• Title/Summary/Keyword: ESP

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Improvement of streamflow forecast using a Bayesian inference approach (베이지안 기법을 통한 유량예측 정확도 개선)

  • Seo, Seung Beom;Kim, Young-Oh;Kang, Shin-Uk
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.303-303
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    • 2018
  • 안정적인 수자원 운용을 위해서는 정확한 유량예측 기술이 필요하다. 본 연구에서는 유량예측 정확도의 개선을 위해 베이지안 추론(Bayesian inference) 기법과 앙상블 유량 예측(Ensemble Streamflow Prediction, ESP) 기법의 결합을 통한 새로운 유량예측 기법(Bayesian ESP)을 제안하였다. ESP를 통한 유량 예보 앙상블은 베이지안 추론의 사전정보로 활용되며, 관측 유량과 ESP 전망 결과의 선형관계를 통해 우도함수가 추정된다. 우도함수는 관측 유량이 존재하는 과거 기간에 대한 ESP를 수행한 후 예보 시점의 관측 유량(concurrent observed flow)과 선행 관측 유량(lagged observed flow)과의 다중선형회귀 모형을 통해 추정된다. 사전정보와 우도함수는 정규분포로 가정되며, 따라서 최종 유량예측인 사후정보 역시 정규분포함수로 산정되게 된다. Bayesian ESP은 ESP에서 발생하는 강우-유출모형 오차의 개선을 통해 수문예측의 정확도를 개선하게 되며 정규분포함수로 최종 결과가 산정되므로 확률예보 형태의 수문 전망도 가능하다. 본 기법을 전국 35개 댐 유역에 시범적용을 한 결과, 모든 유역에서 기존 ESP 기법 대비 수문예측 정확도의 개선을 가져왔으며, 우도함수 추정에 있어 선행 유량의 포함 여부가 수문 예측 정확도의 추가적인 개선을 가져왔다. 본 기법은 주간 예보부터 계절 예보까지 탄력적으로 구축이 가능하며 적용 결과 리드 타임이 길어질수록 예측 능력이 감소되었지만 전체 구간에 있어서 Bayesian ESP 기법이 가장 우수한 예측 정확도를 보여주었다.

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Uncertainty assessment of ensemble streamflow prediction method (앙상블 유량예측기법의 불확실성 평가)

  • Kim, Seon-Ho;Kang, Shin-Uk;Bae, Deg-Hyo
    • Journal of Korea Water Resources Association
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    • v.51 no.6
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    • pp.523-533
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    • 2018
  • The objective of this study is to analyze uncertainties of ensemble-based streamflow prediction method for model parameters and input data. ESP (Ensemble Streamflow Prediction) and BAYES-ESP (Bayesian-ESP) based on ABCD rainfall-runoff model were selected as streamflow prediction method. GLUE (Generalized Likelihood Uncertainty Estimation) was applied for the analysis of parameter uncertainty. The analysis of input uncertainty was performed according to the duration of meteorological scenarios for ESP. The result showed that parameter uncertainty was much more significant than input uncertainty for the ensemble-based streamflow prediction. It also indicated that the duration of observed meteorological data was appropriate to using more than 20 years. And the BAYES-ESP was effective to reduce uncertainty of ESP method. It is concluded that this analysis is meaningful for elaborating characteristics of ESP method and error factors of ensemble-based streamflow prediction method.

Estimation of ESP Probability considering Weather Outlook (기상예보를 고려한 ESP 유출 확률 산정)

  • Ahn, Jung Min;Lee, Sang Jin;Kim, Jeong Kon;Kim, Joo Cheol;Maeng, Seung Jin;Woo, Dong Hyeon
    • Journal of Korean Society on Water Environment
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    • v.27 no.3
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    • pp.264-272
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    • 2011
  • The objective of this study was to develop a model for predicting long-term runoff in a basin using the ensemble streamflow prediction (ESP) technique and review its reliability. To achieve the objective, this study improved not only the ESP technique based on the ensemble scenario analysis of historical rainfall data but also conventional ESP techniques used in conjunction with qualitative climate forecasting information, and analyzed and assessed their improvement effects. The model was applied to the Geum River basin. To undertake runoff forecasting, this study tried three cases (case 1: Climate Outlook + ESP, case 2: ESP probability through monthly measured discharge, case 3: Season ESP probability of case 2) according to techniques used to calculate ESP probabilities. As a result, the mean absolute error of runoff forecasts for case 1 proposed by this study was calculated as 295.8 MCM. This suggests that case 1 showed higher reliability in runoff forecasting than case 2 (324 MCM) and case 3 (473.1 MCM). In a discrepancy-ratio accuracy analysis, the Climate Outlook + ESP technique displayed 50.0%. This suggests that runoff forecasting using the Climate Outlook +ESP technique with the lowest absolute error was more reliable than other two cases.

Long-term Streamflow Prediction Using ESP and RDAPS Model (ESP와 RDAPS 수치예보를 이용한 장기유량예측)

  • Lee, Sang-Jin;Jeong, Chang-Sam;Kim, Joo-Cheol;Hwang, Man-Ha
    • Journal of Korea Water Resources Association
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    • v.44 no.12
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    • pp.967-974
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    • 2011
  • Based on daily time series from RDAPS numerical weather forecast, Streamflow prediction was simulated and the result of ESP analysis was implemented considering quantitative mid- and long-term forecast to compare the results and review applicability. The result of ESP, ESP considering quantitative weather forecast, and flow forecast from RDAPS numerical weather forecast were compared and analyzed with average observed streamflow in Guem River Basin. Through this process, the improvement effect per method was estimated. The result of ESP considering weather information was satisfactory relatively based on long-term flow forecast simulation result. Discrepancy ratio analysis for estimating accuracy of probability forecast had similar result. It is expected to simulate more accurate flow forecast for RDAPS numerical weather forecast with improved daily scenario including time resolution, which is able to accumulate 3 hours rainfall or continuous simulation estimation.

ESP : A DVR File Format for Enhanced Recording and Searching (ESP : 녹화 및 검색 기능 향상을 위한 DVR전용 파일 포맷)

  • Park, Jae-Kyung;Yang, Seung-Min
    • The KIPS Transactions:PartB
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    • v.16B no.1
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    • pp.25-34
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    • 2009
  • DVR(Digital Video Recorder) system stores video inputs in compressed digital formats and retrieve them. DVR system has several advantages over traditional analog tape recorder system which are (1) improved real-time monitoring, recording and searching capability, and (2) other capabilities such as watermarking and remote monitoring through network. AVI format is the most popular format used for DVR systems. However, AVI format has drawbacks in recording and searching due to structural problem. Some vendors develop and use their own format, do not open the format to the public. In this paper, ESP format is proposed. ESP format solves the drawbacks of AVI format, and the advantages of AVI format apply to ESP format. Moreover, ESP format provides multistream recording/replay and event-recording. In result, ESP format enchances functionality of recording and searching in DVR system.

A Mechanism for the Secure IV Transmission in IPSec (IPSec에서 안전한 IV 전송을 위한 메커니즘)

  • Lee, Young-Ji;Park, Nam-Sup;Kim, Tai-Yun
    • Journal of KIISE:Information Networking
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    • v.29 no.2
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    • pp.156-164
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    • 2002
  • IPSec is a protocol which provides data encryption, message authentication and data integrity on public and open network transmission. In IPSec, ESP protocol is used when it needs to provide data encryption, authentication and Integrity In real transmission packets. ESP protocol uses DES-CBC encryption mode when sender encrypts packets and receiver decrypts data through this mode IV is used at that time. This value has many tasks of attack during transmission by attacker because it is transferred clean and opened. If IV value is modified, then decryption of ESP data is impossible and higher level information is changed. In this paper we propose a new algorithm that it encrypts IV values using DES-ECB mode for preventing IV attack and checks integrity of whole ESP data using message authentication function. Therefore, we will protect attacks of IV and data, and guarantee core safe transmission on the public network.

Implementation of Wifi Robot Car using NodeMCU ESP-12 Board (NodeMCU ESP-12E 보드를 이용한 Wifi 로봇자동차 구현)

  • Son, Byung-jin;Lee, Dong-woo;Seo, Dong-hyeon;Kim, Mi-seong;Jo, Jae-ik;Choi, Byeong-yoon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2017.05a
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    • pp.475-477
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    • 2017
  • In this paper Wifi robot car working as web sever on wifi network was implemented using NodeMCU ESP-12E board and its operation was verified using web browser of smart phone and PC. Current research result can be applicable to Wifi home automation applications with ESP-12E board.

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Effects of egg shell calcium treatments on the short-term storage of cut Kimchi cabbage (난각 칼슘 소재 처리에 의한 절단배추 단기 저장 효과)

  • Seong, Gi-Un;Chung, Hun-Sik;Chung, Shin-Kyo
    • Food Science and Preservation
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    • v.24 no.1
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    • pp.1-7
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    • 2017
  • This study was conducted to investigate the effects of egg shell calcium treatments on short-term storage of cut Kimchi cabbage. Egg shell ash powder (ESP-2) had the greatest calcium contents. Calcium solubility was greater in citric acid than acetic acid and ascorbic acid. Cut Kimchi cabbages ($3{\times}3cm$) were treated with 0.5%, 1.0%, and 2.0% egg shell powder (ESP-1), and egg shell ash powder (ESP-2), and 0.5% citric acid, put inside polyethylene (PE) bags, and stored at $5^{\circ}C$ for 6 weeks. Weight loss was about 99.85-99.90%, and the ratio was the lowest upon 0.5% ESP-2 treatment (p<0.05). The reduction ratios of soluble solids were 21.3-43.4%, and decreased in the order of 1.0% ESP-2 treatment and 0.5% ESP-1. The $L^*$ values decreased, whereas $a^*$ and $b^*$ values of Hunter colorimetry increased in all treatments. ${\Delta}E$ values were lowest upon 0.5% ESP-2 treatment. 0.5% ESP-2 treatment showed better quality characteristics than other treatments. Thus, egg shell calcium treatments could effectively enhance the shelf-life of cut Kimchi cabbage.

Excretory-secretory product of newly excysted metacercariae of Paragonimus westermani directly induces eosinophil apoptosis

  • Shin, Myeong-Heon
    • Parasites, Hosts and Diseases
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    • v.38 no.1
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    • pp.17-23
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    • 2000
  • Eosinophils are important effector cells in host defense against parasites. Excretory-secretory product (ESP) produced by helminthic worms plays important roles in the uptake of nutrients, migration in the host tissue, and in immune modulation. However little is known about the ability of the ESP to directly trigger eosinophil apoptosis. This study investigated whether the ESP of newly excysted metacercariae of Paragonimus westermani could induce apoptosis in human eosinophils. Apoptosis was assayed by staining the cells with FITC-annexin V, and the cells were analyzed by flow cytometry. It was found that the ESP of newly excysted metacercariae of P. westemani induced a direct time- and concentration-dependent increase in the rate of constitutive apoptosis in mature human eosinophils. Eosinophil apoptosis was first apparent 3 hr after treatment with the ESP and continued to increase after 6 hr of incubation with respect to the cells cultured in the absence of the ESP. While only 2.8% of the eosinophils incubated in the medium for 3 hr were apoptotic, 7.6%, 10.9% and 22.6% of the eosinophils treated with 10. 30 and $100{\;}\mu\textrm{g}/ml$ ESP were apoptotic, respectively. This result suggests that the ESP of newly excysted metacercariae of P. westermani directly induce eosinophil apoptosis, which may be important for the survival of the parasites and the reduction of eosinophilic inflammation in vivo.

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Designing ESP Curriculum for EFL Learners at College of Navigation

  • Choi, Seung-Hee
    • Journal of Navigation and Port Research
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    • v.38 no.2
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    • pp.127-134
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    • 2014
  • This paper aims to identify what is needed to improve the English for Specific Purposes(ESP) curriculum for English as a Foreign Language(EFL) college learners at navigation school. Different needs from learners and experienced professionals are identified through diversified methods, and the findings from these are analysed and consolidated from a balanced point of view. For this purpose, putting learners at the centre of analysis, identifying their subjective and objective needs serves as a point of departure in formulating the curriculum. Then, the target situation is analysed according to the short-term aim of getting a job, followed by long-term needs for successfully fulfilling future duties as a pilot. Based on findings, it is suggested that ESP curriculum for learners in navigation studies should be focused on the successful language performance of their actual duties and tasks to be given in the future working situations, rather than on immediate needs for getting a job. In particular, special attention needs to be paid to enhancing learners' productive language competences through a series of hands-on trainings and a wide range of extra-curricular activities, specifically for a higher command of oral communication. For this, not only ESP, curriculum for EGP(English for General Purposes) should be systematically structured as ESP-oriented EGP, and naturally move onto areas of ESP in a coherent manner.