• Journal of architectural history
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• v.33 no.2
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• pp.7-15
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• 2024

The composition of the upper structure, which can be found in the 3-Dori type buildings in Yang-dong Village, varies significantly from time to time. The upper structure of the Gwan-ga-jeong, known as a house in the mid-Joseon Dynasty, consists of a basic 3-Dori type structure in which a beam is placed under 3-Dori and supported with two flat columns. On the other hand, the upper structure of I-hyang-jeong historic house, built in the 17th century, is different in that it has a stud between the two flat columns. The upper structure of Sa-ho-dang historic house, a 19th-century building is different from the upper structure of the buildings of the previous period in that three flat columns were used. As such, the difference in the composition method of the upper structure according to the construction period is closely related to the introduction of the Toi-maru, which is mainly explained by the boundary space. In addition, it can be expected that the introduction of the Toi-maru originated from the influence of the change in the plan. This study was conducted to examine the correlation between the plan and the composition of the boundary space through various typology of the 3-Dori upper structure distributed intensively in Yang-dong Village.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.3
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• pp.258-266
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• 2000

Experimental investigation and cycle simulation of a capacity modulation of a heat pump system using a hydrofluorocarbon (HFC) refrigerant mixture, R32/134a as an alternative to R22, have been done. In the cycle simulation, the refrigeration system was operated by assigning the temperatures of the external heat transfer fluids with the heat exchangers generalized by an average effective temperature difference. Heating capacity, cooling capacity, and coefficient of performance (COP) of the system were investigated at several operating conditions. Experimental apparatus which had a refrigeration part and a composition changing part was built, and the performance of the heat pump system filled with R32/134a mixture was investigated. A gas-liquid separator was used in the experiment to change the composition by collecting the vapor and the liquid Phase separately, The mass fraction of the charged refrigerant in the heat pump system was 40/60 and 70/30 by weight percentage. The composition of the refrigerant with initial composition of 40/60 varied from 29/71 to 41/59 in the refrigeration cycle. For the refrigerant with initial composition of 70/30, the composition varied from 65/35 to 75/25.

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.11a
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• pp.26-26
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• 2002

• Journal of the Korean Society for Library and Information Science
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• v.39 no.3
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• pp.225-244
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• 2005

This study aims to find the direction of subject-divisional plan and the change of composition factors in university Library. To confront new information environment, change of service providing environment, academic characteristics of universities. and users' information needs, the collection and service of university libraries are needed to be restructured based on subject-divisional plan. To adopt subject divisional plan effectively. it is necessary to recognize necessity and reasonability of subject - divisional plan by analyzing a change of physical, intellectual, human, and user factors in the libraries from the aspect of subject-divisional plan. That is, the collection and service of university libraries should be reorganized according to the subjects along with such changes as below. First, people came to consider convenience of space and path of building inside more than past. Second, collection becomes constructed and materials are located based on effectiveness rather than logicality. Third, subject oriented service of library became active through developing the subject abilities of librarians. Fourth, users have tendency to visit libraries lot a special subject matter.

• Korean Journal of Environmental Agriculture
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• v.38 no.3
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• pp.139-144
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• 2019

BACKGROUND: Epigeic arthropods participate in ecological functions as predators, decomposers and herbivores. The purpose of this study was to investigate the responses of some dominant arthropods in rice fields to different forms of agricultural land management. METHODS AND RESULTS: The abundance of microarthropods was compared between rice fields and uplands in the non-growing season. Collembola, Oribatida and Mesostigmata were more abundant in the upland fields than in the paddy fields. The community composition and diversity of epigeic arthropods were compared between fallow and rice fields. The total abundance and species richness of spiders and ground beetles were not significantly different in the two types of agricultural fields. The abundance of Arctosa kwangreungensis was greater in fallow fields than in cultivated fields. The community structure of arthropods was compared between paddy fields with and without barley. The cropping system altered the community composition of spiders but not their biodiversity. Barley cultivation increased the abundance of ground beetles but decreased that of spiders. We suggest that this contrast was partly due to the availability of plants that provided shelter and food for ground beetles. CONCLUSION: These results show that soil use intensity and cropping system alter the community composition of epigeic spiders and ground beetles. This could result in ecosystem-level alterations with respect to the control of pests and weeds. Our results also suggest that biodiversity of ground-dwelling arthropods may not increase during short fallow periods.

• Journal of the Korean Institute of Rural Architecture
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• v.22 no.4
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• pp.25-34
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• 2020

The study of the modern age period folk house is still insufficient in the Korean folk house study. The study subject had a tendency towards mainly on the plan in the field of the traditional folk house which had been studied relatively lively. We were going to grasp the formation and the actual situation of the folk house in this paper targeting at Yeosu city where the folk houses were left relatively a lot. Specifically, we examined it how the composition and dimensions of timber framework changed according to period. The division of period from before 1910 to the 1960s classified it at 4 periods on the basis of the sociocultural change. However, as a result of investigation analysis, the change of the composition and dimensions of timber framework was classified at 3 periods not 4 periods. The division of 3 periods is "traditional era", "modern age 1", and "modern age 2" not "traditional era", "modern age", and "contemporary age". The folk house group came as a common name for folk house without doing the division of period until now. There is a meaning in that this paper subdivided the period of the folk house group by the change of the timber framework technology. The timber framework is the effective index to investigate the actual condition because the change is difficult after building. Therefore, we examined it including the dimensions as well as the composition of timber framework in this paper comprehensively and systematically.

• Journal of Korean Academy of Oral Health
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• v.43 no.3
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• pp.118-123
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• 2019

Objectives: The purpose of this study was to investigate changes in the composition of artificial cariogenic biofilms using a Streptococcus mutans biofilm model over a period of time. Methods: We analyzed the dry weight, colony forming unit (CFU) number, extracellular polysaccharide (EPS) biovolume, and acid production rate of S. mutans biofilms formed on saliva-coated hydroxyapatite discs after 26 h, 50 h, 74 h, 98 h, 171 h, and 195 h. In addition, we performed a laser scanning confocal fluorescence microscopy to determine the bacterial volume, EPS biovolume, and biofilm thickness. We calculated the biofilm density using dry weight and EPS biovolume. Results: Over a period of time, there was no change in the CFU number and acid production rate of S. mutans biofilms, but there was an increase in the dry weight and EPS biovolume of S. mutans biofilms. The bacterial volume, EPS biovolume, and biofilm thickness only increased in the 50-h-old biofilm; however, no change was observed in 50-195-h-old biofilms. In addition, an increase in the biofilm density was observed over time. Conclusions: These results suggest that the acid production ability of cariogenic biofilms does not change, but the biofilm density increases over time. However, due to scientific information, further research needs to be conducted in the field of dentistry to get further insights on the progression of cariogenic biofilms over time.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.6
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• pp.707-712
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• 2005

PRAM (Phase change random access memory) is one of the most promising candidates for next generation Non-volatile Memories. The Phase change materials have been researched in the field of optical data storage media. Among the phase change materials. $Ge_2Sb_2Te_5$ is very well known for its high optical contrast in the state of amorphous and crystalline. However the characteristics required in solid state memory are quite different from optical ones. In this study. the structural Properties of GeSbTe thin films with composition were investigated for PRAM. The 100-nm thick $Ge_2Sb_2Te_5$ and $Sb_2Te_3$ films were deposited on $SiO_2/Si$ substrates by RF sputtering system. In order to characterize the crystal structure and morphology of these films. x-ray diffraction (XRD). atomic force microscopy (AFM), differential scanning calorimetry (DSC) and 4-point measurement analysis were performed. XRD and DSC analysis result of GST thin films indicated that the crystallization of $Se_2Sb_2Te_5$ films start at about $180^{\circ}C$ and $Sb_2Te_3$ films Start at about $125^{\circ}C$.

• Journal of Korean Society of Rural Planning
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• v.24 no.2
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• pp.69-78
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• 2018

The purpose of this study is on identifying vegetation change through monitoring representative complementary village forests according to different management. For this, two of complementary village forests around Mai mountain which many ones remain were selected. Those are complementary village forests of Seochon and Wonyeonjang. Seochon forest is a representative one which is managed naturally and Wonyeonjang one is a representative one which is managed artificially. The field survey for monitoring was preformed in 2002 and 2007, 2016. D(Dominant degree) and S(Sociability degree) were measured by Brown-Blanquet's method in field survey. Through the analysis and review of survey data, the change of species richness, appearing species characteristics, species composition and layer structure etc. according to different management was monitored. As a result, it can be seen that natural succession has increased species diversity, improved vegetation structure and circulation of complementary village forest. On the other hand, excessive anthropomorphic management was found to be detrimental to the health of the forests and to the vegetation structure and species composition. And it was found that excessive management threaten sustainability and periodical proper management is necessary. Through this review, the useful management direction of complementary village forests was suggested.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.203-204
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• 2005

PRAM (Phase change Random Access Memory) is one of the most promising candidates for next generation Non-volatile Memories. The Phase change material has been researched in the field of optical data storage media. Among the phase change materials $Ge_2Sb_2Te_5$(GST) is very well known for its high optical contrast in the state of amorphous and crystalline. However, the characteristics required in solid state memory are quite different from optical ones. In this study, the structural properties of GST thin films with composition were investigated for PRAM. The 100-nm thick GeTe and $Sb_2Te_3$ films were deposited on $SiO_2$/Si substrates by RF sputtering system. In order to characterize the crystal structure and morphology of these films, we performed x-ray diffraction (XRD) and atomic force microscopy (AFM).