• 한국통신학회논문지
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• 제36권12C호
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• pp.753-758
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• 2011

The constant modulus algorithm (CMA) widely used in blind equalization applications minimizes the averaged power of constant modulus error (CME) defined as the difference between an instant output power and a constant modulus. In this paper, a decision feedback version of the linear blind algorithm based on maximization of the zero-error probability for CME is proposed. The Gaussian kernel of the maximum zero-error criterion is analyzed to have the property to cut out excessive CMEs that may be induced from severely distorted channel characteristics. Decision feedback approach to the maximum zero-error criterion for CME is developed based on the characteristic that the Gaussian kernel suppresses the outliers and this prevents error propagation to some extent. Compared to the linear algorithm based on maximum zero-error probability for CME in the simulation of blind equalization environments, the proposed decision feedback version has superior performance enhancement particularly in cases of severe channel distortions.

• 한국농촌건축학회논문집
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• 제16권4호
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• pp.25-34
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• 2014

The 21century is the year of clean renewable alternative energy crisis, in this study the idea of construction of zero energy and environmentally friendly rural village is to be studied. So the purpose of this study is to verify the design guide-line of zero energy and sustainable design of rural village. The results of this study is to be follow: 1) the design elements and factors for construction of zero energy and environmentally friendly rural village is derived 2) also the guide-line for construction of zero energy and environmentally friendly rural village is derived.

• Journal of Magnetics
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• 제6권3호
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• pp.77-79
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• 2001

The semi-empirical superposition model has been applied to calculate the zero field splitting parameters of $Mn^{2+}$ion in $LiTaO_3$ single crystal, assuming that $Mn^{2+}$ion occupies one of two possible sites: $Li^{l+} \;or\; Ta^{5+}$ site, respectively. The 2nd-order axial zero field splitting parameters are $958\times10^{-4}cm^{-1}\; at\; Li^{1+}$ site and $193\times 10^{-4}cm^{-1} \;at\; Ta^{5+}$ site for $Mn^{2+}$ions. The 4th-order zero field splitting parameters at $Li^{l+} \;and\; Ta^{5+}$ sites are also determined. These calculated zero field splitting parameters are very important to determine the substitutional sites of doped impurity ions in $LiTaO_3$ crystal.

• Journal of Electrical Engineering and Technology
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• 제13권1호
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• pp.256-262
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• 2018

This study introduces a novel Soft Switching (SS) Pulse Width Modulated (PWM) AC-DC boost converter. In the proposed converter, the main switch is turned on with Zero Voltage Transition (ZVT) and turned off with Zero Current Transition (ZCT). The main diode is turned on with Zero Voltage Switching (ZVS) and turned off with Zero Current Switching (ZCS). The auxiliary switch is turned on and off with ZCS. All auxiliary semiconductor devices are turned on and off with SS. There is no extra current or voltage stress on the main semiconductor devices. The majority of switching energies are transferred to the output by auxiliary transformer. Thus, the current stress of auxiliary switch is significantly reduced. Besides, the proposed converter has simple structure and ease of control due to common ground. The theoretical analysis of the proposed converter is verified by a prototype with 100 kHz switching frequency and 500 W output power. Furthermore, the efficiency of the proposed converter is 98.9% at nominal output power.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제2B권4호
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• pp.183-190
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• 2002

This paper presents an improved Zero Voltage/Zero Current Switching (ZVZCS) commutation cell with minimum additional components, which provides soft switching at both turn-on and turn-off of main and auxiliary switches as well as diodes in a PWM DC/DC converter. The proposed soft-switching technique is suitable for not only minority, but also majority carrier semiconductor devices. The auxiliary switch of the proposed ZVZCS commutation cell is in parallel with the main switch, and therefore, the main switch and the diode are free of currentstress. The operation principles of the proposed ZVZCS commutation cell are theoretically analyzed using the PWM boost converter topology as an example. The validity of the PWM boost converter topology with the proposed ZVZCS commutation cell is verified through theoretical analysis, simulation and experimental results.

• Journal of Advanced Marine Engineering and Technology
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• 제7권1호
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• pp.34-39
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• 1983

Development of modern internal combustion engine requires more precise indicator. In the case of strain gage-strain tube type indicator, thermal expansion of the indicator's fixed part makes zero-shift in spite of water cooling. Therefore, the authors analyzed the cause of zero-shift phenomenon on strain gage-strain tube type indicator and proposed a new device to compensate the zero-shift of indicator by electrical method without detoriorating the dynamic charcteristic. As the results, we found that the zero-shift is varied linearlly according to temperature variation of the indicator's fixed part and appling a new device, we can improve the zero-shift of indicator about 0.63% (0.63 kg/$cm^2$) of full scale, though we got 10% of it without the device at the cylinder head operating temperature (c.a. $200^{\circ}C$).

• 전기전자학회논문지
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• 제22권4호
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• pp.1238-1241
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• 2018

본 논문에서는 zero-skipping을 적용한 MNIST 분류 CNN을 구현했다. CNN의 activation에서 0이 30~40% 나오고, 0은 MAC 연산에 영향을 끼치지 않기 때문에 0을 branch를 통해 skip하게 되면 성능 향상을 시킬 수 있다. 그러나 컨볼루션 레이어에서는 branch를 통해 skip하게 되면 성능 하락이 발생한다. 그에 따라 컨볼루션 레이어에서는 연산의 영향을 미치지 않는 NOP을 주어 연산을 skip하고 풀리 커넥티드 레이어에서는 branch를 통해 skip했다. 기존의 CNN보다 약 1.5배의 성능 향상을 확인했다.

• Journal of Power Electronics
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• 제19권2호
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• pp.560-568
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• 2019

This paper studies the inherent relationship between currents and zero-sequence components. Then a precise algorithm is proposed to calculate the injected zero-sequence component to control the DC-Link neutral-point voltage balance, which can result in a more efficient and flexible neutral point voltage balance with a desirable performance. In addition, it is shown that carried-based PWM with the calculated zero-sequence component scheme can be equivalent to space-vector pulse-width modulation (SVPWM). Based on the proposed method, the optimal zero-sequence component of the feasible modulation indices is analyzed. In addition, the unbalanced load limitation of the DC-Link neutral-point voltage balance control is also revealed. Simulation and experimental results are shown to verify the validity and practicality of the proposed algorithm.

• Korean Journal of Mathematics
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• 제29권1호
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• pp.13-24
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• 2021

For a finite commutative ring R with identity 1 ≠ 0, the zero divisor graph ��(R) is a simple connected graph having vertex set as the set of nonzero zero divisors of R, where two vertices x and y are adjacent if and only if xy = 0. We find the signless Laplacian spectrum of the zero divisor graphs ��(ℤn) for various values of n. Also, we find signless Laplacian spectrum of ��(ℤn) for n = pz, z ≥ 2, in terms of signless Laplacian spectrum of its components and zeros of the characteristic polynomial of an auxiliary matrix. Further, we characterise n for which zero divisor graph ��(ℤn) are signless Laplacian integral.

• 한국공간구조학회논문집
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• 제21권1호
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• pp.61-70
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• 2021

This paper describes a novel zero-stress member selecting method for sizing optimization of truss structures. When a sizing optimization method with static constraints is implemented, the member stresses are affected sensitively with changing the variables. However, because some truss members are unaffected by specific loading cases, zero-stress states are experienced by the elements. The zero-stress members could affect the computational cost and time of sizing optimization processes. Feature selection approaches can be then used to eliminate the zero-stress member from the whole variables prior to the process of optimization. Several numerical truss examples are tested using the proposed methods.