• Title/Summary/Keyword: critical wave

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Thomas Young's Problem Solving through Analogical Reasoning in the Process of Light Inference Theory Formation and Its Implications for Scientific Creativity Education (창의적 과학자 토마스 영(T. Young)의 빛의 간섭 이론 형성과정에서의 비유추론을 통한 문제해결과 과학창의성 교육적 함의)

  • Kim, Wonsook;Kim, Youngmin;Seo, Hae-Ae;Park, Jongseok
    • Journal of Gifted/Talented Education
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    • v.23 no.5
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    • pp.817-833
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    • 2013
  • The study aims to analyze Thomas Young's problem solving processes of analogical reasoning during the formation of the interference theory of light, and to draw its implications for secondary science education, particularly for enhancing creativity in science. The research method employed in the study was literature review of the papers which Young himself had written about sound wave and property of light. His thinking processes and specific features in his thought that were obtained through analysis of his papers about light are as follows: Young reconsidered Newton's experiments and observations, and reinterpreted Newton's results in the new viewpoints. Through this analysis, Young discovered that Newton's interpretation about his own experiments and observations was faulty in a certain point of view and new interpretation is necessary. Based on the data, it is hypothesized that colors observed on thin plates and colors appeared repeatedly on Newton's ring are appeared because of the effect of light interference. Young used analogical reasoning during the process of inference of similarity between sound and light. And he formulated an hypothesis on the interference of light through using abductive reasoning from interference of water wave, and proved the hypothesis by constructing an creative experimental device, which is called a critical experiment. It is implicated that the analogical reasoning and experimental devices for explaining the light interference which Young created and used can be utilized for school science education enhancing creativity in science.

Sterilization of Yakju(Rice Wine) Using a Batch-type High Voltage Pulsed Electric Field System (고전장펄스를 이용한 약주의 회분식 살균)

  • Kim, Su-Yeon;Park, Young-Seo;Mok, Chul-Kyoon
    • Korean Journal of Food Science and Technology
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    • v.31 no.5
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    • pp.1247-1253
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    • 1999
  • Yakju(rice wine) was sterilized with high-voltage pulses of short time on a batch pulsed electric field(PEF) system. The initial microbial counts of Yakju were 7.52 X $10^4\;CFU/mL$ for total aerobes, 2.20 X $10^4\;CFU/mL$ for lactic acid bacteria and 7.08 X $10^4\;CFU/mL$ for yeasts. The pH, acidity and electric conductivity of Yakju were 3.36, 0.462% and 1.24 mS/cm, respectively. Yakju was treated with 2-250 of pulses exponential-wave formed electric pulses under the field strength of 12.5-25 kV/cm. The critical strengths of the electrical field for the sterilization of Yakju were 7.5 kV/cm for total aerobes, 8.5 kV/cm for lactic acid bacteria and 6.5 kV/cm for yeasts. Logarithmic survival rates decreased linearly at low pulse number, but curvilinearly at high pulse number. The PEF sterilization kinetics of Yakju could be analysed by In s = In A-k In (n) and the sterilization rate constant increased with electric field strength and the size of target microorganisms. No changed in pH, acidity, and the growth of microorganisms were found in the PEF treated Yakju during the storage for 6 weeks at both $4^{\circ}C$ And $30^{\circ}C$.

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Evaluation of Adhesive Strength for Nano-Structured Thin Film by Scanning Acoustic Microscope (초음파 현미경을 이용한 나노 박막의 접합 강도 평가)

  • Park, Tae-Sung;Kwak, Dong-Ryul;Park, Ik-Keun;Miyasaka, Chiaki
    • Journal of the Korean Society for Nondestructive Testing
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    • v.32 no.4
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    • pp.393-400
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    • 2012
  • In recent years, nano-structured thin film systems are often applied in industries such as MEMS/NEMS device, optical coating, semiconductor or like this. Thin films are used for many and varied purpose to provide resistance to abrasion, erosion, corrosion, or high temperature oxidation and also to provide special magnetic or dielectric properties. Quite a number of articles to evaluate the characterization of thin film structure such as film density, film grain size, film elastic properties, and film/substrate interface condition were reported. Among them, the evaluation of film adhesive to substrate has been of great interest. In this study, we fabricated the polymeric thin film system with different adhesive conditions to evaluate the adhesive condition of the thin film. The nano-structured thin film system was fabricated by spin coating method. And then V(z) curve technique was applied to evaluate adhesive condition of the interface by measuring the surface acoustic wave(SAW) velocity by scanning acoustic microscope(SAM). Furthermore, a nano-scratch technique was applied to the systems to obtain correlations between the velocity of the SAW propagating within the system including the interface and the shear adhesive force. The results show a good correlation between the SAW velocities measured by acoustic spectroscope and the critical load measured by the nano-scratch test. Consequently, V(z) curve method showed potentials for characterizing the adhesive conditions at the interface by acoustic microscope.

Numerical analysis of pre-reinforced zones in tunnel considering the time-dependent grouting performance (터널 사전보강영역의 경시효과를 고려한 수치해석 기법에 관한 연구)

  • Song, Ki-Il;Kim, Joo-Won;Cho, Gye-Chun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.9 no.2
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    • pp.109-120
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    • 2007
  • Auxiliary support systems such as the reinforced protective umbrella method have been applied before tunnel excavation to increase ground stiffness and to prevent the large deformation. However, determination procedure of geotechnical parameters along the construction sequence contains various errors. This study suggests a method to characterize the time-dependent behavior of pre-reinforced zones around the tunnel using elastic waves. Experimental results show that shear strength as well as elastic wave velocities increase with the curing time. Shear strength and strength parameters can be uniquely correlated to elastic wave velocities. Obtained results from the laboratory tests are applied to numerical simulation of tunnel considering its construction sequences. Based on numerical analysis, initial installation part of pre-reinforcement and portal of tunnel are critical for tunnel stability. Result of the time-dependent condition is similar to the results of for $1{\sim}2$ days of the constant time conditions. Finally, suggested simple analysis method combining experimental and numerical procedure which considering time-dependent behavior of pre-reinforced zone on tunnel would provide reliable and reasonable design and analysis for tunnel.

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Effects of Flow Direction and Consolidation Pressure on Hydraulic Resistance Capacity of Soils (흐름방향과 압밀응력이 지반의 수리저항특성에 미치는 영향)

  • Kim, Youngsang;Jeong, Shinhyun;Lee, Changho
    • Journal of the Korean GEO-environmental Society
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    • v.16 no.5
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    • pp.55-66
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    • 2015
  • Big tidal differences, which range from 3.0 m to 8.0 m, exist with regional locations at south and west shores of Korea. Under this ocean circumstance, since a large scour may occur due to multi-directional tidal current and transverse stress of the wind, the scour surrounding the wind turbine structure can make instability of the system due to unexpected system vibration. The hydraulic resistance capacity of soils consolidated under different pressures are evaluated by Erosion Function Apparatus (EFA) under unidirectional and bi-directional flows in this study. It was found that the flow direction change affects significantly on the sour rate and critical shear stress, regardless of soil types while the consolidation pressure affects mainly cohesive soil. Among geotechnical parameters, the undrained shear strength can be well-correlated with the hydraulic resistance capacity, regardless soil type while the shear wave velocity shows the proportional relationships with the hydraulic resistance capacities of fine grained soil and coarse grained soil, respectively.

Trajectories of Drinking problems of the elderly: A Longitudinal Multi-level Growth Curve Model for Change (노인의 음주문제 발달궤적의 예측요인 : 다수준 성장곡선 모형의 적용)

  • Ahn, Jun Hee;Jang, Soo Mi
    • Korean Journal of Social Welfare Studies
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    • v.43 no.1
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    • pp.389-411
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    • 2012
  • A new era of research has focused on examining the growth of change in drinking problems among the elderly. Thus, the purpose of the present study was two fold: (1) to investigate trajectories of drinking problems(CAGE) among the Korean elderly(age$${\geq_-}65$$); and (2) to identify the predicting factors for the intercept and the slope of alcohol problems using multi-level growth curve model. Data come from three waves(1st wave(2006)~3rd wave(2008) of the Korea Welfare Panel(KWP) study. The results indicated that the levels of drinking problems decreased over time and that age, gender, marital status, religion, poverty, self-rated health, and social relationship satisfaction were associated with the baseline CAGE. Further analysis showed that social relationship satisfaction affected the declining slope of drinking problems over time. Specifically, among those who satisfied social relationship, there was a sharp decline of CAGE over time. Overall findings highlight the importance of developing and implementing effective alcohol prevention programs for the elderly in the community settings to mitigate the harmful effects of various psycho-social stressors. Especially, programs to maintain and form healthy social support network are suggested as critical interventions for prevention as well as recovery of alcohol problems in late life.

Center of Asia, The Role and Potential of K-Musical (아시아의 중심, K-Musical의 역할과 가능성)

  • Lee, Eun-Hye
    • Journal of Korea Entertainment Industry Association
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    • v.14 no.2
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    • pp.73-84
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    • 2020
  • South Korea's newly branded musical industry 'K-Musical' is currently booming. The growth of K-Musical can be attributed to the popularity of other industries in the Korean wave, namely K-Pop and Korean dramas. With the inclusion of K-Musicals into the Korean wave, it is beginning to standout on its own as a cultural brand. In the first half of 2012, the popularity of K-Musicals grew 24%, higher than any other performance industry. Moreover, this industry grew 20% in the latter half of 2012 and grew to 300 billion won in 2013. One reason for this growth can be attributed to the increased output of musicals of Korean origin in large-scale theatres dedicated solely to musicals. This has became to necessary foundation for the export of korean musicals abroad. Now is a critical time for Korean musicals to expand to other countries in order to become the hub of Asia for musical industries. 2012 and 2013 saw the greatest increase in the export of musicals to Japan and China. The musical sales in 2018 totaled 257.1 billion won, an increase of 29% over the previous year. Therefore, understanding the importance of these two markets is pivotal in the continued sustainable growth of K-Musicals. This paper seeks to highlights the importance of becoming the canter of Asia musicals and to offer strategies to lead Korea's musical industry toward this goal.

Double-Chambered Right Ventricle in an Old Standard Poodle Dog

  • Yunho Jeong;Yoonhwan Kim;Eunchan Lee;Ju-Hyun An;Sooyoung Choi;Jin-Young Chung;Jin-Ok Ahn
    • Journal of Veterinary Clinics
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    • v.40 no.2
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    • pp.130-134
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    • 2023
  • A 12-year-old Standard Poodle presented with intermittent weakness and occasional dyspnea at the Veterinary Medicine Teaching Hospital of Kangwon National University. A grade of 4 out of 6 systolic murmur with an irregular tachycardic rhythm was auscultated on both sides of the chest. Systolic blood pressure was 140 mmHg. Panting was noticed in the hospital, but there was no crackle sound. Blood analysis revealed mild increases in liver panel levels (alanine aminotransferase 149 [reference interval, 19-70] U/L; and alkaline phosphatase, 185 [reference interval, 15-127] U/L) and severe increases in cardiac biomarker levels (n-terminal pro-brain natriuretic peptide, 4169 [reference interval, 50-900] pmol/L; and cardiac troponin I, 0.22 [reference interval, 0.03-0.12] ng/mL). On electrocardiography, irregularly irregular supraventricular tachycardic rhythm with an f-wave and no distinct p-wave was observed. Generalized cardiomegaly with an enlarged right atrium and left ventricle was confirmed on thoracic radiography. Moreover, hepatomegaly and an enlarged caudal vena cava were observed. Echocardiographic evaluation revealed a fibromuscular diaphragm in the right ventricle. Because of the obstructive lesion in the right ventricle, the right atrium and ventricle were enlarged (right atrial area index, 38.82 cm2/m2 [reference interval, 4.2-10.2 cm2/m2]; right ventricle end-diastolic area index, 14.152 cm2/m2 [reference interval, 4.9-10.92 cm2/m2]). Accordingly, the patient was diagnosed with double-chambered right ventricle (DCRV). Pimobendan, furosemide, enalapril, diltiazem, and S-adenosylmethionine (SAMe) were prescribed, and all symptoms were relieved. DCRV is a right-sided congenital heart defect resembling pulmonic valve stenosis. If symptoms are not severe, medical therapy can be facilitated without surgery or the balloon dilation.

Marine Heat Waves Detection in Northeast Asia Using COMS/MI and GK-2A/AMI Sea Surface Temperature Data (2012-2021) (천리안위성 해수면온도 자료 기반 동북아시아 해수고온탐지(2012-2021))

  • Jongho Woo;Daeseong Jung;Suyoung Sim;Nayeon Kim;Sungwoo Park;Eun-Ha Sohn;Mee-Ja Kim;Kyung-Soo Han
    • Korean Journal of Remote Sensing
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    • v.39 no.6_1
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    • pp.1477-1482
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    • 2023
  • This study examines marine heat wave (MHW) in the Northeast Asia region from 2012 to 2021, utilizing geostationary satellite Communication, Ocean, and Meteorological Satellite (COMS)/Meteorological Imager sensor (MI) and GEO-KOMPSAT-2A (GK-2A)/Advanced Meteorological Imager sensor (AMI) Sea Surface Temperature (SST) data. Our analysis has identified an increasing trend in the frequency and intensity of MHW events, especially post-2018, with the year 2020 marked by significantly prolonged and intense events. The statistical validation using Optimal Interpolation (OI) SST data and satellite SST data through T-test assessment confirmed a significant rise in sea surface temperatures, suggesting that these changes are a direct consequence of climate change, rather than random variations. The findings revealed in this study serve the necessity for ongoing monitoring and more granular analysis to inform long-term responses to climate change. As the region is characterized by complex topography and diverse climatic conditions, the insights provided by this research are critical for understanding the localized impacts of global climate dynamics.

The Effects of Cultural Factors in Tourists' Restaurant Satisfaction: Using Text Mining and Online Reviews (문화적 요인이 관광객의 음식점 만족도에 미치는 영향: 텍스트 마이닝과 온라인 리뷰를 활용하여)

  • Jiajia Meng;Gee-Woo Bock;Han-Min Kim
    • Information Systems Review
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    • v.25 no.1
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    • pp.145-164
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    • 2023
  • The proliferation of online reviews on dining experiences has significantly affected consumers' choices of restaurants, especially overseas. Food quality, service, ambiance, and price have been identified as specific attributes for the choice of a restaurant in prior studies. In addition to these four representative attributes, cultural factors, which may also significantly impact the choice of a restaurant for tourists, in particular, have not received much attention in previous studies. This study employs the text mining technique to analyze over 10,000 online reviews of 76 Korean restaurants posted by Chinese tourists on dianping.com to explore the influence of cultural factors on the consumer's choice of restaurants in the overseas travel context. The findings reveal that "Hallyu (Korean Wave)" influences Chinese tourists' dining experiences in Korea and their satisfaction. Moreover, Korean food-related words, such as cold noodle, bibimbap, rice cake, pig trotters, and kimchi stew, appeared across all the review topics. Our findings contribute to the existing tourism and hospitality literature by identifying the critical role of cultural factors on consumers', especially tourists', satisfaction with the choice of a restaurant using text mining. The findings also provide practical guidance to restaurant owners in Korea to attract more Chinese tourists.