• Journal of Dental Anesthesia and Pain Medicine
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• v.21 no.4
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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.

• Geomechanics and Engineering
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• v.34 no.4
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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 μ_max 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.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.2
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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.

• The Journal of the Korean Society for Microbiology
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• v.22 no.2
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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.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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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.

• Journal of the Korea Society of Computer and Information
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• v.14 no.9
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• pp.167-177
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• 2009

As the service quality has been reconsidered in public sector as well as private enterprises, the need for public sectors to adopt principle and practices of private sectors is concerned with customer-focused approach, the different business culture of public service organizations makes it difficult to improve service qualify. Also, Since concept of service contains intangibility, heterogeneity, Simultaneousness and perishability, it makes peoples more difficult to measure service quality. Therefore, this study proposes synthetic Administrative Service duality Index(ASQI) using fuzzy set theory and analytic hierarchy process to evaluate the service qualify in subjective environment. In ASQI model, Fuzzy set theory helps to measure the ambiguity of concepts that are relative to human being's subjective judgement. Also, this study utilizes AHP method to evaluate the preference weights of service quality dimensions (tangibility, reliability, responsiveness, assurance, empathy) for customers.

• Korean Management Science Review
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• v.32 no.3
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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.

• Journal of Labour Economics
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• v.41 no.3
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• pp.95-128
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• 2018

This study tries to measure the change in the state dependence of the three labor supply choices (part-time, full-time, and the state of unemployed) in Korean married women's labor market by estimating the dynamic multinomial logit model based on MSL (maximum simulated likelihood) method. A component representing individual's unobserved characteristics has been introduced, because it is crucial to control for unobserved heterogeneity in assessing the state dependence. Estimation results show that the state dependences of the three alternatives have strengthened recently. Therefore, part-time job has become more likely to be functioning as an extra option to participate in labor market rather than a bridge(stepping stone) or shelter between unemployment and full-time job.

• The Journal of Fisheries Business Administration
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• v.47 no.1
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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%.

• Journal of Korea Water Resources Association
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• v.41 no.11
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• pp.1135-1142
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• 2008

Collapse of the levee surrounding structure(culvert) accounts for l0 % of collapse factors of the river levees. In particular, in 2002, the levee collapse that happened at "Nakdong River" at flood usually happened around culverts. This levee collapse has mechanism that the cavity expands with internal erosion at flood after the pore and cavity are formed between culvert and levee copula which are heterogeneity material. The study regarding the cavity or flowing detection around a culvert for safety management of a river levee is in the proceeding. In this study, the characteristic of two sensors could be figured out through an experiment about displacement measure of Flex sensor and FBG sensor and the decision of more suitable sensor was possible for safety supervision of river levee. According to an experiment result, several characteristics of FBG sensor could be known in consistency of the measure data and minute displacement measure part regarding displacement measure and this characteristic may supplement a shortcoming of Flex sensor at this time.