Operating Strategies for Battery Storage Systems in Low-Voltage Grids to Limit the Feed-In Power of Solar Power Systems Using Fuzzy Control

Germany’s energy turnaround is leading to an increasing integration of photovoltaics (PVs) throughout its distribution grid. To ensure safe grid operation in times of high solar radiation, PV plants must either be throttled back to comply with the feed-in limitation or store a portion of their excess electricity in batteries. This paper presents a grid-optimized operating strategy for PV storage systems based on a Fuzzy Logic Controller that reduces peak feed-in and thus also PV curtailment losses. The Fuzzy Logic Controller uses data on PV power surplus and battery charge level as input variables. To obtain good results, the set of numerical parameters of the membership functions is enhanced by evolutionary programming.The energetic assessment shows that even small electrical storage capacities (<<5?kWh) reduce curtailment losses considerably when using the grid-optimized operating strategy. The economic assessment shows that, in 2016, investments in PV storage systems with large PV plants and small batteries have small (positive) Internal Rates of Return. The system efficiency of the battery storage has a small impact on the profitability of PV storage systems, whereas the cycle stability and the electricity purchase price have a large impact. Moreover, there is an economic benefit for plant operators to switch from the simple to the grid-optimized operating strategy. Solar forecast inaccuracies and variations in load and generation profiles have a negligible impact on the performance of the control algorithm.     

The role of CEO relative standing in acquisition behavior and CEO pay

In this study, we develop and test a theory of CEO relative pay standing. Specifically, we propose that CEOs with negative relative pay standing status (underpaid relative to comparison CEOs) will engage in acquisition activity, as a self‐interested means of attempting to realign their pay with that of their peers. We further propose that, when CEOs with negative relative pay standing acquire, they will tend to finance those acquisitions more heavily with stock than cash, to mitigate the risk associated with those deals. Finally, we argue that acquisition activity will partially mediate the influence of CEO negative relative pay standing on subsequent CEO compensation increases; however, that pay growth will come primarily in the form of long‐term incentive pay. Our results support our predictions. Copyright © 2014 John Wiley & Sons, Ltd.     

The Health Consequences of Adverse Labor Market Events: Evidence from Panel Data

This study investigates the associations between self‐assessed adverse labor market events (experiencing problems with coworkers, employment changes, financial strain) and health. Longitudinal data are obtained from the National Epidemiological Survey of Alcohol and Related Conditions. Our findings suggest problems with coworkers, employment changes, and financial strain are associated, respectively, with a 3.1 percent (3.3 percent), 0.9 percent (0.2 percent), and 4.5 percent (5.1 percent) reduction in mental health among men (women). Associations are smaller in magnitude and less significant for physical health.     

Technology‐push,market‐demand and the missing safety‐pull: a case study of American Airlines Flight 587

Through a critical case study of the crash of American Airlines Flight 587, this paper draws upon ‘the Social Shaping of Technology’ (SST) approach to offer a reconceptualisation of the technology‐push and market‐demand model for High‐Reliably Organisations (HROs), providing support for a third factor, called here a ‘safety‐pull’. A safety‐pull is defined as organisationally supported reflexivity in which technology innovators and frontline operators collaborate to consider the potential implications of adopting new technologies in HROs and the complex ways this change may impact human operators' work performance, often in risky and unanticipated ways. In contrast to accidents occurring solely as the result of individual operator error, analysing the safety‐pull provides a way to tease out the wide range of factors that can contribute to HRO failures and offers a new SST perspective through which to examine high‐risk operations.     

Knowledge exchange in networked organizations: does place matter?

While many studies of knowledge exchange have been undertaken in private and service organizations, government and R&D enterprises, few have studied scientific inter‐organizational collaborations. Furthermore, in the literature on international networks there has been a tendency to assume that knowledge exchange will be inevitably enhanced by global dispersion. Two linked dynamics deserving further study are the role of geographic proximity and the role of information and communication technologies in facilitating knowledge flow across international networks. Studies of intra‐ and inter‐firm knowledge transfer, managerial work values and cultural norms all point to China as being a fascinating counterpoint for the way knowledge exchange might occur in Europe. So in this study of the ATLAS collaboration, a ‘big science’ global network of 3,500 physicists, we explore the perceptions of two subgroups: UK physicists working in Europe and Chinese scientists based in Beijing and HeFei. Findings from 24 interviews and non‐participant observation reveal that face‐to‐face working at European Organization for Nuclear Research (Geneva) is not without its difficulties, but for a variety of sociocultural reasons, it is primarily the Chinese scientists who perceive themselves to be inhibited from full participation in effective knowledge exchange.     

TECHNICAL NOTE : THE VARIABLE FINANCIAL INDICATOR IRR AND THE CONSTANT ECONOMIC INDICATOR NPV

The IRR (internal rate of return) and the NPV (net present value) are the two most common and important indicators in investment decisions. These two indicators, however, have intrinsic differences between one another. The IRR is a financial indicator and the NPV an economic indicator of a capital investment. The former gives the private investor's point of view and the latter the society's point of view. The value of ERR varies with the change of Financial arrangement of an investment. The NPV, however, does not but remains constant no matter how the financial arrangement changes. This paper uses an illustrative example to show their intrinsic differences and then describes a mathematical proof to substantiate the different natures of IRR and NPV.     

TECHNICAL NOTE A MODIFIED EOQ MODEL WITH TEMPORARY SALE PRICE DERIVED WITHOUT DERIVATIVES

Most previous works applied differential calculus to derive optimal solutions for economic ordering policy. The formulations are suggested in this short note to show that optimal solutions can be derived algebraically without using differential calculus to treat the EOQ model with a temporary sale price.