• 제목/요약/키워드: Technical change

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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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외자계와 내자계 자동차 부품회사의 경쟁력 비교 (Competitiveness Analysis of National and Foreign Auto-parts Makers)

  • 유지수;정경희
    • 대한산업공학회지
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    • 제36권3호
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    • pp.186-192
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    • 2010
  • The present study classified the auto-parts makers into four groups according to their investment ownership. Four groups consist the one fully owned by Koreans, the one fully owned by foreigners, the one owned less than 100% but more than 50% by foreigners, lastly the one owned by less than or equal to 50% by foreigners. Among these, the auto-parts makers, 100% foreign ownership, have the highest Malmquist productivity index while 100% Korean-owned part-makers has the lowest productivity. In case of the 100% foreign ownership companies, the cause of Malmquist change, however, is attributed to the technical efficiency change. In particular, the pure technical change is the main source of the Malmquist change. This may indicate that the 100% foreign-owned companies have successfully transferred their production process technologies to the Korean plants. They are enjoying so called the "imitation-effect." 100% Korean-owned companies were not able to create the "imitationeffect" and therefore failed to close the gap with the foreign-owned companies in terms of the production efficiency. 100% Korean-owned auto-parts makers, however, outperformed the foreign-owned companies in the technological change. The outstanding technological change may indicate that Korean-owned part makers were able to narrow the gap with the foreign-owned companies in the area of engineering technological capabilities. The same results were also observed for 50% foreign-owned companies. Knowing that the core competence of the auto-parts makers lies on the engineering technological capabilities, the research found that the most desirable form of the foreign investment was 50% of foreign ownership.

CelIulase 구성 요소별 처리에 의한 펄프 섬유의 특성 변화 (Change of Chemical Pulp Fiber Properties with Cellulase Component($C_1$, $C_{x}$) Treatment)

  • 김병현;전양
    • 펄프종이기술
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    • 제30권2호
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    • pp.13-23
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    • 1998
  • Two major cellulase components purified with sephadex G-75 and DEAE sepharose were applied to bleached kraft pulp to inverstigate the change of fiber properties. Cellulose viscosity was very sensitive to $C_x$ component treatment (more than 15% drop was observed) while being little influenced by $C_1$, component (only 2% drop). Fiber fraction longer than 2mm was reduced by $C_x$ treatment while short fiber fraction was increased greatly by more than 15%. There was little change in fiber length distribution by combined treatment of $C_1$ 1 and $C_x$ at equal. In this case, fine contents increased by more than 2.5% at equivalent refining time. WRV and Density were increased as the amount of $C_1$ or $C_x$ treatment was increased. $C_{x}$ was main cause for increasing them. But the effect fell as enzyme dosage.

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Lessons Learned from Institutionalization of ML (Machine Learning) Supported HR Services in the Existence of Multiple Institutional Logics

  • Gyeung-min Kim;Heesun Kim
    • Asia pacific journal of information systems
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    • 제33권4호
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    • pp.1171-1187
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    • 2023
  • This study explores how an organization has successfully implemented ML-supported HR services to resolve high employee turnover problems in the IT sector. The empirical setting of the research is where contradicting institutional logics exist among technical, HR, and business groups regarding the ML model development and use of the model predictions in HR services. Institutional framework is used to identify the roles of organizational actors and the legitimacy structures in the organizational environments that can shape or constrain the ML led organizational changes. In institutional theories, technology adoption and organizational change are not only constrained by organizational context, but also fostered through organizational actors' roles and efforts to increase the legitimacy for the change. This research found that when multiple contradicting institutional logics exist, legitimizing the establishment of an enabling environment for multiple logics to reconcile and for the project to move forward is critical. Industry-wide conditions, previous experiences with the pilot ML project, forming a TFT with clearly defined roles and responsibilities, and relevant KPIs are found to legitimize the HR team and the business division to collaborate with the technical personnel to launch ML-supported HR services.

고효율 변압기용 레이저자구 전기강판 개발 (Development of Electrical Steel by Laser Magnetic Domain Refinement for Applying to Transformers of High Energy Efficiency)

  • 권오열;차상윤;김지현;하경호;김재관
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 제39회 하계학술대회
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    • pp.625-626
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    • 2008
  • The magnetic domain-refining techniques such as ball scratching, laser irradiation and plasma have been developed to reduce the domain wall spacing and thus iron losses in Fe-3%Si grain-oriented silicon steels. In view point of magnetic properties, it was supposed that the locally residual stresses change the magnetoelastic energy of the material and thus the spacing between $180^{\circ}$ domain walls decreases in order to reduce the magnetostatic energy. The effect of laser irradiation on iron loss and magnetostriction reduction for Fe-3%Si grain-oriented steel were investigated. Since the local tensile stresses were induced at the surface of Fe-3%Si steel by the laser irradiation, the minimum iron loss caused by reducing eddy current loss was obtained in spiete of the decrease of permeability by hindering eddy current loss was obtained in spite of the decrease of permeability by hindering the domain wall movement around the induced stress field. Furthermore, the laser treated 3%Si steel has lower magnetostriction as compared to non laser-treated steel and is less sensitive to applying pre-stresses due to the volume reduction of $90^{\circ}$ domain in materials.

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Experimental and numerical analyses on determination of indirect (splitting) tensile strength of cemented paste backfill materials under different loading apparatus

  • Komurlu, Eren;Kesimal, Ayhan;Demir, Serhat
    • Geomechanics and Engineering
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    • 제10권6호
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    • pp.775-791
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    • 2016
  • The indirect tensile strengths (ITSs) of different cemented paste backfill mixes with different curing times were determined by considering crack initiation and fracture toughness concepts under different loading conditions of steel loading arcs with various contact angles, flat platens and the standard Brazilian test jaw. Because contact area of the ITS test discs developes rapidly and varies in accordance with the deformability, ITSs of curing materials were not found convenient to determine under the loading apparatus with indefinite contact angle. ITS values increasing with an increase in contact angle can be measured to be excessively high because of the high contact angles resulted from the deformable characteristics of the soft paste backfill materials. As a result of the change of deformation characteristics with the change of curing time, discs have different contact conditions causing an important disadvantage to reflect the strength change due to the curing reactions. In addition to the experimental study, finite element analyses were performed on several types of disc models under various loading conditions. As a result, a comparison between all loading conditions was made to determine the best ITSs of the cemented paste backfill materials. Both experimental and numerical analyses concluded that loading arcs with definite contact angles gives better results than those obtained with the other loading apparatus without a definite contact angle. Loading arcs with the contact angle of $15^{\circ}$ was found the most convenient loading apparatus for the typical cemented paste backfill materials, although it should be used carefully considering the failure cracks for a valid test.

기술 변화의 영향을 고려한 비즈니스모델 혁신 분석 틀 (Analytical Framework for the Impact of Technical Change on Business Model Innovation)

  • 임홍탁;한정원
    • 한국정보통신학회논문지
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    • 제23권2호
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    • pp.139-148
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    • 2019
  • 디지털 기술에 의한 다양한 비즈니스 모델 혁신은 기업 수준의 변화를 넘어서 시스템 혁신을 이르는 중요한 현상으로 주목받고 있으나 기술의 역할에 대한 이론적 연구는 드물다, 본 연구는 비즈니스의 기본 임무를 바탕으로 구분한 핵심기술 개념, 그리고 디지털 기술에 의한 가치 창출에 대한 이론과 사례 검토를 토대로 비즈니스 모델혁신에 끼치는 기술변화의 영향을 살펴보았다. 기술, 특히 디지털 기술은 효과성과 효율성의 향상이라는 새로운 가치 창출을 동력으로 문제해결형 모델, 생산형 모델, 네트워크형 모델들의 전환, 확장, 분리 및 플랫폼화를 통해 비즈니스 모델혁신에 영향을 준다.

라인파이프 강재의 수소유기균열에 미치는 열간압연 공정변수의 영향 (Effect of Non-Metallic Inclusions and Hot Rolling Process Parameters on Hydrogen Induced Cracking of Linepipe Steels)

  • 고성웅;정환교;강기봉
    • 대한금속재료학회지
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    • 제46권4호
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    • pp.257-266
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    • 2008
  • AHydrogen induced cracking (HIC) was phenomenologically studied in terms of the effect of nonmetallic inclusions and hot rolling process parameters. By comparing the level of non-metallic inclusions in two different kinds of commercial grade steels having different HIC resistance, the role of non-metallic inclusions in HIC occurrence was investigated. Change in inclusion morphology and distribution during hot rolling was also studied throughout slab, rolling at austenite recrystallization region (roughing mill; RM) and rolling at austenite non-recrystallization region (finish mill; FM). In addition, the contribution of RM and FM parameters to HIC was investigated from the standpoint of change in inclusion morphology during hot rolling processes. As a result, HIC was closely related to the separation of large complex inclusion during hot rolling process. Large complex inclusions originated from the improper Ca treatment, after which equilibrium composition of slag should have resulted in eutectoid composition. By controlling the equilibrium slag composition equivalent to eutectoid one, HIC resistance could be improved due to the reduced size of inclusions. In addition, change in reduction/pass in RM had an effect on HIC resistance of steels while that in FM did not. Increase in the reduction/pass in the latter stage of RM improved HIC resistance of steels by enhancing the void enclosure around inclusions.

원자력시설 해체 규제요건과 기술기준 연계를 통한 요구관리 (Requirement Management through Connection between Regulatory Requirements and Technical Criteria for Dismantling of Nuclear Installations)

  • 박희성;박종선;홍윤정;김정국;홍대석
    • 시스템엔지니어링학술지
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    • 제14권1호
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    • pp.63-71
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    • 2018
  • This paper discusses decommissioning procedure requirements management using requirement engineering to systematically manage the technical requirements and criteria that are required in decontamination and decommissioning activities, and the regulatory requirements that should be complied with in a decommissioning strategy for research reactors and nuclear power plants. A schema was designed to establish the traceability and change management related to the linkage between the regulatory requirements and technical criteria after classifying the procedures into four groups during the full life-cycle of the decommissioning. The results confirmed that the designed schema was successfully traced in accordance with the regulatory requirements and technical criteria required by various fields in terms of decontamination and decommissioning activities. In addition, the changes before and after the revision of the Nuclear Safety Act were also determined. The dismantling procedure requirement management system secured through this study is expected to be a useful tool in the integrated management of radioactive waste, as well as in the dismantling of research reactor and nuclear facilities.