• 한국버섯학회지
• /
• 제11권3호
• /
• pp.145-148
• /
• 2013

목이버섯의 톱밥종균을 제조하는데 참나무톱밥은 영양원으로 미강을 20%첨가하고, 포플러톱밥은 밀기울을 10%첨가하였을 때 목이버섯의 균사와 밀도가 양호하였다. 이때 봉지재배에 적합한 종균 접종양은 참나무톱밥종균은 15 g, 포플러톱밥종균은 25 g를 접종할 때 오염발생률이 줄고 배양완성률이 높아 적합한 접종양 이었다.

• 한국조경학회지
• /
• 제27권1호
• /
• pp.122-131
• /
• 1999

Indoor environments are usually less than optimal for the growth of ferns, especially in regards to the water condition. These studies were performed to investigate responses involved in causing growth of ferns and presume management plan against the water deficit under indoor conditions. The effect of air humidity and soil moisture on the ferns was examined in Adiantume raddianum and Selaginella kraussiana. Results of experiments are as follows; 1. Under a low humidity condition, having a 25-50% RH. ornamental value of ferns decreased much more than under a 90% RH. Under a low soil moisture, such as sand treatment, ornamental value of ferns also decreased. 2. Leaf chlorophyll content, water content and stomata situations increased as air humidity and soil moisture went up. 3. Even if air humidity and soil water were not enough for ferns growth, the extending of irrigation cycle was helpful. 4. Under extremely low air humidity conditions, some water management, namely, using water holding soil or extending of irrigation cycle was desirable. Other methods of increasing air humidity, including water instruments such as ornamental pools, waterfalls, or fountains, grouping plants together were also helpful. But spraying water on leaves increased injury to ferns growth because of excess evaporation from the leaves. Though these studies, we learn that ferns are susceptible to water condition such as air humidity, soil water and water management. If other environmental factos are maintained with optimal conditions, water condition plays an important role in ferns growth in indoor environments.

• 한국경영과학회:학술대회논문집
• /
• 한국경영과학회 2001년도 추계학술대회 논문집
• /
• pp.157-160
• /
• 2001

Firms pursue new business opportunities for growth. Market development strategy is one of the growth strategies, which develops new market segments with current products. However, new market generally has high uncertainty, or high risk. Firms should consider the risk in making and implementing the market development strategy. In this paper, an optimal marketing resource allocation model is developed, taking into account the risk attitude of a firm in market development. Under the assumption of exponential utility function, the global optimal solution is derived, and the implications are provided.

• 한국멀티미디어학회논문지
• /
• 제19권11호
• /
• pp.1891-1899
• /
• 2016

Recently food problem and crop disaster have been increased continuously because of the meteorological changes. These cause rising cost for crops continuously and irregularly. Some researchers have studied straight structure of device for hydroponics and plant factory previously to solve a fundamental part of these problems. However, there are several problems such as limited crop cultivation space, providing irregular nutrients for crops, and lack of monitoring interfaces. For them, we propose an optimal growth and development crops management system using light source tracking and recirculation of nutrient solution method to supply nutrient continuously based on IoT. In order to evaluate the performance of our system, we compared and analyzed in terms of two viewpoints, the tracking analysis for natural light source measurement and the growth of crops through artificial light, LED, respectively. We confirmed that the higher the duty ratio of LED, the larger the crop's size, particularly. As well as, for about 1 month, we compared with the existing natural light growing environment and that of our system. It was confirmed that the size of the crops grown through our system is about three times larger than that of natural light natural crops.

• 품질경영학회지
• /
• 제39권2호
• /
• pp.170-178
• /
• 2011

In general, a software fault detection phenonenon is described by a software reliability model based on a nonhomogeneous Poisson process(NHPP). In this paper, we propose a software reliability growth model considering the differences of the software environments in both the testing phase and the operational phase. Also, we consider the problem of determining the optimal release time and the optimal warranty period that minimize the total expected software cost which takes account of periodic software maintenance(e.g. patch, update, etc). Finally, we analyze the sensitivity of the optimal release time and warranty period based on the fault data observed in the actual testing process.

• 품질경영학회지
• /
• 제23권2호
• /
• pp.53-67
• /
• 1995

The problem considered here is to find the optimal discriminant analysis method in growth curve model. It has been studied how to find correct prior probability for the effective classification in discriminant analysis. We use the balanced condition to calculate prior probability. From the informative simulation study, new classification rule for the growth curve model is suggested. The suggested classification rule has better classification result than the other previously suggested method in terms of error rate criterion.

• 아태비즈니스연구
• /
• 제13권2호
• /
• pp.123-138
• /
• 2022

Purpose - This study compares the performances of dynamic asset allocation strategies using Korean stocks and U.S. dollar, which have been negatively correlated for a long time, to examine the diversification effects in the portfolios of them. Design/methodology/approach - In the current study, we use KOSPI200 index, as a proxy of the aggregated portfolio of Korean stocks, and USDKRW foreign exchange rate to implement various portfolio management strategies. We consider the equally-weighted, risk-parity, minimum variance, most diversified, and growth optimal portfolios for comparison. Findings - We first find the enhancement of risk adjusted returns due to risk reduction rather than return increasement for all the portfolios of consideration. Second, the enhancement is more pronounced for the trading strategies using correlations as well as volatilities compared to those using volatilities only. Third, the diversification effect has become stronger after the global financial crisis in 2008. Lastly, we find that the performance of the growth optimal portfolio can be improved by utilizing the well-known momentum phenomenon in stock markets to select the length of the sample period to estimate the expected return. Research implications or Originality - This study shows the potential benefits of adding the U.S. dollar to the portfolios of Korean stocks. The current study is the first to investigate the portfolio of Korean stocks and U.S. dollar from investment perspective.

• 한국토양비료학회지
• /
• 제49권6호
• /
• pp.699-704
• /
• 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.

• 경영과정보연구
• /
• 제9권
• /
• pp.65-80
• /
• 2002

As the growth of Internet business, many web sites have been developed their own Internet business strategies. Yet, many web sites have difficulties to make profit. In this paper, an economic model is developed to analyze web sites' quality and pricing strategies when they initiate their services as free services and develop advertising services and other charged services. By analyzing the economic model, optimal quality and prices was found. And by analyzing the optimal strategy, I found that web sites should properly decide their market share on initial customer. Finally, the importance of web sites' productivity to make profit is emphasized.

• 경영과학
• /
• 제18권2호
• /
• pp.87-96
• /
• 2001

Mobility of service users makes Registration and Paging (R/P) procedures indispensable features in mobile communication networks. Importance of optimizing the configuration of R/P areas has been increased by the growth of R/P related signaling. Given the network topology (cell locations and adjacency between them) and R/P related traffics generated by each cell, we deal with the problem of finding optimal R/P areas minimizing the amount of R/P related signalling while the constraints on paging channel capacity and network configurations are satisfied.