• 한국학교수학회논문집
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• 제19권1호
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• pp.63-82
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• 2016

수학에서 표기는 수학의 힘을 깨닫게 하는 주요 수단이다. 이러한 관점 하에 본 연구는 무리수 개념 학습의 어려움을 표기의 관점에서 분석하고, 표기에서 비롯된 어려움을 극복할 수 있는 방안을 모색해 보았다. 근호를 사용한 무리수 표기에는 '무리수는 소수나 분수 표현이 불가하므로 문자로 표기해야 한다는 점'과 '$\sqrt{2}$의 경우에 제곱하면 2가 되는 특징을 부각하기 위해 문자에 수를 첨가한 표기'라는 정신이 깃들어 있다. 하지만 교과서에서는 무리수 표기에 대한 발견의 기회를 제공하지 않으므로 학습자는 근호 표기에 깃든 정신을 파악하기 어렵다. 더군다나 무리수 기호 발전 과정에서 문자의 투명성이 축소되어 개념적인 측면에서의 접근이 더욱 어렵게 되었다. 이런 이유로 '이중 맥락에 따른 인식론적 장애', '수치의 투명성 우세로 비롯된 인식론적 장애'가 예상된다. 인식론적 장애를 극복하기 위해서는 '표기 개발의 기회 제공', '문자의 투명성이 기존보다 강화된 표기 사용 경험'이 전제될 필요가 있으며, 본 연구에서는 이러한 원칙에 입각한 6단계의 방안을 제안하였다.

• Structural Engineering and Mechanics
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• 제9권3호
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• pp.241-256
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• 2000

The major sources of energy dissipation in steel frames with partially restrained (PR) connections are evaluated. Available experimental results are used to verify the mathematical model used in this study. The verified model is then used to quantify the energy dissipation in PR connections due to hysteretic behavior, due to viscous damping and at plastic hinges if they are formed. Observations are made for two load conditions: a sinusoidal load applied at the top of the frame, and a sinusoidal ground acceleration applied at the base of the frame representing a seismic loading condition. This analytical study confirms the general behavior, observed during experimental investigations, that PR connections reduce the overall stiffness of frames, but add a major source of energy dissipation. As the connections become stiffer, the contribution of PR connections in dissipating energy becomes less significant. A connection with a T ratio (representing its stiffness) of at least 0.9 should not be considered as fully restrained as is commonly assumed, since the energy dissipation characteristics are different. The flexibility of PR connections alters the fundamental frequency of the frame. Depending on the situation, it may bring the frame closer to or further from the resonance condition. If the frame approaches the resonance condition, the effect of damping is expected to be very important. However, if the frame moves away from the resonance condition, the energy dissipation at the PR connections is expected to be significant with an increase in the deformation of the frame, particularly for low damping values. For low damping values, the dissipation of energy at plastic hinges is comparable to that due to viscous damping, and increases as the frame approaches failure. For the range of parameters considered in this study, the energy dissipations at the PR connections and at the plastic hinges are of the same order of magnitude. The study quantitatively confirms the general observations made in experimental investigations for steel frames with PR connections; however, proper consideration of the stiffness of PR connections and other dynamic properties is essential in predicting the dynamic behavior.

• 논리연구
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• 제12권2호
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• pp.141-170
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• 2009

최근 1600년 경 예수회 아리스토텔레스주의자들 사이에서 벌어졌던 수학의 과학으로서의 지위에 관한 논쟁에 대한 관심이 급증하고 있다. 필자는 월러스, 디어, 그리고 만코수를 좇아 이 논쟁을 조금 더 자세히 살펴보고자 한다. 이를 위해 필자는 비앙카니가 수학의 본성에 관한 논고에서 중간과학을 논의한 바에 초점을 맞출 것이다. 디어와 월러스의 논의로부터 우리는 수학의 과학적 지위를 옹호한 이들과 부인한 이들 사이의 논쟁에 관한 비교적 훌륭한 조감도를 얻을 수 있다. 그러나 그 논쟁의 일반적 동기를 이해하는 일과 그 안에 내포된 변증적 전략과 전술의 정교함을 감식하는 일은 전혀 별개의 문제이다. 바로 이 단계에서 우리는 중간과학에 관한 비앙카니의 견해의 요점을 이해하는 데에서 어려움에 봉착한다. 비록 중간과학의 문제에 관해서는 침묵을 지켰지만, 만코수가 완벽한 증명, 수학적 설명, 그리고 원인의 문제에 관한 예수회 아리스토텔레스주의자들의 입장을 논의한 바는 역사적으로나 철학적으로나 모두 최고의 중요성을 지닌다. 필자는 그 논쟁에서 진실로 무엇이 쟁점이었는지를 보다 심도 있게 이해하기 위하여 피콜로미니와 비앙카니의 견해에 대한 만코수의 해석을 주의 깊게 검토하고 비판할 것이다.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제21권1호
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• pp.19-37
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• 2018

본 연구는 1, 2학년 수학교과서에 반영된 다문화 교육요소를 분석하기 위해 다문화 수학교육 요소 분석 틀을 개발하여 2015 개정 수학과 교육과정과 이를 바탕으로 한 교과서와 교사용 지도서를 분석하였다. 교육과정 총론에서는 '우리 문화의 정체성'이나 '지식의 다양성', '사회적 문제 해결'에 대한 다문화 교육 요소가 비교적 명확하게 드러나 있었지만, 수학과 교육과정에서는 '우리 문화의 정체성'이 나타나지 않았다. 그럼에도 불구하고 수학교과서에는 '사회적 문제해결'을 제외한 다문화 교육요소가 고루 나타나 있었다. 그러나 교과서에 적용된 다문화 교육 요소의 적용 수준은 대부분 낮게 나타났으며 교과서에 제시된 다른 나라의 수학사나 문화가 지나치게 유럽 중심이라는 문제점이 있었다. 또한 교과서에는 다문화 학생이나 장애인, 타인종은 찾아볼 수 없었다. 이러한 연구 결과를 바탕으로 수학 교과에서 다문화 교육이 활성화 될 수 있도록 다음 교과서를 제작하는데 있어서 시사점을 제공하고자 하였다.

• 한국초등수학교육학회지
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• 제15권1호
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• pp.77-93
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• 2011

지수귀문도는 지금으로부터 약 300여년 전에 최석정이 <구수략>에서 소개한 마법육각진이다. 작금에 지수귀문도에 관심이 모아지고 있고, 마법수가 76부터 110 인 경우에 지수귀문도가 존재할 수 있다는 것이 증명되기는 했지만, 그것을 만드는 일반적인 방법은 아직도 알려지지 않았다. 현재까지는 컴퓨터를 이용하여 지수귀문도를 만드는 방법이 알려져 있을 뿐이다. 본 연구에서는 마법수가 88~92, 94~98 인 경우에 한정하여, 컴퓨터의 도움을 받지 않고, 초등학교에서도 문제해결 활동의 일환으로 지수귀문도를 만들 수 있는 방안으로 교호법을 제안한다. 이를 위해 교호법이 작동되는 수학적 이론을 소개하고, 그것을 이용해서 만들 수 있는 지수귀문도를 제시한다. 본 연구에서는 교호법을 통하여 초등학생들도 자신만의 지수귀문도를 만들 수 있을 것으로 기대한다.

• 국제초고층학회논문집
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• 제1권4호
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• pp.311-332
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• 2012

Earthquake response of mid-rise to high-rise buildings provided with friction dampers is investigated. The steel buildings are modelled as shear-type structures and the investigation involved modelling of the structures of varying heights ranging from five storeys to twenty storeys, in steps of five storeys, subjected to real earthquake ground motions. Three basic types of structures considered in the study are: moment resisting frame (MRF), braced frame (BF), and friction damper frame (FDF). Mathematical modelling of the friction dampers involved simulation of the two distinct phases namely, the stick phase and the slip phase. Dynamic time history analyses are carried out to study the variation of the top floor acceleration, top floor displacement, storey shear, and base-shear. Further, energy plots are obtained to investigate the energy dissipation by the friction dampers. It is seen that substantial earthquake response reduction is achieved with the provision of the friction dampers in the mid-rise and high-rise buildings. The provision of the friction dampers always reduces the base-shear. It is also seen from the fast Fourier transform (FFT) of the top floor acceleration that there is substantial reduction in the peak response; however, the higher frequency content in the response has increased. For the structures considered, the top floor displacements are lesser in the FDF than in the MRF; however, the top floor displacements are marginally larger in the FDF than in the BF.

• Parasites, Hosts and Diseases
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• 제45권4호
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• pp.273-282
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• 2007

In acute uncomplicated falciparum malaria, there is a continuum from mild to severe malaria. However, no mathematical system is available to predict uncomplicated falciparum malaria patients turning to severe malaria. This study aimed to devise a simple and reliable model of Malaria Severity Prognostic Score (MSPS). The study was performed in adult patients with acute uncomplicated falciparum malaria admitted to the Bangkok Hospital for Tropical Diseases between 2000 and 2005. Total 38 initial clinical parameters were identified to predict the usual recovery or deterioration to severe malaria. The stepwise multiple discriminant analysis was performed to get a linear discriminant equation. The results showed that 4.3% of study patients turned to severe malaria. The MSPS = 4.38 (schizontemia) + 1.62 (gametocytemia) + 1.17 (dehydration) + 0.14 (overweight by body mass index; BMI) + 0.05 (initial pulse rate) + 0.04 (duration of fever before admission)-0.50 (past history of malaria in last 1 year). 0.48 (initial serum albumin)-5.66. Based on the validation study in other malaria patients, the sensitivity and specificity were 88.8% and 88.4%, respectively. We conclude that the MSPS is a simple screening tool for predicting uncomplicated falciparum malaria patients turning to severe malaria. However, the MSPS may need revalidation indifferent geographical areas before utilized at specific places.

• Earthquakes and Structures
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• 제16권6호
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• pp.715-726
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• 2019

Several municipal seismic vulnerability investigations have been identified pounding of adjacent structures as one of the main hazards due to the constrained separation distance between adjacent buildings. Consequently, an assessment of the seismic pounding risk of buildings is superficial in future adjustment of design code provisions for buildings. The seismic lateral oscillation of adjacent buildings with eccentric alignment is partly restrained, and therefore a torsional response demand is induced in the building under earthquake excitation due to eccentric pounding. In this paper, the influence of the eccentric seismic pounding on the design demands for adjacent symmetric buildings with eccentric alignment is presented. A mathematical simulation is formulated to evaluate the eccentric pounding effects on the seismic design demands of adjacent buildings, where the seismic response analysis of adjacent buildings in series during collisions is investigated for various design parameters that include number of stories; in-plan alignment configurations, and then compared with that for no-pounding case. According to the herein outcomes, the effects of seismic pounding severity is mainly depending on characteristics of vibrations of the adjacent buildings and on the characteristics of input ground motions as well. The position of the building wherever exterior or interior alignment also, influences the seismic pounding severity as the effect of exposed direction from one or two sides. The response of acceleration and the shear force demands appear to be greater in case of adjacent buildings as seismic pounding at different levels of stories, than that in case of no-pounding buildings. The results confirm that torsional oscillations due to eccentric pounding play a significant role in the overall pounding-involved response of symmetric buildings under earthquake excitation due to horizontal eccentric alignment.

• International Journal of Computer Science & Network Security
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• 제22권2호
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• pp.406-412
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• 2022

Storing large amounts of data has always been a big problem from the beginning of computing history. Big Data has made huge advancements in improving business processes by finding the customers' needs using prediction models based on web and social media search. The main purpose of big data stream processing frameworks is to allow programmers to directly query the continuous stream without dealing with the lower-level mechanisms. In other words, programmers write the code to process streams using these runtime libraries (also called Stream Processing Engines). This is achieved by taking large volumes of data and analyzing them using Big Data frameworks. Streaming platforms are an emerging technology that deals with continuous streams of data. There are several streaming platforms of Big Data freely available on the Internet. However, selecting the most appropriate one is not easy for programmers. In this paper, we present a detailed description of two of the state-of-the-art and most popular streaming frameworks: Apache Ignite and Hazelcast. In addition, the performance of these frameworks is compared using selected attributes. Different types of databases are used in common to store the data. To process the data in real-time continuously, data streaming technologies are developed. With the development of today's large-scale distributed applications handling tons of data, these databases are not viable. Consequently, Big Data is introduced to store, process, and analyze data at a fast speed and also to deal with big users and data growth day by day.

• 천문학회보
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• 제45권1호
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• pp.38.2-38.2
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• 2020

Horizon Run 5 (HR5) is a cosmological hydrodynamical simulation which captures the properties of the Universe on a Gpc scale while achieving a resolution of 1 kpc. This enormous dynamic range allows us to simultaneously capture the physics of the cosmic web on very large scales and account for the formation and evolution of dwarf galaxies on much smaller scales. Inside the simulation box. we zoom-in on a high-resolution cuboid region with a volume of 1049 × 114 × 114 Mpc3. The subgrid physics chosen to model galaxy formation includes radiative heating/cooling, reionization, star formation, supernova feedback, chemical evolution tracking the enrichment of oxygen and iron, the growth of supermassive black holes and feedback from active galactic nuclei (AGN) in the form of a dual jet-heating mode. For this simulation we implemented a hybrid MPI-OpenMP version of the RAMSES code, specifically targeted for modern many-core many thread parallel architectures. For the post-processing, we extended the Friends-of-Friend (FoF) algorithm and developed a new galaxy finder to analyse the large outputs of HR5. The simulation successfully reproduces many observations, such as the cosmic star formation history, connectivity of galaxy distribution and stellar mass functions. The simulation also indicates that hydrodynamical effects on small scales impact galaxy clustering up to very large scales near and beyond the baryonic acoustic oscillation (BAO) scale. Hence, caution should be taken when using that scale as a cosmic standard ruler: one needs to carefully understand the corresponding biases. The simulation is expected to be an invaluable asset for the interpretation of upcoming deep surveys of the Universe.