• The Journal of the Acoustical Society of Korea
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• v.39 no.4
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• pp.286-291
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• 2020

In this paper, we propose a system that recommends music through tempo-oriented music classification and sensor-based human activity recognition. The proposed method indexes music files using tempo-oriented music classification and recommends suitable music according to the recognized user's activity. For accurate music classification, a dynamic classification based on a modulation spectrum and a sequence classification based on a Mel-spectrogram are used in combination. In addition, simple accelerometer and gyroscope sensor data of the smartphone are applied to deep spiking neural networks to improve activity recognition performance. Finally, music recommendation is performed through a mapping table considering the relationship between the recognized activity and the indexed music file. The experimental results show that the proposed system is suitable for use in any practical mobile device with a music player.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.1
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• pp.233-241
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• 2013

One fundamental issue in ad hoc networks is the alternative node election problem, which reflects how well a sensor network is monitored or tracked by sensors. In this paper, we proposed EEAP(Energy-Efficient Alternative Paths). This is a method of selecting an alternative node for path routing management. When some node disconnection on the path routing, using pre-selected backup node provides immediately recover the path recovery. When selecting an alternative node of Step-Parents head node on the path management, the node's energy level and distance information are cared in context-awareness. This is not only increased the system's capacity cost effectively, but also reduce transmission power entire nodes consume energy. As a result, each node could efficiently management and improves the life time for mobile host and extends system coverage.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.2119-2124
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• 2008

An information-oriented basis in today's society has been changing fast, and the desire for connectivity has caused an exponential growth in wireless communication and sensor network. Sensor networks using RFID, in particular, have led this trend due to the increasing exchange of data in Ubiquitous such as the home RF, access control system, U-Healthcare, and Logistics information Systems. Also, the RFID when it applies a technique, is able to raise the stability of shipping as controling the mobile course and an entrance and exit of the crews an well as previously preventing an accident from shipping. In this paper, we designed and implemented personnel control system using UHF-RFID in vessels which shows through host PC reading and writing tag.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.397-399
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• 2005

무선 센서노드를 활용한 다양한 네트워크 설계 기술은 실생활의 각종 정보 수집에서부터 환경 모니터링까지 폭넓은 활용범위를 바탕으로 저전력 노드 설계 기술, 노드간 라우팅 프로토콜, 초소형 운영체제 및 미들웨어기술 등 관련 연구가 활발히 수행되고 있으며, 실내 센서네트워크에 분포된 노드의 절대위치를 측정하는 위치인식 시스템은 노드의 이동성, 다수성 그리고 환경의 제약성으로 인해 이를 보완할 시스템이 요구되고 있다. 이에 본 논문에서는 고정 센서노드의 배치밀도에 따라 위치정보를 선별적으로 처리하는 위치데이터 처리기와 다중 위치데이터의 발생을 원천적으로 차단하는 노드간 라우팅 기법을 통해, 센서노드의 이동성과 다중성을 효과적으로 보완하는 실내 이동객체 위치인식 시스템을 설계하고 서비스 구현을 위한 센서네트워크 플랫폼을 제안한다.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06a
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• pp.77-79
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• 2012

MSN 라우팅 프로토콜 설계에서 노드의 이동성 정도를 반영하는 것은 중요한 문제이며 다른 네트워크 인자의 특성들과 통합적으로 고려되어야 한다. 하지만, 기존 라우팅 기법들은 이동성의 고려가 미미하거나 다른 환경 인자들과 통합적인 고려가 되지 않았다. 본 논문에서는 모바일 센서 네트워크(MSN)에서 신뢰성 있고 에너지 효율적인 라우팅 기법을 제안한다. 먼저 동적인 네트워크 환경에서 이동성과 패킷발생율에 따른 에너지 소모 패턴 분석을 하였다. 분석된 결과를 바탕으로 제안 기법은 다양한 환경 인자에 따라 에이전트들이 싱크를 중심으로 자율적으로 구성하고 통신한다. 이러한 에이전트 기반의 라우팅 기법은 신뢰성 있고, 에너지 효율적인 통신을 가능하게 한다. 시뮬레이션 결과 제안 기법은 기존 기법에 비해 노드의 이동성의 변화가 심한 환경에서 에너지 효율적임을 보인다.

• The Korean Journal of Applied Statistics
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• v.19 no.3
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• pp.599-617
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• 2006

Recently many LBS(Location Based Service) systems are issued in mobile computing systems. Spatial-Temporal Moving Sequence Pattern Mining is a new mining method that mines user moving patterns from user moving path histories in a sensor network environment. The frequent pattern mining is related to the items which customers buy. But on the other hand, our mining method concerns users' moving sequence paths. In this paper, we consider the sequence of moving paths so we handle the repetition of moving paths. Also, we consider the duration that user spends on the location. We proposed new Apriori_msp based on the Apriori algorithm and evaluated its performance results.

• Journal of the Korea Convergence Society
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• v.6 no.4
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• pp.133-138
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• 2015

The basic idea of IoT(Internet of Things) is interconnection and cooperation with a variety of things in real life such as Radio-Frequency Identification(RFID) tags, sensors, mobile phone, etc, through internet. IoT technologies which applied to these fields consist of sensor network technology and middleware, application. Currently, IoT technology is applied to various fields such as health care, home care, automotive, transportation, construction, agriculture, environment, food, and etc, based on its technologies. This paper focuses on discussion of the game planning method in IoT environment. In order to achieve this purpose, first, introduce the IoT technologies. Second, propose a game design elements and considerations in IoT environments. It can help for game developers by using IoT technologies.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.10
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• pp.1128-1136
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• 2012

In this paper, the states and parameters in a dynamic system are estimated by applying an Unscented Kalman Filter (UKF). The UKF is widely used in various fields such as sensor fusion, trajectory estimation, and learning of Neural Network weights. These estimations are necessary and important in determining the stability of a mobile system, monitoring, and predictions. However, conventional approaches are difficult to estimate based on the experimental data, due to properties of non-linearity and measurement noises. Therefore, in this paper, UKF is applied in estimating the states and parameters needed. An experimental dynamic system has been set up for obtaining data and the experimental data is collected for parameter estimation. The measurement noises are primarily reduced by applying the Low Pass Filter (LPF). Given the simulation results, the estimated error rate is 39 percent more efficient than the results obtained using the Least Square Method (LSM). Secondly, the estimated parameters have an average convergence period of four seconds.

• The Journal of the Korea Contents Association
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• v.9 no.1
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• pp.115-122
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• 2009

In this paper, we proposed scheme that we use a difference of timestamp in time in Ubiquitous environments as we use the Diffie-Hellman method that OTP was applied to when it deliver a key between nodes, and can detect a malicious node at these papers. Existing methods attempted the malicious node detection in the ways that used correct synchronization or directed antenna in time. We propose an intermediate malicious node detection way at these papers without an directed antenna addition or the Trusted Third Party (TTP) as we apply the OTP which used timestamp to a Diffie-Hellman method, and we verify safety regarding this. A way to propose at these papers is easily the way how application is possible in Ubiquitous environment.

• Journal of the Korean Society of Systems Engineering
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• v.11 no.2
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• pp.41-49
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• 2015

Industrial safety is one of the crucial agenda for Government as well as Manufacturing Industry. To cope with the needs, a great deal of policies and technical implementation have been proposed and implemented. With a great increasing attention on the Industry 4.0 and Smart Factory, industrial safety has received as a crucial agenda by the manufacturing industry in particular. Up until now, almost all of them have been made from the environmental aspects, rather than operator or workers. In this paper, we present our research results how to increase the workers' safety via smart factory technology, such as IoT and CPS. Our approach has been to see the problem from SE perspectives, to draw the real issues from the various stakeholders, and define how to solve the problem based on the emerging technologies. The developed systems can give conceptual framework for the 'smart' industrial safety system by providing solution architecture for how to monitor the location of workers, and moving equipments, and generate solutions how to avoid safety problems between them if detected.