• Imaging Science in Dentistry
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• v.32 no.4
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• pp.201-206
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• 2002

Purpose : To evaluate the radiographic change of operation sites after orthognathic surgery using the digital image processing and fractal analysis. Materials and Methods : A series of panoramic radiographs of thirty-five randomly selected patients who had undergone mandibular orthognathic surgery (bilateral sagittal split ramus osteotomy) without clinical complication for osseous healing, were taken. The panoramic radiographs of each selected patient were taken at pre-operation (stage 0), 1 or 2 days after operation (stage 1), 1 month after operation (stage 2), 6 months after operation (stage 3), and 12 months after operation (stage 4). The radiographs were digitized at 600 dpi, 8 bit, and 256 gray levels. The region of interest, centered on the bony gap area of the operation site, was selected and the fractal dimension was calculated by using the tile-counting method. The mean values and standard deviations of fractal dimension for each stage were calculated and the differences among stage 0, 1, 2, 3, and 4 were evaluated through repeated measures of the ANOVA and paired t-test. Results : The mean values and standard deviations of the fractal dimensions obtained from stage 0, 1, 2, 3, and 4 were 1.658±0.048, 1.580±0.050, 1.607±0.046, 1.624±0.049, and 1.641 ±0.061, respectively. The fractal dimensions from stage 1 to stage 4 were shown to have a tendency to increase (p < 0.05). Conclusion: The tendency of the fractal dimesion to increase relative to healing time may be a useful means of evaluating post-operative bony healing of the osteotomy site.

• Korean Institute of Interior Design Journal
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• v.18 no.5
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• pp.89-100
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• 2009

Stage lighting system is very important in theater. Because basic of performing art. Recently, The stage lighting system is very close with a performing arts. The performance arts is to have an easy communication between actors and audience. All activities related to performance art take place between the stage light and auditorium. Therefore, when constructing theater the best conditions of the stage light system should be considered for the smooth progress of play. It will be method of solution that basically facility in the performance art hall. The results of this study can be used for suggesting an operation and system improvement for stage lighting system in performance art hall. Recently, changes in the progress of plays have required the perfect stage light system. As a result, performance art hall are the most advanced stage lighting system technology of changed. The following procedures were taken for this research-the literature on the development of stage lighting system and equipment, structure, and the dimmer and computer console system has been reviewed theoretically Most of all, Cheonan City Hall Bongseo Hall and CMB EXPO art hall is important a sample of lighting system. The result of this study presents operation and system improvement stage lighting system in theater, below to operation and system improvement at stage lighting system local self-government corporation performance art hall are inconsistent stage.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.157-158
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• 2023

Doors that are opened and closed when entering or exiting a general building are connected to the door frame and open and close. They are equipped with door locking devices of various structures, and are either locked to the door frame for the closing operation or released from the door frame for the opening and closing operation. Here, a single-stage door binding device having a door latch that is independently disposed at the center of one axis of the door is commonly used. On the other hand, if the size of the door is over a certain size or if the door is medium to large, the opening and closing operation may not be performed smoothly with only a single stage binder, or the closing state may not be achieved stably during the closing operation. In particular, in the case of the single-stage binding device provided in medium to large fire doors, the door is fixed to the door frame unstable, causing fatal errors in the fire prevention function of the fire door. Accordingly, in order to fundamentally solve these problems, we researched and developed a three-stage door binding machine that combines a top and bottom fastening structure with a single-stage fastening structure. This 3-stage door binder not only has the fire resistance performance of a fire door, but also has a T-shaped terminal in its fastening method, so if you eliminate the upper and lower fastening, it is a 1-stage binder like a regular product, but if you remove the door latch of the 1st-stage binder, it functions as an upper and lower 2-stage binder and forms a single mold. We researched and developed a three-stage door binder that can manufacture and produce three products at the same time, satisfying both product performance and price.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.4
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• pp.285-293
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• 2021

An optimal operation method based on weighted efficiency for a two-stage boost converter is proposed in this study. Detailed loss analysis of the converter is performed to derive the optimal operation method according to the load and input voltage fluctuations, and the optimal DC-bus voltage is derived by applying the weighted efficiency method. The proposed method can satisfy optimal efficiency in the main operation region without a complicated control method. Using 1kW typical two-stage boost converter and is verified three types of weighted efficiency formulas and loss analysis are utilized to derive high-efficiency optimal DC-bus voltage from each load range.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.43
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• pp.249-263
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• 1997

This paper addresses the parts route selection and economic design in flexible manufactuirng system (FMS). Parts are processed through several stage workstations according to operation sequences. The machine of each workstation can do multiple operation functions. And the operation stage of a part can be processed in several workstations, which are non-identical in functional performance. The objective of this paper is to determine the processing routes of parts, number of machine at each workstation, number of vehicle and makespan time. Two models are suggested. One is assumed that the operation stage of parts can be processed at the only one among several available workstations. Other is assumed that the operation stage of parts is allowed to be processed at several workstations. Parts are transported by automated guided vehicles (AGVs). The decision criteria is to minimize the sum of processing cost, travel cost, setup cost and overhead cost. The formulation of models is represented. A solution algorithm is suggested, and a numerical example is shown.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.9
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• pp.76-83
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• 1993

A morphological filtering algorithm using directional information is presented. Directional filtering technique is effective in reducing noises and preserving edges. The proposed directional filtering is composed of two stage filtering processes. The opening and closing operations in the lst stage are performed for the pixels is aligned to the vertical, horizontal, and two diagonal directions, respectively. The opening operation supresses the positive impulse noises, while the closing operation the negative ones. Then, each directional result and their average value are filtered by the opening or closing operations in the 2nd stage. The averaging operation diminishes the effects of Gaussian noises in the homogeneous regions. Thus, the morphological operation in the 1 st stageremoves the impulse noises and in 2nd stage reduces. Gaussian ones. The experimental results show that the proposed filtering is superior to the existing nonlinear filtering in the aspects of the subjective quality. Also, the morphological filtering method reduces the computational loads.

• Journal of Chest Surgery
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• v.25 no.4
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• pp.398-405
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• 1992

Twenty nine adult patients underwent surgical esohpagectomy and one, bypass procedure for documented carcinoma of esophagus and cadiac portion of stomach at Chonnam National University Hospital from Jan 1986 to April 1991. There were several kinds of esophagectomies including through transhiatal, left thoracotomy only, laparotomy and thoracotomy, and laparotomy and right thoracotomy and cervical incision. Twenty five and squamous cell carcinoma and 5, adenocarcinoma. The tumor locations were the upper third in 3, middle third in 12, lower third in 10 and cardiac portion of stomach in 5. After operation, 8[27%] patients were classified in Stage IIa, 6[20%] patients in Stage IIb, 15 patients[50%] in Stage III and one patient in Stage IV. Major postoperative complications included anastomotic narrowing in 3, limited suture line leak in 2, wound infection in 2, hoarseness in 2, pseudomembraneous enterocolitis in 1 and herpes zoster in 1. There was no death within 30 days of operation. Ten months survival was 100% for patients with Stage lIa, 67% for patients with Stage IIb, 50% for patients with Stage III. Furthermore, 20 months survival was 75% in IIIa, 33% in IIb, and 40% in III. But there were no significant differences in survivals among the stage. The actuarial survival is 58% at one year and 41% at two years, The periods of average survival is 589 days after operation.

• Advances in pediatric surgery
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• v.13 no.1
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• pp.61-65
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• 2007

Conventional treatment of Hirschsprung's disease consists of initial colostomy followed by pull-through operation. But, the treatment of Hirschsprung's disease has been changed along with the development of new surgical technique. Since 1995, endo-GIA has been available at our hospital and one stage Duhamel operation has been performed for neonatal Hirschsprung's disease. Between May 1995 and April 2006, 26 neonates have been treated with one stage pull-through operation by one pediatric surgeon at HanYang University Hospital. The sex ratio was 4.2:1 with male predominance. Clinical findings included abdominal distension (96.2 %), vomiting (50.0 %), delayed passage of meconium (46.2 %), constipation (23.1 %), and enterocolitis (15.4 %). Twenty two cases (84.6 %) were short-segment and 4 cases (15.4 %) were long-segment disease, of which 2 cases were total colon aganglionosis. One of the two patients with total colonic aganglionosis had double transition zones - distal ileum and hepatic flexure of the colon. The average age at operation was $14.56{\pm}8.77$ days and the average weight at operation was $3.26{\pm}0.66kg$. Primary Duhamel operations were performed in 25 patients and Soave-Boley operations was performed in one patient. The endo-GIA 35 (Ethicon, USA) was used from 1995 until 1997, and after that endo-GIA 60 (USSC, USA) was used. The average Duhamel operation time was $88.57{\pm}22.80$ minutes. Wound abscess (n = 2) and septum formation (n =1) occurred after Duhamel operation. Bowel function was normalized in 59 % within 3 months and in 95% within 1 year after operation. There was no mortality after one stage pull-through operation in neonate.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.659-662
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• 1999

As utility pollution take a growing interest, ac/dc converter optimizing utility condition has been vigorously studied in decades. In this paper three phase DCM converter is analyzed and equations for average input currents are presented. Also relationships of voltage gain & duty according to angular velocity are presented and variable frequency controller is implemented using reset integrator which is designed in detail. In result power factor and THD characteristics of 3-stage and 4-stage operation ae compared respectively.

• Journal of Chest Surgery
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• v.33 no.1
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• pp.68-72
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• 2000

Background: The resection of recurrent non-small cell lung cancer can be performed very rarely. There has been many arguments for longterm result and therapeutic role in surgical management of recurrent non-small cell lung cancer(NSCLC). We analyze our result of surgical re-resection of recurrent NSCLC for 10 years retrospectively. Material and Method: In the period from 1987 to 1997, 702 patients who had been confirmed for NSCLC had undergone complete resection in Seoul National University Hospital. As December 1997, 22 of these patients have been operated on the diagnosis of recurrent lung cancer. In these patients one has revealed for benign nodule at postoperative pathologic pathologic was unresectable. and two had revealed other cell type on postoperative pathologic examination. Analysis about postoperative survival rate and the factors that influence postoperative survival rate - sex, age, pathologic stage, cell type, operation adjuvant therapy after first and second operation location of recurrence disease free survival-was 59.1$\pm$10.9 year. There were 14 men and 3 women. Four patients was received radiation therpy after first opration and two patients was received postoperative chemotherapy. At first operation 2 patients was stage Ia, 8 was stage Ib, 1 was stage IIa 6 was stage IIb. Eleven patients had squamous. cell carcinoma at postoperatrive pathologic examination five had adenocarcinoma and one had bronchioalveolar carcinoma. In second operation 8 patients were received limited resection. 9 were received lobectomy or pneumonectomy. One-year survival rate was 82.4% and five-year survival rate was 58.2% Non-adjuvant therapy group after initial operation was more survived than adjuvant therapy group statistically. Conclusion: operation was more survived than adjuvant therapy group statistically. Conclusion : Operation was feasible treatment modality for re-resectable non-small cell lung cancer. But we cannot rule out possibility of double primary lung cancer for them. Postoperative prognostic factor was adjuvant therapy or nor after first oepration but further study of large scale is needed for stastically more valuable result.