• Ecology and Resilient Infrastructure
• /
• 제5권2호
• /
• pp.59-71
• /
• 2018

Lake Enriquillo, the largest lake in the Dominican Republic, recently has undergone unusual water area changes since 2001 thus it has been affected seriously by local community's livelihood. Earthquakes and seismic activities of Hispaniola plate tectonic coupled with human activities and climate change are addressed as factors causing the increasing. Thus, a thorough study on relationship between lake area changing, and those factors is needed urgently. To do so, this study applied MESMA on MODIS data to extract water area of Lake Enriquillo during 2001 and 2012 bimonthly, with six issues 12-year. MODIS provides high temporal resolution, and its coarse spatial resolution is compensated by MESMA fraction map. The increase in water area was $142.2km^2$, and the maximum lake area was $338.0km^2$ (in 2012). Water areas extracted by two Landsat scenes at two different times with three image classification approaches (ISODATA, MNDWI, and TCW) were used to assess accuracy of MODIS and MESMA results; it indicated that MESMA water areas are same as ISODATA's, less than 0.4%, while the highest difference is between MESMA and TCW, 2.4%. A number of previously formulated hypotheses of lake area change were investigated based on the outcomes of the present study, though none of them could fully explain the changes.

• 대한원격탐사학회지
• /
• 제36권1호
• /
• pp.15-27
• /
• 2020

Accurate knowledge of land use/land cover (LULC) features and their relative changes over upon the time are essential for sustainable urban management. Urban sprawl growth has been always also a worldwide concern that needs to carefully monitor particularly in a developing country where unplanned building constriction has been expanding at a high rate. Recently, remotely sensed imageries with a very high spatial/spectral resolution and state of the art machine learning approaches sent the urban classification and growth monitoring to a higher level. In this research, we classified the Quickbird satellite imagery by object-based image analysis of Dempster-Shafer (OBIA-DS) for the years of 2002 and 2015 at Karbala-Iraq. The real LULC changes including, residential sprawl expansion, amongst these years, were identified via change detection procedure. In accordance with extracted features of LULC and detected trend of urban pattern, the future LULC dynamic was simulated by using land transformation model (LTM) in geospatial information system (GIS) platform. Both classification and prediction stages were successfully validated using ground control points (GCPs) through accuracy assessment metric of Kappa coefficient that indicated 0.87 and 0.91 for 2002 and 2015 classification as well as 0.79 for prediction part. Detail results revealed a substantial growth in building over fifteen years that mostly replaced by agriculture and orchard field. The prediction scenario of LULC sprawl development for 2030 revealed a substantial decline in green and agriculture land as well as an extensive increment in build-up area especially at the countryside of the city without following the residential pattern standard. The proposed method helps urban decision-makers to identify the detail temporal-spatial growth pattern of highly populated cities like Karbala. Additionally, the results of this study can be considered as a probable future map in order to design enough future social services and amenities for the local inhabitants.

• 대한치과기공학회지
• /
• 제39권3호
• /
• pp.145-152
• /
• 2017

Purpose: This study sought to identify changes in the mechanical characteristics and color of zirconia according to different sintering temperatures of the substance. Methods: This study processed some specimens of zirconia into those of $8mm(H){\times}10mm(W){\times}50mm(L){\pm}0.1$ each, and sintered them at $1450{\sim}1600^{\circ}C$ on a $50^{\circ}C-interval$ basis in order to examine how their mechanical characteristics and color are changed. Each specimen sintered using the spectral colorimetric apparatus (Easyshade, VITA, Germany) was observed for each of the color change by sintering temperature. Results: When those specimens were sintered at $1450{\sim}1600^{\circ}C$, they were 0% in absorption ratio and porosity, 20% in shrinkage ratio and $6.10g/cm^3$ in specific gravity. Absorption ration, porosity, shrinkage ratio and specific gravity all didn't vary depending on the sintering temperature. The fracture strength of the specimens was highest or 1037MPa at the sintering temperature of $1550^{\circ}C$ and a little lower or 989MPa at that of $1600^{\circ}C$. No variation in L* value was found depending on the sintering temperature of the specimens, while c* value was highest at that of $1450^{\circ}C$. In addition, h* value was highest when the specimens was sintered at $1550^{\circ}C$. Conclusion: This study could determine how zirconia shows changes in mechanical characteristics and color in accordance with different temperatures of its sintering. It is necessary to supplement the physical data of colored transparent zirconia block which is expected to be widely used in clinical practice.

• Journal of Magnetics
• /
• 제21권2호
• /
• pp.286-292
• /
• 2016

This study evaluates the change of computer tomography (CT) number in the case of the metal artifact reduction (MAR) algorithm, using the phantom. The images were obtained from dual CT using a gammex 467 tissue characterization phantom, which is similar to human tissues. The test method was performed by dividing pre and post MAR algorithm and measured CT values of nonmagnetic materials within the phantom. In addition, the changes of CT values for each material were compared and analyzed after measuring CT values up to 140 keV, using the spectral HU curve followed by CT scan. As a result, in the cases of N rod (trabecular bone) and E rod (trabecular bone), the CT numbers decreased as keV increasing but were constant above 90 keV. In the cases of I rod (dense bone) and K rod (dense bone), the CT numbers also decreased as keV increased but were uniform above 90 keV. The CT numbers from 40 keV to 140 keV were consistent in the cases of J rod (liver), D rod (liver), L rod (muscle), and F rod (muscle). For A rod (adipose), G rod (adipose), B rod (breast) and O rod (breast), the CT numbers increased as keV increased but were constant after 90 keV. The CT numbers from 40 keV to 140 keV were consistent in the cases of C rod (lung (exhale)), P rod (lung (exhale)), M rod (lung (inhale)) and H rod (lung (exhale)). Conclusively, because dual CT exhibits no changes in image quality and is able to analyze nonmagnetic materials by measuring the CT values of various materials, it will be used in the future as a useful tool for the diagnosis of lesions.

• 대기
• /
• 제29권2호
• /
• pp.115-129
• /
• 2019

Surface winds over the ocean influence not only the climate change through air-sea interactions but the coastal erosion through the changes in wave height and direction. Thus, demands on a reliable projection of future changes in surface winds have been increasing in various fields. For the future projections, climate models have been widely used and, as a priori, their simulations of surface wind are required to be evaluated. In this study, we evaluate the climatological mean surface winds over the Korean Waters simulated by five regional climate models participating in Coordinated Regional Climate Downscaling Experiment (CORDEX) for East Asia (EA), an international regional climate model inter-comparison project. Compared with the ERA-interim reanalysis data, the CORDEX-EA models, except for HadGEM3-RA, produce stronger wind both in summer and winter. The HadGEM3-RA underestimates the wind speed and inadequately simulate the spatial distribution especially in summer. This summer wind error appears to be coincident with mean sea-level pressure in the North Pacific. For wind direction, all of the CORDEX-EA models simulate the well-known seasonal reversal of surface wind similar to the ERA-interim. Our results suggest that especially in summer, large-scale atmospheric circulation, downscaled by regional models with spectral nudging, significantly affect the regional surface wind on its pattern and strength.

• Korean Journal of Ophthalmology
• /
• 제32권6호
• /
• pp.445-450
• /
• 2018

Purpose: To compare the tear film lipid layer thickness (LLT) between patients with incomplete nasolacrimal duct obstruction (NLDO) and normal controls and to analyze the changes in tear film LLT and blinking pattern after silicone tube intubation in NLDO patients. Methods: We reviewed the medical records of 68 eyes in 52 incomplete NLDO patients who underwent silicone tube intubation from January 2017 to July 2017. The LLT, blinking pattern, and Meibomian gland image were measured with the LipiView II ocular surface interferometer. The Meibomian gland drop-out ratio was measured using the polygon selection tool in the Image J program. Tear meniscus height, which is the other lacrimal indicator, was assessed with spectral-domain optical coherence tomography. Results: Tear meniscus height was significantly decreased after silicone tube intubation (p < 0.01). Preoperative minimum, maximum, and average LLT values were $62.4{\pm}24.0$, $86.7{\pm}17.9$, and $71.7{\pm}23.3nm$, respectively. Significant changes in the minimum, maximum, and average LLT ($74.8{\pm}23.6$, $98.8{\pm}11.0$, and $91.6{\pm}16.1nm$, respectively) were observed after silicone tube intubation (p < 0.001, p = 0.001, and p < 0.001). The partial blinking/total blinking ratio in 20 seconds and the Meibomian gland drop-out ratio showed no significant change after silicone tube intubation. Conclusions: Overall, the LLT was increased after silicone tube intubation. Silicone tube intubation may be helpful in maintaining LLT with a normalized of amount of tears.

• 대한원격탐사학회지
• /
• 제35권4호
• /
• pp.573-587
• /
• 2019

A multi-temporal approach using remotely sensed time series data obtained over multiple years is a very useful method for monitoring land covers and land-cover changes. While spectral-based methods at any particular time limits the application utility due to instability of the quality of data obtained at that time, the approach based on the temporal profile can produce more accurate results since data is analyzed from a long-term perspective rather than on one point in time. In this study, a multi-temporal approach applying a multi-periodic harmonic model is proposed for classification of remotely sensed data. A harmonic model characterizes the seasonal variation of a time series by four parameters: average level, frequency, phase, and amplitude. The availability of high-quality data is very important for multi-temporal analysis.An satellite image usually have many unobserved data and bad-quality data due to the influence of observation environment and sensing system, which impede the analysis and might possibly produce inaccurate results. Harmonic analysis is also very useful for real-time data reconstruction. Multi-periodic harmonic model is applied to the reconstructed data to classify land covers and monitor land-cover change by tracking the temporal profiles. The proposed method is tested with the MODIS and GOCI NDVI time series over the Korean Peninsula for 5 years from 2012 to 2016. The results show that the multi-periodic harmonic model has a great potential for classification of land-cover types and monitoring of land-cover changes through characterizing annual temporal dynamics.

• The Plant Pathology Journal
• /
• 제38권3호
• /
• pp.212-219
• /
• 2022

Fusarium root rot caused by the soil-borne fungus Fusarium solani is one of the most important fungal diseases of cassava in Thailand, resulting in high yield losses of more than 80%. This study aimed to investigate if the exogenous application of salicylic acid formulations (Zacha) can induce resistance in cassava against Fusarium root rot and observe the biochemical changes in induced cassava leaf tissues through synchrotron radiation based on Fourier-transform infrared (SR-FTIR) microspectroscopy. We demonstrated that the application of Zacha11 prototype formulations could induce resistance against Fusarium root rot in cassava. The in vitro experimental results showed that Zacha11 prototype formulations inhibited the growth of F. solani at approximately 34.83%. Furthermore, a significant reduction in the disease severity of Fusarium root rot disease at 60 days after challenge inoculation was observed in cassava plants treated with Zacha11 at a concentration of 500 ppm (9.0%). Population densities of F. solani were determined at 7 days after inoculation. Treatment of the Zacha11 at a concentration of 500 ppm resulted in reduced populations compared with the distilled water control and differences among treatment means at each assay date. Moreover, the SR-FTIR spectral changes of Zacha11-treated epidermal tissues of leaves had higher integral areas of lipids, lignins, and pectins (1,770-1,700/cm), amide I (1,700-1,600/cm), amide II (1,600-1,500/cm), hemicellulose, lignin (1,300-1,200/cm), and cellulose (1,155/cm). Therefore, alteration in defensive carbohydrates, lipids, and proteins contributed to generate barriers against Fusarium invasion in cassava roots, leading to lower the root rot disease severity.

• Earthquakes and Structures
• /
• 제24권1호
• /
• pp.37-51
• /
• 2023

Türkiye has made significant changes and updates in both seismic risk maps and design codes over time, as have other countries with high seismic risk. In this study, the last two seismic design codes and risk maps were compared for the Aegean Region (Western Türkiye) where the earthquake risk has once again emerged with the 2020 Izmir Earthquake (Mw=6.9). In this study, information about the seismicity of the Aegean Region was given. The seismic parameters for all provinces in the region were compared with the last two earthquake risk maps. The spectral acceleration coefficients of all provinces have increased and differentiated with the current seismic hazard map as a result of the design spectra used on a regional basis have been replaced by the geographical location-specific design spectra. In addition, section damage limits were obtained for all provinces within the scope of the last two seismic design codes. Structural analyses for a sample reinforced-concrete building were made separately for each province using pushover analysis. The deformations in the cross-sections were compared with the limit states corresponding to the damage levels specified in the last two seismic design codes for the region. Target displacement requests for all provinces have decreased with the current code. The differentiation of geographical location-specific design spectra both in the last two seismic design code and between provinces has caused changes in section damages and building performance levels. The main aim of this study is to obtain and compare both seismic and structural analysis results for all provinces in the Aegean Region (Western Türkiye).

• 산업융합연구
• /
• 제21권7호
• /
• pp.83-92
• /
• 2023

유전체 전위장벽방전방식에 의한 플라즈마 젯의 블렛 형상은 인가되는 유량과 전기장의 크기에 따라 달라지고 이러한 변화는 DBD 플라즈마 젯의 밀도차이에 의한 스펙트럼 분포의 차이로 나타난다. 발생된 플라즈마 젯의 스펙트럼의 분석을 통한 활성종의 발생과 강도의 차이는 장치를 활용하는데 있어서 중요한 요소이다. 본 논문에서는 Ar가스를 이용한 대기압 볼륨 DBD방식의 플라즈마 젯 발생장치를 제안된 설계방법에 따라 구성하였다. 플라즈마 젯의 발생을 위한 유량의 의존도를 규명하기 위한 Ar가스의 유동해석을 시뮬레이션을 통해 확인하였고 프로토타입 시스템에서는 MFC를 통한 유량제어를 통해 최적의 플라즈마 젯 불렛형상을 발생시키고 발생된 플라즈마 젯의 특성을 분석하기 위해 스펙트로미터를 이용한 플라즈마 젯의 특성을 분석하였다. 제안된 시스템의 설계방법을 통한 장치에서 최적의 플라즈마 젯 형상 확립방법과 EOS 상에서 활성종에 대한 결과를 확인하였다.