• Journal of Educational Research in Mathematics
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• v.18 no.3
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• pp.391-405
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• 2008

There are some studies on tangram a kind of jigsaw(silhouette or dissection) puzzle. And Korean national curriculums mention about tangram. But the past studies and the textbooks are not so related to curriculums. So this study is focused on some problems and limitations of tangram activities related to curriculum. This study gives some educational suggestions using tangram: (1) alternate drawing of tangram (2) making mathematical figures instead of shapes (3) proper activities related to the national curriculum (especially, polygons and angles) and mathematical thinking (4) examples of exploring mathematical figures and angles coming in and out of national curriculum In addition to, this study suggests some mathematical activities of using similar tangrams (especially sphinx puzzle).

• Animal Systematics, Evolution and Diversity
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• v.27 no.2
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• pp.164-166
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• 2011

We report a larentiine species, Collix stellata Warren, for the first time from Korea. Two males and one female were collected from Jeju-do Island, South Korea. Collix stellata is similar to Collix ghosa Walker in external appearances, but can be distinguished by the relatively larger discal dot on forewing and the relatively slender valva with distally projected margin of male genitalia. Diagnosis and description of the species are given with the figures of the genitalia.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.6
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• pp.1001-1007
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• 2002

To improve the performance of the PZT thin flms, each PZT and PT layer was alternately deposited on a Pt/Ti/Si$_3$N$_4$/SiO$_2$/Si substrate by a modified sol-gel solid precursor technique. For comparison, PZT thin films were also prepared with an identical method under the same conditions. XRD measurement revealed that the diffraction pattern of the multilayer film was due to the superimposition of the PZT and PT patterns. At 1㎑, a dielectric constant of 389 and 558, a dielectric loss of 1.2% and 1.1% were obtained for the PZT/PT and PZT thin films, respectively. If we consider the PT dielectric constant to be 260, it is clear that the dielectric constant of alternately deposited PZT/PT thin films was well adjusted. The PZT/PT thin film showed a low dielectric constant and a similar dielectric loss compared with those of the PZT film. The figures of merit on detectivity for the PZT/PT and PZT thin films were 20.3$\times$10$\^$-6/㎩$\^$-$\sfrac{1}{2}$/, and 18.7$\times$10$\^$-6/㎩$\^$-$\sfrac{1}{2}$/, and the figures of merit on voltage response were 0.038㎡/C and 0.028 ㎡/C, respectively. The high figures of merit for the PZT/PT film were ascribed to its relatively low dielectric constant when compared to the PZT thin films.

• Communications of Mathematical Education
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• v.30 no.4
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• pp.453-468
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• 2016

This study is a result of experiment to recognize geometric and spacial conceptions for early childhood. This researcher had built up Mandala figures which was an intermediary between consciousness and unconsciousness, and then have studied about early childhood's geometric and spatial concepts by using Mandala figures. In this paper, authors have studied fractal art activities of early childhood as a follow-up study, since the structure of fractal art is similar to Mandala. As a result, three years old young children have significant correlation in four areas(figure perception, visual discrimination, position-in space perception and visual memory), but five years old young children have significant in three areas(figure perception, position-in space perception and visual memory). For five years old group, there is some difference between boys and girls, also they had described for their art activities like real models.

• Journal of the Korean Ceramic Society
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• v.37 no.4
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• pp.320-326
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• 2000

Development of texture in SiC materials by hot-pressing and subsequent annealing was studied. Crystallographic texture type was characterized by measuring X-ray pole figures on the perpendicular plane to the hot-pressing direction. Observed all pole figures were nearly axially symmetric (fiber texture). In case of ${\beta}$-SiC materials, the pole density of basal plane (0004) increased as annealing time increased, in contrast, other planes (hkil) of ${\beta}$-SiC materials and all planes of ${\alpha}$-SiC materials nearly remained unchanged. In the case of ${\beta}$-SiC materials, therefore, a weak texture of (0001) plane at the normal direction took place in the 8h annealed samples, resulting from grian growth. The fracture toughness values of ${\alpha}$-SiC materials measured in both planes parallel and perpendicular to the hot-pressing direction were very similar. However, the fracture toughness of ${\beta}$-SiC materials measured parallel to the hot-pressing direction were higher than that measured perpendicular to the hot-pressing derection, relatively, because of the texture and the microstructure anisotropy.

• Journal of the Korean Society of Costume
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• v.44
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• pp.57-75
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• 1999

The purpose of this study is to infer the shape and change as auspicious symbolic meaning and figures of a peony pattern. For this study. I analyzed the example of a peony pattern, which is traditional Chinese pattern appeared on a ceramic and textile. The results of this study are as following. First, a peony has particular title, such as 'the king of flowers' and 'the most beautiful woman in country and the smell in heaven' originated in a verse of a poet at Dang's Dynasty. It is reputed to be the best of all flowers, representing beauty, and a beauty. Second, the basic meaning of a peony pattern used as auspicious pattern is prosperity and it has various meanings of it's similar kind through several auspicious objects and combination. Also, it was used for the purpose of adequating the desire of man's blessing mentality. Third, four kinds of characteristics of a peony pattern are as following. 1) A peony pattern has similar shape with 'Bosanghwamoon', which was used as a pattern at formerly period of peony flowers. It was used as realistic shape gave vividness to the characteristic of peony on the shape of 'Bosanghwamoon'. 2) 8-petaled, unique leaves and veins were described in detail by vivid sketching shape of real peony flower. 3) Laying stress on the characteristics of peony flower, which is large and magnificent, several folds petals were described abundantly by exaggerated shape or a shape of big honeycomb. And unique leaves were described realistically on these. 4) It was also expressed peculiar characteristic of peony flower composed of several pieces by weakened design shape.

• Journal of the Korea Fashion and Costume Design Association
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• v.9 no.2
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• pp.93-101
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• 2007

The purpose of the study was to offer basic documents to the textile fashion industry by investigating changes of figures followed by various factors as each other social and cultural environment regardless of the same race. The study conducted a questionnaire survey of Korean women and Korean women in Japan to twenties, forties and sixties. The study enforced measurement from February, 2006 to March, 2006 and from July, 2006 to August, 2006 with R. Martin's Measurement Method of Anthropometry in total 49 measurement items. Also, the study treated statistics of the documents with SPSS WIN 10.0 program. As the result which studied comparison of figures with basic statistics, t-test and more, the study got the following conclusion. Most of Korean women and Korean women residing in Japan have big individual differences in obesity, especially width, thickness, and girth of waist showed the largest variation proving considerable individual difference in waist. In a body measurement comparison, twenties, forties, and sixties of Korean women residing in Japan are higher in heights compare to Korean women, while Korean women have wider and thicker waists than Korean women residing in Japan. In a body difference comparison, categories that showed significant differences are 40's>20's>60's in order and twenties and sixties showed only small difference. In conclusion, Korean women have longer, wider, thicker and smaller waist than Korean woman residing in Japan. When divided by age groups, forties and sixties Korean women are longer in waist, shorter in heights, fatter in weights. Twenties have long waist similar to forties and sixties, but had no significant difference in heights and weights.

• Journal of Plant Biology
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• v.3 no.2
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• pp.29-34
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• 1960

From the view point of phytopathological anatomy, the author has tried to study the effect of the shoot cluster disease virus on the internal structure of vascular tissues of chinese date tree (Ziziphus jujuba var. inermis Rehd.) comparing healthy checks and diseased plants. The materials were collected at the several sites, Kumgock-Ri, Masuc-Ri, Kyungi-Do, and near the campus of Korea University and around the area of Chongam-Dong, Seoul City, from August 15th to September 5th 1959. The leaf materials of healthy and diseased plants are fixed and aspirated in two kinds of killing solutions, formalin-acetic acid alcohol solution and Craf III solution. Sections were cut at 5-10$\mu$ thickness and stained with the double staining reagents of safranin and fast green. In this experiment the author has observed that there are marked structural changes in the infected plants in contrast of healthy checks. As figures 3-7 show that the following characteric changes have taken place on infected plants: 1) the arrangement of irregularly developed sieve elements in phloem, 2) the degeneration of phloem elements, 3) the irregular arrangement of epidermis in mid-vein, 4) more necrosis is observed among the parenchymatous cells, 5) abundant accumulatin of starch grains in parenchymatous cells, . In contrast to the above irregularities caused by the virus disease, the healthy checks appear normal structures as shown in figures 1 and 2. In adding to the all features noted above, the author could also observe an interesting feature that the xylem elements in mid-vein vascular bundle tissues are considerably disorganized to show the unspecialized vessel elements, the irregularly arranged xylem elements. However, this kind of irregularities which occur in xylem under the virus infection has not been reported previously. The features noted on the internal structure of vascular bundle under the condition of infection by the shoot cluster disease on chinese date trees appear to be more or less closely similar to the symptoms of the bunchy-top of banana and the yellow dwarf disease of barley in respect to the fact that whether phloem necrosis takes place as a primary symptom or a secondary symptom. In all these disease, primary histological changes of hypoplasia and hypertrophy are preceeded by the necrosis of phloem.

• Animal Systematics, Evolution and Diversity
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• v.29 no.4
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• pp.294-307
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• 2013

The burrowing-cricket genus Velarifictorus Randell, 1964 is reviewed in Korea, comparing with morphologically resembled genus Lepidogryllus Otte and Alexander, 1983 for the first time. First, Velarifictorus aspersus borealis Gorochov, 1985 is confirmed from only restricted area of southern regions in Gyeongsangnam-do and Jeollanam-do. Second, Velarifictorus micado (Saussure, 1877) is confirmed from nearly all around the Korean peninsula including North Korea. Third, the previously not recorded Velarifictorus ornatus (Shiraki, 1911) is newly recognized from South Korea. Relating to the genus Velarifictorus, the resembled genus Lepidogryllus Otte and Alexander, 1983 and its species Lepidogryllus siamensis (Chopard, 1961) com. & stat. nov. is studied and compared with Velarifictorus members. A key, descriptions, tables, photographs, figures, oscillograms and spectrograms of calling sounds are provided to aid identification between the four similar species.

• Development and Reproduction
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• v.17 no.2
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• pp.87-97
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• 2013

The seminiferous epithelium cycle and developmental stages of spermatids in Clethrionomys rufocanus were observed under a light microscope. The seminiferous epithelium cycle was divided into 8 stages. Type Ad spermatogonia appeared through all stages. Type Ap, In, and B spermatogonia appeared in stages I, II, III, and IV. In the first meiosis prophase, the leptotene spermatocytes appeared from stage V, the zygotene spermatocytes in stages I, VI, VII, VIII, the pachytene spermatocytes from stages II to VI, the diplotene spermatocytes in stage VII. The meiotic figures and interkinesis spermatocytes were observed in stage VIII. Developing spermatids were subdivided into 10 steps, based on the morphological characteristics such as the acrosome formation changes in spermatozoa, nucleus, cytoplasm, and spermiation changes. The C. rufocanus spermatocytogenesis and spermiogenesis results displayed similar results with Apodemus agrarius coreae and A. speciosus peninsulae. Considering all the results, the spermatogenesis may be useful information to analyze the differentiation of spermatogenic cells and the breeding season.