• Journal of Venture Innovation
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• v.7 no.1
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• pp.151-166
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• 2024

The global economic growth rate has been slowed due to changes in the economic and social environment related to the recent trends in the construction market and construction industry, prolonged inflation, intense tensions among countries, and increased interest rates. Since the workers in the construction industry, due to the nature of the industry, move to another site after the completion of an awarded project rather than staying for a long time while performing work at one workplace, various issues are brought out such as poor working environment resulting from unfairness in construction contracts, aging of workers, their anxiety, and job instability. The previous studies on the turnover intention of construction industry workers mainly dealt with external aspects such as leadership, job embeddedness, and organizational citizenship behavior, while the psychological impact was overlooked. The purpose of this study was to develop a measure to reduce or alleviate turnover intention of construction industry workers by verifying empirically the relationship among psychological capital, organizational commitment, and turnover intention among them. For the purpose, whether psychological capital influences organizational commitment and turnover intention, the impact of organizational commitment on turnover intention, and whether organizational commitment has a mediating effect in the relationship between psychological capital and turnover intention, among 310 construction industry workers in the metropolitan area. The results are as follows: First, hope and self-efficacy were found to have a negative (-) effect on turnover intention, while resilience and optimism from psychological capital did not have a significant effect. Second, hope, resilience, and optimism from psychological capital were found to have a positive (+) effect on organizational commitment, while self-efficacy from psychological capital had no significant effect. Third, organizational commitment was found to have a significant mediating effect on the relationship between hope from psychological capital and turnover intention. The results of this study showed that, in construction industry workers, psychological capital affects turnover intention through the mediating effect of organizational commitment. While previous studies mainly considered external influences on the turnover intention of construction industry workers, this study has academic implications in that it sought to strengthen organizational commitment and alleviate turnover intention by approaching psychological aspects. As a practical implication, it was found that higher self-efficacy and hope for work in the organization, from psychological capital, in the construction industry workers were found to lower turnover intention through job performance in a psychologically stable state. It is considered, therefore, that various systems, including job autonomy and flexible work, should be established to improve self-efficacy and hope.

• Industry Promotion Research
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• v.9 no.3
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• pp.57-75
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• 2024

This study examined how ESG activities of convenience stores, affect consumers' store loyalty. Using 300 valid samples of convenience store users collected through an online specialized agency (Company M), this study empirically analyzed the effects of environmental (E), social (S), and governance (G) activities among ESG on trust and store loyalty, and the mediating effects of trust and the moderating effects of eco-friendly values, social media activity, and consumer-company identification. The results of the analysis showed that, first, governance activities had a positive effect on trust, and environmental activities and trust had a positive effect on store loyalty, but social activities had no effect Second, trust had a moderating effect only on the relationship between governance activities and store loyalty, and third, in the relationship between ESG activities and trust, eco-friendly values and social media activity had moderating effects on environmental, social, and governance activities, and consumer-company identification had moderating effects on environmental and governance activities, but not on social activities. Therefore, convenience store brands should further strengthen their environmental and social activities to build consumer trust, especially environmental activities, which only directly affect store loyalty, so they should be more cautious and proactive. In addition, intensive marketing activities are needed to build trust among consumers who have high eco-friendly values, social media activity, and consumer-company identification. Therefore, this study confirms the critical view of consumers despite the social contribution activities of convenience store brands, and suggests that in order to improve them, it is necessary to strengthen social activity efforts, actively participate in ESG activities of on-site franchisees who are customer contact points, and educate employees.

• Economic and Environmental Geology
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• v.57 no.4
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• pp.397-416
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• 2024

This study assessed the hydrogeological properties of the deep geological environment to develop safety criteria for the natural barriers used in the deep geological disposal of high-level radioactive waste in Korea. The assessment focused on the distribution and trends of hydraulic conductivity and permeability properties appropriate for the domestic geological environment, using various in-situ hydraulic test data collected for groundwater development and management. To develop a depth-hydrogeological property relationship model suitable for domestic conditions, the study reviewed various international research examples and applied a representative model that explains the trends of hydraulic conductivity and permeability with depth. The development of the model suitable for Korea involved applying ensemble regression analysis to account for the uncertainty of various factors in the collected data. The results confirmed that existing international depth-hydrogeological property relationship models adequately describe the characteristics of the domestic geological environment. Considering the preferred hydrogeological criteria suggested by countries like Sweden, Germany, and Canada, there is a high likelihood that a suitable geological environment exists in Korea. Additionally, the application of hydrogeological criteria indicative of low-permeability environments showed that suitable conditions for disposal construction increase at depths greater than 300 m, where the influence of fractures on groundwater flow might be minimal at depths exceeding 500 m. This research can serve as foundational information for establishing hydrogeological safety standards for natural barriers in Korea according to international regulatory guidelines.

• Tunnel and Underground Space
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• v.34 no.5
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• pp.503-526
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• 2024

In the research project for the disposal of high-level radioactive waste, where the deep rock environment is considered as the main target for the disposal facilities, the hydrogeological characteristics of rock aquifers are utilized as the most important evaluation factor for the suitability of the disposal site, design/construction of facilities and stability analysis during operation. Such hydrogeological data are obtained by conducting in-situ hydraulic tests using deep boreholes located at the target sites. In this process, the reliability and accuracy of the investigation results are closely linked to various factors including the selection of the optimal testing methods, the performance of testing equipment, the standardization of testing procedures, and data interpretation methods. In this paper, to improve the reliability of the evaluation of hydrogeological characteristics in deep rock aquifers, we conducted a comparative analysis of the hydraulic conductivity characteristics derived from the injection and recovery phases of the most representative hydraulic test, the constant pressure injection test. A high-performance hydraulic testing equipment and standardized testing procedures were applied to deep boreholes in the fractured rock aquifers located in granite/volcanic rock areas in Korea, to obtain the downhole pressure-flow rate, and the hydraulic conductivity was derived by using various transient flow analysis solutions. The results of the study showed a high consistency between the hydraulic conductivity values obtained during the injection and recovery phases within the same test section, even under different permeability conditions (low-permeability/high-permeability). This research case, which precisely conducted a comparative analysis of two different phases (injection/recovery) within a single specific hydraulic testing process using actual field data from deep rock aquifers in Korea, is expected to help overcome the inherent limitations of in-situ field tests, where the validation and verification of measurement results are challenging, and ultimately contribute to enhancing the reliability of deriving in-situ hydrogeological characteristics information.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.366-376
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• 2023

This study was conducted to develop a model for predicting the growth of kimchi cabbage using image data and environmental data. Kimchi cabbages of the 'Cheongmyeong Gaual' variety were planted three times on July 11th, July 19th, and July 27th at a test field located at Pyeongchang-gun, Gangwon-do (37°37' N 128°32' E, 510 elevation), and data on growth, images, and environmental conditions were collected until September 12th. To select key factors for the kimchi cabbage growth prediction model, a correlation analysis was conducted using the collected growth data and meteorological data. The correlation coefficient between fresh weight and growth degree days (GDD) and between fresh weight and integrated solar radiation showed a high correlation coefficient of 0.88. Additionally, fresh weight had significant correlations with height and leaf area of kimchi cabbages, with correlation coefficients of 0.78 and 0.79, respectively. Canopy coverage was selected from the image data and GDD was selected from the environmental data based on references from previous researches. A prediction model for kimchi cabbage of biomass, leaf count, and leaf area was developed by combining GDD, canopy coverage and growth data. Single-factor models, including quadratic, sigmoid, and logistic models, were created and the sigmoid prediction model showed the best explanatory power according to the evaluation results. Developing a multi-factor growth prediction model by combining GDD and canopy coverage resulted in improved determination coefficients of 0.9, 0.95, and 0.89 for biomass, leaf count, and leaf area, respectively, compared to single-factor prediction models. To validate the developed model, validation was conducted and the determination coefficient between measured and predicted fresh weight was 0.91, with an RMSE of 134.2 g, indicating high prediction accuracy. In the past, kimchi cabbage growth prediction was often based on meteorological or image data, which resulted in low predictive accuracy due to the inability to reflect on-site conditions or the heading up of kimchi cabbage. Combining these two prediction methods is expected to enhance the accuracy of crop yield predictions by compensating for the weaknesses of each observation method.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.5
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• pp.65-82
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• 2024

As interest in carbon absorption increases to respond to the global climate crisis, the environmentally friendly design of exterior spaces of apartments, which account for 63.5% of all residences in Korea, is required. In this study, a planting design guideline for increasing the amount of carbon adsorption in the space outside apartments was developed. This is meaningful in suggesting a planting design strategy according to the type of space with the aim of presenting a realistic solution to respond to the climate crisis and carbon output in the domestic construction industry. A carbon calculator was used for the calculation of carbon absorption for trees, and previous research data was used for shrubs and flowers. Based on the laws and regulations related to the exterior space of apartments and design guidelines for each construction company, major landscape spaces were extracted and categorized into central plazas, peripheral forests, waterfront spaces, play and exercise spaces, and small gardens. Apartment complexes in Seoul and the Seoul metropolitan area among the 2021 and later winners of the 'Livable Apartment Award' were selected, and the carbon uptake of landscape trees by space was calculated for more than 1,000 apartments. Based on this, a guideline for planting by space was prepared to increase carbon adsorption. As a result of applying the planting guidelines to the sample target site, the carbon adsorption amount increased by about 5-63% compared to the existing design, and it converged toward the target carbon adsorption amount. This was determined by confirming that the amount of carbon adsorption could increase when planting guidelines were applied. This study is significant for establishing design guidelines by summarizing the carbon absorption data of landscape trees, but it is necessary to secure data on all landscape materials, not just trees, for future carbon reduction design in the landscape field. By presenting practical planting data and design guidelines that can improve carbon absorption in the design and construction of exterior space planting in apartment complexes, this study is significant as basic research that can be utilized as indicators and guidelines for future carbon absorption-related design and is expected to contribute to climate change response in urban environments.

• Korean Journal of Environment and Ecology
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• v.38 no.4
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• pp.375-387
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• 2024

This study investigated the ecological characteristics of Fraxinus chiisanensis Nakai, one of the endemic and rare plant species in Korea, based on its distribution status, characteristics of the growth environment, and species composition. A vegetation survey that analyzed the correlation between species distribution patterns and environmental variables, along with the traits of the emergent plant species, was performed according to the explanation of environmental growth conditions and phytosociological method for the location where F. chiisanensis is found. A total of 19 dominant locations and 9 non-dominant locations of F. chiisanensis were observed in 28 study sites in 12 regions, and a total of 155 taxa were observed. According to the vegetation climate of Korea, the growth environment of the study site where F. chiisanensis is located is characterized as cold and is primarily situated within the northern temperate deciduous broadleaf forest zone. The average elevation was 859m above sea level, with an average rock exposure of 60.4%, soil exposure of 24.7%, and an average slope of 18.7°. The taxa belonging to the top P-NCD(Percentage of Net Contribution Degree) among the emergent species were mostly designated as the taxa emerging in valley vegetation. The correlation analysis of environmental variables revealed that altitude had the strongest correlation, with rock exposure showing the second highest correlation. The ongoing dynamics of the F. chiisanensis forest are anticipated to persist due to the high P-NCD values exhibited by the F. chiisanensis within the shrub and herbaceous layers among the taxa associated with tree species. Most F. chiisanensis habitats are currently situated within protected regions such as national parks, provincial parks, and county parks, where there are relatively minimal human-induced disturbances. However, there is potential for damage in areas not designated as protected, such as forest tending operation sites or new hiking trails. Concerns about declining habitat quality have prompted suggestions for management strategies such as establishing Forest Genetic Resource Reserves in these locations. In addition, follow-up and further research should be conducted to identify possible sites for distribution and establish candidate conservation areas based on various environmental conditions of F. chiisanensis.

• Korean Journal of Environment and Ecology
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• v.38 no.4
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• pp.388-404
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• 2024

The focus of conserving plant diversity at the national level includes endemic species restricted to specific regions. This study thus aimed to investigate and evaluate the current distribution status of the Pulsatilla tongkangensis Y.N. Lee & T.C. Lee, one of Korea's endemic plants. The study also examined the vegetation environment of its habitat and assessed the structure of each population. Furthermore, the performance variable of each population was comparatively evaluated, and its annual growth characteristics were also observed. The distribution area of the P. tongkangensis is largely divided into limestone cliffs, ridge rocks, mountain peaks in limestone regions, and sandy soil areas resulting from weathering. Plants in the same distribution area were categorized based on their geographical location, which reflected their respective habitats. According to the population structure evaluated using the number of measured leaves numbers, the plants were categorized into stable and relatively unstable populations. A relatively young population was observed at the top of mountains and rocky ridges of limestone areas and sandy soil areas resulting from weathering. The number of mature individuals was the highest in the population observed around limestone cliffs. In contrast, the population near the top of the limestone mountain range had more leaves , but the plants were of short stature and had the fewest inflorescences. The individuals distributed in limestone cliffs grew, produced, and dispersed seeds for an extended period following establishment. The growth of individuals was limited due to environmental factors in the habitat of distribution areas, including ridges, mountain tops in limestone regions, and sandy soil areas resulting from weathering. It was assessed to have a comparatively brief life cycle compared to that of the plants found on limestone cliffs. P. tongkangensis began flowering in early spring, and both fruit maturation and seed dispersal were completed before the onset of summer. The habitats were determined to receive around seven hours of sunlight per day during the summer, which was considered suitable for establishing a life cycle for the P. tongkangensis, a species requiring strong sunlight for growth to establish and success in a dry environment. Considering the status data gathered from this study, the P. tongkangensis was classified as an endangered species (EN). In addition, the collected data are expected to provide important information for the IUCN Red List of Threatened Species. Therefore, we proposed that the P. tongkangensis holds significant value as a core distribution site, given the observation of species with diverse characteristics on limestone cliffs in Pyeongchang-gun and Jeongseon-gun, Gangwon-do.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.1286-1288
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• 2024

The construction industry, known for its inherent risks and multiple hazards, necessitates effective solutions for hazard identification and mitigation [1]. To address this need, the implementation of machine learning models specializing in object detection has become increasingly important because this technological approach plays a crucial role in augmenting worker safety by proactively recognizing potential dangers on construction sites [2], [3]. However, the challenge in training these models lies in obtaining accurately labeled datasets, as conventional methods require labor-intensive labeling or costly measurements [4]. To circumvent these challenges, synthetic data generation (SDG) has emerged as a key method for creating realistic and diverse training scenarios [5], [6]. The paper reviews the evolution of synthetic data generation tools, highlighting the shift from earlier solutions like Synthpop and Data Synthesizer to advanced game engines[7]. Among the various gaming platforms, Unity 3D and Unreal Engine stand out due to their advanced capabilities in replicating realistic construction hazard environments [8], [9]. Comparing Unity 3D and Unreal Engine is crucial for evaluating their effectiveness in SDG, aiding developers in selecting the appropriate platform for their needs. For this purpose, this paper conducts a comparative analysis of both engines assessing their ability to create high-fidelity interactive environments. To thoroughly evaluate the suitability of these engines for generating synthetic data in construction site simulations, the focus relies on graphical realism, developer-friendliness, and user interaction capabilities. This evaluation considers these key aspects as they are essential for replicating realistic construction sites, ensuring both high visual fidelity and ease of use for developers. Firstly, graphical realism is crucial for training ML models to recognize the nuanced nature of construction environments. In this aspect, Unreal Engine stands out with its superior graphics quality compared to Unity 3D which typically considered to have less graphical prowess [10]. Secondly, developer-friendliness is vital for those generating synthetic data. Research indicates that Unity 3D is praised for its user-friendly interface and the use of C# scripting, which is widely used in educational settings, making it a popular choice for those new to game development or synthetic data generation. Whereas Unreal Engine, while offering powerful capabilities in terms of realistic graphics, is often viewed as more complex due to its use of C++ scripting and the blueprint system. While the blueprint system is a visual scripting tool that does not require traditional coding, it can be intricate and may present a steeper learning curve, especially for those without prior experience in game development [11]. Lastly, regarding user interaction capabilities, Unity 3D is known for its intuitive interface and versatility, particularly in VR/AR development for various skill levels. In contrast, Unreal Engine, with its advanced graphics and blueprint scripting, is better suited for creating high-end, immersive experiences [12]. Based on current insights, this comparative analysis underscores the user-friendly interface and adaptability of Unity 3D, featuring a built-in perception package that facilitates automatic labeling for SDG [13]. This functionality enhances accessibility and simplifies the SDG process for users. Conversely, Unreal Engine is distinguished by its advanced graphics and realistic rendering capabilities. It offers plugins like EasySynth (which does not provide automatic labeling) and NDDS for SDG [14], [15]. The development complexity associated with Unreal Engine presents challenges for novice users, whereas the more approachable platform of Unity 3D is advantageous for beginners. This research provides an in-depth review of the latest advancements in SDG, shedding light on potential future research and development directions. The study concludes that the integration of such game engines in ML model training markedly enhances hazard recognition and decision-making skills among construction professionals, thereby significantly advancing data acquisition for machine learning in construction safety monitoring.

• Journal of the Korean Society of Radiology
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• v.18 no.6
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• pp.741-747
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• 2024

Cone-Beam Computed Tomography (CBCT) for dental diagnosis has been used for maxillofacial imaging in dental radiology for many years, and increasing in popularity. The number of such inspections increased by approximately 32.4% from 850,000 in 2020 to 1.12 million in 2022. With the increase in dental radiology examinations, the collective effective dose from dental radiology increased by approximately 19.4% from 766 man·Sv in 2020 to approximately 914 man·Sv in 2022. In this study, the effective dose of Cone Beam CT examination was evaluated using Personal Computer(PC)-based computer simulation. The simulation were set identically to the test conditions of the imaging equipment (RCT-820 Ray Co., Ltd.) and compared two methods with Field Of View(FOV) values of 18×16.5 cm and 16×10 cm and an asian adult men phantom was used. The average result at 18×16.5 cm FOV was 223.1 µSv, and the effective dose value at 16×10 cm FOV was averaged at 122.8 µSv. As the irradiation area became smaller, the effective dose value decreased, and the absorbed dose to organ was 1.6 mSv in the 18×16.5 cm FOV, indicating a considerably high tissue equivalent dose. As a result, this study finds the importance of appropriate FOV setting and protective equipment such as a thyroid protector when Cone Beam CT test is performed at a dental site. Also, It is believed that it can be expected that dental medical workers will be able to actively and carefully control irradiation dose settings using the easy-to-use PCXMC program.