• Title/Summary/Keyword: Core stability

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Development of the Local Area Design Module for Planning Automated Excavator Work at Operation Level (자동화 굴삭로봇의 운용단위 작업계획수립을 위한 로컬영역설계모듈 개발)

  • Lee, Seung-Soo;Jang, Jun-Hyun;Yoon, Cha-Woong;Seo, Jong-Won
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.1
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    • pp.363-375
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    • 2013
  • Today, a shortage of the skilled operator has been intensified gradually and the necessity of an earthwork in extreme environment operators are difficult to access is increasing for the purpose of resource development and new living space creation. For this reason, an effort to develop an unmanned excavation robot for fully automated earthwork system is continuing globally. In Korea, a research consortium called 'Intelligent Excavation System' has been formed since 2006 as a part of Construction Technology Innovation Program of Ministry of Land, Transport and Maritime Affairs of Korea. Among detailed technologies of the Task Planning System is one of the core technologies of IES, this paper explains research and development process of the Local Area Design Module, which provides informatization unit to create automated excavators' work command information at operation level such as location, range, target, and sequence for excavation work. Designing of Local Area should be considered various influential factors such as excavator's specification, working mechanism, heuristics, and structural stability to create work plan guaranteed safety and effectiveness. For this research, conceptual and detail design of the Local Area is performed for analyzing design element and variable, and quantization method of design specification corresponding with heuristics and structural safety is generated. Finally, module is developed through constructed algorithm and developed module is verified.

Study on Hot Water Immersion Treatment for Control of Meloidogyne spp. and Pratylenchus spp. in a Ginger, Zingiber officinale (생강에서 뿌리혹선충과 뿌리썩이선충의 사멸을 위한 온탕침지처리 연구)

  • Cho, Donghun;Park, Kyonam;Kim, Yangho;Koh, Kyung-bong;Park, Youngjin
    • Korean journal of applied entomology
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    • v.56 no.2
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    • pp.171-177
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    • 2017
  • Plant parasitic nematodes, Meloidogyne and Pratylenchus spp., are mostly detected in imported bulbs and tubers including a ginger, Zingiber officinale in Korea by quarantine inspection. However, there is little information on hot water immersion treatment (HWIT) for control of exotic nematodes, which induce economic loss by discard or send back to exporter, in imported gingers. In here, we determined that mortality of two plant parasitic nematodes and thermal stability of ginger. Meloidogyne and Pratylenchus spp. were completely killed at $48^{\circ}C$ and $49^{\circ}C$ for 30 sec by HWIT. Thermal conduction of Z. officinale to reach a target temperature as $50^{\circ}C$ take 10~32 min and 6~16 min for core and inner 5 mm region from surface, respectively. When ginger exposed at $51^{\circ}C$ for 30 min, growth of Z. officinale was not affected by heat treatment compared with control. Based on these results, HWIT at $51^{\circ}C$ for 30 min completely killed artificially infected juveniles of Meloidogyne spp. in Z. officinale. Therefore, this condition for HWIT will be used as fundamental information on phytosanitory to kill two plant parasitic nematodes without damage on ginger.

A Study of Chinese Peaceful Rise and East Asian Regional Cooperation (중국의 평화적 부상과 동아시아 지역협력 연구)

  • Shong, Il-Ho;Lee, Gye-Young
    • International Commerce and Information Review
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    • v.14 no.3
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    • pp.75-96
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    • 2012
  • China will replace the global governance of the 21st century in 2050. The rise of China provide the Chinese development model to other developing countries. There are positive element and disability element in China's 'peaceful rise' strategy at the same time. Success of the reform and opening up, market liberalization, economic interdependency, economic globalization, stability of ruling power, consolidation of one-party rule and soft power increase are the promotions of peaceful rise. China's rise as a power nation begins by regaining the superpower status in East Asia. East Asia is a lebensraum assuring a continuing growth to China. For this lebensraum, China shows an interest in institutionalization of regional economic cooperation. The core values of ASEAN, namely the mutual respect, harmonious coexistence, co-prosperity, egalitarianism and pluralism are in conform to China's policy of harmonious world and peaceful coexistence. Through this common value the tension in East Asia will be alleviated. By the regional hegemony strategy based on soft power and economic success, China will try to regain the past glorious position. Attaining status as a coordinator of the world rule will be based on the success of the East Asian strategy. Korea and other neighboring countries will be the best beneficiary countries of the China's rise strategy. China's rising strategy will have a profound effect on neighboring countries especially, Korea. The scale of the movement of goods, labor, and capital between the two countries will become much larger than present. Through regional trade agreements, economic interdependency between Korea and China will increase.

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An Experimental Study on the Optimum Mix Design and Site Application Case of Soil Mixing Wall for Trench Stability (구벽안정성을 위한 SMW 최적배합비 및 현장적용 사례에 관한 연구)

  • Kwon, Yeong-Ho
    • Journal of the Korea Concrete Institute
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    • v.27 no.4
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    • pp.419-426
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    • 2015
  • The purpose of this study is to investigate experimentally the optimum mix design and site application case of soil mixing wall (SMW) method which is cost-effective technique for construction of walls for cutoff wall and excavation support as well as for ground improvement before constructing LNG storage tank typed under-ground. Considering native soil condition in site, main materials are selected ordinary portland cement, bentonite as a binder slurry and also it is applied $1,833kg/m^3$ as an unit volume weight of native soil, Variations for soil mixing wall are as followings ; (1) water-cement ratio 4cases (2) mixing velocity (rpm) 3levels (3) bleeding capacity and ratio, compressive strength in laboratory and site application test. As test results, bleeding capacity and ratio are decreased in case of decreasing water-cement ratio and increasing mixing velocity. Required compressive strength (1.5 MPa) considering safety factors in site is satisfied with the range of water-cement ratio 150% below, and test results of core strength are higher than those of specimen strength in the range of 8~23% by actual application of element members including outside and inside in site construction work. Therefore, optimum mix design of soil mixing wall is proposed in the range of unit cement $280kg/m^3$, unit bentonite $10kg/m^3$, water-cement ratio 150% and mixing velocity 90rpm and test results of site application case are satisfied with the required properties.

Utilization of Information from International Observation Trials for the Introduction of New Crops: An Introduction of Azuki Bean Varieties from China to Thailand

  • Xin, Chen;Volkaert, Hugo;Chatwachirawong, Prasert;Srinives, Peerasak
    • Journal of Crop Science and Biotechnology
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    • v.11 no.1
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    • pp.51-56
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    • 2008
  • Azuki bean has never been commercially grown in Thailand, due in part to a lack of suitable varieties. A core collection of 114 azuki bean accessions, originally from different parts of China(northern, central, southern) representing the germplasm of Chinese land races, were evaluated in the experimental field of the Institute of Vegetable Crops, Jiangsu Academy of Agricultural Sciences, China from June to October 2004. The same experiment was repeated at Kamphaeng Saen campus of Kasetsart University, Thailand from February to May 2005. Yield, yield components, and agronomic traits were recorded in all accessions in order to identify certain genotypes for further investigation. The statistical parameters that were used as indicators of phenotypic variation were mean, coefficient of variability(CV), correlation coefficient(r), range, mean difference, and phenotypic clustering of the accessions. The results indicated that the azuki bean varieties planted in Kamphaeng Saen were shorter, earlier in growing duration, and lower in plant height, seed yield per plant, 100-seed weight, and pods per plant as compared to when they were grown in China. This discrepancy was caused largely by the combined effect of temperature, rainfall, and day length. The traits that were rather stable in both locations were branches per plant and seeds per pod. Azuki bean varieties from northern China showed higher response to the changing environments compared with those from central and southern China. Some agronomic traits showed high correlation coefficient between the environments in Thailand and China. The CV of agronomic traits in both locations were ranked in descending order as follows: seed yield per plant, pods per plant, branches per plant, plant height, 100-seed weight, seeds per pod, and growing duration. The CV of seeds per pod and branches per plant were almost the same in both locations. Yield per plant in China correlated well(r=0.75) with pods per plant, but not with the other traits. Based on their response to both environments, the azuki bean accessions can be broadly divided into four groups, viz. northern 1, northern 2, central, and southern. This implied that there was more diversity, but probably less stability among the accessions originating from northern China.

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Stratigraphical Research of the Quaternary Deposits in the Korean Peninsula (韓半島 第四紀 地層의 層序的 考察)

  • Lee, Dong-Young
    • The Korean Journal of Quaternary Research
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    • v.1 no.1
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    • pp.3-20
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    • 1987
  • With regard to the Quaternary formations in the Korean Peninsula, very few studies have been done specially from a stratigraphic viewpoint. The alluvial sediments filling in the valleys have often been considered as the only formation of Quaternary age (more precisely of the Holocone) and so the Pleistocene was regarded as an erosional or nondepositional episode. This is apparently evident from a quick look at the general geological maps of the Peninsula, which show a lithological sequence of Mesozoic or Paleozoic substrata immediately overlain by Holocene alluvium. Likewise, the Pleistocene period was described in terms of unconformity in most local or regional stratigraphical successions of the Peninsula. Recently several different types of Quaternary formation, besides the so-called Holocene alluvium in the valley plain have been found around the Peninsula. They consist of coastal deposits, marine or fluviatile terrace deposits, ancient valley fill deposits or slope deposits. Some parts of the volcanic sediments in Jeju Is. are also known as the Quaternary sequence. Thus the Quaternary deposits in the Peninsula are far more developed than previously known to gelolgists. Moreover the importance of Quaternary research became recently apparent in Korea due to the shortage of raw materials and to the policy of an optimum land-use. Advanced constructions and land reclamation have required more precise engineering parameters of loose materials and an estimation of land stability. This does not imply only the engineering, or the structural properties of the loose material, but at the same time the basic study of the sediments from the stratigraphical and environmental viewpoints has been necessary. In this connection, Quaternary outcrops specially along the coastal fringe of the Peninsula have been mapped, profiled and sampled for sedimentological, clay-mineralogical and palaeomagnetic studies. All these results are compiled for the core of the Quaternary stratigraphy of the Peninsula.

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A Grounded Theory Approach on Peoples' Adaptation Experience with Fibromyalgia Syndrome (섬유근통증후군 환자의 질병 적응경험에 관한 근거이론 연구)

  • Jeong, Chu-Yeong;Kim, Myung-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.12
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    • pp.381-393
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    • 2016
  • This was a qualitative study to explore and better understand the adaptation experience and processes of peoples with fibromyalgia syndrome (FMS), as well as to develop a substantive theory using the grounded theory method. There were 13 patients (12 females and 1 male) who received FMS treatment from Rheumatic Medicine outpatient department of one general hospital. The data were collected through an in-depth interview between January and May of 2014. Transcribed interview contents were analyzed by the grounded theory method of Corbin and Strauss (2008). As a result, a total of 98 concepts, 26 sub-categories, and 10 categories were identified through the open coding process. The process of adaptation experience showed 4 steps: perception of uncertainty and limited condition, evaluation of self-control possibility and determinations of expectations of life, searching and trying of strategies, as well as self-regulation. The 4 types of adaptation experience were expansionary, complacently, effusively and withering. The 'protective self-regulation' theory was derived from the core category of 'learning to self-regulation method'. Patients with FMS has repeatedly attempted these strategies of protective self-regulation in order to gain stability from uncertainty and limited condition of the disease. Based on these results, it is necessary to develop an educational program for patients and families which has appropriate nursing intervention strategies in accordance with the types of adaptation.

Modeling, Preparation, and Elemental Doping of Li7La3Zr2O12 Garnet-Type Solid Electrolytes: A Review

  • Cao, Shiyu;Song, Shangbin;Xiang, Xing;Hu, Qing;Zhang, Chi;Xia, Ziwen;Xu, Yinghui;Zha, Wenping;Li, Junyang;Gonzale, Paulina Mercedes;Han, Young-Hwan;Chen, Fei
    • Journal of the Korean Ceramic Society
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    • v.56 no.2
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    • pp.111-129
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    • 2019
  • Recently, all-solid-state batteries (ASSBs) have attracted increasing interest owing to their higher energy density and safety. As the core material of ASSBs, the characteristics of the solid electrolyte largely determine the performance of the battery. Thus far, a variety of inorganic solid electrolytes have been studied, including the NASICON-type, LISICON-type, perovskite-type, garnet-type, glassy solid electrolyte, and so on. The garnet Li7La3Zr2O12 (LLZO) solid electrolyte is one of the most promising candidates because of its excellent comprehensively electrochemical performance. Both, experiments and theoretical calculations, show that cubic LLZO has high room-temperature ionic conductivity and good chemical stability while contacting with the lithium anode and most of the cathode materials. In this paper, the crystal structure, Li-ion transport mechanism, preparation method, and element doping of LLZO are introduced in detail based on the research progress in recent years. Then, the development prospects and challenges of LLZO as applied to ASSBs are discussed.

Electrical Characteristics Measurement of Eddy Current Testing Instrument for Steam Generator in NPP (원전 증기발생기 와전류검사 장치의 전기적 특성 측정)

  • Lee, Hee-Jong;Cho, Chan-Hee;Yoo, Hyun-Joo;Moon, Gyoon-Young;Lee, Tae-Hun
    • Journal of the Korean Society for Nondestructive Testing
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    • v.33 no.5
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    • pp.465-471
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    • 2013
  • A steam generator in nuclear power plant is a heatexchager which is used to convert water into steam from heat produced in a nuclear reactor core, and the steam produced in steam generator is delivered to the turbine to generate electricity. Because of damage to steam generator tubing may impair its ability to adequately perform required safety functions in terms of both structural integrity and leakage integrity, eddy current testing is periodically performed to evaluate the integrity of tubes in steam generator. This assessment is normally performed during a reactor refueling outage. Currently, the eddy current testing for steam generator of nuclear power plant in Korea is performed in accordance with KEPIC & ASME Code requirements, the eddy current testing system is consists of remote data acquisition unit and data analysis program to evaluate the acquired data. The KEPIC & ASME Code require that the electrical properties of remote data acquisition unit, such as total harmonic distortion, input & output impedance, amplifier linearity & stability, phase linearity, bandwidth & demodulation filter response, analog-to-digital conversion, and channel crosstalk shall be measured in accordance with the KEPIC & ASME Code requirements. In this paper, the measurement requirements of electrical properties for eddy current testing instrument described in KEPIC & ASME Code are presented, and the measurement results of newly developed eddy current testing instrument by KHNP(Korea Hydro & Nuclear Power Co., LTD) are presented.

Studies on the Microencapsulation of ${\omega}-3$ Polyunsaturated Fatty Acid (${\omega}-3$계 지방산의 미세캡슬화에 관한 연구)

  • Kim, Chul-Hyun;Lee, Kyung-Wook;Baick, Seung-Chun;Kwak, Hae-Soo;Kang, Jong-Ok
    • Korean Journal of Food Science and Technology
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    • v.28 no.4
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    • pp.743-749
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    • 1996
  • This study was carried out to investigate the microencapsulatuion of ${\omega}-3$ fatty acid isolated from fish oil and to obtain fundamental information on the utilization of the ${\omega}-3$ fatty acid in the dairy foods field. To obtain the desirable microencapsulation efficiency, 1.5% agar and 0.5% gelatin were used as coating materials, and 0.5% SFAN 60 (HLB 4.5 value) was used to maintain the emulsion stability. The optimal mixing ratio of coating material to core material was 8:2 (w/w). The thermostability of microencapsulated product was not maintained above $60^{\circ}C$. Microencapsulation efficiency was kept at about 90% at $4^{\circ}C$ and $10^{\circ}C$ for 7 days storage at various temperatures. At $20^{\circ}C$ and $30^{\circ}C$, however, about 80% microencapsulatuion efficiency was obtained for 3 days storage. About 80.57% microcapsule was destroyed by 1%> pepsin solution at $37^{\circ}C$ for 10 min.

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