• Title/Summary/Keyword: joint efficiency

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Economic Analysis with Development of Rapid Setting Alumina-based Binder for Road Repair (알루미나계열 속경성 도로 보수재료 개발에 따른 경제성 분석)

  • Yang, Hee-Jun;Yang, Min-Jae;Hong, Sung-In;Ann, Ki-Yong
    • Journal of the Korea Concrete Institute
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    • v.29 no.1
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    • pp.3-10
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    • 2017
  • In case of Korea highways, about 60% of highways are paved by concrete and more than 50% of them were repaired due to reduction in required performance such as damage in pave or joint and delamination of cover pavement. However, repairing old material in such structure generally costs a lot of money and induces difficulty in maintenance. Thus, enhanced material for ensuring economic efficiency should be developed. The present study designed concrete mixtures with 3 levels of replacement using OPC (0, 10, 20%) in calcium aluminate cement and to evaluate material performance for load pavement, experimental works for setting time, compressive strength and flexural strength were carried out on those materials. As a result, 20% replacement for OPC was determined as an optimized material in terms of required physical performance and its unit price. Moreover, to determine cost in load pavement economy analysis using a program (CA4PRS) was conducted with widely used paving materials. Result showed that application for 20% replacement for OPC was the most efficient in economical aspect, arising from 4.052 and 1.577 billion won for total construction and user cost, respectively.

Railway Governance and Power Structure in China

  • Lee, Jinjing
    • International Journal of Railway
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    • v.1 no.4
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    • pp.129-133
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    • 2008
  • Over the last $15{\sim}20$years, many countries have adopted policies of railway privatization to keep up with increasing competition from road and air transport. Although each country and case has its own history, market characteristics, political context as well as administrative process, railway privatizations (including railway restructure, concession etc.) in the west usually are accompanied with the establishment of new regulatory regimes. Therefore, railway governance has been innovating towards an interaction of government, regulator, industry bodies, user groups, trade unions and other interested groups within the regulatory framework. However, it is not the case in China. Although China had seen a partial privatization in some branch lines and is experiencing a much larger-scale privatization by establishing joint-ventures to build and operate high-speed passenger lines and implementing an asset-based securitization program, administrative control still occupies absolutely dominant position in the railway governance in China. Ministry of Railway (MOR) acts as the administrator, operator as well as regulator. There is no national policy that clearly positions railway in the transportation network and clarifies the role of government in railway development. There is also little participation from interested groups in the railway policy making, pricing, service standard or safety matter. Railway in China is solely governed by the mere executive agency. Efficiency-focused economic perspective explanation is far from satisfaction. A wider research perspective from political and social regime is of great potential to better explain and solve the problem. In the west, separation and constrains of power had long been established as a fundamental rule. In addition to internal separation of political power(legislation, execution and jurisdiction), rise of corporation in the 19th century and association revolution in the 20th century greatly fostered the growth of economic and social power. Therefore, political, social and economic organizations cooperate and compete with each other, which leads to a balanced and resonable power structure. While in China, political power, mainly party-controlled administrative power has been keeping a dominated position since the time of plan economy. Although the economic reform promoted the growth of economic power of enterprises, it is still not strong enough to compete with political power. Furthermore, under rigid political control, social organizations usually are affiliated to government, independent social power is still too weak to function. So, duo to the limited and slow reform in political and social regime in China, there is an unbalanced power structure within which political power is dominant, economic power expanding while social power still absent. Totally different power structure in China determines the fundamental institutional environment of her railway privatization and governance. It is expected that the exploration of who act behind railway governance and their acting strength (a power theory) will present us a better picture of railway governance as a relevant transportation mode. The paper first examines the railway governance in China and preliminarily establishes a linkage between railway governance and its fundamental institutional environment, i.e. power structure in a specific country. Secondly, the reason why there is no national policy in China is explored in the view of political power. In China, legislative power is more symbolic while party-controlled administrative power dominates political process and plays a fundamental role in Chinese railway governance. And then, in the part three railway finance reform is analyzed in the view of economic power, esp. the relationship of political power and economic power.

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Operation Model Design of Logistics Industrial estate -Focused on Transportation Network- (물류산업단지의 운영모델 설계 - 운송 네트워크를 중심으로-)

  • Shin, Jae Young;Kim, Woong-Sub
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2013.06a
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    • pp.214-215
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    • 2013
  • Current competition among companies than regional, the time constraints, it is globalization, Tilt the efforts of many to be operated by building the efficient distribution system to reduce logistics costs and improve customer service it is reality's there. Therefore, the need for industrial complexes environmentally friendly can be cost competitive companies perform cavitation region's increased. To build the distribution center these logistics system through a joint of freight and appropriate policy is required. In particular, efficient operation through the system construction of industrial complexes in the logistics system is very important in terms of friendly low-cost urban logistics, the environment. Since the traffic volume which is Jipufa and utilization of network is transported by a more appropriate technicians and means suitable operating model can efficiency is improved. However, despite these advantages, research network design has not been actively conducted due to the complexity of the problem. Therefore, in this study, by analyzing the logistics system, and presents the operating model through a simulation and basic settings for the model of the logistics complex based on the analysis result, the construction of infrastructure of logistics industry complex it is intended to present the article.

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A Study on the Change of Load Carrying Capacity of High-tension Bolt Joints by Critical Sections (단면결손에 따른 고장력볼트 체결부의 내하력 변화에 관한 연구)

  • Park, Jeong-Ung;Yang, Seung-Hyun;Jang, Seok-In
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.9
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    • pp.2402-2408
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    • 2009
  • This study conducted a static tensile test in order to prevent the lowering of load carrying capacity caused by critical sections made by over bolt holes in the base plate and the cover plate of steel member joints using high-tension bolts. The change of the load carrying capacity of joints was examined by comparison of the maximum load on joint fracture obtained from the tensile test with critical section rate and design strength. According to the results, the rate of decrease in strength was higher when the critical section rate was high, and in particular, decrease in strength was affected much more by critical sections in the base plate than by those in the cover plate. In high-tension bolt joints using over bolt holes for the base plate and the cover plate, load carrying performance was somewhat lower than that in joints using standard bolt holes, but the maximum tensile strength on facture was over 15% higher than design fracture strength. According to the results of this study, the use of over bolt holes in high-tension bolt joints had an insignificant effect on the lowering of load carrying capacity, so the allowance of over bolt holes in the joints of steel members is expected to enhance to the economy and efficiency of the works.

The Educational Significance of Place Experience through Folklore (설화를 통한 장소 경험의 융합교육적 의의 -청주 지역 전승의 <지네 장터> 설화를 중심으로)

  • Hwang, Yun-jeong;Seo, Myug-hee
    • Journal of Korean Classical Literature and Education
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    • no.34
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    • pp.75-113
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    • 2017
  • The purpose of fusion education is to acquire educational contents efficiently and gain a new worldview. To realize this purpose, I point out that it is urgent to provide common educational content and suggest "place experience" as common content for literature and geography. Local legends present a concrete space and a sharp confrontation with the human world, while shaping the tradition of a place's name. Place experience as common educational content enables a three-dimensional experience of a place that utilizes the characteristics of these local legends. The physical condition, human activity, and implied meaning of a place mediate the student's empirical understanding of folktales. The common area of "place experience" allows us to expect a stereotypical understanding of a learner's place by providing a literary context to learning contents that can flow from the existing geography subject to the simple provision of information. In addition, it facilitates learners' empirical understanding by providing actual and specific objects to learning contents, which can flow abstractly in the existing literature subject. Through this discussion, convergence education demonstrates educational significance by achieving educational efficiency through common educational content and enabling the formation of new thinking.

Time-dependent characteristics of viscous fluid for rock grouting (암반 그라우팅을 위한 점성유체의 시간의존 특성 분석)

  • Lee, Jong-Won;Kim, Ji-Yeong;Weon, Jo-Hyun;Oh, Tae-Min
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.24 no.6
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    • pp.465-481
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    • 2022
  • Rock grouting is important to improve the waterproof efficiency and mechanical strength of rock medium with joint for utilizing the underground rock space such as tunnel. The grouting materials typically has been used the cement materials, which represent Bingham fluid model. This model can express the relationship of viscosity and yield strength. In addition, it is dependent with elapsed time. The grouting injection performance can be deteriorated with an increase of viscosity and yield strength in the grouting process if the time dependence is ignored. Therefore, in this study, the characteristics of viscosity and yield strength were investigated according to water-cement ratio and time dependence in the laboratory test. Numerical simulation was carried out to investigate the grouting performance according to the time dependence of characteristics in terms of the viscosity model. Given the results, the grouting injected distance and cumulative grout volume were significantly decreased when the time dependence of grouting material was considered. This study, considering the characteristics according to the time dependence of viscosity and yield strength, will be meaningful to the design of grouting injection in field applications.

A Study on the Frictional Resistance Chracteristics of Pressurized Soil Nailing Using Rapid Setting Cement (초속경 시멘트를 사용한 가압식 쏘일네일링의 주입시간에 따른 마찰저항특성에 관한 연구)

  • Lee, Arum;Shin, Eunchul;Lee, Chulhee;Rim, Yongkwan
    • Journal of the Korean Geosynthetics Society
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    • v.17 no.4
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    • pp.1-10
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    • 2018
  • Although the soil nailing method is generally used as a gravity grouting, the development and application of pressurized grouting method has recently increased to address the problem of joint generation and filling due to grouting. Pressurized grouting of the soil nailing method is generally used in combination with ordinary portland cement and water. In the field, the cement is mixed with the rapid setting cement to reduce curing time because ordinary portland cement takes more than 10 days to satisfy the required strength. In this study, uniaxial compression tests and laboratory tests were carried out to confirm the efficiency of the grouting material according to the mixing ratio of rapid setting cement. The mixing ratio of 30% grouting satisfies the required strength within 7 days and satisfies the optimum gel time. As a result of the laboratory test with granite weathered soil, the reinforcing effect was confirmed to be 1.5 times as compared with the gravity type at an injection time of 10 seconds and a strain of 15%. The friction resistance increases linearly with the increase of the injection time, but it is confirmed that the friction resistance decreases due to the hydraulic fracturing effect at the injection time exceeding the limit injection pressure. Numerical analysis was performed to compare the stability of slopes not reinforced with slopes reinforced with gravity and pressurized soil nailing.

An Economic Ripple Effect Analysis of National Science & Technology Information Service : Focusing An Input-Output Analysis (국가과학기술지식정보서비스의 경제적 파급효과에 관한 연구 : 산업연관분석을 중심으로)

  • Park, Sung-Uk
    • Journal of Korea Technology Innovation Society
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    • v.21 no.4
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    • pp.1296-1312
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    • 2018
  • The wave of the Fourth Industrial Revolution was spreaded in Moon Jae-in Government. The efficiency of the R&D budget of government began to pay attention, the role of the National Science & Technology Information Service (NTIS) which provides all national R&D information in real time World's first R&D information portal has been emphasized. NTIS provides information on national R&D projects with their participating researchers, outcomes, and facilities & equipment through of information from each ministry and institution. NTIS supports to build science and technology policies, to enable transparent and efficient management of national R&D projects and to promote joint utilization of the R&D data among researchers and industrial utilization of the R&D data. NTIS provides since 2005. In this paper, I have analyzed the economic ripple effect of NTIS using the Input-Output model technique based on the input-output tables published by the Bank of Korea. When I set the NTIS R&D budget (about 120M$ for the last 13 years) as input coefficients, the effect on production inducement, value added inducement and employment inducement was analyzed by 211M$, 100M$ and 1,882 respectively.

Seq2Seq model-based Prognostics and Health Management of Robot Arm (Seq2Seq 모델 기반의 로봇팔 고장예지 기술)

  • Lee, Yeong-Hyeon;Kim, Kyung-Jun;Lee, Seung-Ik;Kim, Dong-Ju
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.12 no.3
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    • pp.242-250
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    • 2019
  • In this paper, we propose a method to predict the failure of industrial robot using Seq2Seq (Sequence to Sequence) model, which is a model for transforming time series data among Artificial Neural Network models. The proposed method uses the data of the joint current and angular value, which can be measured by the robot itself, without additional sensor for fault diagnosis. After preprocessing the measured data for the model to learn, the Seq2Seq model was trained to convert the current to angle. Abnormal degree for fault diagnosis uses RMSE (Root Mean Squared Error) during unit time between predicted angle and actual angle. The performance evaluation of the proposed method was performed using the test data measured under different conditions of normal and defective condition of the robot. When the Abnormal degree exceed the threshold, it was classified as a fault, and the accuracy of the fault diagnosis was 96.67% from the experiment. The proposed method has the merit that it can perform fault prediction without additional sensor, and it has been confirmed from the experiment that high diagnostic performance and efficiency are available without requiring deep expert knowledge of the robot.

Application of Geospatial Information Utilization System using Unmanned Aerial Image (무인항공 영상을 이용한 공간정보 응용 시스템 활용 방안)

  • Lee, Keun-Wang;Park, Joon-Kyu
    • Journal of Digital Convergence
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    • v.17 no.2
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    • pp.201-206
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    • 2019
  • Korea is constructing geospatial information application system for geospatial information utilization, but it is trying to establish a system for joint use of geospatial information system centering on Ministry of Land Transport and Transport due to the problem of sharing. The purpose of this study is to investigate and analyze the geospatial information application system operated by local governments, and to suggest the application of geospatial information application system using unmanned aerial images. As a result of the research, it was found that the functions of existing spatial information application system are concentrated on the public services and it is difficult to share and utilize data between administrative departments. In addition, the utilization of the system using unmanned aerial image has been suggested, and additional functions such as vector display, area calculation, and report generation have been derived to improve the usability of geospatial information application system. If additional functions of spatial information application system are added through further studies in the future, it will be possible to use it as a basic data of field survey and policy decision in related fields. And non-experts will be able to improve the efficiency of work by utilizing highly accurate geospatial information in various fields.