• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.752-760
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• 1993

We research ed on the noise control of a head feeding type combine harvester. It is a kind of combine harvester developed in Japan. And at present, it is used by most Japanese farmer. For a head-feeding type combine harvester it is very difficult to determine the sources of noise because it is a combination of reapers and automatic , threshers and several running parts. However we succeeded in finding out the sound sources of combine harvesters and analyzing their sound by the using sound intensity method. The sound intensity Method is a very up-to-date method to measure and analyze Sound Intensity Levels and sound directions at several measuring point sin a specified area. In this research, first a conventional sound level measurement method is used and secondly the sound intensity method. The first method shows a rather great limitation in allowed exposure duration. The second method shows pin-points the engine itself as being the main source of noise, causing sound flows a ross the operator's seat.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1437-1442
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• 2006

The international competition in car markets has continuously required the research about the sound quality of a car. The domestic carmakers have also invested a lot of money for the research and development of interior sound quality of passenger cars. Therefore, the aim of this research is to predict the customer's evaluation of a new vehicle. There are two major research works to achieve this goal in this research. The first one is to search questionnaires about the sound quality, which customers prefer, to identify the relationship between these questionnaires and sound metrics that is a psychoacoustics parameters, and to development sound indexes for the questionnaires. All tests for this work is proceed on the road test during acceleration. The second one is to balance the sound component (engine noise, booming noise, road noise and wind noise) of a passenger. This wok will be tested on the constant speed. All of research results will be contributed to the development of brand sound quality of a new passenger car.

• Cartoon and Animation Studies
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• s.15
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• pp.221-235
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• 2009

Most of the sounds used in animated films are artificially made. A large number of the sounds used are either actual sound recordings or diversely processed artificial sounds made with professional sound equipments such as synthesizers. One animation episode contains numerous amounts of sounds, resulting in significant sound production costs. These sounds have full potential to be reused in different films or animations, but in reality we fail to do so. This thesis discusses ways these sound sources can be acknowledged as added new values to the present market situation as a usable 'digital content'. The iTunes Music Store is an American Apple company product that is acknowledged as the most successful digital content distribution model at the time being. Its system's sound library has potential for application in the Korean sound industry. In result, this system allows the sound creator to connect directly to the online store and become the initiative content supplier. At the same time, the user can receive a needed content easily at a low price. The most important part in the construction of this system is the search engine, which allows users to search for data in short periods of time. The search engine will have to be made in a new manner that takes into consideration the characteristics of the Korean language. This thesis presents a device incorporating the Wiki System to allow users to search and build their own data bases to share with other users. Using this system as a base, the Korean animation sound library will provide development and growth in the sound source industry as a new digital sound content.

• Journal of Digital Contents Society
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• v.8 no.4
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• pp.579-586
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• 2007

The process of developing a online 3D game engine involves designing details of the engine, alpha test, adjustment, supplementation, beta test and introduction, and an online 3D game engine is made of a server engine and client engine. The server engine, which is made of server construction part, distribution center and DB construction part for building asymmetric multiple servers, is developed by Linux, and the client engine, which is made of a graphic part, sound part, AI part and object management part, is developed by using DirectX in Windows, and it proposes an engine configuration and method based on 3D engine technology by analyzing the network technology, which is a common engine technology.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.399-404
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• 2002

Analyzing acoustic-structural systems such as automobiles and aircraft the FRF-based substructuring method is one of the most powerful tools. In this paper, an optimization procedure far the engine mount system of passenger car has been presented using the design sensitivity analysis based on the multi-domain FRF-based substructuring formulation. The proposed method is applied to an optimization problem of the engine mount system, of which objective is to minimize the interior sound over the concerned rpm range. The design variables selected are the stiffnesses of the engine mounts and bushes. Plugging the gradient information calculated by the proposed method into nonlinear optimization software, we can obtain the optimal stiffnesses of the engine mounts and bushings through design iterations. The optimized interior noise in the passenger car shows that the proposed method is very useful in the realistic situation.

• Journal of Biosystems Engineering
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• v.20 no.2
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• pp.117-126
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• 1995

High level of tractor noise may reduce operator's work performance and cause a hearing problem. This study was carried out to investigate the cab noise of a selected agricultural tractor. The noise was measured and analyzed in terms of sound and sound intensity levels. Form the results it was known that a structure-born noise was induced from the feet-rest and rear floor panel of the cab. The air-borne noise caused mainly by the engine was transmitted into the operator's position through the small openings of cab structures in the operator's lower front area.

• Journal of Biosystems Engineering
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• v.14 no.4
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• pp.251-261
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• 1989

The amount of grain loss incurred during harvesting operation through the chaff-outlet of combine may not be negligible. To minimize this grain loss and optimize condition of combining, it may be necessary that the amount of chaff-outlet loss dependent on varying crop condition is to be estimated as exactly as possible. This study was thus intended to develop the monitor that could indicate the amount of grain loss occurred through the chaff-outlet of combine during harvesting operation. The function of this monitor is to measure at the sounding board the impact sound of paddy kernels which could be distinguished from those of other threshing products through chaff-outlet, and from vibration or noise created by the combine engine and other moving parts. To develop such monitor, the frequency distributions of each sound generated by the impact of grain and chaff, the sound generated by the impact of the mixture of grain and chaff, and vibration or noise created by the combine engine and other moving parts were investigated experimentally. From the results of frequency analyses, the trainsducer adequate for the monitering system was selected and sounding board was constructed. The grain loss monitor thus obtained was tested by attaching the sounding board to the chaff-outlet of combine.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.274-279
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• 2000

Driving of the engine makes unbalance forces which induces vibration to the engine mount system. Active vibration control must be performed to reduce the vibration and the propagation of structure-born sound. In this study, the engine system is modeled as 3-dim. vibration system including flexible structures and an effective active noise control method is proposed. Also, appropriate actuator and sensor locations and types are selected. The miniature of the engine vibration system with multi-input multi-output is built and an active vibration control with multiple filtered-X LMS algorithm is applied to it. The applied control method was effective to reduce the transmitted vibration power through the rubber mount It showed the feasibility of the control of the engine vibration systems with flexible structures.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.3
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• pp.202-208
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• 1997

The knocking is one of major parameters to improve engine performance in a spark ignition engine. Many researches have been carried out to identify them using cylinder pressure, vibration signal and so on. In the present study, measurement and analysis was conducted to set up the criteria of knock occurrence by using microphone signal. Cylinder pressure was measured for the reference signal of knocking. It has been observed that resonance frequencies of pressure wave are nearly independent of engine operating conditions such as engine speed, air fuel ratio, load and octane number of fuel within to limited experimental conditions. SDBP(sum of different band-pass data) method using resonance frequency of knock was proposed for estimating knock intensity. SDBP method is superior to identify knock occurrence and its intensity in case of sound pressure measurement.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.37-45
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• 2003

The diesel engines was invented a little more than one hundred years ago and has ever since been developed for better fuel economy, increased power and smaller size. Thanks to its fuel economy, the diesel engine is today the dominating prime mover in many applications, such as smaller power plants, commercial ships, trains, trucks, buses and all kinds of mobile construction machinery. As engine for passenger cars, the diesel engine is steadily increasing its share of the market. However, its versatility and, consequently, large prevalence have led to environmental demands to its exhaust emissions, noise and vibration. This paper deals with the noise aspects of diesel engine designs of the so-called low speed two-stroke type installed in most large ships.