• 제목/요약/키워드: Critical factor

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통제 아키텍처를 이용한 정보자원 관리 (Information Resource Management Using by Integrated Control Architecture)

  • 김정욱
    • 품질경영학회지
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    • 제38권1호
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    • pp.64-74
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    • 2010
  • Since management of information resources is getting more complicated in the distributed, heterogeneous computing environment, the capability of monitoring and controlling the dispersed information resources is perceived as a critical success factor for the effective enterprise-wide information resource management. Integrated Control Architecture(ICA) provides that capability. Utilizing such architecture, we can manage corporate information resources more efficiently, perform impact analysis for changes in information resources, and alleviate the human effort by automating the monitoring of critical information resources. In this paper, we propose a conceptual framework and metamodel of ICA.

Guided bone regeneration

  • Kim, Young-Kyun;Ku, Jeong-Kui
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제46권5호
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    • pp.361-366
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    • 2020
  • Guided bone regeneration (GBR) is a surgical procedure that utilizes bone grafts with barrier membranes to reconstruct small defects around dental implants. This procedure is commonly deployed on dehiscence or fenestration defects ≥2 mm, and mixing with autogenous bone is recommended on larger defects. Tension-free primary closure is a critical factor to prevent wound dehiscence, which is critical cause of GBR failure. A barrier membrane should be rigidly fixed without mobility. If the barrier is exposed, closed monitoring should be utilized to prevent secondary infection.

피로누적에 따른 최적 비행시간 산출에 관한 연구 (A Study on the Optimal Flight Time According to the Amount of Fatigue)

  • 이승훈;윤봉수
    • 한국국방경영분석학회지
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    • 제24권1호
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    • pp.41-57
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    • 1998
  • Since the aircraft has a property of moving in the three-dimensional space, it may cause personally and financially critical damage in the case of an accident. Among the causes of aircraft accident, human factor has occupied about 70% of all accidents. Specially, fatigue among human's problems has been studied earlier than any other factor. Fatigue has been the cause of 75% of accidents that are related to human factor. So many studies have been conducted. But the direction of these studies mainly attach importance to the sleep loss and circadian rhythm. Limitation for flight time of ICAO is 8 hours per day, civil airlines in domestic line also adopt the limitation. But this rule is not based on human's performance but compromise between labor and management. The long-haul flight brings about a mental block to pilot. This mental block decreases performance of pilot and loses a lot of important information. So this may cause many accidents. This paper is to offer optimal flight time according to the amount of fatigue due to increasing flight time. The optimal flight time is searched through the field experiment. The experiment has adopted two methods. One is to examine pilot's objective fatigue accumulation rate through the critical fusion frequency, and another is to investigate pilot's subjective fatigue feeling through the fatigue subjective symptoms investigation table.

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철골 및 섬유보강 폴리머(FRP) 복합 기둥의 설계강도식에 관한 비교 연구 (A Comparison of Design Strength Equations between Steel and Fiber Reinforced Polymer Composites Columns)

  • 최열;편해완
    • 한국공간구조학회논문집
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    • 제3권3호
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    • pp.85-93
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    • 2003
  • Steel, concrete and their combination materials are the most 6commonly used materials for civil engineering structural systems such as buildings, bridge structures and other structures. Recently, however, fiber reinforced polymer (FRP) composites, a relatively new composite material made of fibers and polymer resins, have been gradually used in structural systems as an alternative structural material. This paper describes a comparison of design strength equations for steel column and FRP composite column based on design philosophies. The safety factors used in allowable stress design (ASD) are relatively higher in FRP structural design than steel structural design. Column critical stress equations of FRP composites column from an experimental study can be represented by Euler elastic buckling equation at the long-range of slenderness, and an exponential form at the short-range of slenderness as defined in Load and Resistance Factor Design (LRFD) of steel column. The column strength of steel and FRP composite columns in large slenderness is independent of material strength, this result verified the elastic buckling equation as derived by Eq. (15) and Eq. (5).

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자동차구조용 $SiC_p/Al-Si$복합재의 피로균열 진전특성에 대한 연구 (Fatigue Crack Growth Characteristics of $SiC_p/Al-Si$ Alloy Composites for Automotive Structures)

  • 고승기;이해무
    • 한국자동차공학회논문집
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    • 제13권4호
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    • pp.174-181
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    • 2005
  • In order to investigate the behavior of fatigue crack growth of SiC-particulate- reinforced Al-Si alloy composites, fatigue tests using single edge notched tension(SENT) specimens were performed. Composite materials were manufactured by using both permanent die casting and extrusion processes with different volume fractions of $10\%\;and\;20\%$. $SiC_p-reinfurced$ Al-Si composites showed the increased levels of threshold stress intensity factor range, ${\Delta}K_{th}$, for the increased volume fractions of SiC particles, which implies the increased fatigue crack growth resistance at the threshold or low ${\Delta}K$ levels, compared to the unreinforced Al-Si alloy. In the Paris region, however, the composites showed the increased rate of crack growth resulting in the unfavorable effects on the fatigue crack growth resistance. Critical stress intensity factor range at unstable crack growth leading to final fracture decreased as the volume fraction of SiC particle increased, because of the reduced fracture toughness of the composites. Extruded materials showed higher threshold and critical values than the cast materials.

심부전 환자의 빈혈과 사망률 및 재입원 간의 관계에 대한 통합적 고찰 (Anemia as a Risk Factor of Mortality and Rehospitalization in Patients with Heart Failure : An Integrative Review)

  • 손연정;김보환
    • 중환자간호학회지
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    • 제12권1호
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    • pp.94-108
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    • 2019
  • Purpose : Heart failure (HF) is considered an important medical burden with rehospitalization and mortality. Anemia is a major risk factor associated with the severity of HF. To improve the understanding of the impact of anemia in the population with HF, we explored the prevalence of anemia, its guidelines, relationship between anemia and mortality or rehospitalization, and limitation of reviewed papers of various populations with HF. Method: We used Whittemore and Knafl's integrative review methodology (2005), and thirty research papers were analyzed. PubMed, CINAHL, Cochrane, PsychInfo, Embase, Web of Science were searched for papers published between January 1960-June 2018. Results: Anemia in individuals with HF was primarily defined using the World Health Organization guideline. The prevalence of anemia in patients with HF varied from 9% to 56.7%. Moreover, such a condition significantly increases the prevalence of mortality or rehospitalization in patients with HF. The analyzed majority were non-prospective cohort study including secondary data analysis. Conclusion: Anemia in individuals with HF is a significant risk factor of mortality and rehospitalization. Prospective cohort studies should be designed to identify the optimal value for screening anemia and the impact of anemia on rehospitalization and mortality among HF patients.