• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.742-747
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• 2004

Hard disk drives (HDD) in computer are used extensively as data storage capacity. PIV measurement system was used fur 2-dimensional visualization of the unsteady flow between co-rotating disks in air both with a shroud and both with a actual-like case. Geometric parameters are gap height (H) between disks in the case of shroud. The lobe- structured boundary between inner region and outer region was visualized, and the number of dominant vertices was determined clearly. It is found from flow visualization that the number of vortex cells can be correlated with Reynolds number based on H which is defined as R $e_{H}$ =ΩRH/v ranging from 7.96$\times$10$^2$ to 1.43$\times$10$^4$, and decreases as the disk speed increases. In the case of a actual-like case, the boundary between inner region and outer region appears cleary when head position located at outer diameter with no damper. It is detected with a case of head position middle diameter that the tip wake is generated behind HGA using PIV measurement and calculation.n.

• Transactions of the Society of Information Storage Systems
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• v.1 no.1
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• pp.99-107
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• 2005

According to recent trend, hard disk drive(HDD) has been smaller and less weight. Therefore, it needs new method of writing position information. In this thesis, a new controller that is suitable for SSW is proposed. The controller accepted SSW technology that is used to write position information in current HDD industry. The important condition to perform SSW is to reach constant velocity decided from the head velocity profile as fast as possible. The constant velocity decides the positional accuracy of spiral pattern and setup time decides the capacity of HDD. The head velocity profile as a reference signal must be designed not to cause resonance mode. The proposed controller was designed with consideration of these 3 elements, and it properly works for SSW. The velocity profile designed with SMART control not only minimizes the jerk, but also does not cause the resonance mode of a plant. After designing a conventional PID controller, it compared with electrical spring technique and ZPET technique.

• Physical Therapy Korea
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• v.13 no.4
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• pp.64-70
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• 2006

The purpose of this study was to determine whether a relationship existed between foot type and the location of plantar callus in healthy subjects. Twenty-five healthy subjects with plantar callus were recruited for this study. Foot deformities were classified according to the operational definitions as 1) a compensated forefoot varus, 2) an uncompensated forefoot varus or forefoot valgus, or 3) a compensated rearfoot varus. The location of plantar callus was divided into two regions. Fourteen of the 19 feet with compensated forefoot varus and six of the 9 feet showed plantar callus at the second, third or fourth metatarsal head. Five of the 6 feet with uncompensated forefoot varus and twenty of the 16 feet with forefoot valgus showed plantar callus at the first or fifth metatarsal head. A significant relationship was found between foot type and location of callus (p<.01). The results support the hypothesis that certain foot types are associated with characteristic patterns of pressure distribution and callus formation. We believe diabetic patients with insensitive feet and with the types of foot deformity should be fit with foot orthoses and footwears that accommodate their respective deformity in a position as near to the subtalar joint as possible with the goal of preventing plantar ulceration.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.13 no.1
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• pp.95-99
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• 1991

Several authors have proposed techniques and devices by which the correct position of the proximal segment can be maintained both during fixation and postoperatively. Schendel, Epker, Lake, Worms, Ive and Poulton have been discussed the problem of condylar distration in mandibular orthognathic surgery. This study described have showed the some advantages forward repositioning of the condyle head in vertical ramus osteotomy which used with the Mini-Hoffmann sets in external skeletal pin fixation extraorally in 19 cases.

• Journal of Korea Multimedia Society
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• v.19 no.12
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• pp.1927-1935
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• 2016

This paper propose a framework for human body parts in RGB-D image. We conduct tasks of obtaining person area, finding candidate areas and local detection in order to detect hand, foot and head which have features of long accumulative geodesic distance. A person area is obtained with background subtraction and noise removal by using depth image which is robust to illumination change. Finding candidate areas performs construction of graph model which allows us to measure accumulative geodesic distance for the candidates. Instead of raw depth map, our approach constructs graph model with segmented regions by quadtree structure to improve searching time for the candidates. Local detection uses HOG based SVM for each parts, and head is detected for the first time. To minimize false detections for hand and foot parts, the candidates are classified with upper or lower body using the head position and properties of geodesic distance. Then, detect hand and foot with the local detectors. We evaluate our algorithm with datasets collected Kinect v2 sensor, and our approach shows good performance for head, hand and foot detection.

• Journal of Mechanical Science and Technology
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• v.14 no.11
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• pp.1232-1243
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• 2000

Motor vehicle accidents in rear impacts cause more than fifty percents of drivers to suffer from neck injuries. It is known that most neck injuries are associated with rear-end collisions at a speed lower than 32 km/h and between the Abbreviated Injury Scale (AIS) 1 and AIS 2. Two different types of low speed crash tests such as the frontal barrier and rear moving barrier crashes have been conducted by following the procedure of the Research Committee for Automobile Repairs (RCAR). The injury for the neck and the Head Injury Criteria (HIC) were measured by using the sensors mounted on dummies. We reviewed neck injures and the relationship between the neck and head injuries, and examined the deceleration of the body. Using the experimental test data at the neck, we investigated an improved neck injury criterion Nij. Also, the effects of the position of a head restraint on reducing the frequency and severity of the neck injury in rear-end collisions were investigated.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.46 no.5
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• pp.38-43
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• 2009

We derive an equation that predicts the induced voltage across the receiving terminals of the three-coil head of a metal detector using a magnetic vector potential approach. We also derive an equation that relates the change of the impedance of the transmitting coil to the properties of the metal. We utilize the results to obtain the optimum spacing between the driving and the receiving coils at which the maximum induced voltage is attained. Further, we determine the position of the metallic object where the voltage reaches its peak. We verify our work by comparing the results with those of a previous work.

• ETRI Journal
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• v.34 no.4
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• pp.542-552
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• 2012

In this paper, a gaze estimation method is proposed for use with a large-sized display at a distance. Our research has the following four novelties: this is the first study on gaze-tracking for large-sized displays and large Z (viewing) distances; our gaze-tracking accuracy is not affected by head movements since the proposed method tracks the head by using a near infrared camera and an infrared light-emitting diode; the threshold for local binarization of the pupil area is adaptively determined by using a p-tile method based on circular edge detection irrespective of the eyelid or eyelash shadows; and accurate gaze position is calculated by using two support vector regressions without complicated calibrations for the camera, display, and user's eyes, in which the gaze positions and head movements are used as feature values. The root mean square error of gaze detection is calculated as $0.79^{\circ}$ for a 30-inch screen.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.27 no.2
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• pp.134-137
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• 2016

A Killian-Jamieson diverticulum (KJD) is an unfamillar and unusual cervical esophageal diverticulum. This diverticulum originates on the anterolateral aspect of the esophagus through the Killian-Jamieson's area that is formed between cricopharyngeal muscle and the lateral to longitudinal esophageal muscle. Recently, we experienced a patient who was found outpouching lesion on lateral side of left esophagus on the duodenoscopy. Then, a barium esophagography performed and in left lateral position demonstrated a left-sided diverticulum with a frontal projection, highly suggestive of a KJD. There are two ways of surgical approach to manage the KJD. First is external approach, another one is endoscopic approach. In common, external approach has been recommended for the treatment of KJD because of concern of nerve injury. We present a case of KJD that underwent external approach and sternocleidomastoid muscle flap in the management of KJD.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.101-104
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• 2004

This paper addresses uncertainty issues encountered recently in measuring head vibration using the conventional 6-axis or 9-axis bite-bar Those conventional bite-bars are shown to present insufficient information to measure a complete 6 degree-of-freedom motion of head vibration. In order to overcome such limit, a theoretical measurement model that consists of four 3-axis linear accelerometers is suggested (Theoretical backgrounds presented in this paper shall have been addressed in the international congress of ICA 2004 in this April). It is shown to enable the direct measurement of three angular acceleration components and six angular velocity-dependent nonlinear terms. In audition to the three linear acceleration terms, those nine angular motion-dependent ones are found to make it possible to evaluate the general head vibration for a given position. To examine the feasibility of the proposed method, a newly designed 12-axis bite-bar was developed. Detailed experimental results obtained using the developed 12-axis bite-bar are illustrated in the presentation of this paper, which illustrates what amount of measurement accuracy provides. But, this paper provides more detailed experimental data and extended uncertainty factors.