• 제목/요약/키워드: CVI

검색결과 192건 처리시간 0.024초

대각선 횡단보도의 정량적 설치기준에 관한 연구 (Development of Warrant for Scrambled Pedestrian Crossing)

  • 손규홍;장명순;김영찬
    • 대한교통학회지
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    • 제15권2호
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    • pp.105-122
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    • 1997
  • 본 연구는 대각선 횡단보도의 정량적 설치기준을 정립하기 위하여 이상적인 조건에서의 교차로 각현시별 임계차선 교통량의 합($\sum_i$ CVi)을 600~1,800대로 변화를 주어 실험적 시뮬레이션 방법을 적용하였다. TRANSTY-7F 모형을 이용한 교차로 평균차량 지체도와 본 연구에서 정립한 보행지체모형을 이용한 교차로 평균 보행지체도와의 관계를 변수로 하여 대각선 횡단보도의 정량적 설치기준을 각 조건별로 산정한 결과 다음과 같은 결론이 도출되었다. 첫째, 동시신호시 교통량과 보행량의 비율이 1:1일 경우 대각횡단비율 20~40%에서는 $\sum_i$ CVi=1,050~1,150대 이하에서 대각선 횡단보도를 설치시 지체도 감소에 대한 편익을 얻을 수 있다. 둘째, 동시신호시 교통량과 보행량의 비율이 1:2일 경우 대각횡단비율 20~40%에서는 $\sum_i$ CVi=1,150~1,200대 이하에서 대각선 횡단보도를 설치시 지체도 감소에 대한 편익을 얻을 수 있다. 셋째, 선행 좌회전신호시 교통량과 보행량의 비율이 1:1일 경우 대각횡단비율 20~40%에서는 $\sum_i$ CVi=600~750대 이하에서 대각선 횡단보도를 설치시 지체도 감소에 대한 편익을 얻을 수 있다. 넷째, 선행 좌회전신호시 교통량과 보행량의 비율이 1:2일 겨우 대각횡단비율 20~40%에서는 $\sum_i$ CVi=750~900대 이하에서 대각선 횡단보도를 설치시 지체도 감소에 대한 편익을 얻을 수 있다.

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Whisker Growing Assisted 화학침착 공정으로 제조된 SiCf/SiC 복합체의 파괴거동과 기계강도 평가 (Fracture Behaviors and Mechanical Properties of SiCf/SiC Composites Prepared by the Whisker Growing Assisted CVI Process)

  • 강석민;김원주;윤순길;박지연
    • 한국세라믹학회지
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    • 제46권5호
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    • pp.484-487
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    • 2009
  • $SiC_f$/SiC composites with whiskers and pyrolytic carbon (PyC) coated whiskers in the matrix were fabricated for enhancement of the fracture behaviors by the whisker growing assisted chemical vapor infiltration (WA-CVI) process, respectively. $SiC_f$/SiC composites were also prepared by the conventional CVI process as reference material. The mechanical properties and fracture behaviors were analyzed by comparison of the two types of composites prepared by WA-CVI and conventional CVI. The densities of $SiC_f$/SiC composites were in the range of $2.6{\sim}2.65g/cm^3$. The flexural strengths of composite with whiskers and with those coated by PyC were 650 MPa and 600 MPa, respectively. The tensile strength of composites with whiskers was ${\sim}285$ MPa.

A Systematic Review on the Management of Cortical Visual Impairment

  • Myunghwa Oh;Hyunjoong Kim
    • Physical Therapy Rehabilitation Science
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    • 제13권2호
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    • pp.196-204
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    • 2024
  • Objective: Cortical Visual Impairment (CVI) is a leading cause of pediatric blindness and the most common form of pediatric visual disability, particularly prevalent among children with cerebral palsy (CP). This systematic review synthesizes the latest research on various interventions for managing CVI, focusing on studies published in the last decade. Design: A systematic review Methods: A comprehensive search was conducted in March 2024 across several databases including MEDLINE, CINAHL, Embase, and Web of Science. Studies were selected based on inclusion criteria set under the PICOSD framework and were limited to those involving human subjects, published in English, and conducted within the past ten years. The selected studies included randomized controlled trials, observational studies, and case reports focusing on rehabilitation, therapy, and surgical interventions for CVI. Results: Out of 221 studies screened, 5 met the inclusion criteria and were reviewed in detail. These studies covered a range of interventions including physiotherapy, sensory integration training, visual training programs, neuromotor rehabilitation, and surgical procedures aimed at improving visual function and overall quality of life for CVI patients. Conclusions: The studies demonstrate the potential benefits of structured, early intervention programs that incorporate family involvement and are tailored to the unique needs of children with CVI. However, there remains a significant need for further research to establish evidence-based practices in this field.

펄스화학기상침트법에 의한 탄소/탄소 복합재료의 치밀화에 있어서 가스유지시간 유무의 영향 (Densification of Carbon/Carbon Composites by Pulse CVI with and without Residence)

  • 이용근;류호진;박희동
    • 한국세라믹학회지
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    • 제33권8호
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    • pp.935-941
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    • 1996
  • Two-dimensional carbon/carbon preforms made of PAN-based carbon yarn and phenolic resin were densified with pyrolysis of propane by pulse chemical vapor infiltration where repeated the cycle of gas introduction residence and evacuation. Maximim density increment was 14% when infiltration temperature and time were 100$0^{\circ}C$ and 21.25 hrs respectively. The distribution of deposits of pyrocarbon by this process has been occurred uniformly in the bottom middle and top of carbon/carbon composite preform Pulse CVI with residence is most effective in increasing density and shortening infiltration time among isothermal CVI and pulse CVI with and without residence.

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가정용 Sensory Processing Measure(SPM)의 국내적용을 위한 번역연구 (Translation and Cross-Cultural Adaptation Study on a Korean of Sensory Processing Measure Home Form)

  • 이혜림;유은정;김경미
    • 대한감각통합치료학회지
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    • 제19권3호
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    • pp.22-31
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    • 2021
  • 목적 : 본 연구의 목적은 아동의 감각처리능력을 확인하는데 사용하는 가정용 Sensory Processing Measure(SPM)을 우리나라에 적용하기 위해 번역과정을 거친 후 내용타당도를 알아보는 것이다. 연구방법 : 내용타당도 연구를 위해 번역, 역번역 과정에서 항목을 수정하였고, 전문가 집단을 구성하여 내용타당도를 검증하였다. 전문가 집단은 각 지역별 작업치료학과 교수 3명을 전문가 집단으로 구성하여 내용타당도를 확인하였다. 내용타당도는 각 항목에 대하여 의미성와 구조성으로 나누어 4점 척도로 실시하였으며 1점은 매우 타당하지 않음, 2점은 타당하지 않음, 3점은 타당함, 4점은 매우 타당함으로 점수화하였다. 역번역은 이중언어를 사용하는 2명이 참여하여 2개의 역번역본에서 일치하는 않는 부분을 확인한 다음 전문가 집단에서 토의 후 보완하였다. 이렇게 번역된 한국어판은 작업치료를 받고 있는 아동의 부모 13명을 대상으로 이해도 검증을 실시하였다. 결과 : 전문가 집단을 대상으로 원본 SPM과 한국어로 번역한 SPM을 비교한 결과 평균 3.54± .74(리커트 4점 척도), 의미성에 대한 평균방식의 척도 내용타당도 지수(Scale-level Content Validity Index; S-CVI/Avg)는 .92, 구조성에 대한 평균방식의 척도 내용타당도 지수(S-CVI/Avg)는 .86이었다. 역번역 결과, 내용 일치도는 평균 3.77± .47로 나타나 내용이 일치한다고 볼 수 있다. 역번역 및 수정을 거친 SPM을 부모 집단을 대상으로 이해도 검증 결과 평균 3.48 ± .63(리커트 4점 척도)이었으며 평균방식의 척도 내용타당도 지수(S-CVI/Avg)는 .94로 나타났다. 결론 : 본 연구는 타문화권에서 개발된 SPM을 번역 및 역번역 과정을 거쳐 내용타당도를 검증함으로써 한국어판 가정용 SPM을 우리 문화권에 사용하기 위한 기초자료를 제시하는데 연구의 의의가 있다.

A Study on Ultrasonic Evaluation of Material Defects in Carbon/carbon Composites

  • Im, Kwang-Hee;David K. Hsu;Cha, Cheon-Seok;Sim, Jae-Ki;Yang, In-Young
    • Journal of Mechanical Science and Technology
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    • 제16권12호
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    • pp.1652-1663
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    • 2002
  • It is desirable to perform nondestructive evaluation to assess material properties and part homogeneity because manufacturing of carbon/carbon (C/C) composites requires complicated and costly processes. In this work several ultrasonic techniques were applied to carbon/carbon composites for the evaluation of spatial variations in material properties that are attributable to the manufacturing process. In a large carbon/carbon composite manufactured by chemical vapor infiltration (CVI) method, the spatial variation of ultrasonic velocity was measured and found to be consistent with the densification behavior in CVI process in order to increase the density of C/C composites. Ultrasonic velocity and attenuation depend on a density variation of materials. Low frequency through-transmission scans based on both amplitude and time-of-flight of the ultrasonic pulse were used for mapping out the material property inhomogeneity These results were compared with that obtained by dry-coupling ultrasonics. Pulse-echo C-scans was used to image near-surface material property anomalies such as the placement of spacers between disks during CVI. Also, optical micrograph had been examined on the surface of C/C composites using a destructive way.

치매 간호 표준 개발 (Development of Dementia Care Standards)

  • 하주영
    • 대한간호학회지
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    • 제40권5호
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    • pp.631-641
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    • 2010
  • Purpose: This study was done to develop standards for dementia care as a baseline for professional nurses to provide a framework for dementia care evaluation Methods: The dementia care standards were developed through a literature review and focus group discussions. According to the Delphi method, the data analysis was conducted using the Content Validity Index (CVI). Results: The final set of 18 standards on dementia care was developed through one round of CVI. The standards included four structural standards: 'Organization of nursing system', 'Operating system', 'Management of human resources', 'Management of material resources', 13 procedural standards: 'Advanced assessment', 'Nursing diagnosis', 'Nursing plam', 'Advanced nursing implementation', 'Evaluation', 'Education', 'Research', 'Consultation', 'Counseling and cooperation', 'Development of specialty', 'Utilizing resources', 'Nursing quality assurance', 'Ethics', and one standard concerning outcome ('Evaluation of nursing tasks in care of patients with dementia'). The final set of 55 criteria on care of patients with dementia was confirmed through two rounds of CVI. The final 171 indicators were confirmed through four rounds of CVI. Conclusion: These dementia care standards provides a framework that allows registered nurses to clarify their roles and tasks in the care of patients with dementia and provides evaluation criteria.

전문직 간 핵심역량 중요성 인식 측정도구의 신뢰도와 타당도 검증 (Reliability and Validity of Perception on Importance of Interprofessional Core Competencies(PI-ICCP) Scale)

  • 홍민주;전민경
    • 보건의료산업학회지
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    • 제13권4호
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    • pp.253-263
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    • 2019
  • Objectives: This study evaluated the perception on importance of interprofessional core competencies (PI-ICCP) scale. Methods: Data were collected from 353 college students of health. Content validity was tested using the content validity index for individual items(I-CVI) and for scale(S-CVI). Criterion validity was tested using the professional competencies scale developed by Choi. Reliability was evaluated using Cronbach's coefficient alpha. The goodness-of-fit of the construct validity was determined through exploratory and confirmatory factor analyses. Results: The I-CVI of each item was .8 or higher for all items, and the S-CVI was .98. The reliability of the PI-IPCC was Cronbach's α=.98. The goodness-of-fit indices of the model were χ2=1811.54(p<.001), the comparative fit index (CFI)=.91, and root mean square error of approximation (RMSEA)=.08, which satisfied the criteria. Conclusions: The construct and criterion-related validity of the perception for PI-ICCP scale were a good fit, so the instrument is appropriate for measuring perception on importance of interprofessional core competencies. Further research will be required using this instrument to investigate perception of interprofessional core competencies of health professionals.

델파이 조사를 이용한 소아·청소년의 우식위험평가 문항 개발 (Development of caries risk assessment for children and adolescents using Delphi survey)

  • 이지현;이수영
    • 한국치위생학회지
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    • 제22권6호
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    • pp.531-539
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    • 2022
  • Objectives: This study aimed to design a CRA questionnaire specifically for Korean children and adolescents based on the results of two Delphi survey completed by dental professionals. Methods: Based on the CAMBRA® CRA tool, updated in 2019, we constructed a questionnaire on the oral environment and behavior of children and adolescents. Then, the CVR and I-CVI were evaluated using the results of the first and second Delphi surveys involving 20 professionals. Results: After the first Delphi survey, six items were considered invalid because their CVR and I-CVI were below the recommended values of 0.42 and 0.78, respectively. After receiving feedback from the professional panels, nine items were removed. In the second Delphi survey, the questionnaire contained a total of 21 items, all of which showed good CVR and I-CVI. After modifications based on the opinions of professional panels, the questionnaire was finalized to have 21 questions. Conclusions: The finalized questionnaire with 21 items, based on the opinions of professional panels, showed excellent CVR and I-CVI for all the items. Structured programs with updated guidelines must be developed for Korean children and adolescents in further studies.