• The Journal of the Korea institute of electronic communication sciences
• /
• v.13 no.3
• /
• pp.561-570
• /
• 2018

Artificial Intelligence is one of the technologies that are being discussed in the Fourth Industrial Revolution, attracting the attention from companies around the world and this technology is being applied to various industries such as education, finance, automobile, etc. AI integrated ChatBot is a system designed to respond to user questions according to defined response rules. This system is gradually expanded from simple inquiry responses for intelligent virtual assistant service, weather, traffic, schedule, etc. to service provisions through user pattern analysis, to solidify its position as a life-style service. As a result, research on AI integrated ChatBot platform has become necessary. Therefore, this study suggests the design and implementation of an intelligent chatbot service platform for small businesses.

• The KIPS Transactions:PartA
• /
• v.14A no.2
• /
• pp.99-106
• /
• 2007

Grid computing, a mechanism which uses heterogeneous systems that are geographically distributed, draws attention as a new paradigm for the next generation operation of parallel and distributed computing. The importance of grid computing concerning communication cost is very huge because grid computing furnishes uses with integrated virtual computing service, in which a number of computer systems are connected by a high-speed network. Therefore, to reduce the execution time, the scheduling algorithm in grid environment should take communication cost into consideration as well as computing ability of resources. However, most scheduling algorithms have not only ignored the communication cost by assuming that all tasks were dealt in one cluster, but also did not consider the overhead of communication cost when the tasks were processed in a number of clusters. In this paper, the functions of original scheduling algorithms are analyzed. More importantly, the functions of algorithms are compared and analyzed with consideration of communication cost within the co allocation environment, in which a task is performed separately in many clusters.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.9
• /
• pp.3876-3881
• /
• 2012

In typical master/slave teleoperation systems, a human operator generally manipulates the master to control the slave through the visual information like camera image. However, the operator may get into trouble due to the limited visual information depending on the camera positions and the delay on the visual information because of low communication bandwidth. To cope with this inherit problem in the camera-based teleoperation system, this paper presents a teleoperation system using a reconstructed graphic model instead of the camera image. The proposed teleoperation system consists of a robot control module, a master module using a force-reflective joystick, and a graphic user interface (GUI) module. The graphic user interface module provides the operator with a 3D model reconstructed using a small set of sensing data received from the remote site. The proposed teleoperation system is evaluated through a peg-in-hole assembly task.

• Journal of the Korean Society of Physical Medicine
• /
• v.7 no.1
• /
• pp.87-94
• /
• 2012

Purpose : The purpose of this study was to examine the feasibility and efficiency of balance training program through an interactive video game regimen in people with chronic stroke. Methods : Thirty patients with chronic hemiparetic stroke were recruited. Participants were randomly assigned to either a control group (n=15) or an experimental group (n=15). The control group received the general physical therapy including of strengthening and balance exercise five times a week whereas the experimental group received a program of balance exercise with video game play based on virtual reality as well as the same typical physical therapy. The experimental group received 6 sessions for four weeks. Each session was given 5 minutes. An interactive computer game exercise regimen lasted 30 minutes without rest periods. Outcome measures for weight transfer to paretic side, non-paretic side and sit-squat-speed, sit-squat-length, sit-to-standspeed and sit-to-stand-area for the control group (n=15) and experimental group (n=15) before and after treatment were obtained by using the biorescure. Results: Outcomes demonstrated significant improvement in the experimental group compared with the control group in weight transfer to paretic side, non-paretic side and sit-squat-speed, sit-squat-length, sit-to-stand-speed. No significant training effect was showed in sit-to-stand-area between pretraining and post-training. Conclusion : An interactive computer game exercise based on task oriented approach for balance in chronic stroke were feasible. In other words, This regimen resulted in a greater improvement in dynamic balance for people with chronic stroke.

• International Journal of Contents
• /
• v.13 no.2
• /
• pp.29-34
• /
• 2017

Cloud computing is becoming an effective and efficient way of computing resources and computing service integration. Through centralized management of resources and services, cloud computing delivers hosted services over the internet, such that access to shared hardware, software, applications, information, and all resources is elastically provided to the consumer on-demand. The main enabling technology for cloud computing is virtualization. Virtualization software creates a temporarily simulated or extended version of computing and network resources. The objectives of virtualization are as follows: first, to fully utilize the shared resources by applying partitioning and time-sharing; second, to centralize resource management; third, to enhance cloud data center agility and provide the required scalability and elasticity for on-demand capabilities; fourth, to improve testing and running software diagnostics on different operating platforms; and fifth, to improve the portability of applications and workload migration capabilities. One of the key features of cloud computing is elasticity. It enables users to create and remove virtual computing resources dynamically according to the changing demand, but it is not easy to make a decision regarding the right amount of resources. Indeed, proper provisioning of the resources to applications is an important issue in IaaS cloud computing. Most web applications encounter large and fluctuating task requests. In predictable situations, the resources can be provisioned in advance through capacity planning techniques. But in case of unplanned and spike requests, it would be desirable to automatically scale the resources, called auto-scaling, which adjusts the resources allocated to applications based on its need at any given time. This would free the user from the burden of deciding how many resources are necessary each time. In this work, we propose an analytical and efficient VM-level scaling scheme by modeling each VM in a data center as an M/M/1 processor sharing queue. Our proposed VM-level scaling scheme is validated via a numerical experiment.

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.8
• /
• pp.875-881
• /
• 2014

The redundancy resolution of the seven DOF (Degree of Freedom) upper limb exoskeleton is key to the synchronous motion between a robot and a human user. According to the seven DOF human arm model, positioning and orientating the wrist can be completed by multiple arm configurations that results in the non-unique solution to the inverse kinematics. This paper presents analysis on the kinematic and dynamic aspect of the human arm movement and its effect on the redundancy resolution of the seven DOF human arm model. The redundancy of the arm is expressed mathematically by defining the swivel angle. The final form of swivel angle can be represented as a linear combination of two different swivel angles achieved by optimizing two cost functions based on kinematic and dynamic criteria. The kinematic criterion is to maximize the projection of the longest principal axis of the manipulability ellipsoid of the human arm on the vector connecting the wrist and the virtual target on the head region. The dynamic criterion is to minimize the mechanical work done in the joint space for each of two consecutive points along the task space trajectory. The contribution of each criterion on the redundancy was verified by the post processing of experimental data collected with a motion capture system. Results indicate that the bimodal redundancy resolution approach improved the accuracy of the predicted swivel angle. Statistical testing of the dynamic constraint contribution shows that under moderate speeds and no load, the dynamic component of the human arm is not dominant, and it is enough to resolve the redundancy without dynamic constraint for the realtime application.

• 한국HCI학회:학술대회논문집
• /
• 2008.02b
• /
• pp.251-256
• /
• 2008

가상 채널을 통한 IPTV 인터렉션 디자인 -멀티미디어 컨텐트 소비를 중심으로 정해진 방송시간에 따라 일 방향적으로 프로그램 매제를 제공하던 TV 는 바야흐로 혁명의 시대를 맞고 있다. 이에 따라 사용자는 오랜 시간 기존의 TV 에서의 사용자 경험을 유지한 채, IPTV 라는 새로운 방식의 시스템을 경험하게 된다. 따라서 기존의 TV 사용자들도 이러한 새로운 형태의 TV를 거부감 없이 적극적으로 사용할 수 있도록 하기 위하여 사용자 중심의 인터렉션에 대한 연구와 인터페이스 개발의 필요성이 높아지고 있다. 본 연구에서는 현재 국내에 상용화된 IPTV 의 서비스들 중에서 주식, 쇼핑, 교통 등과 같은 양방향 서비스를 제외한 실시간 방송과 기존의 VOD 컨텐츠들을 포함한 멀티미디어 컨텐츠 소비에 대한 인터렉션 방법을 연구 범위로 정하였다. 본 연구를 위하여, 기존의 IPTV VOD 컨텐트의 소비 방식에 대해 다양한 사용자 리서치를 실시하였다. 그 결과 피 실험자들은 기존의 TV 에서 경험했던 것과 같이 단순하고 심플한 조작 방식으로 원하는 task 를 수행하여 각 목적에 맞는 결과를 얻는 것을 기대 한다는 것을 알 수 있었다. 그러나 실제 이 과정에서 피실험자들은 인터렉션 상의 여러 가지 문제점을 겪었는데, 특히 VOD 소비 방법의 accessibility 부분에서 해결해야 할 사용자 경험 요소들을 많음을 알 수 있었다. 따라서 본 연구를 통하여 현재 국내에 상용화된 IPTV 의 VOD 컨텐츠 소비 방식과 실시간 방송 컨텐츠를 소비함에 있어서 사용자가 만족하지 못하는 경험적 요소들을 집중적으로 연구하여, 기존의 TV 사용자가 더욱 적극적으로 멀티미디어 컨텐츠를 소비할 수 있는 방안으로 새로운 개념의 가상채널 인터렉션 방법을 제안하고자 한다.

• KIISE Transactions on Computing Practices
• /
• v.22 no.9
• /
• pp.419-425
• /
• 2016

In navigator systems, keeping map data up-to-date is an important task. Manual update involves a substantial cost and it is difficult to achieve immediate reflection of changes with manual updates. In this paper, we present a method for trajectory-center extraction, which is essential for automatic road map generation with GPS data. Though clustered trajectories are necessary to extract the center road, real trajectories are not clustered. To address this problem, this paper proposes a new method using the maximum overlapping interval and trajectory clustering. Finally, we apply the Virtual Running method to extract the center road from the clustered trajectories. We conducted experiments on real massive taxi GPS data sets collected throughout Gang-Nam-Gu, Sung-Nam city and all parts of Seoul city. Experimental results showed that our method is stable and efficient for extracting the center trajectory of real roads.

• Journal of Communications and Networks
• /
• v.16 no.5
• /
• pp.548-558
• /
• 2014

Load distribution is vital to the performance of multipath transport. The task becomes more challenging in real-time multimedia applications (RTMA), which impose stringent delay requirements. Two key issues to be addressed are: 1) How to minimize end-to-end delay and 2) how to alleviate packet reordering that incurs additional recovery time at the receiver. In this paper, we propose sub-packet based multipath load distribution (SPMLD), a new model that splits traffic at the granularity of sub-packet. Our SPMLD model aims to minimize total packet delay by effectively aggregating multiple parallel paths as a single virtual path. First, we formulate the packet splitting over multiple paths as a constrained optimization problem and derive its solution based on progressive approximation method. Second, in the solution, we analyze queuing delay by introducing D/M/1 model and obtain the expression of dynamic packet splitting ratio for each path. Third, in order to describe SPMLD's scheduling policy, we propose two distributed algorithms respectively implemented in the source and destination nodes. We evaluate the performance of SPMLD through extensive simulations in QualNet using real-time H.264 video streaming. Experimental results demonstrate that: SPMLD outperforms previous flow and packet based load distribution models in terms of video peak signal-to-noise ratio, total packet delay, end-to-end delay, and risk of packet reordering. Besides, SPMLD's extra overhead is tiny compared to the input video streaming.

• Convergence Security Journal
• /
• v.17 no.1
• /
• pp.101-109
• /
• 2017

The Internet of things is a system that connects and communicates all sorts of things such as people, objects, and data. It's to create and share information by its own each other. It can be used to enhance the function of private security and has brought about innovative development of private security. The Internet of things is a system that allows devices connected to the Internet to communicate independently of people-objects, objects-objects connected to the Internet. That and can be used in many industries, especially in the private security sector, its value is high. The use of the Internet of things to private security sector can reinforce security zones with always-on surveillance systems, also be enhanced by its own preparedness and response to the situation. However, this study will discusse the application and development of private security in the Internet of things. The practical application of the virtual space is an immediate task and it is also an essential factor in securing security.