• Journal of Korean Society of Disaster and Security
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• v.14 no.4
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• pp.47-60
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• 2021

Recently, as the occurrence frequency of sudden floods due to climate variability increased, the damage of aging chuteway slabs of spillway are on the rise. Accordingly, a wide array of field survey, hydraulic experiment and numerical simulation have been conducted to find the cause of damage on chuteway slabs. However, these studies generally reviewed the flow characteristics and distribution of pressure on chuteway slabs. Therefore the derivation of damage on chuteway slabs was relatively insufficient in the literature. In this study, the cavitation erosion and hydraulic jacking were assumed to be the causes of damage on chuteway slabs, and the phenomena were reproduced using 3D numerical models, FLOW-3D and COMSOL Multiphysics. In addition, the cavitation index was calculated and the von Mises stress by uplift pressure distribution was compared with tensile and bending strength of concrete to evaluate the possibility of cavitation erosion and hydraulic jacking. As a result of numerical simulation on cavitation erosion and hydraulic jacking under various flow conditions with complete opening gate, the cavitation index in the downstream of spillway was less than 0.3, and the von Mises stress on concrete was 4.6 to 5.0 MPa. When von Mises stress was compared with tensile and bending strength of concrete, the fatigue failure caused by continuous pressure fluctuation occurred on chuteway slabs. Therefore, the cavitation erosion and hydraulic jacking caused by high speed flow were one of the main causes of damage to the chuteway slabs in spillway. However, this study has limitations in that the various shape conditions of damage(cavity and crack) and flow conditions were not considered and Fluid-Structure Interaction (FSI) was not simulated. If these limitations are supplemented and reviewed, it is expected to derive more efficient utilization of the maintenance plan on spillway in the future.

• Journal of the Korean Society of Earth Science Education
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• v.15 no.3
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• pp.354-372
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• 2022

The purpose of this study is to explore the philosophical position of various scientific theories based on the scientific worldviews for science education. In addition, it aims to expand science education, which has usually dealt with epistemology and methodology, to ontology, that is, to the problem of metaphysics. It can be said that there exists a physical realism, traditionally defined as a strong determinism of the metaphysical belief. That is fixed and unchanging objective scientific knowledge independent of our minds, which was established by Newton, Einstein and Schridinger. What can be seen in the natural laws of dynamics can be called 'mathematicization'. Einstein also shook the traditional views to some extent through the theory of relativity, but his theory was still close to traditional thinking. On the contrary, to escape from this rigid determinism, we need anthropomorphic concepts such as 'possibility' and 'chance'. It is a characteristic of the modern scientific worldviews that leads the change of scientific theory from a classically strong deterministic thought to a weak deterministic accidental accident, probability theory, and a naturalistic point of view. This can be said to correspond to Darwin's theory of evolution and quantum mechanics. We can have three types of epistemological worlds that justify this ontological worldviews. These are rationalism, empiricism and naturalism. In many cases, science education does not tell us what kind of metaphysical beliefs the scientific theories we deal with in the field of education are based on. Also, science education focuses only on the understanding of scientific knowledge. However, it can be said that true knowledge can bring understanding only when it is connected to the knowledge of learned knowledge and the learner's own metaphysical belief in the world. Therefore, in the future, science education needs to connect various scientific theories based on scientific worldviews and philosophical position and present them to students.

• Korean Journal of Psychosomatic Medicine
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• v.30 no.2
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• pp.196-202
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• 2022

Objectives : The purpose of this study was to quantitatively assess the degree of Graves' Disease affecting mental health through the results of multiphasic military personality inventory (MPI) in 19-year-old men. Methods : We collected and analyzed the results of the MPI for 592 healthy subjects and 148 Graves' disease patients among the 19-year-old men who visited the Military Manpower Administration from February 2008 to January 2010. Results : Among demographic characteristics, both Graves' disease and control group are 19-year-old men. Educational level, socioeconomic status, parental relationship, and BMI were not statistically different between the two groups (χ²=0.089, p=0.766; χ²=5.090, p=0.278; χ²=5.988, p=0.112 ; t=-0.635, p=0.526). In the MPI, among validity scales, the score of the faking-good subscale was significantly lower in the Graves' group (t=3.507, p<0.001), but in the faking-bad and infrequency subscales scores were not significantly different between two groups (t=-1.700, p=0.090; t=-0.519, p=0.604). Among the neurosis scale, anxiety, depression, somatization, and personality disorder subscale scores were all significantly higher in Graves' disease group (t=-3.323, p<0.001; t=-4.210, p<0.001; t=-6.202, p<0.001; t=-2.872, p<0.01). Among the psychopath scale, each score of schizophrenia and paranoia subscales were not statistically different between the two groups (t=-0.158, p=0.874; t=-0.846, p=0.398). Conclusions : According to MPI result, we can confirm that Graves' disease patients in 19-year-old-men may appear features such as anxiety, depression, somatization and personality tendency (introversion or impulsivity) than the control group.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.40 no.4
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• pp.32-48
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• 2022

This study analyzed the construction pattern and historical reality of Gwallamji Pond(觀纜池) in the rear garden of Changdeokgung Palace(昌德宮), which has been received as distorted information and has not received sufficient attention. The main topics consisted of the construction period and reorganization in the pond garden, changes in the installed wooden bridge, the existence of the berthing facility, and whether the plan shape was deformed. The main results of this study can be summarized as follows. First, the Gwallamji Pond was already completed before the Gapsin Coup, which occurred in the year of King Gojong. Since then, the Gwallamji Pond area, including the surrounding facilities, has been neglected for a while and was extensively renovated in the early 1900s. It is difficult to find a clear basis for the suspension and resumption of the Gwallamji Pond construction proposed in the previous discussion. Second, three types of wooden bridges with different shapes and structures were installed sequentially in the Gwallamji Pond. In particular, the second wooden bridge, which installed after the maintenance of the Gwallamji Pond, is judged to be the pontoon bridge depicted in Donggweoldohyeong(東闕圖形), and the railing of the bridge was decorated to symbolize the imperial family of the Korean Empire. The third wooden bridge, which appeared intensively in Japanese colonial era, was a Japanese-style bridge. Third, a berth facility for boarding and disembarking existed on the eastern shore of the Gwallamji Pond. The berth facility is also described in Donggweoldohyeong and it remained until the Japanese colonial period. However, as the maintenance work of the Gwallamji Pond was carried out several times after liberation, the berth facility was gradually damaged, and there are no traces left now. Fourth, The Gwallamji Pond was originally constructed in a planar shape of the Korean Peninsula similar to the present. It is necessary to reconsider the conventional theory that the Gwallamji Pond, made in the shape of a gored-shaped bottle, was renovated in the shape of the Korean Peninsula in Japanese colonial era. Even when the term Pandoji Pond(半島池) first appeared, there was no view that the Japanese intentionally modified the Gwallamji Pond.

• Journal of Korean Society of Forest Science
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• v.111 no.4
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• pp.567-582
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• 2022

Chainsaw use for motor-manual timber harvesting in South Korea is associated with worker safety issues. However, forestry operations such as timber harvesting have already been mechanized to reduce hazards to workers and increase productivity. This study analyzed the productivities and costs of felling and processing, felling and processing using an excavator-based stroke harvester for Pinus rigida and Quercus mongolica stands. To efficiently operate the stroke harvester, we developed a regression equation to estimate the productivities of felling and processing, felling, and processing operations,and we conducted sensitivity analysis of the operation costs using DBH and machine utilization. The felling and processing productivity was 6.53 and 4.02 m³/SMH for P. rigida a nd Q. mongolica, respectively, and the cost was 17,983 and 29,210 won/m³, respectively. The felling productivity for P. rigida a nd Q. mongolica wa s 40.9 and 23.0 m³/SMH, respectively, and the cost was 2,667 and 4,743 won/m³, respectively. The processing productivity for P. rigida and Q. mongolica was 8.25 and 7.75 m³/SMH, respectively, and the cost was 15,296 and 16,283 won/m³, respectively. In the developed regression equation, the DBH, traveling distance, and number of cuttings were found to be important factors (p<0.05). Therefore, it is necessary to construct a DB considering the various conditions and species associated with harvester operations, and further research is needed to increase the accuracy of predicting operation productivity and costs.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.4
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• pp.414-427
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• 2022

This study aims to analyze the color distribution of maxillary permanent incisors in Korean pediatric patients and determine the effects of age and root developmental stage on tooth color. The L^*a^*b^* values of 404 sound and fully erupted maxillary incisors without dental caries, restorations, trauma history or discoloration from 101 Korean patients between ages 7 and 15, with a mean age 10.0 ± 1.5, were analyzed with a spectrophotometer. CIE L^*a^*b^* values were 84.01, 0.17, and 24.07 in maxillary central incisors, and 82.33, 0.31, and 25.99 in maxillary lateral incisors. L^* values of maxillary central incisors were higher, and b^* values of maxillary central incisors were lower than those of maxillary lateral incisors (p < 0.001). The color differences among the subregions exceeded the clinical perceptibility threshold in both of the maxillary central and lateral incisors. L^* value for children at age 10 and younger was 84.13 in maxillary central incisors and 84.04 in maxillary lateral incisors, and those of older patients were 80.62 and 80.56, respectively. L^* value of maxillary incisors of children at age 10 and younger was significantly higher than that of older patients. The root developmental stage did not affect tooth color. This study suggests that the color differences between maxillary central and lateral incisors and among the subregions of a tooth and the effects of age should be considered for aesthetic restorations of permanent incisors in pediatric patients.

• Journal of Life Science
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• v.32 no.6
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• pp.430-437
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• 2022

We conducted a study on the whitening activity of Abies nephrolepis MAX. extracts. The electron-donating ability of 70% ethanol extracts from A. nephrolepis MAX. Stem (AN-S) and A. nephrolepis MAX. Leaf (AN-L) were found to be 89.4% and 90.9% at 1,000 ㎍/ml concentration, respectively. Their ABTS⁺ radical scavenging abilities were found to be 88.8% and 96% 500 ㎍/ml concentration, respectively. Their tyrosinase inhibitory effects were found to be 48.5% and 31.1% at 500 ㎍/ml concentration, respectively. Cell survival rates measured in B16F10 were examined with the AN-S and AN-L extracts. Results showed cell viabilities of 98.3% and 94.4% at 500 ㎍/ml concentration, respectively. The protein and mRNA expression inhibitory effects of AN-S and AN-L extracts were measured by Western blotting and RT-PCR, respectively, at 25, 50 and 100 ㎍/ml concentrations. The results of western blotting showed that the AN-S extract at 100 ㎍/ml concentration decreased the TRP-1 protein expression rate by 46%. The results of Western blotting also showed that the AN-L extract at 100 ㎍/ml concentration decreased the MITF protein expression rate was by 54.6%. Consequently, in the case of MITF, TRP-1, TRP-2, and tyrosinase, the amount of mRNA expressed decreased as the concentration of the extracts increased. Our results suggested that A. nephrolepis MAX. extracts can be used as a functional cosmetic material by confirming that they can be used as a whitening material.

• The Journal of Korean Medicine
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• v.43 no.2
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• pp.51-60
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• 2022

Objectives: Currently, Korea's medical services are divided into Western medicine and Korean medicine, and people who are not satisfied with the existing treatments are looking for complementary and alternative medicine(CAM). Therefore, this study attempted to confirm patients' perception of the ongoing collaborative treatment and integrated medical service that added CAM to collaborative treatment based on tertiary hospital users. So that we can confirm the expected advantage and disadvantage of integrated medical service system and the necessity of supporting medical expenses for it. Methods: The survey was conducted on 100 people who experienced tertiary hospital treatment and other 100 people who experienced both tertiary hospital treatment and Korean medicine treatment at the same period. The survey was conducted until the number of respondents in both group reached 100. The survey was conducted through e-mail and was conducted from September 27, 2021 to October 8, 2021. Results: For the advantages of collaborative treatment 'increased in psychological stability,' and for disadvantages 'longer time spent for treatment' were the most common. If integrated medical services are implemented in the future, expected advantages include 'consideration of various treatments.' and expected disadvantages include 'increased medical cost.' The needs to expand support for health insurance for integrated medical services were 75.5% among responders. Conclusions: We were able to find out the (expected) advantages and disadvantages of the collaborative medical care and the integrated medical system that medical users experienced or expected, also confirmed positive answers to the expansion of health insurance support for the integrated medical system.

• Korean Journal of Environment and Ecology
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• v.36 no.3
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• pp.303-317
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• 2022

Climate change caused by increased greenhouse gas emissions can alter the natural ecosystem, including the pollination ecosystem and agricultural ecology, which are ecological interactions between potted insects and plants. Many studies have reported that populations of wild bees, including bees and wasps (BW), which are the key pollinators, have gradually declined due to climate change, leading to adverse impacts on overall biodiversity, ultimately with agribusinesses and the life cycle of flowering plants. Therefore, we could infer that the rising temperature in Korean Peninsula (South Korea) due to global warming has led to climate change and influenced the wild bee's ecosystem. In this study, we surveyed the distributional pattern of BW (Superfamily: Apoidea, Vespoidea, and Chrysidoidea) at 51 sites from 2017 (37 sites) to 2018 (14 sites) to examine the effects of climatic factors on the nationwide distribution of BW in South Korea. Previous literature has confirmed that their distribution according to forest climate zones is significantly correlated with mean and accumulative temperatures. Based on the result, we predicted the effects of future climate changes on the BW distribution that appeared throughout South Korea and the species that appeared in specific climate zones using Shared Socioeconomic Pathways (SSPs). The distributions of wild BW predicted by the SSP scenarios 2-4.5 and 5-8.5 according to the BIOMOD species distribution model revealed that common and endemic species will shift northward from the current habitat distribution by 2050 and 2100, respectively. Our study implies that climate change and its detrimental effect on the ecosystem is ongoing as the BW distribution in South Korea can change, causing the change in the ecosystem in the Korean Peninsula. Therefore, immediate efforts to mitigate greenhouse gas emissions are warranted. We hope the findings of this study can inspire further research on the effects of climate change on pollination services and serve as the reference for making agricultural policy and BW conservation strategy

• Science of Emotion and Sensibility
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• v.25 no.1
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• pp.3-20
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• 2022

Recently, prior to the commercialization of urban air mobility (UAM), the importance of R&D for air transportation-related industries in urban areas has significantly increased. To create a UAM environment, research is being conducted on personal air vehicles (PAVs). They are key means of air transportation, but research on the physical factors influencing their passengers is relatively insufficient. In particular, because the PAV is expected to be used as a living space for the passengers, research on the effects of the physical elements generated in the PAV on the human body is essential to design an interior space that supports the in-vehicle activities of the passengers. Therefore, the purpose of this study is to derive the constraint factors that affect the human body due to the air navigation characteristics of the PAV and to understand the impact of these constraint factors on the bodies of the passengers performing in-vehicle activities. The results of this study indicate that when the PAV was operated at less than 4,000 ft, which is the operating standard, the constraint factors were noise, vibration, and motion sickness caused by low-frequency motion. These constraint factors affect in-vehicle activity; thus, the in-vehicle activities that can be performed in a PAV were derived using autonomous cars, airplanes, and PAV concept cases. Furthermore, considering the impact of the constraint factors and their levels on the human body, recommended constraint factor criteria to support in-vehicle activities were established. To reduce the level of impact of the constraint factors on the human body and to support in-vehicle activity, the seat's shape and built-in functions of the seat (vibration reduction function, temperature control, LED lighting, etc.) and external noise reduction using a directional speaker for each individual seat were recommended. Moreover, it was suggested that interior materials for noise and vibration reduction should be used in the design of the interior space. The contributions of this study are the determination of the constraint factors affecting the in-vehicle PAV activity and the confirmation of the level of impact of the factors on the human body; in the future, these findings can be used as basic data for suitable PAV interior design.