• 대한기계학회논문집B
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• 제25권11호
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• pp.1459-1466
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• 2001

A slip factor is defined as an empirical factor, which should be multiplied to theoretical energy transfer to estimate real work input of a centrifugal compressor. During the last century, researchers have tried to develop simple empirical models to predict the slip factor. However most of these models have been developed based only on design point data. Furthermore flow is assumed inviscid. As a result, these models often fail to predict the correct slip factor at off-design condition. In this study, various models for the slip factor were analysed and compared with experimental and numerical data at off-design conditions. As a result of this study, Wiesner's and Paeng and Chung's models are shown to be applicable for radial impeller, but all the models are found to be inappropriate for backswept impellers.

• Steel and Composite Structures
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• 제11권4호
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• pp.273-290
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• 2011

In current ductility-based earthquake-resistant design, the estimation of design forces continues to be carried out with the application of response modification factors on elastic design spectra. It is well-known that the response modification factor (R) takes into account the force reduction, strength, redundancy, and damping of structural systems. The key components of the response modification factor (R) are force reduction ($R_{\mu}$) and strength ($R_S$) factors. However, the response modification and strength factors for structural systems presented in design codes were based on professional judgment and experiences. A numerical study has been accomplished to evaluate force reduction, strength, and response modification factors for special steel moment resisting frames. A total of 72 prototype steel frames were designed based on the recommendations given in the AISC Seismic Provisions and UBC Codes. Number of stories, soil profiles, seismic zone factors, framing systems, and failure mechanisms were considered as the design parameters that influence the response. The effects of the design parameters on force reduction ($R_{\mu}$), strength ($R_S$), and response modification (R) factors were studied. Based on the analysis results, these factors for special steel moment resisting frames are evaluated.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.433-436
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• 2007

We analyzed the sloped ground safety factor, which is not presented in the design specification, using a computational analysis program L-Pile Plus 13.8. To achieve this we chose a required parameter set and a level ground safety factor presented in the design specification, and then determined its values comparing with the change of the safety factor according to the parameter. Using these parameters, we estimated the sloped ground safety factor for the slope of 35 degrees considering the improvement value of the slope presented in the design specification. As a result of this analysis, we obtained the smaller safety factor by about 0.7 times than the case of the level ground and verified that a number of concrete poles fail to assure 1 degree of the safety factor. We, therefore, concluded that an adjustment of the embedment depth is required in the case of the sloped ground.

• 디지털융복합연구
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• 제17권12호
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• pp.117-127
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• 2019

본 연구의 목적은 중국 소비자의 휴대폰 선택 시 고려하는 주요 평가영역에 대한 세부 특성요인의 만족도가 해당 평가영역 만족도에 어떠한 영향을 미치며, 각 평가영역에 대한 만족도가 고객의 재구매의도와 타인추천의도에 어떠한 영향을 미치는가를 사용 휴대폰 유형에 따른 집단별로 분석하는데 있다. 설문조사 시 평가요인으로 가격, 디자인, 품질, 편리성, 기능 그리고 개인적 요인을 설정하였으며, 재구매의도와 타인추천의도로 구분 실시하였다. 연구결과, 가격을 제외한 모든 특성요인이 해당 평가영역의 만족에 유의한 것으로 나타났으며 유의한 경로가 집단별로 차이가 존재함을 알 수 있었다. 또한 모든 집단에서 평가영역에 대한 만족이 재구매의도와 타인추천의도에 유의한 것으로 평가되었다. 연구 결과 우리 기업의 경우 디자인, 기능, 개인적 요인에 관한 특성요인은 평가영역 만족에 유의한 영향을 미치나 해당 특성요인의 만족도는 상대적으로 낮은 것으로 나타난다. 따라서 이들 특성요인에 대한 만족도를 높일 수 있는 품질 개선방안을 강구하여야 할 것으로 사료된다.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2011년도 춘계학술대회
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• pp.695-699
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• 2011

The study presents an efficient design method of Venn Diagram that can be used when implementing the quality design of experiments based on generalizability theory. The paper examines four mixed and combined models that are designed by fixed factor, random factor, crossed factor and nested factor. The models considered in this research are $A^*{\times}B^*{\times}C$, (B: $A^*$)${\times}C$, $A{\times}B{\times}C$ and (B: A)${\times}C$.

• Earthquakes and Structures
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• 제20권2호
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• pp.133-148
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• 2021

The paper presents a simplified force-based seismic design procedure for the preliminary design of steel haunch retrofitting for the seismic upgrade of deficient RC frames. The procedure involved constructing a site-specific seismic design spectrum for the site, which is transformed into seismic base shear coefficient demand, using an applicable response modification factor, that defines base shear force for seismic analysis of the structure. Recent experimental campaign; involving shake table testing of ten (10), and quasi-static cyclic testing of two (02), 1:3 reduced scale RC frame models, carried out for the seismic performance assessment of both deficient and retrofitted structures has provided the basis to calculate retrofit-specific response modification factor Rretrofitted. The haunch retrofitting technique enhanced the structural stiffness, strength, and ductility, hence, increased the structural response modification factor, which is mainly dependent on the applied retrofit scheme. An additional retrofit effectiveness factor (ΩR) is proposed for the deficient structure's response modification factor Rdeficient, representing the retrofit effectiveness (ΩR=Rretrofitted /Rdeficient), to calculate components' moment and shear demands for the retrofitted structure. The experimental campaign revealed that regardless of the deficient structures' characteristics, the ΩR factor remains fairly the unchanged, which is encouraging to generalize the design procedure. Haunch configuration is finalized that avoid brittle hinging of beam-column joints and ensure ductile beam yielding. Example case study for the seismic retrofit designs of RC frames are presented, which were validated through equivalent lateral load analysis using elastic model and response history analysis of finite-element based inelastic model, showing reasonable performance of the proposed design procedure. The proposed design has the advantage to provide a seismic zone-specific design solution, and also, to suggest if any additional measure is required to enhance the strength/deformability of beams and columns.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1631-1635
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• 2011

To consider dynamic magnification effect at the static design stage, impact load factor is applied to design load. Current impact load factor adopted EUROCODE without verification while Japan suggested impact load factor including velocity of high-speed train throughout theoretical and experimental studies. On the purpose of evaluate current impact load factor, this study investigated the calculation of impact load factor from dynamic response of running train.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2009년도 춘계학술대회
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• pp.177-183
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• 2009

The research develops random ordering methodology of experimental design by the use of nested factor, block factor and repetition types. The spreadsheets developed are useful for quality practioner to acquire the experimental characteristics according to the random ordering.

• 한국디자인학회:학술대회논문집
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• 한국디자인학회 2001년도 Bulletin of The 5th Asian Design Conference International Symposium on Design Science
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• pp.64.1-64
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• 2001

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2004년도 춘계학술대회
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• pp.131-139
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• 2004

Robust parameter design is to identify appropriate settings of control factors that make the system's performance robust to changes in the noise factors that represent the source of variation. In this paper, we introduce a factor analysis approach to simultaneously optimize multiple quality characteristics in the robust parameter design. An example is illustrated to compare it with already proposed method.