Cross-Layer Adaptation with Safety-Assured Proactive Task Job Skipping

2021 ◽  
Vol 20 (5s) ◽  
pp. 1-25
Author(s):  
Zhilu Wang ◽  
Chao Huang ◽  
Hyoseung Kim ◽  
Wenchao Li ◽  
Qi Zhu

During the operation of many real-time safety-critical systems, there are often strong needs for adapting to a dynamic environment or evolving mission objectives, e.g., increasing sampling and control frequencies of some functions to improve their performance under certain situations. However, a system's ability to adapt is often limited by tight resource constraints and rigid periodic execution requirements. In this work, we present a cross-layer approach to improve system adaptability by allowing proactive skipping of task executions, so that the resources can be either saved directly or re-allocated to other tasks for their performance improvement. Our approach includes three novel elements: (1) formal methods for deriving the feasible skipping choices of control tasks with safety guarantees at the functional layer, (2) a schedulability analysis method for assessing system feasibility at the architectural layer under allowed task job skippings, and (3) a runtime adaptation algorithm that efficiently explores job skipping choices and task priorities for meeting system adaptation requirements while ensuring system safety and timing correctness. Experiments demonstrate the effectiveness of our approach in meeting system adaptation needs.

Author(s):  
Julie Roux ◽  
Katell Morin-Allory ◽  
Vincent Beroulle ◽  
Regis Leveugle ◽  
Lilian Bossuet ◽  
...  

2020 ◽  
Vol 110 (04) ◽  
pp. 220-225
Author(s):  
Matthias Schmidt ◽  
Janine Tatjana Maier ◽  
Mark Grothkopp

Produzierende Unternehmen stehen in einem dynamischen Umfeld vor der Herausforderung eine zunehmende Datenmenge effizienter zu verarbeiten. In diesem Zusammenhang werden häufig Ansätze des maschinellen Lernens (ML) diskutiert. Der Beitrag stellt eine umfassende Aufarbeitung des Stands der Forschung bezogen auf den Einsatz von ML-Ansätzen in der Produktionsplanung und -steuerung (PPS) bereit. Daraus lässt sich der Forschungsbedarf in den einzelnen Aufgabengebieten der PPS ableiten.   In a dynamic environment, manufacturing companies face the challenge of processing an increasing amount of data more efficiently. In this context, approaches of machine learning (ML) are often discussed. This paper provides a comprehensive review of the state of the art regarding the use of ML approaches in production planning and control (PPC). Based on this, the need for research in the individual task areas of PPC can be derived.


Author(s):  
Andriy Kovalenko ◽  
Ievgen Babeshko ◽  
Viktor Tokarev ◽  
Kostiantyn Leontiiev

This chapter describes an element base of new generation for NPP I&C, namely field programmable gate array (FPGA), and peculiarities of the FPGA application for designing safety critical systems. FPGA chips are modern complex electronic components that have been applied in nuclear power plants (NPPs) instrumentation and control systems (I&CSs) during the last 15-17 years. The advantages and some risks caused by application of the FPGA technology are analyzed. Safety assessment techniques of FPGA-based I&CSs and experience of their creation are described. The FPGA-based platform RadICS and its application for development of NPP I&CS is described.


Author(s):  
Minyoung Kim ◽  
Mark-Oliver Stehr ◽  
Carolyn Talcott ◽  
Nikil Dutt ◽  
Nalini Venkatasubramanian

2017 ◽  
Vol 8 (2) ◽  
Author(s):  
Fitria Ayu Lestari Niu ◽  
Lintje Kalangi ◽  
Linda Lambey

Abstract. This study aims to analyze the suitability of the implementation the local assets management with regulations, analyze the constraints faced in the management of local assets and efforts made for better management of regional assets. This is a qualitative study with case study approach. Data were obtained through in-depth interview technique, documentation study and observation. The result of this research shows that the local asset management in Bolaang Mongondow is implemented based on Regulation by Minister of Home Affairs No. 19 of 2016 which covers the process of planning needs and budgeting, procurement, use, utilization, security and maintenance, assessment, deletion, alienation, administration and coaching, supervision and control. But the process of destruction has not been conducted. It is because the local government has judged that there is no property belonging to the region being eligible to be destroyed. Additionally, there are obstacles encountered in asset management that are low compliance of regional apparatuses, lack of local regulations for local asset management, ineffective asset inventories, insufficient human resource competencies, lack of firm leadership commitments and resource constraints in the form of budgets and facilities in local assets management. Efforts have been conducted such as asset valuation, legal audit, asset inventory and improvement in leadership commitment. However, these efforts are required to be strongly supported by the regulation in the form of local regulations, improvement in compliance, attitude, perception, and responsibility for regional apparatus, assertiveness by the leadership, need a reward and punishment strategy for the performance of regional apparatus, involving the steward in the planning process and the use of SIMDA-BMD for the administration process in each regional work unit.Keywords: Local Asset Management, Compliance, Human Resources, Asset InventoriesAbstrak. Penelitian ini bertujuan untuk menganalisis kesesuaian pelaksanaan pengelolaan aset daerah dengan regulasi, menganalisis kendala yang dihadapi serta upaya yang dilakukan untuk memperbaiki pengelolaan aset daerah yang lebih baik. Penelitian ini menggunakan metode kualitatif dengan pendekatan studi kasus. Data diperoleh melalui teknik wawancara yang mendalam, studi dokumentasi dan observasi. Hasil penelitian menunjukkan bahwa pengelolaan aset daerah Kabupaten Bolaang Mongondow dilaksanakan berdasarkan Permendagri No. 19 Tahun 2016 yang meliputi proses perencanaan kebutuhan dan penganggaran, pengadaan, penggunaan, pemanfaatan, pengamanan dan pemeliharaan, penilaian, penghapusan, pemindahtanganan, penatausahaan serta pembinaan, pengawasan dan pengendalian. Namun proses pemusnahan belum dilakukan karena pemerintah daerah menilai bahwa belum ada barang milik daerah yang memenuhi syarat untuk dimusnahkan. Kendala yang ditemui dalam pengelolaan aset yaitu rendahnya kepatuhan aparatur daerah, belum adanya peraturan daerah yang mengatur proses pengelolaan aset daerah, inventarisasi aset yang belum efektif, kompetensi sumber daya manusia yang belum memadai, lemahnya komitmen pimpinan serta kurangnya sumber daya dalam bentuk anggaran dan fasilitas dalam pengelolaan aset daerah. Upaya yang dilakukan yaitu mengadakan penilaian aset, legal audit, inventarisasi aset dan perbaikan dalam komitmen pimpinan. Namun upaya ini masih perlu didukung dengan adanya regulasi dalam bentuk peraturan daerah, perbaikan dalam hal kepatuhan, sikap, persepsi, dan tanggung jawab aparatur daerah, ketegasan pimpinan, adanya strategi reward dan punishment atas kinerja aparatur daerah, melibatkan pengurus barang dalam proses perencanaan serta penggunaan SIMDA-BMD untuk proses penatausahaan pada masing-masing SKPD.Kata Kunci: Pengelolaan Aset Daerah, Kepatuhan, Sumber Daya Manusia, Inventarisasi Aset. 


2021 ◽  
Author(s):  
Xiaokang Han ◽  
Wenzhou Yan ◽  
Ting Liu

Abstract It has been widely accepted in the academic community that the Critical Chain Method (CCM) has significant advantages over the Critical Path Method (CPM) in solving the problem with resource constraints. However, this paper conducted a study on comparing the two methods of Critical Chain Method and Critical Path Method, and found that the only difference between those two methods lies in how to determine the priority of resources allocating, and on the assumption of not setting buffer zone, those two methods have no essential distinctions at all. By establishing the relationship between CCM and CPM, this paper also enriched and improved CCM to some extent, and pointed out that the buffer zone setting in CCM is merely subjective and short of scientificity. In the meantime, for the problem of unclear representation of critical chains, it proposed two ways of representing critical chains and related rules to follow. To verify the conclusion of this paper, further detailed case study of comparing CCM and CPM was performed. Affected by various uncertain factors, the project construction sequence is random, the total construction duration is random, and the critical chain is also random, so it is unable to determine how to direct construction. Aiming at the randomness of the critical chain, this article analyzed various uncertain factors of the critical chain, and on the basis of solving the critical chain sequence time, it proposed the approach to determine the completion probability of the total construction duration and control the construction of the critical chain to direct the construction, in the meantime, the inverse algorithm was adopted to determine of the construction duration under the condition of required completion probability.


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