• Journal of Sericultural and Entomological Science
• /
• v.25 no.2
• /
• pp.32-36
• /
• 1984

This study was conducted out to evaluate the efficacy of insecticides, furadan (3%G), disyston(5%G), ortran (50%WP), pirimor (50%EC) and metasystox (25%EC) to the mulberry thrips(Pseudodendrothrips mori NIWA.) The comparisons between damaged by thrips and controlled leaves with the cocoon producion and the chemical contents in leaves were carried. The results were as follows; 1. Ortran, furadan and matasystox showed the good efficacy to control the thrips, especially the period of efficacy was the longest in ortran and furadan. 2. The cocoon yield increased in the controlled plot by 3.68kg/box and 5.15kg/10a more than in the damaged plot in autumn rearing season. 3. The content of total carbohydrate and water in mulberry leaves was clearly higher in the controlled plot than in the damaged plot. This may cause the earlier leave harding by damage in autumn.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.19 no.6
• /
• pp.552-557
• /
• 2006

Electrical, optical, surface, and structural properties of amorphous indium-zinc-oxide (a-IZO) grown by box cathode sputtering (BCS) were compared with crystalline indium-tin-oxide (c-ITO) anode films grown by conventional DC sputtering (DCS). Although x-ray diffraction plot of BCS-grown IZO film shows amorphous structure, the optical and electrical properties of a-IZO is comparable to those of c-ITO film. In particular, BCS-grown IZO films shows very smooth surface without defects such as pin hole and cracks because most of the energy of the sputtered atoms was confined in high density plasma region in box cathode gun. Furthermore polymer organic light emitting diodes (POLED) with the a-IZO anode film shows better electrical properties than that of POLED with the c-ITO anode film due to high work function and smooth surface of a-IZO. This suggested that BCS-grown a-IZO film is promising anode materials substituting conventional c-ITO anode in OLED and flexible displays.

• Journal of the Korean Data and Information Science Society
• /
• v.28 no.5
• /
• pp.959-970
• /
• 2017

In this study, we propose bivariate skewness and kurtosis statistics and suggest a surface plot that can visually implement bivariate data containing the correlation coefficient. The skewness statistic is expressed in the form of a paired real values because this represents the skewed directions and degrees of the bivariate random sample. The kurtosis has a positive value which can determine how thick the tail part of the data is compared to the bivariate normal distribution. Moreover, the surface plot implements bivariate data based on the quantile vectors. Skewness and kurtosis are obtained and surface plots are explored for various types of bivariate data. With these results, it has been found that the values of the skewness and kurtosis reflect the characteristics of the bivariate data implemented by the surface plots. Therefore, the skewness, kurtosis and surface plot proposed in this paper could be used as one of valuable descriptive statistical methods for analyzing bivariate distributions.

• Journal of Engineering Education Research
• /
• v.17 no.2
• /
• pp.3-10
• /
• 2014

How to teach calculus is an important issue since Calculus is the first mathematics in college curriculum which highly influences other subjects including Physics, Engineering Mathematics like differential equations, and other engineering major subjects. This study suggests that a class model of Engineering Mathematics include Calculus review test so that students can study for themselves Calculus 'outside Calculus class'. First of all, a systematic process of administrating a review test is presented. Secondly, scores of the Calculus review test is statistically analyzed to confirm that ability in Calculus is highly correlated to their achievements in Engineering mathematics. Through a survey, it is confirmed that students in Engineering Mathematics study Calculus for themselves as they think Calculus review test is helpful.

• Communications for Statistical Applications and Methods
• /
• v.14 no.1
• /
• pp.241-254
• /
• 2007

This paper propose a new short-term interest rate model having a different nonlinear drift function and the same diffusion coefficient with Chan et al. (1992) model. The fractional polynomial power of the drift function in our model is linked to the local volatility elasticity of the diffusion coefficient. While the nonlinear drift function estimated by $A\"{\i}t$-Sahalia (1996a) and others has a feature that higher interest rates tend to revert downward and low rates upward, the drift function estimated by our nonlinear model shows that higher interest rate mean-reverts strongly, but, medium rates has almost zero drift and low rates has a very small drift. This characteristic coincides the empirical result based on the nonparametric methodology by Stanton (1997) and the implication by the scatter plot of the short rate data.

• Asian Journal of Turfgrass Science
• /
• v.13 no.3
• /
• pp.171-176
• /
• 1999

Chrysanthemum showed worse grow of wilt to death during summer at the field which is Allium fistulosum (welsh onion) plants had been cultivated. This study was carried out to analysis of activative inhibitors of chrysanthemum from root exudate of Allium fistulosum. Bioassay experiments with welsh onion root exudate were conducted and the biologically active compounds were determined. The results were obtained as follows. The root exudate of welsh onion inhibited root and hypocotyl growth of chrysanthemum and lettuce at low concentration(10ppm). The inhibitory effects was higher in closed bottom box but with drain hole than in open bottom box plot. The inhibitory substance contained in root exudate was analysed as vanillic acid. This phenolic acid was also detected in stem-leaf and root of welsh onion.

• 한국생물공학회:학술대회논문집
• /
• 2003.10a
• /
• pp.351-355
• /
• 2003

Response surface methodology was employed to study the interactive effect of sucrose, nitrogen, temperature and to optimize their levels to enhance the production of human granulocyte-macrophage colony-stimulation factor from Nicotiana tabacum cell suspension cultures. A 15-runs Box-Behnken design including three center points was the response surface method selected for the initial set of experiments. The analysis of the data from the Box-Behnken experiments showed interactive effects of sucrose:nitrogen, sucrose:temperature and nitrogen:temperature. The optimal combinations of sucrose, nitrogen and temperature for hGM-CSF production from surface plot were sucrose 90 g/L, nitrogen 41 mM and 22$^{\circ}C$, respectively. The optimization of there factors enhanced the hGM-CSF production by 2 times because high sucrose concentration stimulated the secretion of hGM-CSF and low temperature prevented hGM-CSF degradation in media by pretenses.

• Industry Promotion Research
• /
• v.9 no.2
• /
• pp.13-22
• /
• 2024

The purpose of this study is to derive passenger trends and change rates for each airline and identify directionality and synchronization phenomenon. Data by each airlines was collected from the National Statistics Forum of Statistics Korea, and we used a total of 156 monthly data from January 2011 to December 2023. In this study, the rate of change was calculated for domestic Full Service Carriers (Korean Air, Asiana Airlines) and Low Cost Carriers (Jeju Air, Jin Air, T'way, foreign airlines). As a result of the analysis, the correlation was found to be high for KOREA in that order: Asiana, Korean Air, Jeju Air, T'way, Jin Air, foreign airlines. The rate of increase was highest in that order: T'way, Jin Air, Jeju Air, foreign airlines, Asiana, Korean Air. In the Scatter analysis, Asiana and Korean Air showed a very strong synchronization with KOREA. In addition, Jeju Air, T'way, Jin Air and foreign airlines also showed the same direction toward KOREA to a certain degree. In the Box-Box Plot analysis, it was determined that each airline experienced a number of unusual sudden fluctuations due to the outbreak of COVID-19. Passengers have a wider range of choices due to the emergence of Low Cost Carriers, and as a result, expectations for airline service are increasing. Airlines will need to make appropriate environmental improvements to satisfy these needs for corporate development.

• Journal of Digital Convergence
• /
• v.17 no.10
• /
• pp.169-176
• /
• 2019

Recently, the Korean economy is congested with Japan's economic retaliation, the US-China trade war, the Bank of Korea's 0.25% base rate cut and Korea's economic growth forecast revision. The purpose of this study is to analyze the KOSPI, CPI, Treasury bonds(3 years) Interest rate & sales performance of all industries, and examine the impact of each index on the KOSPI. The analysis period is from January 2003 to June 2019, and the effect of each index on the KOSPI is analyzed. In numerical analysis, we performed correlation coefficients and regression analysis. In the model analysis, the distribution, quadrant, scatter, box-plot and impulse response were examined. This study examined the volatility and dynamic characteristics of each index. As a result, the KOSPI showed a high correlation with sales and Treasury bonds, but showed a very low correlation with the CPI. The KOSPI will continue to be affected by sales and interest rates.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2023.05a
• /
• pp.192-192
• /
• 2023

우량계는 강우 자료를 수집하는 전통적인 방법 중 하나로, 연속적이고 직접적인 설치가 가능하다. 하지만 지형적 특성에 영향을 받아 강우량을 과소 측정하는 문제점이 있다. 이러한 문제를 해결하기 위해 국지적인 호우, 강우 이동 및 강우 상황 등을 파악할 수 있는 레이더를 이용한 강우 측정이 활용된다. 하지만 레이더 기반 측정 또한 우량계와 마찬가지로 과소 측정하는 문제점이 있다. 측정 한계를 극복하기 위해 최근에는 위성 기반 강우 자료를 사용하고 있다. 위성 기반의 강우 자료는 측정이 어려운 장소에서도 강우량의 수집이 가능하며, 지표 변화를 관측하여 강우 측정의 정확도를 높일 수 있다. 고화질 위성 자료인 CHIRPS (Climate Hazards Group InfraRed Precipitation with Stations) 자료는 미국 국제개발처, 항공우주국, 해양 대기청의 지원으로 1980년부터 현재까지 전 지구적 (50°S-50°N, 180°E-180°W) 0.05° × 0.05°의 해상도를 가진 강우량 데이터를 개발하였다. 본 연구에서는 전국 54개 ASOS (Automated Synpotic Observing System)에서 관측한 월 단위 및 일 단위 강우 자료를 기준으로 CHIRPS 강우 자료를 비교하였다. 또한, 다른 위성 강우 자료들 (APHRODITE (Asian Precipitation Highly Resolved Observation Data Integration Towards Evaluation), CMORPH (Climate Prediction Cneter morphing method))과도 비교하여 국내 적용성을 확인하였다. 강우 자료의 정확도를 비교하기 위해서 Box-plot, RMSE (Root Mean Squared Error) 등을 산정하였으며, 강우 발생 일을 비교하고자 오차 행렬을 활용하였다. 비교 결과를 통해서 CHIRPS 강우 자료가 다른 위성 강우 자료들에 비해서 국내 적용성이 높은 것을 확인할 수 있었으며, 추후 국내 수문학 연구에서 기초자료로서 활용될 수 있을 것으로 판단된다.