• International Journal of Quality Innovation
• /
• v.10 no.1
• /
• pp.89-105
• /
• 2009

This study aims to probe into the influence of new product design and new product development process management on development performance. The research finding demonstrates that product design reveals positive and significant influence on new product development performance. Through statistical analysis, this study finds that companies in Taiwan value new product design. When companies value it more, they tend to have better new product development performance. With regard to the relation between new product development process management and new product development performance, the empirical results demonstrate that companies would pay more attention on new product development process management. With regard to new product idea and assessment, concept design and development, product function test and mass production in the market, through statistical analysis, this study finds that companies that value process management of new product development tend to have better new product development performance. As to the influence of new product design and new product process management on new product development performance, statistical analysis result demonstrates that the integration between new product design valued by companies in Taiwan and development process management would lead to significantly positive influence on new product development performance of the companies.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.13 no.4
• /
• pp.99-105
• /
• 2014

The domestic airline industry undertakes the production of finished products by assembling existing self-described components via a design process which involves assembly and production steps, after which many of the finished products are exported. However, high reliability and stability must be guaranteed, because customers require high-precision components at the time of manufacturing. In the aircraft parts industry, the mass production of high-value-added parts is limited. Therefore, a small production scale depending on the part is used, as many types of conventional CNC lathe machines with X-axis and Z-axis as well as Z-axis and C-axis CNC milling are used. The parts also rely on high-pressure air to increase production. The most important factors are good stability during processing, as high-precision parts are required, as noted above. It was found that as the C-axis rotation speed increased, the diameter of the cutting tool decreased with a decrease in the surface roughness, while the workpiece rotation speed increased with an increase in the surface roughness.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.16 no.6
• /
• pp.117-124
• /
• 2017

In this study, we investigated the optimization of process conditions by using the Six Sigma process, design of experiment (DOE) method and response surface method (RSM) to resolve dimensional deviation and appearance problems arising from the shortened process time of the mobile phone rear cover. The analysis of the trivial many was performed by 2-sample T-test and cooling time, and mold temperature and packing pressure were selected as the vital fews affecting the overall width of the product. The optimal conditions of the process were then studied using the DOE and the RSM. We analyzed the improvement effects by applying the selected optimal conditions to the production process and the results showed that the difference between the mean value and target value of the overall width stood at 0.01 mm, an improvement of 88.89% compared to current process that fell within the range of standard dimension. The short-term process capability stood at $4.77{\sigma}$, which implied an excellent technology level despite a decrease by $0.22{\sigma}$ compared to the current process. The difference in process capability decreased by $2.44{\sigma}$ to $0.41{\sigma}$, showing a significant improvement in management capability. Ultimately, the process time of the product was shortened from 18.3 seconds in the current process to 13.65 seconds, resulting in a 34.07% improvement in production yield.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.19 no.1
• /
• pp.100-107
• /
• 2020

As demand for high value-added products with hard materials increases, the line center is used for producing high value-added products in many industries such as aerospace, automobile fields. The line center is a key device for smart factory automation that can improve the production efficiency and the productivity. Therefore, the development of a mill-turn line center is necessary to produce high value-added products with complex shapes flexibly. In the mill-turn process, a milling process and a turning process are combined. In particular, the turning process needs to increase the rigidity of the spindle. The purpose of this study is to analyze the thermal-structural stability through thermo-structural coupled analysis for a mill-turn spindle with a curvic coupling. The maximum temperature and thermal stability of the spindle were analyzed by thermal distribution. In addition, the thermal deformation and thermal-structural stability of the spindle were analyzed through thermo-structural coupled analysis.

• Journal of Forest and Environmental Science
• /
• v.31 no.1
• /
• pp.1-6
• /
• 2015

Microwave assisted biodiesel production from crude Pongamia pinnata oil using homogeneous base catalyst (KOH) was unsuccessful because of considerable soap formation. Therefore, a two step process of biodiesel production from high free fatty acid (FFA) oil was investigated. In first step, crude P. pinnata oil was acid catalyzed using $H_2SO_4$ and acid value of oil was reduced to less than 4 mg KOH/g. Effect of sulfuric acid concentration, alcohol-oil molar ratio and microwave irradiation time on acid value of oil was studied. Result suggested that 1.5% $H_2SO_4$ (w/w), 6:1 methanol oil molar ratio and 3 min microwave irradiation time was sufficient to reduce the acid value of oil from 12 and 22 mg KOH/g to 2.9 and 3.9 mg/KOH/g, respectively. Oil obtained after pretreatment was subsequently used for microwave assisted alkali catalyzed transesterification. A higher biodiesel yield (99.0%) was achieved by adopting two step processes. Microwave energy efficiency during alkali catalyzed transesterification was also investigated. The results suggested a significant energy saving because of reduced reaction time under microwave heating.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.40 no.1
• /
• pp.79-86
• /
• 2017

This research focused on deciding optimal manufacturing WIP (Work-In-Process) limit for a small production system. Reducing WIP leads to stable capacity, better manufacturing flow and decrease inventory. WIP is the one of the important issue, since it can affect manufacturing area, like productivity and line efficiency and bottlenecks in manufacturing process. Several approaches implemented in this research. First, two strategies applied to decide WIP limit. One is roulette wheel selection and the other one is elite strategy. Second, for each strategy, JIT (Just In Time), CONWIP (Constant WIP), Gated Max WIP System and CWIPL (Critical WIP Loops) system applied to find a best material flow mechanism. Therefore, pull control system is preferred to control production line efficiently. In the production line, the WIP limit has been decided based on mathematical models or expert's decision. However, due to the complexity of the process or increase of the variables, it is difficult to obtain optimal WIP limit. To obtain an optimal WIP limit, GA applied in each material control system. When evaluating the performance of the result, fitness function is used by reflecting WIP parameter. Elite strategy showed better performance than roulette wheel selection when evaluating fitness value. Elite strategy reach to the optimal WIP limit faster than roulette wheel selection and generation time is short. For this reason, this study proposes a fast and reliable method for determining the WIP level by applying genetic algorithm to pull system based production process. This research showed that this method could be applied to a more complex production system.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.10
• /
• pp.1656-1664
• /
• 2019

Isoprene has the potential to replace some petroleum-based chemicals and can be produced through biological systems using renewable carbon sources. Ralstonia eutropha can produce value-added compounds, including intracellular polyhydroxyalkanoate (PHA) through fatty acid and lipid metabolism. In the present study, we engineered strains of R. eutropha H16 and examined the strains for isoprene production. We optimized codons of all the genes involved in isoprene synthesis by the mevalonate pathway and manipulated the promoter regions using pLac and pJ5 elements. Our results showed that isoprene productivity was higher using the J5 promoter ($1.9{\pm}0.24{\mu}g/l$) than when using the lac promoter ($1.5{\pm}0.2{\mu}g/l$). Additionally, the use of three J5 promoters was more efficient ($3.8{\pm}0.18{\mu}g/l$) for isoprene production than a one-promoter system, and could be scaled up to a 5-L batch-cultivation from a T-flask culture. Although the isoprene yield obtained in our study was insufficient to meet industrial demands, our study, for the first time, shows that R. eutropha can be modified for efficient isoprene production and lays the foundation for further optimization of the fermentation process.

• The Research Journal of the Costume Culture
• /
• v.27 no.6
• /
• pp.654-665
• /
• 2019

The process of clothing production creates waste and scrap, which creates environmental, economic, and ethical issues. With this in mind the concept of ethical and sustainable fashion is discussed on many platforms as an important and timely topic. Many solutions have been presented on this subject. For the solution of this problem which has been increasing in the fashion and textile industry, the usage of sustainable materials and production methods is needed. There in a 'recyclable material cycle' should be adapted, instead of a 'traditional material cycle'. New methods and techniques should be developed with multi-disciplinary design approaches to produce creative and high value-added products in the name of fashion and sustainability. This is seen as one of the more effective solutions. This study aims to show that production scraps can be transformed into timely clothing designs with samples. The fabric scraps from different brands were turned into unique clothing designs with up to date trends by designer. In the practices completed while following the design process, collage and patchwork techniques were applied depending on the characteristics of the scrap fabric, artistic figures were hand-stitched onto the design. With this study, the scraps that get thrown into dumping grounds and damage the ecosystem can turn into ethical and economic benefits for the manufacturer. How to choose new high value-added products and create an awareness of social responsibility is also shown with examples in this study.

• Korean Journal of Organic Agriculture
• /
• v.25 no.4
• /
• pp.805-819
• /
• 2017

The study was carried out to develop a mathematical model for evaluating the effect of organic fertilizers in organic rice production systems. A function to simulate the nitrogen mineralization process in the paddy soil has been developed and integrated into ORYZA2000 crop growth model. Inorganic nitrogen in the soil was estimated by single exponential models, given temperature and C:N ratio of organic amendments. Data collected from the two-year field experiment were used to evaluate the performance of the model. The revised version of ORYZA2000 provided reasonable estimates of key variables for nitrogen dynamics and crop growth in the organic rice production systems. Coefficient of determination between the measured value and simulated value were 0.6613, 0.8938, and 0.8092, respectively for soil inorganic nitrogen, total dry matter production, and rice yield. This means that the model could be used to quantify nitrogen supplying capacity of organic fertilizers relative to chemical fertilizer. Nitrogen dynamics and rice growth simulated by the model would be useful information to make decision for organic fertilization in organic rice production systems.

• Journal of the Korean Society of Industry Convergence
• /
• v.12 no.2
• /
• pp.69-78
• /
• 2009

Dust in the fabric production sites is increased by the static electricity in air which is generated in the manufacturing process. The static electricity is shown in inverse proportion to humidity of the production sites. The optimum humidity rate for the filament in the production process has been established as 65~75%. Where as, average humidity rate of production site is estimated as 40%. Therefore, it is necessary to raise the humidity rate by 30% to maintain appropriate humidity to control generation of static electricity and dust in the production sites. In this study, a new air-jet water sprayer was developed and it can produce $10{\mu}m$ sprayed particles. When the air-jet water sprayer was operated on the production site dust generation rate was shown far below the environmental standard. It is assumed that when the air jet sprayers was applied to 1,000 fabric machines of 5 gloves making plants, its productivity and rates of operation will be improved by value of about 2.5 billion Won a year.