• Title/Summary/Keyword: Discharge Control

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Evaluation of hydropower dam water supply capacity (III): development and application of drought operation rule for hydropower dams in Han river (발전용댐 이수능력 평가 연구 (III): 한강수계 발전용댐 가뭄단계별 운영기준 개발 및 효과 분석)

  • Jeong, Gimoon;Kang, Doosun;Kim, Taesoon
    • Journal of Korea Water Resources Association
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    • v.55 no.7
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    • pp.531-543
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    • 2022
  • Integrated water resources management (IWRM) has focused on efficient response to various water related disasters by climate change. In particular, more flexible usage of conventional water resources infrastructures is expected to provide an eco-friendly water management. Multi-purpose dams and water supply dams are well known as water management facilities for securing and supplying water in drought season. Recently, based on the report '2021 multi-purpose use of hydropower dams in Han river', contribution of hydropower dams on water resources management is becoming more significant beyond the traditional role of hydropower generation. In drought conditions, the dams control water supply depending on the pre-defined drought stages. In the case of multi-purpose dams, an operation standard during drought has been already prepared and applied; however, for the hydropower dams, specific standards are not fully prepared yet in South Korea. In this study, a method for calculation of standard water storage and discharge reduction of hydropower dams according to drought stage is newly proposed reflecting the characteristics of hydropower dams. The proposed method was applied to the hydropower dams in Han river, where six hydropower dams are located. A case study of the historical droughts occurred in 2014-2017 demonstrated that the proposed hydropower dam operation rule could improve the water supply stability under severe drought conditions compared to the conventional operations. In the future, the role of hydropower dams for water resources management is expected to become more important, and this study can be widely used for water supply planning such as drought response using hydropower dams.

Effect on Nitrous Oxide Emission in Applying Livestock Manure Compost for Strawberry (Fragaria × ananassa Duch.) Cultivation in Plastic Film House (딸기(Fragaria × ananassa Duch.) 시설재배에서 가축분 퇴비 시용이 아산화질소 배출에 미치는 영향)

  • Lee, Chang-Kyu;Moon, Hyung-Cheol;Song, Eun-Ju;Choi, Seon-U;Ko, Do-Young;Chon, Hyong-Gwon;Yun, Seok-In
    • Korean Journal of Organic Agriculture
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    • v.29 no.1
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    • pp.111-123
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    • 2021
  • This study was conducted to investigate the growth characteristics of strawberries and N2O emission by treating the compost for each type of livestock manure, which was an organic farming material, as a basal fertilization in plastic film house. Livestock manure compost, which made from cattle manure, swine manure, and poultry manure as raw materials, were applied to this experiment, treated by mixing or single on the basis of nitrogen content with the standard amount of fertilizer for strawberries. Total emission of N2O were 10.7% higher than those in poultry manure compost treatment compared to the inorganic fertilizer treatment, but 16.5~41.9% lower than those in other livestock manure compost treatment. The period of N2O emission mainly was up to the 17th day after fertilizer application, accounting for 70~87% of the total amount of discharge, and 13~30% of the total amount was emitted for 158 days later. N2O emission was decreased significantly NH4+-N content in the soil, and increased NO3--N. As compared with control, the number of leaves, leaf width and crown diameter of livestock manure compost treatments were not significantly different, leaf length of cattle+poultry, cattle+ swine, swine+poultry treatment higher, and SPAD (soil plant analysis development) values of cattle+poultry treatment highest. There was no significant difference in weight and sugar content of strawberry fruits among treatments.

Effects of an Infection Control Protocol for Coronavirus Disease in Emergency Mechanical Thrombectomy

  • Eun, Jin;Lee, Min-Hyung;Im, Sang-Hyuk;Joo, Won-Il;Ahn, Jae-Geun;Yoo, Do-Sung;Park, Hae-Kwan
    • Journal of Korean Neurosurgical Society
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    • v.65 no.2
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    • pp.224-235
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    • 2022
  • Objective : Since the outbreak of the coronavirus disease 2019 (COVID-19) pandemic, neurointerventionists have been increasingly concerned regarding the prevention of infection and time delay in performing emergency thrombectomy procedures in patients with acute stroke. This study aimed to analyze the effects of changes in mechanical thrombectomy protocol before and after the COVID-19 pandemic on procedure time and patient outcomes and to identify factors that significantly impact procedure time. Methods : The last-normal-to-door, first-abnormal-to-door, door-to-imaging, door-to-puncture, and puncture-to-recanalization times of 88 patients (45 treated with conventional pre-COVID-19 protocol and 43 with COVID-19 protection protocol) were retrospectively analyzed. The recanalization time, success rate of mechanical thrombectomy, and modified Rankin score of patients at discharge were assessed. A multivariate analysis was conducted to identify variables that significantly influenced the time delay in the door-to-puncture time and total procedure time. Results : The door-to-imaging time significantly increased under the COVID-19 protection protocol (p=0.0257) compared to that with the conventional pre-COVID-19 protocol. This increase was even more pronounced in patients who were suspected to be COVID-19-positive than in those who were negative. The door-to-puncture time showed no statistical difference between the conventional and COVID-19 protocol groups (p=0.5042). However, in the multivariate analysis, the last-normal-to-door time and door-to-imaging time were shown to affect the door-to-puncture time (p=0.0068 and 0.0097). The total procedure time was affected by the occlusion site, last-normal-to-door time, door-to-imaging time, and type of anesthesia (p=0.0001, 0.0231, 0.0103, and 0.0207, respectively). Conclusion : The COVID-19 protection protocol significantly impacted the door-to-imaging time. Shortening the door-to-imaging time and performing the procedure under local anesthesia, if possible, may be required to reduce the door-to-puncture and door-to-recanalization times. The effect of various aspects of the protection protocol on emergency thrombectomy should be further studied.

Real-time flood prediction applying random forest regression model in urban areas (랜덤포레스트 회귀모형을 적용한 도시지역에서의 실시간 침수 예측)

  • Kim, Hyun Il;Lee, Yeon Su;Kim, Byunghyun
    • Journal of Korea Water Resources Association
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    • v.54 no.spc1
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    • pp.1119-1130
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    • 2021
  • Urban flooding caused by localized heavy rainfall with unstable climate is constantly occurring, but a system that can predict spatial flood information with weather forecast has not been prepared yet. The worst flood situation in urban area can be occurred with difficulties of structural measures such as river levees, discharge capacity of urban sewage, storage basin of storm water, and pump facilities. However, identifying in advance the spatial flood information can have a decisive effect on minimizing flood damage. Therefore, this study presents a methodology that can predict the urban flood map in real-time by using rainfall data of the Korea Meteorological Administration (KMA), the results of two-dimensional flood analysis and random forest (RF) regression model. The Ujeong district in Ulsan metropolitan city, which the flood is frequently occurred, was selected for the study area. The RF regression model predicted the flood map corresponding to the 50 mm, 80 mm, and 110 mm rainfall events with 6-hours duration. And, the predicted results showed 63%, 80%, and 67% goodness of fit compared to the results of two-dimensional flood analysis model. It is judged that the suggested results of this study can be utilized as basic data for evacuation and response to urban flooding that occurs suddenly.

A Case of Psychogenic Tremor Improved by Complex Korean Medicine Treatment Including Cheongshimondam-tang-gamibang and Acupuncture Treatment - A Case Report (청심온담탕가미방과 침구치료를 포함한 복합한의치료로 호전된 심인성 떨림 환자 1례 - 증례보고)

  • Jihyun Lee;Seokyeong Yoon;Hyoenjun Cheon;Sungjun Joo;Jisu Lee;Jungtae Leem;Yanghee Han
    • The Journal of Internal Korean Medicine
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    • v.43 no.6
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    • pp.1186-1197
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    • 2022
  • Objectives: A case study about the effectiveness of integrative Korean medicine treatment in a psychogenic tremor patient. Case presentation: A 36-year-old male diagnosed with psychogenic tremor with low back pain underwent 29 days of inpatient treatment and 4 weeks of outpatient treatment. His pattern identification was a psychogenic tremor of the weakness of the heart and gall bladder (SimDamHeoGup) type. The treatments were herbal medicine and acupuncture. He took Cheongshimondam-tang for 29 days and Chunwangbosim-dan for 6 weeks when he had symptoms. He also received acupuncture for 20 minutes twice a day at GB20 (Pungji), L14 (Hapgok), HT4 (Yeongdo), PC6 (Naegwan), HT7 (Sinmun), GB34 (Yangleungcheon), ST36 (Joksamni), SP6 (Sameumgyo), and LR3 (Taechung). After 8 weeks of treatment, the Fahn Tolosa Marin rating (FTM) scale of his tremor, at rest, dropped from Grade 4 on both upper extremities, trunk, and both lower extremities at the time of admission to Grade 2 in both upper extremities and trunk, and Grade 0 in both lower extremities at the time of discharge. His Beck Anxiety Inventory (BAI) score decreased from 38 to 7, and his numerical rating scale (NRS) decreased from 8 to 1 for low back pain and from 9 to 2 for tremor. A follow-up visit to the hospital 2 months after the end of treatment confirmed continued symptom improvements and no significant side effects. Conclusions: This study suggests the possibility of treating psychogenic tremor using only Korean medicine treatments. Further studies with control groups and long-term follow-up are needed.

Research on Real-time Flow Rate Measurement and Flood Forecast System Based on Radar Sensors (레이다 센서 기반 실시간 유량 측정 및 홍수 예측 시스템 연구)

  • Lee, Young-Woo;Seok, Hyuk-Jun;Jung, Kee-Heon;Na, Kuk-Jin;Lee, Seung-Kyu
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2022.05a
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    • pp.288-290
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    • 2022
  • As part of the SOC digitization for smart water management and flood prevention, the government reported that automatic and remote control system for drainage facilities (180 billion won) to 57% of national rivers and established a real-time monitoring system (30 billion won). In addition, they were also planning to establish a smart dam safety management system (15 billion won) based on big data at 11 regions. Therefore, research is needed for smart water management and flood prevention system that can accurately calculate the flow rate through real-time flow rate measurement of rivers. In particular, the most important thing to improve the system implementation and accuracy is to ensure the accuracy of real-time flow rate measurements. To this end, radar sensors for measuring the flow rate of electromagnetic waves in the United States and Europe have been introduced and applied to the system in Korea, but demand for improvement of the system continues due to high price range and performance. Consequently, we would like to propose an improved flow rate measurement and flood forecast system by developing a radar sensor for measuring the electromagnetic surface current meter for real-time flow rate measurement.

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Determination of Floodplain Restoration Area Based on Old Maps and Analysis on Flood Storage Effects of Flood Mitigation Sections (고지도를 활용한 홍수터 복원 구역 선정 및 홍수완충공간의 홍수 저류효과 분석)

  • Dong-jin Lee;Un Ji;Sanghyuk Kim;Hong-Kyu Ahn;Eun-kyung Jang
    • Ecology and Resilient Infrastructure
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    • v.10 no.2
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    • pp.40-49
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    • 2023
  • To reduce the damage of extreme flooding caused by climate change and to create flood mitigation sections in a nature-friendly riparian area, it is necessary to restore the floodplain area by referring to the past floodplain section of the current inland waterfront area before the levee was built. This study proposed a method of selecting a location for floodplain restoration using old maps of the Geum River study section and analyzed the effect of flood level reduction through unsteady flow numerical simulations using the floodplain as a flood mitigation space. As a result of analyzing changes in the river areas using old maps, the river section was estimated to gradually reduce by 27.8% (1,059,380 m2) in 2020 compared to 1919, and it was found to have an effective storage capacity of 2,200,868 m3 when restored to offline storage. The flood level and discharge control effects analyzed based on HEC-RAS unsteady flow simulation were 16 cm and 219.01 m3/s, respectively, in the downstream cross-section. In the numerical simulation in this paper, the flood mitigation space was applied as an offline reservoir. The effect of reducing the flood level may differ if levee retreat/relocation is applied.

A Modified grid-based KIneMatic wave STOrm Runoff Model (ModKIMSTORM) (I) - Theory and Model - (격자기반 운동파 강우유출모형 KIMSTORM의 개선(I) - 이론 및 모형 -)

  • Jung, In Kyun;Lee, Mi Seon;Park, Jong Yoon;Kim, Seong Joon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.6B
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    • pp.697-707
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    • 2008
  • The grid-based KIneMatic wave STOrm Runoff Model (KIMSTORM) by Kim (1998) predicts the temporal variation and spatial distribution of overland flow, subsurface flow and stream flow in a watershed. The model programmed with C++ language on Unix operating system adopts single flowpath algorithm for water balance simulation of flow at each grid element. In this study, we attempted to improve the model by converting the code into FORTRAN 90 on MS Windows operating system and named as ModKIMSTORM. The improved functions are the addition of GAML (Green-Ampt & Mein-Larson) infiltration model, control of paddy runoff rate by flow depth and Manning's roughness coefficient, addition of baseflow layer, treatment of both spatial and point rainfall data, development of the pre- and post-processor, and development of automatic model evaluation function using five evaluation criteria (Pearson's coefficient of determination, Nash and Sutcliffe model efficiency, the deviation of runoff volume, relative error of the peak runoff rate, and absolute error of the time to peak runoff). The modified model adopts Shell Sort algorithm to enhance the computational performance. Input data formats are accepted as raster and MS Excel, and model outputs viz. soil moisture, discharge, flow depth and velocity are generated as BSQ, ASCII grid, binary grid and raster formats.

A study on the feasibility analysis of the current flood season: a case study of the Yongdam Dam (현행 법정홍수기 타당성 검토 및 개선에 관한 연구: 용담댐 사례)

  • Lee, Jae Hwang;Kim, Gi Joo;Kim, Young-Oh
    • Journal of Korea Water Resources Association
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    • v.57 no.5
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    • pp.359-369
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    • 2024
  • Korea prepares for potential floods by designating June 21st to September 20th as the flood season. However, many dams in Korea have suffered from extreme floods caused by different climate patterns, as in the case of the longest consecutive rain of 54 days in the 2020's flood season. In this context, various studies have tried to develop novel methodologies to reduce flood damage, but no study has ever dealt with the validity of the current statutory flood season thus far. This study first checked the validity of the current flood season through the observation data in the 21st century and proved that the current flood season does not consider the effects of increasing precipitation trends and the changing regional rainfall characteristics. In order to deal with these limitations, this study suggested seven new alternative flood seasons in the research area. The rigid reservoir operation method (ROM) was used for reservoir simulation, and the long short-term memory (LSTM) model was used to derive predicted inflow. Finally, all alternatives were evaluated based on whether if they exceeded the design discharge of the dam and the design flood of the river. As a result, the floods in the shifted period were reduced by 0.068% and 0.33% in terms of frequency and duration, and the magnitude also decreased by 24.6%, respectively. During this period, the second evaluation method also demonstrated that flood decreased from four to two occurrences. As the result of this study, the authors expect a formal reassessment of the flood season to take place, which will ultimately lead to the preemptive flood response to changing precipitation patterns.

A Case Report of Complex Korean Medicine Treatment Including Modified Gamiguibi-tang in a Paraneoplastic Cerebellar Degeneration Patient with Dysarthria and Weakness of Distal Extremity (구음장애와 사지원위부 무력감을 호소하는 신생물딸림소뇌변성 환자에 대한 가미귀비탕가감방을 포함한 한의복합치료 1례)

  • Ji-hyeon Kang;Seo-hyun Kim;Chae-eun Kim;Hee-ju Won;Kyungmin Baek
    • The Journal of Internal Korean Medicine
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    • v.45 no.3
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    • pp.497-507
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    • 2024
  • Objectives: This study investigated the treatment response to Korean medicine of a paraneoplastic cerebellar degeneration (PCD) patient with dysarthria and weakness of distal extremity. Case presentation: A 53-year-old female diagnosed with PCD complained of dysarthria and weakness of distal extremity. During 32-day hospitalization, she was treated with Korean medicine, namely, herbal medicine (modified Gamiguibi-tang), acupuncture (15 minutes twice a day at CV23, HT7, LI4, LR3, ST36, SP6, GB20, TE17, PC6, GV20, Ex-HN1, GV24 etc.), moxibustion, and cupping, combined with Western medicine (prednisolone, azathioprine) and physical therapy. Post-treatment, the patient global assessment (PGA) score of dysarthria fell from 100 to 60; grasp power rose from 15 kg to 19 kg and 13 kg to 17 kg in the right and left hands, respectively; and the 5-level EQ-5D version (EQ-5D-5L), EQ visual analogue scale (EQ-VAS), and Beck depression inventory (BDI-II) scores changed from 10 to 8, 0 to 80, and 34 to 7 respectively. Follow-up visits continued for about a month after discharge, improvement in symptoms maintained, and there were no significant side effects. Conclusions: Given the lack of standard treatment for PCD, Korean medicine can be tried clinically for the treatment of PCD patients with dysarthria and weakness of distal extremity. However, further studies with control groups are needed.