• 한국전자파학회논문지
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• 제24권12호
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• pp.1148-1157
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• 2013

수동형 UHF RFID 시스템에서 태그의 최대 인식 거리는 태그 칩과 안테나 사이의 임피던스 정합과 리더의 프로토콜 파라미터 설정에 따라 직접적인 영향을 받는다. 하지만 칩 임피던스 산출 방법과 프로토콜 파라미터가 최대 인식 거리에 미치는 영향에 대한 연구는 전무한 실정이다. 따라서 본 논문에서는 기존 방법(데이터 시트와 전용 RFID 테스터를 이용)과 제안된 방법(상용 리더를 이용)으로 칩의 임피던스를 산출한 후 이 값으로 태그를 제작해 인식 거리를 비교함으로써, 인식 거리를 극대화하는 칩 임피던스 산출 방법에 대한 비교분석을 하였다. 제안된 방법으로 산출된 임피던스에 공액 정합된 태그가 상용리더를 이용한 인식 거리 측정 실험에서 기존 방법과 비교하여 최대 73 % 인식 거리의 개선을 보였다.

• 한국자동차공학회논문집
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• 제21권3호
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• pp.105-112
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• 2013

In this paper, EV (Electric Vehicle) and ICE (Internal Combustion Engine) vehicle simulators are developed to compare maximum driving range of EV and ICE vehicle according to different driving patterns. And, simulations are performed for fourteen constant velocity cases (20, 30, 40, ${\ldots}$, 150 km/h) and four different driving cycles. From the simulation results of constant velocity, it is found that the decreasing rate of maximum driving range for EV is larger than the one for ICE as both the vehicle velocity and the driving power increase. It is because the battery efficiency of EV decreases as both the velocity and the driving power increase, whereas the engine and transmission efficiencies of ICE vehicle increase. From the results of four driving cycle simulation, the maximum driving range of EV is shown to decrease by 50% if the average driving power of driving cycle increases from 10 to 20kW. It is because the battery efficiency decreases as the driving power increases. In contrast, the maximum driving range of ICE vehicle also increases as the average driving power of driving cycle increases. It is because the engine and transmission efficiencies also increase as the driving power increases.

• 대한방사선기술학회지:방사선기술과학
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• 제41권1호
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• pp.25-31
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• 2018

This study aimed to evaluate the range of maximum TE that could measure T2 relaxation time accurately by setting diverse maximum TE with using contrast medium phantoms. Contrast medium phantoms ranging from low to high concentrations were made by using Gadoteridol. The relaxation time and relaxation rate were compared and evaluated by conducting T2 mapping by using reference data based on various TEs and data obtained from different maximum TEs. It was found that accurate T2 relaxation time could be expressed only when the maximum TE over a certain range was used in the section with long T2 relaxation time, such as the low concentration section of saline or gadolinium contrast medium. Therefore, the maximum TE shall be longer than the T2 relation time for accurately maturing the T2 relaxation of a certain tissue or a substance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 춘계학술대회 논문집 에너지변화시스템부문
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• pp.103-105
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• 2009

This paper presents the maximum-power control simulation for PMA-SynRM. For maximum power, the maximum torque / current control method is conducted in constant-torque range and flux-weakening control method is conducted in constant-power range. For considering the nonlinear characteristics of inductance, machine constant is determined by FEM. Finally, experiment is conducted to calculate the efficiency.

• Journal of Animal Science and Technology
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• 제60권5호
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• pp.13.1-13.7
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• 2018

Background: The objective of this study was to underline that litter size as a key trait of sows needs new parameters to be evaluated and to target an individual optimum. Large individual variation in litter size affects both production and piglet's survival and health negatively. Therefore, two new traits were suggested and analyzed. Two data sets on 5509 purebred German Landrace sows and 3926 Large White and crossing sows including at least two parental generations and at least five parities were subjected to variance components analysis. Results: The new traits for evaluating litter size were derived from the individual numbers of total born piglets (TBP) per parity: In most cases, sows reach their maximum litter size in their fourth parity. Therefore, data from at least five parities were included. The first observable maximum and minimum of TBP, and the individual variation expressed by the range were targeted. Maximum of TBP being an observable trait in pig breeding and management yielded clearly higher heritability estimates ($h^2{\sim}0.3$) than those estimates predominantly reported so far. Maximum TBP gets closer to the genetic capacity for litter size than other litter traits. Minimum of TBP is positively correlated with the range of TBP ($r_p=0.48$, $r_g$ > 0.6). The correlation between maximum of TBP and its individually reached frequency was negative in both data sets ($r_p=-0.28$ and - 0.22, respectively). Estimated heritability coefficients for the range of TBP comprised a span of $h^2=0.06$ to 0.10. Conclusion: An optimum both for maximum and range of total born piglets in selecting sows is a way contributing to homogenous litters in order to improving the animal-related conditions both for piglets' welfare and economic management in pig.

• 설비공학논문집
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• 제22권3호
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• pp.123-129
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• 2010

The district heating users can be generally classified into two groups such as apartments and buildings. In consideration that the time zone of the maximum heat load for apartments is different from those of buildings during a day, the maximum heat supply range is presented. In case of the investigated area, the maximum heat supply is occurred at the ratio between apartments and buildings that is 65%：35%. Thus the heat supply range is increased as much as 15% if the time zone when the maximum heat load is occurred is considered.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.183-186
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• 2002

The paper is proposed intantaneous torque control of IPMSM for drive of wide speed range. The control scheme is based on the mathematical model of the motor and is applicable to the constant torque and field weakening operations The scheme allows the motor to be driven with maximum torque per ampere (MTPA) characteristic below base speed and it maintains the maximum voltage limit of the motor wide field weakening and the motor current limit under all conditions of operation accurately. For each control mode. a condition that determines the optimal d-axis current $i_d$ for maximum torque operation is derived. The proposed control algorithm is applied to PMSM drive system for drive of wide speed range, the operating characteristics controlled by maximum torque control are examined in detail by simulation.

• 조명전기설비학회논문지
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• 제24권9호
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• pp.26-35
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• 2010

The maximum output torque developed by the machine is dependent on the allowable current rating and maximum voltage that the inverter can supply to the machine. Therefore, to use the inverter capacity fully, it is desirable to use the control scheme considering the voltage and current limit condition, which can yield the maximum torque per ampere over the entire speed range. This controller is controlled speed and current using hybrid PI(HBPI) controller and estimation of speed using ANN. Also, this paper is proposed maximum torque control of induction motor using slip angular speed and current condition at widely speed range. The performance of the proposed induction motor drive with maximum torque control using HBPI controller is verified by analysis results at dynamic operation conditions.

• 대한수학회보
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• 제55권5호
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• pp.1397-1404
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• 2018

For a connected graph G, an r-maximum edge-coloring is an edge-coloring f defined on E(G) such that at every vertex v with $d_G(v){\geq}r$ exactly r incident edges to v receive the maximum color. The r-maximum index $x^{\prime}_r(G)$ is the least number of required colors to have an r-maximum edge coloring of G. In this paper, we show how the r-maximum index is affected by adding an edge or a vertex. As a main result, we show that for each $r{\geq}3$ the r-maximum index function over the graphs admitting an r-maximum edge-coloring is unbounded and the range is the set of natural numbers. In other words, for each $r{\geq}3$ and $k{\geq}1$ there is a family of graphs G(r, k) with $x^{\prime}_r(G(r,k))=k$. Also, we construct a family of graphs not admitting an r-maximum edge-coloring with arbitrary maximum degrees: for any fixed $r{\geq}3$, there is an infinite family of graphs ${\mathcal{F}}_r=\{G_k:k{\geq}r+1\}$, where for each $k{\geq}r+1$ there is no r-maximum edge-coloring of $G_k$ and ${\Delta}(G_k)=k$.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제17권4호
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• pp.267-278
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• 2013

We consider zero range processes with density dependent jump rates g given by $g=g(n,k)=g_1(n)g_2(k/n)$ with $g_1(x)=x^{-\alpha}$ and $$g_2(x)=\{^{x^{-\alpha}\;if\;a&lt;x}_{Mx^{-\alpha}\;if\;x{\leq}a}$$. (0.1) In this case, with 1/2 < a < 1 and ${\alpha}$ > 0, we show that non-complete condensation occurs with maximum cluster size an. More precisely, for any ${\epsilon}$ > 0, there exists $M^*$ > 0 such that, for any 0 < M ${\leq}M^*$, the maximum cluster size is between (a - ${\epsilon}$)n and (a + ${\epsilon}$)n for large n. This provides a simple example of non-complete condensation under perturbation of rates which are deep in the range of perfect condensation (e.g. ${\alpha}$ >> 1) and supports the instability of the condensation transition.