• Korean Journal of Medicinal Crop Science
• /
• v.15 no.4
• /
• pp.256-260
• /
• 2007

Year-round cultivation of a monocarpic plant Orostachys japonicus should be possible in case to controlling floret flowering. To give some information on its year-round cultivation, this study was carried out to examine the effect of night-break treatment time (June 10, Aug. 25) on its growth, morphological characters, and flowering. Night-break treatment of 2 hours at midnight were done since Aug. 25 and heating were made under $20^{\circ}C$ Samples were taken every 4 weeks from Aug. 25. Growth, morphological and flowering related characters were measured from each sample until March 9. Plant height, inflorescence length, number of leaves including bracts and stem diameter were greater in the earlier treatment than in the later one. Leaves and bracts, floret, stem, root, shoot and total dry weights showed the same response as plant height did to the night-break treatment time. Florets were more formed in the earlier treatment than in the later treatment in which they were flowered only on March 9, meaning that its year-round cultivation should be possible under night-break treatment before bolting and heating during winter season.

• Journal of the Korean Geographical Society
• /
• v.38 no.3
• /
• pp.389-399
• /
• 2003

CRN (Cosmogenic radionuclide) methodology has been a versatile tool applicable to a wide range of geomorphology. This study was underiaken to ascertain the rate of erosion and exposure age of mountain-top detritus (tors and block streams) on Mt. Maneo by employing the concentrations of in-situ produced cosmogenic $^{10}$ Be and $^{26}$ Al from bedrock surfaces that are exposed to cosmic rays. The results suggest that tors on the summit were positioned here during the glacial period but no later than 65ka and block streams have been stabilized also since the last glacial period but no later than 38ka. The tors on the summit have been eroded at a slower rate (9m/Ma) than blocks on the hillslope (15m/Ma) since the initial abrupt exposure of each landform to cosmic rays, suggesting that there is a slight difference in the rate of erosion between the summit and the hillslope, and that the local relief between the two areas has been increased. When the $^{26}$ Al/$^{10}$ Be-$^{10}$ Be concentrations from samples are plotted in Lal's steady-state erosion island, one sample (from a for) has complex exposure histories, which can be explained by the occurrence of multiple chipping event of 5cm to 60cm in length on the surface of the rock.

• Korean Journal of Plant Resources
• /
• v.26 no.1
• /
• pp.1-8
• /
• 2013

This study was conducted to examine the relationship between cone abundance and cone/seed characteristics to improve seed quality and seed orchard management of Pinus koraiensis. The data was collected from P. koraiensis seed orchards at Chungju in 2007. That year was a rich year of cone harvest and the average number of cone per tree was 2.5 times much than that of normal year. We collected the cones from all trees in the sample plot of the seed orchard and investigated morphological characters such as cone length, cone width and cone weight. According to cone abundance per tree, the samples were divided into eight classes and analysed by cone analysis method. There is a decreasing tendency of number of fertile scale, seed potential, percent of filled seeds, seed weight per cone and seed efficiency, when the cone number per tree is increased. Additionally, the implications of the results to seed orchards management of P. koraiensis were discussed.

• Korean Journal of Ecology and Environment
• /
• v.46 no.2
• /
• pp.301-309
• /
• 2013

Between May and August 2012, a massive cyanobacterial bloom with Anabaena has been occurred throughout the North Han River. Sampling was conducted at one station on each lake, L. Uham, L. Cheongpyung, and L. Paldang, where occurred a dense bloom, in 13 July. According to the microscopic examination, the blooms was dominated by one specific filamentous cyanobacterium Anabaena and other phytoplankton. Morphologically, previous literature proven that this Anabaena species is A. crassa (Lemmermann) Komark.-Legn. & Cronberg. However, identification of species in a mixed population is complicated due to limited morphological differences. Therefore, with live sample including trichome, akinete and heterocyst, the sequences of 16S rRNA gene of Anabaena isolates were cloned and analyzed, and three 16S rRNA gene sequences of 1188~1520 bp in length were obtained. It was shown from the homologous analysis results that the obtained 16S rRNA sequences were highly homologous to the relevant sequences of A. crassa in GenBank. The 16S rRNA sequences of 63 species were retrieved from GenBank, and the phylogenetic tree was constructed by using these sequences.

• Journal of Korean Society of Steel Construction
• /
• v.21 no.6
• /
• pp.597-608
• /
• 2009

In this paper, large-deformation elasto-plastic analysis of space frames that considersjoint connection properties is presented. This method is based on the large-deformation formula with finite rotation, which was developed initially for elastic systems, and is extended herein to include the elasto-plastic effect and the member joint connection properties of semi-rigid what?. The analytical method was derived from the Eulerian concept, which takes into consideration the effects of large joint translations and rotations. The localmember force-deformation relationships were obtained from the beam-column approach, and the change caused by the axial strain in the member chord lengths and flexural bowing were taken into account. The effect of the axial force of the member on bending and torsional stiffness, and on the plastic moment capacity, is included in the analysis. The material is assumed to be ideally elasto-plastic, and yielding is considered concentrated at the member ends in the form of plastic hinges. The semi-rigid properties of the member joint connection are considered based on the power or linear model. The arc length method is usedto trace the post-buckling range of the elastic and elasto-plastic problems with the semi-rigid connection. A sample non-linear buckling analysis was carried out with the proposed space frame formulations to demonstrate the potential of the developed method in terms of its accuracy and efficiency.

• Journal of the Korean Geotechnical Society
• /
• v.22 no.4
• /
• pp.95-104
• /
• 2006

For the interests in the economical and safe design of foundation system, the concern on the piled raft or disconnected piled raft foundation system is increasing now. In this study, the behavior and the effects of the disconnected piled raft foundation not studied actively in this country were examined using the triaxial compression tests in place of laboratory model tests. The triaxial test samples were prepared with Jumunjin standard sand and the carbon rods, which simulate the ground soil and piles respectively. After the sample in which carbon rods were arranged was laid inside the triaxial chamber, the confining pressure was applied and then loading test was conducted. To analyze the reinforcing effects of the disconnected piled raft foundation, a few number of tests were carried out by changing the number, the diameter and the length of the model piles. As a result of this study, in the disconnected piled raft foundation system, even though the number of pile is few and the diameter of pile is small, the settlement of the foundation system decreased greatly.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.26 no.1
• /
• pp.185-199
• /
• 1999

The purpose of the present study was to investigate craniofacial patterns in Korean male and female adults, and to compare morphologic differences between different facial types. In order to get configurational groupings, standardized lateral and P-A cephalograms of 174 Korean adults were measured and analyzed with seven angular, nineteen linear, four ratio, and two index measurements. Ward's minimum variance cluster analysis was employed to divide the sample into groups having similar craniofacial morphology, and thereafter, inductive statistics(t-test) was used to characterize morphologic differences of the divided groups. And also, Pearson correlation coefficients were calculated to assess correlation between the cranial dimensions and upper/lower anterior facial height(UAFH, LAFH) in each facial types for both male and female The results were as follows; 1. There existed sexual dimorphism in most of variables except SN-FH angle, palatal plane angle, facial axis angle, facial index, lower anterior facial height ratio and upper facial height ratio. 2. A brachycephalic headform ($0.84{\pm}0.05$) with leptoprosopic facial form ($0.92{\pm}0.05$) was appeared in male, and a mesocephalic headform ($0.86{\pm}0.06$) with leptoprosopic facial form ($0.92{\pm}0.04$) was exhibited in female. 3. Facial types in both male and female subjects were divided into two groups, Group A (mesoprosopic facial type) and Group B (leptoprosopic facial type). The morphologic differences between Group A and Group B were as follows: a. Cranial measurements including index, angular and linear measurements were not found to be different between Group A and Group B in both sexes. b. Increased UAFH, LAFH, and upper/lower anterior dental heights were exhibited in Group Bs of both male and female. c. In both male and female, ramus height and mandible length showed no difference between Group A and Group B. However, genial angle was found to be larger in Group B than Group A. Therefore, the morphologic differences between two groups in male and female were closely related to less favorable anatomic morphology of the mandible. 4. LAFH and UAFH showed no relationships with cranial dimensions in male and female.

• Korean Journal of Medicinal Crop Science
• /
• v.15 no.6
• /
• pp.429-433
• /
• 2007

Shoot weight of Orostachys japonicus should determine its profitability. The study was carried out to measure the effect of nitrogen (N) fertilization level (0, 5, 10, 20kg/10a) on its growth, morphological characters, and flowering. Night-break treatment of 2 hours at midnight were done since Aug. 25 when afterward samples were taken every 4 weeks to Nov. 16. Growth, morphological and flowering related characters were measured from each sample. Plant height, inflorescence length, number of leaves including bracts and stem diameter were decreased with increased N levels. Leaf and bract, floret, shoot and total dry weights as well as withering rate showed similar response to the above morphological characters. Florets were less formed with increased N levels but were not flowered due to the night-break treatment, meaning that N fertilization had little effect on its growth and anthesis of the florets.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.9
• /
• pp.382-389
• /
• 2019

A novel folding process is proposed using a repeated cold-die forging and annealing to form a sterling silver ring. Sterling silver plate was cut into a doughnut shape, and lattices with 0.43-mm line-width were imprinted on it. The sample was folded by forging using dies with slopes of $45^{\circ}$, $60^{\circ}$, and $75^{\circ}$ and annealing. For comparison, samples were also fabricated without annealing. Strain was identified by measuring the length of lattices. Vernier calipers, a Vickers hardness tester, an optical microscope, and a UV-VIS colorimeter were used to determine the size, hardness, microstructure, and body color. Without annealing, cracks occurred. However, successful deformation was possible when annealing was used. The results of macro strain measurements show that the outer diameter and width decreased, while the inner diameter and thickness increased after the final process. The maximum strain was increased 0.128 toward the parallel direction. The Vickers hardness decreased after annealing and increased after the folding process. The microstructure results showed that the grain size increased after annealing but decreased after folding. The color difference based on the Lab index was under 10 for all processes. Eventually, a doughnut-shaped silver plate was successfully deformed into a ring shape by the folding process.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.17 no.1
• /
• pp.21-30
• /
• 2004

This study deals with free vibrations of laminated composite structures with a channel section using finite element method. In this paper, the mixed finite element method using Lagrangian and Hermite interpolation functions is adopted and a high-order plate theory is used to analyze laminated composite non-prismatic folded plates with a channel section more accurately for free vibration. The theory accounts for parabolic distribution of the transverse shear stress and requires no shear correction factors supposed in the first-order plate theory. An 32×32 matrix is assembled to transform the system element matrices from the local to global coordinates using a coordinate transformation matrix, in which an eighth drilling degree of freedom (DOF) per node is appended to the existing 7-DOF system. The results in this study are compared with those of available literatures for the conventional and first-order plate theory. Sample studies are carried out for various layup configurations and length-thickness ratio, and geometric shapes of plates. The significance of the high-order plate theory in analyzing complex composite structures with a channel section is enunciated in this paper.