• Journal of Information Processing Systems
• /
• 제17권2호
• /
• pp.306-317
• /
• 2021

The unbalance between system ergodic sum rate and high fairness is one of the key issues affecting the performance of non-orthogonal multiple access (NOMA) system. To solve the problem, this paper proposes a power allocation algorithm to realize the ergodic sum rate maximization of NOMA system. The scheme is mainly achieved by the construction algorithm of fair model based on α fair utility function and the optimal solution algorithm based on the interior point method of penalty function. Aiming at the construction of fair model, the fair target is added to the traditional power allocation model to set the reasonable target function. Simultaneously, the problem of ergodic sum rate and fairness in power allocation is weighed by adjusting the value of α. Aiming at the optimal solution algorithm, the interior point method of penalty function is used to transform the fair objective function with unequal constraints into the unconstrained problem in the feasible domain. Then the optimal solution of the original constrained optimization problem is gradually approximated within the feasible domain. The simulation results show that, compared with NOMA and time division multiple address (TDMA) schemes, the proposed method has larger ergodic sum rate and lower Fairness Index (FI) values.

• Journal of Electrical Engineering and Technology
• /
• 제13권2호
• /
• pp.752-760
• /
• 2018

In this paper, interior permanent magnet synchronous motor (IPMSM) design for sensorless drive, considering magnetic neutral point shift according to magnetic saturation, has been proposed. Sensorless control was divided into a method based on inductance and a method based on back induced voltage. Because induced voltage is very small at zero or low speed, error in rotor initial position estimation may occur. Using the ratio of saliency addresses this problem. When using high-frequency injections at low speed, the rotor's initial position is estimated at the smallest portion of the inductance. IPMSM has the minimum inductance at the d-axis. However, if magnetic saturation leads to magnetic neutral point variation, following the load current change, there is a change in the minimum point of inductance. In this case, it can lead to failure of initial rotor position estimation. As a result, it is essential that the blocking design has an inductance minimum point shift. As such, in this study, an IPMSM design method, by blocking magnetic neutral point change, has been proposed. After determining the inductance profile based on the finite element analysis (FEA), the results of proposed method were verified.

• 한국실내디자인학회논문집
• /
• 제18권4호
• /
• pp.71-78
• /
• 2009

This study analyzed the observation characteristics on space by analyzing through the visual perception experiment to the image dates from the original space and the rotated space of it. The results of this study are as fellow as: First, most frequently observed points were, lower end mainly from the center was more observed in the original space while upper end mainly from the center was more observed in the rotated space. Therefore, it is able for us to learn whether the space has the same design, the length of time focusing on one point differentiates as the image rotates. Second, differentiation in observation part, as shown in the case study, can be seen as a consequence of changes in perspective composition. The test indicates that when a design is presented to an observer, the observer's examining point would vary according to where the indoor perspective drawing places a vanishing point. Third, in zones I and II, observation was focused on lower end in the original picture while on the rotated picture there were more focus on the upper end and perpendicularity view of the indoor. Fourth, this study analyzed the mean value of the observation part. As one method wants to see how to change the observation characteristics by rotating the original space, few deviation from the mean value will be interpret to have similar observation characteristics over all even if it has the differences of watching place by rotated space.

• 한국실내디자인학회논문집
• /
• 제18권5호
• /
• pp.128-136
• /
• 2009

This study analyzed and defines the property of visual perception throughout the revision of the observation time of the original space and the rotating space. The conclusions of this study are as fellows: First, based on the existing theory and experiment, the study obtained the basis which decides the sector data originating fixation-gaze after staring the specific sector over 300ms time. It will become the turning point hereafter for our research to fix the time in this way. Second, in analyzing the minute data, the study built a revision method of the observation time by analyzing the meanings and the reasons of the revision of the original data. Third, according to the difference of revision quantity, female testee have more increases in the amount of data than male testee from the original screen. On the other hand, the opposite tendency appears from the previous data. This shows there is a difference in the observation properly by sex. Last, we could grasp Information about the property of the observation time throughout eyeball fixations, and the revision and analysis of the 'controlled observation data'. These data can be used in design element arrangement of interior space, hereafter.

• 경영과학
• /
• 제19권2호
• /
• pp.155-168
• /
• 2002

In this paper, some efficient implementation techniques for the multifrontal method, which can be used to compute the Cholesky factor of a symmetric positive definite matrix, are presented. In order to use the cache effect in the cache-based computer architecture, a hybrid method for factorizing a frontal matrix is considered. This hybrid method uses the column Cholesky method and the submatrix Cholesky method alternatively. Experiments show that the hybrid method speeds up the performance of the supernodal multifrontal method by 5%～10%, and it is superior to the Cholesky method in some problems with dense columns or large frontal matrices.

• 한국방송∙미디어공학회:학술대회논문집
• /
• 한국방송공학회 2009년도 IWAIT
• /
• pp.103-107
• /
• 2009

This paper presents how to minimize the second-order cone programming problem occurring in the 3D reconstruction of multiple views. The $L_{\infty}$-norm minimization is done by a series of the minimization of the maximum infeasibility. Since the problem has many inequality constraints, we have to adopt methods of the interior point algorithm, in which the inequalities are sequentially approximated by log-barrier functions. An initial feasible solution is found easily by the construction of the problem. Actual computing is done by an iterative Newton-style update. When we apply the interior point method to the problem of reconstructing the structure and motion, every Newton update requires to solve a very large system of linear equations. We show that the sparse bundle-adjustment technique can be utilized in the same way during the Newton update, and therefore we obtain a very efficient computation.

• 한국디지털건축인테리어학회논문집
• /
• 제11권2호
• /
• pp.61-70
• /
• 2011

This study aims to establish the concept about a new approaching method dor remodeling in the planning step. also, this study sets up the way how to approach in a dimensional way by classifying the conceptual composition of the target housing as a method. The dimensional definition is as below. The one dimensional approach: the spot. the two dimensional approach: the line, the three dimensional approach: the apatial mass, the four dimensional approach: space + time, the n dimensional (multi-dimensional) approach: the space + time + emotion. The research findings are as follows : For the purpose of remodeling, the old housing should be viewed in the three dimensional shape and space. It is defined as multi-dimensional module method to design the shape and space of the target housing in a multi-dimensional point, considering the three dimensional space composition, the emotion of the user, the housing itself. and the time of the user.

• 센서학회지
• /
• 제26권3호
• /
• pp.214-222
• /
• 2017

In this study, the effects of internal heat treatment associated sintering temperatures were simulated by the Finite Element Method (FEM). The sintering mechanism of pulsed current activated sintering process (PCAS) is still unclear because of some unexplainable heat transfer phenomena in coupled multi-physical fields, as well as the difficulty in measuring the interior temperatures of metal powder. We have carried out simulation study to find out thermal distributions between graphite mold and Ruthenium powder prior to PCAS process. For PCAS process, heating rate was maintained at $100^{\circ}C/min$ the simulation indicates that the sintering temperature range was between $1000^{\circ}C$ to $1300^{\circ}C$ under 60 MPa. The heat transfer inside the Ruthenium sintered-body sample was modelled through the whole process in order to predict the minimum interior temperature. Thermal simulation shows that the interior temperature gradient decreased by graphite punch length and calculation results well agreed with the PCAS field test results.

• 한국멀티미디어학회논문지
• /
• 제13권6호
• /
• pp.825-832
• /
• 2010

This paper presents only a matching algorithm based on Delaunay triangulation and Parametrization from the extracted minutiae points. This method maps local neighborhood of points of two different point sets to unit-circle using topology information by Delaunay triangulation method from feature points of real fingerprint. Then, a linked convex polygon that includes an interior point is constructed as one-ring which is mapped to unit-circle using Parametrization that keep shape preserve. In local matching, each area of polygon in unit-circle is compared. If the difference of two areas are within tolerance, two polygons are consider to be matched and then translation, rotation and scaling factors for global matching are calculated.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
• /
• pp.327-333
• /
• 1998

A method for analysis of the free vibrations of the composite cylindrical shell with a longitudinal, interior rectangular plate is developed by using the receptance method. This method is based on the ratio of a deflection(or slope) response to a harmonic force(or moment) at an joint point. The natural frequencies of the combined shells calculated numerically. The results are compared with the experiment and a finite, element analysis results in order to validate the formulation. The effects of the location and thickness of the plate on the frequencies are also investigated.