• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.2
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• pp.184-191
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• 2017

This paper presents cluster based hybrid spectrum sensing system for M2M services. For each cluster, secondary nodes within the transmission radius of the primary node use hard decision method through local spectrum sensing to determine whether the primary node exists. And the other secondary nodes and the secondary nodes having poor radio channel conditions judge the existence of the primary node through the soft decision method of the values obtained by performing the cooperative spectrum sensing. In the proposed hybrid spectrum sensing system, the performance according to the number of secondary nodes is analyzed with the conventional system over Rayleigh fading channel. As the number of cooperative sensing users increased to 2, 3 and 4, the cluster error probability decreased to 0.5608, 0.5252 and 0.4001 at SNR of -10[dB] respectively. Since the proposed system uses less overhead traffic, it is found that it is more effective in terms of frequency usage than the conventional system using soft decision-soft decision and soft decision-hard decision methods.

• Science of Emotion and Sensibility
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• v.17 no.3
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• pp.83-94
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• 2014

The present study examined the intensity of affective forecasting and the size of affective forecasting errors of people who experienced social exclusion or those high in need to belong. In Particular, a series of studies was designed to explore the moderating role of the types of future events (i.e. social vs. non-social events) in the relationship between social exclusion, the need to belong and affective forecasting. Results indicated that participants who experienced social exclusion or be high in need to belong showed significantly extreme affective ratings on the future social events compared to the future non-social events. Additional results suggested that more social exclusion experiences or higher needs to belong did not affect to the affective ratings on the experienced social events, indicating greater affective forecasting errors of socially excluded people or people with higher need to belong. The implications and limitations of the results were also discussed.

• 재활복지
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• v.20 no.4
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• pp.229-246
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• 2016

The aim of this study is to conduct superordinate word selection task to compare their performance and reaction time, and superordinate word writing task to compare the differences in their performance and error pattern in 40 elderly adults and 43 young adults. As a result, first, in both tasks, elderly adults had a smaller number of correct responses. Second, elderly adults showed slower reaction time than young adults. Third, in superordinate word writing task, elderly adults showed more relevant errors than irrelevant errors. The reason elderly adults had a smaller number of correct responses in both tasks was that the links among the pieces of information in the semantic lexicon weakened or deteriorated due to normal aging. Slower reaction time was based on neurophysiological changes of the brain and cognitive processing speed. In addition, the relevant errors showed that they could access the lexicon for target words and produce explanation the relevant characteristics, even though they could not retrieve the target words.

• Journal of the Korean Society of Safety
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• v.37 no.3
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• pp.52-59
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• 2022

Conventionally, all the unsafe acts by human beings in relation to industrial accidents have been regarded as unintentional human errors. Exceptionally, however, in the cases with fatalities, seriously injured workers, and/or losses that evoked social issues, attention was paid to violating related laws and regulations for finding out some people to be prosecuted and given judicial punishments. As Heinrich stated, injury or loss in an accident is quite a random variable, so it can be unfair to utilize it as a criterion for prosecution or punishment. The present study was conducted to comprehend how categorizing intentional violations in unsafe acts might disrupt conventional conclusions about the industrial accident process. It was also intended to seek out the right direction for countermeasures by examining unsafe acts comprehensively rather than limiting the analysis to human errors only. In an analysis of 150 industrial accident cases that caused fatalities and featured relatively clear accident scenarios, the results showed that only 36.0% (54 cases) of the workers recognized the situation they confronted as risky, out of which 29.6% (16 cases) thought of the risk as trivial. In addition, even when the risks were recognized, most workers attempted to solve the hazardous situations in ways that violated rules or regulations. If analyzed with a focus on human errors, accidents can be attributed to personal deviations. However, if considered with an emphasis on safety rules or regulations, the focus will naturally move to the question of whether the workers intentionally violated them or not. As a consequence, failure of managerial efforts may be highlighted. Therefore, it was concluded that management should consider unsafe acts comprehensively, with violations included in principle, during accident investigations and the development of countermeasures to prevent future accidents.

• Journal of Korea Society of Industrial Information Systems
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• v.28 no.2
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• pp.61-75
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• 2023

This study aims to evaluate the usability of a banking app that is frequently used by the elderly. To this end, the usability PACMAD(People At the Center of Mobile Application Development) model that can be used in mobile was explained and the usability evaluation was empirically verified for the elderly over 60 years of age. For this study, descriptive statistics and variance analysis were conducted using SPSS 25.0 for 165 elderly people who had experience using banking apps. Looking at the analysis results of this study, efficiency, satisfaction, and effectiveness showed relatively high scores, and learnability, memorability, error, and cognitive load showed relatively low scores. In addition, in the verification of differences by age, it was confirmed that there were differences in all variables by age. These results suggest that the elderly's usability evaluation of banking apps and differences by age could be confirmed, but there is also a limitation that comparison with the general public is difficult because the age is limited to the elderly.

• Korean Journal of Culture and Social Issue
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• v.12 no.4
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• pp.77-99
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• 2006

The purpose of this study was to find out the effects of auto-mobile tinting upon driver's cognitive responses and behaviors through two laboratory experiments, a field experiment and a traffic accident data. The results of two laboratory experiments showed that there were higher false alarm responses under the conditions of 65%, 50%, 35% tinting level than thoses under the 100% level condition. It was also shown that the drivers who had bad sight made more missing responses than the drivers who had normal vision. The main results of the laboratory experiment were repliceted through both the field experiment and the survey research of car accidents. The results of this study were discussed in terms of the previous studies performed abroad. We strongly suggested 70% tinting level as a regulation standard for safe driving and the strategies for implementing the regulation rule.

• Journal of The Korean Association For Science Education
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• v.28 no.6
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• pp.675-684
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• 2008

This study investigated the effects of the prescribed instructional strategy for reducing students' connecting errors in learning chemistry concepts with multiple external representations by students' field independence-dependence. Seventh graders (N=126) at a coed middle school were assigned to control and treatment groups. The students learned "Boyle's Law" and "Charles's Law" for two class periods. Results revealed that the students in the treatment group scored significantly higher than those in the control group in a conception test. The scores of the treatment group were significantly higher than those of the control group in a motivational learning test, especially in 'attention' of the test. However, there was no significant interaction between the instruction and students' field independence-dependence in the two tests. Most students in the treatment group perceived the instruction positively in cognitive and motivational aspects.

• Korean Journal of Cognitive Science
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• v.19 no.4
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• pp.331-367
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• 2008

This study aims to validate a web-based neuropsychological testing tool developed by Kwak(2007) and to suggest solutions to potential problems that can deteriorate its validity. When it targets a wider range of subjects, a web-based neuropsychological testing tool is challenged by high drop-out rates, lack of motivation, lack of interactivity with the experimenter, fear of computer, etc. As a possible solution to these threats, this study aims to redesign the user interface of a web-based attention testing tool through three phases of study. In Study 1, an extensive analysis of Kwak's(2007) attention testing tool was conducted to identify potential usability problems. The Heuristic Walkthrough(HW) method was used by three usability experts to review various design features. As a result, many problems were found throughout the tool. The findings concluded that the design of instructions, user information survey forms, task screen, results screen, etc. did not conform to the needs of users and their tasks. In Study 2, 11 guidelines for the design of web-based attention testing tools were established based on the findings from Study 1. The guidelines were used to optimize the design and organization of the tool so that it fits to the user and task needs. The resulting new design alternative was then implemented as a working prototype using the JAVA programming language. In Study 3, a comparative study was conducted to demonstrate the excellence of the new design of attention testing tool(named graphic style tool) over the existing design(named text style tool). A total of 60 subjects participated in user testing sessions where their error frequency, error patterns, and subjective satisfaction were measured through performance observation and questionnaires. Through the task performance measurement, a number of user errors in various types were observed in the existing text style tool. The questionnaire results were also in support of the new graphic style tool, users rated the new graphic style tool higher than the existing text style tool in terms of overall satisfaction, screen design, terms and system information, ease of learning, and system performance.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.26 no.4
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• pp.283-304
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• 2015

The purpose of this study was to identify Web accessibility issues of healthcare websites of the Korean government and public agencies by evaluating these websites' accessibility in accordance with the Korean Web Contents Accessibility Guideline. This study conducted both automated and expert testing to assess the accessibility of a total of 27 health-related websites. The results of the assessment which was conducted in two stages indicated that institutions such as the National Hospital and National Rehabilitation Center demonstrated almost no Web accessibility error. In addition, the Korea Health Insurance Review and Assessment Service, the Ministry of Health and Welfare, the Health Services Agency, the Ministry of Food and Drug Safety, and the Korea Medical Dispute Mediation and Arbitration Agency attained very high web accessibility. However, the results of an expert evaluation highlighted that there were considerable errors in providing appropriate alternative text, which was not found in the automated test, and the color contrast of the text content did not comply with Web accessibility standard. Therefore, these websites did not support web accessibility for the sight-impaired. Furthermore, the present study found that it was difficult to deliver accurate information to users due to errors in the default language display and markup, and also, issues of skipping repeated content, content linearization, and compliance with keyboard use were considered as challenges that might arise for people with sight, cognitive and mobility impairments with respect to Web accessibility. It is the first study that evaluated accessibility of healthcare websites of the Korean government and public agencies based on the Korean Web Contents Accessibility Guideline. The present study made a contribution to research on Web accessibility by conducting expert testing, which provided a more complete assessment that identified the degree and specific issues of accessibility errors when compared to automated testing.

• Journal of the Korean Chemical Society
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• v.55 no.3
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• pp.509-518
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• 2011

In this study, we investigated the effects of analogy-generating in small group in elementary science-gifted education upon the types and the mapping errors of student-generated analogies, and the perceptions of the instruction. Fifth graders (N=37) at two science-gifted classes in two elementary schools were selected and assigned to individualistic analogygenerating (IA, n=19) and pair analogy-generating (PA, n=18) groups. After the students of each group performed the experiment and were taught about 'saturated solution' concept in the first class, they administered the test on the self-generating analogies on the concept in the second class. The students in the PA group also administered the test on perceptions of analogy-generating in small group and some of them were interviewed deeply. The results revealed that the students in the PA group made more verbal/pictorial, structural/functional, enriched, and higher systematic analogies than those in the IA group. However, there were little difference between the two groups in the subcategories of artificiality (artificial and everyday) and abstraction (abstract and concrete). The students in the PA group fewer mapping errors than those in the IA group. Many students in PA group perceived the analogy-generating in small group positively upon various cognitive and motivational aspects. However, they also pointed a few disadvantages of the activity. Educational implications of these findings are discussed.