• 제목/요약/키워드: Change order

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Feature Selection을 활용한 해외 건설의 공사변경 관리에 관한 연구 - 중동 플랜트 건설프로젝트를 중심으로 - (A Study on Change Orders in Overseas Construction using Feature Selection - Focus on Plant Construction in the Middle East -)

  • 홍선영;염춘호
    • 한국건설관리학회논문집
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    • 제22권2호
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    • pp.63-71
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    • 2021
  • 국내 기업의 해외 건설 수주는 지속적으로 성장하고 양적성장을 이루어왔지만, 2011년 유가하락에 이어 최근 COVID-19의 장기화 등 대외환경의 불확실성이 커지며 해외 건설 시장의 침체가 전망된다. 이에 4차 산업혁명의 발전된 기술을 활용해 그간 축적된 데이터를 연구한다면, 향후 해외 건설사업 관리의 역량 및 경쟁력을 키울 수 있을 것이다. 따라서 이 연구에서는 중동 건설시장에서 공정지연과 주요 분쟁의 원인으로 대두되고 있는 공사변경의 상향된 프로젝트 관리 방안을 제시하고자 하였다. 우선 실제 해외 플랜트 건설사례를 분석하여 6가지 주요 공사변경 원인을 도출하였고, 이에 따라 영향을 받는 요인을 8가지로 분류하였다. 특히 머신러닝 기반의 다양한 Feature Selection 기법을 활용해 중요도를 계량화된 수치를 평가함으로써 공사변경과 영향 요인 사이의 유의미한 관계를 파악 하였다. 이를 통해 프로젝트 관리 측면에서 내부적으로는 공사변경의 명확한 관리 방향 수립이 가능하고, 대외적으로는 협상 기간 단축으로 추가적인 공기 지연을 방지하고 비용지출 관리가 가능할 것이라고 판단된다.

A New Control Method for an Adaptive Noise Canceller Using Stochastic difference between Voice and Noise Signals Power Change

  • Nishi, H.;Kakinoki, T.
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.2362-2367
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    • 2005
  • This paper reports a technique for discriminating double talk and echo path change using the stochastic characteristics of power change for an adaptive noise canceller. The causes of rapid error increasing are double talk and echo path change. When the echo path is changed, the system corrects the impulse response in order to reduce the error. However, in the case of double talk, the system has to suspend the updating impulse response in order to maintain the quality of the voice signal. In the conventional system, it was difficult to discriminate between the two situations. In this research, the stochastic characteristics of the voice power change in the double talk period were experimentally verified to be different from the power change during echo path changing. Based on the results, a new double talk detection method is proposed.

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Measuring the Impact of Change Orders on Project Performances by Building Type

  • Juarez, Marcus;Kim, Joseph J.
    • 국제학술발표논문집
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    • The 9th International Conference on Construction Engineering and Project Management
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    • pp.179-187
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    • 2022
  • The project performances can be measured in terms of meeting the project schedule, budget, and conformance to functional and technical specifications. Numerous studies have been conducted to examine the causes and effects of change orders for both vertical and horizontal construction, respectively. However, these studies mainly focus on a single project type, so this paper examines the impact of change order for cost growth and schedule overruns using four different building types to close the gap in the change order research area. A total of 211 building projects are collected from four building types: healthcare, residential, office, and education. Statistical analyses using ANOVA tests and linear regression models are used to examine the created metric $CO/day on the cost and schedule impacts. The results found that mean $CO/day values were not statistically different among building types, and that the sum of change orders is a statistically significant predictor of $CO/day. The results will help project stakeholders mitigate the negative change orders effects can be a challenge for project managers and researchers alike.

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ANALYZING CAUSES OF CHANGE ORDERS IN KOREA ROAD PROJECTS

  • Kang-Wook Lee;Wooyong Jung;Seung Heon Han;Byeong-Heon Yoon
    • 국제학술발표논문집
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    • The 3th International Conference on Construction Engineering and Project Management
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    • pp.1283-1287
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    • 2009
  • The Korean government implemented 259 road projects from 2004 to 2007, valued at $18.4 billion. Change orders of these road projects occurred 8,973 times and, subsequently, caused significant increases in the cost of the projects, approximately up to $4.2 billion (22.8% of the initial budget). These significant problems of huge change orders require a more workable control system for budget management whereas the effectiveness of the government's control is still not satisfied. However, previous approaches and studies mostly limited their analyses to simply classifying the causes of the change orders. This paper investigates the real frequency and cost impacts incurred by each cause of a change order, primarily based on 218 road projects in Korea. The paper then identifies the attributes of change orders through a survey of 204 project participants in that those sources were inevitable or avoided if properly managed. The causes of the change orders are further analyzed with analysis of variance (ANOVA) in connection with contract volume, bid award rate, the contractor's capacity to perform, and the design company's capacity. This study found that if the contract volume is smaller, then the possibility of change orders is higher. Interestingly, if the bid award rate is less than 67.5%, it signifies the highest rate of change orders. In addition, the contractors whose construction ability is assessed as the top-ranked group showed the lowest change order rates. With these results, this paper provides the preventive guidelines for reducing the likelihood of change orders.

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Brassiere 착용조건에 따른 신체의 형태적, 생리적 변화에 관한 심리적 연구 (A Experimental Study on the Formal and Physiological Change of Body according to the Wearing-Brassiere Condition.)

  • 박영득
    • 대한가정학회지
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    • 제29권1호
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    • pp.27-35
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    • 1991
  • This study was carried out to investigate the influence of the various physiological function caused by brassiere wearing. The four experimental methods used in this study are as follows. For example, the Roentgen photographing, Body measurement by Sliding Gauge, the measurement of the Electrocardiogram and Blood Pressure. The results of the Electrocardiogram and Blood Pressure. The results of the investigation were as follows: 1. In experimental change by Sliding Gauge and Body measurement, The bust point was rised in order AB1>B2. The width of right and left bust point was decreased in order of A>B1>B2. According to, The supplementary effect of brassiere wearing was excellent in B2. 2. In the change of various organs by Roentgen photographing, The width of the chest and size of the heart were decreased in regular order of A>B1>B2. The diaphragm and the others were not showed change. 3. In the experimental result by measurement of the electrocardiogram, The interval of heart palpitation was decreased in order A>B1>B2 and the pulse frequency was similar. 4. In the experimental result by the blood pressure measurement, A had the highest blood pressure and B2 had the lowest pressure in all variables.

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18세기 미 조성과 프랑스 두발양식의 유사성 연구 (A Study of Similarity between hair Styles of Chosun and france at the End of Eighteenth century)

  • 구남옥
    • 복식
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    • 제42권
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    • pp.207-222
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    • 1999
  • This study is a thesis based on the fact that at the end of eighteenth century similar change in hair style appeared in Chosun and France which are located very far almost the opposite side of the earth. We can see that very exaggerated and big hair styles of those days in both countries became exceptionally reduced and changed to practical shapes through (an order prohibiting to make large hair style using wigs) is case of Chosun and through the France Revolution in case of France. Outwardly the abobe mentioned change may seem to be caused by such brave and outward convention as the prohibition order and the revolution. however I think that more basic cause of such change from big and splendid hair styles of those days to simple styles was because of many people's sympathy with the necessity of improving various social and economical problems caused by the luxurious and even prodigal situation of those days before the change and additionally because of such pragmatic thought as Positivism of chosun and illuminism of france. In case of france the change in hair style occurred for such a short period of time around the France Revolution(1789) that we can even that the change occurred in a day. However in case of Chosun such change became fixed at the time of king Suncho prohibiting to make large hair style using wigs (1756-1788) was announced. in case of France such change in hair style was mainly because of change of thought caused by people's self-consciousness. But in case of Chosun under the situation where common people's way of thinking about sumptuous moods and beauty was not changed unvoluntary and compulsory change was asked by the King's order so a lot of time seemed to have been necessary for the change in hair style to become fixed as a nationwide common and general custom.

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Influence of Climate Change on the Lifecycle of Construction Projects at Gaza Strip

  • El-Sawalhi, Nabil;Mahdi, Mahdi
    • Journal of Construction Engineering and Project Management
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    • 제5권2호
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    • pp.1-10
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    • 2015
  • There is a high confidence based on scientific evidence that climate is changing over time. Now climate change is considered as one of the challenges facing the construction industry. As no project is risk free and climate change has a strong impact on the different phases of the construction project lifecycle. This research aimed at providing a platform of knowledge for the construction management practitioners about the impacts of climate change on the construction projects lifecycle, identify the most dangerous climate change factors on the construction project lifecycle, and identify the most affected phase by climate change factors through the construction projects lifecycle. The study depended on the opinions of civil engineers who have worked in the construction projects field among the reality of Gaza Strip. Questionnaire tool was adopted as the main research methodology in order to achieve the desired objectives. The questionnaire included 127 factors in order to obtain responses from 88 construction practitioners out of 98 representing 89.79% response rate about the influence of climate change on the generic lifecycle of construction projects. The results deduced that the most significant influence on the construction project lifecycle was related to the extreme weather events, rainfall change, and temperature change respectively. There was a general agreement between the respondents that the most affected phase by temperature, rainfall, and extreme weather events is the execution phase. The results also asserted with a high responses scale on the need to alternative procedures and clear strategies in order to face the climate change within construction industry.

Selection of Key Management Targets for Claim Causes through Relational Analysis on the Causes of Change Order Claims

  • Min, Kwang-Ho;Ko, Gun-Ho;Jin, Chengquan;Hyun, Chang-Taek;Han, Sang-Won
    • 국제학술발표논문집
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    • The 7th International Conference on Construction Engineering and Project Management Summit Forum on Sustainable Construction and Management
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    • pp.281-290
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    • 2017
  • As various stakeholders are involved in construction projects, disputes between the parties are more likely to occur, which is a very important issue for the participants in the projects. Claims in construction projects, however, are very complex and thus difficult to manage. In particular, as the cause of a claim in the preceding stage that has not been resolved in a timely manner has an effect on the cause of a claim in the following stage, it is difficult to find a point of compromise regarding a claim caused by the relationship between the causes that occur in the preceding and following stages. In this regard, this study sought to examine the rules for the generation of change order claims, which occur most frequently among the construction claims, and thus to select the key management targets through the analysis of the relationship between the causes of claims arising in the preceding and following stages for the efficient management of claims. It is expected that the use of rules for the generation of change order claims as well as of representative and similar cases will help the construction practitioners in judging claims, considering the relationships among the causes of the claims. Meanwhile, in this study, association analysis was conducted regarding the causes of the occurrence of change order claims in a design-build delivery method, and therefore, it is necessary to verify the effectiveness of the method when applied to other delivery methods.

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설계시공 일괄입찰공사에서 설계변경 클레임요인의 분석에 관한 연구 (A Study on the Analysis of Change Order - Claim in Design-Build)

  • 이상범;황재우
    • 한국건설관리학회:학술대회논문집
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    • 한국건설관리학회 2006년도 정기학술발표대회 논문집
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    • pp.301-304
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    • 2006
  • 국제적으로 자유무역협정(FTA)에 따른 건설시장의 개방으로 인해 계약상의 권익 주장이 일반화되고 있으며 계약당사자들 간의 분쟁이 빈번히 발생하고 있다. 건설산업의 계약조건은 타 산업과는 다른 특수성을 지니므로 각 공사별로 공종, 환경, 주변 여건 등의 특성을 판단하여 별도의 계약 조건을 설정해야 한다. 국내에서도 공사규모의 증대와 복합기능의 요구에 따라 Design-Build의 발주가 확대되고 있으나 이에 적합한 계약규정이 정해져 있지 않고, 일반공사에서 사용되는 공사계약 일반조건의 일부규정에만 따르고 있어 설계변경 시 여러 가지 클레임 요인들이 발생하고 있는 실정이다. 건설시장 개방이라는 현안을 능동적이고 효과적으로 대처하기 위해서는 국제기준에 부합되는 설계변경 관련 건설 계약규정 및 제도 개선이 요구되므로, 본 연구에서는 이를 위한 객관적이며 합리적인 설계변경 클레임 발생요인의 유형분류와 분석을 통하여 정성적인 클레임요인들을 정량화시켜 D/B사업단계별 설계변경 관련 클레임의 주 요인에 대한 구체적인 분쟁 대응방안을 제시하였다.

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화학공장의 변경관리전산시스템(K-MOC) 개발 (Development of Changing Management Software(K-MOC) for Chemical Plant)

  • 권혁면;백종배
    • 한국안전학회지
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    • 제21권1호
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    • pp.72-78
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    • 2006
  • In many chemical plants the change or modification is carried out without proper technical review and hazard analysis, and also without adequate technical staff and procedures for comprehensive monitoring of potential hazards resulting from the change. Such changes sometimes affect to the process safety badly if it is not managed properly. Therefore, in order to prevent major industrial accidents caused by change or modification, and also in order to apply Management of Change procedure easily in the field and minimize economic burden of company caused by plant changes, K-MOC(KOSHA-Management of Change) software has been developed and provided to the chemical industry.