Memory energy minimization by data compression: algorithms, architectures and implementation

Storing data in compressed form is becoming common practice in high-performance systems, where memory bandwidth constitutes a serious bottleneck to program execution speed. In this paper, we suggest hardware-assisted data compression as a tool for reducing energy consumption of processor-based systems. We propose a novel and efficient architecture for on-the-fly data compression and decompression whose field of operation is the cache-to-memory path. Uncompressed cache lines are compressed before they are written back to main memory, and decompressed when cache refills take place. We explore two classes of table-based compression schemes. The first, based on offline data profiling, is particularly suitable to embedded systems, where predictability of the data set is usually higher than in general-purpose systems. The second solution we introduce is adaptive, that is, it takes decisions on whether data words should be compressed according to the data statistics of the program being executed. We describe in details the architecture of the compression/decompression unit and we provide an insight about its implementation as a hardware (HW) block. We present experimental results concerning memory traffic and energy consumption in the cache-to-memory path of a core-based system running standard benchmark programs. The obtained energy savings range from 8%-39% when profile-driven compression is adopted, and from 7%-26% when the adaptive scheme is used. Performance improvements are also achieved as a by-product, showing the practical applicability of the proposed approach.     

5-Fluorouracil plus interferon alpha-2a compared to 5-fluorouracil alone in the treatment of advanced colon carcinoma: a multicentric randomized study

Biochemical modulation is one of the most interesting fields in cancer chemotherapy. Interferon-alpha (IFNalpha) is a cytokine that is able to influence the pharmacodynamics of 5-fluorouracil (5FU) through a number of mechanisms. With the aim of confirming some data emerging from the literature, we initiated a multicentric randomized study comparing the combination of 5FU and IFNalpha-2a with 5FU alone in the treatment of advanced or metastatic colon cancer. A group of 205 colon cancer patients (104 in the 5FU arm and 101 in the 5FU + IFNapha-2a arm) were included in the final intention-to-treat analysis. Rectal cancers were not considered eligible. All patients had measurable disease, were aged 75 years or less, had a Karnofsky index of at least 60 and had good bone marrow, renal, liver and cardiac functions. No previous chemo-immunotherapy was allowed. The treatment was 750 mg/m2 5FU (4 h i.v. infusion) on days 1 5 and then i.v. bolus weekly, starting from day 12, with or without IFNalpha-2a given s.c. three times weekly (starting dose 3 x 10(6) IU rising to 9 x 10(6) IU, if tolerated). Patients were treated until progression or, if responsive, for a maximum of 48 weeks and then observed for a period of 2 years. The primary end-point of the study was objective clinical response (OR); secondary parameters were time to progression, overall survival, and time to death after progression. WHO criteria were used for both clinical response and toxicity measurements. Dose reduction was planned a priori in the event of significant toxicity due to 5FU, IFNalpha-2a or both. Association between primary and secondary end-points and treatment was studied by univariate and multivariate analysis. Altogether, 47 patients achieved a documented response. A 25% OR was observed in the combination arm while a 21% OR was seen in the 5FU arm; this difference is not statistically significant (P = 0.6). Patients with a small tumour burden (below 5 cm2) showed a higher probability of response in both arms. Patients in the experimental arm had a higher but not statistically significant cumulative progression-free probability. Median survival was 47.1 weeks overall, while it was 43.7 and 48.5 weeks in the control and experimental arms, respectively. The combination was clearly more toxic than 5FU alone, leukopenia being the most frequent side-effect in the experimental arm and nausea and vomiting in the control arm. In conclusion these results are quite disappointing and 5FU + IFNalpha-2a can not be considered a standard treatment for advanced colon cancer.     

A Framework for Modeling and Estimating the Energy Dissipation of VLIW-Based Embedded Systems

This paper describes a technique for modeling and estimating the power consumptionat the system-level for embedded VLIW (Very Long Instruction Word) architectures.The method is based on a hierarchy of dynamic power estimationengines: from the instruction-level down to the gate/transistor-level. Powermacro-models have been developed for the main components of the system: theVLIW core, the register file, the instruction and data caches. The main goalis to define a system-level simulation framework for the dynamic profilingof the power behavior during the software execution, providing also a break-downof the power contributions due to the single components of the system. Theproposed approach has been applied to the Lx family of scalable embedded VLIWprocessors, jointly designed by STMicroelectronics and HPLabs. Experimentalresults, carried out over a set of benchmarks for embedded multimedia applications,have demonstrated an average accuracy of 5% of the instruction-level estimationengine with respect to the RTL engine, with an average speed-up of four ordersof magnitude.     

Effects of bicyclomycin on RNA- and ATP-binding activities of transcription termination factor Rho

Physicians who serve the pediatric population are the first line in identification and management of photosensitivity disorders present in childhood. The role of the dermatologist is not only to identify and treat these disorders, but also to counsel patients and their families in specific light avoidance, photoprotection, and in some cases, major lifestyle adjusts. This article reviews photosensitivity disorders, treatment, and prevention.     

Solid state synthesis of stoichiometric LiCoO2 from mechanically activated Co–Li2CO3 mixtures

Stoichiometric lithium cobalt oxide (LiCoO₂) has been synthesized by solid state reaction of mixtures of the system Co–0.5Li₂CO₃ after mechanical activation by high energy milling. The differences in the reaction mechanism and in product stoichiometry with respect to what happens when starting from the non activated (physical) system have been brought into evidence by TG analysis. Furthermore it has been shown that stoichiometric LiCoO₂ is obtained by a 200 h annealing of the activated mixture at temperatures as low as 400 °C. Finally, it has been revealed that longer activation times (150 h) result in Co oxidation to Co₃O₄ that, in turn, hampers the formation of stoichiometric LiCoO₂.     

Time-Scale Atoms Chains for Transients Detection in Audio Signals

This paper presents a novel approach for the extraction of the transients content of audio signals, usually represented as superposition of stationary, transient, and stochastic components. The proposed model exploits the predictable and peculiar time-scale behavior of transients by modeling them as superposition of suitable wavelet atoms. These latter allow to predict transients information even at scales where the tonal component is dominant. In this way it is possible to avoid, if required, the pre-analysis of the tonal component. Extensive experimental results show that the proposed model achieves good performances with a moderate computational effort and without any user's dependence.      

Apoptosis as Driver of Therapy-Induced Cancer Repopulation and Acquired Cell-Resistance (CRAC): A Simple In Vitro Model of Phoenix Rising in Prostate Cancer

Apoptotic cells stimulate compensatory proliferation through the caspase-3-cPLA-2-COX-2-PGE-2-STAT3 Phoenix Rising pathway as a healing process in normal tissues. Phoenix Rising is however usurped in cancer, potentially nullifying pro-apoptotic therapies. Cytotoxic therapies also promote cancer cell plasticity through epigenetic reprogramming, leading to epithelial-to-mesenchymal-transition (EMT), chemo-resistance and tumor progression. We explored the relationship between such scenarios, setting-up an innovative, straightforward one-pot in vitro model of therapy-induced prostate cancer repopulation. Cancer (castration-resistant PC3 and androgen-sensitive LNCaP), or normal (RWPE-1) prostate cells, are treated with etoposide and left recovering for 18 days. After a robust apoptotic phase, PC3 setup a coordinate tissue-like response, repopulating and acquiring EMT and chemo-resistance; repopulation occurs via Phoenix Rising, being dependent on high PGE-2 levels achieved through caspase-3-promoted signaling; epigenetic inhibitors interrupt Phoenix Rising after PGE-2, preventing repopulation. Instead, RWPE-1 repopulate via Phoenix Rising without reprogramming, EMT or chemo-resistance, indicating that only cancer cells require reprogramming to complete Phoenix Rising. Intriguingly, LNCaP stop Phoenix-Rising after PGE-2, failing repopulating, suggesting that the propensity to engage/complete Phoenix Rising may influence the outcome of pro-apoptotic therapies. Concluding, we established a reliable system where to study prostate cancer repopulation, showing that epigenetic reprogramming assists Phoenix Rising to promote post-therapy cancer repopulation and acquired cell-resistance (CRAC).     

Efficient analysis of in‐line waveguide filters and frequency‐selective surfaces with stepped holes

This paper presents a novel method for the analysis of large classes of microwave and mm‐wave passive components, including in‐line waveguide filters, single‐ and multi‐layer frequency selective surfaces, and open‐ended waveguide array antennas. This method is based on the segmentation technique, which permits us to reduce complex components to cascaded waveguide step discontinuities, which are separately characterized through their generalized impedance matrices, as calculated by the integral equation (IE) technique and the boundary integral‐resonant mode expansion (BI‐RME) method. Some examples demonstrate the flexibility and efficiency of the IE/BI‐RME method, and its utility in investigating novel structures not requiring costly fabrication techniques. © 2003 Wiley Periodicals, Inc. Int J RF and Microwave CAE 13: 306–315, 2003.     

Evaluating project completion time in project networks with discrete random activity durations

Deterministic models for project scheduling suffer from the fact that they assume complete information and neglect random influences, that occur during project execution. A typical consequence is the underestimation of the project duration as frequently observed in practice. This phenomenon occurs even in the absence of resource constraints and has been the subject of extensive research in the scientific community. This paper presents a method for obtaining relevant information about the project makespan for scheduling models, with dependent random processing time available in the form of scenarios.