• International Journal of Aerospace System Engineering
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• v.2 no.1
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• pp.47-52
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• 2015

The transient phenomenon of self-powered energy-harvesting is assessed using a bond-graph method. The bond-graph is an energy-based approach to describing physical-dynamic systems. It shows power flow graphically, which helps us understand the behavior of complicated systems in simple terms. Because energy-harvesting involves conversion of power in mechanical form to the electrical one, the bond-graph is a good tool to analyze this power flow. Although the bond-graph method can be used to calculate the dynamics of combining mechanical and electrical systems simultaneously, it has not been used for harvesting analysis. We demonstrate the usability and versatility of bond-graph for not only steady analysis but also transient analysis of harvesting.

• ETRI Journal
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• v.41 no.5
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• pp.574-584
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• 2019

A new Mirai variant found recently was equipped with a dynamic update ability, which increases the level of difficulty for DDoS mitigation. Continuous development of 5G technology and an increasing number of Internet of Things (IoT) devices connected to the network pose serious threats to cyber security. Therefore, researchers have tried to develop better DDoS mitigation systems. However, the majority of the existing models provide centralized solutions either by deploying the system with additional servers at the host site, on the cloud, or at third party locations, which may cause latency. Since Internet service providers (ISP) are links between the internet and users, deploying the defense system within the ISP domain is the panacea for delivering an efficient solution. To cope with the dynamic nature of the new DDoS attacks, we utilized an unsupervised artificial neural network to develop a hierarchical two-layered self-organizing map equipped with a twofold feature selection for DDoS mitigation within the ISP domain.

• International Journal of Computer Science & Network Security
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• v.22 no.11
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• pp.291-293
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• 2022

The implementation of the legal mechanism to protect the rights and interests of entrepreneurs in Russia has its unique features. When the rights and interests of a businessman are threatened with infringement, specific legal remedies may be applied, by means of which the violated rights and interests are restored and, thereby, the opportunity to resume entrepreneurial activity is created. The paper explores extrajudicial ways to protect the rights and interests of entrepreneurs in Russia. The study analyzes the forms of self-help, arbitral tribunal, resolution of applications and complaints by executive authorities, the notariate, and work with the business ombudsman and civil society institutions.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1540-1542
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• 2010

국방분야의 무인지상무기체계(Unmanned Ground Vehicles)는 소프트웨어 결함 발생시 유인무기체계와 달리 응급 조치를 수행할 수 있는 사람이 탑승하지 않기 때문에 임무 수행에 치명적인 영향을 미칠 수 있다. 따라서, 무인지상무기체계에 탑재되는 내장형 SW의 신뢰성 있는 임무 수행을 위한 방법을 필요로 한다. 본 연구에서는 무선 Ad-hoc 네트워크로 연결된 UGV의 SW 결함을 원격으로 진단하고, 치료하기 위한 방법에 대해 연구하였다. 국방분야의 무인무기체계에 탑재된 내장형 SW의 신뢰성을 높이기 위해 적용가능하다.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.651-654
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• 2021

Face anti-spoofing (FAS) techniques play a significant role in the defense of facial recognition systems against spoofing attacks. Existing FAS methods achieve the great performance depending on annotated additional modalities. However, labeling these high-cost modalities need a lot of manpower, device resources and time. In this work, we proposed to use self-transforming modalities instead the annotated modalities. Three different modalities based on frequency domain and temporal domain are applied and analyzed. Intuitive visualization analysis shows the advantages of each modality. Comprehensive experiments in both the CNN-based and transformer-based architecture with various modalities combination demonstrate that self-transforming modalities improve the vanilla network a lot. The codes are available at https://github.com/chenmou0410/FAS-Challenge2021.

• Journal of electromagnetic engineering and science
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• v.17 no.2
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• pp.105-107
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• 2017

The self-biasing circuit through a feedback resistor is applied to a gallium nitride (GaN) distributed power amplifier (PA) monolithic microwave circuit (MMIC). The self-biasing circuit is a useful scheme for biasing depletion-mode compound semiconductor devices with a negative gate bias voltage, and is widely used for common source amplifiers. However, the self-biasing circuit is rarely used for PAs, because the large DC power dissipation of the feedback resistor results in the degradation of output power and power efficiency. In this study, the feasibility of applying a self-biasing circuit through a feedback resistor to a GaN PA MMIC is examined by using the high operation voltage of GaN high-electron mobility transistors. The measured results of the proposed GaN PA are the average output power of 41.1 dBm and the average power added efficiency of 12.2% over the 6-16 GHz band.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.679-687
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• 2020

This study quantitatively analyzed the effects of self-efficacy in the workplace on job-stress and work-life balance (WLB) using a structural equation model (SEM) to seek ways to increase the WLB. Because the current government promotes the 52-hour weekly policy, WLB that refers to the balance between work and life that is used throughout society. In addition, self-efficacy, which was used mainly in the home and education system, has expanded its scope of application, and efforts to increase it in the workplace are working as demand for the times. The observation variables to be included in the SEM were collected from a questionnaire of 5,454 adults, and AMOS 21 was used for statistical analysis. As a result of the analysis, self-efficacy in the workplace has a negative correlation with stress, and a higher self-efficacy means a higher WLB. The results of this study did not show that the more workers are passionate about their work in the workplace due to work-oriented thinking and behavior rather than home had a lower WLB. In addition, these results can be used to analyze the WLB policy in the ROK Army.

• Korean Security Journal
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• no.4
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• pp.257-277
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• 2001

The purpose of this study was to examine effects of practicing martial arts upon job performance of employees engaged in security industry. For positive investigation, 400 employees were questioned using some questionnaires; as a result, we obtained the following conclusion of the relation between the extent of the practicing martial art and the ability of performing their jobs. First, the more they practice martial art, the better and higher their mental health and psychological stability more than control group. Especially, when crime is reported to them or they arrest a criminal taken in an act of crime, the degree of their anxiety was low and they strongly expose self-confidence, their view of moral achievement and their sense of morality. Second, the more they practice martial art, the higher their ability of arrestment a criminal in an act and self-defense is. Because practicing martial art make their vital power and physical strength promoted. Third, the more they practice martial art, the more sincere the trust and friendship among colleagues are. As well they seem to feel strong solidarity oneanother. But practicing martial art appeared that it doesnt have an effect on coping with complications among generations and the gaps between master sergeant and them. Fourth, employees engaged in security industry practicing martial art is not only used in job performance merely as a technique; it is also effective on the mind that it make their anxiety dissolved and give them self-confidence.

• 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 Multimedia Information System
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• v.9 no.1
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• pp.11-20
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• 2022

In this paper, we have recently created self-driving cars and self-parking systems in human-friendly cars that can provide high safety and high convenience functions by recognizing the internal and external situations of automobiles in real time by incorporating next-generation electronics, information communication, and function control technologies. And with the development of connected cars, the ITS (Intelligent Transportation Systems) market is expected to grow rapidly. Intelligent Transportation System (ITS) is an intelligent transportation system that incorporates technologies such as electronics, information, communication, and control into the transportation system, and aims to implement a next-generation transportation system suitable for the information society. By combining the technologies of connected cars and Internet of Things with software features and operating systems, future cars will serve as a service platform to connect the surrounding infrastructure on their own. This study creates a research methodology based on the Enhanced Security Model in Self-Driving Cars model. As for the types of attacks, Availability Attack, Man in the Middle Attack, Imperial Password Use, and Use Inclusive Access Control attack defense methodology are used. Along with the commercialization of 5G, various service models using advanced technologies such as autonomous vehicles, traffic information sharing systems using IoT, and AI-based mobility services are also appearing, and the growth of smart transportation is accelerating. Therefore, research was conducted to defend against hacking based on vulnerabilities of smart cars based on artificial intelligence blockchain.