Fiber optic time break

Geophysics ◽  
1996 ◽  
Vol 61 (1) ◽  
pp. 294-298 ◽  
Author(s):  
Anton W. Kepic ◽  
R. D. Russell
Keyword(s):  
Time Lag ◽  
Geophysical Methods ◽  
Personal Communication ◽  
Electrical Current ◽  
Explosive Material ◽  
Actual Performance ◽  
The Cost ◽  
Explosive Devices ◽  
And Storage ◽  
Better Than

Geophysical methods that use explosive seismic sources need to produce an accurate time break signal at the time of the blast. This is generally achieved with a seismic detonator, a special variety of electrical detonator (or cap) that is designed to have minimal latency between the injection of electrical current into the detonator and initiation of the explosion, as well as having a slightly higher base charge and better water resistance. A time‐break signal is obtained by either electronically controlling or monitoring the blast current. Seismic detonators are guaranteed to have better than a millisecond latency if sufficient current is injected into the leads; the necessary current is usually 5 to 10 amps. A millisecond tolerance is acceptable for most seismic work but may not be sufficient for shallow studies or for crosswell tomography. However, in fairness to the seismic detonator, the actual performance is generally better: Burrows (1936) and, independently, Rolland and White (1937) reported a time lag of less than 0.3 ms with a deviation of 0.1 ms. These values have changed little since the 1940s. The MK 2 from C.I.L. Inc. (a division of I.C.I.) has an average lag of 0.3–0.4 ms (personal communication with I.C.I. explosives). Major improvements in electric detonator design have been in the areas of safety and durability. A much greater disadvantage for explosive sources are the strict regulations on the transport and storage of explosive devices (Tour, 1992). The cost of complying with these regulations may prohibit the use of explosives in small surveys or in remote areas. An example is the transport of explosives by aircraft: the only passengers allowed on board are those neccesary for completing the flight and for transporting the explosives. Chartering an aircraft to transport a small amount of explosive material is too costly for many geotechnical and mining geophysics surveys.

INTELLIGENT PAGING STRATEGIES FOR THIRD GENERATION PERSONAL COMMUNICATION SERVICES NETWORKS

2000 ◽  
Vol 01 (03) ◽  
pp. 153-171 ◽  
Author(s):  
PARTHA SARATHI BHATTACHARJEE ◽  
DEBASHIS SAHA ◽  
AMITAVA MUKHERJEE
Keyword(s):  
Personal Communication ◽  
Third Generation ◽  
Delay Constraint ◽  
Communication Services ◽  
Processing Power ◽  
Personal Communication Services ◽  
Traffic Rate ◽  
The Cost ◽  
Paging Cost ◽  
Better Than

We consider the problem of minimizing paging cost, subject to delay constraint, in Personal Communication Services Network (PSCN) and present two intelligent paging strategies for third generation systems. They are termed as sequential intelligent paging (SIP) and parallel-o-sequential intelligent paging (PSIP). Unlike the conventional blanket paging where all cells in a location area are polled at a time, in SIP (PSIP) one cell (a group of cells) is polled at a time. The proposed schemes lead to a decrease in paging signaling load at the cost of some extra processing power. When better discovery rate per cycle is expected irrespective of the incoming traffic PSIP is always preferred to other paging schemes primarily because of its less amount of polling delay. If the incoming traffic rate is low, SIP performs better than PSIP in terms of paging cost per cycle. However, the polling costs per cycle and the discovery rates for both the schemes become equal as number of paging requests per cycle increases. An improvement in respect of paging cost per cycle and discovery rate over conventional paging is shown with the help of simulation results.

Integration of Multi-geophysical Approaches to Identify Potential Pathways of Heavy Metals Contamination - A Case Study in Zeida, Morocco

2020 ◽  
Vol 25 (3) ◽  
pp. 415-423
Author(s):  
Ahmed Lachhab ◽  
El Mehdi Benyassine ◽  
Mohamed Rouai ◽  
Abdelilah Dekayir ◽  
Jean C. Parisot ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Seismic Velocity ◽  
Seismic Refraction ◽  
Geophysical Methods ◽  
Low Frequency ◽  
Electrical Current ◽  
P Wave ◽  
Low Resistivity ◽  
Refraction Tomography ◽  
Geophysical Surveys

The tailings of Zeida's abandoned mine are found near the city of Midelt, in the middle of the high Moulouya watershed between the Middle and the High Atlas of Morocco. The tailings occupy an area of about 100 ha and are stored either in large mining pit lakes with clay-marl substratum or directly on a heavily fractured granite bedrock. The high contents of lead and arsenic in these tailings have transformed them into sources of pollution that disperse by wind, runoff, and seepage to the aquifer through faults and fractures. In this work, the main goal is to identify the pathways of contaminated water with heavy metals and arsenic to the local aquifers, water ponds, and Moulouya River. For this reason, geophysical surveys including electrical resistivity tomography (ERT), seismic refraction tomography (SRT) and very low-frequency electromagnetic (VLF-EM) methods were carried out over the tailings, and directly on the substratum outside the tailings. The result obtained from combining these methods has shown that pollutants were funneled through fractures, faults, and subsurface paleochannels and contaminated the hydrological system connecting groundwater, ponds, and the river. The ERT profiles have successfully shown the location of fractures, some of which extend throughout the upper formation to depths reaching the granite. The ERT was not successful in identifying fractures directly beneath the tailings due to their low resistivity which inhibits electrical current from propagating deeper. The seismic refraction surveys have provided valuable details on the local geology, and clearly identified the thickness of the tailings and explicitly marked the boundary between the Triassic formation and the granite. It also aided in the identification of paleochannels. The tailings materials were easily identified by both their low resistivity and low P-wave velocity values. Also, both resistivity and seismic velocity values rapidly increased beneath the tailings due to the compaction of the material and lack of moisture and have proven to be effective in identifying the upper limit of the granite. Faults were found to lie along the bottom of paleochannels, which suggest that the locations of these channels were caused by these same faults. The VLF-EM surveys have shown tilt angle anomalies over fractured areas which were also evinced by low resistivity area in ERT profiles. Finally, this study showed that the three geophysical methods were complementary and in good agreement in revealing the pathways of contamination from the tailings to the local aquifer, nearby ponds and Moulouya River.

scholarly journals Telecom Churn Prediction System Based on Ensemble Learning Using Feature Grouping

2021 ◽  
Vol 11 (11) ◽  
pp. 4742
Author(s):  
Tianpei Xu ◽  
Ying Ma ◽  
Kangchul Kim
Keyword(s):  
Ensemble Learning ◽  
Machine Learning Algorithms ◽  
Customer Relationship ◽  
Prediction System ◽  
Churn Prediction ◽  
Customer Churn ◽  
Feature Grouping ◽  
Recognition Systems ◽  
The Cost ◽  
Better Than

In recent years, the telecom market has been very competitive. The cost of retaining existing telecom customers is lower than attracting new customers. It is necessary for a telecom company to understand customer churn through customer relationship management (CRM). Therefore, CRM analyzers are required to predict which customers will churn. This study proposes a customer-churn prediction system that uses an ensemble-learning technique consisting of stacking models and soft voting. Xgboost, Logistic regression, Decision tree, and Naïve Bayes machine-learning algorithms are selected to build a stacking model with two levels, and the three outputs of the second level are used for soft voting. Feature construction of the churn dataset includes equidistant grouping of customer behavior features to expand the space of features and discover latent information from the churn dataset. The original and new churn datasets are analyzed in the stacking ensemble model with four evaluation metrics. The experimental results show that the proposed customer churn predictions have accuracies of 96.12% and 98.09% for the original and new churn datasets, respectively. These results are better than state-of-the-art churn recognition systems.

scholarly journals Optimization of Network Carbon Capture and Storage System (CCS) Using Mathematical Approach

2015 ◽  
Vol 9 (7) ◽  
pp. 161
Author(s):  
David Licindo ◽  
Arinne Christin Paramudita ◽  
Renanto Handogo ◽  
Juwari Purwo Sutikno
Keyword(s):  
Carbon Capture ◽  
Storage System ◽  
Carbon Capture And Storage ◽  
Exact Result ◽  
Maximum Load ◽  
Mathematical Approach ◽  
Source To Sink ◽  
Storage Location ◽  
The Cost ◽  
And Storage

Carbon capture and storage (CCS) is one of the technologies to reduce greenhouse gas emissions (GHG) tocapture of CO2 from the flue gas of a power plant that typically use coal as a Source of energy and then store it ina suitable geological storage (in specific locations). In practice, these sites may not be readily available forstorage at the same time that the Sources (GHG producing) are operating which gives rise to multi – periodplanning problems. This study presents a mathematical approach by considering constraints limit flowratereceived by Sink, various time availability of Sink and Source and calculation with the purpose to determine theminimum cost network which is getting the maximum load that is exchanged from Source to Sink. Illustrativecase studies are given to demonstrate the application of mathematical models to obtained with the exact result ofthe exchange network from Source to Sink. Derived from network obtained from the calculation of theMaximum Load Source to Sink and results may vary in accordance with the limitations that exist in themathematical model. The case study has been prepared with 2 cases, first 6 Source and 3 Sink with value ofSource Load is greater than the amount available on the Sink. Also, second case is 2 Source and 5 Sinkwithvalue of Source Load is smaller than the amount available on the Sink. In addition, Case Studies tominimize the cost of pipeline construction and distribution of CO2 by plant and storage location determination inJava. Flowrate restriction factor that goes into Sink, Source and Sink establishment time and cost are taken intoaccount can affect the networks that can be exchanged from the Source to the Sink.

Sex and Birth Order in Children's Goal Setting and Actual Performance of a Gross Motor Task

1981 ◽  
Vol 53 (2) ◽  
pp. 663-666 ◽  
Author(s):  
Evelyn G. Hall ◽  
Amelia M. Lee
Keyword(s):  
Elementary School ◽  
Birth Order ◽  
Goal Setting ◽  
Motor Task ◽  
Complete Data ◽  
School Age ◽  
Gross Motor ◽  
Actual Performance ◽  
Elementary School Age ◽  
Better Than

This study investigated the effect of birth order and sex on goal setting and actual performance by boys and girls of elementary school age on a ring-toss task. Children were asked to give a verbal estimate of the number of successful trials out of 10 they expected to complete. Data were analyzed by 2 (sex) × 2 (birth order) analyses of variance. Results indicated that firstborn boys set higher goals and performed significantly better than later-born boys, firstborn girls or later-born girls.

The Race for Online Reputation: Implications for Platforms, Firms, and Consumers

2021 ◽  
Author(s):  
Mingwen Yang ◽  
Zhiqiang (Eric) Zheng ◽  
Vijay Mookerjee
Keyword(s):  
Adverse Event ◽  
Marketing Mix ◽  
Digital Economy ◽  
The Other ◽  
The Mean ◽  
The Absolute ◽  
The Cost ◽  
Online Reputation ◽  
Better Than

Online reputation has become a key marketing-mix variable in the digital economy. Our study helps managers decide on the effort they should use to manage online reputation. We consider an online reputation race in which it is important not just to manage the absolute reputation, but also the relative rating. That is, to stay ahead, a firm should try to have ratings that are better than those of its competitors. Our findings are particularly significant for platform owners (such as Expedia or Yelp) to strategically grow their base of participating firms: growing the middle of the market (firms with average ratings) is the best option considering the goals of the platform and the other stakeholders, namely incumbents and consumers. For firms, we find that they should increase their effort when the mean market rating increases. Another key insight for firms is that, sometimes, adversity can come disguised as an opportunity. When an adverse event strikes the industry (such as a reduction in sales margin or an increase in the cost of effort), a firm’s profit can increase if it can manage this event better than its competitors.

Electro-Fenton as a feasible advanced treatment process to produce reclaimed water

2004 ◽  
Vol 50 (2) ◽  
pp. 83-90 ◽  
Author(s):  
A. Durán Moreno ◽  
B.A. Frontana-Uribe ◽  
R.M. Ramírez Zamora
Keyword(s):  
Reclaimed Water ◽  
Electrical Current ◽  
Primary Treatment ◽  
Operating Conditions ◽  
Treatment System ◽  
Continuous Reactor ◽  
Fenton’S Reagent ◽  
Fenton's Reagent ◽  
Fenton’S Reaction ◽  
The Cost

The feasibility of the electro-Fenton process to generate simultaneously both of the Fenton's reagent species (Fe2+/H2O2), was assessed as a potentially more economical alternative to the classical Fenton's reaction to produce reclaimed water. An air-saturated combined wastewater (mixture of municipal and laboratory effluents) was treated in discontinuous and continuous reactors at pH = 3.5. The discontinuous reactor was a 2 L electrochemical laboratory cell fitted with concentric graphite and iron electrodes. The continuous reactor tests used a pilot treatment system comprising the aforementioned electrochemical cell, two clarifiers and one sand filter. Several tests were carried out at different conditions of reaction time (0-60 min) and electrical current values (0.2-1.0 A) in the discontinuous reactor. The best operating conditions were 60 min and 1 A without filtration of effluents. At these conditions, in discontinuous and continuous reactors with filtration, the COD, turbidity and color removal were 65-74.8%, 77-92.3% and 80-100%, respectively. Fecal and total coliforms, Escherichia coli, Shigella and Salmonella sp. were not detected at the end of the pilot treatment system. Electrogeneration of the Fenton's reagent is also economical; its cost is one-fifth the cost reported for Advanced Primary Treatment.

scholarly journals Managing cost uncertainties in transportation and assignment problems

1998 ◽  
Vol 2 (1) ◽  
pp. 65-104 ◽  
Author(s):  
V. Adlakha ◽  
H. Arsham
Keyword(s):  
Time Lag ◽  
Real Life ◽  
Optimal Solution ◽  
Global Market ◽  
Solution Algorithm ◽  
Assignment Problems ◽  
The Stability ◽  
Order Assignment ◽  
Cost Parameters ◽  
The Cost

In a fast changing global market, a manager is concerned with cost uncertainties of the cost matrix in transportation problems (TP) and assignment problems (AP).A time lag between the development and application of the model could cause cost parameters to assume different values when an optimal assignment is implemented. The manager might wish to determine the responsiveness of the current optimal solution to such uncertainties. A desirable tool is to construct a perturbation set (PS) of cost coeffcients which ensures the stability of an optimal solution under such uncertainties.The widely-used methods of solving the TP and AP are the stepping-stone (SS) method and the Hungarian method, respectively. Both methods fail to provide direct information to construct the needed PS. An added difficulty is that these problems might be highly pivotal degenerate. Therefore, the sensitivity results obtained via the available linear programming (LP) software might be misleading.We propose a unified pivotal solution algorithm for both TP and AP. The algorithm is free of pivotal degeneracy, which may cause cycling, and does not require any extra variables such as slack, surplus, or artificial variables used in dual and primal simplex. The algorithm permits higher-order assignment problems and side-constraints. Computational results comparing the proposed algorithm to the closely-related pivotal solution algorithm, the simplex, via the widely-used pack-age Lindo, are provided. The proposed algorithm has the advantage of being computationally practical, being easy to understand, and providing useful information for managers. The results empower the manager to assess and monitor various types of cost uncertainties encountered in real-life situations. Some illustrative numerical examples are also presented.

scholarly journals Isothermal Crystallization and Rheology Properties of Isotactic Polypropylene/Bacterial Cellulose Composite

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1284 ◽  
Author(s):  
Bo Wang ◽  
Fu-hua Lin ◽  
Xiang-yang Li ◽  
Zhong-wei Zhang ◽  
Xiao-rong Xue ◽  
...  
Keyword(s):  
Bacterial Cellulose ◽  
Storage Modulus ◽  
Isotactic Polypropylene ◽  
Crystallization Temperature ◽  
Isothermal Crystallization ◽  
Complex Viscosity ◽  
Isothermal Crystallization Kinetics ◽  
Interfacial Compatibility ◽  
And Storage ◽  
Better Than

Bacterial cellulose (BC) is a new kind of cellulose with great potential in enhancing preparation of isotactic Polypropylene (iPP) composites, which have been found with excellent performance. However, the interface compatibility between BC and iPP is poor. In this study, iPP/BC composites were prepared by solution mixing. Esterification modified BC (CO) and Maleic anhydride grafted polypropylene (MAPP) added as a compatibilizer was both used to improve the interfacial compatibility of the iPP/BC composites. The rheology and isothermal crystallization behavior of the composites was tested and discussed. The result shows that the complex viscosity and storage modulus of the composite significantly increase in the rule iPP, iPP/BC2, iPP/CO2, and M-iPP/BC3, which indicates that the compatibility of the composite increases as this rule. According to the isothermal crystallization kinetics result, the crystal growth mode of iPP was not affected by the addition of BC and the interfacial compatibility. The spherulite growth rate of the iPP/BC composite increases with increasing crystallization temperature. Especially, the value decreases as the same rule with the complex viscosity and storage modulus of the composite at the same isothermal crystallization temperature. These results suggest that the interface compatibility of iPP/BC composites is greatly improved and the interface compatibility of the M-iPP/BC3 is better than the iPP/CO2.

scholarly journals A motor imagery during blind action is guided by the same foci of attention as actual performance in a sample comprising females

2014 ◽  
Vol 7 (2) ◽  
pp. 11-16
Author(s):  
Bassem Khalaf
Keyword(s):  
Mental Imagery ◽  
Focus Of Attention ◽  
Direct Role ◽  
Actual Performance ◽  
External Focus ◽  
Deviation Measure ◽  
Straight Line ◽  
Internal Focus ◽  
Perceptual Representations ◽  
Better Than

There is strong evidence that focussing on the goal of an action improves performance relative to focussing on the concrete motor behaviours. The current study tests whether blind action guided by imagery relies on the same foci of attention. Thirty female participants took part in an experiment. In each condition there were 20 trials, they were asked to close their eyes and draw a straight line between two landmarks on a graphics tablet. We instructed them, in three conditions, to focus on (1) mental imagery of the goal landmark (external focus of attention), (2) drawing a straight line with the fingers (internal focus), or (3) without a specific focus of attention (control). We tested to what extent these attention instructions affected drawing performance, in terms of both deviations of the participants’ lines from an ideal straight line, and the time it took to complete the line. The study revealed that the manipulation specifically affected the deviation measure and that an external focus of attention was better than an internal focus and the control condition. These findings reveal that that mental imagery during blind action relies on same processes as actual performance. These data give perceptual representations of a direct role in motor control. They will be related to current theories of action control (constrained action hypothesis, ideomotor theories, and dual task accounts).

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