• Journal of Urban Science
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• v.7 no.1
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• pp.55-61
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• 2018

Long bridges, such as suspension bridges and diagonal bridges, are complex phenomena that show different behaviors depending on the shape and rigidity of the cross sections, such as wind vibrations and liquid vibrations from earthquakes in liquid storage containers. This is called the lower skirt on the lower side of the bridge, and the installation of lower skirt is effective for release and vortex vibrations caused by rapid winds, and that increases the stability of the wind resistance of the bridge. Optimal shape and installation of the lower skirt is also essential to make maximum wind speed effect of the lower skirt. Therefore, this study proposes a numerical analysis method to control the vibration of a bridge by calculating the optimal installation angle of an optimal lower skirt according to the optimal control theory and this study evaluates the impact on the optimal control system by minimizing the dominance equation with an evaluation function,which is an indicator for evaluating the optimal control theory state.

• Journal of the Institute of Convergence Signal Processing
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• v.18 no.1
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• pp.1-5
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• 2017

It is important to train lower limb muscle strength using a tilting table to recover the lower extremity function of hemiplegia patients. It is known that the foot deformity and poor posture of hemiplegia patients can reduce the effectiveness of lower limb rehabilitation training. In this study, we developed a sensor system that can measure the foot pressure distribution of the patients for the load control of the lower extremity during lower limb rehabilitation training and it can be substituted for conventional high-cost technologies.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1638-1641
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• 2004

Many walking stands, and assisting tools have been developed for the people with low-limb disability to prevent diseases from bedridden state and to help them walk again. But many of those equipments require user to have some physical strength or balancing ability. In our last research, we developed walking assist system for the people with lower-limb disability. With the system, user can be assisted by actuators, and do not have to worry about falling down. The system adapted the unique closed links structure with four servomotors, three PICs as controller, and four limit switches as HMI (human man interface). We confirmed the adaptability of the system by the experiment. In this research, Muscle Stiffness Sensor was tested as the advanced HMI for walking assist system, and confirmed the adaptability by the experiment. As Muscle Stiffness Sensor can attain the muscle activity, user can interface with any device he want to control. Experimental result with Muscle Stiffness sonsor showed that user could easily control the walking assist system as his will, just by changing his muscle strength.

• Journal of Internet Computing and Services
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• v.14 no.6
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• pp.33-39
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• 2013

When the eldery with limited mobility and disabled use a wheelchairs to move, it can cause decreased exercise ability like decline muscular strength in upper limb and lower extremities. The disabled people suffers with spinal cord injuries or post stroke hemiplegia are easily exposed to secondary problems due to limited mobility. In this paper, We designed intelligent wheelchair robot system for upper limb and lower extremities exercise/rehabilitation considering the characteristics of these severely disabled person. The system consists of an electric wheelchair, biometrics module for Identification characteristics of users, upper limb and lower extremities rehabilitation. In this paper, describes the design and configurations and of developed robot. Also, In order to verify the system function, conduct performance evaluation targeting non-disabled about risk context analysis with biomedical signal change and upper limb and lower extremities rehabilitation over wheelchair robot move. Consequently, it indicate sufficient tracking performance for rehabilitation as at about 86.7% average accuracy for risk context analysis and upper limb angle of 2.5 and lower extremities angle of 2.3 degrees maximum error range of joint angle.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.9 no.4
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• pp.331-337
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• 2015

This research was to develop the cycling system of lower limbs for rehabilitation during cycle exercise in supine position. Also we analyzed the muscular activity of lower-limbs at various exercise conditions according to exercise mode, load, velocity. 42 healthy subjects(ages 20-60 years) were participated. We measured the muscular activities of right lower limb muscle in rectus femoris, biceps femoris, tibialis anterior, medial gastrocnemius, soleus. Results, medial gastrocnemius shows high value on load 10 stage than load 1 and 5 stage. And all muscular activity except medial gastrocnemius was decreased as increase of velocity. We have found that there is a difference of lower limbs activity depending on exercise mode and method. This study could be applied to reference data to develop cycle system of lower limbs for rehabilitation.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.1
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• pp.10-17
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• 1999

The purpose of this study is to investigate the baroclinic response of the upper-layer of two-layered fluid when the lower-layer motion is driven by pumping an external fluid into the lower-layer or by pumping out the lower-layer fluid. Recent observations of the barotropic nature of deep water movements in the East Sea (fakematsu et al., 1994; KORDI, 1997) may suggest a possibility of interaction between the upper and lower layer via interface tilting. For homogeneous fluid, steady and axisymmetric source or sink causes axisymmetric geostrophic flow, and the lower-layer motion in two-layered fluid was similar to homogeneous flow. But as Rossby number (${\varepsilon}$) or internal Froude number ($f_2$) increases, the lower-layer motion was affected by the interface tilting. The interface tilting calculated based on the observed azimuthal velocities of upper- and lower-layers becomes greater as $f_2$ increases. In other words, the increase of the $f_2$ changes the barotropic system to baroclinic system.

• Journal of Biosystems Engineering
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• v.39 no.1
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• pp.34-38
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• 2014

Purpose: In this study, the performance of cooling system with the water-water heat pump system of 100kW scale made for cooling agricultural facilities, especially for horticultural facilities, was analyzed. It was intended to suggest performance criteria and performance improvement for the effective cooling system. Methods: The measuring instruments consisted of two flow meters, a power meter and thermocouples. An ultrasonic and a magnetic flow meter measured the flow rate of the water, which was equivalent to heat transfer fluid. The power meter measured electric power in kW consumed by the heat pump system. T-type thermocouples measured the temperature of each part of the heat pump system. All of measuring instruments were connected to the recorder to store all the data. Results: When the water temperature supplied into the evaporator of the heat pump system was over $20^{\circ}C$, the cooling Coefficient Of Performance(COP) of the system was higher than 3.0. As the water temperature supplied into the evaporator, gradually, lowered, the cooling COP, also, decreased, linearly. Especially, when the water temperature supplied into the evaporator was lower than $15^{\circ}C$, the cooling COP was lower below 2.5. Conclusions: In order to maintain the cooling COP higher than 3.0, we suggest that the water temperature supplied into evaporator from the thermal storage tank should be maintained above $20^{\circ}C$. Also, stratification in the thermal storage tank should be formed well and the circulating pumps and the pipe lines should be arranged in order for the relative low-temperature water to be stored in the lower part of the thermal storage tank.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.3
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• pp.346-353
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• 2012

The purpose of this study is to verify the energy efficiency of the integrated system combining human and a lower extremity exoskeleton robot when it is applied to the proposed gait pattern. Energy efficient gait pattern of the lower limb was proposed through leg function distribution during stance phase and the dynamic-manipulability ellipsoid (DME). To verify the feasibility and effect of the redefined gait trajectory, simulations and experiments were conducted under the conditions of walking on level ground and ascending and descending from a staircase. Experiments to calculate the metabolic cost of the human body with or without the assistance of the exoskeleton were conducted. The energy consumption of the lower extremity exoskeleton was assessed, with the aim of improving the efficiency of the integrated system.

• Food Science of Animal Resources
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• v.40 no.2
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• pp.286-296
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• 2020

This study investigates the utilization of an electric-field-induced super cooling system in long-term dry aging of beef loin. Analyzed quality properties of dry-aged beef loin applied with electric field refrigeration (EFR) versus commercial refrigeration (CR). Quality properties was including aging loss, pH, water holding capacity (WHC), cooking loss, color, warner-bractzler shear force (WBSF), total plate count (TPC), and thiobarbituric acid reactive substances (TBARS). Aging loss of wk 1 EFR was significantly lower than CR (p<0.05). pH of EFR was slow change tendency compared CR. WHC of both aging methods were higher with increase in aging duration. Cooking loss of wk 1, 2, 4, and 10 EFR were significantly lower than CR (p<0.05). Lightness and redness of EFR was slow change tendency compared CR. However, yellowness of EFR was increased until wk 2, 3, and significantly decreased at wk 10 (p<0.05), but yellowness of CR was decreased until wk 3 and significantly increased with an increasing aging weeks (p<0.05). Both aging methods of WBSF was decreased with increase in aging weeks; however, wk 10 of CR was significantly lower than EFR (p<0.05). TPC after wk 3 EFR groups were significantly lower than CR groups (p<0.05), and TBARS of EFR groups were significantly lower than CR (p<0.05). The present results show that application of the EFR system for dry aging beef loin can extends its shelf life and induce changes of several aging properties in similar to commercial aging.

• Archives of Plastic Surgery
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• v.36 no.6
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• pp.702-706
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• 2009

Purpose: Analysis of lower nose and upper lip asymmetry in patients with unilateral cleft lip nose deformity has been proceeded through direct measurement and photo analysis. But there are limitation in presenting real image because of its 2 dimensional trait. The authors analyzed such an asymmetry using 3D VECTRA system (Canfield, NJ, USA) in quantitative way. Methods: In 25 Patients with unilateral cleft lip nose deformity(male 12, female 13, age ranging from 4 to 19), patients with right side deformity were 10 and left were 15. Analysis of asymmetry was proceeded through 3D VECTRA system. After taking 3 dimensional photo, alar area, upper lip area, nostril perimeter, nostril area, Cupid's bow length, nostril height and nostril width were measured. Correlation coefficient and inter data quotients were calculated. Results: In nostril perimeter, maximal difference of cleft side and non - cleft side was 39.3%, asymmetric quotient Qasy = Qcl/Qncl(Qcl, value of cleft side; Qncl, value of non - cleft side) was ranged from 0.84 to 1.85 and in seven cases the length of cleft side was smaller. In nostril area, maximal difference was 69.6% and in 13 cases cleft side was smaller. In lower nasal area, maximal difference was 37.2% asymmetric quotient Qasy = Qcl/Qncl was ranged from 0.47 to 2.03 and in 20 cases cleft side was smaller. The correlation coefficients of nostril perimeter and area were 0.8345. Conclusion: Using 3D VECTRA system, the authors can measure nostril perimeter and lower nasal area that could not been measured with previous methods. Asymmetry of midface was analyzed through area comparison in quantitative way. Futhermore, post operative change can be measured in quantitative method.