• 대한기계학회논문집
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• 제16권7호
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• pp.1234-1243
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• 1992

본 연구에서는 국부적인 퍼지제어 셀(fuzzy control cell:cell)을 도입하여 계산량 감소를 달성하고, 추론과정을 선형근사화한 조직적인 설계를 통하여 선형제어 이론을 FLC의 실용적인 면에 접목하고자 한다. 이를 위하여, 확률밀도함수 형태의 멤버쉽함수(membership function)와 선형화된 제어공간이 얻어지도록 전반적인 제어방 책을 결정한 다음, 주어진 상태에 가장 지배적(dominant)인 규칙을 갖는 몇 개의 대표 점을 찾아서 그 점들로 구성된 퍼지제어 셀을 생성하고, 퍼지연산을 생성된 셀에서만 수행하여 알고리즘과 계산을 단순화시킨다. 평가기준을 공평함에 두어서 조건부연결 어 'AND'에 T-norm인 대수곱을 적용하여 적합도를 취하고, 규칙들의 작용이 병렬발화 라는 관점으로 규칙연결어 'ALSO'는 'AND'의 공액인 'OR'에 해당되는 대수합연산 대신 에 확률측도와 유사한 산술평균을 적용하여 퍼지추론을 한다. 그리고, 각각의 제어 규칙에 대하여 퍼지추론한 결과와 그것의 평균중심을 곱하여 통합한 후, 무게중심법으 로 역퍼지화하여 일반화된 제어값을 얻는다. 이 값을 PID제어기를 이용하여 구현한 디지틀 보상기를 통과시켜 시스템에 한 제어를 얻는 조직적인 방법을 제안한다.

• Journal of Preventive Medicine and Public Health
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• 제41권2호
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• pp.107-114
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• 2008

Objectives : The aim of this study is to investigate the association between obesity indices(body mass index, weight, waist-hip ratio and waist circumference) in adolescents and the carotid intima-media thickness (C-IMT) in early adulthood. We also wanted to identify the best predictor for C-IMT among these obesity indices. Methods : This study used community-based prospective cohort study, known as the Kangwha Study, and the data we used were from subjects who were 16-years old in 1996 (defined as "adolescence") and 25 years-old in 2005 (defined as "early adulthood"). The 256 subjects (113 men and 143 women) who were used for analysis participated in both follow-ups, and they underwent B-mode ultrasonography of the carotid arteries at the early adulthood follow-up. Obesity indices were defined as the body mass index, weight, waist-hip ratio and waist circumference. The C-IMT was defined as the mean of the maximal IMT of each common carotid artery. The C-IMT and obesity indices associations were evaluated via multivariable regression, logistic regression and the receiver-operator characteristic curve analyses. Results : In men, all the obesity indices in adolescence were showed to have statistically significant positive association with C-IMT in early adulthood. However, no such relationship was showed in women. On multiple regression and logistic regression analysis, the waist-hip ratio showed the biggest relationship with the C-IMT among the 4 obesity indices. However, there were no statistical significant differences and no best predictor was found. For the women, the obesity incidences and C-IMT showed no relationships. Conclusions : This study suggested that obesity in adolescence was related to an increase C-IMT in healthy young Korean men.

• 한국항해항만학회지
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• 제40권2호
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• pp.83-87
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• 2016

The maritime industry is expanding at an alarming rate hence there is a perpetual need to improve situation awareness in the maritime environment using new and emerging technology. Tracking is one of the numerous ways of enhancing situation awareness by providing information that may be useful to the operator. The tracking module designed herein comprises determining existing states of high dynamic target warship, state prediction and state compensation due to random noise. This is achieved by first analyzing the process of tracking followed by design of a tracking algorithm that uses ${\alpha}-{\beta}-{\gamma}$ tracking filter under a random noise. The algorithm involves initializing the state parameters which include position, velocity, acceleration and the course. This is then followed by state prediction at each time interval. A weighted difference of the observed and predicted state values at the $n^{th}$ observation is added to the predicted state to obtain the smoothed (filtered) state. This estimation is subsequently employed to determine the predicted state in the next radar scan. The filtering coefficients ${\alpha}$, ${\beta}$ and ${\gamma}$ are determined from a pre-determined value of the damping parameter, ${\xi}$. The smoothed, predicted and the observed positions are used to compute the twice distance root mean square (2drms) error as a measure of the ability of the tracking module to manage the noise to acceptable levels.

• Archives of Plastic Surgery
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• 제33권5호
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• pp.643-647
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• 2006

Purpose: The transverse rectus abdominis myocutaneous(TRAM) flap has become a mainstay of breast reconstruction. The chief disadvantage of the TRAM flap is its potential to create a weakness in the abdominal wall. Nowadays true hernia is less frequent, but bulging that appears at the muscle donor site, or at the contralateral side, or at the epigastric area is still remained as a problem. To prevent this complications, we have used synthetic mesh as well as abdominal muscle plication. Now we report the result of our methods. Methods: We started to use synthetic mesh and muscle plication as supplementary reinforcement for entire abdominal wall, after TRAM flap harvesting, in an attempt to stabilize it and achieve a superior aesthetic result since 2002. We observed complications of TRAM flap donor site, and compared our results (from January, 2002 to January, 2006) with other operator's result (before 2001) at the same hospital in aspect of incidence of abdominal complications. Results: 42 consecutive patients have been performed routine reinforcement with the extended mesh technique and muscle plication from January, 2002 to January, 2006. Mean patient follow up was 25.2 months. No hernia or mesh related infection were encountered and only one patient had a mild abdominal bulging. Nevertheless the our good results, there were no significant statistical differences were observed between two groups. Conclusion: We recommend the using of synthetic mesh and muscle plication for donor site reconstruction after TRAM flap breast reconstruction to improve strength as well as aesthetic quality of the abdominal wall.

• The Korean Journal of Pain
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• 제31권2호
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• pp.87-92
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• 2018

Background: An epidural steroid injection (ESI) is a commonly administered procedure in pain clinics. An unintentional lumbar facet joint injection during interlaminar ESI was reported in a previous study, but there has not been much research on the characteristics of an unintentional lumbar facet joint injection. This study illustrated the imaging features of an unintentional lumbar facet joint injection during an interlaminar ESI and analyzed characteristics of patients who underwent this injection. Methods: From December 2015 to May 2017, we performed 662 lumbar ESIs and we identified 24 cases (21 patients) that underwent a lumbar facet joint injection. We gathered data contrast pattern, needle approach levels and directions, injected facet joint levels and directions, presence of lumbar spine disease as seen on magnetic resonance images (MRI), and histories of lumbar spine surgeries. Results: The contrast pattern in the facet joint has a sigmoid or ovoid contrast pattern confined to the vicinity of the facet joint. The incidence of unintentional lumbar facet joint injection was 3.6%. The mean age was 68.47 years. Among these 21 patients, 14 (66.7%) were injected in the facet joint ipsilaterally to the needle approach. Among the 20 patients who received MRI, all (100%) had central stenosis and 15 patients (75%) had severe stenosis. Conclusions: When the operator performs an interlaminar ESI on patients with central spinal stenosis, the contrast pattern on the fluoroscopy during interlaminar ESI should be carefully examined to distinguish between the epidural space and facet joint.

• 대한치과마취과학회지
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• 제10권1호
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• pp.1-6
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• 2010

Background: Articaine, commercially available in South Korea from 2004, is widely being used for dental treatments. In the surgical extraction of impacted mandibular third molars, one of the most common procedures in oral and maxillofacial surgery, the anesthetic efficacy of 4% articaine and 2% lidocaine, both with 1：100,000 epinephrine, was compared. Methods: A randomized double-blind clinical trial was conducted of 80 patients for bilateral surgical extraction of mandibular third molars with informed consents. One operator carried out the routine surgical procedures using local anesthetic 4% articaine or 2% lidocaine with the same concentration of vasoconstrictor. Latency, duration of anesthesia and the amount of anesthetic solution were recorded. A visual analog scale (VAS) was used to evaluate the intraoperative pain. Results: The pain VAS scores reported similar anesthetic effect with both local anesthetics. Not in the latency of anesthesia and the amount of anesthetic solution, statistically significant difference was found in the mean duration of anesthesia. Conclusions: It was concluded that 4% articaine could offer better or at least the same clinical feasibility compared to 2% lidocaine, particularly in terms of the duration of the local anesthesia for common dental treatments.

• Smart Structures and Systems
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• 제21권5호
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• pp.705-713
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• 2018

High-speed rail (HSR) has been in operation and development in many countries worldwide. The explosive growth of HSR has posed great challenges for operation safety and ride comfort. Among various technological demands on high-speed trains, vibration is an inevitable problem caused by rail/wheel imperfections, vehicle dynamics, and aerodynamic instability. Ride comfort is a key factor in evaluating the operational performance of high-speed trains. In this study, online monitoring data have been acquired from an in-service high-speed train for condition assessment. The measured dynamic response signals at the floor level of a train cabin are processed by the Sperling operator, in which the ride comfort index sequence is used to identify the train's operation condition. In addition, a novel technique that incorporates salient features of Bayesian inference and time series analysis is proposed for outlier detection and change detection. The Bayesian forecasting approach enables the prediction of conditional probabilities. By integrating the Bayesian forecasting approach with time series analysis, one-step forecasting probability density functions (PDFs) can be obtained before proceeding to the next observation. The change detection is conducted by comparing the current model and the alternative model (whose mean value is shifted by a prescribed offset) to determine which one can well fit the actual observation. When the comparison results indicate that the alternative model performs better, then a potential change is detected. If the current observation is a potential outlier or change, Bayes factor and cumulative Bayes factor are derived for further identification. A significant change, if identified, implies that there is a great alteration in the train operation performance due to defects. In this study, two illustrative cases are provided to demonstrate the performance of the proposed method for condition assessment of high-speed trains.

• 대한의용생체공학회:의공학회지
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• 제13권2호
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• pp.133-140
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• 1992

Bioelectrical Impedance method for measuring human body composition is based upon the principle that the electrical conductivity of the fat-free mass (FFM) is far greater than that of the (at. Deter- mination o( impedance was nlade in 30 healthy and obese men aged $40.9{\pm}14.7$yr (mean${\pm}$SD) and 25 healthy and obese women aged $44.0{\pm}10.2$ yr. A commercial impedance body fat analyzer was used with a four electrode arrangement that introduced a painless constant current(ImA at 50 kHz) into the body. Linear relationships were found between impudence values and FFM(r=-0.786) and between weight and FFM(r=0.837). Signigicant increases in the correlation coefficients were ob served when the predicator Hta/z was regressed against FFM(r=0.912) where Ht Is height and Z Is impedance. A linear regression equation, FFM=0.586(Htf/z) +0.317(Weight) -1.674(r=0.977), was found. The correlation coefficient of % body fat between the impedance and infrared methods was 0.898. These data Indicate that the bioelectrical impedance technique is a reliable and valld approach for the estimation of human body composition. This method Is safe, noninvasivr, prouides rapld measure menu, requires little operator skill and subject cooperation, and Os portable. Finally measurement of percent body fat was made possible using both the regression equation and a developed impedance measuring device which measures impedance between wrist and ankle.

• 로봇학회논문지
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• 제13권1호
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• pp.26-30
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• 2018

Planetary global localization is necessary for long-range rover missions in which communication with command center operator is throttled due to the long distance. There has been number of researches that address this problem by exploiting and matching rover surroundings with global digital elevation maps (DEM). Using conventional methods for matching, however, is challenging due to artifacts in both DEM rendered images, and/or rover 2D images caused by DEM low resolution, rover image illumination variations and small terrain features. In this work, we use train CNN discriminator to match rover 2D image with DEM rendered images using conditional Generative Adversarial Network architecture (cGAN). We then use this discriminator to search an uncertainty bound given by visual odometry (VO) error bound to estimate rover optimal location and orientation. We demonstrate our network capability to learn to translate rover image into DEM simulated image and match them using Devon Island dataset. The experimental results show that our proposed approach achieves ~74% mean average precision.

• Journal of Dental Anesthesia and Pain Medicine
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• 제18권1호
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• pp.35-40
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• 2018

Background: The sight of dental injection can bring about severe anxiety in children. Therefore, an alternative method that is convenient, effective, and keeps the needle hidden making it child friendly is necessary. The objective of the study was to compare the efficacy of a camouflaged syringe and conventional syringe on behavior and anxiety in 6-11-year-old children during local anesthesia administration. Methods: The study was a randomized, crossover clinical study including 30 children. Children were separated into two groups. Group 1 consisted of 15 children aged 6-8 years while group 2 consisted of 15 children aged 9-11 years. This study involved two sessions wherein all the children were injected using conventional and camouflaged syringes in separate sessions. Their behavior was assessed using the Faces, Legs, Activity, Cry, Consolability (FLACC) behavior pain scale and anxiety was assessed by measuring changes in pulse rate. Patient and operator preferences were compared. Results: The results showed a lower mean change in pulse rate and FLACC scores in the camouflaged group, suggesting a positive behavior and lesser anxiety with camouflaged syringes than with conventional syringes. Conclusions: The use of camouflaged syringes for anesthesia was demonstrated to be effective in improving the behavior of children and decreasing their anxiety, and is therefore recommended as an alternative to the use of conventional syringes for local anesthesia.