• The Journal of the Korea Contents Association
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• v.9 no.4
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• pp.45-54
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• 2009

The virtual world is simulated in terms of agents and the environment as the real world. Agents are able to perceive and recognize objects as well as components of the environmental elements in the virtual world. As a result, they are able to autonomously act in terms of their decision. They generate diverse situation that make the user to feel familiarity as they would be have like human beings. Such situations are constructed in terms of the concepts of the entities, relations and activities, and agents accordingly recognize the situations in terms of these concepts. In this paper, we propose the method to recognize and represent the shapes which are the most important feature among objects. Various shapes are represented in terms of primitive shapes and their spatial relations in depth. We use distance, direction, and orientation in order to represent basic spatial relation. In order to simplify basic signal processing, objects dynamically send messages of self information to agents, and refer to ontology as the knowledge base of the virtual world. Agents perceive the information from objects by comparing with schematic knowledge and instance knowledge in ontology.

• Journal of Digital Convergence
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• v.11 no.2
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• pp.235-242
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• 2013

Reputation systems aggregate users' feedback after the completion of a transaction and compute the "reputation" of products, services, or providers, which can assist other users in decision-making in the future. With the rapid growth of online e-Learning content providing services, a suitable reputation system for more credible e-Learning content delivery has become important and is essential if educational content providers are to remain competitive. Most existing reputation systems focus on generating ratings only for user reputation; they fail to consider the reputations of products or services(item reputation). However, it is essential for B2C e-Learning services to have a reliable reputation rating mechanism for items since they offer guidance for decision-making by presenting the ranks or ratings of e-Learning content items. To overcome this problem, we propose a novel collaborative filtering based reputation rating method. Collaborative filtering, one of the most successful recommendation methods, can be used to improve a reputation system. In this method, dual information sources are formed with groups of co-oriented users and expert users and to adapt it to the reputation rating mechanism. We have evaluated its performance experimentally by comparing various reputation systems.

• Korean journal of communication and information
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• v.19
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• pp.155-184
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• 2002

Mobile phone users have diversified human factors: their channel orientations are different, and the degrees of unwillingness to communicate vary. We examined the effect of human factors on the use of mobile phone, such as the diversity of mobile phone use, the appropriateness of mobile phone, and the aversion to mobile phone as well as the interpersonal communication network through mobile phone. For our sample we surveyed college students and their family members who are older than 400. We found that the more social presence a mobile phone user gets through the mobile phone, and the more familiar to the mobile phone he/she is, (1) the more diversified is the use of mobile phone service, (2) the higher is the level of acceptance of the mobile phone as an interpersonal communication media, and (3) the lower is the level of aversion to the mobile phone. In contrast, those who have some level of aversion to the face-to-face communication, seem to form very limited interpersonal communication network through mobile phone. Their use of mobile phone is also very limited.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.8
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• pp.873-877
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• 2010

CAPTCHA is a security tool that prevents the automatic sign-up by a spam or a robot. This CAPTCHA usually depends on the smart readability of humans. However, the common and plain CAPTCHA with text-based system is not difficult to be solved by intelligent web-bot and machine learning tools. In this paper, we propose a new sub-image based CAPTCHA system totally different from the text based system. Our system offers a set of cropped sub-image from a whole digital picture and asks user to identify the correct orientation. Though there are some nice machine learning tools for this job, but they are useless for a cropped sub-images, which was clearly revealed by our experiment. Experiment showed that our sub-image based CAPTCHA is easy to human solver, but very hard to all kinds of machine learning or AI tools. Also our CAPTCHA is easy to be generated automatical without any human intervention.

• Journal of Communications and Networks
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• v.18 no.5
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• pp.837-845
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• 2016

Providing a customer with tailored location-based services (LBSs) is a fundamental problem. For location-estimation techniques with radio-based measurements, LBS applications are widely available for mobile devices (MDs), such as smartphones, enabling users to run multi-task applications. LBS information not only enables obtaining the current location of an MD but also provides real-time push-pull communication service. For indoor environments, localization technologies based on radio frequency (RF) pattern-matching approaches are accurate and commonly used. However, to survey radio information for pattern-matching approaches, a considerable amount of time and work is spent in indoor environments. Consequently, in order to reduce the system-deployment cost and computing complexity, this article proposes an indoor positioning approach, which involves using Asus Xtion to facilitate capturing RF signals during an offline site survey. The depth information obtained using Asus Xtion is utilized to estimate the locations and predict the received signal strength (RF information) at uncertain locations. The proposed approach effectively reduces not only the time and work costs but also the computing complexity involved in determining the orientation and RF during the online positioning phase by estimating the user's location by using a smartphone. The experimental results demonstrated that more than 78% of time was saved, and the number of samples acquired using the proposed method during the offline phase was twice as much as that acquired using the conventional method. For the online phase, the location estimates have error distances of less than 2.67 m. Therefore, the proposed approach is beneficial for use in various LBS applications.

• The Journal of the Korea Contents Association
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• v.9 no.11
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• pp.289-296
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• 2009

In this study, I presented power control unit with potential use in the magnetic stimulation of biological systems. The effect of the magnetic stimulation depends on the geometry and orientation of the induced electric field as well as on the current pulse waveform delivered by the stimulator coil. TMS is achieved from the outside of the head using pulses of electromagnetic field that induce an electric field in the brain. There are numerous possibities in the applications TMS, such as diagnosis and therapy through the brain stimulation. These factors are very important to define the equipment requirements and characteristics in that the topology of the power supply and the size and geometry of the coil. The proposed solution is the generation of current pulses with variable amplitude and duration, according to a user defined input. Another solution is the topology that uses elements to store and transfer energy from the power source to the load. In addition to proposed topology, an adequate control strategy and right set of the power circuit parameters made possible to obtain unipolar waves and bipolar waves.

• Composites Research
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• v.25 no.4
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• pp.126-132
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• 2012

It is useful to have a quick analysis program in early design process for feasibility studies of composite cylinder because it takes long time and is not cost effective by commercial programs. In this paper, a GUI program is developed to calculate the stress distribution in a fast manner with the properties, the orientation angle and the stacking sequence of composite material using LabVIEW. The stress distributions of an autofrettaged cylinder and a composite cylinder with internal pressure are compared with the results by MSC Nastran/patran. The stress distribution of steel/composite cylinder is compared with the values of existing studies, and is proved. Furthermore, by calculating the stress distribution of an autofrettaged steel/composite cylinder, the stress distribution is estimated, and the program will be useful in an early design phase for feasibility studies.

• Journal of the Korea Computer Graphics Society
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• v.21 no.4
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• pp.19-26
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• 2015

This paper presents a method for optimizing a carrying pose of human body for a given object. The inputs are articulated human body model and and arbitrary-shaped object. We assume that the object is big and heavy, so that both arms should be used to carry it. Unlike small and light objects, big and heaby objects can be hold by only a small range of body poses while keeping a physical statbility. We first introduce an algorithm that evaluates a physical stability of a given human body pose and object state (position and orientation). Then, we define a configuration space and search the space for the most stable carrying pose by using the evaluation algorithm. Finally, to demonstrate the usability of our method, we present the results which each is experimented with different shaped objects and additional user conditions.

• Fashion & Textile Research Journal
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• v.25 no.4
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• pp.449-459
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• 2023

This study focuses on online communities and the ritual conversations of users when participating in sharing activities. The study aims to understand the social and psychological phenomena that occur between users within the context of Erving Goffman's impression management theory. Case studies and a content analysis were conducted by collecting posts and comments related to fashion products in the sharing activities category on Naver Cafe "Family Sale." On the one hand, the study identified various disposition motives among givers, including a desire for recognition, self-expression, activation of the community, emotional sympathy, goodwill, play, and simple disposition. On the other hand, receivers' purchase motives included the need for a product, reciprocation based on a sense of belonging, play, gift-giving, and simple response. Analyzing the posts of givers and the comments of receivers of fashion products using impression management strategies and dramaturgical analysis, the study interpreted users' impression management and revealed propensities in fashion consumption: fashionability, conspicuousness, value orientation, and economic feasibility. Through ritual conversations, users managed to attain emotional stability on an individual level, while they reinforced collective bonds on a social level. They fulfilled their roles with their own narratives to achieve personal and collective goals in a non-face-to-face situations and non-monetary transactions. This study is significant in that it examines normative communication in an online community and user relationships to understand a recent phenomenon in the fashion industry.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.7
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• pp.1807-1822
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• 2023

Innovation and rapid increased functionality in user friendly smartphones has encouraged shutterbugs to have picturesque image macros while in work environment or during travel. Formal signboards are placed with marketing objectives and are enriched with text for attracting people. Extracting and recognition of the text from natural images is an emerging research issue and needs consideration. When compared to conventional optical character recognition (OCR), the complex background, implicit noise, lighting, and orientation of these scenic text photos make this problem more difficult. Arabic language text scene extraction and recognition adds a number of complications and difficulties. The method described in this paper uses a two-phase methodology to extract Arabic text and word boundaries awareness from scenic images with varying text orientations. The first stage uses a convolution autoencoder, and the second uses Arabic Character Segmentation (ACS), which is followed by traditional two-layer neural networks for recognition. This study presents the way that how can an Arabic training and synthetic dataset be created for exemplify the superimposed text in different scene images. For this purpose a dataset of size 10K of cropped images has been created in the detection phase wherein Arabic text was found and 127k Arabic character dataset for the recognition phase. The phase-1 labels were generated from an Arabic corpus of quotes and sentences, which consists of 15kquotes and sentences. This study ensures that Arabic Word Awareness Region Detection (AWARD) approach with high flexibility in identifying complex Arabic text scene images, such as texts that are arbitrarily oriented, curved, or deformed, is used to detect these texts. Our research after experimentations shows that the system has a 91.8% word segmentation accuracy and a 94.2% character recognition accuracy. We believe in the future that the researchers will excel in the field of image processing while treating text images to improve or reduce noise by processing scene images in any language by enhancing the functionality of VGG-16 based model using Neural Networks.