• 제목/요약/키워드: comparison principle

검색결과 467건 처리시간 0.027초

Flutter reliability analysis of suspension bridges based on multiplicative dimensional reduction method

  • Guo, Junfeng;Zheng, Shixiong;Zhang, Jin;Zhu, Jinbo;Zhang, Longqi
    • Wind and Structures
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    • 제27권3호
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    • pp.149-161
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    • 2018
  • A reliability analysis method is proposed in this paper based on the maximum entropy (MaxEnt) principle in which constraints are specified in terms of the fractional moments instead of integer moments. Then a multiplicative dimensional reduction method (M-DRM) is introduced to compute the fractional moments. The method is applicable for both explicit and implicit limit state functions of complex structures. After two examples illustrate the accuracy and efficiency of this method in comparison to the Monte Carlo simulation (MCS), the method is used to analyze the flutter reliability of suspension bridge. The results show that the empirical formula method in which the limit state function is explicitly represented as a function of variables is only a too conservative estimate for flutter reliability analysis but is not accurate adequately. So it is not suitable for reliability analysis of bridge flutter. The actual flutter reliability analysis should be conducted based on a finite element method in which limit state function is implicitly represented as a function of variables. The proposed M-DRM provide an alternate and efficient way to analyze a much more complicated flutter reliability of long span suspension bridge.

A New Type of CPPM Machine with Stator Axial Magnetic Ring

  • Xie, Kun;Li, Xinhua;Ma, Jimin;Wu, Xiaojiang;Yi, Hong;Hu, Gangyi
    • Journal of Electrical Engineering and Technology
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    • 제13권3호
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    • pp.1285-1293
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    • 2018
  • This paper proposes a new type of consequent-pole permanent-magnet (CPPM) machine with stator axial magnetic ring that increases torque capability over a wide speed range and enhances efficiency for the built-in rare-earth permanent magnet synchronous machine used in new energy vehicles. The excitation winding of the CPPM hybrid excitation synchronous machine in the stator is replaced by ferrite magnetic ring to simplify the structure and manufacturing process of the machine. The basic structure and magnetic regulation principle of the proposed machine are introduced and compared with the traditional interior rare-earth permanent magnet synchronous machine and CPPM hybrid excitation synchronous machine. Finally, experimental results of a new type of CPPM synchronous motor prototype with axial magnetic ring are introduced in the paper.

Buckling and dynamic behavior of the simply supported CNT-RC beams using an integral-first shear deformation theory

  • Bousahla, Abdelmoumen Anis;Bourada, Fouad;Mahmoud, S.R.;Tounsi, Abdeldjebbar;Algarni, Ali;Bedia, E.A. Adda;Tounsi, Abdelouahed
    • Computers and Concrete
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    • 제25권2호
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    • pp.155-166
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    • 2020
  • In this work, the buckling and vibrational behavior of the composite beam armed with single-walled carbon nanotubes (SW-CNT) resting on Winkler-Pasternak elastic foundation are investigated. The CNT-RC beam is modeled by a novel integral first order shear deformation theory. The current theory contains three variables and uses the shear correction factors. The equivalent properties of the CNT-RC beam are computed using the mixture rule. The equations of motion are derived and resolved by Applying the Hamilton's principle and Navier solution on the current model. The accuracy of the current model is verified by comparison studies with others models found in the literature. Also, several parametric studies and their discussions are presented.

베르누이 원리와 bolt-clamped Langevin type 초음파 진동자를 이용한 정상파 음파 공중부양의 탐구 (Investigation of standing wave acoustic levitation with Bernoulli principle and bolt-clamped Langevin type ultrasonic transducer)

  • 박민철;박두재;김영환
    • 한국음향학회지
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    • 제37권6호
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    • pp.422-427
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    • 2018
  • 본 연구에서는 소형 물체가 음파 정상파의 압력 마디 부근에 소형 물체가 부양하는 정상파 음파 공중부양(standing wave acoustic levitation) 현상에 대해 베르누이 원리를 이용하여 부양의 원인이 되는 음향 방사힘(acoustic radiation force)의 근원과 개형을 기존에 알려진 진동자에서 떨어진 거리에 따른 음향 방사힘의 그래프와 비교함을 통해 개념적으로 설명했다. 이러한 설명을 뒷받침하는 일련의 실험들을 BLT(Bolt-clamped Langevin Type) 초음파 진동자를 이용해서 수행하여, 물체들이 공기의 압력 마디 부근에 부양하고 있음을 확인했고, 물체가 부양하고 있는 상태에서 정상파가 형성되는 조건임을 확인했다. 더불어, 정상파 음파 공중부양 현상에서 부양하는 물체들이 수직하게 일렬로 정렬하는 현상 역시 설명할 수 있었다.

화장실 안전손잡이 위치에 따른 앉은 자세에서 일어서기 비교 (A Comparison of Sit-to-Stand Performance Based on Toilet Grab Bar Positions)

  • 정현애;손유나;이지훈;김희동
    • PNF and Movement
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    • 제17권2호
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    • pp.275-282
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    • 2019
  • Purpose: This study aimed to investigate the optimal positions of safety grab bars for effective sit-to-stand (STS) movement by comparing the results of the STS movement while using a safety grab bar installed under two different conditions: the height of the grab bar installation was determined by (1) the Building Act and (2) the principle of proprioceptive neuromuscular facilitation (PNF). Methods: A total of 50 undergraduate students participated in this study, and they were required to perform an STS movement twice under each condition. A baropodometric platform for sitting and a Biorescue (RM Ingenierie, France) were used to collect and analyze changes in the center of pressure (COP) on the left and right sides before and after performing the STS movement. The average completion time for the STS movement was also measured for analysis. Moreover, the participants were asked to express their individual subjective preferences regarding the two positions of the grab bars. Results: The COP changes were significantly smaller when performing the STS movement with the grab bar installed at the height determined by the PNF principle than the Building Act (p<0.01), and the difference in the completion time of the STS movement was not statistically significant between the two conditions. Conclusion: The findings of this study suggest that the principle of PNF can be useful for planning therapeutic exercise as well as for proposing the optimal grab bar position for older adults and those with health-related issues when performing the STS movement. In addition, this may serve as a basic rehabilitation technique for maintaining remaining functions and providing functional efficiency.

한국 농촌다움 개념 연구 - 농촌다움과 농촌성 연구 비교 중심으로 - (A Study on the Concept of Korean Ruralism - Focusing on the Comparison of Research on Ruralism and Rurality in Korea-)

  • 이동윤;손용훈
    • 농촌계획
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    • 제27권3호
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    • pp.69-84
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    • 2021
  • This study aims to understand the concept of 'ruralism' in Korea by comparing with 'rurality' which were dealt with in various fields related to rural areas in Korea. This study conducted a systematic literature review as a methodology. The process is defining key questions, searching for documents, classifying documents, extracting data, and presenting results. The key questions were set to 'How has the term 'ruralism' been used in various studies?' and 'How can the concept of rurality in Korea be organized?' according to the purpose of the study. The study retrieved literature by searching on Korean academic database, RISS and DBpia, using the five keywords '농촌성', '농촌다움', '농촌다운', 'Rurality,' and 'Ruralism.' The search yielded 1,014 documents which were thereafter screened by systematic literature review process. After sifting, only 31 publications were found suitable for inclusion in the final analysis. This study organized them into four categories: rural concept, rural landscape, rural tourism, and rural development. The literature divided into four types. Type I is a study that deals only with economy·society among studies related to rurality, Type II is a study that deals with both the economic·social and physical environment, Type III is a study that deals with the physical environment of a rural area and presents the rural planning principle as maintenance and preservation. Finally, Type IV is a study that presents ruralism as a new rural planning principle for a future rural area. In the end, the study discussed some implications on defining ruralism in Korea.

Restitution as the Consequence of Frustration under English Law and Korean Law in a Comparative Perspective

  • Joo-Hee Min;Ji-Hyeon Hwang
    • Journal of Korea Trade
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    • 제26권7호
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    • pp.93-108
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    • 2022
  • Purpose - This paper examines the admissibility of restitution as the legal consequence where a contract is frustrated under the Law of Reform (Frustrated Contracts) Act 1943 in comparison with Korean Civil Code (KCC). In order to provide practical guidelines and advice regarding choice of and application of law for contracting parties in international trade, the paper comparatively evaluates requirements and the scope of restitution under the Act 1943 and KCC. Design/methodology - This paper executes a comparative study to analyze whether the parties may claim restitution of money paid or non-money benefit obtained before or after the time of discharge under English law and KCC. To achieve the purpose, it focuses on the identifying characteristics of each statute, thereby providing guidelines to overcome difficulties in legal application and interpretation as to restitution as the consequence of frustration. Findings - Under English law, the benefit may be restituted according to Art 1943 or the common law rule, mistake of fact or law. Under the KCC, restitution is considered based on the principle of the obligation to recover the original obtained regardless of the time when the benefit is conferred. Whilst Act 1943 does not require careful analysis of the grounds of restitution, requirements to justify restitution according to the principle of unjust enrichment, mistake of fact or law, and the KCC should be met. Meanwhile, the KCC may provide more opportunities to award restitution because it does not require the burden of proof related to the defendant's good faith, unlike the principle of unjust enrichment. Originality/value - Where the contract is frustrated by the effect of COVID-19, one legal issue is a consequence of frustration. Therefore, this paper analyzes requirements and the scope of restitution under English law as compared with the KCC in a timely manner. It provides contracting parties with practical guidelines and advice to reduce unpredictability when they choose the governing law in a contract.

산란 주령 및 중량 규격에 따른 계란의 주요 성분 및 내부 품질 비교 (Comparison of Principle Components and Internal Quality of Eggs by Age of Laying Hens and Weight Standard)

  • 이재청;김선효;선창완;김창호;정사무엘;이준헌;조철훈
    • 한국가금학회지
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    • 제40권1호
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    • pp.49-55
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    • 2013
  • 본 연구는 산란 주령과 중량에 따른 계란의 주요 성분과 내부 품질의 변화를 확인하기 위하여 수행되었다. Hy-Line Brown 품종의 18주령에서 63주령으로부터 계란을 주령별로 약 50개씩 총 2,140개를 수거하여 난각, 난황 및 난백의 중량과 난백 높이 그리고 Haugh unit을 측정하였다. 중량 규격이 높아짐에 따라 난각, 난황 및 난백의 중량은 증가하였으나, 난백 높이와 Haugh unit은 낮아짐을 나타내었다. 또한, 산란 주령이 경과함에 따라 난황은 증가하고, 난백 비율은 감소하는 경향을 나타내었으며, 산란 주령은 난각, 난황, 난백 및 전체 계란 중량과 정의 상관관계를 보였으나, 난백 높이와 Haugh unit과는 부의 상관관계를 나타내었다. 또한 계란 중량이나 주요 구성 성분의 중량이 증가함에 따라 난백 높이 및 Haugh unit은 감소하는 것으로 나타났다.

콩의 종류 및 조리방법에 따른 단백질·아미노산 함량 변화 (Protein and Amino-acid Contents in Backtae, Seoritae, Huktae, and Seomoktae Soybeans with Different Cooking Methods)

  • 임정연;김상천;김세나;최용민;양미란;조인희;김행란
    • 한국식품조리과학회지
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    • 제32권5호
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    • pp.567-574
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    • 2016
  • Purpose: The objective of this study was to provide nutritional information (protein and amino-acid contents) of soybeans (Baktae, Seoritae, Huktae, and Seomoktae) with different cooking methods. Methods: Raw, boiled (in $100{\pm}15^{\circ}C$ of water for 4 hr), and fried (in a pan at $110{\pm}15^{\circ}C$ for $20{\pm}5min$) soybean samples were prepared. Contents of protein and amino acids were determined. Results: Protein content in raw Baktae, Seoritae, Huktae, and Seomoktae soybeans ranged from 361.0 to 386.8 mg/g. Protein contents differed according to cooking methods. They were higher in pan-fried beans (107.9-113.5%) than in raw or boiled soybeans (48.2-49.5%). A total of 18 amino acids were analyzed. Amino acid data sets were subjected to principle component analysis (PCA) to understand their differences according to soybean types and cooking methods. Bean samples could be distinguished better according to cooking method in comparison with bean types by principle component (PC1) and PC2. In particular, fried soybeans contained much higher levels of cystein. Other amino acids were the dominant in raw and boiled ones. On the other hand, the amounts of threonine, histidine, proline, arginine, tyrosine, lysine, tryptophan, and methionine were higher in raw bean samples than in cooked ones. Conclusion: The contents of amino-acids and proteins are more effected by different cooking methods in comparison with soybean types.

국제상사중재판정의 준거법선택에 있어서 당사자자치의 원칙 - 당사자에 의한 lex mercatoria의 선택과 준거법 분할지정의 가능여부를 중심으로 - (The Party's Autonomy Principle on the Choice of the Applicable law to International Commercial Arbitral Awards - Focus on the Choice of the Lex Rercatoria and the Possibility of $d\acute{e}pe\c{c}age$ by the Party -)

  • 오석웅
    • 한국중재학회지:중재연구
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    • 제17권1호
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    • pp.117-136
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    • 2007
  • Currently, it is the general trend that the party's autonomy principle is applicable in determining the applicable law for the international private law and the international commercial arbitration. The purpose of this article is to make research on the party's autonomy principle for the international commercial arbitral awards. For this purpose ist to analyse regal issue the applicability of the lex mercatoria and the possibility of $d\acute{e}pe\c{c}age$ relating to the party autonomy. In this Article ist dealt with Art. 29 para. 1 of the Korean Arbitration Act in comparison with Art. 28 para. 1 UNCITRAL Model Law and Art. 1051 para. 1 of the German Code of Civil Procedure. The Art. 28 para. 1 UNCITRAL Model Law and Art. 1051 para. 1 of the German Code of Civil Procedure provides equally. "The arbitral tribunal shall decide the dispute in accordence with such 'rules of law' as chosen by the parties as applicable to the substance of the dispute. Any designation of the law or legal system of a given State shall be construed, unless otherwise expressed, as directly referring to the substantive law of that State and not to its conflict of laws rules." The term 'rule of law' used to describe the applicability of the lex mercatoria and the possibility $d\acute{e}pe\c{c}age$. Unlike Art. 28 para. 1 UNCITRAL Model Law and Art. 1051 para.1 of the German Code of Civil Procedure. Act, Art. 29(1) of the Korean Arbitration Act provides that the arbitral tribunal shall decide the dispute in accordence with the 'law' chosen by the parties as applicable to the substance of the dispute. However the majority view in Korea takes the position that the term 'law' should be interpreted broadly so as to encompass 'rules of law' at UNCITRAL Model Law and the German Code of Civil Procedure.

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