• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.5C
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• pp.199-210
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• 2012

The effects of tunnelling in weak weathered rock on the behaviour of a pre-existing single pile and pile groups ($3{\times}3$ and $5{\times}5$ pile groups) above a tunnel have been studied by carrying out three-dimensional (3D) elasto-plastic numerical analyses. Numerical modelling of such effects considers the response of the single pile and pile groups in terms of tunnelling-induced ground and pile settlement as well as changes of the shear transfer mechanism at the pile-soil interface due to tunnelling. Due to changes in the relative shear displacement between the pile and the soil at the pile-soil interface with tunnel advancement, the shear stresses and axial pile force distributions along the pile change drastically. Based on the computed results, upward shear stresses are induced up to about Z/L=0.775 from the pile top, while downward shear stresses are mobilised below Z/L=0.775, resulting in a reduction in the axial pile force distribution with depth equivalent to a net increase in the tensile force on the pile. A maximum tensile force of about $0.36P_a$ developed on the single pile solely due to tunnelling, where $P_a$ is the service axial pile loading prior to tunnelling. The degree of interface shear strength mobilisation at the pile-soil interface was found to be a key factor governing pile-soil-tunnelling interaction. Overall it has been found that the larger the number of piles, the greater is the effect of tunnelling on the piles in terms of pile settlement, while changes of the axial pile forces for the piles in the groups are smaller than for a single pile due to the shielding effect. The reduction of apparent allowable pile capacity due to tunnelling-induced pile head settlement was significant, in particular for piles inside the groups.

• Proceedings of the Microbiological Society of Korea Conference
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• 2007.05a
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• pp.120-122
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• 2007

All living organisms use numerous signal-transduction pathways to sense and respond to their environments and thereby survive and proliferate in a range of biological niches. Molecular dissection of these signalling networks has increased our understanding of these communication processes and provides a platform for therapeutic intervention when these pathways malfunction in disease states, including infection. Owing to the expanding availability of sequenced genomes, a wealth of genetic and molecular tools and the conservation of signalling networks, members of the fungal kingdom serve as excellent model systems for more complex, multicellular organisms. Here, we employed Cryptococcus neoformans as a model system to understand how fungal-signalling circuits operate at the molecular level to sense and respond to a plethora of environmental stresses, including osmoticshock, UV, high temperature, oxidative stress and toxic drugs/metabolites. The stress-activated p38/Hog1 MAPK pathway is structurally conserved in many organisms as diverse as yeast and mammals, but its regulation is uniquely specialized in a majority of clinical Cryptococcus neoformans serotype A and D strains to control differentiation and virulence factor regulation. C. neoformans Hog1 MAPK is controlled by Pbs2 MAPK kinase (MAPKK). The Pbs2-Hog1 MAPK cascade is controlled by the fungal "two-component" system that is composed of a response regulator, Ssk1, and multiple sensor kinases, including two-component.like (Tco) 1 and Tco2. Tco1 and Tco2 play shared and distinct roles in stress responses and drug sensitivity through the Hog1 MAPK system. Furthermore, each sensor kinase mediates unique cellular functions for virulence and morphological differentiation. We also identified and characterized the Ssk2 MAPKKK upstream of the MAPKK Pbs2 and the MAPK Hog1 in C. neoformans. The SSK2 gene was identified as a potential component responsible for differential Hog1 regulation between the serotype D sibling f1 strains B3501 and B3502 through comparative analysis of their meiotic map with the meiotic segregation of Hog1-dependent sensitivity to the fungicide fludioxonil. Ssk2 is the only polymorphic component in the Hog1 MAPK module, including two coding sequence changes between the SSK2 alleles in B3501 and B3502 strains. To further support this finding, the SSK2 allele exchange completely swapped Hog1-related phenotypes between B3501 and B3502 strains. In the serotype A strain H99, disruption of the SSK2 gene dramatically enhanced capsule biosynthesis and mating efficiency, similar to pbs2 and hog1 mutations. Furthermore, ssk2, pbs2, and hog1 mutants are all hypersensitive to a variety of stresses and completely resistant to fludioxonil. Taken together, these findings indicate that Ssk2 is the critical interface protein connecting the two-component system and the Pbs2-Hog1 pathway in C. neoformans.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4666-4672
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• 2011

Performance of NOx removal in SCR(Selective Catalytic Reduction) process depends on such various factors as catalyst factors (catalyst composition, catalyst form, space velocity, etc.), temperature of exhaust gas, and velocity distribution of exhaust gas. Especially the flow uniformity of gas stream flowing into the catalyst layer is believed to be the most important factor to influence the performance. In this research, the flow characteristics of a SCR process at design stage was simulated, using 3-dimensional numerical analysis method, to confirm the uniformity of the gas stream. In addition, the effects of guide vanes, baffles, and perforated plates on the flow uniformity for the inside and catalyst layer of the reactor were studied in order to optimize the flow uniformity inside the SCR reactor. It was found that the installation of a guide vane at the inlet duct L-tube part and the installation of a baffle at the upper part is very effective in avoiding chaneling inside the reactor. It was also found that additional installation of a perforated plate at the lower part of the potential catalyst layer buffers once more the flow for very uniform distribution of the gas stream.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.3
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• pp.599-606
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• 2015

Damage of landslide due to earthquake covers a considerable part of total damage due to earthquake. Landslide due to earthquake affects direct damage of human lives and structures, and social system can be paralyzed by losing functions of roads, basic industries, and so on. Therefore, systematic and specialized research examining the factors affecting the slope stability by earthquakes should be needed. However, method of evaluation of slope stability problems due to earthquake contains somewhat uncertainty since many soil properties are predicted or assumed. In this study, influences of change of soil properties such as degree of saturation and cohesion value are analyzed in factor of safety and displacement using seismic landslide hazard maps based on GIS. As the degree of saturation increases or cohesion decreases, it is found that seismic landslide hazard area marked with factors of safety or displacements tends to increase. Therefore, to draw more exact landslide hazard map during earthquake, it is necessary to obtain accurate soil property information preferentially from site investigation data in the field.

• The Journal of the Korea Contents Association
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• v.19 no.11
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• pp.325-336
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• 2019

The purpose of this study is to analyze the structural relationship between internal capabilities and job satisfaction using the 7S model and propose measures to improve management performance through internal factors. For this study, seven research hypotheses were set up, and the survey conducted among members of all professions working in general hospitals in small and medium-sized cities in the provinces. From September 20 to October 20, 2016, 385 people were surveyed, and 327 pieces of data (84.9%) used for the study. Multiple regression analyses were performed to verify the effects of internal capabilities on job satisfaction. The analysis results showed that the explanatory power of the research model was suitable by showing 69.1%, and among the 7S factors, the leadership style (β=.392^**), the organizational structure (β=.129^*), the membership (β=.232^**), and the management technique (β=.204^*) showed a positive influence on job satisfaction. That has been confirmed to affect job satisfaction as the standardized factor values increase. Relationships between strategies, systems, and shared values on job satisfaction could not be identified. Significantly observed in the relationship between some internal capacity factors and job satisfaction is that internal capacity can be used as an alternative to an organization's performance improvement measures. Internal capacity can be affected by various environmental variables, such as establishment classification, size, and location. Further implications will also be provided for measuring future internal satisfaction levels separately from internal and external factors.

• Research in Plant Disease
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• v.15 no.3
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• pp.193-197
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• 2009

Pseudocercospora leaf spot was major disease of grape cultivar 'Campbell Early' in Korea. Leaf spot first appeared in early June and rapidly dispersed to other leaves through rainy season. Disease progress of leaf spot by Pseudocercospora vitis in plastic green house, in the two provinces (Gimje and Gimcheon), were investigated in 2007. Differences of Infected leaves (%) between cultivation systems were observed in field and plastic green house, but there was no difference between provinces. Micro environmental factors, such as temperature and relative humidity, were correlated with infected leaves by PROC REG procedure of SAS (Statistical Analysis System). As a result, regression model best described ($R^2=0.95^{**}$) the infected leaves as a function of the interaction of cumulated temperatures; Y (Infected leaves)=-7.0101+0.0496$\times$20Hcum (Cumulated hour above 20 degree)+0.0208$\times$20cum (Cumulated temperature above 20 degree)-0.2781$\times$25Hcum (Cumulated hour above 25 degree). A statistics model was shown that cumulated hour and temperature above specific degree were critical factor for Pseudocercospora leaf spot on the grapevine leaves in plastic green house.

• Toxicological Research
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• v.33 no.3
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• pp.239-253
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• 2017

Neodymium is a future-oriented material due to its unique properties, and its use is increasing in various industrial fields worldwide. However, the toxicity caused by repeated exposure to this metal has not been studied in detail thus far. The present study was carried out to investigate the potential inhalation toxicity of nano-sized neodymium oxide ($Nd_2O_3$) following a 28-day repeated inhalation exposure in male Sprague-Dawley rats. Male rats were exposed to nano-sized $Nd_2O_3-containing$ aerosols via a nose-only inhalation system at doses of $0mg/m^3$, $0.5mg/m^3$, $2.5mg/m^3$, and $10mg/m^3$ for 6 hr/day, 5 days/week over a 28-day period, followed by a 28-day recovery period. During the experimental period, clinical signs, body weight, hematologic parameters, serum biochemical parameters, necropsy findings, organ weight, and histopathological findings were examined; neodymium distribution in the major organs and blood, bronchoalveolar lavage fluid (BALF), and oxidative stress in lung tissues were analyzed. Most of the neodymium was found to be deposited in lung tissues, showing a dose-dependent relationship. Infiltration of inflammatory cells and pulmonary alveolar proteinosis (PAP) were the main observations of lung histopathology. Infiltration of inflammatory cells was observed in the $2.5mg/m^3$ and higher dose treatment groups. PAP was observed in all treatment groups accompanied by an increase in lung weight, but was observed to a lesser extent in the $0.5mg/m^3$ treatment group. In BALF analysis, total cell counts, including macrophages and neutrophils, lactate dehydrogenase, albumin, interleukin-6, and tumor necrosis factor-alpha, increased significantly in all treatment groups. After a 4-week recovery period, these changes were generally reversed in the $0.5mg/m^3$ group, but were exacerbated in the $10mg/m^3$ group. The lowest-observed-adverse-effect concentration of nano-sized $Nd_2O_3$ was determined to be $0.5mg/m^3$, and the target organ was determined to be the lung, under the present experimental conditions in male rats.

• The Korean Journal of Health Service Management
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• v.1 no.1
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• pp.59-74
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• 2007

Considering the characteristics of the Korean family which maintain a close connection with their patients from the moment of their falling sick to hospitalization to discharge, the family is the most important environmental factor of the social supporting system, and is the important object of the client as well as activity system. The medical social work intends to meet the practical needs of aged chronic patients, providing them and their family with a professional human service. The end of this study is to find out the hardships of both the aged chronic patients and their family as well as their needs for the social welfare service, and to search out the way of comprehensive social work service. The summary of the analysis of the survey is as follows: 1. The needs of aged chronic patients are divided into those of the solution of the problems of falling ill, social welfare program and discharge. Those needs arc affected by the various factors of the types of hospitals, the patients' age, the kinds of insurance, and the supporting systems, etc. Accordingly, the assessment of the needs of the patients are asked to be done comprehensively in accordance with the kinds of diseases and social environments. 2. The importance of the family to the aged chronic patients is evident. The family plays a decisive role in the patients' hospitalization and discharge, the family being an important supporting system and making it necessary to take an approach to client system. The family has difficulty in getting connection of community resources, in adapting to social life after the patient's discharge, and in paying the treatment. The family suffers the secondary hardships more than the burden of the treatment expenses. 3. For this reason various interventions are needed to reduce the stress caused by supporting and nursing patients. Thus the social welfare service for the aged chronic patients and their family needs the following prepositions: 1. It is the characteristics of the aged chronic patients that they need continuous care and that the strengths of the patients and their family cannot be too much emphasized, and that comprehensive assessment based on the connection 'with the community and the mutual interchange 'with the environment, is much emphasized. 2. The family of the aged chronic patient is a resources system as well as a client one. 3. Another characteristic of the aged chronic patients is that with the resources connection in mind, it needs an active intervention of social workers in the community. With these prepositions considered, the development of practical social work service for the aged chronic patients is thought urgently needed.

• Research in Plant Disease
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• v.11 no.2
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• pp.208-212
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• 2005

At the survey of June, 2002, total 294 dead frees were found in 20 ha of Black pine (Pinus thunbergii) forest located in the western coastal region of Korean peninsula. The dead trees were scattered over the 27 place as groups of about ten trees each. As a result of the field survey on the relationship between the conditions of dead trees and the occurrence of fruiting bodies of Rhizina undulata around the dead and/or dying trees, from June 2002 to August 2004 in the four plots, the occurrence of infected trees was observed as a shape of an irregular concentric circle from the first infected tree and R. undulata was found mainly around the dead tree. Because there was no observation of any other insects and pathogens which would kill trees, the cause of tree death in groups was considered owing to R. undulata. From the analysis of the physical and chemical proper ties of the soil collected from the damaged areas, the pH of soil was between 4.6 and 5.8 and the contents of soil nutrients were very low. Any "fire" trace was not found at all the 27 damaged places in the area, Taean, Chungcheongnam-Do, which are generally known as an important factor to initiate development of the disease. Therefore, further examination is needed to verify precisely about other environmental factors related with the group dying of the Black pines in this area beside 'fire'.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.5
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• pp.837-844
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• 2017

Generally, V/C ratio in uninterrupted traffic flow and average travel speed in interrupted traffic flow are utilized as measure of effect for assessing operational situation of roads. The set of road conditions and traffic conditions are considered to be major variables for assessing operational situation in the traffic flow. However, weather conditions such as rainfall also affect the operational situation of roads. The studies reflected by the rainy situation are conducted in the uninterrupted flow, but the related studies are insufficient in the interrupted flow. In this study, the modification factors during rainfall in the interrupted flow were suggested, and the factors could be used when calculating the average travel speed during rainfall in the interrupted flow. By utilizing the data that were investigated in the same road and traffic conditions and the different weather conditions (rainy day or clear day), the modification factors were founded on regression analysis of the travel speed during rainfall as a dependent variable. Modification factors was suggested in dividing peak time, non-peak time, and whole period. Based on this study, the modification factors can be used to complementing the average travel speed model for assessing the operational situation of urban streets during rainfall.