72 research outputs found
The EUâs Trade Policy in the Doha Development Agenda â An Interim Assessment on Rules Negotiations
At Doha Ministerial Conference in 2001, WTO members agreed to launch new trade negotiations on a range of subjects and other work, including issues concerning the implementation of the present agreements. Various issues in the WTO Doha Development Agenda were dealt with in the form of âsingle undertakingâ which include the trade remedy rules, i.e., anti-dumping and subsidies rules. The EU, being the largest regional economy in the world, was no doubt a heavyweight in the Doha multilateral trade negotiations and so was its trade policy of great weight. To date, the EU had put forward a total of 10 submissions to clarify and improve the AD Agreement and the SCM Agreement at the end of 2006, and the submissions revealed the EUâs attitude toward the Rules negoation; not aggressive but prudent and cautious. While Doha Round seemed doomed and gloomy, the EU, on the other hand, launched its new trade policy, the âGlobal Europeâ framework in 2006 pursuant to the goals set up by the conclusions of Lisbon European Council. The new EUâs trade policy is comprised of a wider array of trade issues, aiming at maintaining its global competitiveness, and in light of the growing fragmentation and complexity of the process of production and supply chains as well as the growth of major new economic actors, particularly in Asia, there was a need for a revision of the EU Trade Defence Instruments (TDI) . A âGreen Paperâ on TDI was thus drafted and presented for public consultation by the Commission at the end of 2006, which is intended to make sure EU TDI fit in the trend of globalization as well as the European multinational corporations' competiveness in the new economic context. This paper intends to explore if the possible trade policy adjustment in the EU TDI will also facilitate to resolve the discrepancy between the EU and its counterparts in the Rules negotiations and provide a solid basis for the conclusion thereof. Section II of the article presents the ongoing DDA negotiations, inter alia, Rules negotiations. Section III will probe the negotiation objective and issues that EU concern by examining its submissions to the Negotiating Group on Rules as well as its implementation assessment. The EUâs new trade policy, in particular, that on the newly released âGreen Paperâ on the TDI will also be analyzed in section IV. This paper concludes that the EU policy on TDI is expected to be adjusted toward a framework favorable to other economic operators, such as users and consumers. Whether the public consultation for âGreen Paperâ is a process of consensus building is still an argument. It is likely that EU delegate will narrow down the gap between the EU and other exporting-oriented members in the Rules negotiations should the revised TDI be expanded to a large extent
A conceptual river model to support real-time flood control (Demer River, Belgium)
River engineeringFlow management and contro
Model Predictive Control Combined With Genetic Algorithms For A River System
Flood is one of the natural disasters. It frequently causes costly economic losses and numbers of lives come to harm. Due to these severe injuries, how to perform an effective flood control is always a huge challenge for governments and water authorities. In order to establish successful flood control strategies to prevent or alleviate flood damages, besides implementing operating rules (regulations) established by water authorities for the hydraulic structures, applying real time optimization-based control strategies is a supplementary tool for water managers to make decisions. It is expected that the importance of such real time control strategies will become more important in the future. It is an ideal adaptation strategy in a world that is rapidly changing, for instance due to urbanization and climate trends. Real time control indeed allows making more efficient use of existing storage capacity available in flood control reservoirs. In order to accelerate the large number of iterations concerning the hydraulic computations in optimization procedures, a simplified river conceptual model was developed and connected to a Model Predictive Control (MPC) algorithm. This tool was applied to determine efficient real-time flood control policies for the 12 gated-weirs in the Belgian case study of the river Demer around two main flood control reservoirs. Because the system dynamics are nonlinear (gate openings are considered as inputs in the MPC), the MPC was combined with Genetic Algorithms (GAs) to cope with the nonlinear problems. The MPCGA model searches for better control actions by minimizing the cost function while at the same time avoiding violation of the defined constraints. The optimization results testify that MPCGA is capable of improving of the current regulation strategy that is based on fixed regulation rules and three-point controllers
Women with endometriosis have higher comorbidities: Analysis of domestic data in Taiwan
AbstractEndometriosis, defined by the presence of viable extrauterine endometrial glands and stroma, can grow or bleed cyclically, and possesses characteristics including a destructive, invasive, and metastatic nature. Since endometriosis may result in pelvic inflammation, adhesion, chronic pain, and infertility, and can progress to biologically malignant tumors, it is a long-term major health issue in women of reproductive age. In this review, we analyze the Taiwan domestic research addressing associations between endometriosis and other diseases. Concerning malignant tumors, we identified four studies on the links between endometriosis and ovarian cancer, one on breast cancer, two on endometrial cancer, one on colorectal cancer, and one on other malignancies, as well as one on associations between endometriosis and irritable bowel syndrome, one on links with migraine headache, three on links with pelvic inflammatory diseases, four on links with infertility, four on links with obesity, four on links with chronic liver disease, four on links with rheumatoid arthritis, four on links with chronic renal disease, five on links with diabetes mellitus, and five on links with cardiovascular diseases (hypertension, hyperlipidemia, etc.). The data available to date support that women with endometriosis might be at risk of some chronic illnesses and certain malignancies, although we consider the evidence for some comorbidities to be of low quality, for example, the association between colon cancer and adenomyosis/endometriosis. We still believe that the risk of comorbidity might be higher in women with endometriosis than that we supposed before. More research is needed to determine whether women with endometriosis are really at risk of these comorbidities
First Sagittarius A* Event Horizon Telescope results. II. EHT and multiwavelength observations, data processing, and calibration
We present Event Horizon Telescope (EHT) 1.3 mm measurements of the radio source located at the position of the supermassive black hole Sagittarius A* (Sgr A*), collected during the 2017 April 5â11 campaign. The observations were carried out with eight facilities at six locations across the globe. Novel calibration methods are employed to account for Sgr A*'s flux variability. The majority of the 1.3 mm emission arises from horizon scales, where intrinsic structural source variability is detected on timescales of minutes to hours. The effects of interstellar scattering on the image and its variability are found to be subdominant to intrinsic source structure. The calibrated visibility amplitudes, particularly the locations of the visibility minima, are broadly consistent with a blurred ring with a diameter of âŒ50 ÎŒas, as determined in later works in this series. Contemporaneous multiwavelength monitoring of Sgr A* was performed at 22, 43, and 86 GHz and at near-infrared and X-ray wavelengths. Several X-ray flares from Sgr A* are detected by Chandra, one at low significance jointly with Swift on 2017 April 7 and the other at higher significance jointly with NuSTAR on 2017 April 11. The brighter April 11 flare is not observed simultaneously by the EHT but is followed by a significant increase in millimeter flux variability immediately after the X-ray outburst, indicating a likely connection in the emission physics near the event horizon. We compare Sgr A*'s broadband flux during the EHT campaign to its historical spectral energy distribution and find that both the quiescent emission and flare emission are consistent with its long-term behavior.http://iopscience.iop.org/2041-8205Physic
First Sagittarius A* Event Horizon Telescope Results. II. EHT and Multiwavelength Observations, Data Processing, and Calibration
We present Event Horizon Telescope (EHT) 1.3 mm measurements of the radio source located at the position of the supermassive black hole Sagittarius A* (Sgr A*), collected during the 2017 April 5â11 campaign. The observations were carried out with eight facilities at six locations across the globe. Novel calibration methods are employed to account for Sgr A*'s flux variability. The majority of the 1.3 mm emission arises from horizon scales, where intrinsic structural source variability is detected on timescales of minutes to hours. The effects of interstellar scattering on the image and its variability are found to be subdominant to intrinsic source structure. The calibrated visibility amplitudes, particularly the locations of the visibility minima, are broadly consistent with a blurred ring with a diameter of âŒ50 ÎŒas, as determined in later works in this series. Contemporaneous multiwavelength monitoring of Sgr A* was performed at 22, 43, and 86 GHz and at near-infrared and X-ray wavelengths. Several X-ray flares from Sgr A* are detected by Chandra, one at low significance jointly with Swift on 2017 April 7 and the other at higher significance jointly with NuSTAR on 2017 April 11. The brighter April 11 flare is not observed simultaneously by the EHT but is followed by a significant increase in millimeter flux variability immediately after the X-ray outburst, indicating a likely connection in the emission physics near the event horizon. We compare Sgr A*âs broadband flux during the EHT campaign to its historical spectral energy distribution and find that both the quiescent emission and flare emission are consistent with its long-term behavior
Flood Control Combining Optimization Techniques with Hydrologic-Hydraulic Modelling
Flood is one of the natural disasters. It frequently causes vast amount of economic losses and other consequences (social, ecological), even losses of human lives. Due to these severe injuries, how to perform an effective flood control is always a huge challenge for governments and water authorities. In Belgium, the river Demer has its history to be viewed as a definite case for discussing flood problems. In the past, flooding along this river could not be prevented during several periods of heavy rainfall events. In order to alleviate such flood disasters, the Flemish Environment Agency (Vlaamse Milieumaatschappij, VMM) installed several hydraulic structures (e.g. movable gated weirs and flood reservoirs) and formulated operating rules to regulate them. After that, the VMM water authority is able to reduce or limit the flood hazard. It can, however, not fully avoid the most extreme flood events. A complete real-time flood control scheme has the ability to integrate weather prediction, flood simulation and optimization models. Due to these characteristics, it is expected to be more advantageous than current logical operating rules (three-position controller) to handle severe rainfall events. Therefore, this dissertation investigates the applicability of an advanced control strategy by means of Model Predictive Control (MPC), and discusses its potential performance for the flood mitigation of the Demer river system.
Developing a suitable river flood model is a must for this research. Firstly, a detailed full hydrodynamic model, InfoWorks-RS model, was applied to simulate the detailed physically-based hydrodynamic processes for open channels, floodplains, embankments and hydraulic structures of the river networks. However, one of the main problems to date is that such detailed full hydrodynamic model has very long computational times. Especially the model-supported real-time flood control requires effective and efficient hydraulic computations as large numbers of iterations are to be executed in optimization procedures. A conceptual model can resolve this problem. By means of the simulation results of the detailed full hydrodynamic model, an identification and calibration procedure was developed in this study for the purpose of having a conceptual model built up and calibrated based on a limited number of simulations with a more detailed full hydrodynamic model. The conceptual river model aimed to concisely describe the system dynamics and responses during different flow conditions with high accuracy (consistent and close to the detailed full hydrodynamic InfoWorks-RS model) and at high speed. It is found that the conceptual river model is capable of accomplishing simulation of historical flood events with high statistical performances (Nash-Sutcliffe Efficiency values higher than 0.90) within few seconds. It is much faster than the detailed full hydrodynamic model, which enables the conceptual model to be applied for real-time flood control.
The upstream and lateral inflow discharges of both the detailed hydrodynamic model are calculated by a rainfall-runoff model, more specifically the Probability Distributed Model (PDM). PDM was implemented for the different subcatchments of the river Demer basin.
For the final goal of this research, improved gate-operation policies (gate crest levels as optimization variables) are searched for flood events through large number of iterations, which are run by an optimization model. The approach was principally to develop a procedure for the real-time optimal control of the hydraulic structures. This required comprehending the whole procedure for such control, making use of the technique of MPC and learning how to link it with the conceptual model. In addition to the MPC algorithm, an adequate MPC-based optimization technique had to be selected, which can cope with the strongly dynamic and nonlinear dynamics of the process model in real time at each sampling instant (e.g. 5 minutes). A Genetic Algorithm (GA) was selected as optimization method for this study, and combined with MPC that enables to cope with the nonlinear dynamics. The MPCGA model searches for better control actions by minimizing the cost function while at the same time avoiding violation of the defined constraints. The optimization results testify that MPCGA is capable of improving of the current regulation strategy that is based on fixed regulation rules and three-point controllers.
In summary, this research concludes that real-time flood control can be carried out successfully by connecting the conceptual hydrologic-hydraulic model with the nonlinear MPC optimized by a GA. A concrete procedure for real-time flood control is built up and demonstrated/evaluated for the river Demer case by comparing with the current regulation strategy. It is shown for the extreme September 1998 flood that the better control policies found by the MPCGA controller succeed to keep all twenty selected/monitored water levels beneath their corresponding flood levels, and solve the flood damages that occur when the three-position controller is in place at 3 locations. This study hence has shown that the advanced real-time control procedure developed in this research succeeds to mitigate negative/harmful flood conditions along a river system.nrpages: 255status: publishe
Model predictive control combined with Genetic Algorithms for a river system
Real time flood control becomes more widely applied given its features to make more efficient use of existing storage capacity available in flood control reservoirs. In order to accelerate the large number of iterations concerning the hydraulic computations in optimization procedures, a simplified river conceptual model was developed and connected to a Model Predictive Control (MPC) algorithm. This tool was applied to determine efficient real-time flood control policies for the 12 gated-weirs in the Belgian case study of the river Demer around two main flood control reservoirs. Because the system dynamics are nonlinear (gate openings are considered as inputs in the MPC), the MPC was combined with Genetic Algorithms (GAs) to cope with the nonlinear problems. The MPCGA model searches for better control actions by minimizing the cost function while at the same time avoiding violation of the defined constraints. The optimization results testify that MPCGA is capable of improving the current regulation strategy that is based on fixed regulation rules and three-point controllers.status: publishe
Model conceptualization procedure for river (flood) hydraulic computations: Case study of the Demer River, Belgium
Model-supported real-time flood control requires the development of effective and efficient hydraulic models. As large numbers of iterations are to be executed in optimization procedures, the hydraulic model needs to be computationally efficient. At the same time, it is also required to generate high-accuracy results. Therefore, an identification and calibration procedure was developed for the purpose of having this conceptual model built up and calibrated based on a limited number of simulations with a more detailed full hydrodynamic model. The performance of the conceptual model was evaluated for historical events under different regulation conditions. Robustness test results show close agreement, with Nash-Sutcliffe Efficiency values higher than 0.90. In addition, it is found that the conceptual model is capable of accomplishing simulation of historical flood events within few seconds. That is much faster than the detailed full hydrodynamic model, which enables the conceptual model to be applied for real-time flood control.status: publishe
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