• 한국초전도ㆍ저온공학회논문지
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• 제8권2호
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• pp.17-19
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• 2006

A novel clock distribution technique for pipelined-RSFQ logics using variable Bias Currents of JTLs as delay-medium is newly proposed. RSFQ logics consist of several logic gates or blocks connected in a pipeline structure. And each block has variable delay difference. In the structure, this clock distribution method generates a set of clock signals for each logic blocks with suitable corresponding delays. These delays, in the order of few to tens of pS, can be adjusted through controlling bias current of JTL of delay medium. While delays with resistor value and JJ size are fixed at fabrication stage, delay through bias current can be controlled externally, and thus, is heavily investigated for its range as well as correct operation within current margin. Possible ways of a standard delay library with modular structure are sought for further modularizing Pipelined-RSFQ applications. Simulations and verifications are done through WRSpice with Hypres 3-um process parameters.

• Ocean and Polar Research
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• 제36권2호
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• pp.165-177
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• 2014

In an effort to investigate the structure and variability of the coastal current in the East Sea, a moored ADCP observation was conducted off Uljin from late May to mid-October 2006. Owing to the transition of season from summer to autumn, the features of the current and wind can be divided into two parts. Until mid-August (Part-I), a southward flow is dominant at all depths with a mean alongshore velocity of 4.2~8.9 cm/s but northward winds are not strong enough to reverse the near-surface current. During Part-II, a strong northward current occurs frequently in the upper layer but winds are predominantly southward including two typhoons that have deep-reaching influence. Profile of mean velocity has three layers with a northward velocity embedded at 12~28 m depth. The near-surface current of Part-II significantly coheres with winds at 4-8 day periods with a phase lag of about 12 hours. The modal structure of the current obtained by EOF analysis is: (1) Mode-1, having 83.6% of total variance, represents the current in the same direction at all depths corresponding to the southward North Korean Cold Current (NKCC). (2) Mode-2 (11.7%) reveals a two-layer structure that can be explained by the northward East Korean Warm Current (EKWC) in the upper layer and NKCC in the lower. (3) Mode-3 (2.6%) has three layers, in which the EKWC is reversed near the surface by opposing winds. This mode is particularly similar to the mean velocity profile of Part-II.

• 한국정밀공학회지
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• 제17권10호
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• pp.162-169
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• 2000

A Direct Drive Valve(DDV) hydraulic actuation system which is commonly used as an aircraft's control surface driving actuator has multi-loop control structure to ensure its safety operation. However, because of not perfect matching of one self channel characteristics with the others, the servo valve driving current of each channel can be widely different. Therefore, the long-time use of DDV actuator without any correction of these channel current offsets will cause the problem of performance or life expectancy degradation due to unwanted heats in the linear motor. A current equalization loop structure which can minimizes current offsets between channels is introduced and designed. The performance of the current equalization loop is investigated and verified through the analytic and experimental ways.

• Transactions on Electrical and Electronic Materials
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• 제4권6호
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• pp.32-37
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• 2003

In this paper, the trap characteristics of thin silicon oxides is investigated in the ULSI implementation with nano structure transistors. The stress and transient currents associated with the on and off time of applied voltage were used to measure the distribution of high voltage stress induced traps in thin silicon oxide films. The stress and transient currents were due to the charging and discharging of traps generated by high stress voltage in the silicon oxides. The transient current was caused by the tunnel charging and discharging of the stress generated traps nearby two interfaces. The stress induced leakage current will affect data retention in electrically erasable programmable read only memories. The oxide current for the thickness dependence of stress current, transient current, and stress induced leakage currents has been measured in oxides with thicknesses between 113.4nm and 814nm, which have the gate area 10$\^$-3/ $\textrm{cm}^2$. The stress induced leakage currents will affect data retention, and the stress current and transient current is used to estimate to fundamental limitations on oxide thicknesses.

• 한국표면공학회지
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• 제27권5호
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• pp.285-291
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• 1994

The effects of pulse current parameters on the composition and the microstructure of Pd-Ni alloy electrodeposits were studied. The cathode current efficiency of p.c. electrolysis conditions decreased with increasing both mean and peak current density and was lower than those under D.C. electrolysis condition. Palladium content of Pd-Ni alloy increased with increasing both peak current density and on-time, while it decreased with increasing mean current density and duty cycle. The preferred orientation of Pd-Ni alloys changed with increasing mean current density in the sequence of (111)+(110).(100) or (110)longrightarrow(111)longrightarrow(100) or random distribution of crystal structure. The surface morphology of Pd-Ni alloy changed mainly according to the mean current density and was related to the preferred orientation.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.281-285
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• 2008

Corrosion of metallic structures arises when an electric current flows from the metal into the electrolyte such as soil and water. The potential difference across the metal-electrolyte interface, the driving force for the corrosion current, can emerge due to a variety of temperature, pH, humidity and resistivity etc.. With respect to a given structure, a stray current is to be defined as a current flowing on a structure that is not part of the intended electrical circuit. Stray currents are caused by other cathodic protection installations, grounding systems and welding posts, referred to as steady state stray currents. But most often traction systems like railroads and tramlines are responsible for large dynamic stray currents. This type of stray current is generally results from the leakage of return currents from large DC traction systems that are grounded or have a bad earth-insulated return path. This paper investigates the reports, which is made for protecting the electrical corrosion by the DC traction stray current before the construction period.

• 한국항만학회지
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• 제8권2호
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• pp.67-77
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• 1994

A time-domain numerical model is developed to examine the performance of a wave energy focusing structure in combined waves and a current. With the current assumed to be slow and the structure fully submerged, the wave-current interaction problem is reduced to a wave scattering problem in a uniform current. The diffraction of incident waves around a narrow berm is considered. The shape of the berm is defined by a parabola, imitating that of an optical reflector. The energy focus is achieved by reflecting the incident waves through a predetermined focal point. Through the numerical simulations, the numerical model is shown to be effective in modeling the wave-current interaction problem, and the current speed and direction are shown to affect significantly the location, amplitude and sharpness of the focus.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.34-36
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• 2008

Highly efficient red and green phosphorescent devices comprising a simple bilayer structure are reported. The driving voltage to reach $1000\;cd/m^2$ is 4.5 V in $Bebq_2:\;Ir(piq)_3$ red phosphorescent device. Current and power efficiency values of 9.66 cd/A and 6.90 lm/W in this bi-layered simple structure PHOLEDs are obtained, respectively. While in $Bepp_2:Ir(ppy)_3$ green phosphorescent device, the operating voltage value of 3.3V and current and power efficiencies of 37.89 cd/A and 35.02 lm/W to obtain a luminance of $1000\;cd/m^2$ are noticed, respectively.

• 한국표면공학회지
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• 제35권4호
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• pp.232-240
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• 2002

The composition and the microstructure of the Zn-Cr alloys electroplated in chloride bath with EDTA were studied according to electrolysis conditions. The cathode current efficiency decreased with increasing both Cr/(Cr+Zn) ratio and current density. The Cr content of the alloy deposits increased with Cr/(Cr+Zn) ratio and current density The phase structure of Zn-Cr alloy deposits changed from η-Zn through η-Zn+${\gamma}$'-ZnCr to ${\gamma}$'-ZnCr with increasing Cr content of alloys. The surface morphology of Zn-Cr alloy deposits changed from fine needle shaped crystallites through the mixed structure of needle-shaped and granular one to the colony structure with fine granular crystallites according to the change of phase structure

• Corrosion Science and Technology
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• 제11권6호
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• pp.242-246
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• 2012

This measurement represents the effectiveness of sacrificial anode cathodic protection (SACP) system in a coastal bridge structure. To verify the cathodic protection (CP) effect, the monitoring sensor (DMS-100) that could measure potential, corrosion rate, current, concrete resistivity, and temperature was embedded. The measurement conducted for three years after CP system was installed. Specifically, due to the fact that fresh water and sea water was repeated in the bridge structure, this bridge structure presented special CP behavior. Measurement factors were CP potential, CP current, concrete resistivity, and depolarization potential. In addition, visual inspection was also carried out. As a result of current and depolarization measurement, CP system was well activated in most piers.