• Journal of Mechanical Science and Technology
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• 제16권11호
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• pp.1435-1439
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• 2002

This paper presents a form of the cohesive surface separation potential, which can produce potential curves by varying a single dimensionless parameter. Results show that a partial modification of Xu and Needleman's (1994) cohesive surface separation potential makes it possible to present the other potential corves as a special case as long as the normal separation is concerned. The proposed potential may describe interfacial debonding-crack initiation and growth-character of materials and, through numerical simulation, provide an insight for the effect of different cohesive surface separation potentials on the interfacial debonding.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.122-124
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• 2008

Interior permanent magnet synchronous motor(IPMSM) has become a popular choice in electric vehicle applications, due to their excellent power to weight ratio. In order to maximize the efficiency in such applications, this paper proposes the Adaptive-FNIS(Fuzzy Neural Network Inference System). The controllable electrical loss which consists of the copper loss and the iron loss can be minimized by the optimal d-axis current $i_d$. This paper considers the parameter variation about the motor operation. The operating characteristics controlled by efficiency optimization control are examined in detail.

• 진공이야기
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• 제3권4호
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• pp.19-23
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• 2016

Angle resolved photoemission spectroscopy (ARPES) is a powerful technique which can directly visualize the electronic structure of solid in detail including many-body interaction information. However, ARPES has a certain limitation in applying control parameters such as doping or pressure, which helps to dig out the clue to understand the desired phenomena or the target system. During ARPES experiment, the control parameter is the temperature only. Other parameters especially electric- and magnetic- field cannot be applied. Recently introduced surface-electron doping technique highlights new avenue to overcome such limitation. In this article, starting from introducing basic concepts of ARPES and its current status, the power of new technique will be demonstrated when it is combined to ARPES by introducing recent results on iron based superconductors.

• 한국염색가공학회지
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• 제6권2호
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• pp.40-46
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• 1994

In order to study the properties of cochineal color, variation of uv, visible spectra by pH, dyeing properties on the silk in several dyeing conditions and thermodynamic parameter were investigated. Cochineal colors had an unusual to pH, especially had instability in alkali condition. An increase in the dyeing temperature and in time resulted in an increase in the dye content of silk fibers. Concentration of cochineal color in the silk fiber was related to pH and the maximum exhaustion of cochineal colors showed at about pH 3. The value of apparent diffusion coefficients and standard affinities of dyeing increased with the increase of dyeing temperature. The standard heats of dyeing(ΔH°), variation of entropy(ΔS°) and activation energy(E/sub act/) were caculated to be -1.72kcal/mo1, -3.77cal/mo1ㆍdeg and 1.26kcal/mo1, respectively. Silk fabrics were dyed bright red by tin chloride, reddish purple by copper sulfate, and bluish gray by iron sulfate, respectively. Lightfastness of silk fabrics mordanted by metal ion was weak.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.339-342
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• 2001

In this paper, the characteristics of the shielded inductive superconducting fault current limiter(FCL) were simulated and analyzed to search for the parameter to determine FCL operation, Fault current limiting operation can be executed as resistive or inductive type, which is determined by iron-core radius and the number of the primary coil turns. It was considered through this paper that the operation of each was compared and examined about the merit of each mode.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.53-55
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• 2008

In high speed applications, the slotless permanent magnet(PM) motors appear an attractive solution, being almost insensitive to magneto-motive force harmonics and to pulse width modulation(PWM) current ripple and exhibiting lower stator iron losses and rotor losses (significant with square wave current control). So, this paper deals with methods for design of permanent magnet synchronous motor/generator.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.395-398
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• 2008

Interior permanent magnet synchronous motor(IPMSM) has become a popular choice in electric vehicle applications, due to their excellent power to weight ratio. In order to maximize the efficiency in such applications, this paper proposes the FNN(Fuzzy Neural-Network)-Pl controller. The controllable electrical loss which consists of the copper loss and the iron loss can be minimized by the error back propagation algorithm(EBPA). This paper considers the parameter variation about the motor operation. The operating characteristics controlled by efficiency optimization control are examined in detail.

• Journal of Power Electronics
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• 제9권2호
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• pp.173-179
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• 2009

This paper proposes a new three-phase diode rectifier system with a sinusoidal input current at unity power factor and a regulated and isolated output voltage at low level. The inherent natural wave-shaping capability of the reduced kVA polyphase transformer together with an active current wave-shaping technique results in a significant reduction of input and output filter requirements associated with switching ripple and EMI. The operation principles are described along with a design example and a comparative evaluation. Experimental results on a 1.5kW prototype are provided to validate the proposed concept.

• 한국전기전자재료학회논문지
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• 제14권3호
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• pp.257-262
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• 2001

Single crystalline films of La doped YIG(yttrium iron garnet) were grown by the liquid phase epitaxy. The lattice constants of films obtained by DCD(double crystalline diffractometer) measurement increased with increasing La contents in films. In particular, lattice constants of films grown wiht Y/La=20 solution were nearly same as those of GGG (gadolinium gallium garnet) substrate. The saturation magnetization measured with VSM (vibrating sample magnetometer) was about 1750Gauss which is the same as that of pure YIG irrespective of La contents in films. FMR(ferromagnetic resonance) linewidth of La doped YIG was smaller than that of pure YIG. Since appropriate La doping decreases the lattice mismatch between film and substrate, the FMR linewidth was Y/La=20 in this experiment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
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• pp.73-75
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• 1999

The performance of a SRM in terms of torque and power factor depends on the two-axis inductances (Ld and Lq) and iron loss of the machine. Finite element method has been used to determine these parameters for a motor with segmented rotor structure. Fock and Hart Method has been conducted to compare to verify the accuracy of proposed analysis method.