Advanced Radio Resource Management for Multi Antenna Packet Radio Systems

In this paper, we propose fairness-oriented packet scheduling (PS) schemes with power-efficient control mechanism for future packet radio systems. In general, the radio resource management functionality plays an important role in new OFDMA based networks. The control of the network resource division among the users is performed by packet scheduling functionality based on maximizing cell coverage and capacity satisfying, and certain quality of service requirements. Moreover, multiantenna transmit-receive schemes provide additional flexibility to packet scheduler functionality. In order to mitigate inter-cell and co-channel interference problems in OFDMA cellular networks soft frequency reuse with different power masks patterns is used. Stemming from the earlier enhanced proportional fair scheduler studies for single-input multiple-output (SIMO) and multiple-input multipleoutput (MIMO) systems, we extend the development of efficient packet scheduling algorithms by adding transmit power considerations in the overall priority metrics calculations and scheduling decisions. Furthermore, we evaluate the proposed scheduling schemes by simulating practical orthogonal frequency division multiple access (OFDMA) based packet radio system in terms of throughput, coverage and fairness distribution among users. As a concrete example, under reduced overall transmit power constraint and unequal power distribution for different sub-bands, we demonstrate that by using the proposed power-aware multi-user scheduling schemes, significant coverage and fairness improvements in the order of 70% and 20%, respectively, can be obtained, at the expense of average throughput loss of only 15%.Comment: 14 Pages, IJWM

Minimum Description Length Principle in Discriminating Marginal Distributions

2010 Mathematics Subject Classification: 94A17, 62B10, 62F03.In this paper the MDL principle is explored in discriminating between a model with normal marginal distributions vs a model with Student-T marginal distributions. The shape complexity of a distribution is defined with insights from the closed-form solution for model complexity for normal distribution. An optimised numerical approach for the Student-T distribution is devised with the aim of extending it to the fat-tailed distributions commonly found in econometric time series

Параметри на лактационната крива в зависимост от продължителността на лактация при биволици от две различни системи на отглеждане

Buffaloes from intensive (farm 1 - Fm1; 438 normal, 115 short lactations) and pasture (farm 2 - Fm2; 330 + 58 lactations) system were assigned to study lactation curve via ANOVA (LSMLMW and MIXMDL) per each 10-day period (“tenday”), as well as overall (PI1) and post-peak (PIP) persistency. Greatest is the effect of parity and season, also of year on 2nd-12th tenday. Persistency is affected by parity, year and season of calving, and especially by peak month and DIM (P≤0.001). The curves showed peak averagely at 2nd tenday in both herds. Compared to the buffaloes on pasture, Fm1 has significantly lower milk in initial two and in 15th to 21st tendays, defining slower decline to mid-lactation and faster after that. These differences in the curves predetermine a non-significant difference in PI1 between Fm1 and Fm2 (0.932 and 0.940) and a significant but still small superiority in PIP of Fm2 (0.893) over Fm1 (0.880). The lactations below 210 days are 17.8%, persistency being 0.859 to 0.742, and peak by 17 to 32% worse than normal lactation. Long and very long lactations’ persistency is 0.923 and 0.950. Only very long lactations have а typical curve – 4th tenday peak, by 10% lower than normal lactation.Бяха включени биволици от интензивна (Fm1 – 438 нормални и 115 къси лактации) и пасищна (Fm2 - 330 + 58 лактации) технология на отглеждане, за проучване на лактационната крива чрез ANOVA (LSMLMW и MIXMDL) за всяка 10-дневка, както и на общото (PI1) и след-пиково (PIP) постоянство. Най-значим е ефектът на поредната лактация и сезона,, както и на годината за 2-ра–12-та десетдневка. Постоянството се влияе от поредната лактация, годината, сезона, и особено от пиковия месец и дойните дни (P≤0.001). Пикът е средно през 2-ра десетдневка в двете стада. В сравнение с биволиците на паша, Fm1 има достоверно по-ниска млечност в първите две и в 15та–21ва десетдневка, дефинирайки по-бавен спад до средата на лактацията и по-бърз след това. Тези разлики в кривите предопределят недостоверна разлика в PI1 между Fm1 и Fm2 (0.932 и 0.940) и и малко но достоверно превъзходство в PIP на Fm2 (0.893) спрямо Fm1 (0.880). Лактациите под 210 дни съставляват 17,8%, като постоянството е от 0,859 до 0,742, а пика е със 17 до 32% по-нисък от нормалната лактация. Постоянството на дългите и много дългите лактации е 0,923 и 0,950. Само много дългите лактации имат типична крива – пик в четвърто десетдневие, с 10% по-нисък от нормалната лактация

Параметри на лактационната крива в зависимост от продължителността на лактация при биволици от две различни системи на отглеждане

Buffaloes from intensive (farm 1 - Fm1; 438 normal, 115 short lactations) and pasture (farm 2 - Fm2; 330 + 58 lactations) system were assigned to study lactation curve via ANOVA (LSMLMW and MIXMDL) per each 10-day period (“tenday”), as well as overall (PI1) and post-peak (PIP) persistency. Greatest is the effect of parity and season, also of year on 2nd-12th tenday. Persistency is affected by parity, year and season of calving, and especially by peak month and DIM (P≤0.001). The curves showed peak averagely at 2nd tenday in both herds. Compared to the buffaloes on pasture, Fm1 has significantly lower milk in initial two and in 15th to 21st tendays, defining slower decline to mid-lactation and faster after that. These differences in the curves predetermine a non-significant difference in PI1 between Fm1 and Fm2 (0.932 and 0.940) and a significant but still small superiority in PIP of Fm2 (0.893) over Fm1 (0.880). The lactations below 210 days are 17.8%, persistency being 0.859 to 0.742, and peak by 17 to 32% worse than normal lactation. Long and very long lactations’ persistency is 0.923 and 0.950. Only very long lactations have а typical curve – 4th tenday peak, by 10% lower than normal lactation.Бяха включени биволици от интензивна (Fm1 – 438 нормални и 115 къси лактации) и пасищна (Fm2 - 330 + 58 лактации) технология на отглеждане, за проучване на лактационната крива чрез ANOVA (LSMLMW и MIXMDL) за всяка 10-дневка, както и на общото (PI1) и след-пиково (PIP) постоянство. Най-значим е ефектът на поредната лактация и сезона,, както и на годината за 2-ра–12-та десетдневка. Постоянството се влияе от поредната лактация, годината, сезона, и особено от пиковия месец и дойните дни (P≤0.001). Пикът е средно през 2-ра десетдневка в двете стада. В сравнение с биволиците на паша, Fm1 има достоверно по-ниска млечност в първите две и в 15та–21ва десетдневка, дефинирайки по-бавен спад до средата на лактацията и по-бърз след това. Тези разлики в кривите предопределят недостоверна разлика в PI1 между Fm1 и Fm2 (0.932 и 0.940) и и малко но достоверно превъзходство в PIP на Fm2 (0.893) спрямо Fm1 (0.880). Лактациите под 210 дни съставляват 17,8%, като постоянството е от 0,859 до 0,742, а пика е със 17 до 32% по-нисък от нормалната лактация. Постоянството на дългите и много дългите лактации е 0,923 и 0,950. Само много дългите лактации имат типична крива – пик в четвърто десетдневие, с 10% по-нисък от нормалната лактация

Fairness-Oriented and QoS-Aware Radio Resource Management in OFDMA Packet Radio Networks: Practical Algorithms and System Performance

During the last two decades, wireless technologies have demonstrated their importance in people’s personal communications but also as one of the fundamental drivers of economic growth, first in the form of cellular networks (2G, 3G and beyond) and more recently in terms of wireless computer networks (e.g. Wi-Fi,) and wireless Internet connectivity. Currently, the development of new packet radio systems is evolving, most notably in terms of 3GPP Long Term Evolution (LTE) and LTE-Advanced, in order to utilize the available radio spectrum as efficiently as possible. Therefore, advanced radio resource management (RRM) techniques have an important role in current and emerging future mobile networks. In all wireless systems, the data throughput and the average data delay performance, especially in case of best effort services, are greatly degraded when the traffic-load in the system is high. This is because the radio resources (time, frequency and space) are shared by multiple users. Another big problem is that the transmission performance can vary heavily between different users, since the channel state greatly depends on the communication environment and changes therein. To solve these challenges, new major technology innovations are needed. This thesis considers new practical fairness-oriented and quality-of-service (QoS) -aware RRM algorithms in OFDMA-based packet radio networks. Moreover, using UTRAN LTE radio network as application example, we focus on analyzing and enhancing the system-level performance by utilizing state-of-the-art waveform and radio link developments combined with advanced radio resource management methods. The presented solutions as part of RRM framework consist of efficient packet scheduling, link adaptation, power control, admission control and retransmission mechanisms. More specifically, several novel packet scheduling algorithms are proposed and analyzed to address these challenges. This dissertation deals specifically with the problems of QoS provisioning and fair radio resource distribution among users with limited channel feedback, admission and power control in best effort and video streaming type traffic scenarios, and the resulting system-level performance. The work and developments are practically-oriented taking aspects like finite channel state information (CSI), reporting delays and retransmissions into account. Consequently, the multi-user diversity gain with opportunistic frequency domain packet scheduling (FDPS) is further explored in spatial domain by taking the multiantenna techniques and spatial division multiplexing functionalities into account. Validation and analysis of the proposed solutions is performed through extensive system level simulations modeling the behavior and operation of a complete multiuser cell in the overall network. Based on the obtained performance results, it is confirmed that greatly improved fairness can be fairly easily built in to the scheduling algorithm and other RRM mechanisms without considerably degrading e.g. the average cell throughput. Moreover, effective QoS-provisioning framework in video streaming type traffic scenarios demonstrate the effectiveness of the presented solutions as increased system capacity measured in terms of the number of users or parallel streaming services supported simultaneously by the network

Le gène hairless de la souris : Fonctions à la racine du poil et au coeur d’une subtile pléiotropie

Le gène hairless (hr) des mammifères code pour une protéine nucléaire impliquée dans le contrôle du renouvellement du follicule pileux. Cette protéine est un cofacteur de récepteurs nucléaires d’hormones qui régulent la transcription de gènes cibles au cours de la différentiation de l’épiderme et du cycle du poil. La protéine Hairless (HR) fait partie de grands complexes multiprotéiques capables de réprimer la transcription, en association avec des facteurs de remodelage de la chromatine comme les histones désacétylases. Chez les mammifères, le locus hairless est la cible de nombreuses mutations alléliques dont les effets sont pléiotropiques. Ces altérations entraînent l’apparition d’un phénotype cutané complexe, caractérisé par la perte progressive et irréversible d’un pelage d’apparence normale au cours des premières semaines de vie post-natale. L’analyse de la littérature sur le gène hairless chez la souris et chez l’homme permet d’attribuer des différences morphologiques spécifiques à chaque mutant, aussi bien au niveau de l’épiderme et du follicule pileux que dans d’autres tissus où le gène est exprimé au cours du développement. Ces résultats suggèrent que l’intégrité du gène hairless est requise pour le déroulement correct de la morphogenèse d’organes aussi différents que l’épiderme, l’oreille interne, l’ovaire ou le thymus. Le gène hairless semble ainsi faire partie de circuits et de cascades d’interactions géniques dont le contrôle moléculaire est fondamentalement inconnu. La variété des phénotypes alléliques souligne l’importance de l’analyse moléculaire du locus hairless pour identifier les altérations géniques impliquées dans les différentes mutations détectées. Les recherches concernant la mutation hairless ont été particulièrement dynamiques pendant les dernières années, depuis que l’homologue de ce gène a pu être mis en évidence chez l’homme. Cependant, un bon nombre de questions reste en suspens, notamment quant au site exact d’activité du gène hairless au sein des nombreuses populations cellulaires du follicule pileux, son rôle précis au cours de la morphogenèse, sa localisation au sein des voies de signalisation, ainsi que l’identité des partenaires et des cibles de la protéine Hairless.The hairless gene in mammals encodes a nuclear factor that is highly expressed in skin and appears to control hair follicle integrity and cycling. In the absence of a normal and functional Hairless (Hr) protein, the hair bulb undergoes premature apoptosis during the first catagen stage of the hair cycle. The most striking effects of the mutation are loss of hair follicles and formation of epidermal utricles and dermal cysts. The hairless gene expression appears to be widespread and temporally regulated. The gene is strongly expressed in different compartments of the brain. Hairless mRNAs were detected in cartilage, gonads, thymus and colon. In addition to alopecia, hairless mice strains show subtle defects in the development and differentiation of various tissues and organs. The Hr protein is localised in cell nuclei and functions as a transcriptional regulator. Although its role has not been resolved in molecular terms, it was demonstrated that Hr is able to interact with multiple nuclear hormone receptors. Hr seems to be a part of a large multiprotein complex capable to repress transcription by its association to chromatin remodelling factors such as histone deacetylases. Recent experimental data suggest that Hr might be involved in Hox gene regulation, cell adhesion modulation and progenitor cells identity. At least in the skin, but probably in other organs, the Hr repressor seems to be responsible for the timing of epithelial cells differentiation

Free thyroxine in needle washout after fine needle aspiration biopsy of toxic thyroid nodules

The main diagnostic tool for toxic adenomas (TA) is radionuclide imaging indicated in patients with evidence of thyroid nodules in combination with thyrotoxic syndrome. Thyroid ultrasound and fine-needle aspiration biopsy (FNAB) are widely used for the valuation of thyroid masses. There is no literature data concerning the utility of FNAB and related tests for the diagnosis of hyperfunctioning thyroid nodules. The purpose of this study is to determine the levels of free thyroxine (FT4) in the needle washout after FNAB of hot thyroid nodules. The results of our study show that the FT4 levels in needle washout from TA were significantly higher than the surrounding parenchyma and correlated with the hormonal changes in patients with thyroid hyperfunctioning nodules. Further studies on a large number of patients are needed to refine the diagnostic value of this method and evaluate its importance in quantitative risk assessment of thyroid autonomy.The main diagnostic tool for toxic adenomas (TA) is radionuclide imaging indicated in patients with evidence of thyroid nodules in combination with thyrotoxic syndrome. Thyroid ultrasound and fine-needle aspiration biopsy (FNAB) are widely used for the valuation of thyroid masses. There is no literature data concerning the utility of FNAB and related tests for the diagnosis of hyperfunctioning thyroid nodules. The purpose of this study is to determine the levels of free thyroxine (FT4) in the needle washout after FNAB of hot thyroid nodules. The results of our study show that the FT4 levels in needle washout from TA were significantly higher than the surrounding parenchyma and correlated with the hormonal changes in patients with thyroid hyperfunctioning nodules. Further studies on a large number of patients are needed to refine the diagnostic value of this method and evaluate its importance in quantitative risk assessment of thyroid autonomy

The branchial Hox code and its implications for gene regulation, patterning of the nervous system and head evolution

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Highly Asynchronous and Asymmetric Cleavage Divisions Accompany Early Transcriptional Activity in Pre-Blastula Medaka Embryos

In the initial phase of development of fish embryos, a prominent and critical event is the midblastula transition (MBT). Before MBT cell cycle is rapid, highly synchronous and zygotic gene transcription is turned off. Only during MBT the cell cycle desynchronizes and transcription is activated. Multiple mechanisms, primarily the nucleocytoplasmic ratio, are supposed to control MBT activation. Unexpectedly, we find in the small teleost fish medaka (Oryzias latipes) that at very early stages, well before midblastula, cell division becomes asynchronous and cell volumes diverge. Furthermore, zygotic transcription is extensively activated already after the 64-cell stage. Thus, at least in medaka, the transition from maternal to zygotic transcription is uncoupled from the midblastula stage and not solely controlled by the nucleocytoplasmic ratio

Genome-wide occupancy links Hoxa2 to Wnt–β-catenin signaling in mouse embryonic development

The regulation of gene expression is central to developmental programs and largely depends on the binding of sequence-specific transcription factors with cis-regulatory elements in the genome. Hox transcription factors specify the spatial coordinates of the body axis in all animals with bilateral symmetry, but a detailed knowledge of their molecular function in instructing cell fates is lacking. Here, we used chromatin immunoprecipitation with massively parallel sequencing (ChIP-seq) to identify Hoxa2 genomic locations in a time and space when it is actively instructing embryonic development in mouse. Our data reveals that Hoxa2 has large genome coverage and potentially regulates thousands of genes. Sequence analysis of Hoxa2-bound regions identifies high occurrence of two main classes of motifs, corresponding to Hox and Pbx–Hox recognition sequences. Examination of the binding targets of Hoxa2 faithfully captures the processes regulated by Hoxa2 during embryonic development; in addition, it uncovers a large cluster of potential targets involved in the Wnt-signaling pathway. In vivo examination of canonical Wnt–β-catenin signaling reveals activity specifically in Hoxa2 domain of expression, and this is undetectable in Hoxa2 mutant embryos. The comprehensive mapping of Hoxa2-binding sites provides a framework to study Hox regulatory networks in vertebrate developmental processes