• Proceedings of the ESK Conference
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• 1996.04a
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• pp.250-251
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• 1996

인간의 온열환경에 대한 적응은 인간-의복-환경 System사이의 산열과 방열의 열교 환을 통해 보유량을 일정하게 유지하는 항체온 조절에 의해 이루어진다. 이러한 인체와 의 관계와의 열교환은 주로 피부표면을 통해 이루어지므로 피부온은 외계로의 방열을 예측 하여 인간의 체온조절반응을 나타내며, 온열감각을 좌우하는 인자로 의복의 온열생리, 의 복의 보온력, 쾌적성을 평가하는 중요한 생리적인 지표가 되어 착의의 적부를 검토하는 데 의미를 지니면서 의복설게의 기초가 된다. 이에 본 연구는 국내의 기후 및 변화된 온열환경에 적응된 인체의 각 환경기온하에서의 피부온을 기존의 연구와는 달리 장시간의 노출에 의한 변동을 파악하여 쾌적 착의의 관점에서 인체와 환경사이에 존재하는 의복에 있어서 설계의 기초가 되는 피부온의 의의를 재검토함을 목적으로 한다.

• Composites Research
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• v.35 no.3
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• pp.175-181
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• 2022

Due to the increasing number of wireless communication devices in mmWave frequency bands, there is a high demand for electromagnetic interference (EMI) shielding and heat dissipating materials to avoid device malfunctions. This paper proposes an EMI shielding composite film with a high heat dissipation characteristic. To achieve this, a conductive grid is integrated with a polymer-based composite layer including magnetic and heat dissipating filler materials. A high shielding effectiveness (>40 dB), low reflection shielding effectiveness (<3 dB), high thermal conductivity (>10 W/m·K), thin thickness (<500 ㎛) are simultaneously achieved with a tailored design of composite layer compositions and grid geometries in 5G communication band of 26.5 GHz.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.1
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• pp.61-70
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• 2001

As important factors determining human sensorial comfort, liquid moisture management and surface properties of heat resistant workwear materials were examined. To figure out liquid moisture management properties of the test materials, absorption capacity, rate of absorption, and evaporation properties were assessed. A modified GATS(Gravimetric Absorbency Testing System) was used to measure the liquid moisture accumulation associated with the wicking of liquid moisture from sweating skin. The GATS procedure measures demand wettability of materials to take up liquid in a direction perpendicular to the fabric surface and it was modified to incorporate a special test cell and cover to assess absorption behavior in the presence of evaporation. Fabric stiffness, smoothness, number and the length of surface fibers, and an estimate of the contact area between the skin and fabric surface were measured to characterize the mechanical and surface properties of the test materials. Also an estimate of the force with which a fabric clings to moist skin was made using as wet-cling index.

• Fire Science and Engineering
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• v.24 no.2
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• pp.21-30
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• 2010

We have test chemical resistance and flame retardant properties of chemical protective clothing Fabrics by the ASTM and ISO standard methods. The flame retardant test results show that polyethylene is poor in flame resistance but fluoroelastomer add to decabrom is excellent in flame resistance. Especially, nowadays heat protective clothing for firefighters, which is aluminized film layers laminated to aramid fabric, show the excellent flame resistance. However, the chemical resistance test results show that aluminium is high corrosive in 4M NaOH solution alone. The problem of corrosion can be overcome by employing multiple barrier film. Also, based on the result of flame retardant test, duel skin of polymer barrier film add to aluminum film and single skin of fluorinated rubber with flame retardant materials seems to be fit for the chemical protective clothing. Also the thermal protection and heat transfer test results show that TPP and HTI is increased assured that the continued study on fire risk assessment & chemical resistance of chemical protective clothing fabrics will contribute to the upgrade the performances of chemical protective clothing fabrics.

• Fashion & Textile Research Journal
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• v.25 no.4
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• pp.520-533
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• 2023

The present study developed a test protocol for evaluating the mobility of firefighting chemical and flame personal protective equipment (PPE) for the National 119 Rescue Headquarters in Korea and suggested ergonomic design factors to improve their mobility and performance. Six types of PPE were employed, including three types for flame protective PPE (5 ~ 6 kg excluding the self-contained breathing apparatus), and three types for chemical and flame protective PPE (8 ~ 11 kg). These PPEs are used by the 119 Rescue firefighters. Three male firefighters (34.3 ± 1.2 y in age, 175 ± 8 cm in height, 81 ± 13 kg in body weight) participated in the mobility test and interview. A mobility test protocol consisting of 16 components (nine postures and seven motions including a dexterity test) along with a visibility test were developed based on pre-interviews and literature reviews. The findings indicated that the clothing microclimate humidity on the neck and chest exceeded 85%RH on average for all the six PPE conditions, with the chest area reaching as high as 98%RH. This high humidity caused fogging inside the visor and impaired visibility. The requirements for improving the PPE design in terms of mobility varied depending on whether it was the separated types or all-in-one types, particularly regarding the hood and gloves design. The findings of this study can be applied to improve the design of Level A_PPE for firefighters. The mobility test protocol and visibility test developed in this study can also be applied to other types of Level A impermeable PPE.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.4
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• pp.79-84
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• 2010

In recent years, conventional streetlight is replaced by LED streetlight to reduce power consumption dramatically and to maximize lighting effects. However the characteristic of power LED itself driven by high current to increase the illumination, we need to develop effective heat release device. This study suggests new concept of heat dissipation device using PCM (Phase Change Material) and shows an experiment results to investigate thermal effects of PCM.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.398-400
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• 2013

현재 국내 등명기는 대부분 국내 관련업체의 연구개발에 의하여 국산화하고 있으나 대부분 소형 등명기에 소출력 LED Type을 적용하는 수준이다. 최근 고출력 LED 광원은 급격한 광효율 향상(150lm/W)과 가격경쟁력 확보를 통하여 기존 광원 대체를 가속화 하고 있는 상황에서 국내 등명기 관련업체의 LED 등명기 기술개발 수준은 해양 선진국에 크게 미치지 못하고 있는 실정이다. 특히 국내의 20해리(M)이상 광달거리를 요구하는 중 대형 등명기에 LED 광원을 적용하기 위한 LED 광원설계기술, 광학설계, 방열설계 및 항로표지용 등기구 설계 기술 개발 수준은 국제 규격을 만족하기에 매우 미흡한 상황이다. 이에 해양선진국의 LED 광원을 적용하는 중 대형등명기 개발현황 및 동향을 분석하였다.

• Fire Science and Engineering
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• v.5 no.3
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• pp.5-14
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• 1991

Now a days, according that the occurrence of industrial disaster is on the increase, the necessity of protective goods is increasing. Specially estimate of safety helmet for protect of head is very important. On this, in this paper, amplification ratio and natural frequencies of fire safety helmet and general safety helmet are estimated by falling impect test and frequency analysis. Also. trend of damping is estimated by using these test results. And we know that the fire safety helmet is more safe than general safety helmet for protect of head.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.10
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• pp.841-850
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• 2015

With the rapid progress of electronics and radio communication technology, human enjoys greater freedom in information communication. However, EMW(Electro-Magnetic Wave) environments have become more complicate and difficult to control. Thus, international organizations, such as the American National Standard Institution(ANSI), Federal Communications Commission(FCC), the Comite Internationale Special des Perturbations Radio Electrique(CISPR), etc, have provided standard for controlling the EM wave environments and for the countermeasure of the electromagnetic compatibility(EMC). In this paper, fabrication of the smart EMW absorber which has heat radiating function and high performance absorption abilities were suggested. Furthermore, we prospected future smart EMW absorbers. The designed smart EMW absorber is fabricated following process. Firstly, we applied high temperature heat treated to a mixture of Iron-oxide($Fe_2O_3$) and ceramics. Secondly, we applied low temperature heat treated to the mixture of heat treated material and a carbon material. Lastly, we made apertures on the absorber. The designed smart EM wave absorber has the absorption ability of more than 20 dB from 2 GHz to 2.45 GHz band, respectively. Thus, it is respected that these results can be applied as various EMC devices in electronic, communication, and controlling systems.

• Transactions of the Society of Information Storage Systems
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• v.2 no.1
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• pp.21-25
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• 2006

The new multimedia information environment requires smaller optical data storage systems. However, one of the difficulties encountered in designing small form factor(SFF) optical pick-up is to emit the heat which is generated from laser diode(LD). Heat generated at the LD can reduce the optical performance of the system and the lifetime of LD. Therefore, it is important to include the thermal design in the design stage of SFF optical pick-up system for high performance and the longer lifetime of LD, and furthermore, to analyze the thermal characteristics of LD in detail micro heat transfer analysis is necessary. In the present study, micro heat transfer analysis was performed using the finite element method for the $28{\times}11{\times}2mm^3$ super slim swing-arm type optical pick-up actuator for Blu-ray disk. Two different materials were used for a swing-arm; a double layer polycarbonate/steel structure and a single aluminum structure.