• Korean Journal of Environment and Ecology
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• v.15 no.4
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• pp.394-400
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• 2002

A mixed forest community of broad-leaved trees in Guryongsan area was studied to determine the adequate number of plots of tree and shrub strata for investigating forest community structure. Fifteen 10m$\times$10m plots were set up in the tree stratum and fifteen 5m$\times$5m plots were set up in the shrub stratum. Species-area curves and performance curves were made from vegetation analysis of the plots. In tree stratum, the minimum number of plots where a given percentage increase in number of plots produced less than the same percentage in number of species was five. In tree stratum, minimum number of plots where a given percentage increase in nuts her of plots produced less than the half of the percentage increase in number of species was ten. In tree stratum, minimum number of plots where the dominant species was distinguished from the subdominant species was four In tree stratum. minimum number of plots where the subdominant species were distinguished from each other was eight. In tree stratum, the difference of species diversity(H') between seven or more plots and total fifteen plots was less than 0.05 Similarity index was more than 80% between aye or more plots and total fifteen plots, and more than 90% between nine or more plots and total fifteen plots. In shrub stratum, the minimum number of plots where a given percentage increase in number of plots produced less than the same percentage in number of species was five . In shrub stratum, the minimum number of plots where a given percentage increase in number of plots produced less than the half of the percentage increase in number of species was twelve. In shrub stratum. minimum number of plots where the dominant species was distinguished from the subdominant species was four. In shrub stratum, the minimum number of plots where the subdominant species were distinguished from each other was thirteen. In shrub stratum, the difference of species diversity(H') between six or more plots and total fifteen plots was less than 0.05. Similarity index was more than 80% between five or more plots and total fifteen plots, and more than 90% between nine or more plots and total fifteen plots. It may be given as a conclusion that adequate number of 10m$\times$10m plots for the tree stratnm was about 5 in general acse and 10 in case of requiring more accuracy, and that the adequate number of 5m$\times$5m plots for ahrub stratum was about 5 in general case and 13 in case of requiring more accuracy.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.503-508
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• 2003

In this study, we peformed ahead a field geological investigation, boring investigation for slope stability analysis in large scale slope failure area. But the geological stratum was not clearly grasped, because ground was very disturbed by large scale Granite intrusion. Furthermore, the existing test data was not pertinent to the large scale Granite intrusion site like here. Therefore, various kind of field test were performed to grasp clearly for geological stratum. And the results of back analysis, various kind tests used to slope stability analysis.

• Asian Journal of Turfgrass Science
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• v.9 no.2
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• pp.131-136
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• 1995

The herb, shrub, understory and canopy strata, which arbitrarily delineated by size classes, were sampled separately. The former one were sampled by the pin-point quadrat method. And remaining three by size quadrats, diversity (H= =$\Sigma$ Pi log Pi) of of each stratum was estimated for each set of census data. Species diversity within a stratum was independent of sample plot size above a minimum cumulative area. Diversity based on plotless and plot samples could he determined by the same equation, and by pooling the data needed to estimate diversity of each stratum.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.13 no.21
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• pp.81-90
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• 1990

In stratified random sampling a simple random sample must be taken in each stratum to reduce the maximum gain in precision given the minimum cost. The purpose of this paper is to deal with the propertics of the estimates and variances and obtain the economic design of stratified random sampling through the optimum allocation of the sample sizes. In addition, the between stratum variation and the within stratum variation is stratifying the population are described.

• Imaging Science in Dentistry
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• v.31 no.4
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• pp.221-225
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• 2001

Purpose: To observe the relationship of bilaminar zone of temporomandibular joint retrodiscal tissues to the disc condition. Materials and Methods : The upper and lower stratum of bilaminar zone were identified on magnetic resonance open mouth images of 148 joints from 74 patients with disc displacements. Results: Both strata were identifiable in 105 joints which had disc displacement with reduction. Lower stratum was not identifiable in 35 joints which had disc displacement without reduction but 12 of 35 had hyalinized posterior attachment where the disc was. The 8 joints which had partial disc displacement without reduction showed identifiable lower stratum at the reducing site which was medial. Conclusion: Disruption or no identification of lower stratum which corresponds to the condylar portion of posterior attachment may be the sign of disc displacement without reduction.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1162-1164
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• 2000

Stratum Axial Type BLDC Motor has remarkable efficiency owing to outstanding characteristics of speed and torque as well as its small size. In this paper 2-Degree of Freedom PI (TDOF PI) control method is presented in order to improve the efficiency of Stratum Axial Type BLDC Motor and the simulation proves that the separate control for speed characteristic from answering characteristic of load torque particularly allows the construction of superior control system to PI control system. These results are significant in that the improved Stratum Axial Type BLDC Motor enables the production of much smaller, lighter, and noiseless electric home appliances such as air-conditioner and refrigerator.

• The Korean Journal of Applied Statistics
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• v.33 no.4
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• pp.409-420
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• 2020

In business survey, modified cut-off sampling is commonly used to greatly increase the accuracy of the estimation while reducing the number of samples. However, non-response rate of take-all stratum has increased significantly and the sample substitution is not possible because the non-response in the take-all stratum affects the accuracy of the estimation. It is important to adjust the bias appropriately if non-response is affected by the variable of interest. In this study, a bias adjusted estimation is proposed as an appropriate method to deal with a non-response in the take-all stratum. In particular, the estimator proposed by Chung and Shin (2020) was applied to the bias adjustment for the take-all stratum; therefore, we suggest a new method to adjust properly for the take-all stratum. The superiority of the proposed estimator was examined through simulation studies and confirmed through actual data analysis.

• Tunnel and Underground Space
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• v.28 no.2
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• pp.142-155
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• 2018

The ${\bigcirc}{\bigcirc}$ mine has irregularly developed stratum around the ore body. The purpose of this study is to array irregular stratum thickness systematically for effective roof bolting and to implement a supporting system corresponding to it. The number of 81 cases combined with stratum thicknesses was limited to 9 cases by robust design. For each case, the load height which can act as a roof load was determined by the characteristics of stratum and RMR. The load range due to the load height is calculated assuming block shaped and arch shape. The support load of the roof bolt was considered as the average load of the two methods. Numerical analysis results of the support design showed that the cable bolt was more effective for the roof supporting fully grouted than the anchoring type. As a result of the construction, it was possible to control the roof, but all of the roof was gradually sinking downward due to the deformation of the side wall of the mine tunnel.

• The Journal of the Korea Contents Association
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• v.17 no.12
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• pp.426-436
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• 2017

The purpose of this study was to determine the moderating effect of subjective health state of elder who lives alone on the influence of those people's stratum consciousness on their depression. For this purpose, the study utilized the 5th version of Korea Longitudinal Study on Aging 2014 and analyzed data concerning 774 elder who lives alone. The findings of this study can be summarized as follows. First, the higher elder who lives alone were in subjective stratum consciousness, the lower they were in depression. Second, elder who lives alone were lower in depression when perceiving they were higher in health state. Third, the elder who lives alone were lower in depression when their perceived subjective health state was higher even if they were lower in stratum consciousness. All these findings clearly indicate that the stratum consciousness and depression of elder who lives alone are moderated by their perceived health state of their own. Lastly, the implications, limitations, and suggestion for further research were discussed.

• The Journal of Korean Medicine
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• v.26 no.3 s.63
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• pp.13-26
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• 2005

Objectives : Applying herbal-acupuncture using Ursi Fet into Zusanli (UZ) on to the atopic dermatitis (AD) in mice to study changes in external dermal formation, change of leukocytes in vasculature, change of lipid formation in stratum corneum and distribution of ceramide. This study was done through forcing an injury to the mice's back skin which damages the lipid protection formation in the stratum corneum. Methods : The AD which was caused intentionally using the external application on the mice's back skin was treated with VB; the change of leukocytes in the vasculature was identified through optima 5.2 and Student's t-test and the results were made into a dermal formation graph. Results : After dispensing UZ into the AD, the dermal injury decreased. The recovery of the lipid protection formation which includes lipid and ceramide in the stratum comeum (for suppressing acute inflammation due to factors such as PKC, $TNF-\alpha,\;IL-1\beta$, which controlled the secretion of the relating inflammatory cytokine) also went on to show a decrease of both angiogenesis and degranulated mast cells. In addition, the decrease of epithelial injury also caused the growth of cells to decrease in the stratum basale and cytoclasis. In the vasculature, the leukocytes were also decreased na this could relate to a decrease in AD. Conclusions : UZ has an effect on AD by suppressing dermal injury through the recovery of the lipid protection formation in the stratum corneum.