• Title/Summary/Keyword: spatio-temporal trend

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The Spatio-temporal Distribution of Zooplankton Communities in the Northern Yellow Sea During Autumn and Winter (가을-겨울철 황해 북부의 동물플랑크톤 시공분포 특성)

  • Lim, Dong-Hyun;Yoon, Won-Duk;Yang, Joon-Yong;Lee, Yoon
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.15 no.4
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    • pp.339-344
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    • 2009
  • The joint cruises of six times between Korea and China were carried out for a better understanding of the environmental and oceanographical characteristics of the Yellow Sea for 6 years from 1998 to 2003. Zooplankton samples were collected one time per year at 24 stations on 3 lines of the Yellow Sea. The aim of this study is to understand the seasonal fluctuation of zooplankton community in the Yellow Sea. There is no trend on the spatio-temporal distribution of zooplankton. Copepoda, the major taxon of the Yellow Sea, was high in distribution in the eastern part and Chaetognatha in the western part of the Yellow Sea. In this results, the dominant copepods were Calanus sinicus, Paracalanus parvus s.l., Oithona atlantica, and Corycaeus affinis during the study periods. The density fluctuation of these dominant species may be an important factor in determining the fisheries resource of the Yellow Sea.

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Ecology and Natural History of North Korean Pinaceae (북한 소나무과 나무의 생태와 자연사)

  • Kong, Woo-Seok
    • Journal of Environmental Impact Assessment
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    • v.15 no.5
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    • pp.323-337
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    • 2006
  • This work discussed the species composition, phylogeny, spatio-temporal distribution, ecology and natural history of North Korean Pinaceae or pine tree family, which seems to be important to maintain nature and ecosystem in the Korean Peninsula. Out of five genera and sixteen species of Pinaceae of the Korean Peninsula, North Korea contains four genera and eleven species of Pinaceae, including Pinus densilflora, P. koraiensis, P. pumila, Picea jezoensis, P. koraiensis, P. koraiensis var. koraiensis, P. pungsanensis, Larix gmelini, L. gmelinii var. olgensis, Abies holophylla and A. nephrolepis. In terms of phylogeny Pinus is closely related to Picea, and followed by Larix. Abies is close to Tsuga which only occur at Ullung Island. Distributional pattern of North Korean Pinaceae can be classified into four types; three species of nation-wide montane type i.e., Pinus densilflora, P. koraiensis and Abies holophylla, four species of central and northern subalpine type, i.e., Pinus pumila, Picea koraiensis, Larix gmelini and Abies nephrolepis, one nation-wide subalpine type, Picea jezoensis, and three species disjunctive to north type, i.e., Picea koraiensis var. koraiensis, P. pungsanensis, and Larix gmelinii var. olgensis. Pinaceae species occurring on the alpine and subalpine belts of North Korea, such as Pinus koraiensis, P. pumila, Picea jezoensis, P. koraiensis, P. koraiensis var. koraiensis, P. pungsanensis, Larix gmelini, L. gmelinii var. olgensis and A. nephrolepis are considered as the glacial descendant from the boreal region. Those species might have migrated from the north during the Pleistocene glacial epochs in search of favourable condition, and since the Holocene period they survived on the hostile alpine and subalpine environments, in which they are more competitive than warmth-tolerant temperate vegetation. Certain species, such as Picea pungsanensis, is segregated on the isolated mountains since the Pleistocene period, and forced to adapt to local environment, and eventually became an endemic species of North Korea. Recent rapid global warming trend especially in northern high mountains of North Korea could cause an unfavourable environment for the survival of cold-tolerant Pinaceae of the alpine and subalpine belts. Pinus densiflora, which is occurring on the montane belt might faced with difficulties due to both the deforestation and the outbreak of insect-borne disease, such as Bursaphelenchus xylophilus.

The spatio-temporal expression analysis of parathyroid hormone like hormone gene provides a new insight for bone growth of the antler tip tissue in sika deer

  • Haihua Xing;Ruobing Han;Qianghui Wang;Zihui Sun;Heping Li
    • Animal Bioscience
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    • v.37 no.8
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    • pp.1367-1376
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    • 2024
  • Objective: Parathyroid hormone like hormone (PTHLH), as an essential factor for bone growth, is involved in a variety of physiological processes. The aim of this study was to explore the role of PTHLH gene in the growth of antlers. Methods: The coding sequence (CDS) of PTHLH gene cDNA was obtained by cloning in sika deer (Cervus nippon), and the bioinformatics was analyzed. The quantitative real-time polymerase chain reaction (qRT-PCR) was used to analyze the differences expression of PTHLH mRNA in different tissues of the antler tip at different growth periods (early period, EP; middle period, MP; late period, LP). Results: The CDS of PTHLH gene was 534 bp in length and encoded 177 amino acids. Predictive analysis results revealed that the PTHLH protein was a hydrophilic protein without transmembrane structure, with its secondary structure consisting mainly of random coil. The PTHLH protein of sika deer had the identity of 98.31%, 96.82%, 96.05%, and 94.92% with Cervus canadensis, Bos mutus, Oryx dammah and Budorcas taxicolor, which were highly conserved among the artiodactyls. The qRT-PCR results showed that PTHLH mRNA had a unique spatio-temporal expression pattern in antlers. In the dermis, precartilage, and cartilage tissues, the expression of PTHLH mRNA was extremely significantly higher in MP than in EP, LP (p<0.01). In the mesenchyme tissue, the expression of PTHLH mRNA in MP was significantly higher than that of EP (p<0.05), but extremely significantly lower than that of LP (p<0.01). The expression of PTHLH mRNA in antler tip tissues at all growth periods had approximately the same trend, that is, from distal to basal, it was first downregulated from the dermis to the mesenchyme and then continuously up-regulated to the cartilage tissue. Conclusion: PTHLH gene may promote the rapid growth of antler mainly through its extensive regulatory effect on the antler tip tissue.

A Suggestion for Spatiotemporal Analysis Model of Complaints on Officially Assessed Land Price by Big Data Mining (빅데이터 마이닝에 의한 공시지가 민원의 시공간적 분석모델 제시)

  • Cho, Tae In;Choi, Byoung Gil;Na, Young Woo;Moon, Young Seob;Kim, Se Hun
    • Journal of Cadastre & Land InformatiX
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    • v.48 no.2
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    • pp.79-98
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    • 2018
  • The purpose of this study is to suggest a model analysing spatio-temporal characteristics of the civil complaints for the officially assessed land price based on big data mining. Specifically, in this study, the underlying reasons for the civil complaints were found from the spatio-temporal perspectives, rather than the institutional factors, and a model was suggested monitoring a trend of the occurrence of such complaints. The official documents of 6,481 civil complaints for the officially assessed land price in the district of Jung-gu of Incheon Metropolitan City over the period from 2006 to 2015 along with their temporal and spatial poperties were collected and used for the analysis. Frequencies of major key words were examined by using a text mining method. Correlations among mafor key words were studied through the social network analysis. By calculating term frequency(TF) and term frequency-inverse document frequency(TF-IDF), which correspond to the weighted value of key words, I identified the major key words for the occurrence of the civil complaint for the officially assessed land price. Then the spatio-temporal characteristics of the civil complaints were examined by analysing hot spot based on the statistics of Getis-Ord $Gi^*$. It was found that the characteristic of civil complaints for the officially assessed land price were changing, forming a cluster that is linked spatio-temporally. Using text mining and social network analysis method, we could find out that the occurrence reason of civil complaints for the officially assessed land price could be identified quantitatively based on natural language. TF and TF-IDF, the weighted averages of key words, can be used as main explanatory variables to analyze spatio-temporal characteristics of civil complaints for the officially assessed land price since these statistics are different over time across different regions.

Statistical Analysis of the Spatio-temporal Water Quality Characteristics of the Nakdong River (낙동강수계 수질의 시·공간적 특성에 대한 통계학적 분석)

  • Seo, Mijin;Cho, Changdae;Im, Taehyo;Kim, Sanghun;Yoon, Hyunjeong;Kim, Yongseok;Kim, Gyeonghoon
    • Journal of Environmental Science International
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    • v.28 no.3
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    • pp.303-320
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    • 2019
  • Water quality is characterized by various complex factors. Therefore, a systematic understanding of water quality trends is required to carry out a proper evaluation. In this study, we analyzed the spatio-temporal water quality characteristics of the Nakdong River using five-year data from 2012 to 2016. Data was collected on the pH, DO, BOD, COD, SS, TN, TP, TOC, WT, EC, $NH_3-N$, $NO_3-N$, $PO_4-P$, Chl-a, rainfall, and total and fecal coliforms. A total of 38 water quality measurement stations, from Andong1 to Gupo, were considered. Statistical analyses including trend, cluster, and factor analyses were conducted to identify the dominant water quality components affecting the Nakdong River. The Nakdong River was spatially classified into three groups for up-stream (Andong1 to Sangju1), mid/up-stream (Donam to Dalseong), and mid/down-stream (Hwawonnaru to Gupo) data collection, and temporally into two groups for summer/fall (7~10), and the rest of the season (11~6) data. The water quality of the entire Nakdong River showed trends similar to the mid/down-stream section, which indicates the importance of water quality management in this section. Suspended solids, phosphorus, and coliform groups were established as important factors to be considered in the summer/fall season across the river, especially in the mid/down-stream section. Nitrogen and organic matter were identified as important factors to be considered in the rest of the season, especially in the mid/up-stream section. This study could help determine the water quality components that should be intensively monitored in the Nakdong River.

Continuous Multiple Prediction of Stream Data Based on Hierarchical Temporal Memory Network (계층형 시간적 메모리 네트워크를 기반으로 한 스트림 데이터의 연속 다중 예측)

  • Han, Chang-Yeong;Kim, Sung-Jin;Kang, Hyun-Syug
    • KIPS Transactions on Computer and Communication Systems
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    • v.1 no.1
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    • pp.11-20
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    • 2012
  • Stream data shows a sequence of values changing continuously over time. Due to the nature of stream data, its trend is continuously changing according to various time intervals. Therefore the prediction of stream data must be carried out simultaneously with respect to multiple intervals, i.e. Continuous Multiple Prediction(CMP). In this paper, we propose a Continuous Integrated Hierarchical Temporal Memory (CIHTM) network for CMP based on the Hierarchical Temporal Memory (HTM) model which is a neocortex leraning algorithm. To develop the CIHTM network, we created three kinds of new modules: Shift Vector Senor, Spatio-Temporal Classifier and Multiple Integrator. And also we developed learning and inferencing algorithm of CIHTM network.

An Empirical Study on the Estimation of Housing Sales Price using Spatiotemporal Autoregressive Model (시공간자기회귀(STAR)모형을 이용한 부동산 가격 추정에 관한 연구)

  • Chun, Hae Jung;Park, Heon Soo
    • Korea Real Estate Review
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    • v.24 no.1
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    • pp.7-14
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    • 2014
  • This study, as the temporal and spatial data for the real price apartment in Seoul from January 2006 to June 2013, empirically compared and analyzed the estimation result of apartment price using OLS by hedonic price model for the problem of space-time correlation, temporal autoregressive model (TAR) considering temporal effect, spatial autoregressive model (SAR) spatial effect and spatiotemporal autoregressive model (STAR) spatiotemporal effect. As a result, the adjusted R-square of STAR model was increased by 10% compared that of OLS model while the root mean squares error (RMSE) was decreased by 18%. Considering temporal and spatial effect, it is observed that the estimation of apartment price is more correct than the existing model. As the result of analyzing STAR model, the apartment price is affected as follows; area for apartment(-), years of apartment(-), dummy of low-rise(-), individual heating (-), city gas(-), dummy of reconstruction(+), stairs(+), size of complex(+). The results of other analysis method were the same. When estimating the price of real estate using STAR model, the government officials can improve policy efficiency and make reasonable investment based on the objective information by grasping trend of real estate market accurately.

Spatio temporal analysis of land subsidence due to declining groundwater levels in arid region of Pakistan using Sentinel-1 SAR imegery

  • Ahmad, Waqas;Kim, Dongkyun;Kim, Soohyun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2017.05a
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    • pp.192-192
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    • 2017
  • In this paper we showed the application of European Space Agency's C-band Sentinel-1 Synthetic Aperture Radar (SAR) imagery to identify land subsidence in a heavily groundwater pumping area. We used the repeat pass satellite interferometry method in combination with persistent scattering (PS) interferometric technique to generate and analyze twenty-eight interferograms for the period October 2014 to November 2016. The interferometry results show that land subsidence is more pronounced in the urban areas. Excessive groundwater pumping in the study area is believed to be the main reason for land subsidence. The results are compared with the subsidence rate measured by GPS as reported in other studies and with the mean change in total water storage field of GRACE solutions provided by the Jet Propulsion Laboratory (JPL), the German Research Centre for Geosciences (GFZ) and the Center for Space Research (CSR). The comparison shows persistently decreasing trends during the period of study. A strong reliance of the trend of land subsidence on the temporal decline in total water storage proposes that much of the land subsidence can be attributed to heavy pumping of the groundwater.

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Spatio-temporal Variation of Intertidal Microphytobenthos in the Nakdong Estuary

  • Du, Guoying;Chung, Ik-Kyo
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.12 no.3
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    • pp.186-190
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    • 2007
  • The species composition and the biomass of intertidal microphytobenthos (MPB) were investigated at four sites in the Nakdong Estuary from Feb. to Dec. 2006. The chlorophyll (chl) ${\alpha}$ concentration showed a positive correlation with MPB abundance, and depth profiles showed similar patterns: high at the surface, rapidly decreasing within 4 cm from the surface, and slowly decreasing thereafter. A MANOVA analysis revealed that the chl ${\alpha}$ concentration varied significantly not only with depth, month, and site, but also with combinations of these factors. Among the four investigated sites, site D (Baekhabdeung) showed a seasonal biomass variation trend distinct from those of the other sites: higher in summer, decreased in autumn and with sustained low values until winter. As indicated, the other sites contrastingly showed low biomasses in summer, after which the biomasses continuously increased, with some variation among the sites. A cluster analysis of species composition indicated that sites near to each other and with similar sediment structures had closer similarities in the same seasons. The species of genus Amphora and Navicula were dominant at the four sites throughout the study period.

Time trend of malaria in relation to climate variability in Papua New Guinea

  • Park, Jae-Won;Cheong, Hae-Kwan;Honda, Yasushi;Ha, Mina;Kim, Ho;Kolam, Joel;Inape, Kasis;Mueller, Ivo
    • Environmental Analysis Health and Toxicology
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    • v.31
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    • pp.3.1-3.11
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    • 2016
  • Objectives This study was conducted to describe the regional malaria incidence in relation to the geographic and climatic conditions and describe the effect of altitude on the expansion of malaria over the last decade in Papua New Guinea. Methods Malaria incidence was estimated in five provinces from 1996 to 2008 using national health surveillance data. Time trend of malaria incidence was compared with rainfall and minimum/maximum temperature. In the Eastern Highland Province, time trend of malaria incidence over the study period was stratified by altitude. Spatio-temporal pattern of malaria was analyzed. Results Nationwide, malaria incidence was stationary. Regionally, the incidence increased markedly in the highland region (292.0/100000/yr, p =0.021), and remained stationary in the other regions. Seasonality of the malaria incidence was related with rainfall. Decreasing incidence of malaria was associated with decreasing rainfall in the southern coastal region, whereas it was not evident in the northern coastal region. In the Eastern Highland Province, malaria incidence increased in areas below 1700 m, with the rate of increase being steeper at higher altitudes. Conclusions Increasing trend of malaria incidence was prominent in the highland region of Papua New Guinea, while long-term trend was dependent upon baseline level of rainfall in coastal regions.