• Journal of Ginseng Research
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• v.12 no.1
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• pp.11-29
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• 1988

This study was conducted to investigate the effect of light intensity and temperature on the photosynthesis and respiration of ginseng plant. Highly significant, second degree curvilinear regressions were recognized among the photosynthesis of ginseng leaves, light intensity and temperature. And an interaction between the effects of light intensity and temperature on the photosynthesis of ginseng leaves was found to be highly significant. The increasing rate of photosynthesis with the increase of light intensity was markedly decreased with increasing temperature. The light compensation point of ginseng leaves was significantly varied with temperature, and the average point was approximately 600 lux. The light saturation point of Korean ginseng was 11,000 lux at $15^{\circ}C$ and $20^{\circ}C$ and around 9,500 lux at above $25^{\circ}C$. The decreasing rate of photosynthesis with the increase of temperature significantly increased with increasing light intensity. The optimum temperature for the photosynthesis of ginseng leaves was about 15 to $22^{\circ}C$ and markedly decreased with increasing light intensity. The highest photosynthesis occurred in ginseng leaves grown with the shade of 15% transmittance. The respiration of ginseng leaves increased with the shade of 5% and/or 30% transmittance. High temperature stimulated the respiration of ginseng leaves. Percent respiration to photosynthesis of ginseng leaves grown with the shade was increased at high temperature and decreased with increasing light Intensity. It was also increased with increasing transmittance. The maximum $CO_2$ absorption of ginseng leaves grown with the shade of 5Ps and ISVS transmittance accurred at 9 o'clock a.m., whereas that of 20% transmittance occurred at 7-9 o'clock a.m. The duration of $CO_2$ absorption was distinctively long with the shade of high transmittance. The $CO_2$ compensation point in the photosynthesis of ginseng leaves was 130 ppm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.6
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• pp.1231-1243
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• 1997

Digital satellite communication channels have nonlinearities with memory due to saturation characteristics of traveling wave tube amplifier in the satellite and transmitter/receiver linear filters. In this paper, we propose a network structure and a learning algorithm for complex pi-sigma network (CPSK) and exploit CPSN in the problem of equalization of nonlinear satellite channels. The proposed CPSN is a complex-valued extension of real-valued pi-sigma network that is a higher-order feedforward network with fast learning while greatly reducing network complexity by utilizing efficient form of polynomials for many input variables. The performance of the proposed CPSN is demonstrated by computer simulations on the equalization of complex-valued QPSK input symbols distorted by a nonlinear channel modeled as a Volterra series and additive noise. The results indicate that the CPSN shows good equalization performance, fast convergence, and less computations as compared to conventional higher-order models such as Volterra filters.

• Journal of Environmental Science International
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• v.22 no.12
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• pp.1571-1577
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• 2013

The effects of irradiance on the growth of toxic dinoflagellates Alexandrium tamarense (Masan Bay strain) and Alexandrium catenella (Jinhae Bay strain) were investigated in the laboratory. At $15^{\circ}C$ and 30 psu for A. tamarense and $25^{\circ}C$ and 30 psu for A. catenella, the irradiance-growth curve showed the maximum growth rate (${\mu}_{max}$) of 0.31 $day^{-1}$ with half-saturation photon flux density (PFD) ($K_I$) of 44.53 ${\mu}molm^{-2}s^{-1}$, and a compensation PFD ($I_c$) was 20.67 ${\mu}molm^{-2}s^{-1}$ for A. tamarense, and ${\mu}_{max}$ of 0.38 $day^{-1}$ with $K_I$ of 59.53 ${\mu}molm^{-2}s^{-1}$, and $I_c$ was 40.80 ${\mu}molm^{-2}s^{-1}$ for A. catenella. The $I_c$ equated to a depth of 8~9 m from March to June for A. tamarense and 6~7 m from March to June for A. catenella. These responses suggested that irradiance at the depth near the middle layer in Masan Bay would provide favorable conditions for two species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.6
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• pp.487-494
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• 2006

The effects of water temperature, salinity and irradiance on the growth of harmful algae Chattonella marina isolated from Gamak Bay in South Sea, Korea were investigated. C. marina was able to grow in temperatures of $15-30^{\circ}C$ and salinities of 10-35 psu. Maximum specific growth rate (0.64/day) was observed with combination of $25^{\circ}C$ and 25 psu. Optimal growth (${\ge}70%$ of maximum specific growth rate) was obtained with all salinities of the above $20^{\circ}C$. This result indicated that C. marina is a stenothermal of the high water temperature and euryhaline organism. C. marina was did not grow at irradiance ${\le} 10{\mu}mol$ photons/($m^2\;s$). Photoinhibition did not occur at $300{\mu}mol$ photons/($m^2\;s$), which was the maximum irradiance used in this study. The irradiance-growth curve was described as ${\mu}=0.78(I-11.4)/(I+34.1)$ at $25^{\circ}C$ and 25 psu. The half-saturation photon flux density (PFD) ($K_s$) was $56.9{\mu}mol$ photons/($m^2\;s$) and compensation PFD ($I_c$) was $11.4{\mu}mol$ photons/($m^2\;s$). The result of the present study indicate that C. marina has advantage physiological characteristic to the interspecific competition at the embayment and costal areas of South and West Sea, Korea in summer.

• ALGAE
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• v.21 no.3
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• pp.311-316
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• 2006

The effects of light quality and irradiance on the growth of Cochlodinium polykrikoides were investigated in the laboratory. At 25°C and 30 psu the irradiance-growth curve was described as μ = 0.34 (I-9.76)/(I+12.5), (r=0.98). This suggests half-saturation photon flux density (PFD) (Ks) of 32.0 μmol photons m–2 s–1, and a compensation PFD (Ic) of 9.76 μmol photons m–2 s–1. Because the Ic equates to a depth of ca. 15.4 m, these responses suggest that irradiance at the depth around and below the thermocline in Yeosuhae Bay would provide favorable conditions for C. polykrikoides. Photoinhibition did not occur at 300 μmol photons m–2 s–1, which was the maximum irradiance used in this study. Blue (450 nm), yellow (590 nm) and red (650 nm) light had different effects on the growth of C. polykrikoides: it grew well under blue light, but not under yellow light. This implies that C. polykrikoides is more likely to cause an outbreak of red tide in the open sea where blue-green wavelengths predominate, rather than in enclosed water bodies where suspended particles absorb most of the blue wavelengths, and yellow-orange wavelengths predominate.

• Journal of Broadcast Engineering
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• v.21 no.5
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• pp.770-781
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• 2016

As a result of reducing color information and edge information, object distinction in haze image occurs with difficulty. One of the famous defogging algorithm is haze removal by using 'Dark Channel Prior(DCP)', which is used to predict for transmission rate using color information of an image and eliminates haze from the image. But, In case that haze rate is estimated under color information, there is a miscalculated issue which is posed by haze rate and transmission in area with high brightness such as a white object or a light source. In this paper, We deal with a miscalculated issue by correcting from around haze rate, after application of color normalization used by main white part of image haze. Moreover, We calculation improved transmission based on the result of improved haze rate estimation. And then haze image quality is developed through refining transmission.

• Journal of Korean Academy of Nursing
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• v.52 no.4
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• pp.391-406
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• 2022

Purpose: The purpose of this study was to provide foundational knowledge on nursing tasks performed on patients with COVID-19 in a nationally-designated inpatient treatment unit. Methods: This study employs both quantitative and qualitative approaches. The quantitative method investigated the content and frequency of nursing tasks for 460 patients (age ≥ 18 y, 57.4% men) from January 20, 2020, to September 30, 2021, by analyzing hospital information system records. Qualitative data were collected via focus group interviews. The study involved interviews with three focus groups comprising 18 nurses overall to assess their experiences and perspectives on nursing care during the pandemic from February 3, 2022, to February 15, 2022. The data were examined with thematic analysis. Results: Overall, 49 different areas of nursing tasks (n = 130,687) were identified based on the Korean Patient Classification System for nurses during the study period. Among the performed tasks, monitoring of oxygen saturation and measuring of vital signs were considered high-priority. From the focus group interview, three main themes and eleven sub-themes were generated. The three main themes are "Experiencing eventfulness in isolated settings," "All-around player," and "Reflections for solutions." Conclusion: During the COVID-19 pandemic, it is imperative to ensure adequate staffing levels, compensation, and educational support for nurses. The study further propose improving guidelines for emerging infectious diseases and patient classification systems to improve the overall quality of patient care.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.6
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• pp.878-888
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• 2023

Growth responses of Chlorella vulgaris exposed to different light intensities and wavelengths of light-emitting diodes (LEDs) were investigated. C. vulgaris was cultured under red LED (650 nm), blue LED (450 nm), green LED (520 nm), and fluorescent lamps (three wavelengths, control). The maximum growth rates (µ_max) of C. vulgaris were highest under the blue LED, followed by the red LED, green LED, and fluorescent lamps. The low compensation photon flux density (I₀) and low half-saturation constants (K_s) were observed in C. vulgaris cultured under the red LED, indicating that high C. vulgaris growth is closely related to the low light intensity of the red LED suggesting that the red LED can be useful for the biomass production of C. vulgaris. Furthermore, it was observed that under the blue LED during the stationary phase, there was an increase in useful bioactive substances, such as proteins and lipids, which are beneficial for biomass production. In conclusion, the red LED is an economical light source that can enhance cell density, and the blue LED is effective in promoting valuable intracellular substances.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.1
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• pp.89-97
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• 1984

This study was carried out to investigate the effect of seasonal changes on some of the morphological and physiological characteristics, including the photosynthetic abilities and dark respiration, of young ginseng plants due to planting location under shading. The results obtained are as follows: 1. Seedlings and 2-year old plants planted in the back rows appeared to have broader leaf area, and their leaf weight greatly increased in September. Chlorophyll content was significantly reduced in September rather than in June and the plants in the back rows had more chlorophyll content than those in the front rows. 2. There was no difference in the light compensation point between the front and back rows in June, while in September the light compensation point of 2-year old ginseng leaves was much lower for plants in the back rows compared with those in the front rows. A difference in the light saturation point was not noticeable between plants in the front and back rows in June and September. But the light saturation point of 2-year old ginseng leaves at $15^{\circ}C$ was high in June, while it was high at $20^{\circ}C$ high in September. 3. Maximum photosynthetic ability was attained at $15^{\circ}C$ in June and at $20^{\circ}C$ in September. During June no significant difference in photosynthetic ability was found between plants in the front and back rows, but in September the amount of photosynthesis was significantly increased at the leaves of seedlings as well as 2-year old plants planted in the back rows. 4. The optimum temperature for maximum photosynthesis in 2-year old plants ranged from $14.0^{\circ}C$ to $14.5^{\circ}C$ in June and from $19.5^{\circ}C$ to $20.5^{\circ}C$ in September. However, the optimum temperature for maximum photosynthesis in the seedlings was from $21.2^{\circ}C$ to $21.6^{\circ}C$ in September, but a significant difference in the optimum temperature for the maximum photosynthesis in seedlings and 2-year old plants was not noticeable between the front and back rows. 5. The respiration rate was rather high in seedlings compared with 2-year old plants. During September the respiration rate in seedlings was much lower in the back rows than in the front rows. The rate of increase in the respiration of 2-year old plants was higher at September than June. The increase in respiration rate due to temperature was more significant in seedlings than 2-year old plants. 6. In September, the level of $Q_{10}$ in 2-year old plants was much lower than that found in seedlings. During June, 2-year old plants showed lower $Q_{10}$ levels at a temperature difference between $15^{\circ}C$ and $25^{\circ}C$; but in September this occurred at a temperature difference between $20^{\circ}C$ and $30^{\circ}C$.

• Journal of Bio-Environment Control
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• v.9 no.3
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• pp.171-178
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• 2000

Gross photosynthetic rats of leaves of hydroponically grown cucumber plants(Cucumis sativus L. cv. Guwoosalichungjang) were measured under various conditions of photosynthetic photon flux(PPF), ambient $CO_2$ concentration, air temperature and leaf nitrogen contents. Light compensation point of leaf photosynthesis appeared to be in the range of 10~20$\mu$mol.m$^{-2}$ .s$^{-1}$ and light saturation point be above 1000$\mu$mol.m$^{-2}$ .s$^{-1}$ . Gross photosynthetic rates increased persistently and asymptotically as air temperature rose from 12$^{\circ}C$ to 32$^{\circ}C$. However, there were only small differences in gross photosynthetic rates in the range of 24-32$^{\circ}C$, so that the range seemed to be optimal for photosynthesis of cucumber plants at the condition of $CO_2$ concentration of 400$\mu$mol.mol$^{-1}$ and PPF of around 400$\mu$mol.m$^{-2}$ .s$^{-1}$ . $CO_2$ compensation point of leaf photosynthesis appeared to be in the range of 20-40$\mu$mol.mol$^{-1}$ and $CO_2$ saturation point be above 1200$\mu$mol.mol$^{-1}$ . Gross photosynthetic rates increased sigmoidally as leaf nitrogen content increased. These environmental factors interacted synergistically to enhance gross photosynthetic rate, so that the rate increased multiplicatively s level of one factor increased progressively with higher levels of he other factors. Mathematical models wer developed to estimate the gross photosynthetic rate in accordance with the variations of these environmental factors. These modes can be used not only to explain he variation of growth or yield of cucumber plants under different environmental conditions but also as building blocks of plant growth model or expert system of cucumber plants.