Street Floor Research Articles

A Study on the Influencing Factors of Children-friendly Walking Space Perception in Elementary Schools

In this paper, based on the concept of child-friendly primary school students aged 7-12 years and their parents as the object, selected five typical primary schools in Shenyang as research cases, conducted social questionnaires and interviews, combined with the existing space problems and children's needs characteristics of the primary school walkable space are divided into children safe evacuation section and activity-friendly section. The SP method was used to obtain the perceptual preferences of children and parents in two virtual learning space segments, and the influencing factors of their perceptual preferences were explored. The results showed that green vision rate, buffer space type, and walking space width were the key factors affecting children's sense of security in the safe evacuation area, and green vision rate had no significant effect on parents' preference choice. In the child-friendly section, color vision, building line rate, building transparency along the street floor, and play space Settings have positive effects on children's comfort, while the interface aspect ratio has no obvious effect on children's comfort.

Street Floor Segmentation for a Wheeled Mobile Robot

In urban cities, the information about the type or class of street floors enables a wheeled mobile robot to perform many tasks ranging from traversability region identification, localization and the choice of wheel control strategy. In this paper, we considered a new task named as street floor segmentation (SFS) using an RGB camera. The SFS can be considered as the generalized problem of the existing traversability region identification problem in urban situations. Our SFS has two special classes for the possible application to the traversability region identification and they are traversable and non-traversable curbs. The SFS using an RGB camera is implemented using a real-time semantic segmentation (SS) network. A booster module named as Dynamic Context-based Refinement Module (DCRM) was developed to enhance the performance of the SFS. Our network was applied to real-world applications, and its validity is demonstrated through experiment.

Automatic Floor Cleaning Robot Using Arduino and Ultrasonic Sensor

The entire floor cleaning robot is divided into several parts, namely consisting of an Ultrasonic Sensor, Motor Shield L298, Arduino Uno microcontroller, Servo, and Dc Motor. This tool works when the Arduino Uno microcontroller processes the ultrasonic sensor as a distance detector and a DC motor as a robot driver, then the DC motor is driven by the Motor Shield L298. When an ultrasonic sensor detects a barrier in front of it, the robot will automatically look for a direction that is not a barrier to the floor cleaning robot. The distance value on the sensor has been determined, that is, when the distance read by the ultrasonic sensor is below 15 cm. The results of testing the value of the ultrasonic sensor distance found different conditions that occur. In a distance of> 15 cm, the condition of the prototype cleaning robot for the road floor cleaning is obtained, while the distance <15 cm, the condition for the prototype of the street floor cleaning robot has stopped.

Physical Characteristics of Entrance Areas of Coss Passage alongside Jl. Agro, Yogyakarta

This study aimed to determine the physical characteristics of the entrance areas of cross passage alongside Jl. Agro, Yogyakarta. This study was a descriptive qualitative research, where the observational cases were determined based on the purposive sampling technique. The research results showed that commercial buildings with a short seatback constructed the wall space around the entrance areas of cross passage. The scale of the road space was formed by a combination of balanced and narrow space affected by the height of the building. Street floor space, signage, and vegetation showed different patterns at each entrance areas of cross passage. As part of street furniture, gate and sculpture turned into a strong identity in the cross-passage area. There were nine entrance areas of cross passage as a case of observation. The nine cases' physical appearance showed the distinctive form of the archipelago and local identity as three different elements bound them: urban village area as a local identity, Mataram ditch as a heritage of the agricultural system, and universities as a generator of activity.

Canopy density effects on particulate matter attenuation coefficients in street canyons during summer in the Wuhan metropolitan area

Abstract Changes in vegetation traits influence the particulate pollution mitigating effects of trees in street canyons; however, it remains unclear whether tree canopy density (i.e. the proportion of the street floor covered by the vertical projection of the tree canopy) promotes or reduces this effect. A 12-day field experiment was conducted in four representative street canyons to examine the mitigating effects of street trees on particulate matter (PM) for PM1, PM2.5, PM4, PM7, PM10, and total suspended particles (TSP) among four canopy density treatments, including (1) open spaces and areas with (2) sparse (≤35%), (3) medium (35–70%) and (4) dense (≥70%) canopy densities. The results showed that canopy density is the dominant vegetation trait that affects PM dispersion, with peak decreases occurring at a canopy density of ~30%. The particulate matter attenuation coefficient (PMAC) indicates the PM reduction capability of trees. The PMAC of each particle size class correlated negatively with canopy density and TSP (

Trees as a Shading System for Streets on the East–West Axis: Computer Simulations for the Selected Geometrical Proportions of Building Developments in Humid Continental Climate

The study is aimed at investigating the possibilities for solar protection provided to the street canyon located on the E–W axis and with the following profiles: shallow (height/width (H/W) = 0.2, 0.6, and 1) and deep (H/W = 2) by two rows of trees located at a distance of 3 m away from southern and northern façades. The research was based on numerical simulation analyses conducted in the Rhinoceros® program, with the application of the Ladybug Tools environmental plugin for a street set in the city of Płock (52° 32′50″N 19°42′00″E) for the day characterized with the highest total intensity of insolation within the year, 7 June, between 8:00 a.m. and 5:00 p.m. The research yielded no differences in terms of shading the surface of the southern façade of streets with low, medium, and high building developments. However, slight differences (40 m²) were noted for the model with highrise building developments (h = 60 m) characterized with a deep section (H/W = 2). The simulation also revealed that the H/W ratio parameter only slightly (0.88%–1.93%) affected the share trees have in shading the street floor, except in the case of very shallow profiles (H/W = 0.2).

Road surface and its center line and boundary lines detection using terrestrial Lidar data

A proper planning and management of roads play an essential role in socio-economic growth of any nation. The information of road and its geometry are used as a benchmark by transportation authorities and other related agencies for evaluating, monitoring and prioritizing new and existing road projects. Over the last few decades, application of three-dimensional (3D) Light Detection and Ranging (LiDAR) data for the study of road features has been widely adopted. In the present study, a new pipeline has been proposed for the detection of road surface and corresponding center line and boundary lines using terrestrial Lidar data. The pipeline includes two basic phases. In first phase, there are four basic steps i.e. conversion of Lidar data into intensity image, detection of candidate road pixels, reconstruction of Lidar data points and connected component analysis. The steps of first phase are performed in order to detect the road surface, whereas in the second phase center line and boundary lines are detected by forming vertical grids at detected road surface. The proposed pipeline has been tested at a terrestrial Lidar data, captured from the Allahabad city, India, with the help of FARO Focus3D X 330 Terrestrial Laser Scanner (TLS). The road surface and corresponding center line and boundary lines of captured data are successfully detected. The completeness and correctness of detected road surface are 93.91% and 96.94% respectively, detecting a precise and detailed street floor that helps in maintaining the pavement by estimating the road surface conditions.

DETECTION OF ROAD CURB FROM MOBILE TERRESTRIAL LASER SCANNER POINT CLOUD

Abstract. The detection of different road furniture such as curb, street floor and sidewalk from point clouds is important in many applications such as road maintenance and city planning. In this paper a pipeline for point cloud processing to detect the road curb from unorganized point clouds captured from a mobile terrestrial laser scanner is proposed. The proposed pipeline utilizes a covariance- based procedure to perform a 3D segmentation of point clouds. Features such as the road curb can be extracted by analyzing the local neighborhood of every point. This is done by computing the surface normal direction and the normalized eigenvalues. These parameters can be used to extract the ground objects, such as curb, street floor and sidewalk. The curb can be isolated from the rest of the ground objects based on the previous parameters in addition to elevation gradient within the local neighborhood. A 2D image processing scheme is also presented to find the curbs as edges in a generated 2D height image. The results show successful detection rates of 78% and 94% using 3D and 2D approaches respectively.

CURB-BASED STREET FLOOR EXTRACTION FROM MOBILE TERRESTRIAL LIDAR POINT CLOUD

Abstract. Mobile terrestrial laser scanners (MTLS) produce huge 3D point clouds describing the terrestrial surface, from which objects like different street furniture can be generated. Extraction and modelling of the street curb and the street floor from MTLS point clouds is important for many applications such as right-of-way asset inventory, road maintenance and city planning. The proposed pipeline for the curb and street floor extraction consists of a sequence of five steps: organizing the 3D point cloud and nearest neighbour search; 3D density-based segmentation to segment the ground; morphological analysis to refine out the ground segment; derivative of Gaussian filtering to detect the curb; solving the travelling salesman problem to form a closed polygon of the curb and point-inpolygon test to extract the street floor. Two mobile laser scanning datasets of different scenes are tested with the proposed pipeline. The results of the extracted curb and street floor are evaluated based on a truth data. The obtained detection rates for the extracted street floor for the datasets are 95% and 96.53%. This study presents a novel approach to the detection and extraction of the road curb and the street floor from unorganized 3D point clouds captured by MTLS. It utilizes only the 3D coordinates of the point cloud.

A Comparative Study of Various Turbulence Models for Simulating Pollutant Dispersion within an Isolated Street Canyon

CFD calculations are carried out using the standard, RNG and realizable κ-ε turbulence models to simulate the airflow and pollutant dispersion inside an isolated street canyon. The computed air velocity vector fields and pollutant concentration contours show that all the three studied κ-ε models produce a very similar clockwise vortex structure that carries the pollutants released from the line source on the street floor towards the leeward side of the canyon. The calculated non-dimensional pollutant concentration distributions on both the leeward and windward walls of the canyon are compared with the wind tunnel measured data. It is revealed that (1) on the windward wall of the canyon, the calculated pollutant concentrations using the standard, RNG and realizable κ-ε models are all in perfect agreement with the experimental observations, (2) the RNG and realizable κ-ε models provide almost the same results for pollutant concentration distributions on the leeward wall of the canyon, (3) the RNG and realizable κ-ε models overestimate greatly the pollutant concentration values on the leeward wall of the canyon, whereas the concentration distributions predicted by the standard κ-ε model on the leeward wall are in reasonable agreement with the wind tunnel data.

Glassceramics obtained from industrial waste

Abstract Large areas of Latvia are contaminated with industrial waste: metallurgical slag, fly-ash, etching refuse, peat, and coal ash as well as glass waste which often contain dangerous substances. From the environmental point of view this waste should be neutralised. As this waste also contains valuable chemical compounds, it can be considered as a raw material for the generation of new materials. One method of utilisation is to produce recycled materials — street plates, decorative tiles, or floor tiles. Dense sintered glassceramics with a water uptake of 0.34–3.23 wt.%, a final density of 2.93–3.05 g/cm 3 , and a bending strength of 80–96 MPa have been created from industrial waste. The mast chemically durable glassceramics contained clay additions. Thus, the material containing only waste had a durability (mass loss) of 3.02% in 0.1 N HCl, while the composition containing 30% clay addition had a durability of 0.2% in 0.1 N HCl.

Sadness, tragedy and mass disaster in Oklahoma City: providing critical incident stress debriefings to a community in crisis

Shortly after 09:00 h on 19 April 1995, the Alfred P Murrah Federal Building, located in downtown Oklahoma City, was devastated with a bomb blast of such gigantic proportions that it was heard 60 miles away in neighbouring Norman, Oklahoma. Oklahomans routinely commuting to work on that sunny Wednesday morning went about their business as usual. A crude bomb chemically comprised of various organic compounds, chemical fertilizer, ammonium nitrate and diesel fuel, weighing an estimated 4800 pounds or more, was transported in a vehicle the size of a truck. It blew open a crater 6–8 ft deep in the street floor. The Murrah Federal Building was impacted immediately; floors, windows, communication equipment and almost all the innocent victims inside were razed to the ground. Outside the building, as far as 10 blocks away or more, hundreds of victims lay hurt, seriously injured or dead from shards of glass that flew from office windows hundreds of feet above the street floor. Without warning, the initial impact of the bomb immediately devastated the entire city. People were in a state of shock, disbelief and denial; acute symptoms of post traumatic stress disorder (PTSD) were commonplace. Oklahomans, ‘numb’ from the impact of the critical incident and ill-equipped to handle the chaos of such catastrophic proportions, struggled to regain control of their lives as friends, family and loved ones went unaccounted for or were found critically injured, dying or already dead. The critical incident on 19 April demanded the immediate attention of the nation, to come to the aid of the Oklahomans who were in desparate need. By I June, the exhaustive investigations revealed that 30 office buildings in downtown Oklahoma City had to be condemned, and as many as 300 others were damaged. In addition, 168 people had been found dead including 19 children and one nurse working as an emergency services rescue worker. Approximately 490 other victims had been reported injured from the blast. Countless others have been traumatised by the critical event and will need professional attention and care for weeks, months and years to come. The final extent of the impact on Oklahoma City is yet unknown and may never realistically be estimated in terms of personal trauma, loss and grief.

EARTHQUAKE DAMAGE IN MUSEUM OBJECTS

The Museo Chileno de Arte Precolombino in Santiago, Chile, is located in the historic center of the city. The building, which served originally as the Courthouse, has a central patio surrounded by porticoes at both street and first floor level. The latter were closed by the installation of windows to form the actual exhibition galleries. The earthquake that shook Santiago de Chile at 7.46 p.m. on 3 March 1985 reached an intensity of eight degrees on the Merkalli scale. The vibrations caused the shauering of all the glass panes in the windows enclosing the galleries as well as damaging the air-conditioning system. As a consequence, all objects located in these galleries had to be accommodated in a spare room while the exhibition areas were reconditioned with new glass for the windows and a new air-conditioning system. In proportion to the intensity of the earthquake, relatively few pieces, only 34, were damaged in the galleries. This small number of casualties can be attributed to the fact that the galleries had, and still have, many rather small showcases with Plexiglas covers that fit into a groove cut around the baseboard. Neither the Plexiglas covers nor the cases moved or slid during the earthquake: the covers, because they fitted tightly into the case grooves; the cases because of their weight. In these small showcases, the objects that toppled during the quake remained caught between the base and the enclosing Plexiglas cover, thus preventing their final fall. The main damage to the collection can be attributed to the type of mounts used in the installation of the pieces for exhibit. Metallic blocks served as bases for the objects, and in many instances several cubes were piled to obtain different exhibition levels. During the quake, the various blocks in a given pile tended to slide in different directions, enhancing the vibration received by the object on top of them. The most spectacular damage occurred to a large ceramic statue, representing the XipeTotec deity of the Tolteca culture. The piece, dating from 1100 A.D., measures I09cm in height. The statue had been placed standing on a platform at the end of the '''gallery, and was only held by clamps at the ankles. Furthermore, one of the ankles had been previously broken and restored. To keep the public from touching this piece, a metal guard was placed in front of it. When the earthquake shook the building, the restored part did not resist the vibration, causing the piece to shake loose from the clamps, fall forward on top of the guard and literally shatter. In the store room, only one ceramic piece that had been put too near the edge of a shelf fell off and broke. All other pieces were prevented from sliding off the shelves during the tremors by the rubber runners that line them. The nightmarish experience of this earthquake prompted the development of a new approach to the design of appropriate stands for objects. This approach consists in having a mount accomplish a two-fold function, providing an elegant presentation for the object in question and protecting it in case of a quake. The key points to be taken into account in the design of an installation can be summarized as follows: