• Proceedings of the Technology Innovation Conference
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• 1999.06a
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• pp.98-118
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• 1999

This study deals with the knowledge acquisition activities along the growth stages of Korean ventures. This issue is very important in the three reasons. First, the target of the study-new ventures- is a pending issue and can be regarded as the engine of innovation in the Korean economy. Second, venture activities is so dynamic compared to those of the established companies and the study reflects its dynamic features. Third, the knowledge is becoming more important one among various resources, and knowledge management can be a timely issue. The main research questions are as follows : - How does the degree of knowledge domain, vary along the growth stages\ulcorner - Which knowledge domains are more influential on the performance along growth stages\ulcorner Major findings of the study are as follow: First, technological knowledge acquisition effort are most intensive at the start-up stage, while the management knowledge efforts are active at the growth stage. The degree of market knowledge acquisition efforts is almost the same along the stages. Second, the important knowledge domain, which influences on the performance, varies along the stages. The acquisition effort for product technology knowledge is more influential on the sales growth rate and has a negative effect on the return on assets at the start-up stage, while the management knowledge about administration is more influential on the return on assets at the growth stage. Finally the academic contributions and managerial implications of the study are presented and the future research directions are also suggested.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.3
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• pp.141-147
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• 2019

The purpose of this study was to determine the effect of waterlogging duration on the growth characteristics and productivity of forage corn at different growth stages under paddy field conditions. Treatments consisted of waterlogging at two growth stages (V7 or V14) for four waterlogging durations (no waterlogging, 48 hours, 72 hours, and 96 hours, respectively). The V14 growth stage was more vulnerable to waterlogging than the V7 stage. Among the waterlogging durations, the lodging score increased at 48 hours. The stem height of forage corn decreased with the increase in waterlogging duration at the different growth stages (V7 and V14). Increase in waterlogging duration reduced the stem dry matter yield, ear dry matter yield, and total dry matter yield at both growing stages (V7 and V14). The waterlogging treatments at the V14 stage affected ear dry matter yield more than those at the V7 growing stage. Thus, the management of forage corn under paddy field conditions must be strengthened during early (V7) and grain fill stages (V14). When waterlogging occurs, surface and subsurface drainage should be implemented within 48 hours to control (no waterlogging) the groundwater level and, thus, minimize economic losses due to forage corn damage.

• Korean Journal of Environment and Ecology
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• v.19 no.1
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• pp.1-8
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• 2005

The removal affect of nitrogen and phosphorus were analyzed using a Acorus calamus var. angustatus. The nutrient concentration, growth stage of plants and the storage time of polluted water were considered. The results of this study were as follows: after an hour the content of nitrogen and phosphorus were considerably reduced in the Acorus calamus var. angustatus, while after two-four hours the rate of reduction was extremely low. This situation was the same in the early growth stage, growing stage and highest growth stage of the plant. The removal rate of nitrogen and phosphorus with the Acorus calamus var. angustatus was higher, when these two minerals remained in high levels of water. The Acorus calamus var. angustatus was more effective to remove nitrogen than that of phosphorus. The plant removed the most nitrogen and phosphorus when in the highest growth stage, but this was not clear in the growth stages. The removal rate was higher, in the case of moving polluted water to other plants after two days, than in the case of four days of growth in the same plants.

• Korean Journal of Medicinal Crop Science
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• v.12 no.5
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• pp.372-377
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• 2004

Scopolia parviflora Nakai, a rare and endangered species, is the sole plant producing tropane alkaloids (TA) among the Korean native species. In order to enhance TA productivity the SP72 root line was selected by screening 100 of root line, and the optimal culture media for root growth and TA production were investigated with the SP72 roots. Based on the several media, SH and 2B5 medium were determined as growth medium and White and NN medium as production medium. Among the four combinations of two-stage culture, 2BN (2B5 as growth medium plus NN as production medium) showed more enhanced root growth and TA production as compared with production media of White and NN medium and growth media of SH and 2B5 medium, respectively. However, bubble column bioreactor (BCB) cultures applying two-stage culture did not reveal the effective results despite of the each successful operation of two-stage culture in conical flasks and BCB cultures.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.3
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• pp.282-287
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• 1999

The object of this study was to determine the difference of the time course changes of transpiration, diffusion resistance and photosynthetic rate of rice at several different growth stages subjected to soil moisture stress (SMS) and recovery by irrigation. A japonica rice cultivar 'Dongjinbyeo', was grown under flooded condition in a plastic container filled with silty loam soil. At 5 main growth stages, the container was treated by SMS until initial wilting point (IWP) and then reirrigated. The duration of SMS until IWP were the longest, 13 days for tillering stage, and the shortest, 7 days for panicle initiation and meiosis stage. The transpiration rate rapidly decreased during SMS and the transpiration rate at IWP of the stressed plant showed 10∼20% compared with control, and the transpiration rate of stressed plant at most growth stages also recovered rapidly after irrigation and then reached 100% of control within a week. The shoot photosynthetic rate in all growth stages rapidly decreased by SMS, and the rates at IWP of stressed plants were de-creased nearly to 0%, beside the treatment at tillering stage. The recovery degree of photosynthetic rate by irrigation ranged from 20 to 90%, showed higher at early growth stages of SMS treatment than that of later stages. At all growth stages the leaf diffusion resistance of stressed plants was over 3 times that of the control resulting from a rapid increase at 3 to 5 days after draining for SMS, and showed quick recovery by irrigation within 3 days after drainage. The above physiological parameters changed in close relation with the decrease of the soil matric potential after SMS. These results indicate that at all main growth stages of rice plants the transpiration and photosynthesis reduction by stomatal closure reponded sensitively to the first stage of SMS closely related with decrease of soil water potential, while those recovery pattern and recovered degree by irrigation are little different by growth stage of rice.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.6
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• pp.699-704
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• 2016

An estimation of optimal requirement of additional N by cropping pattern and growth stage is very important for greenhouse watermelon. The objectives of this study were to estimate an amount of optimal additional N based on growth, N uptake and yield of watermelon. In order to achieve these goals, we performed the study at farmer's greenhouse with a fertigation system and watermelon was cultivated three times (spring, summer and autumn) in 2015. The levels of additional N were set up with x0.5, x0.75, x1.0 and x1.5 of the $NO_3$-N-based soil-testing N supply for watermelon cultivation. The trends of growth and N uptake of watermelon markedly differed from cropping pattern; spring (sigmoid), summer and autumn (linear). The yield of watermelon was the highest at summer season and followed by autumn and spring. Also, the x1.5N showed a significantly higher yield compared to other N treatments. On the basis of growth, N uptake and yield of watermelon, we estimated an optimal level of additional N by cropping pattern and growth stage as follows; 1) spring (transplanting ~ 6 WAT : 6 ~ 14 WAT : 14 ~ harvest = 5 : 90 : 5%), summer (transplanting ~ 4 WAT : 4 ~ 8 WAT : 8 ~ harvest = 25 : 50 : 25%) and autumn (transplanting ~ 4 WAT : 4 ~ harvesting : 50 : 50%). In conclusion, nutrient management, especially N, based on cropping pattern and growth stage was effective for favorable growth and yield of watermelon.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.4
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• pp.391-395
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• 1999

Barnyardgrass had relatively higher growth vigor at the earlier growth stage than inbred rice did, showing the 2 fold higher $\alpha$-amylase activity during the periods of germination and large leaf area Expansion with high net photosynthetic rate at the earlier autotrophic stage, but it performed weak growth at the late growth stage. However, the hlybrid rice Shanyou 63 had significantly higher $\alpha$-amylase activity and net photosynthetic rate than that of barnyardgrass, exhibiting heterosis for two physiologica1 traits during the germination (6~12 days) and autotrophic phase, respectively. Accordingly, hybrid rice, Shanyou 63, exhibited heterotic effect at the early growing stage when were presented with barnyardgrass. Shanyou 63 exhibited stronger tillering ability, faster leaf area expansion and higher net photosynthetic rate than those of barnyardgrass.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.970-972
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• 2013

We examined the relative growth of Microstomus achne during early life stages of laboratory-reared larvae and juveniles. Turning points in the relative growth of preanal length and upper jaw length against total length occurred during the settlement period (11.12-19.91 mm in total length). However, turning points in the relative growth of head length and eye diameter, as compared to total length, occurred during metamorphosis (17.57-22.47 mm in total length). Our results suggest that Microstomus achne concentrates its energy on the feeding apparatus (jaw) and digestive organs (intestine) rather than sensory or neural organs (eye, head) during early larval stage growth.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.06a
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• pp.78-80
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• 2022

Strawberry (Fragaria × ananassa) cultivation methods are rapidly changing from traditional soil cultivation to high bed hydroponics, which are easy to agricultural working. The objective was to evaluate the growth characteristics of three strawberry cultivars cultivated high bed system. The "Seolhyang", "Altaking", and "Keumsil" strawberry plants were transplanted in a glass-type greenhouse at Kyungpook National University Gunwi Agricultural Field. The cultivation period was approximately seven months from September 17, 2021 to April 21, 2022. Growth parameters measured including the number of leaves, plant height, petiole length, leaf length, leaf width, and crown diameter at two-week intervals. The environmental parameters for each location in the greenhouse were collected. Plant height in all cultivars continued to decrease from the early stage to the late stage of growth. The crown diameter was increased by 50 DAT, and then gradually decreased until late growth stage in all cultivars. Results indicated that the growth parameters represented to vary according to the cultivar of strawberry plants.

• Journal of Bio-Environment Control
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• v.18 no.1
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• pp.23-28
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• 2009

This study was conducted to evaluate the effect of optimized environment conditions with growth stage in photoautotrophic micropropagation on the growth of potato (Solanum tuberosum L. cv. Dejima) plantlets and energy efficiency. Optimum environment conditions at each stage were decided in our previous study. For the evaluation of optimized environment control, potato plantlets were cultured under four different conditions: photoautotrophic optimum conditions of photosynthetic photon flux density (PPFD) and $CO_2$ levels with growth stage (POG), photoautotrophic constant condition with average PPFD and $CO_2$ levels (PCA), photoauototrophic constant condition with maximum PPFD and $CO_2$ levels (PCM), and photomixotrophic conventional condition with 3% sucrose (PMC) as control. As a result, environment control with growth stage (POG) significantly promoted all the growth characteristics such as the number of nodes and unfolded leaves, shoot height, shoot diameter, and fresh and dry weights of potato grown in vitro. In addition, based on dry weight consumed electricity and $CO_2$ were the lowest in POG suggesting the highest energy efficiency among the treatments. After transferring potato plantlets to greenhouse, the plantlets under POG showed vigorous growth, which was pretty similar with those under PMC. The accumulations of dry matter in POG were 4.7 times in vitro and 3.8 times in greenhouse as much as those in the conventional control (PCM). Thus, we concluded that in vitro environment control with growth stage induced vigorous growth of potato plantlets both in vitro and in greenhouse with less energy consumption.