• 제목/요약/키워드: power-laws

검색결과 265건 처리시간 0.023초

중학교 2학년 학생들의 지수법칙 발견을 위한 교수 설계 및 적용 (Design of Instruction Helping 8th Grade Students Discover the Power Laws and its Application)

  • 강정기
    • 대한수학교육학회지:수학교육학연구
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    • 제27권2호
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    • pp.171-189
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    • 2017
  • 본 연구는 학생의 지수법칙 개발을 골자로 하는 교수법을 설계 및 적용해봄으로써 수업의 실제를 파악해 보고자 하였다. 이를 위해 중학교 2학년 54명의 학생을 대상으로 지수법칙에 대한 발견식 수업을 계획하여 적용해 보았다. 그 결과 지수법칙 사례 개발측면에서는 단조로운 법칙의 과다 생산, 선행학습의 경험이 없는 학생일수록 개발 유형이 다양하며 오류 가능성이 높아지는 경향, 여러 형태의 오류 등을 목격할 수 있었다. 법칙의 일반화와 표현 측면에서는 $a^m{\div}a^n$ 유형의 일반화 표현에 모두 실패하였으며, 밑이나 지수 중 하나만 문자로 일반화한 표현이 적지 않게 등장하였다. 또한 일반성이 제한된 오류나 변수와 등호를 사용하지 않은 표현 오류를 접할 수 있었다. 수업의 설문에서는 창조의 막연함을 호소하는 입장과 창조의 즐거움을 이야기하는 상반된 두 입장이 있었다. 이러한 결과에 기초하여 지수법칙 발견과 관련한 교수학적 시사점에 대해 논의하였다.

Preparation of the Applicable Regulatory Guideline on Mixed Waste in Korea Based on the Analysis of US Laws and Regulations

  • Sim, Eun-Jin;Lee, Sun-Kee;Kim, Chang-Lak;Kim, Tae-Man
    • 방사성폐기물학회지
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    • 제19권1호
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    • pp.141-160
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    • 2021
  • Unit 1 of the Kori Nuclear Power Plant (NPP) and Unit 1 of the Wolsong NPP are being prepared for decommissioning; their decommissioning is expected to generate large amounts of intermediate-level, low-level, and very low level Waste. Mixed waste containing both radioactive and hazardous substances is expected to be produced. Nevertheless, laws and regulations, such as the Korean Nuclear Safety Act and Waste Management Act, do not define clear regulatory guidelines for mixed waste. However, the United States has strictly enforced regulations on mixed waste, focusing on the human health and environmental effects of its hazardous components. The U.S. Nuclear Regulatory Commission and the U.S. Department of Energy regulate the radioactive components of mixed waste under the Atomic Energy Act. The U.S. Environmental Protection Agency regulates the hazardous waste component of mixed waste under the Resource Conservation and Recovery Act. In this study, the laws, regulations, and authorities pertaining to mixed waste in the United States are reviewed. Through comparison and analysis with waste management laws and regulations in Korea, a treatment direction for mixed waste is suggested. Such a treatment for mixed waste will increase the efficiency of managing mixed waste when decommissioning NPPs in the near future.

Investigation of the Sensitivity Depletion Laws for Rhodium Self-Powered Neutrorn Detectors (SPNDs)

  • Kim, Gil-Gon;Cho, Nam-Zin
    • Nuclear Engineering and Technology
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    • 제33권2호
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    • pp.121-131
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    • 2001
  • An investigation of the sensitivity depletion laws for rhodium SPNDs was performed to reduce the uncertainty of the sensitivity depletion laws used in Combustion Engineering (CE) reactors and to develop calculational tools that provide the sensitivity depletion laws to interpret the signal of the newly designed rhodium SPND into the local neutron flux. The calculational tools developed in this work are computer programs for a time-dependent neutron flux distribution in the rhodium emitter during depletion and for a time-dependent beta escape probability that a beta particle generated in the emitter escapes into the collector. These programs provide the sensitivity depletion laws and show the reduction of the uncertainty by about 1 % compared to that of the method employed by CE in interpreting the signal into the local neutron flux. A reduction in the uncertainty by 1 % in interpreting the signal into the local neutron flux reduces the uncertainty tv about 1 % in interpreting the signal into the local power and lengthens the lifetime of the rhodium SPND by about 10% or more.

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THE CONVERGENCE RATES IN THE ASYMMETRIC LAWS OF LARGE NUMBER FOR NEGATIVELY ASSOCIATED RANDOM FIELDS

  • Ko, Mi-Hwa
    • 호남수학학술지
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    • 제34권2호
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    • pp.209-217
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    • 2012
  • Convergence rates in the law of large numbers for i.i.d. random variables have been generalized by Gut[Gut, A., 1978. Marc inkiewicz laws and convergence rates in the law of large numbers for random variables with multidimensional indices, Ann. Probab. 6, 469-482] to random fields with all indices having the same power in the normalization. In this paper we generalize these convergence rates to the identically distributed and negatively associated random fields with different indices having different power in the normalization.

Similitudes for the structural response and radiated sound power of simply supported plates

  • Robin, Olivier;Margherita, Pasquale;De Rosa, Sergio;Berry, Alain;Franco, Francesco;Ciappi, Elena
    • Advances in aircraft and spacecraft science
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    • 제6권6호
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    • pp.443-461
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    • 2019
  • This communication investigates exact and distorted similitudes and the related scaling laws for the analysis of both dynamic response and radiated power of rectangular plates. The response of a given panel in similitude from another one is determined from a generalization of the modal approach, allowing the use of mode shapes, natural frequencies and finally radiation functions in order to establish appropriate scaling laws. Analytical models of simply supported rectangular plates are used to produce both original and replica model responses under point mechanical excitation. Emphasis is then especially put on laboratory experiments which are performed on baffled simply supported aluminum panels under mechanical excitations. All the six possible scaling directions, i.e. predicting a plate vibroacoustic reponse from another plate, are reported. All obtained results show that structural response or radiated sound power of a given plate can be both recovered with satisfactory accuracy by using the related scaling laws, even if parent models are used.

BGP 밸리-프리 라우팅 정책에 기반한 국내 AS 레벨 인터넷 토폴로지의 파워-로 지수 (Power-Laws Exponents of the Domestic AS-level Internet Topology based on the Valley-free BGP Routing Policy)

  • 강구홍
    • 인터넷정보학회논문지
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    • 제11권4호
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    • pp.41-49
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    • 2010
  • Faloutsos et al.[1,2]은 파워-로(power-law)를 이용해 노드 차수와 같은 Autonomous System (AS) 레벨 인터넷 토폴로지 특성의 중꼬리(heavy-tailed) 분포를 성공적으로 나타내었다. 이러한 결과는 파워-로 지수(exponents)를 이용해 이들 인터넷 토폴로지 특성을 간단 명료하게 나타낼 수 있게 한다. 본 논문에서는 BGP 밸리-프리 라우팅 정책에 기반한 국내 AS 레벨 인터넷 토폴로지 속성 - 노드 차수, 홉 수에 따른 노드 쌍의 수, 그리고 그래프의 고유치 - 의 파워-로 지수를 조사하였다. UCLA IRL 연구실이 제공하는 실제 AS 레벨 데이터 셋을 이용하였으며 이들 파워-로 근사는 상관계수(correlation coefficient)가 각각 90.7%, 96.5%, 그리고 97%로 조사되었다. 특히, 실질적인 AS 레벨 토폴로지 직경이 3홉 이내에 존재하는 AS 노드 쌍이 전체 91% 이상이며, 따라서 국내 AS 레벨 토폴로지가 비교적 잘 정리된 것으로 판단된다.

FG-based computational fracture of frequency up-conversion for bistablity of rotating shell: An effective numerical scheme

  • Hussain, Muzamal
    • Advances in concrete construction
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    • 제13권5호
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    • pp.367-376
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    • 2022
  • Theoretical study of vibration distinctiveness of rotating cylindrical are examined for three volume fraction laws viz.: polynomial, exponential and trigonometric. These laws control functionally graded material composition in the shell radius direction. Functionally graded materials are controlled from two or more materials. In practice functionally graded material comprised of two constituent materials is used to form a cylindrical shell. For the current shell problem stainless steel and nickel are used for the shell structure. A functionally graded cylindrical shell is sanctioned into two types by interchanging order of constituent materials from inner and outer side for Type I and Type II cylindrical shell arrangement. Fabric composition of a functionally graded material in a shell thickness direction is controlled by volume fraction law. Variation of power law exponent brings change in frequency values. Influence of this physical change is investigated to evade future complications. This procedure is capable to cater any boundary condition by changing the axial wave number. But for simplicity, numerical results have been evaluated for clamped- simply supported rotating cylindrical shells. It has been observed from these results that shell frequency is bifurcated into two parts: one is related to the backward wave and other with forward wave. It is concluded that the value of backward frequency is some bit higher than that forward frequency. Influence of volume fraction laws have been examined on shell frequencies. Backward and forward frequency curves for a volume fraction law are upper than those related to two other volume fraction laws. The results generated furnish the evidence regarding applicability of present shell model and also verified by earlier published literature.

한국기술혁신연구의 인용문헌 법칙과 의사 영향력지수 (Citation Laws and Quasi-Impact Factor on Innovation Studies in Korea)

  • 박정민;설성수;남수현
    • 정보관리연구
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    • 제40권4호
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    • pp.135-150
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    • 2009
  • 계량서지학은 오랫동안 잘 정의된 과학저널의 기초 위에서 구축되었다. 그러나 한국의 기술혁신연구의 역사는 짧고 다른 분야에 비해 연구범위도 다양하다. 따라서 우리는 한국의 기술혁신연구에서도 전통적인 계량서지학의 법칙들이 적용되는지를 고찰하고자 한다. 한편 전통적인 법칙과 함께 멱함수 법칙의 설명력을 비교한다. 영향력지수와 관련하여, 한국의 기술혁신연구에 기여 정도를 측정하는 의사 영향력지수를 제안한다. 연구자의 생산성을 측정하기 위해 사용되는Lotka's law와 Bradford's law가 적용됨을 확인했으나, Nicholls(1998)와 마찬가지로 Price's Square Root law가 유효하지 않았다. 저널에 대한 인용의 측면에서는Garfield의 법칙 역시 적절하지 않았다. 다만 멱함수 법칙은 저자, 저널, 논문 및 단행본 모두에서 잘 적용됨을 확인하였다. 이전 연구에서 추정된1.5에서3사이의 범주와 유사하게 한국의 기술혁신연구에서도 1.6에서 3.5사이의 수치가 추정된 것이다. 의사 영향력지수(quasi-impact factor)를 본 연구에 적용한 결과, 피인용도가 높은 저널 집단의 한국기술혁신연구에 대한 영향력은 국제적 기술혁신연구에 비하여 그 정도가 약한 것으로 나타났다.