• Journal of Practical Engineering Education
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• v.14 no.3
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• pp.479-489
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• 2022

In order to understand how to increase the use of virtual training content at K University's online lifelong education institute, this study examined the use experience, content recognition, field practice replacement, and requirements, focusing on the examples of operating institutions. To this end, 12 institutions that operated virtual training contents distributed by the K University Online Lifelong Education Center in 2020 were selected for in-depth interviews and qualitative analysis was conducted on the interviews of 11 institutions. As a result of the analysis, first, the experience of using the contents of the virtual training operating institution was aimed at changing the educational environment, supplementing theoretical learning, and improving the sense of practice. Second, according to a survey on the recognition of virtual training content, if the importance and utilization of the content are high, it can be replaced by on-site practice in non-face-to-face classes, such as experiences of facilities and equipment, attracting interest and attention. Third, in many cases, the perception of replacement for field practice is not unreasonable to use as a pre-training material for field practice, but it is difficult to replace field practice. Fourth, content quality improvements can be summarized as content quality improvement, content access and manipulation improvement, dedicated device development, training for instructors, and curriculum systematization. Fifth, institutional requirements include improving the quality of virtual training content itself, equipment support, curriculum systemization and characterization, systematic curriculum and detailed content sharing, detailed guidance on using virtual training content, introducing how to use content, and recruiting instructors. This study is meaningful in that it sought ways to improve the utilization of virtual training content based on the perception of virtual training content operating institutions.

• Journal of Intelligence and Information Systems
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• v.29 no.4
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• pp.325-345
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• 2023

In the rapidly evolving domain of e-commerce, our study presents a cohesive approach to enhance customer satisfaction prediction from online reviews, aligning methodological innovation with practical insights. We integrate the RFE-SHAP feature selection with LDA topic modeling to streamline predictive analytics in e-commerce. This integration facilitates the identification of key features-specifically, narrowing down from an initial set of 28 to an optimal subset of 14 features for the Random Forest algorithm. Our approach strategically mitigates the common issue of overfitting in models with an excess of features, leading to an improved accuracy rate of 84% in our Random Forest model. Central to our analysis is the understanding that certain aspects in review content, such as quality, fit, and durability, play a pivotal role in influencing customer satisfaction, especially in the clothing sector. We delve into explaining how each of these selected features impacts customer satisfaction, providing a comprehensive view of the elements most appreciated by customers. Our research makes significant contributions in two key areas. First, it enhances predictive modeling within the realm of e-commerce analytics by introducing a streamlined, feature-centric approach. This refinement in methodology not only bolsters the accuracy of customer satisfaction predictions but also sets a new standard for handling feature selection in predictive models. Second, the study provides actionable insights for e-commerce platforms, especially those in the clothing sector. By highlighting which aspects of customer reviews-like quality, fit, and durability-most influence satisfaction, we offer a strategic direction for businesses to tailor their products and services.

• Journal of The Korean Association For Science Education
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• v.29 no.8
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• pp.874-885
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• 2009

The purpose of this study is to analyze illustrations, contents, and experiments in 6 kinds of science textbook from the 9th grade covering the phases of the Moon (on the phases of the Moon in six 9th grade science textbook) and to suggest coherent and effective contents and frame of the science textbook. Hence, the researcher decided the study problem. The study problems are as follows; 'Are the illustrations in the science textbook presented to help understand the phases of the Moon depending on the position of the observer?', 'Does the contents of the book clearly mention the phases of the Moon?', 'Can students understand the phases of the Moon through the experiments in the science textbook?', 'Do illustrations, contents, and experiment of the science textbook consistently explain the phases of the Moon?'. 10 persons (9graduate students including the researcher) took part in this study. All things unanimously agreed upon by all participants were reflected in the results. The results are as follows: First, the universal observer's view point is mixed with the earth observer's view in the illustration of these science textbook regarding the phases of the Moon. Moreover, illustrations of some textbooks are presented with such words as 'sunrise', 'midnight' and consequently contain too much. Second, the contents of the science textbook concerning the phases of the Moon is not described clearly. In addition, they don't give clear and detailed explanations for the reason of these changes. Third, all of the textbooks, except one textbook, describe the experiment regarding the phases of the Moon with the earth observer's view point but don't specifically mention that the view point is that of the earth observer's view point. Fourth, illustrations, contents, and experiments in the science textbook don't coherently explain the phases of the Moon. In addition, it is confirmed through the process of the result analysis that the described contents in the science curriculum is not well constructed or logical.

• Journal of Preventive Medicine and Public Health
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• v.32 no.1
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• pp.48-59
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• 1999

Objectives. This study was conducted to evaluate the association between upper extremity musculoskeletal symptoms and Rapid Upper Limb Assessment(RULA) in vehicle assembly line workers. The goal of this study is to show the feasibility of RULA as a checklist for work related musculoskeletal symptoms (WMSDs) in Korean workers. Methods. The total number of 199 people from the department of assembly and 115 people from the department of Quality Control(QC) in automotive plant were subjects for this cross sectional study. A standard symptom questionnaire survey has been used for the individual characteristics, work history, musculosketal symptoms and non-occupational covariates. The data were obtained by applying one-on-one interview for the all subjects. RULA has been applied for ergonomic work posture analysis and the primary ergonomic risk sure was computed by RULA method. Association between upper extremity musculoskeletal symptoms and RULA were assessed by multiple logistic regression analysis. Results. A total of 314 workers was examined. The prevalence of musculoskeletal symptoms by NIOSH case definition was 62.4%. The distribution of musculoskeletal symptoms by the part of the body turned out to be following; back:41.4%, neck: 32.8%, shoulder: 26.4%, arm: 10.5% and hand:29.3%. The relationship of the individual RULA scores were statistically significant for the prevalence of musculoskeletal symptoms. As the result of the multiple logistic regressioin analysis, grand final score (OR=2.250 95% CI: 1.402-3.612) was associated with musculoskeletal symptoms in any part of the body.; upper arm score(OR=1.786 95% CI: 1.036-3.079) and posture score A(OR=1.634 95% CI: 1.016-2.626) in neck; muscel use score(OR=3.076 95% CI:1.782-5.310) and posture score A(OR=1.798 95% CI: 1.072-3.017) in shoulder; upper arm score(OR=1.715 95% CI: 1.083-2.715) and muscel use score(OR=2.057 95% CI:1.303-3.248) in neck & shoulder; muscle use score(OR=10.662 95% CI: 3.180-35.742) in arm; writst/wist score(OR=2.068 95% CI: 1.130-3.786) and muscle use score(OR=2.215 95% CI: 1.284-3.819) in hand & wrist.; muscle use score of trunk (OR=2.601 95% CI: 1.147-5.901) in back. Conclusions. Musculoskeletal symptoms of the extremities were strongly associated with individual RULA body score. These results show that RULA can be used as a useful assessment tool for the evaluation of musculoskeletal loading which is known to contribute to work-related musculoskeletal disorders. RULA also can be used as a screening tool or incorporated into a wider ergonomic assessment of epidemiological, physical, mental, environmental and organizational factors. As shown in this study, complement of the analysis system for the other risk factors and characterizing between the upper limb and back part will be needed for future work.

• Journal of Intelligence and Information Systems
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• v.20 no.4
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• pp.155-169
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• 2014

With the rapid advances in technologies, organizations are more likely to depend on information systems in their decision-making processes. Business Intelligence (BI) systems, in particular, have become a mainstay in dealing with complex problems in an organization, partly because a variety of advanced computational methods from statistics, machine learning, and artificial intelligence can be applied to solve business problems such as demand forecasting. In addition to the ability to analyze past and present trends, these predictive analytics capabilities provide huge value to an organization's ability to respond to change in markets, business risks, and customer trends. While the performance effects of BI system use in organization settings have been studied, it has been little discussed on the use of predictive analytics technologies embedded in BI systems for forecasting tasks. Thus, this study aims to find important factors that can help to take advantage of the benefits of advanced technologies of a BI system. More generally, a BI system can be viewed as an advisor, defined as the one that formulates judgments or recommends alternatives and communicates these to the person in the role of the judge, and the information generated by the BI system as advice that a decision maker (judge) can follow. Thus, we refer to the findings from the advice-giving and advice-taking literature, focusing on the role of explanations of the system in users' advice taking. It has been shown that advice discounting could occur when an advisor's reasoning or evidence justifying the advisor's decision is not available. However, the majority of current BI systems merely provide a number, which may influence decision makers in accepting the advice and inferring the quality of advice. We in this study explore the following key factors that can influence users' advice taking within the setting of a BI system: explanations on how the box-office grosses are predicted, types of advisor, i.e., system (data mining technique) or human-based business advice mechanisms such as prediction markets (aggregated human advice) and human advisors (individual human expert advice), users' evaluations of the provided advice, and individual differences in decision-makers. Each subject performs the following four tasks, by going through a series of display screens on the computer. First, given the information of the given movie such as director and genre, the subjects are asked to predict the opening weekend box office of the movie. Second, in light of the information generated by an advisor, the subjects are asked to adjust their original predictions, if they desire to do so. Third, they are asked to evaluate the value of the given information (e.g., perceived usefulness, trust, satisfaction). Lastly, a short survey is conducted to identify individual differences that may affect advice-taking. The results from the experiment show that subjects are more likely to follow system-generated advice than human advice when the advice is provided with an explanation. When the subjects as system users think the information provided by the system is useful, they are also more likely to take the advice. In addition, individual differences affect advice-taking. The subjects with more expertise on advisors or that tend to agree with others adjust their predictions, following the advice. On the other hand, the subjects with more knowledge on movies are less affected by the advice and their final decisions are close to their original predictions. The advances in predictive analytics of a BI system demonstrate a great potential to support increasingly complex business decisions. This study shows how the designs of a BI system can play a role in influencing users' acceptance of the system-generated advice, and the findings provide valuable insights on how to leverage the advanced predictive analytics of the BI system in an organization's forecasting practices.

• The Journal of Korean Society for Radiation Therapy
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• v.17 no.1
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• pp.19-31
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• 2005

Purpose : To supply the information of EPID system and to analyze the possibility of substitution EPID for film dosimetry. Materials & Methods : With amorphous silicon(aSi) type EPID and liquid filled lonization chamber(LC) type EPID, the reproducibility according to focus detector distance(FDD) change and gantry rotation was analyzed, and also the possible range of image acquisition was analyzed with Alderson Rando phantom. The resolution and the contrast of aSi type EPID image were analyzed through Las Vegas phantom and water phantom. DMLC image was analyzed with X-Omat V film and EPID to see wether it could be applied to the qualify assurance(QA) of IMRT. Results : The reproducibility of FDD position was within 1mm, but the reproducibility of gantry rotation was ${\pm}2,\;{\pm}3mm$ respectively. The resolution and the contrast of EPID image were affected by dose rate, image acquisition time, image acquisition method and frame number. According to the possible range of image acquisition of EPID, it is verified that the EPID is easier to use than film. There is no difference between X-Omat V film and EPID images for the QA of IMRT. Conclusion : Through various evaluation, we could obtain lots of useful information about the EPID. Because the EPID has digital data, also we found that the EPID is more useful than film dosimerty for the periodical Qualify Assurance of IMRT. Especially when it is difficult to do point dose measurement with diode or ionization chamber, the EPID could be very useful substitute. And we found that the diode and ionization chamber are difficult to evaluate the sliding window images of IMRT, but the EPID was more useful to do it.

• Korean Security Journal
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• no.18
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• pp.73-99
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• 2009

There are three assassination and treatening cases in this thesis introduced as analysis data. They are shooting accidents of the U.S.A's President Reagun (1981,3.30), and the President Park Jeong Hee of South Korea(1974.8.15), assassination of the Prime Minister Lavin of Israel (1995.11.4) In March 30, 1981, there was an accident where criminal, Hinckley, fired ball cartridges right before the President Reagan got into the car to move to White House after completing the announcement of Hilton Hotel of Washington. As a result, the chest of president was shot and public information secretary and safeguard were wounded. In August, 15, pm 10:23, where the 29th 8.15 independent anniversay event was being celebrated by the people at the National theater in Jangchungdong, Seoul, the criminal Moon Sekwang fired ball cartridges, he failed to assassinate the President Park Jeong Hee of Korea, but shot the First lady Yuk Young Soo. She was wounded right part of head and died. In November 4, Saturday, pm 22:00 the Prime Minster Lavin had finished the supporting event of Middle Asia's Peace project and was taking on the car when he was killed by the criminal Amir's shooting, The accidents left very important lesson from the aspect of security analysis and it has been frequently used as a material for the education and training of safeguard organization. In Korea, as well as Presidential Security Service, national security departments have selected it as an important model for the subjects such as 'Security Analysis, 'Security Practice' and 'Security Methodology'. In the performance of security duty, security skill is the most important matter. Moreover, it has a close relationship with politics, society and culture. The purpose of this study is to analyze and reevaluate the case, which has been treated as a usual model from the aspect of security analysis, beyond its introduction. Attempted assassination of President Reagan was evaluated as a positive success example because of its rapid response of adjacent guards to evacuate Reagan, who is a guard target, within 10 seconds after the shot. When comparing it to President Kennedy Assassination of 1963, it was evaluated that guards were significantly specialized. In the study, however, it was possible to found many problems such as carelessness of guard, who is in charge of external area of event place, idle attitude for frequently used event place, confusion of wireless communication, risk of wireless security disclose, insufficient provision of compulsory record file, insufficient profiling of dangerous person and unsecured hospital and first-aid room.

• Journal of the Mineralogical Society of Korea
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• v.22 no.4
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• pp.395-405
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• 2009

The maturity of amber matrix and inclusion was studied to explore the effect of heat treatment on the formation of the sun spangle in the transparent Baltic amber from Gdansk, Poland. Optical microscope revealed two types of inclusions in the original amber samples. The inclusions in the amber which had sun spangle were dramatically expanded by the heat treatment, comparing to those without sun spangle which contains fissure and shows different refractive index. The amber sample which didn't show sun spangle after the heat treatment showed a strong carbon related peak in TOF-SIMS spectra and weak oxygen related peak. it means that the maturity of this amber sample is comparatively higher than the one with spangle. The two amber samples show similar IR spectra before the heat treatment. However, the amber which had sun spangle exhibited an additional 1019 $cm^{-1}$ absorption peak and a more intense 887 $cm^{-1}$ peak. The different chemical compositions between the two types of amber is believed to be due to the different absorption spectra between 1000~600 $cm^{-1}$. According to the study of DSC analysis, the two samples show different DSC profiles. Although they have the same geological origin, their geological ages are different and have different chemical compositions. Thus, they exhibited different behavior after the heat treatment. The formation of sun spangle seemed to depend on the difference in the heat expansion rate of amber matrix with different maturity and chemical compositions.

• Korean Journal of Remote Sensing
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• v.37 no.3
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• pp.531-542
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• 2021

Open-pit mines require constant monitoring as they can cause surface changes and environmental disturbances. In open-pit mines, there is little vegetation at the mining site and can be monitored using InSAR (Interferometric Synthetic Aperture Radar) coherence imageries. In this study, activities occurring in mine were analyzed by applying the recently developed InSAR coherence-based NDAI (Normalized Difference Activity Index). The March 5 Youth Mine is a North Korean mine whose development has been expanded since 2008. NDAI analysis was performed with InSAR coherence imageries obtained using Sentinel-1 SAR images taken at 12-day intervals in the March 5 Youth Mine. First, the area where the elevation decreased by about 75.24 m and increased by about 9.85 m over the 14 years from 2000 was defined as the mining site and the tailings piles. Then, the NDAI images were used for time series analysis at various time intervals. Over the entire period (2017-2019), average mining activity was relatively active at the center of the mining area. In order to find out more detailed changes in the surface activity of the mine, the time interval was reduced and the activity was observed over a 1-year period. In 2017, we analyzed changes in mining operations before and after artificial earthquakes based on seismic data and NDAI images. After the large-scale blasting that occurred on 30 April 2017, activity was detected west of the mining area. It is estimated that the size of the mining area was enlarged by two blasts on 30 September 2017. The time-averaged NDAI images used to perform detailed time-series analysis were generated over a period of 1 year and 4 months, and then composited into RGB images. Annual analysis of activity confirmed an active region in the northeast of the mining area in 2018 and found the characteristic activity of the expansion of tailings piles in 2019. Time series analysis using NDAI was able to detect random surface changes in open-pit mines that are difficult to identify with optical images. Especially in areas where in situ data is not available, remote sensing can effectively perform mining activity analysis.

• Journal of the Korean Society of Radiology
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• v.9 no.1
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• pp.1-7
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• 2015

Acute phase patients who are unconscious and are suffering from cerebral infarction, cranial nerve disorders, or cerebral apoplexy are susceptible to aspiration pneumonia due to dysphagia. In these cases, a nasogastric tube is inserted to supply nutrients. Although bedside screening tests are administered during recovery after rehabilitation, clinical examinations may not be able to ascertain asymptomatic aspiration. Therefore, a video fluoroscopy swallowing study (VFSS) was performed in 10 patients with dysphagia after rehabilitation therapy; these patients had nasogastric tubes inserted, and a rehabilitation specialist assessed the degree of swallowing based on the patients' diet and posture. If aspiration or swallowing difficulties were observed, dysphagia rehabilitation therapy was administered. The patients were reassessed approximately 30-50 days after administration of therapy, based on the patients' condition. If aspiration is not observed, the nasogastric tube was removed. A functional dysphagia scale was used to analyze the VFSS images, and the scores were statistically calculated. The mean score of patients with nasogastric tubes was $49.79{\pm}9.431$, thereby indicating aspiration risk, whereas the group without nasogastric tubes showed a mean score of $11.20{\pm}1.932$, which indicated low risk of aspiration. These results demonstrated that a significantly low score was associated with nasogastric tube removal. Mann-Whitney's test was performed to assess the significance of both the groups, and the results were statistically significant with a P value <0.001. In conclusion, VFSS can effectively assess the movements and structural abnormalities in the oral cavity, pharynx, and esophagus. It can also be used to determine the aspiration status and ascertain the appropriate diet or swallowing posture for the patient. Therefore, VFSS can potentially be used as a reliable standard test to assess swallowing in order to determine nasogastric tube removal.