• Applied Microscopy
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• v.38 no.1
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• pp.51-61
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• 2008

This simulation study examined the effect of data acquisition error including the data type of TEM image, and incident beam intensity of the tilt series on 3D tomograms. Simulation was performed with the 3D head phantom model of Kak and Slaney, and the slightly modified 3D head phantom model with enhanced difference in absorption coefficients. Reconstructed tomogram for the original head phantom model using 8-bit gray-scale image was distorted with extremely high level of noise, while an acceptable result was obtained for the modified model. The results for the original model using wrong formulation for the transmitted beam intensity was proved to be incorrect. The high level of noise along the z direction was found in case of the modified model. On the other hand, the wrong value of incident beam intensity in both models gave distorted results. In order to reconstruct an artifacts-free 3D structure from the projections with invisible features in electron tomography, the 16-bit projection images should be used with the correct incident beam intensity which is applied to Beer's law.

• Clinical and Experimental Pediatrics
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• v.46 no.12
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• pp.1274-1278
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• 2003

Syncope in children and adolescents have a common occurrence according for up to 15% before adulthood. Micturition syncope, a kind of situational syncope, can be considered a form of reflex syncope. It can typically occur in healthy young men after rising from bed in the early morning who experience sudden loss of consciousness during or immediately after urination. The mechanism of micturition syncope is not completely understood, but it has been suggested that vasovagal reflex mediated bradycardia and peripheral vasodilation and decreased venous return due to Valsalva effect and standing position lead to the decrease in cerebral blood flow resulting in syncope. The causes of syncope are variable. So complete history taking, physical examination, electrocardiography, exercise stress test, echocardiography, head-up tilt table test, electroencephalography(EEG), brain magnetic resonance image and urodynamic study should be required for the diagnosis of micturition syncope. There were several reports about micturition syncope. However, literature of micturition syncope at the pediatric age has rarely been reported in Korea so far. Therefore, we report a case of a 9-year-old boy with micturition syncope with typical EEG findings of high amplitude delta wave and flattening during syncope.

• Journal of the Korean Society of Radiology
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• v.12 no.1
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• pp.115-122
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• 2018

The success of the total hip arthroplasty is revealed as initial stability, range of motion, and long term pain, etc. Depending upon choice of implantation options such as femoral neck offset, diameter of the femoral head, the lateral opening tilt. Especially the impingement between femoral head component and acetabular cup limits the range of motion of the hip. In this sense, estimation or evaluation of the range of motion before and after the total hip arthroplasty is important. This study provides the details of a computer simulation technique for the hip range of motion of intact hip as well as arthroplasty. The suggested method defines the hip rotation center and rotation axes for flexion and abduction, respectively. The simulation uses CT-based reconstructed 3D models and an STL treating software. The abduction angle of the hip is defined as the superolateral rotation angle from sagittal plane. The flexion angle of the hip is defined as the superoanterior angle from the coronal plane. The maximum abduction angle is found as the maximum rotation angle by which the femoral head can rotate superolaterally about the anterior-posterior axis without impingement. The maximum flexion angle is found as the maximum rotation angle by which the femoral head can rotate superoanteriorly about the medial-lateral axis without impingement. Compared to the normal hip, the total hip replacement hip showed decreased abduction by 60 degrees and decreased flexion by 4 degrees. This measured value implies that the proposed measurement technique can make surgeons find a modification of increase in the femoral neck offset or femoral head, to secure larger range of motion.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1178-1183
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• 2003

As personal robots coexist with a person with a role to help a person, while adapting various human life and environment, the personal robots have to accommodate frequently-changing or different-from-home-to-home environment. In addition, personal robots may have many kinds of different Kinematic configurations depending on the capabilities. Some may have a mobile base and others may have arms and a head. The motivation of this study arises from this not-well-defined home environment and varying Kinematic configuration. So the goal of this study is to develop a general control architecture for personal robots. There exist three major architectures; deliberative, reactive and hybrid. We found that these are applicable only for the defined environment with a fixed Kinematic configuration. Neither could accommodate the above two requirements. For the general solution, we propose a Supervised Hybrid Architecture (SHA), in which we use double layers of deliberative and reactive controls, distributed control with a modular design of Kinematic configurations, and real-time Linux OS. Deliberative and reactive actions interact through a corresponding arbitrator. These arbitrators help a robot to choose an appropriate architecture depending on the current situation to successfully perform a given task. The distributed control modules communicate through IEEE 1394 for the easy expandability. With a personal robot platform with a mobile base, two arms, a head and a pan-tilt stereo eye system, we tested the developed SHA for static as well as dynamic environments. For this application, we developed decision-making rules for selecting appropriate control methods for several situations of navigation task. Examples are shown to show the effectiveness.

• Fisheries and Aquatic Sciences
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• v.12 no.2
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• pp.152-161
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• 2009

The largehead hairtail (Trichiurus lepturus) is one of the most common fisheries stocks in the East China Sea and the Yellow Sea. The species is caught using a variety of fishing tools, such as a stow net or a long line, as well as jigging and trawling. Scientific investigations have been conducted throughout the world to enable evidence-based estimations for the management and protection of the main fisheries biomass. For example, inshore and offshore hydro acoustic surveys are performed annually using bottom- and mid-water trawls around the Korean Peninsula. However, to date, no acoustic survey has been conducted to estimate fish size distribution, which is necessary to construct a data bank of target strength (TS) relative to fish species, length (L), and frequency. This study describes the frequency and length dependence of TS among fishes in Korean waters for the purpose of constructing such a TS data bank. TS measurements of the largehead hairtail were carried out in a water tank (L 5 m$\times$width 6 m$\times$ height 5 m) at frequencies of 50, 75, 120, and 200 kHz, using a tethering method. The average TS patterns were measured as a function of tilt angle, ranging from $-45^{\circ}$ (head down) to $+45^{\circ}$ (head up) every $0.2^{\circ}$. The length conversion constant ($b_{20}$) was estimated under the assumption that TS is proportional to the square of the length. In addition, in situ TS measurements on live largehead hairtails were performed using a split beam echo sounder.

• The KIPS Transactions:PartB
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• v.10B no.4
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• pp.459-464
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• 2003

This paper proposes the use of a wavelet based image transform algorithm in human iris recognition method and the effectiveness of this technique will be determined in preprocessing of extracting Iris image from the user´s eye obtained by imaging device such as CCD Camera or due to torsional rotation of the eye, and it also resolves the problem caused by invariant under translations and dilations due to tilt of the head. This technique values through the proposed translation-invariant wavelet transform algorithm rather than the conventional wavelet transform method. Therefore we extracted the best-matching iris feature values and compared the stored feature codes with the incoming data to identify the user. As result of our experimentation, this technique demonstrate the significant advantage over verification when it compares with other general types of wavelet algorithm in the measure of FAR & FRR.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.4
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• pp.81-90
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• 2017

This paper presents a smart seat for correction of driver posture while driving. We introduce good postures with seat height, seat angle, head height, back of knees, distances of foot pedals, tilt of seat, etc. There have been some studies on correction of good posture while driving, effects of driving environment on driver's posture, sitting strategies based on seating pressure distribution, estimation of driver's standard postures, and others. However, there are a few studies on guide of good postures while driving for problem of driver's posture using machine leaning. Therefore, we suggest a smart seat for correction of driver's posture based on machine leaning, 1) developed the system to get postures by 10 piezoelectric effect element, 2) collect piezoelectric values from 37 drivers and 28 types of cars, 3) suggest 4 types of good postures while driving, 4) analyze test postures by kNN. As the results, we can guide good postures for bad or problems of postures while driving.

• Journal of Biomedical Engineering Research
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• v.28 no.1
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• pp.1-7
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• 2007

To determine the effect of posture change on autonomic activity and to investigate valid parameters to reflex the autonomic activity from time-series pupil size data, a posture-related experiment was performed with 15 subjects, which involved measuring their electrocardiograms and pupil sizes. The experimental procedure consisted of three-sequence postures-supine, sitting and upright-for 5 minutes each, with rest sessions between postures. The subjects were notified of the entire experimental procedure. The parameters of the subjects' heart rate variability showed significant differences between the postures (heart rate: 63-70-80 beat, normalized low frequency power: 28-50-75, normalized high frequency power: 72-49-25 and ratio: 0.5-1.2-4.4 in supine-sitting-upright position respectively) as did the parameters of their mean pupil sizes (41300-53900-53700 pixels respectively) and the major frequencies (the third trend: 0.23-0.2-0.18 Hz respectively) of their pupil size variability according to changes in their autonomic activities induced by posture change. The experiment thus proved that posture change affects autonomic activity and that such activity can be estimated by the parameters of pupil size as similar as heart rate variability.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.3
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• pp.337-344
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• 2017

In this paper, the optical axis alignment(OAA) of an infrared sensor(IRS) using a microwave sensor(MWS) was presented as a method of an axis alignment to minimize the problems that could be caused by the misalignment of the two sensors in the missile including the dual-mode sensor. The azimuth(AZ) and elevation(EL) angles of the two targets used for each sensor test were calculated by using the transformation equation and the test results of the MWS and IRS, and then the proposed OAA was verified by comparing the angles. Furthermore, the validity of the proposed OAA was demonstrated by confirming the abnormality of the OAA through the test results of the electro optical head(EOH) of the IRS which was equipped with a tilt on the missile fuselage.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.2
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• pp.193-200
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• 2013

PURPOSE: The purpose of this study was to find out variations in body posture by using the baby carrier at the front side and back side. METHODS: Thirty two healthy and young female who will bring up infants and had no musculoskeletal disorders of neck, lumbar and low limb were recruited for this study. They were each marked about ears of tragus, cervical 7th, acromion anterior end, anterior superior iliac spine, posterior superior iliac spine, greater trochanter and lateral malleolus as landmarks to measure variations of body posture when they carry infants at the front side and back side. Landmarks were regarded as the creteria in order to measure NeckFlexion angle(NF), Foreward shoulder angle(FSA), Pelvic tilt(PT), Sway angle(SA), Head displacement(HD) and Scapular displacement(SD). Variations in body posture were measured from the neutral position to the front and back side by using Image J. RESULTS: There were significance level (p<.05) in NF, PT, SA, HD and SD except for FSA in two different side. CONCLUSION: The results of this study indicate that each of the using ways of baby carrier for baby care was influenced postural responses of young women. therefore, it could be considered to apply to women who have abnormal body posture in order to minimize musculoskeletal disorders.