• Journal of the Korea Society of Computer and Information
• /
• v.17 no.12
• /
• pp.179-185
• /
• 2012

This paper proposes a design of RSIDS(RST and SVM based Intrusion Detection System) using RST(Rough Set Theory) and SVM(Support Vector Machine) algorithm. The RSIDS consists of PrePro(PreProcessing) module, RRG(RST based Rule Generation) module, and SAD(SVM based Attack Detection) module. The PrePro module changes the collected information to the data format of RSIDS. The RRG module analyzes attack data, generates the rules of attacks, extracts attack information from the massive data by using these rules, and transfers the extracted attack information to the SAD module. The SAD module detects the attacks by using it, which the SAD module notifies to a manager. Therefore, compared to the existing SVM, the RSIDS improved average ADR(Attack Detection Ratio) from 77.71% to 85.28%, and reduced average FPR(False Positive ratio) from 13.25% to 9.87%. Thus, the RSIDS is estimated to have been improved, compared to the existing SVM.

• Journal of the Korean Geotechnical Society
• /
• v.25 no.7
• /
• pp.11-21
• /
• 2009

This paper presents a new high-performance supporting system of the shallow tunnel. In order to perform this research the mechanism of new supporting system is suggested and compared with the conventional existing supporting system. It is found that the new supporting system as pre-support system has several advantages such as improvement of ground before tunnel excavation and increment of capacity of the tunnel support. The construction procedures of this supporting system are also reviewed. In addition, the numerical simulation is carried out to evaluate the new supporting system. It is found that the new high-performance supporting system is very applicable in shallow depth tunnel such as portal area, tunnel in soil and weak zone, and so on.

• Journal of the Korean GEO-environmental Society
• /
• v.13 no.5
• /
• pp.25-33
• /
• 2012

In this study, gathered measuring data at fields constructed by IPS(Innovative Prestressed Support) system controls the ground displacement and improves the constructability of earth work and structure work greatly, and compared with horizontal displacement calculated by Elasto-plastic analysis program(EXCAV/W). As the result, displacement of calculated by pre-loading data is reduced 13.2% average of general method, and measuring displacement is also reduced 26.7% average of general method. Therefore that IPS system is more safe than conventional strut method in contrast to displacement of underground wall. In addition, horizontal displacement is reduced through the pre-loading effect used by IPS system.

• Korean Journal of Computational Design and Engineering
• /
• v.17 no.2
• /
• pp.123-131
• /
• 2012

The requirements for computational resources to perform the structural analysis are increasing rapidly. The size of the current analysis problems that are required from practical industry is typically large-scale with more than millions degrees of freedom (DOFs). These large-scale analysis problems result in the requirements of high-performance analysis codes as well as hardware systems such as supercomputer systems or cluster systems. In this paper, the pre- and post-processing system for supercomputing based large-scale structural analysis is presented. The proposed system has 3-tier architecture and three main components; geometry viewer, pre-/post-processor and supercomputing manager. To analyze large-scale problems, the ADVENTURE solid solver was adopted as a general-purpose finite element solver and the supercomputer named 'tachyon' was adopted as a parallel computational platform. The problem solving performance and scalability of this structural analysis system is demonstrated by illustrative examples with different sizes of degrees of freedom.

• Tunnel and Underground Space
• /
• v.5 no.2
• /
• pp.104-113
• /
• 1995

Shear strength of the discontinuity on which the pre-failure of rock slope was occurred during surface excavation was measured through the direct shear test using core samples obtained in-situ. Internal friction angle was increased as the roughness of discontinuity surface(JRC) was increased. Results of the tilt test using core samples of higher JRC also showed very similar trend as those of the direct shear test. When the samples replicated from natural cores were used int he tilt test, results of friction angles showed almost perfect continuation of the residual friction angles from the direct shear test. However, when the gouge material existed in the discontinuity the internal friction angle strongly depended upon the rate of filling thickness to the height of asperity irrespective of the JRC. Based on the results of both direct shear test and tilt test internal friction angle and cohesion of discontinuity, which reflect the in-situ conditions fo pre-sliding failure and also can be used for the optimum design of support system, were assessed. Two kinds of support measures which were expected to increase the stability of rock slope were considered; lowering of slope face angle and installation of rock cable. But, it was found that the first method might lead to more unstable conditions of rock slope when the cohesion of discontinuity plane was negligibly low and in that case the support systems of any kind which could exert actual resisting force were needed to ensure the permanent stability of rock slope.

• Journal of KIISE:Information Networking
• /
• v.33 no.3
• /
• pp.193-200
• /
• 2006

The security feature is essential in wireless sensor network such as intrusion detection or obstacle observation. Sensor nodes must have shared secret between nodes to support security such as privacy. Many methods which provide key pre-distribution need too many keys or support poor security. To solve this problem, probabilistic key pre-distribution is proposed. This method needs a few keys and use probabilistic method to share keys. However, this method does not guarantee key sharing between nodes, and neighbor nodes nay not communicate each other. It leads to waste of network resource such as inefficient routing, extra routing protocol. In this paper, we propose new key distribution method using quorum system which needs a few keys and guarantee key sharing between nodes. We also propose extension of the method which needs fewer keys and guarantee key sharing when node deployment knowledge is well known.

• Korean Journal of Human Ecology
• /
• v.20 no.2
• /
• pp.327-338
• /
• 2011

In order to promote and comprehend marriage immigrants' culture, it is essential to understand the life of their families in their counties. For this study, data by a Philippine CFO(Commission on Filipino Overseas) has been analyzed, and the study researcher has attended an educational program run by the PDOS(Pre-Departure Orientation Seminar). Also, in order to understand the immigrants' families in their country, interviews have been done with some of the CFO employees, people arranged to immigrate to Korea through marriage, and female immigrants who are married. First, Filipino females have a positive attitude toward marriage with a foreign male. Most immigrants are from the rural parts of their country, and their families tend to rely on their daughters more than their sons. Therefore, they decide to marry Korean males and immigrate in order to support their families. However many of them do not have enough information about Korea. Second, Philippine's family system is of bilateral kinship, and traditionally, men and women are treated equally. Therefore, Filipino females tend to be well-educated, outgoing, and vibrant. Thus, they can create an active role in married life for themselves and support their family members. Lastly, based on videos and class materials on the topic of domestic violence that are used in the pre-educational programs for females planning to immigrate to Korea, the content of the program is to be revised.

• Journal of Aerospace System Engineering
• /
• v.12 no.3
• /
• pp.38-44
• /
• 2018

Military aircraft may have fatigue cracks in structurally weak areas due to multiple factors such as the accumulation of flight time while perform various missions and unpredictable air conditions. As a fatigue crack progresses, there is a risk that the structure will be destroyed in extreme cases, which can have a significant impact on flight safety. In this study, a cracking phenomenon was observed during the periodic inspection the inner support of the fairing, which is installed to protect the connection between the wing and the body of the aircraft. Therefore, a study on a series of quality improvement processes for reformation was described. In order to identify the causes of cracks, pre-load generation occurrence during the wing assembly process was investigated and a fracture analysis was performed. Also, the design of the support structure was suggested in terms of preventing recurrence of cracks. The structural integrity was verified using a stress and fatigue life analysis.

• Geomechanics and Engineering
• /
• v.11 no.2
• /
• pp.177-195
• /
• 2016

To secure the stability of geotechnical infrastructures and minimize failures during the construction process, a number of support systems have been introduced in the last several decades. In particular, stabilization methods using steel bars have been widely used in the field of geotechnical engineering. Rock bolt system is representative support system using steel bars. Pre-stressing has been applied to enhance reinforcement performance but can be released because of the failure of head or anchor sections. To overcome this deficiency, this paper proposes an innovative support system that can actively reinforce the weak ground along the whole structural element by introducing an active tension bolt containing a spring unit to the middle of the steel bar to increase its reinforcement capacity. In addition, the paper presents the support mechanism of the active tension bolt based on a theoretical study and employs an experimental study to validate the performance of the proposed active tension bolt based on a down-scaled model. To examine the feasibility of the active tension unit in a pillar, the paper considers a pullout test and a small-scale experimental model. The experimental results suggest the active tension bolt to be an effective support system for pillar reinforcement.

• Journal of Korean Physical Therapy Science
• /
• v.12 no.4
• /
• pp.33-41
• /
• 2005

The purpose of this report was to describe the gait pattern and parameters of the complicated bilateral amputee with right transtibial and left tarsometatarsal amputation. Using a Vicon 370 three dimensional gait analysis system, the gait analysis was performed at pre and post-test. Treadmill Training with 15 degree, incline was practiced for 8weeks, 3times per week. In linear parameters, the Velocity, Stride length and Single limb support were increased than pre-test. but Cadence and Double limb support were less post-test than pre-test. In kinematics, the maximal pelvic tilt angle showed right side $21.87^{\circ}$, left side $20.67^{\circ}$ at pre-swing phase, and decreased as compared with pre-test. Especially, the inimal hip flexion angle showed right side $-6.83^{\circ}$, left side $1.52^{\circ}$ at pre-swing phase and increased as compared with pre-test. The maximal knee flexion angle disclosed right side $2.66^{\circ}$, left side $21.71^{\circ}$ at stance phase, and decreased as compared with pre-test. In kinetics, the hip extension moment on initial contact stage was right side 0.938NM/Kg, left side 0.09NM/Kg, which was impaired compared with normal person.