Dual Scenarios Research Articles

Energy Storage Capacity Configuration Planning Considering Dual Scenarios of Peak Shaving and Emergency Frequency Regulation

New energy storage methods based on electrochemistry can not only participate in peak shaving of the power grid but also provide inertia and emergency power support. It is necessary to analyze the planning problem of energy storage from multiple application scenarios, such as peak shaving and emergency frequency regulation. This article proposes an energy storage capacity configuration planning method that considers both peak shaving and emergency frequency regulation scenarios. A frequency response model based on emergency frequency regulation combined with low-frequency load shedding is established, taking into account the frequency safety constraints of the system and the principle of idle time reuse, to establish a bi-level programming model. In the upper-level model, the optimization objective is to minimize the annual operating cost of the system during the planning period, combined with the constraints of power grid operation to plan the energy storage capacity. The lower-level model embeds frequency safety constraints with the optimization objective of minimizing the cost of fault losses. To solve the bi-level optimization problem, the Karush–Kuhn–Tucher (KKT) condition and Big-M method were used to transform the bi-level model into a single-layer linear model. Finally, an improved IEEE RTS-24 system was used for numerical verification. The results show that the method proposed in this article can reasonably plan the capacity of energy storage, improve frequency safety during system operation, and reduce the operating cost of the power grid.

Memory feedback signals in nonlinear coupled pitch-roll ship motions under narrow-band stochastic excitations

Initiating from the complexity of ship sailing environment and the nonlinear coupling hysteresis effect of its motion, we focus on the memory feedback shake-reducing strategy turning from the delay generally considered to exhibit undesired effects, and introduce it into the nonlinear coupled pitch-roll ship motions under loads incorporating stochastic disturbances to control the ship shaking and optimize the frequency band distribution of the stable navigation associated with the saturation. This paper then reports the deterministic equilibrium solutions of the roll and pitch response via the perturbation analysis of the third-order scale and successively explains the stability closely related to the saturation and bifurcations. Instead of just formula deduction, visually depict the distinction of equilibrium points and the determination conditions, and the effective shake-reducing frequency band coupled with the drift modulated by the memory feedback signals, and then integrate the moment method and stochastic Itô law to compute the steady-state moment and the mean square scale checked by numerical simulations. Set basic samples of the equation parameters for dual scenarios, and then track time histories of ship rolling and pitching as well as the marginal and joint probability evolutions to illustrate the resonance behavior and modes transition with the energy penetration in complementary ways. The results of our investigation present a new insight into the stability schemes of ship sailing issues.

Preferences of Medical Sciences Students for Work Contracts in Deprived Areas of Iran: A Discrete Choice Experiment Analysis.

BackgroundAn unequal distribution of human resources affects access to health-care services. This study aimed to elicit the preferences of medical, dentistry, and pharmacy students about attributes of work contracts in deprived areas of Iran; this is a primary important step to decrease inequity.MethodsTwo-hundred and one students were entered into the study through proportional sample size estimation from Kermanshah University of Medical Sciences in the west of Iran in 2018. The attributes of work contracts were determined using the discrete choice experiment (DCE) method, then possible dual scenarios of work contracts were designed through the D-efficiency method of SAS software and the data were collected using a questionnaire designed by the researchers. The conditional logistic model was used to analyze the data.ResultsSalary, workplace, side facilities, scholarship, and workload were considered as important factors for working in the deprived areas (p<0.001). There were differences between the students’ preferences regarding their residential areas, majors, and state or tuition-paying education (p<0.001). Higher payments, side facilities, and availability of quota after working in the deprived areas were considered as creators of higher utility, and working in deprived areas and high workload were considered as creators of lower utility (p<0.001).ConclusionThis study provides new evidence about the preferences of medical sciences students for work contracts in deprived areas of Iran. According to the findings, money is not the only factor that affects the decisions of medical sciences students related to working contracts in deprived areas of Iran. Designing work contracts that are matched with preferences of the workforce can lead to an improvement in equity, access, and utilization of health-care services.

Water Quality Prediction Model Based Support Vector Machine Model for Ungauged River Catchment under Dual Scenarios

Water quality analysis is a crucial step in water resources management and needs to be addressed urgently to control any pollution that may adversely affect the ecosystem and to ensure the environmental standards are being met. Thus, this work is an attempt to develop an efficient model using support vector machine (SVM) to predict the water quality of Langat River Basin through the analysis of the data of six parameters of dual reservoirs that are located in the catchment. The proposed model could be considered as an effective tool for identifying the water quality status for the river catchment area. In addition, the major advantage of the proposed model is that it could be useful for ungauged catchments or those lacking enough numbers of monitoring stations for water quality parameters. These parameters, namely pH, Suspended Solids (SS), Dissolved Oxygen (DO), Ammonia Nitrogen (AN), Chemical Oxygen Demand (COD), and Biochemical Oxygen Demand (BOD) were provided by the Malaysian Department of Environment (DOE). The differences between dual scenarios 1 and 2 depend on the information from prior stations to forecast DO levels for succeeding sites (Scenario 2). This scheme has the capacity to simulate water-quality accurately, with small prediction errors. The resulting correlation coefficient has maximum values of 0.998 and 0.979 after the application of Scenario 1. The approach with Type 1 SVM regression along with 10-fold cross-validation methods worked to generate precise results. The MSE value was found to be between 0.004 and 0.681, with Scenario 1 showing a better outcome.

Exact Outage Probability Analysis of Dual-Transmit-Antenna V-BLAST With Optimum Ordering

An exact outage probability analysis of zero-forcing V-BLAST technique with two transmit antennas and $r$ receive antennas $(r\geq 2)$ is provided under a decoding order that is optimum in the sense of minimizing the outage probability. Different from the earlier approximated analyses, an exact closed-form expression on the outage probability is attained without neglecting the effect of error propagation. Assuming a one-bit feedback from the receiver to the transmitter, the optimal power and rate allocation values are numerically computed based on the exact outage probability expression under different objective functions. The presented results are also applicable for the corresponding dual scenarios that may involve antenna selection and/or user scheduling.

Large-Scale Biomass Classification in Boreal Forests With TanDEM-X Data

Boreal forests are characterized by a rather homogenous stand structure which allows by means of a single allometric equation to estimate biomass from forest height with sufficient accuracy and, therefore, to use this equation for quantitative biomass classifications. In this paper, interferometric TanDEM-X DEM data is used to estimate forest height over boreal forest systems. The accuracy of the height inversion is evaluated for single and also dual baseline scenarios, under summer and winter conditions. Then, an allometric equation is used to transfer forest height to biomass. For this, two forest sites, boreal (Krycklan) and hemi-boreal (Remningstorp) in north and southern Sweden, respectively, are investigated. A performance analysis is carried out in order to estimate the maximum number of biomass classes obtained, depending on the height estimation accuracy. For summer acquisitions, four biomass classes can be obtained, with a maximum biomass class of >200 Mg/ha. For winter acquisitions or when a mixed summer – winter approach is applied, five biomass classes, up to 220 Mg/ha, can be obtained. This classification shows a good agreement with CORINE, an existing land cover classification, and can improve it by adding quantitative forest biomass classes with a high spatial resolution of 16x16 m.

Connecting Across Cultures and Time:

This paper discusses what museums can do to address the issues brought about by global change and ensuing social, economic and cultural tensions. Just as globalisation can encourage international and intercultural relationships, enrichment and creativity, so too can it foster intolerance and the destruction of cultural heritage and diversity—dual scenarios that are currently playing out in several parts of the world. Traditional policies seem, moreover, unable to successfully confront nationalism, xenophobia, interreligious conflicts, social tensions, and extremism. New approaches to global change are needed. How can museums contribute to social cohesion and intercultural exchange in the current context of changing demographics? What approaches can they take to enhance cultural diversity and inclusion, promote cultural exchange, and foster the new identities of 21st century communities? In the present article, I explore Italy's longstanding history as a cultural meeting ground and examine five recent projects undertaken by museums in different Italian communities in response to globalisation and the cultural diversification of Italian society.

Two hosts and a caller: Analysing call sequences in a dual-host radio talkback setting

Investigation into the impact of the stages of a radio call on host–caller interaction has traditionally been conducted in single host scenarios, whereby one host interacts with one caller. Further, this analysis has often been done in the context of talk radio that is designed to promote a sense of conflict in order to entertain its audience. However, what of dual or multi-host scenarios, where a number of hosts are co-participants when interacting with callers? This article considers a talkback segment within a chat-based program in which two studio-based hosts are involved in conversation with callers. It considers previous research into call sequence as applied to this scenario and reveals that rather than working to challenge the caller, the hosts work together to enable the callers to challenge the hosts but in a way that orients to sociability rather than conflict.

Applying fuzzy bi-dimensional scenario-based model to the assessment of Mars mission architecture scenarios

Sending man to Mars has been a long-held dream of humankind. NASA plans human planetary explorations using approaches that are technically feasible, have reasonable risks and have relatively low costs. This study presents a novel Multi-Attribute Decision Making (MADM) model for evaluating a range of potential mission scenarios for the human exploration of Mars. The three alternatives identified by the Mission Operations Directorate (MOD) at the Johnson Space Center (JSC) include split mission, combo lander and dual scenarios. The proposed framework subsumes the following key methods: first, the conjunction method is used to minimize the number of alternative mission scenarios; second, the Fuzzy Risk Failure Mode and Effects Analysis (RFMEA) is used to analyze the potential failure of the alternative scenarios; third, the fuzzy group Real Option Analysis (ROA) is used to estimate the expected costs and benefits of the alternative scenarios; and fourth, the fuzzy group permutation approach is used to select the optimal mission scenario. We present the results of a case study at NASA’s Johnson Space center to demonstrate: (1) the complexity of mission scenario selection involving subjective and objective judgments provided by multiple space exploration experts; and (2) a systematic and structured method for aggregating quantitative and qualitative data concerning a large number of competing and conflicting mission events.

About the possibility of five-dimensional effective theories for low-energy QCD

The AdS/QCD models suggest the interesting idea that the effective theory of low-energy QCD may be formulated as a 5-dimensional field theory in the weak coupling regime in which the fifth coordinate plays a role of inverse energy scale. Taking the point of view that this is just an efficient parameterization of the non-perturbative dynamics of strong interactions, we discuss on a qualitative level an alternative possibility for a simpler 5-dimensional parameterization of the main phenomena in the low-energy QCD. We propose to interpret the effect of chiral symmetry breaking as the effective appearance of a compactified extra dimension with the radius of the order of the inverse scale of chiral symmetry breaking. Following some heuristic arguments two dual scenarios for the emergence of the excited light mesons are introduced. In the first scenario, the meson resonances are interpreted as the effects of Kaluza–Klein excitations of quarks inside mesons, in the second one as the formation of gluon strings wound around the compactified dimension an appropriate number of times. Matching of these scenarios permits us to express the slope of radial Regge trajectories through the order parameters of the chiral symmetry breaking, with the compactification radius being excluded. This example shows qualitatively that the extra dimension may play an auxiliary role providing a short way for deriving new relations.

Modelling and Simulation of the Conversion of Correlated and Unbalanced Antenna Diversity Systems

Due to the increasing interest in mobile/wireless communication, there has been a continuous research in antenna diversity to combat fading. And the model of correlated and unbalanced diversity branches reflects the real-world scenario. The diagonalizer is introduced here before the diversity branches are combined, which can transform the correlated and balanced branches to the uncorrelated and unbalanced ones, and vice versa. This paper assumes a generic model, in which noise and interference components are correlated with a correlation equal to or smaller than the correlation of signal components. Discussions on how to maximize diversity gains are made in various signal and noise conditions, and with different combining methods. Modelling and simulation of a real world example and the performance are shown in the paper for various dual diversity scenarios.

A subjective assessment of alternative mission architectures for the human exploration of Mars at NASA using multicriteria decision making

The primary driver for developing missions to send humans to other planets is to generate significant new scientific knowledge. NASA plans human planetary explorations with an acceptable level of risk consistent with other manned operations. Space exploration risks cannot be completely eliminated. Therefore, an acceptable level of cost, technical, safety, schedule, and political risks and benefits must be established for exploratory missions. This study uses a multicriteria decision model to identify the risks and benefits associated with three alternative mission architecture scenarios for the human exploration of Mars. The three alternatives identified by the Mission Operations Directorate at the Johnson Space Center include split, combo lander, and dual scenarios. The model considers seven phases of the mission: (1) Earth vicinity/departure, (2) Mars transfer, (3) Mars arrival, (4) planetary surface, (5) Mars vicinity/departure, (6) Earth transfer, and (7) Earth arrival. Analytic hierarchy process, subjective probability estimation, and the entropy method are used to capture experts’ beliefs concerning the risks and benefits of the three alternative scenarios through a series of sequential, rational, and analytical processes.