• Title/Summary/Keyword: feature construction

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A Case Study of the Improvement of the Structural Work of a Logistics Facility by Using PC Member (PC부재에 의한 물류시설의 골조공사 개선사례 연구)

  • Kim, Seon-Hyung;Choi, Eun-Gyu;Kim, Sun-Kuk;Lee, Sung-Ho
    • Journal of the Korea Institute of Building Construction
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    • v.10 no.6
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    • pp.127-135
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    • 2010
  • As logistics facilities have a high ceiling height, simple structure, and the need for a quick return on investment, it is usually essential to advance the construction schedule of such facilities. Accordingly, PC structures, which require less labor, cost and schedule, can be more competitive than RC structures. However, most construction companies in Korea are familiar with RC structure design, have negative perceptions regarding PC structures, and do not sufficiently adopt new construction techniques. The structure that this research features has 110 columns that are 14 m high and are built to the same specification, and applying an RC design to the structure will lead to issues related to constructibility, economic viability, project duration and safety. Therefore, this study intends to feature PC design as an alternative to the RC warehouse design, and perform a comparative analysis of the reduction in labor, cost and construction schedule to highlight benefits. The research outcomes herein will provide inputs to subsequent studies on new construction strategies to advance the construction schedule, improve quality and constructibility, enhance safety and save costs.

Analysis of Environmental Factors Affecting on the Physiological Characteristics of Heterotrophic Bacteria in Naktong River Estuary (낙동강 하구생태계의 환경변화에 따른 종속영양세균의 생리학적 특성)

  • 권오섭
    • Korean Journal of Microbiology
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    • v.30 no.3
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    • pp.193-198
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    • 1992
  • Environmental parameters and physiological characteristics of heterotrophic bacterial isolates were compared by factor analysis to investigate the influences of river barrage construction on the ecosystem of Naktong River Estuary. Aftcr the construction of river barrage, the influence of seawater was no longer significant. ant1 the influences of nutrients loading were increased from 50.7% to 77.1% of the environmental variances before and after the construction, respectively. The interpretations of features of bacterial physiological characteristics were closely related to environmental parameters as the results of factor analysis. But. differing from the environmental variances. it was found that the halophilic feature was the third factor of bacterial characteristics after the construction of river barrage. This suggests that the stability of Naktong estuarine ecosystem and heterotrophic bacterial characteristics are not established till now.

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Transformation characteristics of stylobate and staircase of post-lintel Construction of Backje and Silla Style (백제계 및 신라계 가구식 기단과 계단의 시기별 변화특성)

  • Nam, Chang-Keun;Kim, Tai-Young
    • Journal of architectural history
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    • v.21 no.1
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    • pp.99-118
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    • 2012
  • This study aims to classify the architectural formation of the Stylobate of and Staircase types of Post-Lintel Construction in Backje style and Silla style and also to figure out their specific elements by periods and transformation characteristics. The scope of this study was restricted to architectural remains between the Three Kingdom period and the Goryeo period. To progress the investigation, the study classified remains in a similar type by period and type, and then and analyzed its character based on formation method and specific factors of subsidiary materials. As a result, its type can be classified as Backje type(I), Silla type(II) and Mixed type(III). Regionally, it is found that Woongjin, Sabi and surroundings in the capital of Backje, Gyeongju and main towns in the capital of Silla, and Gaeseong and main towns in the capital of Goryeo. In particular, type III has the characteristics of type I and II simultaneously, which has one or two layers Jangdaeseok stone between the foundation stone of stylobate and plate stone, and tends to be decorative when Taengjuseok stone is installed. For types of staircase, it could be classified as 6~7C Backje type(I), 7~9C Silla type(II) and 9C Mixed type(III) according to the formation method of Somaetdol (banister of stone stair). And from the 9th century on, decorated Somaetdol stone type(IV) of 1/4 circle shape began to appear. The common feature of stylobate of post-lintel and staircase is that it became simplified, abbreviated and decorative. It seems to be intended to secure simplicity of construction or structural stability.

A Research Study on Construction Field Worker's Working Uniform (건설현장 근로자의 작업복 실태조사)

  • Kim, Seong-Suk;Kim, Hee-Eun
    • The Korean Fashion and Textile Research Journal
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    • v.8 no.2
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    • pp.203-208
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    • 2006
  • The purpose of this study is to examine the ergonomic working uniform. Developing a prototype uniform will be the first stage in aiming to create a working uniform in the construction field. This study was conducted using a questionnaire in the construction field of Daegu city, and the data was gathered from 121 questionnaires. Some of the questions that were asked, were about the case of putting on and removing the uniform and if any areas of uniform caused discomfort. The areas of the uniform that caused problems were the waist, knee, shoulder, arm and neck regions. The free range of movement of these regions were restricted and caused the person to feel cramped. The results of the questionnaire called for improvements to the knee, waist, shoulder and crotch area. The prototype that was developed offered more range of movement in the knee and crotch area, while not causing the uniform to be cramped too much during motion. The prototype also improved comfort by raising the waist line of back part, and by having the ability of the uniform to be tightened or loosened with zipper according to the persons preference. The upper area of the uniform was improved by dropping the shoulder seam line which enhanced comfort and also allowed a better fit for the elbow and wrist. The prototypes additional feature included a slit zipper in the sides of the trousers and a gusset in the under arm area to improve breathability and sweat elimination.

Correlation between Building Facade Elements and Defects through "Pixelization Method" (픽셀화기법을 통한 건축물 외벽의 하자와 입면 구성 요소 간의 관계 분석)

  • Kim, Wooram;Jeon, Yongdeok;Shin, Jeongran;Jeong, Kichang;Lee, Jaeseob
    • Korean Journal of Construction Engineering and Management
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    • v.17 no.4
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    • pp.40-48
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    • 2016
  • The construction industry has been made diversified on the design process depending on qualitative growth of customers' demands. But this approach has lead to problems such as falling of building values due to lack of awareness of defects caused by long term utilization. So, the relationship on the characteristics of buildings and defects should be clearly analyzed to prevent falling of building values. This study, therefore, proposed a technique to quantify the relationship between building facade elements and defects. The technique was developed by applying pixel concept to the outside of the buildings. It has a feature to determine the clear relationship by presenting quantitative data that have been recognized qualitatively. The proposed technique is referred to "Pixelization Method". It separates building facade into unit compartment and makes database by assigning a code depending on the characteristics. Through the method, this study is expected to create a foundation for the quantitative analysis of relationship between building facade elements and defects as a basis on active responding to the defects.

Synthesis of High-Aspect-Ratio BaTiO3 Platelets by Topochemical Conversion and Fabrication of Textured Pb(Mg1/3Nb2/3)O3-32.5PbTiO3 Ceramics

  • Zhao, Wei;E, Lei;Ya, Jing;Liu, Zhifeng;Zhou, Heping
    • Bulletin of the Korean Chemical Society
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    • v.33 no.7
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    • pp.2305-2308
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    • 2012
  • Perovskite structured barium titanate particles ($BaTiO_3$) platelets were synthesized by molten salt synthesis and topochemical microcrystal conversion. As the precursors of $BaTiO_3$, plate-like $BaBi_4Ti_4O_{15}$ particles were first synthesized by the reaction of $Bi_4Ti_3O_{12}$, $BaCO_3$, and $TiO_2$ at $1080^{\circ}C$ for 3 h in $BaCl_2$-KCl molten salt. After the topochemical reactions, layer-structured $BaBi_4Ti_4O_{15}$ particles transformed to the perovskite $BaTiO_3$ platelets. $BaTiO_3$ particles with thickness of approximately $0.5{\mu}m$ and a length of $10-15{\mu}m$ retained the morphology feature of the $BaBi_4Ti_4O_{15}$ precursor. For <001> $Pb(Mg_{1/3}Nb_{2/3})O_3-32.5PbTiO_3$ (PMNT)-5 wt % PbO piezoelectric ceramics textured with 5 vol % of $BaTiO_3$ templates, the Lotgering factor reached 0.82, and $d_{33}$ was 870 pC/N.

A Study on the Strength Properties of Green Mortar Using Limestone Powder (석회석(石灰石) 미분말(微粉末)을 이용(利用)한 그린모르타르의 강도(强度) 특성(特性)에 관한 연구(硏究))

  • Jo, Byung-Wan;Choi, Ji-Sun;Kim, Kyung-Tae
    • Resources Recycling
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    • v.22 no.3
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    • pp.36-42
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    • 2013
  • According to the recent community-based structures enlargement, specification, and diversification. It needs appropriate construction materials in terms of intensity and environmental aspects. Thus, in manufacturing the cement using micro limestone powder which is main material. It is also expected to save energies and reduces $CO_2$, by using the blast furnace slag and fly ash which are mitigated environmental load construction materials that emerged. In this research, The durability aspect tries to be grasped considering the chemical property according to the coherence of the hydration product. Consequently, The compressive strength was measured over 30 Mpa on 3rd. In addition, according to the content of the limestone powder, the setting time is promoted. It has the feature expanded in the length change. And it is determined because the possibility of replacing the existing for construction material such as it is measured compared with the time to use the portland cement usually that flexural strength is high with the age 7 days ago, so it is sufficient.

Dimensional Quality Assessment of Steel H-Beams Using Terrestrial Laser Scan Data

  • Mathanraj Rajendran;Sung-Han Sim;Min-Koo Kim;Yoon-Ki Choi
    • International conference on construction engineering and project management
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    • 2024.07a
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    • pp.264-270
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    • 2024
  • In the construction industry, steel structures are prominent due to their exceptional strength and high bearing capacity, making them resilient against natural calamities. However, the stability and overall structural integrity of these steel structures depend significantly on the precision of the individual steel members used. Presently, the dimensions of these steel members are typically measured manually using mechanical instruments such as steel tape and vernier calipers. This conventional approach is not only time-consuming but also highly vulnerable to human error. Consequently, there is a growing need for more accurate and reliable methods for assessing the dimensions of steel members. This paper aims to measure the dimensions of key checklists of the cross-section surface of the steel H-beams using Terrestrial Laser Scan (TLS) data. This study involves the automatic extraction of scan points associated with the cross-section surface of the H-beam members using RANSAC. By the end, an algorithm was developed to predict the actual edge points belonging to the boundary of the extracted surface and introduced an edge loss compensation model to compensate the losses occurred due to uncertainties. Experimental evaluations were conducted using various scan data collected from steel H-beam and the measured dimensions were subsequently compared with manual measurements and dimensions obtained through the previously proposed method, demonstrating that the measurements meet 1mm accuracy and are within the allowable tolerance range followed in industry. This research underscores the efficiency and reliability of the introduced approach, offering a promising solution to enhance the dimensional quality assessment of steel H-beams in the construction industry.

A Construction Method of Expert Systems in an Integrated Environment

  • Chen, Hui
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 2001.01a
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    • pp.211-218
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    • 2001
  • This paper introduces a method of constructing expert systems in an integrated environment for automatic software design. This integrated environment may be applicable from top-level system architecture design, data flow diagram design down to flow chart and coding. The system is integrated with three CASE tools, FSD (Functional Structure Diagram), DFD (Data Flow Diagram) and structured chart PAD (Problem Analysis Diagram), and respective expert systems with automatic design capability by reusing past design. The construction way of these expert systems is based on systematic acquisition of design knowledge stemmed from a systematic design work process of well-matured developers. The design knowledge is automatically acquired from respective documents and stored in the respective knowledge bases. By reusing it, a similar software system may be designed automatically. In order to develop these expert systems in a short period, these design knowledge is expressed by the unified frame structure, functions of th expert system units are partitioned mono-functions and then standardized components. As a result, the design cost of an expert system can be reduced to standard work procedures. Another feature of this paper is to introduce the integrated environment for automatic software design. This system features an essentially zero start-up cost for automatic design resulting in substantial saving of design man-hours in the resulting in substantial saving of design man-hours in the design life cycle, and the expected increase in software productivity after enough design experiences are accumulated.

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The application of a Genetic Algorithm with a Chromosome Limited Life for the Distribution System Loss Minimization Re-configuration Problem (배전손실 최소화문제에서 개체수명을 고려한 유전적 알고리즘의 적용)

  • Choi, Dai-Seub;Lee, Myung-Un;Cho, Taek-Koo;Kim, Jong-Yung;Song, Min-Jong
    • Proceedings of the KIEE Conference
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    • 2002.07a
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    • pp.320-326
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    • 2002
  • Distribution system loss minimization re-configuration is 0-1 planning problem, and the number of combinations requiring searches is extremely large when dealing with typical system scales. For this reason, the application of a genetic algorithm (GA) seems attactive to solve this problem. Although Genetic algorithms are a type of random number search method, they incorporate a multi-point search feature and are therefore superior to one-point search techniques. The efficiency of GAs for solving large combinational problem has received wide attention. Further, parallel searching can be performed and the optimal solution is more easily reached. In this paper, for improving GA convergence characteristics in the distribution system loss minimization re-configeration problem, a chromosome "Limited Life" concept is intro duced. Briefly, considering the population homogenization and genetic drift problems, natural selection is achieved by providing this new concept, in addition to natural selection by fitness. This is possible because individuals in a population have an age value. Simulations were carried out using a model system to check this method's validity.

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