• Journal of the Korean Society of Safety
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• v.35 no.2
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• pp.76-83
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• 2020

This study examined the effects of perceptual differences of safety leadership between managers and workers on workers' safety attitudes and behavior in two construction sites. In addition, the mediating role of safety attitude between safety leadership and safety behavior across discrepancy level of safety leadership. This study was conducted on two first-tier construction companies within the 100th place in 2019. Two companies were similar in size(100 - 150 billion won) and process from the basement frame finishing stage to start of the ground structure of apartment. In A Site, 40 managers and 73 workers, 42 managers and 77 workers in B site participated the survey on managers' safety leadership, and workers' safety attitude and behavior. The results showed that there was no significant difference between the safety leadership scores assessed by the manager and workers at site B. However, the safety leadership scores assessed by the managers were significantly higher than that by the workers at site A. The workers' safety attitudes and behaviors at site B were higher than those of workers at site A. Moreover, Site B was significantly higher in the effects of safety leadership on safety behavior than Site A. At site B, safety leadership had a significant influence on safety behavior even after controlling the safety attitude of workers. At site A, safety leadership had no significant effect on safety behavior after controlling safety attitude. These findings suggest that there is managers' self-serving bias on safety leadership in site A and that this bias of leadership can negatively affect workers' safety attitude and behaviors. In addition, it can be seen that if the self-serving bias on safety leadership occurs, the manager's safety leadership has less influence on workers' safety behavior.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.4
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• pp.145-153
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• 2014

This study examined the linkage between positive cognitive bias and entrepreneurial intention. Self-enhancement, unrealistic optimism, and illusion of control have been collectively referred as positive cognitive bias. We examined the effects of positive cognitive bias on attitudes toward success and failure. And we also examined the effect of attitudes toward success and failure on entrepreneurial intension. This study investigated these relationships using 240 high school students. The result of analysis indicated that the self-enhancement bias and unrealistic optimism bias had positive effects on attitude toward failure, but it had not any effect on attitude toward success. The illusion of control bias has positive effects on attitude toward success, but it had not any effect on attitude toward failure. The attitudes toward success and failure had positive effect on entrepreneurial intension. Then results of this study suggests that the cognitive biases showed a role of antecedents of attitudes toward success and failure. Finally, this study concluded with a discussion of the implications of the research findings and directions for future research.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3865-3869
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• 2013

Background: Cigarette per day (CPD) use is a key smoking behaviour indicator. It reflects smoking intensity which is directly proportional to the occurrence of tobacco induced cancers. Self reported CPD assessment in surveys may suffer from digit bias and under reporting. Estimates from such surveys could influence the policy decision for tobacco control efforts. In this context, this study aimed at identifying underlying factors of digit bias and its implications for Global Adult Tobacco Surveillance. Materials or Methods: Daily manufactured cigarette users CPD frequencies from Global Adult Tobacco Survey (GATS) - India data were analyzed. Adapted Whipple Index was estimated to assess digit bias and data quality of reported CPD frequency. Digit bias was quantified by considering reporting of '0' or '5' as the terminal digits in the CPD frequency. The factors influencing it were identified by bivariate and logistic regression analysis. Results: The mean and mode of CPD frequency was 6.7 and 10 respectively. Around 14.5%, 15.1% and 15.2% of daily smokers had reported their CPD frequency as 2, 5 and 10 respectively. Modified Whipple index was estimated to be 226.3 indicating poor data quality. Digit bias was observed in 38% of the daily smokers. Heavy smoking, urban residence, North, South, North- East region of India, less than primary, secondary or higher educated and fourth asset index quintile group were significantly associated with digit bias. Discussion: The present study highlighted poor quality of CPD frequency data in the GATS-India survey and need for its improvement. Modeling of digit preference and smoothing of the CPD frequency data is required to improve quality of data. Marketing of 10 cigarette sticks per pack may influence CPD frequency reporting, but this needs further examination. Exploring alternative methods to reduce digit bias in cross sectional surveys should be given priority.

• Journal of the Korean Vacuum Society
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• v.12 no.S1
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• pp.36-39
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• 2003

Field-domain dynamics and current self-oscillations are theoretically studied in quantum-well (QW) negative-effective-mass (NEM) $p^{+}pp^{+}$ diodes when the electric field is applied along the direction of the well. The origin of current self-oscillations is the formation and traveling of electric-field domains in the p-base. We have accurately considered the scattering contributions from carrier-impurity, carrier-acoustic phonon, and carrier-optic phonon. It's indicated that, both the applied bias and the doping concentration largely influence the current patterns and self-oscillating frequencies, which lie in the THz range for the NEM $p^{+}pp^{+}$ diode with a submicrometer p-base. The complicated field-domain dynamics is presented with the applied bias as the controlling parameter.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.3
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• pp.492-498
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• 2003

In this paper, We analyze the optimum bias conditions of cascode coupled microwave mixer for maximum conversion gain mixer. Microwave self-oscillating mixer by two GaAs MESFET cascode coupled, to upper GaAs MESFET operating as a oscillator with high Q dielectric resonator and the lower GaAs MESFET operated as a mixer with low noise and high conversion characteristics. As a result of experiments, cascode coupled microwave self oscillating mixer according to optimun bias shows an 5.92 dBm oscillating power, -132.0dBc/Hz @ 100KHz at 5.15GHz and 3dB conversion loss.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.4
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• pp.384-393
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• 2013

In this paper, a design of planar microwave bias-tee using lumped elements was presented. The bias-tee is composed of 2 blocks; DC block and RF choke. For this design of the bias-tee, a wideband capacitor was used for DC block. For a RF choke, a series connection of inductors which have different SRFs is used for a RF choke. In the RF choke, a series connection of resistor and capacitor was added in shunt to eliminate a loss from a series resonance. The designed bias-tee was implemented by using 1608 SMT chip components. The fabricated bias-tee was measured using Anritsu 3680K fixture which enables to remove an effect of a connector. The fabricated bias-tee presented -15 dB of return loss and -1.5 dB insertion loss at 10 MHz~18 GHz.

• Korean Journal of Materials Research
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• v.4 no.1
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• pp.9-23
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• 1994

Epitaxial $CoSi_2$ layer has been grown on NaCl(100) substrate at low deposition temperature($200^{\circ}C$) by multitarget bias cosputter deposition(MBCD). The phase sequence and crystallinity of deposited silicide as a function of deposition temperature and substrate bias voltage were studied by X-ray diffraction(XRD) and transmission electron microscopy(TEM) analysis. Crystalline Si was grown at $200^{\circ}C$ by metal induced crystallization(M1C) and self bias effect. In addition to, the MIC was analyzed both theoretically and experimentally. The observed phase sequence was $Co_2Si \to CoSi \to Cosi_2$ and was in good agreement with that predicted by effective heat of formation rule. The phase sequence, the CoSi(l11) preferred orientation, and the crystallinity had stronger dependence on the substrate bias voltage than the deposition temperature due to the collisional cascade mixing, the in-situ cleaning, and the increase in the number of nucleation sites by ion bombardment of growing surface. Grain growth induced by ion bombardment was observed with increasing substrate bias voltage at $200^{\circ}C$ and was interpreted with ion bombardment dissociation model. The parameters of $E_{Ar}\;and \alpha(V_s)$ were chosen to properly quantify the ion bombardment effect on the variation in crystallinty at $200^{\circ}C$ with increasing substrate bias voltage using Langmuir probe.

• Asian Oncology Nursing
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• v.12 no.4
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• pp.257-266
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• 2012

Purpose: The purpose of this study was to evaluate the effectiveness of patient education interventions on distress, self-care knowledge and self-care behavior in cancer patients. Methods: A total of 1,102 studies were retrieved from 6 electronic databases in Korea. From these studies, 18 studies met the inclusion criteria with a total of 850 participants. Two authors independently assessed the methodological quality by Cochrane's Risk of Bias and Methodological Items for Non Randomized Studies. The data were analyzed by the RevMan 5.1 program of Cochrane library. Results: Overall effect size of education interventions on anxiety was -2.12 (95% CI:-3.90, -0.34) (p<.001). The effects on self-care knowledge and self care behavior were -1.08 (95% CI:-1.73, -0.43) (p=.001), and -1.41 (95% CI:-2.13, -0.68) (p<.001), respectively. Publication bias was detected as evaluated by funnel plot, but the fail-safe number was moderate. Conclusion: This study suggests that patient education interventions can relieve anxiety and self-care. Further randomized controlled trials studies are needed to evaluate the effects of patient education intervention on depression.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.108-111
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• 2003

Currently, molecular devices are reported utilizing active self-assembled monolayers containing the nitro group as the active component, which has active redox centers[1]. We confirm the electrical properties of 4,4-di(ethynylphenyl)-2'-nitro-1-benzenethiolate. To deposit the SAM layer onto gold electrode, we transfer the prefabricated Au(111) substrates into a 1mM self-assembly molecules in THF solution. Au(111) substrates were prepared by ion beam sputtering method of gold onto the silicon wafer. As a result, we measured current-voltage curve using ultra high vacuum scanning tunneling microscopy (UHV STM), I-V curve also clearly shows several current peaks between the negative bias region (-0.3958V) and the positive bias region (0.4658V), respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.466-468
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• 2012

Amorphous InGaZnO (${\alpha}$-IGZO) thin-film transistors (TFTs) are are very promising due to their potential use in thin film electronics and display drivers [1]. However, the stability of AOS-TFTs under the various stresses has been issued for the practical AOSs applications [2]. Up to now, many researchers have studied to understand the sub-gap density of states (DOS) as the root cause of instability [3]. Nomura et al. reported that these deep defects are located in the surface layer of the ${\alpha}$-IGZO channel [4]. Also, Kim et al. reported that the interfacial traps can be affected by different RF-power during RF magnetron sputtering process [5]. It is well known that these trap states can influence on the performances and stabilities of ${\alpha}$-IGZO TFTs. Nevertheless, it has not been reported how these defect states are created during conventional RF magnetron sputtering. In general, during conventional RF magnetron sputtering process, negative oxygen ions (NOI) can be generated by electron attachment in oxygen atom near target surface and accelerated up to few hundreds eV by self-bias of RF magnetron sputter; the high energy bombardment of NOIs generates bulk defects in oxide thin films [6-10] and can change the defect states of ${\alpha}$-IGZO thin film. In this paper, we have confirmed that the NOIs accelerated by the self-bias were one of the dominant causes of instability in ${\alpha}$-IGZO TFTs when the channel layer was deposited by conventional RF magnetron sputtering system. Finally, we will introduce our novel technology named as Magnetic Field Shielded Sputtering (MFSS) process [9-10] to eliminate the NOI bombardment effects and present how much to be improved the instability of ${\alpha}$-IGZO TFTs by this new deposition method.