• The Research Journal of the Costume Culture
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• v.31 no.5
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• pp.692-704
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• 2023

This study analyzed 214 sports knee braces found on Chinese websites between October 2022 and November 2022 to assess product type (impact protection material, fastening method, and protection method), material composition, size, weight, and main characteristics. The product type was further categorized according to (1) use of hard guard and soft guard protection method; (2) cover type, strap type, and slip-on type fastening method; and (3) pressure type and support type protection method. It also noted the physical shock protection materials used, including foam (EVA or polyurethane) attached to joints as a buffer material and plastic (TPU or PP) that protects the user's knee from external impacts. The study found that the materials that primarily comprise sports knee braces are a combination of nylon, polyester, and neoprene. Additionally, it found that most sports knee braces available on the market are available in three sizes based on knee circumference: M (35-38cm), L (38-41cm), and XL (41-44cm), while some products are available in one size only. Furthermore, the majority of the 214 products studied weighed 200g, followed by 1,000g. Finally, in terms of product characteristics, many sports knee braces utilize ring-shaped silicone pads to distribute the load pressure on the knees or incorporate sturdy adhesive velcro to improve knee stability.

• Conservation Science in Museum
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• v.7
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• pp.11-24
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• 2006

Plate armour is an important cultural property that reflects the ancient weaponry and the manufacturing technology of ironware as they are. Among the kinds of iron armour, horizontal plate armour has been very rarely excavated, and there are a few artifacts in their unimpaired shape like the plate armour excavated from Mangisanseong. This report reviews the manufacturing technology of ancient plate armour through its radiograph using appliable nondestructive irradiation and scientific conservation treatment. The seven-tiered plate armour excavated from Mangisanseong has ring hinge to open and shut the right side neck guard. The readout result of radiograph proved iron safety guard of Godaepan (a plate that links neck plate and horizontal plate) and leather safety guard of the right armpit with plate overlap and perforation interval; perforations that seem to have linked shoulder strap on wearing the armour are also observed. In particular, it is identified that the perforation and riveting technique avoided the connection of more than three plates with a rivet. This is an important material to illustrate the best use of function of plate armour overcoming its limit.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.2
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• pp.240-245
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• 2016

This paper describes the rheological behavior study such as viscosity and change of shear stress regarding marine lubricating oil according to the amount of Marine Gas Oil (MGO) dilution. The viscosity reduction due to fuel dilution is crucially important characteristic to decreasing engine durability because of the abrasion of piston ring or liner. The lubricating oil used in this paper was blended with magnetic stirrer diluted High Sulfur Diesel (HSD, 0.05 wt%) ratio of 3 %, 6 %, 10 %, 15 % and 20 %. The viscosity and shear stress of diluted lubricating oil were measured with the temperature range from $-10^{\circ}C$ to $80^{\circ}C$ using a rotary viscometer (Brookfield Viscometer). As the amount of MGO dilution increasing in lubricating oil, the viscosity and stress of those decreased, because the lubricating oil diluted MGO with low viscosity show the trends to decreased viscosity and shear stress. Especially, the viscosity and shear stress of lubricating oil radically decreased at low temperature ($0{\sim}-10^{\circ}C$) and doesn't effect in MGO dilution at over $40^{\circ}C$. As temperature risen, the reduction of the viscosity and shear stress in lubricating oil shows the Newtonian behavior. The lubricating oil was required to check up periodically to improve engine durability since the viscosity reduction by MGO dilution accelerating the engine abrasion.

• Korean Security Journal
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• no.58
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• pp.177-194
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• 2019

Last year, the Moon Jae-In administration made an attempt to abolish the presidential security office overseeing the presidential security and to transfer the work to the presidential security service under the National Police Agency. Currently, all of the G7 nations maintain a security system spearheaded by the police, so the policy of transferring the presidential security to the National Police Agency may be discussed. However, it is necessary to focus on the following reality. First, the current presidential security system is consisted of the overlapping security organizations classified into (1) inner ring of the presidential security agency, (2) middle ring of the police agency, and (3) outer ring of the capital defense command. If the presidential security agency is abolished, a vacuum will result as per the principle of class. Second, for the efficient security guard of the President, currently, the presidential security agency at the Presidential Security Safety Measure Committee plays the role of coordinating the tasks. If the National Police Agency becomes the control tower of the presidential security, whether command will be available for the military and diplomatic aspects of the presidential security work should also be considered. Third, Korea is currently in a truce with North Korea, so there is a big difference in terms of the security environment with such G7 nations as the UK, Germany, France, and Japan.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1829-1831
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• 2004

This paper described the capacitive sensor for the diagnosis of deterioration of electrical insulating oils applying guard-ring type the 3-terminal electrodes. To measure stable capacitance of the sensor and to determine the design factors of the sensor, we utilized computational analysis, FEM software. This capacitive sensor discern the extent of deterioration measuring relative permittivity of electrical insulating oils. The result of measuring numerous sample, mineral oils, as serviced year, we confirmed an increase in relative permittivity of oils. Moreover, we confirmed the superior characteristics of the sensor as a species, aged pattern of oils and operating temperature.

• Proceedings of the IEEK Conference
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• 2000.06b
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• pp.270-273
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• 2000

We have fabricated and analyzed photodiodes for optical link with Si pin structures. As the results of experiment, the web patterned photodiode(type C) with $p^{+}$-guard ring showed low junction capacitance of 6~7 pF at $V_{R}$=-5V and high separation ability for optical signal(dark current : $\leq$ 5 nA, optical signal current : $\geq$ 340 nA) due to the small effective $p^{+}$-n junction area and the expanded electric field region. The fabricated Si pin photodiode can be applicable for detecting an optical signal with the wavelength of about 660~670 nm. It can also be integrated with the twin well CMOS structure to develope an one chip based optical receiver IC. IC.C.

• KIEE International Transactions on Electrophysics and Applications
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• v.12C no.4
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• pp.214-219
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• 2002

The influence of ultraviolet (UV) irradiation and corona on the surface degradation of high temperature vulcanized (HTV) silicone rubber used for outdoor insulation through measuring surface voltage decay after corona charging, surface resistivity, contact angle and X-ray photoelectron spectroscopy (XPS) analysis was studied. The surface resistivity calculated by the surface voltage decay was compared with a value directly obtained from the three electrode method having the guard ring electrode. A good agreement between the two methods for surface resistivity was obtained. UV treated specimens showed the slower decrease of surface voltage decay, while the corona exposed specimens showed a dramatically faster decrease. Although both artificial treatments cause the same oxidative products, which was confirmed with XPS, we could distinguish the difference between the reactions of the two treatments by monitoring the surface voltage decay on corona-charged specimen. In addition, we could derive the specific surface states of the silicone rubber treated by accelerated artificial aging factors and the degradation process.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1503_1504
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• 2009

MEMS 구조물은 ${\mu}m$단위의 크기로 만들어지므로 각속도계와 같이 정밀한 센서를 만들 때에는 노이즈 문제를 해결하지 않으면 신호를 측정할 수가 없다. MEMS 구조물의 미세한 진동에 의해 발생되는 수 pico-coulomb의 전하를 측정해야하므로 구동 신호가 검출 전극에서 Feed-through되어 나타나는 경우 그 크기가 구동에 의한 신호보다 100배 이상 크기 때문에 원하는 신호를 검출할 수 없다. 본 논문에서는 이러한 Feed-through 현상에 의한 노이즈를 줄이기 위하여 Guard-ring을 이용한 blocking 방법과 dummy port를 이용한 canceling 방법을 고안하고 Feed-through reduction 회로를 설계, 제작, 실험하여 그 효과를 확인하였다. 그 결과 구동신호가 6Vpp, 30kHz일 때, -53.186dBm이었던 Feed-through 신호가 -77.107dBm으로 줄어드는 것을 확인하였다. 또한 노이즈를 제거하지 않은 경우 측정할 수 없었던 Q-factor를 Feed-through reduction 회로를 사용하여 측정한 결과 진공 패키징된 Si 기반 자이로스코프가 공진주파수 약 7.018kHz에서 Q-factor가 약 2500임을 확인하였다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.1
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• pp.53-56
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• 2008

The commercial parallel plate electrodes system with guard-ring electrode have been widely used for measurement of dielectric constants of solid materials. And the specification of the electrodes system is about 1 % of measurement uncertainty. This measurement uncertainty is only estimated the error come from mechanical measurements such as the area of the electrodes and the gap between the electrodes except the error come from the air gap between the electrodes and dielectric specimen. Because it is impossible to measure the air gap. This study analyze the total measurement uncertainties of the commercial dielectric constant test cell using 3 kinds of Standard Reference Materials. As a results, the total measurement uncertainty is much bigger than 1 % and the most of the uncertainty can be reduced by compensation of the error values evaluated in this study.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.168-171
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• 2002

A SSIMT(Suppressed Sidewall Injection Magnetotransistor) sensor with high linearity is presented in this thesis. The prototype is fabricated by using the Hynix 0.6$\mu\textrm{m}$ P-substrate twin-well double poly three-metal CMOS Process. The fabricated SSIMT shows that variation of the collector current is extremely linear by varing the magnetic induction from -200mT to 200mT at I$\_$B/=500${\mu}$A, V$\_$CE/=2V and V$\_$SUB/=5V. The relative sensitivity is up to 120%/T. At B = 0, magnetic offset is about 79mT, there relative sensitivity is 30.5%/T. The nonlinearity of the fabricated SSIMT is measured about 1.4%.