• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.720-723
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• 1997

This paper presents a cooperative control method for multiple robots. This method is based on local sensors. The proposed method integrates all information obtained by local perception through a set of sensors and generates commands without logical conflicts in designing control logic. To control multiple robots effectively, a global control strategy is proposed. These methods are constructed by using AND/OR logic and transition firing sequences in Petri nets. To evaluate these methods, the object-searching task is introduced. This task is to search an object like a box by two robots and consists of two sub-tasks, i.e., a wall tracking task and a robot tracking task. Simulation results for the object-searching task and the wall tracking task are presented to show the effectiveness of the method.

• ETRI Journal
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• v.38 no.3
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• pp.518-528
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• 2016

The searching of an extensive document database for documents that are locally similar to a given query document, and the subsequent detection of similar regions between such documents, is considered as an essential task in the fields of information retrieval and data management. In this paper, we present a framework for such a task. The proposed framework employs the method of short-read mapping, which is used in bioinformatics to reveal similarities between genomic sequences. In this paper, documents are considered biological objects; consequently, edit operations between locally similar documents are viewed as an evolutionary process. Accordingly, we are able to apply the method of evolution tracing in the detection of similar regions between documents. In addition, we propose heuristic methods to address issues associated with the different stages of the proposed framework, for example, a frequency-based fragment ordering method and a locality-aware interval aggregation method. Extensive experiments covering various scenarios related to the search of an extensive document database for documents that are locally similar to a given query document are considered, and the results indicate that the proposed framework outperforms existing methods.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.6
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• pp.2282-2303
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• 2021

To solve the problems of heavy computing load and system transmission pressure in energy internet (EI), we establish a three-tier cloud-edge integrated EI network based on a cloud-edge collaborative computing to achieve the tradeoff between energy consumption and the system delay. A joint optimization problem for resource allocation and task offloading in the threetier cloud-edge integrated EI network is formulated to minimize the total system cost under the constraints of the task scheduling binary variables of each sensor node, the maximum uplink transmit power of each sensor node, the limited computation capability of the sensor node and the maximum computation resource of each edge server, which is a Mixed Integer Non-linear Programming (MINLP) problem. To solve the problem, we propose a joint task offloading and resource allocation algorithm (JTOARA), which is decomposed into three subproblems including the uplink transmission power allocation sub-problem, the computation resource allocation sub-problem, and the offloading scheme selection subproblem. Then, the power allocation of each sensor node is achieved by bisection search algorithm, which has a fast convergence. While the computation resource allocation is derived by line optimization method and convex optimization theory. Finally, to achieve the optimal task offloading, we propose a cloud-edge collaborative computation offloading schemes based on game theory and prove the existence of Nash Equilibrium. The simulation results demonstrate that our proposed algorithm can improve output performance as comparing with the conventional algorithms, and its performance is close to the that of the enumerative algorithm.

• Journal of Internet Computing and Services
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• v.3 no.2
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• pp.97-108
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• 2002

A user with a specific information need will often need to query several search engines before finding relevant documents. To address the problem of navigating the search engines, agents are used. In general, an agent is a program that can perform a particular task automatically, when appropriate or upon request by another program. In this paper, we design and implement the education information search system for children: using Information gathering agent that is called Edulnfo4k. The information gathering agent periodically visits several portal web sites for children: Ggureogi of Yahoo Korea, Junior of Naver and Gaegujaengi of Hanmir, collects the education or learning information for children, stores the collected information into database. Then, causal users can search the education information for children from database through a uniform user interface, conveniently. As the result, we know that Edulnfo4k provides integrated search without query in several search engines.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.6
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• pp.2422-2443
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• 2020

This paper studies a single-user Mobile Edge Computing (MEC) system where mobile device (MD) includes an application consisting of multiple computation components or tasks with dependencies. MD can offload part of each computation-intensive latency-sensitive task to the AP integrated with MEC server. In order to accomplish the application faultlessly, we calculate out the optimal task offloading strategy in a time-division manner for a predetermined execution order under the constraints of limited computation and communication resources. The problem is formulated as an optimization problem that can minimize the energy consumption of mobile device while satisfying the constraints of computation tasks and mobile device resources. The optimization problem is equivalently transformed into solving a nonlinear equation with a linear inequality constraint by leveraging the Lagrange Multiplier method. And the proposed dual Bi-Section Search algorithm Bi-JOTD can efficiently solve the nonlinear equation. In the outer Bi-Section Search, the proposed algorithm searches for the optimal Lagrangian multiplier variable between the lower and upper boundaries. The inner Bi-Section Search achieves the Lagrangian multiplier vector corresponding to a given variable receiving from the outer layer. Numerical results demonstrate that the proposed algorithm has significant performance improvement than other baselines. The novel scheme not only reduces the difficulty of problem solving, but also obtains less energy consumption and better performance.

• Journal of the Ergonomics Society of Korea
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• v.25 no.2
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• pp.23-32
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• 2006

Window buttons located on a task bar provide information about windows that have been open as well as active. When the number of buttons on the task bar increases, the button size gets smaller and as a result, it is more difficult to identify. This study proposes new alternatives of presenting window buttons to search for a target button efficiently. An experiment was conducted to evaluate the usability of the new. Factors manipulated in the experiment include 'button arrangement methods' and 'order of buttons'. The 'button arrangement methods' factor is composed of three levels, 'one line', 'changeable line', and 'grouping buttons'. The 'order of buttons' factor is composed of three levels, 'fixed order', 'click-right', and 'order control by user'. The results showed that the main effects were significant in search time. In subjective satisfaction, the interaction effect was also significant. The results could be applied to the design of small screens such as PDA or cellular phones.

• Journal of the Korean Society for Library and Information Science
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• v.48 no.2
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• pp.379-398
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• 2014

This pilot study explored the effect of mental demand on a Web searcher's thoughts, emotions, efforts, and performance in Web searches in order to address whether or not there is any difference between searchers exposed to mental demand manipulation and searchers not exposed. Research data were collected via think-aloud protocol (TAP) with a dual-task in experiments and interviews with 10 subjects who participated in this study. For the searcher's thoughts, relevance judgment was found to be hindered by mental demand. For the searcher's emotions, the experimental group was more frustrated than the control group. With respect to the searcher's efforts, searchers for the experimental group with mental demand manipulation were more likely to spend more time, make fewer queries, and visit fewer pages but work harder to find more relevant information that they needed. Lastly, with regard to the searcher's performance, it is likely that performance was highly dependent upon the completion of the search tasks for both groups. The NASA-TLX six components and cognitive load scores of searchers did not make a significant difference in the outcome. The findings support the use of a dual-task methodology as a promising approach for the assessment of cognitive load induced by complex Web searches.

• Journal of Korean Library and Information Science Society
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• v.35 no.2
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• pp.199-218
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• 2004

The purpose of this study is to examine the emotional and behavioral characteristics of information seeking of university students in context in which a class assignment should be completed. An attempt was made to understand better individualized and selective behavior observed while seeking information in the commonly defined context. Data was collected from content analysis of self-reports by 54 university students majoring in library and information science. Major findings were analyzed in relation to the preception and feelings over, and barriers and strategies of seeking information, and the use of information resources.

• Journal of the Korean Society for Library and Information Science
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• v.52 no.3
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• pp.289-334
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• 2018

Even though information in many languages other than English is quickly increasing, English is still playing the role of the lingua franca and being accounted for the largest proportion on the web. Therefore, it is necessary to investigate the key features and differences between "information searching behavior using mother tongue as a search language" and "information searching behavior using English as a search language" of users who are non-mother tongue speakers of English to acquire more diverse and abundant information. This study conducted the experiment on the web searching which is applied in concurrent think-aloud method to examine the information searching behavior and the cognitive process in Korean search and English search through the twenty-four undergraduate students at a private university in South Korea. Based on the qualitative data, this study applied the frequency analysis to web search pattern under search language. As a result, it is active, aggressive and independent information searching behavior in Korean search, while information searching behavior in English search is passive, submissive and dependent. In Korean search, the main features are the query formulation by extract and combine the terms from various sources such as users, tasks and system, the search range adjustment in diverse level, the smooth filtering of the item selection in search engine results pages, the exploration and comparison of many items and the browsing of the overall contents of web pages. Whereas, in English search, the main features are the query formulation by the terms principally extracted from task, the search range adjustment in limitative level, the item selection by rely on the relevance between the items such as categories or links, the repetitive exploring on same item, the browsing of partial contents of web pages and the frequent use of language support tools like dictionaries or translators.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.10
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• pp.1835-1844
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• 2007

Recently there have been some positive evidences on the effects of learning in a virtual environment. However, most of these educational VR systems were not deeply considered in the design of drawing a learner's attention on lesson contents, which would help enhance retained memory. Hence, a study was conducted to measure 17 subjects' attention states using EEC, ECG, GSR, and eye-tracking and their behaviors while they were given guided search task or exploration task in a virtual environment consisting of five major events. It also analyzed the subject's remembered items after their VR experiences using a surrey. This paper Int describes an overview of the ocean virtual environment used in this study, and it then explains the experimental design, apparatus, and method. It will also discuss the results by a detail analysis (in a whole VR session as well as event-related 10-second 33 sub-sessions) with the subjects' attention states and their retained memory after the learning.