WorldWideScience

Sample records for nonsemantic control demands

  1. Demand as Frequency Controlled Reserve

    DEFF Research Database (Denmark)

    Xu, Zhao; Togeby, Mikael; Østergaard, Jacob

    This report summaries the research outcomes of the project ‘Demand as Frequency Controlled Reserve (DFR)’, which has received the support from Energinet.dk’s PSO program, Grant no. 2005-2-6380. The objective of this project is to investigate the technology of using electricity demands for providing...

  2. Voltage Controlled Dynamic Demand Response

    DEFF Research Database (Denmark)

    Bhattarai, Bishnu Prasad; Bak-Jensen, Birgitte; Mahat, Pukar

    2013-01-01

    Future power system is expected to be characterized by increased penetration of intermittent sources. Random and rapid fluctuations in demands together with intermittency in generation impose new challenges for power balancing in the existing system. Conventional techniques of balancing by large...... central or dispersed generations might not be sufficient for future scenario. One of the effective methods to cope with this scenario is to enable demand response. This paper proposes a dynamic voltage regulation based demand response technique to be applied in low voltage (LV) distribution feeders....... An adaptive dynamic model has been developed to determine composite voltage dependency of an aggregated load on feeder level. Following the demand dispatch or control signal, optimum voltage setting at the LV substation is determined based on the voltage dependency of the load. Furthermore, a new technique...

  3. Demand as Frequency Controlled Reserve

    DEFF Research Database (Denmark)

    Xu, Zhao; Østergaard, Jacob; Togeby, Mikael

    2011-01-01

    Relying on generation side alone is deemed insufficient to fulfill the system balancing needs for future Danish power system, where a 50% wind penetration is outlined by the government for year 2025. This paper investigates using the electricity demand as frequency controlled reserve (DFR) as a new...... balancing measure, which has a high potential and can provide many advantages. Firstly, the background of the research is reviewed, including conventional power system reserves and the electricity demand side potentials. Subsequently, the control logics and corresponding design considerations for the DFR...

  4. Demand controlled ventilation; Behovsstyrt ventilasjon

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, Henning Holm

    2006-07-01

    The terms CAV and VAV have been known terms for many years in the ventilation business. The terms are also included in building regulations, but the time is now right to focus on demand controlled ventilation (DCV). The new building regulations and the accompanying energy framework underline the need for a more nuanced thinking when it comes to controlling ventilation systems. Descriptions and further details of the ventilation systems are provided (ml)

  5. Demand Controlled Ventilation and Classroom Ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mendell, Mark J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Davies, Molly [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Eliseeva, Ekaterina [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Faulkner, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hong, Tienzen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sullivan, Douglas P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-05-01

    This document summarizes a research effort on demand controlled ventilation and classroom ventilation. The research on demand controlled ventilation included field studies and building energy modeling.

  6. Demand controlled ventilation and classroom ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mendell, Mark J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Davies, Molly [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Eliseeva, Ekaterina [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Faulkner, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hong, Tienzen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sullivan, Douglas P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-01-06

    This document summarizes a research effort on demand controlled ventilation and classroom ventilation. The research on demand controlled ventilation included field studies and building energy modeling.

  7. Demand as frequency controlled reserve

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Z.; Togeby, M.; OEstergaard, J.

    2008-09-15

    Using demand as frequency controlled reserve (DFR) is an emerging technology which allow demand to participate actively in maintaining the system operation without reducing the energy service delivered to the customer and without need of user interaction. The basic premise is that traditional frequency controlled reserves from power plants and interconnections with neighbouring systems can be costly, slow and not fulfil the need for future power grids with a high share of wind power and fewer central power plants, and an intention to perform flexible operation such as is landing. Electricity demands, on the other hand, have advantages as frequency reserve including fast activation speed, smooth linear activation, low expected costs, and well-dispersed in the distribution grid. The main challenge of DFR is new methods for monitoring the available capacity. This project has investigated the technology of using electricity demands for providing frequency reserve to power systems. Within the project the potential and economy of DFR compatible loads in Denmark has been investigated, control logic has been designed, power system impact has been investigated, potential business models has been evaluated and an implementation strategy has been suggested. The tasks and goals of the project have been successfully accomplished based on which the conclusion and future recommendation are made. This project has developed the DFR technology that enables electricity demands to autonomously disconnect or reconnect to the grid in response to system frequency variations. The developed DFR technology is proved to be a promising technology from several perspectives. Technically, using DFR is feasible to provide reserves and enhance power system frequency control, while fulfilling technical requirements such as linear activation (or reconnection) according to frequency (or time). Environmentally, the DFR technology is pollution free in contrast to traditional reserves from generation

  8. Controlling energy demand. What history?

    International Nuclear Information System (INIS)

    Beers, Marloes; Bonhomme, Noel; Bouvier, Yves; Pautard, Eric; Fevrier, Patrick; Lanthier, Pierre; Goyens, Valerie; Desama, Claude; Beltran, Alain

    2012-01-01

    this special dossier of the historical annals of electricity collection takes stock of the post 1970's history of energy demand control in industrialized countries: Abatement of energy dependence, the European Communities program of rational use of energy in the 1970's (Marloes Beers); The G7 and the energy cost: the limits of dialogue between industrialized countries - 1975-1985 (Noel Bonhomme); Saving more to consume more. The ambiguity of EDF's communication during the 'energy saving' era (Yves Bouvier); From rationing to energy saving certificates, 4 decades of electricity demand control in France and in the UK (eric Pautard); The French agency of environment and energy mastery (ADEME): between energy control and sustainable development (Patrick Fevrier); Hydro-Quebec and efficiency in household energy consumption, from 1990 to the present day (Pierre Lanthier); Control of energy consumption since the 1970's, the policy of rational use of energy in Walloon region - Belgium (Valerie Goyens); Electricity distribution in the new energy paradigm (Claude Desama); Conclusion (Alain Beltran)

  9. Cut Electric Bills by Controlling Demand

    Science.gov (United States)

    Grumman, David L.

    1974-01-01

    Electric bills can be reduced by lowering electric consumption and by controlling demand -- the amount of electricity used at a certain point in time. Gives tips to help reduce electric demand at peak power periods. (Author/DN)

  10. Demand controlled ventilation in a bathroom

    DEFF Research Database (Denmark)

    Mortensen, Dorthe Kragsig; Nielsen, Toke Rammer; Topp, Claus

    2008-01-01

    consumption during periods where the demand for ventilation is low and poor indoor climate during periods where the demand for ventilation is high. Controlling the ventilation rate by demand can improve the energy performance of the ventilation system and the indoor climate. This paper compares the indoor...... climate and energy consumption of a Constant Air Volume (CAV) system and a Demand Controlled Ventilation (DCV) system for two different bathroom designs. The air change rate of the CAV system corresponded to 0.5h-1. The ventilation rate of the DCV system was controlled by occupancy and by the relative...

  11. Inventory control in case of unknown demand and control parameters

    NARCIS (Netherlands)

    Janssen, E.

    2010-01-01

    This thesis deals with unknown demand and control parameters in inventory control. Inventory control involves decisions on what to order when and in what quantity. These decisions are based on information about the demand. Models are constructed using complete demand information; these models ensure

  12. Bandwidth-on-demand motion control

    NARCIS (Netherlands)

    Van Loon, S.J.L.M.; Hunnekens, B.G.B.; Simon, A.S.; van de Wouw, N.; Heemels, W.P.M.H.

    2018-01-01

    In this brief, we introduce a 'bandwidth-on-demand' variable-gain control (VGC) strategy that allows for a varying bandwidth of the feedback controller. The proposed VGC can achieve improved performance given time-varying, reference-dependent performance requirements compared with linear

  13. Demand-controlling marketing of electric utilities

    Energy Technology Data Exchange (ETDEWEB)

    Raffee, H; Fritz, W

    1980-01-01

    In situations like the shortage of energy resources the particular autonomy of the users concerning energy demand raises more and more aggravating problems for the electric utilities (EU) and, last not least, for society (i.e. the peak-load problem, threatening bottlenecks in the supply situation). Thus the requirement for a demand-controlling marketing strategy of the EU with the help of which the individual demand should be influenced in the following manner is legitimate. The article discusses the targets, strategies, and instruments of marketing performed by the EU under the aspect of their efficiency concerning demand control. The discussion leads to e.g. the following results: that a marketing strategy for the sensible, responsible, and efficent use of energy, in the long-term, serves both the interests of the users and the interests of the EU; that such a marketing programme can have the required controlling effects especially with the help of strategies like market segmentation and cooperation. The discussion makes also clear that a demand-controlling marketing strategy of the EU can hardly be realized without a considerable change within the organization of the EU on one hand and, on the other, without expanding the marketing programme toward a marketing strategy of balance.

  14. Supply-demand controls the futures

    International Nuclear Information System (INIS)

    Brown, D.

    1991-01-01

    This paper briefly discusses the futures market of petroleum and explains how futures operate. The purpose of the paper is to demonstrate that oil futures markets does no determine energy prices - it merely reflects the prices recorded through trades made in an open marketplace. A futures contract is an agreement between a buyer and a seller at a price that seems fair to both. High demand from buyers can push prices up; low demand or a willingness to sell pushes prices down. As a result, supply and demand control the futures exchange and not vice-versa. The paper goes on to explain some basic principals of the futures market including the differences between hedging and speculating on prices and marketing strategy

  15. Acceptable noise level with Danish, Swedish, and non-semantic speech materials

    DEFF Research Database (Denmark)

    Brännström, K Jonas; Lantz, Johannes; Nielsen, Lars Holme

    2012-01-01

    reported results from American studies. Generally, significant differences were seen between test conditions using different types of noise within ears in each population. Significant differences were seen for ANL across populations, also when the non-semantic ISTS was used as speech signal. Conclusions......Abstract Objective: Acceptable noise level (ANL) has been established as a method to quantify the acceptance of background noise while listening to speech presented at the most comfortable level. The aim of the present study was to generate Danish, Swedish, and a non-semantic version of the ANL...... test and investigate normal-hearing Danish and Swedish subjects' performance on these tests. Design: ANL was measured using Danish and Swedish running speech with two different noises: Speech-weighted amplitude-modulated noise, and multitalker speech babble. ANL was also measured using the non...

  16. A patient with aphasia using the nonsemantic lexical route for Kanji reading.

    Science.gov (United States)

    Hashimoto, Kosei; Uno, Akira; Sambai, Ami; Mizumoto, Go

    We report a patient with aphasia, caused by cerebral hemorrhage, who probably used the nonsemantic lexical route when reading words aloud. To investigate the mechanisms underlying her reading dysfunction, we analyzed her reading abilities using the Dual-Route Cascaded Model. Language tests resulted in low correct percentages for both reading comprehension and reading nonwords aloud, suggesting problems in the semantic system and the nonlexical route. Conversely, the patient showed high scores on the reading words aloud task. Although she failed to understand many inconsistent-atypical words in the reading comprehension test, she correctly read most words aloud, suggesting that she used the nonsemantic lexical route. In addition, the lexical reading route was analyzed in detail by using inconsistent-atypical Kanji words as stimuli. Finally, we analyzed her reading dysfunction compared with previous cases.

  17. Demand as Frequency-controlled Reserve

    DEFF Research Database (Denmark)

    Bang, Christian; Rasmussen, Christian Brandt; Østergaard, Jacob

    with great enthusiasm from all DFR project members who have shown a memorable dedication to their work. Active control of electricity demand is a key technology when creating a more dynamic, wind power friendly energy system. In this demonstration project, we have developed and tested devices, which use...... electric loads to provide frequency controlled primary reserves. The devices collected data from domestic households and industrial loads covering i.e. circulation pumps, electrical domestic heating, bottle coolers, a wastewater treatment plant etc., that have been analysed and used for the papers...

  18. Sensor-based demand controlled ventilation

    Energy Technology Data Exchange (ETDEWEB)

    De Almeida, A.T. [Universidade de Coimbra (Portugal). Dep. Eng. Electrotecnica; Fisk, W.J. [Lawrence Berkeley National Lab., CA (United States)

    1997-07-01

    In most buildings, occupancy and indoor pollutant emission rates vary with time. With sensor-based demand-controlled ventilation (SBDCV), the rate of ventilation (i.e., rate of outside air supply) also varies with time to compensate for the changes in pollutant generation. In other words, SBDCV involves the application of sensing, feedback and control to modulate ventilation. Compared to ventilation without feedback, SBDCV offers two potential advantages: (1) better control of indoor pollutant concentrations; and (2) lower energy use and peak energy demand. SBDCV has the potential to improve indoor air quality by increasing the rate of ventilation when indoor pollutant generation rates are high and occupants are present. SBDCV can also save energy by decreasing the rate of ventilation when indoor pollutant generation rates are low or occupants are absent. After providing background information on indoor air quality and ventilation, this report provides a relatively comprehensive discussion of SBDCV. Topics covered in the report include basic principles of SBDCV, sensor technologies, technologies for controlling air flow rates, case studies of SBDCV, application of SBDCV to laboratory buildings, and research needs. SBDCV appears to be an increasingly attractive technology option. Based on the review of literature and theoretical considerations, the application of SBDCV has the potential to be cost-effective in applications with the following characteristics: (a) a single or small number of dominant pollutants, so that ventilation sufficient to control the concentration of the dominant pollutants provides effective control of all other pollutants; (b) large buildings or rooms with unpredictable temporally variable occupancy or pollutant emission; and (c) climates with high heating or cooling loads or locations with expensive energy.

  19. Grower demand for sensor-controlled irrigation

    Science.gov (United States)

    Lichtenberg, Erik; Majsztrik, John; Saavoss, Monica

    2015-01-01

    Water scarcity is likely to increase in the coming years, making improvements in irrigation efficiency increasingly important. An emerging technology that promises to increase irrigation efficiency substantially is a wireless irrigation sensor network that uploads sensor data into irrigation management software, creating an integrated system that allows real-time monitoring and control of moisture status that has been shown in experimental settings to reduce irrigation costs, lower plant loss rates, shorten production times, decrease pesticide application, and increase yield, quality, and profit. We use an original survey to investigate likely initial acceptance, ceiling adoption rates, and profitability of this new sensor network technology in the nursery and greenhouse industry. We find that adoption rates for a base system and demand for expansion components are decreasing in price, as expected. The price elasticity of the probability of adoption suggests that sensor networks are likely to diffuse at a rate somewhat greater than that of drip irrigation. Adoption rates for a base system and demand for expansion components are increasing in specialization in ornamental production: growers earning greater shares of revenue from greenhouse and nursery operations are willing to pay more for a base system and are willing to purchase larger numbers of expansion components at any given price. We estimate that growers who are willing to purchase a sensor network expect investment in this technology to generate significant profit, consistent with findings from experimental studies.

  20. Demand Response on domestic thermostatically controlled loads

    DEFF Research Database (Denmark)

    Lakshmanan, Venkatachalam

    . For a safe and reliable operation of electric power systems, the balance between electricity generation and consumption has to be maintained. The conventional fossil fuel based power generation achieves this balance by adjusting the generation to follow the consumption. In the electric power system......Electricity has become an inevitable part of human life in present day world. In the past two centuries, the electric power system has undergone a lot of changes. Due to the awareness about the adverse impact of the fossil fuels, the power industry is adopting green and sustainable energy sources....... In general, the electricity consumers are classified as industrial, commercial and domestic. In this dissertation, only the thermostatically controlled loads (TCLs) in the domestic segment are considered for the demand response study. The study is funded by Danish Council for Strategic Research (DCSR...

  1. History of demand side management and classification of demand response control schemes

    NARCIS (Netherlands)

    Lampropoulos, I.; Kling, W.L.; Ribeiro, P.F.; Berg, van den J.

    2013-01-01

    The scope of this paper is to provide a review on the topic of demand side management. A historical overview provides a critical insight to applied cases, while the discovery of new evidence calls for reconsideration of the design of demand response control schemes. The developments at the demand

  2. Lighting Systems Control for Demand Response

    NARCIS (Netherlands)

    Husen, S.A.; Pandharipande, A.; Tolhuizen, L.M.G.; Wang, Y.; Zhao, M.

    2012-01-01

    Lighting is a major part of energy consumption in buildings. Lighting systems will thus be one of the important component systems of a smart grid for dynamic load management services like demand response.In the scenario considered in this paper, under a demand response request, lighting systems in a

  3. Acceptable noise level (ANL) with Danish and non-semantic speech materials in adult hearing-aid users

    DEFF Research Database (Denmark)

    Olsen, Steen Østergaard; Lantz, Johannes; Nielsen, Lars Holme

    2012-01-01

    The acceptable noise level (ANL) test is used for quantification of the amount of background noise subjects accept when listening to speech. This study investigates Danish hearing-aid users' ANL performance using Danish and non-semantic speech signals, the repeatability of ANL, and the association...... between ANL and outcome of the international outcome inventory for hearing aids (IOI-HA)....

  4. Acceptable noise level (ANL) with Danish and non-semantic speech materials in adult hearing-aid users

    DEFF Research Database (Denmark)

    Olsen, Steen Østergaard; Lantz, Johannes; Nielsen, Lars Holme

    2012-01-01

    The acceptable noise level (ANL) test is used for quantification of the amount of background noise subjects accept when listening to speech. This study investigates Danish hearing-aid users' ANL performance using Danish and non-semantic speech signals, the repeatability of ANL, and the association...

  5. Cognitive task demands, self-control demands and the mental well-being of office workers.

    Science.gov (United States)

    Bridger, Robert S; Brasher, Kate

    2011-09-01

    The cognitive task demands of office workers and the self-control demands of their work roles were measured in a sample of 196 employees in two different office layouts using a self-report questionnaire, which was circulated electronically. Multiple linear regression analysis revealed that both factors were associated with mental well-being, but not with physical well-being, while controlling for exposure to psychosocial stressors. The interaction between cognitive task demands and self-control demands had the strongest association with mental well-being, suggesting that the deleterious effect of one was greater when the other was present. An exploratory analysis revealed that the association was stronger for employees working in a large open-plan office than for those working in smaller offices with more privacy. Frustration of work goals was the cognitive task demand having the strongest negative impact on mental well-being. Methodological limitations and scale psychometrics (particularly the use of the NASA Task Load Index) are discussed. STATEMENT OF RELEVANCE: Modern office work has high mental demands and low physical demands and there is a need to design offices to prevent adverse psychological reactions. It is shown that cognitive task demands interact with self-control demands to degrade mental well-being. The association was stronger in an open-plan office.

  6. An Intuitive Definition of Demand Flexibility in Direct Load Control

    DEFF Research Database (Denmark)

    Tahersima, Fatemeh; Madsen, Per Printz; Andersen, Palle

    2013-01-01

    Two control approaches: direct and indirect control of demand side energy management in a smart grid are studied. Indirect control of energy demands is based on economic incentives. In this approach, consumers will shift their energy consumption with the benefit of a cut down in the electricity b...

  7. Do job demands and job control affect problem-solving?

    Science.gov (United States)

    Bergman, Peter N; Ahlberg, Gunnel; Johansson, Gun; Stoetzer, Ulrich; Aborg, Carl; Hallsten, Lennart; Lundberg, Ingvar

    2012-01-01

    The Job Demand Control model presents combinations of working conditions that may facilitate learning, the active learning hypothesis, or have detrimental effects on health, the strain hypothesis. To test the active learning hypothesis, this study analysed the effects of job demands and job control on general problem-solving strategies. A population-based sample of 4,636 individuals (55% women, 45% men) with the same job characteristics measured at two times with a three year time lag was used. Main effects of demands, skill discretion, task authority and control, and the combined effects of demands and control were analysed in logistic regressions, on four outcomes representing general problem-solving strategies. Those reporting high on skill discretion, task authority and control, as well as those reporting high demand/high control and low demand/high control job characteristics were more likely to state using problem solving strategies. Results suggest that working conditions including high levels of control may affect how individuals cope with problems and that workplace characteristics may affect behaviour in the non-work domain.

  8. Demand controlled ventilation for multi-family dwellings

    DEFF Research Database (Denmark)

    Mortensen, Dorthe Kragsig

    for centrally balanced DCV systems with heat recovery. A design expected to fulfill this requirement was investigated in detail with regard to its electricity consumption by evaluating a control strategy that resets the static pressure set point at part load. The results showed that this control strategy can......The present thesis “Demand controlled ventilation for multi-family dwellings” constitutes the summary of a three year project period during which demand specification and system design of demand controlled ventilation for residential buildings were studied. Most standards and buildings codes...... can be reduced compared to a system with constant air flow. A literature study on indoor pollutants in homes, their sources and their impact on humans formed the basis for the demand specification. Emission of pollutants in residential buildings roughly fall into constantly emitted background sources...

  9. Performance Assessment of Aggregation Control Services for Demand Response

    DEFF Research Database (Denmark)

    Bondy, Daniel Esteban Morales; Costanzo, Giuseppe Tommaso; Heussen, Kai

    2014-01-01

    Aggregation algorithms that provide services to the grid via demand side management are moving from research ideas to the market. With the diversity of the technology delivering such services, it becomes essential to establish transparent performance standards from a service delivery perspective...... of the quality of service provided by an aggregation control algorithm. By a detailed case study we present and an application of the index, comparing the performance of two different control architectures for demand side management delivering a distribution grid service....

  10. Energy efficient demand controlled ventilation in single family houses

    DEFF Research Database (Denmark)

    Nielsen, Toke Rammer; Drivsholm, Christian

    2010-01-01

    This paper presents a strategy for a simple demand controlled ventilation system for single family houses where all sensors and controls are located in the air handling unit. The strategy is based on sensing CO2-concentration and moisture content in the outdoor air and exhaust air. The CO2...

  11. Indirect control of flexible demand for power system applications

    DEFF Research Database (Denmark)

    Sossan, Fabrizio

    This thesis addresses the topic of control of flexible demand to provide support to the operation of the electric power system. We focus on the indirect control approach, a framework that enables demand response by means of a consumption incentive signal. Initially, the concept of flexibility...... a shift in the consumption according to an indirect control signal. We present from simple control algorithms with a few requirements up to model predictive control strategies. The performance of the indirect control algorithms are compared by means of hardware-in-the-loop simulations using Power...... and storage in the operation of the future power system, we develop a model predictive control strategy for a smart building with the objective of supplying iii space heating and providing regulating power to the grid according to a dynamic electricity price. We named this application energy replacement...

  12. Indirect Control for Demand Side Management – A Conceptual Introduction

    DEFF Research Database (Denmark)

    Heussen, Kai; You, Shi; Biegel, Benjamin

    2012-01-01

    The concept of “indirect control” has become a relevant discussion term in relation to activation distributed and small-scale demand and generation units to provide resources for power system balancing. The term and its association with price signals has, however caused some confusion as to its...... correct definition, either as a control or a market concept. This paper aims to provide a conceptual introduction to "indirect control" for management of small and distributed demand side resources. A review of control concepts and an analysis of "indirectness" features are provided to create a framework...... for systematic classification of indirect control strategies. The concepts developed then enable a discussion of control performance and valuation of direct- and indirect control strategies....

  13. Demand Management Based on Model Predictive Control Techniques

    Directory of Open Access Journals (Sweden)

    Yasser A. Davizón

    2014-01-01

    Full Text Available Demand management (DM is the process that helps companies to sell the right product to the right customer, at the right time, and for the right price. Therefore the challenge for any company is to determine how much to sell, at what price, and to which market segment while maximizing its profits. DM also helps managers efficiently allocate undifferentiated units of capacity to the available demand with the goal of maximizing revenue. This paper introduces control system approach to demand management with dynamic pricing (DP using the model predictive control (MPC technique. In addition, we present a proper dynamical system analogy based on active suspension and a stability analysis is provided via the Lyapunov direct method.

  14. How Tobacco Control Measures and Smuggling Influence Demand ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    How Tobacco Control Measures and Smuggling Influence Demand in Panama. Panama's tobacco epidemic demonstrates ... Their goal: establish a new threshold for increasing the luxury tax on tobacco products, including cigarettes, based on the monthly evolution of cigarette sales. The researchers will survey brands in ...

  15. Electric Water Heater Modeling and Control Strategies for Demand Response

    Energy Technology Data Exchange (ETDEWEB)

    Diao, Ruisheng; Lu, Shuai; Elizondo, Marcelo A.; Mayhorn, Ebony T.; Zhang, Yu; Samaan, Nader A.

    2012-07-22

    Abstract— Demand response (DR) has a great potential to provide balancing services at normal operating conditions and emergency support when a power system is subject to disturbances. Effective control strategies can significantly relieve the balancing burden of conventional generators and reduce investment on generation and transmission expansion. This paper is aimed at modeling electric water heaters (EWH) in households and tests their response to control strategies to implement DR. The open-loop response of EWH to a centralized signal is studied by adjusting temperature settings to provide regulation services; and two types of decentralized controllers are tested to provide frequency support following generator trips. EWH models are included in a simulation platform in DIgSILENT to perform electromechanical simulation, which contains 147 households in a distribution feeder. Simulation results show the dependence of EWH response on water heater usage . These results provide insight suggestions on the need of control strategies to achieve better performance for demand response implementation. Index Terms— Centralized control, decentralized control, demand response, electrical water heater, smart grid

  16. Production control and supplier selection under demand disruptions

    Directory of Open Access Journals (Sweden)

    Xianzhe Chen

    2010-12-01

    Full Text Available This paper investigates the effects of demand disruptions on production control and supplier selection in a three-echelon supply chain system. The customer demand is modeled as a jump-diffusion process in a continuous-time setting. A two-number production-inventory policy is implemented in the production control model for the manufacturer. The objective is to minimize the long-term average total cost consisting of backlog cost, holding cost, switching cost, and ordering cost. The simulated annealing method is applied to search the optimal critical switching values. Furthermore, an improved analytical hierarchy process (AHP is proposed to select the best supplier, based on quantitative factors such as the optimal long-term total cost obtained through the simulated annealing method under demand disruptions and qualitative factors such as quality and service. Numerical studies are conducted to demonstrate the effects of demand disruptions in the face of various risk scenarios. Managerial insights from simulation results are provided as well. Our approaches can be implemented as the “stress test” for companies in front of various supply chain disruption scenarios.

  17. Control strategies for demand controlled ventilation in dwellings

    DEFF Research Database (Denmark)

    Nielsen, Toke Rammer; Drivsholm, Christian

    2011-01-01

    and efficient fans is becoming the standard solution. The building regulation requirement for air change in dwellings is often a constant value that has been chosen to avoid moisture related problems in the indoor environment. This required air change is sometimes sufficient, sometimes too low and sometimes too....... In the studied house two control strategies were tested. A simple strategy where all sensors and controls were located in the air handling unit and only the speed of the fans can be controlled, and a complex strategy where sensors were placed in each room and where individual control of air flow in each room...

  18. Optimization of Occupancy Based Demand Controlled Ventilation in Residences

    DEFF Research Database (Denmark)

    Mortensen, Dorthe Kragsig; Walker, Iain; Sherman, Max

    2011-01-01

    Although it has been used for many years in commercial buildings, the application of demand controlled ventilation in residences is limited. In this study we used occupant exposure to pollutants integrated over time (referred to as "dose") as the metric to evaluate the effectiveness and air quality...... implications of demand controlled ventilation in residences. We looked at air quality for two situations. The first is that typically used in ventilation standards: the exposure over a long term. The second is to look at peak exposures that are associated with time variations in ventilation rates and pollutant...... when occupied. We used analytical solutions to the continuity equation to determine the ventilation effectiveness and the long-term chronic dose and peak acute exposure for a representative range of occupancy periods, pollutant generation rates and airflow rates. The results of the study showed that we...

  19. A demand assignment control in international business satellite communications network

    Science.gov (United States)

    Nohara, Mitsuo; Takeuchi, Yoshio; Takahata, Fumio; Hirata, Yasuo

    An experimental system is being developed for use in an international business satellite (IBS) communications network based on demand-assignment (DA) and TDMA techniques. This paper discusses its system design, in particular from the viewpoints of a network configuration, a DA control, and a satellite channel-assignment algorithm. A satellite channel configuration is also presented along with a tradeoff study on transmission rate, HPA output power, satellite resource efficiency, service quality, and so on.

  20. Transactive Control of Commercial Buildings for Demand Response

    Energy Technology Data Exchange (ETDEWEB)

    Hao, He; Corbin, Charles D.; Kalsi, Karanjit; Pratt, Robert G.

    2017-01-01

    Transactive control is a type of distributed control strategy that uses market mechanism to engage self-interested responsive loads to achieve power balance in the electrical power grid. In this paper, we propose a transactive control approach of commercial building Heating, Ventilation, and Air- Conditioning (HVAC) systems for demand response. We first describe the system models, and identify their model parameters using data collected from Systems Engineering Building (SEB) located on our Pacific Northwest National Laboratory (PNNL) campus. We next present a transactive control market structure for commercial building HVAC system, and describe its agent bidding and market clearing strategies. Several case studies are performed in a simulation environment using Building Control Virtual Test Bed (BCVTB) and calibrated SEB EnergyPlus model. We show that the proposed transactive control approach is very effective at peak clipping, load shifting, and strategic conservation for commercial building HVAC systems.

  1. Job Demands-Control-Support model and employee safety performance.

    Science.gov (United States)

    Turner, Nick; Stride, Chris B; Carter, Angela J; McCaughey, Deirdre; Carroll, Anthony E

    2012-03-01

    The aim of this study was to explore whether work characteristics (job demands, job control, social support) comprising Karasek and Theorell's (1990) Job Demands-Control-Support framework predict employee safety performance (safety compliance and safety participation; Neal and Griffin, 2006). We used cross-sectional data of self-reported work characteristics and employee safety performance from 280 healthcare staff (doctors, nurses, and administrative staff) from Emergency Departments of seven hospitals in the United Kingdom. We analyzed these data using a structural equation model that simultaneously regressed safety compliance and safety participation on the main effects of each of the aforementioned work characteristics, their two-way interactions, and the three-way interaction among them, while controlling for demographic, occupational, and organizational characteristics. Social support was positively related to safety compliance, and both job control and the two-way interaction between job control and social support were positively related to safety participation. How work design is related to employee safety performance remains an important area for research and provides insight into how organizations can improve workplace safety. The current findings emphasize the importance of the co-worker in promoting both safety compliance and safety participation. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  2. Worktime demands and work-family interference: Does worktime control buffer the adverse effects of high demands?

    NARCIS (Netherlands)

    Geurts, S.A.E.; Beckers, D.G.J.; Taris, T.W.; Kompier, M.A.J.; Smulders, P.G.W.

    2009-01-01

    This study examined whether worktime control buffered the impact of worktime demands on work-family interference (WFI), using data from 2,377 workers from various sectors of industry in The Netherlands. We distinguished among three types of worktime demands: time spent on work according to one's

  3. Demand Controlled Ventilation in a Combined Ventilation and Radiator System

    OpenAIRE

    Hesaraki, Arefeh; Holmberg, Sture

    2013-01-01

    With growing concerns for efficient and sustainable energy treatment in buildings there is a need for balanced and intelligent ventilation solutions. This paper presents a strategy for demand controlled ventilation with ventilation radiators, a combined heating and ventilation system. The ventilation rate was decreased from normal requirements (per floor area) of 0.375 l·s-1·m-2 to 0.100 l·s-1·m-2 when the residence building was un-occupied. The energy saving potential due to decreased ventil...

  4. Distributed control system for demand response by servers

    Science.gov (United States)

    Hall, Joseph Edward

    Within the broad topical designation of smart grid, research in demand response, or demand-side management, focuses on investigating possibilities for electrically powered devices to adapt their power consumption patterns to better match generation and more efficiently integrate intermittent renewable energy sources, especially wind. Devices such as battery chargers, heating and cooling systems, and computers can be controlled to change the time, duration, and magnitude of their power consumption while still meeting workload constraints such as deadlines and rate of throughput. This thesis presents a system by which a computer server, or multiple servers in a data center, can estimate the power imbalance on the electrical grid and use that information to dynamically change the power consumption as a service to the grid. Implementation on a testbed demonstrates the system with a hypothetical but realistic usage case scenario of an online video streaming service in which there are workloads with deadlines (high-priority) and workloads without deadlines (low-priority). The testbed is implemented with real servers, estimates the power imbalance from the grid frequency with real-time measurements of the live outlet, and uses a distributed, real-time algorithm to dynamically adjust the power consumption of the servers based on the frequency estimate and the throughput of video transcoder workloads. Analysis of the system explains and justifies multiple design choices, compares the significance of the system in relation to similar publications in the literature, and explores the potential impact of the system.

  5. Optimised control and pipe burst detection by water demand forecasting

    NARCIS (Netherlands)

    Bakker, M.

    2014-01-01

    Water demand forecasting The total water demand in an area is the sum of the water demands of all individual domestic and industrial consumers in that area. These consumers behave in repetitive daily, weekly and annual patterns, and the same repetitive patterns can be observed in the drinking water

  6. CO2 MONITORING FOR DEMAND CONTROLLED VENTILATION IN COMMERCIAL BUILDINGS

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.; Sullivan, Douglas P.; Faulkner, David; Eliseeva, Ekaterina

    2010-03-17

    Carbon dioxide (CO{sub 2}) sensors are often deployed in commercial buildings to obtain CO{sub 2} data that are used, in a process called demand-controlled ventilation, to automatically modulate rates of outdoor air ventilation. The objective is to keep ventilation rates at or above design specifications and code requirements and also to save energy by avoiding excessive ventilation rates. Demand controlled ventilation is most often used in spaces with highly variable and sometime dense occupancy. Reasonably accurate CO{sub 2} measurements are needed for successful demand controlled ventilation; however, prior research has suggested substantial measurement errors. Accordingly, this study evaluated: (a) the accuracy of 208 CO{sub 2} single-location sensors located in 34 commercial buildings, (b) the accuracy of four multi-location CO{sub 2} measurement systems that utilize tubing, valves, and pumps to measure at multiple locations with single CO{sub 2} sensors, and (c) the spatial variability of CO{sub 2} concentrations within meeting rooms. The field studies of the accuracy of single-location CO{sub 2} sensors included multi-concentration calibration checks of 90 sensors in which sensor accuracy was checked at multiple CO{sub 2} concentrations using primary standard calibration gases. From these evaluations, average errors were small, -26 ppm and -9 ppm at 760 and 1010 ppm, respectively; however, the averages of the absolute values of error were 118 ppm (16%) and 138 ppm (14%), at concentrations of 760 and 1010 ppm, respectively. The calibration data are generally well fit by a straight line as indicated by high values of R{sup 2}. The Title 24 standard specifies that sensor error must be certified as no greater than 75 ppm for a period of five years after sensor installation. At 1010 ppm, 40% of sensors had errors greater than {+-}75 ppm and 31% of sensors has errors greater than {+-}100 ppm. At 760 ppm, 47% of sensors had errors greater than {+-}75 ppm and 37% of

  7. A predictive control scheme for automated demand response mechanisms

    NARCIS (Netherlands)

    Lampropoulos, I.; Bosch, van den P.P.J.; Kling, W.L.

    2012-01-01

    The development of demand response mechanisms can provide a considerable option for the integration of renewable energy sources and the establishment of efficient generation and delivery of electrical power. The full potential of demand response can be significant, but its exploration still remains

  8. Measuring and controlling unfairness in decentralized planning of energy demand

    NARCIS (Netherlands)

    Pournaras, E.; Vasirani, M.; Kooij, R.E.; Aberer, K.

    2014-01-01

    Demand-side energy management improves robustness and efficiency in Smart Grids. Load-adjustment and load-shifting are performed to match demand to available supply. These operations come at a discomfort cost for consumers as their lifestyle is influenced when they adjust or shift in time their

  9. Islanding Control Architecture in future smart grid with both demand and wind turbine control

    DEFF Research Database (Denmark)

    Chen, Yu; Xu, Zhao; Østergaard, Jacob

    2013-01-01

    , which is the focus of this paper, available resources including both DG units and demand should be fully utilized as reserves. The control and coordination among different resources requires an integral architecture to serve the purpose. This paper develops the Islanding Control Architecture (ICA...

  10. Reward-driven modulation of adaptive control: How prospective monetary gains interact with unpredictable control demands

    NARCIS (Netherlands)

    Marien, Hans; Aarts, Henk; Custers, Ruud

    2014-01-01

    Shifting attention is an effortful control process and incurs a cost on the cognitive system. Previous research suggests that rewards, such as monetary gains, will selectively enhance the ability to shift attention when this demand for control is explicitly cued. Here, we hypothesized that

  11. Modeling, Analysis, and Control of Demand Response Resources

    Energy Technology Data Exchange (ETDEWEB)

    Mathieu, Johanna L. [Univ. of California, Berkeley, CA (United States)

    2012-05-01

    While the traditional goal of an electric power system has been to control supply to fulfill demand, the demand-side can plan an active role in power systems via Demand Response (DR), defined by the Department of Energy (DOE) as “a tariff or program established to motivate changes in electric use by end-use customers in response to changes in the price of electricity over time, or to give incentive payments designed to induce lower electricity use at times of high market prices or when grid reliability is jeopardized” [29]. DR can provide a variety of benefits including reducing peak electric loads when the power system is stressed and fast timescale energy balancing. Therefore, DR can improve grid reliability and reduce wholesale energy prices and their volatility. This dissertation focuses on analyzing both recent and emerging DR paradigms. Recent DR programs have focused on peak load reduction in commercial buildings and industrial facilities (C&I facilities). We present methods for using 15-minute-interval electric load data, commonly available from C&I facilities, to help building managers understand building energy consumption and ‘ask the right questions’ to discover opportunities for DR. Additionally, we present a regression-based model of whole building electric load, i.e., a baseline model, which allows us to quantify DR performance. We use this baseline model to understand the performance of 38 C&I facilities participating in an automated dynamic pricing DR program in California. In this program, facilities are expected to exhibit the same response each DR event. We find that baseline model error makes it difficult to precisely quantify changes in electricity consumption and understand if C&I facilities exhibit event-to-event variability in their response to DR signals. Therefore, we present a method to compute baseline model error and a metric to determine how much observed DR variability results from baseline model error rather than real

  12. Access control for on-demand provisioned cloud infrastructure services

    NARCIS (Netherlands)

    Ngo, C.T.

    2016-01-01

    The evolution of Cloud Computing brings advantages to both customers and service providers to utilize and manage computing and network resources more efficiently with virtualization, service-oriented architecture technologies, and automated on-demand resource provisioning. However, these advantages

  13. Wind Farm Dispatch Control for Demand Tracking and Minimized Fatigue

    DEFF Research Database (Denmark)

    Juelsgaard, Morten; Schiøler, Henrik; Leth, John-Josef

    2012-01-01

    This work presents a strategy for dispatching production references to the individual turbines in a wind farm, such that an overall production demand for the farm is obeyed, while the fatigue experienced by the turbines is minimized. Using a turbine fatigue model for simulating the aging across...... the farm, we show that a 17 % reduction of the turbine aging can be obtained compared to a commonly employed industrial dispatcher, without degrading the power demand tracking....

  14. Control for large scale demand response of thermostatic loads

    DEFF Research Database (Denmark)

    Totu, Luminita Cristiana; Leth, John; Wisniewski, Rafal

    2013-01-01

    appliances with on/off operation. The objective is to reduce the consumption peak of a group of loads composed of both flexible and inflexible units. The power flexible units are the thermostat-based appliances. We discuss a centralized, model predictive approach and a distributed structure with a randomized......Demand response is an important Smart Grid concept that aims at facilitating the integration of volatile energy resources into the electricity grid. This paper considers a residential demand response scenario and specifically looks into the problem of managing a large number thermostatbased...

  15. Railing for safety: job demands, job control, and safety citizenship role definition.

    Science.gov (United States)

    Turner, Nick; Chmiel, Nik; Walls, Melanie

    2005-10-01

    This study investigated job demands and job control as predictors of safety citizenship role definition, that is, employees' role orientation toward improving workplace safety. Data from a survey of 334 trackside workers were framed in the context of R. A. Karasek's (1979) job demands-control model. High job demands were negatively related to safety citizenship role definition, whereas high job control was positively related to this construct. Safety citizenship role definition of employees with high job control was buffered from the influence of high job demands, unlike that of employees with low job control, for whom high job demands were related to lower levels of the construct. Employees facing both high job demands and low job control were less likely than other employees to view improving safety as part of their role orientation. Copyright (c) 2005 APA, all rights reserved.

  16. Primary Control by ON/OFF Demand-Side Devices

    DEFF Research Database (Denmark)

    Biegel, Benjamin; Hansen, Lars Henrik; Andersen, Palle

    2013-01-01

    We consider an aggregator managing a portfolio of ON/OFF demand-side devices. The devices are able to shift con- sumption in time within certain energy limitations; moreover, the devices are able to measure the system frequency and switch ON and OFF accordingly. We show how the aggregator can...

  17. Gaze control during interceptive actions with different spatiotemporal demands.

    NARCIS (Netherlands)

    Navia, J.A.; Dicks, M.S.; van der Kamp, J; Ruiz, L.

    It is widely accepted that the sources of information used to guide interceptive actions depend on conflicting spatiotemporal task demands. However, there is a paucity of evidence that shows how information pick-up during interceptive actions is adapted to such conflicting constraints. The present

  18. Distributed MPC applied to power demand side control

    NARCIS (Netherlands)

    Larsen, G.K.H.; Pons, J.; Achterop, S.; Scherpen, J.M.A.

    2013-01-01

    In the future, global energy balance of a smart grid system can be achieved by its agents deciding on their own power demand locally and the exchange of these decisions. In this paper, we model a network of households with washing machine programs that can be shifted in time so that the overall

  19. Demand-Side Contribution to Primary Frequency Control With Wind Farm Auxiliary Control

    DEFF Research Database (Denmark)

    Gomez-Lazaro, Emilio; Munoz-Benavente, Irene; Hansen, Anca Daniela

    2014-01-01

    Maintaining a close balance between power generation and demand is essential for sustaining the quality and reliability of a power system. Currently, due to increased renewable energy generation, frequency deviations and power fluctuations of greater concern are being introduced to the grid...... to the primary frequency control together with an auxiliary frequency control, which is carried out by variable-speed wind turbines through an additional control loop that synthesizes virtual inertia. We have evaluated both the suitability of these two additional control actions counteracting frequency deviation...

  20. Psychological demand and control of the work process of public university servants.

    Science.gov (United States)

    Moura, Denise Cristina Alves de; Greco, Rosangela Maria; Paschoalin, Heloisa Campos; Portela, Luciana Fernandes; Arreguy-Sena, Cristina; Chaoubah, Alfredo

    2018-02-01

    This cross-sectional research aimed to analyze the psychological demand and work control self-reported by the Education Administrative Technicians of a public university. This is a complete sample selection consisting of 833 Education Administrative Technicians who self-completed a questionnaire with questions structured in 2013/2014. A descriptive bivariate analysis was performed with the calculation of psychosocial stress at work, using the Demand-Control Model quadrants categorized as: low-demand work (low-demand and high-control), reference group, passive work (low-demand and low-control), active work (high-demand and high-control), high-demand (high-demand and low-control) - group with the highest exposure. The study complies with all ethical and legal research requirements involving human beings. There was a predominance of the category of workers performing passive work (n = 319, 39.7%), low work demand (n = 274, 34.1%), high work demand (n = 116, 14.4%) and active work (n = 95, 11.8%). There were contributions from the investigation on the health of these workers insofar as they provided a diagnosis of the category. There is a recommendation for such data to support interventions to empower them and retailor jobs.

  1. Predictive Control of Demand Side Units Participating in the Primary Frequency Reserve Market

    DEFF Research Database (Denmark)

    Biegel, Benjamin; Stoustrup, Jakob; Andersen, Palle

    2013-01-01

    We consider an aggregator controlling a mixed portfolio of conventional power generators and demand side units. The generators are controllable within certain power and ramp limitations while the demand side units are characterized by flexible consumptions and therefore can be treated as energy...

  2. Psychosocial work environment and health in U.S. metropolitan areas: a test of the demand-control and demand-control-support models.

    Science.gov (United States)

    Muntaner, C; Schoenbach, C

    1994-01-01

    The authors use confirmatory factor analysis to investigate the psychosocial dimensions of work environments relevant to health outcomes, in a representative sample of five U.S. metropolitan areas. Through an aggregated inference system, scales from Schwartz and associates' job scoring system and from the Dictionary of Occupational Titles (DOT) were employed to examine two alternative models: the demand-control model of Karasek and Theorell and Johnson's demand-control-support model. Confirmatory factor analysis was used to test the two models. The two multidimensional models yielded better fits than an unstructured model. After allowing for the measurement error variance due to the method of assessment (Schwartz and associates' system or DOT), both models yielded acceptable goodness-of-fit indices, but the fit of the demand-control-support model was significantly better. Overall these results indicate that the dimensions of Control (substantive complexity of work, skill discretion, decision authority), Demands (physical exertion, physical demands and hazards), and Social Support (coworker and supervisor social supports) provide an acceptable account of the psychosocial dimensions of work associated with health outcomes.

  3. Influence of job demands and job control on work-life balance among Taiwanese nurses.

    Science.gov (United States)

    Ng, Lee-Peng; Chen, I-Chi; Ng, Hui-Fuang; Lin, Bo-Yen; Kuar, Lok-Sin

    2017-09-01

    This study investigated the extent to which the job demands and job control of nurses were related to their work-life balance. The inability to achieve work-life balance is one of the major reasons for the declining retention rate among nurses. Job demands and job control are two major work domain factors that can have a significant influence on the work-life balance of nurses. The study measured the job demands, job control and work-life balance of 2040 nurses in eight private hospitals in Taiwan in 2013. Job demands and job control significantly predicted all the dimensions of work-life balance. Job demands increased the level of work-life imbalance among nurses. While job control showed positive effects on work/personal life enhancement, it was found to increase both work interference with personal life and personal life interference with work. Reducing the level of job demands (particularly for psychological demands) between family and career development and maintaining a proper level of job control are essential to the work-life balance of nurses. Flexible work practices and team-based management could be considered by nursing management to lessen job demand pressure and to facilitate job engagement and participation among nurses, thus promoting a better balance between work and personal life. © 2017 John Wiley & Sons Ltd.

  4. Neural network controller for Active Demand-Side Management with PV energy in the residential sector

    International Nuclear Information System (INIS)

    Matallanas, E.; Castillo-Cagigal, M.; Gutiérrez, A.; Monasterio-Huelin, F.; Caamaño-Martín, E.; Masa, D.; Jiménez-Leube, J.

    2012-01-01

    Highlights: ► We have developed a neural controller for Active Demand-Side Management. ► The controller consists of Multilayer Perceptrons evolved with a genetic algorithm. ► The architecture of the controller is distributed and modular. ► The simulations show that the electrical local behavior improves. ► Active Demand-Side Management helps users to control his energy behaviour. -- Abstract: In this paper, we describe the development of a control system for Demand-Side Management in the residential sector with Distributed Generation. The electrical system under study incorporates local PV energy generation, an electricity storage system, connection to the grid and a home automation system. The distributed control system is composed of two modules: a scheduler and a coordinator, both implemented with neural networks. The control system enhances the local energy performance, scheduling the tasks demanded by the user and maximizing the use of local generation.

  5. A supervisory approach to microgrid demand response and climate control

    NARCIS (Netherlands)

    Korkas, Christos D.; Baldi, S.; Michailidis, Iakovos; Boutalis, Yiannis; Kosmatopoulos, Elias B.; Antsaklis, Panos J.; Valavanis, Kimon P.; Theiliol, Didier

    2016-01-01

    Microgrids equipped with small-scale renewable-energy generation systems and energy storage units offer challenging opportunity from a control point of view. In fact, in order to improve resilience and enable islanded mode, micro-grid energy management systems must dynamically manage controllable

  6. Hierarchical Control Architecture for Demand Response in Smart Grid Scenario

    DEFF Research Database (Denmark)

    Bhattarai, Bishnu Prasad; Bak-Jensen, Birgitte; Mahat, Pukar

    2013-01-01

    , a number of issues, including DR enabling technologies, control strategy, and control architecture, are still under discussion. This paper outlines novel control requirements based on the categorization of existing DR techniques. More specifically, the roles and responsibilities of smart grid actors...... effective tool for optimum asset utilization and to avoid or delay the need for new infrastructure investment. Furthermore, most of the power networks are under the process of reconfiguration to realize the concept of smart grid and are at the transforming stage to support various forms of DR. However...... for every DR category are allotted and their mode of interactions to coordinate individual as well as coordinative goals is described. Next, hierarchical control architecture (HCA) is developed for the overall coordination of control strategies for individual DR categories. The involved issues are discussed...

  7. The active learning hypothesis of the job-demand-control model: an experimental examination.

    Science.gov (United States)

    Häusser, Jan Alexander; Schulz-Hardt, Stefan; Mojzisch, Andreas

    2014-01-01

    The active learning hypothesis of the job-demand-control model [Karasek, R. A. 1979. "Job Demands, Job Decision Latitude, and Mental Strain: Implications for Job Redesign." Administration Science Quarterly 24: 285-307] proposes positive effects of high job demands and high job control on performance. We conducted a 2 (demands: high vs. low) × 2 (control: high vs. low) experimental office workplace simulation to examine this hypothesis. Since performance during a work simulation is confounded by the boundaries of the demands and control manipulations (e.g. time limits), we used a post-test, in which participants continued working at their task, but without any manipulation of demands and control. This post-test allowed for examining active learning (transfer) effects in an unconfounded fashion. Our results revealed that high demands had a positive effect on quantitative performance, without affecting task accuracy. In contrast, high control resulted in a speed-accuracy tradeoff, that is participants in the high control conditions worked slower but with greater accuracy than participants in the low control conditions.

  8. Presenting automatic demand control (ADC) as a new frequency control method in smart grids

    Energy Technology Data Exchange (ETDEWEB)

    Ameli, Mohammad Taghi; Ameli, Ali; Maleki, Hamed [Power and Water Univ. of Technology, Tehran (Iran, Islamic Republic of); Mobarhani, Alireza [Amir Kabir Univ. of Technology, Tehran (Iran, Islamic Republic of)

    2011-07-01

    Electric power is the most important part of human energy consumption, and since it has a low storage coefficient it is of particular importance to establish a balance in demand and generation in order to modify and optimize consumption patterns. The expression ''Smart Grid'' can be used to describe technologies which are applied for the automation and optimization of the generation, transmission and distribution network management. This technology requires the integration of information and communication technology in electrical network operation. This paper will study how the Smart Grid capabilites can be used to manage and optimize power network consumption, as well as how the consumers collaboration process using an AGC (Automatic Generation Control) system acts to provide secondary frequency control through consumed load shedding. Reestablishing the balance between demand and generation in critical network operation is also investigated. In other words, utilizing the above method, a new system, ADC (Automatic Demand Control), is offered for use alongside the AGC system in Smart Grids to restore the frequency value to its nominal value. This can lead to a more competitive electricity market and reduce the system storage while maintaining adequate security and network reliability. One of the benefits of the proposed methods described in this paper, in addition to restoring the frequency value to its nominal value, is lower costs and a more economic network operation through reducing fuel and CO2 emission by managing and controlling the amount of the consumed load in the Smart Grid. Also consumers are given the capability to have a specific timetable to economize on their energy requirements which will also reduce the load peak and the network losses. (orig.)

  9. Aggregate modeling of fast-acting demand response and control under real-time pricing

    International Nuclear Information System (INIS)

    Chassin, David P.; Rondeau, Daniel

    2016-01-01

    Highlights: • Demand elasticity for fast-acting demand response load under real-time pricing. • Validated first-principles logistic demand curve matches random utility model. • Logistic demand curve suitable for diversified aggregate loads market-based transactive control systems. - Abstract: This paper develops and assesses the performance of a short-term demand response (DR) model for utility load control with applications to resource planning and control design. Long term response models tend to underestimate short-term demand response when induced by prices. This has two important consequences. First, planning studies tend to undervalue DR and often overlook its benefits in utility demand management program development. Second, when DR is not overlooked, the open-loop DR control gain estimate may be too low. This can result in overuse of load resources, control instability and excessive price volatility. Our objective is therefore to develop a more accurate and better performing short-term demand response model. We construct the model from first principles about the nature of thermostatic load control and show that the resulting formulation corresponds exactly to the Random Utility Model employed in economics to study consumer choice. The model is tested against empirical data collected from field demonstration projects and is shown to perform better than alternative models commonly used to forecast demand in normal operating conditions. The results suggest that (1) existing utility tariffs appear to be inadequate to incentivize demand response, particularly in the presence of high renewables, and (2) existing load control systems run the risk of becoming unstable if utilities close the loop on real-time prices.

  10. Application of Demand-Control Theory to Sign Language Interpreting: Implications for Stress and Interpreter Training.

    Science.gov (United States)

    Dean, Robyn K.; Pollard, Robert Q., Jr.

    2001-01-01

    This article uses the framework of demand-control theory to examine the occupation of sign language interpreting. It discusses the environmental, interpersonal, and intrapersonal demands that impinge on the interpreter's decision latitude and notes the prevalence of cumulative trauma disorders, turnover, and burnout in the interpreting profession.…

  11. Conceptual framework for load controlling : with demand reduction bidding & consumer retention

    NARCIS (Netherlands)

    Babar, M.; Ahamed, I.; Al-Ammar, E.A.

    2013-01-01

    Advancement in demand side management strategies enables smart grid to cope with the increasing energy demand and provide economic benefit to all of its stakeholders. Moreover, emerging concept of smart pricing and advances in load control and communication generate new business opportunities as a

  12. Testing the strain hypothesis of the Demand Control Model to explain severe bullying at work

    NARCIS (Netherlands)

    Notelaers, G.; Baillien, E.; de Witte, H.; Einarsen, S.; Vermunt, J.K.

    2013-01-01

    Workplace bullying has often been attributed to work-related stress, and has been linked to the Job Demand Control Model. The current study aims to further these studies by testing the model for bullying in a heterogeneous sample and by using latent class (LC)-analyses to define different demands

  13. Worktime demands and work-family interference: Does worktime control play a buffering role

    NARCIS (Netherlands)

    Geurts, S.A.E.; Beckers, D.G.J.; Taris, T.W.; Kompier, M.A.J.; Smulders, P.G.W.

    2009-01-01

    This study examined whether worktime control buffered the impact of worktime demands on work–family interference (WFI), using data from 2,377 workers from various sectors of industry in The Netherlands. We distinguished among three types of worktime demands: time spent on work according to one’s

  14. Attention Demand and Postural Control in Children with Hearing Deficit

    Science.gov (United States)

    Derlich, Malgorzata; Krecisz, Krzysztof; Kuczynski, Michal

    2011-01-01

    To elucidate the mechanisms responsible for deteriorated postural control in children with hearing deficit (CwHD), we measured center-of-pressure (COP) variability, mean velocity and entropy in bipedal quiet stance (feet together) with or without the concurrent cognitive task (reaction to visual stimulus) on hard or foam surface in 29 CwHD and a…

  15. An Auto Tuning Substation Peak Shaving Controller for Congestion Management Using Flexible Demand

    DEFF Research Database (Denmark)

    Sossan, Fabrizio; Marinelli, Mattia

    2013-01-01

    A closed loop substation peak shaving/congestion management controller for radial distribution networks is presented. The controller it uses an individual control signal in order to shift the consumption of a population of demand side resources, DSRs. The controller auto tunes its parameters on...

  16. Job stress, fatigue, and job dissatisfaction in Dutch lorry drivers: towards an occupation specific model of job demands and control

    NARCIS (Netherlands)

    de Croon, E. M.; Blonk, R. W. B.; de Zwart, B. C. H.; Frings-Dresen, M. H. W.; Broersen, J. P. J.

    2002-01-01

    Objectives: Building on Karasek's model of job demands and control (JD-C model), this study examined the effects of job control, quantitative workload, and two occupation specific job demands (physical demands and supervisor demands) on fatigue and job dissatisfaction in Dutch lorry drivers.

  17. A Relook at the National Drug Control Strategy: Supply versus Demand

    National Research Council Canada - National Science Library

    Cook, Virgil

    1998-01-01

    .... By reviewing the ends, ways, and means of past drug control strategies, this paper suggests that it is time for the federal government to shift existing resources from supply reduction to demand reduction programs...

  18. Understanding well-being and learning of Nigerian nurses: a job demand control support model approach.

    Science.gov (United States)

    van Doorn, Yvonne; van Ruysseveldt, Joris; van Dam, Karen; Mistiaen, Wilhelm; Nikolova, Irina

    2016-10-01

    This study investigated whether Nigerian nurses' emotional exhaustion and active learning were predicted by job demands, control and social support. Limited research has been conducted concerning nurses' work stress in developing countries, such as Nigeria. Accordingly, it is not clear whether work interventions for improving nurses' well-being in these countries can be based on work stress models that are developed in Western countries, such as the job demand control support model, as well as on empirical findings of job demand control support research. Nurses from Nurses Across the Borders Nigeria were invited to complete an online questionnaire containing validated scales; 210 questionnaires were fully completed and analysed. Multiple regression analysis was used to test the hypotheses. Emotional exhaustion was higher for nurses who experienced high demands and low supervisor support. Active learning occurred when nurses worked under conditions of high control and high supervisor support. The findings suggest that the job demand control support model is applicable in a Nigerian nursing situation; the model indicates which occupational stressors contribute to poor well-being in Nigerian nurses and which work characteristics may boost nurses' active learning. Job (re)design interventions can enhance nurses' well-being and learning by guarding nurses' job demands, and stimulating job control and supervisor support. © 2016 John Wiley & Sons Ltd.

  19. Family nursing hospital training and the outcome on job demands, control and support.

    Science.gov (United States)

    Sigurdardottir, Anna Olafia; Svavarsdottir, Erla Kolbrun; Juliusdottir, Sigrun

    2015-07-01

    The purpose of this study was to evaluate the impact of a family systems nursing hospital training educational program (ETI program) on nurses' and midwives' perception of job demands, control, and/or support. Of the nurses and midwives who were working in the Women's and Children's Services Division at The National University Hospital in Iceland, 479 participated in the study on three time periods from 2009 to 2011. Scores for the characteristics of job demands and job control were created to categorize participants into four job types (Karasek and Theorell, 1990). These four job types are high strain (high demand, low control), passive (low demand, low control), low strain (low demand, high control), and active (high demand, high control). However, when the data were evaluated based on the proportion of job characteristics as reported by the nurses and the midwives, no significant difference was found over time (2009 to 2011) (χ(2)=5.203, p=.518). However, based on the results from the independent t-tests at time 1, a significant difference was found amongst the high strain job group regarding perceived support from administrators and colleagues among the nurses and midwives who had taken the ETI program compared to those who had not taken the program (χ(2)=2.218, p=.034). This indicates that the health care professionals who characterized their job to be of high demand but with low control evaluated the support from their administrators and colleagues to be significantly higher if they had taken the ETI program than did the nurses and midwives who did not take the ETI program. These findings are promising because they might, in the long run, increase the nurses' and midwives' autonomy and control over their own work. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Demanda por grupos, psicologia e controle Group demand, psychology and control

    Directory of Open Access Journals (Sweden)

    Abrahão de Oliveira Santos

    2011-08-01

    Full Text Available Este artigo traz uma reflexão sobre uma capacitação para o trabalho grupal, destinado às equipes das UBSs (Unidades Básica de Saúde do SUS (Sistema Único de Saúde e agentes comunitários de saúde de um município do interior do Estado de São Paulo. Trata-se de analisar o pedido explicitado pela equipe, de mostrar a reflexão a respeito desse pedido, as circunstâncias dos problemas colocados, a experiência dos vários trabalhadores da equipe e a escuta do que se passa do lado da população. Parar para ouvir os parceiros do trabalho e refletir sobre a intervenção fez a equipe trabalhar sua sensibilidade diante das questões da população, do que vem a ser saúde e poder assumir outra postura que não seja a de servir ao controle da população e trabalhar para a construção da sociedade de controle.This article brings a reflection about a training for group work developed with UBSs (Basic Units of Health technical staff from SUS (Unified System of Health and agents of health from a county in the State of São Paulo, Brazil. The procedure involves: (1 to analyze the explicit demand form the crew, (2 to show a reflection about this demand, (3 to show the context of the problems, (4 to consider the experience of workers on the crew, and (5 to listen to what happens from population's standpoint. Stop listening to the job partners and reflecting about the intervention made the crew work.

  1. The Effect of the Demand Control and Effort Reward Imbalance Models on the Academic Burnout of Korean Adolescents

    Science.gov (United States)

    Lee, Jayoung; Puig, Ana; Lee, Sang Min

    2012-01-01

    The purpose of this study was to examine the effects of the Demand Control Model (DCM) and the Effort Reward Imbalance Model (ERIM) on academic burnout for Korean students. Specifically, this study identified the effects of the predictor variables based on DCM and ERIM (i.e., demand, control, effort, reward, Demand Control Ratio, Effort Reward…

  2. Value congruence, control, sense of community and demands as determinants of burnout syndrome among hospitality workers.

    Science.gov (United States)

    Asensio-Martínez, Ángela; Leiter, Michael P; Gascón, Santiago; Gumuchian, Stephanie; Masluk, Bárbara; Herrera-Mercadal, Paola; Albesa, Agustín; García-Campayo, Javier

    2017-09-07

    Employees working in the hospitality industry are constantly exposed to occupational stressors that may lead employees into experiencing burnout syndrome. Research addressing the interactive effects of control, community and value congruence to alleviate the impact of workplace demands on experiencing burnout is relatively limited. The present study examined relationships among control, community and value congruence, workplace demands and the three components of burnout. A sample of 418 employees working in a variety of hospitality associations including restaurants and hotels in Spain were recruited. Moderation analyses and linear regressions analyzed the predictive power of control, community and value congruence as moderating variables. Results indicate that control, community and value congruence were successful buffers in the relationships between workplace demands and the burnout dimensions. The present findings offer suggestions for future research on potential moderating variables, as well as implications for reducing burnout among hospitality employees.

  3. Effects of dynamic-demand-control appliances on the power grid frequency

    Science.gov (United States)

    Tchuisseu, E. B. Tchawou; Gomila, D.; Brunner, D.; Colet, P.

    2017-08-01

    Power grid frequency control is a demanding task requiring expensive idle power plants to adapt the supply to the fluctuating demand. An alternative approach is controlling the demand side in such a way that certain appliances modify their operation to adapt to the power availability. This is especially important to achieve a high penetration of renewable energy sources. A number of methods to manage the demand side have been proposed. In this work we focus on dynamic demand control (DDC), where smart appliances can delay their switchings depending on the frequency of the system. We introduce a simple model to study the effects of DDC on the frequency of the power grid. The model includes the power plant equations, a stochastic model for the demand that reproduces, adjusting a single parameter, the statistical properties of frequency fluctuations measured experimentally, and a generic DDC protocol. We find that DDC can reduce small and medium-size fluctuations but it can also increase the probability of observing large frequency peaks due to the necessity of recovering pending task. We also conclude that a deployment of DDC around 30-40% already allows a significant reduction of the fluctuations while keeping the number of pending tasks low.

  4. Information and Communications Systems for Control-by-Price of Distributed Energy Resources and Flexible Demand

    OpenAIRE

    Nyeng, Preben; Østergaard, Jacob

    2011-01-01

    The control-by-price concept fits well with controlling small-scale generation, storage and demand. In this paper, we investigate the required information and communications systems that are needed to realize the control-by-price concept for such units. We first present a proposal for overall infrastructure and subsystem design and secondly focus on the design and implementation of the end-user price-responsive controller, interfaces, and communications. The design and its applicability on ex...

  5. Design and control of precision drop-on-demand herbicide application in agricultural robotics

    OpenAIRE

    Urdal, Frode; Utstumo, Trygve; Vatne, Jan Kåre; Ellingsen, Simen Andreas Ådnøy; Gravdahl, Jan Tommy

    2014-01-01

    This is the author’s final, accepted and refereed manuscript to the article. Drop-on-demand weed control is a field of research within Precision Agriculture, where the herbicide application is controlled down to individual droplets. This paper focuses on the fluid dynamics and electronics design of the droplet dispensing. The droplets are formed through an array of nozzles, controlled by two-way solenoid valves. A much used control circuit for opening and closing a soleno...

  6. An Experience Sampling Study of Learning, Affect, and the Demands Control Support Model

    Science.gov (United States)

    Daniels, Kevin; Boocock, Grahame; Glover, Jane; Hartley, Ruth; Holland, Julie

    2009-01-01

    The demands control support model (R. A. Karasek & T. Theorell, 1990) indicates that job control and social support enable workers to engage in problem solving. In turn, problem solving is thought to influence learning and well-being (e.g., anxious affect, activated pleasant affect). Two samples (N = 78, N = 106) provided data up to 4 times per…

  7. A predictive control scheme for real-time demand response applications

    NARCIS (Netherlands)

    Lampropoulos, I.; Baghina, N.G.; Kling, W.L.; Ribeiro, P.F.

    2013-01-01

    In this work, the focus is placed on the proof of concept of a novel control scheme for demand response. The control architecture considers a uniform representation of non-homogeneous distributed energy resources and allows the participation of virtually all system users in electricity markets. The

  8. Impact of California air quality control policies on the use and demand for natural gas

    International Nuclear Information System (INIS)

    Boyd, J.D.

    1992-01-01

    This paper discusses the impact of California's air quality control policies on the use of natural gas. In this paper the author would like to briefly review the regulatory structure for air pollution control in California, summarize the requirement of the California Clean Air Act of 1988, and discuss the impacts of our regulatory programs on the use and demand for natural gas

  9. Management and control of the electrical energy demand; Administracion y control de la demanda de la energia electrica

    Energy Technology Data Exchange (ETDEWEB)

    Johnson Controls [Comision Federal de Electricidad (Mexico)

    2005-07-01

    Administrative measures allow a reduction in the energy consumption, but not always in the electrical demand. Control measures allow a reduction in the billing of the electrical demand, but not always in the energy consumption. This is why it is explained in this document what management and control of the electrical demand is, as well as its control strategies, the control alternatives, the billing demand and at the same time graphical representations along with three practical cases on the management of demand in air compressors, air conditioning equipment and in corporative buildings are presented. [Spanish] La aplicacion de las medidas administrativas permite reducir el consumo de energia, pero no siempre la demanda electrica. La aplicacion de medidas de control permiten reducir la demanda electrica facturable, pero no siempre el consumo de energia. Es por eso que en este documento se explica que es la administracion y el control de la demanda electrica, sus estrategias de control, las alternativas de control, la demanda facturable, representaciones graficas y tres casos practicos sobre la administracion de demanda en compresores de aire, la administracion de demanda en aire acondicionado y la administracion de demanda en un edificio corporativo.

  10. Effects of externally rated job demand and control on depression diagnosis claims in an industrial cohort.

    Science.gov (United States)

    DeSanto Iennaco, Joanne; Cullen, Mark R; Cantley, Linda; Slade, Martin D; Fiellin, Martha; Kasl, Stanislav V

    2010-02-01

    This study examined whether externally rated job demand and control were associated with depression diagnosis claims in a heavy industrial cohort. The retrospective cohort sample consisted of 7,566 hourly workers aged 18-64 years who were actively employed at 11 US plants between January 1, 1996, and December 31, 2003, and free of depression diagnosis claims during an initial 2-year run-in period. Logistic regression analysis was used to model the effect of tertiles of demand and control exposure on depression diagnosis claims. Demand had a significant positive association with depression diagnosis claims in bivariate models and models adjusted for demographic (age, gender, race, education, job grade, tenure) and lifestyle (smoking status, body mass index, cholesterol level) variables (high demand odds ratio = 1.39, 95% confidence interval: 1.04, 1.86). Control was associated with greater risk of depression diagnosis at moderate levels in unadjusted models only (odds ratio = 1.47, 95% confidence interval: 1.12, 1.93), while low control, contrary to expectation, was not associated with depression. The effects of the externally rated demand exposure were lost with adjustment for location. This may reflect differences in measurement or classification of exposure, differences in depression diagnosis by location, or other location-specific factors.

  11. Job demands and decision control predicted return to work: the rapid-RTW cohort study

    Directory of Open Access Journals (Sweden)

    Lise Aasen Haveraaen

    2017-02-01

    Full Text Available Abstract Background In order to help workers with long-term sickness absence return to work (RTW, it is important to understand factors that either impede or facilitate employee’s reintegration into the labour force. The aim of this study was therefore to examine the impact of psychological work characteristics on time-to first RTW in sick listed employees in Norway. Methods The study was designed as a cohort study of 543 employees participating in 50 different RTW programmes. The Job Content Questionnaire (JCQ was used to gather information on the psychological work conditions. The participants were followed for up to 18 months after they started treatment in the RTW programme. Survival analyses were used to investigate the association between psychological work conditions and time-to first RTW. Results Having high psychological job demands (HR = .654; 95% CI: .513–.832 and low decision control (HR = 1.297; 95% CI: 1.010–1.666 were both independent predictors of delayed RTW. Employees in low-strain jobs (low demands/high control (HR = 1.811; 95% CI: 1.287–2.549 and passive jobs (low demands/low control (HR = 1.599; 95% CI: 1.107–2.309, returned to work earlier compared to employees in high-strain jobs (high demands/low control. No difference was found for active jobs (high demands/high control. Conclusion This study revealed that high psychological demands, low control, and being in a high strain job reduced the probability of early RTW in sick listed employees. RTW programmes should therefore increase the focus on these issues.

  12. Job demands and decision control predicted return to work: the rapid-RTW cohort study.

    Science.gov (United States)

    Haveraaen, Lise Aasen; Skarpaas, Lisebet Skeie; Aas, Randi Wågø

    2017-02-02

    In order to help workers with long-term sickness absence return to work (RTW), it is important to understand factors that either impede or facilitate employee's reintegration into the labour force. The aim of this study was therefore to examine the impact of psychological work characteristics on time-to first RTW in sick listed employees in Norway. The study was designed as a cohort study of 543 employees participating in 50 different RTW programmes. The Job Content Questionnaire (JCQ) was used to gather information on the psychological work conditions. The participants were followed for up to 18 months after they started treatment in the RTW programme. Survival analyses were used to investigate the association between psychological work conditions and time-to first RTW. Having high psychological job demands (HR = .654; 95% CI: .513-.832) and low decision control (HR = 1.297; 95% CI: 1.010-1.666) were both independent predictors of delayed RTW. Employees in low-strain jobs (low demands/high control) (HR = 1.811; 95% CI: 1.287-2.549) and passive jobs (low demands/low control) (HR = 1.599; 95% CI: 1.107-2.309), returned to work earlier compared to employees in high-strain jobs (high demands/low control). No difference was found for active jobs (high demands/high control). This study revealed that high psychological demands, low control, and being in a high strain job reduced the probability of early RTW in sick listed employees. RTW programmes should therefore increase the focus on these issues.

  13. Overvoltage Mitigation Using Coordinated Control of Demand Response and Grid-tied Photovoltaics

    DEFF Research Database (Denmark)

    Bhattarai, Bishnu Prasad; Bak-Jensen, Birgitte; Pillai, Jayakrishnan Radhakrishna

    2015-01-01

    Overvoltages in low voltage distribution grids with high solar photovoltaic (PV) integration are usually alleviated by implementing various active/reactive power control techniques. As those methods create revenue loss or inverter cost increase to PV owners, a coordinated control of load demand...... and the PVs, considering electric vehicles (EVs) as potential demand response resource, is proposed in this study to alleviate the overvoltages. A two-stage control is designed to comprehend the proposed coordinated control such that a centralized stage periodically determines optimum operating set......-points for PVs/EVs and a decentralized stage adaptively control the PVs/EVs in real-time. To demonstrate effectiveness of the proposed approach, simulations are performed in a typical 0.4 kV/400 kVA Danish distribution network containing 45 detached residential consumers. The presented method demonstrates better...

  14. Smart Demand for Improving Short-term Voltage Control on Distribution Networks

    DEFF Research Database (Denmark)

    Garcia-Valle, Rodrigo; P. Da Silva, Luiz C.; Xu, Zhao

    2009-01-01

    customer integration to aid power system performance is almost inevitable. This study introduces a new type of smart demand side technology, denoted demand as voltage controlled reserve (DVR), to improve short-term voltage control, where customers are expected to play a more dynamic role to improve voltage...... control. The technology can be provided by thermostatically controlled loads as well as other types of load. This technology is proven to be effective in case of distribution systems with a large composition of induction motors, where the voltage presents a slow recovery characteristic due to deceleration...... of the motors during faults. This study presents detailed models, discussion and simulation tests to demonstrate the technical viability and effectiveness of the DVR technology for short-term voltage control....

  15. An inventory control project in a major Danish company using compound renewal demand models

    DEFF Research Database (Denmark)

    Larsen, Christian; Seiding, Claus Hoe; Teller, Christian

    2008-01-01

    procedures for determining suitable inventory control variables based on the fitted demand distributions and a service-level requirement stated in terms of an order fill rate. Finally, we validated the results of our models against the procedures that had been in use in the company. It was concluded...

  16. Demand controllers with optimized programing; Controladores de demanda com programacao otimizada

    Energy Technology Data Exchange (ETDEWEB)

    Santos, A.H.M.; Haddad, J.; Almeida, A.T.L. [Escola Federal de Engenharia de Itajuba, MG (Brazil); Devienne, R.F. [Universidade de Taubate (UNITAU), SP (Brazil)

    1995-12-31

    This work presents a methodological proposal for load re-allocation strategy in opposition to the empiric methodology presently used by demand controllers. Through the utilization of dynamic programing techniques associated to fuzzy theory it is possible to modulate the electric power consumers load curve, incorporating different objectives resulting in the global energy consumption rationing 6 figs., 5 tabs., 8 refs.

  17. Burnout and engagement at work as a function of demands and control

    NARCIS (Netherlands)

    Demerouti, E.; Bakker, A.B.; Jonge, J. de; Janssen, P.P.M.; Schaufeli, W.B.

    2001-01-01

    Objectives The present study was designed to test the demand-control model using indicators of both health impairment and active learning or motivation. Methods A total of 381 insurance company employees participated in the study. Discriminant analysis was used to examine the relationship between

  18. Interactive Effects of Emotional Dissonance and Self-Control Demands on Burnout, Anxiety, and Absenteeism

    Science.gov (United States)

    Diestel, Stefan; Schmidt, Klaus-Helmut

    2010-01-01

    Two specific sources of stress at work have recently received increasing attention in organizational stress research: emotional dissonance (ED) and self-control demands (SCDs). Both theoretical arguments and experimental findings in basic research strongly suggest that ED and different SCDs draw on a common limited regulatory resource.…

  19. The Very Best of the Millennium: Longitudinal Research and the Demand-Control-(Support) Model

    NARCIS (Netherlands)

    Lange, A.H.de; Taris, T.W.; Kompier, M.A.J.; Houtman, I.L.D.; Bongers, P.M.

    2003-01-01

    This study addressed the methodological quality of longitudinal research examining R. Karasek and T. Theorell's (1990) demand-control-(support) model and reviewed the results of the best of this research. Five criteria for evaluating methodological quality were used: type of design, length of time

  20. "The very best of the Millennium": Longitudinal research and the Demand-Control-(Support) model

    NARCIS (Netherlands)

    de Lange, A.H.; Taris, T.W.; Kompier, M.A.J.; Houtman, I.L.D.; Bongers, P.M.

    2003-01-01

    This study addressed the methodological quality of longitudinal research examining R. Karasek and T. Theorell's (1990) demand-control-(support) model and reviewed the results of the best of this research. Five criteria for evaluating methodological quality were used: type of design, length of time

  1. The very best of the millennium: Longitudinal research and the demands-control (-support) model

    NARCIS (Netherlands)

    Lange, A.H. de; Taris, T.W.; Kompier, M.A.J.; Houtman, I.L.D.; Bongers, P.M.

    2003-01-01

    This study addressed the methodological quality of longitudinal research examining R. Karasek and T. Theorell’s (1990) demand-control-(support) model and reviewed the results of the best of this research. Five criteria for evaluating methodological quality were used: type of design, length of time

  2. The Demand-Control-Support model and intent to leave across six European Countries

    NARCIS (Netherlands)

    Widerszal-Bazyl, Maria; Radkiewicz, Piotr; Hasselhorn, Hans Martin; Conway, Paul Maurice; van der Heijden, Beatrice

    2008-01-01

    In this paper, the explanatory power of the Demand-Control-Support (DCS) model for intent to leave (ITL) a job was tested, with employment opportunities (EO) taken into consideration. It was hypothesized that, when employment opportunities are low, the explanatory power of the DCS model for ITL is

  3. Predicting and Explaining Students' Stress with the Demand-Control Model: Does Neuroticism Also Matter?

    Science.gov (United States)

    Schmidt, Laura I.; Sieverding, Monika; Scheiter, Fabian; Obergfell, Julia

    2015-01-01

    University students often report high stress levels, and studies even suggest a recent increase. However, there is a lack of theoretically based research on the structural conditions that influence students' perceived stress. The current study compared the effects of Karasek's demand-control dimensions with the influence of neuroticism to address…

  4. Exact Fill Rates for (R, s, S) Inventory Control With Gamma Distributed Demand

    NARCIS (Netherlands)

    Moors, J.J.A.; Strijbosch, L.W.G.

    2001-01-01

    For the familiar (R; s; S) inventory control system only approximate expressions exist for the fill rate, i.e. the fraction of demand that can be satisfied from stock.Best-known are the approximations derived from renewal theory by Tijms & Groenevelt (1984), holding under specific conditions; in

  5. An up-link power control for demand assignment International Business Satellite Communications Network

    Science.gov (United States)

    Nohara, Mitsuo; Takeuchi, Yoshio; Takahata, Fumio

    Up-link power control (UPC) is one of the essential technologies to provide efficient satellite communication systems operated at frequency bands above 10 GHz. A simple and cost-effective UPC scheme applicable to a demand assignment international business satellite communications system has been developed. This paper presents the UPC scheme, including the hardware implementation and its performance.

  6. Dynamic Behaviour of a Population of Controlled-by-price Demand Side Resources

    DEFF Research Database (Denmark)

    Sossan, Fabrizio; Han, Xue; Bindner, Henrik W.

    2014-01-01

    It is described that controlling or shedding by price the power consumption of a population of thermostatic loads introduces in the aggregate consumption dynamic effects th at cannot be disregarded if electrical flexible demand is meant to supply power system services. It is shown that inducing...

  7. Demand management through centralized control system using power line communication for existing buildings

    International Nuclear Information System (INIS)

    Al-Mulla, A.; ElSherbini, A.

    2014-01-01

    Highlights: • A pilot system was developed for demand management of equipment in buildings. • The networking was based on LonWorks platform and power line communication. • Demand strategies led to load reductions up to 74% and energy savings up to 25%. • The peak load reduction is expected to reach 3.44 GW by the year 2030. - Abstract: Managing peak demand efficiently is vital for maintaining uninterrupted supply of electrical power by utility providers. In this work, a pilot system was developed for managing and controlling the demand of major power consuming equipment in buildings from a central server, while relying mostly on existing infrastructure and maintaining consumer comfort. The system was successfully demonstrated on a selected group of buildings using the LonWorks networking platform. At the building level, the system utilized power line and twisted pair communication to control the thermostats of air-conditioning (A/C) units. The higher level communication was executed through extensible markup language (XML) and simple object access protocol (SOAP). The system provided control capabilities based on A/C unit priority, thermostat temperature, building type and geographic location. The development and execution of demand management strategies for selected buildings led to peak load reductions up to 74%, in addition to energy savings up to 25%. Implementing such a system at a national level in Kuwait is estimated to reduce peak demand by 3.44 GW, amounting to capital savings of $4.13 billion. The use of existing infrastructure reduced the cost and installation time of the system. Based on the successful testing of this pilot system, a larger-scale system is being developed

  8. Different Optimal Control Strategies for Exploitation of Demand Response in the Smart Grid

    DEFF Research Database (Denmark)

    Zong, Yi; Bindner, Henrik W.; Gehrke, Oliver

    2012-01-01

    To achieve a Danish energy supply based on 100% renewable energy from combinations of wind, biomass, wave and solar power in 2050 and to cover 50% of the Danish electricity consumption by wind power in 2025, it requires coordinated management of large numbers of distributed and demand response...... resources, intermittent renewable energy resources in the Smart Grid. This paper presents different optimal control (Genetic Algorithm-based and Model Predictive Control-based) algorithms that schedule controlled loads in the industrial and residential sectors, based on dynamic price and weather forecast......, considering users’ comfort settings to meet an optimization objective, such as maximum profit or minimum energy consumption. It is demonstrated in this work that the GA-based and MPC-based optimal control strategies are able to achieve load shifting for grid reliability and energy savings, including demand...

  9. Dimensional structure of the demand control support questionnaire: a Brazilian context.

    Science.gov (United States)

    Hökerberg, Yara Hahr Marques; Aguiar, Odaleia Barbosa; Reichenheim, Michael; Faerstein, Eduardo; Valente, Joaquim Gonçalves; Fonseca, Maria de Jesus; Passos, Sonia Regina Lambert

    2010-04-01

    According to Karasek, job strain results from an interaction between high demands and low decision latitude. To reassess the dimensional structure and evaluate the internal consistency of demand control support questionnaire (DCSQ), a shortened version of job content questionnaire that was not sufficiently evaluated in validation studies. The study investigated 825 workers who completed the DCSQ in Rio de Janeiro, Brazil; to 399 workers, the questionnaire was self-administered at a hospital (2004-2005), and 426 workers were interviewed at nine restaurants (2006-2007). Confirmatory factor analysis using structural equation models was used to test theoretical structure of dimensionality. Internal consistency was evaluated by composite reliability and convergent validity by average variance extracted. Confirmatory factor analysis supported the instrument in three dimensions: demands, skill discretion and decision authority. The best fit model was achieved by removing social support at work and the item repetitive work (skill discretion). A cross-loading from learning new things on demands and an error measurement correlation between work fast and work intense were confirmed. Composite reliability was acceptable for all dimensions, except for demands (0.58), which also showed inadequate average variance extracted (0.32). This final model was confirmed in separate analyses according to work setting, but the loadings of demands were lower for restaurant workers. Our results indicated that skill discretion and decision authority formed two distinct dimensions. Additionally, the item repetitive work should be removed, as well as one of the items work fast or work intense (demands). Future research is still required to confirm these findings.

  10. Job stress, fatigue, and job dissatisfaction in Dutch lorry drivers: towards an occupation specific model of job demands and control.

    Science.gov (United States)

    de Croon, E M; Blonk, R W B; de Zwart, B C H; Frings-Dresen, M H W; Broersen, J P J

    2002-06-01

    Building on Karasek's model of job demands and control (JD-C model), this study examined the effects of job control, quantitative workload, and two occupation specific job demands (physical demands and supervisor demands) on fatigue and job dissatisfaction in Dutch lorry drivers. From 1181 lorry drivers (adjusted response 63%) self reported information was gathered by questionnaire on the independent variables (job control, quantitative workload, physical demands, and supervisor demands) and the dependent variables (fatigue and job dissatisfaction). Stepwise multiple regression analyses were performed to examine the main effects of job demands and job control and the interaction effect between job control and job demands on fatigue and job dissatisfaction. The inclusion of physical and supervisor demands in the JD-C model explained a significant amount of variance in fatigue (3%) and job dissatisfaction (7%) over and above job control and quantitative workload. Moreover, in accordance with Karasek's interaction hypothesis, job control buffered the positive relation between quantitative workload and job dissatisfaction. Despite methodological limitations, the results suggest that the inclusion of (occupation) specific job control and job demand measures is a fruitful elaboration of the JD-C model. The occupation specific JD-C model gives occupational stress researchers better insight into the relation between the psychosocial work environment and wellbeing. Moreover, the occupation specific JD-C model may give practitioners more concrete and useful information about risk factors in the psychosocial work environment. Therefore, this model may provide points of departure for effective stress reducing interventions at work.

  11. Learning and strain among newcomers: a three-wave study on the effects of job demands and job control.

    Science.gov (United States)

    Taris, Toon W; Feij, Jan A

    2004-11-01

    The present 3-wave longitudinal study was an examination of job-related learning and strain as a function of job demand and job control. The participants were 311 newcomers to their jobs. On the basis of R. A. Karasek and T. Theorell's (1990) demand-control model, the authors predicted that high demand and high job control would lead to high levels of learning; low demand and low job control should lead to low levels of learning; high demand and low job control should lead to high levels of strain; and low demand and high job control should lead to low levels of strain. The relation between strain and learning was also examined. The authors tested the hypotheses using ANCOVA and structural equation modeling. The results revealed that high levels of strain have an adverse effect on learning; the reverse effect was not confirmed. It appears that Karasek and Theorell's model is very relevant when examining work socialization processes.

  12. An Analysis of Decentralized Demand Response as Frequency Control Support under CriticalWind Power Oscillations

    Directory of Open Access Journals (Sweden)

    Jorge Villena

    2015-11-01

    Full Text Available In power systems with high wind energy penetration, the conjunction of wind power fluctuations and power system inertia reduction can lead to large frequency excursions, where the operating reserves of conventional power generation may be insufficient to restore the power balance. With the aim of evaluating the demand-side contribution to frequency control, a complete process to determine critical wind oscillations in power systems with high wind penetration is discussed and described in this paper. This process implies thousands of wind power series simulations, which have been carried out through a validated offshore wind farm model. A large number of different conditions have been taken into account, such as frequency dead bands, the percentages of controllable demand and seasonal factor influence on controllable loads. Relevant results and statistics are also included in the paper.

  13. Selective verbal recognition memory impairments are associated with atrophy of the language network in non-semantic variants of primary progressive aphasia.

    Science.gov (United States)

    Nilakantan, Aneesha S; Voss, Joel L; Weintraub, Sandra; Mesulam, M-Marsel; Rogalski, Emily J

    2017-06-01

    Primary progressive aphasia (PPA) is clinically defined by an initial loss of language function and preservation of other cognitive abilities, including episodic memory. While PPA primarily affects the left-lateralized perisylvian language network, some clinical neuropsychological tests suggest concurrent initial memory loss. The goal of this study was to test recognition memory of objects and words in the visual and auditory modality to separate language-processing impairments from retentive memory in PPA. Individuals with non-semantic PPA had longer reaction times and higher false alarms for auditory word stimuli compared to visual object stimuli. Moreover, false alarms for auditory word recognition memory were related to cortical thickness within the left inferior frontal gyrus and left temporal pole, while false alarms for visual object recognition memory was related to cortical thickness within the right-temporal pole. This pattern of results suggests that specific vulnerability in processing verbal stimuli can hinder episodic memory in PPA, and provides evidence for differential contributions of the left and right temporal poles in word and object recognition memory. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. A Daily Diary Study of Coping in the Context of the Job Demands-Control-Support Model

    Science.gov (United States)

    Daniels, Kevin; Harris, Claire

    2005-01-01

    We examined one of the processes thought to underpin Karasek and Theorell's job demands-control-support model (1990). This is that control and support accentuate better well-being by fostering problem-focused coping with work demands. We also examined whether other forms of coping implemented through control and support are related to indicators…

  15. Control Scheme Formulation for the Production of Hydrogen on Demand to Feed an Internal Combustion Engine

    Directory of Open Access Journals (Sweden)

    Jarniel García Morales

    2016-12-01

    Full Text Available In this work, a control strategy is presented to produce hydrogen on demand to feed an internal combustion (IC engine. For this purpose, the modeling of the IC engine fueled by gasoline blended with 10 % v/v of anhydrous ethanol (E10 and hydrogen as an additive is developed. It is considered that the hydrogen gas is produced according to the IC engine demand, and that the hydrogen gas is obtained by an alkaline electrolyzer. The gasoline–ethanol blend added into the combustion chamber is determined according to the stoichiometric ratio and the production of hydrogen gas is regulated by a proportional and integral controller (P.I.. The controller reference is varying according to the mass flow air induced into the cylinder, in order to ensure an adequate production of hydrogen gas for any operating condition of the IC engine. The main contribution of this work is the control scheme developed, through simulation, in order to produce hydrogen on demand for any operating point of an internal combustion engine fueled by an E10 blend. The simulation results showed that the use of hydrogen gas as an additive in an E10 blend decreases the E10 fuel consumption 23 % on average, and the thermal efficiency is increased approximately 2.13 % , without brake power loss in the IC engine.

  16. The supply and demand for pollution control: Evidence from wastewater treatment

    Science.gov (United States)

    McConnell, V.D.; Schwarz, G.E.

    1992-01-01

    This paper analyzes the determination of pollution control from wastewater treatment plants as an economic decision facing local or regional regulators. Pollution control is measured by plant design effluent concentration levels and is fully endogenous in a supply- and-demand model of treatment choice. On the supply side, plant costs are a function of the design treatment level of the plant, and on the demand side, treatment level is a function of both the costs of control and the regional or regulatory preferences for control. We find evidence that the economic model of effluent choice by local regulators has a good deal of explanatory power. We find evidence that wastewater treatment plant removal of biological oxygen demand (BOD) is sensitive to many local factors including the size of the treatment plant, the flow rate of the receiving water, the population density of the surrounding area, regional growth, state sensitivity to environmental issues, state income, and the extent to which the damages from pollution fall on other states. We find strong evidence that regulators are sensitive to capital costs in determining the design level of BOD effluent reduction at a plant. Thus, proposed reductions in federal subsidies for wastewater treatment plant construction are likely to have significant adverse effects on water quality. ?? 1992.

  17. Energy efficient ventilation based on demand humidity control. Demonstration project with 49 apartments in Soenderborg

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    The aim of the project is to demonstrate how the overall energy consumption in apartment buildings can be reduced through a combination of: 1) Energy efficient ventilation based on demand humidity control; 2) Energy efficient design of the building shell including passive solar and seasonally flexible sunspaces; 3) Use of low temperature heating system. The 3 blocks in the project, each with 16 apartments, are furnished with 3 different ventilation systems: 1) Standard exhaust system according to building codes; 2) Ventilation system with humidity control. Each room is furnished with an air inlet valve controlled by a processor, which monitors the humidity; 3) Standard ventilation system with heat recovery. (au)

  18. Hardware-in-the-loop (HIL) Test of Demand as Frequency Controlled Reserve (DFR)

    DEFF Research Database (Denmark)

    Wu, Qiuwei; Zimmermann, K.; Østergaard, Jacob

    2016-01-01

    This paper presents the hardware-in-the-loop (HIL) test of the demand as frequency controlled reserve (DFR). The HIL test refers to a test in which parts of a pure simulation have been replaced by actual physical components. It is used to understand the behavior of a new device or controller....... The DFR has been tested by offline simulations to illustrate the efficacy of this technology. The DFR control logics have been implemented in the SmartBox. The HIL was conducted by having the SmartBox connected to the real time simulations and the performance of the SmartBox was tested with difference...

  19. On Inventory Control For Perishable Inventory Systems Subject To Uncertainties On Customer Demands

    OpenAIRE

    Abbou , Rosa; Loiseau , Jean-Jacques; Khaldi , Hajer; Farraa , Berna ,

    2017-01-01

    International audience; This paper deals with the inventory controller design for constrained production systems subject to uncertainties on the customer demands. The case study focuses on the inventory regulation problem in production systems where contain perishable finite products. Such systems are characterized by the presence of delays due to production processes, and constraints from the instantaneous inventory level, production level and the finite capacities of stocks. To do that, we ...

  20. An Overview of Demand Side Management Control Schemes for Buildings in Smart Grids

    DEFF Research Database (Denmark)

    Kosek, Anna Magdalena; Costanzo, Giuseppe Tommaso; Bindner, Henrik W.

    2013-01-01

    The increasing share of distributed energy resources and renewable energy in power systems results in a highly variable and less controllable energy production. Therefore, in order to ensure stability and to reduce the infrastructure and operation cost of the power grid, flexible and controllable...... of the power sector in mind and thus can differ significantly in their architecture, their integration into the various markets, their integration into distribution network operation and several other aspects. This paper proposes a classification of load control policies for demand side management in smart...... buildings, based on external behavior: direct, indirect, transactional and autonomous control; internal operation: decision support system scope, control strategy, failure handling and architecture. This classification assists in providing an overview of the control schemes as well as different ways...

  1. Interaction between demand-control and social support in the occurrence of common mental disorders

    Directory of Open Access Journals (Sweden)

    Amália Ivine Santana Mattos

    Full Text Available ABSTRACT OBJECTIVE To analyze the interaction between the psychosocial aspects of work and the occurrence of common mental disorders among health workers. METHODS This is a cross-sectional study conducted with a representative sample of workers of the primary health care of five municipalities of the State of Bahia, Brazil, in 2012. The variable of outcome were the common mental disorders evaluated by the SRQ-20, and the variables of exposure were high demand (high psychological demand and low control over the work and low social support in the workplace. Interaction was checked by the deviation of the additivity of the effects for the factors studied from the calculation of excess risk from interaction, proportion of cases attributed to interaction, and the synergy index. RESULTS The global prevalence of common mental disorders was 21%. The group of combined exposure has shown higher magnitude (high demand and low social support, reaching 28% when compared to the 17% in the situation of no exposure (low demand and high social support. CONCLUSIONS The results strengthen the hypothesis of interaction between the factors investigated, directing to the synergy of the effects.

  2. Cross-lagged relationships between workplace demands, control, support, and sleep problems.

    Science.gov (United States)

    Hanson, Linda L Magnusson; Åkerstedt, Torbjörn; Näswall, Katharina; Leineweber, Constanze; Theorell, Töres; Westerlund, Hugo

    2011-10-01

    Sleep problems are experienced by a large part of the population. Work characteristics are potential determinants, but limited longitudinal evidence is available to date, and reverse causation is a plausible alternative. This study examines longitudinal, bidirectional relationships between work characteristics and sleep problems. Prospective cohort/two-wave panel. Sweden. 3065 working men and women approximately representative of the Swedish workforce who responded to the 2006 and 2008 waves of the Swedish Longitudinal Occupational Survey of Health (SLOSH). N/A. Bidirectional relationships between, on the one hand, workplace demands, decision authority, and support, and, on the other hand, sleep disturbances (reflecting lack of sleep continuity) and awakening problems (reflecting feelings of being insufficiently restored), were investigated by structural equation modeling. All factors were modeled as latent variables and adjusted for gender, age, marital status, education, alcohol consumption, and job change. Concerning sleep disturbances, the best fitting models were the "forward" causal model for demands and the "reverse" causal model for support. Regarding awakening problems, reciprocal models fitted the data best. Cross-lagged analyses indicates a weak relationship between demands at Time 1 and sleep disturbances at Time 2, a "reverse" relationship from support T1 to sleep disturbances T2, and bidirectional associations between work characteristics and awakening problems. In contrast to an earlier study on demands, control, sleep quality, and fatigue, this study suggests reverse and reciprocal in addition to the commonly hypothesized causal relationships between work characteristics and sleep problems based on a 2-year time lag.

  3. Controlling market power and price spikes in electricity networks: Demand-side bidding.

    Science.gov (United States)

    Rassenti, Stephen J; Smith, Vernon L; Wilson, Bart J

    2003-03-04

    In this article we report an experiment that examines how demand-side bidding can discipline generators in a market for electric power. First we develop a treatment without demand-side bidding; two large firms are allocated baseload and intermediate cost generators such that either firm might unilaterally withhold the capacity of its intermediate cost generators from the market to benefit from the supracompetitive prices that would result from only selling its baseload units. In a converse treatment, ownership of some of the intermediate cost generators is transferred from each of these firms to two other firms such that no one firm could unilaterally restrict output to spawn supracompetitive prices. Having established a well controlled data set with price spikes paralleling those observed in the naturally occurring economy, we also extend the design to include demand-side bidding. We find that demand-side bidding completely neutralizes the exercise of market power and eliminates price spikes even in the presence of structural market power.

  4. Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices

    Science.gov (United States)

    Chassin, David P [Pasco, WA; Donnelly, Matthew K [Kennewick, WA; Dagle, Jeffery E [Richland, WA

    2011-12-06

    Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices are described. In one aspect, an electrical power distribution control method includes providing electrical energy from an electrical power distribution system, applying the electrical energy to a load, providing a plurality of different values for a threshold at a plurality of moments in time and corresponding to an electrical characteristic of the electrical energy, and adjusting an amount of the electrical energy applied to the load responsive to an electrical characteristic of the electrical energy triggering one of the values of the threshold at the respective moment in time.

  5. A hard day's night : a longitudinal study on the relationships among job demands and job control, sleep quality and fatigue

    NARCIS (Netherlands)

    De Lange, Annet H.; Kompier, Michiel A. J.; Taris, Toon W.; Geurts, Sabine A. E.; Beckers, Debby G. J.; Houtman, Irene L. D.; Bongers, Paulien M.

    This prospective four-wave study examined (i) the causal direction of the longitudinal relations among job demands, job control, sleep quality and fatigue; and (ii) the effects of stability and change in demand-control history on the development of sleep quality and fatigue. Based on results of a

  6. A hard day's night: a longitudinal study on the relationships among job demands and job control, sleep quality and fatigue

    NARCIS (Netherlands)

    Lange, A.H. de; Kompier, M.A.J.; Taris, T.W.; Geurts, S.A.E.; Beckers, D.G.J.; Houtman, I.L.D.; Bongers, P.M.

    2009-01-01

    This prospective four-wave study examined (i) the causal direction of the longitudinal relations among job demands, job control, sleep quality and fatigue; and (ii) the effects of stability and change in demand-control history on the development of sleep quality and fatigue. Based on results of a

  7. A hard day's night: a longitudinal study on the relationships among job demands and job control, sleep quality and fatigue

    NARCIS (Netherlands)

    de Lange, A.H.; Kompier, M.A.J.; Taris, T.W.; Geurts, S.A.E.; Beckers, D.G.J.; Houtman, I.L.H.; Bongers, P.M.

    2009-01-01

    Summary This prospective four-wave study examined (i) the causal direction of the longitudinal relations among job demands, job control, sleep quality and fatigue; and (ii) the effects of stability and change in demand-control history on the development of sleep quality and fatigue. Based on results

  8. A hard day's night: A longitudinal study on the relationships among job demands and job control, sleep quality and fatigue

    NARCIS (Netherlands)

    Lange, A.H.de; Kompier, M.A.J.; Taris, T.W.; Geurts, S.A.E.; Beckers, D.G.J.; Houtman, I.L.D.; Bongers, P.M.

    2009-01-01

    This prospective four-wave study examined (i) the causal direction of the longitudinal relations among job demands, job control, sleep quality and fatigue; and (ii) the effects of stability and change in demand-control history on the development of sleep quality and fatigue. Based on results of a

  9. Learning and strain among newcomers: a three-wave study on the effects of Job Demands and Job Control

    NARCIS (Netherlands)

    Taris, T.W.; Feij, J.A.

    2004-01-01

    The present 3-wave longitudinal study was an examination of job-related learning and strain as a function of job demand and job control. The participants were 311 newcomers to their jobs. On the basis of R. A. Karasek and T. Theorell's (1990) demand-control model, the authors predicted that high

  10. Job stress, fatigue, and job dissatisfaction in Dutch lorry drivers: towards an occupation specific model of job demands and control

    NARCIS (Netherlands)

    Croon, E.M. de; Blonk, R.W.B.; Zwart, B.C.H. de; Frings-Dresen, M.H.W.; Broersen, J.P.J.

    2002-01-01

    Building on Karasek's model of job demands and control (JD-C model), this study examined the effects of job control, quantitative workload, and two occupation specific job demands on fatigue and job dissatisfaction in Dutch lorry drivers. From 1181 lorry drivers self reported information was

  11. Controllable deterioration rate for time-dependent demand and time-varying holding cost

    Directory of Open Access Journals (Sweden)

    Mishra Vinod Kumar

    2014-01-01

    Full Text Available In this paper, we develop an inventory model for non-instantaneous deteriorating items under the consideration of the facts: deterioration rate can be controlled by using the preservation technology (PT during deteriorating period, and holding cost and demand rate both are linear function of time, which was treated as constant in most of the deteriorating inventory models. So in this paper, we developed a deterministic inventory model for non-instantaneous deteriorating items in which both demand rate and holding cost are a linear function of time, deterioration rate is constant, backlogging rate is variable and depend on the length of the next replenishment, shortages are allowed and partially backlogged. The model is solved analytically by minimizing the total cost of the inventory system. The model can be applied to optimizing the total inventory cost of non-instantaneous deteriorating items inventory for the business enterprises, where the preservation technology is used to control the deterioration rate, and demand & holding cost both are a linear function of time.

  12. Relative effects of demand and control on task-related cardiovascular reactivity, task perceptions, performance accuracy, and mood.

    Science.gov (United States)

    Flynn, Niamh; James, Jack E

    2009-05-01

    The hypothesis that work control has beneficial effects on well-being is the basis of the widely applied, yet inconsistently supported, Job Demand Control (JDC) Model [Karasek, R.A., 1979. Job demands, job decision latitude and mental strain: Implications for job redesign. Adm. Sci. Q. 24, 285-308.; Karasek, R., Theorell, T., 1990. Healthy Work: Stress, Productivity, and the Reconstruction of Working Life. Basic Books, Oxford]. The model was tested in an experiment (N=60) using a cognitive stressor paradigm that sought to prevent confounding between demand and control. High-demand was found to be associated with deleterious effects on physiological, subjective, and performance outcomes. In contrast, few main effects were found for control. Evidence for the buffer interpretation of the JDC Model was limited to a significant demand-control interaction for performance accuracy, whereas substantial support was found for the strain interpretation of the model [van der Doef, M., Maes, S., 1998. The job demand-control(-support) model and physical health outcomes: A review of the strain and buffer hypotheses. Psychol. Health 13, 909-936., van der Doef, M., Maes, S., 1999. The Job Demand-Control(-Support) model and psychological well-being: A review of 20 years of empirical research. Work Stress 13, 87-114]. Manipulation checks revealed that objective control altered perceptions of control but not perceptions of demand. It is suggested that beneficial effects of work-related control are unlikely to occur in the absence of reductions in perceived demand. Thus, contrary to the propositions of Karasek and colleagues, demand and control do not appear to be independent factors.

  13. Multi-Time Scale Control of Demand Flexibility in Smart Distribution Networks

    Directory of Open Access Journals (Sweden)

    Bishnu P. Bhattarai

    2017-01-01

    Full Text Available This paper presents a multi-timescale control strategy to deploy electric vehicle (EV demand flexibility for simultaneously providing power balancing, grid congestion management, and economic benefits to participating actors. First, an EV charging problem is investigated from consumer, aggregator, and distribution system operator’s perspectives. A hierarchical control architecture (HCA comprising scheduling, coordinative, and adaptive layers is then designed to realize their coordinative goal. This is realized by integrating multi-time scale controls that work from a day-ahead scheduling up to real-time adaptive control. The performance of the developed method is investigated with high EV penetration in a typical residential distribution grid. The simulation results demonstrate that HCA efficiently utilizes demand flexibility stemming from EVs to solve grid unbalancing and congestions with simultaneous maximization of economic benefits to the participating actors. This is ensured by enabling EV participation in day-ahead, balancing, and regulation markets. For the given network configuration and pricing structure, HCA ensures the EV owners to get paid up to five times the cost they were paying without control.

  14. Flexible Demand Control to Enhance the Dynamic Operation of Low Voltage Networks

    DEFF Research Database (Denmark)

    Diaz de Cerio Mendaza, Iker; Szczesny, Ireneusz Grzegorz; Pillai, Jayakrishnan Radhakrishna

    2015-01-01

    Moving towards a carbon free energy system has become an objective for many countries nowadays. Among other changes, the electrification of strategic sectors such as heating and transportation is inevitable. As a consequence, the current power system load will substantially increase...... for controlling the demand response of a low voltage grid. This is designed to; i) maximize the grid utilization, thereby reducing the need for reinforcement, ii) accommodate the maximum number of flexible loads and iii) satisfy the power and comfort requirements from each of the consumers in the network....... In this context, the nature of the expected loads (heat pumps, plug-in electric vehicles, etc.) makes the low voltage networks specially targeted. A promising solution to overcome the challenges resulting from their grid integration, is demand response. This paper introduces a hierarchical structure...

  15. Optimal strategy analysis based on robust predictive control for inventory system with random demand

    Science.gov (United States)

    Saputra, Aditya; Widowati, Sutrisno

    2017-12-01

    In this paper, the optimal strategy for a single product single supplier inventory system with random demand is analyzed by using robust predictive control with additive random parameter. We formulate the dynamical system of this system as a linear state space with additive random parameter. To determine and analyze the optimal strategy for the given inventory system, we use robust predictive control approach which gives the optimal strategy i.e. the optimal product volume that should be purchased from the supplier for each time period so that the expected cost is minimal. A numerical simulation is performed with some generated random inventory data. We simulate in MATLAB software where the inventory level must be controlled as close as possible to a set point decided by us. From the results, robust predictive control model provides the optimal strategy i.e. the optimal product volume that should be purchased and the inventory level was followed the given set point.

  16. Day-Ahead Scheduling Considering Demand Response as a Frequency Control Resource

    Directory of Open Access Journals (Sweden)

    Yu-Qing Bao

    2017-01-01

    Full Text Available The development of advanced metering technologies makes demand response (DR able to provide fast response services, e.g., primary frequency control. It is recognized that DR can contribute to the primary frequency control like thermal generators. This paper proposes a day-ahead scheduling method that considers DR as a frequency control resource, so that the DR resources can be dispatched properly with other resources. In the proposed method, the objective of frequency control is realized by defining a frequency limit equation under a supposed contingency. The frequency response model is used to model the dynamics of system frequency. The nonlinear frequency limit equation is transformed to a linear arithmetic equation by piecewise linearization, so that the problem can be solved by mixed integer linear programming (MILP. Finally, the proposed method is verified on numerical examples.

  17. Effects of Granular Control on Customers’ Perspective and Behavior with Automated Demand Response Systems

    Energy Technology Data Exchange (ETDEWEB)

    Schetrit, Oren; Kim, Joyce; Yin, Rongxin; Kiliccote, Sila

    2014-08-01

    Automated demand response (Auto-DR) is expected to close the loop between buildings and the grid by providing machine-to-machine communications to curtail loads without the need for human intervention. Hence, it can offer more reliable and repeatable demand response results to the grid than the manual approach and make demand response participation a hassle-free experience for customers. However, many building operators misunderstand Auto-DR and are afraid of losing control over their building operation. To ease the transition from manual to Auto-DR, we designed and implemented granular control of Auto-DR systems so that building operators could modify or opt out of individual load-shed strategies whenever they wanted. This paper reports the research findings from this effort demonstrated through a field study in large commercial buildings located in New York City. We focused on (1) understanding how providing granular control affects building operators’ perspective on Auto-DR, and (2) evaluating the usefulness of granular control by examining their interaction with the Auto-DR user interface during test events. Through trend log analysis, interviews, and surveys, we found that: (1) the opt-out capability during Auto-DR events can remove the feeling of being forced into load curtailments and increase their willingness to adopt Auto-DR; (2) being able to modify individual load-shed strategies allows flexible Auto-DR participation that meets the building’s changing operational requirements; (3) a clear display of automation strategies helps building operators easily identify how Auto-DR is functioning and can build trust in Auto-DR systems.

  18. The moderating effect of control over work scheduling and overtime on the relationship between workload demands and perceived job risk.

    Science.gov (United States)

    Näswall, Katharina; Burt, Christopher D B; Pearce, Megan

    2015-01-01

    This study investigated the impact of workload demands on perceived job risk using the Job Demand-Control model as a research framework. The primary objective was to test the hypothesis that employee control over work scheduling and overtime would moderate the relationship between workload demands and perceived job risk. Ninety-six participants working in a variety of industries completed measures of workload demands, and of control over work scheduling and overtime, and a measure of perceived job risk. Workload demands predicted higher perceptions of job risk. However, the results also suggest that control over overtime moderated this relationship, where those with the combination of high workload demands and low control over overtime reported higher levels of perceived risk. The results indicate that the JDC model is applicable to safety research. The results suggest that employee control over workload demands is an important variable to consider in terms of managing workplace safety. The present study also points to important areas for future research to explore in order to further understand the connection between demands and safety.

  19. Experimental analysis of fuzzy controlled energy efficient demand controlled ventilation economizer cycle variable air volume air conditioning system

    Directory of Open Access Journals (Sweden)

    Rajagopalan Parameshwaran

    2008-01-01

    Full Text Available In the quest for energy conservative building design, there is now a great opportunity for a flexible and sophisticated air conditioning system capable of addressing better thermal comfort, indoor air quality, and energy efficiency, that are strongly desired. The variable refrigerant volume air conditioning system provides considerable energy savings, cost effectiveness and reduced space requirements. Applications of intelligent control like fuzzy logic controller, especially adapted to variable air volume air conditioning systems, have drawn more interest in recent years than classical control systems. An experimental analysis was performed to investigate the inherent operational characteristics of the combined variable refrigerant volume and variable air volume air conditioning systems under fixed ventilation, demand controlled ventilation, and combined demand controlled ventilation and economizer cycle techniques for two seasonal conditions. The test results of the variable refrigerant volume and variable air volume air conditioning system for each techniques are presented. The test results infer that the system controlled by fuzzy logic methodology and operated under the CO2 based mechanical ventilation scheme, effectively yields 37% and 56% per day of average energy-saving in summer and winter conditions, respectively. Based on the experimental results, the fuzzy based combined system can be considered to be an alternative energy efficient air conditioning scheme, having significant energy-saving potential compared to the conventional constant air volume air conditioning system.

  20. Effective production control in an automotive industry: MRP vs. demand-driven MRP

    Science.gov (United States)

    Shofa, Mohamad Jihan; Widyarto, Wahyu Oktri

    2017-06-01

    Material Requirements Planning (MRP) has deficiencies when dealing with current business environments, marked by a more complex network, a huge variety of products with longer lead time, and uncertain demands. This drives Demand-Driven MRP (DDMRP) approach to deal with those challenges. DDMRP is designed to connect the availability of materials and supplies directly from the actual condition using bills of materials (BOMs). Nevertheless, only few studies have scientifically proved the performance of DDMRP over MRP for controlling production and inventory control. Therefore, this research fills this gap by evaluating and comparing the performance of DDMRP and MRP in terms of level of effective inventory in the system. The evaluation was conducted through a simulation using data from an automotive company in Indonesia. The input parameters of scenarios were given for running the simulation. Based on the simulation, for the observed critical parts, DDMRP gave better results than MRP in terms of lead time and inventory level. DDMRP compressed the lead time part from 52 to 3 days (94% reduced) and, overall, the inventory level was in an effective condition. This suggests that DDMRP is more effective for controlling the production-inventory than MRP.

  1. Multi-Time Scale Control of Demand Flexibility in Smart Distribution Networks

    DEFF Research Database (Denmark)

    Bhattarai, Bishnu P.; Myers, Kurt S.; Bak-Jensen, Birgitte

    2017-01-01

    , and distribution system operator’s perspectives. A hierarchical control architecture (HCA) comprising scheduling, coordinative, and adaptive layers is then designed to realize their coordinative goal. This is realized by integrating multi-time scale controls that work from a day-ahead scheduling up to real-time...... adaptive control. The performance of the developed method is investigated with high EV penetration in a typical residential distribution grid. The simulation results demonstrate that HCA efficiently utilizes demand flexibility stemming from EVs to solve grid unbalancing and congestions with simultaneous...... maximization of economic benefits to the participating actors. This is ensured by enabling EV participation in day-ahead, balancing, and regulation markets. For the given network configuration and pricing structure, HCA ensures the EV owners to get paid up to five times the cost they were paying without...

  2. An inventory control project in a major Danish company using compound renewal demand models

    DEFF Research Database (Denmark)

    Larsen, Christian; Seiding, Claus Hoe; Teller, Christian

    operation is highly automated. However, the procedures for estimating demands and the policies for the inventory control system that were in use at the beginning of the project did not fully match the sophisticated technological standard of the physical system. During the initial phase of the project...... We describe the development of a framework to compute the optimal inventory policy for a large spare-parts' distribution centre operation in the RA division of the Danfoss Group in Denmark. The RA division distributes spare parts worldwide for cooling and A/C systems. The warehouse logistics...

  3. The effects of moderate fatigue on dynamic balance control and attentional demands

    Directory of Open Access Journals (Sweden)

    Teasdale Normand

    2006-09-01

    Full Text Available Abstract Background During daily activities, the active control of balance often is a task per se (for example, when standing in a moving bus. Other constraints like fatigue can add to the complexity of this balance task. In the present experiment, we examined how moderate fatigue induced by fast walking on a treadmill challenged dynamic balance control. We also examined if the attentional demands for performing the balance task varied with fatigue. Methods Subjects (n = 10 performed simultaneously a dynamic balance control task and a probe reaction time task (RT (serving as an indicator of attentional demands before and after three periods of moderate fatigue (fast walking on a treadmill. For the balance control task, the real-time displacement of the centre of pressure (CP was provided on a monitor placed in front of the subject, at eye level. Subjects were asked to keep their CP within a target (moving box moving upward and downward on the monitor. The tracking performance was measured (time spent outside the moving box and the CP behavior analyzed (mean CP speed and mean frequency of the CP velocity. Results Moderate fatigue led to an immediate decrement of the performance on the balance control task; increase of the percentage of time spent outside the box and increase of the mean CP speed. Across the three fatigue periods, subjects improved their tracking performance and reduced their mean CP speed. This was achieved by increasing their frequency of actions; mean frequency of the CP velocity were higher for the fatigue periods than for the no fatigue periods. Fatigue also induced an increase in the attentional demands suggesting that more cognitive resources had to be allocated to the balance task with than without fatigue. Conclusion Fatigue induced by fast walking had an initial negative impact on the control of balance. Nonetheless, subjects were able to compensate the effect of the moderate fatigue by increasing the frequency of

  4. Opportunities for Automated Demand Response in Wastewater Treatment Facilities in California - Southeast Water Pollution Control Plant Case Study

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Daniel [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Goli, Sasank [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Faulkner, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); McKane, Aimee [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-12-20

    This report details a study into the demand response potential of a large wastewater treatment facility in San Francisco. Previous research had identified wastewater treatment facilities as good candidates for demand response and automated demand response, and this study was conducted to investigate facility attributes that are conducive to demand response or which hinder its implementation. One years' worth of operational data were collected from the facility's control system, submetered process equipment, utility electricity demand records, and governmental weather stations. These data were analyzed to determine factors which affected facility power demand and demand response capabilities The average baseline demand at the Southeast facility was approximately 4 MW. During the rainy season (October-March) the facility treated 40% more wastewater than the dry season, but demand only increased by 4%. Submetering of the facility's lift pumps and centrifuges predicted load shifts capabilities of 154 kW and 86 kW, respectively, with large lift pump shifts in the rainy season. Analysis of demand data during maintenance events confirmed the magnitude of these possible load shifts, and indicated other areas of the facility with demand response potential. Load sheds were seen to be possible by shutting down a portion of the facility's aeration trains (average shed of 132 kW). Load shifts were seen to be possible by shifting operation of centrifuges, the gravity belt thickener, lift pumps, and external pump stations These load shifts were made possible by the storage capabilities of the facility and of the city's sewer system. Large load reductions (an average of 2,065 kW) were seen from operating the cogeneration unit, but normal practice is continuous operation, precluding its use for demand response. The study also identified potential demand response opportunities that warrant further study: modulating variable-demand aeration loads, shifting

  5. Stress and counterproductive work behavior: multiple relationships between demands, control, and soldier indiscipline over time.

    Science.gov (United States)

    Tucker, Jennifer S; Sinclair, Robert R; Mohr, Cynthia D; Thomas, Jeffrey L; Salvi, Angela D; Adler, Amy B

    2009-07-01

    Cognitive Resource Theory (CRT) suggests that under high levels of stress, employees are more prone to committing indiscipline. As few studies have examined this relationship over time, the authors conducted a six-wave longitudinal study examining the relationship of soldiers' indiscipline with work demands and control. The study included archival data collected quarterly over 2 years from 1,701 soldiers representing 10 units in garrison (Germany and Italy), in training rotations (Grafenwoehr, Germany), and on peacekeeping deployments (Kosovo, Kuwait). No main effects were found for work overload, and the findings for the moderating effects of control were contradictory. Within each time point, as work overload increased, soldiers who felt less control committed more indiscipline, supporting CRT. Over time, however, as work overload increased, soldiers who perceived less control 6 months earlier committed less indiscipline. Additionally, the authors found reverse causal effects for control such that prior perceptions of a lack of control were associated with indiscipline and prior incidents of indiscipline with less control. (c) 2009 APA, all rights reserved.

  6. How do Air Traffic Controllers Use Automation and Tools Differently During High Demand Situations?

    Science.gov (United States)

    Kraut, Joshua M.; Mercer, Joey; Morey, Susan; Homola, Jeffrey; Gomez, Ashley; Prevot, Thomas

    2013-01-01

    In a human-in-the-loop simulation, two air traffic controllers managed identical airspace while burdened with higher than average workload, and while using advanced tools and automation designed to assist with scheduling aircraft on multiple arrival flows to a single meter fix. This paper compares the strategies employed by each controller, and investigates how the controllers' strategies change while managing their airspace under more normal workload conditions and a higher workload condition. Each controller engaged in different methods of maneuvering aircraft to arrive on schedule, and adapted their strategies to cope with the increased workload in different ways. Based on the conclusions three suggestions are made: that quickly providing air traffic controllers with recommendations and information to assist with maneuvering and scheduling aircraft when burdened with increased workload will improve the air traffic controller's effectiveness, that the tools should adapt to the strategy currently employed by a controller, and that training should emphasize which traffic management strategies are most effective given specific airspace demands.

  7. Work ability in nursing: relationship with psychological demands and control over the work.

    Science.gov (United States)

    Prochnow, Andrea; Magnago, Tânia Solange Bosi de Souza; Urbanetto, Janete de Souza; Beck, Carmem Lúcia Colomé; Lima, Suzinara Beatriz Soares de; Greco, Patrícia Bitencourt Toscani

    2013-01-01

    to evaluate the association between psychological demands, control over the work and the reduction of work ability of nursing professionals. this cross-sectional study involved 498 nursing professionals of a university hospital in the State of Rio Grande do Sul, Brazil. Data collection was carried out in 2009 using the Brazilian versions of the Work Ability Index and Job Stress Scale, with logistic regression models used for the data analysis. the prevalence of 43.3% for reduced work ability and 29.7% for high-strain in the job (high psychological demand and low control) were observed. The chances for professionals presenting reduced work ability under high-strain were higher and significant when compared to those classified as being under low-strain, even after adjusting for potential confounders, except for age and gender. a high prevalence of reduced work ability was observed. This evidence indicates the need for investigation and detailed analysis of the psychosocial aspects of the professionals with regard to the health/disease process of nursing professionals.

  8. Demand Response Advanced Controls Framework and Assessment of Enabling Technology Costs

    Energy Technology Data Exchange (ETDEWEB)

    Potter, Jennifer; Cappers, Peter

    2017-08-28

    The Demand Response Advanced Controls Framework and Assessment of Enabling Technology Costs research describe a variety of DR opportunities and the various bulk power system services they can provide. The bulk power system services are mapped to a generalized taxonomy of DR “service types”, which allows us to discuss DR opportunities and bulk power system services in fewer yet broader categories that share similar technological requirements which mainly drive DR enablement costs. The research presents a framework for the costs to automate DR and provides descriptions of the various elements that drive enablement costs. The report introduces the various DR enabling technologies and end-uses, identifies the various services that each can provide to the grid and provides the cost assessment for each enabling technology. In addition to a report, this research includes a Demand Response Advanced Controls Database and User Manual. They are intended to provide users with the data that underlies this research and instructions for how to use that database more effectively and efficiently.

  9. Supply and Demand Control of Distributed Generators in a Microgrid for New Energy

    Science.gov (United States)

    Shimakage, Toyonari; Sumita, Jiro; Uchiyama, Noriyuki; Kato, Takeyoshi; Suzuoki, Yasuo

    We report the operational results of distributed generators (DGs) in a microgrid and present the effects after incorporating photovoltaic power generation (PV) systems into the microgrid for electric power system. The microgrid was constructed at the EXPO 2005 Aichi site as part of a demonstration promoted by NEDO. A solution is needed to problems where instability in the DGs that utilize natural energy such as solar light and wind force negatively influence existing electric power systems. So, we developed energy control system and controlled DGs output to reduce the fluctuation at the grid connected point caused by PV system's instability output. Our microgrid consists of DGs such as PV systems, fuel cells, and NaS batteries, and these DGs are controlled by an energy control system. We verified practical effectiveness of the installing the microgrid as follows. (1) 99.5% of the power imbalance in the supply and demand over 30 minutes was within a range of ±3% under normal operating conditions, (2) the microgrid contributes to the load leveling, (3) energy control system smoothes the power flow fluctuation of PV system output at the grid connected point, (4) in the future, installing a microgrid will help reduce the additional LFC (Load Frequency Control) capacity.

  10. Demand Controlled Economizer Cycles: A Direct Digital Control Scheme for Heating, Ventilating, and Air Conditioning Systems,

    Science.gov (United States)

    1984-05-01

    Control Ignored any error of 1/10th degree or less. This was done by setting the error term E and the integral sum PREINT to zero If then absolute value of...signs of two errors jeq tdiff if equal, jump clr @preint else zero integal sum tdiff mov @diff,rl fetch absolute value of OAT-RAT ci rl,25 is...includes a heating coil and thermostatic control to maintain the air in this path at an elevated temperature, typically around 80 degrees Farenheit (80 F

  11. Interaction between demand-control and social support in the occurrence of common mental disorders.

    Science.gov (United States)

    Mattos, Amália Ivine Santana; Araújo, Tânia Maria de; Almeida, Maura Maria Guimarães de

    2017-05-15

    To analyze the interaction between the psychosocial aspects of work and the occurrence of common mental disorders among health workers. This is a cross-sectional study conducted with a representative sample of workers of the primary health care of five municipalities of the State of Bahia, Brazil, in 2012. The variable of outcome were the common mental disorders evaluated by the SRQ-20, and the variables of exposure were high demand (high psychological demand and low control over the work) and low social support in the workplace. Interaction was checked by the deviation of the additivity of the effects for the factors studied from the calculation of excess risk from interaction, proportion of cases attributed to interaction, and the synergy index. The global prevalence of common mental disorders was 21%. The group of combined exposure has shown higher magnitude (high demand and low social support), reaching 28% when compared to the 17% in the situation of no exposure (low demand and high social support). The results strengthen the hypothesis of interaction between the factors investigated, directing to the synergy of the effects. Analisar a interação entre aspectos psicossociais do trabalho e a ocorrência de transtornos mentais comuns entre trabalhadores da saúde. Estudo transversal conduzido em amostra representativa de trabalhadores da atenção básica de cinco municípios da Bahia em 2012. As variáveis desfecho foram os transtornos mentais comuns avaliados pelo SRQ-20, as de exposição foram a alta exigência (alta demanda psicológica e baixo controle sobre o próprio trabalho) e o baixo apoio social no trabalho. A interação foi verificada pelo afastamento da aditividade dos efeitos para fatores estudados a partir do cálculo do excesso de risco devido à interação, proporção de casos atribuída à interação e índice de sinergia. A prevalência global de transtornos mentais comuns foi de 21%. Apresentou maior magnitude no grupo de exposi

  12. Interactive associations of parental support, demands, and psychological control, over adolescents' beliefs about the legitimacy of parental authority.

    Science.gov (United States)

    Mellado, Carlos; Cumsille, Patricio; Martínez, M Loreto

    2018-04-01

    The present study examined the relationship between parental support, demand, psychological control and adolescents' beliefs about the legitimacy of parental authority for personal and multifaceted issues in a sample of 1342 Chilean adolescents (M = 16.38, SD = 1.24, age range 14-20). Results from multiple regression analyses separated by age indicated that demand was positively associated with adolescents' beliefs about the legitimacy of parental authority for personal and multifaceted issues and that psychological control was negatively associated with adolescents' legitimacy beliefs concerning personal issues. Furthermore, parental support moderated the relationship between parental demand and adolescents' beliefs about parental legitimacy for personal and multifaceted issues: those who display high levels of demand showed stronger beliefs about parental legitimacy at high level of support. These results support the interactive effect of parental support and demand on adolescent development. Copyright © 2018. Published by Elsevier Ltd.

  13. A Closed-Loop Control Strategy for Air Conditioning Loads to Participate in Demand Response

    Directory of Open Access Journals (Sweden)

    Xiaoqing Hu

    2015-08-01

    Full Text Available Thermostatically controlled loads (TCLs, such as air conditioners (ACs, are important demand response resources—they have a certain heat storage capacity. A change in the operating status of an air conditioner in a small range will not noticeably affect the users’ comfort level. Load control of TCLs is considered to be equivalent to a power plant of the same capacity in effect, and it can significantly reduce the system pressure to peak load shift. The thermodynamic model of air conditioning can be used to study the aggregate power of a number of ACs that respond to the step signal of a temperature set point. This paper analyzes the influence of the parameters of each AC in the group to the indoor temperature and the total load, and derives a simplified control model based on the two order linear time invariant transfer function. Then, the stability of the model and designs its Proportional-Integral-Differential (PID controller based on the particle swarm optimization (PSO algorithm is also studied. The case study presented in this paper simulates both scenarios of constant ambient temperature and changing ambient temperature to verify the proposed transfer function model and control strategy can closely track the reference peak load shifting curves. The study also demonstrates minimal changes in the indoor temperature and the users’ comfort level.

  14. Dynamic postural control and associated attentional demands in contemporary dancers versus non-dancers.

    Science.gov (United States)

    Sirois-Leclerc, Geneviève; Remaud, Anthony; Bilodeau, Martin

    2017-01-01

    Postural control is not a fully automatic process, but requires a certain level of attention, particularly as the difficulty of the postural task increases. This study aimed at testing whether experienced contemporary dancers, because of their specialized training involving the control of posture/balance, would present with a dual-task performance suggesting lesser attentional demands associated with dynamic postural control compared with non-dancers. Twenty dancers and 16 non-dancers performed a dynamic postural tracking task in both antero-posterior and side-to-side directions, while standing on a force platform. The postural task was performed, in turn, 1) as a stand-alone task, and concurrently with both 2) a simple reaction time task and 3) a choice reaction time task. Postural control performance was estimated through variables calculated from centre of pressure movements. Although no overall group difference was found in reaction time values, we found a better ability to control the side to side movements of the centre of pressure during the tracking task in dancers compared with non-dancers, which was dependent on the secondary task. This suggests that such increased ability is influenced by available attentional resources.

  15. Dynamic postural control and associated attentional demands in contemporary dancers versus non-dancers.

    Directory of Open Access Journals (Sweden)

    Geneviève Sirois-Leclerc

    Full Text Available Postural control is not a fully automatic process, but requires a certain level of attention, particularly as the difficulty of the postural task increases. This study aimed at testing whether experienced contemporary dancers, because of their specialized training involving the control of posture/balance, would present with a dual-task performance suggesting lesser attentional demands associated with dynamic postural control compared with non-dancers. Twenty dancers and 16 non-dancers performed a dynamic postural tracking task in both antero-posterior and side-to-side directions, while standing on a force platform. The postural task was performed, in turn, 1 as a stand-alone task, and concurrently with both 2 a simple reaction time task and 3 a choice reaction time task. Postural control performance was estimated through variables calculated from centre of pressure movements. Although no overall group difference was found in reaction time values, we found a better ability to control the side to side movements of the centre of pressure during the tracking task in dancers compared with non-dancers, which was dependent on the secondary task. This suggests that such increased ability is influenced by available attentional resources.

  16. The extent to which ATP demand controls the glycolytic flux depends strongly on the organism and conditions for growth

    DEFF Research Database (Denmark)

    Købmann, Brian Jensen; Westerhoff, H.V.; Snoep, J.L.

    2002-01-01

    Using molecular genetics we have introduced uncoupled ATPase activity in two different bacterial species, Escherichia coli and Lactococcus lactis, and determined the elasticities of the growth rate and glycolytic flux towards the intracellular [ATP]/[ADP] ratio. During balanced growth in batch...... cultures of E. coli the ATP demand was found to have almost full control on the glycolytic flux (FCC=0.96) and the flux could be stimulated by 70%. In contrast to this, in L. lactis the control by ATP demand on the glycolytic flux was close to zero. However, when we used non-growing cells of L. lactis...... (which have a low glycolytic flux) the ATP demand had a high flux control and the flux could be stimulated more than two fold. We suggest that the extent to which ATP demand controls the glycolytic flux depends on how much excess capacity of glycolysis is present in the cells....

  17. The Effect of Job Demand-Control-Social Support Model on Nurses' Job Satisfaction in Specialized Teaching Hospitals, Ethiopia

    OpenAIRE

    Negussie, Nebiat; Kaur, Geetinder

    2016-01-01

    Background The job demand-control-social support model has been widely studied in western countries but has not been theoretically addressed on health workers of sub-Saharan African countries. Therefore, this study investigates the relationship between Job Demand-Control-Support Model and job satisfaction in specialized teaching hospitals in Ethiopia. Method A cross-sectional survey was conducted from September 2014 to May 2015 in three public specialized teaching hospitals in Ethiopia. Among...

  18. Renewable generation and demand response integration in micro-grids. Development of a new energy management and control system

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez-Bel, C.; Escriva-Escriva, G.; Alcazar-Ortega, M. [Institute for Energy Engineering, Universitat Politecnica de Valencia, Valencia (Spain)

    2013-11-15

    The aim of this research resides in the development of an energy management and control system to control a micro-grid based on the use of renewable generation and demand resources to introduce the application of demand response concepts to the management of micro-grids in order to effectively integrate the demand side as an operation resource for the grid and improve energy efficiency of the elements. As an additional result, the evaluation of reductions in the total amount of CO2 emitted into the atmosphere due to the improvement of the energy efficiency of the system is assessed.

  19. Fast-responsive hydrogel as an injectable pump for rapid on-demand fluidic flow control.

    Science.gov (United States)

    Luo, Rongcong; Dinh, Ngoc-Duy; Chen, Chia-Hung

    2017-05-01

    Chemically synthesized functional hydrogels have been recognized as optimized soft pumps for on-demand fluidic regulation in micro-systems. However, the challenges regarding the slow responses of hydrogels have very much limited their application in effective fluidic flow control. In this study, a heterobifunctional crosslinker (4-hydroxybutyl acrylate)-enabled two-step hydrothermal phase separation process for preparing a highly porous hydrogel with fast response dynamics was investigated for the fabrication of novel microfluidic functional units, such as injectable valves and pumps. The cylinder-shaped hydrogel, with a diameter of 9 cm and a height of 2.5 cm at 25 °C, achieved a size reduction of approximately 70% in less than 30 s after the hydrogels were heated at 40 °C. By incorporating polypyrrole nanoparticles as photothermal transducers, a photo-responsive composite hydrogel was approached and exhibited a remotely triggerable fluidic regulation and pumping ability to generate significant flows, showing on-demand water-in-oil droplet generation by laser switching, whereby the droplet size could be tuned by adjusting the laser intensity and irradiation period with programmable manipulation.

  20. A hard day's night: a longitudinal study on the relationships among job demands and job control, sleep quality and fatigue.

    Science.gov (United States)

    de Lange, Annet H; Kompier, Michiel A J; Taris, Toon W; Geurts, Sabine A E; Beckers, Debby G J; Houtman, Irene L D; Bongers, Paulien M

    2009-09-01

    This prospective four-wave study examined (i) the causal direction of the longitudinal relations among job demands, job control, sleep quality and fatigue; and (ii) the effects of stability and change in demand-control history on the development of sleep quality and fatigue. Based on results of a four-wave complete panel study among 1163 Dutch employees, we found significant effects of job demands and job control on sleep quality and fatigue across a 1-year time lag, supporting the strain hypothesis (Demand-Control model; Karasek and Theorell, Basic Books, New York, 1990). No reversed or reciprocal causal patterns were detected. Furthermore, our results revealed that cumulative exposure to a high-strain work environment (characterized by high job demands and low job control) was associated with elevated levels of sleep-related complaints. Cumulative exposure to a low-strain work environment (i.e. low job demands and high job control) was associated with the highest sleep quality and lowest level of fatigue. Our results revealed further that changes in exposure history were related to changes in reported sleep quality and fatigue across time. As expected, a transition from a non-high-strain towards a high-strain job was associated with a significant increase in sleep-related complaints; conversely, a transition towards a non-high-strain job was not related to an improvement in sleep-related problems.

  1. Snack purchasing is healthier when the cognitive demands of choice are reduced: A randomized controlled trial.

    Science.gov (United States)

    Allan, Julia L; Johnston, Marie; Campbell, Neil

    2015-07-01

    Individuals with inefficient executive (higher level cognitive) function have a reduced ability to resist dietary temptation. The present study aimed to design and test a theory-based point-of-purchase intervention for coffee shops that reduced the calorie content of customers' purchases by reducing the need for executive function (EF) at the moment of choice. Key facets of EF were identified by a multidisciplinary group and used to develop a point-of-purchase intervention (signage). This intervention was evaluated in a randomized controlled trial (RCT) in a public coffee shop on consumer purchases of >20,000 snacks and drinks over 12 weeks. A sample of customers (n = 128) was recruited to complete an embedded cross-sectional study measuring EF strength, dietary intentions, typical purchases, and purchases made after exposure to the intervention. The proportion of snack purchases that were high in calorie reduced significantly (t(10) = 2.34, p = .04) in intervention weeks relative to control. High calorie drink purchases were also lower in intervention than control weeks, however, this difference was not significant (t(10) = 1.56, p = .15). On average, customers purchased items containing 66 calories customer behavior increased as EF strength decreased (β = .24, p = .03). The calorie content of cafe purchases can be lowered by reducing the cognitive demands of healthy food choice at the moment of purchase, especially in those with poor EF. Environmental changes like these have the potential to help achieve population weight control. (c) 2015 APA, all rights reserved.

  2. Association between job strain (high demand-low control and cardiovascular disease risk factors among petrochemical industry workers

    Directory of Open Access Journals (Sweden)

    Siamak Poorabdian

    2013-08-01

    Full Text Available Objective: One of the practical models for assessment of stressful working conditions due to job strain is "job demand and control" or Karasek's job strain model. This model explains how adverse physical and psychological effects including cardiovascular disease risk factors can be established due to high work demand. The aim was to investigate how certain cardiovascular risk factors including body mass index (BMI, heart rate, blood pressure, serum total cholesterol levels, and cigarette smoking are associated with job demand and control in workers. Materials and Methods: In this cohort study, 500 subjects completed "job demand and control" questionnaires. Factor analysis method was used in order to specify the most important "job demand and control" questions. Health check-up records of the workers were applied to extract data about cardiovascular disease risk factors. Ultimately, hypothesis testing, based on Eta, was used to assess the relationship between separated working groups and cardiovascular risk factors (hypertension and serum total cholesterol level. Results: A significant relationship was found between the job demand-control model and cardiovascular risk factors. In terms of chisquared test results, the highest value was assessed for heart rate (Chi2 = 145.078. The corresponding results for smoking and BMI were Chi2 = 85.652 and Chi2 = 30.941, respectively. Subsequently, Eta result for total cholesterol was 0.469, followed by hypertension equaling 0.684. Moreover, there was a significant difference between cardiovascular risk factors and job demand-control profiles among different working groups including the operational group, repairing group and servicing group. Conclusion: Job control and demand are significantly related to heart disease risk factors including hypertension, hyperlipidemia, and cigarette smoking.

  3. Predictive Control of a Domestic Freezer for Real-Time Demand Response Applications

    NARCIS (Netherlands)

    Baghina, N.G.; Lampropoulos, I.; Asare-Bediako, B.; Kling, W.L.; Ribeiro, P.F.

    2012-01-01

    Demand side management and demand response aim to maximize the efficiency of the electricity delivery process by exploiting the flexibility of customers. At residential level, demand response can be applied only to a limited number of appliances, through load management, due to user intervention or

  4. Time management behavior as a moderator for the job demand-control interaction

    NARCIS (Netherlands)

    Peeters, M.A.G.; Rutte, C.G.

    2005-01-01

    The interaction effects of time management, work demands, and autonomy on burnout were investigated in a survey study of 123 elementary teachers. A 3-way interaction between time management, work demands, and autonomy was hypothesized: The combination of high work demands and low autonomy was

  5. Impact of thermostatically controlled loads' demand response activation on aggregated power: A field experiment

    DEFF Research Database (Denmark)

    Lakshmanan, Venkatachalam; Marinelli, Mattia; Kosek, Anna Magdalena

    2015-01-01

    activation. The outcome of this experimental study quantifies the actual flexibility of household TCLs and the consequence for the different parties with respect to power behaviour. Each DR activation method adopts different scenarios to meet the power reduction, and has different impacts on the parameters......This paper describes the impacts of different types of DR (demand response) activation on TCLs' (thermostatically controlled loads) aggregated power. The different parties: power system operators, DR service providers (or aggregators) and consumers, have different objectives in relation to DR....... The experiments are conducted with real domestic refrigerators representing TCL. Activating refrigerators for DR with a delay reduces the ISE (integral square error) in power limitation by 28.46%, overshoot by 7.69%. The delay in refrigerator activation causes reduction in power ramp down rate by 39.90%, ramp up...

  6. On-demand semiconductor source of 780-nm single photons with controlled temporal wave packets

    Science.gov (United States)

    Béguin, Lucas; Jahn, Jan-Philipp; Wolters, Janik; Reindl, Marcus; Huo, Yongheng; Trotta, Rinaldo; Rastelli, Armando; Ding, Fei; Schmidt, Oliver G.; Treutlein, Philipp; Warburton, Richard J.

    2018-05-01

    We report on a fast, bandwidth-tunable single-photon source based on an epitaxial GaAs quantum dot. Exploiting spontaneous spin-flip Raman transitions, single photons at 780 nm are generated on demand with tailored temporal profiles of durations exceeding the intrinsic quantum dot lifetime by up to three orders of magnitude. Second-order correlation measurements show a low multiphoton emission probability [g2(0 ) ˜0.10 -0.15 ] at a generation rate up to 10 MHz. We observe Raman photons with linewidths as low as 200 MHz, which is narrow compared to the 1.1-GHz linewidth measured in resonance fluorescence. The generation of such narrow-band single photons with controlled temporal shapes at the rubidium wavelength is a crucial step towards the development of an optimized hybrid semiconductor-atom interface.

  7. The effect of alternative work arrangements on women's well-being: a demand-control model.

    Science.gov (United States)

    Kelloway, E K; Gottlieb, B H

    1998-01-01

    The growth of women's participation in the labor force and evidence of the conflict they experience between job and family demands have spurred many employers to introduce alternative work arrangements such as flextime, job sharing, and telecommuting. Drawing on data gained from a sample of women (N = 998) in two large Canadian organizations, this study evaluates two mediational models of the impact of alternative work arrangements on women's stress and family role competence. Specifically, it tests and finds support for the hypotheses that (a) work arrangements involving scheduling flexibility (telecommuting and flextime) promote these aspects of women's well-being by increasing their perceived control over their time, and (b) arrangements involving reduced hours of employment (part-time employment and job sharing) promote well-being by reducing perceived job overload. Discussion of these findings centers on their implications for employed women, their employers, and future research.

  8. Field Testing of Telemetry for Demand Response Control of Small Loads

    Energy Technology Data Exchange (ETDEWEB)

    Lanzisera, Steven [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Weber, Adam [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Liao, Anna [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Schetrit, Oren [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kiliccote, Sila [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Piette, Mary Ann [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2018-01-30

    The electricity system in California, from generation through loads, must be prepared for high renewable penetration and increased electrification of end uses while providing increased resilience and lower operating cost. California has an aggressive renewable portfolio standard that is complemented by world-leading greenhouse gas goals. The goal of this project was to evaluate methods of enabling fast demand response (DR) signaling to small loads for low-cost site enablement. We used OpenADR 2.0 to meet telemetry requirements for providing ancillary services, and we used a variety of low-cost devices coupled with open-source software to enable an end-to-end fast DR. The devices, architecture, implementation, and testing of the system is discussed in this report. We demonstrate that the emerging Internet of Things (IoT) and Smart Home movements provide an opportunity for diverse small loads to provide fast, low-cost demand response. We used Internet-connected lights, thermostats, load interruption devices, and water heaters to demonstrate an ecosystem of controllable devices. The system demonstrated is capable of providing fast load shed for between 20 dollars and $300 per kilowatt (kW) of available load. The wide range results from some loads may have very low cost but also very little shed capability (a 10 watt [W] LED light can only shed a maximum of 10 W) while some loads (e.g., water heaters or air conditioners) can shed several kilowatts but have a higher initial cost. These costs, however, compare well with other fast demand response costs, with typically are over $100/kilowatt of shed. We contend these loads are even more attractive than their price suggests because many of them will be installed for energy efficiency or non-energy benefits (e.g., improved lighting quality or controllability), and the ability to use them for fast DR is a secondary benefit. Therefore the cost of enabling them for DR may approach zero if a software-only solution can be

  9. Expert ratings of job demand and job control as predictors of injury and musculoskeletal disorder risk in a manufacturing cohort.

    Science.gov (United States)

    Cantley, Linda F; Tessier-Sherman, Baylah; Slade, Martin D; Galusha, Deron; Cullen, Mark R

    2016-04-01

    To examine associations between workplace injury and musculoskeletal disorder (MSD) risk and expert ratings of job-level psychosocial demand and job control, adjusting for job-level physical demand. Among a cohort of 9260 aluminium manufacturing workers in jobs for which expert ratings of job-level physical and psychological demand and control were obtained during the 2 years following rating obtainment, multivariate mixed effects models were used to estimate relative risk (RR) of minor injury and minor MSD, serious injury and MSD, minor MSD only and serious MSD only by tertile of demand and control, adjusting for physical demand as well as other recognised risk factors. Compared with workers in jobs rated as having low psychological demand, workers in jobs with high psychological demand had 49% greater risk of serious injury and serious MSD requiring medical treatment, work restrictions or lost work time (RR=1.49; 95% CI 1.10 to 2.01). Workers in jobs rated as having low control displayed increased risk for minor injury and minor MSD (RR=1.45; 95% CI 1.12 to 1.87) compared with those in jobs rated as having high control. Using expert ratings of job-level exposures, this study provides evidence that psychological job demand and job control contribute independently to injury and MSD risk in a blue-collar manufacturing cohort, and emphasises the importance of monitoring psychosocial workplace exposures in addition to physical workplace exposures to promote worker health and safety. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  10. On-Demand Final State Control of a Surface-Bound Bistable Single Molecule Switch.

    Science.gov (United States)

    Garrido Torres, José A; Simpson, Grant J; Adams, Christopher J; Früchtl, Herbert A; Schaub, Renald

    2018-04-12

    Modern electronic devices perform their defined action because of the complete reliability of their individual active components (transistors, switches, diodes, and so forth). For instance, to encode basic computer units (bits) an electrical switch can be used. The reliability of the switch ensures that the desired outcome (the component's final state, 0 or 1) can be selected with certainty. No practical data storage device would otherwise exist. This reliability criterion will necessarily need to hold true for future molecular electronics to have the opportunity to emerge as a viable miniaturization alternative to our current silicon-based technology. Molecular electronics target the use of single-molecules to perform the actions of individual electronic components. On-demand final state control over a bistable unimolecular component has therefore been one of the main challenges in the past decade (1-5) but has yet to be achieved. In this Letter, we demonstrate how control of the final state of a surface-supported bistable single molecule switch can be realized. On the basis of the observations and deductions presented here, we further suggest an alternative strategy to achieve final state control in unimolecular bistable switches.

  11. Model-on-Demand Predictive Control for Nonlinear Hybrid Systems With Application to Adaptive Behavioral Interventions

    Science.gov (United States)

    Nandola, Naresh N.; Rivera, Daniel E.

    2011-01-01

    This paper presents a data-centric modeling and predictive control approach for nonlinear hybrid systems. System identification of hybrid systems represents a challenging problem because model parameters depend on the mode or operating point of the system. The proposed algorithm applies Model-on-Demand (MoD) estimation to generate a local linear approximation of the nonlinear hybrid system at each time step, using a small subset of data selected by an adaptive bandwidth selector. The appeal of the MoD approach lies in the fact that model parameters are estimated based on a current operating point; hence estimation of locations or modes governed by autonomous discrete events is achieved automatically. The local MoD model is then converted into a mixed logical dynamical (MLD) system representation which can be used directly in a model predictive control (MPC) law for hybrid systems using multiple-degree-of-freedom tuning. The effectiveness of the proposed MoD predictive control algorithm for nonlinear hybrid systems is demonstrated on a hypothetical adaptive behavioral intervention problem inspired by Fast Track, a real-life preventive intervention for improving parental function and reducing conduct disorder in at-risk children. Simulation results demonstrate that the proposed algorithm can be useful for adaptive intervention problems exhibiting both nonlinear and hybrid character. PMID:21874087

  12. Prefrontal cortex activation upon a demanding virtual hand-controlled task: a new frontier for neuroergonomics

    Directory of Open Access Journals (Sweden)

    Marika eCarrieri

    2016-02-01

    Full Text Available Functional near-infrared spectroscopy (fNIRS is a non-invasive vascular-based functional neuroimaging technology that can assess, simultaneously from multiple cortical areas, concentration changes in oxygenated-deoxygenated hemoglobin at the level of the cortical microcirculation blood vessels. fNIRS, with its high degree of ecological validity and its very limited requirement of physical constraints to subjects, could represent a valid tool for monitoring cortical responses in the research field of neuroergonomics. In virtual reality (VR real situations can be replicated with greater control than those obtainable in the real world. Therefore, VR is the ideal setting where studies about neuroergonomics applications can be performed. The aim of the present study was to investigate, by a 20-channel fNIRS system, the dorsolateral/ventrolateral prefrontal cortex (DLPFC/VLPFC in subjects while performing a demanding VR hand-controlled task (HCT. Considering the complexity of the HCT, its execution should require the attentional resources allocation and the integration of different executive functions. The HCT simulates the interaction with a real, remotely-driven, system operating in a critical environment. The hand movements were captured by a high spatial and temporal resolution 3D hand-sensing device, the LEAP motion controller, a gesture-based control interface that could be used in VR for tele-operated applications. Fifteen University students were asked to guide, with their right hand/forearm, a virtual ball (VB over a virtual route (VROU reproducing a 42-m narrow road including some critical points. The subjects tried to travel as long as possible without making VB fall. The distance traveled by the guided VB was 70.2±37.2 m. The less skilled subjects failed several times in guiding the VB over the VROU. Nevertheless, a bilateral VLPFC activation, in response to the HCT execution, was observed in all the subjects. No correlation was found

  13. Prefrontal Cortex Activation Upon a Demanding Virtual Hand-Controlled Task: A New Frontier for Neuroergonomics.

    Science.gov (United States)

    Carrieri, Marika; Petracca, Andrea; Lancia, Stefania; Basso Moro, Sara; Brigadoi, Sabrina; Spezialetti, Matteo; Ferrari, Marco; Placidi, Giuseppe; Quaresima, Valentina

    2016-01-01

    Functional near-infrared spectroscopy (fNIRS) is a non-invasive vascular-based functional neuroimaging technology that can assess, simultaneously from multiple cortical areas, concentration changes in oxygenated-deoxygenated hemoglobin at the level of the cortical microcirculation blood vessels. fNIRS, with its high degree of ecological validity and its very limited requirement of physical constraints to subjects, could represent a valid tool for monitoring cortical responses in the research field of neuroergonomics. In virtual reality (VR) real situations can be replicated with greater control than those obtainable in the real world. Therefore, VR is the ideal setting where studies about neuroergonomics applications can be performed. The aim of the present study was to investigate, by a 20-channel fNIRS system, the dorsolateral/ventrolateral prefrontal cortex (DLPFC/VLPFC) in subjects while performing a demanding VR hand-controlled task (HCT). Considering the complexity of the HCT, its execution should require the attentional resources allocation and the integration of different executive functions. The HCT simulates the interaction with a real, remotely-driven, system operating in a critical environment. The hand movements were captured by a high spatial and temporal resolution 3-dimensional (3D) hand-sensing device, the LEAP motion controller, a gesture-based control interface that could be used in VR for tele-operated applications. Fifteen University students were asked to guide, with their right hand/forearm, a virtual ball (VB) over a virtual route (VROU) reproducing a 42 m narrow road including some critical points. The subjects tried to travel as long as possible without making VB fall. The distance traveled by the guided VB was 70.2 ± 37.2 m. The less skilled subjects failed several times in guiding the VB over the VROU. Nevertheless, a bilateral VLPFC activation, in response to the HCT execution, was observed in all the subjects. No correlation was found

  14. Demand specifying variables and current ventilation rate requirements with respect to the future use of voc sensing for dcv control

    DEFF Research Database (Denmark)

    Kolarik, Jakub

    be also taken into account in the ventilation control. Recent development in gas sensing technology resulted in a new generation of relatively cheap and practically applicable sensors that can offer measurements of some of the pollutants mentioned above – mainly Volatile Organic Compounds (VOC......Demand Controlled Ventilation (DCV) is a well established principle to provide a certain indoor environmental quality, defined both in the terms of air quality and thermal comfort. This is accomplished by adjusting the supplied airflow rate according to a certain demand indicator, which......). This seems to bring a new dimension into the control of DCV systems. This paper is a contribution to the workshop on utilization of VOC sensing technology used for DCV control. The aim of the paper is to provide a short review of different types of demand variables used to control DCV systems and summarize...

  15. Peroxone mineralization of chemical oxygen demand for direct potable water reuse: Kinetics and process control.

    Science.gov (United States)

    Wu, Tingting; Englehardt, James D

    2015-04-15

    Mineralization of organics in secondary effluent by the peroxone process was studied at a direct potable water reuse research treatment system serving an occupied four-bedroom, four bath university residence hall apartment. Organic concentrations were measured as chemical oxygen demand (COD) and kinetic runs were monitored at varying O3/H2O2 dosages and ratios. COD degradation could be accurately described as the parallel pseudo-1st order decay of rapidly and slowly-oxidizable fractions, and effluent COD was reduced to below the detection limit (<0.7 mg/L). At dosages ≥4.6 mg L(-1) h(-1), an O3/H2O2 mass ratio of 3.4-3.8, and initial COD <20 mg/L, a simple first order decay was indicated for both single-passed treated wastewater and recycled mineral water, and a relationship is proposed and demonstrated to estimate the pseudo-first order rate constant for design purposes. At this O3/H2O2 mass ratio, ORP and dissolved ozone were found to be useful process control indicators for monitoring COD mineralization in secondary effluent. Moreover, an average second order rate constant for OH oxidation of secondary effluent organics (measured as MCOD) was found to be 1.24 × 10(7) ± 0.64 × 10(7) M(-1) S(-1). The electric energy demand of the peroxone process is estimated at 1.73-2.49 kW h electric energy for removal of one log COD in 1 m(3) secondary effluent, comparable to the energy required for desalination of medium strength seawater. Advantages/disadvantages of the two processes for municipal wastewater reuse are discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Hybrid LSA-ANN Based Home Energy Management Scheduling Controller for Residential Demand Response Strategy

    Directory of Open Access Journals (Sweden)

    Maytham S. Ahmed

    2016-09-01

    Full Text Available Demand response (DR program can shift peak time load to off-peak time, thereby reducing greenhouse gas emissions and allowing energy conservation. In this study, the home energy management scheduling controller of the residential DR strategy is proposed using the hybrid lightning search algorithm (LSA-based artificial neural network (ANN to predict the optimal ON/OFF status for home appliances. Consequently, the scheduled operation of several appliances is improved in terms of cost savings. In the proposed approach, a set of the most common residential appliances are modeled, and their activation is controlled by the hybrid LSA-ANN based home energy management scheduling controller. Four appliances, namely, air conditioner, water heater, refrigerator, and washing machine (WM, are developed by Matlab/Simulink according to customer preferences and priority of appliances. The ANN controller has to be tuned properly using suitable learning rate value and number of nodes in the hidden layers to schedule the appliances optimally. Given that finding proper ANN tuning parameters is difficult, the LSA optimization is hybridized with ANN to improve the ANN performances by selecting the optimum values of neurons in each hidden layer and learning rate. Therefore, the ON/OFF estimation accuracy by ANN can be improved. Results of the hybrid LSA-ANN are compared with those of hybrid particle swarm optimization (PSO based ANN to validate the developed algorithm. Results show that the hybrid LSA-ANN outperforms the hybrid PSO based ANN. The proposed scheduling algorithm can significantly reduce the peak-hour energy consumption during the DR event by up to 9.7138% considering four appliances per 7-h period.

  17. Inventory control for a perishable product with non-stationary demand and service level constraints

    NARCIS (Netherlands)

    Pauls-Worm, K.G.J.; Hendrix, E.M.T.; Haijema, R.; Vorst, van der J.G.A.J.

    2013-01-01

    We study the practical production planning problem of a food producer facing a non-stationary erratic demand for a perishable product with a fixed life time. In meeting the uncertain demand, the food producer uses a FIFO issuing policy. The food producer aims at meeting a certain service level at

  18. Work-related stress according to the demand-control model and minor psychic disorders in nursing workers

    Directory of Open Access Journals (Sweden)

    Janete de Souza Urbanetto

    2013-10-01

    Full Text Available This was a cross-sectional study that aimed to assess the association between work-related stress according to the Demand-Control Model, and the occurrence of Minor Psychic Disorder (MPD in nursing workers. The participants were 335 professionals, out of which 245 were nursing technicians, aged predominantly between 20 and 40 years. Data were collected using the Job Stress Scale and the Self-Reporting Questionnaire-20. The analysis was performed using descriptive and analytical statistics. The prevalence of suspected MPD was 20.6%. Workers classified in the quadrants active job and high strain of the Demand-Control Model presented higher potential for developing MPD compared with those classified in the quadrant low strain. In conclusion, stress affects the mental health of workers and the aspects related to high psychological demands and high control still require further insight in order to understand their influence on the disease processes of nursing workers.

  19. Quantifying demand flexibility of power-to-heat and thermal energy storage in the control of building heating systems

    DEFF Research Database (Denmark)

    Finck, Christian; Li, Rongling; Kramer, Rick

    2018-01-01

    restricted by power-to-heat conversion such as heat pumps and thermal energy storage possibilities of a building. To quantify building demand flexibility, it is essential to capture the dynamic response of the building energy system with thermal energy storage. To identify the maximum flexibility a building......’s energy system can provide, optimal control is required. In this paper, optimal control serves to determine in detail demand flexibility of an office building equipped with heat pump, electric heater, and thermal energy storage tanks. The demand flexibility is quantified using different performance...... of TES and power-to-heat in any case of charging, discharging or idle mode. A simulation case study is performed showing that a water tank, a phase change material tank, and a thermochemical material tank integrated with building heating system can be designed to provide flexibility with optimal control....

  20. Policy of energy demand control and resistance to change. A socio-anthropological approach

    International Nuclear Information System (INIS)

    Zelem, Marie-Christine

    2010-03-01

    The development of energy consuming devices, the growth of electricity consumptions, the exhaustion of fossil fuels and the increase of greenhouse gases are as many factors that contribute to the acceleration of global warming. The control of energy demand is one of the levers to influence the energy-consuming behaviours. What are such policies made of? What instruments are used and with what efficiency? What population is targeted? Using some practical examples taken in the everyday life, the first part of this book shows how professionals and consumers are reticent to change their habits, equipments and know-how, and why they have very good reasons to do so. The second part of the book treats of incentive systems and shows that they very often have problems with finding a public. The different energy saving awareness campaigns show the importance of the preliminary building of an energy saving culture to make energy saving policies efficient and socially acceptable. The next part deals with the experience gained from the energy efficiency programs implemented in Quebec and in French Guyana. In both cases, the public information tools are adapted to the culture of the targeted populations. The last part reviews some paths to explore to durably change the behaviours. (J.S.)

  1. Controlling the demand for electricity: strategies and challenges in the residential sector of the OECD countries

    International Nuclear Information System (INIS)

    Lebot, B.

    2003-01-01

    By reinforcing policies to improve the energy efficiency of household appliances (particularly by rating the efficiency of each appliance as a minimum of its overall cost from 2005 onwards), the member countries of the IEA are in a position to reduce their annual CO 2 emissions by approximately 322 million tonnes (Mt) by 2010, compared to what they would have obtained using current policies. In 2030, this same policy will make it possible to achieve an annual saving of 1 110 TWh in the consumption of electricity, (572 Mt of CO 2 each year). This measure alone will meet 30% of the objectives of the member countries of the IEA under the Kyoto agreements concerning climatic change. These reductions can be obtained at a negative cost for society as the additional cost generated by improvements in energy efficiency is offset by savings made in operating costs during the life of the appliance. Thus, in the United States, each tonne of CO 2 saved in this way in 2020 will generate $65 for society. In Europe, every tonne of CO 2 saved will generate a gain of euros 169 (the difference being accounted for by the higher cost of electricity and by lower energy efficiency standards currently existing in Europe). It is possible to make major savings in all regions of the OECD, despite the vast diversity of the various situations of the countries. In the member countries of the IEA, the policies in place have already demonstrated their economic effectiveness in reducing demand for energy and greenhouse gas emissions. Up to 2000, they made it possible to reduce greenhouse gas emissions by approximately 46 Mt of CO 2 each year. These policies will contribute to reducing emissions by 126 Mt of CO 2 each year up to 2010. International co-operation offers real advantages in the deployment of policies for controlling the demand for energy by households. Manufacturers, consumers and governments all benefit from greater transparency in the marketplace, improved comparisons of test methods

  2. Professional efficacy, exhaustion, and work characteristics among police officers: A longitudinal test of the learning-related predictions of the demand-control model

    NARCIS (Netherlands)

    Taris, T.W.; Kompier, M.A.J.; Geurts, S.A.E.; Houtman, I.L.D.; Heuvel, F.F.M. van den

    2010-01-01

    The present study addressed the relationships among professional efficacy, emotional exhaustion, and job characteristics (job demands and job control) in the context of a two-wave panel study among 828 Dutch police officers. Based on the demand-control model, we expected that high demands/high

  3. Physical activity, job demand-control, perceived stress-energy, and salivary cortisol in white-collar workers

    DEFF Research Database (Denmark)

    Hansen, Åse Marie; Blangsted, Anne Katrine; Hansen, Ernst Albin

    2010-01-01

    The aim of the present study is to examine the association between physical activity and perceived job demand, job control, perceived stress and energy, and physiological arousal reflected by morning and evening concentrations of cortisol in saliva among white-collar workers.......The aim of the present study is to examine the association between physical activity and perceived job demand, job control, perceived stress and energy, and physiological arousal reflected by morning and evening concentrations of cortisol in saliva among white-collar workers....

  4. Time management behavior as a moderator for the job demand-control interaction.

    Science.gov (United States)

    Peeters, Miranda A G; Rutte, Christel G

    2005-01-01

    The interaction effects of time management, work demands, and autonomy on burnout were investigated in a survey study of 123 elementary teachers. A 3-way interaction between time management, work demands, and autonomy was hypothesized: The combination of high work demands and low autonomy was predicted to lead to burnout for teachers low in time management and not, or to a lesser extent, for those high in time management. This hypothesis is confirmed for emotional exhaustion, the most predictive dimension of teacher burnout, and partly confirmed for the personal accomplishment dimension. Generalizability to other contactual occupations is discussed. ((c) 2005 APA, all rights reserved).

  5. Individual Characteristics Influencing Physicians’ Perceptions of Job Demands and Control: The Role of Affectivity, Work Engagement and Workaholism

    Directory of Open Access Journals (Sweden)

    Greta Mazzetti

    2016-06-01

    Full Text Available The first purpose of the present study was to investigate the role of individual characteristics, i.e., positive and negative affectivity, in explaining the different perception of job control and job demands in a particularly demanding environment such as the healthcare setting. In addition, we aimed to explore the mediational role of work engagement and workaholism using the Job Demands-Resources Model as a theoretical framework. Data were collected using a sample of 269 Italian head physicians working in nine general hospitals. To test our hypotheses, the collected data were analyzed with structural equation modeling. Moreover, Sobel Test and bootstrapping were employed to assess the mediating hypotheses. Our results indicated that positive affectivity is related to work engagement, which, in its turn, showed a positive association with job control. In addition, workaholism mediated the relationship between negative affectivity and job demands. All in all, this study represents a first attempt to explore the role of trait affectivity as a dispositional characteristic able to foster the level of work engagement and workaholism exhibited by employees and, in turn, to increase the perceived levels of job control and job demands.

  6. Individual Characteristics Influencing Physicians' Perceptions of Job Demands and Control: The Role of Affectivity, Work Engagement and Workaholism.

    Science.gov (United States)

    Mazzetti, Greta; Biolcati, Roberta; Guglielmi, Dina; Vallesi, Caryn; Schaufeli, Wilmar B

    2016-06-06

    The first purpose of the present study was to investigate the role of individual characteristics, i.e., positive and negative affectivity, in explaining the different perception of job control and job demands in a particularly demanding environment such as the healthcare setting. In addition, we aimed to explore the mediational role of work engagement and workaholism using the Job Demands-Resources Model as a theoretical framework. Data were collected using a sample of 269 Italian head physicians working in nine general hospitals. To test our hypotheses, the collected data were analyzed with structural equation modeling. Moreover, Sobel Test and bootstrapping were employed to assess the mediating hypotheses. Our results indicated that positive affectivity is related to work engagement, which, in its turn, showed a positive association with job control. In addition, workaholism mediated the relationship between negative affectivity and job demands. All in all, this study represents a first attempt to explore the role of trait affectivity as a dispositional characteristic able to foster the level of work engagement and workaholism exhibited by employees and, in turn, to increase the perceived levels of job control and job demands.

  7. Access control infrastructure for on-demand provisioned virtualised infrastructure services

    NARCIS (Netherlands)

    Demchenko, Y.; Ngo, C.; de Laat, C.; Smari, W.W.; Fox, G.C.

    2011-01-01

    Cloud technologies are emerging as a new way of provisioning virtualised computing and infrastructure services on-demand for collaborative projects and groups. Security in provisioning virtual infrastructure services should address two general aspects: supporting secure operation of the provisioning

  8. The influence of an auditory-memory attention-demanding task on postural control in blind persons.

    Science.gov (United States)

    Melzer, Itshak; Damry, Elad; Landau, Anat; Yagev, Ronit

    2011-05-01

    In order to evaluate the effect of an auditory-memory attention-demanding task on balance control, nine blind adults were compared to nine age-gender-matched sighted controls. This issue is particularly relevant for the blind population in which functional assessment of postural control has to be revealed through "real life" motor and cognitive function. The study aimed to explore whether an auditory-memory attention-demanding cognitive task would influence postural control in blind persons and compare this with blindfolded sighted persons. Subjects were instructed to minimize body sway during narrow base upright standing on a single force platform under two conditions: 1) standing still (single task); 2) as in 1) while performing an auditory-memory attention-demanding cognitive task (dual task). Subjects in both groups were required to stand blindfolded with their eyes closed. Center of Pressure displacement data were collected and analyzed using summary statistics and stabilogram-diffusion analysis. Blind and sighted subjects had similar postural sway in eyes closed condition. However, for dual compared to single task, sighted subjects show significant decrease in postural sway while blind subjects did not. The auditory-memory attention-demanding cognitive task had no interference effect on balance control on blind subjects. It seems that sighted individuals used auditory cues to compensate for momentary loss of vision, whereas blind subjects did not. This may suggest that blind and sighted people use different sensorimotor strategies to achieve stability. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. Do high job demands increase intrinsic motivation or fatigue or both? The role of job control and job social support

    NARCIS (Netherlands)

    Van Yperen, N.W.; Hagedoorn, M.

    2003-01-01

    Examined whether job control and job social support reduce signs of fatigue and enhance intrinsic motivation among employees facing high job demands. 555 nurses (mean age 35.5 yrs) working at specialized units for patients with different levels of mental deficiency completed surveys regarding: (1)

  10. Salivary a-Amylase Reflects Change in Attentional Demands during Postural Control: Comparison with Probe Reaction Time

    Science.gov (United States)

    Akizuki, Kazunori; Ohashi, Yukari

    2014-01-01

    Purpose: The influence of attention on postural control and the relationship between attention and falling has been reported in previous studies. Although a dual-task procedure is commonly used to measure attentional demand, such procedures are affected by allocation policy, which is a mental strategy to divide attention between simultaneous…

  11. Job characteristics and safety climate: the role of effort-reward and demand-control-support models.

    Science.gov (United States)

    Phipps, Denham L; Malley, Christine; Ashcroft, Darren M

    2012-07-01

    While safety climate is widely recognized as a key influence on organizational safety, there remain questions about the nature of its antecedents. One potential influence on safety climate is job characteristics (that is, psychosocial features of the work environment). This study investigated the relationship between two job characteristics models--demand-control-support (Karasek & Theorell, 1990) and effort-reward imbalance (Siegrist, 1996)--and safety climate. A survey was conducted with a random sample of 860 British retail pharmacists, using the job contents questionnaire (JCQ), effort-reward imbalance indicator (ERI) and a measure of safety climate in pharmacies. Multivariate data analyses found that: (a) both models contributed to the prediction of safety climate ratings, with the demand-control-support model making the largest contribution; (b) there were some interactions between demand, control and support from the JCQ in the prediction of safety climate scores. The latter finding suggests the presence of "active learning" with respect to safety improvement in high demand, high control settings. The findings provide further insight into the ways in which job characteristics relate to safety, both individually and at an aggregated level.

  12. Structuring energy supply and demand networks in a general equilibrium model to simulate global warming control strategies

    International Nuclear Information System (INIS)

    Hamilton, S.; Veselka, T.D.; Cirillo, R.R.

    1991-01-01

    Global warming control strategies which mandate stringent caps on emissions of greenhouse forcing gases can substantially alter a country's demand, production, and imports of energy products. Although there is a large degree of uncertainty when attempting to estimate the potential impact of these strategies, insights into the problem can be acquired through computer model simulations. This paper presents one method of structuring a general equilibrium model, the ENergy and Power Evaluation Program/Global Climate Change (ENPEP/GCC), to simulate changes in a country's energy supply and demand balance in response to global warming control strategies. The equilibrium model presented in this study is based on the principle of decomposition, whereby a large complex problem is divided into a number of smaller submodules. Submodules simulate energy activities and conversion processes such as electricity production. These submodules are linked together to form an energy supply and demand network. Linkages identify energy and fuel flows among various activities. Since global warming control strategies can have wide reaching effects, a complex network was constructed. The network represents all energy production, conversion, transportation, distribution, and utilization activities. The structure of the network depicts interdependencies within and across economic sectors and was constructed such that energy prices and demand responses can be simulated. Global warming control alternatives represented in the network include: (1) conservation measures through increased efficiency; and (2) substitution of fuels that have high greenhouse gas emission rates with fuels that have lower emission rates. 6 refs., 4 figs., 4 tabs

  13. The Job Demands-Job Control Model and absence behaviour : results of a 3-year longitudinal study

    NARCIS (Netherlands)

    Smulders, P.G.W.; Nijhuis, F.J.N.

    1999-01-01

    Empirical results of earlier studies only marginally supported the relevance of Karasek's Job Demands-Job Control Model for absence behaviour. Since longitudinal studies with respect to these relations were largely lacking, a four-wave panel study was carried out using data from 1755 male employees

  14. A novel algorithm for demand-control of a single-room ventilation unit with a rotary heat exchanger

    DEFF Research Database (Denmark)

    Smith, Kevin Michael; Jansen, Anders Lund; Svendsen, Svend

    in the indoor environment. Based on these values, a demand-control algorithm varies fan speeds to change airflow rates and varies the rotational speed of the heat exchanger to modulate heat and moisture recovery. The algorithm varies airflow rates to provide free cooling and limit CO2 concentrations and varies...... moisture recovery by varying the rotational speed and then safely unbalances airflows in a worst-case scenario. In the algorithm, frost protection and minimum supply temperature take the highest priority and override other controls. This paper documents the proposed demand control algorithm and analyses...... its impacts on compliance of building regulations in Denmark. The paper presents an algorithm that manufacturers can program into their controls. The commercially available single-room ventilation unit with a rotary heat exchanger uses this algorithm coded in the C language. Future work will document...

  15. Gender Differences in the Effects of Job Control and Demands on the Health of Korean Manual Workers.

    Science.gov (United States)

    Kim, HeeJoo; Kim, Ji Hye; Jang, Yeon Jin; Bae, Ji Young

    2016-01-01

    We used the job-demand-control model to answer our two research questions concerning the effects of working conditions on self-rated health and gender differences and the association between these working conditions and health among Korean manual workers. Since a disproportionate representation of women in nonstandard work positions is found in many countries, including Korea, it is important to examine how working conditions explain gender inequality in health. We used data from the 2008-2009 Korean National Health and Nutrition Examination Survey and analyzed a total sample of 1,482 men and 1,350 women using logistic regression. We found that job control was positively related to self-rated health, while both physical and mental job demands were negatively related to self-rated health. We also found significant interaction effects of job demands, control, and gender on health. Particularly, female workers' health was more vulnerable to mentally demanding job conditions. We discussed theoretical and practice implications based on these findings.

  16. Job Demand and Control Interventions: A Stakeholder-Centered Best-Evidence Synthesis of Systematic Reviews on Workplace Disability

    Directory of Open Access Journals (Sweden)

    K Williams-Whitt

    2015-04-01

    Full Text Available Background: Physical and psychological job demands in combination with the degree of control a worker has over task completion, play an important role in reducing stress. Occupational stress is an important, modifiable factor affecting work disability. However, the effectiveness of reducing job demands or increasing job control remains unclear, particularly for outcomes of interest to employers, such as absenteeism or productivity. Objective: This systematic review reports on job demand and control interventions that impact absenteeism, productivity and financial outcomes. Methods: A stakeholder-centered best-evidence synthesis was conducted with researcher and stakeholder collaboration throughout. Databases and grey literature were searched for systematic reviews between 2000 and 2012: Medline, EMBASE, the Cochrane Database of Systematic Reviews, DARE, CINAHL, PsycINFO, TRIP, health-evidence.ca, Rehab+, National Rehabilitation Information Center (NARIC, and Institute for Work and Health. Articles were assessed independently by two researchers for inclusion criteria and methodological quality. Differences were resolved through consensus. Results: The search resulted in 3363 unique titles. After review of abstracts, 115 articles were retained for full-text review. 11 articles finally met the inclusion criteria and are summarized in this synthesis. The best level of evidence we found indicates that multimodal job demand reductions for either at-work or off-work workers will reduce disability-related absenteeism. Conclusion: In general, the impacts of interventions that aim to reduce job demands or increase job control can be positive for the organization in terms of reducing absenteeism, increasing productivity and cost-effectiveness. However, more high quality research is needed to further assess the relationships and quantify effect sizes for the interventions and outcomes reviewed in this study.

  17. Job demand and control interventions: a stakeholder-centered best-evidence synthesis of systematic reviews on workplace disability.

    Science.gov (United States)

    Williams-Whitt, K; White, M I; Wagner, S L; Schultz, I Z; Koehn, C; Dionne, C E; Koehoorn, M; Harder, H; Pasca, R; Warje, O; Hsu, V; McGuire, L; Schulz, W; Kube, D; Hook, A; Wright, M D

    2015-04-01

    Physical and psychological job demands in combination with the degree of control a worker has over task completion, play an important role in reducing stress. Occupational stress is an important, modifiable factor affecting work disability. However, the effectiveness of reducing job demands or increasing job control remains unclear, particularly for outcomes of interest to employers, such as absenteeism or productivity. This systematic review reports on job demand and control interventions that impact absenteeism, productivity and financial outcomes. A stakeholder-centered best-evidence synthesis was conducted with researcher and stakeholder collaboration throughout. Databases and grey literature were searched for systematic reviews between 2000 and 2012: Medline, EMBASE, the Cochrane Database of Systematic Reviews, DARE, CINAHL, PsycINFO, TRIP, health-evidence.ca, Rehab+, National Rehabilitation Information Center (NARIC), and Institute for Work and Health. Articles were assessed independently by two researchers for inclusion criteria and methodological quality. Differences were resolved through consensus. The search resulted in 3363 unique titles. After review of abstracts, 115 articles were retained for full-text review. 11 articles finally met the inclusion criteria and are summarized in this synthesis. The best level of evidence we found indicates that multimodal job demand reductions for either at-work or off-work workers will reduce disability-related absenteeism. In general, the impacts of interventions that aim to reduce job demands or increase job control can be positive for the organization in terms of reducing absenteeism, increasing productivity and cost-effectiveness. However, more high quality research is needed to further assess the relationships and quantify effect sizes for the interventions and outcomes reviewed in this study.

  18. A novel complex air supply model for indoor air quality control via the occupant micro-environment demand ventilation

    International Nuclear Information System (INIS)

    Yang, Jie; Zhou, Bo; Jin, Maozhu; Wang, Jun; Xiong, Feng

    2016-01-01

    Protection of indoor air quality and human health can be achieved via ventilation, which has becomes one of the most important tasks for sustainable buildings. This approach also requires highly efficient and energy saving methods for modern building ventilations consisting of a set of parameters of the complex indoor system. Therefore, the advancement in understanding the characteristics of various ventilation methods is highly necessary. This study presents one novel air supply model for the complex occupant micro-environment demand control ventilations, to analyze the efficiency of various ventilation types. This model is established primarily according to the momentum and mass conservations, and goal of occupant micro-environment demand, which is a complex system with the characteristics of diversity and dynamic variation. As for different occupant densities, characteristics of outdoor air supply for controlling gaseous pollutant and three basic features of outdoor airflow supply reaching occupant micro-environment were obtained. This research shows that for various types of occupant density and storey height, the rising and descending rates of the demand outdoor airflow in mixing ventilation are higher than those under displacement ventilation conditions. In addition, since the structure is better designed and sewage flow is more efficient, the mixing ventilation also requires a much higher peak demand outdoor airflow than its counterpart. The increase of storey height will lead to a decline of pollutants in the breathing zone and the demand outdoor airflow. Fluctuations of air flow diffusion caused by the change of occupant density in architectural space, will lead to variations of outdoor airflow reaching occupant micro-environment. Accordingly, it would lead to the different peak values of demand outdoor airflow, and the difference becomes even significant if the occupant density increases. The variations of the air supply and fraction of air reaching the

  19. Beyond the job demand control (-support) model : explaining stress reactions in nurses

    NARCIS (Netherlands)

    Pisanti, Renato

    2012-01-01

    Nurses have been identified as having a risk of experiencing stress and burnout. The nature and organization of the job make nursing inherently difficult. Research highlights that occupational stress is largely dependent on psychosocial job characteristics, such as job demands and job resources. The

  20. Optimization-based feedforward control for a drop-on-demand inkjet printer

    NARCIS (Netherlands)

    Khalate, A.; Bombois, X.; Babuska, R.; Wijshoff, H.M.A.; Waarsing, R.

    2010-01-01

    The printing quality delivered by a Drop-on-Demand (DoD) inkjet printhead is limited due to operational issues such as residual oscillations in the ink channel and the cross-talk between the ink channels. The maximal jetting frequency of a DoD inkjet printhead can be increased by quickly damping the

  1. Stability and Change in the Exposure to Demands and Control: Results of the Longitudinal SMASH Study

    NARCIS (Netherlands)

    Lange, A. de; Taris, T.; Kompier, M.; Houtman, I.L.D.; Bongers, P.M.

    2001-01-01

    In 1979 Robert Karasek introduced the job demand-contol (DC model). Through its simplicity and applicability this model has gained “substantial face value” in the theory and practice of occupational health psychology and epidemiology. According to the DC model a psychosocial work environment can be

  2. Study of Demand as Frequency Controlled Reserve in Nordic Power System

    DEFF Research Database (Denmark)

    Zhao, Haoran; Wu, Qiuwei; Huang, Shaojun

    2016-01-01

    This paper investigates the efficacy of Demand Frequency Reserve (DFR) in Nordic power system. Heat pump, due to its switching flexibility, less disturbing impacts to customers and promising future in application, is used to represent DFR in the study. Thermodynamics of the heat pump unit...

  3. A Simulation of Rainwater Harvesting Design and Demand-Side Controls for Large Hospitals

    Directory of Open Access Journals (Sweden)

    Lawrence V. Fulton

    2018-05-01

    Full Text Available Inpatient health buildings in the United States are the most intensive users of water among large commercial buildings. Large facilities (greater than 1 million square feet consume an average of 90 million gallons per building per year. The distribution and treatment of water imposes a significant electrical power demand, which may be the single largest energy requirement for various states. Supply and demand-side solutions are needed, particularly in arid and semi-arid regions where water is scarce. This study uses continuous simulations based on 71 years of historical data to estimate how rainwater harvesting systems and demand-side interventions (e.g., low-flow devices, xeriscaping would offset the demand for externally-provided water sources in a semi-arid region. Simulations from time series models are used to generate alternative rainfall models to account for potential non-stationarity and volatility. Results demonstrate that hospital external water consumption might be reduced by approximately 25% using conservative assumptions and depending on the design of experiment parameters associated with rainfall capture area, building size, holding tank specifications, and conservation efforts.

  4. Challenges of using model predictive control for active demand side management

    DEFF Research Database (Denmark)

    Zong, Yi; You, Shi; Hu, Junjie

    2015-01-01

    When there is a high penetration of renewables in the power system, it requires coordinated management of large numbers of distributed and demand response resources, intermittent resources to maintain the grid reliability and improve operational economics. This paper presents a hierarchical...... and dynamic power price signals....

  5. The capacity investment decision for make-to-order production systems with demand rate control

    NARCIS (Netherlands)

    Bertrand, J.W.M.; Ooijen, van H.P.G.

    2012-01-01

    In this paper we study the capacity investment decision for make-to-order manufacturing firms that utilize a fixed capacity, operate in a stochastic, stationary market, and can influence their demand rate by increasing or decreasing their sales effort. We consider manufacturing situations that

  6. Managerial leadership is associated with employee stress, health, and sickness absence independently of the demand-control-support model.

    Science.gov (United States)

    Westerlund, Hugo; Nyberg, Anna; Bernin, Peggy; Hyde, Martin; Oxenstierna, Gabriel; Jäppinen, Paavo; Väänänen, Ari; Theorell, Töres

    2010-01-01

    Research on health effects of managerial leadership has only taken established work environment factors into account to a limited extent. We therefore investigated the associations between a measure of Attentive Managerial Leadership (AML), and perceived stress, age-relative self-rated health, and sickness absence due to overstrain/fatigue, adjusting for the dimensions of the Demand-Control-Support model. Blue- and white-collar workers from Finland, Germany and Sweden employed in a multi-national forest industry company (N=12,622). Cross-sectional data on leadership and health from a company-wide survey analysed with logistic regression in different subgroups. AML was associated with perceived stress, age-relative self-rated health, and sickness absence due to overstrain/fatigue after controlling for the Demand-Control-Support model. Lack of AML was significantly associated with a high stress level in all subgroups (OR=1.68-2.67). Associations with age-relative self-rated health and sickness absence due to overstrain/fatigue were weaker, but still significant, and in the expected direction for several of the subgroups studied, suggesting an association between lack of AML and negative health consequences. The study indicates that managerial leadership is associated with employee stress, health, and sickness absence independently of the Demand-Control-Support model and should be considered in future studies of health consequences for employees, and in work environment interventions.

  7. The importance of genetic and shared environmental factors for the associations between job demands, control, support and burnout.

    Directory of Open Access Journals (Sweden)

    Victoria Blom

    Full Text Available Within occupational health research, one of the most influential models is the Job Demands-Control-Support model. Numerous studies have applied the model to different domains, with both physical and psychological health outcomes, such as burnout. The twin design provides a unique and powerful research methodology for examining the effects of environmental risk factors on burnout while taking familial factors (genetic and shared environment into account. The aim of the present study was to investigate the impact of familial factors on the associations of burnout with job demands, control and support. A total of 14,516 individuals from the Swedish Twin Registry, who were born between 1959 and 1986, and who participated in the Study of Twin Adults: Genes and Environment (STAGE by responding to a web-based questionnaire in 2005, were included in the analyses. Of these, there were 5108 individuals in complete same-sex twin pairs. Co-twin control analyses were performed using linear mixed modeling, comparing between-pairs effects and within-pair effects, stratified also by zygosity and sex. The results indicate that familial factors are of importance in the association between support and burnout in both women and men, but not between job demands and burnout. There are also tendencies towards familial factors being involved in the association between control and burnout in men. These results offer increased understanding of the mechanisms involved in the associations between work stress and burnout.

  8. Job demand-control and job stress at work: A cross-sectional study among prison staff

    Science.gov (United States)

    Akbari, Jafar; Akbari, Rouhollah; Shakerian, Mahnaz; Mahaki, Behzad

    2017-01-01

    Introduction: Job stress can impose significant costs to the workplaces and organizations due to some issues such as absenteeism, less productivity, and medical costs. Job overload and lack of decision latitude can lead to job stress. The current study aimed to investigate the job demands and control as predictor of job stress and its relationship, with some of the demographic characteristics of Iranian prison staff. Materials and Methods: This study was performed on 171 male employees working in four prisons located in Ilam, Iran. The sampling method was census and all four prisons’ staff were selected to respond the Job Content Questionnaires. Finally, the data were analyzed using t-test or independent samples test as well as SPSS 20. Results: The highest amount of job demand (mean = 21.28) and the lowest amount of job control on average (9.76) were reported by those staff working in Darehshahr prison. There was also a significant relationship between job post and job control among the prison staff (β = −0.375, P = 0.001). Conclusion: The level of job stress reported by prison staff was high in this study mainly caused by high job demand and low job control, especially in Darehshahr prison staff. PMID:28546980

  9. Multitasking vs. multiplexing: Toward a normative account of limitations in the simultaneous execution of control-demanding behaviors

    OpenAIRE

    Feng, S. F.; Schwemmer, M.; Gershman, S. J.; Cohen, J. D.

    2014-01-01

    Why is it that behaviors that rely on control, so striking in their diversity and flexibility, are also subject to such striking limitations? Typically, people cannot engage in more than a few — and usually only a single — control-demanding task at a time. This limitation was a defining element in the earliest conceptualizations of controlled processing, it remains one of the most widely accepted axioms of cognitive psychology, and is even the basis for some laws (e.g., against the use of mob...

  10. The impact of price and tobacco control policies on the demand for electronic nicotine delivery systems.

    Science.gov (United States)

    Huang, Jidong; Tauras, John; Chaloupka, Frank J

    2014-07-01

    While much is known about the demand for conventional cigarettes, little is known about the determinants of demand for electronic nicotine delivery systems (ENDS or e-cigarettes). The goal of this study is to estimate the own and cross-price elasticity of demand for e-cigarettes and to examine the impact of cigarette prices and smoke-free policies on e-cigarette sales. Quarterly e-cigarette prices and sales and conventional cigarette prices from 2009 to 2012 were constructed from commercial retail store scanner data from 52 U.S. markets, for food, drug and mass stores, and from 25 markets, for convenience stores. Fixed-effects models were used to estimate the own and cross-price elasticity of demand for e-cigarettes and associations between e-cigarette sales and cigarette prices and smoke-free policies. Estimated own price elasticities for disposable e-cigarettes centred around -1.2, while those for reusable e-cigarettes were approximately -1.9. Disposable e-cigarette sales were higher in markets where reusable e-cigarette prices were higher and where less of the population was covered by a comprehensive smoke-free policy. There were no consistent and statistically significant relationships between cigarette prices and e-cigarette sales. E-cigarette sales are very responsive to own price changes. Disposable e-cigarettes appear to be substitutes for reusable e-cigarettes. Policies increasing e-cigarette retail prices, such as limiting rebates, discounts and coupons and imposing a tax on e-cigarettes, could potentially lead to significant reductions in e-cigarette sales. Differential tax policies based on product type could lead to substitution between different types of e-cigarettes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  11. The impact of price and tobacco control policies on the demand for electronic nicotine delivery systems

    Science.gov (United States)

    Huang, Jidong; Tauras, John; Chaloupka, Frank J

    2014-01-01

    Background While much is known about the demand for conventional cigarettes, little is known about the determinants of demand for electronic nicotine delivery systems (ENDS or e-cigarettes). The goal of this study is to estimate the own and cross-price elasticity of demand for e-cigarettes and to examine the impact of cigarette prices and smoke-free policies on e-cigarette sales. Methods Quarterly e-cigarette prices and sales and conventional cigarette prices from 2009 to 2012 were constructed from commercial retail store scanner data from 52 US markets, for food, drug and mass stores, and from 25 markets, for convenience stores. Fixed-effects models were used to estimate the own and cross-price elasticity of demand for e-cigarettes and associations between e-cigarette sales and cigarette prices and smoke-free policies. Results Estimated own price elasticities for disposable e-cigarettes centred around −1.2, while those for reusable e-cigarettes were approximately −1.9. Disposable e-cigarette sales were higher in markets where reusable e-cigarette prices were higher and where less of the population was covered by a comprehensive smoke-free policy. There were no consistent and statistically significant relationships between cigarette prices and e-cigarette sales. Conclusions E-cigarette sales are very responsive to own price changes. Disposable e-cigarettes appear to be substitutes for reusable e-cigarettes. Policies increasing e-cigarette retail prices, such as limiting rebates, discounts and coupons and imposing a tax on e-cigarettes, could potentially lead to significant reductions in e-cigarette sales. Differential tax policies based on product type could lead to substitution between different types of e-cigarettes. PMID:24935898

  12. Evaluating Job Demands and Control Measures for Use in Farm Worker Health Surveillance

    Science.gov (United States)

    Alterman, Toni; Gabbard, Susan; Grzywacz, Joseph G.; Shen, Rui; Li, Jia; Nakamoto, Jorge; Carroll, Daniel J.; Muntaner, Carles

    2015-01-01

    Workplace stress likely plays a role in health disparities; however, applying standard measures to studies of immigrants requires thoughtful consideration. The goal of this study was to determine the appropriateness of two measures of occupational stressors (‘decision latitude’ and ‘job demands’) for use with mostly immigrant Latino farm workers. Cross-sectional data from a pilot module containing a four-item measure of decision latitude and a two-item measure of job demands were obtained from a subsample (N = 409) of farm workers participating in the National Agricultural Workers Survey. Responses to items for both constructs were clustered toward the low end of the structured response-set. Percentages of responses of ‘very often’ and ‘always’ for each of the items were examined by educational attainment, birth country, dominant language spoken, task, and crop. Cronbach’s α, when stratified by subgroups of workers, for the decision latitude items were (0.65–0.90), but were less robust for the job demands items (0.25–0.72). The four-item decision latitude scale can be applied to occupational stress research with immigrant farm workers, and potentially other immigrant Latino worker groups. The short job demands scale requires further investigation and evaluation before suggesting widespread use. PMID:25138138

  13. Stochastic control and real options valuation of thermal storage-enabled demand response from flexible district energy systems

    OpenAIRE

    Kitapbayev, Yerkin; Moriarty, John; Mancarella, Pierluigi

    2014-01-01

    In district energy systems powered by Combined Heat and Power (CHP) plants, thermal storage can significantly increase CHP flexibility to respond to real time market signals and therefore improve the business case of such demand response schemes in a Smart Grid environment. However, main challenges remain as to what is the optimal way to control inter-temporal storage operation in the presence of uncertain market prices, and then how to value the investment into storage as flexibility enabler...

  14. Job control and demands, work-life balance and wellbeing among selfemployed men and women in Europe

    OpenAIRE

    Nordenmark, Mikael; Vinberg, Stig; Strandh, Mattias

    2012-01-01

    Self-employed persons and their enterprises are regarded as important to the economy for their contribution to economic development. However, an understanding of the relationship between the psychosocial working conditions, the work-life balance and outcomes, such as health and wellbeing among the self-employed and micro-enterprise is limited. The main aim of this article is to study the relationships between control and demands at work, the work-life balance and wellbeing among self-employed...

  15. Switched Control Strategies of Aggregated Commercial HVAC Systems for Demand Response in Smart Grids

    Directory of Open Access Journals (Sweden)

    Kai Ma

    2017-07-01

    Full Text Available This work proposes three switched control strategies for aggregated heating, ventilation, and air conditioning (HVAC systems in commercial buildings to track the automatic generation control (AGC signal in smart grid. The existing control strategies include the direct load control strategy and the setpoint regulation strategy. The direct load control strategy cannot track the AGC signal when the state of charge (SOC of the aggregated thermostatically controlled loads (TCLs exceeds their regulation capacity, while the setpoint regulation strategy provides flexible regulation capacity, but causes larger tracking errors. To improve the tracking performance, we took the advantages of the two control modes and developed three switched control strategies. The control strategies switch between the direct load control mode and the setpoint regulation mode according to different switching indices. Specifically, we design a discrete-time controller and optimize the controller parameter for the setpoint regulation strategy using the Fibonacci optimization algorithm, enabling us to propose two switched control strategies across multiple time steps. Furthermore, we extend the switched control strategies by introducing a two-stage regulation in a single time step. Simulation results demonstrate that the proposed switched control strategies can reduce the tracking errors for frequency regulation.

  16. Scheduling of Domestic Water Heater Power Demand for Maximizing PV Self-Consumption Using Model Predictive Control

    DEFF Research Database (Denmark)

    Sossan, Fabrizio; Kosek, Anna Magdalena; Martinenas, Sergejus

    2013-01-01

    This paper presents a model predictive control (MPC) strategy for maximizing photo-voltaic (PV) selfconsumption in a household context exploiting the flexible demand of an electric water heater. The predictive controller uses a water heater model and forecast of the hot Water consumption in order...... to predict the future temperature of the water and it manages its state (on and off) according to the forecasted PV production, which are computed starting from forecast of the solar irradiance. Simulations for the proof of concept and for validating the proposed control strategy are proposed. Results...... of the control approach are compared with a traditional thermostatic controller using historical measurements of a 10 kW PV installation. Economic results based on the Italian self consumption tariffs are also reported. The model of the water heater complex is a mixed grey and white box and its parameters have...

  17. Demand control on room level of the supply air temperature in an air heating and ventilation system

    DEFF Research Database (Denmark)

    Polak, Joanna; Afshari, Alireza; Bergsøe, Niels Christian

    2017-01-01

    air heating and ventilation system in a high performance single family house using BSim simulation software. The provision of the desired thermal conditions in different rooms was examined. Results show that the new control strategy can facilitate maintaining of desired temperatures in various rooms......The aim of this study was to investigate a new strategy for control of supply air temperature in an integrated air heating and ventilation system. The new strategy enables demand control of supply air temperature in individual rooms. The study is based on detailed dynamic simulations of a combined....... Moreover, this control strategy enables controlled temperature differentiation between rooms within the house and therefore provides flexibility and better balance in heat delivery. Consequently, the thermal conditions in the building can be improved....

  18. Model Predictive Controller for Active Demand Side Management with PV Self-consumption in an Intelligent Building

    DEFF Research Database (Denmark)

    Zong, Yi; Mihet-Popa, Lucian; Kullmann, Daniel

    2012-01-01

    This paper presents a Model Predictive Controller (MPC) for electrical heaters’ predictive power consumption including maximizing the use of local generation (e.g. solar power) in an intelligent building. The MPC is based on dynamic power price and weather forecast, considering users’ comfort...... settings to meet an optimization objective such as minimum cost and minimum reference temperature error. It demonstrates that this MPC strategy can realize load shifting, and maximize the PV self-consumption in the residential sector. With this demand side control study, it is expected that MPC strategy...

  19. Self-Determination as a Moderator of Demands and Control: Implications for Employee Strain and Engagement

    Science.gov (United States)

    Parker, Stacey L.; Jimmieson, Nerina L.; Amiot, Catherine E.

    2010-01-01

    Does job control act as a stress-buffer when employees' type and level of work self-determination is taken into account? It was anticipated that job control would only be stress-buffering for employees high in self-determined and low in non-self-determined work motivation. In contrast, job control would be stress-exacerbating for employees who…

  20. Social support and its interrelationships with demand-control model factors on presenteeism and absenteeism in Japanese civil servants.

    Science.gov (United States)

    Saijo, Yasuaki; Yoshioka, Eiji; Nakagi, Yoshihiko; Kawanishi, Yasuyuki; Hanley, Sharon J B; Yoshida, Takahiko

    2017-08-01

    To elucidate the impact of social support and its interrelations with other demand-control-support (DCS) model factors on presenteeism and absenteeism, and to determine which DCS factors were most influential. Questionnaires from 2535 local government employees were analyzed. The Brief Job Stress Questionnaire (BJSQ) was used to assess DCS factors including job demand, job control, and social support from supervisors and coworkers. The Stanford Presenteeism Scale 13-item version (SPS-13) was used to evaluate both absenteeism (absent days) and presenteeism. For the latter, the Work Impairment Score (WIS) and the Work Output Score (WOS) were also used. Possible confounder-adjusted logistic and negative binomial regression analyses were performed to obtain odds ratios (ORs) for WIS and WOS and relative risks (RRs) for absenteeism according to DCS factors. Higher job control had a significantly protective effect on higher WIS in both males and females and a lower WOS in males. Based on a point estimate of an OR per 1 standard deviation change of each DCS factor, job control had the strongest effect on higher WIS in both males and females and a lower WOS in males. Higher job demand resulted in significantly higher ORs for both male and female WIS, and a lower WOS in females. Support from supervisors had a significantly protective effect on higher WIS in females and a lower WOS in males. Support from coworkers had a significantly protective effect on higher WIS in males. Higher support from coworkers had a significantly protective effect on absenteeism among both males and females, and higher job control had a significantly protective effect in females. The combination of high job strain and low support from supervisors had a significantly worsening effect, except for absenteeism in females. High job strain and low support from coworkers had a significantly worsening effect except for WOS in males. The results suggest job control was the DCS factor most related to

  1. Control strategies and cycling demands for Li-ion storage batteries in residential micro-cogeneration systems

    International Nuclear Information System (INIS)

    Darcovich, K.; Kenney, B.; MacNeil, D.D.; Armstrong, M.M.

    2015-01-01

    Highlights: • Canadian home energy system modeled with PV, ICE CHP, battery and power grid. • Battery function is modeled on fundamental electrochemical principles. • Techno-economics of control strategies assessed. • Impact of control strategies battery cycles is developed for wear analysis. • Non-monotonic nature of battery cycles with transient renewables is discussed. - Abstract: Energy storage units have become important components in residential micro-cogeneration (MCG) systems. As MCG systems are often connected to single residences or buildings in a wide variety of settings, they are frequently unique and highly customized. Lithium-ion batteries have recently gained some profile as energy storage units of choice, because of their good capacity, high efficiency, robustness and ability to meet the demands of typical residential electrical loads. In the present work, modeled scenarios are explored which examine the performance of a MCG system with an internal combustion engine, photovoltaic input and a Li-ion storage battery. An electricity demand profile from new data collected in Ottawa, Canada is used to provide a full year energy use context for the analyses. The demands placed on the battery are examined to assess the suitability of the battery size and performance, as well as control related functionalities which reveal significantly varying battery use, and led to a quantitative expression for equivalent cycles. The energy use simulations are derived from electrochemical fundamentals adapted for a larger battery pack. Simulation output provides the basis for techno-economic commentary on how to assess large-scale Li-ion batteries for effective electrical storage purposes in MCG systems, and the impact of the nature of the control strategy on the battery service life

  2. Multitasking vs. multiplexing: Toward a normative account of limitations in the simultaneous execution of control-demanding behaviors

    Science.gov (United States)

    Feng, S. F.; Schwemmer, M.; Gershman, S. J.; Cohen, J. D.

    2014-01-01

    Why is it that behaviors that rely on control, so striking in their diversity and flexibility, are also subject to such striking limitations? Typically, people cannot engage in more than a few — and usually only a single — control-demanding task at a time. This limitation was a defining element in the earliest conceptualizations of controlled processing, it remains one of the most widely accepted axioms of cognitive psychology, and is even the basis for some laws (e.g., against the use of mobile devices while driving). Remarkably, however, the source of this limitation is still not understood. Here, we examine one potential source of this limitation, in terms of a tradeoff between the flexibility and efficiency of representation (“multiplexing”) and the simultaneous engagement of different processing pathways (“multitasking”). We show that even a modest amount of multiplexing rapidly introduces cross-talk among processing pathways, thereby constraining the number that can be productively engaged at once. We propose that, given the large number of advantages of efficient coding, the human brain has favored this over the capacity for multitasking of control-demanding processes. PMID:24481850

  3. Multitasking versus multiplexing: Toward a normative account of limitations in the simultaneous execution of control-demanding behaviors.

    Science.gov (United States)

    Feng, S F; Schwemmer, M; Gershman, S J; Cohen, J D

    2014-03-01

    Why is it that behaviors that rely on control, so striking in their diversity and flexibility, are also subject to such striking limitations? Typically, people cannot engage in more than a few-and usually only a single-control-demanding task at a time. This limitation was a defining element in the earliest conceptualizations of controlled processing; it remains one of the most widely accepted axioms of cognitive psychology, and is even the basis for some laws (e.g., against the use of mobile devices while driving). Remarkably, however, the source of this limitation is still not understood. Here, we examine one potential source of this limitation, in terms of a trade-off between the flexibility and efficiency of representation ("multiplexing") and the simultaneous engagement of different processing pathways ("multitasking"). We show that even a modest amount of multiplexing rapidly introduces cross-talk among processing pathways, thereby constraining the number that can be productively engaged at once. We propose that, given the large number of advantages of efficient coding, the human brain has favored this over the capacity for multitasking of control-demanding processes.

  4. Information and Communications Systems for Control-by-Price of Distributed Energy Resources and Flexible Demand

    DEFF Research Database (Denmark)

    Nyeng, Preben; Østergaard, Jacob

    2011-01-01

    infrastructure and subsystem design and secondly focus on the design and implementation of the end-user price-responsive controller, interfaces, and communications. The design and its applicability on existing devices is verified through laboratory tests with two cases: electric space heating thermostat control...... and a small combined heat and power unit. The results show that the price-responsive controller reduces the end user’s electricity cost, or increases his income respectively, by about 7%. At the same time, the price-responsive controller provides an interface for the transmission system operator to utilize...

  5. Fuzzy predictive filtering in nonlinear economic model predictive control for demand response

    DEFF Research Database (Denmark)

    Santos, Rui Mirra; Zong, Yi; Sousa, Joao M. C.

    2016-01-01

    problem. Moreover, to reduce the computation time and improve the controller's performance, a fuzzy predictive filter is introduced. With the purpose of testing the developed EMPC, a simulation controlling the temperature levels of an intelligent office building (PowerFlexHouse), with and without fuzzy...

  6. Age-Related Changes in Dynamic Postural Control and Attentional Demands are Minimally Affected by Local Muscle Fatigue

    Science.gov (United States)

    Remaud, Anthony; Thuong-Cong, Cécile; Bilodeau, Martin

    2016-01-01

    Normal aging results in alterations in the visual, vestibular and somtaosensory systems, which in turn modify the control of balance. Muscle fatigue may exacerbate these age-related changes in sensory and motor functions, and also increase the attentional demands associated with dynamic postural control. The purpose of this study was to investigate the effect of aging on dynamic postural control and posture-related attentional demands before and after a plantar flexor fatigue protocol. Participants (young adults: n = 15; healthy seniors: n = 13) performed a dynamic postural task along the antero-posterior (AP) and the medio-lateral (ML) axes, with and without the addition of a simple reaction time (RT) task. The dynamic postural task consisted in following a moving circle on a computer screen with the representation of the center of pressure (COP). This protocol was repeated before and after a fatigue task where ankle plantar flexor muscles were targeted. The mean COP-target distance and the mean COP velocity were calculated for each trial. Cross-correlation analyses between the COP and target displacements were also performed. RTs were recorded during dual-task trials. Results showed that while young adults adopted an anticipatory control mode to move their COP as close as possible to the target center, seniors adopted a reactive control mode, lagging behind the target center. This resulted in longer COP-target distance and higher COP velocity in the latter group. Concurrently, RT increased more in seniors when switching from static stance to dynamic postural conditions, suggesting potential alterations in the central nervous system (CNS) functions. Finally, plantar flexor muscle fatigue and dual-tasking had only minor effects on dynamic postural control of both young adults and seniors. Future studies should investigate why the fatigue-induced changes in quiet standing postural control do not seem to transfer to dynamic balance tasks. PMID:26834626

  7. The glycolytic flux in Escherichia coli is controlled by the demand for ATP

    DEFF Research Database (Denmark)

    Købmann, Brian Jensen; Westerhoff, H.V.; Snoep, J.L.

    2002-01-01

    additional ATP hydrolysis, we increased the flux through glycolysis to 1.7 times that of the wild-type flux. The results demonstrate why attempts in the past to increase the glycolytic flux through overexpression of glycolytic enzymes have been unsuccessful: the majority of flux control (> 75%) resides...... not inside but outside the pathway, i.e., with the enzymes that hydrolyze ATP. These data further allowed us to answer the question of whether catabolic or anabolic reactions control the growth of E. coli. We show that the majority of the control of growth rate resides in the anabolic reactions, i...

  8. Demand controlled ventilation in single-family homes; Behovstyret ventilation til enfamiliehuse

    Energy Technology Data Exchange (ETDEWEB)

    Rammer Nielsen, T.; Drivsholm, C.; Rudolph Hansen, M.P.; Kragh, J.

    2009-12-15

    This project investigated two different control strategies: A simple and cheap strategy and an advanced and expensive strategy: 1. Simple control: The ventilation rate is varied only on the whole building level giving an average ventilation rate of either 0.1 l/(s m{sup 2}) or 0.35 l/(s m{sup 2}). The air change rate is controlled by sensors in the air handling unit measuring relative humidity, temperature and CO{sub 2}. The control is based on the CO{sub 2}-concentration and absolute humidity in the supply air and exhaust air. A fixed set point for the difference in CO{sub 2}-concentration between the exhaust and supply is used to decide if the ventilation rate is low or high. As supplement to the CO{sub 2} control the difference in absolute humidity between exhaust and supply is used to assure that the ventilation remain at the high level if there is a high level of humidity in the house. 2. Advanced control: The air change rate is varied dynamically for all living rooms giving an average air change for the house between 0.1 l/(s m{sup 2}) and 0.35 l/(s m{sup 2}). The air change rate in the living rooms is controlled by CO{sub 2}-sensors in each room and dampers in the room supply duct. Relative humidity is measured in the rooms with high moisture production to ensure that the highest air exchange is activated if the relative humidity in one of these rooms is too high. Even though the two strategies have been implemented and tested for a long period of time, only the simple control can be recommended. The simple control ensures that the air quality is almost the same as if the house was ventilated constantly at the high ventilation rate. Also the simple control only requires two CO{sub 2} sensors, two relative humidity sensors and two temperature sensors in the air handling unit. These sensors should be checked from time to time e.g. when filters are exchanged. The simple control is today used in meeting rooms, office rooms and daycare facilities in a modified

  9. Job demands-control-social support model and coping strategies: predicting burnout and wellbeing in a group of Italian nurses.

    Science.gov (United States)

    Pisanti, R

    2012-01-01

    Nursing is generally considered to be a stressful profession. The purpose of the present study was to test the core hypotheses of the job demands-control-social support model (JDCS) of Karasek & Theorell (1990). In order to refine and extend the JDCS model, we also analyzed the direct and interactive role of three coping strategies: task- oriented, emotion-oriented, and avoidance-oriented coping. Questionnaire data from 1383 nurses (77%female) were collected. Controlling for demographic variables and non-linearity of the associations between job characteristics and outcomes (job satisfaction; burnout dimensions, psychological distress, and somatic complaints), hierarchical regression analyses indicated that job control and social support combined additively (p < 0.001) with job demands to explain the wellbeing outcomes (explained variance between 6% and 28%). Coping strategies accounted for additional variance (p < 0.001; explained variance between 4% and 15%) in all outcomes except in job satisfaction. Support was found for main effects of coping. Coping strategies did not moderate the impact of job characteristics on burnout and wellbeing. Emotion-oriented coping emerged as the most important predictor and was consistently associated with higher burnout levels and lower wellbeing levels. The results demonstrated the need to include the role of individual variables in the JDCS model. The limitations of the study, and theoretical and practical implications are discussed.

  10. Expected value based fuzzy programming approach to solve integrated supplier selection and inventory control problem with fuzzy demand

    Science.gov (United States)

    Sutrisno; Widowati; Sunarsih; Kartono

    2018-01-01

    In this paper, a mathematical model in quadratic programming with fuzzy parameter is proposed to determine the optimal strategy for integrated inventory control and supplier selection problem with fuzzy demand. To solve the corresponding optimization problem, we use the expected value based fuzzy programming. Numerical examples are performed to evaluate the model. From the results, the optimal amount of each product that have to be purchased from each supplier for each time period and the optimal amount of each product that have to be stored in the inventory for each time period were determined with minimum total cost and the inventory level was sufficiently closed to the reference level.

  11. Predictive Control Applied to a Solar Desalination Plant Connected to a Greenhouse with Daily Variation of Irrigation Water Demand

    Directory of Open Access Journals (Sweden)

    Lidia Roca

    2016-03-01

    Full Text Available The water deficit in the Mediterranean area is a known matter severely affecting agriculture. One way to avoid the aquifers’ exploitation is to supply water to crops by using thermal desalination processes. Moreover, in order to guarantee long-term sustainability, the required thermal energy for the desalination process can be provided by solar energy. This paper shows simulations for a case study in which a solar multi-effect distillation plant produces water for irrigation purposes. Detailed models of the involved systems are the base of a predictive controller to operate the desalination plant and fulfil the water demanded by the crops.

  12. Stochastic control and real options valuation of thermal storage-enabled demand response from flexible district energy systems

    International Nuclear Information System (INIS)

    Kitapbayev, Yerkin; Moriarty, John; Mancarella, Pierluigi

    2015-01-01

    Highlights: • We calculate the real option value of flexibility from CHP-thermal storage. • Stochastic optimal feedback control problem is solved under uncertain market prices. • Efficient real-time numerical solutions combine simulation, regression and recursion. • Clear, interpretable feedback control maps are produced for each hour of the day. • We give a realistic UK case study using projected market gas and electricity prices. - Abstract: In district energy systems powered by Combined Heat and Power (CHP) plants, thermal storage can significantly increase CHP flexibility to respond to real time market signals and therefore improve the business case of such demand response schemes in a Smart Grid environment. However, main challenges remain as to what is the optimal way to control inter-temporal storage operation in the presence of uncertain market prices, and then how to value the investment into storage as flexibility enabler. In this outlook, the aim of this paper is to propose a model for optimal and dynamic control and long term valuation of CHP-thermal storage in the presence of uncertain market prices. The proposed model is formulated as a stochastic control problem and numerically solved through Least Squares Monte Carlo regression analysis, with integrated investment and operational timescale analysis equivalent to real options valuation models encountered in finance. Outputs are represented by clear and interpretable feedback control strategy maps for each hour of the day, thus suitable for real time demand response under uncertainty. Numerical applications to a realistic UK case study with projected market gas and electricity prices exemplify the proposed approach and quantify the robustness of the selected storage solutions

  13. Cholgate - a randomized controlled trial comparing the effect of automated and on-demand decision support on the management of cardiovascular disease factors in primary care

    NARCIS (Netherlands)

    J.T. van Wyk (Jacobus); M.A.M. van Wijk (Marc); P.W. Moorman (Peter); M. Mosseveld (Mees); J. van der Lei (Johan)

    2003-01-01

    textabstractAutomated and on-demand decision support systems integrated into an electronic medical record have proven to be an effective implementation strategy for guidelines. Cholgate is a randomized controlled trial comparing the effect of automated and on-demand decision

  14. Two models at work : A study of interactions and specificity in relation to the Demand-Control Model and the Effort-Reward Imbalance Model

    NARCIS (Netherlands)

    Vegchel, N.

    2005-01-01

    To investigate the relation between work and employee health, several work stress models, e.g., the Demand-Control (DC) Model and the Effort-Reward Imbalance (ERI) Model, have been developed. Although these models focus on job demands and job resources, relatively little attention has been devoted

  15. Inventory control for a perishable product with non-stationary demand

    NARCIS (Netherlands)

    Pauls-Worm, K.G.J.

    2016-01-01

    Globally, around one-third of the edible parts of perishable food products is wasted every year. Adequate logistics management of the food supply chain is of importance. Inventory control of processed fresh food with a best-before or use-by date deals with the questions how much to order and how

  16. Hierarchical predictive control scheme for distributed energy storage integrated with residential demand and photovoltaic generation

    NARCIS (Netherlands)

    Lampropoulos, I.; Garoufalis, P.; van den Bosch, P.P.J.; Kling, W.L.

    2015-01-01

    A hierarchical control scheme is defined for the energy management of a battery energy storage system which is integrated in a low-voltage distribution grid with residential customers and photovoltaic installations. The scope is the economic optimisation of the integrated system by employing

  17. A Web Based Educational Programming Logic Controller Training Set Based on Vocational High School Students' Demands

    Directory of Open Access Journals (Sweden)

    Abdullah Alper Efe

    2018-01-01

    Full Text Available The purpose of this study was to design and develop aProgramming Logic Controller Training Set according to vocational high school students’ educational needs. In this regard, by using the properties of distance education the proposed system supported “hands-on” PLC programming laboratory exercises in industrial automation area. The system allowed students to access and control the PLC training set remotely. For this purpose, researcher designed a web site to facilitate students’ interactivity and support PLC programming. In the training set, Induction Motor, Frequency Converter and Encoder tripart controlled by Siemens Simatic S7-200 PLC controller by the help of SIMATIC Step 7 Programming Software were used to make the system more effective and efficient. Moreover, training set included an IP camera system allowing to monitor devices and pilot application. By working with this novel remote accessible training set, students and researchers recieved a chance to inhere self paced learning experiences. Also, The PLC training set offered an effective learning enviroenment for distance education, which is based on presenting the content on the web and opening it to the online users and provided a safe and economical solution for multiple users in a workplace to enhance the quality of education with less overall cost.

  18. Systems and methods for controlling energy use during a demand limiting period

    Science.gov (United States)

    Wenzel, Michael J.; Drees, Kirk H.

    2016-04-26

    Systems and methods for limiting power consumption by a heating, ventilation, and air conditioning (HVAC) subsystem of a building are shown and described. A feedback controller is used to generate a manipulated variable based on an energy use setpoint and a measured energy use. The manipulated variable may be used for adjusting the operation of an HVAC device.

  19. Cognitive demands and the relationship between age and workload in apron control.

    Science.gov (United States)

    Müller, Andreas; Petru, Raluca; Angerer, Peter

    2011-01-01

    Apron controllers (ACs) determine the taxiways for aircraft entering the apron area until they reach their parking positions and vice versa. The aims of this study were to identify age-sensitive job requirements of apron control (Study 1), and to investigate the relationship between age of ACs and their workload (Study 2). Study 1: There were 14 experienced ACs who assessed the job requirements of apron control with the Fleishman-Job Analyses Survey. Additionally, during one shift, the number of parallel processed traffic data sets (indicating memory-load) and the number of delivered radio messages (indicating processing speed requirements) were assessed. Study 2: There were 30 ACs (age: 23-51 yr) who volunteered for trials during late shifts at an international airport. ACs assessed their subjective workload (NASA-Task Load Index) at four times during the shift and carried out an attention test (d2) before and after the shift. Moreover, their heart rate was assessed during the shift and in a reference period. Study 1: Results indicate that apron control requires especially high levels of memory-load and processing speed. Study 2: Hierarchical regression analyses revealed a u-shaped relationship between age and subjective workload (beta = 0.59) as well as heart rate (beta = 0.33). Up to the age of about 35-37 yr, workload and heart rate decreased with age, but afterwards the relationship became positive. There was no association between chronological age and attention performance. There is a need for age adequate job design in apron control that should especially aim at the reduction of memory-load and processing speed.

  20. An inventory model of instantaneous deteriorating items with controllable deterioration rate for time dependent demand and holding cost

    Directory of Open Access Journals (Sweden)

    Vinod Kumar Mishra

    2013-06-01

    Full Text Available Purpose: The purpose of this paper to develop an inventory model for instantaneous deteriorating items with the consideration of the facts that the deterioration rate can be controlled by using the preservation technology (PT and the holding cost & demand rate both are linear function of time which was treated as constant in most of the deteriorating inventory model. Design/methodology/approach: Developed the mathematical equation of deterministic deteriorating inventory model in which demand rate and holding cost both is linear function of time, deterioration rate is constant, backlogging rate is variable and depend on the length of the next replenishment, shortages are allowed and partially backlogged and obtain an analytical solution which optimizes the total cost of the proposed inventory model. Findings: The model can be applied for optimizing the total inventory cost of deteriorating items inventory for such business enterprises where they use the preservation technology to control the deterioration rate under other assumptions of the model. Originality/value: The inventory system for deteriorating items has been an object of study for a long time, but little is known about the effect of investing in reducing the rate of product deterioration and their significant impact in the business. The proposed model is effective as well as efficient for the business organization that uses the preservation technology to reduce the deterioration rate of the instantaneous deteriorating items of the inventory.

  1. Externally controlled on-demand release of anti-HIV drug using magneto-electric nanoparticles as carriers.

    Science.gov (United States)

    Nair, Madhavan; Guduru, Rakesh; Liang, Ping; Hong, Jeongmin; Sagar, Vidya; Khizroev, Sakhrat

    2013-01-01

    Although highly active anti-retroviral therapy has resulted in remarkable decline in the morbidity and mortality in AIDS patients, inadequately low delivery of anti-retroviral drugs across the blood-brain barrier results in virus persistence. The capability of high-efficacy-targeted drug delivery and on-demand release remains a formidable task. Here we report an in vitro study to demonstrate the on-demand release of azidothymidine 5'-triphosphate, an anti-human immunodeficiency virus drug, from 30 nm CoFe2O4@BaTiO3 magneto-electric nanoparticles by applying a low alternating current magnetic field. Magneto-electric nanoparticles as field-controlled drug carriers offer a unique capability of field-triggered release after crossing the blood-brain barrier. Owing to the intrinsic magnetoelectricity, these nanoparticles can couple external magnetic fields with the electric forces in drug-carrier bonds to enable remotely controlled delivery without exploiting heat. Functional and structural integrity of the drug after the release was confirmed in in vitro experiments with human immunodeficiency virus-infected cells and through atomic force microscopy, spectrophotometry, Fourier transform infrared and mass spectrometry studies.

  2. Effect of nitrous oxide on cisatracurium infusion demands: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Illman Hanna L

    2010-08-01

    Full Text Available Abstract Background Recent studies have questioned our previous understanding on the effect of nitrous oxide on muscle relaxants, since nitrous oxide has been shown to potentiate the action of bolus doses of mivacurium, rocuronium and vecuronium. This study was aimed to investigate the possible effect of nitrous oxide on the infusion requirements of cisatracurium. Methods 70 ASA physical status I-III patients aged 18-75 years were enrolled in this randomized trial. The patients were undergoing elective surgery requiring general anesthesia with a duration of at least 90 minutes. Patients were randomized to receive propofol and remifentanil by target controlled infusion in combination with either a mixture of oxygen and nitrous oxide (Nitrous oxide/TIVA group or oxygen in air (Air/TIVA group. A 0.1 mg/kg initial bolus of cisatracurium was administered before tracheal intubation, followed by a closed-loop computer controlled infusion of cisatracurium to produce and maintain a 90% neuromuscular block. Cumulative dose requirements of cisatracurium during the 90-min study period after bolus administration were measured and the asymptotic steady state rate of infusion to produce a constant 90% block was determined by applying nonlinear curve fitting to the data on the cumulative dose requirement during the study period. Results Controller performance, i.e. the ability of the controller to maintain neuromuscular block constant at the setpoint and patient characteristics were similar in both groups. The administration of nitrous oxide did not affect cisatracurium infusion requirements. The mean steady-state rates of infusion were 0.072 +/- 0.018 and 0.066 +/- 0.017 mg * kg-1 * h-1 in Air/TIVA and Nitrous oxide/TIVA groups, respectively. Conclusions Nitrous oxide does not affect the infusion requirements of cisatracurium. Trial registration ClinicalTrials.gov NCT01152905; European Clinical Trials Database at http://eudract.emea.eu.int/2006-006037-41.

  3. Pupillary Response as an Indicator of Processing Demands Within a Supervisory Control Simulation Environment

    Science.gov (United States)

    2015-05-07

    Yerkes, R.M., and Dodson, J.D. (1908). The relation of strength of stimulus to rapidity of habit -formation. Journal of comparative neurology and psychology 18, 459-482. ...the amount of mental effort exerted (Kahneman, 1973; Beatty & Lucero-Wagoner, 2000; Andreassi, 2007). The vast majority of these studies , however...of this initial study , the authors were interested in investigating whether pupillometry data collected in a realistic UAV supervisory control

  4. Estresse ocupacional e saúde: contribuições do Modelo Demanda-Controle Occupational stress and health: contributions of the Demand-Control Model

    Directory of Open Access Journals (Sweden)

    Tânia Maria de Araújo

    2003-01-01

    Full Text Available Nos últimos anos registra-se marcado esforço de construção de modelos teórico-metodológicos para avaliar características do trabalho e efeitos à saúde dos trabalhadores. Dentre os modelos propostos, o Modelo Demanda-Controle tem alcançado destaque. Esse modelo recorta duas dimensões no ambiente laboral: as demandas psicológicas e o controle do trabalhador sobre o próprio trabalho. O Job Content Questionnaire (JCQ é o instrumento proposto para medir essas dimensões do trabalho. Este estudo objetiva apresentar as bases teóricas e metodológicas do modelo demanda-controle, e discutir sua capacidade para identificar diferentes situações de trabalho no contexto brasileiro, a partir do uso do JCQ. Achados preliminares de dois estudos epidemiológicos, de corte transversal, são apresentados e discutidos. Os estudos avaliaram aspectos psicossociais do trabalho, utilizando o JCQ, e a saúde mental dos trabalhadores, usando o SRQ-20. Os resultados apontaram boa capacidade do modelo demanda-controle para identificar diferentes situações de risco à saúde mental dos trabalhadores. Aspectos relacionados à demanda psicológica do trabalho estavam mais fortemente associados a elevadas prevalências de distúrbios psíquicos menores do que os aspectos referentes ao controle.In the last years, strong efforts have been made to construct theoretical and methodological models that evaluate work characteristics and health effects in occupational groups. Among the proposed models, the Demand-Control Model has had a worldwide use. This model identifies two job dimensions in the work situation: psychological job demand and job control. The Job Content Questionnaire (JCQ has been proposed as an instrument for measuring these work dimensions. This study aim to present the theoretical and methodological bases of the Demand-Control Model and to discuss this model capability to identify different work situations in the Brazilian context, using the JCQ

  5. Exact Fill Rates for the (R, S Inventory Control with Discrete Distributed Demands for the Backordering Case

    Directory of Open Access Journals (Sweden)

    Eugenia BABILONI

    2012-01-01

    Full Text Available The fill rate is usually computed by using the traditional approach, which calculates it as the complement of the quotient between the expected unfulfilled demand and the expected demand per replenishment cycle, instead of directly the expected fraction of fulfilled demand. Furthermore the available methods to estimate the fill rate apply only under specific demand conditions. This paper shows the research gap regarding the estimation procedures to compute the fill rate and suggests: (i a new exact procedure to compute the traditional approximation for any discrete demand distribution; and (ii a new method to compute the fill rate directly as the fraction of fulfilled demand for any discrete demand distribution. Simulation results show that the latter methods outperform the traditional approach, which underestimates the simulated fill rate, over different demand patterns. This paper focuses on the traditional periodic review, base stock system when backlogged demands are allowed.

  6. Demand Uncertainty

    DEFF Research Database (Denmark)

    Nguyen, Daniel Xuyen

    This paper presents a model of trade that explains why firms wait to export and why many exporters fail. Firms face uncertain demands that are only realized after the firm enters the destination. The model retools the timing of uncertainty resolution found in productivity heterogeneity models....... This retooling addresses several shortcomings. First, the imperfect correlation of demands reconciles the sales variation observed in and across destinations. Second, since demands for the firm's output are correlated across destinations, a firm can use previously realized demands to forecast unknown demands...... in untested destinations. The option to forecast demands causes firms to delay exporting in order to gather more information about foreign demand. Third, since uncertainty is resolved after entry, many firms enter a destination and then exit after learning that they cannot profit. This prediction reconciles...

  7. Experimental Determination of Demand Response Control Models and Cost of Control for Ensembles of Window-Mount Air Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Geller, Drew Adam [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Backhaus, Scott N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-29

    Control of consumer electrical devices for providing electrical grid services is expanding in both the scope and the diversity of loads that are engaged in control, but there are few experimentally-based models of these devices suitable for control designs and for assessing the cost of control. A laboratory-scale test system is developed to experimentally evaluate the use of a simple window-mount air conditioner for electrical grid regulation services. The experimental test bed is a single, isolated air conditioner embedded in a test system that both emulates the thermodynamics of an air conditioned room and also isolates the air conditioner from the real-world external environmental and human variables that perturb the careful measurements required to capture a model that fully characterizes both the control response functions and the cost of control. The control response functions and cost of control are measured using harmonic perturbation of the temperature set point and a test protocol that further isolates the air conditioner from low frequency environmental variability.

  8. Induced abortion on demand and birth rate in Sami-speaking municipalities and a control group in Finnmark, Norway

    Directory of Open Access Journals (Sweden)

    Jan Norum

    2013-05-01

    Full Text Available Objectives. The objective of this study was to analyze the birth and induced abortion on demand (IAD rate among women in Sami-speaking communities and a control group in Finnmark County, Norway. Methods. The 6 northern municipalities included in the administration area of the Sami language law (study group were matched with a control group of 9 municipalities. Population data (numbers, sex and age were accessed from Statistics Norway. Data on birth rate and IAD during the time period 1999–2009 were derived from the Medical Birth Registry (MBR of Norway. Data on number of women in fertile age (15–44 years were obtained from Statistics Norway. Between 2001 and 2008, this age group was reduced by 12% (Sami and 23% (controls, respectively. Results. Finnmark County has a high IAD rate and 1 in 4 pregnancies (spontaneous abortions excluded ended in IAD in the study and control groups. The total fertility rate per woman was 1.94 and 1.87 births, respectively. There was no difference between groups with regard to the IAD/birth ratio (P=0.94 or general fertility rate GFR (P=0.82. Conclusions. Women in the Sami-majority area and a control group in Finnmark County experienced a similar frequency of IAD and fertility rate.

  9. System Design for Demand Controlled Ventilation in Multi-Family Dwellings

    DEFF Research Database (Denmark)

    Mortensen, Dorthe Kragsig; Nielsen, Toke Rammer

    2011-01-01

    This paper presents an investigation into solutions for the system design of a centralized DCV system in multi-family dwellings. The design focused on simple and inexpensive solutions. A cost benefit estimate showed that the initial cost of implementing DCV in a system with an efficient heat...... exchanger should not exceed 3400 DKK per dwelling in regions with weather conditions similar to the Danish climate. A design expected to fulfil this requirement was investigated in detail with regard to its electricity consumption by evaluation of different control strategies. Systems with variable airflows...... load reduces throttling and energy can be saved. A static pressure reset strategy was applied to a dwelling-specific DCV system where the airflow varied between three fixed rates. The system performance was evaluated for two diffusers. The annual electricity consumption was reduced by 20% to 30% when...

  10. Alloy chemistry and microstructural control to meet the demands of the automotive Stirling engine

    Science.gov (United States)

    Stephens, J. R.

    1986-01-01

    The automotive Stirling engine now under development by DOE/NASA as an alternative to the internal combustion engine, imposes severe materials requirements for the hot portion of the engine. Materials selected must be low cost and contain a minimum of strategic elements so that availability is not a problem. Heater head tubes contain high pressure hydrogen on the inside and are exposed to hot combustion gases on the outside surface. The cylinders and regenerator housings must be readily castable into complex shapes having varying wall thicknesses and be amenable to brazing and welding operations. Also, high strength, oxidation resistance, resistance to hydrogen permeation, cyclic operation, and long-life are required. A research program conducted by NASA Lewis focused on alloy chemistry and microstructural control to achieve the desired properties over the life of the engine. Results of alloy selection, characterization, evaluation, and actual engine testing of selected materials are presented.

  11. STTR Phase I: Low-Cost, High-Accuracy, Whole-Building Carbon Dioxide Monitoring for Demand Control Ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Hallstrom, Jason; Ni, Zheng Richard

    2018-05-15

    This STTR Phase I project assessed the feasibility of a new CO2 sensing system optimized for low-cost, high-accuracy, whole-building monitoring for use in demand control ventilation. The focus was on the development of a wireless networking platform and associated firmware to provide signal conditioning and conversion, fault- and disruptiontolerant networking, and multi-hop routing at building scales to avoid wiring costs. Early exploration of a bridge (or “gateway”) to direct digital control services was also explored. Results of the project contributed to an improved understanding of a new electrochemical sensor for monitoring indoor CO2 concentrations, as well as the electronics and networking infrastructure required to deploy those sensors at building scales. New knowledge was acquired concerning the sensor’s accuracy, environmental response, and failure modes, and the acquisition electronics required to achieve accuracy over a wide range of CO2 concentrations. The project demonstrated that the new sensor offers repeatable correspondence with commercial optical sensors, with supporting electronics that offer gain accuracy within 0.5%, and acquisition accuracy within 1.5% across three orders of magnitude variation in generated current. Considering production, installation, and maintenance costs, the technology presents a foundation for achieving whole-building CO2 sensing at a price point below $0.066 / sq-ft – meeting economic feasibility criteria established by the Department of Energy. The technology developed under this award addresses obstacles on the critical path to enabling whole-building CO2 sensing and demand control ventilation in commercial retrofits, small commercial buildings, residential complexes, and other highpotential structures that have been slow to adopt these technologies. It presents an opportunity to significantly reduce energy use throughout the United States a

  12. An Efficient Demand Side Management System with a New Optimized Home Energy Management Controller in Smart Grid

    Directory of Open Access Journals (Sweden)

    Hafiz Majid Hussain

    2018-01-01

    Full Text Available The traditional power grid is inadequate to overcome modern day challenges. As the modern era demands the traditional power grid to be more reliable, resilient, and cost-effective, the concept of smart grid evolves and various methods have been developed to overcome these demands which make the smart grid superior over the traditional power grid. One of the essential components of the smart grid, home energy management system (HEMS enhances the energy efficiency of electricity infrastructure in a residential area. In this aspect, we propose an efficient home energy management controller (EHEMC based on genetic harmony search algorithm (GHSA to reduce electricity expense, peak to average ratio (PAR, and maximize user comfort. We consider EHEMC for a single home and multiple homes with real-time electricity pricing (RTEP and critical peak pricing (CPP tariffs. In particular, for multiple homes, we classify modes of operation for the appliances according to their energy consumption with varying operation time slots. The constrained optimization problem is solved using heuristic algorithms: wind-driven optimization (WDO, harmony search algorithm (HSA, genetic algorithm (GA, and proposed algorithm GHSA. The proposed algorithm GHSA shows higher search efficiency and dynamic capability to attain optimal solutions as compared to existing algorithms. Simulation results also show that the proposed algorithm GHSA outperforms the existing algorithms in terms of reduction in electricity cost, PAR, and maximize user comfort.

  13. The nature of mind wandering during reading varies with the cognitive control demands of the reading strategy.

    Science.gov (United States)

    Moss, Jarrod; Schunn, Christian D; Schneider, Walter; McNamara, Danielle S

    2013-11-20

    Prior studies of mind wandering find the default network active during mind wandering, but these studies have yielded mixed results concerning the role of cognitive control brain regions during mind wandering. Mind wandering often interferes with reading comprehension, and prior neuroimaging studies of discourse comprehension and strategic reading comprehension have shown that there are at least two networks of brain regions that support strategic discourse comprehension: a domain-general control network and a network of regions supporting coherence-building comprehension processes. The present study was designed to further examine the neural correlates of mind wandering by examining mind wandering during strategic reading comprehension. Participants provided ratings of mind wandering frequency that were used to investigate interactions between the strategy being performed and brain regions whose activation was modulated by wind wandering. The results support prior findings showing that cognitive control regions are at times more active during mind wandering than during a task with low control demands, such as rereading. This result provides an initial examination of the neural correlates of mind wandering during discourse comprehension and shows that the processes being engaged by the primary task need to be considered when studying mind wandering. The results also replicate, in a different learning domain, prior findings of key brain areas associated with different reading strategies. © 2013 Published by Elsevier B.V.

  14. Exact Fill Rates for the (R, S) Inventory Control with Discrete Distributed Demands for the Backordering Case

    OpenAIRE

    Eugenia BABILONI; Ester GUIJARRO; Manuel CARDÓS; Sofía ESTELLÉS

    2012-01-01

    The fill rate is usually computed by using the traditional approach, which calculates it as the complement of the quotient between the expected unfulfilled demand and the expected demand per replenishment cycle, instead of directly the expected fraction of fulfilled demand. Furthermore the available methods to estimate the fill rate apply only under specific demand conditions. This paper shows the research gap regarding the estimation procedures to compute the fill rate and suggests: (i) a ne...

  15. Experimental analysis of flexibility change with different levels of power reduction by demand response activation on thermostat controlled loads

    DEFF Research Database (Denmark)

    Lakshmanan, Venkatachalam; Marinelli, Mattia; Hu, Junjie

    2017-01-01

    This paper studies the flexibility available with thermostatically controlled loads (TCLs) to provide power system services by demand response (DR) activation. Although the DR activation on TCLs can provide power system ancillary services, it is important to know how long such services can...... be provided for when different levels of power reduction are imposed. The flexibility change with different levels of power reduction is tested experimentally with domestic fridges used by real customers with unknown user interaction. The investigation quantifies the flexibility of household fridges...... and the impact of DR activation in terms of deviation in the average temperature. The maximum possible power reduction with the cluster of refrigerators is 67% and the available flexibility with the cluster of refrigerators is 10%. The resulting deviation in the average temperature is 14%....

  16. The demand-control model for job strain: a commentary on different ways to operationalize the exposure variable

    Directory of Open Access Journals (Sweden)

    Márcia Guimarães de Mello Alves

    2015-01-01

    Full Text Available Demand-control has been the most widely used model to study job strain in various countries. However, researchers have used the model differently, thus hindering the comparison of results. Such heterogeneity appears in both the study instrument used and in the definition of the main exposure variable - high strain. This cross-sectional study aimed to assess differences between various ways of operationalizing job strain through association with prevalent hypertension in a cohort of workers (Pro-Health Study. No difference in the association between high job strain and hypertension was found according to the different ways of operationalizing exposure, even though prevalence varied widely, according to the adopted form, from 19.6% for quadrants to 42% for subtraction tertile. The authors recommend further studies to define the cutoff for exposure variables using combined subjective and objective data.

  17. Optimal Ordering Policy and Coordination Mechanism of a Supply Chain with Controllable Lead-Time-Dependent Demand Forecast

    Directory of Open Access Journals (Sweden)

    Hua-Ming Song

    2011-01-01

    Full Text Available This paper investigates the ordering decisions and coordination mechanism for a distributed short-life-cycle supply chain. The objective is to maximize the whole supply chain's expected profit and meanwhile make the supply chain participants achieve a Pareto improvement. We treat lead time as a controllable variable, thus the demand forecast is dependent on lead time: the shorter lead time, the better forecast. Moreover, optimal decision-making models for lead time and order quantity are formulated and compared in the decentralized and centralized cases. Besides, a three-parameter contract is proposed to coordinate the supply chain and alleviate the double margin in the decentralized scenario. In addition, based on the analysis of the models, we develop an algorithmic procedure to find the optimal ordering decisions. Finally, a numerical example is also presented to illustrate the results.

  18. Application of particle swarm optimisation for solving deteriorating inventory model with fluctuating demand and controllable deterioration rate

    Science.gov (United States)

    Chen, Yu-Ren; Dye, Chung-Yuan

    2013-06-01

    In most of the inventory models in the literature, the deterioration rate of goods is viewed as an exogenous variable, which is not subject to control. In the real market, the retailer can reduce the deterioration rate of product by making effective capital investment in storehouse equipments. In this study, we formulate a deteriorating inventory model with time-varying demand by allowing preservation technology cost as a decision variable in conjunction with replacement policy. The objective is to find the optimal replenishment and preservation technology investment strategies while minimising the total cost over the planning horizon. For any given feasible replenishment scheme, we first prove that the optimal preservation technology investment strategy not only exists but is also unique. Then, a particle swarm optimisation is coded and used to solve the nonlinear programming problem by employing the properties derived from this article. Some numerical examples are used to illustrate the features of the proposed model.

  19. Is the mineralisation response to root exudation controlled by the microbial stoichiometric demand in subarctic soils?

    Science.gov (United States)

    Rousk, Johannes; Hicks, Lettice; Leizeaga, Ainara; Michelsen, Anders; Rousk, Kathrin

    2017-04-01

    Climate change will expose arctic and subarctic systems to warming and a shift towards plant communities with more rhizosphere labile C input. Labile C can also increase the rate of loss of native soil organic matter (SOM); a phenomenon termed 'priming'. We investigated how warming (+1.1˚ C over ambient using open top chambers) and the addition of plant litter (90 g m-2 y-1) or organic nitrogen (N) (fungal fruit bodies; 90 g m-2 y-1) in the Subarctic influenced the susceptibility of SOM mineralisation to priming, and its microbial underpinnings. Root exudation were simulated with the addition of labile organic matter both in the form of only labile C (13C-glucose) or in the form of labile C and N (13C-alanine). We hypothesized that labile C would induce a higher mineralization of N than C sourced from SOM ("N mining"); a response unrelated to microbial growth responses. We also hypothesized that the N mining effect would be more pronounced in climate change simulation treatments of higher C/N (plant litter) than treatments with lower C/N (fungal fruitbodies and warming), with the control treatments intermediate. We also hypothesized that the addition of labile C and N would not result in selective N mining, but instead coupled responses of C and N mineralisation sourced from SOM; a response that would coincide with stimulated microbial growth responses. Labile C appeared to inhibit the mineralisation of C from SOM by up to 60% within hours. In contrast, the mineralisation of N from SOM was stimulated by up to 300%. These responses occurred rapidly and were unrelated to microbial successional dynamics, suggesting catabolic responses. Considered separately, the labile-C inhibited C mineralisation is compatible with previously reported findings termed 'preferential substrate utilisation' or 'negative apparent priming', while the stimulated N mineralisation responses echo recent reports of 'real priming' of SOM mineralisation. However, C and N mineralisation responses

  20. Review of Literature on Terminal Box Control, Occupancy Sensing Technology and Multi-zone Demand Control Ventilation (DCV)

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guopeng; Dasu, Aravind R.; Zhang, Jian

    2012-03-01

    This report presents an overall review of the standard requirement, the terminal box control, occupancy sensing technology and DCV. There is system-specific guidance for single-zone systems, but DCV application guidance for multi-zone variable air volume (VAV) systems is not available. No real-world implementation case studies have been found using the CO2-based DCV. The review results also show that the constant minimum air flow set point causes excessive fan power consumption and potential simultaneous heating and cooling. Occupancy-based control (OBC) is needed for the terminal box in order to achieve deep energy savings. Key to OBC is a technology for sensing the actual occupancy of the zone served in real time. Several technologies show promise, but none currently fully meets the need with adequate accuracy and sufficiently low cost.

  1. Ongoing activity in temporally coherent networks predicts intra-subject fluctuation of response time to sporadic executive control demands.

    Science.gov (United States)

    Nozawa, Takayuki; Sugiura, Motoaki; Yokoyama, Ryoichi; Ihara, Mizuki; Kotozaki, Yuka; Miyauchi, Carlos Makoto; Kanno, Akitake; Kawashima, Ryuta

    2014-01-01

    Can ongoing fMRI BOLD signals predict fluctuations in swiftness of a person's response to sporadic cognitive demands? This is an important issue because it clarifies whether intrinsic brain dynamics, for which spatio-temporal patterns are expressed as temporally coherent networks (TCNs), have effects not only on sensory or motor processes, but also on cognitive processes. Predictivity has been affirmed, although to a limited extent. Expecting a predictive effect on executive performance for a wider range of TCNs constituting the cingulo-opercular, fronto-parietal, and default mode networks, we conducted an fMRI study using a version of the color-word Stroop task that was specifically designed to put a higher load on executive control, with the aim of making its fluctuations more detectable. We explored the relationships between the fluctuations in ongoing pre-trial activity in TCNs and the task response time (RT). The results revealed the existence of TCNs in which fluctuations in activity several seconds before the onset of the trial predicted RT fluctuations for the subsequent trial. These TCNs were distributed in the cingulo-opercular and fronto-parietal networks, as well as in perceptual and motor networks. Our results suggest that intrinsic brain dynamics in these networks constitute "cognitive readiness," which plays an active role especially in situations where information for anticipatory attention control is unavailable. Fluctuations in these networks lead to fluctuations in executive control performance.

  2. Smart microgrid hierarchical frequency control ancillary service provision based on virtual inertia concept: An integrated demand response and droop controlled distributed generation framework

    International Nuclear Information System (INIS)

    Rezaei, Navid; Kalantar, Mohsen

    2015-01-01

    Highlights: • Detailed formulation of the microgrid static and dynamic securities based on droop control and virtual inertia concepts. • Constructing a novel objective function using frequency excursion and rate of change of frequency profiles. • Ensuring the microgrid security subject to the microgrid economic and environmental policies. • Coordinated management of demand response and droop controlled distributed generation resources. • Precise scheduling of day-ahead hierarchical frequency control ancillary services using a scenario based stochastic programming. - Abstract: Low inertia stack, high penetration levels of renewable energy source and great ratio of power deviations in a small power delivery system put microgrid frequency at risk of instability. On the basis of the close coupling between the microgrid frequency and system security requirements, procurement of adequate ancillary services from cost-effective and environmental friendly resources is a great challenge requests an efficient energy management system. Motivated by this need, this paper presents a novel energy management system that is aimed to coordinately manage the demand response and distributed generation resources. The proposed approach is carried out by constructing a hierarchical frequency control structure in which the frequency dependent control functions of the microgrid components are modeled comprehensively. On the basis of the derived modeling, both the static and dynamic frequency securities of an islanded microgrid are provided in primary and secondary control levels. Besides, to cope with the low inertia stack of islanded microgrids, novel virtual inertia concept is devised based on the precise modeling of droop controlled distributed generation resources. The proposed approach is applied to typical test microgrid. Energy and hierarchical reserve resource are scheduled precisely using a scenario-based stochastic programming methodology. Moreover, analyzing the

  3. Speed and path control for conflict-free flight in high air traffic demand in terminal airspace

    Science.gov (United States)

    Rezaei, Ali

    To accommodate the growing air traffic demand, flights will need to be planned and navigated with a much higher level of precision than today's aircraft flight path. The Next Generation Air Transportation System (NextGen) stands to benefit significantly in safety and efficiency from such movement of aircraft along precisely defined paths. Air Traffic Operations (ATO) relying on such precision--the Precision Air Traffic Operations or PATO--are the foundation of high throughput capacity envisioned for the future airports. In PATO, the preferred method is to manage the air traffic by assigning a speed profile to each aircraft in a given fleet in a given airspace (in practice known as (speed control). In this research, an algorithm has been developed, set in the context of a Hybrid Control System (HCS) model, that determines whether a speed control solution exists for a given fleet of aircraft in a given airspace and if so, computes this solution as a collective speed profile that assures separation if executed without deviation. Uncertainties such as weather are not considered but the algorithm can be modified to include uncertainties. The algorithm first computes all feasible sequences (i.e., all sequences that allow the given fleet of aircraft to reach destinations without violating the FAA's separation requirement) by looking at all pairs of aircraft. Then, the most likely sequence is determined and the speed control solution is constructed by a backward trajectory generation, starting with the aircraft last out and proceeds to the first out. This computation can be done for different sequences in parallel which helps to reduce the computation time. If such a solution does not exist, then the algorithm calculates a minimal path modification (known as path control) that will allow separation-compliance speed control. We will also prove that the algorithm will modify the path without creating a new separation violation. The new path will be generated by adding new

  4. User-Preference-Driven Model Predictive Control of Residential Building Loads and Battery Storage for Demand Response: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Xin [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Baker, Kyri A. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Christensen, Dane T. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Isley, Steven C. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-21

    This paper presents a user-preference-driven home energy management system (HEMS) for demand response (DR) with residential building loads and battery storage. The HEMS is based on a multi-objective model predictive control algorithm, where the objectives include energy cost, thermal comfort, and carbon emission. A multi-criterion decision making method originating from social science is used to quickly determine user preferences based on a brief survey and derive the weights of different objectives used in the optimization process. Besides the residential appliances used in the traditional DR programs, a home battery system is integrated into the HEMS to improve the flexibility and reliability of the DR resources. Simulation studies have been performed on field data from a residential building stock data set. Appliance models and usage patterns were learned from the data to predict the DR resource availability. Results indicate the HEMS was able to provide a significant amount of load reduction with less than 20% prediction error in both heating and cooling cases.

  5. A comparative study of long-term energy demand and potential greenhouse gas emission control in Bangladesh

    International Nuclear Information System (INIS)

    Khalaquazzaman, Mohammad

    2005-02-01

    This report presents a comparative study of long-term energy demand and potential greenhouse gas emissions projections from energy demand and supply sectors in Bangladesh covering the period 2000 to 2020. The study was conducted employing the IAEA's tool ENPEP- BALANCE model. This study presents a reliable energy system plan with minimal carbon emission for the country. Primary energy demands distributed by energy carriers and electricity demand have been projected based on macro-economic growth scenarios constructed for national energy policy of 1996. The conservation of indigenous energy resources was emphasized to build a long-term secured energy supply system. The potential energy supply options including nuclear energy and prospective greenhouse gas mitigation options were analyzed

  6. Job-Demands, Job Control, Social Support, Self-Efficacy, and Burnout of Staff of Residential Children's Homes

    Science.gov (United States)

    Brouwers, André; Tomic, Welko

    2016-01-01

    The aim of the current study was to examine among educational staff members of residential children's homes to what extent task demands, job control, emotional and social support from colleagues and management as well as self-efficacy beliefs concerning coping with aggressive behaviour in youngsters are associated with emotional exhaustion,…

  7. The associations of humorous coping styles, affective states, job demands and job control with the frequency of upper respiratory tract infection

    NARCIS (Netherlands)

    Doosje, S.; De Goede, M.P.M.; Van Doornen, L.J.P.; Van de Schoot, R.

    2011-01-01

    Orientation: There is some evidence that job demands and job resources such as job control and humorous coping may contribute to the risk of upper respiratory tract infections (URTI). Research purpose: The purpose of this study was to test a model including these variables as well as job-related

  8. A multilevel analysis of the demands-control model: Is stress at work determined by factors at the group level or the individual level?

    NARCIS (Netherlands)

    Van Yperen, N.W.; Snijders, T.A.B.

    2000-01-01

    This study explored the extent to which negative health-related outcomes are associated with differences between work groups and with differences between individuals within work groups using R. A. Karasek's (1979) demands-control model. The sample consisted of 260 employees in 31 working groups of a

  9. Application of Karasek's demand/control model a Canadian occupational setting including shift workers during a period of reorganization and downsizing.

    Science.gov (United States)

    Schechter, J; Green, L W; Olsen, L; Kruse, K; Cargo, M

    1997-01-01

    To apply Karasek's Job Content Model to an analysis of the relationships between job type and perceived stress and stress behaviors in a large company during a period of reorganization and downsizing. Cross-sectional mail-out, mail-back survey. A large Canadian telephone/telecommunications company. Stratified random sample (stratified by job category) of 2200 out of 13,000 employees with a response rate of 48.8%. Responses to 25 of Karasek's core questions were utilized to define four job types: low-demand and high control = "relaxed"; high demand and high control = "active"; low demand and low control = "passive", and high demand and low control = "high strain." These job types were compared against self-reported stress levels, perceived general level of health, absenteeism, alcohol use, exercise level, and use of medications and drugs. Similar analyses were performed to assess the influence of shift work. Employees with "passive" or "high strain" job types reported higher levels of stress (trend test p Karasek and Theorell was validated in this setting with respect to stress and some stress-associated attitudes and behaviors.

  10. Incorporation of Emotional Labor in the Demand-Control-Support Model: The relation with Emotional Exhaustion and Personal Accomplishment in Nurses

    NARCIS (Netherlands)

    Näring, Gérard; van Droffelaar, Annemarie

    2008-01-01

    Nursing comprises interactions with patients which may require emotional labor. This study clarifies the relation of emotional labor with the three burnout dimensions within the context of the Demand Control Support model in nurses. We used the Dutch Questionnaire on Emotional Labor (D-QEL) to

  11. CO2 sensor versus Volatile Organic Compounds (VOC) sensor – analysis of field measurement data and implications for demand controlled ventilation

    DEFF Research Database (Denmark)

    Kolarik, Jakub

    2014-01-01

    The study investigated performance of two commercially available non-selective metal oxide semiconductor VOC sensors and two commercially available non dispersive infrared CO2 sensors installed in one person office. The office was equipped with demand controlled ventilation. The signals from VOC...

  12. Predicting changes in sleep complaints from baseline values and changes in work demands, work control, and work preoccupation - The WOLF-project

    NARCIS (Netherlands)

    Äkerstedt, T.; Nordin, M.; Alfredsson, L.; Westerholm, P.; Kecklund, L.G.

    2012-01-01

    Study objective: Stress as a cause of disturbed sleep is often taken for granted, but the longitudinal evidence is limited. The aim of this study was to evaluate new cases of poor sleep as a function of changes in reported work demands, work control, and work preoccupation. Methods: Longitudinal

  13. Computation of order and volume fill rates for a base stock inventory control system with heterogeneous demand to investigate which customer class gets the best service

    DEFF Research Database (Denmark)

    Larsen, Christian

    We consider a base stock inventory control system serving two customer classes whose demands are generated by two independent compound renewal processes. We show how to derive order and volume fill rates of each class. Based on assumptions about first order stochastic dominance we prove when one...

  14. Dynamic modeling, experimental evaluation, optimal design and control of integrated fuel cell system and hybrid energy systems for building demands

    Science.gov (United States)

    Nguyen, Gia Luong Huu

    obtained experimental data, the research studied the control of airflow to regulate the temperature of reactors within the fuel processor. The dynamic model provided a platform to test the dynamic response for different control gains. With sufficient sensing and appropriate control, a rapid response to maintain the temperature of the reactor despite an increase in power was possible. The third part of the research studied the use of a fuel cell in conjunction with photovoltaic panels, and energy storage to provide electricity for buildings. This research developed an optimization framework to determine the size of each device in the hybrid energy system to satisfy the electrical demands of buildings and yield the lowest cost. The advantage of having the fuel cell with photovoltaic and energy storage was the ability to operate the fuel cell at baseload at night, thus reducing the need for large battery systems to shift the solar power produced in the day to the night. In addition, the dispatchability of the fuel cell provided an extra degree of freedom necessary for unforeseen disturbances. An operation framework based on model predictive control showed that the method is suitable for optimizing the dispatch of the hybrid energy system.

  15. Which daily experiences can foster well-being at work? A diary study on the interplay between flow experiences, affective commitment, and self-control demands.

    Science.gov (United States)

    Rivkin, Wladislaw; Diestel, Stefan; Schmidt, Klaus-Helmut

    2018-01-01

    Previous research has provided strong evidence for affective commitment as a direct predictor of employees' psychological well-being and as a resource that buffers the adverse effects of self-control demands as a stressor. However, the mechanisms that underlie the beneficial effects of affective commitment have not been examined yet. Drawing on the self-determination theory, we propose day-specific flow experiences as the mechanism that underlies the beneficial effects of affective commitment, because flow experiences as peaks of intrinsic motivation constitute manifestations of autonomous regulation. In a diary study covering 10 working days with N = 90 employees, we examine day-specific flow experiences as a mediator of the beneficial effects of interindividual affective commitment and a buffering moderator of the adverse day-specific effects of self-control demands on indicators of well-being (ego depletion, need for recovery, work engagement, and subjective vitality). Our results provide strong support for our predictions that day-specific flow experiences a) mediate the beneficial effects of affective commitment on employees' day-specific well-being and b) moderate (buffer) the adverse day-specific effects of self-control demands on well-being. That is, on days with high levels of flow experiences, employees were better able to cope with self-control demands whereas self-control demands translated into impaired well-being when employees experienced lower levels of day-specific flow experiences. We then discuss our findings and suggest practical implications. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  16. Differential effects of decision latitude and control on the job demands-strain relationship: a cross-sectional survey study among elderly care nursing staff.

    Science.gov (United States)

    Schmidt, Klaus-Helmut; Diestel, Stefan

    2011-03-01

    According to the influential Job Demands-Control (JD-C) model developed by Karasek (1979; Karasek and Theorell, 1990), job strain is expected to result from high job demands and low job control as well as an interaction between both job characteristics. Previous research, however, has found such an interaction only rarely or inconsistently.It has been suggested that the conceptualization of the control variable (formerly referred to as decision latitude) may be particularly responsible for the lack of supportive findings. The present study aimed at clarifying this issue by contrasting a focused measure of control with a traditional measure of decision latitude in their relations to job strain of health care workers. The measure of decision latitude encompassed a wide range of job characteristics including control, task variety, and learning opportunities. A cross-sectional questionnaire survey was conducted with job satisfaction, psychosomatic complaints and emotional exhaustion as criterion measures of job strain. A supra-regional organization for residential elderly care with 11 nursing homes located in a federal state in Germany. Questionnaires were distributed to the whole nursing staff, of which 379 filled in the questionnaire during normal working hours (68% participation rate). In addition to confirmatory factor analyses, descriptive statistics, and bivariate correlations, hierarchical multiple regression analyses were performed for testing the corresponding interaction effects. Findings confirmed the assumption that the focused measure of control and the traditional measure of decision latitude represent distinct, yet correlated factors. Furthermore, findings revealed a significant interaction effect between job demands and control on all outcomes considered. By way of contrast, there was no equivalent interaction effect between job demands and decision latitude. In line with the JD-C model, the adverse influence of increasing demands on job satisfaction

  17. Factorial invariance, scale reliability, and construct validity of the job control and job demands scales for immigrant workers: The Multi-Ethnic Study of Atherosclerosis (MESA)

    Science.gov (United States)

    Fujishiro, Kaori; Landsbergis, Paul; Roux, Ana V. Diez; Stukovsky, Karen Hinckley; Shrager, Sandi; Baron, Sherry

    2014-01-01

    Immigrants have a different social context from those who stay in their home country or those who were born to the country that immigrants now live. Cultural theory of risk perception suggests that social context influences one’s interpretation of questionnaire items. We examined psychometric properties of job control and job demand scales with US- and foreign-born workers who preferred English, Spanish, or Chinese (n=3114, mean age=58.1). Across all groups, the job control scale had acceptable Cronbach’s alpha (0.78–0.83) and equivalent factor loadings (ΔCFIjob demands scale regardless of language, education, or age of migration. Two job-demand items had different factor loadings across groups. Among immigrants, both scales had inconsistent associations with perceived job stress and self-rated health. For a better understanding of immigrants’ job stress, the concept of job demands should be expanded and immigrants’ expectations for job control explored. (149/150 limit) PMID:20582720

  18. Performance improvement of a drop-on-demand inkjet printhead using an optimization-based feedforward control method

    NARCIS (Netherlands)

    Khalate, A.; Bombois, X.; Babuska, R.; Wijshoff, H.M.A.; Waarsing, R.

    2011-01-01

    The printing quality delivered by a drop-on-demand (DoD) inkjet printhead is limited due to the residual oscillations in the ink channel. The maximal jetting frequency of a DoD inkjet printhead can be increased by quickly damping the residual oscillations and by bringing in this way the ink channel

  19. Quantifying demand flexibility of power-to-heat and thermal energy storage in the control of building heating systems

    NARCIS (Netherlands)

    Finck, C.J.; Li, R.; Kramer, R.P.; Zeiler, W.

    2018-01-01

    In the future due to continued integration of renewable energy sources, demand-side flexibility would be required for managing power grids. Building energy systems will serve as one possible source of energy flexibility. The degree of flexibility provided by building energy systems is highly

  20. Derivation of confidence intervals of service measures in a base-stock inventory control system with low-frequent demand

    DEFF Research Database (Denmark)

    Larsen, Christian

    We explore a base-stock system with backlogging where the demand process is a compound renewal process and the compound element is a delayed geometric distribution. For this setting it is proven in [4] that the long-run average service measures order fill rate (OFR) and volume fill rate (VFR) are...

  1. Derivation of confidence intervals of service measures in a base-stock inventory control system with low-frequent demand

    DEFF Research Database (Denmark)

    Larsen, Christian

    2011-01-01

    We explore a base-stock system with backlogging where the demand process is a compound renewal process and the compound element is a delayed geometric distribution. For this setting it holds that the long-run average service measures order fill rate (OFR) and volume fill rate (VFR) are equal in v...

  2. In demand

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, B. [Bridgestone Ltd. (United Kingdom)

    2005-11-01

    The paper explains how good relationships can help alleviate potential tyre shortages. Demand for large dump truck tyres (largely for China) has increased by 50% within 12 months. Bridgestone's manufacturing plants are operating at maximum capacity. The company supplies tyres to all vehicles at Scottish Coal's opencast coal mines. Its Tyre Management System (TMS) supplied free of charge to customers helps maximise tyre life and minimise downtime from data on pressure, tread and general conditions fed into the hand-held TMS computer. 3 photos.

  3. The Influence of Recognition and Social Support on European Health Professionals' Occupational Stress: A Demands-Control-Social Support-Recognition Bayesian Network Model.

    Science.gov (United States)

    García-Herrero, Susana; Lopez-Garcia, Jose R; Herrera, Sixto; Fontaneda, Ignacio; Báscones, Sonia Muñoz; Mariscal, Miguel A

    2017-01-01

    Healthcare professionals undergo high levels of occupational stress as a result of their working conditions. Thus, the aim of this study is to develop a model that focuses on healthcare professionals so as to analyze the influence that job demands, control, social support, and recognition have on the likelihood that a worker will experience stress. The data collected correspond to 2,211 healthcare workers from 35 countries, as reported in the sixth European Working Condition Survey (EWCS). The results obtained from this study allow us to infer stress under several working condition scenarios and to identify the more relevant variables in order to reduce this stress in healthcare professionals, which is of paramount importance to managing the stress of workers in this sector. The Bayesian network proposed indicates that emotional demands have a greater influence on raising the likelihood of stress due to workload than do family demands. The results show that the support of colleagues, in general, has less effect on reducing stress than social support from superiors. Furthermore, the sensitivity analysis shows that, in high-demand and low-control situations, recognition clearly impacts stress, drastically reducing it.

  4. Applications and Energy Consumption of Demand Controlled Ventilation Systems. Modelling, Simulation and Implementation of Modular Built Dynamical VAV Systems and Control Strategies

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, Bjoern R.

    2002-07-01

    This thesis discusses many topics of heating and ventilation. This is because the ventilation system is an integrated part of its host building. The functionality and effectiveness of the ventilation system are very much dependent on the building's architectural design, its internal materials, its occupants, its air tightness characteristics and its placement in the terrain. Although this thesis emphasizes strongly on VAV (Variable Air Volume) systems and, in particular, modelling and simulation of such systems, it touches a range of important HVAC related issues. The scope is however, limited to the field of comfort ventilation. That is because ventilation in industrial environments often is subject to separate regulations, and requires other and specialized methods of design and evaluation of ventilation performance. The main objectives have been to: (1) Develop mathematical models for VAV components and systems. (2) Evaluate existing and develop new strategies for VAV demand controlled ventilation by system simulation. (3) Investigate the potential for saving energy and the impact on indoor climate. The development of mathematical models and simulation of VAV systems are given quite much attention compared to the other topics discussed.

  5. From rationing to energy saving certificates. Four decades of power demand control in France and United Kingdom

    International Nuclear Information System (INIS)

    Pautard, Eric

    2012-01-01

    From 'saving energy' awareness campaign to financial incentives for efficient technologies, from rationing to energy efficiency commitment, from monopolistic public management to compelling involvement of the electricity-supply market, from economic stakes to ecological issues, Demand-Side Management policies have changed over time. This paper analyzes this historical background in order to examine the effects of the electricity market deregulation in France and United Kingdom

  6. Exploring the Impact of Network Structure and Demand Collaboration on the Dynamics of a Supply Chain Network Using a Robust Control Approach

    Directory of Open Access Journals (Sweden)

    Yongchang Wei

    2015-01-01

    uncertain environment. The impact of network structure and collaboration on the dynamics and robustness of supply chain network, however, remains to be explored. In this paper, a unified state space model for a two-layer supply chain network composed of multiple distributors and multiple retailers is developed. A robust control algorithm is advocated to reduce both order and demand fluctuations for unknown demand. Numerical simulations demonstrate that the robust control approach has the advantage to reduce both inventory and order fluctuations. In the simulation experiment, it is interesting to notice that complex network structure and collaborations might contribute to the reduction of inventory and order oscillations. This paper yields new insights into the overestimated bullwhip effect problem and helps us understand the complexities of supply chain networks.

  7. The associations of humorous coping styles, affective states, job demands and job control with the frequency of upper respiratory tract infection

    Directory of Open Access Journals (Sweden)

    Sibe Doosje

    2011-05-01

    Research purpose: The purpose of this study was to test a model including these variables as well as job-related affect, in order to explore their role in the explanation of the frequency of upper respiratory tract infection. Motivation of the study: This study has been conducted in order to extend our understanding of the role of traditional variables like job demands and job control with humorous coping styles and affective variables with regard to the explanation of the frequency of URTI. Research design, approach and method: A sample of 2094 employees filled out questionnaires assessing job demands, job control, generic (MSHS-C, antecedent-focused and responsefocused humorous coping (QOHC and job-related affect (JAWS. Main findings: Job demands were indirectly related to the frequency of upper respiratory tract infections, mediated by their relationships with job control and negative job-related affect. Generic and response-focused humorous coping were less relevant for the explanation of the frequency of upper respiratory tract infections than the presumably ‘healthy’ antecedentfocused humorous coping style. The latter showed a negative association with negative jobrelated affect. The frequency of upper respiratory tract infections was better predicted by job control and negative job-related affect than by humorous coping, in the expected directions. Practical/managerial implication: These findings may have practical relevance for the improvement of stress management interventions in organisations. Contribution/value-add: Although it was shown that healthy humorous coping does contribute to decreases in upper respiratory tract infection, job demands, job resources and negative affective state seem the most important predictors.

  8. PERIODIC REVIEW SYSTEM FOR INVENTORY REPLENISHMENT CONTROL FOR A TWO-ECHELON LOGISTICS NETWORK UNDER DEMAND UNCERTAINTY: A TWO-STAGE STOCHASTIC PROGRAMING APPROACH

    OpenAIRE

    Cunha, P.S.A.; Oliveira, F.; Raupp, Fernanda M.P.

    2017-01-01

    ABSTRACT Here, we propose a novel methodology for replenishment and control systems for inventories of two-echelon logistics networks using a two-stage stochastic programming, considering periodic review and uncertain demands. In addition, to achieve better customer services, we introduce a variable rationing rule to address quantities of the item in short. The devised models are reformulated into their deterministic equivalent, resulting in nonlinear mixed-integer programming models, which a...

  9. Computation of order and volume fill rates for a base stock inventory control system with heterogeneous demand to investigate which customer class gets the best service

    OpenAIRE

    Larsen, Christian

    2006-01-01

    We consider a base stock inventory control system serving two customer classes whose demands are generated by two independent compound renewal processes. We show how to derive order and volume fill rates of each class. Based on assumptions about first order stochastic dominance we prove when one customer class will get the best service. That theoretical result is validated through a series of numerical experiments which also reveal that it is quite robust.

  10. A comparison between the order and the volume fill rates for a base-stock inventory control system under a compound renewal demand process

    OpenAIRE

    Larsen, Christian; Thorstenson, Anders

    2006-01-01

    The order fill rate is less commonly used than the volume fill rate (most often just denoted fill rate) as a performance measure for inventory control systems. However, in settings where the focus is on filling customer orders rather than total quantities, the order fill rate should be the preferred measure. In this paper we consider a continuous review, base-stock policy, where all replenishment orders have the same constant lead time and all unfilled demands are backordered. We develop exac...

  11. An infrastructure with a unified control plane to integrate IP into optical metro networks to provide flexible and intelligent bandwidth on demand for cloud computing

    Science.gov (United States)

    Yang, Wei; Hall, Trevor

    2012-12-01

    The Internet is entering an era of cloud computing to provide more cost effective, eco-friendly and reliable services to consumer and business users and the nature of the Internet traffic will undertake a fundamental transformation. Consequently, the current Internet will no longer suffice for serving cloud traffic in metro areas. This work proposes an infrastructure with a unified control plane that integrates simple packet aggregation technology with optical express through the interoperation between IP routers and electrical traffic controllers in optical metro networks. The proposed infrastructure provides flexible, intelligent, and eco-friendly bandwidth on demand for cloud computing in metro areas.

  12. PERIODIC REVIEW SYSTEM FOR INVENTORY REPLENISHMENT CONTROL FOR A TWO-ECHELON LOGISTICS NETWORK UNDER DEMAND UNCERTAINTY: A TWO-STAGE STOCHASTIC PROGRAMING APPROACH

    Directory of Open Access Journals (Sweden)

    P.S.A. Cunha

    Full Text Available ABSTRACT Here, we propose a novel methodology for replenishment and control systems for inventories of two-echelon logistics networks using a two-stage stochastic programming, considering periodic review and uncertain demands. In addition, to achieve better customer services, we introduce a variable rationing rule to address quantities of the item in short. The devised models are reformulated into their deterministic equivalent, resulting in nonlinear mixed-integer programming models, which are then approximately linearized. To deal with the uncertain nature of the item demand levels, we apply a Monte Carlo simulation-based method to generate finite and discrete sets of scenarios. Moreover, the proposed approach does not require restricted assumptions to the behavior of the probabilistic phenomena, as does several existing methods in the literature. Numerical experiments with the proposed approach for randomly generated instances of the problem show results with errors around 1%.

  13. Predicting changes in sleep complaints from baseline values and changes in work demands, work control, and work preoccupation--the WOLF-project.

    Science.gov (United States)

    Åkerstedt, Torbjörn; Nordin, Maria; Alfredsson, Lars; Westerholm, Peter; Kecklund, Göran

    2012-01-01

    Stress as a cause of disturbed sleep is often taken for granted, but the longitudinal evidence is limited. The aim of this study was to evaluate new cases of poor sleep as a function of changes in reported work demands, work control, and work preoccupation. Longitudinal study of change with measures occurring twice within a 5-year interval during a period when the prevalence of impaired sleep was increasing in Sweden. The sample of companies was taken from northern Sweden (Norrland) and included 3637 individuals from the "WOLF Norrland" longitudinal cohort, collected through company health services. During the measurement period, 16% of those studied developed new cases of impaired sleep. Logistic regressions adjusted for demographics, work environment factors, and disturbed sleep at T1 period one showed a significant increase in new cases for high work demands and high work preoccupation (OR=1.37; Ci=1.09-1.72 and OR=1.80; CI=1.42-2.28, respectively). The analysis of change in the predictors showed effects of a change from low to high work demands (OR=1.39; Ci=1.00-1.95) on new cases of impaired sleep. Consistent high work demands (high at both points) showed a similar increase (OR=1.49; Ci=1.06-2.11) but no effect was seen for reduced demands. Change in work preoccupation yielded stronger effects with OR=2.47 (1.78-2.47) for increased work preoccupation and OR=3.79 (2.70-5.31) for consistent high work preoccupation. Also, a reduction in work preoccupation was associated with a reduction in new cases of disturbed sleep. Control at work was not related to sleep. Stratification with respect to gender mainly led to fewer significant results (particularly for women) due to larger confidence intervals. It was concluded that self-reported work preoccupation predicts subsequent impairment of sleep and that increased preoccupation is associated with new cases of impaired sleep. Similar, but weaker, results were obtained for work demands. Copyright © 2011 Elsevier B

  14. An integrated supply chain inventory model with imperfect-quality items, controllable lead time and distribution-free demand

    Directory of Open Access Journals (Sweden)

    Lin Hsien-Jen

    2013-01-01

    Full Text Available In this paper, we consider an integrated vendor-buyer inventory policy for a continuous review model with a random number of defective items and screening process gradually at a fixed screening rate in buyer’s arriving order lot. We assume that shortages are allowed and partially backlogged on the buyer’s side, and that the lead time demand distribution is unknown, except its first two moments. The objective is to apply the minmax distribution free approach to determine the optimal order quantity, reorder point, lead time and the number of lots delivered in one production run simultaneously so that the expected total system cost is minimized. Numerical experiments along with sensitivity analysis were performed to illustrate the effects of parameters on the decision and the total system cost.

  15. Validity test of the IPD-Work consortium approach for creating comparable job strain groups between Job Content Questionnaire and Demand-Control Questionnaire

    Directory of Open Access Journals (Sweden)

    Bongkyoo Choi

    2015-04-01

    Full Text Available Objectives: This study aims to test the validity of the IPD-Work Consortium approach for creating comparable job strain groups between the Job Content Questionnaire (JCQ and the Demand-Control Questionnaire (DCQ. Material and Methods: A random population sample (N = 682 of all middle-aged Malmö males and females was given a questionnaire with the 14-item JCQ and 11-item DCQ for the job control and job demands. The JCQ job control and job demands scores were calculated in 3 different ways: using the 14-item JCQ standard scale formulas (method 1; dropping 3 job control items and using the 11-item JCQ standard scale formulas with additional scale weights (method 2; and the approach of the IPD Group (method 3, dropping 3 job control items, but using the simple 11-item summation-based scale formulas. The high job strain was defined as a combination of high demands and low control. Results: Between the 2 questionnaires, false negatives for the high job strain were much greater than false positives (37–49% vs. 7–13%. When the method 3 was applied, the sensitivity of the JCQ for the high job strain against the DCQ was lowest (0.51 vs. 0.60–0.63 when the methods 1 and 2 were applied, although the specificity was highest (0.93 vs. 0.87–0.89 when the methods 1 and 2 were applied. The prevalence of the high job strain with the JCQ (the method 3 was applied was considerably lower (4–7% than with the JCQ (the methods 1 and 2 were applied and the DCQ. The number of congruent cases for the high job strain between the 2 questionnaires was smallest when the method 3 was applied. Conclusions: The IPD-Work Consortium approach showed 2 major weaknesses to be used for epidemiological studies on the high job strain and health outcomes as compared to the standard JCQ methods: the greater misclassification of the high job strain and lower prevalence of the high job strain.

  16. Validity test of the IPD-Work consortium approach for creating comparable job strain groups between Job Content Questionnaire and Demand-Control Questionnaire.

    Science.gov (United States)

    Choi, Bongkyoo; Ko, Sangbaek; Ostergren, Per-Olof

    2015-01-01

    This study aims to test the validity of the IPD-Work Consortium approach for creating comparable job strain groups between the Job Content Questionnaire (JCQ) and the Demand-Control Questionnaire (DCQ). A random population sample (N = 682) of all middle-aged Malmö males and females was given a questionnaire with the 14-item JCQ and 11-item DCQ for the job control and job demands. The JCQ job control and job demands scores were calculated in 3 different ways: using the 14-item JCQ standard scale formulas (method 1); dropping 3 job control items and using the 11-item JCQ standard scale formulas with additional scale weights (method 2); and the approach of the IPD Group (method 3), dropping 3 job control items, but using the simple 11-item summation-based scale formulas. The high job strain was defined as a combination of high demands and low control. Between the 2 questionnaires, false negatives for the high job strain were much greater than false positives (37-49% vs. 7-13%). When the method 3 was applied, the sensitivity of the JCQ for the high job strain against the DCQ was lowest (0.51 vs. 0.60-0.63 when the methods 1 and 2 were applied), although the specificity was highest (0.93 vs. 0.87-0.89 when the methods 1 and 2 were applied). The prevalence of the high job strain with the JCQ (the method 3 was applied) was considerably lower (4-7%) than with the JCQ (the methods 1 and 2 were applied) and the DCQ. The number of congruent cases for the high job strain between the 2 questionnaires was smallest when the method 3 was applied. The IPD-Work Consortium approach showed 2 major weaknesses to be used for epidemiological studies on the high job strain and health outcomes as compared to the standard JCQ methods: the greater misclassification of the high job strain and lower prevalence of the high job strain. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  17. Real-time adjustment of pressure to demand in water distribution systems: Parameter-less P-controller algorithm

    CSIR Research Space (South Africa)

    Page, Philip R

    2016-08-01

    Full Text Available Remote real-time control is currently the most advanced form of pressure management. Here the parameters describing pressure control valves (or pumps) are changed in real-time in such a way to provide the most optimal pressure in the water...

  18. Factor structure and longitudinal measurement invariance of the demand control support model: an evidence from the Swedish Longitudinal Occupational Survey of Health (SLOSH).

    Science.gov (United States)

    Chungkham, Holendro Singh; Ingre, Michael; Karasek, Robert; Westerlund, Hugo; Theorell, Töres

    2013-01-01

    To examine the factor structure and to evaluate the longitudinal measurement invariance of the demand-control-support questionnaire (DCSQ), using the Swedish Longitudinal Occupational Survey of Health (SLOSH). A confirmatory factor analysis (CFA) and multi-group confirmatory factor analysis (MGCFA) models within the framework of structural equation modeling (SEM) have been used to examine the factor structure and invariance across time. Four factors: psychological demand, skill discretion, decision authority and social support, were confirmed by CFA at baseline, with the best fit obtained by removing the item repetitive work of skill discretion. A measurement error correlation (0.42) between work fast and work intensively for psychological demands was also detected. Acceptable composite reliability measures were obtained except for skill discretion (0.68). The invariance of the same factor structure was established, but caution in comparing mean levels of factors over time is warranted as lack of intercept invariance was evident. However, partial intercept invariance was established for work intensively. Our findings indicate that skill discretion and decision authority represent two distinct constructs in the retained model. However removing the item repetitive work along with either work fast or work intensively would improve model fit. Care should also be taken while making comparisons in the constructs across time. Further research should investigate invariance across occupations or socio-economic classes.

  19. Factor structure and longitudinal measurement invariance of the demand control support model: an evidence from the Swedish Longitudinal Occupational Survey of Health (SLOSH.

    Directory of Open Access Journals (Sweden)

    Holendro Singh Chungkham

    Full Text Available OBJECTIVES: To examine the factor structure and to evaluate the longitudinal measurement invariance of the demand-control-support questionnaire (DCSQ, using the Swedish Longitudinal Occupational Survey of Health (SLOSH. METHODS: A confirmatory factor analysis (CFA and multi-group confirmatory factor analysis (MGCFA models within the framework of structural equation modeling (SEM have been used to examine the factor structure and invariance across time. RESULTS: Four factors: psychological demand, skill discretion, decision authority and social support, were confirmed by CFA at baseline, with the best fit obtained by removing the item repetitive work of skill discretion. A measurement error correlation (0.42 between work fast and work intensively for psychological demands was also detected. Acceptable composite reliability measures were obtained except for skill discretion (0.68. The invariance of the same factor structure was established, but caution in comparing mean levels of factors over time is warranted as lack of intercept invariance was evident. However, partial intercept invariance was established for work intensively. CONCLUSION: Our findings indicate that skill discretion and decision authority represent two distinct constructs in the retained model. However removing the item repetitive work along with either work fast or work intensively would improve model fit. Care should also be taken while making comparisons in the constructs across time. Further research should investigate invariance across occupations or socio-economic classes.

  20. Control Method Based on Demand Response Needs of Isolated Bus Regulation with Series-Resonant Converters for Residential Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    Shu-Huai Zhang

    2017-05-01

    Full Text Available Considering the effects of isolation and high efficiency, a series-resonant DC-DC converter (L-L-C type, with two inductors and a capacitor has been introduced into a residential photovoltaic (PV generation and storage system in this work, and a voltage gain curve upwarp drifting problem was found. In this paper, the reason of upwarp drifting in the voltage gain curve is given, and a new changing topological control method to solve the voltage regulation problem under light load conditions is proposed. Firstly, the ideal and actual first harmonic approximation (FHA models are given, and this drifting problem is ascribed to the multiple peaks of higher-order resonance between resonant tank and parasitic capacitors. Then the paper presents the pulse-frequency-modulation (PFM driver signals control method to translate the full-bridge LLC into a half-bridge LLC converter, and with this method the voltage gain could easily be reduced by half. Based on this method, the whole voltage and resonant current sharing control methods in on-line and off-line mode are proposed. The parameters design and optimization methods are also discussed in detail. Finally, a residential PV system platform based on the proposed parallel 7-kW full-bridge LLC converter is built to verify the proposed control method and theoretical analysis.

  1. Nutrient demand and fungal access to resources control the carbon allocation to the symbiotic partners in tripartite interactions of Medicago truncatula.

    Science.gov (United States)

    Kafle, Arjun; Garcia, Kevin; Wang, Xiurong; Pfeffer, Philip E; Strahan, Gary D; Bücking, Heike

    2018-06-02

    Legumes form tripartite interactions with arbuscular mycorrhizal (AM) fungi and rhizobia, and both root symbionts exchange nutrients against carbon from their host. The carbon costs of these interactions are substantial, but our current understanding of how the host controls its carbon allocation to individual root symbionts is limited. We examined nutrient uptake and carbon allocation in tripartite interactions of Medicago truncatula under different nutrient supply conditions, and when the fungal partner had access to nitrogen, and followed the gene expression of several plant transporters of the SUT and SWEET family. Tripartite interactions led to synergistic growth responses and stimulated the phosphate and nitrogen uptake of the plant. Plant nutrient demand but also fungal access to nutrients played an important role for the carbon transport to different root symbionts, and the plant allocated more carbon to rhizobia under nitrogen demand, but more carbon to the fungal partner when nitrogen was available. These changes in carbon allocation were consistent with changes in the SUT and SWEET expression. Our study provides important insights into how the host plant controls its carbon allocation under different nutrient supply conditions and changes its carbon allocation to different root symbionts to maximize its symbiotic benefits. This article is protected by copyright. All rights reserved.

  2. Temperature and Humidity Control in Air-Conditioned Buildings with lower Energy Demand and increased Indoor Air Quality

    DEFF Research Database (Denmark)

    Paul, Joachim; Martos, E. T.

    2003-01-01

    Air-conditioning is not only a matter of temperature control. Thermal comfort and good indoor air quality are mainly a matter of humidity. Human health and well being may suffer seriously from inadequate humidity and/or too low temperatures in a room. A case study involving supermarket air......%. For indoor air temperature and humidity control, the use of an ice slurry (´Binary Ice´)was compared to conventional chilled water. The use of Binary Ice instead of chilled water makes the air handling and air distribution installation much simpler, recirculation of air becomes obsolete, and a higher portion...... of ambient air can be supplied, thus improving the indoor air quality still further. Reheating of air is not necessary when using Binary Ice. The introduction of chilled air into a room requires a different type of air outlet, however. When using Binary Ice, energy savings are high for climates with low...

  3. Three-Dimensional Printed Poly(vinyl alcohol) Substrate with Controlled On-Demand Degradation for Transient Electronics.

    Science.gov (United States)

    Yoon, Jinsu; Han, Jungmin; Choi, Bongsik; Lee, Yongwoo; Kim, Yeamin; Park, Jinhee; Lim, Meehyun; Kang, Min-Ho; Kim, Dae Hwan; Kim, Dong Myong; Kim, Sungho; Choi, Sung-Jin

    2018-05-25

    Electronics that degrade after stable operation for a desired operating time, called transient electronics, are of great interest in many fields, including biomedical implants, secure memory devices, and environmental sensors. Thus, the development of transient materials is critical for the advancement of transient electronics and their applications. However, previous reports have mostly relied on achieving transience in aqueous solutions, where the transience time is largely predetermined based on the materials initially selected at the beginning of the fabrication. Therefore, accurate control of the transience time is difficult, thereby limiting their application. In this work, we demonstrate transient electronics based on a water-soluble poly(vinyl alcohol) (PVA) substrate on which carbon nanotube (CNT)-based field-effect transistors were fabricated. We regulated the structural parameters of the PVA substrate using a three-dimensional (3D) printer to accurately control and program the transience time of the PVA substrate in water. The 3D printing technology can produce complex objects directly, thus enabling the efficient fabrication of a transient substrate with a prescribed and controlled transience time. In addition, the 3D printer was used to develop a facile method for the selective and partial destruction of electronics.

  4. Directive and nondirective social support in the workplace - is this social support distinction important for subjective health complaints, job satisfaction, and perception of job demands and job control?

    Science.gov (United States)

    Johnsen, Tone Langjordet; Eriksen, Hege Randi; Indahl, Aage; Tveito, Torill Helene

    2018-05-01

    Social support is associated with well-being and positive health outcomes. However, positive outcomes of social support might be more dependent on the way support is provided than the amount of support received. A distinction can be made between directive social support, where the provider resumes responsibility, and nondirective social support, where the receiver has the control. This study examined the relationship between directive and nondirective social support, and subjective health complaints, job satisfaction and perception of job demands and job control. A survey was conducted among 957 Norwegian employees, working in 114 private kindergartens (mean age 40.7 years, SD = 10.5, 92.8% female), as part of a randomized controlled trial. This study used only baseline data. A factor analysis of the Norwegian version of the Social Support Inventory was conducted, identifying two factors: nondirective and directive social support. Hierarchical regression analyses were then performed. Nondirective social support was related to fewer musculoskeletal and pseudoneurological complaints, higher job satisfaction, and the perception of lower job demands and higher job control. Directive social support had the opposite relationship, but was not statistically significant for pseudoneurological complaints. It appears that for social support to be positively related with job characteristics and subjective health complaints, it has to be nondirective. Directive social support was not only without any association, but had a significant negative relationship with several of the variables. Nondirective social support may be an important factor to consider when aiming to improve the psychosocial work environment. Clinicaltrials.gov: NCT02396797. Registered 23 March 2015.

  5. Optimal Control of a Make-to-Stock System with Outsourced Production and Price-Sensitive Demand

    Directory of Open Access Journals (Sweden)

    Liuxin Chen

    2014-01-01

    and a choice of either high or low price, the system decides at any point in time whether to produce or even outsource for additional capacity as well as which price to sell the product at. We show in the paper that the optimal control policy is of dynamic threshold type: all decisions are based on the product inventory position which represents the state of the system; there is a state dependent base stock level to decide on production and a higher level on outsourcing; and there is a state dependent threshold which divides the choice of high and low prices.

  6. Store-directed price promotions and communications strategies improve healthier food supply and demand: impact results from a randomized controlled, Baltimore City store-intervention trial.

    Science.gov (United States)

    Budd, Nadine; Jeffries, Jayne K; Jones-Smith, Jessica; Kharmats, Anna; McDermott, Ann Yelmokas; Gittelsohn, Joel

    2017-12-01

    Small food store interventions show promise to increase healthy food access in under-resourced areas. However, none have tested the impact of price discounts on healthy food supply and demand. We tested the impact of store-directed price discounts and communications strategies, separately and combined, on the stocking, sales and prices of healthier foods and on storeowner psychosocial factors. Factorial design randomized controlled trial. Twenty-four corner stores in low-income neighbourhoods of Baltimore City, MD, USA. Stores were randomized to pricing intervention, communications intervention, combined pricing and communications intervention, or control. Stores that received the pricing intervention were given a 10-30 % price discount by wholesalers on selected healthier food items during the 6-month trial. Communications stores received visual and interactive materials to promote healthy items, including signage, taste tests and refrigerators. All interventions showed significantly increased stock of promoted foods v. There was a significant treatment effect for daily unit sales of healthy snacks (β=6·4, 95 % CI 0·9, 11·9) and prices of healthy staple foods (β=-0·49, 95 % CI -0·90, -0·03) for the combined group v. control, but not for other intervention groups. There were no significant intervention effects on storeowner psychosocial factors. All interventions led to increased stock of healthier foods. The combined intervention was effective in increasing sales of healthier snacks, even though discounts on snacks were not passed to the consumer. Experimental research in small stores is needed to understand the mechanisms by which store-directed price promotions can increase healthy food supply and demand.

  7. Do psychological job demands, decision control and social support predictreturn to work three months after a return-to-work (RTW) programme? The rapid-RTW cohort study.

    Science.gov (United States)

    Haveraaen, Lise A; Skarpaas, Lisebet S; Berg, John E; Aas, Randi W

    2015-01-01

    Long-term sickness absence is a considerable health and economic problem in the industrialised world. Factors that might predict return to work (RTW) are therefore of interest. To examine the impact of psychosocial work characteristics on RTW three months after the end of a RTW programme. A cohort study of 251 sick-listed employees from 40 different treatment and rehabilitation services in Norway recruited from February to December 2012. The Job Content Questionnaire was used to gather information on the psychosocial work conditions. Full or partial RTW was measured three months after the end of the RTW programme, using data from the national sickness absence register. Logistic regression analyses were performed to investigate the association between the psychosocial work characteristics and RTW. Having low psychological job demands (OR = 0.4, 95% CI: 0.2-0.9), high co-worker- (OR = 3.4, 95% CI: 1.5-5.8), and supervisor support (OR = 3.4, 95% CI: 1.6-7.3), and being in a low-strain job (low job demands and high control) (OR = 4.6, 95% CI: 1.1-18.6) were predictive of being in work three months after the end of the RTW programme, after adjusting for several potential prognostic factors. Interventions aimed at returning people to work might benefit from putting more emphasise on psychosocial work characteristics in the future.

  8. Impact of the demand for 'proxy assent' on recruitment to a randomised controlled trial of vaccination testing in care homes.

    Science.gov (United States)

    Whelan, Paul James; Walwyn, Rebecca; Gaughran, Fiona; Macdonald, Alastair

    2013-01-01

    Legal frameworks are in place to protect those who lack the capacity to consent to research, such as the Mental Capacity Act in the UK. Assent is sought instead from a proxy, usually a relative. However, the same legislation may, perversely, affect the welfare of those who lack capacity and of others by hindering the process of recruitment into otherwise potentially beneficial research. In addition, the onus of responsibility is moved from those who know most about the study (ie, the scientific community) to those who know less (the proxies). In this paper, we describe the characteristics of a sample at different stages of the recruitment process of an influenza vaccine-based randomised control trial in elderly care home residents (the FEVER study). 62% (602/968) of potential subjects lacked capacity but only 29% (80/277) of those actually randomised. Older age, being female and living in an Elderly Mentally Ill care home were the only variables associated with lacking capacity. Considering this was a study based in a care home setting where the prevalence of dementia approximates 80%, the trial, like many others, was thus significantly biased. We believe that difficulties seeking proxy assent contributed significantly to this problem. Further thought should be given to how assent to enter research for those who lack capacity should be provided, and we suggest avenues for further discussion such as independent risk/benefit expert panels.

  9. Effectiveness of a participatory physical and psychosocial intervention to balance the demands and resources of industrial workers: A cluster-randomized controlled trial.

    Science.gov (United States)

    Gupta, Nidhi; Wåhlin-Jacobsen, Christian Dyrlund; Abildgaard, Johan Simonsen; Henriksen, Louise Nøhr; Nielsen, Karina; Holtermann, Andreas

    2018-01-01

    Objectives The aim of this study was to evaluate the effectiveness of a participatory physical and psychosocial workplace intervention (known as PIPPI) on work ability and recovery among industrial workers. Methods Eligible workers were cluster-randomized into intervention (N=193) and control (N=222) groups. Intervention group members participated in three workshops where they mapped positive and negative aspects of their physical and psychosocial work environment and developed action plans addressing the highlighted issues, which were subsequently implemented by the participants. Questionnaire-based data on work ability and recovery were collected at baseline and 8-, 10- and 12-month follow-up. Data on productivity, well-being, mental health, and physical demands and resources were collected at baseline and 12-month follow-up. Results The intervention was delivered and received as planned (100% planned workshops conducted, 69% [standard deviation (SD) 7%] participation in workshops) and with a response rate of 76% (SD 8%) to the questionnaires. No significant between-group improvements for any of the outcomes were found in intention-to-treat multi-level mixed models. On the contrary, tendencies were observed for poorer recovery and reduced work ability in the intervention compared to control group. Conclusion The intervention did not improve the outcomes. This result can have several explanations, such as a regression-toward-the-mean effect or that the intervention might have put an additional burden on the workers already facing high work demands. In addition, there may have been an insufficient match between the intervention components implemented and the predetermined outcomes, and implementation may have been unsuccessful. These potential explanations need to be investigated using process evaluation data.

  10. Socioeconomic inequalities in physical and mental functioning of British, Finnish, and Japanese civil servants: role of job demand, control, and work hours.

    Science.gov (United States)

    Sekine, Michikazu; Chandola, Tarani; Martikainen, Pekka; Marmot, Michael; Kagamimori, Sadanobu

    2009-11-01

    This study aims to evaluate whether the pattern of socioeconomic inequalities in physical and mental functioning as measured by the Short Form 36 (SF-36) differs among employees in Britain, Finland, and Japan and whether work characteristics contribute to some of the health inequalities. The participants were 7340 (5122 men and 2218 women) British employees, 2297 (1638 men and 659 women) Japanese employees, and 8164 (1649 men and 6515 women) Finnish employees. All the participants were civil servants aged 40-60 years. Both male and female low grade employees had poor physical functioning in all cohorts. British and Japanese male low grade employees tended to have poor mental functioning but the associations were significant only for Japanese men. No consistent employment-grade differences in mental functioning were observed among British and Japanese women. Among Finnish men and women, high grade employees had poor mental functioning. In all cohorts, high grade employees had high control, high demands and long work hours. The grade differences in poor physical functioning and disadvantaged work characteristics among non-manual workers were somewhat smaller in the Finnish cohort than in the British and Japanese cohorts. Low control, high demands, and both short and long work hours were associated with poor functioning. When work characteristics were adjusted for, the socioeconomic differences in poor functioning were mildly attenuated in men, but the differences increased slightly in women. This study reconfirms the generally observed pattern of socioeconomic inequalities in health for physical functioning but not for mental functioning. The role of work characteristics in the relationship between socioeconomic status and health differed between men and women but was modest overall. We suggest that these differences in the pattern and magnitude of grade differences in work characteristics and health among the 3 cohorts may be attributable to the different welfare

  11. Effect of Postural Control Demands on Early Visual Evoked Potentials during a Subjective Visual Vertical Perception Task in Adolescents with Idiopathic Scoliosis.

    Science.gov (United States)

    Chang, Yi-Tzu; Meng, Ling-Fu; Chang, Chun-Ju; Lai, Po-Liang; Lung, Chi-Wen; Chern, Jen-Suh

    2017-01-01

    Subjective visual vertical (SVV) judgment and standing stability were separately investigated among patients with adolescent idiopathic scoliosis (AIS). Although, one study has investigated the central mechanism of stability control in the AIS population, the relationships between SVV, decreased standing stability, and AIS have never been investigated. Through event-related potentials (ERPs), the present study examined the effect of postural control demands (PDs) on AIS central mechanisms related to SVV judgment and standing stability to elucidate the time-serial stability control process. Thirteen AIS subjects (AIS group) and 13 age-matched adolescents (control group) aged 12-18 years were recruited. Each subject had to complete an SVV task (i.e., the modified rod-and-frame [mRAF] test) as a stimulus, with online electroencephalogram recording being performed in the following three standing postures: feet shoulder-width apart standing, feet together standing, and tandem standing. The behavioral performance in terms of postural stability (center of pressure excursion), SVV (accuracy and reaction time), and mRAF-locked ERPs (mean amplitude and peak latency of the P1, N1, and P2 components) was then compared between the AIS and control groups. In the behavioral domain, the results revealed that only the AIS group demonstrated a significantly accelerated SVV reaction time as the PDs increased. In the cerebral domain, significantly larger P2 mean amplitudes were observed during both feet shoulder-width-apart standing and feet together standing postures compared with during tandem standing. No group differences were noted in the cerebral domain. The results indicated that (1) during the dual-task paradigm, a differential behavioral strategy of accelerated SVV reaction time was observed in the AIS group only when the PDs increased and (2) the decrease in P2 mean amplitudes with the increase in the PD levels might be direct evidence of the competition for central

  12. Effect of Postural Control Demands on Early Visual Evoked Potentials during a Subjective Visual Vertical Perception Task in Adolescents with Idiopathic Scoliosis

    Directory of Open Access Journals (Sweden)

    Yi-Tzu Chang

    2017-06-01

    Full Text Available Subjective visual vertical (SVV judgment and standing stability were separately investigated among patients with adolescent idiopathic scoliosis (AIS. Although, one study has investigated the central mechanism of stability control in the AIS population, the relationships between SVV, decreased standing stability, and AIS have never been investigated. Through event-related potentials (ERPs, the present study examined the effect of postural control demands (PDs on AIS central mechanisms related to SVV judgment and standing stability to elucidate the time-serial stability control process. Thirteen AIS subjects (AIS group and 13 age-matched adolescents (control group aged 12–18 years were recruited. Each subject had to complete an SVV task (i.e., the modified rod-and-frame [mRAF] test as a stimulus, with online electroencephalogram recording being performed in the following three standing postures: feet shoulder-width apart standing, feet together standing, and tandem standing. The behavioral performance in terms of postural stability (center of pressure excursion, SVV (accuracy and reaction time, and mRAF-locked ERPs (mean amplitude and peak latency of the P1, N1, and P2 components was then compared between the AIS and control groups. In the behavioral domain, the results revealed that only the AIS group demonstrated a significantly accelerated SVV reaction time as the PDs increased. In the cerebral domain, significantly larger P2 mean amplitudes were observed during both feet shoulder-width-apart standing and feet together standing postures compared with during tandem standing. No group differences were noted in the cerebral domain. The results indicated that (1 during the dual-task paradigm, a differential behavioral strategy of accelerated SVV reaction time was observed in the AIS group only when the PDs increased and (2 the decrease in P2 mean amplitudes with the increase in the PD levels might be direct evidence of the competition for

  13. mTORC1 Balances Cellular Amino Acid Supply with Demand for Protein Synthesis through Post-transcriptional Control of ATF4

    Directory of Open Access Journals (Sweden)

    Yeonwoo Park

    2017-05-01

    Full Text Available The mammalian target of rapamycin complex 1 (mTORC1 is a master regulator of cell growth that is commonly deregulated in human diseases. Here we find that mTORC1 controls a transcriptional program encoding amino acid transporters and metabolic enzymes through a mechanism also used to regulate protein synthesis. Bioinformatic analysis of mTORC1-responsive mRNAs identified a promoter element recognized by activating transcription factor 4 (ATF4, a key effector of the integrated stress response. ATF4 translation is normally induced by the phosphorylation of eukaryotic initiation factor 2 alpha (eIF2α through a mechanism that requires upstream open reading frames (uORFs in the ATF4 5′ UTR. mTORC1 also controls ATF4 translation through uORFs, but independently of changes in eIF2α phosphorylation. mTORC1 instead employs the 4E-binding protein (4E-BP family of translation repressors. These results link mTORC1-regulated demand for protein synthesis with an ATF4-regulated transcriptional program that controls the supply of amino acids to the translation machinery.

  14. Function and Content of Maternal Demands: Developmental Significance of Early Demands for Competent Action.

    Science.gov (United States)

    Kuczynski, Leon; Kochanska, Grazyna

    1995-01-01

    Examined mothers' demands during mothers' interactions with their 1.5- to 3.5-year olds. Mothers with authoritative child-rearing attitudes emphasized proactive, competence-oriented demands and avoided regulatory control. Maternal demands for competent action predicted fewer behavior problems in their children at age five; maternal demands focused…

  15. Informed, advance refusals of treatment by people with severe mental illness in a randomised controlled trial of joint crisis plans: demand, content and correlates.

    Science.gov (United States)

    Henderson, Claire; Farrelly, Simone; Flach, Clare; Borschmann, Rohan; Birchwood, Max; Thornicroft, Graham; Waheed, Waquas; Szmukler, George

    2017-11-24

    In the UK, crisis planning for mental health care should acknowledge the right to make an informed advance treatment refusal under the Mental Capacity Act 2005. Our aims were to estimate the demand for such treatment refusals within a sample of service users who had had a recent hospital admission for psychosis or bipolar disorder, and to examine the relationship between refusals, and service user characteristics. To identify refusals we conducted content analysis of Joint Crisis Plans, which are plans formulated by service users and their clinical team with involvement from an external facilitator, and routine care plans in sub-samples from a multi-centre randomised controlled trial of Joint Crisis Plans (plus routine mental health care) versus routine care alone (CRIMSON) in England. Factors hypothesised to be associated with refusals were identified using the trial data collected through baseline interviews of service users and clinicians and collection of routine clinical data. Ninety-nine of 221 (45%) of the Joint Crisis Plans contained a treatment refusal compared to 10 of 424 (2.4%) baseline routine care plans. No Joint Crisis Plans recorded disagreement with refusals on the part of clinicians. Among those with completed Joint Crisis Plans, adjusted analyses indicated a significant association between treatment refusals and perceived coercion at baseline (odds ratio = 1.21, 95% CI 1.02-1.43), but not with baseline working alliance or a past history of involuntary admission. We demonstrated significant demand for written treatment refusals in line with the Mental Capacity Act 2005, which had not previously been elicited by the process of treatment planning. Future treatment/crisis plans should incorporate the opportunity for service users to record a treatment refusal during the drafting of such plans. ISRCTN11501328 Registered 13th March 2008.

  16. Joint Optimization of Distribution Network Design and Two-Echelon Inventory Control with Stochastic Demand and CO2 Emission Tax Charges.

    Science.gov (United States)

    Li, Shuangyan; Li, Xialian; Zhang, Dezhi; Zhou, Lingyun

    2017-01-01

    This study develops an optimization model to integrate facility location and inventory control for a three-level distribution network consisting of a supplier, multiple distribution centers (DCs), and multiple retailers. The integrated model addressed in this study simultaneously determines three types of decisions: (1) facility location (optimal number, location, and size of DCs); (2) allocation (assignment of suppliers to located DCs and retailers to located DCs, and corresponding optimal transport mode choices); and (3) inventory control decisions on order quantities, reorder points, and amount of safety stock at each retailer and opened DC. A mixed-integer programming model is presented, which considers the carbon emission taxes, multiple transport modes, stochastic demand, and replenishment lead time. The goal is to minimize the total cost, which covers the fixed costs of logistics facilities, inventory, transportation, and CO2 emission tax charges. The aforementioned optimal model was solved using commercial software LINGO 11. A numerical example is provided to illustrate the applications of the proposed model. The findings show that carbon emission taxes can significantly affect the supply chain structure, inventory level, and carbon emission reduction levels. The delay rate directly affects the replenishment decision of a retailer.

  17. Joint Optimization of Distribution Network Design and Two-Echelon Inventory Control with Stochastic Demand and CO2 Emission Tax Charges.

    Directory of Open Access Journals (Sweden)

    Shuangyan Li

    Full Text Available This study develops an optimization model to integrate facility location and inventory control for a three-level distribution network consisting of a supplier, multiple distribution centers (DCs, and multiple retailers. The integrated model addressed in this study simultaneously determines three types of decisions: (1 facility location (optimal number, location, and size of DCs; (2 allocation (assignment of suppliers to located DCs and retailers to located DCs, and corresponding optimal transport mode choices; and (3 inventory control decisions on order quantities, reorder points, and amount of safety stock at each retailer and opened DC. A mixed-integer programming model is presented, which considers the carbon emission taxes, multiple transport modes, stochastic demand, and replenishment lead time. The goal is to minimize the total cost, which covers the fixed costs of logistics facilities, inventory, transportation, and CO2 emission tax charges. The aforementioned optimal model was solved using commercial software LINGO 11. A numerical example is provided to illustrate the applications of the proposed model. The findings show that carbon emission taxes can significantly affect the supply chain structure, inventory level, and carbon emission reduction levels. The delay rate directly affects the replenishment decision of a retailer.

  18. Time Demand and Radiation Dose in 3D-Fluoroscopy-based Navigation-assisted 3D-Fluoroscopy-controlled Pedicle Screw Instrumentations.

    Science.gov (United States)

    Balling, Horst

    2018-05-01

    Prospective single-center cohort study to record additional time requirements and radiation dose in navigation-assisted O-arm-controlled pedicle screw (PS) instrumentations. The aim of this study was to evaluate amount of extra-time and radiation dose for navigation-assisted PS instrumentations of the thoracolumbosacral spine using O-arm 3D-real-time-navigation (O3DN) compared to non-navigated spinal procedures (NNSPs) with a single C-arm and postoperative computed tomography (CT) scan for controlling PS positions. 3D-navigation is reported to enhance PS insertion accuracy. But time-consuming navigational steps and considerable additional radiation doses seem to limit this modern technique's attraction. A detailed analysis of additional time demand and extra-radiation dose in 3D-navigated spine surgery is not provided in literature, yet. From February 2011 through July 2015, 306 consecutive posterior instrumentations were performed in vertebral levels T10-S1 using O3DN for PS insertion. The duration of procedure-specific navigational steps of the overall collective (I) and the last cohort of 50 consecutive O3DN-surgeries (II) was compared to the average duration of analogous surgical steps in 100 consecutive NNSP using a single C-arm. 3D-radiation dose (dose-length-product, DLP) of navigational and postinstrumentation O-arm scans in group I and II was compared to the average DLP of 100 diagnostic lumbar CT scans. The average presurgical time from patient positioning on the operating table to skin incision was 46.2 ± 10.1 minutes (O3DN, I) and 40.6 ± 9.8 minutes (O3DN, II) versus 30.6 ± 8.3 minutes (NNSP) (P demand of 13.0 minutes compared to NNSP, and with a total DLP below that of a diagnostic lumbar CT scan (P ≈ 0.81). 4.

  19. [Psychosocial stress and disease risks in occupational life. Results of international studies on the demand-control and the effort-reward imbalance models].

    Science.gov (United States)

    Siegrist, J; Dragano, N

    2008-03-01

    Given the far-reaching changes of modern working life, psychosocial stress at work has received increased attention. Its influence on stress-related disease risks is analysed with the help of standardised measurements based on theoretical models. Two such models have gained special prominence in recent years, the demand-control model and the effort-reward imbalance model. The former model places its emphasis on a distinct combination of job characteristics, whereas the latter model's focus is on the imbalance between efforts spent and rewards received in turn. The predictive power of these models with respect to coronary or cardiovascular disease and depression was tested in a number of prospective epidemiological investigations. In summary, twofold elevated disease risks are observed. Effects on cardiovascular disease are particularly pronounced among men, whereas no gender differences are observed for depression. Additional evidence derived from experimental and ambulatory monitoring studies supplements this body of findings. Current scientific evidence justifies an increased awareness and assessment of these newly discovered occupational risks, in particular by occupational health professionals. Moreover, structural and interpersonal measures of stress prevention and health promotion at work are warranted, with special emphasis on gender differences.

  20. A periodic review integrated inventory model with controllable safety stock and setup cost under service level constraint and distribution-free demand

    Science.gov (United States)

    Kurdhi, N. A.; Jamaluddin, A.; Jauhari, W. A.; Saputro, D. R. S.

    2017-06-01

    In this study, we consider a stochastic integrated manufacturer-retailer inventory model with service level constraint. The model analyzed in this article considers the situation in which the vendor and the buyer establish a long-term contract and strategic partnership to jointly determine the best strategy. The lead time and setup cost are assumed can be controlled by an additional crashing cost and an investment, respectively. It is assumed that shortages are allowed and partially backlogged on the buyer’s side, and that the protection interval (i.e., review period plus lead time) demand distribution is unknown but has given finite first and second moments. The objective is to apply the minmax distribution free approach to simultaneously optimize the review period, the lead time, the setup cost, the safety factor, and the number of deliveries in order to minimize the joint total expected annual cost. The service level constraint guarantees that the service level requirement can be satisfied at the worst case. By constructing Lagrange function, the analysis regarding the solution procedure is conducted, and a solution algorithm is then developed. Moreover, a numerical example and sensitivity analysis are given to illustrate the proposed model and to provide some observations and managerial implications.

  1. Quantitative relations between chemical oxygen demand concentration and its influence factors in the sluice-controlled river reaches of Shaying River, China.

    Science.gov (United States)

    Dou, Ming; Li, Guiqiu; Li, Congying

    2015-01-01

    Recent research on the effects of dam and sluice construction on the water environment has attracted extensive attention from academia and governments alike. Because the operation of sluices greatly alters environmental factors such as water flow and sediment load, the water quality in sluice-controlled river reaches (SCRRs) undergoes complex changes compared with those in normal reaches. This work used river reaches near the Huaidian Sluice in Shaying River of China as a case study to analyse the effects of sluice operation on water quality evolution in SCRRs. The most influential factors affecting the rate of change in chemical oxygen demand (COD) concentration in SCRRs were identified through water quality monitoring experiments performed under various modes of sluice operation and by applying a statistical method 'partial correlation analysis'. Then, a hydrodynamic model incorporating sluice operation and a water quality transport and transform model incorporating the release of endogenous loads were developed. Using these two models, the processes of temporal and spatial change of COD concentrations in the SCRRs were simulated under various scenarios designed to represent the dominant factors of influence. Finally, the simulation results were used to develop empirical relationships between the rate of change in COD concentrations and the dominant factors of influence. The results reveal that three factors, i.e., water inflow concentration, gate opening size, and gate opening number, are the dominant factors of influence, and there are logarithmic relationships between the rate of change in COD concentration in the SCRRs and these factors.

  2. On-Demand Telemetry

    Data.gov (United States)

    National Aeronautics and Space Administration — AFRC has previously investigated the use of Network Based Telemetry. We will be building on that research to enable On-Demand Telemetry. On-Demand Telemetry is a way...

  3. Money Demand in Latvia

    OpenAIRE

    Ivars Tillers

    2004-01-01

    The econometric analysis of the demand for broad money in Latvia suggests a stable relationship of money demand. The analysis of parameter exogeneity indicates that the equilibrium adjustment is driven solely by the changes in the amount of money. The demand for money in Latvia is characterised by relatively high income elasticity typical for the economy in a monetary expansion phase. Due to stability, close fit of the money demand function and rapid equilibrium adjustment, broad money aggreg...

  4. Demand for male contraception.

    Science.gov (United States)

    Dorman, Emily; Bishai, David

    2012-10-01

    The biological basis for male contraception was established decades ago, but despite promising breakthroughs and the financial burden men increasingly bear due to better enforcement of child support policies, no viable alternative to the condom has been brought to market. Men who wish to control their fertility must rely on female compliance with contraceptives, barrier methods, vasectomy or abstinence. Over the last 10 years, the pharmaceutical industry has abandoned most of its investment in the field, leaving only nonprofit organisations and public entities pursuing male contraception. Leading explanations are uncertain forecasts of market demand pitted against the need for critical investments to demonstrate the safety of existing candidate products. This paper explores the developments and challenges in male contraception research. We produce preliminary estimates of potential market size for a safe and effective male contraceptive based on available data to estimate the potential market for a novel male method.

  5. Electricity demand forecasting techniques

    International Nuclear Information System (INIS)

    Gnanalingam, K.

    1994-01-01

    Electricity demand forecasting plays an important role in power generation. The two areas of data that have to be forecasted in a power system are peak demand which determines the capacity (MW) of the plant required and annual energy demand (GWH). Methods used in electricity demand forecasting include time trend analysis and econometric methods. In forecasting, identification of manpower demand, identification of key planning factors, decision on planning horizon, differentiation between prediction and projection (i.e. development of different scenarios) and choosing from different forecasting techniques are important

  6. Sex inequalities in physical and mental functioning of British, Finnish, and Japanese civil servants: role of job demand, control and work hours.

    Science.gov (United States)

    Sekine, Michikazu; Tatsuse, Takashi; Kagamimori, Sadanobu; Chandola, Tarani; Cable, Noriko; Marmot, Michael; Martikainen, Pekka; Lallukka, Tea; Rahkonen, Ossi; Lahelma, Eero

    2011-08-01

    In general, women report more physical and mental symptoms than men. International comparisons of countries with different welfare state regimes may provide further understanding of the social determinants of sex inequalities in health. This study aims to evaluate (1) whether there are sex inequalities in health functioning as measured by the Short Form 36 (SF-36), and (2) whether work characteristics contribute to the sex inequalities in health among employees from Britain, Finland, and Japan, representing liberal, social democratic, and conservative welfare state regimes, respectively. The participants were 7340 (5122 men and 2218 women) British employees, 2297 (1638 men and 659 women) Japanese employees, and 8164 (1649 men and 6515 women) Finnish employees. All the participants were civil servants aged 40-60 years. We found that more women than men tended to have disadvantaged work characteristics (i.e. low employment grade, low job control, high job demands, and long work hours) but such sex differences were relatively smaller among employees from Finland, where more gender equal policies exist than Britain and Japan. The age-adjusted odds ratio (OR) of women for poor physical functioning was the largest for British women (OR = 2.08), followed by for Japanese women (OR = 1.72), and then for Finnish women (OR = 1.51). The age-adjusted OR of women for poor mental functioning was the largest for Japanese women (OR = 1.91), followed by for British women (OR = 1.45), and then for Finnish women (OR = 1.07). Thus, sex differences in physical and mental health was the smallest in the Finnish population. The larger the sex differences in work characteristics, the larger the sex differences in health and the reduction in the sex differences in health after adjustment for work characteristics. These results suggest that egalitarian and gender equal policies may contribute to smaller sex differences in health, through smaller differences in disadvantaged work

  7. A cross-sectional study of the relationship between job demand-control, effort-reward imbalance and cardiovascular heart disease risk factors

    Directory of Open Access Journals (Sweden)

    Söderberg Mia

    2012-12-01

    Full Text Available Abstract Background This cross-sectional study explored relationships between psychosocial work environment, captured by job demand-control (JDC and effort-reward imbalance (ERI, and seven cardiovascular heart disease (CHD risk factors in a general population. Method The sampled consists of randomly-selected men and women from Gothenburg, Sweden and the city’s surrounding metropolitan areas. Associations between psychosocial variables and biomarkers were analysed with multiple linear regression adjusted for age, smoking, education and occupational status. Results The study included 638 men and 668 women aged 24–71. Analysis between JDC and CHD risk factors illustrated that, for men, JDC was associated with impaired scores in several biomarkers, especially among those in high strain jobs. For women, there were no relationships between JDC and biomarkers. In the analysis of links between ERI and CHD risk factors, most associations tested null. The only findings were raised triglycerides and BMI among men in the fourth quartile of the ERI-ratio distribution, and lowered LDL-cholesterol for women. An complementary ERI analysis, combining high/low effort and reward into categories, illustrated lowered triglycerides and elevated HDL-cholesterol values among women reporting high efforts and high rewards, compared to women experiencing low effort and high reward. Conclusions There were some associations between psychosocial stressors and CHD risk factors. The cross-sectional design did not allow conclusions about causality but some results indicated gender differences regarding sensitivity to work stressors and also how the models might capture different psychosocial dimensions.

  8. Criteria for demand response systems

    NARCIS (Netherlands)

    Lampropoulos, I.; Kling, W.L.; Bosch, van den P.P.J.; Ribeiro, P.F.; Berg, van den J.

    2013-01-01

    The topic of demand side management is currently becoming more important than ever, in parallel with the further deregulation of the electricity sector, and the increasing integration of renewable energy sources. A historical review of automation integration in power system control assists in

  9. Smart Buildings and Demand Response

    Science.gov (United States)

    Kiliccote, Sila; Piette, Mary Ann; Ghatikar, Girish

    2011-11-01

    Advances in communications and control technology, the strengthening of the Internet, and the growing appreciation of the urgency to reduce demand side energy use are motivating the development of improvements in both energy efficiency and demand response (DR) systems in buildings. This paper provides a framework linking continuous energy management and continuous communications for automated demand response (Auto-DR) in various times scales. We provide a set of concepts for monitoring and controls linked to standards and procedures such as Open Automation Demand Response Communication Standards (OpenADR). Basic building energy science and control issues in this approach begin with key building components, systems, end-uses and whole building energy performance metrics. The paper presents a framework about when energy is used, levels of services by energy using systems, granularity of control, and speed of telemetry. DR, when defined as a discrete event, requires a different set of building service levels than daily operations. We provide examples of lessons from DR case studies and links to energy efficiency.

  10. WATER DEMAND PREDICTION USING ARTIFICIAL NEURAL ...

    African Journals Online (AJOL)

    This paper presents Hourly water demand prediction at the demand nodes of a water distribution network using NeuNet Pro 2.3 neural network software and the monitoring and control of water distribution using supervisory control. The case study is the Laminga Water Treatment Plant and its water distribution network, Jos.

  11. Electricity demand in Kazakhstan

    International Nuclear Information System (INIS)

    Atakhanova, Zauresh; Howie, Peter

    2007-01-01

    Properties of electricity demand in transition economies have not been sufficiently well researched mostly due to data limitations. However, information on the properties of electricity demand is necessary for policy makers to evaluate effects of price changes on different consumers and obtain demand forecasts for capacity planning. This study estimates Kazakhstan's aggregate demand for electricity as well as electricity demand in the industrial, service, and residential sectors using regional data. Firstly, our results show that price elasticity of demand in all sectors is low. This fact suggests that there is considerable room for price increases necessary to finance generation and distribution system upgrading. Secondly, we find that income elasticity of demand in the aggregate and all sectoral models is less than unity. Of the three sectors, electricity demand in the residential sector has the lowest income elasticity. This result indicates that policy initiatives to secure affordability of electricity consumption to lower income residential consumers may be required. Finally, our forecast shows that electricity demand may grow at either 3% or 5% per year depending on rates of economic growth and government policy regarding price increases and promotion of efficiency. We find that planned supply increases would be sufficient to cover growing demand only if real electricity prices start to increase toward long-run cost-recovery levels and policy measures are implemented to maintain the current high growth of electricity efficiency

  12. Demand flexibility from residential heat pump

    DEFF Research Database (Denmark)

    Bhattarai, Bishnu Prasad; Bak-Jensen, Birgitte; Pillai, Jayakrishnan Radhakrishna

    2014-01-01

    Demand response (DR) is considered as a potentially effective tool to compensate generation intermittency imposed by renewable sources. Further, DR can instigate to offer optimum asset utilization and to avoid or delay the need for new infrastructure investment. Being a sizable load together...... with high thermal time constant, heat pumps (HP) can offer a great deal of flexibility in the future intelligent grids especially to compensate fluctuating generation. However, the HP flexibility is highly dependent on thermal demand profile, namely hot water and space heating demand. This paper proposes...... price based scheduling followed by a demand dispatch based central control and a local voltage based adaptive control, to realize HP demand flexibility. Two-step control architecture, namely local primary control encompassed by the central coordinative control, is proposed to implement...

  13. Innovation and Demand

    DEFF Research Database (Denmark)

    Andersen, Esben Sloth

    2007-01-01

    the demand-side of markets in the simplest possible way. This strategy has allowed a gradual increase in the sophistication of supply-side aspects of economic evolution, but the one-sided focus on supply is facing diminishing returns. Therefore, demand-side aspects of economic evolution have in recent years...... received increased attention. The present paper argues that the new emphasis on demand-side factors is quite crucial for a deepened understanding of economic evolution. The major reasons are the following: First, demand represents the core force of selection that gives direction to the evolutionary process....... Second, firms' innovative activities relate, directly or indirectly, to the structure of expected and actual demand. Third, the demand side represents the most obvious way of turning to the much-needed analysis of macro-evolutionary change of the economic system....

  14. Dissolved Organic In Natural and Polluted Waters: Methodology and Results of Running Control of Chemical Oxygen Demand (cod) For The Inland and Marine Aquatic System

    Science.gov (United States)

    Melentyev, K. V.; Worontsov, A. M.

    Current control of dissolved organic matter in natural and waste waters is the definition traditionally of chemical oxygen demand (COD) -- one of the basic parameters of quality of water. According to the International Standard (ISO 6060), it requires not less than one hour, while in many cases the operative information about amount of dissolved organic matter in aquatic environments have importance for prevention of an emergency. The standard method is applicable to waters with meaning of COD above 30 mg O2/l and, as the chloride ion prevents, it could be difficult for assessment of organic matter in sea water. Besides it is based on dichromate oxidation of the sum of organic substances in strong acid conditions at the presence of silver and mercury, that resulted in formation toxic pollutants. Till now attempts of automation of the COD definition in aquatic system were limited, basically, to duplication of the technology submitted the above standard (automatic COD analyzers "SERES Co."-- France, or "Tsvet Co." - Russia). The system of ozone-chemiluminescence automatic control of organic matter in water (CS COD) is offered and designed. Its based on the ozone oxidation of these substances in flowing water system and measurement arising from luminescent effects. CS COD works in real time. An instrument uses for reaction the atmospheric air, doesn't require fill of reagents and doesn't make new toxic pollutants. The system was tested in laboratory, and biochemical control of organic matter in water samples gathered from the river Neva and other polluted inland water areas and basins in St. Petersburg region was fulfilled (distilled water was used as "zero" media). The results of systematization of these measurements are presented. The new special ozone generator and flowing reactor for real-time running control of different waters in natural conditions were developed, and several series of large - scale field experiments onboard research ship were provided

  15. PERFECT DEMAND ILLUSION

    Directory of Open Access Journals (Sweden)

    Alexander Yu. Sulimov

    2015-01-01

    Full Text Available The article is devoted to technique «Perfect demand illusion», which allows to strengthen the competitive advantageof retailers. Also in the paper spells out the golden rules of visual merchandising.The definition of the method «Demand illusion», formulated the conditions of its functioning, and is determined by the mainhypothesis of the existence of this method.Furthermore, given the definition of the «Perfect demand illusion», and describes its additional conditions. Also spells out the advantages of the «Perfect demandillusion», before the «Demand illusion».

  16. Divers of Passenger Demand

    OpenAIRE

    Wittmer, Andreas

    2011-01-01

    -Overview drivers of passenger demand -Driver 1: Economic growth in developing countries -Driver 2: International business travel in developed countries -Driver 3: International leisure travel in developed countries

  17. Climate change and energy demand

    International Nuclear Information System (INIS)

    Hengeveld, H.G.

    1991-01-01

    Climate and weather events affect energy demand in most economic sectors. Linear relationships exist between consumption and heating degree days, and peak electricity demand increases significantly during heat waves. The relative magnitudes of demand changes for a two times carbon dioxide concentration scenario are tabulated, illustrating heating degree days and cooling degree days for 5 Prairie locations. Irrigation, water management, crop seeding and harvesting and weed control are examples of climate-dependent agricultural activities involving significant energy use. The variability of summer season liquid fuel use in the agricultural sector in the Prairie provinces from 1984-1989 shows a relationship between agricultural energy use and regional climate fluctuations. 4 refs., 2 figs., 1 tab

  18. Uranium supply and demand

    Energy Technology Data Exchange (ETDEWEB)

    Spriggs, M J

    1976-01-01

    Papers were presented on the pattern of uranium production in South Africa; Australian uranium--will it ever become available; North American uranium resources, policies, prospects, and pricing; economic and political environment of the uranium mining industry; alternative sources of uranium supply; whither North American demand for uranium; and uranium demand and security of supply--a consumer's point of view. (LK)

  19. Wood supply and demand

    Science.gov (United States)

    Peter J. Ince; David B. McKeever

    2011-01-01

    At times in history, there have been concerns that demand for wood (timber) would be greater than the ability to supply it, but that concern has recently dissipated. The wood supply and demand situation has changed because of market transitions, economic downturns, and continued forest growth. This article provides a concise overview of this change as it relates to the...

  20. The Q(s,S) control policy for the joint replenishment problem extended to the case of correlation among item-demands

    DEFF Research Database (Denmark)

    Larsen, Christian

      We develop an algorithm to compute an optimal Q(s,S) policy for the joint replenishment problem when demands follow a compound correlated Poisson process. It is a non-trivial generalization of the work by Nielsen and Larsen (2005). We make some numerical analyses on two-item problems where we...... compare the optimal Q(s,S) policy to the optimal uncoordinated (s,S) policies. The results indicate that the more negative the correlation the less advantageous it is to coordinate. Therefore, in some cases the degree of correlation determines whether to apply the coordinated Q(s,S) policy...... or the uncoordinated (s,S) policies. Finally, we compare the Q(s,S) policy and the closely connected P(s,S) policy. Here we explain why the Q(s,S) policy is a better choice if item-demands are correlated....

  1. Asian oil demand

    International Nuclear Information System (INIS)

    Fesharaki, F.

    2005-01-01

    This conference presentation examined global oil market development and the role of Asian demand. It discussed plateau change versus cyclical movement in the global oil market; supply and demand issues of OPEC and non-OPEC oil; if high oil prices reduce demand; and the Asian oil picture in the global context. Asian oil demand has accounted for about 50 per cent of the global incremental oil market growth. The presentation provided data charts in graphical format on global and Asia-Pacific incremental oil demand from 1990-2005; Asia oil demand growth for selected nations; real GDP growth in selected Asian countries; and, Asia-Pacific oil production and net import requirements. It also included charts in petroleum product demand for Asia-Pacific, China, India, Japan, and South Korea. Other data charts included key indicators for China's petroleum sector; China crude production and net oil import requirements; China's imports and the share of the Middle East; China's oil exports and imports; China's crude imports by source for 2004; China's imports of main oil products for 2004; India's refining capacity; India's product balance for net-imports and net-exports; and India's trade pattern of oil products. tabs., figs

  2. Pay for load demand - electricity pricing with load demand component

    International Nuclear Information System (INIS)

    Pyrko, Jurek; Sernhed, Kerstin; Abaravicius, Juozas

    2003-01-01

    This publication is part of a project called Direct and Indirect Load Control in Buildings. Peak load problems have attracted considerable attention in Sweden during last three winters, caused by a significant decrease in available reserve power, which is a consequence of political decisions and liberalisation of the electricity market. A possible way to lower peak loads, avoiding electricity shortages and reducing electricity costs both for users and utilities, is to make customers experience the price difference during peak load periods and, in this way, become more aware of their energy consumption pattern and load demand. As of January 1st 2001, one of the Swedish energy utilities - Sollentuna Energi - operating in the Stockholm area, introduced a new electricity tariff with differentiated grid fees based on a mean value of the peak load every month. This tariff was introduced for all residential customers in the service area. The objective of this study is to investigate the extent to which a Load Demand Component, included in electricity pricing, can influence energy use and load demand in residential buildings. What are the benefits and disadvantages for customers and utilities? This paper investigates the impact of the new tariff on the utility and different types of typical residential customers, making comparisons with previous tariff. Keywords Load demand, electricity pricing, tariff, residential customers, energy behaviour

  3. Uranium supply and demand

    International Nuclear Information System (INIS)

    1984-05-01

    This report covers the period 1983 to 1995. It draws together the industry's latest views on future trends in supply and demand, and sets them in their historical context. It devotes less discussion than its predecessors to the technical influences underpinning the Institute's supply and demand forecasts, and more to the factors which influence the market behaviour of the industry's various participants. As the last decade has clearly shown, these latter influences can easily be overlooked when undue attention is given to physical imbalances between supply and demand. (author)

  4. On energy demand

    International Nuclear Information System (INIS)

    Haefele, W.

    1977-01-01

    Since the energy crisis, a number of energy plans have been proposed, and almost all of these envisage some kind of energy demand adaptations or conservation measures, hoping thus to escape the anticipated problems of energy supply. However, there seems to be no clear explanation of the basis on which our foreseeable future energy problems could be eased. And in fact, a first attempt at a more exact definition of energy demand and its interaction with other objectives, such as economic ones, shows that it is a highly complex concept which we still hardly understand. The article explains in some detail why it is so difficult to understand energy demand

  5. Church heating systems demand competence and accuracy. Microprocessor-controlled underfloor heating saves inventory stock and budget. Verlangen Kompetenz und Akribie: Kirchenheizungen. Mikroprozessorgesteuerte Unterflur-Heizung schont Inventar und Budget

    Energy Technology Data Exchange (ETDEWEB)

    Ensink, H

    1994-05-01

    Church heating systems are heating systems for old building types (churches, festival halls in castles, assembly halls) which make special demands on planning and execution. This paper describes an underfloor church heating. In this connection the subjects space temperature, heat requirement calculation, heat generator, heat distribution, automatic control, heat build-up and cool-down ramp, time switch, ventilator stage and temperature selection are dealt with. (BWI)

  6. Sizewell: UK power demand

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    The Sizewell Inquiry was about whether the next power stations to be built in the UK should be nuclear or coal and, if nuclear, PWRs or AGRs. During the period of the Inquiry forecasts of demand for electricity were low. Now, however, it seems that the forecast demand is much increased. This uncertainty in demand and the wide regional variations are examined in some detail. Facts and figures on electricity sales (area by area) are presented. Also the minutes of supply lost per consumer per year. These show that security of supply is also a problem. It is also shown that the way electricity is used has changed. Whilst electricity generation has been changing to large-scale, centralised power stations the demand patterns may make smaller scale, quickly-constructed units more sensible. The questions considered at the Sizewell Inquiry may, indeed, no longer be the right ones. (UK)

  7. A demanding market

    International Nuclear Information System (INIS)

    Thomas, M.

    1997-01-01

    The article relates to the oil and natural gas market, and it gives a survey of proved reserves at the end of 1996 worldwide. The long term trend of increasing world energy demand has seen a major rise during 1996 when global consumption grew by 3%. But worldwide demand, excluding the Former Soviet Union, shows this figure increasing further to 3.7% for the whole of last year according to statistics. 3 figs

  8. Maximum power demand cost

    International Nuclear Information System (INIS)

    Biondi, L.

    1998-01-01

    The charging for a service is a supplier's remuneration for the expenses incurred in providing it. There are currently two charges for electricity: consumption and maximum demand. While no problem arises about the former, the issue is more complicated for the latter and the analysis in this article tends to show that the annual charge for maximum demand arbitrarily discriminates among consumer groups, to the disadvantage of some [it

  9. The Q(s,S) control policy for the joint replenishment problem extended to the case of correlation among item-demands

    DEFF Research Database (Denmark)

    Larsen, Christian

    2009-01-01

    We develop an algorithm to compute an optimal Q(s,S) policy for the joint replenishment problem when demands follow a compound correlated Poisson process. It is a non-trivial generalization of the work by Nielsen and Larsen [2005. An analytical study of the Q(s,S) policy applied to the joint...... replenishment problem. European Journal of Operational Research 163, 721-732]. We make some numerical analyses on two-item problems where we compare the optimal Q(s,S) policy to the optimal uncoordinated (s,S) policies. The results indicate that the more negative the correlation the less advantageous...

  10. The Control Mechanism of Procedure and the New Panorama of Demand Repetitive Installed by Law Resolution Incident 13.105/2015

    Directory of Open Access Journals (Sweden)

    Ana Luíza Zakur Ayres

    2016-10-01

    Full Text Available The study aims to address the legislative innovations inserted by Law 13.105/2015, specially in relation to the incident Demand Resolution Repetitive therefore be necessary to apply dynamically devices and equipped principles. Will be shown to the expansion and vertical integration competence of the Supreme Court,assigned topics such as weighting values with enticing features in day- to-day trials. Thus , it seeks to analyze the IRDR,from a global perspective, as it aims to define common legal interpretation repetitive individual actions, which should be adopted in all cases in which it arises the same question of law.

  11. Demand Response With Micro-CHP Systems

    NARCIS (Netherlands)

    Houwing, M.; Negenborn, R.R.; De Schutter, B.

    2011-01-01

    With the increasing application of distributed energy resources and novel information technologies in the electricity infrastructure, innovative possibilities to incorporate the demand side more actively in power system operation are enabled. A promising, controllable, residential distributed

  12. Coming to grips with challenging behaviour: a cluster randomised controlled trial on the effects of a new care programme for challenging behaviour on burnout, job satisfaction and job demands of care staff on dementia special care units.

    Science.gov (United States)

    Zwijsen, S A; Gerritsen, D L; Eefsting, J A; Smalbrugge, M; Hertogh, C M P M; Pot, A M

    2015-01-01

    Caring for people with dementia in dementia special care units is a demanding job. Challenging behaviour is one of the factors influencing the job satisfaction and burnout of care staff. A care programme for the challenging behaviour of nursing home residents with dementia might, next to diminishing the challenging behaviour of residents, improve job satisfaction and reduce the care staff's feelings of burnout. To determine the effects of a care programme for the challenging behaviour of nursing home residents with dementia on the burnout, job satisfaction and job demands of care staff. The care programme was implemented according to a stepped wedge design in which care units were randomly divided over five groups with different time points of starting with implementation. 17 Dutch dementia special care units. Care staff members of the 17 units. The care programme consists of an education package and of various structured assessment tools that guide professionals through the multidisciplinary detection, analysis, treatment and evaluation of treatment of challenging behaviour. Burnout, job satisfaction and job demands were measured before implementation, halfway through the implementation process and after all the care units had implemented the care programme. Burnout was measured with the Dutch version of the Maslach burnout inventory (UBOS-C, three subscales); job satisfaction and job demands were measured with subscales of the Leiden Quality of Work Questionnaire. Mixed model analyses were used to determine effects. Care staff could not be blinded for the intervention. Of the 1441 questionnaires, 645 were returned (response 45%, 318 control measurements, 327 intervention measurements) by 380 unique care staff members. Significant effects were found on job satisfaction (0.93, 95% CI 0.48-1.38). On the other outcomes, no significant changes in the scores were found. Positive effects of using the Grip on Challenging behaviour care programme were found on job

  13. Job control, job demands, social support at work and health among adolescent workers Controle, exigências, apoio social no trabalho e efeitos na saúde de trabalhadores adolescentes

    Directory of Open Access Journals (Sweden)

    Frida M Fischer

    2005-04-01

    Full Text Available OBJECTIVE: To evaluate physical and psychological dimensions of adolescent labor (such as job demands, job control, and social support in the work environment, and their relation to reported body pain, work injuries, sleep duration and daily working hours. METHODS: A total of 354 adolescents attending evening classes at a public school in São Paulo, Brazil, answered questionnaires regarding their living and working conditions (Karasek's Job Content Questionnaire, 1998, and their health status. Data collection took place in April and May 2001. Multiple logistic regression analysis was used to determine relations among variables. RESULTS: Psychological job demands were related to body pain (OR=3.3, higher risk of work injuries (OR=3.0 and reduced sleep duration in weekdays (Monday to Thursday (pOBJETIVO: Avaliar as dimensões físicas e psicológicas do trabalho de adolescentes (demanda de trabalho, controle no trabalho e apoio social e ambiental, relacionando-os a relatos de: dores no corpo, acidentes de trabalho, duração de sono e duração diária da jornada de trabalho. MÉTODOS: Participaram do estudo 354 estudantes do período noturno de escola pública no Município de São Paulo, entre abril e maio de 2001. Esses, responderam a questionário sobre condições de vida, trabalho (escalas Karasek de controle no trabalho e estado de saúde. Foram feitas análises de regressão logística múltipla a fim de determinar a relação entre variáveis. RESULTADOS: As exigências psicológicas mostraram-se associadas aos relatos de dores no corpo (OR=3,3, maiores riscos de ocorrência de acidentes de trabalho (OR=3,0 e redução da duração do sono durante os dias de semana (segunda a quinta-feira (p<0,01. Baixa autoridade de decisão (p=0,03 e maior segurança no emprego (p=0,02 estão relacionadas à maior duração da jornada diária de trabalho. CONCLUSÕES: Concluiu-se que não somente os estressores físicos, mas também os psicol

  14. Advertising media and cigarette demand.

    Science.gov (United States)

    Goel, Rajeev K

    2011-01-01

    Using state-level panel data for the USA spanning three decades, this research estimates the demand for cigarettes. The main contribution lies in studying the effects of cigarette advertising disaggregated across five qualitatively different groups. Results show cigarette demand to be near unit elastic, the income effects to be generally insignificant and border price effects and habit effects to be significant. Regarding advertising effects, aggregate cigarette advertising has a negative effect on smoking. Important differences across advertising media emerge when cigarette advertising is disaggregated. The effects of public entertainment and Internet cigarette advertising are stronger than those of other media. Anti-smoking messages accompanying print cigarette advertising seem relatively more effective. Implications for smoking control policy are discussed.

  15. UK Nuclear Workforce Demand

    International Nuclear Information System (INIS)

    Roberts, John

    2017-01-01

    UK Nuclear Sites: DECOMMISSIONING - 26 Magnox Reactors, 2 Fast Reactors; OPERATIONAL - 14 AGRs, 1 PWR; 9.6 GWe Total Capacity. Nuclear Workforce Demand • Total workforce demand is expected to grow from ~88,000 in 2017 to ~101,000 in 2021 • Average “inflow” is ~7,000 FTEs per annum • 22% of the workforce is female (28% in civil, 12% in defence) • 81% generic skills, 18% nuclear skills, 1% subject matter experts • 3300 trainees total in SLCs and Defence Enterprise (16% graduate trainees) • At peak demand on Civils Construction, over 4,000 workers will be required on each nuclear new build site • Manufacturing workforce is expected to rise from around 4,000 in 2014 to 8,500 at the peak of onsite activity in 2025

  16. Demand Modelling in Telecommunications

    Directory of Open Access Journals (Sweden)

    M. Chvalina

    2009-01-01

    Full Text Available This article analyses the existing possibilities for using Standard Statistical Methods and Artificial Intelligence Methods for a short-term forecast and simulation of demand in the field of telecommunications. The most widespread methods are based on Time Series Analysis. Nowadays, approaches based on Artificial Intelligence Methods, including Neural Networks, are booming. Separate approaches will be used in the study of Demand Modelling in Telecommunications, and the results of these models will be compared with actual guaranteed values. Then we will examine the quality of Neural Network models. 

  17. DemandStat

    International Nuclear Information System (INIS)

    2003-01-01

    DemandStat is an accurate and up-to-date international statistics database dedicated to energy demand, with an unrivaled level of details for powerful market analysis. It provides detailed consumption statistics (30 sectors) on all energies, detailed 2003 data and historical annual data since 1970, frequent data revision and update (2 updates options), 150 data sources gathered and expertized, all data on a single database Consistent and homogeneous statistics, in line with all major data providers (IEA, Eurostat, ADB, OLADE, etc), no ruptures in time-series with easy request building and data analysis and reactive support from data experts. (A.L.B.)

  18. Education on Demand

    DEFF Research Database (Denmark)

    Boysen, Lis; Hende, Merete

    2015-01-01

    Dette notat beskriver nogle af resultaterne fra programmet "Education on Demand' i projektet Det erhvervsrettede Uddannelseslaboratorium. Programmet har haft fokus på udfordringer og forandringsbehov i uddannelsesinstitutioner og -systemet. Herunder har det beskæftiget sig særligt med de to temat......Dette notat beskriver nogle af resultaterne fra programmet "Education on Demand' i projektet Det erhvervsrettede Uddannelseslaboratorium. Programmet har haft fokus på udfordringer og forandringsbehov i uddannelsesinstitutioner og -systemet. Herunder har det beskæftiget sig særligt med de...

  19. Causality in demand

    DEFF Research Database (Denmark)

    Nielsen, Max; Jensen, Frank; Setälä, Jari

    2011-01-01

    to fish demand. On the German market for farmed trout and substitutes, it is found that supply sources, i.e. aquaculture and fishery, are not the only determinant of causality. Storing, tightness of management and aggregation level of integrated markets might also be important. The methodological...

  20. Oil supply and demand

    Energy Technology Data Exchange (ETDEWEB)

    Babusiaux, D

    2004-07-01

    Following the military intervention in Iraq, it is taking longer than expected for Iraqi exports to make a comeback on the market. Demand is sustained by economic growth in China and in the United States. OPEC is modulating production to prevent inventory build-up. Prices have stayed high despite increased production by non-OPEC countries, especially Russia. (author)

  1. Oil supply and demand

    Energy Technology Data Exchange (ETDEWEB)

    Rech, O

    2006-07-01

    The year 2004 saw a change in the oil market paradigm that was confirmed in 2005. Despite a calmer geopolitical context, prices continued to rise vigorously. Driven by world demand, they remain high as a result of the saturation of production and refining capacity. The market is still seeking its new equilibrium. (author)

  2. Oil supply and demand

    International Nuclear Information System (INIS)

    Rech, O.

    2006-01-01

    The year 2004 saw a change in the oil market paradigm that was confirmed in 2005. Despite a calmer geopolitical context, prices continued to rise vigorously. Driven by world demand, they remain high as a result of the saturation of production and refining capacity. The market is still seeking its new equilibrium. (author)

  3. The demand for euros

    NARCIS (Netherlands)

    Arnold, I.J.M.; Roelands, S.

    2010-01-01

    This paper investigates the demand for euros using panel data for 10 euro area countries covering the period from 1999 to 2008. Monetary aggregates are constructed to ensure that money is a national concept by excluding deposits owned by non-residents and including external deposits owned by

  4. Oil supply and demand

    International Nuclear Information System (INIS)

    Babusiaux, D.

    2004-01-01

    Following the military intervention in Iraq, it is taking longer than expected for Iraqi exports to make a comeback on the market. Demand is sustained by economic growth in China and in the United States. OPEC is modulating production to prevent inventory build-up. Prices have stayed high despite increased production by non-OPEC countries, especially Russia. (author)

  5. Oil supply and demand

    International Nuclear Information System (INIS)

    Rech, O.

    2004-01-01

    World oil demand, driven by economic development in China, posted the highest growth rate in 20 years. In a context of geopolitical uncertainty, prices are soaring, encouraged by low inventory and the low availability of residual production capacity. Will 2004 bring a change in the oil market paradigm? (author)

  6. Textbook Factor Demand Curves.

    Science.gov (United States)

    Davis, Joe C.

    1994-01-01

    Maintains that teachers and textbook graphics follow the same basic pattern in illustrating changes in demand curves when product prices increase. Asserts that the use of computer graphics will enable teachers to be more precise in their graphic presentation of price elasticity. (CFR)

  7. Oil supply and demand

    Energy Technology Data Exchange (ETDEWEB)

    Rech, O

    2004-07-01

    World oil demand, driven by economic development in China, posted the highest growth rate in 20 years. In a context of geopolitical uncertainty, prices are soaring, encouraged by low inventory and the low availability of residual production capacity. Will 2004 bring a change in the oil market paradigm? (author)

  8. Electricity demand in Tunisia

    International Nuclear Information System (INIS)

    Gam, Imen; Ben Rejeb, Jaleleddine

    2012-01-01

    This paper examines the global electricity demand in Tunisia as a function of gross domestic product in constant price, the degree of urbanization, the average annual temperature, and the real electricity price per Kwh. This demand will be examined employing annual data over a period spanning almost thirty one years from 1976 to 2006. A long run relationship between the variables under consideration is determined using the Vector Autoregressive Regression. The empirical results suggest that the electricity demand in Tunisia is sensitive to its past value, any changes in gross domestic product and electricity price. The electricity price effects have a negative impact on long-run electricity consumption. However, the gross domestic product and the past value of electricity consumption have a positive effect. Moreover, the causality test reveals a unidirectional relationship between price and electricity consumption. Our empirical findings are effective to policy makers to maintain the electricity consumption in Tunisia by using the appropriate strategy. - Highlights: ► This paper examined the electricity demand in Tunisia in the long-run. ► The empirical analysis revealed that in the long-run the electricity demand is affected by changes in its past value, GDP in constant price and real electricity price. ► There is a unidirectional relationship between price and electricity consumption, that is to say, that the electricity price causes the consumption. ► Those results suggest that a pricing policy can be an effective instrument to rationalize the electricity consumption in Tunisia in the long-run.

  9. World oil supply and demand'

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    Apart from a collapse of oil and gas consumption in the CIS, a strong increase in demand in the newly industrialized countries and an upward trend in the OECD countries are observed. Non-Opec supply continued to grow, with a production decline in Usa and Russia but a record production level in the North Sea and a remarkable revival in South America (Colombia, Argentina) and Africa (Congo, Angola). In Opec countries, the trend goes from supply control to development of production capacity. Situations in Saudi Arabia, Iran and Iraq are detailed

  10. Aggregated Demand Modelling Including Distributed Generation, Storage and Demand Response

    OpenAIRE

    Marzooghi, Hesamoddin; Hill, David J.; Verbic, Gregor

    2014-01-01

    It is anticipated that penetration of renewable energy sources (RESs) in power systems will increase further in the next decades mainly due to environmental issues. In the long term of several decades, which we refer to in terms of the future grid (FG), balancing between supply and demand will become dependent on demand actions including demand response (DR) and energy storage. So far, FG feasibility studies have not considered these new demand-side developments for modelling future demand. I...

  11. Sulphur demand growing. [Alberta

    Energy Technology Data Exchange (ETDEWEB)

    1975-01-20

    Sulfur markets look better going into 1975 than they have for several years, as North American demand growth is being filled largely by elemental sulfur producers and overseas. Demand is rising as fast as the capacity of Canadian transportation and handling facilities. It will take a long time to make much of a dent in the total Alberta stockpile of 14 million long tons at the end of 1974, with involuntary production from sour gas plants exceeding sales volume since 1972. However, there is some encouragement in the approaching peakout of production combined with a substantial increase in price since the low point of the cycle at the beginning of 1973, and a predicted rise of at least 20% in domestic (North American) sales this year over 1974.

  12. Ontario demand response scenarios

    International Nuclear Information System (INIS)

    Rowlands, I.H.

    2005-09-01

    Strategies for demand management in Ontario were examined via 2 scenarios for a commercial/institutional building with a normal summertime peak load of 300 kW between 14:00 and 18:00 during a period of high electricity demand and high electricity prices. The first scenario involved the deployment of a 150 kW on-site generator fuelled by either diesel or natural gas. The second scenario involved curtailing load by 60 kW during the same periods. Costs and benefits of both scenarios were evaluated for 3 groups: consumers, system operators and society. Benefits included electricity cost savings, deferred transmission capacity development, lower system prices for electricity, as well as environmental changes, economic development, and a greater sense of corporate social responsibility. It was noted that while significant benefits were observed for all 3 groups, they were not substantial enough to encourage action, as the savings arising from deferred generation capacity development do not accrue to individual players. The largest potential benefit was identified as lower prices, spread across all users of electricity in Ontario. It was recommended that representative bodies cooperate so that the system-wide benefits can be reaped. It was noted that if 10 municipal utilities were able to have 250 commercial or institutional customers engaged in distributed response, then a total peak demand reduction of 375 MW could be achieved, representing more than 25 per cent of Ontario's target for energy conservation. It was concluded that demand response often involves the investment of capital and new on-site procedures, which may affect reactions to various incentives. 78 refs., 10 tabs., 5 figs

  13. Household electricity demand profiles

    DEFF Research Database (Denmark)

    Marszal, Anna Joanna; Heiselberg, Per Kvols; Larsen, Olena Kalyanova

    2016-01-01

    Highlights •A 1-min resolution household electricity load model is presented. •Model adapts a bottom-up approach with single appliance as the main building block. •Load profiles are used to analyse the flexibility potential of household appliances. •Load profiles can be applied in other domains, .......g. building energy simulations. •The demand level of houses with different number of occupants is well captured....

  14. Energy demand patterns

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, L; Schipper, L; Meyers, S; Sathaye, J; Hara, Y

    1984-05-01

    This report brings together three papers on energy demand presented at the Energy Research Priorities Seminar held in Ottawa on 8-10 August 1983. The first paper suggests a framework in which energy demand studies may be organized if they are to be useful in policy-making. Disaggregation and the analysis of the chain of energy transformations are possible paths toward more stable and reliable parameters. The second paper points to another factor that leads to instability in sectoral parameters, namely a changeover from one technology to another; insofar as technologies producing a product (or service) vary in their energy intensity, a technological shift will also change the energy intensity of the product. Rapid technological change is characteristic of some sectors in developing countries, and may well account for the high aggregate GDP-elasticities of energy consumption observed. The third paper begins with estimates of these elasticities, which were greater than one for all the member countries of the Asian Development Bank in 1961-78. The high elasticities, together with extreme oil dependence, made them vulnerable to the drastic rise in the oil price after 1973. The author distinguishes three diverging patterns of national experience. The oil-surplus countries naturally gained from the rise in the oil price. Among oil-deficit countries, the newly industrialized countries expanded their exports so rapidly that the oil crisis no longer worried them. For the rest, balance of payments adjustments became a prime concern of policy. Whether they dealt with the oil bill by borrowing, by import substitution, or by demand restraint, the impact of energy on their growth was unmistakable. The paper also shows why energy-demand studies, and energy studies in general, deserve to be taken seriously. 16 refs., 4 figs., 18 tabs.

  15. Migration and Tourism Demand

    Directory of Open Access Journals (Sweden)

    Nuno Carlos LEITÃO

    2012-02-01

    Full Text Available This study considers the relationship between immigration and Portuguese tourism demand for the period 1995-2008, using a dynamic panel data approach. The findings indicate that Portuguese tourism increased significantly during the period in accordance with the values expected for a developed country. The regression results show that income, shock of immigration, population, and geographical distance between Portugal and countries of origin are the main determinants of Portuguese tourism.

  16. Demand scenarios, worldwide

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, A [Massachusetts Inst. of Technology, Center for Technology, Policy and Industrial Development and the MIT Joint Program on the Science and Policy of Global Change, Cambridge, MA (United States)

    1996-11-01

    Existing methods are inadequate for developing aggregate (regional and global) and long-term (several decades) passenger transport demand scenarios, since they are mainly based on simple extensions of current patterns rather than causal relationships that account for the competition among transport modes (aircraft, automobiles, buses and trains) to provide transport services. The demand scenario presented in this paper is based on two empirically proven invariances of human behavior. First, transport accounts for 10 to 15 percent of household total expenditures for those owning an automobile, and around 5 percent for non-motorized households on average (travel money budget). Second, the mean time spent traveling is approximately one hour per capita per day (travel time budget). These two budgets constraints determine the dynamics of the scenario: rising income increases per capita expenditure on travel which, in turn, increase demand for mobility. Limited travel time constraints travelers to shift to faster transport systems. The scenario is initiated with the first integrated historical data set on traffic volume in 11 world regions and the globe from 1960 to 1990 for all major modes of motorized transport. World average per capita traffic volume, which was 1,800 kilometers in 1960 and 4,2090 in 1990, is estimated to rise to 7,900 kilometers in 2020 - given a modest average increase in Gross World Product of 1.9% per year. Higher economic growth rates in Asian regions result in an increase in regional per capita traffic volume up to a factor of 5.3 from 1990 levels. Modal splits continue shifting to more flexible and faster modes of transport. At one point, passenger cars can no longer satisfy the increasing demand for speed (i.e. rising mobility within a fixed time budget). In North America it is estimated that the absolute traffic volume of automobiles will gradually decline starting in the 2010s. (author) 13 figs., 6 tabs., 35 refs.

  17. A comparison between the order and the volume fill rates for a base-stock inventory control system under a compound renewal demand process

    DEFF Research Database (Denmark)

    Larsen, Christian; Thorstenson, Anders

    The order fill rate is less commonly used than the volume fill rate (most often just denoted fill rate) as a performance measure for inventory control systems. However, in settings where the focus is on filling customer orders rather than total quantities, the order fill rate should be the prefer......The order fill rate is less commonly used than the volume fill rate (most often just denoted fill rate) as a performance measure for inventory control systems. However, in settings where the focus is on filling customer orders rather than total quantities, the order fill rate should...

  18. Supply and demand perspectives

    International Nuclear Information System (INIS)

    Trienekens, Pieter

    1999-01-01

    The outlook for the European gas market is one of steady growth. This growth will manifest itself in all regions and in all sectors of the market, but most strongly in the power generating sector. To meet future demand, it is necessary to bring gas to Western Europe from remote sources in Russia, North Africa and Norway. These new gas supplies require heavy investments in production and transportation, which can only be undertaken on the basis of long-term take-or-pay contracts. Famous examples of such contracts are the development of the Troll field, the Yamal-Europe pipeline connection, and the bringing on stream of Nigerian LNG for Europe. Tensions are likely to arise between the nature of these long-term gas contracts and the dynamic nature of demand in the gas market, and more specifically in the main growth market, the power sector. The presentation further elaborates on the tensions underlying supply and demand in the years to come

  19. Demand response in a market environment

    OpenAIRE

    Larsen, Emil Mahler; Pinson, Pierre; Ding, Yi; Østergaard, Jacob

    2016-01-01

    This thesis addresses the design, deployment and benefits of demand response in a market environment. Demand response is consumption that can be controlled by an external stimulus in the power system. Flexible consumption is a useful tool for absorbing volatile power from renewable sources like wind power and photovoltaics, and dealing with decentralised activity like electric vehicle charging. Without flexible consumption or other new technologies like storage, there will be several occasion...

  20. An experimental study of the job demand-control model with measures of heart rate variability and salivary alpha-amylase: Evidence of increased stress responses to increased break autonomy.

    Science.gov (United States)

    O'Donnell, Emma; Landolt, Kathleen; Hazi, Agnes; Dragano, Nico; Wright, Bradley J

    2015-01-01

    We assessed in an experimental design whether the stress response towards a work task was moderated by the autonomy to choose a break during the assigned time to complete the task. This setting is defined in accordance with the theoretical framework of the job-demand-control (JDC) model of work related stress. The findings from naturalistic investigations of a stress-buffering effect of autonomy (or 'buffer hypothesis') are equivocal and the experimental evidence is limited, especially with relation to physiological indices of stress. Our objective was to investigate if increased autonomy in a particular domain (break time control) was related with adaptive physiology using objective physiological markers of stress; heart rate variability (HRV) and salivary alpha amylase (sAA). We used a within-subject design and the 60 female participants were randomly assigned to an autonomy (free timing of break) and standard conditions (fixed timing of break) of a word processing task in a simulated office environment in a random order. Participants reported increased perceptions of autonomy, no difference in demand and performed worse in the task in the break-time autonomy versus the standard condition. The results revealed support for the manipulation of increased autonomy, but in the opposing direction. Increased autonomy was related with dysregulated physiological reactivity, synonymous with typical increased stress responses. Potentially, our findings may indicate that autonomy is not necessary a resource but could become an additional stressor when it adds additional complexity while the amount of work (demands) remains unchanged. Further, our findings underscore the need to collect objective physiological evidence of stress to supplement self-reported information. Self-report biases may partially explain the inconsistent findings with the buffer hypothesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. A comparison between the order and the volume fill rate for a base-stock inventory control system under a compound renewal demand process

    DEFF Research Database (Denmark)

    Larsen, Christian; Thorstenson, Anders

    2008-01-01

    The order fill rate (OFR) is sometimes suggested as an alternative to the volume fill rate (VFR) (most often just denoted fill rate) as a performance measure for inventory control systems. We consider a continuous review, base-stock policy, where replenishment orders have a constant lead time...

  2. Strategies for Demand Response in Commercial Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Watson, David S.; Kiliccote, Sila; Motegi, Naoya; Piette, Mary Ann

    2006-06-20

    This paper describes strategies that can be used in commercial buildings to temporarily reduce electric load in response to electric grid emergencies in which supplies are limited or in response to high prices that would be incurred if these strategies were not employed. The demand response strategies discussed herein are based on the results of three years of automated demand response field tests in which 28 commercial facilities with an occupied area totaling over 11 million ft{sup 2} were tested. Although the demand response events in the field tests were initiated remotely and performed automatically, the strategies used could also be initiated by on-site building operators and performed manually, if desired. While energy efficiency measures can be used during normal building operations, demand response measures are transient; they are employed to produce a temporary reduction in demand. Demand response strategies achieve reductions in electric demand by temporarily reducing the level of service in facilities. Heating ventilating and air conditioning (HVAC) and lighting are the systems most commonly adjusted for demand response in commercial buildings. The goal of demand response strategies is to meet the electric shed savings targets while minimizing any negative impacts on the occupants of the buildings or the processes that they perform. Occupant complaints were minimal in the field tests. In some cases, ''reductions'' in service level actually improved occupant comfort or productivity. In other cases, permanent improvements in efficiency were discovered through the planning and implementation of ''temporary'' demand response strategies. The DR strategies that are available to a given facility are based on factors such as the type of HVAC, lighting and energy management and control systems (EMCS) installed at the site.

  3. Directive and nondirective social support in the workplace – is this social support distinction important for subjective health complaints, job satisfaction, and perception of job demands and job control?

    Science.gov (United States)

    Johnsen, Tone Langjordet; Eriksen, Hege Randi; Indahl, Aage; Tveito, Torill Helene

    2017-01-01

    Aims: Social support is associated with well-being and positive health outcomes. However, positive outcomes of social support might be more dependent on the way support is provided than the amount of support received. A distinction can be made between directive social support, where the provider resumes responsibility, and nondirective social support, where the receiver has the control. This study examined the relationship between directive and nondirective social support, and subjective health complaints, job satisfaction and perception of job demands and job control. Methods: A survey was conducted among 957 Norwegian employees, working in 114 private kindergartens (mean age 40.7 years, SD = 10.5, 92.8% female), as part of a randomized controlled trial. This study used only baseline data. A factor analysis of the Norwegian version of the Social Support Inventory was conducted, identifying two factors: nondirective and directive social support. Hierarchical regression analyses were then performed. Results: Nondirective social support was related to fewer musculoskeletal and pseudoneurological complaints, higher job satisfaction, and the perception of lower job demands and higher job control. Directive social support had the opposite relationship, but was not statistically significant for pseudoneurological complaints. Conclusions: It appears that for social support to be positively related with job characteristics and subjective health complaints, it has to be nondirective. Directive social support was not only without any association, but had a significant negative relationship with several of the variables. Nondirective social support may be an important factor to consider when aiming to improve the psychosocial work environment. Trial registration: Clinicaltrials.gov: NCT02396797. Registered 23 March 2015. PMID:28820017

  4. Meeting increased demand.

    Science.gov (United States)

    Blair, Andrew

    2004-07-01

    New Zealand is a little country with a little economy but with a population that's rapidly aging. New Zealand's population is only 4.3 million people. It's GDP is only $US58.6 billion (2002). New Zealand's expenditure on health as a percentage of GDP is not out of line with that of other countries. As a nation we have been increasing expenditure on health over recent years. In 1990 we spent 7% of GDP on health. In 1995 that increased to 7.65% and is now 8.3%. However, in per capita terms our expenditure on health does not compare so well with like countries. The size of New Zealand's economy is restricting what our country spends on health. Health is already the second highest demand on the New Zealand tax dollar. The tolerance of New Zealanders would be challenged if a Government attempted to increase taxes further to meet the growing demands for expenditure on health, but at the same time the population's expectations are increasing. This is the challenging situation we face today. What lies ahead? Like all industrialized countries New Zealand is facing an aging population. The population below age 40 is decreasing, but it is increasing significantly over that age. 16% of the population is currently aged over 60. By 2051 this proportion will almost double to just over 31%. Coupled with the aging population is increased awareness and expectations, as access to options for treatment and technology becomes readily accessible to the population through such media as the internet. The extent of the impact of the aging population can be clearly represented by focusing on one specialty such as orthopaedics. The New Zealand Orthopaecic Association undertook a study in July 2003 which concluded (among other things) that as a result of the projected aging of the population, over the next 50 years: Musculo-skeletal operations will increase by over 30%. The number of hip replacements will nearly double. The incidence of osteoporosis will increase by a massive 201%. The number

  5. Psychopathology and tobacco demand.

    Science.gov (United States)

    Farris, Samantha G; Aston, Elizabeth R; Zvolensky, Michael J; Abrantes, Ana M; Metrik, Jane

    2017-08-01

    Behavioral economic measurement of the relative value of tobacco (Cigarette Purchase Task; CPT) is used to examine individual differences in motivation for tobacco under certain contexts. Smokers with psychopathology, relative to those without, may demonstrate stronger demand for tobacco following a period of smoking deprivation, which could account for disparate rates of smoking and cessation among this subgroup. Participants (n=111) were community-recruited adult daily smokers who completed the CPT after a deprivation period of approximately 60min. Presence of psychopathology was assessed via clinical interview; 40.5% (n=45) of the sample met criteria for past-year psychological diagnosis. Specifically, 31.5% (n=35) had an emotional disorder (anxiety/depressive disorder), 17.1% (n=19) had a substance use disorder, and 19.1% of the sample had more than one disorder. Smokers with any psychopathology showed significantly higher intensity (demand at unrestricted cost; $0) and O max (peak expenditure for a drug) relative to smokers with no psychopathology. Intensity was significantly higher among smokers with an emotional disorder compared to those without. Smokers with a substance use disorder showed significantly higher intensity and O max , and lower elasticity, reflecting greater insensitivity to price increases. Having≥2 disorders was associated with higher intensity relative to having 1 or no disorders. Findings suggest that presence of psychopathology may be associated with greater and more persistent motivation to smoke. Future work is needed to explore the mechanism linking psychopathology to tobacco demand. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Ethane supply and demand

    International Nuclear Information System (INIS)

    Jamerson, J.B.

    1993-01-01

    Estimates are given for ethane production, chiefly from the Gulf Coast area. Increase in interregional transfers are predicted. Comparisons from 1992 through 1995 are made. The author concludes the following: ethane will be supply limited over the decade of the 90's; values will be over competing feedstocks; minimum practical demands will be close to available supply; regional relationships will reflect pipeline tariffs; purity ethane/EP spreads may narrow with new Mt. Belvieu fractionation capacity; new domestic supplies will back out imports; and Ethane's share of ethylene production may drop over the period

  7. Road infrastructure and demand induction

    DEFF Research Database (Denmark)

    Nielsen, Thomas Alexander Sick; Hovgesen, Henrik Harder; Lahrmann, Harry

    2006-01-01

    a long screenline is used to measure the development in aggregate demand in selected corridors. The paper analyses demand induction by establishing time series of aggregate demand that is compared with the national traffic index. Significant trend breaks in the association between aggregate demand...... in the corridors and the national index, following the opening of motorways or bridges, indicates demand induction by infrastructure expansion in a number of instances. Lack of significant trend breaks following opening year is found in peripheral areas where major population centres are missing. This indicates...... the necessity of some latent demand within suitable travel range for new infrastructure elements to produce significant amounts of induced demand. Estimates of demand induction as a percentage of the realised demand five years after opening are between 10% and 67% for new motorway sections depending...

  8. Demand response in energy markets

    International Nuclear Information System (INIS)

    Skytte, K.; Birk Mortensen, J.

    2004-11-01

    Improving the ability of energy demand to respond to wholesale prices during critical periods of the spot market can reduce the total costs of reliably meeting demand, and the level and volatility of the prices. This fact has lead to a growing interest in the short-run demand response. There has especially been a growing interest in the electricity market where peak-load periods with high spot prices and occasional local blackouts have recently been seen. Market concentration at the supply side can result in even higher peak-load prices. Demand response by shifting demand from peak to base-load periods can counteract the market power in the peak-load. However, demand response has so far been modest since the current short-term price elasticity seems to be small. This is also the case for related markets, for example, green certificates where the demand is determined as a percentage of the power demand, or for heat and natural gas markets. This raises a number of interesting research issues: 1) Demand response in different energy markets, 2) Estimation of price elasticity and flexibility, 3) Stimulation of demand response, 4) Regulation, policy and modelling aspects, 5) Demand response and market power at the supply side, 6) Energy security of supply, 7) Demand response in forward, spot, ancillary service, balance and capacity markets, 8) Demand response in deviated markets, e.g., emission, futures, and green certificate markets, 9) Value of increased demand response, 10) Flexible households. (BA)

  9. Demandas do trabalho e controle: implicações em unidades de terapia intensiva pediátrica e neonatal Demandas y control del trabajo: implicaciones en las unidades de tratamiento intensivo pediatrico y neonatal Demands and control of work: implications in pediatric and neonatal intensive care units

    Directory of Open Access Journals (Sweden)

    Monalisa de Cássia Fogaça

    2010-08-01

    Full Text Available Comparar a demanda e o controle sobre trabalho de médicos e enfermeiros que trabalham em unidades de tratamento intensivo pediátrica e neonatal. Estudo transversal com 37 médicos e 20 enfermeiros. Utilizou-se o Job Content Questionnarie. Médicos da UTI Neonatal diferem em suporte social recebido do supervisor (p=0,01 em relação aos da UTI Pediátrica. Enfermeiros da UTI Neonatal apresentam insegurança no trabalho (p=0,05. Médicos e enfermeiros da UTI Pediátrica diferem em controle sobre o trabalho; demanda psicológica do trabalho; esforço físico e suporte do supervisor (pComparación de la demanda y control sobre el trabajo de los médicos y enfermeras que trabajan en las unidades de tratamiento intensivo pediátrico y neonatal. Estudio transversal con 37 médicos y 20 enfermeras. Se utilizó el Job Content Questionnarie. Los médicos de la UCI Neonatal difieren en el apoyo social recibido desde el supervisor (p= 0,01 en comparacion com la UCI Pediátrica. Enfermeras de la UCI Neonatal actualmente la inseguridad en el empleo (p = 0,05. Los médicos y enfermeras de la UCI Pediátrica difieren em el control sobre el trabajo, las exigencias psicológicas del trabajo, esfuerzo físico y el apoyo del supervisor (pTo compare the demand and control over work of physicians and nurses working in pediatric and neonatal critical care units. Cross-sectional study with 37 doctors and 20 nurses. We used the Job Content Questionnarie. Physicians from the ICU Neonatal differ in social support received from the supervisor (p= 0.01 compared to the ICU Pediatric. ICU nurses of the Neonatal present job insecurity (p= 0.05. Physicians and nurses from the ICU Pediatric differ in control over the work, psychological demands of work, physical effort and support of the supervisor (p <0.05. Physicians and nurses from the ICU Neonatal show statistical differences in control over the work, physical effort and support of the supervisor (p<0.05. The work

  10. Demand for electrical energy

    International Nuclear Information System (INIS)

    Bergougnoux, J.; Fouquet, D.

    1983-01-01

    The different utilizations of electric energy are reviewed in the residential and tertiary sectors, in the industry. The competitive position of electricity in regard to other fuels has been strengthned by the sudden rise in the price of oil in 1973-1974 and 1979-1980. The evolution of electricity prices depended on the steps taken to adjust the electricity generation system. The substitution of electricity applications for hydro-carbons is an essential point of energy policy. The adjustment at all times, at least cost and most reliability, of the supply of electricity to the demand for it is a major problem in the design and operation of electric systems. National demand for power at a given moment is extremely diversified. Electricity consumption presents daily and seasonal variations, and variations according to the different sectors. Forecasting power requirements is for any decision on operation or investment relating to an electrical system. Load management is desirable (prices according to the customers, optional tariffs for ''peak-day withdrawal''). To conclude, prospects for increased electricity consumption are discussed [fr

  11. Ad libitum or demand/semi-demand feeding versus scheduled interval feeding for preterm infants.

    Science.gov (United States)

    McCormick, Felicia M; Tosh, Karen; McGuire, William

    2010-02-17

    Scheduled interval feeding of prescribed enteral volumes is current standard practice for preterm infants. However, feeding preterm infants in response to their hunger and satiation cues (ad libitum or demand/semi demand) rather than at scheduled intervals might help in the establishment of independent oral feeding, increase nutrient intake and growth rates, and allow earlier hospital discharge. To assess the effect of a policy of feeding preterm infants on an ad libitum or demand/semi-demand basis versus feeding prescribed volumes at scheduled intervals on growth rates and the time to hospital discharge. We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2009), MEDLINE (1966 to Oct 2009), EMBASE (1980 to Oct 2009), CINAHL (1982 to Oct 2009), conference proceedings, and previous reviews. Randomised or quasi-randomised controlled trials (including cluster randomised trials) that compared a policy of feeding preterm infants on an ad libitum or demand/semi-demand basis versus feeding at scheduled intervals. We used the standard methods of the Cochrane Neonatal Review Group with separate evaluation of trial quality and data extraction by two review authors. We found eight randomised controlled trials that compared ad libitum or demand/semi-demand regimens with scheduled interval regimes in preterm infants in the transition phase from intragastric tube to oral feeding. The trials were generally small and of variable methodological quality. The duration of the intervention and the duration of data collection and follow-up in most of the trials was not likely to have allowed detection of measurable effects on growth. Three trials reported that feeding preterm infants using an ad libitum or demand/semi-demand feeding regimen allowed earlier discharge from hospital (by about two to four days) but other trials did not confirm this

  12. Market design for rapid demand response

    DEFF Research Database (Denmark)

    Nielsen, Kurt; Tamirat, Tseganesh Wubale

    We suggest a market design for rapid demand response in electricity markets. The solution consists of remotely controlled switches, meters, forecasting models as well as a flexible auction market to set prices and select endusers job by job. The auction market motivates truth-telling and makes...... it simple to involve the endusers in advance and to activate demand response immediately. The collective solution is analyzed and economic simulations are conducted for the case of Kenya. Kenya has been su ering from unreliable electricity supply for many years and companies and households have learned...... to adjust by investments in backup generators. We focus on turning the many private backup generators into a demand response system. The economic simulation focuses on possible distortion introduced by various ways of splitting the generated surplus from the demand response system. An auction run instantly...

  13. Demand Response Valuation Frameworks Paper

    Energy Technology Data Exchange (ETDEWEB)

    Heffner, Grayson

    2009-02-01

    While there is general agreement that demand response (DR) is a valued component in a utility resource plan, there is a lack of consensus regarding how to value DR. Establishing the value of DR is a prerequisite to determining how much and what types of DR should be implemented, to which customers DR should be targeted, and a key determinant that drives the development of economically viable DR consumer technology. Most approaches for quantifying the value of DR focus on changes in utility system revenue requirements based on resource plans with and without DR. This ''utility centric'' approach does not assign any value to DR impacts that lower energy and capacity prices, improve reliability, lower system and network operating costs, produce better air quality, and provide improved customer choice and control. Proper valuation of these benefits requires a different basis for monetization. The review concludes that no single methodology today adequately captures the wide range of benefits and value potentially attributed to DR. To provide a more comprehensive valuation approach, current methods such as the Standard Practice Method (SPM) will most likely have to be supplemented with one or more alternative benefit-valuation approaches. This report provides an updated perspective on the DR valuation framework. It includes an introduction and four chapters that address the key elements of demand response valuation, a comprehensive literature review, and specific research recommendations.

  14. Animating the Ethical Demand

    DEFF Research Database (Denmark)

    Vistisen, Peter; Jensen, Thessa; Poulsen, Søren Bolvig

    2015-01-01

    This paper addresses the challenge of attaining ethical user stances during the design process of products and services and proposes animation-based sketching as a design method, which supports elaborating and examining different ethical stances towards the user. The discussion is qualified...... by an empirical study of Responsible Research and Innovation (RRI) in a Triple Helix constellation. Using a three-week long innovation workshop, U- CrAc, involving 16 Danish companies and organisations and 142 students as empirical data, we discuss how animation-based sketching can explore not yet existing user...... dispositions, as well as create an incentive for ethical conduct in development and innovation processes. The ethical fulcrum evolves around Løgstrup’s Ethical Demand and his notion of spontaneous life manifestations. From this, three ethical stances are developed; apathy, sympathy and empathy. By exploring...

  15. Rewarding yet demanding

    DEFF Research Database (Denmark)

    Bjørkedal, S T B; Torsting, A M B; Møller, T

    2016-01-01

    in a logbook. The Canadian Occupational Performance Measure was used to initiate and guide the intervention and the Canadian Model of Client-Centred Enablement for the client-therapist relationship. RESULTS: Participants described the intervention, which presupposed a certain level of patient readiness...... design comprising an eight-week client-centred occupational therapy intervention with semi-structured interviews with five of the six clients out of 10 who completed the intervention. Braun and Clark's thematic analysis was applied to the transcripts. Adherence rate and dropouts were recorded......, as demanding. Participants valued engaging in real-life occupations while anchoring new strategies but also the occupational therapist's role in dealing with failure. Participants felt the intervention assisted in their recovery process and enabled them to engage in meaningful occupations. CONCLUSION...

  16. PROOF on Demand

    International Nuclear Information System (INIS)

    Malzacher, Peter; Manafov, Anar

    2010-01-01

    PROOF on Demand (PoD) is a set of utilities, which allows starting a PROOF cluster at user request, on any resource management system. It provides a plug-in based system, which allows to use different job submission frontends, such as LSF or gLite WMS. Main components of PoD are the PROOFAgent and the PAConsole. PROOFAgent provides the communication layer between the PROOF master on the local machine and the PROOF workers on the remote resources, possibly behind a firewall. PAConsole provides a user-friendly GUI, which is used to setup, manage, and shutdown the dynamic PROOF cluster. Installation is simple and doesn't require administrator privileges, and all the processes run in user space. PoD gives users, who don't have a centrally-administrated static PROOF cluster at their institute, the possibility to enjoy the full power of interactive analysis with PROOF.

  17. [Cigarette taxes and demand in Colombia].

    Science.gov (United States)

    Maldonado, Norman; Llorente, Blanca; Deaza, Javier

    2016-10-01

    Estimate price and income elasticities of aggregate demand for cigarettes in Colombia, by controlling for structural market changes since the late 1990s, to identify policy opportunities for taxes that could improve public health and increase tax revenues. Measurement of aggregate demand for cigarettes using gross income reported on value-added tax returns submitted to Colombia's National Tax and Customs Office (DIAN is the acronym in Spanish) by the tobacco product manufacturing industry, subtracting exports. A quarterly time series was obtained for the period 1994-2014. The econometric estimation using two-stage least squares controls for price endogeneity and uses a set of dummy variables to control for structural changes in the market and in its regulation. Demand is, from a statistical standpoint, sensitive to price and to income. Price elasticity of demand is -0.78 and income elasticity is 0.61. Inelastic demand implies that it is possible, through cigarette excise taxes, to meet public health targets and increase revenues simultaneously. The results also suggest that the considerable increase in household income in Colombia in the first decade of the 21st century increased purchasing power, which, lacking an accompanying tax increase, promoted cigarette consumption, with negative effects on public health, and wasted an opportunity to increase tax revenues.

  18. Residential electricity demand in Singapore

    International Nuclear Information System (INIS)

    Ang, B.W.; Goh, T.N.; Liu, X.Q.

    1992-01-01

    Residential electricity consumption in Singapore increased at a rate of 8.8% per year between 1972 and 1990. Estimates of the long-run income and price elasticities are 1.0 and -0.35, respectively. The energy-conservation campaigns that have been launched are found to have marginal effects on consumption. A statistical analysis shows that the consumption is sensitive to small changes in climatic variables, particularly the temperature, which is closely linked to the growing diffusion of electric appliances for environmental controls. There has been a temporal increase in the ownership levels of appliances associated with increasing household incomes. However, other factors were involved since the ownership levels would also increase over time after the elimination of the income effect. A large part of the future growth in electricity demand will arise from the growing need for air-conditioning, which will lead to increasingly large seasonal variations in electricity use. (author)

  19. Demand response in a market environment

    DEFF Research Database (Denmark)

    Larsen, Emil Mahler

    This thesis addresses the design, deployment and benefits of demand response in a market environment. Demand response is consumption that can be controlled by an external stimulus in the power system. Flexible consumption is a useful tool for absorbing volatile power from renewable sources like...... this simulation, real power system data from the Danish island of Bornholm is introduced and methods to quantify an aggregated load is developed. These methods can be used for real-time operation and to support investment decisions. More specifically, they can be used to forecast the response to electricity...... pricing and to classify different types of customers. The proposed models are then embedded into new fiveminute electricity markets for system balancing and local congestion management. New market tools for exploiting and maintaining a degree of control over demand are developed, and the value of DR using...

  20. Environment-quality demands

    International Nuclear Information System (INIS)

    Delfini, M.G.; Leenhouts, H.P.

    1988-12-01

    In the framework of the Environment Quality Requirements (MKE) project a model has been designed in which environment-quality demands have been defined and quantified, and a measuring strategy has been developed. In the model it is required for the quality of the environment that the radionuclide concentration in the various environment compartiments remains limited in order to keep the effective dose equivalence for the 'reference man' under a certain reference level. In order to be able to determine the maximum nuclide concentration it is necessary to quantify the relation between the concentration in the environment and the dose for the people. The quantitative relation between concentration and dose has been established on the base of parameters (Derived Activity Limits (DAL's) which have to be calculated for each environment compartiment, each nuclide and each exposure pathway. This model has been described and, as example, the DAL's have been calculated for the compartiment air (for which the two exposure pathways inhalation and direct radiation were considered). For the other environment compartiments a similar elaboration is needed. The feasibility of application of the MKE-model in the actual practice of measurements in the environment and examination of dose for the population depends upon the possibility for performing nuclide specific measurements in all environment compartiments, the level of the dose resulting from the contamination of the environment and the related accurateness of the measurements

  1. Controlling Cocaine: Supplying Versus Demand Programs

    Science.gov (United States)

    1994-01-01

    treatment dura - tions are less than a year, which means that each treatment space can serve more than one person during a year and the cost per admission...May-June, pp. 355-365. Holloway, Marguerite (1991), "Rx for Addiction," Scientific American, March, pp. 93- 103. Holmes, Steven A. (1993), "Coca

  2. Controlling Cocaine. Supply Versus Demand Programs

    Science.gov (United States)

    1994-01-01

    On average, treatment dura - tions are less than a year, which means that each treatment space can serve more than one person during a year and the...39, No. 3, May-June, pp. 355-365. Holloway, Marguerite (1991), "Rx for Addiction," Scientific American, March, pp. 93- 103. Holmes, Steven A. (1993

  3. Demand-Side Flexibility for Energy Transitions: Policy Recommendations for Developing Demand Response

    OpenAIRE

    Nursimulu, Anjali; Florin, Marie-Valentine; Vuille, François

    2016-01-01

    As a follow-up to IRGC's report on demand-side flexibility for energy transitions, this Policy Brief highlights that increasing flexibility in power systems is needed to accommodate higher shares of non-controllable and intermittent renewable generation, and that this requires changes to the market design and regulatory framework, to facilitate the development and deployment of appropriate technologies and market-based instruments (e.g. taxes and subsidies). The Policy Brief focuses on demand...

  4. Modelling Commodity Demands and Labour Supply with m-Demands

    OpenAIRE

    Browning, Martin

    1999-01-01

    In the empirical modelling of demands and labour supply we often lack data on a full set of goods. The usual response is to invoke separability assumptions. Here we present an alternative based on modelling demands as a function of prices and the quantity of a reference good rather than total expenditure. We term such demands m-demands. The advantage of this approach is that we make maximum use of the data to hand without invoking implausible separability assumptions. In the theory section qu...

  5. Demand Externalities from Co-Location

    OpenAIRE

    Boudhayan Sen; Jiwoong Shin; K. Sudhir

    2012-01-01

    We illustrate an approach to measure demand externalities from co-location by estimating household level changes in grocery spending at a supermarket among households that also buy gas at a co-located gas station, relative to those who do not. Controlling for observable and unobserved selection in the use of gas station, we find significant demand externalities; on average a household that buys gas has 7.7% to 9.3% increase in spending on groceries. Accounting for differences in gross margins...

  6. Task demand, task management, and teamwork

    Energy Technology Data Exchange (ETDEWEB)

    Braarud, Per Oeivind; Brendryen, Haavar

    2001-03-15

    The current approach to mental workload assessment in process control was evaluated in 3 previous HAMMLAB studies, by analysing the relationship between workload related measures and performance. The results showed that subjective task complexity rating was related to team's control room performance, that mental effort (NASA-TLX) was weakly related to performance, and that overall activity level was unrelated to performance. The results support the argument that general cognitive measures, i.e., mental workload, are weakly related to performance in the process control domain. This implies that other workload concepts than general mental workload are needed for valid assessment of human reliability and for valid assessment of control room configurations. An assessment of task load in process control suggested that how effort is used to handle task demand is more important then the level of effort invested to solve the task. The report suggests two main workload related concepts with a potential as performance predictors in process control: task requirements, and the work style describing how effort is invested to solve the task. The task requirements are seen as composed of individual task demand and team demand. In a similar way work style are seen as composed of individual task management and teamwork style. A framework for the development of the concepts is suggested based on a literature review and experiences from HAMMLAB research. It is suggested that operational definitions of workload concepts should be based on observable control room behaviour, to assure a potential for developing performance-shaping factors. Finally an explorative analysis of teamwork measures and performance in one study indicated that teamwork concepts are related to performance. This lends support to the suggested development of team demand and teamwork style as elements of a framework for the analysis of workload in process control. (Author)

  7. The Integron: Adaptation On Demand.

    Science.gov (United States)

    Escudero, José Antonio; Loot, Céline; Nivina, Aleksandra; Mazel, Didier

    2015-04-01

    The integron is a powerful system which, by capturing, stockpiling, and rearranging new functions carried by gene encoding cassettes, confers upon bacteria a rapid adaptation capability in changing environments. Chromosomally located integrons (CI) have been identified in a large number of environmental Gram-negative bacteria. Integron evolutionary history suggests that these sedentary CIs acquired mobility among bacterial species through their association with transposable elements and conjugative plasmids. As a result of massive antibiotic use, these so-called mobile integrons are now widespread in clinically relevant bacteria and are considered to be the principal agent in the emergence and rise of antibiotic multiresistance in Gram-negative bacteria. Cassette rearrangements are catalyzed by the integron integrase, a site-specific tyrosine recombinase. Central to these reactions is the single-stranded DNA nature of one of the recombination partners, the attC site. This makes the integron a unique recombination system. This review describes the current knowledge on this atypical recombination mechanism, its implications in the reactions involving the different types of sites, attC and attI, and focuses on the tight regulation exerted by the host on integron activity through the control of attC site folding. Furthermore, cassette and integrase expression are also highly controlled by host regulatory networks and the bacterial stress (SOS) response. These intimate connections to the host make the integron a genetically stable and efficient system, granting the bacteria a low cost, highly adaptive evolution potential "on demand".

  8. Global energy demand outlook

    International Nuclear Information System (INIS)

    Hatcher, S.R.

    1999-01-01

    Perhaps the most compelling issue the world will face in the next century is the quality of life of the increasing populations of the poorer regions of the world. Energy is the key to generating wealth and protecting the environment. Today, most of the energy generated comes from fossil fuels and there should be enough for an increase in consumption over the next half century. However, this is likely to be impacted by the Kyoto Protocol on carbon dioxide emissions. Various authoritative studies lead to a global energy demand projection of between 850 to 1070 EJ per year in the mid-21 st century, which is nearly three times as much as the world uses today. The studies further indicate that, unless there is a major thrust by governments to create incentives and/or to levy heavy taxes, the use of fossil fuels will continue to increase and there will be a major increase in carbon dioxide emissions globally. Most of the increase will come from the newly industrializing countries which do not have the technology or financial resources to install non-carbon energy sources such as nuclear power, and the new renewable energy technologies. The real issue for the nuclear industry is investment cost. Developing countries, in particular will have difficulty in raising capital for energy projects with a high installed cost and will have difficulties in raising large blocks of capital. A reduction in investment costs of the order of 50% with a short construction schedule is in order if nuclear power is to compete and contribute significantly to energy supply and the reduction of carbon dioxide emissions. Current nuclear power plants and methods are simply not suited to the production of plants that will compete in this situation. Mass production designs are needed to get the benefits of cost reduction. Water cooled reactors are well demonstrated and positioned to achieve the cost reduction necessary but only via some radical thinking on the part of the designers. The reactors of

  9. Promotion and Fast Food Demand

    OpenAIRE

    Timothy J. Richards; Luis Padilla

    2009-01-01

    Many believe that fast food promotion is a significant cause of the obesity epidemic in North America. Industry members argue that promotion only reallocates brand shares and does not increase overall demand. We study the effect of fast food promotion on market share and total demand by estimating a discrete / continuous model of fast food restaurant choice and food expenditure that explicitly accounts for both spatial and temporal determinants of demand. Estimates are obtained using a unique...

  10. Intercity Travel Demand Analysis Model

    OpenAIRE

    Ming Lu; Hai Zhu; Xia Luo; Lei Lei

    2014-01-01

    It is well known that intercity travel is an important component of travel demand which belongs to short distance corridor travel. The conventional four-step method is no longer suitable for short distance corridor travel demand analysis for the time spent on urban traffic has a great impact on traveler's main mode choice. To solve this problem, the author studied the existing intercity travel demand analysis model, then improved it based on the study, and finally established a combined model...

  11. Job demands-resources model

    OpenAIRE

    Bakker, Arnold; Demerouti, Eva

    2013-01-01

    markdownabstract* The question of what causes job stress and what motivates people has received a lot of research attention during the past five decades. In this paper, we discuss Job Demands-Resources (JD-R) theory, which represents an extension of the Job Demands-Resources model (Bakker & Demerouti, 2007; Demerouti, Bakker, Nachreiner, & Schaufeli, 2001) and is inspired by job design and job stress theories. JD-R theory explains how job demands and resources have unique and multiplicative e...

  12. North American oil demand outlook

    International Nuclear Information System (INIS)

    Stewart, M.B.

    1995-01-01

    An understanding of the relationship of economic growth and potential petroleum product demand is needed to forecast the potential for North American oil demand growth as well as knowledge of world supply and price. The bullish expectations for economic growth in the US and Canada auger well for North American refiners and marketeers. The growth in world economic output forecast, however, means a larger oil demand and an increase in OPEC's pricing power. Such price increases could depress North American oil demand growth. (author)

  13. Benefits and challenges of electrical demand response: A critical review

    DEFF Research Database (Denmark)

    O'Connell, Niamh; Pinson, Pierre; Madsen, Henrik

    2014-01-01

    and challenges of demand response. These benefits include the ability to balance fluctuations in renewable generation and consequently facilitate higher penetrations of renewable resources on the power system, an increase in economic efficiency through the implementation of real-time pricing, and a reduction...... in generation capacity requirements. Nevertheless, demand response is not without its challenges. The key challenges for demand response centre around establishing reliable control strategies and market frameworks so that the demand response resource can be used optimally. One of the greatest challenges...... for demand response is the lack of experience, and the consequent need to employ extensive assumptions when modelling and evaluating this resource. This paper concludes with an examination of these assumptions, which range from assuming a fixed linear price–demand relationship for price responsive demand...

  14. Women demand development.

    Science.gov (United States)

    Birch, I

    2000-07-01

    This study was conducted by a research team in Dar es Salaam to identify which policy changes might strengthen rural food security in Tanzania. The participatory research revealed much about the impact of gender and culture on food security. In both districts of Ngorongoro and Shinyanga, control of resources favored men. They managed the income from high-value resources like cattle, cotton, and maize, while women managed low-value resources like milk, hides, and goats. Also, it was evident that in both districts, violence against women had an impact on women's confidence and levels of control, and was felt to exacerbate food insecurity. In view of this, the research recommends support to groups of women and youths to organize themselves and lobby for change, as well as support to government and other officials to help them listen to those voices and respond more effectively.

  15. Harnessing the power of demand

    Energy Technology Data Exchange (ETDEWEB)

    Sheffrin, Anjali; Yoshimura, Henry; LaPlante, David; Neenan, Bernard

    2008-03-15

    Demand response can provide a series of economic services to the market and also provide ''insurance value'' under low-likelihood, but high-impact circumstances in which grid reliablity is enhanced. Here is how ISOs and RTOs are fostering demand response within wholesale electricity markets. (author)

  16. Guidelines for forecasting energy demand

    International Nuclear Information System (INIS)

    Sonino, T.

    1976-11-01

    Four methodologies for forecasting energy demand are reviewed here after considering the role of energy in the economy and the analysis of energy use in different economic sectors. The special case of Israel is considered throughout, and some forecasts for energy demands in the year 2000 are presented. An energy supply mix that may be considered feasible is proposed. (author)

  17. Coal background paper. Coal demand

    International Nuclear Information System (INIS)

    1997-01-01

    Statistical data are presented on coal demands in IEA and OECD member countries and in other countries. Coal coaking and coaking coal consumption data are tabulated, and IEA secretariat's coal demand projections are summarized. Coal supply and production data by countries are given. Finally, coal trade data are presented, broken down for hard coal, steam coal, coking coal (imports and export). (R.P.)

  18. Uranium resources, demand and production

    International Nuclear Information System (INIS)

    Stipanicic, P.N.

    1985-05-01

    Estimations of the demand and production of principal uranium resource categories are presented. The estimations based on data analysis made by a joint 'NEA/IAEA Working Party on Uranium Resources' and the corresponding results are published by the OECD (Organization for Economic Co-operation and Development) in the 'Uranium Resources, Production and Demand' Known as 'Red Book'. (M.C.K.) [pt

  19. Demand differentiation in inventory systems

    NARCIS (Netherlands)

    Kleijn, M.J.

    1998-01-01

    This book deals with inventory systems where customer demand is categorised into different classes. Most inventory systems do not take into account individual customer preferences for a given product, and therefore handle all demand in a similar way. Nowadays, market segmentation has become a

  20. Demand Response in Smart Grids

    DEFF Research Database (Denmark)

    Hansen, Jacob; Knudsen, Jesper Viese; Annaswamy, Anuradha M.

    2014-01-01

    In recent decades, moves toward higher integration of Renewable Energy Resources have called for fundamental changes in both the planning and operation of the overall power grid. One such change is the incorporation of Demand Response (DR), the process by which consumers can adjust their demand...

  1. Credit demand in Mozambican manufacturing

    DEFF Research Database (Denmark)

    Byiers, Bruce; Rand, John; Tarp, Finn

    2010-01-01

    This paper uses two industrial firm surveys to identify the key determinants of credit demand in Mozambican manufacturing. We construct five different measures of being credit constrained and estimate desired debt demand. Besides firm size and ownership structure, we find evidence that general...

  2. Job demands-resources model

    NARCIS (Netherlands)

    A.B. Bakker (Arnold); E. Demerouti (Eva)

    2013-01-01

    markdownabstract* The question of what causes job stress and what motivates people has received a lot of research attention during the past five decades. In this paper, we discuss Job Demands-Resources (JD-R) theory, which represents an extension of the Job Demands-Resources model (Bakker &

  3. Residential energy demand in Brazil

    International Nuclear Information System (INIS)

    Arouca, M.; Gomes, F.M.; Rosa, L.P.

    1981-01-01

    The energy demand in Brazilian residential sector is studied, discussing the methodology for analyzing this demand from some ideas suggested, for developing an adequate method to brazilian characteristics. The residential energy consumption of several fuels in Brazil is also presented, including a comparative evaluation with the United States and France. (author)

  4. Demand uncertainty and investment in the restaurant industry

    OpenAIRE

    Sohn, Jayoung

    2016-01-01

    Since the collapse of the housing market, the prolonged economic uncertainty lingering in the U.S. economy has dampened restaurant performance. Economic uncertainty affects consumer sentiment and spending, turning into demand uncertainty. Nevertheless, the highly competitive nature of the restaurant industry does not allow much room for restaurants to actively control prices, leaving most food service firms exposed to demand uncertainty. To investigate the impact of demand uncertainty in the ...

  5. Price Elasticity of Alcohol Demand in India.

    Science.gov (United States)

    Kumar, Santosh

    2017-05-01

    Using a household survey conducted in 2014, this study estimates price elasticity of demand (PED) for beer, country liquor and spirits in India. Ordinary least-square models were used to estimate the responsiveness in alcohol demand due to price change. A large number of control variables were included to adjust for potential confounding in the model. Inter-district variation in alcohol consumption is adjusted for by including district fixed effects. Alcohol prices are negatively associated with demand for alcoholic beverages. The PED ranged from -0.14 for spirits to -0.46 for country liquor. Low level of education was positively associated with spirits consumption. The magnitude of elasticity varied by rural-urban, education and gender. Results indicate that a policy mix of price controls and awareness campaigns would be most effective in tackling the adverse effects of harmful drinking in India. The demand for beer, country liquor and spirits is negatively associated with its own price. The elasticity estimates ranged from -0.14 for spirits to -0.44 for country liquor. The elasticity estimates varied by rural-urban, gender and by education levels of the drinkers. © The Author 2017. Medical Council on Alcohol and Oxford University Press. All rights reserved

  6. The Efficacy and Safety of On-demand Tramadol and Paroxetine Use in Treatment of Life Long Premature Ejaculation: A Randomized Double-blind Placebo-controlled Clinical Trial

    Science.gov (United States)

    Hamidi-Madani, Ali; Motiee, Reza; Mokhtari, Gholamreza; Nasseh, Hamidreza; Esmaeili, Samaneh; Kazemnezhad, Ehsan

    2018-01-01

    Background: Several medical therapies have been proposed for the treatment of premature ejaculation (PE). Paroxetine and tramadol were both reported to be effective in treatment of PE. In this study, the therapeutic effects of tramadol, paroxetine and placebo were compared in treatment of primary PE. Methods: In this randomized, double-blind, placebo-controlled clinical trial, 150 patients were divided into 3 groups. One group was treated with tramadol 50 mg ondemand, the other group took paroxetine 20 mg on-demand and the third group was treated with placebo. Before starting treatment and after 12 weeks, patients were asked to measure their average intravaginal ejaculation latency time (IELT) and fill the PEP (Premature Ejaculation Profile) questionnaire. Results: At the end of the 12th week, the mean IELT and average of PEP scores improved in all 3 groups. The increase in tramadol group was significantly higher than the paroxetine and placebo groups (pIELT and PEP scores in all 3 groups, the rate of improvement in tramadol group was significantly more than the others. Thus, tramadol may be considered as an appropriate alternative therapeutic option for lifelong PE. PMID:29850442

  7. The Efficacy and Safety of On-demand Tramadol and Paroxetine Use in Treatment of Life Long Premature Ejaculation: A Randomized Double-blind Placebo-controlled Clinical Trial.

    Science.gov (United States)

    Hamidi-Madani, Ali; Motiee, Reza; Mokhtari, Gholamreza; Nasseh, Hamidreza; Esmaeili, Samaneh; Kazemnezhad, Ehsan

    2018-01-01

    Several medical therapies have been proposed for the treatment of premature ejaculation (PE). Paroxetine and tramadol were both reported to be effective in treatment of PE. In this study, the therapeutic effects of tramadol, paroxetine and placebo were compared in treatment of primary PE. In this randomized, double-blind, placebo-controlled clinical trial, 150 patients were divided into 3 groups. One group was treated with tramadol 50 mg ondemand, the other group took paroxetine 20 mg on-demand and the third group was treated with placebo. Before starting treatment and after 12 weeks, patients were asked to measure their average intravaginal ejaculation latency time (IELT) and fill the PEP (Premature Ejaculation Profile) questionnaire. At the end of the 12th week, the mean IELT and average of PEP scores improved in all 3 groups. The increase in tramadol group was significantly higher than the paroxetine and placebo groups (p<0.0001). There were no significant differences in terms of side effects between the 3 groups. The results showed that despite an increase in mean IELT and PEP scores in all 3 groups, the rate of improvement in tramadol group was significantly more than the others. Thus, tramadol may be considered as an appropriate alternative therapeutic option for lifelong PE.

  8. Demand Response as a System Reliability Resource

    Energy Technology Data Exchange (ETDEWEB)

    Eto, Joseph H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Lewis, Nancy Jo [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Watson, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Kiliccote, Sila [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Auslander, David [Univ. of California, Berkeley, CA (United States); Paprotny, Igor [Univ. of California, Berkeley, CA (United States); Makarov, Yuri [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2012-12-31

    The Demand Response as a System Reliability Resource project consists of six technical tasks: • Task 2.1. Test Plan and Conduct Tests: Contingency Reserves Demand Response (DR) Demonstration—a pioneering demonstration of how existing utility load-management assets can provide an important electricity system reliability resource known as contingency reserve. • Task 2.2. Participation in Electric Power Research Institute (EPRI) IntelliGrid—technical assistance to the EPRI IntelliGrid team in developing use cases and other high-level requirements for the architecture. • Task 2.3. Research, Development, and Demonstration (RD&D) Planning for Demand Response Technology Development—technical support to the Public Interest Energy Research (PIER) Program on five topics: Sub-task 1. PIER Smart Grid RD&D Planning Document; Sub-task 2. System Dynamics of Programmable Controllable Thermostats; Sub-task 3. California Independent System Operator (California ISO) DR Use Cases; Sub-task 4. California ISO Telemetry Requirements; and Sub-task 5. Design of a Building Load Data Storage Platform. • Task 2.4. Time Value of Demand Response—research that will enable California ISO to take better account of the speed of the resources that it deploys to ensure compliance with reliability rules for frequency control. • Task 2.5. System Integration and Market Research: Southern California Edison (SCE)—research and technical support for efforts led by SCE to conduct demand response pilot demonstrations to provide a contingency reserve service (known as non-spinning reserve) through a targeted sub-population of aggregated residential and small commercial customers enrolled in SCE’s traditional air conditioning (AC) load cycling program, the Summer Discount Plan. • Task 2.6. Demonstrate Demand Response Technologies: Pacific Gas and Electric (PG&E)—research and technical support for efforts led by PG&E to conduct a demand response pilot demonstration to provide non

  9. Worldwide satellite market demand forecast

    Science.gov (United States)

    Bowyer, J. M.; Frankfort, M.; Steinnagel, K. M.

    1981-01-01

    The forecast is for the years 1981 - 2000 with benchmark years at 1985, 1990 and 2000. Two typs of markets are considered for this study: Hardware (worldwide total) - satellites, earth stations and control facilities (includes replacements and spares); and non-hardware (addressable by U.S. industry) - planning, launch, turnkey systems and operations. These markets were examined for the INTELSAT System (international systems and domestic and regional systems using leased transponders) and domestic and regional systems. Forecasts were determined for six worldwide regions encompassing 185 countries using actual costs for existing equipment and engineering estimates of costs for advanced systems. Most likely (conservative growth rate estimates) and optimistic (mid range growth rate estimates) scenarios were employed for arriving at the forecasts which are presented in constant 1980 U.S. dollars. The worldwide satellite market demand forecast predicts that the market between 181 and 2000 will range from $35 to $50 billion. Approximately one-half of the world market, $16 to $20 billion, will be generated in the United States.

  10. BATMAN: MOS Spectroscopy on Demand

    Science.gov (United States)

    Molinari, E.; Zamkotsian, F.; Moschetti, M.; Spano, P.; Boschin, W.; Cosentino, R.; Ghedina, A.; González, M.; Pérez, H.; Lanzoni, P.; Ramarijaona, H.; Riva, M.; Zerbi, F.; Nicastro, L.; Valenziano, L.; Di Marcantonio, P.; Coretti, I.; Cirami, R.

    2016-10-01

    Multi-Object Spectrographs (MOS) are the major instruments for studying primary galaxies and remote and faint objects. Current object selection systems are limited and/or difficult to implement in next generation MOS for space and ground-based telescopes. A promising solution is the use of MOEMS devices such as micromirror arrays, which allow the remote control of the multi-slit configuration in real time. TNG is hosting a novelty project for real-time, on-demand MOS masks based on MOEMS programmable slits. We are developing a 2048×1080 Digital-Micromirror-Device-based (DMD) MOS instrument to be mounted on the Galileo telescope, called BATMAN. It is a two-arm instrument designed for providing in parallel imaging and spectroscopic capabilities. With a field of view of 6.8×3.6 arcmin and a plate scale of 0.2 arcsec per micromirror, this astronomical setup can be used to investigate the formation and evolution of galaxies. The wavelength range is in the visible and the spectral resolution is R=560 for a 1 arcsec object, and the two arms will have 2k × 4k CCD detectors. ROBIN, a BATMAN demonstrator, has been designed, realized and integrated. We plan to have BATMAN first light by mid-2016.

  11. Are demand forecasting techniques applicable to libraries?

    OpenAIRE

    Sridhar, M. S.

    1984-01-01

    Examines the nature and limitations of demand forecasting, discuses plausible methods of forecasting demand for information, suggests some useful hints for demand forecasting and concludes by emphasizing unified approach to demand forecasting.

  12. The job demands-resources model : state of the art

    NARCIS (Netherlands)

    Bakker, A.B.; Demerouti, E.

    2007-01-01

    Purpose - The purpose of this paper is to give a state-of-the art overview of the Job Demands-Resources (JD-R) model Design/methodology/approach - The strengths and weaknesses of the demand-control model and the effort-reward imbalance model regarding their predictive value for employee well being

  13. Monetary Policy and Credit Demand in India and Some EMEs

    OpenAIRE

    B L Pandit; Pankaj Vashisht

    2012-01-01

    Impact of changes in policy rate of interest on demand for bank credit is examined for seven emerging market economies including India for the period 2002 to 2010. Panel data techniques are used after ruling out the presence of unit roots. The results show that when other determinants, like domestic demand pressure, export demand and impact of stock market signals are controlled for, change in policy rate of interest is an important determinant of firms’ demand for bank credit. The results ...

  14. Opportunities for Automated Demand Response in California Agricultural Irrigation

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Daniel [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Aghajanzadeh, Arian [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); McKane, Aimee [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-08-01

    Pumping water for agricultural irrigation represents a significant share of California’s annual electricity use and peak demand. It also represents a large source of potential flexibility, as farms possess a form of storage in their wetted soil. By carefully modifying their irrigation schedules, growers can participate in demand response without adverse effects on their crops. This report describes the potential for participation in demand response and automated demand response by agricultural irrigators in California, as well as barriers to widespread participation. The report first describes the magnitude, timing, location, purpose, and manner of energy use in California. Typical on-­farm controls are discussed, as well as common impediments to participation in demand response and automated demand response programs. Case studies of demand response programs in California and across the country are reviewed, and their results along with overall California demand estimates are used to estimate statewide demand response potential. Finally, recommendations are made for future research that can enhance the understanding of demand response potential in this industry.

  15. Energy demand: Facts and trends

    Energy Technology Data Exchange (ETDEWEB)

    Chateau, B; Lapillonne, B

    1982-01-01

    The relationship between economic development and energy demand is investigated in this book. It gives a detailed analysis of the energy demand dynamics in industrialized countries and compares the past evolution of the driving factors behind energy demand by sector and by end-uses for the main OECD countries: residential sector (space heating, water heating, cooking...), tertiary sector, passenger and goods transport by mode, and industry (with particular emphasis on the steel and cement industry). This analysis leads to a more precise understanding of the long-term trends of energy demand; highlighting the influence on these trends of energy prices, especially after the oil price shocks, and of the type of economic development pattern.

  16. Temperature Effect on Energy Demand

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Duk [Korea Energy Economics Institute, Euiwang (Korea)

    1999-03-01

    We provide various estimates of temperature effect for accommodating seasonality in energy demand, particularly natural gas demand. We exploit temperature response and monthly temperature distribution to estimate the temperature effect on natural gas demand. Both local and global smoothed temperature responses are estimated from empirical relationship between hourly temperature and hourly energy consumption data during the sample period (1990 - 1996). Monthly temperature distribution estimates are obtained by kernel density estimation from temperature dispersion within a month. We integrate temperature response and monthly temperature density over all the temperatures in the sample period to estimate temperature effect on energy demand. Then, estimates of temperature effect are compared between global and local smoothing methods. (author). 15 refs., 14 figs., 2 tabs.

  17. Demand Response Spinning Reserve Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Eto, Joseph H.; Nelson-Hoffman, Janine; Torres, Carlos; Hirth,Scott; Yinger, Bob; Kueck, John; Kirby, Brendan; Bernier, Clark; Wright,Roger; Barat, A.; Watson, David S.

    2007-05-01

    The Demand Response Spinning Reserve project is a pioneeringdemonstration of how existing utility load-management assets can providean important electricity system reliability resource known as spinningreserve. Using aggregated demand-side resources to provide spinningreserve will give grid operators at the California Independent SystemOperator (CAISO) and Southern California Edison (SCE) a powerful, newtool to improve system reliability, prevent rolling blackouts, and lowersystem operating costs.

  18. Television Advertising and Soda Demand

    OpenAIRE

    Lopez, Rigoberto A.; Liu, Yizao; Zhu, Chen

    2012-01-01

    This study examines the effects of television advertising on consumer demand for carbonated soft drinks using a random coefficients logit model (BLP) with household and advertising data from seven U.S. cities over a three year period. We find that advertising decreases the price elasticity of demand, indicating that advertising plays predominantly a persuasive, therefore anti-competitive role in this market. Further results show that brand spillover effects are significant and that measuring ...

  19. Balancing supply and demand resources

    International Nuclear Information System (INIS)

    Sinha, J.; Saleeby, R.G.

    1990-01-01

    This article deals with using demand-side management (DSM) resources as an effective means of balancing supply and demand as a part of least-cost planning. The authors present a more sophisticated application of the load forecast adjustment method that reduces the number of DSM programs that need to be evaluated and provides blocks large enough to eliminate resolution problems in production costing models

  20. Aviation Frontiers: On-Demand Aircraft

    Science.gov (United States)

    Moore, Mark D.

    2010-01-01

    Throughout the 20th Century, NASA has defined the forefront of aeronautical technology, and the aviation industry owes much of its prosperity to this knowledge and technology. In recent decades, centralized aeronautics has become a mature discipline, which raises questions concerning the future aviation innovation frontiers. Three transformational aviation capabilities, bounded together by the development of a Free Flight airspace management system, have the potential to transform 21st Century society as profoundly as civil aviation transformed the 20th Century. These mobility breakthroughs will re-establish environmental sustainable centralized aviation, while opening up latent markets for civil distributed sensing and on-demand rural and regional transportation. Of these three transformations, on-demand aviation has the potential to have the largest market and productivity improvement to society. The information system revolution over the past 20 years shows that vehicles lead, and the interconnecting infrastructure to make them more effective follows; that is, unless on-demand aircraft are pioneered, a distributed Air Traffic Control system will likely never be established. There is no single technology long-pole that will enable on-demand vehicle solutions. However, fully digital aircraft that include electric propulsion has the potential to be a multi-disciplinary initiator of solid state technologies that can provide order of magnitude improvements in the ease of use, safety/reliability, community and environmental friendliness, and affordability.

  1. A consolidated solution of a demand dispatch problem for different demand response schemes

    NARCIS (Netherlands)

    Babar, M.; Nguyen, P.H.; Cuk, V.; Kamphuis, I.G.

    2014-01-01

    Advance infrastructures have changed the passive consumers into active because now they can share information, perform automatic control as well as directly influence the electricity market via demand response (DR) programs. Till today, many DR Programs are proposed in Smart Grid (SG) paradigm and

  2. Opportunities for Automated Demand Response in California Wastewater Treatment Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Aghajanzadeh, Arian [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wray, Craig [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); McKane, Aimee [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-08-30

    Previous research over a period of six years has identified wastewater treatment facilities as good candidates for demand response (DR), automated demand response (Auto-­DR), and Energy Efficiency (EE) measures. This report summarizes that work, including the characteristics of wastewater treatment facilities, the nature of the wastewater stream, energy used and demand, as well as details of the wastewater treatment process. It also discusses control systems and automated demand response opportunities. Furthermore, this report summarizes the DR potential of three wastewater treatment facilities. In particular, Lawrence Berkeley National Laboratory (LBNL) has collected data at these facilities from control systems, submetered process equipment, utility electricity demand records, and governmental weather stations. The collected data were then used to generate a summary of wastewater power demand, factors affecting that demand, and demand response capabilities. These case studies show that facilities that have implemented energy efficiency measures and that have centralized control systems are well suited to shed or shift electrical loads in response to financial incentives, utility bill savings, and/or opportunities to enhance reliability of service. In summary, municipal wastewater treatment energy demand in California is large, and energy-­intensive equipment offers significant potential for automated demand response. In particular, large load reductions were achieved by targeting effluent pumps and centrifuges. One of the limiting factors to implementing demand response is the reaction of effluent turbidity to reduced aeration at an earlier stage of the process. Another limiting factor is that cogeneration capabilities of municipal facilities, including existing power purchase agreements and utility receptiveness to purchasing electricity from cogeneration facilities, limit a facility’s potential to participate in other DR activities.

  3. Stochastic model of forecasting spare parts demand

    OpenAIRE

    Ivan S. Milojević; Rade V. Guberinić

    2012-01-01

    If demand is known for the whole planning period (complete information), then this type of demand or a supply system is deterministic. In the simplest cases, the demand per time unit is constant. If demand levels change over time following a precisely determined and pre-known principle, this type of demand is also classified as deterministic. This quality of demand is very rare. In most cases demand is the product of a process, for example TMS maintenance, whose progression cannot be predicte...

  4. A decision aiding and action management tool to control the energy demand - from conception to development; Un outil d`aide a la decision et de gestion des actions pour la maitrise de la demande d`energie - de la conception au developpement

    Energy Technology Data Exchange (ETDEWEB)

    Kaehler, J W.M.

    1993-07-06

    This work presents a synthesis of three points: the environment, energy and man. The consideration of these aspects allows us to confront the unequal distribution of energy resources, the constraints and political influences which determine the exploitation of these energy resources, and the concentration of the consumption of energy by one fifth of the world`s population and the perspective of future growth of energy use by the remaining four-fifths. It is understanding of the importance and the benefits of reducing energy requirements, combined with the environmental perspectives, that forms the core of the Integrated Resource Planning of Least is proposed. This framework will utilize the knowledge of the engineer for developing a system to aid with decision making and the management of information, and particularly with the notions henceforth referred to as `Demand-Site Management` as applied to the electrical grid. The model of such a Management Information System which demonstrates these theoretical advances is called SIADEME (Systeme Interactif d`Aide a la Decision et de Gestion des Actions de Maitrise de la Demande d`energie). This includes some examples for the management of electricity demand for both the lighting and refrigeration cases in large (> 2500 m{sup 2}) supermarkets for the French environmental and energy management agency (Ademe). (author) 216 refs.

  5. Pattern of Demand For Money

    Directory of Open Access Journals (Sweden)

    Ahmad Berlian

    2017-12-01

    Full Text Available In the activity of the modern economy, the availability of money as a means of transaction is very important, because with the money as a means to pay consumers can easily to get the basic material needs are required, the manufacturer can provide the raw materials of labor for production, and distributors can obtain a variety of merchandise to be delivered at the end consumer. The pattern of use of money is influenced by the attitude of the public in the transaction. Researchers assume, that there are differences among communities, either by group differences in income, educational differences, ethnic differences, differences in profession, and perhaps even religious differences embraced. So as to provide information to the monetary authorities, to enrich the theory of demand for money based economic agents in Indonesia, and for the application of the theory of demand for money, the researchers felt the need to study patterns of use of money. Qualitative research, in addition to knowing whether the variables that affect the demand for money as the above theory is still relevant for economic actors in Indonesia at this time, or even are new variables, as well as the motive of money demand. Keywords: Demand for money, Keynes Theory, qualitative method

  6. Demands on digital automation; Anforderungen an die Digitale Automation

    Energy Technology Data Exchange (ETDEWEB)

    Bieler, P.

    1995-12-31

    In chapter 12 of the anthology about building control the demands on digital automation are presented. The following aspects are discussed: variety of the companies` philosophies, demands of the customer/investor, demands of the use of buildings/rooms, the user, point of view of manufacturer of technical plants. (BWI) [Deutsch] Kapitel 12 des Sammelbandes ueber Building Control stellt die Anforderungen an die Digitale Automation vor. In diesem Zusammenhang wird auf folgende Themenbereiche eingegangen: Spektrum der Firmenphilosophien, Forderungen der Auftraggeber/Investoren, der Gebaeude-/Raumnutzung, der Betreiber sowie Sicht der Ersteller betriebstechnischer Anlagen. (BWI)

  7. US residential energy demand and energy efficiency: A stochastic demand frontier approach

    International Nuclear Information System (INIS)

    Filippini, Massimo; Hunt, Lester C.

    2012-01-01

    This paper estimates a US frontier residential aggregate energy demand function using panel data for 48 ‘states’ over the period 1995 to 2007 using stochastic frontier analysis (SFA). Utilizing an econometric energy demand model, the (in)efficiency of each state is modeled and it is argued that this represents a measure of the inefficient use of residential energy in each state (i.e. ‘waste energy’). This underlying efficiency for the US is therefore observed for each state as well as the relative efficiency across the states. Moreover, the analysis suggests that energy intensity is not necessarily a good indicator of energy efficiency, whereas by controlling for a range of economic and other factors, the measure of energy efficiency obtained via this approach is. This is a novel approach to model residential energy demand and efficiency and it is arguably particularly relevant given current US energy policy discussions related to energy efficiency.

  8. Spatial dimensions of the demand for homeownership

    DEFF Research Database (Denmark)

    Sørensen, Jens Fyhn Lykke

    2010-01-01

    This paper introduces the concept of "spatial location satisfaction" and examines its relation to the individual demand for homeownership. Based on a Danish questionnaire survey carried out in a rural study area (N=1000) and in an urban study area (N=1015), a tenure choice model was estimated...... relating spatial location satisfaction to homeownership, while adjusting for control variables. The spatial location satisfaction variable was constructed from two questionnaire items asking respondents to state their actual and preferred place of settlement given five location type options: large city......, medium-sized city, small town, village, and "in the countryside". As hypothesised, the study shows a strong association between spatial location satisfaction and the individual demand for homeownership. This association is robust across study areas. Spatial location satisfaction is highest in the rural...

  9. Energy supply and demand in California

    Science.gov (United States)

    Griffith, E. D.

    1978-01-01

    The author expresses his views on future energy demand on the west coast of the United States and how that energy demand translates into demand for major fuels. He identifies the major uncertainties in determining what future demands may be. The major supply options that are available to meet projected demands and the policy implications that flow from these options are discussed.

  10. International Oil Supplies and Demands

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    The eleventh Energy Modeling Forum (EMF) working group met four times over the 1989--90 period to compare alternative perspectives on international oil supplies and demands through 2010 and to discuss how alternative supply and demand trends influence the world's dependence upon Middle Eastern oil. Proprietors of eleven economic models of the world oil market used their respective models to simulate a dozen scenarios using standardized assumptions. From its inception, the study was not designed to focus on the short-run impacts of disruptions on oil markets. Nor did the working group attempt to provide a forecast or just a single view of the likely future path for oil prices. The model results guided the group's thinking about many important longer-run market relationships and helped to identify differences of opinion about future oil supplies, demands, and dependence.

  11. Fundamental Travel Demand Model Example

    Science.gov (United States)

    Hanssen, Joel

    2010-01-01

    Instances of transportation models are abundant and detailed "how to" instruction is available in the form of transportation software help documentation. The purpose of this paper is to look at the fundamental inputs required to build a transportation model by developing an example passenger travel demand model. The example model reduces the scale to a manageable size for the purpose of illustrating the data collection and analysis required before the first step of the model begins. This aspect of the model development would not reasonably be discussed in software help documentation (it is assumed the model developer comes prepared). Recommendations are derived from the example passenger travel demand model to suggest future work regarding the data collection and analysis required for a freight travel demand model.

  12. International Oil Supplies and Demands

    International Nuclear Information System (INIS)

    1991-09-01

    The eleventh Energy Modeling Forum (EMF) working group met four times over the 1989--90 period to compare alternative perspectives on international oil supplies and demands through 2010 and to discuss how alternative supply and demand trends influence the world's dependence upon Middle Eastern oil. Proprietors of eleven economic models of the world oil market used their respective models to simulate a dozen scenarios using standardized assumptions. From its inception, the study was not designed to focus on the short-run impacts of disruptions on oil markets. Nor did the working group attempt to provide a forecast or just a single view of the likely future path for oil prices. The model results guided the group's thinking about many important longer-run market relationships and helped to identify differences of opinion about future oil supplies, demands, and dependence

  13. International Oil Supplies and Demands

    International Nuclear Information System (INIS)

    1992-04-01

    The eleventh Energy Modeling Forum (EMF) working group met four times over the 1989--1990 period to compare alternative perspectives on international oil supplies and demands through 2010 and to discuss how alternative supply and demand trends influence the world's dependence upon Middle Eastern oil. Proprietors of eleven economic models of the world oil market used their respective models to simulate a dozen scenarios using standardized assumptions. From its inception, the study was not designed to focus on the short-run impacts of disruptions on oil markets. Nor did the working group attempt to provide a forecast or just a single view of the likely future path for oil prices. The model results guided the group's thinking about many important longer-run market relationships and helped to identify differences of opinion about future oil supplies, demands, and dependence

  14. Consumer demand and quality assurance

    DEFF Research Database (Denmark)

    Grunert, Klaus G; Wognum, Nel; Trienekens, Jacques

    2011-01-01

    Consumers differ in their demands, and this mau have implications for the type of supply chain governance that is most suitable for serving them. We present a segmentation of pork consumers in the EU based on their food-related lifestyles and demand for different pork products. We then present...... an inventory of pork chain governance and quality management systems, also resulting from a pan-European study, and attempt to match types of chains to consumer segments, arguing that the type of quality demanded by the consumers has implications especially for the quality management system governing the chain......, and that these implications are different for fresh meat and processed meat. The paper closes with a call for more collaboration between chain researchers and consumer researchers....

  15. International Oil Supplies and Demands

    Energy Technology Data Exchange (ETDEWEB)

    1992-04-01

    The eleventh Energy Modeling Forum (EMF) working group met four times over the 1989--1990 period to compare alternative perspectives on international oil supplies and demands through 2010 and to discuss how alternative supply and demand trends influence the world's dependence upon Middle Eastern oil. Proprietors of eleven economic models of the world oil market used their respective models to simulate a dozen scenarios using standardized assumptions. From its inception, the study was not designed to focus on the short-run impacts of disruptions on oil markets. Nor did the working group attempt to provide a forecast or just a single view of the likely future path for oil prices. The model results guided the group's thinking about many important longer-run market relationships and helped to identify differences of opinion about future oil supplies, demands, and dependence.

  16. North American supply/demand

    International Nuclear Information System (INIS)

    Pocino, M.C.

    1998-01-01

    The projected supply and demand for natural gas in five major regions of North America for the year 2000 was presented. In most regions, supply is expected to be greater than demand. A summary of how California dealt with an increase in natural gas demand in 1990 was presented. The California strategy included a readjustment of pipeline capacity, storage capacity and transportation. Whereas in the 1980s, when capacity was inadequate, the focus was on competition with alternate fuels, maximized capacity use, primary concern about reliability and only secondary concern about price, in the the 1990s, with excess capacity, the emphasis is on 'gas on gas' competition, efforts to satisfy the customer, primary concern about price, and only marginal concern about reliability. tabs., figs

  17. Supplies should match growing demand

    International Nuclear Information System (INIS)

    Rasmusen, H.J.

    1997-01-01

    The natural gas industry is currently enjoying healthy growth prospects. Not only is the demand for natural gas steadily growing; the outlook for increasing gas reserves is promising as well. The success of natural gas in the marketplace reflects, on one hand, continuous attention paid to public and customer requirements and, on the other hand, the ability of the gas industry to direct technological developments toward the increasing public demand for gas at competitive market prices supplied in a reliable, safe and environmentally friendly manner. In the past, the gas industry has been involved in the development of technologies for everything from gas production to the end user and from borehole to burner tip, and the author believes that the industry must continue or even increase its emphasis on technology in the future in order to capture new market opportunities. He explains this by looking at the supply side, the demand side and the structural side of the business

  18. Demand curves for hypothetical cocaine in cocaine-dependent individuals.

    Science.gov (United States)

    Bruner, Natalie R; Johnson, Matthew W

    2014-03-01

    Drug purchasing tasks have been successfully used to examine demand for hypothetical consumption of abused drugs including heroin, nicotine, and alcohol. In these tasks, drug users make hypothetical choices whether to buy drugs, and if so, at what quantity, at various potential prices. These tasks allow for behavioral economic assessment of that drug's intensity of demand (preferred level of consumption at extremely low prices) and demand elasticity (sensitivity of consumption to price), among other metrics. However, a purchasing task for cocaine in cocaine-dependent individuals has not been investigated. This study examined a novel Cocaine Purchasing Task and the relation between resulting demand metrics and self-reported cocaine use data. Participants completed a questionnaire assessing hypothetical purchases of cocaine units at prices ranging from $0.01 to $1,000. Demand curves were generated from responses on the Cocaine Purchasing Task. Correlations compared metrics from the demand curve to measures of real-world cocaine use. Group and individual data were well modeled by a demand curve function. The validity of the Cocaine Purchasing Task was supported by a significant correlation between the demand curve metrics of demand intensity and O max (determined from Cocaine Purchasing Task data) and self-reported measures of cocaine use. Partial correlations revealed that after controlling for demand intensity, demand elasticity and the related measure, P max, were significantly correlated with real-world cocaine use. Results indicate that the Cocaine Purchasing Task produces orderly demand curve data, and that these data relate to real-world measures of cocaine use.

  19. Dynamic Vehicle Scheduling for Working Service Network with Dual Demands

    Directory of Open Access Journals (Sweden)

    Bing Li

    2017-01-01

    Full Text Available This study aims to develop some models to aid in making decisions on the combined fleet size and vehicle assignment in working service network where the demands include two types (minimum demands and maximum demands, and vehicles themselves can act like a facility to provide services when they are stationary at one location. This type of problem is named as the dynamic working vehicle scheduling with dual demands (DWVS-DD and formulated as a mixed integer programming (MIP. Instead of a large integer program, the problem is decomposed into small local problems that are guided by preset control parameters. The approach for preset control parameters is given. By introducing them into the MIP formulation, the model is reformulated as a piecewise form. Further, a piecewise method by updating preset control parameters is proposed for solving the reformulated model. Numerical experiments show that the proposed method produces better solution within reasonable computing time.

  20. Collusion and the elasticity of demand

    OpenAIRE

    David Collie

    2004-01-01

    The analysis of collusion in infinitely repeated Cournot oligopoly games has generally assumed that demand is linear, but this note uses constant-elasticity demand functions to investigate how the elasticity of demand affects the sustainability of collusion.

  1. EIA projections of coal supply and demand

    International Nuclear Information System (INIS)

    Klein, D.E.

    1989-01-01

    Contents of this report include: EIA projections of coal supply and demand which covers forecasted coal supply and transportation, forecasted coal demand by consuming sector, and forecasted coal demand by the electric utility sector; and policy discussion

  2. Coming to grips with challenging behaviour: a cluster randomised controlled trial on the effects of a new care programme for challenging behaviour on burnout, job satisfaction and job demands of care staff on dementia special care units

    NARCIS (Netherlands)

    Zwijsen, S.A.; Gerritsen, D.L.; Eefsting, J.A.; Smalbrugge, M.; Hertogh, C.M.P.M.; Pot, A.M.

    2015-01-01

    Background: Caring for people with dementia in dementia special care units is a demanding job. Challenging behaviour is one of the factors influencing the job satisfaction and burnout of care staff. A care programme for the challenging behaviour of nursing home residents with dementia might, next to

  3. Coming to grips with challenging behaviour: a cluster randomised controlled trial on the effects of a new care programme for challenging behaviour on burnout, job satisfaction and job demands of care staff on dementia special care units

    NARCIS (Netherlands)

    Zwijsen, S.A.; Gerritsen, D.L.; Eefsting, J.A.; Smalbrugge, M.; Hertogh, C.M.; Pot, A.M.

    2015-01-01

    BACKGROUND: Caring for people with dementia in dementia special care units is a demanding job. Challenging behaviour is one of the factors influencing the job satisfaction and burnout of care staff. A care programme for the challenging behaviour of nursing home residents with dementia might, next to

  4. Consumer Demand for Major Foods in Egypt

    OpenAIRE

    Basem Fayaad; Stanley R. Johnson; Mohamed El-Khishin

    1995-01-01

    This study provides information on the structure of the consumer demand for major foods in Egypt. The information is in the form of key parameters for consumer demand systems. The modern theory of consumer behavior is the basis for estimating systems of demand equations. These systems yield estimates of own- and cross-price elasticities. The Linear Almost Ideal Demand System (LAIDS) model is applied in estimating a system of demand equations for food commodities. A full demand matrix results ...

  5. Intercity Travel Demand Analysis Model

    Directory of Open Access Journals (Sweden)

    Ming Lu

    2014-01-01

    Full Text Available It is well known that intercity travel is an important component of travel demand which belongs to short distance corridor travel. The conventional four-step method is no longer suitable for short distance corridor travel demand analysis for the time spent on urban traffic has a great impact on traveler's main mode choice. To solve this problem, the author studied the existing intercity travel demand analysis model, then improved it based on the study, and finally established a combined model of main mode choice and access mode choice. At last, an integrated multilevel nested logit model structure system was built. The model system includes trip generation, destination choice, and mode-route choice based on multinomial logit model, and it achieved linkage and feedback of each part through logsum variable. This model was applied in Shenzhen intercity railway passenger demand forecast in 2010 as a case study. As a result, the forecast results were consistent with the actuality. The model's correctness and feasibility were verified.

  6. Uranium. Resources, production and demand

    International Nuclear Information System (INIS)

    1997-01-01

    The events characterising the world uranium market in the last several years illustrate the persistent uncertainly faced by uranium producers and consumers worldwide. With world nuclear capacity expanding and uranium production satisfying only about 60 per cent of demand, uranium stockpiles continue to be depleted at a high rate. The uncertainty related to the remaining levels of world uranium stockpiles and to the amount of surplus defence material that will be entering the market makes it difficult to determine when a closer balance between uranium supply and demand will be reached. Information in this report provides insights into changes expected in uranium supply and demand until well into the next century. The 'Red Book', jointly prepared by the OECD Nuclear Energy Agency and the International Atomic Energy Agency, is the foremost reference on uranium. This world report is based on official information from 59 countries and includes compilations of statistics on resources, exploration, production and demand as of 1 January 1997. It provides substantial new information from all of the major uranium producing centres in Africa, Australia, Eastern Europe, North America and the New Independent States, including the first-ever official reports on uranium production in Estonia, Mongolia, the Russian Federation and Uzbekistan. It also contains an international expert analysis of industry statistics and worldwide projections of nuclear energy growth, uranium requirements and uranium supply

  7. The moral demands of affluence

    DEFF Research Database (Denmark)

    Sønderholm, Jørn

    2015-01-01

    In 2004, Garrett Cullity made a significant contribution to the literature on what the world’s relatively affluent owe to the world’s relatively poor through the publishing of The Moral Demands of Affluence. In this discussion note, I draw attention to a logical problem in Cullity’s master argument...

  8. Future butanes supply/demand

    International Nuclear Information System (INIS)

    Whitley, S.C.

    1992-01-01

    This paper graphically depicts, through in-depth supply/demand analysis, how environmental regulations can be both bad and good for an industry. In the case of n-butane, the Environmental Protection Agency (EPA) summertime gasoline volatility regulations are a culprit - threatening to ultimately destroy refinery demand for the product as a gasoline blendstock. Waiting in the wings are environmental regulations that should eventually prove to be n-butane's savior. The regulations referred to here are the Clean Air Act (CAA) of 1990's mandate for motor fuel oxygenates. The negative impact of gasoline volatility regulations on U.S. n-butane demand and the positive impact that should come from the use of n-butane as a MTBE precursor are covered. Many variables exist which make studying the effects of these environmental regulations very difficult. Over the past three years RPC Group has conducted numerous studies on n-butane supply/demand, as impacted by both EPA gasoline volatility and fuel oxygenate regulations

  9. Consumer surplus and CES demand

    NARCIS (Netherlands)

    ten Raa, Thijs

    2015-01-01

    This article presents the consumer surplus formula for constant elasticity of substitution (CES) demands. The formula is used to compare the monopoly and optimum provisions of product variety. It is shown that a monopolist under-provides variety. This result is contrasted with Lambertini’s analysis

  10. Projecting Electricity Demand in 2050

    Energy Technology Data Exchange (ETDEWEB)

    Hostick, Donna J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Belzer, David B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hadley, Stanton W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Markel, Tony [National Renewable Energy Lab. (NREL), Golden, CO (United States); Marnay, Chris [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kintner-Meyer, Michael C. W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-07-01

    This paper describes the development of end-use electricity projections and load curves that were developed for the Renewable Electricity (RE) Futures Study (hereafter RE Futures), which explored the prospect of higher percentages (30% - 90%) of total electricity generation that could be supplied by renewable sources in the United States. As input to RE Futures, two projections of electricity demand were produced representing reasonable upper and lower bounds of electricity demand out to 2050. The electric sector models used in RE Futures required underlying load profiles, so RE Futures also produced load profile data in two formats: 8760 hourly data for the year 2050 for the GridView model, and in 2-year increments for 17 time slices as input to the Regional Energy Deployment System (ReEDS) model. The process for developing demand projections and load profiles involved three steps: discussion regarding the scenario approach and general assumptions, literature reviews to determine readily available data, and development of the demand curves and load profiles.

  11. The Cognitive Demands of Writing

    NARCIS (Netherlands)

    Torrance, Mark; Jeffery, Gaynor

    1999-01-01

    Writing is a complex activity that places demands on cognitive resources. This volume presents original theory and research exploring the ways in which the sub-components of the writing process (generating and organizing content, producing grammatical sentences, etc.) differ in their cognitive

  12. Price and income elasticities of demand for alcoholic beverages.

    Science.gov (United States)

    Ornstein, S I; Levy, D

    1983-01-01

    Estimating the demand for alcoholic beverages represents a difficult statistical problem. A number of studies have attempted to estimate the demand for beer, wine, distilled spirits, or total alcohol consumption. The results vary widely according to country of study, data used, and model and statistical technique. For the United States, most studies find the demand for beer to be relatively price inelastic, at around -0.3. The demand for distilled spirits appears to be unitary price elasticity or somewhat greater, around -1.5. The evidence on wine is too sketchy to draw any conclusions. There is no strong evidence of substitutability among beer, wine, and distilled spirits based on econometric models, nor evidence that advertising plays a strong role in the aggregate demand for beer, wine, or distilled spirits. The main policy implication is that price increases to control consumption will have a stronger impact on the consumption of distilled spirits than on beer.

  13. Policy packages to achieve demand reduction

    International Nuclear Information System (INIS)

    Boardman, Brenda

    2005-01-01

    In many sectors and many countries, energy demand is still increasing, despite decades of policies to reduce demand. Controlling climate change is becoming more urgent, so there is a need to devise policies that will, virtually, guarantee demand reduction. This has to come from policy, at least in the UK, as the conditions do not exist, yet, when the consumers will 'pull' the market for energy efficiency or the manufacturers will use technological development to 'push' it. That virtuous circle has to be created by a mixture of consumer education and restrictions on manufacturers (for instance, permission to manufacture). The wider policy options include higher prices for energy and stronger product policies. An assessment of the effectiveness of different policy packages indicates some guiding principles, for instance that improved product policy must precede higher prices, otherwise consumers are unable to react effectively to price rises. The evidence will be assessed about the ways in which national and EU policies can either reinforce, duplicate or undermine each other. Another area of examination will be timescales: what is the time lag between the implementation of a policy (whether prices or product based) and the level of maximum reductions. In addition, the emphasis given to factors such as equity, raising investment funds and speed of delivery also influence policy design and the extent to which absolute carbon reductions can be expected

  14. Enabling technologies for industrial energy demand management

    International Nuclear Information System (INIS)

    Dyer, Caroline H.; Hammond, Geoffrey P.; Jones, Craig I.; McKenna, Russell C.

    2008-01-01

    This state-of-science review sets out to provide an indicative assessment of enabling technologies for reducing UK industrial energy demand and carbon emissions to 2050. In the short term, i.e. the period that will rely on current or existing technologies, the road map and priorities are clear. A variety of available technologies will lead to energy demand reduction in industrial processes, boiler operation, compressed air usage, electric motor efficiency, heating and lighting, and ancillary uses such as transport. The prospects for the commercial exploitation of innovative technologies by the middle of the 21st century are more speculative. Emphasis is therefore placed on the range of technology assessment methods that are likely to provide policy makers with a guide to progress in the development of high-temperature processes, improved materials, process integration and intensification, and improved industrial process control and monitoring. Key among the appraisal methods applicable to the energy sector is thermodynamic analysis, making use of energy, exergy and 'exergoeconomic' techniques. Technical and economic barriers will limit the improvement potential to perhaps a 30% cut in industrial energy use, which would make a significant contribution to reducing energy demand and carbon emissions in UK industry. Non-technological drivers for, and barriers to, the take-up of innovative, low-carbon energy technologies for industry are also outlined

  15. Addressing Energy Demand through Demand Response. International Experiences and Practices

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ghatikar, Girish [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ni, Chun Chun [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dudley, Junqiao [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Martin, Phil [Enernoc, Inc., Boston, MA (United States); Wikler, Greg

    2012-06-01

    Demand response (DR) is a load management tool which provides a cost-effective alternative to traditional supply-side solutions to address the growing demand during times of peak electrical load. According to the US Department of Energy (DOE), demand response reflects “changes in electric usage by end-use customers from their normal consumption patterns in response to changes in the price of electricity over time, or to incentive payments designed to induce lower electricity use at times of high wholesale market prices or when system reliability is jeopardized.” 1 The California Energy Commission (CEC) defines DR as “a reduction in customers’ electricity consumption over a given time interval relative to what would otherwise occur in response to a price signal, other financial incentives, or a reliability signal.” 2 This latter definition is perhaps most reflective of how DR is understood and implemented today in countries such as the US, Canada, and Australia where DR is primarily a dispatchable resource responding to signals from utilities, grid operators, and/or load aggregators (or DR providers).

  16. The demand for consumer health information.

    Science.gov (United States)

    Wagner, T H; Hu, T W; Hibbard, J H

    2001-11-01

    Using data from an evaluation of a community-wide informational intervention, we modeled the demand for medical reference books, telephone advice nurses, and computers for health information. Data were gathered from random household surveys in Boise, ID (experimental site), Billings, MT, and Eugene, OR (control sites). Conditional difference-in-differences show that the intervention increased the use of medical reference books, advice nurses, and computers for health information by approximately 15, 6, and 4%. respectively. The results also suggest that the intervention was associated with a decreased reliance on health professionals for information.

  17. Demand chain management - The evolution

    Directory of Open Access Journals (Sweden)

    D Ericsson

    2011-06-01

    Full Text Available The concepts of Supply Chain Management (SCM and Demand Chain Management (DCM are among the new and debated topics concerning logistics in the literature. The question considered in this paper is: “Are these concepts needed or will they just add to the confusion?” Lasting business concepts have always evolved in close interaction between business and academia. Different approaches start out in business and they are then, more or less si- multaneously, aligned, integrated, systemised and structured in academia. In this way a terminology (or language is provided that helps in further diffusion of the concepts. There is a lack of consensus on the definition of the concept of SCM. This may be one of the major reasons for the difficulty in advancing the science and measuring the results of implementation in business. Relationships in SCM span from rather loose coalitions to highly structured virtual network integrations. DCM is a highly organised chain in which the key is mutual interdependence and partnership. The purpose is to create a distinctive competence for the chain as a whole that helps to identify and satisfy customer needs and wishes. The classical research concerning vertical marketing systems is very helpful in systemising the rather unstructured discussions in current SCM research. The trend lies in increasing competition between channels rather than between companies, which in turn leads to the creation of channels with a high degree of partnership and mutual interdependence between members. These types of channels are known as organised vertical marketing systems in the classic marketing channel research. The behaviour in these types of channels, as well as the formal and informal structures, roles in the network, power and dependence relations, etc. are well covered topics in the literature. The concept of vertical marketing systems lies behind the definition of demand chains and demand chain management proposed in this paper. A

  18. DataBase on Demand

    International Nuclear Information System (INIS)

    Aparicio, R Gaspar; Gomez, D; Wojcik, D; Coz, I Coterillo

    2012-01-01

    At CERN a number of key database applications are running on user-managed MySQL database services. The database on demand project was born out of an idea to provide the CERN user community with an environment to develop and run database services outside of the actual centralised Oracle based database services. The Database on Demand (DBoD) empowers the user to perform certain actions that had been traditionally done by database administrators, DBA's, providing an enterprise platform for database applications. It also allows the CERN user community to run different database engines, e.g. presently open community version of MySQL and single instance Oracle database server. This article describes a technology approach to face this challenge, a service level agreement, the SLA that the project provides, and an evolution of possible scenarios.

  19. Uranium Resources, production and demand

    International Nuclear Information System (INIS)

    1988-01-01

    Periodic assessments of world uranium supply and demand have been conducted by the OECD Nuclear Energy Agency (NEA) and the International Atomic Energy Agency (IAEA) since the mid 1960s. Published every two years, the report URANIUM RESOURCES, PRODUCTION AND DEMAND, commonly referred to as the RED BOOK, has become an essential reference document for nuclear planners and policy makers in the international nuclear community. The latest Red Book, published in 1988, was based on data collected mainly in early 1987. Most of the data for 1987 were therefore provisional. The STATISTICAL UPDATE 1988 provides updated 1987 data collected in 1988 and provisional data for 1988. The publication, which covers OECD Countries and gives Secretariat estimates for the rest of the World Outside Centrally Planned Economies (WOCA), is being issued every second year, between publications of more complete Red Books

  20. Enrichment demand boosts SWU prices

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    The enrichment market is picking up significantly on very brisk demand. US utilities, which normally purchase material nine months to a year ahead of time, are already hitting the market to fill their 1996 requirements. In June, two non-US utilities, one European entity and a US utility bought SWUs, the entity in an off-market deal. But that doesn't tell the whole story. Three other US utilities entered the market during the month. Meanwhile, we count 13 more utilities getting ready to hit the market for more than 4 million SWUs. Why the surge in demand? Utilities, uncertain of the role to be played by the new US Enrichment Corp. and seeking to take advantage of low interest rates, are implementing buy and hold strategies. As a result, the upper end of NUKEM's SWU price range inched up to $78. The lower end dipped to $67 based on the European deal

  1. Strong demand for natural uranium

    International Nuclear Information System (INIS)

    Kalinowski, P.

    1975-01-01

    The Deutsches Atomforum and the task group 'fuel elements' of the Kerntechnische Gesellschaft had organized an international two-day symposium in Mainz on natural uranium supply which was attended by 250 experts from 20 countries. The four main themes were: Demand for natural uranium, uranium deposits and uranium production, attitude of the uranium producing countries, and energy policy of the industrial nations. (orig./AK) [de

  2. Alcohol demand and risk preference.

    Science.gov (United States)

    Dave, Dhaval; Saffer, Henry

    2008-12-01

    Both economists and psychologists have studied the concept of risk preference. Economists categorize individuals as more or less risk-tolerant based on the marginal utility of income. Psychologists categorize individuals' propensity towards risk based on harm avoidance, novelty seeking and reward dependence traits. The two concepts of risk are related, although the instruments used for empirical measurement are quite different. Psychologists have found risk preference to be an important determinant of alcohol consumption; however economists have not included risk preference in studies of alcohol demand. This is the first study to examine the effect of risk preference on alcohol consumption in the context of a demand function. The specifications employ multiple waves from the Panel Study of Income Dynamics (PSID) and the Health and Retirement Study (HRS), which permit the estimation of age-specific models based on nationally representative samples. Both of these data sets include a unique and consistent survey instrument designed to directly measure risk preference in accordance with the economist's definition. This study estimates the direct impact of risk preference on alcohol demand and also explores how risk preference affects the price elasticity of demand. The empirical results indicate that risk preference has a significant negative effect on alcohol consumption, with the prevalence and consumption among risk-tolerant individuals being 6-8% higher. Furthermore, the tax elasticity is similar across both risk-averse and risk-tolerant individuals. This suggests that tax policies are as equally effective in deterring alcohol consumption among those who have a higher versus a lower propensity for alcohol use.

  3. Millennium bim managing growing demand

    OpenAIRE

    Lopes, Francisca Barbosa Malpique de Paiva

    2014-01-01

    Millennium bim, the Mozambican operation of Millennium bcp group, was the Company selected to serve as background for the development of a teaching case in Marketing. This case is followed by a teaching note, and is intended to be used as a pedagogical tool in undergraduate and/or graduate programs. Even though Mozambique is still characterized by high financial exclusion, the number of people entering within the banking industry has been growing at a fast pace. Actually, the demand for fi...

  4. Demand for healthcare in India

    Directory of Open Access Journals (Sweden)

    Brijesh C. Purohit

    2013-03-01

    Full Text Available In a developing country like India, allocation of scarce fiscal resources has to be based on a clear understanding of how investments in the heath sector are going to affect demand. Three aspects like overall healthcare demand, consumer decisions to use public and/or private care and role of price/quality influencing poor/rich consumer’s decisions are critical to assessing the equity implications of alternative policies. Our paper addresses these aspects through examining the pattern of healthcare demand in India. Data from the National Family Health Survey are used to model the healthcare choices that individuals make. We consider what these behavioral characteristics imply for public policy. This analysis aims to study disparities between rural and urban areas from all throughout India to five Indian states representing three levels of per capita incomes (all-India average, rich and poor. Results evidence that healthcare demand both in rural and urban areas is a commodity emerging as an essential need. Choices between public or private provider are guided by income and quality variables mainly with regard to public healthcare denoting thus a situation of very limited alternatives in terms of availing private providers. These results emphasize that existing public healthcare facilities do not serve the objective of providing care to the poor in a satisfactory manner in rural areas. Thus, any financing strategy to improve health system and reduce disparities across rich-poor states and rural-urban areas should also take into account not only overcoming inadequacy but also inefficiency in allocation and utilization of healthcare inputs.

  5. Uranium resources, production and demand

    International Nuclear Information System (INIS)

    1988-01-01

    Nuclear power-generating capacity will continue to expand, albeit at a slower pace than during the past fifteen years. This expansion must be matched by an adequately increasing supply of uranium. This report compares uranium supply and demand data in free market countries with the nuclear industry's natural uranium requirements up to the year 2000. It also reviews the status of uranium exploration, resources and production in 46 countries

  6. The economics of uranium demand

    International Nuclear Information System (INIS)

    Owen, A.D.

    1983-01-01

    The major characteristics of the demand for uranium are identified, and a number of factors which determine the actual level of uranium requirements of the nuclear power industry are discussed. Since the role of inventories is central to the process of short-term price formation, by comparing projections of uranium production and apparent consumption, the relative level of total inventories is calculated and an assessment is made of its likely impact on the uranium market during the 1980s. (author)

  7. Forecasting Croatian inbound tourism demand

    OpenAIRE

    Tica, Josip; Kožić, Ivan

    2015-01-01

    The aim of this paper is to present a forecasting model for the overnight stays of foreign tourists in Croatia. Tourism is one of the most important parts of the Croatian economy. It is particularly important in the context of the services sector. Regular and significant surpluses and the consumption of foreign guests are an important element of budget revenues, especially VAT. The ability to forecast the development of inbound tourism demand in a timely manner is crucial for both business...

  8. Optimal Advertising with Stochastic Demand

    OpenAIRE

    George E. Monahan

    1983-01-01

    A stochastic, sequential model is developed to determine optimal advertising expenditures as a function of product maturity and past advertising. Random demand for the product depends upon an aggregate measure of current and past advertising called "goodwill," and the position of the product in its life cycle measured by sales-to-date. Conditions on the parameters of the model are established that insure that it is optimal to advertise less as the product matures. Additional characteristics o...

  9. Demand, Energy, and Power Factor

    Science.gov (United States)

    1994-08-01

    POWER FACTOR DEFINITION I Basically , power factor (pf) is a measure of how effectively the plant uses the electricity it purchases from the utility. It...not be made available by the plant. U 24 This video is relatively short, less than fifteen-minutes, and covers the basics on demand, block extenders... ratemaking methodology and test period as used in determining the NC-RS rates. Pending final decision by the FERC, the Federal Government would pay a rate as

  10. World gas supply-demand

    International Nuclear Information System (INIS)

    Rushby, I.L.

    1996-01-01

    The rapid growth in demand for natural gas from a global perspective is documented in this paper. Low prices compared to other fuels and a return to normal winter temperatures is argued to be the cause of this increase in consumption. Natural gas production and prices for 1995 are discussed and forecasts made for future years, in particular the prospects for LNG in Asia. Data on energy growth and gas specific information in world markets are included. (UK)

  11. Automation of energy demand forecasting

    Science.gov (United States)

    Siddique, Sanzad

    Automation of energy demand forecasting saves time and effort by searching automatically for an appropriate model in a candidate model space without manual intervention. This thesis introduces a search-based approach that improves the performance of the model searching process for econometrics models. Further improvements in the accuracy of the energy demand forecasting are achieved by integrating nonlinear transformations within the models. This thesis introduces machine learning techniques that are capable of modeling such nonlinearity. Algorithms for learning domain knowledge from time series data using the machine learning methods are also presented. The novel search based approach and the machine learning models are tested with synthetic data as well as with natural gas and electricity demand signals. Experimental results show that the model searching technique is capable of finding an appropriate forecasting model. Further experimental results demonstrate an improved forecasting accuracy achieved by using the novel machine learning techniques introduced in this thesis. This thesis presents an analysis of how the machine learning techniques learn domain knowledge. The learned domain knowledge is used to improve the forecast accuracy.

  12. Energy demand and population change.

    Science.gov (United States)

    Allen, E L; Edmonds, J A

    1981-09-01

    During the post World War 2 years energy consumption has grown 136% while population grew about 51%; per capita consumption of energy expanded, therefore, about 60%. For a given population size, demographic changes mean an increase in energy needs; for instance the larger the group of retirement age people, the smaller their energy needs than are those for a younger group. Estimates indicate that by the year 2000 the energy impact will be toward higher per capita consumption with 60% of the population in the 19-61 age group of workers. Rising female labor force participation will increase the working group even more; it has also been found that income and energy grow at a proportional rate. The authors predict that gasoline consumption within the US will continue to rise with availability considering the larger number of female drivers and higher per capita incomes. The flow of illegal aliens (750,000/year) will have a major impact on income and will use greater amounts of energy than can be expected. A demographic change which will lower energy demands will be the slowdown of the rate of household formation caused by the falling number of young adults. The response of energy demand to price changes is small and slow but incomes play a larger role as does the number of personal automobiles and social changes affecting household formation. Households, commercial space, transportation, and industry are part of every demand analysis and population projections play a major role in determining these factors.

  13. Demand for radiotherapy in Spain.

    Science.gov (United States)

    Rodríguez, A; Borrás, J M; López-Torrecilla, J; Algara, M; Palacios-Eito, A; Gómez-Caamaño, A; Olay, L; Lara, P C

    2017-02-01

    Assessing the demand for radiotherapy in Spain based on existing evidence to estimate the human resources and equipment needed so that every person in Spain has access to high-quality radiotherapy when they need it. We used data from the European Cancer Observatory on the estimated incidence of cancer in Spain in 2012, along with the evidence-based indications for radiotherapy developed by the Australian CCORE project, to obtain an optimal radiotherapy utilisation proportion (OUP) for each tumour. About 50.5 % of new cancers in Spain require radiotherapy at least once over the course of the disease. Additional demand for these services comes from reradiation therapy and non-melanoma skin cancer. Approximately, 25-30 % of cancer patients with an indication for radiotherapy do not receive it due to factors that include access, patient preference, familiarity with the treatment among physicians, and especially resource shortages, all of which contribute to its underutilisation. Radiotherapy is underused in Spain. The increasing incidence of cancer expected over the next decade and the greater frequency of reradiations necessitate the incorporation of radiotherapy demand into need-based calculations for cancer services planning.

  14. Demands from the school inclusion

    Directory of Open Access Journals (Sweden)

    Selma Norberto Matos

    2014-04-01

    Full Text Available From the implementation of public policies on school inclusion, mainly those directed to the target audience of special education, the number of students with special educational needs in common classes has increased. This fact has helped to compose the picture in schools where the limitations and contradictions of the Brazilian educational system have appeared. Educational actors and authors are challenged to build knowledge able of responding to demands of daily school, concerning living and learning in diversity. Whereas this inclusive process is new in the schools, the study aimed to analyze the demands of teachers from the school inclusion. The research was qualitative and exploratory, and six teachers, their students with special educational needs and three professionals in the Nucleus of Inclusive Education from the Municipal Department of Education took in it. Technique of participant observation, field diary, semi-structured interview and questionnaire were used for data collection, while analysis of content was used for discussion of the data. The results indicate that there are achievements and contradictions in the reality of schools that themselves propose inclusive; advances and limitations resulting from the municipal politics; that the model of performance of the group of special education, in the context analyzed, may be revised or expanded; and that the teachers has demands with regard to public policy, training, and the psychologist.

  15. PREDICTING DEMAND FOR COTTON YARNS

    Directory of Open Access Journals (Sweden)

    SALAS-MOLINA Francisco

    2017-05-01

    Full Text Available Predicting demand for fashion products is crucial for textile manufacturers. In an attempt to both avoid out-of-stocks and minimize holding costs, different forecasting techniques are used by production managers. Both linear and non-linear time-series analysis techniques are suitable options for forecasting purposes. However, demand for fashion products presents a number of particular characteristics such as short life-cycles, short selling seasons, high impulse purchasing, high volatility, low predictability, tremendous product variety and a high number of stock-keeping-units. In this paper, we focus on predicting demand for cotton yarns using a non-linear forecasting technique that has been fruitfully used in many areas, namely, random forests. To this end, we first identify a number of explanatory variables to be used as a key input to forecasting using random forests. We consider explanatory variables usually labeled either as causal variables, when some correlation is expected between them and the forecasted variable, or as time-series features, when extracted from time-related attributes such as seasonality. Next, we evaluate the predictive power of each variable by means of out-of-sample accuracy measurement. We experiment on a real data set from a textile company in Spain. The numerical results show that simple time-series features present more predictive ability than other more sophisticated explanatory variables.

  16. Home Network Technologies and Automating Demand Response

    Energy Technology Data Exchange (ETDEWEB)

    McParland, Charles

    2009-12-01

    Over the past several years, interest in large-scale control of peak energy demand and total consumption has increased. While motivated by a number of factors, this interest has primarily been spurred on the demand side by the increasing cost of energy and, on the supply side by the limited ability of utilities to build sufficient electricity generation capacity to meet unrestrained future demand. To address peak electricity use Demand Response (DR) systems are being proposed to motivate reductions in electricity use through the use of price incentives. DR systems are also be design to shift or curtail energy demand at critical times when the generation, transmission, and distribution systems (i.e. the 'grid') are threatened with instabilities. To be effectively deployed on a large-scale, these proposed DR systems need to be automated. Automation will require robust and efficient data communications infrastructures across geographically dispersed markets. The present availability of widespread Internet connectivity and inexpensive, reliable computing hardware combined with the growing confidence in the capabilities of distributed, application-level communications protocols suggests that now is the time for designing and deploying practical systems. Centralized computer systems that are capable of providing continuous signals to automate customers reduction of power demand, are known as Demand Response Automation Servers (DRAS). The deployment of prototype DRAS systems has already begun - with most initial deployments targeting large commercial and industrial (C & I) customers. An examination of the current overall energy consumption by economic sector shows that the C & I market is responsible for roughly half of all energy consumption in the US. On a per customer basis, large C & I customers clearly have the most to offer - and to gain - by participating in DR programs to reduce peak demand. And, by concentrating on a small number of relatively

  17. 46 CFR 169.689 - Demand loads.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Demand loads. 169.689 Section 169.689 Shipping COAST... Electrical Electrical Installations on Vessels of 100 Gross Tons and Over § 169.689 Demand loads. Demand loads must meet § 111.60-7 of this chapter except that smaller demand loads for motor feeders are...

  18. Market Design for Rapid Demand Response - The Case of Kenya

    OpenAIRE

    Kurt Nielsen; Tseganesh Wubale Tamirat

    2014-01-01

    We suggest a market design for rapid demand response in electricity markets. The solution consists of remotely controlled switches, meters, forecasting models as well as a flexible auction market to set prices and select endusers job by job. The auction market motivates truth-telling and makes it simple to involve the endusers in advance and to activate demand response immediately. The collective solution is analyzed and economic simulations are conducted for the case of Kenya. Kenya has been...

  19. Demand-Driven Success: Designing Your PDA Experiment

    OpenAIRE

    Hillen, Charles; Johnson-Grau, Glenn

    2012-01-01

    Initiating demand-driving acquisition is daunting. Implications for developing a sustainable budget model, choosing a vendor, controlling metadata, monitoring purchases and developing invoice workflows are significant areas of concern that require determinative planning. From mid-February through August 2011, Loyola Marymount University conducted a pilot using demand-driven acquisition; the result of this successful experiment was the library’s decision to fully integrate this purchasing mode...

  20. Demand for food products in Finland: A demand system approach

    Directory of Open Access Journals (Sweden)

    Ilkka P. Laurila

    1994-07-01

    Full Text Available The study was concerned with the estimation of food-demand parameters in a system context. The patterns of food consumption in Finland were presented over the period 1950-1991, and a complete demand system of food expenditures was estimated. Price and expenditure elasticities of demand were derived, and the results were used to obtain projections on future consumption. While the real expenditure on food has increased, the budget share of food has decreased. In the early 19505, combined Food-at-Home and Food-away-from-Home corresponded to about 40% of consumers’ total expenditure. In 1991 the share was 28%. There was a shift to meals eaten outside the home. While the budget share of Food-away-from-Home increased from 3% to 7% over the observation period, Food-at-Home fell from 37% to 21%, and Food-at-Home excluding Alcoholic Drinks fell from 34% to 16%. Within Food-at-Home, the budget shares of the broad aggregate groups, Animalia (food from animal sources, Beverages, and Vegetablia (food from vegetable sources, remained about the same over the four decades, while structural change took place within the aggregates. Within Animalia, consumption shifted from Dairy Products (other than Fresh Milk to Meat and Fish. Within Beverages, consumption shifted from Fresh Milk and Hot Drinks to Alcoholic Drinks and Soft Drinks. Within Vegetablia, consumption shifted from Flour to Fruits, while the shares of Bread and Cake and Vegetables remained about the same. As the complete demand system, the Almost Ideal Demand System (AIDS was employed. The conventional AIDS was extended by developing a dynamic generalisation of the model and allowing for systematic shifts in structural relationships over time. A four-stage budgeting system was specified, consisting of seven sub-systems (groups, and covering 18 food categories. Tests on parameter restrictions and misspecification tests were used to choose the most preferred model specification for each group. Generally