• Title/Summary/Keyword: Difference-In-Difference

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The Relationship between Grip Strength and Ground Reaction Force by Change of Position when Lifting Tasks (들기 작업할 때 자세의 변화에 따른 악력과 지면 반발력의 상관관계)

  • Jung, Sang-Yong;Gang, Jin-Woo;Koo, Jung-Wan
    • Journal of the Ergonomics Society of Korea
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    • v.28 no.3
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    • pp.41-47
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    • 2009
  • The purpose of this study, during the lifting task was researching the difference and a relationship between the ground reaction force and the grip strength by change of position. After grip strength has measured in symmetry position and asymmetry position at 45cm and 75cm of height of hand, ground reaction force was measured by same attitude lifting wooden box. We analyzed the difference of grip strength and ground reaction force in each position change. The results of grip strength, the grip strength of both hand were significant difference that in study subject symmetry and asymmetry position (p<0.01). The results of symmetry lifting task, the study subjects was significant difference of the ground reaction force difference by height (p<0.05). Asymmetry lifting task was significant difference of ground reaction force difference by direction of rotation was changed (p<0.01). The result of it will rotate with non-dominant hand side of lifting tasks from height 75cm where it easily maintains a balance possibility and decreasing the load of the hand. Therefore, from the workshop in the work people, it will be between the height 75cm and non-dominant hand side of trunk rotatory direction in the lifting tasks. Future study is necessary researched about the change of grip strength when the height of the hand is higher, and the difference of the ground reaction force when the change of weight.

FRACTIONAL CHEBYSHEV FINITE DIFFERENCE METHOD FOR SOLVING THE FRACTIONAL BVPS

  • Khader, M.M.;Hendy, A.S.
    • Journal of applied mathematics & informatics
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    • v.31 no.1_2
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    • pp.299-309
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    • 2013
  • In this paper, we introduce a new numerical technique which we call fractional Chebyshev finite difference method (FChFD). The algorithm is based on a combination of the useful properties of Chebyshev polynomials approximation and finite difference method. We tested this technique to solve numerically fractional BVPs. The proposed technique is based on using matrix operator expressions which applies to the differential terms. The operational matrix method is derived in our approach in order to approximate the fractional derivatives. This operational matrix method can be regarded as a non-uniform finite difference scheme. The error bound for the fractional derivatives is introduced. The fractional derivatives are presented in terms of Caputo sense. The application of the method to fractional BVPs leads to algebraic systems which can be solved by an appropriate method. Several numerical examples are provided to confirm the accuracy and the effectiveness of the proposed method.

AN OVERLAPPING SCHWARZ METHOD FOR SINGULARLY PERTURBED THIRD ORDER CONVECTION-DIFFUSION TYPE

  • ROJA, J. CHRISTY;TAMILSELVAN, A.
    • Journal of applied mathematics & informatics
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    • v.36 no.1_2
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    • pp.135-154
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    • 2018
  • In this paper, an almost second order overlapping Schwarz method for singularly perturbed third order convection-diffusion type problem is constructed. The method splits the original domain into two overlapping subdomains. A hybrid difference scheme is proposed in which on the boundary layer region we use the combination of classical finite difference scheme and central finite difference scheme on a uniform mesh while on the non-layer region we use the midpoint difference scheme on a uniform mesh. It is shown that the numerical approximations which converge in the maximum norm to the exact solution. We proved that, when appropriate subdomains are used, the method produces convergence of second order. Furthermore, it is shown that, two iterations are sufficient to achieve the expected accuracy. Numerical examples are presented to support the theoretical results. The main advantages of this method used with the proposed scheme are it reduce iteration counts very much and easily identifies in which iteration the Schwarz iterate terminates.

On study for change point regression problems using a difference-based regression model

  • Park, Jong Suk;Park, Chun Gun;Lee, Kyeong Eun
    • Communications for Statistical Applications and Methods
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    • v.26 no.6
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    • pp.539-556
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    • 2019
  • This paper derive a method to solve change point regression problems via a process for obtaining consequential results using properties of a difference-based intercept estimator first introduced by Park and Kim (Communications in Statistics - Theory Methods, 2019) for outlier detection in multiple linear regression models. We describe the statistical properties of the difference-based regression model in a piecewise simple linear regression model and then propose an efficient algorithm for change point detection. We illustrate the merits of our proposed method in the light of comparison with several existing methods under simulation studies and real data analysis. This methodology is quite valuable, "no matter what regression lines" and "no matter what the number of change points".

Experimental Analysis for Variation of Pressure Difference on Flooding in PEM Fuel Cell at Cathode Channel Outlet (Cathode 출구 압력 변화에 따른 PEM Fuel Cell 내에서의 플러딩에 관한 실험적 연구)

  • Ahn, Deuk-Keun;Han, Seong-Ho;Kim, Kyoung-Rock;Choi, Young-Don
    • Transactions of the Korean hydrogen and new energy society
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    • v.20 no.5
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    • pp.390-396
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    • 2009
  • The flooding, especially in channel, is one of the critical issue to put proton exchange membrane fuel cell (PEMFC) to practical use. In this paper, channel flooding was investigated the pressure difference at cathode channel outlet. A ratio of pressure difference changes to 25, 50% as its variation rate. The pressure variable rate is reflected in dimensionless number FN. As a result, modified dimensionless number $FN^*$ correctly predicted the channel flooding. This study analyzes that a variety of pressure difference is how to affect flooding at the cathode of the PEMFC.

A Study of an Independent Evaluation of Prosody and Segmentals: With Reference to the Difference in the Evaluation of English Pronunciation between Native Speakers of English and Korean Learners of English (운율 및 분절음의 독립적 발음 평가 연구: 영어 원어민과 한국인 영어 학습자의 영어 발음 평가 차이를 중심으로)

  • Park, Han-Sang
    • Phonetics and Speech Sciences
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    • v.2 no.4
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    • pp.101-107
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    • 2010
  • This study investigates the difference in the evaluation of English pronunciation quality between native speakers of English and Korean learners of English. This study employs a novel method of independently evaluating the prosody and segmentals of English sentences. A set of stimuli were made by swapping the prosody and the segmentals of English sentences read by a native speaker of American English and a Korean learner of English. Evaluations of the difference level of stimuli pairs and the goodness of the pronunciation quality showed that both native speakers of English and Korean learners of English give priority to the segmentals but native speakers of English were more sensitive to the difference in prosody in the evaluation of English pronunciation.

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Automatic Detection of Work Distraction with Deep Learning Technique for Remote Management of Telecommuting

  • Lee, Wan Yeon
    • International journal of advanced smart convergence
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    • v.10 no.1
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    • pp.82-88
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    • 2021
  • In this paper, we propose an automatic detection scheme of work distraction for remote management of telecommuting. The proposed scheme periodically captures two consequent computer screens and generates the difference image of these two captured images. The scheme applies the difference image to our deep learning model and makes a decision of abnormal patterns in the difference image. Our deep learning model is designed with the transfer learning technique of VGG16 deep learning. When the scheme detects an abnormal pattern in the difference image, it hides all texts in the difference images to protect disclosure of privacy-related information. Evaluation shows that the proposed scheme provides about 96% detection accuracy.

Studies on the Separation of X and Y-Chromosome bearing Spermatozoa by Sedimentation in Boar Semen (침전에 의한 돼지의 X-와 Y-정자의 분이에 관한 연구)

  • 정용기;이용빈;임경순
    • Korean Journal of Animal Reproduction
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    • v.5 no.2
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    • pp.49-55
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    • 1981
  • This experiment was conducted to investigate the effects of temperature and time of sedimentation and dilutor on the a, pp.arance of B-body in top and bottom fractions at separation of X and Y- chromosome bearing spermatozoa in boar semen. 1. The top fraction showed higher a, pp.arence rate of B-body than the bottom. 2. Sixty minutes at 5 and 15$^{\circ}C$ and 90 min, at 25$^{\circ}C$ showed highest difference of B-body a, pp.arence rate between top and bottom fractions. The highest difference was shown in the treatments of Sg at 5$^{\circ}C$, C at 15$^{\circ}C$ and P at 25$^{\circ}C$. 3. The highest difference was shown in the treatments of 25$^{\circ}C$ and Sg for 30 min, 15$^{\circ}C$ and P for 60 min. and 25$^{\circ}C$ and P for 90 min. 4. Sixty minutes in C, P, S and Sg dilutors showed the highest difference. 5. 25$^{\circ}C$ of the temperature levels, 60 min of the time levels and P of the dilutor levels showed the highest difference. 6. The difference was given due to the individual boar.

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Investigations on Sex Ratio of offspring in Swine (돼지의 산자성비에 대한 조사)

  • 상병찬;박태진;박무균;한성욱
    • Korean Journal of Animal Reproduction
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    • v.8 no.2
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    • pp.92-96
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    • 1984
  • This study was carried out ot examine the sex ratios of offspring in swine. The sex ratios were obtained on the basis of the data from 15,892 pigs produced by 1,728 litters of Landrace, Large Yorkshire, Hampshire and Duroc breeds at National Animal Breeding Institute from 1975 to 1980. The results obtained are summarized as follows: 1. The sex ratio of total offspring was 51.47% for male and significant at 5% level, and Landrace and Duroc breeds were 51.46% and 52.27% for male and significant at 5% level, respectively, but no significant difference between the breeds. 2. The sex ratio of offspring by years was 52.74% for male and significant at 5% level in 1979, but no significant difference for other years and between years. 3. The sex ratio of offspring by seasons were a little highly 51.65% and 51.25%, for male in spring and autumn, but no significant difference, respectively. 4. The sex ratio of offspring by parities were 52.65% and 55.81% for male in groups of the 3rd to 4th and the 5th to 6th parity, and significant difference at 5% and 1% level, respectively. 5. The sex ratio of offspring by groups of litter size was 52.65% for male in 1 to 6 heads group, and significant difference at 5% level, but no significant difference between groups of litter size.

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The Prosodic Characteristics of Children with Cochlear Implant with Respect to the Articulation Rate, Pause, and Duration (인공와우이식 아동의 운율 특성 - 조음속도와 쉼, 지속시간을 중심으로 -)

  • Oh, Soonyoung;Seong, Cheoljae
    • Phonetics and Speech Sciences
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    • v.4 no.4
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    • pp.117-127
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    • 2012
  • This research reports the prosodic characteristics (including articulation speech rate, pause characteristics, duration) of children with cochlear implants with reference to those of children with normal hearing. Subjects are 8-to 10-year-old children, balancing each number of gender as 24. Dialogue speech data are comprised of four types of sentence patterns. Results show that 1) there's a statistically meaningful difference on articulation speech rate between the two groups. 2) On pauses, they are not observed in exclamatory and declarative sentences in normal children. While imperative sentences show no statistical difference on the number of pauses between the two groups, interrogative sentences do. 3) Declarative, exclamatory, and interrogative sentences reveal statistical difference between the two groups in terms of the sentence's final two-syllable word duration, showing no difference on imperative sentences. 4) When it comes to the RFP (duration ratio of sentence final syllable to penultimate syllable), we no statistically meaningful difference between the two groups in all types of sentences exists. 5) Lastly, RWS (the ratio of sentence final two syllable word duration to that of whole sentence duration) shows statistical difference between two groups in imperative sentences, but not in all the rest types.