• Smart Structures and Systems
• /
• v.20 no.2
• /
• pp.127-137
• /
• 2017

Identification of damping characteristics is of significant importance for dynamic response analysis and condition assessment of structural systems. Damping is associated with the behavior of the energy dissipation mechanism. Identification of damping ratios based on the sensitivity of dynamic responses and the model updating technique is investigated with numerical and experimental investigations. The effectiveness and performance of using the sensitivity-based model updating method and vibration monitoring data for damping ratios identification are investigated. Numerical studies on a three-dimensional truss bridge model are conducted to verify the effectiveness of the proposed approach. Measurement noise effect and the initial finite element modelling errors are considered. The results demonstrate that the damping ratio identification with the proposed approach is not sensitive to the noise effect but could be affected significantly by the modelling errors. Experimental studies on a steel planar frame structure are conducted. The robustness and performance of the proposed damping identification approach are investigated with real measured vibration data. The results demonstrate that the proposed approach has a decent and reliable performance to identify the damping ratios.

• Journal of Fashion Business
• /
• v.26 no.2
• /
• pp.143-155
• /
• 2022

The purpose of this study was to develop protective clothing that could alleviate fall impacts. Fall impact protection pants for elderly women were designed, and motion adaptable hip pads and knee pads printed by 3D printing were integrated into the pants and evaluated. First, the design of the fall impact protection pants with variable motion was semi-loose fitting pants that could be worn and detached from the protective pad. A pad pocket was made in the lining inside the pants so that the protective pad could be fixed to the protective area. Second, in the evaluation of the appearance of the fall impact protection pants, the wearer group had a good score of 4.60 or higher for all questions on color, material, ease, and fit. In the evaluation of the insertion method of the protective pad, the flexibility of the pad, and the weight of the pad, the subjects' scores were 4.30~4.80. The fit of the fall impact protection pants was excellent in the texture and elasticity of the outside and inside of the pants. There was no discomfort due to the pad(4.60), and no difficulty in movement during wearing activities was reported. During squatting, it was evaluated as 4.80, indicating that the motion adaptable hip joint and knee pads were highly effective during operation.

• Geomechanics and Engineering
• /
• v.28 no.2
• /
• pp.181-195
• /
• 2022

Roughness and joint inclination angle are the important factors that affect the strength and deformation characteristics of jointed rock mass. In this paper, 3D printer has been employed to make molds firstly, and casting the jointed specimens with different joint roughness coefficient (JRC), and different joint inclination angle (α). Conventional triaxial compression tests were carried out on the jointed specimens, and the influence of JRC on the strength and deformation parameters was analyzed. At the same time, acoustic emission (AE) testing system has been adopted to reveal the AE characteristic of the jointed specimens in the process of triaxial compression. Finally, the morphological of the joint surface was observed by digital three-dimensional video microscopy system, and the relationship between the peak strength and JRC under different confining pressures has been discussed. The results indicate that the existence of joint results in a significant reduction in the strength of the joint specimen, JRC also has great influence on the morphology, quantity and spatial distribution characteristics of cracks. With the increase of JRC, the triaxial compressive strength increase, and the specimen will change from brittle failure to ductile failure.

• Wind and Structures
• /
• v.30 no.4
• /
• pp.405-421
• /
• 2020

Quayside container cranes are important delivery machineries located in the most frontiers of container terminals, where strong wind attacks happen occasionally. Since the previous researches on quayside container cranes mainly focused on the mean wind load and static response characteristics, the fluctuating wind load and dynamic response characteristics require further investigations. In the present study, the aerodynamic wind loads on quayside container cranes were obtained from wind tunnel tests. The probabilistic and spectral models of the fluctuating aerodynamic loads were established. Then the joint probabilistic distributions of dynamic wind-induced responses were derived theoretically based on a series of Gaussian and independent assumption of resonant components. Finally, the results were validated by time domain analysis using wind tunnel data. It is concluded that the assumptions are acceptable. And the presented approach can estimate peak dynamic sliding force, overturning moments and leg uplifts of quayside container cranes effectively and efficiently.

• Journal of muscle and joint health
• /
• v.19 no.2
• /
• pp.107-119
• /
• 2012

Purpose: This study was conducted to extract international classification of functioning, disability, and health (ICF) core sets for measuring functional status in acute stroke patients, and to evaluate clinical applicability of the core sets. Methods: A set of 22 ICF items on functional status in acute stroke patients were extracted from the Korean general ICF core sets and ICF core sets for stroke patients. The extracted ICF functional items were assessed at the time of admission and discharge among 100 stroke patients who were admitted in a university hospital. Results: Comparing to functional status at admission of acute stroke patients, the overall functional status at discharge was improved. However, functions on defecation, skin protection, and relationship with immediate family at the time of discharge were not significantly changed. Conclusion: The set of ICF functional items identified in this study may be reliable and valid to assess acute stoke patients' body functions, activities and participation and environmental factors in the holistic and comprehensive nursing context. Nursing interventions on bowel elimination and skin protection for acute stroke patients need to be developed.

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.3
• /
• pp.356-363
• /
• 2014

This paper covers improvement of the humanoid robot platform HUBO2, known as the HUBO2+. As a necessity of the growth of the humanoid platform, a robust, reliable and user friendly platform is needed. From this standpoint, HUBO2+ is the most improved humanoid robot platform in the HUBO series. The mechanical design has been changed to increase the movable range and to stop joint compulsion. Additionally, all of the electrical parts are re-designed to be un-breakable in an unexpected situation. A smart power controller with robot status check panel is attached on the back. Additionally, a diagnosis tool, the HUBO-i, has been developed. Moreover, each joint motor controller of HUBO2+ has a Protection Function and a PODO system is provided for handling the robot easily.

• The Korean Journal of Physiology and Pharmacology
• /
• v.14 no.4
• /
• pp.199-204
• /
• 2010

The potential therapeutic action of shikonin in an experimental model of rheumatoid arthritis (RA) was investigated. As a RA animal model, DBA/1J mice were immunized two times with type II collagen. After the second collagen immunization, mice were orally administered shikonin (2 mg/kg) once a day for 35 days, and the incidence, clinical score, bone mineral density (BMD), bone mineral content (BMC) and joint histopathology were evaluated. BMD in the proximal regions of the tibia largely increased in the shikonin treatment group compared with the control group. We also examined the effect of shikonin on inflammatory cytokines and cartilage protection. Shikonin treatment significantly reduced the incidence and severity of collagen-induced arthritis (CIA), markedly abrogating joint swelling and cartilage destruction. Shikonin also significantly inhibited the production of matrix metalloproteinase (MMP)-1 and up-regulated tissue inhibitors of metalloproteinase (TIMP)-1 in mice with CIA. In conclusion, shikonin exerted therapeutic effects through regulation of MMP/TIMP; these results suggest that shikonin is an outstanding candidate as a cartilage protective medicine for RA.

• Journal of Korean Association for Spatial Structures
• /
• v.22 no.3
• /
• pp.57-64
• /
• 2022

As earthquakes have increased in Korea recently, people are paying attention to the seismic performance of buildings built in the past. Many school buildings in Korea were built based on standard drawings before the seismic design was applied. However, since school buildings are often designated as emergency evacuation facilities in case of disasters such as earthquakes, seismic evaluation and retrofit must be done quickly. This study investigated the failure modes among structural components (beams, columns, and joints), focusing on 1980s standard drawings for school buildings. The effects of column axial force, partial masonry infills, and different material strengths for concrete and rebar were considered for detailed evaluation. As a result, most of the joints were found to be the weakest among structural components. Column axial forces tended to make the joints more vulnerable, and partial masonry infills increased the possibility of joint failure and shear failure in columns.

• Journal of the Korean Society of Physical Medicine
• /
• v.15 no.3
• /
• pp.1-9
• /
• 2020

PURPOSE: This study examined the effects of muscle fatigue on proprioception in the type of taekwondo training, causing injury to taekwondo athletes. METHODS: The subjects were divided into Taekwondo Kyorugi athletes (n = 14) and Taekwondo Poomsae athletes (n = 14). After inducing muscle fatigue to the subjects, the joint position sense (JPS) and the force reproduction sense (FRS) were measured before and immediately after the induction of muscle fatigue. RESULTS: Studies have shown no significant impact on the JPS and FRS caused by muscle fatigue induced by Poomsae and Kyorugi (p > .05). The JPS, however, showed a significant difference before and after Kyorugi (p < .05). The FRS showed significant differences before and after Poomsae (p < .05). Through this study, the injuries to taekwondo athletes appear to be influenced by the joint position and force reproduction. Moreover, the injury appears to affect the joint position sense in Kyorugi athletes and the force reproduction sense in Poomsae athletes. CONCLUSION: The results will contribute to injury prevention and athlete protection. In addition, the information can be used as basic data for the development of sports injuries prevention and rehabilitation programs for Taekwondo athletes. Research is needed on the customized management of sports methods and self-care to prevent sports damage, considering the athletic characteristics of the taekwondo athletes in the future.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.22 no.1
• /
• pp.107-115
• /
• 2012

The level of information protection is relatively low, in comparison with the informatisation in this country. The budget for information protection is also quite marginal at 5% of the entire information-related policy budget. The passive information protection practices by companies, which focus more on the aftermaths, lead to repeated expenses for risk management. The responses to the violation of information protection should be changed from the current aftermaths-oriented focus to prevention and early detection of possible violations. We should also realize that the response to a violation of protected information is not a responsibility of an individual but a joint responsibility of the nation and the industry. South Korea has been working towards to building a systematic foundation since 2004 when guidelines were announced regarding the information protection policy and the safety diagnosis. The current level of safety policies cannot provide a perfect protection against actual violation cases in administrative, technological and physical ways. This research evaluates the level of prevention that the current systematic protection policy offers, and discusses its limitation and possible ways for improvement. It also recommends a list effective measures for protection against information violation that companies can employ to maintain the actual target safety level.