Learn About Me

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I am a Ph.D. candidate in computer science under the supervision of Prof. Bhaskar Krishnamachari, and I expect to graduate in May 2024. My research interests include machine learning, data-driven algorithms, anomaly detection, and edge computing. As a research assistant at the ANRG lab of USC, I work on developing and evaluating machine learning models for detecting and analyzing various attacks on IoT networks, such as DDoS and Sybil attacks. I have over four years of experience in this field, and I have published several papers in top-tier conferences and journals.


Previously, I was a software engineer intern at Google, where I worked on designing NLP/ML based systems to automatically generate ads and campaigns. I developed and integrated a prompt-engineered 24B LLM in production for generating search ads keywords tailored to advertisers' queries, resulting in high-quality and relevant keywords. I also designed and evaluated a prompt-engineered and fine-tuned 24B LLM on the ads help articles for addressing advertisers' general questions, achieving high relevance in addressing advertiser inquiries.


I am passionate about applying machine learning to solve real-world problems. I am always eager to learn new technologies and techniques, and to collaborate with other engineers and researchers. I am looking for opportunities to further advance my skills and knowledge, and to contribute to cutting-edge projects in these fields.



Education

  • PhD in Computer Science, University of Southern California, Los Angeles, California, USA
  • GPA (to date): 3.83/4.00
    Avdvisor: Prof. Bhaskar Krishnamachari
    Thesis: Innovative AI-based Methods in Cybersecurity and IoT:
    I have used innovative AI based methods for detecting anomalies and also designed data driven algorithms for making informed decisions.

    Aug. 2019 - Present
  • MASc in Electrical and Computer Engineering, McMaster University, Hamilton, Ontario, Canada
  • GPA: A (11.50/12.00)
    Avdvisors: Prof. Terry Todd, Prof. George Karakostas, Prof. Dongmei Zhao

    Thesis: Mobile Computation Offloading - Machine Learning:
    Developed an optimal computation offloading algorithm for a general Markovian communication channel. I have also worked on efficient offloading by using neural networks, Hidden Markov Models, reinforcement learning and other machine learning techniques.

    Sep. 2017- Jun. 2019
  • B.Sc. in Electrical and Computer Engineering, University of Tehran, Tehran, Iran
  • GPA : 16.88/20.00 (3.50/4.00)
    Except term 7 GPA : 17.63/20.00 (3.70/4.00)
    Avdvisor: Prof. Vahid Shah-Mansouri

    Thesis: Software Defined Networks:
    Developed multiple OpenDaylight controllers in software defined networks in order to control the TCP/UDP generated traffics in the network created by Mininet.

    Sep. 2013 - Jul. 2017
  • High School Diploma in Mathematics and Physics in Allameh Helli 1, Tehran, Iran
  • National Organization for Development of Exceptional Talents (NODET)
    GPA: 19.95/20.00 (4.00/4.00)
    Sep. 2009 - Jun. 2013

    Work Experience

  • Software Engineer Intern at Google, Mountain View, California, USA
  • May 2023 - Aug. 2023
    Team: Ads Conversational AI - Designing NLP/ML based systems to automatically generate Ads and campaigns:
    • Developed and integrated a prompt-engineered 24B LLM in production for generating search ads keywords tailored to advertisers' queries, resulting in ∼90% relevance and high-quality keywords suitable for production use.
    • Designed and evaluated a prompt-engineered and fine-tuned 24B LLM on the ads help articles for addressing advertisers' general questions; adopted the fine-tuned model, achieving ∼90% relevance in addressing advertiser inquiries.
  • Software Engineer Intern at Google, Mountain View, California, USA
  • May 2022 - Aug. 2022
    Team: Responsive Search Ads - Improving the quality of the automatically generated text ads.
    • Implemented workflows/dashboard for continuous evaluation of non-EN text ads quality.
    • Improved quality of automatically generated text ads through heuristic and ML modeling solutions:
    - Optimized title-based headline extractor filters, increasing the selection of high-quality headlines by ∼16%.
    - Improved mismatched language filter model accuracy by ∼93%, significantly reducing text ads rejections.
    - Implemented an ML workflow to aggregate and analyze data for enhancing the grammaticality model of non-EN text ads.
  • Software Engineer Intern, Farineh Fanavar, Tehran, Iran
  • Jun. 2016 - Sep. 2016
    I worked with Iotivity standard, one of the most important standards defined for the Internet of Things. At the first step, I used Iotivity to connect to different sensors for sending commands and also receiving data from them totally remotely over the internet. The other focus of my research was on sensor information processing in order to learn the users’ behavior.

    Research Experience

  • Research Assistant at ANRG, University of Southern California, Los Angeles, California, USA
  • 2019 - Present

    • Distributed Denial of Service (DDoS) Attack Analysis:
    - Synthesized and enhanced a real IoT time-series dataset with 350M samples, using real IoT network traffic distribution.
    - Developed tunable DDoS attacks on IoT nodes with different start times, duration, and traffic patterns.
    - Designed DDoS detection models using MLP, CNN, LSTM, AEN, and GCN with F1-score up to 91%
    - Designed and evaluated both prompt-engineered and fine-tuned GPT-3.5-turbo for DDoS detection reasoning.

    • Sybil Attack Analysis:
    - Preprocessed and feature engineered a mobile encounter dataset with more than 3M samples.
    - Designed Sybil attackers mimicking the behavior of real nodes using WGAN model
    - Developed a GCN-based detection model with 91% F1-score, outperforming traditional MLP models by 10%

    • Living Off The Land Binary (LOLBin) Malware Analysis:
    - Implemented FastText, BERT, RoBERTa, and SBERT embedding for Unix command representation.
    - Designed hybrid LOLBin detection/reasoning mechanism using LSTM/GPT-3.5-turbo with 94% F1-score

    • University Digital Twin (Gemini):
    - Created a unique students’ course registration dataset with more than 200K samples.
    - Modeled epidemic spread on a school campus and developed simulations to analyze the impact of different policies.
    - Designed and developed a greedy course scheduling algorithm, improved building entrance delay up to 3×.
    - Led a group of two students developing a real-time simulation web app dashboard

    • Administrating the ANRG Lab Linux servers
  • Research Assistant at Wireless Networking Lab, McMaster University, Hamilton, Ontario, Canada
  • Sep. 2017 - Jun. 2019

    Worked on Mobile Cloud Computing and Applied Machine Learning. Specifically, I’m working on Markov Chain, Markov Decision Process, Dynamic Programming, Machine Learning, Hidden Markov Model, Classification, Reinforcement Learning.
  • Research Assistant at Multimedia Wireless Networks Lab, University of Tehran, Tehran, Iran
  • Oct. 2016 - Jul. 2017

    Worked on software-defined networks (SDN). I used the Mininet network emulator to create a virtual SDN network for OpenDaylight (ODL) to control. I developed a topology which had several ODL controllers and could control the TCP/UDP traffic generated by the nodes in the network. I also worked on the Virtual Machines and tried to make a connection between them with a distributed virtual multilayer switch called “OpenVSwitch.”

    Publications

  • A. Hekmati, J. Zhang, T. Sarkar, N. Jethwa, E. Grippo, and B. Krishnamachari. “Correlation-Aware Neural Networks for DDoS Attack Detection In IoT Systems”. Submitted to IEEE/ACM Transactions on Networking - Under 2nd revision
  • X. Wang, Z. Wan, A. Hekmati, M. Zong, S. Alam, M. Zhang, and B. Krishnamachari. (2024). “IoT in the Era of Generative AI: Vision and Challenges”. arXiv preprint arXiv:2401.01923 - Submitted to IEEE Internet of Things Journal
  • A. Hekmati, and B. Krishnamachari. “Graph Convolutional Networks for DDoS Attack Detection in a Lossy Network” IEEE International Conference on Machine Learning for Communication and Networking (IEEE ICMLCN)
  • A. Hekmati, J. Zhang, T. Sarkar, and B. Krishnamachari. “Demo Abstract: CUDDoS - Correlation-aware Ubiquitous Detection of DDoS in IoT Systems.” 21th ACM Conference on Embedded Networked Sensor Systems (SenSys Demo)
  • M. Guastalla, Y. Li, A. Hekmati, and B. Krishnamachari. “Application of Large Language Models to DDoS Attack Detection” EAI International Conference on Security and Privacy in Cyber-Physical Systems and Smart Vehicles (SmartSP)
  • A. Hekmati. “PhD Forum: DDoS attack detection in IoT systems using Neural Networks.” Proceedings of the 22nd International Conference on Information Processing in Sensor Networks (PhD Forum)
  • A. Hekmati, M. Luhar, B. Krishnamachari and M. Mataric, “Simulating COVID-19 Classroom Transmission On A University Campus”, Proceedings of the National Academy of Sciences (PNAS), 119.22 (2022): e2116165119
  • A. Hekmati, E. Grippo, and B. Krishnamachari. “Neural Networks for DDoS Attack Detection using an Enhanced Urban IoT Dataset.” 2022 International Conference on Computer Communications and Networks (ICCCN) (pp. 1-8). IEEE
  • A. Hekmati, B. Krishnamachari and M. J. Mataric, “Course Scheduling to Minimize Student Wait Times For University Buildings During Epidemics,” 2021 IEEE International Conference on Big Data (Big Data), 2021, pp. 4365-4370, doi: 10.1109/BigData52589.2021.9671629
  • A. Hekmati, E. Grippo, and B. Krishnamachari. 2021. “Large-scale Urban IoT Activity Data for DDoS Attack Emulation”. In Proceedings of the 19th ACM Conference on Embedded Networked Sensor Systems (SenSys ’21). Association for Computing Machinery, New York, NY, USA, 560–564. DOI:https://doi.org/10.1145/3485730.3493695
  • A. Hekmati, M. Luhar, B. Krishnamachari and M. Mataric, “Simulation-Based Analysis of COVID-19 Spread Through Classroom Transmission on a University Campus,” 2021 IEEE International Conference on Communications Workshops (ICC Workshops), 2021, pp. 1-6, doi: 10.1109/ICCWorkshops50388.2021.9473803.
  • A. Hekmati, G. Ramachandran and B. Krishnamachari, “CONTAIN: Privacy-oriented Contact Tracing Protocols for Epidemics,” 2021 IFIP/IEEE International Symposium on Integrated Network Management (IM), 2021, pp. 872-877
  • A. Hekmati, P. Teymoori, T. Todd, D. Zhao, G. Karakostas, ”Optimal Mobile Computation Offloading With Hard Deadline Constraints”, Accepted for publication in IEEE Transactions on Mobile Computing
  • A. Hekmati, P. Teymoori, T. Todd, D. Zhao, G. Karakostas, ”Optimal Multi-Decision Mobile Computation Offloading With Hard Deadlines”, Accepted for publication in IEEE International Conference on Communications (ISCC)
  • Martin Martinez, A. Hekmati, Bhaskar Krishnamachari, Seokgu Yun, ”Mobile Encounter-based Social Sybil Control”, Accepted for publication in 2nd International Workshop on Blockchain Applications and Theory (BAT 2020), Paris, France, April 2020
  • A. Hekmati, Gowri Sankar Ramachandran, Bhaskar Krishnamachari, ”CONTAIN: Privacy-oriented Contact Tracing Protocols for Epidemics”, Submitted for publication in 13th ACM Conference on Security and Privacy in Wireless and Mobile Networks (ACM WiSec 2020), Linz, Austrua, July 2020

  • Certificates

  • Machine Learning by Stanford University on Coursera
  • Deep Learning Specialization on Coursera
  • Reinforcement Learning Specialization on Coursera
  • Generative Adversarial Networks (GANs) Specialization on Coursera.
  • DeepLearning.AI TensorFlow Developer Specialization on Coursera.

  • Honors and Awards

  • McMaster University MASc Fellowship and Scholarship
  • 2017-2019
  • University of Tehran MASc Fellowship Award as an exceptional talented student and exempt from taking the university entrance exam
  • 2017
  • Ranked 161 among more than 250000 participants (i.e. top 0.07%) in Iranian National University Entrance Exam
  • 2013

    Selected Course Projects

  • Geospatial Information Management
  • Developed K Nearest Neighbor, Continuous Nearest Neighbor, and Geo-Social Query Processing
  • Optical Character Recognition For Persian Alphabets
  • Developed neural network in Matlab to recognize Persian alphabets
  • Happy Face Detection
  • Implemented residual networks in Keras in order to detect the happy faces.
  • Car Detection in Autonomous Driving
  • Developed YOLO model in Keras.
  • Emojify
  • Developed word embedding and LSTM units in Keras for adding emojies to the sentences according to their meanings.
  • Trigger Word Detection
  • Developed 1-D convolutional layers, GRU layers, and dense layers in Keras.
  • Translate Dates
  • Developed Neural Machine Translation (NMT) model by using attention model.
  • LinkedIn
  • Design and implementation of an object oriented model of a social network like LinkedIn in C++
  • Secure File System
  • Design and Implementation of a Secure File System in C
  • Digital Modulations (PSK, FSK, ASK, QAM)
  • Implemented the simulation in Matlab

    Technical Skills

  • Programming:
  • Matlab, C, C++, Python
  • Deep Learning Frameworks:
  • TensorFlow, Keras
  • Operating Systems:
  • Linux, Windows
  • Document Preparation:
  • LATEX, Microsoft Office
  • Computer Networks:
  • Mininet, OpenDayLight, NS-2
  • Hardware Description Language (HDL):
  • Verilog, Modelsim, Quartus
  • Single Board Computers:
  • Raspberry Pi, BeagleBone
  • Microcontrollers:
  • AVR, ARM
  • Engineering Softwares:
  • Pspice, Hspice, Advanced Design System, Multisim, Labview, Proteus, Codevision

    Professional Activities

  • Served as a reviewer for International Wireless Communications and Mobile Computing Conference (IWCMC)
  • Helped as a volunteer student for Vehicular Technology Conference (VTC), Fall 2017

  • Teaching Experience

  • Introduction to Programming
  • Spring 2020
    Instructor : Prof. Andrew Goodney
  • Introduction to Programming
  • Fall 2019
    Instructor : Prof. Andrew Goodney
  • Advanced Internet Communication
  • Spring 2019
    Instructor : Prof. Terry Todd
  • Computer Communication Networks
  • Fall 2018
    Instructor : Prof. Terry Todd
  • Advanced Internet Communication
  • Spring 2018
    Instructor : Prof. Terry Todd
  • Computer Communication Networks
  • Fall 2017
    Instructor : Prof. Terry Todd
  • Computer Networks
  • Spring 2017
  • Engineering Probability and Statistics
  • Fall 2018
  • Electronics II
  • Fall 2016
  • Electromagnetics
  • Fall 2016
    Instructor : Prof. Leila Yousefi
  • Electromagnetics
  • Spring 2016
  • Electrical Circuits II
  • Spring 2016
  • Electronics I
  • Spring 2016
  • Physics I
  • Fall 2015
    Instructor : Prof. Nayereh Majd
  • Introduction to Computing Systems & Programming
  • Fall 2014

    Language Skills

  • Persian: Native
  • English: Fluent
  • TOEFL iBT(May. 2018): 110/120
  • Reading: 28/30, Listening: 29/30, Speaking: 24/30, Writing: 29/30
  • GRE (Nov. 2018) : 319/340
  • Verbal : 151/170, Quant: 168/170, Writing : 4.5/6.0

    Selected Courses

  • Machine Learning Courses:
  • Neural Networks and Learning Machines, Machine Learning, Deep Learning
  • Mathematics Courses:
  • Advanced Analysis of Algorithms, Analysis of Algorithms, Engineering Optimization, Engineering Probability and Statistics, Engineering Mathematics, Calculus I, II
  • Database Courses:
  • Geospatial Information Management
  • Programming Courses:
  • Advanced Programming, Introduction to Computing Systems & Programming
  • Networking Courses:
  • Cloud Communication, Wireless Communication Networks, Computer Networks, Digital Communication Laboratory

    Contact Me