• 제목/요약/키워드: Total system performance assessment

검색결과 136건 처리시간 0.025초

축류형 유체기계에서 익단 누설 유동 해석을 위한 난류 모델 성능 평가 (Performance Assessment of Turbulence Models for the Prediction of Tip Leakage Flow in an Axial-Flow Turbomachinery)

  • 이공희;백제현
    • 대한기계학회논문집B
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    • 제27권12호
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    • pp.1655-1666
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    • 2003
  • It is experimentally well-known that high anisotropies of the turbulent flow field are dominant inside the tip leakage vortex, which is attributable to a substantial proportion of the total loss and constitutes one of the dominant mechanisms of the noise generation. This anisotropic nature of turbulence invalidates the use of the conventional isotropic eddy viscosity turbulence models based on the Boussinesq assumption. In this study, to check whether an anisotropic turbulence model is superior to the isotropic ones or not, the results obtained from the steady-state Reynolds averaged Navier-Stokes simulations based on the RNG k-$\varepsilon$ model and the Reynolds stress model (RSM) are compared with experimental data for two test cases: a linear compressor cascade and a forward-swept axial-flow fan. Through this comparative study of turbulence models, it is clearly shown that the RSM, which can express the production term and body-force term induced by system rotation without introducing any modeling, should be used to predict quantitatively the complex tip leakage flow, especially in the rotating environment.

제세동 가능 심정지 환자의 병원전 응급처치 수행에 대한 분석 (Analysis to Performance of Prehospital emergency care for cardiac arrest patient showing shockable rhythm on EKG)

  • 고봉연;이정은
    • 한국응급구조학회지
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    • 제15권1호
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    • pp.79-88
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    • 2011
  • Purpose : Prehospital emergency care for shockable rhythm is one of major concerns of emergency medical services. But, in Korea, prehospital medical service systems are not yet well established. We tried to offer one of the fundamental data to develop of these system. Method : After application of exclusion criteria, 200 patients who had shockable rhythm from January to December, 2008 were included in this study. Restrospective review of Prehospital care Reports of these patients was done. Result : Total 200 cases of shockable rhythm and prehospital arrest were analyzed. The rates of assessment of vital signs were 89.0%, the rate of level of consiousness was 99.5%. Just 6.0% were communicated with medical director providing the prehospital care. The frequency of defibrillation was performed 58.5%. Conclusion : Survival rate was higher in defibrillation group than that of nondefibrillation group(20.5% vs 2.4%, p=0.000).

Prevalence of Human Papillomavirus in Women from Saudi Arabia

  • Turki, Rola;Sait, Khalid;Anfinan, Nisreen;Sohrab, Sayed Sartaj;Abuzenadah, Adel Mohammed
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권5호
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    • pp.3177-3181
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    • 2013
  • Background: Human papillomavirus (HPV) infection is the main causes of cervical cancer in women worldwide. The goal of the present study was to determine the prevalence and distribution of HPV genotypes in women from Saudi Arabia. Recently, several HPV detection methods have been developed, each with different sensitivities and specificities. Methods: In this study, total forty cervical samples were subjected to polymerase chain reaction and hybridization to BioFilmChip microarray assessment. Results: Human papillomavirus (HPV) infections were found in 43% of the specimens. The most prevalent genotypes were HPV 16 (30%) HPV 18 (8.0%) followed by type HPV 45, occurring at 5.0%. Conclusion: Our finding showed the HPV infection and prevalence is increasing at alarming rate in women of Saudi Arabia. There was no low risk infection detected in the tested samples. The BioFilmChip microarray detection system is highly accurate and suitable for detection of single and multiple infections, allowing rapid detection with less time-consumption and easier performance as compared with other methods.

Decision support system for underground coal pillar stability using unsupervised and supervised machine learning approaches

  • Kamran, Muhammad;Shahani, Niaz Muhammad;Armaghani, Danial Jahed
    • Geomechanics and Engineering
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    • 제30권2호
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    • pp.107-121
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    • 2022
  • Coal pillar assessment is of broad importance to underground engineering structure, as the pillar failure can lead to enormous disasters. Because of the highly non-linear correlation between the pillar failure and its influential attributes, conventional forecasting techniques cannot generate accurate outcomes. To approximate the complex behavior of coal pillar, this paper elucidates a new idea to forecast the underground coal pillar stability using combined unsupervised-supervised learning. In order to build a database of the study, a total of 90 patterns of pillar cases were collected from authentic engineering structures. A state-of-the art feature depletion method, t-distribution symmetric neighbor embedding (t-SNE) has been employed to reduce significance of actual data features. Consequently, an unsupervised machine learning technique K-mean clustering was followed to reassign the t-SNE dimensionality reduced data in order to compute the relative class of coal pillar cases. Following that, the reassign dataset was divided into two parts: 70 percent for training dataset and 30 percent for testing dataset, respectively. The accuracy of the predicted data was then examined using support vector classifier (SVC) model performance measures such as precision, recall, and f1-score. As a result, the proposed model can be employed for properly predicting the pillar failure class in a variety of underground rock engineering projects.

Korean Brain Tumor Society Consensus Review for the Practical Recommendations on Glioma Management in Korea

  • Chul-Kee Park;Jong Hee Chang
    • Journal of Korean Neurosurgical Society
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    • 제66권3호
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    • pp.308-315
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    • 2023
  • Recent updates in genomic-integrated glioma classification have caused confusion in current clinical practice, as management protocols and health insurance systems are based on evidence from previous diagnostic classifications. The Korean Brain Tumor Society conducted an electronic questionnaire for society members, asking for their ideas on risk group categorization and preferred treatment for each individual diagnosis listed in the new World Health Organization (WHO) classification of gliomas. Additionally, the current off-label drug use (OLDU) protocols for glioma management approved by the Health Insurance Review and Assessment Service (HIRA) in Korea were investigated. A total of 24 responses were collected from 20 major institutes in Korea. A consensus was reached on the dichotomic definition of risk groups for glioma prognosis, using age, performance status, and extent of resection. In selecting management protocols, there was general consistency in decisions according to the WHO grade and the risk group, regardless of the individual diagnosis. As of December 2022, there were 22 OLDU protocols available for the management of gliomas in Korea. The consensus and available options described in this report will be temporarily helpful until there is an accumulation of evidence for effective management under the new classification system for gliomas.

고준위폐기물처분장 공학적방벽시스템의 열-수리-역학적 복합거동 해석 모델 개발 현황 (Current Status of the Numerical Models for the Analysis of Coupled Thermal-Hydrological-Mechanical Behavior of the Engineered Barrier System in a High-level Waste Repository)

  • 조원진;김진섭;이창수;최희주
    • 방사성폐기물학회지
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    • 제10권4호
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    • pp.281-294
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    • 2012
  • 현재까지 개발된 고준위폐기물 심지층처분장의 열-수리-역학적 복합거동 해석을 위한 전산 코드의 현황을 조사하고, 문헌에 보고된 각 코드에 의한 계산치와 현장실험 측정치의 비교 결과를 이용하여, 기존 전산 코드들의 신뢰도를 분석하였다. 개발된 전산코드들은 완충재가 없는 처분장에서는 붕괴열에 따른 암반의 열-수리-역학적 거동을 비교적 잘 모사하였으나, 포화 경암층에 위치한 완충재가 존재하는 처분장의 공학적방벽시스템 내에서 일어나는 열-수리-역학적 복합거동의 예측은 만족스럽지 못하였다. 현재 제안된 열-수리-역학적 복합거동 해석모델을 고준위폐기물 처분장 공학적방벽시스템의 거동 해석에 적용하기 위해서는 완충재 내의 수분함량 및 전 압력 분포를 보다 정교하게 모사할 수 있도록 수학적 모델의 개선이 필요하다.

ISA를 적용한 국회전자도서관 품질 평가와 개선방안 수립 (A Study on the Evaluation and Improvement of the Korean National Assembly Digital Library by Applying ISA(Importance-Satisfaction Analysis))

  • 곽승진;정영미;김진묵;배경재;임미경
    • 한국문헌정보학회지
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    • 제45권3호
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    • pp.327-343
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    • 2011
  • 본 연구는 국회전자도서관의 품질을 평가하고 개선방안을 수립하기 위하여 평가 도구를 설계하여 품질을 측정하였고, 개선방안 도출을 위해 ISA(Importance-Satisfaction Analysis) 기법을 적용하였다. 국회전자도서관 품질 평가 도구는 선행연구들에 기반하여 콘텐츠, 서비스, 그리고 시스템의 품질 차원으로 구성하였고 각 차원의 세부적인 항목은 선행연구 및 이용자들의 요구사항 분석을 통해 설계되었다. 각 세부 항목에 대한 측정지표에는 DigiQUAL에서 사용하고 있는 중요도와 만족도가 사용되었다. 국회전자도서관 품질 평가는 질문지법을 통해 수집된 이용자 270명의 응답을 사용하여 Excel 2007과 PASW Statistics 18로 분석하였다. 그리고 측정된 품질 평가 값을 사용하여 국회전자도서관 개선방안 수립을 위해 ISA기법을 적용하였고 그 결과 국회전자도서관 품질 차원 및 세부항목들 중에서 유지, 집중, 저순위, 그리고 과잉 품질 영역을 도출하였다.

전산화 인지프로그램 적용이 뇌졸중 환자의 인지기능과 일상생활활동에 미치는 영향 (The Effect of Computerized Cognitive Program on Cognitive Function and Activities of Daily Living of Stroke Patients)

  • 장철;배원식
    • 대한통합의학회지
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    • 제9권4호
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    • pp.49-58
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    • 2021
  • Purpose : This study investigates the effects of the application of traditional occupational therapy and the korean computerized cognition training system on the cognitive function and performance of daily activities of stroke patients with cognitive impairment. Methods : From inpatients referred for rehabilitation treatment at L Rehabilitation Hospital located in Busan, 20 patients diagnosed with stroke from April 05. 2021 to May 02. 2021 (study period) were selected, They were divided into two, an experimental group consisting of 10 subjects who underwent a computerized cognitive rehabilitation program and traditional occupational therapy in combination and a control group of 10 subjects who underwent traditional occupational therapy alone. In order to measure the cognitive function of the subjects before the intervention, two assessment tests were conducted: a Neurobehavioral Cognitive Status Examination (NCSE), which evaluates stroke-related cognitive ability, and a Functional Independence Measure (FIM) test, which evaluates life activities. Then, both groups received a total of 20 training sessions at 30 minutes per session, five times a week for four weeks. Results : A statistically significant difference was found in cognitive function between before and after the cognitive training for both the experimental group and the control group. For the FIM scores, statistically significant differences were observed after intervention in the categories of handling personal matters and social cognition, and in the total score. The average scores of the remaining items also improved. Conclusion : The results of this study showed that both the computerized cognition rehabilitation program and the traditional occupational therapy had a positive effect on the improvement of cognitive function in stroke patients.

Assessment of dentists' subjective satisfaction with a newly developed device for maxillary sinus membrane elevation by the crestal approach

  • Kim, Young-Kyun;Cho, Yong-Seok;Yun, Pil-Young
    • Journal of Periodontal and Implant Science
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    • 제43권6호
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    • pp.308-314
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    • 2013
  • Purpose: The purposes of this study were to assess the dentists' subjective satisfaction with the crestal approach sinus (CAS) kit, a device for maxillary sinus membrane elevation by the crestal approach using a special drilling system and hydraulic pressure, and to summarize the subjective satisfaction of dental implants placed after a sinus lift procedure with the CAS kit. Methods: Thirty dental clinicians who had experience with dental implant placement after a sinus lift procedure with the CAS kit from June 2010 to May 2012 were included in this study. The questionnaire for the evaluation of the dentists' subjective satisfaction with the CAS kit was sent to the respondents and returned. The questionnaire was composed of two main parts. The first part was related to the sinus membrane perforation rate. The second part was related to the dentists' subjective satisfaction with the CAS kit. Results: A total of 28 dentists answered the questionnaire. Among 924 implant cases, sinus membrane perforation occurred in 38 cases (4.1%). Among the 28 dentists, 26 dentists (92.9%) were satisfied or very satisfied with the CAS kit. In particular, 24 dentists (85.7%) reported that safety, cutting performance, and user-friendliness of the CAS drill were advantages of the CAS kit. However, 7 dentists (25%) did not routinely use the hydraulic lifter for sinus membrane elevation. Conclusions: From the survey, it was shown that the respondents were generally satisfied with the CAS kit and that the cutting performance and safety of the drill component were considered strengths of the CAS kit.

정부지원 중소기업 컨설팅 사업의 재무적 성과분석 : 기업성장지원센터 사업 기준 (Financial Performance Analysis of Government-Supporting Consulting Business to Small and Medium Enterprises : Focused on Corporate Growth Supporting Center in KICOX)

  • 정해일;최정혜;이상열
    • 산업경영시스템학회지
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    • 제40권4호
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    • pp.38-45
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    • 2017
  • As the competitiveness of SMEs (small and medium enterprises) is getting more and more improved and globalized, the government provides various consulting services to secure the competitiveness of small and medium firms and support stable growth. However, the assessment of the result from the government's support is generally focused on non-financial factors, such as customer satisfaction and analysis of improvement effect. This paper is in regards to the statistical analysis of how much the government's support in the form of providing consulting services contributes to financial outcomes in terms of profitability and growth. ROA (return on asset) and ROS (return on sales), which are investment profitability and sales profitability respectively, are chosen as an indicator of profitability. For analysis of growth, sales revenue and total asset growth are used. The samples are 44 corporations which are supported by government, and 150 corporations which are selected for comparison, with corporate growth support center program by the Ministry of Trade, Industry, and Energy chosen as the consulting model. After gathering the yearly balance sheets and income statements of the samples from CRETOP, Korea Enterprise Data, the analysis is conducted in the way of identifying the statistical significance of financial difference in the same period between corporates taking consulting services and corporates which have not, and the difference of financial outcomes from the corporates taking consulting services before and after consulting services. As a result, in terms of business growth, it is turned out to have positive difference both in growth ratio and profitability compared to the compared corporations at the significant level. Therefore, it is obvious that the consulting program which government provides to SMEs have direct influence practically to the corporates' management performance.