• Proceedings of the Korea Information Processing Society Conference
• /
• 2014.11a
• /
• pp.177-178
• /
• 2014

무선센서네트워크에서 사용되는 혼잡제어 방식은 일반적인 네트워크 방식과는 다르게 고려해야할 사항이 있다. 문제 해결에 사용할수 있는 자원이 한정적이며, 중앙에서 혼잡 제어를 할 경우 지나친 통신 부하가 발생할 수 있다. 본 논문에서는 집단지성(Swarm Intelligence)의 일종인 새 떼의 행동양식을 무선센서네트워크에 적용한 혼잡제어 기법을 살펴보고, 기존 기법에서 발생하는 에너지 소비 불균형을 해결하기 위한 기법에 대해 기술한다. 본 논문을 통해 무선센서네트워크에 새 떼의 간단한 행동양식을 적용함으로써 강인하고 확장 가능하며 자가 적응이 가능한 혼잡제어가 가능함을 확인하고, 집단지성이 우리가 직면하고 있는 다양한 연구 과제의 해결 도구가 될 수 있는 가능성을 보인다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.04b
• /
• pp.550-552
• /
• 2004

가상공간에는 PC(Playerable Character), NPC(Non-Playerable Character)등의 동적 객체와 건물, 지형 등의 정적 객체들이 존재하게 된다. 동적 객체들의 경우, 현실감을 위해 인공지능이 자주 이용된다 현재까지 인공지능에 대한 연구는 유한상태기계(Finite State Machine. FSM). 학습 알고리즘, 유전자 알고리즘, 신경망 알고리즘 등을 중심으로 진행되어 왔다. 이중 유한상태기계는 비교적 알고리즘이 간단하고, 시스템의 부담이 적어 간단한 객체의 인공지능으로 가장 널리 사용되고 있다. 본 논문은 유찬상태기계를 확장하여 모드변경(Mode Change)과 그룹행동을 보여줄 수 있는 XML을 활용한 FSM 시스템을 제안한다. 여기서 모드변경이란 하나의 행동 패턴에서 다른 행동 패턴으로 변경하는 것을, 그룹행동은 여러 객체가 함께 행동하는 Flocking기법을 지칭한파. 이러한 XML을 활용한 FSM 시스템은 다양한 패턴의 정의는 물론, 객체의 상태 정의 및 수정, 확장이 용이하여, 다양한 응용 분야에서 활용될 수 있다.

• Journal of the Korean Mathematical Society
• /
• v.61 no.3
• /
• pp.565-602
• /
• 2024

We study the collective behaviors of two second-order nonlinear consensus models with a bonding force, namely the Kuramoto model and the Cucker-Smale model with inter-particle bonding force. The proposed models contain feedback control terms which induce collision avoidance and emergent consensus dynamics in a suitable framework. Through the cooperative interplays between feedback controls, initial state configuration tends to an ordered configuration asymptotically under suitable frameworks which are formulated in terms of system parameters and initial configurations. For a two-particle system on the real line, we show that the relative state tends to the preassigned value asymptotically, and we also provide several numerical examples to analyze the possible nonlinear dynamics of the proposed models, and compare them with analytical results.

• Journal of the Korea Society for Simulation
• /
• v.20 no.4
• /
• pp.105-114
• /
• 2011

The roadmap-based planning is a path planning method which is used widely for a goal-directed movement in Robotics and has been applied to the world of computer animation such as computer games. However it is unnatural for computer characters to follow the path planned by the roadmap method as it is performed in Robotics. Flocking which is used for realistic and natural movements in computer animation enables character's movement by using a few simple rules without planning unlike the roadmap method. However it is impossible to achieve a goal-directed movement with flocking only because it does not keep states. In this paper we propose a simulation method which combines planning based on the road map with reactive actions for natural movements along the path planned. We define and implement steering behaviors for a leader which are needed to follow the trajectory naturally by analysing characteristics of roadmap-based paths and for the rest of members which follow the leader in various manners by detecting obstacles. The simulations are performed and demonstrated by using the implemented steering behaviors on every possible combination of roadmap-based path planning methods and models of configuration spaces. We also show that the detection of obstacle-collisions can be done effectively because paths are planned in the configuration space in which a moving object is reduced to a point.

• Macromolecular Research
• /
• v.8 no.1
• /
• pp.6-11
• /
• 2000

In this study, we examined the charging behavior of chopped carbon fibers during electro-flocking process, which is one of the key processes of the novel technique for fabricating conductive polymer composite films. Short carbon fibers (CF) during electroflocking were electrically charged by the combined effect of contact charging, corona charging and tribocharging. The specific charge built on CF surface was measured by using Faraday cup method. Specific charge increased not only with increasing electric field strength and potential impressed to mesh electrode as expected from theoretical considerations in literature, but with decreasing mesh opening size due to the improved contact charging condition. However, CF length was found unexpectedly to influence the amount of CF specific charge due to the agglomerated nature of CF flocks leading to the change in charging conditions.

• Korean Journal of Ichthyology
• /
• v.27 no.2
• /
• pp.153-158
• /
• 2015

Five specimens of Lethotremus awae (Cyclopteridae) were collected from the northern coastal waters of Jeju Island, Korea, during a survey on larval and juvenile fishes flocking to aquatic lamp in 2004 ~ 2007. They were characterized by having a spherical body with three barbel-like tubes on head and the first dorsal fin overgrown by skin with undiscernible rays as well as VIII-9 dorsal fin rays, 8 ~ 9 anal fin rays and 22 ~ 23 pectoral fin rays. A new Korean name, "Eom-ji-do-chi", was proposed for the species.

• Journal of Fashion Business
• /
• v.9 no.1
• /
• pp.1-20
• /
• 2005

This study is purposed to provide new idea for developing high value added fashion goods by studying relief effects of fashion design. Based on prior researches, various ways to give relief effects were searched and then modern fashion design cases were looked for which were referred to fashion-related magazines and collection-related internet sites since the late 1990s. The ways for relief effects are weaving, industrial finishing, sewing technique. Weaving techniques are about fancy yarns, variation of weaving structure, pile weave. Industrial finishing techniques which can make relief effects are embossing, heat-setting, shearing, pliss, burn out, flocking. Sewing techniques are quilting, pleats, embroidery, slash, attachment in accordance with the way to produce relief effects. The forms of relief effects are tactile pattern that cannot be seen in the distance, subtle relief pattern which is more three-dimensional than tactile pattern, rhythmical relief pattern, sculptural pattern, and deep-volumed pattern. The present research can provide practical data for design by studying techniques of relief effects and collecting and arranging design cases that have been sporadically carried out. The study on relief and unique surface effects can be a way to effectively stimulate and express emotions of modern people with various taste and individuality.

• Journal of Korea Game Society
• /
• v.13 no.3
• /
• pp.47-54
• /
• 2013

In general, algorithms to find continuous k-nearest neighbors has been researched on the location based services monitoring periodically the moving objects such as vehicles and mobile phone. Those researches assume the environment that the number of query points is much less than that of moving objects and the query points are not moved but fixed. In gaming environments, cases to find k-nearest neighbors are when computing the next movement considering the neighbors such as flocking, crowd and robot simulations. Thus, every moving object becomes a query point so that the number of query point is same to that of moving objects and the query points are also moving. In this paper, we analyze the performance of the existing algorithms focused on location based services how they operate under the gaming environments.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.48 no.8
• /
• pp.573-580
• /
• 2020

One of challengeable problems of multi-agent systems is a positioning control. Augmented Cucker-Smale model is using for controlling position and velocity of the multi-agent system. The original model applies same coefficients to all agents in same group, so that does not consider characteristic of each agent. To enhance performance of the original model, this paper transforms original coefficients to Mahalanobis distance coefficients that reflects an initial distribution of multi-agent systems and applies statistical degrees of freedom. This paper not only confirms tendency of enhanced performance of the suggested model by using monte-carlo simulation, but also additionally compares trajectory of the original model with the suggested model to confirm coefficients of Mahalanobis distance performing correctly.

• Journal of Korea Multimedia Society
• /
• v.6 no.2
• /
• pp.332-339
• /
• 2003

To solve the large scale optimization problem approximately, various approaches have been introduced. Recently the Particle Swarm Optimization has been introduced. The Particle Swarm Optimization simulates the process of birds flocking or fish schooling for food, as with the information of each agent is skated by other agents. The Particle Swarm Optimization technique has been applied to various optimization problems whose variables are continuous. However, there are seldom trials for visualization of searching process. This paper proposes a new visualization tool for searching process of Particle Swarm Optimization algorithm. The proposed tool is effective for understanding the searching process of Particle Swarm Optimization method and educational for students. The computational results can be shown tiny and very helpful for education.