• Journal of Biomedical Engineering Research
• /
• v.23 no.1
• /
• pp.1-8
• /
• 2002

Atrial fibrillation(AF). chronic or paroxysmal is the most frequent arrhythmia in human subjects Duration of P wave in signal-averaged electrocardiography(SAECG) reflects intra-atrial conduction time and therefore. could be used as an electrophysiological marker for atrial conduction chance at the earthy stave. So we apply the analysis method using SAECG to diagnose Paroxysmal atrial fibrillation(PAF) . Subjects Participated for the study consisted of two groups: a control group(n=34) of normal healthy volunteers and a group of AF Patients(n=38) with a documented history of PAF but no other history of cardiac disease. We evaluated the effect of several filtering and determination methods to find the starting and ending feints of the P wavy on its duration. To increase the measurement reliability of P wave duration. the automatic detection method was proposed. Also. to increase the detection rate for PAF risk, the decision threshold value was optimized using receiver operation characteristics(ROC) curve. Results showed that the highest statistical difference (p〈0.001) of the P wane duration between controls and subjects was obtained at the Processing condition, using absolute threshold vague(8.75 $\mu N$) , a least mean square(LMS) high pass filter and 30 Hz cutoff frequency. The most outstanding difference(sensitivity 88 % specificity 64.4 %) between controls and subjects was obtained at the decision threshold value of 112 ms.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.39 no.2
• /
• pp.128-136
• /
• 2002

In this paper, we developed an acoustic echo canceller in real-time using TeakLite DSP Core, which will be placed in the vocoder chip of a mobile handset. Considering the limited computational capacity given to the acoustic echo canceller in a vocoder chip, we employed a FIR-type adaptive filter using a conventional NLMS algorithm. To begin with, we designed and implemented an acoustic echo canceller with floating-point format C-source code, and then converted it into fixed-point format through integer simulation. Then we programmed and optimized it in the assembler level to make it run ill real-time. After optimization procedure, the implemented echo canceller has approximately 624 words of program memory and 811 words of data memory. With 8 KHz sampling rate and 256 filter taps in the echo canceller that corresponds to 32 msec of echo delay, it requires 14.12 MIPS of computational capacity. For coverage of 16 msec echo delay, i.e., 128 filter taps, 9 MIPS is requited.

• Journal of the Korea Computer Graphics Society
• /
• v.17 no.3
• /
• pp.43-50
• /
• 2011

We present a trade-off technique for fast but qualitative planar shape deformation using a layered mesh. We construct a layered mesh that is embedding a planar input shape; the upper-layer is denoted as a control mesh and the other lower-layer as a shape mesh that is defined by mean value coordinates relative to the control mesh. First, we try to preserve some shape properties including user constraints for the control mesh by means of a known existing nonlinear least square optimization technique, which produces deformed positions of the control mesh vertices. Then, we compute the deformed positions of the shape mesh vertices indirectly from the deformed control mesh by means of simple coordinates computation. The control mesh consists of a small number of vertices while the shape layer contains relatively a large number of vertices in order to embed the input shape as tightly as possible. Since the time-consuming optimization technique is applied only to the control mesh, the overall execution is extremely fast; however, the quality of deformation is sacrificed due to the sacrificed quality of the control mesh and its relativity to the shape mesh. In order to change the deformation behavior and consequently to compensate the quality sacrifice, we present a method to control the deformation stiffness by incorporating the orientation into the user constraints. According to our experiments, the proposed technique produces a planar shape deformation fast enough for real-time applications on limited embedded systems such as cell phones and tablet PCs.

• Korean Journal of Applied Biomechanics
• /
• v.15 no.3
• /
• pp.161-173
• /
• 2005

Recently among several tennis techniques forehand stroke has been greatly changed in the aspect of spin, grip and stance. The most fundamental factor among the three factors is the stance which consists of open, square and closed stance. The purpose of this study was to investigate the relations between the segments of the body, the three dimensional anatomical angle according to open stance patterns during forehand stroke in tennis. For the movement analysis three dimensional cinematographical method(APAS) was used and for the calculation of the kinematic variables a self developed program was used with the LabVlEW 6.1 graphical programming(Johnson, 1999) program. By using Eular's equations the three dimensional anatomical Cardan angles of the joint and racket head angle were defined 1. In three dimensional maximum linear velocity of racket head the X axis showed $11.41{\pm}5.27m/s$ at impact, not the Y axis(horizontal direction) and the z axis(vertical direction) maximum linear velocity of racket head did not show at impact but after impact this will resulted influence upon hitting ball It could be suggest that Y axis velocity of racket head influence on ball direction and z axis velocity influence on ball spin after impact. the stance distance between right foot and left foot was mean $74.2{\pm}11.2m$. 2. The three dimensional anatomical angular displacement of shoulder joint showed most important role in forehand stroke. and is followed by wrist joints, in addition the movement of elbow joints showed least to the stroke. The three dimensional anatomical angular displacement of racket increased flexion/abduction angle until the impact. after impact, The angular displacement of racket changed motion direction as extension/adduction. 3. The three dimensional anatomical angular displacement of trunk in flexion-extension showed extension all around the forehand stroke. The angular displacement of trunk in adduction-abduction showed abduction at the backswing top and adduction around impact. while there is no significant internal-external rotation 4. The three dimensional anatomical angular displacement of hip joint and knee joint increased extension angle after minimum of knee joint angle in the forehand stroke, The three dimensional anatomical angular displacement of ankle joint showed plantar flexion, internal rotation and eversion in forehand stroke. it could be suggest that the plantar pressure of open stance during forehand stroke would be distributed more largely to the fore foot. and lateral side.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.11
• /
• pp.5019-5026
• /
• 2011

The purpose of this study was to investigate the effect of the increased sympathetic outflow on the changes of muscle tone and central nervous system excitability in the chronic stroke patients. This study was conducted from October 12th 2009 to December 4th 2009. 30 patients with chronic hemiplegia for at least 6 months were participated. Before and during the mental arithmetic, static handgrip and post-handgrip ischemia tasks, the central nervous system action potentials and global synkinesis level were compared. The central nerve action potentials were measured with H/Mmax ratio and V/Mmax ratio. To obtain global synkinesis level, surface electromyography data were digitized, processed to root mean square. In our study, The global synkinesis level during knee flexion and extension was decreased in the mental arithmetic and in the post-handgrip ischemia task(p<.05) but not in the grip task. Also, V/Mmax ratio was decreased all in the three task(p<.05). In conclusion, we know that the central nervous system excitability and the muscle tone in chronic hemiplegic patients were decreased by the increased sympathetic outflow.

• Food Engineering Progress
• /
• v.15 no.4
• /
• pp.324-331
• /
• 2011

Hyperspectral reflectance imaging technology was used to predict internal quality of cherry tomatoes with the spectral range of 400-1000 nm. Partial least square (PLS) regression method was used to predict firmness, sugar content, and acid content. The PLS models were developed with several preprocessing methods, such as normalization, standard normal variate (SNV), multiplicative scatter correction (MSC), and derivative of Savitzky Golay. The performance of the prediction models were investigated to find the best combination of the preprocessing and PLS models. The coefficients of determination ($R^{2}_{p}$) and standard errors of prediction (SEP) for the prediction of firmness, sugar content, and acid content of cherry tomatoes from green to red ripening stages were 0.876 and 1.875kgf with mean of normalization, 0.823 and $0.388^{\circ}Bx$ with maximum of normalization, and 0.620 and 0.208% with maximum of normalization, respectively.

• Food Engineering Progress
• /
• v.15 no.2
• /
• pp.136-142
• /
• 2011

The objective of this research was to classify intact soybeans and foreign objects using near-infrared (NIR) spectroscopy. Intact soybeans and foreign objects were scanned using a NIR spectrometer equipped with scanning monochromator. NIR spectra of intact soybeans and foreign objects in the wavelength range from 900 to 1800 nm were collected. The classification of intact soybeans and foreign objects were conducted by using partial least-square discriminant analysis (PLS-DA) and soft independent modelling of class analogy (SIMCA) multivariate methods. Various types of data pretreatments were tested to develop the classification models. Intact soybeans and foreign objects were successfully classified by the PLS-DA prediction model with mean normalization pretreatment. These results showed the potential of NIR spectroscopy combined with multivariate analysis as a method for classifying intact soybeans and foreign objects.

• Journal of Environmental Health Sciences
• /
• v.48 no.4
• /
• pp.227-235
• /
• 2022

Background: Abandoned metal mines are classified as vulnerable areas with the highest level of soil contamination among risk regions. People living near abandoned metal mines are at increased risk of exposure to toxic metals. Objectives: This study aimed to evaluate the correlation between soil contamination levels in areas around abandoned metal mine and the blood lead levels of local residents. Moreover, we assess the possibility of using soil contamination levels as a predictive indicator for human exposure level. Methods: Data from the Survey of Residents around Abandoned Metal Mines (2013~2017, n=4,421) and Investigation of Soil Pollution in Abandoned Metal Mines (2000~2011) were used. A random coefficient model was conducted for estimation of the lower level (micro data) of the local resident unit and the upper level (macro data) of the abandoned metal mine unit. Through a fitted model, the variation of blood lead levels among abandoned metal mines was confirmed and the effect of the operationally defined soil contamination level was estimated. Results: Among the total variation in blood lead levels, the variation between abandoned mines was 18.6%, and the variation determined by the upper-level factors such as soil contamination and water contamination was 8.1%, which was statistically significant respectively. There was also a statistically significant difference in the least square mean of blood lead concentration according to the level of soil contamination (p=0.047, low: 2.32 ㎍/dL, middle: 2.38 ㎍/dL, high: 2.59 ㎍/dL). Conclusions: The blood lead concentration of residents living near abandoned metal mines was significantly correlated with the level of soil contamination. Therefore, in biomonitoring for vulnerable areas, operationally defined soil contamination can be used as a predictor for human exposure level to hazardous substances and discrimination of high-risk abandoned metal mines.

• Clinical and Experimental Pediatrics
• /
• v.46 no.11
• /
• pp.1118-1123
• /
• 2003

Purpose : Henoch-$Sch{\ddot{o}}nlein$ purpura(HSP) is a systemic vasculitis, characterized by cutaneous purpura, abdominal pain, arthralgia and renal involvement. The clinical features of HSP have been reasonably well documented but there are still many gaps in our understanding of HSP. The aim of this study was to present the clinical features of 125 children with HSP and compare them with previous reports, placing particular emphasis on clinical information. Methods : We collected the clinical data of 125 patients with acute HSP who visited Chungbuk National University Hospital from March 1992 to April 2002. Data were expressed as the mean or $mean{\pm}SD$ and statistical analysis was performed using Chi-square approximation. P<0.05 was considered as significant. Results : The patient population consisted of 87 boys and 38 girls ranging in age from one to 14 years. HSP occurs throughout the year, but this study shows seasonal skewing, with most patients presenting from fall through spring and a paucity of cases in summer. All patients had non-thrombocytopenic purpura concentrated on the buttocks and lower extremities. Purpuric lesions were also scattered on the arms and occaisionally on the face and ears, but the trunk was largely spared. A recurrence of purpura was defined as the reappearance of a rash or other symptoms following resolution of disease for at least two weeks. The mean number of recurrences was 0.51. Eighty eight patients(70.4%), 18 patients(14.4%) and 67 patients(53.6%) complained of abdomianl pain, gastrointestinal bleeding and arthralgia, respectively. Nephritis occurred in 48(38.4%) patients. Fifteen boys (17.2%) developed epididymitis. Neurologic features occurred in 13(10.4%) and two(15%) of these were seizures. Conclusion : HSP all showing purpura as defined is characterized by various clinical features, including abdominal pain, arthralgia, epididymitis and nephritis which could occur before the appearance of purpura. Therefore, we suggest that the possibility of HSP should be considered in children before invasive procedures, even if the above symptoms and signs present without purpura.

• Korean Journal of Agricultural Science
• /
• v.14 no.2
• /
• pp.232-247
• /
• 1987

Three rice varietis, Dongjinbyeo, Daecheongbyeo and Chucheongbyeo, which are leading cultivars in the Chungnam area, were planted to determine their effects of mixture on the plant characteristics and the blast occurrence. The summary obtained is as follows; 1. The heading dates of each cultivars were not affected by the mixing culture. Only a day was delayed in heading date of Chucheongbyeo under commonly standard fertilizer level. 2. The effects of cultivar mixture on the plant height was high when low level of fertilizer were applied. Of the cultivar mixture, the mixing of Dongjinbyeo and Daecheongbyeo shoed 5.1% of plant height increase. The effects of mixture on the tillering number were apparent only under the standard fertilizer level. The mixture of Dongjinbyeo and Chucheongbyeo was effective in increasing the tillering number up to 5.7% over mean tillering number of each cultivars. 3. The stem height tended to increase as the fertilizer level increased and the effects of cultivar mixture on the stem height was high. The stem height of mixture of Dongjinbyeo and Daecheongbyeo was highest compared with other mixture cropping. On the contrary, the panicle length was shortened as the fertilizer level decreased and cultivars were mixed. Among the cultivar mixtures, the mixture of Dongjinbyeo and Daecheongbyeo showed the most effectives of increasing the panicle length. 4. The total dry weight of mixed and pure cultivars were compared. The mixture of two cultivars was effective in increasing the dry weight of rice upto 3.5% over the average of dry weight of each cultivars. When three cultivars were mixed, there were 8.5% of dry weight increase over not mixed cultivars. The effects of mixture on the dry weight were more apparent under standard fertilizer level. 5. The rates of Neck and Node and Branch Blast occurrence were reduced when cultivars were mixed, and their reduction rates were 11.7% and 14.0%, respectively. The occurrence of Blasts was also decreased under the lowest fertilizer level than the standard fertilizer level. The least Blast occurrence was obtained when Dongjinbyeo and Daecheongbyeo were mixed cropped. 6. Significantly high number of spikelets of per square meter was observed when Chucheongbyeo and Dongjinbyeo were mixed. However, the spikelets of panicle were the lowest when Chucheongbyeo and Dongjinbyeo were mixed. The number of panicles per square meter was increased as the fertilizer levels increased, while the number of spikelets per panicle increased as the fertilizer level decreased. 7. The effects of mixture on the maturing were apparent regardless of the fertilizer level. The 1000 grain weight was higher when lower level of fertilizer was applied. The effects of cultivar mixture on the 1000 grain weight were more apparent in the plots of Chucheongbyeo and Dongjinbyeo mixture and three cultivar mixture. 8. The grain yield increased when cultivars mixed. The increment under mixing cropping was 4.6% over mono cropping. The effects of cultivar mixture on the yield increase were more apparent under lower levels of fertilizer application. The highest yield increase was obtained when Chucheongbyeo and Daecheongbyeo were mixed, and the rate of yield increase was 6.8% over mono-cropping. 9. The grain yield was highly correlated with number of panicles per square meter and dry weight. There was not any significant relationships found among grain yield, spikelets of panicle and ripening percentage.