• 제목/요약/키워드: breaking point

검색결과 175건 처리시간 0.025초

A study on properties of sector gear for seat recliner (Seat recliner용 sector gear의 fine blanking에 관한 연구)

  • Kim, Chang-ho;Kang, Soo-ho;Lee, Kwan-young;Nam, Ki-woo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • 제9권1호
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    • pp.99-105
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    • 2010
  • This study was performed to solve the breaking problem in the fine blanking(FB) process of sector gears for car seat recliner using nickel chrome molybdenum steel(SNCM220) plate. The optimal design of embossing circle is changed to oval with labors' experiences and finite element analysis. The maximum principal stress and effective strain in a forming process are analyzed by commercial finite element software to solve the problems in embossing stage of FB process. As a result of FE analysis, the maximum principal stress in forming is lower than yield point of material. It is shown from experiments in the modified die that the formed gear does not break in embossing stage.

A Study in Paper Furniture depending on Production Method (제작기법에 따른 종이가구 연구)

  • Jang, Eun-Jin
    • Journal of the Korea Furniture Society
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    • 제17권1호
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    • pp.73-81
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    • 2006
  • Since early times, paper has been the leading means of expression in human civilization. Along with the development of languages, people have used paper as their major intermediation measures to flourish the culture. At this point of time when studies in latest design are various and abundant, these fixed ideas on paper should be eliminated first for inventive thinking and freedom of expression. Because breaking the established notion helps to diversify the function of paper. We can see furniture made of paper come in useful to our ancestors in their daily life with the development of "Hanjiquot;. Each piece of paper furniture had its own function and beauty depending on processing method. Not only has been used for materials of basic modeling in the process of modern furniture designing, paper has also been used for the main material for the purpose of a new trial. If we try to find out the ways to take diverse characteristics of paper and develop them, while overcoming the defects of the material, paper has great potentiality for many kinds of use in furniture industry.

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Theoretical Studies on the Acid-Catalyzed Hydrolysis of Sulfinamide

  • 김찬경;이익준
    • Bulletin of the Korean Chemical Society
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    • 제18권8호
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    • pp.880-886
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    • 1997
  • Ab initio calculations were carried out on the gas phase acid-catalyzed hydrolysis reactions of sulfinamide using the 3-21G* basis sets. Single point calculations were also performed at the MP2/6-31G* level. The first step in the acid-catalyzed hydrolysis of N-methylmethanesulfinamide, Ⅰ, involves protonation. The most favorable form is the O-protonated one, Ⅱ, which is then transformed into a sulfurane intermediate, Ⅲ, by addition of a water molecule. The reaction proceeds further by an intramolecular proton transfer from O to N (TS2), which is followed by N-S bond cleavage (TS3) leading to the final products. The rate determining step is the N-S bond cleavage (TS3) at the RHF/3-21G* level, whereas it becomes indeterminable at the MP2/6-31G*//3-21G* level of theory. However, the substituent effect studies with N-protonated N-arylmethanesulfinamide, ⅩⅢ, at the MP2/6-31G*//3-21G* level support the N-S bond breaking step as rate limiting.

Categorial Character of Russian Verbal Aspect: Typological Perspective and Grammaticalization (러시아어 동사 상의 범주적 속성: 유형론적 관점과 문법화를 배경으로)

  • Hong, Taek-Gyu
    • Cross-Cultural Studies
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    • 제33권
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    • pp.461-494
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    • 2013
  • The purpose of this work is to analyze categorial character of Russian verbal aspect from the typological perspective. To do this, first of all we will examine the overall historical process of grammaticalization of Russian verbal aspect. As a result of analysis, we have suggested that against wide-spread general assumptions in this area Russian verbal aspect correspond rather to lexico-grammatical category, than to purely typical grammatical category. Actually, I think this kind of approach as a pivotal point for the study of Russian verbal aspect. For example, this kind of typological approach has great advantages in a sense that firstly it gives us possibility of breaking from notorious routine Slavic-Centrism, secondly it can explain sufficiently and adequately various lexico-semantic usages of Russian verbs. Thirdly, our approach consistently accounts for various interactions of lexico-semantic, grammatical, discourse-pragmatic levels, in which Russian verbal aspect is involved. And finally, it sheds light on functional interactions between verbal categories, such as aspect, tense, and mood.

The Deformation and Breaking Load of the Fishing Hook by the Tensile Test (인장시험에 의한 낚시의 변형과 파단하중)

  • KO Kwan-Soh;KIM Yong-Hae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • 제14권4호
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    • pp.269-275
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    • 1981
  • The fishing hooks were tested for breaking and unbending due to plastic deformation of the material. Study of tensile test is not complicated, but has not even worked out fully enough, especially when the test specimen is subjected to plastic deformation. The fishing hook is subjected to unbending stress and the critical section is a Point which is furthest from the line of action of the forces. The dynamic force of fish during jerks depends on their speed of movement and body weight, the kinetic energy corresponding to it and also on the rlastic displacement of the rigging which absorb the energy. Six kinds of hook were tested by the dynamometer under tensile speed 290mm/min (subscript s) and 780mm/min (subscript f). According to their results, the breaking load(B: kg) can be induced with the formula $B={\alpha}wd^2+\beta$ where w(mm) is the distance between the barb base and the lower shank and d(mm) is diameter. The coefficients of the formula for the round hooks(R) and the angular hooks(A) are approximately as follows: $$R:\;\alpha_{s}=0.5,\;\beta_{s}=1.6,\;\alpha_{f}=0.4,\;\beta_{f}=1.4$$ $$A:\;\alpha_{s}=1.1,\;\beta_{s}=2.0,\;\alpha_{f}=1.0,\;\beta_{f}=0.9$$ The ratio of $B_{f}\;to\;B_{s}$ is corresponding to 0.8. The ratio of deformation(X) that is moved distance of barb base at break to the distance(H) between head base and barb base is about $50\%$. Further study should be carried out on the subject of impact and fatigue test under the same condition which is exerted force by the hooked fish.

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MMAD Computation for Fast Diamond-Search Algorithm (고속 다이아몬드 탐색 알고리즘을 위한 MMAD 연산법)

  • 서은주;김동우;한재혁;안재형
    • Journal of Korea Multimedia Society
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    • 제4권5호
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    • pp.406-413
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    • 2001
  • Ordinary high-speed block matching algorithms have a disadvantage that they need to get MAD (Mean Absolute Distance) as many as the number of search points due to comparing the MAD between the current frame's search block and the reference frame's search block. To solve such disadvantage of high-speed block matching algorithm, the proposed high-speed DS algorithm employs a MMAD calculation method using a specific characteristic that neighboring pixels have almost same values. In this thesis, we can get rid of unnecessary MAD calculation between the search point block by the new calculation method which uses the previously calculated MAD as the current search point and by breaking from the established MAD calculation method which calculates the MAD of a new search point by each search stage. Comparing with the established high-speed block matching algorithm, this new calculation's estimated movement error was shown as similar, and th total calculation amount decreased by $2FN^2Ep$.

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A GA-Based Algorithm for Generating a Train Speed Profile Optimizing Energy Efficiency (에너지 최적의 열차 속도 궤적 생성을 위한 GA 기반 알고리즘)

  • Kang, Moon-Ho;Han, Moon-Seob
    • Journal of the Korean Society for Railway
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    • 제12권6호
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    • pp.878-886
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    • 2009
  • This paper proposes an optimal algorithm for generating a train speed profile giving optimal energy efficiency based on GA (Genetic Algorithm) and shows its effectiveness with simulations. After simplifying the train operation mode to a maximum traction, a coasting and a maximum breaking, adjusting the coasting point to minimize the train consuming energy is the basic scheme. Satisfying the two constraints, running distance and running time between two stations, a coasting point is determined by GA with a fitness function consisting of a target running time. Simulation results have shown that multiple coasting points could exist satisfying both of the two constraints. After figuring out consumed energies according to the multiple coasting points, an optimal train speed profile with a coasting point giving the smallest consumed energy has been selected. Simulation blocks for the train performance simulation and GA have been designed with the Simulink.

A Study on the Measurement of Ultrasound Velocity to Evaluate Degradation of Low Voltage Cables for Nuclear Power Plants (원전 저압케이블 열화도 평가를 위한 초음파 음속계측에 관한 연구)

  • Kim, Kyung-Cho;Kang, Suk-Chull;Goo, Charles;Kim, Jin-Ho;Park, Jae-Seok;Joo, Geum-Jong;Park, Chi-Seung
    • Journal of the Korean Society for Nondestructive Testing
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    • 제24권4호
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    • pp.325-330
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    • 2004
  • Several kinds of low voltage cables have been used in nuclear power plants for the supply of electric power, supervision, and the propagation of control signals. These low voltage tables must be inspected for safe and stable operation of nuclear power plants. In particular, the degradation diagnosis to estimate the integrity of low voltage rabies has recently been emphasized according to the long use of nuclear power plants. In order to evaluate their degradation, the surrounding temperature, hardness of insulation material, elongation at breaking point (EAB), etc. have been used. However, the measurement of temperature or hardness is not useful because of the absence of quantitative criteria; the inspection of a sample requires turning off of the power plant power; and, the electrical inspection method is not sufficiently sensitive from the initial through the middle stage of degradation. In this research, based on the theory that the ultrasonic velocity changes with relation to the degradation of the material, we measured the ultrasonic velocity as low voltage cables were degraded. To this end, an ultrasonic degradation diagnosis device was developed and used to measure the ultrasonic velocity with the clothing on the cable, and it was confirmed that the ultrasonic velocity changes according to the degradation of low voltage cables. The low voltage cables used in nuclear power plants were degraded at an accelerated rate, and EAB was measured in a tensile test conducted after the measurement of ultrasonic velocity. With the increasing degradation degree, the ultrasonic velocity decreased, whose potential as a useful parameter for the quantitative degradation evaluation was thus confirmed.

Kinetics and Mechanism of the Pyridinolysis of Aryl Ethyl Chlorothiophosphates in Acetonitrile

  • Adhikary, Keshab Kumar;Lee, Hai-Whang
    • Bulletin of the Korean Chemical Society
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    • 제32권11호
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    • pp.3947-3951
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    • 2011
  • The nucleophilic substitution reactions of Y-aryl ethyl chlorothiophosphates with X-pyridines are studied kinetically in acetonitrile at $55.0^{\circ}C$. The Hammett and Bronsted plots for substituent X variations in the nucleophiles exhibit biphasic concave upwards with a break point at X = 3-Me. The substituents of X = 4-CN and 4-Ac show great positive deviations from both the Hammett and Bronsted plots. The Hammett plots for substituent Y variations in the substrates exhibit biphasic concave upwards with a minimum point at Y = H. The obtained values of the cross-interaction constants (${\rho}_{XY}$) are all in spite of the biphasic free energy correlations for both substituent X and Y variations, since the ${\rho}_X$values with both the strongly and weakly basic pyridines are almost constant. A stepwise mechanism with a rate-limiting leaving group departure from the intermediate is proposed where the distance between X and Y does not vary from the intermediate to the second transition state. A frontside attack is proposed with the strongly basic pyridines based on the considerably great magnitudes of ${\rho}_X$ and ${\beta}_X$ values and a backside attack is proposed with the weakly basic pyridines based on the relatively small magnitudes of ${\rho}_X$ and ${\beta}_X$. The positive deviations of the two strong ${\pi}$-acceptor parasubstituents, X = 4-Ac and 4-CN, from both the Hammett and Bronsted plots are rationalized by the great extents of bond formation and breaking.

The Formative Ceramic Arts by Applying Expression of Cubism (큐비즘적 요소를 응용한 도자 조형)

  • Kim, Seok-Ho;Kim, Seung-Yeon;Kim, Seung-Man
    • The Journal of the Korea Contents Association
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    • 제9권12호
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    • pp.622-629
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    • 2009
  • Modern figurative work is designed to have more creativity and characteristic traits by pure thought of the formative ceramic arts. In compliance with the demand which is various the design development could be satisfied an individuality and a taste is become accomplished. In this view, this study looks over expressive aspect of Cubism to present partition as a independent formative ceramic arts is able to contribute emotionally to our whole lives. In this procedure, this work is produced to express a three-dimensional effect and a spatial effect, approaching a figurative side. This is to overcome the limitation of Cubism art expressed in a two-dimensional surface in spite of its multi-dimensional observation of a given object. Accordingly, this study tries approaching pre-understanding of expressive aspect of Cubism which was the important turning-point in 20c art and expansion of the modern ceramic art field before producing the work. This study shows the possibility to become a creative and practical ceramic art work, approaching the new point of view breaking from the established conception. Consequently, the field of ceramic art could be expanded to a part of modern ceramic art as an object of study in art of life.