• The Journal of the Convergence on Culture Technology
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• v.9 no.5
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• pp.397-401
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• 2023

The study presents milestones for the Korean military to win the future battlefield based on the 4th Industrial Revolution. Chapter 1 deals with the necessity of research on how advanced countries operate industrial technology in the defense sector based on the 4th Industrial Revolution. Chapter 2 examines the current technology status of the 4th Industrial Revolution in Korea and the concept of Korean combat. Chapter 3 analyzes the military robotic technology of advanced military countries through examples of unmanned combat robots in the United States, Israel, and Germany. In the end, in future battles, it will be possible to dominate the battlefield only by taking a leap into a super-connected and super-intelligent military based on a high-tech platform. Our military should also research and develop military robotics in accordance with the characteristics of each combat system, and further expand and develop the concept of combat performance to protect our core capabilities and centers from enemy cyber, electronic warfare, and space attacks.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.4
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• pp.359-367
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• 2023

In order to ensure the high-integrity of reference stations of satellite navigation system, cycle slip should be precisely monitored and compensated. In this paper, we proposed a cycle slip algorithm for the integrity monitoring of the reference stations. Unlike the legacy method using the Melbourne-Wübbena (MW) combination and ionosphere combination, the proposed algorithm is based on ionosphere combination only, which uses high precision carrier phase observations without pseudorange observations. Two independent and complementary ionosphere combinations, Ionospheric Negative (IN) and Ionospheric Positive (IP), were adopted to avoid insensitive cycle slip pairs. In addition, a second-order time difference was applied to the IN and IP combinations to minimize the influence of ionospheric and tropospheric delay even under severe atmosphere conditions. Then, the cycle slip was detected by the thresholds determined based on error propagation rules, and the cycle slip was identified through weighted least square method. The performance of the proposed cycle slip algorithm was validated with the 1 Hz dual-frequency carrier phase data collected under the difference levels of ionospheric activities. For this experiment, 15 insensitive cycle slip pairs were intentionally inserted into the raw carrier phase observations, which is difficult to be detected with the traditional cycle slip approach. The results indicate that the proposed approach can successfully detect and compensate all of the inserted cycle slip pairs regardless of ionospheric activity. As a consequence, the proposed cycle slip algorithm is confirmed to be suitable for the reference station where real time high-integrity monitoring is crucial.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.6
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• pp.1087-1094
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• 2023

Due to the development of technologies, such as big data, cloud, IoT, and AI, The high data throughput is required, and the importance of network flexibility and scalability is increasing. However, existing network systems are dependent on vendors and equipment, and thus have limitations in meeting the foregoing needs. Accordingly, SDN technology that can configure a software-centered flexible network is attracting attention. In particular, a load balancing method based on SDN can efficiently process massive traffic and optimize network performance. In the existing load balancing studies in SDN environment have limitation in that unnecessary traffic occurs between servers and controllers or performing load balancing only after the server reaches an overload state. In order to solve this problem, this paper proposes a method that minimizes unnecessary traffic and appropriate load balancing can be performed before the server becomes overloaded through a method of assigning weights to servers in stages according to server load.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.6
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• pp.1095-1102
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• 2023

Content Centric Network (CCN) is a network that emerged to improve the existing network structure and communicates based on content names instead of addresses. It utilises caches to distribute traffic and reduce response time by delivering content from intermediate nodes. In this paper, we propose a popularity-based caching policy to efficiently utilise the limited CS space in CCN environment. The performance of CCNs can vary significantly depending on which content is prioritised to be stored and released. To achieve the most efficient cache replacement, we propose a real-time content popularity-based efficient cache replacement policy that calculates and prioritises content popularity based on constructor popularity, constructor distance, and content hits, and demonstrate the effectiveness of the new policy through experiments.

• Journal of the Korea Society for Simulation
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• v.33 no.2
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• pp.13-25
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• 2024

In the performance analysis of a weapon system, the combat effectiveness is difficult to go beyond the conceptual level in the early stages of development. This is especially true in the case of new concept of weapon system that has never existed before. In this study, with the aim of analyzing the effectiveness of small personal guided weapons, the design of the warhead and the detonation test were carried out and the results were analyzed. Afterwards, trajectory of fragments were calculated from the results, and it is applied to the anti-personnel effectiveness logic which is a part of combat simulation tool. At the same time, delivery accuracy logic was constructed from Monte-Carlo simulation with 6-DOF trajectory model. Subsequent simulated experiments were conducted with test scenarios to confirm the simulation logic reflecting the results of the warhead detonation tests for verifying the simulation approach of weapon systems, and it was confirmed that the simulation logic incorporating the results of the warhead detonation tests functioned properly.

• Journal of the Korea Safety Management & Science
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• v.26 no.3
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• pp.1-9
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• 2024

This study aims to develop a regression model using data from the Ammunition Stockpile Reliability Program (ASRP) to predict the shelf life of 81mm mortar high-explosive shells. Ammunition is a single-use item that is discarded after use, and its quality is managed through sampling inspections. In particular, shelf life is closely related to the performance of the propellant. This research seeks to predict the shelf life of ammunition using a regression model. The experiment was conducted using 107 ASRP data points. The dependent variable was 'Storage Period', while the independent variables were 'Mean Ammunition Velocity,' 'Standard Deviation of Mean Ammunition Velocity,' and 'Stabilizer'. The explanatory power of the regression model was an R-squared value of 0.662. The results indicated that it takes approximately 55 years for the storage grade to change from A to C and about 62 years to change from C to D. The proposed model enhances the reliability of ammunition management, prevents unnecessary disposal, and contributes to the efficient use of defense resources. However, the model's explanatory power is somewhat limited due to the small dataset. Future research is expected to improve the model with additional data collection. Expanding the research to other types of ammunition may further aid in improving the military's ammunition management system.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.34 no.5
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• pp.156-162
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• 2024

Silicon carbide (SiC), known for its excellent mechanical and chemical properties, is widely used in key industries such as aerospace, defense, and nuclear power generation. Due to its rapid heating characteristics when exposed to microwaves, SiC is being researched as a highly efficient heating element. In this study, Polycarbosilane (PCS) was treated by a mechanochemical reaction with iodine, followed by pyrolysis to create a microwave heating material. The effects of pyrolysis temperature and iodine additive content on microwave heating performance were investigated. The results showed that the fabricated specimen rapidly heated to a maximum of 800℃ within approximately 60 sec and maintained a stable temperature of 700~750℃ for up to 120 min.

• Journal of Advanced Navigation Technology
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• v.28 no.5
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• pp.726-731
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• 2024

This paper proposes a charge-discharge control circuit using capacitors and verifies the performance of the circuit for charge, emission, and discharge operations. The proposed control circuit performs multiple emission operations without inter-circuit influence because it uses capacitors independently for each emission circuit. Even with the instability of the input power, the output energy during emission stably supplies more than 1.6 mV of energy, which is the energy required for output, through the charging function of the capacitor. After release, the remaining energy of the capacitor is safely discharged by more than 99% of the 3.125 V remaining in the capacitor through the discharge function of the capacitor, confirming that approximately 25 mV remained. The proposed control circuit confirmed the stability and reliability of the emission device through simulation and measurement results.

• Journal of Advanced Navigation Technology
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• v.28 no.5
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• pp.610-615
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• 2024

Based on the K-UAM roadmap, this study evaluated the safety for the initial UAM demonstration project and operation. Research in each field is underway for early settlement of UAM, but the progress of research is showing limitations without clear regulations and lack of operational experience. This study aims to find a way for UAM to operate in reality, and for this purpose, the defense system for evaluating the safety of civil aviation was applied as SMS. In addition, the technical elements of the maneuvering of UAM aircraft were reviewed from a flight perspective. As a result, a unexpected problem was derived in the take-off and landing stage of the current airspace, flight corridor, and operation stage. Based on this, alternatives were derived and suggested to successfully complete the UAM demonstration project by FOSA which is Risk assessment Tool. Therefore, if the direction of UAM research is set by citing the results of this study, it is expected to contribute to the safe operation of UAM.

• Science of Emotion and Sensibility
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• v.21 no.4
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• pp.63-76
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• 2018

The purpose of this study was to investigate the effect of contact type textile electrode structure on heart activity signal acquisition for smart healthcare. In this study, we devised six contact type textile electrodes whose electrode size and configuration were manipulated for measuring heart activity signals using computerized embroidery. We detected heart activity signals using a modified lead II and by attaching each textile electrode to the chest band in four healthy male subjects in a standing static posture. We measured the signals four times repeatedly for all types of electrodes. The heart activity signals were sampled at 1 kHz using a BIOPAC ECG100, and the detected original signals were filtered through a band-pass filter. To compare the performance of heart activity signal acquisition among the different structures of the textile electrodes, we conducted a qualitative analysis using signal waveform and size as parameters. In addition, we performed a quantitative analysis by calculating signal power ratio (SPR) of the heart activity signals obtained through each electrode. We analyzed differences in the performance of heart activity signal acquisition of the six electrodes by performing difference and post-hoc tests using nonparametric statistic methods on the calculated SPR. The results showed a significant difference both in terms of qualitative and quantitative aspects of heart activity signals among the tested contact type textile electrodes. Regarding the configurations of the contact type textile electrodes, the three-dimensionally inflated electrode (3DIE) was found to obtain better quality signals than the flat electrode. However, regarding the electrode size, no significant difference was found in performance of heart signal acquisition for the three electrode sizes. These results suggest that the configuration method (flat/3DIE), which is one of the two requirements of a contact type textile electrode structure for heart activity signal acquisition, has a critical effect on the performance of heart activity signal acquisition for wearable healthcare. Based on the results of this study, we plan to develop a smart clothing technology that can monitor high-quality heart activity without time and space constraints by implementing a clothing platform integrated with the textile electrode and developing a performance improvement plan.