ZELALEM JEMBRE YALEW

Dr. ZELALEM JEMBRE YALEW

Keimyung University
orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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3 March 2022 in Computational Intelligence and Neuroscience
Verified
Journal Article
Open access
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KZKamil Zeberga
Kamil Zeberga
MAMuhammad Attique
Muhammad Attique
BSBabar Shah
Babar Shah
FAFarman Ali
Farman Ali
ZYZELALEM JEMBRE YALEW
ZELALEM JEMBRE YALEW
Tae-Sun ChungTae-Sun Chung
Tae-Sun Chung
With the current advancement in the Internet, there has been a growing demand for building intelligent and smart systems that can efficiently address the detection of health-related problems on social media, such as the detection of depression and anxiety. These types of systems, which are mainly dependent on machine learning techniques, must be able to deal with obtaining the semantic and syntactic meaning of texts posted by users on social media. The data generated by users on social media contains unstructured and unpredictable content. Several systems based on machine learning and social media platforms have recently been introduced to identify health-related problems. However, the text representation and deep learning techniques employed provide only limited information and knowledge about the different texts posted by users. This is owing to a lack of long-term dependencies between each word in the entire text and a lack of proper exploitation of recent deep learning schemes. In this paper, we propose a novel framework to efficiently and effectively identify depression and anxiety-related posts while maintaining the contextual and semantic meaning of the words used in the whole corpus when applying bidirectional encoder representations from transformers (BERT). In addition, we propose a knowledge distillation technique, which is a recent technique for transferring knowledge from a large pretrained model (BERT) to a smaller model to boost performance and accuracy. We also devised our own data collection framework from Reddit and Twitter, which are the most common social media sites. Finally, we employed word2vec and BERT with Bi-LSTM to effectively analyze and detect depression and anxiety signs from social media posts. Our system surpasses other state-of-the-art methods and achieves an accuracy of 98% using the knowledge distillation technique.

6 August 2021 in Applied Sciences
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Journal Article
Open access
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ZYZELALEM JEMBRE YALEW
ZELALEM JEMBRE YALEW
YNYuniarto Wimbo Nugroho
Yuniarto Wimbo Nugroho
Muhammad Toaha Raza KhanMuhammad Toaha Raza Khan
Muhammad Toaha Raza Khan
MAMuhammad Attique
Muhammad Attique
RPRajib Paul
Rajib Paul
BKBeomjoon Kim
Beomjoon Kim
Unmanned Aerial Vehicles (UAVs) are abundantly becoming a part of society, which is a trend that is expected to grow even further. The quadrotor is one of the drone technologies that is applicable in many sectors and in both military and civilian activities, with some applications requiring autonomous flight. However, stability, path planning, and control remain significant challenges in autonomous quadrotor flights. Traditional control algorithms, such as proportional-integral-derivative (PID), have deficiencies, especially in tuning. Recently, machine learning has received great attention in flying UAVs to desired positions autonomously. In this work, we configure the quadrotor to fly autonomously by using agents (the machine learning schemes being used to fly the quadrotor autonomously) to learn about the virtual physical environment. The quadrotor will fly from an initial to a desired position. When the agent brings the quadrotor closer to the desired position, it is rewarded; otherwise, it is punished. Two reinforcement learning models, Q-learning and SARSA, and a deep learning deep Q-network network are used as agents. The simulation is conducted by integrating the robot operating system (ROS) and Gazebo, which allowed for the implementation of the learning algorithms and the physical environment, respectively. The result has shown that the Deep Q-network network with Adadelta optimizer is the best setting to fly the quadrotor from the initial to desired position.

8 February 2022 in Electronics
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Journal Article
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ZYZELALEM JEMBRE YALEW
ZELALEM JEMBRE YALEW
WJWoon-Young Jung
Woon-Young Jung
MAMuhammad Attique
Muhammad Attique
RPRajib Paul
Rajib Paul
BKBeomjoon Kim
Beomjoon Kim
Five decades have passed since the first bit was transmitted over the internet. Although the internet has improved our lives and led to the digital economy, currently only 51% of the world’s population have access to it. Currently, consumers mostly access the internet via mobile broadband, 2G, 3G, and 4G services. Regulatory bodies such as the Federal Communications Commission (FCC) of the US are responsible for ensuring that consumers receive an adequate service from Mobile Network Operators (MNOs). Usually, regulators evaluate the performance of each MNO in terms of service quality yearly and publish a report. To evaluate performance, metrics such as coverage, download/upload speed, and the number of subscribers can be used. However, the evaluation process and the metrics used by each regulatory body are inconsistent, and this makes it hard to determine which nations are providing adequate services to their citizens. Furthermore, it is not clear as to which performance evaluation is the right path. In this case study, we analyzed the reports released from eight nations (United States of America, United Kingdom, France, South Korea, Japan, Singapore, and Australia) as of the year 2020. We then point out the advantages and the drawbacks of the current evaluation process and metrics. Furthermore, a discussion on why the current methods are not sufficient to evaluate 5G services is presented. Our findings indicate that there is a great need for a unified metric and that this process becomes more complex with the rollout of 5G.

28 March 2024 in IEEE Transactions on Intelligent Transportation Systems
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Journal Article
Closed access
Muhammad Toaha Raza KhanMuhammad Toaha Raza Khan
Muhammad Toaha Raza Khan
ZYZELALEM JEMBRE YALEW
ZELALEM JEMBRE YALEW
MSMalik Muhammad Saad
Malik Muhammad Saad
Safdar Hussain BoukSafdar Hussain Bouk
Safdar Hussain Bouk
Syed Hassan AhmedSyed Hassan Ahmed
Syed Hassan Ahmed
Dongkyun KimDongkyun Kim
Dongkyun Kim
Content retrieval in content-centric vehicular networks faces challenges that include high latency, especially when content is stored far from the requesting vehicle. On-path caching feature in the conventional vehicular named data Networks (VNDN) enables content storage that can reduce latency. However, due to the constantly changing dynamic ad hoc nature of the vehicular network, the availability of stored content for the requester vehicle cannot be guaranteed. In addition, without knowing which content will be requested, where it will be requested and when it will be requested, the content caching functionality of VNDN is underutilized. To address this issue, this manuscript proposes a content prefetching scheme for the Content-centric Internet of Vehicles (CIoV) by introducing the content Value of Popularity ( $VoP$ ) matrix. Considering vehicles requesting content of similar interests, we evaluate $VoP$ through three value update functions that follow the power law of the time elapsed since the last content requested. By multiple parameters of consumer vehicle similarity, an on-road proactive content retriever vehicle is selected. The simulation results showed that the proposed proactive on-path content prefetching mechanism significantly reduces the content delivery delay while increasing the success delivery ratio by 48% and extends the spread of content within the network by 53%.

27 November 2018 in IEEE Access
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Journal Article
Open access
ZYZELALEM JEMBRE YALEW
ZELALEM JEMBRE YALEW
YCYoung-June Choi
Young-June Choi
At the start of each day we become more dependent on multi-hop wireless networks (MWNs) for establishing public safety, military or last mile Internet communication. The architecture of MWNs can be of flat such as ad-hoc or hierarchical such as mesh and sensor networks. These days, the reduction of cost and size in radios allows to fit multiple radios per devices. This means simultaneous transmissions on orthogonal channels, such that the performance of MWNs is multiplied. In MWNs, channel assignment (CA), which is handled at MAC layer, is responsible for creating a connected MWN, while avoiding congestion and interference. In addition, CA needs to handle jamming attacks. However, CA result in topology changes that in turn affect routing decisions. This strong interrelationship requires a cross-layered approach to create reliable connectivity. In this paper, we formulate this cross-layer problem as network-path cost optimization. Due to the NP-hardness of such problems, we proposed a distributed heuristic channel assignment and routing scheme which is applicable to both flat and hierarchical MWNs that is also resistant to jamming attacks. The distributed jamming resilient channel assignment and routing (DJ-CAR). We used OPNET to for simulation and compared the performance of the DJ-CAR with existing schemes.

12 September 2019 in Transactions on Emerging Telecommunications Technologies
Verified
Journal Article
Closed access
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ZYZELALEM JEMBRE YALEW
ZELALEM JEMBRE YALEW
SASyed Hassan Ahmed
Syed Hassan Ahmed
YCYoung‐June Choi
Young‐June Choi
JLJaime Lloret
Jaime Lloret