• Title/Summary/Keyword: Self-Sufficient

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Design Study of LAR Tokamak Reactor with a Self-consistent System Analysis Code

  • Hong, B.G.;Lee, D.W.;Kim, S.K.;Kim, D.H.;Lee, Y.O.;Hwang, Y.S.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.314-314
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    • 2010
  • The design of the blanket and shield play a key role in determining the size of a reactor since it has an impact on the various reactor components. The blanket should produce enough tritium for tritium self-sufficiency and the shield should provide sufficient protection for the superconducting TF coil. Neutronic optimization of the blanket and the shield is necessary, and we coupled the system analysis with a neutronic calculation to account for the interrelation of the blanket and shield with the plasma performance of a reactor system in a self-consistent manner. By using the coupled system analysis code, the operational space for a low aspect ratio (LAR) tokamak reactor with a superconducting toroidal field (TF) coil is investigated with an spect ratio in the range of 1.5 - 2.5. The minimum major radius which satisfies all the physics and engineering requirements increases with the magnetic field at the magnetic axis. A required inboard shield thickness is mainly determined by the requirement on the protection of the TF coil against radiation damage. It is shown that to have a fusion power bigger than 3,000 MW in the LAR tokamak with a superconducting TF coil, a major radius bigger than 4.0 m is required.

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Self-Supervised Long-Short Term Memory Network for Solving Complex Job Shop Scheduling Problem

  • Shao, Xiaorui;Kim, Chang Soo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.8
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    • pp.2993-3010
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    • 2021
  • The job shop scheduling problem (JSSP) plays a critical role in smart manufacturing, an effective JSSP scheduler could save time cost and increase productivity. Conventional methods are very time-consumption and cannot deal with complicated JSSP instances as it uses one optimal algorithm to solve JSSP. This paper proposes an effective scheduler based on deep learning technology named self-supervised long-short term memory (SS-LSTM) to handle complex JSSP accurately. First, using the optimal method to generate sufficient training samples in small-scale JSSP. SS-LSTM is then applied to extract rich feature representations from generated training samples and decide the next action. In the proposed SS-LSTM, two channels are employed to reflect the full production statues. Specifically, the detailed-level channel records 18 detailed product information while the system-level channel reflects the type of whole system states identified by the k-means algorithm. Moreover, adopting a self-supervised mechanism with LSTM autoencoder to keep high feature extraction capacity simultaneously ensuring the reliable feature representative ability. The authors implemented, trained, and compared the proposed method with the other leading learning-based methods on some complicated JSSP instances. The experimental results have confirmed the effectiveness and priority of the proposed method for solving complex JSSP instances in terms of make-span.

Brace-type shear fuses for seismic control of long-span three-tower self-anchored suspension bridge

  • Shao, Feifei;Jia, Liangjiu;Ge, Hanbin
    • Structural Engineering and Mechanics
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    • v.81 no.2
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    • pp.147-161
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    • 2022
  • The Brace-Type Shear Fuse (BSF) device is a newly proposed steel damper with excellent cumulative ductility and stable energy dissipation. In consideration of the current situation where there are not many alternatives for transversal seismic devices used in long-span three-tower self-anchored bridges (TSSBs), this paper implements improved BSFs into the world's longest TSSB, named Jinan Fenghuang Yellow River Bridge. The new details of the BSF are developed for the TSSB, and the force-displacement hysteretic curves of the BSFs are obtained using finite element (FE) simulations. A three-dimensional refined finite element model for the research TSSB was established in SAP2000, and the effects of BSFs on dynamic characteristics and seismic response of the TSSB under different site conditions were investigated by the numerical simulation method. The results show that remarkable controlling effects of BSFs on seismic response of TSSBs under different site conditions were obtained. Compared with the case without BSFs, the TSSB installed with BSFs has mitigation ratios of the tower top displacement, lateral girder displacement, tower bending moment and tower shear force exceeding 95%, 78%, 330% and 346%, respectively. Meanwhile, BSFs have a sufficient restoring force mechanism with a minor post-earthquake residual displacement. The proposed BSFs exhibit good application prospects in long-span TSSBs.

An Economic Perspective on Food Security

  • Seung-Ryong Yang
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2022.10a
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    • pp.9-9
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    • 2022
  • The concept of food security has gained increasing attention during the food crisis period between 2006 and 2011. According to the FAO, food security is defined as an access by all people at all times to the food needed for healthy and active life. Achieving food security means that sufficient food is available, food supply is relatively stable, and those in need of food can afford food at a reasonable cost. After a short period of stable food prices the world is facing another food crisis due mainly to the COVID-19 pandemic and the Russian invasion over Ukraine. Food security has re-emerged as an urgent problem to the world. There have been two conflicting opinions about how to achieve food security. Agricultural exporting countries insist diversification of food sources and freer trade on the top of domestic self-reliance. On the other hand, food importing countries emphasize self-sufficiency of major food crops. This study investigates whether domestic agricultural production contributes to strengthening food security. The panel data analysis shows that the increase in food self-sufficiency raises the Global Food Security Index and lessens the probability of food riots, while lower import tariffs (implying freer trade) do not. Some related issues are discussed accordingly.

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An Exploratory Study on Late Schooler′s Health Concept and Health Behavior (학령후기 아동의 건강개념 및 건강행위에 관한 서술적 연구)

  • Lee Ji Won
    • Child Health Nursing Research
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    • v.5 no.1
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    • pp.18-26
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    • 1999
  • The purpose of this study was to explore the late schooler's health concept and health behavior. The research was a descriptive method using a self-report questionaire which include semi open-ended questions. the subjects were 458 late schooler's from 4 to 6 grade. The results were as follows : 1. Perceived health concepts were ‘having no illness’ ‘having normal physical feature and strength’ ‘eating food well’ ‘take exercise’ ‘having a bright mind’ ‘having good interpersonal relationships’‘having strong will’ ‘recovering well’. 2. Perceived health behaviors to maintain health were ‘taking proper exercise’ ‘eating proper food’ ‘maintaining cleanliness’ ‘taking sufficient rest and sleep’ ‘having a vigor life and positive thought’ ‘having good interterpersonal relationships’ ‘receiving health check and immunization’. 3. Health behaviors carried out at present were ‘taking proper exercise’ ‘eating proper food’ ‘having a vigor life and positive thought’ ‘receiving health check an immunization’ ‘taking supplementary drugs’ ‘having a regular life’ ‘maintaining cleanliness’ ‘maintaining warmth’. 4. Perceived causes of illness were ‘taking inproper food’ ‘uncleanliness’ ‘insufficient warmth or environment’ ‘lack of exercise or overexertion’ ‘irregular life habits’ ‘contact with germs’ ‘mental stress’. 5. Perceived treatments of illness were ‘having sufficient rest and sleep’ ‘mental relaxation’ ‘eating food’ ‘ maintinging cleanliness’ ‘ maintaining warmth’ ‘taking supplementary drug’ ‘receiving medical treatment’.

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The transition of noteworthy rice diseases and their control in Korea

  • Park J. S.
    • Korean journal of applied entomology
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    • v.4
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    • pp.1-6
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    • 1965
  • In Korea the most important plant industry is the rice-growing but she has not yet attained self-sufficiency with regard to rice which is the basic food of Korean. In the past, various measures of increasing rice production have been tried with some success but the increasing rate of did not show the sufficient result. Judging from experiences, disease control may be the most important factor which has influence on increasing of rice production in Korea. During the past 60 years three periods divided by the transition of rice diseases were noted, and especially the recent transition attracted much attention . That is, sheath blight and stripe which were minor diseases in the past have promptly spread all over the country and caused heavy losses to rice plant, and also local outbreak of bacterial leaf blight and dwarf were noticed. Various environmental factors are related to such transition of rice disease. Above all, cultivated varieties susceptible to these diseases, increase of application of nitrogenous fertilizer, earlier transplanting and density of transplanting are considered to be lucre closely related to the development of these diseases and successive development of blast. On the other hand. application of forage fungicides such as organic mercury compounds specific to blast contributed to reduce prevalent area if blast in spite of wide spread of susceptible varieties and increase of application of nitrogenous fertilizer. These facts were confirmed by Korean investigators At the present which various diseases to control coexist in the same region, no one variety resistant to all of these diseases is provided and cultural practices for the control of these diseases often do not produce sufficient yield of rice. it is emphasized that a role of pesticides is very great.

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Manufacturing of Wedge-type Light Guide Plates for Large Liquid Crystal Displays (대형 LCD용 쐐기형 도광판 제조공정에 대한 연구)

  • Kim, Min-Soo;Kim, Jangseob;Hong, Jun-Ho;Shin, Dongwon
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.4
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    • pp.30-35
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    • 2020
  • The light guide plate (LGP) provides a surface light source on the back of the liquid crystal display (LCD), which is not self-emitting; thus, it is an essential component of display units requiring sufficient brightness. To maximize the light-emitting effect of an LGP, enough incident light, from the light source, should enter into its side. However, the current trend in LCD panels is represented by larger and thinner screens and this smaller thickness prevents the accordingly thin LGPs from providing sufficient brightness. This paper proposes a process for manufacturing wedge-type LGPs, which might increase the amount of incident light and, consequently the surface light emission, for applications in large LCDs. The proposed method was validated by building a dedicated manufacturing machine and performing illuminance experiments on the fabricated LGP.

POSITIVE SOLUTIONS FOR A NONLINEAR MATRIX EQUATION USING FIXED POINT RESULTS IN EXTENDED BRANCIARI b-DISTANCE SPACES

  • Reena, Jain;Hemant Kumar, Nashine;J.K., Kim
    • Nonlinear Functional Analysis and Applications
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    • v.27 no.4
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    • pp.709-730
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    • 2022
  • We consider the nonlinear matrix equation (NMEs) of the form 𝓤 = 𝓠 + Σki=1 𝓐*iℏ(𝓤)𝓐i, where 𝓠 is n × n Hermitian positive definite matrices (HPDS), 𝓐1, 𝓐2, . . . , 𝓐m are n × n matrices, and ~ is a nonlinear self-mappings of the set of all Hermitian matrices which are continuous in the trace norm. We discuss a sufficient condition ensuring the existence of a unique positive definite solution of a given NME and demonstrate this sufficient condition for a NME 𝓤 = 𝓠 + 𝓐*1(𝓤2/900)𝓐1 + 𝓐*2(𝓤2/900)𝓐2 + 𝓐*3(𝓤2/900)𝓐3. In order to do this, we define 𝓕𝓖w-contractive conditions and derive fixed points results based on aforesaid contractive condition for a mapping in extended Branciari b-metric distance followed by two suitable examples. In addition, we introduce weak well-posed property, weak limit shadowing property and generalized Ulam-Hyers stability in the underlying space and related results.

The Relationship Between the Quality of Surface Layer of Concrete Floor and the Defect of Self-Leveling Material - Evaluation Method about Surface Layer Quality of Concrete Floor Groundwork Corresponding to Defect in Self-leveling Material (Part II) - (콘크리트 표층부 품질이 SL재의 하자에 미치는 영향 - SL재의 하자 발생에 영향을 미치는 콘크리트 표층부의 품질 평가방법(II) -)

  • Kim, Doo-Ho;Choi, Soo-Kyung
    • Journal of the Korea Institute of Building Construction
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    • v.7 no.4
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    • pp.125-132
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    • 2007
  • The use of Self-Leveling material is increasing recently. This paper assesses the quality of surface layer of concrete floor when Self-Leveling material is defective. The paper shows how to predict the defect of SL material before construction begins. The relationship between the quality of surface layer of concrete floor and the defect of SL material was determined and the quality of surface layer of concrete floor was then estimated. The relations between the quality of surface layer and the defect of SL material were determine considering surface strength, moisture, and consistency of surface layer. Absorbing amount was used as the indicator of consistency and the absorbing amount of test material was measured. Then the relations between the test material and surface strength were determined. Generally concrete floor with greater consistency has greater surface strength, however in this study, we hound that high impact concrete floor could have lower surface strength as the consistency gets bigger. The relations between the level of defect occurred in SL material and the quality of surface layer were examined and we clarified that the surface layer with lower consistency gets higher possibility to occur exfoliation in early stage, one or two weeks after constructing SL material. When the consistency is sufficient, the occurring situation of defect depends upon the moisture of surface layer. Little amount of moisture gets higher possibility not to occur the defect. As the amount increases, fissure generates and early exfoliation may occur. In addition, the level of fissure is highly related with the surface strength.

A Study on the Present Situation of Landscape Management System through Analysis of the Landscape Review Results - Focused on Jeju Special Self-Governing Province Landscape Review- (경관 심의결과 분석을 통한 경관관리제도의 현황에 대한 연구 - 제주특별자치도 경관 심의를 중심으로 -)

  • Park, Hye-Jung;Park, Chul-Min
    • Journal of the Korean Institute of Rural Architecture
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    • v.20 no.4
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    • pp.9-17
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    • 2018
  • The purpose of the study is to suggest ways to improve the Landscape Review system and Landscape Management System of Jeju Special Self-governing Province through Analysis of the Landscape Review Results and Jeju Special Self-governing Ordinance. For this purpose, the research methods were reviewed for preliminary study and reviewing the laws and ordinances related to landscape, and 318 cases of landscape review, which have been implemented since 2010, were analyzed by item by item along with the result of the review. The main results of the analysis are as follows. First, Jeju Special Self-governing Province, which currently operates an enhanced ordinance of development project review, is experiencing problems such as building the wrong construction projects due to the weak legal basis for follow-up management after landscape Review. Second, Jeju Special Self-governing Province expects efficient management of the province through expansion of the scope of the landscape review. Third, the current status of the decisions by the Landscape review showed that 57.7% of the bills passed, the lowest at 41.9% for the development projects. Fourth, analysis of the landscape review contents by categorization by item showed that ' Landscape Control Guideline' and 'Document not completed' are relatively high. Thus, eight years have passed since the start of the Landscape Management System and the Landscape Review, but systematic institutional stability is not sufficient, so it is necessary to make the Landscape Control Guideline easier to understand.