Applied sciences

Bulletin of the Polish Academy of Sciences: Technical Sciences

Content

Bulletin of the Polish Academy of Sciences: Technical Sciences | Early Access

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Abstract

The conditions for accurately intercepting hypersonic vehicles by low-speed interceptors in the terminal guidance process are examined, considering the general form of a guidance scheme. First, based on the concept of the engagement geometry, three interception scenarios are established considering different manoeuvring configurations of the interceptors and hypersonic vehicle. Second, the boundary conditions for intercepting hypersonic vehicles (with speeds higher than those of the interceptors) are specified for the three scenarios, considering several factors: the speed, path angle, line-of-sight angle, and available overload of the interceptor; path angle and manoeuvrability of the hypersonic vehicle; and relative distance between the interceptor and vehicle. A series of simulations is performed to clarify the influence of each factor on the interceptor performance in the three interception scenarios. The challenges associated with accurately intercepting hypersonic vehicles by low-speed interceptors are summarised, and several recommendations for designing guidance laws are presented.
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Authors and Affiliations

Shuangxi Liu
ORCID: ORCID
Shijun Liu
Binbin Yan
ORCID: ORCID
Tong Zhang
Xu Zhang
Jie Yan
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Abstract

2 Business processes are omnipresent in nowadays economy: companies operate repetitively to achieve their goals, e.g., deliver goods, complete orders. The business process model is the key to understanding, managing, controlling, and verifying the operations of a company. Modeling of business processes may be a legal requirement in some market segments, e.g., financial in the European Union, and a prerequisite for certification, e.g., of the ISO-9001 standard. However, business processes naturally evolve, and continuous model adaptation is essential for rapid spot and reaction to changes in the process.The main contribution of this work is the Continuous Inductive Miner (CIM) algorithm that discovers and continuously adapts the process tree, an established representation of the process model, using the batches of event logs of the business process.CIM joins the exclusive guarantees of its two batch predecessors, the Inductive Miner (IM) and the Inductive Miner - directly-follows-based (IMd): perfectly fit and sound models, and single-pass event log processing, respectively. CIM offers much shorter computation times in the update scenario than IM and IMd. CIM employs statistical information to work around the need to remember event logs as IM does while guarantying the perfect fitness, contrary to IMd.
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Authors and Affiliations

Tomasz P. Pawlak
ORCID: ORCID
Bartosz Górka
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Abstract

The structural concept of dome dates back to the Pantheon in Rome. It is used as cover of many churches and mosques all around the world. Light solutions, with a well visible dome shaped truss skeleton, are often preferred in modern architecture. Base isolation techniques can be adopted to mitigate the seismic effects. The target of this contribution is to investigate the efficiency of different designs for the truss skeleton. To afford the problem, one has to assign the constraints, the materials and the geometry of the dome, its supporting structure and the isolation devices (number, locations, and type). The screening of the effects of different scheme assumptions on the structural behaviour provides a better insight to the problem.
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Authors and Affiliations

Sara Casciati
ORCID: ORCID
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Abstract

It is shown that in uncontrollable linear system = Ax + Bu it is possible to assign arbitrarily the eigenvalues of the closed-loop system with state feedbacks u = Kx, K ∈ ℜnm if rank [A B] = n. The design procedure consists in two steps. In the step 1 a nonsingular matrix  M ∈ ℜnm is chosen so that the pair (MA,MB) is controllable. In step 2 the feedback matrix K is chosen so that the closed-loop matrix Ac = A  − BK has the desired eigenvalues. The procedure is illustrated by simple example.

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Authors and Affiliations

Tadeusz Kaczorek
ORCID: ORCID

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