In this paper a direct method based on a transcription by Finite Elements in Time has been used to design optimal interplanetary trajectories, exploiting a combination of gravity assist maneuvers and low-thrust propulsion. A multiphase parametric approach has been used to introduce swing-bys among thrust and coast arcs. Gravity maneuvers are at first modeled with a link-conic approximation and ...

Traffic matrix (TM) is extremely important in many networking operations. This paper proposes a novel approach of TM estimation in large-scale IP networks, termed as Advanced-Tomogravity method, which is based on a precise gravity model and the tomography method. First, the precise gravity model is proposed on the basis of the existing generalized gravity model by introducing a relativity facto...

Based on the introduction of the concepts of logistics and logistics center, this paper analyzed the status and problems of Jilin Province’s logistics center, and proposed the steps, principles and factors for site selection of logistics center. Then by listing and comparing nine kinds of logistics center site selection method, including Analytic Hierarchy Process, Cluster Algorithm, Genetic Al...

Background: Accumulation of pleural and peritoneal fluid is seen in some diseases. In order to diagnose the disease and start the treatment, one of the most important actions will be to differentiate between exudates and transudates. The objective of this study was to determine the diagnostic value of measuring the specific gravity of the fluid through...

gravity acceleration data have grand pursuit for marine applications. due to environmental effects, marine gravity observations always hold a high noise level. in this paper, we propose an approach to produce marine gravity data using satellite altimetry, high-resolution geopotential models and harmonic splines. on the one hand, harmonic spline functions have great capability for local gravity ...

A hybrid meta-heuristic optimization method is introduced to efficiently find the optimal shape of concrete gravity dams including dam-water-foundation rock interaction subjected to earthquake loading. The hybrid meta-heuristic optimization method is based on a hybrid of gravitational search algorithm (GSA) and particle swarm optimization (PSO), which is called GSA-PSO. The operation of GSA-PSO...

In 1930 Moore and Van Slyke (1) reviewed the various physical measurements, refractometric and others, that might serve as measures of the protein concentration of plasma, and concluded that specific gravity was the most reliable if application was required to pathological as well as normal plasmas. For plasma of nephritic patients they found that the relation between protein concentration and ...

various sources of geodetic, geological and geophysical information can improve our understanding about the crustal density. in this paper we propose a methodology for determination of crustal density based on terrestrial gravity observations, geopotential models, digital terrain models (dtm), geological maps and cross-sections, deep geophysical profiles, and geoid models. the method can be alg...