• Archives of Plastic Surgery
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• v.36 no.4
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• pp.365-371
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• 2009

Purpose: Good color match holds a key position in facial reconstruction for good aesthetic result. To correct the wide facial soft tissue defect were usually used the tissue expanded cheek flap, deltopectoral flap or radial forearm free flap. This study is aimed to analyse the color difference after flap surgery by using chromameter. Method: From August 1995 to December 2006, 30 patients underwent flap operations were chosen randomly and evaluated color differences between flap site and adjacent skin. Reconstructive procedures included tissue expanded cheek flap(n = 10), deltopectoral flap(n = 10), and radial forearm free flap(n = 10). The measured sites were flap center within a radius of 1 ㎝ and four points of adjacent skin along the flap margin. The color was quantified in a three dimensional coordinate system $L^*$ (brightness), $a^*$ (redness), $b^*$ (yellowness). Results: There was no significant color difference between the pedicled flaps(tissue expanded cheek flap and deltopectoral flap) and adjacent skin area. On the other hand, color values of the radial forearm free flap were statistically different from those of adjacent skin area. Total color difference(${\Delta}E$) of tissue expanded cheek flap and deltopectoral flap were $7.45{\pm}5.78$ versus $9.41{\pm}7.09$, and that of radial forearm free flap was $11.74{\pm}3.85$. They suggest that pedicled flaps have a potential of better color match than radial forearm free flap. Conclusion: Thus, better esthetic result and satisfaction is more likely to be expected in pedicled flaps as long as it could be applied comparing radial forearm free flap.

• Archives of Plastic Surgery
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• v.44 no.1
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• pp.59-64
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• 2017

Background Silicone implants are frequently used in augmentation rhinoplasty in Asians. A common complication of silicone augmentation rhinoplasty is capsular contracture. This is similar to the capsular contracture after augmentation mammoplasty, but a classification for secondary contracture after augmentation rhinoplasty with silicone implants has not yet been established, and treatment algorithms by grade or severity have yet to be developed. Methods Photographs of 695 patients who underwent augmentation rhinoplasty with a silicone implant from May 2001 to May 2015 were analyzed. The mean observation period was 11.4 months. Of the patients, 81 were male and 614 were female, with a mean age of 35.9 years. Grades were assigned according to postoperative appearance. Grade I was a natural appearance, as if an implant had not been inserted. Grade II was an unnatural lateral margin of the implant. Clearly identifiable implant deviation was classified as grade III, and short nose deformation was grade IV. Results Grade I outcomes were found in 498 patients (71.7%), grade II outcomes in 101 (14.5%), grade III outcomes in 75 (10.8%), and grade IV outcomes in 21 patients (3.0%). Revision surgery was indicated for the 13.8% of all patients who had grade III or IV outcomes. Conclusions It is important to clinically classify the deformations due to secondary contracture after surgery and to establish treatment algorithms to improve scientific communication among rhinoplasty surgeons. In this study, we suggest guidelines for the clinical classification of secondary capsular contracture after augmentation rhinoplasty, and also propose a treatment algorithm.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.491-496
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• 2003

In Korea, the dose limits to the public were reduced according to ICRP-60 recommendations. The secondary quantities, Effluent Concentration Limits (ECLs) were derived and enacted to Korean Atomic Laws based on ICRP-60 recommendations. The Korea atomic laws require assurance that radioactive materials within gaseous effluents do not exceed dose limits and ECLs. This simply means that any effluent that would possibly contain radioactivity must be monitored. There are various methods to monitor the radioactivity of effluent monitor to satisfy the dose limits and the ECLs for gaseous effluents. The many factors (safety margin) should be considered in determining of the setpoint of effluent monitor, following these limits. In this study, we studied the determination method of alarm setpoint for gaseous effluent Radiation Monitoring Systems using dose factors considered the main pathway of radionuclides to compare the preceding determination method of alarm setpoint for gaseous effluent RMSs using dose assessment program considered all the practicable pathways of radionuclides.

• Journal of the Institute of Convergence Signal Processing
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• v.6 no.4
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• pp.206-211
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• 2005

We describe the design for a correlator and an access code generator in bluetooth system. These are used for a connection setting, a packet decision and a clock synchronization between Bluetooth units. The correlator consists of two blocks; carry save adder based on Wallace tree and threshold-value decision block. It determines on an useful packet and clock-synchronization for input signal of 1.0Mbps through the sliding-window correlating. The access-code generator also consists of two blocks; BCH(Bose-Chadhuri-Hocquenghem) cyclic encoder and control block. It generates the access-codes according to four steps' generation process based on Bluetooth standard. In order to solve synchronization problem, we make use of any memory as a pseudo random sequence. The proposed correlator and access-code generator were coded with VHDL. An FPGA Implementation of these modules and the simulation results are proved by Xilinx chip. The critical delay and correlative margin based on synthesis show the 4.689ns and the allowable correlation-error up to 7-bit.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.3
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• pp.275-283
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• 2006

Statement of problem. There have been many studies about marginal discrepancy of single restorations made by various systems and materials. However most of the statistical inferences are not definite because of sample size, measurement number, measuring instruments, etc, and there have been few studies about the marginal fit of the Digident CAD/ CAM zirconia ceramic crowns. Purpose. The purpose of this study was to compare the marginal fit of the anterior single restorations made by using the Digident CAD / CAM zirconia ceramic crowns with metal-ceramic restorations and to obtain more accurate information by using a large enough sample size and by making sufficient measurements per specimen. Material and Methods. The crowns were made from one extracted maxillary central incisor pre-pared with a 1mm shoulder margin and $6^{\circ}$ taper walls by milling machine. The in vitro marginal discrepancies of the digident CAD / CAM zirconia ceramic crowns and control groups(metal ceramic crowns) were evaluated and compared. Twenty crowns per each system were fabricated. Measurements of a crown were recorded at 50 points that were randomly selected for marginal gap evaluation. Parametric statistical analysis was performed for the results. Conclusion. Within the limitations of this in vitro study, the following conclusions were drawn: 1. Mean gap dimensions and standard deviations at the marginal opening for maxillary incisal crowns were $88{\pm}10{\mu}m$ for the control (metal-ceramic crowns), $92{\pm}4{\mu}m$ for Digident CAD / CAM zirconia ceramic crowns. 2. Marginal gap between Digident CAD / CAM zirconia ceramic crowns and metal ceramic crowns did not show significant difference (P>.05). 3. The Digident CAD/ CAM zirconia ceramic crowns and metal ceramic crowns showed clinically acceptable marginal discrepancy.

• Proceedings of the Safety Management and Science Conference
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• 2002.11a
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• pp.305-319
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• 2002

International capital movement has made progress at global liberalization of finance and foreign exchange, international monetary norm changing into floating exchange rate system, easiness of collection of information and trade at improvement of information communication technology from early of 1970's. Results of empirical test for relation between foreign exchange rate or various determination factors of foreign exchange rate and interest rate are followed by next sentences. First, according to relation between foreign exchange rate and interest rate, correlation for each of variables after OECD entrance is increased. But, long-term ＆short-term interest rate is affected by Hanbo ＆ Kia's bankruptcy, continuous large scale coporates bankruptcy and crisis of foreign exchange. Therefore, financial instability is occured. If portfolio investment fund has been inflow as it is mollified by continuous shortage of foreign exchange and fall of country's credit rating, it is expected to have positive effect for long-term & short-term interest rate from appreciation of won against dollar. Second, results from relation between determination factor of foreign exchange rate and interest rate are followed by next sentences. If surplus of current account and goods account is continued, yield of corporate bond is to be stable. But, margin of surplus is expected to diminish after second quarter 98, and difference between external and domestic interest (after adjusting foreign exchange rate) is to be diminished. And if net inflows of foreign investor's fund (stock and bond) is diminished, it is to have negative effect for yield of corporate bond. According to foreign investor's investment movement of previous years, hedge md were stayed at least during two years in Mexico. It means that sudden capital outflow is not to be happened at Korea. But if external factors from depreciation of yen and China's renminbi are instable, interest rate is expected to increase from capital's outflows. Third, if it is to decrease instability of foreign exchange rate from increase in surplus of future current account, credit rating's upwardness, stability of yen and renminbi, foreign exchange rate is expected to be stable. It is expected to have continuous stability from short-term interest rate to long-term interest rate in this empirical test.

• Korean Journal of Optics and Photonics
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• v.31 no.4
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• pp.169-175
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• 2020

We design a polarization-independent dielectric multilayer thin-film diffraction grating for a spectral-beam-combining (SBC) system with a simple grating structure and low aspect ratio. To maintain the high quality of the SBC beam, we propose a multilayer mirror structure in which the wavefront distortion due to stress accumulation is minimized. Moreover, to prevent light absorption from contamination, an optimized design to minimize the grating thickness was performed. The optimally designed diffraction grating has 99.36% diffraction efficiency for -1st-order polarization-independent light, for incidence at the Littrow angle and 1055-nm wavelength. It is confirmed that the designed diffraction grating has sufficient process margin to secure a polarization-independent diffraction efficiency of 96% or greater.

• The Journal of Society for e-Business Studies
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• v.4 no.1
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• pp.87-101
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• 1999

To operate the automatic devices of manufacturing process more effectively and to solve the needs of the resource sharing, network technology is applied to the control devices located in common manufacturing zone and operated by connecting them. In this paper, functional standard of the network layers are set as physical and data link layer of IEEE 802.2, 802.4, and VMD application layer and ISO-CIM reference model. Then, they are divided as minimized architecture, designed as group objects which perform group management and service objects which organizes and operates the group. For the stability in this network, this paper measures the variation of data packet length and node number and analyzes the variated value of the waiting time for the network operation. For the method of the analysis, non-exhausted service method are selected, and the arrival rates of the each data packet to the nodes that are assumed to form a Poission distribution. Then, queue model is set as M/G/1, and the analysis equation for waiting time is found. For the evalution of the performance, the length of the data packet varies from 10 bytes to 100 bytes in the operation of the group management network, the variation of the wating time is less than 10 msec. Since the waiting time in this case is less than 10 msec, response time is fast enough. Furthermore, to evaluate the real time processing of the group management network, it shows if the number of nodes is less than 40, and the average arrival time is less than 40 packet/sec, it can perform stable operation even taking the overhead such as software delay time, indicated packet service, and transmissin safety margin.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.1A
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• pp.10-27
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• 2005

In this paper, we propose a high level design architecture of WCDMA(UMTS) base station modem and synchronization algorithms applied to the proposed architecture. Also analysis of each synchronization algorithm and performance evaluation of fixed point designed modem are shown. Since the target system is base station modem, each synchronization algorithm is designed for its stable operation. To minimize implementation complexity, optimum fixed point design for best operation of synchronization algorithms is performed. We performed symbol level link simulation with fixed point designed modem simulator for data rate of 12.2kbps, 64kbps, 144kbps, and 384kbps. We compared performance results to the minimum requirements specified in 3GPP TS 25.104(Release 5). Extensive computer simulation shows that the proposed modem architecture has stable operation and outperform the minimum requirement by 2 dB. The proposed modem architecture has been applied in the implementation of WCDMA reverse link receiver modem chip successfully.

• Journal of Yeungnam Medical Science
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• v.2 no.1
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• pp.259-264
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• 1985

Neuroblastoma is the most common extracranial solid tumor of childhood which presents various clinical symptoms depending on the primary and metastatic sites. However, it has been rarely reported that sudden onset of blindness was the chief complaint of neuroblastoma. A four years old boy was admitted to the Yeungnam University Hospital with the chief complaint of a sudden onset of blindness due to a distant metastasis of abdominal neuroblastoma to the sphenoid sinus. On admission, both side pupils were dilated without light reflex, fundoscopy showed pale optic disk, electroretinogram was subnormal and visual evoked potential showed no response. The liver was palpable in $3{\frac{1}{2}}$ finger breadth from the right costal margin and adult fist sized mass was palpable in the right flank. Skull X-ray showed destructed sphenoid bone and clinoid process and brain CT scan showed tumor mass in the sphenoid sinus and left orbit. Ultrasonogram and CT scan of the abdomen showed large tumor masses around the right kidney and para-aortic and retropancreatic lymph node. IVP showed displaced right calyceal system with preserved contour. Left supraclavicular lymph node which appeared after admission was biopsied and it showed poorly differentiated neuroblasts. He was treated according to the multiagent chemotherapy schedule for stage IV neuroblastoma patient of children's cancer study group. Abdominal tumor masses and sphenoid sinus mass were markedly reduced after 2 courses of the combination chemotherapy of cyclophosphamide, vincristine, DTIC, adriamycin and VM-26. Eventhough the blindness was not improved, the patient has been in good clinical condition.