• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.19 no.7
• /
• pp.673-678
• /
• 2009

The efficiency of active sonar that is used underwater observation equipment is important for obtain the information of topography and trace for the objects. Sound wave transmitted from sonar are distorted by acoustic window which is to protect sonar. Making various sonar dome is impossible for experiment, because consumed unnecessary time and expense. So, the purpose of this study is to simulate and analyze the acoustic window propagated sound wave from sonar for designing model reduced insertion loss. Simulation is performed by transient analysis and fluid-structure interaction analysis. As a result, this study will give a opportunity for efficient design of sonar dome without high cost and time consumption.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2002.10a
• /
• pp.33-36
• /
• 2002

The purpose of this study is to develope a indicator for agricultural water use. Agricultural water is challenged by the increase of water use in the sectors of urbanization and industry and social pressure to use water in sustainable and environmentally sound way. The development of agricultural environment indicators is divided into 13 sectors, among which agricultural water use indicators include amount and intensity of agricultural water use, efficiency of agricultural water use, shortage or surplus of water use, water stress, etc.. Agricultural water use indicators provide basic data for sustainable and environmentally sound agricultural development, and also help policy decision makers to solve water shortage problems through water policy and water management measures by making the most of the total available water resources.

• Journal of Forest and Environmental Science
• /
• v.40 no.2
• /
• pp.141-150
• /
• 2024

This study aims to develop and commercialize a soundproof wall capable of planting at the urban ecological. The vegetative soundproof wall developed in the study showed highly superb structural test results for sound absorption coefficients and met the quality standards in the sound-absorbing performance test. Its structure is systemized to supply water to soils and plant roots inside the planting basis with rainwater running down the inclined planes near the planting basis in the front of the vegetation panel. It allows for sporadic water supply for about 30 days of drought. The test results show that the plants continued favorable growth and development in leaves, stems, and roots, making the vegetative soundproof plate a product capable of reacting to climate environment changes.

• Journal of the Korean Wood Science and Technology
• /
• v.42 no.6
• /
• pp.714-722
• /
• 2014

In the previous study, a variety of wood-based panels was thermally decomposed to manufacture carbonized boards that had been proved to be high abilities of insect and fungi repellence, corrosion and fire resistant, electronic shielding, and formaldehyde adsorption as well as sound absorption performance. Based on the previous study, carbonized medium density fiberboard (c-MDF) was chosen to improve sound absorption performance by holing and sanding process. Three different types of holes (cross shape, square shape, and line) with three different sanding thickness (1, 2, and 3 mm) were applied on c-MDF and then determined sound absorption coefficient (SAC). The control c-MDF without holes had 14% of SAC, however, those c-MDFs with holes had 16.01% (square shape), 15.68% (cross shape), and 14.25% (line) of SAC. Therefore, making holes on the c-MDF did not significantly affect on the SAC. As the degree of sanding increased, the SAC of c-MDF increased approximately 65% on sanding treated c-MDFs (21.5, 21.83, and 19.37%, respectively) compared to the control c-MDF (13%). Based on these results, composite sound absorbing panel was developed with c-MDF and MDF (11 mm). The noise reduction coefficient of composite sound absorbing panel was 0.45 which was high enough to certify as sound absorbing material.

• Journal of Broadcast Engineering
• /
• v.9 no.4 s.25
• /
• pp.424-433
• /
• 2004

Jing(gong) is one of the most well known Korean traditional Samulnori instruments to the general public. Samulnori is consisted of four instruments, them being : the jingo the janggu (hour-glass drum). the kkwaenggwari, and the buk(drum). Of the four instruments, the jing with its deep, and yet soft and beautiful long lingering sound embraces the sounds of the other three. The jing is a brassware instrument, a compound of $70{\%}\;copper\;and\;22{\%}\;tin.$\;A high quality brassware is used when the jing is made. The jing is shaped with a 39-40cm circular plate and a rim that gives 7.0-7.5cm of depth to the instrument. Even with its most simple structure, when the circular plate is hit during performance, the rim which supports the circular plate gives resonance to the sound making low-frequency sounds. Therefore the range of the representative frequency of the full rim jing is between $118.4{\~}366.0[Hz],$\;the lingering sound lasts for more than 20 seconds afterwards. When the jing with half of its rim cut off is hit the basic frequency is $139.9{\~}387.5[Hz].$\;And the sound lasted for ten more seconds. The jing of its rimless frequencies are distributed between $990.5{\~}1,372[Hz].$\;And the lingering sound lasts for 5seconds afterwards. Therefore, different thickness and depth of the rim may give new resonance frequencies and alter the longing time of the sound. This thesis paper will try to reveal the relationship between the thickness or depth of the rim (which holds the bending circular plate) and the frequency or the lasting time of the sound.

• Archives of design research
• /
• v.19 no.5 s.67
• /
• pp.95-104
• /
• 2006

The advertisement is an informative product in which a company or an organization has made a substantial capital investment in order to achieve their goals based on their carefully thought-out plans. David Ogilvy maintaned that making a headline of an advertisement is worth 80 percent completion of the advertisement. As he insisted, a headline is also the most important element in the printing advertisement. Therefore, the importance of selecting headline's font style is increased because, while creating a headline, it is necessary to consider the emotional aspects of the advertising object that attract the attention of people. Many researchers call 'typography' as 'frozen sound' or 'written sound' because typography not only works as a letter but also provide people with an emotional pleasure. An appropriate selection of headline's font style in the advertisement production makes both the client and the audience for the advertisement satisfied because it reduces the communication risk and makes design results more reasonable. It is difficult to find many decision-making methods for selecting headline's font style. Therefore, the author of this paper investigated the trend of the use of headline's font style in order to help the designer understand headline's font style as one of design factors. As a result of the research, it is possible to conclude that, while selecting the headline's font style, the attributes of a font consist of limited style, and more objective and systematic font selection methods are necessary.

• Journal of Korea Game Society
• /
• v.2 no.1
• /
• pp.84-91
• /
• 2002

The big difference of game scenario writers from ordinary scenario writers is the creativity of interactive game element. Game scenario writers should complete scenario form before making conti of game production, develop new item that is the essence of game and be able to write mulit-scenario for diverse story developments. Also, he should have the ability to advise on effective arrangement for sound effect to game designer.

• The Journal of the Acoustical Society of Korea
• /
• v.1 no.1
• /
• pp.76-81
• /
• 1982

To get minimum noise level by making full use of the constrained geometric space and being compatible with the minimum pressure-drop condition, 3-pipe through-flow system is designed by inserting a new pipe which is shaped a resonator in the cavity of 2-pipe system. As a result of the 1/3-octave-band frequency analysis for the noise reduction characteristics, this system is proved to have good sound attenuation effect in the high frequency region, so that it is found to be a useful component of a muffler.

• Proceedings of the Safety Management and Science Conference
• /
• 2003.05a
• /
• pp.143-147
• /
• 2003

This study is to develop a device of bath-seat with massage which is attached to bath-seat and is able to sustain massage on perineal region and anus effectively. And also develop new programmed driving-seat that is able to protect drowsiness. This seat is operated easily by user controlling time period (eg. 30 minutes or 60 minutes) of vibration. During the vibration, user can make a choice of making n sound which is proved as a better effects for concentration and comfort.

• Korean System Dynamics Review
• /
• v.10 no.1
• /
• pp.33-60
• /
• 2009

This study explores the limitation in making a causal model through an existing case and proposes an alternative plan to improve a theoretical system of causation modeling. To make a dynamic and actual model, several principles are needed such as reality based analysis of system structures and dynamics, consistent expression of causations, conversion of numerical formulas to causal relations, classification and arrangement of variables by size of concept, etc. However, it is hard to find cases to apply these considerations from existing models in System Dynamics. Therefore, this study verifies errors of derived models from literatures and proposes principles and guides that should be considered to make a sound dynamic model on a causal map. It contributes to making an opportunity for exciting public opinion to improve theory about causal maps, yet it has limitation that the study does not advance forward to the experimental step. For future study, it plans to make up by classifying and leveling causal variables, developing a dynamic BSC model.