• Journal of KIISE:Databases
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• v.33 no.7
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• pp.655-667
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• 2006

Due to the rapid development in mobile communication technologies, the usage of mobile devices such as cellular phones and PDAs becomes increasingly popular. One of the best ways to maximize the usability of mobile devices is to make them aware of their current locations and the locations of other fixed and mobile objects. In this paper, we propose a cost-effective Bus Information System, ACE-BIS, which utilizes a mobile device to retrieve the bus routes to reach a destination from the current location. To accomplish this task, ACE-BIS maintains a small amount of information on bus stops and bus routes in a mobile device and runs a heuristic routing algorithm based on such information. When a user asks more accurate route information or calls for a 'leave later query', ACE-BIS entrusts the task to a server into which real-time traffic and bus location information is being collected. By separating the roles into a mobile device and a server, ACE-BIS is able to provide bus routes at the lowest cost for wireless communications, without imposing much burden to a server. The results of extensive experiments revealed that ACE-BIS is effective and scalable in most experimental settings.

• The Journal of the Korea Contents Association
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• v.14 no.5
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• pp.289-297
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• 2014

The purpose of this study was to investigate the relation between smartphone addiction and interpersonal competence of college students using social network service(SNS) through smartphones. This study used a descriptive study design. The convenience sample consisted of 502 college students in six cities. The data were collected from May to June in 2012 using Korean Smartphone Addiction Proneness Scale and Interpersonal Competence Questionnaire. Descriptive statistics, ${\chi}^2$-test, t-test, analysis of variance, and Pearson correlation coefficient were used to analyze the data. The results showed that 24.8% of SNS users were considered as a risk group, while 75.2% were normal user group. There were no significant differences of interpersonal competence between risk group and normal user group in the SNS users. However, risk group had higher self-disclosure scores than normal user group. The subjects who had higher scores for virtual life, one of smartphone addiction subdomains, had lower interpersonal competence and those with higher smartphone addiction scores showed lower score of managing interpersonal conflict in subdomains of interpersonal competence. These findings would contribute in development of preventive interventions for smartphone addiction and improvement program for interpersonal competence in college students.

• Archives of design research
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• v.19 no.5 s.67
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• pp.55-64
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• 2006

As digital systems were introduced to automotive design in the mid 1980s, the design process has adopted many digital programs to save time compared to the conventional hand drafting. Digital technology was introduced not only to satisfy the reeds of the global environment, as the number of automobiles exported to many different parts of the world has increased, but also to save time and effort in developing several models of quality automobiles. Therefore, every automotive manufacturer in the world has expanded its virtual reality(VR) studio to establish visualization systems that visualize automobiles in the actual size and a co-operation system that enables simultaneous feedback from all of its design studios around the world. Unlike the existing design reviewing methos, the new improved feedback system is assessed as a reasonable method to evaluates and understand how the automobiles are actually manufactured in simulation. It is especially helpful when advanced products and concept cars require fast results. Other strengths of the new system include shorter development period, cost efficiency, no more manual labor, various designs within a short period of time, and realistic visualization of concepts. Large-scale products, including automobiles, need to be projected in the actual size and high clarity through the Power-wall System and are examined in a virtual space called a Cave. Therefore, it took much time to establish digital infrastructure. An infrastructure would constantly require system improvement and performance enhancement, but it is certain that now is the right time for the take-off to utilizing the strengths of digital design and improve the weaknesses. In this respect, this study provided an understanding of the importance of digital design based on digital reinforcements and examined an effective utilization of digital technology for an efficient development of automobiles in the future.

• Science of Emotion and Sensibility
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• v.22 no.3
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• pp.65-76
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• 2019

Augmented reality (AR) is the technology in which a virtual image made by computer is integrated with the real world. Food is one of the most popular products purchased online. In this study, we investigated how the presentation of food images with AR affects purchase intention and user engagement. We hypothesized that purchase intention was increased more by AR food images than by static food images. We also examined whether user engagement mediates the relationship between image presentation format and purchase intention. To test this hypothesis, participants in one group saw AR food images, and participants in another group saw static food images on an iPad. All participants then answered questions about user engagement and purchase intention. As predicted, participants who saw an AR food image reported higher user engagement and higher purchase intention than did those who saw a static food image. The indirect effect of user engagement was also significant, and the link between image presentation format and purchase intention was fully mediated by user engagement. We also found that aesthetic appeal, one of the sub-factors of user engagement, fully mediated the link between image presentation format and purchase intention. Thus AR images of food images were aesthetically more appealing, which led to higher purchase intention. These findings suggest that AR technology can be used effectively as a way to advertise food.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.2
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• pp.269-286
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• 2018

Backfill injection pressure in shield TBM affects not only ground settlement but also adjacent underground structures. Therefore, it is essential to estimate a suitable backfill injection pressure in advance in design stage. In this paper, seven suggested equations worldwide to calculate the backfill injection pressure were reviewed and compared. By assuming 6 cases of virtual ground condition, backfill injection pressures were calculated and analyzed. it was confirmed that the backfill injection pressure increases as the depth of overburden increases, but the increasing ratio decreases. The numerical analysis was carried out by applying the calculated backfill injection pressure to investigate the influence of backfill injection pressure on the settlement of surface and crown of tunnel. It was confirmed that the final settlement at the surface and crown of tunnel on the both unsaturated and saturated condition are more influenced by the applied face pressure than the applied backfill injection pressure. In addition, the effect of backfill injection pressure decreases as the depth of overburden increases, and the effect of backfill injection pressure increases as the applied face pressure decreases.

• The Journal of the Korea Contents Association
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• v.18 no.9
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• pp.125-140
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• 2018

Due to rapid development of semiconductor technology, embedded systems have been developed from single-functional system to the multi-functional system. The system composed of software that has different criticality level is called Mixed-Criticality System. Currently, the project related to the Mixed-Criticality System is accelerating the efforts to seek the development direction and take technical initiatives led by EU and USA where the related industry has developed, but the movement in Korea is yet insignificant. Therefore, it is urgent to perform the research and project of various basic technologies to occupy the initiative for the related technology and market. In this paper, we analyze the trends of major project researches and developments related to the MCS. First, after defining the definition of the MCS and system model, we analyze the underlying technology constituting the MCS. In addition, we analyze the project trends of each country researching MCS and discuss the future research areas. Through this study, it is possible to grasp the research trends of the world in order to establish the research direction of the MCS and to lay the foundation for the integration into the military system.

• Journal of Korea Multimedia Society
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• v.5 no.6
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• pp.712-729
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• 2002

In this study, we evaluated degree of importance of e-marketplace solution selection factors. Factor analysis was conducted to find out relationships among various variables which come from literature survey. The result shows that 16(sixteen) -selection variables regarding solution characteristics could be grouped into four areas 'flexibility', 'ease of use', 'security', and 'economy'. And 11(eleven) selection variables regarding to vendor characteristics could be grouped into three areas, 'vendor's support', vendor's general situation', and 'vendor's business accomplishment`. Through various analysis, we found important factors for 3 types of operational companies, buyer-biased, seller biased and neutral. 'Security for data item' was showed as the most important factor for all kind of B2B operational companies. For buyer-biased companies, additional supporting manpower, solution education, and educational cost are shown to be more important factors than others. Place of education, education hours and education level are important for 'Neutral' companies. And the factor 'market share of vendor' are important for 'seller biased' companies.

• Environmental and Resource Economics Review
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• v.13 no.2
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• pp.219-243
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• 2004

Generally, electricity market has monopoly market structure because of need of enormous investment for infrastructure. However, the introduction of competition in network industry as electricity is a tendency of the world with decreasing the effects of economy of scale due to the advancement of technology. Now, electricity industry restructuring is in progress but the competition in electricity retail market is not in force yet in Korea. Whether a effective competition exist or not is very important to policy decision maker who drive restructuring, but there are small numbers of quantitative researches on that. In this study, we estimated the effectiveness of competition in the electricity retail market through switching costs. If switching costs are high, consumers actually can be locked in incumbent firm in spite of introduction of competition. Therefore switching is a critical factor to determine effectiveness of competition and to estimate the size of switching costs quantitatively can proffer the information about whether the competition in the electricity retail market is effective or not in the future. We estimated switching costs using consumer' stated-preference data by conjoint analysis. In according to estimation results, the cost of switching process is not so high, but the relative brand loyalty of an incumbent company is significantly high. And the price is considered as the most important factor choosing an electric service commodity. Based on the empirical results, it is possible to analyze the relationship between suppliers' competitiveness resulted from management efficiency and customers' switching possibilities. The paper therefore provides guidance for suppliers in deciding to enter into retail competition and for policy makers in introducing retail competition. And it has a significance of estimating the switching costs directly.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.5
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• pp.245-256
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• 2002

Shadows are important elements in producing a realistic image. Generation of exact shapes and positions of shadows is essential in rendering since it provides users with visual cues on the scene. It is also very important to be able to create soft shadows resulted from area light sources since they increase the visual realism drastically. In spite of their importance. the existing shadow generation algorithms still have some problems in producing realistic shadows in real-time. While image-based rendering techniques can often be effective1y applied to real-time shadow generation, such techniques usually demand so large memory space for storing preprocessed shadow maps. An effective compression method can help in reducing memory requirement, only at the additional decoding costs. In this paper, we propose a new image-barred shadow generation method based on image warping. With this method, it is possible to generate realistic shadows using only small sizes of pre-generated shadow maps, and is easy to extend to soft shadow generation. Our method will be efficiently used for generating realistic scenes in many real-time applications such as 3D games and virtual reality systems.

• Korean Journal of Cognitive Science
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• v.29 no.2
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• pp.105-120
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• 2018

Current neuroscience views the mind-body problem from the monistic perspective which claims that the human mind is the result of brain activity and that the mind shuts down when the brain does. However, a considerable number of lay people still believe in the existence of the soul and the afterlife, concepts that are hard to explain from the monistic perspective. This study examines whether lay people think that the mind of the dead is capable of exceeding the physical constraints if they believe that such mind exists. After reading one of three vignettes which describes the state of the protagonist as alive, dead, or brain dead, the participants evaluated the protagonist's general mental capacity and transcendental ability to obtain new information. The participants rated that the dead protagonist had more 'transcendental ability to obtain new information' than the alive one if they evaluated high general mental capacity to the protagonist. In addition, unlike the alive condition, in the dead and the brain dead condition, there was a correlation between the general mind capacity rating and the transcendental ability rating. The results suggest that lay people expect the mind of the alive and the dead to be different, as they believe the latter's general mind capacity connotes transcendental ability. We also found that the participants' religiosity affected their beliefs about the transcendental ability of dead person.