• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.9
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• pp.687-692
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• 1998

Silicon doped $Al_{0.32}Ga_{0.68}As$ were growth by molecular beam epitaxy. Electroreflectance(ER) spectra of the $E_1$ transition of Schottky barrier Au/n-$Al_{0.32}Ga_{0.68}As$ have been measured at various modulation voltage($V_{ac}$) and dc bias voltage($V_{bias}$). from the $E_1$peak, band gap energy of the $Al_{0.32}Ga_{0.68}As$ is 1.883 eV which corresponds to an Al composition of 32%. As modulation voltage($V_{bias}$) is changed, a line shape at the $E_1$transition does not change, but its amplitude varies linearly. The amplitude of $E_1$signal decrease with increasing the forward dc bias voltage($V_{bias}$), but the line shape does not change. It suggests that the low field theory rather than Franz-Keldysh oscillation is Required to interpret spectra. Also, spectra at the $E_1$transition were broadened with increasing the reverse dc bias voltage($V_{bias}$) which suggests the presence of Field-induced broadening.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.2
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• pp.104-110
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• 2008

In this paper we proposed a new source-drain structure for N-type MOSFET which can suppress the output resistance reduction of a device in saturation region due to soft break down leakage at high drain voltage when the gate is biased around relatively low voltage. When a device is generally used as a switch at high gate bias the current level is very important for the operation. but in electronic circuit like an amplifier we should mainly consider the output resistance for the stable voltage gain and the operation at low gate bias. Hence with T-SUPREM simulator we designed devices that operate at low gate bias and high gate bias respectively without a extra photo mask layer and ion-implantation steps. As a result the soft break down leakage due to impact ionization is reduced remarkably and the output resistance increases about 3 times in the device that operates at the low gate bias. Also it is expected that electronic circuit designers can easily design a circuit using the offered N-type MOSFET device with the better output resistance.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.6
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• pp.49-56
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• 2000

Due to the rapid increase of long-distance transportation, particular attentions have been paid to truck tires, especially to their dynamic characteristics. In this research, experimental modal analysis on two kinds of light-duty truck tires, i.e., radial tire and bias tire, are performed by using GRFP(global rational fraction polynomial) method to investigate differences of the dynamic behavior of the two tires. The test results have shown that the modal frequencies of bias tire are much higher than the corresponding values of radial tire with a similar mode shape, which is in accordance with the fact that the radial rigidity of bias tire is higher than that of radial tire. And most of the modal decay rates of bias tire are larger than those of radial tire within the scope of this experiment. In the frequency domain range of test, the bias tire has extra modes, which do not occur in the radial tire. This difference is based on the fact that the circumferential rigidity of the bias tire is quire low whereas that of radial tire is so high that the frequencies of the corresponding modes are out of the frequency range of test.

• Journal of the Korean institute of surface engineering
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• v.52 no.6
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• pp.342-349
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• 2019

Titanium nitride(TiN) thin films have been deposited on PEN(Polyethylene naphthalate) substrate by reactive RF(13.56 MHz) magnetron sputtering in a 25% N₂/Ar mixed gas atmosphere. The pulsed DC bias voltage of -50V on substrates was applied with a frequency of 350 kHz, and duty ratio of 40%(1.1 ㎲). The effects of pulsed DC substrate bias voltage on the crystallinity, color, electrical properties of TiN_x films have been investigated using XRD, SEM, XPS and measurement of the electrical properties such as electrical conductivity, carrier concentration, mobility. The deposition rates of TiN_x films was decreased with application of the pulsed DC substrate bias voltage. The TiN_x films deposited without and with pulsed bias of -50V to substrate exhibits gray and gold colors, respectively. XPS depth profiling revealed that the introduction of the substrate bias voltage resulted in decreasing oxygen concentration in TiN_x films, and increasing the electrical conductivities, carrier concentration, and mobility to about 10 times, 5 times, and 2 times degree, respectively.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.1231-1240
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• 2021

A shift in perspective from standard finance to behavioral finance has taken place in the past two decades that explains how cognition and emotions are associated with financial decision making. This study aims to investigate the influence of various psychological factors on investment decision-making. The psychological factors that are investigated are differentiated into two aspects, cognitive and emotional aspects. From the cognitive aspect, we examine the influence of anchoring, representativeness, loss aversion, overconfidence, and optimism biases on investor decisions. Meanwhile, from the emotional aspect, the influence of herding behavior on investment decisions is analyzed. A quantitative approach is used based on a survey method and a snowball sampling that result in 165 questionnaires from individual investors in Yogyakarta. Further, we use the One-Sample t-test in testing all hypotheses. The research findings show that all of the variables, anchoring bias, representativeness bias, loss aversion bias, overconfidence bias, optimism bias, and herding behavior have a significant effect on investment decisions. This result emphasizes the influence of behavioral factors on investor's decisions. It contributes to the existing literature in understanding the dynamics of investor's behaviors and enhance the ability of investors in making more informed decision by reducing all potential biases.

• Journal of the Korean institute of surface engineering
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• v.54 no.3
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• pp.133-138
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• 2021

Ternary Ti-X-N coatings, where X = Al, Si, Cr, O, etc., have been widely used for machining tools and cutting tools such as inserts, end-mills, and etc. Ti-Al-N-O coatings were deposited onto silicon wafer and WC-Co substrates by a cathodic arc evaporation (CAE) technique at various negative substrate bias voltages. In this study, the influence of substrate bias voltages during deposition on the microstructure and mechanical properties of Ti-Al-N-O coatings were systematically investigated to optimize the CAE deposition condition. Based on results from various analyses, the Ti-Al-N-O coatings prepared at substrate bias voltage of -80 V in the process exhibited excellent mechanical properties with a higher compressive residual stress. The Ti-Al-N-O (-80 V) coating exhibited the highest hardness around 30 GPa and elastic modulus around 303 GPa. The improvement of mechanical properties with optimized bias voltage of -80 V can be explained with the diminution of macroparticles, film densification and residual stress induced by ion bombardment effect. However, the increasing bias voltage above -80 V caused reduction in film deposition rate in the Ti-Al-N-O coatings due to re-sputtering and ion bombardment phenomenon.

• Journal of IKEEE
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• v.27 no.4
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• pp.418-424
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• 2023

In this study, we examined the effects of annealing on electrical characteristics of double-gated silicon nanosheet (SiNS) feedback field effect transistors (FBFETs). When bias stresses were applied for 1000 s, the double-gated SiNS FBFETs were more affected by positive bias stresses than negative bias stresses regardless of the channel mode owing to the increase of interface traps caused by electrons in the inversion layers. After annealing at 300 ℃ for 10 mins, the devices were completely recovered to their original properties, and the characteristics did not change anymore when bias stresses were applied again for 1000 s.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.5
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• pp.33-44
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• 2023

Entrepreneurial self-efficacy is an important variable that explains people's attitudes and behaviors toward start-ups. In this study, we focused on individual psychological characteristics variables such as luck in belief and positive cognitive bias that affect entrepreneurial self-efficacy. Among these variables, we paid particular attention to luck in belief. The belief that business success depends on luck is widespread, but scientific verification about it has not been much. The reason for the academic indifference is that luck is a kind of superstition, related to precognition or extrasensory perception, and randomly caused by the external environment. The study of luck began in earnest as a measure to measure luck as an individual characteristic variable such as personality was developed. The purpose of this study is to examine the existing studies on luck in belief and to examine the effect of this luck in belief on positive cognitive bias and entrepreneurial self-efficacy through empirical analysis. For empirical analysis, this study conducted an on-line survey of 400 ordinary people and conducted a structural equation model analysis using AMOS 21.0 to verify the hypothesis. As a result of hypothesis testing, all hypotheses that luck in belief would have a positive effect on positive cognitive bias(self-enhancement bias, illusion of control bias, unrealism optimistic bias) were adopted. The hypothesis that positive cognitive bias(self-enhancement bias, illusion of control bias, unrealistic optimism bias) will have a positive effect on entrepreneurial self-efficacy was also adopted. Additional analysis was conducted to examine the mediating role of positive cognitive bias in the relationship between luck in belief and entrepreneurial self-efficacy, which showed that 'luck in belief→positive cognitive bias →entrepreneurial self-efficacy' were statistically significant. Through this, we confirmed the mediating effect of positive cognitive bias in the relationship between luck in belief and entrepreneurial self-efficacy. In the conclusion, the implications and limitations of the study were presented based on the results of this study.

• Journal of The Korean Association For Science Education
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• v.36 no.6
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• pp.935-946
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• 2016

This study aims to explore cognitive biases relating the core competences of science and instructional strategy in reducing the level of cognitive biases. The literature review method was used to explore cognitive biases and science education experts discussed the relevance of cognitive biases to science education. Twenty nine cognitive biases were categorized into five groups (limiting rational causal inference, limiting diverse information search, limiting self-regulated learning, limiting self-directed decision making, and category-limited thinking). The cognitive biases in limiting rational causal inference group are teleological thinking, availability heuristic, illusory correlation, and clustering illusion. The cognitive biases in limiting diverse information search group are selective perception, experimenter bias, confirmation bias, mere thought effect, attentional bias, belief bias, pragmatic fallacy, functional fixedness, and framing effect. The cognitive biases in limiting self-regulated learning group are overconfidence bias, better-than-average bias, planning fallacy, fundamental attribution error, Dunning-Kruger effect, hindsight bias, and blind-spot bias. The cognitive biases in limiting self-directed decision-making group are acquiescence effect, bandwagon effect, group-think, appeal to authority bias, and information bias. Lastly, the cognitive biases in category-limited thinking group are psychological essentialism, stereotyping, anthropomorphism, and outgroup homogeneity bias. The instructional strategy to reduce the level of cognitive biases is disused based on the psychological characters of cognitive biases reviewed in this study and related science education methods.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.317-320
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• 2000

In this paper, a 0.5W, 2GHz high-efficiency class A power amplifier using the dynamic bias control is proposed. First of all, the drain bias control amplifier is analyzed theoretically and designed with commercial devices. Simulation results show that the proposed amplifier has a significant improved efficiency, compared to fixed bias power amplifier.