• 제목/요약/키워드: historical change

검색결과 801건 처리시간 0.028초

수문학적 모의기법에 대한 연구 - 낙동강 왜관지점의 연유량과 월유량의 모의발생 및 비교 - (A Study of the hydrological generation - The generation and comparison with annual and monthly dicharge at Wacgwan in the Nakdong River)

  • 천덕진;최영박
    • 물과 미래
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    • 제13권1호
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    • pp.49-56
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    • 1980
  • The thesis of this analytical study includes 1) the generation of annual and monthly discharge regarding single hydrological variable at single site, 2)comparsion with the historical records and the generation, and 3) changing the monthly generatied discharge into annual. The conclusion of this will be used for the future plan for water resources development. Annual discharges at waegwan are characterized by log-normal distirbution and persistence-absent. Also, the random number generator causes the errors in the generation of annual discharge. The serial correlation coefficients of the generated annual discharge have less value than that of historical records, while the correlation coefficient and slope in January have(+) value and opposite to historical record. To change the monthly generated discharge into annual is not proper.

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온톨로지 버전 관리를 위한 변경 집합과 저장 기법 (Change Sets and Storage Polocies for Ontology Versions Management)

  • 윤홍원
    • 한국정보통신학회논문지
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    • 제8권6호
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    • pp.1257-1265
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    • 2004
  • 온톨리지는 시맨틱 웹의 핵심 요소이며 시간이 흐름에 따라서 변화하는 특징을 가지고 있다. 온톨리지에서 발생하는 변화는 도메인 변화, 개념 변화, 메타데이터 변화 등이 있다. 이 논문에서는 이들 변화와 시간차원을 기반으로 하는 변경 집합을 제안한다. 온톨리지 버전은 대량의 정보를 저장하고 관리해야 하는데 이를 위해서 변경 집합을 이용한 버전 저장 방법들 제안한다. 제안하는 방법들 사이에 성능을 비교하고 평가한다.

Climate Change Scenario Generation and Uncertainty Assessment: Multiple variables and potential hydrological impacts

  • 권현한;박래건;최병규;박세훈
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2010년도 학술발표회
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    • pp.268-272
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    • 2010
  • The research presented here represents a collaborative effort with the SFWMD on developing scenarios for future climate for the SFWMD area. The project focuses on developing methodology for simulating precipitation representing both natural quasi-oscillatory modes of variability in these climate variables and also the secular trends projected by the IPCC scenarios that are publicly available. This study specifically provides the results for precipitation modeling. The starting point for the modeling was the work of Tebaldi et al that is considered one of the benchmarks for bias correction and model combination in this context. This model was extended in the framework of a Hierarchical Bayesian Model (HBM) to formally and simultaneously consider biases between the models and observations over the historical period and trends in the observations and models out to the end of the 21st century in line with the different ensemble model simulations from the IPCC scenarios. The low frequency variability is modeled using the previously developed Wavelet Autoregressive Model (WARM), with a correction to preserve the variance associated with the full series from the HBM projections. The assumption here is that there is no useful information in the IPCC models as to the change in the low frequency variability of the regional, seasonal precipitation. This assumption is based on a preliminary analysis of these models historical and future output. Thus, preserving the low frequency structure from the historical series into the future emerges as a pragmatic goal. We find that there are significant biases between the observations and the base case scenarios for precipitation. The biases vary across models, and are shrunk using posterior maximum likelihood to allow some models to depart from the central tendency while allowing others to cluster and reduce biases by averaging. The projected changes in the future precipitation are small compared to the bias between model base run and observations and also relative to the inter-annual and decadal variability in the precipitation.

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GCM 공간상세화 방법별 기후변화에 따른 수문영향 평가 - 만경강 유역을 중심으로 - (Assessing Hydrologic Impacts of Climate Change in the Mankyung Watershed with Different GCM Spatial Downscaling Methods)

  • 김동현;장태일;황세운;조재필
    • 한국농공학회논문집
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    • 제61권6호
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    • pp.81-92
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    • 2019
  • The objective of this study is to evaluate hydrologic impacts of climate change according to downscaling methods using the Soil and Water Assessment Tool (SWAT) model at watershed scale. We used the APCC Integrated Modeling Solution (AIMS) for assessing various General Circulation Models (GCMs) and downscaling methods. AIMS provides three downscaling methods: 1) BCSA (Bias-Correction & Stochastic Analogue), 2) Simple Quantile Mapping (SQM), 3) SDQDM (Spatial Disaggregation and Quantile Delta Mapping). To assess future hydrologic responses of climate change, we adopted three GCMs: CESM1-BGC for flood, MIROC-ESM for drought, and HadGEM2-AO for Korea Meteorological Administration (KMA) national standard scenario. Combined nine climate change scenarios were assessed by Expert Team on Climate Change Detection and Indices (ETCCDI). SWAT model was established at the Mankyung watershed and the applicability assessment was completed by performing calibration and validation from 2008 to 2017. Historical reproducibility results from BCSA, SQM, SDQDM of three GCMs show different patterns on annual precipitation, maximum temperature, and four selected ETCCDI. BCSA and SQM showed high historical reproducibility compared with the observed data, however SDQDM was underestimated, possibly due to the uncertainty of future climate data. Future hydrologic responses presented greater variability in SQM and relatively less variability in BCSA and SDQDM. This study implies that reasonable selection of GCMs and downscaling methods considering research objective is important and necessary to minimize uncertainty of climate change scenarios.

From Opposition to Cooperation: Semantic Change of with

  • Rhee, Seongha
    • 한국영어학회지:영어학
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    • 제4권2호
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    • pp.151-174
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    • 2004
  • A historical investigation reveals that English preposition with underwent a change from OPPOSITION to ASSOCIATION and further to ACCOMPANIMENT, where the first stage shows peculiarity in that the two concepts involved comprise an unusual set to form an extensional chain. Intrigued by this oddity, this paper aims to investigate the semantic structure of English preposition with from a grammaticalization perspective. We review mechanisms and models of semantic change and evaluate their adequacy with the semantic structure and change shown by with. Drawing upon the observed fact that with underwent the apparent antonymic semantic change, it is argued that such semantic change mechanisms as metaphor, metonymy, subjectification, and generalization have difficulties explaining the change, and that only the Frame-of-Focus Variation can effectively account for this peculiar change type. In terms of semantic change models, we argue that the Bleaching Model cannot effectively provide an explanation; that the Loss and Gain Model has problems in explaining the motivation of change directions; that the Metonymic-Metaphoric Model cannot be assessed at the current level of investigation; and that the Overlap Model and the Prototype Extension Model excellently account for the macro-level changes.

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기호론적 관점에 기초한 홀로코스트 건축의 상징성 분석 - 다니엘 리베스킨드의 유대인 박물관을 중심으로 - (The symbolism analysis of Holocaust architecture on the basis of semiotics point of view - Focus on Daniel Libeskind's Jewish Museum Berlin -)

  • 이승연;이성훈
    • 한국실내디자인학회:학술대회논문집
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    • 한국실내디자인학회 2007년도 춘계학술대회 논문집
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    • pp.270-274
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    • 2007
  • Clearing trace of symbol which was gone with a series of pre-modern architecture history since the modern architecture (pursuing true nature from tradition which is repeated and imitated unconsciously). That is, What is the course of deconstruction? In the early part of the 20th century, We still accept the necessity of decoration in spite of its existence at one time being threaten. This means, even though symbolism in architecture has relative importance by situation of Times, it plays an important role to add the past to current style through 'Symbol'. The history of Times, a carrier which reflects Present on New Futures, makes memory by gathering data but we can not amplify our historical imagination with only data. Data is a past memory and evidence but we can not substitute that for historical experience. And it is difficult for future generations who don't live through that history to change their historical recognition with recollecting memories. They have to draw history with data but it is very limited in itself. However, They can collect historical memory through symbol in architecture. In this study, We pay attention to the symbolism of a memorial hall architecture. So We'll analyze dichotomy concept of Barthes's signifiant and signifie, visual sign and course of symbolic meaning on basis of Daniel Libeskind's Jewish Museum.

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한국(韓國) 건축역사(建築歷史) 연구의 비판(批判)과 방향모색(方向摸索) - 실천이론(實踐理論)으로서의 건축역사방법(建築歷史方法)- (The Critique and Search for a Way of Historical Study of Korean Architecture - Method as a Theory of Practice -)

  • 이희봉
    • 건축역사연구
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    • 제1권1호
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    • pp.240-254
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    • 1992
  • The purpose of this paper is to suggest new direction to the historical research society of Korean architecture by epistemological discussion. Korean architectural history at present, without question of history for what, for whom, and how, is regarded as 'history for the past' only 'to describe past' or 'to collect correct data' However, history is beyond that; history ought to suggest a direction of present and near future. Moreover, architecture is not pure but applied knowledge, that is, focused to 'how to build'. Therefore, past historical knowledge by research should influence to present design. In order to do that, history of mere data collection should change direction to the history of meaning by interpretation, and then, of finding design principle. The principle used in architectural community becomes theory in scientific research community, and finally is unified to 'theory of practice'. Creative history should be substituted for retrospective history reusing historical reservoir, at the specific situation of Korea; tradition has been discontinued drastically and Western method imported to the point of being culturally-colonized. Some expmples of altanative history are suggested at the end of this paper as conclusion.

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한어방언(漢語方言) 어음 연구의 이론적 배경

  • 모정열
    • 중국학논총
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    • 제64호
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    • pp.23-51
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    • 2019
  • All research methodologies have a certain research purpose and application range. Therefore, it cannot be conclusively said that some methodologies are superior. Each research methodology has only different research purposes and application ranges. The various theories and methodologies related to the study of Chinese dialect sounds have not been in a confrontational relationship with each other. But the need for analysis of new phenomena has led to the emergence of new methodologies and it has been deepening the depth of the study together, supplementing the theories of the past. The emergence of new theories and methodologies has not only always provided another means for dialect analysis methods, but has also deepened awareness of the changing rules of dialects, the interrelationships between rules and the causes of change. The Chinese dialect is richly embedded in various phenomena that can be seen in human languages. In analyzing the phenomenon of the Chinese dialect, we should first closely observe and judge whether it is the result of internal historical changes in the dialect itself or changes formed by contact or influence with the external dialect, and apply the analytical method accordingly. Sometimes there is a phenomenon formed by a number of complex factors, not one, that requires a comprehensive analysis that combines a variety of theories and methodologies.

미적분의 역사와 변증법적 유물론 (A History of Calculus and the Dialectical Materialism)

  • 조윤동
    • 대한수학교육학회지:학교수학
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    • 제5권4호
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    • pp.521-540
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    • 2003
  • 수학이 발달해 온 과정과 그 결과물은 언제나 역사적 한계 속에서 역사적 필연성에 의해 그 한계를 돌파해 온 과정이자 결과물이었다. 이러한 모습을 미적분학의 역사를 통해서 보여주려 한 것이 이 글이다 이 글을 전개하는데 밑바탕에 전제로 두고 있는 것은 변증법적 유물론이다. 이것은 변화와 발전을 개인의 주관적인 판단이 아니라 사회-역사적인 물적 조건을 일차적인 것으로 하여 일어나는 것으로 본다. 유물변증법은 기원전 4세기 무렵의 아르키메데스 시대 이후 한동안의 공백기를 지나 17세기에 본격적으로 다루어지게 된 미적분을 설명하는데 적격이다. 또한 그것은 미적분의 발달 과정에서 보이는 여러 번의 동시 발견과 같은 것들을 설명하는데도 적격이다 필자는 이 글을 통해서 수학이 단순히 기호의 형식논리학적 전개나 주관에 의한 발명이 아니라 사회-역사적 산물임을 보이려 한다 이를 통해서 수학 교수-학습을 현실 세계로부터 출발해야 한다는 논의에 철학적 바탕을 제공하고자 한다.

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불확실성을 고려한 논벼 증발산량 기후변화 영향 평가 (Assessing the Climate Change Impacts on Paddy Rice Evapotranspiration Considering Uncertainty)

  • 최순군;정재학;조재필;허승오;최동호;김민경
    • 한국기후변화학회지
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    • 제9권2호
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    • pp.143-156
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    • 2018
  • Evapotranspiration is a key element in designing and operating agricultural hydraulic structures. The profound effect of climate change to local agro-hydrological systems makes it inevitable to study the potential variability in evapotranspiration rate in order to develop policies on future agricultural water management as well as to evaluate changes in agricultural environment. The APEX-Paddy model was used to simulate local evapotranspiration responses to climate change scenarios. Nine Global Climate Models(GCMs) downscaled using a non-parametric quantile mapping method and a Multi?Model Ensemble method(MME) were used for an uncertainty analysis in the climate scenarios. Results indicate that APEX-Paddy and the downscaled 9 GCMs reproduce evapotranspiration accurately for historical period(1976~2005). For future periods, simulated evapotranspiration rate under the RCP 4.5 scenario showed increasing trends by -1.31%, 2.21% and 4.32% for 2025s(2011~2040), 2055s(2041~2070) and 2085s(2071~2100), respectively, compared with historical(441.6 mm). Similar trends were found under the RCP 8.5 scenario with the rates of increase by 0.00%, 4.67%, and 7.41% for the near?term, mid?term, and long?term periods. Monthly evapotranspiration was predicted to be the highest in August, July was the month having a strong upward trend while. September and October were the months showing downward trends in evapotranspiration are mainly resulted from the shortening of the growth period of paddy rice due to temperature increase and stomatal closer as ambient $CO_2$ concentration increases in the future.