• Title/Summary/Keyword: Experimental bias

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The Experimental Bias in Person Perception as Results of the Method of Developments Stimulus (자극물의 표현방법에 따른 대인지각에서의 편파)

  • 김재숙;김희숙
    • The Research Journal of the Costume Culture
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    • v.12 no.1
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    • pp.28-40
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    • 2004
  • The purpose of this study was (1) to identify the experimental bias which could appear person perception as results of development methods (2) to find out the most desirable method in developments of stimulus. The research was a quasi experiment and the subjects were 358 male and female undergraduate students by convenient sampling. The experimental instruments consisted of a set of stimulus and semantic differential scales of 7-point bi-polar adjectives. The collected data were analyzed by Principle Component Analysis, ANOVA(analysis of variance), Scheffe's multiple range test. The independent variables were developing methods of stimulus(live person, photography of real person, 2 kinds of black and white line drawing, 2 kinds of color drawing). The results were as follows. First, five factors which were potency, sociality, appearance, evaluation, activity impressional dimensions emerged to account for the methods of development of stimulus. Second, the methods of development of stimulus had significant effects on potency, sociality, appearance, activity factors. In sociality factors, the impression of photographic stimulus was the closest to the live person's impression. However in the appearance and activity impressions, significant difference existed between live person and other developing stimulus. In the potency impression, black and white line-drawing gave the highest impressional bias. In the sociability and appearance impressions, color-drawing stimulus gave the highest impressional bias. Result: On conclusion the developments of stimulus can effect on stimulus person's impressions and these effects can produce experimental biases, the photographic stimulus gave the least impressional bias. The study shows that photography of real person will produce minimize measurement error.

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Development of the Bias-Cut Dress Pattern Making Method by Applying Fabric Draping Ratio

  • Park, Chan-Ho;Chun, Jong-Suk
    • The Research Journal of the Costume Culture
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    • v.20 no.4
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    • pp.594-603
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    • 2012
  • This study aimed to investigate a bias pattern making method with geometrical approach. The bias-cut dress has soft silhouette of drape in the garment. However, the bias cut dress has problem of satisfying the intended garment size spec. This problem occurs from various sources. The main reason is that the bias-cut fabric tends to stretch on longitudinal direction and to shrink horizontal direction when it was hung on the body. The goal of this study was to develop a bias-cut dress pattern making method satisfying the intended garment size spec. The researchers developed the geometrical method of measuring dimensional change by calculating the compensation ratio of the fabric in true bias direction. The compensation ratio was calculated by applying draping ratio of the fabric. Three types of fabrics were used in the experiment. The warp and weft crossing angle of fabric was ranged from $78^{\circ}$ to $82^{\circ}$. The fabrics stretched longitudinally 6.9~9.9% and shrank horizontally 7.2~11.0%. The compensation ratio of the bias-cut pattern for sample dress was calculated for each fabric type. Two types of experimental bias-cut dress patterns were developed for each fabric. One pattern was made with applying full compensation ratio and the other one made with applying partial ratio of the fabric. Experimental dresses were made with these patterns. The results of the evaluation showed that the bias-cut dress pattern applying the partial compensation ratio was more appropriate than the pattern applying the full compensation ratio.

Recognition and Attitudes toward Handicapped Persons : The Effects of an Anti-Bias Preschool Curriculum(Literature Approach) (문학적 접근을 통한 반편견 교육이 유아의 장애인에 대한 인식과 태도에 미치는 영향)

  • Cho, Eun Jin;Jung, Eun Young
    • Korean Journal of Child Studies
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    • v.23 no.4
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    • pp.153-169
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    • 2002
  • This study examined the effects of the Anti-Bias Curriculum(Literature Approach) on children's recognition and attitudes toward handicapped persons. The subjects were 54 non-handicapped 4-year-old kindergarten children. They were assigned to an experimental or a control group, with 27 children in each group. Instruments for the pre- and post-tests were the Survey of Child's Recognition of Handicapped Persons and the Child's Attitudes Toward Handicapped Persons Scale, respectively. The Anti-Bias program(Literature Approach) was developed and applied to the experimental group for 6 weeks. In the experimental group, differences were found between the pre- and post-test scores in recognition and attitudes toward handicapped persons.

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The experimental bias in person perception as results of presentation method of stimulus (자극물의 제시방법에 따른 대인지각에서의 편파)

  • 김재숙;김희숙
    • Journal of the Korean Society of Clothing and Textiles
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    • v.27 no.5
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    • pp.496-504
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    • 2003
  • The purpose of this study was (1) to identify the experimental bias which could appear person perception as results of presentation methods (2) to find out the most desirable method in presentation of stimulus. The research was a quasi experiment and the subjects were 773 male and female undergraduate students. The experimental instruments consisted of a set of stimulus and semantic differential scales of 7- point hi-polar adjectives. The collected data were analyzed by Factor Analysis, ANOVA(analysis of variance), Scheffe's multiple range test. The independent variables were presentation orders and presentation time of stimulus. The results were as follows: First, five factors which were potency, sociality, appearance, evaluation, activity impression dimensions emerged to account for the methods of development of stimulus. Second, the presentation order of stimulus in the combination of four stimuli sets had significant effects on the 3 impressional factors(sociality, appearance, evaluation). The presentation order of stimuli in the combination of eight stimuli set had significant effects on the 3 impressional factors(potency, sociality, appearance) and the presentation order of stimuli in the combination of eight stimuli set showed a significant effect on memorization of stimulus and the results support the recency effect. Third, the presentation time of stimuli had significant effects on the 2 impressional factors(potency, activity). 30 seconds presentation as well as free duration time resulted less experimental bias than 3 seconds presentation.

Power Amplifier Design using λ/4 DGS(Defected Ground Structure) Bias Line (λ/4 DGS 바이어스 선로를 이용한 전력증폭기 설계)

  • 정시균;정용채
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.9
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    • pp.924-931
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    • 2002
  • In this paper, a new λ/4 bias transmission line that is added dumbbell-shaped defected ground structure(DGS) on ground plane of the conventional λ/4 bias transmission line is proposed. This DGS λ/4 bias transmission line maintains high characteristic impedance, but physical width is wider and length is shorter than that of the conventional bias line. If the proposed bias line is attached on signal transmission line, this bias line can reduces the $3^{rd}$ harmonic signal as well as the$2^{nd}$ harmonic signal. With harmonic reduction characteristics, efficiency and linearity of amplifier are improved. The proposed bias line is adopted in power amplifier on IMT-2000 base-station transmitting band. This paper presents several simulations and experimental results of DGS to show validity of the proposed power amplifier using the new λ/4 bias transmission line. Experimental results represent that the $3^{rd}$ harmonic signal is reduced about 26.5 dB and efficiency is improved about 9.1 % and IMD3 is improved 4.5 dB than the conventional structure.

An Experimental Study on Temperature Measurement Bias using Thermocouple in Simulated Thermal Environments of Fire (모사된 화재의 열적환경에서 열전대를 이용한 온도 측정오차에 관한 실험적 연구)

  • Han, Ho-Sik;Yun, Hong-Seok;Hwang, Cheol-Hong;Kim, Sung-Chan
    • Journal of the Korean Society of Safety
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    • v.32 no.2
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    • pp.7-13
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    • 2017
  • An experimental study was conducted to identify the quantitative measurement bias for the bare-bead thermocouple (TC), which was widely used for measuring temperature in fire experiments. To this end, an apparatus could be controlled individually gas flow rate, preheating temperature and incident radiative heat flux was developed to simulate the thermal environments of fire. A relative measurement bias of bare-bead TC was evaluated with the comparison of double-shield aspirated TC. As a result, the relative measurement bias of bare-bead TC was gradually increased with the increase in radiative heat flux with constant gas temperature. The relative bias was also significantly increased with the decrease in gas temperature. Quantitatively, at the gas temperature of $20^{\circ}C$, the bare-bead TC had the relative bias of approximately 400% with the radiative heat flux of $20kW/m^2$ corresponding to thermal radiation level of the flashover. The present study was intend to provide fire researchers with methodologies for the reanalyses of temperature measured using bare-bead TC, radiation corrections, and validation of fire modeling.

A Study on the Optimal goods by Using Experimental Design in Marketing Research (시장조사에서 실험계획에 의한 최적상품 결정에 관한 사례연구)

  • Kim, Gwan-Rae
    • Journal of Korean Society for Quality Management
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    • v.15 no.2
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    • pp.69-73
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    • 1987
  • The aim of this study is to find out the optimal goods for the marketing research through analysing the factor effecting the marketing survey by using the experimental design method. The decisive effecting factors in relation with the marketing survey were investigated as follows; 1. A row effect (Ai; i = 1, 2, ... n) is the design sorts of woman-clothes bias. 2. A column effect (Bi; i = 1, 2, ... n) is the woman-consumer bias. In this paper the experimental design, execution and statistical analys is were conducted to find out the optimal goods for marketing research.

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Effect of Interface Roughness on Exchange Bias of an Uncompensated Interface: Monte Carlo Simulation

  • Li, Ying;Moon, Jung-Hwan;Lee, Kyung-Jin
    • Journal of Magnetics
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    • v.16 no.4
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    • pp.323-327
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    • 2011
  • By means of Monte Carlo simulation, we investigate the effects of interface roughness and temperature on the exchange bias and coercivity in ferromagnetic (FM)/antiferromagnetic (AFM) bilayers. Both exchange bias and coercivity are strongly dependent on interface roughness. For a perfect uncompensated interface a domain wall is formed in the AFM system during FM reversal, which results in a very small exchange bias. However, a finite interface roughness leads to a finite value of the exchange bias due to the existence of pinned spins at the AFM surface adjacent to the mixed interface. It is observed that the exchange bias decreases with increasing temperature, consistent with the experimental results. It is also observed that a bump in coercivity occurs around the blocking temperature.

Probing Effects of Contextual Bias on Number Magnitude Estimation

  • Xuehao Du;Ping Ji;Wei Qin;Lei Wang;Yunshi Lan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.18 no.9
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    • pp.2464-2482
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    • 2024
  • The semantic understanding of numbers requires association with context. However, powerful neural networks overfit spurious correlations between context and numbers in training corpus can lead to the occurrence of contextual bias, which may affect the network's accurate estimation of number magnitude when making inferences in real-world data. To investigate the resilience of current methodologies against contextual bias, we introduce a novel out-of-distribution (OOD) numerical question-answering (QA) dataset that features specific correlations between context and numbers in the training data, which are not present in the OOD test data. We evaluate the robustness of different numerical encoding and decoding methods when confronted with contextual bias on this dataset. Our findings indicate that encoding methods incorporating more detailed digit information exhibit greater resilience against contextual bias. Inspired by this finding, we propose a digit-aware position embedding strategy, and the experimental results demonstrate that this strategy is highly effective in improving the robustness of neural networks against contextual bias.

Indirect Kalman Filter based Sensor Fusion for Error Compensation of Low-Cost Inertial Sensors and Its Application to Attitude and Position Determination of Small Flying robot (저가 관성센서의 오차보상을 위한 간접형 칼만필터 기반 센서융합과 소형 비행로봇의 자세 및 위치결정)

  • Park, Mun-Soo;Hong, Suk-Kyo
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.7
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    • pp.637-648
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    • 2007
  • This paper presents a sensor fusion method based on indirect Kalman filter(IKF) for error compensation of low-cost inertial sensors and its application to the determination of attitude and position of small flying robots. First, the analysis of the measurement error characteristics to zero input is performed, focusing on the bias due to the temperature variation, to derive a simple nonlinear bias model of low-cost inertial sensors. Moreover, from the experimental results that the coefficients of this bias model possess non-deterministic (stochastic) uncertainties, the bias of low-cost inertial sensors is characterized as consisting of both deterministic and stochastic bias terms. Then, IKF is derived to improve long term stability dominated by the stochastic bias error, fusing low-cost inertial sensor measurements compensated by the deterministic bias model with non-inertial sensor measurement. In addition, in case of using intermittent non-inertial sensor measurements due to the unreliable data link, the upper and lower bounds of the state estimation error covariance matrix of discrete-time IKF are analyzed by solving stochastic algebraic Riccati equation and it is shown that they are dependant on the throughput of the data link and sampling period. To evaluate the performance of proposed method, experimental results of IKF for the attitude determination of a small flying robot are presented in comparison with that of extended Kaman filter which compensates only deterministic bias error model.