• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.1
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• pp.80-90
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• 2016

Thanks to superior leakage energy efficiency compared to SRAM cells, STTRAM cells are considered as a promising alternative for a memory element in on-chip caches. However, the main disadvantage of STTRAM cells is high write energy and latency. In this paper, we propose a low-cost write filter (WF) cache which resides between the load/store queue and STTRAM-based L1 data cache. To maximize efficiency of the WF cache, the line allocation and access policies are optimized for reducing energy consumption of STTRAM-based L1 data cache. By efficiently filtering the write operations in the STTRAM-based L1 data cache, our proposed WF cache reduces energy consumption of the STTRAM-based L1 data cache by up to 43.0% compared to the case without the WF cache. In addition, thanks to the fast hit latency of the WF cache, it slightly improves performance by 0.2%.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.4
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• pp.227-233
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• 2016

Efficient finite field arithmetic is essential for fast implementation of error correcting codes and cryptographic applications. Among the arithmetic operations over finite fields, the multiplication is one of the basic arithmetic operations. Therefore an efficient design of a finite field multiplier is required. In this paper, two new bit-parallel systolic multipliers for $GF(2^m)$ fields defined by AOP(all-one polynomial) have proposed. The proposed multipliers have a little bit greater space complexity but save at least 22% area complexity and 13% area-time (AT) complexity as compared to the existing multipliers using AOP. As compared to related works, we have shown that our multipliers have lower area-time complexity, cell delay, and latency. So, we expect that our multipliers are well suited to VLSI implementation.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1987.05a
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• pp.7.3-8
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• 1987

청성뇌간 유발반응이 Juwett 및 Sohmer와 Feinmesser에 의하여 보고된 이래 타각적 청력검사로서 임상적응용에까지 이르렀다. 타각적 청력검사는 반응역치와 청각역치의 오차가 적어야 하며 주파수별로 역치측정이 가능하여야 하며 개인차가 적고 반응의 재현성이 높아야 되며 반응의 판정이 용이해야 함이 필요조건으로서 이러한 조건이 피검자의 수면상태하에서도 충족되어야 한다. 저자들은 정상 성인 청력자를 대상으로 sedation전후의 ABR에 대한 latency 및 amplitude를 중심으로 관찰하여 다음과 같은 결과를 얻었다. 1) Sedative의 사용에 있어서 amplitude및 latency의 차이는 없었다. 2) Sedative의 사용에는 무관하게 low frequency filter에서 high frequency filter보다 voltage의 유의한 차가 있었다.

• Journal of Semiconductor Engineering
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• v.1 no.2
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• pp.74-80
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• 2020

Due to its superior error correcting performance with affordable hardware complexity, the Polar code becomes one of the most important error correction codes (ECCs) and now intensively examined to check its applicability in various fields. However, Successive Cancellation (SC) decoding that brings the advanced Successive Cancellation List (SCL) decoding suffers from the long latency due to the nature of serial processing limiting the practical implementation. To mitigate this problem, many decoding architectures, mainly divided into pruning and parallel decoding, are presented in previous manuscripts. In this paper, we compare the recent SC decoding architectures and analyze them using a tree structure.

• IEMEK Journal of Embedded Systems and Applications
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• v.14 no.2
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• pp.71-78
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• 2019

As the capacity of SSDs rapidly increases, the amount of DRAM to keep a mapping table size in SSDs becomes very huge. To address a Demand-based FTL (DFTL) scheme that caches part of mapping entries in DRAM is considered to be a feasible alternative. However, owing to its unpredictable behaviors, DFTL fails to provide consistent I/O response times. In this paper, we a) analyze a root cause that results in fluctuation on read latency and b) propose a new demand-based FTL scheme that ensures guaranteed read response time with low write amplification. By preventing mapping evictions while serving reads, the proposed technique guarantees every host read requests to be done in 2 NAND read operations. Moreover, only with 25% of a cache ratio, the proposed scheme improves random write performance and random mixed performance by 1.65x and 1.15x, respectively, over the traditional DFTL.

• Journal of the Korea Society of Computer and Information
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• v.23 no.12
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• pp.73-80
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• 2018

Certification revocation list(CRL) is needed for excluding compromised, faulty, illegitimate vehicle nodes and preventing the use of compromised cryptographic materials in vehicular communications. It should be distributed to vehicles resource-efficiently and CRL computational load of vehicles should not impact on life-critical applications with delay sensitive nature such as the pre-crash sensing that affords under 50msec latency. However, in the existing scheme, when a vehicle receives CRL, the vehicle calculates linkage values from linkage seeds, which results in heavy computational load. This paper proposes, a new CRL distribution scheme is proposed, which minimizes the time for CRL processing of vehicles. In the proposed scheme, the linkage value calculation procedure is performed by road-side unit(RSU) instead of the vehicle, and then the extracted linkage values are relayed to the vehicle transparently. The simulation results show that the proposed scheme reduces the CRL computational load dramatically, which would minimize impact on life-critical applications' operations with low latency.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.8
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• pp.1113-1116
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• 2020

In the EH-WSN(Energy Harvesting Wireless Sensor Network), the routing protocol must consider the power condition of nodes such as residual power and energy harvesting rate. Many EH-WSN studies have emphasized the power aspect and make the urgency of sensed data less important. However, in applications such as environmental monitoring, stability and latency become more important issues than power efficiency for urgent data. In this paper, we designed a routing protocol that can set path according to data urgency. To this end, relay nodes are determined considering the urgency of date. Nodes with poor power do not participate in routing when normal data is generated, so that urgent data can be transmitted reliably with low latency. The performance of the proposed routing protocol is analyzed by computer simulation.

• Journal of information and communication convergence engineering
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• v.20 no.1
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• pp.8-15
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• 2022

The new 5G radio technology (NR) can provide ultra-reliable low latency communications. The supporting 5G network infrastructure will move away from the previous point-to-point network architecture to a service-based architecture. 5G can provide three new things, i.e., wider channels, lower latency and more bandwidth. These will allow 5G to support three main types of connected services, including enhanced mobile broadband, mission-critical communications, and the massive Internet of Things (IoT). In 2015, the 5th generation (5G) mobile communication was officially approved by the International Telecommunication Union (ITU) as IMT-2020. Since then, 3GPP, the international organization responsible for 5G standards, is actively developing specifications for 5G technologies. 3GPP Release 15 provides the first full set of 5G standards, and the evolution and expansion of 5G are now being standardized in Release 16 and 17, respectively. This paper provides an overview of 3GPP 5G technologies and key services.

• Journal of Software Assessment and Valuation
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• v.17 no.2
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• pp.19-29
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• 2021

Blockchain technology fulfills the reliance requirement and is now entering a new stage of performance. However, the current blockchain technology has significant disadvantages in scalability and latency because of its architecture. Therefore, to adopt blockchain technology to real industry, we must overcome the performance issue by redesigning blockchain architecture. This paper introduces several element technologies and a novel blockchain architecture TPAC, that preserves blockchain's technical advantage but shows more stable and faster transaction processing performance and low latency.

• ETRI Journal
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• v.44 no.6
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• pp.925-935
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• 2022

In this study, we propose a limited feedback-based frequency divided group beamforming with sparse space-frequency transmit diversity coded orthogonal frequency division multiplexing (OFDM) system for ultrareliable low latency communication (URLLC) scenario. The proposed scheme has several advantages over the traditional hybrid beamforming approach, including not requiring downlink channel state information for baseband precoding, supporting distributed multipoint transmission structures for diversity, and reducing beam sweeping latency with little uplink overhead. These are all positive aspects of physical layer characteristics intended for URLLC. It is suggested in the system to manage the multipoint transmission structure realized by distributed panels using a power allocation method based on cooperative game theory. Link-level simulations demonstrate that the proposed scheme offers reliability by achieving both higher diversity order and array gain in a nonline-of-sight channel of selectivity and limited spatial scattering.