scholarly journals A Modified Lotka–Volterra Model for Diffusion and Substitution of Multigeneration DRAM Processing Technologies

2017 ◽  
Vol 2017 ◽  
pp. 1-12
Author(s):  
Hui-Chih Hung ◽  
Yu-Chih Chiu ◽  
Muh-Cherng Wu

We attempt to develop an effective forecasting model for the diffusion and substitution of multigeneration Dynamic Random Access Memory (DRAM) processing technologies. We consider market share data and propose a modified Lotka–Volterra model, in which an additional constraint on the summation of market share is introduced. The mean absolute error is used to measure the accuracy of our market share predictions. Market share data in DRAM industries from quarter one (Q1) of 2005 to 2013 Q4 is collected to validate the prediction accuracy. Our model significantly outperforms other benchmark forecasting models of both revenue and market share data, including the Bass and Lotka–Volterra models. Compared to prior studies on forecasting the diffusion and substitution of multigeneration technologies, our model has two new perspectives: (1) allowing undetermined number of multigeneration technologies and inconsecutive adoption of new technologies and (2) requiring less data for forecasting newborn technologies.

2020 ◽  
Vol 14 (10) ◽  
pp. 1197-1203
Author(s):  
Ayse Arikan ◽  
Murat Sayan ◽  
Osman Doluca

Introduction: Currently, several molecular assays are available to detect and quantify HBV DNA in clinical samples. We aimed to characterize and compare the clinical performance of newly designed NeuMoDx PCR to the existing artus PCR. Methodology: The plasma HBV DNA levels of 96 clinical and 5 external quality control samples were measured by NeuMoDx and artus assays simultaneously in Kocaeli University, Turkey. The linearity, agreement and the correlation between two assays were determined by Deming regression analysis, Bland-Altman plotting, the chi-square and the relative absolute error statistical analyzes. For all statistical analyzes, the XLSTAT statistical program was used. Results: The mean (standard deviation; SD) age was 45.07 ± 12.29. HBsAg S/Co median (range) was 4,273.4 ± 1,138.1 and ALT U/L median (range) was 27 ± 16. The mean (SD) of HBV DNA was 1.46+E6 ± 1.0+E4 for NeuMoDx and 1.54+E5 ± 4.7 + E4 for artus assays. The Deming regression indicates a linear correlation (95% confidence). The chi-square test indicates strong correlation (p < 0.001). Bland-Altman analysis confirms that the measurement difference is acceptable. The relative absolute error analysis for artus showed relatively less and more consistent error rate. With 5 external quality check samples, the statistical significance was low (p = 0.566). Conclusions: The NeuMoDx HBV assay showed an excellent analytical performance by providing a rapid, high throughput technology in a random-access testing system in clinical samples and may be a new solution for viral load quantification in the management of HBV infections.


Mathematics ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 998 ◽  
Author(s):  
Min-Chi Chiu ◽  
Tin-Chih Toly Chen ◽  
Keng-Wei Hsu

Existing methods for forecasting the productivity of a factory are subject to a major drawback—the lower and upper bounds of productivity are usually determined by a few extreme cases, which unacceptably widens the productivity range. To address this drawback, an interval fuzzy number (IFN)-based mixed binary quadratic programming (MBQP)–ordered weighted average (OWA) approach is proposed in this study for modeling an uncertain productivity learning process. In the proposed methodology, the productivity range is divided into the inner and outer sections, which correspond to the lower and upper membership functions of an IFN-based fuzzy productivity forecast, respectively. In this manner, all actual values are included in the outer section, whereas most of the values are included within the inner section to fulfill different managerial purposes. According to the percentages of outlier cases, a suitable forecasting strategy can be selected. To derive the values of parameters in the IFN-based fuzzy productivity learning model, an MBQP model is proposed and optimized. Subsequently, according to the selected forecasting strategy, the OWA method is applied to defuzzify a fuzzy productivity forecast. The proposed methodology has been applied to the real case of a dynamic random access memory factory to evaluate its effectiveness. The experimental results indicate that the proposed methodology was superior to several existing methods, especially in terms of mean absolute error, mean absolute percentage error, and root mean square error in evaluating the forecasting accuracy. The forecasting precision achieved using the proposed methodology was also satisfactory.


2017 ◽  
Vol 34 (01) ◽  
pp. 1740006 ◽  
Author(s):  
Xiaoxia Fu ◽  
Ping Zhang ◽  
Juzhi Zhang

In the background of big data era, the ability to accurately forecast the number of the Internet users has considerable implications for evaluating the growing trend of a newly-developed business. In this paper, we use four models, the Gompertz model, the Logistic model, the Bass model, and the Lotka–Volterra model, to forecast the Internet population in China with the historical data during 2007 to 2014. We compare the prediction accuracy of the four models using the criterions such as the mean absolute percentage error (MAPE), the mean absolute error (MAE) and the root mean square error (RMSE). We find that the Lotka–Volterra model has the highest prediction accuracy. Moreover, we use the Lotka–Volterra model to investigate the relationship between the rural Internet users and the urban Internet users in China. The estimation results show that the relationship is commensalism.


Author(s):  
Phil Schani ◽  
S. Subramanian ◽  
Vince Soorholtz ◽  
Pat Liston ◽  
Jamey Moss ◽  
...  

Abstract Temperature sensitive single bit failures at wafer level testing on 0.4µm Fast Static Random Access Memory (FSRAM) devices are analyzed. Top down deprocessing and planar Transmission Electron Microscopy (TEM) analyses show a unique dislocation in the substrate to be the cause of these failures. The dislocation always occurs at the exact same location within the bitcell layout with respect to the single bit failing data state. The dislocation is believed to be associated with buried contact processing used in this type of bitcell layout.


Author(s):  
Ramachandra Chitakudige ◽  
Sarat Kumar Dash ◽  
A.M. Khan

Abstract Detection of both Insufficient Buried Contact (IBC) and cell-to-cell short defects is quite a challenging task for failure analysis in submicron Dynamic Random Access Memory (DRAM) devices. A combination of a well-controlled wet etch and high selectivity poly silicon etch is a key requirement in the deprocessing of DRAM for detection of these types of failures. High selectivity poly silicon etch methods have been reported using complicated system such as ECR (Electron Cyclotron Resonance) Plasma system. The fact that these systems use hazardous gases like Cl2, HBr, and SF6 motivates the search for safer alternative deprocessing chemistries. The present work describes high selectivity poly silicon etch using simple Reactive Ion Etch (RIE) plasma system using less hazardous gases such as CF4, O2 etc. A combination of controlled wet etch and high selectivity poly silicon etch have been used to detect both IBC and cell-to-cell shorts in submicron DRAMs.


Author(s):  
Felix Beaudoin ◽  
Stephen Lucarini ◽  
Fred Towler ◽  
Stephen Wu ◽  
Zhigang Song ◽  
...  

Abstract For SRAMs with high logic complexity, hard defects, design debug, and soft defects have to be tackled all at once early on in the technology development while innovative integration schemes in front-end of the line are being validated. This paper presents a case study of a high-complexity static random access memory (SRAM) used during a 32nm technology development phase. The case study addresses several novel and unrelated fail mechanisms on a product-like SRAM. Corrective actions were put in place for several process levels in the back-end of the line, the middle of the line, and the front-end of the line. These process changes were successfully verified by demonstrating a significant reduction of the Vmax and Vmin nest array block fallout, thus allowing the broader development team to continue improving random defectivity.


2020 ◽  
Vol 12 (2) ◽  
pp. 02008-1-02008-4
Author(s):  
Pramod J. Patil ◽  
◽  
Namita A. Ahir ◽  
Suhas Yadav ◽  
Chetan C. Revadekar ◽  
...  

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1401
Author(s):  
Te Jui Yen ◽  
Albert Chin ◽  
Vladimir Gritsenko

Large device variation is a fundamental challenge for resistive random access memory (RRAM) array circuit. Improved device-to-device distributions of set and reset voltages in a SiNx RRAM device is realized via arsenic ion (As+) implantation. Besides, the As+-implanted SiNx RRAM device exhibits much tighter cycle-to-cycle distribution than the nonimplanted device. The As+-implanted SiNx device further exhibits excellent performance, which shows high stability and a large 1.73 × 103 resistance window at 85 °C retention for 104 s, and a large 103 resistance window after 105 cycles of the pulsed endurance test. The current–voltage characteristics of high- and low-resistance states were both analyzed as space-charge-limited conduction mechanism. From the simulated defect distribution in the SiNx layer, a microscopic model was established, and the formation and rupture of defect-conductive paths were proposed for the resistance switching behavior. Therefore, the reason for such high device performance can be attributed to the sufficient defects created by As+ implantation that leads to low forming and operation power.


Sign in / Sign up

Export Citation Format

Share Document