• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.7
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• pp.738-746
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• 2016

As the trend of future war has been changed to network centric warfare, tactical data link should be needed for fast and accurate situation awareness. Nowadays, Korean air force conducts military operations by using aircrafts equipped with Link-16. The Link-16 can conduct multiple mission at the same time because it supports multi-net capability. Due to lack of frequency resource, the way to share the frequency with other systems has been studied and using L band with radar is considered as one of the candidates bands. However, the data link can be affected by the interference from radars when it shares the L-band because the L-band in Korea is already assigned to long-range detection radars. In this paper, we evaluate operational possibilities of tactical data link in the L-band based on Link-16.

• Convergence Security Journal
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• v.17 no.5
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• pp.153-161
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• 2017

The gain a decision by a prediction supposition future combat. Take a future combat by the method fighting of U.S. Army in the Irak war. A make combat progress is from real time information to precision bombing for a guided weapon by GPS, a intelligence satellite, a pilotless scout plane, real time simultaneous and unification combat power are the kernel element of gain a decision fighting power by network in the ground, sky, marine, universe, cyberspace. The NCW is in a sense network center war organic be connected by networking a factor of operation. Any where networking information collection, command and decision, blow system. The Study on the improvement plan for Military combat power by base of NCW abainst the future War. Construct an integrate intelligence network apply to future combat.

• Journal of the Korea Institute of Military Science and Technology
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• v.26 no.1
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• pp.54-63
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• 2023

In this paper, a VHF band conformal antenna for UAV mounting was developed. The proposed antenna was designed as an shape-adaptive structure by minimizing the antenna height to be advantageous in RCS reduction performance. As for the antenna radiator, the outer radiator was arranged around the inner radiator to apply the CRLH zeroth-order resonance structure. With this structure, the height of the antenna was minimized, and it was reduced by about 70 % compared to the existing blade antenna. In addition, for impedance matching, the intermediate frequency bandwidth of the VHF band was improved through the sleeve pin of the inner radiator, and the low frequency bandwidth of the VHF band was improved by applying an EMI shielding gasket to the shorting pin of the outer radiator. The proposed antenna was manufactured and measured to verify the performance of the device and the performance after UAV mounting. As a result, the standard was satisfied for the operating frequency.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.3
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• pp.245-255
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• 2023

Time comparison techniques are necessary for generating and keeping Coordinated Universal Time (UTC) and distributing standard time clocks. Global Navigation Satellite System (GNSS) Common View, GNSS All-in-View, Two-Way Satellite Time and Frequency Transfer (TWSTFT), Very Long Baseline Interferometry (VLBI), optical fiber, and Network Time Protocol (NTP) based methods have been used for time comparison. In these methods, GNSS based time comparison techniques are widely used for time synchronization in critical national infrastructures and in common areas of application such as finance, military, and wireless communication. However, GNSS-based time comparison techniques are vulnerable to jamming or interference environments and it is difficult to respond to GNSS signal disconnection according to the international situation. In response, in this paper, Code-Division Multiple Access (CDMA) based All-to-All TWSTFT operation method is proposed. A software-based simulation platform also was designed for performance analysis in multi-TWSTFT signal environments. Furthermore, code and carrier measurement jitters were calculated in multi-signal environments using the designed simulation platform. By using the technique proposed in this paper, it is anticipated that the TWSTFT-based time comparison method will be used in various fields and satisfy high-performance requirements such as those of a GNSS master station and power plant network reference station.

• Journal of the Korea Society of Computer and Information
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• v.26 no.9
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• pp.105-114
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• 2021

ESICD(Electrical Signal Interface Control Document) refers to a document that describes protocols and data for communication between components consist of a system. Each component developer gathers at a specific place to conduct an integrated test for ESICD verification. In this case, it often happens that the integration test is delayed due to a simple mistake of software developers. There are two reasons for this situation: First, software developers do not perform sufficient verification because it is difficult to configure the system environment in a Lab, and second, they do not immediately find the cause of errors occurred during integration tests. Therefore, in this paper, we propose a strategy to effectively perform ESICD verification, which takes a lot of time between the production and implementation stage of the weapon system development stage and the system integration test stage.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.4
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• pp.22-31
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• 2010

In this paper, a new split ring resonator using left-handed meta-material adapted in a bandpass filter with 2-stages is suggested. In this proposed bandpass filter, the size of the novel resonator can be easily controlled. Also, the bandwidth can be adjusted with the position of the tapped-line. The proposed resonator and filter has the center frequency of 10 GHz for I-band in military-satellite communication system with the Qe value of 184. The experimental results of the filter show that the insertion and return losses are 1.43 dB and 16.8 dB with bandwidth of 10 %, respectively.

• Journal of Positioning, Navigation, and Timing
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• v.4 no.1
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• pp.9-16
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• 2015

The applications of Global Navigation Satellite System (GNSS) receivers are becoming wider in various commercial and military systems including even small weapon systems such as artillery shells. The precision-guided munitions such as Small Diameter Bomb (SDB) of United States can be used for pinpoint strike by acquiring and tracking GNSS signals in high mobility situation. In this paper, a small GNSS receiver with embedded interference suppression capability working under high dynamic stress is developed which is applicable to the various weapon systems and can be used in other several harsh environments. It applies a kind of matched filter and multiple correlator schemes for fast signal acquisition and tracking of even weak signals and frequency domain signal processing method to eliminate the narrowband interference. To evaluate the performance of the developed GNSS receiver, the test scenario of high mobility and interference environment with the GNSS simulator and signal generator is devised. Then, the signal acquisition time, navigation accuracy, sensitivity, and interference suppression performances under high dynamic operation are evaluated. And the comparison test with the commercial GNSS receiver which has high sensitivity is made under the same test condition.

• Journal of computational fluids engineering
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• v.18 no.1
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• pp.13-21
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• 2013

Cavitating flow is usually formed on the surface of a high speed underwater object. When a object moves near a free surface at very high speed, the cavity signature becomes one of the major factors to be overcome by sensors of military satellite. The present work was to study the free surface effect on the ventilated cavitation. The governing equations were Navier-Stokes equations based on a homogeneous mixture model. The multiphase flow solver used an implicit preconditioning method in the curvilinear coordinate system. The cavitation model used here was the one first presented by Merkle et al.(2006) and redeveloped by Park & Ha(2009). Computations considered the free surface effects were carried out with a NACA0012 hydrofoil and the corresponding results were compared with the experimental data to have a good agreement. Calculations were then performed considering the ventilated cavitation, including the effect of non-condensable gas under the free surface effects.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.573-575
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• 2015

Positioning system using satellite GPS is used at positioning, navigation, acquisition time information and other various field and taking an important part precision guided weapon such as missile. But commercial code(C/A code) do not have ECCM. Therefore commercial code is vulnerable to various jamming techniques and noise jamming from near station can attack even the encrypted military code(P code) GPS. In this paper, GPS jamming techniques, North Korean GPS jamming cases and anti-jamming GP S technologies are surveyed and described.