• 제목/요약/키워드: Assembly Work

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Green Bonds Driving Sustainable Transition in Asian Economies: The Case of India

  • PRAKASH, Nisha;SETHI, Madhvi
    • The Journal of Asian Finance, Economics and Business
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    • 제8권1호
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    • pp.723-732
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    • 2021
  • On September 25, 2015, 193 countries of the United Nations (UN) General Assembly, signed the 2030 Agenda to work towards attaining 17 Sustainable Development Goals (SDGs) and its associated 169 targets and 232 indicators. With one of the largest renewable energy programs, India is well-poised to be a role model for low-carbon transformation to other Asian countries. However, bridging the financing gap is critical to ensure that the country meets its SDG targets. Though the SDGs identified by the UN are broad-based and interdependent, for ease of analysis we have grouped them into five themes - people, planet, prosperity, peace, and partnership - based on existing UN models. This paper investigates the financing gap for 'green' projects linked to planet-related SDG targets in India. It builds an argument for utilizing green bonds as an instrument to bridge the gap. After establishing the potential of green bonds in raising the finance to meet India's planet-related SDG targets, we look at the current policy landscape and suggest recommendations for successful execution. The paper concludes that deepening of the corporate fixed income securities market and firming up guidelines in line with India's climate action plans are inevitable before green bonds can be considered a viable financing option.

Machine Learning Methodology for Management of Shipbuilding Master Data

  • Jeong, Ju Hyeon;Woo, Jong Hun;Park, JungGoo
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제12권1호
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    • pp.428-439
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    • 2020
  • The continuous development of information and communication technologies has resulted in an exponential increase in data. Consequently, technologies related to data analysis are growing in importance. The shipbuilding industry has high production uncertainty and variability, which has created an urgent need for data analysis techniques, such as machine learning. In particular, the industry cannot effectively respond to changes in the production-related standard time information systems, such as the basic cycle time and lead time. Improvement measures are necessary to enable the industry to respond swiftly to changes in the production environment. In this study, the lead times for fabrication, assembly of ship block, spool fabrication and painting were predicted using machine learning technology to propose a new management method for the process lead time using a master data system for the time element in the production data. Data preprocessing was performed in various ways using R and Python, which are open source programming languages, and process variables were selected considering their relationships with the lead time through correlation analysis and analysis of variables. Various machine learning, deep learning, and ensemble learning algorithms were applied to create the lead time prediction models. In addition, the applicability of the proposed machine learning methodology to standard work hour prediction was verified by evaluating the prediction models using the evaluation criteria, such as the Mean Absolute Percentage Error (MAPE) and Root Mean Squared Logarithmic Error (RMSLE).

양형 튜블러 샤프트 요크 적용 가변 슬라이딩 중간축 모듈의 토크 변경에 따른 응력 분포 특성 (The Effect of Torque Variation on the Stress Distribution Characteristics in A-IMS Module with both Side Tubular Shaft Yoke)

  • 염진섭;서현규
    • 한국기계기술학회지
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    • 제20권6호
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    • pp.901-905
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    • 2018
  • The objective of this study is to investigate the effect of torque variation on stress distributions in A-IMS module with both side tubular shaft yoke by numerically. In order to achieve this, the torque value was increased from 10Nm to 40Nm, and the results of this work were confirmed in terms of Von-mises Stress and the displacement characteristics. As the torque in module assembly was increased, the stress in tubular shaft york and splined shaft york was increased linearly. The indentation due to the steel ball was occurred in over $40N{\cdot}m$ torque which is over the yield strength condition. The largest displacement occurred in the tubular shaft yoke 1, however, it does not exceed the yield strength and is supposed to be restored due to the elasticity. Therefore, it was concluded that there is no problem for the manufacturing of A-IMS with both side tubular shaft yoke.

Study on Standardization Methods for Reducing Revision Rate of Hull Production Design

  • An, Tae-Hyun;Lee, Tak-Kee
    • 한국해양공학회지
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    • 제36권2호
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    • pp.125-131
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    • 2022
  • Structural design for shipbuilding is generally divided into three stages: the basic, detailed, and production designs, of which the production design is the most frequently revised among the three design stages. The revision involved in production design department was approximately 61% of the total 4,211 revision members and approximately 56% of the total 710 revision cases in the survey on the number of design revisions for nine ships. In this study, members and drawings with a high revision rate were investigated, and related design departments were identified. In addition, the work contents of the design department were analyzed to reduce the number of design revisions and three tasks are very frequently revised were selected. A survey was conducted with engineers engaged in the production design, after which, standards were proposed for the method of aggregating bills of materials, to employ macros to calculate the length of members and that of profile input data when reviewing drawings. Via the study, it was determined that the major causes of design revision are simple mistakes by engineers or lack of understanding on structural arrangement of basic members more than intricacies of prior design and high level specification. As a result of applying the proposed standards, it was confirmed that the design revision was reduced by approximately 40%.

Impact of molybdenum cross sections on FHR analysis

  • Ramey, Kyle M.;Margulis, Marat;Read, Nathaniel;Shwageraus, Eugene;Petrovic, Bojan
    • Nuclear Engineering and Technology
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    • 제54권3호
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    • pp.817-825
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    • 2022
  • A recent benchmarking effort, under the auspices of the Organization for Economic Cooperation and Development (OECD) Nuclear Energy Agency (NEA), has been made to evaluate the current state of modeling and simulation tools available to model fluoride salt-cooled high temperature reactors (FHRs). The FHR benchmarking effort considered in this work consists of several cases evaluating the neutronic parameters of a 2D prismatic FHR fuel assembly model using the participants' choice of simulation tools. Benchmark participants blindly submitted results for comparison with overall good agreement, except for some which significantly differed on cases utilizing a molybdenum-bearing control rod. Participants utilizing more recently updated explicit isotopic cross sections had consistent results, whereas those using elemental molybdenum cross sections observed reactivity differences on the order of thousands of pcm relative to their peers. Through a series of supporting tests, the authors attribute the differences as being nuclear data driven from using older legacy elemental molybdenum cross sections. Quantitative analysis is conducted on the control rod to identify spectral, reaction rate, and cross section phenomena responsible for the observed differences. Results confirm the observed differences are attributable to the use of elemental cross sections which overestimate the reaction rates in strong resonance channels.

Identification of Small GTPases That Phosphorylate IRF3 through TBK1 Activation Using an Active Mutant Library Screen

  • Jae-Hyun Yu;Eun-Yi Moon;Jiyoon Kim;Ja Hyun Koo
    • Biomolecules & Therapeutics
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    • 제31권1호
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    • pp.48-58
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    • 2023
  • Interferon regulatory factor 3 (IRF3) integrates both immunological and non-immunological inputs to control cell survival and death. Small GTPases are versatile functional switches that lie on the very upstream in signal transduction pathways, of which duration of activation is very transient. The large number of homologous proteins and the requirement for site-directed mutagenesis have hindered attempts to investigate the link between small GTPases and IRF3. Here, we constructed a constitutively active mutant expression library for small GTPase expression using Gibson assembly cloning. Small-scale screening identified multiple GTPases capable of promoting IRF3 phosphorylation. Intriguingly, 27 of 152 GTPases, including ARF1, RHEB, RHEBL1, and RAN, were found to increase IRF3 phosphorylation. Unbiased screening enabled us to investigate the sequence-activity relationship between the GTPases and IRF3. We found that the regulation of IRF3 by small GTPases was dependent on TBK1. Our work reveals the significant contribution of GTPases in IRF3 signaling and the potential role of IRF3 in GTPase function, providing a novel therapeutic approach against diseases with GTPase overexpression or active mutations, such as cancer.

Thermoelastic eigenfrequency of pre-twisted FG-sandwich straight/curved blades with rotational effect

  • Souvik S. Rathore;Vishesh R. Kar;Sanjay
    • Structural Engineering and Mechanics
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    • 제86권4호
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    • pp.519-533
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    • 2023
  • This work focuses on the dynamic analysis of thermal barrier coated straight and curved turbine blades modelled as functionally graded sandwich panel under thermal environment. The pre- twisted straight/curved blade model is considered to be fixed to the hub and, the complete assembly of the hub and blade are assumed to be rotating. The functionally graded sandwich composite blade is comprised of functionally graded face-sheet material and metal alloy core. The constituents' material properties are assumed to be temperature-dependent, however, the overall properties are evaluated using Voigt's micromechanical scheme in conjunction with the modified power-law functions. The blade model kinematics is based on the equivalent single-layer shear deformation theory. The equations of motion are derived using the extended Hamilton's principle by including the effect of centrifugal forces, and further solved via 2D- isoparametric finite element approximations. The mesh refinement and validation tests are performed to illustrate the stability and accurateness of the present model. In addition, frequency characteristics of the pre-twisted rotating sandwich blades are computed under thermal environment at various sets of parametric conditions such as twist angles, thickness ratios, aspect ratios, layer thickness ratios, volume fractions, rotational velocity and blade curvatures which can be further useful for designing the blade type structures under turbine operating conditions.

Effect of organic solvents on catalyst structure of PEM fuel cell electrode fabricated via electrospray deposition

  • Koh, Bum-Soo;Yi, Sung-Chul
    • Journal of Ceramic Processing Research
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    • 제18권11호
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    • pp.810-814
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    • 2017
  • Proton exchange membrane fuel cells (PEMFCs) are some of the most efficient electrochemical energy sources for transportation applications because of their clean, green, and high efficiency characteristics. The optimization of catalyst layer morphology is considered a feasible approach to achieve high performance of PEMFC membrane electrode assembly (MEA). In this work, we studied the effect of the solvent on the catalyst layer of PEMFC MEAs fabricated using the electrostatic spray deposition method. The catalyst ink comprised of Pt/C, a Nafion ionomer, and a solvent. Two types of solvent were used: isopropyl alcohol (IPA) and dimethylformamide (DMF). Compared with the catalyst layer prepared using IPA-based ink, the catalyst layer prepared with DMF-based ink had a dense structure because the DMF dispersed the Pt/C-Nafion agglomerates smaller and more homogeneously. The size distribution of the agglomerates in catalyst ink was confirmed through Dynamic Light Scattering (DLS) and the microstructure of the catalyst layer was compared using field emission scanning electron microscopy (FE-SEM). In addition, the electrochemical investigation was performed to evaluate the solvent effect on the fuel cell performance. The catalyst layer prepared with DMF-based ink significantly enhanced the cell performance (1.2 A cm-2 at 0.5 V) compared with that fabricated using IPA-based ink (0.5 A cm-2 at 0.5 V) due to the better dispersion and uniform agglomeration on the catalyst layer.

Target Recognition Triggered Split DNAzyme based Colorimetric Assay for Direct and Sensitive Methicillin-Resistance Analysis of Staphylococcus aureus

  • Jin Xu;Dandan Jin;Zhengwei Wang
    • Journal of Microbiology and Biotechnology
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    • 제34권6호
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    • pp.1322-1327
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    • 2024
  • The accurate and rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) holds significant clinical importance. This work presents a new method for detecting methicillin-resistant Staphylococcus aureus (S. aureus) in clinical samples. The method uses an aptamer-based colorimetric assay that combines a recognizing probe to identify the target and split DNAzyme to amplify the signal, resulting in a highly sensitive and direct analysis of methicillin-resistance. The identification of the PBP2a protein on the membrane of S. aureus in clinical samples leads to the allosterism of the recognizing probe, and thus provides a template for the proximity ligation of split DNAzyme. The proximity ligation of split DNAzyme forms an intact DNAzyme to identify the loop section in the L probe and generates a nicking site to release the loop sequence ("3" and "4" fragments). The "3" and "4" fragments forms an intact sequence to induce the catalytic hairpin assembly, exposing the G-rich section. The released the G-rich sequence of LR probe induces the formation of G-quadruplex-hemin DNAzyme as a colorimetric signal readout. The absorption intensity demonstrated a strong linear association with the logarithm of the S. aureus concentration across a wide range of 5 orders of magnitude dynamic range under the optimized experimental parameters. The limit of detection was calculated to be 23 CFU/ml and the method showed high selectivity for MRSA.

국외 오프사이트 건설 관리 연구 동향 : 작업 단계 수준에서의 문헌 연구 (Research Trends in Off-Site Construction Management : Review of Literature at the Operation Level)

  • 장준영;;이찬식;김태완
    • 한국건설관리학회논문집
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    • 제20권4호
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    • pp.114-125
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    • 2019
  • OSC (Off-Site Construction)는 공장 생산 기반의 새로운 건설 방식이다. 생산성과 경제성, 품질면에서 기존 방식에 우위에 있기 때문에 미국, 영국 등 세계 각지에서 OSC 관련 설계 및 생산 표준화, 운반 방법 등과 같은 연구들이 활발하게 진행되고 있다. 새로운 분야의 출현으로 합리적인 관리가 요구됨에 따라 건설사업관리 범위에 대한 분석이 필요한 실정이다. 따라서 이 연구는 CM/PM범위의 "작업 단계 수준"에서 연구 동향 및 관계를 분석하여 연구의 영역, 연구 간 관계, 현재의 연구에서 부족한 부분 등을 파악하였다. 이 연구에서는 2018년 9월3일까지 작업 단계의 수준 94개의 논문으로, OSC (CM/PM)연구에 대한 포괄적인 문헌 검토를 수행하였으며, 분석 결과 다음과 같다. (1) 2006년부터 작업 단계 수준의 연구가 빠르게 증가하고 있다. (2) Non-volumetric pre-assembly유형은 작업 단계에서 가장 크게 기여하고 있다. (3) 건축물 유형에서는 주거용: 주거의 생활, 품질 문제, 비주거: 경제 문제, 공장: 생산성 문제를 다루는 것으로 확인되었다. (4) Non-volumetric pre-assembly 유형은 주거용 및 비주거용 건축물에서 경제성에 대한 내용을 다루고 있었으며, 반면, Modular building 유형은 조립 품질에 관련된 연구가 수행되었다. (5) 2006년부터 프로젝트 관리 영역(예 : 품질, 인적 자원, 위험)이 확장되었다. 이 연구를 활용하면 OSC 새로운 연구 영역을 찾는데 도움이 될 것으로 예상된다. 추후 산업, 기업, 프로젝트 단계 수준까지 분석을 진행한다면, OSC 산업의 전반적인 연구 흐름 및 분야별 영역을 파악할 수 있을 것으로 판단된다.