• Title/Summary/Keyword: bimodal

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A Study of the Estimation of Utilities of Usage Attributes of BRT and Bimodal Tram Using Conjoint Analysis (Case of the City of Sejong) (컨조인트 분석을 이용한 BRT 및 바이모달 트램 이용 속성의 효용 산정 연구 (세종시를 중심으로))

  • Park, Sangmin;Kim, Kyung Hyun;Ko, Han Geom;Mok, Jai-Kyun;Lee, Jong-Hwa;Yun, Ilsoo
    • International Journal of Highway Engineering
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    • v.19 no.4
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    • pp.45-52
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    • 2017
  • PURPOSES : This study was initiated to estimate the utilities of usage attributes of BRT and Bimodal Trams using a conjoint analysis method in order to identify the important features pertaining to the use of BRT and Bimodal Trams. METHODS : For this purpose, important attributes and those level in the use of BRT and Bimodal Trams in the city of Sejong were identified. Next, a profile questionnaire pertaining to BRT and Bimodal Trams was designed for the conjoint analysis, and a survey was conducted in the city of Sejong. Using SPSS software, conjoint analysis was performed to identify the important attributes vis-$\acute{a}$-vis the use of BRT and Bimodal Trams in the city of Sejong. Finally, the utilities for individual attributes were calculated based on the models estimated by the conjoint analysis. RESULTS : The results of the conjoint analysis were used to identify the important attributes. With regard to the usage of BRT, users indicated that fare was the most important attribute with the highest utility. In the case of Bimodal Trams, the users indicated that the number of seats and internal environment were the most important attributes with the highest utilities. CONCLUSIONS : Based on the results of the conjoint analysis, the important attributes pertaining to the use of BRT and Bimodal Trams in the city of Sejong were identified. Our study indicates that BRT in the city of Sejong needs to be upgraded to improve the utilities of the important attributes. Currently, Bimodal Trams has not been introduced completely in the city of Sejong. However, in the future, when the introduction of Bimodal Trams is completed, the important attributes should be emphasized in order to improve the quality of its service.

Investigation on Flocculi-floc Interaction and Flocculation in Extracellular Polymeric Substances, Ionic Species and Clay-containing Suspension (생체고분자물질 농도와 이온강도에 따른 점토입자 현탁액의 응집핵-응집체 이군집 응집 특성 연구)

  • Kim, Jae In;Lee, Byung Joon
    • Journal of Korean Society on Water Environment
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    • v.36 no.3
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    • pp.185-193
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    • 2020
  • Bimodal flocculation describes the aggregation and breakage processes of the flocculi (or primary particles) and the flocs in the water environment. Bimodal flocculation causes bimodal size distribution with the two separate peaks of the flocculi and the flocs. Extracellular polymeric substances and ionic species common in the water environment increase the occurrence of bimodal flocculation and flocculi-floc size distribution, under the flocculation mechanisms of electrostatic attraction and polymeric bridging. This study investigated bimodal flocculation and flocculi-floc size distribution, with respect to the extracellular polymeric substance concentration and ionic strength in the kaolinite-containing suspension. The batch flocculation tests comprising 0.12 g/L of kaolinite showed that the highest flocculation potential occurred at the lowest xanthan gum (as extracellular polymeric substances) concentration, under all the ionic strengths of 0.001, 0.01, and 0.1 M NaCl. Also, it was important to note that the higher ionic strength resulted in the higher flocculation potential, at all the xanthan gum concentrations. The bimodal flocculation and flocculi-floc size distribution became apparent in the experimental conditions, which had low and intermediate flocculation potential. Besides the polymeric bridging flocculation, steric stabilization increased the flocculi mass fraction against the floc mass fraction, thereby developing the bimodal size distribution.

Evaluating Transport Indices for A Decision on the Level of Introducing Bimodal TRAM System (신교통 바이모달트램 시스템 도입수준 결정을 위한 지표 평가)

  • Choi, Myoung-Hun;Eom, Jin-Ki;Lee, Jun;Sung, Myoung-Joon
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.762-768
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    • 2010
  • The Bimodal Tram being developed in Korea is a new transit system that provides both benefits of rail and bus systems in terms of accessibility and fixed time schedule. The Bimodal Tram is expected to take an important role of transit system in Korea under the national strategy of transportation system such as 'Low Carbon and Green Growth' for the next generation. This study does define the key indices considered for a decision of introducing the Bimodal Tram system and develop a finalized index, BSI(Bimodal Score for Introduction), showing the level of Bimodal Tram system introduced at a city level. The transport/transit system varies depending on cities with respect to demographic characteristics, travel patterns, financial capabilities, etc. This study will help any cities where transport agencies are trying to introduce the Bimodal Tram as a new transit system.

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A Study on the Environmental Evaluation of Bimodal Tram using Life Cycle Assessment (LCA) (전과정평가를 이용한 바이모달 저상굴절 차량의 환경성 진단에 관한 연구)

  • Lee, Jae-Young;Kim, Yong-Ki;Yoon, Hee-Taek;Lee, Cheul-Kyu;Lim, Noh-Hyun
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.1128-1130
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    • 2008
  • Bimodal tram is a new public transportation to improve the existing traffic system. The purpose of this study was to investigate the environmental characteristics of the developed bimodal tram through its life cycle. The used tool was life cycle assessment (LCA), which could evaluate environmental loads quantitatively for a product. Based on bill of material (BOM), the environmental impacts of bimodal tram was calculated from manufacturing to operating phase. Among impact categories, photochemical oxidant creation potential (POCP) was the highest, which was resulted from the manufacturing and the combustion of CNG used as a fuel of bimodal tram. In the future, the application of LCA results can enhance increasingly the environment of bimodal tram as an environmental-friendly transportation.

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Design and Requirement Analysis for Vehicle operating computer of Bimodal Tram (바이모달트램용 차량운영컴퓨터의 요구사항 분석 및 설계)

  • Lee, Kang-Won;Yoon, Hee-Taek;Kim, Gun-Kuk;Hwang, Wi-Kyung
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.1930-1935
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    • 2008
  • Bimodal tram is able to run both general and special road. It has also the advantages of both public bus and subway which have the charateristics of easiness to approach and punctuality respectively. These advantages are accomplished by the cooperative communication between the control center and bimodal tram which is running with the fleet. This paper have investigated the requirement analysis and designing of the car operating computer system which have the functions of communication, broadcasting and display. car operating computer system communicates between bimodal tram and control center with wireless antenna. It can also transmit the location and status information of bimodal tram to control center for managing the bimodal tram fleet on road efficiently and economically.

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A preliminary study of sound quality evaluation of cochlear implant users (인공와우 사용자의 심리음향적 음질평가 예비연구)

  • Bahng, Junghwa;Oh, Soo Hee
    • The Journal of the Acoustical Society of Korea
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    • v.41 no.1
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    • pp.45-51
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    • 2022
  • Sound quality evaluation is one of the psychoacoustic methods to measure subjective judgements for sound color. The purpose of this study is to investigate sound quality benefits of bimodal users by comparing sound quality scores between bimodal hearing condition and unilateral cochlear implant(CI) condition as a preliminary study. Thirteen bimodal users and seven unilateral CI users were participated in this study. Audiologists performed pure tone and speech audiometry and measured functional gain and real-ear insertion gain. Subjective assessment of sound quality was followed with four sounds including violin sound, male and female voices, and refrigerator noise. Participants judged the sound quality with six sound quality index. Bimodal users showed mean 0.8 points more sound quality improvements in bimodal condition than unilateral CI condition. Group comparison between bimodal and unilateral CI users showed no differences. A follow-up study of sound quality tools and methods should be considered to evaluate subjective bimodal benefits of cochlear implant users.

Preparation of electro-catalysts supported on the bimodal porous carbon for polymer electrolyte fuel cell (Bimodal 다공성 탄소지지체에 담지된 고분자전해질연료전지용 전극촉매 제조)

  • Hwang, So-hee;Park, Gu-Gon;Yim, Sung-Dae;Park, Seok-Hee;Kim, Han-Sung;Yang, Tae-Hyun;Kim, Chang-Soo
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.652-655
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    • 2009
  • The bimodal porous carbons were synthesized by using imprinting method with templates of SBA-15 particle and silica sphere and applied as supporting materials for the electro-catalyst of polymer electrolyte fuel cell (PEFC). The silica spheres with diameter size of 100 nm and SBA-15 particle having 200 nm -250 nm diameter and 700 nm -900 nm length were synthesized in this work. The bimodal porous carbons (S100) were prepared by using the silica spheres and SBA-15 as templates and mesophase pitch as a carbon source. The PtRu nanoparticle of ca. 1.9 nm were supported on the bimodal porous carbon support and the resulting PtRu/S100 catalysts was tested by the cyclic voltammetry. The use of bimodal porous carbon showed in comparable electro-catalytic activities with commercial catalyst. Though unclear effects of bimodal porosity of supports could be obtained in the scope of this study, morphological advantage in electrical conductivity can be considered on the electro-catalytic activity.

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A Simulation Study of the Performance of a Propulsion Equipment for Bimodal Tram (바이모달 트램의 추진장치 성능 모의)

  • Bae, Chang-Han;Mok, Jai-Kyun;Chang, Se-Ky;Lee, Kang-Won
    • Journal of the Korean Society for Railway
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    • v.12 no.1
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    • pp.122-128
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    • 2009
  • A bimodal low-floor tram is designed to provide the flexibility of bus and the punctuality of trains together to the passengers. The propulsion equipment of the bimodal tram is a series hybrid type using a set of CNG engine generator and Li-polymer battery. The present paper describes the specifications of the propulsion system in the bimodal tram which was drawn by a desirable driving cycle. In addition, it shows how the propulsion system of the bimodal tram can be controlled. With using a computer simulation tool of hybrid vehicles, ADVISOR, the performance of the bimodal tram was verified.

The Operation and Facility Requirements by the Level of Bimodal Tram System (바이모달트램 도입수준에 따른 운영 및 시설 요구사항 연구)

  • Sung, Myoung-Joon;Eom, Jin-Ki;Lee, Jun;Choi, Myoung-Hun
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.784-793
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    • 2010
  • The Bimodal Tram is expected to take an important role of transit system in Korea under the national strategy of transportation system such as 'Low Carbon and Green Growth' for the next generation. Recently, many cities are thinking of Bimodal Tram as an alternative transit mode that comes up with the policy of 'Low Carbon and Green Growth'. But, there is no specific manual for introducing Bimodal Tram with various requirement of facility and operation regarding the service level of Bimodal Tram system. This study considered the Bimodal Tram system with three different service level- high, mid, and low- and defined the service elements by facility and operational perspectives. This study is expected to help any cities where transport agencies are trying to introduce the Bimodal Tram with different level of service as a new transit system.

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Development of measurement equipment for hybrid propulsion system of bimodal tram (바이모달 트램의 직렬형 하이브리드 추진시스템 계측장비 개발)

  • Bae, Chang-Han;Chang, Se-Ky;Mok, Jai-Kyun
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.241-248
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    • 2010
  • A bimodal low-floor tram can provide the punctuality of trains and the flexibility of bus together to the passengers. Its propulsion system is a series hybrid type using a set of CNG engine generator and Li-polymer battery. This paper presents a development of the measurement equipment for fine-tuning of a series hybrid propulsion system of bimodal low-floor tram. Its configuration schemes are described and certified using the measurement data of bimodal low-floor tram.

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