• Journal of Ecology and Environment
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• v.39 no.1
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• pp.51-60
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• 2016

This study was conducted to examine litter fall, litter decomposition, and a short-term nutrient (C, N, P, K, Ca, and Mg) status for one year at various levels of basal area (21.4, 27.0, 30.8, 37.0, 42.1, and 46.7 m² ha^-1) in approximately 40-yearold red pine (Pinus densiflora S. et Z.) stands in the Hwangmaesan mountain forest in Korea. Monthly fluxes of litter fall components such as needles, broad leaves, branches, bark and total litter fall followed a similar pattern at various levels of basal area. Mean annual needle, bark and total litter fall fluxes were positively correlated with increased basal area (p<0.05), but the woody litter such as branches and cones was not correlated with basal area. Carbon and K concentrations of needle litter were negatively correlated with increased basal area, while nutrient (C, N, P, K, Ca, and Mg) fluxes were positively correlated with the basal area treatments. Remaining mass, N and P concentration and remaining N and P stocks in decomposing needle litter were not affected by the basal area. However, the concentration and stocks remaining of K, Ca, and Mg from decomposing litter were positively correlated with increased basal area during the initial three months of decomposition. The results indicate that basal area has an impact on nutrient cycles through change in litter fall and litter decomposition processes; thus, the dynamics of nutrient cycles based on a stand scale could differ considerably with different levels of basal area in red pine stands.

• Journal of the Korean School Mathematics Society
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• v.13 no.4
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• pp.549-568
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• 2010

This paper analyzed the topics dealing with three-dimensional figures in most recently revised mathematics textbooks on the basis of the national mathematics curriculum announced in 2007. First, the overall content was analyzed with regard to how textbooks were aligned to the curriculum as well as how the main elements including the definitions of specific solid figures were introduced and developed in different units across grades. Second, the instructional methods of three-dimensional figures were analyzed, which specifically revealed the lack of inquiry phase before introducing cones and pyramids. Third, the instructional methods to foster students' spatial sense with solid figures were analyzed, which showed the increased focus on the prediction and representation of figures. It is expected that the issues and suggestions from this study are informative revising curricular materials and applying them to the classroom.

• Journal of the Ergonomics Society of Korea
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• v.29 no.2
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• pp.203-210
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• 2010

For the development of a better product which fits to the target user population, physical workloads such as reach and visibility are evaluated using digital human simulation in the early stage of product development; however, ergonomic workload assessment mainly relies on visual observation of reach envelopes and view cones generated in a 3D graphic environment. The present study developed a quantitative assessment method of physical workload in a digital environment and applied to the evaluation of a Korean utility helicopter (KUH) cockpit design. The proposed assessment method quantified physical workloads for the target user population by applying a 3-step process and identified design features requiring improvement based on the quantified workload evaluation. The scores of physical workloads were quantified in terms of posture, reach, visibility, and clearance, and 5-point scales were defined for the evaluation measures by referring to existing studies. The postures of digital humanoids for a given task were estimated to have the minimal score of postural workload by finding all feasible postures that satisfy task constraints such as a contact between the tip of the index finger and a target point. The proposed assessment method was applied to evaluate the KUH cockpit design in the preliminary design stage and identified design features requiring improvement. The proposed assessment method can be utilized to ergonomic evaluation of product designs using digital human simulation.

• Korean Journal of Plant Taxonomy
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• v.44 no.4
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• pp.288-297
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• 2014

The aim of this study is to analyse misinformation about gymnosperm taxon used for over 57 years, since 1957 when plant biology as a discipline was established in our country. That is, terminologies and descriptions of the reproductive structure (flower) of angiosperms (flowering seed plants) have been incorrectly applied to the reproductive structures (typically cones and pollen grain) of gymnosperms (non-flowering seed plants) by numerous and various media such as text books, dictionaries, and internet websites for plant biology. Thus, these resources have been misleading teachers, students, and other people interested in plant biology in general and taxonomy in particular by describing gymnosperm reproductive structures as if they are the same as angiosperms. Such a practice has an especially adverse effect on plant biology education at all levels of instruction, with teachers and students confused in their understanding of the concept and definition of a flower. In this paper, these incorrect expressions for the reproductive structures of gymnosperms from the various media are analysed and discussed in terms of cladogram, anatomy of reproductive structures, and historical context of classification systems.

• Korean Journal of Plant Taxonomy
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• v.48 no.1
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• pp.43-47
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• 2018

Pimpinella saxifraga L. (Scarlet pimpernel or Burnet saxifrage), a newly introduced species, was found from Baekyakyi oreum (a parasitic cone or cinder cone) in Seogwipo, Jejudo Island. This species is native to Europe and western Asia and is reported as a widely invasive species around the world. Pimpinella saxifraga is distinguished from other related Korean taxa by leaves that are pinnately compound with 3-7 pairs of segments, which vary from simple, ovate, to 2-pinnatisect, with linear lobes. The vernacular name of "Baek-yak-yi-cham-na-mul" was assigned after the name of the cinder cone where it was initially discovered. We provide descriptions of the morphological characters, photographs and a key to allied taxa in Korea. The geographical origin and introduction routes are unknown, but it is highly likely that it was introduced as fodder given its high nutritious value for sheep and cattle or as a medicinal herb. This species invades commonly grasslands and woodlands and prefers dry, well-drained, and calcareous soils. The distribution of this species was analyzed by searching extensively in surrounding Baekyakyi oreum and adjacent cinder cones, but no other populations were observed. It is protected commonly at the edges or inside of the patchy pine forest in the cinder cone from grazing by cattle; given the worldwide invasive nature of this species, special monitoring and management plans should be developed.

• Journal of the Korea Computer Graphics Society
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• v.20 no.2
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• pp.13-24
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• 2014

In this study, a graphics-processing-unit (GPU)-based acceleration technique is proposed for the feature-based image morphing. This technique uses the depth-buffer of the graphics hardware to calculate efficiently the shortest distance between a pixel and the control lines. The pairs of control lines between the source image and the destination image are determined by user's input, and the distance function of each control line is rendered using two rectangles and two cones. The distance between each pixel and its nearest control line is stored in the depth buffer through the graphics pipeline, and this is used to conduct the morphing operation efficiently. The pixel-unit morphing operation is parallelized using the compute unified device architecture (CUDA) to reduce the morphing time. We demonstrate the efficiency of the proposed technique using several experimental results.

• Korean Journal of Ichthyology
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• v.20 no.2
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• pp.97-104
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• 2008

Comparative study of retinal structure in two Korean endemic freshwater fishes, Zacco koreanus and Pseudobagrus koreanus, was carried out by light and scanning electron microscopy. In the visual cell layer comprised of cone cells and rod cells, the cone cells showed a distinct difference between both species. Z. koreanus had two types of cone cells, single cone cells including a long single and short single cone cells, and double cone cells, whereas P. koreanus had only one type of single cone cells having no its short single and long single cones. Meanwhile, the cone cells of Z. koreanus were arranged in more compact-rowed pattern, but it was more loose and irregular in P. koreanus. Based on field observation, Z. koreanus is mainly a epipelagic or sometimes benthopelagic and a diurnal fish with a round and large eye, while P. koreanus is a demersal and nocturnal fish with an oval and small eye. Therefore, the difference in the retinal structure of two species seems to be closely related to their ecological habitats.

• Journal of Korean Society of Forest Science
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• v.84 no.3
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• pp.356-360
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• 1995

Korean white pine(Pinus koraiensis S.et Z.) is one of the important silvicultural species due to its quality timber in addition to edible pine - nut production. Selective breeding method is under progress to improve growth and nut production for this species. This study was carried out to obtain genetic information necessary for establishing advanced generation seed orchard, such as genetic parameters and efficiency of early selection. Open - pollinated cones were collected from 50 plus trees. In the spring of 1986, test plantations were established at 3 different sites with 4 - year - old seedlings. Seedling height was measured from age 5 to 10 in plantations. Genetic and phenotypic correlations based on the log of the ratio of two ages (LAK) were expressed as simple regression with statistical significance($r^2=0.7862$ and 0.8256, respectively). If 20 years is presumed to mature, the most efficient age for early selection is 3 years after planting with efficiency of 1.96.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.40 no.5
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• pp.220-224
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• 2014

Objectives: This study aimed to assess and compare the levels of interleukin-1beta (IL-$1{\beta}$) and interleukin-6 (IL-6) in the crevicular fluid around healthy implants, implants with peri-implantitis, and healthy teeth. Materials and Methods: This study evaluated 16 dental implants in 8 patients (4 males and 4 females). These patients had at least one healthy implant and one implant with peri-implantitis next to healthy teeth. The crevicular fluid was collected using absorbent cones and transferred to the laboratory. Specimens were evaluated by ELISA for interleukin levels. Data were analyzed using repeated measures ANOVA and Bonferroni tests (P<0.05). Results: Levels of IL-$1{\beta}$ in the crevicular fluid around implants with peri-implantitis were significantly higher than around healthy implants (P=0.002); the latter was significantly higher than around healthy teeth (P=0.015). A significant difference was found in the level of IL-6 in the crevicular fluid around implants with peri-implantitis and healthy implants (P=0.049) and also between implants with peri-implantitis and healthy teeth (P<0.001). Conclusion: Within the limitations of this study, significant differences exist in the levels of IL-$1{\beta}$ and IL-6 in the crevicular fluid of implants with peri-implantitis, healthy implants, and healthy teeth. More studies with larger sample sizes in different populations are necessary.

• The Journal of Korean Society for Radiation Therapy
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• v.20 no.2
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• pp.123-130
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• 2008

Purpose: To provide practical education, most universities should be equipped with medical appliances in need. As compensatory measures, Gimcheon College has produced in-house dummy linac and dummy accessories, we are going to report efficiency and its usage. Materials and Methods: Dummy linear accelerator (DLINAC-001) has the same mechanical functions as rotation of gantry and collimation in linear accelerator. In addition, to maximize practical education, we have produced and utilized in-house custom blocks, wedge filters, electron cones and head rests. Results: The in-house produced linear accelerator with the same mechanical functions as the linear accelerator, DLINAC-001 can be effectively used in practicing diverse medical instruments. Conclusion: We have produced dummy linear accelerators and dummy accessories and utilized them in practice classes, which can provide the students with clinical training in diverse fields. Consequently, the students exposed to the maximized educational effectiveness can be easily equipped with the practical competence required in real clinical fields.