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Purpose: The purpose of this paper is to investigate ways to reduce the average amount of exceeded guaranteed service time for external trucks at Deepwater Container Terminal Gdańsk Sp z o.o. (DCT Gdańsk) via dosing the gate activities, in particular IN-Gate entry process, of trucks carrying import/export/transit containers. Design/methodology/approach: A Six Sigma methodology with the define, measure, analyze, improve, and Control (DMAIC) methods along with the SIPOC chart, cause and effect diagram, scatterplot, benchmark and brainstorming and finally multi-voting tool are used as analyses tools in this research. Findings: DCT Gdańsk reorganized and modernized the gate operations. Gate reorganization and modernization include streaming line traffic at the gates, external parking lot optimization, implementation of dedicated supporting software and installation of dedicated CCTV cameras to provide 24 h live view. During gates development, the external truck service times data were collected and analysed. The obtained materials concerned the measurement of the average truck turnaround time before and after the implementation of the improvements. Originality/value: The proposed approach of reducing the average amount of exceeded guaranteed service time of external trucks at the container terminal is unique and relatively cheap mainly due to organizational changes with some widely available low-cost investments and can be applied on a different scale to other container terminals or to transport and logistics companies. [ABSTRACT FROM AUTHOR]

The drainage gates have been controlled for desalination under normal conditions and flood defense in Saemangeum basin, Korea. Recently, it became an issue that the gates have been opened not to deteriorate water quality in the lake. It is, thus, necessary to precisely estimate the changes of water quality characteristics, especially DO, phosphate and nitrate, in the lake according to various gate operations. In this study, Semi-implicit Cross-scale Hydroscience Integrated System Model and Carbon, Silicate, Nitrogen Ecosystem model (SCHISM-CoSiNE) which is cable to simulate dynamic exchange such as gate operation conditions was utilized to obtain reliable and reasonable results including hydrodyanamic and environmental variables. For the verification, the measured data at 6 locations in Saemangeum basin was used to compare incluidng temperatue and salintiy from 2016 and each relative error became small enough to show high accurary. Also, under various scenarios by changing the designated water surface elevation on flood seasons, this model has been applied to present the best designated water surface elevation in terms of both water quality and water supply in the Saemangeum basin. It becomes possbile to show reliable guidance for dynamic operations and environmental changes with this model as requested in near future. [ABSTRACT FROM AUTHOR]

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Pump stations prevent backwater effects from urban streams and safely drain rainwater in urban areas. Urbanization has increased the required capacity of centralized reservoirs and drainage pumps; yet, their respective designs are based on the runoff of the target watershed at the time of design. In Korea, additional pump stations are constructed to supplement the insufficient capacity of centralized reservoirs and drainage pumps. Two pump stations in the same drainage area share centralized reservoirs, and there are gates between them. Operation of the gates and drainage pumps is based on the water level in the connected centralized reservoirs. The convertible operation is based on changes in flow between two pump stations with different effluent streams in shared centralized reservoirs. Efficient distribution of inflow to both pump stations provides additional storage capacity in centralized reservoirs and rapid drainage. For a rainfall event in 2010, flooding volumes for current and convertible operations were 58,750 and 7507 m³, respectively. For an event in 2011, the corresponding figures were 3697 and 471 m³. This shows that resilience increased by 0.10829 and 0.00756, respectively, for the two events. Accordingly, a new technique to operate multiple pump stations for reducing urban inundation is proposed. [ABSTRACT FROM AUTHOR]

Construction of river diversion barrages produces a shallow reservoir, called the pond, which is used more often for flow balancing between the inflows of the river and the outflows of the off-taking canal. However, deposition of sediment in the pond due to the relatively low velocities reduces the pond capacity. The current study investigates the effectiveness of gate operation and variations of other parameters in flushing out these sediment mounds, or shoals, from the barrage pond. Data from laboratory experiments on a scaled model of a prototype barrage is used to train and test different Artificial Neural Network (ANN) models of the system. The models map the relationship between flushing efficiency of a sediment shoal from the upstream of a barrage, and the parameters river discharge, barrage pond depth and area of gate opening, position of the sediment shoal with respect to the barrage. The ANN models are then used to study the effect of different parameters on the sediment flushing efficiency. Apart from river discharge and net area of gate opening, upstream pond depth is also found to have a significant effect on flushing efficiency, with a general trend of decrease in efficiency with increase in pond depth becoming apparent. Efficacy of different gate opening pattern is also tested, with the 'inverted arch' gate opening pattern proving to be the most efficient when compared with 'arch' and 'uniform' gate opening. [ABSTRACT FROM AUTHOR]

The Seonakdong River is an impound stream whose flowrate is controlled by the Daejeo and Noksan gates. Therefore, constant natural flow of the Seonakdong River does not occur. In contrast, pollutant loadings occur constantly occurring as water flows into the river from the watershed. The Daejeo gate is located at the upstream head and the Noksan gate is at the downstream end of the Seonakdong River. The Seonakdong River is an estuarine tributary of the Nakdong River. It is a reservoir-like river used for agricultural irrigation, with the Noksan gate at the river mouth serving to prevent the intrusion of saline water. In this study, a steadystate model, QUAL2E, and an unsteady-state model, CE-QUAL-RIV1, were chosen for comparative simulations. The results of the simulations of river water quality changes were verified with respect to short-term variations of water quality due to the increasing water flow from the Daejeo gate and the discharging flow from the Noksan gate. Field measurements were performed to monitor the flowrate and water quality during the operation of the Daejeo and Noksan gates in the Seonakdong River. The general trend observed is that the water quality worsens after the opening of the gates. The reduction in water quality ranges from 3% to 38%. These results show that the gate operators should carefully select the most appropriate operating plan to obtain better water quality in the Seonakdong River. The numerical simulation shows that a discharge of 300 CMS, which is a peak inflow from the Daejeo water gate to the river, can make it possible to achieve the target water quality of the Seonakdong River if the Daejeo water gate can remain open in connection with the Noksan water gate operation. [ABSTRACT FROM AUTHOR]

In this paper the measure of increased river base flow is developed and evaluated. Aim is the temporal increase of flow in manmade low flow stretches for sufficient dilution of downstream acute pollution introduced by combined sewer overflows (CSOs). The increase of flow is done by operating upstream located retaining structures such as hydropower intakes. For implementation both energy producers and municipalities are required to cooperate. Thus the measure fits into a core aim of the Water Framework Directive of having basin wide approaches for improvements. Technically the focus of the measure is clearly on the mitigation of acute pollution, not addressing delayed or accumulate pollutants. The framework and implications are discussed for having an appropriate real time control (RTC) concept based on model based predictive control (MBPC). A specially development algorithm for the operation is presented and subsequently tested off-line with a semi-virtual catchment. The boundary conditions of the catchment are varied with regard to the connected catchment size, the river connected and the pollutant concentration originating from the catchment. Based on these scenarios and a review on uncertainties in rain forecasts, limits for the measure are derived. Costs for the measure were estimated as equivalent cost due to losses in energy production. It is shown that not only the costs for annual spilled water are to be considered but as well peak flows generated in the river system. The increase of CSO volume as an alternative measure was not found to be a suitable measure, leading to unrealistic high volumes and consequently to exorbitant costs. [ABSTRACT FROM AUTHOR]

In river stretches being subjected to flow regulation, usually for the purpose of energy production (e.g. Hydropower) or flood protection (river barrage), a special measure can be taken against the effect of combined sewer overflows (CSOs). The basic idea is the temporal increase of the river base flow (during storm weather) as an in-stream measure for mitigation of CSO spilling. The focus is the mitigation of the negative effect of acute pollution of substances. The measure developed can be seen as an application of the classic real time control (RTC) concept onto the river system. Upstream gate operation is to be based on real time monitoring and forecasting of precipitation. The main objective is the development of a model based predictive control system for the gate operation, by modelling of the overall wastewater system (incl. the receiving water). The main emphasis is put on the operational strategy and the appropriate short-term forecast of spilling events. The potential of the measure is tested for the application of the operational strategy and its ecological and economic feasibility. The implementation of such an in-stream measure into the hydropower's operational scheme is unique. Advantages are (a) the additional in-stream dilution of acute pollutants entering the receiving water and (b) the resulting minimization of the required CSO storage volume. [ABSTRACT FROM AUTHOR]

All-optical switching characteristics of waveguide devices having a nonlinear distributed feedback structure are reported theoretically and experimentally. These devices were composed of a strip-loaded GaInAsP-InP waveguide and a Bragg reflector, which were suitable for optical integrated circuit. In the experiments, all-optical and gate operation and set-reset operation for two output ports were successfully demonstrated [ABSTRACT FROM PUBLISHER]

Yoo, H.J.; Kim, D.H.; Park, M.H., and Lee, S.O., 2021. Economic sediment transport control with sediment flushing curves for sea dike gate operation: Case study in Saemangeum Basin, Korea. In: Lee, J.L.; Suh, K.-S.; Lee, B.; Shin, S., and Lee, J. (eds.), Crisis and Integrated Management for Coastal and Marine Safety. Journal of Coastal Research, Special Issue No. 114, pp. 161–165. Coconut Creek (Florida), ISSN 0749-0208. As the major reclamation works in Korea, the sea dikes have been installed for preventing the saltwater intrusion in Saemangeum Basin connected with Mangyeonggang and Dongjingang River, Korea since 2010. Recently, the sedimentation issues near the gates due to change of flow velocity might induce serious problems such as water pollution, local scour, stability of hydraulic structures linked with dike. We focused that the gate operation rule was changed to alleviate the sediment transport problem by altering the management water surface elevation in this study. The 3D numerical model, SCHISM, was used to simulate the sediment transport under the gate operation rule which was embedded after modifying the hydraulics structure module in SCHISM. The numerical model was verified by comparing with the measured data in the literature. It was found that the phenomenon induced by gate operation was accurately simulated to compare with the field measurements from Korea Rural Community Corporation (KRCC). Based on the results of SCHISM, the Best Management Practices on gate operation were examined and suggested the optimal solution in terms of structural stability and water use including water quality. [ABSTRACT FROM AUTHOR]

In order to cover the crop water requirements, flow control structures such as gates and weirs are used to transfer the desired amount of water from the canals to the field canals. This paper examines the impact of gate operation and the selection of gates on the deposition of non-cohesive sediment. The Delft3D model is used to simulate the effects of different scenarios regarding gate operation and the location of the gate that is opened. The model results showed that the gate selection affects not only hydraulic parameters but also morphological parameters. It was found that opening the gates closer to the offtake resulted in less sediment deposition at the entrance of the branch canal when compared to opening the gates further away. Gate selection can be used as a tool in sediment management. By alternating the opening of different gates sediments that are already deposited after opening one gate can be eroded when another gate is operated, thus minimizing the additional cost of sediment removal. The use of Delft3D proved beneficial as the selection of different gates leads to asymmetric sediment deposition patterns which would be missed when using a 1D model. [ABSTRACT FROM AUTHOR]

This study examines an innovative Coastal Reservoir (CR) technique as a feasible solution for flood adaptation and mitigation in the Brisbane River Estuary (BRE), Australia, which is vulnerable to coastal flooding. The study analysed the operation of a CR by using the MIKE 21 hydrodynamic modelling package. The 2D hydrodynamic model was calibrated and validated for the 2013 and 2011 flood events respectively, with a Nash-Sutcliffe coefficient (Ens) between 0.87 to 0.97 at all gauges. River right branch widening and dredging produced a 0.16 m reduction in water level at the Brisbane city gauge. The results show that by suitable gate operation of CR, the 2011 flood normal observed level of 4.46 m, with reference to the Australian Height Datum (AHD) at Brisbane city, could have been reduced to 3.88 m AHD, while under the improved management operation of the Wivenhoe Dam, the flood level could be lowered to 4 m AHD at Brisbane city, which could have been reduced with CR to 2.87 m AHD with an overall water level reduction below the maximum flood level. The results demonstrated that the innovative use of a CR could considerably decrease the overall flood peak and lessen flood severity in the coastal city of Brisbane. [ABSTRACT FROM AUTHOR]

Sediments cause serious problems in irrigation systems, adversely affecting canal performance, driving up maintenance costs and, in extreme cases, threatening system sustainability. Multiple studies were done on the deposition of non-cohesive sediment and implications for canal design, the use of canal operation in handling sedimentation problems is relatively under-studied, particularly for cohesive sediments. In this manuscript, several scenarios regarding weirs and gate operation were tested, using the Delft3D model, applied to a case study from the Gezira scheme in Sudan. Findings show that weirs play a modest role in sedimentation patterns, where their location influences their effectiveness. On the contrary, gate operation plays a significant role in sedimentation patterns. Reduced gate openings may cause canal blockage while intermittently fully opening and closing of gates can reduce sediment deposition in the canal by 54% even under conditions of heavy sediment load. Proper location of weirs and proper adjusting of the branch canal's gate can substantially reduce sedimentation problems while ensuring sufficient water delivery to crops. The use of 2D/3D models provides useful insights into spatial and temporal patterns of deposition and erosion but has challenges related to running time imposing a rather coarse modelling resolution to keep running times acceptable. [ABSTRACT FROM AUTHOR]