scholarly journals A Survey of Methods for Gas-Lift Optimization

2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Kashif Rashid ◽  
William Bailey ◽  
Benoît Couët
Keyword(s):  
Large Scale ◽  
Optimization Problem ◽  
Multivariate Optimization ◽  
Flow Lines ◽  
Single Well ◽  
Large Scale Networks ◽  
Optimization Schemes ◽  
Gas Lift ◽  
Insight Into

This paper presents a survey of methods and techniques developed for the solution of the continuous gas-lift optimization problem over the last two decades. These range from isolated single-well analysis all the way to real-time multivariate optimization schemes encompassing all wells in a field. While some methods are clearly limited due to their neglect of treating the effects of inter-dependent wells with common flow lines, other methods are limited due to the efficacy and quality of the solution obtained when dealing with large-scale networks comprising hundreds of difficult to produce wells. The aim of this paper is to provide an insight into the approaches developed and to highlight the challenges that remain.

scholarly journals Optimizing schedules for the VLBI global observing system

2020 ◽  
Vol 94 (1) ◽  
Author(s):  
Matthias Schartner ◽  
Johannes Böhm
Keyword(s):  
Large Scale ◽  
Optimization Problem ◽  
Very Long Baseline Interferometry ◽  
Proper Selection ◽  
Long Baseline ◽  
Weight Factors ◽  
Highly Correlated ◽  
Insight Into ◽  
Selection Of

AbstractVery long baseline interferometry (VLBI) scheduling is a challenging optimization problem. With the development of the new VLBI global observing system (VGOS) consisting of smaller but very fast slewing antennas, new opportunities arise. In this work, we give a deep insight into optimized VGOS scheduling using a newly developed VLBI scheduling software called VieSched, and we show how different scheduling parameters and approaches affect the precision of geodetic results. Therefore, the results of over one thousand generated schedules and over one million simulated sessions are analyzed. The simulations reveal that the most important parameters to optimize VGOS schedules with VieSched are the so-called weight factors. A proper selection of individually optimized weight factors can improve the quality of a schedule significantly. It is shown that the values of the weight factors used to generate the schedule are highly correlated with the expected precision of the geodetic parameters. We highlight the benefit of selecting schedules based on large-scale Monte Carlo simulations and show why scheduling statistics like the number of observations or the sky-coverage are not necessarily the best metric to evaluate schedules.

scholarly journals Design and Demonstration of Large Scale Cu2O Photocathodes with Metal Grid Structure for Photoelectrochemical Water Splitting

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7422
Author(s):  
Min-Kyu Son
Keyword(s):  
Water Splitting ◽  
Large Scale ◽  
Grid Structure ◽  
Large Area ◽  
Intrinsic Conductivity ◽  
Metal Grid ◽  
Splitting System ◽  
Insight Into ◽  
Better Than

Upscaling of photoelectrode for a practical photoelectrochemical (PEC) water splitting system is still challenging because the PEC performance of large-scale photoelectrode is significantly low, compared to the lab scale photoelectrode. In an effort to overcome this challenge, sputtered gold (Au) and copper (Cu) grid lines were introduced to improve the PEC performance of large-scale cuprous oxide (Cu2O) photocathode in this work. It was demonstrated that Cu grid lines are more effective than Au grid lines to improve the PEC performance of large-scale Cu2O photocathode because its intrinsic conductivity and quality of grid lines are better than ones containing Au grid lines. As a result, the PEC performance of a 25-cm2 scaled Cu2O photocathode with Cu grid lines was almost double than one without grid lines, resulting in an improved charge transport in the large area substrate by Cu grid lines. Finally, a 50-cm2 scaled Cu2O photocathode with Cu grid lines was tested in an outdoor condition under natural sun. This is the first outdoor PEC demonstration of large-scale Cu2O photocathode with Cu grid lines, which gives insight into the development of efficient upscaled PEC photoelectrode.

scholarly journals Analisis Perbandingan Quality Of Service (Qos) Pada Performa Bandwidth Jaringan Dengan Metode Hierarchical Token Bucket (Htb) Dan Per Connection Queque (Pcq).

Respati ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 24
Author(s):  
Adytia A. Tambunan ◽  
Lukman Lukman
Keyword(s):  
Quality Of Service ◽  
Large Scale ◽  
Improve Quality ◽  
Bandwidth Management ◽  
Available Bandwidth ◽  
Service Parameter ◽  
Token Bucket ◽  
Large Scale Networks ◽  
Network Administrators

INTISARIQuality of Service (QoS) adalah cara cerdas untuk mengalokasikan bandwidth yang tersedia. Penggunaan manajemen bandwidth sebagai parameter Quality of Service tidak hanya membatasi tetapi menjaga kualitas bandwidth, sehingga semua pengguna yang terhubung dalam satu jaringan mendapatkan kualitas internet yang merata dan stabil. Ada beberapa cara untuk mengaplikasikan bandwidth managemen untuk meningkatkan Quality of Service, salah satunya yakni menggunakan mikrotik.Ada banyak metode manajemen   bandwidth yang dapat digunakan atau diterapkan pada jaringan yang menggunakan router mikrotik. Adapun yang paling sering digunakan dalam jaringan berskala menengah atau pun besar seperti metode Hierarchical Token Bucket (HTB) dan Per Connection Queue (PCQ).Penelitian ini akan melakukan analisis variabel Quality of Service (QoS) terhadap performa bandwidth dengan membandingkan dua metode antrian yaitu metode Hierarchical Token Bucket (HTB) dan metode Per Connection Queue (PCQ).  Penelitian dilakukan untuk mengetahui metode manakah lebih baik untuk di implementasikan oleh administrator jaringan agar efesien dan tepat untuk digunakan.Kata kunci: Manajemen Bandwidth, QOS, PCQ, HTB, Mikrotik. ABSTRACTQuality of Service (QoS) is a smart way to allocate available bandwidth. The use of bandwidth management as a Quality of Service parameter not only limits but maintains bandwidth quality, so that all users connected in one network get an even and stable internet quality. There are several ways to apply bandwidth management to improve Quality of Service, one of which is using a proxy.There are many bandwidth management methods that can be used or applied to networks that use a proxy router. As for what is most often used in medium or large scale networks such as the Hierarchical Token Bucket (HTB) and Per Connection Queue (PCQ) methods.This study will analyze the Quality of Service (QoS) variable on bandwidth performance by comparing two queuing methods, namely the Hierarchical Token Bucket (HTB) method and the Per Connection Queue (PCQ) method. The study was conducted to determine which method is better for network administrators to implement in order to be efficient and appropriate to use.Keywords: Bandwidth Management, QOS, PCQ, HTB, Mikrotik.

scholarly journals Improving the Effectiveness and Efficiency of Stochastic Neighbour Embedding with Isolation Kernel

2021 ◽  
Vol 71 ◽  
pp. 667-695
Author(s):  
Ye Zhu ◽  
Kai Ming Ting
Keyword(s):  
Large Scale ◽  
Computational Cost ◽  
Gaussian Kernel ◽  
Space Partitioning ◽  
Root Cause ◽  
Use Of Data ◽  
Local Point ◽  
Effectiveness And Efficiency ◽  
Insight Into

This paper presents a new insight into improving the performance of Stochastic Neighbour Embedding (t-SNE) by using Isolation kernel instead of Gaussian kernel. Isolation kernel outperforms Gaussian kernel in two aspects. First, the use of Isolation kernel in t-SNE overcomes the drawback of misrepresenting some structures in the data, which often occurs when Gaussian kernel is applied in t-SNE. This is because Gaussian kernel determines each local bandwidth based on one local point only, while Isolation kernel is derived directly from the data based on space partitioning. Second, the use of Isolation kernel yields a more efficient similarity computation because data-dependent Isolation kernel has only one parameter that needs to be tuned. In contrast, the use of data-independent Gaussian kernel increases the computational cost by determining n bandwidths for a dataset of n points. As the root cause of these deficiencies in t-SNE is Gaussian kernel, we show that simply replacing Gaussian kernel with Isolation kernel in t-SNE significantly improves the quality of the final visualisation output (without creating misrepresented structures) and removes one key obstacle that prevents t-SNE from processing large datasets. Moreover, Isolation kernel enables t-SNE to deal with large-scale datasets in less runtime without trading off accuracy, unlike existing methods in speeding up t-SNE.

scholarly journals A Survey of Outlier Detection Techniques in IoT: Review and Classification

2022 ◽  
Vol 11 (1) ◽  
pp. 4
Author(s):  
Mustafa Al Samara ◽  
Ismail Bennis ◽  
Abdelhafid Abouaissa ◽  
Pascal Lorenz
Keyword(s):  
Outlier Detection ◽  
Large Scale ◽  
Base Station ◽  
Home Networks ◽  
Detection Techniques ◽  
Advantages And Disadvantages ◽  
Large Scale Networks ◽  
Data Efficiency ◽  
Different Sources

The Internet of Things (IoT) is a fact today where a high number of nodes are used for various applications. From small home networks to large-scale networks, the aim is the same: transmitting data from the sensors to the base station. However, these data are susceptible to different factors that may affect the collected data efficiency or the network functioning, and therefore the desired quality of service (QoS). In this context, one of the main issues requiring more research and adapted solutions is the outlier detection problem. The challenge is to detect outliers and classify them as either errors to be ignored, or important events requiring actions to prevent further service degradation. In this paper, we propose a comprehensive literature review of recent outlier detection techniques used in the IoTs context. First, we provide the fundamentals of outlier detection while discussing the different sources of an outlier, the existing approaches, how we can evaluate an outlier detection technique, and the challenges facing designing such techniques. Second, comparison and discussion of the most recent outlier detection techniques are presented and classified into seven main categories, which are: statistical-based, clustering-based, nearest neighbour-based, classification-based, artificial intelligent-based, spectral decomposition-based, and hybrid-based. For each category, available techniques are discussed, while highlighting the advantages and disadvantages of each of them. The related works for each of them are presented. Finally, a comparative study for these techniques is provided.

PageRank Algorithm-Based Recommender System Using Uniformly Average Rating Matrix

2019 ◽  
pp. 99-112
Author(s):  
Bathrinath S. ◽  
Saranyadevi S. ◽  
Thirumalai Kumaran S. ◽  
Saravanasankar S.
Keyword(s):  
Recommender Systems ◽  
Large Scale ◽  
User Behavior ◽  
Personalized Recommendation ◽  
Pagerank Algorithm ◽  
Large Scale Networks ◽  
Matrix Construction ◽  
Item Item ◽  
New Item

Applications of web data mining is the prediction of user behavior with respect to items. Recommender systems are being applied in knowledge discovery techniques to the problem of making decisions on personalized recommendation of information. Traditional CF approaches involve the amount of effort increases with number of users. Hence, new recommender systems need to be developed to process high quality recommendations for large-scale networks. In this chapter, a model for UAR matrix construction method for item rank calculations, a Page Rank-based item ranking approach are proposed. The analysis of various techniques for computing item-item similarities to identify relationship between the selected items and to produce a qualified recommendation for users to acquire the items as their wish. As a result, the new item rank-based approaches improve the quality of recommendation outcome. Results show that the proposed UAR method outperforms than the existing method. The same method is applied for the large real-time rating dataset like Movie Lens.

The Passion Plays in Tegelen: An investigation into the function of a passion play

1991 ◽  
Vol 16 (1) ◽  
pp. 29-39
Author(s):  
Robert L. Erenstein
Keyword(s):  
Large Scale ◽  
World View ◽  
External Interference ◽  
Passion Plays ◽  
Passion Play ◽  
Cultural Phenomenon ◽  
Theatrical Performance ◽  
And Performance ◽  
Insight Into

Passion plays in Europe exhibit a great many similarities as far as general content and presentation are concerned. I do not really think it is relevant for the non-Dutch reader, therefore, to delve too deeply into the specifics of content and presentation with regard to the passion plays in Tegelen in Limburg, the southernmost province of the Netherlands. However, a great deal of the external interference surrounding the passion plays in Tegelen, has also been experienced by the organisers of numerous passion plays in Europe. Therefore, rather than discuss their content, it is far more interesting to investigate these passion plays through their development from 1931 when they began. Through this we can gain insight into the manner in which a social and cultural phenomenon such as a passion play can play a role in the maintenance and even the imposition of a particular world view. For the quality of the text and performance of passion plays are less important than the manner in which a community, usually a small one, driven by a communal ideal, expresses religious feelings which tens of thousands of spectators share. In such a performance there is communal activity with a ritual character. Performers are frequently anonymous and spectators and critics set aside any criticism of individual acting or the text because a passion play entails more than merely a large-scale theatrical performance by enthusiastic amateurs.

scholarly journals High mobility SiMOSFETs fabricated in a full 300 mm CMOS process

2021 ◽  
Author(s):  
Timothy Camenzind ◽  
Asser Elsayed ◽  
Fahd Mohiyaddin ◽  
Ruoyu Li ◽  
Stefan Kubicek ◽  
...  
Keyword(s):  
Large Scale ◽  
Quantum Information Processing ◽  
High Mobility ◽  
Cmos Process ◽  
High Quality ◽  
Si Substrates ◽  
Material Optimization ◽  
Underlying Mechanisms ◽  
Insight Into

Abstract The quality of the semiconductor-barrier interface plays a pivotal role in the demonstration of high quality reproducible quantum dots for quantum information processing. In this work, we have measured SiMOSFET Hall bars on undoped Si substrates in order to investigate the device quality. For devices fabricated in a full CMOS process and of very thin oxide below a thickness of \unit[10]{nm}, we report a record mobility of \unit[$17.5\times 10^{3}$]{cm$^2$/Vs} indicating a high quality interface, suitable for future qubit applications. We also study the influence of gate materials on the mobilities and discuss the underlying mechanisms, giving insight into further material optimization for large scale quantum processors.

Creating Contemporary Ritual: The Choreography of Lin Lee-Chen and Anna Halprin

2008 ◽  
Vol 40 (S1) ◽  
pp. 252-262
Author(s):  
Sheenru Yong
Keyword(s):  
Large Scale ◽  
Close Reading ◽  
Ritual Performance ◽  
Distinctive Features ◽  
Performance Quality ◽  
The Earth ◽  
And Performance ◽  
Insight Into ◽  
Shed Light

A study and comparison of works by two creators of ritual performance—Anna Halprin and Lin Lee-Chen—provide insight into Richard Schechner's efficacy-entertainment continuum as well as how ritual manifests in contemporary performance. Through a close reading of the structure and performance quality of Lin's Miroirs de Vie (Jiao) and Halprin's Circle the Earth “Dancing with Life on the Line,” I look at both artist's efforts and results in creating ritual performance and illustrate what I believe to be their distinctive features. Contextualization of the work and the artists' intentions shed light on the possibility or scope of change effected by their creations. While Lin's highly stylized large-scale dance-dramas in many senses cannot be compared to Halprin's nature-oriented participatory community rituals, commonalities in these two works show a strong emphasis on bodily experience, indicating embodiment as fundamental in creating transformative performance.

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