• Journal of the Ergonomics Society of Korea
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• v.24 no.1
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• pp.19-26
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• 2005

Mobile internet access using such devices as PDAs and cellular phones becomes popular as mobile technologies grow. However, the characteristics of small screen devices such as small screen size and pen-based input cause many usability problems. In this study, a human factors experiment was conducted to identify the factors affecting the usability of information search on a PDA. Factors manipulated in the experiment included use of wheel equipment, scroll dimension, and screen orientation. Task completion time, error frequency, and subjective satisfaction level were measured. In addition, various users' behavioral patterns such as scanning routes and mainly used scrolling methods were analyzed. Scroll dimension has a significant effect on task completion time. Scroll equipment and screen orientation affect subjective satisfaction level. The results could be applied to designing information structure of web sites for mobile use by providing vertical scroll and using external scroll equipments.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.1007-1008
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• 2006

This paper presents a optimal path search of mobile robot using energy efficiency. Proposed method has two goals that determining the velocity of mobile robot and finding the optimal path. We model the relationship of motors' speed and power consumption with quadratic polynomials. In order to verify the effectiveness of the proposed method, we performed simulations on the energy consumption of different paths.

• Journal of Industrial Technology
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• v.27 no.B
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• pp.37-42
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• 2007

A mobile ad hoc network (MANET) is a kind of wireless ad hoc network. It is a self-configuring network of mobile nodes connected by wireless links. Infostation is a lower cost and low power system that provides very high bit rate with limited coverage. In this study, we propose search and rescue system that combines MANET of climbers with Infostations. A climber shares location information of climbers with other climbers while climbing, and delivers the information to Infostations. This system is an intermittent network due to the mobility of nodes. From the system, we can track the locations of missing climbers. Ultimately, proposed system achieves low cost and reduces memory requirement using Infestations. We also analyze the performance of the proposed system by simulation. From the performance analysis results, we expect that the proposed system will be very useful to early detect climbers' locations in emergency situations in Korea mountain areas.

• The Journal of Information Systems
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• v.13 no.1
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• pp.59-75
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• 2004

Fixed-mobile convergence services can be defined as the combination of previously separate fixed and mobile services, and networks and commercial practices. Examples of fixed-mobile convergence services include single voice-mail box, single number and unified messaging across fixed and mobile networks. Recently as more voice is transferred to mobile networks, convergence services between fixed and mobile become more important. In Korea convergence services are only starting to become established, and are likely to become an important part of any operator's offering. In this paper, we search the different levels of fixed-mobile convergence services and the trends and regulations for fixed-mobile convergence services in major countries. And at the same time, we also suggest the corresponding Marketing strategies by operators related to fixed-mobile convergence services.

• Journal of the military operations research society of Korea
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• v.22 no.2
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• pp.73-89
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• 1996

This paper suggests the new IP, SIMIP(Simple Mobile IP), which supports a continuous mobility between a static host and a mobile host in the static TCP/IP LAN environment where mobile hosts are overlayed with cells. For designing a mobile protocol, routing optimization is very important, and it is directly related to the management mechanism of a mobile host's location information. When the mobile hosts' location information are centralized, the network has high risk when a centralized device fails. On the other hand, when they are distributed, the above problems are solved. But it requires complicated techniques in order to search the encapsulated addresses. SIMP centralizes mobile hosts' location information, minimizes the risk by automatically substituting the failed default mobile router with one of the multiple general mobile routers, and supports the optimal routing path through "default mobile router path alternation" Then since SIMIP isn't reasonable the operations informations to the chief in military operations room.ions room.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.128-130
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• 1997

In the paper a problem of search for a moving robot by another moving robot is considered. The problem is formalized as minmax and maxmin task also as a game.

• Journal of the HCI Society of Korea
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• v.11 no.1
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• pp.29-38
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• 2016

Mobile tour guide applications help tourists to search for and visit their surrounding POIs(Points of Interest) of their locations and to obtain their guide information. With the development of wearable devices like smart watches and wearable glasses, people using multiple mobile devices are increasing; a tourist may use a hand-held device, a wearable device or both to obtain tour information. However, most mobile tour guides using mobile devices provide the tour information with little consideration of their hand-held and wearable characteristics. In particular, a tourist with multiple mobile devices who search for the tour information from multiple mobile devices must input their intention separately to each device. To alleviate these problems, we propose a mobile tour guide system with the following features: one is to reduce redundant user input by sharing the touring context between hand-held and wearable devices; the other is to present tour information according to capabilities and usage pattern of the devices. The proposed system guides tourists by complementing disadvantage of the devices and also minimizes user interaction between applications and tourists.

• Journal of KIISE:Software and Applications
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• v.29 no.1_2
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• pp.30-41
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• 2002

We focus on the mobile agents which are considered as new paradigm to solve information retrieval of large volumes of data in the distributed and heterogeneous environment. The mobile agent moves the computation to data instead of large volumes of data to computations. In this paper, we propose an information retrieval model, which can effectively search data in the distributed and heterogeneous environment, using mobile agents. Our model is applied to the design and implementation of an Q&A(Question and Answer) retrieval system. Our Q&A retrieval system, called QASSMA(Q&A Search System using Mobile Agents), uses mobile agents to retrieve articles from Q&A boards and newsgroups that exist in the heterogeneous and distributed environment. QASSMA has the following features and advantages. First, the mobile retrieval agent moves to the destination server to retrieve articles to reduce the retrieval time by eliminating data traffics from the server to the client host. Also it can reduce the traffic that was occurred in the centralized network system, and reduce the usage of resources by sending its agent and running in the destination host. Finally, the mobile retrieval agent of QASSMA can add and update dynamically the class file according to its retrieval environment, and support other retrieval manner. In this paper, we have shown that our Q&A retrieval system using mobile agents is more efficient than the retrieval system using static agents by our experiments.

• The Journal of Korean Medicine
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• v.35 no.1
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• pp.41-49
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• 2014

Objectives: We propose a method to model and represent formulas in Korean medicine information systems. Methods: All the formulas were codified in the form of graphs representing the relationship between a formula and its constituents. To identify a unique formula in a graph, the formula's name, the book in which the formula was written, the book where the formula was extracted, and the page number in the extracted book are used. All the formulas and the relationship between formulas are modelled as an ontology based on graphs. Results: A formula search system was constructed using our ontology, which can represent formula information efficiently by grouping and filtering of formulas. Our formula model was also constructed as a mobile application. Conclusions: The information in our formula search system depends on our ontology. However, our model or our search scenarios could be extended according to formula information.

• IEIE Transactions on Smart Processing and Computing
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• v.4 no.2
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• pp.115-125
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• 2015

This paper presents a Cuckoo search algorithm to secure adversaries misdirecting multi-hop routing in Mobile ad hoc networks (MANETs) using a robust Trust Predicated Routing Framework with an optimized cluster head selection. The clustering technique designed in this framework leads to efficient routing in MANETs. The heavy work load in the node causes an energy drop in cluster head, which leads to re-clustering of the group, and another cluster head is selected to avoid packet loss during data transmission. The problem in the re-clustering process is that the overall efficiency of the routing process is reduced and the processing time is increased. A Cuckoo search based optimization algorithm is proposed to solve the problem of re-clustering by selecting the secondary cluster head within the initially formed cluster group and eliminating the reclustering process. The proposed framework enables a node to select a reliable and secure route for MANET and the performance can be evaluated by comparing the simulated results with the AODV routing protocol, which shows that the performance of the proposed routing protocol are improved significantly.