• Journal of Periodontal and Implant Science
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• v.35 no.3
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• pp.563-575
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• 2005

The aim of present study is to evaluate the influence of adjacent tooth to the microbiology of clinically healthy implant. Control group included patients who had clinically healthy implant and tooth with healthy $periodontium(PD{\leq}3mm)$, test group was composed of patients who had clinically healthy implant and tooth with periodontal pocket(PD>3mm). The criteria of clinically health implant are no pain or discomfort, the restorative suprastructure provide satisfactory fit and function, and the tissue around the fixtures were firm and probing with standard periodontal probe with a rounded tip 0.5mm in diameter resulted in penetration of no more than 5mm when using a force of 0.5N at any location. 38 patients, partially edentulous subjects with endosseous root-form implants were selected. All subjects were medically healthy and had not taken systemic antibiotics and professional plaque control 3 months before sampling. Number of control group is 25(mean age $52{\pm}13$, 26 teeth, 34 implants) and test group is 13(mean age $60{\pm}13$, 13 teeth, 17 implants). All teeth and implants of each patient were examined probing depth(PD), bleeding on probing(BOP), and plaque index(PI), and samples of subgingival plaque were obtained at each site with sterile curet or fine paper points, then the plaque transferred to PBS. Obtained samples were examined for the presence of P. gingivalis, T. forsythensis, and T. denticola by the polymerase chain reaction(PCR). The relationship among clinical parameters and the colonizations by the 3 bacterial species from natural teeth and implants region were analyzed by student t-test. The results of this study were as follows: 1. PD was different in teeth between 2 groups(p<0.05), but the other parameters were not. 2. Statistically significant difference was not found in clinical parameters of implants between 2 groups. 3. All bacterial prevalences of teeth were higher in test group than in control group, and prevalence of T. forsythensis had statistically significant difference between 2 groups(p<0.05). 4. Prevalences of P. gingivalis and T. forsythensis are higher in test group than control group, and that of T. denticola is higher in control group than in test group. But there were no statistically significant differences between 2 groups. In conclusion, there is no statistically significant difference in prevalence of implant microbiology between 2 groups. But if the number of samples increased, it will be possible to find out statistical significance in prevalence of P. gingivalis. It seems that pocket of adjacent tooth influences prevalence of P. gingivalis. These results mean that improvement of the periodontal condition before implantation is very important.

• Journal of Wetlands Research
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• v.11 no.1
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• pp.115-121
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• 2009

The hybrid constructed wetland(HCW) as tertiary treatment process of a bio industrial wastewater treatment plant was employed to estimate applications for the reuse of final effluent. Raw wastewater was sequently treated through chemical and biological treatment processes and the biologically treated water was flowed into the HCW. The HCW system was composed of two constructed wetlands connected in series; The one is the aerobic constructed wetland with natural air draft system whose driving force for air supply was the difference between the temperature of the air inside the wetland and the ambient air, and the other is the anaerobic/anoxic constructed wetland. Average influent concentrations of BOD, SS, T-N and T-P in the HCW were 53mg/L, 48mg/L, 34mg/L and 3mg/L, respectively. After being treated at HCW, final effluent concentrations of BOD, SS, T-N and T-P were 2.3mg/L, 1.2mg/L, 7.95mg/L and 0.83mg/L, respectively. Referring to a reuse standard for a sewage wastewater, final effluent could sufficiently be reuse as landscaping, washing or agriculture water. HCW system with the aerobic/anaerobic combined constructed wetland could be achieved a high removal efficiency because each constructed wetland was functionalized to be removed efficiently organics, nitrogen and phosphorus. HCW system could be estimated to be successful application as tertiary treatment process of a various industrial and municipal wastewater.

• Korean Journal of Food Science and Technology
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• v.35 no.4
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• pp.726-732
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• 2003

The crude extracts from Rhus javanica Linne showed comparatively strong antioxidative activity in test oils. Antioxidative components were isolated and identified by column chromatography, thin layer chromatography, UV, and NMR. These antioxidative components were added to several oils to compare antioxidative activity with several commercial antioxidants, such as BHA, BHT, and tocopherol. After the sixth column chromatography, one fraction (R-18-9-3-2-4-2) was separated from chloroform layer of Rhus javanica Linne. The R-18-9-3-2-4-2 fraction was identified as methyl gallate by $^1H-NMR$ and $^{13}C-NMR$ and confirmed with methyl gallate standard as authentic. The R18-9-3-2-4-2 fraction from chloroform layer of Rhus javanica Linne showed stronger activity than that of the ${\alpha}-,\;{\delta}-tocopherol$, BHT, and BHA at the same concentration.

• Korean Journal of Food Science and Technology
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• v.11 no.3
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• pp.147-152
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• 1979

Nitrite, one of the precursors of dimethylnitrosamine, distributes widely in natural foods and is also used as a color fixing agent in meat products. This experiment was carried out to determine the contents of nitrite and nitrate of Korean foods and suman saliva. Nitrite content was measured by use of the diazotization-coupling reaction, while cadmium reduction method by use of metallic cadmium was applied to determine nitrate. The objects are about 150 of female students who are $19{\sim}22$ years old ands standard analytical values of nitrate contents of $10{\sim}20$ samples produced in various places. The results showed that contents of nitrite and nitrate of Korean foods and saliva were relatively high levels.

• Korean Journal of Construction Engineering and Management
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• v.16 no.6
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• pp.136-143
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• 2015

Snow-melting system has been applied not only to roads for car traffic but also to pavement for the pedestrians safety reason in some of the developed countries such as USA and Canada based on countermeasures against Natural Disasters Act revised in 2000. Even though this system was introduced in korea in 2006 and has been partly applied to car traffic roads, there is few places that the system has been applied. Therefore, in this research a snow-melting system with a block-type to cover a pavement that efficiently transfers heat form heat rays to the top of a pavement and protects the heat rays. A quality check showed that compression and bending strength was improved approximately 5 times stronger and 7 to 10 times more absorption rate than the KS(Korea Industrial Standard) requirement. Moreover, only 10 minute was required to increase temperature above zero with a block-type snow-melting system whereas approximately 180 minute was spent with the existing system. This research is expected to contribute to environmental issues and reduce accidents on a slippery road.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.190-196
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• 2007

As the number of aged-housing has been rapidly increased, many kinds of defects and problems such as degeneration of housing environment, structural performance, and equipment performance have been appeared. The reconstruction as the way to improve the aged-housing has been used mostly because the legal process of the reconstruction is relatively easy. On the other hand, it has caused problems such as the lack of natural aggregates, the environmental damages owing to construction wastes, the loss of national resources, and the lack of the housing for rent nearby the reconstruction area. This problems limit active tying into the reconstruction business at present in the industrial and political perspective. In this context, it is necessary to revitalize the remodeling rather than the reconstruction. In order to reach this objective, this research aims at identifying the user-oriented performance for the housing and deducing the core technology. It is expected that the result of this research can contribute to more revitalize the remodeling as tying researches in terms of design, structure, equipment, and construction.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.428-436
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• 2012

This study aimed to develop the multi-span plastic greenhouse which is suitable for tomato cultivation and is safe against climatic disasters such as typhoon or heavy snow. The width and heights of eaves and ridge of newly developed tomato greenhouse are 7, 4.5 and 6.5 m, respectively. The width is the same but the eaves and ridge heights are 1.8 and 2 m higher than conventional 1-2 W greenhouses, respectively. Cross beam has been designed as a truss structure so it can sustain loads of tomato and equipment. Tomato greenhouse has been designed according to climatic disaster preventing design standard maintaining the high height. In other words, the material dimensions and interval of materials including column and rafter have been set to stand against $40m{\cdot}s^{-1}$ of wind and 40 cm of snow. Tomato greenhouse has been equipped with rack-pinion type roof vents which have been used in glass greenhouse in order to prevent excessive rise in air temperature. This vent type is different from that of 1-2 W type greenhouse which is made by rolling up and down the vinyl at upper part of column. Roof vents are installed at ridge, and thus external air inflow and natural ventilation are maximized. As the height increases, heating cost increase as well and, therefore, tomato greenhouse has been equipped with multi-layered thermal curtain, of which thermo-keeping is excellent, to prevent heat from escaping.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.6
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• pp.97-104
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• 2018

In recent years, more than 5,000 tons of sargassum honeri have been infested in the southern coast and the coast of Jeju Island, causing serious damage to the farms and fisheries, and environmental problems. The alginate contained in the sargassum honeri is a natural polymeric substance mainly used for medicines and foods. However, since there is no way to utilize it in large quantities, a study was carried out to utilize bio polymer obtained from sargassum honeri in producing polymer mortar for repairing deteriorated infrastructures. From the tests of setting time, it was found that the L0BP12 mixture containing 12% of bio polymer increased the setting time by 20% as compared with the L12BP0 mixture using only synthetic polymer. From the tests of water absorbtion, the LOBP12 combination decreased by 0.36% compared to Plain-URHC using ultra rapid hardening cement. This indicated that the watertightness of the mortar was increased by the incorporation of the bio polymer. In the compressive and flexural strength tests, the strength decreased as the amount of bio polymer increased. The incorporation rate of the maximum bio polymer satisfying the KS F 4042 standard was determined to be 12%. In addition, the bond strength of the mortar produced with biopolymer was higher than that of Plain-URHC specimens, and it was confirmed that incorporation of bio polymer improves bond strength of mortar.

• School Mathematics
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• v.19 no.3
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• pp.423-441
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• 2017

New Zealand had reformed their national curriculum with competence and are applying the revised curriculum. As the 2015 revised national curriculum is clothed with competency-based curriculum, New Zealand may have important implications for the study of the Korean revised curriculum. In this study, we examine characteristics of the education system and the national curriculum in New Zealand. In addition, we analyze the standards into the New Zealand national curriculum in terms of 'curriculum connectivity' that is one of important curriculum criteria for improving the quality of education. For this, we look an overview of the relation between the New Zealand curriculum and NCEA, which is the core of the student-centered education system in New Zealand, and analyze the correspondence between the New Zealand curriculum and the Korean curriculum. And we establish analysis framework of curriculum connectivity based on these comparison analysis contents, and analyze Korean mathematics standards with corresponding levels from among the New Zealand mathematics curriculum. According to the results of this study, the New Zealand curriculum includes the most of standards which Korean high school students who want to enter university of natural sciences of engineering need to require. In addition, the New Zealand curriculum highlights statistical research activities for developing problem-solving ability in real life. From perspective of curriculum connectivity, 'in-depth contents' adding on to repeating mathematical concepts or contents are included in the New Zealand curriculum.

• Archives of design research
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• no.16
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• pp.101-110
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• 1996

CHOOSA GORACK which is a typical example of traditional houses in the CHO SEON dynasty consists of the four terraced builfing group. Among those,SADANG CHAI are located in the highest level,and SADANG CHAI and SADANG CHAI are toward south direction.It means that building orientation and level were influenced by the distinction of social level and the idea of ancester worship. Floor and ceiling level in the same building is different which was caused by the distinetion of social level in the CHO SEON dynasty and an ariental dual as a variety of openings,exposed ceilings,and furniture against a wall were creating a typical Korean visual harmony. Although the furniture and equipments were very important elements in ONDOL BANG the occupance ratio of these were low because the free space in BANG should be utilized effectively to accommodate the space variation.Both an AN CHAI and SARANG CHAI were composed by the standard space module called KAN.And interior elements were established by several factors such as the human scale,the behavior pattern in traditional sitting life style, and the lumber size of post and lintel construction of Korean house.BANG and DAE GHUNG, composed of KAN,were expanded and arranged side by side so that the natural light and ventilation through them could be used in the result of the kind of lay out,traffic circulation was disturved.In conclusion,CHOOSA GOTACK was formed by the sirect effice of the KOREAN penisula. However this study was based on one sample. It may not enough to deduct soild conclusion.Therefore continuous and farher study is needed for the sestemane evaluation.