• Journal of the Korean Applied Science and Technology
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• v.33 no.3
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• pp.560-567
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• 2016

Acid-activated clays (SUPER-DC, DC-A3, and P1) are used for the bleaching of cold-pressed rapeseed oil. In this study we tested the bleaching performance of cold-pressed rapeseed oil according to the different reaction time (20, 40, 60, 80 min) and temperature (40, 80, $120^{\circ}C$). Oil color (lightness, redness, yellowness), pigments (chlorophyll A and carotenoid content) and quality properties (fatty acid composition, tocopherols (${\alpha}$, ${\beta}$, ${\gamma}$, ${\delta}$), and plant sterols (${\beta}$-sitosterol, campesterol, stigmasterol) content) were analyzed. The results showed that bleaching of cold-pressed rapeseed oil with 2% acid-activated clays at $40^{\circ}C$ for 20 min, brightness (L) increased, but redness (a) and yellowness (b) decreased. Bleaching of cold-pressed rapeseed oil with 2% DC-SUPER at $40^{\circ}C$ removed chlorophyll A and carotenoids pigments significantly. In addition, about 50% of total tocopherol content in cold-pressed rapeseed oil was reduced by bleaching. Originally total tocopherol content was 46.62mg/100g in cold-pressed rapeseed oil. But after bleaching, total tocopherol content was 12.67mg/100g (20 min bleaching), 15.31mg/100g (40 min bleaching), and 13.56mg/100g (60 min bleaching). However plant sterols content in cold-pressed rapeseed oil remained unchanged by bleaching. Overall, acid-activated clays were useful for the bleaching of pigmented rapeseed oil.

• Journal of Life Science
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• v.18 no.8
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• pp.1066-1071
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• 2008

Schizandra fruit (Schizandra chinensis fructus) were dried by three processes, $50^{\circ}C$ (50HAD), $70^{\circ}C$ hot air (70HAD) and freeze drying process (FRD). Terpenoid were collected by SDE(Simultaneous Steam Distillation-Extraction) and followed by GC-MSD analysis. Also colour profile of each dried samples were measured by Hunter colorimeter. From fresh schizandra fruit, were detected 15 kinds of monoterpene, 28 kinds of sesquiterpene and 7 kinds of terpene alcohol. Myrcene(56.97 ${\mu}g/g$) and ${\gamma}$-terpinene(58.49 ${\mu}g/g$) were the major monoterpenes, ${\beta}$-elemene(120.16 ${\mu}g/g$), ${\alpha}$-bergamotene (103.45 ${\mu}g/g$), ${\gamma}$-selinene (75.97 ${\mu}g/g$), ${\beta}$-cubebene(66.69 ${\mu}g/g$), aristolene (51.25 ${\mu}g/g$) and ${\alpha}$-ylangene(28.06 ${\mu}g/g$) were the sesquiterpenes, and T-muurolol (96.45 ${\mu}g/g$) and terpinen-4-ol(46.02 ${\mu}g/g$) were the terpene alcohols. The dried samples lost more than half of terpenoid content of fresh schizandra fruit during early stage of drying process, and then the level of terpenoid content was not significantly changed. The content of sesquiterpenes appeared to increase until 6 day of FRD. The amount of residual terpene alcohols contained in schizandra fruit dried by FRD was more than those remained after drying by other processes, and schizandra fruit dried by 70HAD exhibited the least residual terpene alcohols. Brightness parameter $L^{\ast}$ decreased with the rise in the level of drying temperature, to which redness parameter $a^{\ast}$ and yellowness $b^{\ast}$ appeared to be similar.

• Korean Journal of Food Science and Technology
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• v.30 no.2
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• pp.333-340
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• 1998

The research was investigated to determine the effect of irradiation or blanching either alone or in combination on the shelf-life of juices of Spuriopinella bracycarpar during storages. The juices was made from fresh or blanced Spuriopinella bracycarpar and gamma irradiated at the doses (0.5 kGy to 5 kGy). Microbial growth, color change, vitamin C, and sensory evaluation were evaluated during storage at 4 and $25^{\circ}C$. Blanched juices had little effect on the inhibition of microbial growth compared to that of fresh juices. However, significant reduction of microbial counts was observed in the 0.5 kGy irradiation of both juices and inhibition efficiency was greatly increased when irradiated juices was stored at $4^{\circ}C$ rather than at room temperature. Fresh juices without irradiation were little different from the irradiated fresh juices until 20d storage on color change because the juices was rapidly browned immediately after getting the juices from extractor, but blanched juices showed more bright and clear color than that of fresh juices. However, irradiated blanched juices showed greatly reduced the L, a, and b value compared to the non-irradiated blanched juices during storage. The loss of vitamin C from non-irradiated fresh juices was increased during storage and the irradiated fresh juices had little effect on the vitamin C change compared to the non-irradiated fresh juices. However, blanched juices showed less reduction of vitamin C than fresh juices and the irradiated blanched juices had little difference on the vitamin C change compared to the non-irradiated blanched juices, and both treatment showed less vitamin C loss at $4^{\circ}C$ storage. Fresh juces showed more strong grass flavor and biterness than blanched juices and irradiated fresh juices showed little difference on brightness, grass flavor, bitterness, freshness and acceptability, but irradiated blanched juices had better sensory evaluation on grass flavor, bitterness, freshness, and acceptability than non-irradiated branched juices.

• Korean Journal of Remote Sensing
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• v.30 no.1
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• pp.83-107
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• 2014

This study presents spatial characteristics of cloud using satellite image in the extreme heavy snowfall of the Yeongdong region. 3 extreme heavy snowfall events in the Yeongdong region during the recent 12 years (2001 ~ 2012) are selected for which the fresh snow cover exceed 50 cm/day. Spatial characteristics (minimum brightness temperature; Tmin, cloud size, center of cloud-cell) of cloud are analyzed by tracking main cloud-cell related with these events. These characteristics are compared with radar precipitation in the Yeongdong region to investigate relationship between cloud and precipitation. The results are summarized as follows, selected extreme heavy snowfall events are associated with the isolated, well-developed, and small-scale convective cloud which is developing over the Yeongdong region or moving from over East Korea Bay to the Yeongdong region. During the period of main precipitation, cloud-cell Tmin is low ($-40{\sim}-50^{\circ}C$) and cloud area is small (17,000 ~ 40,000 $km^2$). Precipitation area (${\geq}$ 0.5 mm/hr) from radar also shows small and isolated shape (4,000 ~ 8,000 $km^2$). The locations of the cloud and precipitation are similar, but in there centers are located closely to the coast of the Yeongdong region. In all events the extreme heavy snowfall occur in the period a developed cloud-cell was moving into the coastal waters of the Yeongdong. However, it was found that developing stage of cloud and precipitation are not well matched each other in one of 3 events. Water vapor image shows that cloud-cell is developed on the northern edge of the dry(dark) region. Therefore, at the result analyzed from cloud and precipitation, selected extreme heavy snowfall events are associated with small-scale secondary cyclone or vortex, not explosive polar low. Detection and tracking small-scale cloud-cell in the real-time forecasting of the Yeongdong extreme heavy snowfall is important.

• Korean Journal of Remote Sensing
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• v.28 no.1
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• pp.69-77
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• 2012

Surface insolation is one of the major indicators for climate research over the Earth system. For the climate research, long-term data and wide range of spatial coverage from the data observed by two or more of satellites of the same orbit are needed. It is important to improve the continuity and consistency of the derived products, such as surface insolation, from different satellites. In this study, surface insolations based on Geostationary Operational Environmental Satellite (GOES-9) and Multi-functional Transport Satellites (MTSAT-1R) were compared during overlap period using physical model of insolation to find ways to improve the consistency and continuity between two satellites through comparison of each channel data and ground observation data. The thermal infrared brightness temperature of two satellites show a relatively good agreement between two satellites : rootmean square error (RMSE)=5.595 Kelvin; Bias=2.065 Kelvin. Whereas, visible channels shown a quite different values, but it distributed similar tendency. And the surface insolations from two satellites are different from the ground observation data. To improve the quality of retrieved insolations, we have reproduced surface insolation of each satellite through adjustment of the Cloud Factor, and the Cloud Factor for GOES-9 satellite is modified based on the analysis result of difference channel data. As a result, the insolations estimated from GOES-9 for cloudy conditions show good agreement with MTSAT-1R and ground observation : RMSE=$83.439W\;m^{-2}$ Bias=$27.296W\;m^{-2}$. The result improved accuracy confirms that the modification of Cloud Factor for GOES-9 can improve the continuity and consistency of the insolations derived from two or more satellites.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.4
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• pp.65-69
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• 2009

Purpose: Recently incidence of VDT syndrome has gradually increased as extensive use of computers. VDT syndrome reported by VDT workers include musculoskeletal disorder, neuropsychiatric disoders and eye symptoms such as eye strain, tired eyes, irritation and blurred vision. The environmental factors of VDT syndrome include electromagnetic waves, size, brightness and lighting of computer screen, height of a monitor and a worktable, working hours, kind of task, distance between screen and workers, indoor humidity and temperature, indoor air contamination and ventilation. In this study, we investigated the environmental factors related to body symptoms and health effects included in VDT syndrome. Methods: Study subjects were total 120 persons (54 male, 66 female) with age from 19 to 28. We surveyed the body symptoms and physical discomfort when doing an activity in a short distance such as reading book or paper, computer work. The questionnaire included main body symptoms, self-consciousness symptoms of eye, satisfaction of working environment, pain of the wrist when using keyboard and mouse. Results: Most of people (70%) felt physical pain from long time work of computer, paper, electrical apparatus. They mainly complained pain of neck and low back (57.1%), eye (45.2%) and head (31%). With the environmental factors, 78.3% of the subjects complaint pain of eye from inappropriate illumination. Most of the symptoms included 'eye fatigue'(38.3%), 'dryness of eye'(31.9%) and 'blurred vision'(23.7%). Subjects in this study complained discomfort of their chairs and most of them experienced pain in the wrist when using keyboard or mouse. Conclusions: When people use electrical apparatus or work with paper, people would get their eye fatigue and feeling of physical fatigue because of not harmonizing various environmental factors such as light, space, posture, worktable with theirselves. Therefore, workers should develop preventive method such as self-control of adequate break time to avoid fatigue while VDT work. Work environment should be changed to ergonomic design for optimal visual environment to prevent musculoskeletal disorder through constant research.

• Korean Chemical Engineering Research
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• v.51 no.6
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• pp.766-773
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• 2013

A transparent film was fabricated based on bacterial cellulose (BC), BC has excellent physical strength and stability at high temperature and it is an environmental friendly flexible material. In order to improve the conductivity, silver nanowire (AgNW) and/or graphene were introduced to the BC membrane. The aspect ratio of the AgNW synthesized in this study was 214, with a length of $15{\mu}m$ and width of 70 nm. The higher aspect ratio improved the conductivity by reducing the contact resistance. The thermal and electrical properties of 7 types of films prepared were investigated. Each film was fabricated with rectangular shape ($2mm{\times}2mm{\times}50{\mu}m$). The films were scored with a net shape by a knife, and filled with AgNW and graphene to bestow conductivity. The film filled with AgNW showed favorable electrical characteristics with a thickness of $350{\mu}m$, electron concentration of $1.53{\times}10^{19}$, electron mobility of $6.63{\times}10^5$, and resistivity of 0.28. The film filled with graphene had a thickness of $360{\mu}m$, electron concentration of $7.74{\times}10^{17}$, electron mobility of 0.17, and resistivity of 4.78. The transmittances at 550 nm were 98.1% and 80.9%, respectively. All the films were able to light LEDs bulbs although their brightness differed. A thermal stability test of the BC and PET films at $150{\pm}5^{\circ}C$ showed that the BC film was more stable, whereas the PET film was quickly banded. From these results, it was confirmed that there it is possible to fabricate new transparent conductivity films based on BC.

• 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.

• Korean Journal of Remote Sensing
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• v.39 no.6_1
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• pp.1283-1297
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• 2023

Mid-wave infrared (MWIR) imagery, due to its ability to capture the temperature of land cover and objects, serves as a crucial data source in various fields including environmental monitoring and defense. The KOMPSAT-3A satellite acquires MWIR imagery with high spatial resolution compared to other satellites. However, the limited spatial resolution of MWIR imagery, in comparison to electro-optical (EO) imagery, constrains the optimal utilization of the KOMPSAT-3A data. This study aims to create a highly visible MWIR fusion image by leveraging the edge information from the KOMPSAT-3A panchromatic (PAN) image. Preprocessing is implemented to mitigate the relative geometric errors between the PAN and MWIR images. Subsequently, we employ a pre-trained pixel difference network (PiDiNet), a deep learning-based edge information extraction technique, to extract the boundaries of objects from the preprocessed PAN images. The MWIR fusion imagery is then generated by emphasizing the brightness value corresponding to the edge information of the PAN image. To evaluate the proposed method, the MWIR fusion images were generated in three different sites. As a result, the boundaries of terrain and objects in the MWIR fusion images were emphasized to provide detailed thermal information of the interest area. Especially, the MWIR fusion image provided the thermal information of objects such as airplanes and ships which are hard to detect in the original MWIR images. This study demonstrated that the proposed method could generate a single image that combines visible details from an EO image and thermal information from an MWIR image, which contributes to increasing the usage of MWIR imagery.

• Korean Journal of Remote Sensing
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• v.39 no.5_3
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• pp.979-995
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• 2023

As wildfires are difficult to predict, real-time monitoring is crucial for a timely response. Geostationary satellite images are very useful for active fire detection because they can monitor a vast area with high temporal resolution (e.g., 2 min). Existing satellite-based active fire detection algorithms detect thermal outliers using threshold values based on the statistical analysis of brightness temperature. However, the difficulty in establishing suitable thresholds for such threshold-based methods hinders their ability to detect fires with low intensity and achieve generalized performance. In light of these challenges, machine learning has emerged as a potential-solution. Until now, relatively simple techniques such as random forest, Vanilla convolutional neural network (CNN), and U-net have been applied for active fire detection. Therefore, this study proposed an active fire detection algorithm using state-of-the-art (SOTA) deep learning techniques using data from the Advanced Himawari Imager and evaluated it over East Asia and Australia. The SOTA model was developed by applying EfficientNet and lion optimizer, and the results were compared with the model using the Vanilla CNN structure. EfficientNet outperformed CNN with F1-scores of 0.88 and 0.83 in East Asia and Australia, respectively. The performance was better after using weighted loss, equal sampling, and image augmentation techniques to fix data imbalance issues compared to before the techniques were used, resulting in F1-scores of 0.92 in East Asia and 0.84 in Australia. It is anticipated that timely responses facilitated by the SOTA deep learning-based approach for active fire detection will effectively mitigate the damage caused by wildfires.