• Journal of Educational Research in Mathematics
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• v.26 no.3
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• pp.403-420
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• 2016

Some of the critical changes in the revised 2015 Korean Mathematics curriculum were that direct proportion and inverse proportion were moved from elementary school to middle school and that supplementary content related to correlation was included. These decisions were based on comparative studies of international curriculum. Therefore in this study, we selected countries for comparison; United States, England, France, Finland, Australia, Japan, Singapore, China and Taiwan. We looked into the timing and scope for direct/inverse proportion and correlation in curricula of these countries. Along with this, we established four criteria; vertical sequence, horizontal sequence, external connection, and internal connection for an analysis framework. Then we compared and analysed the direct/inverse proportion and correlation in each curriculum. As a result, in most of these curricula, the direct/inverse proportions are introduced at middle school or are introduced at elementary school and then developed further at middle school. Most of curriculums on direct/inverse proportion and correlation match the four criteria. Correlation is introduced in high school mathematics in all counties except Finland and it is dealt in diverse context introducing related concepts, for example, correlation coefficient, regression straight line, and least square. We suggested that it is necessary to refer these international trends for the next revision of curriculum.

• 프린팅코리아
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• s.23
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• pp.116-117
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• 2004

• KOREAN POULTRY JOURNAL
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• v.33 no.11 s.385
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• pp.63-65
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• 2001

• Communications of Mathematical Education
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• v.24 no.2
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• pp.345-363
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• 2010

The purpose of this study is to investigate and analyze informal knowledge of students who do not learn the conception of proportion and to identify how the informal knowledge can be used for teaching the conception of proportion in order to present an effective method of teaching the conception. For doing this, proportion was classified into direct and inverse proportion, and 'What are the informal knowledge of students?' were researched. The subjects of this study were 117 sixth-graders who did not have prior learning on direct and inverse proportion. A total eleven problems including seven for direct proportion and four for inverse proportion, all of them related to daily life. The result are as follows; Even though students didn't learn about proportion, they solve the problems of proportion using informal knowledge such as multiplicative reasoning, proportion reasoning, single-unit strategy etc. This result implies mathematics education emphasizes student's informal knowledge for improving their mathematical ability.

• 공원문화
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• s.39.40
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• pp.58-59
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• 1988

국.도.군립 등 자연공원의 보호와 이용에 대한 도하각신문 기사의 초점은 모든 개발도상국들이 겪듯이 보호보다 이용.개발쪽에 시각을 높혀 지역민의 경제발전과 연계하려는 경향이 짙다. 더욱이 보호의식의 희박으로 환경오염의 심각성은 폭주하는 이용객과 정비례하는 적신호를 울리고 있어 보호의식의 선양이 초급하다. 참고로 최근 각신문(전문지 포함)에 비친 국립공원 등 자연공원에 관한 기사의 제목만이라도 엮어 매스콤의 초점을 살펴 연구자료로 삼고저 한다.

• The Korean Journal of Ecology
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• v.23 no.1
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• pp.39-43
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• 2000

Carbon dioxide (CO₂) and ozone (O₃) fluxes were measured over Glycine max canopy using the bowen ratio energy balance method at Fuchu - 20 km west of Tokyo, in late July and late September 1996. The CO₂, and O₃, fluxes were influenced by variation in leaf area index (LAI) during the measuring period. When LAI was more than 3.0, the CO₂ flux was found to be positively correlated with photosynthetically active radiation (PAR). The O₃, flux was always positive with an average deposition velocity for this case of about 0.5 mol m/sup -2/s/sup -1/. A positive correlation existed between the deposition velocity of O₃ and CO₂ during the period of LAI＞2.0.

• Applied Chemistry for Engineering
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• v.4 no.2
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• pp.300-307
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• 1993

The phase-transfer polymerization of methyl methacrylate with tricaprylmethylammonium chloride-$Na_2S_2O_4-CCl_4$ initiator system was investigated in an aqueous-organic two-phase system. The observed rates of polymerization were compared with those obtained from the polymerization mechanism proposed with a cyclic phase-transfer initiation step. The rate of polymerization was found to be proportional to the concentration of $Q^+$ and square root of ${S_2O_4}^{-2}$ in the aqueous solution and the feed quantity of $CCl_4$ and MMA.

• School Mathematics
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• v.16 no.1
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• pp.39-56
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• 2014

This study analysed 8 gifted students' behavior of using calculator in the 5th grade based on qualitative data of direct proportion class with the utilization of the calculator. Pretesting with questionnaire had been made to verify students' developmental stages of proportional reasoning, and the stage was categorized according to Baxter & Junker (2001). The learning contents were made of worksheet, and the researcher held the class for 60 minutes. For analysing data, record of class was gathered to make a transcript and analysed it with Guin & Trouche' behavior of using calculator type. According to the result, each type of the behavior affected students' development of proportional reasoning differently.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.162-167
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• 2015

매년 여름철 피서지 1순위로 손꼽히는 해수욕장은 해양레포츠의 발달과 관광사업의 촉진으로 수많은 관광객들이 방문하고 있다. 하지만 우리나라 대부분의 해수욕장에서는 건전한 해수욕을 위한 수질안전지표 설정이 매우 미흡한 편이며 오염수준 또한 심각하다. 이에 강원도 강릉시 경포해수욕장을 대상지역으로 2012년 7월 17일부터 9월 4일까지 매주 화요일 오전에 채취한 시료로부터 병원성 수질지표인 장구균과 대장균, 총대장균군의 오염도를 분석하였다. 시료는 경포해수욕장 오리바위 배후부터 연안방향을 따라 200m 간격으로 3지점과 이안방향을 따라 백사장(dry beach), 포말대(swash zone), 유영층(swimming zone)의 3지점에서 총 9개를 채취하였다. 기온, 강우, 장소 등의 해안 환경 변화에 따른 병원균 증식 유리조건 및 인자들간의 상관성을 분석한 결과 백사장에서는 총대장균군, 포말대에서는 장구균, 유영층에서는 대장균의 농도가 가장 높았다. 또한 주간 누적 강우량과 평균 기온에 따라 시료채취 지점마다의 상관성에서는 백사장은 강우량과 정비례, 기온과는 반비례, 포말대와 유영층은 강우량과 반비례, 기온과는 정비례의 관계를 보였다. 백사장과 해수층인 포말대, 백사장과 유영층 각각은 반비례 관계를 보였지만 미비한 수준이었으며 포말대와 유영층간의 상관성은 약 90%의 매우 높은 수치를 띄었다. 본 연구는 건전한 수계 레크레이션 문화의 수질 안전지표 설정을 위해 해수욕장의 대표 관광명소 중 하나인 경포해수욕장을 대상으로 병원성 수질 지표들의 증식 유리 조건 및 확산특성 예측에 목적이 있다. 나아가 본 과정은 해변을 찾는 관광객들의 수질 안전 정보 제공 및 체계적인 가이드라인 제시로도 가치 있을 것으로 기대된다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.3
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• pp.303-309
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• 1989

Present study was conducted to reveal the effects of the herbicides, Lasso and Devrinol, on the soybean growth and the nodulation in field condition. Emergence rate was reduced positively in proportion to increase in the concentration of herbicides regardless of the herbicidal difference and it was significantly reduced even in the recommended concentration as compared to untreated plot, showing marked abnormal symptom on seedlings. Plant height, fresh weight of the plant, number of internodes, branches, pods, seeds per plant and 100-seed weight were reduced with increase in the concentration of herbicides and were highly significant in difference between the untreated plot and double concentration plot, eventhough most were nonsignificant in difference from the recommended concentration. Nodulation was significantly decreased with increase in the concentration of herbicides. The reduction was remarkably different with soybean varieties and consistently appeared from three weeks to six weeks after sawing. Significant correlation was realized between the reduction of nodulation and the agronomic characters of soybean and it was considered that the reduction of nodulation by misapplication of the herbicides might be a causal factor for decrease in soybean yield.