• Journal of Forest and Environmental Science
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• v.31 no.2
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• pp.126-135
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• 2015

This study was conducted to evaluate the ecological characteristics of forest cover types which were classified by cluster analysis in the natural forest of Sobaeksan on the basis of the vegetation data from the point-quarter sampling method. Recognized forest cover types were 1) Mixed mesophytic forest, 2) Taxus cuspidata forest, 3) Fraxinus rhynchophylla-Quercus mongolica forest, 4) Betula ermanii forest, 5) Pinus densiflora forest, 6) Quercus mongolica mixed forest, and 7) Quercus mongolica pure forest. For those of classified types, the species composition was expressed by importance value (IV) to describe the community floristically. The species diversity was quantified using the Shannon's diversity index. The results showed that the forest cover types were characteristically different from one another in growing species and compositional rates, depending upon the type which was formed by a number of similar vegetational sample points. Species diversity indices (H') of total and overstory both were the highest in the mixed mesophytic forest (3.530 and 2.880, respectively), and lowest in the Q. mongolica pure forest (2.122 and 0.000, respectively) with only one canopy species. The highest species diversity in the mixed mesophytic forest may due to the relatively high species richness and evenness in the forest cover types. The description on ecological characteristics were suggested to understand the formation and development of forest cover types in this study area.

• The Korean Journal of Applied Statistics
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• v.23 no.5
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• pp.891-908
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• 2010

In Korea, the small area estimation method is currently unpopular in generating o cial statistics. Because it may be difficult to determine the reliability for small area estimation, although small area estimation ha a sufficiently good advantage to generate small area statistics for Korea. This paper inspects the method of making small area unemployment through the small area estimation method. To estimate small area unemployment we used an EBLUP-type estimator based on a logistic linear mixed model. To evaluate the EBLUP-type estimator we accomplished the real data analysis and simulation experiment from the population and housing census data. In addition, small area estimates are compared to large sample survey estimates. We found the provided method in this paper is highly recommendable to generate small area unemployment as the official statistics.

• Macromolecular Research
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• v.17 no.10
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• pp.807-812
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• 2009

In this work, we focus on the tumbling dynamics of rod-like and semi-flexible polymers in mixed flows, which vary from simple shear to pure rotation. By employing a bead-rod model, the tumbling pathways and periods are examined with a focus on the angular distribution of their orientation. Under the mixed flows, the tumbling dynamics agreed well with earlier studies and confirmed the predicted scaling laws. We found that the angular distribution deviates from that of shear flow as the flow type approaches pure rotation. Finally, we investigated the angular distribution of $\lambda$-DNA in a shear flow and found that the present numerical simulations were in quantitative agreement with the previous experimental data.

• The Korean Journal of Applied Statistics
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• v.28 no.2
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• pp.221-230
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• 2015

Traditionally, sib-pair linkage analysis with repeated measures has employed linear mixed models, but it suffers from the lack of power to find genetic marker loci associated with a phenotype of interest. In this paper, we use a gamma mixed model to improve sib-pair linkage analysis and compare it with a linear mixed model in terms of power and Type I error. We illustrate that the use of gamma mixed model can achieve higher power than linear mixed model with Genetic Analysis Workshop 13 data.

• Journal of Broadcast Engineering
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• v.11 no.4 s.33
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• pp.441-447
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• 2006

See-through HMD type 3D display can provide an advantage of us seeing virtual 3D data used stereoscopic display simultaneously with real object(MR-Mixed Reality). But, when user sees stereoscopic display for a long time, not only eye fatigue phenomenon happens but also de-focus phenomenon of data happens by fixed focal point of virtual data. Dissatisfaction of focus adjustment of eye can be considered as the important reason of this phenomenon. In this paper, We proposed an application of multi-focus in see-through HMD as a solution of this problem. As a result, we confirmed that the focus adjustment coincide between the object of real world and the virtual data by multi-focus in monocular condition.

• Journal of the Korean Institute of Rural Architecture
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• v.23 no.1
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• pp.1-8
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• 2021

In this study, a real-sized experimental equipment (pilot plant) was built at the site based on the preliminary research data to develop a movable separator for the mixed construction waste that can be implemented in agricultural areas to review its feasibility through the evaluation of its separation efficiency by waste types. The final construction of the movable separator and experimental results of the separation efficiency are summarized as follows. 1) The separation performance according to the blade type was the best for the combustible wastes either with 26 numbers of L-type blades and 32 numbers of pin type blades. As far as combination of blade types, when the L-type and pin-type were combined, the best separation efficiency was achieved. 2) The separation efficiency for waste wood by the conveyor type and angle of inclination (slope) of the trommel was the best when the conveyor had ribs of seagull shape with the angle of inclination 45°. 3) The separation efficiencies by process showed that 65.9% was separated as inorganic demolition wastes, 18.2% as waste woods, and 16.0% as combustible wastes at conveyor speed of 2-3 rpm, and the error rate was the least from the waste types generated in the dismantle site.

• Journal of KIBIM
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• v.10 no.1
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• pp.23-29
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• 2020

The vacant houses commonly observed in urban aging are considered to be representative signs of urban decline. Vacant houses are themselves vulnerable to security, and in particular, they are exposed to disasters due to poor management, which can accelerate the decline of the area. This study is to classify the area and analyze the causes and characteristics of the occurrence of vacant houses by type based on the data through the survey on the vacant houses in Incheon. This research analyze vacant house data survey so to characterized and categorized types of vacant houses. The criteria of vacant houses analysis are population density, population growth, aging extent. In conclusion there are four types of region in Incheon area according to housing types, hazard classes, building age and building areas. Type A is inner city, type B is mixed, type C is expandable and type D is unsular types.

• Korean Journal of Human Ecology
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• v.20 no.2
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• pp.353-364
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• 2011

The purpose of this study was to examine different child care curricula according to teacher's teaching method types. The subjects of the study were three hundred and fifty-six teachers, who were divided into four groups according to their teaching method: mixed method(type A), child oriented method(type B), teacher oriented method(type C), and beliefless method(type D). The data on the duration of free play and outdoor play time, activities frequently practiced in class, and outside one the playground were collected. The dimensions of child care programs were measured using Moore(1994)'s "The Early Childhood Dimensions of Education Rating Scale". The results of this study were as follows: first, teachers who used child oriented teaching methods gave more free play time than teachers using teacher oriented or mixed teaching methods. Second, teachers using teacher oriented methods showed the closeness and teachers using child oriented methods showed the openness in child care programs. Last, the activities teachers thought were the most important differed according to the teachers' methods even though in actual practice, there was no difference shown.

• Journal of Environmental Science International
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• v.31 no.9
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• pp.735-741
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• 2022

Global warming affects forests and their ecology. Diversity in the forest is a buffer that reduces the damage due to global warming. Mixed forests are ecologically more valuable as versatile habitats and are effective in preventing landslides. In Korea, most forests were created by simple afforestation with trees of evergreen species. Typically, evergreen trees are shallow-rooted, and deciduous trees are deep-rooted. Mixed forest tree roots grip the soil effectively, which reduces the occurrence of landslides. Therefore, improving the distribution of tree types is essential to reduce damage due to global warming. For this improvement, the investigation of tree types of the forest is needed. However, determining the tree type distribution of forests that are spread over wide areas is labor-intensive and time-consuming. This study suggests effective methods for determining the distribution of tree types in a forest that is spread across a relatively wide area. Using normalized difference vegetation index and RGB images from unmanned aerial vehicles, each evergreen and deciduous tree, and grassland area can be distinguished. The distinguished image determines the distribution of tree type. This method is effective compared to directly determining the tree type distribution in the forest by the use of manpower. The data from these methods could be applied to plan a mixed forest or to prepare for future damage due to global warming.

• Journal of the Korean Operations Research and Management Science Society
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• v.41 no.3
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• pp.23-36
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• 2016

We consider a model that minimizes the total cost incurred by assigning available weapons to existing targets in order to reduce enemy threats, which is called the weapon target assignment problem (WTAP). This study addresses the stochastic versions of WTAP, in which data, such as the probability of destroying a target, are given randomly (i.e., data are identified with certain probability distributions). For each type of random data or parameter, we provide a stochastic optimization model on the basis of the expected value or scenario enumeration. In particular, when the probabilities of destroying targets depending on weapons are stochastic, we present a stochastic programming formulation with a simple recourse. We show that the stochastic model can be transformed into a deterministic equivalent mixed integer programming model under a certain discrete probability distribution of randomness. We solve the stochastic model to obtain an optimal solution via the mixed integer programming model and compare this solution with that of the deterministic model.