scholarly journals MEASURING OF SQUAT IN THE FAIRWAY TO THE PORT OF LULEA, NORTH SWEDEN

1968 ◽  
Vol 1 (11) ◽  
pp. 97
Author(s):  
Carl G. Carlstrom
Keyword(s):  
Standard Deviation ◽  
Turbulent Flow ◽  
Water Level ◽  
Measuring Method ◽  
Field Work ◽  
Accuracy Of Measurements ◽  
Solid Foundation ◽  
Sheltered Water ◽  
North Sweden

The importance of knowledge of squat and expected underkeel clearance for ships passing a fairway is essential to the navigational safety and the economy of a harbour. In order to check the squat of ships in the fairway to the port of Lulea a photographic measuring method has been evolved and used in measurements on three different ships. Determining of squat is made by levelling the position of vessels in relation to water level at the berth before sailing and en route at measuring points along the fairway. The accuracy of measurements was determined by observations on reference staffs. The order of standard deviation is 1/2 inch, at 2,400 feet distance. Observations indicate squat ranging from 1 foot 5 inches at speeds of 9 knots to 2 inches at 3>7 knots. The measured squat corresponds rather good to tneoretically calculated values according to Woltiger and Shell/Sogreah. The measuring method used has reduced the field work. The greatest advantage is that adequate values of squat will be directly recorded with only a few corrections including irregular factors such as turbulent flow, hull deformations and variable channel sections. A condition is however sheltered water and possioilities of solid foundation for instrument arrangement. 1499

Sphericity Measurement Using Stitching Interferometry

2012 ◽  
Vol 523-524 ◽  
pp. 883-888 ◽  
Author(s):  
Takeshi Hagino ◽  
Yuichiro Yokoyama ◽  
Yutaka Kuriyama ◽  
Han Haitjema
Keyword(s):  
Standard Deviation ◽  
High Precision ◽  
Measurement System ◽  
Three Dimensional ◽  
Measuring Method ◽  
Surface Areas ◽  
Reference Sphere ◽  
Five Axes ◽  
Roundness Measurement ◽  
Good Agreement

A newly developed practical sphericity measurement system by means of stitching interferometry is described in this paper. Spheres are widely used in industry. In particular, spheres with stem are usually used in metrological applications such as reference sphere for Coordinate Measuring Machines. It is common to calibrate form of spheres with tactile roundness measurement, however a comprehensive form measurement is desired for evolving high precision applications. The developed system consists of commercial base Fizeau type interferometer to capture partial surface areas of sphere and five axes stages to handle sphere with stem. Hence the system is very suitable for measurement of such stemmed spheres. This system yields three dimensional form maps of stitched sphere and peak to valley sphericity. Standard deviation of sphericity value yielded using this system is less than 5 nm in 8 times repetition. Finally, an equatorial profile clipped from stitched sphere shows good agreement with a result of tactile roundness measuring method within 10 nm typically.

scholarly journals WATER LEVEL MONITORING ON TIBETAN LAKES BASED ON ICESAT AND ENVISAT DATA SERIES

2017 ◽  
Vol XLII-2/W7 ◽  
pp. 1529-1533 ◽  
Author(s):  
H. W. Li ◽  
G. Qiao ◽  
Y. J. Wu ◽  
Y. J. Cao ◽  
H. Mi
Keyword(s):  
Standard Deviation ◽  
Water Level ◽  
Lake Water ◽  
Water Footprint ◽  
Scientific Data ◽  
Quality Data ◽  
Tibet Plateau ◽  
Data Series ◽  
Data Set ◽  
Wide Range

Satellite altimetry technique is an effective method to monitor the water level of lakes in a wide range, especially in sparsely populated areas, such as the Tibet Plateau (TP). To provide high quality data for time-series change detection of lake water level, an automatic and efficient algorithm for lake water footprint (LWF) detection in a wide range is used. Based on ICESat GLA14 Release634 data and ENVISat GDR 1Hz data, water level of 167 lakes were obtained from ICESat data series, and water level of 120 lakes were obtained from ENVISat data series. Among them, 67 lakes contained two data series. Mean standard deviation of all lakes is 0.088 meters (ICESat), 0.339 meters (ENVISat). Combination of multi-source altimetry data is helpful for us to get longer and more dense periods cover water level, study the lake level changes, manage water resources and understand the impacts of climate change better. In addition, the standard deviation of LWF elevation used to calculate the water level were analyzed by month. Based on lake data set for the TP from the 1960s, 2005, and 2014 in Scientific Data, it is found that the water level changes in the TP have a strong spatial correlation with the area changes.

scholarly journals LoRa Network Based Integrated Sluice Gates Group Automation Control System

2021 ◽  
Author(s):  
Yuhong Li ◽  
Jiajun Lu ◽  
Qiuhong Huang ◽  
Ji Xiong ◽  
Dan Li ◽  
...  
Keyword(s):  
Control System ◽  
Automatic Control ◽  
Water Level ◽  
Power Supply ◽  
Field Work ◽  
Level Gauge ◽  
Monitoring Centre ◽  
Different Types ◽  
Gate Control ◽  
Automation Control

A kind of gate automation group control system is designed based on LoRa networking, which is composed of intelligent gate control subsystems installed on all levels of channels, LoRa network and a cluster control system running in the monitoring centre. The system uses the water level and flow rate method, Doppler ultrasonic flowmeter, and laser water level gauge to realize the automatic metering function of the gate; the ultra-low power gate cluster control system based on LoRa network realizes the intelligent control and wireless remote communication of the gate terminal; Provides three different types of gate automatic control modes to meet the water supply needs of different types of irrigation areas; through the design of dual-circuit redundant power supply system design for solar power supply and mains power supply, the power supply problem of the gate field work is solved; remote dynamic water transfer control application software package realize the remote control, automatic control and system linkage of the gate.

scholarly journals The use of B-splines to represent the topography of river networks

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eva Boergens ◽  
Michael Schmidt ◽  
Florian Seitz
Keyword(s):  
Standard Deviation ◽  
Water Level ◽  
River Networks ◽  
Distributed Data ◽  
Outlier Removal ◽  
Directed Tree ◽  
B Splines ◽  
Tree Graphs ◽  
Main Challenge ◽  
Mean Square Errors

AbstractThis work presents a new extension to B-Splines that enables them to model functions on directed tree graphs such as non-braided river networks. The main challenge of the application of B-splines to graphs is their definition in the neighbourhood of nodes with more than two incident edges. Achieving that the B-splines are continuous at these points is non-trivial. For both, simplification reasons and in view of our application, we limit the graphs to directed tree graphs. To fulfil the requirement of continuity, the knots defining the B-Splines need to be located symmetrically along the edges with the same direction. With such defined B-Splines, we approximate the topography of the Mekong River system from scattered height data along the river. To this end, we first test and validate successfully the method with synthetic water level data, with and without added annual signal. The quality of the resulting heights is assessed besides others by means of root mean square errors (RMSE) and mean absolute differences (MAD). The RMSE values are 0.26 m and 1.05 m without and with added annual variation respectively and the MAD values are even lower with 0.11 m and 0.60 m. For the second test, we use real water level observations measured by satellite altimetry. Again, we successfully estimate the river topography, but also discuss the short comings and problems with unevenly distributed data. The unevenly distributed data leads to some very large outliers close to the upstream ends of the rivers tributaries and in regions with rapidly changing topography such as the Mekong Falls. Without the outlier removal the standard deviation of the resulting heights can be as large as 50 m with a mean value of 15.73 m. After the outlier removal the mean standard deviation drops to 8.34 m.

scholarly journals Assessment of Dukan Landslides, West of Sulaimani City, the Kurdistan Region, Northeast Iraq

2018 ◽  
Vol 2 (1) ◽  
pp. 28-38
Author(s):  
Varoujan K. Siakian ◽  
Sarhang A. Omer ◽  
Diyar Salah M.Khalil
Keyword(s):  
Water Level ◽  
Road Construction ◽  
Field Work ◽  
Geological Hazard ◽  
Kurdistan Region ◽  
Landslide Area ◽  
The Road ◽  
Paved Road ◽  
High Possibility ◽  
Marly Limestone

Four landslides of different sizes had occurred in 2012 along the main paved road between Dukan – Surdash. The landslides are within the Kometan Formation, which consist mainly of well bedded and jointed marly limestone. The landslides are located in a narrow syncline trending NW – SE in between Khalikan and Kalo anticlines. The main reason of the landslides is the haphazard road cuts during the road construction and widening of the road latter on. Another reason that had accelerated the landslide is the fluctuation of water level in Dukan reservoir. The water level reaches the down slope area of the landslides. Satellite imagery was used to study the parameters of the landslides and have performed a field work to confirm the acquired parameters and deduced other indications of the landslides, besides checking their stability. Landslide Possibility Study was performed using Landslide Possibility Index at each landslide area and have found that the whole area is unstable showing High possibility of re-failure. Sereographic presentation for the three landslides was used to show the relation between bedding and joint planes as well the road cuts trends.  It was concluded that in next rainy season, the whole area may form a severe geological hazard if necessary precautions are not considered. Therefore, urgent precautions were recommended to keep the slopes alongside the road cur as stable as possible. 

scholarly journals Seasonal variations of water quality at Doreri Gulf, Manokwari, West Papua

2021 ◽  
Vol 890 (1) ◽  
pp. 012007
Author(s):  
L Sembel ◽  
D Setijawati ◽  
D Yona ◽  
Y Risjani
Keyword(s):  
Water Quality ◽  
Standard Deviation ◽  
Seasonal Variations ◽  
Coastal Waters ◽  
Rainy Season ◽  
Field Work ◽  
Dry Season ◽  
Low Concentrations ◽  
Seasonal Factors ◽  
West Papua

Abstract The character of Manokwari City’s coastal waters is strongly influenced by activity on the mainland. The degradation in Sawaibu Gulf’s water quality has an impact on water quality nearby, as well as the waters of the Field Work Center (BLK), Lemon Island, and Tanjung Manggewa, which is part of Doreri Gulf. The purpose of this study was to determine the water quality in Doreri Gulf according on location and season. In February-April (rainy season) and August-October (dry season) 2020, the research was carried out within Doreri Gulf, Manokwari, West Papua. Turbidity, salinity, pH, temperature, and dissolved oxygen are amongst the variables analyzed. Its statistical analyses were performed descriptively using standard deviation and ANCOVA to correlate seasons and locations. Temperature, DO, and pH were highest at location 2; salinity showed highest at location 3; and turbidity were highest at location 1. Low concentrations of DO, pH, and salinity were measured at location 1; temperature showed highest at location 3; and turbidity were highest at location 1. The dry season would have the highest temperature, DO, pH, and salinity concentrations, meanwhile the rainy season had enough highest turbidity. The study confirms that there are no variations in water quality between location of each variable and that seasonal factors comprise the majority of differences in water quality.

Predictive Simulation of Concurrent Debris Flow: How Slope Failure Locations Affect Predicted Damage

2020 ◽  
Author(s):  
Kazuki Yamanoi ◽  
Satoru Oishi ◽  
Kenji Kawaike ◽  
Hajime Nakagawa
Keyword(s):  
Standard Deviation ◽  
Debris Flow ◽  
Water Level ◽  
Slope Failure ◽  
Predictive Simulation ◽  
Relative Standard ◽  
Case Simulation ◽  
Failure Location ◽  
Downstream Area ◽  
Debris Flow Initiation

Predictive simulation of concurrent debris flow using only pre-disaster information has proven to be difficult as a result of problems in predicting the location of debris-flow initiation (i.e., slope failure). However, because catchment topography has concave characteristics, with all channels in a catchment joining each other as they flow downstream, it is possible to predict damage to downstream area using relatively inaccurate initiation points. Based on this, this paper presents methodologies employing debris-flow initiation points generated randomly using statistical slope failure prediction. A many-case simulation across numerous initiation points was performed to quantify the effect of slope-failure location in terms of deviations in the predicted water level and terrain deformation. It was found that the relative standard deviation diminished as the points approached the downstream area, indicating a location-based predictability effect.

scholarly journals IMPROVING THE METHODOLOGY FOR METROLOGICAL CERTIFICATION OF TOTAL STATIONS AND LIGHT RANGE FINDERS

2021 ◽  
Vol 26 (4) ◽  
pp. 146-159
Author(s):  
Georgij A. Ustavich ◽  
◽  
Nikolay S. Kosarev ◽  
Dmitriy A. Barannikov ◽  
Ivan A. Mezentsev ◽  
...  
Keyword(s):  
Field Work ◽  
Metrological Certification ◽  
Distance Measurements ◽  
Length Unit ◽  
Technical Data ◽  
Uniformity Of Measurements ◽  
Accuracy Of Measurements ◽  
Direct Distance ◽  
The Difference ◽  
Almost All

To ensure the uniformity of measurements, it is necessary to perform periodic verifications of ge-odetic instruments in accordance with the requirements of the relevant regulatory documents. In relation to total stations and light meters, ensuring the uniformity of measurements should be carried out by conducting annual periodic checks with the use of stationary reference bases of the 2nd or 3rd category, which were previously created in almost all regions of the country. However, to date, only two such bases have been preserved on the territory of the Russian Federation. The reason for this situa-tion was the lack of proper metrological support for the line lengths of the reference bases themselves, caused by the need for organizational measures, the lack of trained specialists, as well as significant financial expenses for field work. In this regard, there was a scientific and technical task of developing a local calibration scheme (LCS) to provide periodic verifications of total stations and light-emitting diodes over the entire range of measured distances, which does not require the creation of stationary reference bases. For this purpose, the LCS scheme is proposed, based on the use of the method of direct distance measurements. Its essence lies in the simultaneous measurement of the selected distances by reference and verified total stations. To do this, a reference total station and a verifiable one are installed on two tripods located next to each other, which measure the same distance. After that, the total stations are swapped and the measurements are repeated. At the end of the measurement, the measured distances are compared with the reference and verified total stations. Then, based on the difference between these distances, a conclusion is made about the accuracy of the de-vice being tested, as stated in the technical data sheet. The results of the implementation of the proposed LCS showed that its scheme provides the accuracy of measurements at the level of the 2nd category reference basis, and the methodology and accuracy of the length unit transmission meets the of regulatory requirements.

scholarly journals The difference in the measurement of freeway space in an upright sitting position with and without electromyograph

2015 ◽  
Vol 27 (1) ◽  
Author(s):  
Stevani Monika Halim ◽  
Taufik Sumarsongko ◽  
Aprilia Adenan
Keyword(s):  
Standard Deviation ◽  
Comparative Study ◽  
Sampling Methods ◽  
Vertical Dimension ◽  
Sitting Position ◽  
Test Statistics ◽  
Accuracy Of Measurements ◽  
The Mean ◽  
The Difference ◽  
Seating Position

Introduction: Measurement of vertical dimension is very important because improper measurement of vertical dimension may create stomatognatic problem. Electromyography is a tool for recording electrical signals generated from the mechanism of muscle contraction.This study aims to determine the accuracy of measurements of FWS with and without electromyograph.  Methods: This research was a descriptive comparative study using purposive sampling methods. Measurements of FWS in an upright sitting position with and without electromyograph were done on 10 students of class 2008 from Faculty of Dentistry, UNPAD who met the criteria. Data were analyzed by t test statistics, showed that there were significant differences in the measurements with and without electromyography in upright sitting position. Results: The mean of FWS measured with electromyography was 2.38 mm with standard deviation of 0.44 mm, whereas the mean of FWS measured without electromyography was 1.69 mm with a standard deviation of 0.46 mm. Average FWS in men measured with electromyography was 2.51 mm with a standard deviation of 0.15 mm, whereas the mean without electromyography was 1.68 mm with a standard deviation of 0.43 mm. Average FWS in women measured with electromyography was 2.35 mm with a standard deviation of 0.49 mm, whereas the mean without electromyography was 1.69 mm with a standard deviation of 0.50 mm. Conclusion: The measurements of FWS with electromyograph in an upright seating position was greater than without electromyography.

The prototype for measuring the height and monitoring of river water quality based on the Internet of Things

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Sofyan Radit Kurniawan ◽  
Syamsudduha Syahrorini
Keyword(s):  
Standard Deviation ◽  
Internet Of Things ◽  
Water Level ◽  
River Water ◽  
The Internet ◽  
Measurement Tool ◽  
Ultrasound Sensor ◽  
Android Applications ◽  
The Stability ◽  
The Internet Of Things

Abstract. Technology continues to develop from year to year which aims to simplify human work or automation of a system. The concept of measuring the water level is automatically applied to the river in front of the Tanggulangin tourism market, which aims to make it easier for residents to check the river water level in real time via the internet network. By utilizing the DS18B20 sensor to find out the temperature which has 97.85% accuracy and the HC-SR04 ultrasonic distance sensor which has 100% accuracy at a distance of less than 20 CM to find out the water level based on changes in the distance value on the sensor as an indication of the rise and fall of river water. From the sensor, the sensor is controlled with the Arduino UNO and NodeMCU microcontroller board to make the system work automatically, as well as the use of the MIT App Inventor to create android applications and to support the internet of things system. From the results of this research, it is obtained: (1). In the HC-SR04 ultrasound sensor test, the stability of the measurement value is very good, seen from the standard deviation value. (2). In testing the DS18B20 temperature sensor with a standard thermometer ratio has a difference of 0.7 ° C accuracy with an accuracy of 97.85% so that it can be used as a measurement tool. (3). On the TDS sensor, the standard deviation can be between 130-141 ppm which indicates this tool can function properly. (4). On the LCD, it can work properly and is ready to use in a system that functions to display information carried out by the microcontroller. (5). For pH sensors, this sensor can measure the degree of acidity / basicity of water between 1-10 pH.

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