• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.1
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• pp.18-25
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• 2018

In this paper, we present a low-power implementation of the multi-channel hearing aid system using a general-purpose DSP chip. The system includes an acoustic amplification algorithm based on Wide Dynamic Range Compression (WDRC), an adaptive howling canceller, and a single-channel noise reduction algorithm. To achieve a low-power implementation, each algorithm is re-constructed in forms of integer program, and the integer program is converted to the assembly program using BelaSigna(R) 250 instructions. Through experiments using the implementation system, the performance of each processing algorithm was confirmed in real-time. Also, the clock of the implementation system was measured, and it was confirmed that the entire signal processing blocks can be performed in real time at about 7.02MHz system clock.

• Journal of the Institute of Convergence Signal Processing
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• v.7 no.3
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• pp.116-121
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• 2006

In this paper, we propose the dimension reduction method of multi-dimension speech feature vector for real-time adaptation procedure in various noisy environments. This method which reduces dimensions non-linearly to map the likelihood of speech feature vector and noise feature vector. The LRT(Likelihood Ratio Test) is used for classifying speech and non-speech. The results of implementation are similar to multi-dimensional speech feature vector. The results of speech recognition implementation of detected speech data are also similar to multi-dimensional(10-order dimensional MFCC(Mel-Frequency Cepstral Coefficient)) speech feature vector.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1320-1326
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• 2011

The maximum speed of high-speed rail is restricted to various factors such as track condition including slope and radius, tunnel and dynamic stability of vehicle. Among the various factors, traction effort and resistance to motion is principal and basic factor. In addition, at high speed over 300km/h, aerodynamic drag amounts up to 80% of resistance to motion, that it can be said that aerodynamic drag is the most important factor to decide the maximum speed of high-speed rail system. This paper deals with a measure to increase the maximum speed of high-speed train by reducing aerodynamic drag. The traction effort curve and resistance to motion curve of existing high-speed train under development has been employed to set up the target of aerodynamic drag reduction to reach up to 500km/h without modification traction system. In addition, the contribution of various sources of aerodynamic drag to total value has been analyzed and the strategy for implementation of aerodynamic drag reduction has been discussed based on the aerodynamic simulation results around the train using computational fluid dynamics.

• Structural Engineering and Mechanics
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• v.38 no.2
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• pp.141-156
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• 2011

A cable stayed bridge under construction has low structural damping and is not as stable as the completed bridge. Control countermeasures, such as the installation of energy dissipating devices, are thus required. In this study, the general procedure and key issues on adopting an active control device, the active mass damper (AMD), for vibration control of cable stayed bridges under construction were studied. Taking a typical cable stayed bridge as the prototype structure; a lab-scale test structure was designed and fabricated firstly. A baseline FEM model was then setup and updated according to the modal parameters measured from vibration test on the structure. A numerical study to simulate the bridge-AMD control system was conducted and an efficient LQG-based controller was designed. Based on that, an experimental implementation of AMD control of the transverse vibration of the bridge model was performed. The results from numerical simulation and experimental study verified that the AMD-based active control was feasible and efficient for reducing dynamic responses of a complex structural system. Moreover, the discussion made in this study clarified some critical problems which should be addressed for the practical implementation of AMD control on real cable-stayed bridges.

• Information Systems Review
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• v.11 no.2
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• pp.169-182
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• 2009

Due to natural oligopolistic industry characteristics and huge influences on national and home economy, Telco Industry is regarded as a regulated industry. Thus, telco companies, including CATV, prepare not only management accounting reports for internal use but also regulatory accounting reports to be submitted to the regulatory agency. For telco companies, smooth integration of these financial, managerial and regulatory reporting requirements with legacies such as billing system, network operating systems is important to achieve operational efficiency and overall competency. This research studies telco ERP cost module implementation in order to provide theoretical and practical guidance for integrated information system. Especially, case analysis focuses on cost reduction and network costing implementation that involves Building Block Costing methodologies.

• Environmental and Resource Economics Review
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• v.15 no.1
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• pp.95-133
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• 2006

This research first reviewed and analysed the current domestic situation of the voluntary agreement implementation and then it developed the policy implementation scenarios which will be applied to the model, KORTEM_ V.2. The model, consisted with 83 industries and commodities, examined the economic and environmental impacts of this policy instrument. Depending on the efforts of participating sectors and agents for fuel substitution and energy efficiency improvement, it has been evaluated that the voluntary agreement could be the "no-regret" policy. In other words, if the participating sectors and agents can achieve the voluntary energy conservation and emission reduction target without the negative impact on output level, the reduction of national emission will be achieved by creating the economic benefit, simultaneously. Therefore, for the successful implementation of voluntary agreement, this study emphasized the importance of expansion and strengthening of the current financial and institutional support for participating sectors and agents.

• Proceedings of the KIPE Conference
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• 1996.06a
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• pp.93-98
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• 1996

This paper presents active silencer by hysteresis control method using DSP-scheme and shows it audible noise reduction effect. Pentium processor and sound blaster 16 are used for its implementation. The sound blaster 16 executes A/D, D/A conversion and is used operating source of loudspeaker for cancelling.

• Journal of Industrial Technology
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• v.29 no.B
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• pp.151-155
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• 2009

In this paper, we implement a spatial data management system which is based on GIS technology. GIS technology is tightly related with spatial information and will be important method for future information-oriented society. The implemented system collects and manages spatial data. In the implementation, we use PostgreSQL DBMS. We also implement magnification, reduction, movement and search functions in the system.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.157-162
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• 2005

This paper describes the system implementation of TMS(Train Management System) to be applied to a TTX(Korea Tilting eXpress). For better safety and reliability of vehicle, increased quantity and fast transmission of data between TC(Train Computer) and CC(Car Computer) and control equipment of train is required. To satisfy these requirements, this system uses RTOS(Real Time OS) so that do realtime data management, And it is implemented to minimize the noise inflow and a signal level reduction of the communication line. Also it is designed to suitable interface of a TTX vehicle and is verified by laboratory test.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.188-194
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• 2000

This study is about fault detection and fault area detection of LV circuit in Cab Cubicle system which have control of train to keep safety in High Speed Train. LV circuit is operated with diagnosis system like safety system. In this paper, we suggest a design and an implementation method to detect fault or to detect fault area automatically about LV circuit. The implemented system is tested successfully after implementation of some function. We expect reduction to diagnosis area or repair time by fault area module