T-Spanner Problem

2017 ◽  
pp. 1-21
Author(s):  
Riham Moharam ◽  
Ehab Morsy ◽  
Ismail A. Ismail
Keyword(s):  
Communication Networks ◽  
Spanning Tree ◽  
Weighted Graph ◽  
Combinatorial Optimization Problem ◽  
Stretch Factor ◽  
A Value ◽  
Shortest Distance ◽  
Distance Approximation ◽  
Maximum Stretch

The t-spanner problem is a popular combinatorial optimization problem and has different applications in communication networks and distributed systems. This chapter considers the problem of constructing a t-spanner subgraph H in a given undirected edge-weighted graph G in the sense that the distance between every pair of vertices in H is at most t times the shortest distance between the two vertices in G. The value of t, called the stretch factor, quantifies the quality of the distance approximation of the corresponding t-spanner subgraph. This chapter studies two variations of the problem, the Minimum t-Spanner Subgraph (MtSS) and the Minimum Maximum Stretch Spanning Tree(MMST). Given a value for the stretch factor t, the MtSS problem asks to find the t-spanner subgraph of the minimum total weight in G. The MMST problem looks for a tree T in G that minimizes the maximum distance between all pairs of vertices in V (i.e., minimizing the stretch factor of the constructed tree). It is easy to conclude from the literatures that the above problems are NP-hard. This chapter presents genetic algorithms that returns a high quality solution for those two problems.

T-Spanner Problem

2021 ◽  
pp. 355-374
Author(s):  
Riham Moharam ◽  
Ehab Morsy ◽  
Ismail A. Ismail
Keyword(s):  
Communication Networks ◽  
Spanning Tree ◽  
Weighted Graph ◽  
Combinatorial Optimization Problem ◽  
Stretch Factor ◽  
A Value ◽  
Shortest Distance ◽  
Distance Approximation ◽  
Maximum Stretch

The t-spanner problem is a popular combinatorial optimization problem and has different applications in communication networks and distributed systems. This chapter considers the problem of constructing a t-spanner subgraph H in a given undirected edge-weighted graph G in the sense that the distance between every pair of vertices in H is at most t times the shortest distance between the two vertices in G. The value of t, called the stretch factor, quantifies the quality of the distance approximation of the corresponding t-spanner subgraph. This chapter studies two variations of the problem, the Minimum t-Spanner Subgraph (MtSS) and the Minimum Maximum Stretch Spanning Tree(MMST). Given a value for the stretch factor t, the MtSS problem asks to find the t-spanner subgraph of the minimum total weight in G. The MMST problem looks for a tree T in G that minimizes the maximum distance between all pairs of vertices in V (i.e., minimizing the stretch factor of the constructed tree). It is easy to conclude from the literatures that the above problems are NP-hard. This chapter presents genetic algorithms that returns a high quality solution for those two problems.

Evaluation of the Properties of Humus Liquid of Earthworm Eisenia Foetida Obtained from Different Rachis

2017 ◽  
Vol 3 (02) ◽  
Author(s):  
Ramiro Remigio Gaibor Fernández ◽  
Abraham Adalberto Bayas Zamora ◽  
Galo Israel Muñoz Sánchez ◽  
Cristhian Adrián Rivas Santacruz
Keyword(s):  
Plant Growth ◽  
Fulvic Acids ◽  
Cattle Manure ◽  
Eisenia Foetida ◽  
Humic And Fulvic Acids ◽  
Livestock Manure ◽  
A Value ◽  
The One ◽  
Liquid Slurry

The objective of the present investigation was to evaluate the physical characteristics of the vermicompost and the quality of the purine of the red Californian (Eisenia foetida) using different substrates of feed for these worms. For this purpose, nine treatments were studied: 75% African palm rachis + 25% cattle manure, 50% African palm rachis + 50% cattle manure, 25% African palm rachis + 75% livestock manure, 50% manure of cattle, 50% of manure of cattle, 25% of manure of cattle, 50% of manure of cattle, 50% of manure of cattle, 50% of rach of coconut + 50% of manure of Livestock, 25% coccus rachis + 75% livestock manure. The substrate made up of 50% of rachis of coconut and 50% of livestock manure can be used in nurseries or nurseries for being the one that registered a value of pH 7.3 plus the closest to the neutral compared to the others, besides this (75% of oil palm rachis and 25% of cattle manure) showed a higher content of humic and fulvic acids (0.87 and 0.45 p / p, respectively), compounds that are important for agriculture by stimulating plant growth, in addition to this reflection 0.06% sulfur content, 4.0 ppm boron, 7.0 ppm copper, 47.5 ppm iron, 6.0 ppm manganese, with a presence of microorganisms of the species Trichoderma, Penicillium, Cladosporium sp. in amounts of 1.91x105 UFC / ml, however in this substrate was obtained between 13.3 and 43.5% less liquid slurry in Comparison with other treatments.

DAYA SAING EKSPOR PRODUK CPO INDONESIA DAN POTENSI HILIRISASI DIOLAH MENJADI BIODIESEL

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Danar Agus Susanto
Keyword(s):  
Palm Oil ◽  
Comparative Advantage ◽  
Global Market ◽  
National Standard ◽  
Revealed Comparative Advantage ◽  
Crude Palm Oil ◽  
A Value ◽  
World Demand ◽  
Domestic Use

ABSTRACTIndonesia is the world's largest producer of crude palm oil (CPO). Even so, the trend of international trade in Indonesian CPO products has decreased in the last 10 years with a value of -10.19%. The decline in world demand for CPO can be dealt with by utilizing CPO as a biofuel for domestic use, like biodiesel. The purpose of this study is to determine the competitiveness of Indonesian CPO in global trade and determine the parameters of the quality requirements of CPO and biodiesel. The competitiveness analysis method uses the Revealed Comparative Advantage (RCA) method, while the analysis of the potential quality of CPO as a biofuel is carried out by analyzing the Indonesian National Standard (SNI). CPO trade in the global market is controlled by Indonesia with a market share of 50% and Malaysia 25.6%, with the declining trade trend in the last 10 years relatively (2010-2019) of -6.91%. The level of competitiveness of Indonesian CPO products in 2019 is very strong, but on average in the last 10 years, the level of competitiveness of Indonesian CPO is no better than that of Malaysia. Indonesia has SNI 01-2901-2006 and SNI 7182: 2015 as a determinant of the quality of CPO and biodiesel products developed in Indonesia so that the CPO and biodiesel produced fullfil sacurity and safety aspects when used by consumers.Keywords: crude palm oil (CPO), competitivenessv, quality, Indonesian National Standard (SNI) ABSTRAKIndonesia merupakan negara produsen minyak kelapa sawit mentah/ Crude Palm Oil (CPO) terbesar di dunia. Meskipun demikian, tren perdagangan internasional produk CPO Indonesia mengalami penurunan dalam sepuluh tahun terakhir dengan nilai -10,19%. Penurunan permintaan dunia terhadap CPO, dapat disiasati dengan memanfaatkan CPO sebagai bahan bakar nabati untuk keperluan dalam negeri sebagai biodiesel. Tujuan penelitian ini adalah mengetahui daya saing CPO Indonesia dalam perdagangan global dan mengetahui parameter persyaratan mutu CPO dan biodiesel. Metode analisis daya saing menggunakan metode Revealed Comparative Advantage (RCA), sedangkan analisis potensi kualitas CPO sebagai biofuel dilakukan dengan menganalisis Standar Nasional Indoensia (SNI). Perdagangan CPO dalam pasar global dikuasai oleh Indonesia dengan pangsa pasar 50% dan Malaysia 25,6%, dengan tren perdagangan relatif menurun dalam 10 tahun terakhir (2010-2019) sebesar -6,91%. Tingkat daya saing produk CPO Indonesia pada tahun 2019 sangat kuat, namun secara rata-rata dalam 10 tahun terakhir, tingkat daya saing CPO Indonesia tidak lebih baik dari Malaysia. Indonesia memiliki SNI 01-2901-2006 dan SNI 7182:2015 sebagai penentu kualitas produk CPO dan biodiesel yang dikembangkan di Indonesia, sehingga CPO dan biodiesel yang dihasilkan memenuhi aspek keamanan dan keselamatan ketika digunakan oleh konsumen.Kata kunci: crude palm oil (CPO), daya saing, kualitas, Standar Nasional Indonesia (SNI)

Simulation modeling of packet switching network segment functioning

2019 ◽  
pp. 75-82
Author(s):  
D. V. Shelkovoy ◽  
A. A. Chernikov
Keyword(s):  
Quality Of Service ◽  
Communication Networks ◽  
Simulation Modeling ◽  
Data Stream ◽  
Switching Network ◽  
Data Packets ◽  
Channel Resource ◽  
Switching Node ◽  
Joint Examination

The testing results of required channel resource mathematical estimating models for the for serving the proposed multimedia load in packet-switched communication networks are presented in the article. The assessment of the attainable level of quality of service at the level of data packet transportation was carried out by means of simulation modeling of the functioning of a switching node of a communication network. The developed modeling algorithm differs from the existing ones by taking into account the introduced delay for processing each data stream packet arriving at the switching node, depending on the size of the reserved buffer and the channel resource for its maintenance. A joint examination of the probability of packet loss and the introduced delay in the processing of data packets in the border router allows a comprehensive assessment of the quality of service «end to end», which in turn allows you to get more accurate values of the effective data transmitted rate by aggregating flows at the entrance to the transport network.

The effectiveness of a digital pelvic floor training program in thetreatment of urinary incontinence – a real-world evaluation (Preprint)

2019 ◽  
Author(s):  
Sabine Keim ◽  
Alexandra von Au ◽  
Lina Maria Matthies ◽  
Stephanie Wallwiener ◽  
Sarah Brugger ◽  
...  
Keyword(s):  
Urinary Incontinence ◽  
Pelvic Floor ◽  
University Hospital ◽  
First Line ◽  
First Line Therapy ◽  
A Value ◽  
Pelvic Floor Training ◽  
Significant Impairment ◽  
Pelvic Floor Weakness

BACKGROUND Background: Many women experience urinary incontinence (UI) during andafter pregnancy due to pelvic floor weakness. First-line therapy is conservative treatment, which nowadays can be facilitated by using digitalsolutions. OBJECTIVE The aim ofthe present study was to investigate the efficacy and effectiveness of pelvinain patients with existing UI. METHODS Methods: In the present observational study we analyzed the effectivenessof pelvina, a certified digital pelvic floor training course, in reducing UI symptoms by regularly applying “The Questionnaire for Urinary Incontinence Diagnosis” (QUID) and furthermore examining quality of life (QoL) by conducting the SF-6D. RESULTS Results: In this prospective study, 373 patients with a median age of 36 years (IQR 33 - 47 years) were included. At baseline the patients had a median QUID of 11 (IQR 11 - 15). During the course, incontinence improved significantly to a QUID of 5 (IQR 2 – 11; p<0.001). Additionally, the patients had also shown a significant impairment in their QoL at baseline with a value of 19 (IQR 16 - 22) in SF-6D. After completing the course, the QoL had risen to 24 (IQR 20 - 26). CONCLUSIONS Conclusion: Use of the certified digital pelvic floor course pelvinasignificantly reduces existing UI due to pelvic floor weakness over the timespan of the course. At the same time QoL is significantly improved. CLINICALTRIAL The present study was approved by the ethics committee of the Heidelberg University Hospital (S-392/2019)

scholarly journals Converting MST to TSP Path by Branch Elimination

2020 ◽  
Vol 11 (1) ◽  
pp. 177
Author(s):  
Pasi Fränti ◽  
Teemu Nenonen ◽  
Mingchuan Yuan
Keyword(s):  
Spanning Tree ◽  
Closed Loop ◽  
Minimum Spanning Tree ◽  
Travelling Salesman Problem ◽  
Open Loop ◽  
Travelling Salesman ◽  
Elimination Algorithm ◽  
Number Of Iterations ◽  
Number Of Branches

Travelling salesman problem (TSP) has been widely studied for the classical closed loop variant but less attention has been paid to the open loop variant. Open loop solution has property of being also a spanning tree, although not necessarily the minimum spanning tree (MST). In this paper, we present a simple branch elimination algorithm that removes the branches from MST by cutting one link and then reconnecting the resulting subtrees via selected leaf nodes. The number of iterations equals to the number of branches (b) in the MST. Typically, b << n where n is the number of nodes. With O-Mopsi and Dots datasets, the algorithm reaches gap of 1.69% and 0.61 %, respectively. The algorithm is suitable especially for educational purposes by showing the connection between MST and TSP, but it can also serve as a quick approximation for more complex metaheuristics whose efficiency relies on quality of the initial solution.

scholarly journals Measuring Key Quality Indicators in Cloud Gaming: Framework and Assessment Over Wireless Networks

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1387
Author(s):  
Oswaldo Sebastian Peñaherrera-Pulla ◽  
Carlos Baena ◽  
Sergio Fortes ◽  
Eduardo Baena ◽  
Raquel Barco
Keyword(s):  
Communication Networks ◽  
Mobile Networks ◽  
Video Game ◽  
Know How ◽  
Fifth Generation ◽  
New Generation ◽  
Graphics Rendering ◽  
The Impact

Cloud Gaming is a cutting-edge paradigm in the video game provision where the graphics rendering and logic are computed in the cloud. This allows a user’s thin client systems with much more limited capabilities to offer a comparable experience with traditional local and online gaming but using reduced hardware requirements. In contrast, this approach stresses the communication networks between the client and the cloud. In this context, it is necessary to know how to configure the network in order to provide service with the best quality. To that end, the present work defines a novel framework for Cloud Gaming performance evaluation. This system is implemented in a real testbed and evaluates the Cloud Gaming approach for different transport networks (Ethernet, WiFi, and LTE (Long Term Evolution)) and scenarios, automating the acquisition of the gaming metrics. From this, the impact on the overall gaming experience is analyzed identifying the main parameters involved in its performance. Hence, the future lines for Cloud Gaming QoE-based (Quality of Experience) optimization are established, this way being of configuration, a trendy paradigm in the new-generation networks, such as 4G and 5G (Fourth and Fifth Generation of Mobile Networks).

693. A rejection test for raw milk

1958 ◽  
Vol 25 (1) ◽  
pp. 32-51 ◽  
Author(s):  
Peggy B. Taylor ◽  
L. F. L. Clegg
Keyword(s):  
Lactic Acid ◽  
Ferric Chloride ◽  
Technical Assistance ◽  
Milk Proteins ◽  
Raw Milk ◽  
Ph Change ◽  
Yellow Colour ◽  
A Value ◽  
Keeping Quality

The determination of apparent lactic acid has been used as a basis for a rejection test for raw milk. The method consists of precipitation of milk proteins with barium chloride, sodium hydroxide and zinc sulphate, and the addition of ferric chloride to the filtrate to produce the yellow colour of ferric lactate. Lactic acid is not solely responsible for the production of the yellow colour, which, nevertheless, gives a good relationship with keeping quality of milk (measured as hours to the C.O.B. end-point at 22° C.) and the values have been expressed as ‘apparent lactic acid’.The relationship of winter and summer milks to keeping quality has been studied, and a value of 0·03% apparent lactic acid in milk is equivalent to an average keeping quality of 5¾ and 8½ hr. for winter and summer milks, respectively. A value of 0·03% is recommended as the earliest value of apparent lactic acid at which milk could be rejected.The apparent lactic acid in colostrum and late-lactation milk and in milk from cows suffering from mastitis has been determined, and only in late-lactation milk were the values found to be significantly higher than usual in fresh raw milk, and an inverse relationship between yield and apparent lactic acid is suggested.Permanent glass matching disks have been prepared for use in a Lovibond comparator. This permits the intensity of the yellow colour produced with 1% ferric chloride to be determined and the apparent lactic acid in milk estimated.Grateful acknowledgement is made to the management and staff of the Dairy Department of the Reading Co-operative Society and the Farmer's Clean Milk Dairy, Reading, and local milk producers for supplying samples for experiments; to the N.M.T.S. staff in Reading for help in finding suitable farmers, and to the Dairy Husbandry Department of the N.I.R.D. for information about and samples of abnormal and late-lactation milk. Our particular thanks are due Miss Marie Gruber for technical assistance, to Dr N. J. Berridge for the suggestion and help on the work on pH change as an indication of keeping quality (given in the appendix), and to Dr A. T. R. Mattick for the advice given in this work.

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