• Journal of the Korean Data and Information Science Society
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• v.18 no.3
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• pp.659-668
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• 2007

Collaborative filtering approach for recommender systems are now widely applied in e-commerce to assist customers to find their needs from many that are frequently available. this approach makes recommendations for users based on the opinions to similar users in the system. But this approach is opened to users who present their preference to items or acquire the preference information form other users, noise in the system makes significant problem for accurate recommendation. In this paper, we analyze the relationship between the standard deviation of preference ratings for each user and the estimated ratings of them. The result shows that the possibility of the pre-filtering condition which detecting the factor of bad effect on the prediction of user's preference. It is expected that using this result will reduce the possibility of bad effect on recommender systems.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.3
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• pp.1-10
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• 2012

Recently, Social Network services(SNS) is gaining popularity as Facebook and Twitter. Popularity of SNS leads to active service and social data is to be increased. Thus, social search is remarkable that provide more meaningful information to users. but previous studies using social network structure, network distance is calculated using only familiarity. It is familiar as distance on network, has been demonstrated through several experiments. If taking advantage of social context data that users are using SNS to produce, then familiarity will be helpful to evaluate further. In this paper, reflect user's attention through comments and tags, Facebook context is determined using familiarity between friends in SNS. Facebook context is advantageous finding a friend who has a similar propensity users in context of profiles and interests. As a result, we provide a blog post that interest with a close friend. We also assist in the retrieval facilities using Near Field Communication(NFC) technology. By the experiment, we show the proposed soicial search method is more effective than only tag.

• Journal of Information Science Theory and Practice
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• v.9 no.1
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• pp.79-89
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• 2021

This study explores Facebook use in Vietnamese academic libraries by analysing libraries' posts on their Facebook pages and library users' interaction with those posts. A total of 260 posts on four academic libraries' Facebook pages were examined using the content analysis method. The findings reveal that Facebook was mainly used to encourage reading and to transmit announcements. Most of the academic libraries published one post a week. The photo was the most frequent media type of libraries' posts and gained a higher level of interaction than other posts. According to the research results, the user engagement was low, and the user interaction with libraries' posts generally was in the form of reaction. The findings can help better understand Facebook use in Vietnamese academic libraries and may assist libraries in creating a plan for using Facebook more effectively.

• Journal of Korean Port Research
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• v.13 no.2
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• pp.245-254
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• 1999

This paper aims to derive the strategies for the container terminal in Pusan. So it has focused on analyzing the current conditions of Pusan container terminal while evaluating the difficulties arising from the existing facilities/equipment and the operating system in the Pusan Korea Container Terminal through the workers at the container terminal and at off-dock CY. The object of this study is to assist the existing terminals to operate the facilities/equipment reasonably and to contribute shaping the ports policy which will be the basis of constructing new ports that will remain competitive while maintaining superiority over the ports in northeast area. According to the analysis 68% of the supplier answered that their terminal services which are the most important factor in running a terminal were superior to the other while only 28% of the user answered that they thought the current services were superior. For the areas of supplementing the terminal the people working at the terminal answered in the order of business operation equipment the number of berth service and management ability while the user answered in the order of service computer system transportation system and equipment. According to the regression analysis it became clear that there should be more effort toward improving or supplementing the facility scale facility usage charge transportation facilities which will assist in developing competitiveness of the terminal. It was also noted that management ability and business ability were mentioned as the important factors in operating a terminal.

• Science of Emotion and Sensibility
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• v.14 no.1
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• pp.83-92
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• 2011

Because of the development of digital technologies and information-oriented products, the importance of user interface design and usability are increasing in recent year. So we need a systematic and rational way to measure and manage how effective the improvement of user interface is. The purpose of this study is to develop measurable ‘Usability Improvement Index' which signify how much usability has improved in user interface design. First, I made the framework of measuring and evaluating usability through analysis of existing usability metrics and previous studies. Then, I suggested the process of calculating 'Usability Improvement Index' based on categorizing characteristics of measurable usability and definition of usability metrics. The process is as in the following : measuring the present level of usability, analysis of problems, making alternative user interface design, measuring the improved level of usability, calculating Usability Improvement Index. For verification, the case study on application of Usability Improvement Index to usability improvement of application software of digital camcorder presented. This study is expected to assist 'goal oriented user interface design' and to manage usability systematically.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.9 no.1
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• pp.81-87
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• 2015

In order for a Power Assisted Wheelchair (PAW) to maintain a straight driving direction, the same force must be delivered to both wheels. However, a human has different strength between the right and left arms, and cannot control the force uniformly at all times. Therefore, appropriate assist torque shall be generated from unbalanced human torque inputs by detecting the user intention, in order to maintain direction uniformly in straight sections or change direction quickly in curved sections. In this study, a special function is proposed to detect the intention of drivers on the basis of temporal similarity between the input torque signals, and a torque balancing technique based on this function is proposed. In the experiments, the effectiveness of the proposed torque balancing method are verified.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_3
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• pp.1315-1323
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• 2023

Rehabilitation assistive devices not only assist the rehabilitation therapy and daily life of the disabled and the elderly, but also assist the labor of their caregivers, so various functions are required to improve their quality of life. In this study, a design method considering its practicality is introduced for an active rehabilitation assistive device that can perform both standing and walking assistance by driving various actuators. For this purpose, the force required to assist standing was calculated using statics with the body segmentation method. Also, the overturning stability of the device was verified for various physical conditions and postures. The actuator in the active rehabilitation assistive device was operated by a patient using a graphical user interface in an embedded computer and a touch panel for easy usage. The detailed design was performed for implementation through the help of 3D-CAD and the finite element analysis, and a prototype was produced. Finally, it was proven that the design goal was satisfied by experimental validation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.3 no.5
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• pp.423-443
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• 2009

We present the design and implementation of a unique sensing and actuation application -- the Illuminator: a sensor network-based intelligent light control system for entertainment and media production. Unlike most sensor network applications, which focus on sensing alone, a distinctive aspect of the Illuminator is that it closes the loop from light sensing to lighting control. We describe the Illuminator's design requirements, system architecture, algorithms, implementation and experimental results. The system uses the Illumimote, a multi-modal and high fidelity light sensor module well-suited for wireless sensor networks, to satisfy the high-performance light sensing requirements of entertainment and media production applications. The Illuminator system is a toolset to characterize the illumination profile of a deployed set of fixed position lights, generate desired lighting effects for moving targets (actors, scenic elements, etc.) based on user constraints expressed in a formal language, and to assist in the set up of lights to achieve the same illumination profile in multiple venues. After characterizing deployed lights, the Illuminator computes optimal light settings at run-time to achieve a user-specified actuation profile, using an optimization framework based on a genetic algorithm. Uniquely, it can use deployed sensors to incorporate changing ambient lighting conditions and moving targets into actuation. Experimental results demonstrate that the Illuminator handles various high-level user requirements and generates an optimal light actuation profile. These results suggest that the Illuminator system supports entertainment and media production applications.

• Journal of Multimedia Information System
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• v.2 no.2
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• pp.223-232
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• 2015

In this system, mobile devices are not independent, they can communicate with each other, one device's change can affect the whole system or other devices. To achieve the above mentioned A Self-Reconfigurable System of Contents, through discover the device and connect process, to establish the connection between the mobile devices. After user assigns two dimension display type, the user can select content to input the system, contents are portioning and broadcast to devices. The system can self-reconfigure contents rapidly and exactly. This technique supports contents self-reconfiguration for devices remove, addition and position exchange. In this paper, when the user uses the hand contacts device, the device sends a signal to assist the system to detection device's position. The system does not need to get accurate devices moving direction, just according to all changed devices position to judge where the devices destination is. This research develops an application according to this technique, and the real machine tests the application using Android platform. Some communication protocols and mathematical modeling methods are proposed. These methods can also be used in other Internet of Things (IoT) fields, such as Drones Navigation, Smart Home, and Informational City management.

• Journal of information and communication convergence engineering
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• v.9 no.1
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• pp.100-104
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• 2011

In software system development, an application interface is the main communication platform between human developers and applications. Interaction in any software application requires human's mental and physical activities. Although software systems have increased drastically in diverse sectors and many forms to quench human's needs and satisfactions, human always concern about the ease in usability of the software application so that it can be easily understood and navigated. Since many software developers still focus on the quantity of contents instead of the quality of the interface from the user's point of view, it is important to address human factors need in the early stage of the design and to continue addressing them during the entire stages of the software design for the persistent support of usability. In this paper, we propose the Modified Prototype Model (MPM), which helps the software designers and developers to design user-friendly software systems with easy-to-navigate interfaces by uncovering human factors in a convenient way. Moreover, we propose methods that assist to identify more human factors regarding software design. In this paper, we also study the implications of the proposed model and the proposed methods.