• International Journal of Fuzzy Logic and Intelligent Systems
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• v.8 no.3
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• pp.231-237
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• 2008

This research proposes a modified version of single pass algorithm specialized for text clustering. Encoding documents into numerical vectors for using the traditional version of single pass algorithm causes the two main problems: huge dimensionality and sparse distribution. Therefore, in order to address the two problems, this research modifies the single pass algorithm into its version where documents are encoded into not numerical vectors but other forms. In the proposed version, documents are mapped into tables and the operation on two tables is defined for using the single pass algorithm. The goal of this research is to improve the performance of single pass algorithm for text clustering by modifying it into the specialized version.

• Journal of Advanced Marine Engineering and Technology
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• v.19 no.3
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• pp.107-118
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• 1995

The characteristics of the current waveforms and 3$\Phi$ power waveforms of the variable speed 3$\Phi$ AC motor system driven by the single-pulse PWM investigated in this paper. The system is composed of a digital bridge inverter and low pass LC filter. It is confirmed that current waveforms and 3$\Phi$ power waveforms can be improved by utilizing the high order low pass LC filter than that of lower order through computer simulation. Also, we propose the low pass LC filter revised from the conventional LC filter.

• International Journal of Contents
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• v.8 no.3
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• pp.100-104
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• 2012

In this paper, a unit cell for low pass filter design by using composite right and left-handed transmission line in conductor-backed coplanar waveguide is proposed. The characteristics of the unit cell are analyzed in order to design a low pass filter in small sizes. By changing the sizes of the unit cell, the parameters of right-handed and left-handed immittance components are changed and the desired characteristics of the unit cell are achieved. The equivalent circuit of the unit cell is extracted and analyzed either. As a result, the simulation results of the unit cell and the equivalent circuit are almost identified. The movement and energy distributions of electromagnetic field are shown to confirm the property of the unit cell. In the end, a low pass filter is demonstrated by cascading three proposed unit cells, which shows cutoff frequency of 1.53GHz and deep attenuation from 2.23GHz to 4.49GHz lower than -50dB.

• Korean Journal of Optics and Photonics
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• v.13 no.6
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• pp.515-520
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• 2002

The variation of the optical pass length between incident and reflective beam in a multilayer thin film reflection mirror is investigated. This variation is caused mainly by environmental parameters around the optical system, such as the air pressure, temperature, humidity and $CO_2$concentration. In this paper, a new method for measuring optical pass length variation is proposed. This optical pass length is measured against the above parameters by experiment. From the experimental results, it is clarified that the optical pass length is mostly effected by humidity changes.

• Journal of Welding and Joining
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• v.28 no.4
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• pp.26-32
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• 2010

The purpose of this study is to evaluate the residual stresses at the multi-pass FCA weldment using the finite element analysis (FEA). In order to do it, an H-type specimen was selected as a test specimen. The variable used was in-plane restraint intensity. The temperature distribution at the multi-pass FCA butt weldment was evaluated in accordance with the relevant guidance recommended by the KWJS. The effective conductivity for the weld metal corresponding to each welding pass was introduced to control the maximum temperature below the vaporization temperature of weld metal. The heat flux caused by welding arc was assumed to be applied to the weld metal corresponding to welding pass. With heat transfer analysis results, the distribution of transverse residual stresses was evaluated using the thermo-mechanical analysis and compared with the measured results by XRD and uniaxial strain gage. In thermo-mechanical analysis, the plastic strain resetting at the temperature above melting temperature of $1450^{\circ}C$ was considered and the weld metal and base metal was assumed to be bilinear kinematics hardening continuum. According to the comparison between FEA and experiment, transverse residual stresses at the multi-pass FCA butt weldment obtained by FEA had a good agreement with the measured results, regardless of in-plane rigidity. Based on the results, it was concluded that thermo-mechanical FE analysis based on temperature distribution calculated in accordance with the KWJS’s guidance could be used as a tool to predict the distribution of residual stress of the multi-pass FCA butt weldment.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.1
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• pp.131-143
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• 2017

As the number of tourists visiting Seoul are continuously increasing, the demand of an integrative tour pass is also increasing. However, only a few tour passes are available for the tourists in Seoul. In this paper, we propose a new tour pass called "Seoul Landmark Pass" targeting foreign individual travelers and investigate the marketability of the proposed tour pass. For the configuration of the Seoul Landmark Pass we listed 17 candidate attractions charging entrance fee in Seoul, referring to e-guidebook on Visit Seoul web site. Among them we selected 6 attractions using the checklist with the attributes that foreign tourists would prefer. We also performed SWOT analyzes on existing tour passes to determine the benefits to be included in the proposed tour pass. To investigate the marketability of the proposed tour pass we have surveyed the foreign individual tourists in Seoul. Using the survey data, we have analyzed the intent of purchase by age, visiting period, visiting purpose, frequency of visit, and nationality to identify target customers. The results show that the intent of purchase is high among the Chinese tourists at the age of twenties who visited Seoul for the first time or second times. Also, the individual tourists prefer to bundle T-money card with the proposed tour pass. Finally, we have provided a brief review of the Price Sensitivity Measurement (PSM) method and applied PSM to determine the acceptable price range and the optimal price of the proposed tour pass. The optimal price of the proposed tour pass is determined at 53,000 won including T-money card.

• International Journal of Highway Engineering
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• v.14 no.3
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• pp.33-39
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• 2012

The functional evaluation of constructed permeable pavements was conducted in terms of water permeable performance and noise reduction measurements in Seoul city. The field measurements of noise was based on two methods such as pass-by and novel close proximity(NCPX). The pass-by test and NCPX method are related to noise propagation and tire/pavement interaction noise measurement, respectively. For the water permeable tests, five sections were chosen; furthermore, the measurements were conducted for both of wheel path and non-wheel path area. For the pass-by measurement, three sections were chosen; furthermore, two different locations, which were near measurement point to traffic noise and far measurement point inside park or hosing complex, were selected for each section. Finally, tire/pavement interaction noise measurements were carried out at four locations. The results show that the functional performance of water permeability and noise reduction was well remained within 2 or 3 years after permeable pavement construction.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1479-1486
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• 2000

This paper introduces the improved moving frame acoustic holography (MFAH) method and its application. MFAH allows us to visualize the noise generated by moving noise sources by employing a vertical line array of microphones affixed to the ground. The sound field generated by moving sources is different from that of stationary ones due to the movement of the sources. Therefore the measured sound pressure by the microphone on the ground has to be processed so that it cooperates the effect of the movement. This paper discusses the effect of moving noise sources on the obtained hologram by MFAH. This assures the applicability of MFAH to the visualization of moving sources. This paper also reviews the improved MFAH that can visualize a coherent narrow band noise and a pass-by noise. The practical applicability of the improved MFAH was demonstrated by visualizing tire noise during a pass-by test.

• The Journal of Korean Physical Therapy
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• v.21 no.1
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• pp.9-17
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• 2009

Purpose: The purpose of this study was to determine reliability and validity of the Postural Assessment Scale for Stroke Patients (PASS) in chronic stroke patients. Methods: A total of 43 stroke patients, who had a stroke more than 6 months previously, participated in the study. Reliability was determined by the intra-class correlation coefficient (ICC$_{3,1}$), Bland and Altman method and Cronbach's alpha by internal consistency. Validity was examined by correlation the PASS scores to the Berg Balance Scale (BBS), Trunk Control Test (TCT), and Fugl-Meyer Balance (FM-B) score. Results: The intra-rater reliability and the Absolute reliability of the PASS was good ICC$_{3,1}$=0.97 (95%CI 0.95$\sim$0.99) and excellent SEM=1.01 respectively. Cronbach's alpha value for PASS was found to be 0.94. There were significant correlations between the PASS and BBS, TCT, FM-B (r=0.65－0.96, p<0.01). Conclusion: The PASS provide reliable and valid instrument of the postural control assessment for chronic stroke patients.

• Transactions of Materials Processing
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• v.26 no.1
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• pp.28-34
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• 2017

Multi-pass shape rolling is performed to produce long products of arbitrary cross-sectional shapes. In the past, the multi-pass shape rolling process has been designed by the trial and error method or the experience of experts based on the empirical approach. Particularly, the design of roll caliber in shape rolling is important to improve product quality and dimensional accuracy. In this paper, the caliber design and pass schedule of multi-pass shape rolling were proposed for manufacturing piston ring wire. In order to design roll caliber, major shape parameter and dimension was determined by analysis of various caliber design. FE-simulation was conducted to verify effectiveness of proposed process design. At first, forming simulation was performed to predict shape of the product. Then, fracture of the wire was evaluated by critical damage value using normalized Cockcroft-Latham criteria. The experiment was carried out and the results are within the allowable tolerance.