• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6A
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• pp.641-650
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• 2009

This paper presents new equations for member forces in concrete floating structures under wave loadings. The currently adopted design equations for wave loadings disregard the effect of mismatch between design wave length and the length of the structure. In most cases, however, additional internal forces occur due to disequilibriating buoyancy caused by the difference between design wave length and the length of the structure. In this study, new design equations considering the influence of the disequlibriating buoyancy is proposed. In addition, finite element solutions are sought to demonstrate the adequacy of the proposed design formulae in estimating the actual internal forces considering the structure as either rigid or flexible. It has been found that member forces are decreased approximately to around 55% for flexible model when compared with the rigid one.

• Journal of Sericultural and Entomological Science
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• v.9
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• pp.21-25
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• 1969

Various formulae for estimation of leaf production in mulberry trees were investigated and obtained. Four varieties of mulberry trees were used as the materials, and four characters. namely branch length (X, 1). branch diameter (X, 2). leaf number per branch (X, 3), and leaf area per branch (X, 4). were studies. The formulae to eatimate the leaf yield of mulberry trees are as follows: 1. Y$_1$v$_1$＝-115.760＋0.068X$_1$＋165.756X$_2$ Y$_1$v$_2$＝-221.500＋1.768X$_1$＋38.152X$_2$ Y$_1$v$_3$＝-253.826-0.116X$_1$＋289.507X$_2$ Y$_1$v$_4$＝ -157.559＋1.063X$_1$＋106.088X$_2$ where Y$_1$v$_1$, Y$_1$v$_2$, Y$_1$v$_3$, Y$_1$v$_4$, are showed the estimated yield of the each variety, namely Gaeryang souban, Ilchirye, Nosang. and Suwon Sang No. 4, respectively. X$_1$ and X$_2$ denote the measured values of branch length and branch diameter, respectively. 2. Y$\sub$7/v$_1$＝-118.478-0.665X$_1$＋184.445X$_2$＋2.346X$_3$ Y$\sub$7/v$_2$＝-217.432＋2.062X$_1$＋35.668X$_2$-1.058X$_3$ Y$\sub$7/v$_3$＝-206. 249-0.739X$_1$＋268.08X$_2$＋2.770X$_3$ Y$\sub$7/v$_4$＝-153.383＋0.009X$_1$＋2.024X$_2$＋0.171X$_3$where Y$\sub$7/v$_1$, Y$\sub$7/v$_2$, Y$\sub$7/v$_3$, Y$\sub$7/v$_4$, are the estimated yield of the each variety, namely Gaeryang. Souban, Ilichirye, Nosang, and Suwon Sang No. 4, respectively. X$_1$, X$_2$, X$_3$, denote the measured values of each character. branch length, branch diameter and leaf number per branch, respectively. 3. Y$\sub$11/v$_1$＝82. 567-1.283X$_1$＋15.501X$_2$＋0.640X$_3$＋3.511X$_4$ Y$\sub$11/v$_2$＝136.411＋0.311X$_1$＋1.921X$_2$-0. 217X$_3$＋0.214X$_4$ Y$\sub$11/v$_3$＝150.2Z7-0.139X$_1$＋11.788X$_2$＋0.143X$_3$＋0.381X$_4$ Y$\sub$11/v$_4$＝160.850＋0.323X$_1$＋66.076X$_2$-0.794X$_3$＋2..614X$_4$ where Y$\sub$11/v$_1$, Y$\sub$11/v$_2$, Y$\sub$11/v$_3$, Y$\sub$11/v$_4$, are the estimated yield values of four varieties, and X$_1$, X$_2$, X$_3$, X$_4$ denote the measured values of four characters. namely branch length, branch diameter. leaf number per branch and leaf area per branch. respectively. The estimation method of mulberry leaf yield by measurement of some characters, branch length. branch diameter. leaf number per branch and leaf area per branch. could be the better method to determine the leaf yield of mulberry trees without destroying the leaves and without weighting the leaves of mulberry trees than the other methods.

• Journal of Sericultural and Entomological Science
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• v.10
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• pp.35-40
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• 1969

Various formulae for estimation of spring leaf production in mulberry trees were calculated and obtained. Four varieties of mulberry trees were used as the materials, and four characters, namely branch length (X$_1$), node number (X$_2$), branch diameter (X$_3$) and branch number per stock (X$_4$) were studied. The formulae to estimate the leaf yield of spring mulberry trees are as follows: 1. $Y_1$v$_1$= -26.8939＋50.3950X$_1$＋1.1403X$_2$ $Y_1$v$_2$= -372.1091＋116.6371X$_1$＋0.1984X$_2$ $Y_1$v$_3$= 149.8203＋90.5125X$_1$-0.9775X$_2$ $Y_1$v$_4$= 108, 1496＋59.4533X$_1$＋1.4965X$_2$ Where $Y_1$v$_1$, $Y_1$v$_2$, $Y_1$v$_3$, $Y_1$v$_4$, are showed the estimated yield of the each variety, namely Gaeryang Seuban, Ilchirye, Nosang, and Suwon Sang No. 4, respectively. X$_1$ and X$_2$ denote the measured values of branch length and node number, respectively. 2. $Y_{7}$v$_1$= -54.4411＋32.9869c1.1127X$_2$＋21.7600X$_3$ $Y_{7}$v$_2$= -494.1480-1.8756X$_1$＋0.9788X$_2$＋110.0039X$_3$ $Y_{7}$v$_3$= 143.2836＋29.1779X$_1$＋0.1644X$_2$＋48.4135X$_3$ $Y_{7}$v$_4$= 1243.2549＋1.9454X$_1$＋2.7118X$_2$-75.6669X$_3$ Where $Y_{7}$v$_1$, $Y_{7}$v$_2$, $Y_{7}$v$_3$, $Y_{7}$v$_4$, are the estimated yield of the each variety, namely Gaeryang-Seuban, Ilchirye, Nosang, Suwon Sang No 4, respectively. X$_1$, X$_2$, X$_3$ denote the measured values of each character, branch length, node number, branch diameter and branch number per stock, respectively. 3. $Y_{11}$v$_1$=233.4780＋74.3713X$_1$＋1.2912X$_2$＋39.0420X$_3$-148.9300X$_4$ $Y_{11}$v$_2$=-317.0150＋15.l524X$_1$＋1.0861X$_2$＋156.7973X$_3$-148.3742X$_4$ $Y_{11}$v$_3$=178.7011＋29.8664X$_1$-0.2562X$_2$＋102.4632X$_3$-83.2693X$_4$ $Y_{11}$v$_4$= 264.0062＋47.7742X$_1$＋2.6996X$_2$＋92.8882X$_3$-192.3464X$_4$ Where $Y_{11}$v$_1$, $Y_{11}$v$_2$, $Y_{11}$v$_3$, $Y_{11}$v$_4$, are the estimated yield values of four varieties, and X$_1$, X$_2$, X$_3$, X$_4$, denote the measured values of four characters, namely branch length, node number, branch diameter and branch number per stock, respectively. The estimation method of mulberry spring leaf yield by measurement of some characters, in autumn the year before, could be the better method to determine the leaf yield of mulberry trees without destroying the leaves and without weighting the leaves of mulberry trees than the other methods.

• Journal of Korea Water Resources Association
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• v.42 no.8
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• pp.619-629
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• 2009

The objective of this study is to estimate bed-resistance in gravel-bed rivers using the equivalent roughness height($k_s$). We calculated the friction factor(f) with the measured data from 8 domestic gravel-bed rivers and investigated the size distributions of the bed materials. The averaged $k_s$ in each cross-section, which is determined under the hypothesis that the vertical velocity distribution follows the logarithmic law, is compared with the reach $k_s$ which is calculated with the cumulative grain diameter distribution curve of bed materials. Moreover, the applicability of existing formulae, such as Strickler type equations, is examined by comparing with Manning's n value converted from the $k_s$. According to the results, the reach $k_s$ proves to be a good indicator of representative characteristic of bed materials in a reach, and the Manning's n based on the reach $k_s$ is appropriate for practical estimation of the bed-resistance, for RMS errors between calculated and measured Manning's n is less than 0.003. The correlation between the $k_s$ and specified bed-material size($D_i$) is very low, so it is difficult to select a proper one among the existing empirical equations.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.4
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• pp.627-635
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• 2016

Recently, several construction projects have been built to create residential area, industrial complex and agricultural land on reclaimed on- and offshore regions. Estimating the quantity of filling materials during reclamation is the most curcial factor of the total construction cost of reclamation project. However, the estimation of loss ratio, defined as the ratio of loss amount to overall dumped amount, mostly depends on the empirical methods and formulae based on the material characteristics due to the lack of sufficient literature about the loss ratio according to hydraulic conditions. In this studies the loss ratio of materials considering flow conditions and material characteristics were examined through hydraulic experiments. A series of hydraulic experiments was conducted using five different hydraulic conditions and two types of materials such as sand and anthracite in a horizontal rectangular flume ($13.0m{\times}5.0m{\times}0.10m$), in which a round type revetment was installed. It is found that the loss ratio generally tends to increase with increasing the particle Froude number regardless of the types of materials. Also, when the flow velocity(u) becomes higher than the critical flow velocity ($u_c$), the loss ratios of sand and anthracite are dramtically increased up to 7.4% and 24.4%, respectively. As a future work, more specific mean velocities will be considered to figure out the loss ratio and more accurate estimation of amount of filling materials will be possible to present with confidence.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5B
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• pp.563-572
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• 2006

In designing the coastal structures, the accurate estimation of wave forces on them is very important. Recently, the empirical formulae such as Goda formula are widely used to estimate wave forces, as well as 2-D hydraulic and numerical model tests. But, sometimes, these estimation methods mentioned above seem to be unreasonable to predict 3-D structure of wave pressure on the coastal structures with 3-D plane arrangement in the real coastal area. Especially, in case of consideration of phase difference at harbor and seaward sides of the large-sized coastal structures like a composite breakwater, it is easily expected that the real wave pressures on each section of coastal structure have 3-D distribution. A new numerical model of 3-D Large Eddy Simulation, which is applicable to permeable structure, is developed to clarify the 3-D structure of wave pressures acting on coastal structure. The calculated wave forces on 3-D structure installed on the submerged breakwater show in good agreement with the measured values. In this study, the composite breakwater is adopted as a representative structure among the large-sized coastal structures and the 3-D structure of wave pressures on it is discussed in relation to the phase difference at harbor and seaward sides of it due to wave diffraction and transmitted wave through rubble mound.

• Journal of Sericultural and Entomological Science
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• v.10
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• pp.77-80
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• 1969

The purpose of this study is to find out reasonable method for the estimation of silk yield in cocoon layer. Two season's cocoons were used as the materials, and three characters, cocoon weight (X$_1$), cocoon layer weight (X$_2$), and cocoon layer ratio (X$_3$) were studied. The formulae to estimate the silk yield of cocoon weight are as follows: 1. Estimation of silk yield in cocoon weight of the spring cocoons. 1). the case of cocoon weight 200 cg above; Y= 12.93＋0.0863X$_1$＋0.2135X$_2$＋2.1137X$_3$ 2). the case of cocoon weight 180～200 cg; Y= 18.59＋0.1354X$_1$＋0.0763X$_2$＋1.7397X$_3$ 3). the case of cocoon weight 160～180 cg; Y= 133.39-0.4400X$_1$＋2.6595X$_2$-3.4364X$_3$ 4). the case of cocoon weight 160 cg under; Y-71.74-0.213X$_1$＋1.3100X$_2$-0.0101X$_3$ 2. Estimation of silk yield in cocoon weight of the autumn cocoons. 1). the case of cocoon weight 180～200 cg; Y=214.07-0.8078X$_1$＋4.1664X$_2$-6.8229X$_3$ 2). the case of cocoon weight 160～180 cg; Y=40.16-0.0264X$_1$＋0.1896X$_2$＋1.9299X$_3$ 3). the case of cocoon weight 130～160 cg; Y= 86.64-0.3352X$_1$＋1.6104X$_2$-0.2110X$_3$ 4). the case of cocoon weight 130cg under; Y=207.76-1.4579X$_1$＋7.7811X$_2$-6.9496X$_3$

• Journal of Sericultural and Entomological Science
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• v.8
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• pp.11-25
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• 1968

Various formulae for estimation of leaf production in mulberry trees were investigated and obtained. Four varieties of mulberry trees were used as the materials, and seven characters namely branch length. branch diameter, node number per branch, total branch weight, branch weight except leaves, leaf weight and leaf area, were studied. The formulae to estimate the leaf yield of mulberry trees are as follows: 1. Varietal differences were appeared in means, variances, standard devitations and standard errors of seven characters studied as shown in table 1. 2. Y$_1$=a$_1$X$_1$${\times}$P$_1$......(l) where Y$_1$ means yield per l0a by branch number and leaf weight determination. a$_1$.........leaf weight per branch. X$_1$.......branch number per plant. P$_1$........plant number per l0a. 3. Y$_2$=(a$_2$${\pm}$S. E.${\times}$X$_2$)+P$_1$.......(2) where Y$_2$ means leaf yield per l0a by branch length and leaf weight determination. a$_2$......leaf weight per meter of branch length. S. E. ......standard error. X$_2$....total branch length per plant. P$_1$........plant number per l0a as written above. 4. Y$_3$=(a$_3$${\pm}$S. E${\times}$X$_3$)${\times}$P$_1$.....(3) where Y$_3$ means of yield per l0a by branch diameter measurement. a$_3$.......leaf weight per 1cm of branch diameter. X$_3$......total branch diameter per plant. 5. Y$_4$=(a$_4$${\pm}$S. E.${\times}$X$_4$)P$_1$......(4) where Y$_4$ means leaf yield per 10a by node number determination. a$_4$.......leaf weight per node X$_4$.....total node number per plant. 6. Y$\sub$5/= {(a$\sub$5/${\pm}$S. E.${\times}$X$_2$)Kv}${\times}$P$_1$.......(5) where Y$\sub$5/ means leaf yield per l0a by branch length and leaf area measurement. a$\sub$5/......leaf area per 1 meter of branch length. K$\sub$v/......leaf weight per 100$\textrm{cm}^2$ of leaf area. 7. Y$\sub$6/={(X$_2$$\div$a$\sub$6/${\pm}$S. E.)}${\times}$K$\sub$v/${\times}$P$_1$......(6) where Y$\sub$6/ means leaf yield estimated by leaf area and branch length measurement. a$\sub$6/......branch length per l00$\textrm{cm}^2$ of leaf area. X$_2$, K$\sub$v/ and P$_1$ are written above. 8. Y$\sub$7/= {(a$\sub$7/${\pm}$S. E. ${\times}$X$_3$)}${\times}$K$\sub$v/${\times}$P$_1$.......(7) where Y$\sub$7/ means leaf yield estimates by branch diameter and leaf area measurement. a$\sub$7/......leaf area per lcm of branch diameter. X$_3$, K$\sub$v/ and P$_1$ are written above. 9. Y$\sub$8/= {(X$_3$$\div$a$\sub$8/${\pm}$S. E.)}${\times}$K$\sub$v/${\times}$P$_1$.......(8) where Y$\sub$8/ means leaf yield estimates by leaf area branch diameter. a$\sub$8/......branch diameter per l00$\textrm{cm}^2$ of leaf area. X$_3$, K$\sub$v/, P$_1$ are written above. 10. Y$\sub$9/= {(a$\sub$9/${\pm}$S. E.${\times}$X$_4$)${\times}$K$\sub$v/}${\times}$P$_1$......(9) where Y$\sub$7/ means leaf yield estimates by node number and leaf measurement. a$\sub$9/......leaf area per node of branch. X$_4$, K$\sub$v/, P$_1$ are written above. 11. Y$\sub$10/= {(X$_4$$\div$a$\sub$10/$\div$S. E.)${\times}$K$\sub$v/}${\times}$P$_1$.......(10) where Y$\sub$10/ means leaf yield estimates by leaf area and node number determination. a$\sub$10/.....node number per l00$\textrm{cm}^2$ of leaf area. X$_4$, K$\sub$v/, P$_1$ are written above. Among many estimation methods. estimation method by the branch is the better than the methods by the measurement of node number and branch diameter. Estimation method, by branch length and leaf area determination, by formulae (6), could be the best method to determine the leaf yield of mulberry trees without destroying the leaves and without weighting the leaves of mulberry trees.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.8-14
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• 2019

A drop structure, one of the representative river-crossing structures, is constructed to stabilize a riverbed. On the other hand, the structure interrupts the continuity of the river and causes the destruction of the hydro-ecological environment. Therefore, laboratory experiments of a natural type of drop structure with low differences were performed, and the empirical formula of a local scour hole is proposed. Four experimental flow rates were tested for various types of the drop structure models with 28 test cases. Based on the scour test, it was confirmed that the maximum scour depth occurs rather than the result of applying the previously proposed scour depth formulae. Correlation analysis of the major factors of scour hole at the downstream of the drop structure revealed a strong correlation between the upstream flow characteristics, drop structure height, and total crossing length of the drop model. In addition, the depth and length estimation formula of the maximum scour hole were proposed using the dimensionless variables and validated. In the future, it is also expected that more accurate scour prediction and calculation can be derived by conducting experimental studies and numerical analysis considering the various bed materials and flow conditions.

• Journal of the Korean Geotechnical Society
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• v.18 no.3
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• pp.51-59
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• 2002

This paper deals with development of a damage risk assessment system for adjacent buildings to under-passing tunnel face considering 3D-ground movement. The system consists of building and ground information module, monitoring data module, settlement evaluation module, and building damage risk assessment module. The major modules, settlement evaluation module and building damage assessment module, are based on settlement estimation model suggested by Attewell et al (1982) and the building damage assessment method by Mair et al. (1996). After estimating 3D-ground movements due to tunneling with settlement evaluation module, damage assessment far buildings is performed using building damage risk assessment module. The developed system has two major functions; 1) calculation of 3D-settlement with ground loss ($V_{s}$)or maximum settlement ($w_{max}$) and inflection point (i) using various empirical formulae, monitoring data, numerical results, and so on; 2) assessment of damage risk for adjacent buildings of arbitrary section with position change of tunnel face. The field data given by Boscadin and Cording (1989) leer the case of two-storied masonry building near the Metro tunnel in Washington D.C. was simulated to verify the applicability of the developed system.