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Number of results: 18
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Abstract

Production rates for various activities and overall construction project duration are significantly influenced by crew formation. Crews are composed of available renewable resources. Construction companies tend to reduce the number of permanent employees, which reduces fixed costs, but at the same time limits production capacity. Therefore, construction project planning must be carried out by means of scheduling methods which allow for resource constrains. Authors create a mathematical model for optimized scheduling of linear construction projects with consideration of resources and work continuity constraints. Proposed approach enables user to select optimal crew formation under limited resource supply. This minimizes project duration and improves renewable resource utilization in construction linear projects. This paper presents mixed integer linear programming to model this problem and uses a case study to illustrate it.

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Authors and Affiliations

S. Biruk
P. Jaśkowski
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Abstract

The distribution of heavy metals in the bonom sediments has been determined, It has been shown that they are spaciously differentiated. The differentiation is a result of water movement, eutroficat ion, bioaccurnulation and anthropoprcsion processes. As a result of specific water movement the area of intensity of the heavy metals accumulation was created. This area (about 150 ha) is located in the northwest part of the reservoir. The maximal concentrations of heavy metals for this region are: for cadmium 30 mg Cd/kg, for nickel 55 mg Ni/kg, for chromium 130 mg Cr/kg, for lead 160 mg Pb/kg, for copper 1000 mg Cu/kg, for zinc 1300 mg Zn/kg. The localization of the most polluted areas is essential for possible reclamation procedures to improve water and overall ecosystem quality.
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Authors and Affiliations

Maciej Kostecki
Eligiusz Kowalski
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Abstract

The results of research on the role of water mass movements arising as a result of anthropoprcsion, in heavy metals arrangement in sediments have been presented on the example of dam reservoir in Rybnik. The carried out thermo-visual measurements of the thermally polluted Rybnik dam-reservoir revealed spatial diversification of water temperature. The zones of diverse dynamics of water mass movements have been shown, including the zone of intensive water flow and the zone of stagnation. [t has been proved that the values of these concentrations arc strongly diverse in space. This is the result of the cutrophication grade, bioaccumulation process, and anthropomixtion. As a result of specific water movement, which transports biomass inside the ecosystem, the zone, developed in which the transfer of heavy metals to the sediments is intensified. This zone of about 150 ha in area was located. The maximum concentrations of metals described in this area arc: for cadmium - 30 mg/kg, for nickel - 55 mg/kg, for chromium - 130 mg/kg, for lead - 160 mg/kg, for copper - 1 000 mg/kg, for zinc - 1300 mg/kg. In the case ofmobile fractions, potentially capable of freeing themselves from sediments the concentration values are: for cadmium - 14 mg/kg, for nickel - 15 mg/kg, for chromium - 4 mg/kg, for lead - 8 mg/kg, for copper - 100 mg/kg, for zinc - 600 mg/kg. The participation ofmobile fractions of metals in their total quantity was: for zinc - 46%, for cadmium - 46%, for nickel - 27%, for copper - 10%, for lead- 5%, for chromium - 3%. The relationship between the total concentrations of metals likewise their mobile forms and the content of organic matter in sediments, points to the role ofbiomass of plankton organisms and detritus as bio-sorbcnt in the process of transporting and transferring metals from water to sediments. With reference to water mass dislocation effect inside the reservoir under the influence of anthropogenic factor, in the situation when this factor is stronger than the factors which cause natural water movements, author suggests using the term anthropomixion.
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Authors and Affiliations

Maciej Kostecki
ORCID: ORCID
Eligiusz Kowalski
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Abstract

An accurate use of the ability to steer computer efficiency is essential from the database point of view. Effective resource allocation is dependent on the performance indicators gathered from running systems. There must be an appropriate balance between accurate measurements, performance indicators and speed of the reallocation algorithms of the computing resources. The extended measurement of efficiency which the authors propose for applications is: the average number of queries within a time unit for particular groups of users. This paper presents an analysis of using the Workload Manager utility in the AIX 5L operating system to improve the efficiency of applications in the MySQL database environment, and an analysis of methods which allows the use of Workload Manager for steering efficiency dynamically.
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Authors and Affiliations

Przemysław Rumik
Maciej Młyński
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Abstract

A large amount of electric vehicles (EVs) charging load will bring significant impact to the power system. An appropriate resource allocation strategy is required for securing the power system safety and satisfying EVs charging demand. This paper proposed a power coordination allocation strategy of EVs’ in distribution systems. The strategy divides the allocation into two stages. The first stage is based on scores assigned to EVs through an entropy method, whereas the second stage allocates energy according to EV’s state of charge. The charging power is delivered in order to maximize EV users’ satisfaction and fairness without violation of grid constraints. Simulation on a typical power-limited residential distribution network proves the effectiveness of the strategy. The analysis re- sults indicate that compared with traditional methods, EVs, which have higher charging requirement and shorter available time will get more energy delivered than others. The root- mean-square-error (RMSE) and standard-deviation (SD) results prove the effectiveness of the methodology for improving the balance of power delivery.

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Authors and Affiliations

Yi Wang
Xiu Ma
Feihong Wang
Xingzhe Hou
Hongliang Sun
Ke Zheng
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Abstract

Energy and spectral efficiency are the main challenges in 5th generation of mobile cellular networks. In this paper, we propose an optimization algorithm to optimize the energy efficiency by maximizing the spectral efficiency. Our simulation results show a significant increase in terms of spectral efficiency as well as energy efficiency whenever the mobile user is connected to a low power indoor base station. By applying the proposed algorithm, we show the network performance improvements up to 9 bit/s/Hz in spectral efficiency and 20 Gbit/Joule increase in energy efficiency for the mobile user served by the indoor base station rather than by the outdoor base station.

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Authors and Affiliations

Bujar Krasniqi
Blerim Rexha
Betim Maloku
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Abstract

The unpredictable and huge data generation nowadays by smart devices from IoT and mobile Crowd Sensing applications like (Sensors, smartphones, Wi-Fi routers) need processing power and storage. Cloud provides these capabilities to serve organizations and customers, but when using cloud appear some limitations, the most important of these limitations are Resource Allocation and Task Scheduling. The resource allocation process is a mechanism that ensures allocation virtual machine when there are multiple applications that require various resources such as CPU and I/O memory. Whereas scheduling is the process of determining the sequence in which these tasks come and depart the resources in order to maximize efficiency. In this paper we tried to highlight the most relevant difficulties that cloud computing is now facing. We presented a comprehensive review of resource allocation and scheduling techniques to overcome these limitations. Finally, the previous techniques and strategies for allocation and scheduling have been compared in a table with their drawbacks.
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Authors and Affiliations

Abbas M. Ali Al-muqarm
1 2
Naseer Ali Hussien
3

  1. University of Kufa, Iraq
  2. Computer Technical Engineering Department, The Islamic University, Iraq
  3. Alayen University, Iraq
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Abstract

Small and medium-sized enterprises (SMEs) are facing barriers to grow due to the lack of structured procedures for upgrading and allocating the limited resources. To overcome these drawbacks and to improve business capabilities, a structured framework to conduct a comprehensive diagnostic and upgrading study is presented in this paper. The proposed framework involves four phases. First, the external and internal strategic factors, which can affect the enterprises’ performance are evaluated using strategic planning and assessment tools. Second, key upgrade performance indicators are developed and evaluated using multi-attribute rating techniques to guide, evaluate, and track progress of upgrading process. Third, a set of upgrade strategies are generated and evaluated using resource allocation model. Finally, a periodic re-evaluation plan is introduced to monitor the implementation progress. The developed framework for performance evaluation and upgrading is suitable to be used as a structured know-how procedure in manufacturing enterprises and can support entrepreneurs in their strategic decisions. To validate the proposed framework, a data set was collected from a local housecore company. As a result, one package of the efficient frontier strategies that represents the best use of resources was proposed for implementation.
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Authors and Affiliations

Amer Momani
Tarek Al-Hawari
Sufyan Tahat
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Abstract

Small construction objects are often built by standard task teams. The problem is, how to allocate these teams to individual works? To solve the problem of allocation three methods have been developed. The first method allows to designate optimal allocation of teams to the individual works in deterministic conditions of implementation. As a criterion of the optimal allocation can be applied: “the minimization of time” or “the minimization of costs” of works execution. The second method has been developed analogously for both criteria but for stochastic conditions and for the stochastic data. The third method allows to appoint a compromise allocation of teams. In this case, the criteria “the minimization of time” and “the minimization of costs” are considered simultaneously. The method can be applied in deterministic or stochastic conditions of works implementation. The solutions of the allocation problems which have been described allow to designate the optimal allocation of task teams and to determine the schedule and cost of works execution.

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Authors and Affiliations

T. Kasprowicz
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Abstract

The aim of the presented paper was to verify the impact of Dynamic PUCCH Resource Allocation Algorithm of the LTE cellular system on the maximum uplink cell throughput and call setup success rate-CSSR. Paper includes the laboratorytestbeddescription and presents the results of an experiment confirming the improvement of both key performance indicatorsKPIs.Apart from the presentation of the Dynamic PUCCH Resource allocation algorithm, the paper also includes a description of legacy LTE uplink (PUCCH and PUSCH) channels dimensioning process thus filling the gap of such a tutorial in the available literature.

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Authors and Affiliations

Maciej Czerniecki
Jacek Wszołek
Marek Sikora
ORCID: ORCID
Wiesław Ludwin
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Abstract

A novel method to improve the performance of the frequency band is cognitive radio that was introduced in 1999. Due to a lot of advantages of the OFDM, adaptive OFDM method, this technique is used in cognitive radio (CR) systems, widely. In adaptive OFDM, transmission rate and power of subcarriers are allocated based on the channel variations to improve the system performance. This paper investigates adaptive resource allocation in the CR systems that are used OFDM technique to transmit data. The aim of this paper is to maximize the achievable transmission rate for the CR system by considering the interference constraint. Although secondary users can be aware form channel information between each other, but in some wireless standards, it is impossible for secondary user to be aware from channel information between itself and a primary user. Therefore, due to practical limitation, statistical interference channel is considered in this paper. This paper introduces a novel suboptimal power allocation algorithm. Also, this paper introduces a novel bit loading algorithm. In the numerical results sections, the performance of our algorithm is compared by optimal and conventional algorithms. Numerical results indicate our algorithm has better performance than conventional algorithms while its complexity is less than optimal algorithm.

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Authors and Affiliations

Shirin Razmi
Naser Parhizgar
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Abstract

In this study, the concepts of simultaneous user association and resource allocation in non-orthogonal multiple access systems have been investigated. Subscribers are randomly distributed in them. In the paper, a novel cooperative energy harvesting model is introduced so that user equipment near to the base stations acts as relay for further subscribers. In order to consider the local limitations of alternative energy resources, it was assumed that alternative energy would be shared among the base stations by means of the dynamic grid network. In this architecture, non-orthogonal resource allocation and user association frameworks should be reconfigured because conventional schemes use orthogonal multiple access. Hence, this paper suggests a novel approach to joint optimum cooperative power allocation and user association techniques to achieve a maximum degree of energy efficiency for the whole system in which the quality of experience parameters are assumed to be bounded during multi-cell multicast sessions. The model was also modified to develop joint multi-layered resource control and user association that can distinguish the service pattern in cooperative energy heterogeneous systems with non-orthogonal multiple access to obtain more resource optimality than in the current approaches. The effectiveness of the suggested approach is confirmed by numerical results. Also, the results reveal that non-orthogonal multiple access can provide greater energy efficiency than the conventional orthogonal multiple access approaches such as e.g. the MAX-SINR scheme.

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Authors and Affiliations

S.H. HosseiniNazhad
M. Shafieezadeh
A. Ghanbari
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Abstract

Elastic optical networking is a potential candidate to support dynamic traffic with heterogeneous data rates and variable bandwidth requirements with the support of the optical orthogonal frequency division multiplexing technology (OOFDM). During the dynamic network operation, lightpath arrives and departs frequently and the network status updates accordingly. Fixed routing and alternate routing algorithms do not tune according to the current network status which are computed offline. Therefore, offline algorithms greedily use resources with an objective to compute shortest possible paths and results in high blocking probability during dynamic network operation. In this paper, adaptive routing algorithms are proposed for shortest path routing as well as alternate path routing which make routing decision based on the maximum idle frequency slots (FS) available on different paths. The proposed algorithms select an underutilized path between different choices with maximum idle FS and efficiently avoids utilizing a congested path. The proposed routing algorithms are compared with offline routing algorithms as well as an existing adaptive routing algorithm in different network scenarios. It has been shown that the proposed algorithms efficiently improve network performance in terms of FS utilization and blocking probability during dynamic network operation.

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Authors and Affiliations

Akhtar Nawaz Khan
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Abstract

In cellular networks, cells are grouped more densely around highly populated areas to provide more capacity. Antennas are pointed in accordance with local terrain and clutter to reduce signal shadows and interference. Hardware parameters are easily set during installation but difficult to change thereafter. In a dynamic environment of population migration, there is need to continuously tune network parameters to adapt the network performance. Modern mobile equipment logs network usage patterns and statistics over time. This information can be used to tune soft parameters of the network. These parameters may include frequency channel assignment or reuse, and transmitter radiation power assignment to provide more capacity on demand. The paper proposes that by combining the frequency and power assignments, further optimisation in resource allocation can be achieved over a traditional frequency assignment. The solution considers the interference, traffic intensity and use of priority flags to bias some edges. An Edge Weight Power and Frequency Assignment Algorithm is presented to solve the resource allocation problem in cellular networks. The paper also analyses the performance improvements obtained over that of the Edge Weight Frequency Assignment Algorithm. The results show that the proposed algorithm improves the performance of the Edge Weight Frequency Assignment Algorithm depending on the initial structure of the graph.

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Authors and Affiliations

O.S. Pharatlhatlhe
J.S.J. Daka
E. Gower
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Abstract

Appropriate product categorization in distribution centres is important for business success because of the possibility of intuitive product finding by the picker and increased product movement. Both of these factors result in the operational efficiency of the distribution centre. The goal of this paper is to explore a model of shelf space dimensioning of storage location on a rack with vertical and horizontal product categorization in a distribution centre, where the aim is to increase total product movement/profit from all shelves of the rack. This is controlled by a packer who must complete orders by getting the goods from shelves and picking them to the container. In this problem, we develop two heuristics and compare the archived results to the CPLEX solver. The average profit ratios of both heuristics are high and approximately equal to 99%. In 10 cases, optimal solutions have been found by heuristics.
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Authors and Affiliations

Kateryna Czerniachowska
1
ORCID: ORCID
Radosław Wichniarek
2
ORCID: ORCID
Krzysztof Żywicki
2
ORCID: ORCID

  1. Wroclaw University of Economics and Business, Wroclaw, Poland
  2. Poznan University of Technology, Poznan, Poland
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Abstract

Distribution centres are the important elements of modern supply chains. A distribution centre stores and ships products. In this paper, we investigate the model of the dimensioning of shelf space on the rack with vertical and horizontal product categorisation in a distribution centre, where the objective is to maximise the total product movement/profit from all shelves of the rack which is being managed by a packer who needs to complete orders selecting the products from the shelves and picking them to the container. We apply two newly developed heuristics to this problem and compare the results to the optimal solution found by the CPLEX solver. There are 8 steering parameters that allow for reducing the search space implemented in heuristics. Among them are parameters that decrease the number of products on the shelves, the category with a range for assigning most space for the most profitable products within the category; two versions of steering parameters for the number of generated product allocations, the step parameters for the intensity of solution diversification, and the movement/profit below which the solutions are not generated. The computational results are presented and indicate that higher-quality solutions can be obtained using the new heuristics. In 10 from 15 tests, both heuristics can find optimal solutions without exploring the whole solution space. For the rest test sets, the solutions received by heuristics are not less than 92.58%.
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Authors and Affiliations

Kateryna Czerniachowska
1
ORCID: ORCID
Radosław Wichniarek
2
ORCID: ORCID
Krzysztof Żywicki
2
ORCID: ORCID

  1. Wroclaw University of Economics and Business, Wroclaw, Poland
  2. Poznan University of Technology, Poznan, Poland
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Abstract

The fourth industrial revolution has resulted in technology advancements in the manufacturing industry. However, the innovation potential embedded in these technologies should be unlocked by a viable application, i.e., the business model (BM). The BM as a holistic concept featuring different interacting elements is thus emerging as a promising vehicle for innovation. Current BM research describes the entire domain but lacks depth in the characterization of its individual components. This paper investigates the available manufacturing literature through the lens of the BM concept performing a scientometric analysis. The results are presented in a relational framework that provides an in-depth characterization of the manufacturing element of the BM and highlights identified connections that link the BM components. This is the basis for tools that will support firms in developing manufacturing portfolios aligned with their strategic goals.
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Authors and Affiliations

Eleonora Boffa
1
ORCID: ORCID
Antonio Maffei
1
ORCID: ORCID

  1. Production Engineering, KTH – The Royal Institute of Technology, Sweden
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Abstract

Hybrid pixel radiation detectors with a direct photon-to-charge conversion working in a single photon counting mode have gained increasing attention due to their high dynamic range and noiseless imaging. Since sensors of different materials can be attached to readout electronics, they enable work with a wide range of photon energies. The charge-sharing effect observed in segmented devices, such as hybrid pixel detectors, is a phenomenon that deteriorates both spatial resolution and detection efficiency. Algorithms that allow the detection of a photon irrespective of the charge-sharing effect are proposed to overcome these limitations. However, the spatial resolution of the detector can be further improved beyond the resolution determined by the pixel size if information about the charge proportions collected by neighbouring pixels is used to approximate the interaction position. In the article, an approach to achieve a subpixel resolution in a hybrid pixel detector working in the single photon counting mode is described. Requirements and limitations of digital inter-pixel algorithms which can be implemented on-chip are studied. In the simulations, the factors influencing the detector resolution are evaluated, including size of a charge cloud, number of virtual pixel subdivisions, and detector parameters.
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Bibliography

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  7. Ballabriga, R. et al. The Medipix3RX: a high resolution, zero dead-time pixel detector readout chip allowing spectroscopic imaging. Instrum. 8, C02016–C02016 (2013). https://doi.org/10.1088/1748-0221/8/02/C02016
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Authors and Affiliations

Aleksandra Krzyżanowska
1
ORCID: ORCID
Robert Szczygieł
1
ORCID: ORCID

  1. AGH University of Science and Technology, 30 A. Mickiewicza Ave., 30-059 Krakow, Poland

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