• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.1
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• pp.73-83
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• 2013

In previous works, psychoacoustic parameters have been used for objective quantification. However, these parameters do not agree well with subjective assessment. Therefore, the correlation between psychoacoustic parameters and the subjective rating of door closing sounds of sampled cars is low, and it is not sufficient to use psychoacoustic parameters as an objective metric to quantify the sound quality of door closing sounds. In this paper, a new method is proposed to objectively quantify the sound quality based on physiological acoustics and statistical signal processing. The gammatone filter, as a pre-processing, is used in models of the auditory system and kurtosis, which is the fourth-order moment of temporal signal, and is used to extract information about sound quality quantification for door closing sounds. The new metric obtained through the proposed method is highly correlated with subjective rating, and it is successfully applied to the quantification of the sound quality of door closing sounds.

• Journal of the Korean Society for Railway
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• v.12 no.4
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• pp.450-456
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• 2009

In accordance with the development of recent computer technology, the dependency of railway signaling system on the computer software is being increased further, and accordingly, the testing for the safety and reliability of railway signaling system software became more important This thesis suggested automated an analysis tool for S/W metrics on this railway signaling system, and presented its result of implementation. The analysis items in the implemented tool had referred to the international standards in relation to the software for railway system, such as IEC61508 and IEC 62279. This automated analysis tool for railway signaling system can be utilized at the assessment stage for railway signaling system software also, and it is anticipated that it can be utilized usefully at the software development stage also.

• Journal of Information Processing Systems
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• v.13 no.4
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• pp.987-999
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• 2017

Extraction of influential people from their respective domains has attained the attention of scholastic community during current epoch. This study introduces an innovative interaction strength metric for retrieval of the most influential users in the online social network. The interactive strength is measured by three factors, namely re-tweet strength, commencing intensity and mentioning density. In this article, we design a novel algorithm called IPRank that considers the communications from perspectives of followers and followees in order to mine and rank the most influential people based on proposed interaction strength metric. We conducted extensive experiments to evaluate the strength and rank of each user in the micro-blog network. The comparative analysis validates that IPRank discovered high ranked people in terms of interaction strength. While the prior algorithm placed some low influenced people at high rank. The proposed model uncovers influential people due to inclusion of a novel interaction strength metric that improves results significantly in contrast with prior algorithm.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.10
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• pp.45-52
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• 2004

This Paper presents a modified hard decision Viterbi decoder with an error prediction circuit enhancing performance for the burst error inputs. Viterbi decoder employs the maximum likelihood decoding algorithm which shows excellent error correction capability for the random error inputs. Viterbi decoders, however, suffer poor error correction performance for the burst error inputs under the fading channel. The proposed error prediction algorithm increases error correction capability for the burst errors. The algorithm estimaties the burst error data area using the maximum path metric for the erroneous inputs, It calculates burst error intervals based on increases in the maximum values of a path metric. The proposed decoder keeps a performance the same as the conventional decoders on AWGN channels for the IEEE802.l1a WLAN system. It shows performance inproving 15% on the burst error of multi-path fading channels, widely used in mobile systems.

• Journal of the Korean Operations Research and Management Science Society
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• v.35 no.2
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• pp.53-69
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• 2010

This paper proposes an ant-based routing algorithm, Ant System-Routing in wireless Senor Networks(AS-RSN), for wireless sensor networks. Using a transition rule in Ant System, sensors can spread data traffic over the whole network to achieve energy balance, and consequently, maximize the lifetime of sensor networks. The transition rule advances one of the original Ant System by re-defining link cost which is a metric devised to consider energy-sufficiency as well as energy-efficiency. This metric gives rise to the design of the AS-RSN algorithm devised to balance the data traffic of sensor networks in a decentralized manner and consequently prolong the lifetime of the networks. Therefore, AS-RSN is scalable in the number of sensors and also robust to the variations in the dynamics of event generation. We demonstrate the effectiveness of the proposed algorithm by comparing three existing routing algorithms: Direct Communication Approach, Minimum Transmission Energy, and Self-Organized Routing and find that energy balance should be considered to extend lifetime of sensor network and increase robustness of sensor network for diverse event generation patterns.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.4
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• pp.330-340
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• 2002

In this Paper. a non-linear approach to a design of model reference adaptive control is presented. The approach is demonstrated by a case study of a simple single-pole and no zero, linear, discrete-time plant. The essence of the idea is to generate a full non-linear model of the plant dynamics and the parameter adaptation dynamics as a gradient descent algorithm with respect to a Riemannian metric. It is shown how a Riemannian metric can be chosen so that the modelled plant dynamics do in fact match the true plant dynamics. The performance of the proposed scheme is compared to a traditional model reference adaptive control scheme using the classical sensitivity derivatives (Euclidean gradients) for the descent algorithm.

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.01a
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• pp.105-108
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• 2012

Wireless mesh networks are considered a promising solution to last mile broadband. The unique characteristics of WMN impose unique requirements on designing routing protocols and metrics for WMN. However, existing routing schemes that are designed for single-channel multi-hop wireless networks may lead to inefficient routing paths in multichannel. This paper focuses on the routing problem for multi-radio multichannel WMNs. We list the challenges in designing routing algorithms for multi-radio multichannel WMNs. Then we examine the requirements and considerations for designing routing metrics according to the characteristics of multi-radio multichannel WMNs. Finally we survey and investigate the existing routing metrics in terms of their ability to satisfy these requirements.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1999.11b
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• pp.173-178
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• 1999

The Trellis Coded Modulation(TCM) allows the considerable achievements of coding gains compare with conventional multi-level modulation without compromising bandwidth efficiency. In this paper, we are presented a design of the parallel Viterbi decoder for 16-QAM TCM decoder with large constraint length (K=9), which can be applicable for the Digital Audio Broadcasting(DAB) receiver. As a mid-term result, a parallel Branch Metric Calculator (BMC)can compute 16 BMs within 3 clocks and a parallel 16 Add-Compare-Selects (ACS) unit can compute in a single clock. And also, two 256 Path Metric Memories (PMM) 32 Trace Back(TB) memories are specially designed with shuffle exchange switches for 16 parallel accesses. As a VHDL simulation, we can find the correctness of proposed model, which can be operated 16 S per symbol. Now, we are performing the hardware reduction for realtime operation and FPGA implementation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.2030-2036
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• 2016

This paper presents a hardware development procedure of the ASB(Active Seat Belt) control system to comply with ISO 26262. The ASIL(Automotive Safety Integrity Level) of an ASB system is determined through the HARA(Hazard Analysis and Risk Assessment) and the safety mechanism is applied to meet the reqired ASIL. The hardware architecture of the controller consists of a microcontroller, H-bridge circuits, passive components, and current sensors which are used for the input comparison. The required ASIL for the control systems is shown to be satisfied with the safety mechanism by calculation of the SPFM(Single Point Fault Metric) and the LFM(Latent Fault Metric) for the design circuits.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.418-420
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• 2013

Issues on design of routing scheme and routing metric for multicast in multi-channel multi-radio (MCMR) wireless mesh networks (WMNs) are discussed. Emphasis is placed on channel-diversity oriented routing metrics. From case study the conclusion to be drawn is that the key for design of channel-diversity oriented routing metrics is how to construct an optimization function to quantify interdependence between channel assignment and multicast routing throughput.