• Journal of the Korea Institute of Information Security & Cryptology
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• 제25권5호
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• pp.1115-1122
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• 2015

In recent years, the use of game bots by illegal programs has been expanded from individual to group scale; this brings about serious problems in online game industry. The gold farmers group creates an in-game social community so-called "guild" to obtain a large amount of game money and manage game bots efficiently. Although game developers detect game bots by detection algorithms, the algorithms can detect only part of the gold farmers group. In this paper, we propose a detection method for the gold farmers group on a basis of normal and bot guilds characteristic analysis. In order to differentiate normal and bots guild, we analyze transaction patterns for individuals, auction house and chatting. With the analyzed results, we can detect game bot guilds. We demonstrate the feasibility of the proposed methods with real datasets from one of the popular online games named AION in Korea.

• Journal of Engineering Education Research
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• 제14권1호
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• pp.74-81
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• 2011

In this paper, the author researched to enhance course outcomes while increasing the interest in engineering design through the 'Introduction to Engineering Design Course'. Deviating from the current practice of engaging in content-oriented lectures, the redesign of the weekly lecture has been conducted with a focus on learning achievement in order to enhance design competency, teamwork and communication skills, which are the goals of the PO3, PO6 and PO7, respectively. Moreover, assessment tools have been developed according to learning achievement, and rubrics, the measurement criteria, have been defined according to the respective assessment tools, along with course goals for learning achievement and results analysis. To enhance course learning achievement, as well as to induce interest in and satisfaction with the 'Introduction to Engineering Design Course', a design project utilizing a Boe-Bot robot has been carried out. An evaluation on learning achievement and lecture has identified an increase in learning achievement and interest in design in comparison with that of previous lectures.

• Journal of the Korea Convergence Society
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• 제11권8호
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• pp.33-38
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• 2020

Modern society needs to think in new directions and solve problems by grafting problems from diverse fields with computers. Abstraction and automation of various problems using computing technology with your own ideas is called computational thinking. In this paper, we analyze how to diagnose and improve knowledge information based on computational thinking through the process of presenting a variety of problems in programming education situations and finding several problem-solving methods to solve them. To pretest the learners, they were diagnosed using a measurement sheet and a LightBot. By determining the correlation between the evaluation results and LightBot results, the learners' current knowledge statuses were checked, and the correlation between the evaluation results and the LightBot results, based on what was taught according to the problem-solving learning technique, was analyzed according to the proposed technique. The analysis of the group average score of the learners showed that the learning effect was significant. If the method of deriving and improving knowledge based on computational thinking ability for solving the problem proposed in this paper is applied to software education, it will induce student interest, thereby increasing the learning effect.

• Journal of the Korea Institute of Information Security & Cryptology
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• 제26권1호
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• pp.93-107
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• 2016

Game bot playing is one of the main risks in Massively Multi-Online Role Playing Games(MMORPG) because it damages overall game playing environment, especially the balance of the in-game economy. There have been many studies to detect game bot. However, the previous detection models require continuous maintenance efforts to train and learn the game bots' patterns whenever the game contents change. In this work, we have proposed a machine learning technique using the self-similarity property that is an intrinsic attribute in game bots and automated maintenance system. We have tested our method and implemented a system to major three commercial games in South Korea. As a result, our proposed system can detect and classify game bots with high accuracy.

• Journal of Institute of Control, Robotics and Systems
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• 제18권5호
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• pp.487-495
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• 2012

In this paper, a Smart Home Service Robot, McBot II, which performs mess-cleanup function etc. in house, is designed much more optimally than other service robots. It is newly developed in much more practical system than McBot I which we had developed two years ago. One characteristic attribute of mobile platforms equipped with a set of dependent wheels is their omni- directionality and the ability to realize complex translational and rotational trajectories for agile navigation in door. An accurate coordination of steering angle and spinning rate of each wheel is necessary for a consistent motion. This paper develops trajectory controller of 3-wheels omni-directional mobile robot using fuzzy azimuth estimator. A specialized anthropomorphic robot manipulator which can be attached to the housemaid robot McBot II, is developed in this paper. This built-in type manipulator consists of both arms with 4 DOF (Degree of Freedom) each and both hands with 3 DOF each. The robotic arm is optimally designed to satisfy both the minimum mechanical size and the maximum workspace. Minimum mass and length are required for the built-in cooperated-arms system. But that makes the workspace so small. This paper proposes optimal design method to overcome the problem by using neck joint to move the arms horizontally forward/backward and waist joint to move them vertically up/down. The robotic hand, which has two fingers and a thumb, is also optimally designed in task-based concept. Finally, the good performance of the developed McBot II is confirmed through live tests of the mess-cleanup task.

• The Journal of the Korea Contents Association
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• 제5권5호
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• pp.172-181
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• 2005

The latest attack type against network traffic appeared by worm and bot that are advanced in DDoS. It is difficult to detect them because they are diversified, intelligent, concealed and automated. The exisiting traffic analysis method using SNMP has a vulnerable problem; it considers normal P2P and other application program to be harmful traffic. It also has limitation that does not analyze advanced programs such as worm and bot to harmful traffic. Therefore, we analyzed harmful traffic out Protocol and Port analysis. We also classified traffic by protocol, well-known port, P2P port, existing attack port, and specification port, apply singularity weight to detect, and analyze attack availability. As a result of simulation, it is proved that it can effectively detect P2P application, worm, bot, and DDoS attack.

• International Journal of Advanced Culture Technology
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• 제7권4호
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• pp.313-320
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• 2019

Nowadays, as the availability of tiny, low-cost microcomputer increases at a high level, mobile robots are experiencing remarkable enhancements in hardware design, software performance, and connectivity advancements. In order to control Turtlebot 2, several algorithms have been developed using the Robot Operating System(ROS). However, ROS requires to be run on a high-cost computer which increases the hardware cost and the power consumption to the robot. Therefore, design an algorithm based on low-cost hardware is the most innovative way to reduce the unnecessary costs of the hardware, to increase the performance, and to decrease the power consumed by the computer on the robot. In this paper, we present a path-finding algorithm for TurtleBot 2 based on low-cost hardware. We implemented the algorithm using Raspberry pi, Windows 10 IoT core, and RPLIDAR A2. Firstly, we used Raspberry pi as the alternative to the computer employed to handle ROS and to control the robot. Raspberry pi has the advantages of reducing the hardware cost and the energy consumed by the computer on the robot. Secondly, using RPLIDAR A2 and Windows 10 IoT core which is running on Raspberry pi, we implemented the path-finding algorithm which allows TurtleBot 2 to navigate from the starting point to the destination using the map of the area. In addition, we used C# and Universal Windows Platform to implement the proposed algorithm.

• The Journal of the Korean dental association
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• 제56권2호
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• pp.94-102
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• 2018

The present study was conducted to assess the growth changes of human chin in childhood and adolescence at various stages of skeletal maturation using metallic implant installed in mandibular body. Lateral cephalographs including 23 subjects (9 males and 14 females) between 7-18 years old were used, which had been taken at University of California in San Francisco and kept at University of the Pacific. Three lateral cephalographs were chosen for each subject according to CVM (Cervical Vertebral Maturation) method (CVM stage 1 to 2, CVM stage 3 to 4, and CVM stage 5 to 6) which assess the extent of the skeletal maturation using the second, third, and fourth cervical vertebrae. V-ceph was used in order to mark the 8 landmarks (S, N, A, B, Pog, Me, Go, Imp) on lateral cephalographs and obtain 8 angular and linear measurements(ANB, SNPog, SN-GoMe, Imp-B, Imp-Pog, B-Pog//GoMe, $GoMe{\bot}B$, $GoMe{\bot}Pog$). Among 8 measurements, ANB, SNPog, SN-GoMe, B-Pog//GoMe, $GoMe{\bot}B$ showed statistically significant growth changes at various stages of skeletal maturation according to CVM method, while there were no significant differences on Imp-B, Imp-Pog, $GoMe{\bot}Pog$. The results suggest that the increasing prominence of human chin is greatly influenced by the vertical growth of B point area, in addition to the change and growth in chin and mandible proper.

• Journal of the Korea Institute of Information Security & Cryptology
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• 제28권6호
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• pp.1415-1425
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• 2018

MMORPG genre is based on the belief that all users in virtual world are equal. All users are able to obtain the corresponding wealth or status as they strive under the same resource, time. However, game bot is the main factor for harming this fair competition, causing benign gamers to feel a relative deprivation and deviate from the game. Game bots mainly form GFG(Gold Farming Group), which collects the goods in the game indiscriminately and adversely affects the economic system of the game. A general game bot detection algorithm is useful for detecting each bot, but it only covers few portions of GFG, not the whole, so it needs a wider range of detecting method. In this paper, we propose a method of detecting GFG based on items used in MMORPG genre. Several items that are mainly traded in the game were selected and the flows of those items were represented by a network. We Identified the characteristics of exchanging items of GFG bots and can identify the GFG's item trade network with real datasets from one of the popular online games.

• Journal of the Korea Institute of Information Security & Cryptology
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• 제19권4호
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• pp.51-61
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• 2009

Recently, the cyber-attacks using botnets are being increased, Because these attacks pursue the money, the criminal aspect is also being increased, There are spreading of spam mail, DDoS(Distributed Denial of Service) attacks, propagations of malicious codes and malwares, phishings. leaks of sensitive informations as cyber-attacks that used botnets. There are many studies about detection and mitigation techniques against centralized botnets, namely IRC and HITP botnets. However, P2P botnets are still in an early stage of their studies. In this paper, we analyzed the traffics of the Peacomm bot that is one of P2P-based storm bot by using honeynet which is utilized in active analysis of network attacks. As a result, we could see that the Peacomm bot sends a large number of UDP packets to the zombies in wide network through P2P. Furthermore, we could know that the Peacomm bot makes the scale of botnet maintained and extended through these results. We expect that these results are used as a basis of detection and mitigation techniques against P2P botnets.