• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.5
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• pp.671-679
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• 2022

Harmful factors such as shock waves and fragments are generated at domestic ammunition testing sites and military shell shooting training sites due to frequent shooting and explosion tests. As a result, complaints from local residents are rapidly increasing, and there is a high risk of damage to facilities and human life. The recently constructed ammunition test site built a test facility for firing artillery and rocket propulsion in a narrow area with a radius of 300 m due to site restrictions, but damage to the facility is accumulating because there is no adequate protective structure. Therefore, in this study, quantitative data on harmful factors such as noise, vibration, shock wave, and thermal effect generated between artillery firing and rocket propulsion tests were measured, and explosion pressure characteristics were analyzed to design a protective structure, and use Autodyn to protect performance. to perform verification.

• Journal of Advanced Navigation Technology
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• v.26 no.4
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• pp.185-194
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• 2022

Avionics equipment requires various environmental conditions and performance during development, and as a countermeasure against such development risk, the worst-case circuit analysis(WCCA) is applied to predict perform preliminary performance analysis. WCCA calculates the maximum and minimum values by combining the parameter values of the relevant circuit after deriving the parameter values in consideration of the aging of the temperature and operating period at the component level. In this paper, the necessary matters for WCCA application are described. Chapter 2 describes the differences and characteristics of the WCCA techniques EVA, RSS, and Monte Carlo.Chapter 3 introduces the analysis process through the example circuit to introduce the actual analysis procedure. Chapter 4 describes the method of selecting an analysis technique for each condition of the analysis target. As a result of applying the procedures and analysis methods introduced in this paper when open, it was confirmed that preliminary performance analysis and part optimization design verification are possible.

• Structural Engineering and Mechanics
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• v.81 no.3
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• pp.293-303
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• 2022

As infrastructure ages and traffic load increases, serious public concerns have arisen for the well-being of bridges. The current health monitoring practice focuses on large-scale bridges rather than short span bridges. However, it is critical that more attention should be given to these behind-the-scene bridges. The relevant information about the construction methods and as-built properties are most likely missing. Additionally, since the condition of a bridge has unavoidably changed during service, due to weathering and deterioration, the material properties and boundary conditions would also have changed since its construction. Therefore, it is not appropriate to continue using the design values of the bridge parameters when undertaking any analysis to evaluate bridge performance. It is imperative to update the model, using finite element (FE) analysis to reflect the current structural condition. In this study, a FE model is established to simulate a concrete culvert bridge in New South Wales, Australia. That model, however, contains a number of parameter uncertainties that would compromise the accuracy of analytical results. The model is therefore updated with a neural network (NN) optimisation algorithm incorporating Monte Carlo (MC) simulation to minimise the uncertainties in parameters. The modal frequency and strain responses produced by the updated FE model are compared with the frequency and strain values on-site measured by sensors. The outcome indicates that the NN model updating incorporating MC simulation is a feasible and robust optimisation method for updating numerical models so as to minimise the difference between numerical models and their real-world counterparts.

• Journal of the Korean Geotechnical Society
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• v.37 no.7
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• pp.25-34
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• 2021

Since the dredging reclaimed land consisting of soft ground is very weak in support, the difficult and complex factors should be considered in the design to calculate accurate bearing capacity of soft ground. Recently, various reinforcement construction methods of soft ground have been designed for dredged landfills, but the stabilities are predicted by calculating conventional Meyerhof (1974) equation for trafficability in soft ground. Conventional equations increase economic costs by underestimating bearing capacity of weak ground in order to ensure constructive safety, so a modified equation has been proposed from the literature. The paper attempts to experiment and compute important factors, such as stitching fiber and seam tensile strength of geotextiles, that are not theoretically considered and can be identified in the field. In addition, The evaluation of the bearing capacity of the modified equation is verified to be stable for trafficability through the plate bearing test performed on site.

• Journal of the Korea Convergence Society
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• v.13 no.5
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• pp.267-278
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• 2022

This paper was intended to examine the function of emotion that affects the accuracy of statements in the context of eyewitness testimony. The main emotion theories and concepts introduced in previous studies examining the relation between testimony accuracy and negative emotions were examined based on the characteristics of the research method. The results were presented in the order of emotion definition, emotion inducing method, and emotion measurement method. Specifically, the definition of emotion was described based on studies on negative emotions, arousal, stress, and mood. The emotion inducing method was mainly described based on images, virtual reality, and staged events designed by researchers, which have been mainly used in laboratories. Emotion measurement methods were described with respect to the self-report, behavioral checklist, and psychophysiology. In addition, the emotional approach for objective and scientific repeated verification, the importance of effective experimental design and appropriate scientific memory test, and the need for individual difference control were discussed. This paper reinterprets the contradictions shown by previous research by systematically structuring the function of emotion that affects the accuracy of testimony. It was meaningful to provide a frame for comparative analysis of related studies. Ultimately, it is expected that such knowledge will be used as basic documents for judging the reliability of eyewitness testimony in a legal context.

• Journal of the Korean Geotechnical Society
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• v.38 no.11
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• pp.87-95
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• 2022

The geotechnical information constructed in the National Geotechnical Information DB System has been extensively used in design, construction, underground safety management, and disaster assessment. However, it is necessary to refine the geotechnical information because it has nearly 300,000 established cases containing a lot of missing or incorrect information. This research proposes a method for automatic quality control of geotechnical information using a fully connected neural network. Significantly, the anomalies in geotechnical information were detected using a database combining the standard penetration test results and strata information of Seoul. Consequently, the misclassification rate for the verification data is confirmed as 5.4%. Overall, the studied algorithm is expected to detect outliers of geotechnical information effectively.

• Journal of People, Plants, and Environment
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• v.23 no.1
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• pp.35-46
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• 2020

The purpose of this study was to investigate the effects of the horticultural therapy program on patients with mild cognitive impairment and mild dementia depending on the frequency and duration of the interventions. We developed the same 15-session program to improve cognitive functions and life satisfaction and alleviate depression of the elderly women with mild cognitive impairment or mild dementia. Subjects in Longer Treatment group participated in the program once a week for 15 weeks and subjects in Shorter Tratmet group participated twice a week for 7½ weeks. This study conducted pretest-posttest verification of both groups using quasi-experimental design involving 21 subjects. Elderly life satisfaction, Geriatric Depression Scale (short form), and the Korean Version of Consortium to Establish a Registry of Alzheimer's Disease (CERAD-K) were used in the evaluation. As a result, both groups showed an increase in life satisfaction, and a decrease in depression. However, there was a significant difference in the changes of the CERAD-K scores between the two groups (p < .05). In Longer Treatment group, life satisfaction increased significantly (p < .001), and depression decreased at a marginally significant level (p = .068), but no statistically significant change was observed in neurocognitive function. In Shorter Treatment group, life satisfaction increased at a marginally significant level (p = .059), and depression and CERAD-K scores decreased significantly (p < .05). However, in the case of Mini-Mental State Examination (MMSE-K), there was no significant change in both groups. According to these results, when planning a horticultural therapy program for persons with mild cognitive impairment or mild dementia, it is effective to organize and execute the program by determining the duration of intervention as 3 to 4 months or longer, even if this reduces the number of interventions per week.

• Journal of the Korean Society of Systems Engineering
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• v.17 no.2
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• pp.9-22
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• 2021

A study on the sustainability evaluation of the requirements of the mobile industry closely related to the human factor was needed. We conducted the sustainability evaluation of the mobile industry using a quantitative evaluation method with the AHP tool and a qualitative evaluation method reflecting the technological age flow of the philosophical thoughts to improve the reliability of the evaluation results of the model verification. And this evaluation is to evaluate the consistency of the connection between the national sustainability and the mobile industry. In order to draw the conclusion of the relevance, the team member Delphi 5-point scale was used. As a result, the priority was confirmed in the national sustainable development indicator and mobile industry indicator. Quantitative and qualitative evaluation was applied to the discontinued model of mobile to derive insufficient indicators, and it was confirmed that if the indicators were improved and reflected, it would be sustainable. And in order to secure reliability and accuracy, we made a proposal to apply the systems engineering process to the development of the model evaluation field. The systems engineering technology process meets the needs and requirements of stakeholders throughout the lifecycle and it is suitable for the development model of the industry's sustainability assessment.

• Journal of the Korea Society of Computer and Information
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• v.27 no.11
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• pp.13-18
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• 2022

In this paper, we proposed VW-FedAVG(Validation based Weighted FedAVG) which updates the global model by weighting according to performance verification from the models of each device participating in the training. The first method is designed to validate each local client model through validation dataset before updating the global model with a server side validation structure. The second is a client-side validation structure, which is designed in such a way that the validation data set is evenly distributed to each client and the global model is after validation. MNIST, CIFAR-10 is used, and the IID, Non-IID distribution for image classification obtained higher accuracy than previous studies.

• Journal of Practical Engineering Education
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• v.14 no.2
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• pp.413-423
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• 2022

The purpose of this study is to analyze the role of the job competency assessor who assess achievement of job performance ability based on NCS (educational training, qualifications, field experience, etc.) through competency assessment. For this purpose, job analysis including development and verification of the job model and selection of core task are conducted. As a result, main duties of the job competency assessor are to understand the NCS based assessment principle, establish an assessment plan, design and develop assessment tools, assess competence, provide feedback and re-assessment, record and manage assessment result, verify the internal assessment result, establish the RPL (recognition of prior learning) plan, implement the RPL and verify the RPL assessment result, and 48 task are derived. In addition, a total of 21 core tasks are derived based on the threshold value multiplied by the importance and difficulty of the task for each duty. Based on this, implications for job analysis of the job competency assessor are presented.