• Electronics and Telecommunications Trends
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• v.36 no.5
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• pp.74-81
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• 2021

Based on data provided by the science and technology knowledge infrastructure (ScienceON, 2017-2021), this paper reviews the research trends of domestic police services and related technologies, and describes the research and development direction of policing technology. For this purpose, the research was searched using the keywords science policing, smart policing, predictive policing, and policing. Policing technology is used for crime investigation (prevention), such as crime analysis and crime prediction. The collection of related data use urban infrastructure, the processing of data collected using technologies, such as artificial intelligence, and the utilization of data in police services (system) were summarized. In future, on-site support technology and crime investigation (prevention) technology for a preemptive correspondence to social threats and effective police activities must be developed. In addition, the quality of police services should be improved, a system to use police-related data should be developed, and the capabilities of police experts need to be strengthened.

• Particle and aerosol research
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• v.15 no.2
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• pp.57-65
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• 2019

Recently, there has been much research on the effect of fine dust on human body with increasing interest in the fine dust. Thermal power plant, which is considered as one of the main sources of fine dust, is reported to be responsible for 14% of the total amount of domestic fine dust in the Republic of Korea. Therefore, dust collecting devices in the thermal power plant need to be improved. In this study, the electrostatic precipitator (ESP) was considered to substitute for a mist eliminator used in flue gas desulfurization facility. By considering real situation in the flue gas desulfurization facility, the collection efficiency of the ESP was evaluated by using the sprayed limestone slurry particles. The collection efficiency of the ESP was higher than that of the mist eliminator, showing the possibility of replacing the mist eliminator with the ESP in flue gas desulfurization facility.

• Journal of the Semiconductor & Display Technology
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• v.17 no.3
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• pp.59-64
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• 2018

In recent years, the solar cell market has steadily grown with the demand for new energies. And wire sawing is one of the most critical processes in manufacturing solar cell wafer which is supposed to affect the breakage of wafers most during the process and afterwards. Generally, the defects of the wafers are generated from the structural vibrations of the machine. In the sawing process, the vibrations cause unnecessary normal stress on the cut surface of wafers, and eventually create the surface damage or leave the residual stress. In this study, the dynamic properties of a wire saw have been analyzed through the frequency response test and the computer simulation. And the effects of the design alterations have been investigated to stabilize the machine structure and further to reduce the vibrations. The result shows that relatively simple design alterations of supporting structure without any change of major parts of the machine can suppress the vibrations of the machine effectively.

• Journal of National Security and Military Science
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• s.15
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• pp.117-151
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• 2018

The development of local defense parts has played a role a pure function such as maintenance of stable procurement source of military goods, provision of timely supply, establishment of self-defense base, creation of import substitution effect considering the whole life-cycle cost, reduction of foreign currency and protection of domestic defense industry. However, as the development success rate is deteriorating, it is time to analyze the related policies and improve the system. In order to improve the success rate of development of parts for the defense sector, it is necessary to unify the separated policies by the development-related departments and strengthen the policy support for the development companies to actively participate in the development. In addition, it is necessary to improve the paradigm for the selection of development items and change the authority of selecting development items and to delegate authority to create synergies. Parts localization development policy improvement is military support side it will contribute to strengthening defense power management by organically combining with technological development aspect and economical aspect. Development items will be linked to defense exports, which will have a remarkable effect on sales growth and job creation effects. The development of local defense parts is spreading.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.1
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• pp.84-98
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• 2021

The hydrodynamic characteristics of amphibious assault vehicles are investigated using commercial CFD code, STAR-CCM+. Resistance performances of a displacement-type vehicle and a semi-planing type vehicle are analyzed in calm water. The self-propelled model is also computed for the semi-planing type vehicle. All computations are performed using an overset mesh system and a RANS based flow-solver coupled with a two-degree of freedom equations of motion. A moving reference frame is applied to simulate revolutions of impeller blades for a waterjet propulsion system. Grid dependency tests are performed to evaluate discretization errors for the mesh systems. The numerical analysis results are compared with the experimental results obtained from model tests. It is shown that RANS is capable of investigating the resistance and self-propulsion characteristics of high-speed amphibious assault vehicles. It is also found that a fully covered side skirt, which is covering tracks, reduces resistance and stern trim, besides increasing propulsive efficiency.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.3
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• pp.275-284
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• 2022

Linear Shaped Charge(LSC) is widely used as a separation system in the field of weapon system. However, there are some disadvantages that are charging lots of explosives due to lack of uniformity and having difficulties of the design of liner and explosives because of manufacturing process. In order to solve these problems, Precision Linear Shaped Charge(PLSC) that can design a liner independently and charge explosives uniformly has been developed. In this study, PLSC was designed to have a proper liner shape and amount of explosives, and the penetration test of PLSC with different stand-off distance from liner to target was conducted. On the basis of the penetration test results of PLSC, the numerical analysis method using AUTODYN was established and verified. The penetrative mechanism and characteristics of PLSC with targets of different materials was analyzed from experimental and numerical results.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.2
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• pp.135-143
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• 2022

In this paper, the compact waveguide slot array antenna for interferometric radar altimeter is proposed. The proposed antenna structure consist of corrugation structure which is applied between each channel to improve isolation, three-channel waveguide slot array antenna and feeder. In addition, to reduce the occurrence of phase ambiguity, the baseline spacing of the three-channel antenna is analyzed and the results are applied to the design. For compact design, reduced height and SMP connector structure are used and the dip brazing method which is the conjugation method after dipping to flux is used for the fabrication of the lightweight antenna. The measurement result of the proposed antenna shows less than 1.41 : 1 (VSWR) and 48.3 dBc (isolation). The antenna gain is higher than 20.2 dBi and the side lobe levels are lower than 18.8 dB (vertical plane) and 10.0 dB (horizontal plane).

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.2
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• pp.1-11
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• 2022

In this paper, we investigate the requirements of QPA(Quality Process Audit), which is a process quality audit system for secondary defense contractors, compared with those of DQMS(Defense Quality Management System). And evaluate whether the deployment of QPA meets the DQMS certification requirements through the case example of Company H. The evaluation items of QPA are composed of five categories such as Material Management, Incoming Inspection, Manufacturing Process, Product Evaluation, and Packaging Management. The QPA requirements are mainly related to the chapter 7(support) and chapter 8(operation) of DQMS standards. In this view point, QPA can be expected as an effective audit for suppliers preparing for DQMS certification. In the case example, we evaluate the results and effects of improvement due to QPA and compare it with the case of DQMS. QPA can be used as appropriate quality management standards of secondary and tertiary defense contractors and can provide the basis guidelines for the preparation of implementation steps in DQMS certification.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.4
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• pp.401-411
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• 2022

As the role of high-value air assets(e.g., AWACS, JSTARS, Rivet Joint, E-2) becomes more critical in modern warfare, the air escort for these assets blocking attacks from any potential enemy fighter also becomes vital. Without the escort, the operations of the assets become restricted. However, such an escort is not always possible due to the limited flight time of the escort fighters. In this paper, we introduce an escort tactics for high-value air assets performed by the manned-unmanned teaming composed of a transport aircraft and UAVs(unmanned aerial vehicles). In this tactics, the transport aircraft plays the role of an aircraft carrier, which carries, launches, and retrieves the UAVs. The missions of UAVs in this tactics are to detect and engage enemy fighters. We also introduce the simulation result of this tactics to identify the UAVs' required capabilities and optimal maneuvering.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.6
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• pp.619-628
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• 2021

In order to compare numerical analyses made by Song and Kim needed for predicting gas and water filling with experimental results we conducted an experiment to recover a test projectile (43.7 kg with a 155 mm diameter) at a velocity of 775 m/s in a soft recovery system with a length of 179 m using pressurized gas and filled water. The soft recovery system consisting of a series of pressure tubes had a diaphragm, piston, and water plug for filling the pressurized gas and water. We installed a continuous wave Doppler radar system for velocity measurements of the test projectile travelling in the pressure tubes and pressure transducers for measuring the pressure in the soft recovery system. Continuous wave Doppler radar has the advantage of achieving real-time measurements of the velocity of a test projectile. The velocity-time curve of the test projectile, measured using the continuous wave Doppler radar, and the pressure profile were compared with the numerical analysis results. The experiment results show good agreement with the numerical analysis results based on the one-dimensional Euler equation with an HLL Riemann solver.