• Geophysics and Geophysical Exploration
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• v.10 no.3
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• pp.191-202
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• 2007

To identify the detailed attenuation structure in the southern Korean Peninsula, a numerical test was conducted for the Q tomography inversion to be applied to the accumulated dataset until 2005. In particular, the stochastic pointsource ground-motion model (STGM model; Boore, 2003) was adopted for the 2D Q tomography inversion for direct application to simulating the strong ground-motion. Simultaneous inversion of the STGM model parameters with a regional single Q model was performed to evaluate the source and site effects which were necessary to generate an artificial dataset for the numerical test. The artificial dataset consists of simulated Fourier spectra that resemble the real data in the magnitude-distance-frequency-error distribution except replacement of the regional single Q model with a checkerboard type of high and low values of laterally varying Q models. The total number of Q blocks used for the checkerboard test was 75 (grid size of $35{\times}44km^2$ for Q blocks); Q functional form of $Q_0f^{\eta}$ ($Q_0$=100 or 500, 0.0 < ${\eta}$ < 1.0) was assigned to each Q block for the checkerboard test. The checkerboard test has been implemented in three steps. At the first step, the initial values of Q-values for 75 blocks were estimated. At the second step, the site amplification function was estimated by using the initial guess of A(f) which is the mean site amplification functions (Yun and Suh, 2007) for the site class. The last step is to invert the tomographic Q-values of 75 blocks based on the results of the first and second steps. As a result of the checkerboard test, it was demonstrated that Q-values could be robustly estimated by using the 2D Q tomography inversion method even in the presence of perturbed source and site effects from the true input model.

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.337-345
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• 2009

The purpose of this study were to find out the differences in kinematic variables of racket movement by performing the tennis serve. Three top male tennis players participated in this study. Three synchronized high-speed cameras were used to record the service action of top players for Three dimensional video analysis. The results of this study showed that (1) the velocity of the tennis racket at impact is important to the generation of racket velocity to Y-axis. This result indicates that forward motion and upward movement of the racket; (2) with respect to racket angular velocity at impact, the fast angular momentum of X-axis is important to generate the velocity of the tennis ball. This result indicate upward movement of the racket with a strong flexor of wrist joint; (3) the velocity of the tennis ball was influenced by the change of angular linking the Z-axis to -X-axis. This result indicates that the high velocity of the tennis ball is obtained from having the racket unitedly moving to the direction of the bill's flight at the acceleration interval and acquiring the distance of acceleration with the racket head vertically to the ground at the back scratching.

• Korean Journal of Applied Biomechanics
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• v.31 no.4
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• pp.276-282
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• 2021

Objective: To investigate effects of Fibular Repositioning Taping (FRT) on lower extremity joint stiffness and angle during drop-landing. Method: Twenty-eight participants (14 healthy, 14 with chronic ankle instability [CAI]) performed drop-landings from a 60 cm box; three were performed prior to tape application and three were performed post-FRT. Three-dimensional kinematic and kinetic data were collected using an infrared optical camera system (Vicon Motion Systems Ltd. Oxford, UK) and force-plate (AMTI, Watertown, MA). Joint stiffness and sagittal angle of the ankle, knee, and hip were analyzed. Results: The hip [Healthy: p<.05; M ± SD: 29.43 ± 11.27 (pre), 33.04 ± 12.03 (post); CAI: p<.05; M ± SD: 31.45 ± 9.70 (pre), 32.29 ± 9.85 (post)] and knee [Healthy: p<.05; M ± SD: 53.44 ± 8.09 (pre), 55.13 ± 8.36 (post); CAI: p<.05; M ± SD: 53.12 ± 8.35 (pre), 55.55 ± 9.81 (post)] joints demonstrated significant increases in sagittal angle after FRT. A significant decrease in joint angle was found at the ankle [Healthy: p<.05; M ± SD: 56.10 ± 3.71 (pre), 54.09 ± 4.31 (post); CAI: p<.05; M ± SD: 52.80 ± 6.04 (pre), 49.86 ± 10.08 (post)]. A significant decrease in hip [Healthy: p<.05; M ± SD: 1549.16 ± 517.53 (pre), 1272.48 ± 646.73 (post); CAI: p<.05; M ± SD: 1300.42 ± 595.55 (pre), 1158.27 ± 550.58 (post)] and knee [Healthy: p<.05; M ± SD: 270.12 ± 54.07 (pre), 239.13 ± 64.70 (post); CAI: p<.05; M ± SD: 241.58 ± 93.48 (pre), 214.63 ± 101.00 (post)] joint stiffness was found post-FRT application, while no difference was found at the ankle [Healthy: p>.05; M ± SD: 57.29 ± 17.04 (pre), 59.37 ± 18.30 (post); CAI: p>.05; M ± SD: 69.15 ± 17.63 (pre), 77.24 ± 35.05 (post)]. Conclusion FRT application decreased joint angle at the ankle without altering ankle joint stiffness. In contrast, decreased joint stiffness and increased joint angle was found at the hip and knee following FRT. Thus, participants utilize an altered shock absorption mechanism during drop-landings following FRT. When compared to previous research, the joint kinematics and stiffness of the lower extremity appear to be different following FRT versus traditional ankle taping.

• Archives of Reconstructive Microsurgery
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• v.11 no.1
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• pp.11-18
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• 2002

Large soft tissue defects around the knee joint are known to significantly diminish joint function. Severe soft tissue defects on the anterior aspect of the knee joint especially bring on significant joint motion limitation. Although simple split skin grafts can cover the skin defect, the progressing scar contracture of the grafted skin causes joint stiffness. One of the best solutions of large soft tissue defects around the knee joint is covering the defect with a good quality skin flap. Separated flaps with one vascular pedicle are good candidates for covering anterior and posterior aspects of the joint for example. Authors performed 12 cases of combined scapular and latissimus dorsi free flaps from 1984 to 2000. Among them, we experienced 5 cases of knee joint defect covering using the double free flap for coverage of the soft tissue defect with preservation of the knee joint function and satisfactory results. The system of flaps based on the subscapular artery and vein provides a variety of composite free flaps. The possible flaps that can be harvested based on this single vascular pedicle include the scapular and parascapular skin flap, the serratus anterior and latissimus dorsi muscular flap, the lateral scapular bone flap, the latissimus dorsi-rib flap, and the serratus anterior-rib flap. This combined flap is available for multiple tissue defects or complex defects because it can be incorporated with skin, muscle and bone flaps. A main advantage is the independent vascular pedicles of each component, which allow freedom in orientation of each components. Consequently it can be freely applied to any form of three dimensional defects on the upper and lower extremities. The combination of scapular cutaneous flap and latissimus dorsi musculocutaneous flap can be resurfaced for massive cutaneous defects on the extremities. We report the use of the combined scapular and latissimus dorsi free flap in five patients to reconstruct massive defects on the extremities with resultant improved joint function. There was no flap failure and minimal complications and disadvantages. The anatomy of this flap is reviewed and the indication and advantages are discussed. All of the five flaps survived and there was no scar contracture affecting the joint motion.

• Journal of Environmental Science International
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• v.13 no.8
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• pp.721-731
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• 2004

The dispersion of suspended particulates in the coastal complex terrain of mountain-inland basin (city)-sea, considering their recycling was investigated using three-dimensional non-hydrostatic numerical model and lagrangian particle model (or random walk model). Convective boundary layer under synoptic scale westerly wind is developed with a thickness of about I km over the ground in the west of the mountain, while a thickness of thermal internal boundary layer (TIBL) is only confined to less than 200m along the eastern slope of the mountain, below an easterly sea breeze circulation. At the mid of the eastern slop of the mountain, westerly wind confronts easterly sea breeze, which goes to the height of 1700 m above sea level and is finally eastward return flow toward the sea. At this time, particulates floated from the ground surface of the city to the top of TIBL go along the eastern slope of the mountain in the passage of sea breeze, being away the TIBL and reach near the top of the mountain. Then those particulates disperse eastward below the height of sea-breeze circulation and widely spread out over the coastal sea. Total suspended particulate concentration near the ground surface of the city is very low. On the other hand, nighttime radiative cooling produces a shallow nocturnal surface inversion layer (NSIL) of 200 m thickness over the inland surface, but relatively thin thickness less than 100m is found near the mountain surface. As synoptic scale westerly wind should be intensified under the association of mountain wind along the eastern slope of mountain to inland plain and further combine with land-breeze from inland plain toward sea, resulting in strong wind as internal gravity waves with a hydraulic jump motion bounding up to about 1km upper level in the atmosphere in the west of the city and becoming a eastward return flow. Simultaneously, wind near the eastern coastal side of the city was moderate. Since the downward strong wind penetrated into the city, the particulate matters floated near the top of the mountain in the day also moved down along the eastern slope of the mountain, reaching the. downtown and merging in the ground surface inside the NSIL with a maximum ground level concentration of total suspended particulates (TSP) at 0300 LST. Some of them were bounded up from the ground surface to the 1km upper level and the others were forward to the coastal sea surface, showing their dispersions from the coastal NSIL toward the propagation area of internal gravity waves. On the next day at 0600 LST and 0900 LST, the dispersed particulates into the coastal sea could return to the coastal inland area under the influence of sea breeze and the recycled particulates combine with emitted ones from the ground surface, resulting in relatively high TSP concentration. Later, they float again up to the thermal internal boundary layer, following sea breeze circulation.

• The Journal of the Korea Contents Association
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• v.14 no.11
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• pp.519-532
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• 2014

The emerging technologies for the natural computer interaction can give manufacturers new opportunities of product innovation. This paper is the study on a method of human communication about a finger gestures interaction. As technological advance has been so rapid over the last few decades, the utilizing products or services will be soon popular. The purpose of this experiment are as follows; What is the usefulness of gesture interaction? What is the cognitive impact on gesture interaction users. The finger gestures interaction consist of poking, picking and grasping. By measuring each usability in 2D and 3D space, this study shows the effect of finger gestures interaction. The 2D and 3D experimental tool is developed by using LeapMotion technology. As a results, the experiments involved 48 subjects shows that there is no difference in usability between the gestures in 2D space but in 3D space, the meaningful difference has been found. In addition, all gestures express good usability in 2D space rather than 3D space. Especially, there are the attractive interest that using uni-finger is better than multi-fingers.

• The Journal of the Korean bone and joint tumor society
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• v.3 no.1
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• pp.18-25
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• 1997

Prosthetic replacement is one of the most common methods of reconstruction after resection of malignant tumor around the knee. Gait analysis provides a relative objective data about the gait function of patients with prosthesis. The purpose of this study was to compare the gait pattern of the patients who underwent limb salvage surgery with prosthesis for distal femur and that of patients with prosthesis for proximal tibia. This study included ten patients (4 males, 6 females, mean age 22.7 years, range 14-36) who underwent a wide resection and Kotz hinged modular reconstruction prosthesis replacement and six normal adult(Control). The site of bone tumor was the distal femur (Group 1) in six patients and proximal tibia (Group 2) in 4 patients. The follow-up period ranged from 15 to 82 months (mean : 33 months). The evaluation consisted of clinical assessment, radiographic assessment, gait analysis using VICON 370 Motion Analysis System. The gait analysis included the linear parameters such as, walking velocity, cadence, step length, stride length, stance time, swing time, single support and double support time and the three-dimensional kinematics (joint rotation angle, velocity of joint rotation) of ankle, knee, hip and pelvis in sagittal, coronal and transverse plane. For the kinetic evaluation, the moment of force (unit: Nm/kg) and power (unit: Watt/kg) of ankle, knee and hip joint in sagittal, coronal and transverse plane. In the linear parameters, cadence, velocity, step time and single support were decreased in both group 1 and group 2 compared with control. Double support decreased in group 2 compared with control significantly(p<.05). In contrast to our hypothesis, there was no significant difference between group 1 and group 2. In Kinematics, we observed significant difference (p<.05) of decreased knee flexion in loading response (G2

• Archives of design research
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• v.14
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• pp.1-7
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• 1996

Designers often hesitate to decide the shape, size, and layout of a product. Though ergonomic principles and data are absolutely needed in this process, they don have enough guidelines to refer. For the refrigerator designers, they also are not convinced of their decision: the vertical position of the freezing and refrigerating rooms, the height of shelves, the shape of door-handle, etc. To support the refrigerator design, we applied several ergonomic methods to the evaluation of refrigerator. EMG was measured to evaluate the load of users lumbar muscle. Based upon the experimental EMG data, we developed a model to estimate the relative load corresponding to the height of refrigerator shelves. Two different layouts of a refrigerator, R/F and F/R styles, were compared with the model. A three-dimensional motion analysis method was used to evaluate the users motion of using a refrigerator. Ten door-handles with the different shapes and positions were evaluated by tracking the rotations of the users arm. Video protocol analysis was used to evaluate the user interface of a control panel in a refrigerator. Finally, we suggested several ergonomic design guidelines based on the facts found in this research and the anthropometric data of the Korean adults. The results of this study can be applied to the ergonomic design of refrigerators

• Cartoon and Animation Studies
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• s.49
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• pp.677-696
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• 2017

Cartoons and consequently animation are an effective way of visualizing futuristic scenarios. Here we look at how animation is becoming ubiquitous and an integral part of this future today: the cybernetic and mediated society that we are being transformed into. Animation therefore becomes a form of speech between humans and this networked reality, either as an interface or as representation that gives temporal form to objects. Animation or specifically animated films usually are associated with character based short and feature films, fiction or nonfiction. However animation is not constricted to traditional cinematic formats and language, the same way that design and communication have become treated as separate fields, however according to $Vil{\acute{e}}m$ Flusser they aren't. The same premise can be applied to animation in a networked culture: Animation has become an intrinsic to design processes and products - as in motion graphics, interface design and three-dimensional visualization. Video-games, virtual reality, map based apps and social networks constitute layers of an expanded universe that embodies our network based culture. They are products of design and media disciplines that are increasingly relying on animation as a universal language suited to multi-cultural interactions carried in digital ambients. In this sense animation becomes a discourse, the same way as Roland Barthes describes myth as a type of speech. With the objective of exploring the role of animation as a design tool, the proposed research intends to develop transmedia creative visual strategies using animation both as narrative and as an user interface.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.3
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• pp.128-137
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• 2013

Due to the global warming and air pollution, interest in renewable energies has increased in recent years. In particular, the crisis of the depletion of fossil energy resources in the near future has accelerated the renewable energy technologies. Among the renewable energy resources, oceans covering almost three-fourths of earth's surface have an enormous amount of energy. For this reason, various approaches have been made to harness the tremendous energy potential. In order to achieve two purposes: to improve harbor water quality and to use wave energy, this study proposed a sea water exchange structure applying an Oscillating Water Column (OWC) wave generation system that utilizes the air flow velocity induced by the vertical motion of water column in the air chamber as a driving force of turbine. In particular, the airflow velocity in the air chamber was estimated from the time variations of water surface profile computed by using 3D-NIT model based on the 3-dimensional irregular numerical wave tank. The relationship of the frequency spectrums between the computed airflow velocities and the incident waves was analyzed. This study also discussed the characteristics of frequency spectrums in the air chamber according to the presence of the structure, wave deformations by the structure, and the power of the water and air flows were also investigated. It is found that the phase difference exists in the time series data of water level fluctuations and air flow in the air chamber and the air flow power is superior to the fluid flow power.