A simplified approach to the basic principle of security measures onboard ships

There are many reasons whymerchant ships make desirable targetsfor pirates and terrorists as well as aconvenient means of transport for thestowaway. Criminal activity in the form ofsuch threats is quickly becoming one ofthe greatest threats to ships and

Autonomous Evolutionary Information Systems

Traditional information systems are passive, i.e., data or knowledge is created, retrieved, modified, updated, and deleted only in response to operations issued by users or application programs, and the systems only can execute queries or transactions explicitly submitted by users or application programs but have no ability to do something actively by themselves. Unlike a traditional information system serving just as a storehouse of data or knowledge and working passively according to queries or transactions explicitly issued by users and application programs, an autonomous evolutionary information system serves as an autonomous and evolutionary partner of its users that discovers new knowledge from its database or knowledge base autonomously, cooperates with its users in solving problems actively by providing the users with advices, and has a certain mechanism to improve its own state of “knowing” and ability of “working”. This paper seminally defines what is an autonomous evolutionary information system, explain why autonomous evolutionary information systems are needed, and presents some new issues, fundamental considerations, and research directions in design and development of autonomous evolutionary information systems.

Friction coefficient and error test via micro-rotation mechanics model

An air pressure-loading mode incorporated into the friction apparatus is firstly applied to coatings tribology involving large load, automation, stepless and continuous loading processes. A novel measurement principle is proposed and a micro-rotation mechanics model was developed for high precision measurement of friction coefficient. By properly designing and locating two sensors real-time monitoring the normal and friction forces, the troublesome influences in friction measurement is considerably relieved which come from surface characteristics of coatings of the samples in traditional friction test processes. By calculation and analysis, the max rotation angle 0max = 0.0018°is gained, which indicates that the measurement error of the apparatus is greatly reduced. The whole system error is about 1.15% given by finite element method and indication error of the least square fitting of measurements.

Review of research progress on soil moisture sensor technology

Soil moisture is directly related to the amount of irrigation in agriculture and influences the yield of crops.Accordingly,a soil moisture sensor is an important tool for measuring soil moisture content.In this study,the previous research conducted in recent 2-3 decades on soil moisture sensors was reviewed and the principles of commonly used soil moisture sensor and their various applications were summarized.Furthermore,the advantages,disadvantages,and influencing factors of various measurement methods employed were compared and analyzed.The improvements were presented by several scholars have established the major applications and performance levels of soil moisture sensors,thereby setting the course for future development.These studies indicated that soil moisture sensors in the future should be developed to achieve high-precision,low-cost,non-destructive,automated,and highly integrated systems.Also,it was indicated that future studies should involve the development of specialized sensors for different applications and scenarios.This review research aimed to provide a certain reference for application departments and scientific researchers in the process of selecting soil moisture sensor products and measuring soil moisture.