• Journal of Biomedical Engineering Research
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• v.35 no.2
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• pp.14-18
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• 2014

This study is about e-Book program based on human-computer interaction(HCI) system for physically handicapped person. By acquiring background knowledge of HCI, we know that if we use vision-based interface we can replace current computer input devices by extracting any characteristic point and tracing it. We decided betweeneyes as a characteristic point by analyzing facial input image using webcam. But because of three-dimensional structure of glasses, the person who is wearing glasses wasn't suitable for tracing between-eyes. So we changed characteristic point to the bridge of the nose after detecting between-eyes. By using this technique, we could trace rotation of head in real-time regardless of glasses. To test this program's usefulness, we conducted an experiment to analyze the test result on actual application. Consequently, we got 96.5% rate of success for controlling e-Book under proper condition by analyzing the test result of 20 subjects.

• Journal of Medicine and Life Science
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• v.16 no.3
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• pp.64-75
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• 2019

Vertigo and dizziness are common symptoms with various etiologies and pathogeneses. Vertigo is an illusion of motion due to disease of the vestibular system, usually a sense of rotation. Dizziness, a term that represents a wide range of non-vertigo symptoms, is commonly associated with non-vestibular disorders including old age, cardiac syncope, orthostatic hypotension, metabolic disease, anxiety, and drugs. Vertigo should be determined whether the cause is central or peripheral. Peripheral vertigo is usually benign but central vertigo is serious and often require urgent treatment. The careful history and detailed physical examinations(pattern of nystagmus, ocular tilt reaction, head impulse test and positional tests such as Dix-Hallpike maneuver) provide important clues to the diagnosis of vertigo. Most of patients have benign peripheral vestibular disorders - vestibular neuritis, benign paroxysmal positional vertigo (BPPV), and Meniere's disease. BPPV is a leading cause of peripheral vertigo and can easily be cured with a canalith repositioning maneuver. In this review, a focus is on the differential diagnosis of common vestibular disorders with peripheral and central causes.

• The KSFM Journal of Fluid Machinery
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• v.9 no.1 s.34
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• pp.32-39
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• 2006

Recently, according to the trend of small size in scale and high speed in rotation of turbomachinery, very low specific speed centrifugal pump is taking a growing interest because the pump is characterized by high head and low flow rate with convenience of manufacturing and maintenance compared with conventional positive displacement pump. However, the efficiency of the very low specific speed centrifugal pump drops rapidly with the decrease of specific speed. The purpose of this study is nor only to examine the influence of casing type on the performance of centrifugal pump in the range of very low specific speed but also to determine the proper casing type for the improvement of pump performance. The results show that circular casing is suitable for the centrifugal pump in the range of very low specific speed and the influence of impeller configuration on the pump performance is very small. Radial thrust in the circular and volute casings is considerably small in the range of very low specific speed.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.17 no.2
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• pp.1-9
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• 2011

Background: Injury or pain in the neck can affect proprioception. People who have a reduced proprioception are easily exposed to induce injury or pain. The aim of this study was to examine the reduced proprioception among people who had lateral flexion postural habit of neck in a sitting position. Methods: Twenty subjects with lateral flexion postural habit were compared with a matched control group. Relocation errors in 30 degree rotation to the right were measured three times with and without visual information randomly. Results: Relocation errors were higher in the lateral flexion postural group than the control group with (p<.01) and without (p<.005) the visual information. Visual information didn't affect the cervical relocation errors in the abnormal and control groups. Repetition is increased the relocation errors with (p<.01) and without (p<.001) visual information. Conclusions: The results support the hypothesis that subjects with lateral flexion postural habit have incorrect perception of their head position. It is necessary to realize the possibility of injury or pain found among people with lateral flexion postural habit.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.10 no.1
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• pp.25-30
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• 2010

This paper is proposed about three axis motion control camera design method based on wires. Original motion control camera consists of track, boom, L-Head, Camera and so on and is enormous and expensive. But proposed motion control camera adjusts wire length using encoders and motors. And position control use position based straight line of straight-line move method for moving precise position. Proposed simple design is able to use various place and inexpensive than original motion control camera. But, camera was vibrated and rotated due to basic property of wire. So we proposed solutions that connected method of wire and using a tensional object for reducing rotation. For proposed algorithm verification, we realized three axis motion control camera based on wire and measured oscillation while moving same trace. We confirmed the results that standard deviation of oscillation was reduced 4.93 degree than before design method.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.913-922
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• 2009

Fourteen model pile load tests using a calibration chamber and instrumented model pile were preformed to investigate the variation of the behaviors of driven piles in sands with soil and lateral cyclic loading conditions. Results of the model tests showed that the first loading cycle generated more than 70% of the pile head rotation developed for 50 lateral loading cycles. Lateral cyclic loading also made an increase of the ultimate lateral load capacity of piles for $K_0$=0.4 and an decrease for $K_0$ higher than 0.4. Higher portion of the increase or decrease in the ultimate lateral load capacity by lateral cyclic loading was generated for the first loading cycle due to densification of loosening of the soil around the pile by lateral cyclic loading. It was also observed that a two-way cyclic loading caused higher ultimate lateral load capacity of driven piles than a one-way cyclic loading. When the pile was in the ultimate state, the maximum bending moment developed in the pile increased with increasing $K_0$ value of soil and was insensitive to the magnitude and number of lateral cyclic loading.

• Korean Journal of Ichthyology
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• v.21 no.2
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• pp.81-86
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• 2009

The spermiogenesis and mature spermatozoa of Pseudobagrus fulvidraco were described by means of scanning and transmission electron microscopy. Spermiogenesis is characterized by lateral development of the flagellum, nuclear rotation, deep nuclear fossa formation and compaction into thick granules. The spermatozoa exhibit a round head containing a nucleus that lacks an acrosome, and having a midpiece and a flagellum. The midpiece is small and has a short cytoplasm including several mitochondria separated from the tail by the cytoplasmic canal. The flagellum contains the 9+2 classical axoneme structure and has two axonemal fins. The presence of axonemal fins in the flagellum is a common character in Bagridae. The interrelationships among the Bagridae as well as other teleosts are herein discussed.

• Nuclear Engineering and Technology
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• v.52 no.10
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• pp.2183-2195
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• 2020

A mathematical model for the flowrate and rotation speed of RCP during idling was established. The numerical calculation method and dimensionless method were used to analyze the flow, head, torque and pressure and speed changes under idle conditions. Regularity, using the Q criterion vortex identification judgment method combined with surface flow spectrum morphology analysis to diagnose the vortex dynamic characteristics on RCP blade. On impeller blade, there is two oscillations in the pressure ratio on pressure surface in blade outlet region. The velocity on the suction surface is two times more oscillating than the inlet of blade, and there is an intersection with the velocity ratio curve on pressure surface. On blade of guide vane, the pressure ratio increases along the inlet to outlet direction, and the speed ratio decreases with the increase of idle time. There is a vortex that rotates counterclockwise on the suction surface, and the streamline on the suction surface of blade is subjected to the entrainment and blocking action of the vortex creates a large reverse flow in the main flow region. There are two vortices at the outlet of guide vane suction side and the vortices are in opposite directions.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.1
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• pp.139-147
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• 2015

This paper is the second investigation on the evaluation methods of flow characteristics in a steady flow bench. In the previous work, several assumptions used in the steady flow bench were examined and it was concluded that the assumption of the solid rotation might cause serious problems. In this study, intake valve angle is selected as a main parameter for the assessment because the main flow direction to cylinder governed by this angle has the strongest influence on the in-cylinder flow pattern. For this purpose, four heads, which have the different angle, are prepared and the flow characteristics are estimated both by the conventional impulse swirl meter and a particle image velocimetry at 1.75 times bore position apart from the cylinder head, which is widely used plane in the steady flow measurement. The results show that both of the eccentricity and the velocity profile distort the flow characteristics when using the ISM at 1.75 plane, however, the effects of two factors act in the opposite direction. In addition, the profile's influence is much greater than that of the eccentricity.

• Korean Journal of Applied Biomechanics
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• v.24 no.4
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• pp.339-347
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• 2014

The purpose of this study was to investigate joint torques of lower body segments on professional golfers. Three dimensional swing analysis was conducted on the seven subjects. Each subject was asked to swing with 45 inches of Callaway driver, where two force plates (9286AA, Kistler, Switzerland) were built, with his normal speed and tempo. The resultant joint moments of the lower extremities were computed using the kinematic variables of the segments, anthropometric measures and the ground reaction force data by inverse dynamics method. Based on the results of this study, the following conclusions were drawn; It was found that the left ankle joint torque at 3rd phase was increased toward extension on the X-axis and abduction on the Y-axis. The left knee joint torque was alternated from flexion to extension direction in order to lower down the body weight at the beginning of the downswing. The lumbar joint torque was alternated from flexion to extension in order to speed up the upper body rotation which could increase the club head speed ultimately.