149 research outputs found
Smart grid opportunities and applications in Turkey
No full textA smart grid is a system that uses information and communication technologies to integrate, in an intelligent way, all users connected to the electrical power system considering their behaviour and actions. For this purpose, information about the electrical network, such as the current, the voltage or the power, is gathered together over time so that the behaviour of suppliers and consumers can be observed and automatically coordinated. Smart grids are becoming a significant part in the configuration of future electrical power systems. A lot of research has been done on using smart grids to achieve highly efficient and user-friendly electrical power systems. Many new methods have been introduced to solve the difficulties energy providers face when transforming conventional electrical networks into smart grids. These difficulties include the integration of renewable energy and different grid systems at national and international levels due to changes in frequency, voltage and in the synchronisation mechanism
Electric vehicle charging system model for accurate electricity system planning
No full textS.4053-4059This article presents a novel electric vehicle (EV) charging system model. The model introduces power constraints in the grid-to-battery converter to improve modelling accuracy. Simulation results of the presented model indicate EV charging impact on a low-voltage electricity grid. Even though most of the battery charging load is spread evenly during desired times (e.g. off-peak load during night), power constraints of the EV model result in narrow peak loads. Plug-in EVs bring additional load to the electricity grid. If not managed properly, high EV deployment may lead to unnecessary grid investments due to highpeak currents of EV charging. Rising numbers of grid connected EVs is a challenging task in the future electricity grid planning. Thus an accurate EV charging system model is essential for reliable analysis of EV deployment.12Nr.1
On the Performance of Portable NiMH Batteries of General Use
No full textNiMH batteries are the most used technology of rechargeable batteries sold directly to consumers. Herein, we study the performance of the most common sizes of portable NiMH batteries (AA, AAA, D, C, and 9V). The performance and durability parameters—capacity, charge retention, charge recovery, and endurance in cycles—are measured for these types of batteries, according to the standard IEC 61951-2:2017 NiMH batteries. The purpose of this study is to create a basis for setting minimum performance requirements for the parameters in the European Regulation concerning batteries and waste batteries, EU 2023/1542, Annex III, Part B. Results show that the charging time of 16 h could be reduced to 8 h for verifying the rated capacity. The performance of commercial batteries with regard to charge retention, charge recovery, and endurance in cycles is often found to be 25–30% better than required in the relevant IEC standard. Furthermore, we present a short comparative analysis of an application test (IEC 60086-2:2021 “toy”) for portable NiMH batteries with primary batteries. Such data allow comparing the performance of portable NiMH batteries compared to primary batteries in the application test “toy”
"Market-specific and Currency-specific Risk during the Global Financial Crisis: Evidence from the Interbank Markets in Tokyo and London"
No full textThis paper explores how international money markets reflected credit and liquidity risks during the global financial crisis. After matching the currency denomination, we investigate how the Tokyo Interbank Offered Rate (TIBOR) was synchronized with the London Interbank Offered Rate (LIBOR) denominated in the US dollar and the Japanese yen. Regardless of the currency denomination, TIBOR was highly synchronized with LIBOR in tranquil periods. However, the interbank rates showed substantial deviations in turbulent periods. We find remarkable asymmetric responses in reflecting market-specific and currency-specific risks during the crisis. The regression results suggest that counter-party credit risk increased the difference across the markets, while liquidity risk caused the difference across the currency denominations. They also support the view that a shortage of US dollar as liquidity distorted the international money markets during the crisis. We find that coordinated central bank liquidity provisions were useful in reducing liquidity risk in the US dollar transactions. But their effectiveness was asymmetric across the markets.
Constraints on the onset of color transparency from quasi-elastic C up to (GeV
No full textQuasi-elastic scattering on C was measured in Hall C at
Jefferson Lab for space-like 4-momentum transfer squared in the range of
8--14.2\,(GeV/) with proton momenta up to 8.3\,GeV/. The experiment
was carried out in the upgraded Hall C at Jefferson Lab. It used the existing
high momentum spectrometer and the new super high momentum spectrometer to
detect the scattered electrons and protons in coincidence. The nuclear
transparency was extracted as the ratio of the measured yield to the yield
calculated in the plane wave impulse approximation. Additionally, the
transparency of the and shell protons in C was
extracted, and the asymmetry of the missing momentum distribution was examined
for hints of the quantum chromodynamics prediction of Color Transparency. All
of these results were found to be consistent with traditional nuclear physics
and inconsistent with the onset of Color Transparency
Ruling out Color Transparency in Quasielastic C(e,e'p) up to of 14.2 (GeV/c)
No full textInternational audienceQuasielastic C12(e,e′p) scattering was measured at spacelike 4-momentum transfer squared Q2=8, 9.4, 11.4, and 14.2 (GeV/c)2, the highest ever achieved to date. Nuclear transparency for this reaction was extracted by comparing the measured yield to that expected from a plane-wave impulse approximation calculation without any final state interactions. The measured transparency was consistent with no Q2 dependence, up to proton momenta of 8.5 GeV/c, ruling out the quantum chromodynamics effect of color transparency at the measured Q2 scales in exclusive (e,e′p) reactions. These results impose strict constraints on models of color transparency for protons
Market-specific and Currency-specific Risk during the Global Financial Crisis: Evidence from the Interbank Markets in Tokyo and London
No full textThis paper explores how international money markets reflected credit and liquidity risks during the global financial crisis. After matching the currency denomination, we investigate how the Tokyo Interbank Offered Rate (TIBOR) was synchronized with the London Interbank Offered Rate (LIBOR) denominated in the US dollar and the Japanese yen. Regardless of the currency denomination, TIBOR was highly synchronized with LIBOR in tranquil periods. However, the interbank rates showed substantial deviations in turbulent periods. We find remarkable asymmetric responses in reflecting market-specific and currency-specific risks during the crisis. The regression results suggest that counter-party credit risk increased the difference across the markets, while liquidity risk caused the difference across the currency denominations. They also support the view that a shortage of US dollar as liquidity distorted the international money markets during the crisis. We find that coordinated central bank liquidity provisions were useful in reducing liquidity risk in the US dollar transactions. But their effectiveness was asymmetric across the markets.
Foreign ownership in Vietnam stock markets - an empirical analysis
No full textThis paper investigates foreign ownership in the Vietnam stock market from 2007 to 2009 employing a rich and detailed dataset. From the perspective of informational asymmetry, the paper examines the relationship between the foreign ownership level and attributes of Vietnamese listed firm in Ho Chi Minh City Stock Exchange. The findings of the paper indicate that foreign investors have preference for large firms, firms with high book-to-market ratio and firms with low leverage. Foreign investors also avoid firms with dominant shareholders and prefer to invest in firms where they can have influence. The results imply that foreign investors favor to invest in firms where they can avoid informational asymmetry.foreign ownership, firm attributes, foreign investors, Vietnam
Extreme Returns without News: A Microstructural Explanation
No full textWhat triggers extreme exchange-rate returns? Though news is the source of volatility in standard theoretical models, in reality volatility is often unrelated to news. This paper shows that extreme exchange-rate returns -- and, more generally, high kurtosis of returns -- are statistically inevitable even in the absence of news. We identify four microstructural sources of return kurtosis in price-contingent order flow: (1) high kurtosis in the distribution of price-contingent order sizes; (2) clustering of price-contingent order executions at certain times of day; (3) clustering of order executions at certain price levels; and (4) the tendency of positive-feedback trading to propagate trends. Using simulations calibrated to price-contingent orders placed at a major foreign exchange dealing bank we show that when each factor operates in isolation, the one that contributes most to kurtosis in returns is kurtosis in the order-size distribution. When the factors operate simultaneously, however, their interactions prove far more important. Extreme returns in the absence of news should be viewed as natural rather than anomalous.kurtosis, exchange rates, order flow, high-frequency, microstructure, jump process, value-atrisk, risk management
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