A Comparative Research on Computation Methods for Wave Loads of Semi-Submersible Platform

2018 ◽  
Author(s):  
Zhiyong Pei ◽  
Shenyi Wu ◽  
Keqiang Chen ◽  
Xiaoming Hu ◽  
Weiguo Wu
Keyword(s):  
Wave Method ◽  
Wave Loads ◽  
Wave Load ◽  
Fundamental Research ◽  
Wave Methods ◽  
Long Term Prediction ◽  
External Loads ◽  
Selection Of

Wave load is one of the main external loads for semi-submersible platform, which is usually calculated by design wave method. In the present research, three design wave methods are investigated and compared on design wave parameters determination of semi-submersible platforms, i.e., the deterministic design wave method, stochastic design wave method and long-term prediction design wave method. Moreover, the specified calculation methods and the detailed wave load computation procedure are summarized considering the load characteristics of global hydrodynamic response. Finally, a semi-submersible platform is regarded as objective and the design wave results of three design wave methods are compared and analyzed. The fundamental research can provide reference for rational selection of wave loads calculation method.

scholarly journals Selection of Satellite Image Series for the Determination of Forest Pathology Dynamics Taking Into Account Cloud Coverage and Image Distortions Based on the Data Obtained from the Key Point Detector

2019 ◽  
Author(s):  
Евгений Трубаков ◽  
Evgeniy Trubakov ◽  
Андрей Трубаков ◽  
Andrey Trubakov ◽  
Дмитрий Коростелёв ◽  
...  
Keyword(s):  
Satellite Image ◽  
Forest Pathology ◽  
Acceptable Result ◽  
New Approach ◽  
Cloud Coverage ◽  
Point Detector ◽  
Automated Methods ◽  
Selection Of

Remote sensing of the earth and monitoring of various phenomena have been and still remain an important task for solving various problems. One of them is the forest pathology dynamics determining. Assuming its dependence on various factors forest pathology can be either short-term or long-term. Sometimes it is necessary to analyze satellite images within a period of several years in order to determine the dynamics of forest pathology. So it is connected with some special aspects and makes such analysis in manual mode impossible. At the same time automated methods face the problem of identifying a series of suitable images even though they are not covered by clouds, shadows, turbulence and other distortions. Classical methods of nebulosity determination based either on neural network or decision functions do not always give an acceptable result, because the cloud coverage by itself can be either of cirrus intortus type or insignificant within the image, but in case of cloudiness it can be the reason for wrong analysis of the area under examination. The article proposes a new approach for the analysis and selection of images based on key point detectors connected neither with cloudiness determination nor distorted area identification, but with the extraction of suitable images eliminating those that by their characteristics are unfit for forest pathology determination. Experiments have shown that the accuracy of this approach is higher than of currently used method in GIS, which is based on cloud detector.

scholarly journals Age-Related Immunoreactivity Profiles to Diverse Mycobacterial Antigens in BCG-Vaccinated Chinese Population

2021 ◽  
Vol 11 ◽  
Author(s):  
Qing-yuan Yang ◽  
Yu-tong Zhang ◽  
Jia-ni Xiao ◽  
Yu-shuo Liang ◽  
Ping Ji ◽  
...  
Keyword(s):  
Elispot Assay ◽  
Vaccine Development ◽  
Age Related ◽  
Healthy Donors ◽  
Latent Tb ◽  
Latent Tb Infection ◽  
Mycobacterial Antigens ◽  
Selection Of

Long-term immunoreactivity to mycobacterial antigens in Bovis Calmette-Guérin (BCG)-vaccinated population is not well investigated. Herein, 361 volunteer healthy donors (HDs) with neonatal BCG vaccination from Shanghai region (China) were enrolled. They were subdivided into ESAT-6/CFP10- (E6C10-) and ESAT-6/CFP10+ (E6C10+) groups based on gamma-interferon release assays (IGRAs). Three mycobacterial antigens, including Rv0934, Rv3006, and Rv3841, were subjected to the determination of immunoreactivity by ELISPOT assay. The immunoreactivities to three mycobacterial antigens were firstly compared among TB patients (N=39), E6C10+ HDs (N=78, 21.61% of HDs) and E6C10- HDs (N=283, 78.39% of HDs). It was revealed that Rv3006 was dominant upon M.tb infection, while Rv3841 was likely to be more responsive upon latent TB infection. In E6C10- population, the immunoreactivity to Rv3841 maintained along with aging, whereas those to Rv3006 and Rv0934 attenuated in E6C10- HDs older than 45 years old. Our study implies the shift of dominant antigens at different infection statuses, providing the clues for the selection of mycobacterial antigens in vaccine development and precision revaccination in the future.

Strategic analysis of the competitiveness of the enterprise

2021 ◽  
pp. 35-46
Author(s):  
Yuliia Grynchuk ◽  
Andrii Muzychenko ◽  
Kseniia Prykhod’ko
Keyword(s):  
Price Policy ◽  
Strategic Analysis ◽  
Competitive Advantages ◽  
Macroeconomic Factors ◽  
Modern Computer ◽  
Study Results ◽  
Essential Components ◽  
Selection Of

The purpose of the article is to develop a methodology of strategic analysis of enterprise competitiveness. The methodological basis of the research is the use of general scientific methods: the method of analysis and synthesis, theoretical generalization and comparison, and the means of modern computer technology for data visualization. The scientific novelty of the received results consists of developing a logical and linguistic methodology of competitiveness analysis in the long term. The article is devoted to the development of strategic analysis of the competitiveness of the enterprise. Relevance of research is caused by enterprises management in the modern markets that use innovations of products or technologies, constantly face competition, and according to its condition, should make decisions on strategic development in conformity with the country’s development market inquiries the society. Thus, the problem is not only for new companies but also for those that already function in the market and carry out planning of economic activity to become the market leader, not to lose leadership, to keep the positions. The given methodology can be used by any enterprise irrespective of the type of activity, form of ownership, or strategic goals. Conclusions. According to the study results, the methodology of strategic analysis, which is based on the study of potential internal development of the enterprise, taking into account the influence of external factors, which include macroeconomic factors of influence and market conditions. The basic approaches to the analysis of the competitiveness of the enterprise of foreign and domestic researchers are investigated in the article. The essential components of competitive advantages, which include price and non-price factors, are considered. Peculiarities of carrying out the analysis of the competitiveness of the enterprise after Porter are defined. The methodology of competitiveness analysis in the long term is developed. The main components of the strategic analysis are the estimation of activity scale in a long-term prospect, determination of strategic aims of the company, determination of aims of market coverage, selection of strategy type, selection of basic subjects of influence on competitive advantages, assessment of future relations with suppliers and buyers, assessment of cost price level, assessment of the quality of products and services and unique properties of products, formation of internal price policy. Key words: strategy, strategic analysis, competitiveness, competitive advantages.

Research of the System Based on BP Network for the Prediction of Grape Disease

2013 ◽  
Vol 462-463 ◽  
pp. 476-480
Author(s):  
Feng Bao ◽  
Juan Wang ◽  
Zhen Hui Ren
Keyword(s):  
Influencing Factors ◽  
Network Model ◽  
Network Structure ◽  
Good Effect ◽  
Bp Network ◽  
Disease Occurrence ◽  
Sample Data ◽  
Long Term Prediction ◽  
Selection Of

The text introduced a system based on BP network for the prediction of grape disease. It included the design of a network structure, the selection of parameter for network study, the processing of sample data etc. With the use of BP network model, this system can forecast the extent of grape disease, so it is applicable to the conditions which have many influencing factors, complicated relationship, difficulty of analyze quantitatively and requirement of long-term prediction. Using this system to the prediction of grape disease in Zhuo Lu area Zhang Jia Kou city, the authors obtained a good effect, which is of value to the prediction of grape disease occurrence.

Analysis of the Fatigue Damage on the Offshore Wind Turbines Exposed to Wind and Wave Loads Within the Typhoon Area

2004 ◽  
Author(s):  
Atsushi Yamashita ◽  
Kinji Sekita
Keyword(s):  
Fatigue Damage ◽  
Wind Turbines ◽  
Offshore Wind ◽  
Wave Loads ◽  
Wave Load ◽  
Offshore Wind Turbines ◽  
Simple Addition ◽  
Recorded Data ◽  
Term Data

For the design of offshore wind turbines exposed to wind and wave loads, the method of combining the wind load and the wave load is significantly important to properly calculate the maximum stresses and deflections of the towers and the foundations1). Similarly, for the analysis of the fatigue damage critical to the structural life, the influences of combined wind and wave loads have not been clearly verified. In this paper fatigue damage at the time of typhoon passing is analyzed using actually recorded data, though intrinsically long-term data more than 10years should be used to properly evaluate the fatigue damage. This paper concludes that the fatigue damage of the tower caused by the wave load is not substantial and, thus, the fatigue damage by the combined wind and wave load is only 2–3% larger than the simple addition of the independent fatigue damages by the wind and the wave loads. The fatigue damage of the tower top, which is required to reduce the diameter in order to minimize the aerodynamic confliction with blades, is larger than that of the tower bottom. The fatigue damage at the foundation by the combined wind and wave load is 25% larger than the simple addition of the wind and wave damages, as the foundation is directly exposed to the wave load. For the foundation, the proper structural section can be designed in order to improve the structural performance against fatigue.

Development of Closed Formula of Wave Load Based Upon Long-Term Prediction: Heave Acceleration and Pitch Angle

2020 ◽  
Author(s):  
Kyohei Shinomoto ◽  
Sadaoki Matsui ◽  
Kei Sugimoto ◽  
Shinsaku Ashida
Keyword(s):  
Pitch Angle ◽  
Irregular Waves ◽  
Structural Safety ◽  
Closed Formula ◽  
Wave Load ◽  
Structural Rules ◽  
Term Prediction ◽  
Long Term Prediction ◽  
Classification Society

Abstract In order to ensure the structural safety of a ship, the most severe sea states she is expected to encounter throughout her service life need to be given consideration. This is the reason why the maximum loads corresponding to such sea states are typically specified in classification society structural rules such as the Common Structural Rules (CSR) of the International Association of Classification Societies (IACS). The maximum loads used for the structural design of a ship can have a significant impact on not only her structural safety, but also her hull construction cost; therefore, it is very important that the loads be accurately estimated. The linear term of the maximum loads typically specified in some classification society rules is equivalent to a long-term predicted value with an exceedance probability of 10−8. Since the maximum loads specified in classification society rules such as the CSR were developed specifically for specific ship types, their effective application to other ship types may be somewhat limited. Aim of our larger study is to develop a closed formula of long-term prediction for maximum loads. The formula has high accuracy and can be applied to any ship size and type. This paper focused on the heave acceleration and pitch angle, which are used for the calculation of internal loads and so on. A formula which takes into account such as the standard deviation of the hull response in irregular waves and the directional distribution of irregular waves was proposed. Main ship parameters such as ship length L, breadth B, draft d, block coefficient Cb, and water line area coefficient Cw were used for formulating the long-term prediction. The accuracy and effectiveness of the proposed formula were confirmed through various numerical calculations using a linear seakeeping analysis code developed by ClassNK. The calculation covers 154 ship models (77 existing ships × 2 loading conditions per ship).

scholarly journals Determination of the importance of evaluation criteria during the process of recruitment and selection of personnel based on the application of the SWARA method

Ekonomika ◽  
2021 ◽  
Vol 67 (4) ◽  
pp. 1-9
Author(s):  
Milica Popović ◽  
Gabrijela Popović ◽  
Darjan Karabašević
Keyword(s):  
Personnel Selection ◽  
Selection Process ◽  
Evaluation Criteria ◽  
Domain Experts ◽  
Recruitment And Selection ◽  
Weighting Coefficients ◽  
Final Selection ◽  
Selection Of

Personnel selection for an organization is an extremely important process. Modern organizations strive to improve the process of recruitment and selection of personnel as much as possible, in order to provide the organization with quality personnel and thus long-term competitiveness. In addition, the evaluation criteria on which the recruitment and selection process is based is also important, as it has a large impact on the final selection of candidates. Therefore, the aim of this paper is to propose the application of multi-criteria decision-making methods for the process of determining the weighting coefficients of evaluation criteria. Accordingly, the SWARA (Step-Wise Weight Assessment Ratio Analysis) method for determining weights was applied in the paper. The SWARA method proved to be extremely reliable when it comes to defining the weights of evaluation criteria, primarily due to its simplicity and the fact that respondents and domain experts could easily express their views on the issue.

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