Timing Margin Research Articles

Multi-View Graph Learning for Path-Level Aging-Aware Timing Prediction

As CMOS technology continues to scale down, the aging effect—known as negative bias temperature instability (NBTI)—has become increasingly prominent, gradually emerging as a key factor affecting device reliability. Accurate aging-aware static timing analysis (STA) at the early design phase is critical for establishing appropriate timing margins to ensure circuit reliability throughout the chip lifecycle. However, traditional aging-aware timing analysis methods, typically based on Simulation Program with Integrated Circuit Emphasis (SPICE) simulations or aging-aware timing libraries, struggle to balance prediction accuracy with computational cost. In this paper, we propose a multi-view graph learning framework for path-level aging-aware timing prediction, which combines the strengths of the spatial–temporal Transformer network (STTN) and graph attention network (GAT) models to extract the aging timing features of paths from both timing-sensitive and workload-sensitive perspectives. Experimental results demonstrate that our proposed framework achieves an average MAPE score of 3.96% and reduces the average MAPE by 5.8 times compared to FFNN and 2.2 times compared to PNA, while maintaining acceptable increases in processing time.

Extraperitoneal single-port robot-assisted radical prostatectomy: Short-term outcomes and technique description.

We evaluated the feasibility, safety, and learning curve of extraperitoneal single-port robot-assisted radical prostatectomy (SP-RARP) and introduced innovative surgical techniques to maintain the instrument positions during the procedures. A cohort of 100 patients underwent extraperitoneal SP-RARP at our institution from December 2021 to April 2023. The procedures were performed by an experienced urology surgeon utilizing two surgical techniques for dissecting the posterior aspect of the prostate-"changing instrument roles" and "using camera inversion"-to prevent positional shifts between the camera and instruments. The mean operation time for SP-RARP was 93.58 minutes, and the mean console time was 65.16 minutes. The mean estimated blood loss during the procedures was 109.30 mL. No cases necessitated conversion to multi-port robot, laparoscopy, or open surgery, and there were no major complications during the hospital stay or in the short-term follow-up. Early outcomes of post-radical prostatectomy indicated a biochemical recurrence rate of 4.0% over a mean follow-up duration of 6.40 months, with continence and potency recovery rates of 92.3% and 55.8%, respectively. Analysis of the learning curve showed no significant differences in operation time, console time, and positive surgical margin rates between the initial and latter 50 cases. Extraperitoneal SP-RARP is a feasible and safe option for the treatment of localized prostate cancer in skilled hands. Continued accrual of cases is essential for future comparisons of SP-RARP with multiport approaches.

Efficacy of robot-assisted partial nephrectomy compared to conventional laparoscopic partial nephrectomy for completely endophytic renal tumor: a multicenter, prospective study

BackgroundThis study aimed to compare the efficacy of robot-assisted partial nephrectomy for completely endophytic renal tumors with the reported outcomes of conventional laparoscopic partial nephrectomy and investigate the transition of renal function after robot-assisted partial nephrectomy.MethodsWe conducted a prospective, multicenter, single-arm, open-label trial across 17 academic centers in Japan. Patients with endophytic renal tumors classified as cT1, cN0, cM0 were included and underwent robot-assisted partial nephrectomy. We defined two primary outcomes to assess functional and oncological aspects of the procedure, which were represented by the warm ischemic time and positive surgical margin, respectively. Comparisons were made using control values previously reported in laparoscopic partial nephrectomy studies. In the historical control group, the warm ischemia time was 25.2, and the positive surgical margin was 13%.ResultsOur per-protocol analysis included 98 participants. The mean warm ischemic time was 20.3 min (99% confidence interval 18.3–22.3; p < 0.0001 vs. 25.2). None of the 98 participants had a positive surgical margin (99% confidence interval 0–5.3%; p < 0.0001 vs. 13.0%). The renal function ratio of eGFR before and after protocol treatment multiplied by splits was 0.70 (95% confidence interval: 0.66–0.75). Factors such as preoperative eGFR, resected weight, and warm ischemic time influenced the functional loss of the partially nephrectomized kidney after robot-assisted partial nephrectomy.ConclusionsRobot-assisted partial nephrectomy for completely endophytic renal tumors offers a shorter warm ischemia time and comparable positive surgical margin rate compared with conventional laparoscopic partial nephrectomy.

Modeling evolutionary power spectral density functions of strong earthquakes via copulas

This paper proposes a new approach for analyzing seismic accelerograms using the evolutionary Power Spectral Density function (EPSD). The accelerogram of an earthquake can be accurately modeled and simulated from its spectrogram, based on the oscillatory stochastic processes theory. To adequately characterize a spectrogram that is consistent with the response spectra, a parametric model with 16 parameters is proposed. This model describes the square of the amplitude spectrum, an envelope of the square of the accelerogram, and a copula that constructs a time–frequency model from the time and frequency marginals. The use of copulas to model a bivariate probability distribution is a common practice in statistics, particularly when the marginal distributions are known. The periodogram can be viewed as an unnormalized probability density function, where the total energy serves as the normalization constant, since the total energy of a seismic motion is always finite. Additionally, a reduced model consisting of only 10 parameters is presented, which may be especially valuable when only shear wave effects are relevant.

Initiation and evolution of an epicontinental shelf‐slope margin in an actively contracting deep‐water basin: The Eocene Aínsa Basin, southern Pyrenees (Spain)

AbstractThe shelf‐slope margin is a geomorphic zone with a change in gradient between subaqueous shelves and slopes, which extends towards the submarine basin‐floor. It is important because it partitions distinct sedimentary and biogenic processes between the shallow and deep‐water realms. The initiation of a shelf‐slope profile from pre‐existing conditions, and the evolution of shelf margins in space and time has been the focus of numerous studies, particularly from seismic data sets on passive margins, although markedly less‐so from active tectonic settings. This study documents the initiation and evolution of a shelf‐slope margin in the well‐studied Eocene Aínsa Basin (Spanish Pyrenees) through the segmentation of a mixed carbonate‐siliciclastic ramp via contractional tectonics and differential subsidence. The basinward propagation of a series of thrusts through the ramp allowed the maintenance of shallow‐water, predominantly carbonate sedimentation on their uplifted hanging wall anticlines. Conversely, the deepened foot wall synclines became muddy slope environments, and their axes became the main loci of siliciclastic turbidity current bypass and deposition. The deflection of turbidity currents around uplifted areas towards the synclinal lows allowed for the continuation of carbonate production at the bathymetric highs, which kept pace with subsidence. The interface between shallow‐ and deep‐water sedimentation (i.e. the shelf‐slope margin) was an erosional and composite submarine scarp surface generated by several phases of large‐scale mass wasting of the aggrading shelf carbonates, and healing by onlap of slope turbidites against the scarp. Continued thrust propagation and basin deepening led to the progressive headward degradation of the surfaces, resulting in an apparent retrogradation of the shelf‐slope margin and onlapping slope deposits. This model for the tectonically controlled conversion of a submarine ramp into a shelf‐slope profile contrasts with conventional models that consider shelf‐slope margins to be inherently progradational after initiation. This study also challenges the notion that large‐scale degradational surfaces and thick successions of submarine landslides are inherently diagnostic of canyons and their fill.

Low-error, high-speed, and large-scale hardware implementation of retinal photoreceptor cells: Cone and rod cells

In recent times, there has been a significant focus on creating prosthetics and medical interventions to aid in the treatment of diseases, recovery, and the improvement of biological functions. Researchers have particularly directed their attention toward developing hardware models for delicate biological parts such as the brain, heart, nervous system, and. One area of particular interest is the retina, which is the thinnest and innermost layer of the eye. This research paper focuses on the development of a high-speed and low-error hardware implementation for retinal cone and rod cells. Current mathematical models often use multiple nonlinear functions to describe the behavior of these cells. However, these nonlinear functions can sometimes be limiting in terms of speed. In this study, we explore the use of trigonometric functions to approximate the non-linear properties of retinal cone and rod cells, allowing for improved performance. The results of the simulation show that the suggested model is in line with the functioning of primary cone and rod cells, particularly in relation to time characteristics, dynamic response, and margin of error. By implementing the proposed model in Large-Scale (300 cell) on a Virtex-5 Field Programmable Gate Array (FPGA) board, notable benefits were observed. One of these advantages includes increasing the synthesis frequency of the proposed model by 3.35 and 3.44 times faster than the original model for the cone cell and rod cell, respectively. Another advantage is the ability to implement 300 cells of the proposed models on the FPGA, compared to the implementation of a single cell of the original models, with only a two-fold increase in the amount of hardware resources used. The proposed framework is legitimate and features a compact hardware size and suitable network frequency, as demonstrated by the outcomes from implementing the hardware on the Virtex-5 reconfigurable board (FPGA).

Autonomous construction of lunar infrastructure with in-situ boulders

Significant infrastructure is required to establish a long-term presence of humans on the lunar surface. In-situ resource utilization (ISRU) is a fundamental approach to ensure the viability of such construction. Here, we investigate the feasibility of constructing blast shields as one example of lunar infrastructure using unprocessed lunar boulders and an autonomous robotic excavator. First, we estimate the volume of unprocessed material required for the construction of blast shield segments. Secondly, we quantify the amount of available boulders in two exploration zones (located at the Shackleton-Henson Connecting Ridge and the Aristarchus Plateau pyroclastic deposit) using LRO NAC images and boulder size-frequency distribution laws. In addition, we showcase an alternative approach that relies on Diviner rock abundance data. Thirdly, we use a path planning algorithm to derive the distance, energy, and time required to collect local material and construct blast shield elements. Our results show that our construction method requires two orders of magnitudes less energy than alternative ISRU construction methods, while maintaining realistic mission time and payload capacity margins.

Robotic versus laparoscopic hepatectomy for liver malignancies (ROC'N'ROLL): a single-centre, randomised, controlled, single-blinded clinical trial

Robotic hepatectomy (RH) has been increasingly adopted for the treatment of liver malignancies despite lacking evidence from randomised trials. We aimed to determine the effect of RH compared to laparoscopic hepatectomy (LH) on quality of life in patients undergoing minimally invasive hepatectomy for liver malignancies. This single-blinded, randomised trial was conducted at a tertiary care academic centre (DRKS00027531). Patients with resectable liver malignancies were assessed for eligibility and randomly assigned to either RH or LH with stratification by type of malignancy and difficulty of resection. Patients were blinded to the treatment allocation. The primary outcome was the mean quality of life within 90 days after surgery, measured with the role functioning scale of the European Organisation for Research and Treatment of Cancer QLQ-C30 questionnaire. Secondary outcomes included operating time, morbidity, blood loss, conversion rate, postoperative recovery, and resection margin status. Between February 21, 2022, and Sep 18, 2023, 80 patients (RH: n=41, LH: n=39) were included and analysed on an intention-to-treat basis. Role functioning scores did not differ between RH and LH (mean [SD], 74.3 [23.3] versus 79.6 [22.3]; mean difference-5.3, 95% CI-15.6 to 5.1, p=0.547). The comprehensive complication index was not significantly different between the study groups (8.9 [23.1] versus 15.5 [23.9], p=0.137). There were no differences in other perioperative outcomes. RH yielded similar outcomes in quality of life and can be considered a safe alternative to LH. None.

Numerical Study on Valve Closing Criteria during Pump-turbine Start-up on Pump Mode

Abstract Vibrations of exhaust pipes have been observed in some hydropower stations during the exhaust process of pump-turbine start-up on pump mode due to water ingress into the pipes. It may have a safety risk for the pump-turbine start-up process when exhaust pipes are operating under the compressed air-water two phase flow. Since the numerical simulation researches about pump start-up process have been rarely reported and the development of flow field in exhaust pipe is lack of quantitative cognition, it calls for an urgent need to supplement related works. In this paper, the transient full-channel two-phase numerical simulation research on the pump mode return water exhaust process of a pumped power station is carried out by Reynolds-Averaged Navier-Stokes approach. This work put emphasis on the characteristics of cone water level, runner torque and air speed in exhaust pipes after the compressed air released from the runner chamber. Then development laws and relationship with the exhaust valve closing timing are analysed and concluded. Results show that the cone water level, runner torque and air speed pulsation signal of exhaust pipes can be used as exhaust valve closing criteria, and the third criterion has the largest time margin.

Investigation of timing margin in single-flux-quantum 4 bit adders for increasing clock frequency of gate-level-pipelined circuits

This study investigates the timing margin required to handle fluctuations and variations in superconductor single-flux-quantum gate-level-pipelined adders; a smaller timing margin would improve the clock frequencies of gate-level-pipelined circuits. To evaluate timing margins, we demonstrated three 4 bit adders with 50-, 75-, and 100 GHz target clock frequencies using a 1.0 μm process. We estimated that the required timing margin of the adders was 2.1 ps. This indicates that previously reported gate-level-pipelined circuits operating at 30–60 GHz could operate at higher clock frequencies by reducing the timing margins.

SPIS: Signal Processing for Integrated Sensing Technologies Using 6G Networks with Machine Learning Algorithms

The proliferation of integrated sensing techniques in Sixth Generation (6G) networks is an increasingly significant aspect in facilitating efficient end-to-end communication for all users. The suggested methodology employs a digital signal processed with terahertz bandwidth to assess the impact of 6G networks. The primary focus lies in the design of 6G networks, emphasizing key parameters such interference, loss, signal strength, signal-to-noise ratio, and dual band channels. The aforementioned factors are combined with two machine learning algorithms in order to determine the extent of spectrum sharing among all available resources. Thus suggested approach for detecting signals in the terahertz communication spectrum is evaluated using 10 devices across four situations, which involve interference, signal loss, strength, and time margins for integrated sensing. Also the assumptions are based on signal processing devices operating within millimeter waves ranging from 5 to 10 terahertz. Interference and losses in the specified spectrum are seen to be less than 1%, but the time margin for integrated sensing with 99% maximized signal intensity remains at 85%.

Loss of function of the meibomian glands among HIV and AIDS individuals undergoing antiretroviral therapy

Background: Meibomian gland dysfunction (MGD) is one of the most encountered diseases in the clinical practice but appears to be underappreciated as it does not cause blindness. Meibomian gland dysfunction is a multifactorial and complex disorder of the ocular surface.Aim: This study aims to evaluate the characteristics of the meibomian glands in individuals living with HIV and AIDS undergoing antiretroviral therapy.Setting: The study was conducted at the antiretroviral (ARV) clinic, Mankweng Hospital.Methods: This was a prospective study conducted with 37 HIV and AIDS participants and 20 healthy controls. All participants were assessed using the Ocular Surface Diseases Index (OSDI) score and, tear break-up time and lid margin regularity (using the slit-lamp biomicroscopy). The loss of the meibomian glands was evaluated using the Marx’s line. For this study, this line represented a clinical parameter of meibomian function.Results: The OSDI score was significantly higher in the HIV and AIDS group than that of the control participants (39.95 ± 18.65 and 13.00 ± 9.09, respectively, P 0.05). The tear breakup time (TBUT) for the HIV and AIDS study group was lower than that of the control group (7.95 ± 3.54 and 9.90 ± 3.70, respectively, P 0.05). The HIV and AIDS participants showed greater meibomian gland loss relative to the healthy controls (9.30 ± 4.97 and 5.70 ± 2.1, P 0.05).Conclusion: The loss of eyelid meibomian glands is common in people living with HIV and AIDS in comparison with healthy controls.Contribution: Although there is a decrease in sight-threatening complications in the era of ARVs, ocular surface disorders (OSD) are still commonly found, which may reduce the quality of life of HIV and AIDS individuals.

Programmable delay line with inherent duty cycle correction

In the recent HBM2E IO design, clock is transmitted differentially to the external DRAM and duty cycle distortion (DCD) could add to the differential clock due to traversing multiple stages in DRAM. At higher data rates, the DCD from the differential clock imposes restrictions on the timing margins. In the current work, Tx clock path is added with DCC feature to compensate for any DCD errors introduced by the clock network in the external DRAM. Linearity of the DCC is critical metric when the clock is differential and running at high speed. A new programmable delay line with inherent DCC design with good linearity is presented in this paper.

Improved post-radiation behavior of FinFET based CMOS with workfunction modulated gate

The total ionizing dose (TID) effect of modulated gate workfunction (MGW) FinFET based CMOS inverter is designed and analyzed. The post radiation analysis of the voltage transfer characteristics, noise margin and propagation delay are demonstrated. The incorporation workfunction modulation engineering enhances the OFF-state performance, and maintains positive threshold voltage for both the pre and post radiation condition. 2-decade improvement is noticed for the both n-FinFET and p-FinFET. In addition, the proposed technique offers minimum propagation delay time and acceptable noise margin range even after 2000 krad of radiation dose. The analysis and comparison of the results is done by the 3-D TCAD simulator.

Treatment of excessive gingival display using conventional esthetic crown lengthening versus computer guided esthetic crown lengthening: (a randomized clinical trial)

BackgroundSurgical guides have been proposed in an attempt to reach more predictable outcomes for esthetic crown lengthening. The objective of the present study was to evaluate the effectiveness of esthetic crown lengthening using 3D-printed surgical guides in the management of excessive gingival display due to altered passive eruption type 1B.Materials and methodsSixteen patients diagnosed with altered passive eruption type 1B, were divided into two groups. In the control group, the procedure was carried out conventionally, and in the study group, a dual surgical guide was used. The parameters of wound healing (swelling, color, probing depth, bleeding index, and plaque index), pain scores, gingival margin stability, and operating time were assessed at 1 week, 2 weeks, 3 months, and 6 months postoperatively.ResultsThere was no statistically significant difference in terms of wound healing, pain scores, and gingival margin stability between both groups at different time intervals (P = 1), however, there was a statistical difference between both groups in terms of operating time with the study group being significantly lower (P < 0.001).ConclusionDigitally assisted esthetic crown lengthening helps shorten the operating time and reduces the possibility of human errors during the measurements. This will be useful in helping practitioners achieve better results.Practical implicationsThe conventional method remains to be the gold standard. However, shorter operating time and lower margins for errors will help reduce costs as the chair side time is reduced as well as the possibility for a second surgery is lower. This will improve patient satisfaction as well.

Individuals with knee osteoarthritis show few limitations in balance recovery responses after moderate gait perturbations

BackgroundKnee osteoarthritis causes structural joint damage. The resultant symptoms can impair the ability to recover from unexpected gait perturbations. This study compared balance recovery responses to moderate gait perturbations between individuals with knee osteoarthritis and healthy individuals. MethodsKinematic data of 35 individuals with end-stage knee osteoarthritis, and 32 healthy individuals in the same age range were obtained during perturbed walking on a treadmill at 1.0 m/s. Participants received anteroposterior (acceleration or deceleration) or mediolateral perturbations during the stance phase. Changes from baseline in margin of stability, step length, step time, and step width during the first two steps after perturbation were compared between groups using a linear regression model. Extrapolated center of mass excursion was descriptively analyzed. FindingsAfter all perturbation modes, extrapolated center of mass trajectories overlapped between individuals with knee osteoarthritis and healthy individuals. Participants predominantly responded to mediolateral perturbations by adjusting their step width, and to anteroposterior perturbations by adjusting step length and step time. None of the perturbation modes yielded between-group differences in changes in margin of stability and step width during the first two steps after perturbation. Small between-group differences were observed for step length (i.e. 2 cm) of the second step after mediolateral and anteroposterior perturbations, and for step time (i.e. 0.01–0.02 s) of first step after mediolateral perturbations and the second step after outward and belt acceleration perturbations. InterpretationDespite considerable pain and damage to the knee joint, individuals with knee osteoarthritis showed comparable balance recovery responses after moderate gait perturbations to healthy participants.

Single-port vs multi-port robot-assisted partial nephrectomy: A single center propensity score-matched analysis

Introduction and objectivesThe aim of the study is to compare key outcomes of Single-Port (SP) and Multi-Port (MP) robot-assisted partial nephrectomy (RAPN). MethodsA retrospective analysis was conducted on our prospectively collected database of patients who underwent SP-RAPN or MP-RAPN at our institution from January 2021 to August 2023. To adjust for potential baseline pre-operative confounders, a 1:1 propensity-score matching analysis (PSMa) was performed. The primary endpoint was to compare perioperative outcomes between the two groups. The secondary endpoint was to compare the achievement of the “Trifecta” outcome (defined as negative surgical margins, absence of high-grade complications and change in eGFR values (ΔeGFR) < 10% at 6 months follow-up) in the matched cohort. ResultsAfter PSMa, 30 SP cases were matched 1:1 to 30 MP cases. In the matched cohort, there were no significant differences between SP and MP approaches in operative time, estimated blood loss, ischemia time, transfusions rate, intraoperative complications, postoperative complications, and positive surgical margin rates. Patients who underwent SP-RAPN had a shorter median length of stay [25 (IQR:24.0–34.5) vs 34 (IQR:30.2–48.0) hours, p < 0.003]. The Trifecta outcome was achieved in 16 (57%) of SP patients and 17 (63%) of MP patients (p = 0.8). ConclusionsSP-RAPN can be safely implemented in a Center with an established MP-RAPN program. Despite being early in the SP-RAPN experience, key surgical outcomes are not compromised. While offering comparable perioperative and short-term functional outcomes, SP-RAPN can translate into faster recovery and shorter LOS, paving the way for outpatient robotic surgery.

Thermal runaway criterion as a basis for the protection of high-temperature superconductor magnets

High-temperature superconductor (HTS) based high-field magnet systems are essential for particle accelerators and fusion energy applications. Quench protection of such magnets is difficult owing to a slow quench propagation velocity in HTS. While in conventional NbTi and Nb3Sn-based magnets, a normal zone expands typically quickly, and the stored energy is dissipated across a large volume of the windings, a normal zone in an HTS magnet propagates slowly and, thus, can heat up quickly to high temperatures destroying the conductor. At the same time, growing experimental evidence suggests that HTS conductors can operate in a stable dissipative flux flow regime for a substantial range of operational currents before entering an irreversible thermal runaway. Therefore, a new protection paradigm for HTS magnets has emerged, aiming to prevent quenching, using advanced diagnostics to detect the dissipative regime onset. In the present paper, we propose a simple criterion for the thermal runaway in HTS conductors and calculate allowable temperature margins within which an HTS magnet can be operated safely. Outside of those temperature margins, a common quench integral approach may be used to estimate the upper boundary of the time margin for activating the protection system. We verify the applicability of our approach by comparing the calculated runaway conditions for a Bi-2223 conductor with the experimentally measured values. The thermal and time margins can define the quench protection system’s requirements for implementing the quench-avoiding protection paradigm.

Postoperative permanent section evaluation of Mohs micrographic surgery debulk specimens does not result in upstaging of cutaneous squamous cell carcinoma compared to stage at the completion of surgery: A retrospective case series

BackgroundMohs micrographic surgery (MMS) is used for the treatment of high-risk cutaneous squamous cell carcinoma (cSCC). MMS examines the surgical margins in real time and does not commonly examine the central component of the tumor. ObjectiveTo determine if debulk specimens provide additional details relevant to tumor staging not gained from routine MMS. MethodsA retrospective chart review of debulk specimens taken during MMS for cSCC was conducted. Dermatopathology reports were analyzed and tumors were staged using Brigham and Women's Hospital (BWH) and American Joint Committee on Cancer’s 8th edition (AJCC8) staging systems. ResultsPermanent section evaluation of debulk specimens did not result in clinically meaningful information for staging that could not be gained from MMS layers or initial biopsy analysis. LimitationsA single institution, and the small sample size of 39 tumors. ConclusionsEvaluation of debulk specimens during MMS may not always be an effective use of time or healthcare resources.

A novel synchronized data-driven composite scheme to enhance photovoltaic (pv) integrated power system grid stability

The performance of power networks is enhanced by the penetration of solar energy, which helps to equate continuously the generation and demand power imbalance. However, the time margin that grids must adapt to unforeseen frequency fluctuations and restore generation-demand equivalency is reduced by these linkages. Consequently, it exerts the stability and performance of the power grid at risk. Thus, it becomes vital to assess real-time system data and to recognize and implement suitable remedies to maintain a healthy system performance. In order to improve grid stability in power networks that have solar energy penetration, this manuscript suggests a data driven integrated framework. The proposed approach is a two-step framework wherein the first stage assesses impending transient instability in the system through novel Instability Evaluation (IE). Step two involves creating and deploying a Decision Boundary based Control (DBC) to stabilize an unstable system following an emergency control strategy. An IE module employing short-synchronized movement data is presented for evaluating post-disturbance transient stability (TS). In the initial cycles following the fault initiation, the IE projects the impending transient instability. Next, an innovative DBC creates an emergency remedial system for unstable processes that determines the nature, magnitude and location of the remedial action. The DBC assesses pertinent action sets that it implements to sustain system stability using a proposed Decision Assisted Inference (DAI) technique. The simulation investigations validate the aptness of suggested analysis on the performance of power system with and without PV and topological variations.