• 대한치과의사협회지
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• 제54권10호
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• pp.799-810
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• 2016

Orbital fractures have a significant portion in facial bone trauma. The important thing in treatment of orbital fractures is variable depending on the patient. Reconstruction of orbital wall demands an understanding of the anatomy and function of the orbit, including the orbital tissues, and the approacheds, materials, and methods available.

• Nonlinear Functional Analysis and Applications
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• 제28권4호
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• pp.929-942
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• 2023

In this paper, we discuss topological ergodic shadowing property and topological pseudo-orbital specification property of iterated function systems(IFS) on uniform spaces. We show that an IFS on a sequentially compact uniform space with topological ergodic shadowing property has topological shadowing property. We define the notion of topological pseudo-orbital specification property and investigate its relation to topological ergodic shadowing property. We find that a topologically mixing IFS on a compact and sequentially compact uniform space with topological shadowing property has topological pseudo-orbital specification property and thus has topological ergodic shadowing property.

• 충청수학회지
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• 제31권1호
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• pp.131-135
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• 2018

In this article, we deal with notion of idempotent in dynamical systems and prove that both closure function and orbital function are idempotent functions on the systems.

• 대한두개안면성형외과학회지
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• 제16권2호
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• pp.67-72
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• 2015

Background: A schwannoma is a benign, slow-growing peripheral nerve sheath tumor that originates from Schwann cells. Orbital schwannomas are rare, accounting for only 1% of all orbital neoplasms. In this study, we retrospectively review orbital schwannomas and characterize clinical, radiologic, and histologic features of this rare entity. Methods: A retrospective review was performed to identify patients with histologically confirmed orbital schwannoma, among a list of 437 patients who had visited our hospital with soft tissue masses within the orbit as the primary presentation between 2010 and 2014. Patient charts and medical records were reviewed for demographic information, relevant medical and family history, physical examination findings relating to ocular and extraocular sensorimotor function, operative details, postoperative complications, pathologic report, and recurrence. Results: Five patients (5/437, 1.1%) were identified as having histologically confirmed orbital schwannoma and underwent complete excision. Both computed tomography (CT) and magnetic resonance imaging (MRI) studies were not consistent in predicting histologic diagnosis. There were no complications, and none of the patients experienced significant scar formation. In two cases, patients exhibited a mild postoperative numbness of the forehead, but the patients demonstrated full recovery of sensation within 3 months after the operation. None of the five patients have experienced recurrence. Conclusion: Orbital schwannomas are relatively rare tumors. Preoperative diagnosis is difficult because of its variable presentation and location. Appropriate early assessment of orbital tumors by CT or MRI and prompt management is warranted to prevent the development of severe complications. Therefore, orbital schwannomas should be considered in the differential diagnosis of slow-growing orbital masses.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.501-504
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• 2005

In general, most incomplete communication link setup between satellite and ground station right after separation from launcher come from less accurate orbital vector ground station uses to track the satellite because only predicted orbital state vector is available during first few orbits. This paper describes the developed procedure for successful initial acquisition for KOMPSAT-2 using scanning functions ofK13 antenna system with predicted orbital information. Azimuth scan, raster scan, spiral scan functions were tested with KOMPSA Tl under intentionally degraded orbital information for antenna operation. Through tests, spiral scan function was decided to be best search scan among 3 scans. Developed procedure can assure the successful acquisition only if azimuth offset and time offset value are within +/-2deg and +/-30sec, respectively.

• Journal of Astronomy and Space Sciences
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• 제6권2호
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• pp.101-108
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• 1989

1983년 초 세 부분-COSMOS 1402-A, B, C-으로 분리되어 추락한 소련 위성 COSMOS 1402호의 낙하를 추정하기 위한 알골이즘을 개발하였다. 이 인공위성의 궤도에 영향을 미치는 섭동력으로는 지구의 비대칭 중력포텐셜과 지구의 대기 저항에 의한 섭동력이 고려되었고, 고도에 따른 지구의 대기 밀도를 구하기 위해 표준대기모델을 만들었다. COSMOS 1402호의 낙하시 NASA GSFC가 보내온 궤도요소 자료를 이용하여 COSMOS 1402-A와 C의 낙하시각과 낙하지점을 추정하고, 미국무성의 발표와 비교해 보았다. COSMOS 1402-C의 경우 모두 잘 일치함을 보이나 COSMOS 1402-A 의 경우 낙하시각이 1분, 낙하지점은 경위도 각각 2도씩의 오차를 보였다.

• Journal of Astronomy and Space Sciences
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• 제31권3호
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• pp.199-204
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• 2014

This paper intends to highlight the effect of the third-body in an inclined orbit on a spacecraft orbiting the primary mass. To achieve this goal, a new origin of coordinate is introduced in the primary and the X-axis toward the node of the spacecraft. The disturbing function is expanded up to the second order using Legendre polynomials. A double-averaged analytical model is exploited to produce the evolutions of mean orbital elements as smooth curves.

• 천문학논총
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• 제30권2호
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• pp.593-594
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• 2015

We present our analysis results for an updated orbital ephemeris for the dipping low mass X-ray binary 4U 1624-49, using the light curve collected by the All Sky Monitor (ASM) on board the Rossi X-ray Timing Explorer (RXTE) and the Monitor of All-Sky X-ray Image (MAXI). To make clear dip profiles, the light curve from the ASM and the MAXI were divided into ten 500d segments and four 400d segments for ASM and MAXI light curves, respectively, and folded with the linear ephemeris proposed by Smale et al. (2001). The phases of dip centers were determined by the method adopted from Hu et al. (2008). The phase drift was then fitted with a linear function. We obtained an updated orbital period of 0.869896(1) d and a phase zero epoch of JD 2450088.6618(57). No clear orbital period derivative is detected with a 2-sigma upper limit of $1.4{\times}10^{-6}(yr)^{-1}$ from a quadratic curve fitting of the dip phase evolution.

• 항공우주기술
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• 제7권2호
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• pp.187-195
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• 2008

고해상도의 인공위성 데이터로부터 지상좌표를 해석하는 센서모델링 기술은 위성영상자료의 활용 확대 및 신뢰성 확보에 가장 중요한 연구부분으로서 이에 대한 연구과 증가되고 있다. 본 연구는 이러한 요구조건을 기본을 하여, 고해상도 인공위성에서 기본적으로 탑재되어 있는 GPS, Star-tracker, Gyro 등의 센서로부터 측정된 위성의 위치, 속도, 자세 및 시간 정보를 이용하여 위성자료로부터 지상좌표를 해석하는 direct sensor model (DSM)과 위성의 궤도 정보를 얻을 수 없는 경우나 궤도에 대한 정보가 불확실하여 물리적 센서모델로는 지형보정을 수행할 수 없는 경우에 사용될 수 있는 rational function model (RFM)의 적용하여 지상좌표를 해석하는 방법에 대해 살펴보고자 한다.

• 대한화학회지
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• 제56권2호
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• pp.195-200
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• 2012

In this study we present a new approach for computing the partial atomic charge derived from the wavefunctions of molecules. This charge, which we call the "y_charge", was calculated by taking into account the energy level and orbital populations in each molecular orbital (MO). The charge calculations were performed in the software, which was developed by us, developed using the C# programming language. Partial atomic charges cannot be calculated directly from quantum mechanics. According to a partitioning function, the electron density of constituent molecular atoms depends on the electrostatic attraction field of the nucleus. Taking into account the Boltzmann population of each MO as a function of its energy and temperature we obtain a formula of partial charges.