Minh Vu - Academia.edu (original) (raw)

Papers by Minh Vu

Academy of Management Proceedings, 2016

In this study, we examine how supervisor’s position in the formal organizational hierarchy (super... more In this study, we examine how supervisor’s position in the formal organizational hierarchy (supervisor job level) and in the informal network structure (supervisor advice network centrality) influe...

2021 IEEE Conference on Control Technology and Applications (CCTA), 2021

The ability to quickly synthesize an optimal control signal for a nonlinear system is critical fo... more The ability to quickly synthesize an optimal control signal for a nonlinear system is critical for practical implementations. In previous work, we have introduced a computational procedure to iteratively synthesize an optimal control signal for a very broad class of nonlinear control systems. This paper presents an extension of the approach to allow for different parameterizations of control inputs, resulting in a substantial reduction in the number of decision variables and thus computation time. The highlighted efficiency and effectiveness of the proposed approach are illustrated and compared against other methods using various control examples.

Cholesteatomas are benign lesions that form in the middle ear (ME). They can cause debilitating s... more Cholesteatomas are benign lesions that form in the middle ear (ME). They can cause debilitating side effects including hearing loss, recurrent ear infection and drainage, and balance disruption. The current approach for positively identifying cholesteatomas requires intraoperative visualization either by lifting the ear drum or transmitting an endoscope through the ear canal and tympanic membrane – procedures which are typically done in and operating room with the patient under general anesthesia. We are developing a novel endoscope that can be inserted trans-nasally and could potentially be used in an outpatient setting allowing clinicians to easily detect and visualize cholesteatomas and other middle ear conditions. A crucial part of designing this device is determining the degrees of freedom necessary to visualize the regions of interest in the middle ear space. To permit virtual evaluation of scope design, in this work we propose to create a library of models of the most difficu...

ICC 2020 - 2020 IEEE International Conference on Communications (ICC), 2020

Network protocols are challenging to test for correctness due to the huge number of packet dynami... more Network protocols are challenging to test for correctness due to the huge number of packet dynamics possibilities. Network simulators are popular in evaluating the performance of network protocols but unable to test the correctness under different packet dynamics efficiently. Random testing and symbolic execution are two effective automated correctness testing techniques that can explore different program execution possibilities. Random testing is simple and scalable in checking typical cases but often misses corner ones with low probabilities. Symbolic execution is more efficient in exploring these corner cases but suffers from the scalability problem. In this paper, we propose a testing platform built upon a network simulator by implementing a combination of symbolic execution and random testing to mitigate their limitations. Then we evaluate the efficiency of different techniques in testing Linux network stack under multiple possibilities of packet dynamics.

IACR Cryptol. ePrint Arch., 2020

Cryptographic protections are ubiquitous in information technology, including the emerging Intern... more Cryptographic protections are ubiquitous in information technology, including the emerging Internet of Things (IoT). As a result of technology migration to a resource-challenged landscape and new threats to cryptographic security, governments and industry are exploring new cryptographic algorithms. While new standards will emerge, however, old standards will not disappear for the time being. It is therefore important to explore platforms where multiple cryptographic deployments can be dynamically interchanged and even share resources. In this research we build on the Development Package for the Applications Programming Interface for Hardware Implementations of Lightweight Cryptography (DP API HW LWC). In this construct, developers design hardware implementations of authenticated encryption with associated data (AEAD) inside a cryptographic core (CryptoCore) encapsulated by input/output utilities. While CryptoCore is intended for single register-transfer level (RTL) implementations, ...

Proceedings of the Twenty-Eighth International Joint Conference on Artificial Intelligence, 2019

In this paper, we propose a novel Heterogeneous Gaussian Mechanism (HGM) to preserve differential... more In this paper, we propose a novel Heterogeneous Gaussian Mechanism (HGM) to preserve differential privacy in deep neural networks, with provable robustness against adversarial examples. We first relax the constraint of the privacy budget in the traditional Gaussian Mechanism from (0, 1] to (0, infty), with a new bound of the noise scale to preserve differential privacy. The noise in our mechanism can be arbitrarily redistributed, offering a distinctive ability to address the trade-off between model utility and privacy loss. To derive provable robustness, our HGM is applied to inject Gaussian noise into the first hidden layer. Then, a tighter robustness bound is proposed. Theoretical analysis and thorough evaluations show that our mechanism notably improves the robustness of differentially private deep neural networks, compared with baseline approaches, under a variety of model attacks.

ABSTRACTWe report the generation of a multimodal cell census and atlas of the mammalian primary m... more ABSTRACTWe report the generation of a multimodal cell census and atlas of the mammalian primary motor cortex (MOp or M1) as the initial product of the BRAIN Initiative Cell Census Network (BICCN). This was achieved by coordinated large-scale analyses of single-cell transcriptomes, chromatin accessibility, DNA methylomes, spatially resolved single-cell transcriptomes, morphological and electrophysiological properties, and cellular resolution input-output mapping, integrated through cross-modal computational analysis. Together, our results advance the collective knowledge and understanding of brain cell type organization: First, our study reveals a unified molecular genetic landscape of cortical cell types that congruently integrates their transcriptome, open chromatin and DNA methylation maps. Second, cross-species analysis achieves a unified taxonomy of transcriptomic types and their hierarchical organization that are conserved from mouse to marmoset and human. Third, cross-modal an...

2021 IEEE 41st International Conference on Distributed Computing Systems (ICDCS), 2021

Google introduced BBR representing a new model-based TCP class in 2016, which improves throughput... more Google introduced BBR representing a new model-based TCP class in 2016, which improves throughput and latency of Google's backbone and services and is now the second most popular TCP on the Internet. As BBR is designed as a general-purpose congestion control to replace current widely deployed congestion control such as Reno and CUBIC, this raises the importance of studying its performance in different types of networks. In this paper, we study BBR's performance in cloud networks, which have grown rapidly but have not been studied in the existing BBR works. For the first time, we show both analytically and experimentally that due to the virtual machine (VM) scheduling in cloud networks, BBR underestimates the pacing rate, delivery rate, and estimated bandwidth, which are three key elements of its control loop. This underestimation can exacerbate iteratively and exponentially over time, and can cause BBR's throughput to reduce to almost zero. We propose a BBR patch that captures the VM scheduling impact on BBR's model and improves its throughput in cloud networks. Our evaluation of the modified BBR on the testbed and EC2 shows a significant improvement in the throughput and bandwidth estimation accuracy over the original BBR in cloud networks with heavy VM scheduling.

2018 IEEE/ACM International Conference on Utility and Cloud Computing Companion (UCC Companion), 2018

Serverless computing platforms provide Function(s)-as-a-Service (FaaS) to end users while promisi... more Serverless computing platforms provide Function(s)-as-a-Service (FaaS) to end users while promising reduced hosting costs, high availability, fault tolerance, and dynamic elasticity for hosting individual functions known as microservices. Serverless Computing environments abstract infrastructure management including creation of virtual machines (VMs), containers, and load balancing from users. To conserve cloud server capacity and energy, cloud providers allow serverless computing infrastructure to go COLD, deprovisioning hosting infrastructure when demand falls, freeing capacity to be harnessed by others. In this paper, we present on a case study migration of the Precipitation Runoff Modeling System (PRMS), a Java-based environmental modeling application to the AWS Lambda serverless platform. We investigate performance and cost implications of memory reservation size, and evaluate scaling performance for increasing concurrent workloads. We then investigate the use of Keep-Alive workloads to preserve serverless infrastructure to minimize cold starts and ensure fast performance after idle periods for up to 100 concurrent client requests. We show how Keep-Alive workloads can be generated using cloud-based scheduled event triggers, enabling minimization of costs, to provide VM-like performance for applications hosted on serverless platforms for a fraction of the cost.

2020 American Control Conference (ACC), 2020

This paper presents computational solutions for nonlinear optimal control problems with general s... more This paper presents computational solutions for nonlinear optimal control problems with general state-space constraints that may not be representable in terms of analytical expressions. The presented approaches hinge on the iterative nature of an underlying computational nonlinear optimal control methodology by which the non-analytical constraint description can be incorporated as quadratic constraints within each iteration. The functionality and efficiency of the proposed methods are discussed from a computational point of view and illustrated on a standard parallel parking problem.

SummaryNeuronal cell types are classically defined by their molecular properties, anatomy, and fu... more SummaryNeuronal cell types are classically defined by their molecular properties, anatomy, and functions. While recent advances in single-cell genomics have led to high-resolution molecular characterization of cell type diversity in the brain, neuronal cell types are often studied out of the context of their anatomical properties. To better understand the relationship between molecular and anatomical features defining cortical neurons, we combined retrograde labeling with single-nucleus DNA methylation sequencing to link epigenomic properties of cell types to neuronal projections. We examined 11,827 single neocortical neurons from 63 cortico-cortical (CC) and cortico-subcortical long-distance projections. Our results revealed unique epigenetic signatures of projection neurons that correspond to their laminar and regional location and projection patterns. Based on their epigenomes, intra-telencephalic (IT) cells projecting to different cortical targets could be further distinguished,...

Canadian Journal of Cardiology, 2015

BACKGROUND: The IMPACT-CABG trial (NCT01033617) is a Canadian multicenter randomized, prospective... more BACKGROUND: The IMPACT-CABG trial (NCT01033617) is a Canadian multicenter randomized, prospective, doubleblinded study investigating the feasibility, safety and efficacy of intramyocardial injections of autologous CD133+ stem cells in patients with chronic ischemic cardiomyopathy and impaired LV dysfunction (LVEF 25-45%) undergoing isolated CABG surgery. The primary safety endpoint was freedom from major adverse cardiac event (MACE) at time of injection and 6 months follow-up, including freedom from cardiac death, myocardial infarction (MI), repeat revascularization or severe arrhythmias. The secondary efficacy endpoint was regional myocardial perfusion and function assessed by magnetic resonance imaging (MRI). Herein we are reporting the safety results. METHODS: After an initial 5 (Montreal) or 2 (Toronto) openlabel patients who received stem cells, patients were then randomized in a 1:1 (Toronto1⁄418) or 2:1 (Montreal1⁄415) ratio to receive either stem cells or placebo. All forty patients (20 each in Montreal and Toronto) with ischemic cardiomyopathy and clinical indications for CABG provided informed consent and were assessed with preoperative stress echo and perfusion MRI. All patients had 100-150 cc of bone marrow aspirated from the iliac crest under local anaesthesia and light sedation on the morning of surgery. Stem cells were isolated using the CliniMACS CD133+ Reagent System (Miltenyi Biotec), which utilizes superparamagnetic beads composed of iron-dextran particles conjugated to monoclonal antibodies. On the afternoon following cell preparation, patients underwent conventional CABG surgery under cardiopulmonary bypass. Following the completion of the distal coronary anastomoses, the cell preparation containing up to 10 million cells or placebo was injected (10-15 injection sites) into the infarct and border zone as identified by MRI. RESULTS: Patient demographics, intraoperative data and hospital outcomes are presented in Table 1 for all 40 patients. Stem cell isolation procedures yielded cell preparations meeting release criteria in all patients randomized to cell delivery. There was no in-hospital mortality. No patient had a perioperative MI, 4 had renal failure, one had a wound infection and one had a seizure. During the 6-month followup period, one patient died from a pulmonary embolus, and no other MACE. CONCLUSION: This work represents the first Canadian experience with CD133+ stem cells for the treatment of chronic ischemic cardiomyopathy. There were no protocol-related complications, demonstrating that same-day isolation and delivery of stem cells in conjunction with CABG is safe and feasible. Cell therapy may become a valuable adjunct treatment for myocardial repair in heart failure patients in whom conventional therapies for ventricular dysfunction are limited.

The Expedition, Apr 14, 2015

We observed the effect of water deficiency on the growth rate of wild-type and cer10 mutant Arabi... more We observed the effect of water deficiency on the growth rate of wild-type and cer10 mutant Arabidopsis thaliana plants. Replicates consisted of 20 total pots, 10 containing two 14-day-old wild-type seedlings each and 10 containing two 14-day-old cer10 mutant seedlings each. Five of each pot type were treated with 125 mL of water, and the other five received 50 mL when watered. Length of the longest rosette leaf for each plant was measured on days 1, 8, 13 and 19 and a two-way ANOVA was conducted on the growth rates between days 8 and 19. Our results indicate that reduced water availability decreases the growth rate of both the wild-type and cer10 mutant A. thaliana (p=0.007). Furthermore, the effect of water availability on the growth rate appeared to be not significantly different for both the wild-type and cer10 mutants (p=0.502). In addition, there is insufficient evidence to support that wild-type A. thaliana has a greater growth rate than the cer10 mutant variety (p=0.0831).

Handbook of Materials Failure Analysis with Case Studies from the Chemicals, Concrete and Power Industries, 2016

International Psychogeriatrics, 2015

ABSTRACTBackground:Depression is a common problem in long-term care (LTC) settings. We sought to ... more ABSTRACTBackground:Depression is a common problem in long-term care (LTC) settings. We sought to characterize depression symptom trajectories over six months among older residents, and to identify resident characteristics at baseline that predict symptom trajectory.Methods:This study was a secondary analysis of data from a six-month prospective, observational, and multi-site study. Severity of depressive symptoms was assessed with the 15-item Geriatric Depression Scale (GDS) at baseline and with up to six monthly follow-up assessments. Participants were 130 residents with a Mini-Mental State Examination score of 15 or more at baseline and of at least two of the six monthly follow-up assessments. Individual resident GDS trajectories were grouped using hierarchical clustering. The baseline predictors of a more severe trajectory were identified using the Proportional Odds Model.Results:Three clusters of depression symptom trajectory were found that described “lower,” “intermediate,” an...

Archives of gerontology and geriatrics

The objectives of this study were: (1) to describe the prevalence and 6-month incidence of observ... more The objectives of this study were: (1) to describe the prevalence and 6-month incidence of observer-rated depression in residents age 65 and over of long-term care (LTC) facilities; (2) to describe risk factors for depression, at baseline and over time. A multisite, prospective observational study was conducted in residents aged 65 and over of 7 LTC facilities. The Cornell Scale for Depression in Dementia (CSDD) was completed by nurses monthly for 6 months. We measured demographic, medical, and functional factors at baseline and monthly intervals, using data from research assessments, nurse interviews, and chart reviews. 274 residents were recruited and completed baseline depression assessments. The prevalence of depression (CSDD score of 6+) was 19.0%. The incidence of depression among those without prevalent depression was 73.3 per 100 person-years. A delirium diagnosis, pain, and diabetes were independently associated with prevalent depression. CSDD score at baseline and developm...

Ceramic Engineering and Science Proceedings, 2013

International Conference on Integration of Knowledge Intensive Multi-Agent Systems, 2005.

E2 is a plugin-based, service-oriented middleware architecture. E2 extends the popular Eclipse pl... more E2 is a plugin-based, service-oriented middleware architecture. E2 extends the popular Eclipse platform's idea of building a software system entirely and dynamically from XML-interfaced plugins, adds the feature to remove and replace plugins on the fly, administers the plugin connection process, and provides a message transport plugin for distributed inter-E2 system communication. E2 introduces a generic user interface plugin that separates user interfaces and application functionality. With these extensions, E2 extends the plugin concept, with its success on the desktop, to the broader areas of distributed middleware and multi-agent systems. E2 retains compatibility with Eclipse so that it can reuse Eclipse plugins but also, via an extensible interpreter capability, adds compatibility with Web Services and WSDL. This paper describes the E2 platform, implemented in Java, being used to develop the Everything is Alive agent system.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2011