Long-term Stability after Reduction of Mandible Fracture by Keyhole Plate: Evaluation at the Time of Plate Removal

Cheon, Kyeong-Jun,Cho, Seoung-Won,Jang, Won-Seok,Kim, Ju-Won,Yang, Byoung-Eun Korean Association of Maxillofacial Plastic and Re 2020 Maxillofacial Plastic Reconstructive Surgery Vol.42 No.-

Background: Various types of miniplates have been developed and used for the reduction of facial bone fractures. We introduced Yang's Keyhole (YK) plate, and reported on its short-term stability. The purpose of this study was to evaluate the long-term stability of the YK plate, as a follow-up study, by examining the patients who had used the YK plate among the patients with the reduction of mandible fractures and who visited for plate removal. Methods: We reviewed the medical records of 16 patients who underwent mandibular fracture fixation using a YK plate (group I) and 17 patients who underwent mandibular fracture fixation using a conventional plate (group II). Assessment was then made on malunion, occlusal stability, discomfort during the application, and clinical symptoms. Results: From January 2015 to December 2017, a total of 36 patients underwent mandibular fracture surgery using a YK plate. A total of 16 patients received plate removal. Among them, 15 were male and 1 female. The average age was 26 years. The applied surgical sites were the 12 on mandibular angle, 4 on mandibular symphysis, and 2 on subcondyle. The application period of YK plate was an average of 335 days. During the same period, 45 people underwent surgery on the conventional plate. A total of 17 patients received plate removal. Among them, 15 were male and 2 females. The average age was 36 years. The applied surgical sites were the 8 on mandibular angle, 4 on mandibular symphysis, and 2 on subcondyle. The application period of the conventional plate was an average of 349 days. No malocclusion occurred at the time of removal, and occlusion was stable. No patient complained of joint disease or discomfort. Conclusion: The YK plate system, in which the screw was first inserted and the plate was applied, for clinical convenience did not cause any particular problem and no significant difference from the conventional plate.

자판기 시스템 운영문제의 휴리스틱 해법 개발과 평가

박양병(Yang Byung Park),장원준(Won Jun Jang),박해수(Hae Soo Park) 한국산업경영시스템학회 2011 한국산업경영시스템학회지 Vol.34 No.4

The operation of vending machine system presents a decision-making problem which consists of determining the product allocation to vending-machine storage compartments, replenishment intervals of vending machines, and vehicle routes, all of which have critical effects on system profit. Especially, it becomes more difficult to determine the operation variables optimally when demand for a product that is out-of-stock spills over to another product or is lost. In this paper, we propose a heuristic for solving the operation problem of the vending machine system and evaluate it by comparing with Yang’s algorithm on various test problems with respect to system profit via a computer simulation. The results of computational experiments show a substantial profit increase of the proposed heuristic over Yang’s algorithm. Sensitivity analysis indicates that some input variables impact the profit increase significantly.

열형광 CaSO₄:Dy 소자의 최적 제조조건에 관한 연구

김장렬,남영미,장시영,김두영,양정선,박재우 제주대학교 산업기술연구소 2000 尖端技術硏究所論文集 Vol.11 No.1

An experimental investigation has been performed to determine optimal conditions for preparing the thermoluminescent CaSO4:Dy pellets which have been widely used as personal radiation dosimeter material. Our investigation has shown that an optimal weight concentration of the dopant Dy in the bulk CaSO4:Dy is 0.1 mol%, and an optimal temperature of adding Dy in the preparing process is 320 ℃. An optimal time and temperature for sintering the CaSO4:Dy crystal produced from the chemical process are found to be 2 hours and 800 ℃, respectively. The maximum thermoluminescent sensitivity was observed when the CaSO4:Dy crystal was pulverized to grain sizes of 63 - 200 ㎛ in diameter before being fabricated into pellets. The commercial Teflon was selected as an adhesive for the fabrication of the CaSO4:Dy pellets with an optimal mixing ratio of the Teflon and CaSO4:Dy being 70 to 30 in weight.

Ribbon형 Co1-x Crx (x=0.27, 0.29, 0.30, 0.32, 0.35) 합금의 자기특성

장현숙,김미양,이장로,이용호 숙명여자대학교 자연과학연구소 1994 자연과학논문집 Vol.- No.5

급냉법으로 리본형 결정질 Co1-x Crx (x=0.27, 0.29, 0.30, 0.32, 0.35)합금을 제조하여 Cr의 조성에 따른 자기적 특성을 조사하였다. 포화자화값은 벌크값보다 컸지만 박막의 경우보다는 작았다. Cr의 함량이 증가함에 따라 포화자화값은 감소하였다. 27 at.% Cr의 경우를 예외로 하면 Cr 함량 증가에 따라 결정립의 크기는 감소하였고, 항자력은 증가하였다. 리본형 Co1-x Crx 는 포화자화값의 온도 의존성이 비정질 시료인 경우와 유사한 경향을 나타내었으며 Cr의 함량이 증가할수록 Curie온도(Tr)는 감소하였다. Cr 함량의 증가에 따라 exchange interaction의 평균자승거리<r²>와 spin wave stiffness 상수D는 감소하는 경향을 나타내었다. 천이금속(Co)의 원자당평균 자기모멘트는 Cr의 증가에 따라 선형적으로 감소하였다. The magnetic cnaracteristics of crystalline Co1-x Crx (x=0.27, 0.29, 0.30, 0.32, 0.35) ribbons prepared by the rapid solidification were investigated. The saturation magnetization for ribbon was greater than that for bulk alloys containg the same amount of Cr. but smaller for the films. The grain size of ribbon became smaller and coercive force increased with increasing Cr contents except case of 27 at.% Cr. The saturation magnetization decreased with increasing Cr contensts. The temperature dependence of saturation magnetization for Co1-x Crx ribbon showed the similar behavior as the amorphous alloy and the Curie temperatures were decreased with the increase of Cr contents. The spin wave stiffness constant and the mean square range of exchange interaction, also were decreased. The average magnetic moment per transition metal atom was linearly decreased with increasing the contents of Cr.

大都市에 있어 行政文化의 特性에 관한 小考 : 서울市를 중심으로 Seoul City

梁暲勳 건국대학교 1984 政法論叢 Vol.19 No.1

Siloxane-Epoxy(s) Copolymer合成에 관한 硏究

梁在乾,韓貞璉,裵長淳 단국대학교 1981 論文集 Vol.15 No.-

Oligosiloxane prepared which has moleculae weight 900∼1,000 was prepared from O.M.C.S. and epoxy(S) resine was prepared from pisphenol(S) and epichlorohydrin. The siloxane-epoxy(S) copolymer was synthesized through the copolymerization of oligosiloxane and epoxy(S) resine under alkaline acetone solution at 50∼55℃ for 5 hours. Thermal properties of epoxy(S) resine and siloxane-epoxy(S) copolymer was measured by thermogravimetric analysis, copolymer with 8.2% silicon content had the higher degradation temperature 300℃ than epoxy(S) reine which degradation at 250℃.

유연한 수리계획 작성을 위한 모형관리자의 설계 및 구현

양영철,장양자,김기동,박진우 한국경영과학회 2001 한국경영과학회 학술대회논문집 Vol.- No.1(2)

Recently, in the competitive environments, every company recognizes the importance of planning models. However, there are so many problems in correctly applying mathematical model to the real world. Because mathematical modeling packages, especially, charge planning managers with understanding the models and responsibility for generating plans, fast and accurate model cannot be generated with ease. In this paper, we design the system that helps planning managers flexibly create and modify mathematical models and manage model versions. Also, we implement this model management system with model base concept.

Li 화합물을 첨가한 CaSO₄:Dy 열중성자 측정용 TLD 소자 개발

양정선,김두영,박재우,김장렬,장시영 제주대학교 방사능이용연구소 2003 연구보고 Vol.17 No.-

Personal neutron dosimetry is quite a difficult area because a neutron is always accompanied with gamma radiation, which is required of a capability for mixed field dosimetry. CaSO₄:Dy phosphor is known to have a very high sensitivity to gamma, but the neutron capture cross section of the constituents of CaSO₄:Dy are so small that the interactions between the thermal neutron and the phosphor are rare. One method to improve the neutron interaction is by introducing an impurity ion with a large thermal neutron captures cross section into the phosphor to act as a neutron target centre such as 6Li. In neutron-gamma mixed radiation fields, if two detectors for the 6Li-7Li compounds embedded CaSO₄:Dy TL pellets are used, a 6Li-compound embedded pellet can detect the neutron and gamma radiation together, and the other pellet can only detect the gamma radiation. Recently Korea Atomic Energy Research Institute (KEARI) has developed a new type of CaSO₄:Dy TL materials embedded with phosphorous (KCT-300) to detect beta and gamma radiation with a very high sensitivity[1]. This paper presents the development of CaSO₄:Dy TL pellets embedded with 6Li compound for a thermal neutron measurement, and the detection method of the neutron and gamma dose in mixed fields with CaSO₄:Dy TL pellets embedded with a 6Li compound(KCT-306) and CaSO₄:Dy TL pellets embedded with a 7Li compound(KCT-307) is introduced. The net neutron sensitivity of CaSO₄:Dy TL pellets embedded with 6Li compound developed in this study is higher than that of the TLD-600 (Harshaw Co.) dosimeter which is available in the open market.

GPS 항법 알고리즘의 성능 분석

양장군,김병완,심덕선 중앙대학교정보통신연구소 2000 정보통신연구소논문집 Vol.2 No.1

본 논문에서는 GPS 항법 시스템에 Least square Method. Direct Solution Method, Improved Direct Solution Method, Kalman Filter 등 여러 항법 알고리즘을 사용하여 각각의 방법에 대하여 SA(Selective Availability) 오차(2000년 5월 1일부터 제거됨) 및 여러 오차요인의 영향에 따른 알고리즘들의 추정성능을 모의실험을 한 후 그 성능을 비교 분석하였다. 알고리즘별로 성능에는 큰 차이가 없었으며 SA가 없을 때 서울지역에서는 수평면오차(2drms)가 8m 이내, 위도 경도가 0˚인 지역에서는 2m 이내로 들어옴을 알 수 있었다. In this paper, positioning performance according to the effect of SA and Tropospheric error, Ionospheric error is tested comparing Least Square Method. Direct Solution Method, Improved Direct Solution Method and Kalman Filter Method that are used navigation algorithms for GPS receiver. Considering only Tropospheric error and Ionospheric error, simulation shows that horizontal estimation error is less than 8m(2drms) at Seoul area and less than 2m(2drms) at the point where latitude and longitude are all zero.

복강 내 체액의 Cytokine 농도를 이용한 난소암과 양성난소질환의 감별진단

양선문,송경은,서장수,조영래 대한임상병리학회 2000 대한임상병리학회지 Vol.20 No.6