• Korean Chemical Engineering Research
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• 제56권4호
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• pp.536-541
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• 2018

Excess molar volumes ($V_m^E$) of binary mixtures of 1-propanol or 2-propanol (1) + cyclohexane or n-hexane (2) were measured with V-shaped dilatometer at 303.15 K. The $V_m^E$ data for these mixtures varied as: 2-propanol > 1-propanol and were higher for cyclohexane than n-hexane for both propanol systems. The experimental data were correlated with Redlich-Kister polynomial. The $V_m^E$ data were interpreted qualitatively as well as quantitatively in terms of Flory-Treszczanowicz-Benson model and Prigogine-Flory-Patterson theory. Both models correctly described the sign and shape of $V_m^E$ vs $x_1$ curves. The values calculated by both the models agree well with the experimental data.

• 수산해양기술연구
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• 제32권1호
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• pp.1-6
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• 1996

Towing tension of the model nets were determined by the load cell(O~20kg, 20DBBP) in front of W$T_mA$ = 1.57 . $V^1.86$ (unit: kg, mlsec) $T_mB$= 1.58 . $V^1.90$ 2. The towing tension of the full scale net was almost coincided with the results obtained by the model experiment. The towing tension(T) can be expressed as a function of the towing veJocity(V) as T=479$V^1.75$(unit: kg, k't)

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권1호
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• pp.96-99
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• 2014

In high-${\kappa}$/metal-gate (HK/MG) metal-oxide-semiconductor field-effect transistors (MOSFETs) at 45-nm and below, the metal-gate material consists of a number of grains with different grain orientations. Thus, Monte Carlo (MC) simulation of the threshold voltage ($V_{TH}$) variation caused by the workfunction variation (WFV) using a limited number of samples (i.e., approximately a few hundreds of samples) would be misleading. It is ideal to run the MC simulation using a statistically significant number of samples (>~$10^6$); however, it is expensive in terms of the computing requirement for reasonably estimating the WFV-induced $V_{TH}$ variation in the HK/MG MOSFETs. In this work, a simple matrix model is suggested to implement a computing-inexpensive approach to estimate the WFV-induced $V_{TH}$ variation. The suggested model has been verified by experimental data, and the amount of WFV-induced $V_{TH}$ variation, as well as the $V_{TH}$ lowering is revealed.

• 조명전기설비학회논문지
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• 제20권6호
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• pp.63-68
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• 2006

22,900[V] 전압에서 발생하는 감전사고를 살펴보기 위하여 최근의 감전사고에 대한 통계자료를 분석하였다. 22,900[V] 전압의 감전사고의 메커니즘을 실증하기 위해서 분석 결과에 근거하여 모의 감전사고 실험을 수행하였다. 실험에서는 여러 가지 상황에서 모의된 감전사고의 위험성을 정량적으로 분석하기 위하여 인체모형에 흐르는 전류를 측정하였다. 실험결과 감전 상황과 관계없이 일단 감전사고가 발생하면 인체에 치명적인 것으로 밝혀졌다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2008년도 정기 학술대회
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• pp.524-531
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• 2008

A method for representing detailed design information of steel bridge member is proposed on the basis of the IFC model. As a first step, bridge related entities in the IFC-BRIDGE V2 and their functions are analyzed. In addition, design documents of steel bridge members are analyzed to extract information items that are not handled in the IFC-BRIDGE V2. It is recommended that several entities in the IFC-BRIDGE V2, such as ifcBridgeFibre, IfcBridgeReferenceLine, and IfcBridgeSection, should be properly relocated. In addition, IfcBridgeStiffener, IfcBridgeJointSystem, IfcBridgeDiaphragm, and IfcBridgeShearConnector are added as subtypes of IfcBridgeElementComponent for representing the stiffener, joint system, diaphragm, and shear connector, respectively. The added new entities inherit all attributes of IfcProduct which is linked with other resources: geometric representation, placement, material information, and so on. Thus, it is considered that a proposed in-depth IFC-BRIDGE model can be used more widely.

• 한국초전도ㆍ저온공학회논문지
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• 제5권3호
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• pp.48-51
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• 2003

HTS power transmission cable is expected to transport large electric power with a compact size. We are developing a 3-core, 22.9 kV, 50 MVA class HTS power cable, and each core consists of a conductor and shield wound with Bi-2223 tapes, electrical insulation with laminated polypropylene paper (LPP) impregnated with liquid nitrogen. This paper describes the design and experimental results of the model cable for the 22.9 kV, 50 MVA class HTS power transmission cable. The model cable was used the SUS tapes instead of HTS tapes because of testing the electrical characteristics only. The model cable was 1.3 m long and electrical insulation thickness was 4.5 mm. The model cable was evaluated the partial discharge (PD), AC and Impulse withstand voltage in liquid nitrogen. The AC and Impulse withstands voltage and PD inception stress was satisfied with the standard of Korea Electric Power Corporation (KEPCO) in the test results. The 3-core 22.9 kV, 50 MVA class HTS power cable has been designed and manufactured based on these experimental results.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권9호
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• pp.538-544
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• 2004

This paper presents the interruption capability of serial-hybrid type GCB (gas circuit breaker) compared with that of puffer type. First a puffer type model interrupter which has the stroke length of 80 mm has been designed and manufactured. And also, a serial-hybrid type interrupter which has the same design parameters as the puffer type interrupter except the serially arranged thermal-expansion chamber and puffer cylinder has been fabricated. Using a simplified synthetic test facility, the critical interruption capabilities of the two GCBs have been estimated. The critical di/dt, the critical dV/dt of ITRV (initial transient recovery voltage) and the minimum arcing time of the puffer type model GCB were 10.7 A/${\mu}\textrm{s}$, 5.5 kV/${\mu}\textrm{s}$, and 15.0 ms respectively. In the case of serial-hybrid type model GCB, each of the values was 16.6A/${\mu}\textrm{s}$, 11.5 kV/${\mu}\textrm{s}$ and 13.0 ms. As a conclusion of this work, it has been quantitatively confirmed that the hybrid type interrupter can obtain the sufficient interruption capability at the operating force which is so low that puffer type interrupter has not the interruption capability.

• Geomechanics and Engineering
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• 제15권4호
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• pp.987-995
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• 2018

In this study, a relationship between small-strain shear modulus ($G_{max}$) and overconsolidation ratio (OCR) based on shear wave velocity ($V_S$) measurement was established to identify the stress history of centrifuge model ground. A centrifuge test was conducted in various centrifugal acceleration levels including loading and unloading sequences to cause various stress histories on centrifuge model ground. The $V_S$ and vertical effective stress were measured at each level of acceleration. Then, a sensitivity analysis was conducted using testing data to ensure the suitability of OCR function for the tested cohesionless soils and found that OCR can be estimated based on $V_S$ measurements irrespective of normally-consolidated or overconsolidated loading conditions. Finally, the developed $G_{max}$-OCR relationship was applied to centrifuge models constructed and tested under various induced stress-history conditions. Through a series of tests, it was concluded that the induced stress history on centrifuge model by compaction, g-level variation, and past overburden load can be analysed quantitatively, and it is convinced that the OCR evaluation technique will contribute to better interpret the centrifuge test results.

• Transactions on Control, Automation and Systems Engineering
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• 제2권4호
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• pp.268-273
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• 2000

Plasma models are crucial to equipment design and process optimization. A radial basis function network(RBFN) in con-junction with statistical experimental design has been used to model a process plasma. A 2$^4$ full factorial experiment was employed to characterized a hemispherical inductively coupled plasma(HICP) in characterizing HICP, the factors that were varied in the design include source power, pressure, position of shuck holder, and Cl$_2$ flow rate. Using a Langmuir probe, plasma attributes were collected, which include typical electron density, electron temperature. and plasma potential as well as their spatial uniformity. Root mean-squared prediction errors of RBEN are 0.409(10(sup)12/㎤), 0.277(eV), and 0.699(V), for electron density, electron temperature, and Plasma potential, respectively. For spatial uniformity data, they are 2.623(10(sup)12/㎤), 5.704(eV) and 3.481(V), for electron density, electron temperature, and plasma potential, respectively. Comparisons with generalized regression neural network(GRNN) revealed an improved prediction accuracy of RBFN as well as a comparable performance between GRNN and statistical response surface model. Both RBEN and GRNN, however, experienced difficulties in generalizing training data with smaller standard deviation.

• 한국전자파학회논문지
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• 제13권1호
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• pp.74-79
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• 2002

본 논문에서는 Ka-band 위성 중계기용 국부 발진기에 사용하게 될 전압제어 발진기의 EM(Engineering Model)을 비선형 방법으로 설계하였다. 전압제어 발진기의 위상잡음을 개선하기 위하여 공진기로 사용되는 유전체 공진기와 결합하는 마이크로스트립 라인을 high impedance inverter로 구현함으로써 공진회로의 quality factor를 우수하게 유지하여 능동소자에 전달되도록 하였다. 개발된 전압제어 발진기는 0~12 V의 제어전압으로 9.7965~9.8032 GHz의 튜닝범위를 가지며 공급전력은 8V, 17mA를 필요로 한다. 제작된 전압제어 발진기의 위상잡음은 -96.51 dBc/Hz ⓐ10 KHz와 -116.5 dBc/Hz ⓐ100 KHz의 특성을 나타내며 출력전력은 7.33 dBm을 얻었다.