• Structural Engineering and Mechanics
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• 제90권4호
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• pp.371-390
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• 2024

Investigating the impact of openings on the structural behavior of ferrocement I-beams with two distinct types of reinforcing metallic and non-metallic meshes is the primary goal of the current study. Up until failure, eight 250x200x2200 mm reinforced concrete I-beams were tested under flexural loadings. Depending on the kind of meshes used for reinforcement, the beams are split into two series. A control I-beam with no openings and three beams with one, two, and three openings, respectively, are found in each series. The two series are reinforced with three layers of welded steel meshes and two layers of tensar meshes, respectively, in order to maintain a constant reinforcement ratio. Structural parameters of investigated beams, including first crack, ultimate load, deflection, ductility index, energy absorption, strain characteristics, crack pattern, and failure mode were reported. The number of mesh layers, the volume fraction of reinforcement, and the kind of reinforcing materials are the primary factors that vary. This article presents the outcomes of a study that examined the experimental and numerical performance of ferrocement reinforced concrete I-beams with and without openings reinforced with welded steel mesh and tensar mesh separately. Utilizing ANSYS-16.0 software, nonlinear finite element analysis (NLFEA) was applied to illustrate how composite RC I-beams with openings behaved. In addition, a parametric study is conducted to explore the variables that can most significantly impact the mechanical behavior of the proposed model, such as the number of openings. The FE simulations produced an acceptable degree of experimental value estimation, as demonstrated by the obtained experimental and numerical results. It is also noteworthy to demonstrate that the strength gained by specimens without openings reinforced with tensar meshes was, on average, 22% less than that of specimens reinforced with welded steel meshes. For specimens with openings, this value is become on average 10%.

• 대한임상검사과학회지
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• 제37권2호
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• pp.65-70
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• 2005

Those specifications of the CLIA analytical tolerance limits are consistent with the performance goals in Six Sigma Quality Management. Six sigma analysis determines performance quality from bias and precision statistics. It also shows if the method meets the criteria for the six sigma performance. Performance standards calculates allowable total error from several different criteria. Six sigma means six standard deviations from the target value or mean value and about 3.4 failures per million opportunities for failure. Sigma Quality Level is an indicator of process centering and process variation total error allowable. Tolerance specification is replaced by a Total Error specification, which is a common form of a quality specification for a laboratory test. The CLIA criteria for acceptable performance in proficiency testing events are given in the form of an allowable total error, TEa. Thus there is a published list of TEa specifications for regulated analytes. In terms of TEa, Six Sigma Quality Management sets a precision goal of TEa/6 and an accuracy goal of 1.5 (TEa/6). This concept is based on the proficiency testing specification of target value +/-3s, TEa from reference intervals, biological variation, and peer group median mean surveys. We have found rules to calculate as a fraction of a reference interval and peer group median mean surveys. We studied to develop total error allowable from peer group survey results and CLIA 88 rules in US on 19 items TP, ALB, T.B, ALP, AST, ALT, CL, LD, K, Na, CRE, BUN, T.C, GLU, GGT, CA, phosphorus, UA, TG tests in chematology were follows. Sigma level versus TEa from peer group median mean CV of each item by group mean were assessed by process performance, fitting within six sigma tolerance limits were TP ($6.1{\delta}$/9.3%), ALB ($6.9{\delta}$/11.3%), T.B ($3.4{\delta}$/25.6%), ALP ($6.8{\delta}$/31.5%), AST ($4.5{\delta}$/16.8%), ALT ($1.6{\delta}$/19.3%), CL ($4.6{\delta}$/8.4%), LD ($11.5{\delta}$/20.07%), K ($2.5{\delta}$/0.39mmol/L), Na ($3.6{\delta}$/6.87mmol/L), CRE ($9.9{\delta}$/21.8%), BUN ($4.3{\delta}$/13.3%), UA ($5.9{\delta}$/11.5%), T.C ($2.2{\delta}$/10.7%), GLU ($4.8{\delta}$/10.2%), GGT ($7.5{\delta}$/27.3%), CA ($5.5{\delta}$/0.87mmol/L), IP ($8.5{\delta}$/13.17%), TG ($9.6{\delta}$/17.7%). Peer group survey median CV in Korean External Assessment greater than CLIA criteria were CL (8.45%/5%), BUN (13.3%/9%), CRE (21.8%/15%), T.B (25.6%/20%), and Na (6.87mmol/L/4mmol/L). Peer group survey median CV less than it were as TP (9.3%/10%), AST (16.8%/20%), ALT (19.3%/20%), K (0.39mmol/L/0.5mmol/L), UA (11.5%/17%), Ca (0.87mg/dL1mg/L), TG (17.7%/25%). TEa in 17 items were same one in 14 items with 82.35%. We found out the truth on increasing sigma level due to increased total error allowable, and were sure that the goal of setting total error allowable would affect the evaluation of sigma metrics in the process, if sustaining the same process.

• 대한토목학회논문집
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• 제33권5호
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• pp.2081-2091
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• 2013

최근, 엔지니어링의 실무에서 토목 시설물의 설계 및 유지관리 단계를 위한 효과적인 생애주기비용(Life Cycle Cost; LCC) 산정 방법의 실무적인 적용에 대한 요구가 높아지고 있다. 이와 같이, 21세기에 들어 엔지니어링의 최적 의사결정의 실무적 문제에 가치공학과 더불어 생애주기비용 분석은 새로운 패러다임으로 주목받고 있지만 이러한 연구 개발의 괄목할만한 진보에도 불구하고, 대부분의 설계단계 생애주기비용 분석은 확정적, 확률적 분석기법에 그치고 있고 적용 가능한 구조물도 일반 교량에 국한되어 있다. 따라서 본 논문은 설계단계 생애주기비용 분석에 대한 실용적이고 합리적인 신뢰성해석 기반 성능저하 모델을 고려하여 기존의 분석방법을 업데이트하는 분석 방법론을 개발하고 이를 특수교인 사장교에 적용하는데 목적이 있다. 이에 현재가치의 합으로 표현되는 직/간접 유지관리비용을 기존 방법과는 다르게 기대 성능저하모델에 바탕을 둔 최적 유지관리 시나리오를 통한 생애주기비용 분석 기법으로 제시하였다. 마지막으로 본 논문에서 제안한 업데이트된 생애주기비용 분석의 방법론을 실제 고속도로 사장교 건설 프로젝트의 설계단계 의사결정 문제에 적용하여 합리적이고 체계적인 분석 방법 및 최적의사결정과정을 제시하였다.

• 경영정보학연구
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• 제17권2호
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• pp.179-192
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• 2015

학술 분야의 연구자들의 협업을 기반으로 한 공동연구가 활발히 진행되고 있다. 이에 따라 공동연구 및 연구자 간 학문적 관계에 대한 관심 또한 증대되고 있다. 공동연구를 통해 연구자들은 연구 생산성 증대, 비용 및 시간의 효율적 사용, 그리고 연구의 위험요소를 감소시켜 연구 성과와 생산성을 극대화하고 있다. 본 연구는 ISR에 2006년부터 2012년까지 투고된 논문의 저자 및 심사자 데이터를 기반으로 연구 생산성 및 심사 효율성 분석을 실시하였다. 투고된 논문 230편을 대상으로 소셜 네트워크 분석 기법인 중심성 분석과 하위그룹 분석을 실시하였고, 상관분석과 회귀분석을 통해 연구의 타당성을 검토하였다. 연구의 결과는 공저자 집단의 연구 생산성이 향상되는 것을 확인하였으며, ISR의 논문 심사자의 효율성도 소셜 네트워크 분석 지표들을 통해 검증할 수 있었다.

• 한국항공우주학회지
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• 제41권8호
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• pp.619-624
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• 2013

확률론적 수명예측은 파라미터들의 불확실성에 대하여 확률론적인 요소를 적용한다. 따라서 기존의 결정론적 수명해석 기법에 확률론적 기법을 적용하기 위해서는 파손확률을 이용한 위험도 평가가 필요하다. 본 연구에서는 항공기 구조물의 확률론적 위험도평가를 수행하기 위하여 파손확률 추정 모델링 기법을 연구하였다. 이를 위해 파라미터들의 확률론적 불확실성을 효과적으로 반영할 수 있는 베이지안 기법을 이용하여 파손확률을 모델링하고 실험 데이터를 이용하여 검증하였다. 연구결과 베이지안 기반의 파손확률 추정 모델링은 정량적인 파손확률을 계산하고 확률론적 위험도평가를 효과적으로 수행할 수 있음을 입증하였다.

• 한국IT서비스학회지
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• 제19권2호
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• pp.23-35
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• 2020

The development of digital technology is changing the paradigm of the healthcare industry to preventive and consumer-oriented. The combination of the ICT industry and the bio-healthcare industry is emerging as a core industry in the era of the Fourth Industrial Revolution. The Korean government has also selected the bio-healthcare industry as one of the three key future development industries. In May, the government announced its bio-health industry innovation strategy and set a goal of 300,000 employees. Therefore, analyzing the effects of employment on the related industries of the digital bio-healthcare industry is very important for the establishment of future industrial and technology development policies. The research method restructures the integrated classification of 32 industries into 34, including the digital bio-healthcare industry, using the classification criteria of the government and professional institutions, and then reorganizes the digital bio-healthcare industry into eight industries classified as one industry group. The analysis data was taken from the Bank of Korea's 2019 data. Various trigger coefficients and ripple effects coefficients were rewritten using the analysis method of the Input-output Statistics. The analysis of the results compares the employment-induced effects of the digital bio-healthcare industry and the ripple effects of related industries in production, investment and value-added. In addition, in terms of investment effect, the effects of in-house and related industries were compared. It is hoped that the results of this study will be used to establish employment and industrial policies.

• The International Journal of Costume Culture
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• 제12권1호
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• pp.38-51
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• 2009

The goal of this study is to define the types of the lifestyles of senior consumers and identify the differences in the properties of apparel products and the apparel attitudes. To collect the data for this study, questionnaires for the research were distributed from November 20, 2006 to December 15, 2006 to those over 50 living in Seoul, Pusanand Kyunggi and 302 questionnaires were used for the data analysis. The results of the study are as follows. First, six factors were extracted which were "Pursuit of Self-development", "Pursuit of Active Life", "Pursuit of Material", "Pursuit of Diversity", "Pursuit of Family-oriented" and "Pursuit of Recreational Life" after factor analysis of lifestyles recognized by the senior consumers that participated in this study. Second, the lifestyles of the senior consumers were categorized into "Consumption-oriented Type", "Personal Satisfaction-oriented Type", "Family Weighted Type" and "Recreation-oriented Type." Third, three factors were extracted which were "Symbolical Property", "Functional Property" and "Customer Support Property" after conducting the factor analysis on the properties of apparel products. Fourth, significant differences were shown in apparel properties by the lifestyle types of senior consumers in the symbolical property and the customer support property. The "symbolical property" was shown highest in "recreation-oriented type" and lowest in the "family weighted type." The customer support property was shown highest in the "family weighted type" and lowest in the "recreation-oriented type", showing the opposite result. Fifth, significant differences were shown in apparel attitudes by the lifestyle types of senior consumers in "Fashion Innovativeness", "Apparel Involvement" and "Apparel Necessity." The "fashion innovativeness" was shown highest in the "recreation-oriented type" and lowest in the "family weighted type." The apparel involvement and the necessity for apparel for senior citizens was shown high in the "recreation-oriented type" and this showed that the senior consumers valuing recreation also value fashion, have high apparel involvement and feel the necessity for apparel for senior citizens.

• Journal of Korea Trade
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• 제23권6호
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• pp.14-32
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• 2019

Purpose - This study is designed to provide new insights on trade claim management by typifying trade claims from a relational perspective, which defines trade as an organic combination that exchanges relationships based on a mutual goal instead of conflicts between obligations and rights of the contracting parties. Design/methodology - This is a phenomenological study that aims to typify trade claims based on a relational perspective and extract implications for trade claim management. The research procedures of this study are as follows. First, international commercial dispute cases applying the CISG are collected. Second, the cases collected are quantified through content analysis. The variables for quantification are developed based on a relationship perspective. Third, cluster analysis is conducted on coded data to typify cases. And finally, this study compares the characteristics of each type using analysis of variance and suggests implications for the strategic management of trade claims from a relational perspective. Findings - Results show that trade claims are divided into four clusters, depending on whether flexibility is accepted or not and which party violates mutuality. There is also a difference between the claimant and the cause of the claim, according to the cluster. Based on the results, this study suggests that the buyer and the seller should employ different strategies depending on the type of trade claim and presents proposals for strategic claim management. Originality/value - Firstly, this study extends the theoretical discussion on trade claims by applying relational contract theory. Prior studies on trade claims have been primarily based on traditional contract theory. The second is to analyze trade claims quantitatively. Prior case studies on trade claims have mainly relied on qualitative research. Finally, the study contributes to international commercial practice by typifying trade claims and presenting options for strategic management.

• Structural Engineering and Mechanics
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• 제82권1호
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• pp.121-131
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• 2022

The main goal of this study is to prepare a program for analyzing High Strength Steel Fibrous Reinforced Concrete (HSSFRC) slabs and predict the response and strength of the slab instead of preparing a prototype and testing it in the laboratory. For this purpose, new equations are proposed to represent the material properties of High Strength Steel Fibrous Reinforced Concrete. The proposed equations obtained from performing regression analysis on many experimental results using statistical programs. The finite element method is adopted for non-linear analysis of the slabs. The eight-node "Serendipity element" (3 DoF) is chosen to represent the concrete. The layered approach is adopted for concrete elements and the steel reinforcement is represented by a smeared layer. The compression properties of the concrete are modeled by a work hardening plasticity approach and the yield condition is determined depending on the first two stress invariants. A tensile strength criterion is adopted in order to estimate the cracks propagation. many experimental results for testing slabs are compared with the numerical results of the present study and a good agreement is achieved regarding load-deflection curves and crack pattern. The response of the load deflection curve is slightly stiff at the beginning because the creep effect is not considered in this study and for assuming perfect bond between the steel reinforcement and the concrete, however, a great agreement is achieved between the ultimate load from the present study and experimental results. For the models of the tension stiffening and cracked shear modulus, the value of Bg and Bt (Where Bg and Bt are the curvature factor for the cracked shear modulus and tension stiffening models respectively) equal to 0.005 give good results compared with experimental result.

• Communications for Statistical Applications and Methods
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• 제30권2호
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• pp.119-133
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• 2023

With the rapid growth of the economy and fossil fuel consumption, the concentration of air pollutants has increased significantly and the air pollution problem is no longer limited to small areas. We conduct statistical analysis with the actual data related to air quality that covers the entire of South Korea using R and Python. Some factors such as SO₂, CO, O₃, NO₂, PM₁₀, precipitation, wind speed, wind direction, vapor pressure, local pressure, sea level pressure, temperature, humidity, and others are used as covariates. The main goal of this paper is to predict air quality index (AQI) spatio-temporal data. The observations of spatio-temporal big datasets like AQI data are correlated both spatially and temporally, and computation of the prediction or forecasting with dependence structure is often infeasible. As such, the likelihood function based on the spatio-temporal model may be complicated and some special modelings are useful for statistically reliable predictions. In this paper, we propose several methods for this big spatio-temporal AQI data. First, random effects with spatio-temporal basis functions model, a classical statistical analysis, is proposed. Next, neural networks model, a deep learning method based on artificial neural networks, is applied. Finally, random forest model, a machine learning method that is closer to computational science, will be introduced. Then we compare the forecasting performance of each other in terms of predictive diagnostics. As a result of the analysis, all three methods predicted the normal level of PM_2.5 well, but the performance seems to be poor at the extreme value.