• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.149-149
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• 2022

Accurate quantitative evaluation of baseflow contribution to streamflow is imperative to address seasonal drought vulnerability, flood occurrence and groundwater management concerns for efficient and sustainable water resources management in watersheds. Several baseflow separation algorithms using recursive filters, graphical method and tracer or chemical balance have been developed but resulting baseflow outputs always show wide variations, thereby making it hard to determine best separation technique. Therefore, the current global shift towards implementation of artificial intelligence (AI) in water resources is employed to compare the performance of deep learning models with conventional hydrograph separation techniques to quantify baseflow contribution to streamflow of Piney River watershed, Tennessee from 2001-2021. Streamflow values are obtained from the USGS station 03602500 and modeled to generate values of Baseflow Index (BI) using Web-based Hydrograph Analysis (WHAT) model. Annual and seasonal baseflow outputs from the traditional separation techniques are compared with results of Long Short Term Memory (LSTM) and simple Gated Recurrent Unit (GRU) models. The GRU model gave optimal BFI values during the four seasons with average NSE = 0.98, KGE = 0.97, r = 0.89 and future baseflow volumes are predicted. AI offers easier and more accurate approach to groundwater management and surface runoff modeling to create effective water policy frameworks for disaster management.

• 대한지리학회지
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• 제42권4호
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• pp.616-631
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• 2007

거주지 분화 현상은 도시적 삶의 공간성을 파악하는데 본질적인 요소이기 때문에 도시학 연구에서 오랫동안 주목을 받아왔다. 거주지 분화 현상에 대한 연구 과제 중의 하나가 상이한 두 집단이 얼마나 공간적으로 분리되어 있는지를 측정하는 문제이다. 이러한 측면에서 가장 널리 사용되어온 것이 상이지수(index of dissimilarity)인데, 이 지수는 거주지 분리의 '불균등성(unevenness)'은 측정할 수 있지만, 공간적 '집중도(clustering)'는 측정하지 못하는 단점을 갖고 있다. 이러한 단점을 극복하기 위해 제안되어 온 '공간적 격리 지수(spatial indices of segregation)' 역시 가설검정 절차를 제시하지 못하고 최근의 공간통계학 연구 성과를 수용하지 못하는 등의 단점을 가지고 있다. 이러한 의미에서 본 논문의 주된 연구 목적은 새로운 '공간 분리성 측도(spatial separation measure)'를 개발하는 것이다. 이 공간 분리성 측도는 상이한 인구 집단이 거주 공간에 얼마나 불균등하게 분포하고 있는지에 대한 것뿐만 아니라 그러한 불균등 분포가 보여주는 공간적 의존성의 정도까지도 측정하는 새로운 통계량이다. 주요 연구 결과는 다음과 같다. 첫째, 기존의 '공간 연관성 측도(spatial association measures)'와 '공간적 카이-스퀘어 통계량(spatial chi-square statistics)'을 통합하여 새로운 측도를 개발했으며, 일반화된 랜덤화 검정법을 적용해 측도에 대한 유의성 검정법을 제시하였다. 둘째, 개발된 측도와 유의성 검정법을 우리나라 7대 도시의 학력 집단 간 거주지 분리 현상에 적용함으로써, 연구방법론으로서의 유용성을 확인하였다.

• 한국농공학회논문집
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• 제59권2호
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• pp.1-11
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• 2017

The analysis of baseflow contribution is very significant in Korea because most rivers have high variability of streamflow due to the monsoon climate. Recently, the importance of such analysis is being more evident especially in terms of river management because of the changing pattern of rainfall and runoff resulted from climate change. Various baseflow separation methods have been developed to separate baseflow from streamflow. However, it is very difficult to identify which method is the most accurate way due to the lack of measured baseflow data. Moreover, it is inappropriate to analyze the annual baseflow contribution for Korean rivers because rainfall patterns varies significantly with the seasons. Thus, this study compared the baseflow contributions at various time-scales (annual, seasonal and monthly) for the 4 major river basins through BFI (baseflow index) and suggested baseflow contribution of each basin by the BFI ranges searched from different baseflow separation methods (e.g., BFLOW, HYSEP, PART, WHAT). Based on the comparison of baseflow contributions at the three time scales, this study showed that the baseflow contributions from the monthly and seasonal analysis are more reasonable than that from the annual analysis. Furthermore, this study proposes that defining BFI with its range is more proper than a specific value for a watershed, considering the difference of BFIs between various baseflow separation methods.

• 대한전자공학회논문지
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• 제18권3호
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• pp.1-8
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• 1981

In this paper, the recognition method of Hangout patterns with the partial separation for the subpatterns is proposed. First, Hangout patterns are formalized into six formal patterns and their surface structures are discriminated. Second, two to four subpatterns from one form pattern are separated by the new algorithm combined with Index mark and Window. Hangout patterns are recognized with only frontiers of the tree by defining the regular U-tree grammar for the separated subpatterns. Compared with the previous tree grammar , this grammar reduces the production rules to 1/3 and simplifies automaton processing and has more flexiblity. By the simulation result for 1,600 characters of Hangeul patterns, separation rate of subpatterns (24 or 44) is obtained 99.1% and recognition rate is obtained 100 %.

• Journal of Information Processing Systems
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• 제19권6호
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• pp.858-869
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• 2023

As one of the pivotal techniques of image restoration, single-channel blind source separation (SCBSS) is capable of converting a visual-only image into multi-source images. However, image degradation often results from multiple mixing methods. Therefore, this paper introduces an innovative SCBSS algorithm to effectively separate source images from a composite image in various mixed modes. The cornerstone of this approach is a novel triple generative adversarial network (TriGAN), designed based on dual learning principles. The TriGAN redefines the discriminator's function to optimize the separation process. Extensive experiments have demonstrated the algorithm's capability to distinctly separate source images from a composite image in diverse mixed modes and to facilitate effective image restoration. The effectiveness of the proposed method is quantitatively supported by achieving an average peak signal-to-noise ratio exceeding 30 dB, and the average structural similarity index surpassing 0.95 across multiple datasets.

• 대한지하수환경학회지
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• 제7권1호
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• pp.15-19
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• 2000

본 연구는 하천유량 수문곡선의 분리를 통한 기저유량 산정에 관한 것이다. 수문곡선을 분리하기 위하여 Institute of Hydrology(1980)에서 제안한 표준방법(Standard Method)을 이용하였다. 이를 위하여 대상유역의 유역특성치와 기저유출관계를 이용하여 모형의 매개변수를 산정하였으며, 그 결과를 토대로 수문곡선을 분리하여 기저유량을 산정 하였다. 기저유량 산정결과 기저 유출율은 20.0%∼39.4%로 나타났으며, 유역면적이 비교적 큰 유역에서는 기저 유출율이 다소 높게 나타났고, 상대적으로 유역면적이 적은 지역에서는 기저 유출율이 적게 나타났다. 그리고 연 강우량과 기저 유출율의 관계를 분석한 결과 연강우량과 기저 유출율의 상관성은 거의 나타나지 않았다.

• 한국가축번식학회지
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• 제12권3호
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• pp.141-147
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• 1988

These experiments were carried out to develop new techniques for in vitro separation of x-and Y-bearing spermatozoa. The results obtained in these experiments were summarized as follows: 1. Following centrifugation of discontinuous percoll density gradient, populatin of spermatozoa increased progressively from low to high density. The highest concentration of spermatozoa was observed at the 4th fraction which included 36.6% of spermatozoa. 2. As increasing percoll concentration, the higher motility index was obtained and the highest motility index(74.2) was obtained at the 5th fraction. 3. The percentage of B-body bearing spermatozoa following percoll density gradient centrifugation was decreased from 39.7% to 25.6%. 4. The sperm population following chromatography by sephadex gel and percoll density gradient centrifugation was decreased in 1st, 5th and 6th fractions but the reverse was turn for 2nd, 3rd and 7th fractions, and the highest sperm concentration was observed at the 7th fraction which included 37.4% of spermatozoa. 5. Motility index of spermatozoa was increased from 77.6 to 79.4 after the sephadex gel filtration, however it was decreased at all fractions after percoll density gradient centrifugation. The lowest motility index(33.2) was obtained from the 7th fraction. 6. The rate of B-body bearing spermatozoa was shown the trend to decrease by the sephadex gel filtration and the trend was accelerated by the percoll density gradient centrifugation. The lowest percentage of B-body bearing spermatozoa, 12.0% was obtained from the 5th fraction.

• The Journal of Korean Physical Therapy
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• 제21권3호
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• pp.1-8
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• 2009

Purpose: The purpose of this study was to examine the functional category, the item structure and the model-data fit of the neck disability index (NDI) of neck pain subjects by performing a Rasch rating scale analysis. Methods: The data was obtained from the assessments of 71 college students (males: 27, females: 44) with neck pain. The data of the NDI was applied to the Rasch's rating scale model to estimate the difficulty of items, the goodness-of-fit of each item, the separation reliability and index, and the rating scale. Results: The 'sleep' item showed misfit and nine items were founds to be fits for self-reporting of disability due to neck pain. The most difficult item of the remaining 9 items was 'work' and the easiest item was 'headache'. The transformation formula score=(logit score+7.10)/(7.10+0.11)$\times$100. The 6 response levels of the NDI were validated according to the structure of the rating scale. The item and subject reliability of the separation reliability was 0.97 and 0.85, respectively. Conclusion: We proved that the NDI for self-reporting of disability of daily activities due to mild neck pain was valid and reliable. This study suggests that individuals with mild neck pain may be assessed by using the modified NDI that does not include the 'sleep' item in the 10 items of NDI.

• Journal of the Optical Society of Korea
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• 제13권4호
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• pp.468-471
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• 2009

We propose a simple nondestructive method to obtain refractive-index profiles of a graded-index (GRIN) light-focusing rod by means of a diffraction grating. In our proposed method, a laser beam is illuminated through a diffraction grating perpendicular to the axis of the GRIN lens and the separation between the zeroth and first-order diffraction peaks is measured and analyzed. The results demonstrate that the refractive-index profiles of commercially available GRIN lenses can be successfully reconstructed.

• 한국광학회:학술대회논문집
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• 한국광학회 2009년도 동계학술발표회 논문집
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• pp.127-128
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• 2009