• Journal of Korean Society of Forest Science
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• v.112 no.1
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• pp.71-82
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• 2023

Forest biomass is used as a representative indicator of forest size, maturity, and productivity. Therefore, quantitative evaluation is important for management and harvest as well as the evaluation of ecosystem functions and services including CO₂ absorption. The allometric equation is a widely used method for estimating the value of each component through the relative growth rate of plants. Recently, studies indicated that the relative growth of trees is changing because of the increased CO₂ concentration in the atmosphere and the resulting climate change, raising the need to review the previously developed relative growth models and coefficients. In this study, the height-diameter at breast height (DBH) relationships of four major tree species in Korea [(Pinus densiflora (PD), Larix kaempferi (LK), Quercus variabilis (QV), and Quercus mongolica (QM)] were analyzed using the 5th-7th National Forest Inventory (NFI) data. Furthermore, these results were compared with the present yield table from the National Institute for Forest Science. This analysis revealed that the expected height for the same DBH increased as the NFI progressed. For example, in model analysis, the expected heights for PD, LK, QV, and QM for DBH of 25 cm were 12.48, 19.17, 14.47, and 13.19 m, respectively, in the 5th NFI data. In the 7th NFI data, these values were estimated as 13.61 (+9.1%), 21.58 (+12.7%), 15.76 (+8.9%), and 13.93 m (+5.6%), respectively. These results indicate that the major tree species in South Korean forests currently are more vigorous in height growth than in diameter growth when compared to the height-DBH development trends by tree species identified through past survey data.

• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.603-614
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• 2022

This study investigated the characteristics of fish communities in the Bangtaecheon Stream in Korea from April to October 2020. The survey collected 4,640 fish of 26 species in 9 families from 11 survey stations. The dominant and subdominant species were Rhynchocypris kumgangensis(relative abundance at 31.5%) and Zacco koreanus(27.8%), respectively. The next most abundant species were Ladislavia taczanowskii(15.9%), Pungtungia herzi(4.0%), Brachymystax lenok tsinlingensis(3.7%), Microphysogobio longidorsalis(2.4%), and Zacco platypus(2.3%). Among the collected fish species, 17 (65.4%) were Korean endemic species, 4 (15.4%), including Acheilognathus signifer, Pseudopungtungia tenuicorpa, Gobiobotia brevibarba, and B. l. tsinlingensis,were class II endangered wildlife as designated by the Ministry of Environment, and 1 species, Hemibarbus mylodon, was a natural monument. Moreover, two landlocked species (B. l. tsinlingensisand C. koreanus) were also collected. Additionally, four cold-water species (R. kumgangensis, L. taczanowskii, B. l. tsinlingensis,and Cottus koreanus) were collected, and all of them mainly inhabited the upper and middle streams. Fish community analysis showed a tendency for dominance and uniformity to decrease and abundance and diversity to increase from upstream to downstream and that the community structure was divided into upstream and downstream groups. The river health was rated as excellent (9 stations) and good (2 stations). Compared to the previous studies, three species (Carassius auratus, Leiocassis ussuriensis,and Siniperca scherzeri) appeared in the past but did not appear in this survey, and three species (Opsariichthys uncirostris amurensis, Microphysogobio yaluensis,and Orthrias nudus) that did not appear in the past appeared in this survey. Bangtaecheon Steam is well-preserved, and climate-sensitive species, endangered wildlife, and natural monuments inhabit the stream. Therefore, continuous attention and systematic conservation measures are required.

• Journal of Environmental Impact Assessment
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• v.32 no.2
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• pp.123-133
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• 2023

Wastewater generated in the secondary battery production process contains lithium and high-concentration sulfate. Recently, as demand as demand for high-Ni precursors with high-energy density has surged, nickel emission is also a concern. Lithium and sulfate are not included in the current water pollutant discharge standard, so if they are not properly processed and discharged, the negative effect on future environment may be great. Therefore, in this study, the ecotoxicity of lithium, nickel, and sulfate, which are potential contaminants that can be discharged from the secondary battery production process, was evaluated using water flea (Daphnia magna) and luminescent bacteria (Aliivibrio fischeri). As a result of the ecotoxicity test, 24-hour and 48-hour D. magna EC₅₀ values of lithium were 18.2mg/L and 14.5mg/L, nickel EC50 values were 7.2mg/L and 5.4mg/L, and sulfate EC₅₀ values were 4,605.5mg/L and 4,345.0mg/L, respectively. In the case of D. magna, it was found that there was a difference in ecotoxicity according to the contaminants and exposure time (24 hours, 48 hours). Comparing the EC₅₀ of D. magna for lithium, nickel, and sulfate, the EC₅₀ of nickel at 24h and 48h was 39.6-37.2% compared to lithium and 0.1-0.2% compared to sulfate, which was the most toxic among the three substances. The difference appeared to be at a similarlevelregardless of the exposure time. The EC₅₀ of sulfate was 253.0-299.7% and 639.5-804.6%, respectively, compared to lithium and nickel, showing the least toxicity among the three substances. The 30-minute EC₅₀ values of luminescent bacteria forlithium, nickel, and sulfate were 2,755.8mg/L, 7.4mg/L, and 66,047.3mg/L,respectively. Unlike nickel, it was confirmed that there was a difference in sensitivity between D. magna and A. fischeri bacteria to lithium and sulfate. Studies on the mixture toxicity of these substances are needed.

• Journal of Environmental Impact Assessment
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• v.32 no.2
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• pp.134-145
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• 2023

Currently, the floodplains of major rivers are transforming into various types of waterfront spaces according to the increase in leisure activities and improved accessibility. In general, waterfront activities in river channels tend to be concentrated in summer, and the waterfront activities during this period directly affect water quality. Accordingly, it is necessary to accurately compare and evaluate the characteristics and water quality of waterfront activities during the period when waterfront activities are concentrated. In this study, the following research was conducted to compare and analyze the current status of waterfront activities of users of waterfront areas and the water quality of waterfront areas. First, three waterfront areas were selected for investigation using the information from the Ministry of Environment's water quality measurement network. Second, a survey was conducted on the satisfaction and types of waterfront activities targeting users of waterfront areas. Third, water quality grades were calculated based on monthly water quality measurement factors and compared. Fourth, statistical analysis (one-way analysis of variance) was conducted to see if there was a significant difference in water quality characteristics between periods of high waterfront activity and periods of low waterfront activity using water quality measurement data for the last 5 years. As a result of this analysis, the following conclusions were drawn in this study. First, the use of waterfront activities was investigated in the order of camping, water skiing, fishing, swimming, and rafting. Second, satisfaction factors for waterfront activities were investigated in the order of activity convenience, water quality, waterlandscape, transportation access convenience, and temperature. Third, it was found that satisfaction with water quality in waterfront areas was generally unsatisfactory regardless of the water quality grade presented by the competent authority. Fourth, as a result of comparing the water quality measurement network data of the Ministry of Environment by water quality grade, generally good grades were found, and in particular, there was a difference in grade frequency by season in the BOD category. Fifth, as a result of statistical analysis (one-way ANOVA) of water quality monitoring network data by season, there were statistically significant differences in COD, BOD, TP, and TOC except for DO. Considering the results of these studies, it is judged that it is necessary to prepare a comprehensive management system for water quality improvement in the waterfront zone and to improve water quality during periods of high waterfront activity, and to prepare a water quality forecasting system for waterfront areas in the future.

• Korean Journal of Environmental Biology
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• v.40 no.2
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• pp.148-156
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• 2022

Ecological occupation in irrigation ponds is a well-acknowledged fact that is essential for biodiversity conservation in agricultural ecosystems. However, there are few studies on the ecological functions and relationship between a paddy field and irrigation using macroinvertebrates in an environmentally friendly paddy field. The objective of this study is to identify the community and distribution characteristics of macroinvertebrates in an agricultural paddy field and irrigation pond ecosystems, and to provide basic data on the ecological function of an environmentally friendly paddy field. Macroinvertebrate sampling was conducted from May to September in an agricultural paddy field and irrigation pond in an environment-friendly paddy field in Boryeong city. We conducted a study to identify the distribution characteristics using macroinvertebrate species analysis, such as Functional Feeding Groups (FFGs), Habitat Oriented Groups (HOGs), rarefaction curve, and a two-way dendrogram. A total of 37 species of macroinvertebrates in 28 families, 13 orders were collected study during the period of the investigation. Dominant taxa of macroinvertebrates included Coleoptera, Hemiptera, and Odonata. In terms of FFGs, predators and gathering collectors accounted for approximately 70%, in relation to HOGs, and climbers and swimmers occupied more than 50% from both the paddy field and irrigation pond. With respect to the rarefaction curve, the irrigation pond (July) was high as E (S, 141)=18 species, while the paddy field (May) was comparatively low as E (S, 141)=9 species. In conclusion, our results revealed that macroinvertebrates, such as Notonecta triguttata, Peltodytes intermedius, Appasus major, Laccotrephes japonensis, Appasus japonicus, Sigara substriata, Enochrus simulans, and Sternolophus rufipes, were used as a habitat and spawning ground in both paddy field and irrigation pond. The irrigation pond appears to be a very important spawning ground for macroinvertebrates.

• Journal of Service Research and Studies
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• v.13 no.2
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• pp.227-245
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• 2023

As offline company and online·mobile startups meet in an untact shopping environment, competition among companies in untact shopping is increasing. In this situation, companies need their own clear strategy to create customer value. In particular, it is very important to focus on 'customer experience' to establish such a strategy in an untact shopping environment. Customer experience refers to all processes in which consumers meet and experience a company or brand at a touch point. In this processes consumers decide whether to continue to use the company and brand. In this situation, it is thought that it will be meaningful for research to examine the customer experience of untact shopping. Therefore, this study aimed to examine the customer experience of untact shopping, which is used by all generations after COVID-19, through experience quality, and to examine the impact on the expectation-confirmation Model of untact shopping. The results of this study are as follows. First, as a result of examining whether interaction quality, information quality, and outcome quality affect expectation-confirmation it was found that all qualities except interaction quality affect expectation matching. Second, as a result of examining whether interaction quality, information quality, and outcome quality affect perceived usefulness, it was found that all qualities except interaction quality had an effect. Next, as a result of applying the expectation confirmation model to the untact shopping environment and examining whether the expectation confirmation has an effect on use satisfaction, it was found that there was a positive effect. As a result of examining whether perceived usefulness affects use satisfaction, it was found to have a positive effect. As a result of examining whether perceived usefulness affects expectation confirmation, it was found that there is a positive effect. Finally, as a result of examining whether perceived usefulness affects the intention to continue using untact shopping, it was found to be positive. Next, as a result of examining the effect of use satisfaction on trust, it was found that there was a positive effect. Finally, as a result of investigating whether trust has an effect on the intention to continue using, it was found that there is a positive effect. Looking at the important results especially, information quality was found to have the greatest influence.

• Journal of Service Research and Studies
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• v.13 no.2
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• pp.181-203
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• 2023

YouTube exhibits a hybrid personality, incorporating traits of both over-the-top (OTT) and personal broadcasting platforms. However, limited research has investigated these hybrid characteristics, particularly in the context of paid YouTube channel memberships. Therefore, building upon consumption value theory and prior literature, this study examines the influence of consumption value factors associated with paid YouTube channel memberships on usage satisfaction and continuance intention. Specifically, the study identifies four perceived consumption value factors (functional, social, emotional, and epistemic values) within the paid YouTube channel membership context and assesses their impact on usage satisfaction and continuance intention. Additionally, the study explores the moderating role of conditional value (the experience of watching live streams on paid YouTube channels) in these relationships. Data was collected via an online survey from Korean adults who subscribed to multiple paid YouTube channel memberships, resulting in 274 responses. The proposed hypotheses were tested using structural equation modeling (SEM). The SEM results indicate that all four consumption value factors significantly influence usage satisfaction, with usage satisfaction in turn positively affecting continuance intention. Furthermore, the study reveals that conditional value moderates the relationships between functional/emotional values and usage satisfaction, as well as between usage satisfaction and continuance intention. This study is the first to focus on YouTube channel paid memberships, which encompass characteristics from both OTT and personal broadcasting platforms. It is anticipated that this research will offer insights to personal broadcasters and stakeholders regarding the motivational factors that impact user satisfaction and encourage subscriptions to channel memberships.

• Journal of Service Research and Studies
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• v.13 no.2
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• pp.41-61
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• 2023

The universal form of life in the era of the 4th industrial revolution can probably be summarized as the keyword "non-face-to-face". In particular, in terms of consumption activities, face-to-face contact is gradually changing to a system that minimizes, and offline stores are rapidly changing to non-contact services through kiosks and robots. The social structure is also changing with the passage of time, and most fundamentally, our dietary consumption patterns are changing. In particular, the increase in single-person households and the aging population are having a great impact on changes in the food service industry, which is closely related to dietary life. The HMR (Home Meal Replacement) market has grown significantly as the labor of cooking at home has decreased and the use of substitute foods has increased. As the size of the market has grown, the types of businesses that provide products have also diversified. The development of technology, non-face-to-face culture, and corporate management efficiency are intertwined, and unmanned stores are spreading recently. In this study, service quality attributes of HMR unmanned stores, where competition is gradually intensifying, are classified, and service quality classification using the Kano model and Timko's customer satisfaction coefficient are calculated to provide implications for service management based on customer satisfaction. As a result of the analysis, 'products with short cooking time' and 'variety of products (menu)' were classified as attractive qualities, and 'cleanliness inside/outside of the store' and 'products at reasonable prices' were classified as unified quality. In addition, 'convenience of self-checkout process' was classified as a natural quality, and 'convenience of in-store passage' was classified as an indifferent quality. Furthermore, when the service factor was satisfied within the HMR unmanned store, the factor with the highest satisfaction coefficient was 'product (menu) variety', and the factor with the highest dissatisfaction factor was 'convenience of self-checkout process'. Through the results of this study, it is intended to derive priorities in service quality management of HMR unmanned stores and provide strategic implications for related businesses.

• Journal of Service Research and Studies
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• v.13 no.1
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• pp.108-126
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• 2023

This study explored the sustainability of a blockchain-based cultural art performance video platform through the construction of Gyeonggi Art On, a new media art broadcasting station in Gyeonggi-do. In addition, the technical limitations of video content transaction using block chain, legal and institutional issues, and the protection of personal information and intellectual property rights were reviewed. As for the research method, participatory observation methods such as in-depth interviews with developers and operators and participation in meetings were conducted. The researcher participated in and observed the entire development process, including designing and developing blockchain nodes, smart contracts, APIs, UI/UX, and testing interworking between blockchain and content distribution services. Research Question 1: The results of the study on 'Which technology model is suitable for a blockchain-based performance video content distribution public platform?' are as follows. 1) The blockchain type suitable for the public platform for distribution of art performance video contents based on the blockchain is the private type that can be intervened only when the blockchain manager directly invites it. 2) In public platforms such as Gyeonggi ArtOn, among the copyright management model, which is an art based on NFT issuance, and the BC token and cloud-based content distribution model, the model that provides content to external demand organizations through API and uses K-token for fee settlement is suitable. 3) For public platform initial services such as Gyeonggi ArtOn, a closed blockchain that provides services only to users who have been granted the right to use content is suitable. Research question 2: What legal and institutional problems should be reviewed when operating a blockchain-based performance video distribution public platform? The results of the study are as follows. 1) Blockchain-based smart contracts have a party eligibility problem due to the nature of blockchain technology in which the identities of transaction parties may not be revealed. 2) When a security incident occurs in the block chain, it is difficult to recover the loss because it is unclear how to compensate or remedy the user's loss. 3) The concept of default cannot be applied to smart contracts, and even if the obligations under the smart contract have already been fulfilled, the possibility of incomplete performance must be reviewed.

• Journal of Korean Society of Forest Science
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• v.112 no.2
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• pp.157-172
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• 2023

Controlled pollination (CP) is an important method in tree breeding programs because CP quickly generates desirable genotypes and rapidly maximizes genetic gains. However, few studies have evaluated the efficiency and success rate of CP in the breeding program of Pinus densiflora. To evaluate CP and the management of control pollinated progenies, we used 159 individuals in CB2 × KW40 or KW40 × CB2 populations that were established in 2015. After genotyping microsatellite loci, we estimated whether the number of primers was sufficient or not. Then, we performed pedigree analysis. The result showed that the number of primers was sufficient. By pedigree analysis, we found out that 60 of 159 individuals had been generated by the mating between CB2 and KW40. In the maternity analysis, there was evidence to indicate the possibility of management problems. Therefore, we excluded 54 individuals and repeated the pedigree analysis. In the second analysis, 47 of 105 individuals were generated by the mating between CB2 and KW40. To increase the efficiency of CP in tree breeding programs, several precautions are required. It is necessary to identify the exact clone names of the mother and father trees. In addition, CP processes should be performed properly, including deciding on the schedule of CP and the isolation of female strobili or flowers. Finally, the monitoring of hybrid progenies management after mating is important. Molecular markers should be used to identify the clone names of the mother and father trees and for monitoring post hoc management. This study provides a reference for tree breeding programs for the future control pollination of pine species.