scholarly journals Adaptive switch to sexually dimorphic movements by partner-seeking termites

2018 ◽  
Author(s):  
Nobuaki Mizumoto ◽  
Shigeto Dobata
Keyword(s):  
Random Search ◽  
Search Pattern ◽  
Sexually Dimorphic ◽  
Tandem Running ◽  
Exact Location ◽  
Nest Sites ◽  
Mate Search ◽  
Search Patterns ◽  
Straight Lines ◽  
Search Modes

AbstractWhen searching for targets whose location is not known, animals should benefit by adopting movement patterns that promote random encounters. During mate search, theory predicts that the optimal search pattern depends on the expected distance to potential partners. A key question is whether actual males and females update their mate search patterns to increase encounter probability when conditions change. Here we show that two termite species, Reticulitermes speratus and Coptoterines formosanus, adaptively alternate between sexually monomorphic and dimorphic movements during mate search. After leaving their nests in a synchronized manner, termites begin to search for a mate. The resulting pairs perform tandem runs toward potential nest sites. We found that both sexes moved faster and in straight lines before finding partners, which is known to improve encounter rates when targets have completely unpredictable positions. In stark contrast, when pairs were accidentally separated during tandem running, they showed distinct sexually dimorphic movements, where females paused for long periods while males paused only briefly and moved actively. Data-based simulations demonstrated that such sexually dimorphic movements are advantageous when a mate is located nearby but its exact location is unknown. These results emphasize the importance of biological details to evaluate the efficiency of random search in animals. By extending the concept of mutual search beyond the context of mating, the dimorphic movements between partners represent a remarkable convergence between termites and other animals including humans.Significance StatementHow should females and males move to search for partners whose exact location is unknown? Theory predicts that the answer depends on what they know about where targets can be found, indicating that the question doesn’t make sense until the searching context is clarified. We demonstrated that termites adaptively switch their search modes depending on the potential distance to their partners. When the location of potential mates was completely unpredictable, both sexes moved in straight lines to explore widely. In contrast, when the stray partner was at least nearby, males moved while females paused. Simulations confirmed that these movements increase the rate of successful encounters. The context-dependent switch of search modes is a key to enhance random encounters in animals.

scholarly journals Adaptive switch to sexually dimorphic movements by partner-seeking termites

2019 ◽  
Vol 5 (6) ◽  
pp. eaau6108 ◽  
Author(s):  
Nobuaki Mizumoto ◽  
Shigeto Dobata
Keyword(s):  
Sexually Dimorphic ◽  
Encounter Probability ◽  
Exact Location ◽  
Mate Search ◽  
Search Patterns ◽  
Context Dependent ◽  
Straight Lines ◽  
Search Modes ◽  
Adaptive Switch

How should females and males move to search for partners whose exact location is unknown? Theory predicts that the answer depends on what they know about where targets can be found, raising the question of how actual animals update their mate search patterns to increase encounter probability when conditions change. Here, we show that termites adaptively alternate between sexually monomorphic and dimorphic movements during mate search. When the location of potential mates was completely unpredictable, both sexes moved in straight lines to explore widely. In contrast, when the stray partner was at least nearby, males moved while females paused. Data-based simulations confirmed that these movements increase the rate of successful encounters. The context-dependent switch of search modes is a key to enhance random encounters.

scholarly journals Optimizing mating encounters by sexually dimorphic movements

2017 ◽  
Vol 14 (130) ◽  
pp. 20170086 ◽  
Author(s):  
Nobuaki Mizumoto ◽  
Masato S. Abe ◽  
Shigeto Dobata
Keyword(s):  
Sexual Dimorphism ◽  
Random Search ◽  
Movement Patterns ◽  
Sexually Dimorphic ◽  
Trade Off ◽  
Analytical Approximations ◽  
Mate Search ◽  
Individual Mating ◽  
Monomorphic Population ◽  
Speed And Accuracy

All organisms with sexual reproduction undergo a process of mating, which essentially involves the encounter of two individuals belonging to different sexes. During mate search, both sexes should mutually optimize their encounters, thus raising a question of how they achieve this. Here, we show that a population with sexually dimorphic movement patterns achieves the highest individual mating success under a limited lifespan. Extensive simulations found and analytical approximations corroborated the existence of conditions under which sexual dimorphism in the movement patterns (i.e. how diffusively they move) is advantageous over sexual monomorphism. Mutual searchers with limited lifespans need to balance the speed and accuracy of finding their mates, and dimorphic movements can solve this trade-off. We further demonstrate that the sexual dimorphism can evolve from an initial sexually monomorphic population. Our results emphasize the importance of considering mutual optimization in problems of random search.

HOST FINDING BEHAVIOR OF COELOIDES BRUNNERI (HYMENOPTERA: BRACONIDAE)

1972 ◽  
Vol 104 (8) ◽  
pp. 1235-1250 ◽  
Author(s):  
J. V. Richerson ◽  
John H. Borden
Keyword(s):  
Ponderosa Pine ◽  
Random Search ◽  
Host Finding ◽  
Douglas Fir ◽  
Search Pattern ◽  
Dendroctonus Pseudotsugae ◽  
Straight Path ◽  
Search Patterns ◽  
Plastic Cylinder ◽  
Host Finding Behavior

AbstractThe host-finding search patterns of Coeloides brunneri Viereck, a braconid parasite of Douglas-fir beetle larvae, were studied by visual observations and from tracings of the parasite’s path on a plastic cylinder wrapped around a beetle-infested log on which the parasite was searching. The female parasite locates its host, lying under approximately.6 cm of bark, through four distinct phases of host finding: random search, nonrandom search, oviposition, and nonsearch (resting and cleaning). Random search is characterized by large areas of bark being examined in a relatively straight path. Nonrandom search is a highly intensified examination of a small bark area and numerous turns of greater than 70°. Nonrandom search is initiated only at the end of a bark beetle gallery. Ovipositional probes are the culmination of successful host finding, in which the parasite paralyzes the host and deposits an egg. C. brunneri searched effectively on both Dendroctonus pseudotsugae Hopkins in Douglas-fir and D. ponderosae Hopkins in ponderosa pine, although there was a slightly more efficient search on D. pseudotsugae. The percentage of time spent in each search pattern was identical in 90-minute and 24-hour tests. A stimulus associated with the end of a larval gallery was concluded to be the key stimulus by which the parasite recognizes its host. Amputation experiments showed that the antennae are the principal receptor organs used in host finding. Various experiments and observations produced no evidence that sound or vibrations produced by the host, sound produced by the parasite (sonar), magnetism or odor of the host, or its host tree are used in host finding.

scholarly journals Fast Motion Estimation Algorithm using Hybrid Search Patterns for Video Streaming Application

2017 ◽  
Vol 12 (5) ◽  
pp. 715
Author(s):  
Vani Rajamanickam ◽  
Ushabhanu Nageswaran ◽  
Sangeetha Marikkannan
Keyword(s):  
Motion Estimation ◽  
Motion Vector ◽  
Block Matching ◽  
Search Pattern ◽  
Live Streaming ◽  
Hybrid Search ◽  
Fast Motion Estimation ◽  
Streaming Application ◽  
Diamond Search ◽  
Search Patterns

The objective of the paper is to develop new block matching Motion Estimation (ME) algorithm using hybrid search patterns along the direction of best match. The search efficiency for sequences with fast motions and high resolutions is improved by proposing New Cross Diagonal-Hexagon Search (NCDHS) algorithm which involves a novel multi half-hexagon grid global search pattern and a cross diagonal-hexagon local search pattern. The new search pattern enables the proposed algorithm to perform better search using 9.068 search points on an average, to obtain optimal motion vector with slight improvement in quality. This inturn reduces ME Time upto 50.11%, 47.12%, 32.99% and 43.28% on average when compared to the existing Diamond Search (DS), Hexagon Search (HS), New Cross Hexagon Search (NHEXS) and Enhanced Diamond Search (EDS) algorithms respectively. The novelty of the algorithm is further achieved by applying the algorithm proposed for live streaming application. The NCDHS algorithm is run on two MATLAB sessions on the same computer by establishing the connection using Transmission Control Protocol (TCP) /Internet Protocol (IP) network. The ME Time obtained is 14.5986 seconds for a block size 16x16, is less when compared to existing algorithms and that makes the NCDHS algorithm suitable for real time streaming application.

Can we Train Humans to be Systematic Inspectors?

1998 ◽  
Vol 42 (16) ◽  
pp. 1165-1169 ◽  
Author(s):  
George M. Nickles ◽  
Valerie Sacrez ◽  
Anand K. Gramopadhye
Keyword(s):  
Search Strategy ◽  
Random Search ◽  
Systematic Search ◽  
Search Pattern ◽  
Search Performance ◽  
Inspection Task ◽  
Job Aid

Previous research in inspection has shown that a systematic search strategy is more effective than a random search strategy in looking for defects. Moreover, past studies have shown that training can improve search strategy. The purpose of this study was to determine if a job aid could be used to train inspectors to adopt a systematic search strategy and thereby improve their search performance. The study used a computer simulated inspection task and a job aid, which included a cursor that traced a systematic search pattern over the inspection surface represented by the screen. An experiment was designed wherein sixteen subjects were randomly assigned to two groups, those who received practice and instructions on the use of a systematic search strategy and those who received training on the job aid. The results are analyzed and reported

scholarly journals Identifying visual search patterns in eye gaze data; gaining insights into physician visual workflow

2016 ◽  
Vol 23 (6) ◽  
pp. 1180-1184 ◽  
Author(s):  
Allan Fong ◽  
Daniel J Hoffman ◽  
A Zachary Hettinger ◽  
Rollin J Fairbanks ◽  
Ann M Bisantz
Keyword(s):  
Visual Search ◽  
Eye Tracking ◽  
Health Information ◽  
Information Technologies ◽  
Tracking System ◽  
Specific Area ◽  
Search Pattern ◽  
First Order ◽  
Search Patterns ◽  
Search For Information

Abstract Importance and Objectives As health information technologies become more prevalent in physician workflow, it is increasingly important to understand how physicians are using and interacting with these systems. This includes understanding how physicians search for information presented through health information technology systems. Eye tracking technologies provide a useful technique to understand how physicians visually search for information. However, analyzing eye tracking data can be challenging and is often done by measuring summative metrics, such as total time looking at a specific area and first-order transitions. Methods In this paper, we propose an algorithmic approach to identify different visual search patterns. We demonstrate this approach by identifying common visual search patterns from physicians using a simulated prototype emergency department patient tracking system. Results and Conclusions We evaluate and compare the visual search pattern results to first-order transition results. We discuss the benefits and limitations of this approach and insights from this initial evaluation.

scholarly journals The Search Patterns of Abdominal Imaging Subspecialists for Abdominal Computed Tomography: Toward a Foundational Pattern for New Radiology Residents

2021 ◽  
Vol 11 ◽  
pp. 1
Author(s):  
Mark A. Kliewer ◽  
Michael Hartung ◽  
C. Shawn Green
Keyword(s):  
Computed Tomography ◽  
Eye Gaze ◽  
Correlation Coefficients ◽  
The Body ◽  
Abdominal Imaging ◽  
Search Pattern ◽  
Abdominal Ct ◽  
Sagittal Image ◽  
Search Patterns ◽  
Picture Archiving And Communication

Objectives: The routine search patterns used by subspecialty abdominal imaging experts to inspect the image volumes of abdominal/pelvic computed tomography (CT) have not been well characterized or rendered in practical or teachable terms. The goal of this study is to describe the search patterns used by experienced subspecialty imagers when reading a normal abdominal CT at a modern picture archiving and communication system workstation, and utilize this information to propose guidelines for residents as they learn to interpret CT during training. Material and Methods: Twenty-two academic subspecialists enacted their routine search pattern on a normal contrast-enhanced abdominal/pelvic CT study under standardized display parameters. Readers were told that the scan was normal and then asked to verbalize where their gaze centered and moved through the axial, coronal, and sagittal image stacks, demonstrating eye position with a cursor as needed. A peer coded the reported eye gaze movements and scrilling behavior. Spearman correlation coefficients were calculated between years of professional experience and the numbers of passes through the lung bases, liver, kidneys, and bowel. Results: All readers followed an initial organ-by-organ approach. Larger organs were examined by drilling, while smaller organs by oscillation or scanning. Search elements were classified as drilling, scanning, oscillation, and scrilling (scan drilling); these categories were parsed as necessary. The greatest variability was found in the examination the body wall and bowel/mesentery. Two modes of scrilling were described, and these classified as roaming and zigzagging. The years of experience of the readers did not correlated to number of passes made through the lung bases, liver, kidneys, or bowel. Conclusion: Subspecialty abdominal radiologists negotiate through the image stacks of an abdominal CT study in broadly similar ways. Collation of the approaches suggests a foundational search pattern for new trainees.

scholarly journals Aging and Decisions From Experience: Differences in Information Search and Subsequent Decision Quality

2021 ◽  
Author(s):  
Pete Wegier
Keyword(s):  
Older Adults ◽  
Information Search ◽  
Fluid Intelligence ◽  
Decision Quality ◽  
Search Pattern ◽  
Pattern Selection ◽  
Younger Adults ◽  
Age Related ◽  
Search Patterns ◽  
Affective Feedback

Across a wide variety of choice tasks requiring information to be learned prior to a decision be made, older adults have been found to search for less information than their younger adult counterparts. This dissertation proposed and investigated several potential causes of this age-related decline in the extent of information search: (1) Domain familiarity; (2) Search patterns; (3) Affect; and (4) Risk. The results of four experiments are presented. In each, no significant age-related decline in the extent of information search was found. Despite this, each experiment presents novel findings, adding to our understanding of how information search and subsequent decision quality in choice changes with age. Experiment 1 revealed an age-related shift in search pattern selection during pre-decisional information search. Older adults showed a preference for the use of a comprehensive, infrequent-switch, pattern during search. Experiment 2 demonstrated the significant impact that search patterns can have on decision quality. Search pattern use was strictly enforced and it was found that searching using a piecewise search pattern resulted in a significant improvement in performance, relative to comprehensive search, across both younger and older adult age groups, despite older adults showing declines in their fluid intelligence. Experiment 3 investigated the role of affective feedback on decision quality. When given affect-rich and affect-poor feedback, an interaction of age and affective feedback on decision quality was observed. Younger adults’ performance was greater when they were provided with affect-poor performance feedback compared to affect-rich feedback, but a similar trend was not observed in older adults. Experiment 4 found older adults to be no less efficient in identifying higher value outcomes than younger adults. Overall, this dissertation presents several novel findings in the field of decision-making research. The importance of search pattern selection on decision quality was demonstrated. More critical is the finding that older adults are no less effective in their decisions across a wide array of tasks and manipulations, despite existing stereotypes and evidence of age-related declines in cognitive abilities. Moving forward, the work presented here could be used to guide the future creation of decision aids and new approaches to choice.

scholarly journals Credibilistic fuzzy clustering based on evolutionary method of crazy cats

2021 ◽  
pp. 110-119
Author(s):  
Yevgeniy Bodyanskiy ◽  
Alina Shafronenko ◽  
Iryna Pliss
Keyword(s):  
Evolutionary Algorithms ◽  
Fuzzy Clustering ◽  
High Speed ◽  
Random Search ◽  
Goal Function ◽  
Large Datasets ◽  
Global Extremum ◽  
Mathematical Procedure ◽  
Global Random Search ◽  
Search Modes

The problem of fuzzy clustering of large datasets that are sent for processing in both batch and online modes, based on a credibilistic approach, is considered. To find the global extremum of the credibilistic fuzzy clustering goal function, the modification of the swarm algorithm of crazy cats swarms was introduced, that combined the advantages of evolutionary algorithms and a global random search. It is shown that different search modes are generated by a unified mathematical procedure, some cases of which are known algorithms for both local and global optimizations. The proposed approach is easy to implement and is characterized by the high speed and reliability in problems of multi-extreme fuzzy clustering.

The Efficiency of Different Search Patterns in Electronic Market

2010 ◽  
pp. 55-73
Author(s):  
Theresa Lauraeus-Niinivaara ◽  
Timo Saarinen ◽  
Anne Sunikka ◽  
Anssi Öörni
Keyword(s):  
Information Search ◽  
High Efficiency ◽  
Search Costs ◽  
Pattern Search ◽  
Consumer Information ◽  
Search Pattern ◽  
Electronic Market ◽  
Iterative Search ◽  
Factors Affecting ◽  
Search Patterns

Electronic markets are expected to facilitate consumer information search and product comparison to the extent that consumers are able to accumulate nearly perfect information. The authors present an analysis of search patterns based on a laboratory experiment on product search processes. They identified three types of search patterns in the experiment: sequential, agent search, and iterative search. They studied the factors affecting the choice and the outcome of agent search pattern compared to the other search patterns. The results show that the employed search pattern has an impact on search cost and the efficiency of search measured with purchase price and the time used for searching. Agent search seems to combine low search costs with high efficiency. Sequential search still emerged as the dominant search pattern even though it leads to the most expensive purchase. Iterative search pattern search pattern.

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