• Journal of Applied Reliability
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• v.17 no.2
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• pp.122-128
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• 2017

Purpose: To investigate the corrosion inhibition effect of the natural spearmint oil extracted from Mentha Spicata plants on 304 stainless steel in different concentrations of hydrochloric acid. Method: The anti-corrosive effect has been investigated in 0.5m, 1m and 2m HCl using weight loss test and electrochemical polarization method as a function of inhibitor concentration and immersion time in strong chloride environment. The surface morphology was analysed by scanning electron microscopy (SEM). Results: The corrosion rate of steel decreased and inhibition efficiency increased with the increase in inhibitor concentration. Microscopic evaluation revealed significant corrosion in the specimens immersed in uninhibited conditions. Potentiodynamic polarization test results showed an increase in corrosion potential (Ecorr) and decrease in corrosion current (icorr) value with increasing concentration of inhibitor. Conclusions: Immersion of steel in higher concentration of inhibitor resulted in greater surface coverage value and hence lesser number of surface corrosion sites/pores were formed; thus lowering the corrosion rate.

• Fire Science and Engineering
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• v.25 no.2
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• pp.95-100
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• 2011

The ultimate purpose of this study is to improve the irrational system related to flame retardant coating performance test of field flame retardant coating articles and to secure the reliability of flame retardant coating through rational flame retardant coating test. To achieve this, the analysis was conducted on the interior finishing materials used in the interior fields and the trends of recent field flame retardant coating, based on the results of flame retardant coating performance test of field flame retardant coating articles which the first-line fire stations have recently conducted. And I attempted to present the methods of field flame retardant coating performance test suitable to current realities and the ways of improvement for securing reliability by analyzing the problems with the methods and procedures of field flame retardant coating articles and the registration system of flame retardant coating business.

• The Journal of Industrial Distribution & Business
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• v.11 no.1
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• pp.49-57
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• 2020

Purpose : The purpose of this study is to examine the effect of the attributes of mobile shopping apps on the purchase intention of fashion products in the steadily growing mobile commerce market and analyze the mediation effect of shopping flow. Research design, data and methodology : In this study, a survey was conducted on users in their 20s to 50s who had experience of fashion products via mobile shopping apps. The questionnaire was analyzed on the final 507. The research issues were verified using Frequency analysis, Exploratory factor analysis, Reliability analysis, Confirmatory factor analysis, and Structural equation model. Results : Among the attributes of mobile shopping apps, reliability, enjoyment and ease of use were found to have a significant impact on shopping flow and fashion product purchase intention, while shopping flow had a significant impact on fashion product purchase intention. Product diversity and usefulness of shopping apps didn't show a significant effect. After examining the mediation effect, reliability, enjoyment, and ease of use were shown to have indirect effects by showing partial mediation effects. Conclusions : Studies show that consumers are not putting much emphasis on how diverse a product line is available and how useful a mobile shopping app is when they shop for fashion products on mobile devices. Factors that affect consumers' purchase intention are reliability, enjoyment and ease of use of shopping apps. These results shows that it is important to provide reliable information about fashion products, provide reliability to customers by setting up means for safe transactions, and provide a wider variety of services and information to make using the mobile shopping app enjoyable. In addition, there is a need to make it easy to find a fashion product that consumers like and make it easy to purchase when consumers find out fashion products that they like, and to configure how to use the app easily. Consequently, consumers become immersed in shopping which is also able to improve consumers' purchase intention on fashion products when a reliable, enjoyable and easy to use mobile shopping app is provided.

• Journal of Internet Computing and Services
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• v.7 no.6
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• pp.175-183
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• 2006

An ad-hoc network is a group of mobile nodes acting as routers. The of hoc node has a precondition of mobility, allowing path to be easily disconnected when transmitting data, thereby increasing network overhead. However, most of hoc routing protocols set up the path based only on the number of hops without considering other practical factors. Here we consider a path with the least substantial number of transmission (SNT) from source to destination based on reliabilities of links. This includes retransmissions due to unreliable links. In this paper, an efficient ad-hoc link reliability based routing (PU) protocol suitable for mobile ah-hoc network in terms of SNT, is proposed. The network overhead and data transmission delay ore reduced, by considering both ad-hoc link reliability and the number of hops. Our empirical performance evaluation comparing to AODV (8) shows that the enhancement is up to about 31% for SNT depending upon the mobility of nodes.

• Journal of the Korean Institute of Gas
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• v.16 no.4
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• pp.8-15
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• 2012

The GO-FLOW methodology is capable of assessing system reliability. It models the system into a GO-FLOW chart with signal lines and operators and assesses the reliability of system by assessing the GO-FLOW chart sequential. But, as it models one component of system into several operators, the GO-FLOW chart which is different from the system flow diagram be modeled. Also, as it models the real operation time into "time point", it is hard to assess the reliability change according to the real operation time. Therefore, in this paper, the new GO-FLOW methodology which use the function(success/failure) of system components has been developed. It can assess the successful operating probability of system, regardless of the operating status of components. As it models one component of system into one operator, the GO-FLOW chart which is similar the system flow diagram can be modeled. Also, it is able to easily assess the successful probability of system according to the real operation time using the time in the operators.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1364-1366
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• 1997

To operate electric power systems economically and stably, and to supply the electric power of good quality, it is necessary that the measured information (current, voltage, and so on) be detected and transmutted with high reliability and high effieincy. For the reason, the optical magnetic field sensor is possible to rapidly detect to over current and recover when electric power line have fault. In addition, the optical sensor have no electro magnetic distortion and no electric insulation. In this study, we designed OCR(Over Current Relay) using optical sensor. The designed OCR using optical sensor was measured characteristic and compared contentional OCR. This system have highest optical advantages and reliability.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.51-54
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• 1991

As a transmission network planning should be optimal in the sense of technology, economy and reliability, an adequate optimization tool is required. The simulation model is valuable at this case. It enables the planner to detect the weak points of the system by providing the planner with unsupplied powers, operating cost, and active losses at each substation node and each line. This paper represent the example of application of simulation model for power system planning.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.9
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• pp.481-486
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• 2004

In operation of distribution system, $DG_s$ Distributed Generations) are installed as an alternative of extension and establishment of substations and transmission and distribution lines according to increasing power demand. In operation planning of $DG_s$, determining optimal capacity and allocation gets economical pro(it and improves power reliability. This paper proposes determining a optimal number, size and allocation of $DG_s$ needed to minimize operation cost of distribution system. Capacity of $DG_s$ (or economical operation of distribution system estimated by the load growth and line capacity during operation planning duration, DG allocations are determined to minimize total cost with power buying cost. operation cost of DG, loss cost and outage cost using GA(Genetic Algorithm).

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2001.10a
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• pp.199-202
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• 2001

This article deals with stochastic reliability systems that include a repair facility and unreliable machines: the main facility of working and an auxiliary facility of "super-reserve" machines. The number of super-reserve machines are random number with a arbitrarily distribution and working machines break down exponentially. Defective machines line up for repair, whose durations are arbitrarily distributed. Refurbished machines return to the main facility. If the main facility is restored to its original quantity, the repair facility leaves on routine maintenance until all of super-reserve machines are exhausted. Then, the busy period is regenerated. The whole system also falls into the category of closed queues, with more options than those of basic models. The techniques include two-variate Markov and semi-regenerative processes, and a duality principle, to find the probability distribution of the number of intact machines. Explicit formulas obtained demonstrate a relatively effortless use of functionals of the main stochastic characteristics (such as expenses due to repair, maintenance, waiting, and rewards for higher reliability) and optimization of their objective function. Applications include computer networking, human resources, and manufacturing processes.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.11
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• pp.686-689
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• 2014

Electrostatic discharge has been considered as a major reliability problem in the semiconductor industry. ESD reliability is an important issue for these products. Therefore, each I/O (Input/Output) PAD must be designed with a protection circuitry that creates a low impedance discharge path for ESD current. This paper presents a novel Lateral Insulated Gate Bipolar (LIGBT)-based ESD protection circuit with latch-up immunity and high robustness. The proposed circuit is fabricated by using 0.18 um BCD (bipolar-CMOS-DMOS) process. Also, TLP (transmission line pulse) I-V characteristic of proposed circuit is measured. In the result, the proposed ESD protection circuit has latch-up immunity and high robustness. These characteristics permit the proposed circuit to apply to power clamp circuit. Consequently, the proposed LIGBT-based ESD protection circuit with a latch-up immune characteristic can be applied to analog integrated circuits.