• Journal of Educational Research in Mathematics
• /
• v.18 no.2
• /
• pp.157-177
• /
• 2008

This paper provides a description of the process in development of textbook unit on measuring length for second grade in elementary school according to action research methodology. The teaching unit development has been done based on the new national mathematics curriculum released in 2006. Mathematical communication and positive attitude toward mathematics are highly emphasized in the new curriculum. These new foci have been analysed through literature review and interviews with two incumbent teachers to be respected in the unit in an appropriate way. Three stages of development with different ways of organizing contents and different problem contexts were reported in the paper.

• Journal of Elementary Mathematics Education in Korea
• /
• v.19 no.3
• /
• pp.267-287
• /
• 2015

In this paper, based on the results of analysis on types and strategies of estimation in measurement in the textbooks according to 2009 revised elementary mathematics curriculum, the following four implications are suggested for curriculum development and textbook development for a later date. First, it is necessary to reconcile curriculum and textbooks in contents for estimation in measurement. In 2009 revised elementary mathematics curriculum, only estimation in length, estimation in capacity, estimation in weight, estimation in angular measure are presented. However, estimation in time and estimation in area are presented in textbooks. Second, it is necessary to introduce various strategies for estimation in measurement. In teacher's manual, three strategies like using referent, chunking, unitizing are illustrated. But in textbooks, such strategies are not illustrated properly. Third, the meaning of the 'estimate' need to be clarified. In textbooks, 'estimate' are used also in other contexts. Fourth, it is necessary to clarify whether or not to deal with estimation in time, estimation in area, and estimation in volume in the school curriculum. In 2009 revised elementary mathematics curriculum, estimation in time, estimation in area, and estimation in volume are not mentioned explicitly.

• Journal of the Korean School Mathematics Society
• /
• v.21 no.1
• /
• pp.19-37
• /
• 2018

In this study, the actual state of teaching seven extensive quantities (time, length, capacity, weight, area, angle measure, volume) of measurement domain are analyzed comparatively between the 2015 revised elementary school mathematics curriculum in Korea and the 2017 revised elementary school mathematics curriculum in Japan in terms of comparison in measurement, direct measurement, indirect measurement, and estimation in measurement. From the results of this comparative analysis, some implications for discussion on the development of the next elementary school mathematics textbook and the next elementary mathematics curriculum can be suggested. First, it is necessary to discuss on clarifying the range of handling of comparison, direct measurement, indirect measurement, estimation of seven extensive quantities respectively. Second, it is necessary to discuss on doing direct comparison when intuitive comparison is difficult. Third, it is necessary to discuss on reconsidering indirect comparison of weights. Fourth, it is necessary to discuss on reconsidering measurement using arbitrary units in case of angular measures. Fifth, it is necessary to discuss on dealing with estimating the area of $1cm^2$ and $1m^2$ and the volume of $1cm^3$ and $1m^3$ for the purpose to make rough guesses their size respectively.

• Education of Primary School Mathematics
• /
• v.10 no.2
• /
• pp.77-110
• /
• 2007

This study attempted to investigate how to students show high-level mathematical thinking in math classes. This paper describes how to setup the task for lead to a high - level of thinking out students and what efforts are required while a teacher tried to maintaining students's high-level cognition during the tasks implemented. The researcher as teacher analyzed the tasks of length measurement unit in 2-Ga elementary math textbooks, modified and created math tasks demanded students' high-level cognition, made instruction plans, and implemented those tasks maintaining the levels of cognitive demand of tasks. After that, the researcher reflected and analyzed the levels of cognitive demand of tasks of instruction and factors that cause to change intended high-level cognitive demand. After reflection, second roof of action research was conducted to 2-Na length measurement unit. This paper includes those results and reflections of practitioner.

• Animal Systematics, Evolution and Diversity
• /
• v.13 no.1
• /
• pp.1-8
• /
• 1997

The first zoeae of Hyastenus elongatus (Ortmann, 1893) were obtained in thelaboratory from hatching. They are described, illustrated in detail and compared with the previously described zoeae of the subfamily pisinae. The zoeae of H. elongatus are similar to, but may be distinguished from those of Hyastenus diacnathus (De Haan, 1839), by the number of setae on the postero-lateral carapace margin and mouthpart appendages, and the length of a dorsal carapace spine. In the mouthpart appendages, the difference in the number of setae on an endopod of the maillule between H. eleongatus and H. diacanthus is doubtful, and it should be necessary ot make a detailed re-description of H. diacanthus.

• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.55-60
• /
• 2003

Case that long-fiber reinforced polymeric composites of fiber orientation situation of a direction state is J=1 that is direction of tensile strength of another state appeared highest. And theoretical tensile strength value of long-fiber reinforced polymeric composites board of fiber orientation situation of a direction state appeared similarly with tensile strength value that long-fiber reinforced polymeric composites board of fiber orientation situation of a direction state. Also, than case that efficiency of fiber orientation situation of long-fiber reinforced polymeric composites is J=1 in it is J=0.1 of fiber orientation situation effect of long-fiber reinforced polymeric composites about 60% high appear.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2003.04a
• /
• pp.202-205
• /
• 2003

Investigated whether fiber orientation situation of fiber reinforcement macromolecule composition board and the fiber inclusion rate are perpendicular and horizontal direction tensile strength and some correlation. Fiber orientation situation of tensile strength of 0 direction of composition board increased changelessly by aeolotropy in isotropy. Tensile strength of 90 direction that is isotropy and tensile strength of 0 direction that is aeolotropy agreed almost. Get into aeolotropy, the reinforcement rate of fiber decreased. When load interacts for width direction of reinforcement.

• Proceedings of the KSME Conference
• /
• 2004.04a
• /
• pp.186-191
• /
• 2004

we can say that the increasing range of the value of GMT Sheet's tensile strength in the direction of fiber orientation is getting wider as the fiber content increases. It shows that the value of GMT Sheet's tensile strength in the direction of fiber orientation 90 is similar with the value of pp's intensity when fiber orientation function is J= 0.7, regardless of the fiber content. Tensile strength of GMT Sheet is affected by the fiber orientation distribution more than by the fiber content.

• Animal Systematics, Evolution and Diversity
• /
• v.19 no.2
• /
• pp.227-235
• /
• 2003

The euplotid hypotrich collected from a puddle, Jeju-do in 2002 and cultured in the laboratory was identified as Euplotes muscorum Dragesco, 1970. The species is reported for the first time from Korea. The description was based on the observation of living specimens, protargol impregnation and biometrical analysis. This species is characterized by following diagnosis: 63-78 ${\mu}m$ in length, 40-52 ${\mu}m$ in width in vivo, 9 frontoventral cirri, 5 transverse cirri,4 caudal cirri, 1 micro- and macronucleus, adoral zone of membranelles with 32-36 adoral membranelles covering approximately 2/3 of body length, 8 dorsal kineties, mid-dorsal kinety with 20-24 cilia 3nd dargyrome complex type. This species with 9 frontoventral cirrotype is very similar to E. muscicola Kahl, 1932. The differences between these two species are: E. muscorum has 8 dorsal kineties and complex dargyrome type, while E. muscicola 9 dorsal kineties and multiple dargyrome type.

• Proceedings of the Korean Society for Language and Information Conference
• /
• 2001.06a
• /
• pp.95-96
• /
• 2001

문장에서 술어를 수식하는 대표적인 표현은 부사어이다. 부사어는 일반적으로 문장 구성에서 핵심적 역할을 하지 않는 첨가어(adjuncts)이기 때문에 핵심적인 역할을 하는 보충어(complements)에 비해 상대적으로 연구가 덜 이루어진 분야이다. 그렇지만 부사어는 피수식어의 의미를 구체화/한정하는 기능을 하기 때문에 정확한 의사소통을 위해서는 반드시 필요한 요소이며 어순, 호응(concord)등의 통사적 현상과도 밀접한 관련이 있다. 이 연구의 일차적 목적은 이러한 부사어를 통사적, 의미적 기준에 의해 정확하게 분류하고 그들의 분포제약을 밝히는 것이다. 그 다음으로, 부사어와 관련된 통사 현상으로, 부사어와 피수식어의 공 기(co-occurrence)관계 및 부사어와 술어 어미의 호응 관계에 대한 분석을 제공하려고 한다. 부사어는 통사적인 기준과 의미적인 기준으로 분류할 수 있다 (손남익 1995, 김경훈 1996, 임유종 1998). 통사적 기준으로는 단어나 구를 수식하는 성분부사와 문장을 수식하는 문장 부사로 나누는 방법과 위치에 대한 제약이 있느냐 없느냐에 따라 제약부사와 자유부사로 나 누는 방법이 있다. 이 두 통사론적 기준에 의해 분류되는 부사들은 서로 어떤 상관관계를 보이고 있는지 살펴 볼 것이다. 일반적으로 문장부사는 문두에 놓여야 한다는 위치적 제 약 이 있기 때문에 제약부사로 분류된다. 의미적 기준으로 부사어를 분류할 수도 있는데, 시간/ 공간 부사어, 양태/정도 부사어 등으로 나눌 수 있다. 의미적 기준에 의해 분류된 부사어는 통사적 기준에 의해 분류된 것들과는 어떤 상호 관련성을 맺고 있는지 살펴 볼 것이다. 일 반적으로 시간부사와 장소부사는 자유부사에 속하며 양태부사와 정도부사는 제약부사에 속 한다. 부사어와 피수식 요소와의 통사적 공기 관계 및 의미적 관계 그리고 그와 관련된 문 법 현상도 연구의 대상이 된다. 예를 들어, 자유로운 어순을 가진 부사들이지만 “＊순이는 빨리 과연 달린다”에서 볼 수 있는 종류의 분포적 특성을 알아 볼것이다 (심재기 1982, 송 철의 1989). 또한 “길이/＊길게 빛나다”와 “＊길이/길게 드리워졌다”와 같은 대조에서 나타나는 통사, 의미적 기능의 상관 관계 및 제약들의 상호 작용도 살펴 볼 것이다.