• Annual Conference of KIPS
• /
• 2017.04a
• /
• pp.97-100
• /
• 2017

As part of overseas defense program of the US's Trump administration, the military allies were asked to cover partial operation costs for the weaponry deployed at the US bases in their countries. This raised the Korean government's, as well as defense industry's interest in constructing a tactical/strategic communication network and investments are being made actively. Thus, in this study, the performances of WiMAX and WLAN have been compared and a tactical/strategic communication network has been constructed for simulation by using OPNET. As a result, the simulation for the network using combat tanks was successful. An average communication distance that can be achieved by WLAN in open terrain is about 200m as it has been designed on the premise of short-range wireless communications. When the distance was increased to 1km, the tanks could not receive data. By contrast, it was able to confirm that the WiMAX-based network has allowed smooth communications at the same distance. Based on this result, it can be concluded that using WiMAX for tactical operations will have much more merit than adopting WLAN as far as the distance is concerned.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.46 no.10
• /
• pp.814-822
• /
• 2018

This paper proposes a guidance law for missiles with control time constraint. Because the proposed guidance law is based on a time-to-go polynomial, it has a generalized form. Also, acceleration of the proposed law converges to zero at the end of the control time, which reduces the sensitivity to the time-to-go estimation error and can increase the flight stability when the separation of the missile appears. A prediction method of the time-to-go is proposed for implementing the proposed law, and the possibility of application to the midcourse and terminal guidance phases is dealt with for exoatmospheric interception. The characteristics and performance of the proposed law are analyzed throughout various simulations.

• IE interfaces
• /
• v.23 no.2
• /
• pp.147-155
• /
• 2010

Reliability allocation is defined as a problem of determination of the reliability for subsystems and components to achieve target system reliability. The determination of both optimal component reliability and the number of component redundancy allowing mixed components to maximize the system reliability under resource constraints is called reliability-redundancy allocation problem(RAP). The main objective of this study is to suggest a mathematical programming model and a hybrid parallel genetic algorithm(HPGA) for reliability-redundancy allocation problem that decides both optimal component reliability and the number of component redundancy to maximize the system reliability under cost and weight constraints. The global optimal solutions of each example are obtained by using CPLEX 11.1. The component structure, reliability, cost, and weight were computed by using HPGA and compared the results of existing metaheuristic such as Genetic Algoritm(GA), Tabu Search(TS), Ant Colony Optimization(ACO), Immune Algorithm(IA) and also evaluated performance of HPGA. The result of suggested algorithm gives the same or better solutions when compared with existing algorithms, because the suggested algorithm could paratactically evolved by operating several sub-populations and improve solution through swap, 2-opt, and interchange processes. In order to calculate the improvement of reliability for existing studies and suggested algorithm, a maximum possible improvement(MPI) was applied in this study.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.45 no.8
• /
• pp.678-685
• /
• 2017

The radiator of the data storage and handling units onboard the earth observation satellite is a groove-type radiator covered with a shield because of the periodic high heat dissipation and design characteristics of arrangement and mountability of the unit. The effect of the groove-type radiator and that of the shield versus plane radiator were verified through the thermal vacuum test. Through the test result, the temperatures of the radiator and the heat exchange due to the view factor were analyzed by using the analytical method. Conclusively the thermal performance of the shield dissipation plate was verified.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.21 no.4
• /
• pp.429-436
• /
• 2018

The RCS value of maritime ship is indicator of ship's stealth performance and it should be particularly measured for navy ship to ensure survivability on the battlefield. In the design phase of the navy ship, a RCS prediction should be performed to reduce RCS value and achieve ROC(Required Operational Capability) of the ship through configuration control. In operational phase, the RCS value of the ship should be measured for verifying the designed value and obtaining tactical data to take action against enemy missile. During the measurement of RCS for the ship, ship motion can be affected by roll and pitch in accordance with sea state, which should be analyzed into threat elevation from view point of enemy missile. In this paper, we propose a method to measure and analyze RCS of ship in 3-dimensions using a ship motion measuring instrument and a fixed RCS measurement system. In order to verify the proposed method, we conducted a marine experiment using a test ship in sea environment and compared the measurement data with RCS prediction value which is carried by prediction SW($CornerStone^{TM}$) using CAD model of the ship.

• Journal of Advanced Navigation Technology
• /
• v.2 no.2
• /
• pp.84-99
• /
• 1998

As a part of closed-loop guidance law studies for anti-ballistic missile defense, a mid-course guidance law is proposed to engage the target with the predetermined attitude for increased terminal effectiveness. The proposed guidance law is based on the predicted target position calculated from a simplified solution of target motion and the estimates of an extended Kalman filter utilizing noisy nonlinear radar measurements. Extension of the proposed mid-course guidance to 3 dimensional engagements are also studied. Performance of the proposed mid-course guidance law together with a terminal guidance law in the form of conventional proportional navigation guidance is evaluated by a series of simulation studies.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.19 no.5
• /
• pp.98-103
• /
• 2015

A flow passage opening device utilizing an acceleration follow-up technique allows fuel to flow continuously through a pressurized fuel tank system. It is very difficult to test the device in a real flight situation because of severe test condition and a cost problem. In this paper, therefore, the results of a basic negative g test conducted by low-speed airplane are compared with RecurDyn simulation. Dynamic behavior of the device in total flight profile of a high-speed vehicle is also analyzed by using RecurDyn to predict its performance.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.20 no.5
• /
• pp.84-89
• /
• 2016

THPP(Titanium Hydride Potassium Perchlorate) is an igniter composed of potassium perchlorate as oxidizing agent and titanium hydride as fuel with a Viton binder. THPP is commonly found in the aerospace, defence and automotive industries. This research is investigeted for the manufacturing process and characteristics analysis of the THPP such as the performance and shape/calorimetry/pressure characteristics of the THPP on PMD(Pyrotechnic Mechanical Device). Also, THPP composite ratio is designed by CEA program.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.15 no.3
• /
• pp.389-396
• /
• 2020

In order to obtain a good quality product, a proper verification of production/test facilities must be preceded before the quality conformity inspection of the product. Among the various production/test facilities, ATE is widely used in the civilian industry such as the automotive industry, aerospace industry, semiconductor industry today. In addition, ATE is actively used in the defense industry production and performance tests. This paper is the result of systematically verifying the Design Conformance of ATS which is ATE of military FM radio set using various methods. And It is expected to be a good reference at the present time when the design conformity verification procedure for ATE for military supplies is not documented.

• Journal of Positioning, Navigation, and Timing
• /
• v.5 no.3
• /
• pp.157-163
• /
• 2016

Clocks for time synchronization using radio signals such as global navigation satellite system (GNSS) may lose reference signals by intentional or unintentional jamming. This is called as holdover. When holdover occurs, a clock goes into free run in which synchronization performance is degraded considerably. In order to maintain the required precise time synchronization during holdover, accurate estimation on main parameters such as frequency offset and frequency drift is needed. It is necessary to implement an optimum filter through various simulation tests by creating clock noise in accordance with given specifications in order to estimate the main parameters accurately. In this paper, a method that creates clock noise in accordance with given specifications is described.