• Aerospace Engineering and Technology
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• v.6 no.2
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• pp.111-118
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• 2007

KSLV-I which is being developed in KARI is composed with two stages, and adaptor ring is used for coupling stage. Cables for interconnecting between stage is exposed on the outside. Also 8 pyro bolts which are installed in adaptor ring are used for separation of stage. In general, cowl is used for protecting exposed parts or structure which are anxious about damage from outer environment. In KSLV-I, two kind of cowls are designed. The one is umbilical cowl, and the other is pyro bolt cowl. Because cowl is exposed on the outside, heat and pressure load developed from air have effect on cowls. Therefore verification of structural strength through static analysis is required. In this study, static analysis in load condition except heat load is accomplished. In result of analysis, structural strength of pyro bolt cowl is verified. But breakage of umbilical cowl is confirmed in pressure load condition. So design of umbilical cowl is modified for satisfying required structural strength. And structural strength of umbilical cowl through analysis is verified.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.5
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• pp.503-510
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• 2021

This paper presents a system that measures the acceleration of the shock caused by the explosion of the precursor warhead for the tandem projectile. The proposed system, which is implemented based on the MIL-STD-810G, Method 517.1, consists of a miniaturized shock measurement device, a cable, accelerometers, and a trigger circuit. The shock measurement device has a size of ¢102 × 171 mm and cable has a length of 3 m. The operational confirmation test is conducted by implementing the measurement system. The Analysis of shock data(accelerometer output data) is carried out using Shock Response Spectrum(SRS), pseudo velocity and plot of acceleration time transient. Through measurement analysis, one can predict the damage of electronics in projectile when precursor warhead is exploded.

• Proceedings of the Korean Society of Laser Processing Conference
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• 2002.11a
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• pp.109-113
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• 2002

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.1209-1210
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• 2017

착용자의 정보를 실시간으로 전송하여 사고 예방 및 빠른 대처가 가능한 스마트 안전모를 개발한다. 안전모 내부에는 라즈베리파이와 아두이노, 보조배터리, 각종 센서 모듈들이 내장되어 있다. 라즈베리파이는 카메라 모듈과 통신 모듈을 갖고 있다. 아두이노에는 소리센서와 도어락센서, 충격센서가 장착되어 있다. 카메라 모듈을 통해 작업자의 주변 상황에 대해 실시간으로 촬영하고 관리자 서버로 전송한다. 또한 각 센서들은 여러 정보를 수집하고 관리자 서버로 전송한다. 관리자 서버는 수집된 정보를 이용하여 작업자의 상황을 파악하고 분석하여 위험 상황에 대해 적절한 대처를 수행한다. 이러한 여러 기능을 통해 스마트 안전모는 무선통신 환경에서 상황에 따른 센서들의 동작에 의해 착용자의 안전을 도모할 수 있다.

• Korean Journal of Construction Engineering and Management
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• v.5 no.6 s.22
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• pp.218-225
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• 2004

The supply for the apartment complex in Korea has been accomplished by the sale before building system as a way of institutional means to support massive housing supply in the past. Although this sale before building system has helped the provision of the housing, the necessity of that has been weakened in the current housing market. As this market is changed to emphasize on consumer, the necessity of conversion to sale after building system was raised and finally enforced partially. However, the sale after building system has difficulty in ensuring construction fund and the safety of housing business. So, the diversification in the style of business structure we and the strategy for the activation of construction fund will solve these problems. Consequently, this essay examine the change and influence in the construction fund after adopting sale after building system and suggest the appropriate strategy in project financing for providing fund and reducing the risk in construction business.

• Laser Solutions
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• v.6 no.1
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• pp.17-24
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• 2003

The purpose of this study is to evaluate thermal shock resistance and thermal shock fracture toughness for ATJ graphite. Thermal shock resistance and thermal shock fracture toughness of ATJ graphite are evaluated by using CO$_2$ laser irradiation technique. The laser heat source is irradiated at the center of specimens. Temperature distribution on the specimen surface is measured using the thermocouples of type K and C. SEM and radiographic images are used to observe the cracks which are formed at the thermal shock specimens.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.01a
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• pp.125-126
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• 2020

본 프로젝트는 고객과 택배기사가 배송과정에서 겪는 불편함을 해소하기 위해 App과 IoT센서를 연동하여 배송과정의 편의성을 제공하는 무인 택배함이다. 기존 택배함의 비밀번호를 사용하는 방식이 아닌 택배함에 부착되어있는 NFC 태그 스캔을 통하여 편리하게 물품을 배송 및 보관할 수 있도록 하였다. App은 택배기사와 고객으로 나뉘어 있으며 택배기사 App의 주요 기능은 운송장 번호를 스캔하여 물품을 보관할 여러 택배함 중 하나를 선택하여 해당 택배함의 도어락을 제어하는 기능이 있으며, 고객 App의 주요 기능은 NFC 스캔을 통해 물품이 보관된 택배함 또는 보관할 택배함을 선택하여 도어락을 제어하는 기능이 있다. 그 외에 택배기사 App은 배송 목록 조회, 내 정보 확인 등의 서비스를 제공하고 있으며, 고객 App은 택배 예약, 예약 조회 등의 서비스를 제공하고 있다. 택배함은 와이파이 모듈을 통해 서버와 통신할 수 있도록 하였으며, 충격센서와 Mp3 모듈을 사용하여 택배함에 충격을 가하면 경보음이 울리도록 설계하였다.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.591-597
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• 2003

The demand of LNG in Korea has dramatically increased since it was first imported in 1986. Thus, more LNG storage tanks are required to meet the growing consumption of LNG. However the design, construction, and analysis of LNG storage facility need highly advanced technology compared to the general structures due to the fluid-structure interaction and the low temperature of LNG. Recently Korea Gas Corporation(KOGAS) constructed a pilot LNG storage tank, and it is in operation to develop and accumulate the core technology. As a part of those objects, the fundamental dynamic test for the pilot tank were performed. For this study, dynamic test were carried out and the dynamic characteristics of the pilot tank were verified and analyzed.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.2
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• pp.162-168
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• 2011

Launch vehicles and satellites experience severe vibration and pyroshock during the flight phase. These severe dynamic loading could result in the malfunction of electric devices which equipped in the launch vehicle and satellite. In this paper, mesh washer isolators are applied to attenuate these severe shock and vibration and isolation performances are enhanced by applying pseudoelasitic SMA wire material. Through random vibration and ground pyroshock tests, outstanding isolation performances are studied. Especially, comparison of isolation performances due to the change of pre-compressive displacement of mesh washer itself are suggested and applicablity to the adaptive vibration control are confirmed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.243-246
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• 2006

Most of the guided weapons have been kept and transferred at the launching tube and fired in case of necessity in these day. Launching tube is a kind of case to protect the guided weapons from external environments and conducted as a guide when they are fired. When we attached the guided weapons to launching tube we usually has used explosive bolt. Explosive bolts have been used explosives when they had to be separated. But when they are separated there are some bad effects; a flame, fragments and pyre-shock. Because of these bad effects there are many restriction to use bolt as joining devices to precision guided weapons. To solve these problems we invented ball type bolt. Unlike explosive bolt, ball type bolt is separated without a flame, fragments and pyre-shock. And it also has a good mechanical properties as much as those of explosive bolt.