Excessive Losses Research Articles

Solar-photovoltaic-power-sharing-based design optimization of distributed energy storage systems for performance improvements

Proper energy storage system design is important for performance improvements in solar power shared building communities. Existing studies have developed various design methods for sizing the distributed batteries and shared batteries. For sizing the distributed batteries, most of the design methods are based on single building energy mismatch, but they neglect the potentials of energy sharing in reducing battery capacity, thereby easily causing battery oversizing problem. For sizing the shared batteries, the existing design methods are based on a community aggregated energy mismatch, which may avoid battery oversizing but cause another severe problem, i.e., excessive electricity losses in the sharing process caused by the long-distance power transmissions. Therefore, this study proposes a hierarchical design method of distributed batteries in solar power shared building communities, with the purpose of reducing the battery capacity and minimizing the energy loss in the sharing process. The developed design method first considers all the distributed batteries as a virtual ‘shared’ battery and searches its optimal capacity using genetic algorithm. Taking the optimized capacity as a constraint, the developed method then optimizes the capacities of the distributed batteries for minimizing the energy loss using non-linear programming. Case studies on a building community show that compared with an existing design method, the proposed design can significantly reduce the battery capacity and electricity loss in the sharing process, i.e. 36.6% capacity reduction and 55% electricity loss reduction. This study integrates the considerations of aggregated energy needs, local PV power sharing, advanced community control, and battery storage sharing, which will be useful to optimize three functions (energy efficiency, energy production and flexibility) in a positive energy district towards energy surplus and climate neutrality.

Fungicide Cost Reduction with Soybean Rust-Resistant Cultivars in Paraguay: A Supply and Demand Approach

Soybean rust (SBR) is one of the most serious diseases for Paraguay’s economy. To avoid excessive financial losses due to SBR, farmers utilize fungicides. Increasing fungicide costs are, therefore, becoming a threat to farmers’ incomes. Developing SBR-resistant cultivars is a possible solution to this problem. To investigate the effects of SBR-resistant cultivars on soybean farmers in Paraguay, we constructed a model for the supply and demand of soybeans considering yields, cultivated area, changes in the stock quantity of soybeans, exports of soybeans and soybean products, feed demand for soybean cake and price linkage functions. We established three scenarios: an SBR pandemic in which fungicides become ineffective (Scenario 1) and the adoption of SBR-resistant cultivars in 33% (Scenarios 2) and 75% (Scenarios 3) of cultivated areas. The estimation of these three scenarios demonstrates that SBR-resistant cultivar adoption will significantly reduce current fungicide costs for farmers by 112–253 million United States dollars (USD). The potential benefits of the widespread dissemination of SBR-resistant cultivars are also considered in terms of economic disparities and environmental risks. To establish a more sustainable agricultural industry, earlier dissemination of such cultivars is required.

Silicon polarization beam splitter at the 2 μm wavelength band by using a bent directional coupler assisted with a nano-slot waveguide.

A silicon-based polarizing beam splitter (PBS) working at the 2 μm wavelength band is proposed and demonstrated experimentally by using a bent directional coupler assisted with a nano-slot waveguide. The nano-slot width is chosen as 180 nm so that the present PBS can be fabricated with MPW foundries. In theory, the designed PBS has extinction ratios (ERs) of >15 dB and >30 dB for TM- and TE- polarizations in the wavelength range of 1825-2020 nm, respectively. For the fabricated PBS, the excess losses (ELs) are low (∼0.5 dB) while the measured results show the ERs are >15 dB and >20 dB for TM- and TE-polarizations in the wavelength band of 1860-1980 nm.

Optimal design for double reheat coal-fired power plants with post-combustion CO2 capture: A novel thermal system integration with a carbon capture turbine

The development of post-combustion capture is greatly restricted by its high energy consumption and the thermal efficiency penalty resulting from absorbent regeneration. This study provides novel insights into the design of a thermal system for double reheat coal-fired power plants integrated with full-scale post-combustion CO2 capture. To this end, this study proposed a modified thermal system integration scheme that included an extraction backpressure turbine called carbon capture turbine (CCT) to provide thermal energy for the regenerative heaters and CO2 capture system. A generalized thermal economy calculating framework and a thermal system parameter optimization model was also established to maximize the cycle thermal efficiency for the proposed scheme. A new unit was designed based on the modified scheme, and its parameters were determined by taking a 1000 MW double reheat coal-fired unit as a reference. These parameters were then optimized via dynamic adaptive particle swarm optimization. Compared with a conventional retrofitted unit, the coal consumption and CO2 emission rates of this newly designed unit were reduced by 0.01264 kg/(kW·h) and 0.00423 kg/(kW·h) after the parameter optimization, respectively. An exergy analysis for the proposed system shows that using CCT can efficiently prevent the extraction of steam superheat and the mismatch between the intermediate pressure cylinder exhaust and the reboiler from generating excessive exergy losses.

To VaR, or Not to VaR, That is the Question

This paper discusses the value-at-risk (VaR) concept and assesses the financial adequacy of the price probability determined by frequency of trades at price p. We take the price definition as the ratio of executed trade value to volume and show that it leads to price statistical moments, which differ from those, generated by frequency price probability. We derive the price n-th statistical moments as ratio of n-th statistical moments of the value and the volume of executed transactions. We state that the price probability determined by frequency of trades at price p doesn’t describe probability of executed trade prices and VaR based on frequency price probability may be origin of unexpected and excessive losses. We explain the need to replace frequency price probability by frequency probabilities of the value and the volume of executed transactions and derive price characteristic function. After 50 years of the VaR usage main problems of the VaR concept are still open. We believe that VaR commitment to forecast the price probability for the time horizon T seems to be one of the most tough and expensive puzzle of modern finance.

ОБЛІКОВО-АНАЛІТИЧНЕ ЗАБЕЗПЕЧЕННЯ УПРАВЛІННЯ ВИРОБНИЧИМИ ЗАПАСАМИ

In the course of research it has been stated that the category of «inventories» is not only the object of accounting, but also the object of management, so the identification of inventories in the assets upon receipt at the enterprise is the initial stage of the accounting process. The process of material and technical base management begins at the stage of searching for suppliers, delivery conditions, formation of the logistics component, determination of transport and procurement costs. There is no doubt that the additional costs associated with these processes will affect the formation of the value of purchased inventories. Therefore, the authors emphasize that the methods of estimating inventories at their receipt and disposal play an important role in accounting, as they affect the formation of the cost of finished goods produced from inventories, and hence the overall financial performance of the enterprise. It should also be taken into account that in accordance with the norms of UAS 9, only the amounts of transportation and procurement costs related to the acquisition (receipt) of inventories are subject to inclusion in the initial cost. In practice, the increase in the value of inventories often includes costs incurred in connection with the internal transportation of inventories on the territory of the enterprise or between its structural units; costs arising from the return of inventories to the supplier; costs for loading, transportation, transshipment and insurance of inventories, finished products (goods), freight forwarding and other services related to the sale of products (goods). Such costs do not affect the formation of the initial cost of inventories. Therefore, the authors highlighted the need for a clear delineation of these costs at specific enterprises with the reflection of provisions in the Order (Regulation) on accounting policies. Most scientists discuss the feasibility of search for a method of cost allocation during transportation, because during this process there can be losses of inventories both within the established norms of natural loss, excessive losses and shortages, as well as spoiled inventories found during asset recognition. The authors gave their own view on the possibility of solving this problem. The solving approach has been presented as well as the peculiarities of the reflection of the distributed transport and procurement costs in the system of accounting have been considered. The situation when the company transport both purchased inventories and those, sold to customers, with its own transport has been considered. In such cases, the authors suggest a method of allocating transportation costs with subsequent allocation to transport and procurement costs, which increase the cost of purchased inventories and distribution costs.

Limitation on Trader Fund Losses under the CARES Act of 2020

Hedge funds are characterized by a significant complexity of their tax attributes. In this paper, we explain how hedge fund investors might be affected by a limitation on excess business losses codified in a new IRC Section 461(l), introduced as a part of the TCJA of 2017 and later amended by the CARES Act of 2020. In order to allocate business losses a hedge fund must be a trader fund. We thus discuss what makes a hedge fund a trader fund, whether management and performance fees of a trader fund are deductible as trade or business loss, and whether trader fund losses constitute passive activity losses. After explaining the relationship between hedge fund losses and business losses, we illustrate with simple examples how the new provisions of the CARES Act under Section 461(l) may affect hedge fund investors. We find that compared to TCJA some of these new provisions are beneficial while others are detrimental to investors. On the balance, Section 461(l) remains punitive, uneconomic, and unnecessary.

ПРОГНОЗУВАННЯ ОБСЯГІВ РЕАЛІЗАЦІЇ ПРОДУКЦІЇ ЗА МЕТОДОМ ЛІНІЙНОГО ПРОГРАМУВАННЯ (НА МАТЕРІАЛАХ НЕМИРІВСЬКОГО КХП, М. НЕМИРІВ ВІННИЦЬКОЇ ОБЛ.)

In this article reveals an example of forecasting the volumes of sales goods through ways of implement optimization analysis, that is by linear programming method. For example, volume of production goods for realization her consumers no must to exceed of determined out maximum or to be lower by minimum, what can to foreseeing in this task. For decision tasks of linear programming with a large number of variables and constraints, decomposition methods are used, which allow instead of the original problem to solve tasks of little volume. In general methodology of linear programming together with simplex-method is considered on the example Nemyriv bakery, where determined out profit on unit bakery products, obtained through the optimal ratio of material resources and costs incurred. In analysis and treatment of economic activities the each enterprises, particularly at composition forecast as to volumes of sales goods with aim of receiving profit, linear programming maybe successfully used out for decision tasks with optimization of development and organization trade processes upon regarding the sale of its products. With point of view management a tasks of linear programming – this tasks of optimal using resources. In each event planning of production goods necessity have on attention, which different productions resources (workforce, raw, materials, means of production) are limited, and also which known norm of costs these resources on different kinds goods, or possible are multiples variants to separating production resources. In our work, we ascertained that in analysis, compliance is checked of demand for bakery products to stocks of most-important kinds raw and materials together with costs as most important conditions for receive profit on enterprises and avoiding of excessive and unforeseen losses. With aim of rise efficiency of enterprises activities necessary and further to look at question of renewing assortment goods and increase quality her, increasing volumes of production, maximum of loading production powers equipment, efficiency using of available resources.

ОБЕСПЕЧЕНИЕ ИМУЩЕСТВЕННЫХ ПРАВ УЧАСТНИКОВ УГОЛОВНОГО ПРОЦЕССА ПРИ НАЛОЖЕНИИ АРЕСТА НА ИМУЩЕСТВО: ПРОБЛЕМЫ И ПУТИ РЕШЕНИЯ

The object of the study is the modern theoretical and legal problems of ensuring the rights of “third parties” in criminal proceedings in the case of the application of the seizure of property. The author aims to: 1) identify problems of legal regulation of the procedural status of persons whose property may be seized; 2) determine the criteria for the validity of the seizure of property in general and its individual types, in particular (for example, the seizure of shares); 3) propose ways to solve the problems of protecting the rights of persons who are not official participants in criminal proceedings, whose property has been seized. The research is based on the study of scientific sources, the legislative basis of criminal proceedings, subordinate and related official documents (resolutions of the Plenum of the Supreme Court of the Russian Federation, legal positions of the Constitutional Court of the Russian Federation, statistical data, published judicial practice). Generalization, synthesis, abstraction, various types of analysis (systems, structural-functional, formal-logical, formal-legal and comparative-legal), legal modeling, legal-sociological and legal statistics methods were used. The authors make the following conclusions: (1) the coincidence in the main parameters of the procedure for the imposition of arrest on property and investigative actions testifies to the complex nature of the former, its fulfillment of a double task: the formation of evidence and the provision of possible property penalties; (2) the restriction of the constitutional right of ownership when seizing the property of one person affects (directly, indirectly, impliedly, potentially) the rights and legitimate interests of a wider range of persons, including legal ones. Economic relations in such conditions become unstable, and economic entities suffer excessive (and unjustified) losses. The authors propose to draw the legislator's attention to the need to regulate the procedural potential of persons (so-called “third parties”) whose rights and legitimate interests may be affected by the seizure of the property of other persons; (3) the procedure for the imposition of arrest on property presupposes the existence of sufficient grounds. The category is evaluative, it acquires a large share of subjectivity, which allows suggesting the expediency of changing it to the “presence of sufficient evidence confirming the fact of obtaining property by criminal means”.

Optimal Placement of Electric Vehicle Charging Stations in a Distribution Network With Randomly Distributed Rooftop Photovoltaic Systems

The increasing number of electric vehicles (EVs) in today’s transport sector is gradually leading to the phasing out of petroleum-based vehicles. However, the rapid deployment of EVs largely depends on the coordinated and fast expansion of EV charging stations (EVCSs). The integration of EVCSs in the modern distribution network characterized by increased penetration of randomly distributed photovoltaic (PV) systems is challenging as they can lead to excessive power losses and voltage deviations beyond acceptable limits. In this paper, a hybrid bacterial foraging optimization algorithm and particle swarm optimization (BFOA-PSO) technique is proposed for the optimal placement of EVCSs into the distribution network with high penetration of randomly distributed rooftop PV systems. The optimization problem is formulated as a multi-objective problem minimizing active and reactive power losses, average voltage deviation index, and maximizing voltage stability index. The IEEE 69 node distribution network is used as the case network. The simulation is done using MATLAB to integrate the EVCSs in five cases of randomly sized and placed PV systems in the distribution network. For all five cases, a minimal increase in power losses is recorded with minor changes in the voltage deviation and stability indices due to the placement of the EVCSs. But for the voltages of nodes 29 to 48, the other node voltages remain unchanged upon placement of the EVCSs. The largest increase in power losses due to the EVCSs being brought into the network with PVs was noticed in case 3 (from 142.27kW, and 62.90kVar to 147.65kW, and 72.48kVar).

Peculiarities of search for placer deposits of gold of the south of Ukraine

The long-term high level of world gold prices against the background of depletion of reserves with easily extracted metal leads to the search for and introduction into industrial development of deposits, even with low-tech ores and sands. This, in turn, requires the introduction of effective technologies for the enrichment and extraction of gold, contributes to the improvement of methods of exploration. At present, numerous manifestations of placer gold of various scales are known in the sedimentary strata of Meso-Cenozoic deposits in the south of Ukraine. But the real picture of the distribution and the actual scale of gold deposits in Ukraine are uncompleted and unreliable. This is due to the inconsistency of the applied search technique, which was aimed at identifying near-subglacial valley deposits, to the actual properties of gold-bearing formations. Gold in most Ukrainian placers is represented mainly by small, fine and dispersed particles in a significantly clay substrate. Therefore, the traditional geological samples washing by tray led to excessive losses of fine gold and to a significant underestimation of the gold potential. That is why we need to revise the results of previously obtained geological data. Detection of placer gold deposits of Ukraine is possible under the condition of increasing the efficiency of the local forecast and the reliability of field research. The most favorable situations for the accumulation of a useful component are structural denudation traps in tectonic depressive zones. The technology of sample enrichment must correspond to the actual properties of specific raw materials in the placer object. The types of technological equipment are given and some ways of increase of efficiency and reliability of test are offered. The article continues the series of publications devoted to solving the problems of studying placer gold content with a dominant share of fine and dispersed gold in sedimentary formations of the south of Ukraine.

Development of High-Current Solid-State Power Controllers for Aircraft High-Voltage DC Network Applications

Solid-state power controllers (SSPCs) have been received increasing attention as they can configure the electrical system and protect the system by fast tripping mechanism at the same time. Although the high-voltage direct current (HVDC) electrical system can bring sustainable savings on the cables' weight and losses, the protection can be considerably challenging. SSPCs have been successfully utilized for 28V DC aircraft onboard network. However, high-voltage ones are impeded by the vast over-voltage and the excessive losses generated from SSPC switching. This paper tries to fill this gap and presents the development of high-power SSPCs for a ±270VDC network of a future turboprop aircraft. Comprehensive designs of proper over-voltage suppression along with SSPC thermal management are presented in this paper. Besides, a comparative study on the SSPC device is carried out. Two prototypes, including a single MOSFET module and paralleling several discrete MOSFET devices, are built and then tested in the experiment. It has been validated that the proposed voltage clamping design cannot only effectively suppress the over-voltage, but also limit the SSPC temperature increase during switching for both candidates. After comparing the conduction losses, maximum junction temperature, power density, weight and volume, the single device solution is recommended as a preferable SSPC option for future aircraft.

Central counterparty capital and nondefault losses

This paper analyses the components of central counterparty (CCP) capital requirements and makes several observations on the potential for loss absorption. Our first observation on default losses appears to be widely understood in the industry: as long as the CCP is not prevented from following the standard loss waterfall in its rule book, any losses that arise directly from member defaults can be absorbed by using existing CCP resources together with rule book powers to allocate any excess losses back to surviving members. Our second observation is a new frequency/severity result on nondefault losses. These are losses that are not directly due to a member default or are not covered by the rule book: the chance that such a loss exceeds the regulatory capital actually held is a very rare (at most, a two in a thousand) event. Moreover, the expected shortfall of such an event is an insurable quantum of less than one year’s profit to the healthy CCP. In the absence of an empirical database on CCP losses, these observations are ultimately inferred from comparable loss data from the 2008 Bank for International Settlements Loss Data Collection Exercise and from tail loss severity parameters implicit in existing CCP regulatory capital requirements.

Critical phosphorus values from the Better Fertiliser Decisions for Pastures project: early insights from validation trials

Phosphatic fertilisers have made grazing in the south-west of Western Australia (WA) viable. However, there is evidence that a large proportion of pasture paddocks exceed soil test critical values at which 95% of maximum yield is achieved as identified in the national Better Fertiliser Decisions for Pasture (BFDP) project. Of 22 000 soil samples collected between 2009 and 2020, 56% exceeded the critical value for phosphorus (P), although there were constraints to potassium (K) and sulfur (S) and from soil acidity. Soils with available P exceeding the critical value are expected to lead to excessive losses of P to waterways, resulting in eutrophication. A trial program was established to validate the critical P values from BFDP so that concerns can be addressed about the relevance of these critical P values to WA conditions and to contemporary pasture varieties. Measured relative yields for 19 trials in the first year were mostly within 10% of that predicted from BFDP for soils with a P buffering index (PBI) >10. Soils with PBI <10 had measured relative yields up to 25% greater than predicted by BFDP, suggesting response calibrations for low PBI soils may require adjustment in the BFDP dataset. Some pasture yield gaps occurred when soil pH and P were low. Application of nitrogen (N), K and S almost doubled the yield when P was limiting or sufficient. Agronomic advice and practice should seek to optimise these multiple inputs, thereby optimising P use rather than applying P to levels above the critical value.

A simple and robust approach for expected shortfall estimation

In risk management, estimating expected shortfall, though important and indispensable, is difficult when the sample size is small. This paper suggests a recipe for meeting such a challenge. A tail-based normal approximation with explicit formulas is derived by matching a specific quantile and the mean excess square of the sample observations. To enhance the estimation accuracy, we propose an adjusted tail-based normal approximation based on the sample's tail weight. The adjusted expected shortfall estimator is robust and efficient in the sense that it can be applied to various heavy-tailed distributions, such as Student t, lognormal, Gamma and Weibull, and the errors are all small. Moreover, compared with two common expected shortfall estimators -- the arithmetic average of excessive losses and extreme value theory estimator -- the proposed estimator achieves smaller mean squared errors for small samples, especially at high confidence levels. The properties of linear transformations on the expected shortfall estimator are also investigated to ensure its practicality.

THE REACTION OF AIRLINE STOCKS IN EUROPE TO THE COVID-19 PANDEMIC: AN EVENT STUDY METHODOLOGY

The COVID-19 pandemic has struck all life, global economy, and financial markets. It stopped airline transportation in Europe and many regions of the world for a certain period as well as affecting many businesses negatively. In this process, naturally, excessive losses occurred in stock markets. Airline stocks were among the most affected by this situation. From this point of view, this study analyzes 38 airline stocks traded in the stock markets of 14 European countries with “the event study methodology”. The main purpose is to compare the reaction of the airline stocks traded in the stock markets of these countries to the pandemic and to determine whether a statistically significant cumulative average abnormal return is provided from them. Accordingly, event windows are determined as short and long windows within the scope of the event study. The findings show that a statistically significant cumulative average abnormal returns for airline stocks in all countries occurred in the -50 +50 event window. Besides, in short event windows around the pandemic announcement on March 11, which is accepted as the event date in this study, airline stocks in some countries respond to the pandemic significantly, while others do not.

One More Config is Enough: Saving (DC)TCP for High-Speed Extremely Shallow-Buffered Datacenters

The link speed in production datacenters is growing fast, from 1 Gbps to 40 Gbps or even 100 Gbps. However, the buffer size of commodity switches increases slowly, e.g., from 4 MB at 1 Gbps to 16 MB at 100 Gbps, thus significantly outpaced by the link speed. In such extremely shallow-buffered networks, today's TCP/ECN solutions, such as DCTCP, suffer from either excessive packet losses or significant throughput degradation. Motivated by this, we introduce BCC, <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> a simple yet effective solution that requires only one more ECN configuration (i.e., shared buffer ECN/RED) at commodity switches. BCC operates upon real-time global shared buffer utilization. When available buffer space suffices, BCC delivers both high throughput and low packet loss rate as prior work; When it gets insufficient, BCC automatically triggers the shared buffer ECN to prevent packet loss at the cost of sacrificing a small amount of throughput. BCC is readily deployable with existing commodity switches. We validate BCC's efficacy in a 100G testbed and evaluate its performance using extensive simulations. Our results show that BCC maintains low packet loss rate persistently while only slightly degrading throughput when the buffer becomes insufficient. For example, compared to current practice, BCC achieves up to 94.4% lower 99th percentile flow completion time (FCT) for small flows while only degrading average FCT for large flows by up to 3%.

Influence of field-dependent critical current on harmonic AC loss analysis in HTS coils for superconducting transformers supplying non-linear loads

There are two main obstacles in front of the development of high temperature superconducting (HTS) technology for electric power network applications; tape price and cooling cost. In order to reduce cooling cost, it is vital to evaluate AC transport current loss of the tapes precisely and then reduce it by some design innovative approaches. In addition, AC transport current loss in HTS material is a critical design variable for large-scale power network applications such as HTS transformers, superconducting fault current limiters, and power cables, since they are continuously carrying the network/load current during their operating life. In existing power networks, harmonic production sources are commonly used and thus, currents are distorted. Therefore, the effect of nonsinusoidal current on the critical apparatus in the network such as transformer must be studied. In this paper, AC transport current loss of a single-turn 2G YBCO HTS coil was modeled and numerically calculated under nonsinusoidal transport current using finite element method. Furthermore, influence of dependency of critical current density to magnetic field on the AC transport current loss of HTS coil when carries distorted currents was considered. It was observed that nonsinusoidal current causes excessive losses in HTS coil. On the other hand, a case study on an HTS transformer supplying non-linear load was considered to study the loss increment as well as heat load change. It was observed that current harmonics increases the AC loss, and heat load of transformer and decreases the efficiency, consequently.

Spectrally selective fundamental core mode suppression in optical fibre containing absorbing rods

The feasibility of making a wavelength-selective fibre filter using fibre with absorbing rods in its silica cladding has been demonstrated theoretically for the first time. The technique described in this paper is of great practical interest for designing fibre lasers and amplifiers emitting at wavelengths where lasing is impeded by the presence of more energetically favourable radiative transitions in the active medium. In addition, the approach proposed here can be used for stimulated Raman scattering suppression. The unique feature of the fundamental core mode suppression mechanism examined is that there is a (bending) controlled spectral width of a region where excess losses are produced.

GIC-Inclusive State Estimator for Power System Awareness During Geomagnetic Disturbance Events

Geomagnetic disturbances (GMDs) threaten the secure and reliable operation of the electric power grid. During a GMD, geomagnetically induced currents (GICs) cause additional reactive power losses and a lowered voltage profile. Preventing and mitigating a widespread system collapse in such an occurrence requires accurate knowledge of the current system state. This is provided by power system state estimation, but as traditional methods do not account for GIC-related monitoring and modeling, they may fail to provide accurate results during a GMD. Therefore, in this work excess reactive power losses are explicitly modeled in the state estimation method and GIC-related values are included among the states and measurements. The modeling scheme is thoroughly discussed and estimation results on a 20 bus and 150 bus case validate the estimation accuracy improvement provided by a GIC-inclusive modified state estimator during a GMD.