• ETRI Journal
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• v.44 no.6
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• pp.977-990
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• 2022

This study proposes a novel method for identifying the primary conspirators involved in terrorist activities. To map the information related to terrorist activities, we gathered information from different sources of real cases involving terrorist attacks. We extracted useful information from available sources and then mapped them in the form of terrorist networks, and this mapping provided us with insights in these networks. Furthermore, we came up with a novel centrality measure for identifying the primary conspirators of a terrorist attack. Because the leaders of terrorist attacks usually direct conspirators to conduct terrorist activities, we designed a novel algorithm that can identify such leaders. This algorithm can identify terrorist attack leaders even if they have less connectivity in networks. We tested the effectiveness of the proposed algorithms on four real-world datasets and conducted an experimental evaluation, and the proposed algorithms could correctly identify the primary conspirators and leaders of the attacks in the four cases. To summarize, this work may provide information support for security agencies and can be helpful during the trials of the cases related to terrorist attacks.

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.277-291
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• 2003

This study was designed to examine the kinematic factors in the phase during the marche fente motion. For this study, the subjects were 5 elite male fencing players. The direct linear transformation (DLT) method was used in calculating 3-D coordinate of the digitized body parts. The cubic spline function was used for smoothing and the kinematic data for displacement, velocity, angle variables were calculated for Kwon3d ver 2.1. And the following conclusions were drawn; 1. It show that the marche phase appeared to longer time than the pante phase In the performance time. For the fast attack, it showed that the subjects should be moving in a short stride width. 2. For a fast and stable movement posture in the marche phase, the vertical change of COG must be maintain the same position as possible, but all subjects appeared to decrease the COG because of a excessive the knee flection. 3. In the COG velocity change, all the subjects showed to the same change in both the marche and the fente phase. However in the attack extremity velocity, it increased velocity in order of upper arm, fore arm, and hand in the marche phase, but it showed different velocity among each subjects at the moment of stabbing. So that in order to do effective stabbing, they have to extend their upper extremity max and do faster the distal segment than the proximal segment. 4. It showed to take a fast and stable movement, because some subjects showed the big anteroposterior angle of the trunk flexed max shoulder angle and elbow angle of their attack arm and the other upper extremity.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.5
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• pp.9-17
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• 2015

The development of wireless communication technology and change in the ICT market has led to the development of the M2M service and technology. Under these circumstances, the M2M environment has been the focus of communication environment construction between machines without control or direct intervention of human being. With characteristics of wireless communication environment, the possibility of being exposed to numerous security threats and safe communication security technology have becoming an issue an important requirements for problems such as data exposure, forgery, modulation, deletion, and privacy. This research analyzes requirements of trapdoor collision hash, generates keys between groups under the M2M environment by using the specificity of trapdoor, and suggests technology to exchange keys with session keys. Further, it also suggests techniques to confirm authentication of device and gateway in accordance with group key generation. The techniques herein suggested are confirmed as safe methods in that they have attack resistance such as Masquerade Attack, Man-in-the-Middle Attack, and Replay Attack in the group communication block by using the speciality of collision message and collision hash.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.6
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• pp.1159-1174
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• 2014

As the use of smartphones and tablet PCs has exploded in recent years, there are many occasions where such devices are used for treating sensitive data such as financial transactions. Naturally, many types of attacks have evolved that target these devices. An attacker can capture a password by direct observation without using any skills in cracking. This is referred to as shoulder surfing and is one of the most effective methods. There has been only a crude definition of shoulder surfing. For example, the Common Evaluation Methodology(CEM) attack potential of Common Criteria (CC), an international standard, does not quantitatively express the strength of an authentication method against shoulder surfing. In this paper, we introduce a shoulder surfing risk calculation method supplements CC. Risk is calculated first by checking vulnerability conditions one by one and the method of the CC attack potential is applied for quantitative expression. We present a case study for security-enhanced QWERTY keyboard and numeric keypad input methods, and the commercially used mobile banking applications are analyzed for shoulder surfing risks.

• Journal of computational fluids engineering
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• v.9 no.1
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• pp.41-47
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• 2004

A successful store separation analysis tool, MSAP(Multi-body Separation Analysis Program) has been applied to F/A-18C/JDAM CFD Challenge Ⅱ. The challenge was devised to challenge CFD community to use CFD methodologies to predict and match the trajectory of a JDAM MK-84 separating from F/A-l8C. Trajectory simulations for two flight conditions were performed. Comparison between computed and measured flight trajectories for both conditions shows a good agreement.

• 한국전산유체공학회:학술대회논문집
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• 2003.08a
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• pp.89-94
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• 2003

A successful store separation analysis tool, MSAP(Multi-body Separation Analysis Program) has been applied to F/A-18C/JDAM CFD Challenge II. The challenge was devised to challenge CFD community to use CFD methodologies to predict and match the trajectory of a JDAM MK-84 separating from F/A-l8C. Trajectory simulations for two flight conditions were performed. Comparison between computed and measured flight trajectories for both conditions shows a good agreement.

• YAKHAK HOEJI
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• v.16 no.4
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• pp.155-161
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• 1972

The hydrolysis of phenobarbital is decelerated in alkaline solution by betacyclodextrin. The betacyclodextrin inhibits the degradation of phenobarbital up to 1.5 fold in the system containing 1% betacyclodextrin. The degradation mechanism in systems containing betacyclodextrin is the same that in system without complexing agent, although the rate constants are different. The pH dependence of the hydrolysis rate deceleration is compared with the ionization percent of betacyclodextrin. The results indicate that a direct relationship does not exist between the ionization of betacyclodextrin. It seems reasonable therefore that the phenobarbital undergoes a stable complex with betacyclodextrin and complex formation would provide a better shield for the phenobarbital from hydroxyl ion attack.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.7
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• pp.669-674
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• 2011

In this paper, a method for reduction of spurious signal in Digital RF Memory(DRFM) is proposed. Spurious response is a major performance issue of DRFM. This method is based on mixing a random phase LO signal into input IF signal and sampling it. The random phase LO signal is generated by high speed phase shifting characteristic of Direct Digital Synthesizer(DDS). Through this technique, we achieved an enhancement of 5~10 dB of spurious response.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.411-414
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• 1998

In this paper, the silicon-nitride membrane structure for IR sensor was fabricated through the etching and the direct bonding. The PT layer as a IR detection layer was deposited on the membrane and its characteristics were measured. The attack of PT layer during the etching of silicon wafer as well as the thermal isolation of the IR detection layer can be solved through the method of bonding/etching of silicon wafer. Because the PT layer of c-axial orientation rained thermal polarization without polling, the more integration capability can be achieved. The surface roughness of the membrane was measured by AFM, the micro voids and the non-contacted area were inspected by IR detector, and the bonding interface was observed by SEM. The polarization characteristics and the dielectric characteristics of the PT layer were measured, too.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.10
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• pp.815-819
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• 1998

The silicon-nirtide membrane structure for IR sensor was fabricated through the etching and the direct bonding. The PRO($PbTiO_3$ ) layer for a IR detection was coated on the membrane and its characteristics were measured. The a attack of PTO layer during the etching of silicon wafer as well as the thermal isolation of the IR detection layer were eliminated through the method of bonding/etching of silicon wafer. The surface roughness of the membrane was measured by AFM, the micro voids and the non-contacted area were inspected by the PTO layer were measured, too.