• Title/Summary/Keyword: mean line

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Throughflow Analysis of Axial Flow Turbines - Comparison of Multi-streamline and Mean Line Methods - (축류터빈의 관통유동해석 - 다유선해석과 평균반경해석의 비교분석 -)

  • Kim, Tong Seop
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.22 no.8
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    • pp.1173-1182
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    • 1998
  • A throughflow analysis program for axial flow turbines is constructed, which can handle not only the two-dimensional multi-streamline (streamline curvature) method but also the one-dimensional mean line method. Calculations are performed for single stage and multi-stage axial flowturbines. For a wide operating range, the performance and flow field calculated by the present streamline curvature method are close enough to the test data. It is also revealed for the single stage turbine that the present analysis leads to far better correspondence with the experiment than other researchers" throughflow analyses. A special focus is put on the comparison of the results between the streamline curvature analysis and the mean line analysis. It is found that the mean line analysis can not predict the performance for highly off-designed conditions as accurately as the streamline curvature method, which shows the importance of considering the spanwise variation of loss and flow.

Comparisons between Two Different Eggshell Lines on Egg Traits and Egg Production Rate in Layers (계란의 형질들 및 산란율에 대한 난각색이 다른 두 계통간의 비교 연구)

  • 석윤오
    • Korean Journal of Poultry Science
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    • v.29 no.3
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    • pp.151-156
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    • 2002
  • The objective of this study was to compare the two different eggshell lines of commercial layers on egg traits and egg production rate. Hy-line W-98 (white shell line; WSL) and Hy-line Brown (brown shell line; BSL) were used as experimental stocks. The birds in each line were allocated to three floor pens each containing 25-birds. They were fed a ration containing 15.5% CP and 2,700 ㎉/kg ME, and were supplied 16 h of light per day throughout the experimental Periods. The egg traits and egg Production rate were measured from 53 to 56-wk-old and 20 to 56-wk-old, respectively. The mean egg weight and the mean percentage albumen were significantly heavier and higher (P<0.05) in the BSL than in the WSL, respectively. The mean eggshell thickness and the mean percentage shell were also significantly thicker and higher (P<0.05) in the BSL than those in the WSL, respectively. However, the mean percentage yolk and the yolk to albumen ratio showed a reverse trend as shown in the mean percentage albumen or percentage eggshell. Although the WSL birds started laying 4 d earlier than the BSL ones, the overall mean egg Production rate for BSL during 20 to 56 wk of age was significantly higher (P<0.05) by 6.6% than the WSL. It was concluded that the eggs of brown eggshell line had heavier egg weight and thicker shell, and they had more percentage of albumen, but less percentage of yolk than those of the white eggshell line. These results suggest that the brown eggshell line raised on the floor might be more beneficial than the white eggshell line not only for the preference of the table egg consumers, but also for the efficient production of the eggs.

Power System State Estimation and Identification in Consideration of Line Switching (선로개폐상태를 포함하는 전력통계 상태추정및 동정)

  • 박영문;유석한
    • 전기의세계
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    • v.28 no.3
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    • pp.57-64
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    • 1979
  • The static state estimation are divided into two groups; estimation and detection & identification. This paper centers on detection and identification algorithm. Especially, the identification of line errors is focused on and is performed by the extended W.L.S. algorithm with line swithching states. Here, line switching states mean the discrete values of line admittance which are influenced by unexpected line switching. The numerical results are obtained from the assumption that the noise vector is independent zero mean Gaussian random variables.

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Line-by-Level of Chitosan Interaction on Egg Traits and Yolk Cholesterol Level in Laying Hens (계란형질들과 난황 콜레스테롤 수준에 대한 닭의 계통과 키토산의 첨가 수준간의 상호작용 효과)

  • 석윤오;서형철
    • Korean Journal of Poultry Science
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    • v.29 no.2
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    • pp.81-88
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    • 2002
  • The objective of this study was to investigate the line-by-feed additive interaction on egg traits and yolk cholesterol level in laying hens. Hy-line W-98 (white shell line) and Hy-line Brown (brown shell line) were used as experimental stocks and three groups were assigned in each line. The age of hens used in this study were from 40- to 46-wk-old. Two different levels of chitosan were also used as additive in chicken diet. The first (CH$_{30}$) and second (CH$_{60}$) experimental groups were fed basal diet added 30mg and 60mg chitosan/kg feed, respectively. And the control group (CON) hens were fed with basal diet only. The eggs were collected and analyzed at the end of 40, 42, 44, and 46-wk-old. In the mean egg weight, the CH$_{30}$ in Hy-line Brown was significantly heavier (P<0.05) than CON, but the CH$_{30}$ in Hy-line W-98 was significantly lighter (P<0.05) than CON. Whereas, the mean egg weight did not significantly differ between CH$_{60}$ and CON in both line. The mean albumen percentage in Hy-line Brown did not show significant between experimental groups and control group. On the other hand, the mean albumen percentage of CH$_{60}$ in Hy-line W-98 was significantly lower (P < 0.05) than that of CON, but there was no significantly different between CH$_{30}$ and CON. In the mean yolk percentage, it showed a reverse trend as shown in the mean albumen percentage; there were significantly higher (P<0.05) in CH$_{60}$ than in CON fur the Hy-line W-98, and higher in CH$_{30}$ than in CON for the Hy-line Brown. However, the mean shell percentages did not significantly differ between experimental groups and control group in both lines. In the mean yolk cholesterol levels, the CH$_{30}$ and CH$_{60}$ in both lines were lower by 0.46 mg ∼2.80 mg per gram yolk than CON. Although the interaction effect of line-by-supplementing level of chitosan in hens diet on the pooled mean of yolk cholesterol level was no significant, it showed a highly significant interaction (P<0.01) at three of four experimental ages.

Anatomic Study of Pterygomaxillary Junctions in Koreans

  • Kim, Dong-Yul;Cho, Yeong-Cheol;Sung, Iel-Yong;Yun, Dae-Kawn;Kim, Min-Uk;Kim, Ji-Uk;Son, Hyung-Suck;Son, Jang-Ho
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.35 no.6
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    • pp.368-375
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    • 2013
  • Purpose: This study is to evaluate the location of descending palatine artery, the anatomy of pterygomaxillary junction, and the association between the obtained anatomic values and several variables. Methods: We studied 40 patients who were treated for dentofacial deformites from January 2010 to December 2012 in Ulsan University Hospital, Ulsan, Korea. Cone beam computed tomogram (CBCT) was done for all patients. The reference point was approximately 5 to 7 mm above anterior nasal spine on axial image. We evaluated the location of the greater palatine canal (line a: on the coronal view, the shortest line between the center of greater palatine canal and pterygoid fossa; distance a: the distance of line a). We also measured the thickness (line b: on the coronal view, the shortest line between maxillary posterior sinus wall and pterygoid fossa; distance b: distance of line b), width (line c: on the coronal view, the line perpendicular to the line b and the nearest line from the most concave point of lateral pterygoid plate to the medial pterygoid plate; distance c: distance of line c) and height (line d: on sagittal view, the vertically longest line of pterygoid junction; distance d: the distance of line d) in pterygomaxillary junctions. We evaluated the association between the obtained anatomic values and several variables (sex, age, height and weight). Results: The mean distance a was 4.78 mm, mean distance b was 5.53 mm, mean distance c was 8.01 mm and mean distance d was 13.22 mm. The differences between age and mean distance c and weight and mean distance d in pterygomaxillary junctions are statistically significant. Conclusion: There apparently is anatomic variation of pterygomaxillary junctions by various values, particularly weight and age in a Korean clinical population.

FE-based Strip Mean Temperature Prediction On-Line Model in Hot Strip Finishing Mill by using Dimensional Analysis (차원해석을 통한 열간 사상압연중 온도해석모델 개발)

  • 이중형;곽우진;황상무
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.05a
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    • pp.176-179
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    • 2003
  • The mean temperature prediction of strip is very important in hot strip finishing mill because of affecting on product quality and shape. Also, temperature can be used by basic information in other on-line control models with affecting control accuracy in factory. So, FE based on-line temperature model was developed for predicting strip mean temperature accurately in various process conditions and factory environments. There are many variables in affecting strip mean temperature in on-line states of factory. But some problems are occurred in considering all variables for making temperature model because of the bad efficiency of regression or fitting analysis. In this report, we have adopted dimensional analysis for solving these problems. We have many variables with dimensions affecting strip temperature but we are able to make non-dimensional variables less than dimensional variables from the combination of dimensional variables caused by PI-Theorem in fluid mechanics. The developed models are divided by two parts. The one is interstand temperature prediction model. The other is roll gap temperature model.

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Axial-Compressor Design with Mean-line Analysis and Vortex Method (평균유속법과 Vortex 방법을 사용한 축류압축기 설계)

  • Choi, Min-Suk;Yoon, Sugn-Ho;Baek, Je-Hyun
    • Proceedings of the KSME Conference
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    • 2001.06e
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    • pp.795-800
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    • 2001
  • In this study, a program to design a multi-stage axial compressor is developed wi th mean-line analysis and vortex methods. In a preliminary design stage, a method. to design in a short time is needed and mean-line analysis is usually used for this purpose. Arbitrary pressure ratio and reaction can be assigned to generate overall geometry and several vortex methods are adopted to consider the radial distribution of velocity and reaction. The variation of performance, when we use free vortex, forced vortex, and exponential method, is compared and discussed.

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The Effects of Mean-Line Shape on Longitudinal Stablility of a Wing in Ground Effect

  • Kim, Wu-Joan;Shin, Myung-Soo
    • Journal of Hydrospace Technology
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    • v.2 no.2
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    • pp.14-23
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    • 1996
  • The Reynolds-averaged Navier-Stokes equations for turbulent flow around a two-dimensional foil section moving ova. a flat surface (roller plate) is solved. The numerical method utilized the finite-difference schemes in collocated grids and the Baldwin-Lomax model is employed for turbulence closure. Calculations are carried out for three foil sections of different mean-line shape with various height ratio. As a foil approaches the bottom surface, the lift is augmented, while there exist some differences in pitching moment due to mean-line shape. It was found that the S-shaped mean line deteriorates lift characteristics but increases pitching moment to restore the designed height.

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Corrosion Loss of the Shell and the Bulkhead Plates of the Oil Tankers According to Their Age (유조선의 선각외판 및 격벽 부식도의 선령별 변화)

  • Park, Jung-Hee;Park, Si-Jung
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.18 no.1
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    • pp.17-23
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    • 1982
  • The corrosion loss of the shell plates and the bulkead plates of the oil tankers, nationalities of which belong to korea are determined and analyzed. The thickness of the plates are determined by use of the ultrasonic thickness meters at the check points set along the fore and aft line and the perpendicular to it. Difference between the original thickness and the determined one are given as the corrosion loss at the present age. 1. On the shell plates (1) The total mean of the corrosion loss shows the greatest value on the load water line in every age classes of the vessels. (2) The total mean of the corrosion loss on the fore and aft line shows little difference, even though it is slightly greater at the fore part, in every age classes of the vessels. (3) The corrosion loss along the perpendicular grows greater in the order of upper bilge line, light water line, freeboard line and load water line at 16 ages of the vessels, and the loss changes in the order of light water line, upper bilge line, freeboard line and load water line at 20 ages of the vessels. (4) The total mean of the corrosion loss along the light water line and upper and lower water line shows the greatest value on the fore part. That along the freeboard line and the load water line shows the greatest value on the midship part and on the after part, respectively. 2. On the bulkhead plates (1) The total mean of the corrosion loss shows the greatest value on the top part at the every age classes of the vessels. (2)The corrosion loss along the perpendicular grows greater in the order of the lower, center and upper part at every age classes of the vessels. (3) The total mean of the corrosion loss at the top part grows greater in the order of the transverse bulkhead of the side oil tank, that of center oil tank, longitudinal bulkhead of center oil tank, and transverse bulkhead of side water tank at the 20 ages of the vessels.

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A Study on the Morphological Diagrgmmings of Four Constitutiens (사상인(四象人)의 형태학적(形態學的) 도식화(圖式化)에 관(關)한 연구(硏究))

  • Huh, Man Hoee;Song, Jeong-Mo;Kim, Dal-Rae;Go, Byeong-Hui
    • Journal of Sasang Constitutional Medicine
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    • v.4 no.1
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    • pp.107-148
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    • 1992
  • The definitions of Four Constitution (Tae-Yang-In, So-Yang-In, Tae-Eum-In, So-Eum-In) in Four-Beginning-Theory (四端論) and Distribution-Theory (擴充論) were morphologically diagrammatized. the method of measuring the five parts came from the diagrams. The five parts are the followings; Top-Line is the distance between Rt. & Lt.Shoulders. Bosom-Line is the horizontal distance passing through the Rt. & Lt.nipples. Stomach-Line is the horizontal distance passing through the Rt. & Lt. acupuncture point Bool-Yong (不容穴). Navel-Line is the horizontal distance passing through the navel. Bottom-Line is the distance between the Rt.& Lt. anterior superior iliac spines. According to it, 311 people were measured in the clinic. Through the measured numerical values, to find out the objective propriety of the morphological diagrammings and the discriminating ability of Four Constitutions by the method of measuring the five, the author tried this study and got the following results. 1. On the ground of the Internal Organs-Theory (臟腑論), the definitions of Four Constitutions were classified and diagrammatized step by step and it was possible to draw the morphological graphs satisfying the reasonable condition objectively. 2. It was found that the graphings by Mean, Standard Deviation and 95% Confidence Interval for mean of the numerical values of five measured parts and the morphological diagrammings of the definitions in Four-Beginning Theory and Distribution-Theory drove to the same figures. 3. Through the method of the Analysis of variance and the Discriminant Analysis, it was discovered that the measured numerical values of five parts could distinguish the Four Constitutions. 4. Tae-Yang-In has the longest Top-Line and the shortest Bottom-Line. The Mean head of Confidence Interval from Top to Bottom is downwardly decreased at the rate of 3.7, 1.5, 1.8, 3.4. 5. So-Yang-In has the longest Top-Line and the shortest Bottom-Line. The Mean head of confidence Interval from Top to Bottom is downwardly decreased at the rate of 2.3, 1.5, 1.5, 1.1. 6. Tae-Eum-In has the longest Navel-Line. The Mean head of Confidence Interval from Navel to Top is upwardly decreased at the rate of 0.5, 0.4, 2.5 and downwardly decreased at the rate of 2.7 between Navel and Bottom. 7. So-Eum-In has the longest Bottom-Line. The Mean head of Confidence Interval from Bottom to Top is upwardly decreased at the rate of 1.1, 1.1, 1.8, 2.3. From the above findings, it was possible to draw the morphological graphings satisfying the objectively reasonable conditions in the definitions of Four-Beginning-Theory and Distribution-Theory and it was proved that the results of the Positive Analysis, carried with the measured numerical values of five parts from the diagramming, could show the objective propriety of the morphological graphings and the discerning ability of Four Constitutions by the method of measuring the five parts.

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