• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.5
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• pp.391-404
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• 2009

A small hydropower plant(SHP) using cooling water discharged from the power plant was constructed in Samcheonpo. This study presents predicted and measured hydrological data in the construction process of small hydropower plant in order to evaluate characteristics of water level variation of cooling water discharge channel which is a key factor in the design of SHP since the water level rise of channel is related to impact on circulating water system of the existing power plant. Various methods were applied for prediction of water level variation in the design stage from simple empirical formula to sophisticated 3-dimensional CFD method. Measured results reveal that mean value was similar between measured and predicted, but measured results were larger than predicted in deviation. Moreover, simple formula, i.e. standard weir equation and Honma equation, were more useful before installation of SHP, but sophisticated methods during operation of SHP.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2511-2516
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• 2012

This paper have analyzed the change of threshold voltage for conduction path of double gate(DG) MOSFET. The threshold voltage roll-off among the short channel effects of DGMOSFET have become obstacles of precise device operation. The analytical solution of Poisson's equation have been used to analyze the threshold voltage, and Gaussian function been used as carrier distribution to analyze closely for experimental results. The threshold voltages for conduction path have been analyzed for device parameters such as channel length, channel thickness, gate oxide thickness and doping concentration. Since this potential model has been verified in the previous papers, we have used this model to analyze the threshold voltage. Resultly, we know the threshold voltage is greatly influenced on the change of conduction path for device parameters of DGMOSFET.

• Journal of Biosystems Engineering
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• v.26 no.1
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• pp.29-38
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• 2001

A navigation system was developed for autonomous guidance of a combine. It consisted of a DGPS, a machine vision system, a gyro sensor and an ultrasonic sensor. For an autonomous operation of the combine, target points were determined at first. Secondly, heading angle and offset were calculated by comparing current positions obtained from the DGPS with the target points. Thirdly, the fuzzy controller decided steering angle by the fuzzy inference that took 3 inputs of heading angle, offset and distance to the bank around the rice field. Finally, the hydraulic system was actuated for the combine steering. In the case of the misbehavior of the DGPS, the machine vision system found the desired travel path. In this way, the combine traveled straight paths to the traget point and then turned to the next target point. The gyro sensor was used to check the turning angle. The autonomous combine traveled within 31.11cm deviation(RMS) on the straight paths and harvested up to 96% of the whole rice field. The field experiments proved a possibility of autonomous harvesting. Improvement of the DGPS accuracy should be studied further by compensation variations of combines attitude due to unevenness of the rice field.

• Convergence Security Journal
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• v.7 no.2
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• pp.17-25
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• 2007

In this paper, an algorithm that provisions proportional differentiation of packet delays is proposed with an objective for enhancing quality of service (QoS) in future packet networks. It features an adaptive scheme that adjusts the target delay every time slot to compensate the deviation from the target delay which is caused by the prediction error on the traffic to be arrived in the next time slot. It predicts the traffic to be arrived at the beginning of a time slot and measures the actual arrived traffic at the end of the time slot. The difference between them is utilized to the delay control operation for the next time slot to offset it. As it compensates the prediction error continuously, it shows superior adaptability to the bursty traffic as well as the exponential rate traffic. It is demonstrated through simulations that the algorithm meets the quantitative delay bounds and shows superiority to the traffic fluctuation in comparison with the conventional non-adaptive mechanism. The algorithm is implemented with VHDL on a Xilinx Spartan XC3S1500 FPGA and the performance is verified under the test board based on the XPC860P CPU.

• Journal of Chest Surgery
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• v.33 no.8
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• pp.623-629
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• 2000

Background: There has been controversy over the prevalence of recoarctation in infants treated by subclavian flap aortoplasty(SFA) for coarctation of the aorta. To assess the rate of recurrence of coarctation after SFA, we reviewed the surgical results of SFA in infants with coarctation of the aorta. Material and method: Between 1986 and 1998, a total of 25 patients less than 1 year of age(12 neonates and 13 infants) underwent SFA for aortic coarctation. Age at operation was 3.0$\pm$3.0 months(mean $\pm$ standard deviation); mean weight was 5.0$\pm$1.4kg. Classic SFA was performed in 20 patients, reversed SFA in 2 patients, subclavian artery reimplantation in 2 patients and the combined resection-flap aortoplasty in one. Result: The aortic clamping time ranged from 20 to 88 minutes(mean 35.8 minutes). There were one operative death and two late deaths. There was no case of paraplegia or left arm ischemia in complications. Twenty-one(84%) of 24 hospital survivors were followed for 26.0$\pm$24.0 months. The risk of recoarctation in neonates(33.3%) was a little greater than infants(25.0%) without statistical significance. Conclusion: This study revealed that SFA resulted a relatively high incidence of recarctation in infants. It is desirable to select other methods of surgical treatment(combined resection-flap aortoplasty, extended end-to-end repair etc.) for severe isthmic coarctation or hypoplasia of the distal aortic arch in infants, instead of choosing SFA indiscriminately.

• Journal of Chest Surgery
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• v.30 no.8
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• pp.815-818
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• 1997

Prosthetic valve endocarditis(PVE), although uncommon, is associated with significant mortality if the infection spreads into the paravavular structures with later abscess formation. However, combined antibiotic and surgical treatment is often successful. Accurate diagnosis by on echocardiography, effective myocardial protection during operation and increased surgical experience have improved the short-term and long-term outcomes for patients with PVE. A 35-year-old male had a history of replacement of aortic and mitral valve, and tricuspid annuloplasty on August 1994, was admitted due to sudden onset of aphasia, leftward deviation of both eyeballs and spiking fever and diagnosed of having PVE by echocardiography. Reoperation was done after 6weeks of antibiotic treatment. On the operative field, we could notice circumferential vegetation along aortic valve annulus, paravalvular leakage and abscess pocket. The mitral valve amlulus was healthy. The patient underwent redo aortic valve replacement using cryopreserved aortic homograft after radical debridement of infected issue. During the follow up of 7 months period the homograft was well functioning without recurrence of symptoms.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.3
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• pp.265-274
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• 2015

International organizations and classification societies established rules and regulations to which shipbuilders and ship operators should comply during design, construction, even operation keeping from hazard to life of crews and ocean environment. Hence, rules and regulations could be guidelines for design and construction of ship sometimes. In practical wise, ship structure designers be predisposed to design lightest and easy-to-product structures which satisfy rules and regulations. Therefore, changes of rules and regulations are remarkably important issue to related industries. In 2006, IACS established and released Common Structural Rules for Bulk Carrier and Common Structural Rules for Double Hull Oil Tanker. These CSRs are consolidated and unified rules of class society's rules. But these two rules are different from each other. IACS has plan to release unified rule of two ship type called Harmonized Common Structural Rule for Bulk Carriers and Oil Tankers. This new rule will be effective from July 2015. Hence, bulk carrier and double hull oil tanker whose contract date is on and thereafter July 2015 should be complied with CSR-H. Therefore, it is highly important to be aware of consequences and cause of consequences with respect to CSR-H. The object of this research is to compare requirements of structure scantling in way of midship area for selected target ship according to CSRs and CSR-H and to analysis cause of deviation between two rules.

• Journal of Biomedical Engineering Research
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• v.37 no.3
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• pp.105-111
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• 2016

Introduction: Surgical robot is the alternative instrument that substitutes the difficult and precise surgical operation; should have intuitiveness operationally to transfer natural motions. There are limitations of hand motion derived from contacting mechanical handle in the surgical robot master interface such as mechanical singularity, isotropy, coupling problems. In this paper, we will confirm and verify the feasibility of intuitive Non-restraint master interface which tracking the hand motion using infra-red camera and only 3 reflective markers without the hardware handle for the surgical robot master interface. Materials & methods: We configured S/W and H/W system; arranged 6 infra-red cameras and attached 3 reflective markers on hands for measuring 3 dimensional coordinate then we find the 7 motions of grasp, yaw, pitch, roll, px, py, pz. And we connected Virtual-Master to the slave surgical robot(Laparobot) and observed the feasibility. To verify the result of motion, we compare the result of Non-restraint master and that of clinometer (and protractor) through measuring 0~180 degree, 10degree interval, 1000 samples and recorded standard deviation stands for error rate of the value. Results: We confirmed that the average angle values of Non-restraint master interface is accurately corresponds to the result of clinometer (and protractor) and have low error rates during motion. Investigation & Conclusion: In this paper, we confirmed the feasibility and accuracy of 3D Non-restraint master interface that can offer the intuitive motion of non-contact hardware handle. As a result, we can expect the high intuitiveness, dexterousness of surgical robot.

• Journal of the Korean Applied Science and Technology
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• v.37 no.3
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• pp.543-550
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• 2020

This study is Stress, Stress Symptoms and Turnover Intention in Nurses. Method: Data was accumulated from 183 nurses serving at least more than one year in 500 bed order hospitals during the period of three months from October 1, to December 30, 2018. Results: Data were analyzed using SPSS 22.0 program. Frequency, percentage, mean, standard deviation, t-test, ANOVA and correlation were used. In the present study, the perceived stress of the subjects was 95.05 ± 10.21, stress symptoms were 200.02 ± 50.73 points, turnover intention was 39.591 ± 8.3 points. As the perceived stress increased, the stress symptoms and turnover intention increased appear. Conclusion: As a result of this study, it is necessary to provide a multidisciplinary support system to reduce the perceived stress of the nurse. The results of this study can be useful as basic data for efficient operation of nursing personnel.

• The Korean Journal of Rehabilitation Nursing
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• v.6 no.2
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• pp.226-238
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• 2003

This study was started for the purpose of providing the basic data for continous managment of kidney transplantation patients after discharge. This study was conducted on 180 patients who received renal transplants at three hospital( B, M, P) pusan, korea. The data collection was done for june 1, to August 31, 2002. General characteristics, renal transplantaton characteristics, physical characteristics, the level of compliance and the degree of educational demand were done by the number and percentage, the mean, standard deviation. The level of compliance and educational demand followed by the characteristics of general and kidney transplantation were analyzed by t-test and ANOVA. The result were as fallows; 1. Man was higher than woman such as 60.0%, Mean age was 42.5 years old, Average total duration of after operation was 5.5 years. 2. Cases of systolic blood pressure over 140mmHg were 10.0%, cases of diastolic blood pressure over 90mmHg were 22.8% and obesity factor in BMI was 15.6%. The person who daily water intake amount is 5000cc was 0.6%, the case that daily urine output is below 1000cc was 8.9%, and the case that urine output is zero was 0.6%. 3. The mean score of compliance was 77.47 point, The score in medication part was highest such as 4.67 point, that in stress situation was lowest such as 3.50 point. 4. The average score of educational demand was 154.02 point, and physical state part was 4.36 points highest, activation part was 3.48 points lowest. As a role of nurse Confirmation of compliance is very important encourage to make good through regular hospital visitation, point out the noncompliance part and then increase compliance of renal transplantation patient As well there will be maintain the normal kidney function to satisfy educational demand through continous education.