• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.1
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• pp.122-130
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• 2001

In order to improve the efficiency of the design process and the quality of the resulting design, this study proposes a design method for determining design variables of an automotive wheel-bearing unit of double-row angular-contact ball bearing type by using a genetic algorithm. The desired performance of the wheel-bearing unit is to maximize system life while satisfying geometrical and operational constraints without enlarging mounting spae. The use of gradient-based optimization methods for the design of the unit is restricted because this design problem is characterized by the presence of discrete design variables such as the number of balls and standard ball diameter. Therefore, the design problem of rolling element bearings is a constrained discrete optimization problem. A genetic algorithm using real coding and dynamic mutation rate is used to efficiently find the optimum discrete design values. To effectively deal with the design constraints, a ranking method is suggested for constructing a fitness function in the genetic algorithm. A computer program is developed and applied to the design of a real wheel-bearing unit model to evaluate the proposed design method. Optimum design results demonstrate the effectiveness of the design method suggested in this study by showing that the system life of an optimally designed wheel-bearing unit is enhanced in comparison with that of the current design without any constraint violations.

• International journal of advanced smart convergence
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• v.10 no.3
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• pp.122-130
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• 2021

This study is about an Artificial Intelligence-based fake news identification system and its methods to determine the authenticity of content distributed over the Internet. Among the news we encounter is news that an individual or organization intentionally writes something that is not true to achieve a particular purpose, so-called fake news. In this study, we intend to design a system that uses Artificial Intelligence techniques to identify fake content that exists within the news. The proposed identification model will propose a method of extracting multiple unit factors from the target content. Through this, attempts will be made to classify unit factors into different types. In addition, the design of the preprocessing process will be carried out to parse only the necessary information by analyzing the unit factor. Based on these results, we will design the part where the unit fact is analyzed using the deep learning prediction model as a predetermined unit. The model will also include a design for a database that determines the degree of fake news in the target content and stores the information in the identified unit factor through the analyzed unit factor.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.411-414
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• 2015

The purpose of this study is to conduct a comparative analysis between Korea and the United States of the supply process of unit modular housing at both the factory production phase and the transportation and lifting phase, as part of an attempt to invigorate the unit modular housing market in Korea. Unlike the practice in the United States, one of Korea's unique characteristics is that the floor is constructed with reinforced concrete and hot water heating system. To do this, the wet method in Korea is used that includes concrete placement, curing and constructing hot water floor heating system at the factory production phase, which results in a longer production time and also requires the lifting of heavier loads. In the United States, interior and exterior finishing works of modular housing are performed by different companies, and the distance between the unit module factory and the construction site is quite far. This kind of dualized production structure may cause confusion when it comes to schedule management, procurement management, and stock management. Moreover, problems caused by external environmental factors such as wind and rainfall were reported in the course of long-distance transportation. The results of this case comparison are expected to provide fundamental data that will reduce the amount of trial and error in the unit module production, transportation and lifting work in Korea, which has a comparatively small number of unit modular housing cases.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.225-228
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• 2000

In this paper, we present the design of AAL2/AAL5 Type conversion Unit using among BSC, BTS, Core-Network in IMT-2000 system. We first briefly introduce the B-ISDN ATM Adaptation layer specification of Type 2 AAL and Type 5 AAL, and describe conversion flow and each module. And then this paper has designed AAL2/AAL5 Type Conversion Unit and simulated it.

• Journal of KSNVE
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• v.4 no.3
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• pp.337-343
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• 1994

A method of the leak detection from the pipe system by using accelerometer is proposed. The signal detected from accelerometer is proved experimentally to be a dispersive wave. Based on the experiments, a method using the narrow band pass filter and the unit impulse response function is analyzed. The method uses the characteristics of the unit impulse response function, that the function is available evenin the narrow band signal because, unlike the cross correlation, it is normalized by the auto spectrum. The accelerometer is quite easier to use than the hydrophone in adapting to the pipe system.

• Water Engineering Research
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• v.1 no.4
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• pp.279-291
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• 2000

A mathematical model using dynamic programming approach is applied to an optimal unit commitment problem. In this study, the units are treated as stages instead of as state dimension, and the time dimension corresponds to the state dimension instead of stages. A considerable amount of computer time is saved as compared to the normal approach if there are many units in the basin. A case study on the Lower Colorado River Basin System is presented to demonstrate the capabilities of the optimal scheduling of hydropower units.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.629-632
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• 2000

In this paper, we studied on the phoneme classification for Korean speech recognition. In the case of making large vocabulary speech recognition system, it is better to use phoneme than syllable or word as recognition unit. And, In order to study the difference of speech recognition according to the number of phoneme as recognition unit, we used the speech toolkit of OGI in U.S.A as recognition system. The result showed that the performance of diphthong being unified was better than that of seperated diphthongs, and we required the better result when we used the biphone than when using mono-phone as recognition unit.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.13-16
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• 2008

Solid oxide fuel cell(SOFC) is an electrochemical energy conversion system with high efficiency and low-emission of pollution. In order to reduce the operating temperature of SOFC system under $800^{\circ}C$, the thickness reduction of YSZ electrolyte to be as thin as possible, e.g., less than 10 ${\mu}m$ are considered with the microstructure control and optimum design of unit cell. Methods for reducing the thickness of YSZ electrolyte have been investigated in coin cell. Moreover, a large unit cell($8cm{\times}8cm$) for SOFC was fabricated using an anode-supported electrolyte assembly with a thinner electrolyte layer, which was prepared by a tape casting method with a co-sintering technique. we studied the design factors such as active layer, electrolyte thickness, cathode composition, etc,. by the coin type of unit cell ahead of the fabrication process of a large unit cell and also reviewed about the evaluation technique of a large size unit cell such as interconnect design, sealing materials and current collector and so forth. Electrochemical evaluations of the unit cells, including measurements such as power density and impedance, were performed and analyzed. Maximum power density and polarization impedance of coin cell were 0.34W/$cm^2$ and $0.45{\Omega}cm^2$ at $800^{\circ}C$, respectively. However, Maxium power density of a large unit cell($5cm{\times}5cm$) decreased to 0.21W/$cm^2$ at $800^{\circ}C$ due to the increase of ohmic resistance. However, It was found that the potential value of a large unit cell loaded by 0.22A/$cm^2$ showed 0.76V at 100hrs without the degradation of unit cell.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.3
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• pp.498-503
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• 2005

As important device that decide output load in superannuated thermoelectric power plant which do Turbine Load Set Motor device. This generation of electric power system operated Set Up Range Motor according to Set Up value that operator manufactures by hand circumvolve, and generation of electric power output load derision is consisted by internal action including Motor Therefore, in this research passively output load operated Turbine Motor Drive equipment that can have existing Turbine Load Set Motor Performance developing Digital Drive Unit device design. Also control algorithm implementation and existing Turbine Load Set Motor Drive and connection possibility through designed controlling system to connect basis function that decide development output load with Digital Drive Unit that designed also with existing Motor Drive Unit and can be operated.

• Journal of the Korea Safety Management & Science
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• v.13 no.3
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• pp.55-61
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• 2011

Unit cost for asbestos removal work which have been made out at government contract award for recent three years has been reviewed and shown with table. And the cost have been compared with ones made out by two agencies, American asbestos removal specialists, government ministry for making out comparison tables. First, legal and practical work status survey have been made to determine reasonability of introducing separate contract-awarding system, as a part of ensuring reasonable unit work cost. And then, two different status have been compared and there in introduction possibility of separate contract-awarding system, it is found out. In interior removal work case, it is thought that 50% by owner, 60% unit work cost by the expert of which removal specialist think as reasonable unit cost. the results for exterior and spray work method are shown with almost same context. Impact factors for determining unit work cost such as project mount, project kind, contract-awarding method, subcontract method have been compared with parties. Removal specialist and expert group have almost same ideas for project amount which has been hightestly weighed but owner's recognition has partially lower than specialists idea. There are almost no difference of recognition between three(3) parties for project kind. Idea comparison of reasonable unit work cost for asbestos removal work between three concerned parties has been analyzed and found out that expert group do unit work cost, 65% of which removal specialists estimate, in interior tex removal. And there is almost no difference between them in exterior roof slate removal. But there is considerable difference between them that owner estimates 50% unit cost of specialist one while expert group estimate 50% of specialist idea of unit removal cost.