• Korean Journal of Remote Sensing
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• v.23 no.2
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• pp.145-152
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• 2007

The polarimetric backscattering coefficients of a wet-land rice field which is an experimental plot belong to National Institute of Agricultural Science and Technology in Suwon are measured using ground-based polarimetric scatterometers at 1.8 and 5.3 GHz throughout a growth year from transplanting period to harvest period (May to October in 2006). The polarimetric scatterometers consist of a vector network analyzer with time-gating function and polarimetric antenna set, and are well calibrated to get VV-, HV-, VH-, HH-polarized backscattering coefficients from the measurements, based on single target calibration technique using a trihedral corner reflector. The polarimetric backscattering coefficients are measured at $30^{\circ},\;40^{\circ},\;50^{\circ}\;and\;60^{\circ}$ with 30 independent samples for each incidence angle at each frequency. In the measurement periods the ground truth data including fresh and dry biomass, plant height, stem density, leaf area, specific leaf area, and moisture contents are also collected for each measurement. The temporal variations of the measured backscattering coefficients as well as the measured plant height, LAI (leaf area index) and biomass are analyzed. Then, the measured polarimetric backscattering coefficients are compared with the rice growth parameters. The measured plant height increases monotonically while the measured LAI increases only till the ripening period and decreases after the ripening period. The measured backscattering coefficientsare fitted with polynomial expressions as functions of growth age, plant LAI and plant height for each polarization, frequency, and incidence angle. As the incidence angle is bigger, correlations of L band signature to the rice growth was higher than that of C band signatures. It is found that the HH-polarized backscattering coefficients are more sensitive than the VV-polarized backscattering coefficients to growth age and other input parameters. It is necessary to divide the data according to the growth period which shows the qualitative changes of growth such as panicale initiation, flowering or heading to derive functions to estimate rice growth.

• Korean Journal of Remote Sensing
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• v.25 no.1
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• pp.31-44
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• 2009

The objective of this study was to measure backscattering coefficients of paddy rice using a L-, C-, and X-band scatterometer system with full polarization and various angles during the rice growth period and to relate backscattering coefficients to rice growth parameters. Radar backscattering measurements of paddy rice field using multifrequency (L, C, and X) and full polarization were conducted at an experimental field located in National Academy of Agricultural Science (NAAS), Suwon, Korea. The scatterometer system consists of dual-polarimetric square horn antennas, HP8720D vector network analyzer ($20\;MHz{\sim}20\;GHz$), RF cables, and a personal computer that controls frequency, polarization and data storage. The backscattering coefficients were calculated by applying radar equation for the measured at incidence angles between $20^{\circ}$ and $60^{\circ}$ with $5^{\circ}$ interval for four polarization (HH, VV, HV, VH), respectively. We measured the temporal variations of backscattering coefficients of the rice crop at L-, C-, X-band during a rice growth period. In three bands, VV-polarized backscattering coefficients were higher than hh-polarized backscattering coefficients during rooting stage (mid-June) and HH-polarized backscattering coefficients were higher than VV-, HV/VH-polarized backscattering coefficients after panicle initiation stage (mid-July). Cross polarized backscattering coefficients in X-band increased towards the heading stage (mid-Aug) and thereafter saturated, again increased near the harvesting season. Backscattering coefficients of range at X-band were lower than that of L-, C-band. HH-, VV-polarized ${\sigma}^{\circ}$ steadily increased toward panicle initiation stage and thereafter decreased, and again increased near the harvesting season. We plotted the relationship between backscattering coefficients with L-, C-, X-band and rice growth parameters. Biomass was correlated with L-band hh-polarization at a large incident angle. LAI (Leaf Area Index) was highly correlated with C-band HH- and cross-polarizations. Grain weight was correlated with backscattering coefficients of X-band VV-polarization at a large incidence angle. X-band was sensitive to grain maturity during the post heading stage.

• Journal of Food Hygiene and Safety
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• v.34 no.5
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• pp.447-453
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• 2019

In this study, the contamination of 4 types of heavy metals (lead, cadmium, arsenic, and mercury) was monitored in 80 seaweeds and their processed products, and a food safety assessment was also carried out for these heavy metals. Lead, cadmium and arsenic were analyzed by ICP-OES and mercury was analyzed by mercury analyzer. The detection ranges of heavy metals were found as follows: Pb (N.D-0.802 mg/kg), Cd (N.D-0.759 mg/kg), As (0.134-17.296 mg/kg), and Hg (0.0005-0.0331 mg/kg). Pb and Hg showed no significant differences among seaweeds whereas Cd and As were significantly higher in the species hizikia fusiforme (P<0.05). Food safety assessment from seaweed intake was measured by PTWI (Provisional Tolerable Weekly Intake), PTMI (Provisional Tolerable Monthly Intake), and MADL (Maximum Allowable Daily Body Load) as set by JECFA (Joint FAO/WHO Expert Committee on Food Additives). Pb and Hg were 0.197%, 0.036% of PTWI respectively, while Cd was 1.877% of PTMI and As was 0.619% of MADL. Therefore, it was found that heavy metal levels of seaweed were low and was considered to be safe for consumption.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.401-409
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• 2021

This study aimed to estimate the photosynthetic capacity of tomato plants grown in a semi-closed greenhouse using temperature response models of plant photosynthesis by calculating the ribulose 1,5-bisphosphate carboxylase/oxygenase maximum carboxylation rate (V_cmax), maximum electron transport rate (J_max), thermal breakdown (high-temperature inhibition), and leaf respiration to predict the optimal conditions of the CO₂-controlled greenhouse, for maximizing the photosynthetic rate. Gas exchange measurements for the A-C_i curve response to CO₂ level with different light intensities {PAR (Photosynthetically Active Radiation) 200µmol·m^-2·s^-1 to 1500µmol·m^-2·s^-1} and leaf temperatures (20℃ to 35℃) were conducted with a portable infrared gas analyzer system. Arrhenius function, net CO₂ assimilation (A_n), thermal breakdown, and daylight leaf respiration (R_d) were also calculated using the modeling equation. Estimated J_max, A_n, Arrhenius function value, and thermal breakdown decreased in response to increased leaf temperature (> 30℃), and the optimum leaf temperature for the estimated J_max was 30℃. The CO₂ saturation point of the fifth leaf from the apical region was reached at 600ppm for 200 and 400µmol·m^-2·s^-1 of PAR, at 800ppm for 600 and 800µmol·m^-2·s^-1 of PAR, at 1000ppm for 1000µmol of PAR, and at 1500ppm for 1200 and 1500µmol·m^-2·s^-1 of PAR levels. The results suggest that the optimal conditions of CO₂ concentration can be determined, using the photosynthetic model equation, to improve the photosynthetic rates of fruit vegetables grown in greenhouses.

• The Korean Journal of Vision Science
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• v.20 no.4
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• pp.469-482
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• 2018

Purpose : We investigated the change of spherical and comma aberrations after wearing aspheric soft contact lens (ASCL) in young myopes. Methods : Fifty young myopes ($23.15{\pm}1.70years$, spherical equivalent: $-2.90{\pm}1.75D$) were recruited and refractive errors were corrected using ASCL (Biotrue, Bausch+Lomb, USA). High order aberrations were measured in the 4 mm pupil size using the wavefront analyze and pupil sizes were measured with a pupillometer at the modes of scotopic condition (light off) at 3.5 m in the 100 lx illuminance condition. Results : Spherical aberrations and coma aberration of the 20s myopes were $0.026{\pm}0.031{\mu}m$ and $0.078{\pm}0.039{\mu}m$ respectively, and $0.019{\pm}0.026{\mu}m$ and $0.082{\pm}0.038{\mu}m$ after ASCL wear that spherical aberration was decreased and coma aberration was increased. However, spherical aberration was decreased in the 68% of the subject have positive spherical aberration, and increased in the 11% of the subject have negative spherical aberration. Coma aberration was increased in the 53% of the subject, did not change in the 19% of the subjects, and decreased in the 28% of the subject. Spherical aberration was not different with the refractive errors in low and moderate myopies, however, coma aberrations was higher in the higher myopes. Conclusion : In a scotopic condition without accommodation stimuli, spherical aberration is decreased after wearing ASCL, however in the subject have negative spherical aberration spherical aberration could be increased, and which is thought to be the influence of contact lens design and pupil size.

• Journal of vocational education research
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• v.35 no.4
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• pp.131-153
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• 2016

The purpose of this study was to derive evaluator's role and capability for institution accreditation evaluation of NCS-based vocational competency development training. This study attempted to explore in various ways evaluator's minute roles using Delphi method, and to derive knowledge, skill, attitude and integrity needed to verify the validity. To the end, this study conducted the Delphi research for over three rounds by selecting education training professionals and review evaluation professions as professional panels. From the results, roles of evaluators were defined as the total eight items including operator, moderator-mediator, cooperator, analyzer, verifier, institution evaluator, institution consultant, and learner, and the derived capabilities with respect to each role were 25 items in total. The area of knowledge included four items of capabilities such as HRD knowledge, NCS knowledge, knowledge of vocational competency development training, and knowledge of training institution accreditation evaluation, and the area of skill comprised fourteen items of capabilities such as conflict management ability, interpersonal relation ability, word processing ability, problem-solving ability, analysis ability, pre-preparation ability, time management ability, decision making ability, information comprehension and utilization ability, comprehensive thinking ability, understanding ability of vocational competency development training institutions, communication ability, feedback ability, and core understanding ability. The area of attitude was summarized with the seven items in total including subjectivity and fairness, service mind, sense of calling, ethics, self-development, responsibility, and teamwork. The knowledge, skill and attitude derived from the results of this study may be utilized to design and provide education programs conducive to qualitative and systematic accreditation and assessment to evaluators equipped with essential prerequisites. It is finally expected that this study will be helpful for designing module education programs by ability and for managing evaluator's quality in order to perform pre-service education and in-service education according to evaluator's experience and role.

• Food Engineering Progress
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• v.15 no.1
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• pp.56-63
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• 2011

Durum wheat semolina was added into wet-milled rice flour in order to improve chewy texture, firm bite ("al dente"), and resistance to overcooking of the ordinary rice noodles. Wet noodles were prepared by mixing 0 (control), 5, 10, 15, and 20% (w/w) of semolina per semolina and rice flour mixtures. Vital gluten (4%, w/w) and salt (2%, w/w) were added to form the pliable strands of wet noodles and final moisture contents of the raw mixtures were equalized at 45%. Pasting properties of the suspended flour mixtures as measured by the Rapid Visco Analyser (RVA) showed slight increases (up to $1.2^{\circ}C)$ in pasting temperatures along with the considerable decreases in peak viscosities as semolina increased at over 15%. Reduced shear thinning and retrogradation of the starch solution that leads to hardening of the cooked noodles were indicated by lowered breakdown viscosities and gaps between finaland setback viscosities from the RVA viscogram as semolina increased at over 10%. Reduced water uptake and turbidity increases of the cooking water as caused by the soluble starches from the noodle were also noted as the content of semolina increased. More or less significant (p<0.05) decreases in colorimetric L (lightness) value of the raw- and cooked noodles were observed as semolina increased while a- (redness) and b (yellowness) values were rather increased at the same moment. Textural properties of the cooked noodles such as hardness, springiness, cohesiveness, gumminess, and chewiness from TPA tests were significantly (p<0.05) influenced by added semolina, even at 5%-levels or more. It can be concluded that addition of semolina into rice flour could provide easy handling of the wet noodles without distortion during transportation, integrity and firm bite of the cooked noodles, and less loss of starch to the cooking water in comparison with the ordinary rice noodle. It was finally suggested that optimum level of the semolina in the product was approximately 10% for the quality wet rice noodle products.

• Journal of Environmental Impact Assessment
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• v.28 no.2
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• pp.113-128
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• 2019

The concentration and coating thickness of black carbon (BC) were measured along with fine dust in the fall of 2018, at the Seoul Metropolitan Area Intensive Monitoring Station (SIMS). In fall, the concentration of $PM_{10}$ and $PM_{2.5}$ was $23{\pm}12.6{\mu}g/m^3$ and $12{\pm}5.8{\mu}g/m^3$, respectively, lower than that in other seasons. The BC level, measured using an Aethalometer, was $0.73{\pm}0.43{\mu}g/m^3$, while the levels of elemental carbon (EC) and refractory-BC (rBC), measured by semi-continuous carbon analyzer (SOCEC) and single particle soot photometer (SP2), were $0.34{\pm}0.18{\mu}g/m^3$ and $0.32{\pm}0.18{\mu}g/m^3$, respectively. As such, the concentration level differed according to the measurement method, but its time-series distribution and diurnal variation showed the same trends. The BC concentration at SIMS was primarily affected by automobiles with higher levels of BC during morning and evening commuting times due to increased traffic congestion. rBC, measured by SP2, had a peak concentration and coating thickness of 84 nm and 43 nm, respectively. Notably, the coating thickness had an inverse relationship with particle size.

• Journal of Food Hygiene and Safety
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• v.33 no.6
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• pp.453-459
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• 2018

This study was performed to investigate the contamination levels of heavy metals (such as lead, cadmium, arsenic and mercury) and aflatoxin (such as $B_1$, $B_2$, $G_1$ and $G_2$) in commercial herbs for food and medicine. The concentrations of the heavy metals were measured by the ICP-MS and a mercury analyzer. The aflatoxins were analyzed by a HPLC-florescence coupled with photochemical derivatization. The detection ranges of the lead, cadmium, arsenic and mercury were found to be 0.006~4.088 mg/kg, 0.002~2.150 mg/kg, ND~0.610 mg/kg and ND~0.0139 mg/kg respectively. Among the total samples, the 3 samples (2.6%) were not suitable for the specification of cadmium by the MFDS (Ministry of Food and Drug Safety). The 13 samples of the total 117 samples were aflatoxin positive (11.1%). The amount of aflatoxin $G_1$ was $0.7834{\mu}g/kg$ in the Puerariae Radix and aflatoxin $G_2$ were $0.3517{\mu}g/kg$, $0.4881{\mu}g/kg$ in two samples of the Glycyrrhizae Radix et Rhizoma, respectively. The aflatoxins $B_2$ and $G_1$ were simultaneously detected in the 10 Angelicae Gigantis Radix. The detection ranges of aflatoxins $B_2$ and $G_1$ were $0.2324{\sim}1.0358{\mu}g/kg$ and $0.7552{\sim}1.6545{\mu}g/kg$ respectively in Angelicae Gigantis Radix. The results of the current study suggest that continuous monitoring is needed for the proactive management of commercial herbs for food and medicine safety.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.3
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• pp.1-7
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• 2021

In this paper, by embedding a bare-die chip-type drive amplifier into the PCB composed of ABF and FR-4, it implements an embedded active device that can be applied in 28 GHz band modules. The ABF has a dielectric constant of 3.2 and a dielectric loss of 0.016. The FR-4 where the drive amplifier is embedded has a dielectric constant of 3.5 and a dielectric loss of 0.02. The proposed embedded module is processed into two structures, and S-parameter properties are confirmed with measurements. The two process structures are an embedding structure of face-up and an embedding structure of face-down. The fabricated module is measured on a designed test board using Taconic's TLY-5A(dielectric constant : 2.17, dielectric loss : 0.0002). The PCB which embedded into the face-down expected better gain performance due to shorter interconnection-line from the RF pad of the Bear-die chip to the pattern of formed layer. But it is verified that the ground at the bottom of the bear-die chip is grounded Through via, resulting in an oscillation. On the other hand, the face-up structure has a stable gain characteristic of more than 10 dB from 25 GHz to 30 GHz, with a gain of 12.32 dB at the center frequency of 28 GHz. The output characteristics of module embedded into the face-up structure are measured using signal generator and spectrum analyzer. When the input power (P_in) of the signal generator was applied from -10 dBm to 20 dBm, the gain compression point (P_1dB) of the embedded module was 20.38 dB. Ultimately, the bare-die chip used in this paper was verified through measurement that the oscillation is improved according to the grounding methods when embedding in a PCB. Thus, the module embedded into the face-up structure will be able to be properly used for communication modules in millimeter wave bands.