• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.10
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• pp.864-868
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• 2007

Effect of high-temperature annealing on morphology of fully coherent self-assembled InAs quantum dots' grown on Si (100) substrates at $450^{\circ}C$ by atmospheric pressure metalorganic chemical vapor deposition(APMOCVD) was investigated by atomic force microscopy(AFM). When the dots were annealed at 500 - 600$^{\circ}C$ for 15 sec - 60 min, there was no appreciable change in the dot density but the heights of the dots increased along with the reduction in the diameters. In segregation from the InAs quantum dots and/or from the 2-dimensional InAs wetting layer which was not transformed into quantum dots looked responsible for this change in the dot size. However the change rates remained almost same regardless of annealing time and temperature, which may indicate that the morphological change due to thermal annealing is done instantly when the dots are exposed to high temperature annealing.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.54-56
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• 2009

We propose an image change detection algorithm implemented on sensor nodes of the ubiquitous sensor network(USN). The proposed algorithm was designed for the robust detection of image changes regardless of the continuously changing ambient illumination environment. Morphological lowpass filter was used for estimating the illumination component in order to reduce computational burden instead of the existing Gaussian lowpass filter. The decision of the change detection is based on the result of threshold of difference image between two consecutive images. We also propose a new thresholding method using precalculated histogram information. The proposed algorithm was implemented on the MSP430 16bit microprocessor.

• Journal of the Korean Ceramic Society
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• v.49 no.5
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• pp.427-431
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• 2012

The $TiO_2$ foam synthesized using freeze-casting is a promising photocatalyst and photovoltaic electrode for a variety of energy applications, because the freeze-casting technique is easy to use, cheap, and suitable for mass-production. Despite its several advantages, little scientific information is available on the processing and morphology of the $TiO_2$ foams processed by freeze-casting. In particular, no systematic study has been performed on the microstructural evolution and morphological change of the rutile-phase $TiO_2$ foams during sintering. Therefore, in the present study, several $TiO_2$ foam samples were produced using the freeze-casting technique, which were then sintered at a relatively high temperature of $1200^{\circ}C$ for 1, 2, and 4 h to compare the morphological changes in the microstructure and to understand the effects of processing parameters of the rutile-phase $TiO_2$ foams. The foam ligament size increased near linearly with increasing sintering time whereas the average pore size decreased only slightly with increasing sintering time, with changes in particle morphology from sphere to rod and complete phase transformation from anatase to rutile.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1523_1524
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• 2009

Inkjet technology has various merits as a direct patterning process in plenty of industrial applications, but critical issue such as coffee ring effect should be overcome for the application to an industrial manufacturing process. In this paper, we introduced the morphological analysis of inkjet printed pattrerns on the characristics of inks and substrates. In case of Triethlene Glycol Monoethly Ether based ink, the coffee ring effect was observed. However, an ethanol based ink showed the round shaped morphology under the same printing conditions and surface conditions. An ink consisted of the solvent with high boiling point results in coffee ring effect. This experimental results showed that the morphological change of the printed droplet is caused by the main solvent of ink, rather than the metal content, viscosity and surface tension.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.1
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• pp.39-49
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• 2014

Morphological and positional characteristics of anchovy aggregations, confirmed by trawling, were examined in two locations of the southern part of theWest Sea (T1) and the western side of South Sea (T11) of South Korea. Morphological characteristics (mean length, height and area) of the anchovy aggregations at T1 were smaller than those at T11, however the positional characteristics (distributional depth and bottom depth) of the aggregations at T1 were larger than those at T11. Diverse dataset such as the ship's cruise track, the cruse map, and interpolated three-dimensional-like water temperature were visualized in multiple dimensions. For a comprehensive understanding of the anchovy aggregations within their surrounding circumstances, the interpolated water temperature transferred to the location of anchovy aggregations at both stations were visualized based on geospatial information. Using quantitative investigation, the overall range of change in water temperature and salinity of anchovy aggregations at stations was considerably small. However, the water temperature and salinity of anchovy aggregations at T11 were somewhat higher than those at T1.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.275-279
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• 2002

Change Detection is a useful technology that can be applied to various fields, taking temporal change information with the comparison and analysis among multi-temporal satellite images. Especially, Change Detection that utilizes high-resolution satellite imagery can be implemented to extract useful change information for many purposes, such as the environmental inspection, the circumstantial analysis of disaster damage, the inspection of illegal building, and the military use, which cannot be achieved by low- or middle-resolution satellite imagery. However, because of the special characteristics that result from high-resolution satellite imagery, it cannot use a pixel-based method that is used for low-resolution satellite imagery. Therefore, it must be used a feature-based algorithm based on the geographical and morphological feature. This paper presents the system that builds the change map by digitizing the boundary of the changed object. In this system, we can make the change map using manual or semi-automatic digitizing through the user interface implemented with a floating window that enables to detect the sign of the change, such as the construction or dismantlement, more efficiently.

• Journal of Korea Water Resources Association
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• v.52 no.2
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• pp.163-172
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• 2019

The linear and cross-sectional shapes of the natural river channel are subjected to continuous changes in time and space due to the interaction with the flow of water and sediment transport. This study aims to investigate the morphological characteristics and change patterns of river channel quantitatively for the middle reach of Nakdong River, which has undergone large scale riverbed dredging and construction work, as Four Major River Restoration Project. A series of bathymetry and near-river survey has been conducted to obtain the detailed terrain information for the study area. The properties related to the linear and cross-sectional characteristics of river channel have been calculated based on the filed survey data and analyzed with comparing the survey data obtained in 2012 for the project completion. Since there has not been enough time for meaningful terrain change to take place, it was not possible to extract special tendency in the degree and aspect of terrain change. However, it is necessary to make regular examinations to the patterns and degree of river channel change using the proposed methodology.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.27 no.2
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• pp.43-53
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• 2024

This study attempted to elucidate the ecological niches and influencing environmental factors of Quercus variabilis and Quercus acutissima, which are representative deciduous broad-leaved trees in Korean forests, taxonomically close and genetically similar, under climate change conditions. Under climate change conditions induced by increased CO₂ and temperature, soil moisture and nutrient environments were manipulated in four gradients. At the end of the growing, plants were harvested to measure growth responses, calculate ecological niches, and compare them with those of the control. Eperimental plants were grown for 180 days in a glass greenhouse designed with four gradients each for soil moisture and nutrient environments under climate change conditions induced by increased CO₂ and temperature. After harvesting, growth responses of leaf traits were measured, ecological niches were calculated, and these were compared with those of the control groups. Furthermore, the responses of the two species' populations were interpreted using principal component analysis(PCA) based on leaf trait measurements. As a result, under climate change conditions, the ecological niche breadth for moisture environment was broader for Quercus variabilis than Quercus acutissima, whereas for the nutrient environment, Quercus acutissima exhibited a broader niche breadth than Quercus variabilis. And the rate of change in ecological niche breadth due to climate change decreased for Quercus variabilis in both moisture and nutrient environments, while for Quercus acutissima, it increased in the moisture environment but decreased in the nutrient environment. Additionally, in terms of group responses, both Quercus variabilis and Quercus acutissima expanded their ecological niches under climate change conditions in both soil moisture and nutrient conditions, with Quercus acutissima exhibiting a broader niche than Quercus variabilis under nutrient conditions. These results indicate that the changes in leaf morphological characteristics and the responses of individuals reflecting them vary not only under climate change conditions but also depending on environmental factors.

• Microbiology and Biotechnology Letters
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• v.24 no.3
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• pp.261-267
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• 1996

To examine the potential utilization of chitosan, the biodegradable natural polymer, as a control agent of apple white rot caused by Botryosphaeria dothidea in a new control measure by coating it on the diseased branches, the various antifungal activities of chitosan was investigated. Chitosan showed significant inhibitory effect on the mycelial growth of B. dothidea, along with the morphological changes including hyphal swelling and ultrastructural changes on solid PDA medium. In liquid PD broth medium, the chitosan showed more significant effect on the growth of B. dothidea also forming cell clusters indicating affection on the hyphal extension. The growth of B. dothidea was inhibited more than 90% at the concentration of 1.0 mg/ml. Chitosan also detained the spore germination and induced the morphological change of germ tubes. Glucosamine, monomer of chitosan, did not affect on the growth of B. dothidea indicating the antifungal activity was caused by chitosan polymer.

• ALGAE
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• v.20 no.4
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• pp.325-331
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• 2005

Populations of Campylaephora borealis (Nakamura) Seo, Cho et Boo and C. crassa (Okamura) Nakamura show a year-around occurrence of all life-history stages. Such a concurrency of life-history stages produces problems in recognizing species in the field. Here, we invesitgated the morphological variation and life-history stages of both species using a statistical character analysis. Life-history stage was correlated with the seawater temperature in C. borealis, whereas it was dependant on biomass in C. crassa. Thalli had dichotomous branches with adaxial branchlets. The statistics showed that the seasonal change in morphology of C. borealis was significantly different from that of C. crassa in seven qualitative characters and five quantitative characters (p < 0.001), although six quantitative features including tetrasporangial size were similar in both species. The morphological difference between the two species may be due to the annual variation of branchlet number and the variance of branch subangle.