• Journal of IKEEE
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• v.24 no.2
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• pp.543-549
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• 2020

As the importance of security increases in various fields, research on a random number generator (RNG) used for generating an encryption key, has been actively conducted. A high-quality RNG is essential to generate a high-performance encryption key, but the initial pseudo-random number generator (PRNG) has the possibility of predicting the encryption key from the outside even though a large amount of hardware resources are required to generate a sufficiently high-performance random number. Therefore, the demand of high-quality true random number generator (TRNG) generating random number through various noises is increasing. This paper examines and compares the representative TRNG methods based on metastable-based and ring-oscillator-based TRNGs. We compare the methods how the random sources are generated in each TRNG and evaluate its performances using NIST SP 800-22 tests.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.1
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• pp.108-115
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• 2011

Virtual Robot Education System (VRES), which is for programming education with a Lego Mindstorm NXT robot, is designed and implemented. Through this system, program learners can edit source code, compile, download it into the robot, and run their executive program. In order to observe it, the system includes web cameras and provide monitoring services. Thus, students are able to verify the operation of robot into which they download their program in detail and to debug if necessary. In addition, we design a new simple user-friendly programming language and a corresponding compiler for it. With those tools, learner can more easily create programs for NXT robot and test them than Java language. A educator can control and manage the robot for the subject of a class with direct control mode of our system. Therefore, the proposed system is able to support students to learn robot programming during or after regular classes with web browsers through Internet.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.11
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• pp.955-962
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• 2016

In recent years, there have been emerging needs for standardized software-based motion application development for better scalability and support for multiple operation modes for small quantity batch production. Although a software-based motion system provides a basis for constructing multiple operation modes on a machine, it is not easy to construct such systems without tools for defining multiple motion operation modes and standardized mode-change protocols. This paper proposes a motion recipe concept to overcome this problem; the concept includes the authoring of multiple motion operation modes using the PLCopen-compliant motion function blocks and communication protocols to trigger operation mode changes from an external interface. The motion recipe was implemented by extending an IEC 61131-3 compliant IDE called Beremiz, and the correctness of the motion recipe-based application behavior was verified on a real testbed.

• The Journal of the Korea Contents Association
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• v.11 no.10
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• pp.30-40
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• 2011

Recently, together with the development of wireless communication technologies and the wide use of smart phones, the demand of the next generation mobile communication has been increased. To construct the next generation mobile communication platform efficiently for a short period from protocol development phase to protocol stability phase, an protocol analyzer is required to verify and analyze the protocol. In this paper, we propose the protocol analyzer of LTE network which is the leader of the next generation mobile communication platforms. The protocol analyzer is a software based agent-server architecture and uses XML metadata which defines intercommunication messages to analyze the protocol of the next generation mobile communications. We can analysis the encoding messages applied to LTE network using the loading of the decoding library. We verify the superiority of the proposed analyzer through an integrated test with LTE network.

• The KIPS Transactions:PartC
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• v.12C no.6 s.102
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• pp.827-838
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• 2005

DDoS (Distributed Denial of Service) attack is a critical threat to current Internet. To solve the detection and response of DDoS attack on BcN, we have investigated detection algorithms of DDoS and Implemented anomaly detection modules. Recently too many technologies of the detection and prevention have developed, but it is difficult that the IDS distinguishes normal traffic from the DDoS attack Therefore, when the DDoS attack is detected by the IDS, the firewall just discards all over-bounded traffic for a victim or absolutely decreases the threshold of the router. That is just only a method for preventing the DDoS attack. This paper proposed the mechanism of response for the legitimated clients to be protected Then, we have designed and implemented the statistic based system that has the automated detection and response functionality against DDoS on Linux Zebra router environment.

• Korean Journal of Construction Engineering and Management
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• v.12 no.3
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• pp.11-21
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• 2011

The most critical issue in free-form buildings is how to construct the free-formed exterior facade panels. Their geometric complexity delivers many cons and problems in fabricating and constructing their shapes. To construct a free-form building, first of all, its skin has to be chopped into small pieces, which is called panelization. After panelization, the panels go through an optimization process to construct them economically. The panel's geometries are modified or regenerated through this optimization process. In this study, the panel optimization process of free-form buildings are performed through a case study. The panel shapes of the case study are modeled with Digital Project. To test the constructability of the various panels, 8 mock-up panels are made and laser scanning technology is applied to measure the preciseness of the panels manufactured in comparison with their original design.

• KIISE Transactions on Computing Practices
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• v.21 no.2
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• pp.148-153
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• 2015

In our domestic software industries, it is focused on such a high quality development/ testing process, maturity measurement, and so on. But the real industrial fields are still working on a code-centric development. Most of the existing legacy systems did not keep the design and highly increased the code complexity with more patching of the original codes. To solve this problem, we adopt a code visualization technique which is important to reduce the code complexity among modules. To do this, we suggest a tool chaining method based on the existing open source software tools, which extends NIPA's Software Visualization techniques applied to procedural languages. In addition, it should be refactored to fix bad couplings of the quality measurement indicators within the code visualization. As a result, we can apply reverse engineering to the legacy code, that is, from programming via model to architecture, and then make high quality software with this approach.

• Journal of Korean Society of Transportation
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• v.24 no.2 s.88
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• pp.139-145
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• 2006

This paper develops pedestrian fatality models capable of producing the probability of pedestrian fatality in collision between vehicles and pedestrians. Probabilistic neural network (PNN) and binary logistic regression (BLR) ave employed in modeling pedestrian fatality pedestrian age, vehicle type, and collision speed obtained from reconstructing collected accidents are used as independent variables in fatality models. One of the nice features of this study is that an iterative sampling technique is used to construct various training and test datasets for the purpose of better performance comparison Statistical comparison considering the variation of model Performances is conducted. The results show that the PNN-based fatality model outperforms the BLR-based model. The models developed in this study that allow us to predict the pedestrian fatality would be useful tools for supporting the derivation of various safety Policies and technologies to enhance Pedestrian safety.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.8
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• pp.631-640
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• 2020

Currently, aircraft simulator has drawn a great attention because it has significant advantages of economic, temporal, and spatial costs compared with pilot training with real aircraft. Among the components of the aircraft simulator, flight dynamic model plays a key role in simulating the flight of an actual aircraft. Hence, it is important to verify the fidelity of flight dynamic model with an automated tool. In this paper, we develop a software to automatically verify the fidelity of the flight mechanics model for the efficient development of the aircraft simulator. After designing the software structure and GUI based on the requirements derived from the fidelity verification process, the software is implemented with C # language in Window-based environment. Experimental results on CTSW models show that the developed software is effective in terms of function, performance and user convenience.

• Journal of Broadcast Engineering
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• v.22 no.1
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• pp.78-86
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• 2017

The Internet of Things can offer disabled people the assistance and support, which is essential to achieve a good quality of life. The visually impaired people need assistance in finding locations, detecting obstacles on the way, and getting directions while moving around to reach their destination. Based on this persistent need, this paper proposes a navigation system for blind people using Internet of Things. The technologies used in our proposed system are: a smart cane containing an RFID reader and an ultrasonic sensor, a smart phone and Internet. The sensed data from the ultrasonic sensor for detecting obstacle is converted to International Standard format from ISO/IEC 23005-5 (MPEG-V Part 5). The system detects the blind person's location using the RFID tags implemented on the way. The system uses voice message in the smart phone to communicate with the blind person to lead him to his destination. The proposed system has been tested to navigate successfully in the campus.