• Journal of the Korea institute for structural maintenance and inspection
• /
• v.16 no.3
• /
• pp.117-127
• /
• 2012

As increasing number of large-size earthquake around Korean peninsula, many interests have been focused to the earthquake strengthening of existing structures. Fiber reinforced plastic composite material is one of strengthening material widely used to increase seismic performance of structures. It should have high stiffness as well as large ductility to provide best strengthening result. Thus selection of stiffener and fiber in composite is of important. In this study, the optimal combination of fiber and stiffener is selected with variety of tensile tests. In order to investigate performance of chosen composite material, several finite element analyses are performed with proposed FRP composite material for existing RC columns. It is discussed that the seismic performance of strengthened columns through the load-displacement relationship. It is shown that the proposed composite material can increase the strength as well as ductility of exiting RC columns.

• Structural Engineering and Mechanics
• /
• v.86 no.4
• /
• pp.487-501
• /
• 2023

Nanoparticles have lower size and larger specific surface area, good stability and less toxic and side effects. In recent years, with the development of nanotechnology, its application range has become wider and wider, especially in the field of biomedicine, which has received more and more attention. Bone defect repair materials with high strength, high elasticity and high tissue affinity can be prepared by nanotechnology. The purpose of this paper was to study how to analyze and study the composite materials for sports bone injury based on multifunctional nanomaterials, and described the electrospinning method. In this paper, nano-sized zirconia (ZrO₂) filled micro-sized hydroxyapatite (HAP) composites were prepared according to the mechanical properties of bone substitute materials in the process of human rehabilitation. Through material tensile and compression experiments, the performance parameters of ZrO₂/HAP composites with different mass fraction ratios were analyzed, the influence of filling ZrO₂ particles on the mechanical properties of HAP matrix materials was clarified, and the effect of ZrO₂ mass fraction on the mechanical properties of matrix materials was analyzed. From the analysis of the compressive elastic modulus, when the mass fraction of ZrO₂ was 15%, the compressive elastic modulus of the material was 1222 MPa, and when 45% was 1672 MPa. From the analysis of compression ratio stiffness, when the mass fraction of ZrO₂ was 15%, the compression ratio stiffness was 658.07 MPa·cm³/g, and when it was 45%, the compression ratio stiffness is 943.51MPa·cm³/g. It can be seen that by increasing the mass fraction of ZrO₂, the stiffness of the composite material can be effectively increased, and the ability of the material to resist deformation would be increased. Typically, the more stressed the bone substitute material, the greater the stiffness of the compression ratio. Different mass fractions of ZrO₂/HAP filling materials can be selected to meet the mechanical performance requirements of sports bone injury, and it can also provide a reference for the selection of bone substitute materials for different patients.

• Economic and Environmental Geology
• /
• v.34 no.4
• /
• pp.417-422
• /
• 2001

Sutfactants may be used in remediation of subsoil and aquifer contaminated with hydrophobic compounds. The objectives of this study were to select potentially suitable sUlfactants that solubilize toluene present as a contaminant and to determine the effectiveness of toluene removal from Ottawa sand by the selected surfactants. Material used as the model soil was Ottawa sand and the organic used as model contaminant was toluene. Used experimental methods were separatory funnel experiment and shaker table agitation/centrifugation experiments. Based on the experimental results, the following conclusions were drawn; t) In the surfactant selection, six different surfactants were chosen based on surfactant types, toxicity, and water solubility. These six were focused into two on the basis of HLB and surface tension study, separatory funnel experiment, shaker table and centrifugation experiments. The two most suitable surfactants were Sandopan JA36 (an anionic surfactant), and Pluronic L44 (a non-ionic surfactant). 2) In the shaker table agitation and centrifugation experiments, the highest recovery of the toluene was 96% which was obtained with one surfactant wash plus two water rinses using an anionic surfactant (Sandopan JA36).

• Korean Journal of Logic
• /
• v.12 no.2
• /
• pp.31-58
• /
• 2009

This paper defends Stalnaker's theory of indicative conditionals. His theory consists of selection functions and pragmatic constraints. The selection function takes a certain possible world(W) and a proposition(A) to yield a possilble world that is similar to W and in which A is true. And the pragmatic constraints plays role to make selection functions apply just to indicative conditionals. According to Stalnaker, as indicative conditionals has strong truth-value, uncontested principle always holds but passage principle does not always hold. However, his theory can explain why passage principle sometimes holds by means of pragmatic constraints. Also, this paper argues that Stalnaker's theory is the most acceptable one among others, by replying to criticisms suggested by Adamsians and the problem raised by Gibbard and other criticisms.

• International Journal of Highway Engineering
• /
• v.4 no.1 s.11
• /
• pp.123-134
• /
• 2002

Special pavement test sections were selected to develop a distress prediction model on asphalt pavement of National Highway. Experimental design was conducted for the selection of LTPP sections on in-service pavement(new and overlaid pavement) using several variables affecting pavement performance. Preliminary sections that satisfied the design template were chosen from the national highway database, and final selection was fixed through field inspection. The number of monitoring section is 95 including 47 overlaid pavement. A pavement distress data such as crack and rutting were collected for two years. An interim pavement performance analysis was peformed to show feasibility of performance monitoring program. Data related pavement such as traffic, weather, material characteristic and crack etc. should be collected for next project years and distress prediction model will be developed through the statistical analysis.

• Journal of Korea Society of Industrial Information Systems
• /
• v.6 no.4
• /
• pp.1-5
• /
• 2001

This study presents an electronic catalogue based cutting parameter selection system using MS Access software. The proposed system has been designed to electronically select proper cutting conditions based on the stored data base. The existing approaches used in most small and medium sized companies are basically to use manufacturing engineer's experience or to find the recommended values from the manufacturing engineer handbook. These processes are often time consuming and inconsistent, especially when a new engineer is involved. Therefore, this study proposes a simple, yet quick and consistent electronic catalogue based cutting parameter selection method which uses MS Access in terms of programming and database implementation. Consequently, the proposed system could automatically generate the proper cutting conditions (feed, depth of cut, and cutting speed) as soon as the input data (proper information about the tool and work material) is given. Thanks to the simple structure and popularity of the MS Access, the engineer could be quickly accustomed to the system and easily modify/insert/delete the database if necessary.

• Fashion & Textile Research Journal
• /
• v.15 no.5
• /
• pp.694-703
• /
• 2013

A variable dress design can be an alternative to satisfy a consumer need for diverse expression and self-realization at a lower cost factor. In the area of wedding dress, the change in the trend of wedding culture (which tends to demand more units of wedding dress) makes the cost factor more important in the purchase selection. A variable design has a clear advantage for wedding dresses and the wedding industry. This is the first research on a variable design that focuses on wedding dresses. This research develops a variable wedding design which respects consumer preferences independent of a variable wedding dress design that presents a new shape of silhouette or the development ofa new wedding dress materials. A survey on the supply side was conducted to examine market preferences by first browsing the Naver portal site and then checking the websites of major wedding dress suppliers. A questionnaire survey was conducted with a sample of 348 brides-to-be that inquired on wedding dress selection factors and purchase patterns. The survey shows that consumers prefer mermaid and A-line silhouettes, silk material, white-ivory color, and tube top necklines. The result conforms to the types commonly found in the designs of suppliers. We apply a detachable design to a basic mermaid silhouette and implemented change for 7 kinds of styles -based on the result of the survey. We suggest a variable wedding dress design as a new means to solve the cost concern and the customer need for diverse expression. The research represents a new life style for wedding culture and facilitates the development of the wedding industry.

• Animal Bioscience
• /
• v.37 no.7
• /
• pp.1168-1176
• /
• 2024

Objective: As a charismatic species, cashmere goats have rich genetic resources. In the Inner Mongolia Autonomous Region, there are three cashmere goat varieties named and approved by the state. These goats are renowned for their high cashmere production and superior cashmere quality. Therefore, it is vitally important to protect their genetic resources as they will serve as breeding material for developing new varieties in the future. Methods: Three breeds including Inner Mongolia cashmere goats (IMCG), Hanshan White cashmere goats (HS), and Ujimqin white cashmere goats (WZMQ) were studied. IMCG were of three types: Aerbas (AEBS), Erlangshan (ELS), and Alashan (ALS). Nine DNA samples were collected for each population, and they were genomically re-sequenced to obtain high-depth data. The genetic diversity parameters of each population were estimated to determine selection intensity. Principal component analysis, phylogenetic tree construction and genetic differentiation parameter estimation were performed to determine genetic relationships among populations. Results: Samples from the 45 individuals from the five goat populations were sequenced, and 30,601,671 raw single nucleotide polymorphisms (SNPs) obtained. Then, variant calling was conducted using the reference genome, and 17,214,526 SNPs were retained after quality control. Individual sequencing depth of individuals ranged from 21.13× to 46.18×, with an average of 28.5×. In the AEBS, locus polymorphism (79.28) and expected heterozygosity (0.2554) proportions were the lowest, and the homologous consistency ratio (0.1021) and average inbreeding coefficient (0.1348) were the highest, indicating that this population had strong selection intensity. Conversely, ALS and WZMQ selection intensity was relatively low. Genetic distance between HS and the other four populations was relatively high, and genetic exchange existed among the other four populations. Conclusion: The Inner Mongolia cashmere goat (AEBS type) population has a relatively high selection intensity and a low genetic diversity. The IMCG (ALS type) and WZMQ populations had relatively low selection intensity and high genetic diversity. The genetic distance between HS and the other four populations was relatively high, with a moderate degree of differentiation. Overall, these genetic variations provide a solid foundation for resource identification of Inner Mongolia Autonomous Region cashmere goats in the future.

• Journal of Fashion Business
• /
• v.24 no.5
• /
• pp.125-139
• /
• 2020

The fashion industry that perceived the severity of environmental pollution, has sought various methods of sustainable fashion. However, most of the businesses paid attention to the development of materials using industrial waste, or vegan material. Thus, this study aims to present the methods for improvement in creativity for inversely developing the design from patterns and present new approaches by applying the contrarian development of proto to class under the limited condition of material concerning general design, selection of material, and production of sample. In the case of three student teams enrolled in the first semester of the second year, the fabric and used clothing donated by industry were used as material. The whole cut for cutting a single fabric in connected state, and Zero Wastes Design within a rectangular frame of fabric, upcycling of used clothes, and cutting out of Geometric Form are suggested. The team(A) produced a zero-wastes coat and whole-cut Pancho that could be variously represented. The team(B) produced two kinds of asymmetric dress by utilizing used check-patterned shirts through upcycling. The team(C) utilized the fabric in geometric forms such as rectangle, trapezoid, and atypical figure by drawing design within donated fabrics. The items were a dress, blouse, and skirt. Consequently, an opportunity for both academia and industry to present more concrete methods for sustainable fashion and deeply perceive the sustainable fashion is presented along with novel methods for creation by carrying out the composition of pattern and design at the same time.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.21 no.4
• /
• pp.16-22
• /
• 2013

In this study, we propose the method of optimally changing material of BIW for minimizing weight while satisfying vehicle requirements on static stiffness. First, we formulate a material selection optimization problem. Next, we establish the CAE procedure of evaluating static stiffness. Then, to enhance the efficiency of design work, we integrate and automate the established CAE procedure using a commercial process integration and design optimization (PIDO) tool, PIAnO. For effective optimization, we adopt the approach of metamodel based approximate optimization. As a sampling method, an orthogonal array (OA) is used for selecting sampling points. The response values are evaluated at the sampling points and then these response values are used to generate a metamodel of each response using the linear polynomial regression (PR) model. Using the linear PR model, optimization is carried out an evolutionary algorithm (EA) that can handle discrete design variables. Material optimization result reveals that the weight is reduced by 44.8% while satisfying all the design constraints.