Rib Shape Research Articles

Four New Equisetites Species (Sphenophyta) from the Hojedk Formation, Middle Jurassic (Bajocian-Bathonian), the North of Kerman, Iran

Middle Jurassic (Bajocian-Bathonian) Sphenophyta fossils of the silicified level peats of the Pabdana Coal Mine (Kerman) recovered. Four new species of Sphenophyta described for the first time. They include Equisetites pabdanaii sp. nov., Equisetites sparseii sp. nov., Equisetites hojedkii sp. nov. and Equisetites irregularii sp. nov.,. Descriptions of the above mentioned new species has been done based on their exclusive length of internodes, rib shapes, grooves, jointed stems, ribs density, number of grooves and form of nodes location. Recovered specimens include huge stems, which their length and width ranges are 260-310mm and 140-150mm respectively. Recognized species are associated with some Bajocian –Bathonian genera including: Nilssonia, Podozamites and Phlebopteris. Comparison of the recognized species with equisetums to some parts of Gondwana indicated that the Kermanian equisetums are similar to those of Australia, China, Afghanistan, central and south of Europe. Therefore, the Kerman Basin was a part of Gondwana during the Bajocian – Bathonian time interval.

End-bearing resistance of Y-type perfobond rib according to rib width–height ratio

A Y-type perfobond rib shear connector has a higher shear resistance and ductility than a conventional perfobond rib shear connector, and can address the issues of low vertical resistance and the constructability of transverse rebars. This study focuses on push-out tests for verifying the performance of Y-type perfobond rib shear connectors. These tests are conducted according to the guidance provided in Eurocode-4. Previous studies on Y-type perfobond rib shear connectors aimed to verify their shear performance using parameters such as the concrete strength, the presence of transverse rebar, the thickness of the rib, and the Y-shaped bending angle of the ribs. However, there are scant attempts to clarify the effects from different rib widths and heights. The end-bearing resistance of the Y-type perfobond rib shear connector may be determined by the sizes of the rib width and rib height. Therefore, the end-bearing resistance is comparatively analyzed in this study according to the rib widths and rib heights. On the basis of the push-out test results, the shear resistance equation presented by Kim et al. [14,15] are improved. The improved equation is able to more rationally consider the effects from various rib shape factors and compressive strengths of concrete.

Design Modifications to Improve the Antishock Performance of a Stamped Base for a 2.5-in HDD

This paper presents a modified design for a stamped base for a 2.5-in hard disk drive (HDD). A stamped base is a thinner thickness and lower stiffness than a die-casting base. To improve shock performance of the stamped base, the finite element (FE) model of the HDD is constructed. Then, the FE model was verified by modal analysis. Drop test was performed to confirm the shock simulation model. Parametric analysis was used to identify the key parameters for the shock performance which were the base thickness, rib shape, number of ribs, and reinforcement. The correlation between the relative displacement and natural frequency of the HDD was investigated for each parameter. The dominant parameter was identified and applied to the FE model of the stamped base. The modified stamped-base model was then evaluated under nonoperational shock conditions.

Influence of wall ribs on the thermal stratification and self-pressurization in a cryogenic liquid tank

Self-pressurization in a cylindrical ribbed tank which is partially filled with liquid hydrogen is investigated numerically under different rib spacing-to-height ratios. The Volume of Fluid (VOF) method is employed as well as a phase change model. Appropriate models are incorporated into the Ansys Fluent by the user-defined functions to carry out the computations. The ribbed surface is modeled as a finned surface and a conjugate transient heat transfer problem is formulated for predicting fluid flow currents and heat transfer. The effect of rib material and shapes is also studied. Numerical results indicate that the pressure rise can be reduced by ribs mounted on the tank wall. This phenomenon is more pronounced as the rib spacing-to-height ratio is reduced. A vortex is observed in the downstream region of each rib when the spacing-to-height has a relatively high value. Evaporation occurs as time elapses due to heat accumulation at the rib surfaces. Pressure starts to rise later with high thermal conductivity ribs and becomes higher with low thermal conductivity ribs when the ribs are of identical configuration in geometry. The final pressure rise seems to be monotonically versus increasing time. The semicircular ribs perform better than rectangular ones in control of the pressure rise and thermal stratification for identical cross sectional area and if the locations are kept the same.

철근 마디형상에 따른 부착특성에 관한 해석적 연구

기존의 많은 연구자들이 철근과 콘크리트 사이의 부착특성에 영향을 주는 다양한 변수에 대하여 연구해왔으며, 특히 최근에는 고강도철근의 등장과 더불어 부착강도의 증진을 위한 연구가 다수 진행 중이다. 철근과 콘크리트 사이의 부착특성은 두 이질재료 사이의 계면조건이 중요한 역할을 하게 되는데, 이 중에서 특히 철근의 마디형상은 계면조건에 가장 큰 영향을 미치게 된다. 본 연구에서는 철근과 콘크리트 사이의 부착거동을 분석할 수 있는 상용 비선형 유한요소프로그램을 사용하여 철근의 마디형상에 따른 부착특성에 대하여 연구하였다. 해석에 사용된 부착모델은 2차원 평면응력요소를 사용하였으며, 주요 해석변수로는 마디각, 마디높이, 마디간격 및 마디면적비이다. 해석결과, 마디각은 30~60도인 범위에서 부착력이 우수한 것으로 나타났으며, 마디높이는 일정구간까지는 부착강도가 증가하나 철근직경의 12%를 초과하면 전단파괴를 유발하여 오히려 부착강도가 감소되고, 마디간격에 대한 효과는 상대적으로 크지 않은 것으로 나타났다. 마디의 높이와 간격을 하나의 지표로 제시할 수 있는 마디면적비는 부착강도의 변화를 효과적으로 나타낼 수 있는 것으로 분석되었으며, 마디면적비는 0.15 이하에서 최대의 효율을 나타내는 것으로 분석되었다. 특히 대형마디(교차마디형상)를 가진 철근인 경우, 타 변수보다 우수한 효율을 나타내어 부착강도 증진효과가 커지는 것으로 평가되었다. Effects of various parameters on bond property between reinforcing bar and concrete are investigated in many researchers, and various study is on going to improve the bond strength. Properties of interface between reinforcement and concrete is important role in bond property. This study analyzed the interfacial bond mechanism between deformed bar and concrete by finite element analysis (FEA) to evaluate the effect of rib shape. The FEA model in this study is simplified 2D plane stress model. The variables of analysis are selected by rib angle, rib height, rib spacing and relative rib area. From the results of analysis, reinforcing bars with rib angle <TEX>$30{\sim}60^{\circ}$</TEX> showed better bond strength than the others. Bond strength ratio following to the rib height is proportionally increased up to the <TEX>$0.12d_b$</TEX>, but rib spacing has little effect on bond strength. The results also indicated that relative rib area can be efficiently represented the properties of deformed shape in reinforcing bars, and zigzagged rib height shape showed excellent bond strength increase.

Experimental investigations on the stability of stiffened cylindrical shells of steel silos

Owing to technological reasons the silos are frequently supported in a discrete way, usually by column heads. This kind of support causes a significant accumulation of compression meridional stresses in a cylindrical shell in support regions, which may lead to local buckling. The problem of determining shell resistance over the support region for different shapes of ribs constitutes a current research issue. One of highly preferred methods of strengthening this zone is the use of short ribs interconnected with a circumferential ring. Both the results of tests on the resistance of such shells and numerical analysis allowing to determine the course of this research are presented in this study. It has been demonstrated that the global resistance of the stiffened shells supported discretely is always much smaller from that in similar shells supported uniformly around the perimeter.

Heat transfer and friction factor correlations for multiple arc shape roughness elements on the absorber plate used in solar air heaters

Incorporating artificial roughness on the underside of the absorber plate is an established effective and economic method for improving the thermal performance of a solar air heater. The present experimental investigation is undertaken to analyze the effect of various geometrical parameters for multiple arc shape ribs on heat transfer and friction characteristics. The experiments carried out encompasses Reynolds number (Re) in the range of 2200–22,000, relative roughness height (e/D) values of 0.018–0.045, arc angle (α) range of 30–75° and relative roughness width (W/w) ranges from 1 to 7 and relative roughness pitch (p/e) range of 4–16. Thorough experimentation has been conducted to accumulate data on heat transfer and friction characteristics of a rectangular duct roughened solar air heater. Utilizing these experimental data, correlations for Nusselt number and friction factor are also developed.

Evaluation of heat transfer performances of various rib shapes

The heat transfer and friction loss performances of rib-roughened rectangular cooling channels having a variety of cross-sectional rib shapes were analyzed using three-dimensional Reynolds-averaged Navier–Stokes equations. Numerical simulations were conducted for sixteen rib shapes: square, isosceles triangular, fan-shaped, house-shaped, reverse cut-trapezoidal, cut-trapezoidal, reverse boot-shaped, boot-shaped, reverse right-angle triangular, right-angle triangular, reverse pentagonal, pentagonal, reverse right-angle trapezoidal, right-angle trapezoidal, isosceles trapezoidal, and semicircular ribs. The ratios of pitch, height, and width of the rib to hydraulic diameter of the channel were set to 10, 0.047, and 0.047, respectively. The Reynolds stress model was used with the Speziale–Sarkar–Gatski pressure–strain model to analyze the turbulence. The computational results for the area-averaged Nusselt number were validated by comparison with the experimental data under the same conditions. The effects of the Reynolds number and rib pitch-to-width ratio on the performances of various ribs were also investigated for Reynolds numbers of 5000–50,000 and rib pitch-to-width ratios of 5.0–10.0, respectively. The new boot-shaped rib design showed the best heat transfer performance with a pressure drop similar to that of the square rib.

An historical review and new taxa in the Madeiran endemic genusMonizia(Apiaceae, Apioideae)

The monotypic genus Monizia (Apiaceae) endemic to Madeira was published by Richard Thomas Lowe in 1856. Several authors have considered different taxonomic arrangements either by merging the genus with Thapsia or with Melanoselinum. Recent molecular data suggested a clear-cut separation of both Monizia and Melanoselinum from Thapsia but also from Tornabenea, a genus that is endemic to the Cape Verde Islands. The genus Monizia was initially recorded on one single island of the archipelago of Madeira; it was later reported on two other islands of the same archipelago and also in the Selvagens archipelago. Only recently, Monizia was found to occur on one of the islets of Porto Santo. In the present work, Monizia is retained as a monotypic genus and four subspecies of Monizia edulis are described and illustrated, based on morphological traits: two on the island of Madeira, namely M. edulis subsp. isambertoi and M. edulis subsp. giranus; one on Deserta Grande, namely M. edulis subsp. edulis; and one on Porto Santo, namely M. edulis subsp. santosii. These new taxa are distinguished in generic terms by their differences in stem and umbel length, the degree of division of the radical leaves and arrangement of ultimate segments, dimensions of calyx teeth, style orientation and length, mericarp size and shape, mericarp texture, and mericarp rib size and shape. Typification of the genus Monizia, its species and subspecies, descriptions, present-day geographical distribution, habitats, conservation status, synonymy and a comprehensive key to the new taxa are presented and discussed.

Detection and registration of ribs in MRI using geometric and appearance models.

Magnetic resonance guided high intensity focused ultrasound (MRgHIFU) is a new type of minimally invasive therapy for treating malignant liver tissues. Since the ribs on the beam path can compromise an effective therapy, detecting them and tracking their motion on MR images is of great importance. However, due to poor magnetic signal emission of bones, ribs cannot be entirely observed in MR. In the proposed method, we take advantage of the accuracy of CT in imaging the ribs to build a geometric ribcage model and combine it with an appearance model of the neighbouring structures of ribs in MR to reconstruct realistic centerlines in MRIs. We have improved our previous method by using a more sophisticated appearance model, a more flexible ribcage model, and a more effective optimization strategy. We decreased the mean error to 2.5 mm, making the method suitable for clinical application. Finally, we propose a rib registration method which conserves the shape and length of ribs, and imposes realistic constraints on their motions, achieving 2.7mm mean accuracy.

Air/mist cooling in a rectangular duct with varying shapes of ribs

A numerical investigation of turbulent forced convection in a three-dimensional channel with periodic ribs on the lower channel wall is conducted. The lower wall is subjected to a uniform heat flux condition while the upper wall insulated. This study was conducted to investigate the forced convection, flow friction, and performance factor in a horizontal air and air/mist cooled rectangular duct, with various shaped ribs. Calculations are carried out for square ribs (case A), triangular ribs (case B), and trapezoidal ribs (case C and case D) cross sections over a range of Reynolds numbers (8000–20,000), constant mist mass fraction (6%), and fixed rib height and pitch. To investigate turbulence model effects, computations based on a finite volume method are carried out by utilizing three turbulence models: the standard k-ω, Omega Reynolds stress, and shear stress transport turbulence models. The predicted results from using several turbulence models reveal that the shear stress transport turbulence model provides better agreement with available measurements than others. It is found that the average mist cooling enhancement is about 1.8 times. The air/mist provides the higher heat transfer enhancement over air with trapezoidal-shaped ribs (38°, case C).

Numerical Prediction of Turbulent Flow and Heat Transfer Enhancement in a Square Passage With Various Truncated Ribs on One Wall

Repeated ribs are often employed in the midsection of internal cooling passages of turbine blades to augment the heat transfer by air flowing through the internal ribbed passages. Though the research of flow structure and augmented heat transfer inside various ribbed passages has been well conducted, previous works mostly paid much attention to the influence of rib topology (height-to-pitch, blockage ratio, skew angle, rib shape). The possible problem involved in the usage of ribs (especially with larger blockage ratios) is pressure loss penalty. Thus, in this case, the design of truncated ribs whose length is less than the passage width might fit the specific cooling requirements when pressure loss is critically considered. A numerical study of truncated ribs on turbulent flow and heat transfer inside a passage of a gas turbine blade is performed when the inlet Reynolds number ranges from 8000 to 24,000. Different truncation ratio (truncated-length to passage-width) rib geometries are designed and then the effect of truncation ratio on the pressure drop and heat transfer enhancement is observed under the condition of constant total length. The overall performance characteristics of various truncated rib passages are also compared. It is found that the heated face with a rib that is truncated 12% in length in the center (case A) has the highest heat transfer coefficient, while the heated face with a rib that is truncated 4% at three locations over its length, in the center and two sides (case D), has a reduced pressure loss compared with passages of other designs and provides the lowest friction factors. Although case A shows larger heat transfer augmentation, case D can be promisingly used to augment side-wall heat transfer when the pressure loss is considered and the Reynolds number is relatively large.

Characterization of the Centroidal Geometry of Human Ribs

While a number of studies have quantified overall ribcage morphology (breadth, depth, kyphosis/lordosis) and rib cross-sectional geometry in humans, few studies have characterized the centroidal geometry of individual ribs. In this study, a novel model is introduced to describe the centroidal path of a rib (i.e., the sequence of centroids connecting adjacent cross-sections) in terms of several physically-meaningful and intuitive geometric parameters. Surface reconstructions of rib levels 2-10 from 16 adult male cadavers (aged 31-75 years) were first extracted from CT scans, and the centroidal path was calculated in 3D for each rib using a custom numerical method. The projection of the centroidal path onto the plane of best fit (i.e., the "in-plane" centroidal path) was then modeled using two geometric primitives (a circle and a semiellipse) connected to give C1 continuity. Two additional parameters were used to describe the deviation of the centroidal path from this plane; further, the radius of curvature was calculated at various points along the rib length. This model was fit to each of the 144 extracted ribs, and average trends in rib size and shape with rib level were reported. In general, upper ribs (levels 2-5) had centroidal paths which were closer to circular, while lower ribs (levels 6-10) tended to be more elliptical; further the centroidal curvature at the posterior extremity was less pronounced for lower ribs. Lower ribs also tended to exhibit larger deviations from the best-fit plane. The rib dimensions and trends with subject stature were found to be consistent with findings previously reported in the literature. This model addresses a critical need in the biomechanics literature for the accurate characterization of rib geometry, and can be extended to a larger population as a simple and accurate way to represent the centroidal shape of human ribs.

Topology optimization using multistep mapping from 2D photomask to 3D structure for designing reinforcing rib

We developed a topology optimization method for designing a two-dimensional (2D) photomask. The optimization employs multistep mapping compatible with micromachining processes to improve the characteristics of a three-dimensional (3D) MEMS fabricated by the photomask. We used this method in the development of an electrostatic micromirror to design the most effective reinforcing rib shape that reduces the deformation caused by internal residual stress. Employing a dot-array pattern as the initial topology, the optimization calculation converged after 300 iterations for predicted 79.1% reductions in maximum displacement. To verify this result, micromirror structures were fabricated and their deformations were experimentally measured. The experimental deformations were reduced by 87.1%. The calculated results agree well with the experimental results and demonstrate the effectiveness of the proposed method.

A Study on the Internal Structure of Heumgyeonggaknu

Heumgyeonggaknu is a water-hammering type automatic water clock which was made by Jang Yeong-Sil in 1438. The water clock that is located in Heumgyeonggaknu consists of Suho which is equipped with 2-stage overflow. Constant water wheel power is generated by supplying a fixed amount of water of Suho to Sususang, and this power is transferred to each floor at the same time. The 1st floor rotation wheel of Gasan consists of the operation structure which has the shape of umbrella ribs. The 2nd floor rotation wheel is made so that the 12 hour signal, Gyeong-Jeom signal, and Jujeon constitute a systematic configuration. The 3rd floor rotation wheel is made so that the signal and rotation of Ongnyeo and four gods can be accomplished. Based on the above conceptual design, this paper analyzed the internal signal generation and power transmission of Heumgyeonggaknu.

ITS phylogeny of Middle Asian geophilic Umbelliferae-Apioideae genera with comments on their morphology and utility of psbA-trnH sequences

Generic delimitation and relationships within the taxonomically controversial group of geophilic Umbelliferae from Middle Asia are problematic. Geophilic plants in arid regions have a short period of development during spring and early summer and survive unfavorable seasons due to the presence of tuber-like underground storage organs. To investigate the circumscription of recently recognized Middle Asian geophilic genera and their relationships, we conducted phylogenetic analyses using DNA sequence data from rapidly evolving nuclear (nrITS) and chloroplast (psbA-trnH intergenic spacer) regions as well as multivariate analyses of the morphological and ITS data. Our results show that Galagania and Mogoltavia are monophyletic, whereas Bunium, Hyalolaena and Oedibasis are polyphyletic. Elaeosticta, one of the larger genera of geophilic Middle Asian umbellifers, is rendered paraphyletic by the inclusion of the enigmatic Hyalolaena melanorrhiza. The genus Scaligeria, in which most species of Elaeosticta were initially described, is not grouped with these genera and has other affinities. Our analyses also show that the morphological characters used for the delimitation of genera within this group of Umbelliferae (such as life form, cotyledon number, presence/absence of petiolules of basal leaflets, shape of mericarp ribs, width of mericarp commissure, number of secretory ducts in mericarp furrows) are rather homoplastic. The psbA-trnH sequences were not informative enough to reveal relationships among the genera studied, although some interesting features in the spacer evolution were revealed (maximum reduction in length among Umbelliferae, homoplasious directed substitutions to restore secondary structure).

Genetic associations for gilt growth, compositional, and structural soundness traits with sow longevity and lifetime reproductive performance1

The objective of this study was to estimate genetic associations for gilt growth, compositional, and structural soundness with sow longevity and lifetime reproduction. Performance and pedigree information from 1,447 commercial females from 2 genetic lines were included in the data analyzed. Growth was expressed as days to 113.5 kg BW (DAYS) and compositional traits included loin muscle area (LMA), 10th rib backfat (BF10), and last rib backfat (LRF). Structural soundness traits included body structure traits [length (BL), depth (BD), width (BWD), rib shape (BRS), top line (BTL), and hip structure (BHS)], leg structure traits [front legs: legs turned (FLT), buck knees (FBK), pastern posture (FPP), foot size (FFS), and uneven toes (FUT); rear legs: legs turned (RLT), leg posture (RLP), pastern posture (RPP), foot size (RFS), and uneven toes (RUT)], and overall leg action (OLA). Lifetime (LT) and removal parity (RP) were considered as longevity traits whereas lifetime reproductive traits included lifetime total number born (LNB), lifetime number born alive (LBA), number born alive per lifetime day (LBA/LT), and percentage productive days from total herd days (PD%). Genetic parameters were estimated with linear animal models using the average information REML algorithm. Second, to account for censored longevity and lifetime reproduction records, genetic parameters were estimated using Markov Chain Monte Carlo and Gibbs sampling methods. Similar estimates were obtained across the analysis methods. Heritability estimates for growth and compositional traits ranged from 0.50 to 0.70 and for structural soundness traits from 0.07 to 0.31. Longevity and lifetime reproductive trait heritability estimates ranged from 0.14 to 0.17 when REML was used. Unfavorable genetic correlations were obtained for DAYS with LT, RP, LNB, LBA, and PD% and for LRF with PD%. However, LMA was favorably associated with LT, RP, and LNB. Moderate to high correlations were obtained for BL and BRS with all longevity and lifetime reproductive traits. Correlations of BWD with LT and RP were moderate. Associations for leg soundness traits with longevity and lifetime reproductive traits were mainly low and nonsignificant (P ≥ 0.10). However, RLP was moderately correlated with LBA/LT and PD%. Current results indicate that selection for fewer DAYS has an antagonistic effect on lifetime performance. Furthermore, great BL, flat BRS, narrow BWD, and upright RLP seem detrimental to sow longevity and lifetime reproduction.

장경간 강바닥판 케이블교량에 적용하기 위한 폴리우레탄 폴리머콘크리트의 공용특성 연구

PURPOSES: The purpose of this study is to evaluate physical properties, durability, fatigue resistance, and long-term performance of poly-urethane concrete (PU) which can be possible application of thin layer on long-span orthotropic steel bridge and to check structural stability of bridge structure. METHODS : Various tests of physical properties, such as flexural strength, tensile strength, bond strength and coefficient of thermal expansion tests were conducted for physical property evaluation using two types of poly urethane concrete which have different curing time. Freezing and thawing test, accelerated weathering test and chloride ion penetration test were performed to evaluate the effect of exposed to marine environment. Beam fatigue test and small scale accelerated pavement test were performed to assess the resistance of PU against fatigue damage and long-term performance. Structural analysis were conducted to figure out structural stability of bridge structure and thin bridge deck pavement system. RESULTS: The property tests results showed that similar results were observed overall however the flexural strength of PUa was higher than those of PUb. It was also found that PU materials showed durability at marine environment. Beam fatigue test results showed that the resistances of the PUa against fatigue damage were two times higher than those of the PUb. It was found form small scale accelerated pavement test to evaluate long-term performance that there is no distress observed after 800,000 load applications. Structural analysis to figure out structural stability of bridge structure and thin bridge deck pavement system indicated that bridge structures were needed to increase thickness of steel deck plate or to improve longitudinal rib shape. CONCLUSIONS: It has been known that the use of PU can be positively considered to thin layer on long-span orthotropic steel bridge in terms of properties considered marine environment, resistance of fatigue damage and long-term performance.

Genetic parameters for growth, body composition, and structural soundness traits in commercial gilts1

The objective of this study was to estimate genetic parameters for growth, body composition, and structural soundness traits in commercial gilt lines. The data included 1,449 gilts: 462 females from a grandparent maternal line and 987 from a parent maternal line. Growth was expressed as number of days to a constant 113.5 kg BW (DAYS) and compositional traits included loin muscle area (LMA), 10th rib backfat (BF10), and last rib backfat (LRF). Subjective structural soundness evaluation was completed using a 9-point scale and included: body length (BL), body depth (BD), body width (BWD), rib shape (BRS), top line (BTL), and hip structure (BHS); front legs: legs turned (FLT), buck knees (FBK), pastern posture (FPP), foot size (FFS), and uneven toes (FUT); rear legs: legs turned (RLT), leg posture (RLP), pastern posture (RPP), foot size (RFS), and uneven toes (RUT); and overall leg action (OLA). Genetic parameters were estimated with multivariate linear animal models, using the average information REML algorithm. Heritability estimates for growth and body composition traits ranged from 0.50 to 0.70, for body structure traits from 0.15 to 0.31, for leg structure traits from 0.07 to 0.31, and the estimate for OLA was 0.12. Several moderate to high genetic correlations were obtained among body structure traits, whereas correlations among leg structure traits were mainly low and nonsignificant. A strong correlation was found between FPP and OLA (P < 0.001); more upright FPP coincided with inferior OLA. Furthermore, FBK and FFS appeared to be favorably associated with OLA (0.05 < P < 0.10). Body structure trait correlations among each other and with leg soundness traits were primarily favorable. Correlations indicated that great BL and high BTL coincided with each other and deterioration of other structural soundness traits. Although genetic correlations obtained for DAYS and backfat measurements with structural soundness traits had an unfavorable trend, they were mainly low to moderate (i.e., simultaneous genetic improvement would be possible, including adversely associated traits). Due to greater heritabilities, faster genetic change could be expected for compositional and body structure traits than leg structure traits. Because of the genetic relationship among the trait groups, using information across traits when making selection decisions could result in genetic improvement among leg soundness traits.

J121041 薄板中のスリットやリブの最適位置問題の解法([J121-04]解析・設計の高度化・最適化(4))

Slits are often used for unstiffening or functionalizing thin plate structures. In contrast, ribs are used for stiffening them. This paper describes an optimization method for designing the shape and position of slits or ribs on a thin plate structure. The slit and rib are assumed to be movable in the tangential directions to the plate surface. As an application of this solution, the compliance minimization problem subject to a slit or rib length constraint is formulated as a distributed-parameter shape optimization problem, and the shape gradient function is derived using the material derivative method. The optimal shape and position is determined by the H1 gradient method for shell. The re-meshing is introduced to maintain the mesh regularity. Design examples show that the optimal shape and position of slits or ribs are obtained by this approach while maintaining the mesh regularity.