• The Korean Fashion and Textile Research Journal
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• v.20 no.5
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• pp.569-582
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• 2018

The purpose of this study is to verify the impact protection performance and to evaluate the activity, design, fit, and pad characteristics of the fall impact protection clothing for elderly women. The protective clothing was designed as pants type and underwear type, and an impact protection pad in the form of a tightly connected regular hexagon piece was inserted in the hip and hip joints. The pad was made of two kinds of foam single pad and foam and gel combination pad so that they could be inserted into pants type and underwear type, respectively. The results of the shock absorption performance of the fall impact protective clothing showed that when the impact force of 4601N was applied to the pants type protective clothing, the impact force was reduced by 29% in the foam pad type and 26% in the gel and foam pad type. When the force of 5113N was applied to the underwear type, it decreased by 40% in the foam pad type and by 34% in the gel and foam pad type. As a result of wearing evaluation of subject group, it was found that fit and activity of underwear type was better than that of pants type. Foam pad type was evaluated to be lighter than gel and foam pad type in both the subject and the expert group and the gel and foam pad was evaluated to be more flexible in the expert group.

• The Korean Fashion and Textile Research Journal
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• v.20 no.4
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• pp.422-428
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• 2018

In this study, we developed honeycomb pads using foam and polymer gel and verified the impact protection performance of pads for the development of a fall protection pants for elderly women aged 65 and over who have a high risk of fracture due to falls. The results are as follows; In the first experiment, the impact protection performance was evaluated for four honeycomb pad samples (CR foam, EPDM foam, hardness 15 polymer gel, and hardness 30 polymer gel) manufactured to a thickness of 5 mm using a single material. When the force of about 10757N was applied to the specimens, all four pads reduced the impact force to 3100N or less. Polymer gels showed better protection than foam materials. In the second experiment, the thickness of the protective pad was set to 8 mm in order to improve the shock absorbing performance of the protective pad. As a result of evaluating the impact protection performance of the foam single pad and foam gel composite pad, the impact absorbing performance of the foam single pad was better. Finally, four kinds of protection pads were made by assigning the foam single pad and the foam gel composite pad to pants type and underwear type respectively. The pad thickness of the main protection area was set to 8 mm to enhance the protection, and gradually decreased to 5mm and 3mm toward the edge to improve the appearance and fit.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.3
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• pp.161-168
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• 2014

This study conducted a comparative analysis of the contraction pattern of trunk and lower limbs muscles of handicapped children with brain lesions during the use of foam pad and air pad for fixing a standing table to the body for pediatric patients with brain lesions using a standing table product applied with a pneumatic air fitting system. There was a difference in the measurement of muscle strength activity by muscle in accordance with pad type (foam pad vs. air pad). A large difference was found with big movements (movements of eating), while a small difference was discovered with small movements (writing and reading movements). This was found to furnish a little more comfort to users compared with the existing foam pad during the use of a standing table product applied with a pneumatic air fitting system.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.5
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• pp.843-852
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• 2020

Among the many packaging materials used in cushion packaging, there is a lack of optimum design for packaging trays and cushion pads used in pear packaging for export and domestic distribution. It causes over-packaging due to excessive material input, and can be solved by applying various parameters needed to optimize the design of the packaging tray and cushion pad considering the packaging material and the number of pears in the box. In the case of a cushion pad for pears, the economic efficiency of material and thickness should be considered. Therefore, it is possible to design a packaging tray and cushion pad depending on eco-friendly packaging materials (PLA, PET) used by applying appropriate design parameters. The static characteristics of the materials used for the packaging of pears were analyzed using FEA (finite element analysis) simulation technique to derive the optimal design parameters. In this study, we analyzed the contact stress and deformation of PET, PLA tray (0.1, 0.5 1.0, 1.5 and 2 mm) and PET foam (2.0, 3 .0 and 4.0 mm) with pears to derive appropriate cushion packaging design factors. The contact stress between the pear and PET foam pad placed on PLA, PET trays were simulated by FEA considering the bioyield strength (192.54±28 kPa) of the pears and safety factor (5) of packaging design, which is the criterion of damage to the pears. For the combination of PET tray and PET foam buffer pad, the thickness of the PET foam is at least 3 mm, the thickness of the PET foam is at least 1.0 mm, the thickness of the foam is at least 2 mm, and if the thickness of the PET tray is at least 1.5 mm, the thickness of the foam is at least 1 mm, suitable for the packaging design. In addition, for the combination of PLA tray and PET foam pad, the thickness of the PET foam was not less than 2 mm if the thickness of the PLA tray was 0.5 mm, and 1 mm or more if the thickness of the PLA tray was not less than 1.0 mm, the thickness of the PET foam was suitable for the packaging design.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.34-40
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• 2016

In ventilated seats for cars, air flow is generated by a fan and passed through a foam pad, foam filter, and seat cover. There is a significant loss of air flow in this process, and it is not easy to analyze the amount delivered to the driver. Another difficulty is the geometric complexity of the air flow passage inside the seats. In this paper, the air flow through a foam pad was analyzed. Proper modeling of the bumps in the ventilation mat was found to be important in the analysis. Air flow is lost when it passes through the porous pad foam, which was measured and used to correct the analysis results. The corrected analysis results were in a good agreement with the experimental results. The amount of air flow delivered to a driver was measured using an airflow cone. Only 35.7% of the air flow from the fan was delivered.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.4
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• pp.337-345
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• 2009

This paper investigates the reliability of district heating pipes at thermo-elastic fatigue loading. District heating pipes, subjected to $120^{\circ}C$ and $16kg_f/cm^2$ due to water distributing service through inside the pipes, should endure long term cyclic thermal-mechanical loadings. The heating pipes are the co-centric tubes of steel pipe, poly urethane(PUR) insulator, and high density poly ethylene(HDPE) case. On installation, foam pad is externally wrapped for accommodating stress reduction near the bend sections of pipes. However, there have been frequent reports on the failures of bend sections in the middle of long term service. This study scrutinizes the observed failures near the bend sections through applying the finite element methods. Specially in this study, heating pipes are studied on the influence of foam padding on failures and proposed new designs for reinforced bend without foam pad.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.3
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• pp.245-252
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• 2016

In this study, an alternative bend design is proposed to overcome the aging problem in piping bends. In this design, the foam pad is not included. Finite element analysis was performed based on the total pipe diameter. From this analysis, the shape of the Shear Control Ring (SCR) was determined. Temperature, stress, and other data of the proposed reinforced pipe were acquired and analyzed after the test was performed. The value of the thermal stress for the reinforced steel pipe satisfied the required standard without the foam pad based on the manufacturing of the reinforced fitting and construction site of the test. The reinforcement provided a shear strength level for the foam pad that resulted in maximum shear stress less than stress based on the original foam pad applied at the pipe bend. Additionally, an increasing factor of safety effect for the reinforced fitting application was discovered.

• Journal of the Korean Society of Clothing and Textiles
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• v.40 no.3
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• pp.495-505
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• 2016

This study explores and selects an appropriate material that considers light and soft physical properties as well as activity for impact absorption pads that can be used to develop practical impact protective clothes worn during daily life by the elderly to reduce the impact of falls. Physical properties, impact absorption performance, and compression characteristics were evaluated on 5 types of foam, 2 types of 3D spacer fabric, and 3 types of polymer gel to select a material appropriate for the pad to be inserted into impact protective clothes. The evaluation of the physical properties showed that 3D spacer fabrics had lower density compared to other materials and polymer gels had the highest density. The elongation percentage was higher in foams than 3D spacer fabrics and EPDM foam had the highest elongation percentage. The impact absorption performance of honeycomb polymer gel was better than foams and 3D spacer fabrics. As a result of looking into compression energy and compression characteristics of materials, 'CR foam A' was found to absorb the largest amount of compression energy, 24.1%, among foams and polymer gels. A high energy absorption rate of 50.0% (or above) was indicated by 3D spacer fabrics; however, foams and polymer gels showed a progressive deformation of energy compression / recovery curve with 3D spacer fabrics that showed drastic deformation. Based on characteristics of materials, 'CR foam C' and EPDM with relatively high absorption performance can be used as protective pad materials among foams. Among polymer gels, 2 open-type polymer gels that have relatively low impact protective performance but a relatively lighter weight on human body (compared to closed-type) are considered appropriate protective pad materials.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.434-437
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• 2005

Chemical Mechanical Polishing (CMP) has become an essential step in the overall semiconductor wafer fabrication technology. In general, CMP is a surface planarization method in which a silicon wafer is rotated against a polishing pad in the presence of slurry under pressure. The polishing pad, generally a polyurethane-based material, consists of polymeric foam cell walls, which aid in removal of the reaction products at the wafer interface. It has been found that the material removal rate of any polishing pad decreases due to the so-called 'pad glazing' after several wafer lots have been processed. Therefore, the pad restoration and conditioning has become essential in CMP processes to keep the urethane polishing pad at the proper friction coefficient and to allow effective slurry transport to the wafer surface. Diamond pad conditioner employs a single layer of brazed bonded diamond crystals. Due to the corrosive nature of the polishing slurry required in low pH metal CMP such as copper, it is essential to minimize the possibility of chemical interaction between very low pH slurry (pH <2) and the bond alloy. In this paper, we report an exceptional protective coated conditioner for in-situ pad conditioning in low pH Cu CMP process. The protective Cr-coated conditioner has been tested in slurry with pH levels as low as 1.5 without bond degradation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.425-430
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• 2000

This paper describes the effect of the pad stiffness on the noise reduction of impact noise isolation pads of a floor. And also a new semi-experimental method for measuring the impact noise isolation capability of a pad is introduced. The impact noise isolation pads made of wire-mesh, urethane-chip and foam rubber are used for measuring the stiffness, the vibrational insulation performance and the impact noise isolation capability. The correlation between the stiffness and impact noise isolation capability of pads is theoretically reviewed, and confirmed from the experimental results. For measuring the impact noise isolation capability of only an isolation pad, a semi-experimental method proposed in this study is more effective than the reverberation room method.