• Title/Summary/Keyword: S/M ratio

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Walking robot Optimum Design by Jansen's mechanism (Jansen's Mechanism 기반의 보행로봇 최적설계)

  • Kim, Taehyun;Seo, Hankook;Lee, Seohyun
    • Proceeding of EDISON Challenge
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    • 2016.03a
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    • pp.443-454
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    • 2016
  • This study focus to make 8 legs robot based on Jansen's mechanism. In the process of making, we found GL(Ground length),GAC(Ground Angle Coefficient) and the height difference of tract and compare Several models with M.Sketch to find link's Length ratio Optimised simple walking and crossing of obstacles. In the process, our team Analyzed the difference ideal tract (Jansen holy number model's track) contrived by Jansen and our final model tract. As a result, we found optimal link's length ratio to over the obstacles and some features that our model differ from Jansen holy number model. It means that optimal link's length ratio depends on certain circumstances, perfect length ratio is nonexistent.

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Harvesting Performance of the Experimental Pick-up Type Pulse Crop Harvester for Sprout Bean (시험용 수집형 두류 수확기의 나물 콩 수확성능)

  • Choi, Yeong-Soo;Yoo, Soo-Nam
    • Journal of agriculture & life science
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    • v.51 no.2
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    • pp.165-173
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    • 2017
  • To evaluate performance of the experimental pick-up type pulse crop harvester for harvesting sprout bean, its pick-up and discharging grain loss ratios, grain quality such as whole grain ratio, damaged grain ratio, unthreshed grain, and foreign material ratio in grain tank, germination rate of threshed grain, and theoretical field capacity of the harvester were analyzed according to engine speeds of 2000, 2400 and 2800 rpm and harvesting speeds of 0.6, 1.0 and 1.4 m/s. It is considered that the harvester showed optimum performance at the engine speed of 2800 rpm and the harvesting speed of 1.0 m/s, and then average pick-up grain loss ratio of 2.7%, discharging grain loss ratio of 0.5%, whole grain ratio of 99.3%, damaged grain ratio of 0.2%, unthreshed grain ratio of 0.0%, foreign material ratio of 0.2%, and germination rate at 8 days after seeding of 72.8% were shown. It is considered that the harvester has lower grain loss and higher grain quality than the imported bean combines. And also as it could harvest 3 rows of cut and dried sprout bean crop width of which was about 2 m, its effective field capacity was estimated for about 50 a/h.

A Study on the Rating of the Insureds' Anthropometric Data I. Build (피보험체계측치(被保險體計測値)의 평가(評價)에 관한 연구(硏究) 제1보(第1報) 체격(體格))

  • Im, Young-Hoon
    • The Journal of the Korean life insurance medical association
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    • v.3 no.1
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    • pp.103-141
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    • 1986
  • The present study was undertaken to establish the decision standard of builds for the insured by using the ratio of weight-for-height as build index. Materials being examined were the ratio of weight-for-height being calculated from the actually measured heights and weights of a total of 15,838 insured persons who were examined medically at Honam Medical Department of Dong Bang Life Insurance Company, Ltd. from June, 1979 to September, 1985. The ratio of weight-for-height is calculated by the following formula. The ratio of weight-for-height(%)=$\frac{weight(kg){\times}100}{\{height(cm)-100\}{\times}0.9(kg)$ The results were as follows: 1. The distribution of the ratio of weight. for-height of the 15,838 insureds follows Log normal distribution being skewed to the left(the direction of underweight). 2. The ratio of weight-for-height were Log transformed to lead to a sym metrical pattern of distribution in which statistical rules are known to be applied more exactly. Thereafter, the establishment of dicision standard of builds was undertaken by using the log of the ratio of weight-for-height as build index. Through all ages in male, the ratio of weight-for-height indicating the range of standard lives including slight overweighted and underweighted lives besides normal lives is 80-130%, and corresponds to $"M-2{\delta}"-"M+1.5{\delta}"$ and to $M{\pm}20%$ ; in female, 85-135%, and corresponds to $"M-2{\delta}"-"M+1.5{\delta}"$ and to $M{\pm}20%$. Through all ages in male, the ratio of weight-for-height indicating the initial level of super-overweighted and super-underweighted lives is 130-150% and 75-80%,and corresponds to $M+3{\delta}\;and\;M-3{\delta}$ and to M+40% and M-25% respectively;in female, 140-160% and 75-80%, and corresponds to $M+3{\delta}\;and\;M-3{\delta}$ and to M+40%-+50% and M-25% respectively. 3. Author's rating table model for builds(a table of weight per height) is proposed. On the table, the ratings for builds, i. e. standard, super-weighted and super-underweighted lives, are listed.

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The Eye/Brain Radioactivity Ratio for Assessment of Graves' Ophthalmopathy (Graves병 안구증에서 $^{99m}Tc-DTPA$ 뇌신티그라피를 이용한 안구/뇌 방사능비에 관한 연구)

  • Lee, B.W.;Sung, S.K.;Park, W.;Suh, K.S.;Choi, D.J.;Kim, J.S.
    • The Korean Journal of Nuclear Medicine
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    • v.22 no.1
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    • pp.27-31
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    • 1988
  • In Graves' disease, changes in orbital tissue and structure are casued by inflammatory infiltation, which induces increase of capillary permeability and breakdown of blood-tissue barriers. Using the uptake of $^{99m}Tc-DTPA$ in inflammatory lesion, Eye/Brain radioactivity ratios in brain scintigraphy were evaluated in 15 normal controls and 40 Graves' patients. The results were as follows; 1) Eye/Brain radioactivity ratio was significantly higher in Graves' ophthalmopthy group than in control group (p < 0.005). 2) In Graves' ophthalmopathy, Eye/Brain radioactivity ratio was significantly higher in active (progressive) group than in inactive (non-progressive) group (p < 0.05). 3) There was no correlation between class of ATA classification of Graves' ophthalmopathy and Eye/Brain radioactivity ratio. 4) There was no correlation between Eye/Brain radioactivity ratio and serum activity of TBII. In conclusion, Eye/Brain radioactivity ratio using $^{99m}Tc-DTPA$ brain scintigraphy may be useful to determine the activity of Graves' ophthalmopathy and whether treatment of Graves' ophthalmopathy is necessary or not.

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Analysis of Coefficiency According to Blade rpm Change in Tidal Current Power Generation System (조류발전 시스템 내 블레이드 회전수 변화에 따른 효율 특성 분석)

  • Lee, Uk Jae;Han, Seok Jong;Bak, Da In;Jeong, Shin Taek
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.31 no.5
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    • pp.314-319
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    • 2019
  • The numerical simulation method was used to analyze the flow velocity change and mechanical coefficient characteristics of the blade in the shroud system that changes with the initial flow velocity and the blade rpm. In the analysis condition, the initial flow velocity was varied from 0.35 m/s to 1.0 m/s, and the blade rpm varied from 50 rpm to 300 rpm. Through this, the mechanical coefficient was estimated. The flow velocity changes tended to increase more than 1.8 times at the middle point compared to the inlet. When the flow velocity ratio was 0.75 m/s compared to the initial flow velocity of 0.5 m/s, the flow velocity ratio decreased. The mechanical coefficient using the torque of the blade also showed the highest coefficient at 0.5 m/s, and the trends were similar. On the other hand, the maximum coefficient was estimated to be about 20.88% in TSR 4.77 when the initial flow velocity was 0.5 m/s. The mechanical coefficient analysis of blades in this study is expected to provide the basic data for hydraulic model experimental.

The Effect of The Flexural Strength Ratio on Beam-Column Joint with High and Low Strength Concrete (고강도와 보통 강도 콘크리트를 사용한 보-기둥 접합부의 휨강성화에 따른 이력거동)

  • Shin, S.W.;An, J.M.;Moon, J.I.;Kim, D.K.;Lee, K.S.;Park, H.M.;Lee, S.H.;Oh, J.G.
    • Proceedings of the Korea Concrete Institute Conference
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    • 1992.10a
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    • pp.185-190
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    • 1992
  • ACI318-89 Recommended that when the specified compressive strength of concrete in a column is greater than1.4 times that specified for a floor system, top surface of the column concrete shall extend 2ft(600mm)into the slab from the face of column to avoid unexpected brittle failure. The major variables are extension distance, flexural strength ratio(Mr), and shear reinforcement ratio(Vs). Test results are as follows ; (1) The failure modes of specimens under cyclic loading were concentrated at critical region from beam-column joint face. (2) Ductility index($\mu$f) were increased with increasing of shear confinement ratio and flexural strength ratio. (3)The specimens with 2ft extension distance showed more ductility than the specimens with 1ft extension distance.

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An Experimental Study on the Evaluation of Smear Effect Considering In-situ Conditions (현장여건을 고려한 스미어 영향 평가에 관한 실험적 연구)

  • Park, Yeong-Mog
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.8
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    • pp.85-94
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    • 2012
  • Evaluation of the smear effect caused by mandrel penetration into soft ground for a vertical drain installation is very important to predict the consolidation time of soft ground improvement. 30 kinds of laboratory model tests considering in situ conditions were conducted to investigate the formation of a smear zone and the decrease of coefficient of permeability in the disturbed zone. Three types(C(clay):M(silt)=1:1, 0.5:0.5, and 0:1) of reconstituted samples were used for 3 dimensional smear zone test. An experimental study was performed focusing on length of mandrel penetration, mandrel shape and size, earth pressure, and ground condition(unit weight and grain size distributions). Laboratory test results show that the length of mandrel penetration is the most critical factor for the formation of smear zone. As a result, the ratio between diameter of the smear zone($d_s$) and that of mandrel($d_m$) at field using long mandrel becomes larger than conventional $d_s/d_m$. The ratio between $d_s$ and $d_m$ ranges from 1.89 and 2.48 with the sample at C:M=1:0. It was also found that the $d_s/d_m$ value with the round shape of the mandrel is smaller than that of diamond one. The value of $d_s/d_m$ decreased with larger mandrel size, lower unit weight, and higher earth pressure. However, higher silt content led to increase of $d_s/d_m$. The ratio between coefficient of horizontal permeability in the smear zone($k_{hs}$) and that of undisturbed zone($k_{ho}$) ranged from 0.70 to 0.85. The test results imply that factors and values affecting $k_{hs}/k_{ho}$ show similar tendency with $d_s/d_m$.

Prediction of Poisson's ratio degradation in hygrothermal aged and cracked [θm/90n]s composite laminates

  • Khodjet-Kesb, M.;Adda bedia, E.A.;Benkhedda, A.;Boukert, B.
    • Steel and Composite Structures
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    • v.21 no.1
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    • pp.57-72
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    • 2016
  • The Poisson ratio reduction of symmetric hygrothermal aged $[{\theta}_m/90_n]_s$ composite laminates containing a transverse cracking in mid-layer is predicted by using a modified shear-lag model. Good agreement is obtained by comparing the prediction models and experimental data published by Joffe et al. (2001). The material properties of the composite are affected by the variation of temperature and transient moisture concentration distribution in desorption case, and are based on a micro-mechanical model of laminates. The transient and non-uniform moisture concentration distribution give rise to the transient Poisson ratio reduction. The obtained results represent well the dependence of the Poisson ratio degradation on the cracks density, fibre orientation angle of the outer layers and transient environmental conditions. Through the presented study, we hope to contribute to the understanding of the hygrothermal behaviour of cracked composite laminate.

Cutting-Pattern and Cutting Characteristics of the Reciprocating Cutter-bar of Combine Harvester(I) -Cutting Mechanism and Cutting Characteristics of the Standard Type Reciprocating Knife- (콤바인 예취장치의 절단특성에 관한 연구( I ) -절단현상 및 표준형 칼날의 절단특성-)

  • 정창주;이성범;인효석
    • Journal of Biosystems Engineering
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    • v.20 no.1
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    • pp.3-12
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    • 1995
  • This study was conducted to investigate the cutting mechanism of the reciprocating knife of combine harvester. The cutting operation of reciprocating knife was demonstrated through the cutting pattern diagram which was drawn by computer graphics. Various kinds and dimensions of standard-type reciprocating knives were analyzed by the developed program. The results are summarized as follows : (1) For the 50mm standard reciprocating knife, the bunching area and the maximum stalk-deflection were decreased rapidly according to the increase of cutting velocity ratio by 1.0 and decreased very slowly over this ratio. But, the secondary cut was occurred at ratio of 1.0 and increased rapidly over this ratio. (2) The 76mm standard knife showed better cutting mechanism than the 50mm, in two respects : the larger cutting area per one stroke and the lower revolutional speed of crank shaft for the same cutting velocity. (3) In respect to the bunching area and the secondary cutting length, the adequate height of 50mm standard reciprocating knife was 45~50mm. (4) In order to maintain the proper cutting mechanism, the adequate cutting velocity at forward speed of 0.5㎧ to 1.2m/s was from 0.4m/s to 1.2m/s for the standard knife.

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A Study on w6/w3 and P/M/S Ratios of Fatty Acids Ingested by University Students (일부 대학생의 지방산 섭취량과 섭취지방산의 w3, w6계 지방산 및 P/M/S 비율에 관한 연구)

  • 오경원;박계숙;김택제;이양자
    • Journal of Nutrition and Health
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    • v.24 no.5
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    • pp.399-407
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    • 1991
  • The purpose of this study was to estimate the intake of individual fatty acid and eventually to contribute to the establishment of dietary guidelines and recommendations of fatty acids for the Koreans. The subjects consisted of female college students aged 20 to 29 years old. Their dietary intake was assessed twice. in summer and in winter, by means of a 24-hour dietary recall method. Food models and other measuring tools were also used. Concentrations of serm total triglyceride, total cholesterol and HDL-& LDL-cholesterol were measured. The subjects consumed 12.3g of polyunsaturated fatty acids, 14.3g of monounsaturated fatty acids and 14.99g of saturated fatty acids per day The ratios of polyunsaturated/saturated fatty acids( P/S) and polyunsaturatedimonounsaturatedi saturated fatty acids (P/M/S) taken by the subjects were 0.8/1.0 and 0.8/l.0/l.0, respectively. The ratio of w61w3 fatty acids was found to be 8.3/l.0. All of these values seem to fall in the desirable range. The percentages of total calorie from carbohydrate. fat and protein were 59.4%, 23.4% and 17.2%, respectively. The concentrations of serum total triglyceride, total cholesterol. HDL-cholesterol and LDL-cholesterol were 59.3ms/dl, 192.7mg/dl, and 59.0mg/dl, and 121.9mg/dl., respectively.

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