• Title/Summary/Keyword: on-site assembly

Search Result 149, Processing Time 0.03 seconds

Assessment of Quality Assurance in the Lifting and Assembly Phase of Modular Construction: An Importance-Performance Analysis Approach (중요도-성취도 분석을 이용한 모듈러 건축프로젝트 현장설치 및 양중 단계의 품질 관리방안에 관한 연구)

  • Lee, Jeong-Hoon
    • Journal of the Korea Institute of Building Construction
    • /
    • v.23 no.5
    • /
    • pp.595-605
    • /
    • 2023
  • With the escalating prevalence of modular construction projects, there is a concurrent surge in scholarly and industrial intrigue in this domain, leading to a broadened spectrum of its applications. Modular construction, inherently facilitated by controlled factory settings, boasts the capability to consistently deliver edifices of superior quality. To optimize this advantage, the judicious integration of quality assurance methodologies during the site-specific phases of lifting and assembly is non-negotiable. This research embarked on a survey directed at project stakeholders, aiming to gauge the perceived significance and efficaciousness of prevailing quality preservation and oversight protocols during the aforementioned site stages, subsequently employing the Importance-Performance Analysis(IPA) for data interpretation. The findings elucidated that, while a majority of quality assurance procedures were adeptly executed, perceptual disparities existed among stakeholders regarding certain aspects, prompting recommendations for enhancement. This investigative endeavor lays a foundation, aiding future studies in amplifying the quality assurance cognizance among professionals during modular construction's site-assembly phase.

Case of assembly process review and improvement for mega-diameter slurry shield TBM through the launching area (발진부지를 이용한 초대구경 이수식 쉴드TBM 조립공정 검토 및 개선 사례)

  • Park, Jinsoo;Jun, Samsu
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.24 no.6
    • /
    • pp.637-658
    • /
    • 2022
  • TBM tunnel is simple with the iterative process of excavating the ground, building a segment ring-build, and backfilling. Drill & Blast, a conventional tunnel construction method, is more complicated than the TBM tunnel and has some restrictions because it repeats the inspection, drilling, charging, blasting, ventilation, muck treatment, and installation of support materials. However, the preparation work for excavation requires time and cost based on a very detailed plan compared to Drill & Blasting, which reinforces the ground and forms a tunnel after the formation of tunnel portal. This is because the TBM equipment for excavating the target ground determines the success or failure of the construction. If the TBM, an expensive order-made equipment, is incorrectly configured at the assembly stage, it becomes difficult to excavate from the initial stage as well as the main excavation stage. When the assembled shield TBM equipment is dismantled again, and a situation of re-assembly occurs, it is difficult throughout the construction period due to economic loss as well as time. Therefore, in this study, the layout and plan of the site and the assembly process for each major part of the TBM equipment were reviewed for the assembly of slurry shield TBM to construct the largest diameter road tunnel in domestic passing through the Han River and minimized interference with other processes and the efficiency of cutter head assembly and transport were analyzed and improved to suit the site conditions.

Prevalence of Work-related Musculoskeletal Disorders in Auto-mission Assembly Plant Workers

  • Min, Seung Nam;Subramaniyam, Murali;Kim, Dong-Joon;Park, Se Jin;Lee, Heeran;Lee, Ho Sang;Kim, Jung Yong
    • Journal of the Ergonomics Society of Korea
    • /
    • v.34 no.4
    • /
    • pp.293-302
    • /
    • 2015
  • Objective: This study was performed to investigate the prevalence of musculoskeletal disorders in auto workers of a mission assembly plants. Background: Most studies of musculoskeletal disorders have used car assembly line workers as their participants. However, little research has been done on musculoskeletal disorders afflictions of mission assembly line workers. Method: Through a focus group interview with an ergonomist and a manager at a mission assembly plant site, a questionnaire was developed for musculoskeletal disorders. The questionnaire consisted of five parts, demographic factors, musculoskeletal disorder symptoms, and musculoskeletal disorder experiences; 137 workers participated in this survey. The surveys were analyzed by correlation and Chi-squared analysis. Results: Musculoskeletal disorder symptoms and serious pain were reported in the neck, shoulder, back, and fingers. These problems were statistically related to various demographic factors, such as age, stature, stretching, and work satisfaction. Conclusion: Treatment of musculoskeletal disorders should consider the workers' traits. If there is no specific cause of the pain, developing stretches and exercises before and after work should be applied to prevent musculoskeletal disorders. Application: The results of this study can be used to develop guidelines to prevent injury in auto workers at mission assembly plants.

Structural and Biochemical Studies Reveal a Putative FtsZ Recognition Site on the Z-ring Stabilizer ZapD

  • Choi, Hwajung;Min, Kyungjin;Mikami, Bunzo;Yoon, Hye-Jin;Lee, Hyung Ho
    • Molecules and Cells
    • /
    • v.39 no.11
    • /
    • pp.814-820
    • /
    • 2016
  • FtsZ, a tubulin homologue, is an essential protein of the Z-ring assembly in bacterial cell division. It consists of two domains, the N-terminal and C-terminal core domains, and has a conserved C-terminal tail region. Lateral interactions between FtsZ protofilaments and several Z-ring associated proteins (Zaps) are necessary for modulating Z-ring formation. ZapD, one of the positive regulators of Z-ring assembly, directly binds to the C-terminal tail of FtsZ and promotes stable Z-ring formation during cytokinesis. To gain structural and functional insights into how ZapD interacts with the C-terminal tail of FtsZ, we solved two crystal structures of ZapD proteins from Salmonella typhimurium (StZapD) and Escherichia coli (EcZapD) at a 2.6 and $3.1{\AA}$ resolution, respectively. Several conserved residues are clustered on the concave sides of the StZapD and EcZapD dimers, the suggested FtsZ binding site. Modeled structures of EcZapD-EcFtsZ and subsequent binding studies using bio-layer interferometry also identified the EcFtsZ binding site on EcZapD. The structural insights and the results of bio-layer interferometry assays suggest that the two FtsZ binding sites of ZapD dimer might be responsible for the binding of ZapD dimer to two protofilaments to hold them together.

Hybrid Fungal Genome Annotation Pipeline Combining ab initio, Evidence-, and Homology-based gene model evaluation

  • Min, Byoungnam;Choi, In-Geol
    • 한국균학회소식:학술대회논문집
    • /
    • 2018.05a
    • /
    • pp.22-22
    • /
    • 2018
  • Fungal genome sequencing and assembly have been trivial in these days. Genome analysis relies on high quality of gene prediction and annotation. Automatic fungal genome annotation pipeline is essential for handling genomic sequence data accumulated exponentially. However, building an automatic annotation procedure for fungal genomes is not an easy task. FunGAP (Fungal Genome Annotation Pipeline) is developed for precise and accurate prediction of gene models from any fungal genome assembly. To make high-quality gene models, this pipeline employs multiple gene prediction programs encompassing ab initio, evidence-, and homology-based evaluation. FunGAP aims to evaluate all predicted genes by filtering gene models. To make a successful filtering guide for removal of false-positive genes, we used a scoring function that seeks for a consensus by estimating each gene model based on homology to the known proteins or domains. FunGAP is freely available for non-commercial users at the GitHub site (https://github.com/CompSynBioLab-KoreaUniv/FunGAP).

  • PDF

Course Design for Mechanical Engineering Applying Case-Based Learning: Manufacturing of Laminator Machine (사례기반학습법을 적용한 기계공학 교과목 설계: 라미네이터 장비 제작)

  • Ryu, Sun-Joong
    • Journal of Engineering Education Research
    • /
    • v.23 no.5
    • /
    • pp.61-67
    • /
    • 2020
  • In the associate degree curriculum of the department of mechanical engineering, the results of the study are presented on the structure and content of a subject based on the case-based learning method. As an case, equipment called a laminator that is actually used in the manufacturing site was selected. Class deals with specific engineering issues at each stage of laminator manufacturing (design-machining-assembly-measurement-maintenance) in connection with general engineering topics in prerequisites in the curriculum. Topics include tolerance fit, length measurement, assembly practice, measurement design and statistics of machine maintenance, etc. Courses that apply the case-based learning method may be included in the curriculum as complementary roles to those that apply other student-centered learning method.

Ultrasound-Aided Monolayer Assembly of Spherical Silica Nanobeads

  • Yun, Sang-Hui;Yun, Seo-Yeong;Lee, Jin-Seok
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2013.08a
    • /
    • pp.267.1-267.1
    • /
    • 2013
  • In modern science and technology, the organization of building blocks, such as spherical particles and zeolite, is important to form a nanostructure. So, it is essential to develop methods for organizing them into large scale for many precise applications. Up to now, reflux and stirring is widely used method for organization of colloidal particles. However, because this method is hard to organize building block with high coverage and uniform orientation, it is necessary to research another method. In this work, we synthesized spherical silica particles using St$\"{o}$ber method and organized them on the glass which is coated with 3-chloropropyltrimethoxysilane (CP-TMS) and polyethyleneimine (PEI) using Sonication method. Although spherical silica particles are difficult to attach on the glass due to their small attachment site, we improved this problem by coating PEI. We introduced two mode of reaction promotion, sonication (SO) and sonication with stacking between the bare glass (SS), and investigated degree of coverage (DOC) and degree of close packing (DCP).

  • PDF

Layer-by-layer assembled polymeric thin films as prospective drug delivery carriers: design and applications

  • Park, Sohyeon;Han, Uiyoung;Choi, Daheui;Hong, Jinkee
    • Biomaterials Research
    • /
    • v.22 no.4
    • /
    • pp.290-302
    • /
    • 2018
  • Background: The main purpose of drug delivery systems is to deliver the drugs at the appropriate concentration to the precise target site. Recently, the application of a thin film in the field of drug delivery has gained increasing interest because of its ability to safely load drugs and to release the drug in a controlled manner, which improves drug efficacy. Drug loading by the thin film can be done in various ways, depending on type of the drug, the area of exposure, and the purpose of drug delivery. Main text: This review summarizes the various methods used for preparing thin films with drugs via Layer-by-layer (LbL) assembly. Furthermore, additional functionalities of thin films using surface modification in drug delivery are briefly discussed. There are three types of methods for preparing a drug-carrying multilayered film using LbL assembly. First methods include approaches for direct loading of the drug into the pre-fabricated multilayer film. Second methods are preparing thin films using drugs as building blocks. Thirdly, the drugs are incorporated in the cargo so that the cargo itself can be used as the materials of the film. Conclusion: The appropriate designs of the drug-loaded film were produced in consideration of the release amounts and site of the desired drug. Furthermore, additional surface modification using the LbL technique enabled the preparation of effective drug delivery carriers with improved targeting effect. Therefore, the multilayer thin films fabricated by the LbL technique are a promising candidate for an ideal drug delivery system and the development possibilities of this technology are infinite.

An Experimental Study on the Development of Unit Column Wall Form System Using (Focusing on the Lateral Pressure) (기둥식 벽체 거푸집 시스템 개발에 관한 실험적 연구)

  • Kang, Chang-Soo;Lee, Han-Seung;Tae, Sung-Ho
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2005.05a
    • /
    • pp.507-510
    • /
    • 2005
  • Euro form which constructs the present RC structures is used widely by the form method of construction of a wall type structure had much consumption of the human power and equipments by the assembly and the demolition, and the complement was required according to demerit with much leakage of cement paste by the form joint, so it developed the new pillar type form system. On the study, in order to consider the modification characteristic by lateral pressure which does the influence most important for the new developed pillar type form system performance, research of a paper manufactured a miniature wall form model, and advanced performance evaluation focusing on lateral pressure. Moreover, lateral pressure evaluation of a new style system was actually gone on through the on-site experiment about a part of wall type srutcture spot for a model experiment and its result on the foundation which is the purpose in evaluating on-site application possibility propriety at the foundation time of wall type concrete structure construction of a pillar type form system.

  • PDF

Expression, Purification, and Characterization of Iron-Sulfur Cluster Assembly Regulator IscR from Acidithiobacillus ferrooxidans

  • Zeng, Jia;Zhang, Ke;Liu, Jianshe;Qiu, Guanzhou
    • Journal of Microbiology and Biotechnology
    • /
    • v.18 no.10
    • /
    • pp.1672-1677
    • /
    • 2008
  • IscR (iron-sulfur cluster regulator) has been reported to be a repressor of the iscRSUA operon, and in vitro transcription reactions have revealed that IscR has a repressive effect on the iscR promoter in the case of [$Fe_{2}S_{2}$] cluster loading. In the present study, the iscR gene from A. ferrooxidans ATCC 23270 was cloned and successfully expressed in Escherichia coli, and then purified by one-step affinity chromatography to homogeneity. The molecular mass of the IscR was 18 kDa by SDS-PAGE. The optical and EPR spectra results for the recombinant IscR confirmed that an iron-sulfur cluster was correctly inserted into the active site of the protein. However, no [$Fe_{2}S_{2}$] cluster was assembled in apoIscR with ferrous iron and sulfide in vitro. Therefore, the [$Fe_{2}S_{2}$] cluster assembly in IscR in vivo would appear to require scaffold proteins and follow the Isc "AUS" pathway.