• 한국측량학회지
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• 제27권2호
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• pp.169-175
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• 2009

측량법 개정으로 측량의 기준이 세계측지계로 변함에 따라, 1/1,000 수치지형도를 세계좌표계로 전환이 필요한 시점에서 측지기준의 전환에 따른 혼란과 오차를 최소화하기 위해 통일되고, 표준화된 전략이 요구 된다. 본 연구에서는 부산광역시의 UIS 사업당시 1/1,000 수치지형도와 지역측지계 및 세계측지계 좌표를 확보하여 공통점으로 사용하여, 좌표변환프로그램인 KASM Trans Ver2.2를 사용하여 왜곡량 분석을 실시하였다. 부산지역 전체에 대한 왜곡량을 계산한 결과, 0.05m 이상의 차이를 나타내는 부분이 X(E) 35점, Y(E)이 43점 발생하였다. 왜곡량이 발생하는 부분을 고려하여 A,B,C 3개 지역으로 분할하여 왜곡량을 분석한 결과 0.05m 이상 오차를 나타내는 부분이 B지역 Y(E) 1점,C지역 X(N) 1점, Y(E) 1점으로 크게 줄어들었다. 따라서 부산광역시의 세계좌표계 변환은 왜곡량을 고려하여 지역별로 나누어 변환하는 것이 좋을 것으로 사료된다.

• 대한수학회지
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• 제32권3호
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• pp.427-446
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• 1995

Let S be a set and B be a $\sigma$-field on S. We consider $(\Omega = S^Z, T = B^z, P)$ as the basic probability space. We denote by T the left shift on $\Omega$. We assume that P is invariant under T, i.e., $PT^{-1} = P$, and that T is ergodic. We denote by $X = \cdots, X_-1, X_0, X_1, \cdots$ the coordinate maps on $\Omega$. From our assumptions it follows that ${X_i}_{i \in Z}$ is a stationary and ergodic process.

• 대한수학회지
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• 제33권4호
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• pp.983-992
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• 1996

Let p(x, dy) be a transition probability function on $(S, \rho)$, where S is a complete separable metric space. Then a Markov process $X_n$ which has p(x, dy) as its transition probability may be generated by random iterations of the form $X_{n+1} = f(X_n, \varepsilon_{n+1})$, where $\varepsilon_n$ is a sequence of independent and identically distributed random variables (See, e.g., Kifer(1986), Bhattacharya and Waymire(1990)).

• 대한수학회지
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• 제32권1호
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• pp.33-40
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• 1995

A space Y is called finitely dominated if there is a finite complex K such that Y is a retract of K in the homotopy category, i.e., we require maps $i : Y \longrightarrow K and r : K \longrightarrow Y with r \circ i \simeq idy$. The following questions are very classical in topology.

• 대한수학회보
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• 제50권4호
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• pp.1345-1356
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• 2013

In this paper, we study rotational and helicoidal surfaces in Euclidean 3-space in terms of their Gauss map. We obtain a complete classification of these type of surfaces whose Gauss maps G satisfy $L_1G=f(G+C)$ for some constant vector $C{\in}\mathbb{E}^3$ and smooth function $f$, where $L_1$ denotes the Cheng-Yau operator.

• 대한수학회보
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• 제30권2호
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• pp.201-212
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• 1993

It is our purpose in this paper to first establish an inequality in real uniformly smooth Banach spaces with modulus of smoothness of power type q > 1 that generalizes a well known Hilbert space inequality. Using our inequality, we shall then extend the above result of Qihou [15] on the Ishikawa iteration process from Hilbert spaces to these much more general Banach spaces. Furthermore, we shall prove that the Mann iteration process converges strongly to the unique fixed point of a quasi-contractive map in this general setting. No compactness assumption on K is required in our theorems.

• 대한기계학회논문집A
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• 제32권2호
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• pp.186-193
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• 2008

[ $Moir{\acute{e}}$ ] interferometry is an optical method, providing whole field contour maps of in-plane displacements with high resolution. The demand for enhanced sensitivity in displacement measurements leads to the technique of microscopic $moir{\acute{e}}$ interferometry. The method is an extension of the $moir{\acute{e}}$ interferometry, and employs an optical microscope for the required spatial resolution. In this paper, the sensitivity of $moir{\acute{e}}$ interferometry is enhanced by an order of magnitude using an immersion interferometry and the optical/digital fringe multiplication(O/DFM) method. In fringe patterns, the contour interval represents the displacement of 52 nm per fringe order. In order to estimate the reliability and the applicability of the optical system implemented, the measurements of rigid body displacements of grating mold and the coefficient of thermal expansion(CTE) for an aluminium block are performed. The system developed is applied to the measurement of thermal deformation in a flip chip plastic ball grid array package.

• Asia pacific journal of information systems
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• 제32권3호
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• pp.656-683
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• 2022

The COVID-19 pandemic has profoundly affected the world, inflicting nationwide lockdowns interrupting conventional schooling through schools, colleges and universities. Educational institutions are struggling to maintain learning continuity through remote learning solutions. Still, the students' perception of this 'new normal' mode and pace of learning needs to be examined to ensure the success of these efforts. This study aimed at examining the perception of higher education students in India and Croatia especially with respect to the association between cultural orientation and the e-learning. The period considered for the data collection was from March 2020 to September 2020. Correspondence analysis was attempted to create spatial maps to depict the respondent choices. Students from both the regions agreed to the high-power distance that existed in their cultures and considered the role of device and content to be an important dimension of e-learning for it to be effective, but the results also pointed out some differences in their choices on other culture dimensions as well as factors affecting e-learning which make this study unique and suggest in-depth future research for conclusive results.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제32권1호
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• pp.37-57
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• 2018

수학교육에서 Concept Map(개념그림)을 활용하기 시작한 초기에는 Concept Map이라는 그림 안에 수학적 아이디어를 어떻게 표상할 수 있느냐에 초점이 맞추어져 있었다. 하지만, 최근 연구에 따르면 Concept Map이 문제해결력과 밀접한 관련이 있다. 구체적으로 Concept Map은 학생들 사이의 협력적 문제해결의 도구, 문제를 탐구하기 위한 도구, 문제의 구조를 소개하기 위한 도구, 지식의 체계를 개발하고 체계화하는 도구 등으로 사용될 수 있다. 이에 본 연구에서는 Concept Map에 대한 선행연구 분석을 기반으로 Concept Map을 활용한 수학 문제의 구조 분석에 집중하였다. 그 결과 수학 문제 구조 분석을 위한 Concept Map의 활용 방법을 개발하였고, 개발된 자료를 적용하여 실제 수학 문제 분석에 적용함으로써 그 실현 가능성을 확인하였다. 본 연구 결과를 통해 수학 문제 구조의 파악, 수학과 교육과정 및 교과서와 일관성 있는 문제의 개발, 수학 문제의 난이도 분석 등에 효과적으로 활용될 것으로 기대된다.

• 상하수도학회지
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• 제33권2호
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• pp.151-158
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• 2019

Objectives of this study were to identify the hotspot for displacement of the on-line water quality sensors, in order to detect illicit discharge of untreated wastewater. A total of twenty-six water quality parameters were measured in sewer networks of the industrial complex located in Daejeon city as a test-bed site of this study. For the water qualities measured on a daily basis by 2-hour interval, the self-organizing maps(SOMs), one of the artificial neural networks(ANNs), were applied to classify the catchments to the clusters in accordance with patterns of water qualities discharged, and to determine the hotspot for priority sensor allocation in the study. The results revealed that the catchments were classified into four clusters in terms of extent of water qualities, in which the grouping were validated by the Euclidean distance and Davies-Bouldin index. Of the on-line sensors, total organic carbon(TOC) sensor, selected to be suitable for organic pollutants monitoring, would be effective to be allocated in D and a part of E catchments. Pb sensor, of heavy metals, would be suitable to be displaced in A and a part of B catchments.