• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.23 no.6
• /
• pp.491-496
• /
• 2010

The relaxation behavior of aligned electric dipoles in a mixed polymer of P2ANS with P(VDF-TrFE) is studied with optical second harmonic generation (SHG). In this work, a macroscopic noncentrosymmetry of the spin coated film was achieved by an electrical poling. The relaxation of induced polar order of nonlinear optic(NLO) chromophores after poling leads to an insufficient long-term stability of NLO properties. In this work, we develop a new technique to suppress such kind of dipole relaxation in a poled polymer. We found that the poled dipoles in a NLO polymer were effectively immobilized by the internal electric field created by a thermally annealed ferroelectric polymer. The long-term stability in a mixed system of NLO polymer/ferroelectric polymer was successively accomplished by a series of thermal treatments applied to the mixed polymer system at a temperature of $140^{\circ}C$ for at least 1hour after poling.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.8 no.3
• /
• pp.293-301
• /
• 2001

Purpose: The purpose of this study was to investigate the effect of exercise therapy and relaxation therapy on the level of ACTH and cortisol in workers and to determine, from this information, the effectiveness of applied exercise therapy and relaxation therapy as a nursing intervention method for workers experiencing stress. Method: The subjects were divided into an exercise therapy group. a relaxation therapy group, and a control group. The research design was a nonequivalent control group pretest-posttest design (exercise therapy : n=12. relaxation therapy: n=12, control group, the group without exercise or relaxation therapy: n= 12). The subjects in the exercise therapy group were given a particular intensity for each kp over 30 min, bicycle ergometer which uses the LX PE training system before and after four weeks of training. The subjects did 60-70% exercise intensity exercise therapy for eight weeks The relaxation therapy subjects were trained using a modified Jacobson's relaxation technique for eight weeks. The exercise and relaxation therapy groups were trained at the following intensity for eight weeks (3 times/week, 30 min/day). Changes in the levels of ACTH and cortisol were identified. Two-way ANOVA and multiple range test (SNK: Student Newman Keul) were used to examine the effects of exercise therapy and relaxation therapy at four and eight weeks. Result: 1. Changes in the level of ACTH in the relaxation therapy group were statistically significant at .05 level, and were better than that of the exercise therapy group after eight weeks. But there was no significant difference between the exercise therapy group and the control group. 2. Change in the level of cortisol in the relaxation therapy group were statistically significant at .05 level as compared to the exercise therapy group and the control group after four weeks, but not after eight weeks. Also, the relaxation therapy was statistically significant at .05 level after four weeks compared to before treatment, but there was a tendency toward increased cortisol after eight weeks. Conclusion: Relaxation therapy was found to be more effective in stress treatment than exercise therapy and as such is a desirable nursing intervention method for stress hormone reduction in workers.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.67 no.4
• /
• pp.538-542
• /
• 2018

In order to generate a clock source with low cost and high performance in system on chip(SoC), a relaxation oscillator with stable output characteristics according to PVT(process, voltage and temperature) fluctuation require a low area and a low power. In this paper, we propose a solution to reduce the current loss caused by parasitic components in the conventional relaxation oscillator. Since the slew rate of the bias current and the capacitor are adjusted to be the same through the proposed solution, a relaxation oscillator with low area characteristics is designed for the same clock source frequency implementation. The proposed circuit is designed using the TSMC CMOS 0.18um process. The Simulation results show that the relaxation oscillator using the proposed solution can prevent the current loss of about $279{\mu}A$ and reduce the total chip area by 20.8% compared with the conventional oscillator in the clock source frequency of 96 MHz.

• Journal of Oriental Neuropsychiatry
• /
• v.18 no.1
• /
• pp.111-122
• /
• 2007

Objective : Progressive muscle relaxation(PMR) therapy is the way of mind and body self-regulation which makes major muscles tension to be comfortable condition. It was considered to be important to check the level of relaxation in objective validity. Therefore, Heart rate variability(HRV) is the valuable measurement to investigate the effect of progressive muscle relaxation therapy on autonomic nerve system. Method : I studied 38 subjects. The subjects were measured HRV at first. And then, Using a CD player, the subjects listened to recorded PMR program for 15 minutes. After this progress, I rechecked HRV. Results : heart rate item of HRV was significantly decreased. Also, the numerical value of SDNN(standard deviation of all NN intervals) and SDSD(standard deviation of differences between adjacent NN intervals) items of HRV were showed significantly increased in all subjects after PMR. Conclusion : It indicated that PMR is efficient for inspiring resistance of the stress and a sense of stability, and PMR is a valuable method to reduce the mind stress and stiffness of body muscle.

• Journal of Korean Medicine Rehabilitation
• /
• v.18 no.1
• /
• pp.125-140
• /
• 2008

Objectives : The purpose of this study was to investigate the effect of Progressive Muscle Relaxation(PMR) on stress and muscle relaxation in healthy people. Methods : Sample group of 14 healthy subjects had been treated by progressive muscle relaxation for 10 days. Control group of 14 healthy subjects were not treated during the same period. Outcomes were assessed by Meridian-Electromyograph(MEMG), Heart Rate Variability(HRV), Stress Reaction Inventory(SRI). Results : The contraction and fatigue of erector spinae muscle by MEMG had decreased significantly in Sample group. There was no significant difference between two groups in the HRV and SRI. Conclusions : Further studies analysing PMR effect on stress and muscle relaxation are needed.

• Korean Journal of Veterinary Research
• /
• v.14 no.2
• /
• pp.207-210
• /
• 1974

Pharmacological investigation was performed in chickens which were pretreated with reserpine. Transmural stimulations were given to the isolated jejunum of chickens and studied the responses and the effects of dibenamine, propranolol, atropine and tetrodotoxin on them. The results obtained were summerized as follows: 1. Three different patterns of response were obtained from the isolated jejunum of non-treated chickens after giving them transmural stimulation. The first pattern was contraction followed by relaxation, the second pattern was contraction only and the third pattern was relaxation only. 2. The transmural stimulation of the jejunum preparations evoked relaxation while the periarterial stimulation evoked contraction in the reserpinized chick. 3. The relaxation response to the transmural stimulation was not affected by the pretreatment with dibenamine, propranolol and atropine. 4. The relaxation response to the transmural stimulation was abolished by tetrodotoxin. The results obtained in these studies indicate that the relaxation response to the transmural stimulation is due to non-adrenergic inhibitory fibers.

• Bulletin of the Korean Chemical Society
• /
• v.12 no.1
• /
• pp.47-51
• /
• 1991

Spin-lattice relaxation of methyl protons in 2,6-dichlorotoluene and N-methyl phthalimide, each dissolved in CDCl$_3$, has been studied at 34$^{\circ}$C and the contribution from spin-rotation interaction to the relaxation process has been separated from that due to dipole-dipole interactions among methyl protons. The results show that the spin-rotational contributions to the initial rate of relaxation in 2,6-dichlorotoluene and N-methyl phthalimide amount to 18 and 31%, respectively, of the total relaxation rate at 34$^{\circ}$C. The method of separating the spin-rotational contribution from that of dipolar interactions adopted in this paper is based on the well known fact that in an A$_3$ spin system such as methyl protons in liquid phase dipolar relaxation mechanism gives non-exponential decay of the z-component of total magnetization of protons while the random field fluctuation such as spin-rotational mechanism causes exponential decay.

• Korean Journal of Acupuncture
• /
• v.21 no.2
• /
• pp.161-176
• /
• 2004

Objectives : The purpose of this study was to investigate the effects of acupuncture stimulation and relaxation therapy on autonomic nervous system for students with examination stress by HRV, PSV and to find out relationship with anti-stress effect. Methods : The study group consists of 42 students were classified into three groups randomly : acupuncture stimulation group(male n=8, female n=6), relaxation therapy group(male n=8, female n=6) and rest group(male n=8, female n=6). Using heart rate variability and pupil size variability, we measured the value of HRT, SDNN, SDSD, LF norm, HF norm, LF/HF ratio, Pupil area, and compared the changes the sympathetic- parasympathetic activity. Measurement value were compared before and after, during midterm examination and normal times. Results : 1. HRT, LF/HF ratio, LF norm of acupuncture group was significantly decreased and HF norm were significantly increased in HRV after acupuncture stimulation at a term of examination. While variables of the other group were no significantly different. 2. SDNN of acupuncture group were significantly increased in HRV after acupuncture stimulation at normal times. 3. Pupil area, LF norm, HF norm of three group were no significantly different in PSV at a term of examination. 4. Pupil area of relaxation group were significantly decreased in PSV at normal times. While variables of the other group were no significantly different. 5. HRT of rest group were significantly decreased in HRV between three groups at a term of examination and normal times. 6. Pupil area of relaxation group were significantly decreased in PSV between three groups at a term of examination and normal times. Conclusion : The results suggest that acupuncture stimulation is associated with changed activity in the sympathetic and parasympathetic nervous system. Measurement values of HRV and PSV are suitable to estimate the activity of automatic nervous system.

• Korean Journal of Veterinary Research
• /
• v.37 no.1
• /
• pp.119-128
• /
• 1997

The relaxation of gastric fundus smooth muscles is the primary physiological event which induces the receptive relaxation of monogastric animals. L-arginine/Nitric oxide(L-arg/NO) system is known to mediate the inhibitory non-adrenergic non-cholinergic(NANC) neurotransmission in various tissues including gastrointestinal smooth muscles. The longitudinal smooth muscles of porcine gastric fundus showed fast relaxation during electrical field stimulation(EFS) and rebound contraction after EFS in NANC condition. So, the purpose of present study was elucidation of the neurotrasmitters related to the NANC relaxation and explanation of the relation between NANC relaxation and L-arg/NO system. The longitdinal smooth muscles of porcine gastric fundus were hung in the organ bath and under the presence of guanethidine($5{\times}10^{-5}M$), precontraction was induced by carbachol($1{\times}10^{-6}M$). The muscle responses to EFS and drugs were isomerically recorded. The rusults were summarized as follows. 1. The longtudinal muscles of porcine gastric fundus showed frequency-dependent relaxation and rebound contraction to electrical field stimulaton(1ms, 8V, 1~16Hz, 20sec, EFS). These responses were blocked by tetrodotoxin($1{\times}10^{-6}M$). 2. The relaxation and rebound contraction of the longitudinal muscles of porcine gastric fundus to EFS were inhibited by L-NAME($2{\times}10^{-5}M$). The inhibitory effect of L-NAME was antagonized by L-arginine($1{\times}10^{-3}M$), but not by D-arginine($1{\times}10^{-3}M$). 3. Exogenous NO($NaNO_2$, $1{\times}10^{-5}{\sim}1{\times}10^{-4}M$, pH=2.0) caused concentration-dependent relaxation as EFS did. 4. Methylene Blue($2{\times}10^{-5}M$), a soluble guanylate cyclase inhibitor, inhibited the relaxation and rebound contraction of the longitudinal muscles of porcine gastric fundus induced by EFS, but N-ethlmaleimide, a adenylate cyclase inhibitor, did not. 5. 8-Br-cGMP($1{\times}10^{-6}{\sim}3{\times}10^{-6}M$), permeable cGMP analogue, induced dose-dependent relaxation. but 8-Br-cAMP($1{\times}10^{-6}{\sim}3{\times}10^{-6}M$), permeable cAMP analogue, did not. Both did not evoked rebound contraction. 6. ${\alpha}$-chymotrypsin did not affect the relaxation of the longitudinal muscles of porcine gastric fundus. 7. Reactive blue 2($1{\times}10^{-4}M$, 40min) siginificantly inhibited the rebound contraction induced by EFS and inhibited contraction caused by exogenous ATP($1{\times}10^{-4}{\sim}1{\times}10^{-3}M$). These results suggests that NANC relaxation of the longitudinal muscles of porcine gastric fundus mainly mediated by NO and the rebound contraction is related to NO and other neurotransmitters.

• Journal of Institute of Convergence Technology
• /
• v.7 no.1
• /
• pp.7-10
• /
• 2017

In general, the shoe stretcher is utilized to stretching the leather of shoe upper in the longitudinal direction. In the capstone design class, we tried to make a shoe leather stretcher for the ball of foot. Since a natural cow leather was recovered in length according to relaxation time after stretched, it was difficult to predict the initial amount of set up of stretching. In this paper, tensile and relaxation experiments were conducted in order to predict the amount of initial stretching for appropriate tensile length. Apparatus of leather stretching was designed and strains of leather were measured according to relaxation times of 12, 18, 24 hours after stretching of 24 hours. It was revealed that the ratio of the final relaxed strain and the initial applied strain was about 0.404 with R-square of 0.990 for a shoe cow leather.