• Proceedings of the KSME Conference
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• 2008.11a
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• pp.882-887
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• 2008

In this paper, the dependency of energy efficiency on the walking/running pattern and the walking/running period is analyzed though simulations of walk, trot and gallop. A quadruped animal has its own original features in the walking pattern and the walking period for adaptation to the environment. The robot model used in the simulations has three active joints and one passive spring-loaded joint at each leg, which is based on the actual quadruped robot, HUNTER (Hanyang UNiversity TEtrapod Robot), developed in the lab. Also included is the dependency of energy efficiency on the walking period in trot.

• KDI Journal of Economic Policy
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• v.44 no.3
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• pp.75-99
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• 2022

This paper analyzes job creation when the Korean economy transitioned to a knowledge economy from the 1990s to the 2010s. During this period, the ratio of service to manufacturing jobs increased, knowledge intensive industries grew, and job creation became geographically concentrated around Seoul. The changes slowed down in the 2010s, and overall job growth weakened. To analyze the effect of job creation driver industries during this period, the main part of which are knowledge intensive tradable service industries, on local service job creation, I use a modified version of the local labor market of Moretti (2010). I analyze the job changes during 1995-2005 and during 2006-2016 in 237 Si-Gun-Gu areas in the Census on Establishments datasets. I find that one manufacturing job creates 0.5 local service jobs and that one tradable service job creates 1.1 jobs within Gu areas of metro cities and 2.3 jobs in Si-Gun areas. The job creation relationship between the tradable and local service sectors was not altered in this period. As more jobs were created in the tradable sector driven by the transition to a knowledge economy, job creation overall remained active, with the opposite also being true.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.1
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• pp.1-14
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• 2000

The purpose of this study was to evaluate the efficacy of adding autogenous bone to the toothash-plaster mixture in the healing process of bone. Full-thickness round osseous defects with the diameter of 20mm were made at the calvarial bone of adult dogs (n=19) bilaterally, which were thought to be critical size defect. The right defects were repaired with the toothash-plaster mixture plus autogenous bone (compressed volume 0.3cc) and the left defects with only toothash-plaster mixture. At 2-, 4-, 8-, 12- and 20- week after implantation, dogs were sacrificed and evaluated the osseous healing of bony defects clinically, radiographically, and microscopically. The results were as follows; 1. At the clinical observation, the wound healed very well without any problem except severe swelling in the early period after operation. Slight depression was recognized at the both sides when the portions of cranial defect were palpated. 2. There were statistically significant differences between toothash-plaster mixture groups and autogenous bone added groups at the same period, and among the groups in the bone density of the digital radiograms (P<0.001). There was a tendency that bone density was increasing with time. 3. In light microscopic examination, new bone formation was more active in the autogenous bone added groups than toothash-plaster mixture groups at the early period after implantation but there is little difference at 20-week after implantation. 4. In fluorescent microscopic examination, the fluorescent band could be observed at the area of active bone formation and the band was more distinct in the autogenous bone added groups then toothash-plaster mixture groups. 5. In transmitted electron microscopic examination, organelles such as rER, Golgi complex and secretory granule and osteoblast were observed. In summary higher volume ratio of autogenous bone is needed to improve the bone healing in that there is little difference between toothash-plaster mixture group and autogenous bone added group at the 20-week after implantation in spite of new bone formation was more active in the autogenous bone added groups than toothash-plaster mixture groups at the early period after operation.

• Advances in Traditional Medicine
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• v.6 no.3
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• pp.174-178
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• 2006

The ethanolic extract of Leucas aspera root was studied for its effect on the central nervous system (CNS) using pentobarbitone induced sleeping time test, the open field test and the hole cross test in Swiss albino mice. The present investigation revealed that the extract at the doses of 250 and 500 mg/kg, significantly prolonged the pentobarbitone induced sleeping time in mice though the onset of sleep was delayed as compared to control. In open field test the depressing effect was prominent from the second observation period (30 min) and persisted throughout the entire experimental period (240 min). In the hole cross test, the depressing effect was observed significant from the third observation period (60 min) and persisted up to the seventh observation period (240 min) except at fourth observation (90 min) for 250 mg dose group and depressing effect was significant from second observation (30 min) up to seventh observation period (240 min) for 500 mg dose group. These results support the finding that Leucas aspera root may contain biologically active constituent(s) having CNS activity.

• Advances in Traditional Medicine
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• v.4 no.4
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• pp.249-252
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• 2004

The methanol extract of Diospyros peregrina bark was studied for its effect on the central nervous system (CNS) using the pentobarbitone induced sleeping time test, the open field test and the hole cross test in Swiss albino mice. The present investigation revealed that the extract, at the doses of 250 and 500 mg/kg, significantly prolonged the pentobarbitone induced sleeping time in mice though the onset of sleep was delayed as compared to the control. In open field test, the depressing effect was prominent from the second observation period (30 min) and persisted throughout the entire experimental period (240 min). In the hole cross test, the depressing effect was observed from the second observation period (30 min) and persisted up to fifth observation period (120 min) for 250 mg dose group and up to sixth observation period (180 min) for 500 mg dose group. These results support the finding that D. peregrina bark extract at the above doses has CNS depressing effects and indicate that D. peregrina bark may contain biologically active constituent(s) having CNS depressant activity.

• Structural Engineering and Mechanics
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• v.33 no.1
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• pp.79-93
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• 2009

This paper investigates the possibility of controlling the response of typical portal frame structures to blast loading using a combination of semi-active and passive control devices. A one storey reinforced concrete portal frame is modelled using non-linear finite elements with each column discretised into multiple elements to capture the higher frequency modes of column vibration response that are typical features of blast responses. The model structure is subjected to blast loads of varying duration, magnitude and shape, and the critical aspects of the response are investigated over a range of structural periods in the form of blast load response spectra. It is found that the shape or length of the blast load is not a factor in the response, as long as the period is less than 25% of the fundamental structural period. Thus, blast load response can be expressed strictly as a function of the momentum applied to the structure by a blast load. The optimal device arrangements are found to be those that reduce the first peak of the structural displacement and also reduce the subsequent free vibration of the structure. Semi-active devices that do not increase base shear demands on the foundations in combination with a passive yielding tendon are found to provide the most effective control, particularly if base shear demand is an important consideration, as with older structures. The overall results are summarised as response spectra for eventual potential use within standard structural design paradigms.

• The Journal of Korean Physical Therapy
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• v.27 no.6
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• pp.407-412
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• 2015

Purpose: This study aimed to evaluate changes in the balance ability of patients whose head positions were altered due to stroke. Subjects were divided into three groups to determine the effects of the training on dynamic balance and gait. Methods: Forty-two stroke patients were enrolled. The Visual Feedback Training (VFT) group performed four sets of exercises per training session using a Sensoneck device, while the Active Range of Motion (ART) group performed eight sets per training session after receiving education from an experienced therapist. The Visual Feedback with Active Range of Motion (VAT) group performed four sets of active range of motion and two sets of visual-feedback training per session using a Sensoneck device. The training sessions were conducted three days a week for eight weeks. Results: The comparison of changes in dynamic balance ability showed that a significant difference in the total distance of the body center was found in the VFT group (p<0.05) and Significant differences were found according to the training period (p<0.05). The comparison of the 10 m walk test showed that the main effect test, treatment period and interactions between group had statistically significant differences between the three groups (p<0.05). Conclusion: Head-adjustment training using visual feedback can improve the balance ability and gait of stroke patients. These results show that coordination training between the eyes and head with visual feedback exercises can be used as a treatment approach to affect postural control through various activities involving the central nervous system.

• Structural Engineering and Mechanics
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• v.24 no.3
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• pp.375-393
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• 2006

Under high velocity, pulse type near source earthquakes semi-active control systems are very effective in reducing seismic response base isolated structures. Semi-active control systems can be classified as: 1) independently variable stiffness, 2) independently variable damping, and 3) combined variable stiffness and damping systems. Several researchers have studied the effectiveness of independently varying damping systems for seismic response reduction of base isolated structures. In this study effectiveness of a combined system consisting of a semi-active independently variable stiffness (SAIVS) device and a magnetorheological (MR) damper in reducing seismic response of base isolated structures is analytically investigated. The SAIVS device can vary the stiffness, and hence the period, of the isolation system; whereas, the MR damper enhances the energy dissipation characteristics of the isolation system. Two separate control algorithms, i.e., a nonlinear tangential stiffness moving average control algorithm for smooth switching of the SAIVS device and a Lyapunov based control algorithm for damping variation of MR damper, are developed. Single and multi degree of freedom systems consisting of sliding base isolation system and both the SAIVS device and MR damper are considered. Results are presented in the form of nonlinear response spectra, and effectiveness of combined variable stiffness and variable damping system in reducing seismic response of sliding base isolated structures is evaluated. It is shown that the combined variable stiffness and variable damping system leads to significant response reduction over cases with variable stiffness or variable damping systems acting independently, over a broad period range.

• The Korean Journal of Pain
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• v.35 no.2
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• pp.140-151
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• 2022

Background: Essential oils are of great interest for their analgesic and anti-inflammatory properties. We aimed to study the content of the essential oil of the Origanum vulgare of the Armenian highlands (OVA) in different periods of vegetation and to investigate its antinociceptive and anti-inflammatory effects in mice (in vivo) and cytotoxic action in cultured cells (in vitro). OVA essential oil was extracted from fresh plant material by hydro-distillation. Methods: For OVA essential oil contents determination the gas chromatography-mass spectrometry method was used. Formalin and hot plate tests and analysis of cell viability using the methyl-thiazolyl-tetrazolium (MTT) assay were used. Results: The maximal content of β-caryophyllene and β-caryophyllene oxide in OVA essential oil was revealed in the period of blossoming (8.18% and 13.36%, correspondently). In the formalin test, 4% OVA essential oil solution (3.5 mg/mouse) exerts significant antinociceptive and anti-inflammatory effects (P = 0.003). MTT assay shows approximately 60% cytotoxicity in HeLa and Vero cells for 2.0 µL/mL OVA essential oil in media. Conclusions: The wild oregano herb of Armenian highlands, harvested in the blossoming period, may be considered as a valuable source for developing pain-relieving preparations.

• 보존과학연구
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• s.35
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• pp.25-44
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• 2014

In this study, measured annual year and seasonal concentrations of VOCs by Active type and Passive type using the measurement and analysis method in the exhibition hall and outdoor. It was compared with the correlation between the methods according the comparison of methods to measured concentrations. As a results, the annual average concentrations of TVOC in exhibition room($906.5{\mu}g/m^3$) was greater than for most of the study period, more than 1.8 times the standard in the Ministry of Environment. ${\Sigma}VOCs$ concentration of exhibition room by Active type was higher than Passive type. Some VOCs was decreased with the lapse of time a temporary increase tendencies was. The annual average I/O ratio of TVOC was 9.0, ${\Sigma}VOCs$ was confirmed to occur in a large amount inside the exhibition hall ${\Sigma}VOCs$ was studied to 34.0. Correlation coefficient of ${\Sigma}VOCs$ was 0.367. Toluene was 0.567 that the survey was the largest analysis to the relationship between the two methods.