• Journal of Positioning, Navigation, and Timing
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• 제10권4호
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• pp.235-242
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• 2021

Unmanned Aerial Vehicles (UAVs), which were used for military purposes, are gradually expanding their application fields under the influence of electrification and digitalization. Starting from the field of aerial imaging and Intelligence Surveillance and Reconnaissance (ISR) mission, nowadays the possibility of Urban Air Mobility (UAM), which transports passengers and cargo with drones, is widely under discussion. In order to occupy the rapidly growing global unmanned aerial vehicle market in advance, it is necessary to secure core technologies and develop key UAVs components based on the new technologies. In the navigation field, it is necessary to secure a precise position with guaranteed reliability and continuity, unrelated to the operating environments. The reliability and continuity should be secured in the algorithm level and in the H/W component levels also. In order to achieve this technical goal, the Ministry of Science and ICT has launched the 'Unmanned Vehicle Core Technology Research and Development Program' in 2019 to support the R&D on the unmanned vehicle technologies. In this paper, authors introduce the unmanned vehicle core technology research and development program to the related researchers. The authors summarize the backgrounds of the program and show the technological tasks and objectives on the sub-programs in the unmanned vehicle navigation program. We present the program schedules especially focused on the test and evaluation of the developed technologies and components.

• 현장농수산연구지
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• 제15권1호
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• pp.107-121
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• 2013

This study was developed to investigate the effects of privately owned public space (POPS) on urban streetscape and to find ways to prevent the discontinuation of street continuity on urban landscape when creating POPS in urban space and the surrounding streets. Several case studies and policies and laws related to POPS were reviewed to identify the practical problems as well as current state. An additional analysis was conducted on the different types of POPS to examine spatial connections between them and streetscapes and to find ways to improve POPS on urban streetscape. Our results show that POPS surrounding a building (i.e. frontage space and adjacent sidewalks) should be considered as one space in the integrated perspective. In addition, the type of facilities installed on POPS would be decided according to whether POPS is recognized as the part of public rest area or treated as the part of street. The results of the study will serve as useful data to solve the current problems with city's POPS, which destroys spatial continuity by focusing on increasing the number of POPS and creates high-rise buildings isolated from existing spaces. This study will also contribute to improve the quality of future POPS.

• 한국산학기술학회논문지
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• 제12권1호
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• pp.91-99
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• 2011

성인학습자는 일반적으로 자기조절학습이 뛰어나 학업성취도와 학업지속성이 높지만, 온라인 교육 환경에서는 오랜 기간 학습의 중단과 과거 집합교육에 익숙하여 성인학습자의 장점인 자기조절학습이 쉽지 않아 학업저하 및 학업포기 현상이 발생되고 있다. 본 연구에서는 자기조절학습과 UDL설계 학습모형을 개발하고 이것을 적용한 e-멘토링 시스템을 구축하였다. 실험결과를 분석하기 위하여 연구자는 H 사이버대학교 신.편입 학습자를 대상으로 통제집단과 실험집단으로 구분하고 집단별 100명을 대상으로 학습동기전략질문지(MSLQ)를 기반으로 총 36문항의 질문지로 구성된 학업만족도 설문조사를 하였으며, 학업성취도와 학업지속성에 대한 영향을 알고자 1학기의 성적, 재등록률, 학습시간을 추출하였다. 상관분석 결과는 실험집단에서 만족도가 높을수록 학업성취도(성적)와 학업지속성(재등록률, 학습시간)이 높음을 보이고 있다 본 연구의 결과로 원격대학교 성인학습자들에게 새로운 형태의 e-러닝 교육 부적응 문제를 해결을 할 수 있는 방향과 기준을 제시할 수 있을 것이다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2007년도 춘계학술대회 학술발표 논문집 제17권 제1호
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• pp.209-212
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• 2007

Non-additive measures and their corresponding Choquet integrals are very useful tools which are used in both insurance and financial markets. In both markets, it is important to to update prices to account for additional information. The update price is represented by the Choquet integral with respect to the conditioned non-additive measure. In this paper, we consider a price functional H on interval-valued risks defined by interval-valued Choquet integral with respect to a non-additive measure. In particular, we prove that if an interval-valued pricing functional H satisfies the properties of monotonicity, comonotonic additivity, and continuity, then there exists an two non-additive measures ${\mu}_1,\;{\mu}_2$ such that it is represented by interval-valued choquet integral on interval-valued risks.

• 한국전산유체공학회지
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• 제13권3호
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• pp.51-61
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• 2008

The SMAC (Simplified Marker And Cell) algorithm is extended for an application to thermal non-equilibrium two-phase flows in light water nuclear reactors (LWRs). A two-fluid three-field model is adopted and a multi-dimensional unstructured grid is used for complicated geometries. The phase change and the time derivative terms appearing in the continuity equations are implemented implicitly in a pressure correction equation. The energy equations are decoupled from the momentum equations for faster convergence. The verification of the present numerical method was carried out against a set of test problems which includes the single and the two-phase flows. The results are also compared to those of the semi-implicit ICE method, where the energy equations are coupled with the momentum equation for pressure correction.

• Journal of Biosystems Engineering
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• 제19권1호
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• pp.42-49
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• 1994

Texturization of plant protein means the physical or chemical recomposition method of plant protein damaged during the extracting process of soybean oil. As a stable protein supplement, substituted for meat, needs of texturized products have been increased. Twin screw extruder is a very effective tool for texturization process as a physical method. This research, using defatted soy flour as raw material and twin screw extruder manufactured in domestic, showed that plant protein was texturized successfully on the operating conditions of barrel temperature of $120{\sim}140^{\circ}C$, material feed rate of 30~36kg/hr and water content of 20~25%. It also showed that the shape of die affected the texturization continuity.

• Steel and Composite Structures
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• 제24권5호
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• pp.537-548
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• 2017

In this paper presents bending characteristic of single wall carbon nanotube reinforced functionally graded composite (SWCNTRC-FG) plates. The finite element implementation of bending analysis of laminated composite plate via well-established higher order shear deformation theory (HSDT). A seven degree of freedom and $C^0$ continuity finite element model using eight noded isoperimetric elements is developed for precise computation of deflection and stresses of SWCNTRC plate subjected to sinusoidal transverse load. The finite element implementation is carried out through a finite element code developed in MATLAB. The results obtained by present approach are compared with the results available in the literatures. The effective material properties of the laminated SWCNTRC plate are used by Mori-Tanaka method. Numerical results have been obtained with different parameters, width-to-thickness ratio (a/h), stress distribution profile along thickness direction, different SWCNTRC-FG plate, boundary condition, through the thickness (z/h) ratio, volume fraction of SWCNT.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.6-9
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• 2011

In this study, the two-phase incompressible flow in two-dimensional channel considering the effect of surface tension is simulated using an improved level-set method. Quadratic element is used for solving the continuity and Navier-Stokes equations to avoid using an additional pressure equation, and Crank-Nicholson scheme and linear element are used for solving the advection equation of the level set function. Direct approach method using geometric information is implemented instead of the hyperbolic-type partial differential equation for the reinitializing the level set function. The benchmark test case considers various arrays of defomable droplets under different flow conditions in straight channel. The deformation and migration of the droplets are computed and the results are compared very well with the existing studies.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.10-13
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• 2011

A level set method is proposed to simulate the incompressible two-phase flow considering the effect of surface tension. For reinitialization of level set junction, a direct approach method is employed, instead of solving hyperbolic type equation. A mixed element is adopted, so that the continuity mid Navier-Stokes equations are solved by using the quadratic elements (six-node triangular element mid nine-node quadrilateral element), mid the level set function is solved by using the linear elements (three-node triangular element mid four-node quadrilateral element). In order to verify the accuracy mid robustness of the codes, the present methods are applied to a few benchmark problems. It is confirmed that the present results are in good qualitative mid quantitative agreements with the existing studies.

• 통합자연과학논문집
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• 제6권1호
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• pp.46-52
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• 2013

In this thesis, we consider isoparametric curves of quadratic F-B$\acute{e}$zier curves. F-B$\acute{e}$zier curves unify C-B$\acute{e}$zier curves whose basis is {sint, cos t, t, 1} and H-B$\acute{e}$zier curves whose basis is {sinht, cosh t, t,1}. Thus F-B$\acute{e}$zier curves are more useful in Geometric Modeling or CAGD(Computer Aided Geometric Design). We derive the relation between the quadratic F-B$\acute{e}$zier curves and the quadratic rational B$\acute{e}$zier curves. We also obtain the geometric properties of isoparametric curve of the quadratic F-B$\acute{e}$zier curves at both end points and prove the continuity of the isoparametric curve.