• Journal of applied mathematics & informatics
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• v.7 no.1
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• pp.175-181
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• 2000

The purpose of this to measure, with explicit constants as small as possible, a priori error bounds for approximation by picewise polynomials. These constants play an important role in the numerical verification method of solutions for obstacle problems by using finite element methods .

• Journal of Korean Society of Forest Science
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• v.81 no.3
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• pp.203-213
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• 1992

The purpose of this study is to segment recreationists into groups which are homogeneous with respect to their spending patterns and trip characteristics. Date were derived from a larger study aimed at developing nationally representative expenditure profiles for recreation visitors to Corps of Engineers projects. Segmentation of these data reduces variance and helps to identify distinctive final demand vectors for input - output application. A - priori and cluster analysis approaches for identifying segments are compared. The a - priori segmentation approach identified 12 segments and the cluster analysis approach identified 3 segments. The 3 nonresident clusters - labeled "day use", "overnight", and "overnight camping" - show lower mean squares within groups than the a - priori segments on almost all nonresident spending categories with an exception of boating expenses. For the Corps of Engineers, implications of these findings for the estimation of economic impacts are discussed.

• 전기의세계
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• v.22 no.4
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• pp.17-24
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• 1973

In the view point of practical engineering the identification problem may be considered as a problem to determine the optimal model in the sense of minimizing a given criterion function using the input-output records of the plant. In the system identification the statistical approach has been known to be very effective when the topological structure of the system and the statistical characteristics of the observation noises are known a priori. But in the practical situation there are many cases when the inforhation about the observation noises or the system noises are not available a priori. Here, the authors propose a new identification method which can be used effectively even in the cases when the variances of observation noises are unknown a priori. In the method, the identification of unknown parameters of a linear diserete system is achieved by minimizing the improved quadratic criterion function which is composed of the term of square equation errors and the term to eliminate the affection of observation noises. The method also gives the estimate of noise variance. Numerical computations for several examples show that the proposed procedure gives satisfactory results even when the short time observation data are provided.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.10
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• pp.1255-1263
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• 2004

An a priori test has been conducted for the dynamic mixed model which was generalized for the prediction of passive scalar field in a turbulent channel flow The results from a priori tests indicated that dynamic mixed model is capable of predicting both subgrid-scale heat flux and dissipation rather accurately. The success is attributed to the explicitly calculated resolved term incorporated into the model. The actual test of the model in a LES a posteriori showed that dynamic mixed model is superior to the widely used dynamic Smagorinsky model in the prediction of temperature statistics.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.18 no.3
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• pp.21-26
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• 2010

This paper deals with the precise parameter estimation of an air vehicle without a priori information. First, Recursive Least Squares technique, which is an equation error method and does not require any a priori information, is applied and then the extended Kalman filter is used to tune parameters more precisely. To show the performance, a nonlinear longitudinal missile model is simulated and the parameters are estimated. The results show that this consecutive application of the techniques gives a very good estimation performance.

• Journal of Industrial Technology
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• v.20 no.B
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• pp.201-206
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• 2000

A priori information of object is needed to control in some well known control methods. But we can't always know a priori information of object in real world. In this paper, the inverted pendulum is simulated as a control task with the goal of learning to balance the pendulum with no a priori information using neural network controller. In contrast to other applications of neural networks to the inverted pendulum task, the performance feedback is unavailable on each training step, appearing only as a failure signal when the pendulum falls or reaches the bound of track. To solve this task, the delayed performance evaluation and the learning of nonlinear of nonlinear functions must be dealt. Reinforcement learning method is used for those issues.

• (The)Study of the Eastern Classic
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• no.35
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• pp.275-295
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• 2009

The aim of this paper is to reject Graham's interpretation of bi (必) and xianzhi (先知) of Later Mohists' Mojing ("墨經") as logical necessity and a priori knowledge respectively. Graham's interpretations of them are based on his beliefs that Mojing distinguishes lun (論), the art of description from bian (辯), the art of inference in the Mohist disciplines and that the latter art should be seen as such a rigorous proof as Euclidean geometry even though it is not a Western formal logic. His beliefs also start from his distinguishing 'knowledge of names' from 'knowledge of conjunction of names and objects' according to the objects of knowledge. In my reading, the art of description and the art of inference, however, can't be sharply distinguished each other in Mojing and bi and xianzhi should be taken as suggesting both a normative necessity and an empirical necessity. A normative necessity is derived from 'normative theory of definition' which comes form the theory of rectification of names in China. The normative theory of definition, unlike the descriptive theory of definition, defines terms normatively rather than descriptively. For example, although such a definition of father, 'father is beneficient', has the form of being descriptive, but it actually is prescriptive and therefore means 'father should be beneficient'. Through this normative theory of definition, empirical knowledge, as long as it is a knowledge, is seen as necessary and so can't be wrong. To conclude, for Mohists an empirical knowledge is always a basis of an inferential knowledge or a priori knowledge, so Mohists' a priori knowledge is not really a fundamental knowledge and its necessity therefore is nothing but both a normative necessity and an empirical necessity.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.2
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• pp.379-386
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• 2007

Hado(河圖) and Laks${\u{\lrcorner}}$(書洛) are the diagrams composed of the symbols of numbers from one to ten. And the eight-trigrams, P'al-gwoe divide into two types one is a priori eight-trigrams (先夭八卦) or the Bok-Hui's eight trigrams(伏羲八卦); and the other is a posterior eight trigrams (後夭八卦) or the king Mun's eight trigrams (文王八卦). Relating these two diagrams of Hado and Laks${\u{\lrcorner}}$ with the two types of eight trigrams, they are said to be a term of Ha-Lak-Hui-Mun (HLHM). Each of HLHM represents the process of creating and changing of 'heaven and Earth' and every beingby the symbols of numbers and trigrams. In other words, each of HLHM symbolizes the origin and the structure of the universe as well as the birth of every life represented in the diagram of theosophany (福智學) or Kabbalah. HLHM are also regarded as the origin of l-ching or Book of Change. Hado produces Laks${\u{\lrcorner}}$ through the principle of yin-yang(陰陽). Laks${\u{\lrcorner}}$ produces a priori eight trigrams through the zigzag shapes which means Heaven and Earth are mutually responding. And a priori eight trigrams produce a posteriori eight trigrams through the triangle principle of connecting Heaven and Earth. In this process, Hado and a priori eight trigrams are respectively prior to Laks${\u{\lrcorner}}$ and a posteriori eight trigrams. HLHM represent fractal shape resembling the symbol of five on the center of Hado, or Hado itself. In the dynamic process of HLHM, a diagram of Circle, Quadrangle, and Triangle (CQT) is produced as follows: Circle, the symbol of 'infinify' or Heaven, represents the origin of life or birth. Hadois the symbol of creation. Quadrangle, the symbol of Earth, represents that Laks${\u{\lrcorner}}$is scattered into four directions of front, back, left, and rifht. Quadrangle, which is immovable, represents materiality. Triangle, being described from the eight trigrams, means the movements of the process of 'mutual inclusion' of Circle and Quadrangle. Triangle also means the process of harmonizing human beings with natural law.

• Journal of applied mathematics & informatics
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• v.29 no.1_2
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• pp.369-380
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• 2011

This paper studies a boundary value problem for a linear coupled Luikov's system of heat and mass diffusion in one-dimensional case. Using an a priori estimate, we prove the uniqueness of the solution. Also, some traveling wave solutions and explicit solutions are obtained by using the transformation ${\xi}$ = x - ct and separation method respectively.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.491-494
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• 2001

실제 화자 인증기를 설계함에 있어서 발생하는 가장큰 문제는, 적은 Enrollment data로 화자 모델이 만들어 지므로 화자 인증기의 성능이 시간이 지남에 따라 굉장히 줄어들게 되는 것과, 미리 훈련된 데이터 만으로 Threshold를 설정함에 따라 차후 실제 사용 시에 발생하는 변이를 고려하지 못하여 역시 성능 저하의 문제를 발생시킨다는 것이다. 위의 문제를 해결하기 위해 이 논문은 화자 모델을 구성하는데 있어 MAP 방법을 적용하고, threshold를 Resetting하는 방법을 적용했다. 본 논문에서 제안한 방법으로 HTER값이 23%정도 줄어듦을 보여준다.