1,371 research outputs found
Image based visual servoing using bitangent points applied to planar shape alignment
We present visual servoing strategies based on bitangents for aligning planar shapes. In order to acquire bitangents we use convex-hull of a curve. Bitangent points are employed in the construction of a feature vector to be used in visual control. Experimental results obtained on a 7 DOF Mitsubishi PA10 robot, verifies the proposed method
Positioning and trajectory following tasks in microsystems using model free visual servoing
In this paper, we explore model free visual servoing algorithms by
experimentally evaluating their performances for various tasks
performed on a microassembly workstation developed in our lab. Model
free or so called uncalibrated visual servoing does not need the
system calibration (microscope-camera-micromanipulator) and the
model of the observed scene. It is robust to parameter changes and
disturbances. We tested its performance in point-to-point
positioning and various trajectory following tasks. Experimental
results validate the utility of model free visual servoing in
microassembly tasks
Web and Java based architecture for laboratory experiments
Thesis (Master)--Izmir Institute of Technology, Computer Engineering, Izmir, 2003Includes bibliographical references (leaves: 54-55)Text in English; Abstract: Turkish and Englishix, 55 leavesDevelopments in the communication technologies area have increased the popularity of usage of communication channels for the education activities.Being one of these communication channels, Internet, has become an inevitable component for theoretical education.Internet has brought together instructor and student without any geographical constraint.But having different requirements and difficulties during the satisfaction of these requirements are the common drawbacks for the widespread usage of Internet for laboratory educations.In this thesis, methodologies, which can be used in remote laboratory systems, have been discussed. Requirements have been scrutinized and refined.Remote laboratory architecture for IYTE has been proposed according to these requirements.Analysis of software that can be developed on the proposed architecture has been made
Lip segmentation using adaptive color space training
In audio-visual speech recognition (AVSR), it is beneficial
to use lip boundary information in addition to texture-dependent
features. In this paper, we propose an automatic lip segmentation
method that can be used in AVSR systems. The algorithm
consists of the following steps: face detection, lip corners extraction,
adaptive color space training for lip and non-lip regions
using Gaussian mixture models (GMMs), and curve evolution
using level-set formulation based on region and image
gradients fields. Region-based fields are obtained using adapted
GMM likelihoods. We have tested the proposed algorithm on a
database (SU-TAV) of 100 facial images and obtained objective
performance results by comparing automatic lip segmentations
with hand-marked ground truth segmentations. Experimental
results are promising and much work has to be done to improve
the robustness of the proposed method
İki noktada teğetler kullanarak görüntü tabanlı görsel geri beslemeli kontrol ile düzlemsel şekil hizalama
Bu bildiride, düzlemsel şekilleri hizalamak için iki noktada teğetlerden (bitangent) faydalanan görsel geri beslemeli kontrol stratejileri sunulmuştur. Bitangentları elde etmek ic¸in bir eğrinin dışbükey zarfından (convex-hull) yararlanılmıştır. İmge nitelik vektörü bitangent noktalarından oluşturularak görsel kontrolde kullanılmıştır. 7 serbestlik dereceli Mitsubishi PA10 robotu üzerinde gerçekleştirilen deneyler önerilen metodun geçerliliğini göstermiştir
Model-based vs. model-free visual servoing: A Performance evaluation in microsystems
In this paper, model-based and model-free image based visual servoing (VS) approaches are implemented on a microassembly workstation, and their regulation and tracking performances are evaluated. A precise image based VS relies on computation of the image jacobian. In the model-based visual servoing, the image Jacobian is computed via calibrating the optical system. Precisely calibrated model based VS promises better positioning and tracking performance than the model-free approach. However, in the model-free approach, optical system calibration is not required due to the dynamic Jacobian estimation, thus it has the advantage of adapting to the different operating modes
İneklerde geçiş döneminde anti-müllerian hormon, metabolik profil ve mineral düzeylerinin buzağılama – gebelik aralığına etkisi
The transition period in dairy cows is generally accepted as the period covering 3 weeks before calving and 3 weeks after calving. The aim of the study was to compare the profiles of β-hydroxybutyrate, calcium, magnesium, phosphorus, total cholesterol, total protein, triacylglycerol, free glycerol, serum lipid and serum protein with Anti-Mullerian Hormone (AMH) in dairy cows in the transition period, and to determine whether AMH to examine whether it can be used as a marker in the next insemination period. The cows whose blood samples were taken were followed up and it was determined that they became pregnant at the insemination and the study was terminated. According to the results obtained; It was determined that BHB and free glycerol, which are important markers of negative energy balance (NEB), have an effect on AMH concentration. However, it was determined that the concentration of magnesium and the ratio of cholesterol ester in serum total fat did not change much during the transition period. Our results suggest that AMH is a good biomarker of decreased follicular activity due to NEB in the transition period and that AMH can be used for herd weeding in reinsemination.Sütçü ineklerde geçiş dönemi genel kabul ile buzağılamadan önceki 3 hafta ile buzağılamadan sonraki 3 haftatı kapsayan süreçtir. Bu çalışmanın amacı geçiş dönemindeki sütçü ineklerde negaif eneji dengesinden (NED) dolayı değişen β-hidroksibütirat, kalsiyum, magnezyum, fosfor, total kolesterol, total protein, triaçilgliserol, serbest gliserol, serum lipid ve serum protein profillerinin Anti-Müllerian Hormon (AMH) ile karşılaştırılarak AMH’nin bir sonraki tohumlama döneminde belirteç olarak kullanılıp lullanılmayacağını incelemektir. Kan örnekleri alınan inekler daha sonra takip edilerek kaçıncı tohumlamada gebe kaldıkları tespit edildi ve çalışma sonlandırıldı. Santrifüj edilerek serumları toplanan kanlar analiz edildi. Elde edilen sonuçlara göre; NED’in önemli belirteçlerinden BHB’nin ve serbest gliserolün AMH konsantrasyonu üzerine etkisi olduğu saptandı. Bununla birlikte, magnezyumun konsantrasyonunun ve serum toplam yağı içerisindeki kolesterol esteri oranının geçiş döneminde fazla değişmediği tespit edildi. Sonuçlarımız AMH’nin geçiş döneminde NED’den dolayı azalan folliküler aktivitenin iyi bir biyobelirteci olduğunu ve tekrar tohumlamada AMH’nin sürü ayıklama için kullanılabileceğini göstermektedir
Axial vibration analysis of cracked nanorods with arbitrary boundary conditions
The axial vibration of cracked nanorods (carbon nanotubes) with arbitrary boundary conditions is studied. The nonlocal elasticity theory is used, and the crack severity is modeled by an axial spring representing the discontinuity in the axial displacement. The present model is set up by dividing the nanorod into two segments connected by an axial spring located at the cracked section. The axial displacement functions are sought as the combination of two Fourier sine series and Stokes’ transformation. Vibration frequencies of a nanorod for variant crack positions under different boundary conditions are calculated by means of the proposed method. The purpose of this study is mainly to present a general analytical method for the dynamical analysis of cracked nanorods with arbitrary boundary conditions (rigid or restrained) rather than to investigate a specific problem
NMR SPECTROSCOPIC STUDY AND DFT CALCULATIONS OF VIBRATIONAL ANALYSES, GIAO NMR SHIELDINGS AND 1JCH, 1JCC SPIN-SPIN COUPLING CONSTANTS OF 1,7-DIAMINOHEPTANE
Vibrational frequencies and approximate mode descriptions of 1,7-diaminoheptane (dahp) have been determined via Becke-3-Lee-Yang-Parr (B3LYP) density functional method with 6-31G(d) basis set. 1H, proton coupled and uncoupled 13C, 15N, DEPT, COSY, HETCOR, INADEQUATE NMR spectra and the magnitude of one bond 1JCH, 1JCC coupling constants of dahp (C7H18N2) have been reported for the first time. 1H, 13C, 15N NMR chemical shifts and 1JCH, 1JCC coupling constants of dahp have been calculated by means of B3LYP density functional method with 6-311++G(d,p) basis set. Comparison between the experimental and the theoretical results indicates that density functional B3LYP method is able to provide satisfactory results for predicting vibrational frequencies and NMR properties.KEY WORDS: 1,7-Diaminoheptane, Vibrational assignments, NMR, GIAO, DFTBull. Chem. Soc. Ethiop. 2009, 23(1), 85-96
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