• 제목/요약/키워드: Power quality improvement

검색결과 577건 처리시간 0.024초

A Quantitative Approach to Minimize Energy Consumption in Cloud Data Centres using VM Consolidation Algorithm

  • M. Hema;S. KanagaSubaRaja
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제17권2호
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    • pp.312-334
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    • 2023
  • In large-scale computing, cloud computing plays an important role by sharing globally-distributed resources. The evolution of cloud has taken place in the development of data centers and numerous servers across the globe. But the cloud information centers incur huge operational costs, consume high electricity and emit tons of dioxides. It is possible for the cloud suppliers to leverage their resources and decrease the consumption of energy through various methods such as dynamic consolidation of Virtual Machines (VMs), by keeping idle nodes in sleep mode and mistreatment of live migration. But the performance may get affected in case of harsh consolidation of VMs. So, it is a desired trait to have associate degree energy-performance exchange without compromising the quality of service while at the same time reducing the power consumption. This research article details a number of novel algorithms that dynamically consolidate the VMs in cloud information centers. The primary objective of the study is to leverage the computing resources to its best and reduce the energy consumption way behind the Service Level Agreement (SLA)drawbacks relevant to CPU load, RAM capacity and information measure. The proposed VM consolidation Algorithm (PVMCA) is contained of four algorithms: over loaded host detection algorithm, VM selection algorithm, VM placement algorithm, and under loading host detection algorithm. PVMCA is dynamic because it uses dynamic thresholds instead of static thresholds values, which makes it suggestion for real, unpredictable workloads common in cloud data centers. Also, the Algorithms are adaptive because it inevitably adjusts its behavior based on the studies of historical data of host resource utilization for any application with diverse workload patterns. Finally, the proposed algorithm is online because the algorithms are achieved run time and make an action in response to each request. The proposed algorithms' efficiency was validated through different simulations of extensive nature. The output analysis depicts the projected algorithms scaled back the energy consumption up to some considerable level besides ensuring proper SLA. On the basis of the project algorithms, the energy consumption got reduced by 22% while there was an improvement observed in SLA up to 80% compared to other benchmark algorithms.

영상장치 센서 데이터 QC에 관한 연구 (A study on imaging device sensor data QC)

  • 윤동민;이재영;박성식;전용한
    • Design & Manufacturing
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    • 제16권4호
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    • pp.52-59
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    • 2022
  • Currently, Korea is an aging society and is expected to become a super-aged society in about four years. X-ray devices are widely used for early diagnosis in hospitals, and many X-ray technologies are being developed. The development of X-ray device technology is important, but it is also important to increase the reliability of the device through accurate data management. Sensor nodes such as temperature, voltage, and current of the diagnosis device may malfunction or transmit inaccurate data due to various causes such as failure or power outage. Therefore, in this study, the temperature, tube voltage, and tube current data related to each sensor and detection circuit of the diagnostic X-ray imaging device were measured and analyzed. Based on QC data, device failure prediction and diagnosis algorithms were designed and performed. The fault diagnosis algorithm can configure a simulator capable of setting user parameter values, displaying sensor output graphs, and displaying signs of sensor abnormalities, and can check the detection results when each sensor is operating normally and when the sensor is abnormal. It is judged that efficient device management and diagnosis is possible because it monitors abnormal data values (temperature, voltage, current) in real time and automatically diagnoses failures by feeding back the abnormal values detected at each stage. Although this algorithm cannot predict all failures related to temperature, voltage, and current of diagnostic X-ray imaging devices, it can detect temperature rise, bouncing values, device physical limits, input/output values, and radiation-related anomalies. exposure. If a value exceeding the maximum variation value of each data occurs, it is judged that it will be possible to check and respond in preparation for device failure. If a device's sensor fails, unexpected accidents may occur, increasing costs and risks, and regular maintenance cannot cope with all errors or failures. Therefore, since real-time maintenance through continuous data monitoring is possible, reliability improvement, maintenance cost reduction, and efficient management of equipment are expected to be possible.

직무요구-자원모델에 기반한 병원간호사의 잡크래프팅이 조직유효성에 미치는 효과 (Effects of Clinical Nurses' Job Crafting on Organizational Effectiveness Based on Job Demands-Resource Model)

  • 이은영;김은경
    • 대한간호학회지
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    • 제53권1호
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    • pp.129-143
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    • 2023
  • Purpose: This study aimed to examine the mediating effects of clinical nurses' job crafting on organizational effectiveness based on the job demands-resources model proposed by Bakker and Demerouti (2017). Methods: The participants consisted of 393 nurses working in nursing units of a tertiary general hospital located in Cheongju region. The data, collected using questionnaire from August 9 to August 20, 2021, were analyzed using SPSS 23.0 and AMOS 27.0. Results: The goodness-of-fit (GoF) test results on the modified model (χ2 = 2.7, GFI = .94, SRMR = .03, RMSEA = .06, NFI = .92, CFI = .94, TLI = .92, AGFI = .90), indicated that the GoF index satisfied the recommended level. Regarding the effects of each variable on organizational effectiveness, job crafting showed statistically significant direct (β = .48, p < .001), indirect (β = .23, p < .001), and total effects (β = .71, p < .001). Burnout showed statistically significant direct effect (β = - .17, p < .001). Work engagement showed statistically significant direct (β = .41, p < .001) and total effects (β = .41, p < .001). The factors explaining organizational effectiveness were job crafting, burnout, and work engagement, which had an explanatory power of 76.7%. Conclusion: Nurses' job crafting is an important mediating factor for enhancing the organizational effectiveness of nursing organizations. Hospitals should develop job-crafting success cases and related education and training programs as a strategy for enhancing the job crafting of nurses and, consequently organizational effectiveness.

하브루타를 적용한 신병훈련의 효과가 훈련병의 만족도 및 성취도에 미치는 영향 (The Effects of Recruit Training with Havruta on the Satisfaction and Achievement of Trainees)

  • 김수연;이동형
    • 산업경영시스템학회지
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    • 제45권4호
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    • pp.210-216
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    • 2022
  • The army is concerned about the decrease in enlistment resources due to the low birth rate and the weakening of military combat power due to the shortening of the military service period. Now, the military's quantitative growth is no longer limited and it is a time for qualitative growth. To this end, the Army has been applying the Israeli learning method Havruta to recruit training to improve the quality of training since 2019. After applying Havruta, several scholars have studied the effect of recruit training applying Havruta. As a result, it was verified that recruit training applying Havruta improves the inner motive, creativity, and military service value of trainees. This study investigated how trainees' inner motive, creativity, and military service value affect their satisfaction and achievement. In addition, it was studied whether the effect of recruit training applied with Havruta on achievement differs according to the educational background (high school graduate or higher) and military family (professional soldiers within 4th degree) of the trainees. To this end, a survey was conducted on 472 recruits, and the structural relationship between each variable and the moderating effect were analyzed using the structural equation model. As a result of the study, military service value did not affect training satisfaction. Also, there was a difference in the effect of creativity on training satisfaction according to the educational background of new recruits, and there was a difference in the effect of military service value on training satisfaction and training achievement according to military family members. The purpose of this study is to contribute to the improvement of the army's recruit training development plan and effective training system.

THE INFLUENCE OF THE PROJECT MANAGER ON THE SUCCESS OF THE CONSTRUCTION PROJECTS

  • Mahdi M Abdulsamad Ali;Nicholas Chileshe
    • 국제학술발표논문집
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    • The 3th International Conference on Construction Engineering and Project Management
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    • pp.345-353
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    • 2009
  • The success and failure of any project depends upon many factors, the Project Manager is considered to be the key contributor to the success of any project, as well as a guide to the team members to achieve the client satisfaction (Cost, Time and Quality). Therefore the main aim of this paper is to provide a practical approach for understanding the importance of the Project Manager and his effectiveness to the success of the construction projects. In addition, the Project Manager's roles, responsibilities and duties have direct impact to the success of the construction projects. In order to identify the thoughts and opinion of the construction industry on this particular assertion, a quantitative study was carried out within the UK construction industry. The result of the study shows that there is an extremely strong correlation between the Project Manager and the success of the construction projects. In construction projects the Project Manager is considered to be one of the most important people who can lead and drive the projects in the right direction and conclude construction projects successfully. Moreover, these can play the most important role regarding the improvement of the organization's performance, the organization's profitability and the client's satisfaction. The research confirmed that the Project Manager is a very essential element to the success of the construction project and have an impact at every stage of the construction project. So it concluded that selection of a Project Manager should be carefully done with regard to experience, knowledge, power/authority and good understanding to the kind of the project.

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Sustainability Appraisal of Chinese Railway Projects In Nigeria: Afoot

  • Awodele, Imoleayo Abraham;Mewomo, Modupe Cecilia
    • 국제학술발표논문집
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    • The 9th International Conference on Construction Engineering and Project Management
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    • pp.967-974
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    • 2022
  • It is no news that Nigeria's infrastructure challenge is enormous. In the global ranking, Nigeria ranked low in quantity and quality of its infrastructural provision which has a great impact on the ease of business transaction. Low investments in transportation have brought about the current infrastructural deficit. Recently, the Nigerian government has made effort to address at least to some extent the infrastructural deficit through Public-Private Partnership, but this has not yielded the desired result. Moreover, the sustainability issues relating to railway projects such as, emissions, noise pollution, ecosystem, and other environmental issues calls for urgent attention. Hence, this necessitated consideration on sustainability appraisal for the Chinese rail project in Nigeria. This study reviews sustainability of railway projects built by the Chinese firm in Nigeria with particular emphasis on the environmental and social impact of these projects. The study further identified issues and challenges in project implementation with a particular focus on civil dialogue and community engagements. A detailed literature search was conducted on railway projects and infrastructure by systematically reviewing selected published articles.The analysis of the selected articles identified sustainability issues and potential for improvement of Chinese railway projects and how they contribute to or inhibit competitiveness in the Nigerian railway market. From the literature searched, some of the projects constructed by Chinese firm revealed that there is economic and social impact of railway projects delivered by the Chinese firm in terms of capacity development and knowledge transfer potentiality. For instance, in the just concluded Lagos-Ibadan railway projects, the study gathered that the project brought about 5000 jobs and local staff were trained by the Chinese company, this will boost man power and local content capability. Also, it will significantly improve Nigeria's infrastructure and boost its economic development. The study suggests that Nigerian government should ensure and provide an enabling environment that is conducive for investment on the continent. Peace, improved security, and decent governance are the best conditions for sustainable transportation growth.

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신경망 회로 제어기를 이용한 선박 엔진 발전기의 여자기 제어 성능 개선에 관한 연구 (Study on the Performance Improvement of Marine Engine Generator Exciter Control using Neural Network Controller)

  • 김희문;김종수;김성완;전현민
    • 해양환경안전학회지
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    • 제29권6호
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    • pp.659-665
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    • 2023
  • 선박 발전기의 여자기는 출력 단자 전압을 일정하게 유지하기 위하여 여자전류 제어를 통해 자속을 조정한다. 여자기 내부에 있는 전압제어기는 통상적으로 비례 적분 제어방식이 사용되는데 게인과 시정수에 의해 결정되는 응답 특성은 적절치 못한 설정값에 의해 원하지 않는 출력을 내며 이로 인해 선내 전력의 품질과 안정성을 떨어뜨릴 수 있다. 본 논문에서는 IEEE에서 제공하는 AC4A 타입의 여자기 모델을 통해 얻을 수 있는 안정적인 입출력 데이터를 활용하여 신경망 회로를 학습시킨 후 기존의 비례 적분 제어방식의 전압제어기를 학습된 신경망 회로 제어기로 대체하여 시뮬레이션을 수행하였다. 그 결과 기존 대비 최대 9.63%까지 오버슈팅이 개선되었으며, 안정적인 응답 특성에 대한 우수성을 확인하였다.

음질 열화를 줄이고 공격에 강인한 오디오 워터마킹 알고리듬 (Robust Audio Watermarking Algorithm with Less Deteriorated Sound)

  • 강명수;조상진;정의필
    • 한국음향학회지
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    • 제28권7호
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    • pp.653-660
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    • 2009
  • 본 논문에서는 오디오 신호의 저작권 보호와 효과적인 음질 개선을 위한 새로운 워터마킹 알고리듬을 제안한다. 제안한 방법은 원 신호에 푸리에 변환을 하여 주파수 영역으로 변환하고 n개의 서브밴드로 균등 분할한다. 각 밴드별 에너지를 계산하여 에너지가 큰 것부터 k개를 선택하고 해당 밴드에서 p개의 주요 피크 성분을 검출하여 길이 m의 워터마크를 삽입한다. 워터마크된 오디오 신호를 청자에게 들려주었을 때 워터마크 삽입으로 인한 오디오 신호의 왜곡을 느끼지 못하였다. 또한, 제안한 방법은 Cox 방법만큼 MP3 압축, 잘라내기 (cropping),주파수 변환 (FFT), 반향 (echo)과 같은 워터마크 공격에 강인하였고 신호 대 잡음비 측면에서는 10 dB이상 우수함을 실험을 통해 확인할 수 있었다.

CMOS 기반 X선 영상의 해상력 향상을 위한 Gd2O2S:Tb 미세형광체 필름 제작 및 영상 질 평가 (Fabrication of Gd2O2S:Tb fine scintillator film and evaluation of image quality for resolution improvement of X-ray imaging based on CMOS)

  • 강상식;최영준;정봉재;노시철;조창훈;윤인찬;박지군
    • 한국방사선학회논문지
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    • 제5권5호
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    • pp.283-287
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    • 2011
  • 본 연구는 고해상도 디지털 X선 영상 검출기 적용을 위해 미세 $Gd_2O_2S$:Tb 형광체 분말을 저온 액상법을 이용하여 합성하였다. 제조된 형광체 분말을 이용하여 입자침전법을 이용하여 형광체 필름을 제작하여 발광특성을 조사하였다. 측정결과, Tb 첨가농도에 따른 상대적인 발광량 측정결과 5 wt%의 첨가농도에서 가장 높은 발광효율을 보였으며, 첨가농도가 증가할수록 소광현상에 의한 발광강도가 급격히 감소하는 경향을 보였다. 또한 270 ${\mu}m$ 두께의 $Gd_2O_2S$:Tb에서 2945 pC/$cm^2$/mR의 발광 강도를 가졌으며, 발광 강도가 거의 포화되는 것을 관찰할 수 있었다. 끝으로 제조된 형광체의 영상획득 성능을 평가하기 위해 상용화된 CMOS 센서를 이용하여 X선 영상을 획득하여 MTF, NPS를 측정하여 DQE 평가를 수행하였다. 측정결과, DQE(0)의 값은 37%로 다소 낮은 값을 보였다. 향후 필름 제조 공정상의 문제점을 해결한다면, DQE를 개선할 수 있을 것으며, 고해상도 의료 방사선 영상 시스템 적용에 유용하게 적용 가능할 것으로 판단된다.

한방복합치료를 병행한 도인운동요법이 요통환자의 통증 및 기능 개선에 미치는 영향 : 후향적 관찰 연구 (Effect of The Daoyin Exercise Therapy Combined with Complex Korean Medicine Treatment on Pain and Function Improvement of Low Back Pain Patients : A Retrospective Observational Study)

  • 최봉석;이은정;이옥진;이정민;김은석;송광찬;정인철;오민석
    • 동의생리병리학회지
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    • 제32권1호
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    • pp.88-97
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    • 2018
  • This study was designed to prove the effect of the Daoyin exercise therapy combined with complex korean medicine treatment on pain and function improvement of low back pain patients. A retrospective observational study. 30 low back pain patients, checked numeric rating scale(NRS) over 5, were treated with the Daoyin exercise therapy combined with complex korean medicine treatment. NRS, roland & morris disability questionnaire(RMDQ), range of motion(ROM), isokinetic muscle strength, and euroqol five demension questionnaire(EQ-5D) were checked to evaluate patients. The Daoyin exercise therapy combined with complex korean medicine treatment reduced NRS $5.67{\pm}1.40$ to $3.73{\pm}1.72$, improved RMDQ $10.33{\pm}4.91$ to $8.17{\pm}5.40$, strengthened lumbar muscle's peak torque and improved EQ-5D $0.56{\pm}0.20$ to $0.63{\pm}0.15$ and euroqol visual analogue scale(EQVAS) $46.80{\pm}19.95$ to $57.50{\pm}19.93$ but had no effect on ROM. NRS decreased significantly as the number of trials increased. No one had serious adverse reactions. As described above, the Daoyin exercise therapy combined with complex korean medicine treatment can help reducing low back pain, improving lumbar function, strengthening lumbar muscle power and stamina and improving quality of life of low back pain patients.