• Title/Summary/Keyword: consolidation efficiency

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The site application with 700kg/$\textrm{cm}^2$ high strength concrete (700kg/$\textrm{cm}^2$ 고강도 콘크리트의 현장적용)

  • 권영호;박정국;이보근;박칠림
    • Proceedings of the Korea Concrete Institute Conference
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    • 1993.10a
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    • pp.124-131
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    • 1993
  • A successful site application with 700kg/$\textrm{cm}^2$ ultra-high strength concrete was made by research team of Daewoo Institute of Construction Technology in Jinhae. Trial mixings of concrete, the productivity of batcher plant, the elapsed time and the pumpability had been investigated for the site condition, before the site application. As results, the efficiency of production by automatic batcher plant systems was improved and the method of quality control was estabilished for the security of fluidity due to the elapsed time, the pumping and consolidation and so on. The concrete strength cores as well as cylinders was showed more than 700kg/$\textrm{cm}^2$ for the required age. And this study would be provided valuable data base for the practical utilization of high strength concrete. Further, this study would be given new possibilities of high rise RC constructions.

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A Heuristic Time Sharing Policy for Backup Resources in Cloud System

  • Li, Xinyi;Qi, Yong;Chen, Pengfei;Zhang, Xiaohui
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.7
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    • pp.3026-3049
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    • 2016
  • Cloud computing promises high performance and cost-efficiency. However, most cloud infrastructures operate at a low utilization, which greatly adheres cost effectiveness. Previous works focus on seeking efficient virtual machine (VM) consolidation strategies to increase the utilization of virtual resources in production environment, but overlook the under-utilization of backup virtual resources. We propose a heuristic time sharing policy of backup VMs derived from the restless multi-armed bandit problem. The proposed policy achieves increasing backup virtual resources utilization and providing high availability. Both the results in simulation and prototype system experiments show that the traditional 1:1 backup provision can be extended to 1:M (M≫1) between the backup VMs and the service VMs, and the utilization of backup VMs can be enhanced significantly.

Experinces with Soft Clay Improvement in the Bangkok plain

  • O, P-R
    • Proceedings of the Korean Geotechical Society Conference
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    • 1997.06c
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    • pp.1.1-16
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    • 1997
  • This lecture summarizes the progress of the development of the different ground improvement techniques in Bangkok Plain and is reviewed in relation to the extensive deep wen pumping and the resulting piezometric drawdown at deeper depths. Case records of test embankments with sand drains, sand wicks and PVD are presented to inustrate the effectiveness of different types of vertical drains with surcharge. The use of prefsbicated drain seems more superior than the other types of sand drain. Construction of test embaxlkment, criteria for PVD selection and relevant laboratory testing techniques are discussed for formulating the specif'ication. Alternative teckuuque, such in, the use of deep chemical mixing is reviewed in terms of the efficiency of cement, lime and flyash as additive. Vacuum pre-loading with surcharge and elctro- osmotic consolidation are also explored as possible tectmiques to improve the engineering properties of soft Bangkok clay.

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Comparison on the Performance of Soil Improvement in Thick Soft Ground Using Single-Core and Double-Core PBD (단일 및 이중 코어 PBD에 의한 대심도 연약지반 개량 효과에 관한 비교연구)

  • Yang, Jeong-Hun;Hong, Sung-Jin;Kim, Hyung-Sub;Lee, Woo-Jin;Choi, Hang-Seok
    • Journal of the Korean Geotechnical Society
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    • v.25 no.8
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    • pp.33-45
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    • 2009
  • The conventional single-core PBDs have been widely used in order to accelerate consolidation settlement of soft grounds. When using the single-core PBD in a thick clay deposit, a delay of consolidation may occur due to high confining pressure in the thick deposit and necking of drains. This study is to compare the performances of soil improvement by the single-core and double-core PBD installed at a site in Busan New Port which exhibits approximately a 40m-thick clay layer. An in-situ test program was performed at the test site where a set of the double-core PBDs and single-core PBDs were installed to compare the efficiency of each drain. In addition, the discharge capacity of each PBD has been measured using the modified Delft Test. A series of laboratory tests for estimating in-situ soil properties have also been performed in order to obtain input parameters for a numerical program ILLICON. The discharge capacity of the double-core PBD is higher than that of the single-core PBD in the modified Delft Test. However it is observed from the comparative in-situ test and numerical analysis that there is no difference in the performance of ground improvement between the two drain systems. This discrepancy comes from the fact that the amount of water released during consolidation in most common field conditions is much smaller than the capacity of even the single core PBD. And thus, considering actual field conditions, it can be concluded that the single-core PBD has enough discharge capacity even in the thick clay deposit such as this test site.

Analysis of Efficiency of Suction Board Drain Method by Step Vacuum Pressure (단계석션압 조건에 따른 석션보드드레인 공법의 효율 분석)

  • Kim, Ki-Nyun;Han, Sang-Jae;Kim, Soo-Sam
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.6C
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    • pp.321-329
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    • 2008
  • In this study, a series of column test as a way in order to make up for the weakness point of the conventional acceleration method were conducted to both propose the suction board drain method and grapes the specific improvement character of this method as a result of a sort of plastic drain board and a phase of vacuum pressure conditions. On this occasion, the study focused on computing the effective factors of the fittest Suction board drain method affected by each condition through confirming the settlement generated during the test, the water content reduction and stress increase effect occurred arising from the test, and the ratio of consolidation related to the improvement period. In accordance with the shape of core and that whether the core is attached to the filter(pocket or adhesion), the castle type of adhesion and the column type of pocket are more efficient than the others as a consequence of the test to find out the improvement effect depending on each drainage such as a castle type, coil type, harmonica type, column type of pocket and a castle of the adhesion. In case of the step suction pressure, the shorter the period of $-0.8\;kg/cm^2$ as a final step of the suction pressure is, the better the improvement is. In addition, the correlation between degree of consolidation per each suction pressure level and duration of application was drawn as a curve and the point of inflection on this curve was provided to determine the duration period to maximize the consolidation.

A Study on the Efficiency of Import-Export Logistics through Advance Presentation of Vessel Manifest (해상적하목록 사전제출을 통한 수출입물류 효율화 방안에 관한 연구)

  • Kim, Yong-Jin;Seo, Dong-Gyun
    • Journal of Korea Port Economic Association
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    • v.27 no.2
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    • pp.275-296
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    • 2011
  • The purpose of this study was to examine ways of ensuring the efficiency and stability of import-export logistics in our country by introducing an advance presentation system of vessel manifest. This advance presentation system of vessel manifest has already been introduced in the United States, the EU and China whom our country has actively traded with, and the reinforcement of logistics security is a global trend. Under the circumstances, the introduction of the advance presentation system of vessel manifest is required to assist exporters to properly respond to changing trade practices as early as possible, and it's also necessary to exercise stricter control over an import criminal cargo. Our country should urgently introduce the advance presentation system of vessel manifest that is up to global standard, and the establishment of an internet based manifest consolidation and presentation system and the introduction of an export inspection system of port of loading are requested as well. If all the systems are introduced and work properly, that will make a great contribution to the efficiency of import-export logistics in our country.

Efficiency Analysis for Certified Integrated Logistics Warehousing firms Using DEA (DEA를 이용한 종합물류인증기업의 효율성 분석 : 물류창고업종을 중심으로)

  • Kang, Da-Yeon;Lee, Ki-Se
    • Journal of Navigation and Port Research
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    • v.43 no.4
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    • pp.256-263
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    • 2019
  • The trade volume of Northeast Asian countries is increasing and with the advent of the 4th revolutionary era, minimizing the logistics costs of firm is becoming an important competitive factor. With respect to this, in 2006, the government introduced a certified Integrated logistics firm system to improve the competitiveness of local logistics firms and reduce the logistics costs of firms. They argued that the certified Integrated logistics firm system increased the reliability of logistics firms and increased the efficiency of the logistics industry. On the other side, they argue that the system puts a burden on firms and becomes a big business-oriented market consolidation. This study analyzed the efficiency of Warehousing firms using DEA model. The CCR, BBC efficiency and RTS (return to scale) of 15 Warehousing firms were evaluated. This study also suggested the Warehousing firms which can be benchmarked based on analyzed information.

Review of the KCAB International Arbitration Rules, Recently Revised, in Comparison with the Revised ICC Arbitration Rules (대한상사중재원 국제중재규칙의 개정 동향 - ICC 중재규칙의 개정과 비교하여 -)

  • Park, Won-Hyung
    • Journal of Arbitration Studies
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    • v.22 no.2
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    • pp.159-176
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    • 2012
  • The Korean Commercial Arbitration Board (KCAB) recently revised its International Arbitration Rules in a way that reflects its efforts to advance its procedures, leading directly to improved competitiveness as an arbitration institute. Apart from certain limitations, the KCAB's international arbitration rule revision introduced several new arbitration mechanisms, including fast-track arbitration and an empowered administrative office. The International Chamber of Commerce (ICC) released a revised set of arbitration rules (ICC Arbitration Rules), which have been said to be probably the most consulted-on arbitration rules ever. Even though the changes codify existing ICC court practice and add to the 1998 rules only provisions felt necessary in light of input from the users of arbitration, some of the changes will have huge implications for future aspects of arbitration mechanisms, especially those of KCAB. Although it remains to be seen what impact the ICC Arbitration Rules will have in practice, the new rules have been well received by the arbitration community and represent a modern set of provisions consistent with the current needs of the users of international arbitration. That is why, here in the Korean arbitration environment, further research is needed on the possibilities of introducing several elements of the revised ICC Arbitration Rules to improve the speed and cost efficiency of international arbitration.

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Evaluation on Drainage Capacity of Cylindrical Drain with Different Core Shapes (코아형식에 따른 원통형 배수재의 구멍막힘에 의한 배수능력 평가비교)

  • Lee Kwang-Yeol;Nugroho David Setiawan;Yun Sung-Tae;Ji Ho-Yeol
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.311-315
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    • 2006
  • Various core shapes of cylindrical drains are used for accelerating primary consolidation for soft clay deposits, but serious harmful disadvantages on drainage capacity may occur on cylindrical drains due to confining Pressure when they are installed in that soil. In this study, two different core shapes of cylindrical drain are used to evaluate the drainage capacity with consideration of clogging effects on their filter jackets for an applied confining pressure. Column tests with radial drainage system were conducted under confining pressure of 50 kPa for 13 days. Two parameters which are discharge and accumulated volume of water drained were measured as the time elapsing. From this experimental study, the results showed that at the Initial stage before the clogging developed enough, the cylindrical drain with angular-type-plastic-core could produce discharge twice higher (maximum) than those with round-type. After 13 days had passed on, cylindrical drain with angular-type-plastic-core could produce discharge only 20% higher than those with round-type one. Eventually, there is a possibility that the efficiency of using angular-type-cylindrical-drain will be similar to the round-type one as the clogging develops more.

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Policy Issues for Integrated Approach to Rural Regional Development (농어촌지역개발의 종합적 접근을 위한 정책 과제)

  • 임상봉
    • Journal of Korean Society of Rural Planning
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    • v.3 no.2
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    • pp.90-101
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    • 1997
  • The objectives of the study are to identify the issues and problems encountered in Korea's current integrated rural regional development(IRRD) program and to suggest policy remedies to cope with them. Secondary data and materials ate mainly used for the study. Since the mid-1980s, rural settlement planning has been carried out in the Republic of Korea, In the planning process,'scale of economy'perspectives and settlement policy have been emphasized for increasing the efficiency of investment. During the 1990s, rural settlement and major village development projects have been implemented under the rural structure transformation programs. Agricultural structure adjustment projects for land consolidation and sizable farming have been separated from the rural settlement and mojor village development projects. Based on the evaluative analysis for the rural structure transformation policy and program, some problematic issues were raised as follows: (a) lack of integrative control function in the program'(b) weak linkage between living environment improvement and agricultural development projects: and (c) lack of comprehensive village development planning and implementation system. The policy issues to solve the problems were suggested as follows: (a) adoption of bottom-up approach in new IRRD planning and project system : (b) projection of comprehensive development planning and project at the village level; and (c) introduction of new regional agriculture development projects such as direct payment system for farming in less favorable areas and organic farming.

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