• Title/Summary/Keyword: transport demand

Search Result 573, Processing Time 0.027 seconds

A study on the dynamic characteristics of exciting Flexural beam by ultrasonic wave (초음파에 의해서 가진되어지는 Flexural Beam의 동특성에 관한 연구)

  • Jeong, Sang-Hwa;Shin, Sang-Moon;Kim, Gwang-Ho;Lee, Sang-Hee;Kim, Ju-Hwan
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2006.11a
    • /
    • pp.792-796
    • /
    • 2006
  • In recent years, the semiconductor industry and the optical industry is developed rapidly. The recent demand has expanded for optical components such as a optical lens, a optical semiconductor and a measuring instrument. Object transport systems are driven typically by the magnetic field and the conveyer belt. Recent industry requires more faster and efficient transport system. However, conventional transport systems are not adequate for transportation of optical elements and semiconductors. Because conveyor belts can damage precision optical elements by the contact force and magnetic systems can destroy the inner structure of semiconductor by the magnetic field. In this paper, the levitation transport system using ultrasonic wave is developed for transporting precision elements without damages. This transport system is using 2-mode ultrasonic wave excitation and flexural beam modes shapes are evaluated. It compared simulation results with experimental results

  • PDF

Study on Transport Policy Assessment Using the Integrated Land Use Transport Model (통합 토지이용 교통모형을 이용한 교통정책평가에 관한 연구 I: 기존사례연구를 중심으로)

  • Lee, Seung-Jae;Sohn, Jhi-Eon
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.9 no.1
    • /
    • pp.111-120
    • /
    • 2010
  • The policy which encourages people to use cars on the road has been based on the growth of economy in Korea. It has also caused the concentration and overcrowding in Seoul. That's because the increasing number of people possessing cars interconnects with the urban development. The transportation is a derived demand; so many scholars have recognized the importance of understanding the relationship between urban land use and transport. Considering such importance, this study theoretically compared the developed urban land use-transportation models each other and outlined the particular models briefly. Models were categorized by 2 types; optimizing model and predictive mode. Predictive model is also defined by static model, entropy based model, spatial-economic model, and activity model. After studying models, we investigated other major cities in America. This process is the pre-step for transport policy assessment. Through careful literature review, we can finally develop the integrated land-use transportation model in Seoul metropolitan area. In addition, we will be able to deal the changes of traffic demand pattern under U-Society. Consequently, the results of this study can be applied to ITS projects in the future.

A Comparative Analysis of Mobility Service Satisfaction by Driving Subjects and Experiences of the Latest Technology : Focused on Automated Driving Service (모빌리티 서비스의 운전 주체 및 신기술 경험 여부에 따른 만족도 비교분석 : 자율주행서비스를 중심으로)

  • KIM, Tagyoung;SEO, Jihun;BANG, Soohyuk
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.21 no.5
    • /
    • pp.103-116
    • /
    • 2022
  • The South Korean Ministry of Land, Infrastructure, and Transport designated seven automated driving test beds required to evaluate vehicle performance every year for the expansion of mobility services based on automated driving. As a fundamental study, we suggested a necessary example of evaluating the performance with a satisfaction survey for the services before the evaluation. First, we surveyed the perception of automated driving services of users and the public in Sejong-si, South Korea. The survey showed that the users had a higher level of awareness of automated driving technology and intention to use it than the public. Second, the satisfaction survey was conducted on demand-responsive public transportation and automated driving service users. Notably, using the Wilcoxon Rank Sum Test, among the non-parametric statistical analysis methods, we found that safety-related factors affected the overall satisfaction of users of automated driving services. On the other hand, in the case of the demand-responsive public transportation service users, factors related to service convenience affected overall satisfaction. Hence, the results of these surveys are expected to be used as basic data and guidelines to improve the quality of automated driving services and policy establishment.

Assembly Modeling Framework for Thin-Film Transistors (조립형 박막 트랜지스터 모델링 프레임워크)

  • Jung, Taeho
    • Journal of the Semiconductor & Display Technology
    • /
    • v.16 no.3
    • /
    • pp.59-64
    • /
    • 2017
  • As the demand on displays increases, new thin-film transistors such as metal oxide transistor are continuously being invented. When designing a circuit consisting of such new transistors, a new transistor model based on proper charge transport mechanisms is needed for each of them. In this paper, a modeling framework which enables to choose charge transport mechanisms that are limited to certain operation regions and assemble them into a transistor model instead of making an integrated transistor model dedicated to each transistor. The framework consists of a graphic user interface to choose charge transport models and a current calculation part, which is also implemented in AIM-SPICE for circuit simulation.

  • PDF

Present Status of Domestic Air Transport Industry and Policy Proposal for National Carrier's Sustainable Development (국내 항공운송산업의 현황 및 지속발전을 위한 정책제언)

  • Choi, Doo-Hwan;Hwang, Ho-Won
    • The Korean Journal of Air & Space Law and Policy
    • /
    • v.33 no.2
    • /
    • pp.3-34
    • /
    • 2018
  • Korea's air transport industry has a 70-year history since Korea National Airline was establishment in October 1948. Korea has 9 airlines which have international air transport business licenses, and as of 2017, air transport performance(Domestic & International) is ranked 8th in the world. Through analysis of Korea's air transport industry, this paper examines the essential problems of the domestic air transport industry and what policies and laws should be supplemented, and presents an "Policy Directions for the Air Transport Industry" that can continue to grow into a global aviation leading country in the future. Analysis of aviation statistics shows that the nation's air transport industry has a very high growth rate, and national airlines continue to invest in sustainable growth. Furthermore, new companies are also trying to enter the market. As of November 2018, four companies applied for licenses for international air transport business, one for international air transport business (cargo) license, and the Ministry of Land, Infrastructure and Transport is expected to decide whether to issue the license by first quarter of 2019. While some expect price reductions and consumer benefits through competition promotion, others worry about worsening airline financial structures and reducing safety investment due to competition. To sum up the problems of the nation's air transport industry, first, low-cost airlines focus only on attracting domestic demand, and thus have a weak foundation for continued growth. Second, the rapid growth in recent years has led to the lack of aviation professionals such as pilots and technicians and the saturation of slots at major airports. Third, since the financial soundness of airlines is not systematically managed, the financial situation of airlines can quickly deteriorate and the damage can be attributed to consumers. In order for the national airlines to continue to develop, the first is to focus on the endless demand of the global aviation market and to secure international competitiveness. Second, the government should support the airline infrastructure according to the size of the air transport industry, third, we will systematically nurture aviation experts who will lead the future of the nation's air transport industry, and finally, the government will have to continuously manage the financial status of airlines to prevent consumer damage in advance. Nowadays the air transport industry has become very competitive. Not only do airlines have to work hard for the sustainable development of national airlines, but all government agencies must support our airline companies in policy to win international competition.

An Analysis of Demand Elasticity to Facilitate the Use of Public Transportation in the Administrative City (행정중심복합도시 대중교통 이용활성화를 위한 수요탄력성 분석)

  • Kim, Tae-Gyun;Park, Ji-Eun;Lee, Yun-Sang
    • Land and Housing Review
    • /
    • v.9 no.3
    • /
    • pp.9-18
    • /
    • 2018
  • Administrative city has been developed step by step aiming to being a public transport-oriented new city. In spite of its primary goal, administrative city is dominated by car-oriented tansportaion system because the supply of public transportation has not been adequately and timely performed. In this study, we investigate the current situation related to (public) transportation use in administrative city. Also, we examine the issues of traffic system through a survey on residents' consciousness about public transportation use. Additionally, the analysis of demand elasticity according to the change of the conditions of using public transportation and passenger car is conducted for passenger car users. As a result, it is analyzed that as the neighborhood is more stabilized after the completion of development the resistance to the abandonment of passenger car is higher when the tide demand control method is introduced. Therefore, it is concluded that pre-emptive public transportation supply and the management of car demand management are necessary for the activation of public transportation in Administrative city.