778 research outputs found

    Architectural Support for High-Performance, Power-Efficient and Secure Multiprocessor Systems

    Get PDF
    High performance systems have been widely adopted in many fields and the demand for better performance is constantly increasing. And the need of powerful yet flexible systems is also increasing to meet varying application requirements from diverse domains. Also, power efficiency in high performance computing has been one of the major issues to be resolved. The power density of core components becomes significantly higher, and the fraction of power supply in total management cost is dominant. Providing dependability is also a main concern in large-scale systems since more hardware resources can be abused by attackers. Therefore, designing high-performance, power-efficient and secure systems is crucial to provide adequate performance as well as reliability to users. Adhering to using traditional design methodologies for large-scale computing systems has a limit to meet the demand under restricted resource budgets. Interconnecting a large number of uniprocessor chips to build parallel processing systems is not an efficient solution in terms of performance and power. Chip multiprocessor (CMP) integrates multiple processing cores and caches on a chip and is thought of as a good alternative to previous design trends. In this dissertation, we deal with various design issues of high performance multiprocessor systems based on CMP to achieve both performance and power efficiency while maintaining security. First, we propose a fast and secure off-chip interconnects through minimizing network overheads and providing an efficient security mechanism. Second, we propose architectural support for fast and efficient memory protection in CMP systems, making the best use of the characteristics in CMP environments and multi-threaded workloads. Third, we propose a new router design for network-on-chip (NoC) based on a new memory technique. We introduce hybrid input buffers that use both SRAM and STT-MRAM for better performance as well as power efficiency. Simulation results show that the proposed schemes improve the performance of off-chip networks through reducing the message size by 54% on average. Also, the schemes diminish the overheads of bounds checking operations, thus enhancing the overall performance by 11% on average. Adopting hybrid buffers in NoC routers contributes to increasing the network throughput up to 21%

    Architectural Support for High-Performance, Power-Efficient and Secure Multiprocessor Systems

    Get PDF
    High performance systems have been widely adopted in many fields and the demand for better performance is constantly increasing. And the need of powerful yet flexible systems is also increasing to meet varying application requirements from diverse domains. Also, power efficiency in high performance computing has been one of the major issues to be resolved. The power density of core components becomes significantly higher, and the fraction of power supply in total management cost is dominant. Providing dependability is also a main concern in large-scale systems since more hardware resources can be abused by attackers. Therefore, designing high-performance, power-efficient and secure systems is crucial to provide adequate performance as well as reliability to users. Adhering to using traditional design methodologies for large-scale computing systems has a limit to meet the demand under restricted resource budgets. Interconnecting a large number of uniprocessor chips to build parallel processing systems is not an efficient solution in terms of performance and power. Chip multiprocessor (CMP) integrates multiple processing cores and caches on a chip and is thought of as a good alternative to previous design trends. In this dissertation, we deal with various design issues of high performance multiprocessor systems based on CMP to achieve both performance and power efficiency while maintaining security. First, we propose a fast and secure off-chip interconnects through minimizing network overheads and providing an efficient security mechanism. Second, we propose architectural support for fast and efficient memory protection in CMP systems, making the best use of the characteristics in CMP environments and multi-threaded workloads. Third, we propose a new router design for network-on-chip (NoC) based on a new memory technique. We introduce hybrid input buffers that use both SRAM and STT-MRAM for better performance as well as power efficiency. Simulation results show that the proposed schemes improve the performance of off-chip networks through reducing the message size by 54% on average. Also, the schemes diminish the overheads of bounds checking operations, thus enhancing the overall performance by 11% on average. Adopting hybrid buffers in NoC routers contributes to increasing the network throughput up to 21%

    Generation of both cortical and Aire(+) medullary thymic epithelial compartments from CD205(+) progenitors

    Get PDF
    In the adult thymus, the development of self-tolerant thymocytes requires interactions with thymic epithelial cells (TECs). Although both cortical and medullary TECs (cTECs/mTECs) are known to arise from common bipotent TEC progenitors, the phenotype of these progenitors and the timing of the emergence of these distinct lineages remain unclear. Here, we have investigated the phenotype and developmental properties of bipotent TEC progenitors during cTEC/mTEC lineage development. We show that TEC progenitors can undergo a stepwise acquisition of first cTEC and then mTEC hallmarks, resulting in the emergence of a progenitor population simultaneously expressing the cTEC marker CD205 and the mTEC regulator Receptor Activator of NF-κB (RANK). In vivo analysis reveals the capacity of CD205(+) TECs to generate functionally competent cortical and medullary microenvironments containing both cTECs and Aire(+) mTECs. Thus, TEC development involves a stage in which bipotent progenitors can co-express hallmarks of the cTEC and mTEC lineages through sequential acquisition, arguing against a simple binary model in which both lineages diverge simultaneously from bipotent lineage negative TEC progenitors. Rather, our data reveal an unexpected overlap in the phenotypic properties of these bipotent TECs with their lineage-restricted counterparts

    Prevalence of sarcopenia and sarcopenic obesity in Korean adults: The Korean Sarcopenic Obesity Study (KSOS)

    Get PDF
    *Context:* Sarcopenic obesity (SO), a combination of excess weight and reduced muscle mass and/or strength, is suggested to be associated with an increased risk of adverse health outcomes. 
*Objectives:* To examine the prevalence and characteristics of Sarcopenic and SO defined by using different indices such as Appendicular Skeletal muscle Mass (ASM)/height^2^ and Skeletal Muscle Index (SMI (%): skeletal muscle mass (kg)/weight (kg) × 100) for Korean adults. 
*Methods:* 591 participants were recruited from the Korean Sarcopenic Obesity Study (KSOS) which is an ongoing prospective observational cohort study. Analysis was conducted in 526 participants (328 women, 198 men) who had complete data on body composition using Dual X-ray absorptiometry and computed tomography. 
*Results:* The prevalence of sarcopenia and SO increases with aging. Using two or more standard deviations (SD) of ASM/height^2^ below reference values from young, healthy adults as a definition of sarcopenia, the prevalence of sarcopenia and SO was 6.3% and 1.3% in men and 4.1% and 1.7% in women over 60 years of age. However, using two or more SD of SMI, the prevalence of sarcopenia and SO was 5.1% and 5.1% respectively in men and 14.2% and 12.5% respectively in women. As defined by SMI, subjects with SO had 3 times the risk of metabolic syndrome (OR = 3.03, 95% confidence interval (CI) = 1.26-7.26) and subjects with non-sarcopenic obesity had approximately 2 times the risk of metabolic syndrome (OR = 1.89, 95% CI = 1.18-3.02) compared with normal subjects. 
*Conclusion:* Obese subjects with relative sarcopenia were associated with a greater likelihood for metabolic syndrome. As Koreans were more obese and aging, the prevalence of SO and its impact on health outcomes are estimated to be rapidly grow. Further research is requested to establish the definition, cause and consequences of SO.
&#xa

    Interactions between the FTO rs9939609 polymorphism, body mass index, and lifestyle-related factors on metabolic syndrome risk

    Get PDF
    Whether the FTO polymorphisms interact with environmental factors has not yet been evaluated in associations with metabolic syndrome (MS) risk. The present study investigated the association of the FTO rs9939609 genotypes, body mass index (BMI), and lifestyle-related factors including smoking, alcohol drinking, physical activity, and diet with MS incidence. A population-based prospective cohort study comprised 3,504 male and female Koreans aged 40 to 69 years. At the beginning of the study, all individuals were free of MS and known cardiovascular disease. Incident cases of MS were identified by biennial health examinations during a follow-up period from April 17, 2003 to April 15, 2009. Pooled logistic regression analysis was applied to obtain relative odds (RO) of MS with its 95% confidence interval (CI). After controlling for potential MS risk factors, we observed no association between the rs9939609 genotypes and MS incidence. In analysis stratified by BMI, however, carriers with the FTO risk allele whose BMI is 29 kg/m2 or greater showed an approximately 6-fold higher RO (95% CI: 3.82 to 9.30) compared with non-carriers with BMI less than 25 kg/m2. In particular, the association between the rs9939609 variants and MS risk was significantly modified by high BMI (P-value for interaction < 0.05). Such significant interaction appeared in associations with central obesity and high blood pressure among the MS components. Because carriers of the FTO risk alleles who had BMI of 29 kg/m2 or greater are considered a high risk population, we suggest that they may need intensive weight loss regimens to prevent MS development

    Solution-processed ZnO as the efficient passivation and electron selective layer of silicon solar cells

    Full text link
    Solution-processed intrinsic ZnO and Al doped ZnO (ZnO:Al) were spin coated on textured n-type c-Si wafer to replace the phosphorus doped amorphous silicon as the electron selective transport layer (ESTL) of the Si heterojunction (SHJ) solar cells. Besides the function of electron selective transportation, the non-doped ZnO was found to possess certain passivation effect on c-Si wafer. The SHJ solar cells with different combinations of passivation layer (intrinsic a-Si:H, SiOx and non-doped ZnO) and electron transport layer (non-doped ZnO and ZnO:Al ) were fabricated and compared. An efficiency up to 18.46% was achieved on a SHJ solar cell with an a-Si:H/ZnO:Al double layer back structure. And, the all solution-processed non-doped ZnO/ZnO:Al combination layer presents fairly good electron selective transportation property for SHJ solar cell, resulting in an efficiency of 17.13%. The carrier transport based on energy band diagrams of the rear side of the solar cells has been discussed related to the performance of the SHJ solar cells.Comment: 12 pages, 4 figures, 1 tabl

    Impact of visceral fat on skeletal muscle mass and vice versa in a prospective cohort study: The Korean Sarcopenic Obesity Study (KSOS)

    Get PDF
    Objectives: Sarcopenia and visceral obesity have been suggested to aggravate each other, resulting in a vicious cycle. However, evidence based on prospective study is very limited. Our purpose was to investigate whether visceral fat promotes a decrease in skeletal muscle mass and vice versa. Methods: We observed changes in anthropometric and body composition data during a follow-up period of 27.6±2.8 months in 379 Korean men and women (mean age 51.9±14.6 years) from the Korean Sarcopenic Obesity Study (KSOS). Appendicular lean soft tissue (ALST) mass was calculated using dual-energy X-ray absorptiometry, and visceral fat area (VFA) was measured using computed tomography at baseline and follow-up examination. Results: ALST mass significantly decreased, whereas trunk and total fat mass increased in both men and women despite no significant change in weight and body mass index. In particular, women with visceral obesity at baseline had a greater decrease in ALST mass than those without visceral obesity (P=0.001). In multiple linear regression analysis, baseline VFA was an independent negative predictor of the changes in ALST after adjusting for confounding factors including age, gender, life style and body composition parameters, insulin resistance, high sensitivity C-reactive protein and vitamin D levels (P=0.001), whereas the association between baseline ALST mass and changes in VFA was not statistically significant (P=0.555). Conclusions: This longitudinal study showed that visceral obesity was associated with future loss of skeletal muscle mass in Korean adults. These results may provide novel insight into sarcopenic obesity in an aging society

    Genomic alterations of primary tumor and blood in invasive ductal carcinoma of breast

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Genomic alterations are important events in the origin and progression of various cancers, with DNA copy number changes associated with progression and treatment response in cancer. Array CGH is potentially useful in the identification of genomic alterations from primary tumor and blood in breast cancer patients. The aim of our study was to compare differences of DNA copy number changes in blood and tumor tissue in breast cancer.</p> <p>Methods</p> <p>DNA copy number changes in blood were compared to those in tumor tissue using array-comparative genomic hybridization in samples obtained from 30 breast cancer patients. The relative degree of chromosomal changes was analyzed using log2 ratios and data was validated by real-time polymerase chain reaction.</p> <p>Results</p> <p>Forty-six regions of gains present in more than 30% of the tissues and 70 regions of gains present in more than 30% of blood were identified. The most frequently gained region was chromosome 8q24. In total, agreement of DNA copy numbers between primary tumor and blood was minimal (Kappa = 0.138, p < 0.001).</p> <p>Conclusion</p> <p>Although there was only a slight agreement of DNA copy number alterations between the primary tumor and the blood samples, the blood cell copy number variation may have some clinical significance as compared to the primary tumor in IDC breast cancer patients.</p
    corecore