Comparative Evaluation on Performance Characteristics of an Impact Sprinkler with Nozzle-Dispersion Devicesand Rotary Plate Sprinkler

2020 ◽  
Vol 36 (3) ◽  
pp. 321-329
Author(s):  
Hong - Hong ◽  
Yue - Jiang ◽  
Pan - Tang ◽  
Chao - Chao ◽  
Alexander - Fordjour
Keyword(s):  
Performance Indicators ◽  
Comparative Evaluation ◽  
Water Distribution ◽  
Low Pressure ◽  
Comparative Performance ◽  
Droplet Distribution ◽  
Spacing Factor ◽  
Jet Breakup ◽  
Rotary Plate ◽  
Better Than

Abstract. A set of nozzle and water dispersion devices were designed to obtain a desirable jet breakup and save water from an impact sprinkler (IS) at low pressure conditions. Comparative performance indicators were obtained for the commercial LP and IS sprinkler heads. Results show that under the same working conditions, the IS produced a large spray range and the water distribution in the middle of the spray range (R) was better than the LP. The best simulated uniformity from the IS was obtained for the combined spacing factor of 1.4*R and the combined uniformity was 4% larger than the LP. Considering the middle position of the spray range, the number and diameter of the droplets from the IS were larger than the droplets from the LP. However, in the end position of the spray range, the droplet diameters from the IS were quite smaller than the LP. Velocities from IS ranged between 0.2 and 6.4 m/s, while that from LP sprinkler were slightly higher ranging from 0.15 to 7.7 m/s at 150 kPa. Overall, introduction of the fixed dispersion device with a pointed tip profile combined with the 6 mm nozzle offered some advantages for the IS over the LP sprinkler at low-pressure conditions. Keywords: Dispersion device, Droplet distribution, Impact sprinkler, Low pressure sprinkler, Nozzle, Spray range, Uniformity.

SME’s Performance Through Comparative Performance Indicators, Measured by Business Statistics- Albania Case

2017 ◽  
Vol 9 (1) ◽  
pp. 361
Author(s):  
Godiva Rembeci
Keyword(s):  
Economic Performance ◽  
National Economy ◽  
Performance Indicators ◽  
Future Research ◽  
Productivity Measurement ◽  
Comparative Performance ◽  
Global Consensus ◽  
Research Activities ◽  
Business Statistics ◽  
National Economies

Now days there is a global consensus among all stakeholders that SMEs represent a driving force to the overall economic development, due to their significant contribution both on GDP and employment of national economies. SMEs also by numbers dominate the world business stage, although their contribution does vary among the countries. SMEs in Albania represents about 98% of the total enterprises with a contribution to national GDP for about 70%. The structure and the performance of national economy is depended very much on the economic performance and contribution of SME, that’s why most of the governments have strategic programmes which support the SME’s development. To measure SMEs’ performance and their ability to compete on national and international markets requires a lot of information in all aspects. Through this paper the author aims to measure and analyze the economic performance of SMEs operating in Albania. To achieve this objective, official data on business statistics published by national the statistical office (INSTAT) are used for two years period 2014-2015. In addition using an international framework addressed to the objective “improve the techniques for SMEs productivity measurement”, for the first time, a set of comparative performance indicators is established and in doing so, those results can be used as term of reference in future research activities in SMEs sector. From the results it came out that although the positive growth rate of GDP during the last years , the performance indicators of SMEs show a slightly negative trend, indicating indirectly the need for support, in order to empower their contribution in national economy.

scholarly journals Reinforcement learning versus swarm intelligence for autonomous multi-HAPS coordination

2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Ogbonnaya Anicho ◽  
Philip B. Charlesworth ◽  
Gurvinder S. Baicher ◽  
Atulya K. Nagar
Keyword(s):  
Reinforcement Learning ◽  
State Space ◽  
Swarm Intelligence ◽  
Performance Indicators ◽  
Convergence Rates ◽  
Tuning Parameters ◽  
Continuous State Space ◽  
Continuous State ◽  
User Coverage ◽  
Better Than

AbstractThis work analyses the performance of Reinforcement Learning (RL) versus Swarm Intelligence (SI) for coordinating multiple unmanned High Altitude Platform Stations (HAPS) for communications area coverage. It builds upon previous work which looked at various elements of both algorithms. The main aim of this paper is to address the continuous state-space challenge within this work by using partitioning to manage the high dimensionality problem. This enabled comparing the performance of the classical cases of both RL and SI establishing a baseline for future comparisons of improved versions. From previous work, SI was observed to perform better across various key performance indicators. However, after tuning parameters and empirically choosing suitable partitioning ratio for the RL state space, it was observed that the SI algorithm still maintained superior coordination capability by achieving higher mean overall user coverage (about 20% better than the RL algorithm), in addition to faster convergence rates. Though the RL technique showed better average peak user coverage, the unpredictable coverage dip was a key weakness, making SI a more suitable algorithm within the context of this work.

scholarly journals Is the German Mittelstand more resistant to crises?

2021 ◽  
Author(s):  
Michael Berlemann ◽  
Vera Jahn ◽  
Robert Lehmann
Keyword(s):  
Great Recession ◽  
Supporting Evidence ◽  
Comparative Performance ◽  
The Great Recession ◽  
Vital Interest ◽  
The World ◽  
International Factor Mobility ◽  
Business Survey ◽  
Globalized World ◽  
Better Than

AbstractIn a globalized world with high international factor mobility, crises often spread quickly over large parts of the world. Politicians carry a vital interest in keeping crises as small and short as possible. Against this background we study whether the type of company of owner-managed SMEs, in Germany well-known as Mittelstand firms, helps increasing an economy’s crisis resistance. We study this issue at the example of the Great Recession of the years 2008/2009. Using micro panel data from the ifo Business Survey, we study the comparative performance of Mittelstand enterprises and find supporting evidence for the hypothesis that Mittelstand firms performed more stable throughout the Great Recession than non-Mittelstand firms. We also show that owner-managed SMEs performed significantly better than SMEs and owner-managed large enterprises. Thus, it is rather the combination of firm size and owner-management that leads to more crisis resistance.

scholarly journals Characterization and Simulation of a Low-Pressure Rotator Spray Plate Sprinkler Used in Center Pivot Irrigation Systems

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1684 ◽  
Author(s):  
Cruz Octavio Robles Rovelo ◽  
Nery Zapata Ruiz ◽  
Javier Burguete Tolosa ◽  
Jesús Ramiro Félix Félix ◽  
Borja Latorre
Keyword(s):  
Drag Coefficient ◽  
Distribution Pattern ◽  
Size Distribution ◽  
Water Distribution ◽  
Drop Size ◽  
Low Pressure ◽  
Drop Size Distribution ◽  
Energy Losses ◽  
Conventional Model ◽  
The Impact

Spray sprinklers enable to operate at low pressures (<103 kPa) in self-propelled irrigation machines. A number of experiments were performed to characterize the water distribution pattern of an isolated rotator spray plate sprinkler operating at very low pressure under different experimental conditions. The experiments were performed under two pressures (69 kPa and 103 kPa) and in calm and windy conditions. The energy losses due to the impact of the out-going jet with the sprinkler plate were measured using an optical technique. The adequacy to reproduce the measured water distribution pattern under calm conditions of two drop size distribution models was evaluated. A ballistic model was used to simulate the water distribution pattern under wind conditions evaluating three different drag models: (1) considering solid spherical drops; (2) a conventional model based on wind velocity and direction distortion pattern, and (3) a new drag coefficient model independent of wind speed. The energy losses measured with the optical method range from 20% to 60% from higher to lower nozzle sizes, respectively, for both evaluated working pressures analyzing over 16,500 droplets. For the drop size distribution selected, Weibull accurately reproduced the water application with a maximum root mean square error (RMSE) of 19%. Up to 28% of the RMSE could be decreased using the wind-independent drag coefficient model with respect to the conventional model; the difference with respect to the spherical model was 4%.

The Financial Consequences of Rating International Institutions: Competition, Collaboration, and the Politics of Assessment

2020 ◽  
Author(s):  
Ranjit Lall
Keyword(s):  
Performance Indicators ◽  
International Institutions ◽  
Resource Competition ◽  
Comparative Performance ◽  
The Past ◽  
Key Informant ◽  
Financial Consequences ◽  
Donor States ◽  
Funding Cuts ◽  
The Relationship

Abstract The past 15 years have witnessed a striking trend in global governance: the creation of comparative indicators of the performance of international institutions by donor states seeking to allocate their resources more efficiently. Interestingly, however, not all highly rated institutions have been “rewarded” with increased contributions, while not all poorly rated institutions have been “punished” with funding cuts or freezes. I argue that the financial impact of performance indicators is contingent upon the relationship between institutions and other actors within their environment, with stronger effects occurring when institutions (1) are subject to a higher degree of resource competition and (2) possess deeper and more extensive operational alliances with actors above and below the state. I test the argument using a mixed-methods strategy that draws on a variety of original sources, including key informant interviews and a new dataset covering fifty-three institutions over the period 2000–2016. The findings enhance our understanding of when and why comparative performance indicators influence resource flows to assessed entities.

scholarly journals Low-pressure sprinkler irrigation in maize: Differences in water distribution above and below the crop canopy

2018 ◽  
Vol 203 ◽  
pp. 353-365 ◽  
Author(s):  
N. Zapata ◽  
O. Robles ◽  
E. Playán ◽  
P. Paniagua ◽  
C. Romano ◽  
...  
Keyword(s):  
Water Distribution ◽  
Sprinkler Irrigation ◽  
Low Pressure ◽  
Crop Canopy

RANKING DEVELOPER CANDIDATES BY SOCIAL LINKS

2014 ◽  
Vol 17 (07n08) ◽  
pp. 1550005 ◽  
Author(s):  
QI XUAN ◽  
CHENBO FU ◽  
LI YU
Keyword(s):  
Social Networks ◽  
Open Source ◽  
Open Source Software ◽  
Performance Indicators ◽  
Temporal Networks ◽  
Successful Operation ◽  
Weighted Networks ◽  
Ranking Algorithms ◽  
The Future ◽  
Better Than

In open source software (OSS) projects, participants initially communicate with others and then may become developers if they are deemed worthy by the community. Recent studies indicate that the abundance of established social links of a participant is the strongest predictor to his/her promotion. Having reliable rankings of the candidates is key to recruiting and maintaining a successful operation of an OSS project. This paper adopts degree-based, PageRank, and Hits ranking algorithms to rank developer candidates in OSS projects based on their social links. We construct several types of social networks based on the communications between the participants in Apache OSS projects, then train and test the ranking algorithms in these networks. We find that, for all the ranking algorithms under study, the rankings of emergent developers in temporal networks are higher than those in cumulative ones, indicating that the more recent communications of a developer in a project are more important to predict his/her first commit in the project. By comparison, the simple degree-based and the PageRank ranking algorithms in temporal undirected weighted networks behave better than the others in identifying emergent developers based on four performance indicators, and are thus recommended to be applied in the future.

Sign in / Sign up

Export Citation Format

Share Document