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For synchronous downlink direct-sequence code-division multiple access (DS-CDMA), we introduce a cyclic-prefix (CP)-based convolutional spreading CDMA (CS-CDMA/CP) scheme employing zero correlation zone (ZCZ) codes, which gives a class of multiuser interference (MUI)-free CDMA schemes, including Suehiro's CDMA and block spreading (BS) CDMA as special cases. We show that CS-CDMA/CP employing appropriately selected binary and ternary ZCZ codes have good user capacity, peak-to-average power ratio (PAPR), and transmission power loss, compared with previously proposed BS-CDMA schemes. By simulation, we show the effect of PAPR to its bit-error rate (BER) performance when nonlinear amplifiers are used, and also compare its BER performance with the conventional DS-CDMA scheme employing a RAKE receiver

Background DNA is fragmented and released into blood circulation as results of damage or death of cells from peripheral bloods as well as organ tissues, and circulating cell-free DNA (ccfDNA) has been recognized as biomarkers of several medical conditions [1]. In patients with rheumatoid arthritis (RA), serum concentration of ccfDNA has been reported to be elevated [2], however, the relation between ccfDNA and the pathogenesis of RA remains unclear. Objectives To evaluate the correlation between ccfDNA in plasma and clinical disease activities in patients with RA. Methods The study group included 29 patients with RA who started biological DMARDs therapy. The concentration of ccfDNA in plasma was measured by quantitative real-time PCR at baseline to 24 weeks in every 4 weeks-period from 29 patients, and 21 healthy individuals. We also evaluated the correlation between ccfDNA and the clinical activities or the response for biological DMARDs, using disease activity score of 28 joints erythrocyte sedimentation rate (DAS28ESR) and the european league against rheumatism (EULAR) response criteria. In addition, synovial fluid samples of knee joint were collected from 14 patients with RA and12 with osteoarthritis (OA) to measure ccfDNA Results The concentration of ccfDNA in RA patients at baseline was higher than healthy controls (p=0.016).When evaluated the concentration of ccfDNA, it was increased until 8 weeks-period from the baseline, and then decreased after 12weeks-period. The average of DAS28ESR was improved in all patients enrolled. At 12weeks-period after treatment, 15 patients were good responders of the EULAR response criteria, 9 showed the moderate response and 5 showed no response. The concentration of ccfDNA in good responder was increased until 8weeks while those of moderate or no responder were not (P=0.042) (figure), and there was no significant difference between ccfDNA at baseline and other parameters in all patients. In joint fluid of RA patients, the concentration of ccfDNA was remarkably increased as compared to those from OA (P=0.00011). Conclusions Increase of ccfDNA at 8 weeks-period was associated with improvement of disease activity. Compared with the biomarkers reported before, ccfDNA is possible to predict the early therapeutic effects of biological DMARDs in RA patients. References Jiajia Y, Guohao G, Shaoqing J. Recent Advances in Clinical Applications of Circulating Cell-free DNA Integrity. Lab medicine 2014;45:6–12 Zhong XY, Muhlenen IV, Li Y, Kang A, Gupta AK, Tyndall A, et al. Increased Concentrations of Antibody-Bound circulatory cell-free DNA in rheumatoid arthritis. Clin Chem 2007;53:1609–1614 Disclosure of Interest None declared

In synchronous DS-CDMA systems the multi-user interference (MUI) caused by multipath propagation degrades the system performance. To overcome this, MUI-free schemes, such as Suehiro's CDMA in N. Suehori (1994) and H.H. Chen et al. (2001) and CIBS-CDMA in S. Zhou et al. (2002) are introduced. In this paper a new class of cyclic prefix (CP) based convolutional spreading CDMA (CS-CDMA/CP) scheme employing zero correlation zone (ZCZ) codes [P.Z. Fan et al., May 1999] is proposed. We show that above two MUI-free schemes are special cases of CS-CDMA/CP and they only difference comes from the particular employed ZCZ code. A comparison in terms of PAPR and transmission power loss for the CS-CDMA schemes is given. We consider a pilot aided downlink CS-CDMA/CP employing equalizers, and compare its performance with the conventional DS-CDMA system employing RAKE receivers via simulation. Our simulation results show that, CS-CDMA/CP performs better than DS-CDMA when system has many users.

A complete analysis for the reconstruction noise due to the scalar quantization of a wavelet pyramid image coding system is given. It is shown that when the optimal bit allocation scheme is adopted, the reconstruction noises and the quantization noises of the wavelet pyramid system become regular, and that the reconstruction noises can be approximated to stationary white noises. Particularly, it is shown that with only one quantization mean-square-error (MSE) of the wavelet decomposition at any layer of the wavelet pyramid, all of the reconstruction MSEs and the quantization MSEs of the wavelet pyramid can be easily calculated. Simulations verify the theoretical results. >

As the space technologies are developed, satellite mission requires higher performance on attitude control or pointing control system. Among the requirements from the mission observation that for attitude or pointing stability, especially, is high as the order of sub-arcsecond. In the design phase, the quantitative evaluation on this stability is required to optimize the system design. In this paper, this evaluation methods for pointing performance is summarized. The clearly defined mathematical interface scheme is shown to describe the disturbance torque and force. The concept of the "index" to effectively evaluate the pointing performance is introduced. In the frame of this "index" concept, further the performance evaluation filter is introduced which enables to analyze the influence of disturbance in the frequency domain. The filter is useful to understand the dominant disturbance torque source in the frequency region.