Modeling electricity storage to address challenges and opportunities of its applications for smart grids requires inter-temporal equalities to keep track of energy content over time. Prevalently, these constraints present crucial modeling elements as to what extent energy storage applications can enhance future electric power systems' sustainability, reliability, and efficiency. This paper presents a novel and improved mixed-integer linear problem (MILP) formulation for energy storage of plug-in (hybrid) electric vehicles (PEVs) for reserves in power system models. It is based on insights from the field of System Dynamics, in which complex interactions between different elements are studied by means of feedback loops as well as stocks, flows and co-flows. Generalized to a multi-bus system, this formulation includes improvements in the energy balance and surpasses shortcomings in the way existing literature deals with reserve constraints. Tested on the IEEE 14-bus system with realistic PEV mobility patterns, the deterministic results show changes in the scheduling of the units, often referred to as unit commitment (UC).
Standaert, Willem; Muylle, Steve; Basu, Amit (2016)
Telepresence is a technology that has emerged as a promising mode for conducting business meetings with distributed participants, since it enables an immersive lifelike experience. However, telepresence meetings are substantially more expensive than audio- and video-conferencing meetings. This paper examines the justification of using telepresence for meetings. Based on an extensive literature review, two research questions about the effectiveness of telepresence for achieving meeting objectives are formulated. These are then addressed in an empirical study consisting of two phases, conducted in a large multinational corporation in which telepresence is widely used. In Phase 1, a list of meeting objectives is compiled. In Phase 2, the effectiveness of telepresence is analyzed relative to audio-conferencing, video-conferencing, and face-to-face for these objectives, based on input from 392 meeting organizers. The results of the analysis indicate that although the effectiveness of telepresence is higher than the effectiveness of audio- and video-conferencing for several meeting objectives, it is not significantly different from the effectiveness of face-to-face for any objective.
The purpose of this paper is to explain why product-centric manufacturers utilize advanced services not as vehicles of transformation, but of reinforcement, to strengthen their established business model logic based on selling products and basic product-related services.
Verleye, Katrien; Gemmel, Paul; Rangarajan, Deva (2016)
Purpose: - The purpose of this paper is to empirically test a theoretical model on how different customer engagement behaviors (CEBs), such as giving feedback and helping other customers, affect the role stress-job strain relationship among frontline employees. Design/methodology/approach: - Drawing from the job demands-resources model, this paper hypothesizes that some CEBs weaken the role stress-job strain relationship among frontline employees, whereas the opposite holds for other CEBs. To test these hypotheses, the study involved a survey among 279 frontline employees in 20 nursing home teams in Belgium. Findings: - The results reveal that the impact of role stress on job strain is stronger when frontline employees notice more helping behaviors among customers and weaker when frontline employees receive more customer feedback or notice that customers spread positive word-of-mouth about the nursing home. Originality/value This research contributes to the customer engagement and frontline employee literature by showing that CEBs can act as both job demands and job resources for frontline employees
In recent years, a variety of novel approaches for fulfilling the important management task of accurately forecasting project duration have been proposed, with many of them based on the earned value management (EVM) methodology. However, these state-of-the-art approaches have often not been adequately tested on a large database, nor has their validity been empirically proven. Therefore, we evaluate the accuracy and timeliness of three promising deterministic techniques and their mutual combinations on a real-life project database. More specifically, two techniques respectively integrate rework and activity sensitivity in EVM time forecasting as extensions, while a third innovatively calculates schedule performance from time-based metrics and is appropriately called earned duration management or EDM(t). The results indicate that all three of the considered techniques are relevant. More concretely, the two EVM extensions exhibit accuracy-enhancing power for different applications, while EDM(t) performs very similar to the best EVM methods and shows potential to improve them.
Learning effects assume that the efficiency of a resource increases with the duration of a task. Although these effects are commonly used in machine scheduling environments, they are rarely used in a project scheduling setting. In this paper, the effect of learning in a project scheduling environment is studied and applied to the discrete time/resource trade-off scheduling problem (DTRTP), where each activity has a fixed work content for which a set of execution modes (duration/resource requirement pairs) can be defined. Computational results emphasize the significant impact of learning effects on the project schedule, measure the margin of error made by ignoring learning and show that timely incorporation of learning effects can lead to significant makespan improvements.
This study focuses on market orientation in family-owned firms. Market orientation is influenced by organizational characteristics and is at the same time a key antecedent of innovation. Since the generation in control largely shapes the family firm’s organization, the authors examine the relationships between the generation in control, market orientation, and innovation. Using regression analysis, the study demonstrates that later generations show a lower level of market-oriented behavior, that the positive relationship between market orientation and innovation is maintained in a family firm sample, and that the generation in control influences innovation through its influence on market orientation.
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