• Korean Journal of Remote Sensing
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• v.38 no.6_2
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• pp.1607-1622
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• 2022

The purpose of this study is to determine the actual performance of cool roof in preventing absorbed solar radiation. The spatial correlation between surface temperature and absorbed solar radiation is the method by which the performance of a cool roof can be understood and evaluated. The research area of this study is the vicinity of Jangyu Mugye-dong, Gimhae-si, Gyeongsangnam-do, where an actual cool roof is applied. FLIR Vue Pro R thermal infrared sensor, Micasense Red-Edge multi-spectral sensor and DJI H20T visible spectral sensor was used for aerial photography, with attached to the drone DJI Matrice 300 RTK. To perform the spatial correlation analysis, thermal infrared orthomosaics, absorbed solar radiation distribution maps were constructed, and land cover features of roof were extracted based on the drone aerial photographs. The temporal scope of this research ranged over 9 points of time at intervals of about 1 hour and 30 minutes from 7:15 to 19:15 on July 27, 2021. The correlation coefficient values of 0.550 for the normal roof and 0.387 for the cool roof were obtained on a daily average basis. However, at 11:30 and 13:00, when the Solar altitude was high on the date of analysis, the difference in correlation coefficient values between the normal roof and the cool roof was 0.022, 0.024, showing similar correlations. In other time series, the values of the correlation coefficient of the normal roof are about 0.1 higher than that of the cool roof. This study assessed and evaluated the potential of an actual cool roof to prevent solar radiation heating a rooftop through correlation comparison with a normal roof, which serves as a control group, by using high-resolution drone images. The results of this research can be used as reference data when local governments or communities seek to adopt strategies to eliminate the phenomenon of urban heat islands.

• Journal of the Korean Orthopaedic Association
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• v.56 no.3
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• pp.208-214
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• 2021

Purpose: Verifying a reliable predictor of the progression of vertebral deformity in patients with acute osteoporotic fractures of the lumbar spine may be useful. A qualitative analysis of the muscle near the spine was performed using magnetic resonance imaging (MRI), and its correlation with a spinal deformity was determined under the hypothesis that the causes of the kyphotic deformity are associated with muscle reduction in the multifidus and erector spinae. Materials and Methods: The study was performed in a retrospective manner using the electronic medical records of patients who presented to the author's institution between January 2007 and March 2018, and were diagnosed with an acute lumbar fracture. The fat infiltration rates of the multifidus and erector spinae were measured using MRI taken at the time of injury, and the mean value was defined as the total fat infiltration rate (TFI). Based on lateral radiographs of the lumbar spine at the one-year follow-up, the loss of height of the vertebral body, the kyphotic angle and the wedge angle were measured. The statistical significance was confirmed by calculating the Pearson correlation coefficient. Results: One hundred twenty-nine patients, of which 30 were male and 99 were female, were examined. The mean age was 71.28 years. The mean T-score was -3.53±0.79 g/cm², and the mean fat infiltration was 15.20%±11.99%. TFI was positively correlated with age (R=0.373, p<0.001), compression rate (R=0.369, p<0.001), and Cobb's angle (R=0.386, p<0.001) after a one year follow-up, but negatively correlated with the BMD score (R=-0.252, p=0.004). As the fracture progressed to the lower lumbar level, the compression rate (R=-0191, p=0.030) and wedge angle (R=-0.428, p<0.001) at the time of injury tended to decrease. Conclusion: In patients with osteoporotic vertebral fractures, the fat infiltration rate may be an important predictor of conservative treatment. The prognosis of patients with a high-fat infiltration rate should be explained during patient education, and the patients must be monitored closely through short-term outpatient follow-up.

• Journal of the Korean earth science society
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• v.43 no.2
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• pp.239-252
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• 2022

Quality control methods for the first G-band vapor radiometer (GVR) mounted on a weather aircraft in Korea were developed using the GVR Precipitable Water Vapor (PWV). The aircraft attitude information (degree of pitch and roll) was applied to quality control to select the shortest vertical path of the GVR beam. In addition, quality control was applied to remove a GVR PWV ≥20 mm. It was found that the difference between the warm load average power and sky load average power converged to near 0 when the GVR PWV increased to 20 mm or higher. This could be due to the high brightness temperature of the substratus and mesoclouds, which was confirmed by the Communication, Ocean and Meteorological Satellite (COMS) data (cloud type, cloud top height, and cloud amount), cloud combination probe (CCP), and precipitation imaging probe (PIP). The GVR PWV before and after the application of quality control on a cloudy day was quantitatively compared with that of a local data assimilation and prediction system (LDAPS). The Root Mean Square Difference (RMSD) decreased from 2.9 to 1.8 mm and the RMSD with Korea Local Analysis and Precipitation System (KLAPS) decreased from 5.4 to 4.3 mm, showing improved accuracy. In addition, the quality control effectiveness of GVR PWV suggested in this study was verified through comparison with the COMS PWV by using the GVR PWV applied with quality control and the dropsonde PWV.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.27 no.2
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• pp.87-102
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• 2022

To clarify the spatial distribution pattern of macrozoobenthos in Korean coastal waters in the summer season and investigate the relationship between community structure and benthic environmental factors, field surveys on community structure and benthic environmental factors were conducted at 117 stations in August 2017. A total of 613 macrobenthic species were identified, with the mean density of 1,228 ind./m² and the mean biomass (wet weight) of 110.9 g WW/m². Rich biodiversity was found at stations near Wando and along the coast of the East Sea, and there is a trend that stations with greater biodiversity also showed higher mean density as well. The dominant species in all the coastal areas in Korea was Heteromastus filiformis, which were found at most of the stations during the survey. The relatively deep areas in the East Sea were dominated by Magelona johnsoni and Maldane cristata, which were the third and ninth dominant species in the study areas, respectively. Pseudopolydora kempi and Rhynchospio sp. were observed only at the station located in the Nakdong River estuary. From the cluster analysis the stations could be clustered into three station groups with more similar faunal composition. Group A was located in the eastern coast, characterized with deep water depth and low levels of sand contents, while Group B was located in the southern coast, characterized by shallow depth of water and high content of mud and organic matter. Lastly, Group C was in the western coast, demonstrating low levels of mud content and organic matters. The biodiversity of macrobenthic species in the study area showed high positive correlation coefficients with benthic environmental factors such as sorting, clay, silt, and contents of organic matter in sediments, but negatively correlated with the sand contents. Major dominant species, Theora lata and Eriopisella sechellensis, both showed negative correlation coefficients with the sand contents, but a relatively high positive correlation with the levels of organic contents.It can be concluded that the spatial distribution patterns of macrobenthic organisms in Korean coastal waters are affected by depth, sediment type, and contents of organic matters.

• Korean Journal of Remote Sensing
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• v.38 no.5_1
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• pp.609-625
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• 2022

Validation of satellite data products is critical for subsequent analysis that is based on the data. Particularly, performance of ocean color products in turbid and shallow near-land ocean areas has been questioned for long time for its difficulty that stems from the complex optical environment with varying distribution of water constituents. Furthermore, validation with ship-based or station-based measurements has also exhibited clear limitation in its spatial scale that is not compatible with that of satellite data. This study firstly performed validation of major GOCI-II products such as remote sensing reflectance, chlorophyll-a concentration, suspended particulate matter, and colored dissolved organic matter, using the in-situ measurements collected from ship-based field campaign. Secondly, this study also presents preliminary analysis on the use of drone images for product validation. Multispectral images were acquired from a MicaSense RedEdge camera onboard a UAV to compensate for the significant scale difference between the ship-based measurements and the satellite data. Variation of water radiance in terms of camera altitude was analyzed for future application of drone images for validation. Validation conducted with a limited number of samples showed that GOCI-II remote sensing reflectance at 555 nm is overestimated more than 30%, and chlorophyll-a and colored dissolved organic matter products exhibited little correlation with in-situ measurements. Suspended particulate matter showed moderate correlation with in-situ measurements (R²~0.6), with approximately 20% uncertainty.

• Korean Journal of Environment and Ecology
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• v.36 no.4
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• pp.368-380
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• 2022

Biomonitoring of an invasive alien crayfish species, Procambarus clarkii (Girard, 1852), was performed from February to October 2021, along with environmental DNA analysis, at five locations including Wanju-gun, Hampyeong-gun, Naju-si, Gurye-gun, and Cheongju-si. For the investigation, an umbrella-shaped trap for adults and a hand net for young crayfish were used, and 8 to 10L of freshwater was collected for eDNA analysis. The current status and past distributional records of crayfish in Korea were analyzed along with benthic macroinvertebrates at each survey site. As a result of the investigation, a total of 122 individuals were identified, and Hampyeong-gun recorded the largest number of populations with 59 individuals (48.36%) and the highest environmental DNA (eDNA). The frequency of appearance of P. clarkii was highest in May. The ratio of females to males was 21:5, and the body size was 72.2±21.1mm for female, 80.5±15.6mm for male, and 25.3±9.8mm for young crayfish. P. clarkii introduced into Korea is mainly spreading in the southwest region and it has not been observed in Seoul where there had been a record of appearance in the past. No external symbiosis (Branchiobdellida) of P. clarkii has been identified, and P. clarkii that has appeared in Korea was presumed to be imported from Japan. There are more than eight kinds of exotic crayfish distributed in Korea, and among them, the marbled crayfish (P. virginalis) was identified as a harmful species to the ecosystem of Korea by the Ministry of Environment in 2021. The identified species of benthic macroinvertebrates inhabiting the survey area where P. clarkii has appeared were 69 belonging to 39 families, 15 orders, five classes, and three phyla. Among them, Odonata were the most abundant (16 spp.; 24.62%), followed by Coleoptera (11 spp.; 16.92%) and Hemiptera (11 spp.; 16.92%). In the survey area, one Korean endemic species (Rhoenanthus coreanus), one species (Helophorus auriculatus) classified as Near Threatened (NT) on the Korean Red List, and six species of Crustaceans appeared. In the functional feeding group, the predators appeared predominantly while in habitat oriented group, the climbers appeared to be abundant. It was confirmed that P. clarkii in the survey area prefers an area rich in aquatic vegetation with waterside vegetation, and has high resistance to turbid water quality. The omnivore invader P. clarkii is expected to maintain a competitive relationship with carnivorous benthic macroinvertebrates that are predominant in the same species, and is expected to continue to generate ecosystem disturbance along the food chains.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.313-331
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• 2022

Natural or native abiotic molecular hydrogen (H₂) is a major component in natural gas, however yet its importance in the global energy sector's usage as clean and renewable energy is underestimated. Here we review the occurrence and geological settings of native hydrogen to demonstrate the much widesprease H₂ occurrence in nature by comparison with previous estimations. Three main types of source rocks have been identified: (1) ultramafic rocks; (2) cratons comprising iron (Fe²⁺)-rich rocks; and (3) uranium-rich rocks. The rocks are closely associated with Precambrian crystalline basement and serpentinized ultramafic rocks from ophiolite and peridotite either at mid-ocean ridges or within continental margin(Zgonnik, 2020). Inorganic geological processes producing H₂ in the source rocks include (a) the reduction of water during the oxidation of Fe²⁺ in minerals (e.g., olivine), (b) water splitting due to radioactive decay, (c) degassing of magma at low pressure, and (d) the reaction of water with surface radicals during mechanical breaking (e.g., fault) of silicate rocks. Native hydrogen are found as a free gas (51%), fluid inclusions in various rock types (29%), and dissolved gas in underground water (20%) (Zgonnik, 2020). Although research on H₂ has not yet been carried out in Korea, the potential H₂ reservoirs in the Gyeongsang Basin are highly probable based on geological and geochemical characteristics including occurrence of ultramafic rocks, inter-bedded basaltic layers and iron-copper deposits within thick sedimentary basin and igneous activities at an active continental margin during the Permian-Paleogene. The native hydrogen is expected to be clean and renewable energy source in the near future. Therefore it is clear that the origin and exploration of the native hydrogen, not yet been revealed by an integrated studies of rock-fluid interaction studies, are a field of special interest, regardless of the presence of economic native hydrogen reservoirs in Korea.

• Korean Journal of Remote Sensing
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• v.38 no.5_3
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• pp.939-951
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• 2022

The most important factor in designing autonomous driving systems is to recognize the exact location of the vehicle within the surrounding environment. To date, various sensors and navigation systems have been used for autonomous driving systems; however, all have limitations. Therefore, the need for high-definition (HD) maps that provide high-precision infrastructure information for safe and convenient autonomous driving is increasing. HD maps are drawn using three-dimensional point cloud data acquired through a mobile mapping system (MMS). However, this process requires manual work due to the large numbers of points and drawing layers, increasing the cost and effort associated with HD mapping. The objective of this study was to improve the efficiency of HD mapping by segmenting semantic information in an MMS point cloud into six classes: roads, curbs, sidewalks, medians, lanes, and other elements. Segmentation was performed using various machine learning techniques including random forest (RF), support vector machine (SVM), k-nearest neighbor (KNN), and gradient-boosting machine (GBM), and 11 variables including geometry, color, intensity, and other road design features. MMS point cloud data for a 130-m section of a five-lane road near Minam Station in Busan, were used to evaluate the segmentation models; the average F1 scores of the models were 95.43% for RF, 92.1% for SVM, 91.05% for GBM, and 82.63% for KNN. The RF model showed the best segmentation performance, with F1 scores of 99.3%, 95.5%, 94.5%, 93.5%, and 90.1% for roads, sidewalks, curbs, medians, and lanes, respectively. The variable importance results of the RF model showed high mean decrease accuracy and mean decrease gini for XY dist. and Z dist. variables related to road design, respectively. Thus, variables related to road design contributed significantly to the segmentation of semantic information. The results of this study demonstrate the applicability of segmentation of MMS point cloud data based on machine learning, and will help to reduce the cost and effort associated with HD mapping.

• Journal of Popular Narrative
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• v.26 no.1
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• pp.243-277
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• 2020

This paper examines a social and cultural history of horror films through the keyword "technology", focusing on The Spark of Fear: Technology, Society and the Horror Film (2015) written by Brian N. Duchaney. Science fiction film is closely connected with technology in film genres. On the other hand, horror films have been explained in terms of nature/supernatural. In this regard, The Spark of Fear, which accounts for horror film history as (re)actions to the development of technology, is remarkable. Early horror films which were produced under the influence of gothic novels reflected the fear of technology that had been caused by industrial capitalism. For example, in the film Frankenstein (1931), an angry crowd of people lynch the "monster", the creature of technology. This is the action which is aroused by the fear of technology. Furthermore, this mob behavior is suggestive of an uprising of people who have been alienated by industrial capitalism during the Great Depression. In science fiction horror films, which appeared in the post-war boom, the "other" that manifests as aliens is the entity that destroys the value of prosperity during post-war America. While this prosperity is closely related to the life of the middle class in accordance with the suburbanization, the people live conformist lives under the mantle of technologies such as the TV, refrigerator, etc. In the age of the Vietnam War, horror films demonize children, the counter-culture generation against a backdrop of the house that is the place of isolation and confinement. In this place, horror arises from the absolute absence of technology. While media such as videos, internet, and smartphones have reinforced interconnectedness with the outside world since the 1980s, it became another outside influence that we cannot control. "Found-footage" and "torture porn" which were rife in post-9/11 horror films show that the technologies of voyeurism/surveillance and exposure/exhibitionism are near to saturation. In this way, The Spark of Fear provides an opportune insight into the present day in which the expectation and fear of the progress of technology are increasingly becoming inseparable from our daily lives.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.4
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• pp.11-18
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• 2021

A novel microwave dielectric composite material for ultra-low temperature co-fired ceramics (ULTCC) with (1-x)BaWO₄-xBaV₂O₆ (x=0.54~0.85) composition was prepared by firing a mixture of BaWO₄ and BaV₂O₆. Shrinkage tests showed that the ceramic composite begins to densify at a temperature as low as 550℃ and can be sintered at 650℃ with 98% of relative density under the influence of BaV₂O₆. X-ray diffraction analysis showed that BaWO₄ and BaV₂O₆ coexisted and no secondary phase was detected in the sintered bodies, implying good chemical compatibility between the two phases. Near-zero temperature coefficients of the resonant frequency (𝛕_f) could be achieved by controlling the relative content of the two phases, due to their positive and negative 𝛕_f values, respectively. With increasing BaV₂O₆ (x from 0.53 to 0.85), the 𝛕_f value of the composites increased from -7.54 to 14.49 ppm/℃, ε_r increased from 10.08 to 11.17 and the quality factor (Q×f value) decreased from 47,661 to 37,131 GHz. The best microwave dielectric properties were obtained for x=0.6 samples with ε_r=10.4, Q×f=44,090 GHz, and 𝛕_f=-2.38 ppm/℃. Chemical compatibility experiments showed the developed composites are compatible with aluminum electrode during co-firing process.