• Journal of The Geomorphological Association of Korea
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• v.28 no.3
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• pp.13-26
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• 2021

In mountain gully, channelized debris flow is an important phenomenon in the process of topographical change. Social infrastructure as roads may be damaged by channelized debris flows, but there has been little information about their occurrence and movement to prepare for the risk of the debris flow. Most of the channelized debris flows occur during heavy rains in mountainous valleys that are difficult to access, so there are not many field data. In this study, the topographical characteristics of the catchment, the rainfall and runoff related to the debris flow, the sedimentary pattern and the cross-sectional change of the channel bed, and the underflow velocity of the gravel bed have been investigated and analyzed in the Singi gully where the channelized debris flows occurred. In the catchment, there was almost no sediment runoff because the vegetation combine with the debris landforms and covered the surface. Therefore, the obvious cause of the channelized debris flows is the collapse of the slope and bed of the gully. Even if the gravel, cobbles, and boulders of the channel bed were lost by debris flow, the thalweg change due to debris flow may not be significant because they are supplied from the gully side slope normally. After the gabion structures were installed, the debris flow increased the thalweg change, bed erosion and side slope of the gully. Various sedimentary structures in the gully were classified according to the factors supporting the sedimentation. The hypsometric curve of the gully reflects the debris landforms and vegetation characteristics of the watershed and the sediment runoff due to debris flow, etc. The relationship between the flow velocity and the hydraulic gradient was non-linear under the condition that the porous medium with gully bed gravels is saturated with water. These results may be used as basic data for channelized debris flow research.

• Asia Marketing Journal
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• v.15 no.2
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• pp.49-73
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• 2013

In this study, the author develops and tests a model that incorporates the mediating effects of two frontline employee psychological variables (emotional exhaustion and intrinsic motivation) based on job demand and resource model. As a form of environmental resource, person-organization fit was proposed as a leading factor of frontline employee boundary spanning behavior through emotional exhaustion and intrinsic motivation. All measures were adapted from or developed based on prior research. Data for the study were collected from a cross-sectional sample of retail bank employees in South Korea. Questionnaires were distributed to 500 frontline employees across several banks. Of these, 322 usable questionnaires were returned. To analyze the data, a structural equation model procedure using LISREL 8.5 was employed. Results show that an employee's perceived fit with his/her organization enhances intrinsic motivation and reduces emotional exhaustion. These mechanisms, in turn, increase the employee's boundary spanning behavior. These results support the notion that person-organization fit should be one of the factors affecting motivation, affect and attachment, and extends such an understanding to a purely service-based environment among customer contact employees. Results also confirms that P-O fit can be viewed as environmental resources, and the JD-R model provides a theoretical base in further studying the antecedent role of P-O fit on frontline employees's boundary spanning behavior through intrinsic motivation and emotional exhaustion. These results suggest that organizations have to do their best to manage P-O fit, be it through employee screening or training and workshops to try and align organization and employee values and objectives. If managers of organizations are positively evaluated by the employees, it will be easier for them to, give things of value to employees, such as sense of direction, values, and recognition, and receive other things in return such as esteem and responsiveness. Consequently, organizational leaders are not only able to manage employee experiences, but also their fit with the organization. Even if a manager cannot control employee P-O fit, this research suggests, that a focus on reducing emotional exhaustion rather than increasing intrinsic motivation seems optimal. This research also supports the idea that motivation has a direct association with a frontline employee's boundary spanning behavior. Even in situations where emotional exhaustion cannot be reduced, organizations may still influence frontline behaviors through motivation.

• Korean Journal of Culture and Social Issue
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• v.22 no.1
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• pp.65-85
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• 2016

In this study, we examined the longitudinal change of multicultural acceptability, peer relationship, and teacher relationship using latent growth curve modeling. This study used data from the second, third, and fourth waves of the middle school student cohort (N=2,178) of the Korean Children-Youth Panel Survey (KCYPS). The dependent variable was multicultural acceptability. The independent variables were peer relationship and teacher relationship. The major longitudinal findings of this study are as follows: First, peer relationships, teacher relationships and multicultural acceptability increased with time. Second, peer relationship showed a significant effect on the multicultural acceptability over time. Finally, the teacher relationship showed a significant effect on the multicultural acceptability over time. These results show differentiation with previous cross-sectional studies of multicultural acceptability. Furthermore, it is expected that this study will provide educational implications for the cultivation of multicultural acceptability.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.3
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• pp.184-191
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• 2023

With increasing corrosion in RC (Reinforced Concrete) structures, cracks occurred due to corrosion products and bearing load resistance decreased. In this study, corrosion was induced through an accelerated corrosion test (ICM: Impressed Current Method) with 140 hours of duration, and changes in USV (Ultra-Sonic Velocity), flexural failure load, and corrosion weight were evaluated before and after corrosion test. Three levels of cover depth (20 mm, 30 mm, and 40 mm) were considered, and the initial cracking period increased and the rust around steel decreased with increasing cover depth. In addition, the USV linearly decreased with decreasing cover depth and increasing amount of corrosion. In the flexural loading test, the bending capacity decreased by more than 10% due to corrosion, but a clear correlation could not be obtained since the corrosion ratio was small, so that the effect of slip was greater than that of reduced cross-sectional area of steel due to corrosion. As cover depth increased, the produced corrosion amount and USV changed with a clear linear relationship, and the cracking period due to corrosion could be estimated by the gradient of the measured corrosion current.

• Journal of Korean Society of Disaster and Security
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• v.16 no.2
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• pp.57-63
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• 2023

Recently, Heavy rains and super typhoons occurred by climate change cause a lot of damage in Korea. In order to reduce such damage, various types of river maintenance projects are being promoted, but it is difficult to maintain the balance of rivers in Korea with distinct flood and dry seasons. In particular, river structures installed as a river maintenance project cause various problems such as scouring of structures and their foundations during floods and river bed changes. In order to reduce such bed scour, various vanes are installed in the bend of the river, and various bed scour reduction effects appear depending on the size, arrangement, and shape of the vanes. The vane regenerates the secondary flow in the opposite direction to the secondary flow generated by the centrifugal force, thereby reducing scour around the outer bed and promoting deposition. The theory of this study uses the governing equation applying the continuity equation that satisfies the law of conservation of mass and the momentum equation that satisfies the conservation of momentum, and measures the overall average flow velocity change rate according to design factors to investigate the effect of vanes under various conditions. Both the average and cross-sectional flow velocities decreased in both the trapezoidal vane and the square vane. In addition, vanes installed perpendicularly or inclined to the direction of river flow generate a secondary flow in the opposite direction to the secondary flow generated by centrifugal force, thereby canceling the secondary flow of centrifugal force, so the effect of the vane appears.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.6
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• pp.735-747
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• 2023

In recent times, the sharp increase in extreme flood damages due to climate change has posed a challenge to effectively address flood-related issues solely relying on conventional flood management infrastructure. In response to this problem, this study aims to consider the effectiveness of nature-based flood management approaches, specifically levee retreat and relocation. To achieve this, we utilized a 1D numerical model, HEC-RAS, to analyze the flood reduction effects concerning floodwater levels, flow velocities, and time-dependent responses to a 100-year frequency flood event. The analysis results revealed that the effect of creating a flood buffer zone of the nature-based solution extends from upstream to downstream, reducing flood water levels by up to 30 cm. The selection of the flow roughness coefficient in consideration of the nature-based flood buffer space creation characteristics should be based on precise criteria and scientific evidence because it is sensitive to the flood control effect analysis results. Notably, floodwater levels increased in some expanded floodplain sections, and the reduction in flow velocities varied depending on the ratio of the expanded cross-sectional area. In conclusion, levee retreat and floodplain expansion are viable nature-based alternatives for effective flood management. However, a comprehensive design approach is essential considering flood control effects, flow velocity reduction, and the timing of peak water levels. This study offers insights into addressing the challenges of climate-induced extreme flooding and advancing flood management strategies.

• Journal of Preventive Medicine and Public Health
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• v.56 no.5
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• pp.467-474
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• 2023

Objectives: Diabetes mellitus (DM) is a serious public health issue that places a heavy financial, social, and health-related burden on individuals, families, and healthcare systems. Self-reported health-related quality of life (HRQoL) is extensively used for monitoring the general population's health conditions and measuring the effectiveness of interventions. Therefore, this study investigated HRQoL and associated factors among patients with type 2 DM at a primary healthcare center in Indonesia. Methods: A cross-sectional study was conducted in Klaten District, Central Java, Indonesia, from May 2019 to July 2019. In total, 260 patients with DM registered with National Health Insurance were interviewed. HRQoL was measured with the EuroQol Group's validated Bahasa Indonesia version of the EuroQoL 5-Dimension 5-Level (EQ-5D-5L) with the Indonesian value set. Multivariate regression models were used to identify factors influencing HRQoL. Results: Data from 24 patients were excluded due to incomplete information. Most participants were men (60.6%), were aged above 50 years (91.5%), had less than a senior high school education (75.0%), and were unemployed (85.6%). The most frequent health problems were reported for the pain/discomfort dimension (64.0%) followed by anxiety (28.4%), mobility (17.8%), usual activities (10.6%), and self-care (6.8%). The average EuroQoL 5-Dimension (EQ-5D) index score was 0.86 (95% confidence interval [CI], 0.83 to 0.88). In the multivariate ordinal regression model, a higher education level (coefficient, 0.08; 95% CI, 0.02 to 0.14) was a significant predictor of the EQ-5D-5L utility score. Conclusions: Patients with diabetes had poorer EQ-5D-5L utility values than the general population. DM patients experienced pain/discomfort and anxiety. There was a substantial positive relationship between education level and HRQoL.

• Journal of Korean Medicine Rehabilitation
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• v.33 no.4
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• pp.15-29
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• 2023

Objectives The purpose of this study is to systematically review the effects of Neuromuscular Electrical Stimulation treatment on muscle wasting in cancer patients. Methods Randomized controlled trials (RCTs) were searched from seven online databases (PubMed, Cochrane Library, EMBASE, China National Knowledge Infrastructure, Oriental Medicine Advanced Searching Integrated System, Korean studies Information Service System, Research Information Sharing Service. The selected RCTs were evaluated for methodological quality through the Cochrane RoB. Results A total of 126 articles were identified, and 4 randomized controlled trials were selected for systematic review. In one study, it was found that there were statistically significant improvements in the Health-Related Quality of Life (FACTH&N total score, p<0.001). Additionally, significant effects were observed in measurements that represented the size of the quadriceps muscle (cross-sectional area of Vastus lateralis and Rectus femoris, p=0.004), maximum muscle strength, the twitch response of resistance muscles, and voluntary activation (p<0.001). However, no significant differences were observed between the intervention and control groups in terms of quadriceps muscle strength in two other studies (p>0.05). Lastly, while one study showed no significant differences in muscle fiber characteristics between the two groups, it did report significant improvements in measurements related to mitochondria within muscle tissue and muscle strength in the intervention group (p<0.05). Conclusions Neuromuscular electrical stimulation can be a method used to improve muscle strength in muscle wasting of cancer patients, but it is difficult to see its effects as significant compared to other treatments.

• Composites Research
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• v.36 no.6
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• pp.435-440
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• 2023

This study aimed to enhance the thermal conductivity of B₄C/Al composite materials, commonly used in transport/storage containers for spent nuclear fuel, by incorporating both boron carbide (B₄C) and cubic boron nitride(cBN) as reinforcing agents in an aluminum (Al) matrix. The composite materials were successfully manufactured through a stir casting process and practical neutron-absorbing materials were obtained by rolling the fabricated composite ingot. The evaluation of the thermal conductivity of the fabricated composites was carried out because thermal conductivity is critical for neutron absorbing materials. The thermal conductivity measurement results indicated an approximately 3% increase in thermal conductivity under the same volume fraction when compared to composite materials using only B₄C particles. Through neutron absorption cross-sectional area calculations, it was confirmed that the neutron absorption capability decreased to a negligible level. Based on the findings of this study, new design approaches for neutron absorption materials are proposed, contributing to the development of high-performance transport/storage containers.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.5
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• pp.251-264
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• 2022

Previous researches related to emotional labor have been cross-sectional studies focusing on static differences in emotional exhaustion. Previous studies on these relationships have not highlighted the dynamic properties of these relationships. This purpose of this study is to investigate the effect of emotional labor strategy on perceived emotional exhaustion and depression. This study was conducted by paying attention to the fact that service industry workers who have to respond kindly to customers often have to show emotions which is necessary for their business to the outside world rather than showing their true emotions. The results of this study are summarized as follows. First, it was confirmed that surface acting had a positive influence on emotional exhaustion, but deep acting had a negative influence to emotional exhaustion. Second, it was found that surface acting had a positive influence on depression, but deep acting had a negative influence on depression. Third, it was confirmed that the effect of deep acting on emotional exhaustion decreased when emotional labor was performed through deep acting on Mondays, Tuesdays, and Wednesdays, while emotional exhaustion was not significant on Thursdays and Fridays. Fourth, it was confirmed that the difference in the effect of emotional labor strategy on depression was greater in the case of performing emotional labor through surface acting than in the case of performing emotional labor through deep acting.