• Journal of Bio-Environment Control
• /
• v.7 no.4
• /
• pp.276-282
• /
• 1998

This experiment was carried out to elucidate the effect of ethychlozate foliar application on the fruit quality of Miyagawa Early Satsuma Mandarin in the plastic house. Ethychlozate(100mg.L$^{-1}$ ) was applied to the fruit at 100, 115 and 145 days after full bloom stage. The fruit was divided into four frequency level groups, with the control group receiving no Ethychlozate treatment and the level 3 group receiving all three applications. Peel coloration by a value Increased as application frequency increased. The a/b value trend was seen to be similar to this, but the b value ran contrary to the a value trend. Glucose contents of the fruit juice did not differ statistically among the application frequency levels but the fructose level was seen to be higher with increasing application frequency. Sucrose showed a similar trend to fructose in that it had a tendency to increase as application frequency increased. As a result of this, total sugar increased naturally with application frequency. The average Brix level among all treatment groups was higher than the average Brix level in the control group but Brix level did not differ significantly among application frequency levels. Acidity had a tendency to increase as application frequency increase, but there was no statistical difference found.

• Korean Journal of Plant Resources
• /
• v.19 no.2
• /
• pp.199-203
• /
• 2006

The marketability of soybean sprout mainly depends on shape such as hypocotyl thickness and presence of lateral root formation, etc. To clarify the effects of agitating culture box on growth and shape of soybean sprouts, different agitation frequency (0, 3, 5 times day-1) and duration (0, 1, 2, 3 days) were applied during sprout cultivation. More frequent and longer agitation resulted in less lateral root formation and shorter hypocotyl length, while total lengths were not affected by agitation due to agitation-induced root length increment. Agitation also increased the diameter of hypocotyl's hook pin, but not the middle part. Unlike morphological characteristics, the growth of sprouts as measured by fresh and dry weight of cotyledon, hypocotyl, root were not affected by agitation. In conclusion, it is very likely that agitating culture box during sprout cultivation may alter the shape of soybean sprouts without affecting growth of sprouts.

• The Journal of the Korea Contents Association
• /
• v.20 no.2
• /
• pp.352-359
• /
• 2020

This study utilizes raw data from the first-ever Korea National Health and Nutrition Examination Survey (KNHANES) conducted in 2017 and its purpose is to identify factors that influences Daily toothbrushing frequency and use of oral health care products for adolescents aged 13 to 18 years in conjunction with their mothers. Factors affecting Daily toothbrushing frequency of adolescents are: Whether the mother smokes or not, and Daily toothbrushing frequency for the mother. The more the mother younger and smoked and brushed her teeth, the higher the number of sessions increased for the adolescent child. The higher the mothers' level of education and use of oral care products were the greater the adolescent child's use of oral care products became. As a result, the study determined that the oral health of adolescents and of their mothers are closely related. A program to educate adolescents and mothers to promote the oral health of adolescents should be developed, and continuously and systematically implemented at home and school.

• Journal of Korean Society of Transportation
• /
• v.25 no.5
• /
• pp.111-122
• /
• 2007

This paper investigates the rail service patterns by train class. The emphasis in intercity rail planning is to more efficiently use of existing station facilities. Rail transit operations are affected by the system layout and ridership patterns and by work rules. Operations are also influenced by past practices and the institutional setting. Main factors to decide train service patterns are the location, socioeconomic characteristics, land use and travel demand of the station. In this context, the travel demand of intercity rail station is of crucial significance. Tests on a KTX case shows that train service frequency can be efficiently decreased in weekday to transport the same passenger demand. The work has shown many subjects that need further research including various factors influencing on train frequency. This study serves the railroad authorities in planning and determining business strategy in the increasingly competitive environment of regional rail transport.

• Journal of the Korean Society of Radiology
• /
• v.17 no.1
• /
• pp.141-148
• /
• 2023

The algebraic reconstruction technique is one of the reconstruction methods in CT and shows good image quality against noise-dominant conditions. The number of iteration is one of the key factors determining the execution time for the algebraic reconstruction technique. However, there are some rules for determining the number of iterations that result in more than a few hundred iterations. Thus, the rules are difficult to apply in practice. In this study, we proposed a method to determine the number of iterations for practical applications. The reconstructed image quality shows slow convergence as the number of iterations increases. Image quality 𝜖 < 0.001 was used to determine the optimal number of iteration. The Shepp-Logan head phantom was used to obtain noise-free projection and projections with noise for 360, 720, and 1440 views were obtained using Geant4 Monte Carlo simulation that has the same geometry dimension as a clinic CT system. Images reconstructed by around 10 iterations within the stop condition showed good quality. The method for determining the iteration number is an efficient way of replacing the best image-quality-based method, which brings over a few hundred iterations.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2020.08a
• /
• pp.53-53
• /
• 2020

가뭄이 매년 지속됨에 따라 고랭지배추 재배지에서도 관수의 필요성이 인식되면서 관수를 실시하고 있으며, 대부분 스프링클러로 관수하고, 분수호스나 점적호스도 일부 이용하고 있으나 아직 토양수분, 토성이나 작물상태, 재배시기 등 환경요인을 고려한 과학적인 수분관리가 이루어지지 못하고 있어 고품질 안정생산을 위해서는 수분관리의 과학화가 필요한 실정이다. 물을 최소화 하면서 관비가 가능한 점적 호스 재배는 적정한 비료를 필요한 위치에 공급하는 방식으로 비료의 효율을 높이면서 환경오염을 최소화하고, 비료과다 시용에 따른 환경오염 등을 회피할 수 있는 좋은 수단이다. 본 연구는 앞으로 고랭지배추 점적호스 재배시 가뭄 극복과 효율적인 시비를 위한 적정 관비횟수를 구명하고자 하였다. 배추품종은 수호를 이용하였으며 관비횟수는 2회(20일 간격), 3회(15일), 4회(10일), 6회(7일), 관행(추비3회) 등 5처리를 두었으며 기준시비량은 N-P-K=32.0-7.8-19.8kg/10a로 하였으며 관비농도는 EC 1.2 dS/m fh 하였다. 시험은 고령지농업연구소 시험포장에서 6월 하순부터 8월 상순까지 무멀칭 노지재배를 하였다. 관비는 정식후 7일째부터 주었으며 관비량은 1회 구당 20ℓ를 주었다. 시험구배치는 단구제 3반복으로 배치하였다. 생육시기별로 초장, 엽장, 엽폭 모두 관비횟수가 많은 처리에서 생육이 좋았으며 6회 처리가 가장 생육이 좋았다. 주당 외엽수와 내엽수는 관행보다는 관비횟수가 많을수록 많아져 관비 6회에서 주당 69.7매로 가장 많았으며 주중과 구중도 관행에 비해 관수횟수가 많아질수록 높아졌으며 관비 6회에서 주중은 2,439g, 구중은 1,917g 으로 높게 나타나, 고랭지배추 관비횟수는 EC 1.2 dS/m 농도에서 6회를 한 것이 생육이 양호하였다.

• The Korean Journal of Applied Statistics
• /
• v.19 no.1
• /
• pp.1-12
• /
• 2006

The aim of this study is to analyse a survey data on the number of charitable donations using a mixture of two Poisson regression models. The survey was conducted in 2002 by Volunteer 21, an nonprofit organization, based on Koreans, who were older than 20. The mixture of two Poisson distributions is used to model the number of donations based on the empirical distribution of the data. The mixture of two Poisson distributions implies the whole population is subdivided into two groups, one with lesser number of donations and the other with larger number of donations. We fit the mixture of Poisson regression models on the number of donations to identify significant covariates. The expectation-maximization algorithm is employed to estimate the parameters. We computed 95% bootstrap confidence interval based on bias-corrected and accelerated method and used then for selecting significant explanatory variables. As a result, the income variable with four categories and the volunteering variable (1: experience of volunteering, 0: otherwise) turned out to be significant with the positive regression coefficients both in the lesser and the larger donation groups. However, the regression coefficients in the lesser donation group were larger than those in larger donation group.

• The Journal of Korean Academy of Prosthodontics
• /
• v.60 no.3
• /
• pp.239-245
• /
• 2022

Purpose. The purpose of this study was to analyze the frequency and duration of adjustments after delivery of complete denture according to age, sex, arch with complete denture, insurance coverage of a denture, type of antagonist, the experience of wearing denture, the period of edentulism, and the type of denture base. Materials and methods. For 5 years, medical records of patients aged 65 or older who had treated full dentures were assessed for the frequency and duration of follow-up visits after complete denture delivery. Statistical analysis was performed at the 5% level of significance to analyze the correlation between the frequency and duration of follow-up according to sex, insurance coverage, arch with the complete denture, type of denture base, type of antagonist, experience of wearing a denture, age, and healing period. Results. 247 complete dentures were included in this study. The median frequency of follow-up visits was 3, and the median duration of follow-up was 36 days. Lower dentures had significantly higher frequency of follow-up visits than upper dentures (P = .036). According to the type of antagonist, dentures opposing a complete denture had a significantly higher frequency of follow-up visits than dentures opposing a removable partial denture (P = .016). There was no statistically significant difference in the frequency and duration of adjustments after delivery of complete denture by age, sex, insurance coverage, healing period, the experience of wearing a denture, and type of denture base. Conclusion. Within the limitations of the present study, lower complete dentures or dentures opposing a complete denture had an increased frequency of follow-up visits.

• Journal of the Korean Data and Information Science Society
• /
• v.9 no.2
• /
• pp.311-322
• /
• 1998

In this paper the problem of modeling count data where the observation period is determined by the survival time of the individual under study is considered. We assume marginal frailty model in the counts. We assume that the death times follow a Weibull distribution with a rate that depends on some covariates. For the counts, given a frailty, a Poisson process is assumed with the intensity depending on time and the covariates. A gamma model is assumed for the frailty. Maximum likelihood estimators of the model parameters are obtained. The model is applied to data set of patients with breast cancer who received a bone marrow transplant. A model for the time to death and the number of supportive transfusions a patient received is constructed and consequences of the model are examined.

• Journal of the Korean Society for information Management
• /
• v.27 no.1
• /
• pp.103-118
• /
• 2010

Recently, the valuation of patented technology has been greatly emphasized, and patent citation has been accepted as a very useful index of this technology. In this study, we performed correlation analyses between the patent citation counts and 17 explanatory variables of morphological, technological, and conceptual factors with a test dataset of U.S. patents in five subject fields. Seven variables having 5% or more standardized variances($r^2$) with patent citation counts were identified; number of pages, number of claims, reference-average-citation rate, patent increase/decrease rate, strength of bibliographic coupling, co-citation counts and document similarity. The result of the ANOVA test shows that the mean values of these variables vary among most subject fields.