• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.463-467
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• 2004

Rosette-type diffusers with four-ports per riser are constructed in relatively shallow water in Korea. However, the trajectorial bending phenomena due to lower-pressure inside the surrounded buoyant jets on the riser was not considered in most models and was not observed without any experimental results. The buoyant jet behavior affected by the bending effect where there have been growing interests need to be verified experimentally and need to be preceded in the analysis of the characteristics of the buoyant jets oil a riser. The hydraulic model experiments have been carried out to investigate the characteristics of the behavior of horizontal buoyant jets discharged from a Rosette-type riser with four ports as well as single port over a certain range of the experimental conditions including initial momentum and initial buoyancy using LIF (Laser Induced Fluorescence) system to obtain concentration fields. The intensity of the fluorescent light in each pixel on the images obtained from LIF system with the tracer of Rhodamine H was converted to the local dye concentration with a set of calibration procedures to account for the non-uniform distribution of light intensity and the attenuation of light energy by water medium. The experimental results shows that the trajectories from Your ports tend to bend more and more to the inner side with the increase of the densimetric Froude number while the buoyant jet from a single port rises up without any bending phenomena. The previous models, VISJET and Seo et al. (2002), do not simulate the trajectories well except the region before the bending section. This study will focus on the analysis of the behavior of the buoyant jets for mainly a Rosette-type riser by conducting hydraulic model experiments using LIF system.

• Journal of the Korean GEO-environmental Society
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• v.14 no.3
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• pp.5-11
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• 2013

The primary objective of this research is to evaluate the behavior of a bridge substructure subjected to scouring during flood. A finite element (FE) study was carried out on a substructure modeled using the standard section specified for highway bridges. The three-dimensional FE model consists of non-linear springs with tri-axial load capacities at the base in order to consider the loss of bearing capacity of the substructure by local scour phenomenon. Various time varying loading conditions and scouring patterns were considered in the analysis. The results indicate a change in the structural behavior of substructure depending on the eroded area and pattern. The outcome of this research will be useful to suggest basic design guidelines for ground sills of the bridge substructure.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.2
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• pp.105-114
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• 2018

In this paper, the computer simulations are carried out by using the peridynamic theory model with various conditions including quasi-static loads, dynamic loads and crack propagation, branching crack pattern and isotropic materials, orthotropic materials. Three examples, a plate with a hole under quasi-static loading, a plate with a pre-existing crack under dynamic loading and a lamina with a pre-existing crack under quasi-static loading are analyzed by computational simulations. In order to simulate the quasi-static load, an adaptive dynamic relaxation technique is used. In the orthotropic material analysis, a homogenization method is used considering the strain energy density ratio between the classical continuum mechanics and the peridynamic. As a result, crack propagation and branching cracks are observed successfully and the direction and initiation of the crack are also captured within the peridynamic modeling. In case of applying peridynamic used homogenization method to a relatively complicated orthotropic material, it is also verified by comparing with experimental results.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.3
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• pp.51-58
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• 2007

The present study surveyed 750 graduate and undergraduate students who were living or not living in Gangwon province concerning the characteristics of disasters in Gangwon province, people's consciousness of disaster prevention, etc. According to the results of analysis, all the respondents thought that the possibility of disasters is higher in Gangwon province(74.0%) than in any other province. Compared to non-residents, Gangwon province residents tended to perceive that the possibility of storm and flood disasters and forest fires is high in Gangwon province. As to reasons for frequent disasters in Gangwon province, the respondents mentioned disadvantageous natural conditions, the shortage of disaster prevention facilities and local residents' low consciousness of disaster prevention. As to methods for enhancing people's consciousness of disaster prevention in Gangwon province, they considered essential the expansion of disaster prevention facilities and education on disaster prevention. In particular, 62.1% of the respondents did not have experiences in disaster education. This suggests the necessity for extending disaster education.

• Journal of the Korea Society for Simulation
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• v.20 no.1
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• pp.97-105
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• 2011

In rivers and streams, biofilms are thin layers of greenish-brown slime attached to rocks, plants, and other surfaces. Biofilms play key roles in primary production and cycling of nutrients, water quality remediation, suspended sediment removal, and energy flow to higher trophic levels. In the present study, we developed a two-dimensional cellular automata model to simulate mixed biofilms of toxin-sensitive and toxin-producing species in hydrodynamic flow. The flow was generated by a stochastic process for uniform flow and by using the Navier-Stokes equation for non-uniform flow. Minimized local rules governing reproduction and mortality of the species were executed in the self-organizing processes to elucidate interactions between toxin-producing and toxin-sensitive species in competition over nutrients. We briefly discuss the morphology of the simulated biofilm under different flow conditions.

• Structural Engineering and Mechanics
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• v.52 no.3
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• pp.613-632
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• 2014

In the early design stage of ships, the two most important structural analyses are performed to identify the structural capacity and safety. The first step is called global strength analysis (longitudinal strength analysis or hull girder strength analysis) and the second step is local buckling analysis (stiffened panel strength analysis). This paper deals with the ultimate strength performance of Arctic Sea Route-going commercial ships considering the effect of low temperature. In this study, two types of structural analyses are performed in Arctic sea conditions. Three types of ship namely oil tanker, bulk carrier and container ship with four different sizes (in total 12 vessels) are tested in four low temperatures (-20, -40, -60 and $-800^{\circ}C$), which are based on the Arctic environment and room temperature ($20^{\circ}C$). The ultimate strength performance is analysed with ALPS/HULL progressive hull collapse analysis code for ship hulls, then ALPS/ULSAP supersize finite element method for stiffened panels. The obtained results are summarised in terms of temperature, vessel type, vessel size, loading type and other effects. The important insights and outcomes are documented.

• Molecules and Cells
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• v.40 no.7
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• pp.450-456
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• 2017

Mammalian physiology and behavior are regulated by an internal time-keeping system, referred to as circadian rhythm. The circadian timing system has a hierarchical organization composed of the master clock in the suprachiasmatic nucleus (SCN) and local clocks in extra-SCN brain regions and peripheral organs. The circadian clock molecular mechanism involves a network of transcription-translation feedback loops. In addition to the clinical association between circadian rhythm disruption and mood disorders, recent studies have suggested a molecular link between mood regulation and circadian rhythm. Specifically, genetic deletion of the circadian nuclear receptor Rev-$erb{\alpha}$ induces mania-like behavior caused by increased midbrain dopaminergic (DAergic) tone at dusk. The association between circadian rhythm and emotion-related behaviors can be applied to pathological conditions, including neurodegenerative diseases. In Parkinson's disease (PD), DAergic neurons in the substantia nigra pars compacta progressively degenerate leading to motor dysfunction. Patients with PD also exhibit non-motor symptoms, including sleep disorder and neuropsychiatric disorders. Thus, it is important to understand the mechanisms that link the molecular circadian clock and brain machinery in the regulation of emotional behaviors and related midbrain DAergic neuronal circuits in healthy and pathological states. This review summarizes the current literature regarding the association between circadian rhythm and mood regulation from a chronobiological perspective, and may provide insight into therapeutic approaches to target psychiatric symptoms in neurodegenerative diseases involving circadian rhythm dysfunction.

• Journal of Pharmacopuncture
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• v.18 no.2
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• pp.76-85
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• 2015

Objectives: Radix Ginseng has been traditionally used as an adaptogen that acts on the adrenal cortex and stimulates or relaxes the nervous system to restore emotional and physical balance and to improve well-being in cases of degenerative disease and/or old age. Radix Ginseng has been used for a long time, but the safety of ginseng pharmacopuncture needs testing. This study was done to analyze the single-dose toxicity of water- soluble ginseng pharmacopuncture (GP) intramuscular injections in rats. Methods: All experiments were performed at Biotoxtech, an institution authorized to perform non clinical studies under the regulations of Good Laboratory Practice (GLP). Each group contained 10 Sprague-Dawley rats, 5 males and 5 females. GP was prepared in a sterile room at the Korean Pharmacopuncture Institute under regulations of Good Manufacturing Practice (GMP). GP dosages were 0.1, 0.5 and 1.0 mL for the experimental groups; normal saline was administered to the control group. The animals general condition was examined daily for 14 days, and the rats were weighed on the starting day and at 3, 7 and 14 days after administration of the pharmacopuncture. Hematological and biochemistry tests and autopsies were done to test the toxicological effect of GP after 14 days. This study was performed with approval from the Institutional Animal Ethics Committee of Biotextech. Results: No deaths were found in this single-dose toxicity test of intramuscular injections of GP, and no significant changes in the general conditions, body weights, hematological and biochemistry tests, and autopsies were observed. The local injection site showed no changes. Based on these results, the lethal dose was assumed to be over 1.0 mL/animal in both sexes. Conclusion: These results suggest that GP is relatively safe. Further studies, including a repeated toxicity test, are needed to provide more concrete evidence for the safety of GP.

• International Journal of Computer Science & Network Security
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• v.21 no.12
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• pp.316-322
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• 2021

The problem of corruption and the spread of corruption crime today is not only one of the main social problems, but also an obstacle to the implementation of reforms in Ukraine. Given the complexity, scale and diversity of the impact of corruption, it is an undisputed threat to national security. At the state level, corruption threatens, firstly, state security as a result of its spread in public authorities and the combination of political and business spheres; secondly, in the domestic political sphere as a result of non-compliance and violation by officials of public authorities and local governments of the laws of Ukraine; thirdly, in the economic sphere as a result of the dominance of personal interests of civil servants over national ones; fourthly, in other spheres, namely, military, social, ecological, informational, foreign policy, etc. The origins of corruption are diverse and are formed not only in the country but also abroad. The current corruption threat is the result of the country's ineffective domestic and foreign anticorruption policies. Acceleration of the spread and manifestation of external corruption threats is associated with a number of unresolved foreign policy issues against the background of the development of globalization and integration processes, in particular: economic and financial dependence of the country on international financial institutions and organizations; as well as from foreign countries that pose a potential threat due to their ambitious plans to expand our country; unresolved issues regarding the international legal consolidation of borders, etc. It is noted that the current conditions for the development of state security, due to new challenges and threats, need to improve and implement new measures to prevent corruption as a negative impact of the main threats to national economic security. As a result of the study, the main measures to counter the main threats to the economic security of the state were identified.

• Journal of Korean Society of Rural Planning
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• v.29 no.3
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• pp.53-67
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• 2023

In this study, the problem of the idleness of public buildings in rural areas is seriously emerging, but there are no clear standards for assessing the utilization of these buildings. Therefore, this study endeavors to investigate the actual state of idleness of buildings created by rural area development projects based on the criteria for each type. As part of this study, rural facilities were selected in two locations in Sangju City and Miryang City among the target areas of the Rural Agreement. Utilization evaluation criteria were developed to identify the conditions of underutilization. In order to determine the utilization pattern for each facility type, an in-depth interview with the operator and an inspection of the facility were conducted. Based on the analysis, the degree of utilization (e.g., low use, non-use, etc.) was different for each facility type, and among the four facility types (rural tourism, culture and welfare, exercise and recreation, income-based), rural tourism was rated as the least efficient. It has been found that the operating entity's capacity has a significant influence on the utilization of facilities. Socioeconomic factors, such as a decrease in utilization rates, are greatly influenced by the operating entity's capacity. Therefore, support from local governments as well as the national level is required to recycle idle facilities. Lastly, this study suggests the need for different standards for utilization, depending on the type of facility. This moves beyond checking the degree of idleness by the same standard that was previously implemented.