On Extend-Only Directed Posets and Derived Byzantine-Tolerant Replicated Data Types

We uncover the extend-only directed posets (EDP) structure as unification of recently discussed DAG-based Byzantine-tolerant conflict-free replicated data types (CRDT). We also derive an EDP-based key-value map, and give an outlook on an EDP-based systemic access control CRDT as formalization of the CRDT used in the Matrix messaging system

On Extend-Only Directed Posets and Derived Byzantine-Tolerant Replicated Data Types (Extended Version)

We uncover the extend-only directed posets (EDP) structure as a unification of recently discussed DAG-based Byzantine-tolerant conflict-free replicated data types (CRDT). We also show how a key-value map model can be derived from the EDP formulation, and give an outlook on an EDP-based systemic access control CRDT as a formalization of the CRDT used in the Matrix messaging system.Comment: With the inclusion of an appendix of a formalization and CRDT proof sketch of an EDP-based CRDT with systemic access control, this is an extended version of the paper presented at the 10th Workshop on Principles and Practice of Consistency for Distributed Data (PaPoC), 2023-05-08, Rome, Ital

On Extend-Only Directed Posets and Derived Byzantine-Tolerant Replicated Data Types

We uncover the extend-only directed posets (EDP) structure as unification of recently discussed DAG-based Byzantine-tolerant conflict-free replicated data types (CRDT). We also derive an EDP-based key-value map, and give an outlook on an EDP-based systemic access control CRDT as formalization of the CRDT used in the Matrix messaging system

Abrasive wear behaviour of 27MnB5 steel used in agricultural tines

Understanding the wear mechanisms in wear parts is a crucial element of tribological investigation, particularly in agricultural applications where the knowledge about abrasive micro-mechanisms of soil engaging tools are limited. In the current research, symmetrical skew wedge cultivator tines of 27MnB5 steel were wear tested to investigate the change in mass, linear dimensions, hardness and microstructure, aiming at prolonging the lifetime of these parts through design and material. The wear mechanisms were identified and characterized by non-contact 3D optical profilometry. Test results clearly shows a zone specific wear micro-mechanism based on the tine geometry. The cutting edge of the tine can be segmented into micro-cutting and micro-ploughing zone. Vickers hardness and microstructural analysis were performed on the cross-section of the sliding interface. Tribolayer was observed on the worn surface. Degree of penetration from the wear scratches was calculated to justify the wear micro-mechanisms. A Discrete Element Method (DEM) model was developed to investigate the soil flow during the tillage process. The model results and field test wear scars are in good agreement with each other with respect to the wear patterns

On Doing Things Intentionally

Recent empirical and conceptual research has shown that moral considerations have an influence on the way we use the adverb 'intentionally'. Here we propose our own account of these phenomena, according to which they arise from the fact that the adverb 'intentionally' has three different meanings that are differently selected by contextual factors, including normative expectations. We argue that our hypotheses can account for most available data and present some new results that support this. We end by discussing the implications of our account for folk psychology

On Doing Things Intentionally

Recent empirical and conceptual research has shown that moral considerations have an influence on the way we use the adverb 'intentionally'. Here we propose our own account of these phenomena, according to which they arise from the fact that the adverb 'intentionally' has three different meanings that are differently selected by contextual factors, including normative expectations. We argue that our hypotheses can account for most available data and present some new results that support this. We end by discussing the implications of our account for folk psychology

A Glimpse of the Matrix – Scalability issues of a new message-oriented data synchronization middleware

Matrix is a new message-oriented data synchronization middleware, used as a federated platform for near real-time decentralized applications. It features a novel approach for inter-server communication based on synchronizing message history by using a replicated data structure. We measured the structure of public parts in the Matrix federation as a basis to analyze the middleware\u27s scalability. We confirm that users are currently cumulated on a single large server, but find more small servers than expected. We then analyze network load distribution in the measured structure and identify scalability issues of Matrix\u27 group communication mechanism in structurally diverse federations