•A new method for solving the multi-objective optimal power flow problem is proposed.•Total operation cost, total emitted emission, and proposed N-1 contingency index are considered as objectives.•A ...new security index is proposed.•The fuzzy decision-making approach is utilized to handle the multi-objective OPF problem.•AGSO is proposed to precise the convergence characteristic of conventional GSO algorithm.
This paper presents an adaptive group search optimization (AGSO) algorithm for solving optimal power flow (OPF) problem. In this study, different aspects of the OPF problem are considered to form the accurate multi-objective model. The system total operation cost, the total emission, and N-1 security index are first, second, and third ordered objectives, respectively. Additionally, to consider accurate model of the problem, transmission losses and different equality and inequality constrains, such as feasible operating ranges of generators (FOR) and power flow equations are taken into account. Moreover, this study presents adaptive form of conventional GSO to precise the convergence characteristic of GSO. The effectiveness and accuracy of the proposed method for solving the nonlinear and nonconvex problems is validated by carrying out simulation studies on sample benchmark test cases and 30-bus and 57-bus IEEE standard test systems. Based on the comprehensive simulation studies, the accuracy of the proposed method is validated.
•A two-stage automatic autism spectrum disease (ASD) diagnostic model based on sMRI.•1st stage consists of identifying edges of images by canny edge detection algorithm.•2nd stage, grid search ...optimization is applied to convolutional neural networks.•Proposed diagnostic method of ASD based on sMRI achieves a success rate of 100%•Superiority is shown by comparing it with recent studies and pre-trained models.
In this study, an automatic autism diagnostic model based on sMRI is proposed. This proposed model consists of two basic stages. The first stage is the preprocessing stage, which consists of removing unclear images, identifying the edges of the images by applying the canny edge detection (CED) algorithm, cropping them to the size required by the system, and finally enlarging the images five times with data augmentation. The data augmentation method should not affect the discrimination in the images such as coloring, and also since it is applied to both groups of autism spectrum disorders (ASD) and typical development (TD), it is performed with care not to cause any manipulation in the data. In the second stage, the grid search optimization (GSO) algorithm is applied to the deep convolutional neural networks (DCNN) used in the system to have optimal hyperparameters. As a result, the proposed diagnostic method of ASD based on sMRI achieves an outstanding success rate of 100%. The reliability of the proposed model is validated by testing with five-fold cross-validation, and its superiority is demonstrated by comparing it with recent studies and widely-used pre-trained models.
In this work, spectroscopic properties of (Lu0.25Gd0.75)2(1-x)Tm2xSiO5 (x = 0.04 and 0.005) single crystals were investigated. The material was found to be biaxial, exhibiting strong optical ...anisotropy, as clearly demonstrated in polarized absorption and emission spectra. Data from room temperature polarized absorption spectra were used in calculations within the phenomenological Judd-Ofelt model. The intensity parameters Ωt were established at Ω2 = 3.24 (±0.58), Ω4 = 2.96 (±0.24) and Ω6 = 0.86 (±0.14) 10−20 cm2. The values of fluorescence lifetimes of the 1D2 and 1G4 levels were measured and subsequently compared with those calculated using the Judd-Ofelt theory. The strong absorption bands located at wavelengths around 355, 460 and 790 nm, related to the 3H6 → 1D2, 1G4, 3H4 transitions, were found suitable for optical pumping of the investigated material. The characteristics of emission spectra recorded in the blue (ca. 455 nm) and IR (ca. 1750 nm) regions indicate that further investigations of stimulated emission within those wavelength ranges are well justified and can be considered promising.
•Spectroscopic investigations of Tm doped (Lu0.25Gd0.75)2SiO5 single crystals were conducted.•Material shows high potential for lasing in IR region ca. 1900 nm.•Influence of Anisotropy and temperature on spectroscopic properties is reported.
Ancillary Services in the Energy Blockchain for Microgrids Di Silvestre, Maria Luisa; Gallo, Pierluigi; Ippolito, Mariano Giuseppe ...
IEEE transactions on industry applications,
2019-Nov.-Dec., 2019-11-00, 20191101, Letnik:
55, Številka:
6
Journal Article
Recenzirano
Odprti dostop
The energy blockchain is a distributed Internet protocol for energy transactions between nodes of a power system. Recent applications of the energy blockchain in microgrids only consider the energy ...transactions between peers without considering the technical issues that can arise, especially when the system is islanded. One contribution of the paper is, thus, to depict a comprehensive framework of the technical and economic management of microgrids in the blockchain era, considering, for the first time, the provision of ancillary services and, in particular, of the voltage regulation service. When more PV nodes are operating in the grid, large reactive power flows may appear in the branches. In order to limit such flows, a reactive optimal power flow (R-OPF) is solved, setting the voltage at the PV buses as variables within prescribed limits. Each PV generator will thus contribute to voltage regulation, receiving a remuneration included in the transaction and certified by the blockchain technology. For showing how this system can work, a test microgrid, where some energy transactions take place, has been considered. For each transaction, the R-OPF assigns the reactive power to the PV buses. The R-OPF is solved by a glow-worm swarm optimizer. Finally, the paper proposes a method for remuneration of reactive power provision; this method, integrated into the blockchain, allows evaluating the contribution to voltage regulation and increases the transparency and cost traceability in the transactions. The application section shows the implementation of a Tendermint-based energy transaction platform integrating R-OPF and the earlier cited technical assessments.
Feature selection (FS) is recognized as one of the majority public and challenging problems in the Machine Learning domain. FS can be examined as an optimization problem that needs an effective ...optimizer to determine its optimal subset of more informative features. This paper proposes a wrapper FS method that combines chaotic maps (CMs) and binary Group Search Optimizer (GSO) called CGSO, which is used to solve the FS problem. In this method, five chaotic maps are incorporated with the GSO algorithm’s main procedures, namely, Logistic, Piecewise, Singer, Sinusoidal, and Tent. The GSO algorithm is used as a search strategy, while k-NN is employed as an induction algorithm. The objective function is to integrate three main objectives: maximizing the classification accuracy value, minimizing the number of selected features, and minimizing the complexity of generated k-NN models. To evaluate the proposed methods’ performance, twenty well-known UCI datasets are used and compared with other well-known published methods in the literature. The obtained results reveal the superiority of the proposed methods in outperforming other well-known methods, especially when using binary GSO with Tent CM. Finally, it is a beneficial method to be utilized in systems that require FS pre-processing.
•A novel feature selection method is proposed for classification task.•Five Chaotic Group Search Optimizers are investigated.•Twenty UCI datasets were used in the experiments.•Our methods got a higher accuracy results using a fewer number of features.
This letter proposes a two-layer active disturbance rejection control (ADRC) method with the compensation of estimated equivalent input disturbances (EID) for load frequency control (LFC) of ...multi-area interconnected power system. This method has a capability of rejecting the effects of random load variations and parameter uncertainties, and guaranteeing high dynamic performance. The state-space model of LFC system is established. Then a full-order generalized state observer (GSO) is employed in ADRC system to estimate EID. A stability condition is derived based on the small-gain theory. Simulation results demonstrate the robust performance of the proposed method, by comparing with traditional one.
•Measure the coordination between urbanization and air environment in the JJJ region.•Explore sustainable development path from the perspective of coordinated development.•Various Five-Year Plan ...policies have different impacts on coordinated development.
Urban agglomeration is an important geospatial unit for achieving SDGs. At the same time, air environment is the key to ensure the healthy life and safe production of mankind. Despite growing concern over the sustainable development in urban agglomeration, there is still little discussion on the coordination between air environment and urbanization within urban agglomeration. Here, the coupling evaluation index system was constructed from four urbanization aspects and three air environment aspects. Based on the real nonlinear internal relationship, the CG-GSO model was used to quantify the urbanization development level in the Beijing(Jing)-Tianjin(Jin)-Hebei(Ji) urban agglomeration from 2003 to 2017. It showed that social urbanization and economic urbanization were mainly the driving factors in single regions, and the urbanization development levels were rising steadily in single regions and urban agglomeration. In the air environment subsystem, the driving factors mainly existed in the air environment pressure and control, while the dynamic trends were fluctuating upward. On urbanization, urban agglomeration was conductive to the realization of regional sustainable development; but on air environment, the result was the opposite. In addition, the dynamic trend of the coupling coordination degree was far worse in urban agglomeration than in single regions. The scenarios were predicted and analyzed on barely and superiorly balanced development during different periods, and strong national pollution control policy was the key to promote the coordinated development between urbanization and air environment in the Beijing(Jing)-Tianjin(Jin)-Hebei(Ji) urban agglomeration. This study provides reference for sustainable development in urban agglomerations.
This paper deals with the simultaneous distributed generation (DG) planning and distribution network reconfiguration (SDGNR) issue. The problem is formulized as an optimization model which includes ...three types of variables, i.e. DGs location as the integer variables, DGs operating point as the continuous ones and switches open\close state as the binary variables. A new approach entitled three-dimensional group search optimization (3D-GSO) method is also introduced to cope with such a problem. The proposed method is a general optimization scheme applicable to all types of optimization problems which deal with an integer, continuous, and binary variables at the same time. The revised approach is successfully applied to the SDGNR problem with the objective of total loss reduction in power distribution systems. Power flow criteria, as well as operation constraints, are all together accommodated in the process of optimization. Five different scenarios at three load levels are also considered to cover all possible conditions. The validity of the proposed 3D-GSO approach in handling SDGNR problem is assured through comprehensive simulation studies on 33-bus and 69-bus test systems.
•GSO-based algorithm for integer space is introduced.•3D-GSO algorithm is proposed and successfully applied to the SDGNR problem.•Results of 3D-GSO approach compared with recently proposed algorithms.•A Fuzzy logic-based approach is used for simultaneous searching at diverse spaces.
Intrinsic luminescence in Ce-doped (Lu,Y)2SiO5 (or LYSO:Ce) single crystals have been studied by means of excitation luminescence spectroscopy in the vacuum ultraviolet energy range under synchrotron ...radiation. A previously unreported luminescence band with emission at 250 nm has been discovered as well as its thermal behavior was described in the temperature range 10–120 K. The excitation spectra as well as time-resolved properties of this band suggest that this emission corresponds either to the singlet component of self-trapped exciton or to a self-trapped exciton in the lutetium sublattice of LYSO single crystals.
•New previously unreported intrinsic emission band at 250 nm has been observed in LYSO single crystals.•Temperature dependencies of intrinsic luminescence have been measured and analyzed.•Two possible origins of new 250 nm emission are proposed and discussed.
Operasi satelit di Indonesia yang dikenal luas adalah tentang operasi satelit-satelit di orbit geostasioner (GSO) untuk misi telekomunikasi. Namun, dalam dekade terakhir ini, operasi satelit-satelit ...non-GSO di Indonesia meningkat dengan pesat. Sehingga, tujuan dari penelitian ini adalah mengetahui mengapa peningkatan tersebut terjadi dan mendapatkan gambaran tentang masa depan operasi satelit non-GSO di Indonesia. Untuk tujuan tersebut, dilakukan ulasan atas operasi satelit non-GSO yang lalu dan saat ini. Analisis dilakukan pada karakteristik misi, pemilik/operator, dan spesifikasi dari satelit-satelit tersebut. Selain itu, dilakukan kajian pustaka tentang tren global dan lingkungan strategis yang menentukannya. Hasil studi menyimpulkan bahwa penyebab pertumbuhan satelit non-GSO di Indonesia adalah bertambahnya penggunaan aplikasi penginderaan jauh, aplikasi M2M, dan pengembangan satelit oleh LAPAN. Di masa depan, diperkirakan naiknya penggunaan satelit non-GSO untuk penginderaan jauh akan disebabkan oleh faktor yang sama. Namun, untuk telekomunikasi, akan lebih didorong oleh beroperasinya konstelasi satelit global baru. Peningkatan penggunaan satelit non-GSO untuk penginderaan jauh tidak berakibat banyak pada kebutuhan frekuensi dan stasiun Bumi. Sementara, kenaikan penggunaan satelit non-GSO untuk telekomunikasi akan memerlukan tambahan alokasi frekuensi dan stasiun Bumi yang cukup banyak. Indonesian satellite operations are mainly known for the operation of geostationary orbit (GSO) satellites for telecommunication missions. In the last decade, however, the activities of non-GSO satellites in Indonesia are significantly increasing. Therefore, the objectives of this research are to find out the cause of the growth and to predict the future operation of non-GSO satellites in Indonesia. For such purpose, review on the operation of non-GSO satellites in the past and now was done. Analysis on the characteristics of their missions, owners/operators, and technical characteristics of the satellites were done. Literature studies on the global trends and their defining strategic environments were also done to complete the insight. The study shows that increase in the use of non-GSO satellites is caused by the growth in remote sensing application, M2M application, and development of LAPAN’s satellites. In the future, the growth of non-GSO remote sensing satellite is predicted to be caused by the same reason. The increase in the use of non-GSO telecommunication satellites, however, will be affected more by the new global trend. The increase in non-GSO remote sensing satellites does not affect significantly on the needs of frequency and ground stations. The increase in the non-GSO telecommunication satellites, however, needs significant additional frequency allocations and ground stations.
PDF
