• Journal of the Korea Convergence Society
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• v.12 no.11
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• pp.221-228
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• 2021

This study was conducted to improve the convenience of design of mobile VR devices use in a way binds smart phones. Research on traditional mobile VR devices is insufficient. So the first survey was conducted on users 100 to understand the current status and status of mobile VR devices. As a result, it was found that the satisfaction with the convenience of use was significantly lowered, and countermeasures were needed. Then, a second survey of 30 Heavy Users was conducted to find out specific usability and problems of mobile VR devices. Through this, problems, ease of use, and other opinions of mobile VR devices were found. The survey results were analyzed through the Descriptive Statistics Act, and it was found that improvement was urgent due to low satisfaction with wearing and network. In-depth interviews were conducted with the same respondents. As with the problems derived first, problems such as wearing satisfaction, excessive head weight for long-term use, and lack of content could be found. Based on the previous studies, the focus group interview consisting of 6 experts derived the ease of use evaluation element. It consists of elements that can satisfy the convenience of use of mobile VR devices for creation, wearing satisfaction, network, morphology, learning, and spatiality, and has a total of 26. Using this evaluation elements, it is intended to provide better ease of use to users who will use the mobile VR device.

• Journal of Practical Engineering Education
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• v.16 no.3_spc
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• pp.391-399
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• 2024

All highway toll gates in Korea use low-speed WIM(Weight-In-Motion) to block overloaded cargo vehicles from entering the main highway, but some cargo vehicle owners are illegally modifying vehicles to operate variable axles and evading crackdowns by manipulating the axles. In previous studies detect all tires of a running vehicle were detected to determine whether there is axle manipulation. However, because the vehicle entry area at the highway toll gate checkpoint is very narrow, there is a problem that it is realistically difficult to film all tires of the entering vehicle in one video frame. In this paper, we proposed a system that can determine whether the axle is being operated through changes in the height of the vehicle's cargo box rather than by detecting tires. To detect changes in the height of a cargo box, we propose a method to extract the representative line of the cargo box using Hough transform and then measure the change in height of the representative line to detect the change in height of the cargo box. In addition, we propose a method to detect changes in the vertical height of a cargo box by accumulating motion vectors of pixels within a certain area of the image using optical flow. And the two methods were compared and their advantages and disadvantages were analyzed and presented.

• Trans-
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• v.7
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• pp.103-121
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• 2019

In some documentary films, there are interviews, but in some other ones, there aren't any. As for the documentaries with interviews, the director uses talking heads to suggest their own arguments and to have audience agree. It is evident that interviews play a key role since they lead the story of a human-related documentary. Some directors prefer interviews where directors' questions and interviewees' answers are both heard. On the other hand, there a re directors who carry out the story just by using the answers from the interviewees. Then, it becomes crucial that we understand both of these styles and have new perspectives when watching documentary films. Ethics has always been considered one of the most important factors in documentaries and since they are believed to be "true," the influence documentaries have on the society is enormous. However, possibilities of exaggerating or manipulating the "truth" always exist. Therefore, it is important for the audience to identify the intentions of the director. As a matter of fact, there have been countless researches being done, but it is difficult to find studies that discuss the ways interviews are used in documentary films. The two different styles mentioned above do have huge differences in terms of directing methods. Thus, taking a look at differences from diverse angles will help us better understand the essentials of documentary films. This study will take examples from the interviews in Michael Moore's (2002), (2007) and observe how the flow of interviews can change when the voice of the director gets involved. There will also be a close examination of interviews in Kim Ilran and Hong Ji Yoo's (2011), and (2005) directed by Jim Butterworth, Aeron Lubarsky, and Lisa Sleeth, as well as Sebastian Junger and Tim Hetherington's (2010). By a careful review, use of dissolve, cross-cutting, and flashback will be analyzed to show how different editing techniques have an impact on subjective views of the director.

• Archives of design research
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• v.17 no.2
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• pp.95-104
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• 2004

Creativity is a important keyword for users as well as for main design organization who needs it. But little attention has been given to the aspect of user's creativity, also there has been a few attempt to apply it into design development until now. Nowadays in design areas, user's experiences and actions are changing the passive states receiving meanings into the active states creating meanings voluntarily. It is resonable to suppose that creative stage is important for users and they have the possibility of new ideas of uses and creating new productions. User's experiences of objects includes that of being formed or supported previously and that of voluntary interpretations acquired for himself, which it may be the possibilities predicted in design process or unknown user's action areas. It is likely that creative use process by themselves are the actions applied and deviated from usability and function by main design organization, also creative productions are arranged and made by users. These have a scope of examination and research in probability that is occurs frequently in user. In this research, approaching with a term, 'User gestures', User gestures are the characteristic action areas based on user's voluntary behaviors, where are revealed a unessential and non-operational function as a action itself and various transformation and creation of products as a outcome of action. This fact proves clearly that user gestures have a worth of alive spectrum to observe aspects of user culture and could be a attractive approach to seek easily new design concept for designer and developer. A further direction of this study will be following areas, Ethnography methods research of user gestures, Cultural research to phenomenon of user design and UGSBD(User gesture scenario based design) research. And it seems probable that they are applied in design development as follows, User initiative customization products, User participatory recycling products and creativity-experience design.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.1
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• pp.32-36
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• 2016

Purpose In nuclear medicine examination, $^{131}I$ is widely used in nuclear medicine examination such as diagnosis, treatment, and others of thyroid cancer and other diseases. $^{131}I$ conducts examination and treatment through emission of ${\gamma}$ ray and ${\beta}^-$ ray. Since $^{131}I$ (364 keV) contains more energy compared to $^{99m}Tc$ (140 keV) although it displays high integrated rate and enables quick discharge through kidney, the objective of this study lies in comparing the difference in exposure dose of $^{131}I$ before and after wearing apron when handling $^{131}I$ with focus on 3 elements of external exposure protection that are distance, time, and shield in order to reduce the exposure to technicians in comparison with $^{99m}Tc$ during the handling and administration process. When wearing apron (in general, Pb 0.5 mm), $^{99m}Tc$ presents shield of over 90% but shielding effect of $^{131}I$ is relatively low as it is of high energy and there may be even more exposure due to influence of scattered ray (secondary) and bremsstrahlung in case of high dose. However, there is no special report or guideline for low dose (74 MBq) high energy thus quantitative analysis on exposure dose of technicians will be conducted based on apron wearing during the handling of $^{131}I$. Materials and Methods With patients who visited Department of Nuclear Medicine of our hospital for low dose $^{131}I$ administration for thyroid cancer and diagnosis for 7 months from Jun 2014 to Dec 2014 as its subject, total 6 pieces of TLD was attached to interior and exterior of apron placed on thyroid, chest, and testicle from preparation to administration. Then, radiation exposure dose from $^{131}I$ examination to administration was measured. Total procedure time was set as within 5 min per person including 3 min of explanation, 1 min of distribution, and 1 min of administration. In regards to TLD location selection, chest at which exposure dose is generally measured and thyroid and testicle with high sensitivity were selected. For preparation, 74 MBq of $^{131}I$ shall be distributed with the use of $2m{\ell}$ syringe and then it shall be distributed after making it into dose of $2m{\ell}$ though dilution with normal saline. When distributing $^{131}I$ and administering it to the patient, $100m{\ell}$ of water shall be put into a cup, distributed $^{131}I$ shall be diluted, and then oral administration to patients shall be conducted with the distance of 1m from the patient. The process of withdrawing $2m{\ell}$ syringe and cup used for oral administration was conducted while wearing apron and TLD. Apron and TLD were stored at storage room without influence of radiation exposure and the exposure dose was measured with request to Seoul Radiology Services. Results With the result of monthly accumulated exposure dose of TLD worn inside and outside of apron placed on thyroid, chest, and testicle during low dose $^{131}I$ examination during the research period divided by number of people, statistics processing was conducted with Wilcoxon Signed Rank Test using SPSS Version. 12.0K. As a result, it was revealed that there was no significant difference since all of thyroid (p = 0.345), chest (p = 0.686), and testicle (p = 0.715) were presented to be p > 0.05. Also, when converting the change in total exposure dose during research period into percentage, it was revealed to be -23.5%, -8.3%, and 19.0% for thyroid, chest, and testicle respectively. Conclusion As a result of conducting Wilcoxon Signed Rank Test, it was revealed that there is no statistically significant difference (p > 0.05). Also, in case of calculating shielding rate with accumulate exposure dose during 7 months, it was revealed that there is irregular change in exposure dose for inside and outside of apron. Although the degree of change seems to be high when it is expressed in percentage, it cannot be considered a big change since the unit of accumulated exposure dose is in decimal points. Therefore, regardless of wearing apron during high energy low dose $^{131}I$ administration, placing certain distance and terminating the administration as soon as possible would be of great assistance in reducing the exposure dose. Although this study restricted $^{131}I$ administration time to be within 5 min per person and distance for oral administration to be 1m, there was a shortcoming to acquire accurate result as there was insufficient number of N for statistics and it could be processed only through non-parametric method. Also, exposure dose per person during lose dose $^{131}I$ administration was measured with accumulated exposure dose using TLD rather than through direct-reading exposure dose thus more accurate result could be acquired when measurement is conducted using electronic dosimeter and pocket dosimeter.

• Investigative Magnetic Resonance Imaging
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• v.18 no.2
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• pp.120-132
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• 2014

Purpose : To compare dynamic susceptibility contrast imaging, diffusion-weighted imaging, and susceptibility-weighted imaging (SWI) for the differentiation of tumor recurrence and delayed radiation therapy (RT)-related changes in patients treated with RT for primary brain tumors. Materials and Methods: We enrolled 24 patients treated with RT for various primary brain tumors, who showed newly appearing enhancing lesions more than one year after completion of RT on follow-up MRI. The enhancing-lesions were confirmed as recurrences (n=14) or RT-changes (n=10). We calculated the mean values of normalized cerebral blood volume (nCBV), apparent diffusion coefficient (ADC), and proportion of dark signal intensity on SWI (proSWI) for the enhancing-lesions. All the values between the two groups were compared using t-test. A multivariable logistic regression model was used to determine the best predictor of differential diagnosis. The cutoff value of the best predictor obtained from receiver-operating characteristic curve analysis was applied to calculate the sensitivity, specificity, and accuracy for the diagnosis. Results: The mean nCBV value was significantly higher in the recurrence group than in the RT-change group (P=.004), and the mean proSWI was significantly lower in the recurrence group (P<.001). However, no significant difference was observed in the mean ADC values between the two groups. A multivariable logistic regression analysis showed that proSWI was the only independent variable for the differentiation; the sensitivity, specificity, and accuracy were 78.6% (11 of 14), 100% (10 of 10), and 87.5% (21 of 24), respectively. Conclusion: The proSWI was the most promising parameter for the differentiation of newly developed enhancing-lesions more than one year after RT completion in brain tumor patients.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.2
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• pp.127-138
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• 2000

To enable rapid and convenient soil test, new soil analytical methods, which require only one instrument, UV/Vis spectrophotometer, were developed and named "Soiltek KA-P spectrophotometric methods". The Soiltek$^{(R)}$ KA-P spectrophotometric method was compared with standard method of RDA in analytical capability for soil chemical properties. Using the 78 soils collected from upland, paddy, orchard, and vinyl house soils, soil organic matter, exchangeable K, Ca, and Mg. CEC, available $SiO_2$, and nitrate were analyzed by the two methods. The color stability(ratio of the absorbance at elapsed time t to the absorbance at time t=0) of organic matter. Ca, Mg, and available $SiO_2$ decreased to about 2% within one hour. However, that of exchangeable K, CEC, and nitrate remained constant. The results obtained with Soiltek$^{(R)}$ KA-P spectrophotometric method showed highly significant correlation with those measured by the standard method of RDA($R^2$ >0.9501), in which the slopes were near unity of $1.0{\pm}0.05$. The standard deviation values of organic matter, exchangeable K, Ca, and Mg, CEC, available $SiO_2$, and nitrate were apparently lower than ${\pm}1.8gkg^{-1}$, ${\pm}0.05cmol^+kg^{-1}$, ${\pm}0.18cmol^+kg^{-1}$, and ${\pm}0.13cmol^+kg^{-1}$, ${\pm}1.0cmol^+kg^{-1}$, ${\pm}5.0mgkg^{-1}$, and ${\pm}10.0mgkg^{-1}$, respectively. All the measurements showed coefficients of variation of less than 7~17% and were within the confidence level of 95%, which means both the methods are precise. Considering the relative simplicity, low cost, precision and accuracy, the proposed Soiltek$^{(R)}$ KA-P spectrophotometric methods could be recommended as an alternative to standard method.

• Journal of The Korean Association For Science Education
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• v.33 no.5
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• pp.893-910
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• 2013

The purpose of this study was to identify changes in mental models of students in the elementary school about causes of seasonal changes. During a total of eight sessions, eight sixth graders were asked to describe the causes of seasonal changes through pictures, writing and thinking aloud by using microgenetic research methods, and the changes in mental models were examined. When the research was conducted, linguistic and behavioral factors and contents of interviews of participants were recorded on video. Moreover, a variety of materials such as field observation chart were written by a researcher and mental models records were written by a student. The protocol was written by integration of collected results, and it was repeated to read and was inductively categorized. The results of this study were as follows: First, participants' mental models about causes of seasonal changes were changed in various paths within and across sessions. Participants' mental models that had been more changed in various ways were closer to the scientific model. In addition, like rotation and revolution, students who correctly established the preconceptions related to seasonal changes formed the mental models consistent with scientific concept based on new information. On the other hand, students who did not correctly establish the preconceptions did not deviate from non-scientific mental models. Second, prior knowledge, experience and information which participants held in advance, accuracy of prior knowledge, resolution of inconsistency between new knowledge and existing mental models, activation of mental models through operation of models and drawing an picture affected the changes of mental models. Teachers should provide to learners with sufficient experience which can be configured to various mental models in order to form the scientific concepts. And they need to let learners feel the doubt and resolve it through presentation of new teaching material which is inconsistent with the existing mental models.

• Journal of The Korean Association For Science Education
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• v.37 no.2
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• pp.359-370
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• 2017

The purpose of this study is to explore the changes caused by using smart technology in school science inquiry. For this, we investigated 12 elementary school teachers' perceptions by using an open-ended questionnaire, group discussions, classroom discussions, and participant interviews. The results of this study indicate that the introduction of technology into classroom inquiry can open up the various possibilities and can cause additional burdens as well. First, teachers explained that smart technology can expand the opportunities to observe natural phenomena such as constellations and changing phases of the moon. However, some teachers insisted that, sometimes, learning how to use new devices disrupts students' concentration on the inquiry process itself. Second, teachers introduced the way of digital measurement using smart phone sensors in inquiry activities. They said that digital measurement is useful in terms of the reduction of errors and of the simplicity to measure. However, other teachers insisted that using new devices in classroom inquiry can entail additional variables and confuse the students' focus of inquiry. Communication about inquiry process can also be improved by using digital media. However, some teachers emphasized that they always talked about both the purpose of using SNS and online etiquettes with their students before using SNS. Based on these results, we discussed the necessity of additional analysis on the various ways of using digital devices depending on teachers' perceptions, the types of digital competency required in science inquiry using smart technology, and the features of norms shaped in inquiry activities using smart technology.

• Korean Journal of Cognitive Science
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• v.27 no.3
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• pp.441-467
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• 2016

This fMRI study is aim to investigate effects of competitive environment in cognitive empathic process in human brain. Empathy is known as a crucial factor for human's adaptive behavior in aspects of social cognition and it is almost automatic process, on the other hand competitive situation is psychologically devastated environment to win someone for getting rewards. We hypnotized that reading and understanding of other person's mind are a specific characteristic related to survival evolutionarily, however competition would have an effect on the empathic cognitive process because of mechanisms of competition. To manipulate the competitive atmosphere, one researcher took a role of competitor against participants and they were instructed to get monetary rewards when their performance was better than a competitor. 21 participants(9 males and 12 females) performed to judge the emotional valence of the empathic task consisted of illustrated images with various situation could be experienced in real world as on $1^{st}$ person perspective in both competitive and non-competitive condition, and did same performance with objects stimulus in control condition. In order to examine the competition effects on empathic process,, hemodynamic response were obtained during fMRI session and the imaging data were analyzed to identify brain regions where responses to each condition across the two consecutive runs. Participants' reaction time in competitive condition was faster statistically significant than non-competitive one. Activation for competitive condition increased in the following areas: ACC, mPFC, SMG, thalamus extended caudate and Nacc, parahippocampal gyrus, and for non-competitive condition increased paracingulate gyrus, temporal pole, vmPFC, superior occipital gyrus. As a result of regression analysis using empathic scores as covariance, the rSMG, IFG, fusiform gyrus, thalamus, putamen were correlated with higher empathic levels, and TPJ were correlated with lower empathic scores. We suggest that these observations could mean competitive environment have an effect on neural base of cognitive empathic process.