• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.622-624
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• 2015

As uncertain factors are latent in a construction project by nature, a change order occurs frequently. The occurrence of change orders in construction projects conducted during construction phase is known to cause unexpected negative impacts such as cost overrun, schedule delay, quality problem, and claims in the post-process. Thus, an efficient management method is necessary to prevent and minimize change orders during construction phase when they occur frequently. This paper analyzed the causes of change orders and the impact factors that occur during the construction phase of a construction project and suggested a direction for change order database building.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.188-195
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• 2022

Although issuing change orders is a common practice in the construction phase of any project, non-structural utility subcontractors are struggling and seek to find a way to reduce change orders. Therefore, this paper presents the analysis results on change orders to cultivate possible suggestions and solutions on how to reduce or minimize change orders in mechanical, electrical, and plumbing (MEP) works. Change orders in non-structural utility works are analyzed based on six categories such as rerouting and change of location, changes in weight, rejected design by Office of Statewide Health Planning and Development, District Structural Engineer, or the Structural Engineer of Record, unforeseen conditions, changed equipment, and owner-initiated change. The analysis findings showed that rerouting and changing location is the most significant cause, followed by unforeseen conditions. The results not only contribute to the existing body of knowledge on change order research area, but also help MEP contractors reduce the time and cost of change orders.

• 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.

• Journal of the Korean Data and Information Science Society
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• 제18권4호
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• pp.963-972
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• 2007

When a control chart signals that a special cause is present, process engineers must initiate a search for and an identification of the special cause. Knowing the time of the process change could lead to identify the special cause more quickly, and to take the appropriate actions immediately to improve quality. In this paper, we propose the maximum likelihood estimator (MLE) for the process change point when a control chart is used in monitoring the parameters of a process in which the observations can be modeled as a first-order autoregressive(AR(1)) process plus an additional random error.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 추계 학술논문 발표대회
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• pp.137-138
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• 2017

Generally, a lot of reinforcements are used in nuclear power plant concrete structures in order to improve the structural safety, but it may cause several potential problems due to the overcrowded reinforcement, such as the degradation of concrete quality, the construction delay and the increase of construction cost. In order to resolve these problems, structural test researches and code change studies on using high-strength reinforcement (Gr.80) in unclear power plant structures are under way, and there is good progress in code change of ASM BPVC.III.2 and ACI 349. This purpose of this study is to review the code change status ASM BPVC.III.2, ACI 349 under way to use the high-strength reinforcement in nuclear power plant structures. Also I will introduce the design optimization of NPP structures with high-strength reinforcements in order to maximize the effect and minimize the problem when using the high-strength reinforcements in NPP structures.

• 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.

• 한국운동역학회지
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• 제16권3호
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• pp.183-188
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• 2006

This research is to know differentiation of CP(center of pressure) pattern among four pitching sort(straight ball, raise ball, change up ball, drop ball). Subject are three national or junior athletes. We use the one camera, Novel Win pressure measurement system. Conclusions are as follows : 1. When we throw the straight ball, CP of left foot is effective to end movement at middle of foot in body balance on arm angular motion and enhanced speed. 2. When we throw the raise ball, to change CP from middle to post is more effective in order to raise the ball. 3.In drop ball pitching, in order to fall down the ball in front of hitter, CP of left foot move from post foot to interior part of forefoot 4. In change up ball pitching, if CP of left foot move into forefoot, it is a cause of high ball and hitter can recognize the change up ball because of late arm rotation motion.

• Safety and Health at Work
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• 제12권4호
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• pp.505-510
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• 2021

Background: Factors related to root causes can cause commonly occurring accidents such as falls, slips, and jammed injuries. An important means of reducing the frequency of occupational accidents in small- to medium-sized enterprises (SMSEs) of South Korea is to perform intensity analysis of the root cause factors for accident prevention in the cause and effect model like decision models, epidemiological models, system models, human factors models, LCU (life change unit) models, and the domino theory. Especially intensity analysis in a robot system and smart technology as Industry 4.0 is very important in order to minimize the occupational accidents and fatal accident because of the complexity of accident factors. Methods: We have developed the modern cause and effect model that includes factors of root cause through statistical testing to minimize commonly occurring accidents and fatal accidents in SMSEs of South Korea and systematically proposed educational policies for accident prevention. Results: As a result, the consciousness factors among factors of root cause such as unconsciousness, disregard, ignorance, recklessness, and misjudgment had strong relationships with occupational accidents in South Korean SMSEs. Conclusion: We conclude that the educational policies necessary for minimizing these consciousness factors include continuous training procedures followed by periodic hands-on experience, along with perceptual and cognitive education related to occupational health and safety.

• 대한안전경영과학회지
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• 제8권1호
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• pp.85-96
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• 2006

The oriental life change unit(LCU) models differ from the western LCU model in human behavior, life style, ideas, culture, and psychology factors. Especially, the cause and effect models by behavior scientific approach method have provided the accident proneness concept through the LCU factors. Therefore this paper describes the analytical results of the oriental LCU model and western LCU model. Especially, the death of parents and death of close friend in Korean LCU model feel more acute stress than the western factors. In the case of Korean LCU models between the unmarried and married workers living in the middle area of Korea, death of parents, change in family member's health, change to different line of work, and change in work hours and condition are significant at the significance level of 5%. The priority of life change factors in these models is approved in the order of death of parents, death of spouse, death of close family member, and death of close friend. Finally, the result of this paper can be easily used in order to minimize the industrial accidents by the job stress with the worker and safety manager in real fields.

• 문화기술의 융합
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• 제7권4호
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• pp.879-892
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• 2021

수주생산 환경에서 제조업체의 견적정보는 다양한 고객요구에 대응하여, 프로젝트의 입찰, 수주, 그리고 생산할 제품의 기초정보로 사용하는 중요한 정보이다. 이 견적정보는 고객요구, 제품생산 환경의 변화, 기술제휴사의 도면정보 변경, 그리고 제품의 기술 개선 등의 여러 요인에 의해 변경된다. 이러한 변경으로 인하여, 제조사가 고객의 요구사항을 반영하여 작성중인 견적정보에 다양한 변경이 발생한다. 이러한 다양한 변경요인에 따른 견적정보의 변경은 수주생산 기업의 입장에서 견적관리업무에 많은 부담을 주고 있다. 특히, 견적의 변경요인으로 인한 견적정보 변경은 고객중심의 주문생산 환경에서 고객의 요구사항에 의해 불가피하고 빈번하게 발생한다. 본 논문에서는 견적생성 프로세스를 기준으로 견적변경 프로세스를 제시하고, 일관적이고 효율적인 견적변경처리 방안을 제시하고자 한다. 이를 위하여, 견적의 변경이 발생하는 요인을 정의하고, 각 요인에 대한 변경유형을 정의하였다. 그리고 견적변경에 대한 발생 요인별 사례를 통하여 견적변경 프로세스가 견적관리시스템에 적용되는 과정을 보여준다. 또한 제안된 견적변경 요인, 견적변경 유형, 견적변경 프로세스, 그리고 견적체계 관리의 유용성을 보여주기 위하여, 고객 중심의 수주생산기업인 'H'사의 선박엔진 부문의 통합 견적관리시스템에서의 견적변경처리 기능 및 절차에 적용하였다. 그 결과, 견적변경 요인에 따른 견적변경 처리 및 관리가 효율적으로 수행됨을 확인하였다.