• The Mathematical Education
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• v.55 no.2
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• pp.171-192
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• 2016

As teachers' competency is evaluated based on their teaching performance. pre-service teachers need to have an opportunity to reflect on themselves by systematically analyzing and evaluating their own lesson planning and teaching performance through self-assessment. In this study, we aimed to examine what evaluation criteria for lesson planning and teaching performance pre-service mathematics teachers consider in the process of self-assessment. This study used a mixed-methods research design. To draw the self-evaluation criteria for lesson planning and teaching performance, pre-service self-reported assessments were analyzed using qualitative analyses. In addition, descriptive statistics were used to investigate the pre-service teachers' distribution across the criteria and check the ratio of pre-service mathematics teachers for each element. As a result, it was disclosed that pre-service mathematics teachers considered eight elements in self evaluating their own lesson planning and teaching performance. In addition, we found that pre-service mathematics teachers tended to consider Pedagogical Content Knowledge (PCK) more than Subject-Matter Knowledge (SMK). Moreover, the results of this study provide educational implications for the curriculum in the pre-service teacher's education program.

• East Asian mathematical journal
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• v.33 no.2
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• pp.177-197
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• 2017

The purpose of this study is to investigate and analyze the understandings of elementary pre-service teachers about 'estimation' in the elementary mathematics. Together with this analysis, we identify elementary pre-service teacher's Mathematical Pedagogical Contents Knowledge(MPCK), especially focusing to Subject Matter Knowledge(SMK). In order to this goals, we investigate contents relating to 'estimation' from $1^{st}$ curriculum to 2009 revised curriculum and compare 'rounding up', 'rounding off', 'rounding' in the elementary mathematics textbooks. As results of investigations, 'estimation' has been teaching at the 'Measurement' domain from $3^{rd}$ curriculum, but contexts of measuring weaken from $7^{th}$ curriculum. 'Rounding up(off)' is defined three types in the textbooks from $1^{st}$ to 2009 revised curriculum. And we examine elementary pre-service teachers through the questions on these 'estimation' contents. On the analysis of pre-service teacher's understanding relating MPCK, four themes is summarized as followings; the understanding of '0' in the 'rounding up', the cognitive gap between 'rounding up' and 'rounding off', the difference of percentage of correct answers according to types of question in the 'rounding up', and the difference between the definition of 'rounding up' and the definition of 'rounding'.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1858-1861
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• 2005

Automatic nut sorting machine used to calculate the size of inserted nut and detect the black spot defection is introduced in this paper. Because most of farm products are imported from the underdeveloped countries, domestic farm products have no place to be sold in market. To overcome this critical situation, lowering the productivity cost is strongly demanded to compete with foreign corps. Imaged processed nut sorting algorithm is developed to the automatic nut sorting machine to remove the sorting time which takes lots of man power. This system is composed of mainly two parts, mechanical parts and vision system. The purpose of mechanical part is supplying the nuts automatically to make computer system capture the images of objects. Simplified mechanical system was assembled followed by 3D simulation by Pro/E design for the adaptive cost effects. Several image processing algorithms are designed to detect the spot defects and calculate the size of nuts. Test algorithm shows good results to the designed automatic nut sorting system.

• The Korean Journal of Mycology
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• v.27 no.1 s.88
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• pp.54-62
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• 1999

This paper is the sixth contribution towards taxonomic studies on Cercospora and allied genera, and contains ten species of Korean cercosporoid fungi; viz., Cercospora apii, C. aristolochiae-contortae, C. violae, Neoramularia bidentis, Phaeoramularia weigelicola, Pseudocercospora cantuariensis, P. cydoniae, P. profusa, Pseudocercosporella sublineolata, and Ramularia plantaginis. Morphological characteristics of taxonomic value are described and illustrated for these species to contribute towards a mycological monograph of Korean cercosporoid fungi.

• Journal of the Korean earth science society
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• v.38 no.5
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• pp.367-377
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• 2017

The purpose of this research is to investigate characteristics of science content knowledge and pedagogical content knowledge shown in the primary school science classes. Through analysis of classroom teaching, explore the features and differences between primary and secondary school science PCK. Using open-ended interviews with the teachers and group discussions on a regular basis to analyze and compare classes of five primary school teachers, the relationship between CK and PCK. Regardless of the school level the teacher's PCK and professionalism is required with varying focus and emphasis. The features of the primary school teacher's PCK are as follows: Firstly, elementary teach secondary teach content, teachers value pedagogical knowledge (PK) content knowledge (CK). The primary school PCK requires more of understanding of students and teaching methods that to subject areas. PCK be without content knowledge, and the teacher's PCK is subject-specific In addition to the characteristics of PCK in the primary school science teaching, ways to set up professional exchange or collaboration between primary and secondary teachers, and to provide supplementary in-service training focused on content knowledge for primary school teachers.

• The Korean Journal of Mycology
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• v.26 no.4 s.87
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• pp.437-449
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• 1998

This paper is a fourth contribution towards taxonomic studies on Cercospora and allied genera, and contains ten species of Korean cercosporoid fungi; viz. Cercospora capsici, C. cardaminae, C. nasturtii, Phacellium episphaerium, Pseudocercospora chengtuensis, P. diospyrimorrisianae, Pseudocercosporella capsellae, Ramularia armoraciae, R. lamii var. lamii, and R. pratensis var. pratensis. Morphological characteristics of taxonomic value are described and drawn for these species to contribute towards a mycological monograph of Korean cercosporoid fungi.

• The Korean Journal of Mycology
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• v.26 no.3 s.86
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• pp.327-341
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• 1998

The mycoflora of Korea, especially the cercosporoid taxa, have been poorly studied in the past. For this reason, a systematic revision of these taxa has been initiated, with the eventual aim of producing a monograph of the Korean cercosporoid taxa. The present study circumscribes ten species; viz., Cercospora althaeina, C. arachidicola, C. armoraciae, C. carotae, C. ipomoeae, Mycovellosiella ferruginea, Passalora miurae, Pseudocercospora araliae, P. cannabina and P. vitis. Distinguishing morphological characteristics are described and illustrated for each species.

• School Mathematics
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• v.17 no.2
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• pp.179-202
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• 2015

In this research, I explored how to apply the history of mathematics in teacher education and investigated the applicability of Chosun Sanhak (mathematics of Chosun Dynasty) as the program that enriched the mathematical knowledge for teaching of prospective elementary school teachers. This program included not only mathematical knowledge but also socio-cultural knowledge and connection knowledge. Prospective teachers participated in various mathematical activities such as explaining, reasoning and problem solving in this program. The effects of this program are as follows. Prospective teachers learned the subject matter knowledge(SMK) which was helpful in teaching basic concepts and skills of elementary mathematics. Next, this program produced the pedagogical content knowledge(PCK) to prospective teachers by giving ideas how to teach.

• Korean Journal of Remote Sensing
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• v.28 no.4
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• pp.435-448
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• 2012

Evapotranspiration (ET) including evaporation from a land surface and transpiration from photosynthesis of vegetation is a sensitive hydrological factor with outer circumstances. Though both direct measurements with an evaporation pan and a lysimeter, and empirical methods using eddy covariance technique and the Bowen ratio have been widely used to observe ET accurately, they have a limitation that the observation can stand for the exact site, not for an area. In this study, remote sensing technique is adopted to compensate the limitation of ground observation using the Moderate Resolution Imaging Spectroradiometer (MODIS) multispectral sensor mounted on Terra satellite. We improved to evapotranspiration model based on remote sensing (Mu et al., 2007) and estimated Penman-Monteith evapotranspiration considering regional characteristics of Korea that was using only MODIS product. We validated evapotranspiration of Sulma (SMK)/Cheongmi (CFK) flux tower observation and calculation. The results showed high correlation coefficient as 0.69 and 0.74.

• Communications of Mathematical Education
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• v.30 no.1
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• pp.101-120
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• 2016

The purposes of the study were to analyze pre-service mathematics teachers' MKT and to examine the perceptions of MKT to find implications for the improvement of pre-service mathematics teacher education program in the aspect of teachers' content knowledge. Twenty-six pre-service mathematics teachers participated in the survey to examine the perceptions of MKT and they also finished two MKT tasks which focused on a specific area of middle school geometry. According to the survey results, the participants thought that they have enough knowledge in all categories of MKT except KCT-2 and they appreciated the importance of MKT education in pre-service mathematics teacher education program. However, the participants showed difficulties in MKT task items which required SCK, KCS, KCT, especially, the proportions of those who showed appropriate knowledge on the items required SCK and KCT was less than 50%. These results show disagreement between the perceptions of pre-service mathematics teachers' MKT and practice of MKT.