• 한국의류산업학회지
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• 제16권6호
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• pp.1001-1007
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• 2014

We surveyed the wearing characteristics of hip protectors. The problems of existing hip protectors were identified and the directions for improvement were presented. The evaluation of wearing characteristics was conducted on the 100 elderly women (60 to 85 years) with 5 types of hip protector. The questionnaire was composed of history and characteristics on falling, hip protector acceptance, preference, use characteristics and improvement requirements. The result of wearing characteristic evaluation indicated that 52% of the subject experienced falling in winter. Incidents resulting from falling occurred: outdoors (74.5%), bathroom (10.9%), and kitchen (5.5%). Body parts to be protected were in several areas: 35.6% for lumbar, 26.9% for hip joint, and 15% for hip bone. Participants prefer a belt B type design at a rate of 56.9% because it provided a sense of stability by clinging to the body and upholding the waist. Belt B type was the most appropriate in terms of fit, allowance, mobility, and design except pad thickness. To reduce the risk of hip fracture, hip protector needs to be designed in consideration of user's type of fall and body shape. The pattern and size of a hip protector has to be improved in regards to the amount of discomfort. An objective evaluation is needed for the ergonomic design of a hip protector based on and analysis of 3D body image of the elderly and the shock-absorbing quality of pad.

• 한국의류산업학회지
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• 제22권3호
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• pp.368-377
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• 2020

This study provided basic data to develop functional and fitness cycling wear for cyclists. We analyzed the domestic and overseas cycling wear brand patterns for tops and tights as well as compared pads attached to tights. The results were as follows. The tops of the cycling wear were designed with cutting lines in the lateral or yoke in the back to reflect cycling posture. It is necessary to study if there is a difference in the air resistance or fitness of the athlete. The sleeve hem band affected by arm movement during cycling, proper sewing and band pressure are also important. The tights have a brand that does not insert a band in front of the waist in consideration of the cyclist's breathing. It should take into account methods of constructing a proper garment pressure that does not interfere with cycling. Analyzing the cycling pad indicated that the three-dimensional shape and size of the pad show many differences for each brand, indicating a difference in cycling movement suitability. In addition, many of the cutting lines should account for the productive aspects because of the high consumption of the fabric in order to design a pattern considering the cycling posture.

• Journal of Power Electronics
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• 제18권4호
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• pp.1278-1292
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• 2018

Inductive power transfer (IPT) technology allows for charging of electric vehicles with security, convenience and efficiency. However, the IPT system performance is mainly affected by the magnetic coupling structure which is largely determined by the coupling coefficient. In order to get this applied to electric vehicle charging systems, the power pads should be able to transmit stronger power and be able to better sustain various forms of deviations in terms of vertical, horizontal direction and center rotation. Thus, a novel cross-shaped magnetic coupling structure for IPT charging systems is proposed. Then an optimal cross-shaped magnetic coupling structure by 3-D finite-element analysis software is obtained. At marking locations with average parking capacity and no electronic device support, a prototype of a 720*720mm cross-shaped pad is made to transmit 5kW power at a 200mm air gap, providing a $1.54m^2$ full-power free charging zone. Finally, the leakage magnetic flux density is measured. It indicates that the proposed cross-shaped pad can meet the requirements of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) according to the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA).

• 폴리머
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• 제36권5호
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• pp.643-650
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• 2012

폴리우레탄의 열적 안정성을 개선하기 위하여, poly(oxydiethylene adipate)-diol(PAD), 4,4'-MDI, Cloisite 30B(30B), melamine phosphate(MP)를 사용하여 poly(adipate urethane)(PAU)과 PAU/30B(30B 2.7 wt%), PAU/MP(MP 2.2 wt%), PAU/30B/MP(30B 2.2 wt%, MP 2.2 wt%) 복합체를 합성하고 열분해 특성을 연구하였다. PAU 복합체에서 Cloisite 30B와 MP의 분산을 안정하고 균일하게 유지시키기 위하여, adipic acid와 diethylene glycol의 에스테르 반응 단계에서 Cloisite 30B와 MP를 도입하였다. $250^{\circ}C$ 이하에서 PAU 복합체가 순수 PAU보다 더 빠르게 열분해 되었다. 고온에서는 30B와 MP에 의하여 열안정성이 개선되어 분해속도가 현저히 감소하였으며, $700^{\circ}C$ 잔량도 크게 증가하였다.

• 한국항공운항학회지
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• 제31권2호
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• pp.89-94
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• 2023

Recently, domestic small airport development plans are being promoted centering on islands, and among them, Baengnyeong Island Airport is located very close to North Korea due to its geographical characteristics. In particular, since it is located in the P-518, which is prohibited airspace, it is essential to configure the arrival/departure flight procedure route similarly to the current ship in terms of securing flight safety. Therefore, in this study, a plan for airport location and facility scale was proposed by focusing on the runway operated for the purpose of aircraft operation through consultations with the Ministry of National Defense. It was proposed to meet the standards of the Airport Facility Act as an airport dedicated to domestic flights for airside facilities such as runway length and direction, target aircraft, landing pad, apron, runway and taxiway width appropriate for the topographical characteristics of Baengnyeong Island. As a result, the flight procedure is generally established as a two-way visual flight, but the 10-way arrival/departure procedure was planned to be changed to an instrument (non-precision) according to the specificity of the region. In addition, a flight procedure was established and presented for safe and systematic operation by reflecting the changes in airport facility size (landing pad, runway end safety area, etc.) following the change in instrument flight procedure in the visual flight procedure.

• 한국염색가공학회지
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• 제23권4호
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• pp.304-311
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• 2011

For sound absorption and sound insulation in automobile industry, the sound absorption materials based on meltblown nonwovens were prepared by SMS (spunbond-meltblown-spunbond) technique. And the sound absorption coefficient (${\alpha}$) of the meltblown nonwoven, produced with isotatic-polypropylene(PP), was examined for the various processing conditions such as die-to-collector distance(DCD), nonwoven weight(GSM), and air suction conditions. The meltblown nonwoven for sound absorption materials was composed of bulky microfiber web, increasing with increases in weight and DCD. The sound absorption coefficient(${\alpha}$) was excellent as a sound absorption materials of PAD type composed of SMS(spunbond-meltblownspunbond) nonwovens.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 춘계학술대회 논문집
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• pp.121-126
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• 1993

Tiling pad journal bearing that has high stability is analyzed about air-lubricated bearing that is usually used to need high precision by using the Direct analysis. The pressure that supports the shaft is occured by the differences between the shaft and pads radii of curvatures. So the characteristics of load capacity for their variable values is important. In this paper the load capacity is compared with some the eccentricity ratio values of0.1, 0.2, 0.5, 0.8. The large load capacity comes from large eccentricity ratio, highbearing number and high preload. But if the preload become high too much, then the shaft makes contact with pads.

• Tribology and Lubricants
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• 제18권6호
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• pp.384-388
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• 2002

The adequate design of a passenger car braking system, which is directly related to the safety of a car, is very important since the safety is an essential design parameter of a car to keep men and car from the damage. The thermal behaviors of the ventilated disk has been investigated based on the air cooling effects during repeat braking operations. In this study, the thermal behavior of ventilated disk brake system was investigated by numerical method. The 3-Dimensional unsteady model was simulated by using a general purpose software package “FLUENT” to obtain the temperature distributions of disk and pad. The model includes the more realistic braking method, which repeats braking and release. The effects of aspect ratio of ventilated hole on the heat dissipation was investigated.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 춘계학술대회 논문집
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• pp.362-365
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• 2007

In this paper we present development process and results of some cases for underground pad transformer and switchgear. Some characteristic factors was considered and tested to improve the functions of the case, such as natural convection of cooling air between the internal and external cases, properties of material that used as external panel etc. Proposed designs and functional characteristics will be adapted to making the cases of underground facilities after the elaborated tests. The results obtained from this study will improve the scenery of a street.

• 한국전기전자재료학회논문지
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• 제17권3호
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• pp.283-288
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• 2004

We have fabricated MIM capacitors for MMIC applications, with capacitances as high as 600pF/$\textrm{mm}^2$ and excellent electrical properties of the insulator layer. Silicon nitride thin film is the desirable material for MMIC capacitor fabrication. Standard MIM capacitance in MMIC is 300pF/$\textrm{mm}^2$ with an insulator layer thickness of more than 2000$\AA$. However, capacitors with thin insulator layers have breakdown voltages as low as 20V. We have deposited insulator layers by PECVD in our MIM structure with an air bridge between the top metal and the contact pad. The PECVD process was optimized for fabricating the desired capacitors to be used in MMIC. Silicon nitride(Si$_{x}$N$_{y}$) thin films of about 1000$\AA$ thick show capacitances of about 600pF/$\textrm{mm}^2$, and breakdown voltages above 70V at 100nA.A.A.