• Proceedings of the Korea Society of Mathematical Education Conference
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• 2007.02a
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• pp.11-17
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• 2007

수학교육의 효율적인 체계가 없는 나라는 미래가 없는 나라이다. 1957년에 소련은 지구에 인공위성을 쏘아 올렸는데, 이때 미국은 우선 학교 교육체계를 바꾸었으며, 교사들의 봉급을 획기적으로 인상하였다. 지금 러시아의 학계에서는, 우주 계발에서 러시아의 성공을 레닌 언덕에 있는 모스크바국립대학교의 새 건물의 설립으로 설명하려는 의견도 있다. 최근에 모스크바국립대학교 새 건물의 설립 비용에 대한 문서가 공개되었는데, 놀랍게도 모스크바국립대학교의 설립 비용이 2차 대전 중에 완전히 파괴된 도시인 스탈린그라드의 재건에 소용된 비용보다 훨씬 많았다. 전쟁으로 굶주리고 파괴된 나라인 러시아의 지도자들이 그렇게 많은 재정적인 지출을 결정했다. 그 결과, 공학-수학부와 물리학부에서는 이전보다 3배가 많은 학생들을 수용하게 되었다. 이들 학부의 박사과정 학생들은 높은 월급을 받는 교수가 되었다. 공학-수학부의 거의 모든 졸업생들은 비밀연구소에서 일을 하였다. 이것은 러시아의 역사에서 수학 영재아의 발굴과 수학교육 체계의 향상이 국가경쟁력의 중요한 부분임을 보여주는 한 예라 할 수 있다. 현재, 러시아에서는 이들 문제에 많은 관심을 가지고 있지만, 아직은 구체적인 해결보다는 말만 무성한 실정이다. 본 강연에서는 러시아의 수학영재교육에서 모스크바국립대학교 구성원들의 노력과 결실, 모스크바국립대학교의 공학-수학부의 교육에 대한 몇몇 논의를 다룰 것이다.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.05a
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• pp.702-704
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• 2022

자율주행 시뮬레이터를 위한 대체재로 게임 엔진을 통한 가상 환경 모의 연구가 수행되고 있다. 하지만 게임 엔진에서는 자율 주행에 필요한 센서를 기기에 맞게 사용자가 직접 모델링을 해줘야 하기 때문에 개발 비용이 크게 작용된다. 특히, Ray 를 활용한 3D LIDAR 는 GPU(Graphics Processing Unit) 사용량이 많은 작업이기 때문에 저비용 시뮬레이터를 위해서는 저비용 3D LIDAR 모의가 필요하다. 본 논문에서는 낮은 컴퓨터 연산을 사용하는 C++ 기반 3D LIDAR 모의 프레임 워크를 제안한다. 제안된 3D LIDAR 는 다수의 언덕으로 이루어진 비포장 Map 에서 성능을 검증 하였으며, 성능 검증을 의해 본 논문에서 생성된 3D LIDAR 로 간단한 LPP(Local Path Planning) 생성 방법도 소개한다. 제안된 3D LIDAR 프레임 워크는 저비용 실시간 모의가 필요한 자율 주행 분야에 적극 활용되길 바란다.

• Korean Journal of Cognitive Science
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• v.25 no.2
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• pp.135-157
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• 2014

The present study investigated whether 6- and 12-month-old infants could infer an agent's social preference on the basis of intentions. In Experiment 1, 12-month-old infants were first familiarized with two kinds of event: the helping and the hindering events. In the helping event, an agent (either a square or triangle) tried to help a circle climb up the hill and the movie stopped right before the circle reached the top of the hill. Thus, the outcome of the helping behavior was made to be ambiguous. Similarly, in the hindering movie, another agent tried to hinder the circle from reaching the top of the hill and the movie stopped right before the circle slipped down to the base of the hill making the final outcome of the hindering behavior unclear. During the test trial, infants were either presented with an event in which the circle approached the helper (approach-helper condition) or an event in which the circle approached the hinderer (approach-hinderer condition). The results indicated that both 6- and 12-month-olds looked longer at the approach-helper event than at the approach-hinderer event. Thus, by 6 months of age, infants are sensitive to agents' intentions when reasoning about agents' social preference. The current findings add to the emerging evidence on social evaluation and moral reasoning during infancy.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.2
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• pp.37-45
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• 2012

Byeolseo was located in various places with beautiful natural scenery to avoid the mundane world and for country life in seclusion. In this study, to classify locational type and characteristics of Byeolseo in Gyeongsangnamdo and Jeollado areas, complex locational types and characteristics of total 96 Byeolseo (52 in Gyeongsangnamdo and 44 in Jeollado) were researched and cluster analysis was executed to group locational characteristics to several clusters with similar characteristics in order to classify locational types of Byeolseo. As the result, locational type for Gyeongangnam-do and Jeolla-do were classified to 5 types each. Unique locational types Gyeongsangnamdo were 'valley type' and 'cliff type' and unique ones for Jeollado were 'flatland type' and 'riverside.hill type'. 'Hill type', 'curvy river type' and 'riverside other type' were shown in both areas. In Gyeongangnamdo, 30.8% was cliff type and 15.4% was valley type 46.2% of the total was locatedon 'cliff near river' or 'valley'. These were the most popular locational characteristics of Gyeongangnamdo. Unlike Gyeongangnamdo, 18.2% was flatland type, 18.2% is riverside.hill type, and 39.6% was hill type in Jeollado 75.0% of the total was locatedon 'flatland', 'on hill near river' or 'on hils'. These were the most popular locational characteristics of Jeollado. Such locational characteristics showed that Byeolseo was located using nearby scenery considering topographic characteristics of the located area.

• Journal of the Korean Geotechnical Society
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• v.19 no.3
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• pp.53-64
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• 2003

Many transmission towers, high-rise buildings and bridges are constructed near steep slopes and are supported by large-diameter piles. These structures may be subjected to large lateral loads, such as violent winds and earthquakes. Widely used types of foundations for these structures are pier foundations, which have large-diameters with high stiffness. The behavior of a pier foundation subjected to lateral loads is similar to that of a short rigid pile because both elements seem to fail by rotation developing passive resistance on opposite faces above and below the rotation point, unlike the behavior of a long flexible pile. This paper describes the results of several numerical studies performed with a three-dimensional finite element method (FEM) of model tests of a laterally loaded short pile located near slopes, respectively. In this paper, the results of model tests of single piles and pile groups subjected to lateral loading, in homogeneous sand with 30$^{\circ}$ slopes and horizontal ground were analyzed by the 3-D FE analyses. The pile was assumed to be linearly elastic. The sand was assumed to have non-associative characteristics, following the MC-DP model. The failure criterion is governed by the Mohr-Coulomb equation and the plastic potential is given by the Drucker-Prager equation. The main purpose of this paper is the validation of the 3-D elasto-plastic FEM by comparisons with the experimental data.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6B
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• pp.643-651
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• 2008

In the present paper, turbulent open-channel flows over longitudinal bedforms are numerically simulated. The Reynolds- averaged Navier-Stokes equations in curvilinear coordinates are solved with the non-linear $k-{\varepsilon}$ model by Speziale( 1987). First, the developed model is applied to rectangular open channel flows for purposes of model validation and parameter sensitivity studies. It is found that the parameters $C_D$ and $C_E$ are important to the intensity of secondary currents and the level of turbulent anisotropy, respectively. It is found that the non-linear $k-{\varepsilon}$ model can hardly reproduce the turbulence anisotropy near the free surface. However, the overall pattern of the secondary currents by the present model is seen to coincide with measured data. Then, numerical simulations of turbulent flows over longitudinal bedforms are performed, and the simulated results are compared with the experimental data in the literature. The simulated secondary currents clearly show upflows and downflows over the ridges and troughs, respectively. The numerical results of secondary currents, streamwise mean velocity, and turbulence structures compare favorably with the measured data. However, it is observed that the secondary currents towards the troughs were significantly weak compared with the measured data.

• Explosives and Blasting
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• v.32 no.2
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• pp.25-30
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• 2014

Although the construction noise and vibration are transient and intermittent, their impact on the surrounding environment is huge. Since the construction equipment noise and vibration is usually transmitted because of the long distance, the sound insulation and the proper design of anti-vibration measures are very difficult. The regulation requires that the noise and vibration caused by the construction equipments should be measured within 30m from the source, whereas the blasting noise and vibration should be measured at least 60m and 160m away from the source, respectively. Instead of the 2D modelling mainly conducted so far, the 3D analysis of noise and vibration with the consideration of the height and size of the building, mountains and hills in the vicinity of the source is necessary.

• ETRI Journal
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• v.7 no.4
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• pp.3-10
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• 1985

After the light from an incoherent LED was transmitted through the multimode fibers which were linked over 10 km, the nearfield power distribution reached the steady-state independent of launching conditions. It has been also found that the steady-state output power distribution showed the pattern of Gaussian function. In this steady-state Gaussian function pattern, the measured losses of fibers were very repeatable values. In case of using LD source, the speckle phenomena in near -field power distribution appeared until the distance of 10 km. And the output power distribution did not reach the steady-state shown in LED even over 20km on account of the coherence and the nonuniform lasing modes of LD. But the measured losses of fibers were nearly stable in this long distance.

• The Transactions of the Korea Information Processing Society
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• v.3 no.7
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• pp.1773-1780
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• 1996

KBANN (knowledge-based artificial neural network) combining the symbolic approach and the numerical approach has been shown to be more effective than other machine learning models. However KBANN doesn't have the theory refinement ability because the topology of network can't be altered dynamically. Although TopGen was proposed to extend the ability of KABNN in this respect, it also had some defects due to the link-ing of hidden nodes to input nodes and the use of beam search. The algorithm which could solve this TopGen's defects, by adding the hidden nodes linked to next layer nodes and using hill-climbing search with backtracking, is designed.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.12 s.255
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• pp.1218-1227
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• 2006

In this paper a parametric study using an immersed boundary method has been carried out to investigate the effects of stable density stratification on the wakes past two identical three-dimensional hills aligned in tandem. The Reynolds number based on the uniform inlet velocity and twice the hill height was fixed at Re=300 while the Froude number based on the inlet velocity and the hill height was retained at Fr=0.2. Neutral flow without density stratification was also computed for comparison. Under a strong stratification, vertical motion of fluid particles over the three-dimensional hills is suppressed and the wake structures behind the hills become planar. Depending on the distance between the two hills, the flow pattern of each wake is significantly affected by the stratification. There is a critical hill distance at which flow characteristics drastically change. Qualitative and quantitative features of the wake interaction are reported.