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The Vibration Characteristics of Diesel Engine Cylinder Piston Rings Under Different Wear
Yongchao Cheng,
Yaofei Li,
Miao Zhang,
Haihua Deng,
Shuai Wang
Issue:
Volume 7, Issue 4, December 2021
Pages:
92-96
Received:
16 July 2021
Accepted:
25 October 2021
Published:
5 November 2021
Abstract: In this paper, Through the experimental research on the wear of cylinder liner and piston ring of diesel engine under different forms, The purpose is to study the vibration law of piston ring of cylinder liner of diesel engine under different wear conditions, and obtain the vibration law through vibration signal analysis, which provides theoretical support for the design of diesel engine. The relevant laws are obtained, which provides good technical support for the follow-up design and research. to explore the use of vibration signals to monitor the cylinder piston ring wear state of the feasibility of starting, summed up the vibration signal of diesel engine piston ring and cylinder liner wear contact the specific state, According to the wear state of multiple sets of cylinder liner piston rings and the change trend of each characteristic parameters of vibration signal: As the wear of the piston ring increases, the vibration signal increases and the vibration characteristic parameters increases; The variation trend of each vibration characteristic quantity with the cylinder liner piston ring is basically the same, and it increases with the increase of wear quantity; When the amount of cylinder liner piston ring is large, the gap between them is also large. The increase of clearance causes the change of characteristic parameters greatly, otherwise it is smaller. Therefore, the larger the gap, the more reliable the diagnosis will be the vibration signal analysis cylinder piston ring wear state of the specific program for diesel engine maintenance and provides the basis for maintenance.
Abstract: In this paper, Through the experimental research on the wear of cylinder liner and piston ring of diesel engine under different forms, The purpose is to study the vibration law of piston ring of cylinder liner of diesel engine under different wear conditions, and obtain the vibration law through vibration signal analysis, which provides theoretical...
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Extremely Fast “Solution” to the Large-Scale and Very Large-Scale Vehicle Routing Problem
Issue:
Volume 7, Issue 4, December 2021
Pages:
97-103
Received:
21 October 2021
Accepted:
8 November 2021
Published:
17 November 2021
Abstract: A solution to the vehicle routing problem (VRP) is presented that takes only quadratic space, O(n2), and quadratic time, O(n2), if n is the number of stops on a route. The input is assumed to be a list of stops of length n in longitude, latitude format. The output is an origin-destination (OD) matrix of size O(n2), which takes O(n2) time to build. The element (i, j) in the matrix is the approximate driving distance between stop i and stop j on the route. Each approximate driving distance takes constant or O(1) time to compute. (The approximate driving distance appears in previous work by the author, published in URISA GIS-Pro ‘19 and CalGIS 2020.) This OD matrix is well-suited for solving large-scale and very large-scale VRP problems, since computing approximate driving distances is lightning fast. For instance, using real-world data, it took less than one (1) second to produce a route with 5,156 stops. The OD matrix can be used with any exact or approximation algorithm to find a route, including the nearest-neighbor approximation algorithm: Starting at an origin, the next closest stop is visited repeatedly, ending at the destination once all stops have been visited. Determining the next stop to visit takes linear or O(n) time to compute, and this is done O(n) times. This solution to the VRP is a polynomial-time, O(n2), approximation; it is not exact, but is extremely fast.
Abstract: A solution to the vehicle routing problem (VRP) is presented that takes only quadratic space, O(n2), and quadratic time, O(n2), if n is the number of stops on a route. The input is assumed to be a list of stops of length n in longitude, latitude format. The output is an origin-destination (OD) matrix of size O(n2), which takes O(n2) time to build. ...
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Impacts of Terrorism and Piracy on Maritime Activities: An Exploratory Study
Donatus Eberechukwu Onwuegbuchunam,
Kenneth Okechukwu Okeke,
Moses Olatude Aponjolosun,
Chinemerem Igboanusi
Issue:
Volume 7, Issue 4, December 2021
Pages:
104-109
Received:
2 September 2021
Accepted:
22 September 2021
Published:
25 November 2021
Abstract: The international community is paying more and more attention to the activities of terrorists and pirates, which have greatly hindered the flow of international seaborne trade and other maritime activities. Many national governments have implemented certain security policies to address the twin problem of terrorism and piracy with minimal results achieved. The researchers propose that policy effective response models for addressing these security problems must be based on quantitative analysis of impacts of terrorism and piracy on the affected maritime domain. This paper assessed impacts of terrorism and piracy on maritime related economic activities in Niger Delta region of Nigeria. The data for this study comprised volume of crude oil production, quantity of crude oil in tanker vessels lost to terrorism acts and the quantity of fish catch/production over a period of fifteen years (2000-2015). We employed Linear Regression Analysis model to determine significant correlations between pairs of economic variables in the study. Findings showed that significant inverse relationship exists between the selected maritime related economic activities and acts of maritime terrorism and piracy. Policy implications of the results were discussed.
Abstract: The international community is paying more and more attention to the activities of terrorists and pirates, which have greatly hindered the flow of international seaborne trade and other maritime activities. Many national governments have implemented certain security policies to address the twin problem of terrorism and piracy with minimal results a...
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Application of Artificial Intelligence in Ship Integrated Navigation System
Issue:
Volume 7, Issue 4, December 2021
Pages:
110-117
Received:
11 November 2021
Accepted:
22 November 2021
Published:
11 December 2021
Abstract: With the continuous development of navigation, modern ships put forward higher requirements for the accuracy, reliability and intelligence of navigation system. Aiming at the problems existing in the existing ship navigation system, such as insufficient navigation information fusion accuracy, increasingly important navigation safety guarantee and increasing system failure frequency, based on ship integrated navigation system, the navigation system based on artificial intelligence technology is studied. The application of artificial intelligence technology in Kalman filter fusion, navigation collision avoidance decision and intelligent fault diagnosis is deeply studied, and the navigation intelligent collision avoidance expert system is established to judge whether there will be dangerous situations such as collision, and then the decision-making gives the avoidance action plan; The navigation fault diagnosis expert system based on neural network is established to automatically diagnose the random and sudden faults such as ship equipment dysfunction or data abnormality, and the diagnosis results are given and explained. The results show that artificial intelligence technology can effectively improve the accuracy and reliability of data fusion, automatically generate collision avoidance strategies and optimization schemes when ships meet dangerous targets, and realize intelligent fault diagnosis of navigation system. It has important theoretical guiding significance for the development of new ship integrated navigation system towards higher precision, higher reliability and intelligence.
Abstract: With the continuous development of navigation, modern ships put forward higher requirements for the accuracy, reliability and intelligence of navigation system. Aiming at the problems existing in the existing ship navigation system, such as insufficient navigation information fusion accuracy, increasingly important navigation safety guarantee and i...
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