• Journal of the Korean Solar Energy Society
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• v.31 no.2
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• pp.16-21
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• 2011

Since the maximum power operating point(MPOP) of PCS alters with changing atmospheric conditions temperature conditions shadow conditions it is important to operate for PCS to keep maximum power point tracking(MPPT) continuously. This paper presents the results of modeling PV system by PSIM simulator and investigates the influence on the PV system from aspect of power quality i.e. voltage drop. This paper investigates four MPPT algorithms; Perturbation & Observation(P&O) Improved P&O Incremental Conductance(Incond) Differential coefficient method simulated with irradiation temperature change and shadow conditions.

• English & American cultural studies
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• v.14 no.2
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• pp.49-75
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• 2014

This paper argues that John Leguizamo disguises ethical intention with humor in his one-person show, Freak. The argument proceeds in three stages. First, on the basis of Slavoj ${\check{Z}}i{\check{z}}ek^{\prime}s$ theory that fantasies teach us how to desire discussed in The Sublime Object of Ideology, I analyze how and why Leguizamo exaggerates and thus de-constructs the ideological fantasies about Latin Americans in Freak. Through this analysis the ridiculous exaggeration of the fantasies and their deconstruction emerges as the means to surface the trauma caused by the fantasies, internally and externally curing and reconciling the audience. Second, I apply ${\check{Z}}i{\check{z}}ek^{\prime}s$ theory of the quilting point introduced in Looking Awry: An Introduction to Jacques Lacan through Popular Culture to reveal how "blots" in Freak form "black holes" in the audience's consciousness to smash their established view of the reality, inducing them to encounter with "the real." The investigation into Leguizamo's use of humor as the quilting point illuminates how he invites the audience to look awry beyond the popular fantasy at "the real" America. Third, on the ground of Emmanuel Levinas's theory that theaters are the space of ethics, namely "ethotopos" to emphasize responsible actions discussed in "Ethics as First Philosophy," I assert that Leguizamo disguises his ethical message with humor so as for the audience to recognize their responsibility for others in America and take action towards change.

• Korean Journal of Metals and Materials
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• v.48 no.4
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• pp.315-319
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• 2010

In this study, the hydrogen reduction behavior of ball-milled NiO nanopowder was investigated depending on the partial pressure of water vapor. The hydrogen reduction behavior was analyzed by thermogravimetry and hygrometry under heating to 873 K in hydrogen. In order to change the partial pressure of the water vapor, the dew point of hydrogen was controlled in the range of 248 K~293 K by passing high-purity hydrogen through a saturator that contained water. Interestingly, with the increase in the dew point of the hydrogen atmosphere, the first step of the hydrogen reduction process decreased and the second step gradually increased. After the first step, a pore volume analysis revealed that the pore size distribution in the condition with a higher water vapor pressure shifted to a larger size, whereas the opposite appearedat a lower pressure. Thus, it was found that the decrease in the pore volume during the chemical reaction controlled process at a dew point of 248 K caused a reduction in retardation in the diffusion controlled process.

• Journal of Digital Convergence
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• v.14 no.8
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• pp.105-113
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• 2016

This study analyzed and verified panel data based on CSMAR (China Stock Market & Accounting Research) DB from 2002 to 2014 in order to find out significant differences of conservative accounting before and after Chinese companies adopted international accounting standards. Financial changes in companies can occur at the point of change in accounting standards, and as the difference would affect conservative accounting, it is important to understand conservatism in financial transaction. In this study, earnings per share and price, return on equity, and debt ratio were measured. As a result of analysis, conservative accounting has increased after the introduction of accounting standards, and as the debt ratio was higher, the proportion of conservative accounting was higher. Thus, at a certain point of change in accounting standards, companies apply conservative accounting in order to improve reliability in an unstable future financial environment. Therefore, this study is expected not only to practically influence business practice in changes in GAAP rules but also to provide useful guidance for future studies.

• Asia-Pacific Journal of Business
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• v.14 no.1
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• pp.265-279
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• 2023

Purpose - The purpose of this paper is to compare and review behavioral economics models that explain stock price changes after large-scale price shocks in the Korean stock market and to find a suitable model. In this paper, among the theories reviewed, it was confirmed that the anchoring heuristics theory has high explanatory power for stock prices after large-scale stock price fluctuations. Design/methodology/approach - This paper conducts an event study on stock price shocks in which the individual stocks that make up the KOSPI200 index show more than 10% fluctuation on a daily basis. In order to materialize the abstract predictions of heuristics theories in a varifiable form, this paper uses the daily stock price index change as a reference point for availability heuristics, and uses the 52-week highest and lowest price as reference point for anchoring heuristics. Research implications or Originality - As a result of the empirical analysis, the stock price reversals did not consistently appear for changes in the daily index. On the other hand, the stock price drifts consistently appeared around the 52-week highest and the 52-week lowest price. And in the multiple regression analysis that controlled for company-specific and event-specific variables, the results that supported the anchoring heuristics were more evident. These results suggest that it is possible to establish an investment strategy using large-scale price change in Korean stock market.

• Ecology and Resilient Infrastructure
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• v.9 no.2
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• pp.83-92
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• 2022

The 2020 summer extreme flood severely disturbed the riparian ecosystem of the Seomjin River. Some trees were killed by the flood impact, whereas others have recovered through epicormic regeneration after the disturbance. At the same time, several tree individuals newly germinated. This research aimed to explain the recovery of the riparian ecosystem by spatial proximity between each tree individual of different characteristics, such as "dead", "recovered", and "newly germinated". A spatial point pattern analysis based on K and g-functions revealed that the newly germinated trees and the existing trees were distributed in the spatially clumping patterns. However, further detailed analysis revealed that the new trees were statistically less attracted to the recovered trees than the dead trees, implying competitive interactions hidden in the facilitative interactions. Habitat amelioration by the existing trees positively affected the growth of the new trees, while "living" existing trees were competing with the new trees for resources. This research is expected to provide new knowledge in this era of rapid climate change, which likely induces stronger and more frequent natural disturbance than before. Environmental factors have been widely used for ecosystem modeling, but species interactions, represented by the relative spatial distribution of plant individuals, are also valuable factors explaining ecosystem dynamics.

• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.35-40
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• 2023

In order to prevent an ammonia container from bursting under conditions such as overcharging and abnormal temperature rise, it is necessary to prepare accident prevention measures through analysis of the operating mechanism of the Thermally Activated Pressure Relief Devices (TPRD) attached to the container. In this study, stress analysis acting on the ammonia container under pressurized conditions, density change analysis according to temperature change, and correlation between container filling amount and temperature and pressure change were presented. In addition, the maximum filling amount of the ammonia container was calculated, and the temperature and pressure at the filling amount were calculated through the phase equilibrium diagram. Based on this, the appropriate melting point of the Thermally Activated Pressure Relief Devices was derived and verified through a melting temperature experiment. Based on the results of this study, conditions for preventing ammonia container rupture accidents were suggested.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3319-3325
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• 2013

In this paper, hand acupuncture used as a way of life medicine in everyday life, the influence of human organ will be investigated by applying IT techniques. For this, hand acupuncture is based on priority of the most important organ in the human body to target the cardiac associated with cardiac reflex point A16 acupuncture point before and after for 5 min to stimulation of facial images were collected and applied to the Lab color system associated with the cardiac, color value of cheonjung and lips region were measured for comparison and analysis. Finally, by measuring the change in bio-image signals A16 acupuncture point stimulation effects on cardiac function were performed to investigate the effectiveness of acupuncture. Also, statistical significance tests from the experimental results were performed whether the experimental results is valid or not.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.6
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• pp.699-705
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• 2011

High-maneuver missile is a projectile which demands a strong momentum at short time. To produce a necessary thrust for the flight, the gas of high temperature and pressure is generated through explosive combustion of solid propellant, and a great thrust can be obtained by expanding this high temperature and pressure gas. Although the operating time of a rocket motor is less than a few seconds, a failure of part or ablation near the throat of nozzle may take place during the expansion of high temperature and pressure gas for great thrust. In other words, for the precise control of a missile an exact stress analysis considering both, the thermal stress caused by the heat transfer between combustion gas and wall, and the mechanical stress caused by the pressure change in the flow, should be considered first. In this connection, this study investigated the safety, as a point of view of stress and melting point of the material, of the pre-designed thrust generating structure which is subjected to high temperature and pressure as a function of motor operating time.

• Journal of the Korean Geosynthetics Society
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• v.22 no.3
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• pp.97-103
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• 2023

Recently, research on the lateral resistance of pile foundations has been actively conducted. In experimental studies on the lateral resistance of pile foundations, displacement control or load control methods are used. However, in the case of the displacement control method, the lateral resistance of the pile varies depending on the rate of the load applied to the pile. Therefore, this study seeks to determine the change in lateral resistance of pile foundations according to lateral loading rate through model experiments. The experimental results showed that the lateral resistance of the pile tended to decrease as the lateral loading rate applied to the pile head increased. In order to confirm this, a model experiment of the side change of the ground and pile according to the loading rate was additionally conducted. Through inverse analysis, the change in the depth of the rotation point according to the lateral loading rate was identified. Through the change in the lateral resistance of the pile foundation and the depth of the rotating point according to the lateral loading rate, it was proposed to test the loading rate within 1.5 mm/min during the lateral loading test of the pile.