• Korean Journal of Construction Engineering and Management
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• 제22권2호
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• pp.63-71
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• 2021

This paper looks into how to enhance construction project management, focusing on the change order, which is often considered one of the major causes for construction delays, disputes, and claims in the middle east construction. First, this paper categorizes the major causes of change orders. It suggests a detailed classification standard for affecting factors resulting from change orders based on a case study result of an on-going construction project in the Middle East. In particular, this paper presents a method to apply a machine learning-based feature selection to quantify the importance of change order triggers and affecting factors. As a result, the case study identifies six major change order triggers and eight affecting factors. Also, a meaningful relationship between change order triggers and affecting factors by each category is presented. This paper will contribute to setting a clear guideline for change order management for the international plant construction field while helping prevent construction delays and cost run-ups by reducing the time required for change order resolution between project owners and contractors.

• 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.

• International conference on construction engineering and project management
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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.

• International conference on construction engineering and project management
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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.

• Journal of the Korean Home Economics Association
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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.

• Journal of the Korean Society of Costume
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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.

• 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.

• International conference on construction engineering and project management
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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.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 한국건설관리학회 2006년도 정기학술발표대회 논문집
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• pp.301-304
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• 2006

The insistence of rights and interests in contract is being generalized by opening in construction market which is following F.T.A, internationally. Conditions of contract in construction have different specialities compared with other industries. Different conditions of contract should be established because of a specific character that is different from each construction, such as work, environment, circumference conditions. Although the order of Turn-key is being expanded by increasing construction scale and demanding hybrid function, the suitable regulations of contract are not settled. As a result, various factors of claim is occurring in Change Order-Claim, because they just obey a part of guide-line. This study suggests useful solutions in detail concerned with the main factor of Change Order-Claim by each D/B phases through practical sorting and analysis of the causes of Change Order-Claim.

• Journal of the Korean Society of Safety
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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.