Artificial Obstacles Research Articles

CLOSE-RANGE MINI-UAVS PHOTOGRAMMETRY FOR ARCHITECTURE SURVEY

Abstract. The survey of historical façades contains several bottlenecks, mainly related to the geometrical structure, the decorative framework, the presence of natural or artificial obstacles, the environment limitations. Urban context presents additional restrictions, binding by ground acquisition activity and leading to building data loss. The integration of TLS and close-range photogrammetry allows to go over such stuff, not overcoming the shadows effect due to the ground point of view. In the last year the massive use of UAVs in survey activity has permitted to enlarge survey capabilities, reaching a deeper knowledge in the architecture analysis. In the meanwhile, several behaviour rules have been introduced in different countries, regulating the UAVs use in different field, strongly restricting their application in urban areas. Recently very small and light platforms have been presented, which can partially overcome these rules restrictions, opening to very interesting future scenarios. This article presents the application of one of these very small RPAS (less than 300 g), equipped with a low-cost camera, in a close range photogrammetric survey of an historical building façade in Bologna (Italy). The suggested analysis tries to point out the system accuracy and details acquisition capacity. The final aim of the paper is to validate the application of this new platform in an architectonic survey pipeline, widening the future application of close-range photogrammetry in the architecture acquisition process.

GEOMETRIC MODELLING OF RAILWAYS SPATIAL TRANSITION CURVE

Context. The problem of geometric modelling of transitional curves, which are placed between rectilinear and circular sections of railway tracks, can be considered solved sufficiently. However, there are a number of factors that contribute to the development of new methods for modelling these important sections of the railway tracks. The main of them are the increase in the speed of the train, the increase in their mass, the limited size of the territory on which the railway is built, etc. The importance of this issue is greatly increased when laying rails in a mountainous area, when trains have to overcome the ups and downs, bend around natural and artificial obstacles. Under these conditions, the transition curves acquire a spatial character.Objective. Further development of the method of geometric modelling of spatial transition curves, which are placed between rectilinear and circular sections of railway tracks located in two parallel planes.Method. Transitional sections of the railway track are modelled using parametric curves, in which the length of the curve arc is taken as the parameter. To close the mathematical model of the transition curves, it is assumed that the curvature of the curve is subject to a polynomial dependence of the fourth degree, and torsion to the second degree. The unknown coefficients of these polynomial dependencies, which are necessary for calculating the coordinates of the simulated transition curves, are determined by a numerical method, in particular, by minimization of the functional for which the deviation of the intermediate obtained final point of the transition curve from the given one is accepted.Results. On the basis of the proposed theoretical proposition, a program code for calculating and visualizing spatial transition curves providing a smooth transition from rectilinear sections of a railway track to a circular one is developed, provided that both these sections are in parallel planes.Сonclusions. A new method is proposed for modelling the spatial transition curves of railway tracks, which are laid on the terrain with a complex relief. Practical implementation of many variants of spatial transition curves placed between the rectilinear and circular sections of the railway track has proved the operability of the method of their geometric modelling.

Wind Tunnel Experiments: Influence of Erosion and Deposition on Wind-Packing of New Snow

Wind sometimes creates a hard, wind-packed layer at the surface of a snowpack. The formation of such wind crusts was observed during wind tunnel experiments with combined SnowMicroPen and Microsoft Kinect sensors. The former provides the hardness of new and wind-packed snow and the latter spatial snow depth data in the test section. Previous experiments showed that saltation is necessary but not sufficient for wind-packing. The combination of hardness and snow depth data now allows to study the case with saltation in more detail. The Kinect data requires complex processing but with the appropriate corrections, snow depth changes can be measured with an accuracy of about 1 mm. The Kinect is therefore well suited to quantify erosion and deposition. We found that no hardening occurred during erosion and that a wind crust may or may not form when snow is deposited. Deposition is more efficient at hardening snow in wind-exposed than in wind-sheltered areas. The snow hardness increased more on the windward side of artificial obstacles placed in the wind tunnel. Similarly, the snow was harder in positions with a low Sx parameter. Sx describes how wind-sheltered (high Sx) or wind-exposed (low Sx) a position is and was calculated based on the Kinect data. The correlation between Sx and snow hardness was -0.63. We also found a negative correlation of -0.4 between the snow hardness and the deposition rate. Slowly deposited snow is harder than a rapidly growing accumulation. Sx and the deposition rate together explain about half of the observed variability of snow hardness.

TECHNICS AND STAGES OF WORK ORGANIZATION IN THE TRENCHLESS LAYING OF PIPELINES USING MICROTUNNELLING TECHNOLOGIES

The authors describe technics and stages of work organization in the construction of pipeline crossings through natural and artificial obstacles and construction of underground engineering communications of urban purpose using microtunnelling technologies. The essence of this technology is the penetration in the soil carried out by a tunnelling machine (microscope), the translational motion of which is provided by a powerful jack station, installed in the pit at a depth that corresponds to the depth of laying of the pipeline. The depth of laying of the pipeline should be in stable soils not less than two diameters, and in unstable soils – not less than three diameters from the surface of the earth to the upper creature pipeline. With the help of hydraulic jacks, the microchip is driven into the ground by a length corresponding to the length of the pipe sections used, after which the next pipe is installed on the jack station and the process is repeated. The types of microtunnel tunnelling complexes depending on the system of soil removal and bottomhole load are presented. The technological process of preparation and regeneration of the bentonite solution injected over the shell of the tunnelling machine and the forcing pipe sections to ensure the stability of the bottomhole and reduce the frictional forces between the pipeline and the soil and supplied into the bottomhole area for transportation of the developed soil from the bottomhole is considered. The technique of calculating the required punching force of pipe sections on a rectilinear section to be created by a jack station is proposed. The schemes of arrangement and principles of operation of the three modules (electronic laser system ELS, electronic laser system with hydrostatic water levelling ELS-HWL and gyro navigation system with a pointer to the north GNS-P) of the developed by Herrenknecht AG company for standardization of precise navigation in microtunnelling regardless of the length of the tunnel, its diameter and direction universal navigation system UNS are considered. The main advantages of microtunnelling are precisely in the direction of the plan and the profile (deviation from the design axis within 10-30 mm), fast (average rolling speed is 10-15 m / day) and with the minimum amount of subsidence of the daily surface (does not exceed 10 mm) construction of pipelines in combination with the possibility of laying both a rectilinear and complex curvilinear trajectory, at large depths (up to 100 m) and at considerable distances (up to 1000 m), in the whole range of engineering-technological and hydrogeological conditions.

Gerrymandering and Conceit: The Supreme Court's Conflict With Itself

In November 2016, a federal court struck as unconstitutional Wisconsin’s redistricting map under both the First Amendment and the Equal Protection Clause. The court’s decision in Whitford v. Gill marks the first time a federal court invalidated a redistricting map as unconstitutional for partisan gerrymandering in over thirty years. Wisconsin has appealed the decision to the United States Supreme Court, which recently granted review. The Supreme Court has long held that extreme partisan gerrymandering violates equal protection but has simultaneously refused to determine the merits of gerrymandering disputes, instead labeling them as non-justiciable political questions. In particular, the Court has maintained that no manageable standard yet exists by which the Court could implement the promise of equal protection to partisan redistricting. This Article analyzes the manageable standard requirement, revealing the Court’s failure to define the term and that the Court has applied the manageability requirement haphazardly. Scores of court-made standards either over- or under-enforce the constitutional norm they purport to implement. Why is “fairness” a workable standard in one context but not another? How are standards that measure one’s shocked conscious, or weigh the totality of the circumstances judicially manageable? Importantly, a common thread connects the Court’s use of the manageability requirement to its insecurity in exercising judicial review, indicating that the Court often applies the manageability requirement when particularly insecure in exercising the judicial function. Recast in this light, the question of Court engagement in gerrymandering disputes turns on the propriety of Court intervention to address artificial obstacles that disrupt democratic functionality. The Court should no longer hide behind the manageability barrier because court intervention to ensure democracy’s proper functioning was (1) anticipated by the Framers, (2) memorialized in the Constitution’s form and structure, and (3) exercised by the Court without loss of judicial legitimacy in analogous contexts. This Article posits that judicial intervention to unblock the avenues of political change is one of the Court’s central responsibilities, that in similar contexts the Court has recognized as much, and that it should do so again in Whitford.

Comment on the Request for Information on Rulemaking Processes by the Consumer Financial Protection Bureau, CFPB Docket No. CFPB-2018-0009

On March 7, 2018, the Consumer Financial Protection Bureau, under Acting Director Mick Mulvaney, issued a Request for Information eliciting public comment on its rulemaking processes. This response expresses concern that under its new leadership, the Bureau is retreating from its commitment to fair, open, and data-driven rulemakings in response to industry pressure. The response argues that the Bureau must refrain from any actions that would undermine that commitment, including: (1) creating artificial obstacles to on-boarding quantitative data; (2) prohibiting the use of qualitative data and consumer anecdotes; (3) compromising the independence of its cost-benefit analyses; and (4) relying on new data, studies or reports after a Notice of Proposed Rulemaking appears without disclosing that reliance. The response further calls on the Bureau to strengthen its ex parte policy to ensure timely public posting of all ex parte communications involving rulemakings.

Longitudinal connectivity loss in a riverine network: accounting for the likelihood of upstream and downstream movement across dams

Disruption of longitudinal connectivity is a major concern in most of the world´s rivers. Approaches based on graph theory have proven to be a suitable tool for analysing functional connectivity. However, previous applications of graph-based connectivity methods to river systems have been oversimplified in that they have treated potential barriers as binary features and rivers as symmetric networks. We here apply a network analytical approach in which (a) upstream and downstream connectivity are considered so that fish passability values across dams are asymmetrical, and (b) it is possible to consider a continuous range of passability values for every dam. We build on previous and widely used connectivity metrics (Probability of Connectivity, PC), which here are generalised and adapted toward that end. We compare the results of our approach with those that would be obtained under the more simplified assumptions of symmetric movement and of barriers as binary features. We want to prove if there are substantial differences between considering or not the asymmetry in river networks. The application of symmetrical and asymmetrical PC highlights major differences between the upstream connectivity versus the downstream connectivity. We provide our methods in a free software package so that they can be used in any other application to riverscapes. We expect to provide a better graph-based approach for the prioritisation of the removal or permeabilization of artificial obstacles as well as for the preservation of target river segments for connectivity conservation and restoration.

Corruption as obstacle for effective logistics of modern clusters

The purpose of the article is to study the artificial obstacles that emerge in organisational and functional spheres of activities of logistic clusters; to conduct conceptual and methodological development of methodological foundations of formation and implementation of scientifically substantiated logistic instrumentarium of mobilisation of continuous processes; to develop the concept of logistic analysis of market environment and determine links that are capable of effectively manifesting them in realisation of import substitution programs. The authors have scientifically substantiated that the emergence of artificial obstacles in functioning and development of modern clusters complicates their virtual structure, leading to additional expenditures of time and financial character, thus extending and increasing in price logistic reproduction cycles of integration entities, hindering successful and effective cooperation of members of cluster entities and integration of members, and expanding the limits of continuous cooperation.

Uticaj karakteristika vodenih prepreka na pripremu i izvođenje napadne operacije kopnene vojske

The impact of natural and artificial obstacles on the execution of modern combat operations is enormous. Finding a way to make the operational units more independent of the equipment for water obstacles remains an enigma for the materiel constructors. The paper presents the impact of the characteristics of water obstacles on the preparation and execution of the Land Forces offensive operation in terms of the selection of materiel and the location for crossing water obstacle. The selection of the location for crossing water obstacle has been made by implementation of one of the methods of multi-attribute decision-making, that is the method of linear ranking. The linear ranking method has been used in combination with the scheduling method. The paper emphasizes the importance of implementing multiple-criteria decision-making methods in the military decision-making process.

Corruption as Obstacle for Effective Logistics of Modern Clusters

The purpose of the article is to study the artificial obstacles that emerge in organisational and functional spheres of activities of logistic clusters; to conduct conceptual and methodological development of methodological foundations of formation and implementation of scientifically substantiated logistic instrumentarium of mobilisation of continuous processes; to develop the concept of logistic analysis of market environment and determine links that are capable of effectively manifesting them in realisation of import substitution programs. The authors have scientifically substantiated that the emergence of artificial obstacles in functioning and development of modern clusters complicates their virtual structure, leading to additional expenditures of time and financial character, thus extending and increasing in price logistic reproduction cycles of integration entities, hindering successful and effective cooperation of members of cluster entities and integration of members, and expanding the limits of continuous cooperation.

Why do players buy in-game content? An empirical study on concrete purchase motivations

Selling in-game content has become a popular revenue model for game publishers. While prior research has investigated latent motivations as determinants of in-game content purchases, the prior literature has not focused on more concrete reasons to purchase in-game content that stem from how the games are being designed. We form an inventory of reasons (19) to buy in-game content via triangulating from analyses of top-grossing free-to-play games, from a review of existing research, and from industry expert input. These reasons were operationalized into a survey (N = 519). Firstly, we explored how these motivations converged into categories. The results indicated that the purchasing reasons converged into six dimensions: 1) Unobstructed play, 2) Social interaction, 3) Competition, 4) Economical rationale, 5) Indulging the children, and 6) Unlocking content. Secondly, we investigated the relationship between these factors and how much players spend money on in-game content. The results revealed that the purchase motivations of unobstructed play, social interaction, and economical rationale were positively associated with how much money players spend on in-game content. The results imply that the way designers implement artificial limitations and obstacles as well as social interaction affects how much players spend money on in-game content.

Development of a fish leaping framework for low-head barriers

Leaping is an indispensable part of the upstream spawning migration of a fish species. The natural barriers replaced with artificial dams and obstacles can obstruct the leaping process and destruct the life cycle of fish species, causing their extinction in extreme scenarios. To help design and improve the artificial barriers, many studies have been conducted to model the leaping success of fish species. However, generic results were scarcely obtained to be extended for a wide range of barriers. The main reasons can be identified as the lack of thorough understanding of the interaction between fish locomotion and water flow regime upstream of the investigated barriers. Hence, the aim of this study is to propose a leaping framework compatible with a diverse range of fish species and barriers. This framework includes a detailed hydraulic sub-model as well as locomotion model capable of tracing fish in both water and air environments. The functionality of the proposed framework is further discussed using a selected case study.

Modelling photochemical pollutants in a deep urban street canyon: Application of a coupled two-box model approximation

Air pollution associated with road transport is a major environmental issue in urban areas. Buildings in urban areas are the artificial obstacles to atmospheric flow and cause reduced ventilation for street canyons. For a deep street canyon, there is evidence of the formation of multiple segregated vortices, which generate flow regimes such that pollutants exhibit a significant contrast between these vortices. This results in poor air ventilation conditions at pedestrian level, thereby leading to elevated pollutant levels and potential breaches of air quality limits. The hypothesis of a well-mixed deep street canyon in the practical one-box model approach is shown to be inappropriate. This study implements a simplified simulation of the canyon volume: a coupled two-box model with a reduced chemical scheme to represent the key photochemical processes with timescales similar to and smaller than the turbulent mixing timescale. The two-box model captures the significant pollutant contrast between the lower and upper parts of a deep street canyon, particularly for NO2. Core important parameters (i.e. heterogeneity coefficient, exchange velocity and box height ratio) in the two-box model approach were investigated through sensitivity tests. The two-box model results identify the emission regimes and the meteorological conditions under which NO2 in the lower canyon (i.e. the region of interest for the assessment of human health effects) is in breach of air quality standards. Higher NO2 levels were observed for the cases with higher heterogeneity coefficients (the two boxes are more segregated), with lower exchange velocities (worse ventilation conditions), or with smaller box height ratios (reduced dilution possibly due to secondary smaller eddies in the lower canyon). The performance of a one-box model using the same chemical scheme is also evaluated against the two-box model. The one-box model was found to systematically underestimate NO2 levels compared with those in the lower box of the two-box model for all test scenarios. This underestimation generally tends to worsen for higher heterogeneity coefficients, lower exchange velocities or smaller box height ratios. This study highlights the limitation of the assumption of homogeneity in single box models for street canyon simulation, and the inherent uncertainties that must be borne in mind to appropriately interpret such model output (in particular, that a single-box treatment will systematically underestimate NO2 as experienced at street level).

RECONFIGURATION MULTISENSORY SYSTEM IN CONDITIONS OF IMPACT OF DESTABILIZING FACTORS

In this paper considered the multi-sensor system that consist of a limited number of measurement sensors, communication system and system where displaying the measurement result. Based on the similarity of construction of multi-sensor system and computer network topologies is given analysis of known way transmission of measurement data to a display device. The route of transmission of information from a remote sensor to the control point established for a minimum length of the data transmission path. The measurements under natural and artificial obstacles requires some reconfiguration of the starting topology that adequately analyzed by a "death-reproduction" scheme.

COMPETITION AS A STIMULUS TO IMPROVE QUALITY OF CARE

Goal. To investigate the types, features and principles of competition in health care, their characteristics; objectives of health care providers in competition. Methods. Methods were used: analysis, analogy, deduction, induction, classification, observation, generalization, synthesis. Results. The analysis of the types of studied features and principles of competition in health care, their characteristics; objectives of health care providers in competition. Conclusion. Competition between service providers did not become a stimulus to improve quality of care and cost containment and has not justified hopes which were assigned to this regulatory tool. To improve the structure of medical care necessary to implement a number of legally reinforced activities: 1. To create conditions for the dissemination of information about the results (to facilitate the collection and dissemination of reliable information on the performance of the providers of medical services and prices for their services in all medical conditions, namely: - to establish a procedure for the determination of performance indicators; - to introduce mandatory reporting on the results; - to form the infrastructure for the accumulation and dissemination of information. 2. To improve the methodology of pricing, namely: - to set prices for episodes and cycles of care; - to minimize price discrimination. 3. To stimulate competition at the appropriate level, namely: - to eliminate the artificial obstacles to the integration of different areas of medical practice; - require justification of values at discharge assignments or referrals that contain a certain economic interest. 4. To set standards and rules governing the development and implementation of information technologies and dissemination of information, namely: - to develop standards that ensure interoperability of software and technical means; - to develop standards for registration of medical data; - to improve identification procedures and confidentiality in the use of personal data; - to create incentives for the implementation of information technologies. 5. To establish a system of prevention of medical errors. 6. Modify the strategies and methods of work of health authorities and insurers. 7. To invest in medical and clinical research.

Developing Russia–NATO relations: problemsof arms control and limitations on destabilizing military activities of the Alliance

The article is devoted to some critical aspects of correspondence of the Alliance status to the basic norms of international law. It also centers on specific actual steps of the realization of the NATO long-term strategy of «openness» in interrelations with the existing universal and regional institutionalized regimes of limitations in the sphere of international security and arms control. Special attention is paid to the NATO strategy of abstention from the direct participation in critical processes of negotiations in the sphere of arms control and limitations on destabilizing military activities. The NATO, as an organization of permanent nature, stands for the position of non-responsibility for the compliance of obligations in this sphere by its member-states. Decomposition of these artificial obstacles is an unavoidable condition for the NATO responsible inclusions in processes of arms control and reduction of large-scale military activities within the OCSE competence.

천마 탐지레이더 Limit&STC 조립체 개선을 통한 탐지성능 향상

In this paper, we have described the performance improvement of surveillance radar to prevent damage or malfunction of surveillance radar RF head unit due to the strong reflections caused by artificial obstacles at close range. We have proposed a technique to improve the performance of the RF head unit as a solution to overcome the limitations of the operating system and improve radar performance. We have verified the effectiveness of the improvement by comparing the before and after results applied to actual system.

Impact of dry granular masses on rigid barriers

This work concerns the impact of dry granular masses on rigid artificial obstacles. The authors approached the problem by performing an extensive campaign of numerical analyses with a commercial code based on the discrete element theory. The standard approaches employed to design sheltering structures are exclusively based on the assessment of the Maximum Impact Force (MIF) exerted by the soil mass on the obstacle, and the sheltering structure is usually designed according to simplified pseudo-static approaches. In a previous paper the authors considered the dependence of MIF on the Froude number and on a large series of both geometrical and mechanical parameters. Indeed, the impulsive nature of the force exerted by the soil onto the structure has to be considered in order to optimize the design of this type of structures. For this reason in this paper the evolution with time of the impact force and the mechanics of the phenomenon are investigated.

DOP coefficients in GNSS observations

Integrated GNSS (GPS+GLONASS) satellite measurements carry a number of benefits. The main advantages are especially possibilities of conducting measurements in areas where use of a single satellite system was not impossible so far. In this paper number of visible satellites and DOP coefficients values in terms artificial horizon obstacles were analysed. Paper also discusses benefits of including additional observations from other navigation satellite systems.

Motion planning and posture control of multiple n-link doubly nonholonomic manipulators

SUMMARYThe paper considers the problem of motion planning and posture control of multiple n-link doubly nonholonomic mobile manipulators in an obstacle-cluttered and bounded workspace. The workspace is constrained with the existence of an arbitrary number of fixed obstacles (disks, rods and curves), artificial obstacles and moving obstacles. The coordination of multiple n-link doubly nonholonomic mobile manipulators subjected to such constraints becomes therefore a challenging navigational and steering problem that few papers have considered in the past. Our approach to developing the controllers, which are novel decentralized nonlinear acceleration controllers, is based on a Lyapunov control scheme that is not only intuitively understandable but also allows simple but rigorous development of the controllers. Via the scheme, we showed that the avoidance of all types of obstacles was possible, that the manipulators could reach a neighborhood of their goal and that their final orientation approximated the desired orientation. Computer simulations illustrate these results.