• 제목/요약/키워드: natural period

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현대건축에서 나타나는 중정의 유형 변화에 관한 연구 (A Study on the Typological Alteration of the Courtyard in Modern Architecture)

  • 이정민;김국선;우현용
    • 한국실내디자인학회논문집
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    • 제21권4호
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    • pp.40-47
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    • 2012
  • Courtyard is evolving from the conventional one element of a building far beyond into independent peremeter of urban architecture, of which function has been darmatically upgraded from embedded traditional air fluiding, nutural lighting system into where full fledged function can be experienced so much as your imagimation reaches taking major social responsibility such as intact offline social networking which links people from neighbors, inter / extra buiding openness which allow people can communicate among othewise between themselves and artificial natural environmental emelents supplier where people resort to relaxation and natural healing. Roles of courtyard has been by far streatched out into nearby natural healing space where people can shake off their unavoidable stresses from the modern life relaxing themselves looking at the sky otherwise observe natural surroundigns such as plants, flowers and waters. Thanks to hereonto mentioned its merits, Courtyard building is widely used and seen as a center of modern urban design in residence, public bilding and urban planned buildings. Courtyard biulding is nowadays boasting their morphological diversity brought out from lots of topological variation, type variants, cross section and inter relationship with the other neighboring spaces. Hence, hereby I have been studied how above mentioned three major peremeters of courtyard has been upgraded in modern architecture comparing the period from 1960 to 1990 and the period starting from 1991.

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Research on Relationship between Natural Vibration Periods and Structural Heights for High-rise Buildings and Its Reference Range in China

  • Xu, Peifu;Xiao, Congzhen;Li, Jianhui
    • 국제초고층학회논문집
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    • 제3권1호
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    • pp.49-64
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    • 2014
  • Natural vibration period is an important parameter for high-rise building, Based on 414 high-rise buildings completed or passed over-limit approval in China, the distribution law of natural vibration periods is analyzied. In order to satisfy the design requirements, such as global stability, story drift limit and minimum shear-gravity ratio, the reference ranges of fundamental periods $T_1$ are $0.3{\sqrt{H}}{\sim}0.4{\sqrt{H}}$ when the structural heights $H{\geq}250m$, when 150 m ${\leq}$ H < 250m, $T_1=0.25{\sqrt{H}}{\sim}0.4{\sqrt{H}}$, when 100 m ${\leq}$ H < 150 m, $T_1=0.2{\sqrt{H}}{\sim}0.35{\sqrt{H}}$, when 50 m $ {\leq}$ H < 100m, $T_1=0.15{\sqrt{H}}{\sim}0.3{\sqrt{H}}$. These can provide reference data for controlling mass and rigidity of high-rise buildings.

Extreme drought analysis using Natural drought index and Gi∗ statistic

  • Tuong, Vo Quang;So, Jae-Min;Bae, Deg-Hyo
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2020년도 학술발표회
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    • pp.124-124
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    • 2020
  • This study proposes a framework to evaluate extreme drought using the natural drought index and hot spot analysis. The study area was South Korea. Data were used from 59 automatic synoptic observing system stations. The variable infiltration capacity model was used for the period from 1981 to 2016. The natural drought index was constructed from precipitation, runoff and soil moisture data, which reflect the water cycle. The average interval, duration and severity of extreme drought events were determined following Run theory. The most extreme drought period occurred in 2014-2016, with 46 of 59 weather stations exhibition drought conditions and 78% exhibition extreme drought conditions. The Inje and Seosan station exhibited the longest drought duration of 6 months, and the most severe drought was 5 times higher than the extreme drought severity threshold. The hot spot analysis was used to explore the extreme drought conditions and showed an increasing trend in the middle and northeastern parts of South Korea. Overall, this study provides water resource managers with essential information about locations and significant trends of extreme drought.

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Exploring the factors responsible for variation in streamflow using different Budyko-base functions

  • Shah, Sabab Ali;Jehanzaib, Muhammad;Kim, Min Ji;Kim, Tae-Woong
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2022년도 학술발표회
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    • pp.140-140
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    • 2022
  • Recently an accurate quantification of streamflow under various climatological and anthropogenic factors and separation of their relative contribution remains challenging, because variation in streamflow may result in hydrological disasters. In this study, we evaluated the factors responsible for variation in streamflow in Korean watersheds, quantified separately their contribution using different Budyko-based functions, and identified hydrological breakpoint points. After detecting that the hydrological break point in 1995 and time series were divided into natural period (1966-1995), and disturbed period (1996-2014). During the natural period variation in climate tended to increase change in streamflow. However, in the disturbed period both climate variation and anthropogenic activities tended to increase streamflow variation in the watershed. Subsequently, the findings acquired from different Budyko-based functions were observed sensitive to selection of function. The variation in streamflow was observed in the response of change in climatic parameters ranging 46 to 75% (average 60%). The effects of anthropogenic activities were observed less compared to climate variation accounts 25 to 54% (average 40%). Furthermore, the relative contribution was observed to be sensitive corresponding to Budyko-based functions utilized. Moreover, relative impacts of both factors have capability to enhance uncertainty in the management of water resources. Thus, this knowledge would be essential for the implementation of water management spatial and temporal scale to reduce the risk of hydrological disasters in the watershed.

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강의실 CO2 발생률과 자연환기 특성의 측정 및 CFD 분석 (Measurements and CFD Analysis for Release Rate of CO2 and Characteristics of Natural Ventilation in Lecture Room)

  • 이동해;최영보
    • 한국안전학회지
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    • 제36권1호
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    • pp.86-94
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    • 2021
  • Lecture rooms are crowded with many attendees. Moreover, they rely significantly on the natural ventilation through windows for removing and controlling indoor contaminants such as CO2. With the aim of broadening the understanding of the characteristics of natural ventilation phenomena in lecture rooms, the average individual CO2 release rates of attendees were measured during the course of a lecture and compared with previously reported CO2 release rates. In addition, the effects of natural ventilation through windows on the time-variant CO2 concentrations in the center of the lecture room were measured and analyzed. Moreover, details about the overall and regional CO2 concentrations, as well as the air flows in the lecture room, were simulated and analyzed with computational fluid dynamics software, Fluent 2020 R2. It was found that the average individual CO2 release rates were slightly slower than previously reported rates. The local CO2 concentrations in the lecture room for regions with a high density of attendees increased over a short period of time, although the natural ventilation was already started by opening the windows. The overall CO2 concentration in the lecture room rapidly decreased in the early stage of ventilation, but declined very slowly after a longer period of ventilation time. Therefore, in order to enhance the efficiency of a lecture room's natural ventilation, it is recommended to homogeneously distribute the attendees in the lecture room, and to frequently open the windows for short periods of time.

Ecophysiology of the kleptoplastidic dinoflagellate Shimiella gracilenta: I. spatiotemporal distribution in Korean coastal waters and growth and ingestion rates

  • Ok, Jin Hee;Jeong, Hae Jin;Kang, Hee Chang;Park, Sang Ah;Eom, Se Hee;You, Ji Hyun;Lee, Sung Yeon
    • ALGAE
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    • 제36권4호
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    • pp.263-283
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    • 2021
  • To explore the ecophysiological characteristics of the kleptoplastidic dinoflagellate Shimiella gracilenta, we determined its spatiotemporal distribution in Korean coastal waters and growth and ingestion rates as a function of prey concentration. The abundance of S. gracilenta at 28 stations from 2015 to 2018 was measured using quantitative real-time polymerase chain reaction. Cells of S. gracilenta were detected at least once at all the stations and in each season, when temperature and salinity were 1.7-26.4℃ and 9.9-35.6, respectively. Moreover, among the 28 potential prey species tested, S. gracilenta SGJH1904 fed on diverse prey taxa. However, the highest abundance of S. gracilenta was only 3 cells mL-1 during the study period. The threshold Teleaulax amphioxeia concentration for S. gracilenta growth was 5,618 cells mL-1, which was much higher than the highest abundance of T. amphioxeia (667 cells mL-1). Thus, T. amphioxeia was not likely to support the growth of S. gracilenta in the field during the study period. However, the maximum specific growth and ingestion rates of S. gracilenta on T. amphioxeia, the optimal prey species, were 1.36 d-1 and 0.04 ng C predator-1 d-1, respectively. Thus, if the abundance of T. amphioxeia was much higher than 5,618 cells mL-1, the abundance of S. gracilenta could be much higher than the highest abundance observed in this study. Eurythermal and euryhaline characteristics of S. gracilenta and its ability to feed on diverse prey species and conduct kleptoplastidy are likely to be responsible for its common spatiotemporal distribution.

Protists in hypoxic waters of Jinhae Bay and Masan Bay, Korea, based on metabarcoding analyses: emphasizing surviving dinoflagellates

  • Jin Hee Ok;Hae Jin Jeong;Hee Chang Kang;Ji Hyun You;Sang Ah Park;Se Hee Eom;Jin Kyeong Kang;Yeong Du Yoo
    • ALGAE
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    • 제38권4호
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    • pp.265-281
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    • 2023
  • Hypoxia can indeed impact the survival of protists, which play a crucial role in marine ecosystems. To better understand the protistan community structure and species that can thrive in hypoxic waters, we collected samples from both the surface and bottom waters during the hypoxic period in Jinhae and Masan Bays and the non-hypoxic period in Jinhae Bay. Subsequently, we utilized metabarcoding techniques to identify the protistan species. During hypoxia, with dissolved oxygen concentrations of 0.8 mg L-1 in Jinhae Bay and 1.8 mg L-1 in Masan Bay within the bottom waters, the phylum Dinoflagellata exhibited the highest amplicon sequence variants richness among the identified protist phyla. Following the Dinoflagellata, Ochrophyta and Ciliophora also displayed notable presence. In hypoxic waters of Jinhae and Masan Bays, we identified a total of 36 dinoflagellate species that exhibited various trophic modes. These included one autotrophic species, 14 mixotrophic species, 9 phototrophic species with undetermined trophic modes (either autotrophic or mixotrophic), 2 kleptoplastidic species, and 10 heterotrophic species. Furthermore, the hypoxic bottom water exhibited a greater number of heterotrophic dinoflagellate species compared to the non-hypoxic surface water within the same water column or the non-hypoxic bottom water. Therefore, feeding by mixotrophic and heterotrophic dinoflagellates may be partially responsible for their dominance in terms of the number of species surviving in hypoxic waters. This study not only introduces the initial documentation of 26 dinoflagellate species surviving in hypoxic conditions but also establishes a foundation for a more comprehensive understanding of the ecophysiology of dinoflagellates in hypoxic marine environments.

NEGATIVE INDES를 이용한 교합면 복제에 관한 연구 (A STUDY OF DUPLICATING OCCLUSAL CONTOUR USING NEGATIVE INDEX)

  • 장완식
    • 대한치과의사협회지
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    • 제19권2호통권141호
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    • pp.159-162
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    • 1981
  • The author devised a simple technique for duplicating occlusal contour of natural teeth on the prepared abutments using hard stone index obtained from the study cast of natural teeth. Throughout this author devised method, the following advantages are studied. Firstly the dentist can obtain an ideal occlusal wax patterns which have arrived at the physiologic state through a long period of adjustment to various habits and functional movements. Secondly the construction procedure is simple, and thirdly it is easy to adjust wax pattern of nomal natural teeth which duplication is required.

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거주지역의 정주성 향상을 위한 연구 (I) - 미래 주거생활주기에 따른 대구지역 대학생의 지역선호와 가치를 중심으로 - (A Study for the Elevation of Settlement in Residential District(I))

  • 임소연;김재경;안옥희
    • 한국주거학회논문집
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    • 제10권4호
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    • pp.1-10
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    • 1999
  • The purpose of this study was to investigate the environmental factors having a influence on the preference of residential district and to furnish basic information for the successful settlement. For the purpose, residential preference and values on the residential district were estimated according to the housing life cycle. Data were collected through questionnaires designed for this study, and the objects of this research were university students. To analyze the data were used spsswin program. The major results were as follows. 1. According to the housing life cycle, there were significant differences in the preference of the residential district, living area and housing type in the future. Metropolitan and seoul, residential area and commercial area, apartment, office-hotel and row house were preferred in the housing formative. In the stable period, seoul and metropolitan, tower apartment, residential area were preferred. But in the housing reductive period, they preferred a green zone in the rural, the detached house. 2. The degree of consideration of living convenience facilities was high in the housing formative period. Both education-leisure, business facilities and marketing facilities were highly valuated in the housing stable period. But the value of welfare facilities was high in the housing reductive period. 3. The 4 dimensions of values in environmental conditions were extracted through factor analysis. They were natural, human, social, and economic factors. According to the housing life cycle, there were significant differences in factors being considered as the environmental conditions. The values of human and economic factors were high in the housing formative and stable period. Natural factor were highly considered in the housing reductive period.

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