• KIPS Transactions on Software and Data Engineering
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• v.8 no.7
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• pp.289-302
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• 2019

Structural change of time series means that the distribution of observations is relatively stable in the period of constituting the entire time series data, but shows a sudden change of the distribution characteristic at a specific time point. Within a non-stationary long-term time series, it is important to determine in a timely manner whether the change in short-term trends is transient or structurally changed. This is because it is necessary to always detect the change of the time series trend and to take appropriate measures to cope with the change. In this paper, we propose a method for decision makers to easily grasp the structural changes of time series by visualizing the test results based on the unit root test. Particularly, it is possible to grasp the short-term structural changes even in the long-term time series through the method of dividing the time series and testing it.

• Archives of Plastic Surgery
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• v.46 no.5
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• pp.399-404
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• 2019

Background The objectives of this study were to design polycaprolactone nanofibers with a radial pattern using a modified electrospinning method and to evaluate the effect of radial nanofiber deposition on mechanical and biological properties compared to non-patterned samples. Methods Radially patterned polycaprolactone nanofibers were prepared with a modified electrospinning method and compared with randomly deposited nanofibers. The surface morphology of samples was observed under scanning electron microscopy (SEM). The tensile properties of nanofibrous mats were measured using a tabletop uniaxial testing machine. Fluorescence-stained human bone marrow stem cells were placed along the perimeter of the radially patterned and randomly deposited. Their migration toward the center was observed on days 1, 4, and 7, and quantitatively measured using ImageJ software. Results Overall, there were no statistically significant differences in mechanical properties between the two types of polycaprolactone nanofibrous mats. SEM images of the obtained samples suggested that the directionality of the nanofibers was toward the central area, regardless of where the nanofibers were located throughout the entire sample. Florescence images showed stronger fluorescence inside the circle in radially aligned nanofibers, with significant differences on days 4 and 7, indicating that migration was quicker along radially aligned nanofibers than along randomly deposited nanofibers. Conclusions In this study, we successfully used modified electrospinning to fabricate radially aligned nanofibers with similar mechanical properties to those of conventional randomly aligned nanofibers. In addition, we observed faster migration along radially aligned nanofibers than along randomly deposited nanofibers. Collectively, the radially aligned nanofibers may have the potential for tissue regeneration in combination with stem cells.

• Steel and Composite Structures
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• v.30 no.5
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• pp.417-432
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• 2019

This paper presents the results of axial compression testing and numerical modeling on reinforced concrete columns (RCC) with normal concrete (NC) and high-strength concrete (HSC), RCC confined by glass-fiber reinforced plastic pipes (GRP) casing as well as carbon fiber reinforced polymer (CFRP), The major parameters evaluated in the experiments were the effects of concrete type, GRP casing and CFRP wrapping, as well as the number of CFRP layers. 12 cylindrical RCC ($150{\times}600mm$) were prepared and divided into two groups, NC and HSC. Each group was divided into two parts; with and without GRP casing. In each part, one column was without CFRP strengthening layer, a column was wrapped with one CFRP layer and another column with two CFRP layers. All columns were tested under concentrated compression load. Numerical modeling was performed using ABAQUS software and the results of which were compared with experimental findings. A good agreement was found between the results. Results indicated that the utilization of CFRP wrapping and GRP casing improved compression capacity and ductility of RCC. The addition of one and two layer-FRP wrapping increased capacity in the NC group to an average of 18.5% and 26.5% and in the HSC group to an average of 10.2% and 24.8%. Meanwhile, the utilization of GRP casing increased the capacity of the columns by 3 times in the NC group and 2.38 times in the HSC group. The results indicated that although both CFRP wrapping and GRP casing increased confinement, the GRP casing gave more increase capacity and ductility of the RCC due to higher confinement. Furthermore, the confinement effect was higher on NC group.

• KIPS Transactions on Software and Data Engineering
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• v.8 no.4
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• pp.163-170
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• 2019

Korea language has postpositions such as eul, reul, yi, ga, wa, and gwa, which are attached to nouns and add meaning to the sentence. When foreign notations or abbreviations are included in sentences, the appropriate postposition for the pronunciation of the foreign words may not be used. Sometimes, for natural expression of the sentence, two postpositions are used with one in parentheses as in "eul(reul)" so that both postpositions can be acceptable. This study finds examples of using unnatural postpositions when foreign words are included in Korean sentences and proposes a method for using natural postpositions by learning the final consonant pronunciation of nouns. The proposed method uses a recurrent neural network model to naturally express postpositions connected to foreign words. Furthermore, the proposed method is proven by learning and testing with the proposed method. It will be useful for composing perfect sentences for machine translation by using natural postpositions for English abbreviations or new foreign words included in Korean sentences in the future.

• Journal of Industrial Convergence
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• v.19 no.1
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• pp.1-6
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• 2021

The purpose of this study is to find a way to increase the examination rate by presenting the current state of national health examination. To this end, demographic factors(Gender, age, income level, education level) and health factors(Smoking, alcohol, obesity, subjective health status) were selected, and whether the selected factors were different for each group, and the examinees according to the number of hospitals and income level were visualized. As a result, except for subjective health status in health factors, population factors, and number of hospitals were all related to the examination. In addition, among the age factors of the demographic factor, those in their twenties and those with a low income level and those who were underweight among the health factors of obesity had a high rate of non-testing. Therefore, it is considered necessary to promote, support, and educate those untested by these groups.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.3
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• pp.223-230
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• 2021

Currently, self-driving vehicles are on the verge of commercialization after testing. However, even though autonomous vehicles have not been fully commercialized, 81 accidents have occurred, and the driving method of vehicles to avoid accidents relies heavily on LiDAR. In order for the currently commercialized 3-level autonomous vehicle to develop into a 4-level autonomous vehicle, more information must be collected than previously collected information. Therefore, this paper proposes a Driving Situation Judgment System (DSJS) that accurately calculates the crisis situation the vehicle is in by useing the roughness of the road and the state of the passengers of surrounding vehicles including road information and weather information collected from existing autonomous vehicles. As a result of DSJS's PDM experiment, PDM was able to classify passengers 15.52% more accurately on average than the existing vehicle's passenger recognition system. This study can be a basic research to achieve the 4th level autonomous vehicle by collecting more various types than the data collected by the existing 3rd level autonomous vehicle.

• Research in Community and Public Health Nursing
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• v.31 no.4
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• pp.416-426
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• 2020

Purpose: The aim of this study was to evaluate the validity and reliability of the Korean version of Short-form Health Literacy Scale (HLS-SF-K12) for Adults. Methods: The English HLS-SF12 was translated into Korean with forward and backward translation. Survey data were collected from 204 adults who visited two hospitals in Korea. Content validity, construct validity, and known-groups validity were evaluated. Cronbach's α for internal consistency and test-retest were used to assess reliability. SPSS 21.0 and AMOS 21.0 software were used for data analysis. Results: The HLS-SF-K12 was composed of 12 items, and three subscales (health care, disease prevention, and health promotion). The instrument explained reliable internal consistency with Cronbach's α for the total scale of .89, and .74~.81 for subscales. The model of three subscales for the HLS-SF-K12 was validated by confirmatory factor analysis (Normed χ2=2.14 (p<.001), GFI=.92, RMR=.04, RMSEA=.08, CFI=.94, TLI=.92, IFI=.94). The hypothesis testing which analyzed the differences in health literacy by age and education level was satisfied. Conclusion: The HLS-SF-K12 is a valid and reliable instrument for measuring health information comprehension for adults in Korea.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.6
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• pp.211-222
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• 2021

Recently, frozen and refrigerated appliances on the market are being released with additional IoT functions, but there are few tests on IoT functions. In particular, the existing test system does not have IoT test items for IoT-based frozen and refrigerated appliances, making it difficult for companies to find the cause even if defects occur, and test institutions are also restricted from selecting IoT-related test items and conducting correct performance tests. In this paper, we design a test item framework that can identify product defects and identify causes in the performance test process of frozen and refrigerated products with IoT functions among products in the home appliance field, and propose test methods and management measures using them. Through the proposed research, manufacturers and testing institutions can test the correct performance of IoT-based frozen and refrigerated products, thereby enhancing the completeness and securing reliability of the products.

• Journal of the Institute of Convergence Signal Processing
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• v.22 no.3
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• pp.110-115
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• 2021

With the era of the 4th Industrial Revolution, education on artificial intelligence is one of the important topics. However, since existing education is aimed at knowledge, it is not suitable for developing the active problem-solving ability and AI utilization ability required by artificial intelligence education. To solve this problem, we proposes PBL-based education method in which learners learn in the process of solving the presented problem. The problem presented to the learner is a completed project. This project consists of three types: a classification model, the training data of the classification model, and the block code to be executed according to the classified result. The project works, but each component is designed to perform a low level of operation. In order to solve this problem, the learners can expect to improve their computational thinking skills by finding problems in the project through testing, finding solutions through discussion, and improving to a higher level of operation.

• The Journal of Advanced Prosthodontics
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• v.13 no.6
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• pp.351-360
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• 2021

PURPOSE. The aim of this study was to evaluate the efficiency of occlusal and interproximal adjustments of single implant crowns (SIC), comparing a digital cast-free approach (CF) and a protocol using 3D printed casts (PC). MATERIALS AND METHODS. A titanium implant was inserted at position of lower right first molar in a typodont. The implant position was scanned using an intraoral scanner and SICs were fabricated accordingly. Ten crowns (CF; n = 10) were subject to a digital cast-free workflow without any labside occlusal and interproximal modifications. Ten other identical crowns (PC) were adjusted to 3D printed casts before delivery. All crowns were then adapted to the testing model, simulating chair-side adjustments during clinical placement. Adjustment time, quantity of adjustments, and contact relationship were assessed. Data were analyzed using SPSS software (P < .05). RESULTS. Median and interquartile range (IQR) of clinical adjustment time was 02:44 (IQR 00:45) minutes in group CF and 01:46 (IQR 00:21) minutes in group PC. Laboratory and clinical adjustment time in group PC was 04:25 (IQR 00:59) minutes in total. Mean and standard deviation (±SD) of root mean squared error (RMSE) of quantity of clinical adjustments was 45 ± 7 ㎛ in group CF and 34 ± 6 ㎛ in group PC. RMSE of total adjustments was 61 ± 11 ㎛ in group PC. Quality of occlusal contacts was better in group CF. CONCLUSION. Time effort for clinical adjustments was higher in the cast-free protocol, whereas quantity of modifications was lower, and the occlusal contact relationship was found more favourable.