• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.699-703
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• 1993

When the error path can be modeled as a pure delay, an adaptive algorithm for slowly time varying system is proposed to minimize the sound pressure level. This algorithm makes it possible to use the fittered-x LMS algorithm with on-line delay modeling of the error path. Another simple adaptive algorithm for pure tone noise is proposed which eliminates the cross term in the multiple error filtered-x LMS algorithm.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.791-796
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• 2003

Some basic guidelines for changing non-uniform boundary condition in an acoustically small cavity are presented. In this paper, modal summation technique is used to represent inside sound field. From this formulation, corner effect is defined and proposed. The corner in a cavity is good position for changing boundary condition effectively. Impedance circle with same absorption coefficient is defined to find appropriate impedance of absorptive material for better noise control performance.

• Proceedings of the Korea Database Society Conference
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• 1995.12a
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• pp.3-19
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• 1995

시스템 Technology ★ Server Technology - 운영환경구축 ★ Network 구성설계 - ATM, FDDI, NMS ★ Client/Server시스템 구성별 Bench Marking ★ Windows 메뉴 및 GUI 설계 ★다기능 PC 운영환경 설정 시스템 Technology ★ Data Base Technology - DB Administration - BB Performance Tuning ★ System Integration Technology - Application Integration - System Flow Control - Task Control - Applicational Interface - S/W Down Load 시스템 Technology ★ Memory Optimization ★ IBM/Facom Host API ★ 영상전화 Customizing - Intel Proshare ★ Auto Dialing - CTI Link ★ IC-Card Interface 시스템 Technology ★ Sound 처리 - Voice Mail - 음절 처리 ★ Image 처리 ★도움말 처리 - Hyper Text 시스템 Technology ★ Socket Programming - 긴급메일 - Peer to peer message switching ★ Set Up Programming -Install Shield ★ DB Access Programming - DB-Library ★ TCP/IP Programming(중략)

• Proceedings of the Korea Information Processing Society Conference
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• 2008.05a
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• pp.508-511
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• 2008

In this paper, we propose software architecture for conveying contents-based OpenSound Control (OSC) packet from manipulation user interface to cooperative remote multi-robots. The Flash application is used as a controlling user interface and the physical prototyping of multi-robots were developed using physical prototyping toolkit.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.241-242
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• 2023

This paper discusses an innovative acoustic membrane developed by doAZ Co., Ltd., offering enhanced noise barrier and dust control for urban construction and demolition, surpassing the performance of traditional non-woven fabrics. The membrane is made from recyclable bubble sheets and designed to be seamlessly integrated into single and double-row scaffolding systems, ensuring broader applicability and sustainability.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.403-408
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• 2000

An acoustic field in a 3 dimensional enclosure is caused from interference between sound sources and the complex reflections from wall. Therefore, changing an acoustic property of wall such as admittance means generating another acoustic field. The purpose of this paper is utilizing the characteristic to make a quiet zone. First, this paper shows that the control material is essentially on the same road as active noise control(ANC). That is, we can consider the control material as the control source of ANC. However we cannot control the reflection strength of it. Second, through a numerical simulation, this paper shows that the position of the control material is an important variable of the control.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.261-265
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• 2013

The purpose of this study was to evaluate noise level exposures at different locations such as the left and right ears of the shooter, control room, waiting soldier location and drill ground. For this study, we visited two military rifle ranges and took measurements with a sound level meter (3M Quest SoundPro TM) at five different locations with values of Peak (dB(A)) and Max (dB(A)). The highest peak value of impulse noise level averaged 150.4 dB(A), ranging from 149.6 to 150.5 dB(A) at both the left and right ear sides. This result was significantly different between both left and right ear side locations and at other locations such as the control room, waiting soldier location, and drill ground (P < 0.001). Frequency of impulse noise exposure level showed that the left ear of shooter had the highest frequency (20 times) at over 150 dB(A). This study confirmed that there is a need for proper controls to reduce the amount of impulse noise exposure at military rifle ranges.

• Journal of Environmental Health Sciences
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• v.39 no.4
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• pp.354-359
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• 2013

Objectives: The purpose of this study was to investigate exposure levels to K2 rifle noise at a military rifle range among soldiers in training, the left and right ears of shooters, and control managers in the day and night times. Methods: For this study, we visited military rifle ranges and measured the noise of a K2 rifle with a sound level meter (3M Quest SoundPro$^{TM}$) at four different locations with values of Peak (dB(A)) and Max (dB(A)). Results: The highest peak value of impulse noise level averaged 150.4 dB(A), ranging from 149.7 to 150.5 dB(A) at the left-ear side. Impulse noise levels in the daytime were also recorded as higher than during the night. This result was significantly different between daytime and nighttime locations, such as soldier training, right ear of shooter, and control manager (P < 0.001). Conclusion: This study confirmed that there is a need for proper management of impulse noise at military rifle ranges.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.7
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• pp.562-569
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• 2016

This paper proposes a navigation system with a robust localization method for an underwater unmanned vehicle. For robust localization with IMU (Inertial Measurement Unit), a DVL (Doppler Velocity Log), and depth sensors, the EKF (Extended Kalman Filter) has been utilized to fuse multiple nonlinear data. Note that the GPS (Global Positioning System), which can obtain the absolute coordinates of the vehicle, cannot be used in the water. Additionally, the DVL has been used for measuring the relative velocity of the underwater vehicle. The DVL sensor measures the velocity of an object by using Doppler effects, which cause sound frequency changes from the relative velocity between a sound source and an observer. When the vehicle is moving, the motion trajectory to a target position can be recorded by the sensors attached to the vehicle. The performance of the proposed navigation system has been verified through real experiments in which an underwater unmanned vehicle reached a target position by using an IMU as a primary sensor and a DVL as the secondary sensor.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.4
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• pp.427-435
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• 2011

This paper deals with the measurement and analysis of the squeal noise according to the curvature of rail. The squeal noise is generated by the friction between the railway with curve and the wheel. The squeal noise is a big problem in Busan Metro Line 3. If the developing panel type ANC(Active Noise Control) system which is attached to the floor can reduce 5 dB in below 500 Hz, the sound pressure level of the whole band pass can be reduced about 4-4.8 dB in squeal noise above the curvature of R400. Curve squeal noise is the intense high frequency tonal that can occur when a railway vehicle transverses a curve. The frequency range is from around 500 to almost 20,000 Hz, with noise levels up to about 15 dB in curve.