• 한국과학교육학회지
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• 제22권2호
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• pp.314-335
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• 2002

The purpose of this study was to investigate the effects of students' prior knowledge on scientific reasoning process performing a task of controlling variables with computer simulation and to identify a number of problems that students encounter in scientific discovery. Subjects for this study included 60 Korean students: 27 fifth-grade students from an elementary school; 33 seventh-grade students from a middle school. The sinking objects task involving multivariable causal inference was used. The task was presented as computer simulation. The fifth and seventh-grade students participated individually. A subject was interviewed individually while the investigating a scientific reasoning task. Interviews were videotaped for subsequent analysis. The results of this study indicated that students' prior knowledge had a strong effect on students' experimental intent; the majority of participants focused largely on demonstrating their prior knowledge or their current hypothesis. In addition, studnets' theories that were part of one's prior knowledge had significant impact on formulating hypotheses, testing hypothesis, evaluating evidence, and revising hypothesis. This study suggested that students' performance was characterized by tendencies to generate uninformative experiments, to make conclusion based on inconclusive or insufficient evidence, to ignore, reject, or reinterpret data inconsistent with their prior knowledge, to focus on causal factors and ignore noncausal factors, to have difficulty disconfirming prior knowledge, to have confirmation bias and inference bias (anchoring bias).

• 천문학회지
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• 제24권1호
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• pp.117-127
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• 1991

Here I report the confirmation of a long-term modulation of a period of $92^{+21}_{-13}$ years with the "time-delay correlation" method on the sunspot data compiled over the last a total of 289 years. This periodicity better specifies the cycle which falls pretty well within Gleissberg cycle, and clearly contrasts with the 55 year grand cycle which Yoshimura (1979) claimed. It is argued that the period-amplitude diagram method. which Yoshimura used, ana lysed peak amplitudes only so that a large number of data were disregarded, and thus was more susceptible to a bias. The planetary tidal force on Sun as for the possible cause to the solar activity was investigated and its possibility was ruled out in view of no period correlation between them.

• 한국인터넷방송통신학회논문지
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• 제22권3호
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• pp.25-30
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• 2022

본 연구는 러시아-우크라이나 전쟁(2022)의 특징인 유튜브 등 SNS 추천알고리즘 필터버블 강화현상과 하이브리드 전쟁의 승패 요인에 관한 연구이다. 이 전쟁은 하이브리드전으로 규명되며, SNS 추천알고리즘 기반 뉴미디어의 활용은 정치적 레버리지를 넘어서 전쟁의 승부를 결정짓는 요소로 부상하고 있다. 이로 인해, 필터버블 현상이 시청자들에게 노출되는 정보의 제한을 가져온다는 확증편향의 사전적 의미를 넘어서고 있다. 우크라이나 젤렌스키 대통령이 키예프에서 항전을 독려한 유튜브 동영상의 경우 702만의 조회 수를 기록했지만, 푸틴의 연설은 80만에 그친 것은 추천알고리즘이 푸틴의 연설을 노출하지 않았다는 방증이다. 이러한 SNS 추천알고리즘의 노출 전쟁은 미국(유튜브, 트위터, 페이스북)과 중국(틱톡) 빅테크 기업의 알고리즘 전쟁으로 발전되는 경향을 보인다. 미국기업의 영향으로 우크라이나는 국제적인 지원을 받을 수 있게 되었고, 러시아는 중국기업의 영향으로 푸틴의 지지율이 80 프로가 넘는 상반된 결과가 도출되고 있다. 이러한 알고리즘 권력화는 '필터버블'에 의해 여론의 확증편향에 기반을 두고 있기에 이 왜곡 현상에 대한 새로운 가이드라인 설정을 이른 시일 안에 제시해야 한다는 정당성이 이번 러시아-우크라이나 전쟁을 통해서 주목받고 있다.

• 한국융합학회논문지
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• 제7권6호
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• pp.205-212
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• 2016

본 연구는 한국 증권시장에서 과거 재무정보인 자본이익률(ROE)과 주가수익률(PER)를 이용해 가치투자 전략과 모멘텀 투자전략의 성과를 향상시킬 수 있는지 실증분석하였다. 본 연구는 가치투자전략과 모멘텀 투자전략 모두 ROE/PER가 높은 기업으로 구성된 포트폴리오의 투자성과가 종전의 가치투자전략이나 모멘텀 투자전략보다 높은 양(+)의 초과수익률을 나타냄을 관찰하였다. 본 연구는 이러한 초과수익률의 발생 원인을 설명하기 위해, 관련 심리학 분야의 선행연구를 이용한 융합적 접근방법으로, 증권시장 참여자들의 보수주의나 확증편향 같은 의사결정 행태의 불완전성이 초과수익의 원인이 될 수 있음을 토론하였다. 이는 증권시장에서 투자자들이 합리적으로 행동한다는 효율적시장 가설의 예측과 일치하지 않는 결과이다.

• 천문학회지
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• 제48권1호
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• pp.83-92
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• 2015

Recent large scale surveys such as Sloan Digital Sky Survey have produced homogeneous samples of multiple-image gravitationally lensed quasars with well-defined selection effects. Statistical analysis on these can yield independent constraints on cosmological parameters. Here we use the image separation statistics of lensed quasars from Sloan Digital Sky Survey Quasar Lens Search (SQLS) to derive constraints on cosmological parameters. Our analysis does not require knowledge of the magnification bias, which can only be estimated from the detailed knowledge on the quasar luminosity function at all redshifts, and includes the consideration for the bias against small image separation quasars due to selection against faint lens galaxy in the follow-up observations for confirmation. We first use the mean image separation of the lensed quasars as a function of redshift to find that cosmological models with extreme curvature are inconsistent with observed lensed quasars. We then apply the maximum likelihood test to the statistical sample of 16 lensed quasars that have both measured redshift and magnitude of lens galaxy. The likelihood incorporates the probability that the observed image separation is realized given the luminosity of the lens galaxy in the same manner as Im et al. (1997). We find that the 95% confidence range for the cosmological constant (i.e., the vacuum energy density) is $0.72{\leq}{\Omega}_{\Lambda}{\leq}1.0$ for a flat universe. We also find that the equation of state parameter can be consistent with -1 as long as the matter density ${\Omega}_m{\leq}0.4$ (95% confidence range). We conclude that the image separation statistics incorporating the brightness of lens galaxies can provide robust constraints on the cosmological parameters.

• Journal of Information Science Theory and Practice
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• 제10권1호
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• pp.59-72
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• 2022

This text discusses elements and characteristics of contemporary informational reality, that is, the ways of producing, circulating, organizing, using, and appropriating information in the current context. Initially, seven terms and concepts used to describe this reality are discussed: fake news, false testimonials, hate speech, scientific negationism, disinformation, post-truth, and infodemic. Next, an attempt is made to present a framework for such phenomena as an object of study in information science. Therefore, this scenario is characterized based on the three main models of information science study: physical, cognitive, and social. The contribution of each of them to the study of contemporary informational reality is analyzed, identifying aspects such as the bubble effect, clickbaits, confirmation bias, cults of amateurism, and post-truth culture. Finally, it presents the discussion of a possible veritistic turn in the field, in order to think about elements not covered so far by information science in its task and challenge of producing adequate understanding and diagnoses of current phenomena. In conclusion, it is argued that only accurate and comprehensive diagnoses of such phenomena will allow information science to develop services and systems capable of combating their harmful effects.

• Nutrition Research and Practice
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• 제12권4호
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• pp.336-341
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• 2018

BACKGROUND/OBJECTIVES: Dietary Reference Intakes (DRI) for energy are derived from total energy expenditure (TEE) measured using the doubly labelled water (DLW) method. The objective of this study was to assess the validity of DRI for predicting the energy requirements of elementary school-age children. SUBJECTS/METHODS: The present study involved 25 elementary school-age children aged between 9 and 11 years. TEE was assessed by the DLW method, and the results were compared with the TEE predicted by the DRI equations in order to evaluate accuracy. RESULTS: The subjects' TEE measured by the DLW method was $1,925.2{\pm}380.9kcal/day$ in boys and $1,930.0{\pm}279.4kcal/day$ in girls, whereas resting energy expenditure was $1,220.2{\pm}176.9kcal/day$ in boys and $1,245.9{\pm}171.3kcal/day$ for girls. The physical activity level was $1.58{\pm}0.20$ in boys and $1.55{\pm}0.13$ in girls. The mean bias between the predicted and measured TEE was 12.6% in boys and -1.6% in girls, and the percentage of accurate predictions was 28.6% and 63.6%, respectively. In boys, the equation resulted in underprediction of TEE among the subjects having low TEE values, whereas there was overprediction among subjects having high TEE values as shown by the Bland-Altman plot. On the contrary, this proportional bias was not observed in girls. CONCLUSIONS: The findings of this study suggest that the DRI equation for energy could result in the overestimation of energy requirements in elementary school-age boys. In the case of girls, the equations could be accurate at the group level. However, the DRI appears to be invalid for individual girls, as more than one third of girls had their TEE inaccurately predicted. We recommend more studies for confirmation of these results.

• Journal of Preventive Medicine and Public Health
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• 제32권4호
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• pp.427-434
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• 1999

Objectives: This study was conducted to determine, by reviewing the literature, whether treatment of Helicobacter pylori infection in patients with non-ulcer dyspepsia affects symptoms. Methods: We retrieved the literature using MEDLINE search, with nonulcer dyspepsia and Hericobacter pylori and treatment as key words, which were reported from 1984 to 1998, and manual literature search. The criteria for inclusion was as follows; 1) The paper should have confirmed nonulcer dyspepsia as case definition. 2) The paper should have peformed a randomized, blind trial. 3) Confirmation of Helicobacter pylori eradication should be done 4 weeks after treatment. 4) studies with no information on measurement of symptoms after treatment were not accepted. The percentage of patients with symptom improvement after eradication therapy for Helicobacter pylori infection was calculated. Cumulative odds ratio was compared by fixed effect model and random effect model as sensitivity and funnel plot was used to evaluate publication bias. Results: The overall effect size of symptom improvement was calculated by cumulative odds ratio. Cumulative odds ratio of random effect model was 4.16(95% CI: 1.55-11.19). Before integrating each effect sizes into common effect size, the homogeneity test was conducted and random effect model was selected(Cochran's Q=41.08 (d.f=10, p<0.001)). The heterogeneity across studies was evaluated and the different methodological aspects of studies led to differences between study results Conclusions: The results suggest that the eradication of Helicobacter pylori in patients with non-ulcer dyspepsia results more symptom improvement. In studios that shows the opposite results there are methodological aspects explaining the heterogeneity.

• 분석과학
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• 제33권1호
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• pp.23-32
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• 2020

Methamphetamine (MA) is the most common and available drug of abuse in Korea and its primary metabolite is amphetamine (AP). Detection of AP derivatives, such as MA, AP, phentermine (PT), MDA, MDMA, and MDEA by the use of immunoassay screening is not reliable and accurate due to cross-reactivity and insufficient specificity/sensitivity. Therefore, the analytical process accepted by most urine drug-testing programs employs the two-step method with an initial screening test followed by a more specific confirmatory test if the specimen screens positive. In this study, a gas chromatography-mass spectrometric (GC-MS) method was developed and validated for confirmation of MA and AP in human urine. Urine sample (500 µL) was added with N-isopropylbenzylamine as internal standard and ethyl chloroformate as a derivatization reagent, and then extracted with 200 µL of ethyl acetate. Extracted samples were analysed with GC-MS in the SIM/ Scan mode, which were screened by Cobas c311 analyzer (Roche/Hitachi) to evaluate the efficiency as well as the compatibility of the GC-MS method. Qualitative method validation requirements for selectivity, limit of detection (LOD), precision, accuracy, and specificity/sensitivity were examined. These parameters were estimated on the basis of the most intense and characteristic ions in mass spectra of target compounds. Precision and accuracy were less than 5.2 % (RSD) and ±14.0 % (bias), respectively. The LODs were 3 ng/mL for MA and 1.5 ng/mL for AP. At the screening immunoassay had a sensitivity of 100% and a specificity of 95.1 % versus GC-MS for confirmatory testing. The applicability of the method was tested by the analysis of spiked urine and abusers' urine samples.

• 통상정보연구
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• 제18권2호
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• pp.107-127
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• 2016

한-칠레 FTA발효 이후 10년 이상의 기간이 경과하였음에도 아직까지 국내거래단계에서의 원산지 정보 유통과 관리는 FTA활용 이익의 수출자 편향성과 발급유인 부족 등의 원인으로 원활하게 이루어 지지 않고 있다. 또한 발급 유통되고 있는 원산지증빙서류의 경우에도 정확성이 담보되지 않아 최종 수출자가 발급하는 원산지증명서에 오류를 유발할 수 있는 등 다양한 문제를 내포하고 있다. 이에 본 연구는 원산지(포괄)확인서의 발급과 유통을 장려할 수 있는 방안과 유통되는 국내거래단계 원산지정보의 정확성과 신뢰도를 제고하기 위한 방안을 찾아보았다. 이를 위해 본 연구에서는 우리 기업들의 원활한 FTA활용 지원을 위해 국내적 영역에서의 원산지(포괄)확인서의 유통 활성화와 오류 방지를 위한 제도적 보완책과 최종 수출자의 의도하지 않은 원산지증명서 오류로 인한 손실방지책의 도입방안을 제시하였다.