• Journal of the Korean earth science society
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• v.18 no.6
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• pp.553-558
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• 1997

Colorless and transparent cubic zirconia($Zr_{0.73}Y_{0.27}O_{1.87}$) crystal has been synthesized by the Bridgman-Stock-bager method(also called Skull melting method). $Y_2O_3$ is used as stabilizer. The crystal shows a vitreous luster with a slight oily appearance. Under a polarizing microscope, it shows isotropic nature with no appreciable anisotropism. Mohs hardness value is measured to be $8{\sim}8\frac{1}{2}$ and specific gravity 5.85. Under ultraviolet light it shows a faint white glow. The crystal structure of yttria stabilized zirconia was determined, using single crystal X-ray diffraction techniques to be a cubic symmetry, space group $Fm\overline{3}m({O^5}_h)$ with $a=5.1552(5){\AA}$, $V=136.99(5){\AA}^3$, Z=4, and R=0.0488 for 29 unique reflections. Each zirconium atom is at the center of eight oxygen atoms situated at the corners of a surrounding cube and each oxygen atom is at the center of a tetrahedron of zirconium atoms. So a coordination of 8:4 holds in the structure.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.3
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• pp.35-44
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• 2009

In this study, we intended to develope a simulation program for assessing a building height whether or not acceptable for maintaining the visual quality of a forest landscape. A number of geographical factors were considered within the assessment procedure. As the visual quality of a landscape could vary according to the location of view points, we examined 3 methodologies for setting up the view points. The result for comparison between method of selecting viewpoints was not significantly effecting method of selecting viewpoints. Post hoc test showed a moderately large p-value and no significant differences between groups were observed. The result from a case study indicated that the simulation program is able to estimate an environmentally acceptable building height in an efficient manner. In this study, however, only the geographical factors were considered for the assessment, but forest dynamic information such as stand height was not considered. Thus, in the further study, forest stand height would be necessarily considered to estimate a more reliable and desirable building height.

• Korean Journal of Mineralogy and Petrology
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• v.34 no.2
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• pp.121-131
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• 2021

Magnesium (Mg) present in carbonate minerals as impurities has been used as a geochemical proxy to infer the environmental conditions where the minerals precipitated. The reliability of Mg geochemical proxies requires fundamental understanding of Mg incorporation into minerals based on accurate speciation of Mg ²⁺ in the crystal structure, which is determined mainly by application of X-ray absorption spectroscopy (XAS). However, high uncertainties are involved in interpreting the XAS spectra of minerals containing trace amount of Mg ²⁺. Because density function theory (DFT) can predict an XAS spectrum for a crystal structure, DFT calculations can reduce the uncertainties in the interpretation of the XAS spectrum. In this study, we calculated ab initio Mg K-edge absorption spectra of Mg silicates and (hydr)oxides based on DFT and analyzed the correlation between the calculated spectra and Mg structural parameters. Our ab initio Mg K-edge absorption spectra well reproduced the key features of the experimental spectra. The absorption-edge positions of the calculated spectra showed the weak positive correlation with the average Mg-O bond distance or Mg effective coordination number. The current study shows that DFT-based core-level spectroscopy method is a powerful tool in providing standard Mg K-edge spectra of diverse Mg minerals and determining the Mg chemical species within carbonate minerals.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.25-34
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• 2019

Recently, when a fault occurs at a long-distance point in a LVDC (low voltage direct current) distribution feeder in a light rail system, the magnitude of the current can decrease to less than that of the load current of a light rail system. Therefore, proper protection coordination method to distinguish a fault current from a load current is required. To overcome these problems, this paper proposes an optimal algorithm of protection devices for a LVDC distribution feeder in a light rail system. In other words, based on the characteristics of the fault current for ground resistance and fault location, this paper proposes an optimal operation algorithm of a selective relay to properly identify the fault current compared to the load current in a light rail system. In addition, this paper modelled the distribution system including AC/DC converter using a PSCAD/EMTDC S/W and from the simulation results for a real light rail system, the proposed algorithm was found to be a useful and practical tool to correctly identify the fault current and load current.

• Ecology and Resilient Infrastructure
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• v.9 no.1
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• pp.15-23
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• 2022

This study was conducted to investigate in relation to characteristic of macroinvertebrates in conventional and organic paddy fields. The investigation was conducted five times a year for Suwon, Ansung, Boeun, Gunsan, Gimje, Hamyang, divide into conventional paddy fields and organic paddy fields from 2009 to 2011. The macroinvertebrates collected from the surveyed between conventional and organic paddy fields belonged to 84 species, 47 families, 16 orders, and 6 classes in 3 phyla. In the habitat orientied groups, climbers, swimmers and sprawlers were considerably occupied in conventional and organic paddy fields. In relation to the functional feeding groups, predators such as Odonata, Coleoptera, and Hemiptera were only the highest in paddy field ecosystem, regardless of cultivation method. As a result of community stability analysis, orgainc paddy fields has been identified much as species high resistance and resilience to environmental change in paddy field ecosystem. Species belonging to the I groups is considered to be important in organic paddy field such as Sternolophus rufipes, Hydrochara affinis, Helochares nipponicus, which has high mobility. In conclusion, it was found that the introduction of coleoptera as a food source was higher than that of conventional paddy fields in organic paddy field where primary consumers were abundant such as Chironomidae spp. and Dixidae sp..

• Therapeutic Science for Rehabilitation
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• v.12 no.1
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• pp.7-22
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• 2023

Objective : This study aimed to confirm the research characteristics and quality of single-subject literature among domestic studies that applied interactive metronome (IM) intervention. Methods : Regarding literature search, 11 single-subject studies using IM were selected from an online database from January 2011 to June 2022. Moreover, the general characteristics and quality of the research method were analyzed. Results : The qualitative level of the analyzed literature was above the moderate level. However, intervention blindness and reliability showed low compliance. The ABA design accounted for the largest proportion of methods. Most of the study participants had attention deficit hyperactivity disorder. Attention, balance, bilateral coordination, and timing were checked as dependent variables. The IM-SFT was used most frequently as an evaluation method. The mediation session applied more than 8-10 interventions for 3-11 weeks. The intervention results in all studies indicated functional improvement after intervention. Conclusion : It might be necessary to expand the application of IM interventions to diverse diseases. In addition, there is a need to study the effect on the participants' quality of life and changes in daily life along with dependent variables such as attention and balance

• The Journal of Korean Academy of Sensory Integration
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• v.22 no.1
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• pp.1-14
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• 2024

Objective : This study aimed to investigate the impact of Ayres' sensory integration (ASI) intervention on motor skills and occupational participation of preschool children with attention-deficit/hyperactivity disorder (ADHD). Method : Children with ADHD aged between 4 and 6 years who met the inclusion and exclusion criteria were randomly recruited through screening tests. The subjects were divided into an experimental group (10 subjects) and a control group (8 subjects). The instruments used were the Bruininks-Oseretsky test of motor proficiency-2 (BOT-2), Pediatric Evaluation of Disability Inventory (PEDI), and Goal Attainment Scale (GAS) to evaluate occupational participation. The subjects in the experimental group underwent individual sensory integration therapy according to the ASI principles for 40 minutes twice a week in a total of 16 sessions over eight weeks. The control group did not receive the ASI intervention. Data analysis was performed using the Mann-Whitney U test, chi-squared test, Wilcoxon signed-rank test, and Cohen's d test in SPSS 20.0. Results : The ASI experimental group had significantly higher scores in total motor composite, manual coordination, body coordination, strength, and agility in motor function than the control group (p<.05). The two groups did not differ significantly in terms of occupational participation (PEDI), but GAS scores for individual target activities were significantly higher in the experimental group than in the control group (p<.05). Conclusion : This study shows that the ASI intervention has positive effects on motor skills and occupation participation among preschool children with ADHD.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.3
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• pp.322-331
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• 2003

As the complexity of a 3D game is increased by various factors of the game scenario, it has a problem for controlling the interrelation of the game objects. Therefore, a game system has a necessity of the coordination of the responses of the game objects. Also, it is necessary to control the behaviors of animations of the game objects in terms of the game scenario. To produce realistic game simulations, a system has to include a structure for designing the interactions among the game objects. This paper presents a method that designs the dynamic control mechanism for the interaction of the game objects in the game scenario. For the method, we suggest a game agent system as a framework that is based on intelligent agents who can make decisions using specific rules. Game agent systems are used in order to manage environment data, to simulate the game objects, to control interactions among game objects, and to support visual authoring interface that ran define a various interrelations of the game objects. These techniques can process the autonomy level of the game objects and the associated collision avoidance method, etc. Also, it is possible to make the coherent decision-making ability of the game objects about a change of the scene. In this paper, the rule-based behavior control was designed to guide the simulation of the game objects. The rules are pre-defined by the user using visual interface for designing their interaction. The Agent State Decision Network, which is composed of the visual elements, is able to pass the information and infers the current state of the game objects. All of such methods can monitor and check a variation of motion state between game objects in real time. Finally, we present a validation of the control method together with a simple case-study example. In this paper, we design and implement the supervised classification systems for high resolution satellite images. The systems support various interfaces and statistical data of training samples so that we can select the most effective training data. In addition, the efficient extension of new classification algorithms and satellite image formats are applied easily through the modularized systems. The classifiers are considered the characteristics of spectral bands from the selected training data. They provide various supervised classification algorithms which include Parallelepiped, Minimum distance, Mahalanobis distance, Maximum likelihood and Fuzzy theory. We used IKONOS images for the input and verified the systems for the classification of high resolution satellite images.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.341-348
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• 2013

Maintenance of adequate soil tension or content during the period of crop growth is necessary to support optimum plant growth and yields. A better understanding of soil tension and content for precision irrigation would allow optimal soil water condition to crops and minimize the adverse effects of water stress on crop growth and development. This research reports on a comparison of soil water tension and content variations in differently textured soils over time under drip irrigation using two different water management methods, i.e. pulse time and required water irrigation methods. The pulse time-based irrigation was performed by turning the solenoid valve on and off for preset times to allow the wetting front to disperse in root zone before additional water was applied. The required water estimation method was a new water control logic designed by Rural Development Administration that applies the amount of water required based on a conversion of the measured water tension into water content. The use of the pulse time irrigation method under drip irrigation at a high tension of -20 kPa and high temperatures over $30^{\circ}C$ was not successful at maintaining moisture tensions within an appropriate range of 5 kPa because the preset irrigation times used for water control could not compensate for the change in evapotranspiration during day and night. The response time and pattern of water contents for all of the tested soils measured with capacitance-based sensor probes were faster and more direct than those of water tensions measured with porous and ceramic cup-based tensiometers when water was applied, indicating water content would be a better control variable for automatic irrigation. The required water estimation-based irrigation method provided relatively stable control of moisture tension, even though somewhat lower tension values were obtained as compared to the target tension of -20 kPa, indicating that growers could expect to be effective in controlling low tensions ranging from -10 to -20 kPa with the required water estimation system.

• Research in Plant Disease
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• v.26 no.4
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• pp.264-271
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• 2020

We have developed a simultaneous diagnostic method that can identify both the species of thrips and tomato spotted wilt virus (TSWV) that are problematic in chrysanthemum plants. This is a method of amplifying DNA by performing reverse transcription-polymerase chain reaction by simultaneously adding primers specific to TSWV coat protein (N) gene and primers specific to the internal transcribed spacer 2 region of Frankliniella occidentalis and F. intonsa using total nucleic acid extracted from one thrips. The sizes of DNA fragments for TSWV, F. occidentalis, and F. intonsa were 777, 287, and 367 bp, respectively. These results showed species identification of thrips and whether thrips carrying TSWV can be simultaneously confirmed. Further usefulness of the simultaneous diagnostic method was made from greenhouse survey at chrysanthemum greenhouses in Taean (Chungcheongnam-do) and Changwon (Gyeongsangnam-do) to investigate the identification of thrips species and the rate of thrips carrying TSWV. Of thrips collected from the greenhouses, 83.7% thrips was F. occidentalis and 72.9% F. occidentalis carried TSWV in Taean. Similarly, the diagnostic method showed that 92.2% thrips was F. occidentalis and 84.0% F. occidentalis carried TSWV in Changwon. These results confirm that F. occidentalis is a dominant thrips species and the thrips species plays a crucial role in the transmission of TSWV in chrysanthemum plants in the greenhouses. Taken together, this study showed a simple diagnostic method for thrips identification and epidemiological studies of the timing and spread of TSWV through thrips in chrysanthemum greenhouses in South Korea.