• Title/Summary/Keyword: Method of Moments

Search Result 1,135, Processing Time 0.026 seconds

Identifying the scientifically giftedness through brain's cognitive function characteristics (뇌의 인지기능 특성을 통한 과학 영재성 판별)

  • Ha, Jong-Duck;Song, Kyong-Ae
    • Journal of Gifted/Talented Education
    • /
    • v.15 no.2
    • /
    • pp.77-100
    • /
    • 2005
  • This study attempted a new approach to the methods of identifying the scientifically giftedness in relation to the recent emphasis on the education for the scientifically gifted. This study focused on the processes of the cognition achievements, while only the results have been studied until now. Theoretical backgrounds about the ways of identifying the gifted, the research procedures about brain functions, and the information procedures about brain data were reviewed. Eleven scientifically gifted and 10 normal children from the 4th to the 6th grades were selected to analyze the characteristics of their brain waves with brain wave measuring instrument for PCs. The results showed that the scientifically gifted, while studying scientific and creative problems, used their right brain more than their left. When solving these problems, they utilized more of their theta and alpha brain waves than those normal children. In addition, theta brain waves of the scientifically gifted were rather active during these activities and this phenomenon was more distinctive in their right brain rather than their left. Thereby, this study implies that the characteristics of brain waves during the moments of solving certain problems can be used as a method to identify the scientifically gifted.

Magnetic Properties and the Crystallization of Amorphous Nd-Fe-Ti-B (Nd-Fe-Ti-B 비정질 합금의 자기적 성질 연구)

  • 이승화;안성용;김철성;김윤배;김창석
    • Journal of the Korean Magnetics Society
    • /
    • v.7 no.3
    • /
    • pp.140-145
    • /
    • 1997
  • The amorphous state of $NdFe_{10.7}TiB_{0.3}$ and its nanocrystallization have been studied by X-ray diffraction, 모스바우어 spectroscopy, and a vibrating sample magnetometer (VSM), $NdFe_{10.7}TiB_{0.3}$ amorphous ribbons were fabricated by a sigle-roll melt-spinning method. The average hyperfine field $H_{hf}$(T) of the amorphous state shows a temperature dependence of $[H_{hf}(T)-H_{hf}(0)]/H_{hf}(0)=-0.46(T/T_c)^{3/2}-0.34(T/T_c)^{5/2}$ for $T/T_c<0.7$ indicative of spin wave excitation. The quadrupole splitting just above the Curie temperature $T_c$ is 0.46 mm/s, whereas the average quadrupole shift below $T_c$ is zero. The Curie and crystallization temperatures are determined to be $T_c$=380K and $T_x=490K$, respectively, for a heating rate of 5 K/min. The occupied area of nanocrystalline phase at around 770K is about 65%. Above the Curie temperature, VSM data show magnetic moments increases again. The formation of $\alpha$-Fe is the main reason for the increasing moment as conformed with the 모스바우어 measurements.

  • PDF

A Modified Equivalent Frame Model for Plat Plate Slabs Under Lateral Loads (수평하중을 받는 플랫 플레이트 슬래브 해석을 위한 수정된 등가골조모델)

  • Han Sang-Whan;Park Young-Mi
    • Journal of the Korea Concrete Institute
    • /
    • v.17 no.3 s.87
    • /
    • pp.419-426
    • /
    • 2005
  • This study is to propose a modified equivalent frame model for flat plate slabs under lateral loads. ACI 318 (2002) allows equivalent frame methods to conduct two-way slab system analysis subjected to gravity loads as well as lateral loads. Since the equivalent frame method in the ACI 318 (2002) has been developed base on the behavior of two-way system for gravity loads, and nay not predict the behavior of flat plate slabs under lateral loads with good precision. This study develops a modified equivalent frame model which can give more precise answer for flat plate slabs under lateral loads. This model reflects the actual force transfer mechanism among the components of flat plate slab system, which are slabs, columns and torsional members, more accurately under lateral loads than existing equivalent frame models. The accuracy of this model is verified by comparing the analysis results using the proposed model with the results of finite element analysis. The analysis results of other existing models are included in the comparison. For this purpose, 2 story building having 3 spans in both directions is considered. Analytical results show that the modified equivalent frame model produces comparable drift and slab internal moments with those obtained from finite element analysis.

Downscaling Technique of Monthly GCM Using Daily Precipitation Generator (일 강수발생모형을 이용한 월 단위 GCM의 축소기법에 관한 연구)

  • Kyoung, Min Soo;Lee, Jung Ki;Kim, Hung Soo
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.29 no.5B
    • /
    • pp.441-452
    • /
    • 2009
  • This paper describes the evaluation technique for climate change effect on daily precipitation frequency using daily precipitation generator that can use outputs of the climate model offered by IPCC DDC. Seoul station of KMA was selected as a study site. This study developed daily precipitation generation model based on two-state markov chain model which have transition probability, scale parameter, and shape parameter of Gamma-2 distribution. Each parameters were estimated from regression analysis between mentioned parameters and monthly total precipitation. Then the regression equations were applied for computing 4 parameters equal to monthly total precipitation downscaled by K-NN to generate daily precipitation considering climate change. A2 scenario of the BCM2 model was projected based on 20c3m(20th Century climate) scenario and difference of daily rainfall frequency was added to the observed rainfall frequency. Gumbel distribution function was used as a probability density function and parameters were estimated using probability weighted moments method for frequency analysis. As a result, there is a small decrease in 2020s and rainfall frequencies of 2050s, 2080s are little bit increased.

A Study on the Documentary Filming Method for Specific Places - Focus on the documentary and - (장소 특정적 다큐멘터리의 촬영 방식 연구 - 다큐멘터리 <서울역>, <옥포 조선소>를 중심으로 -)

  • Oh, Sehyun
    • Trans-
    • /
    • v.11
    • /
    • pp.37-63
    • /
    • 2021
  • This paper focused on documentaries and for specific places and described the documentary shooting methodology from the perspective of a Cinematographer. 'Old Seoul Station' and 'DSME' (DAEWOO Shipbuilding & Marine Engineering Co., Ltd.) are monumental spaces that reflect the value of Korea modernization and are shared by Koreans' collective memories, unconsciousness, and unique feelings for the place. 'Old Seoul Station' has changed its place identity to a new space called "Culture Station Seoul 284." 'DSME' is a large-scale industrial complex that still functions actively, and it is like an organism that seeks to change according to changes in its industrial structure. and observe and record images of space related to place identity and the people related to it. It shows the construction of staring into a space in a particular place and continuously recording and placing moments of experience, such as the appearance of people working and resting. If it is not recorded through this, it allows us to see intangible narratives related to volatile place identity, and enables specific place experiences through theaters. This study focuses on production theory based on examples of documentary filming methods for these specific places.

Segmentation Method of Overlapped nuclei in FISH Image (FISH 세포영상에서의 군집세포 분할 기법)

  • Jeong, Mi-Ra;Ko, Byoung-Chul;Nam, Jae-Yeal
    • The KIPS Transactions:PartB
    • /
    • v.16B no.2
    • /
    • pp.131-140
    • /
    • 2009
  • This paper presents a new algorithm to the segmentation of the FISH images. First, for segmentation of the cell nuclei from background, a threshold is estimated by using the gaussian mixture model and maximizing the likelihood function of gray value of cell images. After nuclei segmentation, overlapped nuclei and isolated nuclei need to be classified for exact nuclei analysis. For nuclei classification, this paper extracted the morphological features of the nuclei such as compactness, smoothness and moments from training data. Three probability density functions are generated from these features and they are applied to the proposed Bayesian networks as evidences. After nuclei classification, segmenting of overlapped nuclei into isolated nuclei is necessary. This paper first performs intensity gradient transform and watershed algorithm to segment overlapped nuclei. Then proposed stepwise merging strategy is applied to merge several fragments in major nucleus. The experimental results using FISH images show that our system can indeed improve segmentation performance compared to previous researches, since we performed nuclei classification before separating overlapped nuclei.

Bio-Sensing Convergence Big Data Computing Architecture (바이오센싱 융합 빅데이터 컴퓨팅 아키텍처)

  • Ko, Myung-Sook;Lee, Tae-Gyu
    • KIPS Transactions on Software and Data Engineering
    • /
    • v.7 no.2
    • /
    • pp.43-50
    • /
    • 2018
  • Biometric information computing is greatly influencing both a computing system and Big-data system based on the bio-information system that combines bio-signal sensors and bio-information processing. Unlike conventional data formats such as text, images, and videos, biometric information is represented by text-based values that give meaning to a bio-signal, important event moments are stored in an image format, a complex data format such as a video format is constructed for data prediction and analysis through time series analysis. Such a complex data structure may be separately requested by text, image, video format depending on characteristics of data required by individual biometric information application services, or may request complex data formats simultaneously depending on the situation. Since previous bio-information processing computing systems depend on conventional computing component, computing structure, and data processing method, they have many inefficiencies in terms of data processing performance, transmission capability, storage efficiency, and system safety. In this study, we propose an improved biosensing converged big data computing architecture to build a platform that supports biometric information processing computing effectively. The proposed architecture effectively supports data storage and transmission efficiency, computing performance, and system stability. And, it can lay the foundation for system implementation and biometric information service optimization optimized for future biometric information computing.

Prediction of Expected Residual Useful Life of Rubble-Mound Breakwaters Using Stochastic Gamma Process (추계학적 감마 확률과정을 이용한 경사제의 기대 잔류유효수명 예측)

  • Lee, Cheol-Eung
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.31 no.3
    • /
    • pp.158-169
    • /
    • 2019
  • A probabilistic model that can predict the residual useful lifetime of structure is formulated by using the gamma process which is one of the stochastic processes. The formulated stochastic model can take into account both the sampling uncertainty associated with damages measured up to now and the temporal uncertainty of cumulative damage over time. A method estimating several parameters of stochastic model is additionally proposed by introducing of the least square method and the method of moments, so that the age of a structure, the operational environment, and the evolution of damage with time can be considered. Some features related to the residual useful lifetime are firstly investigated into through the sensitivity analysis on parameters under a simple setting of single damage data measured at the current age. The stochastic model are then applied to the rubble-mound breakwater straightforwardly. The parameters of gamma process can be estimated for several experimental data on the damage processes of armor rocks of rubble-mound breakwater. The expected damage levels over time, which are numerically simulated with the estimated parameters, are in very good agreement with those from the flume testing. It has been found from various numerical calculations that the probabilities exceeding the failure limit are converged to the constraint that the model must be satisfied after lasting for a long time from now. Meanwhile, the expected residual useful lifetimes evaluated from the failure probabilities are seen to be different with respect to the behavior of damage history. As the coefficient of variation of cumulative damage is becoming large, in particular, it has been shown that the expected residual useful lifetimes have significant discrepancies from those of the deterministic regression model. This is mainly due to the effect of sampling and temporal uncertainties associated with damage, by which the first time to failure tends to be widely distributed. Therefore, the stochastic model presented in this paper for predicting the residual useful lifetime of structure can properly implement the probabilistic assessment on current damage state of structure as well as take account of the temporal uncertainty of future cumulative damage.

Optimum Design of Two Hinged Steel Arches with I Sectional Type (SUMT법(法)에 의(依)한 2골절(滑節) I형(形) 강재(鋼材) 아치의 최적설계(最適設計))

  • Jung, Young Chae
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.12 no.3
    • /
    • pp.65-79
    • /
    • 1992
  • This study is concerned with the optimal design of two hinged steel arches with I cross sectional type and aimed at the exact analysis of the arches and the safe and economic design of structure. The analyzing method of arches which introduces the finite difference method considering the displacements of structure in analyzing process is used to eliminate the error of analysis and to determine the sectional force of structure. The optimizing problems of arches formulate with the objective functions and the constraints which take the sectional dimensions(B, D, $t_f$, $t_w$) as the design variables. The object functions are formulated as the total weight of arch and the constraints are derived by using the criteria with respect to the working stress, the minimum dimension of flange and web based on the part of steel bridge in the Korea standard code of road bridge and including the economic depth constraint of the I sectional type, the upper limit dimension of the depth of web and the lower limit dimension of the breadth of flange. The SUMT method using the modified Newton Raphson direction method is introduced to solve the formulated nonlinear programming problems which developed in this study and tested out throught the numerical examples. The developed optimal design programming of arch is tested out and examined throught the numerical examples for the various arches. And their results are compared and analyzed to examine the possibility of optimization, the applicablity, the convergency of this algorithm and with the results of numerical examples using the reference(30). The correlative equations between the optimal sectional areas and inertia moments are introduced from the various numerical optimal design results in this study.

  • PDF

THREE-DIMENSIONAL FINITE ELEMENT ANALYSIS OF THE PHENOMENON PRODUCED DURING RETRACTION OF FOUR MAXILLARY INCISORS (상악 4절치의 후방견인시 나타나는 현상에 관한 유한요소법적 분석)

  • Cheon, Ok-Jin;Kim, Tae-Woo;Suhr, Cheong-Hoon
    • The korean journal of orthodontics
    • /
    • v.25 no.5 s.52
    • /
    • pp.525-541
    • /
    • 1995
  • This study was designed to investigate force systems and tooth movements produced by retraction archwire during retraction of four maxillary incisors after the maxillary canine retraction into the maxillary first premolar extraction space using the computer-aided three-dimensional finite element method. A three-dimensional finite element model, consisting of 2248 elements and 3194 nodes, was constructed. The model consisted of maxillary teeth and surrounding periodontal membranes, .022'$\times$.028'-slot brackets, and 5 types of retraction archwires(.019'$\times$.025' stainless steel archwire) modeled using the beam elements. The contact between the wire and the bracket slot was modeled using the gap elements because of the non-linear elastic behaviors of the contact between them. The forces and moments, End displacements produced by retraction archwire were measured at various conditions to investigate the difference according to types of loops, magnitudes of activation force, gable angle, and anterior lingual root torque. The results were expressed quantitative and visual ways in the three-dimensional method. The following conclusions can be drawn from this study.1. When the tear-drop loop archwire was activated, the mesio-distal and lingual translational movements of the teeth helped to close the extraction space, but unwanted movements of the teeth including intrusions and extrusions, and rotational movements in each direction occurred. 2. Activation of T-loop archwire compared with those of other types of retraction archwires produced the least translational movements of the teeth helped to space closure and also the least unwanted movements of the teeth. 3. Increasing amount of activation in the tear-drop archwire led not only to increase of translational movements of the teeth helped to space closure, but also to increase of unwanted movements of the teeth. 4. Addition of gable bend in the tear-drop archwire helped anterior teeth to translational movements in the mesio-distal direction, but increased unwanted movements of the teeth 5. Addition of anterior lingual root torque in the tear-drop archwire helped central and lateral incisor to improve their facio-lingual inclination, but increased unwanted movements of the teeth.

  • PDF