• Korean Journal of Applied Biomechanics
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• v.32 no.1
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• pp.17-23
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• 2022

Objective: The aim of this study was to investigate the effect Tiger-step walking on the movement of the lower extremities during walking. Method: Twenty healthy male adults who had no experience of musculoskeletal injuries on lower extremities in the last six months (age: 26.85 ± 3.28 yrs, height: 174.6 ± 3.72 cm, weight: 73.65 ± 7.48 kg) participated in this study. In this study, 7-segments whole-body model (pelvis, both side of thigh, shank and foot) was used and 29 reflective markers and cluster were attached to the body to identify the segments during the gait. A 3-dimensional motion analysis with 8 infrared cameras and 7 channeled EMG was performed to find the effect of tigerstep on uphill walking. To verify the tigerstep effect, a one-way ANOVA with a repeated measure was used and the statistical significance level was set at α=.05. Results: Firstly, Both Tiger-steps showed a significant increase in stance time and stride length compared with normal walking (p<.05), while both Tiger-steps shown significantly reduced cadence compared to normal walking (p<.05). Secondly, both Tiger-steps revealed significantly increased in hip and ankle joint range of motion compared with normal walking at all planes (p<.05). On the other hand, both Tiger-steps showed significantly increased knee joint range of motion compared with normal walking at the frontal and transverse planes (p<.05). Lastly, Gluteus maximus, biceps femoris, medial gastrocnemius, tibialis anterior of both tiger-step revealed significantly increased muscle activation compared with normal walking in gait cycle and stance phase (p<.05). On the other hand, in swing phase, the muscle activity of the vastus medialis, biceps femoris, tibialis anterior of both tiger-step significantly increased compared with those of normal walking (p <.05). Conclusion: As a result of this study, Tiger step revealed increased in 3d range of motion of lower extremity joints as well as the muscle activities associated with range of motion. These findings were evaluated as an increase in stride length, which is essential for efficient walking. Therefore, the finding of this study prove the effectiveness of the tiger step when walking uphill, and it is thought that it will help develop a more efficient tiger step in the future, which has not been scientifically proven.

• Journal of the Korean Society of Radiology
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• v.16 no.5
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• pp.649-660
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• 2022

In 1959, Satomura used spectral Doppler ultrasound to express the velocity of red blood cells according to time change, and Kato defined a zero-base line that could tell the direction of blood flow, making it possible to know the direction of blood flow. This became the basis for the widely used classifications of Triphasic, Biphasic, and Monophasic. However, the above classification has limitations that confuse users with the meaning and timing of use in a clinical environment. As a result, the American Society for Vascular Medicine (SVM) and the Society for Vascular Ultrasound (SVU) A consensus document on Doppler waveform analysis was declared by the joint committee. This study tried to review this consensus and to suggest nomenclature and modifiers that can be used in the domestic vascular ultrasound clinical field. The joint committee formed by SVM and SVU recommended that the use of the triphasic waveform and the biphasic waveform be used as a multiphasic waveform rather than being used due to the ambiguity of interpretation. In addition, it was agreed to name the hybrid-type waveform, which is a monophasic and high-resistance waveform, which has always been a problem of interpretation in a clinical environment, as an intermediate resistive waveform. In addition, in order to increase the communication efficiency between the interpreter and the sonographer, waveform analysis was classified into a main descriptor and a modifier, and it was recommended to use a single nomenclature by unifying various synonyms. It is expected that this literature review will provide accurate arterial spectral Doppler waveform interpretation and an agreed-upon nomenclature to radiologists performing vascular ultrasound examination in clinical practice, and will be utilized as basic data that can contribute to the improvement of public health.

• Physical Therapy Korea
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• v.20 no.1
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• pp.55-63
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• 2013

This study investigated the effects of axillary crutch length on trunk muscle activity and lumbo-pelvic-hip complex movements during crutch gait. Eleven healthy men participated in this study. The participants performed a three-point gait with optimal, shorter, and longer crutch lengths. Weight-bearing (WB) side was determined as the dominant leg side. The electromyography (EMG) activity of the bilateral rectus abdominis (RA) and erector spinae (ES) muscles and lumbo-pelvic-hip complex movements were monitored using a three-dimensional motion system with wireless surface EMG. Differences in the EMG activity of RA and ES muscles and range of motion (ROM) of lumbar spine, pelvis, and hip among conditions were analyzed using one-way repeated-measures analysis of variance, and a Bonferroni correction was conducted. There was less RA muscle activity on the WB side under the optimal crutch length condition compared with shorter and longer crutch length conditions (p<.05). The EMG activity of the RA muscle on the non-WB side and ES muscle on the WB side were significantly decreased under the optimal crutch length condition compared with shorter crutch length condition (p<.05). No significant differences in the EMG activity of the ES muscle on the non-WB side and ROM of lumbo-pelvic-hip complex were found among conditions (p>.05). These findings indicate that the optimal crutch length improves the trunk muscle efficiency during crutch gait.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.6
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• pp.469-476
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• 2012

In this paper, a finite element domain decomposition method using local and mixed Lagrange multipliers for a large scal structural analysis is presented. The proposed algorithms use local and mixed Lagrange multipliers to improve computational efficiency. In the original FETI method, classical Lagrange multiplier technique was used. In the dual-primal FETI method, the interface nodes are used at the corner nodes of each sub-domain. On the other hand, the proposed FETI-local analysis adopts localized Lagrange multipliers and the proposed FETI-mixed analysis uses both global and local Lagrange multipliers. The numerical analysis results by the proposed algorithms are compared with those obtained by dual-primal FETI method.

• Journal of the Korea Society of Computer and Information
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• v.10 no.6 s.38
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• pp.345-354
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• 2005

A mobile manipulator - a serial connection of a mobile robot and a task robot - is a very useful system to achieve various tasks in dangerous environment, because it has the higher performance than a fixed base manipulator in terms of its operational workspace size as well as efficiency. A method for estimating the position of an object in the Cartesian coordinate system based upon the geometrical relationship between the image captured by 2-DOF active camera mounted on mobile robot and the real object, is proposed. With this Position estimation, a method of determining an optimal path for the mobile manipulator from the current position to the position of object estimated by the image information using homogeneous matrices. Finally, the corresponding joint parameters to make the desired displacement are calculated to capture the object through the control of a manipulator. The effectiveness of proposed method is demonstrated by the simulation and real experiments using the mobile manipulator.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.4 s.119
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• pp.448-454
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• 2007

In this paper, the game theory based power control for CDMA system is studied, which has attained intensive interest as a core artificial intelligent technology fur cognitive Radio and its efficiency is evaluated using performance metrics such as system throughput and fairness. Utility Function for joint user centric and network centric power control is defined and simulation results show that game theory based power control is far better than closed loop power control. The contribution of this raper is to formalize the game theory based power control toward the cognitive radio that recognizes and adapts to the radio communication environments.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.4
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• pp.475-482
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• 2010

Thirty-six Najdi ram lambs, weighing an average of 24 kg and circa 3 months old, were utilized in this trial to evaluate the effects of various alfalfa hay particle lengths in the diet on growth performance, digestion coefficients, nitrogen retention and carcass characteristics. Lambs were randomly allotted to three dietary treatments: 9.5 and 14 mm diets, where alfalfa hay was processed to 9.5 and 14 mm particle lengths, respectively, mixed with 3 parts of concentrate and pelleted as a total mixed ration (TMR), and long hay diet, where one part of loose alfalfa hay (17.8${\pm}$2.4 cm) was offered in combination with 3 parts of only-concentrate pellet. All dietary treatments were homogeneous in their ingredient composition. All lambs were slaughtered after a 14-week feeding trial. Although the results showed no significant effect of hay particle length on DMI, TDN and DCP, lambs fed the 9.5 mm pelleted diet had higher (p<0.05) final body weight, ADG, gain efficiency and nitrogen retention than lambs fed the 14 mm and long hay diets. Altering the particle length of alfalfa hay in diets did not affect the digestibility of DM or CP, whereas digestibilities of ADF and NDF were 3.7% and 5.4% higher (p<0.05), respectively, for the long hay diet versus the 9.5 mm pelleted diet. Hot carcass weight, percentage of separable lean from the $9-11^{th}$ rib joint, and percentages of protein and EE in the separable lean increased (p<0.05) as the particle length of alfalfa hay in the diet decreased. Under the conditions of this study, the reduction of particle length in the TMR played an important role in enhancing performance without altering DM consumption, and this may lead to more efficient productivity of lamb fattening compared with longer chopping lengths.

• Journal of Broadcast Engineering
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• v.18 no.3
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• pp.401-408
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• 2013

In this paper, we propose a method that automatically detects organs having similar appearances in medical images by learning both context and appearance features. Since only the appearance feature is used to learn the classifier in most existing detection methods, detection errors occur when the medical images include multiple organs having similar appearances. In the proposed method, based on the probabilities acquired by the appearance-based classifier, new classifier containing the context feature is created by iteratively learning the characteristics of probability distribution around the interest voxel. Furthermore, both the efficiency and the accuracy are improved through 'region based voting scheme' in test stage. To evaluate the performance of the proposed method, we detect femur and tibia which have similar appearance from SKI10 knee joint dataset. The proposed method outperformed the detection method only using appearance feature in aspect of overall detection performance.

• New & Renewable Energy
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• v.16 no.1
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• pp.47-57
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• 2020

In Floating PV (Photovoltaic) systems, PV modules are installed on water by utilizing the surface of idle water such as a reservoir and multipurpose dam. A floating PV system, therefore, has the advantage of efficiency in national land use and improved energy yield owing to cooling effect compared to on-land PV systems. Owing to the limitation of installation environment for a floating PV system, the system, however, has the disadvantage of an increase in transmission distance of DC (Direct current) cables. A longer transmission distance of a DC cable results in greater power loss due to a voltage drop. This leads to a decline in economic feasibility for the floating PV system. In this paper, the economic analysis for 10 floating PV systems installed in a reservoir has been conducted in terms of a change in annual power sales according to the variation of transmission losses depending on the factors affecting the voltage drop, such as transmission distance, cross-section area of underwater cable, the presence of joint box, and PV capacity.

• Journal of architectural history
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• v.18 no.4
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• pp.63-79
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• 2009

Since the 1970's, UNESCO and ICOMOS have adopted or emphasized on the principles of historic preservation. One of them is what to require a repair have not to be repaired beyond the limits of the features and techniques to have been born in those days of establishment. On the premise, this paper is to examine the materials and technique of lime plaster work in order for roof ridge, and for bond paste of stones and bricks in government constructions in the late of Joseon dynasty(17~19c). The result of this examination will come up with a basic conformity in the case of repairing the building established in the late of Joseon dynasty. This paper is carried out for the proper repair and restoration of architectural cultural properties. Construction reports and other documents in those days are examined for the study. Following conclusions have been reached through the study. The components of old plaster mixtures which agglutinate stones each other were quicklime, perilla oil, and paper fiber. The components of old plaster mixtures which point joint of black bricks consisted of slaked lime, perilla oil, paper fiber, and cereal starch. These components were the same as coat surface of roof ridges. In the case of times, one of the following sand, white clay, sap of boiled elm bark was added to these components for the purpose of high efficiency. These materials and techniques which applied to plaster work of those buildings had developed in the process of making royal tombs. But these materials and techniques were quite different from the present.