• International Journal of High-Rise Buildings
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• v.12 no.1
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• pp.63-74
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• 2023

Large-capacity public transportation systems, represented by urban metro lines, are the key to alleviating the significant increase in urbanization and motorization in China. But to improve the agglomeration effect of metro stations in a more accurate and targeted way requires scientific evaluation and classification of the surrounding areas of metro stations. As spatial and functional design are the core factors for urban renewal design, this study took Beijing as an example, using multi-source data to evaluate the morphology and functional composition surrounding areas of metro stations, and the Boston Consulting Group (BCG) matrix was used to classify and characterize each type of surrounding areas from morphological-functional dimensions. It shows a negative correlation of the mix-use index with the floor area ratio, and only about 20% of the areas achieve the ideal situation of high construction intensity with high mix-use diversity. Hoping to provide a reference for city managers and designers in dealing with the surrounding metro stations with different construction intensities in a more precise way.

• Journal of the Korea Concrete Institute
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• v.19 no.3
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• pp.377-383
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• 2007

In recent years the field application of high performance concrete has been increased to improve the quality and reliability of concrete structures. The mix design of the high performance concrete includes the 2 set-off mixture theory of mortar and coarse aggregate and that of paste and aggregate. The 2 set-off mixture theory of mortar and coarse aggregate has a problem of having to determine its value through repeated experiments in applying the rheological characteristics of mortar. The 2 set-off mixture theory of paste and aggregate has never been applied to high performance concrete since it doesn't take into account the relationship between optimum fine aggregate ratio and unit volume of powder nor does it consider the critical aggregate volume ratio. As the mixture theory of these high performance concretes, unlike that of general concrete, focuses on flowability and charge-ability, it does not consider intensity features in mix design also, the unit quantity of the materials used is determined by trial and error method in the same way as general concrete. This study is designed to reduce the frequency of trial and error by accurately calculating the optimum fine aggregate ratio, which makes it possible to minimize the aperture of aggregate in use by introducing the maximum density theory to the mix design of high performance concrete. Also, it is intended to propose a simple and reasonable mix design for high performance concrete meeting the requirements for both intensity and flowability. The mix design proposed in this study may reduce trial and error and conveniently produce high performance concrete which has self-chargeability by using more than the minimum unit volume of powder and optimum fine aggregate with minimum porosity.

• Magazine of the Korea Concrete Institute
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• v.7 no.6
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• pp.224-232
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• 1995

Recently, in other.view of underwater concrete construction, special admixture agent of concrete has been developed for antiwashout of concrete under water with easy carrying out method in some foreign nations. They had successful cases in experiment and construction and it trend to use in many cases with many scales. However, in domestic, there was rare record in carrying out. In this paper, reference for successful results of experiment and construction about antiwashout underwater concrete, as variable add of special admixture agent and other agents. We have carried out property tests of fresh and hardened concrete, certified the properties and made the antiwashout underwater concrete have enough strength to endure with ea.sy construction. And we have decided the optimal mix proportion for antiwashout underwater concrete under standard state.

• Korean Institute of Interior Design Journal
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• v.20 no.2
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• pp.147-155
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• 2011

The purpose of this study is to grope for plan methods through analyzing preferences on expression methods of materials for visual differentiation in hosing space. The results are as follows : First, we could know that finish material is the important element to make differential design in housing space. It is a effective method to use the color and material of finish materials. Second, we could find they preferred woods in materials and Y color, N9.5, bright and light in colors through grasping preference about types in material elements. The preferred texture is soft and the preferred patterns are solid and geometry. Third, it is a good method to mix materials which give us different season feeling, and to mix colors which are different tones to lead the differential design by materials in housing space. In case texture and patterns, what we mix similar things is the effective method. Fourth, preference of the expression method is manifested differently depending on the selected elements. so when we plan the housing, we have to consider that. lastly, I think this study will be a basic data on a study to differentiate the design of the residential space.

• Journal of the Korean Geosynthetics Society
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• v.15 no.4
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• pp.43-52
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• 2016

This paper presents the results of a engineering characteristic to the effect of drilling fluid with different mix designs for use in bore hole collapse prevention. The bore hole collapse prevention mechanism for the bentonite based drilling fluid was first discussed together with the effect of conditioning with different additives on engineering characteristics of bentonite based drilling fluid. As result, bentonite with polymer have a outstanding characteristics as compared to CMC Properties thickening effect In the case of sea water with attatulgite be superior to bentonite. Therefore, in this paper presented qualitative result on the performance of the drilling fluid depending on the water.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.1349-1359
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• 2021

The electronic money market in Indonesia continues to experience an increase in the number of users and volume of transactions. However, the electronic money market, especially server-based, in Indonesia is becoming concentrated into a few issuers. Electronic money issuers compete in price and promotion wars to gain new customers and maintain their existing ones. This paper presents an analysis of the orientation and factors that influence the loyalty in electronic money products. The research model variables in this study are adopted from the E-Service Quality and Marketing Mix categories. These variables are hypothesized to affect the perceived value and then customer loyalty. The research population consists of all Indonesians who use server-based electronic money, with a sample of 400 individuals. The results show that, in the E-Service Quality group, reliability, responsiveness, and security significantly affect perceived value, while the perceived price and perceived promotional benefits significantly affect perceived value in the Marketing Mix group. The perceived price has the highest effect on the perceived value and customer loyalty, while the perceived value has a significant effect on customer loyalty. Finally, it was found that the customer is more sensitive to the price than quality in using electronic money.

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.1
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• pp.173-179
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• 2003

Currently, in the mix design of high strength concrete, cement content depend on the target slump which is fixed with tests. However this cause high content cement use because it is based on the mix design of normal strength concrete. Also, comparatively high content cement might decrease the durability of the concrete. Therefore, in this study, we investigated proper cement content satisfying durability, workability, compressive strength, and reviewed use of admixtures, proper sand-aggregate ratio to the cement content. The results indicate that cement content ranging $370{\sim}550kg/m^3$ did not affect the compressive strength. The field workers should consider durability, workability as well as compressive strength for determining the optimal cement content in the mix design of the high strength concrete.

• International Journal of High-Rise Buildings
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• v.6 no.2
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• pp.149-163
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• 2017

With the intensification of urban development in Chinese cities, mixed land use in urban centers extends vertically into 3-D and expands its scale from a single building to commercial clusters. The multi-level pedestrian system in city centers also changed its role from one of traffic isolation to spatial integration, where transit nodes, street sidewalks, squares, building entrances, atriums, and corridors are interconnected, both horizontally and vertically, into a whole spatial system, within which pedestrian flows are guided and shopping facilities are arranged. This paper uses spatial configuration analysis of space syntax to examine the impacts of spatial patterns on movement distribution and the business performance of tenant mix in the multi-level commercial system of the Nanshan Commercial Cultural District in Shenzhen, China. The key objective is to better understand the interactions between the socio-economic variables and spatial design parameters of a shopping complex. The research findings point to the importance of multiplicity between syntactic variables and other spatial variables in influencing the pedestrian flows, business performance and tenant mix in highly complex commercial systems. Particularly noteworthy is the relationship between spatial accessibility measures and the location of escalators, and the ways in which individual commercial buildings are embedded into the overall spatial system. The study suggests that this may lead to the preliminary identification of the spatial qualities of effective vertical extensions of mixed land use in a high-density urban settings.

• Computers and Concrete
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• v.13 no.6
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• pp.739-748
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• 2014

In this article, by using experimental studies and artificial neural network has been tried to investigate the use of nano-silica as concrete admixture to reduce alkali-silica reaction. If there are reactive aggregates and alkali of cement with enough moisture in concrete, a gel will be formed. Then with high reactivity between alkali of cement and existence of silica in aggregates, this gel will expand by absorption of water, and causes expansive pressure and cracks be formed. At the time passes, this gel will reduce both durability and strength of the concrete. By reducing the size of silicate to nano, specific surface area of particles and number of atoms on the surface will be increased, which causes more pozzolanic activity of them. Nano-silica can react with calcium hydroxide ($Ca(OH)_2$) and produces C-S-H gel. In this study, accelerated mortar bar specimens according to ASTM C 1260 and ASTM C 1567, with different mix proportions were prepared using aggregates of Kerman, such as: none admixture and plasticizer, different proportions of nano-silica separately. By opening the moulds after 24 hour and curing in water at $80^{\circ}C$ for 24 hour, then curing in (1N NaOH) at $80^{\circ}C$ for 14 days, length expansion of mortar bars were measured and compared. It was noted that, the lowest length expansion of a specimens shows the best proportion of admixture based on alkali-silica reactivity. Then, prediction of alkali-silica reaction of concrete has been investigated by using artificial neural network. In this study the backpropagation network has been used and compared with different algorithms to train network. Finally, the best amount of nano silica for adding to mix proportion, also the best algorithm and number of neurons in hidden layer of artificial neural network have been offered.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.620-626
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• 1997

In this study. use if CSA expansive additive for concrete is discussed, particulary applications to partial compacting the concrete structure of spillway gate located in Youngjong new airport construction field. Before the field applications, several basic laboratory test were carried out in order to clarify the material characteristics and to decide mix proportions. As the result the concrete using CSA expansive additive show similar workability and compressive strength to that of OPC concrete. Forethemore, it can be concluded that the use of CSA component is effective to prevent shrinkage crack and to achive volume stabiliy of concrete structure.