Sang-Sik Lee

Airborne formaldehyde causes skin barrier dysfunction in atopic dermatitis

It remains to be elucidated whether exposure to air pollutants aggravates atopic dermatitis (AD).

Development of a spine kinematic model for the clinical estimation of abnormal curvature

The objective of this study was to develop a new three-dimensional spine kinematic model for abnormal curvature estimation. The morphological diseases such as lordosis and kyphosis are occurred lumbar and thorax segment and the apex of curvature appears the specified segment such as L3 and T6/T7. Therefore, the kinematic analysis of specified segment which is subdivided with respect to the apex of curvature as well as the analysis of whole segment such as lumbar is appropriate to estimate the rehabilitation and diagnosis of back pathological patients. Six healthy male subjects exhibiting no back pathology were participated in this study. Video data was collected with a 6-camera Vicon motion analysis system (Oxford Metrics Limited, Oxford, UK). The developed kinematic model was verified based on the previously published studies. Following the results, the range of peak-to-peak motion in the thorax (approximately 2.6 degrees) was significantly less than the other segment motions and the maximum variation was approximately 6 degrees between the lower lumbar and pelvis. This study expects to be used as a normal man’s database to discriminate the diseases of patients and to predict injury in the general industrial workplaces and agricultural conditions.

Study on the diagnostic system of scoliosis by using infrared camera

In this study, the radiation generated in the diagnosis of scoliosis, to solve the problems by using an infrared camera and an optical marker system that can diagnose scoliosis developed. System developed by the infrared camera attached to the optical spinal curvature is recognized as a marker to shoot the angle between the two optical markers are measured. Measurement of angle, we used the Cobbs Angle method used in the diagnosis of spinal scoliosis. We developed a software to be able to output to the screen using an infrared camera to diagnose spinal scoliosis. Software is composed of camera output unit was manufactured in Labview, angle measurement unit, in Cobbs Angle measurement unit. In the future, kyphosis, Hallux Valgus, such as the diagnosis of orthopedic disorders that require the use of a diagnostic system is expected case.

Relationship between Endurance Times and Frequency Parameters in Surface EMG during Isotonic Contraction Exercises

Abstact: Previous investigators have shown that the frequency compression is related to the muscle fatigue and thedecreasing conduction velocity of muscle fibers. The aim of the present study was to investigate the relationshipbetween endurance times and frequency parameters such as mean power frequency and median frequency in thesurface EMG signal during isotonic contractions. Eight healthy subjects performed voluntary isotonic contractionsof biceps Brachii muscle until their endurance times which were determined when the subject could no longer followthe contraction cycle. The regressive slopes of mean power frequency and median frequency were used to describethe frequency compression of the surface EMG signal, and to test the predictability of endurance time. As resultsof experiment, significant correlations were found between endurance time and the regressive slopes of mean powerfrequency and mean frequency computed over 50%Tend of endurance time.Key words: isotonic contraction, frequency compression, endurance time, mean power frequency, medianfrequency

Security analysis on commercial online music streaming service and countermeasures

Nowadays, the music industry is moving from analog to digital. Most of the big portal sites provide commercial online music streaming services. In this paper, we analyzed the security of the Korean commercial online music streaming services which are provided by the Koreas major portal sites(Dosirak, Cyworld, and Naver). We will show attacks on commercial online music streaming services that lead to an infringement of the copyright and we will also propose countermeasures for online commercial music streaming services.

Tibiofemoral Kinematic Analysis Using Contact Model during Normal Gait

The geometry of the articular surface is extremely important in kinematic analysis, and the 6-DOF joint model is required for an accurate understanding of the functionality of the knee joint in vivo. However, only a few previous studies have utilized the 6-DOF knee joint model, but even in these studies the geometry of the articular surface has been simplified. Thus, we developed a 6-DOF contact model of the human knee joint with realistic geometry, approximated by a non-uniform B-spline, and conducted tibiofemoral kinematic analysis during normal gait using the contact model. The contact point on the femoral condyle shifted posteriorly with knee flexion. In addition, the contact area of the medial condyle was larger than that of the lateral condyle. These results were reasonably consistent with the results of previous studies. According to the results of the tibiofemoral kinematic analyses of six healthy male subjects, the standard deviation of the contact points ranged from ± 0.0145 cm at a 15° flexion to ± 0.1412 cm at 40° on the medial condyle and from ± 0.0046 cm at a 15° flexion to ± 0.1793 cm at 40° on the lateral condyle. The contact points had a very similar pattern as a whole, although six subjects exhibited different gait pattern except for flexion/extension.

Kinetic Analysis of Kneeling Combined with twisting

In contrast to most Western people, Korean has almost seated lifestyle which causes arthritis in joint of the lower-limb of human body. Especially agricultural work in Korea requires squatting, kneeling, and bending postures, each of which are known as one of the sources of musculoskeletal disorder. About 80% of Korea agricultural workers complained of musculoskeletal disorder following the rural resource development institute in 2003 and 47.9% of them suffered knee pain. However, clear understanding of the pain related on the lower-limb joint has not been known yet. The objective of this study was to provide kneeling effect combined with twisted activities increasing rotational angle of the upper-limb and distance between body and hands based on kinetic data. Five male volunteers performed bending and squatting pose with wrenching. In order to calculate knee joint moments, Kinematics data was acquisition by motion capture system and force plate. Following the results, knee joint moments at squatting posture are greater than at standing posture. The moments are increased during at squatting postures with twisting of the body behind the back than with no twisting.

A Study on Chronic Glomerulonephritis Discrimination of Clinical Urine Analysis Data Using Neural Network

Chronic glomerulonephritis (CGN), which is caused by an inflammation of the kidney, can be diagnosed via urine, X-ray and biopsy. The objective of this paper was to present an method for the automatic discrimination of clinical test data of CGN patients via a urine analyzer, independently of an inspector’s visual inspection, using both statistical methods and a neural network. 10 parameters on a urine strip pad were utilized in order to diagnose disease during the urine test. The indicators of strip pads explain the meanings of the reacted color levels of urobilinogen, glucose, ketones, bilirubin, protein, nitrite, pH, occult blood, specific gravity and leukocytes. In order to detect CGN using the neural network, 4 parameters which are without statistic significance regarding CGN are removed via chi-square and t-tests. The input layer of the neural network consists of a reduced number of 6 parameters and the output layer is used to determine whether or not the given sample is dispositive for CGN. The learning process involved training with the data from 73 normal and 66 CGN patients. The validation set consisted of 50 normals and 50 patients, and was not used in the training set. The neural network was able to discriminate correctly in 96 percent of the normal patients and 94 percent of the CGN patients. Tests of statistic significance and the application of such a neural network appear to be quite effective with regard to the discrimination of CGN.

The Effect of Swing Plane Area with Respect to Swing Velocity in Golf Swing

A golf swing is an exceedingly complex motion, which requires power, accuracy, and consistency. Power, however, is probably the most salient factor in the swing, as power is the factor most closely associated with swing velocity at impact. Thus, power is often the subject of focus in studies designed to improve swing velocity. Many factors — including weight transfer, x-factor, release time, etc. - ultimately contribute to swing velocity in the golf swing, but very little literature exists regarding the relationship between the swing plane area and swing velocity. In this study, then, we have analyzed the golf swing motion of pro golfers using 6 infra-red cameras and 2 force platforms. A relationship has previously been established between swing plane area and swing velocity in golf swing. So, we have presented a new factor — the swing plane area - in order to determine a method for improving swing velocity. We believe that the results of this study may potentially prove useful for golfers and golf coaches, especially in the area of performance analysis.