• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.4
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• pp.296-302
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• 2005

We investigated changes in photosynthetic characteristics of P. davidiana in order to understand damage patterns to photosynthetic apparatus under drought stress. Root sprout saplings of P. davildiana were treated with $0\%,\;2\%,\;5\%,\;and\;10\%$ of 300ml polyethylene glycol (PEG) once a weer far one month. After one month, we measured photosynthetic parameters and analyzed the photochemical and $CO_2$ fixation systems. Photosynthetic rate, stomatal conductance, and respiration rate in the leaves of P. davildiana decreased according to increasing stress strength. In the photochemical system, quantum yield of PSII was reduced by the increment of PEG concentration, The decrease of apparent quantum yield was related to reduction of electron transport. Respiration rate decreased with an increase in PEG concentration, whereas photorespiration rate in the $CO_2$ fixation system increased. In conclusion, photosynthesis of P. davidiana responded sensitively under drought stress, and the sensitivity depended upon the strength of water stress. P. davidiana exhibited an increase of water use efficiency under water stress.

• Korean Institute of Interior Design Journal
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• v.22 no.5
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• pp.152-161
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• 2013

This study is about the visual appreciation by sex with the analysis of time range of observing data which was got through observation experiment with the space of lobby in hospitals. The observation data of the subjects who observed the space include the frequency and time, through which the process of visual appreciation could be evaluated with the definition of the frequency and the time of observation. First, the fact that men had higher frequency of observation than women means the former had more movement than the latter, and another fact of their fewer times can be understood as the time of their staying was shorter. That is, even though the men had more movements of sight, they showed the feature of staying shorter. Second, the rate high and low of observation frequency and times made it possible for observation characteristics to be defined as 'intensive search' 'active search' 'fixed concentration' and 'search wandering.' The definition of understanding this process of visual appreciation can be available for a frame of effective analysis of observation characteristics according to the passage of time. Third, the intense search is the case of 'high frequency' having the feature of high visual appreciation owing to the active visual actions for acquiring information. Men were found to have more intense search which decreased gradually as time passed, while women showed the feature of many times of intense search. Fourth, it was found that with many observation data in a certain range of time the subjects had fixed concentration, where women were found to have repetitive fixed concentration along with the change of observation time while men were seen to have more observation tendency for fixed concentration. Fifth, at the cross tabulation of frequency and times, men had the feature of dispersed visual appreciation while women had more distinction between fixation and movement, which revealed that there is surely the difference between men and women in the process of visual appreciation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6917-6924
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• 2015

The universal nature of humans is formed by the view angle and the visibility range. However, the majority of theories on spatial structure analysis based on the visual perception do neither reflect the view angle nor consider only the flat view angle. Some theories that reflect them is a theory where the part included in the view angle and the part excluded in the view angle have been separated in a dichotomous way, excluding the universal characteristics of humans. This study applied an observing probability to a 3-D visibility analysis theory by conducting a eye-tracking experiment, empirically determining the limits of the field of view, and deriving the observing probability by view angle. In addition, it attempted to identify the probability by manufacturing an application of spacial, visual perception analysis and applying the concept of multiple frustum culling. For the characteristics of observation, the data were measured and collected regarding the walking course for 3 minutes for an optional space, aimed for 33 people as subjects. Subsequently, the data were prepared by analyzing the observation fixation frequency probability.

• Korean Journal of Microbiology
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• v.37 no.2
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• pp.114-119
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• 2001

Many isolates from different forest soil layers did not show appreciable growth on full strength of the conventional nutrient broth (NB medium) but grow on its 100-fold dilution (DNB medium). These isolates were divided into four types according to organic nutrient concentration in the growth medium from $1^{-1}\;to\;10^{-4}$dilution of normal NB medium. Oligotrophic bacteria were type II and type IV which grew in $10^{-4}$ dilution of NB (1 mg C/l) medium. Sixty strains were isolated for obligate oligotrophic bacteria. Chemotaxonomic and phylogenetic characteristics of eleven isolates of acetylene-reducing (nitrogen-fixing) oligotrophic bacteria from forest soil were investigated. They showed similar characteristics: the cellular fatty acid mainly consisted of straight-chain unsaturated $C_{18:1}$ (60-84% of total fatty acids). Ubiquinone Q-10 and a high guanine plus-cytosine content(61-64 mol%) were found. Eleven isolates of nitrogen-fixing oligotrophic bacteria were found to be closely related by full 16S rDNA sequence simility and many common taxonomic traits. Analysis of full 16S rDNA sequences of eleven isolates indicated that they were more closely related to Bradyrhizobium (similarity values: 98.1-98.8%), Agromonas, Nitrobacter, and Afipia.

• Journal of Microbiology and Biotechnology
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• v.31 no.9
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• pp.1218-1230
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• 2021

Cold-adapted plant growth-promoting bacteria (PGPB) with multiple functions are an important resource for microbial fertilizers with low-temperature application. In this study, culturable cold-adapted PGPB strains with nitrogen fixation and phosphorus solubilization abilities were isolated. They were screened from root and rhizosphere of four dominant grass species in nondegraded alpine grasslands of the Qilian Mountains, China. Their other growth-promoting characteristics, including secretion of indole-3-acetic acid (IAA), production of siderophores and ACC deaminase, and antifungal activity, were further studied by qualitative and quantitative methods. In addition, whether the PGPB strains could still exert plant growth-promoting activity at 4℃ was verified. The results showed that 67 isolates could maintain one or more growth-promoting traits at 4℃, and these isolates were defined as cold-adapted PGPB. They were divided into 8 genera by 16S rRNA gene sequencing and phylogenetic analysis, of which Pseudomonas (64.2%) and Serratia (13.4%) were the common dominant genera, and a few specific genera varied among the plant species. A test-tube culture showed that inoculation of Elymus nutans seedlings with cold-adapted PGPB possessing different functional characteristics had a significant growth-promoting effect under controlled low-temperature conditions, including the development of the roots and aboveground parts. Pearson correlation analysis revealed that different growth-promoting characteristics made different contributions to the development of the roots and aboveground parts. These cold-adapted PGPB can be used as excellent strain resources suitable for the near-natural restoration of degraded alpine grasslands or agriculture stock production in cold areas.

• Journal of Biomedical Engineering Research
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• v.43 no.2
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• pp.116-123
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• 2022

This study analyzes the Mechanical properties of a medical bone plate by 3D printing. With the recent development of 3D printing technology, it is being applied in various fields. In particular, in the medical field, the use of 3D printing technology, which was limited to the existing orthosis and surgical simulation, has recently been used to replacement bones lost due to orthopedic implants using metal 3D printing. The field of application is increasing, such as replacement. However, due to the manufacturing characteristics of 3D printing, micro pores are generated inside the metal printing output, and it is necessary to reduce the pores and the loss of mechanical properties through post-processing such as heat treatment. Accordingly, the purpose of this study is to analyze the change in mechanical performance characteristics of medical metal plates manufactured by metal 3D printing under various conditions and to find efficient metal printing results. The specimen to be used in the experiment is a metal plate for trauma fixation applied to the human phalanx, and it was manufactured using the 'DMP Flex 100(3D Systems, USA), a metal 3D printer of DMLS (Direct Metal Laser Sintering) method. It was manufactured using the PBF(Powder Bed Fusion) method using Ti6Al4V ELI powder material.

• Advances in pediatric surgery
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• v.17 no.2
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• pp.125-132
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• 2011

The aim of this study was to compare peritoneal dialysis catheter insertion by the open method to the laparoscopic method. Twenty four laparoscopic and 10 open peritoneal dialysis catheter placements were performed in children between 2001 and 2008. Patient characteristics, operation related data, procedural complications and clinical outcome were compared. Although there were no cases of catheter obstruction, exit site infection or bleeding in the laparoscopic group, compared to the open method, there was no statistically significant difference between the two groups. Catheter removal rate due to complication was high in the open group and catheter survival rate was high in the laparoscopic group. We concluded that laparoscopic peritoneal dialysis catheter placement is feasible in children of all age groups with at least equivalent functional results compared to the open method. An advantage of laparoscopic catheter insertion is removal of the great omentum and easy fixation of the catheter to the abdominal wall.

• Korean Journal of Veterinary Research
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• v.59 no.4
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• pp.175-180
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• 2019

This study was conducted to evaluate and analyze fractures types in wild mammals in Korea. Wild mammals treated at 3 wildlife centers in Korea were included. Of the 63 cases included in this study, water deer was the most common species encountered with fractures. We determined 85 different fracture sites, with maximum lumber vertebral fractures followed by femoral, tibial and pelvic fractures. External skeletal fixator (ESF)-intramedullary (IM) pin (IM+ESF tie-in fixation) was the most common method applied for the surgical treatment of mammals. Lumbar vertebrae and femur were the most common bones involved. The findings of this study are expected to provide information for veterinarians regarding the frequency and characteristics of fractures in wild mammals and serve as a basic database for the types and outcomes of fractures in wild mammals.

• Journal of the Korean Society of Safety
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• v.32 no.4
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• pp.28-33
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• 2017

A sharp curved ballasted track on earthwork that was connected with a direct fixation slab track on steel box railway bridges have been deformed and damaged despite the frequently maintenance by a restoring force of sharp curved rail and track-bridge interaction forces such as axial forces and longitudinal displacement of continuous welded rail(CWR) owing to their structural characteristics, calling for alternatives to improve the structural safety and track irregularity. In this study, the authors aim to prove a cause of deformation for the sharp curved ballasted tracks to enhance the structural safety and track irregularity of ballasted track in service. A track-bridge interaction analysis and a finite-element method analysis for the sharp curved ballasted track were performed to consider the axial force and longitudinal displacement of CWR, the temperature and the effect of restoring force of sharp curved rail. From the results, the deformation of the sharp curved ballasted track with adjusted sleeper spacing from 833mm to 590mm were significantly reduced.

• Journal of Korean Neurosurgical Society
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• v.57 no.1
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• pp.61-64
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• 2015

A number of dynamic stabilization systems have been used to overcome the problems associated with spinal fusion with rigid fixation recently and the demand for an ideal dynamic stabilization system is greater for younger patients with multisegment disc degeneration. Nitinol, a shape memory alloy of nickel and titanium, is flexible at low temperatures and regains its original shape when heated, and the Nitinol shape memory loop (SML) implant has been used as a posterior tension band mostly in decompressive laminectomy cases because the Nitinol implant has various characteristics such as high elasticity and a tensile force, flexibility, and biological compatibility. The reported short-term outcomes of the application of SMLs as posterior column supporters in cervical and lumbar decompressive laminectomies seem to be positive, and complications are minimal except for the rare occurrence of pullout and fracture of the SML. However, there was no report of neurological complications related to neural compression in spite of the use of the loop of SML in the epidural space. The authors report a case of delayed development of radiating pain caused by subsidence of the SML resulting epidural compression.