• Fashion & Textile Research Journal
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• v.25 no.2
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• pp.221-229
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• 2023

This study aims to develop knee protectors that provide high safety and fitness, while incorporating a motion-adaptable 3D-printed pad. These protectors were evaluated by individuals who experience knee discomfort or pain. The results are as follows. First, the 3Dprinted pad design of a hexagonal mesh structure, which is modeled for excellent appearance and knee movement. Each unit of the mesh has a outer layer of 2mm thick, a spacer layer of 1 mm in diameter, and is connected by a 1.5 mm bridge. The bridge was extended up to 1.2 cm. Second, the knee brace was designed in three types - cylinder, strap, and combination by Universal design. Impact protection measurements of the three knee protectors demonstrated roughly 80% reduction in impact. Third, based on usability evaluation, cylinder type protectors have the highest ratings in most areas, primarily because of their ease of use. The strap type protector received positive reviews in terms of appearance and care, and the combination type provided stable knee protection. This study demonstrated the potential industrial application of 3D printing technology by designing and evaluating protective products for the human body. The results of this study are expected to aid knee protector manufacturers in developing practical products and promoting the development of protective equipment for other body parts or purposes.

• Journal of Radiation Protection and Research
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• v.45 no.1
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• pp.45-52
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• 2020

Background: Recently, the International Commission on Radiological Protection (ICRP) lowered the dose limit for the eye lens from 150 mSv to 20 mSv, highlighting the importance of accurate lens dose estimation. The ICRP reference computational phantoms used for lens dose calculation are mostly based on the data of Caucasian population, and thus might be inappropriate for Korean population. Materials and Methods: In the present study, a detailed Korean eye model was constructed by determining nine ocular dimensions using the data of Korean subjects. The developed eye model was then incorporated into the adult male and female mesh-type reference Korean phantoms (MRKPs), which were then used to calculate lens doses for photons and electrons in idealized irradiation geometries. The calculated lens doses were finally compared with those calculated with the ICRP mesh-type reference computational phantoms (MRCPs) to observe the effect of ethnic difference on lens dose. Results and Discussion: The lens doses calculated with the MRKPs and the MRCPs were not much different for photons for the entire energy range considered in the present study. For electrons, the differences were generally small, but exceptionally large differences were found at a specific energy range (0.5-1 MeV), the maximum differences being about 10 times at 0.6 MeV in the anteroposterior geometry; the differences are mainly due to the difference in the depth of the lens between the MRCPs and the MRKPs. Conclusion: The MRCPs are generally considered acceptable for lens dose calculations for Korean population, except for the electrons at the energy range of 0.5-1 MeV for which it is suggested to use the MRKPs incorporating the Korean eye model developed in the present study.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1529_1530
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• 2009

The process conditions for fabricating p-type silicon pillars were optimized by controlling current density, bath temperature. To get best process flexibility for pillar arrays formation, three factors affecting pillar formation were changed. First, the solution bath was designed to keep constant temperature during the experiment irrespective of external temperature. Second, the counter Pt electrode was changed from rod type to mesh to obtain uniform distribution of current density. Third, Cr-Cu alloy electrode instead of Cu was used to increase electrode current density.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.826-829
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• 1995

The oil-pressure type torque sensor has been adopted in steering system of major automobiles. However, it has been well known that this type of torque sensor needed many subcomponents and produced inaccurate responses. This paper intends to suggest new type of torque sensor based on the shape design by using finite element. A dedicated mesh generation, analysis and post result display program has been developed. As for shape design purpose, the half shape of torque sensor is considered. The result of this study has shown that the design automation for precise torque sensor for control of high velocity rotation shaft can be achieved whithout any expensive investment to the design software.

• Environmental Analysis Health and Toxicology
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• v.4 no.3_4
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• pp.29-59
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• 1989

For the purpose of electrolytic treatment of wastewater containing various heavy metals, the BPBE Cell of batch and continuous type was considered and experimented. Some results from this study were summarized as follows: 1. When the artificial wastewater containing 500 mg/l of the concentration of various heavy metallic ion was electrolyzed in BPBE Cell of batch type, the removal efficicency was over 95% in cadmiun (II), lead (II), chromium (Ⅵ) and over 85% in copper (II), chromium (III). 2, As granular activated carbon packed in BPBE Cell, coconut shell was superior to lignite and the removal efficiency was the highest when the activated carbon was 4/6 mesh, the voltage was 20V. 3. When the heavy metallic ion in wastewater was electrolyzed in BPBE Cell of continuous type, about 1,000mg of heavy metal per 1kg of coconut sell could be removed. 4. The treatment method of heavy metallic ion in wastewater by BPBE Cell cost less than in the former chemical treatment method and the coconut shell packed in BPBE Cell could be regenerated by chemical method.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.17 no.4
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• pp.221-237
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• 2013

In this paper an asymptotic numerical method named as Initial Value Method (IVM) is suggested to solve the singularly perturbed weakly coupled system of reaction-diffusion type second order ordinary differential equations with negative shift (delay) terms. In this method, the original problem of solving the second order system of equations is reduced to solving eight first order singularly perturbed differential equations without delay and one system of difference equations. These singularly perturbed problems are solved by the second order hybrid finite difference scheme. An error estimate for this method is derived by using supremum norm and it is of almost second order. Numerical results are provided to illustrate the theoretical results.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.148-153
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• 2000

An experimental study was conducted to investigate an isothermal characteristics of the condenser surface of disk type heat pipe using PF 5060 and FC 40 as working fluids. Desired temperature range at the condenser surface was $90^{\circ}C{\sim}130^{\circ}C$, which was cooled by natural convection. The operating temperature, the height of vapor space, the wall thickness of condenser, and the existence of a wick structure were considered as experimental factors. The temperature difference and the temperature fluctuation at the condenser surface were analysed to describe the performance of the heat pipe.

• International Journal of Railway
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• v.9 no.1
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• pp.15-20
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• 2016

An approach section on an abutment is located between the soil embankment and the structure, which may cause an uneven surface due to different settlement between the abutment and the soil embankment. This study proposes a new type of wall which separates the abutment from the backfill material using mechanically stabilized wall. A new type of keystone which incorporates geotube and wire mesh is proposed and evaluated. Numerical analyses were performed to investigate the applicability of the proposed keystone type, which incorporates Geosynthetic. The maximum horizontal displacements along GRS wall faces, settlements at the top of pavement and track bed, and tensile forces applied on geotextiles under traffic loads were investigated. The results of the numerical analysis showed that the proposed wall can be used for highway and high-speed railway abutment.

• International Journal of Ocean System Engineering
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• v.3 no.2
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• pp.90-94
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• 2013

This study represents the recent laboratory results from cathodic protection (CP) system with the use of sacrificial anodes at different environmental conditions (temperature of $10^{\circ}C$ and $40^{\circ}C$). Specimens were slab type with a dimension of $500mm{\times}50mm{\times}100mm$, and concrete cover thickness were 25mm. Zinc mesh and/or bulk type anodes were installed at the center of specimen to confirm the distance that CP system has influences on the specimen to distribute uniform CP current to rebar. Two different kinds of temperature condition were applied to verify the effect of temperature. Experiments were conducted for 60 days, and the distribution of potential and current that supplied from anode to rebar was measured. From the results, CP potential was varied with time, and temperature played an important role in CP potential variations. Current was also changed with time, and current distribution could be improved by installing additional bulk type anode.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.10 no.2
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• pp.81-89
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• 1981

Experimental results for convective heat transfer from a number of screen type heat storage materials, made of stainless steel and brass, were obtained by the use of the transient technique. The effects of the material, the size of mesh, and the number of screens. on the heat transfer coefficient could not be detectable A dimensionless correlation describing the convective heat transfer from the screen type heat storage materials is given in the range of Reynolds number between 60 and 1000.