• Title/Summary/Keyword: habitat density

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Complex Power: An Analytical Approach to Measuring the Degree of Urbanity of Urban Building Complexes

  • Xu, Shuchen;Ye, Yu;Xu, Leiqing
    • International Journal of High-Rise Buildings
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    • v.6 no.2
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    • pp.165-175
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    • 2017
  • The importance of designing urban building complexes so that they obtain 'urban' power, rather than become isolated from the surrounding urban context, has been well recognized by both researchers and practitioners. Nevertheless, most current discussions are made from architects' personal experiences and intuition, and lack a quantitative understanding, to which obstacles include an in-depth exploration of the 'urban' power between building complexes and the urban environment. This paper attempts to measure this feature of 'urban', i.e., 'urbanity,' through a new analytical approach derived from the opendata environment. Three measurements that can be easily collected though the Google Maps API and Open Street Map are applied herein to evaluate high or low values of urbanity. Specifically, these are 'metric depth', i.e., the scale of extended public space, 'development density', i.e., density and distribution of point of interests (POIs), and 'type diversity', i.e., diversity of different commercial types. Six cases located in Japan, China and Hong Kong respectively are ranked based on this analytical approach and compared with each other. It shows that Japanese cases, i.e., Osaka Station City and Namba Parks, Osaka, obtained clearly higher values than cases in Shanghai and Hong Kong. On one hand, the insight generated from measuring and explaining 'urban' power would help to assist better implementation of this feature in the design of urban building complexes. On the other hand, this analytical approach can be easily extended to achieve a large-scale measurement and comparison among different urban building complexes, which is also helpful for design practitioners.

An Efficient Routing Scheme Based on Node Density for Underwater Acoustic Sensors Networks

  • Rooh Ullah;Beenish Ayesha Akram;Amna Zafar;Atif Saeed;Sultan H. Almotiri;Mohammed A. Al Ghamdi
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.18 no.5
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    • pp.1390-1411
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    • 2024
  • Underwater Wireless Sensors Networks (UWSNs) are deployed in remotely monitored environment such as water level monitoring, ocean current identification, oil detection, habitat monitoring and numerous military applications. Providing scalable and efficient routing is very challenging in UWSNs due to the harsh underwater environment. The biggest difficulties are the nodes inherent movement due to water current, long delay in data transmission, low bandwidth of the acoustic signal, high error rate and energy scarcity in battery powered nodes. Many routing protocols have been proposed to solve the aforementioned problems. There are three broad categories of routing protocols namely depth based, energy based and vector-based routing. Vector Based Forwarding protocols perform routing through virtual pipeline by defining their radius which give proper direction to packets communication. We proposed a routing protocol termed as Path-Oriented Energy Scaled Expanded Vector Based Forwarding (PESEVBF). PESEVBF takes into account all parameters; holding time, the source nodes packets routing path and void holes creation on the second hop; PESEVBF not only considers the packet upward advancement but also focus on density of the forwarded nodes in terms of number of potential forwarding and suppressed nodes for path selection. Node selection in resultant holding time is based on minimum Path Factor (PF) value. Moreover, the suppressed node will be selected for packet forwarding to avoid the void holes occurrences on the second hop. Performance of PESEVBF is compared with other routing protocols using matrices such as energy consumption, packet delivery ratio, packets dropping ratio and duplicate packets creation indicating considerable performance improvement.

Differences in Breeding Bird Communities Between Deciduous Forests of Gwangneung and Mt. Namsan Areas

  • Rhim, Shin-Jae;Kim, Min-Jin;Lee, Ju-Young;Kang, Jeong-Hoon
    • Journal of Korean Society of Forest Science
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    • v.96 no.5
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    • pp.567-571
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    • 2007
  • This study was conducted to clarify the differences in breeding bird communities between deciduous forests of Gwangneung and Mt. Namsan areas from April to August 2006. Two 10ha area were selected for territory mapping of breeding bird community in both study area. The DBH distribution of trees and average foliage profiles were significantly different between study areas. Also, breeding bird communities were different. Number of breeding species and pairs, breeding density, and bird species diversity were higher in Gwangneung area than in Mt. Namsan area. When examining relationship between forest habitat structure and bird community, Number of bird species and breeding pairs belonged to hole and canopy guild were increase as the increase of coverstory coverage and number of large trees. Therefore, it is necessary to make vertical structure more various to plant bushes, and to make DBH distribution more diverse for enhancing bird species diversity in the degraded ecosystem.

Glochidial attachment and cyst formation on the fish (석패과 유생의 어체부착과 어류의 피낭형성)

  • Song, Ho-Bok;Kwon, Oh-Kil
    • Korean Journal of Ichthyology
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    • v.6 no.1
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    • pp.51-59
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    • 1994
  • Morphology of glochidia of two species of Unionidae mussels, Unio douglasiae and Anodonta woodiana were studied based on SEM, and their attachment on Acheilognathus yamatsutae(Acheilognathinae) was observed in the experimentally infected fishes. The glochidia were round-triangle in shape and possessed larval threads, hooks, hooklets, and sensory hairs. Glochidal attachment and cyst formation of the fish were observed without regard to feeding habit and habitat. Density of glochida on the fish (Acheilognathus yamatsutae) was in the order of pectoral fin, dorsal fin, gill and caudal fin. The host fish became encysted about 5-10 hours to the glochidia, and the glochidia detached about 5-6 days after attachment at water temperature $26{\pm}1^{\circ}C$.

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Distribution and attachment characteristics of Sida crystallina (O.F. Müller, 1776) in lentic freshwater ecosystems of South Korea

  • Choi, Jong-Yun;Jeong, Kwang-Seuk;Kim, Seong-Ki;Son, Se-Hwan;Joo, Gea-Jae
    • Journal of Ecology and Environment
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    • v.40 no.1
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    • pp.45-54
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    • 2016
  • Background: Macrophytes are commonly utilised as habitat by epiphytic species; thus, complex macrophyte structures can support high diversities and abundances of epiphytic species. We tested the hypothesis that the presence of aquatic macrophytes is an important factor determining Sida crystallina (O.F. Muller, 1776) distribution. Results: An ecological survey was conducted in 147 lentic freshwater bodies. S. crystallina was frequently observed, and its density was strongly associated with macrophyte abundance. S. crystallina was found on emergent plant species such as Phragmites australis and Paspalum distichum, attached to the stem surfaces by adhesive substances secreted by the nuchal organ. Thus, S. crystallina was more strongly attached to macrophytes than to other epiphytic cladoceran species. We found higher densities of S. crystallina in filtered water with increased macrophyte shaking effort (i.e. 10, 20, 40, or 80 times). S. crystallina attachment was not related to fish predation. Stable isotope analysis showed that S. crystallina utilises epiphytic organic matter (EOM) on macrophytes as a food source. Conclusions: Consequently, S. crystallina seems to have a strong association with species-specific macrophyte biomass than with other cladoceran species, which may contribute to this species' predominance in various freshwater ecosystems where macrophytes are abundant.

Meiobenthic Community Structures on the Sediment of Seagrass Bed and Mangrove Forest in Chunk Lagoon, Micronesia (마이크로네시아 연방 축 라군의 해초지와 맹그로브 군락 퇴적물에 서식하는 중형저서동물 군집 특성)

  • Min, Won-Gi;Kim, Dong-Sung;Kwon, Moon-Sang
    • Ocean and Polar Research
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    • v.28 no.1
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    • pp.13-23
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    • 2006
  • This study was conducted to investigate the community structure and distributional pattern of meiobenthos on the sediment of the mangrove forest and seagrass bed in the Chuuk lagoon. The samples were collected by an acryl corer at 14 stations. Nematodes were the most abundant meiobenthos, followed by ciliophorans and polychaetes; these taxa comprised more than 70% of the total abundance at all stations. The meiofuuna sampled in seagrass bed were more diverse than those of mangrove substrates. Total densities were higher in mangrove stations than other sites, averaging 1,671 to $2,967inds/10cm^2$. Densities in seagrass area ranged between 605 and $1,053inds/10cm^2$. Biomasses, however, were higher in seagrass bed $(975-2,167{\mu}g\;free\;dry\;weight/10cm^2)$ than in mangrove area $(1,064-1,180{\mu}g\;free\;dry\;weight/10cm^2)$. Ordination chart by MDS of major meiofaunal density in each station showed difference between mangrove area and seagrass area in terms of habitat of meiobenthos.

Preference of adult top shell (Batillus cornutus) on specific marine algae in the coastal waters of Jeju Island (제주도산 소라 (Batillus cornutus) 성패의 특정 해조류에 대한 선호도)

  • Yoo, Joon-Taek;Oh, Bong-Se;Chang, Dae-Soo
    • The Korean Journal of Malacology
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    • v.27 no.4
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    • pp.299-306
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    • 2011
  • This paper examines relation between growth of adult top shell and their selectivity over different marine algae. For the study the top shell density and the algal species in different depth were surveyed by SCUBA. To test selectivity over different types of algae, five algal species including Ecklonia cava, Undaria pinnatifida, Ulva spp, Gelidium amansii and Sargassum spp were provided to top shells in indoor water tank condition. In the field survey, the wet weight of Ecklonia cava was significantly (r = 0.612, p < 0.05) correlated to the shell length (SL) of top shell. In the indoor water tank experiment conducted over 12 hours after sunrise, adult top shell (SL > SL 4.5 cm) tended to select Ecklonia cava and Undaria pinnatifida, which are common and abundant algal in the subtidal waters in Jeju Island. Our field survey and the indoor experiment suggest that E. cava and U. pinnatifida could be food preferred by adult top shell in its habitat.

Differences in Density and Body Condition of Small Rodent Populations on Different Distance from Road

  • Hur, Wee-Haeng;Lee, Woo-Shin;Choi, Chang-Yong;Park, Young-Su;Lee, Chang-Bae;Rhim, Shin-Jae
    • Journal of Korean Society of Forest Science
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    • v.94 no.2 s.159
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    • pp.108-111
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    • 2005
  • This study was conducted to identify the road effect on small rodent populations within fragmented forest areas around the road from June to September 2002, in 9 study sites of Baekdugdaegan mountains, Korea. Two species of small rodents, Korean field mouse Apodemus peninsulae and striped field mouse Apodemus agrarius, were captured in this study. Korean field mouse preferred forest area, and striped field mouse generally has been found edge area around road. Mean body weight of Korean field mouse was significantly different, but that of striped field mouse was not between both distance from road. Korean field mouse is forest-dwelling species and their distribution is limited in forest area. In contrast, striped field mouse has wide distributional range around road. The effects of road is different in each small rodent species and their habitat preferences.

Bird Communities in Rice Field and Grasslands during the Dry Season in the Mekong Delta, Cambodia

  • Kry, Msphal;Lee, Woo-Shin;Park, Sung Jin;Rhim, Shin-Jae
    • Journal of Korean Society of Forest Science
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    • v.98 no.2
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    • pp.197-202
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    • 2009
  • We studied bird communities among in rice field (46 plots), short grallland (47plot), and tall grass mixed shrub (21 plots) during dry season, January 2007 in Boeung Prek Lapouv (BPL) Important Bird Area, Mekong Delta, Cambodia using the point-count method. Water depth, vegetation height and shrub density were significantly different among the three study areas. We recorded, 60 bird species, of which 13 differed significantly among habitats. Landbirds such as Grey-breasted Prinia (Prinia hodgsonii) and Oliver-black Sunbird (Nectarinia jugularis) were much more abundant (P<0.0001) in the tall grass mixed shrub, whereas the Sarus Crane (Grus antigone), herons and egrets were more abundant in the short grass (P<0.05). Bird species richness and species abundances were not significantly different among habitats. Bird species diversity (H') was higher in grasslands than in rice fields. Mosaic habitat matrix, such as rice field, short grass, and tall grass mixed shrub, should be maintained for the extend and quality of wetlands, and the prevailing human-land use patterns, appear adequate and conductive for waterbirds in the Mekong Delta, Cambodia.

Monitoring of Fish Aggregations Responding to Artificial Reefs Using a Split-beam Echo Sounder, Side-scan Sonar, and an Underwater CCTV Camera System at Suyeong Man, Busan, Korea (소너 및 수중 CCTV 카메라 시스템을 이용한 수영만 인공어초 주변에 군집한 어군의 모니터링)

  • Lee, Dae-Jae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.46 no.3
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    • pp.266-272
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    • 2013
  • The objective of this study was to monitor and evaluate the schooling characteristics, including the distribution density (volume backscattering strength) and acoustic size (target strength), of commercially valuable species swimming in response to artificial reefs installed at Suyeong Man, Busan, Korea. Fish aggregations at two artificial reef areas and at a nearby natural rocky reef habitat were recorded and analyzed using a 70 kHz split-beam echo sounder and 330 kHz side-scan sonar from August to September, 2006. An underwater CCTV camera system was also used to observe marine organisms in physical contact with and swimming very close to artificial reefs. During the acoustic observations at three reef sites, useful information about schooling characteristics of fish aggregations responding to artificial reefs were obtained, but more trials are needed to confirm significant differences in schooling behavior and geographical distributions in areas containing natural reef structures and artificial reefs.