• Archives of Plastic Surgery
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• 제33권3호
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• pp.359-366
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• 2006

Acquired facial deformities following cancrum oris sequelae manifested variably according to the nature of tissue necrosis. In cases that tissue loss extends over a wide area of the face, or the tissue nature is different due to congenital facial cleft, it is difficult to reconstruct with a single operation. As cancrum oris has virtually disappeared from our country, clinical report of reconstruction is also rare. We report 5 cases of facial deformities following cancrum oris sequelae. Since 1988, five adult patients(4 female and 1 male) were treated by authors. These patients, with an age ranged from 47 to 58 years, all suffered from acquired facial cleft such as facial mutilation, asymmetry. The stages of operation were from 1 to maximum of 5 operations. All surgeries achieved satisfactory results after a long-term follow-up. But one surgery in the case of palatal mucosal flap for the coverage of reconstructed maxilla alveolar bone resulted tissue sloughness, followed by osteomyelitis. Those were debrided and discarded. In conclusion, all sites of deformities were positioned around one of the oral commissures. In their past medical history, they have been suffering from measles, typhoid fever and unknown febrile illness. We diagnosed the acquired facial deformity following cancrum oris sequelae. The reconstruction of acquired facial deformity following cancrum oris sequelae were difficult due to extensive multiple tissue defects. Therefore multiple staged operations were inevitable. The authors reconstructed 5 cases of simple and complex form of facial deformity with minimum staged operations. All patients were satisfied functionally and cosmetically.

• 한국재료학회지
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• 제13권7호
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• pp.465-472
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• 2003

Pd/Ge/Ti/Pt and Pd/Ge/Pd/Ti/Au ohmic contacts to n-type InGaAs were investigated for applications to AlGaAs/GaAs HBT emitter ohmic contacts. In the Pd/Ge/Ti/Pt ohmic contact minimum specific contact resistivity of $3.7${\times}$10^{-6}$ $\Omega$$\textrm{cm}^2$ was achieved by rapid thermal annealing at $^400{\circ}C$/10 sec. In the Pd/Ge/Ti/Au ohmic contact, minimum specific contact resistivity of $1.1${\times}$10^{-6}$ $\Omega$$\textrm{cm}^2$ was achieved by annealing at 40$0^{\circ}C$/10 sec but the ohmic performance was degraded with increasing annealing temperature due to the reaction between the ohmic contact materials and the InGaAs substrate. However, non-spiking planar interface and relatively good ohmic contact (high-$10^{-6}$ /$\Omega$$\textrm{cm}^2$) were maintained after annealing at $450^{\circ}C$/10 sec. Therefore, these thermally stable ohmic contact systems are promising candidates for compound semiconductor devices. RF performance of the AlGaAs/GaAs HBT was also examined by employing the Pd/Ge/Ti/Pt and Pd/Ge/Pd/Ti/Au systems as emitter ohmic contacts. Cutoff frequencies were 63.5 ㎓ and 65.0 ㎓, respectively, and maximum oscillation frequencies were 50.5 ㎓ and 51.3 ㎓, respectively, indicating very successful high frequency operations.

• 대한전자공학회논문지SD
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• 제44권7호통권361호
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• pp.81-89
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• 2007

비터비 복호기는 디지털 통신 시스템에서 순방향 오류 정정을 위해서 사용하는 핵심적인 부분으로 최우 추정 복호 방식의 알고리즘을 사용한다. 비터비 복호기는 복호기 상태의 개수만큼의 경로를 계산하고 역 추적하는 특성 때문에 저 전력화가 상당히 어렵다. 본 논문에서는 기존의 SPEC-T 알고리즘을 구현하는데 있어서 비교기의 동작을 최소화할 수 있는 효율적인 방법을 제안하고 ACS(Add-Compare-Select) 구조와 MPMS(Minimum Path Metric Search) 구조에 이를 적용하였다. 실험 결과, 제안한 ACS 구조와 MPMS 구조는 기존의 구조보다 전력 소모량이 임계 값 26에서 각각 최대 약 10.7%와 11.5% 감소하였고 SPEC-T 구조보다는 전력 소모량이 임계 값 26에서 각각 약 6%와 1.5% 더 감소하였다.

• Computers and Concrete
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• 제25권6호
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• pp.551-563
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• 2020

This paper investigates the artificial neural network (ANN) to predict the dimensionless parameters for the maximum contact pressures and contact areas of a contact problem. Firstly, the problem is formulated and solved theoretically by using Theory of Elasticity and Integral Transform Technique. Secondly, the contact problem has been extended based on the ANN. The multilayer perceptron (MLP) with three-layer was used to calculate the contact distances. External load, distance between the two quarter planes, layer heights and material properties were created by giving examples of different values were used at the training and test stages of ANN. Program code was rewritten in C++. Different types of network structures were used in the training process. The accuracy of the trained neural networks for the case was tested using 173 new data which were generated via theoretical solutions so as to determine the best network model. As a result, minimum deviation value (difference between theoretical and C++ ANN results) of was obtained for the network model. Theoretical results were compared with artificial neural network results and well agreements between them were achieved.

• Asian Pacific Journal of Cancer Prevention
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• 제16권14호
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• pp.5643-5645
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• 2015

Background: The aim was to see compliance to minimum data set information in carcinoma cervix histopathology reports from a team of 13 pathologists; and also to analyse the distribution of parameters like tumor size, grade, depth of cervical stromal invasion, lymph node yield and pTNM stage. Materials and Methods: All pathology reports of radical hysterectomy for carcinoma cervix operated in house within a three year duration (2010-2012), (n=204) were retrieved from medical records and analyzed for the above parameters. Results: In 2010- 59 cases, in 2011- 67 cases and in 2012- 78 cases of carcinoma cervix underwent operations in our hospital. The median age was 50.5 years and the maximum T diameter was 2.8 cms in the reports of three years. Squamous carcinoma was the commonest subtype amongst all the tumors. It was noted that 60.8% of cases had cervical stromal involvement more than half the thickness of the cervical stroma. Parametrial involvement was seen in 4.82% of cases. pTNM Staging was not mentioned in 65.06% of the cases. The mean bilateral pelvic lymph node yield count in our study was 16.6 inclusive of all the three years. Conclusions: Compliance with provision of a minimum dataset in our team of 13 pathologists was generally good. Lymph node yield in our hands is reasonable, but constant striving for greater numbers should be made. pTNM staging should be more meticulously documented. Use of proformas /checklists is recommended.

• Advances in pediatric surgery
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• 제4권1호
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• pp.55-60
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• 1998

Six children with solid and papillary epithelial neoplasm of the pancreas were studied retrospectively. There were 2 boys and 4 girls. The mean age at operation was 11 years(range; 8-13years). Three patients had incidental abdominal mass, in two patients the mass was non-tender, in one patient the mass was tender. The minimum size of tumor was $6.5{\times}6.0$ cm and the maximum was $10.5{\times}8.0$ cm. Five tumors were located in the head of the pancreas, and the other one in the tail. Local invasion or metastasis was not noticed. Tumors were removed completely by performing the following operations: 3 pylorous preserving pancreaticoduodenectomy, 2 Whipple's operation and 1 distal pancreatectomy. There was no mortality. The histologic findings were characteristic. There were no recurrences during a follow-up of 0.5 to 12 years (mean; 5.0 years).

• Environmental Engineering Research
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• 제17권4호
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• pp.191-196
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• 2012

Analysis of hydrological safety as well as the determination of many substance concentrations are necessary when bioreactor systems are introduced to landfill operations. Therefore, hydrological and substance balance model was developed since it can be applied to various bioreactor landfill operation systems. For the final evaluation of the model's effectiveness, four different methods of injections (leachate alone, leachate and organic waste water, leachate and reverse osmosis concentrate, and all the above three combination) was applied to 1st landfill site of Sudokwon landfill. As a result, the water content of the hypothetical cases for four different systematic bioreactors is projected to be increased up to 35.5% in next 10 years, and this indicated that there will be no problems in meeting the hydrological safety. Also, the final $Cl^-$ concentration after 10-yr time period was projected to be between from minimum 126 to maximum 3,238 mg/L, which could be still a decrease from the original value of 3,278 mg/L. According to the proposed model, whether the substance concentration becomes increased or decreased largely depends on the ratio of initial quantity of inner landfill leachate and the rate of injection.

• International Journal of Aerospace System Engineering
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• 제9권2호
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• pp.1-9
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• 2022

The NEA release mechanism is used to provide restraint and release functions with low shock for critical deployment operations on solar arrays after launch. The GK3 solar array consists of 2 wings and 6 hold down points per panel. The NEA SSD9103S1 is a part of the GK3 solar array hold-down and release mechanism. Each NEA unit is equipped with two Z-diodes which provide power to a NEA unit connected in series after actuation of the fuse wire. This paper presents the hot firing test results of a quadrature NEA SSD9103S1 configuration. One output powers a maximum of 4 NEA SSD9103S1 units simultaneously. The necessary actuation pulse duration has been determined to meet margin requirement for thermal energy of minimum 4. Actuation thermal energy difference is about 6.6% between each half of two fired serial NEAs. Thermal energy margin at worst case is minimum 5.9 in case of an actuation pulse duration of 500 ms. Two series Zener impedance depend on current applied has been characterized by an additional actuation after all fuse wires are open circuit. Total number of actuation commands to the GK3 NEA unit reduce drastically from 24 in case of single NEA configuration down to 8 in case of parallel and quadrature NEA configurations. It can be accommodated by the existing HP2U Pyro design without any impact.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2374-2376
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• 2004

In this paper, we describe a DSP-based test apparatus for Control Element Drive Mechanism (CEDM). Using this apparatus, we can catch the mechanical and electrical characteristics of CEDM and obtain the information about the improvement of CEDM and the design of CEDM power controller. The test apparatus for CEDM introduced in this paper can input firing angles directly into gate drive circuits of thyristors so that this method can be used to derive the maximum and minimum values of firing angles within available limits for a 3-phase half-wave rectifier. Angle inputs help us understand each coil's response characteristics. Since this apparatus generates a serial sequence for CEDM insertion and withdrawal operations, we may judge whether CEDM works correctly as expected or not in each phase of a step movement.

• 경영과학
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• 제13권3호
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• pp.163-172
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• 1996

According to flying hours, aircraft engines require regular overhaul for preventive maintenance. Because of hostile defense environment of Republic of Korea, the aircraft of republic of Korea Air Force(ROKAF) have been operated at the maximum level of availability and have similar overhaul schedule in several months. The concentration of overhaul schedule in a short period demands additional spare engines far exceeding the spare engines for corrective maintenance. If ROKAF decides to purchase extra engines for the preventive maintenance, the extra engines will be used only for the preventive maintenance and will be excess inventory for the most of aircraft life ccle. Also, the procurement of extra engines is significant investment for ROKAF. To help ROKAF schedule the preventive maintenance without significant spending, this study develops a dynamic programming model that is solvable using an integer programming algorithm. The model provides the number of engines that should be overhauled for a month for multiple periods under given constraints. ROKAF actually used this model to solve a T-59 engine overhaul problem and saved about three billion won at one time. ROKAF plans to use this model continuously for T-59 and other weapon systems. Thus, saving for long term will be significant to ROKAF. Finally, with minor modification, this model can be applied to deciding the minimum number of spare engines for preventive maintenance.