• Title/Summary/Keyword: combinations of actions

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On the member reliability of wind force-resisting steel frames designed by EN and ASCE rules of load combinations

  • Kudzys, Antanas;Kudzys, Algirdas
    • Wind and Structures
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    • v.12 no.5
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    • pp.425-439
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    • 2009
  • The expediency of revising universal rules for the combination of gravity and lateral actions of wind force-resisting steel structures recommended by the Standards EN 1990 and ASCE/SEI 7-05 is discussed. Extreme wind forces, gravity actions and their combinations for the limit state design of structures are considered. The effect of statistical uncertainties of extreme wind pressure and steel yield strength on the structural safety of beam-column joints of wind force-resisting multistory steel frames designed by the partial factor design (PFD) and the load and resistance factor design (LRFD) methods is demonstrated. The limit state criterion and the performance process of steel frame joints are presented and considered. Their long-term survival probability analysis is based on the unsophisticated method of transformed conditional probabilities. A numerical example illustrates some discrepancies in international design standards and the necessity to revise the rule of universal combinations of loads in wind and structural engineering.

Exploring the Epistemic Actions in Pre-service Teachers' Tasks

  • Jihyun Hwang
    • Research in Mathematical Education
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    • v.26 no.1
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    • pp.19-30
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    • 2023
  • This study analyzes the tasks selected and implemented by pre-service mathematics teachers to support students' development of epistemic actions. Data was collected from 20 students who participated in a mathematics education curriculum theory course during one semester, and multiple data sources were used to gather information about the microteaching sessions. The study focused on the tasks selected and demonstrated during microteaching by pre-service teachers. The results suggest that providing students with a variety of learning opportunities that engage them in different combinations of abductive and deductive epistemic actions is important. The tasks selected by pre-service teachers primarily focused on understanding concepts, calculation, and reasoning. However, the use of engineering tools may present challenges as it requires students to engage in two epistemic actions simultaneously. The study's findings can inform the development of more effective approaches to mathematics education and can guide the development of teacher training programs.

A Method for Learning Macro-Actions for Virtual Characters Using Programming by Demonstration and Reinforcement Learning

  • Sung, Yun-Sick;Cho, Kyun-Geun
    • Journal of Information Processing Systems
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    • v.8 no.3
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    • pp.409-420
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    • 2012
  • The decision-making by agents in games is commonly based on reinforcement learning. To improve the quality of agents, it is necessary to solve the problems of the time and state space that are required for learning. Such problems can be solved by Macro-Actions, which are defined and executed by a sequence of primitive actions. In this line of research, the learning time is reduced by cutting down the number of policy decisions by agents. Macro-Actions were originally defined as combinations of the same primitive actions. Based on studies that showed the generation of Macro-Actions by learning, Macro-Actions are now thought to consist of diverse kinds of primitive actions. However an enormous amount of learning time and state space are required to generate Macro-Actions. To resolve these issues, we can apply insights from studies on the learning of tasks through Programming by Demonstration (PbD) to generate Macro-Actions that reduce the learning time and state space. In this paper, we propose a method to define and execute Macro-Actions. Macro-Actions are learned from a human subject via PbD and a policy is learned by reinforcement learning. In an experiment, the proposed method was applied to a car simulation to verify the scalability of the proposed method. Data was collected from the driving control of a human subject, and then the Macro-Actions that are required for running a car were generated. Furthermore, the policy that is necessary for driving on a track was learned. The acquisition of Macro-Actions by PbD reduced the driving time by about 16% compared to the case in which Macro-Actions were directly defined by a human subject. In addition, the learning time was also reduced by a faster convergence of the optimum policies.

An Analysis and Visualization of Creative Tendency appeared in Query Log of a Story Database Service (스토리 검색 서비스의 사용자 기록에 나타난 창작 성향 분석 및 가시화)

  • Kim, Myoung-Jun
    • Journal of Korea Multimedia Society
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    • v.19 no.8
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    • pp.1609-1618
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    • 2016
  • is a service providing the story synopses that match user's query. This paper analyzes the user log of which is the answers to the queries to find stories from database, and shows the tendency distribution of user creation. Specially, we analyze a joint distribution of the genres and actions of stories to get better understanding of the tendencies that cannot be found in the analysis of independent distribution. Furthermore, we define a correlation factor between genre and action, and investigate what combinations of the genres and actions are highly, less, and negatively correlated. Finally, we investigate how the tendencies of characters are related to genres and actions, and propose a visualization method to show the tendencies.

Analysis of demountable steel and composite frames with semi-rigid bolted joints

  • Wang, Jia;Uy, Brian;Li, Dongxu
    • Steel and Composite Structures
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    • v.28 no.3
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    • pp.363-380
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    • 2018
  • This paper presented an integral design procedure for demountable bolted composite frames with semi-rigid joints. Moment-rotation relationships of beam-to-column joints were predicted with analytical models aiming to provide accurate and reliable analytical solutions. Among this, initial stiffness of beam-to-column joints was derived on the basis of Timoshenko's plate theory, and moment capacity was derived in accordance with Eurocodes. The predictions were validated with relevant test results prior to further applications. Frame analysis was conducted by using Abaqus software with material and geometrical nonlinearity considered. Variable lateral loads incorporating wind actions and earthquake actions in accordance with Australian Standards were adopted to evaluate the flexural behaviour of the composite frames. Strength and serviceability limit state criteria were utilized to verify configurations of designed models. A wide range of frames with the varied number of storeys and bays were thereafter programmed to ascertain bending moment envelopes under various load combinations. The analytical results suggest that the proposed approach is capable of predicting the moment-rotation performance of the semi-rigid joints reasonably well. Outcomes of the frame analysis indicate that the load combination with dead loads and live loads only leads to maximum sagging and hogging moment magnitudes in beams. As for lateral loads, wind actions are more crucial to dominate the design of the demountable composite frames than earthquake actions. No hogging moment reversal is expected in the composite beams given that the frames are designed properly. The proposed analysis procedure is demonstrated to be a simple and efficient method, which can be applied into engineering practice.

Behaviour and design of Grade 10.9 high-strength bolts under combined actions

  • Li, Dongxu;Uy, Brian;Wang, Jia;Song, Yuchen
    • Steel and Composite Structures
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    • v.35 no.3
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    • pp.327-341
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    • 2020
  • The use of high-strength steel and concrete in the construction industry has been gaining increasing attention over the past few decades. With it comes the need to utilise high-strength structural bolts to ensure the design load to be transferred safely through joint regions, where the space is limited due to the reduced structural dimensions. However, research on the behaviour of high-strength structural bolts under various loading combinations is still insufficient. Most of the current design specifications concerning high-strength structural bolts were established based on a very limited set of experimental results. Moreover, as experimental programs normally include limited design parameters for investigation, finite element analysis has become one of the effective methods to assist the understanding of the behaviour of structural components. An accurate and simple full-range stress-strain model for high-strength structural bolts under different loading combinations was therefore developed, where the effects of bolt fracture was included. The ultimate strength capacities of various structural bolts obtained from the present experimental program were compared with the existing design provisions. Furthermore, design recommendations concerning the pure shear and tension, as well as combined shear and tension resistance of Grade 10.9 high-strength structural bolts were provided.

Differential Antioxidant Effects of Ambroxol, Rutin, Glutathione and Harmaline

  • Kim, Hyun-Ho;Jang, Yoon-Young;Han, Eun-Sook;Lee, Chung-Soo
    • Biomolecules & Therapeutics
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    • v.7 no.2
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    • pp.112-120
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    • 1999
  • The protective actions of ambroxol, rutin, glutathione and harmaline on oxidative damages of various tissue components were compared. The mechanisms by which they prevent oxidative tissue damages were explored. Lipid peroxidation of liver microsomes induced by combinations of $Fe^{2+}$ and ascorbate or $Fe^{+3}$, ADP and NADPH was inhibited by $50\; \muM$ of rutin, ambroxol, harmaline and glutathione. Ambroxol ($100\; \muM$) inhibited the degradation of hyaluronic acid by $Fe^{2+}$, $H_2O$_2$ and ascorbate, and it was greater than that of harmaline, whereas hyaluronic acid degradation was not prevented by rutin and glutathione. The compounds used ($100\; \muM$) did not protect the degradation of cartilage collagen by xanthine and xanthine oxidase. Rutin, glutathione and harmaline decreased the degradation of IgG by xanthine and xanthine oxidate, while ambroxol did not attenuate degradation of IgG. Glutathione showed a scavenging action on $H_2O_2$. The compounds all showed scavenging actions on hydroxyl radical. Ambroxol and harmaline exhibited quenching effects en singlet oxygen. In conclusion, ambroxol, rutin, glutathione and harmaline may exert protective effects differently on tissue components against oxidative attack depend on kind of tissue component and free radical.

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Fire resistance tests of LSF walls under combined compression and bending actions

  • Peiris, Mithum;Mahendran, Mahen
    • Steel and Composite Structures
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    • v.43 no.4
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    • pp.483-500
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    • 2022
  • Cold-formed steel wall panels sheathed with gypsum plasterboard have shown superior thermal and structural performance in fire. Recent damage caused by fire events in Australia has increased the need for accurate fire resistance ratings of wall systems used in low- and mid-rise construction. Past fire research has mostly focused on light gauge steel framed (LSF) walls under uniform axial compression and LSF floors under pure bending. However, in reality, LSF wall studs may be subject to both compression and bending actions due to eccentric loading at the wall to-roof or wall-to-floor connections. In order to investigate the fire resistance of LSF walls under the effects of these loading eccentricities, four full-scale standard fire tests were conducted on 3 m × 3 m LSF wall specimens lined with two 16 mm gypsum plasterboards under different combinations of axial compression and lateral load ratios. The findings show that the loading eccentricity can adversely affect the fire resistance level of the LSF wall depending on the magnitude of the eccentricity, the resultant compressive stresses in the hot and cold flanges of the wall studs caused by combined loading and the temperatures of the hot and cold flanges of the studs. Structural fire designers should consider the effects of loading eccentricity in the design of LSF walls to eliminate their potential failures in fire.

A Comparative Study on the Symbolism of the Combination of Animals One Another in East Asian Comedic Stories and Proverbs (동아시아 소화(笑話)·속담(俗談)속의 동물조합 상징성 비교)

  • Keum, Young-Jin
    • Cross-Cultural Studies
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    • v.42
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    • pp.205-240
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    • 2016
  • The combination of animals has been developed in each of the cultural spheres as a method of metaphor and symbolism of the cultural code. However, its symbolism is not a fixed constant, but a variable and relative constant. This work focused on its features in comparison with East Asian cultural spheres comedic stories and proverbs. Consequently, several features were identified. First, the combinations of animals in similar comedic stories and proverbs among Korea, Japan and China show a difference in point of view. Korean focuses on the difference of the two animals, but Chinese and Japanese focus on the differences in value and level. Second, the method of anthropomorphization is relatively more developed in China and Japan than Korea. The combinations of animals of Chinese comedic stories and proverbs particularly in the field of anthropomorphization, are most focused on age and sex of the animal. The animal's age or sex remains mostly undetermined in Korean animal's proverbs, unlike Chinese proverbs. On the other hand, two animals in Japanese comedic stories and proverbs are usually of the male and female gender from. Third, the combinations of animals of Chinese and Japanese focus on the animal's body and its characteristics of action. Chinese and Japanese combine the characteristics of the two animal's bodies and actions. This feature apparently caused the resultant combinations of the animal's body parts, for example, the Dragon. Understanding of the combinations of two animals is a good portal into the features of East Asian culture sphere.

Study on the Improvement of Milling Recovery and Performance (IV) -Rice Whitening Performance of the Combined Abrasive- and Friction-type Whiteners- (도정수율(搗精收率)과 성능향상(性能向上)을 위(爲)한 연구(硏究)(IV) -연삭(硏削)·마찰(磨擦)의 조합식(組合式) 정백작용(精白作用)이 정백성능(精白性能)에 미치는 영향(影響)-)

  • Kim, Sam Do;Chung, Chang Joo;Noh, Sang Ha
    • Journal of Biosystems Engineering
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    • v.7 no.2
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    • pp.72-85
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    • 1983
  • Rice whitening is performed by basically two different whitening actions known as abrasive and frictional. The former adopted in the emery stone abrasive type whiteners and the latter in the jet-air friction type. Comparative milling yields and whitening efficiencies between the whitening system consisting of jet-air friction type whiteners only and the system consisting of both abrasive- and jet-air friction-types have not yet been rigorously defined. This study was to examine the effect of combined operations of abrasive- and jet-air friction-type rice whiteners on milling yields and whitening efficiencies. The small capacity commercial units of the abrasive- and friction-type whiteners were used for the experiments. The combinations of whitening treatments were: 1) Once in the abrasive type and then two to three times in the friction type, 2) twice in the abrasive and then two to three times in the friction type and 3) three to five times in friction type. In these tests, counter pressures for the friction type whiteners were established differently as required to get about the same degree of whitening at the end of predetermined numbers of the repeated operations. The speed of emery stone and the slot angle of the screen were also the factors varied in the abrasive type whitener. Sheukwang rice variety having 13.05% M.C. was used in the tests. The dependent variables were the milled- and head-rice recoveries and electricity consumption. The results of the study are summarized as follows: 1. It was found that in the whitening systems consisting of abrasive- and friction-type whiteners slot angle of the screen, the rotational speed of emery stone roller had significant effect on the milling yields and whitening efficiency. In general, the increase of the emery stone roller speed from 690 to 950 rpm presented a positive effect on milling yield, and one-pass abrasive milling combinations had higher milling yields than two-pass abrasive milling combinations. 2. It was apparent that if the slot angle of the screen and the speed of emery stone roller are modified and set at an optimum level, the combination whitening system consisting of abrasive- and friction-type whiteners is better than the pure frictional whitening system consisting of jet-air friction type in terms of milling yields and efficiencies. 3. In the rice whitening system consisting of abrasive- and jet-air friction-type whiteners, the best whitening performance was obtained when the slot angle of the screen and the rotational speed of emery stone roller were $45^{\circ}$ and 950rpm, respectively, for the one-pass abrasive milling combinations. However, for the two-pass abrasive mi11ing combinations, the best performance was obtained with $75^{\circ}$ of slot angle and 950 rpm of the emery stone roller speed. 4. As compared with pure frictional whitening systems, the combination systems produced more milled rice by 0.8-1.0% point and more head rice by 0.5-1.5% point, and consumed less electricity by 0.15-0.20 KwH per 100kg of milled rice when the abrasive whiteners were operated in the modified conditions as described in item 3 above. Further study is recommended to find out optimum operational and design conditions of abrasive type whiterners.

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