• Title/Summary/Keyword: Variance Ratio Test

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A Study on Balanced -type Oseillating Mole-Drainer(III)-Model Test for Draft Force, Torque, Power and Moment (평행식 진동탄환 암거 천공기의 연구(III)-견인력, 토크, 동력 및 모멘크에 관한 모형시험-)

  • 김용환
    • Journal of Biosystems Engineering
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    • v.1 no.1
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    • pp.1-6
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    • 1976
  • This paper is the third one of the study on balanced type oscillating mole-drainer, the first one was presented in No 9. Gyeongsang College Report and the second one in Vol. 17, No.4 of the KSAE. In the first part of this study, the characteristics of traction forces between the nonoscillating earth working equipments and oscillating ones was compared. A model of the balanced type oscillating mole-drainer, which composed of a mechanism that may reduce the machine vibration, was designed following the dimensional analysis and similitude technique. The model test was carried out to clarify the balancing mechanism of the oscillating parts and other parts of the machine. In the light of the results from the model tests, a prototype machine was made for experimental purpose. Results from the field test by a reported in the near future. In the second report, the model tests were carried out under the same soil conditions, i.e, . oscillating frequency, running velocity, and oscillating amplitude, etc. It was clear that use of balanced type oscillating model could substantially reduce the vibration of the whole system of the machine, when compared with the nonoscillating type model. In this paper(the third report), results of investigation on the traction force, power requirement, and moment. etc, is presented. Analysis of variance technique was used for analyzing the effect of the frequency, amplitude, and running velocity on the draft force, torque, power requirements, and moments. The results obtained from the model tests are as follows, 1) By practicing a balanced-type oscillating mole-drainer, it was possible to reduce the traction resistance by 55.1-61. 2 percent of traction resistance, however, was 1.75 - 1.95 times greater than the value of resistance which was induced by use of a mole-drainer with single bullet. The resistance of rear shank against soil was considered as a main causing factor of the above results. 2) As the oscillation frequency was increased, the traction resistance was decreased. Considering on the effect of oscillation the greater the amplitude, and the slower the running velocity was, the greater the reduction ratio of traction resistance was. 3) The ratio of the traction resistance of oscillating mole-drainer to that of non-oscillating one could be represented as a function of dimensionless variable (V/$Af$). The results from the tests were well agreed with the reported results from the experim ents on oscillation plow or hoe. 4) By taking a lower value of (V/$Af$), reducing the traction resistance was possible. This fact meant, however, that the efficiency of mole drain practice would be lower. 5) It was experimentally confirmed under the same condition of soil that the variable (R/$rD1^3$) could be represented as a function of a variable($V^2/gD$) when a non\ulcornerocillating mole-drainer was used. 6) When a oscillating mole-drainer was used, the variable(R/$rD_1^{3}$) could be represented as a function of two variables ($v^2/gD_1$) and (V^2/gD_1$). 7) The torque was not affected by a change of frequency. However, a relation of proportionality existed between torque and amplitude, running velocity, and ratio of bullet diameter. When a balanced type oscillating mole-drainer with two bullets was used, torque was increased by 52.8-78. 4 percent and total power requirement was also increased. 8) Total power requirement was increased linearly in accordance with the increasing frequency, 41.96 percent of total power was used for oscillating action. The magnitude of total power requirement was 1. 8-9. 4 times greater than that of a non-oscillating mechanism. In the view point of power requirement, it was not advisable to increase the frequency, amplitude, running velocity, and ratio of bullet diameter at the same time. 9) Only the positive moment occured in the rear shank. Change of the diameter of a rear bullet, could not affect the balancing against the soil resistance. It was necessary for rear bullet to have a large resistance against soil only when the rear bullet was in backward motion. 10) Within an extent of the experimental base, optimum limits for several design factors were A=0.5cm, $f$=22.5Hz, V=O. 05m/sec, and $\lambda$=1.0 By adapting these values traction resistance was reduced by 40 percent and vibration acceleration wa s reduced by 60 percent. Even though the total , power requirements for operating a balanced type oscillation mechanism was greater ~than that of non-oscillating one, using a oscillating mechanism would be more effective. Because a balanced type oscillating mechanism is used, tractive resistance will be reduced and then the lighter . tractive equipment could be used.

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Mixing and Oxygen Transfer Characteristics of Three Phase Fluidized Bed for Water Quality Management of Aquaculture (양어장 수질관리를 위한 삼상유동층 반응기의 혼합 및 산소전달특성)

  • LEE Byung-hun;KIM Jeong-sook;KANG Im-suk
    • Journal of Aquaculture
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    • v.7 no.4
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    • pp.239-249
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    • 1994
  • This study was conducted to elucidate mixing characteristics of the media to dertermine hydraulic model parameters of the three phase fluidized bed for the water quality management of aquaculture. The volume and H/D ratio of the reactor were 1.76 Liter and 10.9, respectively. The experimental results showed that variance $(\sigma^2)$ and dispersion number $(D/{\mu}L)$ were above 0.47 and $0.35\~\infty$, respectively. Therefore, the condition of the reactor was almost ideal complete mixing. The dependence of the overall oxygen-transfer coefficient $(K_{La})$ on each experimental variables through a multple linear regression was given by the following equation ; $$K_{La}\;=\;44.9(D_i/D_c)^{-0.4611}\;A_f^{0.8622}\;C_m^{-0.0746}\;d_p^{-0.4302}$$

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Effects of Aromatherapy on Stress Responses, Autonomic Nervous System Activity and Blood Pressure in the Patients Undergoing Coronary Angiography: A Non-Randomized Controlled Trial (아로마요법이 관상동맥조영술 대상자의 스트레스, 자율신경계, 혈압에 미치는 효과: 비무작위 대조군설계)

  • Song, Eun Jeong;Lee, Mi Young
    • Journal of Korean Academy of Nursing
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    • v.48 no.1
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    • pp.1-11
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    • 2018
  • Purpose: The purpose of this study was to examine the effects of aromatherapy on stress responses, autonomic nervous system (ANS) activity, and blood pressure in patients hospitalized to receive coronary angiography (CAG). Methods: A non-equivalent control group with a pretest-posttest design was used. The subjects were patients admitted to the day angiography room to receive CAG at E University Hospital (34 in the experimental group and 30 in the control group). The experimental group treatment was inhalation of the aroma oil blended with lavender, ylang-ylang, and neroli at a ratio of 4:2:1 twice before and after CAG. The measurements of stress index, ANS activity, and blood pressure were performed 5 times as follows: at admission, at pre-CAG after treatment I, at post-CAG, 2 hours after treatment II, and 4 hours after treatment II. The data were analyzed using the Mann-Whitney U Test and repeated-measures analysis of variance. Results: Significant interactions in the high frequency of ANS (F=5.58, p=.005) were observed between group and time. Stress index (z=2.14, p=.016), systolic blood pressure (z=4.14, p<.005), and diastolic blood pressure (z=3.28, p=.001) were significantly different between the experimental and control groups after 4 hours of treatment II. Conclusion: The findings showed that aromatherapy was not effective before CAG, but was effective after CAG. Therefore, aromatherapy can be used as a nursing intervention for patients receiving CAG.

The Analysis of Foot Shape of Elementary School Boys (학령기 남아의 발 형태 분석)

  • Seok, Eun-Yeong;Jeon, Eun-Gyeong;Park, Sun-Ji;Gwon, Suk-Hui
    • Journal of the Ergonomics Society of Korea
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    • v.23 no.2
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    • pp.1-12
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    • 2004
  • The purposes of this study were to investigate the relationship between anthropometric data of foot and other body sizes. to categorize the foot shape of elementary school boys and to find out determinant factors related the foot that enable us to deduce the foot shape and size for the design of more comfortable shoes. Subjects of this study were 249 elementary school boys of age ranged from 6 to 11 residing Seoul and lncheon area. Anthropometric sizes were measured with the direct measurement method using Martin scales and the indirect measurement method using digital photos. Pearson's correlation, factor analysis. cluster analysis. analysis of variance, post-hoc test, and cross tabs were performed for statistical analysis of the data by SPSS program. From the investigation on the relationship between foot-related items and body items, most items of foot measure were significantly related to body size items. However, angle of the foot did not related to other body sizes although other height items and mass items of the foot did have relationships with other body sizes. Results of ANOVA indicated there were significant differences in foot-related items except for items of foot angle and all body anthropometric items by subjects' age. This implicates big toe angle, little toe angle and foot ratio factors are required in sizing shoes besides foot length. On the basis of cluster analysis using factor scores. three different foot shapes were categorized. Type 1 was large and wide foot, Type 2 was small and narrow foot with large toe angle. and Type 3 was medium foot with no deformity on big toe. These three groups show significant differences in almost all measurement items. However, Rorher index and foot angle didn't show any significant differences among groups. This implicates the foot shape can be a determinant of shoe size.

Quantitative Evaluation of Median Nerve Motor Function in Carpal Tunnel Syndrome Using Load Cell : Correlation with Clinical, Electrodiagnostic, and Ultrasonographic Findings

  • Kim, Dong Hwan;Park, Sung Bae;Lee, Sang Hyung;Son, Young-Je;Chung, Gih Sung;Yang, Hee-Jin
    • Journal of Korean Neurosurgical Society
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    • v.54 no.3
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    • pp.232-235
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    • 2013
  • Objective : Major complaints of carpal tunnel syndrome (CTS) are sensory components. However, motor deficit also impedes functional status of hand. Contrary to evaluation of sensory function, the objective, quantitative evaluation of median nerve motor function is not easy. The motor function of median was evaluated quantitatively using load cell and its correlation with findings of electrodiagnostic study (EDS) was evaluated. Methods : Objective motor function of median nerve was evaluated by load cell and personal computer-based measurement system. All of the measurement was done in patients diagnosed as having idiopathic CTS by clinical features and EDS findings. The strength of thumb abduction and index finger flexion was measured in each hand three times, and the average value was used to calculate thumb index ratio (TIR). The correlation of TIR with clinical, EDS, and ultrasonographic findings were evaluated. Results : The TIR was evaluated in 67 patients (119 hands). There were 14 males and 53 females, mean age were 57.6 years (range 28 to 81). The higher preoperative nerve conductive studies grade of the patients, the lower TIR was observed [p<0.001, analysis of variance (ANOVA)]. TIR of cases with thenar atrophy were significantly lower than those without (p<0.001, t-test). TIR were significantly lower in patients with severe median nerve swelling in ultrasonography (p=0.042, ANOVA). Conclusion : Measurements of median nerve motor function using load cell is a valuable evaluation tool in CTS. It might be helpful in detecting subclinical motor dysfunction before muscle atrophy develops.

Typography for Efficient Visual Flow of Text Focused on Hangul (텍스트의 효율적 시각흐름을 위한 타이포그래피-한글을 중심으로-)

  • 신경주;김지현
    • Archives of design research
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    • v.11 no.3
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    • pp.187-196
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    • 1998
  • This study is intended to suggest the method of text arrangement in order to enhance visual perception which would help darify its communication. One hundred subjects without restriction of gender and profession participated in each experiment :their reading time was measured by the 0.01 second. The Analysis of Variance(two-way ANOVA without interaction) was performed for each experiment and the p value was 0.0001 which implies that there was a strong consistency among test results. Based on the first results, it is found that there is a consistent relationship between type size and text line length, and the following discovery was made ; the most effective ratio of type size to line length is approximately 1 :8. Judging from the Second and Third results, it seems that the vertical text arrangement is most efficient for reading regardless of text line length. So to make same rreading direction is more important than to narrow down the eye moving distance between column and column for efficient visual flow. This research supports the view that considering efficient eye movement on text, it is important to understand the mentioned variables that affect visual interpretation.

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QTL Analysis of Teat Number Traits in an F2 Intercross between Landrace And Korean Native Pigs

  • Park, Hee-Bok;Han, Sang-Hyun;Yoo, Chae-Kyoung;Lee, Jae-Bong;Cho, Sang-Rae;Cho, In-Cheol
    • Journal of Embryo Transfer
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    • v.31 no.4
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    • pp.313-318
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    • 2016
  • The aim of this study was to identify quantitative trait loci (QTLs) influencing teat number traits in an $F_2$ intercross between Landrace and Korean native pigs (KNP). Three teat number traits (left;right;and total) were measured in 1105 $F_2$ progeny. All experimental animals were genotyped with 173 informative microsatellite markers located throughout the pig genome. We detect that seven chromosomes harbored QTLs for teat number traits: genome regions on SSC1;3;7;8;10;11;and 13. Six of fourteen identified QTL reached genome-wide significance. In SSC7;we identified a major QTL affecting total teat number that accounted for 5.6 % of the phenotypic variance;which was the highest test statistic (F-ratio = 61.1 under the additive model;nominal $P=1.3{\times}10^{-14}$) observed in this study. In this region;QTL for left and right teat number were also detected with genome-wide significance. With exception of the QTL in SSC10;the allele from KNP in all 6 identified QTLs was associated with decreased phenotypic values. In conclusion;our study identified both previously reported and novel QTL affecting teat number traits. These results can play an important role in determining the genetic structure underlying the variation of teat number in pigs.

Correlation Analysis of Apoptosis and Cell Proliferating Marker (Ki-67) in Thyroid Tumors (갑상선 종양에서 아포프토시스(Apoptosis)와 세포증식 표지자(Ki-67)의 상관관계 분석)

  • Han, Kyung-Hee;Yang, Woo-Ick;Kim, Sun-Jung;Kim, Tai-Jeon
    • Korean Journal of Clinical Laboratory Science
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    • v.39 no.3
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    • pp.241-248
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    • 2007
  • To clarify the growth mechanisms of thyroid tumors, we investigated apoptotic cells in 88 thyroid tumors, consisting of 24 adenomas, 58 papillary thyroid carcinomas, and 6 undifferentiated carcinoma, using terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate digoxigenin-nick end labeling (TUNEL). The cell proliferating marker was also evaluated immunohistochemically using the monoclonal antibody to Ki-67 antigen (MIB-1) in the same tumors. The apoptosis was expressed as a percentage of the TUNEL-positive cells in the tumor cells, and a proliferating marker, being the percentage of Ki-67 positive cells, was counted up each tumor. The statistical analysis were used analysis of variance (ANOVA) and student's t-test that were analyze the differences in the rate of each histological types of the thyroid tumors. The overall level of apoptosis was extremely low in all histological types of the thyroid tumors analyzed, the mean apoptosis being $0.31{\pm}0.40$ in adenoma, $0.55{\pm}0.48 $in papillary thyroid carcinoma, and $4.60{\pm}3.27$ in undifferentiated carcinoma. The Ki-67 protein in the thyroid tumor subtypes was significantly lower in adenoma and papillary carcinoma, at $2.45{\pm}2.99$ and $6.27{\pm}4.42$, respectively, than that in undifferentiated carcinoma at $26.47{\pm}23.88$ (p<0.0001). There was no correlation between clinicopathological factors and apoptosis or Ki-67 in papillary thyroid carcinoma. In conclusion, our findings suggest that apoptosis occurs infrequently in thyroid tumor, and that cell proliferating maker Ki-67 markedly differs according to the thyroid tumor subtypes. Moreover, the ratio between proliferating cells and apoptotic cells may reflect thyroid tumor progression.

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Estimates of Direct and Maternal Effects on Growth Traits in Angora Rabbits

  • Niranjan, S.K.;Sharma, S.R.;Gowane, G.R.
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.8
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    • pp.981-986
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    • 2010
  • Genetic parameters of growth traits were estimated in the German Angora rabbit reared in the sub-temperate region of India. Estimates of (co)variance components were obtained for body weights at weaning (42 days) and post-weaning at 84, 126 and 168 days. A total of 8,324 animal records were used for the analysis of these traits. The data were analyzed by restricted maximum likelihood (REML) fitting six animal models with various combinations of direct and maternal effects. A log likelihood ratio test was used to select the most appropriate univariate model for each trait. Direct heritability estimates were observed to be moderate for the traits under study. Heritability estimates for weaning (42 d), 84, 126 and 168 d weights obtained from the best models were $0.25{\pm}0.05$, $0.17{\pm}0.05$, $0.21{\pm}0.06$ and $0.12{\pm}0.05$. Maternal effects had higher importance at weaning, and declined with the advancement of age. Significant maternal permanent environmental effect on weaning and post-weaning weights was a carryover effect of maternal influences during pre-weaning age. The estimated repeatabilities of doe effects on body weights were 0.37, 0.22, 0.18 and 0.28 at weaning, 84, 126 and 168 d body weight, respectively. Results indicated that modest rate of genetic progress is possible for body weight traits of Angora rabbit through selection. Similarly, these growth traits could be included in selection criteria along with wool traits for early selection of the animals.

A Comparative Study on the Competitiveness of the Alignment Zones in the Capital Area (수도권 정비 권역별 입지 경쟁력 비교 연구)

  • Kim, Dong-Yoon
    • Journal of The Korean Digital Architecture Interior Association
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    • v.11 no.3
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    • pp.79-88
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    • 2011
  • In the context of sustainability which is understood as equilibrium among three elements; human, space and time, the imbalance within the Seoul metropolitan area hinders its own area or the nation from development. Claims for the balanced development in the area are set up on the premise that there is a locational order of priority among the zones named 'overpopulation suppression', 'growth management' and 'conservation'. Based on the systematic consideration of competitiveness this study adopts the premise as a research hypothesis. Factor scales derived from the factor analysis, a kind of multivariate dependence analysis play an important role in this research process since they are measured by interval-ratio level and can be used for dependent variables in the statistical analysis. The hypothesis test carried out by means of the analysis of variance(ANOVA) concludes that the hypothesis assuming no difference in the competitiveness is rejected but the alternative hypothesis of the locational order mentioned above should be adjusted. Eigenvalues derived from the factor analysis could be used as weights for aggregate factor scales and the scales show that the priority is in the order of growth management - overpopulation suppression - conservation zones. This finding has also a significant implication that the countermeasures to cope with the lowering of the competitiveness resulted from the continuous and absolute restraints should be provided. And strategic approaches which are composed of key factors for each zone are deducted from in-depth review. (1) overpopulation suppression zone; health-welfare, educational base, public service factors, focusing on health-welfare one, (2) growth management zone; public service factor and (3) conservation zone; health-welfare, educational base factors, also focusing on health-welfare one.