• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.4
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• pp.918-929
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• 2008

This study investigated the effects of inverted position on EEG and heart rate variability before and after Bang song gong. BSG is a training method using in qi-gong and meditation to give a convergence of consciousness on body segments in order and take a silent speech of 'song'. The subjects were the 14 university students(n=7 per group) who had not experienced any medical problem and had not practiced BSG. They took a practice of the two way of BSG training program for 30 minutes every other day for two weeks. During practicing BSG, A group took sitting position and lean sitting position by turns, B group took inverted and lean sitting position in the same way. Statistical analysis conducted by two-way ANOVA($2groups^{\ast}2periods$) with p<0.05 for average difference of EEG and HR according to position change in each group before and after BSG. In A group, EEG and HR were changeless irrespective of the change of position and BSG. On the other hand, in B group, significant changes were observed in EEG(p<0.05). ${\alpha}$ wave of inverted position were on the increase, ${\beta}$ and ${\delta}$ wave of inverted position showed smaller power after two weeks training. In the variation of HR, there were smaller variation according to the position change after BSG compared to before BSG(p<0.05). The results suggested that an inverted position may make the depth of meditation deeper, and is likely to be effective for decreasing tension of brain and the sleepiness during qi-gong training. In addition to, an inverted position seemed to promote control of blood pressure of brain. So the application of an inverted position to 'BSG' will be very helpful to achieve deeper relaxation and to obtain the desired effect from qi-gong training.

• Korean Journal of Cleft Lip And Palate
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• v.10 no.2
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• pp.75-80
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• 2007

For the treatment of cleft palate patients, orthognathic surgery has been used by standard protocol. Predictable results have been achieved with standard techniques in slight to moderate maxillary hypoplasia. However, limited advancement and high relapse rate was reported in severe cases. The purpose of the present study was to review the clinical results of distraction osteogenesis in the patients with cleft lip and palate. Distraction osteogenesis has improved results in these patients by allowing soft tissue relaxation and gradual bone generation. Therefore, greater movement of the craniofacial skeleton is possible in severe cases of maxillary retrusion with lower relapse rates. In conclusion, distraction osteogenesis for the advancement of hypoplastic maxilla of cleft patients has shown successful treatment method.

• Journal of Environmental Science International
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• v.19 no.8
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• pp.1057-1066
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• 2010

An ecological learning center is defined as a place which can establish the correct relationship between human and environment. Human can learn ecosystem and importance of environment throughout observation of nature and participation in program of ecological learning center. The most important aspects of ecological learning center planning are to reflect on user's demand and preservation of ecosystem. The prime goals of this study is to analyze user's characteristics in the Young Wheol Mulmurigol Ecological Learning Center. The second goal of this study is to find out the satisfaction model based on user's perceived performance of each program and facility in the center. For this study, questionnaire survey with 204 individuals was completed. The data from the questionnaire were analyzed statistical method by SPSS. There are several significant results from the study as following First, this ecological learning center as a newly operating facility is used not for educational purpose but for resting and relaxation purpose. It is due to that the most of users in this center are package tourists with historic scenes. Second, user's perceived performance evaluated by 23 attributions of programs and facilities, and these attributions could be classified by 5 factors such as environment friendly design, educational function, preservation of environment, provision of various bio-top and provision of resting area. Third, the user satisfaction model indicates that user satisfaction is depended on various factors such as preservation of environment, provision of various bio-top, provision of resting area. Among these factor affecting the satisfaction, provision of various bio-top is the most influence on user satisfaction.

• Geomechanics and Engineering
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• v.11 no.3
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• pp.401-420
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• 2016

The stability of deep coal roadways with large sections and thick top coal is a typical challenge in many coal mines in China. The innovative Universal Discrete Element Code (UDEC) trigon block is adopted to create a numerical model based on a case study at the Dongtan coal mine in China to better understand the failure mechanism and stability control mechanism of this kind of roadway. The failure process of an unsupported roadway is simulated, and the results suggest that the deformation of the roof is more serious than that of the sides and floor, especially in the center of the roof. The radial stress that is released is more intense than the tangential stress, while a large zone of relaxation appears around the roadway. The failure process begins from partial failure at roadway corners, and then propagates deeper into the roof and sides, finally resulting in large deformation in the roadway. A combined support system is proposed to support roadways based on an analysis of the simulation results. The numerical simulation and field monitoring suggest that the availability of this support method is feasible both in theory and practice, which can provide helpful references for research on the failure mechanisms and scientific support designing of engineering in deep coal mines.

• Structural Engineering and Mechanics
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• v.53 no.3
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• pp.481-495
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• 2015

Many hydropower stations in southwest China are located in regions of brittle rock mass with high geo-stresses. Under these conditions deep fractured zones often occur in the sidewalls of the underground caverns of a power station. The theory and methods of fracture and damage mechanics are therefore adopted to study the phenomena. First a flexibility matrix is developed to describe initial geometric imperfections of a jointed rock mass. This model takes into account the area and orientation of the fractured surfaces of multiple joint sets, as well as spacing and density of joints. Using the assumption of the equivalent strain principle, a damage constitutive model is established based on the brittle fracture criterion. In addition the theory of fracture mechanics is applied to analyze the occurrence of secondary cracks during a cavern excavation. The failure criterion, for rock bridge coalescence and the damage evolution equation, has been derived and a new sub-program integrated into the FLAC-3D software. The model has then been applied to the stability analysis of an underground cavern group of a hydropower station in Sichuan province, China. The results of this method are compared with those obtained by using a conventional elasto-plastic model and splitting depth calculated by the splitting failure criterion proposed in a previous study. The results are also compared with the depth of the relaxation and fracture zone in the surrounding rock measured by field monitoring. The distribution of the splitting zone obtained both by the proposed model and by the field monitoring measurements are consistent to the validity of the theory developed herein.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.05a
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• pp.281-286
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• 2005

This paper presents sensitivity analysis of generalized rapid relaxation inversion (GRRI) algorithm for inverting controlled-source audio-frequency magnetotelluric (CSAMT) data. The algorithm was originally developed by modifying the RRI algorithm to recover a two-dimensional (2-D) conductivity structure of the Earth from MT data, but can be extended to include CSAMT data if it is combined with 2.5-D forward modeling. These GRRI approximate sensitivities are validated by comparison with exact 1-D and 2.5-D sensitivities. The comparison shows that the GRRI sensitivity is a good approximation to the exact sensitivity and has about half magnitude of the RRI sensitivity. Although the magnitude of the GRRI sensitivity is still slightly larger than that of the 2.5-D sensitivity, both sensitivities are broadly similar in shape when source-receiver offsets are greater than one skin depth on the Earth.

• Journal of Ginseng Research
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• v.21 no.2
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• pp.119-124
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• 1997

Chronic hypertension is associated with impaired endothelial function such as reduced synthesis/release of endothelium-derived relaxing factor(EDRF, nitric oxide) and increased synthesis/release of endothelium-derived contracting factor(EDCF) including prostaglandin endoperoxide($PGH_2$) , superoxide anion both in animals and in humans. We have previously shown that ginsenosides lower the blood pressure and enhance the release of nitric oxide(NO) from endothelial cells in the rat aorta of the normotensive rats. The aim of the present study is to examine whether in vivo treatment of spontaneously hypertensive rats(SHRs) with protopanaxatriol ginsenosides(PPT) reduces the blood pressure and improves endothelial function in the isolated thoracic aorta of SHR. In addition, the contractile response to $PGH_2$ and superoxide anion in the aorta treated with PPT was assessed. SHRs at the age of 16 weeks were savaged with PPT(30 mg/kg/ day) for 2 weeks and systolic blood pressure was measured by the tail-cuff method. Whereas blood pressure was significantly increased in SHRs by 5.4 mmHg during this period of treatment, treatment of SHRs with PPT blocked the elevation of blood pressure. Endothelium-dependent relaxation to acetylcholine was significantly increased in the PPT-treated animals. $PGH_2$- and oxygen-derived free radical-induced contractions were significantly suppressed in aortic rings without endothelium from PPT-treated SHR. These findings indicate that PPT reduces the blood pressure of SHR, which may be associated with either increase of NO release or by antagonizing superoxide anion and PGH2 in the aortic smooth muscle.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.4
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• pp.1-7
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• 2019

The customer of massage chair is expanding day by day from middle age to all ages. In 2018, the market size was 700 billion KRW, an increase of 30 times over 10 years. However, most related SMEs suffer from excessive competition by the market monopoly of some major companies. In this situation, in order for a related company to survive, it is necessary to steadily research and develop new products. Founded in 2009, company L produces massage chairs for health and relaxation of customers. L's products use a sound wave vibration module that is favorable for human body, unlike other products that use vibration motor type. However, frequent breakdowns of massage chair due to the vulnerability of plate (leaf) springs, which play an important role in sound wave vibration modules, made sap its competitiveness. In this paper, we propose a method to design desirable plate spring structure by sequentially experimenting with five different plate springs. The results of this study are expected to contribute to improve the quality of plate spring and the reliability of sound wave vibration module. In the future, it is necessary to find a way to use it in the development of foot massage or scalp management device as well as continuous research to find optimal plate spring structure through various analysis.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.8 no.2
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• pp.57-71
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• 2002

Cervical pain is a rapid increase that is owing to a flexion-extension whiplash injury, unappropriated posture, chronical repetition injury from abdominal position of head and neck, excessive repeating work, chronical deficiency of excercise. Because of that is bring about muscle unbalance, tightness of cervical extensor muscle, weakness of cervical deep flexor muscles, instability of cervical region and reduction of proprioceptive sensor. Recent the role of muscle is more emphasized for preservation of sine stabilization. And cognition of integrated muscular system, importance for the operation and relation is increased to maintain stability of the motor system and pertinent function. Therefore we are going to introduce the sling exercise and stabilization exercise method for advanced efficient of cervical and upper limb and for the muscle strengthening to importance cervical stabilization through neurological program as control the reaction of cervical stabilization. Sling exercise therapy(SET) concept consists of a system of diagnosis and treatment. The system of diagnosis involves testing the muscle's tolerance through progressive loading in open and close kinetic chains. The SET system contains elements such as relaxation, increasing the range of movement, traction, training the stabilizing musculature, sensory-motor exercises, training in open and close kinetic chains, dynamic training of the mobilizing musculature, cardiovascular exercise, group exercise, personal exercise at home Sensory-motor training is an essential element of the SET concept. The emphasis is on closed kinetic chain exercise on an unstable surface, there by achieving optimum stimulation of the sensory-motor apparatus.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.12
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• pp.68-74
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• 2010

A sub-${\mu}$W CMOS Wien-Bridge oscillator for ultra low power (ULP) radio applications is presented. The Wien-Bridge oscillator is based on an non-inverting opamp amplifier with a closed-loop gain $1+R_2/R_1$ as a means of providing necessary loop gain. An additional RC network provides appropriate phase shift for satisfying the Barkhausen oscillation condition at the given frequency of 1/($2{\pi}RC$). In this design, we propose a novel loop gain control method based on a variable capacitor network instead of a rather conventional variable resistor network. Implemented in $0.18{\mu}m$ CMOS, the oscillator consumes only 560 nA at the oscillation frequency of 22 kHz.