3,283 research outputs found
Disconnected Skeleton: Shape at its Absolute Scale
We present a new skeletal representation along with a matching framework to
address the deformable shape recognition problem. The disconnectedness arises
as a result of excessive regularization that we use to describe a shape at an
attainably coarse scale. Our motivation is to rely on the stable properties of
the shape instead of inaccurately measured secondary details. The new
representation does not suffer from the common instability problems of
traditional connected skeletons, and the matching process gives quite
successful results on a diverse database of 2D shapes. An important difference
of our approach from the conventional use of the skeleton is that we replace
the local coordinate frame with a global Euclidean frame supported by
additional mechanisms to handle articulations and local boundary deformations.
As a result, we can produce descriptions that are sensitive to any combination
of changes in scale, position, orientation and articulation, as well as
invariant ones.Comment: The work excluding {\S}V and {\S}VI has first appeared in 2005 ICCV:
Aslan, C., Tari, S.: An Axis-Based Representation for Recognition. In
ICCV(2005) 1339- 1346.; Aslan, C., : Disconnected Skeletons for Shape
Recognition. Masters thesis, Department of Computer Engineering, Middle East
Technical University, May 200
A Multi-agent Reinforcement Learning Study of Emergence of Social Classes out of Arbitrary Governance: The Role of Environment
There are several theories in economics regarding the roots or causes of
prosperity in a society. One of these theories or hypotheses -- named geography
hypothesis -- mentions that the reason why some countries are prosperous and
some others are poor is the geographical location of the countries in the world
as makes their climate and environment favorable or unfavorable regarding
natural resources. Another competing hypothesis states that man-made
institutions particularly inclusive political institutions are the reasons why
some countries are prosperous and some others are poor. On the other hand,
there is a specific political theory developed for the long-term social
development in Iran -- named Arbitrary Rule and Aridisolatic Society which
particularly emphasizes on the role of aridity to shape arbitrary political and
economical institutions in Iran, without any functional social classes in the
society. In this paper, by extending the AI-Economist -- a recently developed
two-level multi-agent reinforcement learning environment -- I show that when
the central planner is ruling the environment by arbitrary rules, the society
evolves through different paths in different environments. In the environment
having band-like vertical isolated patches of natural resources, all mobile
agents are equally exploited by the central planner and the central planner is
also not gaining any income, while in the society having more uniformly
distributed natural resources, the productivity and Maximin are higher and the
society generates a heterogeneous stratified social structure. All these
findings provide a partial answer to the above debate and reconcile the role of
geography and political institutions on the long-term development in a region
Harmonic analysis of precipitation, pressure and temperature over Turkey
Monthly averages of temperature, precipitation and pressure values from ground-based measurements for long-term data observed in different geographical regions in Turkey have been investigated. The main purpose of this study is to define the role of small- and large-scale phenomena (local and synoptic fluctuations) on precipitation, pressure and temperature variations and their periods. Hence, the Fourier transformation analysis of the monthly average value of meteorological parameters has been considered, and phase angles and amplitudes have been calculated. The
first-order harmonics of temperature, precipitation and pressure values show large-scale effects, while higher-order harmonics show the effects of small-scale variations. The variations of first–sixth-order harmonic amplitudes and phases provide a useful means of understanding the
large- and local-scale effects on meteorological parameters. The phase angle can be used to determine the time of the year when the maximum or minimum of a given harmonic occurs. The analysis helps us distinguish different precipitation, pressure and temperature regimes and transition regions. Local- and large-scale phenomena and
some unusual seasonal patterns are also defined. This analysis also shows strong annual variations of precipitation in the Southern and Western part of Anatolia and that strong semi-annual fluctuations are predominant in the eastern part of Turkey. Strong annual influence on pressure variations is mostly observed in the coastal part
of Turkey. The dominance of the first three harmonics of pressure is smaller over most of the terrestrial stations. Temperature variations are mostly influenced by the annual fluctuations in eastern and south-eastern Anatolia. The urban heat Island caused by developing metropolitan areas refers to local warming effects and heat islands. The local effects are observed in the western part of Turkey
Učinak nepravilne primjene intravaginalnog umetka za otpuštanje progesterona na plodnost holštajnsko-frizijske krave: prikaz slučaja.
In this case report, the surgical removal of a progesterone-releasing intravaginal device (PRID®, 1.55 g of progesterone) found adhered to the uterus was performed, and its effect on fertility in a Holstein-Friesian cow evaluated. No data older than six months was available on the cow; however, during the preceding sixmonth period, the animal showed no signs of estrus. Interestingly, in the course of a reproductive examination, a PRID-like spiral mass was identified on the right uterine horn. Following diagnosis of the mass, surgical removal was considered. Right flank laparotomy was selected as the surgical entry site. Approximately one month after surgery, the cow showed signs of estrus, but no insemination was performed until the third cycle. After insemination, the cow become pregnant and completed the gestation period. Therefore, we concluded that the PRID may have caused anestrus, and that right flank laparotomy was a safe procedure for the removal of a PRID from the uterus, and particularly to recover fertility, in this case.U prikazu slučaja opisano je kirurško uklanjanje intravaginalnog umetka za otpuštanje progesterona (PRID®, 1,55 g progesterona). Umetak je bio pričvršćen za maternicu krave holštajnsko-frizijske pasmine u koje je obavljena kontrola plodnosti. U prethodnom šestomjesečnom razdoblju nije bilo podataka o kravi, a tijekom sljedećih šest mjeseci kontrole nije bilo znakova estrusa. Tijekom pregleda reprodukcijskih organa, u desnom rogu maternice otkrivena je spiralna tvorevina, slična umetku. Nakon postavljene dijagnoze razmatrana je mogućnost kirurškog uklanjanja. Odabrana je laparotomija s pristupom na desnoj bočnoj strani. Približno mjesec dana nakon operacije kod krave su opaženi znakovi estrusa, no osjemenjivanje nije obavljeno prije trećeg ciklusa. Nakon osjemenjivanja, krava je postala bređa s normalnim trajanjem gravidnosti. Autori zaključuju da PRID može biti uzrokom izostanka estrusa kod krava. Laparoskopska operacija s desne bočne strane je sigurna metoda za uklanjanje PRID-a iz maternice, posebno s obzirom na uspostavljenu plodnost krave u ovom prikazu
Macroanatomical and histological study of the structure of intercornual gland in Abaza (Capra Aegagrus) and Gurcu (Capra Falconeri) goats breeds
Background: The anatomical localisation of the odour glands, which increase activity during the reproduction period and help goat species to find each other, varies. Materials and methods: In our study, the anatomical and histological structures of the glands around the horn were examined in the Gurcu and Abaza goats, which are native breeds. In this study a total of 12 Abaza and Gurcu goat heads were used.
Results: The area between the two horns and area at the back of the horns were shaved to remove all hair. The distance between the horns of both goat breeds was measured using an electronic calliper. The mean distance between the horns of the Abaza goats was determined as 36.80 ± 8.62 mm while this distance was 39.63 ± 4.10 mm for the Gurcu goats. Gland tissue that could not be seen anatomically under the skin was examined histologically. For the histological examination, skin samples were taken from the anterior, middle, right posterior and left posterior of the area between the two horns of both breeds. Crossman triple staining and haematoxylin and eosin staining were applied to the samples.
Conclusions: Glandula intercornualis was found to be slightly caudal between the horns in both breeds and normal sebaceous glands were almost absent in the areas where these glands were found. Lobes and branched alveolar glands were located around the hair follicles
How Are Curiosity and Interest Different? Naive Bayes Classification of People's Beliefs
Researchers studying curiosity and interest note a lack of consensus in whether and how these important motivations for learning are distinct. Empirical attempts to distinguish them are impeded by this lack of conceptual clarity. Following a recent proposal that curiosity and interest are folk concepts, we sought to determine a non-expert consensus view on their distinction using machine learning methods. In Study 1, we demonstrate that there is a consensus in how they are distinguished, by training a Naïve Bayes classification algorithm to distinguish between free-text definitions of curiosity and interest (n = 396 definitions) and using cross-validation to test the classifier on two sets of data (main n = 196; additional n = 218). In Study 2, we demonstrate that the non-expert consensus is shared by experts and can plausibly underscore future empirical work, as the classifier accurately distinguished definitions provided by experts who study curiosity and interest (n = 92). Our results suggest a shared consensus on the distinction between curiosity and interest, providing a basis for much-needed conceptual clarity facilitating future empirical work. This consensus distinguishes curiosity as more active information seeking directed towards specific and previously unknown information. In contrast, interest is more pleasurable, in-depth, less momentary information seeking towards information in domains where people already have knowledge. However, we note that there are similarities between the concepts, as they are both motivating, involve feelings of wanting, and relate to knowledge acquisition
Laparoscopic artificial insemination in dairy sheep with chilled semen stored for up to 26 h
Adult East Freisan crossbred (n = 220) and Chios ewes (n = 105) were divided into four groups and inseminated with chilled semen, which had been stored for 7, 13, 20 or 26 h at 5°C. Unilateral intrauterine insemination (50 x 106 spermatozoa in 0.25 ml) was performed with the aid of a laparoscope. Inseminations were carried out 48 – 52 h after pessary removal (30 mg FGA) without detecting estrus. The lambing rates after intrauterine insemination with chilled semen were found to be similar in East Fresian crossbred (40%) and Chios ewes (30%). Intrauterine insemination with chilled semen stored up to 26 h resulted in similar lambing rates; whereas, fertility of Chios ewes tended to decline with increased holding time of chilled semen. From this study, it is concluded that decreasing the storage time of chilled semen at 5°C improves pregnancy in Chios ewes and that East Fresian crossbred ewe’s conception rates to intrauterine insemination with chilled semen was relatively higher than Chios ewes.Key words: Dairy sheep, chilled semen, time of insemination, lambing rate
Introduction to the Special Issue: The Role of Seed Dispersal in Plant Populations: Perspectives and Advances in a Changing World
Despite the importance of seed dispersal as a driving process behind plant community assembly, our understanding of the role of seed dispersal in plant population persistence and spread remains incomplete. As a result, our ability to predict the effects of global change on plant populations is hampered. We need to better understand the fundamental link between seed dispersal and population dynamics in order to make predictive generalizations across species and systems, to better understand plant community structure and function, and to make appropriate conservation and management responses related to seed dispersal. To tackle these important knowledge gaps, we established the CoDisperse Network and convened an interdisciplinary, NSF-sponsored Seed Dispersal Workshop in 2016, during which we explored the role of seed dispersal in plant population dynamics (NSF DEB Award # 1548194). In this Special Issue, we consider the current state of seed dispersal ecology and identify the following collaborative research needs: (i) the development of a mechanistic understanding of the movement process influencing dispersal of seeds; (ii) improved quantification of the relative influence of seed dispersal on plant fitness compared to processes occurring at other life history stages; (iii) an ability to scale from individual plants to ecosystems to quantify the influence of dispersal on ecosystem function; and (iv) the incorporation of seed dispersal ecology into conservation and management strategies
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