Optimal Solution of a Target Defense Game with Two defenders and a Faster Intrude

2020 ◽  
pp. 1-16
Author(s):  
Han Fu ◽  
Hugh H.-T. Liu
Keyword(s):  
Singular Point ◽  
Complete Solution ◽  
Optimal Solution ◽  
Optimal Trajectories ◽  
Second Phase ◽  
Target Area ◽  
Differential Game Theory ◽  
Capture Range ◽  
Two Phases ◽  
Circular Target

A target defense game with two defenders and a faster intruder is solved based on the classic differential game theory. In the game, the intruder seeks to enter a circular target area, while the defenders endeavor to capture it outside of the target. Under the faster intruder assumption, the game has two phases, where the optimal trajectories are straight and curved, respectively. In the second phase, a peculiar phenomenon exists where the intruder moves at the edge of one defender’s capture region, yet this defender cannot force capture. Because of this, the terminal states of the game are singular, therefore the standard method of integrating optimal trajectories from terminal states is not applicable. The way to circumvent this singularity is to solve the optimal trajectories of a two-player game between the intruder and the closer defender, and assemble them with the trajectory of the other defender. The key contribution of this paper is the solution of the intruder-closer-defender subgame against a circular target area. In the vector field of the optimal trajectories, two singular surfaces and a singular point are observed. Each singular surface indicates a discontinuity in the closer defender’s control, while the singular point represents a situation where the target is successfully protected by a single defender. The complete solution of the two-defender game is solved based on the result of the intruder-closer-defender subgame. The proposed solution is verified through a special case where the capture range is zero. This verification also presents a simpler approach of solving the zero capture range problem.

A UNIFORM ENHANCEMENT APPROACH FOR OPTIMIZATION ALGORITHMS: SMOOTHING FUNCTION METHOD

2010 ◽  
Vol 24 (07) ◽  
pp. 1111-1131 ◽  
Author(s):  
YUPING WANG
Keyword(s):  
Objective Function ◽  
Optimization Algorithm ◽  
Function Method ◽  
Optimization Algorithms ◽  
Initial Point ◽  
Optimal Solution ◽  
Smoothing Function ◽  
Second Phase ◽  
Original Function ◽  
Two Phases

In this paper, we propose a uniform enhancement approach called smoothing function method, which can cooperate any optimization algorithm and improve its performance. The method has two phases. In the first phase, a smoothing function is constructed by using a properly truncated Fourier series. It can preserve the overall shape of the original objective function but eliminate many of its local optimal points, thus it can well approach the objective function. Then, the optimal solution of the smoothing function is searched by an optimization algorithm (e.g. traditional algorithm or evolutionary algorithm) so that the search becomes much easier. In the second phase, we switch to optimize the original function for some iterations by using the best solution(s) obtained in phase 1 as an initial point (population). Thereafter, the smoothing function is updated in order to approximate the original function more accurately. These two phases are repeated until the best solutions obtained in several successively second phases cannot be improved obviously. In this manner, any optimization algorithm will become much easier in searching optimal solution. Finally, we use the proposed approach to enhance two typical optimization algorithms: Powell direct algorithm and a simple genetic algorithm. The simulation results on ten challenging benchmarks indicate the proposed approach can effectively improve the performance of these two algorithms.

Development of the Strasshof Tief Sour-Gas Field Including Acid-Gas Injection Into Adjacent Producing Sour-Gas Reservoirs

2007 ◽  
Vol 10 (05) ◽  
pp. 572-579 ◽  
Author(s):  
Jens Behrend ◽  
Shelin Chugh ◽  
Robert Aaron McKishnie
Keyword(s):  
Gas Injection ◽  
Optimal Solution ◽  
Second Phase ◽  
Gas Reservoirs ◽  
Gas Field ◽  
Acid Gas ◽  
Analytical Review ◽  
Acid Gas Injection ◽  
Two Phases ◽  
Sour Gas

Summary OMV operates two producing sour-gas reservoirs in lower Austria: the Reyersdorfer dolomite (shallow reservoir) and the Schoenkirchen Uebertief dolomite (deep reservoir). A new, separate reservoir called the Perchtoldsdorfer dolomite (Strasshof Tief field) has been discovered, and options for how its acid gas can be handled are being investigated. The two currently producing reservoirs deliver to a gas plant with a 30-tonne/d sulfur plant. The sulfur plant is too small to accommodate the additional production. OMV has evaluated acid-gas injection as an alternative to a new, larger sulfur plant. Acid gas could be injected into either the Reyersdorfer dolomite or the Schoenkirchen Uebertief dolomite. In either case, injection would be occurring concurrently with production. The intent of this project was to determine at a scoping level if sufficient injectivity and storativity are available in either the Reyersdorfer dolomite or the Schoenkirchen Uebertief dolomite. Compositional modeling and the prognosis of the breakthrough time at the producing wells were carried out to determine the contamination risk to existing production. The simulation work included generating compositional numerical-simulation forecasts of production-rate/composition forecasts under concurrent injection/production scenarios; modeling in-situ miscibility and gravity-separation effects of acid gas; and evaluating risk scenarios for existing production to determine the optimal solution. Introduction OMV's recent discovery of the Strasshof Tief reservoir prompted a review of whether acid-gas injection could be a viable alternative to a new or expanded sulfur plant. The issues were whether to inject into the Reyersdorfer or Schoenkirchen Uebertief reservoirs (Figs. 1a through 1c and Fig. 2), how injection would affect the existing recoveries, when breakthrough would occur, and whether there would be sufficient injectivity and storativity in both reservoirs. A complicating factor in the analysis is that the size of the Strasshof Tief is unknown at this time (testing was scheduled for 2006). The composition of the Strasshof gas is also unknown, but it was estimated on the basis of Modular Formation Dynamic Tester (MDT)* samples from the Perchtoldsdorfer dolomite and the known composition of the adjacent sour-gas reservoirs in the dolomite rock. Our review of the problem was broken into two phases. The initial phase was a brief analytical review to estimate the injectivity and storativity of each reservoir and to assess which reservoir was clearly more suitable. In the second phase, the selected reservoir was simulated to determine breakthrough times and whether there was an impact on recovery. Because of the accelerated schedule of this project, where initial simulation results were necessary to initiate discussions with regulatory agencies and obtain approvals so that 2006 development plans could proceed, it was agreed that geological models would be built for both reservoirs immediately so that the simulation could proceed when a decision was made after the initial review.

Accurate Detection and Quantization of Leaf- Diseases through Soft Computing

2018 ◽  
Vol 1 (1) ◽  
pp. 236-247
Author(s):  
Divya Srivastava ◽  
Rajitha B. ◽  
Suneeta Agarwal
Keyword(s):  
Machine Learning ◽  
Image Processing ◽  
Agricultural Production ◽  
Bacterial Blight ◽  
Early Stage ◽  
Second Phase ◽  
Computationally Efficient ◽  
Stage Of Disease ◽  
Accurate Detection ◽  
Two Phases

Diseases in leaves can cause the significant reduction in both quality and quantity of agricultural production. If early and accurate detection of disease/diseases in leaves can be automated, then the proper remedy can be taken timely. A simple and computationally efficient approach is presented in this paper for disease/diseases detection on leaves. Only detecting the disease is not beneficial without knowing the stage of disease thus the paper also determine the stage of disease/diseases by quantizing the affected of the leaves by using digital image processing and machine learning. Though there exists a variety of diseases on leaves, but the bacterial and fungal spots (Early Scorch, Late Scorch, and Leaf Spot) are the most prominent diseases found on leaves. Keeping this in mind the paper deals with the detection of Bacterial Blight and Fungal Spot both at an early stage (Early Scorch) and late stage (Late Scorch) on the variety of leaves. The proposed approach is divided into two phases, in the first phase, it identifies one or more disease/diseases existing on leaves. In the second phase, amount of area affected by the disease/diseases is calculated. The experimental results obtained showed 97% accuracy using the proposed approach.

Representação e simbolismo: artes visuais na fronteira Brasil/Bolívia

2020 ◽  
Vol 4 (3) ◽  
pp. 286
Author(s):  
Paulo César Antonini de Souza ◽  
Derick Trindade Bezerra
Keyword(s):  
Visual Arts ◽  
Social Order ◽  
Research Field ◽  
Border Region ◽  
Second Phase ◽  
Two Dimensional ◽  
Santa Cruz ◽  
Cultural Conditions ◽  
Two Phases ◽  
America Latina

ResumoTendo por campo de investigação o Festival da América do Sul Pantanal (FASP) em 2018, na cidade de Corumbá (Brasil), objetiva-se identificar a materialidade e conceitos que permeiam as manifestações artísticas bidimensionais nesta região de fronteira, a partir da percepção de artistas da Bolívia. A pesquisa se organizou em duas fases: na primeira foi realizado um levantamento em plataformas online de produções acadêmicas em artes visuais, com foco no trabalho bidimensional, utilizando os descritores “arte popular” e “estética latina” resultando em três artigos. Na segunda fase foram selecionados dois trabalhos de uma artista da Bolívia, participante da mostra “Conexão Santa Cruz”, realizada durante o FASP 2018, que foram analisados em seus níveis representacional e simbólico. Pela interpretação das imagens foi possível construir uma leitura sobre a perspectiva da artista a respeito de suas condições culturais dentro da ordenação social em que se encontra situada.Palavras-chave: Artes Visuais. Arte Popular. Arte Regional. América Latina. Representation and symbolism: visual arts on the Brazil/Bolivia frontierAbstractHaving as research field the Festival da América do Sul Pantanal (FASP) in 2018, in the city of Corumbá (Brazil), the objective is to identify the materiality and concepts that permeate the two-dimensional artistic manifestations in this border region, from the perception of artists from Bolivia. The research was organized in two phases: in the first, a survey was carried out on online platforms of academic productions in visual arts, focusing on two-dimensional work, using the descriptors “arte popular” and “estética latina” resulting in three articles. In the second phase, two works were selected by an artist from Bolivia, participating in the exhibition “Conexão Santa Cruz”, held during FASP 2018, which were analyzed at their representational and symbolic levels. Through the interpretation of the images, it was possible to construct a reading on the artist’s perspective regarding her cultural conditions within the social order in which she is located.Keywords: Visual Arts. Folk Art. Regional Art. Latin America.Representación y simbolismo: artes visuales en la frontera de Brasil/BoliviaResumenTeniendo como campo de investigación el Festival de Sudamérica Pantanal (FASP) en 2018, en la ciudad de Corumbá (Brasil), el objetivo es identificar la materialidad y conceptos que permean las manifestaciones artísticas bidimensionales en esta región fronteriza, desde la percepción de artistas de Bolivia. La investigación se organizó en dos fases: en la primera, se realizó una encuesta en plataformas online de producciones académicas en artes visuales, con foco en el trabajo bidimensional, utilizando los descriptores “arte popular” y “estética latina” dando como resultado tres artículos. En la segunda fase, dos obras fueron seleccionadas por un artista de Bolivia, participante de la exposición “Conexão Santa Cruz”, realizada durante FASP 2018, que fueron analizadas en sus niveles representativos y simbólicos. A través de la interpretación de las imágenes, fue posible construir una lectura sobre la perspectiva de la artista sobre sus condiciones culturales dentro del orden social en el que se ubica.Palabras clave: Artes Visuales. Arte Popular. Arte Regional. América Latina.

scholarly journals Development and validation of a short version of the Sarcopenia Quality of Life questionnaire: the SF-SarQoL

2021 ◽  
Author(s):  
A. Geerinck ◽  
C. Beaudart ◽  
J.-Y. Reginster ◽  
M. Locquet ◽  
C. Monseur ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Short Form ◽  
Reduction Process ◽  
Community Dwelling ◽  
Short Version ◽  
Second Phase ◽  
Life Questionnaire ◽  
Quality Of Life Questionnaire ◽  
Two Phases

Abstract Purpose To facilitate the measurement of quality of life in sarcopenia, we set out to reduce the number of items in the previously validated Sarcopenia Quality of Life (SarQoL®) questionnaire, and to evaluate the clinimetric properties of this new short form. Methods The item reduction process was carried out in two phases. First, information was gathered through item-impact scores from older people (n = 1950), a Delphi method with sarcopenia experts, and previously published clinimetric data. In the second phase, this information was presented to an expert panel that decided which of the items to include in the short form. The newly created SFSarQoL was then administered to older, community-dwelling participants who previously participated in the SarcoPhAge study. We examined discriminative power, internal consistency, construct validity, test–retest reliability, structural validity and examined item parameters with a graded response model (IRT). Results The questionnaire was reduced from 55 to 14 items, a 75% reduction. A total of 214 older, community-dwelling people were recruited for the validation study. The clinimetric evaluation showed that the SF-SarQoL® can discriminate on sarcopenia status [EWGSOP2 criteria; 34.52 (18.59–43.45) vs. 42.86 (26.56–63.69); p = 0.043], is internally consistent (α = 0.915, ω = 0.917) and reliable [ICC = 0.912 (0.847–0.942)]. A unidimensional model was fitted (CFI = 0.978; TLI = 0.975; RMSEA = 0.108, 90% CI 0.094–0.123; SRMR = 0.055) with no misfitting items and good response category separation. Conclusions A new, 14-item, short form version of the Sarcopenia Quality of Life questionnaire has been developed and shows good clinimetric properties.

scholarly journals SWIPT in mMIMO system with non-linear energy-harvesting terminals: protocol design and performance optimization

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Kui Xu ◽  
Ming Zhang ◽  
Jie Liu ◽  
Nan Sha ◽  
Wei Xie ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Performance Optimization ◽  
Power Transmission ◽  
Base Station ◽  
Second Phase ◽  
Wireless Power ◽  
Half Duplex ◽  
Non Linear ◽  
Two Phases ◽  
And Performance

Abstract In this paper, we design the simultaneous wireless information and power transfer (SWIPT) protocol for massive multi-input multi-output (mMIMO) system with non-linear energy-harvesting (EH) terminals. In this system, the base station (BS) serves a set of uplink fixed half-duplex (HD) terminals with non-linear energy harvester. Considering the non-linearity of practical energy-harvesting circuits, we adopt the realistic non-linear EH model rather than the idealistic linear EH model. The proposed SWIPT protocol can be divided into two phases. The first phase is designed for terminals EH and downlink training. A beam domain energy beamforming method is employed for the wireless power transmission. In the second phase, the BS forms the two-layer receive beamformers for the reception of signals transmitted by terminals. In order to improve the spectral efficiency (SE) of the system, the BS transmit power- and time-switching ratios are optimized. Simulation results show the superiority of the proposed beam-domain SWIPT protocol on SE performance compared with the conventional mMIMO SWIPT protocols.

scholarly journals Development and Evaluation of Direct Paddy Seeder in Puddled Field

2021 ◽  
Vol 13 (5) ◽  
pp. 2745
Author(s):  
Manoj Kumar ◽  
Ritu Dogra ◽  
Mahesh Narang ◽  
Manjit Singh ◽  
Sushant Mehan
Keyword(s):  
Laboratory Testing ◽  
Field Evaluation ◽  
Row Spacing ◽  
Second Phase ◽  
Cell Type ◽  
Inclined Plate ◽  
Seed Damage ◽  
Two Phases ◽  
Almost All ◽  
Different Soils

Manual transplanting, a pre-dominant practice in almost all the paddy growing areas in India, is laborious, burdensome, and has many expenses on raising, settling, and transplanting nursery. The transplanting process’s limitations motivated the replacement of conventional paddy transplanting methods. The study was divided into two phases. The first phase included laboratory testing of three levels of metering mechanisms, namely cell type (M1) with 10 cells grooved around a circular plate having a 13 cm diameter, inclined plate (M2) containing 24 U shaped cells provided on an 18 cm diameter plate, and fluted roller (M3) with 10 flutes on a 5 cm diameter shaft. The testing matrix included a missing index, multiple index, and seed damage with forward speeds (2.5, 3.0, and 3.5 km/h), and pre-germination levels of 24 h soaked (P1), 24 h pre-germinated (P2), and 36 h pre-germinated paddy seeds (P3)). The second phase included selecting the best combination obtained from the laboratory study and developing a new efficient planter for the puddled field. The inclined plate metering mechanism operating at 2.5 km/h for 24 h pre-germinated seeds was reported most efficient from the first phase. Therefore, a self-propelled 8-row planter equipped with an inclined plate metering mechanism having a row-to-row spacing of 22.5 cm was developed, fabricated, and evaluated in the puddled field. The designed planter was assessed on two different soils: sandy loom (ST1) and clay loom (ST2) and at two different hopper fill levels as ½ filled hopper (F1) and ¾ filled hopper (F2). The number of plants per square meter and hill-to-hill spacing was measured. The on-field evaluation revealed that the number of plants per square meter was non-significantly affected by the type of soil but was significantly affected by hopper fill.

scholarly journals XCOVNet: Chest X-ray Image Classification for COVID-19 Early Detection Using Convolutional Neural Networks

2021 ◽  
Author(s):  
Vishu Madaan ◽  
Aditya Roy ◽  
Charu Gupta ◽  
Prateek Agrawal ◽  
Anand Sharma ◽  
...  
Keyword(s):  
Image Classification ◽  
Second Phase ◽  
Two Phase ◽  
X Ray ◽  
The Neural Network ◽  
Rapid Spread ◽  
Chest X Ray ◽  
Polymerase Chain ◽  
Two Phases ◽  
Active Patients

AbstractCOVID-19 (also known as SARS-COV-2) pandemic has spread in the entire world. It is a contagious disease that easily spreads from one person in direct contact to another, classified by experts in five categories: asymptomatic, mild, moderate, severe, and critical. Already more than 66 million people got infected worldwide with more than 22 million active patients as of 5 December 2020 and the rate is accelerating. More than 1.5 million patients (approximately 2.5% of total reported cases) across the world lost their life. In many places, the COVID-19 detection takes place through reverse transcription polymerase chain reaction (RT-PCR) tests which may take longer than 48 h. This is one major reason of its severity and rapid spread. We propose in this paper a two-phase X-ray image classification called XCOVNet for early COVID-19 detection using convolutional neural Networks model. XCOVNet detects COVID-19 infections in chest X-ray patient images in two phases. The first phase pre-processes a dataset of 392 chest X-ray images of which half are COVID-19 positive and half are negative. The second phase trains and tunes the neural network model to achieve a 98.44% accuracy in patient classification.

scholarly journals A Separated Reset Waveform Design for Suppressing Oil Backflow in Active Matrix Electrowetting Displays

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 491
Author(s):  
Linwei Liu ◽  
Pengfei Bai ◽  
Zichuan Yi ◽  
Guofu Zhou
Keyword(s):  
Experimental Data ◽  
Dielectric Layer ◽  
Waveform Design ◽  
Second Phase ◽  
Active Matrix ◽  
Two Phases ◽  
Back Stage ◽  
A Charge ◽  
Electric Field Force ◽  
Driving Waveform

The electrowetting display (EWD) is a kind of reflective paper-like display. Flicker and grayscale distortion are caused by oil backflow, which is one of the important factors restricting the wide application of EWDs. The charge embedding caused by the electric field force in the dielectric layer is the cause of oil backflow. To suppress oil backflow, a separated reset waveform based on the study of oil movement is proposed in this paper. The driving waveform is divided into two parts: a reset waveform and a grayscale waveform. The reset waveform generated by a reset circuit can be used to output various voltages. The grayscale waveform is set as a traditional PWM waveform. The reset waveform is composed of a charge-releasing stage and oil-moving back stage. Two phases are contained in the charge releasing stage. The overdriving voltage is used during the first phase to reverse the voltage of all pixels. The trapped charges can then be released from the dielectric layer during the second phase. A higher voltage is used during the oil-moving back stage to drive the oil faster in the pixel. By comparing the experimental data, the oil backflow time is extended 761 times by the reset waveform. The four grayscales can be maintained by the reset waveform after driving for 300 s.

scholarly journals Application of the MEMS Accelerometer as the Position Sensor in Linear Electrohydraulic Drive

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1479 ◽  
Author(s):  
Dominik Rybarczyk
Keyword(s):  
High Price ◽  
Second Phase ◽  
Position Sensor ◽  
Microelectromechanical System ◽  
Mems Accelerometer ◽  
Drive Control ◽  
Electrohydraulic Drive ◽  
Preliminary Research ◽  
Two Phases ◽  
Correction Phase

Various distance sensors are used as measuring elements for positioning linear electrohydraulic drives. The most common are magnetostrictive transducers or linear variable differential transformer (LVDT) sensors mounted inside the cylinder. The displacement of the actuator’s piston rod is proportional to the change in the value of the current or voltage at the output from the sensor. They are characterized by relatively low measurement noise. The disadvantage of presented sensors is the need to mount them inside the cylinders and the high price. The article presents preliminary research on the replacement of following sensors and the use of a microelectromechanical system (MEMS) accelerometer as a measuring element in the electrohydraulic drive control system. The control consisted of two phases: at first, the signal from the acceleration sensor was analyzed during the actuator movement, based on the value determined from the simplified model implemented on the controller. In the range of motion in which the dynamics were the lowest, the signal was integrated and the obtained value was used in the second phase of motion. In the correction phase, a new set point was determined. Conducting the research required building a dedicated research stand. The author conducted the simulation and experimental research.

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