• Journal of the Semiconductor & Display Technology
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• v.20 no.4
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• pp.62-67
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• 2021

In this study, we have successfully developed an unique NVIS Green A compatible LED by combining two technologies. One is white LED made with a black EMC (epoxy molding compound) lead frame. The other is NVIS Green A filter that shields the near infrared region made in the film method. The form factor of the developed NVIS Green A compatible LED was 2.0 × 2.0 × 0.95 mm. And it is possible to satisfy NVIS radiance and color limit specified in MIL-STD-3009 by controlling the concentration of Green A dye and the thickness of the NVIS filter as well as adjusting of color temperature of the white LED. From these results, we are expected that the developed NVIS Green A suitable LED is a promising solution for the weight reduction and the cost reduction of avionic applications.

• Journal of the Korea Institute of Military Science and Technology
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• v.26 no.2
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• pp.171-178
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• 2023

PCM data is result of air-vehicle flight test, this data is distributed for each engineers to analyze its condition. Since line-of-sight between the air-vehicle and the ground receiver cannot always be secured, remote PCM data recording system was claimed to be required. In this paper multi-function PCM data recorder has been described. This PCM data recorder was intended to place on inside of flight object. It can record about two hours in 32 GB SD card with maximum 7 Mbps data rate. RS-422/485 and RJ-45 interface enhanced accessibility for users. 5 V and 1 A power consumption and 19.5 mm × 152.5 mm × 102.3 mm allow to connect with mobile PCM devices. It acquired more than 190-minutes data in 12-times flight test. Also, it achieved military standard environmental test MIL-STD-810G to prove its stability and solidness.

• Transactions of the Korean hydrogen and new energy society
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• v.35 no.1
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• pp.83-89
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• 2024

In order to confirm the safety against vibration of high-pressure fittings for mobile hydrogen charging devices, the natural frequency was confirmed through ANSYS, and vibration data occurring during driving was applied to utilize the vehicle's operating power spectral density data specified in MIL-STD-810H regulations. Fatigue analysis and resonance were confirmed, and as a result, it was confirmed that the sum of the pure phase ratios was less than 1 for the driving history presented in the standard, and there was no risk of resonance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4418-4425
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• 2012

The demand on applying the performance-based logistics (PBL) in the operational phase of the weapon systems development is increasing these days. Therefore, the enhancement of the PBL concept and process needs to be done. This is the objective of the paper. As a method of approach, a modeling method is adopted to cover the whole life cycle of the weapon systems development from the concept development to the operation. The modeling results for the PBL process yield an useful suggestion for improvement. Also, by analyzing the interrelationship model between the PBL process and the integrated logistics support (ILS) procedure, it is possible to take advantage of the PBL concept in the ILS elements development, which is usually carried out from the beginning of the development phase, a lot earlier than the operational phase. Note that the PBL concept has been restrictively applied in only the supply support among many ILS elements up until now. However, the results obtained in the paper can make it also possible to consider the availability, reliability, logistics support, cost and so on from the early phase of the weapon systems development.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.1
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• pp.1-11
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• 2017

In this paper, design requirements of the large radar were investigated, and development was performed through the analysis and design. Large radar should be designed by bearing the 75 knot wind force and $20kg/m^2$ ice mass as operating conditions in order to meet structural stability, and driving torque and bearing load were calculated for securing the driving stability. Thermal dissipation analysis was performed considering TRM and DC-DC Converter's limitation temperature by $50^{\circ}C$ ambient temperature condition in order to attain thermal stability, and PSD and shock analysis were carried out by using MIL-STD-810G vibration and shock specification in order to transport and installation of the large radar. As a result, all components of large radar could secure the structural stability more than 2.8 factor of safety, and driving stability was also secured with adequate bearing fatigue life. Thermal stability was attained by allowable max temperature 88.7 C of the TRM, and structural stability for transportation and installation of the large radar was also secured more than 5 factor of safety. After it was transported and installed to the radar site, operating capability was finally verified by rotating the large radar.

• Journal of Satellite, Information and Communications
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• v.11 no.3
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• pp.65-71
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• 2016

Currently developing the OBC of the next-generation LEO satellite by Korea Aerospace Research Institute adopts the LEON2-FT/AT697F processor to achieve high performance. And various communication devices such as SpaceWire, MIL-STD-1553B, DMAUART and CAN Master are integrated to the separated standard communication FPGAs within the OBC, where they can be controlled by the processor and flight software (FSW) through PCI interface. The Actel 1553BRM IP core is used for the 1553B in the next-generation LEO OBC and the B1553BRM wrapper from Aeroflex Gaisler is used for connecting it to the AMBA bus in FPGA. This paper presents the design and development of PCI-based 1553B communication software, and describes the handling mechanism of 1553B operation in FSW task level. Also it shows the test results on real-hardware and simulator.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.2
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• pp.29-36
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• 2008

In this paper, mechanical reliability issues of copper through-wafer interconnections are investigated numerically and experimentally. A hermetic wafer level packaging for MEMS devices is developed. Au-Sn eutectic bonding technology is used to achieve hermetic sealing, and the vertical through-hole via filled with electroplated copper for the electrical connection is also used. The MEMS package has the size of $1mm{\times}1mm{\times}700{\mu}m$. The robustness of the package is confirmed by several reliability tests. Several factors which could induce via hole cracking failure are investigated such as thermal expansion mismatch, via etch profile, and copper diffusion phenomenon. Alternative electroplating process is suggested for preventing Cu diffusion and increasing the adhesion performance of the electroplating process. After implementing several improvements, reliability tests were performed, and via hole cracking as well as significant changes in the shear strength were not observed. Helium leak testing indicated that the leak rate of the package meets the requirements of MIL-STD-883F specification.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.7
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• pp.712-718
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• 2008

This paper deals with a development of flight control law switching system which can be used for flight test of the research control law by switching control law during flight. Through this research program, fader logic and integrator stabilization design has been introduced to minimize the transient response of aircraft caused by flight control law switching and to prevent the divergence of the integrator included in the control law in standby mode. MIL-STD-1553B communication was applied to transfer the data between the two control laws. This paper introduce the control law switching system architecture and major design concept and include the system verification and validation result performed on the flying quality simulator of the advanced trainer.

• Journal of the Korea Institute of Building Construction
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• v.13 no.1
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• pp.84-89
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• 2013

This study aims to examine the effectiveness of electromagnetic pulse shielding in cast-in-place protective shelters using corrugated metal-plates, and then reviews their usability for the Republic of Korea Army. The Korea Corps of Engineering has evaluated corrugated metal-plates as a construction material for cast-in-place structures, which have to defend against mechanical impacts as well as electromagnetic pulses. Corrugated metal-plate is known as a superb mechanical protective material, so much so that it has been employed in ammunition magazines and artillery platforms in the armed forces. Moreover, as a metal, such as steel and copper, it is universally recognized as one of the most effective electromagnetic pulse shielding materials. In addition to effectively shielding from electromagnetic pulses and protecting against mechanical impacts, corrugated metal-plates should prove to be an appropriate construction material for the cast-in-place protective shelter in terms of construction availability and economic feasibility. The shielding effectiveness of the suggested structures is examined based on MIL-STD 188-125-1. A few frequency bands need an increase of 15~30dB in shielding effectiveness because of unbidden apertures caused by flaws associated with welding, assembling, and material deformation. However, allowing for the approximately 40dB of shielding provided by soil; the examined structure, which is buried underground, can offset its shortcomings sufficiently.

• Aerospace Engineering and Technology
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• v.5 no.2
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• pp.143-148
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• 2006

This article summarizes the results of sea transportation load measurements, which will be used as the reference to the sea transportation environment condition for the launch vehicle of KSLV-I. KSLV-I will be transported by Sea from Pusan to the NARO space center in Gohung, Chunnam province. Since the vibration load condition during sea transportation is considered as one of the important design parameters of KSLV-I and its transportation means, it is necessary to directly measure the environmental condition of sea transportation loads prior to establish the sea transportation plan in detail. This material includes the measured data of 3-axis linear accelerations and 3-axis angular rates on the board of a barge-ship, which is towed by a tug boat during shipping operation. This barge-ship is same class with one which will actually carry KSLV-I. The results show that the measured load condition during sea transportation is not severer than the reference data of MIL-STD-810F and Zenit-3SL launch system.