• Journal of Korea Game Society
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• v.22 no.1
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• pp.33-42
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• 2022

In online games, interactions with other players may threaten player satisfaction. Therefore, matching players of similar skill levels is important for players' experience. However, with the current evaluation method which is only based on the final result of the game, newbies and returning players are difficult to be matched properly. In this study, we propose a method to improve matchmaking quality. We build machine learning models to predict the MMR of players and derive the basis of the prediction. The error of the best model was 40.4% of the average MMR range, confirming that the proposed method can immediately place players in a league close to their current skill level. In addition, the basis of predictions may help players to accept the result.

• Journal of Animal Science and Technology
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• v.65 no.3
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• pp.490-510
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• 2023

Feed safety is needed to produce and provide safe animal feeds for consumers, animals, and the environment. Although feed safety regulations have been set for each country, there is a lack of clear feed safety regulations for each livestock. Feed safety regulations are mainly focused on heavy metals, mycotoxins, and pesticides. Each country has different safe levels of hazardous materials in diets. Safe levels of hazardous materials in diets are mostly set for mixed diets of general livestock. Although there is a difference in the metabolism of toxic materials among animals, the safe level of feed is not specific for individual animals. Therefore, standardized animal testing methods and toxicity studies for each animal are needed to determine the correct safe and toxic levels of hazardous materials in diets. If this goal is achieved, it will be possible to improve livestock productivity, health, and product safety by establishing appropriate feed safety regulations. It will also provide an opportunity to secure consumer confidence in feed and livestock products. Therefore, it is necessary to establish a scientific feed safety evaluation system suitable for each country's environment. The chance of outbreaks of new hazardous materials is increasing. Thus, to set up appropriate toxic levels or safe levels in feed, various toxicity methods have been used to determine toxic levels of hazardous materials for humans and animals. Appropriate toxic testing methods should be developed and used to accurately set up and identify toxicity and safe levels in food and feed.

• International Journal of Advanced Culture Technology
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• v.11 no.2
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• pp.389-396
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• 2023

This paper selects 100 IT companies listed on the Shenzhen Stock Exchange from 2016 to 2020, and the public announcement in Hwajung collects ESG integrated ratings and grades for each sector and empirically verifies the relationship between ESG ratings and stock returns. Huazheng ESG level data and QIANZHAN database Using corporate financial data, a total of 500 samples were selected through correlation analysis and linear regression analysis with SPSS23 to analyze the effect of ESG on Return. As a result of the analysis, first, the impact on stock returns was found to be a significant positive (+) value for ESG integrated ratings and ratings by E (environment), S (social), and G (governance) sectors, confirming that ESG ratings have a positive mold of corporate stock returns. Currently, the world's major economies have proposed sustainable development strategies and "carbon neutral" goals. Development strategies are very consistent with ESG concepts, and companies that agree and execute ESG concepts may have higher ratings than other companies in the same industry, resulting in certain evaluation premiums. In addition, capital market performance in recent years shows that companies with ESG concepts or "carbon neutrality" concepts are generally considered to have higher growth potential and stronger anti-risk capabilities in the market. For listed companies, they should focus on ESG investment, improve ESG performance, and actively disclose related information to investors. Improving ESG performance should deliver positive information to society, enhance corporate image, increase market confidence in the future development of listed companies, and positively improve corporate value to actively increase financial, financial, trading, and other aspects of negotiation.

• Smart Structures and Systems
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• v.33 no.3
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• pp.177-188
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• 2024

The fatigue-induced sequential failure of a structure having structural redundancy requires system-level analysis to account for stress redistribution. System reliability-based design optimization (SRBDO) for preventing fatigue-initiated structural failure is numerically costly owing to the inclusion of probabilistic constraints. This study incorporates the Branch-and-Bound method employing system reliability Bounds (termed the B³ method), a failure-path structural system reliability analysis approach, with a metaheuristic optimization algorithm, namely grey wolf optimization (GWO), to obtain the optimal design of structures under fatigue-induced system failure. To further improve the efficiency of this new optimization framework, an additional bounding rule is proposed in the context of SRBDO against fatigue using the B³ method. To demonstrate the proposed method, it is applied to complex problems, a multilayer Daniels system and a three-dimensional tripod jacket structure. The system failure probability of the optimal design is confirmed to be below the target threshold and verified using Monte Carlo simulation. At earlier stages of the optimization, a smaller number of limit-state function evaluation is required, which increases the efficiency. In addition, the proposed method can allocate limited materials throughout the structure optimally so that the optimally-designed structure has a relatively large number of failure paths with similar failure probability.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.247-254
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• 2024

To enhance the overall well-being of individuals, acquiring only a quantitative inventory of the individual infrastructure is insufficient and comprehending public perspectives on service levels and infrastructure needs is equally important. This study presents a model for infrastructure service quality that considers the various needs of residents. The study examined the significance and appropriateness of infrastructure service indices in determining the priorities and objectives of government investment in infrastructures. The primary objective was to construct and authenticate a multidimensional model of infrastructure service quality, building on the SERVQUAL framework established in 1988. A survey was distributed to individuals residing in Korea, and 12,500 completed questionnaires were collected. In this study, we conduct a path analysis to test our hypotheses using the AMOS software (version 29.0). The findings of the study indicate that residential satisfaction has a considerable impact on the quality of life. Additionally, this study indicates that the level of infrastructure performance in a residential area has a substantial impact on people's satisfaction with their housing. Furthermore, the findings indicate that it is crucial to address both the quantitative and qualitative dimensions of infrastructure simultaneously. Finally, the evaluation of the efficacy of infrastructure enhancement investments should consider the quality of the infrastructure services.

• Korean Journal of Construction Engineering and Management
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• v.21 no.2
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• pp.79-87
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• 2020

The Korean domestic construction management at risk (CMAR) market is in the process of completing the pilot project execution under the leadership of the Ministry of Land, Infrastructure and Transport as of December 2019. The government starts practicing CMAR an alternative delivery method widely in order to diversify delivery methods and enhance construction technology. The CMAR market is thus expected to grow. This study was conducted to improve CMAR firms' capability by developing self-assessment tools for them to evaluate current capability more effectively. As a result of defining standard core capability and additional elements categorized by project execution phase and management area, and performing evaluation from the CMAR project participants, it was found that the general project management capability in the pre-design and procurement phase and quality management area was lower compared to the construction phase and other areas. In addition, the capability of cost management area was lower in spite of its high importance. Communication and coordination, process optimization, and target values achievement were at the initial level of capability and continuous improvement was required.

• Molecular & Cellular Toxicology
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• v.2 no.2
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• pp.126-133
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• 2006

Thioacetamide (TA) is well known hepatotoxic and hepatocarcinogenic agent. TA also diminishes the contents of hepatic cytochrome P450 and inhibits the enzyme activity of the hepatic mixed function oxidases. TA metabolite, thioacetamide-s-oxide, is further transformed into a still unknown highly reactive metabolite that binds to macromolecules. In this study, we focused on TA-induced gene expression at hepatotoxic dose. Mice were exposed to two levels (5 mg/kg or 50 mg/kg i.p.) of TA, sampled at 6 or 24 h, and hepatic gene expression levels were determined to evaluate dose and time dependent changes. We evaluated hepatotoxicity by serum AST and ALT level and histopathological observation. Mean serum activities of the liver leakage enzymes, AST and ALT, were slightly increased compare to control. H & E and PAS evaluation of stained liver sections revealed TA-associated histopathological finding in mice. Centrilobular eosinophilic degeneration was observed at high dose-treated mice group. Hepatic gene expression was analyzed by QT clustering. Clustering of high dose-treated samples with TA-suggests that gene expressional changes could be associated from toxicity as measured by traditional biomarkers in this acute study.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.1
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• pp.129-137
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• 2018

Objective: The objective of this research was to evaluate the physico-chemical, microbiological and sensorial qualities of restructured steaks processed from beef trimmings (grade I and II) and frozen beef (fresh beef as control and frozen beef). Methods: Beef trimmings from commercial butcher were collected, designated into 4 treatments differing in beef trimmings grade and freezing, processed into restructured steaks with 1% microbial transglutaminase and then analyzed for product quality. Results: The results showed that all meat from different groups could be tightly bound together via cross-linking of myosin heavy chain and actin as observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Microbial counts of psychrotrophic and mesophilic bacteria were not affected by treatments (p>0.05), and no detectable of thermophilic bacteria were found. Regarding effect of beef trimmings grade, steaks made from beef trimmings grade II (16.03% fat) showed some superior sensorial qualities including higher tenderness score (p<0.05) and tendency for higher scores of juiciness and overall acceptability (p<0.07) than those made from beef trimmings grade I (2.15% fat). Moreover, a hardness value from texture profile analysis was lower in steaks processed from beef trimmings grade II than those made from grade I (p<0.05). Although some inferior qualities in terms of cooking loss and discoloration after cooking were higher in steaks made from beef trimmings grade II than those made from beef trimmings grade I (p<0.05), these differences did not affect the sensory evaluation. Frozen beef improved the soft texture and resulted in effective meat binding as considered by higher cohesiveness and springiness of the raw restructured product as compared to fresh beef (p<0.05). Conclusion: The results indicated the most suitable raw beef for producing restructured steaks without detrimental effect on product quality was beef trimmings grade II containing up to 17% fat which positively affected the sensory quality and that frozen beef trimmings increased tenderness and meat binding of restructured beef steaks.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.537-540
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• 2009

Bactericidal efficacies of various sanitizers and disinfectants against 10 Bacillus cereus strains isolated from Korean foods and 8 standard B. cereus strains were investigated. The sanitizing capabilities of ethanol, iodine, chloride, quaternary ammonium, hydrogen peroxide, and peroxide acetic acid were investigated using the EN 1276 method based on quantitative suspension testing. The resistance against sanitizers and disinfectants was higher for wild-type than standard strains, and the bactericidal activities decreased in dirty conditions. Ethanol, chlorine, and iodine at the maximum level allowed under Korean food sanitation laws showed a great effectiveness against B. cereus. Hydrogen peroxide at 1,100 ppm showed the lowest bactericidal activity against B. cereus. These results indicate that the legally allowed maximum concentrations of sanitizers and disinfectants in Korea do not reduce all B. cereus strains by at least $5\;{\log}_{10}\;CFU/mL$.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1394-1398
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• 1998

Lactobacillus bulgaricus LBS 47 and Saccharomyces serevisiae SCS 5 were selected for pure culture inoculation in the fermentation. The effects of stabilizers on the sedimentation, sensory evaluation and viscosity were investigated during fermentation of traditional Andong sikhe. Among the stabilizers added to the traditional Andong sikhe the Na-alginate appeared to be the best. When the product was evaluated by the sensory panel, the addition of stabilizers up to 0.1 % level actually increased the acceptability of the product, while the concentration of more than 0.2% stabilizers affected the acceptability negatively. The viscosity of the product fermented with the CMC and Na-alginate addition reached the maximum on the 2nd day of fermentation, while that of the homogenized Andong sikhe fermented with carrageenan reached the peak on the first day of fermentation.