• Journal of Platform Technology
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• v.9 no.4
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• pp.3-9
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• 2021

In this paper, a graph data model is introduced to effectively recognize the situation between each object on the road detected by vehicles or road infrastructure sensors. The proposed method builds a graph database by modeling each object on the road as a node of the graph and the relationship between objects as an edge of the graph, and updates object properties and edge properties in real time. In this case, the relationship between objects represented as edges is set when there is a possibility of approach between objects in consideration of the position, direction, and speed of each object. Finally, we propose a spatial indexing technique for graph nodes and edges to update the road object graph database represented through the proposed graph modeling method continuously in real time. To show the superiority of the proposed indexing technique, we compare the proposed indexing based database update method to the non-indexing update method through simulation. The results of the simulation show the proposed method outperforms more than 10 times to the non-indexing method.

• Journal of Information Technology Services
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• v.20 no.5
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• pp.89-104
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• 2021

Food delivery service combined with IT technology and HMR (Home Meal Replacement) are rapidly growing due to the COVID-19. Recently, the demand for salads along with HMR has increased among office workers in their 20s and 30s who are interested in health and beauty. Freshcode is a food startup with 6 years of experience that started selling salad products through O2O service. Freshcode applied for a patent for a service that collects orders from nearby areas and delivers them on the same day to a designated delivery address 'FCOSPOT' to save shipping costs. In March 2021, in recognition of the growth potential of the regular delivery service, Freshcode received an investment of 6 billion won in Series A. This study may have practical implications to early-stage startups and scale-up stage startups through a longitudinal case study on the growth of a single company. As for the research method, the lean startup methodology and lean canvas were used in the early stage of startup. In particular, the process of the build-measure and learn feedback-loop, which is the core of lean startup methodology, was applied to each major decision-making step. In the scale-up stage after 5 years, the business model canvas was used to schematize the growth as a food online O2O platform to verify continuous innovation. This case study has three main findings. First, the idea of 'FCOSPOT' was successfully implemented through the Lean Startup methodology. Second, Freshcode demonstrated the scalability of the differentiated business model of shared base delivery O2O. Third, a key factor of success was the digital integrated communication operation strategy that maximizes the experience for the created customers.

• International Journal of Oral Biology
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• v.46 no.4
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• pp.168-175
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• 2021

To investigate the perceptions and attitudes of dental hygienists toward radiation safety management in Korea. A total of 800 dental hygienists were randomly selected for an anonymous survey, and 203 of them participated. The questionnaire items included the following: sex, career period, type of installed radiographic equipment, recognition of the diagnostic reference level (DRL), participation in radiation safety education, and attitudes toward radiation protection for both patients and dental hygienists. The participants were divided into two groups according to their years of experience (< 10 years versus ≥ 10 years). The difference between the groups was investigated according to frequency distribution. Fisher's exact test or Pearson's chi-square (𝛘²) test was used as appropriate. A regression analysis was performed to investigate the impact of wearing a thyroid collar for personnel protection during patient radiation exposure. The types of installed radiographic equipment included panoramic radiography (96.1%), cephalometric radiography (76.9%), intraoral radiography (72.9%), and cone-beam computed tomography (69.5%). Significant differences were observed in the learning pathway for the DRL (Fisher's exact test, p < 0.05), satisfaction with radiation safety education (Pearson's 𝛘² test = 5.3975, Pr = 0.02), and use of personnel radiation monitoring systems (Pearson's 𝛘² test = 18.1233, Pr = 0.000) between the groups. Significant differences were also observed in personnel protection using a thyroid collar and patient protection during panoramic radiography (odds ratio = 14.2). Dental hygienists with more than 10 years of experience were more satisfied with radiation safety education and more interested in radiation monitoring. Considering career experience, customized, continuous, and effective radiation safety management education should be provided.

• Anayses & Alternatives
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• v.4 no.2
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• pp.103-132
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• 2020

The purpose of this study is to observe whether intergenerational differences exist in support among major Korean political parties and, if so, how they exist, based on the results of the survey conducted nationwide. To achieve the purpose of the study, a questionnaire was prepared based on conjoint analysis, and the collected data was analyzed by applying a random parameter logit model. The main results of model analysis are summarized as follows. First, among the policy variables, statistically significant results were observed in the generation of 20s and 30s for the education variable. It was found that both 20s and 30s aimed for equal education at a higher level than other generations. Especially, the highest intensity aim for equal education culture was observed in the 20s. Second, the coefficients of major political parties were observed with a high level of statistical significance. This appears to be a result suggesting that voters decide on their voting behavior through thorough policy comparisons in addition to comprehensive consideration on various current issues. Third, a clear support for conservative parties was observed in the generation of 20s. A clear and intense distribution of preference for political parties classified as conservatives was observed in the 20s generation, which can be said to be mainly college students. This seems to be a profound founding related to the issue of "conservatization of the 20s," which has recently become a hot topic in Korean society. Fourth, a high level of support for progressive parties was observed in the 30s and 40s. The Justice Party can be classified as a minority party in the National Assembly House as of January 2019. Nevertheless, it was maintained at a relatively high level in national recognition, and it is presumed that the background was high level of support from the 30s and 40s. Fifth, a large level of standard deviation was observed in the preference for conservative parties in the 50s. This means that some respondents who are in their 50s or older strongly support the Liberty Korea Party, and some respondents in the same generation strongly disapprove it. Due to this countervailing power, it seems that the average support level for the Liberal Korean Party is low in the generations of 50s and older.?

• Journal of the Society of Disaster Information
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• v.18 no.1
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• pp.154-162
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• 2022

Purpose: The government intends to come up with measures to revitalize safety management at construction sites to shift safety management at construction sites from human capabilities to system-oriented management systems using advanced technologies AIoT and Mobile technologies. Method: The construction site safety management monitoring system using AIoT and Mobile technology conducted an experiment on the effectiveness of the construction site by applying three algorithms: virtual fence, fire monitoring, and recognition of not wearing a safety helmet. Result: The number of workers in the experiment was 215 and 7.61 virtual fence intrusion was 3.5% compared to the number of subjects and 0.16 fire detection were 0.07% compared to the subjects, and the average monthly rate of not wearing a safety helmet was 8.79, 4.05% compared to the subjects. Conclusion: It was found that the construction site safety management monitoring system using AIoT and Mobile technology has a valid effect on the construction site.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.6
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• pp.214-227
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• 2021

The purpose of this study is to find the driving difficulty of automated vehicles in terms of road infrastructure operation. It was judged out of this study that the level of automated driving would be enhanced if the road situation recognition ability was advanced through the presentation of infrastructure information during the difficult driving situations. The difficulty evaluation index was divided into three stages, and a survey of experts and an AHP were conducted. The result of the AHP showed that the driving difficulty of the interrupted flow was much higher than that of the uninterrupted flow. The AHP results also showed that and the driving difficulty of unsignalized intersections and roundabouts under an interrupted flow was evaluated as the highest. The top six driving situations with high difficulty were also evaluated to occur under unsignalized intersections and roundabouts.

• Journal of the Korean Dietetic Association
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• v.28 no.1
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• pp.1-18
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• 2022

This study was conducted to estimate the appropriate workforce of dietitians by type of kindergarten through the recognition survey and job analysis of the kindergarten. Nutritionists' duties were classified into 6 duties, 28 tasks and 94 task elements. The statistical data analysis was completed using Statistical Package for the Social Sciences (SPSS) (ver. 25.0). The time spent on 6 duties, including 'Nutrition management' (public attached 666.24 hours/year, public independent 843.04 hours/year), 'Foodservice management Practices' (public attached 1,472.52 hours/year, public independent 1,298.11 hours/year), 'Hygiene management of kindergarten foodservice' (public attached 611.78 hours/year, public independent 607.18 hours/year), 'Nutrition-diet education and counseling' (public attached 340.53 hours/year, public independent 253.42 hours/year), 'Managing snack during semesters and lunch/snacks during breaks' (public independent 309.04 hours/year) and 'Professionalism enhancement' (public attached 88.86 hours/year; public independent 65.17 hours/year). Total working hours for dietitians were 3,179.94 hours/year (public attached) and 3,375.97 hours/year (public independent). The time/day ×5 days/week ×52 weeks/year calculation method using derived total working hours/year was applied to derive appropriate full-time equivalents (FTEs). The analysis showed that the public attached kindergarten's FTEs were 1.53. The public independent's FTEs were 1.62, and the total FTEs were 1.55. This is the first study to analyze the workload of kindergarten dietitians and appropriate manpower by kindergarten establishment type. It is expected to be a valuable policy basis for efficient operation measures related to the kindergarten dietitians.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.3
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• pp.529-536
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• 2022

In the past two years, Severe Acute Respiratory Syndrome Coronavirus-2(SARS-CoV-2) has been hitting more and more to people. This paper proposes a novel U-Net Convolutional Neural Network to classify and segment COVID-19 lung CT images, which contains Sub Coding Block (SCB), Atrous Spatial Pyramid Pooling(ASPP) and Attention Gate(AG). Three different models such as FCN, U-Net and U-Net-SCB are designed to compare the proposed model and the best optimizer and atrous rate are chosen for the proposed model. The simulation results show that the proposed U-Net-MMFE has the best Dice segmentation coefficient of 94.79% for the COVID-19 CT scan digital image dataset compared with other segmentation models when atrous rate is 12 and the optimizer is Adam.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.1
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• pp.99-104
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• 2022

Artificial intelligence is getting a crucial part of our lives with its incredible benefits. Machines outperform humans in recognizing objects in images, particularly in classifying people into correct age and gender groups. In this respect, age and gender classification has been one of the hot topics among computer vision researchers in recent decades. Deployment of deep Convolutional Neural Network(: CNN) models achieved state-of-the-art performance. However, the most of CNN based architectures are very complex with several dozens of training parameters so they require much computation time and resources. For this reason, we propose a new CNN-based classification algorithm with significantly fewer training parameters and training time compared to the existing methods. Despite its less complexity, our model shows better accuracy of age and gender classification on the UTKFace dataset.

• Journal of the Korea Society for Simulation
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• v.31 no.2
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• pp.11-20
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• 2022

There is a critical need for AI assistance in guard operations of Army base perimeters, which is exacerbated by changes in the national defense and security environment such as force reduction. In addition, the possibility for human error inherent to perimeter guard operations attests to the need for an innovative revamp of current systems. The purpose of this study is to propose a real-time object detection AI tailored to military CCTV surveillance with three unique characteristics. First, training data suitable for situations in which relatively small objects must be recognized is used due to the characteristics of military CCTV. Second, we utilize a data augmentation algorithm suited for military context applied in the data preparation step. Third, a noise reduction algorithm is applied to account for military-specific situations, such as camouflaged targets and unfavorable weather conditions. The proposed system has been field-tested in a real-world setting, and its performance has been verified.