• 제목/요약/키워드: Periodic table

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중학교 과학2 교과서에 서술된 원소, 주기율표, 원자 내용이 요구하는 인지 수준 분석(제I보) (Analysis of the Level of Cognitive Demands about Concepts of Elements, the Periodic Table, and Atoms on Science 2 Textbooks in Junior High School (I))

  • 강순희;방담이;김선정
    • 대한화학회지
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    • 제56권4호
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    • pp.518-529
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    • 2012
  • 이 연구에서는 중학교 '과학2' 교과서에 서술되어 있는 '원소', '주기율표', '원자'에 대한 내용이 요구하는 인지 요구도를 분석하였다. 우리나라는 2007년 개정 교육과정에 의하여 처음으로 주기율표 및 그와 관련 내용들을 중학교에서 다루게 되어있다. 분석에 활용한 6종 과학 교과서에 서술된 내용이 어떠한 인지 수준을 요구하는 지를 알아내는 분석틀은 영국에서 개발된 CAT(Curriculum Analysis Taxonomy)의 3종류 분석틀을 사용하였다. 이 3종류 분석틀에 의하여 분석한 '과학2' 교과서에 서술된 내용이 요구하는 인지 수준들은 다음과 같았다. '원소'에 대한 교과서 서술이 더 이상 간단한 물질로 분리될 수 없는 순물질임을 이해하는 내용으로 후기 형식적 조작 수준이었다. 그러나 '원소'는 한 가지 종류의 원자만으로 이루어진 물질이라고 서술된 초기 형식적 조작 수준도 있었다. '주기율표'에 대한 교과서 서술이 다양한 종류의 원소들을 원소 기호를 이용하여 특정 기준에 따라 몇 가지 그룹으로 분류될 수 있음을 이해해야 하고, 실체를 범주화하는데 있어서 여러 기준으로 분류해야 하는 내용으로 후기 구체적 조작 수준이었다. '주기율표'를 여러 족들의 집함임을 알고 이원 분류표로 이해해야 하는 내용으로 초기 형식적 조작수준이었다. '원자' 구조와 연결 짓는 복합적 분류 체계로 주기율표를 표현하는 후기 형식적 수준도 있었다. '원자'에 대한 교과서 서술이 원자가 구조를 가진다는 것 그리고 원자가 같은 종류도 있고 다른 종류도 있다는 서술은 초기 형식적 수준이었다.

증발계 증발량의 시계예 및 통계적 특성 분석 (Analysis of the Statistical and Time-Series Characteristics for Pan Evaporation)

  • 구자웅
    • 한국농공학회지
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    • 제19권3호
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    • pp.4472-4482
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    • 1977
  • In order to estimate furture consumtive use, some statistical characteristics of 22-year pan evaporation data at four selected stations were calculated in this study. Districal distribution, trend analysis and time-series, statistical and periodic analysis for annual, monethly and ten-day values were performed in the statistical analysis. The stations are Seoul, Taeku, Jeonju and Mokpo for monthly data, and Suweon data are compared to the reported Penman values. The results are as followed: 1. Annual evaporation ranged to 990-1,375mm varying with the locations of the stations. The Districal distribution of evaporation in the Republic is shown in Fig. 1. 2. The trend analysis for annual evaporation resulted in detail in Table 2 and Fig. 2, through simple moving average methods. The results show relatively short-period data of about 10 years would be acceptable for field use. 3. The means and dispersions of monthly evaporation at four stations are detailed in Table 3. 4. The monthly evaporation approached to the trend of normal distribution Fig. 3 showed the examples of normal distribution for each typical monthly data. 5. The correlograms detailed in Fig. 4, shows the time-series characteristics of monthly evaporation, whose periodic term should be twelve months. 6. The periodic analysis for monthly evapolation results in Table 4. Fig. 5 shows the comparison of estimated values to actual and the trend approaches Shuster's periodic trend. 7. A periodic description of days after March 1 for irrigation periods was developed to predict ten-day evaporation in Fig. 6. The ten-day etraporation is different in the distribution form and occurence period of maximum values from the reported Penman's man's evapotranspiration.

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양면지지형 유정압테이블 운동정밀도의 유한요소 해석 (Finite Element Analysis on the Motion Accuracy of Double-sides Hydrostatic Table)

  • 박천홍;정재훈;이후상;이찬홍
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2000년도 추계학술대회 논문집
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    • pp.188-192
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    • 2000
  • An analysjs model for calculation the motion accuarcy of double sides hydrostatic table is proposed in thn paper. For the analysis of motion accuracy, profiles of each rails are assumed as periodic function, and represented using Fourier coefficients. Variahon of bearing clearance is represented as the vanation of linear, angular displacement of table and profiles of rails. Motion accuracy is calculated in the basis of finite element analysis on the pressure dutributmn of table. In order to improve calculating time in the analysis of motion accuracy, The proposed modeling method converts double sides table to single side table equivalently Results by the proposed method 1s compared with directly caculated results mdyhcally, and also compared wlth experimental results. From the theoretical and experimental analysis, it is confirmed that the proposed modeling mothod is very effective to analyze the motion accuracy of dauble sides hydrostatic table.

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New Construction Method for Quaternary Aperiodic, Periodic, and Z-Complementary Sequence Sets

  • Zeng, Fanxin;Zeng, Xiaoping;Zhang, Zhenyu;Zeng, Xiangyong;Xuan, Guixin;Xiao, Lingna
    • Journal of Communications and Networks
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    • 제14권3호
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    • pp.230-236
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    • 2012
  • Based on the known binary sequence sets and Gray mapping, a new method for constructing quaternary sequence sets is presented and the resulting sequence sets' properties are investigated. As three direct applications of the proposed method, when we choose the binary aperiodic, periodic, and Z-complementary sequence sets as the known binary sequence sets, the resultant quaternary sequence sets are the quaternary aperiodic, periodic, and Z-complementary sequence sets, respectively. In comparison with themethod proposed by Jang et al., the new method can cope with either both the aperiodic and periodic cases or both even and odd lengths of sub-sequences, whereas the former is only fit for the periodic case with even length of sub-sequences. As a consequence, by both our and Jang et al.'s methods, an arbitrary binary aperiodic, periodic, or Z-complementary sequence set can be transformed into a quaternary one no matter its length of sub-sequences is odd or even. Finally, a table on the existing quaternary periodic complementary sequence sets is given as well.

16-QAM Periodic Complementary Sequence Mates Based on Interleaving Technique and Quadriphase Periodic Complementary Sequence Mates

  • Zeng, Fanxin;Zeng, Xiaoping;Xiao, Lingna;Zhang, Zhenyu;Xuan, Guixin
    • Journal of Communications and Networks
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    • 제15권6호
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    • pp.581-588
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    • 2013
  • Based on an interleaving technique and quadriphase periodic complementary sequence (CS) mates, this paper presents a method for constructing a family of 16-quadrature amplitude modulation (QAM) periodic CS mates. The resulting mates arise from the conversion of quadriphase periodic CS mates, and the period of the former is twice as long as that of the latter. In addition, based on the existing binary periodic CS mates, a table on the existence of the proposed 16-QAM periodic CS mates is given. Furthermore, the proposed method can also transform a mutually orthogonal (MO) quadriphase CS set into an MO 16-QAM CS set. Finally, three examples are given to demonstrate the validity of the proposed method.

Ad-hoc 망에서 유니캐스트 성능 향상을 위한 개선된 ODMRP (An enhanced unicast of ODMRP scheme for Ad-hoc Networks)

  • 백경호;박재우;이제원;이균하
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 I
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    • pp.157-160
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    • 2003
  • ODMRP is protocol that support multicast and unicast in Ad-hoc network. When some one node must transmit data by unicast way in this ODMRP, must pass through periodic flooding process to find a path and overhead happens thereby. Our scheme stores the found path into the table in a unicast mode and, when the node sends data, it refers to the DR FG table so that reduces the traffic caused by control packets(JOIN QUERY, JOIN REPLY) of a receiver node, while source/destination nodes flood periodic control packets to look for a path in ODMRP. We present that our scheme is much more improved on the time of looking for a path than existing ODMRP methods by means of the simulation.

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Automated inventory and material science scoping calculations under fission and fusion conditions

  • Gilbert, Mark R.;Fleming, Michael;Sublet, Jean-Christophe
    • Nuclear Engineering and Technology
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    • 제49권6호
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    • pp.1346-1353
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    • 2017
  • The FISPACT-II inventory simulation platform is a modern computational tool with advanced and unique capabilities. It is sufficiently flexible and efficient to make it an ideal basis around which to perform extensive simulation studies to scope a variety of responses of many materials (elements) to several different neutron irradiation scenarios. This paper briefly presents the typical outputs from these scoping studies, which have been used to compile a suite of nuclear physics materials handbooks, providing a useful and vital resource for material selection and design studies. Several different global responses are extracted from these reports, allowing for comparisons between materials and between different irradiation conditions. A new graphical output format has been developed for the FISPACT-II platform to display these "global summaries"; results for different elements are shown in a periodic table layout, allowing side-by-side comparisons. Several examples of such plots are presented and discussed.

FEM을 이용한 유정압테이블의 운동정밀도 해석 (2. 양면지지형 테이블의 해석 및 실험적 검증) (Finite Element Analysis on the Motion Accuracy of Hydrostatic Table ($2^{nd}$. Analysis and Experimental Verification on Double Sides Table))

  • 박천홍;이후상;김태형;김민기
    • 한국정밀공학회지
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    • 제19권1호
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    • pp.65-70
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    • 2002
  • An analysis method for calculating motion accuarcy of double sides hydrostatic table is proposed in this paper. In this method, profiles of each rails are assumed as periodic function, therefore it is represented as the sum of spacial frequencies. Bearing clearance at any position rail is depended on the variation of linear, angular motion error of table and the form errors of both sides of a rail. Finite element method is applied to calculate pressure distributions in bearing clearance. In order to simplify the analyzing process, double sides table model is converted into equivalent single side table model. Results calculated by the proposed modeling method agree well with the results directly caculated by double sides modeling method, and also agree well with experimental results. From the theoretical and experimental analysis, it is verified that the proposed analysis method is very effective to analyze the motion accuracy of double sides hydrostatic table.

한국(韓國)의 도시광산(都市鑛山)(사용후제품) 자원(資源)과 금속재자원화(金屬再資源化) (Urban Mine Resources and Metal Recycling in Korea)

  • 오재현;김준수;문석민;민지원
    • 자원리싸이클링
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    • 제20권6호
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    • pp.3-18
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    • 2011
  • 우리나라의 도시광산 재자원화실태와 전망을 파악하기 위하여 금속소비량을 산출하였다. 년간 금속소비량으로부터 금속 축적량을 추정할 수 있고, 도시광산자원을 전망할 수 있다. 금속소비량을 산출함에 있어 다양한 자료 즉 비철협회, 철강협회, 관세청 HS 코드, 연구용역 보고서, 학술회의자료 및 생산회사 탐문자료 등을 인용하였다. 도시광산개발의 요건(key point)을 설명하기 위하여 T.E.Graedel에 의해서 작성된 표(Principle Uses and Recycling Potential of Metals in the Periodic Table)를 인용하였다.

Non-periodic Subway Scheduling that Minimizes Operational Cost and Passenger Waiting Time

  • Hong, YunWoo;Chung, Yerim;Min, YunHong
    • 한국컴퓨터정보학회논문지
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    • 제23권8호
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    • pp.133-142
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    • 2018
  • Subway metro scheduling is one of the most important problems impacting passenger convenience today. To operate efficiently, the Seoul metro uses regular, periodic schedules for all lanes, both north and southbound. However, many past studies suggest that non-periodic scheduling would better optimize costs. Since the Seoul metro is continuously facing a deficit, adopting a non-periodic schedule may be necessary. Two objectives are presented; the first, to minimize the average passengers' waiting time, and the second, to minimize total costs, the sum of the passenger waiting time, and the operational costs. In this paper, we use passenger smart card data and a precise estimation of transfer times. To find the optimal time-table, a genetic algorithm is used to find the best solution for both objectives. Using Python 3.5 for the analysis, for the first objective, we are able to reduce the average waiting time, even when there are fewer trains. For the second objective, we are able to save about 4.5 thousand USD with six fewer trains.