Distribution Constraints Research Articles

Research on Brake Force Distribution Control Strategy of Electric Vehicle Subtitle as needed

An effective regenerative braking control strategy can increase the energy recovery efficiency of electric vehicles. Through the analysis of the braking force distribution constraint conditions of electric vehicles, under the stable working conditions to ensure that the wheels are not locked, the braking force is distributed to the driving wheels as much as possible, and the front and rear wheel braking force distribution control lines are proposed and distributed according to the braking force. The control line has a control strategy in place. The ADVISOR software was used to build the electric vehicle model, and the control strategy was embedded in it. The results show that compared with the ADVISOR braking force distribution strategy, the braking energy recovery rate and battery life are improved. Verify the effectiveness of the control strategy.

Key parameters of the structure and evolution of the Okinawa Trough: Modelling results constrained by heat flow observations

Heat flow data (664 measurements) in the Okinawa Trough and adjacent areas are edited and analysed in this study. The distribution of heat flow in the study area is obviously correlated with tectonic zones. The heat flow is extremely high and variable in the back‐arc basin and extremely low in the trench. A 2D transient heat conduction‐advection model is used to test and determine the thermal structure and evolution of the Okinawa Trough under the heat flow distribution constraint. The results show that (a) high sedimentation rates can reduce heat flow by 30–35%; lower heat flow in the southern than in the central‐northern Okinawa Trough might be caused by the thick sediment covering due to the Taiwan orogenic uplift. (b) Heat flow can be enhanced dramatically by mantle upwelling, but magma intrusion accompanied by ascending fluid is necessary for the extremely high heat flow along the central Okinawa Trough axis. A magma intrusion age of 0.5 Ma, an intrusion depth of 1 km, and a fluid flow speed in the magma of 9 cm/year are the best fit parameters for the central Okinawa Trough. (c) Given the distribution of heat flow, we suggest that the evolutionary model differs between the central‐northern and the southern Okinawa Trough. The rifting in the central‐northern Okinawa Trough began at 10 Ma with a mean rate of 0.4 cm/a, while the rifting in the south Okinawa Trough started at 6 Ma with a higher rate of 0.6 cm/a. (d) A double magma chamber may exist underneath the axis of the Okinawa Trough at depths of 10 and 24–30 km beneath the seafloor. The temperatures and pressures at these depths support the existence of partial melting, which became the primary basis for maintaining the extremely high heat flow currently observed in the Okinawa Trough.

Core network function placement in self-deployable mobile networks

Emerging mobile network architectures (e.g., aerial networks, disaster relief networks) are disrupting the classical careful planning and deployment of mobile networks by requiring specific self-deployment strategies. Such networks, referred to as self-deployable, are formed by interconnected rapidly deployable base stations that have no dedicated backhaul connection towards a traditional core network. Instead, an entity providing essential core network functionalities is co-located with one of the base stations. In this work, we tackle the problem of placing this core network entity within a self-deployable mobile network, i.e., we determine with which of the base stations it must be co-located. We propose a novel centrality metric, the flow centrality, which measures a node capacity of receiving the total amount of flows in the network. We show that in order to maximize the amount of exchanged traffic between the base stations and the core network entity, under certain capacity and load distribution constraints, the latter should be co-located with the base station having the maximum flow centrality. We first compare our proposed metric to other state of the art centralities. Then, we highlight the significant traffic loss occurring when the core network entity is not placed on the node with the maximum flow centrality, which could reach 55% in some cases.

Macrobenthic community structure and influence on denitrification capacity in soft sediments (Mobile Bay, Alabama, USA)

Benthic macrofauna play important roles in coastal ecosystems through their impact on nutrient cycling and by serving as an important trophic link. This study investigated the influence of environmental stressors on macrofaunal community abundance, biomass and diversity and evaluated impacts of those benthic organisms on nutrient fluxes and denitrification capacity in Mobile Bay, a shallow subtropical estuary in the northern Gulf of Mexico. Between January and May 2016, 22 stations in the lower bay were sampled, and the distance from the sea and sediment characteristics were identified as the principal constraints for macrofaunal distribution and taxonomic composition. Higher diversity of macrofauna was found near the mouth of the bay, likely due to hydrological characteristics of the bay, in addition to distance from anthropogenic disturbances near coasts. Sediments comprised of 60-80% sand showed higher abundances, biomass and diversity compared to muddier or sandier sediments, potentially because these sediments were more stable. Although macrofaunal abundance, biomass and diversity differed across stations in the bay, we did not find a relationship between macrofaunal abundances or biomass and denitrification capacity. Both abundance and biomass of infauna were low in Mobile Bay (\textless4000 ind. m(-2) and \textless5 g DW m(-2) at most sites) compared to those in previous studies which showed a positive relationship between macrofaunal abundances and denitrification. The lack of the relation between macrofauna and denitrification suggests that a threshold of abundance, biomass and/or burrowing activity is necessary to increase bioturbation or irrigation to sufficient levels to affect denitrification.

The Baum–Welch algorithm with limiting distribution constraints

We present a method of incorporating limiting distribution information in the Baum–Welch algorithm for estimating parameters of discrete-time, finite-state, Hidden Markov Models. We find that having, even imperfect, limiting distribution information can dramatically improve transition probability estimates. Additionally, we find that when (1) the underlying process is weakly correlated with the observable signal, and (2) the length of the data sequence is short, the additional information provided by the limiting distribution is substantial.

Finding the most influential product under distribution constraints through dominance tests

Market analysis is crucial for companies to remain invincible in the increasingly fierce market competition. A typical application is to find the most influential product, which attracts the largest number of customers, from a collection of candidate products. Previous work assumes a random distribution of the candidates. However, in many cases, there is a set of constraints on the distribution of candidate products. In this paper, we study the most influential product problem under constraints of the distribution. We model the constraints as both non-linear and linear constraints, where the candidate products reside in a hyper-rectangle and hyper-plane of the data space, respectively. We capitalize on reverse skyline queries to define the most influential product as the product with the largest reverse skyline set. We propose a general framework to solve the problem efficiently by taking advantage of candidate distributions. More specifically, we introduce a constraint-based filtering scheme, which prunes searching space and enables quick identification of some reverse skyline points, through pre-processing based on distribution constraints. We also propose a distance-based ordering technique, such that the processing results of a candidate can be utilized for data pruning of subsequent candidates. By combining the filtering scheme and ordering technique, we present two algorithms for handling different constraint models. Our experimental results with both real and synthetic datasets demonstrate the effectiveness and efficiency of our proposed algorithms.

A Simple Empirical Likelihood Ratio Test for Normality Based on the Moment Constraints of a Half-Normal Distribution

A simple and efficient empirical likelihood ratio (ELR) test for normality based on moment constraints of the half-normal distribution was developed. The proposed test can also be easily modified to test for departures from half-normality and is relatively simple to implement in various statistical packages with no ordering of observations required. Using Monte Carlo simulations, our test proved to be superior to other well-known existing goodness-of-fit (GoF) tests considered under symmetric alternative distributions for small to moderate sample sizes. A real data example revealed the robustness and applicability of the proposed test as well as its superiority in power over other common existing tests studied.

Occurrence of Christella (Thelypteridaceae) in Southwest China and its indications of the paleoenvironment of the Qinghai–Tibetan Plateau and adjacent areas

AbstractThe uplift of the Qinghai–Tibetan Plateau dramatically changed the regional topography and climate, profoundly impacting the distribution of many plant lineages. Plant responses to environmental changes are particularly prominent in lineages that require ecological factors differentiated from those present before the uplift of the QTP. Two fossil occurrences of Christella H. Lév., Fl. Kouy–Tchéou (Thelypteridaceae), a fern genus now distributed mainly at low elevations of the pantropics with warm and moist habitats, are described based on fossilized Cenozoic leaf fronds recovered from SW China: late Paleocene Christella nervosa (J. R. Tao) C. L. Xu, T. Su & Z. K. Zhou comb. nov. found in Liuqu, southern Tibet and middle Miocene Christella sp. recovered from the Jinggu Basin in western Yunnan. The frond fossils from both sites share key morphological characteristics that diagnose these fossils as Christella. After detailed comparisons, we further clarified Christella papilio (C. Hope) Holttum, a species distributed in warm, humid habitats at altitudes no more than 1300 m, as the nearest living relative of C. nervosa. This finding suggested that southern Tibet had not reached its present elevation during the late Paleocene (ca. 56 Ma). We propose that the uplift, accompanied by severe cooling and aridification after the late Paleocene, caused the disappearance of Christella in southern Tibet, whereas paleoenvironmental conditions enabled the genus to survive in Yunnan. Our study provides the first example of distributional constraints of ferns in SW China in response to paleoenvironmental changes in the Qinghai–Tibetan Plateau and nearby areas.

Beyond Moments: Extending the Maximum Entropy Principle to Feature Distribution Constraints.

The maximum entropy principle introduced by Jaynes proposes that a data distribution should maximize the entropy subject to constraints imposed by the available knowledge. Jaynes provided a solution for the case when constraints were imposed on the expected value of a set of scalar functions of the data. These expected values are typically moments of the distribution. This paper describes how the method of maximum entropy PDF projection can be used to generalize the maximum entropy principle to constraints on the joint distribution of this set of functions.

Strategies of Distribution Effectiveness of Special Physical Allocation Funds in The Field of Marine And Fisheries

Indonesia still has tremendous opportunities to utilize and develop the potential of fisheries optimally. The government through DAK Marine and Fisheries Sector helps fund the physical development activities in the field of marine and fisheries to support fishery production. The effectiveness of DAK disbursement from the government to various regions becomes very important to accelerate the process of marine and fisheries development. The purposes of this research are as follows: (1) analyzing the constraints of DAK Marine and Fisheries Sector distribution; (2) analyzing the impact of DAK Marine and Fisheries Sector distribution; and (3) formulating the strategies needed to improve the effectiveness of DAK Marine and Fisheries Sector distribution. The processing techniques and data analysis in this research included data panel data regression analysis with Fixed Effect Model (FEM) method using Eviews 8 software and analysis of strategy formulation using Strengths - Weakness – Opportunities – Threats (SWOT) matrix. Based on the results of Regression, DAK Fishing Capture variables have no significant effects on Capture Fishery Production, while DAK Fishery Aquaculture variables have significant effects on Aquaculture Production. The results of formulation of alternative strategies using SWOT matrix exhibit the position point of IFE and EFE score points at the quadrant position III (Turn Around). The recommended strategy is the WO strategy i.e. to minimize the weaknesses to take advantages of opportunities. Keywords: DAK KP, effectiveness, FEM, SWOT Matrix, WO strategy

Semiparametric Bayesian analysis for longitudinal mixed effects models with non-normal AR(1) errors

This paper studies Bayesian inference on longitudinal mixed effects models with non-normal AR(1) errors. We model the nonparametric zero-mean noise in the autoregression residual with a Dirichlet process (DP) mixture model. Applying the empirical likelihood tool, an adjusted sampler based on the Polya urn representation of DP is proposed to incorporate information of the moment constraints of the mixing distribution. A Gibbs sampling algorithm based on the adjusted sampler is proposed to approximate the posterior distributions under DP priors. The proposed method can easily be extended to address other moment constraints owing to the wide application background of the empirical likelihood. Simulation studies are used to evaluate the performance of the proposed method. Our method is illustrated via the analysis of a longitudinal dataset from a psychiatric study.

Adopting feature resolution and material distribution constraints into topology optimisation of additive manufacturing components

ABSTRACTAdditive manufacturing (AM), known for its ability to manufacture complex shapes, is becoming an essential companion of topology optimisation (TO) to optimise the structure. However, the topology-optimised structure may result in suboptimal performance or even have features, which are difficult to manufacture in a given AM process. This study attempts to refine the outcome from TO with AM-specific considerations, such as minimum feature resolution and material continuity-related constraints by introducing a neighbourhood density function, subsequent to the solid isotropic material with penalisation approach. The four different cases have been studied to demonstrate the effectiveness of the presented approach yielding better results when compared with the conventional TO under the three-point bending test. The current study provides optimised geometry with the decreased number of voids and ensuring the minimum feature size without substantial loss in the structural behaviour and becomes the basic framework to integrate manufacturability into structural TO for the AM process.

Multi-View Missing Data Completion

A growing number of multi-view data arises naturally in many scenarios, including medical diagnosis, webpage classification, and multimedia analysis. A challenge in learning from multi-view data is that not all instances are fully represented in all views, resulting in missing view data. In this paper, we focus on feature-level completion for missing view of multi-view data. Aiming at capturing both semantic complementarity and identical distribution among different views, an Isomorphic Linear Correlation Analysis (ILCA) method is proposed to linearly map multi-view data to a feature-isomorphic subspace through learning a set of excellent isomorphic features, thereby unfolding the shared information from different views. Meanwhile, we assume that missing view obeys normal distribution. Then, the missing view data matrix can be modeled as a low-rank component plus a sparse contribution. Thus, to accomplish missing view completion, an Identical Distribution Pursuit Completion (IDPC) model based on the learned features is proposed, in which the identical distribution constraint of missing view to the other available one in the feature-isomorphic subspace is fully exploited. Comprehensive experiments on several multi-view datasets demonstrate that our proposed framework yields promising results.

Persistence of spatial meanings in the conceptualization of causality: at, by, with and about in emotion constructions

Abstract Prepositions encode various causal forces when expressing emotion causality in emotion constructions. This study investigates two pairs of prepositions, the zerodimensional at and by, and the two- or three-dimensional with and about, which show contrasting collocation patterns in emotion constructions. Through a corpus analysis of the Corpus of Contemporary American English, this study claims that there is a strong tendency that zero-dimensional prepositions are used with short-term emotions, whereas two- or three-dimensional prepositions frequently occur with long-term emotions. This study argues that the constraints of distributions of prepositions with emotive adjectives can be accounted for by features of their spatial source meanings in early usages. In the framework of grammaticalization, the constraints of collocation patterns of two pairs of prepositions with emotive adjectives show the phenomenon with respect to the “persistence” of Hopper (1991) in which traces of the source lexemes are retained in the constraints of their distributions. This study is significant in that it suggests a typology of causality based on spatial dimensions of prepositions.

Toward broadband, dynamic structuring of a complex plasmonic field.

The ability to tailor a coherent surface plasmon polariton (SPP) field is an important step toward many new opportunities for a broad range of nanophotonic applications. Previously, both scanning a converging SPP spot and designing SPP profiles using an ensemble of spots have been demonstrated. SPPs, however, are normally excited by intense, coherent light sources, that is, lasers. Hence, interference between adjacent spots is inevitable and will affect the overall SPP field distributions. We report a reconfigurable and wavelength-independent platform for generating a tailored two-dimensional (2D) SPP field distribution by considering the coherent field as a whole rather than as individual spots. With this new approach, the inherent constraints in a 2D coherent field distribution are revealed. Our design approach works not only for SPP waves but also for other 2D wave systems such as surface acoustic waves.

Designing matching mechanisms under constraints: An approach from discrete convex analysis

We consider two-sided matching problems where agents on one side of the market (hospitals) are required to satisfy certain distributional constraints. We show that when the preferences and constraints of the hospitals can be represented by an M♮-concave function, (i) the generalized Deferred Acceptance (DA) mechanism is strategyproof for doctors, (ii) it produces the doctor-optimal stable matching, and (iii) its time complexity is proportional to the square of the number of possible contracts. Furthermore, we provide sufficient conditions under which the generalized DA mechanism satisfies these desirable properties. These conditions are applicable to various existing works and enable new applications as well, thereby providing a recipe for developing desirable mechanisms in practice.

Stability and strategy-proofness for matching with constraints: A necessary and sufficient condition

Distributional constraints are common features in many real matching markets, such as medical residency matching, school admissions, and teacher assignment. We develop a general theory of matching mechanisms under distributional constraints. We identify the necessary and sufficient condition on the constraint structure for the existence of a mechanism that is stable and strategy-proof for the individuals. Our proof exploits a connection between a matching problem under distributional constraints and a matching problem with contracts.

Finite Element Analysis and Experimental Simulation of Chassis Mounted Platform for Off-Road Wheeled Combat and Transport Utility Vehicles

Chassis mounted platform is an intermediate component between vehicle chassis and chassis mounted shelter, and is intended to act as a levelled base for shelters. Shelters in combat vehicles provide a closed stipulated environment to computerized tracking systems, sophisticated defense combat equipments to suit the operational and environmental requirements during warhead situations. Platform carries transfers and sustains unevenness in load arising from the road or soil irregularities during off-road vehicle travel. Present work deals with development, evaluation and improvement of one such platform for 8x8 vehicles. In this work, the platform under consideration is designed to accommodate two shelters, each being secured to the platform using standard twist locking arrangements. Securing locations are dependent on the size and weight of the commodity to be placed inside shelter. Major design ruminations of the platform include nature and pattern of load, flange orientations of channel sections, span between webs of consecutive channels, axle load distribution and vehicle geometry constraints as ground clearance and departure angle. Finite element analysis is carried out in to order evaluate stress and deflection in the present platform configuration. Experimental strain measurement at critical locations on the platform is carried at Automotive Research Association of India (ARAI) to evaluate the performance of the platform under specified load-speed conditions. Relation between experimental stress values and strain gauge locations on the platform is assessed for different load magnitudes.

Range-constrained co-occurrence simulation reveals little niche partitioning among rock-dwelling Montenegrina land snails (Gastropoda: Clausiliidae).

AimTaxon co‐occurrence analysis is commonly used in ecology, but it has not been applied to range‐wide distribution data of partly allopatric taxa because existing methods cannot differentiate between distribution‐related effects and taxon interactions. Our first aim was to develop a taxon co‐occurrence analysis method that is also capable of taking into account the effect of species ranges and can handle faunistic records from museum databases or biodiversity inventories. Our second aim was to test the independence of taxon co‐occurrences of rock‐dwelling gastropods at different taxonomic levels, with a special focus on the Clausiliidae subfamily Alopiinae, and in particular the genus Montenegrina.LocationBalkan Peninsula in south‐eastern Europe (46N–36N, 13.5E–28E).MethodsWe introduced a taxon‐specific metric that characterizes the occurrence probability at a given location. This probability was calculated as a distance‐weighted mean of the taxon's presence and absence records at all sites. We applied corrections to account for the biases introduced by varying sampling intensity in our dataset. Then we used probabilistic null‐models to simulate taxon distributions under the null hypothesis of no taxon interactions and calculated pairwise and cumulated co‐occurrences. Independence of taxon occurrences was tested by comparing observed co‐occurrences to simulated values.ResultsWe observed significantly fewer co‐occurrences among species and intra‐generic lineages of Montenegrina than expected under the assumption of no taxon interaction.Main conclusionsFewer than expected co‐occurrences among species and intra‐generic clades indicate that species divergence preceded niche partitioning. This suggests a primary role of non‐adaptive processes in the speciation of rock‐dwelling gastropods. The method can account for the effects of distributional constraints in range‐wide datasets, making it suitable for testing ecological, biogeographical, or evolutionary hypotheses where interactions of partly allopatric taxa are in question.

Ordination classification of relationship of vegetation and soil’s edaphic factors along the roadsides of Wahcantt, Pakistan

Vegetation and soil had reciprocal interrelated effects over each other. For this purpose, a study was carried along roadsides of WahCantt to determine relationship between vegetation and soil’s edaphic factors using ordination classification. Herbaceous data was collected using Braun Blanquet approach which identified 18 species of 36 families with Cynodon dactylon as the most dominant species. Relationship between soil’s edaphic factors (Zn2+, Cu2+, Fe2+, Mn2+, O.M, EC, pH) and species richness was determined using CCA. The dominant species of Cynodon dactylon was found to be only affected by EC. T-value biplots were employed to identify the response of herbaceous species against selected soil’s edaphic factors and Partial ordination for variation portioning of species against every edaphic factor. CCA had highlighted Zn2+ as the most influencing factor over the species distribution while Mn and O.M had no impact over species richness. T-value biplot of Fe2+ was found to be positively affecting the abundant species of Cynodon dactylon whereas no species had recorded its response against Mn and O.M. Cynodon dactylon was emerged to be least emerged species in bivariate scatter plots of partial ordination. The study highlighted the interrelationship between soil’s edaphic factor and herbaceous flora which would be helpful in determining limiting constraint in species distribution.