Optimal deadlock avoidance Petri net supervisors for automated manufacturing systems

Deadlock avoidance problems are investigated for automated manufacturing systems with flexible routings. Based on the Petri net models of the systems, this paper proposes, for the first time, the concept of perfect maximal resourcetransition circuits and their saturated states. The concept facilitates the development of system liveness characterization and deadlock avoidance Petri net supervisors. Deadlock is characterized as some perfect maximal resource-transition circuits reaching their saturated states. For a large class of manufacturing systems, which do not contain center resources, the optimal deadlock avoidance Petri net supervisors are presented. For a general manufacturing system, a method is proposed for reducing the system Petri net model so that the reduced model does not contain center resources and, hence, has optimal deadlock avoidance Petri net supervisor. The controlled reduced Petri net model can then be used as the liveness supervisor of the system.

Synthesis of Petri net supervisors enforcing general constraints

This paper deals with the synthesis of Petri net supervisor enforcing the more expressive constraints including marking terms, firing vector terms and Parikh vector terms. The method is developed to handle uncontrollable and unobservable transitions existing in the constraints. The “greater-than or equal” general constraints can also be transformed into “less-than or equal” Parikh constraints. An example is analyzed to show how the problem is solved. General constraint is first transformed into Parikh vector constraints, and Matrix-Transformation is proposed to obtain the admissible constraints without uncontrollable and unobservable transitions. Then the supervisor can be constructed based on constraints only consisting of Parikh vector terms. The method is proved to be more concise and effective than the method presented by Iordache and Moody especially when applied to large scale systems.

Public Building Supervisors＇ Assessment of Site Progress Record Keeping Practices in Abuja, Nigeria

The importance of good site progress records in quality assurance; tracking project progress; preparing, analyzing and resolving claims; and placing responsibilities in the event of dispute in building contracts is widely recognized. This study engaged Public Building Supervisors in the assessment of site progress record keeping practices in Abuja. A simple structured questionnaire （which mainly assessed the nature and importance of records kept, reasons for keeping them; level of satisfaction with the current approach, challenges and practical ways of improving the practice） was administrated to a hundred of the supervisors, out of which seventy one was properly completed and returned. The results show that all five site progress documents （minutes of progress meetings, day-work sheets, photographs, weekly site records and personal site diaries） found in literature, are in use in Abuja, and have at least a high importance rating （i.e., relative importance index, 0.6 〈 RII 〈 0.8）. Prominent among the reasons for keeping the records are： control of ongoing work （R11 = 0.83） data for estimating future works and terms of contract requirement （each with RII = 0.823）. Though the present record keeping practices were largely assessed satisfactory, 95% of the Supervisors still yearned for improvement. The challenges to the current practice are consistent with those identified in literature and are： continuity consistency, legibility and accountability; in descending order of frequency of occurrence. Computerization, regular inspection of progress documents by assigned supervisors and in-house training of site staff are recommended for improving the record keeping practices.

Non-Deterministic Liveness-Enforcing Supervisor Tolerant to Sensor-Reading Modification Attacks

In this paper, we study the supervisory control problem of discrete event systems assuming that cyber-attacks might occur. In particular, we focus on the problem of liveness enforcement and consider a sensor-reading modification attack(SM-attack) that may disguise the occurrence of an event as that of another event by intruding sensor communication channels. To solve the problem, we introduce non-deterministic supervisors in the paper, which associate to every observed sequence a set of possible control actions offline and choose a control action from the set randomly online to control the system. Specifically, given a bounded Petri net(PN) as the reference formalism and an SMattack, an algorithm that synthesizes a liveness-enforcing nondeterministic supervisor tolerant to the SM-attack is proposed for the first time.

Research on the Influence of Early Experience on the Growth Rate of Science and Engineering Graduate Supervisors

This research is based on three northeastern double first-class polytechnic universities.A total of 1628 science and engineering graduate supervisors?resumes were referred to from an official website by the random sampling method,of which only 500 supervisors were included in consideration of complete information,key events,and time in terms of the educational background(undergraduate school,graduate school,doctoral school,number of masters,number for Dr.),early work background(number of postdocs,number of overseas visits,numbers of research work),and the growth rate(period from graduation to associate professor title).The higher education background and early work background were defined as early experience,and the database of these 500 science and engineering graduate supervisors with complete resume information from three double first-class universities in northeastern China was established.In this study,the growth rate of the growth period was divided into two at the critical period:the growth rate of the graduate supervisor to associate professors.Through stepwise multiple regression analysis,it was found that higher education background(undergraduate schools,graduate schools,doctoral schools,as well as the number of master's and doctorate degrees)as well as early work background(number of postdoctoral work,research work,and overseas visits)have a significant impact on the growth rate of graduate supervisors to associate professors.

The Impact of Supervisory Career Support on Employees’Well-Being:A Dual Path Model of Opportunity and Ability

Background:In the pursuit of fostering employees’well-being,leaders are recognized as playing a vital role.However,so far,most of the existing research has focused on leadership behavior and the superficial interaction between leaders and members but has unexpectedly ignored the specific supporting role of supervisors in the career development of employees,that is,supervisory career support.Additionally,the internal mechanism of how career support from supervisors is related to and promotes employees’wellbeing is still unclear.Based on social cognitive career theory(SCCT),this study aimed to explore whether,how,and when supervisory career support affects employee well-being by introducing the two paths of‘career prospect’and‘career confidence.’Methods:During July 2023,this study employed a cross-sectional design.We gathered participants from corporate situated in Southern China.Results:Results based on a large sample of 14,533 employees showed that supervisory career support was positively related to employees’well-being through the dual path of career prospects(opportunity)and career confidence(ability).Employees high in proactive personality experienced the above positive effects most.Conclusion:This study provides meaningful implications for managers to implement personalized support strategies to improve employees’well-being.

Dilemmas and Optimization of Third-Party Assessment System in Chinese Fair Competition Review

The current predominant self-review mechanism by policy-making bodies suffers from deficiencies such as insufficient motivations, limited review capabilities, and weak external supervision. Third-party assessment, characterized by independence and specialization, is designed to mitigate these shortcomings. However, the implementation of third-party assessment faces challenges too. This paper intends to improve the third-party assessment system and to realize the legislative purpose of the system. Based on social research, discussions and exchanges with relevant parties, and the existing research results, this paper analyzes the challenges and possible optimization measures for the third-party assessment. The challenges include repulsion from policy-making bodies, insufficient independence of assessment bodies, disparity of assessment quality, and limited application of assessment outcomes. Possible optimization measures include promoting fair competition culture, increasing the acceptance of third-party assessment from policy-making bodies, enhancing the quality of third-party assessment, clarifying the relationship between policy-making bodies and assessment bodies, ensuring the independence of third-party assessments, and promoting the application of assessment results.

Selection of Third-party Logistics Provider for Agricultural Products Based on System Comprehensive Evaluation

Through the analysis on the meanings and features as well as the ad- vantages of the third-party logistics for agricultural products, the quantization index system for the selection of third-party logistics providers for agricultural products was constructed based on the system comprehensive evaluation theory. Analytic hierar- chy process （AHP） was used to determine the weight of the index system of each level, and AHP and fuzzy comprehensive evaluation method were used to determine the selection steps for the third-party logistics providers for agricultural products. The method was proved to be scientific and reasonable through calculation examples.

The third-party regulation on food safety in China:A review

Stakeholders in the field of food safety management in China can be classified into three categories, government, food producers （farmers and enterprises）, and the third-party regulatory bodies. The third-party regulation has experienced rapid development in past twenty years, and recently received considerable attention from consumers and the central government. This paper provides a review about the development, problems and future trend of the third-party regulation on food safety in China. To be specific, five forms of the third-party regulation are assessed, including media exposure, the third-party certification, regulation by consumer associations, social movements promoted by non-governmental organiza- tions （NGOs）, and regulation by industry associations. The study concludes that media and consumer associations are the major players in the third-party regulation and are highly repudiated among customers. The food certification industry has developed rapidly, but is now facing crises of confidence among consumers because of its lack of self-regulation. NGOs and industry associations still remain in the early development stages of food safety management, and therefore, are of little importance in current regulatory bodies.

Deadlock-free Supervisor Design for Robotic Manufacturing Cells With Uncontrollable and Unobservable Events

In this paper,a deadlock prevention policy for robotic manufacturing cells with uncontrollable and unobservable events is proposed based on a Petri net formalism.First,a Petri net for the deadlock control of such systems is defined.Its admissible markings and first-met inadmissible markings(FIMs)are introduced.Next,place invariants are designed via an integer linear program(ILP)to survive all admissible markings and prohibit all FIMs,keeping the underlying system from reaching deadlocks,livelocks,bad markings,and the markings that may evolve into them by firing uncontrollable transitions.ILP also ensures that the obtained deadlock-free supervisor does not observe any unobservable transition.In addition,the supervisor is guaranteed to be admissible and structurally minimal in terms of both control places and added arcs.The condition under which the supervisor is maximally permissive in behavior is given.Finally,experimental results with the proposed method and existing ones are given to show its effectiveness.

The Status Quo of Chinese Agro-products Logistics and the Establishment of the Third-Party Logistics Mode

The status quo of Chinese agro-products logistics is analyzed from the following five aspects:the circulation mode,exchange mode,storage and transportation situation,food security.The following problems in Chinese agro-products logistics are pointed out,including excessive circulation sections,bad time efficiency,single payment,slow circulation,backward information processing,obvious bullwhip effect,low logistics efficiency,low logistics technology,inadequate professional equipments,low standardization degree,organized operation mode and low degree of scale.The third-party logistics mode of agro-products is analyzed and the advantages of the mode are analyzed as well.Firstly,establishing information network through integrating circulation section to accelerate the circulation of agro-products;secondly,making the operation norms by providing professional equipments to secure the quality of agricultural products;thirdly,improving the core competitiveness of the whole logistics chain by intensifying specialized work division in each section of the supply chain;fourthly,through forming scale economy to reduce logistics costs and increase the diversity of products;fifthly,through signing contracts to clarify duties and responsibilities and materialize the profit integration of the supply chain.The measures for establishing the third-party logistics of agro-products are put forward,including establish the awareness and concept of socialized logistics services;intensify the support on the third-party logistics enterprises of agro-products;lay stress on the cultivation of logistics talents of agro-products;and vigorously apply the modern marketing means.

China-Japan Cooperation in Third-Party Markets: Japan's Strategic Thinking and Its Obstacles

Japan’s decision to cooperate with China in third-party markets along the Belt and Road routes reflects the Abe government’s strategic reorientation and comprehensive reassessment of domestic and external situation. Such cooperation is a brand-new path for the two sides to achieve win-win outcomes as well as steady and sustainable bilateral relations.

Analysis of Problems and Policy Recommendations for the Third-party Evaluation in the Present Poverty Alleviation

The introduction of third-party evaluation system and the implementation of third-party evaluation system in poverty alleviation is a major innovation in the targeted poverty alleviation work in China.In order to improve the third-party evaluation mechanism,further improve the efficiency of third-party evaluation,and enhance the effectiveness of targeted poverty alleviation,this paper analyzes and summarizes the main problems existing in the current third-party evaluation practice.In view of the related problems,this paper puts forward the corresponding policy recommendations,which are believed to play a positive role in further promoting the development and improvement of the third-party evaluation of getting rid of poverty.

Operational risk assessment of third-party payment platforms:a case study of China

Operational risk events have severely impacted the development of third-party payment(TPP)platforms,and have even led to a discussion on the operational risk capital charge settlement by relevant international regulators.However,prior studies have mostly focused on qualitative mechanism analysis,and have rarely examined quantitative risk assessment based on actual operational risk events.Therefore,this study attempts to assess the operational risk on TPP platforms in China by constructing a systematic framework incorporating database construction and risk modeling.First,the operational risk database that covers 202 events between Q1,2014,and Q2,2020 is constructed.Then,specific causes are clarified,and the characteristics are analyzed from both the trend and loss severity perspectives.Finally,the piecewise-defined severity distribution based-Loss Distribution Approach(PSD-LDA)with double truncation is utilized to assess the operational risk.Two main conclusions are drawn from the empirical analysis.First,legal risk and external fraud risk are the two main causes of operational risk.Second,the yearly Value at Risk and Expected Shortfall are 724.46 million yuan and 1081.98 million yuan under the 99.9%significance level,respectively.Our results are beneficial for both TPP platform operators and regulators in managing and controlling operational risk.

Reliable Train Network with Active Supervisor

In this paper, a new reliable hierarchical model is suggested for a two-wagon train Networked Control System. Each wagon has a Controller that carries the control load and an Entertainment server that handles the entertainment. A supervisory controller runs on top of the two controllers and the two entertainment servers. Contrary to a similar model in the literature, the Supervisory node replaces a Controller as soon as it fails (Active Supervisor). All system states are analyzed and simulated using OPNET. It is shown that, for all states, this architecture has zero control packets dropped and the end-to-end delay is below the maximum target delay. A comparison between this Active model and the other model in the literature is presented. It is found that the entertainment in this new architecture is kept available for the passengers in more of the system states when compared to the architecture previously presented in the literature.

The Design of Supervisory Institutions in the Ming Dynasty and Its Enlightenment to Modern Society

The supervisory system and the examination system are two indigenous political systems of China,and the former has a longer history than the latter when it comes to the origin.Having inherited the essence of the supervisory system since the Qin Dynasty,the supervisory rules in the Ming Dynasty opened a new chapter of legal thoughts of monitoring.This paper started with the design of the supervisory institutions in the Ming Dynasty recorded in the historical materials such as the Memoir of Ming Dynasty and The Interpretive Supplements to"The Great Learning",to get a glimpse of the main content of the legal thoughts of supervisory at that time,and tried to"take history as a mirror"to provide insights and lessons of the legal thoughts of supervisory in the Ming Dynasty for the later generations.

Perfection solutions of supervisory audit in Chinese listed companies

Operational mechanism of supervisory audit in Chinese listed companies is not ideal, the supervisory effect of the listed company rely on features of supervisors＇ board and member of the supervisors＇ board. Based on the comparison of supervisory audit in Britain, Germany, France and Japan, and the empirical research on 100 listed companies in a share market, the paper analyses supervisory audit in Chinese listed companies, and proposes some perfection solutions to strengthen supervisory audit.

Exploring Third-party Markets through BRI

IN June 2015,China and France released a joint statement to explore third-party markets.The statement,for the first time,put forward the concept of“cooperation in third-party markets,”and defined the key areas to be tapped into as well as the basic principles to be followed.

Hybrid Intelligent Approach for the Selection of Third-Party Reverse Logistics Provider under Uncertainty

A hybrid intelligent approach is proposed to help the decision maker to select the appropriate third-party reverse logistics provider. The following process is included: firstly,the evaluation team is established to determine the selection criteria and evaluate them by triangular fuzzy numbers; secondly,calculate the weight of criteria by the proposed hybrid algorithm integrating particle swarm optimization( PSO) and simulated annealing( SA); then, the performance evaluation for each supplier is predicted by the proposed self-feedback neural network( SFBNN) based on the historical data. A numerical example is also presented to interpret the methodology above.

Work Effectiveness,Problems and Countermeasures of Third-Party Assessment Teams from Colleges and Universities for Targeted Poverty Alleviation

Conducting a third-party assessment on targeted poverty alleviation can effectively avoid the disadvantage that local government plays as both athlete(i.e.performer of poverty alleviation work)and referee(i.e.referee for poverty alleviation effect)in poverty alleviation to ensure the truth of poverty alleviation,and therefore,it is an important part of the work to win the battle against poverty.Since 2016,the thirdparty assessment teams from colleges and universities for targeted poverty alleviation have achieved good results and performance in the assessment on both the effectiveness of targeted poverty alleviation work and the exit of poor counties in China,and they have made due contributions to the cause of poverty alleviation.However,as a new thing,third-party assessment obviously has some problems,mainly including the following:subjective understanding on the long-term nature of rural poverty alleviation is insufficient,and there is a lack of long-term considerations and related mechanism for third-party assessment;affected by policies and institutions,most of the existing third-party assessment teams from colleges and universities have not regarded third-party assessment of targeted poverty alleviation as a cause,and they lack the motivation to actively study the assessment business;and the third-party assessment staff from colleges and universities for targeted poverty alleviation have low stability and high mobility,not conducive to the long-term construction of assessment teams.In order to establish long-term poverty alleviation and prevention mechanisms,these issues must be addressed squarely and relevant countermeasures need to be taken actively to effectively build a long-term mechanism for building third-party assessment teams from colleges and universities for targeted poverty alleviation.