• The Journal of the Acoustical Society of Korea
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• v.28 no.8
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• pp.781-789
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• 2009

The absorption coefficients of the materials used in a 1:50 scale model multipurpose hall were measured based on ISO 354 and related laws. The shape and materials for the scale model were evaluated based on reflective surfaces, variable acoustic elements and sound-absorbing quality (125Hz-1kHz average) of seats. The measured average absorption coefficients of audience seats, audience and orchestra were 0.64, 0.74 and 0,45, respectively, which were simulated with the combination of wood, absorption materials and foam board. Various mounting methods for absorption curtain and banner were considered according to the installation methods. The average absorption coefficient was measured as 0.42, 0.47 and 0.45 in the conditions of Type A mounting, E mounting with 0.9 m backing air cavity, and Type G mounting which is suspended at the ceiling, respectively. It was confirmed that the absorption coefficient was increased at low frequency by backing air gap. The finishing material of stage house was an absorption material covered with thin fabric, which aimed average absorption coefficient of 0.68 by using fiber glass board. Each part of the real materials was compared with those of 1:50 scale model and it was found that the absorption characteristics of both cases were similar.

• Korean Journal of Food Science and Technology
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• v.15 no.2
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• pp.141-149
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• 1983

The purpose of the present work is to find out the optimal conditions for the production of filefish protein preparations and to define the functional properties of the protein products. Fish protein concentrate (FPC) and fish protein isolate (FPI) were prepared by extraction of whole or headed and gutted filefish with various organic solvents. The results of the present study are as follows; 1. Among the solvents tested iso-propyl alcohol appeared to be the most effective for the extraction of lipid and also for that trimethylamine from the fish muscle. 2. The optimal extraction time showed to be 20 minutes with ethyl iso-propyl alcohol at $65-70^{\circ}C$under adequate mixing. 3. The most effective solvent ratio to the weight of fish material was proved to be 5:1 at the first extraction and to be 2:1 at the second stage. 4. The lipid content of the protein preparations reduced to below 0.5% by the third stage of extraction of headed or gutted filefish. The protein concentrate from whole fish, however, showed the lipid content of 0.27-0.31% only after the fifth stage of extration. 5. The protein contents of the protein concentrate and the protein isolate from whole filefish were 81.08% and 87.41% and the lipid contents of the two protein preparations were 0.43% and 0.45% respectively. 6. Higher calcium content was found in the protein concentrate rather than in the protein isolate. No sodium and potassium in the protein isolate were detected while the fish concentrate appeared to contain a considerable amounts of both elements. 7. The functional properties, such as suspended solids, wetability, emulsion stability and foam viscosity of the filefish protein isolates were proved to be higher than those of the protein concentrate.

• Science of Emotion and Sensibility
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• v.20 no.2
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• pp.171-178
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• 2017

'Smart Sensibility Mat (SSM)' was developed and manufactured for positive sensibility of newborn with fiber, digital, and sensibility technology to reflect features and advantages of kangaroo care. For tactile stimuli, the tube of the silicon material to provide a constant temperature of $32^{\circ}C$ was inserted into the mat and connected to the water-thermostat. To provide a uniform temperature throughout the mat, the fabric by the inserting conductive yarn was attached to the mat surface. After wrapping the mat with cotton pad, the polyurethane foam used as medicine in order to similar to the human skin was bonded to the surface of the mat. To provide the auditory stimuli of a level of 30dB with mother's heartbeat sounds and voice recorded in advance, the Bluetooth speaker was inserted into the mat. To investigate the effects of SSM, 10 newborns who born within two weeks were involved in this experiment. While the baby was lying on each of the general mat (GM) and SSM, the baby's physiological signals-heart rate, breathing rate, temperature- were measured and then, those were conducted t-test to examine the difference between the signals of SSM and GM. The results were as follows: heart rate (t=8.131, p<.001) and respiratory rate (t=7.227, p<.001) among the physiological signals of SSM decreased significantly than GM within the normal range. Temperature (t=1.062, p=0.292) at SSM showed a tendency to decrease than GM within the normal range. This means the tactile stimuli and the auditory stimuli providing from SSM give stable physiological responses. Thus, SSM leads to have psychological comfort and stability of newborns.

• Journal of the Korea Institute of Building Construction
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• v.19 no.6
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• pp.539-547
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• 2019

Recently, the international community signed a climate change agreement to prevent global warming. Yet currently, the fossil fuels have been widely used in to supply building energy for cooling and heating. The Green Building certification (G-SEED), an energy efficiency rating for new or existing buildings requires that buildings meet certain conditions. Insulation is used as a building material to reduce the energy supply to buildings and to improve the thermal insulation, and it accounts for more than 90% of the total heat resistance provided by the building surface components that meet the energy-saving design standards of new buildings. In this investigation, a performance evaluation study was conducted through an experimental study by directly extracting the foam polystyrene insulation on-site during the remodeling of a building that was in the range of 22~38 years old. Through tests, it was found that the thermal conductivity of the extrusion method insulation (XPS) was reduced by 48% and the compressive strength of XPS decreased by 36% compared to KS M 3808, which is the initial quality standard. For bead method insulation (EPS) with a thickness of 50mm, the thermal conductivity, the compressive strength, and flexural failure load were similar to the initial quality standard. Therefore, in the calculation of the primary energy requirement per unit area per year, the performance of bead method insulation can be estimated simply by considering the thickness of the insulation, while a correction factor that considers its performance deterioration should be applied when extrusion method insulation is used.

• Resources Recycling
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• v.24 no.1
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• pp.58-65
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• 2015

Although Korea is a top market sharing and world leading producer and developer of flat panel display devices, relevant recycling technology is not up to her prestigious status. Besides, most of the waste glass arising from flat panel displays is currently land-filled. The present paper mainly reviews on development of recycling systems for waste TFT-LCD glass from end-of-life LCD TVs and monitors and TFT-LCD process waste of crushed glass particles with target end uses of raw material for high strength concrete pile and glass fibers, respectively. Waste LCD glass was recycled to fabricate ingredients for high strength concrete piles with enhanced physical properties and spherical foam products. The waste LCD glass recycling technology is already developed to fabricate long and short fibers at commercial level. In view of these, future R & D on waste LCD glass materials is to be directed toward implementation of commercial materials recycling system therefrom.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.5
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• pp.506-519
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• 2017

This study evaluated the protein recovery and functional properties and biological activity of boiled and steamed process water (BPW and SPW, respectively) generated from the preparation of concentrated roe of bastard halibut (BH; Paralichthys olivaceus), skipjack tuna (ST; Katsuwonus pelamis), and yellowfin tuna (YT; Thunnus albacares) using the cook-dry process. The protein loss from the water extracts (EXT) of 100 g of roe protein was 15.05-19.71% and was significantly (P<0.05) higher than that of BPW (5.47-10.34%) and SPW (3.88-8.18%). The foam capacity of BPW (166-203%) and SPW (15-194%) was better than that of EXT. The emulsifying activity index of the original samples was lower than those ($15.40-107.86m^2/g$) of diluted protein samples. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and the reducing power of BPW and SPW were stronger than those of EXT. The 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid ($ABTS^+$) radical scavenging activity of EXT (0.028-0.045mg/mL) was significantly higher those of BPW and SPW. The angiotensin I-converting enzyme (ACE) inhibitory activity of SPW was the highest for BH (1.04 mg/mL), followed by YT and ST. The predominant amino acids in SPW were Glu, Ala, Leu, and His. These results demonstrate that processing water containing diluted organic components, including protein, can be consumed directly by humans as a functional reinforcing material after appropriate concentration processes.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.26 no.2
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• pp.77-83
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• 2020

A series of foamed plastic sheets containing biomass (as HMR container) were developed via different foaming process temperatures, and their density, porosity, WVTR, and pore morphology were evaluated. Thermal stability of samples during re-heating the food in oven, change in morphology, density, porosity, and WVTR were investigated using a simulated thermal shock process according to MIL-STD-883E assay. As such, the pore size of samples was generally increased with increasing temperature of the foaming process. It can be explained that as foaming temperature increased, the viscosity of molten resins and the repulsive force against pore expansion decreased. In addition, an increase in the thermal shock cycle reduced the pore size and WVTR, while density increased because high temperature treatment that softened the sheet matrix was followed by a low temperature incubation, which contracted the matrix, thereby changing the physical and morphological properties of samples. However, an insignificant change in density was observed and WVTR tended to be decreased, indicating that as-prepared foamed plastic sheets could be used as a high thermal stable container for HMR application. Therefore, it found that the properties of newly developed HMR containers containing biomass were dependent on the foaming process temperature. Moreover, to better understanding of these newly developed containers, further investigations dealing with foaming process temperature based on various food items and cooking conditions are needed.

• Composites Research
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• v.30 no.6
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• pp.384-392
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• 2017

Sandwich panels with three different joint configurations were tested to design a novel sandwich joint structure that can effectively support both the tensile and compressive loads. The sandwich core was mainly aluminum flex honeycomb but the PMI foam core was limitedly applied to the ramp area which is transition part from sandwich to solid laminate. The face of sandwich panel was made of carbon fiber composite. For configuration 1, the composite flange and the sandwich panel were cocured. For configurations 2 and 3, an aluminum flange was fastened to the solid laminate by HI-LOK pins and adhesive. The average compressive failure loads of configurations 1, 2, and 3 were 295, 226, and 291 kN, respectively, and the average tensile failure loads were 47.3 (delamination), 83.7 (bolt failure), and 291 (fixture damage) kN, respectively. Considering the compressive failure loads only, both the configurations 1 and 3 showed good performance. However, the configuration 1 showed delamination in the corner of the composite flange under tension at early stage of loading. Therefore, it was confirmed that the structure that can effectively support tension and compressive loads at the same time is the configuration 3 which used a mechanically fastened aluminum flange so that there is no risk of delamination at the corner.

• Journal of Korean Society of Steel Construction
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• v.16 no.5 s.72
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• pp.609-619
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• 2004

An investigation was conducted on the activities around Europe in order to solve the problem of the thermal bridging of steel studs, which had caused a significant disadvantage. This study included the following: diminishing the contact area between the studs and the sheathing, lengthening the heat transfer route, replacing the steel web with a less conductive material, and placing foam insulation in locations where the thermal shorts are most critical. Although energy efficiency is usually the focus of such foreign cases because their stud application is mostly limited to low-rise residential buildings, both structural and thermal performance are taken into consideration in this study because these target middle-story buildings. A hybrid stud composed of steel and polymer was also developed. This hybrid stud, which is 150 SL in size, is made of a galvanized steel sheet (SGC58) and a glass fiber reinforced polymer (GFRP) withepoxy bonding. A total of 32 specimens were manufactured. Its parameters comprise two types of connection detail,s: the thickness of steel (1.0mm and 1.2mm) and of the GFRP (4mm-4ply and 6mm-6ply), and the ratio of the length to the depth (L/D = 3, 6, 9, 12). Steel stud specimens with the same conditions were compared to the hybrid stud. The test revealed that in the case of the steel specimen with a thickness of 1.0mm, the maximum load of hybrid studs increased an average of 1.62 times comparedto that of the steel stud. In the case of the steel specimen with a thickness of 1.2mm, on the other hand, the average increase was 1.46times. All specimens showed full composite action until the collapse.

• Journal of Convergence for Information Technology
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• v.9 no.5
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• pp.158-164
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• 2019

Recently many studies to reduce the noise of dental hand piece which generate inevitably mechanical sound to offend to the ear of a patient have been spotlighted. Generally, methods of adding a sound absorbing material inside the exhaust valve, air pump of machine or automobile are widely reported as optimal way to reduce the mechanical noise. In this paper we studied a new UV laser aided manufacturing of micro-porous structure of EPP substrate and applied dental hand piece to improve the efficiency of sound absorption. A lot of micro-sized pores were fabricated with UV laser processing on the surface of sliced EPP substrate. From fundamental experiments, more high-performance of micro-porous EPP substrate has finally demonstrated for sound-absorbing structure of the micro muffler inside dental hand piece, which actually has the excellent potential to apply a lot of potable machine.