scholarly journals Direction-Based Hybrid Strategy Combining Pushing and Hitting for Fast Object Singulation

2021 ◽  
Vol 11 (16) ◽  
pp. 7327
Author(s):  
Muhammad Umair Ahmad Khan ◽  
Sanghwa Kim ◽  
Ji Yeong Lee ◽  
Byung-Ju Yi

This paper presents a hybrid singulation strategy for fast object singulation in a cluttered environment. Recent techniques related to object singulation in clutter have employed various kinds of pushing techniques and in some cases have also used hitting techniques. However, these techniques have not addressed the issue related to the direction of pushing and hitting which is vital for fast object singulation. Finding the appropriate direction of hitting and pushing helps in singulating objects quickly in a cluttered environment. This paper proposes the desired direction for pushing and hitting, combined with a hybrid strategy, that results in fast object singulation in a cluttered environment. The number of times of pushing and hitting in terms of time is chosen as the measure of performance. We employ multiple circular disks as the test example and carry out diverse experiments to corroborate the usefulness of the proposed object singulation algorithm. This approach is able to singulate objects quickly in complex formations. In this paper, we have combined both pushing and hitting and also proposed the direction of hitting and pushing in order to singulate objects in clutter quickly.

Author(s):  
Linda Cundy

Working online during lockdown, psychotherapists have glimpsed inside their clients' homes and sometimes we see a cluttered environment. This article addresses the difficulty experienced by many people of parting with objects, proposing that we identify with our possessions and invest them with feelings in line with our own experiences.


Author(s):  
Joyjit Dhar ◽  
Ram Pratap Sinha

The present study extends the portfolio evaluation framework provided by Sharpe (1964) and Treynor (1965) by including the parameter of market timing with the help of a non-parametric framework. Data envelopment analysis has been used in the present exercise to evaluate the performance 79 mutual funds schemes operating in India for three different phases using two different models. Estimation of technical efficiency on the basis of both the models suggests that period 2 performance is substantially divergent from period 1 and 3. Also, higher moments framework gives a better measure of performance as it accounts not only the standard risk measure but also for skewness and kurtosis characteristics of returns.


2020 ◽  
Author(s):  
Fang Li ◽  
Muhammad "Tuan" Amith ◽  
Grace Xiong ◽  
Jingcheng Du ◽  
Yang Xiang ◽  
...  

BACKGROUND Alzheimer’s Disease (AD) is a devastating neurodegenerative disease, of which the pathophysiology is insufficiently understood, and the curative drugs are long-awaited to be developed. Computational drug repurposing introduces a promising complementary strategy of drug discovery, which benefits from an accelerated development process and decreased failure rate. However, generating new hypotheses in AD drug repurposing requires multi-dimensional and multi-disciplinary data integration and connection, posing a great challenge in the era of big data. By integrating data with computable semantics, ontologies could infer unknown relationships through automated reasoning and fulfill an essential role in supporting computational drug repurposing. OBJECTIVE The study aimed to systematically design a robust Drug Repurposing-Oriented Alzheimer’s Disease Ontology (DROADO), which could model fundamental elements and their relationships involved in AD drug repurposing and integrate their up-to-date research advance comprehensively. METHODS We devised a core knowledge model of computational AD drug repurposing, based on both pre-genomic and post-genomic research paradigms. The model centered on the possible AD pathophysiology and abstracted the essential elements and their relationships. We adopted a hybrid strategy to populate the ontology (classes and properties), including importing from well-curated databases, extracting from high-quality papers and reusing the existing ontologies. We also leveraged n-ary relations and nanopublication graphs to enrich the object relations, making the knowledge stored in the ontology more powerful in supporting computational processing. The initially built ontology was evaluated by a semiotic-driven and web-based tool Ontokeeper. RESULTS The current version of DROADO was composed of 1,021 classes, 23 object properties and 3,207 axioms, depicting a fundamental network related to computational neuroscience concepts and relationships. Assessment using semiotic evaluation metrics by OntoKeeper indicated sufficient preliminary quality (semantics, usefulness and community-consensus) of the ontology. CONCLUSIONS As an in-depth knowledge base, DROADO would be promising in enabling computational algorithms to realize supervised mining from multi-source data, and ultimately, facilitating the discovery of novel AD drug targets and the realization of AD drug repurposing.


Author(s):  
Mats Alvesson ◽  
Yiannis Gabriel ◽  
Roland Paulsen

This book argues that we are currently witnessing not merely a decline in the quality of social science research, but a proliferation of meaningless research of no value to society and modest value to its authors—apart from securing employment and promotion. The explosion of published outputs, at least in social science, creates a noisy, cluttered environment which makes meaningful research difficult, as different voices compete to capture the limelight even briefly. Older, but more impressive contributions are easily neglected as the premium is to write and publish, not read and learn. The result is a widespread cynicism among academics on the value of academic research, sometimes including their own. Publishing comes to be seen as a game of hits and misses, devoid of intrinsic meaning and value and of no wider social uses whatsoever. This is what the book views as the rise of nonsense in academic research, which represents a serious social problem. It undermines the very point of social science. This problem is far from ‘academic’. It affects many areas of social and political life entailing extensive waste of resources and inflated student fees as well as costs to taxpayers. The book’s second part offers a range of proposals aimed at restoring meaning at the heart of social science research, and drawing social science back, address the major problems and issues that face our societies.


2021 ◽  
Vol 11 (3) ◽  
pp. 1211
Author(s):  
En-Chih Chang ◽  
Chun-An Cheng ◽  
Rong-Ching Wu

This paper develops a full-bridge DC-AC converter, which uses a robust optimal tracking control strategy to procure a high-quality sine output waveshape even in the presence of unpredictable intermissions. The proposed strategy brings out the advantages of non-singular fast convergent terminal attractor (NFCTA) and chaos particle swarm optimization (CPSO). Compared with a typical TA, the NFCTA affords fast convergence within a limited time to the steady-state situation, and keeps away from the possibility of singularity through its sliding surface design. It is worth noting that once the NFCTA-controlled DC-AC converter encounters drastic changes in internal parameters or the influence of external non-linear loads, the trembling with low-control precision will occur and the aggravation of transient and steady-state performance yields. Although the traditional PSO algorithm has the characteristics of simple implementation and fast convergence, the search process lacks diversity and converges prematurely. So, it is impossible to deviate from the local extreme value, resulting in poor solution quality or search stagnation. Thereby, an improved version of traditional PSO called CPSO is used to discover global optimal NFCTA parameters, which can preclude precocious convergence to local solutions, mitigating the tremor as well as enhancing DC-AC converter performance. By using the proposed stable closed-loop full-bridge DC-AC converter with a hybrid strategy integrating NFCTA and CPSO, low total harmonic distortion (THD) output-voltage and fast dynamic load response are generated under nonlinear rectifier-type load situations and during sudden load changes, respectively. Simulation results are done by the Matlab/Simulink environment, and experimental results of a digital signal processor (DSP) controlled full-bridge DC-AC converter prototype confirm the usefulness of the proposed strategy.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1887
Author(s):  
Viviana Quintero ◽  
Arturo Gonzalez-Quiroga ◽  
Angel Darío Gonzalez-Delgado

The conservation and proper management of natural resources constitute one of the main objectives of the 2030 Agenda for Sustainable Development designed by the Member States of the United Nations. In this work, a hybrid strategy based on process integration is proposed to minimize freshwater consumption while reusing wastewater. As a novelty, the strategy included a heuristic approach for identifying the minimum consumption of freshwater with a preliminary design of the water network, considering the concept of reuse and multiple pollutants. Then, mathematical programming techniques were applied to evaluate the possibilities of regeneration of the source streams through the inclusion of intercept units and establish the optimal design of the network. This strategy was used in the shrimp shell waste process to obtain chitosan, where a minimum freshwater consumption of 277 t/h was identified, with a reuse strategy and an optimal value of US $5.5 million for the design of the water network.


Designs ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 37
Author(s):  
Maxime Vaidis ◽  
Martin J.-D. Otis

Recent population migrations have led to numerous accidents and deaths. Little research has been done to help migrants in their journey. For this reason, a literature review of the latest research conducted in previous years is required to identify new research trends in human-swarm interaction. This article presents a review of techniques that can be used in a robots swarm to find, locate, protect and help migrants in hazardous environment such as militarized zone. The paper presents a swarm interaction taxonomy including a detailed study on the control of swarm with and without interaction. As the interaction mainly occurs in cluttered or crowded environment (with obstacles) the paper discussed the algorithms related to navigation that can be included with an interaction strategy. It focused on comparing algorithms and their advantages and disadvantages.


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