• 제목/요약/키워드: well completion

검색결과 439건 처리시간 0.022초

딜리버리 윈도우 로트-스트리밍 흐름 공정 문제 (Lot-Streaming Flow Shop Problem with Delivery Windows)

  • 윤석훈
    • 대한산업공학회지
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    • 제30권2호
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    • pp.159-164
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    • 2004
  • Lot-streaming is the process of splitting a job (lot) into a number of smaller sublots and then scheduling these sublots in order to accelerate the completion of jobs in a multi-stage production system. Anew genetic algorithm (NGA) is proposed for an-job, m-machine, equal-size sublot lot-streaming flow shop scheduling problem with delivery windows in which the objective is to minimize the mean weighted absolute deviation of job completion times from due dates. The performance of NGA is compared with that of an adjacent pairwise interchange (API) method and the results of computational experiments show that NGA works well for this type of problem.

Temperature distribution during heavy oil thermal recovery considering the effect of insulated tubing

  • Zhang, Songting
    • Geomechanics and Engineering
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    • 제19권6호
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    • pp.523-532
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    • 2019
  • Based on the formation characteristics, wellbore parameters and insulated tubing (IT) parameters of the Shengli oilfield, Shandong, China, a geomechanical model is built to predict the temperature distributions of the wellbore and formation. The effects of the IT heat conductivity coefficient (HCC), well depth and IT joint on the temperature distribution of the IT, completion casing, cement sheath, and formation are investigated. Results show the temperature of the formation around the wellbore has an exponentially decreasing relation with the distance to the wellbore. The temperature of the formation around the wellbore has an inverse relation with the IT HCC when the temperatures of the steam and the formation are given. The temperature of the casing outer wall is mainly determined by the steam temperature and IT HCC rather than by the initial formation temperature. The temperature of the casing at the IT joint is much larger than that of the other location. Due to the IT joint having a small size, the effects of the IT joint on the casing temperature distribution are limited to a small area only.

A Batch Arrival Queue with Bernoulli Vacation Schedule under Multiple Vacation Policy

  • Choudhury Gautam;Madan Kailash C.
    • Management Science and Financial Engineering
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    • 제12권2호
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    • pp.1-18
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    • 2006
  • We consider an $M^x/G/1$ queueing system with Bernoulli vacation schedule under multiple vacation policy. where after each vacation completion or service completion the server takes sequence of vacations until a batch of new customer arrive. This generalizes both $M^x/G/1$ queueing system with multiple vacation as well as M/G/1 Bernoulli vacation model. We carryout an extensive analysis for the queue size distributions at various epochs. Further attempts have been made to unify the results of related batch arrival vacation models.

동시공학 및 LOB를 사용한 반복 프로젝트 공기단축 방법론 (Crashing Method for Repetitive Project hybridizing concurrent engineering and LOB)

  • 민규태;이홍철;리현군;이동은
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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    • pp.41-42
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    • 2018
  • Various methods that crash the project completion time have been studied. Line-of-Balance (LOB) is well accepted as a useful method that enables steady resource utilization without frequent hire-and-fire of resources for a project having repetitive units. Existing studies involved in LOB-CPM focuses on thesis such as resource leveling and optimization in construction scheduling community. However, crashing methods are not arrived at a full maturity in LOB scheduling, because no one handles steady resource utilization while keeping activity-relationships. This paper proposes a method that crashes project completion time by hybridizing concurrent engineering and LOB scheduling without using additional resources.

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저항형 초전도 한류기에서의 퀀치 전파 (Quench propagation in resistive SFCL)

  • 김혜림;현옥배;최효상;황시돌;김상준
    • 한국전기전자재료학회논문지
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    • 제13권4호
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    • pp.337-342
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    • 2000
  • We fabricated resistive superconducting fault current limiters based on YB $a_{2}$/C $u_{3}$/ $O_{7}$ thin films and investigated their quench propagation characteristics. The YB $a_{2}$/C $u_{3}$/ $O_{7}$ films was coated with a gold layer and patterned into 1 mm wide meander lines by photolithography. The quench was concluded to start locally and propagates until completed. The quench propagation characteristics were explained based on the heat transfer within the film as well as between the film and the surrounding liquid nitrogen. The quench completion time depended strongly on potential fault current amplitude and not significantly on fault angle which indicates that the quench propagation speed is affected more by heat dissipation rate than by fault current increase rate. The quench completion time was 1 msec at the fault current of 65 $A_{peak/{\ak}}$.

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Effects of Self-Directed Learning Readiness on Academic Performance and Perceived Usefulness for Each Element of Flipped Learning

  • KIM, Minjeong;CHOI, Dongyeon
    • Educational Technology International
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    • 제19권1호
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    • pp.123-151
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    • 2018
  • This study aims to examine the effects of self-directed learning readiness (SDLR) on academic performance and the perceived usefulness for each elements of flipped learning. Based on their SDLR scores, 69 students were assigned to a high SDLR group and a low SDLR group. Academic performance was measured by the completion rate of a pre-class online learning and the final exam score, and perceived usefulness for each element of flipped learning was measured by a survey designed by the researcher. For academic performance, the high SDLR group showed a significantly higher completion rate than the low SDLR group, but no significant difference was observed in their final exam scores. Students in the high SDLR group perceived in-class student-centered activities as more useful than those in the low SDLR group. Additional qualitative analyses indicated that students needed more support from instructors and well-prepared peers. Finally, this study suggested that more examination on the various learning characteristics that may influence the effectiveness of flipped learning should be done.

정보시스템 아웃소싱 성공에 있어서 마음챙김 실천의 중요성에 대한 실증연구 (An Empirical Study on the Importance of Mindfulness Practice in the Success of Information Systems Outsourcing)

  • 이종만
    • 한국콘텐츠학회논문지
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    • 제13권12호
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    • pp.412-421
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    • 2013
  • 본 논문의 목적은 마음챙김의 올바른 이해를 바탕으로 그 실천의 중요성을 인식하고, 마음챙김 실천을 통해 정보시스템 아웃소싱 성공을 위한 하나의 방법을 찾아보는 것이다. 이를 위하여 본 연구는 계약 완결성, 관계강도, 마음챙김 실천, 신뢰수준, 정보시스템 아웃소싱 성공으로 구성된 이론모형을 제안하고 분석한다. 자료는 설문방법으로 수집하였고, PLS 방법으로 분석하였다. 실증분석 결과 첫째, 마음챙김 실천은 신뢰수준 뿐만 아니라 정보시스템 아웃소싱 성공에도 긍정적인 영향을 미치는 것으로 밝혀졌다. 둘째, 계약완결성과 관계강도는 모두 마음챙김 실천에 긍정적인 영향을 미치는 요인으로 나타났다. 본 연구의 결과는 정보시스템 아웃소싱 성공에 있어서 마음챙김 실천의 역할을 이해하기 위한 기초 자료를 제공하게 될 것이다.

Comparative Morphological Study on the Embryonic and Neonatal Development of the Filiform Papillae and Teeth in Mice

  • Jeong, Soon-Jeong
    • 치위생과학회지
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    • 제20권2호
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    • pp.74-81
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    • 2020
  • Background: In the early stages of development, teeth and lingual papillae are induced and developed through special and complex epithelial-mesenchymal interactions. Tooth completion indicates the beginning of the weaning phase, and accordingly, many oral tissues and organs are completed, and it is thought that their developmental completion times are related to each other. The purpose of this study was to clarify the embryonic and neonatal development of the filiform papillae and mandibular molar tooth, and discuss the developmental relationship between these organs by comparing the developmental completion times. Methods: Embryos at embryonic day 15 (EM15), 17 (EM17), and 21 (EM21) and mice at neonatal day 1 (NE1), 5 (NE5), 10 (NE10), and 21 (NE21) were used for experimentation. Tissues dissected from embryos and mice were fixed, and processed for histological analysis. Sections from the tissues were stained with hematoxylin and eosin for observation under a light microscope. Results: Based on the histological analysis results, the developmental process of the lingual epithelium covering the dorsal surface of the tongue was classified into three stages: initiation, morphogenesis, and functional. The development of the filiform papillae begins at EM17; undergoes rapid morphological changes in epithelial cells at EM21, PN1 and PN5, and reaches the functional stage at PN10, which is the sucking phase. Tooth development begins at EM13 or 15 and is completed at NE21 through prenatal and postnatal development. Conclusion: The development of the filiform papillae was initiated late and completed quickly through embryonic and neonatal development in comparison with the mandibular molar tooth. The filiform papillae are considered to play an important role in sucking rather than mastication as it is completed in the sucking phase.

방사선치료를 받는 암환자의 피로와 삶의 질 변화 (Changes in Fatigue and the Quality of Life of Cancer Patients Receiving Radiotherapy)

  • 이은숙;조루시아
    • 대한간호학회지
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    • 제27권3호
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    • pp.489-502
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    • 1997
  • Quality of life(QOL) and fatigue in cancer patients receiving the radiotherapy was assessed. The subjects were 46 cancer patients who daily attended the radiotherapy department. Assessment was done on four occassions : the first assessment was done on the treatment simulation visit, the second one was four weeks after treatment started, the third one at the completion of treatment and the last assessment was done between six and eight week following treatment. The results are as follows : The fatigue scores of the patients at each stage of assessment ranged from 5.49 points to 7.67 points and highest score was recorded at the third assessment that is, at the completion of treatment. The fatigue points showed an increase from the 1st. to 3rd. stage. However, at the 4th. stage, fatigue points decreased to the level at the first stage of assessment. QOL were assessed in three areas namely, physical, emotional and social /functional. The QOL scores in the physical area showed the highest score, followed by social /functional and emotional areas. The QOL scores decreased gradually to the third. stage of assessment thereafter recovered to the level of the first. stage. Correlation between QOL and fatigue scores during the treatment indicated that the level of QOL decreased as the level of fatigue increased. In particular, fatigue persisted after completion of the treatment and showed a significantly negative correlation with QOL. The present study strongly suggests that a strategy to restore the emotional well being level of the patient should be devised in order to improve QOL and reduce fatigue of patients receiving radiotherapy.

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SI 프로젝트 관리자의 리더십 역량과 프로젝트 참여자 개인역량이 프로젝트 성과에 미치는 영향에 관한 연구 (A Study on the Influence of SI Project Manager's Leadership Competencies and Project Participants' Individual Competencies on Project Performance)

  • 이중우;이철규
    • 한국IT서비스학회지
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    • 제21권4호
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    • pp.27-61
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    • 2022
  • In order to improve project performance by analyzing the effects of the project manager's leadership competency and the individual competency of the project participants on the project performance, this study examines the effect. In this study, a research model and hypothesis were established to understand the causal relationship between leadership competency, individual competency, and project performance, and a survey was conducted based on this. Overall, it was found that the leadership competency of the project manager and the individual competency of the project participants had a positive effect on the project management performance, the project leadership competency had a positive effect on the completion performance, and the project participant individual competency had a negative effect on the completion performance. As a result of analyzing the effect of the project manager's core competency on the project management performance according to the amount or period of the project type, which is the moderating variable, it was found that there was no moderating effect on the management performance. For the success of the SI project, it is most important to understand the project characteristics well and select a PM suitable for the characteristics, and methods for nurturing excellent project managers should be further studied. In addition, it is expected that it will be possible to identify the effect of project manager leadership competency and participant competency on project performance based on sophisticated research design for more competent PM selection.