4,252 research outputs found

    What does Hirsch index evolution explain us? A case study: Turkish Journal of Chemistry

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    The evolution of Turkish Journal of Chemistry (Turk J. Chem) Hirsch index (h-index) over the period 1995-2005 is studied and determined in the case of the self and without self-citations. It is seen that the effect of Hirsch index of Turk J. Chem has a highly positive trend during the last five years. It proves that Turk J. Chem is improving itself both in quantity and quality since h-index reflects peer review, and peer review reflects research quality of a journal.Comment: 5 pages, 3 figure

    Low Power Analog-to-Digital Conversion in Millimeter Wave Systems: Impact of Resolution and Bandwidth on Performance

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    The wide bandwidth and large number of antennas used in millimeter wave systems put a heavy burden on the power consumption at the receiver. In this paper, using an additive quantization noise model, the effect of analog-digital conversion (ADC) resolution and bandwidth on the achievable rate is investigated for a multi-antenna system under a receiver power constraint. Two receiver architectures, analog and digital combining, are compared in terms of performance. Results demonstrate that: (i) For both analog and digital combining, there is a maximum bandwidth beyond which the achievable rate decreases; (ii) Depending on the operating regime of the system, analog combiner may have higher rate but digital combining uses less bandwidth when only ADC power consumption is considered, (iii) digital combining may have higher rate when power consumption of all the components in the receiver front-end are taken into account.Comment: 8 pages, 6 figures, in Proc. of IEEE Information Theory and Applications Workshop, Feb. 201

    Openness to Trade and Structural Changes in the Sources of Economic Growth and Labour Demand in Turkey

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    The Turkish economy has undergone drastic structural changes since 1980. While the effects of the Turkish adjustment programme have drawn considerable attention, a few studies have investigated its employment impacts. Unlike neoclassical expectation behind the structural adjustment programme, some studies for Turkey have showed that this policy change in 1980 caused a decline in employment. Results show that the Turkish industrialisation strategy cannot be regarded as export-led industrialisation strategy. Extra output created by exports has been very limited during the post-liberalisation period. However domestic final demand has continued to be the most dominant determinant of output growth. A Surprising result of the paper appears for the period of 1985-1990 when import substitution in final demand created output growth particularly in technology-intensive manufacturing and other manufacturing sectors. However import penetration in final and intermediate goods overwhelmingly important factors creating de-industrialisation in the period of 1990-1996. This paper, however, examines the sources of changes in employment. Despite neoclassical expectations, the reform period after 1982 witnessed large factor substitution against labour, even in the tradable goods sector. Additionally, labour demand also appears to response to output growth less in the post-liberalisation period than before.Structural changes, employment, input-output, trade reform, Turkey

    Source-Channel Coding under Energy, Delay and Buffer Constraints

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    Source-channel coding for an energy limited wireless sensor node is investigated. The sensor node observes independent Gaussian source samples with variances changing over time slots and transmits to a destination over a flat fading channel. The fading is constant during each time slot. The compressed samples are stored in a finite size data buffer and need to be delivered in at most dd time slots. The objective is to design optimal transmission policies, namely, optimal power and distortion allocation, over the time slots such that the average distortion at destination is minimized. In particular, optimal transmission policies with various energy constraints are studied. First, a battery operated system in which sensor node has a finite amount of energy at the beginning of transmission is investigated. Then, the impact of energy harvesting, energy cost of processing and sampling are considered. For each energy constraint, a convex optimization problem is formulated, and the properties of optimal transmission policies are identified. For the strict delay case, d=1d=1, 2D2D waterfilling interpretation is provided. Numerical results are presented to illustrate the structure of the optimal transmission policy, to analyze the effect of delay constraints, data buffer size, energy harvesting, processing and sampling costs.Comment: 30 pages, 15 figures. Submitted to IEEE Transactions on Wireless Communication

    Energy Harvesting Broadband Communication Systems with Processing Energy Cost

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    Communication over a broadband fading channel powered by an energy harvesting transmitter is studied. Assuming non-causal knowledge of energy/data arrivals and channel gains, optimal transmission schemes are identified by taking into account the energy cost of the processing circuitry as well as the transmission energy. A constant processing cost for each active sub-channel is assumed. Three different system objectives are considered: i) throughput maximization, in which the total amount of transmitted data by a deadline is maximized for a backlogged transmitter with a finite capacity battery; ii) energy maximization, in which the remaining energy in an infinite capacity battery by a deadline is maximized such that all the arriving data packets are delivered; iii) transmission completion time minimization, in which the delivery time of all the arriving data packets is minimized assuming infinite size battery. For each objective, a convex optimization problem is formulated, the properties of the optimal transmission policies are identified, and an algorithm which computes an optimal transmission policy is proposed. Finally, based on the insights gained from the offline optimizations, low-complexity online algorithms performing close to the optimal dynamic programming solution for the throughput and energy maximization problems are developed under the assumption that the energy/data arrivals and channel states are known causally at the transmitter.Comment: published in IEEE Transactions on Wireless Communication

    Distributions of PCNA and Cas-3 in rat uterus during early pregnancy.

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    The aim of present study was to determine the distributions of proliferating cell nuclear agent (PCNA) and Cas-pase-3 (Cas-3) and their possible roles in implantation and decidualization during early pregnancy at immunohistochemical level. The tissue samples from pregnant animals between gestational days 1-5 were incubated by PCNA and Cas-3 antibodies and the obtained results were evaluated quantitatively. It was observed that PCNA immunoreactivity in uterine luminal epithelium and glandular epithelium reduced as from day 2 of gestation and disappeared as from day 4 of gestation. PCNA staining intensity in stromal cells and myometrium increased gradually with progressing gestation. While Cas-3 immunoreactivity was strongly detected in luminal and glandular epithelium throughout the whole gestational period, its reactivity markedly increased as from day 3 of gestation. In conclusion, it may suggest that the blastocyst implantation induces the uterine luminal epithelial cell death and stromal cell proliferation around the embryo in the uterus
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