• Transactions on Electrical and Electronic Materials
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• v.17 no.1
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• pp.46-49
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• 2016

A thin film transistor (TFT) has been fabricated using the amorphous 0.5 wt% Si doped zinc-tin-oxide (a-0.5 SZTO) with different electrodes made of either aluminium (Al) or titanium/aluminium(Ti/Al). Contact resistance and total channel resistance of a-0.5SZTO TFTs have been investigated and compared using the transmission line method (TLM). We measured the total resistance of 1.0×10² Ω/cm using Ti/Al electrodes. This result is due to Ti, which is a material known for its adhesion layer. We found that the Ti/Al electrode showed better contact characteristics between the channel and electrodes compared with that made of Al only. The former showed a less contact and total resistance. We achieved high performance of the TFTs characteristic, such as Vth of 2.6 V, field effect mobility of 20.1 cm² V⁻¹s⁻¹, S.S of 0.9 Vdecade⁻¹, and on/off current ratio of 9.7×10⁶ A. It was demonstrated that the Ti/Al electrodes improved performance of TFTs due to enhanced contact resistance.

• Tribology and Lubricants
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• v.31 no.3
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• pp.109-124
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• 2015

This paper presents a wear analysis procedure for the journal bearings on a stripped-down single-cylinder engine during start-up and coast-down by motoring. A journal bearing is in the mixed elastohydrodynamic (EHL) lubrication region when the shaft speed is less than the corresponding lift-off speed. Below the lift-off speed, a wear scar can form on bearing surfaces. In part 1 of this paper, we develop the appropriate formulations and the calculation procedure for the analysis. Specifically, we formulate an equation for modified film thickness in a journal bearing considering the additional wear volume. In order to obtain the modified specific wear rate induced by the modified Archard’s wear coefficient, we utilized the extended non-dimensional diagram for the specific wear rate, k, the fractional film defect coefficient, Ψ and the asperity load sharing factor, γ₂. This asperity load sharing factor is newly calculated by setting the Zhao-Maietta-Chang (ZMC) asperity contact pressure equation coupled with the central film thickness equation derived by using the ZMC asperity contact model equal to the modified central contact pressure derived by using the central (or maximum) contact pressure at the dry rough line-contact configuration. We can use the procedure introduced in this paper to determine the lifetime (or longterm) linear wear in radial journal bearings that is a result of repeated stop-start cycles.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.11
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• pp.1925-1929
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• 2007

This paper is studied on a novel Electric Safety Protection Device (ESPD) of high speed for incapable operation of Earth Leakage Circuit Breaker (ELB) and Molded_case Circuit Breaker (MCCB) using the low voltage distribution line. The major causes of electrical fire are classified to short circuit fault, overload fault, electric leakage and electric contact failure. The occurrence factor of the fire is electric arc or spark accompanied with electrical faults. Residual Current Protective Device (RCD), that is ELB and MCCB, of high sensitivity type used at low voltage wiring cuts off earth leakage and overload, but the RCD can't cut off electric arc or spark to be a major factor of electrical fire. As the RCDs which are applied low voltage distribution panel are prescribed to rated breaking time about 30[ms] (KS C 4613), the RCDs can't perceive to the periodic electric arc or spark of more short wavelength level. To be improved on such problem, this research development is proposed to a novel ESPD of high speed to trip of distribution line on electric arc or spark due to electrical fire. Some experimental results of the proposed ESPD are confirmed to the validity of the analytical results.

• East Asian Journal of Business Economics (EAJBE)
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• v.8 no.3
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• pp.15-24
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• 2020

Purpose - New technologies allow service providers to integrate all the customer information within and between contact channels so that they can offer individualized services. The availability of new mobile devices enables retailers to interact with customers through countless channels (Rigby, 2011). The objective of this research is to examine customers' attitudes toward O2O (on-line to off-line) services and their intention to use based on the Technology Acceptance Model (TAM). Research design, data, and methodology - Utilizing the TAM model, the mediating effect of the users' attitudes toward O2O services on the relationship among perceived ease of use, perceived usefulness, perceived risks and intention to use are to be investigated. Results - The result shows that the perceived ease of use, perceived usefulness, perceived risks have a significant effect on customers' attitudes toward O2O services. It is also revealed that the attitude toward O2O services has a mediating effect among perceived ease of use, perceived usefulness, perceived risks and intention to use. Conclusions - The boundary between on-line and off-line is eroding and various services based on the O2O platform are growing. The results of this study and managerial implications can be applied to O2O platform operators or enterprises planning to sharp on their competitiveness edge through offering variations of service channels.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.12
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• pp.1953-1958
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• 2012

The major causes of electrical fire are classified to short circuit fault, overload fault, electric leakage and electric contact failure. The occurrence factor of the fire is electric arc or spark accompanied with such electric faults, specially short circuit faults. Earth Leakage Circuit Breaker (ELB) and Molded_case Circuit Breaker (MCCB), that is, Residual Current Protective Devices (RCDs) used on low voltage distribution lines cut off earth leakage and overload, but the RCD can not cut off electric arc or spark to be a major factor of electrical fire. As the RCDs which are applied in low voltage distribution panel are prescribed to rated breaking time about 30ms(KS C 4613), the RCDs can't perceive to the periodic electric arc or spark of more short wavelength level. To improve such problem, this paper proposes a prevention apparatus using the line voltage drop of neutral wire and some semiconductor switching devices. Some experimental tests of the proposed apparatus confirm the validity of the analytical results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.207-215
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• 2011

This study was about the relation of 129 differently stressed male college students's on or off-line contact behavior to out-eating places. We researched the subjects's obesity degree such as body fat percentage, body mass index, stress condition, and contact behavior to out-eating places. Subjects's average age was 20, height 174.9cm. More stress they felt, heavier their body weight was and more obese. 37.1% of Strongly stressed group, 28.8% of medium and 25% of normal stressed group felt severe depression. As the result of pearson correlation, stress condition was positively related with body weight, obese degree, body mass index(BMI) and exercise time. Body weight was positively related with obeses degree, BMI, and the amount of smoking and drinks. Strongly stressed group used more internet to search the information about out-eating places, they had more experience to search the homepage of out-eating places than other groups significantly. Strongly stressed group cared more about the sanity of out-eating places where they ate. and they were interested in various experiences than other groups. Strongly stressed group felt the tasty was the most important satisfying factor significantly and visited the out-eating place that satisfied them again than other groups.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.6
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• pp.876-880
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• 2013

The major causes of electrical fire are classified to short circuit fault, overload fault, electric leakage and electric contact failure. The principal factor of the fire is electric arc or spark accompanied with such electric faults. Earth Leakage Circuit Breaker (ELB) and Molded_case Circuit Breaker (MCCB), that is, Residual Current Protective Devices (RCDs) used on low voltage distribution lines cut off earth leakage and overload, but the RCD can not cut off electric arc or spark to be a major factor of electrical fire. As the RCDs which are applied in low voltage distribution panel are prescribed to rated breaking time about 30[ms] (KS C 4613), the RCDs can't perceive to the periodic electric arc or spark of more short wavelength level. To improve such problems, this paper studies on an arc fault circuit interrupter (AFCI) using the distorted voltage wave in electric arc faults. The proposed voltage sensing type AFCI is an electrical fire prevention apparatus of new conception that operates a circuit breaker with sensing the instantaneous voltage drop of line voltage at electrical faults occurrence. The proposed AFCI is composed of control circuit topology using some semiconductor switching devices. Some experimental tests of the proposed AFCI confirm practicality and the validity of the analytical results.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.371-372
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• 2007

The major causes of electrical fire are classified to short circuit fault, overload fault, electric leakage and electric contact failure. The occurrence factor of the fire is electric arc or spark accompanied with electrical faults. Residual Current Protective Device (RCD), that is Earth Leakage Circuit Breaker(ELB) and Molded_case Circuit Breaker (MCB), of high sensitivity type used at low voltage wiring cuts off earth leakage and overload, but the RCD can't cut off electric arc or spark to be a major factor of electrical fire. As the RCDs which are applied low voltage distribution panel are prescribed to rated breaking time about 30[ms] (KS C 4613), the RCDs can't perceive to the periodic electric arc or spark of more short wavelength level. To be improved on such problem, this research development is proposed to a auxiliary control apparatus for RCD trip on electric arc or spark due to electrical fire. Some experimental results of the proposed apparatus is confirmed to the validity of the analytical results.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.543-543
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• 2013

Thin-film transistors (TFTs) based on oxide semiconductors have been regarded as promising alternatives for conventional amorphous and polycrystalline silicon TFTs. Oxide TFTs have several advantages, such as low temperature processing, transparency and high field-effect mobility. Lots of oxide semiconductors for example ZnO, SnO2, In2O3, InZnO, ZnSnO, and InGaZnO etc. have been researched. Particularly, zinc-tin oxide (ZTO) is suitable for channel layer of oxide TFTs having a high mobility that Sn in ZTO can improve the carrier transport by overlapping orbital. However, some issues related to the ZTO TFT electrical performance still remain to be resolved, such as obtaining good electrical contact between source/drain (S/D) electrodes and active channel layer. In this study, the bottom-gate type ZTO TFTs with staggered structure were prepared. Thin films of ZTO (40 nm thick) were deposited by DC magnetron sputtering and performed at room temperature in an Ar atmosphere with an oxygen partial pressure of 10%. After annealing the thin films of ZTO at $400^{\circ}C$ or an hour, Cu, Mo, ITO and Ti electrodes were used for the S/D electrodes. Cu, Mo, ITO and Ti (200 nm thick) were also deposited by DC magnetron sputtering at room temperature. The channel layer and S/D electrodes were defined using a lift-off process which resulted in a fixed width W of 100 ${\mu}m$ and channel length L varied from 10 to 50 ${\mu}m$. The TFT source/drain series resistance, the intrinsic mobility (${\mu}i$), and intrinsic threshold voltage (Vi) were extracted by transmission line method (TLM) using a series of TFTs with different channel lengths. And the performances of ZTO TFTs were measured by using HP 4145B semiconductor analyzer. The results showed that the Cu S/D electrodes had a high intrinsic field effect mobility and a low effective contact resistance compared to other electrodes such as Mo, ITO and Ti.

• Korean Security Journal
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• no.6
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• pp.47-65
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• 2003

In Korea, Private security companies has steadily grown and amounts to 2,051 places as of November 30, 2002. Private security in korea is carrying out firm name role assignment to have held the police and public peace environment change factors for a standard faithfully, and protects social a little property that is a basic purpose, and it is spare no efforts in loss prevention. In spite of numeral increase of private security companies, private security companies have many problem. Moreover, they mostly did not have any remarkable in-house expertises in their own business under tough conditions. Under the unfavorable circumstances including insufficient investment and education in private security guard, there have been actually little further studies on private security business in practices. So this study mainly focused on addressing the installation security business managed by authorized companies, which amount to 96%(1,963 companies) of total 2,051 domestic security companies. Furthermore, the study formulated and modeled a series of business procedures in private security companies. A series of business procedures of private security companies can be modeled as follows : Setting of a business scope and aim market ${\Rightarrow}$ Marketing, Contact from customers(On-line or Off-line) ${\Rightarrow}$ Diagnosis of security target ${\Rightarrow}$ Submission of security operational plan ${\Rightarrow}$ Estimation of security operational plan ${\cdot}$ decision ${\Rightarrow}$ Contract ${\Rightarrow}$ Employment, selection of security guards ${\Rightarrow}$ Nomination of security guard instructors ${\Rightarrow}$ Education & training of security guards ${\Rightarrow}$ subscribe to insurance of damage liability ${\Rightarrow}$ Commitment and placement of security guards ${\Rightarrow}$ Establishment and preparation of security planning ${\Rightarrow}$ Field management and procurement of relevant security service.