• Journal of Korean Society for Quality Management
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• v.51 no.1
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• pp.55-65
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• 2023

Purpose: The purpose of this study is to propose an optimization process to improve product yield in the process using process data. Recently, research for low-cost and high-efficiency production in the manufacturing process using machine learning or deep learning has continued. Therefore, this study derives major variables that affect product defects in the manufacturing process using eXplainable Artificial Intelligence(XAI) method. After that, the optimal range of the variables is presented to propose a methodology for improving product yield. Methods: This study is conducted using the injection molding machine AI dataset released on the Korea AI Manufacturing Platform(KAMP) organized by KAIST. Using the XAI-based SHAP method, major variables affecting product defects are extracted from each process data. XGBoost and LightGBM were used as learning algorithms, 5-6 variables are extracted as the main process variables for the injection process. Subsequently, the optimal control range of each process variable is presented using the ICE method. Finally, the product yield improvement methodology of this study is proposed through a validation process using Test Data. Results: The results of this study are as follows. In the injection process data, it was confirmed that XGBoost had an improvement defect rate of 0.21% and LightGBM had an improvement defect rate of 0.29%, which were improved by 0.79%p and 0.71%p, respectively, compared to the existing defect rate of 1.00%. Conclusion: This study is a case study. A research methodology was proposed in the injection process, and it was confirmed that the product yield was improved through verification.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.2
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• pp.177-184
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• 1991

Soybean cultivars for bean sprouting, and for cooking with rice are related closely with Korean dietary tradition, but their yields have been kept in low level. The yielding responses of Danyup, a cultivar for bean sprouting and Gumjung, a cultivar for cooking with rice were compared with Paldal as standard cultivar in planting density within 10 to 80 plants per ㎡. Yield of Paldal increased as planting density increased from 10 plants up to 80 plant/㎡. But, Danyup reached at threshold as planting density reached up to 40 plants/㎡. Gumjung did not have significant difference in yield within planting density. Danyup had the highest yield, 445 kg/l0a at 80 plants/㎡. The highest yield of Paldal was 406kg/10a at 40 plants /㎡ while Gumjung had 373kg/ l0a at 40 plants. The yield responses of cultivars were influenced by canopy structure and light utilization. Paldal had short and straight canopy with determinate growth habit responded well at the heavy density, and had 6.2 in critical LA!. But Gumjung, tall and dense canopy with indeterminate growth habit had limited utilization of light within canopy with 5.4 in critical LAI and high rate of lodging. Gumjung was concluded as a low yielding cultivar, since it did not have good response to increasing source size and sink number.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.2
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• pp.80-85
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• 2002

This study was conducted to investigate the effects of night illumination on the growth and yield of sesame(Sesamum indicum) and perilla(Perilla frutescens). Stem length and height of the first pod in sesame increased, whereas number of branch was reduced and flowering date and maturing date delayed as light intensity of night illumination increased. Number of capsules per plant, ripening ratio and seed yield of sesame were reduced as light intensity of night illumination increased. Yield reduction was greater in Ahnsankkae than in Sodunkkae. Number of nodes increased under night illumination in perilla. Two test cultivars showed reduction in number of branch at 6~10 Lx(22 ㎽ m$^{-2}$ ) intensity of night illumination, even though there was a variation between cultivars. Perilla was sensitive to night illumination far flowering and ripening. Flowering date was delayed by 21 to 28 days at 6~10 Lx intensity of night illumination. Number of flower clusters, number of seeds per flower cluster, and 1,000-seed weight in perilla were significantly reduced and seed yield was reduced by 89 to 98% at 6-10 Lx intensity of night illumination.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.E2
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• pp.89-98
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• 2006

Two tobacco cultivars (Nicotiana tabacum L.), Bel-B and Bel-W3, tolerant and sensitive to ozone, respectively, were grown in a greenhouse supplied with charcoal filtered air and exposed to 200 ppb ozone for 4 hr. Effects on chlorophyll fluorescence, net photosynthesis, and stomatal conductance are described. Quantum yield was calculated from chlorophyll fluorescence and the initial slope of the assimilation-light curve measured by the gas exchange method. Only the sensitive cultivar, Bel-W3, developed visual injury symptoms on up to 50% of the $5^{th}$ leaf. The maximum net photosynthetic rate of ozone-treated plants was reduced 40% compared to control plants immediately after ozone fumigation in the tolerant cultivar; however, photosynthesis recovered by 24 hr post fumigation and remained at the same level as control plants. On the other hand, ozone exposure reduced maximum net photosynthesis up to 50%, with no recovery, in the sensitive cultivar apparently causing permanent damage to the photosystem. Reductions in apparent quantum efficiency, calculated from the assimilation-light curve, differed between cultivars. Bel-B showed an immediate depression of 14% compared to controls, whereas, Bel-W3 showed a 27% decline. Electron transport rate (ETR), at saturating light intensity, decreased 58% and 80% immediately after ozone treatment in Bel-B and Bel-W3, respectively. Quantum yield decreased 28% and 36% in Bel-B and Bel-W3, respectively. It can be concluded that ozone caused a greater relative decrease in linear electron transport than maximum net photosynthesis, suggesting greater damage to PSII than the carbon reduction cycle.

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1727-1734
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• 2013

Synthesis and characterization of some novel symmetric bis-azospiropyrans are reported in this study. These bis-azospiropyrans are bifunctional chromophores with two spiropyrans linked by a bis-azo extended aromatic system that produce more color strength (large molar absorption coefficient in mero forms) due to appending two azospiropyran chromophores on one molecule. Comparing to the molar absorption coefficients of the conventional spiropyran chromophores (${\varepsilon}=0.31{\times}10^4\;M^{-1}{\cdot}cm^{-1}$) and mono-azospiropyran chromophores ($1.35{\times}10^4\;M^{-1}{\cdot}cm^{-1}$), the novel synthesized photochromes showed astonishingly increased molar absorption coefficients ($2.3-3.8{\times}10^4\;M^{-1}{\cdot}cm^{-1}$) at the same conditions. Such high molar absorption coefficients confers high sensitivity to light and more color intensity of mero form, that leads to improvement of their light sensitivity and better discrimination of spiro (OFF) form from mero (ON) ones in molecular switches. The structures were deduced from their MS, FT-IR, and $^1H$-NMR spectroscopic data and CHN analysis. All the synthesized photochemically bifunctional compounds revealed fluorescent emission in their colorless form which was faded out after exposing to UV light. Fluorescence quantum yield values of the mero forms were 0.25-0.81 and two high fluorescence quantum yield values (0.60 and 0.81) were found in these series.

• Journal of the Optical Society of Korea
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• v.20 no.2
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• pp.276-282
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• 2016

A 2 Gbit/s visible-light communication (VLC) scheme using time-frequency color-clustered (TFCC) multiple-input multiple-output (MIMO) based on blue, cyan, yellow, and red (BCYR) light-emitting diodes (LEDs) is presented. In the proposed scheme, BCYR LEDs are employed to form four different color clusters. Data transmission using the four color clusters is performed in MIMO, so that the scheme achieves a very high speed of data transmission. Moreover, the scheme employs the TFCC strategy to yield high performance in terms of bit error rate (BER). TFCC operates in such a way that the original data and the two delayed versions of the data are multiplied by orthogonal frequencies and then transmitted using a specific color of the BCYR LED. In the receiver, color filters are employed to detect the data transmitted from the desired cluster. Selection combining (SC) is also performed to yield a diversity effect within each color cluster, to further improve the performance. Performance evaluation demonstrates that the proposed TFCC MIMO VLC offers a data rate of 2 Gbit/s and a bit error rate of 4×10^-5, at an E_b/N_o value of merely 3 dB.

• ETRI Journal
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• v.27 no.2
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• pp.181-187
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• 2005

Alkoxy-substituted poly(spirobifluorene)s and their copolymers with a triphenylamine derivative have been synthesized by Ni(0)-mediated polymerization. The polymers were well soluble in common organic solvents. Pure blue-light emissions without the long wavelength emission of poly(fluorene)s have been observed in the fluorescence spectra of polymer thin films. The light emitting diodes with a device configuration of ITO/PEDT:PSS(30 nm)/polymer(60 nm)/LiF(1 nm)/Al(100 nm) have been fabricated. The electroluminescence spectra showed the blue emissions without the long wavelength emission as observed in the fluorescence spectra. The relatively poor electroluminescence quantum yield of the homopolymer (0.017% @ 20 $mA/cm^{2}$) with color coordinates of (0.16, 0.07) has been improved by the introduction of triphenylamine moiety, and the copolymer with derivative exhibited an electroluminescence quantum yield of 0.15 % at 20 $mA/cm^{2}$ with color coordinates of (0.16, 0.08). Moreover, the introduction of polar side chains to the spirobifluorene moiety enhanced the device performance and led to the quantum yields of 0.6 to 0.7 % at 20 $mA/cm^{2}$, although there was some expense of color purities.

• Journal of Plant Biology
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• v.39 no.4
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• pp.309-314
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• 1996

Developmental of photosynthetic pigments and changes in chlorophyll fluorescence of dark-grown rice seedlings were studied during greening. Light-illumination stimulated accumulations of total chlorophylls and carotenoids in leaves of etiolated seedlings, accompanied by a decrease in the ratio of chlorophyll a to chlorophyll b. When the composition of carotenoids was analyzed, violaxanthin level was shown to increase up to 24 h after the beginning of light illumination, followed by a subsequent decline. In contrast to this, zeaxanthin level increased consistently with progress of deetiolatin. The role of zeaxanthin is discussed in relation to chlorophyll fluorescence quenching. A study on chlorophyll fluorescence kinetics of the rice seedlings being deetiolated showed a time-dependent increase in Fv/Fm (yield of variable fluorescence/maximum yield of fluoresecnece) ratios, indicating that greening is responsible for the activation of photochemical reaction centers of the photosystem. When chlorophyll fluorescence quenching was examined, qNP (nonphotochemical quenching) and qE (energy-dependent quenching) exhibited a time-dependent decline with progress of greening. The presented results indicate that greening-induced development of the photosynthetic machinery is associated the conversion of the carotenoid violaxanthin to zeaxanthin, suggesting that zeaxanthin synthesized in the illuminated leaves may provide the protection from the damage when etiolated plants are exposed to light.

• Korean Journal of Breeding Science
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• v.42 no.3
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• pp.207-211
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• 2010

'Taedong Valley' is a high yielding and processing potato cultivar, which is a clonal selection resulting from a cross between 'W870' and 'A88431-1'. It is a medium maturating cultivar with medium plant height and light green foliage. 'Taedong Valley' has profuse flowering habit and light purple flowers. Tubers are smooth, round, and with yellow skin, light yellow flesh, medium eye depth. Tubers have medium dormancy and good keeping quality. 'Taedong Valley' has stable yield under wide range of climatic conditions. It is resistant to common scab and potato virus Y, but moderately susceptible to late blight. It is also resistant to most of the disorders, particularly dehiscence, hollow heart and internal brown spots. This cultivar has high level of tuber uniformity and capable of yielding 43.6 t/ha which is about 9.0% higher than the control potato cultivar 'Atlantic' under optimum agronomical practices.

• Journal of Microbiology and Biotechnology
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• v.31 no.3
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• pp.429-438
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• 2021

Bacterial cellulose (BC) is widely used in the food industry for products such as nata de coco. The mechanical properties of BC hydrogels, including stiffness and viscoelasticity, are determined by the hydrated fibril network. Generally, Komagataeibacter bacteria produce gluconic acids in a glucose medium, which may affect the pH, structure and mechanical properties of BC. In this work, the effect of pH buffer on the yields of Komagataeibacter hansenii strain ATCC 53582 was studied. The bacterium in a phosphate and phthalate buffer with low ionic strength produced a good BC yield (5.16 and 4.63 g/l respectively), but there was a substantial reduction in pH due to the accumulation of gluconic acid. However, the addition of gluconic acid enhanced the polymer density and mechanical properties of BC hydrogels. The effect was similar to that of the bacteria using glycerol in another carbon metabolism circuit, which provided good pH stability and a higher conversion rate of carbon. This study may broaden the understanding of how carbon sources affect BC biosynthesis.