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Number of results: 9
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Abstract

Multiple input multiple output (MIMO) is a multiple antenna technology used extensively in wireless communication systems. With the ever increasing demand in high data rates, MIMO system is the necessity of wireless communication. In MIMO wireless communication system, where the multiple antennas are placed on base station and mobile station, the major problem is the constant power of base station, which has to be allocated to data streams optimally. This problem is referred as a power allocation problem. In this research, singular value decomposition (SVD) is used to decouple the MIMO system in the presence of channel state information (CSI) at the base station and forms parallel channels between base station and mobile station. This practice parallel channel ensures the simultaneous transmission of parallel data streams between base station and mobile station. Along with this, water filling algorithm is used in this research to allocate power to each data stream optimally. Further the relationship between the channel capacity of MIMO wireless system and the number of antennas at the base station and the mobile station is derived mathematically. The performance comparison of channel capacity for MIMO systems, both in the presence and absence of CSI is done. Finally, the effect of channel correlation because of antennas at the base stations and the mobile stations in the MIMO systems is also measured.

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Authors and Affiliations

Dalveer Kaur
Neeraj Kumar
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Abstract

In this work, the authors proposed a modification of the working space one-strand tundish adapted for slab casting process. Numerical simulations of liquid steel flow in the considered flow reactor were performed. The tundish is equipped with a dam with a multi-hole filter. Two variants of the filter hole arrangement were tested and their effect on the liquid steel flow hydrodynamic structure in the tundish was examined. The computer calculations results were verified by performing experiments on the water model. The result of numerical and physical simulations an RTD (Residence Time Distribution) type F curve was generated, which define the transition zone between the cast steel grades during the sequential casting process. The results of the researches showed that the modification of a dam with a multi-hole filter affects on the formation of the liquid steel flow hydrodynamic structure and the transition zone. Furthermore, examinations of the liquid steel refining ability in the considered tundish were carried out. The influence of the filter holes arrangement on the non-metallic inclusions flotation process to the slag phase and liquid steel filtration processes was checked. Numerical simulations were performed in the Ansys-Fluent computer program.

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Authors and Affiliations

M. Bartosiewicz
A. Cwudziński
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Abstract

A novel method of active noise control using adaptive radiation sound sources is investigated. A finite element model of a modal enclosed sound field is excited harmonically, representing a noise field in the low-frequency range. The control sources are comprised of elementary dipole sources for which the driving signals are adjusted by an optimization method. Two set-up cases of the proposed compound sources are investigated. The coupling of the control sources with the modal sound field is discussed. The simulated performance of the proposed method is compared with that of a system with distributed simple sources and the results show the effectiveness of the sources with adaptive radiation for active noise control in small enclosures.

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Authors and Affiliations

Marios Giouvanakis
Christos Sevastiadis
George Papanikolaou
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Abstract

The analysis of after reclamation dusts generated during the reclamation treatment of test portions of two kinds of polydispersive material in the Regmas device, is presented in the hereby paper. For the comparative purpose the fresh moulding sand marked as quartz sand „Sibelco” –1K 0.40/0.32/0.20, J88, >14000C, WK = 1.20 (acc. PN-83/H-11077), as well as the spent moulding sand, which was previously subjected to the primary reclamation and to dedusting, were used. Conditions of the process treatment were forced by the frequency of supplying the vibratory drive motors being successively 40, 50 and 60Hz for 5, 10 and 15 min. and by causing a diversified material flow through the functional system of the device (charging hopper, abrasive chamber acting as a buffer space). Two states of the process treatment, when a material was flowing through the chamber, were applied. In the first one, an intergranular surface abrasion of grains occurred as a result of the granular material circulation in the chamber forced by the vibratory drive. In the second one, the forced material flow was performed in the presence of crushing elements (steel balls), additionally introduced into the abrasive chamber. Analyses of the device influence were performed by determinations of the amount of dusts separated in the pneumatic classifier and analysis of their grain sizes by means of Analysette 22NanoTec.

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Authors and Affiliations

M. Skrzyński
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Abstract

This study aimed to analyse the effect of anthropogenic activities on the spatial distribution of total nitrogen (TN) and total phosphate (TP) in Lake Maninjau, Indonesia, during the dry season. Sampling was carried out at ten observation locations representative for various activities around the lake. Cluster analysis and ANOVA were used to classify pollutant sources and observe differences between TN and TP at each site. Concentrations of TN and TP are categorised as oligotrophic-eutrophic. The ANOVA showed spatially that some sampling locations, such as the Tanjung Sani River, floating net cages, and hydropower areas have different TN concentrations. At the same time, TP levels were consistently significantly different across sampling sites. ANOVA and cluster analysis confirmed that floating net cages were the first cluster and the primary contributor to TN and TP. The second and third clusters come from anthropogenic activities around the lake, such as agriculture, settlement, and livestock. The fourth cluster with the lowest TN and TP is the river that receives the anthropogenic activity load but has a high flow velocity. The cluster change analysis needs to be conducted when there are future changes in the composition of floating net cages, agriculture, and settlements.
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Authors and Affiliations

Puti S. Komala
1
ORCID: ORCID
Zulkarnaini Zulkarnaini
1
Roselyn I. Kurniati
2
Mhd Fauzi
3
ORCID: ORCID

  1. Universitas Andalas, Department of Environmental Engineering, 25163, Padang, Indonesia
  2. Universitas Universal, Department of Environmental Engineering, 29432, Batam, Indonesia
  3. Doctoral Student of Environmental Engineering, Institut Teknologi Bandung, 40132, Bandung, Indonesia
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Abstract

Spigelian hernia (SH) is a rare ventral interstitial hernia occurring through a defect in the transversus abdominis aponeurosis (Spigelian fascia). Spigelian fascia is found between the lateral border of the rectus abdominis muscle and the semilunar line, which extends from the costal cartilage to the pubic tubercle. In other words, Spigelian line is where the transversus abdominis muscle ends in an aponeurosis characterized by a congenital or acquired defect in the Spigelian aponeurosis. Pediatric cases of SH are either congenital or acquired due to trauma, previous surgery or increased intra-abdominal pressure. SH in combination with ipsilateral cryptorchidism may constitute a new syndrome, as such cases are extremely rare in the literature Th is new syndrome is characterized by the following congenital, ipsilateral disturbances: SH, absence of inguinal canal and gubernaculum and the homolateral testis found within the Spigelian hernia sac (a hernia sac containing undescended testis). Th e aim of this study is to emphasize some typical fi ndings of this specifi c entity, and, hence, the necessity for a thorough investigation of the origin of the SH.

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Authors and Affiliations

Ioannis Patoulias
Evangelia Rahmani
Dimitrios Patoulias
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Abstract

This work aims to create an ANN-based system for a musical improviser. An artificial improviser of "hearing" music will create a melody. The data supplied to the improviser is MIDItype musical data. This is the harmonic-rhythmic course, the background for improvisation, and the previously made melody notes. The harmonic run is fed into the system as the currently ongoing chord and the time to the next chord, while the supplied few dozen notes performed earlier will indirectly carry information about the entire run and the musical context and style. Improvisation training is carried out to check ANN as a correctlooking musical improvisation device. The improviser generates several hundred notes to be substituted for a looped rhythmicharmonic waveform and examined for quality.
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Authors and Affiliations

Jarosław Mazurkiewicz
1

  1. Wrocław University of Science and Technology, Faculty of Information and Communication Technology, Department of Computer Engineering
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Abstract

During a cruise of the fishing vessel m/t "Sagitta" around the Antarctic, the occurrence of DSL was noted in a small area of the Pacific sector of the Antarctic waters. The layers were found at depths of 50—150 m. Their main component was E. carlsbergi (family Myctophidae), whose maximum density was within the range of 219—437 x 10 -4 fish/m3.

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Authors and Affiliations

Tomasz B. Linkowski

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