• Title/Summary/Keyword: 작업기간

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Fuzzy-MOEH : Resource Constraints Project Scheduling Algorithm with Fuzzy Concept (Fuzzy-MOEH : 퍼지 개념을 이용한 자원제약 프로젝트 스케줄링 알고리즘)

  • Koh, Jang-Kwon;Shin, Ye-Ho;Ryu, Keun-Ho;Kim, Hong-Gi
    • Journal of KIISE:Computing Practices and Letters
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    • v.7 no.4
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    • pp.359-371
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    • 2001
  • Project scheduling under resource constraint conditions have contained to many uncertain factors and it is perfonned by human experts. The expert identifies the activities of the project, decides the precedent relationships between these activities, and then construct the schedule using expected activity's duration. At this time, most of the scheduling methods concentrate on one of scheduling factor between activity duration and cost. And the activity duration, which is the most important factor in scheduling, is decided by heuristic of expert. Therefore it may cause uncertainty of activity duration decision and the use of this activity duration may increase the uncertainty of constructed schedule. This paper proposes Fuzzy-MOEH scheduling algorithm, which is the aggregation of the fuzzy number for deciding activity duration and applies the cost function for solving the problems of previous scheduling methods. This paper also analyze the utility and property of Fuzzy-MEOH algorithm through the comparison between Fuzzy-MEOH algorithm and existing MEOH algorithm.

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Development of Estimation Model of Construction Activity Duration Using Neural Network Theory (건설공사 공정별 작업기간 산정을 위한 신경망 기반 모형 구축)

  • Cho, Bit-Na;Kim, Hyeon-Seung;Kang, Leen-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.5
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    • pp.3477-3483
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    • 2015
  • A reasonable process for the activity duration estimation is required for the successful construction management because it directly affects the entire construction duration and budget. However, the activity duration is being generally estimated by the experience of the construction manager. This study suggests an estimation model of construction activity duration using neural network theory. This model estimates the activity duration by considering both the quantitative and qualitative elements, and the model is verified by a case study. Because the suggested model estimates the activity duration by a reasonable schedule plan, it is expected to reduce the error between planning duration and actual duration in a construction project.

The Estimation of Non-Working days for the Construction Project in Incheon Region (기후요소를 고려한 인천지역의 작업불가능일수 산정)

  • Shin Jong-Hyun;Lee Jin-Ah;Lee Chan-Sik
    • Korean Journal of Construction Engineering and Management
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    • v.6 no.1 s.23
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    • pp.58-64
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    • 2005
  • We should consider climatic factors influencing construction works in order to estimate construction time correctly. This study is to analyze climate elements affecting construction duration and to calculate non-working days far Inchoen territorial region. Through surveying literatures and examining several existing criteria we suggest a Proper criteria for each climate elements which would be used for estimating non-working days. The criteria is made on the raw climate data of Meteorological Administration during the last 30 years(1974-2003) far Incheon region. In case of rainfall, it is estimated as non-working days when daily precipitation is expected more than 10mm, its number of days for Incheon is 29 days. In case of low temperature, the number of non-working days for the concrete works(its criteria be below $4^{\circ}C$ average) and the finishing works(below $0^{\circ}C$ average) is 97 days, 52 days, respectively. In case of high temperature, it is three days when daily highest temperature is expected going over $32^{\circ}C$

Improvement of Non-Working Day Estimation Affected by Weather Conditions in the Construction Projects in Korea (국내 건설공사의 기후조건에 의한 작업불능일 예측방법 개선)

  • Lee, Keun-Hyo;Shin, Dong-Woo;Kim, Kyung-Rai
    • Korean Journal of Construction Engineering and Management
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    • v.7 no.4 s.32
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    • pp.100-108
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    • 2006
  • Non-working days affected by weather conditions of the construction-sites have been estimated without proper data. They are usually estimated based on project engineer's own experience and intuition. As a result, they cause not only economic loss to time-adjustment but also conflicts among project participants. It becomes more difficult to predict the weather nowadays than before due to tendency of recently weather change. Therefore, this paper presents an improved estimation method for non-working days, which could minimize estimation errors. The estimation method is developed based on analysis of regional characteristics and weather conditions which affect project duration.

Effect of Construction Officials' Perception of Risk on Work Environment and Safety Culture (건설관계자의 위험인식이 작업환경과 안전문화에 미치는영향)

  • Kim, Yeon-Gun;Shin, Yeon-Cheol;Moon, Yoo-Mi
    • Proceedings of the Korean Society of Disaster Information Conference
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    • 2023.11a
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    • pp.97-98
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    • 2023
  • 본 연구에서는 건설현장 관계자들을 대상으로 위험인식이 작업환경과 안전문화에 미치는 영향관계를 확인하였다. 또한, 안전관리활동과 공사기간이 안전문화에 미치는 영향을 분석하였다. 주요 결과는 다음과 같다. 첫째, 위험인식은 작업환경에 영향을 미치는 것으로 나타났으며, 둘째, 작업환경은 안전문화에 영향을 미치지 않았다. 셋째, 안전관리 활동은 안전문화에 영향을 미치지 않았으며, 넷째, 공사기간은 안전문화에 영향을 미치는 것으로 분석되었다. 또한, 안전관리 활동과 위험인식 간의 상관관계는 r=.61로, 위험인식과 공사기간은 r=.71로 안전관리 활동과 공사기간의 상관관계는 r=.59로 관계의 강도를 확인하였다.

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Projection of Activity Duration Utilizing Historical Cost Data (자원투입 비용을 고려한 공정관리 작업기간 산정)

  • Moon, Sung-Woo;Kang, Sang-Rae
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2006.11a
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    • pp.444-447
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    • 2006
  • Construction managers need to pay a close attention to the resource utilization in order to deliver the construction project successfully. Construction scheduling is crucial for resource control in that it provides information when and how much to bring down work force to sites. In scheduling, activity duration is projected based on the productivity of historical data or the intuition of scheduler. This paper studies the opportunity of applying cost-based productivity for estimating activity duration. For cost-based productivity, the cost of resource is used as an input and the work quantities as an output. Out of historical data, regression model has been developed to understand the validity of applying cost-based productivity in projecting activity duration. The result of study will work as a prerequisite for implementing the environment of database-based construction scheduling.

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Approximate Estimating of Plant Construction Duration Using a Standard Schedule Model (초기 사업단계에서 표준공정모델을 이용한 가스 플랜트 공사의 개략적 공사기간 산정)

  • Moon, Sung-Woo;Park, Sang-Chun;Kwon, Ki-Nam
    • Korean Journal of Construction Engineering and Management
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    • v.10 no.2
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    • pp.26-33
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    • 2009
  • The required level of detail in scheduling depends on the stages in the construction life-cycle. The objective of this study is to provide a Standardized Schedule Model (SSM) with an aim to facilitate the estimating of construction duration in the planning stage. The SSM modularizes work items; establishes relations between preceding and succeeding activities; and calculates approximate construction duration. The estimated duration of the SSM was compared with the detailed duration from the commercial scheduling tool using actual work activities. The difference showed to be ranged between -3.1% and +15%, which demonstrates that the SSM can be feasibly applied to the approximate estimation of construction duration.

병원 근로자의 요통에 관한 조사

  • Park, Eun-Ok
    • Korean Journal of Occupational Health Nursing
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    • v.2
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    • pp.60-70
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    • 1992
  • 본 연구는 병원 근로자의 요통의 정도와 관련 요인들을 파악하고자 1992년 12월 1일부터 1993년 1월 23일까지 병원근로자 961명을 대상으로 실시되었다. 조사내용은 요통과 요통의 동반증상, 요통의 관련요인인 인구사회학적 특성, 작업특성에 관한 것으로 인구사회학적 특성에는 성, 연령, 근무기간, 직종 등을 포함하였고, 작업 특성에서는 작업강도, 요부의 긴장 요구정도, 작업의 단순성 및 반복성, 물건이나 환자를 운반하는 정도, 밀기와 끌기의 정도, 증상 발생 시 휴식의 가능성 등과 작업 자세를 포함하였다. 자료수집방법은 본 연구자가 개발한 자가보고식 설문지를 이용하였다. 1. 전체 대상자 961명 중 59.5%가 요통을 호소하였으며, 요통호소자의 동반증상으로는'허리의 뻐큰함'이 78.7%로 가장 많았고, '다리가 저리다'가 59.1%였으며, '허리의 운동 장애'가 23.6%, '다리의 감각이상'이 20.3%인 것으로 나타났다. 2. 인구사회학적 특성에 따른 요통호소율을 비교해 본 결과, 첫째, 성별 요통호소율은 유의한 차이를 보였다(p<.05). 둘째, 요통호소군과 비호소군의 두 집단 간 평균연령에 유의한 차이를 보이지 않았으며, 연령별 호소율을 비교하였을 때, 가장 높은 요통호소율을 보인 집단이 25-29세 연령군으로 65.0%였으며, 가장 낮은 요통호소율을 보인 집단은 30-34 세 군으로 53.9%였다. 세째, 근무기간별 요통호소율을 비교해 보면, 10년 미만의 근무기간을 가진 군은 요통호소율에 별 차이를 보이지 않는데 반해, 10-12년 근무기간 군은 55.3%, 13년 이상의 근무기간 군은 47.9%의 요통호소율을 보이고 있어, 장기 근무자가 오히려 낮은 요통호소율을 나타내었다. 그리고 평균 근무기간의 비교에서 요통호소군이 낮은 근무기간을 보이고 있고, 두 집단 간의 차이는 유의하였다(p<.05). 네째, 직종 별로 요통호소율을 보면, 조리보조원(82.2%), 방사선 기사 (67.1%), 물리 치료사(68.2), 간호사(65.9%) 등의 순이었다. 3. 요통호소군과 비호소군의 작업특성을 비교한 결과, 첫째, 요통호소군이 바호소군에 비하여 본인의 작업이 힘들다고 느끼며, 유의한 차이를 보였다(p<.001). 둘째, 요통호소군이 허리의 긴장상태를 많이 요한다고 생각하였으며, 비호소군과 비교하여 유의한 차이가 있었다(p<.001). 세째, 요통호소군이 작업의 단순성이나 반복성을 더 심하게 느끼고 있었고, 유의한 차이를 나타내었다(p<.01). 네째, 요통호소군이 물건이나 환자를 운반하는 일을 더 많이 하는 것으로 나타났으며, 비호소군과 유의한 차이를 보이고 있었다(p<.001). 다섯째, 요통호소군이 비호소군에 비해 밀거나 끄는 일을 더 많이 하고 있는 것으로 나타났으며, 유의한 차이를 보였다(p<.001). 여섯째, 요통호소군에서 증상발생시 휴식이 더 가능하지 않은 것으로 나타났으며, 비호소군과 유의한 차이를 보였다(p<.001). 허리에 부담을 주는 작업의 특성을 전체적으로 파악하기 위하여 위의 여섯항목에 대해 각각 5점을 주어 전 항목의 점수 총합을, 요통이 있는 군과 요통이 없는 군으로 나누어 비교해 보았을 때, 요통호소군은 30점 만점에 24.34(${\pm}4.01$)이었고, 비호소군은 22.05(${\pm}4.18$)이었으며, 이들 두 집단 간에 유의한 차이가 있는 것으로 나타났다(p<.001). 일곱째, 작업 자세에 따른 비교에서 주로 한 자리에 서서 일을 하는 집단이 71.8%로 가장 높았고, 서서 부서 간이나 한 부서 안을 왔다갔다 하는 군이 다음으로 높고, 앉아서 일을 하는 군이 50.3%로 가장 낮았다.

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Probability-based Critical Path Estimation for PERT Networks of Repetitive Activities (반복작업 PERT 네트워크의 확률기반 주공정 산정기법)

  • Yi, Kyoo-Jin
    • Journal of the Korea Institute of Building Construction
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    • v.18 no.6
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    • pp.595-602
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    • 2018
  • Network-based scheduling methods can be classified into CPM method and PERT method. In the network scheduling chart, critical path can be estimated by performing the forward calculation and the backward calculation though the paths in the network chart. In PERT method, however, it is unreasonable to simply estimate the critical path by adding the sum of the activity durations in a specific path, since it does not incorporate probabilistic concept of PERT. The critical path of a PERT network can change according to the target period and deviation, and in some cases, the expected time of the critical path may not be the path with longest expected time. Based on this concept, this study proposes a technique to derive the most-likely critical path by comparing the sum of estimated time with the target time. It also proposes a method of systematically deriving all alternate paths for a network of repetitive activities. Case studies demonstrated that the most-likely critical path is not a fixed path and may vary according to the target period and standard deviation. It is expected that the proposed method of project duration forecasting will be useful in construction environment with varying target date situations.

A Study on Estimating Time for PRD (Percussion Rotary Drill) Piling Work (도심지 토공사 PRD (Percussion Rotary Drill) 공법의 천공작업 소요시간 산정 방안에 관한 연구)

  • Kim, Yong-Gyu;Choi, Chang-Hoon;Han, Choong-Hee;Lee, Junbok
    • Korean Journal of Construction Engineering and Management
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    • v.19 no.3
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    • pp.3-10
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    • 2018
  • In recent years, mechanized construction has become commonplace due to increases in the scale and complexity of construction, and construction machinery is a major factor in successful construction. However, even though the proportion of construction machinery is increasing, analysis of the work capacity of construction machinery is inadequate. In addition, since the standards for all construction machines are currently not defined in quantity-per-unit, the construction period is arbitrarily applied according to the operator at the time of the construction plan. As a result, the construction period of the actual construction is insufficient, and rushed work or construction delays occur. Therefore, in this study, in order to calculate the construction period of the piling work of the pile driver used in the PRD method more accurately than the existing method, the formula for calculating the time required for the piling work of the pile driver was established by collecting piling time data from the daily task reports through the field survey. If the precise construction period of piling work is estimated based on the results of this study, it will be possible to prevent the rushed work and construction delays that occur due to the short construction period.