• KIPS Transactions on Computer and Communication Systems
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• v.11 no.1
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• pp.23-34
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• 2022

With the development of network technology, the application area has also been diversified, and protocols for various purposes have been developed and the amount of traffic has exploded. Therefore, it is difficult for the network administrator to meet the stability and security standards of the network with the existing traditional switching and routing methods. Software Defined Networking (SDN) is a new networking paradigm proposed to solve this problem. SDN enables efficient network management by programming network operations. This has the advantage that network administrators can flexibly respond to various types of attacks. In this paper, we design a threat level management module, an attack detection module, a packet statistics module, and a flow rule generator that collects attack information through the controller and switch, which are components of SDN, and detects attacks based on these attributes of SDN. It proposes a method to block denial of service attacks (DoS) of advanced attackers by programming and applying honeypot. In the proposed system, the attack packet can be quickly delivered to the honeypot according to the modifiable flow rule, and the honeypot that received the attack packets analyzed the intelligent attack pattern based on this. According to the analysis results, the attack detection module and the threat level management module are adjusted to respond to intelligent attacks. The performance and feasibility of the proposed system was shown by actually implementing the proposed system, performing intelligent attacks with various attack patterns and attack levels, and checking the attack detection rate compared to the existing system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.5
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• pp.619-633
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• 1993

A new High level hardware Description Language, ASPHODEL(Algorithm Synthesis Pascal Hardware for Optimal Design and Efficient Language), and its algorithm compiler for high level synthesis are described in this paper. The new HDL, appropriated to the description of algorithmic level and lower, models VLSI circuits as an abstracted block which is consisted of input/output ports and hierachical processors to control VLSI complexities with efficiency. Also, in order to improve the descriptive power, popular Pascal programming language is modified to build ASPHODEL syntax rules. ASPHODEL algorithm compiler generates an intermediate form through lexical and syntax analysis from ASPHODEL source codes. To show the validation of presented language and its compiler, those are applied to practical design examples.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.10
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• pp.46-53
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• 2011

This paper presents an equalizer reducing CCI(cell-to-cell interference) in MLC NAND flash memory. The CCI is a critical factor which affects occurring data errors in a cell, when surrounding cells are programed. We derived a characteristic equation for CCI considering write procedure of data that is similar with signal equalizing. The model considers the floating gate capacitance coupling effect, the direct field effect, and programming methods of the MLC NAND flash memory. We verify the proposed equalizer comparing with the measured data of 1-block MLC NAND flash memory. As the simulation result, the equalizer shows an error correction ratio about 60% under 20nm NAND process.

• Journal of the Korean School Mathematics Society
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• v.22 no.3
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• pp.257-275
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• 2019

Technology-based convergence education is being emphasized for students in the era of the fourth industrial revolution. In math education, students need to increase their capabilities in the future by having them experience mathematical problems using robots and sensors, a key technology in the era of the fourth industrial revolution. To this end, it is necessary to present educational uses for educational robots in relation to math and curriculum from a 'mathematics education perspective' and analyze its educational use in relation to the mathematics and curriculum, considering the role of mathematics at the base of the process of exploring real-world phenomena and solving problems. Based on the analysis of Van Hiele levels of development in geometry and the LOGO activity level of Olson et al.(1987), this study analyzed and presented the level of LEGO Mindstorm activity, a representative educational Robot capable of collecting and analyzing data and programming in the form of block language, in the first to fourth level.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.2
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• pp.1005-1018
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• 2017

This paper proposes an App Visualization (AppV) based on IoT Self-diagnosis Micro Control Unit (ISMCU) for accident prevention. It collects a current status of a vehicle through a sensor, visualizes it on a smart phone and prevents vehicles from accident. The AppV consists of 5 components. First, a Sensor Layer (SL) judges noxious gas from a current vehicle and a driver's driving habit by collecting data from various sensors such as an Accelerator Position Sensor, an O2 sensor, an Oil Pressure Sensor, etc. and computing the concentration of the CO collected by a semiconductor gas sensor. Second, a Wireless Sensor Communication Layer (WSCL) supports Zigbee, Wi-Fi, and Bluetooth protocol so that it may transfer the sensor data collected in the SL to ISMCU and the data in the ISMCU to a Mobile. Third, an ISMCU integrates the transferred sensor information and transfers the integrated result to a Mobile. Fourth, a Mobile App Block Programming Tool (MABPT) is an independent App generation tool that changes to visual data just the vehicle information which drivers want from a smart phone. Fifth, an Embedded Module (EM) records the data collected through a Smart Phone real time in a Cloud Server. Therefore, because the AppV checks a vehicle' fault and bad driving habits that are not known from sensors and performs self-diagnosis through a mobile, it can reduce time and cost spending on accidents caused by a vehicle's fault and noxious gas emitted to the outside.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.11
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• pp.3876-3895
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• 2014

Recently, Heterogeneous Network (HetNet) with Coordinated Multi-Point (CoMP) scheme is introduced into Long Term Evolution-Advanced (LTE-A) systems to improve digital services for User Equipments (UEs), especially for cell-edge UEs. However, Radio Resource Management (RRM), including Resource Block (RB) scheduling and Power Allocation (PA), in this scenario becomes challenging, due to the intercell cooperation. In this paper, we investigate the RRM problem for downlink transmission of HetNet system with Joint Processing (JP) CoMP (both joint transmission and dynamic cell selection schemes), aiming at maximizing weighted sum data rate under the constraints of both transmission power and backhaul capacity. First, joint RB scheduling and PA problem is formulated as a constrained Mixed Integer Programming (MIP) which is NP-hard. To simplify the formulation problem, we decompose it into two problems of RB scheduling and PA. For RB scheduling, we propose an algorithm with less computational complexity to achieve a suboptimal solution. Then, according to the obtained scheduling results, we present an iterative Karush-Kuhn-Tucker (KKT) method to solve the PA problem. Extensive simulations are conducted to verify the effectiveness and efficiency of the proposed algorithms. Two kinds of JP CoMP schemes are compared with a non-CoMP greedy scheme (max capacity scheme). Simulation results prove that the CoMP schemes with the proposed RRM algorithms dramatically enhance data rate of cell-edge UEs, thereby improving UEs' fairness of data rate. Also, it is shown that the proposed PA algorithms can decrease power consumption of transmission antennas without loss of transmission performance.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.9
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• pp.81-92
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• 1998

A new hybrid technique using several sub-populations having completely different evolutionary behaviors is proposed to increase the possibility to quickly find the global optimum of continuous optimization problem. It has three sub-populations. Two NPOSA algorithms showing good performance in the problem having a rugged fitness function are applied to two sub-populations and a self-adaptive evolutionary algorithm to the other sub-population. Sub-populations evolve in different manners and the interaction among these sub-populations lead to the global optimum quickly. The efficiency of this technique is verified through benchmark test functions. Finally, the algorithm with three sub-populations has been applied to seek for the optimal camera calibration parameters. After an error function has been defined using measured feature points of a calibration block, it has been shown that the algorithm searches for the camera parameters that minimize the error function.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.2
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• pp.345-352
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• 2017

In this paper, we design and implement an educational robot system that can use scratch education with the function of user demanding to perform robot education in actual school site in an embedded environment. It is developed to enable physical education for sensing information processing, software design and programming practice training that is the basis of robotic system. The development environment of the system is Arduino Uno based product using Atmega 328 core, debugging environment based on Arduino Sketch, firmware development language using C language, OS using Windows, Linux, Mac OS X. The system operation process receives the control command of the server using the Bluetooth communication, and drives various sensors of the educational robot. The curriculum includes Scratch program and Bluetooth communication, which enables real-time scratch training. It also provides smartphone apps and is designed to enable education like C and Python through expansion. Teachers at the school site used the developed products and presented performance processing results satisfying the missionary needs of the missionaries.

• Journal of Navigation and Port Research
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• v.36 no.8
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• pp.665-671
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• 2012

A remarshalling is studied as an important operational strategy in an automated container terminal to enhance the productivity of container handling. This means the rearrangements of the containers scattered at a vertical yard block. The dispatching problem for remarshalling is selecting the remarshalling operation considering the available operation time and deciding the operation sequencing to maximize the effectiveness of remarshalling. This study develops the optimal mathematical model for yard crane dispatching problem with mixed integer program and explains dispatching problem using an example. However it is difficult to apply this model to a field problem because of its computational time. Therefore, we compare the representative 5 dispatching rules for real world adaption. In a numerical experiment, maximum weight ratio(MR) rule shows an overall outstanding performance.

• The KIPS Transactions:PartD
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• v.11D no.2
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• pp.415-422
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• 2004

Automation systems improve the productivity of works which relate to product design, facilities management, fault processing and quality evaluation. In these systems, the description language for monitoring and control process is called new control language. These are five flow control languages : IL, ST, FBD, SFC and LD. IL and ST are based on left form. FBD, SFC and LD are based on graphic form. Generally, a software which monitors and controls a system is allowed to use just one flow control language. It is impossible to use more than two languages for simulation in the same system environment. In this paper, we analyzed the characteristics of flow control languages and the process of programming in the legacy system. In addition, for the Integrated processing of languages, we propose Extended ST based on the high-level ST language. Based on this research, we implement a graphical language editor and EST-IL convertor. The graphical language editor makes sequence rules, and converts graphical language into EST. EST-IL convertor has a function to convert EST into IL which is similar to assembly language. As the result of this paper, we present a scheme which integrates all the flow control language processing based on IL.