• Title/Summary/Keyword: global paradox

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Sorites Paradox and Supervaluationism (더미의 역설과 초평가주의)

  • Lee, Jinhee
    • Korean Journal of Logic
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    • v.16 no.2
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    • pp.189-231
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    • 2013
  • The purpose of this paper is to show that Williamson's counterexamples and Fara's paradox do not conclusively refute supervaluationism. I will achieve this purpose on the basis of local validity. In general, people regard supervaluational validity as global validity. And D-introduction, which is premise of Williamson's counterexamples and Fara's paradox, is justified only if we assume global validity. But it cannot correctly grasp supervaluational semantics, especially semantic character of D-operator. So I will show that validity of supervaluationism is local and define global validity by local validity. Strategy of this paper is to protect supervaluationism against Williamson's counterexamples and Fara's paradox by minimal modification of supervaluationism and to prove that supervaluational logic is not revisionary and weak for solving the sorites paradox.

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Comparison of functional Images obtained by radionuclide angiocardiography and gated blood pool scan (방사성핵종 심혈관조영술의 기능적영상화에 대한 고찰)

  • Bom, Hee-Seung;Kim, Ji-Yeul
    • The Korean Journal of Nuclear Medicine
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    • v.25 no.2
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    • pp.186-191
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    • 1991
  • Radionuclide cardiac studies lend themselves exceptionally well to functional imaging. This is especially true for gated blood pool scan (GBP). Making functional images is also possible in radionuclide angiocardiography (RNAC). In this study we tried to validate the functional images obtained from RNAC by comparing it with GBP. Twenty three patients (16 patients with coronary artery diseases, 5 with hypertensive heart diseases, and 2 with nonspecific chest pains) underwent simultaneous RNAC and GBP at the same position (LAO $45^{\circ}$). From both studies, global ejection fraction, regional ejection fraction, phase image, amplitude image, stroke image, paradox image, maximum ejection and maximum filling rates were obtained. Global ejection fraction are almost same in both studies. Regional ejection fractions of apex and inferior portion of left ventricle calculated from RNAC are well correlated with those of GBP. Phase and paradox image, maximum ejection and maximum filling rates were obtained. Global ejection fraction are almost same in both studies. Regional ejection fractions of apex and inferior portion of left ventricle calculated from RNAC are well correlated with those of GBP. Phase and paradox images of RNAC are very similar to those of GBP. However, amplitude and stroke images are different. Regional ejection fractions of the left ventricular base, maximum ejection and maximum filling rates obtained from RNAC are significantly different from those of GBP. In conclusion, albeit all of functional images of RNAC is not same as GBP, regional walt motions and global left ventricular function are expected to be successfully analyzed by phase and paradox image and ejection fraction.

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Seasonal changes in pan evaporation observed in South Korea and their relationships with reference evapotranspiration

  • Woo, Yin San;Paik, Kyungrock
    • Proceedings of the Korea Water Resources Association Conference
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    • 2017.05a
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    • pp.183-183
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    • 2017
  • Pan evaporation (Epan) is an important indicator of water and energy balance. Despite global warming, decreasing annual Epan has been reported across different continents over last decades, which is claimed as pan evaporation paradox. However, such trend is not necessarily found in seasonal data because the level of contributions on Epan vary among meteorological components. This study investigates long-term trend in seasonal pan evaporation from 1908 to 2016 across South Korea. Meteorological variables including air temperature (Tair), wind speed (U), vapor pressure deficit (VPD), and solar radiation (Rs) are selected to quantify the effects of individual contributing factor to Epan. We found overall decreasing trend in Epan, which agrees with earlier studies. However, mixed tendencies between seasons due to variation of dominant factor contributing Epan were found. We also evaluated the reference evapotranspiration based on Penman-Monteith method and compared this with Epan to better understand the physics behind the evaporation paradox.

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Asymmetric Interdependence and the Selective Diversification of Supply Chains

  • Nagy, Stephen R.;Nguyen, Hanh
    • Journal of Contemporary Eastern Asia
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    • v.20 no.2
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    • pp.237-258
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    • 2021
  • The COVID-19 pandemic has highlighted the risks of an over-concentration of supply chains in one country. It has motivated stakeholders to pursue diversification strategies. However, a paradox exists. Stakeholders have shied away from a complete decoupling and preferring to selectively enhance economic ties with China. This article explores this paradox by examining supply chain concentration in China as a form of asymmetric interdependence and the countermeasures from the U.S., Japan, Australia, and India to minimize vulnerabilities. It argues that while the COVID-19 disruptions have brought to light the risk of supply chain overconcentration in China, countermeasures are also driven by coercive diplomacy and the deepening U.S.-China rivalry. The paper also examines the feasibility of diversification efforts by focusing on the capacity and capabilities of alternative supply chain hubs. It finds that while states are actively seeking ways to prevent China from using asymmetric interdependence of supply chains and trade to gain political leverage, there are structural limits to the degree of diversification in the short to mid-term.

Plasticity of Amorphous Alloys: 2. Inhomogeneous Deformation (비정질 합금의 소성 2: 불균일변형)

  • Park, Kyoung-Won;Lee, Chang-Myeon;Lee, Jae-Chul
    • Korean Journal of Metals and Materials
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    • v.47 no.11
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    • pp.773-785
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    • 2009
  • Studies of a number of Cu-Zr amorphous alloys have demonstrated that those exhibiting greater plastic strain during homogeneous deformation at room temperature show lower global plasticity associated with inhomogeneous deformation in a typical compression test. Using a combination of experiments and molecular dynamics simulations, we clarify this seeming paradox between the homogeneous and inhomogeneous deformation by exploring the microstructural aspects in view of the structural disordering, disorder-induced softening, and shear localization and relate these findings to the global plasticity of bulk amorphous alloys. Additional analyses were conducted to derive a simple structural parameter that allows the prediction of the global plasticity of bulk amorphous alloys.

Testing an Irrational Model of Information Privacy Based on Competence Needs Satisfaction

  • Kim, Gimun;Yoon, Jongsoo
    • Journal of the Korea Society of Computer and Information
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    • v.23 no.12
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    • pp.241-248
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    • 2018
  • Recently, there have been calls for approaching from the irrationality point of view to better explain the privacy paradox phenomenon. This study is a kind of response to them. The aim of the study is to investigate how satisfying competence needs, one of basic psychological needs suggested in self-determination theory, affects irrational information disclosure decision (i.e., risk-benefit assessment). To do this, the study builds an irrationality-based model in which competence needs satisfaction affects both perceived risks negatively and perceived benefits (i.e., relationship building and maintenance), which in turn determine a level of self-disclosure. Based on the data from Facebook users which is collected by a large sample survey (N=1050), the study analyzes it using Mplus, a powerful structure equation modeling tool. The study results reveal that while the relationship between competence needs satisfaction and perceived relationship building and maintenance is statistically significant, the relationship between competence needs satisfaction and perceived risks insignificant. These findings imply that people who is in a high level of competence needs satisfaction is more likely to respond to some opportunities for social benefits and in turn disclose more information about self.

Changing climate in our lifetime: A review (우리 시대의 기후 변화를 돌아보다)

  • Paik, Kyungrock;Woo, Yin San
    • Journal of Korea Water Resources Association
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    • v.51 no.spc
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    • pp.1045-1056
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    • 2018
  • During the last decades, considerable efforts have been spent for climate studies, in particular to better understand changing climate. In turn, several significant trends in climatic variables have been reported. Explaining such trends is challenging - some of them have been considered contradictory to another. Various hypotheses have also been suggested for general description of changing climate. At this point in time, it would be beneficial to look back and carefully recollect our knowledge about climate change. In this paper, we aim to provide a comprehensive review on our forefront knowledge in this context with focus on the trends in temperature, solar radiation, wind speed, evaporation, and precipitation. Major trends, namely warming, dimming, and stilling, are demonstrated together with evaporation paradox and increasing precipitation variability, using data at Seoul. On the basis of understanding these notions, we suggest four key implications to hydrologists and engineers.

Characteristics of Signal-to-Noise Paradox and Limits of Potential Predictive Skill in the KMA's Climate Prediction System (GloSea) through Ensemble Expansion (기상청 기후예측시스템(GloSea)의 앙상블 확대를 통해 살펴본 신호대잡음의 역설적 특징(Signal-to-Noise Paradox)과 예측 스킬의 한계)

  • Yu-Kyung Hyun;Yeon-Hee Park;Johan Lee;Hee-Sook Ji;Kyung-On Boo
    • Atmosphere
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    • v.34 no.1
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    • pp.55-67
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    • 2024
  • This paper aims to provide a detailed introduction to the concept of the Ratio of Predictable Component (RPC) and the Signal-to-Noise Paradox. Then, we derive insights from them by exploring the paradoxical features by conducting a seasonal and regional analysis through ensemble expansion in KMA's climate prediction system (GloSea). We also provide an explanation of the ensemble generation method, with a specific focus on stochastic physics. Through this study, we can provide the predictability limits of our forecasting system, and find way to enhance it. On a global scale, RPC reaches a value of 1 when the ensemble is expanded to a maximum of 56 members, underlining the significance of ensemble expansion in the climate prediction system. The feature indicating RPC paradoxically exceeding 1 becomes particularly evident in the winter North Atlantic and the summer North Pacific. In the Siberian Continent, predictability is notably low, persisting even as the ensemble size increases. This region, characterized by a low RPC, is considered challenging for making reliable predictions, highlighting the need for further improvement in the model and initialization processes related to land processes. In contrast, the tropical ocean demonstrates robust predictability while maintaining an RPC of 1. Through this study, we have brought to attention the limitations of potential predictability within the climate prediction system, emphasizing the necessity of leveraging predictable signals with high RPC values. We also underscore the importance of continuous efforts aimed at improving models and initializations to overcome these limitations.

Exploring Perceptions of 'Foreignness' in Virtual Teams: Its Impact on Team Member Satisfaction and Turnover Intention

  • Garrison, Gary;Wakefield, Robin L.;Harvey, Michael;Kim, Sang-Hyun
    • Asia pacific journal of information systems
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    • v.20 no.1
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    • pp.101-125
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    • 2010
  • This paper uses the status inconsistency theory to identify factors related to team members' (dis)satisfaction with the composition of virtual IT project teams in order to predict their turnover intentions. Our approach is based on the premise that virtual teams, although increasingly popular among global organizations, create an environment replete with cultural and functional diversity. Yet, a paradox exists: increasing diversity in virtual teams maximizes the creation and use of organizational knowledge while simultaneously increasing dissatisfaction and turnover. This is a critical issue in the formation and management of virtual teams. Therefore, we investigate how team members' perceptions of differences among themselves (i.e. foreignness) impact the stability of team membership, leading to what we describe as a 'liability of foreignness.' Findings indicate that a member's perception of foreignness has a detrimental effect on satisfaction with his or her team members while satisfaction is likely to decrease turnover intention. This may be an implication that managers need to maintain a balance in order to discourage member turnover and the loss of key players.

An Electron Microscopic Study on the Effect of Calcium-free Reperfusion in Isolated Perfused Guinea Pig Heart after Global Ischemia (허혈후 칼슘 결핍 용액의 재관류가 적출 관류 기니픽 심근 세포에 미치는 영향에 관한 전자현미경적 관찰)

  • Oh, Seung-Hwan;Kim, Ho-Dirk;Rah, Bong-Jin
    • Applied Microscopy
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    • v.20 no.1
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    • pp.65-76
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    • 1990
  • The effect of calcium-free reperfusion for 5, 10, and 15 minutes, respectively, followed by continuous reperfusion with normal Tyrode solution containing 1.0mM calcium chloride, after global ischemia in the isolated perfused guinea pig heart by Langendorff techniques was examined with transmission electron microscope. Compared to the nomal Tyrode solution-perfused control hearts, the 5 minute calcium-free-reperfused hearts showed loss or thickening of Z lines, focal sarcolemmal disruption, mitochondrial swelling, clumping of chroma-tin, intracellular fluid accumulation, and some separation of cell junctions, especially the fasciae adherentes. These changes became more severe in the hearts of 10 minute calcium-free reperfusion. Subsarcolemmal larger bleb and near complete separation of cell junctions were noticed. In the 15 minute calcium-free-reperfused hearts, irreversible ultrastructural changes including contraction bands, biazrre mitochondria, and sarcolemmal destruction were widely distributed. The severity of myocardial changes were in accordance with the duration of calcium-free reperfusion. These changes indicate that calcium-free reperfusion regardless of its duration could not salvage the post-ischemic myocardium probably due to development of calcium paradox.

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