• 한국자동차공학회논문집
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• 제3권6호
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• pp.112-122
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• 1995

As an alternative fuel producing less exhaust emissions, natural gas is of interest for use both in SI and CI engines. The potential of natural gas fuelled dual-fuel engine is considered high enough. However, much effort has to be made so that gaseous fuel is used efficiently with simultaneous minimum use of pilot oil. Hence, a simplified three-dimensional model, using a finite volume method in cylindrical coordinates, has been developed to facilitate an understanding of the dual-fuel combustion phenomena and to predict the complex interactions between the pilot distillate and natural gas. The computer model was calibrated by comparing it with the experimental results obtained from diesel engine like combustion bomb tests. In the pre-mixed natural gas combustion, the fuel burning was highly reliant on the injection condition and subsequent burning nature of the pilot distillate.

• 소음진동
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• 제4권2호
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• pp.155-161
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• 1994

The dynamic behavior of a complex mechanical structure can be identified by dividing the structure into a series of smaller structure, called sub- structure and by studying the dynamic characteristics of these components. Generally, the dynamic characteristics of mechanical structure are strongly affected by the properties of joint parameters. In this paper, to identify the dynamic characteristics of mechanical structure, and experimental identification method in which directrly measured frequency response function(FRF) is used is considered. The method does not use the procedure of complex matrix calculation but use that of real matrix calculation. To confirm this method, computer simulation is performed by using frequency response function mixed with noise, and the experimental study is performed about the simple structure. The dynamic characteristics of joint parameters and identified more accurately than in using the prcedure of complex matrix calculation.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2008년도 춘계 학술논문 발표대회
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• pp.127-131
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• 2008

The successful project management is based on definition of project goals in construction industry. The WBS(Work Breakdown Structure) is one of the major factors which defines works related to project goals. The necessity of the WBS for owners in multi complex projects which would help them to understand the whole project is rising because the multi-complex project in the construction industry has increasing recently. Therefore, this study suggests directions to establish the WBS for owners through investigating a concept of the multi-complex project first and analyzing types of project, domestic and foreign WBS, and case studies.

• 토지주택연구
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• 제3권1호
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• pp.1-14
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• 2012

Since the provision of Permanent Affordable Housing in the early 1990's, it is confronted with the need to strengthen its welfare service due to aging of its facilities and the declining welfare system for its tenants. In addition, the aging population of tenants is on the rise, increasing the group of tenants that are in need of care. The local social community center has entered into the community of permanent affordable housing and takes partial responsibility in the tenant's social welfare. However, social community center is mainly responsible for providing welfare service to its local residents and thus limited in its ability to satisfy welfare service to tenants of permanent affordable housing. Therefore, it is required to renew the existing welfare system to better suit social demands of tenants according to its specific social group and the characteristics of housing complex. This study aims to propose methods that can strengthen welfare service and analyze the characteristics of welfare service by investigating the existing conditions of welfare system for the tenants in permanent affordable housing complex. For this purpose, this study presents with categories of service standards, by breaking down and codifying welfare service and propose applicable mixed-use service in pre-existing permanent affordable housing.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2006년도 추계학술발표대회 논문집
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• pp.346-351
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• 2006

Community facilities in apartment complex was developed through combination with residents' needs about housing environmental amenity, marketing competition among construction companies and social trend 'Well-being' . But community facilities and fitness center which are situated in the beginning are alienated by residents because the designers plan community facilities without considering about residents' life-style and preference. In this paper, the study includes present status of fitness center and residents' preference for proper fitness center design. The result presents that fitness center users in apartment complex want a resting space which is already located in fitness center of mixed-use residential building. A resting space provides conditions that users can make up with the community each other as well as they can rest after exercise. And the fitness center users prefer wood as interior finish material of floor and wall in exercising space and resting space because they have a feeling comfortable and splendid.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.124-125
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• 2014

Polymer concrete has more excellent durability, tensile strength, flexural strength and waterproof performance mechanically than normal concrete, and as it mixes as a polymer binding material, it can reduce the cement use amount. This study reviews fundamental properties of cement material mixed with complex polymer. As a result of this study, as percentage of complex polymer mix increases, flow value will decrease so that liquidity and compression strength will decrease. On the other hand, in case of flexural strength, when the mixture is 10%, it increases significantly more than OPC.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2009년도 추계학술발표대회 논문집
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• pp.77-81
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• 2009

The elderly population ratio of domestic is the actual condition where the countermeasure which is various for there is a possibility of saying that is already experiencing the aging society, is considered. The expansion of the elderly welfare facility of the area where is located among the rest in the situation as a matter of metropolitan area of domestic ephemerality and the price of land which the earth has, duplication operation etc. is having a problem point and the ephemerality which are various. About of composition different facility and leads with alternative and expansion and function of function and facility leads and the synergy effect which is various shows. So this study is consequently does the school facility which is located in life circle of the city center in middle of composition of the elderly welfare facility and other facility and in the object and under proposing boil the complex at the time of spatial composition blueprint with the elderly welfare facility and the school.

• Nuclear Engineering and Technology
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• 제55권10호
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• pp.3665-3676
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• 2023

The use of ion exchange resins to remove ionic impurities from solution is prevalent in industrial process systems, including in the primary heat transport system (PHTS) purification circuit of nuclear power plants. Despite its extensive use in the nuclear industry, our general understanding of ion exchange cannot fully explain the complex chemistry in ion exchange beds, particularly when operated at or near their saturation limit. This work investigates the behaviour of mixed-bed ion exchange resin, saturated with species representative of corrosion products in a CANDU (Canadian Deuterium Uranium) reactor PHTS, particularly with respect to iron chemistry in the resin bed and the removal of lithium ions from solution. Experiments were performed under deaerated conditions, analogous to normal PHTS operation. The results show interesting iron chemistry, suggesting the hydrolysis of cation resin bound ferrous species and the subsequent formation of either a solid hydrolysis product or the soluble, anionic Fe(OH)₃^-.

• 한국환경복원기술학회지
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• 제23권3호
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• pp.1-22
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• 2020

This study was conducted as a basic data for preparing future management alternatives by analyzing the status and characteristics of invasive alien plants by land-use type based on the formation of a new town in Goyang Siksa district. As a result, the invasive alien plants in the Goyang Siksa district were 20 families 46 genera 57 taxa; according to the land-use type, the residential area(Wi City apartment complex) is 7 families 10 genera 12 taxa, the public facilities area(Dongguk University campus) is 17 families 40 genera 47 taxa, the mixed forest is 5 families 10 genera 10 taxa, the rice paddy is 5 families 6 genera 7 taxa, river(Mt. Gyeondal creek) is 7 families 13 genera 15 taxa were appeared. The life-form of invasive alien plants in Goyang Siksa district is annuals, the origin is America, the introduction time is third period(1962~the present), and the diffusion grade is wide spread(5 grade) species. It was higher than other types. The naturalization index by location was 31.9% in river(Mt. Gyeondal creek), 21.2% in rice paddy, 16.7% in mixed forest, 15.5% in public facilities area(Dongguk University campus), and 8.5% in residential area(Wi City apartment complex). As a result of comparing the naturalization index by regions with the previous studies, it is judged that there are differences due to the environment such as urbanization progress, size, area, population inflow and location conditions. Although many new towns have been established to date, there is a lack of research on flora (including invasive alien plants) as a basic data for preparing management alternatives. Therefore, Through this study, basic data on the management of exotic plants by land use unit in urban areas can be provided.

• Journal of Periodontal and Implant Science
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• 제45권1호
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• pp.2-7
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• 2015

A fundamental problem in analyzing complex multilevel-structured periodontal data is the violation of independency among the observations, which is an assumption in traditional statistical models (e.g., analysis of variance and ordinary least squares regression). In many cases, aggregation (i.e., mean or sum scores) has been employed to overcome this problem. However, the aggregation approach still exhibits certain limitations, such as a loss of power and detailed information, no cross-level relationship analysis, and the potential for creating an ecological fallacy. In order to handle multilevel-structured data appropriately, mixed effects models have been introduced and employed in dental research using periodontal data. The use of mixed effects models might account for the potential bias due to the violation of the independency assumption as well as provide accurate estimates.