• KEPCO Journal on Electric Power and Energy
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• v.5 no.3
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• pp.135-140
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• 2019

Lattice towers and tubular steel poles have been commonly used for electrical power transmission in Korea. They are durable, structurally stable, simple and can easily be constructed in limited spaces. However, residents are opposed to construct transmission lattice towers in their areas because they are not visually attractive, and electrical field occur at the transmission lines. Underground transmissions have been used instead of the traditional towers to resolve these problems, however they are not cost effective to construct and run. Therefore, we have developed eco-friendly towers that are more attractive, well blending into the surrounding environment, and much more economical than underground transmissions. There are four categories of the eco-friendly electric transmission towers about design aspects. Firstly, there is decoration type such as tree tower and ensemble tower. Tree tower looks like actual trees with leaves and branches so it blends into surroundings. Ensemble towers were designed after pair of crane birds. Those towers have decoration features and art works. Structural examination and manufacturing this type would be very similar to the conventional transmission towers. Secondly, there is arm design type such as traditional tower. Design features are added to the existing towers. As partial design can be adoptable on these types, it can easily meet height regulations and attach to conventional lattice towers and tubular steel poles. Also, these towers are more economical than others. Third category is multipurpose type such as Sail Tower. These towers have simple pole or tubular structure with features which can be used as information message board, public relations and much more. This type will face greater wind pressure because of the area of the board, also visibility must take into consideration. Lastly, there is moulding type such as arc pylon. It is different shape to the conventional towers - lattice towers and tubular steel poles. Dramatic design changes have been adapted - from a hard and static tower to a soft and curved tower. These towers will well stand out in the field. However, structural examination and manufacturing this type would be difficult and costly. Also certain towers of this type would require scaffolding or false work to construct, which will result in limitations of the construction area. This paper shows KEPCO 154 kV Sail tower in detail. KEPCO 154 kV Sail tower that is included in fabrication of sample tower and tower testing has developed and the results are presented in this paper. We hope that sail tower is also considered as a solution to have public acceptance or to create a familiar atmosphere among towers and people in coastal area.

• Journal of Korean Neurosurgical Society
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• v.64 no.1
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• pp.125-135
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• 2021

Objective : This study aimed to validate the Korean version of the Repeatable Battery for the Assessment of Neuropsychological Status Update (K-RBANS). Methods : We performed a retrospective analysis of 283 psychiatric and neurosurgery patients. To investigate the convergent validity of the K-RBANS, correlation analyses were performed for other intelligence and neuropsychological test results. Confirmatory factor analysis was used to test a series of alternative plausible models of the K-RBANS. To analyze the various capabilities of the K-RBANS, we compared the area under the receiver operating characteristic (ROC) curves (AUC). Results : Significant correlations were observed, confirming the convergent validity of the K-RBANS among the Total Scale Index (TSI) and indices of the K-RBANS and indices of intelligence (r=0.47-0.81; p<0.001) and other neuropsychological tests at moderate and above significance (r=0.41-0.63; p<0.001). Additionally, the results testing the construct validity of the K-RBANS showed that the second-order factor structure model (model 2, similar to an original factor structure of RBANS), which includes a first-order factor comprising five index scores (immediate memory, visuospatial capacity, language, attention, delayed memory) and one higher-order factor (TSI), was statistically acceptable. The comparative fit index (CFI) (CFI, 0.949) values and the goodness of fit index (GFI) (GFI, 0.942) values higher than 0.90 indicated an excellent fit. The root mean squared error of approximation (RMSEA) (RMSEA, 0.082) was considered an acceptable fit. Additionally, the factor structure of model 2 was found to be better and more valid than the other model in χ2 values (Δχ2=7.69, p<0.05). In the ROC analysis, the AUCs of the TSI and five indices were 0.716-0.837, and the AUC of TSI (AUC, 0.837; 95% confidence interval, 0.760-0.896) was higher than the AUCs of the other indices. The sensitivity and specificity of TSI were 77.66% and 78.12%, respectively. Conclusion : The overall results of this study suggest that the K-RBANS may be used as a valid tool for the brief screening of neuropsychological patients in Korea.

• Journal of Korea Society of Waste Management
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• v.35 no.7
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• pp.616-626
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• 2018

The quality standards of solid refuse fuel (SRF) define the values for 12 physico-chemical properties, including moisture, lower heating value, and metal compounds, according to Article 20 of the Enforcement Rules of the Act on Resource Saving and Recycling Promotion. These parameters are evaluated via various SRF Quality Test Methods, but problems related to the heavy metal content have been observed in the microwave acid digestion method. Therefore, these methods and their applicability need improvement. In this study, the appropriate testing conditions were derived by varying the parameters of microwave acid digestion, such as microwave power and pre-treatment time. The pre-treatment of SRF as a function of the microwave power revealed an incomplete decomposition of the sample at 600 W, and the heavy metal content analysis was difficult to perform under 9 mL of nitric acid and 3 mL of hydrochloric acid. The experiments with the reference materials under nitric acid at 600 W lasted 30 minutes, and 1,000 W for 20 or 30 minutes were considered optimal conditions. The results confirmed that a mixture of SRF and an acid would take about 20 minutes to reach $180^{\circ}C$, requiring at least 30 minutes of pre-treatment. The accuracy was within 30% of the standard deviation, with a precision of 70 ~ 130% of the heavy metal recovery rate. By applying these conditions to SRF, the results for each condition were not significantly different and the heavy metal standards for As, Pb, Cd, and Cr were satisfied.

• Land and Housing Review
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• v.13 no.1
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• pp.23-38
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• 2022

As city tourism has recently been evaluated as a major indicator of urban competitiveness, strengthening the role of cities as tourist destinations has received more attention. However, industrialization and urbanization of many cities lead to population decline, extinction of traditional industries, and deterioration of living environments, weakening urban functions and competitiveness. Thus, it is essential for declining cities to build a measure to restore urban competitiveness by enhancing urban functions. Accordingly, this study focused on socio-cultural urban regeneration by exploring physical spaces for tourism destinations in declining cities. Different from general tourist destinations, tourism destinations of urban regeneration have a temporal perspective covering the past, present, and future. How does the temporal perspective of urban regeneration tourist destinations affect tourists' satisfaction and behavioral intention? In order to address these questions, this study conducts an empirical analysis based on structural equation modeling (SEM) using the sample of tourists who have visited urban regeneration tourism destinations. With SEM, this paper investigates structural relationships across variables by testing the hypothesis established in the proposed research model. The results show that precious memories of the past are the most important factor for tourists to visit urban regeneration tourist destinations. The empirical findings of this study will contribute to the research areas of urban tourism, urban regeneration tourism, and urban regeneration tourism destinations. In addition, this study can provide practical implications to develop socio-cultural contents of urban regeneration areas as tourism resources to establish plans for urban regeneration projects and achieve sustainable development strategies.

• Tunnel and Underground Space
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• v.31 no.6
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• pp.400-414
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• 2021

Under high-level radioactive waste repository conditions, bentonite as an engineered barrier material undergoes thermal, hydrological, mechanical, and chemical processes. We report the applications of X-ray Computed Tomography (CT) imaging technique on the characterization and analysis of bentonite over the past decade to provide a reference of the utilization of this technique and the recent research trends. This overview of the X-ray CT technique applications includes the characterization of the bentonite either in pellets or powder form. X-ray imaging has provided a means to extract grain information at the microscale and identify crack networks responsible for the pellets' heterogeneity. Regarding samples of pellets-powder mixtures under hydration, X-ray CT allowed the identification and monitoring of heterogeneous zones throughout the test. Some results showed how zones with pellets only swell faster compared to others composed of pellets and powder. Moreover, the behavior of fissures between grains and bentonite matrix was observed to change under drying and hydrating conditions, tending to close during the former and open during the latter. The development of specializing software has allowed obtaining strain fields from a sequence of images. In more recent works, X-ray CT technique has served to estimate the dry density, water content, and particle displacement at different testing times. Also, when temperature was added to the hydration process of a sample, CT technology offered a way to observe localized and global density changes over time.

• Korean Journal of School Psychology
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• v.17 no.3
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• pp.263-286
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• 2020

The purpose of this study was to explore how overly positive self-estimations in peer relationships relate to subjective well-being and to the occurrence of interpersonal behaviors supporting basic psychological needs among elementary school students. This study tested the optimal margin hypothesis of positive illusion by examining the curvilinear relationship between these variables. The sample consisted of 346 fifth and sixth grade students. The self-criterion residual method was used to derive self-estimation bias scores by regressing the real peer relations index (i.e., In-degree) on their perceived peer relationship qualities. The results showed that girls more strongly overestimated the quality of their peer relationships than boys. Self-estimation biases had a positive curvilinear relationship with negative affects and a negative curvilinear relationship with relatedness needs supporting interpersonal behaviors. These results supported the existence of the optimal margin of positive illusion because overestimations of the quality of peer relationships were associated with lower levels of negative affects and relatedness needs-supporting interpersonal behaviors, though these benefits flattened out and no further benefit was observed after an optimal level of overestimation. However, self-estimation bias was linearly associated with positive affect, autonomy needs-supporting interpersonal behaviors, and competence needs-supporting interpersonal behaviors. These results indicated that optimal margin hypothesis was not supported for all outcome variables.

• Journal of Korea Entertainment Industry Association
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• v.14 no.7
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• pp.95-106
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• 2020

The study was conducted to investigate the effectiveness of professional volleyball teams' integrated marketing communication(IMC) activities. The subjects of this study were a total of 400 surveys of visitors who visited the stadium to watch mans professional volleyball games from 2019 to 2020, and 385 questionnaires except for invalid or error questionnaires were used for research purposes. For factor analysis and reliability testing, IBM SPSS Statistics Ver 21.0 was used. Frequency analysis was conducted to examine the general characteristics. To verify differences between groups according to demographic and general characteristics, independent sample t-test and one-way ANOVA were performed, and correlation analysis was performed to examine the relationship between variables. In addition, regression analysis was conducted to verify the influence between variables. The results of the study are as follows. First, there was no difference in club image, club reputation, and club loyalty by gender. Second, there was no difference in club image, club reputation, and club loyalty according to age. Third, there was no difference in the club image, club reputation, or club loyalty according to the viewing experience. Fourth, professional volleyball team IMC activities were found to affect the club image. Fifth, professional volleyball team IMC activities were found to have an impact on the club's reputation. Sixth, it was shown that professional volleyball team IMC activities have an effect on club loyalty. Eighth, the club image was found to affect the club loyalty. Finally, it was found that the club reputation influenced the club loyalty.

• The Journal of the Korea Contents Association
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• v.21 no.11
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• pp.773-784
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• 2021

This study aimed to examine the mediation effects of foreign-born mothers' daily stress, depression, and neglectful parenting in the influence of mothers' acculturative stress on children's carrier barrier in multicultural families. For testing research questions, using Model 6 of the SPSS PROCESS Macro, this study analyzed simple and multiple mediation effects with a sample of 1,021 adolescents with Korean fathers and foreign-born mothers from the 8th wave's raw data of the Multicultural Adolescent Panel Study (MAPS). The main results are as follows. First, mothers' acculturative stress positively influenced children's carrier barrier. Second, mother's daily stress and neglectful parenting individually mediated the influence of mothers' acculturative stress on children's carrier barrier. Third, mother's depression and neglectful parenting dual-mediated the influence of mothers' acculturative stress on children's carrier barrier. Fourth, a triple mediation of mothers' daily stress, depression, and neglectful parenting was found in the influence of mothers' acculturative stress on children's carrier barrier. Based on the results, strategies to support the career development of multicultural adolescents were suggested.

• Science of Emotion and Sensibility
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• v.25 no.3
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• pp.77-90
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• 2022

This study seeks to develop a stretch sensor for measuring the wrist movements of people using fishing lures. In order to confirm wrist movement, a stretch sensor was attached to the wrist band, and measurements of the dorsiflexion, plantar flexion, and fishing landing motion were measured using a scale to gauge factor, tensile strength, and elongation recovery rate. A conductive sensor using CNT dispersion was developed and applied to the E-band under the same conditions. A total of 15 sensors of the same size and five types of impregnation once, twice, and three times each were used to measure the gauge factor using UTM. The sensor that was impregnated twice had the best gauge rate, and the prototypes were manufactured with three sensors with high gauge rates and tensile strength. The results of the operation test conducted by connecting to the Arduino showed that Sample 1, which had the highest tensile strength and gauge factor, had a stable graph wavelength in three operations. Samples 2 and 3 showed stable wavelengths in the dorsiflexion and the plantar flexion; however, signal noise appeared in the fishing landing motion. This showed stable wavelengths in the two motions, but the wavelengths of the graphs differ depending on the tensile strength and gauge factor in the fishing landing motion. As a result, it was possible to identify the conditions necessary for manufacturing a stretch sensor for measuring wrist movement. This study will contribute to the development of smart wearable products for lure fishing.

• Korean Journal of Environmental Agriculture
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• v.42 no.1
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• pp.71-81
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• 2023

An accurate and easy-to-use analytical method for determining isocycloseram and its metabolites (SYN549431 and SYN548569) residue is necessary in various food matrixes. Additionally, this method should satisfy domestic and international guidelines (Ministry of Food and Drug Safety and Codex Alimentarius Commission CAC/GL 40). Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) was used to determine the isocycloseram and its metabolites residue in foods. To determine the residue and its metabolites, a sample was extracted with 20 mL of 0.1% formic acid in acetonitrile, 4 g magnesium sulfate anhydrous and 1 g sodium chloride and centrifuged (4,700 G, 10 min, 4℃). To remove the interferences and moisture, d-SPE cartridge was performed before LC-MS/MS analysis with C₁₈ column. To verify the method, a total of five agricultural commodities (hulled rice, potato, soybean, mandarin, and red pepper) were used as a representative group. The matrix-matched calibration curves were confirmed with coefficients of determination (R²) ≥ 0.99 at a calibration range of 0.001-0.05 mg/kg. The limits of detection and quantification were 0.003 and 0.01 mg/kg, respectively. Mean average recoveries were 71.5-109.8% and precision was less than 10% for all five samples. In addition, inter-laboratory validation testing revealed that average recovery was 75.4-107.0% and the coefficient of variation (CV) was below 19.4%. The method is suitable for MFDS, CODEX, and EU guideline for residue analysis. Thus, this method can be useful for determining the residue in various food matrixes in routine analysis.