• Journal of Applied Reliability
• /
• v.12 no.1
• /
• pp.1-12
• /
• 2012

The quality of a part has directly effect on part reliability. In the basis of MIL-HDBK-217F model, it is the determined rule that part's quality level should follow its nominal one written in its specification. If quality information is unknown, quality level of the part should be determined as 'Lower'. However, the prediction model is said to be short in reflecting parts applying 'state-of-the-art' technology and result in over-estimated failure rate by some reliability-related authorities or research institutes. In this study, the reliability prediction results by the model of MIL-HDBK-217F and Telcordia SR-332 are compared and analyzed to verify whether the statement is reasonable or not.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.13 no.9
• /
• pp.4484-4501
• /
• 2019

In this paper, we put forward a delay-aware secure maximum distance separable (MDS) coded caching scheme to resist the eavesdropping attacks for device-to-device (D2D) content sharing by combining MDS coding with distributed caching. In particular, we define the average system delay to show the potential coupling of delay-content awareness, and learn the secure constraints to ensure that randomly distributed eavesdroppers cannot obtain enough encoded packets to recover their desired contents. Accordingly, we model such a caching problem as an optimization problem to minimize the average system delay with secure constraints and simplify it to its convex relaxation. Then we develop a delay-aware secure MDS coded caching algorithm to obtain the optimal caching policy. Extensive numerical results are provided to demonstrate the excellent performance of our proposed algorithm. Compared with the random coded caching scheme, uniform coded caching scheme and popularity based coded caching scheme, our proposed scheme has 3.7%, 3.3% and 0.7% performance gains, respectively.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.6
• /
• pp.2204-2224
• /
• 2021

This paper studies secure wireless transmission from a multi-antenna transmitter to a single-antenna intended receiver overheard by multiple eavesdroppers with considering the imperfect channel state information (CSI) of wiretap channel. To enhance security of communication link, the artificial noise (AN) is generated at transmitter. We first design the robust joint optimal beamforming of secret signal and AN to minimize transmit power with constraints of security quality of service (QoS), i.e., minimum allowable signal-to-interference-and-noise ratio (SINR) at receiver and maximum tolerable SINR at eavesdroppers. The formulated design problem is shown to be nonconvex and we transfer it into linear matrix inequalities (LMIs). The semidefinite relaxation (SDR) technique is used and the approximated method is proved to solve the original problem exactly. To verify the robustness and tightness of proposed beamforming, we also provide a method to calculate the worst-case SINR at eavesdroppers for a designed transmit scheme using semidefinite programming (SDP). Additionally, the secrecy rate maximization is explored for fixed total transmit power. To tackle the nonconvexity of original formulation, we develop an iterative approach employing sequential parametric convex approximation (SPCA). The simulation results illustrate that the proposed robust transmit schemes can effectively improve the transmit performance.

• Convergence Security Journal
• /
• v.23 no.5
• /
• pp.189-197
• /
• 2023

The Republic of Korea Army (ROK Army) is currently developing the Army Synthetic Battle Training System (ASBTS) by 2026 and will use it to advance division-level LVC integrated training. This study proposes a way to improve the effectiveness and efficiency of training by applying VR/AR technology to the ASBTS. To this end, we analyzed cases of VR/AR technology use in the defense field in advanced countries and the ROK military. As a result, we confirmed that the effectiveness and efficiency of training can be improved when the training system is converted to an immersive system. Accordingly, we selected and presented defense training subjects to be applied to VR/AR technology, considered the development direction for applying VR/AR technology to the ASBTS, and proposed a way to apply VR/AR technology to the ASBTS.

• The Korean Journal of Archival Studies
• /
• no.62
• /
• pp.259-286
• /
• 2019

This study draws out the implications based on the analysis of the U.S. Army's practices(Army Military Human Resource Record(AMHRR) and interactive Personnel Electronic Records Management System(iPERMS), Archival Information Service) and applies it to our military by paying attention to the importance of military personnel records and the thorough records management that are the foundation for promoting the welfare service projects of those who have committed to the nation. Through these, it is expected to contribute to the smooth promotion of veteran welfare projects and to create a climate that honors the military at the bottom of society in the future.

• Smart Structures and Systems
• /
• v.32 no.4
• /
• pp.195-205
• /
• 2023

The contact acoustic emission (AE) monitoring system is time-consuming and costly for monitoring concrete structures in large scope, in addition, the great difference in acoustic impedance between air and concrete makes the detection process inconvenient. In this work, we broaden the conventional AE source localization method for concrete to the non-contact (air-coupled) micro-electromechanical system (MEMS) microphones array, which collects the energy-rich leaky Rayleigh waves, instead of the relatively weak P-wave. Finite element method was used for the numerical simulations, it is shown that the propagation velocity of leaky Rayleigh waves traveling along the air-concrete interface agrees with the corresponding theoretical properties of Lamb wave modes in an infinite concrete slab. This structures the basis for implementing a non-contact AE source location approach. Based on the experience gained from numerical studies, experimental studies on the proposed air-coupled AE source location in concrete slabs are carried out. Finally, it is shown that the locating map of AE source can be determined using the proposed system, and the accuracy is sufficient for most field monitoring applications on large plate-like concrete structures, such as tunnel lining and bridge deck.

• Journal of the military operations research society of Korea
• /
• v.30 no.2
• /
• pp.32-49
• /
• 2004

The Tactical Data Link System is a standardized communication link to exchange and interface positional, situational information, command and control in real time. It has been evaluated that this Link would play an important role for tactical interoperability, situation awareness, and execution of joint operations in the future war. But considering the rapidly changing war situations, even though being admitted the necessity of the Tactical Data Link System of Army helicopter, one of superpowers in the Army, substantially we don't still have any concrete concept to build it. Therefore, this work presents how to embody the Tactical Data Link System through computer-aided system engineering on the base of Tactical Data Link System operating concept analysis of helicopters-ground units.

• Convergence Security Journal
• /
• v.22 no.4
• /
• pp.45-51
• /
• 2022

The interview for the selection of army officers had a lot of interview questions and topical content, so it was difficult to prepare for military officers applicants. Applicants who pass the written evaluation will be selected after passing the final interview. However, as the number of applicants is relatively decreasing due to the improvement of the treatment of the soldiers, it is expected that there will be a shortage of executives to operate advanced equipment in the future. To ensure that excellent applicants do not drop out of the final interview, we intend to provide interview-related data and suggest a unique interview direction for applicants.

• (The)Study of the Eastern Classic
• /
• no.70
• /
• pp.257-301
• /
• 2018

The purpose of the study is to examine righteous army activity and combat in Hapcheon during the Imjin invasion period. The resulting conclusions are as follows. First, Chung In-hong raised a righteous army in Hapcheon and Kim Myeon raised an army in Goryeong. Chung In-hong commanded the army and fought against Japanese army with a leadership of knowing the enemy and himself, and Kim Myeon commanded the army and fought against Japanese military with a leadership of harmony. Second, battles of Chung In-hong's righteous army are the first Mugye battle, the ambush battle in Sawon-dong, the Chogye Majin battle, the Aneon battle, and the third Seongju Castle battle. Battles of Kim Myeon's righteous army are the Yeongang battle, the Gaesanpo battle, the second Mugye battle, the Ucheok-hyeon battle, the Jirye battle, and the Sarangam battle. Battles that Chung In-hong and Kim Myeon united and fought are the first and second Seongju Castle battles. In Jeongyu Jaeran, Chung In-hong played a role of Jodosa who takes charge of provisions in the right area of Gyeongsang. In addition, Hapcheon was the access road and transport route where Japanese army entered Jeolla-do. Third, participation and role of Ming troops are part of restraint device against Japanese army with military tactics of ii chei(using foreigners to control foreigners) to remove Japanese army from Joseon and defend Yodong. After a victory of Li Rusong in Pyeongyang Castle in January, 1593(the 26th year of Seongjo), Ming troops pursued practical interest through peace talks rather than active battles. When there was practically Siege of Jinju, Yujeong troops of Ming entered with hand-to-hand martial arts of Sacheon soldiers in late June, 1593, but did not participate because they should wait for orders of Gyeongnyak Song Eung-chang and Admiral Li Rusong. Fourth, in the Imjin invasion period, Joseon suffered terrible damage such as ruin of the whole country by invasion of Japanese army and in need of aid of military rice from Ming troops, but righteous armies and the royal forces in each area cooperated so defeated Japanese army. It is understood through a case of Hapcheon in the right area of Gyeongsang. Especially, Joseon did not succumb to pressure of Ming troops that used full powers to two aspects such as settlement and battle with Japan during the war, and did not lose national confidence and pride by showing a fighting will to fight against Japanese army to the end with independence. Such a spiritual culture originated from homeland protection and loyalty to the king, and is national spirit of resistance that sublimates the united mind and spirit of community to protect a country against foreign invasion.

• Convergence Security Journal
• /
• v.19 no.1
• /
• pp.127-133
• /
• 2019

Officers and NCOs are in charge of complaints Army. Most of the complainants are civilians, so if the active duty is treated as complaints, their expertise is limited and it is difficult to think in terms of civilians. In order to overcome this problem, it is suggested that private career experts should be dedicated to complaints.