• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10245-10250
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• 2015

Background: Glucocorticoids are commonly co-administered with chemotherapy to prevent drug-induced allergic reactions, nausea, and vomiting, and have anti-tumor functions clinically; however, the distinct effects of GC on subtypes of tumor cells, especially in breast cancer cells, are still not well understood. In this study, we aimed to clarify the effect of GC on subtypes of T47D breast cancer cells by focusing on apoptosis, cell organization and migration, and underluing molecular mechanisms. Materials and Methods: The cell scratch test was performed to observe the cell migration rate in T47D cells treated with dexamethasone (Dex). Hoechst and MTT assays were conducted to detect cell survival and rhodamine-labeled phalloidin staining to observe cytoskeleton dynamics. Related factors in the AKT/mTOR pathway were determined by Western blotting. Results: Dex treatment could effectively inhibit T47D breast cancer cell migration with disruption of the cytoskeletal dynamic organization. Moreover, the effect of Dex on cell migration and cytoskeleton may be mediated by AKT/mTOR/RhoA pathway. Although Dex inhibited T47D cell migration, it alone may not induce cell apoptosis in T47D cells. Conclusions: Dex in T47D human breast cancer cells could effectively inhibit cell migration by disrupting the cytoskeletal dynamic organization, which may be mediated by the AKT/mTOR/RhoA pathway. Our work suggests that glucocorticoid/Dex clinical use may prove helpful for the treatment of breast cancer metastasis.

• Strategy21
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• s.42
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• pp.83-113
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• 2017

After defeat in World War II, Japan's Peace Constitution committed the country to forego the acquisition of offensive military capabilities. However, in the midst of the post-cold war period, Japan began to change its security posture in line with the so-called 'normal state theory', which called for a more robust defense posture and expanded security activities. The second Abe administration promoted these security policies by issuing a National Security Strategy as well as a new National Defense Program Outline(NDPO) in 2013 and by establishing new security institutions such as the National Security Council. The Abe administration also adopted the new concept of a 'Unified Mobile Defense Force' in the 2013 which replaced the 'Dynamic Defense Force' as a new criteria for the Self-Defense Force's acquisition of military capabilities. In this new concept of military capabilities, the Ground Self-Defense Force is planning to replace existing divisions with mobile divisions and to form 'Amphibious Rapid Deployment Bridge' for the first time in 2018, which has long been taboo in Japan. Japan has experience a Marine Corps in the past. Likewise, an offensive changes in the military strategy can change the spectrum of strategy and 'Amphibious Rapid Deployment Bridge' plays a big role in this. Furthermore, Japan is increasing the Coast Guard's budget and capabilities in preparation for contingencies around the Senkaku islands (called the Diaoyu in Chinese). The South Korea navy should utilize Japan's changing security posture to deter immediate threat such as North Korea's military provocations and potential enemy threat such as China, Japan, Russia.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.6
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• pp.74-83
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• 2008

As urban residents' standard of living has recently risen, efforts to improve urban landscapes have increased. It is very important to manage streetscapes to improve the urban landscape because they are one of the essential elements in city construction and urban landscaping. This study focuses on the indicators that manage streetscapes more accurately and realistically. To achieve this purpose, this study used dynamic simulations considering shape and layout of buildings, the primary factors in streetscapes. This study can be summarized as follows: 1. Two indicators to manage streetscape were investigated in previous studies: one to increase visual openness and the other to reduce visual overstimulation. These indicators had high correlation with scenic beauty. Therefore, increasing openness and reducing overstimulation are essential to improve streetscapes. 2. Two household tower type buildings should be arranged along roadsides to increase openness and scenic beauty. However, low tower buildings with two household are not suitable along roadsides because they create monotony and intervals are needed between buildings. 3. To increase openness, the angled arrangement of buildings is suggested $75^{\circ}{\sim}90^{\circ}(105^{\circ}{\sim}135^{\circ})$ for low buildings, $30^{\circ}{\sim}45^{\circ}(135^{\circ}{\sim}150^{\circ})$ for mid-sized buildings, and $75^{\circ}{\sim}90^{\circ}(105^{\circ}{\sim}135^{\circ})$ for high buildings. 4. To reduce overstimulation, the height and setback control regulations should be at an angle of less than $45^{\circ}$. This study suggests more accurate management guidelines by organizing the indicators that could effectively manage streetscapes and by overcoming limitations of reality shown in a static simulation.

• Polymer(Korea)
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• v.24 no.1
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• pp.105-112
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• 2000

Using a commercial epoxy/carbon fiber composite prepreg (DMS 2224) as a model system, the cure kinetics of vitrifying thermoset system were analyzed by isothermal and dynamic-heating experiments. Focusing on the processing condition of high performance composite systems, a phenomenological kinetic model was developed by using differential scanning calorimetry (DSC) and reaction kinetics theories. The model system exhibited a limited degree of cure as a function of isothermal temperature seemingly due to the diffusion-controlled reaction rates. The diffusion-controlled cure reaction was incorporated in the development of the kinetic model, and the model parameters were determined from isothermal experiments. The first order reaction was confirmed from the characteristic shape of isothermal cure thermograms, and the activation energy wes 78.43 kJ/mol. Finally, the proposed model was used to predict a complex autoclave thermal condition, which was composed of several isothermal and dynamic-heating stages.

• Journal of Korean Society of Rural Planning
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• v.26 no.3
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• pp.57-65
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• 2020

Agricultural research and development (R&D) investment has contributed not only to agriculture but also to the overall economic growth of the country. The recent arrival of the fourth industrial revolution has raised the need for agricultural R&D as a preparation. Agriculture R&D is directly related to the fourth industrial revolution in the agricultural and livestock sectors that utilize big data, robots, artificial intelligence and cloud. Meanwhile, subsidies or grants are considered the most widely used means of policy. Therefore, in light of the current situation in which Chinese agriculture values R&D investment, this study attempted to analyze the dynamic relationship between variables by establishing a model of agricultural environment subsidy representing the role of government, agricultural technology progress representing existing agricultural R&D investment, agricultural income representing agricultural development and total agricultural output. The analysis results showed that each variable's reaction to the rise in China's agricultural R&D investment has a positive effect on agricultural development, in line with the theory that the investment in science and technology in the agricultural sector has a positive effect. In addition, the response of each variable to China's rising agricultural environment subsidy is shown to have a positive relationship, which can also be said to be in line with the theory that the government's market-friendly intervention is beneficial to economic development.

• Journal of the Korean Geotechnical Society
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• v.36 no.6
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• pp.17-34
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• 2020

In response spectrum analysis of pile-supported structure, an amplified seismic wave should be used as the input ground acceleration through the site-response analysis. However, each design standard uses different input ground acceleration criteria, which leads to confusion in determining the appropriate input ground acceleration. In this study, the ground accelerations were calculated through dynamic centrifuge model test, and the response spectrum analysis was performed using the calculated ground acceleration. Then, the moments derived from the test and analysis were compared, and a method for determining the appropriate input ground acceleration in response spectrum analysis was presented. Comparison of the experimental and simulated results reveals that modeling of the ground using elastic springs allows proper simulation of the natural period of the structure, and the use of a seismic wave that is amplified at the ground surface as the input ground acceleration provided the most accurate results for the response analysis of pile-supported structures in sands.

• Journal of Technology Innovation
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• v.29 no.2
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• pp.1-30
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• 2021

Recent years have witnessed various attempts of firms to acquire new knowledge. Purchasing intellectual property or merger and acquisition (M&A) can be such attempts, but joint venture can also be an effective way internalizing new complementary assets from external partners. However, due to difficulties in the formation and implementation of learning strategies, many joint ventures have failed to acquire necessary knowledge. In this respect, based on contingency theory and dynamic capability, the current research aims to investigate the failure case of knowledge transfer in an international joint venture - KEFICO established by Hyundai motors and BOSCH. Case firm optimized for hardware technology but did not establish a differentiated learning strategy and organizational structure to acquire software skills, which are intellectuals of different natures. Due to this inconsistency, it was not able for KEFICO to absorb new type of knowledge (skills related to engine control system). This study suggests the theoretical framework illustrating the case and provides some important implications for organizational learning.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.6
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• pp.405-413
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• 2019

Deployable structures are widely used for space mission because of their advantages in storage and transportation coming from its transformability of configuration. The space structures should be designed with high stiffness to withstand the various types of disturbance that they encounter during operation. Especially for the deployable structures, the internal forces loaded on the component or the stiffness at its deployed configuration should be analyzed since they usually consist of the thin and light structures. In this paper, a dynamic model of the scissors structure is established and its deployment behavior is analyzed, especially focusing on the deployment speed and the internal force on each joint. In addition, modal analysis is carried out for the 1-stage and 2-stage scissors structures in order to analyze the stiffness of the scissors structure based on its deployed configuration. The fundamental mode shapes and natural frequencies are analyzed and discussed.

• Earthquakes and Structures
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• v.22 no.3
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• pp.245-261
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• 2022

Key questions to researchers interested in nonlinear analysis of skeletal structures are whether the distributed plasticity approach - albeit computationally demanding - is more reliable than the concentrated plasticity to adequately capture the extent and severity of the inelastic response, and whether force-based formulation is more efficient than displacement-based formulation without compromising accuracy. The present research focusing on performance-based seismic response of mid-span concrete bridges provides a pilot holistic investigation opting for some hands-on answers. OpenSees software is considered adopting different modeling techniques, viz. distributed plasticity (through either displacement-based or force-based elements) and concentrated plasticity via beam-with-hinges elements. The pros and cons of each are discussed based on nonlinear pushover analysis results, and fragility curves generated for various performance levels relying on incremental dynamic analyses under real earthquake records. Among prime conclusions, distributed plasticity modeling albeit inherently not relying on prior knowledge of plastic hinge length still somewhat depends on such information to ensure accurate results. For instance, displacement-based and force-based approaches secure optimal accuracy when dividing, for the former, the member into sub-elements, and satisfying, for the latter, a distance between any two consecutive integration points, close to the expected plastic hinge length. On the other hand, using beam-with-hinges elements is computationally more efficient relative to the distributed plasticity, yet with acceptable accuracy provided the user has prior reasonable estimate of the anticipated plastic hinge length. Furthermore, when intrusive performance levels (viz. life safety or collapse) are of concern, concentrated plasticity via beam-with-hinges ensures conservative predicted capacity of investigated bridge systems.

• ALGAE
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• v.38 no.4
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• pp.295-306
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• 2023

Human coronavirus diseases, particularly severe acute respiratory syndrome coronavirus 2, still remain a persistent public health issue, and many recent studies are focusing on the quest for new leads against coronaviruses. To contribute to this growing pool of knowledge and explore the available marine natural products against coronaviruses, this study investigated the antiviral effects of fucoxanthin isolated from Sargassum siliquastrum-a brown alga found on Jeju Island, South Korea. The antiviral effects of fucoxanthin were confirmed in severe acute respiratory syndrome coronavirus 2-infected Vero cells, and its structural characteristics were verified in silico using molecular docking and molecular dynamic simulations and in vitro colorimetric method. Fucoxanthin inhibited the infection in a concentration-dependent manner, without showing cytotoxicity. Molecular docking simulations revealed that fucoxanthin binds to the angiotensinconverting enzyme 2-spike protein (binding energy -318.306 kcal mol^-1) and main protease (binding energy -205.118 kcal mol^-1). Moreover, molecular dynamic simulations showed that fucoxanthin remains docked to angiotensin-converting enzyme 2-spike protein for 20 ns, whereas it breaks away from main protease after 3 ns. Also, the in silico prediction of the fucoxanthin was verified through the in vitro colorimetric method by inhibiting the binding between angiotensinconverting enzyme 2 and spike protein in a concentration-dependent manner. These results indicate that fucoxanthin exhibits antiviral effects against severe acute respiratory syndrome coronavirus 2 by blocking the entry of the virus. Therefore, fucoxanthin from S. siliquastrum can be a potential candidate for treating coronavirus infection.