• 제목/요약/키워드: design provisions

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철근 정착길이를 고려한 개구부가 있는 철근콘크리트 전단벽의 유한요소해석 (Nonlinear Finite Element Analysis for RC Shear Wall with an Opening Considering Rebar Development Length)

  • 최윤범;이성철
    • 한국전산구조공학회논문집
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    • 제29권6호
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    • pp.547-554
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    • 2016
  • 본 논문에서는 개구부가 있는 철근콘크리트 전단벽의 전단강도를 산정하기 위해 수정압축장 이론에 기반을 둔 비선형 유한요소해석을 수행하였다. 철근콘크리트 전단벽의 전단강도에서 개구부의 영향을 분석하기 위해 개구부 주변 정착길이 내 철근들에 대한 철근비를 해석 모델에서 감소시켰으며, 비선형 유한요소해석은 기존 문헌에 제시된 시험 결과와의 비교를 통해 검증되었다. 실험 결과와의 비교를 통해 개구부 주변 철근들의 정착길이를 고려한 비선형 유한요소해석의 경우 철근콘크리트 전단벽의 전단강도 예측에 있어 개구부의 영향을 잘 반영한 것으로 나타났다. 이에 반해, 현행 설계기준들은 전단강도를 합리적으로 예측하지 못하는 것으로 나타났다. 본 논문은 향후 기존 철근콘크리트 전단벽에 개구부를 설치하는 경우, 전단벽의 합리적인 전단강도 예측에 유용할 것으로 기대된다.

Open-jet boundary-layer processes for aerodynamic testing of low-rise buildings

  • Gol-Zaroudi, Hamzeh;Aly, Aly-Mousaad
    • Wind and Structures
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    • 제25권3호
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    • pp.233-259
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    • 2017
  • Investigations on simulated near-surface atmospheric boundary layer (ABL) in an open-jet facility are carried out by conducting experimental tests on small-scale models of low-rise buildings. The objectives of the current study are: (1) to determine the optimal location of test buildings from the exit of the open-jet facility, and (2) to investigate the scale effect on the aerodynamic pressure characteristics. Based on the results, the newly built open-jet facility is well capable of producing mean wind speed and turbulence profiles representing open-terrain conditions. The results show that the proximity of the test model to the open-jet governs the length of the separation bubble as well as the peak roof pressures. However, test models placed at a horizontal distance of 2.5H (H is height of the wind field) from the exit of the open-jet, with a width that is half the width of the wind field and a length of 1H, have consistent mean and peak pressure coefficients when compared with available results from wind tunnel testing. In addition, testing models with as large as 16% blockage ratio is feasible within the open-jet facility. This reveals the importance of open-jet facilities as a robust tool to alleviate the scale restrictions involved in physical investigations of flow pattern around civil engineering structures. The results and findings of this study are useful for putting forward recommendations and guidelines for testing protocols at open-jet facilities, eventually helping the progress of enhanced standard provisions on the design of low-rise buildings for wind.

쾌속조형기술의 구현을 위한 3차원 제어시스템 개발 (Development of a Three Dimensional Control System for Implementing Rapid Prototyping Technology)

  • 조성목
    • 한국산학기술학회논문지
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    • 제8권4호
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    • pp.775-780
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    • 2007
  • 쾌속조형기술(Rapid Prototyping Technology)은 설계단계에 있는 3차원 모델을 시제품(Prototype)으로 다른 중간과정 없이 빠르게 생성하는 새로운 기술을 말한다. CAD 모델 데이터는 3차원 형상 시스템이지만 모니터 화면이나 문서로 출력할 때는 2차원으로 밖에 표시되지 않는다. 반면에 쾌속조형기술은 설계된 3차원 CAD 데이터를 2차원 단면 데이터로 변환한 후 RP(Rapid Prototyping)공정을 적용하여 순차적으로 적층해 감으로써 CAD 데이터와 같은 3차원 입체 형상을 제작하게 된다. 그러나 RP 시스템은 매우 가격이 비싸서 칫솔이나 완구 등과 같은 생활용품을 제작하는 중소기업에서는 구입하기 어려운 상황이다. 본 논문에서는 오픈소스를 사용하여 RP 기술을 구현함으로써 저렴한 가격으로 구매할 수 있는 RP 시스템을 개발하기 위한 3차원 제어시스템을 제안하였다.

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탄소섬유쉬트로 보강한 고강도 콘크리트 충전강관(CFT) 기둥의 휨내력에 관한 연구 (Flexural strength of high-strength concrete filled steel tube columns strengthened by carbon fiber sheets)

  • 박재우;홍영균;홍기섭
    • 한국지진공학회논문집
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    • 제12권1호
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    • pp.21-28
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    • 2008
  • CFT(Concrete Filled Steel Tube)기둥은 부재의 합성효과와 경제적인 측면 때문에 최근 고층건물 시공 시 널리 쓰이고 있다. 그러나 기존의 연구문헌을 살펴보면 CFT 기둥은 강관의 항복이후 강관의 일정지점에 국부좌굴이 생기는 단점을 지니고 있다. 이러한 문제점을 해결하기 위하여 예상 국부좌굴부위를 탄소섬유쉬트로 보강하여 국부좌굴을 방지하거나 지연시키는 TR-CFT (Transversely Reinforced Concrete Filled Steel Tube) 기둥에 관한 연구가 진행되고 있다. 본 연구에서는 고강도 콘크리트를 사용한 TR-CFT기둥의 실험을 수행하였으며 휨내력에 대한 해석을 수행한 결과 실험값과 해석값이 잘 일치하였다. 또한 기존의 ACI 318 설계법은 강관내부에서 발생하는 콘크리트에 대한 구속효과를 고려하지 않아 저평가가 되어있음을 알 수 있었다.

Role of Headmasters, Teachers, and Supervisors in Knowledge Transfer about Occupational Health and Safety to Pupils in Vocational Education

  • Andersson, Ing-Marie;Gunnarsson, Kristina;Rosen, Gunnar
    • Safety and Health at Work
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    • 제6권4호
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    • pp.317-323
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    • 2015
  • Background: Young people are at an increased risk for illness in working life. The authorities stipulate certain goals for training in occupational health and safety (OHS) in vocational schools. A previous study concluded that pupils in vocational education had limited knowledge in the prevention of health risks at work. The aim of the current study, therefore, was to study how OHS training is organized in school and in workplace-based learning (WPL). Methods: The study design featured a qualitative approach, which included interviews with 12 headmasters, 20 teachers, and 20 supervisors at companies in which the pupils had their WPL. The study was conducted at 10 upper secondary schools, located in Central Sweden, that were graduating pupils in four vocational programs. Results: The interviews with headmasters, teachers, and supervisors indicate a staggered picture of how pupils are prepared for safe work. The headmasters generally give teachers the responsibility for how goals should be reached. Teaching is very much based on risk factors that are present in the workshops and on teachers' own experiences and knowledge. The teaching during WPL also lacks the systematic training in OHS as well as in the traditional classroom environment. Conclusion: Teachers and supervisors did not plan the training in OHS in accordance with the provisions of systematic work environment management. Instead, the teachers based the training on their own experiences. Most of the supervisors did not receive information from the schools as to what should be included when introducing OHS issues in WPL.

POWER UPRATES IN NUCLEAR POWER PLANTS: INTERNATIONAL EXPERIENCES AND APPROACHES FOR IMPLEMENTATION

  • Kang, Ki-Sig
    • Nuclear Engineering and Technology
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    • 제40권4호
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    • pp.255-268
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    • 2008
  • The greater demand for electricity and the available capacity within safety margins in some operating NPPs are prompting nuclear utilities to request license modification to enable operation at a higher power level, beyond their original license provisions. Such plant modifications require an in-depth safety analysis to evaluate the possible safety impact. The analysis must consider the thermo hydraulic, radiological and structural aspects, and the plant behavior, while taking into account the capability of the structures, systems and components, and the reactor protection and safeguard systems set points. The purpose of this paper is to introduce international experiences and approaches for implementation of power uprates related to the reactor thermal power of nuclear power plants. The paper is intended to give the reader a general overview of the major processes, work products, issues, challenges, events, and experiences in the power uprates program. The process of increasing the licensed power level of a nuclear power plants is called a power uprate. One way of increasing the thermal output from a reactor is to increase the amount of fissile material in use. It is also possible to increase the core power by increasing the performance of the high power bundles. Safety margins can be maintained by either using fuels with a higher performance, or through the use of improved methods of analysis to demonstrate that the required margins are retained even at the higher power levels. The paper will review all types of power uprates, from small to large, and across various reactor types, including light and heavy water, pressurized, and boiling water reactors. Generally, however, the content of the report focuses on power uprates of the stretch and extended type. The International Atomic Energy Agency (IAEA) is developing a technical guideline on power uprates and side effects of power uprates in nuclear power plants.

문재인정부의 보건의료정책 평가와 차기 정부의 과제 (Moon Jae-in Government Health Policy Evaluation and Next Government Tasks)

  • 최병호
    • 보건행정학회지
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    • 제31권4호
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    • pp.387-398
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    • 2021
  • Moon Jae-in Care can be seen as a 2.0 version of Roh Moo-Hyun Care. Just as Roh Care failed to achieve its coverage rate goal and 30% share of public beds, Moon Care also failed to achieve its expected goal. The reason is that it followed Roh Care's failed strategy. Failure to control non-covered services has led to a long way to achieve a 70% coverage rate and induced the expansion of voluntary indemnity insurance, resulting in increased public burden. The universal coverage of non-covered services caused an immediate backlash from doctors. And Moon government also failed to control the private insurance market. The expansion of publicly owned beds has not become realized and has not obtained public support. Above all, it failed to overcome the resistance of doctors and failed to obtain consent from budget power groups in the cabinet for public investment. It was also insufficient to win the support of civic groups. Communication with interested groups failed and the role of private health care providers was neglected. The next government should also continue to strengthen health care coverage, but it should prioritize preventing medical poor and create a consensus with both medical providers and consumers for the control of non-covered services. Ahead of the super-aged society, the establishment of linkage between medical services and long-term care and visiting health care or welfare services is an important task. All public and private provisions and resources should be utilized in the view of a comprehensive public health perspective, and public investment should be input in sectors where public medical institutions can perform more effective functions. The next government, which will be launched in 2022, should design a new paradigm for health care in the face of a period of transformation, such as the coming super-aged society in 2026 and the Fourth Industrial Revolution, and recognize that the capabilities of the health care system represent the nation's overall capacity.

Issues on Particular Market Situation to Calculate Dumping Margin of Korean Steel Products by the USA

  • Wang, Jingjing;Choi, Chang Hwan
    • Journal of Korea Trade
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    • 제25권1호
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    • pp.89-111
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    • 2021
  • Purpose - The U.S. Trade Preference Expansion Act (TPEA) of 2015 enables the US Department of Commerce (DOC) to inflate dumping margin when the particular market situation (PMS) exists in the exporter's home market. DOC applied PMS provisions to the steel products from Korea. This paper analyzes whether DOC's calculation by using the regression analysis is consistent with WTO rules. Design/methodology - This paper analyzes the PMS application in law and regression analysis that extends the data period from 10 years to 18 years using the same economic model with DOC, and changes the country group according to the quantities of steelmaking capacity. Findings - Results show that DOC's argument conflating the sales-based with cost-based PMS designed to inflate dumping margins might not be consistent with WTO Antidumping Agreement Article 2.2 and 2.2.1.1 in which costs shall normally be calculated on the basis of records kept by the exporter, providing generally accepted accounting principles and reasonably reflection of the costs and PMS that exists in the Korean steel product markets. Even if it will be consistent, DOC's calculated margin by the regression analysis using a 10-year data is a big gap (5 times) compared with an 18-year data projection and different countries' data through the same methodology, which is a huge gap of regression coefficient. It means that dumping margin would be very wide range from 7.8% to 38.54% and unstable to calculate. Inflating dumping margin by DOC using regression analysis would not only be inconsistent with WTO rules, but also projection result is unreliable. Originality/value - Literature papers have mainly analyzed WTO law itself. This paper however, would be the first attempt to analyze the DOC's new way of dumping margin calculation in both manners of law and an empirical methodology perspective at the same time.

SGA에서 매수인의 계약해제권에 관한 연구: CISG와의 비교를 중심으로 (A Comparative Study on the Right to Avoid the Contract of the Buyer under SGA and CISG)

  • 민주희
    • 아태비즈니스연구
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    • 제11권3호
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    • pp.273-290
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    • 2020
  • Purpose - The purpose of this paper is to examine the buyer's right to avoid the contract under SGA and CISG. Design/methodology/approach - This paper has conducted literature reviews to analyze the right to avoid the contract of the buyer based on the comparative study. Findings - Under s. 11(3) of SGA, the breach of a condition and an intermediate which deprives the buyer substantially of the whole benefit of the contract may give rise to a right to treat the contract as repudiated. But under Art. 49 of CISG, the buyer has the right to terminate the contract where the seller's failure to performance amounts to a fundamental breach of contract. Regarding the breach of an intermediate and the breach under CISG, the buyer should take into account where the seller's breach is fundamental or not. Moreover, an anticipatory breach can give rise to a right to avoid the contract. The anticipatory breach of a condition justifies termination. The breach of an intermediate and the breach under CISG require an anticipatory fundamental breach of the contract. Under SGA, the buyer has to prove an anticipatory breach in fact but CISG does not require virtual certainty, which SGA has stricter criteria to assess an anticipatory breach. Research implications or Originality - Comparative study helps to understand the nature of provisions under SGA and CISG and suggests practical advice to choose applicable laws. SGA gives more certainty to classify a contractual term. In case of the breach of a condition including the anticipatory breach under SGA, the buyer does not have to ask how much serious the breach is. But CISG requires the fundamental breach of the contract, which means that the buyer has the more burden of proof compared with SGA.

Legal Bases for the Interpretation of Contract Terms under the UNIDROIT Principles of International Commercial Contracts

  • Kim, Bong-Chul;Kim, Ho;Shim, Chong-Seok
    • Journal of Korea Trade
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    • 제24권1호
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    • pp.113-130
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    • 2020
  • Purpose - This paper examines the legal standards for the interpretation of contract terms in the UNIDROIT Principles of International Commercial Contracts (PICC) and the cases thereunder in order to provide academic implication to promoting an appropriate understanding of this topic in practical business. Design/methodology - This article uses the literature research and case study under the PICC. Findings - the contract terms shall be interpreted according to the common intention of the parties. If such an intention cannot be established, the contract shall be interpreted according to the meaning that reasonable persons of the same kind as the parties would give to it in the same circumstances. The statements and other conduct of a party shall be interpreted according to that party's intention if the other party knew or could not have been unaware of that intention. If not, the reasonable person standard will apply. In applying above articles, all relevant circumstances including the conduct of the parties, practices and usages shall be considered. Terms and expressions shall be interpreted in the light of the whole contract or statement in which they appear and contract terms shall be interpreted so as to give effect to all the terms rather than to deprive some of them of effect. Where contract terms supplied by one party are unclear, contra proferentem rule applies. Where there is discrepancy between several equally authoritative versions of a contract, a preference is given to the interpretation according to the version originally drawn up. Where the parties to a contract have not agreed regarding an important term for their rights and duties, a term which is appropriate in the circumstances shall be supplied. Originality/value - This article examines various cases regarding the topic that were determined under the PICC. By finding legal standards and rulings of relevant cases, this article will help readers in practical business to enhance the ability to apply the provisions to their contracts.