• Korean Journal of Applied Biomechanics
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• v.17 no.1
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• pp.111-119
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• 2007

The purpose of this study was to investigate muscle activity and gait pattern in lower limb depending on the outsole of heel rockers. Fifteen healthy men volunteered for this experiment. Each subject performed totally three trails with two pairs of different heel rocker shoes and a pair of normal running shoes at speed of 1.33m/s for 1 minute during walking on a treadmill. Kinematic data gathered in 100Hz was recorded and analyzed by using the 3D motion capture system to measure the trunk tilt and joint angle of the right lower limb. And the lower extremity muscle activities were simultaneously recorded in 1000Hz and assessed by using EMG. The statistical analysis was the one-way ANOVA with the repeated measures to compare among the three kinds of shoes. The level of statistical significance for all tests was 0.05. Joint angle of lower limb was showed statistically significant different in MST(hip joint), LHS(ankle joint), and RTO(knee and ankle joint). Muscle activity of rectus femoris and biceps femoris was statistically increased in both heel rocker shoes during gait cycle on treadmill. The maximum peak time of tibialis anterior in the negative heel rocker showed the delay of approximately 23.8%time than normal shoes. Gait pattern variability of the negative heel rocker was increased in the first half of the stance phase and the variability of the positive heel rocker was increased in the terminal stance phase. In Conclusion, stability was decreased in between joints of lower limb on positive heel rocker than negative heel rocker. This study found that there were different joint angle, muscle activity, gait pattern and coordinate system of the lower limb in each kind of shoes. These unstability affected the lower extremity and the whole body. A further study has to be continued with study of rehabilitation and exercise for a long-term.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.89-92
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• 2005

For the past years, wireless communications environment have developed with explosive demand of internet service and increase of subscriber. Anytime anywhere, we can access internet service and recently, we can access internet with portable terminal using wireless communications. So several schemes have been proposed for the efficient service. In this paper, we may improve performance of wibro system using adaptive antennas scheme at the base station (BS) and mobile station(MS),operating jointly. In wibro system, the joint use of transmit beamforming at BS and receive beamforming at MS is improved the SINR and increased the capacity compared to conventional system[1],[2].

• Molecules and Cells
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• v.41 no.1
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• pp.45-49
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• 2018

Autophagy is a lysosome-dependent degradation process that is essential for maintaining cellular homeostasis. In recent years, more studies have focused on the late stages of autophagy. Our group discovered and studied the terminal step of autophagy, namely autophagic lysosome reformation (ALR). ALR is the process that regenerates functional lysosomes from autolysosomes, thus maintaining lysosome homeostasis. ALR involves clathrin-mediated membrane budding from autolysosomes, elongation of membrane tubules along microtubules with the pulling force provided by the motor protein KIF5B, proto-lysosome scission by dynamin 2, and finally maturation of proto-lysosomes to functional lysosomes. In this review, we will summarize progress in unveiling the molecular mechanisms underlying ALR and its potential pathophysiological roles.

• Journal of the Korean Society for Railway
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• v.6 no.3
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• pp.179-185
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• 2003

This paper was to find out the design methodology for korean railway station of steel structure using by wooden structure system. Traditionally Korean architecture was made by wooden structure system what is called Gong-Po (wooden bracket structure system). The abundant ornament of Korean architecture is resulted from the composition rule of Gong-Po(wooden bracket structure system). But Korean wooden structural system have a limit in constructing large building, for example railway station, airport terminal, convention center etc. It is needed to convert wooden structure system into steel structure system. But there are many differences between wooden structure and steel structure in texture, material strength, joint system of elements etc. In this paper, we will show you how to make a joint system for steel structure of railway station and how to present the traditionality of Korean architecture in railway station.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.93-93
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• 2010

We developed friction welded bimetallic sleeve for 220kV aluminum conductor XLPE cable. Not only friction welded bimetallic sleeve for Termination(EB-A, EB-G) but also friction welded sleeve for Joint of Al to Cu conductor was developed regardless of this project. Generally, friction welded sleeve used to connect Al conductor cable to Cu conductor cable and used for improvement of mechanical property of terminal by offer the copper side of friction welded bimetallic sleeve at the Termination. Connection method for Al-Cu conductor has mainly used friction welding at the solid state, because it is difficult to connect by using conventional welding method. this investigation introduces development of friction welded bimetallic sleeve by friction welding and test result of 220kV Al conductor XLPE cable and accessories using friction welded sleeve.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.3
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• pp.1140-1155
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• 2021

Up to now, many state-of-arts have been proposed for two-way relaying system with linear modulations. The performances of antenna selection (AS) at both transmit and relay nodes need to be investigated in some two-way relaying multiple-input multiple-output (TWRM) systems. In this paper, the goal is focused on the study of nonlinear modulations, i.e., continuous phase modulation (CPM) in TWRM systems. Firstly, the joint phase trellis are simplified by reversed Rimoldi processing so as to reduce the systems' complexity. Then the performances of joint transmit and receive antenna selection (JTRAS) with CPM modulations in two-way relaying MIMO systems are analyzed. More exactly, the pair wise probability (PEP) is used to evaluate the error performance based on the CPM signal matrix, which is calculated in terms of Laurent expression. Since the channels subject to two terminal nodes share common antennas at relay node R in multiple-access scheme, we revise the JTRAS algorithm and compare it to existing algorithm via simulation. Finally, the error performances for various schemes of antenna selection are simulated and compared to the analysis in this paper.

• Korean Journal of Applied Biomechanics
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• v.26 no.2
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• pp.153-159
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• 2016

Objective: The purpose of this study was to investigate the effects of joint mobilization on foot pressure, ankle moment, and vertical ground reaction force in subjects with ankle instability. Method: Twenty male subjects (age, $25.38{\pm}3.62yr$; height, $170.92{\pm}5.41cm$; weight, $60.74{\pm}9.63kg$; body mass index (BMI), $19.20{\pm}1.67kg/m^2$) participated and underwent ankle joint mobilization. Weight-bearing distribution, ankle dorsi/plantar flexion moment, and vertical ground reaction force were measured using a GPS 400 and a VICON Motion System (Oxford, UK), and subsequently analyzed. SPSS 20.0 for Windows was used for data processing and paired t-tests were used to compare pre- and post-mobilization measurements. The significance level was set at ${\alpha}$ = .05. Results: The results indicated changes in weight-bearing, ankle dorsi/plantar flexion moment, and vertical ground reaction force. The findings showed changes in weight-bearing distribution on the left (pre $29.51{\pm}6.31kg$, post $29.57{\pm}5.02kg$) and right foot (pre $32.40{\pm}6.30kg$, post $31.18{\pm}5.47kg$). There were significant differences in dorsi/plantar flexion moment (p < .01), and there were significant increases in vertical ground reaction forces at initial stance (Fz1) and terminal stance (Fz2, p < .05). Additionally, there was a significant reduction in vertical ground reaction force at midstance (Fz2, p < .001). Conclusion: Joint mobilization appears to alter weight-bearing distribution in subjects with ankle instability, with resultant improvements in stability.

• Journal of Korea Port Economic Association
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• v.35 no.3
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• pp.1-18
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• 2019

The competition between port authorities (PAs) and terminal operating companies (TOCs) in providing port logistics services has gained importance. The PAs enter into leasing contracts with TOCs in various ways. This study aims to model a contract method that maximizes the joint profit between a PA and a TOC. Particularly, this study aims to model the equilibrium by comparing four types of contract schemes in the non-coordination, cooperation, Cournot, and collusion models. The results of the analysis show that the two-part tariff scheme generates a higher joint profit than the fixed and fee contracts. It is understood that risk- and profit-sharing between the PAs and TOCs helps the latter to maximize the throughput and the joint profit. These results are expected to provide an important theoretical basis for decision-making about port rent and freight between the PAs and TOCs.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.10
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• pp.948-956
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• 2010

The purpose of this study was to test the effectiveness of a prototype KAFO (Knee-Ankle-Foot Orthosis) powered by two artificial pneumatic muscles during walking. We had previously built powered AFO (Ankle-Foot Orthosis) and KO (Knee Orthosis) and used it effectively in studies on assistance of plantaflexion and knee extension motion. Extending the previous study to a KAFO presented additional challenges related to the assistance of gait motion for rehabilitation training. Five healthy males were performed gait motion on treadmill wearing KAFO equipped with artificial pneumatic muscles to power ankle plantaflexion and knee extension. Subjects walked on treadmill at 1.5 km/h under four conditions without extensive practice: 1) without wearing KAFO, 2) wearing KAFO with artificial muscles turned off, 3) wearing KAFO powered only in plantaflexion under feedforward control, and 4) wearing KAFO powered both in plantaflexion and knee extension under feedforward control. We collected surface electromyography, foot pressure and kinematics of ankle and knee joint. The experimental result showed that a muscular strength of wearing KAFO powered plnatarfexion and knee extension under feedforward control was measured to be lower due to pneumatic assistance and foot pressure of wearing KAFO powered plnatarfexion and knee extension under feedforward control was measured to be greater due to power assistance. In the result of motion analysis, the ankle angle of powered KAFO in terminal stance phase was found a peak value toward plantaflexion and there were difference of maximum knee flexion range among condition 2, 3 and 4 in mid-swing phase. The current orthosis design provided plantaflexion torque of ankle jonit in terminal stance phase and knee extension torque of knee joint in mid-swing phase.

• Journal of Korean Medicine Rehabilitation
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• v.29 no.2
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• pp.101-113
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• 2019

Objectives Bogol-tang has clinically been used to protect joint cartilage and to treat osteoarthritis. Our objective was to study the protective effect of Bogol-tang extract (BGT) in functional impairment, behavioral disorders, cartilage loss and pathological changes in a monoiodoacetate (MIA)-induced murine osteoarthritis (OA) model and interleukin (IL)-$1{\beta}$ -treated primary rat chondrocytes. Methods Mouse knee joints were injected with MIA, a chemical that inhibits glycolysis and causes joint inflammation and matrix loss. MIA-OA induced mice orally administered BGT or acetaminophen (AAP) for 18 days by daily. Primary rat chondrocytes were pretreated with BGT or dexamethasone (DEX) and followed by co-incubation with IL-$1{\beta}$ (10 ng/mL). Results In MIA-OA mice model, BGT led to delayed response on hot plate analysis, and suppressed the cartilage loss and damages in joint tissues. BGT suppressed the elevated levels of inflammatory mediators, nitrite and $PGE_2$, the gene expression of matrix degrading enzymes, and extracellular-signal-regulated kinases 1/2 and c-JunN-terminal kinase phosphorylation in IL-$1{\beta}$-treated primary rat chondrocytes. Conclusions Our results suggest that BGT improve the knee joint function and delay the cartilage damages by anti-nociceptive, anti-inflammatory and ant-catabolic effects, which indicate BGT could be a potential candidate for osteoarthritis treatment.