• ETRI Journal
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• v.17 no.3
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• pp.17-43
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• 1995

We present a comprehensive derivation of the transport of holes involving an interacting two-valence-band system in terms of a generalized relaxation time approach. We sole a pair of semiclassical Boltzmann equations in a general way first, and then employ the conventional relaxation time concept to simplify the results. For polar optical phonon scattering, we develop a simple method th compensate for the inherent deficiencies in the relaxation time concept and apply it to calculate effective relaxation times separately for each band. Also, formulas for scattering rates and momentum relaxation times for the two-band model are presented for all the major scattering mechanisms for p-type GaAs for simple, practical mobility calculations. Finally, in the newly proposed theoretical frame-work, first-principles calculations for the Hall mobility and Hall factor of p-type GaAs at room temperature are carried out with no adjustable parameters in order to obtain a direct comparison between the theory and recent available experimental results, which would stimulate further analysis toward better understanding of the complex transport properties of the valence band. The calculated Hall mobilities show a general agreement with our experimental data for carbon doped p-GaAs samples in a range of degenerate hole densities. The calculated Hall factors show $r_H$=1.25~1.75 over all hole densities($2{\times}10^{17}{\sim}1{\times}10^{20}cm^{-3}$ considered in the calculations.

• Journal of Physiology & Pathology in Korean Medicine
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• v.29 no.6
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• pp.485-491
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• 2015

This study was aimed to investigate the relaxation effects of Eucomiae Cortex (EC) extract in isolated rabbit corpus cavernosum smooth muscle and its mechanism. To evaluate the relaxation of EC extract in rabbit corpus cavernosum, EC extract was treated in corporal strips which were precontracted with phenylephrine(PE). To study its mechanism, Nω-nitro-L-arginine (L-NNA) was pretreated after infuse of EC extract and compared with non-treated. In calcium chloride (Ca²⁺) -free krebs solution, EC extract and Ca²⁺ 1 mM were infused by turns after Ca²⁺ 1 mM was treated into corporal strips contracted by PE. Cell ability, nitric oxide (NO) and epithelial nitric oxide synthase (eNOS) on human umbilical vein endothelial cell (HUVEC) were measured by MTT assay, Griess reagent system and histochemical, immunohistochemical methods. EC extract showed a significant relaxation effects on the corporal strips, this effects were inhibited by pretreatment of L-NNA. EC extract inhibited the increase of contraction by Ca²⁺ influx in Ca²⁺-free krebs solution, and eNOS positive reaction in corpus cavernosum, NO production in HUVEC increased by treatment of EC extract. These result suggest that the relaxation effects of EC extract in isolated corpus cavernosum smooth muscle are involved in increase of eNOS and NO production, blocking of extracellular Ca²⁺ influx.

• Smart Structures and Systems
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• v.11 no.1
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• pp.53-67
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• 2013

In this paper we apply Monte Carlo Filter to identifying dynamic parameters of structural systems and improve the efficiency of this algorithm. The algorithms using Monte Carlo Filter so far has not been practical to apply to structural identification for large scale structural systems because computation time increases exponentially as the degrees of freedom of the system increase. To overcome this problem, we developed a method being able to reduce number of particles which express possible structural response state vector. In MCF there are two steps which are the prediction and filtering processes. The idea is very simple. The prediction process remains intact but the filtering process is conducted at each node of structural system in the proposed method. We named this algorithm as relaxation Monte Carlo Filter (RMCF) and demonstrate its efficiency to identify large degree of freedom systems. Moreover to increase searching field and speed up convergence time of structural parameters we proposed an algorithm combining the Genetic Algorithm with RMCF and named GARMCF. Using shaking table test data of a model structure we also demonstrate the efficiency of proposed algorithm.

• Journal of the Korean Geosynthetics Society
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• v.16 no.4
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• pp.67-74
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• 2017

In order to prevent the ground subsidence accidents caused by the occurrence of underground cavity, it is necessary to evaluate the mechanical characteristics in the relaxation zone of the underground cavity. Also, the relaxation zone including underground cavity be appropriately reinforced. This paper described analysis results based on finite element method that was conducted to analyze the mechanism for occurrence of the relaxation zone around the underground cavity. The finite element analysis applied in forced displacement was carried out to simulate the underground cavity and relaxation zone, and then there were compared with previous research results. The analysis results showed that the void distribution of soil around the underground cavity has figured out. As a result, the area of the relaxation zone could be quantitatively presented by reduction characteristics of the shear stress.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.2
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• pp.169-177
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• 2014

This study aimed to investigate the relaxation effects and its underlying mechanisms of Epimedium koreanum Nakai(EK) in phenylephrine(PE) treated isolated rabbit corpus cavernosum smooth muscle. The dose-dependent relaxation responses of phenylephrine(PE, $1{\times}10^{-6}M$)-precontracted strips to EK at $0.01-3.0mg/m{\ell}$ were measured and also observed after endothelial denudation using organ bath. To analyze the underlying mechanisms of EK-induced relaxation, $N{\omega}$-nitro-L-arginine(L-NNA), methylene blue(MB), tetraethylammonium chloride(TEA), indomethacin(IM) were pretreated before EK extract infused into precontracted strips induced by PE. To investigate cytotoxic activity and nitric oxide(NO) concentration of EK extract on EA.hy926 cells, mitochondrial dehydrogenase activity(MTT) assay and nitric oxide detection kit were used. The cavernous strips were significantly relaxed by EK extract at $0.3mg/m{\ell}$, $1.0mg/m{\ell}$, $3.0mg/m{\ell}$ and the relaxation responses of PE-precontracted strips denuded endothelium also inhibited in comparison with intact endothelium. The pretreatment of L-NNA, MB, TEA reduced EK extract-induced endothelium-dependent relaxation, but the pretreatment of IM didn't affect EK extract-induced endothelium-dependent relaxation. When EK extract was applicated on EA.hy926 cells, the NO concentration was increased. Our findings have shown that EK extract exerts a relaxing effect on corpus cavernosum in part by suppressing influx of extracellular $Ca^{2+}$ through activating the NO-cGMP system.

• Proceedings of the Korean Vacuum Society Conference
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• 2007.02a
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• pp.116-116
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• 2007

• Science of Emotion and Sensibility
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• v.6 no.2
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• pp.21-28
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• 2003

Tn the present study, 9 photographs from the International Affective Picture System (IAPS) judged to express best 2-dimensional sensibility were selected and used to stimulate the subjects. The goal of the study lay in verifying whether or not the consequent affective changes in the subjects can be discriminated psychologically and physiologically in terms of arousal and relaxation. In order to determine affective changes, the physiological signals of the subjects' autonomic nervous system were measured through electrocardiogram (ECG) , galvanic skin response (GSR), skin temperature, and respiration. After stimulation and measurement, subjective evaluation was conducted. Subjective evaluation revealed that affective arousal level could be classified into 4 consecutive stages: arousal 〉 unpleasant arousal, pleasant arousal 〉 comfort 〉 relaxation. Analysis revealed that the responses of the autonomic nervous system, too, could be classified into 3 consecutive stages: arousal, unpleasant arousal, pleasant arousal 〉 comfort 〉 relaxation. By selecting and using 9 photographs from the IAPS deemed best to express Koreans'2-dimensional sensibility, the present study confirmed that it is possible to discriminate changes in the subjects' affective arousal level in terms of arousal and relaxation through psychological and physiological evaluation.

• Journal of the Ergonomics Society of Korea
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• v.21 no.3
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• pp.35-46
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• 2002

In this study, emotion changes were induced by four imaginations- pleasantness, unpleasantness, arousal, relaxation and it was examined using subjective evaluation and analysis of the physiological signals of the central and autonomic nerve systems whether the intended emotions were appropriately achieved, and whether these emotion changes could be distinguished from the analysis of physiological signals. Each of the four imaginations was implemented on 32 subjects for 30 seconds, while that Electroencephalogram (EEG), Eelectrocardiogram (RSP) were measured, and a subjective evaluation was implemented following the completion of the measurement. The analysis of the subjective evaluation revealed that the subjects underwent the four clearly differentiated imaginations, and the pleasantness level was classified into four imagination stages, pleasantness>relaxation>arousal=comfort>unpleasantness, and arousal level was classified into four imagination stages in the order of arousal>unpleasantness${\approx}$pleasantness>comfort>relaxation. The analysis of the EEG revealed that three stages of pleasantness level, pleasantness>relaxation=arousal=comfort>unpleasantness were classified from the values of ${\alpha}/{\alpha}+{\beta}\;and\;{\beta}/{\alpha}+{\beta}$, and about tour distinguishable stages of arousal level were obtained from the autonomic nervous system responses following the order of arousal>unpleasantness${\approx}$pleasantness> comfort> relaxation. It was found that intended emotion could be induced from the imagination, and these induced emotion changes could be differentiated using the physiological signals of the EEG and autonomic nervous system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.1
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• pp.103-108
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• 2012

In this paper, the optimal design of a spring-type gravity compensation system for an articulated robot is presented. Sequential quadratic programming (SQP) is adopted to resolve various nonlinear constraints in spring design such as stress, buckling, and fatigue constraints, and to reduce computation time. In addition, continuous relaxation method is used to explain the integer-valued design variables. The simulation results show that the gravity compensation system designed by proposed method improves the performance effectively without additional weight gain in the main workspace.

• Journal of International Academy of Physical Therapy Research
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• v.11 no.4
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• pp.2237-2243
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• 2020

Background: The myofascial release technique is known to be an effective technique for increasing posterior fascia flexibility in short hamstring syndrome (SHS) subjects. But therapeutic mechanism of myofascial relaxation remains unclear. Recently, the theory of autonomic nervous system domination has been raised, however, a proper study to test the theory has not been conducted. Objectives: To investigate whether the application of the myofascial release technique can induce changes in the autonomic nervous system and affect the secretion of stress hormones and myofascial relaxation. Design: Quasi-experimental study. Methods: Twenty-four subjects with SHS were randomly divided into two groups. In the experimental group, the suboccipital muscle inhibition (SMI) technique was applied to the subjects for 4 min in supine position, and in the control group, the subjects were lying in the supine position only. A forward flexion distance (FFD) was conducted, blood pressure, heart rate, and cortisol levels were measured before and after the intervention and 30 min after intervention to determine myofascial relaxation and stress hormone levels. The evaluation was conducted separately in blind by an evaluator. Results: A FFD decreased in the experimental group, no change in cortisol was observed. On the contrary, a decrease in cortisol appeared in the control group after 30 minutes. Conclusion: The myofascial release technique is an effective treatment to increase the range of motion through posterior superior myofascial chain, but there is no evidence that myofascial release technique can control the autonomic nervous system.