Aspects about bouncing of plough caused by random

In this paper the author deals aspects about the vertical motion (named bouncing) of a tractor with plough mounted on the rear frame, during displacement over the random excitation surface of the agricultural land. Final results of the simulation process, performed on the model of tractor-plough with 3 degree of freedoms, show the difference between digging depth function as velocity motion and longitudinal profile of the terrain. Thus, the deviation of the plough depth from the reference depth is evaluated.

Fractional diffusant model of a multicomponent inhomogeneous gas mixture as a basis for the diffusant approximation

It can be shown that for a correct description of the motion of an inhomogeneous multicomponent mixture of gases, such concepts as a multi-velocity continuum and interpenetrating motion are not enough. This is the basis for the introduction of the concept of “poly-velocity motion”. The reason for the need to use this concept is that to describe the motion of each component of an inhomogeneous mixture, it is necessary to use not one, but two velocity fields. The use of two velocity fields to describe the motion of a mixture component is the basis for constructing a fractional model of the mixture component, in which each component is divided into two fractions. This model serves as the basis for constructing the proposed fractional diffusant model of a multicomponent inhomogeneous gas mixture.

TMA from Cosines of Conical Angles Acquired by a Towed Array

This paper deals with the estimation of the trajectory of a target in constant velocity motion at an unknown constant depth, from measurements of conical angles supplied by a linear array. Sound emitted by the target does not necessarily navigate along a direct path toward the antenna, but can bounce off the sea bottom and/or off the surface. Observability is thoroughly analyzed to identify the ghost targets before proposing an efficient way to estimate the trajectory of the target of interest and of the ghost targets when they exist.

Switching Extended Kalman Filter Bank for Indoor Localization Using Wireless Sensor Networks

This paper presents a new filtering algorithm, switching extended Kalman filter bank (SEKFB), for indoor localization using wireless sensor networks. SEKFB overcomes the problem of uncertain process-noise covariance that arises when using the constant-velocity motion model for indoor localization. In the SEKFB algorithm, several extended Kalman filters (EKFs) run in parallel using a set of covariance hypotheses, and the most probable output obtained from the EKFs is selected using Mahalanobis distance evaluation. Simulations demonstrated that the SEKFB can provide accurate and reliable localization without the careful selection of process-noise covariance.

Study on the interactions between two light particles rising in a vertical channel

In this study, a 2-D lattice Boltzmann method was used to numerically study the interaction between two light particles rising freely in a channel. The influence of the Reynolds number and the density difference between the particles as they rose was studied from the aspects of particle velocity, motion trajectory and motion pattern. The results show that a change of Reynolds number changed the relative position and distance between the particles, and a change in density changed the inertial force of the particles, which affected the interaction between them. Two movement patterns have been revealed: relatively static and a periodic movement pattern. The influence of differing density on the movement period of the particles was also studied.

Scrambling the skin: A psychophysical study of adaptation to scrambled tactile apparent motion

An age-old hypothesis proposes that object motion across the receptor surface organizes sensory maps (Lotze, 19th century). Skin patches learn their relative positions from the order in which they are stimulated during motion events. We propose that reversing the local motion within a global motion sequence (‘motion scrambling’) provides a good test for this idea, and present results of the first experiment implementing the paradigm. We used 6-point apparent motion along the forearm. In the Scrambled sequence, two middle locations were touched in reversed order (1-2-4-3-5-6, followed by 6-5-3-4-2-1, in a continuous loop). This created a double U-turn within an otherwise constant-velocity motion, as if skin patches 3 and 4 physically swapped locations. The control condition, Orderly, proceeded at constant velocity at inter-stimulus onset interval of 120 ms. The 26.4-minute conditioning (delivered in twenty-four 66-s bouts) was interspersed with testing of perceived motion direction between the two middle tactors presented on their own (sequence 3–4 or 4–3). Our twenty participants reported motion direction. Direction discrimination was degraded following exposure to Scrambled pattern and was 0.31 d’ weaker than following Orderly conditioning (p = .007). Consistent with the proposed role of motion, this could be the beginning of re-learning of relative positions. An alternative explanation is that greater speed adaptation occurred in the Scrambled pattern, raising direction threshold. In future studies, longer conditioning should tease apart the two explanations: our re-mapping hypothesis predicts an overall reversal in perceived motion direction between critical locations (for either motion direction), whereas the speed adaptation alternative predicts chance-level performance at worst, without reversing.

Research findings of an relocatable small size pontoon pier interaction with the aquatic medium during its towing

Использование мобильных малогабаритных причалов дает возможность при снижении затрат организовать погрузку лесоматериалов на суда в пунктах отправления с помощью техники лесозаготовителей. Это создает предпосылки для существенного увеличения объемов перевозки лесоматериалов более дешевым водным транспортом, обеспечивает экономическую доступность древесного сырья, основная часть которого находится в удаленных лесных массивах. Предполагается, что при эксплуатации мобильных причалов они нередко будут перемещаться с одного пункта погрузки на другой в условиях небольших рек с помощью судов малой мощности. Для выполнения расчетов, связанных с указанным перемещением, нужны достаточно точные сведения о сопротивлении воды движению причалов при наличии влияния дна. При теоретическом исследовании установили факторы, влияющие на величину сопротивления воды равномерному перемещению причала. Представили соответствующую зависимость в символьном виде. Преобразовали ее, получив зависимость в безразмерном виде. Обосновали возможность исключения из числа определяющих факторов числа Рейнольдса и целесообразность фиксирования факторов, характеризующих форму подводной части причала. Полученное в результате символьное решение - зависимость коэффициента сопротивления воды от относительной глубины и числа Фруда. Опираясь на нее, провели эксперименты на модели с обеспечением физического подобия. По данным эксперимента получена регрессионная модель, позволяющая вычислять коэффициент сопротивления воды равномерному движению причала, а по величине этого коэффициента определять с использованием формулы Ньютона значение силы сопротивления. Анализируя регрессионную модель, установили, что изменение скорости буксировки относительно воды от 0,5 до 1,5 м/с и соответственно числа Фруда приводит к увеличению коэффициента сопротивления на 20…25%. Изменение относительной глубины от 4,0 до 1,5 вызывает увеличение указанного коэффициента на 110…120%. Столь существенное влияние мелководья в данном случае объяснили наличием постепенно сужающей области между днищем причала и дном водоема, что приводит к более значительному увеличению относительной скорости в задней части причала. Полученная информация дает возможность наилучшим образом спланировать мероприятия, связанные с буксировкой причалов от одного пункта перевалки грузов к другому. Appliance of the relocatable small-sized pontoon piers allows to use the logging machinery for loading of the round wood at the sites of shipment. It enables to increase volumes of the timber transportation volumes using relatively unexpensive water transport and provides better access to the raw wood resources placed at the remote wood stands. It is suggested that the mobile pontoon piers will be replaced from one loading site at the small-scale shallow river to another, using the small-sized tugboats. In order to make projections of these towing operations, the reliable information regarding water resistance to the pontoons motion is needed, taking into consideration the low depths conditions. The named circumstances justify necessity of the mentioned research. As a part of the theoretical study, the factors affecting the resistance of water to uniform velocity motion of a pontoon were characterized. The corresponding dependence was presented in the symbolicand dimensionless forms. The reasons for exclusion of the Reynolds number and fixing of the of a pontoon underwater body patterns were justified. The resulting symbolic form establishes dependence of water resistance coefficient from relative depth and the Froude number. Based upon the developed equation, the model experiments were proceeded. The regression model for calculation of the resistance coefficient and consequently, using the Newton equation, the force of hydraulic drag - was developed. Variation of the towing speed (related to water) from 0.5 to 1.5 m/sec. and, consequently, increase of the Froude number, lead to 20…25% raise of the coefficient of resistance. The relative depth decrease from 4.0 to 1.5 causes 110…120% increase of the mentioned coefficient. Such a sufficient impact of shallowness is explained by increase of the relative velocity in the afterbody zone of a pontoon. The acquired information allows to improve planning of towing operations during relocation of the pontoon piers from one loading site to another.

Combinatorial Optimization for Multi-Target Tracking

In tracking-by-detection paradigm for multi-target tracking, target association is modeled as an optimization problem that is usually solved through network flow formulation. In this paper, we proposed combinatorial optimization formulation and used a bipartite graph matching for associating the targets in the consecutive frames. Usually, the target of interest is represented in a bounding box and track the whole box as a single entity. However, in the case of humans, the body goes through complex articulation and occlusion that severely deteriorate the tracking performance. To partially tackle the problem of occlusion, we argue that tracking the rigid body organ could lead to better tracking performance compared to the whole body tracking. Based on this assumption, we generated the target hypothesis of only the spatial locations of person’s heads in every frame. After the localization of head location, a constant velocity motion model is used for the temporal evolution of the targets in the visual scene. Qualitative results are evaluated on four challenging video surveillance dataset and promising results has been achieved.