• Title/Summary/Keyword: building structural systems

Search Result 666, Processing Time 0.028 seconds

A Study on the Impacts of users' Needs for Cognition(NFC) on the Online Brand Community and Brand Loyalty (사용자의 인지욕구 특성이 온라인 커뮤니티 충성도와 브랜드 태도에 미치는 영향에 관한 연구)

  • Lee, Sun-Ro;Cho, Jung-Hyun;Cho, Sung-Min
    • Asia pacific journal of information systems
    • /
    • v.17 no.4
    • /
    • pp.1-29
    • /
    • 2007
  • The brand-based online community recently plays an important roles for consumers to facilitates searching and sharing information among them. Firms often find such a brand community as a critical channel to gain collective intelligence for developing new ideas and products. As a new web platform such as web 2.0 has been introduced, consumers could more easily participate in the new social networks created by sharing mutual value and belief among themselves. Accordingly firms began to recognize potentials of online brand assets and pay attention to the importance of online brand community loyalty. Previous research related to online community tends to focus on identifying the antecedents of community loyalty and their subsequent impacts on brand. They, however, tend to neglect the importance of individual characteristics of online community users. As integrating the fragmented variables with an individual characteristics, therefore, this study reexamined the impacts of interactivity, information, reward, and personalization services provided by an online brand community on the sense of community, community loyalty, and brand attitude. Also, this study investigated how users' individual characteristics(need for cognition: NFC) can play moderating roles among the variables identified in the previous research. A field survey was administrated and 671 valid samples were collected. In order to test the hypothesis we conducted the multi-sample structural equation modeling(MSEM) between two groups(a group with high vs. a group with low level of NFC). Results show that previously identified variables such as interactivity, information, reward, and personalization services have significant effects on the sense of community as previous research demonstrated. Subsequently, the sense of community positively influences the community loyalty and brand attitude. However, when considering the NFC as a moderating variable, we found that the effect of interactivity and reward service on the sense of community was stronger for a group with a lower level of NFC compared to a group with a higher level, while the effect of information providing service on the sense of community was stronger for a group with a higher level of NFC compared to a group with a lower level. This research revealed that NFC can affect the degree of individual perception on the sense of community which has been considered as an important indicator for the community loyalty and brand attitude. Hence, when firms developing customer relation strategy through building an online brand community, they need to reflect customers' NFC and accordingly provide varying degree of interactivity, information, reward, and personalization services.

Seismic Behaviour of Exterior Joints in Post-Tensioned Flat Plate Systems (포스트 텐션 플랫 플레이트 외부 접합부의 내진 거동)

  • Han, Sang-Whan;Kee, Seong-Hoon;Kang, Tomas H.K.;Cho, Jong;Lee, Li-Hyung
    • Journal of the Korea Concrete Institute
    • /
    • v.18 no.5 s.95
    • /
    • pp.595-602
    • /
    • 2006
  • An experimental study was conducted to investigate seismic behaviour of post-tensioned(PT) exterior slab-column connections used for the purpose to resist gravity loads only. For these, 2/3-scale, two PT post-tensioned exterior connections with two different tendon arrangement patterns and one conventional reinforced concrete(RC) exterior connection was tested under quasi-static, uni-directional reversed cyclic loading. During the lateral testing, gravity forces transferred to the column were kept constant to closely simulate a moment to shear ratio of a real building. One of the objectives of this study was to assess the necessity and/or the quantity of bottom bonded reinforcement needed to resist moment reversal which would occur under significant inelastic deformations of the adjacent lateral force resisting systems. The ACI 318 and 352 provisions for structural integrity were applied to provide the bottom reinforcement passing through the column for the specimens. Prior test results were also collected to conduct comparative studies for some design parameters such as the tendon arrangement pattern, the effect of post-tensioning forces and the use of bottom bonded reinforcement. Consequently, the impact of tendon arrangement on the seismic performance of the PT connection, that is lateral drift capacity and ductility, dissipated energy and failure mechanism, was considerable. Moreover, test results showed that the amount of bottom reinforcement specified by ACI 352. 1R-89 was sufficient for resisting positive moments arising from moment reversal under reversed cyclic loads. Shear strength of the tested specimens was more accurately predicted by the shear strength equation(ACI 318) considering the average compressive stress over the concrete($f_{pc}$) due to post-tensioning forces than that without considering $f_{pc}$.

Investigation for Developing 3D Concrete Printing Apparatus for Underwater Application (수중적층용 3D 콘크리트 프린팅 장비 개발에 대한 연구)

  • Hwang, Jun Pil;Lee, Hojae;Kwon, Hong-Kyu
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.44 no.3
    • /
    • pp.10-21
    • /
    • 2021
  • Recently, the demand for atypical structures with functions and sculptural beauty is increasing in the construction industry. Existing mold-based structure production methods have many advantages, but building complex atypical structures represents limitations due to the cost and technical characteristics. Production methods using molding are suitable for mass production systems, but production cost, construction period, construction cost, and environmental pollution can occur in small quantity batch production. The recent trend in the construction industry calls for new construction methods of customized small quantity batch production methods that can produce various types of sophisticated structures. In addition to the economic effects of developing related technologies of 3D Concrete Printers (3DCP), it can enhance national image through the image of future technology, the international status of the construction civil engineering industry, self-reliance, and technology export. Until now, 3DCP technology has been carried out in producing and utilizing residential houses, structures, etc., on land or manufacturing on land and installing them underwater. The final purpose of this research project is to produce marine structures by directly printing various marine structures underwater with 3DCP equipment. Compared to current underwater structure construction techniques, constructing structures directly underwater using 3DCP equipment has the following advantages: 1) cost reduction effects: 2) reduction of construct time, 3) ease of manufacturing amorphous underwater structures, 4) disaster prevention effects. The core element technology of the 3DCP equipment is to extrude the transferred composite materials at a constant quantitative speed and control the printing flow of the materials smoothly while printing the output. In this study, the extruding module of the 3DCP equipment operates underwater while developing an extruding module that can control the printing flow of the material while extruding it at a constant quantitative speed and minimizing the external force that can occur during underwater printing. The research on the development of 3DCP equipment for printing concrete structures underwater and the preliminary experiment of printing concrete structures using high viscosity low-flow concrete composite materials is explained.

A Study on EC Acceptance of Virtual Community Users (가상 공동체 사용자의 전자상거래 수용에 대한 연구)

  • Lee, Hyoung-Yong;Ahn, Hyun-Chul
    • Asia pacific journal of information systems
    • /
    • v.19 no.1
    • /
    • pp.147-165
    • /
    • 2009
  • Virtual community(VC) will increasingly be organized as commercial enterprises, with the objective of earning an attractive financial return by providing members with valuable resources and environment. For example, Cyworld.com in Korea uses several community services to enable customers of Cyworld to take control of their own value as potential purchasers of products and services. Although initial adoption is important for online network service success, it does not necessarily result in the desired managerial performance unless the initial usage is continuously related to the continuous usage and purchase. Particularly, the customer who receives relevant online services and is well equipped with online network services, will trust the online service provider and perceive less risk and experience more activities such as continuous usage and purchase. Thus, how to promote continued online service usage or, alternatively, how to prevent discontinuance is a critical issue for VC service providers to consider. By aggregating a wide range of information and online environments for customers and providing trust to its members, the service providers of virtual communities help to reduce the perceived risk of continuous usage and purchase. Drill down, online service managers realize that achieving strong and sustained customers who continuously use online service and purchase on it is crucial. Therefore, the research into this online service continuance will identify the relationship between the initial usage and the continuous usage and purchase. The research of continuous usage or post adoption has recently emerged as an important issue in the IS literature. Individuals' information systems(IS) continuous usage decisions are congruent with consumers' repeat purchase decisions. The TAM(Technology Acceptance Model) paradigm has been strongly confirmed across a wide range from product purchase on EC to online service usage contexts. The analysis of IS usage based on TAM has proven to be successful across almost online service contexts. However, most of previous studies have focused on only an area (i.e., VC or EC). Just little research has tried to analyze the relationship between VC and EC. The effect of some factors on user intention, captured through several theories such as TAM, has been demonstrated. Yet, few studies have explored the salient relationships of VC users' EC acceptance. To fill this gap between VC and EC research, this paper attempts to develop a research model that extends the TAM perspective in view of the additional contributions of trust in the service provider and trust in members on some factors that affect EC and VC adoption. In this extension, we applied the TAM-to-TAM(T2T) model, and analyzed the transfer effect of trust between these two TAMs. The research model was empirically tested on the context of a social network service. The model was to extend TAM with the trust concept for the virtual community environment from the perspective of tasks. By building an extended model of TAM and examining the relationships between trust and the existing variables of TAM, it is aimed to explain a user's continuous intention to use VC and purchase on EC. The unit of analysis in this paper is an individual user of a virtual community. The population of interest is the individual with the experiences in virtual community. The data for this paper was made available via a Web survey of VC users. In total, 281 cases were gathered for about one week, but there were some missing values in the sample and there were some inappropriate cases. Thus, only 248 cases were finally analyzed. We chose the structural equation analysis to test the hypotheses and it is better suited for explaining complex relationships than the other methods. In this test, AMOS was used to test the Structural Equation Model (SEM). Noticeable results have been found in the T2T model regarding the factors affecting the intention to use of virtual community and loyalty. Our result showed that trust transfer plays a key role in forming the two adoption beliefs. Overall, this study preliminarily confirms the salience of trust transfer in online service.

A Study on the Architectural Education System for Globalization (국제화시대에 대비한 우리나라 건축교육제도 개선 연구)

  • Yim Chang-Bok
    • Journal of Engineering Education Research
    • /
    • v.2 no.1
    • /
    • pp.39-50
    • /
    • 1999
  • In recent globalization era, Korean architectural education and profession are emerging as the fields with serious problems. There are two major reasons. One is an internal factor caused by Ministry of Education's full scale shift from department to faculty system. Due to the drastic change in this system, most of schools have serious difficulties to deliver the proper professional education. And the other is an external factor. In WTO era, Union of International Architects has adopted $\ulcorner$UIA Accord on Recommended International Standards of Professionalism In Architectural Practice$\lrcorner$. According to the education section of the Accord, it requires 5 years of professional education in the accredited school. So, if it is formally adopted in the Beijing Congress, which is scheduled to be held in June 1999, we may face very serious problems in architectural education. As mentioned above, with the present education system it is believed not easy to meet their new criteria. Within the present system, which does not have any mandatory relationship with professional licence, students might go on to diverse fields such as architectural design, structural engineering, construction management and building equipment engineering. However, if UIA Accord and Engineering Accreditation are required at the same time, it will not be easy to meet their new criteria with present architectural education system. The goal of this paper is to suggest the models to meet the standards of international community while keeping the strengths of existing systems.

  • PDF

The use of SMA wire dampers to enhance the seismic performance of two historical Islamic minarets

  • El-Attar, Adel;Saleh, Ahmed;El-Habbal, Islam;Zaghw, Abdel Hamid;Osman, Ashraf
    • Smart Structures and Systems
    • /
    • v.4 no.2
    • /
    • pp.221-232
    • /
    • 2008
  • This paper represents the final results of a research program sponsored by the European Commission through project WIND-CHIME ($\underline{W}$ide Range Non-$\underline{IN}$trusive $\underline{D}$evices toward $\underline{C}$onservation of $\underline{HI}$storical Monuments in the $\underline{ME}$diterranean Area), in which the possibility of using advanced seismic protection technologies to preserve historical monuments in the Mediterranean area is investigated. In the current research, the dynamic characteristics of two outstanding Mamluk-Style minarets, which similar minarets were reported to experience extensive damage during Dahshur 1992 earthquake, are investigated. The first minaret is the Qusun minaret (1337 A.D, 736 Hijri Date (H.D)) located in El-Suyuti cemetery on the southern side of the Salah El-Din citadel. The minaret is currently separated from the surrounding building and is directly resting on the ground (no vaults underneath). The total height of the minaret is 40.28 meters with a base rectangular shaft of about 5.42 ${\times}$ 5.20 m. The second minaret is the southern minaret of Al-Sultaniya (1340 A.D, 739 H.D). It is located about 30.0 meters from Qusun minaret, and it is now standing alone but it seems that it used to be attached to a huge unidentified structure. The style of the minaret and its size attribute it to the first half of the fourteenth century. The minaret total height is 36.69 meters and has a 4.48 ${\times}$ 4.48 m rectangular base. Field investigations were conducted to obtain: (a) geometrical description of the minarets, (b) material properties of the minarets' stones, and (c) soil conditions at the minarets' location. Ambient vibration tests were performed to determine the modal parameters of the minarets such as natural frequencies and mode shapes. A $1/16^{th}$ scale model of Qusun minaret was constructed at Cairo University Concrete Research Laboratory and tested under free vibration with and without SMA wire dampers. The contribution of SMA wire dampers to the structural damping coefficient was evaluated under different vertical loads and vibration amplitudes. Experimental results were used along with the field investigation data to develop a realistic 3-D finite element model that can be used for seismic risk evaluation of the minarets. Examining the updated finite element models under different seismic excitations indicated the vulnerability of such structures to earthquakes with medium to high a/v ratio. The use of SMA wire dampers was found feasible for reducing the seismic risk for this type of structures.

Generation of Floor Response Spectra including Equipment-Structure Interaction in Frequency Domain (진동수 영역에서 기기-구조물 상호작용을 고려한 층응답스펙트럼의 작성)

  • Choi, Dong-Ho;Lee, Sang-Hoon
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.9 no.6 s.46
    • /
    • pp.13-19
    • /
    • 2005
  • Floor response spectra for dynamic response of subsystem such as equipment, or piping in nuclear power plants are usually generated without considering dynamic interaction between main structure and subsystem. This study describes the analytic method in which equipment response spectra can be obtained through dynamic analysis considering equipment-structure Interaction(ESI). In this method, dynamic response of the equipment by this method is based on a dynamic substructure method in which the equipment-structure system is partitioned into the single-degree-ol-freedom system(SDOF) representing the equipment and the equipment support impedance representing the dynamic charactenstics of the structure ai the equipment support. A family of equipment response spectra is developed by applying this method to calculate the maximum responses of a family of SDOF equipment systems with wide banded equipment frequency, damping ratio, and mass. The method is validated by comparing the floor response spectrum from this method with the floor response spectrum generated from the rigorous analysis including equipments on the containment building of a prototypical nuclear power plant. in order to Investigate ESI effect in the response of equipment, response values from the method and the conventional approach without considering ESI are compared for the equipment having the mass less than 1% of the total structural mass. Response spectra from the method showed lower spectral amplitudes than those of the conventional floor response spectra around controlling frequencies.

Experimental Performance Evaluation of a Fire System for Apartment Buildings (공동주택 전용화재시스템의 성능평가를 위한 실험적 연구)

  • Jung, Jong-Jin;Hong, A-Reum;Son, Bong-Sei
    • Fire Science and Engineering
    • /
    • v.29 no.6
    • /
    • pp.51-56
    • /
    • 2015
  • In Korea, measures to maintain sustainable fire safety performance for apartment buildings are insufficient in terms of fire-fighting products, skilled personnel, and maintenance status. Also, because of the particular features of a fire compartment, it has structural problems that are very likely to cause damage to human life when a fire occurs. Currently, problems with the fire supervisory system installed in an apartment building cannot be checked in real time, so it is difficult to identify the location of a fire accurately. Protected areas are also not assigned to each household, and residents cannot be clearly informed of the occurrence of a fire. As a consequence, safety evacuation cannot be secured. In addition, it is impossible to test the operation performance for water detectors in sprinkler fire extinguishing systems outside of the household. Therefore, an experiment was conducted to evaluate the performance of a remote fire supervisory system. The results show that the system satisfies all performance requirements. Also, an household alarm system was installed in each household to alert of any occurrence of a fire accurately, and the performance of the alarm system was improved to ensure that residents were quickly evacuated.

Development of Three Dimensional Analysis Method of High-Rise Buildings Considering the Construction Sequence and the Inelastic Behavior (시공 단계 및 비탄성거동을 고려한 초고층 건축물의 3차원 해석 기법 개발)

  • Yang, Joo-Kyoung;Seol, Hyun-Cheol;Kim, Jin-Keun
    • Journal of the Korea Concrete Institute
    • /
    • v.20 no.2
    • /
    • pp.249-256
    • /
    • 2008
  • With consideration of the ongoing construction of high-rise buildings, it is becoming increasingly important to be able to accurately predict the behavior of them on the stage of design, construction and service. Even though many researchers have developed the analysis method to predict the behavior of high-rise buildings, their studies were based on the two dimensional frame structures composed of line elements such as beams and columns. Recently the high-rise buildings with flat-plate system is widely used because of its advantages. In this study a three dimensional analysis method is developed to analyze the behavior of the high-rise buildings with flat-plate system since it is difficult to model the structural systems reasonably with the existing two dimensional analysis method. The analysis method considered the construction sequence including the temporary work such as installation of form, removal of form, installation of shore, and removal of shore. Line elements were used to describe columns, beams, and shores and plate elements were used to model slabs. The creep and drying shrinkage of concrete were also considered to account for the inelastic behavior of concrete.

A Technique to Specify and Generate .NET Components in MDA/PSM for Pervasive Service (MDA/PSM상에서 퍼베이시브 서비스를 지원하는 닷넷 컴포넌트의 명세 및 생성 기법)

  • Kum, Deuk-Kyu;Kim, Soo-Dong
    • Journal of KIISE:Software and Applications
    • /
    • v.34 no.7
    • /
    • pp.635-645
    • /
    • 2007
  • Component technology has been widely accepted as an effective way for building software systems with reusable components, and Microsoft (MS) .NET is one of the recent representative component technologies. Model Driven Architecture (MDA) is a new development paradigm which generates software by transforming design models automatically and incrementally. Transformation of structural models in MDA has been successfully applied. However, transformation of dynamic models and pervasive services, such as transaction service, security service, synchronization service and object pooling are largely remains as an area for further research. The recent enterprise system has multi tier distributed architecture, and the functionality of early mentioned pervasive services is essential for this architecture. .NET platform can implement Component Object Model+ (COM+) component for supporting pervasive services by specify Attribute code. In this paper, we specify the functionalities of the COM+ component offering pervasive services, and then those functionalities are defined by UML profile. By using the profile, the Platform Specific Model (PSM) for .NET/C# is specified, and .NET components are automatically generated through our tool. The development productivity, extensibility, portability, and maintenance of software can be dramatically improved by using of the proposed methods.