• 제목/요약/키워드: Heterogeneity measure

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Anesthetic efficacy of primary and supplemental buccal/lingual infiltration in patients with irreversible pulpitis in human mandibular molars: a systematic review and meta-analysis

  • Gupta, Alpa;Sahai, Aarushi;Aggarwal, Vivek;Mehta, Namrata;Abraham, Dax;Jala, Sucheta;Singh, Arundeep
    • Journal of Dental Anesthesia and Pain Medicine
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    • 제21권4호
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    • pp.283-309
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    • 2021
  • Achieving profound anesthesia in mandibular molars with irreversible pulpitis is a tedious task. This review aimed at evaluating the success of buccal/lingual infiltrations administered with a primary inferior alveolar nerve block (IANB) injection or as a supplemental injection after the failure of the primary injection in symptomatic and asymptomatic patients with irreversible pulpitis in human mandibular molars. The review question was "What will be the success of primary and supplemental infiltration injection in the endodontic treatment of patients with irreversible pulpitis in human mandibular molars?" We searched electronic databases, including Pubmed, Scopus, and Ebsco host and we did a comprehensive manual search. The review protocol was framed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) checklist. We included clinical studies that evaluated and compared the anesthetic outcomes of primary IANB with primary and/or supplementary infiltration injections. Standard evaluation of the included studies was performed and suitable data and inferences were assessed. Twenty-six studies were included, of which 13 were selected for the meta-analysis. In the forest plot representation of the studies evaluating infiltrations, the combined risk ratio (RR) was 1.88 (95% CI: 1.49, 2.37), in favor of the secondary infiltrations with a statistical heterogeneity of 77%. The forest plot analysis for studies comparing primary IANB + infiltration versus primary IANB alone showed a low heterogeneity (0%). The included studies had similar RRs and the combined RR was 1.84 (95% CI: 1.44, 2.34). These findings suggest that supplemental infiltrations given along with a primary IANB provide a better success rate. L'Abbe plots were generated to measure the statistical heterogeneity among the studies. Trial sequential analysis suggested that the number of patients included in the analysis was adequate. Based on the qualitative and quantitative analyses, we concluded that the infiltration technique, either as a primary injection or as a supplementary injection, given after the failure of primary IANB, increases the overall anesthetic efficacy.

Physio-mechanical and X-ray CT characterization of bentonite as sealing material in geological radioactive waste disposal

  • Melvin B. Diaz;Sang Seob Kim;Gyung Won Lee;Kwang Yeom Kim;Changsoo Lee;Jin-Seop Kim;Minseop Kim
    • Geomechanics and Engineering
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    • 제34권4호
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    • pp.449-459
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    • 2023
  • The design and development of underground nuclear waste repositories should cover the performance evaluation of the different components such as the construction materials because the long term stability will depend on their response to the surrounding conditions. In South Korea, Gyeonju bentonite has been proposed as a candidate to be used as buffer and backfilling material, especially in the form of blocks to speed up the construction process. In this study, various cylindrical samples were prepared with different dry density and water content, and their physical and mechanical properties were analyzed and correlated with X-ray CT observations. The main objective was to characterize the samples and establish correlations for non-destructive estimation of physical and mechanical properties through the utilization of X-ray CT images. The results showed that the Uniaxial Compression Strength and the P-wave velocity have an increasing relationship with the dry density. Also, a higher water content increased the values of the measure parameters, especially for the P-wave velocity. The X-ray CT analysis indicated a clear relation between the mean CT value and the dry density, Uniaxial Compression Strength, and P-wave velocity. The effect of the higher water content was also captured by the mean CT value. Also, the relationship between the mean CT value and the dry density was used to plot CT dry densities using CT images only. Moreover, the histograms also provided information about the samples heterogeneity through the histograms' full width at half maximum values. Finally, the particle size and heterogeneity were also analyzed using the Madogram function. This function identified small particles in uniform samples and large particles in some samples as a result of poor mixing during preparation. Also, the μmax value correlated with the heterogeneity, and higher values represented samples with larger ranges of CT values or particle densities. These image-based tools have been shown to be useful on the non-destructive characterization of bentonite samples, and the establishment of correlations to obtain physical and mechanical parameters solely from CT images.

이질적 목적을 지닌 R&D 사업들을 위한 달성지수 기반의 상대적 평가기법 (Attainment Index-based Relative Evaluation Method for R&D Programs with Heterogeneous Objectives)

  • 정욱;임성민;김윤종;정산기
    • 산업경영시스템학회지
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    • 제32권2호
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    • pp.29-37
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    • 2009
  • National R&D programs play an important role in the development of a country in this age of the knowledge economy. Since many numbers of R&D programs compete for limited resources such as national R&D budget, the R&D program evaluation problem is a challenging decision-making problem faced by decision makers that deal with R&D management. In this sense, DEA(Data Envelopment Analysis) has been regarded as one of the most widely accepted methods to measure the relative efficiency of productivity of R&D programs. DEA is a methodology to measure and to evaluate the relative efficiency of a homogeneous set of decision-making units(DMUs) in a process which uses multiple inputs to produce multiple outputs. However, the sample of the R&D programs could consist of two or more naturally occurring subsets, thus exhibiting clear signs of heterogeneity such as different objectives. In such situations, the fairness of DEA is limited, for the nature of the relative efficiency of a DMU is likely to be influenced by its membership in a particular subset of the sample. In this study, we propose a methodology AI-DEA(attainment index DEA) allowing for reflecting decision maker's subjective judgement on difference among different subsets of R&D programs which have heterogeneous objectives. This methodology combines AHP and Delphi in order to decide the attainmnet index of each DMU for each outputs, and apply them to DEA model. We illustrate the proposed approach with a pilot evaluation of 13 programs involving 6 different subsets of Korean National R&D programs and compares the results of the original DEA model and AI-DEA model.

Osmotic Shock에 의한 Vibrio vulnificus 사멸에 관한 연구 (Bactericidal Effect of Osmotic Shock Against Vibrio vulnificus)

  • 이준행;조순흠;정선식
    • 대한미생물학회지
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    • 제22권2호
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    • pp.109-116
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    • 1987
  • As a process to establish an effective preventive measure of V. vulnificus septicemia, bactericidal effect of distilled water against V. vulnificus was studied. When about $2.0{\times}10^7\;CFU/ml$ of V. vulnificus was inoculated in distilled water, a dramatic decrease in the number of viable bacteria by 5 to $6LOG_{10}$ was observed in 5 minutes. Bactericidal kinetic curves could be divided into the first rapid killing phase until 1 minute and the later slow killing phase after then, showing the heterogeneity of the bacterial population inoculated. When V. vulnificus was inoculated in saline solutions having various salinities, significant decrease in the number of viable bacteria was noted only at salinities under 0.2%. The higher was the concentration of NaCl, the greater was the degree of protection against osmotic shock. When glucose, NaCl, $MgCl_2$, and $CaCl_2$ were diluted with deionized water to give same osmolarities and V. vulnificus was inoculated in each of them to compare the bactericidal curves plotted during the first 5 minutes after inoculation, the protection efficiencies were in the order of $MgCl_2>CaCl_2{\gg}NaCl{\gg}glucose$. Above results indicate that treatment(or thorough washing) of contaminated sea animals or other products with distilled water can be used as a preventive measure of V. vulnificus septicemia, and divalent cations can protect V. vulnifcus to osmotic shock with high efficiency.

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비정상성 지역빈도해석을 위한 지역구분에 따른 이질성 척도 검토 (Investigation of Heterogeneity Measure for Nonstationary Regional Frequency Analysis)

  • 안현준;신주영;정태호;허준행
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2018년도 학술발표회
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    • pp.340-340
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    • 2018
  • 전 세계적으로 기후변화로 인해 나타나는 이상기후의 영향을 고려하기 위해서 수문빈도해석분야에서는 비정상성 빈도해석에 관한 연구가 활발히 진행 중이다. 자료의 비정상성을 고려하여 빈도해석을 수행하는 방법은 다양하게 연구되어오고 있는데, 그중 시간에 따른 자료의 변화를 고려할 수 있도록 기존 모형의 매개변수에 시간을 고려할 수 있는 변수를 더하여 모형을 구축하는 기법이 비정상성 빈도해석기법으로 널리 활용되고 있다. 한편, 이러한 비정상성 가정에 관련한 연구들은 주로 지점빈도해석 기법을 중심으로 개발되어왔을 뿐, 아직 지역빈도해석기법을 대상으로 시도된 비정상성 연구는 미비한 실정이다. 지역빈도해석은 수문학적 동질지역이라는 가정을 바탕으로 표본의 확장을 통해 지점빈도해석보다 비교적 안정적인 빈도해석을 수행할 수 있는 기법으로 널리 알려져 있다. 따라서 지역빈도해석에서 수문학적 동질지역의 구분은 지역빈도해석 절차 중 가장 중요한 절차라고 할 수 있다. 이러한 수문학적 동질지역 구분을 위해서는 지점별로 가지고 있는 위치 정보나 수문 자료의 통계값과 같은 해당 지점을 대표할 수 있는 인자들이 필요하다. 본 연구에서는 모의실험을 통해 경향성이 나타나는 가상의 지점 자료를 생성한 뒤, 지역구분을 통해 자료의 비정상성이 나타나는 지역의 지역구분 결과를 살펴보고 이질성 척도(heterogenity measure)를 산정하였다. 이를 바탕으로 비정상성 지역빈도해석에서 이질성 척도의 적용성을 검토하고자 한다. 본 연구의 결과는 추후 기후변화의 영향이 나타나는 수문학적 동질 및 비 동질지역의 분석 및 비정상성 지역빈도해석을 위한 기초자료로 활용될 것으로 기대된다.

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공공기관의 행정서비스품질 평가에 관한 실증적 연구 : 서울시 구청 중심으로 (An Empirical Study on Evaluation for Administrative Service Quality of Public Institution : Focused on District Offices in Seoul)

  • 박경호;이강인
    • 한국컴퓨터정보학회논문지
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    • 제14권9호
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    • pp.167-177
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    • 2009
  • 서비스품질이 기업들뿐만 아니라 공공부문에서도 재고되어지고 있는 이 시점에서 기업들의 고객중심적 서비스 품질 접근방식을 공공부문에서도 많은 관심을 가지게 되었다. 하지만 공공기관의 비즈니스 문화의 차이로 인하여 서비스품질을 개선하는 것에는 많은 애로사항이 있으며 또한 서비스 개념에는 무형성, 이질성, 비분리성 및 소멸성이 포함되어있기 때문에 서비스품질을 객관적 이게 평가하기란 매우 어려운 일이다. 따라서, 본 연구에서는 주관적 환경에서 보다 객관적이게 서비스품질을 평가하기 위해 퍼지이론과 AHP 모형을 통합한 ASQI모형을 개발하였다. ASQI모형에서의 퍼지이론은 인간의 주관적 판단과 관계되는 애매한 개념들을 평가하는데 이용되어졌고, AHP모형은 고객들이 중요하게 고려하는 서비스품질 평가요인(유형성, 신뢰성, 대응성, 확신성, 공감성)들에 대한 중요도를 파악하기 위하여 이용되어졌다.

가격인상과 용량감소에 관한 소비자 관점의 비교 연구 : 경쟁사 가격전략과 위험회피성향을 중심으로 (A Consumer-Oriented Study of Price Increases and Downsizing : Focused on Roles of Competitor's Pricing Strategy and Risk-Aversion)

  • 김혜영;강영선
    • 경영과학
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    • 제32권3호
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    • pp.55-70
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    • 2015
  • The main objective of this study is to investigate the moderating roles of the competitor's pricing strategy and the degree of consumer's risk-aversion on perceived risk and perceived benefit in responding to price increases and package downsizing. Based on Prospect Theory, several prior researches find that consumers perceive increased price as more loss than package downsizing and perceive package downsizing as more benefit than increased price. We extend these behavioral economics approach using the reference effect of competitor's pricing strategy. We focus on consumer heterogeneity on risk-aversion, measure the degree of consumer's risk-aversion, and divide the consumers into two groups of high levels of risk-aversion vs. low levels of risk-aversion. We find that the firm's pricing strategies of both price increases and package downsizing do not significantly influence the perceived benefit for relatively low risk-aversion consumers. We find that when the firm reduce the package size, relatively high risk-aversion consumers perceived more benefit and had higher purchase intention compared to price increases. We also find that the competitor's pricing strategies do not significantly influence the consumer's response for relatively low risk-aversion consumers. For relatively high risk-aversion consumers, they perceived more loss when the firm has different pricing strategy from the competitor's.

기혼여성 시간제일자리의 상태의존성(state dependence) 변화 (Part-time Jobs of Korean Married Women -The recent change in their state dependence-)

  • 정민수
    • 노동경제논집
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    • 제41권3호
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    • pp.95-128
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    • 2018
  • 본 연구는 우리나라 기혼여성들의 시간제, 전일제 등 근로형태가 오래 지속되는지 아니면 근로형태간 이동이 활발한지를 상태의존성(state dependence) 추정을 통하여 살펴보고, 최근의 변화를 분석하였다. 동태적 다항로짓모형(dynamic multinomial logit model) 추정결과 시간제와 전일제 상호간 이동성이 최근 낮아지면서 각 근로형태의 상태의존성은 강화되는 모습을 보였다. 따라서 시간제일자리는 전일제와 미취업 사이에서 근로형태간 이동을 활발하게 하는 디딤돌 또는 쉼터의 역할이 약화되고 전일제 외에 노동시장 참여 옵션을 제공하는, 전일제와는 구분된 추가적 일자리형태로 기능하고 있는 것으로 판단된다.

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Bootstrap-DEA를 이용한 해양수산 인재 양성교육의 효율성 분석에 관한 연구 (The Analysis of Oceans and Fisheries Human Resources Development Education Efficiency Using Bootstrap-DEA)

  • 김종천;김병호
    • 수산경영론집
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    • 제47권1호
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    • pp.63-86
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    • 2016
  • The purpose of this study is to investigate production efficiency of Oceans and Fisheries Human Resources Development Programs Efficiency using Bootstrap-DEA. The study extracts 33 officials curriculum, 11 fisheries managers curriculum for its analytical. First, the study estimates technical, pure technical, and scale efficiency of each curriculums based on traditional DEA under the assumption of CRS and VRS. 8(official 7, managers 1) curriculums are identified as efficient DMUs under the CCR-model, and 13(official 10, managers 3) under the BCC-model. We provide inputs that allow inefficient curriculum to be efficient DMUs on a production frontier, and a reference set for their bench-marking. Second, rank test, Wilcoxon-Mann-Whitney test to find a statistical significance of heterogeneity existing in efficiences between Bootstrap-DEA tenical vs Bootstrap-DEA pure technical was no significant difference. We have identified that G10, 11, 12 13, 25, 31, 33, 39 curriculums are the most efficiently produced in the technical and pure technical efficiency. Also we managed to measure the inefficiency which exists in efficiently produced curriculums when estimating the bias corrected efficiency scores. In Technical efficiency, Operation and facility was significant at the 10%. In Pure technical efficiency, facility was significant at the 10%.

제방 안전관리를 위한 Flex센서와 FBG센서의 적용성 검토 (Suitability Examination of Flex sensor and FBG Sensor for Levee Safety Management)

  • 이인제;이은태;강정훈;김동민;장기태
    • 한국수자원학회논문집
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    • 제41권11호
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    • pp.1135-1142
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    • 2008
  • 하천제방의 붕괴 요인중 구조물(배수통문) 주변 제방의 붕괴는 전체 요인의 l0% 이상을 차지하고 있으며, 특히 2002년 홍수시 낙동강에서 발생한 제방 유실 지점은 거의 배수통문 주위에서 발생하였다. 이러한 제방 파괴는 이질 재료인 통문 구조물과 제체 접합부 사이에 공극이나 공동이 형성된 후 홍수시 내부 침식으로 인해 공동이 확대되어 발생하는 파괴구조를 가지고 있다. 이러한 상황에서 하천제방의 안전관리를 위해 배수통문 주변의 공동발생 여부 혹은 공동내의 흐름 인지 등을 목적으로 한 연구가 진행되고 있으며, 본 연구에서는 Flex센서와 Fiber bragg grating 센서의 변이 계측에 대한 실험을 통해 두 센서의 특징을 파악하고, 하천제방의 안전관리를 위해 보다 적합한 센서의 결정이 가능하도록 하였다. 실험결과 현 시점에서 변이 계측과 관련하여 계측치의 일관성, 미소변이 계측 등 Flex센서의 단점을 보완할 수 있는 FBG센서의 여러 특징을 확인할 수 있었다.