• Journal of Bio-Environment Control
• /
• v.27 no.3
• /
• pp.231-238
• /
• 2018

Chlorophyll fluorescence, chlorophyll content, graft-taking and growth of grafted cucumber seedlings as affected by photosynthetic photon flux (PPF) of LED lamps were analyzed in this study. Four PPF levels, namely 25, 50, 100, $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ were provided to investigate the effect of light intensity on the chlorophyll fluorescence, chlorophyll content, graft-taking and growth of grafted cucumber seedlings. Air temperature, relative humidity, and photoperiod for graft-taking were maintained at $25^{\circ}C$, 90%, $16h{\cdot}d^{-1}$, respectively. Maximum quantum yield (Fv/Fm) of rootstock as affected by PPF was found to be 0.84-0.85 and there was no significant change in Fv/Fm. Even though Fv/Fm of scion measured at 2 days after grafting was lowered to 0.81-0.82, after then it gradually increased with increasing PPF. At 4 days after grafting, the chlorophyll content extracted from scion increased with increasing PPF. Graft-taking ratio of grafted cucumber seedlings was 90-95% as PPF was ranged from $25{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ to $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. However, the graft-taking ratio of grafted seedlings healed under PPF of $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ was decreased to 80%. Maximum PPF measured required for smooth joining of rootstock and scion was assumed to be $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. At healing stage of grafted cucumber seedlings, Fv/Fm of scion decreased and at least two days after grafting were required for rooting of grafted seedlings. Chlorophyll fluorescence response of rootstock and scion was linked to light irradiation. Therefore, it was concluded that physical environment including light and humidity during healing process of grafted seedlings should be controlled more precisely to facilitate root formation and to prevent scion from lowering Fv/Fm. Further studies are required to investigate the effects of root development and joining of vascular bundles of grafted seedlings on the chlorophyll content of scion.

• Journal of Bio-Environment Control
• /
• v.27 no.3
• /
• pp.260-268
• /
• 2018

The aim of this study was to evaluate the effect of light quality using either monochromatic or combined LEDs on the growth and antioxidant accumulation of Agastache rugosa cultivated under hydroponics for 4 weeks. This experiment was performed in a controlled-environment room at $22{\pm}1^{\circ}C$ and $18{\pm}1^{\circ}C$ (day and night temperatures, respectively) and 50-70% relative humidity, with a provided photosynthetic photon flux density (PPFD) of $180{\pm}5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and irradiated with either monochromatic (W10 and R10) or mixed LEDs (W2B1G1, R3B1, R2B1G1, and W2B1G1) with a differing ratio of each LED's PPFD and fluorescent lighting (FL: control) with a 16/8 h photoperiod. Fresh and dry weights were highest for plants grown under the W2B1G1 treatment. A. rugosa grown with R10 had the greatest plant height but the lowest SPAD among all treatments. The concentration of rosmarinic acid in plants grown under W2B1G1 was significantly higher than that of plants grown under other treatments. Tilianin content was significantly higher in R3B1 than in the other treatments. However, whole-plant rosmarinic acid and tilianin content was the highest under the W2B1G1 condition. To cultivate A. rugosa in a plant factory, mixed-LED light conditions with W2B1G1 is considered to be more advantageous for the growth and antioxidant accumulation of A. rugosa. It is though that the total whole-plant antioxidant content is more crucial for commercial use; the present study demonstrates the potential to achieve higher content of functional materials in plants through the selection of light quality.

• Journal of Bio-Environment Control
• /
• v.27 no.3
• /
• pp.253-259
• /
• 2018

This study set out to select a system to realize an optimal environment for strawberry cultivation greenhouses based on data about the growth and development of strawberry and its environment and to provide basic data for the research of its improved productivity. For these purposes, the investigator conducted a field survey with greenhouses for strawberry cultivation in western Gyeongnam. The findings show that farmers in their fifties and sixties accounted for the biggest part in the age groups of strawberry farmers. While those who were under 50 were accounted for approximately 67.5%, those who were 60 or older accounted for 32.5%. As for cultivation experiences, the majority of the farmers had ten years of cultivation experiences or less with some having 30 years of cultivation experiences or more. All the farmers built an arch type single span greenhouse. Those who used nutrient solutions were about 75.0%, being more than those who used soil. All of the farmers that used a nutrient solution adopted an elevated hydroponic system. The single span greenhouses were in the range of 7.5~8.5m, 1.3~1.8m and 2.5~3.5m for width, eaves, and ridge height, respectively, regardless of survey areas. The rafters interval was about 0.7~0.8m. In elevated hydroponic cultivation, the width, height, and interval of the beds were about 0.25m, 1.2m and 1.0m, respectively. As for the strawberry varieties, the domestic ones accounted for approximately 97.5% with Seolhyang being the most favorite one at about 65.0%. As for the internal environment factors of greenhouses, 38 farmers measured only temperature and relatively humidity. As for hydroponics, the farmers used a hydroponics control system. Except for the farmers that introduced a smart farm system for temperature and humidity control, approximately 85.0% controlled temperature and humidity only with a control panel for side windows and ventilation fans. As for heating and heat insulation, all of the farmers were using water curtains with many farmers using an oil or electric boiler, radiating lamp or non-woven fabric, as well, when necessary.

• Journal of Bio-Environment Control
• /
• v.27 no.4
• /
• pp.400-406
• /
• 2018

In this experiment the effect of supplemental lighting on the growth and yield of cucumber (Cucumis sativus L. 'Fresh') plants during low radiation period of winter season were investigated in glasshouses using common high-pressure sodium (HPS) lamps and newly developed plasma lighting system (PLS) lamps. Plants grown without supplemental lighting were considered as a control. Supplemental lighting was provided from November 20th, 2015 to March 15th, 2016 to ensure 14-hour photoperiod (natural+supplemental light), also lamps were operated automatically when the outside sun radiation levels were less than $100W{\cdot}m^{-2}$. Spectral analysis showed that HPS lamp had a discrete spectrum, lacked of the radiation in the 400-550 nm wave band (blue-green light), but had a high output in the orange-red region (550-650 nm). A higher red light output resulted in an increased red to far-red (R/FR) ratio in HPS lamp. PLS had a continuous spectrum and had a peak radiation in green region (490-550 nm). HPS has 12.6% lower output in photosynthetically active radiation (PAR) but 12.6% higher output in near infra-red (NIR) spectral regions compared to PLS. Both HPS and PLS lamps emitted very low levels of ultra-violet radiation (300-400 nm). Supplemental lighting both from HPS and PLS lamps increased plant height, leaf number, internode number and dry weight of cucumber plants compared to control. Photosynthetic activity of cucumber plants grown under two supplemental lighting systems was comparable. Number of fruits per cucumber plant (fruit weight per plant) in control, PLS, and HPS plots were 21.2 (2.9 kg), 38.7 (5.5 kg), and 40.4 (5.6 kg), respectively, thereby increasing yield by 1.8-1.9 times in comparison with control. An analysis of the economic feasibility of supplemental lighting in cucumber cultivation showed that considering lamp installation and electricity costs the income from supplemental lighting increased by 37% and 62% for PLS and HPS lamps, respectively.

• Journal of Bio-Environment Control
• /
• v.27 no.4
• /
• pp.332-340
• /
• 2018

Supplemental lighting with artificial light sources is a practical method that enables normal growth and enhances the yield and quality of fruit vegetable in greenhouses. The objective of this study was to investigate the effect of sulfur plasma lamp (SP) and high-pressure sodium lamp (HPS) as supplemental lighting sources on the growth and yield of paprika. For investigating the effectiveness of SP and HPS lamps on paprika, the effects of primary lighting on plant growth were compared in growth chambers and those of supplemental lighting were also compared in greenhouses. In the growth chamber, plant height, leaf area, stem diameter, number of leaves, fresh weight, and dry weight were measured weekly at SP and HPS from 2 weeks after transplanting. In the greenhouse, no supplemental lighting (only sunlight) was considered as the control. The supplemental lights were turned on when outside radiation became below $100W{\cdot}m^{-2}$ from 07:00 to 21:00. From 3 weeks after supplemental lighting, the growth was measured weekly, while the number and weight of paprika fruits measured every two weeks. In the growth chamber, the growth of paprika at SP was better than at HPS due to the higher photosynthetic rate. In the greenhouse, the yield was higher under sunlight with either HPS or SP than sunlight only (control). No significant differences were observed in plant height, number of node, leaf length, and fresh and dry weights between SP and HPS. However, at harvest, the number of fruits rather than the weight of fruits were higher at SP due to the enhancement of fruiting numbers and photosynthesis. SP showed a light spectrum similar to sunlight, but higher PAR and photon flux sum of red and far-red wavelengths than HPS, which increased the photosynthesis and yield of paprika.

• Journal of Bio-Environment Control
• /
• v.29 no.2
• /
• pp.141-152
• /
• 2020

The rapid on-site measurement of hydroponic nutrients allows for the more efficient use of crop fertilizers. This paper reports on the development of an embedded on-site system consisting of multiple ion-selective electrodes (ISEs) for the real-time measurement of the concentrations of macronutrients in hydroponic solutions. The system included a combination of PVC ISEs for the detection of NO₃, K, and Ca ions, a cobalt-electrode for the detection of H₂PO₄, a double-junction reference electrode, a solution container, and a sampling system consisting of pumps and valves. An Arduino Due board was used to collect data and to control the volume of the sample. Prior to the measurement of each sample, a two-point normalization method was employed to adjust the sensitivity followed by an offset to minimize potential drift that might occur during continuous measurement. The predictive capabilities of the NO₃ and K ISEs based on PVC membranes were satisfactory, producing results that were in close agreement with the results of standard analyzers (R² = 0.99). Though the Ca ISE fabricated with Ca ionophore II underestimated the Ca concentration by an average of 55%, the strong linear relationship (R² > 0.84) makes it possible for the embedded system to be used in hydroponic NO₃, K, and Ca sensing. The cobalt-rod-based phosphate electrodes exhibited a relatively high error of 24.7±9.26% in the phosphate concentration range of 45 to 155 mg/L compared to standard methods due to inconsistent signal readings between replicates, illustrating the need for further research on the signal conditioning of cobalt electrodes to improve their predictive ability in hydroponic P sensing.

• Korean Journal of Biological Psychiatry
• /
• v.13 no.4
• /
• pp.279-288
• /
• 2006

Objectives : We investigated the association of SNP A and P1763 polymorphisms on dystrobrevin binding protein 1(DTNBP1) gene with smooth pursuit eye movement(SPEM) abnormality in Korean schizophrenic patients. Methods : We measured SPEM function in 217 Korean schizophrenics(male 116, female 101) and divided them into two groups, one is a good SPEM function group and the other is a poor SPEM function group. We then analyzed SNP A polymorphism and P1763 polymorphism on DTNBP1 gene from their DNAs extracted from their blood. We compared the differences of genotype and allele distributions of the two polymorphisms on DTNBP1 gene between the two groups. Results : The Ln S/N ratio(mean${\pm}$SD) of the good SPEM function group was $4.39{\pm}0.33$ and the ratio of poor SPEM function group was $3.17{\pm}0.71$. There were no statistically significant differences of age and male/female ratio between the two groups. There were no significant differences of genotype or allele distributions of the SNP A polymorphism and P1763 polymorphism on DTNBP1 gene between the two schizophrenic groups divided by SPEM function. Conclusion : The results suggest that SNP A polymorphism and P1763 polymorphism on DTNBP1 gene might not be related to SPEM function abnormality in schizophrenia.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.6 no.1
• /
• pp.109-132
• /
• 2011

While the resource-based view suggests that a firm's competitive advantage rests on a set of valuable, rare and inimitable resources more generally (Barney, 1991), research in new firms has more specially indicated a link between initial resources and early performance and survival (Bruderl and Schussler, 1990; Fichman and Levinthal, 1991; Carroll et al., 1996). The RBV primarily focuses on the particular resources, and their characteristics, that provide the potential for advantage (Conner, 1991). Yet in order to realize this advantage, organizations must not only develop their resources, but also effectively deploy them (Admit and Shoemaker, 1993). This suggests that advantage from resources may reside in both the input (resource development) side and the output (resource deployment) side. This research looks at venture survival as a function of both the resources a firm owns, and the resources it can access from others. We focus more specifically on technology resources, which are among a technology-based firm's most critical resources (Itami, 1987). In addition, technological knowledge can contribute a large portion of the value of a firm's products (Goodman and Lawless, 1994). We look at both the input and output side: the pool of technology resources that serve as an input to a firm's activities, and the market that values and purchases the output of this activity. We take an international perspective, examining whether resources explain internationalization on the input and output side, and in turn, whether this internationalization can explain survival. We explore three sets of questions. First, can survival in entrepreneurial firms be explained as a function of the resources a firm owns, and beyond that, to those the firm can access, and still further, to those the firm can access internationally? Second, do resources explain internationalization on both the input and output side? And finally, does internationalization explain survival? Implications for theory include extending the RBV to not only include a firm's resources, but its access to the resources of other entities. In addition, examining internationalization on both the input and output side enables us to understand not just the potential advantage of resources, but the manner in which they are deployed as a source of advantage. This research also contributes to the literature on international entrepreneurship by examining whether internationalization can explain survival for early stage firms. For practitioners, this research will provide insights on the importance of building alliances and, in so doing, broadening an organization's perspective about the technology resources available to the firm on the input side. The study will also inform practitioners about the value of maximizing the market for a firm's valuable resources. In addition, this research provides an extraordinary opportunity to access a large, comprehensive, and longitudinal dataset on technology-based ventures in Korea.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.3 no.1
• /
• pp.73-103
• /
• 2008

Over the past few years, "business models" has surged into the management vocabulary. But, while it has become quite fashionable to discuss business models, there has been still much confusion about what are business models and how they could make. In fact, business models can serve a positive and powerful role in corporate management. While other authors have recently offered definitions of "business model", none of them appears to be generally accepted. This paper presents the absence of the generally definition of the business models, elements of business model and classify business logic. To help start-up entrepreneurs better understand, found and check business models thus, this paper propose a method of business model, understanding, founding and checking. The dissertation will present an effective business model building method which is necessary for the start-up entrepreneurs to start business. This paper consists of three parts. first is showing the previous study of business model. The second is the re-definition business model and elements based on the first and to present a new method of business model plating and checking for start-up IT (information technology) company's entrepreneurs. The last is application of the methode. This study applied the methode to a company which is located in "DAEDEOK INNOPOLIS"; this company has specialized Information technology.

• Geophysics and Geophysical Exploration
• /
• v.13 no.4
• /
• pp.357-363
• /
• 2010

In this study, we investigated the geologic structure of the basement and overlying sediments of the construction site of the dinosaur egg fossil museum in Hwasung, Gyeonggi Province through refraction seismology, drilling, and downward seismic velocity measurements in the drill holes. The construction site ($350{\times}750\;m^2$) is located in the reclaimed area south of Sihwa Lake, Gojeong-ri. About 6,950 m of seismic refraction data consisting of 11 lines were acquired using a sledge hammer source. Drilling to the basement was performed at five sites. Sediment samples from drilling were analysed for grain-size distribution and age dating. At two drill holes, seismic velocity was measured with depth using a hammer as a seismic source. The geological structure of the study area consists of, from top to bottom, a tidal flat layer (5 ~ 12 m thick), a weathered soil layer (2 ~ 8 m thick), and the basement. The basement is interpreted as Cretaceous sedimentary rocks that tend to be shallow eastward. The volume of the tidal flat sediments and weathered soil in the study area is estimated as $1.4{\times}10^6\;m^3$, weighing $3.5{\times}10^6$ tons. The rate of sea level rise since 8,000 yrs BP is estimated to be 0.1 ~ 0.15 cm/yr.