• Current Photovoltaic Research
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• v.8 no.3
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• pp.102-106
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• 2020

In this paper, the effect of MoSe₂ on the contact resistance (R_C) of the transparent conducting oxide (TCO) and Mo junction in the scribed P2 region of the Cu(In,Ga)Se₂ (CIGS) solar module was analyzed. The CIGS/Mo junction becomes ohmic-contact by MoSe₂, so the formation of the MoSe₂ layer is essential. However, the CIGS solar module has a TCO/MoSe₂/Mo junction in the P2 region due to structural differences from the cell. The contact resistance (R_C) of the P2 region was calculated using the transmission line method, and MoSe₂ was confirmed to increase R_C of the TCO/Mo junction. B doped ZnO (BZO) was used as TCO, and when BZO/MoSe₂ junction was formed, conduction band offset (CBO) of 0.6 eV was generated due to the difference in their electron affinities. It is expected that this CBO acts as a carrier transport barrier that disturbs the flow of current, resulting in increased R_C. In order to reduce the R_C caused by CBO, MoSe₂ must be made thin in a CIGS solar module.

• Journal of Sensor Science and Technology
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• v.25 no.5
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• pp.349-353
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• 2016

Recently, research on bolometer-type uncooled infrared image sensor which is made for industrial applications has been increasing. In general, it is difficult to calibrate fixed pattern noise (FPN) of bolometer array. In this paper, average-current calibration algorithm is presented for reducing bolometer resistance offset. A resistor which is produced by standard CMOS process, on the average, has a deviation. We compensate for deviation of each resistor using average-current calibration algorithm. The proposed algorithm has been implemented by a chip which is consisted of a bolometer pixel array, average current generators, current-to-voltage converters (IVCs), a digital-to-analog converter (DAC), and analog-to-digital converters (ADCs). These bolometer-resistor array and readout circuit were designed and manufactured by $0.35{\mu}m$ standard CMOS process.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.10
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• pp.65-72
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• 2000

In this paper, we propose an efficient technique to minimize the input offset of a dynamic latch comparator. We analyzed offset due to charge injection mismatching and unwanted positive feedback during sampling phase. The last one was only considered in the previous works. Based on the analysis, we proposed a modified dynamic latch with initialization switch. The proposed circuit was simulated using 0.65${\mu}m$ CMOS process parameter with 5v supply. The simulation results showed that the input offset is less than 5mV ant 200MHz sampling frequency and the input offset is improved about 80% compared with previous work in $5k{\Omega}$ input resistance.

• Korean Journal of Exercise Nutrition
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• v.25 no.2
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• pp.8-14
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• 2021

[Purpose] The purpose of this study was to investigate the effects of a high-fat high-sucrose (HFHS) diet on previously reported adaptations of cardiac morphological and contractile properties to resistance training. [Methods] Twelve-week-old rats participated in 12-weeks of resistance exercise training and consumed an HFHS diet. Echocardiography and skinned cardiac muscle fiber bundle testing were performed to determine the structural and mechanical adaptations. [Results] Compared to chow-fed sedentary animals, both HFHS- and chow-fed resistance-trained animals had thicker left ventricular walls. Isolated trabecular fiber bundles from chow-fed resistance-trained animals had greater force output, shortening velocities, and calcium sensitivities than those of chow-fed sedentary controls. However, trabeculae from the HFHS resistance-trained animals had greater force output but no change in unloaded shortening velocity or calcium sensitivity than those of the chow-fed sedentary group animals. [Conclusion] Resistance exercise training led to positive structural and mechanical adaptations of the heart, which were partly offset by the HFHS diet.

• Journal of Sensor Science and Technology
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• v.26 no.5
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• pp.331-337
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• 2017

A readout circuit for a tactile sensor pad based on force sensing resistors was proposed, which was composed of an analog signal conditioning circuit and a digital circuit with a microcontroller. The conventional signal conditioning circuit has a dc offset voltage in the output signal, which results from the reference voltage applied to the FSR devices. The offset voltage reduces the dynamic range of the circuit and makes it difficult to operate the circuit under a low voltage power supply. In the proposed signal conditioning circuit, the dc offset voltage was removed completely. The microcontroller with A/D converter and D/A converter was used to enlarge the measurement range of pressure. For this, the microcontroller adjusts the FSR reference voltage according to the resistance magnitude of FSR under pressure. The operation of the proposed readout circuit which was connected to a tactile sensor pad with $5{\times}10$ FSR array was verified experimentally. The experimental results show the proposed readout circuit has the wider measurement range of pressure than the conventional circuit. The proposed circuit is suitable for low voltage and low power applications.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.5
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• pp.711-720
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• 1994

A distance relaying algorithm for detecting faults at power transmission line is presented in this paper. The algorithm is based on differential equation from relaton between voltage and current, which is composed of lumped resistance and inductance. During the fault transient state,the voltage and current signals are severely distorted due to the exponentially decaying DC offset and high frequency components, In spite of using small data, the presented integral method to evaluate R and L from voltage and current has high performance against these harmonics including DC offset. Therefore, the presented algorithm can be implemented with only a low order anti-aliasing analog filter and dosen't need any digital filter to remove specific components.

• Structural Engineering and Mechanics
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• v.29 no.3
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• pp.301-310
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• 2008

Applications of fracture mechanics in the strength analysis of ceramic materials have been lately studied by many researchers. Various test specimens have been proposed in order to investigate the fracture resistance of cracked bodies under mixed mode conditions. Double Cleavage Drilled Compression (DCDC) specimen, with a hole offset from the centerline is a configuration that is frequently used in subcritical crack growth studies of ceramics and glasses. This specimen exhibits a strong crack path stability that is due to the strongly negative T-stress term. In this paper the maximum tensile stress (MTS) criterion is employed for investigating theoretically the initiation of brittle fracture in the DCDC specimen under mixed mode conditions. It is shown that the T-stress has a significant influence on the predicted fracture load and the crack initiation angle. The theoretical results suggest that brittle fracture in the DCDC specimen is controlled by a combination of the singular stresses (characterized by KI and KII) and the non-singular stress term, T-stress.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.8
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• pp.142-147
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• 2009

Spinal fixation systems provide surgical versatility, but the complexity of their design reduces their strength and fatigue resistance. There is no published data on the mechanical properties of such screws. Screws were assembled according to a vertebrectomy model for destructive mechanical testing. A group of two assemblies was tested in static compression. One group was applied to surface a grit blasting method and another group was applied to surface a bead blasting method. Modes of failure, yield, and ultimate strength, yield stiffness, and cycles to failure were determined for six assembles. Static compression 2% offset yield load ranges was from 327 to 419N. Fatigue loads were determined two levels, 37.5% and 50% of the average load from static compression ultimate load. An assembly of bead blasting treatment only achieved 5 million cycles at 37.5% level in compression bending.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.7 s.166
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• pp.1147-1154
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• 1999

The objective of this paper is to evaluate the fracture resistance characteristics of SA508 CL.1a carbon steel, and their associated welds manufactured for primary coolant piping system of nuclear power plants. The effect of various parameters such as pipe size, welding method and chemical composition on the material properties were discussed. Test results showed that the offset of pipe size on tincture toughness was negligible, while the effect of welding method on fracture toughness was significant. In addition, Fracture toughness for carbon steel was influenced by silicon contents due to the different steel refining processes.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.11-16
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• 1998

In this paper, simultaneous estimation of rotor speed and time constant for a voltage source inverter (VSI) fed induction motor drive are disccussed. The theory is based on the Model Reference Adaptive System (MRAS). The identifier executes Simultaneous rotor speed and time constant so that vector control of the induction may be achieved in the rotor-flux oriented reference frame. Furthermore, to eliminate the offset error caused by the change in the stator resistance, a fuzzy resistance regulator is also designed which operates in parallel with the rotor speed and time constant identifier