• The Journal of Information Systems
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• v.30 no.4
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• pp.21-42
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• 2021

Purpose In order for companies to continue to grow, they should properly manage human resources, which are the core of corporate competitiveness. Employee turnover means the loss of talent in the workforce. When an employee voluntarily leaves his or her company, it will lose hiring and training cost and lead to the withdrawal of key personnel and new costs to train a new employee. From an employee's viewpoint, moving to another company is also risky because it can be time consuming and costly. Therefore, in order to reduce the social and economic costs caused by employee turnover, it is necessary to accurately predict employee turnover intention, identify the factors affecting employee turnover, and manage them appropriately in the company. Design/methodology/approach Prior studies have mainly used logistic regression and decision trees, which have explanatory power but poor predictive accuracy. In order to develop a more accurate prediction model, XGBoost is proposed as the classification technique. Then, to compensate for the lack of explainability, SHAP, one of the XAI techniques, is applied. As a result, the prediction accuracy of the proposed model is improved compared to the conventional methods such as LOGIT and Decision Trees. By applying SHAP to the proposed model, the factors affecting the overall employee turnover intention as well as a specific sample's turnover intention are identified. Findings Experimental results show that the prediction accuracy of XGBoost is superior to that of logistic regression and decision trees. Using SHAP, we find that jobseeking, annuity, eng_test, comm_temp, seti_dev, seti_money, equl_ablt, and sati_safe significantly affect overall employee turnover intention. In addition, it is confirmed that the factors affecting an individual's turnover intention are more diverse. Our research findings imply that companies should adopt a personalized approach for each employee in order to effectively prevent his or her turnover.

• Fisheries and Aquatic Sciences
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• v.25 no.5
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• pp.264-275
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• 2022

A non-destructive environmental DNA protocol for the genetic analysis of sea cucumber (Apostichopus japonicus) resources DNA was established. Among the several commercial DNA extraction kits, the DNeasy^® Plant Mini Kit was selected as the best choice to obtain the high-quality genomic DNAs from the mucous sea cucumber. As the temperature and incubation time increased, the amount of extracted environmental DNA was also large, but it was judged that the increased amount did not affect as much as 2-3 times. Therefore, these conditions were not considered to be the main factors to consider in actual environmental DNA extraction. However, the amount of seawater relative to the size of the sample was judged as a major consideration, and a sufficient amount of environmental DNA for analysis was secured when stored within 1 min while stirring the volume of seawater corresponding to the total sea cucumber weight (g). In securing the environmental DNA of sea cucumbers, the mortality rate of sea cucumbers in all experiments was 0, and it was judged that the effects of sea cucumbers were not significant through this treatment. Through the results of this study, sea cucumber DNA research, which has been conducted in a destructive method, can be conducted non-destructively through environmental DNA analysis. Through this study, we have secured a standard protocol that can successfully extract the sea cucumber DNA through environmental DNA. It is not only excellent in terms of time and cost of traditional DNA analysis method currently used, but it is completely non-destructive in the ecosystem of the survey area. It is believed that the system can be transformed in a way that does not affect it. However, it is thought that various standard protocols should be established considering the characteristics of each type.

• Journal of Drive and Control
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• v.19 no.4
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• pp.46-53
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• 2022

RIn this study, a test tractor that could measure various types of agricultural operational loads was developed, and its performance was verified. This tractor could be used to measure the load generated during agricultural work and convert the related data into a database. A test tractor was developed using an 80-kW-rated load tractor, and it could measure various types of field test data, such as engine torque and rpm, wheel torque, PTO(power take-off) torque, hexometer, IMU/INS sensor, steering angle sensor, hydraulic pressure, and flow sensor data. To verify the developed test tractor, a verification test using an agriculture rotavator was performed. The test conditions were L1, L2, and L3 based on the tractor's main and sub-transmission stages, and stages 1 and 2 were selected as the PTO. In a comparison of the analyzed test data, similar tendencies in the test results of this research and other research (Kim's research) were seen. Through this, the developed test tractor was verified. In the future, we plan to conduct research on the tractor developed in this study using various attached working machines.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.4
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• pp.40-47
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• 2022

The present study aimed to examine the effectiveness of different techniques for controlling the diagonal cracks at the corners of openings on the strength, deformation, and crack propagation in reinforced concrete walls. The crack control strip proposed in this study, the conventional diagonal steel reinforcing bars, and stress-dispersion curved plates were investigated for controlling the diagonal cracks at the opening corners. An additional crack self-healing function was also considered for the crack control strip. To evaluate the volume change ratio and crack width propagation around the opening, downsized wall specimens with a opening were tested under the diagonal shear force at the opening corner. Test result showed that the proposed crack control strip was more effective in reducing the volume change and controlling the crack width around the opening when compared to the conventional previous methods. The crack control strip with crack healing feature displayed the superior performance in improving the strength of the wall and reducing the crack width while healing cracks occurred in the previous tests.

• The Korean Journal of Zoology
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• v.11 no.1
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• pp.13-21
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• 1968

1. The authors have collected 40 species of fresh-water fishes at 10 streams located at east side area of Taebaik Mountain Chain, from Songhyon-ri, Hyonnae-myon, Kosung-Kun, Kangwon-do to Chodang cave, Koenduck-myon, Samchok-kun, Kangwon-do from May 25, 1966 to August 30, 1967. 2. Of 40 species 14 are not distributed in the Han River, another 17 are not found in northern part of Wonsan and 11 are not distributed in southern part of Woolchin located at east coast of Korea. 3. Thirty-three species of northern fresh-water fishes, 16 of southern species and 60 of the Han River species were not distributed in the studied area. 4. We consider that the studied area should be included intermediate district of Amur and China subregion. We also believe that the difference of the fish fauna of the studied area and northern part, southern part and the Han River is originated by ecological and geohistorical factors. 5. We consider that Ganthopogon strigatus, Cobitis rotundicaudata, Coreoperca kawamebari, Leucopsarion petersi are distributed in the studied area are remarkable facts. On the other hand, it was quite strange that Gobiogobio, Pseudorasbora parva, Zacco paltypus, Zacco temmincki are not found in the area.

• Journal of Korean Society of Rural Planning
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• v.29 no.4
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• pp.137-152
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• 2023

Data is indispensable for digital transformation of agriculture with the development of innovative information and communication technology (ICT). In order to devise and prioritize strategies for enhancing data competitiveness in the agricultural sector, we employed an Analytic Hierarchy Process (AHP) analysis. Drawing from existing research on data competitiveness indicators, we developed a three-tier decision-making structure reflecting unique characteristics of the agricultural sector such as farmers'awareness of the data industry or awareness of agriculture among data workers. AHP survey was administered to experts from both agricultural and non-agricultural sectors with a high understanding of data. The overall composite importance, derived from the respondents, was rated in the following order: 'Employment Support', 'Data Standardization', 'R&D Support', 'Start-up Ecosystem Support', 'Relaxation of Regulations', 'Legislation', and 'Data Analytics and Utilization Technology'. In the case of experts in the agricultural sector, 'Employment Support' was ranked as the top priorities, and 'Legislation', 'Undergrad and Grad Education', and 'In-house Training' were also regarded as highly important. On the other hand, experts in the non-agricultural sector perceived 'Data Standardization' and 'Relaxation of Regulations' as the top two priorities, and 'Data Center' and 'Open Public Data' were also highly rated.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.2
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• pp.186-191
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• 2024

In this study, we analyzed the nutritional compositions of five species of flounder inhabiting Korean coastal waters. In terms of proximate composition, the moisture and crude fat contents of flounders ranged from 75.16±0.37 to 79.94±0.09 g/100 g and 0.48±0.02 to 4.07±0.09 g/100 g, respectively, and showed a negative correlation. Crude protein contents among the five species were found to range from 18.74±0.37 to 19.69±0.44 g/100 g and showed no significant inter-species differences. Among these flounders, Clidoderma asperrimum was characterized by the highest crude fat and total fatty acid contents of 4.07±0.09 g/100 g and 2,739.39 mg/100 g, respectively, as well as the highest content of polyunsaturated fatty acids, including EPA and DHA, at 620.24 mg/100 g. Hippoglossoides dubius was found to have a total amino acid content of 18,971.36 mg/100 g. Our finding in this study regarding the nutritional profiles of flounders will provide valuable information for industrial use.

• Smart Media Journal
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• v.13 no.4
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• pp.23-32
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• 2024

Large-scale fires and their consequential damages are becoming increasingly common, but confidence in fire detection systems is waning. Recently, widely-used chemical fire detectors frequently generate lots of false alarms, while video-based deep learning fire detection is hampered by its time-consuming and expensive nature. To tackle these issues, this study proposes a fire detection model utilizing an autoencoder approach. The objective is to minimize false alarms while achieving swift and precise fire detection. The proposed model, employing an autoencoder methodology, can exclusively learn from normal data without the need for fire-related data, thus enhancing its adaptability to diverse environments. By amalgamating data from five distinct sensors, it facilitates rapid and accurate fire detection. Through experiments with various hyperparameter combinations, the proposed model demonstrated that out of 14 scenarios, only one encountered false alarm issues. Experimental results underscore its potential to curtail fire-related losses and bolster the reliability of fire detection systems.

• Journal of the Korean Chemical Society
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• v.36 no.2
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• pp.318-323
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• 1992

Following seven new nucleophilic adducts of sulfilimine compounds were prepared by the addition of 1-methyl-5-mercapto-1,2,3,4-tetrazole to vinylsulfilimine derivatives; S-Phenyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine, S-p-tolyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine, S-m-tolyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine, S-p-chlorophenyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine, S-p-bromophenyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine, S-p-methoxyphenyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine and S-p-nitrophenyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine. The structures of these adducts were confirmed by elemental analyses, MP, UV, IR-and NMR-Spectra.

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.708-714
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• 2011

Wood store carbon that the forest absorbed until burned or decomposed over a long period. Such materials are most used in houses except in paper and pulp, and the use of wood in houses play an important role in reducing green-house gases. Therefore, we estimated the amount of carbon stocks in Korean houses, and analyzed how much contribution such stocks offers to green-house gas reduction. As the result, the carbon stocks amount of the wood products in Korean houses was 28.4 million $tCO_2$, which is 4.6% of the total annual green-house gas emission in Korea (620 million $tCO_2$ e), and 77.4% of forest sinks (LULUCF). Even though few wooden houses which use most wood in housing exist in Korea, the carbon stocks of wood products in houses in 2010 increased to 4.1 times that in 1975 (21.4 million $tCO_2$) because the carbon stocks increased due to apartment construction, which hit its stride from the last 1980's.