• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.5 s.305
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• pp.1-12
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• 2005

A Mobile manipulator - a serial connection of a mobile robot and a task robot - is a very useful system to achieve various tasks in dangerous environment. because it has the higher performance than a fixed base manipulator in regard to the size of it's operational workspace. Unfortunately the use of a mobile robot introduces non-holonomic constraints, and the combination of a mobile robot and a manipulator generally introduces kinematic redundancy. In this paper, first a method for estimating the position of object at the cartesian coordinate system acquired by using the geometrical relationship between the image captured by 2-DOF active camera mounted on mobile robot and real object is proposed. Second, we propose a method to determine a optimal path between current the position of mobile manipulator whose mobile robot is non-holonomic and the position of object estimated by image information through the global displacement of the system in a symbolic way, using homogenous matrices. Then, we compute the corresponding joint parameters to make the desired displacement coincide with the computed symbolic displacement and object is captured through the control of a manipulator. The effectiveness of proposed method is demonstrated by the simulation and real experiment using the mobile manipulator.

• Journal of KIISE:Software and Applications
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• v.37 no.5
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• pp.363-369
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• 2010

Demonstration-based learning has the advantage that a user can easily teach his/her robot new task knowledge just by demonstrating directly how to perform the task. However, many previous demonstration-based learning techniques used a kind of attribute-value vector model to represent their state spaces and policies. Due to the limitation of this model, they suffered from both low efficiency of the learning process and low reusability of the learned policy. In this paper, we present a new demonstration-based learning method, in which the relational model is adopted in place of the attribute-value model. Applying the relational instance-based learning to the training examples extracted from the records of the user demonstrations, the method derives a relational instance-based policy which can be easily utilized for other similar tasks in the same domain. A relational policy maps a context, represented as a pair of (state, goal), to a corresponding action to be executed. In this paper, we give a detail explanation of our demonstration-based relational policy learning method, and then analyze the effectiveness of our learning method through some experiments using a robot simulator.

• Journal of the Korea Society of Computer and Information
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• v.19 no.12
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• pp.1-10
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• 2014

This paper proposes a scheduling scheme that enhances power consumption efficiency of periodic real-time tasks using DVFS and power-shut-down mechanisms while meeting their deadlines on multicore processors. The proposed scheme is suitable for dependent multicore processors in which processing cores have an identical speed at an instant, and resolves the load unbalance of processing cores by exploiting parallel processing because the load unbalance causes inefficient power consumption in previous methods. Also the scheme activates a part of processing cores and turns off the power of unused cores. The number of activated processing cores is determined through mathematical analysis. Evaluation experiments show that the proposed scheme saves up to 77% power consumption of the previous method.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2551-2562
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• 2013

Since 2006, an Intelligent Excavation Robot which automatically performs the earth-work without operator has been developed in Korea. The technologies for automatically recognizing the terrain of work environment and detecting the objects such as obstacles or dump trucks are essential for its work quality and safety. In several countries, terrestrial 3D laser scanner and stereo vision camera have been used to model the local area around workspace of the automated construction equipment. However, these attempts have some problems that require high cost to make the sensor system or long processing time to eliminate the noise from 3D model outcome. The objectives of this study are to analyze the advantages of the existing 3D modeling sensors and to examine the applicability for practical use by using Analytic Hierarchical Process(AHP). In this study, 3D modeling quality and accuracy of modeling sensors were tested at the real earth-work environment.

• Horticultural Science & Technology
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• v.30 no.4
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• pp.449-462
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• 2012

The objectives of this study were to measure the range of motion for joints and muscle activation of upper limb for flower arrangement tasks for physical rehabilitation and to test horticultural therapy programs using flower arrangement tasks for improving upper limb function of the patients with stroke. Major flower arrangement tasks were classified with eight tasks (cutting 1, thick stem; cutting 2, thin stem; fixing 1, long stem; fixing 2, short stem; rolling a leaf; bending 1, thick stem; bending 2, thin stem; and winding, using a wire) based on the occupational analysis. When eight male university students (mean age $24.1{\pm}2.5$ years) conducted the eight flower arrangement tasks, range of motion for joints and muscle activation of upper limb were measured by a 3D motion analyzer and electromyography, respectively. Based on the results of the range of motion and muscle activation of upper limb, horticultural therapy programs using flower arrangement tasks (total 33 sessions) for improving upper limb function of the patients with stroke was conducted at a rehabilitation hospital, Seoul, South Korea and then the range of motion, grip strength, and upper limb function of the patients were tested. Among the eight flower arrangement tasks, cutting 1, winding, and bending 1 induced the highest value for the range of motion in joints of shoulder, elbow, and wrist, respectively (P < 0.001). In terms of muscle activation, eight flower arrangement tasks performed in this study showed various patterns of muscle activation and several muscles were simultaneously used for each task (P < 0.001). In addition, thickness and length of the materials used in a task had a prominent effect on the range of motion for joints and muscle activation of upper limb (P < 0.001). The stroke patients had positive effects for their range of motion of upper limb (shoulder, forearm, and elbow), grip strength, and overall upper limb function through the horticultural therapy program. Thus, this study suggested that flower arrangement tasks would be a potential horticultural activity for physical rehabilitation program. It would be interesting to apply a customized horticultural therapy program using flower arrangement tasks according to the symptoms of patient for physical rehabilitation.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.9 no.10
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• pp.797-808
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• 2019

In a closed workplace, the management of the workplace is important because the environmental data at the workplace has a great influence on the safety of workers. Today's industrial sites are transformed into data-based factories that collect and analyze data through sensors in those sites, requiring a management system to ensure safety. In general, a safety management system stores and manages data on a central server associated with a database. Since such management system introduces high possibility of forgery and loss of data, workers often suspect the reliability of the information on the management system. In this paper, we present a worker safety management system based on the EOS blockchain which is considered as third-generation blockchain technology. The developed system consists of a set of smart contracts on the EOS blockchain and 3 decentralized applications associated with the blockchain. According to the roles of users, the worker and manager applications respectively perform the process of initiating or terminating tasks as blockchain transactions. The entire transaction history is distributed and stored in all nodes participating in the blockchain network, so forgery and loss of data is practically impossible. The system administrator application assigns the account rights of workers and managers appropriate for performing the functions, and specifies the safety standards of IoT data for ensuring workplace safety. The IoT data received from sensor platforms in workplaces and the information on initiation, termination or approval of tasks assigned to workers, are explicitly stored and managed in the EOS smart contracts.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.2
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• pp.114-123
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• 2009

Context-aware systems are reactive computing systems, aware of external context. Considering various sensors and actuators connected, application programming on top of such systems is known to be much more complex than in contentional ones. This paper suggests a formal framework for context-aware systems, by extracting their common properties. That makes a useful birds-eye view for the behaviors of a whole complex system, as a base for a convenient developing environment and systematic analysis. In this framework, reactive-ness is handled by event-condition-action rules and global state-transitions, which are essential in a lot of context-aware applications. In addition, behaviors of each elementary device are modelled with its own state-transitions, and tightly bound to the entire task.

• Spatial Information Research
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• v.11 no.1
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• pp.41-60
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• 2003

It is noted that the paper mapping system for University Building Facility has many limitations in terms of data maintenance, real-time GIS data acquisition, and economic efficiency. The aim of this research was to evaluate an operational potential of an on site real-time mobile GIS technique to resolve the problem faced in the university. The idea is based upon the recent trends in the field of 'Telecommunication and Information Technology' that uses a PDA (personal Digital Assistants), wireless network computing, mobile computing, etc. A real time mobile GIS approach has been adopted, in which a PDA is linked to a wireless internet and field workers record data on the computer at the site and analyse data on site. While there should be a considerable number and variety of factors associated with real-time mobile GIS quality, this research focuses on three criteria that are identified as fundamental to customer requirements; (1) data quarry (2) spatial analysis (3) real-time GIS database building. 'Art--empirical study for a case study facility has been conducted to confirm the validity for the system. The system has been checked experimentally, enabled the field users to quarry the data required simply and execute spatial analysis (buffer, overlay etc.,) accommodating versatile alternatives on the site. Detailed visual maps can be generated over large areas quickly and easily. The PDA interface, in particular, were ideally suited for field users to interactively displaying positional information with attribute data. This system has shown to be quite convenient to maintaining a highly reliable database since it could playa crucial role in documenting at real-time basis temporal and spatial changes occurred in the facilities. It is anticipated that this research output will greatly serve to introduce the reliable and cost-effective facility mapping system in the university by overcoming serious constraints suffered from the past non-real time mobile GIS approach.

• Electronics and Telecommunications Trends
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• v.29 no.5
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• pp.125-135
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• 2014

ICN(Information Centric Networking)은 데이터가 저장되어 있는 위치(where) 중심으로 동작하고 있는 현재의 인터넷 패러다임을 사용자의 최종 관심사인 데이터(what) 중심으로 이동하고자 하는 새로운 네트워킹 구조이다. 이 패러다임은 최근 들어 대두된 것은 아니며 이미 2000년대 초반부터 이러한 개념을 도입한 실험적 프로젝트들이 있어 왔다. 이러한 다양한 연구과제들은 세부적인 기술측면에서는 다소 차이가 있지만, 지향하는 목표 측면에서는 유사한 개념이라고 볼 수 있다. 하지만 데이터 중심 인터넷 구조에 대한 관심이 높아지면서 개별적 기술들을 아우르는 기술표준화에 대한 관심이 높아졌는데, 인터넷 선행기술을 연구하는 인터넷 연구 그룹(IRTF: Internet Research Task Force)에서는 이러한 표준화 요구를 수용하여 ICNRG(ICN Research Group)라는 연구그룹을 결성하고 2012년부터 관련 기술의 선행기술 표준연구를 시작하였다. 본고에서는 ICNRG에서 작업 중인 표준문서를 기반으로 이러한 ICN 기술에서의 연구과제를 검토해보고 ICN 기술을 검증/평가하기 위한 검증 시나리오에 대해서도 정리해 보고자 한다.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2001.05a
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• pp.200-203
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• 2001

감성평가 실험시 피험자가 받는 작업부하의 영향을 실시간으로 평가하기 위하여 측정된 심전도 신호로부터 R-peak를 자동적으로 검출하여 심전도 관련 파리미터를 분석하는 시스템을 개발하였다. 이 시스템은 심전도 증폭기, A/D변환기, PC로 구성되었으며 National Instrument 사의 LabVIEW를 사용하여 소프트웨어를 개발하였다. 시스템 동작환경은 Microsoft사의 Window OS를 기반함으로서 시스템 이용자들에게 보다 친숙한 실험환경을 제시할 수 있다. 구현된 시스템은 실시간 HRV, Lorentz plot, LF/HF, HRV power spectrum의 3차원 선도를 디스플레이할 수 있다.