• Title/Summary/Keyword: Heterogeneous conditions

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Remarks on Defining Korean NPIs in terms of Negation Strength

  • Shin, Keun-Young;Chung, Dae-Ho
    • Language and Information
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    • v.13 no.2
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    • pp.47-57
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    • 2009
  • It has been observed that not all negative polarity items (NPIs) are licensed in the same negative contexts, and different NPIs may be licensed by different negative expressions. This shows that Ladusaw's (1979) downward entailment is not precise enough to account for the distributional patterns of NPIs (van der Wouden, 1997; van der Wouden and Zwarts, 1993; Zwarts, 1986, among others). One well-known attempt to deal with this issue is to divide negative expressions into several subtypes. Using boolean semantics, Zwarts (1986; 1998) distinguishes three kinds of downward entailing licensors and accounts for heterogeneous NPI-licensing conditions by means of the semantic strength of negative expressions. This approach has been adopted to define Korean negation (Nam, 1994; Chung, 1993; Chung, 1997; Hwang, 2009). In this paper, however, we argue that the boolean semantic approach for negation is not adequate in characterizing the properties of Korean negative expressions and explaining the contexts of licensing Korean NPIs.

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Selective Oxidation of Cyclohexane at Low Temperature by Fe-Pd Bicatalytic Systems: $FeCl_2$-Pd/alumina System and Pd/$Fe_2O_3$ System

  • 전기원;Lingaiah Nakka;김상범;이규완
    • Bulletin of the Korean Chemical Society
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    • v.18 no.12
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    • pp.1269-1273
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    • 1997
  • The system which employs iron, palladium, molecular oxygen and hydrogen as a model mono-oxygenase, has been investigated to develop a new method for selective cyclohexane oxidation uner mild conditions. This system provides much higher yield and selectivity for the formation of cyclohexanol and cyclohexanone compared to that of the existing industrial method. When the catalytic system, FeCl2-Pd/alumina, was employed, the oxidation system required acetone as a solvent to be efficient and acidifying the solvent by a little addition of acetic acid or HCl made the system more efficient. The Pd catalyst was recyclable without a significant deactivation but the recycling of ferrous chloride showed the decrease in the activity. On the other hand, the heterogeneous catalytic system, Pd/Fe2O3 could be recovered easily and reused after drying treatment.

A Generalized Model for Homogenized Reflectors

  • Pogosbekyan, Leonid;Kim, Yeong-Il;Kim, Young-Jin;Joo, Hyung-Kook
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05a
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    • pp.40-45
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    • 1996
  • A new concept of equivalent homogenization is proposed. The concept employs new set of homogenized parameters: homogenized cross sections (XS) and interface matrix (IM), which relates partial currents at the celt interfaces. The idea of interface matrix generalizes the idea of discontinuity factors (DFs), proposed and developed by K.Koebke and K.Smith. The method of K.Smith can be simulated within framework of new method, while the new method approximates heterogeneous cell better in case of the steep flux gradients at the cell interfaces. The attractive shapes of new concept are: improved accuracy, simplicity of incorporation in the existing codes, equal numerical expenses in comparison to the K.Smith's approach. The new concept is useful for: (a) explicit reflector/baffle simulation; (b) control blades simulation; (c) mixed UO2/MOX core simulation, The offered model has been incorporated in the finite difference code and in the nodal code PANBOX. The numerical results show good accuracy of core calculations and insensitivity of homogenized parameters with respect to in- core conditions.

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TRANSIENT CHF PHENOMENA DUE TO EXPONENTIALLY INCREASING HEAT INPUTS

  • Park, Jong-Doc;Fukuda, Katsuya;Liu, Qiusheng
    • Nuclear Engineering and Technology
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    • v.41 no.9
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    • pp.1205-1214
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    • 2009
  • The critical heat flux (CHF) levels that occurred due to exponential heat inputs for varying periods to a 1.0-mm diameter horizontal cylinder immersed in various liquids were measured to develop an extended database on the effect of high subcoolings for quasi-steady-state and transient maximum heat fluxes. Two main mechanisms of CHF were found. One mechanism is due to the time lag of the hydrodynamic instability (HI) which starts at steady-state CHF upon fully developed nucleate boiling, and the other mechanism is due to the explosive process of heterogeneous spontaneous nucleation (HSN) which occurs at a certain HSN superheat in originally flooded cavities on the cylinder surface. Steady-state CHFs were divided into three regions for lower, intermediate and higher subcooling at pressures resulting from HI, transition and HSN, respectively. HSN consistently occurred in the transient boiling CHF conditions that correspond to a short period. It was also found that the transient boiling CHFs gradually increased, then rapidly decreased and finally increased again as the period became shorter.

Polymer-Supported Crown Ethers(Ⅳ) Synthesis and Phase-transfer Catalytic Activity

  • Shim Jae Hu;Chung Kwang Bo;Masao Tomoi
    • Bulletin of the Korean Chemical Society
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    • v.13 no.3
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    • pp.274-279
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    • 1992
  • Immobilization method of lariat azacrown ethers, containing hydroxyl group in the side arm of crown ring, on the polymer matrix and the phase-transfer catalytic activity of thus obtained immobilized lariat azacrown ethers were studied. Polystyrene resins with crown ether structures and hydroxyl groups adjacent to the macrorings were prepared by the reaction of crosslinked polystyrene resins containing epoxy groups with monoaza-15-crown-5 or monoaza-18-crown-6. Microporous crosslinked polystyrene resins containing epoxy group for the syntheses of these immobilized lariat crown catalysts were prepared by suspension polymerization of styrene, divinylbenzene (DVB 2%) and vinylbenzylglycidyl ether. The immobilized lariat catalysts with 10-20% ring substitution exhibited maximal activity for the halogen exchange reactions of 1-bromooctane with aqueous KI or NaI under triphase heterogeneous conditions. Immobilized catalyst exhibited higher activity than corresponding catalyst without the hydroxyl group and this result was suggested that the active site have a structure in which the $K^+$ ion was bound by the cooperative coordination of the crown ring donors and the hydroxyl group in the side arm.

The Resourcefulness of Sponsored Contents on Social Media -A Netnographic Approach to Customer Inspiration Cues-

  • Hyunjeong, Rhee;Kyu-Hye, Lee
    • Journal of Fashion Business
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    • v.26 no.6
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    • pp.116-132
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    • 2022
  • Fashion marketing activity performed by social media influencers (SMIs) has grown exponentially in the past years. Research regarding their marketing power is often discussed in the context of sponsorship disclosure, in order to overcome obstacles of impending regulations that may endanger the authenticity SMIs are perceived to have compared to traditional marketing agents. Upon recent heterogeneous findings, a netnographic approach was taken to examine the actual sponsored posts of SMIs on Instagram. Based on two representative cases that received media coverage, a qualitative analysis of 1,058 comments on Instagram showed customer inspiration and informational social influence regardless of sponsorship disclosures present. Regarding customer inspiration, high frequency of comments including choice imitation intentions was observed. Under certain conditions, customer responses were focused on the SMI's expertise irrespective from the brand being endorsed. Findings show future implications from both an academic and industry-focused perspective for future potential of SMIs in fashion marketing.

Ontology-based Facility Maintenance Information Integration Model using IFC-based BIM data

  • Kim, Karam;Yu, Jungho
    • International conference on construction engineering and project management
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    • 2015.10a
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    • pp.280-283
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    • 2015
  • Many construction projects have used the building information modeling (BIM) extensively considering data interoperability throughout the projects' lifecycles. However, the current approach, which is to collect the data required to support facility maintenance system (FMS) has a significant shortcoming in that there are various individual pieces of information to represent the performance of the facility and the condition of each of the elements of the facility. Since a heterogeneous external database could be used to manage a construction project, all of the conditions related to the building cannot be included in an integrated BIM-based building model for data exchange. In this paper, we proposed an ontology-based facility maintenance information model to integrate multiple, related pieces of information on the construction project using industry foundation classesbased (IFC-based) BIM data. The proposed process will enable the engineers who are responsible for facility management to use a BIM-based model directly in the FMS-based work process without having to do additional data input. The proposed process can help ensure that the management of FMS information is more accurate and reliable.

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Precision Cardiology: Phenotype-targeted Therapies for HFmrEF and HFpEF

  • Giuseppe M.C. Rosano;Cristiana Vitale;Ilaria Spoletini
    • International Journal of Heart Failure
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    • v.6 no.2
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    • pp.47-55
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    • 2024
  • Heart failure with mid-range ejection fraction (HFmrEF) and preserved ejection fraction (HFpEF) represent over half of heart failure cases but lack proven effective therapies beyond sodium-glucose cotransporter 2 inhibitor and diuretics. HFmrEF and HFpEF are heterogeneous conditions requiring precision phenotyping to enable tailored therapies. This review covers concepts on precision medicine approaches for HFmrEF and HFpEF. Areas discussed include HFmrEF mechanisms, anti-inflammatory and antifibrotic treatments for obesity-related HFpEF, If inhibition for HFpEF with atrial fibrillation, and mineralocorticoid receptor antagonism for chronic kidney disease-HFpEF. Incorporating precision phenotyping and matched interventions in HFmrEF and HFpEF trials will further advance therapy compared to blanket approaches.

PID-based Consensus and Formation Control of Second-order Multi-agent System with Heterogeneous State Information (이종 상태 정보를 고려한 이차 다개체 시스템의 PID 기반 일치 및 편대 제어)

  • Min-Jae Kang;Han-Ho Tack
    • Journal of the Institute of Convergence Signal Processing
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    • v.24 no.2
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    • pp.103-111
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    • 2023
  • Consensus, that aims to converge the states of agents to the same states through information exchanges between agents, has been widely studied to control the multi-agent systems. In real systems, the measurement variables of each agent may be different, the loss of information across communication may occur, and the different networks for each state may need to be constructed for safety. Moreover, the input saturation and the disturbances in the system may cause instability. Therefore, this paper studies the PID(Proportional-Integral-Derivative)-based consensus control to achieve the swarm behavior of the multi-agent systems considering the heterogeneous state information, the input saturations, and the disturbances. Specifically, we consider the multiple follower agents and the single leader agent modeled by the second-order systems, and investigate the conditions to achieve the consensus based on the stability of the error system. It is confirmed that the proposed algorithm can achieve the consensus if only the connectivity of the position graph is guaranteed. Moreover, by extending the consensus algorithm, we study the formation control problem for the multi-agent systems. Finally, the validity of the proposed algorithm was verified through the simulations.

A Rational Ground Model and Analytical Methods for Numerical Analysis of Ground-Penetrating Radar (GPR) (GPR 수치해석을 위한 지반 모형의 합리적인 모델링 기법 및 분석법 제안)

  • Lee, Sang-Yun;Song, Ki-Il;Park, June-Ho;Ryu, Hee-Hwan;Kwon, Tae-Hyuk
    • Journal of the Korean Geotechnical Society
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    • v.40 no.4
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    • pp.49-60
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    • 2024
  • Ground-penetrating radar (GPR) enables rapid data acquisition over extensive areas, but interpreting the obtained data requires specialized knowledge. Numerous studies have utilized numerical analysis methods to examine GPR signal characteristics under various conditions. To develop more realistic numerical models, the heterogeneous nature of the ground, which causes clutter, must be considered. Clutter refers to signals reflected by objects other than the target. The Peplinski material model and fractal techniques can simulate these heterogeneous characteristics, yet there is a shortage of research on the necessary input parameters. Moreover, methods for quantitatively evaluating the similarity between field and analytical data are not well established. In this study, we calculated the autocorrelation coefficient of field data and determined the correlation length using the autocorrelation function. The correlation length represented the temporal or spatial distance over which data exhibited similarity. By comparing the correlation length of field data with that of the numerical model incorporating fractal weights, we quantitatively evaluated a numerical model for heterogeneous ground. Consequently, the results of this study demonstrated a numerical modeling technique that reflected the clutter characteristics of the field through correlation length.