scholarly journals Numerical Analysis of Stem Wave Control Effect of a Curved Slit Caisson Breakwater

2021 ◽  
Vol 8 (3) ◽  
pp. 181-192
Author(s):  
Yong Jun Cho
Keyword(s):  
Wave Interaction ◽  
Structural Type ◽  
Effective Control ◽  
Control Effect ◽  
Design Factor ◽  
The Past ◽  
Resonance Wave ◽  
Caisson Breakwater ◽  
Rough Sea ◽  
Wave Control

Curved slit caisson has been the preferred structural type of breakwater in South Korea, and effective control of stem waves is a crucial design factor significantly affecting the performance of a curved slit caisson breakwater. Most of the past studies on stem waves heavily relied on wave drivers like the cubic Schrödinger Eq. due to the intrinsic difficulties in analyzing stem waves. However, considering the perturbation method evoked in the derivation of cubic Schrödinger Eq., the wave driver mentioned above could give erroneous results in the rough sea due to the higher-order waves that appeared in the wave field by resonance wave-wave interaction. In this rationale, in this study, the numerical simulation was implemented to verify the stem wave control effect of curved slit caisson using the ihFoam, toolbox having its roots on OpenFoam. It was shown that curved slit caisson breakwater effectively alleviates the scope and height of stem waves.

Implementasi Algoritma Hamming Distance dan Brute Force dalam Mendeteksi Kemiripan Source Code Bahasa Pemrograman C

2017 ◽  
Vol 8 (2) ◽  
Author(s):  
Andreas Budiman ◽  
Dennis Gunawan ◽  
Seng Hansun
Keyword(s):  
College Presidents ◽  
Hamming Distance ◽  
Source Code ◽  
Structural Type ◽  
Brute Force ◽  
Important Thing ◽  
The Past ◽  
Index Terms ◽  
Better Than

Plagiarism is a behavior that causes violence of copyrights. Survey shows 55% of college presidents say that plagiarism in students’ papers has increased over the past 10 years. Therefore, an application for detecting plagiarism is needed, especially for teachers. This plagiarism checker application is made by using Visual C# 2010. The plagiarism checker uses hamming distance algorithm for matching line code of the source code. This algorithm works by matching the same length string of the code programs. Thus, it needs brute will be matched with hamming distance. Another important thing for detecting plagiarism is the preprocessing, which is used to help the algorithm for detecting plagiarized source code. This paper shows that the application works good in detecting plagiarism, the hamming distance algorithm and brute force algorithm works better than levenstein distance algorithm for detecting structural type of plagiarism and this thesis also shows that the preprocessing could help the application to increase its percentage and its accuracy. Index Terms—Brute Force, Hamming Distance, Plagiarisme, Preprocessing.

scholarly journals Controlling mine pressure by subjecting high-level hard rock strata to ground fracturing

2021 ◽  
Author(s):  
Rui Gao ◽  
Tiejun Kuang ◽  
Yanqun Zhang ◽  
Wenyang Zhang ◽  
Chunyang Quan
Keyword(s):  
Energy Release ◽  
Physical Simulation ◽  
Hard Rock ◽  
Structural Characteristics ◽  
Effective Control ◽  
Mine Pressure ◽  
Control Effect ◽  
Propagation Length ◽  
Ground Pressure ◽  
High Level

AbstractWhen mining extra-thick coal seams, the main cause of strong ground pressure are the high-level thick and hard strata, but as yet there is no active and effective control technology. This paper proposes the method of subjecting hard roofs to ground fracturing, and physical simulation is used to study the control effect of ground fracturing on the strata structure and energy release. The results show that ground fracturing changes the structural characteristics of the strata and reduces the energy release intensity and the spatial extent of overburden movement, thereby exerting significant control on the ground pressure. The Datong mining area in China is selected as the engineering background. An engineering test was conducted on site by ground horizontal well fracturing, and a 20-m-thick hard rock layer located 110 m vertically above the coal seam was targeted as the fracturing layer. On-site microseismic monitoring shows that the crack propagation length is up to 216 m and the height is up to 50 m. On-site mine pressure monitoring shows that (1) the roadway deformation is reduced to 100 mm, (2) the periodic weighting characteristics of the hydraulic supports are not obvious, and (3) the ground pressure in the working face is controlled significantly, thereby showing that the ground fracturing is successful. Ground fracturing changed the breaking characteristics of the high-level hard strata, thereby helping to ameliorate the stress concentration in the stope and providing an effective control approach for hard rock.

scholarly journals Wave interaction with caisson breakwater placed on porous bottom foundation

2020 ◽  
Author(s):  
Santanu Koley ◽  
K. Panduranga ◽  
Dipak K. Satpathi
Keyword(s):  
Wave Interaction ◽  
Caisson Breakwater

scholarly journals Long-term O<sub>3</sub>–precursor relationships in Hong Kong: field observation and model simulation

2017 ◽  
Vol 17 (18) ◽  
pp. 10919-10935 ◽  
Author(s):  
Yu Wang ◽  
Hao Wang ◽  
Hai Guo ◽  
Xiaopu Lyu ◽  
Hairong Cheng ◽  
...  
Keyword(s):  
Hong Kong ◽  
Model Simulation ◽  
Ground Level ◽  
Effective Control ◽  
Photochemical Pollution ◽  
Mixing Ratios ◽  
The Past ◽  
Total Volatile Organic Compounds

Abstract. Over the past 10 years (2005–2014), ground-level O3 in Hong Kong has consistently increased in all seasons except winter, despite the yearly reduction of its precursors, i.e. nitrogen oxides (NOx =  NO + NO2), total volatile organic compounds (TVOCs), and carbon monoxide (CO). To explain the contradictory phenomena, an observation-based box model (OBM) coupled with CB05 mechanism was applied in order to understand the influence of both locally produced O3 and regional transport. The simulation of locally produced O3 showed an increasing trend in spring, a decreasing trend in autumn, and no changes in summer and winter. The O3 increase in spring was caused by the net effect of more rapid decrease in NO titration and unchanged TVOC reactivity despite decreased TVOC mixing ratios, while the decreased local O3 formation in autumn was mainly due to the reduction of aromatic VOC mixing ratios and the TVOC reactivity and much slower decrease in NO titration. However, the decreased in situ O3 formation in autumn was overridden by the regional contribution, resulting in elevated O3 observations. Furthermore, the OBM-derived relative incremental reactivity indicated that the O3 formation was VOC-limited in all seasons, and that the long-term O3 formation was more sensitive to VOCs and less to NOx and CO in the past 10 years. In addition, the OBM results found that the contributions of aromatics to O3 formation decreased in all seasons of these years, particularly in autumn, probably due to the effective control of solvent-related sources. In contrast, the contributions of alkenes increased, suggesting a continuing need to reduce traffic emissions. The findings provide updated information on photochemical pollution and its impact in Hong Kong.

Nanosecond dielectric barrier discharge–based dynamic stall control on an SC-1095 airfoil

2020 ◽  
pp. 095965182094582
Author(s):  
He-sen Yang ◽  
Hua Liang ◽  
Guang-yin Zhao
Keyword(s):  
Dielectric Barrier Discharge ◽  
Barrier Discharge ◽  
Actuation Voltage ◽  
Dynamic Stall ◽  
Effective Control ◽  
Control Effect ◽  
Actuation Frequency ◽  
Dielectric Barrier ◽  
Reduced Frequency ◽  
Dependent Flow

Dynamic stall is a time-dependent flow separation and stall phenomenon that is present in many applications, including violently maneuvering aircraft, surging compressor, wind turbine, and, most observably, rotorcraft. Nanosecond dielectric barrier discharge plasma actuator has previously demonstrated the control ability in static stall conditions and shows promise to address dynamic stall. The present work explores the ability of nanosecond dielectric barrier discharge to control dynamic stall over an SC-1095 airfoil and summarizes the control law of actuation parameters. The actuation voltage, actuation frequency, and reduced frequencies were varied over large ranges: Vp–p = 7–13 kV, F+ = 0.5–10, and k = 0.05–0.15. Direct aerodynamic measurements were taken for each combination of actuation voltages and actuation frequencies, and fixed combination at different experimental reduced frequencies. It was observed that nanosecond dielectric barrier discharge could effectively improve the dynamic stall characteristics, and three major conclusions were drawn. First, there is a threshold for actuation voltage. Only when the actuation voltage is greater than or equal to the threshold voltage can the separation be effectively suppressed and the steep stall can be alleviated. Second, High F+ has better control performance of maintaining peak lift in the stall regime and achieves better effects in moment control and drag reduction while lift reattachment is better with low F+ on downstroke. Last, with the increase of reduced frequency, the control effect of nanosecond dielectric barrier discharge with settled actuation parameter combination becomes worse, so greater cost needs to be paid for effective control at a larger reduced frequency.

A Sort of Fuzzy Intelligence Control Strategy for Complex System

2011 ◽  
Vol 187 ◽  
pp. 169-174 ◽  
Author(s):  
Yu Cheng Liu ◽  
Yu Bin Liu
Keyword(s):  
Complex System ◽  
Control Strategy ◽  
Effective Control ◽  
Control Effect ◽  
Expert Control ◽  
Control Precision ◽  
Optimal Pid Control ◽  
Intelligence Control ◽  
Fuzzy Control Algorithm ◽  
Better Than

For complex controlled object with the large time delay link, it was difficult to get effective control effect by means of traditional fuzzy control algorithm. Aimed at enhancing the control quality in control precision and so on for complex system, the paper proposed a sort of fuzzy intelligence control strategy. It fused the expert control experience combing with human simulated intelligence control, designed the control rule, proposed the mode of running controller and explored the principle of parameter calibrating layer. The system simulation experiment explained that the control effect was much better than optimal PID control in dynamic and steady quality. The results show that the fuzzy intelligent control strategy is reasonable and feasible, high in control precision, better in dynamical and steady control effect, and it represents very strong robustness.

An inventory analysis of rural pollution loads in China

2006 ◽  
Vol 54 (11-12) ◽  
pp. 65-74 ◽  
Author(s):  
M. Chen ◽  
J. Chen ◽  
P. Du
Keyword(s):  
Agricultural Development ◽  
Municipal Wastewater ◽  
Driving Forces ◽  
Effective Control ◽  
Inventory Analysis ◽  
Agricultural Income ◽  
The Past ◽  
Increasing Demand ◽  
Pollution Loads ◽  
Rural Pollution

Rural pollution has attracted increasing attention over the past decade for its important consequences on surface and groundwater quality. This is particularly so in China due to the wide and effective control of industrial and municipal wastewater discharges over the past decade. Based on the discussion of rural activities in China, this paper develops a new method of inventory analysis through the definition of elementary unit (EU). This inventory analysis approach is then applied to estimate the total rural pollution loads of COD, TN and TP, as well as their spatial distributions in China. Further analysis is also conducted to investigate the correlations between rural pollution loads and agricultural production outputs, as well as population. It is found that China's agriculture is developing largely at the cost of environment quality, and a high population, as well as the increasing demand for agricultural products, is one of the dominant driving forces. The constructed EKC, which describes the relationship between rural pollution loads and agricultural income, also reveals that current agricultural development in China is mostly far from de-locked from the environmental problem.

scholarly journals An. gambiae s.l. exhibit high intensity pyrethroid resistance throughout Southern and Central Mali (2016-2018); PBO or next generation LLINs may provide greater control

2020 ◽  
Author(s):  
Arthur Sovi ◽  
Chitan Keita ◽  
Youssouf Sinaba ◽  
Abdourhamane Dicko ◽  
Ibrahim Traore ◽  
...  
Keyword(s):  
High Intensity ◽  
Susceptibility Testing ◽  
Pyrethroid Resistance ◽  
Fold Increase ◽  
Malaria Vectors ◽  
Effective Control ◽  
The Past ◽  
Pirimiphos Methyl ◽  
Agricultural Use ◽  
Rotation Strategy

Abstract Background: Millions of pyrethroid LLINs have been distributed in Mali during the past 20 years which, along with agricultural use, has increased the selection pressure on malaria vector populations. This study investigated pyrethroid resistance intensity and susceptible status of malaria vectors to alternative insecticides to guide choice of insecticides for LLINs and IRS for effective control of malaria vectors.Methods: For 3 years between 2016 and 2018, susceptibility testing was conducted annually in 14-16 sites covering southern and central Mali. Anopheles gambiae s.l. were collected from larval sites and adult mosquitoes exposed in WHO tube tests to diagnostic doses of bendiocarb (0.1%) and pirimiphos-methyl (0.25%). Resistance intensity tests were conducted using CDC bottle bioassays (2016-17) and WHO tube tests (2018) at 1×, 2×, 5×, and 10× the diagnostic concentration of permethrin, deltamethrin and alpha-cypermethrin. WHO tube tests were conducted with pre-exposure to the synergist PBO followed by permethrin or deltamethrin. Chlorfenapyr was tested in CDC bottle bioassays at 100µg active ingredient per bottle and clothianidin at 2% in WHO tube tests. PCR was performed to identify species within the An. gambiae complex.Results: In all sites An. gambiae s.l. showed high intensity resistance to permethrin and deltamethrin in CDC bottle bioassay tests in 2016 and 2017. In 2018, WHO intensity tests resulted in survivors at all sites for permethrin, deltamethrin and alpha-cypermethrin when tested at 10× the diagnostic dose. Across all sites mean mortality was 33.7% with permethrin (0.75%) compared with 71.8% when pre-exposed to PBO (4%), representing a 2.13 fold increase in mortality. A similar trend was recorded for deltamethrin. There was susceptibility to pirimiphos-methyl, chlorfenapyr and clothianidin in all surveyed sites, including current IRS sites in Mopti Region. An. coluzzii was the primary species in 4 of 6 regions.Conclusions: Widespread high intensity pyrethroid resistance was recorded during 2016-18 and is likely to compromise the effectiveness of pyrethroid LLINs in Mali. PBO or chlrofenapyr LLINs should provide improved control of An. gambiae s.l. Clothianidin and pirimiphos-methyl insecticides are currently being used for IRS as part of a rotation strategy based on susceptibility being confirmed in this study.

scholarly journals Combined use of a microbial restoration substrate and avirulent Ralstonia solanacearum for the control of tomato bacterial wilt

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Xuefang Zheng ◽  
Yujing Zhu ◽  
Jieping Wang ◽  
Ziran Wang ◽  
Bo Liu
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Combined Treatment ◽  
Control Measures ◽  
Effective Control ◽  
Control Effect ◽  
Tomato Production ◽  
Combined Use ◽  
Promote Plant Growth ◽  
Tomato Bacterial Wilt

AbstractTomato bacterial wilt (BW) caused by Ralstonia solanacearum seriously restricts tomato production and no effective control measures are available. A microbial restoration substrate (MRS) had been proved to be effective control of tomato BW in a greenhouse cultivation. In this study, MRS was combined with an avirulent Ralstonia solanacearum (aRS) strain to control the disease under an open field condition. In the two consecutive year (2017 and 2018) trials, the combined use of aRS and MRS resulted in better disease control compared with either aRS or MRS alone. Moreover, the combined treatment was more effective than expected and suggesting a synergistic control effect. Compared with control (CK, non-aRS or MRS), the application of aRS and MRS treatments alone or in combination could all promote plant growth, increase root activity and yield (e.g. the yield for the treatment of aRS + MRS increased by 463.64% in 2017). Soil nutrients, including soil organic carbon, total nitrogen, total phosphorus and total potassium contents were also significantly increased by the application of aRS and MRS treatments alone or in combination (P < 0.05). The application of MRS or in combination with aRS changed the soil from acidic to neutral, which is one of the key factors for controlling BW. The soil enzymatic activities were notably influenced by the combined use of aRS and MRS, which increased urease (87.37% in 2017 and 60.89% in 2018), catalase (93.67% in 2017 and 279.37% in 2018) and alkaline phosphatase activities (193.77% in 2017 and 455.73% in 2018). These results suggest that the combination of MRS and aRS could effectively control tomato BW and thus represents a promising new tool to control this disease.

Chemical Weed Control in Southern Hardwood Nurseries

1984 ◽  
Vol 8 (1) ◽  
pp. 16-22
Author(s):  
David B. South
Keyword(s):  
Weed Control ◽  
Methyl Bromide ◽  
Lower Cost ◽  
Control Program ◽  
Cost Effective ◽  
Perennial Grasses ◽  
Effective Control ◽  
The Past ◽  
Weed Seeds

Abstract In the past, hardwood nurserymen often relied on fumigation with methyl bromide for weed control. Today, however, herbicides can provide cost-effective control of grasses and most annual broadleaf weeds in hardwood seedbeds. New herbicides like sethoxidim can be used to control annual and perennial grasses while germination of many broadleaf weeds can be inhibited by oryzalin, oxadiazon, or napropamide. Resistant weeds can be controlled by directed applications of glyphosate. Use of these herbicides reduces the need for fumigation, which often lowers the population of beneficial endomycorrhizal fungi. Fumigation may still be required when controlling high populations of nutsedge or when pathogens are a problem. Although use of chemicals can make control of weeds easier, the nurseryman should not rely entirely on fumigation or herbicides for weed control. If left alone to reproduce, populations of resistant weeds can quickly increase. The nurseryman should therefore adhere strictly to a comprehensive year-round weed control program that prevents introduction, reproduction, and spread of weeds. Even with these efforts, several years may be required to deplete the reservoir of weed seeds in the soil. The nurseryman who is successful will be able to produce more uniform, higher-quality seedlings at a lower cost.

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