• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.2
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• pp.199-208
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• 2010

A friction damper installed at a building shows nonlinear behavior since its stick and slip states are occurred repeatedly depending on the amplitude of external loadings to dissipate input energy. Friction damping is existed for the building with a friction damper. In additionally viscous one is inherently included. Therefore, the building installed in such combined damping is quite involved to find the analytical solution. In this study, first, displacement and acceleration characteristics are identified based on the exact solution for a single-degree-freedom building with a friction damper having both friction and viscous damping. Second, in free vibration, the equivalent viscous damping ratio is obtained by the energy dissipation. Third, numerical analysis is carried out to find response configuration with various friction force ratios. Fourth, corresponding equivalent viscous damping ratio is derived with the finding that the response reaches into steady-state for both friction and viscous damped structure. It is deduced using balance of input external energy and output dissipation energy for steady-state response. Finally, the equivalent viscous damping ratios of free or harmonic vibration are verified through nonlinear analysis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.1D
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• pp.157-166
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• 2011

This study is to mention necessity of building Green-way by foreign theoretical backgrounds and analyzing cases of internal and external, and is purposed on assessment of projects in operation internal by above necessity. For these assessments, looking into cases of green-way plan of external and defining issues by comparing with internal cases to suggest solutions. Green-way planning methods can be classified in physical and non-physical aspects. From among these, for case of non-physical method, its environments of each nation, region, local are all different from each other and can not be turned into a numerical value and quantification, as well. Therefore, analyzing and suggesting the directions on the basis of physical method. Understanding the improvements degree of physical environment of before and after implementation of projects by using successful cases of external similar to actual state of internal. By these process, inflecting to suggest a seek way of applied to internal projects. Local aspects, doesn't have the specific analyzed data of improvement of pedestrian environment and building green-way and are shortage of implementation of projects also. For that reason this study is to look into the status and plans of building green-way in Seoul and analyzing the 7 completed region cases. And suggesting issues of projects and the direction of national and local green-way projects.

• Wind and Structures
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• v.12 no.4
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• pp.383-400
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• 2009

Low rise building roofs can be subjected to large fluctuating pressures during a tropical cyclone resulting in fatigue failure of cladding. Following the damage to housing in Tropical Cyclone Tracy in Darwin, Australia, the Darwin Area Building Manual (DABM) cyclic loading test criteria, that loaded the cladding for 10000 cycles oscillating from zero to a permissible stress design pressure, and the Experimental Building Station TR440 test of 10200 load cycles which increased in steps to the permissible stress design pressure, were developed for assessing building elements susceptible to low cycle fatigue failure. Recently the 'Low-High-Low' (L-H-L) cyclic test for metal roofing was introduced into the Building Code of Australia (2007). Following advances in wind tunnel data acquisition and full-scale wind loading simulators, this paper presents a comparison of wind-induced cladding damage, from a "design" cyclone proposed by Jancauskas, et al. (1994), with current test criteria developed by Mahendran (1995). Wind tunnel data were used to generate the external and net pressure time histories on the roof of a low-rise building during the passage of the "design" cyclone. The peak pressures generated at the windward roof corner for a tributary area representative of a cladding fastener are underestimated by the Australian/New Zealand Wind Actions Standard. The "design" cyclone, with increasing and decreasing wind speeds combined with changes in wind direction, generated increasing then decreasing pressures in a manner similar to that specified in the L-H-L test. However, the L-H-L test underestimated the magnitude and number of large load cycles, but overestimated the number of cycles in the mid ranges. Cladding elements subjected to the L-H-L test showed greater fatigue damage than when experiencing a five hour "design" cyclone containing higher peak pressures. It is evident that the increased fatigue damage was due to the L-H-L test having a large number of load cycles cycling from zero load (R=0) in contrast to that produced during the cyclone.

• Journal of the Korea Institute of Building Construction
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• v.9 no.5
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• pp.163-172
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• 2009

As customers are becoming increasingly important in corporate management, there is a growing demand for migration to customer-focused organizational structures. Unlike the manufacturing industry, the construction industry is non-iterative and non-standardized. As a result, a wide variety of materials, human resources, technologies and equipment must be mobilized in complex work activities to complete a structure. Consequently, surprises are bound to occur as such work activities progress. This paper intends to study a strategy that is designed to improve customer services for apartment building units. It aims primarily to focus on cost control and brand management. Housing tenants and industry experts are surveyed to collect input for issue analysis. In addition, the external circumstances and internal capabilities of major builders in Korea are analyzed, and a SWOT analysis is performed regarding market conditions related to customer service. These analysis results are utilized to develop a strategy implementation plan over different time frames, and the operational resources available for such strategy implementation are analyzed in order to forecast its performance. This research will facilitate communication between construction companies in Korea and their customers by proposing a customer service improvement strategy for apartment building units, and is expected to provide resource material for a strategic analysis of efforts to fully incorporate customer requirements

• Journal of architectural history
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• v.16 no.2
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• pp.79-98
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• 2007

The building site was presumed as the Howonjeokwon or the Dasiwonji established at the traffic route among western inland areas in old Pyeonghaegun. The groundwork was composed inclination terrace of two steps. The upper step was the territory of the main house of ceremony symbolic+lodging function and the down step was divided in the territory of both Ikrang-chae of boarding and lodging management function and the territory of Haengrang-chae pavilion of rest reception management. The building composition by each territory formed space differentiation with the line of flow according to the thorough rule of court rank. The arrangement composition set the strong center axis in tandem, and it was the building arrangement interpreting the territory and the rule of court rank by function as the relationship of master and servant and was the building type emphasizing on the whole unity with the geometric symmetry structure. The Dasiwonji and the Hyeeumwonji had the common point which is the traffic architecture of semi governmental management reinforcing the boarding lodging function in the place which a visitor stayed. The Haeeumwonji and Dasiwonji had the difference in the size, but was the same in the composition system of construction. The external space and the system of the line of flow decided from the functional territory separation and the hierarchical rank as thorough as the geometric arrangement focusing on the whole unity. Namely, it was the strict and unusual system of the line of flow depended on the thorough rule of court rank than the efficient approach or arrangement of the line of flow. After being established to be the Howonjeokwon at the end of Koryeo, it disappeared at the time of the invasion of Japanese pirates when it was the time of the King Woo in Koryeo. It is presumed that it was continued until both wars, Imjin Byeongja, ago after changing its name to the Dasiwon, being restored to the small size at the end of Koryeo at the early of Choseon.

• International Journal of Concrete Structures and Materials
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• v.2 no.1
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• pp.49-55
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• 2008

The disadvantage of PMM's (polymer-modified mortars) that are currently on the market is the utilization of expensive polymer additives and also the cost of the other components. One of the possibilities how to decrease this price is the effective utilization of waste materials which are very inexpensive in spite of their good properties. The combinations of different degree in polymer adhesiveness and waste secondary raw materials - fly ash - are experimentally verified in the paper. The use of fly ash in adhesive materials for ceramic tiles is limited by unsatisfactory initial adhesiveness to sintered ceramic sherd as a result of a running pozzolanic reaction that lowers the efficiency of polymer additives. On the other hand, the use of adhesive and backfill coating materials for gluing ETICS board insulation materials has brought very good results.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.11-12
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• 2015

This study analyzed sulfate resistance of strongly acid-resistant inorganic binder based on industrial byproducts. According to the study experiment, compared to OPC mixture, the mixture of high acid-resistant inorganic binder had excellent chemical resistance against 10% H₂SO₄ solution. In the case of ordinary portland cement, its sample with 28 days of immersion had severe corrosion on its mortar erosion part, and thus external appearance was damaged greatly, and compression strength decreased by around 57% and more.

• Asian Journal of Innovation and Policy
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• v.4 no.2
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• pp.217-241
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• 2015

This paper, based on two engineering industry SME case studies, traces the origin and process of technological innovations enabling the development and introduction of new products leading to market expansion and enterprise growth. The study throws light on how entrepreneurs played a decisive role in recognizing market opportunities, building up crucial in-house technological capability, supplementing it with appropriate external assistance, to carry out technological innovations. A constant interaction with its customers is in-built into the system. As a result, the SMEs could achieve successful product innovations leading to their gradual growth, over time. Finally, based on the observations and inferences derived out of the two cases, a theoretical construct of the growth of innovation in SMEs is postulated. This is done linking the three stages of their development: (i) start-up and stabilizing, (ii) building up technological capability and implementing innovations; and (iii) opening up of new markets resulting in firm growth.

• Journal of The Korean Digital Architecture Interior Association
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• v.8 no.2
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• pp.39-46
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• 2008

Current architecture can receive support of and command various ways of expression by more advanced technology of the present time, this means the formation of changeable external design of building, and has the tendency to be interactive non-rheological shape. Accordingly surface of building is decorated not only by the basic function and the expression of information, but also by complex narrative image structure or text, so far as recognizes human as the subject of communication, and is trying the artistic expression interacting with the general public. In various expressive tendency of current architecture surface design, such an approach from a view of an interactive art trying the communication between architecture, art, and human has the meaning of suggesting the direction of directing emotional architecture giving a present to the morderners who are growing more and more an earnest desire for experiencing culture and art in their daily life.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2002.05a
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• pp.81-84
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• 2002

Recently Bentonite mat is applied various structure : External waterproofing for underground structure, A reclaimed land, Artificial lake, Large-scaled civil structure, etc. With these various structure environment, water quality for application of Bentonite Mat affects watertightness. Specially spot with a large quantity of Chloride ion like salt water, degree of watertightness revelation is evaluated and applied. In this study, it is a main goal to investigate watertightness of Bentonite Mat with distilled water and salt water dissolved chloride ion Contents 0.88%. The result of this paper is as follows. 1) Water permeability coefficient of Bentonite Mat : distilled water(1.21$\times$10$^{-9}$cm/sec), salt water(3.12$\times$10$^{-7}$cm/sec). 2) Variation of thickness : distilled water(187%), salt water(108%). 3) Swelling ratio : distilled water(1500%), salt water(350%).