Detection of small target in sea clutter via multiscale directional Lyapunov exponents

Sensor Review ◽  
2019 ◽  
Vol 39 (6) ◽  
pp. 752-762
Author(s):  
Rui Wang ◽  
Xiangyang Li ◽  
Hongguang Ma ◽  
Hui Zhang
Keyword(s):  
State Space ◽  
Lyapunov Exponents ◽  
Design Methodology ◽  
Radar Data ◽  
Nonstationary Time Series ◽  
New Method ◽  
Small Target ◽  
Sea Clutter ◽  
Eigenvalues And Eigenvectors ◽  
Content Type

Purpose This study aims to provide a new method of multiscale directional Lyapunov exponents (MSDLE) calculated based on the state space reconstruction for the nonstationary time series, which can be applied to detect the small target covered by sea clutter. Design/methodology/approach Reconstructed state space is divided into non-overlapping submatrices whose columns are equal to a predetermined scale. The authors compute eigenvalues and eigenvectors of the covariance matrix of each submatrix and extract the principal components σip and their corresponding eigenvectors. Then, the angles ψip of eigenvectors between two successive submatrices were calculated. The curves of (σip, ψip) reflect the nonlinear dynamics both in kinetic and directional and form a spectrum with multiscale. The fluctuations of (σip, ψip), which are sensitive to the differences of backscatter between sea wave and target, are taken out as the features for the target detection. Findings The proposed method can reflect the local dynamics of sea clutter and the small target within sea clutter is easily detected. The test on the ice multiparameter imaging X-ban radar data and the comparison to K distribution based method illustrate the effectiveness of the proposed method. Originality/value The detection of a small target in sea clutter is a compelling issue, as the conventional statistical models cannot well describe the sea clutter on a larger timescale, and the methods based on statistics usually require the stationary sea clutter. It has been proven that sea clutter is nonlinear, nonstationary or cyclostationary and chaotic. The new method of MSDLE proposed in the paper can effectively and efficiently detect the small target covered by sea clutter, which can be also introduced and applied to military, aerospace and maritime fields.

Lubricant compatibility of FKM seals in synthetic oils

2019 ◽  
Vol 72 (5) ◽  
pp. 557-565
Author(s):  
Dilek Bulut ◽  
Tatjana Krups ◽  
Gerhard Poll ◽  
Ulrich Giese
Keyword(s):  
Polyethylene Glycol ◽  
Design Methodology ◽  
Elevated Temperatures ◽  
Failure Mechanisms ◽  
Standard Test ◽  
New Method ◽  
Static Tests ◽  
Content Type ◽  
Lip Seals ◽  
First Results

Purpose Elastomer seals are used in many applications. They are exposed to lubricants and additives at elevated temperatures, as well as mechanical stresses. They can only provide good sealing function when they have resistance to those factors. There are many elastomer-lubricant compatibility tests based on DIN ISO 1817 in industry. However, they are insufficient and costly. Correlations between the tests and the applications are inadequate. The purpose of this study is investigating lubricant compatibility of fluoroelastomers (FKM) seals in polyethylene-glycol (PG)- and polyalphaolefin (PAO)- based synthetic oils and developing a methodology to predict seal service life. Design/methodology/approach A new compatibility test which is more sufficient in terms of time and cost was developed and compared with a standard test, currently used in industry. Compatibility of FKM radial lip seals with PG- and PAO-based synthetic oils with different additives was investigated chemically and dynamically. Failure mechanisms were examined. Findings The new method and the Freudenberg Flender Test FB 73 11 008 showed similar results concerning damages and similar tendencies regarding wear. The additive imidazole derivative was the most critical. Static tests give indications of possible chemically active additives, but alone they are insufficient to simulate the dynamic applications. Originality/value The paper describes a new method to investigate elastomer-lubricant compatibility and gives first results with a variety of lubricants.

Performance assessment of the complex repairable system with n-identical units under (k-out-of-n: G) scheme and copula linguistic repair approach

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
V. V. Singh ◽  
Abubakkar Idris Mohhammad ◽  
Kabiru Hamisu Ibrahim ◽  
Ibrahim Yusuf
Keyword(s):  
Complex System ◽  
Design Methodology ◽  
New Method ◽  
Social Implications ◽  
Repairable System ◽  
Variable Technique ◽  
Content Type ◽  
Different Types ◽  
Theoretical Assessment ◽  
Practical Implications

PurposeThis paper analyzed a complex system consisting n-identical units under a k-out-of-n: G; configuration via a new method which has not been studied by previous researchers. The computed results are more supportable for repairable system performability analysis.Design/methodology/approachIn this paper, the authors have analyzed a complex system consisting n-identical units under a k-out-of-n: G; configuration via a new method which has not been studied by previous researchers. The supplementary variable technique has employed for analyzing the performance of the system.FindingsReliability measures have been computed for different types of configuration. It generalized the results for purely series and purely parallel configurations.Research limitations/implicationsThis research may be beneficial for industrial system performances whereas a k-out-of-n-type configuration exists.Practical implicationsNot sure as it is a theoretical assessment.Social implicationsThis research may not have social implications.Originality/valueThis work is the sole work of authors that have not been communicated to any other journal before.

Wildcards – natural and artificial: the combination of a panel of experts and Fuzzy TOPSIS

foresight ◽  
2017 ◽  
Vol 19 (1) ◽  
pp. 15-30 ◽  
Author(s):  
Mohsen Mohammadi ◽  
Mohammad Rahim Eivazi ◽  
Jafar Sajjadi
Keyword(s):  
Design Methodology ◽  
Fuzzy Topsis ◽  
New Method ◽  
Weak Signals ◽  
Content Type ◽  
Participatory Foresight ◽  
The Future ◽  
Similar Character ◽  
Topsis Model

Purpose The purpose of this paper is threefold: to classify wildcards into three particular types sharing similar characteristics; use the Fuzzy TOPSIS as a new method in foresight to turn qualitative ideas into quantitative ones; and apply a combination of Fuzzy TOPSIS and a panel of experts to prioritize weak signals. Design/methodology/approach In this paper, the authors classify wildcards into three particular types which share similar character: natural wildcards, artificial wildcards (Degree 1) and artificial wildcards (Degree 2). Wildcards point to unexpected and surprising events including important results that can form watershed in the development of a specific trend. In addition, the authors present a Fuzzy TOPSIS model which can be used in various cases to prioritize a number of weak signals and put them in order, so that the most important ones are likely to yield the wildcard in the future Findings The authors presented a classification of wildcards with the same characteristics being natural wildcards, artificial wildcards (Degree 1) and artificial wildcards (Degree 2). The authors also prioritized the weak signals to deal with the most important ones and take appropriate action in advance so as to minimize possible damages and maximize the benefits of potential wildcards in an uncertain environment. Originality/value In this paper, the authors report on the prioritizing of weak signals by applying Fuzzy TOPSIS and classify wildcards. This is significant because, by identifying the most important weak signals, appropriate actions can be taken in the future if necessary. The paper should be of interest to readers in the area of participatory foresight.

A new method for process control based on goodness of fit tests

2015 ◽  
Vol 32 (2) ◽  
pp. 132-143
Author(s):  
Mohammad Saleh Owlia ◽  
Mohammad Saber Fallah Nezhad ◽  
Mohesn Sheikh Sajadieh
Keyword(s):  
Process Control ◽  
Design Methodology ◽  
Goodness Of Fit ◽  
New Method ◽  
Content Type ◽  
Goodness Of Fit Tests ◽  
Kolmogorov Smirnov ◽  
Shift Detection ◽  
The Subject ◽  
Smirnov Test

Purpose – The purpose of this paper is to propose a new method based on goodness of fit tests for shift detection problems. Design/methodology/approach – In this method, although the distribution of gathered data from the process is the subject of control, but any out-of-control signal could also be generalized to the overall state of the process including the parameters of the distribution. Findings – Results of simulation study denote that among goodness of fit tests, the χ2 test has a better performance than the Kolmogorov-Smirnov test in detecting shifts of process. Also comparison of proposed method with traditional methods denotes that, proposed method generally has smaller probabilities of first and second type errors. Originality/value – To the best of author’s knowledge, no attention has previously been paid to application of goodness of fit tests in process control.

To explore new avenues: experiential testimonio research

2014 ◽  
Vol 52 (4) ◽  
pp. 794-812 ◽  
Author(s):  
Marie-Noelle Albert ◽  
Marie-Michele Couture
Keyword(s):  
Qualitative Research ◽  
Research Method ◽  
Design Methodology ◽  
Scientific Research ◽  
Management Science ◽  
New Method ◽  
Qualitative Research Method ◽  
Content Type ◽  
Empirical Material

Purpose – The purpose of this paper is to propose a qualitative research method for which the empirical material is drawn from the experience of a practitioner-researcher. Design/methodology/approach – First, a review of other autobiographical methods is made to show that the proposed method offers something different. Subsequently, it briefly outlines the epistemological and theoretical anchors that guided the development of the proposed method. Then it follows the path and the peculiarities of this method. And finally a few guidelines are presented for the legitimization of the knowledge generated, illustrated by an example. Findings – The proposed method is aimed at experienced practitioners who are involved in a process of scientific research. Ideally, it is carried out with a co-searcher. Originality/value – A new method of qualitative research to explore new avenues in management science.

“I played a song with the help of a magic banana”: assessing short-term making events

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jessie Nixon ◽  
Erica Halverson ◽  
Andy Stoiber ◽  
Andy Garbacz
Keyword(s):  
Design Methodology ◽  
Learning Experiences ◽  
Assessment Method ◽  
New Method ◽  
Individual Experience ◽  
Natural Setting ◽  
Short Term ◽  
Content Type ◽  
Written Responses ◽  
Learner Responses

Purpose The purpose of this study is to understand how learners describe their experiences with short-term, introductory maker experiences and to test a method for assessing learners’ experiences authentic to short-term learning. Design/methodology/approach The authors collected written responses from participants at a two-day event, STEM Center Learning Days. Through an analysis of 707 unique instances of learner responses to participation in drop-in maker activities, they examined how participants describe their short-term learning experiences. Findings The authors found that although some activities appear to onlookers to create passive experiences for learners, these seemingly passive moments have a significant impact on learners. In addition, some learners described themselves as working in tandem with tools to make something work and other learners viewed the tools as working autonomously. They found that the assessment method allowed them to gain an understanding of how learners describe their experiences offering important implications for understanding short-term learning events. Originality/value The findings provide researchers studying short-term learning in its natural setting a new method to understand how learners make sense of their individual experience. Further, designers of short-term learning experiences may gain insights into their unique activities and indications of where additional guidance and scaffolds will improve small learning moments.

Automatic disassembly navigation for accurate virtual assembly path planning

2014 ◽  
Vol 34 (3) ◽  
pp. 244-254 ◽  
Author(s):  
Wanbin Pan ◽  
Yigang Wang ◽  
Peng Du
Keyword(s):  
Virtual Reality ◽  
Path Planning ◽  
Virtual Environment ◽  
Design Methodology ◽  
Virtual Assembly ◽  
New Method ◽  
Virtual Reality System ◽  
New Approach ◽  
Content Type ◽  
Human Interactions

Purpose – The purpose of this paper is to develop an automatic disassembly navigation approach for human interactions in the virtual environment to achieve accurate and effective virtual assembly path planning (VAPP). Design/methodology/approach – First, to avoid the error-prone human interactions, a constraint-based disassembly method is presented. Second, to automatically provide the next operable part(s), a disassembly navigation mechanism is adopted. Finally, the accurate assembly path planning can be obtained effectively and automatically by inversing the ordered accurate disassembly paths, which are obtained interactively in the virtual environment aided with the disassembly navigation matrix. Findings – The applications present that our approach can effectively avoid the error-prone interactive results and generate accurate and effective VAPP. Research limitations/implications – There are several works that could be conducted to make our approach more general in the future: to further study the basic disassembly direction deducing rules to make the process of determining disassembly direction totally automatic, to consider the hierarchy of the parts in virtual reality system and to consider the space for assembly/disassembly tools or operators. Originality/value – The approach has the following characteristics: a new approach to avoid the error-prone human interactions for accurate assembly path planning obtaining, a new constraint deducing method for determining the disassembly semantics automatically or semi-automatically is put forward and a new method for automatically identifying operable parts in VAPP is set forward.

Identifying the impact of incremental innovations on customer satisfaction using a fusion method between importance-performance analysis and Kano model

2013 ◽  
Vol 31 (1) ◽  
pp. 32-52 ◽  
Author(s):  
Gerson Tontini ◽  
Jaime Dagostin Picolo
Keyword(s):  
Performance Analysis ◽  
Customer Satisfaction ◽  
Design Methodology ◽  
Gap Analysis ◽  
New Method ◽  
Kano Model ◽  
Attribute Importance ◽  
Content Type ◽  
Customer Dissatisfaction ◽  
The Impact

Purpose – This paper aims to present and compare a new method, improvement gap analysis (IGA), with two different versions of importance-performance analysis (IPA) – original IPA and diagonal IPA – focusing on how each method evaluates the possible impact of incremental innovations on customer satisfaction. Design/methodology/approach – Two studies were carried out, one with users of mobile phones and another with users of a fitness centre. Mobile phone users answered questions about 24 attributes, of which six were incremental innovations at the time of the research. Users of the fitness centre answered questions about 16 attributes, of which three were incremental innovations. Findings – Both case studies show that diagonal IPA overcomes two limitations of original IPA, in terms of IPA's failure to address: the high correlation between stated importance and customer satisfaction and the non-linear relationship between attribute performance and customers’ satisfaction. However, diagonal IPA is unable to identify the possible impact of incremental innovations on customer satisfaction. Thus, IGA is formulated to overcome both the problems with original IPA and the limitation of diagonal IPA. Research limitations/implications – The new method, IGA, uses expected customer dissatisfaction as a measure of attribute relevance. Its relationship with other methods used to evaluate attribute importance should be studied in the future. Originality/value – The paper presents a new method (IGA) that is able to overcome problems of original and diagonal IPA methods and is also able to identify the possible impact of incremental innovations on customer satisfaction.

scholarly journals Creating institutional disruption: an alternative method to study institutions

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Devon Gidley
Keyword(s):  
Design Methodology ◽  
Social Institutions ◽  
New Method ◽  
Institutional Work ◽  
Field Methods ◽  
Content Type ◽  
Alternative Method ◽  
Research Questions ◽  
Institutional Features ◽  
Institutional Actors

PurposeThis paper develops a new method to study institutions based on institutional work theory. Institutional disruption is intentionally utilized to explore the taken-for-granted foundations of social institutions. The paper outlines the method and considerations.Design/methodology/approachTaking inspiration from ethnomethodological breaches, the paper outlines the steps in the new method called researcher initiated institutional disruption (RIID). The four steps are identifying the institution, identifying the institutional actors, selecting the disruption type and disrupting the institution to gather data (action and reaction). RIID utilizes three types of institutional disruption: undermining assumptions and beliefs, resistance and issue raising.FindingsThe new method complements traditional field methods, such as observation, by showing how a researcher can deliberately make taken-for-granted institutional features visible. The paper finds that RIID offers the opportunity to gather different data, but it is not appropriate for every study and carries potential consequences in the field.Originality/valueThis paper contributes to the literature by outlining an innovative use of theory as method. The approach has not previously been detailed and offers the potential to access previously inaccessible research questions, data and theoretical insights.

scholarly journals Measuring competitive intensity in sports leagues

2020 ◽  
Vol 10 (5) ◽  
pp. 599-620
Author(s):  
Fabio Wagner ◽  
Holger Preuss ◽  
Thomas Könecke
Keyword(s):  
Design Methodology ◽  
Round Robin ◽  
New Method ◽  
Competitive Intensity ◽  
Content Type ◽  
The Past ◽  
Sports Leagues ◽  
The Individual ◽  
Practical Implications

PurposeFor managers of sports leagues, it is crucial to produce an attractive competition. For that to happen, it is vital to consider that leagues frequently have more sub-competitions than “just” the championship. In European top football leagues, for instance, four sub-competitions are common (championship, qualification for Champions- or Europa League, avoiding relegation). This paper introduces a new method for measuring competitive intensity (CI) in round-robin sports leagues considering all relevant sub-competitions and applies it to Germany's Bundesliga.Design/methodology/approachThe newly developed model calculates a CI-Index for each sub-competition and the league as a whole. The application to the Bundesliga analyzes its viability and the development of the league's CI over the past 22 seasons.FindingsThe newly introduced CI-Indices prove to be a viable tool for evaluating a league's competitive intensity. The application to the Bundesliga shows that the seasonal CI dropped after 2009/10, which can mainly be attributed to a decline in the championship's CI.Practical implicationsThe results show that it is important to facilitate a high CI in each of Bundesliga's four sub-competitions. Efforts have to be made to ensure that especially the Europa League remains as attractive as possible for the participating teams and their fans because this sub-competition constantly makes the greatest contribution to the seasonal CI.Originality/valueThe new method measures competitive intensity by quantifying the different sub-competitions and their contribution to the seasonal CI. This allows the organizers of sports leagues to assess the intensity of the individual sub-competitions as well as the league as a whole.

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