• Title/Summary/Keyword: Experimental bias

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A Public Choice Study on the Use of the Central Bank's Reserved Profits: An Experimental Approach Through 61 Countries' Data (중앙은행 적립금의 운용에 관한 공공선택이론적 연구 - 61개국 자료를 이용한 실험적 접근 -)

  • Kim, Inbae;Kim, Iljoong;Kwon, Yunsub
    • KDI Journal of Economic Policy
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    • v.26 no.2
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    • pp.209-247
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    • 2004
  • Although various publicly reserved funds have recently come to the fore of academic and policy-making attention in Korea, researchers rarely take up the issue of the reserve fund retained from annual profits by the central bank (i.e., the Bank of Korea). Starting with the general public choice premise that bureaucrats seek to maximize their discretionary budget, this paper first provides a theoretical reasoning why central bank's bureaucrats would prefer retaining annual profits to turning them to the Treasury. The major tenet to be emphasized is that retained profits as a reserve fund can give the central bankers discretionary power in their disposition. In particular, we focus on the close relationship between the reserve fund and the discount windows. The latter, as a monetary instrument, has traditionally been demonstrated to cause secrecy, arbitrariness, and other bureaucratic amenities in the previous literature. Subsequently, this paper, based on 61 countries data, empirically verifies that the central bank's reserve fund is at least partially used to additionally increase the discount windows. Since an excessive use of discount windows results in inflationary bias, we conclude the paper with some policy suggestions to have such bureaucratic power of discretion in check. This paper, if in its experimental nature yet, is expected to shed a critical implication for establishing the meaningful independence of the central bank to a host of countries.

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Effect of Herbal Medicines on Preventing Restenosis After Percutaneous Coronary Intervention: A Systematic Review and Meta-analysis of Randomized Controlled Trials (경피적 관상동맥중재술 후 재협착 예방에 대한 한약의 효과 : 무작위배정 대조군 임상연구에 대한 체계적 문헌고찰 및 메타분석)

  • Nayeon Hur;Subin Ahn;Hongjun Kim;Insoo Jang
    • The Journal of Internal Korean Medicine
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    • v.44 no.3
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    • pp.387-401
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    • 2023
  • Objective: This study was conducted to investigate the preventive effect of herbal medicines on restenosis after percutaneous coronary intervention (PCI) by reviewing randomized controlled trials (RCTs). Methods: RCTs were searched for herbal medicine treatment after PCI using eight online databases (PubMed, CNKI, Wanfang, J-STAGE, OASIS, ScienceON, KTKP, and KISS). Studies that confirmed restenosis through coronary angiography at follow-up were selected according to the inclusion and exclusion criteria. The primary outcome was the restenosis rate, and the secondary outcome was the angina recurrence rate. Data were extracted from the final selected studies according to the research methodology and then analyzed with Review Manager 5.4.1. Study quality was assessed using Cochrane's risk-of-bias (RoB) tool. Results: Of the 252 papers obtained through the primary search, nine studies that met the selection criteria were finally selected. In these nine studies, herbal medicine combined with western medicine was used for the experimental group, and western medicine treatment was used alone for the control group. The meta-analysis result revealed that the restenosis rate and angina recurrence rate were significantly lower in the experimental group than in the control group (RR=0.34, 95% CI: 0.22-0.53, p<0.00001, I2=0% and RR=0.47, 95% CI: 0.29-0.78, p=0.004, I2=0%, respectively). Furthermore, the quality of studies assessed by Cochrane's RoB was low. Conclusions: This study showed that the combined treatment of herbal medicine and western medicine was effective in preventing restenosis and angina after PCI. As the number of papers included in this study was small, a large number of high-quality clinical studies should be considered in the future.

The psychological factors and impacts in lottery-purchasing decisions (복권 구매행동의 심리적 결정요인과 그 영향)

  • Taekyun Hur
    • Korean Journal of Culture and Social Issue
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    • v.10 no.3
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    • pp.19-36
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    • 2004
  • An experimental research investigated the components of lottery games affecting lottery-purchasing behaviors and the psychological consequences of the behaviors. In the experiment, participants were given a chance to purchase a lottery tickets during a series of computer games and their decision of purchasing the lottery ticket was measured. Also, the size and probability of the lottery games were manipulated and the perceived difficulty, satisfaction of the mid-outcome, and perceived probability of success in the computer game were measured in order to examine their impacts on participants' lottery-purchasing decisions. In addition, the behavioral tendency, satisfaction of the final outcome, and perceived self-capability in the computer game were measured at the end of the computer games in order to examine the effects of lottery-purchasing experiences on the variables. Participants who perceived the games as easier and estimated the probability of their success highly were more likely to buy the lottery tickets. However, the winning prize and odd of lottery tickets, perceived satisfaction of their own performance, and the performance itself did not influence the purchasing decisions. The common beliefs on the negative effects of lottery-purchasing experiences on human motivation and behaviors were not supported. The implications of the present research findings and limitations of the experimental research on lottery were discussed.

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Transplantation of human umbilical cord mesenchymal stem cells optimized with IFN-γ is a potential procedure for modification of motor impairment in multiple sclerosis cases: a preclinical systematic review and meta-analysis study

  • Mohamad Mahdi Esmaeili Araghi;Amir Abdolmaleki;Hadi Esmaeili Gouvarchin Ghaleh;Bahman Jalali Kondori;Akbar Ghorbani Alvanegh;Mehrdad Moosazadeh Moghaddam;Seyed Javad Hosseini Nejad Anbaran
    • Anatomy and Cell Biology
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    • v.57 no.3
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    • pp.333-345
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    • 2024
  • Stem cells transplantation (SCT) is known as a newfound strategy for multiple sclerosis (MS) treatment. Human umbilical cord mesenchymal stem cells (hUCMSCs) contain various regenerative features. Experimental autoimmune encephalomyelitis (EAE) is a laboratory model of MS. This meta-analysis study was conducted to assess the overall therapeutic effects of hUCMSCs on reduction of clinical score (CS) and restoration of active movement in EAE-induced animals. For comprehensive searching (in various English and Persian databases until May 1, 2024), the main keywords of "Experimental Autoimmune Encephalomyelitis", "Multiple Sclerosis", "Human", "Umbilical Cord", "Mesenchymal", and "Stem Cell" were hired. Collected data were transferred to the citation manager software (EndNote x8) and duplicate papers were merged. Primary and secondary screenings were applied (according to the inclusion and exclusion criteria) and eligible studies were prepared for data collection. CS of two phases of peak and recovery of EAE were extracted as the difference in means and various analyses including heterogeneity, publication bias, funnel plot, and sensitivity index were reported. Meta-analysis was applied by CMA software (v.2), P<0.05 was considered a significant level, and the confidence interval (CI) was determined 95% (95% CI). Six eligible high-quality (approved by ARRIVE checklist) papers were gathered. The difference in means of peak and recovery phases were -0.775 (-1.325 to -0.225; P=0.006; I2=90.417%) and -1.230 (-1.759 to -0.700; P<0.001; I2=93.402%), respectively. The overall therapeutic effects of SCT of hUCMSCs on the EAE cases was -1.011 (95% CI=-1.392 to -0.629; P=0.001). hUCMSCs transplantation through the intravenous route to the animal MS model (EAE) seems a considerably effective procedure for the alleviation of motor defects in both phases of peak and recovery.

Characteristics of Si Floating Gate Nonvolatile Memory Based on Schottky Barrier Tunneling Transistor (쇼트키 장벽 관통 트랜지스터 구조를 적용한 실리콘 나노점 부유 게이트 비휘발성 메모리 특성)

  • Son, Dae-Ho;Kim, Eun-Kyeom;Kim, Jeong-Ho;Lee, Kyung-Su;Yim, Tae-Kyung;An, Seung-Man;Won, Sung-Hwan;Sok, Jung-Hyun;Hong, Wan-Shick;Kim, Tae-You;Jang, Moon-Gyu;Park, Kyoung-Wan
    • Journal of the Korean Vacuum Society
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    • v.18 no.4
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    • pp.302-309
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    • 2009
  • We fabricated a Si nano floating gate memory with Schottky barrier tunneling transistor structure. The device was consisted of Schottky barriers of Er-silicide at source/drain and Si nanoclusters in the gate stack formed by LPCVD-digital gas feeding method. Transistor operations due to the Schottky barrier tunneling were observed under small gate bias < 2V. The nonvolatile memory properties were investigated by measuring the threshold voltage shift along the gate bias voltage and time. We obtained the 10/50 mseconds for write/erase times and the memory window of $\sim5V$ under ${\pm}20\;V$ write/erase voltages. However, the memory window decreased to 0.4V after 104seconds, which was attributed to the Er-related defects in the tunneling oxide layer. Good write/erase endurance was maintained until $10^3$ write/erase times. However, the threshold voltages moved upward, and the memory window became small after more write/erase operations. Defects in the LPCVD control oxide were discussed for the endurance results. The experimental results point to the possibility of a Si nano floating gate memory with Schottky barrier tunneling transistor structure for Si nanoscale nonvolatile memory device.

An Estimation of Concentration of Asian Dust (PM10) Using WRF-SMOKE-CMAQ (MADRID) During Springtime in the Korean Peninsula (WRF-SMOKE-CMAQ(MADRID)을 이용한 한반도 봄철 황사(PM10)의 농도 추정)

  • Moon, Yun-Seob;Lim, Yun-Kyu;Lee, Kang-Yeol
    • Journal of the Korean earth science society
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    • v.32 no.3
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    • pp.276-293
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    • 2011
  • In this study a modeling system consisting of Weather Research and Forecasting (WRF), Sparse Matrix Operator Kernel Emissions (SMOKE), the Community Multiscale Air Quality (CMAQ) model, and the CMAQ-Model of Aerosol Dynamics, Reaction, Ionization, and Dissolution (MADRID) model has been applied to estimate enhancements of $PM_{10}$ during Asian dust events in Korea. In particular, 5 experimental formulas were applied to the WRF-SMOKE-CMAQ (MADRID) model to estimate Asian dust emissions from source locations for major Asian dust events in China and Mongolia: the US Environmental Protection Agency (EPA) model, the Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model, and the Dust Entrainment and Deposition (DEAD) model, as well as formulas by Park and In (2003), and Wang et al. (2000). According to the weather map, backward trajectory and satellite image analyses, Asian dust is generated by a strong downwind associated with the upper trough from a stagnation wave due to development of the upper jet stream, and transport of Asian dust to Korea shows up behind a surface front related to the cut-off low (known as comma type cloud) in satellite images. In the WRF-SMOKE-CMAQ modeling to estimate the PM10 concentration, Wang et al.'s experimental formula was depicted well in the temporal and spatial distribution of Asian dusts, and the GOCART model was low in mean bias errors and root mean square errors. Also, in the vertical profile analysis of Asian dusts using Wang et al's experimental formula, strong Asian dust with a concentration of more than $800\;{\mu}g/m^3$ for the period of March 31 to April 1, 2007 was transported under the boundary layer (about 1 km high), and weak Asian dust with a concentration of less than $400\;{\mu}g/m^3$ for the period of 16-17 March 2009 was transported above the boundary layer (about 1-3 km high). Furthermore, the difference between the CMAQ model and the CMAQ-MADRID model for the period of March 31 to April 1, 2007, in terms of PM10 concentration, was seen to be large in the East Asia area: the CMAQ-MADRID model showed the concentration to be about $25\;{\mu}g/m^3$ higher than the CMAQ model. In addition, the $PM_{10}$ concentration removed by the cloud liquid phase mechanism within the CMAQ-MADRID model was shown in the maximum $15\;{\mu}g/m^3$ in the Eastern Asia area.

Effects of ad endorser's gaze directions on social perceptions and advertising effectiveness (광고 모델의 시선 효과: 모델의 사회적 특성 지각과 광고 효과성)

  • Kang, Jungsuk
    • Science of Emotion and Sensibility
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    • v.18 no.1
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    • pp.3-14
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    • 2015
  • An ad endorser's gaze direction is a salient nonverbal cue that consumers use in responding to advertisements. The gaze direction influences consumers' social perceptions (e.g., attractiveness, credibility) of the endorser and advertising effectiveness (e.g., advertising attitudes, brand attitudes). Especially, the cerebral emotional asymmetry hypothesis suggests that an ad endorser's left-averted gaze can produce more positive social perceptions and advertising effectiveness than the right-averted gaze for right-handed consumers. This study examined the effects of three gaze directions (direct, left-averted and right-averted gaze directions) of unknown female ad endorser on Korean males' advertising responses (attractiveness-, credibility- and ad-effectiveness-related responses), using online experimental method. The results indicated that the ad endorser's direct gaze was more likely to increase both positive (correspondence bias) and negative (suspicion, deceptiveness) social perceptions of her than the right-averted gaze. The direct gaze also created more positive advertising effectiveness (advertising attitudes) than the right-averted gaze. However, the study failed to find consistent differences in responses between left-averted gaze and either direct or right-averted gaze.

A Neural Network for Long-Term Forecast of Regional Precipitation (지역별 중장기 강수량 예측을 위한 신경망 기법)

  • Kim, Ho-Joon;Paek, Hee-Jeong;Kwon, Won-Tae
    • Journal of the Korean Association of Geographic Information Studies
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    • v.2 no.2
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    • pp.69-78
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    • 1999
  • In this paper, a neural network approach to forecast Korean regional precipitation is presented. We first analyze the characteristics of the conventional models for time series prediction, and then propose a new model and its learning method for the precipitation forecast. The proposed model is a layered network in which the outputs of a layer are buffered within a given period time and then fed fully connected to the upper layer. This study adopted the dual connections between two layers for the model. The network behavior and learning algorithm for the model are also described. The dual connection structure plays the role of the bias of the ordinary Multi-Layer Perceptron(MLP), and reflects the relationships among the features effectively. From these advantageous features, the model provides the learning efficiency in comparison with the FIR network, which is the most popular model for time series prediction. We have applied the model to the monthly and seasonal forecast of precipitation. The precipitation data and SST(Sea Surface Temperature) data for several decades are used as the learning pattern for the neural network predictor. The experimental results have shown the validity of the proposed model.

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Research on the Association Between Emotional Perception Bias and Deteriorated Visuospatial Attention Allocation Ability in Increasing the Level of Social Phobia (사회공포증 수준의 증가에 따라 나타난 정서지각 편향성과 시공간 주의배분능력 저하 간의 관련성 연구)

  • Kim, Sang-Yub;Jung, Jae-Bum;Nam, Ki-Chun
    • Science of Emotion and Sensibility
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    • v.23 no.2
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    • pp.35-50
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    • 2020
  • This study aimed to investigate the changes of emotional perception biases according to the level of social phobia and the relationship with visuospatial attention allocation ability. This study used the Korean self-report assessment test (Korean version of social avoidance and distress, K-SAD) to measure the level of social phobia. Moreover, the emotional perception and useful field of view (UFOV) tasks were employed for measuring emotional perception biases and visuospatial attention allocation ability, respectively. A total of 118 participants participated in this experiment, and only 107 (males: 94, females: 13) data were analyzed due to the exclusion of response errors and other statistical problems. The average age of the participants used in the analysis was 21 years (SD: 3.64), and those participants were divided into three groups according to the K-SAD scores. Consequently, all experimental groups showed negative emotional perception biases in the emotional perception task, but the magnitudes of the biases of each group were not significantly different. Furthermore, the positive emotional perception biases were higher at higher levels of social phobia, which could be related to the tendency of interpreting positive stimuli negatively. In the UFOV task, the higher the level of social phobia, the lower the visuospatial attention allocation ability. These results suggest that the deterioration of visuospatial attention allocation ability potentially contributes to the increase of positive emotional perception biases by being difficult to perceive external stimuli. Thus, this paper discusses the potential contribution of visuospatial attention allocation ability to the increased perceptual biases of positive emotions as the level of social phobia increases.

Meta-Analysis on the Effect of Serum Lipids Levels in Silkworm and Silkworm Pupae (누에와 누에번데기의 혈청지질에 미친 영향에 대한 메타분석)

  • Kim, Eun-Joo;Lee, So-Young;Kim, Ae-Jung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.11
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    • pp.273-282
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    • 2020
  • This study analyzed the physiological effects of silkworms and silkworm pupae on the reduction of serum lipid levels. Research data specific to silkworms and their pupae published over the last 10 years were collected and analyzed. A large effect size of 0.852 was observed in the overall results and the range of 95% confidence intervals was 0.662 to 0.999. The Q value was 23.264, the Higgin's I2 value was 92.217, indicating that each study was heterogeneous. There was no publication bias, as the corrected observed number of statistically significant effect sizes and the expected number of statistically significant effect sizes were both 0.654. The silkworm study showed a large effect size with respect to blood sugar and blood lipid reduction at 0.801 and 0.948, respectively, and LDL-cholesterol reduction at 1.371, showing a very large effect size. Aspartate transaminase / glutamic oxaloacetic transaminase (AST/GOT) was 0.768, alanine transaminase /glutamate-pyruvate transaminase (ALT/GPT) was 0.788, which was a medium effect size. The experiment period had a very large effect size of 1.170 for five to eight weeks and 1.020 for an intake of 1 to 50 mg/kg. The silkworm pupae had a large effect size of 0.991 and 0.951, respectively on blood lipids and total cholesterol reduction. The experimental period showed a very large effect size at 1.103 for more than nine weeks, and the intake showed a large effect size at 0.855 for 5001 mg/kg.