• Journal of the Ergonomics Society of Korea
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• v.26 no.2
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• pp.15-20
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• 2007

The purpose of this study is to compare assessment techniques for Korean characters entry methods of mobile phones. This study was performed based on survey of relevant existing studies. The assessment techniques were classified into three: 1) predicting entry time using conceptual models such as Fitts' law, Hick-Hyman's law and KLM-GOMS model (conceptual model); 2) counting the number of pressing button(number of pressing button); and 3) measuring performance or rating subjective measures using real mobile phones(real mobile phone). The comparison revealed that the assessment results were different depending upon the techniques used. The results from the conceptual model using only Fitts' law and the number of pressing button were opposite to those from techniques of the real mobile phone and conceptual model using Fitts' and Hick-Hyman's laws. Based on this result and suggestions provided by the literature, it is recommended that for more precisely assessing interfaces of mobile phones such as Korean characters entry method, real mobile phones be used instead of the conceptual models.

• The Journal of the Korea Contents Association
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• v.15 no.2
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• pp.58-73
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• 2015

In the IoT environment, context information is important to provide context service to the user. For this, collected data from devices such as sensors or actuators, converts to context information using the ontology. Because the existing ontologies designed for target service, if the user wants to change the service requirements, service condition, service environment or another service, overall ontology will be redesigned to the changed service. To overcome this difficulty, we propose the cross-vertical ontology model called the Generic Ontology Models(GOMs). It can define the user's desired services without regarding to place and situation. Also, we propose IoT service concept model that represents data flow of the IoT service and IoT service environment. Moreover, as the use case, we show that the proposed GOMs are able to provide the IoT service well.

• Journal of Information Technology Services
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• v.11 no.4
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• pp.181-194
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• 2012

The one of the most meaningful change in the recent ubiquitous environment is the omnipresence of public digital display device for providing ubiquitous information. It is the important issue to provide publicity as well as adaptive information to each user in the field of the public digital display device. This research proposes the idea ensuring fast response speed by the selection of user preference function. The preference function is selected by statistics using Zipf distribution in the system comprising mobile device and digital display device based on NFC (Near Field Communication). The idea is proved by CPM-GOMS model and the improvement of user response can be achieved.

• Journal of the Ergonomics Society of Korea
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• v.29 no.4
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• pp.661-665
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• 2010

Current subway station's office employee must perform safety management tasks by monitoring the various safety management systems. But these monitoring systems are limited in effective situational awareness and response to a state of emergency immediately. It is necessary to develop an integrated safety management system display. In this study, we developed subway station safety management system's (CCTV, fire detection & alarm system, screen door control equipment) integrated prototype display with ecological interface design framework and evaluated prototype display interface's usability with GOMS model. The result was that the ecological interface's performance was better than existing safety management system's interface.

• Journal of the Ergonomics Society of Korea
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• v.35 no.4
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• pp.277-291
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• 2016

Objective: The aim of this study is to propose a unit touch gesture model, which would be useful to predict the performance time on mobile devices. Background: When estimating usability based on Model-based Evaluation (MBE) in interfaces, the GOMS model measured 'operators' to predict the execution time in the desktop environment. Therefore, this study used the concept of operator in GOMS for touch gestures. Since the touch gestures are comprised of possible unit touch gestures, these unit touch gestures can predict to performance time with unit touch gestures on mobile devices. Method: In order to extract unit touch gestures, manual movements of subjects were recorded in the 120 fps with pixel coordinates. Touch gestures are classified with 'out of range', 'registration', 'continuation' and 'termination' of gesture. Results: As a results, six unit touch gestures were extracted, which are hold down (H), Release (R), Slip (S), Curved-stroke (Cs), Path-stroke (Ps) and Out of range (Or). The movement time predicted by the unit touch gesture model is not significantly different from the participants' execution time. The measured six unit touch gestures can predict movement time of undefined touch gestures like user-defined gestures. Conclusion: In conclusion, touch gestures could be subdivided into six unit touch gestures. Six unit touch gestures can explain almost all the current touch gestures including user-defined gestures. So, this model provided in this study has a high predictive power. The model presented in the study could be utilized to predict the performance time of touch gestures. Application: The unit touch gestures could be simply added up to predict the performance time without measuring the performance time of a new gesture.

• Journal of Korea Society of Digital Industry and Information Management
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• v.19 no.3
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• pp.177-192
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• 2023

The employment rate of university graduates has been decreasing significantly recently. With the advent of the Fourth Industrial Revolution, the demand for software employment has increased. It is necessary to analyze the factors for software employment of university graduates. This paper proposes explainable software employment model of university graduates using machine learning and explainable AI. The Graduates Occupational Mobility Survey(GOMS) provided by the Korea Employment Information Service is used. The employment model uses boosting machine learning. Then, performance evaluation is performed with four algorithms of boosting model. Moreover, it explains the factors affecting the employment using SHAP. The results indicates that the top 3 factors are major, employment goal setting semester, and vocational education and training.

• The Korean Journal of Applied Statistics
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• v.25 no.6
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• pp.959-975
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• 2012

Each year research institutions such as the Korea Employment Information Service(KEIS), a government institution established for the advancement of employment support services, and Job Korea, a popular Korean job website, announce first job waiting times after college graduation. This provides useful information understand and resolve youth unemployment problems. However, previous reports deal with the time as a completely observed one and are not appropriate. This paper proposes a new study on first job waiting times after college graduation set to 4 months prior to graduation. In Korea, most college students hunt for jobs before college graduation in addition, the full-fledged job markets also open before graduation. In this case the exact waiting time of college graduates can be right-censored. We apply a Cox proportional hazards model to evaluate the associations between first job waiting times and risk factors. A real example is based on the 2008 Graduates Occupational Mobility Survey(GOMS).

• Korean Journal of Computational Design and Engineering
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• v.11 no.6
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• pp.403-411
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• 2006

NURBS surfaces have been widely used in engineering design since it can create a smooth surface using minimal numbers of data. But deformation of the surfaces is quite difficult especially for the detailed modification. Also, NURBS surface deformation processes need many inputs, and it is not easy to be implemented in 3D virtual system. In this paper, both the surface trimming and multi-resolution surface are used for the detailed sculpting including sharp edges of NURBS surface. QuadTree is used to separate cleanly the target surface with the surface for sculpting effect. Simple user strokes are also used for the sculpting target curves and GOMS(Goals, Operators, Methods, Selection Rules) model is applied to verify the efficiency of the proposed sculpting process.

• Management & Information Systems Review
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• v.29 no.4
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• pp.245-266
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• 2010

So far the study on college graduates has been concentrated on employment and wages. But if college graduates get a job, this study want expanding to the study of the suitability of their level to the job or the job satisfaction. For this study, structural equation model was built up to verify the influencing factors on the job suitability and job satisfaction of college graduates by using data of '2007 Graduates Occupational Mobility Survey(GOMS)'. To put it concretely, job suitability and job satisfaction were analysed based on the leading factors such as vocational value of graduates and the participation of employment supporting program in university. Analyses showed that the vocational value has a positive influence on the job suitability and the job satisfaction as well as the participation of employment support program. And the participation of employment supporting program influenced positively on the job satisfaction and the job suitability while in work. Besides we found that the job suitability has a positive impact on the job satisfaction. These confirmed that the vocational value while in school is very important and plays an important role in the job suitability and the job satisfaction with their jobs while in work. Also those who have a higher vocational value take part in the various employment supporting programs and experience the job satisfaction and the job suitability while in work. Therefore we found that the various employment supporting programs play an important role for the graduates. Accordingly, the school authorities and job centers have to strengthen the value education for the enrolled student to plant a vocational value and improve and reinforce the employment supporting program in university.

• Journal of the Ergonomics Society of Korea
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• v.29 no.6
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• pp.907-914
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• 2010

Cognitive model, that is cognitive architecture, is the model expressed with computer program to show the process how human solve a certain problem and it is continuously under investigation through various fields of study such as cognitive engineering, computer engineering, and cognitive psychology. In addition, the much extensive applicability of cognitive model usually helps it to be used for quantitative prediction of human Behavior or Natural programming of human performance in many HCI areas including User Interface Usability, artificial intelligence, natural programming language and also Robot engineering. Meanwhile, when a system designed, an usability test about conceptual design of interface is needed and in this case, analysis evaluation using cognitive model like GOMS or ACT-R is much more effective than empirical evaluation which naturally needs products and subjects. In particular, if we consider the recent trend of very short-end term between a previous technology development and the next new one, it would take time and much efforts to choose subjects and train them in order to conduct usability test which is repeatedly followed in the process of a system development and this finally would bring delays of development of a new system. In this study, we predicted quantitatively the human behavior processes which contains cognitive processes for menu selection in touch screen interface through ACT-R, one of the common method of usability test. Throughout the study, it was shown that the result using cognitive model was equal with the result using existing empirical evaluation. And it is expected that cognitive model has a possibility not only to be used as an effective methodology for evaluation of HCI products or system but also to contribute the activation of HCI cognitive modeling in Korea.