• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.10
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• pp.51-57
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• 1999

In this paper, we deal with the problem of controlling an unknown nonlinear dynamical system, using wavelet network. Accurate control of the nonlinear systems depends critically on the accuracy and efficiency of the function approximator used to approximate the function. Thus, we use wavelet network which shows high capability of approximating the functions and includes the free-selection of basis functions for the control of the nonlinear system. We find the dilation and translation that are wavelet network parameters by analyzing the time-frequency characteristics of the controller's input to construct an initial adaptive wavelet network controller. Then, weights is adjusted by the adaptive law based on the Lyapunov stability theory. We apply this direct adaptive wavelet network controller to control the inverted pendulum system which is an nonlinear system.

• Journal of Gastric Cancer
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• v.17 no.3
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• pp.267-276
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• 2017

Purpose: Different esophagojejunostomy (EJ) reconstruction methods are used after totally laparoscopic total gastrectomy (TLTG), and none is considered a standard technique. This report describes a 2-layer hand-sewn EJ technique during TLTG; we also evaluated postoperative morbidity associated with this technique. Materials and Methods: This retrospective cohort study included all consecutive patients who underwent TLTG for gastric cancer (GC) from 2012 to 2016 at 2 affiliated teaching hospitals. All participating surgeons performed standardized intracorporeal 2-layer hand-sewn EJ. Results: We included 51 patients who underwent TLTG for GC and standardized EJ anastomosis. Twenty-seven (53%) were male, and the median age was 60 (36-87) years. The average operative time was $337{\pm}71minutes$ and intraoperative bleeding was $160{\pm}107mL$. There were no open conversions related to EJ. Postoperative morbidity was observed in 9 (17.0%) patients. There was no postoperative mortality. EJ leakage was observed in 2 patients (3.8%) and 1 patient (1.9%) developed EJ stenosis. Patients with leakage were managed non-operatively and the patient with stenosis required endoscopic dilation. The median length of hospital stay was 8 (6-29) days. Conclusions: Two-layer hand-sewn EJ during TLTG for GC is a feasible and safe technique. This method avoids a laparotomy for reconstruction and the disadvantages associated with laparoscopic introduction of mechanical staplers for EJ, and provides an alternative for alimentary tract reconstruction after TLTG.

• Journal of the Korea Society of Computer and Information
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• v.18 no.5
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• pp.35-42
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• 2013

Shot boundary detection is an essential step for efficient browsing, sorting, and classification of video data. Robust shot detection method should overcome the disturbances caused by pixel brightness and object movement between frames. In this paper, two shot boundary detection methods are presented to address these problem by using segmentation, object movement, and pixel brightness. The first method is based on the histogram that reflects object movements and the morphological dilation operation that considers pixel brightness. The second method uses the pixel brightness information of segmented and whole blocks between frames. Experiments on digitized video data of National Archive of Korea show that the proposed methods outperforms the existing pixel-based and histogram-based methods.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.1
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• pp.61-68
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• 1996

In Fibrous dysplasia(FD) of the jaws, the majority of cases can await the cessation of growth before surgical intervention, and it seems prudent to delay surgery whenever possible until growth has ceased. In craniofacial FD, however, the dangers of dystopia, dystopia and loss of vision may require early surgery to prevent or control cranio-orbital complications. Delaying surgery in those circumstances may be significantly detrimental to such patients. Conservative surgical management of FD is widely practised and we advocate an extension to this conservative treatment by combining surgical recontouring with appropriate osteotomies if indicated, to achieve an optimal esthetic and functional results in craniofacial FD. One case will be presented to illustrate the feasiblility of such combined treatment, to report the uneventful healing of osteotomies in the FD of the jaws, and to demonstrate the use of titanium miniplate fixation in dysplastic bone. The other case had expansile disease of the left facial and fronto-temporal bones and osteolytic change left mandible. This patient complained of severe spontaneous bleeding of left mandibular premolar area and it was suspected as central hemangioma of the left mandible and craniofacial FD. Angiogram disclosed generalized dilation of the external carotid artery and its branches, especially terminal branches of the left facial and inferior alveolar arteries. But no specific abnormalities, such as A-V shunt, venous lake, or early venous drainage, was seen. So it was diagnosed craniofacial FD with hypercellularity and generalized bony recontouring was performed via coronal and transoral approaches.

• Management & Information Systems Review
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• v.4
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• pp.257-284
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• 2000

According as the drivers increase who have their cars, the comprehensive studies on the automobile for the traffic safety have been raised as the important problems. Visual Recognition System for radio-controled driving is a part of the sensor processor of Unmanned Autonomous Vehicle System. When a driver drives his car on an unknown highway or general road, it produces a model from the successively inputted road traffic information. The suggested Recognition System of the Road Traffic Safety Information Board is to recognize and distinguish automatically a Road Traffic Safety Information Board as one of road traffic information. The whole processes of Recognition System of the Road Traffic Safety Information Board suggested in this study are as follows. We took the photographs of Road Traffic Safety Information Board with a digital camera in order to get an image and normalize bitmap image file with a size of $200{\times}200$ byte with Photo Shop 5.0. The existing True Color is made up the color data of sixteen million kinds. We changed it with 256 Color, because it has large capacity, and spend much time on calculating. We have practiced works of 30 times with erosion and dilation algorithm to remove unnecessary images. We drawing out original image with the Region Splitting Technique as a kind of segmentation. We made three kinds of grouping(Attention Information Board, Prohibit Information Board, and Introduction Information Board) by RYB( Red, Yellow, Blue) color segmentation. We minimized the image size of board, direction, and the influence of rounding. We also minimized the Influence according to position. and the brightness of light and darkness with Eigen Vector and Eigen Value. The data sampling this feature value appeared after building the learning Code Book Database. The suggested Recognition System of the Road Traffic Safety Information Board firstly distinguished three kinds of groups in the database of learning Code Book, and suggested in order to recognize after comparing and judging the board want to recognize within the same group with Nearest Neighborhood Decision Making.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1983.05a
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• pp.7.2-8
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• 1983

Chronic laryngotracheal stenosis is becoming increasingly prevalent. Many acceptable procedures such as repeated dilation, laryngotracheoplasty and end-to-end anastomosis had been done according to it's indication, but it have given less than favorable results. Since 1972 the experimental and clinical experiences of Jako and Strong, the carbon dioxide laser has offered a valuable tool to the otolaryngologist. Mihashi (1976) and Lyons (1980) reported use of laser to the management of laryngotracheal stenosis with successful results. From April 82' to March 83', using the carbon dioxide laser, the various obstructing lesions were excised microendoscopically which include four patients considered failures from conventional surgical technique and one patient laryngeal stenosis occured after hemilaryngectomy and neoglottis formation. We concluded as follows, 1) Laser surgery is a useful method to the management of laryngotracheal stenosis in maintaining adequate airway. 2) Formation of granulation after laser surgery was less than other conventional methods.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.1
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• pp.83-95
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• 1999

Wavelet transform has localization for time or frequency. It is useful to analyze a nonstationary signal. Basic function on wavelet transform is generated dilating and translating the original wavelet(mother wavelet). In this paper, time-frequency analysis method using linear combination wavelet transform is proposed. And it is applied to diagnostic monitoring system using the proposed linear combination wavelet transform. The stationary and nonstationary signal is used linear chirp signal, fan noise signal, a sinusoid signal from revolution body, electronic signal. Transform applied to signal analysis use fast Fourier transform (FFT), Daubechies, Haar and proposed linear combination method. The result of time-frequency analysis using linear combination wavelet transform is suited for portraying nonstationary time signal as well as stationary signal. Also the diagnostic monitoring system carry out the effective the signal analysis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.6
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• pp.130-137
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• 2018

Many constitutive models for concrete have been developed to predict the nonlinear behavior of concrete members considerably. The constitutive model for reinforcing bar that include the tension stiffening effect due to the bond characteristics between steel bars and concrete is being studied but the bilinear model is generally used. It was found that the buckling of the longitudinal reinforcing bars is controlled the nonlinear behavior of hybrid precast concrete panel, which is being developed for core wall. In this study, the constitutive models that can consider the embedding and buckling effects of reinforcing bar are investigated and a new model combing these constitutive models is proposed. In order to verify the proposed model, the analysis results are compared with experimental results of the concrete wall and hybrid precast concrete panel. The analysis of embedding-effect-only modeling predicted that the deformation increases continually without the decrease in the load carrying capacity. However, the analysis results of proposed model showed good agreement with some experimental results, thus verifying the proposed computational model.

• The KIPS Transactions:PartB
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• v.9B no.5
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• pp.681-688
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• 2002

This paper proposes a system detecting the area of traffic sign, which uses color rate as the information of colors, and corner point and distance rate as the information of morphology. In this system, a candidate area is extracted by performing dilation operation on the binary image made by the color rate of R, G, B components and by detecting corner point and center point through mask. The area of traffic sign with varied shapes is extracted by calculating the distance rate from center point, which is the information of morphology. The results of this experiment demonstrate that in this system which is invariable regardless of its size and location, it is possible to extract the exact area from varied traffic signs such as the shapes of triangle, circle, inverse triangle, and square as well as from the images at both day and night when brightness value is greatly different. Moreover, it demonstrates great accuracy and speed in processing.

• Journal of Chest Surgery
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• v.27 no.2
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• pp.140-147
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• 1994

Reconstruction of the pharynx and cervical esophagus presents a tremendous challenges to surgeons. Over the past 2 years[1990, Dec.-1993, Jun], the free jejunal graft has been performed in 17 cases in Korea Cancer Center Hospital.The indications of this procedures were almost malignant neoplasms involving neck and upper aero-digestive tract; Hypopharyngeal cancer[12 cases, including 2 recurrent cases], laryngeal cancer[2 cases], thyroid cancer[2 cases, including 1 recurrent case], cervical esophageal cancer[1 case]. There were fifteen men and two women, and the mean age was 59.6 years. The anastomosis site of jejunal artery were common carotid artery[16 cases] or external carotid artery[1 case] and that of jejunal vein were internal jegular [15 cases] or facial[1 case] and superior thyroid vein[1 case]. The length of jejunal graft was from 9 cm to 17 cm[mean 13 cm] and the mean ischemic time was 68 minutes. There was one hospital mortality which was irrelevant to procedures[variceal bleeding] and one graft failure[1/16]. Other postoperative complications were neck bleeding or hematoma[3 cases], abdominal wound infection or disruption[5 cases], anastomosis site leakage[1 case], pneumonia[2 cases], graft vein thrombosis[1 case], and food aspiration[1 case]. The function of conduit was excellent and ingestion of food was possible in nearly all cases. Postoperative adjuvant radiation therapy was also applicable without problem in 7 cases. During follow-up periods, the anastomosis site stenosis developed in four patients, and the tracheal stoma was narrowed in one case but easily overcome with dilation. In conclusion, we think that the free jejunal graft is one of the excellent reconstruction methods of upper digestive tract, especially after radical resection of malignant neoplasm in neck with a high success rate and low mortality and morbidity rate.