• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.408-413
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• 2011

In the present study, annoyance caused by diverse construction noises was evaluated through surveys and laboratory experiments. A survey with a total of 110 construction workers was carried out to investigate annoyance from construction noises at different construction phases. The most effective item of adverse by construction noise was annoyance and the most annoyed construction stage was destruction construction. Between work performance and work safety had correlation as well as between work safety and speech interference. Participant's noise sensitivity were significant between low and high group at work performance, work safety, speech interference.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.05a
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• pp.43-46
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• 2006

In this study on the appliable Asphalt sheet of monolithic and inorganic matter waterproofing material using of field because of problem of complex waterproofing sheet. Before this cement polymer modified waterproof coating and appliable asphalt sheet of monolithic whether have stability by method of construction about all style waterproofing that evaluate to new method of construction development naturally big emphasis put and try to approach. Did performance test item first at, as a result, drew by suitable thing in all KS items. This is considered to have more effective spot construction work because if means that have stability by material as well as method of construction.

• Journal of Information Technology Applications and Management
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• v.24 no.1
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• pp.111-128
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• 2017

Existing studies for recommender have focused on recommending an appropriate item based on the customer preference. However, it has not yet been studied actively to recommend purchase timing for the repurchase product despite of its importance. This study aims to propose MLP and RNN models based on the only simple purchase history data to predict the timing of customer repurchase and compare performances in the perspective of prediction accuracy and quality. As an experiment result, RNN model showed outstanding performance compared to MLP model. The proposed model can be used to develop CRM system which can offer SMS or app based promotion to the customer at the right time. This model also can be used to increase sales for repurchase product business by balancing the level of order as well as inducing repurchase of customer.

• Journal of KIISE:Software and Applications
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• v.26 no.1
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• pp.80-80
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• 1999

As Temporal DataBase Systems(TDBSs) manages both the historical versions and the current version of each data item, a temporal transaction may access more data records than atransaction in traditional database systems. Hence, the concurrency control subsystem of temporaldatabase management system should be able to correctly and efficiently detect actual conflicts amongconcurrent temporal transactions while the cost of detecting conflicts is maintained in low levelwithout detecting false conflicts which cause severe degradation of system throughput.In this paper, Two-Level Conflict Detection(TLCD) scheme is proposed for efficient conflictdetection between concurrent temporal transactions in TDBs. In the proposed TLCD scheme, sincechecking conflict between concurrent temporal transactions is performed at two levels, i, e., logicallevel and physical level, conflicts between concurrent temporal transactions are efficiently and correctlydetected,Furthermore, we also evaluate the performance of the proposed TLCD scheme with those oftraditional conflict detection schemes, logical-level conflict detection scheme and physical-level conflictdetection scheme by simulation approach, The result of the simulation study shows that the proposedTLCD scheme outperforms the previous conflict detection schemes with respect to the averageresponse time.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.10a
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• pp.122-126
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• 1996

In recent years, plenty of problems in the large-scaled bridges, piers…have been reported to the public due to the severe environment factors. The use of Epoxy-Coated reinforcement against salt and sulfate corrosion is considered as a reasonable solution and tested to study the bond performance between the thickness of coating and bond stresses. The results are that the strength of bond was decreased by 10 to 13 percent in the case of 100$\mu\textrm{m}$ of coating thickness and by 15 to 25 percent in the case of 200$\mu\textrm{m}$ to 300$\mu\textrm{m}$ and significantly fell down when the thickness was above 300$\mu\textrm{m}$. Accordingly, a 200$\mu\textrm{m}$ coating-thickness to the reinforcement is suggested to maintain the acceptable bond mechanism and goes well with the ASTM(item NO.A775) and those of Korean Concrete Institute.

• Journal of Korean Institute of Industrial Engineers
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• v.28 no.3
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• pp.240-246
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• 2002

In this paper, economic screening procedures with dichotomous performance variable T and continuous screening variable X are considered when the rejected items are reprocessed. Two models are considered; normal and logistic models. It is assumed that X given T is normally distributed in the normal model, and P(T=1|X=x) is given by a logistic function in the logistic model. Profit models are constructed which involve four price/cost components; selling price, cost from an accepted nonconforming item, and reprocessing and inspection costs. Methods of finding the optimal screening procedures are presented and numerical examples are given.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1287-1292
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• 2005

With opening of KTX, Korea Railway have carried out a variety of marketing strategies unprecedented, which have brought successful results for dramatical increasing passengers in KTX from 72 thousand passengers per day in 2004 to 85 thousand passengers per day in 2005. These marketing strategies for Korea Rail to use in increasing passengers for KTX are the following: special discount fare system for non-season to penetrate into transport market in the first time, fare system reform considering to customers' willing to pay, new item development by each specific market like contracting transport, YMS(Yield Management System) by stages, Home-ticket-and-e-ticket and tele-marketing service, and wide range covering sales network making it comfortable for users in KTX. This paper discusses these successful marketing strategies and its performance and finally suggests strategic implications for KTX growth.

• Journal of Applied Reliability
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• v.9 no.3
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• pp.219-231
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• 2009

Power light emitting diodes(LED) for lighting fittings are so much environment-friendly, highly reliable and consume less energy that they are widely used at home and in industries such as electronics, telecommunications and industrial machineries. However, they are exposed to a very diverse environment and consists of complex components and, therefore needs careful approach to the enhancement and assessment of reliability of the item. In this article reliability assessment criteria for LED are established in terms of performance assessment test, reliability assessment test and accelerated test.

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.2
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• pp.255-265
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• 1995

Due to advances in automated manufacturing systems and automatic inspection equipment, complete inspection has drown increased attention recently and has become a widespread practice. In a complete inspection plan all of the items are subject to acceptance inspection If an item fails to meet the predetermined specifications, it is rejected. In this paper, economic complete inspection plans are developed in situations where rejected items are reworked Complete inspections based on the performance variable of interest or a variable which is correlated with the performance variable are considered. Cost models are constructed which involve cost incurred by imperfect quality rework cast and quality inspection cost Methods of finding the optimal complete inspection plans are presented and numerical examples are given.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.1
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• pp.39-46
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• 2006

PLL is a key item of power converter for power quality compensation and power flow control. This paper proposes a novel 3-phase PLL that is composed of ALC and PI controller. The operational principle was investigated through theoretical approach, and the performance was verified through computer simulations with MATLAB and experimental works with TMS320VC33 DSP board. The proposed 3-phase PLL shows accurate performance under the voltage disturbances such as sag, harmonics. phase-angle jump, and frequency change.