• 제목/요약/키워드: Design formula

검색결과 1,306건 처리시간 0.024초

The Process Model of Retail Format Creation in the Japanese Eyeglasses Industry : The Case Study of JINS Inc.

  • Cho, Myung-Rae;Mukoyama, Masao
    • 유통과학연구
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    • 제16권2호
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    • pp.5-18
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    • 2018
  • Purpose - In recent years, new retail innovations have emerged in the Japanese eyeglasses industry and grown as a retail format. The purpose of this study is to establish the process model of retail format creation by examining how a retailer creates a retail format and under what kind of environmental conditions. Research design, data, and methodology - This study pointed out the weakness of the concept of the retail format in existing research on the retail format in existing research on the retail format variation theory and suggested the concept of "Formula" to analyze an individual retailer. This study categorized the subjects categorize the subjects of retail format creation into four categories, and analyzed JINS which is the retail format leader in the Japanese eyeglass industry. This study used secondary data because it is valid. Results - This research found "product handling skill," "changes to consumer purchasing patterns," and "competitive interaction" as environmental factors influencing retail format creation. This study highlighted how JINS adapted those environmental factors to create their original formula and suggested the process model of retail format creation through the JINS case study. Conclusions - This study discussed two theoretical implications and three managerial impressions which were derived from the JINS case study. This study also discussed limitations and further research issues.

Inelastic design of high-axially loaded concrete columns in moderate seismicity regions

  • Ho, Johnny Ching Ming
    • Structural Engineering and Mechanics
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    • 제39권4호
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    • pp.559-578
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    • 2011
  • In regions of high seismic risk, high-strength concrete (HSC) columns of tall buildings are designed to be fully ductile during earthquake attack by providing substantial amount of confining steel within the critical region. However. in areas of low to moderate seismic risk, the same provision of confining steel is too conservative because of the reduced seismic demand. More critically, it causes problematic steel congestion in the beam-column joints and column critical region. This will eventually affect the quality of concrete placing owing to blockage. To relieve the problem, the confining steel in the critical region of HSC columns located in low to moderate seismicity regions can be suitably reduced, while maintaining a limited ductility level. Despite the advantage, there are still no guidelines developed for designing limited ductility HSC columns. In this paper, a formula for designing limited ductility HSC columns is presented. The validity of the formula was verified by testing half-scale HSC columns subjected to combined high-axial load and flexure, in which the confining steel was provided as per the proposed formula. From the test results, it is evident that the curvature ductility factors obtained for all these columns were about 10, which is the generally accepted level of limited ductility.

등단면 3경간 연속 곡선격자형교의 휨모멘트 근사해석에 관한 연구 (A Study on the Approximate Analysis of the Bending Moment for the Three-Span Continuous Curved Girder Bridges with Constant Cross Section)

  • 장병순;서상근;차기혁
    • 한국강구조학회 논문집
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    • 제11권2호통권39호
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    • pp.131-142
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    • 1999
  • 뒤틀림 효과를 고려한 곡선보의 일반적 거동은 Vlasov에 의해 제시된 미분 방정식으로 표시된다. 일반적으로 거더의 단면을 결정하는데 가장 큰 영향을 미치는 요인은 휨모멘트이다. 곡선 교량 계획시 곡선격자형교의 단면을 쉽게 가정하기 위해서 본 논문에서는 직선거더와 곡선거더의 휨모멘트비를 제시하였다. 이 비는 중심각 ${\theta}(L/R)$를 변수로 하여 근사식으로 나타내었다. 이 휨모멘트 근사식과 제시된 영향선은 3경간 곡선격자형교를 보다 쉽게 설계하는데 이용될 수 있다.

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지반 조건을 고려한 최적강관두께의 결정 (The Determination of Optimal Steel Pipe Wall Thickness Considering Ground Condition)

  • 박재성;오병동;이호진
    • 한국지반환경공학회 논문집
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    • 제9권3호
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    • pp.11-15
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    • 2008
  • 대구경 상수도 관로는 제작 및 경제성 요인에 의해 주로 강관을 사용해 오고 있다. 상수도시설기준(건교부, 1992)에 강관두께를 결정하는 기준을 제시하고 있다. 그러나, 이 기준에는 강관 두께를 결정하는 체계적인 기준이 없다. 그래서, 매설관로에는 적용이 부적합한 Stewart 공식을 적용하여 강관두께를 결정해 왔다. 개정된 상수도시설기준(환경부, 1997) 에 부합되도록 지반여건과 각종응력을 고려하여 강관두께를 산정하였다. 그 결과를 기존의 방법에 의해 산정된 결과와 비교 검토한 후 최적 강관두께를 결정하는 방법을 제시하였다.

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유한장 직선도체에 의한 자계의 계산 및 감소대책 (Calculation and Mitigation of Magnetic Field Produced by Straight Line-Conductor with Finite Length)

  • 강대하
    • 조명전기설비학회논문지
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    • 제25권6호
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    • pp.57-67
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    • 2011
  • Purpose of this study is to find the mitigation method of magnetic field by finite length multi-conductors such as indoor distribution lines and to be applicable to design of the distribution lines. For this purpose, exact formula about the components $B_x$, $B_y$, $B_z$ of magnetic field need in case of straight line-conductor with finite length forward any direction. In this study simple formula of the components were deduced and by using these formula magnetic fields for various models of line-configurations were calculated. And also a calculation method of induced currents in conductive shield was presented and using this method, programing of calculation is relatively easy and calculation time is short. The magnetic field after cancellation by these induced currents was calculated. All of calculations were performed by Matlab 7.0 programs. Through the calculation results it could be obtained followings for the mitigation of magnetic fields. The separation between conductors ought to be smaller than smaller as possible. In case of 3-phase, delta configuration is more effective than flat configuration. In case of 3-phase, unbalanced currents ought to be reduced as possible.. In case of more than two circuits of 3-phase, adequate locations of each phase-conductor such as rotating configuration of 3-phase conductors are more effective. The magnetic shielding effect of the conductive shielding sheet is very high.

MathML 수식 구조 표현을 지향하는 XML 문서 편집 시스템의 설계 및 구현 (Design and implementation of XML document edit system that intend to MathML mathematical formula structure representation)

  • 김철순;정회경
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2002년도 추계종합학술대회
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    • pp.363-367
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    • 2002
  • 컴퓨터를 이용한 전자문서처리에 이용되는 기존의 문서편집 시스템에서는 비구조적인 문서구조를 다루게 됨으로써 시스템 내에서 사용되는 수학식의 표현은 이미지나 텍스트 등의 비구조적인 방법에 의해 표현되거나 처리된다. 이렇게 사용된 수학식은 문서의 가독성과 재사용성 그리고 문서의 처리와 교환에 상대적인 불편을 초래하게 된다. 그러므로 이러한 단점을 극복하고 효율적으로 구조적인 문서상에 MathML(Mathematical Markup Language) 수식 구조를 적용시킬 수 있는 문서편집 시스템이 요구된다. 이에 본 논문에서는 MathML을 기반으로 한 수학식의 표현을 구조적으로 처리할 수 있는 MathML 수식 편집이 가능한 XML(eXtensible Markup Language) 기반의 구조적 문서생성을 위한 문서 편집 시스템을 설계 및 구현하였다.

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Prediction of bridge flutter under a crosswind flow

  • Vu, Tan-Van;Lee, Ho-Yeop;Choi, Byung-Ho;Lee, Hak-Eun
    • Wind and Structures
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    • 제17권3호
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    • pp.275-298
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    • 2013
  • This paper presents a number of approximated analytical formulations for the flutter analysis of long-span bridges using the so-called uncoupled flutter derivatives. The formulae have been developed from the simplified framework of a bimodal coupled flutter problem. As a result, the proposed method represents an extension of Selberg's empirical formula to generic bridge sections, which may be prone to one of the aeroelastic instability such as coupled-mode or single-mode (either dominated by torsion or heaving mode) flutter. Two approximated expressions for the flutter derivatives are required so that only the experimental flutter derivatives of ($H_1^*$, $A_2^*$) are measured to calculate the onset flutter. Based on asymptotic expansions of the flutter derivatives, a further simplified formula was derived to predict the critical wind speed of the cross section, which is prone to the coupled-mode flutter at large reduced wind speeds. The numerical results produced by the proposed formulas have been compared with results obtained by complex eigenvalue analysis and available approximated methods show that they seem to give satisfactory results for a wide range of study cases. Thus, these formulas can be used in the assessment of bridge flutter performance at the preliminary design stage.

Mechanical behaviors of concrete-filled rectangular steel tubular under pure torsion

  • Ding, Fa-xing;Sheng, Shi-jing;Yu, Yu-jie;Yu, Zhi-wu
    • Steel and Composite Structures
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    • 제31권3호
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    • pp.291-301
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    • 2019
  • Pure torsion loading conditions were not frequently occurred in practical engineering, but the torsional researches were important since it's the basis of mechanical property researches under complex loading. Then a 3D finite element model with precise material constitutive models was established, and the effectiveness was verified with test data. Parametric studies with varying factors as steel yield strength, concrete strength and sectional height-width ratio, were performed. Internal stress state and the interaction effect between encased steel tube and the core concrete were analyzed. Results indicated that due to the confinement effect between steel tube and core concrete, the torsional strength of CFT columns was greatly improved comparing to plain concrete columns. The steel ratio would greatly influence the torque share between the steel tube and the core concrete. Then the torsional strength calculation formulas for core concrete and the whole CFT column were proposed. The proposed formula could be simpler and easier to use with guaranteed accuracy. Related design codes were more conservative than the proposed formula, but the proposed formula presented more satisfactory agreement with experimental results.

유조선 좌초 사고 시 2차사고 방지를 위한 잔류강도 평가기술 개발 (Development of an Empirical Formula for Residual Strength Assessment to Prevent Sequential Events of Grounded Oil Tankers)

  • 백승준;김상진;백점기;손정민
    • 대한조선학회논문집
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    • 제56권3호
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    • pp.263-272
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    • 2019
  • The aim of this study is to develop a rapid calculation technique of the residual strength in order to prevent sequential events under grounding accidents. Very Large Crude-Oil Carrier (VLCC), Suezmax, and Aframax double hull oil tankers carrying large quantities of crude oil were selected for target structures. The rock geometries are chosen from the published regulation by Marine Pollution Treaty (MARPOL) of the International Maritime Organization (IMO). Oceanic rocks as the most frequently encountered obstruction with ships are applied in this work. Damage condition was predicted using ALPS/HULL program based on grounding scenario with selected parameters, i.e. depth of penetration, damage location and tanker type. The results of the scenarios are quantified to form an empirical formula which can evaluate the residual strength. The proposed formula is validated by applying a series of random grounding scenarios.

Research on axial bearing capacity of cold-formed thin-walled steel built-up column with 12-limb-section

  • Wentao Qiao;Yuhuan Wang;Ruifeng Li;Dong Wang;Haiying Zhang
    • Steel and Composite Structures
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    • 제47권3호
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    • pp.437-450
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    • 2023
  • A half open cross section built-up column, namely cold-formed thin-walled steel built-up column with 12-limbsection (CTSBC-12) is put forward. To deeply reveal the mechanical behaviors of CTSBC-12 under axial compression and put forward its calculation formula of axial bearing capacity, based on the previous axial compression experimental research, the finite element analysis (FEA) is conducted on 9 CTSBC-12 specimens, and then the variable parameter analysis is carried out. The results show the FEA is in good agreement with the experimental research, the ultimate bearing capacity error is within 10%. When the slenderness ratio is more than 96.54, the ultimate bearing capacity of CTSBC-12 decreases rapidly, and the failure mode changes from local buckling to global buckling. With the local buckling failure mode unchanged, the ultimate bearing capacity decreases gradually as the ratio of web height to thickness increases. Three methods are used for calculating the ultimate bearing capacity, the direct strength method of AISI S100-2007 gives result of ultimate axial load which is closest to the test and FEA results. But for simplicity and practicality, a simplified axial bearing capacity formula is proposed, which has better calculation accuracy with the slenderness ratio changing from 30 to 100.