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Cohesive failure is one of the primary reasons for low-temperature cracking in asphalt pavements. Understanding the micro-level mechanism is crucial for comprehending cohesive failure behavior. However, previous literature has not fully reported on this aspect. Moreover, there has been insufficient attention given to the correlation between macroscopic and microscopic failures. To address these issues, this study employed molecular dynamics simulation to investigate the low-temperature tensile behavior of asphalt binder. By applying virtual strain, the separation work during asphalt binder tensile failure was calculated. Additionally, a correlation between macroscopic and microscopic tensile behaviors was established. Specifically, a quadrilateral asphalt binder model was generated based on SARA fractions. By applying various combinations of virtual strain loading, the separation work at tensile failure was determined. Furthermore, the impact of strain loading combinations on separation work was analyzed. Normalization was employed to establish the correlation between macroscopic and microscopic tensile behaviors. The results indicated that thermodynamic and classical mechanical indicators validated the reliability of the tetragonal asphalt binder model. The strain loading combination consists of strain rate and loading number. All strain loading combinations exhibited the similar tensile failure characteristic. The critical separation strain was hardly influenced by strain loading combination. However, increasing strain rate significantly enhanced both the maximum traction stress and separation work of the asphalt binder. An increment in the loading number led to a decrease in separation work. The virtual strain combination of 0.5%-80 provided a more accurate representation of the actual asphalt's tensile behavior trend., QC 20231115

Previous research suggests that investment-cash flow sensitivity (ICS) has arisen from agency costs. This study investigates whether equity-based compensation (EBC) reduces these costs. We find that ICS is lower when companies grant EBC to chief executive officers (CEOs). EBC with long-term vesting periods, and especially with graded vesting conditions, is associated with a lower ICS. EBC with performance hurdles is associated with higher sensitivity. However, when the performance hurdles are set as a relative market index rather than an absolute target, the sensitivity becomes lower. Our results suggest that appropriately designed EBC plays an important role in mitigating investment-related agency problems.

Xiang-Rong Bai,1,* Jing-Rong Cao,2,* Zhi-Zhou Wang,1 Wen-Chao Li,1 Dian-Dian Chen,2 Ran Lou,3 Xin Qu,4 Su-Ying Yan1 1Department of Pharmacy, Xuan Wu Hospital Capital Medical University, National Gerontic Disease Clinical Research Center, Beijing, 100053, People’s Republic of China; 2Department of Clinical Laboratory, Xuan Wu Hospital Capital Medical University, National Gerontic Disease Clinical Research Center, Beijing, 100053, People’s Republic of China; 3Department of Intensive Medicine, Xuan Wu Hospital Capital Medical University, National Gerontic Disease Clinical Research Center, Beijing, 100053, People’s Republic of China; 4Intensive Care Unit, Department of Neurosurgery, Xuan Wu Hospital Capital Medical University, National Gerontic Disease Clinical Research Center, Beijing, 100053, People’s Republic of China*These authors contributed equally to this workCorrespondence: Su-Ying Yan, Department of Pharmacy, Xuan Wu Hospital Capital Medical University, National Gerontic Disease Clinical Research Center, No. 45 Changchun Street, Xi Cheng District, Beijing, 100053, People’s Republic of China, Tel/Fax +86 10-63012837, Email yansuying10@sina.cnPurpose: Tigecycline is an agent for carbapenemase-producing Klebsiella pneumonia (KPC-KP), given its penetration into lung tissues. Our study focused on the molecular and clinical efficacy of tigecycline for hospital-acquired pneumonia (HAP) in the ICU.Patients and Methods: A retrospective cohort study of 52 adult KPC-KP HAP patients by searching hospital medical records from January 2018 to December 2020 was established to investigate the epidemiology of KPC-KP infections for tigecycline treatment and the associated clinical efficacy of tigecycline. The KPC-KP isolates underwent multilocus sequence typing. Molecular typing, antimicrobial resistance, and virulence profiling were also analyzed by whole-genome sequencing of KPC-KP.Results: Among 52 patients with KPC-KP, the ICU mortality rate

The use of reclaimed asphalt pavement (RAP) is a hot research topic in the field of road engineering, as there are still many issues to overcome so as to become standard engineering applications. The diffusion of virgin/aged asphalt binder is a key process to improve RAP performance. In this study, the asphalt binder diffusion models were developed by molecular dynamics (MD) simulation. Two kinds of bio-rejuvenators (BR-1 and BR-5) were chosen to represent the straight-chain and aromatic structures, respectively. The method of relative concentration, radial distribution function (RDF), and microstructure morphology were used to evaluate the effect of bio-rejuvenators on the diffusion process of virgin/aged asphalt binder. The results showed that bio-rejuvenators had a positive effect on the fusion process between virgin and aged asphalt binder. The volume diffusion coefficient based on asphalt binder diffusion models indicated that the bio-rejuvenators accelerated the fusion process between the virgin and asphalt binder. After adding bio-rejuvenators to the aged asphalt binder, the agglomeration intensity in the SARA fractions was reduced to different degrees. Due to the aging of asphalt binder, asphaltenes formed different types of micro-stacking phenomena such as “T-shaped stacking,” “Face to Face stacking,” and “Offset Face to Face stacking.” The bio-rejuvenators of BR-1 and BR-5 exerted different regenerative effects during the diffusion process of aged asphalt binder. For BR-1, the “Pull-Out” and “Intercalation” effect can be observed in the process of asphaltene deagglomeration. “Pull-Out” is the main regenerative effect of BR-5 in aged asphalt binder. A strong electrostatic interaction occurs between BR-5 and PAHs in asphaltenes. Thus, BR-5 achieves the goal of aged asphalt binder regeneration by attracting PAHs., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Pavement Engineering

Sustainable and resilient pavement infrastructure is critical for current economic and environmental challenges. In the past 10 years, the pavement infrastructure strongly supports the rapid development of the global social economy. New theories, new methods, new technologies and new materials related to pavement engineering are emerging. Deterioration of pavement infrastructure is a typical multi-physics problem. Because of actual coupled behaviors of traffic and environmental conditions, predictions of pavement service life become more and more complicated and require a deep knowledge of pavement material analysis. In order to summarize the current and determine the future research of pavement engineering, Journal of Traffic and Transportation Engineering (English Edition) has launched a review paper on the topic of “New innovations in pavement materials and engineering: A review on pavement engineering research 2021”. Based on the joint-effort of 43 scholars from 24 well-known universities in highway engineering, this review paper systematically analyzes the research status and future development direction of 5 major fields of pavement engineering in the world. The content includes asphalt binder performance and modeling, mixture performance and modeling of pavement materials, multi-scale mechanics, green and sustainable pavement, and intelligent pavement. Overall, this review paper is able to provide references and insights for researchers and engineers in the field of pavement engineering., Pavement Engineering

Differences among climate models in equilibrium climate sensitivity (ECS; the equilibrium surface temperature response to a doubling of atmospheric CO2) remain a significant barrier to the accurate assessment of societally important impacts of climate change. Relationships between ECS and observable metrics of the current climate in model ensembles, so-called emergent constraints, have been used to constrain ECS. Here a statistical method (including a backward selection process) is employed to achieve a better statistical understanding of the connections between four recently proposed emergent constraint metrics and individual feedbacks influencing ECS. The relationship between each metric and ECS is largely attributable to a statistical connection with shortwave low cloud feedback, the leading cause of intermodel ECS spread. This result bolsters confidence in some of the metrics, which had assumed such a connection in the first place. Additional analysis is conducted with a few thousand artificial metrics that are randomly generated but are well correlated with ECS. The relationships between the contrived metrics and ECS can also be linked statistically to shortwave cloud feedback. Thus, any proposed or forthcoming ECS constraint based on the current generation of climate models should be viewed as a potential constraint on shortwave cloud feedback, and physical links with that feedback should be investigated to verify that the constraint is real. In addition, any proposed ECS constraint should not be taken at face value since other factors influencing ECS besides shortwave cloud feedback could be systematically biased in the models. © 2018 American Meteorological Society.

Asphalt pavement has been widely used in the world. As the main components of asphalt pavement, the asphalt binder is crucial to the service performance and life of the road. In the past decades, numerous studies were conducted on technical performance, aging, and modification of the asphalt binder. With the development of modern technology, it was discovered that the microscopic properties, aging mechanism, and modification mechanism of the asphalt binder affect the macroscopic performance of asphalt pavement significantly. As a new emerging powerful numerical tool, the molecular dynamics (MD) simulation has been developed to study the asphalt binder material from a micro perspective. Based on the previous studies, some average asphalt binder models, fractional asphalt binder models, aged asphalt binder models, and modifier models were proposed by many researchers, which have made remarkable progress in asphalt studies; the microproperties, aging mechanism, and modification mechanism of the asphalt binder can also be analyzed using the MD simulation. Overall, the state-of-the-art review provides a comprehensive view for the readers to better understand the development, establishment, and application of the asphalt molecular model.

Emergent constraints use relationships between future and current climate states to constrain projections of climate response. Here we introduce a statistical, hierarchical emergent constraint (HEC) framework in order to link future and current climates with observations. Under Gaussian assumptions, the mean and variance of the future state are shown analytically to be a function of the signal-to-noise ratio between current climate uncertainty and observation error and the correlation between future and current climate states. We apply the HEC to the climate change, snow-albedo feedback, which is related to the seasonal cycle in the Northern Hemisphere. We obtain a snow-albedo feedback prediction interval of (−1.25,−0.58)%/K. The critical dependence on signal-to-noise ratio and correlation shows that neglecting these terms can lead to bias and underestimated uncertainty in constrained projections. The flexibility of using HEC under general assumptions throughout the Earth system is discussed.

Full Text, Thesis (PhD Doctorate), Doctor of Philosophy (PhD), Dept Account,Finance & Econ, Griffith Business School, The role of executive compensation contracts in providing managerial incentives is topical in academic research. Since the last decade, there have been intense debates over whether executive compensation is set optimally to align the interests of managers and those of shareholders. The significance of the global financial crisis (GFC) also sheds light on reviewing equity-based compensation granted to senior managers. The traditional perspective of equity awards holds that these equity mechanisms can attract and retain employees as well as encourage managerial effort exertion (Guay et al., 2002). However, more recently a large body of empirical studies expresses concern about the efficiency of these incentive contracts by arguing compensation may represent agency problems (Bebchuk, 2009). Since the real problem in the research for incentive compensation is ‘not how much you pay, but how’ (Jensen and Murphy, 2010), the primary focus of this study is how to design chief executive officer (CEO) equity-based compensation that can strengthen managerial incentives for making rationality-based corporate decisions. In particular, the corporate decisions considered in this study are investment decisions. Investment decisions of a firm should be independent of its financial situation (Jensen, 1986). However, the sensitivity of investment to cash flow indicates an agency problem of free cash flow. The efficiency of investment is a cause for concern because inefficient investments affect firm performance, leading to a reduction of firm value and economic growth. Within the agency framework, shareholders must find ways to alleviate investment-related agency problems that may result from deviations of firm investments from their optimal level. While there is prior evidence in the literature that corporate governance can influence managerial investment decisions, the evidence is less clear on the impact of specific design features of executive compensation on investment efficiency.

Detection of circulating tumor DNA using droplet digital polymerase chain reaction (ddPCR) is a highly-sensitive, minimally invasive alternative to serial biopsies for assessment and management of cancer. We used ddPCR to assess the utility of measuring plasma concentrations of common epidermal growth factor receptor (EGFR) mutations (L858R, exon 19 deletion, and T790M) in 57 non-small cell lung cancer (NSCLC) patients treated with EGFR tyrosine kinase inhibitors (EGFR-TKIs). High baseline plasma EGFR mutation (pEGFRmut) concentrations were associated with shorter progression-free survival (8.43 months) than low baseline pEGFRmut (16.23 months; p = 0.0019). By contrast, there were no differences in tumor shrinkage or overall survival between groups. During EGFR-TKI treatment, pEGFRmut levels decreased to zero in 89.58% of patients. Twenty-five of the 27 patients who progressed had basal pEGFRmut, and 18 also had circulating T790M. All 20 patients with dramatic progression (according to a categorization system for EGFR-TKIs failure) had basal pEGFRmut, and 13 had T790M mutation at progression. These results support the use of ddPCR for analysis of plasma EGFR mutations for prediction of PFS and to monitor clinical responses to EGFR-TKIs in NSCLC patients.

The present study aimed to determine the diagnostic concordance of plasma epidermal growth factor receptor (EGFR) mutation using droplet digital polymerase chain reaction (ddPCR) with tumor tissue samples and the predictive clinical significance of plasma EGFR mutation concentration. Plasma DNA samples from patients with non-small cell lung cancer (NSCLC) were analyzed for EGFR exon 21 codon 858 (L858R) mutation, deletion of exon 19 (ex19del) and exon 20 codon 790 (T790M) mutation using ddPCR. Firstly, the mutations in the plasma samples were compared with the matched tumor samples to determine the concordance. Secondly, image examination follow-ups were analyzed to assess the association between plasma EGFR mutation concentration and patients' response to EGFR-tyrosine kinase inhibitors (TKIs). A total of 51 patients with NSCLC were enrolled, including 48 newly diagnosed patients. Compared with tumor tissue samples, the sensitivity and specificity of ddPCR were 76.19% (16/21) and 96.55% (28/29) for mutant L858R, and 88.89% (8/9) and 100% (41/41) for ex19del, respectively. No patient exhibited the T790M mutation in the tumor tissue or plasma samples. Furthermore, 5 patients with the L858R mutation and 4 patients with ex19del in plasma and tumor tissue samples had been followed up with image examination for ≥3 months following EGFR-TKI treatment. The baseline mutant EGFR concentrations were positively correlated with a reduction in tumor burden (Spearman's r=0.7000, P=0.0358). When analyzed separately, ex19del concentrations (Spearman's r=1.0000, P<0.0001) were also positively correlated with the reduction, while mutant L858R concentrations were not (Spearman's r=0.7000, P=0.1881). In the present study, detection of plasma EGFR mutations using ddPCR exhibited sufficient concordance with tumor tissue sample results. Baseline plasma mutant EGFR and ex19del concentrations were significantly and positively correlated with response to EGFR-TKIs.

The role of executive compensation contracts in providing managerial incentives is topical in academic research. Since the last decade, there have been intense debates over whether executive compensation is set optimally to align the interests of managers and those of shareholders. The significance of the global financial crisis (GFC) also sheds light on reviewing equity-based compensation granted to senior managers. The traditional perspective of equity awards holds that these equity mechanisms can attract and retain employees as well as encourage managerial effort exertion (Guay et al., 2002). However, more recently a large body of empirical studies expresses concern about the efficiency of these incentive contracts by arguing compensation may represent agency problems (Bebchuk, 2009). Since the real problem in the research for incentive compensation is ‘not how much you pay, but how’ (Jensen and Murphy, 2010), the primary focus of this study is how to design chief executive officer (CEO) equity-based compensation that can strengthen managerial incentives for making rationality-based corporate decisions. In particular, the corporate decisions considered in this study are investment decisions. Investment decisions of a firm should be independent of its financial situation (Jensen, 1986). However, the sensitivity of investment to cash flow indicates an agency problem of free cash flow. The efficiency of investment is a cause for concern because inefficient investments affect firm performance, leading to a reduction of firm value and economic growth. Within the agency framework, shareholders must find ways to alleviate investment-related agency problems that may result from deviations of firm investments from their optimal level. While there is prior evidence in the literature that corporate governance can influence managerial investment decisions, the evidence is less clear on the impact of specific design features of executive compensation on investment efficiency., Thesis (PhD Doctorate), Doctor of Philosophy (PhD), Dept Account,Finance & Econ, Griffith Business School, Full Text

Recent research shows that macro-scale cracking in asphalt binder may originate from its intrinsic defects at the nano-scale. In this paper, a molecular dynamics (MD) simulation was conducted to evaluate the nucleation of natural defects in asphalt. The asphalt microstructure was modeled using an ensemble of three different types of molecules to represent a constituent species: asphaltenes, naphthene aromatics and saturates, where the weight proportion of 20:60:20 was used to create an asphalt-like ensemble of molecules. Tension force was then applied on the molecular boundaries to study the crack initiation and propagation. It was discovered that the natural distribution of atoms at microscale would affect the intrinsic defects in asphalt and further influence crack initiation and propagation in asphalt.

The functional maturation and preservation of hepatic cells derived from human induced pluripotent stem cells (hiPSCs) are essential to personalized in vitro drug screening and disease study. Major liver functions are tightly linked to the 3D assembly of hepatocytes, with the supporting cell types from both endodermal and mesodermal origins in a hexagonal lobule unit. Although there are many reports on functional 2D cell differentiation, few studies have demonstrated the in vitro maturation of hiPSC-derived hepatic progenitor cells (hiPSC-HPCs) in a 3D environment that depicts the physiologically relevant cell combination and microarchitecture. The application of rapid, digital 3D bioprinting to tissue engineering has allowed 3D patterning of multiple cell types in a predefined biomimetic manner. Here we present a 3D hydrogel-based triculture model that embeds hiPSC-HPCs with human umbilical vein endothelial cells and adipose-derived stem cells in a microscale hexagonal architecture. In comparison with 2D monolayer culture and a 3D HPC-only model, our 3D triculture model shows both phenotypic and functional enhancements in the hiPSC-HPCs over weeks of in vitro culture. Specifically, we find improved morphological organization, higher liver-specific gene expression levels, increased metabolic product secretion, and enhanced cytochrome P450 induction. The application of bioprinting technology in tissue engineering enables the development of a 3D biomimetic liver model that recapitulates the native liver module architecture and could be used for various applications such as early drug screening and disease modeling.

In this work, an approach for copper atomic layer deposition (ALD) via reduction of CuxO films was investigated regarding applications in ULSI interconnects, like Cu seed layers directly grown on diffusion barriers (e. g. TaN) or possible liner materials (e. g. Ru or Ni) as well as non-ferromagnetic spacer layers between ferromagnetic films in GMR sensor elements, like Ni or Co. The thermal CuxO ALD process is based on the Cu (I) β-diketonate precursor [(nBu3P)2Cu(acac)] and a mixture of water vapor and oxygen ("wet O2") as co-reactant at temperatures between 100 and 130 °C. Highly efficient conversions of the CuxO to metallic Cu films are realized by a vapor phase treatment with formic acid (HCOOH), especially on Ru substrates. Electrochemical deposition (ECD) experiments on Cu ALD seed / Ru liner stacks in typical interconnect patterns are showing nearly perfectly filling behavior. For improving the HCOOH reduction on arbitrary substrates, a catalytic amount of Ru was successful introduced into the CuxO films during the ALD with a precursor mixture of the Cu (I) β-diketonate and an organometallic Ru precursor. Furthermore, molecular and atomic hydrogen were studied as promising alternative reducing agents.

Using a combination of dynamical and statistical downscaling techniques, we projected mid-21stcentury warming in the Los Angeles region at 2-km (1.2-mile) resolution. To account for uncertainty associated with the trajectory of future greenhouse gas emissions and other factors affecting the planet's energy balance, we examined projections for both "business-as-usual" (RCP8.5) and "mitigation" (RCP2.6) emissions scenarios of the Fifth Coupled Model Intercomparison Project. To account for the considerable uncertainty associated with choice of global climate model, we downscaled results for all available global models. For the business-as-usual scenario, we find that by the mid-21stcentury, the most likely warming is roughly 4.6°F averaged over the region's land areas, with a 95% confidence that the warming lies between 1.7 and 7.5°F. The high resolution of the projections reveals a pronounced spatial pattern in the warming: High elevations and inland areas separated from the coast by at least one mountain complex warm 20 to 50% more than the areas near the coast or within the Los Angeles basin. This warming pattern is especially apparent in summertime. The summertime warming contrast between the inland and coastal zones has a large effect on the most likely expected number of extremely hot days per year. Coastal locations and areas within the Los Angeles basin see roughly two to three times the number of extremely hot days, while high elevations and inland areas typically experience approximately three to five times the number of extremely hot days. Under the mitigation emissions scenario, the most likely warming and increase in heat extremes are somewhat smaller. However, the majority of the warming seen in the business-as-usual scenario still occurs at all locations in the most likely case under the mitigation scenario, and heat extremes still increase significantly. Therefore adaptation to a changing climate over the next few decades is likely to be inevitable in t

Wireless Sensor Networks (WSNs) are highly integrated technologies applying sensor technology, micro-electro-mechanical systems (MEMS) and wireless networks technologies. They are widely used in many applications to acquire and process information. Many routing protocols are proposed for controlling the networks. The main problem, which the WSN protocols face, is that the sensors’ limited batter energy. Then the protocols have to be energy efficient to prolong the networks lifetime. Nowadays, there are several routing protocols which are designed to prolong the network life. Low Energy Adaptive Clustering Hierarchy (LEACH) is an outstanding and commonly used protocol designed for this purpose. To be energy efficient, the protocol applies cluster organization on the networks. It divides the sensor nodes into several clusters, and sends fusion cluster data through a cluster head, which is a representative node of one region. In this thesis, we propose the method which improves the LEACH algorithm. The proposed method firstly defines the fix round time. During the fixed round time, if a cluster head indicates lower energy level than the defined threshold, the cluster head will be transferred to another cluster member owning largest energy, and then the new cluster head continues to work until the round time is end. Therefore, the method avoids the unnecessary re-clustering of the whole network. Simulation results show that the proposed method performs better on prolonging the lifetime of a network than LEACH. In a random distribution, the proposed method prolongs the lifetime of the network almost more 20% rounds than LEACH does. While in an unbalanced distribution, the proposed performs much better, prolonging about 33% in our simulation., 0046-764 472 120

In countries Japan, Netherlands, and Singapore they experience increasing land scarcity due to concentration of population or flooding issue. The growing concerns over environmental degration and political conflicts due to land reclamation means land-filled is no longer an acceptable way. Thus these countries put greater emphasis on investigating and application of other alternatives, such as floating structure, to allow for urban expansion. In particular, Very Large Floating Structure (VLFS) is becoming increasing popular and promising. This thesis presents a range of water-based development that include urban and architectural scale, historical and recent, and focuses on analysing the urban aspects. Projects of Japan, Netherlands and Singapore are researched at lesser detail for understanding technical, economy and political considerations in a floating development. The purpose of this thesis is to investigate the possibilities of having floating structure as a way to expand the city. The case study used is of VLFS on the Lambton Harbour of Wellington city, New Zealand, to demonstrate the feasibility.

The deposition of Cu seed layers for electrochemical Cu deposition (ECD) via atomic layer deposition (ALD) of copper oxide and subsequent thermal reduction at temperatures between 110 and 120°C was studied on different diffusion barrier systems. While optimization of the process is required on TaN with respect to reduction and plating, promising results were obtained on blanket PVD Ru. The plating results on layers of ALD Cu with underlying Ru even outperformed the ones achieved on PVD Cu seed layers with respect to morphology and resistivity. Applying the processes to via and line patterns gave similar results, suggesting that a combination of ALD Cu with PVD or ALD-grown Ru could significantly improve the ECD Cu growth.

We show that intermodel variations in the anthropogenically-forced evolution of September sea ice extent (SSIE) in the Arctic stem mainly from two factors: the baseline climatological sea ice thickness (SIT) distribution, and the local climate feedback parameter. The roles of these two factors evolve over the course of the twenty-first century. The SIT distribution is the most important factor in current trends and those of coming decades, accounting for roughly half the intermodel variations in SSIE trends. Then, its role progressively decreases, so that around the middle of the twenty-first century the local climate feedback parameter becomes the dominant factor. Through this analysis, we identify the investments in improved simulation of Arctic climate necessary to reduce uncertainties both in projections of sea ice loss over the coming decades and in the ultimate fate of the ice pack.

We report a novel nanoprocess to fabricate 2D metallic and non-metallic nanophotonic crystals on SU-8 using hot embossing combining with a UV-curing process. The fabricated photonic crystals were characterized by optical diffraction experiments. Theoretical simulation of the light diffraction through such kind of artificial crystals agrees with the measured optical property very well, indicating that the developed fabrication technique is able to produce large area nanosize photonic crystals at economic costs. The success of this work not only provides scientists with a good opportunity to pioneer novel photonic physics in metallic and non-metallic chiral as well as photonic crystal systems, but also bridges the gap between laboratory and industrial application for mass production of photonic nanostructures.

This thesis develops semi-automated methods to generate testbenches for VHDL models of communication systems. To illustrate the methods, a VHDL model was constructed for the speech-coding channel of the Global System for Mobile Communication (GSM). GSM is the Pan-European digital mobile telephony standard specified by the European Telecommunication Standards Institute (ETSI). This thesis emphasizes the error detection and error correction procedures that form an important part of the standard. First, a test bench template was generated using "Testbench Pro", a waveform generation tool developed by SynaptiCAD. The template includes a random sequence of speech data. A C program was then developed as a user interface to control the simulation procedure. Using the C program, the user can select a test bench template and specify the input test vectors. The C program adds the user's test vectors to the test bench template to create a final VHDL test bench that is ready for simulation. The testing data is then encoded by the GSM encoder models, passed through the noisy channel model that introduces errors into the data stream and, finally, passed through the GSM decoder models which attempt to correct the channel errors. Sophisticated error detection and error correction algorithms are used in the encoder/decoder models to increase the reliability of data transmission over the noisy channel. Finally, the original speech data is compared to the decoder output to detect any remaining bit errors and to evaluate the system performance. The simulation system is semi-automated. The user selects a set of parameters using the C program interface. A testbench is then automatically created and simulated. Two final report files are automatically generated. No user interaction is needed after the initial parameter selection. Several experiments were performed to illustrate the various features of the automated testbench generation system.

NR 20140805