• Title/Summary/Keyword: Large Spatial Structure

Search Result 452, Processing Time 0.029 seconds

The Exotic Flora of Korea: Actual List of Neophytes and Their Ecological Characteristics (한국의 귀화식물: 신귀화식물상의 현황과 생태형질 특성)

  • Ryu, Tae-Bok;Kim, Jong-Won;Lee, Seung-Eun
    • Korean Journal of Environment and Ecology
    • /
    • v.31 no.4
    • /
    • pp.365-380
    • /
    • 2017
  • Rapid changes in the flora of exotic species are ecological problems that cause the alteration of national and regional biota. The purpose of this study is to identify the reality of neophyte flora currently inhabiting in Korea. Having analyzed a total of 151 studies published up until 2016, we found the qualitative and quantitative gaps among the preceding studies due to the lack of rigorousness on the application of the spatial and temporal level of exotic species and academic terminology. In this study, the neophyte is defined as the flora introduced temporarily after the Enlightenment in Korea (late 19th century) and spatially in the Eastern Asiatic Province of the Takhtajan's floral region instead of a country boundary. A total of 326 taxa of 184 genera of 39 families were identified and analyzed for their distributional origin and habitat characteristics. Approximately 87% (285 taxa) was a component of the single-layered herb vegetation, and a total of 211 taxa originated from Europe and North America which are the same temperate biome as Korea. The wetland vegetation components were much fewer with 21 taxa, but they included a large number of invasive alien species that caused critical deterioration in the habitat structure and function of aquatic ecosystems. Ecological approaches to exotic species categories such as Ephemerophyten and Apophyten have emerged.

Microtube Light-Emitting Diode Arrays with Metal Cores

  • Tchoe, Youngbin;Lee, Chul-Ho;Park, Junbeom;Baek, Hyeonjun;Chung, Kunook;Jo, Janghyun;Kim, Miyoung;Yi, Gyu-Chul
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2016.02a
    • /
    • pp.287.1-287.1
    • /
    • 2016
  • Three-dimensional (3-D) semiconductor nanoarchitectures, including nano- and micro- rods, pyramids, and disks, are emerging as one of the most promising elements for future optoelectronic devices. Since these 3-D semiconductor nanoarchitectures have many interesting unconventional properties, including the use of large light-emitting surface area and semipolar/nonpolar nano- or micro-facets, numerous studies reported on novel device applications of these 3-D nanoarchitectures. In particular, 3-D nanoarchitecture devices can have noticeably different current spreading characteristics compared with conventional thin film devices, due to their elaborate 3-D geometry. Utilizing this feature in a highly controlled manner, color-tunable light-emitting diodes (LEDs) were demonstrated by controlling the spatial distribution of current density over the multifaceted GaN LEDs. Meanwhile, for the fabrication of high brightness, single color emitting LEDs or laser diodes, uniform and high density of electrical current must be injected into the entire active layers of the nanoarchitecture devices. Here, we report on a new device structure to inject uniform and high density of electrical current through the 3-D semiconductor nanoarchitecture LEDs using metal core inside microtube LEDs. In this work, we report the fabrications and characteristics of metal-cored coaxial $GaN/In_xGa_{1-x}N$ microtube LEDs. For the fabrication of metal-cored microtube LEDs, $GaN/In_xGa_{1-x}N/ZnO$ coaxial microtube LED arrays grown on an n-GaN/c-Al2O3 substrate were lifted-off from the substrate by wet chemical etching of sacrificial ZnO microtubes and $SiO_2$ layer. The chemically lifted-off layer of LEDs were then stamped upside down on another supporting substrates. Subsequently, Ti/Au and indium tin oxide were deposited on the inner shells of microtubes, forming n-type electrodes of the metal-cored LEDs. The device characteristics were investigated measuring electroluminescence and current-voltage characteristic curves and analyzed by computational modeling of current spreading characteristics.

  • PDF

Oceanographic Condition of the Coastal Area between Narodo Is. and Solido Is. in the Southern Sea of Korea and Its Relation to the Disappearance of Red-Tide Observed in Summer 1998 (한국 남해 나로도와 소리도 사이 해역의 1998년 하계 해황 및 적조소멸과의 관계)

  • Choi, Hyun-Yong
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
    • /
    • v.6 no.2
    • /
    • pp.49-62
    • /
    • 2001
  • Hydrographic surveys were carried out seven times during May 31, 1998 and September 24, 1998 in order to study the physical environments of the coastal area between Narodo Is. and Sorido Is. in the southern sea of Korea (the South Sea) where the occurrence of Cochlodinium polykrikoides red tide is frequently observed in summer. Temperature and salinity of the water column from the surface to the depth of 30 m exhibit large seasonal variations. Mean temperature of the water column increased by 6 and mean salinity of the water column decreased by 2.71 psu during the observation period. Both the freshwater supplied from the adjacent land and the precipitation over the study area cannot account for the observed salinity variations. The influx of the low salinity water from the offshore area is considered to be the main cause for the observed salinity changes. Surface salinity in the study area shows different spatial distribution in the period of outbreaking, mid-stage and disappearance of the red tide. Especially, salinity was abruptly lowered at the stage of disappearance of red tide as compared to salinity of the previous observation period. Vertical structure of water properties also became vertically homogeneous at the disappearance stage, while it was highly stratified in the previous observation. Such changes can only be explained by the inflow of low salinity water from the offshore, which is considered as the most possible cause for the disappearance of the red tide in the study area. This study suggests that exchanges of water, and chemical and biological factors between coastal areas and of shore area in the South Sea need to be studied in association with the general circulation of the South Sea in order for the better understanding of the occurrence and disappearance of the red tide in the coastal area of the South Sea.

  • PDF

VISUALIZATION AND MEASUREMENT OF A NARROW-CONE DI GASOLINE SPRAY FOR THE IMPINGEMENT ANALYSIS

  • Park, J.S.;Im, K.S.;Kim, H.S.;Lai, M.C.
    • International Journal of Automotive Technology
    • /
    • v.5 no.4
    • /
    • pp.221-238
    • /
    • 2004
  • Wall interactions of direct injection spray were investigated using laser-sheet imaging, shadowgraphy, wetted footprint and phase Doppler interferometry techniques. A narrow-cone high-pressure swirl injector is used to inject iso-octane fuel onto a plate, which has three different impact angles inside a pressurized chamber. Heated air and plate conditions were compared with unheated cases. Injection interval was also varied in the heated case to compare dry- and wet- wall impingement behaviors. High-speed macroscopic Mie-scattering images showed that presence of wall and air temperature has only minor effect on the bulk spray structure and penetration speed for the narrow-cone injector tested. The overall bulk motions of the spray plume and its spatial position at a given time are basically unaffected until a few millimeters before impacting the wall. The surface properties of the impact surface, such as the temperature, the presence of a preexisting liquid film also have a small effect on the amount of wetting or the wetted footprint; however, they have strong influence on what occurs just after impact or after a film is formed. The shadowgraph in particular shows that the plate temperature has a significant effect on vapor phase propagation. Generally, 10-20% faster horizontal vapor phase propagation is observed along the wall at elevated temperature condition. For impingement onto a preexisting film, more splash and evaporation were also observed. Contrary to some preconceptions, there is no significant splashing and droplet rebounding from surfaces that are interposed in the path of the DI gasoline spray, especially for the oblique impact angle cases. There also appears to be a dense spray front consists of large sac spray droplets in the oblique impact angle cases. The bulk of the spray is not impacted on the surface, but rather is deflected by it The microscopic details as depicted by phase Doppler measurements show that the outcome of the droplet impaction events can be significantly influenced. Only droplets at the spray front have high enough Weber numbers for wall impact to wet, splash or rebound. Using the sign of vertical velocity, the time-resolved downward droplets and upward droplets are compared. The Weber number of upward moving droplets, which seldom exceeds unity, also decreases as the impact angle decreases, as the droplets tend to impact less and move along the wall in the deflected spray plume.

A Study on Environmental Design Treatments of Subway Stations in Terms of Visual Cues for Place Indication - Focused on the Cases of Seoul, Tokyo and Taipei - (장소지시단서로서의 지하철역 환경디자인 기법에 관한 연구 -서울, 동경, 타이페이 사례를 중심으로-)

  • Park, Hey-Kyung
    • Archives of design research
    • /
    • v.19 no.5 s.67
    • /
    • pp.351-362
    • /
    • 2006
  • Currently, finding one's way in the underground spaces associated with subway stations in large cities is becoming a serious problem, and an environment that facilitates wayfinding is becoming more important. This study investigated interior treatments that function as visual cues in the subway stations of Seoul, Tokyo, and Taipei in order to develop design guidelines that would improve the place-cognition environment. A theoretical study has shown that there are three categories of visual cue for place cognition: marked trails, regional differentiation, and landmarks. The case study showed that marked trails involve treatments like vertical markers, confrontational positioning, and subway color codes. Regional differentiation involves patterns on the floors and walls, and accent colors on the walls and columns. Landmarks include treatments such as super graphics, symbolic features, artistic decoration and special lights. In the cases of Seoul, marked trails and regional differentiation were predominant. In addition, the Olympic symbol 'Hodori' and the ancient Korean character "Hunminjungeum" were used as landmarks. In the cases of Tokyo, regional differentiation predominated over marked trails because of the complexity of the spatial structure and subway line connection system. In the cases of Taipei, simple, unified images predominated, and there was minimal dependence on marked trails and landmarks. The need for regional differentiation was weak, because the stations studied have open structures that guarantee an open field of view. The results of this research could be used as design guidelines, after further experimental verification, that would help to improve the public environment in terms of wayfinding.

  • PDF

Meiofauna Community from Sandy Sediments Near Taean in the Yellow Sea, Korea (서해 태안 사질 퇴적물에 서식하는 중형저서동물 군집구조 연구)

  • Back, Jin-Wook;Kim, Ki-Choon;Lee, Seung-Han;Lee, Kang-Hyun;Lee, Dong-Ju;Chae, Jin-Ho;Lee, Won-Choel
    • Ocean and Polar Research
    • /
    • v.31 no.2
    • /
    • pp.199-212
    • /
    • 2009
  • The community structure of meiofauna was surveyed from six stations in sand mining area near around Sungapdo, Taean five times from April-December, 2007. Ten meiofaunal taxa in total, comprising 5-9 taxa per station were recovered. Nematodes were dominant from four stations in April and from five stations in May. In June, copepods were dominant from all stations except station two, from which sarcomastigophorans were predominant. Copepods were also dominant from three stations in October and four stations in December. The mean density of meiofauna per $10\;cm^{-2}$ was the highest in October (130 individuals) and lowest (68 individuals) in April. Meiofauna mean biomass per $100\;cm^{-2}$ was $3.80-75.26{\mu}gC$ from each station, with the monthly mean biomass being lowest in April ($11.97{\mu}gC$) and highest in October ($39.50{\mu}gC$). The highest biomass was recorded at station five in October ($75.26{\mu}gC$). Eleven families of harpacticoid copepods occurred Ameiridae and Ectinosomatidae were the most frequent. The mean diversity index was 1.21 from all the stations, 1.22 from the sand mining stations, and 1.19 from the reference stations. The nematode:copepod (N/C) ratio was 1.57 from the sand mining stations and 1.37 from the reference stations. Non-metric multidimensional scaling analysis divided the community into group A (station one, non-sand mining and reference area) and groups B and C in the sand mining area. The present study reports similar numbers of taxa but lower density and biomass of meiofauna compared to previous studies in Korean waters. The variability of the diversity index and N/C ratio may indicate large fluctuation of meiofauna depending on temporal and spatial conditions of the environment in the study area.

Novel splice isoforms of pig myoneurin and their diverse mRNA expression patterns

  • Guo, Xiaohong;Li, Meng;Gao, Pengfei;Cao, Guoqing;Cheng, Zhimin;Zhang, Wanfeng;Liu, Jianfeng;Liu, Xiaojun;Li, Bugao
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.31 no.10
    • /
    • pp.1581-1590
    • /
    • 2018
  • Objective: The aim of this study was to clone alternative splicing isoforms of pig myoneurin (MYNN), predict the structure and function of coding protein, and study temporal and spatial expression characteristics of each transcript. Methods: Alternative splice isoforms of MYNN were identified using RNA sequencing (RNA-seq) and cloning techniques. Quantitative real-time polymerase chain reaction (qPCR) was employed to detect expression patterns in 11 tissues of Large White (LW) and Mashen (MS) pigs, and to study developmental expression patterns in cerebellum (CE), stomach (ST), and longissimus dorsi (LD). Results: The results showed that MYNN had two alternatively spliced isoforms, MYNN-1 (GenBank accession number: KY470829) and MYNN-2 (GenBank accession number: KY670835). MYNN-1 coding sequence (CDS) is composed of 1,830 bp encoding 609 AA, whereas MYNN-2 CDS is composed of 1,746 bp encoding 581 AA. MYNN-2 was 84 bp less than MYNN-1 and lacked the sixth exon. MYNN-2 was found to have one $C_2H_2$ type zinc finger protein domain less than MYNN-1. Two variants were ubiquitously expressed in all pig tissues, and there were significant differences in expression of different tissues (p<0.05; p<0.01). The expression of MYNN-1 was significantly higher than that of MYNN-2 in almost tissues (p<0.05; p<0.01), which testified that MYNN-1 is the main variant. The expression of two isoforms decreased gradually with increase of age in ST and CE of MS pig, whereas increased gradually in LW pig. In LD, the expression of two isoforms increased first and then decreased with increase of age in MS pig, and decreased gradually in LW pig. Conclusion: Two transcripts of pig MYNN were successfully cloned and MYNN-1 was main variant. MYNN was highly expressed in ST, CE, and LD, and their expression was regular. We speculated that MYNN plays important roles in digestion/absorption and skeletal muscle growth, whereas the specific mechanisms require further elucidation.

A Study on the Characteristics and Identity of Public Art in Historical and Cultural Areas - Focused on Taoxichuan in Jingdezhen - (역사문화지구의 퍼블릭 아트에서 나타나는 표현 특성과 아이덴티티 연구 - 징더전 시 도계천을 중심으로 -)

  • Li, JianHua;Yoon, Ji-Young
    • The Journal of the Korea Contents Association
    • /
    • v.20 no.2
    • /
    • pp.82-95
    • /
    • 2020
  • This study takes the identity and characteristics of public art in historical and cultural regions as the research object. Through the theoretical investigation and research on the public art of historical and cultural regions, six evaluation factors that shape spatial identity and characteristics were drawn: Environmental characteristics, public characteristics; Symbolic characteristics; Artistic characteristics;.Historical characteristics; Interactivity. The identity and characteristics of Taoxichuan public art in Jingdezhen was analyzed and evaluated. The results show that the " public art " of seven large chimneys is consistent with the historical structure of the industry. Among them, environmental, public characteristics, symbolic, artistic and historical characteristics of the Industria park have a high degree of preservation value and can be recognized as the historical landmark of the park. In the new public art, the artistic quality of public art, the environment, and the public characteristic of public art, are also at a moderate level, but it is comparatively weak. Public art recreated as an industrial heritage has formed an identity that can communicate spiritual sympathy to the public by forming a time-space communication between the public with historical relics and ceramic elements, and the new public art for local rehabilitation has given new artistic flavor to the city, but the new identity has not been shown.

Morphological Interpretation of the Transformation Process of Urban Form in Gosan-Up (형태학적 개념을 활용한 조선시대 고산현의 도시형태 변천과정 해석)

  • Lee, Kyung-Chan;Kang, In-Ae
    • Journal of the Korean Institute of Traditional Landscape Architecture
    • /
    • v.32 no.4
    • /
    • pp.37-49
    • /
    • 2014
  • This paper aims to interpret the transformation process of town plan of Gosan-up(高山), which was provincial administrative focus town in Josun dynasty, basing on morphological viewpoint. Morphological concepts, such as morphological frame, urban plan, kernel, colonization, route system, fixation line, fringe belt, plan unit & plan division, morphological period derived from the study of Conzen, M.R.G. and Caniggia, G. epidome district, break point, broken plot, urban fallow, privatization are adopted for the interpretation of urban form. Morphological period of Gosan can be divided in four ; formation of kernel & morphological structure, disintegration & redevelopment of the kernel, augmentative development of the kernel & formation of modern epidome district, outwards expanding of urbanized area, transition & reorganization of epidome district. Especially public leading projects such as construction of new regional connection road and public facilities such as myeon(township) office, agricultural cooperatives federation office, market, are main factors of morphological transformation of townplan. In the early stage, under the Japanese imperialism, construction of the new matrix route(Gosan-ro) through the kernel and followed planned routes gave way to disintegrating traditional areal plan unit and forming small block plan units in administrative facilities area. And linear plan units with commercial buildings were formed along the new matrix route and planned route adjacent to periodical market. In the latter stage, with development of public facilities, private sectors' large circulation institution and terminal outside the kernel with planned routes formed areal block based plan units with commercial and public buildings. And part of the spatial area with the linear plan unit were turned into urban fallow. With the transformation of town plan, new roads outside the kernel have substituted for traditional fixation line of waterway with road and topographical feature. Fringe belts were made successively along the new road and around the major intersections outside of existing urbanized area. Land use in fringe belts, constituting of outer locational tendency early on formation, was gradually replaced with commercial & business buildings.

Chronological Analysis on the Accessibility Change of Outdoor Space in Apartment Complexes in Cheonan City Using Space Syntax (공간구문론을 활용한 천안시 아파트단지 외부공간의 시기별 접근성 변화 분석)

  • Lee, Ki-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.18 no.12
    • /
    • pp.32-41
    • /
    • 2017
  • This study examined the arrangement attribute of each component based on the relationship among the components using space syntax at the entire complex level when analyzing the outdoor space of an apartment complex in Cheonan and as a preliminary study. The accessibility change in the access space to each space and to the facilities were examined based on a resident walking in the perspective that the outdoor spaces of the apartment complex are one spatial structure connected together. The space was divided into a total of 5 periods and the access space to the facilities and spaces located in outdoor space of the apartment complex were established as the unit space. In this study, a total of 6 analysis items were established: main complex access space, main building access space, shopping mall within complex, control office/center for senior citizens, children's playground, and resident sports facilities. In the analysis, the following conclusion was obtained. First, the accessibility to the main complex access space was high over almost all periods and the main building access space generally showed low accessibility. Second, the shopping mall showed a tendency that the closer the period, the more the accessibility is increased. Third, the control office/center for senior citizens, which can be considered as a common resident space and the children's playground out of the resident sports facilities, showed an exceptional tendency, the integration order was constantly high without a large change by the period and the control office/center for senior citizens showed the tendency for a high integration order, indicating that it is planned mainly in a location with good accessibility.