• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.111-111
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• 2014

Intensity interferometry, based on the Hanbury Brown--Twiss effect, is a simple and inexpensive method for optical interferometry at microarcsecond angular resolutions. Motivated by recent technical developments, we argue that the sensitivity of large modern intensity interferometers can be improved by factors up to approximately 25,000, corresponding to 11 photometric magnitudes, compared to the pioneering Narrabri Stellar Interferometer of the 1970s when resolving. Our approach, based on spectrally resolved light, permits the construction of large optical interferometers at the cost of (very) long-baseline radio interferometers. Realistic intensity interferometers are able to spatially resolve main-sequence O-type stars in the Magellanic Clouds. Multi-channel intensity interferometers can address a wide variety of science cases: (i) linear radii, effective temperatures, and luminosities of stars; (ii) mass-radius relationships of compact stellar remnants; (iii) stellar rotation; (iv) stellar convection and the interaction of stellar photospheres and magnetic fields; (v) the structure and evolution of multiple stars; (vi) direct measurements of interstellar distances; (vii) the physics of gas accretion onto supermassive black holes; and (viii) calibration of amplitude interferometers by providing a sample of calibrator stars.

• The Korean Journal of Pain
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• v.34 no.1
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• pp.94-105
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• 2021

Background: Many patients with complex regional pain syndrome (CRPS) have been known to be at risk of suicide, due to severe pain and its comorbid conditions. The risk of suicide may be associated with affective instability, which is an indicator of emotional dysregulation. Particularly, unstable shifts in negative emotions are difficult to cope with, which may result in individuals feeling uncontrollable, hopeless, and entrapped. This study aimed to examine the role of affective instability in the relationship between pain intensity and suicide risk (suicidal ideation and impulsivity) in patients with CRPS, by employing a daily diary. Methods: Twenty-three patients registered at the CRPS Association in Korea were asked to complete a day-to-day routine for 15 days, followed by a diary composed of pain intensity, suicidal ideation, impulsivity, and positive and negative affects. Results: Results showed that the interactions between negative affective instability and daily pain intensity were statistically significant on daily suicidal ideation (coefficient = 0.41, t (21) = 2.56, P < 0.050) and daily impulsiveness (coefficient = 1.20, t (19) = 3.35, P < 0.010). However, those between positive affective instability and daily pain intensity were not. Conclusions: This study is the first attempt to investigate the role of affective instability on the relationship between daily pain intensity and daily suicide risk in patients with CRPS. Our findings suggest that health professionals pay considerable attention to the instability of negative affects when assessing and managing patients with CRPS at risk of suicide.

• Earthquakes and Structures
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• v.21 no.6
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• pp.601-612
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• 2021

The paper concerns the selection of a design accelerograms used for the slope stability assessment under earthquake excitation. The aim is to experimentally verify the Arias Intensity as an indicator of the excitation threat to the slope stability. A simple dynamic system consisting of a rigid block on a rigid inclined plane subjected to horizontal excitation is adopted as a slope model. Strong ground motions recorded during earthquakes are reproduced on a shaking table. The permanent displacement of the block serves as a slope stability indicator. Original research stand allows us to analyse not only the relative displacement but also the acceleration time history of the block. The experiments demonstrate that the Arias Intensity of the accelerogram is a good indicator of excitation threat to the stability of the slope. The numerical analyses conducted using the experimentally verified extended Newmark's method indicate that both the Arias Intensity and the peak velocity of the excitation are good indicators of the impact of dynamic excitation on the dam's stability. The selection can be refined using complementary information, which is the dominant frequency and duration of the strong motion phase of the excitation, respectively.

• Asia-Pacific Journal of Business
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• v.12 no.3
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• pp.397-415
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• 2021

Purpose - The purpose of this study is to analyze the cost behavior of firms, taking into account both high R&D intensity and situations in which R&D activities are likely to be performed efficiently. Design/methodology/approach - During the sample period from 2002 to 2019, regression analysis is conducted on the manufacturing firms with December fiscal year listed on KOSDAQ. The degree of R&D expenditure was measured by R&D intensity. The efficient R&D situation is measured as the decline stage firms in the KOSDAQ market, which are relatively smaller than the KOSPI market. Findings - Firms in the decline phase and high R&D intensity showed the cost stickiness. Because these firms anticipate an optimistic future, they do little to cut current costs even if their current sales decrease. Research implications or Originality - Firstly, it is confirmed that both the extent of R&D expenditure and the situation in which R&D will be effectively performed are important in the study of cost behavior. Secondly, we present a new perspective on strategy research that favors the use of cost advantage strategy related to cost anti-stickiness for the decline firms.

• Asia-Pacific Journal of Business
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• v.14 no.1
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• pp.59-71
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• 2023

Purpose - The purpose of this study is to investigate the effect of corporate social responsibility (CSR) on firm performance in China, plus the moderating effects of advertising intensity and environmental pollution. Design/methodology/approach - We analyzed our dataset that consists of 188 public Chinese firms drawn from the Shanghai and Shenzhen exchanges during 2010-2020. Findings - Based on the stakeholder theory and signaling theory, we proposed the positive relationship between the CSR level and the firm performance. Further, we configured consumers and the government as major stakeholders in China, suggesting positive moderating effects of advertising intensity and environmental pollution, respectively. Research implications or originality - The results show that the CSR level increases the firm performance. The advertising intensity positively moderates the relationship between the CSR level and the firm performance, but there was no significant moderating effects of environmental pollution. The findings confirm the importance of consumers for the CSR stakeholders. While the Chinese government strongly reinforces environmental regulation, CSR itself does not seem to be the fine-aligned action prioritized for mitigating environmental pollution.

• Physical Therapy Rehabilitation Science
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• v.12 no.3
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• pp.293-299
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• 2023

Objective: This study aimed to investigate the potential benefits of microcurrent stimulation as a non-invasive therapeutic approach for managing pain and improving the quality of life in women suffering from primary dysmenorrhea. Design: A case study. Methods: This study was conducted, involving a cohort of 6 women diagnosed with primary dysmenorrhea, aged between 20 to 30 years. Participants were received microcurrent stimulation using low-intensity microcurrents for 30 minutes every day for 4 weeks. The intensity of microcurrent stimulation was 25 μA and the frequency was 8 Hz. The intervention was administered between the menstruations, with pain intensity and quality of life being assessed at baseline, and then at the end of menstrual cycle. Pain intensity was evaluated using a visual analog scale (VAS) and menstrual symptom questionnaire (MSQ), while the quality of life was assessed through the stress response inventory (SRI), state trait anxiety inventory (STAI), center for epidemiologic studies depression (CES-D), and menstrual distress questionnaire (MEDI-Q). Results: After the intervention, participants demonstrated a statistically significant reduction in pain intensity, as evidenced by improved VAS scores (p<0.05). However, the changes in MSQ scores did not reach statistical significance. Regarding quality of life measures, no statistically significant differences were found in the SRI, STAI, CES-D, and MEDI-Q scores after the intervention (p>0.05). Conclusions: This study suggest that microcurrent stimulation holds promise as a potential treatment option for alleviating pain associated with primary dysmenorrhea.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.1
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• pp.32-40
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• 2010

In this work, the method of acquiring the pupil function of optical system is proposed. The wavefront aberration and the intensity distribution of pupil can be analysed with the pupil function. This system can be adopted to the manufacturing line of optical pickup directly and also has good performance to analysing various property of optical instrument. It is one kind of inverse problem to get pupil functions by 3D beam data. The extended Nijboer-Zernike(ENZ) approach recently proposed by Netherlands research group is adopted to accompany to solve these inverse problem. The ENZ approach is one of a aberration retrieval method for which numerous approaches are available. But this approach is new in the sense that it use the highly efficient representation of pupil functions by means of their Zernike coefficients. These coefficients are estimated by using matching procedure in the focal region the theoretical 3D intensity distribution and measured 3D intensity distribution. The algorithm that can be applied more general circumstance such as high-numerical aperture instrument is developed by modifying original ENZ approach. By these scheme, MS windows based GUI program is developed and the good performance is verified with generated 3D beam data.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.170-170
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• 2023

Providing safe and readily available water is vital to maintain public health. One of the most prevalent methods to prevent the spread of waterborne diseases is applying chlorine injection to the treated water before distribution. During the water transmission and distribution, the chlorine will experience a reduction, which can imply potential risks for human health if it falls below the minimum threshold. The ability to determine the appropriate initial intensity of chlorine at the source would be significant to prevent such problems. This study proposes two methods that integrate hydraulic and water quality modeling to determine the suitable intensity of chlorine to be injected into the source water to maintain the minimum chlorine concentration (e.g., 0.2 mg/l) at each demand node. The water quality modeling employs the first-order decay to estimate the rate of chlorine reduction in the water. The first method utilizes a backtracking algorithm to trace the path of water from the demand node to the source during each time step, which helps to accurately determine the travel time through each pipe and node and facilitate the computation of time-dependent chlorine decay in the water delivery process. However, as a backtracking algorithm is computationally intensive, this study also explores an alternative approach using a water age. This approach estimates the elapsed time of water delivery from the source to the demand node and calculate the time-dependent reduction of chlorine in the water. Finally, this study compares the outcomes of two approaches and determines the suitable and effective method for calculating the chlorine intensity at the source to maintain the minimum chlorine level at demand nodes.

• International Journal of Computer Science & Network Security
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• v.21 no.5
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• pp.129-132
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• 2021

Two feature selection approaches are analyzed in this study. First Approach used in this paper is Filter Approach which comprises of correlation technique. It provides two reduced feature sets using positive and negative correlation. Secondly Approach used in this paper is the wrapper approach which comprises of Sequential Forward Selection technique. The reduced feature set obtained by positive correlation results comprises of Rate of Acceleration, Intensity and Formant. The reduced feature set obtained by positive correlation results comprises of Rasta PLP, Log energy, Log power and Zero Crossing Rate. Pitch, Rate of Acceleration, Log Power, MFCC, LPCC is the reduced feature set yield as a result of Sequential Forwarding Selection.

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.5
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• pp.412-423
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• 2000

By using the relation between stress intensity factor and AE parameter, new approach method for assessing the crack length and detectability of crack was proposed. Laboratory experiment was carried out to identify AE characteristics of fatigue cracks for compact tension specimen. The relationship between a stress intensity factor and AE signals activity as well as conventional AE parameter analysis was discussed. As a result, the features of specific parameter such as the length of crack growth the AE energy, the AE peak amplitude, and the cumulative AE hits, showed the almost same trend in their increase as the number of fatigue cycle increased. From the comparisons of peak amplitude and AE energy with stress intensity factor, it was verified that the higher stress intensity factors generated AE signals with higher peak amplitude and a larger number of AE counts. If we can get more reliable database for the relation between AE parameters and stress intensity factor, this approach will provide a good information for evaluating both the existence of crack and the minimum detectable size of crack.