ETRI JournalPub Date : 2024-10-12DOI: 10.4218/etrij.2023-0484
Bo-Guen Kim, Sung-Man Kim
{"title":"Performance improvement of microLED-to-microLED visible light communication using reverse bias","authors":"Bo-Guen Kim, Sung-Man Kim","doi":"10.4218/etrij.2023-0484","DOIUrl":"https://doi.org/10.4218/etrij.2023-0484","url":null,"abstract":"<p>LED-to-LED visible light communication (VLC), which uses LEDs not only for the transmitter but also for the receiver, is being studied as an efficient optical wireless communication technology that uses LED lighting infrastructure. In this paper, we investigate microLED-to-LED VLC, which uses microLEDs as both the transmitter and receiver. In particular, we conducted a study to improve the performance of microLED-to-microLED VLC. For this, we measured the performance depending on the transmitter and receiver LED color combination. In addition, the effects of zero bias and reverse bias at the receiver LED were investigated. We also investigated the improvement in the reverse bias when applying a transimpedance amplifier to the receiver LED. Finally, we experimentally demonstrated a data rate of 360 kbps in the microLED-to-microLED VLC.</p>","PeriodicalId":11901,"journal":{"name":"ETRI Journal","volume":"47 2","pages":"270-277"},"PeriodicalIF":1.3,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.4218/etrij.2023-0484","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143835982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ETRI JournalPub Date : 2024-10-12DOI: 10.4218/etrij.2024-0120
Kwang-Il Oh, Hyuk Kim, Taewook Kang, Sung-Eun Kim, Jae-Jin Lee, Byung-Do Yang
{"title":"Mixed-mode SNN crossbar array with embedded dummy switch and mid-node pre-charge scheme","authors":"Kwang-Il Oh, Hyuk Kim, Taewook Kang, Sung-Eun Kim, Jae-Jin Lee, Byung-Do Yang","doi":"10.4218/etrij.2024-0120","DOIUrl":"https://doi.org/10.4218/etrij.2024-0120","url":null,"abstract":"<p>This paper presents a membrane computation error-minimized mixed-mode spiking neural network (SNN) crossbar array. Our approach involves implementing an embedded dummy switch scheme and a mid-node pre-charge scheme to construct a high-precision current-mode synapse. We effectively suppressed charge sharing between membrane capacitors and the parasitic capacitance of synapses that results in membrane computation error. A 400 × 20 SNN crossbar prototype chip is fabricated via a 28-nm FDSOI CMOS process, and 20 MNIST patterns with their sizes reduced to 20 × 20 pixels are successfully recognized under 411 μW of power consumed. Moreover, the peak-to-peak deviation of the normalized output spike count measured from the 21 fabricated SNN prototype chips is within 16.5% from the ideal value, including sample-wise random variations.</p>","PeriodicalId":11901,"journal":{"name":"ETRI Journal","volume":"46 5","pages":"865-877"},"PeriodicalIF":1.3,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.4218/etrij.2024-0120","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142524644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ETRI JournalPub Date : 2024-10-03DOI: 10.4218/etrij.2024-0153
Soohyun Park, Joongheon Kim
{"title":"Trends in quantum reinforcement learning: State-of-the-arts and the road ahead","authors":"Soohyun Park, Joongheon Kim","doi":"10.4218/etrij.2024-0153","DOIUrl":"https://doi.org/10.4218/etrij.2024-0153","url":null,"abstract":"<p>This paper presents the basic quantum reinforcement learning theory and its applications to various engineering problems. With the advances in quantum computing and deep learning technologies, various research works have focused on quantum deep learning and quantum machine learning. In this paper, quantum neural network (QNN)-based reinforcement learning (RL) models are discussed and introduced. Moreover, the pros of the QNN-based RL algorithms and models, such as fast training, high scalability, and efficient learning parameter utilization, are presented along with various research results. In addition, one of the well-known multi-agent extensions of QNN-based RL models, the quantum centralized-critic and multiple-actor network, is also discussed and its applications to multi-agent cooperation and coordination are introduced. Finally, the applications and future research directions are introduced and discussed in terms of federated learning, split learning, autonomous control, and quantum deep learning software testing.</p>","PeriodicalId":11901,"journal":{"name":"ETRI Journal","volume":"46 5","pages":"748-758"},"PeriodicalIF":1.3,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.4218/etrij.2024-0153","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142524655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ETRI JournalPub Date : 2024-09-30DOI: 10.4218/etrij.2023-0338
Dong-sheng Xu, Li-tian Wang, Li-rong Qian, Cui-ping Li, Ya-hui Tian, Hong-lang Li, Xuan Chen, Yu-qi Li
{"title":"A compact dual-band bandpass filter based on coupled stub-loaded square ring resonators by using transversal signal-interaction concepts","authors":"Dong-sheng Xu, Li-tian Wang, Li-rong Qian, Cui-ping Li, Ya-hui Tian, Hong-lang Li, Xuan Chen, Yu-qi Li","doi":"10.4218/etrij.2023-0338","DOIUrl":"https://doi.org/10.4218/etrij.2023-0338","url":null,"abstract":"<p>In this paper, a novel dual-band wideband bandpass filter (BPF) based on transversal signal-interaction concepts with a wide upper stopband is proposed and investigated. The designed specification of two passbands can be managed and satisfied based on the independent controllable fractional bandwidth of the two passbands and the centered frequencies. The centered frequencies of dual-band BPF are, respectively, 0.79 GHz (ƒ<sub>1</sub>) and 1.24 GHz (ƒ<sub>2</sub>) with 3 dB fraction bandwidths of 26.54% and 11.3%. Two transmission paths consisting of coupled stub-loaded square ring resonators and anti-coupled shorted lines are used to realize signal cancellation of multiple transmission path signal transmission from Port 1 to Port 2. Eleven transmission zeros (TZs) modify harmonic suppression up to 10 ƒ<sub>1</sub> with stopband rejection higher than 15 dB. Butterworth lumped notch network and step impedance resonator (SIR) are also utilized to improve the selectivity and harmonic suppression. A compact filter with a circuit size of 0.08<i>λ</i>g × 0.08<i>λ</i>g is implemented and tested. Good agreement between simulation and measured results verifies the reliability of the designing scheme.</p>","PeriodicalId":11901,"journal":{"name":"ETRI Journal","volume":"46 6","pages":"1113-1124"},"PeriodicalIF":1.3,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.4218/etrij.2023-0338","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142862320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ETRI JournalPub Date : 2024-09-30DOI: 10.4218/etrij.2023-0395
Harisu Abdullahi Shehu, Ibrahim Furkan Ince, Faruk Bulut
{"title":"Enhancement of eye socket recognition performance using inverse histogram fusion images and the Gabor transform","authors":"Harisu Abdullahi Shehu, Ibrahim Furkan Ince, Faruk Bulut","doi":"10.4218/etrij.2023-0395","DOIUrl":"https://doi.org/10.4218/etrij.2023-0395","url":null,"abstract":"<p>The eye socket is a cavity in the skull that encloses the eyeball and its surrounding muscles. It has unique shapes in individuals. This study proposes a new recognition method that relies on the eye socket shape and region. This method involves the utilization of an inverse histogram fusion image to generate Gabor features from the identified eye socket regions. These Gabor features are subsequently transformed into Gabor images and employed for recognition by utilizing both traditional methods and deep-learning models. Four distinct benchmark datasets (Flickr30, BioID, Masked AT & T, and CK+) were used to evaluate the method's performance. These datasets encompass a range of perspectives, including variations in eye shape, covering, and angles. Experimental results and comparative studies indicate that the proposed method achieved a significantly (\u0000<span></span><math>\u0000 <mi>p</mi>\u0000 <mo><</mo>\u0000 <mn>0.001</mn></math>) higher accuracy (average value greater than 92.18%) than that of the relevant identity recognition method and state-of-the-art deep networks (average value less than 78%). We conclude that this improved generalization has significant implications for advancing the methodologies employed for identity recognition.</p>","PeriodicalId":11901,"journal":{"name":"ETRI Journal","volume":"47 1","pages":"123-133"},"PeriodicalIF":1.3,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.4218/etrij.2023-0395","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143497166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ETRI JournalPub Date : 2024-09-30DOI: 10.4218/etrij.2023-0482
Dong Yun Jung, Kun Sik Park, Sang In Kim, Hyun Gyu Jang, Jongil Won, Yong Ha Lee, Jong-Won Lim
{"title":"Precharge switch based on metal–oxide–semiconductor-controlled thyristor for power relay assembly of battery electric vehicles","authors":"Dong Yun Jung, Kun Sik Park, Sang In Kim, Hyun Gyu Jang, Jongil Won, Yong Ha Lee, Jong-Won Lim","doi":"10.4218/etrij.2023-0482","DOIUrl":"https://doi.org/10.4218/etrij.2023-0482","url":null,"abstract":"<p>The power relay assembly (PRA) is an essential component to ensure the safety of an electric vehicle. We propose a semiconductor-based precharge switch to overcome the shortcomings of the conventional mechanical relay, which is currently used as the precharge switch in the PRA. The gate-driving circuit uses a photocoupler instead of a gate-driving integrated circuit to reduce complexity and cost. Five devices, namely, two insulated-gate bipolar transistors (IGBTs), two silicon carbide metal–oxide–semiconductor field-effect transistors (SiC MOSFETs), and one metal–oxide–semiconductor-controlled thyristor (MCT) are tested as candidate precharge switches. Each device is analyzed under varying battery voltage and fixed measurement conditions. The IGBT and SiC MOSFET burn below 600 V, while the MCT exhibits normal operation up to 800 V. The MCT precharge switch can solve shortcomings of the conventional mechanical relay and increase the performance with a simple gate-driving circuit. Furthermore, the PRA with an MCT precharge switch can reduce the volume, weight, and cost while improving reliability.</p>","PeriodicalId":11901,"journal":{"name":"ETRI Journal","volume":"47 2","pages":"326-337"},"PeriodicalIF":1.3,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.4218/etrij.2023-0482","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143836384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An enhanced companding algorithm for universal filtered multicarrier system","authors":"Vijaya Durga Chintala, Shri Ramtej Kondamuri, Subba Rao Suddapalli, Anuradha Sundru","doi":"10.4218/etrij.2023-0516","DOIUrl":"https://doi.org/10.4218/etrij.2023-0516","url":null,"abstract":"<p>This paper proposes a new companding scheme called three \u0000<span></span><math>\u0000 <mi>μ</mi></math>-law companding to reduce the peak-to-average power ratio (PAPR) in a universal filtered multicarrier system. The proposed scheme is more flexible and provides better PAPR reduction and bit error rate (BER) through the selection of the three companding parameters. However, the proposed scheme suffers from high side lobes and increases the power of the companded signal. Hence, an enhanced three \u0000<span></span><math>\u0000 <mi>μ</mi></math>-law, which overcomes these limitations, is proposed. Unlike the first scheme, the enhanced scheme does not change the mean power of the companding signal because it incorporates power-level normalization. Simulation results show that, compared with other companding transforms, the proposed enhanced three \u0000<span></span><math>\u0000 <mi>μ</mi></math>-law scheme offers better BER characteristics and side-lobe level suppression. It also provides better PAPR reduction of 7.4 dB and net gain of 6.3 dB. The proposed enhanced three \u0000<span></span><math>\u0000 <mi>μ</mi></math>-law was evaluated over a multipath fading channel and was more robust than other companding techniques. Finally, the proposed enhanced algorithm was verified in real time using the Wireless Open-Access Research Platform.</p>","PeriodicalId":11901,"journal":{"name":"ETRI Journal","volume":"47 2","pages":"244-255"},"PeriodicalIF":1.3,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.4218/etrij.2023-0516","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143836356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ETRI JournalPub Date : 2024-09-06DOI: 10.4218/etrij.2023-0445
Salifou Mounchili, Soumaya Hamouda
{"title":"Efficient joint power allocation for mitigating intracluster interference in clustered NOMA system","authors":"Salifou Mounchili, Soumaya Hamouda","doi":"10.4218/etrij.2023-0445","DOIUrl":"https://doi.org/10.4218/etrij.2023-0445","url":null,"abstract":"<p>In recent years, the growing demand for massive connectivity has focused researchers' attention on next-generation radio access techniques. Nonorthogonal multiple access (NOMA) is a candidate for supporting massive connectivity. However, NOMA systems generate severe intracluster interference, which affects user groups (clusters) with low channel gain differences because of user clustering and the low power disparity between users. Therefore, multiuser NOMA clustering and power management policies must be adopted. We propose schemes for multiuser clustering and joint power allocation. We analytically formulate power allocation for a given signal-to-interference-plus-noise ratio considering users in the cluster with different and similar locations (channel gains) in the cell. The formulation is then applied to NOMA clusters. Finally, we evaluate the optimal cluster size according to the number of users. The proposed schemes outperform other approaches in terms of total cluster throughput and user throughput with the highest channel gain.</p>","PeriodicalId":11901,"journal":{"name":"ETRI Journal","volume":"47 2","pages":"216-226"},"PeriodicalIF":1.3,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.4218/etrij.2023-0445","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143835848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ETRI JournalPub Date : 2024-08-19DOI: 10.4218/etrij.2023-0485
Khushboo Jha, Sumit Srivastava, Aruna Jain
{"title":"A novel speaker verification approach featuring multidomain acoustics based on the weighted city block Minkowski distance","authors":"Khushboo Jha, Sumit Srivastava, Aruna Jain","doi":"10.4218/etrij.2023-0485","DOIUrl":"https://doi.org/10.4218/etrij.2023-0485","url":null,"abstract":"<p>Access control is vital in interconnected environments like the Internet of Things, Industry 4.0, and smart connectivity, ensuring authorized access for security. Biometric-based access, particularly speaker verification (SV), enhances security with unique vocal features, offering nonintrusive authentication with continuous monitoring. Single-domain features prove insufficient in distinguishing similar traits, prompting latest SV advancements to adopt multidomain-based speech features. This paradigm addresses the limitations of single-domain features by amalgamating the merits of individual domains, establishing a cutting-edge approach. It utilizes cepstral–frequency–time domain feature fusion, achieved via cepstral mean-variance normalization for generalizability. The weighted city block Minkowski distance is proposed to compare reference and test speech templates. Parameters are computed based on the confusion matrix, template matching distance functions, dynamic acoustic conditions, and additive white Gaussian noise. A deep convolutional neural network classifier is assessed on open-source LibriSpeech and Speaker in the Wild corpora, surpassing the current methodologies.</p>","PeriodicalId":11901,"journal":{"name":"ETRI Journal","volume":"47 2","pages":"227-243"},"PeriodicalIF":1.3,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.4218/etrij.2023-0485","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143836357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Analyzing ASEP with imperfect-phase error and various modulation schemes on IRS-aided wireless network over κ–μ fading channel","authors":"Rajnish Kumar Ranjan, Atanu Chowdhury, Dibyendu Ghoshal","doi":"10.4218/etrij.2023-0383","DOIUrl":"https://doi.org/10.4218/etrij.2023-0383","url":null,"abstract":"<p>Next-generation wireless systems constitute a promising technology, and intelligent reflecting surface (IRS)-aided mobile communications can be used to design and simulate a smart and flexible radio environment. We examine the average symbol error probability (ASEP) on an IRS-aided wireless network over a <i>κ</i>–<i>μ</i> fading channel with imperfect phase error. In addition, the ASEP for non-coherent <i>M</i>-ary frequency shift keying, <i>M</i>-ary phase shift keying, and <i>M</i>-ary differential phase shift keying on an IRS-aided wireless network over a <i>κ</i>–<i>μ</i> fading channel are analyzed. Furthermore, exact closed-form mathematical expressions for ASEP across different modulation schemes including ASEP with imperfect phase error are derived. The accuracy of the derived expressions is validated through simulations. The system effectiveness is comprehensively examined, uncovering valuable insights into channel fading values and the number of reflecting components.</p>","PeriodicalId":11901,"journal":{"name":"ETRI Journal","volume":"47 1","pages":"59-68"},"PeriodicalIF":1.3,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.4218/etrij.2023-0383","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143497253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}