• Korean Journal of Plant Taxonomy
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• v.32 no.4
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• pp.363-382
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• 2002

Morphological characters of three taxa belonging to three genera (Fuirena, Kobresia, and Scleria) in Korean Cyperaceae were reexamined. The anatomical patterns of stems and leaves, and epidermal patterns of achenes and leaves were investigated by a scanning electron microscope (SEM) and a light microscope (LM). Based upon the results, the scientific and Korean names, which have not been clearly established, were reviewed. Morphological characters such as length and width of stem, leaf, bract, scale, achene, and shape of achene, spikelet, style base, scale, perianth, and anatomical characters such as shape of stem and leaf, shape of achene epidermal cell and silica body of leaf, size and frequency of stomatal complex, presence of bulliform cell were useful for an identification of the three taxa.

• Journal of the Korean Society of Radiology
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• v.16 no.7
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• pp.935-942
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• 2022

In doing interventional treatment under the guidance of ultrasonography, the medical team detects the legion site with ultrasonic equipment at first, and insert angio needle. In this situation, if the position of legion and the depth of inserted needle on the ultrasonographic screen are different from real position and depth, the needle is likely to damage a major blood vessel or tissue. Accordingly, we had wondered how much such differences between screen image and reality, and so decided to examine them. Using five ultrasonographic equipments manufactured from different companies in different years, this study tried to compare the lengths of the needle on the screen images and real lengths of it, and find out the factors affecting skewness of them. This study used hog meat chunk to mimic human flesh, and sausages as the target of needle. It compared penetrating depths of the needle as the images on the five equipments using single sample t test in the SPSS 22 statistical program. It was found that all the errors were statistically significant(<.05). So, this study decided that it was wrong to evaluate performances of the equipments by the makers and ages of them. It is necessary to do periodic quality controls of equipments and improve the skillfulness of sonographers to reduce error rates between real treatment areas and the images of them.

• Proceedings of the Korean Fiber Society Conference
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• 1998.04a
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• pp.249-252
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• 1998

니들펀칭 부직포는 구성 섬유소 집합체(web)를 바늘에 펀칭시켜 통과시킴으로써 섬유소간의 물리적인 결합력을 이용하여 제작한 섬유 구조물을 말한다. 니들펀칭 부직포의 물성에 미치는 인자는 크게 다음 세가지라고 볼 수 있다. 첫째, web을 구성하는 섬유의 물성이다.[1-4] 즉, 구성섬유의 인장성질이나 단면의 모양, 크림프의 존재유무, 섬도, 섬유길이, 마찰특성들이 부직포의 물성에 직접적인 영향을 준다.(중략)

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.247.2-247.2
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• 2014

플라즈마 전파 속도와 전자 온도를 조사하기 위해 ICCD카메라(Intensified Charge-Coupled Device Camera, 이하 ICCD)를 이용하여 대기압 저온 플라즈마제트의 방전 이미지를 촬영하였다. 사용된 플라즈마 제트 장치는 유리관 안에 주사기 바늘형 전극이 들어있는 형태이다. 전극의 내경은 1.3 mm, 외경은 1.8 mm, 총 길이는 39.0 mm이며 재질은 스테인레스강이다. 유리관의 내경은 2.0 mm, 외경은 2.4 mm, 총 길이는 80.0 mm이다. 입력 전압은 3.0 kV이며 구동 주파수는 40 kHz이다. 아르곤과 질소의 혼합가스 비율은 각각 100:1, 98:2, 95:5을 사용하였으며 총 가스유량은 400 sccm이다. 각각의 비율별로 군속도는 267 km/s, 305 km/s, 313 km/s이며 이온 음향 속도는 1.16 km/s, 1.24 km/s, 1.25 km/s이고, 전자 온도는 0.55 eV, 0.63 eV, 0.65 eV로 관찰되었다.

• Korean Journal of Plant Taxonomy
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• v.34 no.4
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• pp.297-319
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• 2004

Morphological characters of 14 taxa in 6 sections Ischnostachya(one taxon), Anomalae(one taxon), Capitellatae (five taxa), Debiles (one taxon), Capillares (one taxon) and Molliculae (five taxa) of genus Carex (Cyperaceae) were reexamined. The epidermal patterns of perigynium, achene and leaf were investigated using by using a scanning eletron microscope (SEM) and a light microscope (LM). Morphological characters such as rhizome, spike, width of leaf, leaf sheath, involucre, involucre sheath, beak of perigynium, perigynium shape, and leaf epidermal patterns were useful for the identification of observed fourteen taxa. The number of spike, arrangement of psitillate or staminate spike and presence of bract were very useful characters to divide the treated 14 taxa into two groups. A key based on data was presented here.

• Education of Primary School Mathematics
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• v.24 no.4
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• pp.203-216
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• 2021

Seeing the elapsed time as a quantity that can be measured is quite challenging for students while making students see it is also challenging for teachers. Tuning on these challenges, this article reports on what learning opportunities elementary teachers provide when they teach elapsed time focusing on quantitative objectification. I observed three mathematics classrooms where the elapsed time was taught by three elementary teachers and did a narrative analysis on the instructions. All three teachers utilized certain tools to support students access to the elapsed time as a quantity. They appropriated various quantitative attributes of the tool. In the case of the analog clock, one teacher tried to quantification the elapsed time with the number of minute hand's turning, while the other teacher indicated the distance of minute hand's moving. One teacher represented the elapsed time with the longitudinal attribute of the time band. Standing on the findings, the didactical implications of various attempts for quantitative objectification of the elapsed time implemented were discussed.

• Korean Journal of Crystallography
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• v.17 no.1
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• pp.14-18
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• 2006

MOCVD 공정방법에 의해 수직정렬된 ZnO 나노선을 합성하고 공정조건 제어에 의해 합성되는 나노선의 물리적, 광학적 특성이 어떻게 변화하는지를 고찰하고자 하였다. 온도 및 산소분압제어 등의 공전변수 제어를 통하여 ZnO 나노 구조체는 나노선, 나노로드 뿐만 아니라 나노바늘 (nano-needle) 등 다양한 구조로 변화되었으며 그 직경 및 길이도 제어가 가능하였다. 전체적으로 양호한 특성의 wurzite 구조를 나타내었으며 기판에 수직인 방향으로 [0001] 방향으로 성장하였다. 광학특성에서는 나노선 직경이 작아질수록 주방출 피크의 천이현상이 관찰되었다.

• Korean Journal of Ichthyology
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• v.10 no.1
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• pp.32-39
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• 1998

Structures of jaw bones, gill rakers and pharyngeal bones of the three Pomadasys species collected from Arafura sea of Indonesia in May 1996 were described and illustrated to compare between species. The percentage of ascending process of premaxillary to head length was 21.6~23.3% in Pomadasys kaakan, 25.4~27.8% in P. maculatus and 15.3~21.0% in P. argyreus. The percentage of ascending process of premaxillary to premaxillary was 54.7~72.8% in P. argyreus, 107.8~114.9% in P. kaakan and 126.7~136.7% in P. maclllatlls. The ascending process of premaxillary of P. argyreus showed a tendency to increase as fish grow. Each jaw in all three grunters had a row of conical teeth exteriorly, but 1 to 5 rows of niddle like teeth interiorly. Among the three species examined, P. maculatus showed the most developed teeth. Pharyngeal bone, appeared to be stronger than jaw teeth, contained dense needle like teeth in P. argyreus, where as that in P. kaakan and P. maculatus had long and slender teeth exteriorly but thicker interiorly. Gill rakers of P. kaakan and P. maculatus are short, but those of P. argyreus are long.

• The Korean Journal of Nuclear Medicine
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• v.39 no.6
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• pp.445-455
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• 2005

Purpose: We developed an animal SPECT system using clinical Philips ARGUS scintillation camera and pinhole collimator with specially manufactured small apertures. In this study, we evaluated the physical characteristics of this system and biological feasibility for animal experiments. Materials and Methods: Rotating station for small animals using a step motor and operating software were developed. Pinhole inserts with small apertures (diameter of 0.5, 1.0, and 2.0 mm) were manufactured and physical parameters including planar spatial resolution and sensitivity and reconstructed resolution were measured for some apertures. In order to measure the size of the usable field of view according to the distance from the focal point, manufactured multiple line sources separated with the same distance were scanned and numbers of lines within the field of view were counted. Using a Tc-99m line source with 0.5 mm diameter and 12 mm length placed in the exact center of field of view, planar spatial resolution according to the distance was measured. Calibration factor to obtain FWHM values in 'mm' unit was calculated from the planar image of two separated line sources. Te-99m point source with i mm diameter was used for the measurement of system sensitivity. In addition, SPECT data of micro phantom with cold and hot line inserts and rat brain after intravenous injection of [I-123]FP-CIT were acquired and reconstructed using filtered back protection reconstruction algorithm for pinhole collimator. Results: Size of usable field of view was proportional to the distance from the focal point and their relationship could be fitted into a linear equation (y=1.4x+0.5, x: distance). System sensitivity and planar spatial resolution at 3 cm measured using 1.0 mm aperture was 71 cps/MBq and 1.24 mm, respectively. In the SPECT image of rat brain with [I-123]FP-CIT acquired using 1.0 mm aperture, the distribution of dopamine transporter in the striatum was well identified in each hemisphere. Conclusion: We verified that this new animal SPECT system with the Phlilps ARGUS scanner and small apertures had sufficient performance for small animal imaging.

• Journal of Plant Biology
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• v.1 no.2
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• pp.5-6
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• 1958

Scdvm rotundifolium LEE, D. B. sp. nov. Korean name: Doonggunip-qwongui-birum The external characteristics of this species are similar to those of Sedum spectabile BOREAU, but the leaf is rounded, the inflorescence is globose, and the color of the ilower is a deeper purplish-red. Description of this species. Root: Perennial, facisculate, rather thick, with several stems. Stem: Fasciculate,15~25cm. high, a little nutate, reddish, putting forth buds on the lower part in the autumn. Leaf: Fleshy, opposite, discoid or broad ovate, no petiole, red, irregular serrate margin, lcaf"base light cordate or round, width and length both 2. 5~4.5 cm. Flower: Tiny flower making the glomerule on stem apex. Calyx: symscpal, 5 parted, green, lanceolatc_ Corolla: 5 petals, beat-shaped, purplish-red. Stamens: 10, five of them opposile and reat of five alternate with petals, filaments same length as petals, anther red, pollen yellow. Pistils: 5, separate, each ovary triangular rhombus, opposite the petals, stigmas' length about Imm. apexes pointed. Collected on October 22, 1957, and July 26, 1958. Habitat: Growing in the rock of Mt. Choowang, North Kyongsang Province. Korea. Korea.