• Korean Journal of Geomatics
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• 제2권1호
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• pp.47-55
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• 2002

Remote sensing is the science and art of obtaining information about an object, area or phenomenon through the analysis of data acquired by a device that is not in contact with the object, area, or phenomenon under investigation./sup 1)/ EOC (Electro -Optical Camera) sensor loaded on the KOMPSAT-1 (Korea Multi- Purpose Satellite-1) performs the earth remote sensing operation. EOC can get high-resolution images of ground distance 6.6m during photographing; it is possible to get a tilt image by tilting satellite body up to 45 degrees at maximum. Accordingly, the device developed in this study enables to obtain images by photographing one pair of tilt image for the same point from two different planes. KOMPSAT-1 aims to obtain a Korean map with a scale of 1:25,000 with high resolution. The KOMPSAT-1 developed automated feature extraction system based on stereo satellite image. It overcomes the limitations of sensor and difficulties associated with preprocessing quite effectively. In case of using 6, 7 and 9 ground control points, which are evenly spread in image, with 95% of reliability for horizontal and vertical position, 3-dimensional positioning was available with accuracy of 6.0752m and 9.8274m. Therefore, less than l0m of design accuracy in KOMPSAT-1 was achieved. Also the ground position error of ortho-image, with reliability of 95%, is 17.568m. And elevation error showing 36.82m was enhanced. The reason why elevation accuracy was not good compared with the positioning accuracy used stereo image was analyzed as a problem of image matching system. Ortho-image system is advantageous if accurate altitude and production of digital elevation model are desired. The Korean map drawn on a scale of 1: 25,000 by using the new technique of KOMPSAT-1 EOC image adopted in the present study produces accurate result compared to existing mapping techniques involving high costs with less efficiency.

• 대한치과교정학회지
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• 제49권6호
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• pp.393-403
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• 2019

Objective: Sliding mechanics using orthodontic miniscrews is widely used to stabilize the anchorage during extraction space closure. However, previous studies have reported that both posterior segment displacement and anterior segment displacement are possible, depending on the mechanical properties of the archwire. The present study aimed to investigate the effect of archwire stiffness and friction change on the displacement pattern of the maxillary posterior segment during anterior segment retraction with orthodontic miniscrews in sliding mechanics. Methods: A three-dimensional finite element model was constructed. The retraction point was set at the archwire level between the lateral incisor and canine, and the orthodontic miniscrew was located at a height of 8 mm from the archwire between the second premolar and first molar. Archwire stiffness was simulated with rectangular stainless steel wires and a rigid body was used as a control. Various friction levels were set for the surface contact model. Displacement patterns for the posterior and anterior segments were compared between the conditions. Results: Both the anterior and posterior segments exhibited backward rotation, regardless of archwire stiffness or friction. Among the conditions tested in this study, the least undesirable rotation was found with low archwire stiffness and low friction. Conclusions: Posterior segment displacement may be unavoidable but reducing the stiffness and friction of the main archwire may minimize unwanted rotations during extraction space closure.

• Journal of Interdisciplinary Genomics
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• 제1권2호
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• pp.19-22
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• 2019

CATCH 22 syndrome is rare genetic disease that has various manifestations. Cervical vertebral anomaly, such as Klippel-Feil anomaly, is frequently observed in the patients with CATCH22 syndrome. We present the case of an 11-year-old female patient with CATCH22 syndrome and Klippel-Feil anomaly who had been treated torticollis using the customized soft neck collar. During the patient's first visit to our clinic, she presented with low ear set, skull deformity, intellectual disability, and tilting of the head to the left by approximately 25 degrees. Imaging studies revealed multisegmental fusion and C3 hemivertebrae of the cervical spine and left thoracic scoliosis at T4 with 50 degrees of Cobb's angle. We instructed passive stretching and applied the customized soft neck collar we invented. The ipsilateral aspect of the neck collar is designed to provide vertical support between the clavicle and mandibular angle and is adjustable in height. The Velcro was attached to the neck collar at the point of contact with the ipsilesional mandibular angle, which provides negative sensory feedback, inducing her to tilt neck to the contralesional side. We applied the neck collar for 2 hours a day. After 1 year of treatment, her neck inclination angle improved from 25 to 10 degrees. Providing negative sensory feedback using the customized soft neck collar can be one of the treatment options of postural management in patients with torticollis in cases of CATCH 22 syndrome combined with Klippel-Feil anomaly.

• 대한조선학회논문집
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• 제42권5호
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• pp.479-486
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• 2005

The final goal of shift alignment design is that the bearing reaction forces or mean pressures are within design boundaries for various service conditions of a ship. However, it is found that calculated bearing load can be substantially variable according to the locations of the effective support points of after sterntube bearing which are determined by simple calculation or assumption suggested by classification societies. A new analysis method for shaft alignment calculation is introduced in order to resolve these problems. Key concept of the new method is featured by adopting both nonlinear elastic and multi-support elements to simulate a bearing support Hertz contact theory is basically applied for nonlinear elastic stiffness calculation instead of the projected area method suggested by most of classification societies. Three loading conditions according to the bearing offset and the hydrodynamic moment and twelve models according to the locations of the effective support points of sterntube bearings are prepared to carry out quantitative verifications for an actual shafting system of 8000 TEU class container vessel. It is found that there is relatively large difference between assumed and calculated effective support points.

• 한국의류산업학회지
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• 제21권3호
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• pp.336-345
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• 2019

This study evaluated the preference and wearing characteristics of existing fitness compression wear for elderly women and identified the problems and improvements of existing fitness apparel. Preference and wearing characteristics for 6 types (A-F) of upper and lower fitness compression wear were evaluated. Photos and drawings as well as the preferred designs and details were investigated after presenting the evaluation clothing. Evaluations were made on a 5 point Likert scale for the fitness, allowance, pressure, ease of movement, fabric material, and overall satisfaction after wearing. The design preference indicated that B type (26.6%) and C type (23.4%) were preferred in the top with C, E and F type preferred to the same ratio of 19.4% in the slacks. The fitness and allowance amount of the top B type were the most appropriate (${\geq}4$), the C type was in close contact (2.86), and the F type was inadequate in the neck circumference (1.77). The feeling of pressure was high in the waist, abdomen, thighs, and knees. The area where the elderly people want to improve their strength was the legs; in addition, a pattern design was needed to strengthen leg muscles when designing fitness compression wear. However, a design with excessive adhesion due to a muscle support band was shown to be not preferred. Therefore, depending on the activity, it is necessary to develop a fitness compression wear that applies an optimum stretching ratio of fabric based on body surface area changes.

• 한국정보기술학회논문지
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• 제16권12호
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• pp.31-40
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• 2018

CAN(Controller Area Network) 모듈의 탑재 여부와 관계없이 각 회사의 농기계관리에 범용으로 적용할 수 있는 부착형의 스마트어댑터를 설계 및 구현하였다. 스마트어댑터는 리눅스 환경에서 농기계관리 소프트웨어가 동작하는 메인보드(라즈베리파이3B)와 전원 조정과 상태 센싱을 위하여 자체 개발한 인터페이스 보드로 구성된다. 상태 모니터링을 위하여 스마트어댑터와 농기계의 센서들 사이에 시리얼입력을 이용하는 센싱 인터페이스를 정의하였으며, 진단을 위하여 농기계의 상태 다이어그램을 정의하였다. 스위치의 온/오프 접점을 이용하여 농기계의 센서를 시뮬레이션 하는 판넬을 제작하였으며, 시뮬레이터 판넬에서 농기계의 각 상태를 입력함으로 상태 모니터링과 진단 기능을 확인하였다.

• 한국항공우주학회지
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• 제47권9호
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• pp.617-628
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• 2019

벤트홀로 연결된 두 개의 가변 체적 챔버를 가지고 있는 파이로테크닉 분리 너트는 복잡한 과정을 통해 분리를 수행하므로 많은 설계 인자를 가지고 있다. 접촉부의 각도, 구성품의 질량, 누름봉 돌출부 안쪽 지름, 환형 챔버의 초기 부피, 확장 챔버의 초기 부피, 화약질량, 벤트홀 지름과 같은 설계 인자들의 변화에 따라 분리 너트의 성능이 어떻게 달라지는지를 파악하면 설계 개선 방향을 결정하는데 도움이 될 수 있다. 이에, 선행 연구를 통해 개발한 파이로테크닉 분리 너트 거동 예측 모델을 이용하여 매개변수 연구를 수행하였다. 다른 설계 인자의 값은 고정한 상태에서 한 설계인자의 값을 독립적으로 변화시키며 분리 시간이 어떻게 달라지는지, 변화의 원인이 무엇인지를 분석하였다.

• 한국컴퓨터그래픽스학회논문지
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• 제25권4호
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• pp.1-8
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• 2019

본 논문에서는 젖은 헤어나 털에서 분사되는 액체의 디테일한 움직임을 표현할 수 있는 새로운 프레임워크를 제안한다. 젖은 헤어에서는 모발의 마찰력과 접착력 뿐만 아니라, 액체의 움직임도 마른 헤어에 비해 독특한 움직임을 갖는다. 하지만, 최근에 제안된 기법들도 모발의 접착력과 마찰력만을 고려했으며, 젖은 헤어에서 분사되는 액체의 움직임은 개선시키지 못했다. 이 문제는 헤어와 유체의 상호작용에서 표현되는 디테일한 특징을 잡아내지 못하기 때문에 결과의 품질을 저하시키는 원인이 된다. 본 논문의 주안점은 이 문제를 완화시켜 결과의 품질을 개선시키는 것이며, 결과적으로 FLIP(Fluid-implicit particle) 기반 유체 시뮬레이션과 헤어 입자 간의 상호작용을 효율적으로 표현할 수 있는 결합 프레임워크를 제안한다. 제안하는 방법은 이전 연구들에서 표현하지 못했던 곡선 형태로 분사되는 액체의 디테일한 움직임을 젖은 헤어 프레임워크에서 표현해냈다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.376-386
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• 2020

The aim of this study was to develop a new efficient strategy that uses the Vector form Intrinsic Finite-element (VFIFE) method to conduct the static and dynamic analyses of marine pipes. Nonlinear problems, such as large displacement, small strain, and contact and collision, can be analyzed using a unified calculation process in the VFIFE method according to the fundamental theories of point value description, path element, and reverse motion. This method enables analysis without the need to integrate the stiffness matrix of the structure, because only motion equations of particles established according to Newton's second law are required. These characteristics of the VFIFE facilitate the modeling and computation efficiencies in analyzing the nonlinear dynamic problem of flexible pipe with large deflections. In this study, a three-dimensional (3-D) dynamical model based on 3-D beam element was established according to the VFIFE method. The deep-sea flexible pipe was described by a set of spatial mass particles linked by 3-D beam element. The motion and configuration of the pipe are determined by these spatial particles. Based on this model, a simulation procedure to predict the 3-D dynamical behavior of flexible pipe was developed and verified. It was found that the spatial configuration and static internal force of the mining pipe can be obtained by calculating the stationary state of pipe motion. Using this simulation procedure, an analysis was conducted on the static and dynamic behaviors of the flexible mining pipe based on a 1000-m sea trial system. The results of the analysis proved that the VFIFE method can be efficiently applied to the static and dynamic analyses of marine pipes.

• Korean Journal of Chemical Engineering
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• 제35권11호
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• pp.2241-2255
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• 2018

RSM methodology was applied to present mathematical models for the fabrication of polyvinylidene fluoride (PVDF) dual-layer hollow fibers in membrane distillation process. The design of experiments was used to investigate three main parameters in terms of polymer concentration in both outer and inner layers and the flow rate of dope solutions by the Box-Behnken method. According to obtained results, the optimization was done to present the proper membrane with desirable properties. The characteristics of the optimized membrane (named HF-O) suggested by the Box-Behnken (at the predicted point) showed that the proposed models are strongly valid. Then, a morphology study was done to modify the fiber by a combination of three types of a structure such as macro-void, sponge-like and sharp finger-like. It also improved the hydrophobicity of outer surface from 87 to $113^{\circ}$ and the mean pore size of the inner surface from 108.12 to 560.14 nm. The DCMD flux of modified fiber (named HF-M) enhanced 62% more than HF-O when it was fabricated by considering both of RSM and morphology study results. Finally, HF-M was conducted for long-term desalination process up to 100 hr and showed stable flux and wetting resistance during the test. These stepwise approaches are proposed to easily predict the main properties of PVDF dual-layer hollow fibers by valid models and to effectively modify its structure.