• 월간경쟁저널
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• 10호
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• pp.77-81
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• 1997

• 한국해양공학회지
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• 제32권6호
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• pp.433-439
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• 2018

An investigation was conducted to determine whether the changes in the maneuvering forces and moments acting on a hull could be affected by changing the vertical center of gravity (VCG) of a tanker. The changes in the hydrodynamic forces and moment acting on a hull according to the restraint conditions of motion were examined using CFD for cases where the VCG was located at the design draught (100% of draught), under the design draught (75% of draught), and at half of the design draught (50% of draught). The following motion restraint conditions were selected: (1) fixed restraints for everything; (2) heave, pitch, and roll free restraint; and (3) heave and pitch free restraints. It was found that restraint condition (2) had the best agreement with the model experiment results. In addition, it was found that the hydrodynamic forces and moment acting on the hull with restraint condition (2) could be greatly affected in the model tests and CFD calculations by the various configurations for the vertical center of gravity of the hull. Finally, it was concluded that the location of the vertical center of gravity of the hull could be an important factor when more accurate hydrodynamic maneuvering forces and moment are estimated.

• 대한안전경영과학회지
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• 제26권1호
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• pp.9-14
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• 2024

Restraints of Branch Lines are used as earthquake-resistant support devices for fire-fighting pipes along with sway brace devices. The central types are aligned and fixed in a straight line with center of the pipe, but the eccentric types are fixed to on side of the pipe, so a bending moment occurs. In this study, three specimens each of central type and eccentric type were installed at an angle of 45° from the vertical and a monotonic compression load of 1340N was applied. All central type samples satisfied 17.8mm of the allowable displacement, but all eccentric type samples failed to meet the target load and buckled. Therefore, when considering the performance of eccentric type restraints, both compressive load and bending moment must be considered. Even through material mechanics calculations, the yield stress of eccentric type - 3/8 inch all threaded steel bolt - exceeds 320Mpa of the allowable stress. A experiment standards need to be established for eccentric type restraints.

• 월간경쟁저널
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• 127호
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• pp.6-19
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• 2006

사적 경쟁제한행위에 대한 효과적인 규제 없는 통상협정은 그 소기의 목적을 달성하기 힘들다. 통상협정은 근본적으로는 협정 당사국에 대한 시장접근(market access)을 높이기 위한 것이다. 그런데 협정을 통하여 공적 장벽을 없앤다고 하더라도 해당국가에 예컨대 고질적인 수직적 거래제한(vertical restraints)이 만연해 있어서 외국기업이 자국의 소비자에게 접근할 수 없다면 통상협정을 통하여 달성하고자 하는 시장접근은 공염불이 될 것이다. 한미 FTA협상에도 통상협정과 경쟁정책과의 이러한 상호보완적인 관계에 대한 깊이 있는 성찰이 있어야 할 것이다.

• 한국프랜차이즈경영연구
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• 제11권1호
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• pp.45-60
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• 2020

Propose: The expansion of the delivery market in franchise business is a positive means of advertising and promotion for franchisees and contributes to substantial sales growth for stores. However, unrestricted and uncontrolled delivery sales and business activity of franchisee directly lead to encroachment of business territory between franchisees, resulting in increased operating costs of franchisees and conflicts between franchisees over rights and interests on franchise business. Moreover, in relation to the restrictions on the opening of competitors, it is incapacitating the law intent of prohibiting unfair encroachment of business territory, in the issue of the Fair Franchise Act in regard to guarantee of exclusive sales and business activity rights of franchisee. This study aims to point out major problems arising out of franchisee's infinite competition on delivery sales and business activity that are not restricted or controlled and then suggest legal supplements, policy tasks, and practical implications for improvement on the issues. Literature Review: In franchising business transactions, vertical restraints are associated with the exclusive territory establishment, control of transaction area, restriction of intangible sales and business activity of franchisee. Therefore, in the franchise business, it is necessary to take positive interpretation and application on e-commerce, the area of e-commerce, and delivery trading area and find proper and practical ways, by virtue of constructive attitude of each actor, to reduce the encroachment of business territory and various conflicts caused by unrestricted delivery trading area. Conclusion and suggestion: The finding shows that unrestricted or uncontrolled delivery sales and business activity of franchisees cause encroachment of business territory and many conflicts among franchisees. And this matters also weaken the legislation of the law on the protection of the business territory and can be negative factors that disrupt the protection of identity and sound development of the franchise industry in the long run. Therefore, in the franchise business, it is necessary to take positive interpretation and application on e-commerce, the area of e-commerce, and delivery trading area and find proper and practical ways, by virtue of constructive attitude of each actor, to reduce the encroachment of business territory and various conflicts caused by unrestricted delivery trading area.

• 한국도로학회논문집
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• 제11권3호
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• pp.151-161
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• 2009

본 연구는 장스팬 콘크리트 포장 슬래브가 환경하중을 받아 컬링 거동을 할 때의 특성을 분석하기 위하여 수행되었다. 먼저 장스팬 포장 슬래브의 유한요소해석 모델을 구성하여 컬링 시 응력분포 특성 및 슬래브 길이, 두께, 하부지지층 강성, 슬래브 단부 구속 등이 컬링 거동에 미치는 영향을 분석하였다. 또한 실제 시공된 장스팬 포장 슬래브를 이용하여 현장에서 환경하중에 의한 거동을 측정함으로써 컬링 거동 특성을 실험적으로도 분석하였다. 연구 결과, 장스팬 포장 슬래브는 단부에서 부터 슬래브 중앙을 따라 어느 정도 안쪽으로 들어오면 컬링에 의한 수직변위가 발생하지 않으며 응력은 이곳에서부터 일정하게 최대치를 보이게 된다. 장스팬 포장 슬래브의 길이 및 하부지지층의 강성은 최대 컬링 응력에 영향을 미치지 않았으며, 슬래브 단부의 구속은 컬링 응력이 단부까지 발생하게 하지만 최대 컬링 응력의 크기에는 거의 영향을 미치지 않았다.

• Steel and Composite Structures
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• 제49권2호
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• pp.143-159
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• 2023

Recently, the design of scaffolding systems has garnered considerable attention due to the increasing number of scaffold collapses. These incidents arise from the underestimation of imposed loads and the site-specific conditions that restrict the application of lateral restraints in scaffold assemblies. The present study is committed to augmenting the buckling resistance of vertical support members, obviating the need for supplementary lateral restraints. To achieve this objective, experimental and computational analyses were performed to assess the axial load buckling capacity of steel props, composed of two hollow steel pipes that slide into each other for a certain length. Three full-scale steel props with various geometric properties were tested to construct and validate the analytical models. The total unsupported length of the steel props is 6 m, while three pins were installed to tighten the outer and inner pipes in the distance they overlapped. Finite Element (FE) modeling is carried out for the three steel props, and the developed models were verified using the experimental results. Also, theoretical analysis is utilized to verify the FE analysis. Using the FE-verified models, a parametric study is conducted to evaluate the effect of different inserted pipe lengths on the steel props' axial load capacity and lateral displacement. Based on the results, the typical failure mode for the studied steel props is global elastic buckling. Also, the prop's elastic buckling strength is sensitive to the inserted length of the smaller pipe. A threshold of minimum inserted length is one-third of the total length, after which the buckling strength increases. The present study offers a prop with enhanced buckling resistance and introduces an equation for calculating an equivalent effective length factor (k), which can be seamlessly incorporated into Euler's buckling equation, thereby facilitating the determination of the buckling capacity of the enhanced props and providing a pragmatic engineering solution.

• International Journal of Naval Architecture and Ocean Engineering
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• 제7권5호
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• pp.805-816
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• 2015

In the present study, external restraints imposed normal to the plate during the cooling stage were determined to be effective for reduction of the angular distortion of butt-welded or fillet-welded plate. A welding analysis model under external force during the cooling stage was idealized as a prismatic member subjected to pure bending. The external restraint was represented by vertical force on both sides of the work piece and bending stress forms in the transverse direction. The additional bending stress distribution across the plate thickness was reflected in the improved inherent strain model, and a set of inherent strain charts with different levels of bending stress were newly calculated. From an elastic linear FE analysis using the inherent strain values taken from the chart and comparing them with those from a 3D thermal elasto-plastic FE analysis, welding deformation can be calculated.

• 대한공간정보학회지
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• 제5권1호
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• pp.57-70
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• 1997

전례적인 천문측량방법으로 연직선편차나 천문좌표를 결정하기 위해서는 별을 관측해야 하며 기상조건, 주변환경, 관측시간 및 측정기기 취급의 어려움 등 많은 제약조건이 수반되므로 좀더 효율적인 측정방법이 요구되고 있다. 본 연구에서는 WGS84좌표와 정표고를 이용하여 연직선 편차, 천문경도, 천문위도 및 천문방위각을 산정할 수 있는 프로그램을 구성하고 국내에 있는 10개의 천문점과 인접한 측점들에 대한 GPS 관측으로부터 천문성과를 산출하고 전통적인 천문측량방식 및 최신의 지구중력장모델(EGM96)에 의한 결과와도 비교 검토하므로서 GPS에 의한 연직선편차와 천문좌표의 산정법을 제시한 것이다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1991년도 가을 학술발표회 논문집
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• pp.111-114
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• 1991

The KMRR 4-wheel crane which has a span of 30.6m long shall be designed to maintain its structural integrity during and after seismic shocks. Horizontal and vertical FRS for OBE and SSE conditions at the crane support are after seismic shock. Horizontal and vertical FRS for analysis are 4% for OBE and 7% for SSE. The crane consists of girder, saddle main and auxiliary trolley, and necessaries. They are modeled as beam elements and lumped masses for the following 4 cases ; trolley at center of the crane with and without the rated load, trolley at end with and without the rated load. The static analysis as well as the linear dynamic analysis including frequency and response spectrum analysis are performed for the seismic qualification of the crane using the Finite Element Method. For the simplicity of the analysis, the decoupling criteria are considered for the crane rope and the crane supporting beams. The main sections of the crane are stiffened until the calculated stresses satisfy the allowable limits. The seismic resultant loads are used to design the seismic restraints of the saddle and the trolley to protect the clue from the seismic uplifting loads the study results have show that the seismic design of the KMRR crane is governed by the OBE condition. not by the SSE condition. This paper briefly describes the analysis procedure used in the seismic design of the KMRR crane, and summarizes the analysis results.