Three Generations of Automatically Designed Robots

2001 ◽  
Vol 7 (3) ◽  
pp. 215-223 ◽  
Author(s):  
Jordan B. Pollack ◽  
Hod Lipson ◽  
Gregory Hornby ◽  
Pablo Funes
Keyword(s):  
General Purpose ◽  
Modular Robots ◽  
Automatic Design ◽  
Short Term ◽  
Electromechanical Systems ◽  
Three Generations ◽  
Repetitive Tasks ◽  
Alternative Approach

The difficulties associated with designing, building, and controlling robots have led their development to a stasis: Applications are limited mostly to repetitive tasks with predefined behavior. Over the last few years we have been trying to address this challenge through an alternative approach: Rather than trying to control an existing machine or create a general-purpose robot, we propose that both the morphology and the controller should evolve at the same time. This process can lead to the automatic design of special-purpose mechanisms and controllers for specific short-term objectives. Here we provide a brief review of three generations of our recent research, which underlies the robots shown on the cover of this issue: Automatically designed static structures, automatically designed and manufactured dynamic electromechanical systems, and modular robots automatically designed through a generative DNA-like encoding.

scholarly journals The challenges facing legumes in a dryland environment - a consultant's view

2003 ◽  
Vol 11 ◽  
pp. 7-12
Author(s):  
C.D. Brown ◽  
R.B. Green
Keyword(s):  
Farming Systems ◽  
General Purpose ◽  
Government Support ◽  
Perennial Species ◽  
Short Term ◽  
Diverse Range ◽  
Feed Quality ◽  
Dryland Farming ◽  
High Feed ◽  
Stocking Rates

The dryland regions of New Zealand suffer from summer moisture deficits in the majority of years. These dryland regions have been developed along the same basis as other farming regions, with increasing fertiliser usage leading to more subdivision and higher stocking rates. Given the exposure to droughts, the production per head of these regions has been extremely variable. Historically, dryland farming systems have been based around breeding ewe systems with all lambs finished if the season allowed. Since the removal of all Government support during adverse events, in the early 1990s, farm systems have become considerably more diverse. Irrigation areas have doubled between 1985 and 1999 to approximately 500 000 hectares. Both sub clover and lucerne have been used extensively in dryland areas, but the main legume is still white clover. Farmers recognise the significant limitations in the ability of white clovers to cope with summer droughts, but have not been able to efficiently utilise other legumes, which require unique management to perform. There are a number of reasons for this. Looking forward, the five key roles that legumes have in dryland farming systems are, to persist within a general purpose pasture, to produce nitrogen, to improve summer feed quality, to improve year round quality feed through specialist crops and pastures and to provide specialist composite feeds (i.e. condensed tannins). With the increased diversity in farming systems, growers require a more diverse range of legumes from perennial species to annuals that will fit a short-term high feed quality niche.

scholarly journals Detecting Emotions in English and Arabic Tweets

Information ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 98 ◽  
Author(s):  
Tariq Ahmad ◽  
Allan Ramsay ◽  
Hanady Ahmed
Keyword(s):  
Machine Learning ◽  
Neural Networks ◽  
Deep Neural Networks ◽  
State Of The Art ◽  
Learning Algorithms ◽  
General Purpose ◽  
Machine Learning Algorithms ◽  
Current State ◽  
Optimal Thresholds ◽  
Alternative Approach

Assigning sentiment labels to documents is, at first sight, a standard multi-label classification task. Many approaches have been used for this task, but the current state-of-the-art solutions use deep neural networks (DNNs). As such, it seems likely that standard machine learning algorithms, such as these, will provide an effective approach. We describe an alternative approach, involving the use of probabilities to construct a weighted lexicon of sentiment terms, then modifying the lexicon and calculating optimal thresholds for each class. We show that this approach outperforms the use of DNNs and other standard algorithms. We believe that DNNs are not a universal panacea and that paying attention to the nature of the data that you are trying to learn from can be more important than trying out ever more powerful general purpose machine learning algorithms.

scholarly journals Broad-Coverage Parsing Using Human-Like Memory Constraints

2010 ◽  
Vol 36 (1) ◽  
pp. 1-30 ◽  
Author(s):  
William Schuler ◽  
Samir AbdelRahman ◽  
Tim Miller ◽  
Lane Schwartz
Keyword(s):  
Storage Capacity ◽  
Short Term Memory ◽  
Hidden Markov ◽  
General Purpose ◽  
Syntactic Processing ◽  
Short Term ◽  
Bounded Memory ◽  
Memory Store ◽  
Left Corner ◽  
Memory Constraints

Human syntactic processing shows many signs of taking place within a general-purpose short-term memory. But this kind of memory is known to have a severely constrained storage capacity—possibly constrained to as few as three or four distinct elements. This article describes a model of syntactic processing that operates successfully within these severe constraints, by recognizing constituents in a right-corner transformed representation (a variant of left-corner parsing) and mapping this representation to random variables in a Hierarchic Hidden Markov Model, a factored time-series model which probabilistically models the contents of a bounded memory store over time. Evaluations of the coverage of this model on a large syntactically annotated corpus of English sentences, and the accuracy of a a bounded-memory parsing strategy based on this model, suggest this model may be cognitively plausible.

An Innovative Adaptation of General Purpose Accounting Software for a Municipal Social Services Agency

2000 ◽  
pp. 249-262
Author(s):  
Andrew Schiff ◽  
Tigineh Mersha
Keyword(s):  
Social Services ◽  
Transaction Processing ◽  
General Purpose ◽  
Development Costs ◽  
Alternative Approach ◽  
Wide Range ◽  
Long Time ◽  
Accounting Software ◽  
Processing Errors ◽  
General Purpose Software

Organizations with unique characteristics and transaction processing requirements, such as government agencies, often satisfy these requirements by (a) acquiring software from vendors who have developed applications for that particular type of organization, or (b) developing software internally from scratch. When either of these approaches is taken, the development costs are spread over a relatively small number of organizations, and the resulting system can be very expensive. Also, due to the uniqueness of the application and the relatively small number of users, it may take a long time to identify and correct any processing errors. An alternative is to acquire generalpurpose software that has been developed for a wide range of organizations, and to adapt it for the agency in which it will be installed. However, this alternative approach is frequently not undertaken because it is often believed that general-purpose software is unable to provide all of the information required by the organization. When the required information can be provided, though, general-purpose software can be less expensive and less timeconsuming to implement.

Estimation of Extreme Ship Response

2012 ◽  
Vol 56 (01) ◽  
pp. 23-34
Author(s):  
Wengang Mao ◽  
Igor Rychlik
Keyword(s):  
Gaussian Model ◽  
Container Ship ◽  
Short Term ◽  
Sea State ◽  
High Quantiles ◽  
Alternative Approach ◽  
Extreme Response ◽  
Heading Angle ◽  
Ship Speed

In practice the severity of ship response is measured by high quantiles of long-term distribution of the response. The distribution is estimated by combining the short-term distribution of the response with a long-term probability distribution of encountered sea states. The paper describes an alternative approach, the so-called Rice's method, based on estimation of expected number of upcrossings of high levels by stress during 1 year. The method requires description of long-term variability of the standard deviation, skewness, kurtosis, and zero upcrossing frequency of ship response. It is assumed that the parameters are functions of encountered significant wave height, heading angle, and ship speed. The relation can be estimated from the measured stresses or computed by dedicated software assuming rigid ship hull model. Then Winterstein's transformed Gaussian model is used to estimate the upcrossing rates of response during a sea state. The proposed method is validated using the full-scale measurements of a 2,800 TEU container ship during the first 6 months of 2008. Numerical estimation of 4,400 TEU container ship extreme of the extreme response for a 4400 TEU container ship illustrates the approach when no measurements are available.

scholarly journals Ergonomics

AAOHN Journal ◽  
1992 ◽  
Vol 40 (3) ◽  
pp. 105-112 ◽  
Author(s):  
Thomas J. Sluchak
Keyword(s):  
Individual Differences ◽  
Working Conditions ◽  
Health And Safety ◽  
Human Being ◽  
Short Term ◽  
Repetitive Tasks ◽  
Occupational Setting ◽  
The Individual ◽  
Full Stature ◽  
Individual Human

Ergonomics is not a panacea. Ergonomics focuses first on fitting the job to the worker, then on fitting the worker into the job. The appropriate application of ergonomic principles, while keeping in mind the individual differences among workers, will lead to improvement in the health and safety of any occupational setting. Perhaps the real significance of ergonomic programs is best considered in light of the possible alternatives. These words from Weiner (1950), also cited by Christensen (1987), sum up the problem of taking a narrow, short term view of the workplace, and the consequences of failing to actively strive for improved ergonomic working conditions: It is a degradation to a human being to chain him to an oar and use him as a source of power; but it is an almost equal degradation to assign him purely repetitive tasks in a factory, which demand less than a millionth of his brainpower. But it is simpler to organize a factory or galley which uses individual human being for a trivial fraction of their worth than it is to provide a world in which they can grow to their full stature (Weiner, 1950).

The complementary nature of linguistic mediation in transnational adoption mobility

2018 ◽  
Vol 42 (3) ◽  
pp. 328-343
Author(s):  
Alice Fiorentino
Keyword(s):  
Language Learning ◽  
General Purpose ◽  
Adoptive Parents ◽  
Transnational Adoption ◽  
Short Term ◽  
Adoptive Families ◽  
Self Reliance ◽  
Linguistic Strategies ◽  
Translation Services ◽  
Complementary Nature

Abstract In order to explore why people in multilingual contexts choose one mediation strategy or another, we conducted case studies involving short-term mobility for adoption purposes. For parents who adopt a child born in a different country, the experience necessitates a range of linguistic strategies that include language learning, interpreting and translation services, lingua francas, and intercomprehension. A study of ten Italian transnational adoptive families shows that adoptive parents tend to combine these strategies according to the situational relevance of four mobility-related variables: parental agency, accuracy of information, self-reliance, and intimacy. The adoptive parents’ opinions about the benefits and limitations of each strategy indicate that mediation strategies are complementary means to reach the complex general purpose of acquiring parenthood.

scholarly journals Treatment of Aortic and Iliac Artery Aneurysms with Multilayer Flow Modulator: Single Centre Experiences

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Cengiz Ovalı ◽  
Aykut Şahin ◽  
Murat Eroğlu ◽  
Sinan Balçın ◽  
Sadettin Dernek ◽  
...  
Keyword(s):  
Iliac Artery ◽  
Thoracoabdominal Aortic Aneurysm ◽  
Cerebrovascular Event ◽  
Short Term ◽  
Neurological Sequelae ◽  
The Third ◽  
Alternative Approach ◽  
Clinical Presentations ◽  
Patient Groups ◽  
Lateral Branches

Objective. Presenting early and midterm results of aortic and iliac artery aneurysms treated with Multilayer Flow Modulators (MFM). Methods. We retrospectively reviewed the medical records of 23 patients (19 males and 4 females) who are admitted to our clinic between April of 2014 and February of 2016, diagnosed with thoracoabdominal aortic aneurysm and/or iliac aneurysm, and treated using MFM. The patients were followed up for the development of potential clinical presentations for 12 months. Results. MFM implantation was successfully completed in all the patients. During the process, two patients developed endoleak and so they were treated with postdilatation that was performed through balloon intervention, whereby the patients fully recovered. Although a short-term ischemic cerebrovascular event occurred in one of the patients 36 hours after the MFM, the patient recuperated without any noticeable neurological sequelae. Overall, three patients died after the procedure, one of whom died in hospital three days following the intervention due to acute renal failure, while the second one lost his life at the end of the first month due to the occlusion of superior mesenteric and celiac arteries. The third patient died at the end of the third month due to acute myocardial infarction. The rest of the patients developed no complications or had no mortality at their 12-month follow-ups. Conclusion. MFM can be preferred as an alternative approach in the treatment of aorta and iliac artery aneurysms including major lateral branches. The present results should be confirmed with additional future studies conducted with larger patient groups for longer periods.

scholarly journals Ecological and evolutionary opportunities of apomixis: insights from Taraxacum and Chondrilla

2003 ◽  
Vol 358 (1434) ◽  
pp. 1113-1121 ◽  
Author(s):  
Peter J. van Dijk
Keyword(s):  
Clonal Diversity ◽  
General Purpose ◽  
Biological Interactions ◽  
Deleterious Mutations ◽  
Adaptive Potential ◽  
Short Term ◽  
Close Phylogenetic Relationship ◽  
Evolutionary Success ◽  
Ecological Success

The ecological and evolutionary opportunities of apomixis in the short and the long term are considered, based on two closely related apomictic genera: Taraxacum (dandelion) and Chondrilla (skeleton weed). In both genera apomicts have a wider geographical distribution than sexuals, illustrating the short–term ecological success of apomixis. Allozymes and DNA markers indicate that apomictic populations are highly polyclonal. In Taraxacum , clonal diversity can be generated by rare hybridization between sexuals and apomicts, the latter acting as pollen donors. Less extensive clonal diversity is generated by mutations within clonal lineages. Clonal diversity may be maintained by frequency–dependent selection, caused by biological interactions (e.g. competitors and pathogens). Some clones are geographically widespread and probably represent phenotypically plastic ‘general–purpose genotypes’. The long–term evolutionary success of apomictic clones may be limited by lack of adaptive potential and the accumulation of deleterious mutations. Although apomictic clones may be considered as ‘evolutionary dead ends’, the genes controlling apomixis can escape from degeneration and extinction via pollen in crosses between sexuals and apomicts. In this way, apomixis genes are transferred to a new genetic background, potentially adaptive and cleansed from linked deleterious mutations. Consequently, apomixis genes can be much older than the clones they are currently contained in. The close phylogenetic relationship between Taraxacum and Chondrilla and the similarity of their apomixis mechanisms suggest that apomixis in these two genera could be of common ancestry.

scholarly journals Why subject relatives prevail: Constraints versus constructional licensing

2011 ◽  
Vol 3 (2) ◽  
pp. 171-208 ◽  
Author(s):  
Cecily Jill Duffield ◽  
Laura A. Michaelis
Keyword(s):  
Relative Clause ◽  
Relative Clauses ◽  
Short Term Memory ◽  
General Purpose ◽  
Formal Semantic ◽  
Short Term ◽  
Term Memory ◽  
The Subject ◽  
Relative Pronouns ◽  
National Corpus

AbstractRelative clauses containing subject relative-pronouns (e.g. that go to Utah all the time,) are the prevalent type both across languages (Keenan and Comrie 1977) and in conversation, accounting for 65% of relative clauses in the American National Corpus (Reali and Christiansen 2007) and 67% of relative clauses in the corpus examined for this study, the Switchboard corpus. This fact appears attributable to parsing preferences, as per Hawkins (1999, 2004), Gibson (1998) and Gibson et al. (2005): subject extractions are the most local filler-gap dependency and therefore impose the lowest burden on short-term memory. This explanation, however, not only lacks strong psycholinguistic support but also fails to explain a major pattern in Switchboard: subject relatives are not preferred across the board but only as modifiers of postverbal (object and oblique) nominals. We propose that the preference for subject relatives is an effect not of general-purpose interpretive or encoding constraints but rather of constructional licensing: the subject relative belongs to an entrenched syntactic routine, the Presentational Relative construction, e.g. I have friends that clip articles (McCawley 1981; Lambrecht 1987, 1988, 2002). We investigate this hypothesis by examining the formal, semantic and pragmatic properties of relative-clause modifiers of postverbal nominals in the Switchboard corpus.

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