• Structural Engineering and Mechanics
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• v.29 no.5
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• pp.531-550
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• 2008

This paper adopts the numerical assembly method (NAM) to determine the exact solutions of natural frequencies and mode shapes of a multi-span and multi-step beam carrying a number of various concentrated elements including point masses, rotary inertias, linear springs, rotational springs and springmass systems. First, the coefficient matrix for an intermediate station with various concentrated elements, cross-section change and/or pinned support and the ones for the left-end and right-end supports of a beam are derived. Next, the overall coefficient matrix for the entire beam is obtained using the numerical assembly technique of the conventional finite element method (FEM). Finally, the exact solutions for the natural frequencies of the vibrating system are determined by equating the determinant of the last overall coefficient matrix to zero and the associated mode shapes are obtained by substituting the corresponding values of integration constants into the associated eigenfunctions.

• Electronics and Telecommunications Trends
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• v.39 no.1
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• pp.95-105
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• 2024

In natural language processing, large language models such as GPT-4 have recently been in the spotlight. The performance of natural language processing has advanced dramatically driven by an increase in the number of model parameters related to the number of acceptable input tokens and model size. Research on multimodal models that can simultaneously process natural language and image data is being actively conducted. Moreover, natural-language and image-based reasoning capabilities of large language models is being explored in robot artificial intelligence technology. We discuss research and related patent trends in robot task planning and code generation for robot control using large language models.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.1
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• pp.41-51
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• 2001

'The Ecological Forest' in Youido Park was intended to be an artificial forest in urban center, following the form of natural forests in central Korea. This study was to investigate the planting plan and the vegetation change of 'the Ecological Forest' and to compare it with natural forests of similar plant composition. The natural forests had slopes between $12^{\circ}$ and $21^{\circ}$, whereas 'the Ecological Forest' had slopes between $2^{\circ}$ and $6^{\circ}$. It was unlikely that the slope condition was adequate to show 'toposequence succession' at 'the Ecological Forest'. The soil bulk density and soil hardness of 'the Ecological Forest' were higher than those of the natural forests. The soil pH of 'the Ecological Forest' was 7.45, which was greater than that of the natural forests. There were some changes in plant composition and amounts 2 years after the construction : the number of conifers was reduced from 383 to 338 ; the number of deciduous trees was reduced from 4717 to 1158. It was because of the young trees dead in the sub-tree layer. The herbaceous species planted were 14 families, 31 species, which increased to 37 families, 93 species after 2 years. In case of horizontal structure of vegetation, trees and shrubs were distributed evenly in the natural forests, whereas 'the Ecological Forest' showed uneven distribution with higher total density. In case of vertical structure of vegetation, the natural forests had distinctive layers with dominant species distributed in each layers. In 'the Ecological Forest', however, dominant species were only in tree layer. The natural forests had greater average tree height, tree density, however, and basal area than 'the Ecological Forest'. The results showed that there were some differences in the structure between 'the Ecological Forest' and natural forests. The management plan should be applied in order that the natural condition be restored in 'the Ecological Forest' by competition between plant species and natural processes.

• Korean Journal of Environmental Agriculture
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• v.16 no.1
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• pp.44-47
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• 1997

The change in microbial flora has been studied through dwelling house composting by the composter with double layer walls. The results are summarized as followes. 1. Mesophilic bacteria increased and decreased mildly, thermophilic bacteria showed a tendency to decrease except for spring, and the number of mesophilic bacteria and thermophilic bacteria had a tendency to increase and decrease simultaneously. 2. The number of mesophilic actinomycetes were increased at the early stage of compositing in winter, mildly decreased in spring and slightly decreased in summer, and the number of thermophilic actinomycetes were decreased at the early stage of composting. 3. The decrease in the number of mesophilic fungi was observed at the middle stage in summer, but the mild increase was observed in spring and winter. The number of thermophilic fungi was generally decreased. 4. Ammonia oxidizer and nitrite oxidizer were observed in this field composting much more than in the other composting experiments.

• The Journal of Advanced Prosthodontics
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• v.11 no.2
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• pp.75-80
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• 2019

PURPOSE. The purpose of this study is to investigate the effects of aging and various risk factors on the oral environment and to analyze them in 3-dimensions. MATERIALS AND METHODS. A total of 800 patients were enrolled in this study, and subjects were divided into 4 groups by age-under 55, 56 - 65, 66 - 75, and over 76. Based on their most recent visit, the number of crowns, bridges, implants, and the remaining natural teeth were recorded. Smoking habits, along with presence of diabetes and hypertension, were surveyed, as risk factors were also set as a variable. Comparisons among the groups or within the groups were performed by independent t-test, and one-way and two-way ANOVA. Kruskal-Wallis test and Mann-Whitney U test were used for analysis. It was assumed to be statistically significant when P value is below .05. RESULTS. Changes in the number of crowns, bridges, implants, and the remaining natural teeth by age were statistically significant. When we examined the effect of risk factors on the change of variables with age, hypertension was found to affect the number of bridges. Diabetes and smoking were found to affect the number of the remaining natural teeth. The other variables were not statistically significant. CONCLUSION. Aging is considered to be an important variable affecting the change of oral environment. Among the risk factors, the presence of smoking habit and diabetes is thought to have a great influence on the change of the number of the remaining natural teeth.

• Korean journal of applied entomology
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• v.50 no.2
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• pp.83-96
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• 2011

This study was conducted to investigate the influence of natural degrading polymer film covering in rice paddies on the benthic macroinvertebrate community structure in Dangsu-dong, Suwon, Gyeonggi-do from May 2009 to September 2009. We compared 5 treatments: golden apple snail farming (GF), natural degrading polymer film + organic farming (NOF), natural degrading polymer film + chemical farming (NCF), conventional farming (CF), and no fertilization (NF) as the control. The total number of species was highest in NOF followed by GF, NF, NCF, and CF. The total number of individuals was highest in NOF followed by NCF, CF, NF, and GF. The Dominance index (DI) ranged from 0.43 to 0.95. The highest dominance index was in GF followed by NCF, NF=CF, and NOF. The species diversity index (H') for each experimental plot ranged from 0.49 to 2.93. The average species diversity index was highest in NOF followed by NF, GF, CF, and NCF. After the natural degrading polymer film covered the paddies, the benthic macroinvertebrates tended to recover, but leeches and aquatic beetles increased. Mollusca and Annelida, which are sensitive taxa, decreased in both species and individual numbers after the soil was covered with the natural degrading polymer film. The number of species tended to recover. However, the number of individuals continued to decrease.d, especially individuals. Since then, the number of species tended to recover. However, the number of individuals decreased.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.6
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• pp.1056-1060
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• 2011

To summarize and make a reference number of natural materials used to treat diabetic peripheral neuropathy. We surveyed all papers of diabetic peripheral neuropathy studies using natural materials in PubMed as "diabetic peripheral neuropathy AND plant", "diabetic peripheral neuropathy AND herbal", "diabetic peripheral neuropathy AND herb", etc. The number of papers, the formation of experiments, frequency of natural materials studies, and main studies were analyzed. Total 48 studies were finally selected. Of the papers, experiments with rats were the most common. Most studies were about fatty acids or herbal medicines. Rehmannia glutinosa, Cinnamomi Ramulus, Astragali Radix and so on were relatively studied much. This study produced an overview of worldwide natural materials used for diabetic peripheral neuropathy. This result may provide a valuable information of development of Korean herbal medicine used to treat diabetic peripheral neuropathy.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.2
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• pp.364-367
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• 2001

We gamma-irradiated to natural casings from lamb and pork to improve sanitary quality and microbiological shelf stability of sausage stuffed in animal intestine-induced natural casing from lamb and pork. The microbial changes of irradiated casings and the microbial growth of the sausages with gamma-irradiated natural casings were observed. Population of total aerobic bacteria was decreased by gamma irradiation, dependent upon the irradiation dose. The number of microflora in lamb and pork casings was reduced by about 5.5 log cycle at 5 kGy. Population of total aerobic bacteria of sausages stuffed in non-irradiated lamb and pork casing was about 3.6 log CFU/g after just manufacture and was about 7 log after 10 day storage. However, population of total aerobic bacteria of sausages with 3 kGy-irradiated and 5 kGy-irradiated casings was 2.48 and 0.32 log in lamb, and 2.78 and 0.60 log in pork, respectively. Gamma irradiation to animal intestine- induced natural casings was effective and thus, can be used for enhancing shelf life of final products due to reduction of the number of contaminated microflora.

• Journal of the Korean Institute of Landscape Architecture
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• v.15 no.2
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• pp.67-78
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• 1987

This study was executed to measure the user\`s impact natural environment in National Park Campsite. Therefore, we choose Mt. Chiak National Park and the campsite in the district of Temple Ku-Ryong as a model of analysis, which is made by ecological approach, the number of the user has influence on the environment near the campsite. The result are as follows : 1. The more the number of users becomes, the more Na, Ca, Mg ion concentration and pH in the soil increase and the less K ion becomes. 2. Litter and humus depth, litter coverage, herb coverage, soil hardness, the surface of the ground layer and tree species numbers, density and coverage of lower layer shows a sensitive reaction to the number of the users. 3. The research shows that the tolerant trees against campsite impact are Lespedeza maximowiczii, Zanthoxylum schinifolium Staphylea bumalda, Smilax sieboldii, Quercus aliena, Euonymus oxyphyllus, Weigela subsessilis and Securinega suffruticosa, and the sensitive trees are Stephanandra incisa, Rubus trichocarpa, Rubus crataegifolius, Rhododendron mucronulatum, Styrax obassia, Acer palmatum, Lindera obtusiloba, Rhododendron suhlippenbachii, Rhus japonica and Callicarpa japonica. 4. The high density of the users made the simplication of a vegetation structure. So, as the number of the user increase the species showed severe heterogeniety between the heavy-use and nonuse site. 5. As considering the landscape management about campsite and surrounding area on the way of analysis of national landscape aspect and succession sere according to ecological aspect, it may be desirable that Pinus densiflora forest be conserved as Pinus densiflora landscape and mixed forest produce natural scenery with succession sere.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.4 s.247
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• pp.337-342
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• 2006

Natural convection flows in a cubical air-filled cavity that has one pair of opposing faces isothermal at different temperatures, $T_h\;and\;T_c$, respectively, the remaining four faces having a linear variation from $T_c\;to\;T_h$ are numerically simulated by a solution code(PowerCFD) using unstructured cell-centered method. Special attention is paid to three-dimensional flow and thermal characteristics according to the variation of inclination angle $\theta$ of the isothermal faces from horizontal: namely $\theta=0^{\circ},\;15^{\circ},\;30^{\circ},\;45^{\circ},\;50^{\circ},\;60^{\circ},\;75^{\circ}\;and\;90^{\circ}$. Comparisons of the average Nusselt number at the cold face are made with experimental benchmark results found in the literature. It is demonstrated that the average Nusselt number at the cold face has a maximum value around the inclination angle of $50^{\circ}$. It is also found that the code is capable of producing accurately the nature of the laminar convection in a cubical air-filled cavity with differentially heated walls.