• Title, Summary, Keyword: Reversibility

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ON REVERSIBILITY RELATED TO IDEMPOTENTS

  • Jung, Da Woon;Lee, Chang Ik;Lee, Yang;Park, Sangwon;Ryu, Sung Ju;Sung, Hyo Jin;Yun, Sang Jo
    • Bulletin of the Korean Mathematical Society
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    • v.56 no.4
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    • pp.993-1006
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    • 2019
  • This article concerns a ring property which preserves the reversibility of elements at nonzero idempotents. A ring R shall be said to be quasi-reversible if $0{\neq}ab{\in}I(R)$ for a, $b{\in}R$ implies $ba{\in}I(R)$, where I(R) is the set of all idempotents in R. We investigate the quasi-reversibility of 2 by 2 full and upper triangular matrix rings over various kinds of reversible rings, concluding that the quasi-reversibility is a proper generalization of the reversibility. It is shown that the quasi-reversibility does not pass to polynomial rings. The structure of Abelian rings is also observed in relation with reversibility and quasi-reversibility.

Modulation of chromatic reversibility of polydiacetylene Langmuir Schafer (LS) films by cadmium ion Ad/desorption

  • Lee, Gil Sun;Kim, Tae Young;Ahn, Dong June
    • Journal of Industrial and Engineering Chemistry
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    • v.67
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    • pp.312-315
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    • 2018
  • Although the reversibility of 10,12-pentacosadiynoic amino meta-acid(PCDA-mBzA) against temperature and pH was reported, the modulation of reversibility by ion adsorption at terminal functional group has not been investigated. In this work, we developed a simple method for modulating the reversibility of PCDA-mBzA films upon a thermal stimulus by cadmium ion adsorption inducing the breakage of the outer hydrogen bonding of two hydrogen bonds, which are responsible for the reversible properties of PCDA-mBzA. External reflection-Fourier transform infrared (ER-FTIR) analyses revealed that the hydrogen bonding between the carboxylic acid groups was broken through ion adsorption and only a single hydrogen bond between the amide groups remained in the PCDA-mBzA polymer. In addition, PCDA-mBzA films could recover their original property through cadmium ion desorption. These results present that the transition between reversibility and irreversibility can be modulated artificially simply through the adsorption and desorption of metal ions.

A Note on the Reversibility of the Two Stage Assembly Scheduling Problem

  • Yoon, Sang-Hum;Lee, Ik-Sun;Sung, Chang-Sup
    • Management Science and Financial Engineering
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    • v.13 no.1
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    • pp.25-34
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    • 2007
  • This paper is concerned with proving a conjecture that the two stage assembly system is reversible in deterministic makespan scheduling context. The reversibility means that a job sequence in the assembly system has the same makespan as that of its reverse sequence in the disassembly system which is the reversal of the assembly system. The proposed conjecture shows that the reversibility of serial flowshops can be extended to non-serial and synchronized shops.

Quantitative estimation of reversibility of the discharge process undergone by nickel hydroxide film cathodically deposited on pure nickel as a positive supercapacitor electrode using cyclic voltammetry and potential drop method

  • Pyun Su-Il;Moon Sung-Mo
    • Journal of the Korean Electrochemical Society
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    • v.1 no.1
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    • pp.8-13
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    • 1998
  • This work presents the way how to evaluate the degree of reversibility of the discharging process undergone by the nickel hydroxide film cathodically deposited on pure nickel as a positive electrode for electrochemical capacitor using the combined cyclic voltammetry and potential drop method, supplemented by galvanostatic discharge and open-circuit potential transient methods. The time interval necessary just to establish the current reversal of anodic to cathodic direction from the moment just after applying the potential inversion of anodic to cathodic direction, was obtained on cyclic voltammogram. The cathodic charge density passed upon dropping the applied potential, was calculated on potentiostatic current density-time curve. Both the time interval and the cathodic charge density in magnitude can be regarded as being measures of the degree of reversibility of the discharging process undergone by the positive active material for supercapacitor, i.e. , the longer the time interval is, the lower is the degree of reversibility and the greater the cathodic charge density is, the higher is the degree of reversibility. From the applied potential dependences of the time interval and cathodic charge density, discharge at $0.42 V_{SCE}$ was determined to be the most reversible.

Supervisory Controller Design to Enforce Reversibility and Liveness in Colored Petri Nets

  • Aybar, Aydin;Cimen, Mustafa
    • International Journal of Control, Automation, and Systems
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    • v.5 no.4
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    • pp.463-470
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    • 2007
  • Colored Petri net model which is a model of discrete event systems is considered in this work. A supervisory controller which enforces reversibility and liveness simultaneously is presented. Furthermore, the algorithms, written by pseudo-code, are presented for the supervisory controller design. A program is developed to implement these algorithms.

Empirical modelling of chemically enhanced backwash during ultrafiltration process

  • Daramola, M.O.;Adeogun, A.G.
    • Membrane Water Treatment
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    • v.2 no.4
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    • pp.225-237
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    • 2011
  • In this study, response of reversibility of membrane flux during chemically enhanced backwash (CEB) to changes in filtration time, filtration flux and coagulant concentration dosing during ultrafiltration (UF) process was investigated using a regression model. The model was developed via empirical modelling approach using response surface methodology. In developing the model, statistically designed UF experiments were conducted and the results compared with the model output. The results showed that the performance of CEB, evaluated in terms of the reversibility of the membrane flux, depends strongly on the changes in coagulant concentration dosage and the filtration flux. Also the response of the reversibility of membrane flux during CEB is independent of the filtration time. The variance ratio, VR << $F_{value}$ and $R^2$ = 0.98 obtained from the cross-validation experiments indicate perfect agreement of the model output with experimental results and also testify to the validity and suitability of the model to predict reversibility of the membrane flux during CEB in UF operation.

A Study on Regressiveness of the VAT Burden and Tax Equity (부가가치세 부담의 역진성과 과세형평성에 대한 연구)

  • Chae, Byung-Wan;Lee, Seong-Ju
    • Journal of Venture Innovation
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    • v.3 no.1
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    • pp.165-182
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    • 2020
  • This research shows solutions for relieving the reversibility of the VAT system, and the solutions will be reviewed with current issues about supporting welfare. The Followings provide practical implementing solutions for each issue. Since the VAT is taxed for all goods and services as a general consumption tax, it is efficient tax policy for resource allocation comparing to income tax. On the other hand, because of the reversibility of the tax burden is also treated as a non-effective tax system for fair taxation. Even it is a non-effective tax system, the VAT system takes the most portion from the total national tax. In South Korea economic system, it is hard to raise the VAT rate because the economic effects are tremendous. For the long-term, the possibility of increasing the VAT rate is unavoidable, considering the economy, society, environment and energy, and aging. Therefore, a variety of substituted policies for the reversibility should be covered once there is a conference for the increase in the VAT rate. This research provides foundational solutions by acknowledging the reversibility of the tax burden in terms of the effective value-added tax rate. The followings are four solutions. First, it is required to adjust the duty-free system for relieving the reversibility and expand the tax-free system as well as individual consumption tax items. Second, The relief of reversibility should be worked by imposing higher the tax rate for high-income people' goods and services. Third, the adjustment of the duty-free system could be considered due to relieve the reversibility of the VAT. Last, it is considered to adjust of the simplified taxation system because the simplified taxation system is seriously against the tax-transfer principles.

The Flesh Encountering with the Others (살과 타자의 만남)

  • Ryu, Eui-Geun
    • Journal of Korean Philosophical Society
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    • v.105
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    • pp.193-214
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    • 2008
  • This paper is about to analyse Merleau-Ponty's notion of flesh on textual evidences through the structure of perception and to apply this result to his theory of the others. In the first place, we study what he thinks of philosophical investigation and thus of the essence of philosophy. With this process, we find out that perception is more important than reflection in philosophical investigation. Differently from the objective or objectivistic viewpoint, the truth of perception is revealed to go beyond distinction between consciousness and object. This truth refers to reversibility which Merleau-Ponty thinks to be the ultimate truth. The reversibility of perception leads to chiasms which reveal and unreveal the beings. In the final analysis, the flesh as reversibility is the Being in the beings. When it comes to the problem of other minds, we are confirmed through the movement of flesh that self-presence is the presence to the differentiated world, namely the others.

On the Fuzzy Approach to Integrated Evaluation of Complex Systems (퍼지 평가의 통합특성에 관하여)

  • 이철영;임봉택
    • Journal of Korean Port Research
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    • v.13 no.1
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    • pp.79-86
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    • 1999
  • This paper deals with the evaluation problem of complex systems by introducing a fuzzy approach. The authors are functionally supposing a hierarchical structure model of a complex system and give light on the following problems. First for the purpose of clarifying the characteristics of measures the property and differences between two method such as linear and fuzzy viewpoint are discussed through two level-down evaluation process. Second the integrated evaluation process which keeps reversibility between hierarchical levels is discussed and obtained some necessary conditions for reversibility of fuzzy evaluation. From these results it is expected that the fuzzy approach overcomes partly the limitation of reductionism at the hierarchical evaluation of complex systems.

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