• Title/Summary/Keyword: Quantity Take-Off

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PERFORMANCE EVALUATION FRAMEWORK FOR ENGINEERING CONSULTANTS OF TAIPEI RAPID TRANSIT SYSTEMS

  • Chien-Hui Sun;Nie-Jia Yau
    • International conference on construction engineering and project management
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    • 2011.02a
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    • pp.426-431
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    • 2011
  • The quality of performance evaluation on engineering consultants that provide design-related technical services is difficult to be measured, and only a handful of papers discussed the quality during the design stage. Although design cost is relatively far less than construction cost for a project, the decisions made in the design phase have a significant impact on the final products of the project, especially for large public construction projects. Therefore, this research focuses on reviewing and then establishing a performance evaluation framework for the consulting firms that execute detailed design and provide technical services for the Taipei Rapid Transit Systems (TRTS). By interviewing experts, this study first established a set of indicators to evaluate these firms' performance. Then, those indicators were incorporated into the four aspects of balanced scorecard (BSC) to establish the architecture of the evaluation mechanism. The weight of each indicator was calculated by analytic hierarchy process (AHP) from a survey conducted among experts. The results showed that the top-three indicators were quantity take-off, functions conformity, and budgeting. The framework of performance evaluation established by this study can be applied to measure service performance during the design stage. It not only facilitates the monitoring of consulting firms, but also helps to reduce unnecessary change orders and disputes during the construction stage.

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Conceptual Cost Estimate Method of Public Office Building Structural Frame Work by Regression Analysis (회귀분석을 통한 공공청사 골조 공사의 개산견적 방안)

  • Jo, Yeong-Ho;Choi, Hyun-Jun;Kim, Jung-Won;Yun, Seok-Heon
    • Journal of the Korea Institute of Building Construction
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    • v.20 no.2
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    • pp.147-153
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    • 2020
  • It is important to estimate the optimal construction cost at the early stage of the project. In this regard, conceptual cost estimate is an important factor for estimate optimal construction cost. However, domestic conceptual cost estimate are only used as cost per unit area according to the building type, and it's accuracy is not high. Hence, the purpose of this study is to calculate the approximate quantity and cost for reinforcing bars, concrete, and formwork by presenting a regression formula based on the total floor area of the common work items in the frame work. In order to verify the accuracy and validity of the regression formula presented in this study, a comparative analysis was performed by applying the regression formula and the traditional approximate quantity take-off method to real cases. As a result, the estimated error rate of the traditional method was -102~+55%, and exceeded the estimated conceptual cost estimate accuracy range of -50~+100% suggested by AACE(American Association of Cost Engineering). On the other hand, the error rate of the regression formula method presented in this study was -6.4~+11.62%. This can be used not only for conceptual cost estimate range of accuracy, but also for detailed estimates. However, it is necessary to analyze the factors that affect the unit price as well as quantity in order to calculate the appropriate cost.

Improvement of Quantity Take-Off and BoQ through the LOD Criteria Analysis of BIM Models (BIM 모델 표현 수준(LOD) 분석을 통한 내역체계 개선방안 연구)

  • Choi, Hyunjun;Yun, Seokheon
    • Korean Journal of Construction Engineering and Management
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    • v.20 no.6
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    • pp.89-97
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    • 2019
  • Recently, BIM has been actively introduced in construction projects. In particular, the introduction of BIM in cost estimating process is expected to improve the accuracy and efficiency of the cost estimate. However, the quantity calculation and BoQ documents preparation process still require manual work. Although the BIM model may support quantification process, it is still problematic that the level of detail of the model must be very detailed to meet the items in BoQ. To address this, it is necessary to analyse the LOD criteria and to analyze the extent to which quantity can be computed according to the level of detail in the BIM model. For the analysis of LOD-based work items, the work item grades were divided into A,B, and C. In this study, the ratio and cost of each item that can be calculated at the LOD level in the detailed design phase are reviewed for each type of work, and the method for improving the quantity calculation using BIM is proposed. In the LOD 300 stage(Detailed design stage), the largest number of items in the class B, the major improvement class, are window and glass work. In addition, the most expensive type of work was analyzed by reinforced concrete work. In the future, it is necessary to suggest appropriate improvement way for items with high item ratios and items with high cost ratios. The results of this study are expected to be used as a BIM-based cost estimation or as basic data for improving the current BoQ system.

Mix Design of High Performance Concrete Using Maximum Density Theory (최대 밀도 이론을 이용한 고성능콘크리트의 배합 설계)

  • Lee, Seung-Han;Jung, Yong-Wook
    • 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.

Development Method on Interface Module for IFC-Based Data Exchange of Building Structures (IFC 기반의 건축구조물 자료교환을 위한 연계모듈 개발 방안)

  • Jung, Jong-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.4
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    • pp.2484-2490
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    • 2014
  • The purpose of this study is to propose the method to develop IFC interface module with less time and effort, which can support the IFC-based data exchange of building structures. The core of the IFC interface module is that 1) the physical and conceptual objects well suited to the knowledge and experience of the building structures are exploited and 2) no in-depth knowledge about IFC is required. The proposed method is to 1) divide the IFC interface module into public part open to the external applications and the supporting private part, 2) reorganize the IFC entities related to the building structures into the public part, and 3) reorganize the other IFC entities into the private part. In this study, the IFC interface module was developed and then verified by the application of the module to visualization, member listing, quantity take-off and interface to Tekla of an IFC file.

Analysis of Web Caching Techniques for Efficient Web Data Loading (효율적인 웹 데이터 로딩을 위한 웹 캐싱 기법 분석)

  • Kim, Hyun-Gook;Park, Jin-Tae;Moon, Il-Young
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.05a
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    • pp.497-500
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    • 2018
  • As the fourth industrial revolution began to take off in earnest, the quality and quantity of data shared among devices began to increase exponentially over the network. In addition, the category of devices where people are exposed to such data has become diversified into desktops, mobile phones, smart phones, smart pads, and smart watches. As a result, the medium that contacts the data has begun to change, and the place where modern society has the most data is smart device. However, smart devices still leave much to be desired in terms of network speed and hardware specifications to handle large amounts of data at one time. Therefore, in this paper, we analyze the use of Service Worker, IndexedDB, and LocalStroage, which can retrieve a large amount of web contents more efficiently from mobile devices, and suggest ways to improve it.

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Development of BIM Standard Database System for an Approximate Estimate of Old-Aged Apartment Remodeling Project (노후공동주택 리모델링의 개략견적을 위한 BIM 데이터베이스 구축)

  • Lee, Dong-Gun;Cha, Hee-Sung
    • Korean Journal of Construction Engineering and Management
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    • v.11 no.5
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    • pp.53-64
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    • 2010
  • Remodeling becomes the significant issue in the aspect of the resource recycling, because it does not demolishes the whole buildings, but a part of main structure. However, compared with new construction, remodeling has several problems of adding the repair and rehabilitation works, using the partial demolition method, and having difficulties of making decision due to disagreement between several owner organizations. BIM, which is the total solution for managing and producing information during whole life cycle of the buildings, seems to be the right solution for the way to address these issues. has a possibility for solving the problems. Therefore this paper provided the framework and database for applying the BIM in the remodeling, and proved the applicability of the BIM database in the remodeling project through the case studies.

An Case-Study on the Constructing Process of Power in Cyberspace (가상공간에서의 권력형성과정에 대한 사례 연구)

  • Lee, Oh-Hyeon
    • Korean journal of communication and information
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    • v.23
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    • pp.79-112
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    • 2003
  • The purpose of this study is to explore the way that power in cyberspace is constructed and work and the factors that contribute to forming the power by analyzing a bulletin board system(BBS) on an everyday drama, "Can't Take My Eye Off You"(MBC). Research findings are as follows. The participants in the BBS produce various discourses and constantly compete with each other. In the process, the participants who produce a dominant discourse in quantity tend to exclude other discourses from the BBS and the participants who produce the minority discourses sometimes resist the dominant discourse but tend to refrain from expressing the minority discourses. These tendencies have intensified, and eventually the dominant discourse overwhelmingly powers over the BBS at the end of it. The dominant discourse in the BBS is confucian patriarchal one and this is primarily due to the characteristic of the BBS as the fandom of the drama, the participants' experience and dominant culture in their embodied social world, and the authorship of the drama.

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Quilitative certificational plan of mudanpi (목단피(牧丹皮)의 품질인증(品質認證) 방안(方案))

  • Lim, Joong-Keun;Roh, Seong-Soo;Kil, Ki-Jeong;Seo, Bu-il;Seo, Young-Bae
    • Journal of Haehwa Medicine
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    • v.13 no.2
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    • pp.169-178
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    • 2004
  • Now many sustitution and false articles is used in korea instead of mudanpi. To use mudanpi correctly, we will make a quilitative certificational plan of mudanpi to investigate all of lieraturea, records and documents. And we could reach conclusions as folloews. 1. Source Source of mudanpi is cortex of Paeonia suffruticosa Andrews(Family:Ranunculaceae) in korea and china. It needs an attention to distinguish into because there is a substitute and a rank in china. 2. process We have to work before harvesting fresh roots is dry perfectly. If outer skin dried moisture a little, cut off outer skin vertically at sunny day, remove a heart and sever, immedietly dry. When working, we have to take care of because of easy discoloration with moisture. 3. Quality (1) Functional standards A diameter is large, it do not exist a heart of wood, a bark is thick and powdery. Section surface is light white color and rich odor with many light crystals. (2) Physicochemical stamdards We think that it needs to raise a contant of paeonol at all kinds of testing standards. A contant of paeonol is at least more than 2.5%. A part of wood indicate a heart of wood which has no medical effects, but is a relatively heavy part. So a standart of wood must be lowered sifnificantly less than 1.0%. It must be content of ash is less than 6.0%, Content of acid-nonsoluble ash is less than 1.0%. A fixed quantity of paeonol is more than 2.5%. Contens of heavy metal has to detect less than 30 ppm and there is no reminding agriculural medince.

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A Model of Work Breakdown Structure for being applied to Historical Data in BTL Project for Educational Facilities (교육시설 BTL 사업의 실적공사비 적용을 위한 작업분류체계(WBS) 구축)

  • Kim, Sung-Kyum;Cho, Chang-Yeon;Son, Jae-Ho;Kim, Jae-On
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2007.11a
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    • pp.499-502
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    • 2007
  • The government abolished the existing method to calculate the construction price by the quantity take-off and pricing. It has introduced a new estimating system which uses the actual cost data on the basis of actual contract unit price. However, in the case of the current method to calculate the estimate price of BTL educational facilities, it is difficult to prepare an accurate ground for calculating unit prices due to a lack of standardized work breakdown structure (WBS) and guidelines for the detailed bidding documents. Thus, this research aims to establish WBS using the actual construction price on the basis of the actual bidding documents for the previous construction of BTL educational facilities. This specific WBS can be differentiated from the general WBS which is not suited for construction of the educational facility. It makes possible to build the construction information classification system and it helps to systemize the maintenance and repair cost items.

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