• Title/Summary/Keyword: Lean System

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Identifying Wastes in Construction Process and Implementing the Last Planner System in India

  • Bhatla, Ankit;Pradhan, Bulu;Choi, Jin Ouk
    • Journal of Construction Engineering and Project Management
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    • v.6 no.1
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    • pp.11-19
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    • 2016
  • Most of the Indian contractors are not well equipped to handle the growing demand of infrastructure development; hence construction projects frequently run in to time and cost overruns, disputes and quality issues. This study aims to improve the construction industry in India by implementing lean principles to eliminate non-value adding activities (wastes). The purpose of this study is to 1) identify the wastes and their sources affecting the construction process, and 2) to identify problems and document lessons by applying a Last Planner System (LPS) to a sample project. First, the researchers identified that Delays, Rework, and Interruptions were the most critical wastes affecting the construction process and Poor management control, Poor Planning and Shortage of Resources were the major sources of the above mentioned wastes. Second, the researchers report the Percent of Planned Complete (PPC) analysis results and experienced problems after implementation of LPS at the sample project. It was observed that much more improvement could have been achieved if there was consensus between the owners and the contractor on the implementation of the LPS in its entirety. Some of the problems experienced in the implementation of the LPS like lack of scheduling, resource and material shortage were found to be similar to those in developed countries.

A Study of Combustion Instability Mode in Dual Swirl Gas Turbine Combustor by PLIF and Chemiluminescence Measurement (PLIF 및 자발광 계측을 이용한 이중선회 가스터빈 연소기에서 연소불안정 모드 연구)

  • Choi, Inchan;Lee, Keeman;Juddoo, Mrinal;Masri, A.R.
    • Journal of the Korean Society of Combustion
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    • v.19 no.1
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    • pp.29-38
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    • 2014
  • This paper described an experimental investigations of combustion instability mode in a lean premixed dual swirl combustor for micro-gasturbine system. When such the instability occurs, a strong coupling between pressure oscillations and unsteady heat release excites a self-sustained acoustic wave which results in a loud, annoyed sound and may also lead a structural damage to the combustion chamber. The detailed period of flame behavior and heat release in combustion instability mode have been examined with high speed OH and CH-PLIF system and $CH^*$ chemiluminescence measurement, flame tomography with operated at 10 kHz and 6 kHz each. Experiment results suggest that unstable flame behavior has a specific frequency with 200 Hz and this frequency is accords with about 1/2 sub-harmonic of combustor resonance frequency, not fundamental frequency. This is very interesting phenomenon that have not reported yet from other previous works. Therefore, when a thermo-acoustic instability with Rayleigh criterion occurs, the fact that the period of heat release and flame behavior are different each other was proposed for the first time through this work.

Cloud-Based Accounting Adoption in Jordanian Financial Sector

  • ELDALABEEH, Abdel Rahman;AL-SHBAIL, Mohannad Obeid;ALMUIET, Mohammad Zayed;BANY BAKER, Mohammad;E'LEIMAT, Dheifallah
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.2
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    • pp.833-849
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    • 2021
  • Cloud accounting represents a new area of accounting information systems. Past research has often focused on accounting information systems and its antecedents, rather than factors that adopt cloud accounting system. The purpose of this paper is to explain the factors that influence the adoption of cloud accounting in the financial sectors. This paper applied the technology acceptance model (TAM), technology-organization-environment, and the De Lone and Mc Lean model, coupled with proposed factors relevant to cloud accounting. The proposed model was empirically evaluated using survey data from 187 managers (financial managers, IT department managers, audit managers, heads of accounting departments, and head of internal control departments) in Jordanian bank branches. Based on the SEM results, top management support, organizational competency, service quality, system quality, perceived usefulness, and perceived ease of use had a positive relationship with the intention of using cloud accounting. Cloud accounting adoption positively affected cloud accounting usage. This paper contributes to a theoretical understanding of factors that activate the adoption of cloud accounting. For financial firms in general the results enable them to better develop cloud accounting framework. The paper verifies the factors that affect the adoption of cloud accounting and the proposed cloud accounting model.

Study of Combustion Characteristics with Variations of Combustion Parameter in Ultra-Lean LPG Direct Injection Engine (연소제어인자의 변화에 따른 직접분사식 초희박 LPG엔진의 연소특성 연구)

  • Park, Yun Seo;Park, Cheol Woong;Oh, Seung Mook;Kim, Tae Young;Choi, Young;Lee, Yong Gyu
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.6
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    • pp.607-614
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    • 2013
  • Nowadays, automotive manufacturers have developed various technologies to improve fuel economy and reduce harmful emissions. The ultra-lean direct injection engine is a promising technology because it has the advantage of improving thermal efficiency through the deliberate control of fuel and ignition. This study aims to investigate the development of a spray-guided-type lean-burn LPG direct injection engine through the redesign of the combustion system. This engine uses a central-injection-type cylinder head in which the injector is installed adjacent to the spark plug. Fuel consumption and combustion stability were estimated depending on the ignition timing and injection timing at various air-fuel ratios. The optimal injection timing and ignition timing were based on the best fuel consumption and combustion stability.

A Study on Characters of Heart Rate Variability in Young Overweight and Obese Woman (젊은 비만 여성의 심박변이도 특성에 대한 연구)

  • Lee, Yoon-Jae;Hwang, Deok-Sang;Lee, Chang-Hoon;Lee, Kyung-Sub
    • Journal of Korean Medicine for Obesity Research
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    • v.8 no.1
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    • pp.63-70
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    • 2008
  • Objectives Obesity is the major risk factor of the heart disease and the metabolic disease. The autonomic nervous system is a key contributor in the regulation of energy balance, so the blunted activity may contribute to the maintenance of the obese state. So we evaluated the function of the autonomic nervous system in young overweight and obese women with heart rate variability. Methods The subjects were 26 overweight and obese young women(BMI〉$23kg/m^2$) and 25 lean women who visited Kangnam Kyunghee hospital for obesity management from March 2006 to April 2008. Bioimpedance Analysis (BIA), short-term spectral analysis of heart rate variability (HRV) were performed. Results HRV of obese young group was lower than the lean young group, but there is no statistical significance. BMI had significantly a negative correlation with Low Frequency(LF) of HRV. LF power is mediated by sympathetic nervous system activity. These results indicate a decrease of sympathetic modulation in overweight and obese young women. Conclusions Overweight and obese young women have decreased sympathetic nervous system activity. In clinical practice, an assessement of HRV would be noninvasive and sensitive methods for sympathetic nervous system of young overweight and obese women.

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The Method of Improving the Procedure of Time Management for Measuring PPC(Percent of Plan Completed) (작업성취율 측정을 위한 공정관리절차의 개선 방안)

  • Lim, Chul-Woo;Yu, Jung-Ho;Kim, Chang-Duk
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2006.11a
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    • pp.722-726
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    • 2006
  • Last Planner System (LPS) developed by Lean Construction Institute consists of four steps: Master Schedule, Phase Schedule, Lookahead Planning and Weekly Work Plan. This paper focuses on the process of measuring Percent of Plan Completed (PPC) at the Weekly Work Plan stage. PPC means the percentage of weekly assignments completed. According to the results of the researches that deal with PPC from many other countries, we can assure the benefits of using PPC. However, the concept of PPC is unfamiliar in Korea construction industry. This paper analyzes the cases in which PPC is applied in other countries and compares them with the production control system in Korean construction industry. The results of this research will provide the time management system for using PPC in Korea.

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A Successful Example of the PMIS to Dongnam Distribution Complex Project using TPMS(Total Project Management System) of the GS E&C (GS건설 TPMS를 통한 동남권유통단지 이주전문상가 현장 PMIS 성공사례)

  • Lee, Heung-Won;Park, Chan-Jeong
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2007.11a
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    • pp.129-134
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    • 2007
  • In 1996, GS E&C became the first in the industry to adopt a Project Management System using EVM(Earned Value Management) to link schedule with profit/loss. In 2006, the TPMS(Total Project Management System) was completed by adding the concept of Lean Construction and JIT(Just In Time) to the Project Management System. This was done with the purpose of reducing waste and creating optimal work processes. This has been implemented on all sites and has enabled drastic increase of productivity. The portal provides customized information to the client, inspector and subcontractor personnel. Since various parties are receiving information that suits their requirements and is easy to use, usage has increased and since they are on the same platform, quick decisions and information sharing is possible. The purpose of the PMIS's success model in construction projects, this paper tests and proves the TPMS's efficiency and productivity to Dongnam Distribution Complex project.

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Web 2.0 Cluster based Process and Performance Management System Modeling (Web 2.0 Cluster 기반의 공정 및 성과관리 시스템 모델 구축)

  • AHn, Jae-Gyu;Ong, Ho-Kyoung;Kim, Dae-Young
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2007.11a
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    • pp.892-898
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    • 2007
  • This study aims to implement an efficient process management system for small and medium sized(local) construction companies and a performance management system for the Korean construction industry. The process management system by Lean Construction is Web 2.0 platform-based and creates clusters with numerous general contractors and sub-contractors, which will enable mutually organic process management. Plus, this system will enable them to compare project performance management by analyzing it during or after a project by collecting and accumulating lots of data occurring in pursuit of a project. These performance management cases will be of help in process planning during similar upcoming projects. This study is expected to somewhat reduce the burden of implementing a complicated process management protocol and system that Korean small and medium sized (local) construction companies experience with their web-based process management, and is supposed to realize accurate performance management with highly reliable data which are significantly accumulated within the database.

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Introduction to Thermoacoustic Models for Combustion Instability Prediction Using Flame Transfer Function (화염 전달 함수를 이용한 열음향 연소 불안정 해석 모델 소개)

  • Kim, Dae-Sik
    • Journal of the Korean Society of Propulsion Engineers
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    • v.15 no.6
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    • pp.98-106
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    • 2011
  • This paper reviews the state-of-the-art thermoacoustic(TA) modeling techniques and research trend to predict major parameters determining combustion instabilities in lean premixed gas turbine combustors. Linear TA modeling results give us an information on eigenfrequencies and initial growth rate of the instabilities. For the prediction, linear relation equation between acoustic waves and heat release oscillations should be derived in the determined system. Key information for this analysis is to determine the heat release fluctuations in the combustor, which is typically obtained by using n-${\tau}$ function from flame transfer function measurements and/or predictions. Great advancement in the linear TA modeling has been made over a couple of decades, and some successful prediction results have been reported in actual gas turbine combustors. However nonlinear TA model developments which are required to analyze nonlinear system behaviors such as limit cycle saturation and transition phenomena are still limited in a very simple system. In order to fully understand combustion instabilities in a complicated real system, nonlinear flame dynamics and acoustic wave interaction with nonlinear system boundary conditions should be explained from the nonlinear TA model developments.

Guideline for Web 2.0 Cluster based Process and Performance Management System (Web 2.0 Cluster 기반의 공정 및 성과관리 시스템 구축에 따른 운영방안 제시)

  • Ong, Ho-Kyoung;Ahn, Jae-Gyu;Kim, Dae-Young
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2007.11a
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    • pp.899-904
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    • 2007
  • Process management techniques are highly important in the construction industry. However, indicators or details of assessment which will show process management and its performance are still very insufficient. In particular, it is true that local corporations or small and medium sized companies suffer more difficulties than ones in metropolitan areas. Therefore, it is necessary to prepare a flexible process management and performance assessment system suited to field situations. This study identified problems of local small and medium sized companies, implemented a process and performance management system using the Lean concept, and systemized a web-based system. Also, the study proposed operational strategies so that small and medium construction companies may access and use the system easily. This will ensure the competitiveness of local small and medium sized companies, will pursue visible outcomes such as construction period reduction and construction cost reduction, and will be utilized as data related to performance assessment both during construction progress and after construction.

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