scholarly journals Evaluating joint operation rules for connecting tunnels between two multipurpose dams

2020 ◽  
Vol 51 (3) ◽  
pp. 392-405
Author(s):  
Ji-Woo Jeong ◽  
Young-Oh Kim ◽  
Seung Beom Seo

Abstract This study aims to provide a practically efficient approach for determining the most efficient joint operation rule for two reservoirs connected by a waterway tunnel. For this purpose, the connecting tunnel's effect was assessed and three heuristic joint operation rules accounting for the connecting tunnel were evaluated. A standard operation policy with the connecting tunnel led to positive effects on the water resource system of the target basin with regard to a reliable water supply. The connecting tunnel provides an additional water supply of 12.4 million m3/year to the basin, and the reliability of the two reservoirs increased. Among the three rules, the equivalent reservoir (ER) rule led to the most positive effect on water supply. We found that the ER rule could maximize the positive effects of the connecting tunnel by maintaining the effective water storage rates of the two reservoirs. Moreover, the effects of hydrologic uncertainty on the joint operation rules were discussed using the synthetically generated multiple streamflow traces.

2014 ◽  
Vol 14 (6) ◽  
pp. 1160-1167 ◽  
Author(s):  
Haixia Wang ◽  
Jinggang Chu ◽  
Chi Zhang ◽  
Huicheng Zhou

This paper investigates the influences of reservoir water level variations of the operation rule curves on different objectives, especially on ecological objectives. Five representative ecological objectives are selected besides industrial and domestic (I&D) and agricultural water supply objectives. They can reflect the impacts of reservoir operation on different attributes of ecological flow regime in the Biliuhe Reservoir case study, Northeastern China. Sensitivities of water supply and ecological objectives caused by water level variations of I&D and agricultural operation rule curves are analyzed by using a variance-based sensitivity analysis method – Sobol's method. Results show that impacts of individual water levels and their interactions on ecological objectives are very different. Also the ecological objectives do not always conflict with water supply objectives. This study provides new insights for reservoir managers to improve downstream aquatic ecosystem by adjusting water levels not only at individual time periods but also at some interacting time periods. Furthermore, it helps us better understand the influence mechanism of water level changes on different objectives, and provides guidance for the development of reservoir operation rules.


Land Science ◽  
2020 ◽  
Vol 2 (1) ◽  
pp. p21
Author(s):  
Mohammed Jiya Mamman ◽  
Otache Y Matins

Resilience may be defined as a yardstick that specifies the extent a reservoir recuperates when it fails previously. A reliable water resource system speedily returns to an acceptable state after a failure. Vulnerability measures severity or extent of failures or letdowns, if and once they occur. Sustainability index (SI) provides a sign of fundamental nature with respects to probable unwanted repercussions if imbalance of waters occurs. Sustainability index (SI) can also be expressed as a mean of reliability, resilience and vulnerability. This study employs commonly used indices (reliability, resilience, and Vulnerability) to assess the performance of Kainji reservoir system. To attain this, rain fall and river flow data were obtained from Kainji Hydrological station in New Bussa Nigeria. Analysis using MAKESENS software was used on the rainfall and river flows to look at the extreme events. In order to determine the performance of the reservoir system some reservoir performance indices were employed, these are; vulnerability, resilience, and sustainability index. This is achieved by adopting relevant existing equations. Reservoir flows and storages ware employed, different draft ratios were considered (0.3- 1.0). Varying demand levels were also chosen (0 – 0.8) as against the coefficient of variation to look at the monotonic behaviour of resilience against the various levels of demand. Volume reliability falls repeatedly as draft/ MAR upsurges and bigger values were attained as S/MAR rises. The analysis on the reservoir shows that as demand decreases the sustainability increases and also the higher the storage ratio the higher the sustainability index. It also shows that as draft ratio increases the resilience decreases, and because the draft ratio decreases the resilience increases. The reservoir system was classified as within year system, which suggests high resilience, less vulnerable and sustainable. The operation rule shows the need for optimization.


2021 ◽  
Vol 21 (6) ◽  
pp. 369-375
Author(s):  
Sijung Choi ◽  
Seongkyu Kang ◽  
Dongryul Lee

The Daap intake plant located downstream of the Seomjin River was relocated in 2005, and the amount of intake increased. Accordingly, it significantly influenced the change in the flow rate downstream of the Seomjin River. After relocating the Daap intake plant, the production of Corbicula in the downstream of the Seomjin River decreased; there is a demand for investigation into the damage to the downstream fishermen and preparation of countermeasures. An increase in instream flow to increase the production of Corbicula downstream of the Seomjin River may cause difficulties in the stable water supply of the Seomjin River basin; therefore, a preliminary review is necessary. In this study, the supply stability was evaluated through water budget analysis after setting several instream flow at the downstream of the Seomjin River in Gurye-gun (Songjeong-ri). In addition, the supply stability of the water resource system in the Seomjin River according to the instream flow rate was evaluated. It was intended to suggest an alternative to the supply of instream flow. If the instream flow is set large to increase the production of Corbicula, it may cause difficulties in supplying instream flow and problems in supplying water necessary for human activities; therefore, related information must be provided through various analyses.


2019 ◽  
Vol 3 (4) ◽  
pp. 209-222
Author(s):  
Philipp K. Görs ◽  
Henning Hummert ◽  
Anne Traum ◽  
Friedemann W. Nerdinger

Digitalization is a megatrend, but there is relatively little knowledge about its consequences for service work in general and specifically in knowledge-intensive business services (KIBS). We studied the impact of digitalization on psychological consequences for employees in tax consultancies as a special case of KIBS. We compare two tax consulting jobs with very different job demands, those of tax consultants (TCs) and assistant tax consultants (ATCs). The results show that the extent of digitalization at the workplace level for ATCs correlates significantly positively with their job satisfaction. For TCs, the same variable correlates positively with their work engagement. These positive effects of digitalization are mediated in the case of ATCs by the impact on important job characteristics. In the case of TCs, which already have very good working conditions, the impact is mediated by the positive effect on self-efficacy. Theoretical and practical consequences of these results are discussed.


2021 ◽  
Vol 13 (15) ◽  
pp. 8633
Author(s):  
Yuhan Ge ◽  
Qing Yuan ◽  
Yaxi Wang ◽  
Keunsoo Park

In today’s increasingly competitive coffee industry, the point of running a good coffee shop is no longer to run a coffee and beverage shop simply, but to focus on the quality of service and the value that customers feel as a result. Previous studies have mainly discussed the customer satisfaction and behavioral intention of restaurants, while few studies have explored the influencing factors of customer satisfaction and behavioral intention of chain coffee shops. Given that the perceived service quality theory and DINESERV model can effectively predict customer satisfaction and behavioral intention, this study took 385 consumers in the first Starbucks Reserve flagship store in China as survey objects. SmartPLS 3.0 software was used to explore the relationship among respondents’ perceived service quality, customer perceived value, satisfaction, and behavioral intention. The results show that service quality has a partially significant positive effect on perceived value. Perceived service quality and customers’ perceived value both have significant positive effects on satisfaction. Customers’ satisfaction has a significant positive effect on their behavioral intention. These results indicate that enterprises should strengthen the emotional bond between consumers and enterprises and improve the reliability, assurance, and empathy of perceived service quality to create a better emotional resonance between consumers and the Starbucks brand to improve customer satisfaction. At the same time, it should also promote the symbolic perceived value of Chinese consumers to Starbucks to realize the sustainable development of coffee-shop operation and consumer repurchase. This study expands the research on the service quality, perceived value, and behavioral intention of coffee chain enterprises in the context of non-habitual coffee-drinking countries. Moreover, it provides case support for the operation and research of regional cultural consumption habits of international catering chain enterprises.


2021 ◽  
Vol 13 (2) ◽  
pp. 579
Author(s):  
Caroline Reimann ◽  
Fernando Carvalho ◽  
Marcelo Duarte

The present investigation aims study the sustainability of the business model of the Portuguese SMEs operating in the B2B International market analyzing the influence of dynamic marketing capabilities and adaptive marketing capabilities in their international marketing performance. It will also analyze the moderating effects of Competitive Intensity within this international scenario. A quantitative study was developed, using a questionnaire as a research method. In total, 335 valid responses were collected from Portuguese SMEs in June 2020. To test the hypotheses, multiple hierarchical regressions were performed. As for the analyzes involving Competitive Intensity environments, namely low and high intensity, dummies were developed to evaluate the different effects produced by the capacities in the International Marketing Performance. This study shows the positive impact of the dynamic marketing capabilities and adaptive marketing capabilities on the international marketing performance of the surveyed companies, essentially from the product development management, supply chain management, vigilant market learning and open marketing. when in a low competitive intensity environment only dynamic marketing capabilities had a positive effect on performance, but in a high, competitive, intensity environment both dynamic marketing capabilities and adaptive marketing capabilities showed positive effects in relation to performance. This study innovates by bringing international marketing, through two marketing capacities, from the perspective of SMEs that perform B2B activities.


Animals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1132
Author(s):  
Sarah Schwarzkopf ◽  
Asako Kinoshita ◽  
Jeannette Kluess ◽  
Susanne Kersten ◽  
Ulrich Meyer ◽  
...  

Development of calves depends on prenatal and postnatal conditions. Primiparous cows were still maturing during pregnancy, which can lead to negative intrauterine conditions and affect the calf’s metabolism. It is hypothesized that weaning calves at higher maturity has positive effects due to reduced metabolic stress. We aimed to evaluate effects of mothers’ parity and calves’ weaning age on growth performance and blood metabolites. Fifty-nine female Holstein calves (38.8 ± 5.3 kg birth weight, about 8 days old) were used in a 2 × 2 factorial experiment with factors weaning age (7 vs. 17 weeks) and parity of mother (primiparous vs. multiparous cows). Calves were randomly assigned one of these four groups. Live weight, live weight gain and morphometry increased over time and were greater in calves weaned later. Metabolic indicators except total protein were interactively affected by time and weaning age. Leptin remained low in early-weaned calves born to primiparous cows, while it increased in the other groups. The results suggest that weaning more mature calves has a positive effect on body growth, and calves born to primiparous cows particularly benefit from this weaning regimen. It also enables a smooth transition from liquid to solid feed, which might reduce the associated stress of weaning.


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