• Title/Summary/Keyword: Second moment method

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Influence of Children's Gender and Surrounding's Variables on School Readiness : Based on Educational Level of Parents, Educational Participation of Mother, Teaching Method of Teacher and Literacy Conditions of Home and Class (유아의 성과 주변 환경 변인이 학교준비도에 미치는 영향 : 부모의 교육수준, 어머니의 학습관여, 교사의 지도방법 및 가정과 교실의 문해환경을 중심으로)

  • Lee, Soo Hyun;Hwang, Hye Jung
    • Korean Journal of Childcare and Education
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    • v.10 no.4
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    • pp.177-203
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    • 2014
  • This thesis is to figure out the influences of children's gender, educational level of parents, educational participation of the mother, teaching method of teacher and literacy conditions of home and class on preschool children's school readiness. The objects of this study are 141 preschool children under 5 years old, 141 parents and 42 class teachers. Test for School Readiness, Measure of Mother's Educational Participation, Measure of Teacher's Teaching Method, and Measures of Literacy Condition of Home and Class are used as a studying tool. Collected materials were analyzed by Three-way ANOVA, Correlation analysis of Spearman, product-moment correlation analysis of Pearson, and phased regression analysis. The results are as follows: First, there are meaningful differences between the gender of children and mother's educational level for the school readiness. Second, except for the home's literacy condition, children's gender, educational level of parents, educational participation of mother, teaching method of teacher and literacy conditions of class show the meaningful positive correlation with the children's school readiness. Third, the adaptive zone, which is the subordinated zone, is affected by the gender of children, and the knowledge zone is influenced by the mother's educational level most. These results will be useful for the basic data that can help to promote school readiness for children's parents and teachers.

Reliability Analysis of Plane Stress Element According to Limit State Equations (한계상태방정식에 따른 평면응력요소의 신뢰성해석)

  • Park, Seok Jae;Choi, Wae Ho;Kim, Yo Suk;Shin, Yeong-Soo
    • Journal of Korean Society of Steel Construction
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    • v.13 no.5
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    • pp.567-575
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    • 2001
  • In order to consider statistical properties of probability variables used in the structural analysis the conventional approach using the safety factor based on past experience usually estimated the safety of a structure Also the real structures could only be analyzed with the error in estimation of loads material characters and the dimensions of the members. But the errors should be considered systematically in the structural analysis Safety of structure could not precisely be appraised by the traditional structural design concept Recently new aproach based on the probability concept has been applied to the assessment of structural safety using the reliability concept Thus the computer program by the Probabilitstic FEM is developed by incorporating the probabilistic concept into the conventional FEM method. This paper estimated for the reliability of a plane stress structure by Advanced First-Order Second Moment method using von Mises, Tresca and Mohr-Coulomb failure criterions. Verification of the reliability index and failure probability of attained by the Monte Carlo Simulation method with the von Mises criterion were same as PFEM, but the Monte Carlo Simulation were very time-consuming. The variance of member thickness and load could influence the reliability and failure probability most sensitively among the design variables from the results of the parameter analysis. The proper failure criterion according to characteristic of materials must be used for safe design.

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Probability Distribution of Nonlinear Random Wave Heights Using Maximum Entropy Method (최대 엔트로피 방법을 이용한 비선형 불규칙 파고의 확률분포함수)

  • 안경모
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.10 no.4
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    • pp.204-210
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    • 1998
  • This paper presents the development of the probability density function applicable for wave heights (peak-to-trough excursions) in finite water depth including shallow water depth. The probability distribution applicable to wave heights of a non-Gaussian random process is derived based on the concept of the maximum entropy method. When wave heights are limited by breaking wave heights (or water depth) and only first and second moments of wave heights are given, the probability density function developed is closed form and expressed in terms of wave parameters such as $H_m$(mean wave height), $H_{rms}$(root-mean-square wave height), $H_b$(breaking wave height). When higher than third moment of wave heights are given, it is necessary to solve the system of nonlinear integral equations numerically using Newton-Raphson method to obtain the parameters of probability density function which is maximizing the entropy function. The probability density function thusly derived agrees very well with the histogram of wave heights in finite water depth obtained during storm. The probability density function of wave heights developed using maximum entropy method appears to be useful in estimating extreme values and statistical properties of wave heights for the design of coastal structures.

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A Study for Quality of Life in Musically Talented Students Using Experience Sampling Method (경험표집법(ESM)을 통해 본 음악영재의 삶의 질)

  • Lee, Hyun-Joo;Choe, In-Soo
    • Journal of Gifted/Talented Education
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    • v.21 no.1
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    • pp.57-81
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    • 2011
  • The purpose of this study was to explore the quality of life of musically talented students as measured by their external experiences (e.g., activities, companions) and internal experiences (e.g., flow, emotion). The participants in this study were 33 musically talented students (10 males, 23 females) aged 13 to 19. Study data were collected for 7 consecutive days using the Experience Sampling Method (ESM), which employs a cellular-phone as a signaling device. The results were as follows: First, in response to the 1625 random signals, musically talented students reported that 40.9% of their time was spent on productive activities. An additional 33.4% of time was used for maintenance activities and the rest of their time was spent on leisure/social activities. Also, musically talented students reported that 48.5% of their time was spent alone. When they were alone, they spent a lot of time engaging in productive activities (44.3%). Second, in order to measure the flow of their life, two methods were used. One used a 4-channel flow model (i.e. apathy, boredom, flow, anxiety) and the other used 8 dimensions and conditions of the flow experience (i.e. concentration, self-consciousness disappears, action and awareness merge, distorted sense of time, freedom from worry about failure, clear goals, immediate feedback, balance between challenges and skills). According to the former, when engaged in music-related activities, musically talented students usually reported flow (54.0%), while they felt apathy (41.3%) for daily routines activities. According to the latter method, musically talented students experienced flow for most productive activities, while they experienced flow least for maintenance activities. Emotional variables of ESF are comprised of 10 semantic scales (i.e. happy-sad, strong-weak, active-passive, sociablelonely, proud-ashamed, involved-detached, excited-bored, clear-confused, relaxed-worried, cooperative-competitive). Musically talented students reported experiencing the most positive emotion for social activities and experiencing the most negative emotion for maintenance activities. Results of this study assert that musically talented students had to trade off immediate enjoyment for developing their special gifts. They could not afford as much time for socializing with friends, and they had to spend more time alone compared to their peers without such gifts. Consequently, they were found to deprive themselves of the spontaneous good times that teenagers usually thrive on. They were helped in this respect by their autotelic personality traits, especially their strong need for achievement and endurance. The downside, however, is that the moment-to-moment quality of their moods suffered. The argument concerning musically talented students applies for all adolescents. The choices that talented students must make between immediate gratification and long-term development, and between solitude and companionship, are the same choices every young person must make, regardless of her or his level of talent. All of us have gifts that are potentially useful and worthy of being appreciated. But to develop these latent talents we must cultivate them, and this takes time and the investment of mental energy. The lifestyle that musically talented students develop can show us some of the choices all of us must make in order to cultivate our gifts.

Weaving the realities with video in multi-media theatre centering on Schaubuhne's Hamlet and Lenea de Sombra's Amarillo (멀티미디어 공연에서 비디오를 활용한 리얼리티 구축하기 - 샤우뷔네의 <햄릿>과 리니아 드 솜브라의 <아마릴로>를 중심으로 -)

  • Choi, Young-Joo
    • Journal of Korean Theatre Studies Association
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    • no.53
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    • pp.167-202
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    • 2014
  • When video composes mise-en-scene during the performance, it reflects the aspect of contemporary image culture, where the individual as creator joins in the image culture through the device of cell phone and computer remediating the former video technology. It also closely related with the contemporary theatre culture in which 1960's and 1970's video art was weaved into the contemporary performance theatre. With these cultural background, theatre practitioners regarded media-friendly mise-en-scene as an alternative facing the cultural landscape the linear representational narrative did not correspond to the present culture. Nonetheless, it can not be ignored that video in the performance theatre is remediating its historical function: to criticize the social reality. to enrich the aesthetic or emotional reality. I focused video in the performance theatre could feature the object with the image by realizing the realtime relay, emphasizing the situation within the frame, and strengthening the reality by alluding the object as a gesutre. So I explored its two historical manuel. First, video recorded the spot, communicated the information, and arose the audience's recognition of the object to its critical function. Second, video in performance theatre could redistribute perceptual way according to the editing method like as close up, slow motion, multiple perspective, montage and collage, and transformation of the image to the aesthetic function. Reminding the historical function of video in contemporary performance theatre, I analyzed two shows, Schaubuhne's Hamlet and Lenea de Sombra's Amarillo which were introduced to Korean audiences during the 2010 Seoul Theatre Olympics. It is known to us that Ostermeir found real social reality as a text and made the play the context. In this, he used video as a vehicle to penetrate the social reality through the hero's perspective. It is also noteworthy that Ostermeir understood Hamlet's dilemma as these days' young generation's propensity. They delayed action while being involved in image culture. Besides his use of video in the piece revitalized the aesthetic function of video by hypermedial perceptual method. Amarillo combined documentary theatre method with installation, physical theatre, and video relay on the spot, and activated aesthetic function with the intermediality, its interacting co-relationship between the media. In this performance theatre, video has recorded and pursued the absent presence of the real people who died or lost in the desert. At the same time it fantasized the emotional aspect of the people at the moment of their death, which would be opaque or non prominent otherwise. As a conclusion, I found the video in contemporary performance theatre visualized the rupture between the media and perform their intermediality. It attempted to disturb the transparent immediacy to invoke the spectator's perception to the theatrical situation, to open its emotional and spiritual aspect, and to remind the realities as with Schaubuhne's Hamlet and Lenea de Sombra's Amarillo.

Lower Limbs Muscle Comparative Research for Verification Effect of Rehabilitation Training Program of Total Hip Arthroplasty (재활운동 프로그램에 참가한 엉덩인공관절 수술자의 하지근력 변화에 대한 비교연구)

  • Jin, Young-Wan
    • Journal of Life Science
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    • v.20 no.4
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    • pp.543-548
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    • 2010
  • The purpose of this study was to examine the differences in kinetics between 6 months of rehabilitation training and 12 months of rehabilitation training after total hip arthroplasty. 10 unilateral THA participants performed kinetic tests. Three dimensional kinematics and hip flexors and abductors electromyography (EMG) were collected during each trial. T-test was used for statistical analysis (p<0.05). There was no significant difference in EMG data between the two groups, but the mean comparison EMG data was higher in the 12 months rehabilitation training group than the 6 months rehabilitation training group. The moment value was found with motion-dependent interaction analyzing method which was used by Feltner and Dapena. There was no significant difference between moment values of the two groups. There was no significant difference between ground reaction forces of the two groups; however, there were some differences shown in Fz (vertical reaction force) between the two groups ($892{\pm}104\;N$, $820{\pm}87\;N$). The first peak impact force was about 9% lower in the 12 months group compared to the 6 months group. The second peak active force was nearly equal between the two groups. More research is necessary to determine exactly what constitutes optimal rehabilitation training biomechanics for patients with total hip arthroplasty.

Water droplet generation technique for 3D water drop sculptures (3차원 물방울 조각 생성장치의 구현을 위한 물방울 생성기법)

  • Lin, Long-Chun;Park, Yeon-yong;Jung, Moon Ryul
    • Journal of the Korea Computer Graphics Society
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    • v.25 no.3
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    • pp.143-152
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    • 2019
  • This paper presents two new techniques for solving the two problems of the water curtain: 'shape distortion' caused by gravity and 'resolution degradation' caused by fine satellite droplets around the shape. In the first method, when the user converts a three-dimensional model to a vertical sequence of slices, the slices are evenly spaced. The method is to adjust the time points at which the equi-distance slices are created by the nozzle array. In this method, even if the velocity of a water drop increases with time by gravity, the water drop slices maintain the equal interval at the moment of forming the whole shape, thereby preventing distortion. The second method is called the minimum time interval technique. The minimum time interval is the time between the open command of a nozzle and the next open command of the nozzle, so that consecutive water drops are clearly created without satellite drops. When the user converts a three-dimensional model to a sequence of slices, the slices are defined as close as possible, not evenly spaced, considering the minimum time interval of consecutive drops. The slices are arranged in short intervals in the top area of the shape, and the slices are arranged in long intervals in the bottom area of the shape. The minimum time interval is pre-determined by an experiment, and consists of the time from the open command of the nozzle to the time at which the nozzle is fully open, and the time in which the fully open state is maintained, and the time from the close command to the time at which the nozzle is fully closed. The second method produces water drop sculptures with higher resolution than does the first method.

A First-principles Study on the Effects on Magnetism of Si Impurity in BCC Fe by Considering Spin-orbit Coupling (스핀-궤도 상호작용을 고려한 Si 불순물이 BCC Fe의 자성에 미치는 영향에 대한 제일원리연구)

  • Rahman, Gul;Kim, In-Gee;Chang, Sam-Kyu
    • Journal of the Korean Magnetics Society
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    • v.18 no.6
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    • pp.211-216
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    • 2008
  • The effects of Si impurity on electronic structures and magnetism of bcc Fe are investigated by using a first-principles method by considering spin-orbit coupling. In order to describe the Si impurity, a 27 atomic bcc Fe supercell has been considered. The Kohn-Sham equation was solved in terms of the all-electron full-potential linearized augmented plane wave (FLAPW) method within the generalized gradient approximation (GGA). The effects of spin-orbit coupling were calculated self-consistently by considering spin-diagonal terms based on second variation method. For the ferromagnetic (FM) state without considering SOC, the spin magnetic moment of the Si impurity was calculated to be $-0.143{\mu}B$, while the magnetic moments of Fe atoms were calculated to be $2.214{\mu}B$, $2.327{\mu}B$, and $2.354{\mu}B$ in away from the Si atom, respectively. However, the FM state with considering SOC, the spin magnetic moment of the Si impurity was calculated to be $-0.144{\mu}B$, which is not affected significantly by SOC, but the spin magnetic moments of Fe atoms were calculated $2.189{\mu}B$, $2.310{\mu}B$, and $2.325{\mu}B$, respectively, which are much reduced value compared to those of the FM state without SOC. Comparing the total charge density and spin density, those features are thought to be originated by the screening distortions of the Fe $t_{2g}$ orbital, which can be obtained by considering SOC.

Dynamic Modeling and Simulation of a Towing Rope using Multiple Finite Element Method (다물체 요소이론을 이용한 예인줄 동역학의 모델링 및 시뮬레이션)

  • Yoon, Hyeon-Kyu;Lee, Hong-Seok;Park, Jong-Kyu;Kim, Yeon-Gyu
    • Journal of Navigation and Port Research
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    • v.36 no.5
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    • pp.339-347
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    • 2012
  • After towing rope connecting a barge to a tug was subdivided into multiple finite elements, then those dynamic models was established using Newton's second law and considering the external force and moment such as tension, drag, Coriolis force, gravity, buoyancy, and impact due to free surface acting on each element. While the previous research on the model of towing rope considered only translation, five-degree-of-freedom equations of motion except roll based on the body-fixed frame were established in this paper. All elements are connected by a spring and a damper, and the stiffness of the spring was set as the equivalent value of the real rope. In order to confirm the established multiple finite element model, various scenarios such as freely falling of towing rope in the air and above the free surface, accelerating of a tug which tows a barge connected by towing rope, and sinusoidal moving of a tug were set up and simulated. As the results, the trajectories of the tug, the barge, and the towing rope showed good tendencies to the ones of real expected situations.

Determination of Resistance Factors of Load and Resistance Factor Design for Drilled Shaft Based on Load Test (LRFD 설계를 위한 현장타설말뚝의 주면지지력 저항계수 산정)

  • Kim, Seok-Jung;Kwon, Oh-Sung;Jung, Sung-Jun;Han, Jin-Tae;Kim, Myoung-Mo
    • Journal of the Korean Geotechnical Society
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    • v.26 no.7
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    • pp.17-24
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    • 2010
  • Load Resistance Factor Design method is used increasingly in geotechnical design world widely and resistance factors for drilled shafts are suggested by AASHTO. However, these resistance factors are determined for intact rock conditions; by comparison, most of bedrocks in Korea have weathered condition, so that applying the AASHTO resistance factors is not reasonable. Thus, this study suggests the proper resistance factors for design of drilled shaft in Korea. The 22 cases of pile load test data from 8 sites were chosen and reliability-based approach is used to analyze the data. Reliability analysis was performed by First Order Second Moment Method (FOSM) applying 4 bearing capacity equations. As a result, when the Factor of Safety (FOS) was selected as 3.0, the target reliability indexes (${\beta}_c$) were evaluated as 2.01~2.30. Resistance factors and load factors are determined from optimization based on above results. The resistance factors ranged between 0.48 and 0.56 and load factors for dead load and live load are evaluated as approximately 1.25 and 1.75 respectively. However, when the target reliabilities are considered as 3.0, the resistance factors are evaluated as approximately 50% of the results when the target reliability index was 2.0.