Direct Optimization of a PCI Express Link Equalization in Industrial Post-Silicon Validation

Post-silicon validation is a crucial industrial testing process in modern computer platforms. Post-silicon validation of high-speed input/output (HSIO) links can be critical for making a product release qualification. Peripheral component interconnect express (PCIe) is a high-performance interconnect architecture widely adopted in the computer industry, and one of the most complex HSIO interfaces. PCIe data rates increase on every new generation. To mitigate channel effects due to the increase in transmission speeds, the PCIe specification defines requirements to perform equalization (EQ) at the transmitter (Tx) and at the receiver (Rx). During the EQ process, one combination of Tx/Rx EQ coefficients must be selected to meet the performance requirements of the system. Testing all possible coefficient combinations is prohibitive. Current industrial practice consists of finding a subset of combinations at post-silicon validation using maps of EQ coefficients, which are obtained by measuring the eye height, eye width, and the eye asymmetries of the received signal. Given the large number of electrical parameters and the multiplicity of signal eyes that are produced by on-die probes for observation, finding this subset of coefficients is often a challenge. In order to overcome this problem, a direct optimization method based on a suitable objective function formulation to efficiently tune the Tx and Rx EQ coefficients to successfully comply with the PCIe specification is presented in this report. The proposed optimization approach is based on a low-cost computational procedure combining pattern search and Nelder-Mead methods to efficiently solve an objective function with many local minima, and evaluated by lab measurements on a realistic industrial post-silicon validation platform

Effects of salinity and B excess on the growth, photosynthesis, water relation and mineral composition of laurustinus grown in greenhouse

Trabajo presentado en el XXVIII International Horticultural Congress on Science and Horticulture for People (IHC2010): International Symposium on Greenhouse 2010 and Soilless Cultivation, celebrado en Lisboa, Portugal, del 22 al 27 de agosto de 2010A greenhouse study was conducted to determine the interactive effects of NaCl salinity and boron on the growth, plant water status, gas exchange, chlorophyll fluorescence and concentrations of sodium (Na), chloride (Cl) and boron (B) in laurustinus (Viburnum tinus L.). Potted plants were grown in a factorial combination of salinity (2 and 6 dS m-1) and boron (1 and 6 mg L-1). Plant dry weight (DW) decreased with salinity and B excess, particularly as a result of the former. The salinity × B interaction on the plant DW was not significant (additive effects). Salinity increased Na and Cl concentrations in leaf (20 and 35 mg g-1 DW, respectively) resulting in foliar injury. The application of 6 mg L-1 of B (B toxicity or B excess) produced injury symptoms in old leaves (leaf tip and edge burn). Salinity and B toxicity led to leaves dropping, especially the former. B toxicity led to higher B concentrations in insured leaves (1385 mg kg-1 DW) and salinity reduced it to 425 (B x NaCl antagonistic effect). Boron excess did no alter Na and Cl concentrations in leaf. Salinity decreased stomatal conductance (gs) as a regulatory mechanism against osmotic stress, which resulted in a dropping photosynthesis (Pn). Leaf water parameters were only affected by salinity, which enhanced a process of osmotic adjustment and improving the plant water status. Salt-stressed plants showed an adaptive response to salinity, which decreased gs, Pn and quantum yield of photosystem II (éPSII), and dissipated the excess radiant energy as heat (increased non-photochemical quenching [NPQ]). The combination of salinity and B excess maintained éPSII and decreased the effectiveness of stomatal regulation, NPQ and Pn. This caused the lowest plant DW and suggests disorders in electron transport (photorespiration). Our findings suggest that: (1) laurustinus is a B excess sensitive species, (2) salinity reduced the accumulation of B in leaves of the B excess stressed plants but was not enough to prevent injuries in PSII, and (3) B excess or/and salinity provide plants of poor commercial quality.This research was supported by CICYT projects (CICYT AGL2008-05258-CO2- 1-AGR and CICYT AGL2008-05258-CO2-2-AGR), SENECA project (08669/PI/08) and by the Consejería de Agricultura y Agua de la Región de Murcia, program (UPCTCEBAS- IMIDA 2008).Peer Reviewe

High-Speed Links Receiver Optimization in Post-Silicon Validation Exploiting Broyden-based Input Space Mapping

One of the major challenges in high-speed input/output (HSIO) links electrical validation is the physical layer (PHY) tuning process. Equalization techniques are employed to cancel any undesired effect. Typical industrial practices require massive lab measurements, making the equalization process very time consuming. In this paper, we exploit the Broyden-based input space mapping (SM) algorithm to efficiently optimize the PHY tuning receiver (Rx) equalizer settings for a SATA Gen 3 channel topology. We use a good-enough surrogate model as the coarse model, and an industrial post-silicon validation physical platform as the fine model. A map between the coarse and the fine model Rx equalizer settings is implicitly built, yielding an accelerated SM-based optimization of the PHY tuning process

The Poor Survival among Pulmonary Tuberculosis Patients in Chiapas, Mexico: The Case of Los Altos Region

Objective. To analyse survival in patients with pulmonary tuberculosis (PTB) and factors associated with such survival. Design. Study of a cohort of patients aged over 14 years diagnosed with PTB from January 1, 1998 to July 31, 2005. During 2004–2006 a home visit was made to each patient and, during 2008-2009, they were visited again. During these visits a follow-up interview was administered; when the patient had died, a verbal autopsy was conducted with family members. Statistical analysis consisted of survival tests, Kaplan-Meier log-rank test and Cox regression. Results. Of 305 studied patients, 68 had died due to PTB by the time of the first evaluation, 237 were followed-up for a second evaluation, and 10 of them had died of PTB. According to the Cox regression, age (over 45 years) and treatment duration (under six months) were associated with a poorer survival. When treatment duration was excluded, the association between poorer survival with age persisted, whereas with having been treated via DOTS strategy, was barely significant. Conclusions. In the studied area it is necessary that patients receive a complete treatment scheme, and to give priority to patients aged over 45 years

Synthesis and Antioxidant Evaluation of Enantiomerically Pure Bis-(1,2,3-triazolylmethyl)amino Esters from Modified α

The efforts for synthesis of enantiomerically pure bis-(1,2,3-triazolylmethyl)amino esters 6 are reported in good yields from an in situ generated α-azidomethyl ketone. Optimum experimental conditions were established for preparation of α-halomethyl ketones 10 and α-N,N-dipropargylamino esters 11, all derived from α-amino acids. The starting materials reacted under conventional click chemistry conditions, revealing a specific reactivity of bromomethyl ketones over chloromethyl ketones. The antioxidant activity of compounds 6 was assayed by DPPH method. The compound 6c with an IC50 of 75.57 ± 1.74 μg mL−1 was the most active. Technically, this methodology allows the preparation of a combinatorial library of analogues with different structural characteristics depending on the nature of the modified α-amino acids employed in the synthesis

Transmitter and receiver equalizers optimization for PCI Express Gen6.0 based on PAM4

The continuously increasing bandwidth demand from new applications has led to the development of the new PCIe Gen6, reaching data rates of 64 GT/s and adopting PAM4 modulation scheme. While PAM4 solves the bandwidth constraint in high-speed interconnects, it brings new challenges for the physical channel analysis. Equalization (EQ) plays an important role even with PAM4 signaling. PCIe specification defines requirements to perform EQ at the transmitter (Tx) and at the receiver (Rx). During the EQ process, one combination of Tx/Rx EQ coefficients must be selected to meet the performance requirements of the system. Testing all possible coefficient combinations is prohibitive. Current industrial practice consists of finding a subset of combinations at post-silicon validation using maps of EQ coefficients. Finding this subset of coefficients is timeconsuming,along with all the new challenges imposed by PAM4. In this paper, we propose an optimization approach for PCIe Gen6 link EQ. Our proposal is based on a suitable objective function formulated over the channel operating margin (COM), which is a new figure of merit (FOM) adopted by standards of communications for signaling speeds beyond 25 Gbps.ITESO, A.C

Minimal invasive surgery in craniostenosis

En el presente trabajo se describe la experiencia en craneoestenosis con cirugía mínimamente invasiva, evaluando el diseño y eficacia de un nuevo craneotomo en cadáveres así como su aplicación clínica en un caso de sinostósis sagital con instrumentación endoscópica. Este procedimiento es sin duda un gran recurso en el tratamiento de las craneoestenosis brindando los beneficios de la cirugía mínimamente invasiva, eliminando la necesidad de grandes incisiones, disminuyendo el sangrado quirúrgico, reduciendo estancia hospitalaria y disminuyendo la morbilidad operatoria In this paper, we describe the experience with the use of endoscopic craniofacial procedures, evaluating the design and the efficacy of a new craniotome in cadavers and his clinical application in a case of sagittal synostosis for an endoscopic assisted cranioplasty. This procedure is a great option in the treatment of craniosynostosis, giving the benefits of minimal invasive surgery and eliminating the needing of big incisions, long hospital stay and reducing the postoperative morbidit

Jitter Tolerance Acceleration Using the Golden Section Optimization Technique

Post-silicon validation of high-speed input/output (HSIO) links is a critical process for product qualification schedules of computer platforms under the current time-to-market (TTM) commitments. The goal of post-silicon validation for HSIO links is to confirm design robustness of both receiver (Rx) and transmitter (Tx) circuitry in a real application environment. One of the most common ways to evaluate the performance of a HSIO link is to characterize the Rx jitter tolerance (JTOL) performance by measuring the bit error rate (BER) through the link under worst stressing conditions. However, JTOL testing is very time-consuming when executing at specification BER, and the testing time is extremely increased when considering manufacturing process, voltage, and temperature (PVT) test coverage for a qualification decision. In order to speed up this process, we propose a new approach for JTOL testing based on the golden section algorithm. The proposed method takes advantage of the fast execution of the golden section search with a high BER, while overcoming the lack of correlation between different BERs by performing a downward linear search at the actual target BER until no errors are seen. Our proposed methodology is validated by implementing it in a server HSIO link

A Holistic Methodology for System Margining and Jitter Tolerance Optimization in Post-Silicon Validation

The optimization of receiver analog circuitry in modern high-speed input/output (HSIO) links is a very time consuming post-silicon validation process. Current industrial practices are based on exhaustive enumeration methods to improve either the system margins or the jitter tolerance compliance test. In this paper, these two requirements are addressed in a holistic optimization-based approach. We propose an innovative objective function based on these two metrics. Our method employs Kriging to build a surrogate model based on system margining and jitter tolerance measurements. The proposed method is able to deliver optimal system margins and guarantee jitter tolerance compliance while substantially decreasing the typical post-Si validation time

El director de arte publicitario y las competencias del contexto visual con variables artísticas

El trabajo del director de arte dentro de una agencia publicitaria es la visualización estratégica, buscando soluciones a los retos gráficos en una comunicación visual cada vez más atractiva. Esto conlleva a que sus conocimientos están relacionados con el manejo conceptual y estético de la imagen.The work of the art director within an advertising agency is strategic visualization, seeking solutions to graphic challenges in an increasingly attractive communication. Therefore, this advertising creative has tactical knowledge that helps him generate stagings that impact the memory of consumers. In order to convert the gestures of the image and the components of the scenography into interpretable codes, the art directors rely on their ability to give a symbolic value to those elements with their strengths based on aesthetics and art