• Journal of the Korean earth science society
• /
• v.26 no.7
• /
• pp.725-731
• /
• 2005

The distribution and kinematic information of the planetary nebula (PN) may provide a hint about the Galactic dynamics and evolutionary history. An analysis of the Galactic planetary nebular distribution and kinematics (distance, direction, velocity) is underwent, using the 502 PNs observational data given in the ‘THE STRASBOURG-ESO CATALOGUE OF GALACTIC PLANETARY NEBULAE.’ The representative average radial velocities, $(V_r)s$ is derived in six different directions of galactic latitudes, $l = 0^{\circ},\;90{\circ},\;180{\circ},\;270{\circ},$ plus apex and antapex $(56{\circ},\;236{\circ})$, respectively. The PNe near the apex approaches to the Sun with radial velocities, which values are $(V_r) = 69.0 km/s;$ whereas, those near the antapex recedes with $(V_r) = 64.1 km/s$, respectively. No particular trends are found along the z direction, although more PNs are found below the Galactic plane. This implies that the 3rd generation objects, PNs, move slowly on the galactic plane compared to the 4th generation stars like the Sun, indicative of possible interaction.

• Korean Chemical Engineering Research
• /
• v.52 no.1
• /
• pp.8-16
• /
• 2014

Microalgae have been considered as a promising microorganism in the field of bio-industry due to their abilities to fix carbon dioxide as well as biosynthesize valuable secondary metabolites. Of many lighting sources for microalgal cultivation, LED (Lighting Emitting Diode) has been emerged as the appropriate choice with multiple advantages over the conventional bulbs. However, it is only in recent years that we have witnessed the possibility of application of LED into microalgae cultivation system. LED will serve as an evolutionary lighting source for microalgae cultivation system and open the frontier for integrative bio-industries. In this paper, we present the comprehensive review on the recent trends of LED applications into microalgal biotechnology.

• Korean Journal of Plant Taxonomy
• /
• v.41 no.4
• /
• pp.338-344
• /
• 2011

Molecular phylogenetic studies were conducted to evaluate evolutionary trends, relationships and species identities among four species, one variety and one outgroup of the Korean Genus Calystegia. The important characteristics of Calystegia are the shape of the lamina, the length ofthe corolla and the presence of hair. However, many variations were observed as regards the characteristics of the leaf, making true identification difficult. In molecular phylogenetic studies, C. soldanella formed one clade, and it was located mostly in the base. C. hederacea and C. sepium did not form an independent clade in their ITS regions and psbA-trnH regions, and this investigation could not confirm a relationship. Therefore, a relationship between these two species is not sufficiently supported by these markers (ITS and psbA-trnH). Consequently, this research should be achieved through many samples and markers. C. sepium var. japonica and C. dahurica are closely related.

• Anatomy & Biological Anthropology
• /
• v.31 no.4
• /
• pp.105-119
• /
• 2018

Archaeogenetics is an academic discipline that aims to establish scientific facts of human history by integrating ancient DNA analyses with archaeological and anthropological evidence. After ancient DNA research was initiated about 30 years ago, it has been innovated so rapidly that the range of analysis has been extended toward the whole genome sequence of ancient genomes in recent 10 years. By this development, researchers have been able to study in detail the origins and migration patterns of hominin species and ancient human populations by approaches of evolutionary genetics. This study has reviewed main principles of the archaeogenetic analysis and the current trends of ancient genome studies with recent achievements. While sampling techniques and statistical analyses have been improved, typical research methods have been established by the findings on hominins and ancient western Eurasia populations. Recently, archaeogenecists have been applying the methods to studying those in other geographical areas. Nonetheless, there is still the lack of ancient genome research about populations in Eastern Asia including the Korean peninsula. This review ultimately aims to predict possibilities and promise of future ancient genome studies of ancient Korean populations.

• Korean Journal of Environment and Ecology
• /
• v.34 no.5
• /
• pp.358-371
• /
• 2020

As climate change is expected to lead to a severe reduction of biodiversity, studies to investigate the reasons for habitat loss, growth decline, and death of Korean fir (Abies koreana Wilson), endangered alpine/subalpine species in Korea, have been conducted for years but found no clear answer yet. This study reviewed previous studies on Korean fir published in the journals in the past 40 years, 1980 through 2020, into 10-year units, examined the study trend by period, region, and subject with a focus on ecological studies, and analyzed the study results. The ecological studies were categorized into evolutionary ecology, physiological ecology, population ecology, and landscape ecology. Based on the results, we suggested the required research fields in the future. We found a total of 73 papers published in the past 40 years and 48 (65.8%) of them published in the past 10 years. In terms of region, Mt. Halla accounted for the most as 41 papers were on it. In terms of ecological subjects, the physiological ecology accounted for the most with 38, and the evolutionary ecology accounted for the least with 10. The review of the study results showed that many studies identified water stress caused by the water resource imbalance due to temperature increase and spring precipitation reduction following climate change as the main reason for the decline and habitat loss of Korean fir. However, recent studies suggested other factors, such as soil environment, disturbing organisms, and climatic events. The cause of the decline and death of the Korean fir not yet being clearly identified is that most of the studies dealt with the basic content, were carried out intermittently, and were concentrated in some regions. Therefore, we need long-term studies with advanced technology in each study subject at a local scale to find the cause of Korean fir decline and present sustainable management and conservation. Moreover, it is necessary to extend our study subjects to ecosystem ecology and systems ecology to integrate the results from various study subjects for a comprehensive understanding of the reason for Korean fir declines. The results of comprehensive studies could provide clearer answers for Korean fir's declines and the alternatives of conservation management and practices.

• Korean Journal of Plant Resources
• /
• v.16 no.1
• /
• pp.89-98
• /
• 2003

Pollens of six taxa in the genus Atractytis L. confused with Atractylodes DC. were investigated by the light and the scanning electron microscope. Pollen grains of six taxa in this genus were monads, 46.5-66.7$\mu\textrm{m}$ in length of polar axis, 43.6-60.47$\mu\textrm{m}$ in equatorial width. Aperture was tri-colporate, 19.6-29.1 $\mu\textrm{m}$ in colpus length,7.3-11.0$\mu\textrm{m}$ in colpus width and 6.4-10.6$\mu\textrm{m}$ in porus diameter. The exine was composed of three layers(foot layer, columellne, tectum), and 5.2-8.3 $\mu\textrm{m}$ in thickness. The surface sculpturing pattern was echinate, the spines were 1.4-5.8$\mu\textrm{m}$ in length and 6-33 per 20$\mu\textrm{m}$$^2$ in distribution numbers over the surface. Atractylis L. was not distinguished from Atractylodes DC. by pollen morphology, especially the pollens of Atractylis arabica, A. aristata, A. carduus, A. microcephala were very similar to that of Atractylodes. But its taxonomic significance was different, the taxa of Atractylodes DC. were divided into 2 types by only pollen size, but the treated taxa in this study were divided into various types by pollen size, shape of equatorial view, surface sculpturing and spine size. The characteristics of spine size and shape of equatorial view in A. cancellata and A. prolifera were very useful for consideration of evolutionary trends in this genus.

• Journal of the Korean Applied Science and Technology
• /
• v.37 no.4
• /
• pp.944-957
• /
• 2020

This study is an integrated literature review of concept analysis research published in the Journal of the Korean Nursing Society and the journal of branch science for the last 10 years from 2009 to 2018. A total of 30 papers were analyzed, including the metaparadigm of nursing, the type of concept, the method of concept analysis, the degree of utilization, etc. As a result, the metaparadgim of nursing was the most common human being, with 23 human beings, 5 nursing, 1 health, and 1 environment, and all kinds of concepts were identified as abstract concepts. As for concept analysis methods, Walker & Avent had the most number of workers and events with 13 workers, 10 hybrids, and 7 evolutionary methods, but all of them were hybrid methods after 2018. The progress toward tool development has not been confirmed. The diversity of nursing paradigm based on research results and the development of tools based on it are also necessary.

• Journal of the Korean Geographical Society
• /
• v.40 no.4 s.109
• /
• pp.387-401
• /
• 2005

This research reviews how tourism geography studies in Anglo-American tradition have evolved since 1930s. The purposes of the research are two fold. One is to analyze the change of tourism geographies research trends in terms of research approach and major research themes. The other is to bring out the lessons from the research results for the development of Korean tourism geographies research. For these purposes, the selected papers and texts have been analyzed according to four research approaches: (1) empiricist approach, (2) positivist approach, (3) humanist approach, and (4) critical social theory approach. The major research themes are the explanation of destination through descriptive research in empiricist approach, spatial analysis and evolutionary research in positivist approach, tourist behaviour and place identity in humanist approach, and tourism and consumption in critical social theory approach. It is expected that the development of Anglo-American tourism geographies study will continue in the future because of the growth of tourism industry, the close relation of tourism and geography in nature, and the active contribution of tourism geographers.

• The Bulletin of The Korean Astronomical Society
• /
• v.36 no.1
• /
• pp.83.1-83.1
• /
• 2011

We report multi-epoch, simultaneous 22 GHz water and 44 GHz Class I methanol maser line survey towards 180 intermediate-mass young stellar objects, including 14 Class 0, 19 Class I objects, and 147 Herbig Ae/Be stars. We detected $H_2O$ and $CH_3OH$ maser emission towards 16 (9%) and 10 (6%) sources with one new $H_2O$ and six new $CH_3OH$ maser sources. The detection rates of both masers rapidly decrease as the central (proto)stars evolve, which is contrary to the trends in high-mass star-forming regions. This suggests that the excitations of the two masers are closely related to the evolutionary stage of the central (proto)stars and the circumstellar environments. $H_2O$ maser velocities deviate on average 9 km s-1 from the ambient gas velocities whereas $CH_3OH$ maser velocities well match with. For both maser emissions, large velocity difference (${\mid}v_{H2O}-v_{sys}{\mid}\;>\; 10kms^{-1}\; and\;{\mid}v_{CH3OH}-v_{sys}{\mid}\;>\;1kms^{-1}$) is mostly confined to Class 0 objects. The formation and disappearance of $H_2O$ maser lines are frequent and the integrated intensities of them change up to two orders of magnitude. In contrast, $CH_3OH$ maser lines usually show no significant change in the intensity, shape, and velocity. This consistent with the previous suggestion that $H_2O$ maser emission originates from the base of an outflow while 44 GHz Class I $CH_3OH$ maser emission arises from the interaction region of the outflow with the ambient gas. The isotropic maser luminosities are well correlated with the bolometric luminosities of the central the objects. The fitted relations are $L_{H2O}=1.71{\ast}10^{-9}(L_{bol})^{0.97}$ and $L_{CH3OH}=1.71{\ast}10^{-10}(L_{bol})^{1.22}$.

• Korean Journal of Plant Taxonomy
• /
• v.35 no.1
• /
• pp.7-23
• /
• 2005

Molecular phylogenetic studies were conducted to evaluate interspecific relationships in 40 populations of Viola including 35 Korean taxa, four Japanese populations and one outgroup using nuclear ribosomal ITS sequences. The phylogenetic analyses were conducted using parsimony and neighbor-joining methods. Subsection Trigonocarpae of section Nomimium appeared as the most basal clade within the Korean Viola. Section Dischidium and Chamaemelanium was monophyletidbootstrap 100%) and placed between subsect. Trigonocarpae and three other subsections of sect. Nomimium. Sect. Nomimium was paraphyletic. Although each subsectional grouping was in accordance with previous infrageneric classification based on morphological characters, yet discordance remained at the series level. Two evolutionary trends observed in the ITS tree were as follows. First, subsect. Trigonocarpae(x=10) was derived from the outgroup(x=6); Second, subsects. Bilobatae and Vaginatae(x=10 or 12), and subsect. Patellares(x=12) of sect. Nomimium were originated from sects. Dischidium and Chamaemelanium(x=6). Viola albida complex including three very closely related taxa was recognized as independent group within subsect. Patellares in parsimony tree. This result suggested that they should be treated as a taxa in series Pinnatae. Phylogenetic position of a putative hybrid species, Viola woosanensis was not supported with previous morphological hypothesis.