• International Journal of Fuzzy Logic and Intelligent Systems
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• 제8권3호
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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 information and communication convergence engineering
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• 제22권3호
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• pp.173-180
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• 2024

This study proposed an interdigital band-pass filter based on the microstrip transmission line. When designing a conventional structure for an interdigital filter based on the characteristics of the 5th order transmission line, seven resonators are required. By changing the impedance of the resonator adjacent to the feed line, the proposed interdigital band-pass filter was designed to reduce the number of resonators compared to conventional interdigital band-pass filters. Consequently, the resonator order decreased, and return and insertion losses become comparable to that in case of a conventional interdigital filter design. The proposed band-pass filter was designed with a center frequency of 2.75 GHz and a bandwidth of 1.5 GHz. Furthermore, based on various transmission characteristics such as group delay and coupling coefficient, two band-pass filters were designed, compared, and analyzed.

• Journal of Advanced Marine Engineering and Technology
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• 제19권3호
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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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• 제8권3호
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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.

• 한국광학회지
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• 제13권6호
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• pp.515-520
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• 2002

광학 반사경에서 일어나는 입사광과 반사광의 광로정변화와 분위기변화와의 관계를 조사했다. 분위기 변화요소로는 기압, 온도, 습도 그리고 $CO_2$함유량 등을 예로 들었다. 이들의 변화에 따른 광로정 변화치의 측정기법을 개발하여 실험 결과로부터 광로정 변화치를 정량화할 수 있음을 보였으며. 습도변화가 광로정의 변화에 가장 큰 영향을 미친다는 것을 확인하였다.

• Journal of Welding and Joining
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• 제28권4호
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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.

• 산업경영시스템학회지
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• 제40권1호
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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.

• 한국도로학회논문집
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• 제14권3호
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• pp.33-39
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• 2012

배수성 포장에 있어 기능적 평가인 투수성 실험과 더불어 소음저감 측정을 서울시에서 시공한 구간에서 실시하였다. 소음측정은 두 가지 방법을 이용하였는데 그 방법은 Pass-by 방법과 NCPX(Novel Close Proximity) 방법을 이용하였다. Passby 방법은 교통량에 따른 소음원이 전달되는 것을 측정하는 방법이고, NCPX는 타어어와 포장 표면간의 마찰음을 측정하는 방법이다. 현장투수시험을 위해서는 총 5개의 구간에서 실시하였으며 각 구간마다 주행부와 비주행부로 나뉘어 측정하였다. 3개 구간의 Pass-by 측정을 위해서는 교통소음원 발생점으로부터 인접한 곳에서 측정을 실시하였고 또한 공원내부 혹은 단지 내부에서도 소음을 측정하였다. 마지막으로 NCPX 측정은 4군데서 실시하였다. 결과적으로 배수성 포장의 기능인 투수성과 소음저감이 2, 3년 사이에서는 그 기능을 잘 유지함을 알 수 있었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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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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• 제21권1호
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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.