13,205 results
Search Results
2. Discussion of Paper 'Improved Explicit Integration Algorithms for Structural Dynamic Analysis with Unconditional Stability and Controllable Numerical Dissipation' by Chinmoy Kolay & James M. Ricles, Journal of Earthquake Engineering 2017, http://www.tandfonline.com/loi/ueqe20
- Author
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Chang, Shuenn-Yih, Veerarajan, S., and Wu, Tsui-Huang
- Subjects
- *
EARTHQUAKE engineering , *STEADY-state responses , *DIFFERENCE equations , *ALGORITHMS - Abstract
Although it was claimed that the MKR-α method can improve the overshoot and nonlinear stability characteristics of the KR-α method, it seems that it still has a high frequency overshoot in steady-state responses and a weak instability. Three examples are applied to numerically illustrate the two adverse properties. A loading-correction term is introduced into the displacement difference equation to remove the adverse overshoot in high frequency steady-state responses. Besides, it is analytically verified that the MKR-α method has an adverse weak instability. Although the problem of high frequency overshoot in steady-state responses can be overcome, there is no way to eliminate the adverse weak instability for both the KR-α method and MKR-α method. Thus, the applications of the two families of integration methods are very limited. It is demonstrated that a high frequency numerical damping is incapable of mitigating the overshoot caused by a weak instability. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
3. Variations on a Theme in Paper Folding.
- Author
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Polster, Burkard
- Subjects
- *
PAPER folding (Graphic design) , *APPROXIMATION theory , *ANGLES , *ALGORITHMS , *POLYGONS , *MATHEMATICS - Abstract
Summarizes the construction of paper folding. Method for approximating rational subdivisions or arbitrary angles and line segments; Angle-folding algorithm; Approximating angles, regular polygons and star polygons; Dissection of angles into equal parts.
- Published
- 2004
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- View/download PDF
4. Scholarly paper recommendation based on social awareness and folksonomy.
- Author
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Asabere, Nana Yaw, Xia, Feng, Meng, Qinxue, Li, Fengqi, and Liu, Haifeng
- Subjects
FOLKSONOMIES ,CONFERENCES & conventions ,SOCIAL learning ,SOCIAL networks ,ALGORITHMS - Abstract
The significant proliferation of research papers in both conferences and journals has made it difficult for researchers to easily access relevant scholarly papers for academic learning. This has been a substantial problem for many researchers. Conferences, in comparison with journals, have an aspect of social learning and networking, which leads to personal familiarisation through various interactions among researchers. In this paper, we improve the social awareness of conference participants by proposing a novel folksonomy-based paper recommendation algorithm, called socially aware recommendation of scholarly papers (SARSP). SARSP recommends papers issued by active participants (APs), to other Group Profile Participants at the same conference based on preference similarity of their research interests. In addition, SARSP computes the social ties between an AP and other conference participants to effectively generate social recommendations of scholarly papers. We evaluate our proposed algorithm using a real-world data-set. Our experimental results confirm that SARSP has significant improvement over other existing methods. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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- View/download PDF
5. The algorithm at work? Explanation and repair in the enactment of similarity in art data.
- Author
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Sachs, S. E.
- Subjects
- *
ALGORITHMS , *PAPER arts , *INTERNET marketing , *IMAGE databases , *EMERGING markets , *ELECTRIC breakdown - Abstract
This paper examines the work practices involved in making data legible to machines and machine output legible to humans. The study is based on ethnographic research of a team of art experts at DNArt – a data classification system that features a growing database of art images, a classification scheme, a similarity matching algorithm, and a website that together serve as a consumer judgment device in an emerging online market for art. I analyze interactions from meeting observations, interviews, documentation, and online interaction data to show how non-technical art experts explain and repair sociotechnical breakdowns – when their expectations for similarity between art images and artists differ from the similarity relations produced by the algorithm. By repairing breakdowns, the art experts construct the algorithm anew, as a legitimate revealer of similarity in art. In doing so, the team's repair work is folded back into the black box of the algorithm, rendering it invisible and unacknowledged, sometimes even by the experts themselves. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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- View/download PDF
6. Assessment of completion of early medical abortion using a text questionnaire on mobile phones compared to a self-administered paper questionnaire among women attending four clinics, Cape Town, South Africa.
- Author
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Constant, Deborah, de Tolly, Katherine, Harries, Jane, and Myer, Landon
- Subjects
- *
ABORTION , *ALGORITHMS , *COUNSELING , *HEALTH services accessibility , *INTERVIEWING , *OBSTETRICAL extraction , *QUESTIONNAIRES , *RESEARCH funding , *SELF-evaluation , *STATISTICS , *RANDOMIZED controlled trials , *SMARTPHONES , *MISOPROSTOL - Abstract
In-clinic follow-up to assess completion of medical abortion is no longer a requirement according to World Health Organization guidance, provided adequate counselling is given. However, timely recognition of ongoing pregnancy, complications or incomplete abortion, which require treatment, is important. As part of a larger trial, this study aimed to establish whether women having a medical abortion could self-assess whether their abortion was complete using an automated, interactive questionnaire on their mobile phones. All 469 participants received standard abortion care and all returnees filled in a self-assessment on paper at clinic follow-up 2–3 weeks later. The 234 women allocated to receive the phone messages were also asked to do a mobile phone assessment at home ten days post-misoprostol. Completion of the mobile assessment was tracked by computer and all completed assessments, paper and mobile, were compared to providers’ assessments at clinic follow-up. Of the 226 women able to access the mobile phone assessment, 176 (78%) completed it; 161 of them (93%) reported it was easy to do so. Neither mobile nor paper self-assessments predicted all cases needing additional treatment at follow-up. Prediction of complete procedures was good; 71% of mobile assessments and 91% of paper assessments were accurate. We conclude that an interactive questionnaire assessing completion of medical abortion on mobile phones is feasible in the South African setting; however, it should be done later than day 10 and combined with an appropriate pregnancy test to accurately detect incomplete procedures. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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7. Dual algorithm for truncated fractional variation based image denoising.
- Author
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Liang, Haixia and Zhang, Juli
- Subjects
ALGORITHMS ,IMAGE denoising ,IMAGE reconstruction ,IMAGE processing ,COMPUTER science ,PAPER arts - Abstract
Fractional-order derivative is attracting more and more attention of researchers in image processing because of its better property in restoring more texture than the total variation. To improve the performance of fractional-order variation model in image restoration, a truncated fractional-order variation model was proposed in Chan and Liang [Truncated fractional-order variation model for image restoration, J. Oper. Res. Soc. China]. In this paper, we propose a dual approach to solve this truncated fractional-order variation model on noise removal. The proposed algorithm is based on the dual approach proposed by Chambolle [An algorithm for total variation minimisation and applications, J. Math Imaging Vis. 20 (2004), pp. 89–97]. Conversely, the Chambolle's dual approach can be treated as a special case of the proposed algorithm with fractional order α = 1. The work of this paper modifies the result in Zhang et al. [Adaptive fractional-order multi-scale method for image denoising, J. Math. Imaging Vis. 43(1) (2012), pp. 39–49. Springer Netherlands 0924–9907, Computer Science, pp. 1–11, 2011], where the convergence is not analysed. Based on the truncation, the convergence of the proposed dual method can be analysed and the convergence criteria can be provided. In addition, the accuracy of the reconstruction is improved after the truncation is taken. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
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8. Comment on the paper "A new LRBFCM-GBEM modeling algorithm for general solution of time fractional-order dual phase lag bioheat transfer problems in functionally graded tissues," Mohamed Abdelsabour Fahmy, Numerical Heat Transfer, Part A: Applications 2019, vol. 75, no. 9, pp. 616-626
- Author
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Pantokratoras, Asterios
- Subjects
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HEAT transfer , *ALGORITHMS - Abstract
The two basic equations in the mentioned article are wrong. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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9. USING EVOLUTIONARY ALGORITHMS TO OPTIMIZE ANTHROPOGENIC MATERIAL STREAMS.
- Author
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Pollmann, Olaf
- Subjects
ALGORITHMS ,ALGEBRA ,ARTIFICIAL intelligence ,INTELLIGENT agents ,MACHINE theory - Abstract
To optimize anthropogenic material streams, the production process, as well as the quality of the products, must be known. With knowledge of these requirements, it is possible to use extra applied algorithms—in this case evolutionary algorithms as part of artificial intelligence—for the optimization of these secondary material streams. The benefit of this application is the fast and precise calculation of the local and global optima of the optimizing problem. This calculation method uses the benefits of the biological reproduction by applications of mutation, selection, and recombination to find one of the best results in a huge amount of possible and potential results. For the use of secondary materials in the paper production it could be proven that in spite of high quotes of secondary materials in different paper classes, there are some paper classes in which the amount of secondary material could be raised without losing any quality. [ABSTRACT FROM AUTHOR]
- Published
- 2009
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10. A Paper-and-Pencil gcd Algorithm for Gaussian Integers.
- Author
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Szabó, Sándor
- Subjects
- *
ALGORITHMS , *NUMBER theory , *ERROR analysis in mathematics , *GAUSSIAN sums , *RINGS of integers , *DIVISOR theory - Abstract
The article focuses on the number theory of Gaussian integers. Within the complex numbers, the analogues of the integers are the Gaussian integers, those complex numbers whose real and imaginary parts are both integers. There is a theory of divisibility, including greatest common divisors, and the purpose of this article is to present a new gcd algorithm for Gaussian integers. The standard algorithm is a straightforward extension of the Euclidean algorithm for ordinary integers. The gcd algorithm is better suited to paper-and-pencil computation, and it is less error-susceptible than the standard one. Another attractive feature is that it is based on a simple parity argument. The basic divisibility definitions for Gaussian integers are simply restatements of those for ordinary integers. There are many interesting results which can be proved using parity arguments. The gcd algorithm establishes that any two Gaussian integers have a greatest common divisor, and it is interesting to see that this result has an odd-even proof.
- Published
- 2005
11. Four years of ocean colour remote sensing with MOS-IRS An updated version of a paper originally presented at Oceans from Space 'Venice 2000' Symposium , Venice, Italy, 9-13 October 2000.
- Author
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HETSCHER, MATTHIAS, KRAWCZYK, HARALD, NEUMANN, ANDREAS, and ZIMMERMANN, GERHARD
- Subjects
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SPECTROMETERS , *OCEAN color , *REMOTE sensing , *ATMOSPHERIC radiation , *COASTAL ecology , *ALGORITHMS - Abstract
The imaging spectrometer MOS on IRS-P3 was launched in March 1996 as the first example of a new generation of ocean colour sensors. It consists of three different spectrometers in the visible/near-infrared spectral region with 18 channels. The IRS-P3 mission is focused on the remote sensing of case 2 water, particularly the derivation of different water constituents in coastal waters. Due to the more complex spectral behaviour of case 2 water, a new methodological approach was developed which works directly with satellite measured top-of-atmosphere radiance and accounts for the correlation of the different water constituents as well as for the spectral shape. This paper gives an overview of the mission, the scientific goals and the development and improvement of the retrieval algorithms. The potential of the algorithm is demonstrated and examples of selected European coasts are shown. Derived maps of water constituents are presented. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
12. A genetic algorithm based heuristic for adjacent paper-reel layout problem.
- Author
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Zhang, G. Q., Xue, J., and Lai, K. K.
- Subjects
ALGORITHMS ,LAYOUT (Printing) ,MANUFACTURING cells ,HEURISTIC ,GENETIC algorithms ,COST ,LINEAR programming - Abstract
In this paper, we present an algorithm that solves a paper reel layout problem where the available space is divided into equal-size cells. The problem is to find a layout with the minimum transportation cost subject to adjacency and other constraints. A genetic algorithm is used in a two-stage iterative approach to solve the problem. Computational results seem to indicate the efficiency and effectiveness of the proposed solution method. [ABSTRACT FROM AUTHOR]
- Published
- 2000
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13. Robots and emotion: a survey of trends, classifications, and forms of interaction.
- Author
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Savery, Richard and Weinberg, Gil
- Subjects
EMOTIONS ,EMOTIONAL intelligence ,ROBOTS ,ALGORITHMS ,CLASSIFICATION - Abstract
The use of emotion to drive robotic interaction continues to grow across a range of use cases, from social robotics to increased survivability. Nevertheless, these efforts remain isolated from each other and are not easily compared between papers and projects. To this end an extensive survey of 1427 IEEE and ACM publications was conducted, covering robotics and emotion. The survey first resulted in broad categorizations of key trends covering emotional input and output. This was followed by an extended analysis on 232 papers that focused on the internal processing of emotion, where emotion was handled through some kind of algorithm and not just as an input or output. From this analysis, three broad categories were developed: emotional intelligence, emotional model, and implementation. Emotional intelligence captured the manner in which emotion was handled and included the subcategories: algorithm, mapping, and history. The emotional model category captured the emotion categories and number of emotions used, while the implementation category tracked the role, purpose, and platform. This paper concludes with a summary of key features discovered through the process, future opportunities, and a discussion of the intrinsic challenges emerging from the interaction of emotion and robotics. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
14. Practical sea-water algorithms for fundamental bio-optical and remote sensing quantities An updated version of a paper originally presented at Oceans from Space 'Venice 2000' Symposium , Venice, Italy, 9-13 October 2000.
- Author
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Højerslev, Niels Kristian
- Subjects
- *
SPECTRAL irradiance , *SEAWATER , *REMOTE sensing , *BACKSCATTERING , *ALGORITHMS - Abstract
Spectral in-water measurements of the downward irradiance, E d and the upward irradiance, E u are sufficient in order to calculate the following spectral quantities: the irradiance ratio R , the two scalar irradiances E o and E od , the two average cosines μ and μ d , the light absorption coefficient a , the backscattering coefficient b b and the vertical attenuation coefficients for the above-mentioned downward and upward irradiances. The algorithms are valid for horizontally stratified and optically deep sea waters. [ABSTRACT FROM AUTHOR]
- Published
- 2004
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- View/download PDF
15. Single-wavelength algorithms for in situ or remote sensing estimation of mean pigment concentration An updated version of a paper originally presented at Oceans from Space 'Venice 2000' Symposium , Venice, Italy, 9-13 October 2000.
- Author
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Sokoletsky*, L., Dubinsky, Z., Shoshany§, M., and STAMBLER, N.
- Subjects
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PHYTOPLANKTON , *OPTICAL properties , *RADIATIVE transfer , *REMOTE sensing , *ALGORITHMS - Abstract
The bio-optical relationships between inherent and apparent optical properties, and between optical properties and phytoplankton pigment concentration ( C ) averaged in a layer (Δ Z ), were derived from analysis of data collected during the period 1996-1998 in the Gulf of Aqaba (Eilat). Parametrization of these relationships was based on radiative transfer theory, Gershun's equation, minimization of model errors by least-square fitting, and on known optical models relating underwater remote sensed reflectance ( R rsw ) with the ratio of backscattering ( b b ) to vertical attenuation coefficient ( K d ) [or to absorption coefficient ( a )]. These relationships explain a frequently used form of remote sensing algorithms for C estimation using ratio of water-leaving radiances measured at two or more wavelengths ( λ ). In this study, the possibility of using for this purpose a single wavelength in the blue range ( λ =443 nm) within the framework of in situ and remote sensing algorithms for Case 1 waters was assessed. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
16. Development and applications of STARRS: a next generation airborne salinity imager An updated version of a paper originally presented at Oceans from Space 'Venice 2000' Symposium , Venice, Italy, 9-13 October 2000.
- Author
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Miller*, Jerry L. and Goodberlet, Mark
- Subjects
- *
SALINITY , *SCANNING systems , *WATER temperature , *SURFACE roughness measurement , *ALGORITHMS , *OPTOELECTRONIC devices - Abstract
A new generation of airborne salinity imager, the Salinity Temperature and Roughness Remote Scanner (STARRS), has been designed and is currently under construction with delivery expected shortly. With both significantly lower noise levels and enhanced capability to measure secondary parameters, including sea surface temperature and roughness, STARRS will serve as both an operational survey tool and as a test-bed for refinement of retrieval algorithms. [ABSTRACT FROM AUTHOR]
- Published
- 2004
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17. SeaWiFS data analysis and match-ups with in situ chlorophyll concentrations in Danish waters An updated version of a paper originally presented at Oceans from Space 'Venice 2000' Symposium , Venice, Italy, 9-13 October 2000.
- Author
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Jørgensen, P. V.
- Subjects
- *
DETECTORS , *CHLOROPHYLL , *ALGORITHMS - Abstract
For the year 1999 all Sea viewing Wide Field of view Sensor (SeaWiFS) scenes of the Danish waters from the North Sea to the Baltic Sea were browsed, and a total of 47 SeaWiFS scenes with reasonably low cloud cover and, therefore, potential in situ match-ups were found and processed. The in situ data used as match-ups were collected on routine monitoring cruises by Danish and Swedish environmental authorities. A few stations in the North Sea, Skagerak and the western Baltic Sea were sampled, while most stations were located in Kattegat and the inner Danish waters. A turbid water SeaWiFS atmospheric correction algorithm was applied, since the standard SeaWiFS algorithm for chlorophyll- a (CHL) has been shown to be fairly inaccurate in turbid coastal waters. This is due to both inaccurate atmospheric and to relatively high and variable abundance of yellow substance. The application of the turbid atmospheric correction substantially improved the SeaWiFS CHL estimates. Regressions between SeaWiFS estimates using the OC2 and OC4 algorithms used in the SeaDAS software (versions 3.3 and 4.0, respectively) and in situ CHL values were made as well, and regression with a number of other possible reflectance ratios with SeaWiFS channels. The best correlation was found to be R 2 =0.54 using a double-ratio algorithm using both R510/R555 and R443/R670, while the OC4v4 had the second best correlation of R 2 =0.39. Among other single ratios, the R510/R555 had the highest correlation with CHL, which was expected since this is also the ratio that OC4v4 most often switches to in the waters investigated here. The range of CHL concentrations in this study was rather limited (all but three points from 0.5-3 mg m -3 ) so there is a need for inclusion of more data to expand the concentration range. This should be possible using also data from 2000, 2001 and onwards and, hereafter, a more 'stable' empirical algorithm can be derived for the Danish waters. [ABSTRACT FROM AUTHOR]
- Published
- 2004
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- View/download PDF
18. Normalised fuzzy index for research ranking.
- Author
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Hedar, Abdel-Rahman, Abdel-Hakima, Alaa, and Alotaibi, Youseef
- Subjects
ALGORITHMS ,ARTIFICIAL intelligence ,BIBLIOMETRICS ,IMMUNOLOGY ,RESEARCH methodology ,MOLECULAR biology ,SERIAL publications ,BIBLIOGRAPHIC databases ,STRUCTURAL equation modeling ,ACQUISITION of data ,DESCRIPTIVE statistics ,MANN Whitney U Test - Abstract
There are great interests of designing research metrics and indices to measure the research impacts in research institutes. Unfortunately, most of those indices ignore critical design issues, e.g. the disparity between domains, the impact of journals or conferences in which papers are published, normalising the range of the index values to certain intervals, and the scalability of using the index to rank different research entities. In this paper, a new normalised fuzzy index, (NF
index ), is proposed as a fuzzy-based research impact metric. The proposed index is a scalable index whose values are normalised to the percentage levels. NFindex achieves both inter-discipline normalisation and intra-discipline consistency. The capability of NFindex to achieve the inter-discipline normalisation enables fair comparison between different research domains regardless their nature in terms of influence and contribution to other research areas, e.g. natural science. Therefore, NFindex gives a universal normalised single-number metric that can be used by research institutes to solve the problem of inter-discipline scholar ranking. Moreover, it can help universal ranking of universities and research institutes according to their research capabilities and impacts. The obtained results, on diverse research areas, prove the potential of NFindex in terms of both intra-discipline consistency and inter-discipline normalisation. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
19. A note on the paper ‘Demonstrating Johnson’s algorithm via resource constrained scheduling’.
- Author
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Companys, Ramon and Ribas, Imma
- Subjects
FLOW shop scheduling ,PRODUCTION scheduling ,FLOW shops ,MATHEMATICAL models ,PRODUCTION control ,ALGORITHMS ,MANUFACTURING processes - Abstract
In this paper, we demonstrate that the relation between two jobs defined by min{a
i , bj } ≤ min{bi , aj }, used in Johnson’s theorem, is not transitive. However, both the theorem and Johnson’s algorithm are correct. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
20. Ethical implications of Thai ChatGPT public discourses.
- Author
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Hongladarom, Soraj and Sakprasert, Suppanat
- Subjects
CHATGPT ,ALGORITHMS ,SEMINARS ,ETHICS ,DISCOURSE - Abstract
One of the interesting discourses that has occurred in Thailand as a result of ChatGPT is how the algorithm is exploited in a growing number of workshops and seminars aimed at teaching how to use, or to 'prompt', the algorithm so as to maximise its potential. On the one hand, the organisers of these workshops aim at profiting from the growing demand for ChatGPT. On the other, there is a sense among the Thai public that they must reap the benefit of the technology for their own purposes. This trend seems to be more prominent in Thailand than in the West, where ChatGPT is viewed more with critical outlook. In this paper, we critically examine the perception of ChatGPT in the Thai context, especially when ChatGPT is used as a topic in these workshops. We will also discuss how this situation should lead to a discussion of how ChatGPT should be regulated. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
21. A modified Tseng's extragradient method for solving variational inequality problems.
- Author
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Peng, Jian-Wen, Qiu, Ying-Ming, and Shehu, Yekini
- Subjects
HILBERT space ,POINT set theory ,ALGORITHMS ,VARIATIONAL inequalities (Mathematics) - Abstract
In this paper, we introduce a modified Tseng's extragradient method with a new step-length rule to solve pseudo-monotone variational inequalities in real Hilbert spaces. Under suitable conditions, the sequence generated by this algorithm strongly converges to the common elements of the solution set of pseudo-monotone variational inequality problems and the fixed point set of k-demicontractive mappings. Finally, we give some numerical experiments to illustrate the effectiveness of the proposed algorithm. The main results of this paper generalize and improve some known results in the literature. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
22. Stability-guaranteed odd-order variable-bandwidth filters using stabilized odd-order transfer function.
- Author
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Deng, Tian-Bo
- Subjects
BANDPASS filters ,TRANSFER functions ,BANDWIDTHS ,ALGORITHMS - Abstract
This paper describes a 2-stage tactic for achieving an odd-order variable-bandwidth (OO-VBW) filter with absolutely guaranteed stability. The design methodology aims to minimize the p-norm amplitude-response error while maintaining the OO-VBW-filter's stability. In order to tune OO-VBW filter's amplitude response, we utilize a kind of functions of the bandwidth (BW)-tuning parameter to express the filter's coefficients. Because those functions have changeable function values, the designed OO-VBW-filter's amplitude response possesses variability. Another important concern in this paper is the stability issue. When the filter coefficient values expressed as function values are changed, the OO-VBW filter that has feedback structures may become unstable. This necessitates that the OO-VBW-filter's stability must always be preserved during real-time tuning. In order to stabilize such an OO-VBW filter that has feedback structures, a coefficient-conversion (CC) algorithm is adopted, and it is incorporated into the 2-stage methodology for obtaining the OO-VBW filter. To illustrate both the stability and high approximation accuracy, the design of an OO-VBW bandpass filter is simulated. The simulation details verify that both stability and high accuracy can be successfully achieved. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
23. An optimisation method for anti-blast performance of corrugated sandwich plate structure based on neural network and sparrow search algorithm.
- Author
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Qiu, Wei-Jian, Liu, Kun, Zong, Shuai, Yu, Tong-qiang, Wang, Jia-xia, and Gao, Zhen-guo
- Subjects
BLAST effect ,GENETIC algorithms ,IRON & steel plates ,OPTIMIZATION algorithms ,ALGORITHMS - Abstract
This paper presents an optimization method for the design of marine metal sandwich plates to enhance the anti-blast performance of ship structures. The proposed method combines a neural network with the sparrow search algorithm to efficiently optimize the structure. The orthogonal design method is utilized to select appropriate sample points for the surrogate model. Dynamic responses of the ship under blast loading are obtained using the ABAQUS finite element software. By establishing an anti-blast surrogate model, the optimization problem is simplified. To overcome the limitations of the traditional backpropagation neural network, genetic algorithm and Adam algorithm are employed. Finally, the optimal solution is obtained based on the sparrow search algorithm. The results enable us to determine the structural dimensions with the best blast resistance. The proposed optimisation method can provide inspiration for improving the safety of ships. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
24. Some remarks on a paper on the statistical properties of boolean expressions.
- Author
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Levai, P.
- Subjects
- *
BOOLEAN algebra , *ALGORITHMS , *BOOLEAN expressions - Abstract
Discusses the statistical properties of randomly generated boolean functions. Effect of prime implicant errors in the minimization algorithms; Relationship between the number of variables in the boolean expression on the k-subcube probability to be a prime implicant.
- Published
- 1983
25. 100 Years of the Ubiquitous Traffic Lights: An All-Round Review.
- Author
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Kulkarni, Ashish R., Kumar, Narendra, and Ramachandra Rao, K.
- Subjects
AUTONOMOUS vehicles ,TRAFFIC signs & signals ,TRAVEL delays & cancellations ,RESEARCH personnel ,TRAFFIC engineering - Abstract
Three-colour four-way traffic light completed 100 years in 2020. Even though the traffic light in the form of Semaphore arms has been in use in London since 1868, electric traffic lights came into existence in 1912 and the standard three-colour four-way light in 1920. Research is continuously being carried out to develop better algorithms to improve safety, reduce travel delays, and optimize road capacity. Hence a review of the evolution of traffic lights is warranted. This paper presents an all-round review using a six-prong approach. Timeline of the evolution of the literature in the last 100 years, the evolution of hardware, algorithms, traffic control schemes, standards and the pedestrian lights and count down timer are the six areas in which the review is carried out. A timeline of the different keywords related to the various algorithms in use is presented. This article delves into the thinking and meticulous approach of early researchers and practitioners of the field while dwelling on the past. They laid the rock-solid foundation of today's research. Also, future research areas like connected vehicles and automated vehicles are pointed out, and a summary of the findings is presented at the end. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. Research on Television Series: A Bibliometric Analysis.
- Author
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Segado-Boj, Francisco, Martín-Quevedo, Juan, and Fernández-Gómez, Erika
- Subjects
PUBLISHING ,RESEARCH ,DATABASES ,COMPUTER software ,INTERNATIONAL relations ,PUBLIC relations ,LABOR productivity ,BIBLIOMETRICS ,SERIAL publications ,BIBLIOGRAPHY ,CITATION analysis ,BUSINESS networks ,TELEVISION ,HEALTH ,INTERPROFESSIONAL relations ,BIBLIOGRAPHICAL citations ,COMMUNICATION ,TOURISM ,AUTHORSHIP ,ALGORITHMS - Abstract
With series on conventional television and pay TV platforms now a key element of media consumption, they have gained increasing academic attention in the last decade, both as a main object of study and in combination with other social phenomena. However, the boundaries of this line of research, which draws together researchers from different fields, have become increasingly blurred. This paper undertook a bibliometric investigation to understand how this line of research has come about, what its characteristics are, the main streams within it, and the extent to which the rise in publications reflects a mature and consolidated field of research in its own right. This analysis focused on the development of scientific production on television series indexed by database Scopus between 2010 and 2019 (n = 1,679 documents). More specifically, this study analyzed authorship, journals, national output and international collaboration, co-citation of keywords to ascertain the main intellectual trends in the area and the co-occurrence of references to find out if there is a theoretical body of works that serve as a foundation for this research. The results show symptoms of immaturity, such as a lack of continuity in authority, little concurrence between specialized journals and the most cited authors and works, vagueness in both the keyword clusters and the papers that are often cited together. In addition, a large number of the most cited works come from fields outside Communication that consider television series an accessory aspect of their main theme, such as their impact on the influx of tourists as a result due to the consumption of cultural works. On the other hand, this points to a strong, versatile line of research capable of hosting research on new and old media and related to various topics. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
27. A concise guide to scheduling with learning and deteriorating effects.
- Author
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Pei, Jun, Zhou, Ya, Yan, Ping, and Pardalos, Panos M.
- Subjects
TECHNOLOGICAL innovations ,EVIDENCE gaps ,SCHEDULING ,MANUFACTURING processes ,CRITICAL analysis - Abstract
In practical manufacturing systems, the job processing time usually varies with the performance change of manufacturing resources, among which the learning and deteriorating effects are typical characteristics. Due to the interests from both academic exploration and industrial innovation, the research on scheduling problems with these effects is abundant and diverse. However, some studied problems need to be strengthened in combination with realistic production scenarios. This paper provides a concise guide to scheduling problems with these effects, giving a comprehensive review and critical hints for future research. A novel classification scheme is designed based on four levels of different domains, i.e. effects, processing ways, processing time functions, and manufacturing environments. Based on this scheme, the scheduling problems are first distinguished into three categories: learning effects, deteriorating effects, and combined effects. In each category, models are then refined along three lines: general processing way, batch scheduling, and group scheduling. Combined with the attributes of actual processing time functions and manufacturing environments, the evolvement of related scheduling models and a critical analysis on the proposed algorithms are well analysed. Afterwards, the research gaps are revealed and the research directions are indicated from the perspectives of practical applications, time functions, and designed algorithms. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
28. Novel calibration algorithm of six-port receivers based on radial basis function network.
- Author
-
Wang, Qing, Wu, Yongle, Qi, Yue, Wang, Weimin, and Yang, Qinghua
- Subjects
RADIAL basis functions ,CALIBRATION ,ALGORITHMS ,BUILDING performance - Abstract
In this paper, the radial basis function neural network based on the orthogonal least squares (OLS-RBFNN) method is proposed for the first time for the calibration of the six-port receiver, which realises six-port accurate reception in the true sense. This algorithm overcomes the problems of an ageing circuit, narrow working frequency band and nonlinearity of the six-port receiver hardware. The RBFNN is a three-layer forward network, including an input layer, a hidden layer and an output layer. The transformation function of the hidden layer is the radial basis function. A six-port receiver test platform with an operating frequency band of 2.0–8.0 GHz is built to verify the performance of the six-port receiver based on OLS-RBFNN. The test signal is a 16-QAM signal with different bandwidths and different frequency bands. The test indicator uses error vector magnitude (EVM), which represents the error between the received signal and the ideal signal sent. At last, the EVM of all tested data is less than 1.07%, and the best EVM is 0.57%. Therefore, the calibration accuracy of the OLS-RBFNN proposed in this paper is very high. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Fixed-time bounded control of nonlinear systems without initial-state constraint.
- Author
-
Gao, Hui, Wang, Ziyan, Ma, Jing, and Yin, Le
- Subjects
NONLINEAR systems ,BACKSTEPPING control method ,PROBLEM solving ,COMPUTER simulation ,ITERATIVE learning control ,ALGORITHMS - Abstract
To solve the control problem of time-varying state-scale nonlinear systems whose initial state is not affected by settling time, fixed-time convergence algorithms are proposed for first-order systems and higher-order systems in this paper. First, a scalar model is used to illustrate how the time-varying feedback parameter can guarantee that the system achieves asymptotic stability while achieving finite-time convergence, and it is proved that the settling time obtained in this paper is only related to the prescribed boundary. This allows us to design the settling time with an appropriate parameter based on the prescribed boundary. To exhibit the effectiveness and extensibility of the proposed algorithm for first-order scalar systems, the results are subsequently extended to general higher-order systems based on the backstepping method. By introducing numerical simulation results, this paper verifies that the proposed algorithm will make the system achieve asymptotic stability and its output can converge to a given boundary, regardless of the system's initial states. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. Artificial intelligence in manufacturing and logistics systems: algorithms, applications, and case studies.
- Author
-
Chien, Chen-Fu, Dauzère-Pérès, Stéphane, Huh, Woonghee Tim, Jang, Young Jae, and Morrison, James R.
- Subjects
ARTIFICIAL intelligence ,CYBER physical systems ,ARTIFICIAL neural networks ,OPERATIONS research ,ALGORITHMS ,COGNITIVE computing - Abstract
The papers are grouped into three categories: AI methods for manufacturing systems, AI developments specifically in semiconductor manufacturing, and AI in additive manufacturing and maintenance. They combine a deep neural network model and Markov decision processes (MDP) to rapidly generate near optimal dynamic control policies for problems that are too large to be only solved by MDP, thus showing the potential of machine learning in controlling unreliable manufacturing systems. [Extracted from the article]
- Published
- 2020
- Full Text
- View/download PDF
31. Predicting Money Laundering Using Machine Learning and Artificial Neural Networks Algorithms in Banks.
- Author
-
Lokanan, Mark E.
- Subjects
ARTIFICIAL neural networks ,MONEY laundering ,MACHINE learning ,ALGORITHMS ,RANDOM forest algorithms - Abstract
This paper aims to build a machine learning and a neural network model to detect the probability of money laundering in banks. The paper's data came from a simulation of actual transactions flagged for money laundering in Middle Eastern banks. The main findings highlight that criminal networks mainly use the integration stage to integrate money into the financial system. Fraudsters prefer to launder funds in the early hours, morning followed by the business day's afternoon time intervals. Additionally, the Naïve Bayes and Random Forest classifiers were identified as the two best-performing models to predict bank money laundering transactions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
32. Warning: statistical benchmarking is addictive. Kicking the habit in machine learning.
- Author
-
Drummond, Chris and Japkowicz, Nathalie
- Subjects
ALGORITHMS ,PERFORMANCE evaluation ,MACHINE learning ,PAPER ,MACHINE theory - Abstract
Algorithm performance evaluation is so entrenched in the machine learning community that one could call it an addiction. Like most addictions, it is harmful and very difficult to give up. It is harmful because it has serious limitations. Yet, we have great faith in practicing it in a ritualistic manner: we follow a fixed set of rules telling us the measure, the data sets and the statistical test to use. When we read a paper, even as reviewers, we are not sufficiently critical of results that follow these rules. Here, we will debate what are the limitations and how to best address them. This article may not cure the addiction but hopefully it will be a good first step along that road. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
33. Modelling and solving algorithm for two-stage scheduling of construction component manufacturing with machining and welding process.
- Author
-
Meng, Ronghua, Rao, Yunqing, Zheng, Yun, and Qi, Dezhong
- Subjects
CONSTRUCTION equipment industry ,METAL industry ,ALGORITHMS ,PRODUCTION scheduling ,WELDING ,MACHINING - Abstract
This paper focuses on a two-stage machining and welding scheduling problem based on an investigation at a structural metal manufacturing plant, aiming to minimise the total makespan. Several parts processed at Stage one according to classical job-shop scheduling are grouped into a single construction component at the second welding stage. Fabrication of the construction component cannot begin until all comprising parts have been completed at Stage one. This paper establishes a novel mathematic model to minimise the total makespan by mainly considering the dominance relationship between the construction component and the corresponding parts. In order to solve this two-stage problem, we propose an improved harmony search algorithm. A local search method is applied to the best vector at each iteration, so that a more optimal vector can be subsequently realised. The average value, minimum value, relative percentage deviation and standard deviation are discussed in the experimental section, and the proposed local best harmony search algorithm outperforms the genetic algorithm, immune algorithm and harmony search algorithm without local search. Moreover, six optimal solutions are given as Gantt charts, which vividly illustrate that the mathematical model established in this paper can facilitate the development of a better scheduling scheme. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
34. Spatial scheduling strategy for irregular curved blocks based on the modified genetic ant colony algorithm (MGACA) in shipbuilding.
- Author
-
Ge, Yan and Wang, Aimin
- Subjects
PRODUCTION scheduling ,ANT algorithms ,SHIPBUILDING ,MATHEMATICAL optimization ,ALGORITHMS ,COMPARATIVE studies - Abstract
This paper proposes a scheduling strategy for irregular curved blocks to address the complex spatiotemporal coupling scheduling problem related to the entered time, the entered sequence, the setting positions and the rotated angles for the curved blocks in a shipbuilding yard. The strategy presents a makespan-based curved blocks - classification and selection rule to fulfil the programming time for the entry of the curved blocks into the workplace and realises the suppression on the delay. Useless stepping search of curved blocks in occupied workplace is avoided by combining the lowest centre-of-gravity rule with the calculation method of the remained workplace proposed in this paper. A modified genetic ant colony algorithm was proposed, which apply the ease to premature characteristics of GA and the excellent local optimisation ability of ACO, to let and promote the algorithm falls into local optimum. Then the large-scale and full-range mutation will be implemented to make the algorithm jump out of the original local optimisation to search more local optimal solutions so that the global optimal solution can be achieved. Finally, a software system for algorithm verification was developed which conducts the comparative analysis of the algorithms and verifies the validity of the algorithm proposed. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
35. A modified memetic algorithm with multi-operation precise joint movement neighbourhood structure for the assembly job shop scheduling problem.
- Author
-
Ba, Zhiyong, Yuan, Yiping, and Liu, Jinduo
- Subjects
PRODUCTION scheduling ,RANGE of motion of joints ,NEIGHBORHOODS ,ADAPTIVE control systems ,ALGORITHMS - Abstract
This paper presents an adaptive memetic algorithm based on a new neighbourhood structure (AMA) for solving the assembly job shop scheduling problem, with the aim of minimising the maximum completion time (makespan). To utilise the knowledge of problem, a theoretical analysis is conducted to explore the criteria for feasible and effective movement of operations under assembly constraints, and a multi-operation precise joint movement neighbourhood structure is proposed accordingly. In the AMA, to ensure the feasibility of solutions during the evolution process, a feasible encoding mechanism based on the constraint degree of operations is designed, a greedy active decoding method as well as feasible crossover operation based on independent operation chains are designed specifically for this encoding method. To avoid premature convergence of the population, a population update operator with diversity adaptive control is proposed. Finally, by comparing the results with five state-of-the-art algorithms, the superiority of AMA in terms of solution quality and stability is verified, particularly with the update of known optimal solutions for 11 instances. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
36. A cloud edge-based two-level hybrid scheduling learning model in cloud manufacturing.
- Author
-
Jian, Chengfeng, Ping, Jing, and Zhang, Meiyu
- Subjects
BLENDED learning ,DEEP learning ,SCHEDULING ,RESOURCE allocation ,ALGORITHMS - Abstract
In the Industry 4.0, edge industrial services such as smart robotic services are widely used in smart factory. The workflow of these services mainly consists of task decomposition and resource allocation. The long scheduling time, high communication delay and load imbalance among edge nodes are the challenging problems. Traditional cloud manufacturing platforms are difficult to meet the new requirements. It is hard for the existing scheduling methods to maintain a balance between algorithm complexity and performance. Training scheduling data by deep learning has become a feasible method to achieve fast prediction of the scheduling results. In this paper, a cloud edge-based two-level hybrid scheduling learning model is put forward at first. Then an improved bat scheduling algorithm with interference factors and variable step size (VSSBA) is proposed. And then, according to the historical scheduling data, the improved long and short-term memory networks (LSTM) model is put forward for fast prediction of the cloud-edge collaborative scheduling results. Experiments show that our proposed learning model can improve the performance of the cloud manufacturing platform in real-life applications efficiently. Finally, future research issues and challenges are identified. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
37. A hyperautomative human behaviour recognition algorithm based on improved residual network.
- Author
-
Li, Jianxin, Liu, Jie, Li, Chao, Jiang, Fei, Huang, Jinyu, Ji, Shanshan, and Liu, Yang
- Subjects
HUMAN behavior ,CONVOLUTIONAL neural networks ,ALGORITHMS - Abstract
When dealing with the mutual storage relationship of behavioral features in long time sequence video, the convolutional neural network is easy to miss important feature information. To solve the above problems, this paper proposes a super automatic algorithm combining nonlocal convolution and three-dimensional convolution neural network. The algorithm uses sparse sampling to segment the long time sequence video to reduce the amount of redundant information, and integrates non-local convolution into the residual neural network, thus forming a super automatic full variational - L1 algorithm. Experimental results show that the proposed method can significantly improve the efficiency of behavior recognition. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
38. Fabric Wrinkle Objective Evaluation Model with Random Vector Function Link Based on Optimized Artificial Hummingbird Algorithm.
- Author
-
Zhiyu Zhou, Yanjun Hu, Zefei Zhu, and Yaming Wang
- Subjects
VECTOR valued functions ,HUMMINGBIRDS ,OPTIMIZATION algorithms ,BEES algorithm ,ALGORITHMS ,RANDOM forest algorithms ,TEXTILE industry - Abstract
Copyright of Journal of Natural Fibers is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
- Full Text
- View/download PDF
39. Feature detection and description for image matching: from hand-crafted design to deep learning.
- Author
-
Chen, Lin, Rottensteiner, Franz, and Heipke, Christian
- Subjects
IMAGE registration ,DEEP learning ,MACHINE learning ,ALGORITHMS - Abstract
In feature based image matching, distinctive features in images are detected and represented by feature descriptors. Matching is then carried out by assessing the similarity of the descriptors of potentially conjugate points. In this paper, we first shortly discuss the general framework. Then, we review feature detection as well as the determination of affine shape and orientation of local features, before analyzing feature description in more detail. In the feature description review, the general framework of local feature description is presented first. Then, the review discusses the evolution from hand-crafted feature descriptors, e.g. SIFT (Scale Invariant Feature Transform), to machine learning and deep learning based descriptors. The machine learning models, the training loss and the respective training data of learning-based algorithms are looked at in more detail; subsequently the various advantages and challenges of the different approaches are discussed. Finally, we present and assess some current research directions before concluding the paper. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
40. Optimization method of electronic control parameters of antenna array for null controlling in specific regions and sidelobe suppression.
- Author
-
Tang, Yi, Liu, Shutian, Gao, Renjing, and Alibakhshikenari, Mohammad
- Subjects
ELECTRONIC control ,ANTENNA arrays ,ALGORITHMS - Abstract
This paper presents a gradient-based optimisation method of antenna array for null controlling in specific regions and sidelobe suppression. The optimisation problem is formulated as optimising the electronic control parameters (excitation amplitude and phase) of the array to achieve that the maximum value of the peak sidelobe levels (PSLLs) is minimised and the depths of the nulls in specific regions are not greater than a threshold. The Kreisselmeier – Steinhauser (KS) function is used to describe the maximum value of the PSLLs, in this way, the optimisation problem becomes differentiable and can be solved efficiently by gradient-based algorithm. The sensitivities of the objective with respect to the design variables are analytically derived. Typical numerical examples and detailed evaluations are provided to validate the effectiveness of the proposed method. The results show that the null controlling in the predefined specific single, single-wide, dual, multiple, and annular regions is realised, and the PSLL suppression is performed comparing to the uniform planar arrays. In the 28 GHz base station transmitting antenna-array example, the proposed method effectively suppresses the PSLL and greatly saves the calculation time while maintaining the various specific null regions controlling. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
41. A review of deep learning-based image style transfer research.
- Author
-
Li, Hong-an, Wang, Lanye, and Liu, Jun
- Subjects
- *
ARTIFICIAL intelligence , *ARTISTIC style , *TRANSFER of training , *COMPARATIVE studies , *ALGORITHMS , *DEEP learning - Abstract
Image style transfer is a technique that applies artistic styles to natural images while maintaining their original content structures. This technology has a broad spectrum of applications in the stylization of images, comics, and videos, and has emerged as a significant area of research within the field of artificial intelligence. This paper seeks to advance research on deep learning-based image style transfer by summarizing and discussing the principal methods and illustrative outcomes within this domain. It commences with a review of traditional image style transfer algorithms, analyzing their strengths and limitations. The paper then delves into deep learning-based style transfer algorithms, classifying them into image optimization-based and model optimization-based approaches based on the efficiency of transfer. Through an analysis of the current state of image style transfer research, the paper outlines the developmental trajectory and recent milestones in the field. It evaluates the merits and demerits of various methods, addressing current issues such as suboptimal image style transfer quality, model specificity, and the need for enhanced semantic depth. Via comparative analysis, the paper proposes enhancement strategies and suggests future research directions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
42. Analysis of a GIX/M/1 queue with two-stage vacation policy using shift operator method.
- Author
-
Liu, Yufei, Ye, Qingqing, and Yan, Junnai
- Subjects
- *
DIFFERENCE equations , *VACATIONS , *CONSUMERS , *ALGORITHMS - Abstract
In this paper, we investigate a GI X /M/1 queue with the two-stage vacation policy. The system will first enter a working vacation once the system becomes empty in the normal busy period, during which the service rate will be switched to a lower rate. After this working vacation, if the system is nonempty, the service rate will be switched to the normal rate immediately; otherwise, the system will enter multiple vacations during which the service rate reduces to zero until the system is nonempty after one vacation and a new normal busy period starts. The distinguishing feature of this paper is the use of a general algorithm for solving the difference equation based on the right shift operator method to obtain the queue length distribution at pre-arrival time and arbitrary time. Moreover, the sojourn time of arbitrary customer is analyzed. Finally, several typical numerical examples are provided to validate our computational algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
43. Combined peak price tracking strategies for online portfolio selection based on the meta-algorithm.
- Author
-
Zhang, Yong, Lin, Hong, Li, Jiahao, and Yang, Xingyu
- Subjects
MACHINE learning ,PRICES ,ALGORITHMS ,STOCKS (Finance) ,FORECASTING - Abstract
Machine learning algorithms have been widely used to establish online portfolio selection strategies. Meta-algorithm, one of the machine learning algorithms, has the advantage of combining different base expert algorithm, which can greatly reduce the risk of choosing wrong experts, especially in the case of the base expert algorithm being very sensitive to the expert selection. In this paper, we investigate the online portfolio selection problem using Online Gradient Update (OGU) and Online Newton Update (ONU) meta-algorithms to combine expert advice for price prediction, in order to avoid the prediction bias caused by using a single expert that uses a fixed parameter. In addition, we theoretically analyze the price prediction algorithms' regret bounds, which can guarantee that the prediction algorithms perform as well as the optimal combined prediction algorithm in hindsight. More importantly, we establish an online portfolio optimization model based on the price estimator, and obtain the portfolio update formula via Lagrange method. Finally, extensive numerical experiments are conducted to test the performance of the proposed strategies in several real-world stock markets. The empirical results show that our strategies are competitive and efficient in the diverse financial environment. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
44. Adaptive prescribed-time sliding mode control of nonlinear systems with unknown dynamics.
- Author
-
Guo, Ge and Zhang, Qian
- Subjects
ADAPTIVE control systems ,NONLINEAR systems ,SYSTEM dynamics ,SLIDING mode control ,ALGORITHMS - Abstract
One of the main difficulties for application of sliding mode control is the presence of chattering. It is a well known fact that the amplitude of chattering is proportional to the magnitude of discontinuous control. The problem can be alleviated by making the magnitude as small as possible while still ensuring the existence of the sliding mode. In this paper, a novel predefined-time single layer adaptive scheme based on equivalent concept with a relaxed assumption about unknown dynamics is proposed for dynamically tuning the gain associated with the control magnitude, and applying this scheme in sliding mode control algorithms enables decreasing the control action magnitude to the minimum possible value remaining the characteristic of finite-time convergence. Simulation results are shown to verify the effectiveness of the designed scheme. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
45. Robust sliding-mode observer for unbounded state nonlinear systems.
- Author
-
Mobarakeh, Amir Norouzi, Ataei, Mohammad, and Ekramian, Mohsen
- Subjects
NONLINEAR systems ,INDUSTRIALISM ,ALGORITHMS - Abstract
Designing a full-state observer for nonlinear systems has always been accompanied by challenges and restrictive constraints. Mainly, applying a state observer in nonlinear systems with non-minimum phase characteristics is more challenging when the limiting constraints are not satisfied due to diverging internal dynamics. In this paper, a robust sliding-mode observer approach has been successfully employed to estimate the states of nonlinear systems with unbounded and diverging dynamics. The design principles of this observer are based on applying a classifying algorithm in single-input single-output and multiple-input multiple-output nonlinear systems. It is noteworthy that this observer is highly robust against disturbance, uncertainty and measurement noise, and its conditions are less conservative compared to previous nonlinear sliding-mode observers. One novel feature of the proposed observer is that while the system's state gets unbounded and diverged in fault-occurring scenarios or critical circumstances, this observer retains accuracy. The efficiency of the proposed observer is verified in the simulation results for two nonlinear industrial systems, including a hydro-turbine power generation plant and a continuous stirred tank reactor. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
46. Extended observer form with vector fields.
- Author
-
Mullari, Tanel, Kotta, Ülle, Kaldmäe, Arvo, Kaparin, Vadim, and Simha, Ashutosh
- Subjects
VECTOR fields ,DISCRETE-time systems ,NONLINEAR systems ,ALGORITHMS - Abstract
This paper addresses the problem of transforming a single-input single-output discrete-time system into the extended observer form which comprises a linear observable component and a nonlinear injection term depending on the input, output and their forward shifts up to a finite order. The necessary and sufficient conditions for the existence of the extended observer form are provided in terms of vector fields. The algorithm is presented to find a parametrised state transformation necessary to transform the system into the extended observer form. The obtained results are applicable also in case of non-reversible systems. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
47. Distributed Nash equilibrium seeking for multi-cluster aggregative games with applications to location control.
- Author
-
Huang, Bomin, Meng, Ziyang, Chen, Fei, and Lan, Weiyao
- Subjects
NASH equilibrium ,NONLINEAR equations ,ALGORITHMS ,GAMES - Abstract
This paper considers a class of distributed aggregative games for first-order and second-order integrator-type multi-cluster systems, respectively. Two Nash equilibrium seeking algorithms are designed based on a distributed aggregation observer which is used to estimate the aggregations of the clusters. The convergence is proved by the input-to-state stable method. Moreover, the algorithms are applied to a class of location control problems, that is, distributed nonlinear placement problems for multi-cluster systems. Finally, some simulations are presented to illustrate the effectiveness of the designed algorithms. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. Subpixel water area mapping based on spatial information processing at superpixel scale for multispectral imagery.
- Author
-
Wang, Peng, Yan, Ang, Chen, Yiming, Liu, Yuzhou, Xu, Gang, Wang, Yunge, and Liu, Wenjian
- Subjects
RANDOM walks ,INFORMATION processing ,INTERPOLATION ,ALGORITHMS ,MULTISPECTRAL imaging - Abstract
Subpixel water area mapping based on spatial information processing at superpixel scale (SISS) for multispectral imagery is proposed in this paper. In SISS, the superpixels with irregular shape are first obtained by segmenting the first principal component of the improved imagery which is improved from the the original coarse multispectral imagery by using bicubic interpolation; The random walk algorithm is then introduced to calculate these superpixels to obtain the spatial information. Finally, according to this spatial information, the label of the water area or the non-water area is assigned to each subpixel by the class allocation method, producing the final mapping result. The experimental results on two datasets show that the proposed method can achieve the best performance in both visual effects and quantitative indicators. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. Synthesis of nonuniform linear antenna arrays using a hybrid optimization algorithm.
- Author
-
Guo, Hua, Liang, Ying, Mi, Qiming, Song, Peng, Zhang, Lijian, and Han, Yongyong
- Subjects
- *
LINEAR antenna arrays , *OPTIMIZATION algorithms , *ANTENNA arrays , *ALGORITHMS - Abstract
A hybrid algorithm is introduced to synthesize the nonuniform symmetric linear antenna arrays in this paper. The array element positions and excitation coefficients of the antenna arrays are optimized by using Gray Wolf Algorithm (GWO) and Convex Optimization Algorithm (CO). In order to further reduce the sidelobe level, the linear antenna array is divided into several subarrays under the constraints of element number, aperture size and minimum adjacent element spacing. Array element positions, excitation coefficients of each subarray and the element number of each subarray are optimized simultaneously. Finally, the optimization results are compared with the results obtained by other literatures. It is obviously found that the method proposed in this paper can obtain lower sidelobe level under the same conditions. So, the effectiveness and feasibility of the algorithm proposed in this paper is proved. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. Experimental validation of an efficient strategy for FE model updating and damage identification in tubular structures.
- Author
-
Ghannadi, Parsa, Kourehli, Seyed Sina, and Nguyen, Andy
- Subjects
- *
GREY Wolf Optimizer algorithm , *ALGORITHMS - Abstract
Early identification of damages in tubular structures is crucial for their long-term safety and functionality, as they are essential in various modern life applications. Experimental and numerical modal data may slightly differ due to unknown structural characteristics and uncertainties, which are typically addressed using finite element (FE) model updating procedures. Instead of using the Euler-Bernoulli beam element, this paper utilises the semi-rigidly connected frame element (S-RCFE). By incorporating extra design parameters, such as the end fixity factor of all connections, the S-RCFE offers a unique opportunity to establish a strong agreement between experimental and numerical models through an optimisation-based FE model updating procedure. A well-calibrated FE model represents the actual behaviour of the structure and leads to achieving accurate results in the damage detection step. This paper employs the improved grey wolf optimiser (IGWO) and weIghted meaN oF vectOrs (INFO) to minimise 11 objective functions with adjustable coefficients. The statistical investigations reveal that the IGWO effectively minimised five out of six objective functions, which were defined based on the modified total modal assurance criterion (MTMAC). The rest of the objective functions based on the modal assurance criterion (MAC), natural frequency vector assurance criterion (NFVAC), differences in natural frequencies, and a combination of the MAC and NFVAC could not obtain accurate outcomes for the model updating problem. The statistical comparison indicates that the INFO algorithm is unreliable for the FE model updating despite achieving at least one successful result in ten independent runs. The INFO algorithm and the IGWO algorithm demonstrate comparable performance in damage detection. The analysis also shows that the coefficients of MTMAC, alpha and beta, should be adjusted to 0.65 and 1, respectively, to achieve the most accurate damage detection result. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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