• Korean Journal of Plant Resources
• /
• v.17 no.2
• /
• pp.122-134
• /
• 2004

This study was carried out to investigate the resource plants of Mt. Midong. The resource plant of Mt. Midong was surveyed from March, 2002 to October, 2003. In the result of survey, the vascular plant species in Mt. Midong were summarized as 400 taxa; 85 families, 266 genera, 349 species, 48 varieties and 3 forms. And in the results of survey on resource plants among 400 taxa, we confirmed 162 taxa of ornamental plants(40.5％), 250 taxa of edible plants(62.5 ％), 257 taxa of medicinal plants(64.3％) and 167 taxa of the others(41.8 ％). The six taxa were recorded in the surveyed sites as the Korean endemic plants; Hytomecon hylomeconoides, Filipendula palmata var. glabra, Ajuga spectabilis, Weigela subsessilis, Cirsium setidens and Saussurea seoulensis. The rare and endangered plants designated by Korea Forestry Service were two taxa; Hylomecon hylomeconoides and Polygonatum stenophyllum.

• Korean Journal of Plant Taxonomy
• /
• v.34 no.2
• /
• pp.119-152
• /
• 2004

Allium taxa of Korea were taxonomically reviewed, and classified as three subgenera, ten sections, seventeen species, and three varieties. Among these, Korean endemics were recorded as six taxa; A. koreanum, A. taquetii, A. deltoide-fistulosum, A. linearifolium, A. thunbergii var. deltoides, A. thunbergii var. teretafolium. In addition, A. condensatum, A. splendens and A. maximowiczii proved to distribute only in North Korea. Keys to the subgenera, sections, species and infraspecies with descriptions of each taxon were provided.

• Journal of Digital Convergence
• /
• v.9 no.5
• /
• pp.215-224
• /
• 2011

The purpose of this study is to identify a core competencies of the smart worker which most needed in the Smart Work 2.0 environment and to define the competence model of smart worker that can be most applied to. Smart worker for the core competence model as a originality & innovation competence and social skills, digital capability and the capacity of each organic connection to each other is very necessary. Such a smart worker competencies needed to strengthen the three related to the smart foundation for a smart network that will help encourage a very important role is considered.

• Journal of Digital Convergence
• /
• v.9 no.6
• /
• pp.165-172
• /
• 2011

In this paper, we introduce an integrated performance evaluation model defined by the three indices (evaluation index for each evaluation stage, performance viewpoint, and performance type) and analyze the utilization and satisfaction of the seven public u-IT services implemented from 2008 to 2009 using the proposed model. From the performance results of the public u-IT services, it was found out that most of the research goals initially set by the public u-IT service support projects were satisfied. Furthermore, we suggest improvement directions and promotion strategies of future projects.

• Korean Journal of Environment and Ecology
• /
• v.21 no.2
• /
• pp.176-185
• /
• 2007

This study investigated native Rubus coreanus community in Korea(Ulleung island and Jeju island excepted). The quadrates were located in the middle of the native Rubus coreanus habitats. As the result of the research, the patter of native habitats were found to be divided into mountain roadsides, second-transition rents, severely damaged rents in the mountain, strictly protected regions, and environmentally harsh regions. The research revealed 218 taxa in total, in which 71 families, 165 genera, 18 varieties,1 forma and 199 species were checked in the flora of the native Rubu coreanus habitats. In this flora, the perennial plants appeared in as much as 80.74% proportion and appearance-frequency of the compositae was highest, accounting for 7.80%.

• Korean Journal of Environment and Ecology
• /
• v.25 no.3
• /
• pp.253-266
• /
• 2011

The number of vascular plants in Mt. Cheongwan was 323 taxa, which were consisted of 89 families, 221 genera, 270 species, 47 varieties, and 6 formas. Corylopsis coreana belonged in level II of extinction crisis wild plant were found. Six taxa of Korean endemic plants of 6 families, 6 genera, 5 species, and 1 forma were distributed. And also, 40 taxa of floristic specially plants of which 29 in level I, 2 in level II, 6 in level III, 2 in level IV, and finally 1 in level V were recognized. The ratio of naturalized and urbanization index was 3.72 % and 4.14 %, respectively.

• Journal of Plant Biology
• /
• v.35 no.3
• /
• pp.205-210
• /
• 1992

Size>; and sculpture pattern of pollen grains in seven species and two varieties of the genus Lilium in Korea were examined by LM and SEM, and their evolutionary trends were discussed. Lilium species in Korea can be divided into two groups based on pollen morphology: one is small reticulate group with small pollen grains and lumens, which includes L. concolor var. pulchellum and L. callosum; the other is large reticulate group with large pollen grains and lumens, which includes remaining taxa. It is thought that small reticulate group is more primitive than large reticulate group on the basis of tectum coverage. According to the above results and some morphological characters of salles and perianth segments, L. concolor var. pulchellum and L. callosum are very closely related, and they would be treated under the same subsection.ection.

• Korean Journal of Materials Research
• /
• v.26 no.7
• /
• pp.376-381
• /
• 2016

For the development of a low-melting point filler metal for brazing aluminum alloy, we analyzed change of melting point and wettability with addition of Sn into Al-20Cu-10Si filler metal. DSC results showed that the addition of 5 wt% Sn into the Al-20Cu-10Si filler metal caused its liquidus temperature to decrease by about 30 oC. In the wettability test, spread area of melted Al-Cu-Si-Sn alloy is increased through the addition of Sn from 1 to 5 wt%. For the measuring of the mechanical properties of the joint region, Al 3003 plate is brazed by Al-20Cu-10Si-5Sn filler metal and the mechanical property is measured by tensile test. The results showed that the tensile strength of the joint region is higher than the tensile strength of Al 3003. Thus, failure occurred in the Al 3003 plate.

• Journal of Powder Materials
• /
• v.25 no.5
• /
• pp.402-407
• /
• 2018

Molybdenum silicide has gained interest for high temperature structural applications. However, poor fracture toughness at room temperatures and low creep resistance at elevated temperatures have hindered its practical applications. This study uses a novel powder metallurgical approach applied to uniformly mixed molybdenum silicide-based composites with silicon carbide. The degree of powder mixing with different ball milling time is also demonstrated by Voronoi diagrams. Core-shell composite powder with Mo nanoparticles as the shell and ${\beta}-SiC$ as the core is prepared via chemical vapor transport. Using this prepared core-shell composite powder, the molybdenum silicide-based composites with uniformly dispersed ${\beta}-SiC$ are fabricated using pressureless sintering. The relative density of the specimens sintered at $1500^{\circ}C$ for 10 h is 97.1%, which is similar to pressure sintering owing to improved sinterability using Mo nanoparticles.

• Proceedings of the KSR Conference
• /
• 2004.10a
• /
• pp.1034-1039
• /
• 2004

The major objective of this study is to investigate the effects and application of reinforcement for steel plate girder railway bridge by the external prestressing method. It analyzed the mechanical behaviors of non-ballasted railway bridge with ballast reinforced and external post-tensioning reinforced on the finite clement analysis for the static and dynamic behavior. As a result, the reinforcement of ballasted railway bridge the external prestressing method are obviously effective for the additional dead force which is ballast. The analytical study are carried out to investigate the post-tension force decrease bending behavior and deflection in composite bridge for serviceability. To develop two type FEM model which reflect well the post-tension force transverse distribution behavior of servicing bridge. With the comparing the results of railway bridge with ballast which carried out before the post-tensioning with the results of railway bridge with ballast which carried out after post-tensioning, It is investigated that the additional dead load decrease effect and bending behavior of servicing bridge is effect by the post-tensioning. The reinforcement by using the external tendon can be reducing that structure of a degradation phenomenon by unusual stresses due to additional dead load and other problems.