• International Journal of Advanced Culture Technology
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• v.9 no.2
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• pp.123-129
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• 2021

When shaving, it is easy to suffer shaving burns, that is, facial burn irritation during shaving. The reason is that the razor blade irritates the skin. The current solution is to make the razor sharper and use a razor with a blade heating function. Although these ways can increase the comfort of shaving, they will also greatly increase shaving costs. This paper proposes using a hairdryer to massage the skin before shaving to reduce skin irritation during shaving. This is a simple, practical and low-cost method. The hair dryer's heat, sound, and wind energy have a massage effect, and they can make shaving easier and more comfortable. For analyzing shaving effect, two evaluation methods are used, which are sound spectrum analysis and mos. The sound spectrum analysis is used to analyze the working status of the razor objectively. The MOS test can reflect the subjective feelings of the subject on the shaving's comfort. The results show that the hairdryer thermal vibration massage can make the beard easier to cut, thereby reducing the irritation of the razor to the skin and improving shaving comfort.

• Journal of the Korean Wood Science and Technology
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• v.49 no.1
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• pp.82-92
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• 2021

Nakdong technique is an unfamiliar scorching treatment using an iron heated in a kiln over 1000℃. It is a typical convention in Asian countries to treat Nakdong on the surface of paulownia species. The scorching treatment changes the surface characteristics as well as the color of the wood. This study focused on the effects of functional features such as water resistance, anti-mold, anti-termite, and sound improvement because this treatment is usually used on paulownia wood-bodied musical instruments surface. It took 28'57" for Nakdong-iron treated surface to absorb a droplet of water. The absorbance time of iron treated surface was longer than that of torch treated one. There was no noticeable effect on the anti-mold test. On the anti-termite test, there was nearly 3% more mean mass loss on the torch samples than controlled and iron treated ones. In examining the sound radiation coefficient before and after Nakdong treatment, the Nakdong-iron treated surface showed an increase in the average value of 1.2 m4/kg s, which means that it has sound quality improvement. Through this research, the Nakdong technique results are expected to be used as basic-data for further research and give a practical idea for using the traditional treatment method on the wood surface.

• Journal of the Korean Wood Science and Technology
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• v.31 no.4
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• pp.1-7
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• 2003

Anatomical and physical characteristics of damaged wood by forest fire and sound wood of Pinus densiflora were examined. Granular substances were found in resin canals, epithelial cells and ray parenchyma cells of damaged wood, but the other distinctive marks of wood structure in damaged wood were not observed. Damaged wood showed slightly higher relative crystallinity in outermost growth ring than sound wood. Green moisture content and water absorptions both in tangential and radial sections of damaged wood were lower than those of sound wood. There were no significant differences in shrinkage, swelling and basic density between damaged and sound woods.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.8
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• pp.592-597
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• 2013

It is widely known that the sound insulation of soundproof panel is highly correlated to two factors, surface density of material and the frequency of noise. Accordingly, the character of traffic noise released in actual situation is important requisite for determining thickness to determine surface density and material of soundproof panel. This present study selected polymer panel with advantage of light weight and workability and evaluates according to frequency of traffic noise. Polypropylene (PP) and high-density polyethylene (HDPE) were selected as subjects based on economic valuation and efficiency. The sound transmission loss of selected polymer panels were compared with the currently used panels such as polycarbonate (PC) and polymethyl methacrylate (PMMA) depending on thickness and materials. As a result, PC showed the highest sound transmission loss followed by PMMA, HDPE, and PP in range of mass law. In terms of acoustic performance on thickness, the transmission loss increased with thickness of soundproof panel meanwhile coincidence dip was observed in lower frequency where had reduced transmission loss. Therefore, it is suggested that after determining target frequency, the kind of materials and thickness of soundproof panel need to be designed so that traffic noise can be more efficiently reduced.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.21 no.1
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• pp.12-18
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• 1985

In general the impulse sound sources of underwater generated by electric arc discharge had used static energy of the charged capacitors. The author proposed an underwater arc discharge sound source using secondary voltage of high voltage transformer without capacitors. The arc discharge device was composed of a high voltage transformer and a switching system. The impulse current in the primary turn of the high voltage transformer is controlled by the switching system and inductive current of the secondary turn in the high voltage transformer is used in making impulsive arc discharge. A series of experiment have been carried out to observe the acoustic characteristics of the impulse sound source generated by the arc discharge. The results obtained were as follows: 1. Secondary current at the time of arc discharge keeps after ohm's law in the beginning and the maximum current flows out as soon as arc discharge breaks out. 2. A time difference between a start of applied current and a generation of arc discharge sound is the 3msec and it is generated arc sound when breaking down electric insulation at maximum voltage. 3. The sharper the end of electrodes and the higher the secondary voltage, the higher the sound pressure level. 4. Arc discharge sound was generated even at the distance of 100cm between electrodes and was stably reproductive at the gap of 1cm to 100cm. 5. Electric arc discharge sound wave is a shock wave of pulse-width of 0.15msec and spectral distribution of it is plenty of low frequency components less than 10 KHz.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.7
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• pp.1030-1037
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• 2013

Early detection of anomalies is an important issue in the management of group-housed livestock. In particular, failure to detect oestrus in a timely and accurate way can become a limiting factor in achieving efficient reproductive performance. Although a rich variety of methods has been introduced for the detection of oestrus, a more accurate and practical method is still required. In this paper, we propose an efficient data mining solution for the detection of oestrus, using the sound data of Korean native cows (Bos taurus coreanea). In this method, we extracted the mel frequency cepstrum coefficients from sound data with a feature dimension reduction, and use the support vector data description as an early anomaly detector. Our experimental results show that this method can be used to detect oestrus both economically (even a cheap microphone) and accurately (over 94% accuracy), either as a standalone solution or to complement known methods.

• Food Science and Biotechnology
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• v.14 no.6
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• pp.738-742
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• 2005

We developed a musical composition and performing method for the dynamic expression of food taste, to replace the static expression obtained from a numerical sensory score and linguistic method. The musical score was composed using cognitive food sensory data gathered while eating potato chips via a computer equipped with a sound card and a master keyboard, as well as Cakewalk 9.0, Goldwave 5.0, and Windows Media Player. The music score included four lines, one representing sensory data and three reflecting three layers of human consciousness. Different time units were applied by incorporating different repetition cycles for the relevant consciousness layers. The musical scores of individual subjects differed in terms of the score pattern and its sound. The music representing food taste was played by four instruments and showed different sound and acoustic frequency patterns for each individual subject during the consumption of potato chips. The musical expression method was applied to analyze the individual taste characteristics in the cognition of food.

• International journal of advanced smart convergence
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• v.9 no.4
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• pp.132-138
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• 2020

Worldwide, the number of corona virus disease 2019 (COVID-19) confirmed cases is rapidly increasing. Although vaccines and treatments for COVID-19 are being developed, the disease is unlikely to disappear completely. By attaching a smart sensor to the respirator worn by medical staff, Internet of Things (IoT) technology and artificial intelligence (AI) technology can be used to automatically detect the medical staff's infection symptoms. In the case of medical staff showing symptoms of the disease, appropriate medical treatment can be provided to protect the staff from the greater risk. In this study, we design and develop a system that detects cough, a typical symptom of respiratory infectious diseases, by applying IoT technology and artificial technology to respiratory protection. Because the cough sound is distorted within the respirator, it is difficult to guarantee accuracy in the AI model learned from the general cough sound. Therefore, coughing and non-coughing sounds were recorded using a sensor attached to a respirator, and AI models were trained and performance evaluated with this data. Mel-spectrogram conversion method was used to efficiently classify sound data, and the developed cough recognition system had a sensitivity of 95.12% and a specificity of 100%, and an overall accuracy of 97.94%.

• Structural Engineering and Mechanics
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• v.89 no.3
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• pp.265-281
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• 2024

The sound radiation responses of multi-layer composite plates subjected to harmonic mechanical excitation in hygrothermal environment is numerically investigated. A homogenized micromechanical finite element (FE) based on the higher-order mid-plane kinematics replicating quadratic function as well as the through the thickness stretching effect together with the indirect boundary element (IBE) scheme has been first time employed. The isoparametric Lagrangian element (ten degrees of freedom per node) is used for discretization to attain the hygro-thermo-elastic natural frequencies and the modes of the plate via Hamilton's principle. The effective material properties under combined hygrothermal loading are considered via a micromechanical model. An IBE method is then implemented to attain structure-surrounding coupling and the Helmholtz wave equation is solved to compute the sound radiation responses. The effectiveness of the model is tested by converging it with the similar analytical/numerical results as well as the experimentally acquired data. The present scheme is further hold out for solving diverse numerical illustrations. The results revealed the relevance of the current higher-order FE-IBE micromechanical model in realistic estimation of hygro-thermo-acoustic responses. The geometrical parameters, volume fraction of fiber, layup, and support conditions alongside the hygrothermal load is found to have significant influence on the vibroacoustic characteristics.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.6
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• pp.847-854
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• 2013

This paper implements a smartphone application for sound recording and player of mobile learning. Due to its ubiquitous nature, smartphones could be used anytime anywhere, and because they combine an audio and a microphone, the application for sound recording and player that this paper suggests can be easily and cost effectively developed without additional infrastructure. This paper also explains a technique which processes data of music lyrics. The technique is built on a database technology by using SQLite, a DBMS combined in a platform of android. Thus, as long as the smartphone application for sound recording and player is developed and the mobile phone has sound source files, learners could record their own voices to the sound. Therefore, we expect the learners without additional infrastructure to enable mobile learning.