Scalable and Low Power LDPC Decoder Design Using High Level Algorithmic Synthesis

This paper presents a scalable and low power low-density parity-check (LDPC) decoder design for the next generation wireless handset SoC. The methodology is based on high level synthesis: PICO (program-in chip-out) tool was used to produce efficient RTL directly from a sequential untimed C algorithm. We propose two parallel LDPC decoder architectures: (1) per-layer decoding architecture with scalable parallelism, and (2) multi-layer pipelined decoding architecture to achieve higher throughput. Based on the PICO technology, we have implemented a two-layer pipelined decoder on a TSMC 65nm 0.9V 8-metal layer CMOS technology with a core area of 1.2 mm2. The maximum achievable throughput is 415 Mbps when operating at 400 MHz clock frequency and the estimated peak power consumption is 180 mW.NokiaNokia Siemens Networks (NSN)XilinxNational Science Foundatio

Chemistry of chlorinated species in the Antarctic stratosphere

The chemistry of Cl sub 2 O sub 2, the chlorine monoxide dimer, has been further investigated in order to better asses its potential role in catalytic ozone destruction cycles. The dimer has been generated in a flow system, in the 200 to 250 K temperature range, by using ozone and chlorine atoms as ClO precursors. The Cl-atoms are produced by a microwave discharge of either Cl sub 2, or of F sub 2 with subsequent addition of HCl. With this later scheme the dimer can be generated in the absence of Cl sub 2. The Fourier transform infrared spectra of the products clearly indicates the presence of two isomers, in agreement with earlier results (J. Phys. Shen., 91, 433, 1987). None of the observed IR bands can be attributed to a ClO-OClO adduct, since they all appear in the absence of any detectable amount of OCl. It is likely that the particles in the polar stratospheric clouds will have a relatively dilute nitric acid outer layer, even if the core is the nitric acid monohydrate, since the particles are in equilibrium with the ambient water vapor, which is present at levels of a few parts per million

Collecting villagers perspectives in the Mekong Delta

The Mekong Delta is a highly productive agricultural area and is vital to global food security, the Vietnamese economy and for sustaining the livelihoods of its 18 million residents. While the production of rice dominates agriculture in the Delta as a whole, some areas within it are well known for unique food products such as the fish coming from the flooded areas, the fruit from the middle alluvial area and the shrimps from the coast. The whole area, however, has changed drastically in the past twenty years. The project called “River food systems from villagers’ perspectives in the Mekong Delta”, implemented by WARECOD, a Vietnamese NGO and its partners, ran between 2015 and 2016. The team gathered local knowledge and conducted scientific research, looking in detail at the impact of the irrigation systems built since 2000 and at the changes they have brought

Abnormal Photoluminescence of TiO2_{2} nanocrystals (nanoparticles and nanotube arrays)

In this paper we report new abnormal photoluminescence results of TiO$_{2}$ nanocrystal particles and nanotube arrays. Photoluminescence spectra were recorded for TiO$_{2}$ nanocrystal particles and nanotube arrays that were synthesized by a wet chemical route and the electrochemical anodization, respectively. It was found that the TiO$_{2}$ nanocrystal with small size of 5-8 nm no emitted when excited by a laser beam of 325 nm, in contrary it emitted when excited by laser beam of 442 nm. The TiO$_{2}$ nanotube arrays exhibit a similar emission behavior. The nanotube arrays weakly emitted when excited by a laser beam of 325 nm and more strongly emitted when excited by a laser beam of 442 nm. The obtained results have been explained by a two-step exciting model and supposed to be related with the size effect of nanocrystal and it is an experimental evidence to believe that the TiO$_{2}$ nanoparticles and nanotube arrays are applicable for photo-catalysis under sun light

FPGA-Based Channel Coding Architectures for 5G Wireless Using High-Level Synthesis

We propose strategies to achieve a high-throughput FPGA architecture for quasi-cyclic low-density parity-check codes based on circulant-1 identity matrix construction. By splitting the node processing operation in the min-sum approximation algorithm, we achieve pipelining in the layered decoding schedule without utilizing additional hardware resources. High-level synthesis compilation is used to design and develop the architecture on the FPGA hardware platform. To validate this architecture, an IEEE 802.11n compliant 608 Mb/s decoder is implemented on the Xilinx Kintex-7 FPGA using the LabVIEW FPGA Compiler in the LabVIEW Communication System Design Suite. Architecture scalability was leveraged to accomplish a 2.48 Gb/s decoder on a single Xilinx Kintex-7 FPGA. Further, we present rapidly prototyped experimentation of an IEEE 802.16 compliant hybrid automatic repeat request system based on the efficient decoder architecture developed. In spite of the mixed nature of data processing—digital signal processing and finite-state machines—LabVIEW FPGA Compiler significantly reduced time to explore the system parameter space and to optimize in terms of error performance and resource utilization. A 4x improvement in the system throughput, relative to a CPU-based implementation, was achieved to measure the error-rate performance of the system over large, realistic data sets using accelerated, in-hardware simulation

High-Level Design Tools for Complex DSP Applications

High-level synthesis design methodology - High level synthesis (HLS) [1], also known as behavioral synthesis and algorithmic synthesis, is a design process in which a high level, functional description of a design is automatically compiled into a RTL implementation that meets certain user specified design constraints. The HLS design description is ‘high level’ compared to RTL in two aspects: design abstraction, and specification language

Infection with hepatitis B virus carrying novel pre-S/S gene mutations in female siblings vaccinated at birth: two case reports

<p>Abstract</p> <p>Introduction</p> <p>After the initiation of a mass hepatitis B vaccination program in Taiwan, the prevalence of hepatitis B virus infection has declined progressively. However, about 1 percent of the young generation, who received hepatitis B vaccination at birth, remain carriers. Infection with vaccine-escape hepatitis B virus mutants always occurs shortly after birth. Here, we report two female siblings in whom the infection occurred in their adolescence. This report raises the question of whether a booster for hepatitis B vaccination is needed.</p> <p>Case presentation</p> <p>Two 19 and 14-year-old Taiwanese female siblings were born to a mother infected with hepatitis B virus and received a complete course of hepatitis B vaccination at birth. They remained negative for serum hepatitis B surface antigen and positive for serum anti-hepatitis B surface antibody throughout their childhood. However, both were infected with the hepatitis B virus in their adolescence. Hepatitis B virus DNA was extracted from serum samples from the mother and two siblings. Hepatitis B virus pre-S/S sequence was amplified by polymerase chain reaction followed by nucleotide sequencing. When compared with the sequence obtained from the mother, multiple amino acid substitutions located near or in the major hydrophilic region of the surface antigen were identified in the elder sister. Four of these mutations (sL97S, sL98S, sG102R, and sA159P) were novel. A novel in-frame deletion (14 amino acids deleted, pre-S 127-140) was found in the hepatitis B virus pre-S2 region in the younger sister.</p> <p>Conclusions</p> <p>Despite having received hepatitis B vaccination at birth, hepatitis B virus infection can still occur in adolescence with the emergence of novel mutations in the pre-S/S gene. This is a rare event and, to the best of our knowledge, has not been previously reported.</p

Women's preference for cesarean delivery and differences between Taiwanese women undergoing different modes of delivery

<p>Abstract</p> <p>Background</p> <p>The rate of cesarean delivery was 35% in 2007 in Taiwan. It is unclear how many of the cesarean deliveries were without medical indications. Women's preference for cesarean delivery during their course of pregnancy has rarely been studied and therefore our objectives were to examine rate of cesarean deliveries without medical indications, to explore women's preference for cesarean delivery as their gestation advances, and to compare background and perinatal factors among women who underwent different modes of delivery in Taiwan.</p> <p>Methods</p> <p>This prospective study applied a longitudinal design. The study participants were 473 women who received prenatal care at four hospitals in Taipei and answered structured questionnaires at 20 to 24 weeks of pregnancy, 34 to 36 weeks of pregnancy, and 5 to 7 weeks after delivery.</p> <p>Results</p> <p>Of the 151 women (31.9%) who had cesarean deliveries, 19.9% were without medical indication. Three indications: malpresentation, prior cesarean section, and dysfunctional labor together accounted for 82.6% of cesarean section with medical indications. The prevalence of maternal preference for cesarean delivery was found to be 12.5% and 17.5% during the second and third trimester, respectively. Of the women who preferred cesarean delivery during the second trimester, 93.2% eventually had a cesarean delivery. Women who were older, with older spouses, and who had health problems before or during pregnancy were more likely to have cesarean deliveries.</p> <p>Conclusions</p> <p>About 20% of cesarean deliveries were without medical indications. Women's preference for cesarean delivery during the second trimester predicts subsequent cesarean delivery. Counseling regarding mode of delivery should be offered early in pregnancy, especially for women who are older or with older spouses, have health problems, or had a prior cesarean section.</p