• Korean Journal of Applied Biomechanics
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• v.21 no.2
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• pp.197-205
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• 2011

Various jumping and landing motions are shown during sports event. But most previous studies have not considered landing height and distance simultaneously. The purpose of this study was to identify the effects of landing height and distance on knee injury mechanism. Fourteen male(age: $28.86{\pm}1.99$ yrs, height: $177.00{\pm}4.69$ cm, weight: $76.50{\pm}6.41$ kg) participated in this study. The subjects attempted drop landing task onto the ground from 30 cm to 45 cm heights and to 20 cm to 40 cm distances. The results were as follows. First, higher drop landing height and longer distance showed greater degree of maximal knee flexion and valgus. Second, higher drop landing height and longer distance showed greater maximal knee extension moment and varus moment. Third, higher drop landing height and longer distance showed larger maximal knee absorption power. Lastly, higher drop landing height showed increased Peak GRF. Landing height was more related to the cause of injury, which was indicated by increased maximal knee extension moment, peak GRF and maximal knee absorption power. Landing distance was also associated with increased knee valgus moment and absorption power during landing. These results suggest that landing height and distance may be the cause of injury.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.27 no.1
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• pp.5-13
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• 2017

Noise complaints among neighbors in apartment building are mainly caused by floor impact noise that is structure born noise due to occupant induced floor vibration. To control this noise problems many researchers have investigated floor systems and finishing materials. Light-weight impact noise affects by finishing materials, but heavy-weight impact noise induced by heel impacts during normal walking or jumping of children is concerned with structural system and floor vibration. To figure out the characteristics of floor impact noise and transmission of floor vibration due to human activities, vibration tests were conducted in apartment buildings. Impact hammer, heel drop and walking activities were loaded at center of upstairs living room, and accelerations of slabs for both upstairs and downstairs and sound pressure levels for downstairs were measured. The acceleration ratio of transmitted floor vibration to downstairs and human induced vibration in upstairs was between 0.5 and 1.0 according to slab size, wall, and load type. And floor impact noise occurred in the range of natural frequency of slab.

• Journal of the Korea Furniture Society
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• v.27 no.4
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• pp.399-411
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• 2016

Korea Furniture design development process is repeated a number of changes by the change of residence and type of market demand derived from the process of industrialization. The modernization process of industrialization advances by large-scale population moves to the city to urbanization proceeds rapidly. Housing problems are concentrated in cities and sparked the furniture industry, furniture design by changes in marketing concepts that appear in the industrialization phase, growth must necessarily accommodate the needs of consumers. Including kitchen furniture, living room furniture and master bedroom furniture has been sensitively adapted changes in the structure of these houses, particularly structural changes Apartments. Starting in the 1990s, jumping over furniture industry has adapted quickly to the market demand, changes in marketing concepts. Furniture industry is growing market share in most of the country, but the entire industry had to undergo a competitive marketing overheating due to excessive supply in excess of market demand since the mid-1990s. Changes in furniture design in this process was the change in furniture design more than the change of the residential structure. The study industrial development and marketing concepts are changing to construct a model to track the changes varied styles and time changes affect whether the main furniture design.

• Wind and Structures
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• v.30 no.5
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• pp.475-483
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• 2020

This work investigates Reynolds number Re (= 50 - 200) effects on the flows around a single cylinder and the two tandem (center-to-center spacing L^⁎= L/D = 4) cylinders, each of a diameter D. Vorticity structures, Strouhal numbers, and time-mean and fluctuating forces are presented and discussed. For the single cylinder, with increasing Re in the range examined, the vorticity magnitude, Strouhal number and fluctuating lift all monotonically rise but time-mean drag, vortex formation length, and lateral distance between the two rows of vortices all shrink. For the two tandem cylinders, the increase in Re leads to the formation of three distinct flows, namely reattachment flow (50 ≤ Re ≤ 75), transition flow (75 < Re < 100), and coshedding flow (100 ≤ Re ≤ 200). The reattachment flow at Re = 50 is steady. When Re is increased from 75 to 200, the Strouhal number of the two cylinders, jumping from 0.113 to 0.15 in the transition flow regime, swells to 0.188. The two-cylinder flow is more sensitive to Re than the single cylinder flow. Fluctuating lift is greater for the downstream cylinder than the upstream cylinder while time-mean drag is higher for the upstream cylinder than for the other. The time-mean drags of the upstream cylinder and single cylinder behaves similar to each other, both declining with increasing Re.

• Journal of Microbiology and Biotechnology
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• v.19 no.3
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• pp.217-228
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• 2009

Mobile genetic segments, or transposons, are also referred to as jumping genes as they can shift from one position in the genome to another, thus inducing a chromosomal mutation. According to the target site-specificity of the transposon during a transposition event, the result is either the insertion of a gene of interest at a specific chromosomal site, or the creation of knockout mutants. The former situation includes the integration of conjugative transposons via site-specific recombination, several transposons preferring a target site of a conserved AT-rich sequence, and Tn7 being site-specifically inserted at attTn7, the downstream of the essential glmS gene. The latter situation is exploited for random mutagenesis in many prokaryotes, including IS (insertion sequence) elements, mariner, Mu, Tn3 derivatives (Tn4430 and Tn917), Tn5, modified Tn7, Tn10, Tn552, and Ty1, enabling a variety of genetic manipulations. Randomly inserted transposons have been previously employed for a variety of applications such as genetic footprinting, gene transcriptional and translational fusion, signature-tagged mutagenesis (STM), DNA or cDNA sequencing, transposon site hybridization (TraSH), and scanning linker mutagenesis (SLM). Therefore, transposon-mediated genetic engineering is a valuable discipline for the study of bacterial physiology and pathogenesis in living hosts.

• Journal of Korean Physical Therapy Science
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• v.15 no.2
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• pp.79-86
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• 2008

Background: The purpose of this study was to present a practical method of medical treatment to improve the balance and motor ability of the mentally retarded child with a single mentally retarded child-subject. Methods: The subject of the study was a 39-month-old mentally retarded female. This study included a 2-week basic period and a 13-week treatment period. The treatment method was based on the Bobath Approach. Gross motor function measurement (GMFM) was used to examine changes in motor ability, and the Pediatric Balance Scale (PBS) was used to measure changes in balance ability. The curative program was composed of normalization of muscle tone, strengthening of leg endurance and muscular strength, the improvement of trunk alignment, and the increase of balance. Visual rate of change was used to examine the results. Results: As a result of this study, balance ability increased on the Pediatric Balance Scale (PBS) by 24 points, and motor function increased in terms of Gross Motor Function Measurement (GMFM) by 6.9% (18 points). Standing increased by 41% (16 points), and walking, running, and jumping increased by 31.9% (23 points) compared to thebasic period. Therefore, the Bobath Approach appears to be an appropriate method to improve balance and motor ability in mentally retarded children. Conclusion: It is surmised that aggressive intervention by physical therapists and occupational therapists, and a follow-up study, are required for the growth of motor ability in mentally retarded children.

• Journal of Multimedia Information System
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• v.2 no.2
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• pp.233-240
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• 2015

Mobile devices are becoming increasingly sophisticated and the latest generation of smartphones now incorporates many diverse and powerful sensors. These sensors include acceleration sensor, magnetic field sensor, light sensor, proximity sensor, gyroscope sensor, pressure sensor, rotation vector sensor, gravity sensor and orientation sensor. The availability of these sensors in mass-marketed communication devices creates exciting new opportunities for data mining and data mining applications. In this paper, we describe and evaluate a system that uses phone-based accelerometers to perform activity recognition, a task which involves identifying the physical activity that a user is performing. To implement our system, we collected labeled accelerometer data from 10 users as they performed daily activities such as "phone detached", "idle", "walking", "running", and "jumping", and then aggregated this time series data into examples that summarize the user activity 5-minute intervals. We then used the resulting training data to induce a predictive model for activity recognition. This work is significant because the activity recognition model permits us to gain useful knowledge about the habits of millions of users-just by having them carry cell phones in their pockets.

• Korean Journal of Applied Biomechanics
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• v.16 no.4
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• pp.13-20
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• 2006

A platform diving with categorizing 624C motion was video taped and 3D kinematic variables were analyzed. This motion is consist of 3 parts from the headstand position to the act of turning after take-off. The results indicated that it took a very short time from the moment of take-off to the act of 1/2 turning because the turning motion has already started from preparing motion even before the fingertips have parted from the ground. Also, there was barely any jumping height due to the use of upper limbs segment and there was little difference in the moving distance compared to the standing events judging from horizontal movement of 1.1m. The horizontal velocity of the center of human body was increased before take-off while the vertical velocity was decreased right after take-off and the velocity of lower limbs segment was faster than the upper limbs segment showing contrary results to the standing events. In the aspects of angular velocity, the upper limbs segment starts the turning motion when take-off by rapidly extending its angular velocity while lower limbs segment make large angular velocity even before take-off.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.4
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• pp.285-289
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• 2013

In switching from the track-seeking or track-jumping control mode to track-following control mode in hard disk drives or optical disk drives, initial values of the feedback controller are tuned to improve the transient response. In general, all the initial values of the controller have been compensated for this purpose. In this paper, by partially compensating initial values of digital controllers, we achieve a good performance of the transient response. In the proposed method for IVC (Intial Value Compensation), LMIs (Linear Matrix Inequalities) are used, which includes conditions for improving the performance of the transient response such as reducing a tracking error and control efforts. We obtain optimal initial values of the controller by solving an optimization problem with constraints represented by only one LMI. Although initial values of the controller are partially compensated, we can show that not only a sufficient performance of the transient response is obtained but also control efforts are diminished. The feasibility of the method is verified by simulation studies.

• Sleep Medicine and Psychophysiology
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• v.1 no.1
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• pp.99-106
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• 1994

The authors report a case of REM sleep behavior disorder which occurred in a 69-year-old business man. He began experiencing episodic "acting out" behavior of his dream at the age of 66. The episodes tended to be associated with dream contents, mainly being chased or threatened. Before that, his sleep was relatively quiet despite occasional nightmares, midsleep arousal, and shallowness. Injuries resulted from leaping out of bed, jumping onto furnitures, and grabbing and biting the spouse's arm. Most recent dream-incurred laceration of chin required 5 sutures. Medical and psychiatric history revealed no significant findings except that he had been overanxious all his life within himself with others' reputation of himself as pleasant and easy-going. A nocturnal polysomnogram showed repeatedly intermittent increase of chin and/or leg muscle tones during otherwise characteristic REM sleep period. The overnight video recording revealed head lifting and limb movements during REM sleep periods. Brain MRI and EEG were normal. Job-related stress was presumed to be an etiological possibility. Clonazepam 0.25-0.5mg nightly almost completely relieved the symptoms.