• Journal of Korean Society of Forest Science
• /
• v.111 no.2
• /
• pp.302-310
• /
• 2022

Here we aimed to classify the major coniferous tree species (Pinus densiflora, Pinus koraiensis, and Larix kaempferi) by tree measurement information and machine learning algorithms to establish an efficient forest management plan. We used national forest monitoring information amassed over nine years for the measurement information of trees, and random forest (RF), XGBoost (XGB), and light GBM (LGBM) as machine learning algorithms. We compared and evaluated the accuracy of the algorithm through performance evaluation using the accuracy, precision, recall, and F1 score of the algorithm. The RF algorithm had the highest performance evaluation score for all tree species, and highest scores for Pinus densiflora, with an accuracy of about 65%, a precision of about 72%, a recall of about 60%, and an F1 score of about 66%. The classification accuracy for the dominant trees was higher than about 80% in the crown classes, but that of the co-dominant trees, the intermediate trees, and the overtopper trees was evaluated as low. We consider that the results of this study can be used as reference data for decision-making in the selection of thinning trees for forest management.

• Conservation Science in Museum
• /
• v.27
• /
• pp.23-38
• /
• 2022

The standing plaster figure entitled is an early work from Choi Man Lin's 'Eve' series. It reflects the aesthetics of abstract sculpture in the period following Korea's liberation from Japanese colonial rule. Modern and contemporary sculptures can be made from a wide variety of materials, so the particular selection of materials and expressive techniques are indicative of both the artist's intentions and the zeitgeist of the moment. In this regard, the materials and production techniques used in provide important basic data for the chronological study of Choi's artistic development. In this study, scientific analysis was conducted to reveal the production techniques used in the work. The scope of appropriate conservation treatment was decided through consultation between several people with decision-making authority. First, the internal structure was inspected using X-CT scanning, and a material analysis was conducted to identify the formal characteristics, materials, and production techniques found in the work. As the analyses revealed the work to be in a relatively stable state, only minimal conservation treatment was applied based on the opinions expressed by the institution housing the work, by a former assistant of the artist, and in an interview granted by the artist during his lifetime.

• Korean Journal of Environment and Ecology
• /
• v.36 no.2
• /
• pp.202-216
• /
• 2022

Animals exhibit certain behaviors and movement patterns as they react to their internal needs, external stimuli, and surrounding environments. They have a bounded range in which they mostly spend their time, and it is referred to as a home range. Based on the fact that the home range is a critical area for the survival and preservation of species, there has been a growing body of research on developing more precise home range estimation methods to use the estimated ranges as a ground for establishing an effective conservation policy since the early 1940s. Recent rapid advancements in telemetry technology that resulted in the presence of autocorrelation between locations with short time intervals revealed the limitations of the existing estimators. Many novel estimators have been developed to compensate for it by incorporating autocorrelation in calculating home ranges. However, studies on the animal home range are still in their early stage in Korea, and newly developed methodologies have not yet been adopted. Therefore, this study aims to introduce the foreign home range estimation methods and foster domestic research activities on home ranges. Firstly, we compared and contemplated seven estimators by categorizing them into geometrical and statistical methodologies and then divided them into estimators that assume independent observations and those that consider autocorrelation in each category. After that, the home ranges of black-tailed gulls (Larus crassirostris) were calculated using GPS tracking data for the month of June and derived home range estimators by applying the methodology introduced in this study. We analyzed and compared the results to discuss the strengths and weaknesses of each method. Lastly, we proposed a guideline that can help researchers choose an appropriate estimator for home range calculation based on the animal location data characteristics and analysis purpose.

• Journal of Advanced Navigation Technology
• /
• v.26 no.2
• /
• pp.54-62
• /
• 2022

ICAO has recommended data-based aviation safety management and decision-making systems through Annex 19(Safety Management) and Doc 9859(Safety Management Manual), stressing that safety can be greatly improved by sharing aviation safety information throughout the industry. Accordingly, advanced aviation countries have built infrastructure to collect and analyze various aviation safety data in an integrated manner, and also tried to spread identified major safety issues across the industry. On the other hand, in Korea, each stakeholder collects, manages and analyzes safety data individually, so there is a limit to use them in integrative manner. In addition, the scope of using and sharing aviation safety information such as analysis result is also focused on safety management at the national government level, which is insufficient to be shared throughout the industry. Accordingly, the purpose of this study is to present a plan to share and utilize the domestic aviation safety information. To do this, we compare the current situation between FAA and domestic industry and suggest the improvement plans.

• Informatization Policy
• /
• v.29 no.1
• /
• pp.38-59
• /
• 2022

The development of IT technology and the spread of smartphones are having a great impact on businesses and consumers. Consumers have been able to acquire more diverse and larger amounts of information than in the past due to information provided through smartphones and information search on the internet, which has a significant influence on decision-making. Companies have also become sensitive to such changes in consumer behavior patterns, reflected in their marketing. In addition, among the various characteristics of smartphones, location-based technology has become an important factor in providing targeted marketing from a company's point of view. Such technological development and social change have led to the expansion of the mobile advertising market, which promotes products or services based on the location of consumers and provides benefits such as discount coupons. In this study, we have analyzed the influence of consumer characteristics on intention to use in mobile location-based advertising, which has become an important marketing method in the mobile advertising market. The effects of variables of personalization, engagement, coupon proneness, economic efficiency, and irritation on attitude and information privacy concerns were analyzed, and the effects of attitude and information privacy concerns on intention to use were analyzed. The results of this study are deemed to be able to suggest factors to consider when providing mobile location-based advertising to consumers in the future.

• Journal of the Society of Disaster Information
• /
• v.18 no.1
• /
• pp.51-62
• /
• 2022

Purpose: This study analyzes accessibility of outdoor evacuation places for earthquake and the accessibility improvement effects when expanding the evacuation places in accessibility-deficient areas. In order to consider real-world evacuees, the accessibility analysis is based on service population not on resident population. Method: Location-allocation model as a GIS-based spatial optimization mode is used to analyze accessibility and vulnerable areas to evacuation places. Of location-allocation problem types, 'Maximize Coverage' method is chosen to allocate as many potential evacuees as possible to evacuation places. And impedence cutoffs or evacuation distances (times) are applied to three classes: 500m (7.5 minutes), 1,000m (15 minutes), and 1,500m (22.5 minutes). Case study area is Jung-gu areas, Seoul as a high-density downtown area. Result: Results show that accessibility-deficient areas and population to evacuation places are much more in service population than in resident population. Accessibility is significantly improved when increases when expanding the evacuation places in accessibility-deficient areas. Yet, accessibility-deficient areas are still remained since available lands are insufficient in the high-density downtown area. Conclusion: The study suggests that temporary evacuation facilities like outdoor evacuation places for earthquake need to consider real potential evacuees based not only on resident population but also on service population. Also, policy measures to provide emergency shelters need to more utilize spatial optimization tools like location-allocation model.

• Korean Journal of Remote Sensing
• /
• v.38 no.3
• /
• pp.237-250
• /
• 2022

In this study, we propose a method to estimate the biomass of invertebrate grazers from the videos with underwater drones by using a multi-object tracking model based on deep learning. In order to detect invertebrate grazers by classes, we used YOLOv5 (You Only Look Once version 5). For biomass estimation we used DeepSORT (Deep Simple Online and real-time tracking). The performance of each model was evaluated on a workstation with a GPU accelerator. YOLOv5 averaged 0.9 or more mean Average Precision (mAP), and we confirmed it shows about 59 fps at 4 k resolution when using YOLOv5s model and DeepSORT algorithm. Applying the proposed method in the field, there was a tendency to be overestimated by about 28%, but it was confirmed that the level of error was low compared to the biomass estimation using object detection model only. A follow-up study is needed to improve the accuracy for the cases where frame images go out of focus continuously or underwater drones turn rapidly. However,should these issues be improved, it can be utilized in the production of decision support data in the field of invertebrate grazers control and monitoring in the future.

• Journal of the Korean Society of Earth Science Education
• /
• v.15 no.1
• /
• pp.103-116
• /
• 2022

The purpose of this study is to investigate the perception on video material making and the effect on science teaching ability after conducting non-face-to-face teaching material making activity for elementary pre-service teachers. This activity consisted two processes. One is that elementary pre-service teachers conduct inquiry, understand related science concepts, analyze science textbooks and then make video material. The other is that they watch video materials produced by colleagues. This study was conducted on 89 elementary pre-service teachers for 8 weeks. After this activity was completed, the perception on video material making and the effect on science teaching ability of elementary pre-service teachers were investigated, and the results were analyzed. In the process of making and watching non-face-to-face teaching materials, elementary pre-service teachers showed positive results in teaching-learning, video production, and emotion and attitude toward video material making. In addition, it was found that they improved their science teaching ability through this activity and were very satisfied with this activity. However, they also mentioned several disappointments such as exclusion of learners' right to self-determination, lack of various communication channels, and errors in content of materials. This suggests that if these problems are solved, non-face-to-face classes can also be a good form of class.

• Journal of the Society of Disaster Information
• /
• v.18 no.1
• /
• pp.146-153
• /
• 2022

Purpose: In the case of domestic port facilities, port structures that have been in use for a long time have many problems in terms of safety performance and functionality due to the enlargement of ships, increased frequency of use, and the effects of natural disasters due to climate change. A big data analysis method was studied to develop an approximate model that can predict the aging pattern of a port facility based on the maintenance history data of the port facility. Method: In this study, member-level maintenance history data for caisson-type quay walls were collected, defined as big data, and based on the data, a predictive approximation model was derived to estimate the aging pattern and deterioration of the facility at the project level. A state-based aging pattern prediction model generated through Gaussian process (GP) and linear interpolation (SLPT) techniques was proposed, and models suitable for big data utilization were compared and proposed through validation. Result: As a result of examining the suitability of the proposed method, the SLPT method has RMSE of 0.9215 and 0.0648, and the predictive model applied with the SLPT method is considered suitable. Conclusion: Through this study, it is expected that the study of predicting performance degradation of big data-based facilities will become an important system in decision-making regarding maintenance.

• Journal of Korea Port Economic Association
• /
• v.38 no.3
• /
• pp.29-51
• /
• 2022

The International Maritime Organization (IMO) designated the Emission Control Area (ECA) in Northern Europe to reduce the NOx and SOx emissions from ships in the coastal areas. This study used Network slack-based measure (SBM) Data Envelopment Model (DEM) and Bootstrop Truncated Regression (BTR) model to analyze the ECA's impact on ferry companies' financial performances based on the financial data from eight ferry carriers in Northern Europe, the Mediterranean and North America from 2004 to 2017. To alleviate the problem of arbitrary variable selection in DEA, the variable selection criteria proposed by Dyson et al. (2001) were applied; the size of the company was considered through the Network SBM DEA model; and the company's profit-generating process was divided into stages to measure financial performance in more detail. In addition, the BTR model was applied to derive results that minimize the bias of the data. The study found that ECA regulations did not always negatively affect the shipping companies' financial performance. Rather, a steady increase in efficiency was observed for Northern European ferry companies which were subject to the strongest regulations. For North American ferry companies, government subsidies were found to have a significant impact on efficiency, and relatively small impact on efficiency due to the ECA and oil prices. For the Mediterranean ferry companies, efficiency values have decreased since the implementation of ECA regulation despite the lowest level of regulation in the region.