• Journal of the Korea Society of Computer and Information
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• v.28 no.10
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• pp.133-153
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• 2023

In this paper, we propose a novel approach to investigating brain-signal measurement technology using Electroencephalography (EEG). Traditionally, researchers have combined EEG signals with bio-signals (BSs) to enhance the classification performance of emotional states. Our objective was to explore the synergistic effects of coupling EEG and BSs, and determine whether the combination of EEG+BS improves the classification accuracy of emotional states compared to using EEG alone or combining EEG with pseudo-random signals (PS) generated arbitrarily by random generators. Employing four feature extraction methods, we examined four combinations: EEG alone, EG+BS, EEG+BS+PS, and EEG+PS, utilizing data from two widely-used open datasets. Emotional states (task versus rest states) were classified using Support Vector Machine (SVM) and Long Short-Term Memory (LSTM) classifiers. Our results revealed that when using the highest accuracy SVM-FFT, the average error rates of EEG+BS were 4.7% and 6.5% higher than those of EEG+PS and EEG alone, respectively. We also conducted a thorough analysis of EEG+BS by combining numerous PSs. The error rate of EEG+BS+PS displayed a V-shaped curve, initially decreasing due to the deep double descent phenomenon, followed by an increase attributed to the curse of dimensionality. Consequently, our findings suggest that the combination of EEG+BS may not always yield promising classification performance.

• Journal of Soil and Groundwater Environment
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• v.28 no.6
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• pp.71-89
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• 2023

A groundwater potential map (GPM) was built for the Nakdonggang River Basin based on ten variables, including hydrogeologic unit, fault-line density, depth to groundwater, distance to surface water, lineament density, slope, stream drainage density, soil drainage, land cover, and annual rainfall. To integrate the thematic layers for GPM, the criteria were first weighted using the Analytic Hierarchical Process (AHP) and then overlaid using the Technique for Ordering Preferences by Similarity to Ideal Solution (TOPSIS) model. Finally, the groundwater potential was categorized into five classes (very high (VH), high (H), moderate (M), low (L), very low (VL)) and verified by examining the specific capacity of individual wells on each class. The wells in the area categorized as VH showed the highest median specific capacity (5.2 m³/day/m), while the wells with specific capacity < 1.39 m³/day/m were distributed in the areas categorized as L or VL. The accuracy of GPM generated in the work looked acceptable, although the specific capacity data were not enough to verify GPM in the studied large watershed. To create GPMs for the determination of high-yield well locations, the resolution and reliability of thematic maps should be improved. Criterion values for groundwater potential should be established when machine learning or statistical models are used in the GPM evaluation process.

• Korea Trade Review
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• v.48 no.4
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• pp.189-208
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• 2023

This paper analyzed the dynamic conditional correlation between the Korean ETS market, energy market and stock market. This paper conducted an empirical analysis using daily data of Korea's carbon credit trading price, WTI crude oil futures price, and KOSPI index from February 2, 2015 to December 30, 2021. First, the volatility of the three markets was analyzed using the GARCH model, and then the dynamic conditional correlations between the three markets were studied using the bivariate DCC-GARCH model. The research results are as follows. First, it was found that the Korean ETS market has a higher rate of return and higher investment risk than the stock market. Second, the yield volatility of the Korean ETS market was found to be most affected by external shocks and least affected by the volatility information of the market itself. Third, the correlation between the Korean ETS market and the stock market was stronger than that of the WTI crude oil futures market. This paper analyzed the correlation between the Korean ETS market, energy market, and stock market and confirmed that the level of financialization in the Korean ETS market is quite low.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.1
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• pp.1-12
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• 2022

This paper examines the influence of the portion of lead investors and investors' status on the investment performance of venture syndication. According to existing literature, multiple investors in VC syndicates can positively impact investment performance by investing both tangible and intangible resources in target companies based on market influence or high visibility. On the other hand, the presence of multiple leaders can cause conflicts in formulating and implementing investment strategy or free-riding problems or increase entry barriers for potential investors, lowering additional investment from existing investors. Therefore, we hypothesize that the relationship between proportion of lead investors and investment performance is inverted-U shape. Moreover, we predict that the status of VCs in the syndication will moderate the relationship between proportion of lead investors and investment performance since high-status actors are less likely to cooperate with or yield power to others. We tested these hypotheses using 24,677 VC syndicated investment data from 1991 to 2005 and found solid supports for the hypotheses. The findings suggest that firms need to consider relationship-based power dynamics among investors within a syndication and design effective role setting and coordination systems.

• Animal Bioscience
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• v.37 no.5
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• pp.795-806
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• 2024

Objective: Karan Fries (KF), a high-producing composite cattle was developed through crossing indicine Tharparkar cows with taurine bulls (Holstein Friesian, Brown Swiss, and Jersey), to increase the milk yield across India. This composite cattle population must maintain sufficient genetic diversity for long-term development and breed improvement in the coming years. The level of linkage disequilibrium (LD) measures the influence of population genetic forces on the genomic structure and provides insights into the evolutionary history of populations, while the decay of LD is important in understanding the limits of genome-wide association studies for a population. Effective population size (N_e) which is genomically based on LD accumulated over the course of previous generations, is a valuable tool for e valuation of the genetic diversity and level of inbreeding. The present study was undertaken to understand KF population dynamics through the estimation of N_e and LD for the long-term sustainability of these breeds. Methods: The present study included 96 KF samples genotyped using Illumina HDBovine array to estimate the effective population and examine the LD pattern. The genotype data were also obtained for other crossbreds (Santa Gertrudis, Brangus, and Beefmaster) and Holstein Friesian cattle for comparison purposes. Results: The average LD between single nucleotide polymorphisms (SNPs) was r² = 0.13 in the present study. LD decay (r² = 0.2) was observed at 40 kb inter-marker distance, indicating a panel with 62,765 SNPs was sufficient for genomic breeding value estimation in KF cattle. The pedigree-based N_e of KF was determined to be 78, while the N_e estimates obtained using LD-based methods were 52 (SNeP) and 219 (genetic optimization for N_e estimation), respectively. Conclusion: KF cattle have an N_e exceeding the FAO's minimum recommended level of 50, which was desirable. The study also revealed significant population dynamics of KF cattle and increased our understanding of devising suitable breeding strategies for long-term sustainable development.

• Information Systems Review
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• v.24 no.1
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• pp.1-19
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• 2022

Social media-based communication has become crucial part of our personal and official lives. Therefore, it is no surprise that social media sentiment analysis has emerged an important way of detecting potential customers' sentiment trends for all kinds of companies. However, social media sentiment analysis suffers from huge number of sentiment features obtained in the process of conducting the sentiment analysis. In this sense, this study proposes a novel method by using Bayesian Network. In this model MBFS (Markov Blanket-based Feature Selection) is used to reduce the number of sentiment features. To show the validity of our proposed model, we utilized online review data from Yelp, a famous social media about restaurant, bars, beauty salons evaluation and recommendation. We used a number of benchmarking feature selection methods like correlation-based feature selection, information gain, and gain ratio. A number of machine learning classifiers were also used for our validation tasks, like TAN, NBN, Sons & Spouses BN (Bayesian Network), Augmented Markov Blanket. Furthermore, we conducted Bayesian Network-based what-if analysis to see how the knowledge map between target node and related explanatory nodes could yield meaningful glimpse into what is going on in sentiments underlying the target dataset.

• Food Science and Preservation
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• v.30 no.5
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• pp.868-874
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• 2023

This study aimed to investigate the drying characteristics of Caragana sinica Rehder flowers, which are basic data necessary for increasing utilization. The flowers were harvested in mid-April and dried at different hot-air temperatures (50-90℃), and the physicochemical properties of the dried flowers were analyzed. It was found that the drying rate was proportional to the air temperature. The visual color of dried flowers was relatively strong in green when dried at 50℃, while browning was relatively severe when dried at 90℃. The greenness (-a^* value) of the mechanical color of the powder decreased with increasing temperature, and the yellowness (b^* value) decreased with increasing temperature above 70℃. The soluble solids of the hot water extract were maintained at a certain level after increasing up to 70℃, and the pH decreased with increasing temperature. The total polyphenol contents tended to increase with increasing temperature, and DPPH radical scavenging activity did not show a significant change after increasing up to 70℃. These results suggest that the hot-air drying temperature had a significant effect on the physicochemical characteristics of the C. sinica flower. The appropriate hot-air drying temperature was judged to be less than 50℃ for maintaining the unique color, and approximately 70℃ considering the high hot-water extraction yield and antioxidant capacity.

• Information Systems Review
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• v.20 no.4
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• pp.59-78
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• 2018

With the advent of the various device types and marketing communication, customer's search and purchase behavior have become more complex and segmented. However, extant research on multichannel marketing effects of the purchase funnel has not reflected the specific features of device User Interface (UI) and User Experience (UX). In this study, we analyzed the marketing channel effects of multi-device shoppers using a unique click stream dataset from global online retailers. We examined device types that activate online shopping and compared the differences between marketing channels that promote visits. In addition, we estimated the direct and indirect effects on visits and purchase revenue through customer's accumulated experience and channel conversions. The findings indicate that the same customer selects a different marketing channel according to the device selection. These results can help retailers gain a better understanding of customers' decision-making process in multi-marketing channel environment and devise the optimal strategy taking into account various device types. Our empirical analyses yield business implications based on the significant results from global big data analytics and contribute academically meaningful theoretical framework using an economic model. We also provide strategic insights attributed to the practical value of an online marketing manager.

• Journal of Practical Agriculture & Fisheries Research
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• v.26 no.2
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• pp.31-40
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• 2024

This study was indicated that both potato leaves and stems contained certain amount of alkaloids compounds which digested in the rumen of Hanwoo steers. Three candidate plant byproducts such as potato, tomato, and eggplant were collected and dried for making feed additives. Among the candidate byproducts, potato extract was contained 2.05±0.27mg/g of α-chaconine and 0.60±0.08mg/g of α-solanine. These glycoalkaloids was potentially activated as functional compounds to skeletal muscle in beef cattle. However, tomato and eggplant byproducts were not detected any alkaloids compounds. After potato byproducts collected and dried for 24 hours, dry matter of potato byproduct were used as feeding study for evaluating active dose titrations. For evaluating dietary rate of rumen microbes, potato dry matter were treated with in situ hybridization for 72 hours using annulated Hanwoo steers. The glycoalkaloids contained potato dry matter were digested until 12 hours after treatment. Blood concentration of glycoalkaloids were not detected after 24 hours treatment of potato dry matter. These data indicated that potato byproduct were digested with rumen microbes for 24 hours after treatments.

• The Journal of the Convergence on Culture Technology
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• v.10 no.4
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• pp.41-46
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• 2024

In this study, we sought to confirm the potential of the Chaetomorpha torta extract as a raw material for cosmetics. Accordingly, we sought to find the optimal extraction conditions for Chaetomorpha torta by ethanol concentration and to check whether it has an anti-inflammatory effect by confirming the inhibitory effect of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6). The main contents of the experiment results are as follows. First, when DPPH radical scavenging ability and polyphenol yield were used as the criteria for optimal extraction conditions of Chaetomorpha torta, 70% concentration ethanol extract was most suitable. Second, as a result of cytotoxicity evaluation using Raw 264.7, no cytotoxicity was observed at concentrations below 100 ㎍/mL. Third, as a result of measuring the inhibitory effect of pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 in LPS-induced Raw 264.7 cells, the production of all cytokines decreased in proportion to the concentration, and 100 ㎍/mL It was confirmed that the concentrations were 73.76±2.6%, 84.8±2.42%, and 91.91±0.47%, respectively, showing excellent anti-inflammatory properties. According to these research results, it appears that the extract of the Chaetomorpha torta can be valuable as a raw material for cosmetics with anti-inflammatory properties, and if research on antioxidant, antibacterial, and anti-inflammatory activities related to green algae is conducted more actively, marine resources can be used as useful basic data. It is believed that it will be.