadratic Programming for Congestion Management in Distribution Networks

DEFF Research Database (Denmark)

Huang, Shaojun; Wu, Qiuwei; Oren, Shmuel S.

2015-01-01

) calculates dynamic tariffs and publishes them to the aggregators, who make the optimal energy plans for the flexible demands. The DLMP through QP instead of linear programing as studied in previous literatures solves the multiple solution issue of the ag- gregator optimization which may cause......This paper presents the distribution locational mar- ginal pricing (DLMP) method through quadratic programming (QP) designed to alleviate the congestion that might occur in a distribution network with high penetration of flexible demands. In the DLMP method, the distribution system operator (DSO...

Endogenous scheduling preferences and congestion

DEFF Research Database (Denmark)

Fosgerau, Mogens; Small, Kenneth

2017-01-01

We consider the timing of activities through a dynamic model of commuting with congestion, in which workers care solely about leisure and consumption. Implicit preferences for the timing of the commute form endogenously due to temporal agglomeration economies. Equilibrium exists uniquely and is i......We consider the timing of activities through a dynamic model of commuting with congestion, in which workers care solely about leisure and consumption. Implicit preferences for the timing of the commute form endogenously due to temporal agglomeration economies. Equilibrium exists uniquely...... and is indistinguishable from that of a generalized version of the classical Vickrey bottleneck model, based on exogenous trip-timing preferences, but optimal policies differ: the Vickrey model will misstate the benefits of a capacity increase, it will underpredict the benefits of congestion pricing, and pricing may make...

Mathematical principles of road congestion pricing

African Journals Online (AJOL)

route during the morning peak hour: cost and demand functions. the same at all traffic levels. Although car running costs rise with increases in travel time in congested urban travel conditions, they are usually regarded by road users as being.

Risk management in electricity markets emphasizing transmission congestion

International Nuclear Information System (INIS)

Kristiansen, Tarjei

2004-01-01

This thesis analyzes transmission pricing, transmission congestion risks and their associated hedging instruments as well as mechanisms for stimulating investments in transmission expansion. An example of risk management in the case of a hydropower producer is included. After liberalization and restructuring of electricity markets, risk management has become important. In particular the thesis analyzes risks due to transmission congestion both in the short- and long-term (investments) for market players such as generators, loads, traders, independent system operators and merchant investors. The work is focused on the northeastern United States electricity markets and the Nordic electricity markets. The first part of the thesis reviews the literature related to the eight research papers in the thesis. This describes the risks that are relevant for an electricity market player and how these can be managed. Next, the basic ingredients of a competitive electricity market are described including the design of the system operator. The transmission pricing method is decisive for hedging against transmission congestion risks and there is an overview of transmission pricing models considering their similarities and differences. Depending on the transmission pricing method used, locational or area (zonal) pricing, the electricity market players can use financial transmission rights or Contracts for Differences, respectively. In the long-term it is important to create mechanisms for investments in transmission expansion and the thesis describes one possible approach and its potential problems. The second part comprises eight research papers. It presents empirical analyses of existing markets for transmission congestion derivatives, theoretical analyses of transmission congestion derivatives, modeling of merchant long-term financial transmission rights, theoretical analysis of the risks of the independent system operator in providing financial transmission rights, an analysis

Consumption, price asymmetries, transmission congestion and market power in the Norwegian electricity market

Energy Technology Data Exchange (ETDEWEB)

Mirza, Faisal Mehmood

2011-07-01

The results from this dissertation add to the ongoing debate in Norway if NordPool spot should shift from zonal price scheme to the nodal price scheme. Academically, the individual papers provide a number of theoretical frameworks that are helpful in analyzing electricity markets around the world. The PhD dissertation investigates price determination process in the Norwegian electricity market and evaluates if the market works at perfectly competitive level or producers exercise market power to drive prices away from their marginal cost of production. Using aggregate hourly electricity supply and demand data, the empirical analysis carried out in this dissertation leads to the following conclusions. 1. Market power at the generation level is not a major problem for the Norwegian electricity market. On average, when we consider the events of binding transmission capacity as exogenous, the average markup in economic terms is small and has not exceeded one percent. 2. Producers can use the information on available transmission capacity between different price areas in Norway and restrict their output to induce transmission congestion in their price area to exercise market power. Average markup during such instances has remained high at 20 percent. 3. Transmission capacity in Norway is not being optimally utilized as import capacity remains at its lowest level during the hours when southern Norway is generally a net importer of electricity, when compared to the rest of the hours of the day. 4. A segment of electricity retailers in the Norwegian electricity market exercises its market power by controlling the pass-through of price changes in the wholesale market to the retail market for variable price contract consumers. The pass-through is asymmetric, whereby cost increase is transmitted completely and quickly when compared to the case of cost decrease. 5.The Daylight saving time (Summer time) policy is helpful in ensuring energy efficiency. It results in electricity

Congestion management through topological corrections: A case study of Central Western Europe

International Nuclear Information System (INIS)

Han, Jinil; Papavasiliou, Anthony

2015-01-01

The integration of an increasing amount of renewable generation within Europe is posing operational challenges that require various balancing actions. System operators therefore need to rely increasingly on the active control of the transmission network. Transmission topology control is a fast and economical option to add flexibility to the transmission system. We model the current methodology for controlling congestion in the Central Western European (CWE) market and quantify the benefits of topology control. We also compare the results with a nodal pricing model. Our computational results suggest that topology control can significantly reduce congestion management costs under the current market coupling regime whereas the benefits of topology control are limited under nodal pricing. Topology control emerges as an attractive and implementable means of managing congestion as it provides a significant percentage of the cost savings that would be achieved by overhauling the existing European market design and shifting to a nodal pricing regime. - Highlights: • We present the congestion management model in the CWE region. • The benefits of topology control in the CWE region are quantified. • Topology control significantly reduce congestion under the current market coupling. • The benefits of topology control are limited under the nodal pricing regime. • Network topology control is a promising option for mitigating congestion in Europe.

London-type congestion tax with revenue-recycling

OpenAIRE

Yukihiro Kidokoro

2005-01-01

Road pricing in London attracts a great deal of interest. A challenging aspect of the London scheme is that congestion tax revenue is used to upgrade public transit networks. Although Parry and Bento (2001) show that the total social surplus would increase if congestion tax revenues are used to cut labor taxes, political difficulties exist in implementing revenue-recycling between congestion taxes and labor taxes. Given such political difficulties, the London scheme seems to be very attractiv...

Efficiency of equilibria in uniform matroid congestion games

NARCIS (Netherlands)

de Jong, Jasper; Klimm, Max; Uetz, Marc Jochen

2016-01-01

Network routing games, and more generally congestion games play a central role in algorithmic game theory, comparable to the role of the traveling salesman problem in combinatorial optimization. It is known that the price of anarchy is independent of the network topology for non-atomic congestion

Efficient determination of distribution tariffs for the prevention of congestion from EV Charging

DEFF Research Database (Denmark)

O'Connell, Niamh; Wu, Qiuwei; Østergaard, Jacob

2012-01-01

into the day-ahead market. The DT acts to disperse charging at congested periods and locations, thereby preventing congestion on a day-ahead basis. The magnitude of the DT is determined from a simulated locational marginal prices (LMPs), and the time extent of the DT is determined from analysis of the system...... loading curve prior to the application of the DT. Case studies were performed using a sample distribution network modelled on a network from the Danish island of Bornholm. A variety of price profiles were used to illustrate the efficacy of this approach. The case study results show that this approach...... is highly efficient at grid congestion prevention, and the precise level of congestion that can be alleviated is dependent on the price profile of the optimisation period in question....

Three essays on access pricing

Science.gov (United States)

Sydee, Ahmed Nasim

In the first essay, a theoretical model is developed to determine the time path of optimal access price in the telecommunications industry. Determining the optimal access price is an important issue in the economics of telecommunications. Setting a high access price discourages potential entrants; a low access price, on the other hand, amounts to confiscation of private property because the infrastructure already built by the incumbent is sunk. Furthermore, a low access price does not give the incumbent incentives to maintain the current network and to invest in new infrastructures. Much of the existing literature on access pricing suffers either from the limitations of a static framework or from the assumption that all costs are avoidable. The telecommunications industry is subject to high stranded costs and, therefore, to address this issue a dynamic model is imperative. This essay presents a dynamic model of one-way access pricing in which the compensation involved in deregulatory taking is formalized and then analyzed. The short run adjustment after deregulatory taking has occurred is carried out and discussed. The long run equilibrium is also analyzed. A time path for the Ramsey price is shown as the correct dynamic price of access. In the second essay, a theoretical model is developed to determine the time path of optimal access price for an infrastructure that is characterized by congestion and lumpy investment. Much of the theoretical literature on access pricing of infrastructure prescribes that the access price be set at the marginal cost of the infrastructure. In proposing this rule of access pricing, the conventional analysis assumes that infrastructure investments are infinitely divisible so that it makes sense to talk about the marginal cost of investment. Often it is the case that investments in infrastructure are lumpy and can only be made in large chunks, and this renders the marginal cost concept meaningless. In this essay, we formalize a model of

Research on Urban Road Traffic Congestion Charging Based on Sustainable Development

Science.gov (United States)

Ye, Sun

Traffic congestion is a major problem which bothers our urban traffic sustainable development at present. Congestion charging is an effective measure to alleviate urban traffic congestion. The paper first probes into several key issues such as the goal, the pricing, the scope, the method and the redistribution of congestion charging from theoretical angle. Then it introduces congestion charging practice in Singapore and London and draws conclusion and suggestion that traffic congestion charging should take scientific plan, support of public, public transportation development as the premise.

A vector autoregressive model for electricity prices subject to long memory and regime switching

International Nuclear Information System (INIS)

Haldrup, Niels; Nielsen, Frank S.; Nielsen, Morten Oerregaard

2010-01-01

A regime dependent VAR model is suggested that allows long memory (fractional integration) in each of the observed regime states as well as the possibility of fractional cointegration. The model is motivated by the dynamics of electricity prices where the transmission of power is subject to occasional congestion periods. For a system of bilateral prices non-congestion means that electricity prices are identical whereas congestion makes prices depart. Hence, the joint price dynamics implies switching between a univariate price process under non-congestion and a bivariate price process under congestion. At the same time, it is an empirical regularity that electricity prices tend to show a high degree of long memory, and thus that prices may be fractionally cointegrated. Analysis of Nord Pool data shows that even though the prices are identical under non-congestion, the prices are not, in general, fractionally cointegrated in the congestion state. Hence, in most cases price convergence is a property following from regime switching rather than a conventional error correction mechanism. Finally, the suggested model is shown to deliver forecasts that are more precise compared to competing models. (author)

A Vector Autoregressive Model for Electricity Prices Subject to Long Memory and Regime Switching

DEFF Research Database (Denmark)

Haldrup, Niels; Nielsen, Frank; Nielsen, Morten Ørregaard

2007-01-01

A regime dependent VAR model is suggested that allows long memory (fractional integration) in each of the regime states as well as the possibility of fractional cointegra- tion. The model is relevant in describing the price dynamics of electricity prices where the transmission of power is subject...... to occasional congestion periods. For a system of bilat- eral prices non-congestion means that electricity prices are identical whereas congestion makes prices depart. Hence, the joint price dynamics implies switching between essen- tially a univariate price process under non-congestion and a bivariate price...

Congestion, air pollution, and road safety in urban areas

Energy Technology Data Exchange (ETDEWEB)

Shefer, Daniel [Department of Urban and Regional Economics and Transport, Technion-Israel Institute of Technology, Haifa (Israel)

1993-06-01

The continuous rapid growth in Vehicle Miles Travelled (VMT), coupled with the rapid increase in traffic congestion on highways of virtually every large urban area, explain a major portion of the observed deterioration of urban air quality. To halt this deterioration process and to secure safe and healthy environments and improve the quality of life in our cities, it is paramount to initiate and implement programs which jointly treat traffic congestion, air quality, and road safety. A host of market-based strategies, driven by price mechanisms, have been proposed as the best and most efficient way to decrease traffic congestion and to reduce vehicle emission. Congestion pricing, emission fees, reducing emissions of high polluting vehicles, and introducing more efficient vehicle and/or fuel technologies are not mutually exclusive strategies and therefore they can, and perhaps should, be employed jointly within an overall strategy. In view of the conflicting objectives which may exist between improving urban air quality and reducing road fatalities and traffic congestion, it is of great importance to thoroughly investigate these functional relationships. The results of such studies will help decision makers identify the `socially optimal level of congestion` which will yield the highest net social benefit. 2 figs., 43 refs.

Congestion management in a market environment. 2. CIGRE/PES Symposium

International Nuclear Information System (INIS)

2005-01-01

With the opening of electricity markets and changes in the power flows, the issue of available transmission capacity is of more and more importance. Market orientated answers and real-time solutions are implemented or under consideration; diligent management of existing assets and timely investment decisions to increase capacity and to improve the management systems are fundamental. This Symposium discusses the congestion management issue for internal and cross border exchanges, covering six subject areas: international Practices for Congestion Management, tariffs and Pricing, operations for Congestion, information Technology Issues, experiences with Congestion Management, tools for Congestion Management. (author)

Day-ahead tariffs for the alleviation of distribution grid congestion from electric vehicles

DEFF Research Database (Denmark)

O'Connell, Niamh; Wu, Qiuwei; Østergaard, Jacob

2012-01-01

An economically efficient day-ahead tariff (DT) is proposed with the purpose of preventing the distribution grid congestion resulting from electric vehicle (EV) charging scheduled on a dayahead basis. The DT concept developed herein is derived from the locational marginal price (LMP), in particular...... the congestion cost component of the LMP. A step-wise congestion management structure has been developed whereby the distribution system operator (DSO) predicts congestion for the coming day and publishes DTs prior to the clearing of the day-ahead market. EV fleet operators (FOs) optimize their EV charging...... schedules with respect to the predicted day-ahead prices and the published DTs, thereby avoiding congestion while still minimizing the charging cost. A Danish 400V distribution network is used to carry out case studies to illustrate the effectiveness of the developed concept for the prevention...

Benefits from coordinating congestion management-The Nordic power market

International Nuclear Information System (INIS)

Bjorndal, Mette; Joernsten, Kurt

2007-01-01

We consider the possibility of improving the utilization of the capacity of the Nordic transmission grid, by improving on the methods for congestion management. We use a simplified model of the Nordic power market, and different load-scenarios are developed in order to illustrate the effects. By improving the coordination of the system operator function, we may achieve that the actual bottlenecks, both as regards to the location and capacity, form the basis for the definition of price areas. This may result in a better partition of the grid, not necessarily following the borders between the control areas of today's system operators. We also consider solving intra zonal bottlenecks 'directly', through the area prices and 'indirectly' by 'moving' internal capacity constraints to the borders between price areas. The examples illustrate that this 'indirect' congestion management may be costly, and result in larger price differences than necessary

Economics : pricing, demand, and economic efficiency : a primer.

Science.gov (United States)

2008-11-01

The Congestion Pricing Primer Series is part of : FHWAs outreach efforts to introduce the various : aspects of congestion pricing to decision-makers and : transportation professionals in the United States. The : primers are intended to lay out the...

Efficiency and profit in the NYISO transmission congestion contract market

Energy Technology Data Exchange (ETDEWEB)

Hadsell, Lester; Shawky, Hany A.

2009-11-15

Evidence of speculator profit and TCC price less than congestion charges suggests that additional competition in the TCC auction should be encouraged as a way to increase efficiency and lower the price of this ''insurance'' for hedgers. (author)

Congestion management in the European electricity market; Engpassmanagement im Europaeischen Strommarkt

Energy Technology Data Exchange (ETDEWEB)

Dieckmann, Birgit

2008-11-24

The author of the contribution under consideration reports on an assessment of methods of congestion management employed in Europe with respect to their effectiveness and identify possible reasons for the misallocation of cross-border transmission capacity. For this, generation structures of European countries and the resulting prices and load flows are analysed. Different power plants and bottlenecks in the transmission network currently cause structural price differences due to a low degree of integration of European electricity markets. By means of congestion management, the formation of a uniform electricity market will be created.

Ramsey prices in the Italian electricity market

International Nuclear Information System (INIS)

Bigerna, Simona; Bollino, Carlo Andrea

2016-01-01

In this paper, we derive optimal zonal prices in the Italian day-ahead electricity market using estimation of a complete system of hourly demand in 2010–2011. In Italy, the hourly equilibrium price for all buyers is computed as a uniform average of supply zonal prices, resulting from market splitting due to line congestion. We model ex-ante individual bids expressed by heterogeneous consumers, which are distinguished by geographical zones. Using empirical estimations, we compute demand elasticity values and new zonal prices, according to a Ramsey optimal scheme. This is a new approach in the wholesale electricity market literature, as previous studies have discussed the relative merit of zonal prices, considering only the issue of line congestion. Our results show that the optimal pricing scheme can improve welfare in the day-ahead Italian electricity market, with respect to both the existing uniform price scheme and the proposal to charge the existing supply zonal prices to the demand side. - Highlights: • We model and estimate the demand of heterogeneous buyers in the electricity market. • Transmission line congestion creates welfare distortions in the market. • We derive optimal Ramsey prices in the Italian day-ahead electricity market. • We compare optimal prices with historical ones showing how to improve welfare.

Road pricing with complications

DEFF Research Database (Denmark)

Fosgerau, Mogens; Van Dender, Kurt

2013-01-01

The rationale for congestion charges is that by internalising the marginal external congestion cost, they restore efficiency in the transport market. In the canonical model underlying this view, congestion is a static phenomenon, users are taken to be homogenous, there is no travel time risk......, and a highly stylised model of congestion is used. The simple analysis also ignores that real pricing schemes are only rough approximations to ideal systems and that inefficiencies in related markets potentially affect the case for congestion charges. The canonical model tends to understate the marginal...... external congestion cost because it ignores user heterogeneity and trip timing inefficiencies. With respect to the relevance of interactions between congestion and congestion charges and tax distortions and distributional concerns, recent insights point out that there is no general case for modifying...

Indirect control of DSRs for regulating power provision and solving local congestions

DEFF Research Database (Denmark)

Sossan, Fabrizio; Marinelli, Mattia; Costanzo, Giuseppe Tommaso

2013-01-01

Inducing a shift in the electricity consumption using a broadcasted dynamic price for the energy is often proposed as a resource for providing regulating power and it is becoming an increasing research focus for enabling higher penetration of renewable energy in the current power system. This paper...... with the CIGRE’ MV reference network with 346 electrically heated buildings as Demand Side Resources, DSRs. The dynamic hourly price of the regulating power provided by Nord Pool Spot market has been used as indirect control signal for the flexible demand....... shows how using indirect control (or control by price) without any precautions, might easily lead to congestions in nearly saturated distribution grids. An auto tuning local controller which acts on the price signal at distribution level is proposed for solving the congestion. Simulations are performed...

Auctions for Congestion Management in Distribution Grids

NARCIS (Netherlands)

Philipsen, R.M.; de Weerdt, M.M.; de Vries, L.J.

2016-01-01

Large controllable loads, such as electric vehicles, are increasingly penetrating electricity distribution feeders. To avoid local congestion, their consumption behaviour must be steered, for which a real-time price propagated down from the transmission system does not suffice, as it does not

Essays in financial transmission rights pricing

Science.gov (United States)

Posner, Barry

This work examines issues in the pricing of financial transmission rights in the PJM market region. The US federal government is advocating the creation of large-scale, not-for-profit regional transmission organizations to increase the efficiency of the transmission of electricity. As a non-profit entity, PJM needs to allocate excess revenues collected as congestion rents, and the participants in the transmission markets need to be able to hedge their exposure to congestion rents. For these purposes, PJM has developed an instrument known as the financial transmission right (FTR). This research, utilizing a new data set assembled by the author, looks at two aspects of the FTR market. The first chapter examines the problem of forecasting congestion in a transmission grid. In the PJM FTR system firms bid in a competitive auction for FTRs that cover a period of one month. The auctions take place in the middle of the previous month; therefore firms have to forecast congestion rents for the period two to six weeks after the auction. The common methods of forecasting congestion are either time-series models or full-information engineering studies. In this research, the author develops a forecasting system that is more economically grounded than a simple time-series model, but requires less information than an engineering model. This method is based upon the arbitrage-cost methodology, whereby congesting is calculated as the difference of two non-observable variables: the transmission price difference that would exist in the total absence of transmission capacity between two nodes, and the ability of the existing transmission to reduced that price difference. If the ability to reduce the price difference is greater than the price difference, then the cost of electricity at each node will be the same, and congestion rent will be zero. If transmission capacity limits are binding on the flow of power, then a price difference persists and congestion rents exist. Three

Internet pricing: una breve rassegna critica (Internet Pricing: A Short Critical Survey

Directory of Open Access Journals (Sweden)

Claudio Sardoni

2001-03-01

Full Text Available In the article, some recent literature on Internet pricing is surveyed. The author looks at the topic by setting it in the more general framework of the analysis of activities that can be regarded as similar to Internet from the technological and economic point of view. In particular, attention is focused on the problem of the divergence between private and social costs when there occurs network congestion and the problem of efficient prices in activities characterized by the existence of peak-loads. The author argues that dealing with such issues in the context of Internet cannot be reduced to a straightforward application of traditional results of welfare economics and the literature on peak-load pricing. In a competitive market with similar features to the market for Internet services, it is well possible that there do not exist incentives that induce firms to adopt price systems such as to prevent and/or eliminate congestion. Further theoretical and analytical developments are then in order.

Airport Pricing Strategies

Science.gov (United States)

Pels, Eric; Verhoef, Erik T.

2003-01-01

Conventional economic wisdom suggests that congestion pricing would be an appropriate response to cope with the growing congestion levels currently experienced at many airports. Several characteristics of aviation markets, however, may make naive congestion prices equal to the value of marginal travel delays a non-optimal response. This paper has developed a model of airport pricing that captures a number of these features. The model in particular reflects that airlines typically have market power and are engaged in oligopolistic competition at different sub-markets; that part of external travel delays that aircraft impose are internal to an operator and hence should not be accounted for in congestion tolls. We presented an analytical treatment for a simple bi-nodal symmetric network, which through the use of 'hyper-networks' would be readily applicable to dynamic problems (in discrete time) such as peak - off-peak differences, and some numerical exercises for the same symmetric network, which was only designed to illustrate the possible comparative static impacts of tolling, in addition to marginal equilibrium conditions as could be derived for the general model specification. Some main conclusions are that second-best optimal tolls are typically lower than what would be suggested by congestion costs alone and may even be negative, and that the toll as derived by Brueckner (2002) may not lead to an increase in total welfare. While Brueckner (2002) has made clear that congestion tolls on airports may be smaller than expected when congestion costs among aircraft are internal for a firm, our analysis adds to this that a further downward adjustment may be in order due to market power. The presence of market power (which causes prices to exceed marginal costs) may cause the pure congestion toll to be suboptimal, because the resulting decrease in demand is too high (the pure congestion tall does not take into account the decrease in consumer surplus). The various

Rules for congestion management. Evaluation of available of capacity and possibilities for increased counter trade

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-08-01

In the Nordic electricity market, congestion is currently managed using two methods: a combination of price areas (market splitting) and counter-trade. In the planning phase (one day ahead) the main method employed is market splitting, although moving internal bottlenecks to the country border and domestic counter-trade are also used to some degree. Congestion is solved through counter- trade in the operating phase (during the day). In spring 2002, Nordel published a report with proposals for possible changes in Nordic congestion management. The main proposal was to introduce new price areas in the spot market and let the borders of price areas coincide with the physical borders of congestion in the transmission network to a greater degree. It was also proposed to increase the use of counter-trade. Based on feedback from Nordic market players, Nordel decided to carry on the work with congestion management in a new ad hoc group. The group's mandate was a Nordic harmonization of rules and practices for congestion management and a socio-economically efficient utilisation of the transmission grid capacity. Furthermore, the group was asked to investigate how to ensure optimal availability of capacity and to look into the possibilities of increasing usage of counter-trade. The ad hoc working group results are presented in this report. Among the conclusions drawn from the investigations are: 1) A limited increase of counter-trade in the planning phase is feasible for temporary congestion in order to reduce the area price risks for the market players, 2) Market participants should be consulted to get their views on whether and to what extent counter-trade should be increased taking benefits and costs into account. The extent of counter-trade could e.g. be decided as a percentage of NCT with intact grid, 3) Nordel should consider a practice where counter-trading is used to prevent reductions in cross-border capacity due to maintenance, 4) The use of counter-trade in

Rules for congestion management. Evaluation of availability of capacity and possibilities for increased counter trade

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-08-01

In the Nordic electricity market, congestion is currently managed using two methods: a combination of price areas (market splitting) and counter-trade. In the planning phase (one day ahead) the main method employed is market splitting, although moving internal bottlenecks to the country border and domestic counter-trade are also used to some degree. Congestion is solved through counter- trade in the operating phase (during the day). In spring 2002, Nordel published a report with proposals for possible changes in Nordic congestion management. The main proposal was to introduce new price areas in the spot market and let the borders of price areas coincide with the physical borders of congestion in the transmission network to a greater degree. It was also proposed to increase the use of counter-trade. Based on feedback from Nordic market players, Nordel decided to carry on the work with congestion management in a new ad hoc group. The group's mandate was a Nordic harmonization of rules and practices for congestion management and a socio-economically efficient utilisation of the transmission grid capacity. Furthermore, the group was asked to investigate how to ensure optimal availability of capacity and to look into the possibilities of increasing usage of counter-trade. The ad hoc working group results are presented in this report. Among the conclusions drawn from the investigations are: 1) A limited increase of counter-trade in the planning phase is feasible for temporary congestion in order to reduce the area price risks for the market players, 2) Market participants should be consulted to get their views on whether and to what extent counter-trade should be increased taking benefits and costs into account. The extent of counter-trade could e.g. be decided as a percentage of NCT with intact grid, 3) Nordel should consider a practice where counter-trading is used to prevent reductions in cross-border capacity due to maintenance, 4) The use of counter-trade in

Rules for congestion management. Evaluation of availability of capacity and possibilities for increased counter trade

International Nuclear Information System (INIS)

2004-08-01

In the Nordic electricity market, congestion is currently managed using two methods: a combination of price areas (market splitting) and counter-trade. In the planning phase (one day ahead) the main method employed is market splitting, although moving internal bottlenecks to the country border and domestic counter-trade are also used to some degree. Congestion is solved through counter- trade in the operating phase (during the day). In spring 2002, Nordel published a report with proposals for possible changes in Nordic congestion management. The main proposal was to introduce new price areas in the spot market and let the borders of price areas coincide with the physical borders of congestion in the transmission network to a greater degree. It was also proposed to increase the use of counter-trade. Based on feedback from Nordic market players, Nordel decided to carry on the work with congestion management in a new ad hoc group. The group's mandate was a Nordic harmonization of rules and practices for congestion management and a socio-economically efficient utilisation of the transmission grid capacity. Furthermore, the group was asked to investigate how to ensure optimal availability of capacity and to look into the possibilities of increasing usage of counter-trade. The ad hoc working group results are presented in this report. Among the conclusions drawn from the investigations are: 1) A limited increase of counter-trade in the planning phase is feasible for temporary congestion in order to reduce the area price risks for the market players, 2) Market participants should be consulted to get their views on whether and to what extent counter-trade should be increased taking benefits and costs into account. The extent of counter-trade could e.g. be decided as a percentage of NCT with intact grid, 3) Nordel should consider a practice where counter-trading is used to prevent reductions in cross-border capacity due to maintenance, 4) The use of counter-trade in the

Electricity market pricing, risk hedging and modeling

Science.gov (United States)

Cheng, Xu

In this dissertation, we investigate the pricing, price risk hedging/arbitrage, and simplified system modeling for a centralized LMP-based electricity market. In an LMP-based market model, the full AC power flow model and the DC power flow model are most widely used to represent the transmission system. We investigate the differences of dispatching results, congestion pattern, and LMPs for the two power flow models. An appropriate LMP decomposition scheme to quantify the marginal costs of the congestion and real power losses is critical for the implementation of financial risk hedging markets. However, the traditional LMP decomposition heavily depends on the slack bus selection. In this dissertation we propose a slack-independent scheme to break LMP down into energy, congestion, and marginal loss components by analyzing the actual marginal cost of each bus at the optimal solution point. The physical and economic meanings of the marginal effect at each bus provide accurate price information for both congestion and losses, and thus the slack-dependency of the traditional scheme is eliminated. With electricity priced at the margin instead of the average value, the market operator typically collects more revenue from power sellers than that paid to power buyers. According to the LMP decomposition results, the revenue surplus is then divided into two parts: congestion charge surplus and marginal loss revenue surplus. We apply the LMP decomposition results to the financial tools, such as financial transmission right (FTR) and loss hedging right (LHR), which have been introduced to hedge against price risks associated to congestion and losses, to construct a full price risk hedging portfolio. The two-settlement market structure and the introduction of financial tools inevitably create market manipulation opportunities. We investigate several possible market manipulation behaviors by virtual bidding and propose a market monitor approach to identify and quantify such

Electricity transmission congestion costs: A review of recent reports

Energy Technology Data Exchange (ETDEWEB)

Lesieutre, Bernard C.; Eto, Joseph H.

2003-10-01

Recently, independent system operators (ISOs) and others have published reports on the costs of transmission congestion. The magnitude of congestion costs cited in these reports has contributed to the national discussion on the current state of U.S. electricity transmission system and whether it provides an adequate platform for competition in wholesale electricity markets. This report reviews reports of congestion costs and begins to assess their implications for the current national discussion on the importance of the U.S. electricity transmission system for enabling competitive wholesale electricity markets. As a guiding principle, we posit that a more robust electricity system could reduce congestion costs; and thereby, (1) facilitate more vibrant and fair competition in wholesale electricity markets, and (2) enable consumers to seek out the lowest prices for electricity. Yet, examining the details suggests that, sometimes, there will be trade-offs between these goals. Therefore, it is essential to understand who pays, how much, and how do they benefit in evaluating options (both transmission and non-transmission alternatives) to address transmission congestion. To describe the differences among published estimates of congestion costs, we develop and motivate three ways by which transmission congestion costs are calculated in restructured markets. The assessment demonstrates that published transmission congestion costs are not directly comparable because they have been developed to serve different purposes. More importantly, critical information needed to make them more comparable, for example in order to evaluate the impacts of options to relieve congestion, is sometimes not available.

A duopoly model with heterogeneous congestion-sensitive customers

NARCIS (Netherlands)

Mandjes, M.R.H.; Timmer, Judith B.

2003-01-01

This paper analyzes a model with multiple firms (providers), and two classes of customers. These customers classes are characterized by their attitude towards `congestion' (caused by other customers using the same resources); a firm is selected on the basis of both the prices charged by the firms,

434 Urban Traffic Congestion and Its Attendant Health Effects on ...

African Journals Online (AJOL)

User

2010-10-17

Oct 17, 2010 ... Keywords: Congestion, Effects, Health, Road Traffic, and Road Users. ..... of transport problems that can be identified are: bad roads, fuel problem (high fuel price .... Cities.www.ghanaweb.com/ghanahomepage/news archive.

Nonlinear road pricing for congestion and the environment.

Science.gov (United States)

2012-03-30

Under nonlinear road pricing (or tolling), the price charged is not strictly proportional to the distance travelled inside a tolling area, the generalized travel cost is not link-wise additive, and finding a user equilibrium distribution is typically...

Internet pricing: una breve rassegna critica (Internet Pricing: A Short Critical Survey

Directory of Open Access Journals (Sweden)

Claudio Sardoni

2012-04-01

Full Text Available In the article, some recent literature on Internet pricing is surveyed. The author looks at the topic by setting it in the more general framework of the analysis of activities that can be regarded as similar to Internet from the technological and economic point of view. In particular, attention is focused on the problem of the divergence between private and social costs when there occurs network congestion and the problem of efficient prices in activities characterized by the existence of peak-loads. The author argues that dealing with such issues in the context of Internet cannot be reduced to a straightforward application of traditional results of welfare economics and the literature on peak-load pricing. In a competitive market with similar features to the market for Internet services, it is well possible that there do not exist incentives that induce firms to adopt price systems such as to prevent and/or eliminate congestion. Further theoretical and analytical developments are then in order.  JEL Codes: L86, L11Keywords: Pricing

Dynamic Power Tariff for Congestion Management in Distribution Networks

DEFF Research Database (Denmark)

Huang, Shaojun; Wu, Qiuwei; Shahidehpour, Mohammad

2018-01-01

This paper proposes dynamic power tariff (DPT), a new concept for congestion management in distribution networks with high penetration of electric vehicles (EVs), and heat pumps (HPs). The DPT concept is proposed to overcome a drawback of the dynamic tariff (DT) method, i.e., DPT can replace...... the price sensitivity parameter in the DT method, which is relatively unrealistic in practice. Based on the control theory, a control model with two control loops, i.e., the power flow control and voltage control, is established to analyze the congestion management process by the DPT method. Furthermore...

Pricing by timing: innovating broadband data plans

Science.gov (United States)

Ha, Sangtae; Joe-Wong, Carlee; Sen, Soumya; Chiang, Mung

2012-01-01

Wireless Internet usage is doubling every year. Users are using more of high bandwidth data applications, and the heavy usage concentrates on several peak hours in a day, forcing ISPs to overprovision their networks accordingly. In order to remain profitable, ISPs have been using pricing as a congestion management tool. We review many of such pricing schemes in practice today and argue that they do not solve ISPs' problem of growing data traffic. We believe that dynamic, time-dependent usage pricing, which charges users based on when they access the Internet, can incentivize users to spread out their bandwidth consumption more evenly across different times of the day, thus helping ISPs to overcome the problem of peak congestion. Congestion pricing is not a new idea in itself, but the time for its implementation in data networks has finally arrived. Our key contribution lies in developing new analysis and a fully integrated system architecture, called TUBE (Time-dependent Usage-based Broadband price Engineering) that enables ISPs to implement the proposed TDP plan. The theory, simulation, and system implementation of TUBE system is further complemented with consumer surveys conducted in India and the US, along with preparations for a field trial that is currently underway.

Pricing methodologies for congestion management in a deregulated ...

African Journals Online (AJOL)

The key factors involved in the pricing of energy identified till now are network security, reliability, transmission losses allocation, technical, and social issues. This bibliographical survey was an attempt towards summarizing the recognized works and publications oriented towards pricing of electricity market. The purpose of ...

Congestion management in power systems. Long-term modeling framework and large-scale application

Energy Technology Data Exchange (ETDEWEB)

Bertsch, Joachim; Hagspiel, Simeon; Just, Lisa

2015-06-15

In liberalized power systems, generation and transmission services are unbundled, but remain tightly interlinked. Congestion management in the transmission network is of crucial importance for the efficiency of these inter-linkages. Different regulatory designs have been suggested, analyzed and followed, such as uniform zonal pricing with redispatch or nodal pricing. However, the literature has either focused on the short-term efficiency of congestion management or specific issues of timing investments. In contrast, this paper presents a generalized and flexible economic modeling framework based on a decomposed inter-temporal equilibrium model including generation, transmission, as well as their inter-linkages. Short and long-term effects of different congestion management designs can hence be analyzed. Specifically, we are able to identify and isolate implicit frictions and sources of inefficiencies in the different regulatory designs, and to provide a comparative analysis including a benchmark against a first-best welfare-optimal result. To demonstrate the applicability of our framework, we calibrate and numerically solve our model for a detailed representation of the Central Western European (CWE) region, consisting of 70 nodes and 174 power lines. Analyzing six different congestion management designs until 2030, we show that compared to the first-best benchmark, i.e., nodal pricing, inefficiencies of up to 4.6% arise. Inefficiencies are mainly driven by the approach of determining cross-border capacities as well as the coordination of transmission system operators' activities.

Port pricing : principles, structure and models

OpenAIRE

Meersman, Hilde; Strandenes, Siri Pettersen; Van de Voorde, Eddy

2014-01-01

Price level and price transparency are input to shippers’ choice of supply chain and transport mode. In this paper, we analyse current port pricing structures in the light of the pricing literature and consider opportunities for improvement. We present a detailed overview of pricing criteria, who sets prices and who ultimately foots the bill for port-of-call charges, cargo-handling fees and congestion charges. Current port pricing practice is based on a rather linear structure and fails to in...

Hybrid Pricing in a Coupled European Power Market with More Wind Power

OpenAIRE

Bjørndal, Endre; Bjørndal, Mette; Cai, Hong; Panos, Evangelos

2015-01-01

In the European market, the promotion of wind power leads to more network congestion. Zonal pricing (market coupling), which does not take the physical characteristics of transmission into account, is the most commonly used method to relieve congestion in Europe. Zonal pricing fails to provide adequate locational price signals regarding the energy resource scarcity and thus creates a large amount of unscheduled cross-border flows originating from wind-generated power, making the interconne...

Locational price spreads and the pricing of contracts for difference. Evidence from the Nordic market

International Nuclear Information System (INIS)

Marckhoff, Jan; Wimschulte, Jens

2009-01-01

In electricity markets, not only does the risk of substantial price variations over time exist, but so does the risk of price variations over space, as prices between locations can differ due to transmission congestion. To manage this risk, Contracts for Difference (CfDs), i.e., forwards on the spread between a particular area price and the (unconstrained) system price, were introduced at the Scandinavian electricity exchange Nord Pool at the end of 2000. We empirically investigate the pricing of these CfDs over the period 2001 through 2006 and find that CfD prices contain significant risk premia. Their sign and magnitude, however, differ substantially between areas and delivery periods, because areas are subject to transmission congestion to a varying extent. While the relation between risk premia and time-to-maturity is not uniform for CfDs, there is a negative relation for implied area and system forwards, which can be explained by the relative hedging demand of market participants. In addition, we find that risk premia of CfDs and implied area forwards vary systematically with the variance and skewness of the underlying spot prices. This confirms both implications of the Bessembinder and Lemmon [Bessembinder, H., Lemmon, M.L., 2002. Equilibrium pricing and optimal hedging in electricity forward markets. Journal of Finance, 57, 1347-1382] model. (author)

The asymptotic price of anarchy for k-uniform congestion games

NARCIS (Netherlands)

de Jong, Jasper; Kern, Walter; Steenhuisen, Berend; Uetz, Marc; Solis-Oba, Roberto

2018-01-01

We consider the atomic version of congestion games with affine cost functions, and analyze the quality of worst case Nash equilibria when the strategy spaces of the players are the set of bases of a k-uniform matroid. In this setting, for some parameter k, each player is to choose k out of a finite

Dynamic Subsidy Method for Congestion Management in Distribution Networks

DEFF Research Database (Denmark)

Huang, Shaojun; Wu, Qiuwei

2016-01-01

Dynamic subsidy (DS) is a locational price paid by the distribution system operator (DSO) to its customers in order to shift energy consumption to designated hours and nodes. It is promising for demand side management and congestion management. This paper proposes a new DS method for congestion...... management in distribution networks, including the market mechanism, the mathematical formulation through a two-level optimization, and the method solving the optimization by tightening the constraints and linearization. Case studies were conducted with a one node system and the Bus 4 distribution network...... of the Roy Billinton Test System (RBTS) with high penetration of electric vehicles (EVs) and heat pumps (HPs). The case studies demonstrate the efficacy of the DS method for congestion management in distribution networks. Studies in this paper show that the DS method offers the customers a fair opportunity...

On the Inefficiency of Equilibria in Linear Bottleneck Congestion Games

Science.gov (United States)

de Keijzer, Bart; Schäfer, Guido; Telelis, Orestis A.

We study the inefficiency of equilibrium outcomes in bottleneck congestion games. These games model situations in which strategic players compete for a limited number of facilities. Each player allocates his weight to a (feasible) subset of the facilities with the goal to minimize the maximum (weight-dependent) latency that he experiences on any of these facilities. We derive upper and (asymptotically) matching lower bounds on the (strong) price of anarchy of linear bottleneck congestion games for a natural load balancing social cost objective (i.e., minimize the maximum latency of a facility). We restrict our studies to linear latency functions. Linear bottleneck congestion games still constitute a rich class of games and generalize, for example, load balancing games with identical or uniformly related machines with or without restricted assignments.

Recent developments and current policy issues in road pricing in the US and Canada

OpenAIRE

Lindsey, Robin

2005-01-01

The United States and Canada lag Europe and Singapore in implementing road pricing on a large scale. But the two countries have shown interest in tolling roads as a way to curb congestion and to generate revenues. The US is funding congestion pricing demonstration projects through its Value Pricing Pilot Program, and Canada has examined new ways to charge for road use and to finance road construction and maintenance. This paper reviews the current state of road pricing and funding...

Nodal pricing in a coupled electricity market

OpenAIRE

Bjørndal, Endre; Bjørndal, Mette; Cai, Hong

2014-01-01

This paper investigates a pricing model for an electricity market with a hybrid congestion management method, i.e. part of the system applies a nodal pricing scheme and the rest applies a zonal pricing scheme. The model clears the zonal and nodal pricing areas simultaneously. The nodal pricing area is affected by the changes in the zonal pricing area since it is directly connected to the zonal pricing area by commercial trading. The model is tested on a 13-node power system. Within the area t...

Flow-based market coupling. Stepping stone towards nodal pricing?

International Nuclear Information System (INIS)

Van der Welle, A.J.

2012-07-01

For achieving one internal energy market for electricity by 2014, market coupling is deployed to integrate national markets into regional markets and ultimately one European electricity market. The extent to which markets can be coupled depends on the available transmission capacities between countries. Since interconnections are congested from time to time, congestion management methods are deployed to divide the scarce available transmission capacities over market participants. For further optimization of the use of available transmission capacities while maintaining current security of supply levels, flow-based market coupling (FBMC) will be implemented in the CWE region by 2013. Although this is an important step forward, important hurdles for efficient congestion management remain. Hence, flow based market coupling is compared to nodal pricing, which is often considered as the most optimal solution from theoretical perspective. In the context of decarbonised power systems it is concluded that advantages of nodal pricing are likely to exceed its disadvantages, warranting further development of FBMC in the direction of nodal pricing.

A uniform price auction with locational price adjustments for competitive electricity markets

International Nuclear Information System (INIS)

Ethier, R.; Mount, T.; Schulze, W.; Zimmerman, R.; Thomas, R.

1999-01-01

Competitive electricity markets which rely on centralized dispatch require a mechanism to solicit offers from competing generators. Ideally, such an auction mechanism, provides incentives to submit offers equal to the marginal cost of generation for each generator. Economic theory suggests that the Uniform Price auction is an appropriate institution. However, an efficient implementation of this auction in an electricity context requires that the offers used in the auction reflect the appropriate locational price adjustments for transmission losses and congestion. This paper describes a uniform price auction that incorporates locational price adjustments on a Web-based platform suitable for experimentation. Preliminary results show dramatically different price and revenue results when compared with a simple continuous Discriminative auction. (author)

Battling gridlock : congestion fees are working in Europe and Asia, but its questionable if they will succeed in car-crazy North America

Energy Technology Data Exchange (ETDEWEB)

Carnevale, R. [Colleges Integrating Immigrants to Employment, Toronto, ON (Canada); Crawford, E.A. [York Univ., Toronto, ON (Canada). Faculty of Environmental Studies

2008-07-01

This article described different traffic congestion schemes that cities around the world have adopted to ease traffic grid-lock. Congestion fees that discourage road use involve assigning a price to a road based on the demand for using that road. A weekday congestion fee which was imposed on drivers in the city of London in 2003 resulted in a 30 per cent drop in vehicular traffic in the city centre. The pricing structure was independent of vehicle type, distance travelled or time of day. The successful scheme is credited with an increase in cycling and public transit ridership as well as a decrease in accidents and air pollution without hindering business within the congestion zone. However, the effectiveness of congestion fees in North America is questionable. Although San Diego's high-occupancy toll lanes have helped reduce congestion and pollution because the revenue raised is invested in public transportation, objections have been raised regarding plans to implement congestion fees in San Francisco and New York city centres because doing so would prevent those with low incomes from driving in the city. London has responded to such challenges by putting all net revenues derived from the fees back into public transportation. Similar measures were taken in Stockholm, Sweden where massive improvements were made to its transit system prior to introducing congestion fees to avert criticism. In order for congestion fees to be effective and gain public approval, there should be clear objectives that include demand management, good transportation alternatives, revenues that go to public transit and a simple pricing system that uses proven technology. The cumulative annual cost of congestion in 9 urban centres in Canada ranged from $2.3 billion to $3.7 billion in 2002 according to Transport Canada. Analysts have cautioned that congestion schemes would be difficult to duplicate in North American cities that are highly dependent on automobiles. However, the authors

Battling gridlock : congestion fees are working in Europe and Asia, but its questionable if they will succeed in car-crazy North America

International Nuclear Information System (INIS)

Carnevale, R.; Crawford, E.A.

2008-01-01

This article described different traffic congestion schemes that cities around the world have adopted to ease traffic grid-lock. Congestion fees that discourage road use involve assigning a price to a road based on the demand for using that road. A weekday congestion fee which was imposed on drivers in the city of London in 2003 resulted in a 30 per cent drop in vehicular traffic in the city centre. The pricing structure was independent of vehicle type, distance travelled or time of day. The successful scheme is credited with an increase in cycling and public transit ridership as well as a decrease in accidents and air pollution without hindering business within the congestion zone. However, the effectiveness of congestion fees in North America is questionable. Although San Diego's high-occupancy toll lanes have helped reduce congestion and pollution because the revenue raised is invested in public transportation, objections have been raised regarding plans to implement congestion fees in San Francisco and New York city centres because doing so would prevent those with low incomes from driving in the city. London has responded to such challenges by putting all net revenues derived from the fees back into public transportation. Similar measures were taken in Stockholm, Sweden where massive improvements were made to its transit system prior to introducing congestion fees to avert criticism. In order for congestion fees to be effective and gain public approval, there should be clear objectives that include demand management, good transportation alternatives, revenues that go to public transit and a simple pricing system that uses proven technology. The cumulative annual cost of congestion in 9 urban centres in Canada ranged from $2.3 billion to $3.7 billion in 2002 according to Transport Canada. Analysts have cautioned that congestion schemes would be difficult to duplicate in North American cities that are highly dependent on automobiles. However, the authors

The dynamics of urban traffic congestion and the price of parking

DEFF Research Database (Denmark)

Fosgerau, Mogens; de Palma, André

2013-01-01

We consider commuting in a congested urban area. While an efficient time-varying toll may eliminate queuing, a toll may not be politically feasible. We study the benefit of a substitute: a parking fee at the workplace. An optimal time-varying parking fee is charged at zero rate when there is queu...

Uncertainty Management of Dynamic Tariff Method for Congestion Management in Distribution Networks

DEFF Research Database (Denmark)

Huang, Shaojun; Wu, Qiuwei; Cheng, Lin

2016-01-01

The dynamic tariff (DT) method is designed for the distribution system operator (DSO) to alleviate congestions that might occur in a distribution network with high penetration of distributed energy resources (DERs). Uncertainty management is required for the decentralized DT method because the DT...... is de- termined based on optimal day-ahead energy planning with forecasted parameters such as day-ahead energy prices and en- ergy needs which might be different from the parameters used by aggregators. The uncertainty management is to quantify and mitigate the risk of the congestion when employing...

Policy implementation lessons from six road pricing cases

NARCIS (Netherlands)

Vonk Noordegraaf, D.; Annema, J.A.; Wee, B. van

2014-01-01

The implementation of road pricing has been limited worldwide despite the notion that road pricing is generally considered to be a potentially effective measure to reduce externalities, in particular traffic congestion. By means of a content analysis of 106 scientific papers, this paper aims to

Wind power development in the United States: Effects of policies and electricity transmission congestion

Science.gov (United States)

Hitaj, Claudia

In this dissertation, I analyze the drivers of wind power development in the United States as well as the relationship between renewable power plant location and transmission congestion and emissions levels. I first examine the role of government renewable energy incentives and access to the electricity grid on investment in wind power plants across counties from 1998-2007. The results indicate that the federal production tax credit, state-level sales tax credit and production incentives play an important role in promoting wind power. In addition, higher wind power penetration levels can be achieved by bringing more parts of the electricity transmission grid under independent system operator regulation. I conclude that state and federal government policies play a significant role in wind power development both by providing financial support and by improving physical and procedural access to the electricity grid. Second, I examine the effect of renewable power plant location on electricity transmission congestion levels and system-wide emissions levels in a theoretical model and a simulation study. A new renewable plant takes the effect of congestion on its own output into account, but ignores the effect of its marginal contribution to congestion on output from existing plants, which results in curtailment of renewable power. Though pricing congestion removes the externality and reduces curtailment, I find that in the absence of a price on emissions, pricing congestion may in some cases actually increase system-wide emissions. The final part of my dissertation deals with an econometric issue that emerged from the empirical analysis of the drivers of wind power. I study the effect of the degree of censoring on random-effects Tobit estimates in finite sample with a particular focus on severe censoring, when the percentage of uncensored observations reaches 1 to 5 percent. The results show that the Tobit model performs well even at 5 percent uncensored observations

On revenue recycling and the welfare effects of second-best congestion pricing in a monocentric city

NARCIS (Netherlands)

Tikoudis, I.; Verhoef, E.T.; van Ommeren, J.N.

2015-01-01

This paper examines congestion taxes in a monocentric city with pre-existing labor taxation. When road toll revenue is used to finance labor tax cuts, 35% of the optimal road tax in our numerical model does not reflect marginal external congestion costs, but rather functions as a Ramsey-Mirrlees

Location matters: The impact of renewable power on transmission congestion and emissions

International Nuclear Information System (INIS)

Hitaj, Claudia

2015-01-01

Many governments offer subsidies for renewable power to reduce greenhouse gas emissions in the power sector. However, most support schemes for renewable power do not take into account that emissions depend on the location of renewable and conventional power plants within an electricity grid. I simulate optimal power flow in a test grid when 4 renewable power plants connect to the grid across 24 potential sites, amounting to over 10,000 configurations. Each configuration is associated with different levels of emissions and renewable power output. I find that emission reductions vary by a factor of 7 and that curtailment due to transmission congestion is more likely when renewable power plants are concentrated in an area of the grid with low demand. Large cost savings could be obtained by allowing subsidies for renewable power to vary across locations according to abatement potential or by replacing subsidies with a price on emissions. - Highlights: • Analyze the impact of renewable power plant location on congestion and emissions. • Simulate optimal power flow in a test grid for over 10,000 configurations. • Determine that emission reductions vary by a factor of 7. • Find that renewable power is curtailed due to transmission congestion. • Pricing emissions is most efficient since abatement potential varies across locations.

Generator Rescheduling under Congested Power System with Wind Integrated Competitive Power Market

Directory of Open Access Journals (Sweden)

Sadhan Gope

2017-02-01

Full Text Available Integration of renewable energy like wind or solar energy creates a huge pressure to the system operator (SO to ensure the congestion free transmission network under deregulated power market. Congestion Management (CM with integration of wind farm in double auction electricity market are described in this work to minimize fuel cost, system losses and locational marginal price (LMP of the system. Location of Wind Farm (WF is identified based by using Bus sensitivity factor (BSF, which is also used for selection of load bus for double auction bidding (DAB. The impacts of wind farm in congested power system under deregulated environment have been investigated in this work. Modified 39-bus New England test system is used for demonstrate the effectiveness of the presented approach by using Sequential Quadratic Programming (SQP.

Road pricing policy implementation

NARCIS (Netherlands)

Vonk Noordegraaf, D.M.

2016-01-01

Urban areas suffer from the negative externalities of road transport like congested road networks, air pollution and road traffic accidents. A measure to reduce these negative externalities is road pricing, meaning policies that impose direct charges on road use (Jones and Hervik, 1992). Since the

Access pricing on gas networks and capacity release markets: Lessons from North American and European experiences

International Nuclear Information System (INIS)

David, L.; Percebois, J.

2004-01-01

An evaluation of different access fee systems in North America and Europe in relation to normative prices is discussed. Among available alternatives the entry-exit pricing system as it is currently applied in the United Kingdom, the Netherlands, Italy and France, was judged to be the best solution to increased competition. Canadian and American experiences highlight the influence of the market power of shippers with regard to the efficacy of capping the market. Whether or not to cap the price on a capacity release market is a choice between the protection of shippers against market abuses and the promotion of secondary market liquidity, a choice that is linked to the level of congestion of a pipeline system. If there is much congestion, a price cap may be necessary; if there is little congestion, the need for market value given by an uncapped price may be more important than the market power of shippers. 15 refs., 2 tabs

Transmission economic expansion and congestion relief : a case study

Energy Technology Data Exchange (ETDEWEB)

Chao, H.; Trinh, L.H.; Moore, M. [ABB Consulting, Raleigh, NC (United States); Brown, L.; Patel, K. [SDG and E, San Diego, CA (United States)

2006-07-01

Transmission capacity additions have lagged behind load growth and generation expansion in the United States. This paper provided an economic analysis of various transmission upgrade options designed to address anticipated congestion of the electricity grid. A market-based transmission planning method was used to assess the economics of transmission expansion. The analysis accounted for the minimum costs of generation dispatch to satisfy transmission constraints, as well as a locational marginal price for each bus in the system. Marginal congestion costs for all major transmission facilities were monitored and recorded. Hourly simulations of load, generation, and transmission system interactions were conducted. Contract costs and economic measures were then calculated for each scenario run. A case study for the Sunrise Powerlink project was used to demonstrate the efficacy of the method. The study demonstrated that the Sunrise Powerlink project will eliminate significant congestion in California load centers. Results also showed that the analytical method provided critical information for decision-makers in weighing the costs with benefits for transmission projects. 5 refs., 2 tabs., 1 fig.

Intermittent renewable generation and network congestion: an empirical analysis of Italian Power Market

International Nuclear Information System (INIS)

Ardian, Faddy; Concettini, Silvia; Creti, Anna

2015-01-01

The literature demonstrates the likely reduction of wholesale electricity prices due to a larger penetration of renewable energy sources (RES). When markets are organized as two or more inter-connected sub-markets within a larger power market the final impact of increasing RES production may be less straightforward given the presence of network constraints. We tests this phenomenon by analyzing the impact of RES production on the probability of congestion and on the size of congestion cost in Italy. Using a database with hourly observations for a five year period we estimate two econometric models on five zonal pairings: a multinomial logit model for the occurrence and direction of congestion and a three stage least square model for the size of congestion costs. The analysis suggests that the effect of a larger local wind and solar supply is to decrease the probability of suffering congestion in entry and to increase the probability of causing a congestion in exit compared to no congestion case. Increasing hydroelectric production has a similar effect. These results hold for both importing and exporting regions, but importing regions are less likely to cause congestion in exit, therefore the installation of new RES capacity in these zones may have a positive effects in terms of flow balance between regions. Concerning the cost level, a larger local RES supply seems to push the congestion cost towards negative values as it decreases the marginal cost for balancing the system. This is true for all zones in the case of explicit congestion cost, but it is only verified in importing regions in the case of implicit congestion cost. This result suggests that the increase of RES production should be promoted in importing zones, but the overall growth should be controlled in order to avoid congestion in the opposite direction. (authors)

Internet Congestion Control System

Directory of Open Access Journals (Sweden)

Pranoto Rusmin

2010-10-01

Full Text Available Internet congestion occurs when resource demands exceeds the network capacity. But, it is not the only reason. Congestion can happen on some users because some others user has higher sending rate. Then some users with lower sending rate will experience congestion. This partial congestion is caused by inexactly feedback. At this moment congestion are solved by the involvement of two controlling mechanisms. These mechanisms are flow/congestion control in the TCP source and Active Queue Management (AQM in the router. AQM will provide feedback to the source a kind of indication for the occurrence of the congestion in the router, whereas the source will adapt the sending rate appropriate with the feedback. These mechanisms are not enough to solve internet congestion problem completely. Therefore, this paper will explain internet congestion causes, weakness, and congestion control technique that researchers have been developed. To describe congestion system mechanisms and responses, the system will be simulated by Matlab.

Internet congestion control

CERN Document Server

Varma, Subir

2015-01-01

Internet Congestion Control provides a description of some of the most important topics in the area of congestion control in computer networks, with special emphasis on the analytical modeling of congestion control algorithms. The field of congestion control has seen many notable advances in recent years and the purpose of this book, which is targeted towards the advanced and intermediate reader, is to inform about the most important developments in this area. The book should enable the reader to gain a good understanding of the application of congestion control theory to a number of applic

Review of Congestion Management Methods for Distribution Networks with High Penetration of Distributed Energy Resources

DEFF Research Database (Denmark)

Huang, Shaojun; Wu, Qiuwei; Liu, Zhaoxi

2014-01-01

This paper reviews the existing congestion management methods for distribution networks with high penetration of DERs documented in the recent research literatures. The congestion management methods for distribution networks reviewed can be grouped into two categories – market methods and direct...... control methods. The market methods consist of dynamic tariff, distribution capacity market, shadow price and flexible service market. The direct control methods are comprised of network reconfiguration, reactive power control and active power control. Based on the review of the existing methods...

Urban partnership agreement and congestion reduction demonstration programs : lessons learned on congestion pricing from the Seattle and Atlanta household travel behavior surveys.

Science.gov (United States)

2014-04-01

This paper presents lessons learned from household traveler surveys administered in Seattle and Atlanta as part of the evaluation of the Urban Partnership Agreement and Congestion Reduction Demonstration Programs. The surveys use a two-stage panel su...

Value pricing pilot program : lessons learned

Science.gov (United States)

2008-08-01

This "Lessons Learned Report" provides a summary of projects sponsored by the Federal Highway Administration's (FHWA's) Congestion and Value Pricing Pilot Programs from 1991 through 2006 and draws lessons from a sample of projects with the richest an...

Platform pricing in matching markets

NARCIS (Netherlands)

Goos, M.; van Cayseele, P.; Willekens, B.

2011-01-01

This paper develops a simple model of monopoly platform pricing accounting for two pertinent features of matching markets. 1) The trading process is characterized by search and matching frictions implying limits to positive cross-side network effects and the presence of own-side congestion.

Electricity transmission pricing. How contracts must reflect costs

International Nuclear Information System (INIS)

Shuttleworth, G.

1996-01-01

Two basic structures of transmission systems are distinguished: transmission channels offered through an integrated electric utility and open access offered over an independent network. The first structure allows the application of 'top-down pricing', where transmission prices are derived from customer tariffs less avoidable generation costs. Transmission prices in the second structure must be derived from a 'bottom-up' analysis of transmission costs, including building capacity, marginal losses, and congestion. 5 refs

Auctionable fixed transmission rights for congestion management

Science.gov (United States)

Alomoush, Muwaffaq Irsheid

Electric power deregulation has proposed a major change to the regulated utility monopoly. The change manifests the main part of engineers' efforts to reshape three components of today's regulated monopoly: generation, distribution and transmission. In this open access deregulated power market, transmission network plays a major role, and transmission congestion is a major problem that requires further consideration especially when inter-zonal/intra-zonal scheme is implemented. Declaring that engineering studies and experience are the criteria to define zonal boundaries or defining a zone based on the fact that a zone is a densely interconnected area (lake) and paths connecting these densely interconnected areas are inter-zonal lines will render insufficient and fuzzy definitions. Moreover, a congestion problem formulation should take into consideration interactions between intra-zonal and inter-zonal flows and their effects on power systems. In this thesis, we introduce a procedure for minimizing the number of adjustments of preferred schedules to alleviate congestion and apply control schemes to minimize interactions between zones. In addition, we give the zone definition a certain criterion based on the Locational Marginal Price (LMP). This concept will be used to define congestion zonal boundaries and to decide whether any zone should be merged with another zone or split into new zones. The thesis presents a unified scheme that combines zonal and FTR schemes to manage congestion. This combined scheme is utilized with LMPs to define zonal boundaries more appropriately. The presented scheme gains the best features of the FTR scheme, which are providing financial certainty, maximizing the efficient use of the system and making users pay for the actual use of congested paths. LMPs may give an indication of the impact of wheeling transactions, and calculations of and comparisons of LMPs with and without wheeling transactions should be adequate criteria to approve

Pricing methodologies for congestion management in a deregulated ...

African Journals Online (AJOL)

DR OKE

new facilities into the existing system and the long term firm transactions. ... view. The probabilistic approach has been applied in [73-77] to OPF to compute the locational marginal pricing. ... smaller and provides a reduced incentive for investment when installed reserves are above the target. .... contingencies," IEEE Trans.

A dynamic feedback-control toll pricing methodology : a case study on Interstate 95 managed lanes.

Science.gov (United States)

2013-06-01

Recently, congestion pricing emerged as a cost-effective and efficient strategy to mitigate the congestion problem on freeways. This study develops a feedback-control based dynamic toll approach to formulate and solve for optimal tolls. The study com...

Dynamic analysis of energy, environment and congestion effects of urban transport policy. Variabilisation of car taxation

Energy Technology Data Exchange (ETDEWEB)

Dender, K Van [Center for Economic Studies (Belgium)

1996-12-01

Road transport is an important cause of external costs. In general three types of external costs can be distinguished: congestion, air and noise pollution causing environment damage and health hazards, and road accidents. Policy measures aiming at the reduction of external costs mostly are limited to a specific cost-type. The lack of integration of policies causes inefficiencies, because external costs are strongly interlinked. In Ochelen and Proost, congestion, pollution and road accidents are treated as externalities. An optimal pricing and regulation policy for transport is calculated for Brussels in 2005. Regulation consists of prescriptions to car producers concerning the environmental characteristics of car-technology. Optimal prices charge transport users the social cost of their trips, with possibly a correction for the marginal cost of public funds. In a perfect pricing policy, prices would be differentiated according to conditions of congestion and pollution at each moment in time. The model is flexible enough to simulate the effects of more realistic policy packages. This flexibility has its cost in terms of degree of detail of the model. This paper deals with an extension of the Ochelen and Proost model, in two directions. The model is currently still a prototype. We concentrate on the main issues involved in making the model dynamic. The degree of detail therefore is rather limited. Magnitudes of policy effects must be interpreted carefully. We are more confident as to what concerns the directions of the effects. The paper first deals with the methodology of the model, calibration of the model and on the base case scenario, which serves as reference cases for the policy evaluation. (EG)

Strategic Generation with Conjectured Transmission Price Responses in a Mixed Transmission Pricing System. Part 2. Application

International Nuclear Information System (INIS)

Wals, A.F.; Hobbs, B.F.; Rijkers, F.A.M.

2004-05-01

The conjectured transmission price response model presented in the first of this two-paper series considers the expectations of oligopolistic generators regarding how demands for transmission services affect the prices of those services. Here, the model is applied to northwest Europe, simulating a mixed transmission pricing system including export fees, a path-based auction system for between-country interfaces, and implicit congestion-based pricing of internal country constraints. The path-based system does not give credit for counterflows when calculating export capability. The application shows that this no-netting policy can exacerbate the economic inefficiencies caused by oligopolistic pricing by generators. The application also illustrates the effects of different generator conjectures regarding rival supply responses and transmission prices. If generators anticipate that their increased demand for transmission services will increase transmission prices, then competitive intensity diminishes and energy prices rise. In the example here, the effect of this anticipation is to double the price increase that results from oligopolistic (Cournot) competition among generators

Transmission dispatch and congestion management in open market systems

Science.gov (United States)

Fang, Risheng

This thesis is located in the domain of electricity supply industry restructuring. It deals with emerging issues, whose understanding is essential to advancing knowledge of open access transmission theory and proceeds to develop approaches for solving the transmission dispatch and congestion management problem. An overview of current trends and experiences in utility restructuring and the main models for restructuring, as well as the classifications of system operators, is first presented. A fully unbundled competitive electricity market model, called the bilateral/multilateral trades model, is then developed. A survey of current research in transmission dispatch and congestion management is included with discussion of transmission capacity and ancillary services. A methodology for the power dispatch problem in a structure dominated by bilateral and multilateral transmission contracts is presented. Group structures are mathematically formulated and explored and three basic types of curtailment strategies proposed for use by market participants. A more complex model is then developed, which takes into account the co-existence of bilateral and multilateral contracts with pool type dynamic supplies and demands based on bids and market clearing prices. An integrated dispatch strategy to reconcile all three types of transactions (bilateral, multilateral and pool) is then developed. Prioritization of electricity transactions and related curtailment strategies are explored and a mechanism for coordination between market participants to achieve additional economic advantages is described. A theory of security based rescheduling is presented in order to investigate the security-related aspects of operation in an unbundled and deregulated system. The impact of post-contingency corrective capability on optimal rescheduling results has been identified and the advantage of incorporating post-contingency corrective rescheduling into the objective function demonstrated. Finally

FTR-option formulation and pricing

International Nuclear Information System (INIS)

Parmeshwaran, Vijay; Muthuraman, Kumar

2009-01-01

Recent changes in electricity markets have advocated the use of Local Marginal Prices (LMP) for congestion management and pricing. From the perspective of market participants, the LMPs pose a risk since they are not known before a transaction on the grid is made. Financial transmission rights (FTR) are instruments that help market participants hedge this risk and are issuable in two flavors - obligations and options. While pricing obligations are much easier, pricing FTR options pose a significant challenge. In this paper we develop a computational method for pricing FTR options. We also discuss the problem of designing financial instrument sets that assure revenue adequacy for the issuer. We point out the difficulty in assuring revenue adequacy when FTR options are present and propose a scheme for overcoming the difficulty. The proposed pricing method can be used to compute prices of options and obligations in the primary market or as a reliable pricing tool to compute option prices in the secondary market. Finally using a test network we present and discuss numerical results. (author)

The Nordic electric power market. A study of the market characteristics, price factors and the competitive environment of the Nordic power market

International Nuclear Information System (INIS)

Keskikallio, J.; Lindholm, J.

2003-06-01

The market price of power depends on the balance between energy supply and demand. This balance depends on several external factors: the hydrological situation, temperature, time, fuel prices and exchange rates, transmission capacity and congestion, business cycles, other weather-related factors (wind, sun etc.) There are interdependencies between the factors, but the greatest price effects are caused by changes in the hydrological situation (affects energy supply) and temperature (affects mainly demand). Transmission capacity is normally sufficient, especially between Sweden and Finland. When congestion occurs, the price effects may be drastic, due to differences between the countries in the energy production mix. Price areas with several other bordering price areas (Oslo) have the lowest price level. The Helsinki area has the highest price level over time. Congestion is more frequent between southern Sweden and Norway, which accounts for a major part of the difference between the Helsinki area price and the system price. Market concentration is very high in separate price areas, but only moderate for the Nordic market as a whole. Congestion automatically leads to a highly concentrated sub-market. Further market concentration should be avoided, and congestion management should be improved in order to ensure a functioning market. Our findings also included the fact that although power producers have increased their profits since the deregulation of the market, there were no conclusive evidence of market power abuse. A continued trend toward higher profits may change the situation in the future, as the possibility to take advantage of market power already exists. Transmission System Operators (TSO's) have a crucial role for ensuring a functioning power market. As the actions of the TSO may have adverse effects, they should be continuously monitored and subject to much tighter scrutiny than 'ordinary' energy companies. Issues have arisen from the TSO's trading of

Markets in real electric networks require reactive prices

International Nuclear Information System (INIS)

Hogan, W.W.

1996-01-01

Extending earlier seminal work, the author finds that locational spot price differences in an electric network provide the natural measure of the appropriate internodal transport charge. However, the problem of loop flow requires different economic intuition for interpreting the implications of spot pricing. The Direct Current model, which is the usual approximation for estimating spot prices, ignores reactive power effects; this approximation is best when thermal constraints create network congestion. However, when voltage constraints are problematic, the DC Load model is insufficient; a full AC Model is required to determine both real and reactive spot prices. 16 figs., 3 tabs., 22 refs

Socioeconomic differences in public acceptability and car use adaptation towards urban road pricing

DEFF Research Database (Denmark)

Gehlert, Tina; Kramer, Christiane; Nielsen, Otto Anker

2011-01-01

Urban road pricing is regarded as an effective instrument to reduce traffic congestion and environmental-related problems in metropolitan areas. Whereas the overall impact of urban road pricing on car use adaptation and public acceptability is known, there are only inconsistent results concerning...

Framework for Traffic Congestion Management

Directory of Open Access Journals (Sweden)

Mahmud Hassan TALUKDAR

2013-06-01

Full Text Available Traffic Congestion is one of many serious global problems in all great cities resulted from rapid urbanization which always exert negative externalities upon society. The solution of traffic congestion is highly geocentric and due to its heterogeneous nature, curbing congestion is one of the hard tasks for transport planners. It is not possible to suggest unique traffic congestion management framework which could be absolutely applied for every great cities. Conversely, it is quite feasible to develop a framework which could be used with or without minor adjustment to deal with congestion problem. So, the main aim of this paper is to prepare a traffic congestion mitigation framework which will be useful for urban planners, transport planners, civil engineers, transport policy makers, congestion management researchers who are directly or indirectly involved or willing to involve in the task of traffic congestion management. Literature review is the main source of information of this study. In this paper, firstly, traffic congestion is defined on the theoretical point of view and then the causes of traffic congestion are briefly described. After describing the causes, common management measures, using world- wide, are described and framework for supply side and demand side congestion management measures are prepared.

Congestion Tolling for Mixed Urban Freight and Passenger Traffic

Directory of Open Access Journals (Sweden)

Xie Chaoda

2017-01-01

Full Text Available This paper investigates the welfare effects of optimal tolling on urban traffic congestion, in a bottleneck model, with mixed freight and passenger users. The users’ marginal utility of time is considered to be varying with time. Under both no-toll equilibrium and socially optimal tolling, the users are found to sort their arrival time according to the increasing rates of marginal utility at the destination. The optimal toll that maximizes social welfare does not change each user's indirect utilit y relative to the no-toll equilibrium, but completely removes the queue, which also removes the barrier of freight carriers to accept congestion pricing by relating their marginal utilities directly to the toll. When the toll is equally rebated, the proposed social optimal tolling is a Pareto improvement relative to the no-toll equilibrium. Those more productive users also suffer more in both no-toll equilibrium and optimal tolling, which indicates that a differentiated redistribution of toll revenues could be an incentive to improve productivity.

Managing congestion in distribution grids - Market design consideration. How heat pumps can deliver flexibility though well-designed markets and virtual power plant technology

Energy Technology Data Exchange (ETDEWEB)

Holmberg Rasmussen, L. [NEAS Energy, Aalborg (Denmark); Bang, C.; Togeby, M. [Ea Energy Analyses, Copenhagen (Denmark)

2012-10-15

Heat pumps can be used to reduce oil and natural gas consumption and can assist in the integration of increased amounts of wind power in the electricity system. The new electricity demand may increase the value of electricity generated by wind power. This can be the result even without any advanced control of the heat pumps. However, heat pumps can be controlled according to prices, and this can both reduce the energy cost for end-users and be beneficial for the energy system. Variable prices can reflect spot prices, and in the future, operation of heat pumps may also reflect more dynamic prices, for example by delivering regulating power. Regulating power prices can be attractive for the end-user because the variation is considerable and includes many low prices. Heat pumps (and also electric vehicles) may potentially create overloading of electricity lines. Distribution grids in particular may be challenged if a large number of these units draw electricity at the same time. This challenge can be amplified when heat pumps react to price signals. The economic optimisation of the heat pump operation may result in an increased correlation of their electricity demand. The price signal may lead to a loss of diversity in the on/off cycles of the control. In the future it is quite foreseeable that heat pumps could deliver regulating power, thereby assisting in the maintenance of the balance in an overall system with significant wind power. Thus another example of a potential problem would be if all heat pumps react to the same price signal at the same time (i.e. delivering down regulation by switching on), as this could also result in the overloading of local distribution networks. Seen in light of the focus on smart grid solutions, the ideal response to the above congestion examples would be to send a high distribution tariff for the relevant time to the areas where congestion is likely. This would solve the local problem, while at the same time allow the large majority

Road pricing as an impetus for environment-friendly travel behavior : Results from a stated adaptation experiment

NARCIS (Netherlands)

Janssens, D.; Cools, M.; Moons, E.; Wets, G.; Arentze, Theo A.; Timmermans, Harry J P

2009-01-01

An important policy instrument for governments to modify travel behavior and manage the increasing travel demand is the introduction of a congestion pricing system. In this study, the influence of a detailed classification of activities is examined to assess likely traveler response to congestion

Road pricing policy process : The interplay between policy actors, the media and public

NARCIS (Netherlands)

Ardiç, O.

2015-01-01

Although road pricing policies are generally seen as an effective measure to deal with transport related problems (e.g. congestion), the number of implemented road pricing schemes is relatively limited. The thesis aims to gain insights into complex interplay between policy actors, media and public

The sequential price of anarchy for atomic congestion games

NARCIS (Netherlands)

de Jong, Jasper; Uetz, Marc Jochen; Liu, Tie-Yan; Qi, Qi; Ye, Yinyu

2014-01-01

In situations without central coordination, the price of anarchy relates the quality of any Nash equilibrium to the quality of a global optimum. Instead of assuming that all players choose their actions simultaneously, we consider games where players choose their actions sequentially. The sequential

The sequential price of anarchy for atomic congestion games

NARCIS (Netherlands)

de Jong, Jasper; Uetz, Marc Jochen

2014-01-01

In situations without central coordination, the price of anarchy relates the quality of any Nash equilibrium to the quality of a global optimum. Instead of assuming that all players choose their actions simultaneously, here we consider games where players choose their actions sequentially. The

Congestion rents and FTR evaluations in mixed-pool-bilateral systems

International Nuclear Information System (INIS)

Liu, Minghai; Gross, George

2008-01-01

Evaluation of key metrics for congestion management, including the congestion rents and the financial transmission rights (FTR) payoffs, requires the efficient allocation of transmission services and the calculation of appropriate locational marginal prices (LMPs). This requirement is particularly acute when there are bilateral transactions coexisting with the centralized pool markets. We propose a new formulation for this purpose, which captures explicitly the contribution of the bilateral transactions to the social welfare. The proposed formulation effectively integrates the pool market and the bilateral transactions on a consistent basis and results in the more efficient allocation of the transmission resources than the conventional tool. We assess analytically the capabilities of the proposed formulation and solution and quantify the improvements in the evaluations over those done using the conventional approach. Such improvements are also illustrated using simulation results on a wide range of test systems including the IEEE 118-bus network. (author)

Price-based control of electrical power systems

NARCIS (Netherlands)

Jokic, A.; Lazar, M.; Bosch, van den P.P.J.; Negenborn, R.R.; Lukszo, Z.; Hellendorn, H.

2010-01-01

In this chapter we present the price-based control as a suitable approach to solve some of the challenging problems facing future, market-based power sys tems. On the example of economically optimal power balance and transmission network congestion control, we present how global objectives and

Modeling transport pricing with multiple stakeholders. Working paper : Methodology and a case study

NARCIS (Netherlands)

Smits, E.

2012-01-01

Pricing measures (e.g., a kilometre charge or cordon toll) are used to improve the external effects of transportation (e.g., congestion or emissions). This working paper presents a planning model for pricing while taking the preferences and interactions of multiple stakeholders (e.g., governments or

Development of a Model for a Cordon Pricing Scheme Considering Environmental Equity: A Case Study of Tehran

Directory of Open Access Journals (Sweden)

Shahriar Afandizadeh

2016-02-01

Full Text Available Congestion pricing strategy has been recognized as an effective countermeasure in the practical field of urban traffic congestion mitigation. Despite the positive effects of congestion pricing, its implementation has faced problems. This paper investigates the issue of environmental equity in cordon pricing and a park-and-ride scheme. Although pollution decreases inside the cordon by implementation of cordon pricing, air pollutants emission may increase in some links and in the whole network. Therefore, an increase in air emissions in the network means more emission outside the cordon. In fact, due to the implementation of this policy, air pollutants emission may transfer from inside to outside the cordon, creating a type of environmental inequity. To reduce this inequity, a bi-level optimization model with an equity constraint is developed. The proposed solution algorithm based on the second version of the strength Pareto evolutionary algorithm (SPEA2 is applied to the city network in Tehran. The results revealed that it seems reasonable to consider environmental equity as an objective function in cordon pricing. In addition, we can create a sustainable situation for the transportation system by improving environmental inequity with a relatively low reduction in social welfare. Moreover, there are environmental inequity impacts in real networks, which should be considered in the cordon pricing scheme.

Electricity transmission pricing: Tracing based point-of-connection tariff

International Nuclear Information System (INIS)

Abhyankar, A.R.; Khaparde, S.A.

2009-01-01

Point-of-connection (POC) scheme of transmission pricing in decentralized markets charges the participants a single rate per MW depending on their point-of-connection. Use of grossly aggregated postage stamp rates as POC charges fails to provide appropriate price signals. The POC tariff based on distribution of network sunk costs by employing conventional tracing assures recovery of sunk costs based on extent of use of network by participants. However, the POC tariff by this method does not accommodate economically efficient price signals which correspond to marginal costs. On the other hand, the POC tariff, if made proportional to marginal costs alone, fails to account for sunk costs and extent of use of network. This paper overcomes these lacunae by combining the above stated desired objectives under the recently proposed optimal tracing framework. Since real power tracing problem is amenable to multiple solutions, it is formulated as linearly constrained optimization problem. By employing this methodology, consideration of extent of network use and sunk cost recovery are guaranteed, while objective function is designed such that the spatial pattern of price signals closely follows the pattern of scaled locational marginal prices. The methodology is tested on IEEE 30 bus system, wherein average power flow pattern is established by running various simulation states on congested and un-congested network conditions. (author)

Coordination of Nordic system operators in the electric power market - profit from improved capacity utilization and a more flexible division into price zones

International Nuclear Information System (INIS)

Bjoerndal, Mette; Joernsten, Kurt

2001-08-01

This report evaluates the possible profits of establishing a common system operator function in the Nordic electric power market. The main focus is placed on how to deal with congestion in the transmission grid. To estimate possible profits from a better utilization of the resources in the Nordic grid, the authors have analyzed socio-economic profits for several load scenarios. A simplified model of the Nordic stock area was used in the calculations. The existence of two methods of dealing with congestion in the grid may lead to reduced capacity utilization and to greater price differences than necessary. The examples show that ''indirect'' congestion control may be very expensive and that considerable cost reduction can be achieved by improved exploitation of congestion. This implies that if the Nordic area is divided into price zones, it is advantageous to regard the grid as an entity independent of national borders and system operators and to let the real transmission limitations determine the price zoning

Containing air pollution and traffic congestion: Transport policy and the environment in Singapore

Science.gov (United States)

Chin, Anthony T. H.

Land transportation remains one of the main contributors of noise and air pollution in urban areas. This is in addition to traffic congestion and accidents which result in the loss of productive activity. While there is a close relationship between traffic volumes and levels of noise and air pollution, transport authorities often assume that solving traffic congestion would reduce noise and air pollutant levels. Tight control over automobile ownership and use in Singapore has contributed in improving traffic flows, travel speeds and air quality. The adoption of internationally accepted standards on automobile emissions and gasoline have been effective in reducing air pollution from motor vehicles. Demand management measures have largely focused on controlling the source of traffic congestion, i.e. private automobile ownership and its use especially within the Central Business District during the day. This paper reviews and analyzes the effectiveness of two measures which are instrumental in controlling congestion and automobile ownership, i.e. road pricing and the vehicle quota scheme (VQS). While these measures have been successful in achieving desired objectives, it has also led to the spreading of traffic externalities to other roads in the network, loss in consumer welfare and rent seeking by automobile traders.

Evaluating the effects of urban congestion pricing: Geographical accessibility versus social surplus

NARCIS (Netherlands)

Tillema, T.; Verhoef, E.T.; van Wee, G.P.; van Amelsfort, D.

2011-01-01

In urbanised areas around the world, road pricing policies are considered more and more frequently, the aim often being to alleviate (some of the) external traffic-related costs. To assess the effects of a proposed road pricing measure, several evaluation measures can be used, coming from different

Evaluating the effects of urban congestion pricing : geographical accessibility versus social surplus

NARCIS (Netherlands)

Tillema, Taede; Verhoef, Erik; van Wee, Bert; van Amelsfort, Dirk; van Wee, G.P

2011-01-01

In urbanised areas around the world, road pricing policies are considered more and more frequently, the aim often being to alleviate (some of the) external traffic-related costs. To assess the effects of a proposed road pricing measure, several evaluation measures can be used, coming from different

How Congested Jakarta is? Perception of Jakarta’s Citizen on Traffic Congestion

Directory of Open Access Journals (Sweden)

Muhammad Halley Yudhistira

2017-11-01

Full Text Available This paper aims to reveal the behavior and perception of Jakarta’s citizens on traffic congestion in Jakarta. Although this approach is somewhat well-developed in behavioral science, its utilization in urban economics study, is still limited. Detecting the traffic congestion and its cause mainly relies on physical (engineering methods, i.e V/C ratio. Here, we define the traffic congestion through two variables; ordinal traffic congestion perception and proportion of expected travel time to perceived travel time. Using a non-probabilistic sampling survey held in one of densest business district in Jakarta called Sudirman-Thamrin Golden Triangle Area; the estimation results show that travel behavior plays a major role in affecting travel time perceptions.

Real-time control of power systems using nodal prices

NARCIS (Netherlands)

Jokic, A.; Lazar, M.; Bosch, van den P.P.J.

2009-01-01

This article presents a novel control scheme for achieving optimal power balancing and congestion management in electrical power systems via nodal prices. We develop a dynamic controller that guarantees economically optimal steady-state operation while respecting all line flow constraints in

Multiple stakeholders in road pricing: A game theoretic approach

NARCIS (Netherlands)

Ohazulike, Anthony; Still, Georg J.; Kern, Walter; van Berkum, Eric C.; Hausken, Kjell; Zhuang, Jun

2015-01-01

We investigate a game theoretic approach as an alternative to the standard multi-objective optimization models for road pricing. Assuming that various, partly conflicting traffic externalities (congestion, air pollution, noise, safety, etcetera) are represented by corresponding players acting on a

The price of anarchy in series-parallel graphs

NARCIS (Netherlands)

Senster, P.; Van Heugten, T.; Ten Thije, O.

2010-01-01

Congestion games model self-interested agents competing for resources in communication networks. The price of anarchy quantifies the deterioration in performance in such games compared to the optimal solution. Recent research has shown that, when the social cost is defined as the maximum cost of all

Long-term congestion management by investment in gas-turbine generators : a cost-benefit analysis

International Nuclear Information System (INIS)

Tuan, L.A.; Bhattacharya, K.

2007-01-01

Load management is one of the most important tasks in the operation of an electric power system. Transmission congestion occurs whenever the grid has one or more violations of the physical, operation, or policy constraints under which it normally operates. In a deregulated electricity market, the independent system operator (ISO) must ensure that contracted power transactions are carried out reliably. Several schemes of congestion management run the risk of increasing electricity prices due to the market power of local generators in congested areas. An alternative is to manage congestion through the installation of reserve gas turbine generators which can be brought online to the system within a short time. The use of gas turbines at different buses in the system can enhance the system in ways of transmission relief during emergency events. This paper proposed a framework for the evaluation of long-term investment by the ISO on gas-turbine generators as a tool for providing transmission congestion relief in the dispatch stage based on cost-benefit analysis. The objective of the framework is to optimally decide the locations and sizes of the generators at different buses in the network in order to minimize the total cost of investment of gas turbines and to minimize total system congestion. A bus-wise cost-benefit analysis was carried out by solving the DC optimal power flow (dc-OPF) model. The CIGRE 32-Bus system was used for the case study. It was shown that network overloading can be significantly reduced with the support of gas turbines at selected buses. The long-term decision of the investment on gas-turbine would depend on the opportunity cost of the gas-turbine with respect to the congestion problem. The gas turbines could also reduce the amount of unserved energy during peak load conditions. 11 refs., 4 tabs., 3 figs

The Effects of Average Revenue Regulation on Electricity Transmission Investment and Pricing

OpenAIRE

Isamu Matsukawa

2005-01-01

This paper investigates the long-run effects of average revenue regulation on an electricity transmission monopolist who applies a two- part tariff comprising a variable congestion price and a non-negative fixed access fee. A binding constraint on the monopolist fs expected average revenue lowers the access fee, promotes transmission investment, and improves consumer surplus. In a case of any linear or log-linear electricity demand function with a positive probability that no congestion occur...

Tradable Driving Credits : car users' responses towards an innovative pricing measure in the Netherlands and China

NARCIS (Netherlands)

Dogterom, N.J.

2017-01-01

Car traffic volumes continue to increase rapidly worldwide, leading to steadily rising levels of congestion and harmful emissions in many urbanised areas. Transport researchers have long been convinced of the power of pricing solutions to mitigate these problems. However, pricing initiatives have

Congestion with incidents

DEFF Research Database (Denmark)

Fosgerau, Mogens

2010-01-01

This paper considers the impact of random delays during a repeatedly occurring demand peak in a congested facility, such as an airport or an urban road. Congestion is described in the form of a dynamic queue using the Vickrey bottleneck model and assuming Nash equilibrium in departure times. Ever...

Market performance and bidders' bidding behavior in the New York Transmission Congestion Contract market

International Nuclear Information System (INIS)

Zhang, Ning

2009-01-01

Using publicly available bidder level bids data for Transmission Congestion Contracts (TCCs) and the realized awards of TCCs in the NYISO monthly reconfiguration auctions from June 2000 to December 2004, we examine both market performance and bidders' bidding behavior in the auctions. The data show significant under-pricing in the realized awards of TCCs. Theories suggest that under-pricing may arise from risk-aversion, monopsonistic market power or winner's curse. Our empirical analysis illustrates that all of the three effects play a role in the NYISO TCCs market. Both market performance and bidders' bidding strategies can be best explained by the theoretical model with asymmetric information and risk-averse bidders. (author)

Bridging the gap between theory and practice of transmission pricing

International Nuclear Information System (INIS)

Hughes, W.R.; Felak, R.

1996-01-01

The authors describe some strategies for pricing transmission service. Traditionally, wheeling prices have been postage stamp rates based on the level of megawatt demand; a related approach would assign grid costs to customers based on their respective shares of overall megawatt-miles. Innovative regulators have recently approved transmission rates based on opportunity cost of foregone capacity and the incremental costs of additional capacity needed to enable delivery. Others determined prices designed to reflect short-run congestion costs on the grid. The authors assess these pricing approaches and their effects on the distribution of wealth and economic efficiency for both firm and interruptible services. 3 refs

Charging versus rewarding : A comparison of road-pricing and rewarding peak avoidance in the Netherlands

NARCIS (Netherlands)

Tillema, Taede; Ben-Elia, Eran; Ettema, Dick; van Delden, Janet

The aim of this paper is to compare two congestion management schemes road-pricing and peak avoidance rewarding and their impact on commuter behaviour, based on two studies that were conducted in the Netherlands. The road-pricing study is based on stated preference data, whereas the study involving

Strategic Generation with Conjectured Transmission Price Responses in a Mixed Transmission Pricing System. Part 1. Formulation

International Nuclear Information System (INIS)

Hobbs, B.F.; Rijkers, F.A.M.

2004-05-01

The conjectured supply function (CSF) model calculates an oligopolistic equilibrium among competing generating companies (GenCos), presuming that GenCos anticipate that rival firms will react to price increases by expanding their sales at an assumed rate. The CSF model is generalized here to include each generator's conjectures concerning how the price of transmission services (point-to-point service and constrained interfaces) will be affected by the amount of those services that the generator demands. This generalization reflects the market reality that large producers will anticipate that they can favorably affect transmission prices by their actions. The model simulates oligopolistic competition among generators while simultaneously representing a mixed transmission pricing system. This mixed system includes fixed transmission tariffs, congestion-based pricing of physical transmission constraints (represented as a linearized dc load flow), and auctions of interface capacity in a path-based pricing system. Pricing inefficiencies, such as export fees and no credit for counterflows, can be simulated. The model is formulated as a linear mixed complementarity problem, which enables very large market models to be solved. In the second paper of this two-paper series, the capabilities of the model are illustrated with an application to northwest Europe, where transmission pricing is based on such a mixture of approaches

OPTIMAL CONGESTION CHARGES IN GENERAL EQUILIBRIUM

Directory of Open Access Journals (Sweden)

Dong-Joo MOON, Ph.D.

2002-01-01

Another maximization problem involves characterizing the second-best optimal solution. In this problem, it is assumed to impose the congestion toll only on a single highway link. This problem yields the second-best congestion toll different from the first-best one. This second-best optimal congestion toll has the structure to reflect its impact on other highway links exempt from the congestion charge program.

FPGA Congestion-Driven Placement Refinement

Energy Technology Data Exchange (ETDEWEB)

Vicente de, J.

2005-07-01

The routing congestion usually limits the complete proficiency of the FPGA logic resources. A key question can be formulated regarding the benefits of estimating the congestion at placement stage. In the last years, it is gaining acceptance the idea of a detailed placement taking into account congestion. In this paper, we resort to the Thermodynamic Simulated Annealing (TSA) algorithm to perform a congestion-driven placement refinement on the top of the common Bounding-Box pre optimized solution. The adaptive properties of TSA allow the search to preserve the solution quality of the pre optimized solution while improving other fine-grain objectives. Regarding the cost function two approaches have been considered. In the first one Expected Occupation (EO), a detailed probabilistic model to account for channel congestion is evaluated. We show that in spite of the minute detail of EO, the inherent uncertainty of this probabilistic model impedes to relieve congestion beyond the sole application of the Bounding-Box cost function. In the second approach we resort to the fast Rectilinear Steiner Regions algorithm to perform not an estimation but a measurement of the global routing congestion. This second strategy allows us to successfully reduce the requested channel width for a set of benchmark circuits with respect to the widespread Versatile Place and Route (VPR) tool. (Author) 31 refs.

Road traffic congestion a concise guide

CERN Document Server

Falcocchio, John C

2015-01-01

This book on road traffic congestion in cities and suburbs describes congestion problems and shows how they can be relieved. The first part (Chapters 1 - 3) shows how congestion reflects transportation technologies and settlement patterns. The second part (Chapters 4 - 13) describes the causes, characteristics, and consequences of congestion. The third part (Chapters 14 - 23) presents various relief strategies - including supply adaptation and demand mitigation - for nonrecurring and recurring congestion. The last part (Chapter 24) gives general guidelines for congestion relief and provides a general outlook for the future. The book will be useful for a wide audience - including students, practitioners and researchers in a variety of professional endeavors: traffic engineers, transportation planners, public transport specialists, city planners, public administrators, and private enterprises that depend on transportation for their activities.  

Signalling and obfuscation for congestion control

Science.gov (United States)

Mareček, Jakub; Shorten, Robert; Yu, Jia Yuan

2015-10-01

We aim to reduce the social cost of congestion in many smart city applications. In our model of congestion, agents interact over limited resources after receiving signals from a central agent that observes the state of congestion in real time. Under natural models of agent populations, we develop new signalling schemes and show that by introducing a non-trivial amount of uncertainty in the signals, we reduce the social cost of congestion, i.e., improve social welfare. The signalling schemes are efficient in terms of both communication and computation, and are consistent with past observations of the congestion. Moreover, the resulting population dynamics converge under reasonable assumptions.

Carpooling and Driver Responses to Fuel Price Changes: Evidence from Traffic Flows in Los Angeles

OpenAIRE

Antonio M. Bento; Jonathan E. Hughes; Daniel T. Kaffine

2012-01-01

Understanding how drivers respond to fuel price changes has important implications for highway congestion, accidents, carbon policy, local air pollution and taxation. We examine the underexplored relationship between fuel prices and carpooling. Using a simple theoretical model we show that traffic flows in mainline lanes decrease when fuel prices increase. However in carpool (HOV) lanes, flow can either increase or decrease. Traffic flows in mainline lanes are shown to be more responsive to p...

On the long run effects of market splitting: Why more price zones might decrease welfare

International Nuclear Information System (INIS)

Grimm, Veronika; Martin, Alexander; Weibelzahl, Martin; Zöttl, Gregor

2016-01-01

In liberalized electricity markets we observe different approaches to congestion management. While nodal pricing is implemented in Canada and some markets in the United States, European markets are split up into a limited number of price zones with uniform prices, in order to at least partially realize the benefits of regional price differentiation. Zonal boundaries often coincide with national borders, but some countries are also split into multiple zones. In this paper we shed light on possible negative welfare effects of market splitting that arise in a model where investment incentives in new generation capacity are taken into account if zones are misspecified. We show that standard approaches to configure price zones – on the basis of projected nodal price differences or congested transmission capacity – may fail to suggest reasonable zone specifications. Also an adjustment of Available Transfer Capacities (ATCs) between zones or a switch to flow-based market splitting does not ensure positive welfare effects. Our analysis suggests that a careful and detailed evaluation of the system is needed to ensure a reasonable zone configuration. - Highlights: •We analyze investment and production in energy only markets with market splitting. •Market splitting can lead to decreased welfare even for reasonably chosen zones. •We identify the reasons for the negative impact of introducing prices zones.

Price-based optimal control of power flow in electrical energy transmission networks

NARCIS (Netherlands)

Jokic, A.; Lazar, M.; Bosch, van den P.P.J.; Bemporad, A.; Bicchi, A.; Buttazzo, G.

2007-01-01

This article presents a novel control scheme for achieving optimal power balancing and congestion control in electrical energy transmission networks via nodal prices. We develop an explicit controller that guarantees economically optimal steady-state operation while respecting all line flow

A Multilevel Congestion-Based Global Router

Directory of Open Access Journals (Sweden)

Logan Rakai

2009-01-01

Full Text Available Routing in nanometer nodes creates an elevated level of importance for low-congestion routing. At the same time, advances in mathematical programming have increased the power to solve complex problems, such as the routing problem. Hence, new routing methods need to be developed that can combine advanced mathematical programming and modeling techniques to provide low-congestion solutions. In this paper, a hierarchical mathematical programming-based global routing technique that considers congestion is proposed. The main contributions presented in this paper include (i implementation of congestion estimation based on actual routing solutions versus purely probabilistic techniques, (ii development of a congestion-based hierarchy for solving the global routing problem, and (iii generation of a robust framework for solving the routing problem using mathematical programming techniques. Experimental results illustrate that the proposed global router is capable of reducing congestion and overflow by as much as 36% compared to the state-of-the-art mathematical programming models.

Transmission congestion and voltage profile management coordination in competitive electricity markets

International Nuclear Information System (INIS)

Yamin, H.Y.; Shahidehpour, S.M.

2003-01-01

This paper describes a generalized active/reactive iterative coordination process between GENCOs and the Independent System Operator (ISO) for active (transmission congestion) and reactive (voltage profile) management in the day-ahead market. GENCOs apply priced-based unit commitment without transmission and voltage security constraints, schedule their units and submit their initial bids to the ISO. The ISO executes congestion and voltage profile management for eliminating transmission and voltage profile violations. If violations are not eliminated, the ISO minimizes the transmission and voltage profile violations and sends a signal via the Internet to GENCOs. GENCOs reschedule their units taking into account the ISO signals and submit modified bids to the ISO. The voltage problem is addressed and a linear model is formulated and used in the proposed method. The voltage problem is formulated as a linear programming with a block-angular structure and Dantzig-Wolfe decomposition is applied to generate several smaller problems for a faster and easier solution of large-scale power systems. Two 36 unit GENCOs are used to demonstrate the performance of the proposed generalized active/reactive coordination algorithm. (author)

Price Elasticity of Demand and Capacity-Restraint Transit Fare Strategy: A Case Study of Bangkok Mass Transit System

Directory of Open Access Journals (Sweden)

Ackchai Sirikijpanichkul

2015-01-01

Full Text Available Traffic congestion is a chronic problem of Bangkok. Similar to other metropolises, the city perpetually seeks for alternatives to road travel. Mass rapid transit seems to be the only way out that is expected to mitigate traffic congestion in the city. However, without common fare system, travelers need to pay an initial entrance fee every time they enter each transit system. This excess cost tapers the demand and affects the efficient use of the system. This research investigates the influence of fare price on transit use which is measured by price elasticity of demand and proposes the optimum fare price if the common fare is used. The analysis is based on the findings from the stated preference survey techniques. Finally, the conclusion on fare level that encourage more patronage, maintain service quality and operator revenue is addressed.

Optimal model of congestion management in deregulated environment of power sector with promotion of renewable energy sources

International Nuclear Information System (INIS)

Sood, Yog Raj; Singh, Randhir

2010-01-01

In the competitive electricity market it becomes very much important to give special consideration for development of renewable energy sources (RESs) due to environmental and other social problems related with conventional generations. So this paper presents an optimal model of congestion management with special emphasis for promotion of RES in competitive electricity market. This paper presents a generalized optimal model of congestion management for deregulated power sector that dispatches the pool in combination with privately negotiated bilateral and multilateral contracts while maximizing social benefit. This model determines the locational marginal pricing (LMP) based on marginal cost theory. It also determines the size of non-firm transactions as well as pool demand and generations. Both firms as well as non-firm transactions are considered in this model. The proposed model has been applied to IEEE-30 bus test system with addition of some RES for analysis of the proposed model. The RES supplies its power to load either through the firm transaction or through power pool. The power from RES is not subjected to any curtailment in proposed model of congestion management. (author)

Effects of series compensation on spot price power markets

International Nuclear Information System (INIS)

Shrestha, G.B.; Wang Feng

2005-01-01

The operation of a deregulated power market becomes more complex as the generation scheduling is dependent on suppliers' and consumers' bids. With large number of transactions in the power market changing in time, it is more likely for some transmission lines to face congestion. Series compensation, such as TCSC, with its ability to directly control the power flow can be very helpful to improve the operation of transmission networks. The effects of TCSC on the operation of a spot price power market are studied in this paper using the modified IEEE 14-bus system. Optimal Power Flow incorporating TCSC is used to implement the spot price market. Linear bids are used to model suppliers' and consumers' bids. Issues of location and cost of TCSC are discussed. The effects of levels of TCSC compensation on wide range of system quantities are studied. The effects on the total social benefit, the spot prices, transmission congestion, total generation and consumption, benefit to individual supplier and consumer etc. are discussed. It is demonstrated that though use of TCSC makes the system more efficient and augments competition in the market, it is not easy to establish general relationships between the levels of compensation and various market quantities. Simulation studies like these can be used to assess the effects of TCSC in specific systems. (Author)

Software-Defined Congestion Control Algorithm for IP Networks

Directory of Open Access Journals (Sweden)

Yao Hu

2017-01-01

Full Text Available The rapid evolution of computer networks, increase in the number of Internet users, and popularity of multimedia applications have exacerbated the congestion control problem. Congestion control is a key factor in ensuring network stability and robustness. When the underlying network and flow information are unknown, the transmission control protocol (TCP must increase or reduce the size of the congestion window to adjust to the changes of traffic in the Internet Protocol (IP network. However, it is possible that a software-defined approach can relieve the network congestion problem more efficiently. This approach has the characteristic of centralized control and can obtain a global topology for unified network management. In this paper, we propose a software-defined congestion control (SDCC algorithm for an IP network. We consider the difference between TCP and the user datagram protocol (UDP and propose a new method to judge node congestion. We initially apply the congestion control mechanism in the congested nodes and then optimize the link utilization to control network congestion.

Optimal Energy Management for the Integrated Power and Gas Systems via Real-time Pricing

DEFF Research Database (Denmark)

Shu, KangAn; Ai, Xiaomeng; Wen, Jinyu

2018-01-01

This work proposed a bi-level formulation for energy management in the integrated power and natural gas system via real-time price signals. The upper-level problem minimizes the operational cost, in which dynamic electricity price and dynamic gas tariff are proposed. The lower level problem...... and P2Gs plants follow the system operator’s preferences such as wind power accommodation, mitigation of unsupplied load and relieving the network congestion....

Traveler response to coexisting multiple pricing schemes results of elaborated mixture-amount experiment

NARCIS (Netherlands)

Khademi, E.; Timmermans, H.J.P.; Borgers, A.W.J.

2013-01-01

Many academics and transportation planners seem convinced that pricing schemes may be one of the most effective policy instruments to change travelers' behavior, to minimize congestion and emissions, or to optimize system use otherwise. Consequently, much empirical work has been conducted, although

Higher fuel prices are associated with lower air pollution levels.

Science.gov (United States)

Barnett, Adrian G; Knibbs, Luke D

2014-05-01

Air pollution is a persistent problem in urban areas, and traffic emissions are a major cause of poor air quality. Policies to curb pollution levels often involve raising the price of using private vehicles, for example, congestion charges. We were interested in whether higher fuel prices were associated with decreased air pollution levels. We examined an association between diesel and petrol prices and four traffic-related pollutants in Brisbane from 2010 to 2013. We used a regression model and examined pollution levels up to 16 days after the price change. Higher diesel prices were associated with statistically significant short-term reductions in carbon monoxide and nitrogen oxides. Changes in petrol prices had no impact on air pollution. Raising diesel taxes in Australia could be justified as a public health measure. As raising taxes is politically unpopular, an alternative political approach would be to remove schemes that put a downward pressure on fuel prices, such as industry subsidies and shopping vouchers that give fuel discounts. Copyright © 2014 Elsevier Ltd. All rights reserved.

Coordination of Nordic system operators in the electric power market - profit from improved capacity utilization and a more flexible division into price zones; Koordinering av nordiske systemoperatoerer i kraftmarkedet - gevinster ved bedret kapasitetsutnyttelse og mer fleksibel prisomraadeinndeling

Energy Technology Data Exchange (ETDEWEB)

Bjoerndal, Mette; Joernsten, Kurt

2001-08-01

This report evaluates the possible profits of establishing a common system operator function in the Nordic electric power market. The main focus is placed on how to deal with congestion in the transmission grid. To estimate possible profits from a better utilization of the resources in the Nordic grid, the authors have analyzed socio-economic profits for several load scenarios. A simplified model of the Nordic stock area was used in the calculations. The existence of two methods of dealing with congestion in the grid may lead to reduced capacity utilization and to greater price differences than necessary. The examples show that ''indirect'' congestion control may be very expensive and that considerable cost reduction can be achieved by improved exploitation of congestion. This implies that if the Nordic area is divided into price zones, it is advantageous to regard the grid as an entity independent of national borders and system operators and to let the real transmission limitations determine the price zoning.

Effective Road Model for Congestion Control in VANETs

OpenAIRE

Dongre, Manoj M.; Bawane, Narendra G.

2016-01-01

Congestion on the roads is a key problem to deal with, which wastes valuable time.. Due to high mobility rate and relative speed link failure occur very often. VANET is used to tackle the problem of congestion, and make decisions well in advance to avoid traffic congestion. In this paper we proposed a solution to detect and control the traffic congestion by using of both (V2V) and (V2I), as a result the drivers become aware of the location of congestion as well as way to avoid getting stuck i...

Congestion management in liberalized market environment

International Nuclear Information System (INIS)

2006-01-01

This paper is based on the survey conducted by WG C5.4 on congestion management. It describes market conditions and institutional arrangements in the 18 countries participating in the survey, and internal and cross-border congestion management. The interaction with the electricity market is discussed, considering allocation of transmission capacity, market schedule, congestion management tools and payment for the costs incurred. The survey shows that there is a tendency towards the use of market-based methods. (author)

Application for Single Price Auction Model (SPA) in AC Network

Science.gov (United States)

Wachi, Tsunehisa; Fukutome, Suguru; Chen, Luonan; Makino, Yoshinori; Koshimizu, Gentarou

This paper aims to develop a single price auction model with AC transmission network, based on the principle of maximizing social surplus of electricity market. Specifically, we first formulate the auction market as a nonlinear optimization problem, which has almost the same form as the conventional optimal power flow problem, and then propose an algorithm to derive both market clearing price and trade volume of each player even for the case of market-splitting. As indicated in the paper, the proposed approach can be used not only for the price evaluation of auction or bidding market but also for analysis of bidding strategy, congestion effect and other constraints or factors. Several numerical examples are used to demonstrate effectiveness of our method.

Rerouting algorithms solving the air traffic congestion

Science.gov (United States)

Adacher, Ludovica; Flamini, Marta; Romano, Elpidio

2017-06-01

Congestion in the air traffic network is a problem with an increasing relevance for airlines costs as well as airspace safety. One of the major issue is the limited operative capacity of the air network. In this work an Autonomous Agent approach is proposed to solve in real time the problem of air traffic congestion. The air traffic infrastructures are modeled with a graph and are considered partitioned in different sectors. Each sector has its own decision agent dealing with the air traffic control involved in it. Each agent sector imposes a real time aircraft scheduling to respect both delay and capacity constrains. When a congestion is predicted, a new aircraft scheduling is computed. Congestion is solved when the capacity constrains are satisfied once again. This can be done by delaying on ground aircraft or/and rerouting aircraft and/or postponing the congestion. We have tested two different algorithms that calculate K feasible paths for each aircraft involved in the congestion. Some results are reported on North Italian air space.

Evaluation of pulmonary congestion by computed tomography

International Nuclear Information System (INIS)

Morooka, Nobuhiro; Yamamoto, Hironori; Yoshida, Hideo; Watanabe, Shigeru; Nakamura, Mamoru

1980-01-01

Pulmonary congestion and pulmonary water distribution of lung fields were evaluated by computed tomography (CT) in 31 patients with congestive heart failure and 19 normal subjects in the supine position. In normal subjects, no difference was noted in the CT value between levels of intercostal spaces as well as between right and left lung fields. CT values were greater in posterior lung fields than in anterior lung fields. A significant increase of CT values at both anterior and posterior lung fields was shown in patients with congestive heart failure compared to normal subjects. In congestive heart failure, pulmonary CT values were correlated with various clinical parameters in the order of chest X-ray findings, NYHA functional classification, venous pressure, right heart catheter findings and circulation time. CT values were decreased with the improvement of parameters by medical treatment. Thus, the increase of pulmonary CT values in patients with congestive heart failure indicated the increase of pulmonary blood content and pulmonary tissue edema in a unit volume. This method was particularly useful for the evaluation of pulmonary congestion and pulmonary water distribution. (author)

Power systems locational marginal pricing in deregulated markets

Science.gov (United States)

Wang, Hui-Fung Francis

Since the beginning of the 1990s, the electricity business is transforming from a vertical integrating business to a competitive market operations. The generation, transmission, distribution subsystem of an electricity utility are operated independently as Genco (generation subsystem), Transco (transmission subsystem), and Distco (distribution subsystem). This trend promotes more economical inter- and intra regional transactions to be made by the participating companies and the users of electricity to achieve the intended objectives of deregulation. There are various types of electricity markets that are implemented in the North America in the past few years. However, transmission congestion management becomes a key issue in the electricity market design as more bilateral transactions are traded across long distances competing for scarce transmission resources. It directly alters the traditional concept of energy pricing and impacts the bottom line, revenue and cost of electricity, of both suppliers and buyers. In this research, transmission congestion problem in a deregulated market environment is elucidated by implementing by the Locational Marginal Pricing (LMP) method. With a comprehensive understanding of the LMP method, new mathematical tools will aid electric utilities in exploring new business opportunities are developed and presented in this dissertation. The dissertation focuses on the development of concept of (LMP) forecasting and its implication to the market participants in deregulated market. Specifically, we explore methods of developing fast LMP calculation techniques that are differ from existing LMPs. We also explore and document the usefulness of the proposed LMP in determining electricity pricing of a large scale power system. The developed mathematical tools use of well-known optimization techniques such as linear programming that are support by several flow charts. The fast and practical security constrained unit commitment methods are the

Distribution Locational Marginal Pricing for Optimal Electric Vehicle Charging through Chance Constrained Mixed-Integer Programming

DEFF Research Database (Denmark)

Liu, Zhaoxi; Wu, Qiuwei; Oren, Shmuel S.

2017-01-01

This paper presents a distribution locational marginal pricing (DLMP) method through chance constrained mixed-integer programming designed to alleviate the possible congestion in the future distribution network with high penetration of electric vehicles (EVs). In order to represent the stochastic...

Delay-based virtual congestion control in multi-tenant datacenters

Science.gov (United States)

Liu, Yuxin; Zhu, Danhong; Zhang, Dong

2018-03-01

With the evolution of cloud computing and virtualization, the congestion control of virtual datacenters has become the basic issue for multi-tenant datacenters transmission. Regarding to the friendly conflict of heterogeneous congestion control among multi-tenant, this paper proposes a delay-based virtual congestion control, which translates the multi-tenant heterogeneous congestion control into delay-based feedback uniformly by setting the hypervisor translation layer, modifying three-way handshake of explicit feedback and packet loss feedback and throttling receive window. The simulation results show that the delay-based virtual congestion control can effectively solve the unfairness of heterogeneous feedback congestion control algorithms.

Air congestion delay: a review

Directory of Open Access Journals (Sweden)

Daniel Alberto Pamplona

2016-04-01

Full Text Available This article is a literature review of the air congestion delay and its costs. Air congestion is a worldwide problem. Its existence brings costs for airlines and discomfort for passengers. With the increasing demand for air transport, the study of air congestion has attracted the attention of many researchers around the world. The cause for the delays is erroneously attributed only to the lack of infrastructure investments. The literature review shows that other factors such as population growth, increasing standards of living, lack of operational planning and environmental issues exercise decisive influence. Several studies have been conducted in order to analyze and propose solutions to this problem that affects society as a whole.

The effects of average revenue regulation on electricity transmission investment and pricing

International Nuclear Information System (INIS)

Matsukawa, Isamu

2008-01-01

This paper investigates the long-run effects of average revenue regulation on an electricity transmission monopolist who applies a two-part tariff comprising a variable congestion price and a non-negative fixed access fee. A binding constraint on the monopolist's expected average revenue lowers the access fee, promotes transmission investment, and improves consumer surplus. In a case of any linear or log-linear electricity demand function with a positive probability that no congestion occurs, average revenue regulation is allocatively more efficient than a Coasian two-part tariff if the level of capacity under average revenue regulation is higher than that under a Coasian two-part tariff. (author)

Congestive index of portal vein

International Nuclear Information System (INIS)

Kim, Won Ho; Kim, H. K.; Lee, S. C.; Han, S. H.; Han, K. H.; Chung, J. B.; Choi, H. J.

1989-01-01

In patients with portal hypertension, the blood flow volume is maintained despite decreased blood flow velocity due to enlargement of the vascular cross sectional area. Thus, the 'congestion index' of the portal vein, which is the ratio between the cross sectional area (cm2) and the blood flow velocity (cm/sec) determined by a Doppler ultrasonography, may be a sensitive index by which to assess portal hypertension. We performed Doppler ultrasonography on 24 normal subjects, 14 patients with biopsy proved chronic active hepatitis and 55 patients with liver cirrhosis in order to assess the diagnostic value of the congestion index. The cross sectional area of the portal vein was significantly enlarged and the mean blood flow velocity was significantly reduced in patients with liver cirrhosis compared with controls. However, the blood flow volume was no difference. The congestion index of the portal vein was significantly increased in patients with liver cirrhosis (0.113+0.035) compared with patients with chronic active hepatitis(0.078+0.029) (p<0.001) and controls (0.053+0.016) (p<0.001). The sensitivity, specificity and predictability of the congestion index for detection of patients with the cirrhosis of the liver were 76.4%, 100% and 100% respectively, when the normal range was set at mean+2SD. The results suggest that the congestion index of the portal vein may pla a significant role in diagnosis of portal hypertensive patients

Understanding congested travel in urban areas

Science.gov (United States)

Çolak, Serdar; Lima, Antonio; González, Marta C.

2016-03-01

Rapid urbanization and increasing demand for transportation burdens urban road infrastructures. The interplay of number of vehicles and available road capacity on their routes determines the level of congestion. Although approaches to modify demand and capacity exist, the possible limits of congestion alleviation by only modifying route choices have not been systematically studied. Here we couple the road networks of five diverse cities with the travel demand profiles in the morning peak hour obtained from billions of mobile phone traces to comprehensively analyse urban traffic. We present that a dimensionless ratio of the road supply to the travel demand explains the percentage of time lost in congestion. Finally, we examine congestion relief under a centralized routing scheme with varying levels of awareness of social good and quantify the benefits to show that moderate levels are enough to achieve significant collective travel time savings.

Focus on renal congestion in heart failure.

Science.gov (United States)

Afsar, Baris; Ortiz, Alberto; Covic, Adrian; Solak, Yalcin; Goldsmith, David; Kanbay, Mehmet

2016-02-01

Hospitalizations due to heart failure are increasing steadily despite advances in medicine. Patients hospitalized for worsening heart failure have high mortality in hospital and within the months following discharge. Kidney dysfunction is associated with adverse outcomes in heart failure patients. Recent evidence suggests that both deterioration in kidney function and renal congestion are important prognostic factors in heart failure. Kidney congestion in heart failure results from low cardiac output (forward failure), tubuloglomerular feedback, increased intra-abdominal pressure or increased venous pressure. Regardless of the cause, renal congestion is associated with increased morbidity and mortality in heart failure. The impact on outcomes of renal decongestion strategies that do not compromise renal function should be explored in heart failure. These studies require novel diagnostic markers that identify early renal damage and renal congestion and allow monitoring of treatment responses in order to avoid severe worsening of renal function. In addition, there is an unmet need regarding evidence-based therapeutic management of renal congestion and worsening renal function. In the present review, we summarize the mechanisms, diagnosis, outcomes, prognostic markers and treatment options of renal congestion in heart failure.

Congestion and cascades in payment systems

Science.gov (United States)

Beyeler, Walter E.; Glass, Robert J.; Bech, Morten L.; Soramäki, Kimmo

2007-10-01

We develop a parsimonious model of the interbank payment system. The model incorporates an endogenous instruction arrival process, a scale-free topology of payments between banks, a fixed total liquidity which limits banks’ capacity to process arriving instructions, and a global market that distributes liquidity. We find that at low liquidity the system becomes congested and payment settlement loses correlation with payment instruction arrival, becoming coupled across the network. The onset of congestion is evidently related to the relative values of three characteristic times: the time for banks’ net position to return to 0, the time for a bank to exhaust its liquidity endowment, and the liquidity market relaxation time. In the congested regime settlement takes place in cascades having a characteristic length scale. A global liquidity market substantially attenuates congestion, requiring only a small fraction of the payment-induced liquidity flow to achieve strong beneficial effects.

Treatment of congestion in upper respiratory diseases

Directory of Open Access Journals (Sweden)

Eli O Meltzer

2010-02-01

Full Text Available Eli O Meltzer1, Fernan Caballero2, Leonard M Fromer3, John H Krouse4, Glenis Scadding51Allergy and Asthma Medical Group and Research Center, San Diego, CA and Department of Pediatrics, University of California, San Diego, USA; 2Allergy and Clinical Immunology Service, Centro Medico-Docente La Trinidad, Caracas, Venezuela; 3David Geffen School of Medicine, University of California, Los Angeles, USA; 4Wayne State University School of Medicine, Detroit, Michigan, USA; 5Department of Allergy and Rhinology, Royal National TNE Hospital, London, UKAbstract: Congestion, as a symptom of upper respiratory tract diseases including seasonal and perennial allergic rhinitis, acute and chronic rhinosinusitis, and nasal polyposis, is principally caused by mucosal inflammation. Though effective pharmacotherapy options exist, no agent is universally efficacious; therapeutic decisions must account for individual patient preferences. Oral H1-antihistamines, though effective for the common symptoms of allergic rhinitis, have modest decongestant action, as do leukotriene receptor antagonists. Intranasal antihistamines appear to improve congestion better than oral forms. Topical decongestants reduce congestion associated with allergic rhinitis, but local adverse effects make them unsuitable for long-term use. Oral decongestants show some efficacy against congestion in allergic rhinitis and the common cold, and can be combined with oral antihistamines. Intranasal corticosteroids have broad anti-inflammatory activities, are the most potent long-term pharmacologic treatment of congestion associated with allergic rhinitis, and show some congestion relief in rhinosinusitis and nasal polyposis. Immunotherapy and surgery may be used in some cases refractory to pharmacotherapy. Steps in congestion management include (1 diagnosis of the cause(s, (2 patient education and monitoring, (3 avoidance of environmental triggers where possible, (4 pharmacotherapy, and (5 immunotherapy

Continuous integration congestion cost allocation based on sensitivity

International Nuclear Information System (INIS)

Wu, Z.Q.; Wang, Y.N.

2004-01-01

Congestion cost allocation is a very important topic in congestion management. Allocation methods based on the Aumann-Shapley value use the discrete numerical integration method, which needs to solve the incremented OPF solution many times, and as such it is not suitable for practical application to large-scale systems. The optimal solution and its sensitivity change tendency during congestion removal using a DC optimal power flow (OPF) process is analysed. A simple continuous integration method based on the sensitivity is proposed for the congestion cost allocation. The proposed sensitivity analysis method needs a smaller computation time than the method based on using the quadratic method and inner point iteration. The proposed congestion cost allocation method uses a continuous integration method rather than discrete numerical integration. The method does not need to solve the incremented OPF solutions; which allows it use in large-scale systems. The method can also be used for AC OPF congestion management. (author)

Autonomous Congestion Control in Delay-Tolerant Networks

Science.gov (United States)

Burleigh, Scott; Jennings, Esther; Schoolcraft, Joshua

2006-01-01

This presentation highlights communication congestion control in delay-tolerant networks (DTNs). Large-scale future space exploration will offer complex communication challenges that may be best addressed by establishing a network infrastructure. However, current internet techniques for congestion control are not well suited for operation of a network over interplanetary distances. An alternative, delay-tolerant technique for congestion control in a delay-tolerant network is presented. A simple DTN was constructed and an experimental congestion control mechanism was applied. The mechanism appeared to be effective and each router was able to make its bundle acceptance decisions autonomously. Future research will examine more complex topologies and alternative bundle acceptance rules that might enhance performance.

Distribution Locational Marginal Pricing for Optimal Electric Vehicle Charging Management

DEFF Research Database (Denmark)

Li, Ruoyang; Wu, Qiuwei; Oren, Shmuel S.

2013-01-01

This paper presents an integrated distribution locational marginal pricing (DLMP) method designed to alleviate congestion induced by electric vehicle (EV) loads in future power systems. In the proposed approach, the distribution system operator (DSO) determines distribution locational marginal...... shown that the socially optimal charging schedule can be implemented through a decentralized mechanism where loads respond autonomously to the posted DLMPs by maximizing their individual net surplus...

A Distribution-class Locational Marginal Price (DLMP) Index for Enhanced Distribution Systems

Science.gov (United States)

Akinbode, Oluwaseyi Wemimo

consumption deviated by up to 25 percent when using a real-time price. The superiority of the DLMP is more pronounced when important distribution network conditions are not reflected by contemporary prices. The individual load consumption incentivized by the real-time price deviated by up to 90 percent from the optimal consumption in a congested distribution network. While the DLMP internalizes congestion management, the consumption incentivized by the real-time price caused overloads.

Congestion management considering voltage security of power systems

International Nuclear Information System (INIS)

Esmaili, Masoud; Shayanfar, Heidar Ali; Amjady, Nima

2009-01-01

Congestion in a power network is turned up due to system operating limits. To relieve congestion in a deregulated power market, the system operator pays to market participants, GENCOs and DISCOs, to alter their active powers considering their bids. After performing congestion management, the network may be operated with a low security level because of hitting some flows their upper limit and some voltages their lower limit. In this paper, a novel congestion management method based on the voltage stability margin sensitivities is introduced. Using the proposed method, the system operator so alleviates the congestion that the network can more retain its security. The proposed method not only makes the system more secure after congestion management than other methods already presented for this purpose but also its cost of providing security is lower than the earlier methods. Test results of the proposed method along with the earlier ones on the New-England test system elaborate the efficiency of the proposed method from the viewpoint of providing a better voltage stability margin and voltage profile as well as a lower security cost. (author)

Next Generations of Road Pricing: Social Welfare Enhancing

Directory of Open Access Journals (Sweden)

Omid M. Rouhani

2016-03-01

Full Text Available This paper offers a broad overview of road pricing from a social welfare perspective. I first examine two common objectives of road pricing: congestion management and profit making. My goal is to provide a guideline explaining how to promote a social-welfare-enhancing road pricing scheme. To this end, we should: (i consider and improve public transportation systems by providing more environment-friendly transport options; (ii include tolling profits in our welfare analysis (as opposed to what economists suggest since residents are the real owners of roads not users, and since some users are from outside the region and so might not be excluded from analysis; and (iii search for a holistic approach that takes into account system-wide impacts, disutility to users who change their travel behavior (i.e., switch to public transportation, shift their travel, or do not travel at all, and the impacts on land use, employment, and residents.

An Efficient Traffic Congestion Monitoring System on Internet of Vehicles

Directory of Open Access Journals (Sweden)

Duc-Binh Nguyen

2018-01-01

Full Text Available Existing intelligent transport systems (ITS do not fully consider and resolve accuracy, instantaneity, and compatibility challenges while resolving traffic congestion in Internet of Vehicles (IoV environments. This paper proposes a traffic congestion monitoring system, which includes data collection, segmented structure establishment, traffic-flow modelling, local segment traffic congestion prediction, and origin-destination traffic congestion service for drivers. Macroscopic model-based traffic-flow factors were formalized on the basis of the analysis results. Fuzzy rules-based local segment traffic congestion prediction was performed to determine the traffic congestion state. To enhance prediction efficiency, this paper presents a verification process for minimizing false predictions which is based on the Rankine-Hugoniot condition and an origin-destination traffic congestion service is also provided. To verify the feasibility of the proposed system, a prototype was implemented. The experimental results demonstrate that the proposed scheme can effectively monitor traffic congestion in terms of accuracy and system response time.

Congestion Management Strategies of Real-Time Market

DEFF Research Database (Denmark)

Wang, Qi; Zhang, Chunyu; Ding, Yi

2014-01-01

The high penetration of distributed energy resources (DERs) will significantly challenge the power system operation and control due to their stochastic, intermittent, and fluctuation characteristics. This enhances the difficulty of congestion management of power systems in cross-border electricity...... are introduced with the congestion constraints complied. Pre-Contingency strategy is proposed as the advance preparation for the future congestion, and In-Day re-dispatch is used for regulation. Accordingly, the requirements on facilities considering telemetry and remote control in a fast manner are discussed...

Congestion control for vehicular delay tolerant network routing protocols

OpenAIRE

Oham, Chuka Finbars

2014-01-01

The Vehicular Delay Tolerant Network (VDTN) is a special and challenging type of the Delay Tolerant Network because of its high mobility, frequent disconnections and nodal congestion features. These challenging features make it prone to congestion which leads to a considerable amount of message drops in the network. To minimize the impact of congestion in the network, we designed and implemented the Congestion Aware Spray and Wait (CASaW) routing protocol. We varied the buffer sizes of the no...

Congestion cost allocation method in a pool model

International Nuclear Information System (INIS)

Jung, H.S.; Hur, D.; Park, J.K.

2003-01-01

The congestion cost caused by transmission capacities and voltage limit is an important issue in a competitive electricity market. To allocate the congestion cost equitably, the active constraints in a constrained dispatch and the sequence of these constraints should be considered. A multi-stage method is proposed which reflects the effects of both the active constraints and the sequence. In a multi-stage method, the types of congestion are analysed in order to consider the sequence, and the relationship between congestion and the active constraints is derived in a mathematical way. The case study shows that the proposed method can give more accurate and equitable signals to customers. (Author)

Price responsive load programs: U.S. experience in creating markets for peak demand reductions

International Nuclear Information System (INIS)

Goldberg, Miriam L.; Michelman, Thomas; Rosenberg, Mitchell

2003-01-01

Demand response programs use a variety of pricing mechanisms to induce end-use customers to reduce demand at specified periods. U.S. distribution utilities, regional market operators, and their regulators have implemented demand response programs with the objectives of improving electric system reliability, avoiding price spikes, and relieving local transmission congestion. This paper reviews the design and performance of market-linked demand response programs operated in 2001 and 2002, focusing on the relationship between program design and customer participation and the development of accurate and feasible methods to measure demand response at the facility level

Comparative Study on New AQM Mechanisms for Congestion Control

Directory of Open Access Journals (Sweden)

Ramakrishna B B

2013-09-01

Full Text Available As usage of network goes increasing day by day, managing network traffic becomes a very difficult task. It is important to avoid high packet loss rates in the Internet. Congestion is the one of the major issue in the present networks. Congestion Control is one of the solutions adopted to solve the congestion issue and to control it. Numbers of queue management algorithms are proposed for congestion control and to reduce high packet loss rates. Active Queue Management (AQM is one such mechanism which provides better control over congestion. In this paper a study is made on recent load based AQM techniques that are proposed and its merits and shortfall is presented.

Dynamic voltage stability constrained congestion management framework for deregulated electricity markets

International Nuclear Information System (INIS)

Amjady, Nima; Hakimi, Mahmood

2012-01-01

Highlights: ► A new congestion management method for electricity markets is proposed. ► The proposed method includes dynamic models of generators and loads. ► Dynamic voltage stability limits are properly modeled in the proposed method. ► The proposed method is compared with several other congestion management methods. ► It leads to a more robust power system with a lower congestion management cost. - Abstract: Congestion management is an important part of power system operation in today deregulated electricity markets. However, congestion management is traditionally performed based on static analysis tools, while these tools may not correctly capture dynamic voltage stability limits of a power system. In this paper, a new congestion management framework considering dynamic voltage stability boundary of power system is proposed. For this purpose, precise dynamic modeling of power system equipment, including generators and loads, is incorporated into the proposed congestion management framework. The proposed method alleviates congestion with a lower congestion management cost and more dynamic voltage stability margin, resulting in a more robust power system, compared with the previous congestion management methods. The validity of proposed congestion management framework is studied based on the New England 39-bus power system. The obtained results confirm the validity of the developed approach.

Driving with a congestion assistant : mental workload and acceptance

NARCIS (Netherlands)

Brookhuis, K.A.; Driel, C. J.G. van; Hof, T.; Arem, B. van; Hoedemaeker, M.

2009-01-01

New driver support systems are developed and introduced to the market at increasing speed. In conditions of traffic congestion drivers may be supported by a" Congestion Assistant", a system that combines the features of a Congestion Warning System (acoustic warning and gas pedal counterforce) and a

Busy hour traffic congestion analysis in mobile macrocells | Ozovehe ...

African Journals Online (AJOL)

In this work, real live traffic data from integrated GSM/GPRS network was used for traffic congestion analysis. The analysis was carried out on 10 congesting cells using network management system (NMS) statistics data span for three years period. Correlation test showed that traffic channel (TCH) congestion depend only ...

Measuring accessibility and congestion in Accra

DEFF Research Database (Denmark)

Møller-Jensen, Lasse; Kofie, Richard Y.; Allotey, Albert N.M.

2012-01-01

Based on extensive gps-measurements, the paper addresses the level of intra-urban accessibility and provides indications of the level of congestion in Accra, Ghana. Traffic flows within the urban area are analyzed with respect to speed, time-of-day, direction, road type and land cover type. The s...... and less during off-peak hours. Delays are frequently found within the inner fringe areas. The paper discusses the methodological potentials and barriers for applying gps tracklog points for analysing traffic flows within an urban road network........ The speed information is extrapolated to cover the total mapped urban road net¬work with time- and direction-specific data. A series of time-distance maps are created using network analysis to illustrate the level of accessibility at different times of the day and at different directions relative...... to the city centre. Peak hour traffic speeds are compared with off-peak levels and theoretical free-flow estimations to provide an indica-tion of the level of congestion. It is found that the core areas are somewhat congested during the day period, while the fringe areas are more congested during peak hours...

Quick Link Selection Method by Using Pricing Strategy Based on User Equilibrium for Implementing an Effective Urban Travel Demand Management

Directory of Open Access Journals (Sweden)

Shahriar Afandizadeh Zargari

2016-12-01

Full Text Available This paper presents a two-stage model of optimization as a quick method to choose the best potential links for implementing urban travel demand management (UTDM strategy like road pricing. The model is optimized by minimizing the hidden cost of congestion based on user equilibrium (MHCCUE. It forecasts the exact amount of flows and tolls for links in user equilibrium condition to determine the hidden cost for each link to optimize the link selection based on the network congestion priority. The results show that not only the amount of total cost is decreased, but also the number of selected links for pricing is reduced as compared with the previous toll minimization methods. Moreover, as this model just uses the traffic assignment data for calculation, it could be considered as a quick and optimum solution for choosing the potential links.

Imports, exports, and Alberta's transmission system impact on price fluctuation

International Nuclear Information System (INIS)

Johnson, K.

2002-01-01

The roles, responsibilities and objectives of ESBI, a private for-profit company, appointed by the Alberta Government to be the Independent Transmission Administrator in the province, is sketched, prior to a discussion of price volatility in electricity, Alberta interconnections, intertie issues, the economic theory and the reality impact on prices. Given that imports and exports constitute a relatively small proportion of total generation or load in Alberta, price volatility is considered to have been only minimally affected by imports/exports. In contrast, transmission constraints, i.e. the limits on physical capacity of the existing transmission system to accommodate all desired transactions, have significant impact on imports/exports. Factors underlying constraints and price volatility such as uncertainty of generation dispatch, leading to reduced interest to invest, which in turn leads to scarce capacity for imports/exports, and the actions required to reduce uncertainty and address other issues such as congestion management, tariff design and the creation of regional transmission organizations, are also discussed to provide further clarification of the issues. It is suggested that these and other related issues need to be resolved to provide the clarity around transmission access and the tools required to manage price fluctuations

A NEW CONGESTION MANAGEMENT MECHANISM FOR NEXT GENERATION ROUTERS

Directory of Open Access Journals (Sweden)

MOHAMMED M. KADHUM

2008-12-01

Full Text Available While computer networks go towards dealing with varied traffic types with different service requirements, there is a necessity for modern network control mechanisms that can control the network traffic to meet the users' service requirements. Optimizing the network utilization by improving the network performance can help to accommodate more users and thus increase operators’ profits. Controlling the congestion at the gateway leads to better performance of the network. Sending congestion signal sooner can be of great benefit to the TCP connection. In this paper, we propose Fast Congestion Notification (FCN mechanism which is a new method for managing the gateway queues and fast sending of congestion signal to the sender. We tested our mechanism on Explicit Congestion Notification (ECN packets which have higher priority; we achieved good results in terms of faster congestion signal propagation and better network utilization. Our analysis and simulations results show that the use of FCN over TCP connections sharing one bottleneck can improve the throughput, having less loss, less delay time, and better network utilization.

Endogenous scheduling preferences and congestion

DEFF Research Database (Denmark)

Fosgerau, Mogens; Small, Kenneth

2010-01-01

and leisure, but agglomeration economies at home and at work lead to scheduling preferences forming endogenously. Using bottleneck congestion technology, we obtain an equilibrium queuing pattern consistent with a general version of the Vickrey bottleneck model. However, the policy implications are different....... Compared to the predictions of an analyst observing untolled equilibrium and taking scheduling preferences as exogenous, we find that both the optimal capacity and the marginal external cost of congestion have changed. The benefits of tolling are greater, and the optimal time varying toll is different....

Managing congestion and intermittent renewable generation in liberalized electricity markets

Energy Technology Data Exchange (ETDEWEB)

Kunz, Friedrich

2013-02-27

This dissertation focuses on selected aspects of network congestion arising in liberalized electricity markets and their management methods with a special weight placed on the integration of increased renewable generation in Europe and Germany. In a first step, the theoretical concepts of congestion management are introduced complemented by a review of current management regimes in selected countries. In the second step, the European approach of managing congestion on international as well as national transmission links is analyzed and the benefits of an integrated congestion management regime are quantified. It is concluded that benefits can be achieved by a closer cooperation of national transmission system operators (TSOs). Thirdly, the German congestion management regime is investigated and the impact of higher renewable generation up to 2020 on congestion management cost is determined. It is shown that a homogeneous and jointly development of generation and transmission infrastructure is a prerequisite for the application of congestion alleviation methods and once they diverge congestion management cost tend to increase substantially. Lastly, the impact of intermittent and uncertain wind generation on electricity markets is analyzed. A stochastic electricity market model is described, which replicates the daily subsequent clearing of reserve, day ahead, and intraday market typical for European countries, and numerical results are presented.

A theory of traffic congestion at moving bottlenecks

Energy Technology Data Exchange (ETDEWEB)

Kerner, Boris S [Daimler AG, GR/PTF, HPC: G021, 71059 Sindelfingen (Germany); Klenov, Sergey L, E-mail: boris.kerner@daimler.co [Department of Physics, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Moscow Region (Russian Federation)

2010-10-22

The physics of traffic congestion occurring at a moving bottleneck on a multi-lane road is revealed based on the numerical analyses of vehicular traffic with a discrete stochastic traffic flow model in the framework of three-phase traffic theory. We find that there is a critical speed of a moving bottleneck at which traffic breakdown, i.e. a first-order phase transition from free flow to synchronized flow, occurs spontaneously at the moving bottleneck, if the flow rate upstream of the bottleneck is great enough. The greater the flow rate, the higher the critical speed of the moving bottleneck. A diagram of congested traffic patterns at the moving bottleneck is found, which shows regions in the flow-rate-moving-bottleneck-speed plane in which congested patterns emerge spontaneously or can be induced through large enough disturbances in an initial free flow. A comparison of features of traffic breakdown and resulting congested patterns at the moving bottleneck with known ones at an on-ramp (and other motionless) bottleneck is made. Nonlinear features of complex interactions and transformations of congested traffic patterns occurring at on- and off-ramp bottlenecks due to the existence of the moving bottleneck are found. The physics of the phenomenon of traffic congestion due to 'elephant racing' on a multi-lane road is revealed.

A theory of traffic congestion at moving bottlenecks

International Nuclear Information System (INIS)

Kerner, Boris S; Klenov, Sergey L

2010-01-01

The physics of traffic congestion occurring at a moving bottleneck on a multi-lane road is revealed based on the numerical analyses of vehicular traffic with a discrete stochastic traffic flow model in the framework of three-phase traffic theory. We find that there is a critical speed of a moving bottleneck at which traffic breakdown, i.e. a first-order phase transition from free flow to synchronized flow, occurs spontaneously at the moving bottleneck, if the flow rate upstream of the bottleneck is great enough. The greater the flow rate, the higher the critical speed of the moving bottleneck. A diagram of congested traffic patterns at the moving bottleneck is found, which shows regions in the flow-rate-moving-bottleneck-speed plane in which congested patterns emerge spontaneously or can be induced through large enough disturbances in an initial free flow. A comparison of features of traffic breakdown and resulting congested patterns at the moving bottleneck with known ones at an on-ramp (and other motionless) bottleneck is made. Nonlinear features of complex interactions and transformations of congested traffic patterns occurring at on- and off-ramp bottlenecks due to the existence of the moving bottleneck are found. The physics of the phenomenon of traffic congestion due to 'elephant racing' on a multi-lane road is revealed.

Pricing in M/M/1 queues when cost of waiting in queue differs from cost of waiting in service

Directory of Open Access Journals (Sweden)

Görkem Sarıyer

2016-11-01

Full Text Available Service providers can adjust the entrance price to the state of the demand in real life service systems where the customers' decision to receive the service, is based on this price, state of demand and other system parameters. We analyzed service provider's short and long term pricing problems in unobservable M/M/1 queues having the rational customers, where, for customers, the unit cost of waiting in the queue is higher than unit cost of waiting in the service. We showed that waiting in the queue has a clear negative effect on customers’ utilities, hence the service provider's price values. We also showed that, in the short term, monopolistic pricing is optimal for congested systems with high server utilization levels, whereas in the long term, market capturing pricing is more profitable.

A theory of traffic congestion at heavy bottlenecks

Energy Technology Data Exchange (ETDEWEB)

Kerner, Boris S [Daimler AG, GR/ETI, HPC: G021, 71059 Sindelfingen (Germany)

2008-05-30

Spatiotemporal features and physics of vehicular traffic congestion occurring due to heavy highway bottlenecks caused for example by bad weather conditions or accidents are found based on simulations in the framework of three-phase traffic theory. A model of a heavy bottleneck is presented. Under a continuous non-limited increase in bottleneck strength, i.e., when the average flow rate within a congested pattern allowed by the heavy bottleneck decreases continuously up to zero, the evolution of the traffic phases in congested traffic, synchronized flow and wide moving jams, is studied. It is found that at a small enough flow rate within the congested pattern, the pattern exhibits a non-regular structure: a pinch region of synchronized flow within the pattern disappears and appears randomly over time; wide moving jams upstream of the pinch region exhibit a complex non-regular dynamics in which the jams appear and disappear randomly. At greater bottleneck strengths, wide moving jams merge onto a mega-wide moving jam (mega-jam) within which low-speed patterns with a complex non-regular spatiotemporal dynamics occur. We show that when the bottleneck strength is great enough, only the mega-jam survives and synchronized flow remains only within its downstream front separating free flow and congested traffic. Theoretical results presented can explain why no sequence of wide moving jams can often be distinguished in non-homogeneous traffic congestion measured at very heavy bottlenecks caused by bad weather conditions or accidents.

A theory of traffic congestion at heavy bottlenecks

International Nuclear Information System (INIS)

Kerner, Boris S

2008-01-01

Spatiotemporal features and physics of vehicular traffic congestion occurring due to heavy highway bottlenecks caused for example by bad weather conditions or accidents are found based on simulations in the framework of three-phase traffic theory. A model of a heavy bottleneck is presented. Under a continuous non-limited increase in bottleneck strength, i.e., when the average flow rate within a congested pattern allowed by the heavy bottleneck decreases continuously up to zero, the evolution of the traffic phases in congested traffic, synchronized flow and wide moving jams, is studied. It is found that at a small enough flow rate within the congested pattern, the pattern exhibits a non-regular structure: a pinch region of synchronized flow within the pattern disappears and appears randomly over time; wide moving jams upstream of the pinch region exhibit a complex non-regular dynamics in which the jams appear and disappear randomly. At greater bottleneck strengths, wide moving jams merge onto a mega-wide moving jam (mega-jam) within which low-speed patterns with a complex non-regular spatiotemporal dynamics occur. We show that when the bottleneck strength is great enough, only the mega-jam survives and synchronized flow remains only within its downstream front separating free flow and congested traffic. Theoretical results presented can explain why no sequence of wide moving jams can often be distinguished in non-homogeneous traffic congestion measured at very heavy bottlenecks caused by bad weather conditions or accidents

Power transmission charges based on nodal pricing which considers restriction on power transmission; Soden setsuyaku wo koryoshita nodaru pricing ni motozuku soden ryokin

Energy Technology Data Exchange (ETDEWEB)

Okada, K.; Asano, H. [Central Research Institute of Electric Power Industry, Tokyo (Japan); Matsukawa, I. [Musashi University, Tokyo (Japan)

1997-01-30

Power transmission charges were derived by using nodal pricing, and a discussion was given on what effects are given on system conditions, nodal price and consignment charge by how coordination points of independent power producers (IPP) and power demand are handled. A test model having six nodes (busbars) and eleven branches (transmission lines) was used. Since demands of the same kind are hypothesized to be coordinated in this simulation, the total nodal price becomes an equivalent value if there is no restrictions in transmission line current. If the transmission restrictions are taken into consideration, demand amounts at each node are so adjusted that excess current in a transmission line exceeding the transmission capacity will be eliminated. Thus, the demand-supply balancing amount in the entire system becomes smaller than when restrictions are not considered. As a result of the analysis, the IPP coordination points have possibilities to cause congestion (overload current) in the system, raise nodal price at each point, and sharply raise the consignment charge. It was found that an effect may also occur to a node depending on position of demand generation. 6 refs., 3 figs., 7 tabs.

The impact of a congestion assistant on traffic flow efficiency and safety in congested traffic caused by a lane drop

NARCIS (Netherlands)

van Driel, Cornelie; van Arem, Bart

2010-01-01

This article presents the results of a microscopic traffic simulation study conducted to investigate the impact of a Congestion Assistant on traffic efficiency and traffic safety. The Congestion Assistant is an in-vehicle system in which an active pedal supports the driver when approaching

Evaluating congestion management in the Dutch electricity transmission grid

International Nuclear Information System (INIS)

Blijswijk, Martti J. van; Vries, Laurens J. de

2012-01-01

Due to the increase in electricity generation capacity in the Netherlands and a new connection policy, transmission system operator (TSO) TenneT expects a significant increase in congestion in the Dutch transmission grid. To manage this, the Dutch government implemented redispatching, a method which is argued in the literature to potentially impose large congestion costs upon the TSO. A quantitative model of the Dutch electricity system was developed in order to evaluate this method. The outcomes were compared to the performance of three alternative congestion management methods. Regardless of the method, congestion costs were found to be substantially lower than in previous studies. Because combined-cycle gas turbines are the marginal generation technology in almost all cases, the costs of up and down regulation do not differ much. Consequently, the redispatching costs for the TSO are expected to be relatively low, and the opportunities for abuse of market power appear to be limited. While all the evaluated methods are effective and economically efficient, they have significantly different welfare effects. Market splitting creates significantly larger welfare effects than the different varieties of redispatching. - Highlights: ► Congestion management was recently introduced in the Netherlands. ► We quantitatively evaluate the effects of its application. ► We compare this to other congestion management methods. ► Given the specific situation that the marginal cost curve of production is flat, congestion costs are expected to be low.

The economic cost of traffic congestion in Florida.

Science.gov (United States)

2010-08-01

Traffic congestion in the U.S. is bad and getting worse, and it is expensive. Appropriate solutions to this problem require appropriate information. A comprehensive and accurate analysis of congestion costs is a critical tool for planning and impleme...

23 CFR 970.214 - Federal lands congestion management system (CMS).

Science.gov (United States)

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Federal lands congestion management system (CMS). 970....214 Federal lands congestion management system (CMS). (a) For purposes of this section, congestion...) Develop criteria to determine when a CMS is to be implemented for a specific transportation system; and (2...

23 CFR 972.214 - Federal lands congestion management system (CMS).

Science.gov (United States)

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Federal lands congestion management system (CMS). 972... § 972.214 Federal lands congestion management system (CMS). (a) For purposes of this section, congestion... interference. For those FWS transportation systems that require a CMS, in both metropolitan and non...

Diagnosis and management of nasal congestion: the role of intranasal corticosteroids.

Science.gov (United States)

Benninger, Michael

2009-01-01

Nasal congestion is considered the most bothersome of allergic rhinitis (AR) symptoms and can significantly impair ability to function at work, home, and school. Effective management of AR-related nasal congestion depends on accurate diagnosis and appropriate treatment. Many individuals with AR and AR-related congestion remain undiagnosed and do not receive prescription medication. However, new tools intended to improve the diagnosis of nasal congestion have been developed and validated. Intranasal corticosteroids (INSs) are recommended as first-line therapy for patients with moderate-to-severe AR and also when nasal congestion is a prominent symptom. Double blind, randomized clinical trials have demonstrated greater efficacy of INSs versus placebo, antihistamines, or montelukast for relief of all nasal symptoms, especially congestion. Patient adherence to treatment also affects outcomes, and this may be influenced by patient preferences for the sensory attributes of an individual drug. Increased awareness of the effects of AR-related nasal congestion, the efficacy and safety of available pharmacotherapies, and barriers to adherence may improve clinical outcomes.

A Trial-and-Error Method with Autonomous Vehicle-to-Infrastructure Traffic Counts for Cordon-Based Congestion Pricing

Directory of Open Access Journals (Sweden)

Zhiyuan Liu

2017-01-01

Full Text Available This study proposes a practical trial-and-error method to solve the optimal toll design problem of cordon-based pricing, where only the traffic counts autonomously collected on the entry links of the pricing cordon are needed. With the fast development and adoption of vehicle-to-infrastructure (V2I facilities, it is very convenient to autonomously collect these data. Two practical properties of the cordon-based pricing are further considered in this article: the toll charge on each entry of one pricing cordon is identical; the total inbound flow to one cordon should be restricted in order to maintain the traffic conditions within the cordon area. Then, the stochastic user equilibrium (SUE with asymmetric link travel time functions is used to assess each feasible toll pattern. Based on a variational inequality (VI model for the optimal toll pattern, this study proposes a theoretically convergent trial-and-error method for the addressed problem, where only traffic counts data are needed. Finally, the proposed method is verified based on a numerical network example.

Exploring spatio-temporal patterns in traffic congestion data

DEFF Research Database (Denmark)

Kveladze, Irma; Agerholm, Niels; Reinau, Kristian Hegner

2017-01-01

An efficient infrastructure is essential for economic development. However, economic growth has been closely connected to the increasing road transport. This increases traffic congestions significantly, and road network gets near or at its capacity limits. Hence, congestion has become a central...

Multi-objective congestion management by modified augmented ε-constraint method

International Nuclear Information System (INIS)

Esmaili, Masoud; Shayanfar, Heidar Ali; Amjady, Nima

2011-01-01

Congestion management is a vital part of power system operations in recent deregulated electricity markets. However, after relieving congestion, power systems may be operated with a reduced voltage or transient stability margin because of hitting security limits or increasing the contribution of risky participants. Therefore, power system stability margins should be considered within the congestion management framework. The multi-objective congestion management provides not only more security but also more flexibility than single-objective methods. In this paper, a multi-objective congestion management framework is presented while simultaneously optimizing the competing objective functions of congestion management cost, voltage security, and dynamic security. The proposed multi-objective framework, called modified augmented ε-constraint method, is based on the augmented ε-constraint technique hybridized by the weighting method. The proposed framework generates candidate solutions for the multi-objective problem including only efficient Pareto surface enhancing the competitiveness and economic effectiveness of the power market. Besides, the relative importance of the objective functions is explicitly modeled in the proposed framework. Results of testing the proposed multi-objective congestion management method on the New-England test system are presented and compared with those of the previous single objective and multi-objective techniques in detail. These comparisons confirm the efficiency of the developed method. (author)

23 CFR 971.214 - Federal lands congestion management system (CMS).

Science.gov (United States)

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Federal lands congestion management system (CMS). 971... Federal lands congestion management system (CMS). (a) For purposes of this section, congestion means the...) Develop criteria to determine when a CMS is to be implemented for a specific FH; and (2) Have CMS coverage...

Avoiding congestion in recommender systems

International Nuclear Information System (INIS)

Ren, Xiaolong; Lü, Linyuan; Liu, Runran; Zhang, Jianlin

2014-01-01

Recommender systems use the historical activities and personal profiles of users to uncover their preferences and recommend objects. Most of the previous methods are based on objects’ (and/or users’) similarity rather than on their difference. Such approaches are subject to a high risk of increasingly exposing users to a narrowing band of popular objects. As a result, a few objects may be recommended to an enormous number of users, resulting in the problem of recommendation congestion, which is to be avoided, especially when the recommended objects are limited resources. In order to quantitatively measure a recommendation algorithm's ability to avoid congestion, we proposed a new metric inspired by the Gini index, which is used to measure the inequality of the individual wealth distribution in an economy. Besides this, a new recommendation method called directed weighted conduction (DWC) was developed by considering the heat conduction process on a user–object bipartite network with different thermal conductivities. Experimental results obtained for three benchmark data sets showed that the DWC algorithm can effectively avoid system congestion, and greatly improve the novelty and diversity, while retaining relatively high accuracy, in comparison with the state-of-the-art methods. (paper)

First-order, stationary mean-field games with congestion

KAUST Repository

Evangelista, David

2018-04-30

Mean-field games (MFGs) are models for large populations of competing rational agents that seek to optimize a suitable functional. In the case of congestion, this functional takes into account the difficulty of moving in high-density areas. Here, we study stationary MFGs with congestion with quadratic or power-like Hamiltonians. First, using explicit examples, we illustrate two main difficulties: the lack of classical solutions and the existence of areas with vanishing densities. Our main contribution is a new variational formulation for MFGs with congestion. With this formulation, we prove the existence and uniqueness of solutions. Finally, we consider applications to numerical methods.

First-order, stationary mean-field games with congestion

KAUST Repository

Evangelista, David; Ferreira, Rita; Gomes, Diogo A.; Nurbekyan, Levon; Voskanyan, Vardan K.

2018-01-01

Mean-field games (MFGs) are models for large populations of competing rational agents that seek to optimize a suitable functional. In the case of congestion, this functional takes into account the difficulty of moving in high-density areas. Here, we study stationary MFGs with congestion with quadratic or power-like Hamiltonians. First, using explicit examples, we illustrate two main difficulties: the lack of classical solutions and the existence of areas with vanishing densities. Our main contribution is a new variational formulation for MFGs with congestion. With this formulation, we prove the existence and uniqueness of solutions. Finally, we consider applications to numerical methods.

Stochastic congestion management in power markets using efficient scenario approaches

International Nuclear Information System (INIS)

Esmaili, Masoud; Amjady, Nima; Shayanfar, Heidar Ali

2010-01-01

Congestion management in electricity markets is traditionally performed using deterministic values of system parameters assuming a fixed network configuration. In this paper, a stochastic programming framework is proposed for congestion management considering the power system uncertainties comprising outage of generating units and transmission branches. The Forced Outage Rate of equipment is employed in the stochastic programming. Using the Monte Carlo simulation, possible scenarios of power system operating states are generated and a probability is assigned to each scenario. The performance of the ordinary as well as Lattice rank-1 and rank-2 Monte Carlo simulations is evaluated in the proposed congestion management framework. As a tradeoff between computation time and accuracy, scenario reduction based on the standard deviation of accepted scenarios is adopted. The stochastic congestion management solution is obtained by aggregating individual solutions of accepted scenarios. Congestion management using the proposed stochastic framework provides a more realistic solution compared with traditional deterministic solutions. Results of testing the proposed stochastic congestion management on the 24-bus reliability test system indicate the efficiency of the proposed framework.

Transvaginal ultrasound examination of women with and without pelvic venous congestion

International Nuclear Information System (INIS)

Halligan, Steve; Campbell, Deidre; Bartram, Clive I.; Rogers, Vera; El-Haddad, Cadria; Patel, Sujata; Beard, Richard W.

2000-01-01

AIM: To determine if transvaginal ultrasound, including power Doppler examination, can distinguish between women with and without pelvic congestion. MATERIALS AND METHODS: Thirty-six women with pelvic congestion were prospectively examined using transvaginal ultrasonography and standard uterine and ovarian measurements made. Additionally, planimetric measurements of each ovary were taken using an image analysis program to determine the cross-sectional area of ovarian stroma and follicles, if any. Power Doppler images of adnexal vessels were obtained and planimetric estimates of surface area calculated. A congestion score was assigned to each patient, based on vein number, diameter and morphology on grey-scale scanning. Identical measurements were obtained from 19 asymptomatic women and results compared. RESULTS: There was no significant difference between women with pelvic congestion and controls with respect to power Doppler or grey-scale images of adnexal vessels, or congestion score. However, women with pelvic congestion had significantly larger and multicystic ovaries when compared to controls. CONCLUSIONS: Transvaginal ultrasound measurements of adnexal vasculature, including power Doppler measurements, cannot reliably distinguish women with pelvic congestion from controls. However, ultrasound may remain useful for diagnosis of pelvic congestion, predominantly because it is able to visualize multi-cystic ovaries in these patients. Halligan, S. (2000).Clinical Radiology 55 , 954-958

A NEW PREDICTIVE MODEL FOR CONGESTION CONTROL IN WIRELESS SENSOR NETWORKS

Directory of Open Access Journals (Sweden)

NAJME TANZADE PANAH

2017-06-01

Full Text Available With the increase of various applications in the domain of wireless sensor networks, the tendency to use wireless sensors has gradually increased in different applications. On the other hand, diverse traffic with different priorities generated by these sensors requires providing adaptive quality of services based on users` needs. In this paper, a congestion control predictor model is proposed for wireless sensor networks, which considers parameters like network energy consumption, packet loss rate and percentage of delivered high and medium priority packets to the destination. This method consists of congestion prevention, congestion control, and energy control plans using shortest path selection algorithm. In the congestion prevention plan, congestion is prevented by investigating the queues length. In the congestion control plan, the congestion is controlled by reducing the transmission rate. Finally, the energy control plan aims to partially balance the energy of nodes to prevent network failures due to node energy outage. Simulation results indicated that the proposed method has a higher efficiency regarding the aforementioned parameters. In addition, comparisons with other well-known methods showed the effectiveness of the proposed method.

Locational Prices in Capacity Subscription Market Considering Transmission Limitations

Directory of Open Access Journals (Sweden)

S. Babaeinejad Sarookolaee

2013-06-01

Full Text Available This study focuses on one of the most effective type of capacity markets named Capacity Subscription (CS market which is predicted to be widely used in the upcoming smart grids. Despite variant researches done about the mechanism and structure of capacity markets, their performances have been rarely tested in the presence of network constraints. Considering this deficiency, we tried to propose a new method to determine capacity prices in the network considering the transmission line flow limitations named Local capacity Prices (LP. This method is quite new and has not been tried before in any other similar researches. The philosophy of the proposed method is to determine capacity prices considering each consumer share of total peak demand. The first advantage of LP is that the consumers who benefit from the transmission facilities and are the responsible for transmission congestions, pay higher capacity prices than those whom their needed electricity is prepared locally. The second advantage of LP is that consumers connected to the same bus do not have to pay same capacity price due to their different shares of total peak demand. For more clarification, two other different methods named Branches Flow limit as a Global Limit (BFGL and Locational Capacity Prices (LCP are proposed and compared to the LP method in order to show LP method efficiency. The numerical results obtained from case studies show that the LP method follows more justice market procedure which results in more efficient capacity prices in comparison to BFGL and LCP methods.

Statewide GIS mapping of recurring congestion corridors : final report.

Science.gov (United States)

2009-07-01

Recurring congestion occurs when travel demand reaches or exceeds the available roadway : capacity. This project developed an interactive geographic information system (GIS) map of the : recurring congestion corridors (labeled herein as hotspots) in ...

Fair decentralized data-rate congestion control for V2V communications

NARCIS (Netherlands)

Belagal Math, C.; Li, H.; Heemstra De Groot, S.M.; Niemegeers, I.G.M.M.

2017-01-01

Channel congestion is one of the most critical issues in IEEE 802.11p-based vehicular ad hoc networks because congestion may lead to unreliability of applications. As a counter measure, the European Telecommunications Standard Institute (ETSI), proposes a mandatory Decentralized Congestion Control

Congested Link Inference Algorithms in Dynamic Routing IP Network

Directory of Open Access Journals (Sweden)

Yu Chen

2017-01-01

Full Text Available The performance descending of current congested link inference algorithms is obviously in dynamic routing IP network, such as the most classical algorithm CLINK. To overcome this problem, based on the assumptions of Markov property and time homogeneity, we build a kind of Variable Structure Discrete Dynamic Bayesian (VSDDB network simplified model of dynamic routing IP network. Under the simplified VSDDB model, based on the Bayesian Maximum A Posteriori (BMAP and Rest Bayesian Network Model (RBNM, we proposed an Improved CLINK (ICLINK algorithm. Considering the concurrent phenomenon of multiple link congestion usually happens, we also proposed algorithm CLILRS (Congested Link Inference algorithm based on Lagrangian Relaxation Subgradient to infer the set of congested links. We validated our results by the experiments of analogy, simulation, and actual Internet.

Addressing congestion on single allocation hub-and-spoke networks

Directory of Open Access Journals (Sweden)

Ricardo Saraiva de Camargo

2012-12-01

Full Text Available When considering hub-and-spoke networks with single allocation, the absence of alternative routes makes this kind of systems specially vulnerable to congestion effects. In order to improve the design of such networks, congestion costs must be addressed. This article deploys two different techniques for addressing congestion on single allocation hub-and-spoke networks: the Generalized Benders Decomposition and the Outer Approximation method. Both methods are able to solve large scale instances. Computational experiments show how the adoption of advanced solution strategies, such as Pareto-optimal cut generation on the Master Problem branch-and-bound tree, may be decisive. They also demonstrate that the solution effort is not only associated with the size of the instances, but also with their combination of the installation and congestion costs.

CONGESTION AS A RESULT OF SCHOOL AND SHOPPING CENTER ACTIVITY

Directory of Open Access Journals (Sweden)

Meike Kumaat

2015-12-01

Full Text Available Development of land use in public facilities such as shopping center and school gives an impact on transportation problem in Manado City, North Sulawesi.  To determine factors which have causal relationship with congestion  as a result of school and shopping center activity then it need to be assessed and studied.  Descriptive study with observational survey was used in this study. The study ran Structural Equation Modelling (SEM by using AMOS program. Estimated method was used to calculate sample size then found 300 repondents, comprised : visitors and mall managers, school visitors, parents, school managers, Public Works department, and urban planning department .The study yielded a statistically significant correlation between  school and shopping center activity with congestion s. The result  indicated that school activity was positively related to congestion with p value  at p=0,000 (p ≤ 0,05. Shopping center activity was positively related to congestion with p value  at p=0,000 (p ≤ 0,05. The closer proximity from school to shooping center will causes severe traffic congestion. The relationship between school facility with proximity was found in p value at  p=0,000 (p ≤ 0,05 . The relationship between shopping center facility with proximity was found in p value at  p= 0,020 (p ≤ 0,05. While, the relationship between proximity with congestion was p= 0,008 (p ≤ 0,05. Monastery school and Mega Mall activity were affecting congestion because a closer proximity of two facilities. This indicates that the occurence of traffic congestion in Monastery School  may be dependent on existence of  Piere Tendean road link

Local empathy provides global minimization of congestion in communication networks

Science.gov (United States)

Meloni, Sandro; Gómez-Gardeñes, Jesús

2010-11-01

We present a mechanism to avoid congestion in complex networks based on a local knowledge of traffic conditions and the ability of routers to self-coordinate their dynamical behavior. In particular, routers make use of local information about traffic conditions to either reject or accept information packets from their neighbors. We show that when nodes are only aware of their own congestion state they self-organize into a hierarchical configuration that delays remarkably the onset of congestion although leading to a sharp first-order-like congestion transition. We also consider the case when nodes are aware of the congestion state of their neighbors. In this case, we show that empathy between nodes is strongly beneficial to the overall performance of the system and it is possible to achieve larger values for the critical load together with a smooth, second-order-like, transition. Finally, we show how local empathy minimize the impact of congestion as much as global minimization. Therefore, here we present an outstanding example of how local dynamical rules can optimize the system’s functioning up to the levels reached using global knowledge.

Traffic Congestion Detection and Avoidance using Vehicular Communication

Directory of Open Access Journals (Sweden)

Ajay Narendrabhai Upadhyaya

2015-01-01

Full Text Available Traffic congestion is a serious problem in big cities. With the number of vehicles increasing rapidly, especially in cities whose economy is booming, the situation is getting even worse. Drivers, unaware of congestion ahead eventually join it and increase the severity of it. The ability of a driver to know the traffic conditions on the roads ahead enables him/her to seek alternate routes through which time and fuel can be saved. Due to recent advancements in vehicular technologies, vehicular communication has emerged. The objective of this work is to check feasibility of using infrastructure based vehicular communication for detecting and avoiding traffic congestion. In this paper we propose a Signal Agent (SA and Car Agent(CAbased approach for detecting and avoiding traffic congestion. We analyze performance of the proposed approach for two different road network scenarios using simulations: structured grid network (like Gandhinagar City of Gujarat, India and apart of typical city road network ( Tiwan city. With the proposed approach we get reduction of 10.05% in trip duration of vehicles, reduction of 10.08% in number of vehicles in entire traffic road network and 9.82% in heavy traffic area. In an accident scenario, about 72.63% vehicles changed their route due to awareness of congestion. Error in trip time estimation and vehicle count estimation is observed to be less than 1%.

23 CFR 450.320 - Congestion management process in transportation management areas.

Science.gov (United States)

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Congestion management process in transportation... Programming § 450.320 Congestion management process in transportation management areas. (a) The transportation planning process in a TMA shall address congestion management through a process that provides for safe and...

Transmission Congestion Management using a Wind Integrated Compressed Air Energy Storage System

Directory of Open Access Journals (Sweden)

S. Gope

2017-08-01

Full Text Available Transmission congestion is a vital problem in the power system security and reliability sector. To ensure the stable operation of the system, a congestion free power network is desirable. In this paper, a new Congestion Management (CM technique, the Wind integrated Compressed Air Energy Storage (WCAES system is used to alleviate transmission congestion and to minimize congestion mitigation cost. The CM problem has been solved by using the Generator Sensitivity Factor (GSF and the Bus Sensitivity Factor (BSF. BSF is used for finding the optimal location of WCAES in the system. GSF with a Moth Flame Optimization (MFO algorithm is used for rescheduling the generators to alleviate congestion and to minimize congestion cost by improving security margin. The impact of the WCAES system is tested with a 39 bus system. To validate this approach, the same problem has been solved with a Particle Swarm Optimization (PSO algorithm and the obtained results are compared with the ones from the MFO algorithm.

A Nodal Pricing Analysis of the Future German Electricity Market

International Nuclear Information System (INIS)

Ozdemir, O.; Hers, J.S.; Bartholomew Fisher, E.; Brunekreeft, G.; Hobbs, B.F.

2009-05-01

The electricity market in Germany is likely to undergo several significant structural changes over the years to come. Here one may think of Germany's ambitious renewable agenda, the disputed decommissioning of nuclear facilities, but also unbundling of TSO's as enforced by European regulation. This study is a scenario-based analysis of the impact of different realizations of known investment plans for transmission and generation capacity on the future German power market while accounting for internal congestion. For this analysis the static equilibrium model of the European electricity market COMPETES is deployed, including a 10-node representation of the German highvoltage grid. Results for the multi-node analysis indicate that price divergence and congestion are likely to arise in the German market as renewable additions affecting mainly the North of Germany, the debated decommissioning of nuclear facilities in the South, and the expected decommissioning of coal-fired facilities in Western Germany appear to render current investment plans for transmission capacity insufficient. The current system of singlezone pricing for the German market may therewith be compromised. However, transmission additions would not benefit all market parties, with producers in exporting regions and consumers in importing regions being the main beneficiaries. Vertical unbundling of German power companies could increase the incentive for constructing transmission lines if generation capacity would cause Germany to be a net-importing country. In case Germany remains a net-exporting country, the effects of vertical unbundling on cross-border capacity are less clear cut.

Phasing in wind-power in Norway: Network congestion and crowding-out of hydropower

International Nuclear Information System (INIS)

Forsund, Finn R.; Singh, Balbir; Jensen, Trond; Larsen, Cato

2008-01-01

The objective of this paper is to investigate the effects on utilisation of existing hydropower in a region of investing in significant wind-power in the region within the present network. Policy simulations are conducted using a dynamic system-wide model that is calibrated to reflect the structure of the Nordic power market. This model is the one used by the Norwegian electricity regulator and large hydropower companies in Norway for scheduling of hydro and market analyses. Simulations are carried out for different inflow situations based on past observations going back 60 years. Introduction of wind-power leads to significant increase in network congestion in the region, lower hydropower production, higher level of storage, increased spillage of water, and considerably lower price level in the local region in question

A Novel Congestion Detection Scheme in TCP Over OBS Networks

KAUST Repository

Shihada, Basem

2009-02-01

This paper introduces a novel congestion detection scheme for high-bandwidth TCP flows over optical burst switching (OBS) networks, called statistical additive increase multiplicative decrease (SAIMD). SAIMD maintains and analyzes a number of previous round-trip time (RTTs) at the TCP senders in order to identify the confidence with which a packet loss event is due to network congestion. The confidence is derived by positioning short-term RTT in the spectrum of long-term historical RTTs. The derived confidence corresponding to the packet loss is then taken in the developed policy for TCP congestion window adjustment. We will show through extensive simulation that the proposed scheme can effectively solve the false congestion detection problem and significantly outperform the conventional TCP counterparts without losing fairness. The advantages gained in our scheme are at the expense of introducing more overhead in the SAIMD TCP senders. Based on the proposed congestion control algorithm, a throughput model is formulated, and is further verified by simulation results.

Congestion Quantification Using the National Performance Management Research Data Set

Directory of Open Access Journals (Sweden)

Virginia P. Sisiopiku

2017-11-01

Full Text Available Monitoring of transportation system performance is a key element of any transportation operation and planning strategy. Estimation of dependable performance measures relies on analysis of large amounts of traffic data, which are often expensive and difficult to gather. National databases can assist in this regard, but challenges still remain with respect to data management, accuracy, storage, and use for performance monitoring. In an effort to address such challenges, this paper showcases a process that utilizes the National Performance Management Research Data Set (NPMRDS for generating performance measures for congestion monitoring applications in the Birmingham region. The capabilities of the relational database management system (RDBMS are employed to manage the large amounts of NPMRDS data. Powerful visual maps are developed using GIS software and used to illustrate congestion location, extent and severity. Travel time reliability indices are calculated and utilized to quantify congestion, and congestion intensity measures are developed and employed to rank and prioritize congested segments in the study area. The process for managing and using big traffic data described in the Birmingham case study is a great example that can be replicated by small and mid-size Metropolitan Planning Organizations to generate performance-based measures and monitor congestion in their jurisdictions.

Identifying the Onset of Congestion Rapidly with Existing Traffic Detectors

OpenAIRE

Coifman, Benjamin

1999-01-01

From an operations standpoint, the most important task of a traffic surveillance system is determining reliably whether the facility is free flowing or congested. The second most important task is responding rapidly when the facility becomes congested. Other tasks, such as quantifying the magnitude of congestion, are desirable, but tertiary. To address the first two tasks, this paper presents a new approach for traffic surveillance using existing detectors. Rather than expending a considerabl...

Developing Policy for Urban Autonomous Vehicles: Impact on Congestion

Directory of Open Access Journals (Sweden)

David Metz

2018-04-01

Full Text Available An important problem for surface transport is road traffic congestion, which is ubiquitous and difficult to mitigate. Accordingly, a question for policymakers is the possible impact on congestion of autonomous vehicles. It seems likely that the main impact of vehicle automation will not be seen until driverless vehicles are sufficiently safe for use amid general traffic on urban streets. Shared use driverless vehicles could reduce the cost of taxis and a wider range of public transport vehicles could be economic. Individually owned autonomous vehicles would have the ability to travel unoccupied and may need to be regulated where this might add to congestion. It is possible that autonomous vehicles could provide mobility services at lower cost and wider scope, such that private car use in urban areas could decline and congestion reduce. City authorities should be alert to these possibilities in developing transport policy.

Desk Congest Desktop Congesting Software for Desktop Clutter Congestion

Directory of Open Access Journals (Sweden)

Solomon A. Adepoju

2015-06-01

Full Text Available Abstract The computer desktop environment is a working environment which can be likened unto a users desk in homes and offices. Often times the computer desktop get cluttered with files either as shortcuts used for quick links files stored temporarily to be accessed later or just being dumped there for no vivid reasons. However previous researches have shown that cluttered desktop affects users productivity and getting these files organized is a laborious task for most users. To be able to conveniently alleviate the effect clutters have on users performances and productivity there is need for third party software that will help get the desktop environment organized in a logical and efficient manner. It is to this end that desktop decongesting software is being designed and implemented to help curb clutter problems which existing tools have only partially addressed. The system is designed using Visual Basic .Net and it proves to be effective in tackling desktop congestion problem.

Statewide planning scenario synthesis : transportation congestion measurement and management.

Science.gov (United States)

2005-09-01

This study is a review of current practices in 13 states to: (1) measure traffic congestion and its costs; and (2) manage congestion with programs and techniques that do not involve the building of new highway capacity. In regard to the measures of c...

Fair and efficient network congestion control based on minority game

Science.gov (United States)

Wang, Zuxi; Wang, Wen; Hu, Hanping; Deng, Zhaozhang

2011-12-01

Low link utility, RTT unfairness and unfairness of Multi-Bottleneck network are the existing problems in the present network congestion control algorithms at large. Through the analogy of network congestion control with the "El Farol Bar" problem, we establish a congestion control model based on minority game(MG), and then present a novel network congestion control algorithm based on the model. The result of simulations indicates that the proposed algorithm can make the achievements of link utility closing to 100%, zero packet lose rate, and small of queue size. Besides, the RTT unfairness and the unfairness of Multi-Bottleneck network can be solved, to achieve the max-min fairness in Multi-Bottleneck network, while efficiently weaken the "ping-pong" oscillation caused by the overall synchronization.

Involvement of systemic venous congestion in heart failure.

Science.gov (United States)

Rubio Gracia, J; Sánchez Marteles, M; Pérez Calvo, J I

2017-04-01

Systemic venous congestion has gained significant importance in the interpretation of the pathophysiology of acute heart failure, especially in the development of renal function impairment during exacerbations. In this study, we review the concept, clinical characterisation and identification of venous congestion. We update current knowledge on its importance in the pathophysiology of acute heart failure and its involvement in the prognosis. We pay special attention to the relationship between abdominal congestion, the pulmonary interstitium as filtering membrane, inflammatory phenomena and renal function impairment in acute heart failure. Lastly, we review decongestion as a new therapeutic objective and the measures available for its assessment. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.

Towards Scalable Distributed Framework for Urban Congestion Traffic Patterns Warehousing

Directory of Open Access Journals (Sweden)

A. Boulmakoul

2015-01-01

Full Text Available We put forward architecture of a framework for integration of data from moving objects related to urban transportation network. Most of this research refers to the GPS outdoor geolocation technology and uses distributed cloud infrastructure with big data NoSQL database. A network of intelligent mobile sensors, distributed on urban network, produces congestion traffic patterns. Congestion predictions are based on extended simulation model. This model provides traffic indicators calculations, which fuse with the GPS data for allowing estimation of traffic states across the whole network. The discovery process of congestion patterns uses semantic trajectories metamodel given in our previous works. The challenge of the proposed solution is to store patterns of traffic, which aims to ensure the surveillance and intelligent real-time control network to reduce congestion and avoid its consequences. The fusion of real-time data from GPS-enabled smartphones integrated with those provided by existing traffic systems improves traffic congestion knowledge, as well as generating new information for a soft operational control and providing intelligent added value for transportation systems deployment.

Mapping of selected markets with Nodal pricing or similar systems. Australia, New Zealand and North American power markets

Energy Technology Data Exchange (ETDEWEB)

Mathiesen, Vivi (ed.)

2011-07-01

This report shows that the principals of nodal pricing can be implemented in different ways. A common denominator for markets with nodal pricing is a central market based nodal dispatch, where prices and flows are determined simultaneously close to real time. This stands apart from the European market design, which is based on a highly simplified version of the grid, and a physical point auction day ahead. Congestion management is handled by the TSO during the operational hour and not through the market as is the case in nodal pricing systems. Nodal pricing yields optimal dispatch and congestion management through the market, and as such an optimal utilisation of energy generation and network. However, whether this short term optimisation delivers the highest overall efficiency for the market in terms of competition in the wholesale and retail market, price discovery, possibilities for hedging, long term price signals etc. is difficult to determine. The markets investigated handle issues such as market power, risk management, investment signals and retail markets in very different ways. New Zealand and PJM are examples of markets with full nodal pricing, i.e. both generators and the demand side are exposed to nodal prices. The PJM market has more 'additional features' than the New Zealand market. Examples of these are separate capacity market to trigger investments in generation and generator price caps to deal with situations of market power. In addition PJM offers liquid and mature markets for risk management, such as aggregates of nodes where market participant can chose to be settled (rather than to be settled directly at the node). A general finding though, seems to be that risk management at peripheral nodes is challenging in nodal markets, particularly for independent retailers. In New Zealand generators and retailers were permitted to 'reintegrate' in order to cope with the nodal prices. The Australian market has central market based

Congestion management enhancing transient stability of power systems

International Nuclear Information System (INIS)

Esmaili, Masoud; Shayanfar, Heidar Ali; Amjady, Nima

2010-01-01

In a competitive electricity market, where market parties try to maximize their profits, it is necessary to keep an acceptable level of power system security to retain the continuity of electricity services to customers at a reasonable cost. Congestion in a power system is turned up due to network limits. After relieving congestion, the network may be operated with a reduced transient stability margin because of increasing the contribution of risky participants. In this paper, a novel congestion management method based on a new transient stability criterion is introduced. Using the sensitivity of corrected transient stability margin with respect to generations and demands, the proposed method so alleviates the congestion that the network can more retain its transient security compared with earlier methods. The proposed transient stability index is constructed considering the likelihood of credible faults. Indeed, market parties participate by their security-effective bids rather than raw bids. Results of testing the proposed method along with the earlier ones on the New-England test system elaborate the efficiency of the proposed method from the viewpoint of providing a better transient stability margin with a lower security cost. (author)

Is an inefficient transmission market better than none at all? On zonal and nodal pricing in electricity systems

Energy Technology Data Exchange (ETDEWEB)

Bertsch, Joachim

2015-09-15

In this paper, the trade-off between inefficient transmission forward markets (in nodal pricing regimes) and the inefficiency induced by hiding transmission constraints from the market (in zonal pricing regimes) is analyzed. First, a simple two node model formalizing the general trade-off is developed. Then, comparative statics are performed with a stochastic equilibrium model including more nodes, loop flows and an energy and transmission forward market. Inefficiency in the transmission forward market is introduced via a bid-ask-spread and risk aversion of market participants. The welfare impacts for a broad range of supply, demand, grid and inefficiency parameters are analyzed numerically. For efficient spot and forward markets, the results of the literature of nodal pricing being the efficient benchmark are confirmed. With inefficient transmission forward markets, however, zonal pricing proves advantageous in situations with little congestion and low costs. The results imply that the trade-off between the pricing regimes should be considered carefully when defining the geographical scope of bidding zones.

Congestion Management System Process Report

Science.gov (United States)

1996-03-01

In January 1995, the Indianapolis Metropolitan Planning Organization with the help of an interagency Study Review Committee began the process of developing a Congestion Management System (CMS) Plan resulting in this report. This report documents the ...

End to end adaptive congestion control in TCP/IP networks

CERN Document Server

Houmkozlis, Christos N

2012-01-01

This book provides an adaptive control theory perspective on designing congestion controls for packet-switching networks. Relevant to a wide range of disciplines and industries, including the music industry, computers, image trading, and virtual groups, the text extensively discusses source oriented, or end to end, congestion control algorithms. The book empowers readers with clear understanding of the characteristics of packet-switching networks and their effects on system stability and performance. It provides schemes capable of controlling congestion and fairness and presents real-world app

Impact Analysis of Land Use on Traffic Congestion Using Real-Time Traffic and POI

Directory of Open Access Journals (Sweden)

Tianqi Zhang

2017-01-01

Full Text Available This paper proposed a new method to describe, compare, and classify the traffic congestion points in Beijing, China, by using the online map data and further revealed the relationship between traffic congestion and land use. The data of the point of interest (POI and the real-time traffic was extracted from an electronic map of the area in the fourth ring road of Beijing. The POIs were quantified based on the architectural area of the land use; the congestion points were identified based on real-time traffic. Then, the cluster analysis using the attributes of congestion time was conducted to identify the main traffic congestion areas. The result of a linear regression analysis between the congestion time and the land use showed that the influence of the high proportion of commercial land use on the traffic congestion was significant. Also, we considered five types of land use through performing a linear regression analysis between the congestion time and the ratio of four types of land use. The results showed that the reasonable ratio of land use types could efficiently reduce congestion time. This study makes contributions to the policy-making of urban land use.

Congestion control in wireless links based on selective delivery of erroneous packets

DEFF Research Database (Denmark)

Korhonen, Jari; Perkis, Andrew; Reiter, Ulrich

2011-01-01

Traditionally, congestion control in packet networks is performed by reducing the transmission rate when congestion is detected, in order to cut down the traffic that overwhelms the capacity of the network. However, if the bottleneck is a wireless link, congestion is often cumulated because...... the performance of the proposed mechanism against traditional congestion control with a simulation study. The results show that the proposed approach can improve the overall performance both by increasing the throughput over the wireless and improving the video quality in terms of peak signal-to-noise ratio (PSNR...

An efficient statistical-based approach for road traffic congestion monitoring

KAUST Repository

Abdelhafid, Zeroual

2017-12-14

In this paper, we propose an effective approach which has to detect traffic congestion. The detection strategy is based on the combinational use of piecewise switched linear traffic (PWSL) model with exponentially-weighted moving average (EWMA) chart. PWSL model describes traffic flow dynamics. Then, PWSL residuals are used as the input of EWMA chart to detect traffic congestions. The evaluation results of the developed approach using data from a portion of the I210-W highway in Califorina showed the efficiency of the PWSL-EWMA approach in in detecting traffic congestions.

An efficient statistical-based approach for road traffic congestion monitoring

KAUST Repository

Abdelhafid, Zeroual; Harrou, Fouzi; Sun, Ying

2017-01-01

In this paper, we propose an effective approach which has to detect traffic congestion. The detection strategy is based on the combinational use of piecewise switched linear traffic (PWSL) model with exponentially-weighted moving average (EWMA) chart. PWSL model describes traffic flow dynamics. Then, PWSL residuals are used as the input of EWMA chart to detect traffic congestions. The evaluation results of the developed approach using data from a portion of the I210-W highway in Califorina showed the efficiency of the PWSL-EWMA approach in in detecting traffic congestions.

Modeling of demand response in electricity markets : effects of price elasticity

International Nuclear Information System (INIS)

Banda, E.C.; Tuan, L.A.

2007-01-01

A design mechanism for the optimal participation of customer load in electricity markets was presented. In particular, this paper presented a modified market model for the optimal procurement of interruptible loads participating in day-ahead electricity markets. The proposed model considers the effect of price elasticity and demand-response functions. The objective was to determine the role that price elasticity plays in electricity markets. The simulation model can help the Independent System Operator (ISO) identify customers offering the lowest price of interruptible loads and load flow patterns that avoid problems associated with transmission congestion and transmission losses. Various issues associated with procurement of demand-response offerings such as advance notification, locational aspect of load, and power factor of the loads, were considered. It was shown that demand response can mitigate price volatility by allowing the ISO to maintain operating reserves during peak load periods. It was noted that the potential benefits of the demand response program would be reduced when price elasticity of demand is taken into account. This would most likely occur in actual developed open electricity markets, such as Nordpool. This study was based on the CIGRE 32-bus system, which represents the Swedish high voltage power system. It was modified for this study to include a broad range of customer characteristics. 18 refs., 2 tabs., 14 figs

Impact of multilateral congestion management on the reliability of power transactions

International Nuclear Information System (INIS)

Rodrigues, A.B.; Da Silva, M.G.

2003-01-01

The restructuring of the electricity industry has caused an increase in the number of transactions in the energy market. These transactions are defined by market forces without considering operational constraints of the transmission system. Consequently, there are transactions that cause congestion in the transmission network. This paper has as objective to assess the impact of multilateral congestion management on the reliability of power transactions. This assessment is based on reliability indices such as expected power curtailments, curtailment probability, expected cost of congestion management and probability distributions of the total power curtailment. Tests results with IEEE RTS-1996 demonstrate that the multilateral management results in smaller curtailments and congestion costs than traditional bilateral management. (author)

A Credit-Based Congestion-Aware Incentive Scheme for DTNs

Directory of Open Access Journals (Sweden)

Qingfeng Jiang

2016-12-01

Full Text Available In Delay-Tolerant Networks (DTNs, nodes may be selfish and reluctant to expend their precious resources on forwarding messages for others. Therefore, an incentive scheme is necessary to motivate selfish nodes to cooperatively forward messages. However, the current incentive schemes mainly focus on encouraging nodes to participate in message forwarding, without considering the node congestion problem. When many messages are forwarded to the nodes with high connection degree, these nodes will become congested and deliberately discard messages, which will seriously degrade the routing performance and reduce the benefits of other nodes. To address this problem, we propose a credit-based congestion-aware incentive scheme (CBCAIS for DTNs. In CBCAIS, a check and punishment mechanism is proposed to prevent forwarding nodes from deliberately discarding message. In addition, a message acceptance selection mechanism is proposed to allow the nodes to decide whether to accept other messages, according to self congestion degree. The experimental results show that CBCAIS can effectively stimulate selfish nodes to cooperatively forward messages, and achieve a higher message delivery ratio with lower overhead ratio, compared with other schemes.

Give or take? Rewards versus charges for a congested bottleneck

NARCIS (Netherlands)

Rouwendal, J.; Verhoef, E.T.; Knockaert, J.

2012-01-01

This paper analyzes the possibilities to relieve traffic congestion using subsidies instead of Pigouvian taxes, as well as revenue-neutral combinations of rewards and taxes ('feebates'). The model considers a Vickrey-ADL model of bottleneck congestion with endogenous scheduling. With inelastic

Relationship Between Carbon Dioxide Levels and Reported Congestion and Headaches on the International Space Station

Science.gov (United States)

Cole, Robert; Wear, Mary; Young, Millennia; Cobel, Christopher; Mason, Sara

2017-01-01

Congestion is commonly reported during spaceflight, and most crewmembers have reported using medications for congestion during International Space Station (ISS) missions. Although congestion has been attributed to fluid shifts during spaceflight, fluid status reaches equilibrium during the first week after launch while congestion continues to be reported throughout long duration missions. Congestion complaints have anecdotally been reported in relation to ISS CO2 levels; this evaluation was undertaken to determine whether or not an association exists. METHODS: Reported headaches, congestion symptoms, and CO2 levels were obtained for ISS expeditions 2-31, and time-weighted means and single-point maxima were determined for 24-hour (24hr) and 7-day (7d) periods prior to each weekly private medical conference. Multiple imputation addressed missing data, and logistic regression modeled the relationship between probability of reported event of congestion or headache and CO2 levels, adjusted for possible confounding covariates. The first seven days of spaceflight were not included to control for fluid shifts. Data were evaluated to determine the concentration of CO2 required to maintain the risk of congestion below 1% to allow for direct comparison with a previously published evaluation of CO2 concentrations and headache. RESULTS: This study confirmed a previously identified significant association between CO2 and headache and also found a significant association between CO2 and congestion. For each 1-mm Hg increase in CO2, the odds of a crew member reporting congestion doubled. The average 7-day CO2 would need to be maintained below 1.5 mmHg to keep the risk of congestion below 1%. The predicted probability curves of ISS headache and congestion curves appear parallel when plotted against ppCO2 levels with congestion occurring at approximately 1mmHg lower than a headache would be reported. DISCUSSION: While the cause of congestion is multifactorial, this study showed

The impact of anti-congestion policies on fuel consumption, carbon dioxide emissions and urban sprawl: Application of RELU-TRAN2, a CGE model

Science.gov (United States)

Hiramatsu, Tomoru

RELU-TRAN (Regional Economy and Land Use and Transportation) is a numerically solvable general equilibrium model (Anas and Liu, 2007), which treats in a unified manner the regional economy, urban land use and urban personal transportation sectors. In this dissertation, the model is extended by adding the consumer-workers' choice of private vehicle type according to the vehicle's fuel economy, by treating congestion on local roads as well as on major roads and by introducing car fuel consumption as a function of congested vehicle speed. By making the extensions, the model becomes more suitable to analyze the fuel consumption and CO2 emission consequences of urban development. The model is calibrated and simulated for the Chicago metropolitan area. By adjusting the model to the longer time span gradually, the shortand long-run price elasticities of fuel consumption are examined. As the time span becomes longer, fuel consumption becomes more elastic with respect to gasoline price, but when technological improvements in car fuel economy over comparable time spans are introduced exogenously, then the elasticity of fuel with respect to gasoline price becomes similar to that estimated in the econometric literature. Comparative statics exercises show that, if travel by auto becomes relatively more attractive in terms of travel time or travel cost than travel by public transit, then the Chicago MSA becomes more sprawled in total developed land area, whereas if public transit travel becomes relatively more attractive, then the Chicago MSA becomes more centralized. To mitigate fuel consumption and CO2 emissions, relative effectiveness of quasi-Pigouvian congestion tolls, a fuel tax on gasoline, a cordon toll around the downtown and a downtown parking fee are tested. All of these policies successfully reduce the aggregate fuel consumption and CO2. The urban growth boundary (UGB) is an alternative policy tested by the model. The UGB directly makes the Chicago MSA more

Nordic congestion's arrangement as a model for Europe? Physical constraints vs. economic incentives

International Nuclear Information System (INIS)

Glachant, J.-M.; Pignon, V.

2005-01-01

Congestion on power grids seems a physical reality, a 'hard' fact easy to check. Our paper models a different idea: congestion signal may be distorted by transmission system operators (TSOs). Indeed, congestion signals are not physical data but 'home made' conventions directly set by the TSOs in charge of the security of the system. These security norms are not stable and invariable because lines capacity limits are not constant. TSOs, therefore, define the congestion signal on a variable, complex and non-transparent constraint and may manipulate it for monetary purposes or for other personal agenda. In Nordic countries the coexistence of two congestion management methods in a 'Light Handed Regulation' framework makes this opportunistic behaviour even more likely. (author)

Public Capital, Congestion and Private Production in Australia

OpenAIRE

Lei Lei Song

2002-01-01

This paper is an empirical investigation into the impact of public capital on the private sector’s economic activity in Australia. In particular, it is assumed that the contribution of public capital to private factor productivity is subject to congestion. New data sets of capital stocks and private output are constructed for the Australian economy. By estimating flexible functional forms of private sector production functions with congestion in public capital services, the paper shows that p...

Estimation of pulmonary water distribution and pulmonary congestion by computed tomography

International Nuclear Information System (INIS)

Morooka, Nobuhiro; Watanabe, Shigeru; Masuda, Yoshiaki; Inagaki, Yoshiaki

1982-01-01

Computed tomography (CT) of the lung in normal subjects and patients with congestive heart failure was performed in the supine position with deep inspiration to obtain pulmonary CT values and images. The mean CT value in normal subjects was higher in the posterior than anterior lung field, presumably because blood vessels were more dilated in the former than the latter due to the effects of gravity. The mean pulmonary CT value in patients with congestive heart failure was significantly increased possibly due to an increase in blood flow per unit lung volume arising from either pulmonary congestion or pulmonary interstitial and alveolar edema. The mean pulmonary CT value increased parallel to the severity of pulmonary congestion, interstitial or alveolar edema and was well correlated with the pulmonary arterial wedge pressure, indicating that such a correlation was a valuable tool in assessing therapeutic effects. The results of the present study indicatethat pulmonary CT is useful for the noninvasive estimation of intrapulmonary water content and its distribution, thereby providing an effective diagnostic clue to various conditions in congestive heart failure. (author)

Large-scale transportation network congestion evolution prediction using deep learning theory.

Science.gov (United States)

Ma, Xiaolei; Yu, Haiyang; Wang, Yunpeng; Wang, Yinhai

2015-01-01

Understanding how congestion at one location can cause ripples throughout large-scale transportation network is vital for transportation researchers and practitioners to pinpoint traffic bottlenecks for congestion mitigation. Traditional studies rely on either mathematical equations or simulation techniques to model traffic congestion dynamics. However, most of the approaches have limitations, largely due to unrealistic assumptions and cumbersome parameter calibration process. With the development of Intelligent Transportation Systems (ITS) and Internet of Things (IoT), transportation data become more and more ubiquitous. This triggers a series of data-driven research to investigate transportation phenomena. Among them, deep learning theory is considered one of the most promising techniques to tackle tremendous high-dimensional data. This study attempts to extend deep learning theory into large-scale transportation network analysis. A deep Restricted Boltzmann Machine and Recurrent Neural Network architecture is utilized to model and predict traffic congestion evolution based on Global Positioning System (GPS) data from taxi. A numerical study in Ningbo, China is conducted to validate the effectiveness and efficiency of the proposed method. Results show that the prediction accuracy can achieve as high as 88% within less than 6 minutes when the model is implemented in a Graphic Processing Unit (GPU)-based parallel computing environment. The predicted congestion evolution patterns can be visualized temporally and spatially through a map-based platform to identify the vulnerable links for proactive congestion mitigation.

Management of congestive heart failure (CHF): a case report on ...

African Journals Online (AJOL)

A case report on the management of Congestive Heart Failure is presented with emphasis on the use of DIGOXIN. Keywords: Congestive heart failure, Failing heart syndrome, Digoxin, Digoxin Toxicity. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

Tracing based congestion management and impact of TCPS in competitive power market using MINLP

International Nuclear Information System (INIS)

Kumar, A.; Chanana, S.

2006-01-01

Efficient, fair and secure operation of the competitive power markets are key factors in managing the challenges associated with congestion management. For the system operator, the selection of generators to reschedule their output for effective management of congestion is an important task. This study used a real power flow tracing based approach for selecting the most appropriate generators to reschedule the real power output based on real power flow contribution on a congested line. These generators can be effectively used to reschedule their generation for managing congestion. Using a mixed integer non-linear programming approach for reducing the transmission congestion cost in the system, the impact of Thyristor Controlled Phase Shifter (TCPS) was also investigated and their optimal placement was obtained. The study was carried out on a 39-bus New England system for pool and mix of pool with bilateral and multilateral transactions and their impact on congestion cost. The paper presented the detailed mathematical formulation and modeling process used. It was concluded that for some transactions, the reduction in congestion cost is not very significant. Therefore, system operators should avoid such transactions during congestion to increase market efficiency. 26 refs., 1 tab., 8 figs

The Potential of Road Pricing Schemes for Reducing Carbon Emissions

Energy Technology Data Exchange (ETDEWEB)

Nocera, S.; Giaretta, F.; Cavallaro, F.

2016-07-01

Road pricing is a transport measure mainly conceived to fund road management, to regulate the demand for traffic and to reduce the number of private vehicles circulating in urban areas. It can also grant benefits in terms of environmental externalities including the reduction of CO2 emissions, which has recently become one of the most important elements defining the sustainability of a transport system. However, the carbon potential granted by road charging is rarely assessed, thus confirming a sort of secondary role attributed to CO2 in urban premises. This paper provides an accurate analysis of the relationship between the different forms of road pricing (including distance-based, congestion-based and pay-as-you-drive) and their effective role in terms of carbon reduction, which in some contexts is higher than 10%. Furthermore, practical suggestions to policy makers in terms of implementation of the measure are discussed, highlighting the precautions necessary to include a fair carbon evaluation into an overall effective analysis. (Author)

23 CFR 973.214 - Indian lands congestion management system (CMS).

Science.gov (United States)

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Indian lands congestion management system (CMS). 973.214... HIGHWAYS MANAGEMENT SYSTEMS PERTAINING TO THE BUREAU OF INDIAN AFFAIRS AND THE INDIAN RESERVATION ROADS PROGRAM Bureau of Indian Affairs Management Systems § 973.214 Indian lands congestion management system...

Analysis of the network capacities and possible congestion of the electricity transmission networks within the accession countries

International Nuclear Information System (INIS)

Kristiansen, Tarjei; Hewicker, Cristian

2005-01-01

cross-border network constraints. Besides the technical parameters to describe production and main network characteristics, the main remaining input factors are costs/fuel prices and demand.The outputs of the PROSYM tool are generation quantities, costs, short-run marginal prices and flows. To calibrate the model and to check its accuracy, we have first performed simulations for the year 2003 (the reference year) where information on actual market prices and (physical) cross-border flows is available. Thereafter, we have run additional simulations for the years 2010 and 2020 to analyse the future development of generation, export and import patterns, and to assess the influence of new interconnector projects. Due to uncertainty about future development, we have additionally tested the sensitivity of our base case to changes in e.g. the rate of growth in generation capacity and demand, the future generation structure, or the development of fuel prices. With a view to the economic import and export potential, our investigations confirm the assumption that network constraints represent a major barrier to the free exchange of electricity within the IEM. Considering the frequency and severity of congestion, our calculations show major network constraints at the following borders: 1) From Central Eastern Europe (Poland, Czech Republic, Slovakia) to Germany, Austria and Hungary; 2) From Austria and Slovenia to Italy; 3) From Bulgaria and Serbia and Montenegro (respectively Macedonia) to Greece. Our results show, not unexpectedly, considerable differences in the net benefits of individual transmission capacity increases, due to differences in market value and/or investment costs. (Author)

Large-scale transportation network congestion evolution prediction using deep learning theory.

Directory of Open Access Journals (Sweden)

Xiaolei Ma

Full Text Available Understanding how congestion at one location can cause ripples throughout large-scale transportation network is vital for transportation researchers and practitioners to pinpoint traffic bottlenecks for congestion mitigation. Traditional studies rely on either mathematical equations or simulation techniques to model traffic congestion dynamics. However, most of the approaches have limitations, largely due to unrealistic assumptions and cumbersome parameter calibration process. With the development of Intelligent Transportation Systems (ITS and Internet of Things (IoT, transportation data become more and more ubiquitous. This triggers a series of data-driven research to investigate transportation phenomena. Among them, deep learning theory is considered one of the most promising techniques to tackle tremendous high-dimensional data. This study attempts to extend deep learning theory into large-scale transportation network analysis. A deep Restricted Boltzmann Machine and Recurrent Neural Network architecture is utilized to model and predict traffic congestion evolution based on Global Positioning System (GPS data from taxi. A numerical study in Ningbo, China is conducted to validate the effectiveness and efficiency of the proposed method. Results show that the prediction accuracy can achieve as high as 88% within less than 6 minutes when the model is implemented in a Graphic Processing Unit (GPU-based parallel computing environment. The predicted congestion evolution patterns can be visualized temporally and spatially through a map-based platform to identify the vulnerable links for proactive congestion mitigation.

Research on Analysis Method of Traffic Congestion Mechanism Based on Improved Cell Transmission Model

Directory of Open Access Journals (Sweden)

Hongzhao Dong

2012-01-01

Full Text Available To analyze the spreading regularity of the initial traffic congestion, the improved cell transmission model (CTM is proposed to describe the evolution mechanism of traffic congestion in regional road grid. Ordinary cells and oriented cells are applied to render the crowd roads and their adjacent roads. Therefore the traffic flow could be simulated by these cells. Resorting to the proposed model, the duration of the initial traffic congestion could be predicted and the subsequent secondary congestion could be located. Accordingly, the spatial diffusion of traffic congestion could be estimated. At last, taking a road network region of Hangzhou city as an example, the simulation experiment is implemented to verify the proposed method by PARAMICS software. The result shows that the method could predict the duration of the initial congestion and estimate its spatial diffusion accurately.

Real-Time Congestion Management in Distribution Networks by Flexible Demand Swap

DEFF Research Database (Denmark)

Huang, Shaojun; Wu, Qiuwei

2017-01-01

In addition to the day-ahead congestion management in distribution networks, the real-time congestion management is very important because many unforeseen events can occur at the real operation time, e.g. loss of generation of distributed energy resources (DERs) or inaccurate forecast of energy...... pumps (HPs) for real time congestion management. The swap method can maintain the power balance of the system and avoid the imbalance cost of activating the flexibility service. An algorithm for forming swaps through optimal power flow (OPF) and mixed integer linear programming (MILP) is proposed...... consumption or production. Flexibility service from demand will be a good option to solve the real-time congestions if the cost of activating the flexibility service is fully addressed. This paper proposes a new method, namely “swap”, to employ the flexibility service from electric vehicles (EVs) and heat...

Congestive Heart Failure and Central Sleep Apnea.

Science.gov (United States)

Sands, Scott A; Owens, Robert L

2016-03-01

Congestive heart failure (CHF) is among the most common causes of admission to hospitals in the United States, especially in those over age 65. Few data exist regarding the prevalence CHF of Cheyne-Stokes respiration (CSR) owing to congestive heart failure in the intensive care unit (ICU). Nevertheless, CSR is expected to be highly prevalent among those with CHF. Treatment should focus on the underlying mechanisms by which CHF increases loop gain and promotes unstable breathing. Few data are available to determine prevalence of CSR in the ICU, or how CSR might affect clinical management and weaning from mechanical ventilation. Copyright © 2016 Elsevier Inc. All rights reserved.

Congestion management of distribution networks with day-ahead dynamic grid tariffs

DEFF Research Database (Denmark)

Huang, Shaojun; Wu, Qiuwei

vehicles (EV) and heat pumps (HP), will be largely deployed in electrical distribution networks. Congestion management will be important in the future active distribution networks. In the IDE4L project, work package 5 is dedicated to develop different kinds of congestion management methods. Demand response...... (DR) is one of the important methods. In this report, as one task of work package 5, the day-ahead dynamic tariff (DADT) method for congestion management in distribution networks is presented. The dynamic tariff (DT) can motivate the flexible demands (EV and HP) to shift their energy consumption...

Framework for Traffic Congestion Prediction

NARCIS (Netherlands)

Zaki, J.F.W.; Ali-Eldin, A.M.T.; Hussein, S.E.; Saraya, S.F.; Areed, F.F.

2016-01-01

Traffic Congestion is a complex dilemma facing most major cities. It has undergone a lot of research since the early 80s in an attempt to predict traffic in the short-term. Recently, Intelligent Transportation Systems (ITS) became an integral part of traffic research which helped in modeling and

Modeling truck traffic volume growth congestion.

Science.gov (United States)

2009-05-01

Modeling of the statewide transportation system is an important element in understanding issues and programming of funds to thwart potential congestion. As Alabama grows its manufacturing economy, the number of heavy vehicles traversing its highways ...

Hydropower planning coordinated with wind power in areas with congestion problems for trading on the spot and the regulating market

International Nuclear Information System (INIS)

Matevosyan, Julija; Olsson, Magnus; Soeder, Lennart

2009-01-01

In this paper a day-ahead planning algorithm for a multi-reservoir hydropower system coordinated with wind power is developed. Coordination applies to real situations, where wind power and hydropower are owned by different utilities, sharing the same transmission lines, though hydropower has priority for transmission capacity. Coordination is thus necessary to minimize wind energy curtailments during congestion situations. The planning algorithm accounts for the uncertainty of wind power forecasts and power market price uncertainty. Planning for the spot market and the regulating market is considered in the algorithm. The planning algorithm is applied to a case study and the results are summarized in the paper. (author)

Study and Analysis of Congestion Management in Hybrid Electric Market

Directory of Open Access Journals (Sweden)

Moayed Mohseni

2013-01-01

Full Text Available The congestion management system is a systematic approach, collaboratively developed and implemented throughout a metropolitan region that provides for the safe and effective management and operation of new and existing transportation facilities through the use of demand reduction and operational management strat­e­gies. In this paper we try to present some points which should be investigated in congestion management problems. We calculate different kinds of congestion problems which may be occurred in our network. Here, the hybrid model is used to solve problems in the electricity market to solve the congestion problem in the network and Benders techniques is used together with an optimal power flow (OPF. In fact, by using of Benders algorithm the problem is divided into two major and minor problems. Therefore, the major problem related to the economy sector and no network is included and the minor problem is to solve the network and examine the accuracy of the network. Benders algorithm has been tested on a standard network IEEE 24 bus and Matlab software is used to implement the algorithm.

A resilience-oriented approach for quantitatively assessing recurrent spatial-temporal congestion on urban roads.

Directory of Open Access Journals (Sweden)

Junqing Tang

Full Text Available Traffic congestion brings not only delay and inconvenience, but other associated national concerns, such as greenhouse gases, air pollutants, road safety issues and risks. Identification, measurement, tracking, and control of urban recurrent congestion are vital for building a livable and smart community. A considerable amount of works has made contributions to tackle the problem. Several methods, such as time-based approaches and level of service, can be effective for characterizing congestion on urban streets. However, studies with systemic perspectives have been minor in congestion quantification. Resilience, on the other hand, is an emerging concept that focuses on comprehensive systemic performance and characterizes the ability of a system to cope with disturbance and to recover its functionality. In this paper, we symbolized recurrent congestion as internal disturbance and proposed a modified metric inspired by the well-applied "R4" resilience-triangle framework. We constructed the metric with generic dimensions from both resilience engineering and transport science to quantify recurrent congestion based on spatial-temporal traffic patterns and made the comparison with other two approaches in freeway and signal-controlled arterial cases. Results showed that the metric can effectively capture congestion patterns in the study area and provides a quantitative benchmark for comparison. Also, it suggested not only a good comparative performance in measuring strength of proposed metric, but also its capability of considering the discharging process in congestion. The sensitivity tests showed that proposed metric possesses robustness against parameter perturbation in Robustness Range (RR, but the number of identified congestion patterns can be influenced by the existence of ϵ. In addition, the Elasticity Threshold (ET and the spatial dimension of cell-based platform differ the congestion results significantly on both the detected number and

Performance analysis of SS7 congestion controls under sustained overload

Science.gov (United States)

Manfield, David R.; Millsteed, Gregory K.; Zukerman, Moshe

1994-04-01

Congestion controls are a key factor in achieving the robust performance required of common channel signaling (CCS) networks in the face of partial network failures and extreme traffic loads, especially as networks become large and carry high traffic volume. The CCITT recommendations define a number of types of congestion control, and the parameters of the controls must be well set in order to ensure their efficacy under transient and sustained signalling network overload. The objective of this paper is to present a modeling approach to the determination of the network parameters that govern the performance of the SS7 congestion controls under sustained overload. Results of the investigation by simulation are presented and discussed.

Interjurisdictional trading rules and issues

International Nuclear Information System (INIS)

Keizer, C.

2001-01-01

Rules and issues regarding financial transmission rights were presented in this power point presentation which focused on access to the Ontario electricity grid. Power generators submit offers to the independent market operator (IMO) to participate in the IMO dispatch. This presentation covered uniform pricing issues in Ontario, the congestion pricing theory, congestion management, and how congestion pricing can apply to inter-regional trades. Inter-regional trading examples of buying and selling electricity in Ontario were also presented. IMOs have the power to auction transmission rights, which are the financial instrument that protects against exposure to changes in price differences. Initially, this would apply only to price differences between the uniform Ontario price and prices in each zone. The holders of financial transmission rights receive a portion of the congestion surplus collected through the IMO settlements as a result of congestion pricing on the entities. The problem is that this provides no incentive for transmitters. Another problem is that there are different trading regimes in Ontario, but it is preferable to have seamless trading across jurisdictions to promote inter-jurisdictional trading

Vehicle Routing with Traffic Congestion and Drivers' Driving and Working Rules

NARCIS (Netherlands)

Kok, A.L.; Hans, Elias W.; Schutten, Johannes M.J.; Zijm, Willem H.M.

2010-01-01

For the intensively studied vehicle routing problem (VRP), two real-life restrictions have received only minor attention in the VRP-literature: traffic congestion and driving hours regulations. Traffic congestion causes late arrivals at customers and long travel times resulting in large transport

A Cooperative Congestion Control Approach within VANETs: Formal Verification and Performance Evaluation

Directory of Open Access Journals (Sweden)

Bouassida MohamedSalah

2010-01-01

Full Text Available The main objective of congestion control is to best exploit the available network resources while preventing sustained overloads of network nodes and links. Appropriate congestion control mechanisms are essential to provide effcient operation of a network. Ensuring congestion control within vehicular ad hoc networks faces special challenges, due to the specificities of such environment (High mobility of nodes, high rate of topology changes, high variability in nodes density and neighborhood configuration, broadcast/geocast communication nature, etc.. In this context, we present in this paper a cooperative and fully distributed congestion control approach, based on dynamic scheduling and transmission of priority-based messages, to ensure reliable and safe communication architecture within VANET. Messages priorities are dynamically evaluated according to their types, the network context, and the neighboring nodes configuration. Considering the context of high reliability and real-time response required for intervehicular communications (including emergency breaking notification for example, we propose a complete validation method of our congestion control algorithms, taking into account reliability, temporal, and operational aspects.

Receiver-Assisted Congestion Control to Achieve High Throughput in Lossy Wireless Networks

Science.gov (United States)

Shi, Kai; Shu, Yantai; Yang, Oliver; Luo, Jiarong

2010-04-01

Many applications would require fast data transfer in high-speed wireless networks nowadays. However, due to its conservative congestion control algorithm, Transmission Control Protocol (TCP) cannot effectively utilize the network capacity in lossy wireless networks. In this paper, we propose a receiver-assisted congestion control mechanism (RACC) in which the sender performs loss-based control, while the receiver is performing delay-based control. The receiver measures the network bandwidth based on the packet interarrival interval and uses it to compute a congestion window size deemed appropriate for the sender. After receiving the advertised value feedback from the receiver, the sender then uses the additive increase and multiplicative decrease (AIMD) mechanism to compute the correct congestion window size to be used. By integrating the loss-based and the delay-based congestion controls, our mechanism can mitigate the effect of wireless losses, alleviate the timeout effect, and therefore make better use of network bandwidth. Simulation and experiment results in various scenarios show that our mechanism can outperform conventional TCP in high-speed and lossy wireless environments.

Expanding the Scope of Sustainability Planning: Lessons from Stockholm’s Congestion Charging Policy

Directory of Open Access Journals (Sweden)

Amy Rader Olsson

2017-10-01

Full Text Available In 2007, after years of unresolved debate, the Swedish parliament approved a congestion charge for Stockholm applied to cars crossing the city’s inner boundary. Since its introduction, congestion charging has led to an even more lasting reduction of car trips to the city center, in part because the policy generates revenues for financing new subway extensions and uses these same resources as the basis for negotiating new transit oriented housing in subway extension areas. As such, congestion charging is arguably as much a sustainable housing solution as it is a narrowly defined transit policy for reducing automobile congestion or pollution. This article investigates how and why Stockholm, despite considerable political conflict, technical complexity and negative public opinion, was able to turn a long-standing and controversial debate over moderating automobile traffic via tolls into widespread support for a national congestion tax, which itself laid the groundwork for a more expansive sustainability agenda. It further suggests that only when congestion charging was strategically reframed and widely recognized as addressing the concerns of multiple and competing constituencies, did efforts for its adoption translate into larger sustainability gains.

Transit Station Congestion Index Research Based on Pedestrian Simulation and Gray Clustering Evaluation

Directory of Open Access Journals (Sweden)

Shu-wei Wang

2013-01-01

Full Text Available A congestion phenomenon in a transit station could lead to low transfer efficiency as well as a hidden danger. Effective management of congestion phenomenon shall help to reduce the efficiency decline and danger risk. However, due to the difficulty in acquiring microcosmic pedestrian density, existing researches lack quantitative indicators to reflect congestion degree. This paper aims to solve this problem. Firstly, platform, stair, transfer tunnel, auto fare collection (AFC machine, and security check machine were chosen as key traffic facilities through large amounts of field investigation. Key facilities could be used to reflect the passenger density of a whole station. Secondly, the pedestrian density change law of each key traffic facility was analyzed using pedestrian simulation, and the load degree calculating method of each facility was defined, respectively, afterwards. Taking pedestrian density as basic data and gray clustering evaluation as algorithm, an index called Transit Station Congestion Index (TSCI was constructed to reflect the congestion degree of transit stations. Finally, an evaluation demonstration was carried out with five typical transit transfer stations in Beijing, and the evaluation results show that TSCI can objectively reflect the congestion degree of transit stations.

Three essays on pricing and risk management in electricity markets

Science.gov (United States)

Kotsan, Serhiy

2005-07-01

A set of three papers forms this dissertation. In the first paper I analyze an electricity market that does not clear. The system operator satisfies fixed demand at a fixed price, and attempts to minimize "cost" as indicated by independent generators' supply bids. No equilibrium exists in this situation, and the operator lacks information sufficient to minimize actual cost. As a remedy, we propose a simple efficient tax mechanism. With the tax, Nash equilibrium bids still diverge from marginal cost but nonetheless provide sufficient information to minimize actual cost, regardless of the tax rate or number of generators. The second paper examines a price mechanism with one price assigned for each level of bundled real and reactive power. Equilibrium allocation under this pricing approach raises system efficiency via better allocation of the reactive power reserves, neglected in the traditional pricing approach. Pricing reactive power should be considered in the bundle with real power since its cost is highly dependent on real power output. The efficiency of pricing approach is shown in the general case, and tested on the 30-bus IEEE network with piecewise linear cost functions of the generators. Finally the third paper addresses the problem of optimal investment in generation based on mean-variance portfolio analysis. It is assumed the investor can freely create a portfolio of shares in generation located on buses of the electrical network. Investors are risk averse, and seek to minimize the variance of the weighted average Locational Marginal Price (LMP) in their portfolio, and to maximize its expected value. I conduct simulations using a standard IEEE 68-bus network that resembles the New York - New England system and calculate LMPs in accordance with the PJM methodology for a fully optimal AC power flow solution. Results indicate that the network topology is a crucial determinant of the investment decision as line congestion makes it difficult to deliver power to

Bottleneck congestion and distribution of work start times: The economics of staggered work hours revisited

OpenAIRE

Takayama, Yuki

2014-01-01

Since the seminal work of Henderson (1981), a number of studies examined the effect of staggered work hours by analyzing models of work start time choice that consider the trade-off between negative congestion externalities and positive production externalities. However, these studies described traffic congestion using flow congestion models. This study develops a model of work start time choice with bottleneck congestion and discloses the intrinsic properties of the model. To this end, this ...

Beaconing Performance in IEEE 802.11p Vehicular Networks: the Effect of Radio Channel Congestion

OpenAIRE

Librino, Francesco; Renda, Maria Elena; Santi, Paolo

2013-01-01

In this paper, we study the performance of the beaconing mechanism underlying active safety vehicular applications in presence of different levels of channel congestion. The importance of this study lies in the fact that channel congestion is considered a major factor influencing communication performance in vehicular networks, and that ours is the first investigation of the effects of congestion based on extensive, real-world measurements. The results of our study reveal that congestion has ...

Congestion and residential moving behaviour

DEFF Research Database (Denmark)

Larsen, Morten Marott; Pilegaard, Ninette; Van Ommeren, Jos

2008-01-01

to congestion. We focus on the equilibrium in which some workers currently living in one region accept jobs in the other, with a fraction of them choosing to commute from their current residence to the new job in the other region and the remainder choosing to move to the region in which the new job is located...

A new casemix adjustment index for hospital mortality among patients with congestive heart failure.

Science.gov (United States)

Polanczyk, C A; Rohde, L E; Philbin, E A; Di Salvo, T G

1998-10-01

Comparative analysis of hospital outcomes requires reliable adjustment for casemix. Although congestive heart failure is one of the most common indications for hospitalization, congestive heart failure casemix adjustment has not been widely studied. The purposes of this study were (1) to describe and validate a new congestive heart failure-specific casemix adjustment index to predict in-hospital mortality and (2) to compare its performance to the Charlson comorbidity index. Data from all 4,608 admissions to the Massachusetts General Hospital from January 1990 to July 1996 with a principal ICD-9-CM discharge diagnosis of congestive heart failure were evaluated. Massachusetts General Hospital patients were randomly divided in a derivation and a validation set. By logistic regression, odds ratios for in-hospital death were computed and weights were assigned to construct a new predictive index in the derivation set. The performance of the index was tested in an internal Massachusetts General Hospital validation set and in a non-Massachusetts General Hospital external validation set incorporating data from all 1995 New York state hospital discharges with a primary discharge diagnosis of congestive heart failure. Overall in-hospital mortality was 6.4%. Based on the new index, patients were assigned to six categories with incrementally increasing hospital mortality rates ranging from 0.5% to 31%. By logistic regression, "c" statistics of the congestive heart failure-specific index (0.83 and 0.78, derivation and validation set) were significantly superior to the Charlson index (0.66). Similar incrementally increasing hospital mortality rates were observed in the New York database with the congestive heart failure-specific index ("c" statistics 0.75). In an administrative database, this congestive heart failure-specific index may be a more adequate casemix adjustment tool to predict hospital mortality in patients hospitalized for congestive heart failure.

Alleviate Cellular Congestion Through Opportunistic Trough Filling

Directory of Open Access Journals (Sweden)

Yichuan Wang

2014-04-01

Full Text Available The demand for cellular data service has been skyrocketing since the debut of data-intensive smart phones and touchpads. However, not all data are created equal. Many popular applications on mobile devices, such as email synchronization and social network updates, are delay tolerant. In addition, cellular load varies significantly in both large and small time scales. To alleviate network congestion and improve network performance, we present a set of opportunistic trough filling schemes that leverage the time-variation of network congestion and delay-tolerance of certain traffic in this paper. We consider average delay, deadline, and clearance time as the performance metrics. Simulation results show promising performance improvement over the standard schemes. The work shed lights on addressing the pressing issue of cellular overload.

Radiotherapy for hypersplenism from congestive splenomegaly

International Nuclear Information System (INIS)

Liu, Mu-Tai; Hsieh, Chang-Yo; Chang, Tung-Hao; Lin, Jao-Perng; Huang, Chia-Chun

2004-01-01

We evaluated the effects of splenic irradiation on the common hematological disorders of hypersplenism. From August 2002 to March 2003, five patients with hypersplenism due to congestive splenomegaly underwent splenic irradiation at the Department od Radiation Oncology, Changhua Chirstian Hospital, Taiwan. 3 were males and 2 were females aging from 38 to 66 years. All patients had history of liver cirrhosis. 4 patients underwent thee-dimensional conformal radiotherapy and received conventional radiotherapy with anterior-posterior parallel opposing fields. The followup-period ranged from 1 to 7 months. Thrombocytopenia and splenomegaly were found in all 5 patients by physical examination, hematological test, abdominal sonography and/or abdominal computed tomography. After radiotherapy, thrombocytopenia improved, but leukopenia and anemia did not. No complication due to radiotherapy was found during the follow-up period after splenic irradiation. 2 patients died of hepatocellular carcinoma with active bleeding. One patient died of renal failure due to end-stage renal disease. Based on our results, it seems that splenic irradiation might be effective in treating thrombocytopenia and splenomegaly. Splenic irradiatin seems to be effective for thrombocytopenia, splenomegaly and splenic pain associated with hypersplenism from congenstive splenomegaly. This approach is non-invasive and may be an alternative treatment for splenectomy and splenic embolization for patients with hypersplenism due to congestive splenomegaly. The shortcoming of this study are small sample size, short period of follow-up and lack of randomization. A randomized control trial with more cases and further follow-up of hematological tests and splenic size estimation are warranted to evaluate long term improvement of congestive splenomegaly with thrombocytopeniaafter splenic irradiation

COALA: A Protocol for the Avoidance and Alleviation of Congestion in Wireless Sensor Networks.

Science.gov (United States)

Kandris, Dionisis; Tselikis, George; Anastasiadis, Eleftherios; Panaousis, Emmanouil; Dagiuklas, Tasos

2017-10-31

The occurrence of congestion has an extremely deleterious impact on the performance of Wireless Sensor Networks (WSNs). This article presents a novel protocol, named COALA ( COngestion ALleviation and Avoidance ), which aims to act both proactively, in order to avoid the creation of congestion in WSNs, and reactively, so as to mitigate the diffusion of upcoming congestion through alternative path routing. Its operation is based on the utilization of an accumulative cost function, which considers both static and dynamic metrics in order to send data through the paths that are less probable to be congested. COALA is validated through simulation tests, which exhibit its ability to achieve remarkable reduction of loss ratios, transmission delays and energy dissipation. Moreover, the appropriate adjustment of the weighting of the accumulative cost function enables the algorithm to adapt to the performance criteria of individual case scenarios.

Traffic Congestion Detection System through Connected Vehicles and Big Data

OpenAIRE

Néstor Cárdenas-Benítez; Raúl Aquino-Santos; Pedro Magaña-Espinoza; José Aguilar-Velazco; Arthur Edwards-Block; Aldo Medina Cass

2016-01-01

This article discusses the simulation and evaluation of a traffic congestion detection system which combines inter-vehicular communications, fixed roadside infrastructure and infrastructure-to-infrastructure connectivity and big data. The system discussed in this article permits drivers to identify traffic congestion and change their routes accordingly, thus reducing the total emissions of CO2 and decreasing travel time. This system monitors, processes and stores large amounts of data, which ...

78 FR 67442 - Congestion Mitigation and Air Quality Improvement Program Interim Guidance

Science.gov (United States)

2013-11-12

...] Congestion Mitigation and Air Quality Improvement Program Interim Guidance AGENCY: Federal Highway... Comment. SUMMARY: The FHWA is issuing Interim Guidance on the Congestion Mitigation and Air Quality.../environment/air_quality/cmaq/policy_and_guidance/2008_guidance/ guidance/. DATES: This Interim Guidance is...

Grid Mapping for Spatial Pattern Analyses of Recurrent Urban Traffic Congestion Based on Taxi GPS Sensing Data

Directory of Open Access Journals (Sweden)

Yang Liu

2017-03-01

Full Text Available Traffic congestion is one of the most serious problems that impact urban transportation efficiency, especially in big cities. Identifying traffic congestion locations and occurring patterns is a prerequisite for urban transportation managers in order to take proper countermeasures for mitigating traffic congestion. In this study, the historical GPS sensing data of about 12,000 taxi floating cars in Beijing were used for pattern analyses of recurrent traffic congestion based on the grid mapping method. Through the use of ArcGIS software, 2D and 3D maps of the road network congestion were generated for traffic congestion pattern visualization. The study results showed that three types of traffic congestion patterns were identified, namely: point type, stemming from insufficient capacities at the nodes of the road network; line type, caused by high traffic demand or bottleneck issues in the road segments; and region type, resulting from multiple high-demand expressways merging and connecting to each other. The study illustrated that the proposed method would be effective for discovering traffic congestion locations and patterns and helpful for decision makers to take corresponding traffic engineering countermeasures in order to relieve the urban traffic congestion issues.

Distributed Optimization based Dynamic Tariff for Congestion Management in Distribution Networks

DEFF Research Database (Denmark)

Huang, Shaojun; Wu, Qiuwei; Zhao, Haoran

2017-01-01

This paper proposes a distributed optimization based dynamic tariff (DDT) method for congestion management in distribution networks with high penetration of electric vehicles (EVs) and heat pumps (HPs). The DDT method employs a decomposition based optimization method to have aggregators explicitly...... is able to minimize the overall energy consumption cost and line loss cost, which is different from previous decomposition-based methods such as multiagent system methods. In addition, a reconditioning method and an integral controller are introduced to improve convergence of the distributed optimization...... where challenges arise due to multiple congestion points, multiple types of flexible demands and network constraints. The case studies demonstrate the efficacy of the DDT method for congestion management in distribution networks....

Increased walking variability in elderly persons with congestive heart failure

Science.gov (United States)

Hausdorff, J. M.; Forman, D. E.; Ladin, Z.; Goldberger, A. L.; Rigney, D. R.; Wei, J. Y.

1994-01-01

OBJECTIVES: To determine the effects of congestive heart failure on a person's ability to walk at a steady pace while ambulating at a self-determined rate. SETTING: Beth Israel Hospital, Boston, a primary and tertiary teaching hospital, and a social activity center for elderly adults living in the community. PARTICIPANTS: Eleven elderly subjects (aged 70-93 years) with well compensated congestive heart failure (NY Heart Association class I or II), seven elderly subjects (aged 70-79 years) without congestive heart failure, and 10 healthy young adult subjects (aged 20-30 years). MEASUREMENTS: Subjects walked for 8 minutes on level ground at their own selected walking rate. Footswitches were used to measure the time between steps. Step rate (steps/minute) and step rate variability were calculated for the entire walking period, for 30 seconds during the first minute of the walk, for 30 seconds during the last minute of the walk, and for the 30-second period when each subject's step rate variability was minimal. Group means and 5% and 95% confidence intervals were computed. MAIN RESULTS: All measures of walking variability were significantly increased in the elderly subjects with congestive heart failure, intermediate in the elderly controls, and lowest in the young subjects. There was no overlap between the three groups using the minimal 30-second variability (elderly CHF vs elderly controls: P young: P < 0.001), and no overlap between elderly subjects with and without congestive heart failure when using the overall variability. For all four measures, there was no overlap in any of the confidence intervals, and all group means were significantly different (P < 0.05).

PRICE AND PRICING STRATEGIES

OpenAIRE

SUCIU Titus

2013-01-01

In individual companies, price is one significant factor in achieving marketing success. In many purchase situations, price can be of great importance to customers. Marketers must establish pricing strategies that are compatible with the rest of the marketing mix. Management should decide whether to charge the same price to all similar buyers of identical quantities of a product (a one-price strategy) or to set different prices (a flexible price strategy). Many organizations, especially retai...

HOW TRAVEL DEMAND AFFECTS DETECTION OF NON-RECURRENT TRAFFIC CONGESTION ON URBAN ROAD NETWORKS

Directory of Open Access Journals (Sweden)

B. Anbaroglu

2016-06-01

Full Text Available Occurrence of non-recurrent traffic congestion hinders the economic activity of a city, as travellers could miss appointments or be late for work or important meetings. Similarly, for shippers, unexpected delays may disrupt just-in-time delivery and manufacturing processes, which could lose them payment. Consequently, research on non-recurrent congestion detection on urban road networks has recently gained attention. By analysing large amounts of traffic data collected on a daily basis, traffic operation centres can improve their methods to detect non-recurrent congestion rapidly and then revise their existing plans to mitigate its effects. Space-time clusters of high link journey time estimates correspond to non-recurrent congestion events. Existing research, however, has not considered the effect of travel demand on the effectiveness of non-recurrent congestion detection methods. Therefore, this paper investigates how travel demand affects detection of non-recurrent traffic congestion detection on urban road networks. Travel demand has been classified into three categories as low, normal and high. The experiments are carried out on London’s urban road network, and the results demonstrate the necessity to adjust the relative importance of the component evaluation criteria depending on the travel demand level.

COALA: A Protocol for the Avoidance and Alleviation of Congestion in Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Dionisis Kandris

2017-10-01

Full Text Available The occurrence of congestion has an extremely deleterious impact on the performance of Wireless Sensor Networks (WSNs. This article presents a novel protocol, named COALA (COngestion ALleviation and Avoidance, which aims to act both proactively, in order to avoid the creation of congestion in WSNs, and reactively, so as to mitigate the diffusion of upcoming congestion through alternative path routing. Its operation is based on the utilization of an accumulative cost function, which considers both static and dynamic metrics in order to send data through the paths that are less probable to be congested. COALA is validated through simulation tests, which exhibit its ability to achieve remarkable reduction of loss ratios, transmission delays and energy dissipation. Moreover, the appropriate adjustment of the weighting of the accumulative cost function enables the algorithm to adapt to the performance criteria of individual case scenarios.

Essays on pricing electricity and electricity derivatives in deregulated markets

Science.gov (United States)

Popova, Julia

2008-10-01

This dissertation is composed of four essays on the behavior of wholesale electricity prices and their derivatives. The first essay provides an empirical model that takes into account the spatial features of a transmission network on the electricity market. The spatial structure of the transmission grid plays a key role in determining electricity prices, but it has not been incorporated into previous empirical models. The econometric model in this essay incorporates a simple representation of the transmission system into a spatial panel data model of electricity prices, and also accounts for the effect of dynamic transmission system constraints on electricity market integration. Empirical results using PJM data confirm the existence of spatial patterns in electricity prices and show that spatial correlation diminishes as transmission lines become more congested. The second essay develops and empirically tests a model of the influence of natural gas storage inventories on the electricity forward premium. I link a model of the effect of gas storage constraints on the higher moments of the distribution of electricity prices to a model of the effect of those moments on the forward premium. Empirical results using PJM data support the model's predictions that gas storage inventories sharply reduce the electricity forward premium when demand for electricity is high and space-heating demand for gas is low. The third essay examines the efficiency of PJM electricity markets. A market is efficient if prices reflect all relevant information, so that prices follow a random walk. The hypothesis of random walk is examined using empirical tests, including the Portmanteau, Augmented Dickey-Fuller, KPSS, and multiple variance ratio tests. The results are mixed though evidence of some level of market efficiency is found. The last essay investigates the possibility that previous researchers have drawn spurious conclusions based on classical unit root tests incorrectly applied to

Congestion control and routing over satellite networks

Science.gov (United States)

Cao, Jinhua

Satellite networks and transmissions find their application in fields of computer communications, telephone communications, television broadcasting, transportation, space situational awareness systems and so on. This thesis mainly focuses on two networking issues affecting satellite networking: network congestion control and network routing optimization. Congestion, which leads to long queueing delays, packet losses or both, is a networking problem that has drawn the attention of many researchers. The goal of congestion control mechanisms is to ensure high bandwidth utilization while avoiding network congestion by regulating the rate at which traffic sources inject packets into a network. In this thesis, we propose a stable congestion controller using data-driven, safe switching control theory to improve the dynamic performance of satellite Transmission Control Protocol/Active Queue Management (TCP/AQM) networks. First, the stable region of the Proportional-Integral (PI) parameters for a nominal model is explored. Then, a PI controller, whose parameters are adaptively tuned by switching among members of a given candidate set, using observed plant data, is presented and compared with some classical AQM policy examples, such as Random Early Detection (RED) and fixed PI control. A new cost detectable switching law with an interval cost function switching algorithm, which improves the performance and also saves the computational cost, is developed and compared with a law commonly used in the switching control literature. Finite-gain stability of the system is proved. A fuzzy logic PI controller is incorporated as a special candidate to achieve good performance at all nominal points with the available set of candidate controllers. Simulations are presented to validate the theory. An effocient routing algorithm plays a key role in optimizing network resources. In this thesis, we briefly analyze Low Earth Orbit (LEO) satellite networks, review the Cross Entropy (CE

Vehicle routing under time-dependent travel times: the impact of congestion avoidance

NARCIS (Netherlands)

Kok, A.L.; Hans, Elias W.; Schutten, Johannes M.J.

2009-01-01

Daily traffic congestions form major problems for businesses such as logistical service providers and distribution firms. They cause late arrivals at customers and additional hiring costs for the truck drivers. The additional costs of traffic congestions can be reduced by taking into account and

Effective use of congestion in complex networks

Science.gov (United States)

Echagüe, Juan; Cholvi, Vicent; Kowalski, Dariusz R.

2018-03-01

In this paper, we introduce a congestion-aware routing protocol that selects the paths according to the congestion of nodes in the network. The aim is twofold: on one hand, and in order to prevent the networks from collapsing, it provides a good tolerance to nodes' overloads; on the other hand, and in order to guarantee efficient communication, it also incentivize the routes to follow short paths. We analyze the performance of our proposed routing strategy by means of a series of experiments carried out by using simulations. We show that it provides a tolerance to collapse close to the optimal value. Furthermore, the average length of the paths behaves optimally up to the certain value of packet generation rate ρ and it grows in a linear fashion with the increase of ρ.

Can complexity decrease in congestive heart failure?

Science.gov (United States)

Mukherjee, Sayan; Palit, Sanjay Kumar; Banerjee, Santo; Ariffin, M. R. K.; Rondoni, Lamberto; Bhattacharya, D. K.

2015-12-01

The complexity of a signal can be measured by the Recurrence period density entropy (RPDE) from the reconstructed phase space. We have chosen a window based RPDE method for the classification of signals, as RPDE is an average entropic measure of the whole phase space. We have observed the changes in the complexity in cardiac signals of normal healthy person (NHP) and congestive heart failure patients (CHFP). The results show that the cardiac dynamics of a healthy subject is more complex and random compare to the same for a heart failure patient, whose dynamics is more deterministic. We have constructed a general threshold to distinguish the border line between a healthy and a congestive heart failure dynamics. The results may be useful for wide range for physiological and biomedical analysis.

How Smog Awareness Influences Public Acceptance of Congestion Charge Policies

OpenAIRE

Lingyi Zhou; Yixin Dai

2017-01-01

Although various studies have investigated public acceptance of congestion charge policies, most of them have focused on behavioral and policy-related factors, and did not consider the moderating influence that individual concern about smog and perceived smog risk may have on public acceptance. This paper takes the congestion charge policy in China, targeted at smog and traffic control, and checks how smog awareness—including smog concerns and perceived smog risks, besides behavioral and poli...

Novel Congestion-Free Alternate Routing Path Scheme using Stackelberg Game Theory Model in Wireless Networks

Directory of Open Access Journals (Sweden)

P. Chitra

2017-04-01

Full Text Available Recently, wireless network technologies were designed for most of the applications. Congestion raised in the wireless network degrades the performance and reduces the throughput. Congestion-free network is quit essen- tial in the transport layer to prevent performance degradation in a wireless network. Game theory is a branch of applied mathematics and applied sciences that used in wireless network, political science, biology, computer science, philosophy and economics. e great challenges of wireless network are their congestion by various factors. E ective congestion-free alternate path routing is pretty essential to increase network performance. Stackelberg game theory model is currently employed as an e ective tool to design and formulate conges- tion issues in wireless networks. is work uses a Stackelberg game to design alternate path model to avoid congestion. In this game, leaders and followers are selected to select an alternate routing path. e correlated equilibrium is used in Stackelberg game for making better decision between non-cooperation and cooperation. Congestion was continuously monitored to increase the throughput in the network. Simulation results show that the proposed scheme could extensively improve the network performance by reducing congestion with the help of Stackelberg game and thereby enhance throughput.

Traffic Congestion Evaluation and Signal Control Optimization Based on Wireless Sensor Networks: Model and Algorithms

Directory of Open Access Journals (Sweden)

Wei Zhang

2012-01-01

Full Text Available This paper presents the model and algorithms for traffic flow data monitoring and optimal traffic light control based on wireless sensor networks. Given the scenario that sensor nodes are sparsely deployed along the segments between signalized intersections, an analytical model is built using continuum traffic equation and develops the method to estimate traffic parameter with the scattered sensor data. Based on the traffic data and principle of traffic congestion formation, we introduce the congestion factor which can be used to evaluate the real-time traffic congestion status along the segment and to predict the subcritical state of traffic jams. The result is expected to support the timing phase optimization of traffic light control for the purpose of avoiding traffic congestion before its formation. We simulate the traffic monitoring based on the Mobile Century dataset and analyze the performance of traffic light control on VISSIM platform when congestion factor is introduced into the signal timing optimization model. The simulation result shows that this method can improve the spatial-temporal resolution of traffic data monitoring and evaluate traffic congestion status with high precision. It is helpful to remarkably alleviate urban traffic congestion and decrease the average traffic delays and maximum queue length.

Influence of Parking Price on Parking Garage Users’ Behaviour

Directory of Open Access Journals (Sweden)

Jelena Simićević

2012-09-01

Full Text Available Parking charge is a powerful tool for solving parking and traffic congestion problems. In order to achieve the expected effects without any adverse impact it is necessary to understand well the users’ responses to this policy. This paper, based on a sample of interviewed parking garage users, has developed binary logit model for identification and quantification of characteristics of users and trips, on which the acceptance of parking price is dependent. In addition, multinomial logit model has been made in order to predict what the users will opt for when faced with an increase in parking price. For the first time the parameter “shorten duration” has been introduced which has shown to be the most significant in making behaviour-related decisions. The results show that the users with the purpose work are the most sensitive to an increase in parking charge, what can be deemed positive for policy makers. However, great sensitivity of the users with the purpose shopping should cause their concern. The results of the multinomial model show that they would not discontinue coming into the area after all.

Índice de congestão portal e a ocorrência de trombose portal pós-dape Portal congestion and thrombosis after EDS

Directory of Open Access Journals (Sweden)

Fabio Gonçalves Ferreira

2005-08-01

Full Text Available OBJETIVO: Comparar os dados obtidos pela ultra-sonografia com doppler no pré-operatório de esquistossomóticos submetidos à desconexão ázigo-portal com esplenectomia (DAPE, calculando o índice de congestão portal, e sua correlação com a trombose portal no pós-operatório. MÉTODOS: Foram estudados 65 pacientes submetidos à DAPE por hipertensão portal esquistossomótica com antecedente de hemorragia digestiva, divididos em dois grupos: Grupo A (28 pacientes que não desenvolveram trombose portal pós-operatória e Grupo B (37 pacientes com trombose portal no pós-operatório. Analisaram-se através de ultra-sonografia com doppler no pré-operatório os seguintes parâmetros da veia porta: diâmetro, área, velocidade média de fluxo do sangue, fluxo de sangue, e estabeleceu-se o índice de congestão portal. RESULTADOS: O diâmetro, área e o fluxo da veia porta foram maiores no grupo B (média de 1,52 cm; 1,77 cm² e 2533,12 ml/min em relação ao grupo A (média de 1,33 cm; 1,44 cm² e 1609,03 ml/min com p = 0,03; 0,03 e 0,04 respectivamente. O índice de congestão portal não foi estatisticamente significativo na comparação dos dois grupos (p = 0,07. CONCLUSÃO: O índice de congestão portal obtido no pré-operatório através da ultra-sonografia com doppler não se mostrou preditivo de trombose portal no pós-operatório dos doentes estudados.BACKGROUND: The study compared the preoperative portal vein congestion index estimated by Doppler ultrasound and the postoperative portal vein thrombosis of patients submitted to esophagogastric devascularization and splenectomy (EDS. METHODS: 65 patients with portal hypertension due to schistosomiasis and previous gastrointestinal bleeding submitted to EDS were divided into two groups: GROUP A (28 patients without postoperative portal vein thrombosis and GROUP B (37 patients with postoperative portal vein thrombosis. The following parameters of preoperative Doppler ultrasound of the

Prices and Price Setting

NARCIS (Netherlands)

R.P. Faber (Riemer)

2010-01-01

textabstractThis thesis studies price data and tries to unravel the underlying economic processes of why firms have chosen these prices. It focuses on three aspects of price setting. First, it studies whether the existence of a suggested price has a coordinating effect on the prices of firms.

Mean Field Type Control with Congestion

Energy Technology Data Exchange (ETDEWEB)

Achdou, Yves, E-mail: achdou@ljll.univ-paris-diderot.fr; Laurière, Mathieu [Univ. Paris Diderot, Sorbonne Paris Cité, Laboratoire Jacques-Louis Lions, UMR 7598, UPMC, CNRS (France)

2016-06-15

We analyze some systems of partial differential equations arising in the theory of mean field type control with congestion effects. We look for weak solutions. Our main result is the existence and uniqueness of suitably defined weak solutions, which are characterized as the optima of two optimal control problems in duality.

The effects of price competition and reduced subsidies for uncompensated care on hospital mortality.

Science.gov (United States)

Volpp, Kevin G M; Ketcham, Jonathan D; Epstein, Andrew J; Williams, Sankey V

2005-08-01

To determine whether hospital mortality rates changed in New Jersey after implementation of a law that changed hospital payment from a regulated system based on hospital cost to price competition with reduced subsidies for uncompensated care and whether changes in mortality rates were affected by hospital market conditions. State discharge data for New Jersey and New York from 1990 to 1996. Study Design. We used an interrupted time series design to compare risk-adjusted in-hospital mortality rates between states over time. We compared the effect sizes in markets with different levels of health maintenance organization penetration and hospital market concentration and tested the sensitivity of our results to different approaches to defining hospital markets. The study sample included all patients under age 65 admitted to New Jersey or New York hospitals with stroke, hip fracture, pneumonia, pulmonary embolism, congestive heart failure, hip fracture, or acute myocardial infarction (AMI). Mortality among patients in New Jersey improved less than in New York by 0.4 percentage points among the insured (p=.07) and 0.5 percentage points among the uninsured (p=.37). There was a relative increase in mortality for patients with AMI, congestive heart failure, and stroke, especially for uninsured patients with these conditions, but not for patients with the other four conditions we studied. Less competitive hospital markets were significantly associated with a relative decrease in mortality among insured patients. Market-based reforms may adversely affect mortality for some conditions but it appears the effects are not universal. Insured patients in less competitive markets fared better in the transition to price competition.

TCP Congestion Control for the Networks with Markovian Jump Parameters

Directory of Open Access Journals (Sweden)

MOMENI, H. R.

2011-05-01

Full Text Available This paper is concerned with the problem of TCP congestion control for the class of communication networks with random parameters. The linear dynamic model of TCP New Reno in congestion avoidance mode is considered which contains round trip delays in both state and input. The randomness of link capacity, round trip time delay and the number of TCP sessions is modeled with a continuous-time finite state Markov process. An Active Queue Management (AQM technique is then used to adjust the queue level of the congested link to a predefined value. For this purpose, a dynamic output feedback controller with mode dependent parameters is synthesized to stochastically stabilize the TCP/AQM dynamics. The procedure of the control synthesis is implemented by solving a linear matrix inequality (LMI. The results are tested within a simulation example and the effectiveness of the proposed design method is verified.

Chance Constrained Input Relaxation to Congestion in Stochastic DEA. An Application to Iranian Hospitals.

Science.gov (United States)

Kheirollahi, Hooshang; Matin, Behzad Karami; Mahboubi, Mohammad; Alavijeh, Mehdi Mirzaei

2015-01-01

This article developed an approached model of congestion, based on relaxed combination of inputs, in stochastic data envelopment analysis (SDEA) with chance constrained programming approaches. Classic data envelopment analysis models with deterministic data have been used by many authors to identify congestion and estimate its levels; however, data envelopment analysis with stochastic data were rarely used to identify congestion. This article used chance constrained programming approaches to replace stochastic models with "deterministic equivalents". This substitution leads us to non-linear problems that should be solved. Finally, the proposed method based on relaxed combination of inputs was used to identify congestion input in six Iranian hospital with one input and two outputs in the period of 2009 to 2012.

A Bioinspired Adaptive Congestion-Avoidance Routing for Mobile Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Huang Qiong

2014-01-01

Full Text Available Traditional mobile Ad Hoc network routing protocols are mainly based on the Shortest Path, which possibly results in many congestion nodes that incur routing instability and rerouting. To mitigate the side-efforts, this paper proposed a new bioinspired adaptive routing protocol (ATAR based on a mathematics biology model ARAS. This paper improved the ARAS by reducing the randomness and by introducing a new routing-decision metric “the next-hop fitness” which was denoted as the congestion level of node and the length of routing path. In the route maintenance, the nodes decide to forward the data to next node according to a threshold value of the fitness. In the recovery phase, the node will adopt random manner to select the neighbor as the next hop by calculation of the improved ARAS. With this route mechanism, the ATAR could adaptively circumvent the congestion nodes and the rerouting action is taken in advance. Theoretical analysis and numerical simulation results show that the ATAR protocol outperforms AODV and MARAS in terms of delivery ratio, ETE delay, and the complexity. In particular, ATAR can efficiently mitigate the congestion.

Application of economic models to estimate the acceptability of a vehicle congestion charge

Directory of Open Access Journals (Sweden)

José Carlos Jiménez Serpa

2017-07-01

Full Text Available Introduction: Through the study of the problems generated by vehicular traffic congestion during periods of maximum demand, the negative externality of congestion would be assessed using Multinomial Logit, Mixed and econometric models, and willingness to pay through a Pigouvian rate. Objective: In this article, we propose to implement a congestion charge to manage vehicular demand, through the application of declared preference gages and econometric models. Methodology: The study consists of the execution of 6 steps or stages: Background of the problem, Context of study, Methodological Foundations, Specification and estimation of the model, Estimation of the function average cost user and social marginal cost, Results obtained Discussion and report. Results: Analyzing the models obtained from the 2053 observations made through the declared preference surveys, it was observed that in order to discourage the use of the private car, a rate of COP 7000 per vehicle entering the congestion area or area should be charged, which would decrease the Use of Auto Particular in 68.7%, referring to this behavior we can say that the government policies that set the collection of the congestion charge is a policy that does not fit the perception of the users. Conclusions: This research identified the rate that reflects as closely as possible the marginal social cost and the generalized costs of each trip in terms of the impacts on the others. Now if we consider the marginal cost due to congestion, we have that the current demand is excessive, the users enjoy the benefit at a cost of $ 3,100COP, but impose to others a quota of $22,152COP. Finally, it is necessary to strengthen the legal basis with the regulation and creation of a National Vehicle Electronic Identification System, which will allow, in principle, charges for congestion.

Frame Transmission Efficiency-Based Cross-Layer Congestion Notification Scheme in Wireless Ad Hoc Networks.

Science.gov (United States)

He, Huaguang; Li, Taoshen; Feng, Luting; Ye, Jin

2017-07-15

Different from the traditional wired network, the fundamental cause of transmission congestion in wireless ad hoc networks is medium contention. How to utilize the congestion state from the MAC (Media Access Control) layer to adjust the transmission rate is core work for transport protocol design. However, recent works have shown that the existing cross-layer congestion detection solutions are too complex to be deployed or not able to characterize the congestion accurately. We first propose a new congestion metric called frame transmission efficiency (i.e., the ratio of successful transmission delay to the frame service delay), which describes the medium contention in a fast and accurate manner. We further present the design and implementation of RECN (ECN and the ratio of successful transmission delay to the frame service delay in the MAC layer, namely, the frame transmission efficiency), a general supporting scheme that adjusts the transport sending rate through a standard ECN (Explicit Congestion Notification) signaling method. Our method can be deployed on commodity switches with small firmware updates, while making no modification on end hosts. We integrate RECN transparently (i.e., without modification) with TCP on NS2 simulation. The experimental results show that RECN remarkably improves network goodput across multiple concurrent TCP flows.

On the Existence of Solutions for Stationary Mean-Field Games with Congestion

KAUST Repository

Evangelista, David; Gomes, Diogo A.

2017-01-01

Mean-field games (MFGs) are models of large populations of rational agents who seek to optimize an objective function that takes into account their location and the distribution of the remaining agents. Here, we consider stationary MFGs with congestion and prove the existence of stationary solutions. Because moving in congested areas is difficult, agents prefer to move in non-congested areas. As a consequence, the model becomes singular near the zero density. The existence of stationary solutions was previously obtained for MFGs with quadratic Hamiltonians thanks to a very particular identity. Here, we develop robust estimates that give the existence of a solution for general subquadratic Hamiltonians.

On the Existence of Solutions for Stationary Mean-Field Games with Congestion

KAUST Repository

Evangelista, David

2017-09-11

Mean-field games (MFGs) are models of large populations of rational agents who seek to optimize an objective function that takes into account their location and the distribution of the remaining agents. Here, we consider stationary MFGs with congestion and prove the existence of stationary solutions. Because moving in congested areas is difficult, agents prefer to move in non-congested areas. As a consequence, the model becomes singular near the zero density. The existence of stationary solutions was previously obtained for MFGs with quadratic Hamiltonians thanks to a very particular identity. Here, we develop robust estimates that give the existence of a solution for general subquadratic Hamiltonians.

Green Eco-Driving Effects in Non-Congested Cities

Directory of Open Access Journals (Sweden)

Juan Francisco Coloma

2017-12-01

Full Text Available Despite technological advances in engines and fuels, the transportation sector is still one of the largest emitters of greenhouse gas (GHG. Driving patterns, including eco-driving techniques, are a complementary measure for saving GHG emissions. Most eco-driving studies so far have been conducted in large cities suffering chronic congestion problems. The aim of this research is therefore to analyse the potential of driver behaviour for reducing emissions in a small non-congested city. Driver performance parameters such as travel speeds, number of stops, revolutions per minute, and maximum acceleration-deceleration are also studied. The methodology is designed to measure the effect of both eco-driving and eco-routing under real traffic conditions. A campaign was carried out in the city of Caceres (Spain to collect data on various types of roads under different traffic conditions. This research concludes that eco-driving leads to CO2 savings on all routes and road types of 17% in gasoline engines and 21% in diesel, although travel times are increased by 7.5% on average. The shortest route is also the most ecological, regardless of the traffic volume and characteristics, implying that consumption in non-congested cities depends mainly on distance travelled rather than driving patterns in terms of number of stops, speed and acceleration.

Congestion-Aware Warehouse Flow Analysis and Optimization

KAUST Repository

AlHalawani, Sawsan

2015-12-18

Generating realistic configurations of urban models is a vital part of the modeling process, especially if these models are used for evaluation and analysis. In this work, we address the problem of assigning objects to their storage locations inside a warehouse which has a great impact on the quality of operations within a warehouse. Existing storage policies aim to improve the efficiency by minimizing travel time or by classifying the items based on some features. We go beyond existing methods as we analyze warehouse layout network in an attempt to understand the factors that affect traffic within the warehouse. We use simulated annealing based sampling to assign items to their storage locations while reducing traffic congestion and enhancing the speed of order picking processes. The proposed method enables a range of applications including efficient storage assignment, warehouse reliability evaluation and traffic congestion estimation.

Congestion-Aware Warehouse Flow Analysis and Optimization

KAUST Repository

AlHalawani, Sawsan; Mitra, Niloy J.

2015-01-01

Generating realistic configurations of urban models is a vital part of the modeling process, especially if these models are used for evaluation and analysis. In this work, we address the problem of assigning objects to their storage locations inside a warehouse which has a great impact on the quality of operations within a warehouse. Existing storage policies aim to improve the efficiency by minimizing travel time or by classifying the items based on some features. We go beyond existing methods as we analyze warehouse layout network in an attempt to understand the factors that affect traffic within the warehouse. We use simulated annealing based sampling to assign items to their storage locations while reducing traffic congestion and enhancing the speed of order picking processes. The proposed method enables a range of applications including efficient storage assignment, warehouse reliability evaluation and traffic congestion estimation.

Traffic congestion and blood pressure elevation: A comparative cross-sectional study in Lebanon.

Science.gov (United States)

Bou Samra, Patrick; El Tomb, Paul; Hosni, Mohammad; Kassem, Ahmad; Rizk, Robin; Shayya, Sami; Assaad, Sarah

2017-12-01

This comparative cross-sectional study examines the association between traffic congestion and elevation of systolic and/or diastolic blood pressure levels among a convenience sample of 310 drivers. Data collection took place during a gas station pause at a fixed time of day. Higher average systolic (142 vs 123 mm Hg) and diastolic (87 vs 78 mm Hg) blood pressures were detected among drivers exposed to traffic congestion compared with those who were not exposed (P<.001), while controlling for body mass index, age, sex, pack-year smoking, driving hours per week, and occupational driving. Moreover, among persons exposed to traffic congestion, longer exposure time was associated with higher systolic and diastolic blood pressures. Further studies are needed to better understand the mechanisms of the significant association between elevated blood pressure and traffic congestion. ©2017 Wiley Periodicals, Inc.

Chest ultrasound and hidden lung congestion in peritoneal dialysis patients.

Science.gov (United States)

Panuccio, Vincenzo; Enia, Giuseppe; Tripepi, Rocco; Torino, Claudia; Garozzo, Maurizio; Battaglia, Giovanni Giorgio; Marcantoni, Carmelita; Infantone, Lorena; Giordano, Guido; De Giorgi, Maria Loreta; Lupia, Mario; Bruzzese, Vincenzo; Zoccali, Carmine

2012-09-01

Chest ultrasound (US) is a non-invasive well-validated technique for estimating extravascular lung water (LW) in patients with heart diseases and in end-stage renal disease. We systematically applied this technique to the whole peritoneal dialysis (PD) population of five dialysis units. We studied the cross-sectional association between LW, echocardiographic parameters, clinical [pedal oedema, New York Heart Association (NYHA) class] and bioelectrical impedance analysis (BIA) markers of volume status in 88 PD patients. Moderate to severe lung congestion was evident in 41 (46%) patients. Ejection fraction was the echocardiographic parameter with the strongest independent association with LW (r = -0.40 P = 0.002). Oedema did not associate with LW on univariate and multivariate analysis. NYHA class was slightly associated with LW (r = 0.21 P = 0.05). Among patients with severe lung congestion, only 27% had pedal oedema and the majority (57%) had no dyspnoea (NYHA Class I). Similarly, the prevalence of patients with BIA, evidence of volume excess was small (11%) and not significantly different (P = 0.79) from that observed in patients with mild or no congestion (9%). In PD patients, LW by chest US reveals moderate to severe lung congestion in a significant proportion of asymptomatic patients. Intervention studies are necessary to prove the usefulness of chest US for optimizing the control of fluid excess in PD patients.

Riding the Electricity Market as an Energy Management Strategy: Savings from Real-Time Pricing

Energy Technology Data Exchange (ETDEWEB)

Chiles, Thomas [U.S. General Services Administration, Washington, D.C. (United States); Shutika, Kenneth [U.S. General Services Administration, Washington, D.C. (United States); Coleman, Philip [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2018-03-13

Dynamic pricing of electricity, in which retail prices facing customers are responsive to changes in the underlying wholesale markets, represents a step towards economic efficiency in that customers get exposed to some or all of the costs facing wholesale market players. But what do customers who opt for this greater exposure – available in the roughly 15 “de-regulated” states, as well as, to some extent, from some regulated utilities – get in return for their risks? The U.S. General Services Administration (GSA) took a retrospective eight-year look at what the savings would have been had they let the loads for which they purchase electricity in the Washington, DC area buy electricity on the real-time pricing (RTP) market – the dynamic pricing option with the highest risk – as opposed to the strategy they chose in actuality, which was fixing flat prices with 3rd-party providers. We found that opting for RTP for the eight years of the study (2005 through 2012) would have resulted in 17% savings, or almost a quarter of a billion dollars, relative to GSA’s actual prices from the 3rd-party suppliers. This is particularly astonishing given that GSA appeared to have timed the market well during the study period, consistently beating the standard offer products provided by the distribution utilities. The issue of budgetary predictability poses an obstacle for customers (especially government ones) considering RTP and, to a lesser extent, other dynamic pricing options. Indeed, GSA would have lost money with RTP in two of the eight years, one of them substantially. But the magnitude of the savings is indisputably compelling and, even if it may be somewhat aberrational due to high congestion in the DC market, begs consideration by large electricity users currently paying to “lock in” fixed flat prices.

Real time driver information for congestion management.

Science.gov (United States)

2015-07-01

Traffic demand in the U.S. has grown substantially over the past few years because of the increase in population and : urbanization in large cities. This causes traffic congestion to spread out over U.S. highways and arterials, and subsequently : lea...

Traffic Congestion Detection System through Connected Vehicles and Big Data

Directory of Open Access Journals (Sweden)

Néstor Cárdenas-Benítez

2016-04-01

Full Text Available This article discusses the simulation and evaluation of a traffic congestion detection system which combines inter-vehicular communications, fixed roadside infrastructure and infrastructure-to-infrastructure connectivity and big data. The system discussed in this article permits drivers to identify traffic congestion and change their routes accordingly, thus reducing the total emissions of CO2 and decreasing travel time. This system monitors, processes and stores large amounts of data, which can detect traffic congestion in a precise way by means of a series of algorithms that reduces localized vehicular emission by rerouting vehicles. To simulate and evaluate the proposed system, a big data cluster was developed based on Cassandra, which was used in tandem with the OMNeT++ discreet event network simulator, coupled with the SUMO (Simulation of Urban MObility traffic simulator and the Veins vehicular network framework. The results validate the efficiency of the traffic detection system and its positive impact in detecting, reporting and rerouting traffic when traffic events occur.

Traffic Congestion Detection System through Connected Vehicles and Big Data.

Science.gov (United States)

Cárdenas-Benítez, Néstor; Aquino-Santos, Raúl; Magaña-Espinoza, Pedro; Aguilar-Velazco, José; Edwards-Block, Arthur; Medina Cass, Aldo

2016-04-28

This article discusses the simulation and evaluation of a traffic congestion detection system which combines inter-vehicular communications, fixed roadside infrastructure and infrastructure-to-infrastructure connectivity and big data. The system discussed in this article permits drivers to identify traffic congestion and change their routes accordingly, thus reducing the total emissions of CO₂ and decreasing travel time. This system monitors, processes and stores large amounts of data, which can detect traffic congestion in a precise way by means of a series of algorithms that reduces localized vehicular emission by rerouting vehicles. To simulate and evaluate the proposed system, a big data cluster was developed based on Cassandra, which was used in tandem with the OMNeT++ discreet event network simulator, coupled with the SUMO (Simulation of Urban MObility) traffic simulator and the Veins vehicular network framework. The results validate the efficiency of the traffic detection system and its positive impact in detecting, reporting and rerouting traffic when traffic events occur.

Congestion management of electric distribution networks through market based methods

DEFF Research Database (Denmark)

Huang, Shaojun

 EVs and HPs. Market-based congestion management methods are the focus of the thesis. They handle the potential congestion at the energy planning stage; therefore, the aggregators can optimally plan the energy consumption and have the least impact on the customers. After reviewing and identifying...... the shortcomings of the existing methods, the thesis fully studies and improves the dynamic tariff (DT) method, and proposes two  new market-based  congestion management methods,  namely the  dynamic subsidy (DS) method and the flexible demand swap method. The thesis improves the DT method from four aspects......Rapidly increasing share of intermittent renewable energy production poses a great challenge of the management and operation of the modern power systems. Deployment of a large number of flexible demands, such as electrical vehicles (EVs) and heat pumps (HPs), is believed to be a promising solution...

Electric Vehicle Smart Charging using Dynamic Price Signal

DEFF Research Database (Denmark)

Martinenas, Sergejus; Pedersen, Anders Bro; Marinelli, Mattia

2014-01-01

, however, be resolved by using intelligent EV charging strategies, commonly referred to as ”Smart Charging”. The basic approach involves modifying the default vehicle charging scheme of ”immediate charging”, to a more optimal one that is derived from insight into the current state of the grid. This work......With yearly increases in Electric Vehicle (EV) sales, the future for electric mobility continues to brighten, and with more vehicles hitting the roads every day, the energy requirements on the grid will increase, potentially causing low-voltage distribution grid congestion. This problem can...... proposed in this paper, involves a real-time control strategy for charging the EV using a dynamic price tariff, with the objective of minimizing the charging cost. Two different charging scenario are investigated, and the results are verified by experiments on a real Electric Vehicle. Finally, the costs...

A Game Theory Based Congestion Control Protocol for Wireless Personal Area Networks

Directory of Open Access Journals (Sweden)

Chuang Ma

2016-01-01

Full Text Available In wireless sensor networks (WSNs, the presence of congestion increases the ratio of packet loss and energy consumption and reduces the network throughput. Particularly, this situation will be more complex in Internet of Things (IoT environment, which is composed of thousands of heterogeneous nodes. RPL is an IPv6 routing protocol in low power and lossy networks standardized by IETF. However, the RPL can induce problems under network congestion, such as frequently parent changing and throughput degradation. In this paper, we address the congestion problem between parent nodes and child nodes in RPL-enabled networks, which typically consist of low power and resource constraint devices. To mitigate the effect of network congestion, we design a parent-change procedure by game theory strategy, by which the child nodes can change next hop neighbors toward the sink. Comparing to the ContikiRPL implementation, the simulation results show that our protocol can achieve more than two times improvement in throughput and reduce packet loss rate with less increasing of average hop count.

Existence for stationary mean-field games with congestion and quadratic Hamiltonians

KAUST Repository

Gomes, Diogo A.

2015-09-03

Here, we investigate the existence of solutions to a stationary mean-field game model introduced by J.-M. Lasry and P.-L. Lions. This model features a quadratic Hamiltonian and congestion effects. The fundamental difficulty of potential singular behavior is caused by congestion. Thanks to a new class of a priori bounds, combined with the continuation method, we prove the existence of smooth solutions in arbitrary dimensions. © 2015 Springer Basel

Short paper: Distributed vehicular traffic congestion detection algorithm for urban environments

OpenAIRE

Milojevic, M.; Rakocevic, V.

2013-01-01

Vehicular traffic congestion is a well-known economic and social problem generating significant costs and safety challenges, and increasing pollution in the cities. Current intelligent transport systems and vehicular networking technologies rely heavily on the supporting network infrastructure which is still not widely available. This paper contributes towards the development of distributed and cooperative vehicular traffic congestion detection by proposing a new vehicle-to-vehicle (V2V) cong...

7 CFR 1000.50 - Class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Class prices, component prices, and advanced pricing... advanced pricing factors. Class prices per hundredweight of milk containing 3.5 percent butterfat, component prices, and advanced pricing factors shall be as follows. The prices and pricing factors described...

CCS_WHMS: A Congestion Control Scheme for Wearable Health Management System.

Science.gov (United States)

Kafi, Mohamed Amine; Ben Othman, Jalel; Bagaa, Miloud; Badache, Nadjib

2015-12-01

Wearable computing is becoming a more and more attracting field in the last years thanks to the miniaturisation of electronic devices. Wearable healthcare monitoring systems (WHMS) as an important client of wearable computing technology has gained a lot. Indeed, the wearable sensors and their surrounding healthcare applications bring a lot of benefits to patients, elderly people and medical staff, so facilitating their daily life quality. But from a research point of view, there is still work to accomplish in order to overcome the gap between hardware and software parts. In this paper, we target the problem of congestion control when all these healthcare sensed data have to reach the destination in a reliable manner that avoids repetitive transmission which wastes precious energy or leads to loss of important information in emergency cases, too. We propose a congestion control scheme CCS_WHMS that ensures efficient and fair data delivery while used in the body wearable system part or in the multi-hop inter bodies wearable ones to get the destination. As the congestion detection paradigm is very important in the control process, we do experimental tests to compare between state of the art congestion detection methods, using MICAz motes, in order to choose the appropriate one for our scheme.

CONGESTION CONTROL IMPROVED QoS ROUTING SCHEME FOR WIRELESS SENSOR NETWORK

OpenAIRE

A. Elakkiya*, B. Santhana Krishnan, Dr. M. Ramaswamy

2016-01-01

Wireless sensor network is distributed self-governing sensors used to monitor the physical conditions of the environment. They are constructed by nodes where each of them is connected to sensors. These sensor nodes acquire real time information and transmit the information. When large number of sensor nodes are active in transmitting the information there is a possibility of congestion in the data packets. Congestion occurs due to buffer overflow, channel contention, packet collision, reporti...

Lung congestion in chronic heart failure: haemodynamic, clinical, and prognostic implications

DEFF Research Database (Denmark)

Melenovsky, Vojtech; Andersen, Mads Jønsson; Andress, Krystof

2015-01-01

AIMS:The goal of the study was to examine the prognostic impact, haemodynamic and clinical features associated with lung congestion in patients with chronic heart failure (HF). METHODS AND RESULTS:HF patients (n = 186) and HF-free controls (n = 21) underwent right heart catheterization...... days (interquartile range 80-875), 59 patients (32%) died. Lung congestion was associated with reduced survival (P renal dysfunction. CONCLUSION:Interstitial lung oedema is associated with pulmonary vascular disease, RV overload...

Congestion estimation technique in the optical network unit registration process.

Science.gov (United States)

Kim, Geunyong; Yoo, Hark; Lee, Dongsoo; Kim, Youngsun; Lim, Hyuk

2016-07-01

We present a congestion estimation technique (CET) to estimate the optical network unit (ONU) registration success ratio for the ONU registration process in passive optical networks. An optical line terminal (OLT) estimates the number of collided ONUs via the proposed scheme during the serial number state. The OLT can obtain congestion level among ONUs to be registered such that this information may be exploited to change the size of a quiet window to decrease the collision probability. We verified the efficiency of the proposed method through simulation and experimental results.

Impact Analysis of Land Use on Traffic Congestion Using Real-Time Traffic and POI

OpenAIRE

Zhang, Tianqi; Sun, Lishan; Yao, Liya; Rong, Jian

2017-01-01

This paper proposed a new method to describe, compare, and classify the traffic congestion points in Beijing, China, by using the online map data and further revealed the relationship between traffic congestion and land use. The data of the point of interest (POI) and the real-time traffic was extracted from an electronic map of the area in the fourth ring road of Beijing. The POIs were quantified based on the architectural area of the land use; the congestion points were identified based on ...

Long Island Transportation Plan to Manage Congestion: Framework for Developing and Evaluating Improvement Strategies

Science.gov (United States)

2002-04-20

The Long Island Transportation Plan to Manage Congestion (LITP 2000) will establish an integrated, multi-modal transportation program of cost-effective strategies to manage congestion and improve the movement of people and goods in Nassau and Suffolk...

Launching automated rotary parking system: Towards traffic congestion free Dhaka city

Science.gov (United States)

Islam, Mohummad Shariful; Tithi, Afshana Morshed; Hossain, Farzad; Shetu, Rifat Sultana; Amin, S. M. Abdullah Al; Chowdhury, Shakia Zannatul Ferdous

2017-12-01

Bangladesh is the most densely populated city in the whole world, which is visible more in the capital city Dhaka. People have to suffer and valuable times are being wasted for this chronic quandary. Lack of proper planning of the city, different speed vehicles on the same road, over population, inadequate road space, unplanned stoppage or parking etc. are responsible for causing the traffic congestion in Dhaka City. Among those insufficient/unplanned parking system is one of the main reasons for causing traffic congestion. The automated rotary car parking system is the best and suitable because of its less utilization of space compared to other systems. It is a friendly parking system due to the non-utilization of noise/pollution related mechanism. The aim of this paper is to develop an automated car parking system with a minimum cost for reducing congestion in Dhaka city.

Chronic congestive heart failure is associated with a phenotypic shift of intramyocardial endothelial cells

NARCIS (Netherlands)

Marijianowski, M. M.; van Laar, M.; Bras, J.; Becker, A. E.

1995-01-01

There is evidence that patients with chronic congestive heart failure have endothelial cell-related abnormalities of the peripheral circulation and the coronary microvasculature. For that reason, we have studied the phenotypic expression of endothelial cells in hearts of patients with congestive

Pulmonary Vascular Congestion: A Mechanism for Distal Lung Unit Dysfunction in Obesity.

Science.gov (United States)

Oppenheimer, Beno W; Berger, Kenneth I; Ali, Saleem; Segal, Leopoldo N; Donnino, Robert; Katz, Stuart; Parikh, Manish; Goldring, Roberta M

2016-01-01

Obesity is characterized by increased systemic and pulmonary blood volumes (pulmonary vascular congestion). Concomitant abnormal alveolar membrane diffusion suggests subclinical interstitial edema. In this setting, functional abnormalities should encompass the entire distal lung including the airways. We hypothesize that in obesity: 1) pulmonary vascular congestion will affect the distal lung unit with concordant alveolar membrane and distal airway abnormalities; and 2) the degree of pulmonary congestion and membrane dysfunction will relate to the cardiac response. 54 non-smoking obese subjects underwent spirometry, impulse oscillometry (IOS), diffusion capacity (DLCO) with partition into membrane diffusion (DM) and capillary blood volume (VC), and cardiac MRI (n = 24). Alveolar-capillary membrane efficiency was assessed by calculation of DM/VC. Mean age was 45±12 years; mean BMI was 44.8±7 kg/m2. Vital capacity was 88±13% predicted with reduction in functional residual capacity (58±12% predicted). Despite normal DLCO (98±18% predicted), VC was elevated (135±31% predicted) while DM averaged 94±22% predicted. DM/VC varied from 0.4 to 1.4 with high values reflecting recruitment of alveolar membrane and low values indicating alveolar membrane dysfunction. The most abnormal IOS (R5 and X5) occurred in subjects with lowest DM/VC (r2 = 0.31, ppulmonary vascular congestion and failure to achieve the high output state of obesity. Pulmonary vascular congestion and consequent fluid transudation and/or alterations in the structure of the alveolar capillary membrane may be considered often unrecognized causes of airway dysfunction in obesity.

Update in cardiomyopathies and congestive heart failure

Directory of Open Access Journals (Sweden)

The Heart Hospital, London, UK and Monaldi Hospital, Naples, Italy

2012-05-01

Full Text Available This abstract book contains four reports and all abstracts presented to the Joint Meeting: Update in cardiomyopathies and congestive heart failure, 22-23 September 2011 - Naples, Italy, endorsed by the Working Group on Myocardial and Pericardial Diseases (WG 21 of the European Society of Cardiology (ESC.

Cross-Layer Active Predictive Congestion Control Protocol for Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Yinfeng Wu

2009-10-01

Full Text Available In wireless sensor networks (WSNs, there are numerous factors that may cause network congestion problems, such as the many-to-one communication modes, mutual interference of wireless links, dynamic changes of network topology and the memory-restrained characteristics of nodes. All these factors result in a network being more vulnerable to congestion. In this paper, a cross-layer active predictive congestion control scheme (CL-APCC for improving the performance of networks is proposed. Queuing theory is applied in the CL-APCC to analyze data flows of a single-node according to its memory status, combined with the analysis of the average occupied memory size of local networks. It also analyzes the current data change trends of local networks to forecast and actively adjust the sending rate of the node in the next period. In order to ensure the fairness and timeliness of the network, the IEEE 802.11 protocol is revised based on waiting time, the number of the node‟s neighbors and the original priority of data packets, which dynamically adjusts the sending priority of the node. The performance of CL-APCC, which is evaluated by extensive simulation experiments. is more efficient in solving the congestion in WSNs. Furthermore, it is clear that the proposed scheme has an outstanding advantage in terms of improving the fairness and lifetime of networks.

Cross-layer active predictive congestion control protocol for wireless sensor networks.

Science.gov (United States)

Wan, Jiangwen; Xu, Xiaofeng; Feng, Renjian; Wu, Yinfeng

2009-01-01

In wireless sensor networks (WSNs), there are numerous factors that may cause network congestion problems, such as the many-to-one communication modes, mutual interference of wireless links, dynamic changes of network topology and the memory-restrained characteristics of nodes. All these factors result in a network being more vulnerable to congestion. In this paper, a cross-layer active predictive congestion control scheme (CL-APCC) for improving the performance of networks is proposed. Queuing theory is applied in the CL-APCC to analyze data flows of a single-node according to its memory status, combined with the analysis of the average occupied memory size of local networks. It also analyzes the current data change trends of local networks to forecast and actively adjust the sending rate of the node in the next period. In order to ensure the fairness and timeliness of the network, the IEEE 802.11 protocol is revised based on waiting time, the number of the node's neighbors and the original priority of data packets, which dynamically adjusts the sending priority of the node. The performance of CL-APCC, which is evaluated by extensive simulation experiments. is more efficient in solving the congestion in WSNs. Furthermore, it is clear that the proposed scheme has an outstanding advantage in terms of improving the fairness and lifetime of networks.

The congestion control algorithm based on queue management of each node in mobile ad hoc networks

Science.gov (United States)

Wei, Yifei; Chang, Lin; Wang, Yali; Wang, Gaoping

2016-12-01

This paper proposes an active queue management mechanism, considering the node's own ability and its importance in the network to set the queue threshold. As the network load increases, local congestion of mobile ad hoc network may lead to network performance degradation, hot node's energy consumption increase even failure. If small energy nodes congested because of forwarding data packets, then when it is used as the source node will cause a lot of packet loss. This paper proposes an active queue management mechanism, considering the node's own ability and its importance in the network to set the queue threshold. Controlling nodes buffer queue in different levels of congestion area probability by adjusting the upper limits and lower limits, thus nodes can adjust responsibility of forwarding data packets according to their own situation. The proposed algorithm will slow down the send rate hop by hop along the data package transmission direction from congestion node to source node so that to prevent further congestion from the source node. The simulation results show that, the algorithm can better play the data forwarding ability of strong nodes, protect the weak nodes, can effectively alleviate the network congestion situation.

Congestive cardiomyopathy and endobronchial granulomas as manifestations of Churg-Strauss syndrome.

Science.gov (United States)

Alvarez-Sala, R.; Prados, C.; Armada, E.; Del Arco, A.; Villamor, J.

1995-01-01

Churg-Strauss syndrome is a systemic vasculitis. Its most frequent complications are heart diseases and asthma. Usually, cardiological manifestations are pericarditis, cardiac failure and myocardial infarction. Endobronchial granulomas identified by bronchoscopy are unusual. We present the case of a man with congestive cardiomyopathy and endobronchial granulomas macroscopically visible at bronchoscopy. After a review of medical literature, we found one case of congestive cardiomyopathy and no cases of endobronchial granulomas observed by bronchoscopy associated with Churg-Strauss syndrome. Images Figure PMID:7644400

CSRNet: Dilated Convolutional Neural Networks for Understanding the Highly Congested Scenes

OpenAIRE

Li, Yuhong; Zhang, Xiaofan; Chen, Deming

2018-01-01

We propose a network for Congested Scene Recognition called CSRNet to provide a data-driven and deep learning method that can understand highly congested scenes and perform accurate count estimation as well as present high-quality density maps. The proposed CSRNet is composed of two major components: a convolutional neural network (CNN) as the front-end for 2D feature extraction and a dilated CNN for the back-end, which uses dilated kernels to deliver larger reception fields and to replace po...

Design, Implementation and Evaluation of Congestion Control Mechanism for Video Streaming

OpenAIRE

Hiroshi Noborio; Hiroyuki Hisamatsu; Hiroki Oda

2011-01-01

In recent years, video streaming services over TCP, such as YouTube, have become more and more popular. TCP NewReno, the current TCP standard, performs greedy congestion control, which increases the congestion window size until packet loss occurs. Therefore, because TCP transmits data at a much higher rate than the video playback rate, the probability of packet loss in the network increases, which in turn takes bandwidth from other network traffic. In this paper, we propose a new transport-la...

Temporal-Spatial Analysis of Traffic Congestion Based on Modified CTM

Directory of Open Access Journals (Sweden)

Chenglong Chu

2015-01-01

Full Text Available A modified cell transmission model (CTM is proposed to depict the temporal-spatial evolution of traffic congestion on urban freeways. Specifically, drivers’ adaptive behaviors and the corresponding influence on traffic flows are emphasized. Two piecewise linear regression models are proposed to describe the relationship of flow and density (occupancy. Several types of cellular connections are designed to depict urban rapid roads with on/off-ramps and junctions. Based on the data collected on freeway of Queen Elizabeth, Ontario, Canada, we show that the new model provides a relatively higher accuracy of temporal-spatial evolution of traffic congestions.

Game theoretic analysis of congestion, safety and security networks, air traffic and emergency departments

CERN Document Server

Zhuang, Jun

2015-01-01

Maximizing reader insights into the roles of intelligent agents in networks, air traffic and emergency departments, this volume focuses on congestion in systems where safety and security are at stake, devoting special attention to applying game theoretic analysis of congestion to: protocols in wired and wireless networks; power generation, air transportation and emergency department overcrowding. Reviewing exhaustively the key recent research into the interactions between game theory, excessive crowding, and safety and security elements, this book establishes a new research angle by illustrating linkages between the different research approaches and serves to lay the foundations for subsequent analysis. Congestion (excessive crowding) is defined in this work as all kinds of flows; e.g., road/sea/air traffic, people, data, information, water, electricity, and organisms. Analyzing systems where congestion occurs – which may be in parallel, series, interlinked, or interdependent, with flows one way or both way...

A Study of the Effects of Congestion Information and a Priority Boarding Pass in a Theme Park with Multi-Agents

Science.gov (United States)

Tone, Tetsuya; Kohara, Kazuhiro

We have investigated ways to reduce congestion in a theme park with multi-agents. We constructed a theme park model called Digital Park 1.0 with twenty-three attractions similar in form to Tokyo Disney Sea. We consider not only congestion information (number of vistors standing in line at each attraction) but also the advantage of a priority boarding pass, like Fast Pass which is used at Tokyo Disney Sea. The congestion-information-usage ratio, which reflects the ratio of visitors who behave according to congestion information, was changed from 0% to 100% in both models, with and without priority boarding pass. The “mean stay time of visitors" is a measure of satisfaction. The smaller mean stay time, the larger degree of satisfaction. Here, a short stay time means a short wait time. The resluts of each simulation are averaged over ten trials. The main results are as follows. (1) When congestion-information-usage ratio increased, the mean stay time decreases. When 20% of visitors behaved according to congestion information, the mean stay time was reduced by 30%. (2) A priority boarding pass reduced congestion, and mean stay time was reduced by 15%. (3) When visitors used congestion information and a priority boarding pass, mean stay time was further reduced. When the congestion-information-usage ratio was 20%, mean stay time was reduced by 35%. (4) When congestion-information-usage ratio was over 50%, the congestion reduction effects reached saturation.

Assessment of congestive heart failure in chest radiographs

International Nuclear Information System (INIS)

Henriksson, L.; Sundin, A.; Smedby, Oe.; Albrektsson, P.

1990-01-01

The effect of observer variations and film-screen quality on the diagnosis of congestive heart failure based on chest radiographs was studied in 27 patients. For each patient, two films were exposed, one with the Kodak Lanex Medium system and one with the Agfa MR 400 system. The films were presented to three observers who assessed the presence of congestive heart failure on a three-graded scale. The results showed no significant difference between the two systems but large systematic differences between the observers. There were also differences between the two ratings by the same observer that could not be explained by the film-screen factor. It is concluded that the choice between these two systems is of little importance in view of the interobserver and intraobserver variability that can exist within the same department. (orig.)

Viability of a New Road Infrastructure with Heterogeneous Users in Madrid Access

OpenAIRE

Pedro Cantos-Sanchez; Rafael Moner-Colonques; Jose J. Sempere-Monerris; Oscar Alvarez

2008-01-01

This paper explores the importance of heterogeneity in value of time when assessing the viability of a new road infrastructure to alleviate congestion problems. The Spanish government has developed a congestion pricing demonstration entering Madrid city centre, where road users have to choose between a free but highly congested road and a priced free-flowing road. We consider a continuum of users who differ in their value of time. Users dislike congestion and this is more so the more a user v...

An endoscopic study of upper-GI mucosal changes in patients with congestive heart failure.

Science.gov (United States)

Raja, Kaiser; Kochhar, Rakesh; Sethy, Pradeepta K; Dutta, Usha; Bali, Harinder K; Varma, Jagmohan S

2004-12-01

Congestive heart failure results in an increase in systemic venous pressure that is transmitted to the inferior vena cava and to the hepatic veins. This can cause GI vascular and mucosal congestion. The aim of this study was to define upper-GI mucosal changes in patients with congestive heart failure. A total of 57 patients with congestive heart failure presenting with GI symptoms underwent upper endoscopy. Echocardiography was performed in all patients to determine the ejection fraction and the degree of tricuspid regurgitation. Transabdominal US was performed to measure the diameters of the hepatic veins, the inferior vena cava, and the portal vein. The presence and the severity of gastropathy and duodenopathy were compared with the parameters relating to severity of cardiac failure. Of the 57 patients studied, gastric mucosal changes were observed in 50 (88%), duodenal mucosal changes in 31 (54%), and esophageal mucosal changes in none. Gastric mucosal changes were the following: mosaic-like pattern (n = 50), punctate spots (n = 34), thickened folds (n = 5), watermelon stomach (n = 3), and telangiectasia (n = 10). Duodenal mucosal changes were the following: mosaic-like pattern (n = 29), thickened folds (n = 8), and telangiectasia (n = 2). Upper-GI symptoms were associated with gastropathy ( p = 0.027) and duodenopathy ( p = 0.003). The presence and the severity of duodenopathy showed a high degree of positive correlation with the presence and the severity of gastropathy (gamma value 0.690; p value <0.001). Patients with gastropathy and duodenopathy had higher mean inferior vena cava and hepatic vein diameters than those without gastropathy and duodenopathy. The severity of duodenopathy but not that of gastropathy was significantly associated with increasing severity of tricuspid regurgitation ( p = 0.001), larger portal vein diameter ( p = 0.02), and lower ejection fraction ( p = 0.008). Among patients with congestive cardiac failure with GI symptoms, changes

Impact of Incidents on Traffic Congestion in Dar es Salaam City

Directory of Open Access Journals (Sweden)

David Mfinanga

2013-06-01

Full Text Available Poorly managed traffic incidents have largely contributed to congestion and delay in the city of Dar es Salaam. A thorough understanding of travel delays caused by incidents is therefore essential for effective countermeasures against the increasing congestion. The method used to determine delays in this research is based on the deterministic queuing theory. Information on incidents was obtained from traffic surveys, traffic police and road users. Counting of the number of vehicles passing the incident location was done on incident and incident-free days. The cumulative traffic counts on incident and incident-free days were then calculated and used to plot the queuing diagram used to determine incident induced delay. This method turned out to be a useful tool for estimating incident induced delay in areas with less sophisticated equipment i.e. where there are no sensors, CCTV cameras, etc. The method provided good estimates of incident induced delay which may help planners and transportation officials in better understanding incident related congestion and in selecting more effective countermeasures against incident related traffic congestion in the city. It was found out that the effects of incidents were different for the different zones, types of incidents and the periods the incident occurred. In addition to the incident duration and the number of vehicles affected, the impact of incidents also depended on availability of alternative routes, number of lanes on the road, discipline of the driver in manoeuvring at incident location and traffic control at the scene.

Drug therapy for congestive heart failure:appropriate choices can prolong life

International Nuclear Information System (INIS)

Sorrentino, M

1997-01-01

Between one purpose of the insufficiency congestive heart is improve and prolong the quality life. A good multidisciplinary health equipment can help to the improving patients with this disease referred to effective handling interned and ambulatory patients groups. The inhibition mechanism compensate that perpetuate heart congestive insufficiency are a way for reach treatment purposes. Between patients with symptomatic cardiac insufficiency and overload volume is indicated digoxin(Lanoxin) and vasodilators. The enzyme inhibition angiotensin converted improve over life range more than an others vasodilators and is preferred for the systole dysfunction patients

New Brunswick Market Design Committee : Congestion management issues

International Nuclear Information System (INIS)

2001-01-01

The restructuring of the New Brunswick wholesale power market comprises a number of issues that need to be resolved concerning transmission system related policy decisions and detailed design issues. The wholesale market structure, ownership structure, and means of preventing market power abuses all have an impact on the resolution of many of those issues. Some transmission related decisions regarding congestion management must be made, and they are examined in this document. The report includes a discussion of the issues related to congestion on the transmission system, a review of the decisions that remain to be made while proposing a number of alternatives, reviews decisions that other jurisdictions have made in somewhat similar circumstances. Finally, the advantages and disadvantages of each alternative are identified. Several high level transmission tariff design issues requiring to be addressed later in greater detail are listed in this document. 1 tab

7 CFR 1124.50 - Class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Class prices, component prices, and advanced pricing factors. 1124.50 Section 1124.50 Agriculture Regulations of the Department of Agriculture (Continued... prices, and advanced pricing factors. See § 1000.50. ...

7 CFR 1030.50 - Class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Class prices, component prices, and advanced pricing factors. 1030.50 Section 1030.50 Agriculture Regulations of the Department of Agriculture (Continued... prices, and advanced pricing factors. See § 1000.50. ...

Gas prices and price process

International Nuclear Information System (INIS)

Groenewegen, G.G.

1992-01-01

On a conference (Gas for Europe in the 1990's) during the Gasexpo '91 the author held a speech of which the Dutch text is presented here. Attention is paid to the current European pricing methods (prices based on the costs of buying, transporting and distributing the natural gas and prices based on the market value, which is deducted from the prices of alternative fuels), and the transparency of the prices (lack of information on the way the prices are determined). Also attention is paid to the market signal transparency and gas-gas competition, which means a more or less free market of gas distribution. The risks of gas-to-gas competition for a long term price stability, investment policies and security of supply are discussed. Opposition against the Third Party Access (TPA), which is the program to implement gas-to-gas competition, is caused by the fear of natural gas companies for lower gas prices and lower profits. Finally attention is paid to government regulation and the activities of the European Commission (EC) in this matter. 1 fig., 6 ills., 1 tab

Congestion in a city with a central bottleneck

DEFF Research Database (Denmark)

Fosgerau, Mogens; Palma, André de

2010-01-01

We consider dynamic congestion in an urban setting where trip origins are spatially distributed. All travelers must pass through a downtown bottleneck in order to reach their destination in the CBD. Each traveler chooses departure time to maximize general concave scheduling utility. At equilibriu...

Congestion in a city with a central bottleneck

DEFF Research Database (Denmark)

Fosgerau, Mogens; Palma, André de

2012-01-01

We consider dynamic congestion in an urban setting where trip origins are spatially distributed. All travelers must pass through a downtown bottleneck in order to reach their destination in the CBD. Each traveler chooses departure time to maximize general concave scheduling utility. We find that,...

Game theoretic analysis of congestion, safety and security traffic and transportation theory

CERN Document Server

Zhuang, Jun

2015-01-01

Maximizing reader insights into the interactions between game theory, excessive crowding and safety and security elements in traffic and transportation theory, this book establishes a new research angle by illustrating linkages between different research approaches and through laying the foundations for subsequent analysis. Congestion (excessive crowding) is defined in this work as all kinds of flows; e.g., road/sea/air traffic, people, data, information, water, electricity, and organisms. Analyzing systems where congestion occurs – which may be in parallel, series, interlinked, or interdependent, with flows one way or both ways – this book puts forward new congestion models, breaking new ground by introducing game theory and safety/security. Addressing the multiple actors who may hold different concerns regarding system reliability; e.g. one or several terrorists, a government, various local or regional government agencies, or others with stakes for or against system reliability, this book describes how ...

Congestion and flow control in signaling system no. 7: Impacts of intelligent networks and new services

Science.gov (United States)

Zepf, Joachim; Rufa, Gerhard

1994-04-01

This paper focuses on the transient performance analysis of the congestion and flow control mechanisms in CCITT Signaling System No. 7 (SS7). Special attention is directed to the impacts of the introduction of intelligent services and new applications, e.g., Freephone, credit card services, user-to-user signaling, etc. In particular, we show that signaling traffic characteristics like signaling scenarios or signaling message length as well as end-to-end signaling capabilities have a significant influence on the congestion and flow control and, therefore, on the real-time signaling performance. One important result of our performance studies is that if, e.g., intelligent services are introduced, the SS7 congestion and flow control does not work correctly. To solve this problem, some reinvestigations into these mechanisms would be necessary. Therefore, some approaches, e.g., modification of the Signaling Connection Control Part (SCCP) congestion control, usage of the SCCP relay function, or a redesign of the MTP flow control procedures are discussed in order to guarantee the efficacy of the congestion and flow control mechanisms also in the future.

Sensitivities and Tipping Points of Power System Operations to Fluctuations Caused by Water Availability and Fuel Prices

Science.gov (United States)

O'Connell, M.; Macknick, J.; Voisin, N.; Fu, T.

2017-12-01

The western US electric grid is highly dependent upon water resources for reliable operation. Hydropower and water-cooled thermoelectric technologies represent 67% of generating capacity in the western region of the US. While water resources provide a significant amount of generation and reliability for the grid, these same resources can represent vulnerabilities during times of drought or low flow conditions. A lack of water affects water-dependent technologies and can result in more expensive generators needing to run in order to meet electric grid demand, resulting in higher electricity prices and a higher cost to operate the grid. A companion study assesses the impact of changes in water availability and air temperatures on power operations by directly derating hydro and thermo-electric generators. In this study we assess the sensitivities and tipping points of water availability compared with higher fuel prices in electricity sector operations. We evaluate the impacts of varying electricity prices by modifying fuel prices for coal and natural gas. We then analyze the difference in simulation results between changes in fuel prices in combination with water availability and air temperature variability. We simulate three fuel price scenarios for a 2010 baseline scenario along with 100 historical and future hydro-climate conditions. We use the PLEXOS electricity production cost model to optimize power system dispatch and cost decisions under each combination of fuel price and water constraint. Some of the metrics evaluated are total production cost, generation type mix, emissions, transmission congestion, and reserve procurement. These metrics give insight to how strained the system is, how much flexibility it still has, and to what extent water resource availability or fuel prices drive changes in the electricity sector operations. This work will provide insights into current electricity operations as well as future cases of increased penetration of variable

The effects of congestions tax on air quality and health

Science.gov (United States)

Johansson, Christer; Burman, Lars; Forsberg, Bertil

The "Stockholm Trial" involved a road pricing system to improve the air quality and reduce traffic congestion. The test period of the trial was January 3-July 31, 2006. Vehicles travelling into and out of the charge cordon were charged for every passage during weekdays. The amount due varied during the day and was highest during rush hours (20 SEK = 2.2 EUR, maximum 60 SEK per day). Based on measured and modelled changes in road traffic it was estimated that this system resulted in a 15% reduction in total road use within the charged cordon. Total traffic emissions in this area of NO x and PM10 fell by 8.5% and 13%, respectively. Air quality dispersion modelling was applied to assess the effect of the emission reductions on ambient concentrations and population exposure. For the situations with and without the trial, meteorological conditions and other emissions than from road traffic were kept the same. The calculations show that, with a permanent congestion tax system like the Stockholm Trial, the annual average NO x concentrations would be lower by up to 12% along the most densely trafficked streets. PM10 concentrations would be up to 7% lower. The limit values for both PM10 and NO 2 would still be exceeded along the most densely trafficked streets. The total population exposure of NO x in Greater Stockholm (35 × 35 km with 1.44 million people) is estimated to decrease with a rather modest 0.23 μg m -3. However, based on a long-term epidemiological study, that found an increased mortality risk of 8% per 10 μg m -3 NO x, it is estimated that 27 premature deaths would be avoided every year. According to life-table analysis this would correspond to 206 years of life gained over 10 years per 100 000 people following the trial if the effects on exposures would persist. The effect on mortality is attributed to road traffic emissions (likely vehicle exhaust particles); NO x is merely regarded as an indicator of traffic exposure. This is only the tip of the ice

Modelling and experimental study for automated congestion driving

NARCIS (Netherlands)

Urhahne, Joseph; Piastowski, P.; van der Voort, Mascha C.; Bebis, G; Boyle, R.; Parvin, B.; Koracin, D.; Pavlidis, I.; Feris, R.; McGraw, T.; Elendt, M.; Kopper, R.; Ragan, E.; Ye, Z.; Weber, G.

2015-01-01

Taking a collaborative approach in automated congestion driving with a Traffic Jam Assist system requires the driver to take over control in certain traffic situations. In order to warn the driver appropriately, warnings are issued (“pay attention” vs. “take action”) due to a control transition

Advanced carrier sensing to resolve local channel congestion

NARCIS (Netherlands)

Schmidt, Robert K.; Brakemeier, Achim; Leinmüller, Tim; Kargl, Frank; Schäfer, Günther

Communication performance in VANETs under high channel load is significantly degraded due to packet collisions and messages drops, also referred to as local channel congestion. So far, research was focused on the control of transmit power and the limitation of the messages rate to mitigate the

Cost recovery of congested infrastructure under market power

NARCIS (Netherlands)

Verhoef, Erik T.

2017-01-01

The Mohring–Harwitz (1962) theorem states that the degree of self-financing of congested infrastructure is equal to the elasticity of the capacity cost function in the optimum, so that under neutral scale economies exact self-financing applies. The theorem breaks down when the infrastructure is used

Congestion Control and Traffic Scheduling for Collaborative Crowdsourcing in SDN Enabled Mobile Wireless Networks

Directory of Open Access Journals (Sweden)

Dawei Shen

2018-01-01

Full Text Available Currently, a number of crowdsourcing-based mobile applications have been implemented in mobile networks and Internet of Things (IoT, targeted at real-time services and recommendation. The frequent information exchanges and data transmissions in collaborative crowdsourcing are heavily injected into the current communication networks, which poses great challenges for Mobile Wireless Networks (MWN. This paper focuses on the traffic scheduling and load balancing problem in software-defined MWN and designs a hybrid routing forwarding scheme as well as a congestion control algorithm to achieve the feasible solution. The traffic scheduling algorithm first sorts the tasks in an ascending order depending on the amount of tasks and then solves it using a greedy scheme. In the proposed congestion control scheme, the traffic assignment is first transformed into a multiknapsack problem, and then the Artificial Fish Swarm Algorithm (AFSA is utilized to solve this problem. Numerical results on practical network topology reveal that, compared with the traditional schemes, the proposed congestion control and traffic scheduling schemes can achieve load balancing, reduce the probability of network congestion, and improve the network throughput.

Dynamic Traffic Congestion Simulation and Dissipation Control Based on Traffic Flow Theory Model and Neural Network Data Calibration Algorithm

Directory of Open Access Journals (Sweden)

Li Wang

2017-01-01

Full Text Available Traffic congestion is a common problem in many countries, especially in big cities. At present, China’s urban road traffic accidents occur frequently, the occurrence frequency is high, the accident causes traffic congestion, and accidents cause traffic congestion and vice versa. The occurrence of traffic accidents usually leads to the reduction of road traffic capacity and the formation of traffic bottlenecks, causing the traffic congestion. In this paper, the formation and propagation of traffic congestion are simulated by using the improved medium traffic model, and the control strategy of congestion dissipation is studied. From the point of view of quantitative traffic congestion, the paper provides the fact that the simulation platform of urban traffic integration is constructed, and a feasible data analysis, learning, and parameter calibration method based on RBF neural network is proposed, which is used to determine the corresponding decision support system. The simulation results prove that the control strategy proposed in this paper is effective and feasible. According to the temporal and spatial evolution of the paper, we can see that the network has been improved on the whole.

Short-time existence of solutions for mean-field games with congestion

KAUST Repository

Gomes, Diogo A.

2015-11-20

We consider time-dependent mean-field games with congestion that are given by a Hamilton–Jacobi equation coupled with a Fokker–Planck equation. These models are motivated by crowd dynamics in which agents have difficulty moving in high-density areas. The congestion effects make the Hamilton–Jacobi equation singular. The uniqueness of solutions for this problem is well understood; however, the existence of classical solutions was only known in very special cases, stationary problems with quadratic Hamiltonians and some time-dependent explicit examples. Here, we demonstrate the short-time existence of C∞ solutions for sub-quadratic Hamiltonians.

A Survey of Congestion Control Techniques and Data Link Protocols in Satellite Networks

OpenAIRE

Fahmy, Sonia; Jain, Raj; Lu, Fang; Kalyanaraman, Shivkumar

1998-01-01

Satellite communication systems are the means of realizing a global broadband integrated services digital network. Due to the statistical nature of the integrated services traffic, the resulting rate fluctuations and burstiness render congestion control a complicated, yet indispensable function. The long propagation delay of the earth-satellite link further imposes severe demands and constraints on the congestion control schemes, as well as the media access control techniques and retransmissi...

Relating price strategies and price-setting practices

NARCIS (Netherlands)

Ingenbleek, P.T.M.; Lans, van der I.A.

2013-01-01

Purpose - This article addresses the relationship between price strategies and price-setting practices. The first derive from a normative tradition in the pricing literature and the latter from a descriptive tradition. Price strategies are visible in the market, whereas price-setting practices are

Mitigation of airspace congestion impact on airline networks

DEFF Research Database (Denmark)

Vaaben, Bo Valdemar; Larsen, Jesper

2015-01-01

In recent years European airspace has become increasingly congested and airlines can now observe that en-route capacity constraints are the fastest growing source of flight delays. In 2010 this source of delay accounted for 19% of all flight delays in Europe and has been increasing with an average...

7 CFR 1131.53 - Announcement of class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Announcement of class prices, component prices, and advanced pricing factors. 1131.53 Section 1131.53 Agriculture Regulations of the Department of Agriculture... class prices, component prices, and advanced pricing factors. See § 1000.53. ...

7 CFR 1005.53 - Announcement of class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Announcement of class prices, component prices, and advanced pricing factors. 1005.53 Section 1005.53 Agriculture Regulations of the Department of Agriculture... class prices, component prices, and advanced pricing factors. See § 1000.53. ...

7 CFR 1126.53 - Announcement of class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Announcement of class prices, component prices, and advanced pricing factors. 1126.53 Section 1126.53 Agriculture Regulations of the Department of Agriculture... class prices, component prices, and advanced pricing factors. See § 1000.53. ...

7 CFR 1032.53 - Announcement of class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Announcement of class prices, component prices, and advanced pricing factors. 1032.53 Section 1032.53 Agriculture Regulations of the Department of Agriculture... class prices, component prices, and advanced pricing factors. See § 1000.53. ...

7 CFR 1030.53 - Announcement of class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Announcement of class prices, component prices, and advanced pricing factors. 1030.53 Section 1030.53 Agriculture Regulations of the Department of Agriculture... of class prices, component prices, and advanced pricing factors. See § 1000.53. ...

7 CFR 1033.53 - Announcement of class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Announcement of class prices, component prices, and advanced pricing factors. 1033.53 Section 1033.53 Agriculture Regulations of the Department of Agriculture... class prices, component prices, and advanced pricing factors. See § 1000.53. ...

7 CFR 1001.53 - Announcement of class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Announcement of class prices, component prices, and advanced pricing factors. 1001.53 Section 1001.53 Agriculture Regulations of the Department of Agriculture... class prices, component prices, and advanced pricing factors. See § 1000.53. ...

7 CFR 1007.53 - Announcement of class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Announcement of class prices, component prices, and advanced pricing factors. 1007.53 Section 1007.53 Agriculture Regulations of the Department of Agriculture... class prices, component prices, and advanced pricing factors. See § 1000.53. ...

7 CFR 1006.53 - Announcement of class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Announcement of class prices, component prices, and advanced pricing factors. 1006.53 Section 1006.53 Agriculture Regulations of the Department of Agriculture... class prices, component prices, and advanced pricing factors. See § 1000.53. ...

7 CFR 1033.50 - Class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Class prices, component prices, and advanced pricing factors. 1033.50 Section 1033.50 Agriculture Regulations of the Department of Agriculture (Continued..., and advanced pricing factors. See § 1000.50. ...

7 CFR 1005.50 - Class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Class prices, component prices, and advanced pricing factors. 1005.50 Section 1005.50 Agriculture Regulations of the Department of Agriculture (Continued..., and advanced pricing factors. See § 1000.50. ...

7 CFR 1001.50 - Class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Class prices, component prices, and advanced pricing factors. 1001.50 Section 1001.50 Agriculture Regulations of the Department of Agriculture (Continued..., and advanced pricing factors. See § 1000.50. ...

7 CFR 1006.50 - Class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Class prices, component prices, and advanced pricing factors. 1006.50 Section 1006.50 Agriculture Regulations of the Department of Agriculture (Continued..., and advanced pricing factors. See § 1000.50. ...

7 CFR 1126.50 - Class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Class prices, component prices, and advanced pricing factors. 1126.50 Section 1126.50 Agriculture Regulations of the Department of Agriculture (Continued..., and advanced pricing factors. See § 1000.50. ...

7 CFR 1032.50 - Class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Class prices, component prices, and advanced pricing factors. 1032.50 Section 1032.50 Agriculture Regulations of the Department of Agriculture (Continued..., and advanced pricing factors. See § 1000.50. ...

7 CFR 1131.50 - Class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Class prices, component prices, and advanced pricing factors. 1131.50 Section 1131.50 Agriculture Regulations of the Department of Agriculture (Continued..., and advanced pricing factors. See § 1000.50. ...

7 CFR 1007.50 - Class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Class prices, component prices, and advanced pricing factors. 1007.50 Section 1007.50 Agriculture Regulations of the Department of Agriculture (Continued..., and advanced pricing factors. See § 1000.50. ...

7 CFR 1124.53 - Announcement of class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Announcement of class prices, component prices, and advanced pricing factors. 1124.53 Section 1124.53 Agriculture Regulations of the Department of Agriculture... Announcement of class prices, component prices, and advanced pricing factors. See § 1000.53. ...

Nutcracker Syndrome Accompanying Pelvic Congestion Syndrome; Color Doppler Sonography and Multislice CT Findings: A Case Report

International Nuclear Information System (INIS)

Inal, Mikail; Karadeniz Bilgili, Mihrace Yasemin; Sahin, Safa

2014-01-01

Nutcracker syndrome (NCS) is a rare pathology, caused by compression of the left renal vein (LRV) between the abdominal aorta (AA) and the superior mesenteric artery (SMA), due to reduction of the angle between AA and SMA. This leads to LRV varices, left gonadal vein varices and therefore, the pelvic congestion syndrome. For this reason, coexistence of NCS and pelvic congestion syndrome has been described. It manifests by hematuria, proteinuria, and nonspecific pelvic pain secondary to pelvic congestion, dyspareunia and persistent genital arousal. We report a 27-year-old woman who experienced hematuria and left flank pain. The diagnosis of NCS accompanied by pelvic congestion syndrome was missed initially, but later on the diagnosis was made by color Doppler ultrasound, abdominal computed tomography (CT) and CT angiography that were later performed. She refused interventional and surgical treatments, and was lost to follow up

Crystal structures of three sterically congested disilanes

Directory of Open Access Journals (Sweden)

Kothanda Rama Pichaandi

2017-03-01

Full Text Available In the three sterically congested silanes, C24H38Si2 (1 (1,1,2,2-tetraisopropyl-1,2-diphenyldisilane, C24H34Br4Si2 (2 [1,1,2,2-tetrakis(2-bromopropan-2-yl-1,2-diphenyldisilane] and C32H38Si2 (3 (1,2-di-tert-butyl-1,1,2,2-tetraphenyldisilane, the Si—Si bond length is shortest in (1 and longest in (2, with (3 having an intermediate value, which parallels the increasing steric congestion. A comparison of the two isopropyl derivatives, (1 and 2, shows a significant increase in the Si—C(ipso distance with the introduction of bromine. Also, in the brominated compound 2, attractive intermolecular Br...Br interactions exist with Br...Br separations ca 0.52 Å shorter than the sum of the van der Waals radii. In compound 2, one of the bromoisopropyl groups is rotationally disordered in an 0.8812 (9:0.1188 (9 ratio. Compound 3 exhibits `whole molecule' disorder in a 0.9645 (7:0.0355 (7 ratio with the Si—Si bonds in the two components making an angle of ca 66°.

Improving UDP/IP Transmission Without Increasing Congestion

Science.gov (United States)

Burleigh, Scott

2006-01-01

Datagram Retransmission (DGR) is a computer program that, within certain limits, ensures the reception of each datagram transmitted under the User Datagram Protocol/Internet Protocol. [User Datagram Protocol (UDP) is considered unreliable because it does not involve a reliability-ensuring connection-initiation dialogue between sender and receiver. UDP is well suited to issuing of many small messages to many different receivers.] Unlike prior software for ensuring reception of UDP datagrams, DGR does not contribute to network congestion by retransmitting data more frequently as an ever-increasing number of messages and acknowledgements is lost. Instead, DGR does just the opposite: DGR includes an adaptive timeout-interval- computing component that provides maximum opportunity for reception of acknowledgements, minimizing retransmission. By monitoring changes in the rate at which message-transmission transactions are completed, DGR detects changes in the level of congestion and responds by imposing varying degrees of delay on the transmission of new messages. In addition, DGR maximizes throughput by not waiting for acknowledgement of a message before sending the next message. All DGR communication is asynchronous, to maximize efficient utilization of network connections. DGR manages multiple concurrent datagram transmission and acknowledgement conversations.

Edgeworth Price Cycles, Cost-Based Pricing, and Sticky Pricing in Retail Gasoline Markets

OpenAIRE

Michael D. Noel

2007-01-01

This paper examines dynamic pricing behavior in retail gasoline markets for 19 Canadian cities over 574 weeks. I find three distinct retail pricing patterns: 1. cost-based pricing, 2. sticky pricing, and 3. steep, asymmetric retail price cycles that, while seldom documented empirically, resemble those of Maskin & Tirole[1988]. Using a Markov switching regression, I estimate the prevalence of patterns and the structural characteristics of the cycles. Retail price cycles prevail in over 40% of ...

Competitive Pricing by a Price Leader

OpenAIRE

Abhik Roy; Dominique M. Hanssens; Jagmohan S. Raju

1994-01-01

We examine the problem of pricing in a market where one brand acts as a price leader. We develop a procedure to estimate a leader's price rule, which is optimal given a sales target objective, and allows for the inclusion of demand forecasts. We illustrate our estimation procedure by calibrating this optimal price rule for both the leader and the follower using data on past sales and prices from the mid-size sedan segment of the U.S. automobile market. Our results suggest that a leader-follow...

14 CFR 105.21 - Parachute operations over or into a congested area or an open-air assembly of persons.

Science.gov (United States)

2010-01-01

... congested area or an open-air assembly of persons. 105.21 Section 105.21 Aeronautics and Space FEDERAL... congested area of a city, town, or settlement, or an open-air assembly of persons unless a certificate of... over a congested area or an open-air assembly of persons with a fully deployed and properly functioning...

Extension of market concept with market-driven optimisation of distribution system operation

DEFF Research Database (Denmark)

Wu, Qiuwei; Østergaard, Jacob

2013-01-01

not explicitly submitted, but derived from historic demand response behaviour. The locational prices resulting from this local optimisation were used to alleviate the congestion that would result from response to a global price, as issued within the EcoGrid EU real time market for system balancing services from......This report describes the development of a pricing mechanism for the alleviation of congestion at the 10kV distribution network level using demand flexibility in a 5-minute real-time market environment. Demand was incorporated into an OPF based market clearing procedure in which demand bids were...... distributed resources. A complementary direct control framework was developed to operate in tandem with the pricing mechanism to ensure the reliable alleviation of congestion...

List prices vs. bargain prices: which solution to estimate consumer price indices?

OpenAIRE

Carlo De Gregorio

2010-01-01

Alternative approaches to CPI surveys are here evaluated, in markets where final prices are based on some sort of price listing. Three types of surveys are compared: local surveys (LOC), with small samples and a local price collection; list price surveys (LIS), with huge samples and centralised collection; mixed surveys (MXD), in which LOC and LIS are jointly used. Based on a multiplicative pricing model, some conditions are derived to establish the relative efficiency of these approaches. Th...

Variables associated with lung congestion as assessed by chest ultrasound in diabetics undergoing hemodialysis

Directory of Open Access Journals (Sweden)

Paulo Roberto Santos

Full Text Available Abstract Introduction: Ultrasound is an emerging method for assessing lung congestion but is still seldom used. Lung congestion is an important risk of cardiac events and death in end-stage renal disease (ESRD patients on hemodialysis (HD. Objective: We investigated possible variables associated with lung congestion among diabetics with ESRD on HD, using chest ultrasound to detect extracellular lung water. Methods: We studied 73 patients with diabetes as the primary cause of ESRD, undergoing regular HD. Lung congestion was assessed by counting the number of B lines detected by chest ultrasound. Hydration status was assessed by bioimpedance analysis and cardiac function by echocardiography. The collapse index of the inferior vena cava (IVC was measured by ultrasonography. All patients were classified according to NYHA score. Correlations of the number of B lines with continuous variables and comparisons regarding the number of B lines according to categorical variables were performed. Multivariate linear regression was used to test the variables as independent predictors of the number of B lines. Results: None of the variables related to hydration status and cardiac function were associated with the number of B lines. In the multivariate analysis, only the IVC collapse index (b = 45.038; p < 0.001 and NYHA classes (b = 13.995; p = 0.006 were independent predictors of the number of B lines. Conclusion: Clinical evaluation based on NYHA score and measurement of the collapsed IVC index were found to be more reliable than bioimpedance analysis to predict lung congestion.

A Novel Congestion Detection Scheme in TCP Over OBS Networks

KAUST Repository

Shihada, Basem; Ho, Pin-Han; Zhang, Qiong

2009-01-01

This paper introduces a novel congestion detection scheme for high-bandwidth TCP flows over optical burst switching (OBS) networks, called statistical additive increase multiplicative decrease (SAIMD). SAIMD maintains and analyzes a number

A combined fair decentralized message-rate and data-rate congestion control for V2V communication

NARCIS (Netherlands)

Belagal Math, Chetan; Li, Hong; De Groot, Sonia Heemstra; Niemegeers, Ignas

2018-01-01

Channel congestion Is one of the most critical Issues In IEEE 802.11p-based vehicular ad hoc networks as it leads to unreliability of safety applications. As a counter measure, the European Telecommunications Standard Institute (ETSI), proposes a mandatory Decentralized Congestion Control (DCC)

Arbitrage Pricing, Capital Asset Pricing, and Agricultural Assets

OpenAIRE

Louise M. Arthur; Colin A. Carter; Fay Abizadeh

1988-01-01

A new asset pricing model, the arbitrage pricing theory, has been developed as an alternative to the capital asset pricing model. The arbitrage pricing theory model is used to analyze the relationship between risk and return for agricultural assets. The major conclusion is that the arbitrage pricing theory results support previous capital asset pricing model findings that the estimated risk associated with agricultural assets is low. This conclusion is more robust for the arbitrage pricing th...

Output Price Risk, Material Input Price Risk, and Price Margins: Evidence from the US Catfish Industry.

Directory of Open Access Journals (Sweden)

David Bouras

2017-07-01

Full Text Available Aim/purpose - To develop a conceptual model for analyzing the impact of output price risk and material input price risk on price margins. Design/methodology/approach - To analyze the combined effect of output price risk and material input risk on price margins, we use a series of comparative static analyses, GARCH models, and data ranging from 1990/01 to 2012/12. Findings - The theoretical results indicate that the impact of output price risk and the impact of material input price risk on price margins are ambiguous and, to a great extent, hinge on the correlation between output price and material input price. The empirical results show that whole frozen catfish price risk and live catfish price risk negatively affect the price margin for frozen catfish. The empirical results, however, indicate that the risk of the price of live catfish affects markedly the price margin for frozen whole catfish in contrast to the impact of the risk of the price of frozen whole catfish. Research implications/limitations - The empirical results have significant implications for managerial decision-making especially when crafting strategies for improving price margins. Accordingly, in order to beef up the price margin for frozen whole catfish, catfish processors may consider engaging in vertical integration. This paper has some limitations: first, it assumes that firms operate in competitive markets; second, it assumes that firms produce and sell a single product. Originality/value/contribution - Unlike earlier studies that focused solely on the effect of output price risk on price margins, this paper analyzes theoretically and empirically the impact of output price risk and material input price risk on price margins.

Correlation of radiological assessment of congestive heart failure with left ventricular end-diastolic pressure

International Nuclear Information System (INIS)

Herman, P.G.; Kahn, A.; Kallman, C.E.; Rojas, K.A.; Bodenheimer, M.M.

1988-01-01

Left ventricular end-diastolic pressure (LVEDP) has been considered a reliable indicator of left ventricular function. The purpose of this study was to correlate the radiologic assessment of congestive heart failure with LVEDP. The population of the study consisted of 85 consecutive cases in four ranges of LVEDP ( 24). The PA chest radiographs obtained 1 day prior to cardiac catherization were assessed for radiological evidence of congestive heart failure and were graded from normal to abnormal (0-3). The results will be summarized in the authors' presentation. The discordance of radiological assessment of congestive heart failure in patients with elevated LVEDP will be discussed in light of recent advances in pathophysiologic understanding of left ventricular function and the impact of new classes of drugs in the management of these patients

Adaptive mechanism-based congestion control for networked systems

Science.gov (United States)

Liu, Zhi; Zhang, Yun; Chen, C. L. Philip

2013-03-01

In order to assure the communication quality in network systems with heavy traffic and limited bandwidth, a new ATRED (adaptive thresholds random early detection) congestion control algorithm is proposed for the congestion avoidance and resource management of network systems. Different to the traditional AQM (active queue management) algorithms, the control parameters of ATRED are not configured statically, but dynamically adjusted by the adaptive mechanism. By integrating with the adaptive strategy, ATRED alleviates the tuning difficulty of RED (random early detection) and shows a better control on the queue management, and achieve a more robust performance than RED under varying network conditions. Furthermore, a dynamic transmission control protocol-AQM control system using ATRED controller is introduced for the systematic analysis. It is proved that the stability of the network system can be guaranteed when the adaptive mechanism is finely designed. Simulation studies show the proposed ATRED algorithm achieves a good performance in varying network environments, which is superior to the RED and Gentle-RED algorithm, and providing more reliable service under varying network conditions.

Smart curtailment for congestion management in LV distribution network

NARCIS (Netherlands)

Haque, A. N.M.M.; Rahman, M. T.; Nguyen, P. H.; Bliek, F. W.

2016-01-01

The rapid proliferation of distributed energy resources (DERs) leads to capacity challenges, i.e. network congestions, in the low-voltage (LV) distribution networks. A number of strategies are being widely studied to tackle the challenges with direct switching actions such as load shedding or power

7 CFR 1000.53 - Announcement of class prices, component prices, and advanced pricing factors.

Science.gov (United States)

2010-01-01

... advanced pricing factors. 1000.53 Section 1000.53 Agriculture Regulations of the Department of Agriculture..., component prices, and advanced pricing factors. (a) On or before the 5th day of the month, the market... administrator for each Federal milk marketing order shall announce the following prices and pricing factors for...

Mathematic Modeling and Performance Analysis of an Adaptive Congestion Control in Intelligent Transportation Systems

OpenAIRE

Naja, Rola; Université de Versailles

2015-01-01

In this paper, we develop a preventive congestion control mechanism applied at highway entrances and devised for Intelligent Transportation Systems (ITS). The proposed mechanism provides a vehicular admission control, regulates input traffic and performs vehicular traffic shaping. Our congestion control mechanism includes two classes of vehicles and is based on a specific priority ticket pool scheme with queue-length threshold scheduling policy, tailored to vehicular networks. In an attempt t...

Estimating teat canal cross-sectional area to determine the effects of teat-end and mouthpiece chamber vacuum on teat congestion.

Science.gov (United States)

Penry, J F; Upton, J; Mein, G A; Rasmussen, M D; Ohnstad, I; Thompson, P D; Reinemann, D J

2017-01-01

The primary objective of this experiment was to assess the effect of mouthpiece chamber vacuum on teat-end congestion. The secondary objective was to assess the interactive effects of mouthpiece chamber vacuum with teat-end vacuum and pulsation setting on teat-end congestion. The influence of system vacuum, pulsation settings, mouthpiece chamber vacuum, and teat-end vacuum on teat-end congestion were tested in a 2×2 factorial design. The low-risk conditions for teat-end congestion (TEL) were 40 kPa system vacuum (Vs) and 400-ms pulsation b-phase. The high-risk conditions for teat-end congestion (TEH) were 49 kPa Vs and 700-ms b-phase. The low-risk condition for teat-barrel congestion (TBL) was created by venting the liner mouthpiece chamber to atmosphere. In the high-risk condition for teat-barrel congestion (TBH) the mouthpiece chamber was connected to short milk tube vacuum. Eight cows (32 quarters) were used in the experiment conducted during 0400 h milkings. All cows received all treatments over the entire experimental period. Teatcups were removed after 150 s for all treatments to standardize the exposure period. Calculated teat canal cross-sectional area (CA) was used to assess congestion of teat tissue. The main effect of the teat-end treatment was a reduction in CA of 9.9% between TEL and TEH conditions, for both levels of teat-barrel congestion risk. The main effect of the teat-barrel treatment was remarkably similar, with a decrease of 9.7% in CA between TBL and TBH conditions for both levels of teat-end congestion risk. No interaction between treatments was detected, hence the main effects are additive. The most aggressive of the 4 treatment combinations (TEH plus TBH) had a CA estimate 20% smaller than for the most gentle treatment combination (TEL plus TBL). The conditions designed to impair circulation in the teat barrel also had a deleterious effect on circulation at the teat end. This experiment highlights the importance of elevated mouthpiece

Ex-vessel Fish Price Database: Disaggregating Prices for Low-Priced Species from Reduction Fisheries

Directory of Open Access Journals (Sweden)

Travis C. Tai

2017-11-01

Full Text Available Ex-vessel fish prices are essential for comprehensive fisheries management and socioeconomic analyses for fisheries science. In this paper, we reconstructed a global ex-vessel price database with the following areas of improvement: (1 compiling reported prices explicitly listed as “for reduction to fishmeal and fish oil” to estimate prices separately for catches destined for fishmeal and fish oil production, and other non-direct human consumption purposes; (2 including 95% confidence limit estimates for each price estimation; and (3 increasing the number of input data and the number of price estimates to match the reconstructed Sea Around Us catch database. Our primary focus was to address this first area of improvement as ex-vessel prices for catches destined for non-direct human consumption purposes were substantially overestimated, notably in countries with large reduction fisheries. For example in Peru, 2010 landed values were estimated as 3.8 billion real 2010 USD when using separate prices for reduction fisheries, compared with 5.8 billion using previous methods with only one price for all end-products. This update of the price database has significant global and country-specific impacts on fisheries price and landed value trends over time.

Urban Partnership Agreement and Congestion Reduction Demonstration : National Evaluation Framework

Science.gov (United States)

2008-11-21

This report provides an analytical framework for evaluating six deployments under the United States Department of Transportation (U.S. DOT) Urban Partnership Agreement (UPA) and Congestion Reduction Demonstration (CRD) Programs. The six UPA/CRD sites...

Medicinal Leech Therapy for Glans Penis Congestion After Primary Bladder Exstrophy-Epispadias Repair in an Infant: A Case Report.

Science.gov (United States)

Wagenheim, Gavin N; Au, Jason; Gargollo, Patricio C

2016-01-01

Many postoperative complications have been reported after repair of classic bladder exstrophy. We present a case of medicinal leech therapy for glans penis congestion following exstrophy repair in an infant. A 2-week-old male with classic bladder exstrophy underwent complete primary repair. On postoperative day 1, he developed rapidly worsening glans penis venous congestion. Medicinal leech therapy was instituted with antibiotics and blood transfusions to maintain a hematocrit >30%. After 24 hours, venous congestion improved and therapy was discontinued. The patient's remaining hospital course was uncomplicated. Medicinal leeches are an effective therapy to relieve glans penis venous congestion. Copyright © 2015 Elsevier Inc. All rights reserved.

Indirect Damage of Urban Flooding: Investigation of Flood-Induced Traffic Congestion Using Dynamic Modeling

Directory of Open Access Journals (Sweden)

Jingxuan Zhu

2018-05-01

Full Text Available In many countries, industrialization has led to rapid urbanization. Increased frequency of urban flooding is one consequence of the expansion of urban areas which can seriously affect the productivity and livelihoods of urban residents. Therefore, it is of vital importance to study the effects of rainfall and urban flooding on traffic congestion and driver behavior. In this study, a comprehensive method to analyze the influence of urban flooding on traffic congestion was developed. First, a flood simulation was conducted to predict the spatiotemporal distribution of flooding based on Storm Water Management Model (SWMM and TELAMAC-2D. Second, an agent-based model (ABM was used to simulate driver behavior during a period of urban flooding, and a car-following model was established. Finally, in order to study the mechanisms behind how urban flooding affects traffic congestion, the impact of flooding on urban traffic was investigated based on a case study of the urban area of Lishui, China, covering an area of 4.4 km2. It was found that for most events, two-hour rainfall has a certain impact on traffic congestion over a five-hour period, with the greatest impact during the hour following the cessation of the rain. Furthermore, the effects of rainfall with 10- and 20-year return periods were found to be similar and small, whereas the effects with a 50-year return period were obvious. Based on a combined analysis of hydrology and transportation, the proposed methods and conclusions could help to reduce traffic congestion during flood seasons, to facilitate early warning and risk management of urban flooding, and to assist users in making informed decisions regarding travel.

Clinical outcome of ovarian vein embolization in pelvic congestion ...

African Journals Online (AJOL)

Introduction: Pelvic congestion syndrome (PCS), is a condition associated with ovarian vein (OV) incompetence among other causes. It is manifested by chronic pelvic pain with associated dyspareunia and dysmenorrhea. The diagnosis of PCS is often overlooked and the management can be difficult. Traditional therapy for ...

Mendenhall Glacier Visitor Center vehicular and pedestrian traffic congestion study

Science.gov (United States)

2007-05-01

The Mendenhall Glacier Visitor Center of Tongass National Forest in Juneau, Alaska is experiencing vehicular and pedestrian congestion. This study was initiated by the United States Forest Service, Alaska Region, in cooperation with Western Federal L...

Price strategy and pricing strategy: terms and content identification

OpenAIRE

Panasenko Tetyana

2015-01-01

The article is devoted to the terminology and content identification of seemingly identical concepts "price strategy" and "pricing strategy". The article contains evidence that the price strategy determines the direction, principles and procedure of implementing the company price policy and pricing strategy creates a set of rules and practical methods of price formation in accordance with the pricing strategy of the company.

Real Driving Emissions in Congested Traffic: A Comparison of Cold and Hot Start

OpenAIRE

Khalfan, A; Andrews, GE; Li, H

2016-01-01

Air quality NO₂ and PM exceedances in cities are common, where congested traffic occurs and the monitoring station is at the roadside. This work investigated real world emissions for a Euro 4 SI vehicle on a congested road by a roadside air quality monitoring station that exceeds European air quality standards for NOx and PM. The PEMS used was the Temet FTIR with Horiba OBS pitot tube exhaust mass flow sensor and gas sampler. Twenty nine hot start repeat journeys were made at different times ...

The effect of counter-trading on competition in electricity markets

International Nuclear Information System (INIS)

Dijk, Justin; Willems, Bert

2011-01-01

In a competitive electricity market, nodal pricing is the most efficient way to manage congestion. Counter-trading is inefficient as it gives the wrong long term signals for entry and exit of power plants. However, in a non-competitive market, additional entry will improve the competitiveness of the market, and will increase social benefit by reducing price-cost margins. This paper studies whether the potential pro-competitive entry effects could make counter-trading more efficient than nodal pricing. We find that this is unlikely to be the case, and expect counter-trading to have a negative effect on overall welfare. The potential benefits of additional competition (more competitive prices and lower production cost) do not outweigh the distortions (additional investment cost for the entrant, and socialization of the congestion cost to final consumers). - Research highlights: → 'Counter-trading' and 'nodal pricing' manage congestion in electric grids. → Nodal pricing gives superior locational prices. → Counter-trading induces extra investments in regions with a production surplus. → Extra investments improve competition, but are expected to be socially inefficient.

Value based pricing: the least valued pricing strategy

OpenAIRE

Hoenen, Bob

2017-01-01

Pricing has been one of the least researched topics in marketing, although within these pricing strategies: cost-plus pricing is considered as the leading pricing strategy worldwide. Why should companies use such an unprofitable strategy, where fighting for a higher market share due to low prices is more a rule than exception? VBP is one of the most underestimated strategies by organizations. The definition of VBP is: 'value pricing applies to products that have the potential of being differe...

48 CFR 36.207 - Pricing fixed-price construction contracts.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Pricing fixed-price... Contracting for Construction 36.207 Pricing fixed-price construction contracts. (a) Generally, firm-fixed... methods. (b) Lump-sum pricing shall be used in preference to unit pricing except when— (1) Large...

Price strategy and pricing strategy: terms and content identification

Directory of Open Access Journals (Sweden)

Panasenko Tetyana

2015-11-01

Full Text Available The article is devoted to the terminology and content identification of seemingly identical concepts "price strategy" and "pricing strategy". The article contains evidence that the price strategy determines the direction, principles and procedure of implementing the company price policy and pricing strategy creates a set of rules and practical methods of price formation in accordance with the pricing strategy of the company.

Logistics: Price Rises Incurred by High Oil Price

Institute of Scientific and Technical Information of China (English)

Lai Zhihui

2011-01-01

@@ "When the oil price grows by 100%, the logistic indus-try will see a price growth of 40%, while the logistics in-dustry a price rise of 35%, which means every price increase of 5% in the oil price will bring along that of 2% in this industry." said Liu Zongsheng, General Manager of Itochu Logistics Co., Ltd., on the seminar "Focusing on the eco-nomic consequences of raising oil price, interest rate and deposit reserve ratio", which was held recently.

When the heart kills the liver: acute liver failure in congestive heart failure

Directory of Open Access Journals (Sweden)

Saner FH

2009-12-01

Full Text Available Abstract Congestive heart failure as a cause of acute liver failure is rarely documented with only a few cases. Although the pathophysiology is poorly understood, there is rising evidence, that low cardiac output with consecutive reduction in hepatic blood flow is a main causing factor, rather than hypotension. In the setting of acute liver failure due to congestive heart failure, clinical signs of the latter can be absent, which requires an appropriate diagnostic approach. As a reference center for acute liver failure and liver transplantation we recorded from May 2003 to December 2007 202 admissions with the primary diagnoses acute liver failure. 13/202 was due to congestive heart failure, which was associated with a mortality rate of 54%. Leading cause of death was the underlying heart failure. Asparagine transaminase (AST, bilirubin, and international normalized ratio (INR did not differ significantly in surviving and deceased patients at admission. Despite both groups had signs of cardiogenic shock, the cardiac index (CI was significantly higher in the survival group on admission as compared with non-survivors (2.1 L/min/m2 vs. 1.6 L/min/m2, p = 0.04. Central venous - and pulmonary wedge pressure did not differ significantly. Remarkable improvement of liver function was recorded in the group, who recovered from cardiogenic shock. In conclusion, patients with acute liver failure require an appropriate diagnostic approach. Congestive heart failure should always be considered as a possible cause of acute liver failure.

Enhancing medicine price transparency through price information mechanisms.

Science.gov (United States)

Hinsch, Michael; Kaddar, Miloud; Schmitt, Sarah

2014-05-08

Medicine price information mechanisms provide an essential tool to countries that seek a better understanding of product availability, market prices and price compositions of individual medicines. To be effective and contribute to cost savings, these mechanisms need to consider prices in their particular contexts when comparing between countries. This article discusses in what ways medicine price information mechanisms can contribute to increased price transparency and how this may affect access to medicines for developing countries. We used data collected during the course of a WHO project focusing on the development of a vaccine price and procurement information mechanism. The project collected information from six medicine price information mechanisms and interviewed data managers and technical experts on key aspects as well as observed market effects of these mechanisms.The reviewed mechanisms were broken down into categories including objective and target audience, as well as the sources, types and volumes of data included. Information provided by the mechanisms was reviewed according to data available on medicine prices, product characteristics, and procurement modalities. We found indications of positive effects on access to medicines resulting from the utilization of the reviewed mechanisms. These include the uptake of higher quality medicines, more favorable results from contract negotiations, changes in national pricing policies, and the decrease of prices in certain segments for countries participating in or deriving data from the various mechanisms. The reviewed mechanisms avoid the methodological challenges observed for medicine price comparisons that only use national price databases. They work with high quality data and display prices in the appropriate context of procurement modalities as well as the peculiarities of purchasing countries. Medicine price information mechanisms respond to the need for increased medicine price transparency and have the

Dynamic Pricing

DEFF Research Database (Denmark)

Sharifi, Reza; Anvari-Moghaddam, Amjad; Fathi, S. Hamid

2017-01-01

Dynamic pricing scheme, also known as real-time pricing (RTP), can be more efficient and technically beneficial than the other price-based schemes (such as flat-rate or time-of-use (TOU) pricing) for enabling demand response (DR) actions. Over the past few years, advantages of RTP-based schemes h...... of dynamic pricing can lead to increased willingness of consumers to participate in DR programs which in turn improve the operation of liberalized electricity markets.......Dynamic pricing scheme, also known as real-time pricing (RTP), can be more efficient and technically beneficial than the other price-based schemes (such as flat-rate or time-of-use (TOU) pricing) for enabling demand response (DR) actions. Over the past few years, advantages of RTP-based schemes...

Factors associated with health-related quality of life in stable ambulatory congestive heart failure patients: Systematic review.

Science.gov (United States)

Baert, Anneleen; De Smedt, Delphine; De Sutter, Johan; De Bacquer, Dirk; Puddu, Paolo Emilio; Clays, Els; Pardaens, Sofie

2018-03-01

Background Since improved treatment of congestive heart failure has resulted in decreased mortality and hospitalisation rates, increasing self-perceived health-related quality of life (HRQoL) has become a major goal of congestive heart failure treatment. However, an overview on predictieve factors of HRQoL is currently lacking in literature. Purpose The aim of this study was to identify key factors associated with HRQoL in stable ambulatory patients with congestive heart failure. Methods A systematic review was performed. MEDLINE, Web of Science and Embase were searched for the following combination of terms: heart failure, quality of life, health perception or functional status between the period 2000 and February 2017. Literature screening was done by two independent reviewers. Results Thirty-five studies out of 8374 titles were included for quality appraisal, of which 29 were selected for further data extraction. Four distinct categories grouping different types of variables were identified: socio-demographic characteristics, clinical characteristics, health and health behaviour, and care provider characteristics. Within the above-mentioned categories the presence of depressive symptoms was most consistently related to a worse HRQoL, followed by a higher New York Heart Association functional class, younger age and female gender. Conclusion Through a systematic literature search, factors associated with HRQoL among congestive heart failure patients were investigated. Age, gender, New York Heart Association functional class and depressive symptoms are the most consistent variables explaining the variance in HRQoL in patients with congestive heart failure. These findings are partly in line with previous research on predictors for hard endpoints in patients with congestive heart failure.

Route Monopolie and Optimal Nonlinear Pricing

Science.gov (United States)

Tournut, Jacques

2003-01-01

To cope with air traffic growth and congested airports, two solutions are apparent on the supply side: 1) use larger aircraft in the hub and spoke system; or 2) develop new routes through secondary airports. An enlarged route system through secondary airports may increase the proportion of route monopolies in the air transport market.The monopoly optimal non linear pricing policy is well known in the case of one dimension (one instrument, one characteristic) but not in the case of several dimensions. This paper explores the robustness of the one dimensional screening model with respect to increasing the number of instruments and the number of characteristics. The objective of this paper is then to link and fill the gap in both literatures. One of the merits of the screening model has been to show that a great varieD" of economic questions (non linear pricing, product line choice, auction design, income taxation, regulation...) could be handled within the same framework.VCe study a case of non linear pricing (2 instruments (2 routes on which the airline pro_ddes customers with services), 2 characteristics (demand of services on these routes) and two values per characteristic (low and high demand of services on these routes)) and we show that none of the conclusions of the one dimensional analysis remain valid. In particular, upward incentive compatibility constraint may be binding at the optimum. As a consequence, they may be distortion at the top of the distribution. In addition to this, we show that the optimal solution often requires a kind of form of bundling, we explain explicitly distortions and show that it is sometimes optimal for the monopolist to only produce one good (instead of two) or to exclude some buyers from the market. Actually, this means that the monopolist cannot fully apply his monopoly power and is better off selling both goods independently.We then define all the possible solutions in the case of a quadratic cost function for a uniform

(GIS-T) application for traffic congestion analyses in the De

African Journals Online (AJOL)

generation known as the 'traditional stopwatch and traffic congestion registration ... transportation safety analysis, travel demand analysis, traffic monitoring and .... many transportation agencies use distance measuring instruments (DMIs) in their probe vehicles. ..... Spatial Implications of the Tuberculosis DOTS Strategy in.

Congestion management rules and trading strategies in the Spanish electricity market

Energy Technology Data Exchange (ETDEWEB)

Furio, Dolores; Lucia, Julio J. [Departamento de Economia Financiera y Actuarial, Universidad de Valencia, Avda. Los Naranjos, s/n, 46022 - Valencia (Spain)

2009-01-15

This paper analyses the economic incentives embodied in the rules governing the resolution of transmission constraints in the Spanish wholesale electricity market and the way these incentives may have influenced on the trading behaviour of both the generators and the demand side. The evidence obtained is consistent with them responding to these incentives. In particular, buyers would respond to the way congestion costs are billed to them by abandoning the daily market in favour of the intraday market as far as possible. Additionally, some strategic generators may have been prompted the system operator to require them to inject electricity into the system to solve network congestions. Finally, these results may contribute to shed light on what should be expected of the reform in the aforementioned rules. (author)

Congestion management rules and trading strategies in the Spanish electricity market

International Nuclear Information System (INIS)

Furio, Dolores; Lucia, Julio J.

2009-01-01

This paper analyses the economic incentives embodied in the rules governing the resolution of transmission constraints in the Spanish wholesale electricity market and the way these incentives may have influenced on the trading behaviour of both the generators and the demand side. The evidence obtained is consistent with them responding to these incentives. In particular, buyers would respond to the way congestion costs are billed to them by abandoning the daily market in favour of the intraday market as far as possible. Additionally, some strategic generators may have been prompted the system operator to require them to inject electricity into the system to solve network congestions. Finally, these results may contribute to shed light on what should be expected of the reform in the aforementioned rules. (author)

Determinants of Traffic Congestion in the Metropolis of Douala ...

African Journals Online (AJOL)

On the other hand, urban agglomeration used as a proxy for traffic congestion has a negative effect on urban growth and economic growth. Based on the above results, it is recommended that a remedial infrastructural development plan and a sustainable polycentric land use pattern with alternative efficient mode of public ...

ACCOUNTING ASPECTS OF PRICING AND TRANSFER PRICING

Directory of Open Access Journals (Sweden)

TÜNDE VERES

2011-01-01

Full Text Available The pricing methods in practice need really complex view of the business situation and depend on the strategy and market position of a company. The structure of a price seems simple: cost plus margin. Both categories are special area in the management accounting. Information about the product costs, the allocation methodologies in cost accounting, the analyzing of revenue and different level of the margin needs information from accounting system. This paper analyzes the pricing methods from management accounting aspects to show out the role of the accounting system in the short term and long term pricing and transfer pricing decisions.

Visceral Congestion in Heart Failure: Right Ventricular Dysfunction, Splanchnic Hemodynamics, and the Intestinal Microenvironment.

Science.gov (United States)

Polsinelli, Vincenzo B; Sinha, Arjun; Shah, Sanjiv J

2017-12-01

Visceral venous congestion of the gut may play a key role in the pathogenesis of right-sided heart failure (HF) and cardiorenal syndromes. Here, we review the role of right ventricular (RV) dysfunction, visceral congestion, splanchnic hemodynamics, and the intestinal microenvironment in the setting of right-sided HF. We review recent literature on this topic, outline possible mechanisms of disease pathogenesis, and discuss potential therapeutics. There are several mechanisms linking RV-gut interactions via visceral venous congestion which could result in (1) hypoxia and acidosis in enterocytes, which may lead to enhanced sodium-hydrogen exchanger 3 (NHE3) expression with increased sodium and fluid retention; (2) decreased luminal pH in the intestines, which could lead to alteration of the gut microbiome which could increase gut permeability and inflammation; (3) alteration of renal hemodynamics with triggering of the cardiorenal syndrome; and (4) altered phosphate metabolism resulting in increased pulmonary artery stiffening, thereby increasing RV afterload. A wide variety of therapeutic interventions that act on the RV, pulmonary vasculature, intestinal microenvironment, and the kidney could alter these pathways and should be tested in patients with right-sided HF. The RV-gut axis is an important aspect of HF pathogenesis that deserves more attention. Modulation of the pathways interconnecting the right heart, visceral congestion, and the intestinal microenvironment could be a novel avenue of intervention for right-sided HF.

Network-based model for predicting the effect of fuel price on transit ridership and greenhouse gas emissions

Directory of Open Access Journals (Sweden)

Michael W. Levin

2017-12-01

Full Text Available As fuel prices increase, drivers may make travel choices to minimize not only travel time, but also fuel consumption. Consideration of fuel consumption would affect route choice and influence trip frequency and mode choice. For instance, travelers may elect to live closer to their workplace, or use public transit to avoid fuel consumption and the associated costs. To incorporate network characteristics into predictions of the effects of fuel prices, we develop a multi-class combined elastic demand, mode choice, and user equilibrium model using a generalized cost function of travel time and fuel consumption with a combined solution algorithm. The algorithm is implemented in a custom software package, and a case study application on the Austin, Texas network is presented. We evaluate the fuel-price sensitivity of key variables such as drive-alone and transit class proportions, person-miles traveled, link-level traffic flow and per capita fuel consumption and emissions. These effects are examined across a heterogeneous demand set, with multiple user-classes categorized based on their value of travel time. The highest relative transit elasticities against fuel price are observed among low value of time classes, as expected. Although total personal vehicle travel decreases, congestion increases on some roads due to the generalized cost function. Reductions in system-wide fuel consumption and greenhouse gas emissions are observed as well. The study uncovers the combined interactions among fuel prices, multi-modal choice behavior, travel performance, and resultant environmental impacts, all of which dictate the urban travel market. It also equips agencies with motivation to tailor emissions reduction and transit-ridership stimulus policies around the most responsive user classes.

Modeling and analyzing cascading dynamics of the Internet based on local congestion information

Science.gov (United States)

Zhu, Qian; Nie, Jianlong; Zhu, Zhiliang; Yu, Hai; Xue, Yang

2018-06-01

Cascading failure has already become one of the vital issues in network science. By considering realistic network operational settings, we propose the congestion function to represent the congested extent of node and construct a local congestion-aware routing strategy with a tunable parameter. We investigate the cascading failures on the Internet triggered by deliberate attacks. Simulation results show that the tunable parameter has an optimal value that makes the network achieve a maximum level of robustness. The robustness of the network has a positive correlation with tolerance parameter, but it has a negative correlation with the packets generation rate. In addition, there exists a threshold of the attacking proportion of nodes that makes the network achieve the lowest robustness. Moreover, by introducing the concept of time delay for information transmission on the Internet, we found that an increase of the time delay will decrease the robustness of the network rapidly. The findings of the paper will be useful for enhancing the robustness of the Internet in the future.

Oil price volatility and the asymmetric response of gasoline prices to oil price increases and decreases

International Nuclear Information System (INIS)

Radchenko, S.

2005-01-01

This paper analyzes the effect of volatility in oil prices on the degree of asymmetry in the response of gasoline prices to oil price increases and decreases. Several time series measures of the asymmetry between the responses of gasoline prices to oil price increases and decreases and several measures of the oil price volatility are constructed. In all models, the degree of asymmetry in gasoline prices declines with an increase in oil price volatility. The results support the oligopolistic coordination theory as a likely explanation of the observed asymmetry and are not consistent with the standard search theory and the search theory with Bayesian updating. (author)

Case of congestive heart failure induced by therapeutic irradiation

Energy Technology Data Exchange (ETDEWEB)

Kushigami, Motohiko; Suruda, Hidetoshi; Mizukoshi, Masato; Umemoto, Masaaki; Fujiwara, Setsuko; Yamamoto, Katsuhiro; Ueno, Yuji; Nishio, Ichiro; Masuyama, Yoshiaki

1985-02-01

Valvular insufficiency in radiation-induced heart disease is very rare. We described a patient, 53 years old woman, who developed congestive heart failure 2.5 years later following radiotherapy for esophageal carcinoma. The findings on examinations including cardiac catheterization revealed pericarditis with effusion, mitral and tricuspid valve insufficiency and pulmonary infarction. (author).

Finding social optima in congestion games with positive externalities

NARCIS (Netherlands)

de Keijzer, B.; Schäfer, G.

2012-01-01

We consider a variant of congestion games where every player i expresses for each resource e and player j a positive externality, i.e., a value for being on e together with player j. Rather than adopting a game-theoretic perspective, we take an optimization point of view and consider the problem of

Accessibility, Congestion and Travel Delays in Dar es Salaam

DEFF Research Database (Denmark)

Melbye, Dea Christine; Møller-Jensen, Lasse; Andreasen, Manja Hoppe

2015-01-01

on to present a review of research into travel speed levels and congestion in Dar es Salaam. A set of city-wide maps of accessibility and delay levels are constructed based on available speed data and road network data obtained from the OpenStreetMap project and the findings are discussed with respect...

Green supply chain: Simulating road traffic congestion

Science.gov (United States)

Jalal, Muhammad Zulqarnain Hakim Abd; Nawawi, Mohd Kamal Mohd; Laailatul Hanim Mat Desa, Wan; Khalid, Ruzelan; Khalid Abduljabbar, Waleed; Ramli, Razamin

2017-09-01

With the increasing awareness of the consumers about environmental issues, businesses, households and governments increasingly want use green products and services which lead to green supply chain. This paper discusses a simulation study of a selected road traffic system that will contribute to the air pollution if in the congestion state. Road traffic congestion (RTC) can be caused by a temporary obstruction, a permanent capacity bottleneck in the network itself, and stochastic fluctuation in demand within a particular sector of the network, leading to spillback and queue propagation. A discrete-event simulation model is developed to represent the real traffic light control (TLC) system condition during peak hours. Certain performance measures such as average waiting time and queue length were measured using the simulation model. Existing system uses pre-set cycle time to control the light changes which is fixed time cycle. In this research, we test several other combination of pre-set cycle time with the objective to find the best system. In addition, we plan to use a combination of the pre-set cycle time and a proximity sensor which have the authority to manipulate the cycle time of the lights. The sensors work in such situation when the street seems to have less occupied vehicles, obviously it may not need a normal cycle for green light, and automatically change the cycle to street where vehicle is present.

IS THE PRICE RIGHT? PRICING FOR LONG TERM PROFITABILITY

Directory of Open Access Journals (Sweden)

Andrea Erika NYÁRÁDI

2007-01-01

Full Text Available The way how we choose our pricing strategy has a significant impact on company’s success. Nowadays companies more and more adopt a new way of thinking in pricing, namely pricing for a long term period in order to bring higher profitability, to build an efficient pricing strategy. Marketers have only recently begun to focus seriously on effective pricing. These companies are the so called progressive companies. They have begun doing more than just worrying about pricing. To increase profitability many are abandoning traditional reactive pricing procedures in favor of proactive pricing, making explicit corporate decisions to change their focus to growth in top-line sales to growth in profitability. The long-term implications of price strategies are still under-researched, and managers should be aware of shifts in customer reactions that may result from frequent adoption of certain strategies. The company pricing strategy should be seen in relation to developments in the company variables, internal ones (capital strength, competencies, organizational conditions, efficiency of the work force etc. as well as external ones (customers, competitors, the technological development etc., adopting strategic pricing. In this paper I will present the most effective pricing strategies leading to long term profitability, and also suggest practical conditions for pricing strategies to maximize profit in the long run.

Patients' views on price shopping and price transparency.

Science.gov (United States)

Semigran, Hannah L; Gourevitch, Rebecca; Sinaiko, Anna D; Cowling, David; Mehrotra, Ateev

2017-06-01

Driven by the growth of high deductibles and price transparency initiatives, patients are being encouraged to search for prices before seeking care, yet few do so. To understand why this is the case, we interviewed individuals who were offered access to a widely used price transparency website through their employer. Qualitative interviews. We interviewed individuals enrolled in a preferred provider organization product through their health plan about their experience using the price transparency tool (if they had done so), their past medical experiences, and their opinions on shopping for care. All interviews were transcribed and manually coded using a thematic coding guide. In general, respondents expressed frustration with healthcare costs and had a positive opinion of the idea of price shopping in theory, but 2 sets of barriers limited their ability to do so in reality. The first was the salience of searching for price information. For example, respondents recognized that due to their health plan benefits design, they would not save money by switching to a lower-cost provider. Second, other factors were more important than price for respondents when choosing a provider, including quality and loyalty to current providers. We found a disconnect between respondents' enthusiasm for price shopping and their reported use of a price transparency tool to shop for care. However, many did find the tool useful for other purposes, including checking their claims history. Addressing the barriers to price shopping identified by respondents can help inform ongoing and future price transparency initiatives.

Road Traffic Congestion Management Based on a Search-Allocation Approach

Directory of Open Access Journals (Sweden)

Raiyn Jamal

2017-03-01

Full Text Available This paper introduces a new scheme for road traffic management in smart cities, aimed at reducing road traffic congestion. The scheme is based on a combination of searching, updating, and allocation techniques (SUA. An SUA approach is proposed to reduce the processing time for forecasting the conditions of all road sections in real-time, which is typically considerable and complex. It searches for the shortest route based on historical observations, then computes travel time forecasts based on vehicular location in real-time. Using updated information, which includes travel time forecasts and accident forecasts, the vehicle is allocated the appropriate section. The novelty of the SUA scheme lies in its updating of vehicles in every time to reduce traffic congestion. Furthermore, the SUA approach supports autonomy and management by self-regulation, which recommends its use in smart cities that support internet of things (IoT technologies.

Analyzing the effects of past prices on reference price formation

OpenAIRE

van Oest, R.D.; Paap, R.

2004-01-01

textabstractWe propose a new reference price framework for brand choice. In this framework, we employ a Markov-switching process with an absorbing state to model unobserved price recall of households. Reference prices result from the prices households are able to remember. Our model can be used to learn how many prices observed in the past are used for reference price formation. Furthermore, we learn to what extent households have sufficient price knowledge to form an internal reference price...

Monitoring the effect of football match congestion on hamstring strength and lower limb flexibility

DEFF Research Database (Denmark)

Wollin, Martin; Thorborg, Kristian; Pizzari, Tania

2018-01-01

OBJECTIVES: To investigate the effect of competitive football match congestion on hamstring strength and lower limb flexibility. DESIGN: Repeated measures. SETTING: Elite male youth football. PARTICIPANTS: Fifteen male elite youth football players from the national football association centre of ....... CONCLUSION: Isometric hamstring strength and pain can be considered for inclusion in-season to monitor player's post-match hamstring recovery characteristics during congested match fixtures.......OBJECTIVES: To investigate the effect of competitive football match congestion on hamstring strength and lower limb flexibility. DESIGN: Repeated measures. SETTING: Elite male youth football. PARTICIPANTS: Fifteen male elite youth football players from the national football association centre...... of excellence were included (age = 15.81 ±0.65 years, height = 171.95 ±6.89 cm, weight = 65.93 ±7.53 kg). MAIN OUTCOME MEASURES: Hamstring strength and pain, ankle dorsiflexion, hip extension, knee extension and flexion range of motion. RESULTS: Hamstring strength was highest at baseline and significantly...

Fast Lagrangian relaxation for constrained generation scheduling in a centralized electricity market

International Nuclear Information System (INIS)

Ongsakul, Weerakorn; Petcharaks, Nit

2008-01-01

This paper proposes a fast Lagrangian relaxation (FLR) for constrained generation scheduling (CGS) problem in a centralized electricity market. FLR minimizes the consumer payment rather than the total supply cost subject to the power balance, spinning reserve, transmission line, and generator operating constraints. FLR algorithm is improved by new initialization of Lagrangian multipliers and adaptive adjustment of Lagrangian multipliers. The adaptive subgradient method using high quality initial feasible multipliers requires much less number of iterations to converge, leading to a faster computational time. If congestion exists, the alleviating congestion index is proposed for congestion management. Finally, the unit decommitment is performed to prevent excessive spinning reserve. The FLR for CGS is tested on the 4 unit and the IEEE 24 bus reliability test systems. The proposed uniform electricity price results in a lower consumer payment than system marginal price based on uniformly fixed cost amortized allocation, non-uniform price, and electricity price incorporating side payment, leading to a lower electricity price. In addition, observations on objective functions, pricing scheme comparison and interpretation of Lagrangian multipliers are provided. (author)

Forecasting Day-Ahead Electricity Prices : Utilizing Hourly Prices

NARCIS (Netherlands)

E. Raviv (Eran); K.E. Bouwman (Kees); D.J.C. van Dijk (Dick)

2013-01-01

textabstractThe daily average price of electricity represents the price of electricity to be delivered over the full next day and serves as a key reference price in the electricity market. It is an aggregate that equals the average of hourly prices for delivery during each of the 24 individual

Reliability-Based Marginal Cost Pricing Problem Case with Both Demand Uncertainty and Travelers’ Perception Errors

Directory of Open Access Journals (Sweden)

Shaopeng Zhong

2013-01-01

Full Text Available Focusing on the first-best marginal cost pricing (MCP in a stochastic network with both travel demand uncertainty and stochastic perception errors within the travelers’ route choice decision processes, this paper develops a perceived risk-based stochastic network marginal cost pricing (PRSN-MCP model. Numerical examples based on an integrated method combining the moment analysis approach, the fitting distribution method, and the reliability measures are also provided to demonstrate the importance and properties of the proposed model. The main finding is that ignoring the effect of travel time reliability and travelers’ perception errors may significantly reduce the performance of the first-best MCP tolls, especially under high travelers’ confidence and network congestion levels. The analysis result could also enhance our understanding of (1 the effect of stochastic perception error (SPE on the perceived travel time distribution and the components of road toll; (2 the effect of road toll on the actual travel time distribution and its reliability measures; (3 the effect of road toll on the total network travel time distribution and its statistics; and (4 the effect of travel demand level and the value of reliability (VoR level on the components of road toll.

Oil prices and the stock prices of alternative energy companies

International Nuclear Information System (INIS)

Henriques, Irene; Sadorsky, Perry

2008-01-01

Energy security issues coupled with increased concern over the natural environment are driving factors behind oil price movements. While it is widely accepted that rising oil prices are good for the financial performance of alternative energy companies, there has been relatively little statistical work done to measure just how sensitive the financial performance of alternative energy companies are to changes in oil prices. In this paper, a four variable vector autoregression model is developed and estimated in order to investigate the empirical relationship between alternative energy stock prices, technology stock prices, oil prices, and interest rates. Our results show technology stock prices and oil prices each individually Granger cause the stock prices of alternative energy companies. Simulation results show that a shock to technology stock prices has a larger impact on alternative energy stock prices than does a shock to oil prices. These results should be of use to investors, managers and policy makers. (author)

123I-meta-iodo-benzyl-guanidine myocardial scintigraphy and congestive heart failure: current data and perspective

International Nuclear Information System (INIS)

Agostini, D.; Darlas, Y.; Quennelle, F.; Bouvard, G.; Scanu, P.; Grollier, G.; Potier, J.C.; Babatasi, G.; Belin, A.

1997-01-01

Congestive heart failure is often associated with an impairment of the sympathetic nervous system, i.e., global hyperactivity and regional impairment of the adrenergic system. Cardiac 123 I-MIBG scintigraphy is a radionuclide technique which can explore the presynaptic adrenergic function. Myocardial MIBG fixation is decreased in congestive heart failure, reflecting a reduction of norepinephrine uptake by the myocardial presynaptic nerve endings. The impairment of presynaptic function occurs early in the disease and is actually involved in the pathogenesis of cardiac failure. Cardiac MIBG scintigraphy is a useful tool to explore the myocardial adrenergic stores in patients with congestive heart failure. It could be proposed in patients with severe ventricular dysfunction in order to assist physicians in setting-up the timing of heart transplantation. (authors)

Forecasting Day-Ahead Electricity Prices: Utilizing Hourly Prices

OpenAIRE

Raviv, Eran; Bouwman, Kees E.; van Dijk, Dick

2013-01-01

This discussion paper led to a publication in 'Energy Economics' , 2015, 50, 227-239. The daily average price of electricity represents the price of electricity to be delivered over the full next day and serves as a key reference price in the electricity market. It is an aggregate that equals the average of hourly prices for delivery during each of the 24 individual hours. This paper demonstrates that the disaggregated hourly prices contain useful predictive information for the daily average ...

Congestion patterns of electric vehicles with limited battery capacity

Science.gov (United States)

2018-01-01

The path choice behavior of battery electric vehicle (BEV) drivers is influenced by the lack of public charging stations, limited battery capacity, range anxiety and long battery charging time. This paper investigates the congestion/flow pattern captured by stochastic user equilibrium (SUE) traffic assignment problem in transportation networks with BEVs, where the BEV paths are restricted by their battery capacities. The BEV energy consumption is assumed to be a linear function of path length and path travel time, which addresses both path distance limit problem and road congestion effect. A mathematical programming model is proposed for the path-based SUE traffic assignment where the path cost is the sum of the corresponding link costs and a path specific out-of-energy penalty. We then apply the convergent Lagrangian dual method to transform the original problem into a concave maximization problem and develop a customized gradient projection algorithm to solve it. A column generation procedure is incorporated to generate the path set. Finally, two numerical examples are presented to demonstrate the applicability of the proposed model and the solution algorithm. PMID:29543875

Congestion patterns of electric vehicles with limited battery capacity.

Science.gov (United States)

Jing, Wentao; Ramezani, Mohsen; An, Kun; Kim, Inhi

2018-01-01

The path choice behavior of battery electric vehicle (BEV) drivers is influenced by the lack of public charging stations, limited battery capacity, range anxiety and long battery charging time. This paper investigates the congestion/flow pattern captured by stochastic user equilibrium (SUE) traffic assignment problem in transportation networks with BEVs, where the BEV paths are restricted by their battery capacities. The BEV energy consumption is assumed to be a linear function of path length and path travel time, which addresses both path distance limit problem and road congestion effect. A mathematical programming model is proposed for the path-based SUE traffic assignment where the path cost is the sum of the corresponding link costs and a path specific out-of-energy penalty. We then apply the convergent Lagrangian dual method to transform the original problem into a concave maximization problem and develop a customized gradient projection algorithm to solve it. A column generation procedure is incorporated to generate the path set. Finally, two numerical examples are presented to demonstrate the applicability of the proposed model and the solution algorithm.

Nationwide SIP Telephony Network Design to Prevent Congestion Caused by Disaster

Science.gov (United States)

Satoh, Daisuke; Ashitagawa, Kyoko

We present a session initiation protocol (SIP) network design for a voice-over-IP network to prevent congestion caused by people calling friends and family after a disaster. The design increases the capacity of SIP servers in a network by using all of the SIP servers equally. It takes advantage of the fact that equipment for voice data packets is different from equipment for signaling packets in SIP networks. Furthermore, the design achieves simple routing on the basis of telephone numbers. We evaluated the performance of our design in preventing congestion through simulation. We showed that the proposed design has roughly 20 times more capacity, which is 57 times the normal load, than the conventional design if a disaster were to occur in Niigata Prefecture struck by the Chuetsu earthquake in 2004.

On the inefficiency of equilibria in linear bottleneck congestion games

NARCIS (Netherlands)

B. de Keijzer (Bart); G. Schäfer (Guido); O. Telelis (Orestis); S. Kontogiannis (Spyros); E. Koutsoupias (Elias); P.G. Spirakis (Paul)

2010-01-01

htmlabstractWe study the inefficiency of equilibrium outcomes in bottleneck congestion games. These games model situations in which strategic players compete for a limited number of facilities. Each player allocates his weight to a (feasible) subset of the facilities with the goal to minimize the

Embolization to treat pelvic congestion syndrome and vulval varicose veins.

NARCIS (Netherlands)

Vleuten, C.J.M. van der; Kempen, J.A.L. van; Schultze Kool, L.J.

2012-01-01

OBJECTIVE: To evaluate the efficacy of embolization for treating the symptoms of pelvic congestion syndrome (PCS). METHODS: Twenty-one women with PCS who were treated with embolization at Radboud University Nijmegen Medical Centre between 2003 and 2008 were sent a questionnaire about their symptoms

Design issues of a back-pressure-based congestion control mechanism

NARCIS (Netherlands)

Malhotra, R.; Mandjes, M.R.H.; Scheinhardt, W.R.W.; Berg, van den J.L.

2008-01-01

Congestion control in packet-based networks is often realized by feedback protocols -- in this paper we assess the performance under a back-pressure mechanism that has been proposed and standardized for Ethernet metropolitan networks. Relying on our earlier results for feedback fluid queues, we

Value of travel-time reliability, part II : a study of tradeoffs between travel reliability, congestion-mitigation strategies and emissions.

Science.gov (United States)

2012-09-01

Capacity, demand, and vehicle based emissions reduction strategies are compared for several pollutants employing aggregate US : congestion and vehicle fleet condition data. We find that congestion mitigation does not inevitably lead to reduced emissi...

Transmission expansion cost allocation based on cooperative game theory for congestion relief

Energy Technology Data Exchange (ETDEWEB)

Erli, Ge; Takahasi, Kazuhiro; Kurihara, Ikuo [Central Research Inst. of Electric Power Industry, Tokyo (Japan); Luonan Chen [Osaka Sangyo Univ., Osaka (Japan)

2005-01-01

In conventional power systems, upstream and downstream of power were distinct. However, due to the competition, power injection and sink can appear at unexpected locations, and cost sharing for such a new power system configuration must be considered. This paper proposes a scheme for transmission expansion cost allocation among electric market participants by using Core and Nucleolus concepts of game theory, which are developed particularly for the transmission users. A solution of the n-person cooperative game is adopted to distribute the line transmission expansion cost among the players. Congestion is assumed to be the transmission constraint, and expansion of transmission line is expected to relieve transmission congestion. A case study is illustrated to demonstrate the proposed method. (Author)

Higher Education Prices and Price Indexes. 1976 Supplement.

Science.gov (United States)

Halstead, Kent D.

The 1976 supplement presents higher education price index data for fiscal years 1971 through 1976. The basic study, "Higher Education Prices and Price Indexes" (ED 123 996) presents complete descriptions of the indexes together with index values and price data for fiscal years 1961 through 1974. Indexes are presented for research and development,…

Congestion and redispatch in Germany. A model-based analysis of the development of redispatch in Germany

Energy Technology Data Exchange (ETDEWEB)

Nuessler, Ariette

2012-07-01

In this dissertation a model to analyze the impact of recent developments of the electricity market on the national high-voltage transmission network from an economic perspective is developed. The purpose is to design a tool that allows including the costs induced on the network into an economic assessment in order to obtain a complete economic picture. In order to allow a reasonable application to the German electricity system and respective inferences, the concept of cost-based redispatch for network congestion relief is modeled. Furthermore, the concept of PTDF matrixes is integrated into the linear dispatch model DIANA thereby modeling the physical characteristics of electricity transmission. The model is applied to the prospective development of the German electricity system by use of a scenario analysis. By this means, the development of redispatch costs and quantities in Germany in the prospective years are highlighted. It can be shown that despite investments in the transmission infrastructure, the costs and quantities of redispatch increase in the course of time. Although the magnitude of this increase varies from scenario to scenario, a general trend of increasing costs and quantities can be observed for all scenarios. Moreover, the foreseeable development of the electricity market makes network extensions indispensable. Such network extensions, however, should not only be evaluated from a technical perspective, but should also be judged economically. As shown, the developed model can be used for such an economic assessment of investments in the transmission infrastructure. Finally, the model results show that the current German market design of cost-based redispatch becomes insufficient for resolving congestion from a technical perspective. The use of dummy redispatch in the model hereby indicates a regional shortage of generation capacity available for redispatch (or the need to curtail demand). As a consequence, the results in this dissertation reveal

Another look on the relationships between oil prices and energy prices

International Nuclear Information System (INIS)

Lahiani, Amine; Miloudi, Anthony; Benkraiem, Ramzi; Shahbaz, Muhammad

2017-01-01

This paper employs the Quantile Autoregressive Distributed Lags (QARDL) model developed recently by Cho et al. (2015) to investigate the pass-through of oil prices to a set of energy prices. This approach allows analyzing simultaneously short-term connections and long-run cointegrating relationships across a range of quantiles. It also provides insights on the short-run predictive power of oil prices in predicting energy prices while accounting for the cointegration between oil prices and each of the considered energy prices in low, medium and high quantiles. Two key findings emerge from this paper. First, all considered energy prices are shown to be cointegrated with oil price across quantiles meaning that a stationaryequilibriumrelationship exists between single energy price and oil price. Second, we find evidence that oil price is a significant predictor of individual petroleum products prices and natural gas in the short run. This paper has important policy implications for forecasters, energy policy-makers and portfolio managers. - Highlights: • The pass-through of oil prices to a set of energy prices is investigated for US economy. • All considered energy prices are shown to be cointegrated with oil price across quantiles. • Oil price is a significant predictor of individual petroleum products prices in the short run. • Oil price also predicts natural gas prices in the short run.

Applications of variable speed control for contending with recurrent highway congestion.

Science.gov (United States)

2014-07-01

This research project developed vital operational guidelines for design of a variable speed limit (VSL) system and its integrated operations with ramp metering control in contending with recurrent highway congestion. The developed guidelines can serv...

Increasing Intelligence in Inter-Vehicle Communications to Reduce Traffic Congestions: Experiments in Urban and Highway Environments.

Directory of Open Access Journals (Sweden)

Rodolfo I Meneguette

Full Text Available Intelligent Transportation Systems (ITS rely on Inter-Vehicle Communication (IVC to streamline the operation of vehicles by managing vehicle traffic, assisting drivers with safety and sharing information, as well as providing appropriate services for passengers. Traffic congestion is an urban mobility problem, which causes stress to drivers and economic losses. In this context, this work proposes a solution for the detection, dissemination and control of congested roads based on inter-vehicle communication, called INCIDEnT. The main goal of the proposed solution is to reduce the average trip time, CO emissions and fuel consumption by allowing motorists to avoid congested roads. The simulation results show that our proposed solution leads to short delays and a low overhead. Moreover, it is efficient with regard to the coverage of the event and the distance to which the information can be propagated. The findings of the investigation show that the proposed solution leads to (i high hit rate in the classification of the level of congestion, (ii a reduction in average trip time, (iii a reduction in fuel consumption, and (iv reduced CO emissions.

Pricing Mining Concessions Based on Combined Multinomial Pricing Model

Directory of Open Access Journals (Sweden)

Chang Xiao

2017-01-01

Full Text Available A combined multinomial pricing model is proposed for pricing mining concession in which the annualized volatility of the price of mineral products follows a multinomial distribution. First, a combined multinomial pricing model is proposed which consists of binomial pricing models calculated according to different volatility values. Second, a method is provided to calculate the annualized volatility and the distribution. Third, the value of convenience yields is calculated based on the relationship between the futures price and the spot price. The notion of convenience yields is used to adjust our model as well. Based on an empirical study of a Chinese copper mine concession, we verify that our model is easy to use and better than the model with constant volatility when considering the changing annualized volatility of the price of the mineral product.

Standardized evaluation of lung congestion during COPD exacerbation better identifies patients at risk of dying

Directory of Open Access Journals (Sweden)

Høiseth AD

2013-12-01

Full Text Available Arne Didrik Høiseth,1 Torbjørn Omland,1 Bo Daniel Karlsson,2 Pål H Brekke,1 Vidar Søyseth11Cardiothoracic Research Group, Division of Medicine, Akershus University Hospital and Institute of Clinical Medicine, University of Oslo, Oslo, Norway; 2Deptartment of Radiology, Akershus University Hospital, Lørenskog, NorwayBackground: Congestive heart failure is underdiagnosed in patients with chronic obstructive pulmonary disease (COPD. Pulmonary congestion on chest radiograph at admission for acute exacerbation of COPD (AECOPD is associated with an increased risk of mortality. A standardized evaluation of chest radiographs may enhance prognostic accuracy.Purpose: We aimed to evaluate whether a standardized, liberal assessment of pulmonary congestion is superior to the routine assessment in identifying patients at increased risk of long-term mortality, and to investigate the association of heart failure with N-terminal prohormone of brain natriuretic peptide (NT-proBNP concentrations.Material and methods: This was a prospective cohort study of 99 patients admitted for AECOPD. Chest radiographs obtained on admission were routinely evaluated and then later evaluated by blinded investigators using a standardized protocol looking for Kerley B lines, enlarged vessels in the lung apex, perihilar cuffing, peribronchial haze, and interstitial or alveolar edema, defining the presence of pulmonary congestion. Adjusted associations with long-term mortality and NT-proBNP concentration were calculated.Results: The standardized assessment was positive for pulmonary congestion in 32 of the 195 radiographs (16% ruled negative in the routine assessment. The standardized assessment was superior in predicting death during a median follow up of 1.9 years (P=0.022, and in multivariable analysis, only the standardized assessment showed a significant association with mortality (hazard ratio 2.4, 95% confidence interval [CI] 1.2–4.7 (P=0.016 and NT-proBNP (relative

Congestion Service Facilities Location Problem with Promise of Response Time

Directory of Open Access Journals (Sweden)

Dandan Hu

2013-01-01

Full Text Available In many services, promise of specific response time is advertised as a commitment by the service providers for the customer satisfaction. Congestion on service facilities could delay the delivery of the services and hurts the overall satisfaction. In this paper, congestion service facilities location problem with promise of response time is studied, and a mixed integer nonlinear programming model is presented with budget constrained. The facilities are modeled as M/M/c queues. The decision variables of the model are the locations of the service facilities and the number of servers at each facility. The objective function is to maximize the demands served within specific response time promised by the service provider. To solve this problem, we propose an algorithm that combines greedy and genetic algorithms. In order to verify the proposed algorithm, a lot of computational experiments are tested. And the results demonstrate that response time has a significant impact on location decision.

The impact of electricity price changes on industrial prices and the general price level in Korea

International Nuclear Information System (INIS)

Lim, Seul-Ye; Yoo, Seung-Hoon

2013-01-01

Electricity has played an important role in the economic development of Korea and, thus, has become a critical factor in sustaining the well-being of the Korean people. This study attempts to investigate the impact of electricity price changes on industrial prices and the general price level using input–output (I–O) analysis. To this end, we apply the I–O price model to the 2011 I–O table recently produced by the Bank of Korea, paying particular attention to the electricity sector by considering it as exogenous and then investigating its impacts. The impacts of the electricity price changes on each industrial sector's prices and the general price level are quantitatively derived. For example, the overall impact of a 10% increase in electricity price on the Korean national economy is estimated to be 0.4367%. We also report the results from the model with the electricity sector endogenous and the model with endogenous electricity and labor sectors. This information can be usefully utilized in decision-making regarding price management for electricity. - Highlights: • We investigate the impact of electricity price changes on the Korean economy. • We use the input–output (I–O) analysis specifying the electricity sector as exogenous. • We apply the I–O price model to 2010 I–O table produced by the Bank of Korea. • The impact of a 10% increase in electricity price on the Korean economy is 0.2176%

Incorporating travel-time reliability into the congestion management process : a primer.

Science.gov (United States)