• Journal of the Korean Society for information Management
• /
• v.33 no.4
• /
• pp.225-244
• /
• 2016

As technology progresses, the supply and use of smartphones has become increasingly popular and has significantly transformed modern life. However, users still feel uncomfortable running some mobile apps, as many are created without a thoughtful consideration of usability. Usability evaluations involve several methodologies to identify specific problems in light of various principles. Although usability testing was initially centered on physical services, it has gradually evolved to consider user satisfaction as its main concern. Public transportation applications should be accessible to everyone, and studies should focus on the user's perspective. However, previous user surveys have concentrated on applications' technical aspects or visual design. As a result, there has been a lack of general usability evaluations. This study aimed to evaluate the usability of mobile transportation applications in real life, with a focus on public transportation in Seoul. All the participants were asked to complete a task, an in-depth interview, and a questionnaire survey. In summary, the results suggest that users do not find inappropriate information attractive when it does not satisfy their purpose of use, but rather tend to consider it as interference.

• Korean Institute of Interior Design Journal
• /
• v.17 no.6
• /
• pp.152-160
• /
• 2008

The Cases of advanced nations which have advanced welfare policy, they have headed for the deinstitutionalization and the protection of the local society. So they have expanded and improved the various policies and welfare facilities to be able to keep daily life on the base of local area. Many problems have been caused by rising the average life span of the elderly in Korea now. Under the tendency, there have been many alternative proposals to solve the problems. One of those proposals, the deinstitutionalization theory that is rated the ideal way, is the community-based care than the care in facilities for the elderly. It shows that the most ideal facility for the care is Daycare center and that it matters the system of spatial construction and standard of the facilities. Under the undetailed Korean standard of facility design, it is very important that system of spatial construction to correspond to the needs of the users and standard of the facilities are prepared from the point of view of the standard design of the domestic facilities for the elderly. The study of the book grasps the regional present situation of the domestic Daycare center and surveys the tendency of the stay and features of occupation of the user there through some case, and aims to have a thorough grip of the spatial scale by the user's behavior. It is to utilize for a proposal for preparation of the space scale, and an institution standard corresponding to user's needs in a Daycare center.

• Journal of Korea Game Society
• /
• v.18 no.1
• /
• pp.27-38
• /
• 2018

Today, the field that actively utilizes HMD, which is a representative implementation device of virtual reality, is game. We have frequently used interface design using metaphor to user interface of HMD based virtual reality game. The purpose of this study is to find out the metaphor types that appear in the game interface of the virtual reality FPS genre of HMD devices, which is a new medium. As a result of research, the metaphor types appearing on multiple interfaces have navigation, predictability-based, familiarizing, and physical world metaphor in terms of information perception and predictability-based and familiarizing metaphor in term of control action. It is considered possible to construct a correct mental model. It is expected that the stability-based metaphor to prevent user mistakes and the presentation metaphor to identify the identity of information space will be needed in the future.

• Journal of Software Engineering Society
• /
• v.24 no.1
• /
• pp.19-26
• /
• 2011

Since smart phones have various embedded sensors and high portability/usability, they have emerged as suitable targets to collect information and to provide intelligent services. That is, with a smart phone, we can collect information about user's circumstances and phone usage from sensors and infer his/her current state which is the significant basis for context-aware services. However, a service system should be founded on a context model to ensure reasonable context-awareness, because context information the system needs depends on its target services. Therefore, in this paper, we propose a hierarchical mobile context model for context inference of smart phone users in their daily life. We classify high-level context which can be draw from sensing data into three levels, Context-Behavior-Situation, and define inference methods for each level. With our mobile context model, we can user's meaningful context in his/her daily life besides simple actions or states.

• Journal of Digital Convergence
• /
• v.13 no.10
• /
• pp.59-68
• /
• 2015

This study compared and analyzed the connection use, using behaviors and life satisfaction of paid users and free users in accordance with the business models of convergence N-screen service providers. It also analyzed factors that influence users' satisfaction at a personal life level, a relationship-based life level and a group-based life level. The study result showed the different connection use levels of broadcast contents by paid and free users of the N-screen service have a statistically significant meaning. The result also showed the personal satisfaction level of paid users is higher than that of free users. It also turned out that factors that influence life satisfaction differ according to whether or not the users paid for the service. Also, academic background and content consumption expenses affected life satisfaction level of free users while connection use of broadcast contents affected the one of paid users. This study provided an insight on the current domestic N-screen market situation and suggested business strategies which could help find business models.

• Proceedings of the Korea Contents Association Conference
• /
• 2009.05a
• /
• pp.614-619
• /
• 2009

This study aims at diagnosing the relationship among user's security need Sufficiency, customer satisfaction and life satisfaction in electronic security system. For the achievement of this study selected electronic security system users in Seoul as a population for about 25 days from June 20th, 2008 to July 15th, 2008, segmented Han river based in 5 areas and extracted 1 dong per each area. This study selected 378 peoples by distributing 400 unities in total for each 80 peoples throughout purposive sampling method. The final 302 samples were used in statistics. Collected data was analyzed based on the aim of this study using SPSSWIN 16.0, and factor analysis, reliability analysis, stepwise multiple regression analysis and path analysis were used as statistic techniques to analyze. The conclusions are the followings; First, The higher bodily, environmental, mental, informational, and physical security need the more body and property protection satisfaction and facility customer satisfaction. The higher bodily, environmental, and mental security need the more employee service satisfaction. Second, The higher bodily, environmental, informational, and physical security need are perceived, the more influence is marked with life satisfaction and security life satisfaction. Third, The higher personal and property protection, facility, and employee service satisfaction the more security life satisfaction. Also, the higher customer service and personal and property protection satisfaction are perceived, the more influence is marked with life satisfaction. Fourth, Security need sufficiency has little influence on life satisfaction directly, but it has high influences on life satisfaction through customer satisfaction of electronic security system.

• Journal of Digital Contents Society
• /
• v.15 no.1
• /
• pp.19-27
• /
• 2014

In order to estimate the life of 2,5 inch HDD which is adopted by PC environment, make the test plan which reflect the failure mode of market, make the test model of accelerated life test which reflect the stress of temperature. after an analysis of the environment of PC using, test procedure was decided that operation was write 50 % and read 50 %, and then access method was sequential 50 % and random 50%. The acceleration life test was executed on condition that temperature was $50^{\circ}C$ and $60^{\circ}C$, performance was 95 % in max performance, test time was 1000 hours. by the test of goodness of fit of anderson-darling of the failure data during test, it was confirmed that the distribution of failure fellow weibull. test for shape and scale was equal, and shape parameter was 0.7177, characteristic life was 429434 hours at normal user condition($30^{\circ}C$) by the analysis of weibull-arrhenius modeling. It made no difference about the statistics when equality test was executed. The activation energy was 0.2775eV. In analyzing between the failure samples of acceleration test and the samples of market return even though there is detail difference about the share of failure mode, the rank of share was almost same. This study suggest the test procedure of acceleration test of 2.5 inch HDD in PC using environment, and help the life estimation at manufacture and user.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2008.04a
• /
• pp.387-390
• /
• 2008

The importance of the life cycle cost analysis for construction projects of bridge has been recognized over the last decades. Accordingly, theoretical models, guidelines, and supporting softwares have been developed for the life cycle cost analysis of bridges. However, it is difficult to predict life cycle cost considering uncertainties precisely. This paper presents methodology for optimal design of substructure for a steel box bridge. Total life cycle cost for the service life is calculated as sum of initial cost, damage cost considering uncertainty, maintenance cost, repair and rehabilitation cost. The optimization method is applied to design of a bridge substructure with minimal cost, in which the objective function is set to life cycle cost and constraints are formulated on the basis of Korean Bridge Design Specification. Initial cost is calculated based on standard costs of the Korea Construction Price Index and damage cost on the damage probabilities to consider the uncertainty of load and resistance. An advanced first-order second moment method is used as a practical tool for reliability analysis using damage probability. Maintenance cost and cycle is determined by a stochastic method and user cost includes traffic operation costs and time delay costs.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.24 no.5 s.176
• /
• pp.1331-1342
• /
• 2000

In power generation systems a variety of structural components typically operate at high temperature and pressure. Therefore a life assessment methodology accounting for gradual creep fracture is increasingly needed for these components. The most critical defects in such structure are generally found in the form of semi-elliptical surface cracks in the welded tubular joints. Therefore the analysis of a semi-elliptical surface crack in a plate or a shell is an important problem in engineering fracture mechanics. On this background, via shell/line-spring finite element analyses of such surface cracks in the welded T and L joints under various loadings, we investigate J-integral along the crack front We first develop T and L joints auto mesh generation program providing ABAQUS input file composed of shell/line-spring finite elements. We then further develop a T and L joints life assessment program based on the experimental creep crack growth law and auto mesh generation program in a graphical user interface format Finally the remaining life of T and L joints for various analytical parameters are assessed using the developed life assessment program.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.25 no.2
• /
• pp.264-274
• /
• 2001

An integrated fatigue strength assessment system was computerized. The system developed consists of 9 modules: user interface, cycle counting, load history construction, data searching, fatigue properties estimation, fatigue data analysis, true stress and strain analysis, expert system for crack initiation life prediction, fatigue crack initiation and propagation life prediction. Fatigue strength database also was included in this system. The fatigue expert system helps a beginner to predict a fatigue crack initiation life in fatigue strength assessment. The expert system module in this system is developed on the personal computer by using C language and UNiK, an expert system developing tool. To evaluate the system, the results of test under variable loading of SAE and failure data from a field were analyzed. The evaluation show that the system provided fatigue life prediction within 3-scatter band and gave reasonable predictions. To get more accurate predictions of fatigue life without fatigue properties, we recommend utilizing the system along with the fatigue strength database.