• Smart Structures and Systems
• /
• v.22 no.1
• /
• pp.105-120
• /
• 2018

In this paper, the nonlinear free and forced vibration responses of sandwich nano-beams with three various functionally graded (FG) patterns of reinforced carbon nanotubes (CNTs) face-sheets are investigated. The sandwich nano-beam is resting on nonlinear Visco-elastic foundation and is subjected to thermal and electrical loads. The nonlinear governing equations of motion are derived for an Euler-Bernoulli beam based on Hamilton principle and von Karman nonlinear relation. To analyze nonlinear vibration, Galerkin's decomposition technique is employed to convert the governing partial differential equation (PDE) to a nonlinear ordinary differential equation (ODE). Furthermore, the Multiple Times Scale (MTS) method is employed to find approximate solution for the nonlinear time, frequency and forced responses of the sandwich nano-beam. Comparison between results of this paper and previous published paper shows that our numerical results are in good agreement with literature. In addition, the nonlinear frequency, force response and nonlinear damping time response is carefully studied. The influences of important parameters such as nonlocal parameter, volume fraction of the CNTs, different patterns of CNTs, length scale parameter, Visco-Pasternak foundation parameter, applied voltage, longitudinal magnetic field and temperature change are investigated on the various responses. One can conclude that frequency of FG-AV pattern is greater than other used patterns.

• Coupled systems mechanics
• /
• v.5 no.1
• /
• pp.41-58
• /
• 2016

The study deals with physical modeling of a typical building frame resting on pile raft foundation and embedded in cohesive soil mass using finite element based software ETABS. Both- the elements of superstructure and substructure (i.e., foundation) including soil is assumed to remain in elastic state at all the time. The raft is modelled as a thin plate and the pile and soils are treated as interactive springs. Both- the resistance of the piles as well as that of raft base - are incorporated into the model. Interactions between raft-soil-pile are computed. The proposed method makes it possible to solve the problems of uniformly and large non-uniformly arranged piled rafts in a time saving way using finite element based software ETABS. The effect of the various parameters of the pile raft foundation such as thickness of raft and pile diameter is evaluated on the response of superstructure. The response included the displacement at the top of the frame and bending moment in columns. The soil-structure interaction effect is found to increase displacement and increase the absolute maximum positive and negative moments. The effect of the soil- structure interaction is observed to be significant for the type of foundation and soil considered in the present study.

• Korean journal of applied entomology
• /
• v.28 no.4
• /
• pp.221-228
• /
• 1989

The oviposition behavior of Ooencyrtus kuvanae (Howard) (Hymenoptera: Encyridae) was examined in a small petri dish containing eggs of gypsy moth, Lymantrt'a dt'spar L. The behavioral sequence from initial searching movement toward the host egg through oviposition, departure, and auxiliary phase activities such as resting, glooming, and host feeding were described. Oviposition experience shortened the approach time to subsequent eggs. The time spent for contacting the host egg also decreased with oviposition experience. Oviposition experience may play an important role in host recognition and increasing oviposition efficiency.

• Journal of Embryo Transfer
• /
• v.32 no.4
• /
• pp.305-310
• /
• 2017

Miniature pig (minipig) has been considered as an important laboratory animal in the developmental biotechnology researches with respect to xenotransplantation, stem cell, somatic cell nuclear transfer and embryo transfer. Given that the laboratory minipigs are normally housed at an indoor facility, they pass the time with lying or sleeping unless it is feeding time. Therefore, it is necessary to provide environmental enrichments to satisfy their innate needs and to lessen atypical behaviors caused by stress, on the purpose of welfare. We quantitatively investigated the type of preferable enrichment for the laboratory minipigs as well as its effect on their daily life. They presented a great interest to the pliable pail but a rapid loss of attraction to non-preferable enrichments. When the daily life of the single housed minipigs was quantified based on duration of playing or resting, they were more actively engaged in lively activities in the presence of enrichments. In addition, the provision of enrichments could effectively alleviate the conflicts during group housing when new pen mate was introduced, resulting in reduction of wound cases. We believe the considerations of animal welfare are essential to the conduct of better research because animals in the non-stressful environment will be more physiologically stable and provide more reliable results in the animal experiments.

• Korean Journal of Acupuncture
• /
• v.32 no.3
• /
• pp.130-135
• /
• 2015

Objectives : This study is to investigate stimulation effects of acupoints at differential meridian along arm and leg on the physiological phenomenon of heartbeats. Methods : 8 subjects were participated in this study. The experiments were performed in Resting session(Rs), Insertion session(Is), Stimulation session1(Ss1), Stimulation session2(Ss2), Stimulation session3(Ss3) sequence. Time of each session and the interval between each session was 30 seconds all. Acupuncture was performed manually on PC3 or LR8 at random with a two-day interval. stand deviation of N-N interval(SDNN) was measured for each session. Results : At PC3, SDNN increased in Ss1, Ss2, and Ss3 compared to Rs but at LR8, there was little change between Ss1, Ss2, Ss3 and Rs. Post-hoc analysis revealed that mean value of SDNN significantly increased in Ss1 compared with Baseline at PC3, while there was little change at LR8. When LR8 and PC3 were compared at each time point, there was a significant difference only in Ss1. Conclusions : Our results indicate that there is a correlation between specific physiological functions and acupoints.

• Geomechanics and Engineering
• /
• v.7 no.4
• /
• pp.355-374
• /
• 2014

An analytical solution of the fully coupled system of equations governing the plane strain deformation of a poroelastic medium with anisotropic permeability and compressible fluid and solid constituents is obtained. This solution is used to study the consolidation of a poroelastic clay layer with free permeable surface resting on a rough-rigid permeable or impermeable base. The stresses and the pore pressure are taken as the basic state variables. Displacements are obtained by integrating the coupled constitutive relations. The case of normal surface loading is discussed in detail. The solution is obtained in the Laplace-Fourier domain. Two integrations are required to obtain the solution in the space-time domain which are evaluated numerically for normal strip loading. Consolidation of the clay layer and diffusion of pore pressure is studied for both the bases. It is found that the time settlement is accelerated by the permeability of the base. Initially, the pore pressure is not affected by the permeability of the base, but has a significant effect, as we move towards the bottom of the layer. Also, anisotropy in permeability and compressibilities of constituents of the poroelastic medium have a significant effect on the consolidation of the clay layer.

• Journal of International Academy of Physical Therapy Research
• /
• v.10 no.1
• /
• pp.1739-1745
• /
• 2019

Background: There have been many studies on self-myofascial release (SMR) stretching, but there are few comparative studies on the effects of massages using a release ball, which is a type of the SMR method. Objective: To investigate the immediate effects of release ball massage and self-stretching on proprioceptive sensory, hamstring's temperature, range of motion (ROM) muscle strength,. Design: Crossover study. Methods: Thirty women in 20's at S University in Busan voluntarily participated in the study. Participants were random to release ball group (n=15) or self-stretching group (n=15). Both groups performed 3 sets of exercises, stretching for 30 seconds and resting for 15 seconds in each position. The proprioceptive sensory, temperature of the hamstring muscle, ROM, and strength were measured before exercise, 5 minutes after exercise, and 30 minutes after exercise. Results: Release ball group showed significant differences in muscle length and temperature over time (p<.05). The comparison between two group over time showed significant differences in muscle length, temperature, and muscle strength (p<.05). Conclusions: These results demonstrate that release ball massage and self-stretching are beneficial for improving hamstring's temperature, ROM and muscle strength.

• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.11
• /
• pp.1469-1475
• /
• 2010

A study was conducted to investigate the effects of methods of feeding a total mixed ration (TMR) on behavior patterns of growing Hanwoo steers. A total of 15 growing steers (13 months old) were assigned to the control (fed roughage and concentrate mix separately), TMR1 (fed restricted TMR), and TMR2 (fed TMR ad libitum) groups. Individual behaviors of steers were observed for 48 hours. Compared with the control, feeding restricted TMR (TMR1) resulted in short eating time, long ruminating time, short chewing time, high frequencies of defecation, urination, and drinking of water, great numbers of boluses and chews, long ruminating time per bolus, low feed value index, high eating and chewing efficiencies (p<0.05). Compared with feeding restricted TMR (TMR1), feeding TMR ad libitum (TMR2) resulted in 1.2 kg more daily feed DM intake, long eating and chewing times, short resting time, great frequencies of defecation, urination and drinking of water, more numbers of boluses and chews, long ruminating time per bolus, low feed value index, low eating and high ruminating efficiencies (p<0.05) and similar chewing efficiency (p>0.05). Considering all these results, the wet TMR feeding system induced generally more desirable eating and ruminating behaviors of growing Hanwoo steers, but made the barn floor wetter due to more defecation and urination.

• Journal of Biomedical Engineering Research
• /
• v.28 no.2
• /
• pp.258-264
• /
• 2007

Spatiotemporal changes of brain rhythmic activity at a certain frequency have been usually monitored in real time using scalp potential maps of multi-channel electroencephalography(EEG) or magnetic field maps of magnetoencephalography(MEG). In the present study, we investigate if it is possible to implement a real-time brain activity monitoring system which can monitor spatiotemporal changes of cortical rhythmic activity on a subject's cortical surface, neither on a sensor plane nor on a standard brain model, with a high temporal resolution. In the suggested system, a frequency domain inverse operator is preliminarily constructed, considering the individual subject's anatomical information, noise level, and sensor configurations. Spectral current power at each cortical vertex is then calculated for the Fourier transforms of successive sections of continuous data, when a single frequency or particular frequency band is given. An offline study which perfectly simulated the suggested system demonstrates that cortical rhythmic source changes can be monitored at the cortical level with a maximal delay time of about 200 ms, when 18 channel EEG data are analyzed under Pentium4 3.4GHz environment. Two sets of artifact-free, eye closed, resting EEG data acquired from a dementia patient and a normal male subject were used to show the feasibility of the suggested system. Factors influencing the computational delay are investigated and possible applications of the system are discussed as well.

• Investigative Magnetic Resonance Imaging
• /
• v.25 no.1
• /
• pp.1-9
• /
• 2021

The aim of this study was to provide a new assessment of rotator cuff muscle activity. Eight male subjects (24.7 ± 3.2 years old,171.2 ± 9.8 cm tall, and weighing 63.8 ± 11.9 kg) performed the study exercises. The subjects performed 10 sets of the exercise while fixing the elbow at 90 degrees flexure and lying supine on a bed. One exercise set consisted of the subject performing external shoulder rotation 50 times using training equipment. Two imaging protocols were employed: (a) true fast imaging with steady precession (TrueFISP) at an acquisition time of 12 seconds and (b) multi-shot spin-echo echo-planar imaging (MSSE-EPI) at an acquisition time of 30 seconds for one echo. The main method of assessing rotator cuff muscle activity was functional T2 mapping using ultrafast imaging (fast-acquired muscle functional MRI [fast-mfMRI]). Fast-mfMRI enabled real-time imaging for the identification and evaluation of the degree of muscle activity induced by the exercise. Regions of interest were set at several places in the musculus subscapularis (sub), musculus supraspinatus (sup), musculus teres minor (ter), and deltoid muscle (del). We used the MR signal of the images and transverse relaxation time (T2) for comparison. Most of the TrueFISP signal was not changed by exercise and there was no significant difference from the resting values. Only the T2 in the musculus teres minor was increased after one set and the change were seen on the T2 images. Additionally, except for those after one and two sets, the changes in T2 were significant compared to those at rest (P < 0.01). We also demonstrated identify and visualize the extent to which muscles involved in muscle activity by exercise. In addition, we showed that muscle activity in a region such as a shoulder, which is susceptible to B0 inhomogeneity, could be easily detected using this technique.