• 한국멀티미디어학회논문지
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• 제16권4호
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• pp.444-452
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• 2013

Operation time of a function or procedure is a thing that always needs to be optimized. Parallelizing the operation is the general method to reduce the operation time of the function. One of the most powerful parallelizing methods is using GPU. In image processing field, one of the most commonly used operations is morphology operation. Three types of morphology operations kernel, na$\ddot{i}$ve, global and shared, are presented in this paper. All kernels are made using CUDA and work parallel on GPU. Four morphology operations (erosion, dilation, opening, and closing) using square structuring element are tested on MRI images with different size to measure the speedup of the GPU implementation over CPU implementation. The results show that the speedup of dilation is similar for all kernels. However, on erosion, opening, and closing, shared kernel works faster than other kernels.

• 한국물환경학회지
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• 제25권2호
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• pp.281-287
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• 2009

Achieved monitoring regularly about fishway that is a intake dam belongings to Kyeongchon for 5 years. Result that achieve monitoring, discovered pressing issue of opening and closing degree of discharge control part in fishway. In this research, analyze discharge relation with fishway and intake sluice and presented operation plan of opening and closing of discharge control part. Investigated necessity intake discharge and benefited area to analyze relation of discharge that is flowed in fishway and discharge escaping by intake sluice. When opened discharge control part step by step gradually, analyzed discharge. Compared with survey discharge making ration curve of fishway and intake sluice using orifice and submerged weir formula. Because operation of intake dam is necessary intake discharge and upriver inflow discharge by time, operation uses by survey discharge and calculated opening discharge of fishway by opening discharge of intake sluice via monthly inflow discharge. To sum up, calculated floodgate opening height of fishway by water level to present maintenance standard of intake dam.

• 대한치과보철학회지
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• 제45권6호
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• pp.769-779
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• 2007

Statement of problem. When TiN coating is applied to the abutment screw, occurrence of greater preload and prevention of the screw loosening could be expected due to decrease of frictional resistance. However, the proper thickness of TiN coating on abutment screw has not been yet reported. Purpose. The purpose of this study is to find out the appropriate TiN coating thickness by evaluating the detorque force and the surface change of titanium abutment screw with various TiN coating thickness. Material and methods. 1. Material Thirty five non-coated abutment screws were prepared for TiN coating. TiN coatings were prepared by Arc ion plating method. Depending on the coating deposition time(CDT), experimental groups were divided into 6 groups(CDT 30min, 60min, 90min, 120min, 150min, 180min) and those of 1 group was not coated as a control group. Each group was made up of 5 abutment screws. 2. Methods FE-SEM(Field Emission Scanning Electron Microscoper) and EDX(Energy Dispersive X-ray Spectroscopy) were used to observe the surface of the abutment screw. Electric scales was used to measure the weight of the abutment screw after the repeated closing and opening of 10 trials. Detorque force was measured with digital torque gauge, at each trial. Results. 1. As the coating deposition time increased, the surface became more consistent and smooth. 2. As for the abutment screws that were TiN coated for more than 60 minutes, no surface change was found after the repeated closing and opening. 3. The TiN coated abutment screws showed less weight change than the non-coated abutment screws. 4. The TiN coated abutment screws showed higher mean detorque force than the noncoated abutment screws. 5. The abutment screw coated for 60 minutes showed the highest mean detorque force. Conclusion. The coating layer of proper thickness is demanded to obtain consistent and smooth coating surface, resistance to wear, and increased detorque force of the abutment screw. In conclusion, the coating deposition time of 60 minutes indicated improved mechanical property, when TiN coating was conducted on titanium abutment screw.

• 한국유체기계학회 논문집
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• 제7권3호
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• pp.14-22
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• 2004

Bileaflet mechanical valves have the complications such as hemolysis and thromboembolism, leaflet damage, and leaflet break. These complications are related with the fluid velocity and shear stress characteristics of mechanical heart valves. The first aim of the current study is to introduce fluid-structure interaction method for calculation of unsteady and three-dimensional blood flow through bileaflet valve and leaflet behavior interacted with its flow, and to overcome the shortness of the previous studies, where the leaflet motion has been ignored or simplified, by using FSI method. A finite volume computational fluid dynamics code and a finite element structure dynamics code have been used concurrently to solve the flow and structure equations, respectively, to investigate the interaction between the blood flow and leaflet. As a result, it is observed that the leaflet is closing very slowly at the first stage of processing but it goes too fast at the last stage. And the results noted that the low pressure is formed behind leaflet to make the cavitation because of closing velocity three times faster than opening velocity. Also it is observed some fluttering phenomenon when the leaflet is completely opened. And the rebounce phenomenon due to the sudden pressure change of before and after the leaflet just before closing completely. The some of time-delay is presented between the inversion point of ventricle and aorta pressure and closing point of leaflet. The shear stress is bigger and the time of exposure is longer when the flow rate is maximum. So it is concluded that the distribution of shear stress at complete opening stage has big effect on the blood damage, and that the low-pressure region appeared behind leaflet at complete closing stage has also effect on the blood damage.

• Journal of Preventive Medicine and Public Health
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• 제34권3호
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• pp.219-227
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• 2001

Objectives : To understand the current status of the opening, closing and relocation of primary medical institutes in Korea and identify the underlying decision factors. Methods : Sources of analyzed data included the medical institutional master file at the National Health Insurance Corporation(1998, 2000) and Regional Statistic Annual Bulletins. To investigate changes including the opening, closing and relocation, a total of primary medicalinstitutions(16,757 in 1998, 19,267 in 2000) were analysed. Results : Between 1998 and 2000, there was a 15.0%(2,510) increase in the number of primary medical institutions and the rate of increase in the rural area was higher than the urban area, and higher for specialty clinics than primary practice. However, these findings did not suggestany improvement in the maldistribution of primary medical institutions. During the time period studied, newly opened and closed primary medical institutions numbered 4,085 and 1,573, respectively. Additionally, institutions thatrelocated numbered 2,729, or 16.3% of all primary medical institutions in operation in 1998. These openings and closings were more frequent among young doctors. As a result of our analysis on the underlying regional factors forrelocation, the factors that were statistically significant were local per capita tax burden and the number of schools per ten thousand persons. !n, the case of institutional factors, movements were significantly associated with gender and the location of primary medical institutions. Conclusions : In order to establish effective long-term intervention for primary medical institutions, further study and monitoring of primary medical institutions and the identification of factors influencing opening location and relocation is necessary.

• 대한의용생체공학회:의공학회지
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• 제36권5호
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• pp.183-190
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• 2015

Invasive blood pressure (IBP) is measured for the patient's real time arterial pressure (ABP) to monitor the critical abrupt disorders of the cardiovascular system. It can be used for the estimation of cardiac output and the opening and closing time detection of the aortic valve. Although the unexplained inflections on ABP make it difficult to find the mathematical relations with other cardiovascular parameters, the estimations based on ABP for other data have been accepted as useful methods as they had been verified with the statistical results among vast patient data. Previous windkessel models were composed with systemic resistance and vascular compliance and they were successful at explaining the average systolic and diastolic values of ABP simply. Although it is well-known that the blood pressure reflection from peripheral arteries causes complex inflection on ABP, previous models do not contain any elements of the reflections because of the complexity of peripheral arteries' shapes. In this study, to simulate a reflection wave of blood pressure, a new mathematical model was designed with four elements that were the impedance of aorta, the compliance of aortic arch, the peripheral resistance, and the compliance of peripheral arteries. The parameters of the new model were adjusted to have three types of arterial blood pressure waveform that were measured from a patient. It was used to find the relations between the inflections and other cardiovascular parameters such as the opening-closing time of aortic valve and the cardiac output. It showed that the blood pressure reflection can bring wide range errors to the closing time of aortic valve and cardiac output with the conventional estimation based on ABP and that the changes of one-stroke volumes can be easily detected with previous estimation while the changes of heart rate can bring some error caused by unexpected reflections.

• 한국토양비료학회지
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• 제45권6호
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• pp.1179-1186
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• 2012

For better understanding of carbon cycle dynamics of an agro-ecosystem, an accurate assessment of seasonal and daily $CO_2$ flux is essential to understand the relationship between various environmental factors and crop productivity. We developed the automatic sliding canopy chamber (ASCC) system that measured continuous net ecosystem productivity (NEP) over whole growing season under the natural meteorological rhythm. The ASCC was composed of two main parts which were sliding part for measuring NEP, and automatic opening and closing chamber (AOCC) for measuring soil respiration (SR) on the soil surface. The ASCC was developed by using open flow method for measuring soil $CO_2$ efflux. The disturbance of natural meteorological condition was minimized by opening the base frames. In the field test with barley (Hordeum vulgare L.), NEP was calculated at $140mg\;CO_2\;m^{-2}h^{-1}$ on a clear day using continuous data and eliminated the possibility of overestimate about 16% using one hour data during the day time. Unlike other small scale chamber system, installation on cropping-field made it possible to take any modifications which might be caused by natural environmental condition.

• 한국정보통신학회논문지
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• 제18권10호
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• pp.2503-2508
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• 2014

본 연구는 진공차단기 기계식 보조접점(MOC)의 구조적인 취약성을 해결하기 위해 전자식 센서 기술을 이용한 전자식 보조접점(EOC) 개발에 선행되어야할 센서의 선정 및 노이즈 시험에 관한 것으로, 기존 기계적 보조접점(MOC)에서 발생하는 반복적인 떨림 및 반동 현상에 의한 접점 오동작을 최소화하는 제품을 개발하는 것을 최종 목표로 하였다. 실험 결과, 차단기 투입 및 개방시 개방시의 써지전압 상승속도가 투입시 보다 4.2배 빠른 것으로 측정되었고, 소음크기는 각각 120dB, 110dB로 측정되었다. 상용주파과전압 60kV를 인가하였을 때 진공차단기 투입 및 개방시 센서에서 출력되는 파형은 일그러짐이 없이 정상적으로 동작됨을 알 수 있었다. 그리고 150kV $1.2{\times}50{\mu}s$의 충격파를 인가하였을 때 센서의 투입 및 개방측 출력접점의 전압파형이 일그러짐이 없이 정상상태를 유지하였으며, 2500A의 전류를 인가하였을 때 자계 잡음을 측정한 결과, 전압파형이 일그러짐이 없이 정상적으로 동작하였다.

• Journal of Oral Medicine and Pain
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• 제22권1호
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• pp.167-181
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• 1997

The aim of this study was to investigate the relationship between velocity and factors which could affect the velocity of mandibular movement. For this study, 30 dental students without any masticatory signs and symptoms and 90 patients with temporomandibular disorders(TMD) were selected as the control group and the patients group, respectively. After determining Angle's classification and lateral guidance pattern of occlusion, clinical examination for TMD was perfomed. Velocity and distance of mandibular movements were recorded with BioEGN, reproducibility index of lateral excursions was evaluated by Pantronic(PRI) and BioEGN (BERI) activity in masticatory and cervical muscles were measured with BioEMG, and occlusal contact time and cross-arch unbalance(Total left-right statistics, TLR) on clenching were recorded with T-scan, respectively. The results of this study were as follows : 1. Velocity in the patients was faster than that in the controls in most mandibular movements, but on wide opening and closing movement, result was reverse. 2. Velocity on closing movements were faster than that on opening movements in the control group and a similar tendency was also shown in the patients group. 3. Patients with muscle disorders showed a tendency to have the highest value of velocity of all diagnostic subgroups, while patients with degenerative joint diseases showed a tendency to have the lowest value. 4. Patients with canine guidance showed a tendency to have the highest value of velocity in three subgroups by lateral guidance pattern, while patients with group function showed a tendency to have the lowest value. 5. BERI had a positive correlation with opening velocity on lateral excursion, while TLR had a negative correlation with opening velocity on swallowing. 6. EMG activity on clenching in masticatory muscles had negative correlation with opening velocity on border movements, and on swollowing, while the activity in rest correlated positively with opening velocity on border movements. 7. There were positive correlation between the velocity and the distance in long components of mandibular trajectory.

• 대한치과교정학회지
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• 제22권1호
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• pp.67-88
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• 1992

The purpose of this study was to investigate the changes of mandibular movement and muscle activity following orthognathic surgery in patients with mandibular prognathism. Lateral cephalogram, M.K.G., E.M.G. recordings were obtained immediately before surgery, and 2 months and 8 months after surgery. Among the patients who received orthognathic surgery, 19(13 men, 6 women) were selected for this study. Statistical analysis for each time interval differences were performed with the SPSS package. The results were as follows: 1. Compared with the pre-operative group (opening 349.7mm/sec, closing 313.1mm/sec), the mean values of the maximum opening and closing velocity in the skeletal Class III surgery group were significantly decreased in the 2 months post-operative (opening 232.9mm/sec, closing 206.9mm/sec), but the values tended to increase in the 8 months post-operative group (opening 280.9 mm/sec, closing 319.1mm/sec). 2. Compared with the pre-operative group (61.7 mm/sec), the maximum velocity of the terminal tooth contact increased in the 2 months (72mm/sec) and 8 months (105.7mm/sec) postoperative groups. 3. In the mean value of vertical freeway space, there was significant difference between the normal group and the pre-operative group, but not between the normal group and the 8 months post-operative group. 4. In the mean values of the maximum opening, the maximum anterio-posterior movement from centric-occlusion, and the lateral deviation from centric occlusion, there was no significant difference between the normal group and the surgery group (the pre-operative and the 8 months post-operative groups). 5. The mature swallowing pattern was 58% in the pre-operative group, but 90% in the 2 months post-operative group, and 63% in the 8 months post-operative group. 6. In the comparison of muscle activity, there was no significant difference between the normal group and the surgery group during the rest position. However, during cotton roll clenching, there was significant difference between the normal group and the pre-operative group, but not between the normal group and the 8 months post-operative group.