Restoration Modeling Analysis for Abandoned Channels of the Mangyeong River

( Jae Hoon Kim ),( Pierre Y. Julien ),( Un Ji ),( Joon Gu Kang ) 한국환경과학회 2011 한국환경과학회지 Vol.20 No.5

This study examines the potential restoration of abandoned channels of the Mangyeong River in South Korea. To analyze the morphological changes and equilibrium conditions, a flow duration analysis was performed to obtain the discharge of 255 m3/s with a recurrence interval of 1.5 year. It is a gravel-bed stream with a median bed diameter of 36 mm. The reach-averaged results using HEC-RAS showed that the top width is 244 m, the mean flow depth is 1.11 m, the width/depth ratio is very high at 277, the channel velocity is 1.18 m/s, and the Froude number is also high at 0.42. The hydraulic parameters vary in the vicinity of the three sills which control the bed elevation. The total sediment load is 6,500 tons per day and the equivalent sediment concentration is 240 mg/l. The Engelund-Hansen method was closer to the field measurements than any other method. The bed material coarser than 33 mm will not move. The methods of Julien-Wargadalam and Lacey gave an equilibrium channel width of 83 m and 77 m respectively, which demonstrates that the Mangyeong River is currently very wide and shallow. The planform geometry for the Mangyeong River is definitely straight with a sinuosity as low as 1.03. The thalweg and mean bed elevation profiles were analyzed using field measurements in 1976, 1993 and 2009. The measured profiles indicated that the channel has degraded about 2 m since 1976. The coarse gravel material and large width-depth ratio increase the stability of the bed material in this reach.

Equations of Hydraulic Geometry for Fluvial Channels

Lee, Jong-Seok,Julien, Pierre Y. 한밭대학교 2004 한밭대학교 논문집 Vol.21 No.-

沖積水路에 대한 水理學的 形狀 方程式이 回歸分析法을 適用하여 많은 滿堤流量 자료로부터 誘導되었다. 수리학적 형상을 표현하는 4개의 방정식은 水路幅 W와 平均水深 h 및 平均流速 V, 水路傾斜 S에 관한 非線型 回歸式이다. 이들 방정식은 만제 흐름조건에서의 流量 Q와 平均粒徑 D_(50) 및 Shields 媒介變數 τ_(*)를 獨立變數로 갖는다. 유도된 회귀방정식은 實驗·現場資料와의 檢定 및 檢證에서 아주 잘 一致하는 것으로 나타났으며, 他 模型(Julien and Wargadalam, 1995)과의 比較에서도 좋은 結果를 나타냈다. Equations of hydraulic geometry for the fluvial channels is derived by applying regression analysis to a large database in bankfull discharge. The four equations describing hydraulic geometry are channel width W, averaged flow depth h, mean flow velocity V, and channel slope S. The three independent variables are discharge Q, median bed particle diameter D_(50) and Shields parameter τ_(*) at bankfull conditions. The regression equations are in excellent agreement with the field and laboratory measurements. The exponents of the derived equation are comparable to those of Julien and Wargadalam (1995) but based on R2 values, the derived equations perform better.

평형하상 이론을 이용한 청미천 구하도 복원 대상구간의 안정하도 평가 및 설계

지운(Ji Un),Pierre Y. Julien,강준구(Kang Joon Gu),여홍구(Yeo Hong Koo) 대한토목학회 2010 대한토목학회논문집 B Vol.30 No.3B

하천 복원 설계는 하천 수리 및 유사 수리학적, 하천 지형 및 형태학적, 그리고 생태환경적인 측면까지 모두 고려하여 인위적이지 않고 자연 상태에 가까운 평형하천의 형태를 갖도록 안정성을 최대화하면서 유지 관리 작업은 최소화하는 방향으로 수행해야 한다. 이를 위해서는 우선 평형하상 이론을 고려한 복원 하천 및 하도의 안정성에 대한 평가가 선행되어야 한다. 이러한 평형하상 이론 방법은 일반적으로 크게 해석적 방법 또는 경험적 방법의 형태로 발전되어 왔다. 본 논문에서는 청미천 구하도 복원이 실시되는 구간에 대해서 해석적 방법의 대표적인 Copeland 방법을 기본 모듈로 채택하고 있는 SAM 프로그램을 이용하여 안정하도를 설계하였으며 경험적 방법의 평형공식(하류하천 수리기하 공식)들을 이용하여 현재하도의 안정성을 평가하고 분석하였다. 해석적, 경험적 방법들로 분석된 결과들은 구하도 구간의 하도 형태 설계를 위한 자료로 활용하기 위한 것이다. Copeland 방법을 이용한 분석 결과, 청미천 대상구간의 안정하도는 현재하도보다 폭이 좁고 수심이 큰 그리고 경사가 완만한 하도인 것으로 나타났다. 또한 수리기하공식을 이용하여 복원 하천의 하폭 및 경시를 예측한 결과, 예측된 평형하도의 하폭은 현재 하도의 하폭보다 폭이 좁은 것으로 예측되었으며, 특히 Julien and Wargadalam 방법으로 예측한 결과 현재하도가 평형상태에 도달하기 위해서는 경사가 현재상태보다 더 완만해져야 되는 것으로 나타났다. River restoration or rehabilitation should be conducted in a way to maximize the channel stability with natural river configuration close to the equilibrium condition considering divers aspects of fluvial hydraulics, erosion and sedimentation, fluvial geomorphology, and ecological environment and to minimize the maintenance work. Therefore, the channel stability evaluation for present condition based on the equilibrium channel concept should be preceded for the river restoration project. Methods for equilibrium channel theory have generally been developed following either analytical regime theory or empirical regime theory. The main purpose of this paper is to evaluate the stability of present channel condition for the section of abandoned channel restoration in Cheongmi Stream using the Stable channel Analytical Model (SAM) and equilibrium hydraulic geometry equations. The results of analytical and empirical regime theories should provide fundamental and essential information to design the stable channel geometry. As a calculation result of Copeland's method for the study reach, the equilibrium channel has a narrower channel width, deeper water depth, and more gentle slope than the present channel geometry. As results of equilibrium hydraulic geometry equations, predicted equilibrium widths are less than the channel width in the field. It is represented that the current bed slope must be gentle to reach the equilibrium condition according to the results of Julien and Wargadalam method.

Permissioned Blockchain frameworks in the Industry: A comparison

Julien Polge,Jérémy Robert,Yves Le Traon 한국통신학회 2021 ICT Express Vol.7 No.2

Permissioned and private blockchain platforms are increasingly used in today’s industry. This paper provides a comprehensive and comparative study of the 5 major frameworks (Fabric, Ethereum, Quorum, MultiChain and R3 Corda) with regard to the community activities, performance, scalability, privacy and adoption criteria. Based on a literature review, this study shows that even if Fabric is promising, the final selection of a framework for a specific case-study is always a trade-off. Finally, lessons learnt are given for industrial practitioners and researchers.

Letter to the Editor: Central Nervous System Involvement in Relapsing Polychondritis, a Rare and Difficult Diagnosis: a Case Report

Julien Le Marec,,Stéphanie Jobard,Adrien Bigot,Benjamin Terrier,Jean-Philippe Cottier,Frédéric Bastides,Elisabeth Diot 대한의학회 2017 Journal of Korean medical science Vol.32 No.6

Defining the optimal analgesic strategy for erector spinae plane (ESP) blocks in unanticipated open cholecystectomy

Julien Raft,Ki Jinn Chin,Quentin Gobert,Philippe Richebé,Véronique Brulotte 대한마취통증의학회 2019 Korean Journal of Anesthesiology Vol.72 No.5

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Correlation of palynofloras in the Tetori Province and consequences for the angiosperm invasion in East Asia

Julien Legrand,Toshihiro Yamada,Harufumi Nishida 대한지질학회 2017 대한지질학회 학술대회 Vol.2017 No.10

Foreign participation in emerging Asia's local currency debt markets and its links with bond yields

Julien Marcilly 인하대학교 정석물류통상연구원 2009 인하대학교 정석물류통상연구원 학술대회 Vol.2009 No.10

The recent financial market turmoil is a reminder of how strongly markets interrelate to one another and notably the significant impact that global risk appetite has on all (open) markets. Emerging Asia"s financial markets have been no exception and have suffered the perils of global market volatility and risk aversion over the past year. Local currency bond markets are part of this story. Within the context of the current crisis, the structural issue of how to manage foreign participation in domestic markets has taken on a new dimension for emerging Asia (and for that matter other emerging markets) given the noticeable surge in inflows to some of Asia"s local bond markets over the past years. Foreign capital inflows enable emerging countries to finance investment and foreign participation in local bond markets is seen as a way to accelerate the development of financial infrastructure. According to common beliefs, foreign investments have been a key driver of the recent downward trend in emerging market bond yields. Capital inflows, however, may create overheating and cause an appreciation of the real exchange rate impacting macroeconomic performance. In addition to this, in times of crisis (triggered by either local or global events) foreign capital flows may exit quickly resulting in financial instability. Foreign participation is thus often blamed for causing financial market volatility with periods of sharp inflows driving asset price bubbles and periods of sharp outflows accelerating asset price declines. It is difficult, however, to assess the precise extent to which foreign investments affect local markets dynamics. Against this backdrop, the goal of this paper is to empirically study the link between foreign investment in emerging Asia"s local currency debt markets and bond yields. The paper is structured as follows. Section 1 is the introduction. Section 2 documents recent trends in bond yields and in foreign investment activity in local currency bond markets of emerging Asia and consider the potential key explanatory factors linking the two. Section 3 summarizes the existing literature related to the effects of foreign participation on financial markets. Section 4 explains the empirical method applied in this paper and details the results of the VAR models and impulse responses. Section 5 concludes.

Original Surgical Treatment and Long-term Follow-up for Chronic Inflammatory Demyelinating Polyradiculoneuropathy Causing a Compressive Cervical Myelopathy: Review of the Literature

Julien Rigal,Emanuele Quarto,Lisa Boue,Laurent Balabaud,Wendy Thompson,Thibault Cloché,Stephane Bourret,Jean Charles Le Huec 대한척추신경외과학회 2022 Neurospine Vol.19 No.2

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a chronic relapsing disease of unknown aetiology. The diagnosis of this disease is still very complicated. The treatment is medical but, in some cases, a surgical decompression might be required. In rare cases it develops a radicular hypertrophy that can cause a cervical myelopathy; this pathology should be put in differential diagnosis with neurofibromatosis 1 and CharcotMarie-Tooth (CMT) syndromes. The cases of CIDP cervical myelopathy reported in the literature are rare and even more rarely a surgical decompression was described. Here we report a first and unique case of CIDP cervical myelopathy treated with an open-door laminoplasty technique with 10-year postoperative follow-up (FU). The surgical decompression revealed to be effective in stopping the progression of myelopathy without destabilizing the spine. The patient that before surgery presented a severe tetraparesis could return to walk and gain back his self-care autonomy. At 10-year FU he did not complain of neck pain and did not develop a cervical kyphosis. In case of cervical myelopathy caused by radicular hypertrophy, CIDP should be kept in mind in the differential diagnosis and an open-door laminoplasty is indicated to stop myelopathy progression.

Biological evaluation of the effect of sugammadex on hemostasis and bleeding

Julien Raft,Philippe Guerci,Valentin Harter,Thomas Fuchs-Buder,Claude Meistelman 대한마취통증의학회 2015 Korean Journal of Anesthesiology Vol.68 No.1

Background: Notification of sugammadex has been supplemented with a section on hemostasis, including a longer clottingtime in the first minutes following injection, without any documented clinical consequences. The objective of thisobservational study was to analyze the effects of sugammadex administration on routine coagulation tests and bleedingin the clinical setting. Methods: After Institutional Review Board approval, a prospective observational study was conducted between Januaryand December 2011. Adult patients scheduled for laparotomies were analyzed in groups according to the type of reversal(without sugammadex versus 2 or 4 mg/kg sugammadex). There were no changes in our current clinical practice. Blood samples drawn from these patients were standardized at the same time and tested using the same daily calibratedmachine. The endpoint was a comparison of the activated partial thromboplastin time (aPTT), prothrombin time (PT),hemoglobin (Hb) level and hematocrit (Ht), immediately before sugammadex administration (H0) and 1 h after neuromuscularblock reversal (H1). Results: One hundred and forty-two patients in three groups were included as follows: 11 in the “without sugammadex”group, 64 in the “2 mg/kg sugammadex” group and 67 in the “4 mg/kg sugammadex” group. Results did not differ significantlyamong the groups. Conclusions: In this prospective observational study, the use of 2 and 4 mg/kg sugammadex was not associated with alonger clotting time or decreased hemoglobin concentrations. Future prospective investigations should study patients receiving16 mg/kg sugammadex and/or with abnormal coagulation tests.