• Steel and Composite Structures
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• v.46 no.3
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• pp.385-401
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• 2023

Steel is becoming increasingly popular due to its high strength, excellent ductility, great assembly performance, and recyclability. In reality, steel structures serving for a long time in atmospheric, industrial, and marine environments inevitably suffer from corrosion, which significantly decreases the durability and the service life with the exposure time. For the mechanical properties of corroded steel, experimental studies are mainly conducted. The existing numerical analyses only evaluate the mechanical properties based on corroded morphology at the isolated time-in-point, ignoring that this morphology varies continuously with corrosion time. To solve this problem, the relationships between pit depth expectation, standard deviation, and corrosion time are initially constructed based on a large amount of wet-dry cyclic accelerated test data. Successively, based on that, an in-situ pitting evolution method for evaluating the residual tensile strength of corroded steel is proposed. To verify the method, 20 repeated simulations of mass loss rates and mechanical properties are adopted against the test results. Then, numerical analyses are conducted on 135 models of corrosion pits with different aspect ratios and uneven corrosion degree on two corroded surfaces. Results show that the power function with exponents of 1.483 and 1.091 can well describe the increase in pit depth expectation and standard deviation with corrosion time, respectively. The effect of the commonly used pit aspect ratios of 0.10-0.25 on yield strength and ultimate strength is negligible. Besides, pit number ratio α equating to 0.6 is the critical value for the strength degradation. When α is less than 0.6, the pit number increases with α, accelerating the degradation of strength. Otherwise, the strength degradation is weakened. In addition, a power function model is adopted to characterize the degradation of yield strength and ultimate strength with corrosion time, which is revised by initial steel plate thickness.

• Biomedical Science Letters
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• v.26 no.3
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• pp.210-216
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• 2020

The purpose of this study was to evaluate GDH & Toxin (GDT) tests for the identification of the presence of Clostridioides difficile (C. difficile) as well as to detect whether any toxin was present in the feces of patients suspected of diarrhea associated with C. difficile. Data related to the results of toxin and culture (TC) tests and GDT tests conducted on patients with diarrhea and suspected CDI between January 2017 and august 2018, positive test rates, patient ages and sexes, whether the patients were hospitalized, and turnaround time (TAT) were analyzed retrospectively. Of the 7,554 total tests conducted for CDI diagnosis, 1,010 TC tests (14.9%) were positive, while 92 GDT tests (12.0%) were positive. Of these positive cases, 815 (80.7%) identified through TC test and 80 (87%) identified through GDT test were inpatients. also, among the patients with positive test results, 497 (49.2%) diagnosed through TC test and 45 (48.9%) diagnosed through GDT test were aged 61 years or older. The total time required to complete a TC test was 83.6 hours, while the time required for a GDT test was 11.2 hours, equating to an approximately three-day difference between the two tests. The detection of toxin-producing C. difficile is important in CDI diagnosis, but the commonly used Enzymeimmunoassay (EIA) toxin tests with low sensitivity result in delayed CDI diagnosis time. Therefore, primary screening tests for CDI diagnosis using the GDT method and secondary tests using additional methods are considered most effective.

• Journal of the Korean Society of Clothing and Textiles
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• v.19 no.3
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• pp.471-482
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• 1995

Using the acetate velvet and viscose velvet whose pile lengths were sheared as 1.45, 1.55, 1 65, 1.75, 1.85, 1.90mm under the condition equating the weaving process of ground fabric, the conclusions were as follows through the results of the sensory assessments estimated by women students in our university and the physical properties, H. V and T. H. V obtained by KES-F system. 1. In the sensory assessments estimated by the method of paired comparison and ranking of samples, the longer pile length was, the more the hand values of smoothness, softness, thickness, heaviness increased on the whole. 2. The H V. and T. H. V. measured by KES-F system were as follows; Kohi increased to pile length 1.85mm and then decreased a little at 1.90mm. hummer increased as pile length was longer. Fukurami increased to pile length 1.75mm and then decreased gradually as pile length was longer. Total hand value increased gradually from 1. 45mm to 1.85mm, had the top value at 1.85mm, and then decreased a little at 1.90mm. 3. In the results of summarizing $\ulcorner$the physical properties correlated closely with the H. V obtained by sensory assessments$\lrcorner$ and tithe Physical properties correlated closely with the H. V. and T. H. V obtained by KES-F systems, it showed that all the sensory properties correlated closely with compressive energy, flexural rigidity, thickness, weight and pile ratio in the former and that the physical properties correlated closely with each H V and T. H. V were different in the latter. 4. It showed that factor 1 was related to compressive energy, thickness, weight, pile ratio, factor 2 was related to recovery energy, compressive resilience, compressive index, and factor 3 was related to compressive recovery ratio in the result of factor analysis. 5. In the multiple repression analysis, the expressions of all sensory properties had compressive ratio, frictional coefficient in the regression expressions of $\ulcorner$H. V. obtained by sensory assessments$\lrcorner$, while the expressions of each H. V. and different physical properties in the regression expressions of $\ulcorner$H. V. obtained by KES-F system$\lrcorner$.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.1
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• pp.15-29
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• 2009

Most breakwater armor blocks are designed by using Hudson's or van der Meer's formula. The minimum weight of armor blocks is calculated by equating the resistance to the load in each formula. The larger value is then chosen as the design weight. In this study, we have performed reliability analyses for thus designed breakwater armor blocks of 12 trade harbors and 8 coastal harbors in Korea. The probability of failure calculated by the reliability analysis provides a criterion for evaluating the stability of armor blocks. The calculated probability of failure was almost same for all the breakwaters so that we were able to quantitatively evaluate the safety level of armor blocks of existing breakwaters. We also found that the safety factor used in the deterministic design method and the probability of failure in the reliability design method show a linear relationship. Therefore the probability of failure of existing breakwaters can be quantitatively calculated from the safety factors. The calculated probability of failure could also be used for determining the target probability of failure in the future.

• 재활복지
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• v.20 no.3
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• pp.105-124
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• 2016

The This study aims to verify the causal relationship among physically disability persons participation in exercise, heart rate variance, and facial expression recognition. To achieve such research goal, this study targeted 139 physically disability persons and as for sampling, purposive sampling method was applied. After visiting a sporting stadium and club facilities that sporting events were held and explaining the purpose of the research in detail, only with those who agreed to participate in the research, their heart rate variance and facial emotion awareness were measured. With the results of measurement, mean value, standard deviation, correlation analysis, and structural equating model were analyzed, and the results are as follows. The quantity of exercise positively affected sympathetic activity and parasympathetic activity of autonomic nervous system. Exercise history of physically disability persons was found to have a positive influence on LF/HF, and it had a negative influence on parasympathetic activity. Sympathetic activity of physically disability persons turned out to have a positive effect on the recognition of the emotion, happiness, while the quantity of exercise had a negative influence on the recognition of the emotion, sadness. These findings were discussed and how those mechanisms that are relevant to the autonomic nervous system, facial expression recognition of physical disability persons.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.794-801
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• 2023

The high seas, covering the majority of the world's oceans, hold invaluable marine resources crucial for the growth of the marine bio-industry. The High seas bioresources program of South Korea is at the forefront of these global efforts. This study aims to gauge public awareness and quantify the project benefits, offering insights for future policy decisions. The results revealed that the estimated annual average willingness to pay (WTP) was 3,778.8 KRW, equating to approximately 81.54 billion KRW when extrapolated to the entire national population. The implications of the study are twofold: The project benefits, based on WTP, are substantial, amounting to approximately 81.5 billion KRW annually. This provides critical reference material for future policy formulation, given the considerable WTP in comparison to the current investment. Although interest in international sea marine biological resources is growing, public awareness remains relatively low. However, the project plays a crucial role in building essential databases for the marine bio-industry and securing international sea marine biological resources. Public interest and sustained support are pivotal, not only for this project but also for future policy implementation. Strategies to enhance public awareness are essential, and the study results offer valuable input for future policy decisions.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.1
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• pp.1-16
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• 2024

Alvin Toffler mentioned that it is important for future society to keep pace with synchronization and that time deviations can hinder social development. As we experience the new normal era of untact, we have experienced an increase in non-face-to-face contact and accelerated digital transformation. Amid these rapid changes, we can maintain the need for synchronization or change in space. Therefore, we would like to study what kind of settlements people create and choose. We looked at the metaverse as an object that could indirectly find out about this, and used the content called "Animal Crossing" to collect data related to the spatial form of the metaverse. Sampling utilized a judgment sampling method during non-probability sampling to alleviate differences due to the progress of the game. The collected data was classified according to floor plan and location type and briefly organized through descriptive statistics. After matching each facility by use, data was constructed by setting coordinates for each cluster and listing them. This data was interpreted graphically on the coordinate plane for each cluster, and Euclidean analysis was performed to analyze the relationships between clusters and residential choice using a Euclidean matrix. As a result of the analysis, it could be interpreted that efficiency was pursued by arranging similar functions in close proximity. Nevertheless, when choosing a residence, it was interpreted that the intention was to create a community through arrangement adjacent to residents rather than efficiency or convenience. Due to the differences between the metaverse and the real world, it is expected that there will be limitations in equating it with reality. However, through the space expressed in the virtual world by people who are far away from the constraints of reality, we can indirectly know the wishes that we have not been able to express due to our lack of awareness.

• 한국노년학
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• v.37 no.1
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• pp.173-200
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• 2017

This study is designed to verify the actual effect on the prevention of the elderly suicide of the integrated crisis intervention service which has been widely provided across all local communities in Gyeonggi-province focusing on the integrated crisis intervention model developed for the prevention of elderly suicide. The integrated crisis intervention model for the local communities and its manual were developed for the prevention of elderly suicide by integrating the crisis intervention theory which contains local community's integrated system approach and the stress vulnerability theory. For the analysis of the effect, the geriatric depression and suicidal ideation scale was adopted and the data was collected as follows; The data was collected from 258 people in the first preliminary test. Then, it was collected from the secondary test of 184 people after the integrated crisis intervention service was performed for 6 months. The third collection of data was made from 124 people after 2 or 3 years later using the backward tracing method. As for the analysis, the researcher used the R Statistics computing to conduct the test equating, and the vertical scaling between measuring points. Then, the researcher conducted descriptive statistics analysis and univariate analysis of variance, and performed multi-level modeling analysis using Bayesian estimation. As a result of the study, it was found out that the integrated crisis intervention model which has been developed for the elderly suicide prevention has a statistically significant effect on the reduction of elderly suicide in terms of elderly depression and suicide ideation in the follow-up measurement after the implementation of crisis intervention rather than in the first preliminary scores. The integrated crisis intervention model for the prevention of elderly suicide was found to be effective to the extent of 0.56 for the reduction of depression and 0.39 for the reduction of suicidal ideation. However, it was found out in the backward tracing test conducted 2-3 years after the first crisis intervention that the improved values returned to its original state, thus showing that the effect of the intervention is not maintained for long. Multilevel analysis was conducted to find out the factors such as the service type(professional counseling, medication, peer counseling), characteristics of the client (sex, age), the characteristics of the counselor(age, career, major) and the interaction between the characteristics of the counselor and intervention which affect depression and suicidal ideation. It was found that only medication can significantly reduce suicidal ideation and that if the counselor's major is counseling, it significantly further reduces suicidal ideation by interacting with professional counseling. Furthermore, as the characteristics of the suicide prevention experts are found to regulate the intervention effect on elderly suicide prevention in applying integrated crisis intervention model, the primary consideration should be given to the counseling ability of these experts.