• 호남수학학술지
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• 제42권1호
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• pp.49-62
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• 2020

In this paper, we consider interesting binomial and alternating binomial triple sums evaluated in multiplication forms in terms of the Fibonacci and Lucas numbers.

• 품질경영학회지
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• 제15권2호
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• pp.61-68
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• 1987

This paper considers the estimation of the parameters of a normal population from which a sample which has been censored at a known point is obtained. Simple estimators are presented which are given in closed forms. It is shown that maximum likelihood estimators are obtained by using the estimation procedure iteratively. Some computer simulation results are given.

• 대한수학회지
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• 제50권3호
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• pp.479-491
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• 2013

Let M be a smooth real hypersurface in complex space of dimension $n$, $n{\geq}3$, and assume that the Levi-form at $z_0$ on M has at least $(q+1)$-positive eigenvalues, $1{\leq}q{\leq}n-2$. We estimate solutions of the local $\bar{\partial}$-closed extension problem near $z_0$ for $(p,q)$-forms in Sobolev spaces. Using this result, we estimate the local solution of tangential Cauchy-Riemann equation near $z_0$ in Sobolev spaces.

• 건축역사연구
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• 제14권3호
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• pp.53-76
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• 2005

Through a field study of the folk houses, 'Closed ㄱㄴ Type' in Goyang-si, Gyonggj-do, focused on the dweller's life by the method of ethnographic interview, observation, and physical survey. L and opposite L type of inner and outer buildings form a closed inner court, and innermost backyard for woman is enclosed by fence. Form and space of the house contains dweller's traditional life. Outer space of a front gate becomes semiprivate space, for thrashing and piling up harvest and raising vegetables and pigs. Confucius principle does not fully dominate dweller's life of ancestral rite at Daecheong floor, and separation of man's and woman's quarter. Superstitious worship activities took place for lord of site and house. In everyday life, Anbang, inner main room, is assigned for parent's quarter instead of woman's quarter, and Geornbang, next room, was for son's family. Anbang has symbolic meaning for a place of deathbed. House contains agricultural activities, crop harvesting, thrashing, putting into storage, hulling rice, and keeping grain near kitchen. At present, rooms are needed more; sheds are made into rooms, rooms are enlarged toward outside, half outside space like Daechong floor becomes interior space by sash screen. And modern facilities of kitchen and bathroom are equipped for convenience. At the end, meaning and generative principle of those forms are discovered.

• Earthquakes and Structures
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• 제10권1호
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• pp.25-51
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• 2016

In this study, graph product rules are applied to the dynamic analysis of regular skeletal structures. Graph product rules have recently been utilized in structural mechanics as a powerful tool for eigensolution of symmetric and regular skeletal structures. A structure is called regular if its model is a graph product. In the first part of this paper, the formulation of time history dynamic analysis of regular structures under seismic excitation is derived using graph product rules. This formulation can generally be utilized for efficient linear elastic dynamic analysis using vibration modes. The second part comprises of random vibration analysis of regular skeletal structures via canonical forms and closed-form eigensolution of matrices containing special patterns for symmetric structures. In this part, the formulations are developed for dynamic analysis of structures subjected to random seismic excitation in frequency domain. In all the proposed methods, eigensolution of the problems is achieved with less computational effort due to incorporating graph product rules and canonical forms for symmetric and cyclically symmetric structures.

• 한국통신학회논문지
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• 제40권11호
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• pp.2145-2147
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• 2015

본 논문에서는 MRT 및 ZF 프리코딩 기법을 사용하는 Massive MIMO 시스템의 DoF 수에 따른 성능을 분석한다. 본문에서는 하향링크에서 각 MRT 및 ZF 프리코딩 사용시 평균 수신 SINR을 송신 안테나 수에 따라 정규화된 DoF의 수에 대한 Closed-Form으로 도출하였다. 분석 및 모의실험 결과를 통해 DoF 수가 적을 경우 MRT 프리코딩이 ZF 프리코딩 대비 우수한 성능을 달성할 수 있음을 확인하였다.

• 전기의세계
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• 제49권9호
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• pp.9-16
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• 2000

A receding horizon $H_{\infty}$ predictive control method is derived by solving a min-max problem in non-recursive forms. The min-max cost index is converted to a quadratic form which for systems with input saturation can be minimized using QP. Through the use of closed-loop prediction the prediction of states the use of closed-loop prediction the prediction of states in the presence of disturbances are made non-conservative and it become possible to get a tighter $H_{\infty}$ norm bound. Stability conditions and $H_{\infty}$ norm bounds on disturbance rejection are obtained in infinite horizon sence. Polyhedral types of feasible sets for sets and disturbances are adopted to deal with the input constraints. The weight selection procedures are given in terms of LMIs and the algorithm is formulated so that it can be solved via QP. This work is a modified version of an earlier work which was based on ellipsoidal type feasible sets[15].

• 한국정밀공학회지
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• 제11권4호
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• pp.26-37
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• 1994

A kinematically admissible velocity field for the numerical analysis of closed-die forging process of spur gear is proposed. The velocity field is divided into three regions of deformation. In the analysis, the involute curve is approximated to be straight line and the upper-bound method is used to calculate energy dissipation rate. A constant frictional frictional factor has been assumed on the contacting surfaces. The effects of root diameter, number of teeth, and friction factor are determined on the relative forging pressure. The frictionless relative pressure is independent of root diameter for the same number of teeth, but increases with the number of teeth on a given root diameter. In the presence of friction, the relative forging presure increasing root diameter at the start of forging, but decreases with increasing root diameter in the processing of forging.

• Bulletin of the Korean Chemical Society
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• 제12권1호
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• pp.39-47
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• 1991

A cluster made of $N_A,\;N_B\;and\;N_C$ atoms in the x, y and z directions respectively, is treated with Huckel method. We obtain the approximate expressions for the eigenvalues and eigenvectors of f.c.c., b.c.c. and h.c.p. clusters in closed forms. The maximum and minimum values of the band so obtained converge to those derived from the Bloch sum in the limit of infinite extension. For a small cluster (of $9{\times}9{\times}5$ atoms, for instance), LDOS from the analytical (approximate) solution manifests better agreement at the surface, than inside the bulk.

• 대한기계학회논문집A
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• 제24권1호
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• pp.118-123
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• 2000

Most quadruped walking robots under current research are individually controlling every joint ic make them step or walk according to an integrated strategy. Such methods are characterized by at least one pair of an actuator and a sensor installed per each 'oint so that the robots weigh execssively and move inefficiently in terms of energy expenditure. In addition, the task of controlling all the joints simultaneously is quite complex and prone to destabilize the robot motion. These respects keep the existing walking robots away from realistic applications such as transportation even if they have potentially, outstanding adaptability to swamps or uneven terrains as opposed to wheeled vehicles. So, this paper presents a new conceptual quadruped robot developed to walk and steer only with a minimal number of actuators owing to a closed-chain mechanism. To prove its actual performance including the adaptability to various types of terrains. experiments are done with the mammal-type prototype. And. it is also shown that the same concept can be easily extended to carry out different gait forms. for instance, that of spiders only with minor modifications.