scholarly journals Verification of Operational Analyses Using an Extremely High-Density Surface Station Network

2011 ◽  
Vol 26 (4) ◽  
pp. 572-578 ◽  
Author(s):  
Alexander Kann ◽  
Thomas Haiden ◽  
Klaus von der Emde ◽  
Christine Gruber ◽  
Thomas Kabas ◽  
...  
Keyword(s):  
Complex Terrain ◽  
Average Distance ◽  
Sensitivity Study ◽  
High Density ◽  
Observation Data ◽  
Station Network ◽  
Small Domain ◽  
Surface Station ◽  
Density Surface

Abstract Operational analyses of 2-m temperature, 2-m humidity, and 10-m wind speed are verified independently against observations obtained from the WegenerNet, an extremely high-density, grid-type surface station network in southeastern Austria with an average distance between stations of 1.4 km. The Integrated Nowcasting through Comprehensive Analysis (INCA) system provides high-resolution analyses in space (1 km) and time (1 h) over the eastern Alpine region and has been specially designed for use in complex terrain. The quality of the system is investigated within a small domain with gentle topography ranging in elevation from 250 to 500 m. A comprehensive validation of INCA relative to WegenerNet for a 3-yr period from December 2007 to November 2010 indicates high analysis skill during all seasons. A sensitivity study reveals the importance of a sufficiently dense station network used by the system and, even more important, the relevance of adequate representativeness of the observation data.

scholarly journals Assessment of sparse GNSS network for network RTK

2018 ◽  
Vol 8 (1) ◽  
pp. 136-144 ◽  
Author(s):  
Hannu Koivula ◽  
Jaakko Kuokkanen ◽  
Simo Marila ◽  
Sonja Lahtinen ◽  
Tuukka Mattila
Keyword(s):  
Average Distance ◽  
Test Area ◽  
Reference Station ◽  
Station Network ◽  
Network Rtk ◽  
Land Survey ◽  
Network Area ◽  
Gnss Network

Abstract We tested the accuracy and usability of a sparse GNSS reference station network for network RTK (NRTK) using the Finnish permanent GNSS network FinnRef. We modified the configuration of the FinnRef network stations used in NRTK computation. This allowed us to perform the test both inside and outside of the network area using different NRTK methods and two different RTK receivers. In the test area the average distance between the FinnRef stationswas 160 km. As a comparison,we tested also with the commercial Trimnet and HxGN SmartNet positioning services operated by Geotrim Oy and Leica Geosystems Finland, respectively. Tests showed that the horizontal and vertical rms of Trimnet servicewas 16mmand 40 mm, and of HxGN SmartNet service 23mmand 48 mm. The best rms for the sparse NLS (National Land Survey of Finland) Service was 22 mm and 56 mm. These results indicate that a good NRTK solution can be achieved with a sparser network than typically used. This study also indicates, that the methods for NRTK processing can also affect the quality of the solution.

scholarly journals A database of high-density surface electromyogram signals comprising 65 isometric hand gestures

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Nebojša Malešević ◽  
Alexander Olsson ◽  
Paulina Sager ◽  
Elin Andersson ◽  
Christian Cipriani ◽  
...  
Keyword(s):  
Control Structure ◽  
High Density ◽  
Hand Movements ◽  
Hand Gestures ◽  
Prosthetic Hands ◽  
Hand Functions ◽  
Joint Forces ◽  
Density Surface ◽  
Electromyographic Signals

AbstractControl of contemporary, multi-joint prosthetic hands is commonly realized by using electromyographic signals from the muscles remaining after amputation at the forearm level. Although this principle is trying to imitate the natural control structure where muscles control the joints of the hand, in practice, myoelectric control provides only basic hand functions to an amputee using a dexterous prosthesis. This study aims to provide an annotated database of high-density surface electromyographic signals to aid the efforts of designing robust and versatile electromyographic control interfaces for prosthetic hands. The electromyographic signals were recorded using 128 channels within two electrode grids positioned on the forearms of 20 able-bodied volunteers. The participants performed 65 different hand gestures in an isometric manner. The hand movements were strictly timed using an automated recording protocol which also synchronously recorded the electromyographic signals and hand joint forces. To assess the quality of the recorded signals several quantitative assessments were performed, such as frequency content analysis, channel crosstalk, and the detection of poor skin-electrode contacts.

The basis of quality of sheep pelts and fur products is morphological features of the skin of sheep

2020 ◽  
pp. 50-57
Author(s):  
I. Dmitrik ◽  
G. Zavgorodnyaya
Keyword(s):  
Mechanical Strength ◽  
Breaking Load ◽  
Hair Follicles ◽  
Morphological Features ◽  
High Density ◽  
Fat Cells ◽  
High Quality ◽  
Histological Features ◽  
Weakened Zone

The morphological and histological features of the skin and wool cover of sheep as the basis for the quality of fur sheep pelts have been studied. The most important properties of sheep pelts (uniformity, thinness and density of wool) are provide the possibility of producing high-quality fur semi-finished products from them. However, the features of the histostructure of fine-wool sheep determine the low mechanical strength of the “facial” layer of skin. As a result, the “front” layer during processing often cracks to the upper border of the reticular layer or even peels off from the latter, making the sheep pelt unsuitable for use on fur products. These defects in fur practice are called “cracking” and “peeling” of the facial layer. They are mainly peculiar to sheep pelts of fine-wooled sheep. In these animals due to the high density and tone of the coat, the roots and hair follicles, root vaginas, secretory departments, excretory ducts of the glands and other structures occupy a significant share of the volume in the thickness of the Pilar layer (up to 25–30 %). The share of fibrous structures remains less volume, and these structures themselves are relatively weakly developed, located loosely and loosely intertwined with each other. The accumulations of fat cells that occur here also cannot be attributed to skin-strengthening elements. In fine-fleece sheep the pilar layer is on average 60 % of the thickness of the dermis. Therefore, more than half of its thickness is a weakened zone. The strength of the “front” layer is not the same in different fine-wool breeds of sheep and in different animals within the breed. For example, the average breaking load for cod of the “front” layer in Soviet Merino pelts is 1,25 kg, and in Precoce is 2,49 kg.

Bipolar versus high-density surface electromyography for evaluating risk in fatiguing frequency-dependent lifting activities

2021 ◽  
Vol 95 ◽  
pp. 103456
Author(s):  
Tiwana Varrecchia ◽  
Alberto Ranavolo ◽  
Silvia Conforto ◽  
Alessandro Marco De Nunzio ◽  
Michail Arvanitidis ◽  
...  
Keyword(s):  
Surface Electromyography ◽  
High Density ◽  
Frequency Dependent ◽  
Density Surface

scholarly journals Influence of the groundwater level on the bearing capacity of shallow foundations on the rock mass

2021 ◽  
Author(s):  
Ana Alencar ◽  
Rubén Galindo ◽  
Svetlana Melentijevic
Keyword(s):  
Rock Mass ◽  
Bearing Capacity ◽  
Groundwater Level ◽  
Sensitivity Study ◽  
Shallow Foundations ◽  
Unit Weight ◽  
Geological Strength Index ◽  
Strength Index ◽  
Mass Type

AbstractThe presence of the groundwater level (GWL) at the rock mass may significantly affect the mechanical behavior, and consequently the bearing capacity. The water particularly modifies two aspects that influence the bearing capacity: the submerged unit weight and the overall geotechnical quality of the rock mass, because water circulation tends to clean and open the joints. This paper is a study of the influence groundwater level has on the ultimate bearing capacity of shallow foundations on the rock mass. The calculations were developed using the finite difference method. The numerical results included three possible locations of groundwater level: at the foundation level, at a depth equal to a quarter of the footing width from the foundation level, and inexistent location. The analysis was based on a sensitivity study with four parameters: foundation width, rock mass type (mi), uniaxial compressive strength, and geological strength index. Included in the analysis was the influence of the self-weight of the material on the bearing capacity and the critical depth where the GWL no longer affected the bearing capacity. Finally, a simple approximation of the solution estimated in this study is suggested for practical purposes.

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