• Korean Journal of Remote Sensing
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• v.39 no.5_1
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• pp.589-597
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• 2023

Floating debris in large quantities from land during heavy rainfall has adverse social, economic, and environmental impacts, but the monitoring system for the concentration area and amount is insufficient. In this study, we proposed an efficient monitoring method for floating debris entering the river during heavy rainfall in Daecheong Lake, the largest water supply source in the central region, and applied remote sensing techniques to estimate the standing-stock of floating debris. To investigate the status of floating debris in the upper of Daecheong Lake, we used a tracking buoy equipped with a low-orbit satellite communication terminal to identify the movement route and behavior characteristics, and used a drone to estimate the potential concentration area and standing-stock of floating debris. The location tracking buoys moved rapidly during the period when the cumulative rainfall for 3 days increased by more than 200 to 300 mm. In the case of Hotan Bridge, which showed the longest distance, it moved about 72.8 km for one day, and the maximum moving speed at this time was 5.71 km/h. As a result of calculating the standing-stock of floating debris using a drone after heavy rainfall, it was found to be 658.8 to 9,165.4 tons, with the largest amount occurring in the Seokhori area. In this study, we were able to identify the main concentrations of floating debris by using location-tracking buoys and drones. It is believed that remote sensing-based monitoring methods, which are more mobile and quicker than traditional monitoring methods, can contribute to reducing the cost of collecting and processing large amounts of floating debris that flows in during heavy rain periods in the future.

• Korea Trade Review
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• v.48 no.4
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• pp.303-320
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• 2023

Recently, import and export companies have been using T/T remittance and Surrender B/L more frequently than L/C when selecting the process and method of trade payment settlement. The new trade and logistics environment is thriving in the era of the Fourth Industrial Revolution (4IR). Document-based trade transactions are undergoing a digitalization as bills of lading or smart contracts are being developed. The purpose of this study is to verify whether exporters choose export payment types based on negotiating factors. In addition, we would like to discuss the application of the characteristics of the new trade and logistics environment. Data for analysis was collected through surveys. The collection method consisted of direct visits to the company, e-mail, fax, and online surveys. The survey distribution period is from February 1, 2023, to April 30, 2023. The questionnaire was distributed in 2,000 copies, and 447 copies were collected. The final 336 copies were used for analysis, excluding 111 copies that were deemed inappropriate for the purpose of this study. The results of the study are shown below. First, among the negotiating factors, the product differentiation of exporters did not significantly affect the selection of export payment types. Second, among the negotiating factors, the greater the purchasing advantage recognized by exporters, the higher the possibility of using the post-transfer method. In addition to analyzing the results, this study suggests that exporters should consider adopting new payment methods, such as blockchain technology-based bills of lading and trade finance platforms, to adapt to the characteristics of the evolving trade and logistics environment. Therefore, exporters should continue to show interest in initiatives aimed at digitizing trade documents as a response to the challenges posed by bills of lading. In future studies, it is necessary to address the lack of social awareness in Korea by conducting advanced research abroad.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.4
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• pp.21-35
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• 2023

Expectations surrounding generative AI technology and its profound ramifications are sweeping across various industrial domains. Given the anticipated pivotal role of the startup ecosystem in the utilization and advancement of generative AI technology, it is imperative to cultivate a deeper comprehension of the present state and distinctive attributes characterizing venture capital (VC) investments within this domain. The current investigation delves into South Korea's landscape of VC investment deals and prognosticates the projected VC investments by juxtaposing these against the United States, the frontrunner in the generative AI industry and its associated ecosystem. For analytical purposes, a compilation of 286 investment deals originating from 117 U.S. generative AI startups spanning the period from 2008 to 2023, as well as 144 investment deals from 42 South Korean generative AI startups covering the years 2011 to 2023, was amassed to construct new datasets. The outcomes of this endeavor reveal an upward trajectory in the count of VC investment deals within both the U.S. and South Korea during recent years. Predominantly, these deals have been concentrated within the early-stage investment realm. Noteworthy disparities between the two nations have also come to light. Specifically, in the U.S., in contrast to South Korea, the quantum of recent VC deals has escalated, marking an augmentation ranging from 285% to 488% in the corresponding developmental stage. While the interval between disparate investment stages demonstrated a slight elongation in South Korea relative to the U.S., this discrepancy did not achieve statistical significance. Furthermore, the proportion of VC investments channeled into generative AI enterprises, relative to the aggregate number of deals, exhibited a higher quotient in South Korea compared to the U.S. Upon a comprehensive sectoral breakdown of generative AI, it was discerned that within the U.S., 59.2% of total deals were concentrated in the text and model sectors, whereas in South Korea, 61.9% of deals centered around the video, image, and chat sectors. Through forecasting, the anticipated VC investments in South Korea from 2023 to 2029 were derived via four distinct models, culminating in an estimated average requirement of 3.4 trillion Korean won (ranging from at least 2.408 trillion won to a maximum of 5.919 trillion won). This research bears pragmatic significance as it methodically dissects VC investments within the generative AI domain across both the U.S. and South Korea, culminating in the presentation of an estimated VC investment projection for the latter. Furthermore, its academic significance lies in laying the groundwork for prospective scholarly inquiries by dissecting the current landscape of generative AI VC investments, a sphere that has hitherto remained void of rigorous academic investigation supported by empirical data. Additionally, the study introduces two innovative methodologies for the prediction of VC investment sums. Upon broader integration, application, and refinement of these methodologies within diverse academic explorations, they stand poised to enhance the prognosticative capacity pertaining to VC investment costs.

• Journal of Wetlands Research
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• v.26 no.2
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• pp.147-159
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• 2024

Lack of streamflow observations makes model calibration difficult and limits model performance improvement. Satellite-based remote sensing products offer a new alternative as they can be actively utilized to obtain hydrological data. Recently, several studies have shown that artificial intelligence-based solutions are more appropriate than traditional conceptual and physical models. In this study, a data-driven approach combining various recurrent neural networks and decision tree-based algorithms is proposed, and the utilization of satellite remote sensing information for AI training is investigated. The satellite imagery used in this study is from MODIS and SMAP. The proposed approach is validated using publicly available data from 25 watersheds. Inspired by the traditional regionalization approach, a strategy is adopted to learn one data-driven model by integrating data from all basins, and the potential of the proposed approach is evaluated by using a leave-one-out cross-validation regionalization setting to predict streamflow from different basins with one model. The GRU + Light GBM model was found to be a suitable model combination for target basins and showed good streamflow prediction performance in ungauged basins (The average model efficiency coefficient for predicting daily streamflow in 25 ungauged basins is 0.7187) except for the period when streamflow is very small. The influence of satellite remote sensing information was found to be up to 10%, with the additional application of satellite information having a greater impact on streamflow prediction during low or dry seasons than during wet or normal seasons.

• Journal of Korean Society of Forest Science
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• v.19 no.1
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• pp.1-23
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• 1973

The results of ground vegetation experiment conducted at completely denuded forestland in the mudstone region are summerized as follows: On the reaults of soiling quantity the effect of soiling was observed where depth of soiling over 10 cm was practiced, and a plot where treated with 15cm soiling and without fertilizer showed poor growth and it was even worser than the plot where soiling was practiced only 1 cm in thikness but applied adequate amount of fertilizers. The depth of slits between 30cm and 40cm showed no significant difference in the effect. A plot where covered with vegetation bag showed somewhat better results in seed loss and early growth but no differences observed in the fall result over the none covered plot. And then, it is recommendable to have soiling over 10cm in thikness with slit of 30cm and 30cm in depth and to apply 30 gram of fertilizer (22;22:11, 50 gram) per slit. On various soiling materials trial there were no striking differences in the effect of soiling between weathered granite soil, wheathered tuffs soil and weathered mudstone soil. In the treatment with various green materials, a plot treated with straw mat showed a significant difference at 1 percent. The results show that weathered mudstone soil is effective to use as soiling materials and straw mat treatment was better. On forest fertilization trial, in the mudstone region where red and black pine trees already existing at a rate of 2,000-3,000 trees per hectare had applied 110kg of compound fertilizers (9:12:3 and 22:22:11) per hectare basis in terms of plant nutrient. As a result, the difference in effect between the compound fertilizers was not found however the leaf color and leaf length of the fertilizer added plot showed darker and longer at 30 percent over the no fertilizer received plot. Compound fertilizers, 14:37:12 and 9:12:3 were applied to alder trees at a rate of 20 gram and 40 gram per tree in terms of plant nutrient and a remarkable growth accelerantion was observed where 40 grams of plant nutrient applied. The effect difference between the compound fertilizers was not found. On investigation of tree root elongation, forty years old red pine trees showed only 15cm tap root elongation through mudstone while black pine had 23 cm tap root elongation. The total length of supporting root elongtion of red and black pines showed 20 and 13 meters, respectively. The tap roots of Black locusts were not able to elongate through mudstone, however, the supporting roots tended to develop to the underneath of pine tree where some moisture content is available. Black locusts And grown on the residual soil of mudstone normally die between 8 to 10 years. The red pine trees show flat in tree shape while black pine had triangle in the shape. With the results it can be said that in an artificial reforestation in denuded forest land of the mudstone region the adequate slit and enough amount of fertiliizer application must be provided for the succesful performance of the program. On integrated experimental results of 1972. for the establishment of ground vegetation on the completely denuded forest land in mudstone region, soiling could be effectively practiced with weathered mudstone soil and it would not specially necessiate to have either weathered granite or tuffssoil for the soiling. And the soiling depth should be more than 10 cm in thickness. Among green materials used the straw mat proved to be the most effective reatment. Three major factors which enable to establish ground vegetation by the shortest period of time: A. Physical improvement of soil is necessary to breakdown of the horizontal cracks sushas Slit, contour line plot, seeding hole and etc., and soiling with weathered mudstone soil. B. Chemical improvement of soil: is needed sufficient amount of fertilizer application 300~400kg ha, $N+P_2O_5+K_2O$), and increased production of ground covering and expedite resolution of the vegetation (ground vegetation, fallen leaves and twigs). C. Complete establishment of the basic structure for the erosion control (Prevention of surface soil erosion)

• Journal of Korean Society of Forest Science
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• v.50 no.1
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• pp.36-44
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• 1980

This study was conducted in order to obtain basic information for the development of a special compound fertilizer of the trials for chestnut tree cultivation in 1979-1980. Results were as follows: 1. Differences in growth performence after application of single, compound and special compound fertilizer was not significant, but fertilized showed more vigorous growth compared to control plots (without fertilizer). 2. Appearance of Chestnut strobile-drops was observed at: 62.2 % in control plots, 37-50 % in each single and compound fertilizer plots and in those with the double amount of compound fertilizer, 0.7 % in special compound fertilizer plots, 6.2 % in those with double amount of special compound fertilizer. 3. Riped strobiles were collected: 249 in compound fertilizer plots, 625 in special compound fertilizer plots, 391 in double amount of compound fertilizer plots, 816 in double amount of special compound fertilizer plots. 4. The production of chestnuts was: 4,662g in single fertilizer plots, 4,678g in compound fertilizer plots, 28,880g special compound fertilizer plots, 11,736g double amount of compound fertilizer plots, 33,073g double amount of special compound fertilizer plots. There was on significant differences of chestnut production between single fertilizer plots and compound fertilizer plot, but the production in double amount of special compound fertilizer plots was three time higher than in double amount of compound fertilizer plots. 5. The amount of chestnut production in 1980 dcereased compared to 1979 in single and compound fertilize plots due to shortage of sun light and high precipitation in the vegetation period but increased two times more in 1980 compared to 1979 in double amount of compound fertilizer and double amount of specific compound fertilizer plots. 6. Observation of these fertilizer-trial-plots will be continued during the next years in order to obtain more specific datas.

• Journal of Sericultural and Entomological Science
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• v.47 no.2
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• pp.68-77
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• 2005

A characteristic of subtropical zones region MK-T2 compares with an gaeryangppong, and the 9-10 schedule the times when a leaf blooms to are fast, and ratio that a branch edge by the colds becomes lean showed 5.7%, and a growth of the new branch which went out delivers 67.2 cm, mulberry loaves of the new branch which went out, and 18.6, a form of a leaf is the 1.10 that length of a leaf grew more a bit than width of a leaf up. Thickness of a leaf is $228.2{\mu}m$, and an area is more similar than gaeryangppong as $225.6cm^2$. in plant taxonomy, the hair whom the style exists short with 0.7 mm, and go to the pistil head inside so as to be rare is distributed, and belong to Dolichostylae Pubescentes. The new branch cutting which executed without remedy processes was independent of a thickness of a case branch, and the form and 100% root was said, and an gaeryangppong compared with the fact that 10% root went out of 15 mm ideal, and was excellent very, and looked, a root went out a root the soil and water, all showed a characteristic to go out at central of a branch bases at 45% ratio. Length was 24.6 mm, and were water rate 78.8%, and mulberry of MK-T2 was carrying together sweetness and acidity to pH 4.7 while, besides, arrival was 19.21 Brix%. A larva period and pupa ratio, cocoon thickness ratio are almost similar to gaeryangppong, or weight of one cocoon, cocoon thickness, 20,002 cocoon quantity shows some results to drop, and be soft of a leaf, and feed value certifications are comparatively top-ranking. As a result of having analyzed amino acid of the 3rd day of 5th silkworm larva which bred to MK-T2, a collation absorbing an gaeryangppong went, and looked, but compared with a collation in case of tests to eat MK-T2, and looked, and the lie collations were not detected a difference at Leu, but MK-T2 tests were detected mutual almost similar amino acid creation. medical efficacy of the 3rd day of 5th silkworm larva ethanol extract which bred to MK-T2 and black results, histologic a case did not appear at HE dyeing about the kidney organization which extracted form the rats which ate a silkworm ethanol extract and dyeing all chemical organization immunity, and one step protein revelation became lower with almost unidentified levels.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.67-72
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• 2010

Purpose: In Asan Medical Center we perform myocardial perfusion SPECT to evaluate cardiac event risk level for non-cardiac surgery patients. In case of patients with cancer, we check tumor metastasis using whole body bone scan and whole body PET scan and then perform myocardial perfusion SPECT to reduce unnecessary exam. In case of short term in patients, we perform $^{201}Tl$ myocardial perfusion SPECT after whole body bone scan a minimum 16 hours in order to reduce hospitalization period but it is still the actual condition in which the evaluation about the affect of the crosstalk contamination due to the each other dissimilar isotope administration doesn't properly realize. So in our experiments, we try to evaluate crosstalk contamination influence on $^{201}Tl$ myocardial perfusion SPECT using anthropomorphic torso phantom and patient's data. Materials and Methods: From 2009 August to September, we analyzed 87 patients with $^{201}Tl$ myocardial perfusion SPECT. According to $^{201}Tl$ myocardial perfusion SPECT yesterday whole body bone scan possibility of carrying out, a patient was classified. The image data are obtained by using the dual energy window in $^{201}Tl$ myocardial perfusion SPECT. We analyzed $^{201}Tl$ and $^{99m}Tc$ counts ratio in each patients groups obtained image data. We utilized anthropomorphic torso phantom in our experiment and administrated $^{201}Tl$ 14.8 MBq (0.4 mCi) at myocardium and $^{99m}Tc$ 44.4 MBq (1.2 mCi) at extracardiac region. We obtained image by $^{201}Tl$ myocardial perfusion SPECT without gate method application and analyzed spatial resolution using Xeleris ver 2.0551. Results: In case of $^{201}Tl$ window and the counts rate comparison result yesterday whole body bone scan of being counted in $^{99m}Tc$ window, the difference in which a rate to 24 hours exponential-functionally notes in 1:0.114 with Ventri (GE Healthcare, Wisconsin, USA), 1:0.249 after the bone tracer injection in 12 hours in 1:0.411 with 1:0.79 with Infinia (GE healthcare, Wisconsin, USA) according to a reduction a time-out was shown (Ventri p=0.001, Infinia p=0.001). Moreover, the rate of the case in which it doesn't perform the whole body bone scan showed up as the average 1:$0.067{\pm}0.6$ of Ventri, and 1:$0.063{\pm}0.7$ of Infinia. According to the phantom after experiment spatial resolution measurement result, and an addition or no and time-out of $^{99m}Tc$ administrated, it doesn't note any change of FWHM (p=0.134). Conclusion: Through the experiments using anthropomorphic torso phantom and patients data, we found that $^{201}Tl$ myocardium perfusion SPECT image later carried out after the bone tracer injection with 16 hours this confirmed that it doesn't receive notable influence in spatial resolution by $^{99m}Tc$. But this investigation is only aimed to image quality, so it needs more investigation in patient's radiation dose and exam accuracy and precision. The exact guideline presentation about the exam interval should be made of the validation test which is exact and in which it is standardized about the affect of the crosstalk contamination according to the isotope use in which it is different later on.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.6
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• pp.421-429
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• 2003

Purpose : Neoadjuvant chemotherapy is commonly used to treat cancer patients as adjunct treatment, but if the microvascular tissue transfer is performed simulataneously with cancer resection surgery, the induction chemotherapy might affect the survival rate of vascularized free flap. Our study will focus on the effect of induction chemotherapy on the free flaps which were made on white rat abdomen after injection of 5-FU. Materials and Methods: The experimental rat groups were divided into three groups (total 24 rats) as a normal control group, 24 hrs group after 5-FU injection, 3 days group after 5-FU injection. Inferior abdominal island flaps of 8 Sprague Dawley rats on each group were made and immediately were induced into an ischemic state by clamping the supplying inferior epigastric artery and vein with microvascular clamp for a hour to induce a similiar free flap circumstance, then the inferior abdominal skin flaps were reperfused by releasing the clamps. The flaps on abdomen were repositioned and sutured. The experimental data for flap survival rate was collected by digital photo taking, analysed by computer image program to compare with the flap luminosity. The rats were sacrificed at 3 days, 5 days, 7 days after flap preparation and specimens of the flap were taken and stained with H-E staining. The microscopic finding was made under magnification of 200 and 400. Results: 1. Gross findings on each groups showed the healing condition was good as following sequences; normal, 24 hrs group after chemotherapy, 3 days group after chemotherpy. 2. The values of flap luminosity for evaluation of flap survival rate also showed the same sequences as gross findings of healing state. 3. The microscopic findings of epidermis necrosis, inflammation state, dermis fibrosis, vessel change, fatty tissue layer thinning were compared with each group. The 3 days group after chemotherapy showed remarkably poor healing condition compared to other groups. Conclusion: Chemotherapy agents affected the healing process of free flap, but healing condition was recovered spontaneously as post-injection periods passed out. In opposite to our expectation, 3 days group showed the bad flap condition in comparing with 24 hours group which was considered as immatured body circulation state of chemotherapy agent. It showed that 3 weeks in human being after chemotherapy was not proper as timing of microvascular tissue transfer if 3 days group in rat was considered as same healing period of 3 weeks in human being. More delayed healing timing than 3 weeks might be required in clinical application of free tissue transfer.

• Journal of Intelligence and Information Systems
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• v.26 no.2
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• pp.131-145
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• 2020

In line with the trend of industrial innovation, IoT technology utilized in a variety of fields is emerging as a key element in creation of new business models and the provision of user-friendly services through the combination of big data. The accumulated data from devices with the Internet-of-Things (IoT) is being used in many ways to build a convenience-based smart system as it can provide customized intelligent systems through user environment and pattern analysis. Recently, it has been applied to innovation in the public domain and has been using it for smart city and smart transportation, such as solving traffic and crime problems using CCTV. In particular, it is necessary to comprehensively consider the easiness of securing real-time service data and the stability of security when planning underground services or establishing movement amount control information system to enhance citizens' or commuters' convenience in circumstances with the congestion of public transportation such as subways, urban railways, etc. However, previous studies that utilize image data have limitations in reducing the performance of object detection under private issue and abnormal conditions. The IoT device-based sensor data used in this study is free from private issue because it does not require identification for individuals, and can be effectively utilized to build intelligent public services for unspecified people. Especially, sensor data stored by the IoT device need not be identified to an individual, and can be effectively utilized for constructing intelligent public services for many and unspecified people as data free form private issue. We utilize the IoT-based infrared sensor devices for an intelligent pedestrian tracking system in metro service which many people use on a daily basis and temperature data measured by sensors are therein transmitted in real time. The experimental environment for collecting data detected in real time from sensors was established for the equally-spaced midpoints of 4×4 upper parts in the ceiling of subway entrances where the actual movement amount of passengers is high, and it measured the temperature change for objects entering and leaving the detection spots. The measured data have gone through a preprocessing in which the reference values for 16 different areas are set and the difference values between the temperatures in 16 distinct areas and their reference values per unit of time are calculated. This corresponds to the methodology that maximizes movement within the detection area. In addition, the size of the data was increased by 10 times in order to more sensitively reflect the difference in temperature by area. For example, if the temperature data collected from the sensor at a given time were 28.5℃, the data analysis was conducted by changing the value to 285. As above, the data collected from sensors have the characteristics of time series data and image data with 4×4 resolution. Reflecting the characteristics of the measured, preprocessed data, we finally propose a hybrid algorithm that combines CNN in superior performance for image classification and LSTM, especially suitable for analyzing time series data, as referred to CNN-LSTM (Convolutional Neural Network-Long Short Term Memory). In the study, the CNN-LSTM algorithm is used to predict the number of passing persons in one of 4×4 detection areas. We verified the validation of the proposed model by taking performance comparison with other artificial intelligence algorithms such as Multi-Layer Perceptron (MLP), Long Short Term Memory (LSTM) and RNN-LSTM (Recurrent Neural Network-Long Short Term Memory). As a result of the experiment, proposed CNN-LSTM hybrid model compared to MLP, LSTM and RNN-LSTM has the best predictive performance. By utilizing the proposed devices and models, it is expected various metro services will be provided with no illegal issue about the personal information such as real-time monitoring of public transport facilities and emergency situation response services on the basis of congestion. However, the data have been collected by selecting one side of the entrances as the subject of analysis, and the data collected for a short period of time have been applied to the prediction. There exists the limitation that the verification of application in other environments needs to be carried out. In the future, it is expected that more reliability will be provided for the proposed model if experimental data is sufficiently collected in various environments or if learning data is further configured by measuring data in other sensors.