• Corrosion Science and Technology
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• 제16권3호
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• pp.100-108
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• 2017

In this investigation corrosion behavior of newly developed high-pressure die cast Al-Ni (N15) and Al-Ni-Ca (NX1503) alloys was studied in 3.5% NaCl solution. The electrochemical corrosion behavior was evaluated using open circuit potential (OCP) measurement, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) techniques. Potentiodynamic polarization results validated that NX1503 alloy exhibited lower corrosion current density ($i_{corr}$) value ($5.969{\mu}A/cm^2$) compared to N15 ($7.387{\mu}A/cm^2$). EIS-Bode plots revealed a higher impedance (${\mid}Z{\mid}$) value and maximum phase angle value for NX1503 than N15 alloy. Equivalent circuit curve fitting analysis revealed that surface layer ($R_1$) and charge transfer resistance ($R_{ct}$) values of NX1503 alloy was higher compared to N15 alloy. Immersion corrosion studies were also conducted for alloys using fishing line specimen arrangement to simultaneously measure corrosion rates from weight loss ($P_W$) and hydrogen volume ($P_H$) after 72 hours and NX1503 alloy had lower corrosion rate compared to N15 alloy. The addition of Ca to N15 alloy significantly reduced the Al3Ni intermetallic phase and further grain refinement may be attributed for reduction in the corrosion rate.

• Steel and Composite Structures
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• 제33권6호
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• pp.823-836
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• 2019

Spiral welded tubes (SWTs) are fabricated by helically bending a steel plate and welding the resulting abutting edges. The cost-effectiveness of concrete-filled steel tube (CFST) columns can be enhanced by utilising such SWTs rather than the more conventional longitudinal seam welded tubes. Even though the steel-concrete interface bond strength of such concrete-filled spiral-welded steel tubes (CF-SWSTs) is an important consideration in relation to ensuring composite behaviour of such elements, especially at connections, it has not been investigated in detail to date. CF-SWSTs warrant separate consideration of their bond behaviour to CFSTs of other tube types due to the distinct weld seam geometry and fabrication induced surface imperfection patterns of SWTs. To address this research gap, axial push-out tests on forty CF-SWSTs were carried out where the effects of tube material, outside diameter (D), outside diameter to wall thickness (D/t), length of the steel-concrete interface (L) and concrete strength grade (f'_c) were investigated. D, D/t and L/D values in the range 102-305 mm, 51-152.5 and 1.8-5.9 were considered while two nominal concrete grades, 20 MPa and 50 MPa, were used for the tests. The test results showed that the push-out bond strengths of CF-SWSTs of both mild-steel and stainless-steel were either similar to or greater than those of comparable CFSTs of other tube types. The bond strengths obtained experimentally for the tested CF-SWSTs, irrespective of the tube material type, were found to be well predicted by the guidelines contained in AISC-360.

• 한국정밀공학회지
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• 제31권6호
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• pp.513-519
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• 2014

For depth machining in die and mold, Electrical Discharge Machining (EDM) is used generally. To make deep hole and deep shape efficiently, cemented carbide endmill for depth machining is necessary. For this purpose, cemented carbide endmill was designed using design of experiment (DOE). To improve cutting performance, endmill was coated with multilayer surface treatment, TiAlCrSiN and TiAlCrN, for higher wear resistance. In order to evaluate the endmill, Transverse Rupture Strength (TRS) test was tried for investigating the relationship between surface treatment and strength in endmill body. Scratch test was also used for measuring adhesion force of each surface treatment. To evaluate hardness of surface treatment, Atomic Force Microscope (AFM) analysis was carried out. Wear test was executed for characteristics of each surface treatment in high temperature. Consequently, TiAlCrSiN was superior to the TiAlCrN coating in case of high temperature environment such as cutting.

• 한국전기전자재료학회논문지
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• 제25권10호
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• pp.773-778
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• 2012

A road energy harvester was designed and fabricated to convert mechanical energy from the vehicle load to electrical energy. The road energy harvester is composed of 16 piezoelectric cantilevers. We fabricated prototypes using a vehicle load transfer mechanism. Applying a vehicle load transfer mechanism rather than directly installing energy harvesters under roads decreases the area of road construction and allows more energy harvesters to be installed on the side of the road. The power generation amount with respect to the vehicular velocity change was assessed by installing the vehicle load transfer mechanism form and underground form. The energy harvester installed in the underground form generated power of 4.52 mJ at the vehicular velocity of 50 km/h. Also, power generation of the energy harvester installed in the vehicle load transfer mechanism form was 48.65 mJ at the vehicular velocity of 50 km/h.

• Journal of Electrochemical Science and Technology
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• 제7권2호
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• pp.115-131
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• 2016

Though battery chemistry and technology had been developed for over a hundred years back, increase in demand for storage energy, in the computer accessories, cell phones, automobile industries for future battery car and uninterrupted power supply, has made, the development of existing and new battery, as an emerging areas of research. With innovation of high energetic inexpensive Nano structure materials, a more energy efficient battery with lower cost can be competitive with the present primary and rechargeable batteries. Materials electrochemistry of electrode materials, their synthesis and testing have been explained in the present paper to find new high efficient battery materials. The paper discusses fundamental of electrochemistry in finding true cell potential, overvoltages, current, specific energy of various combinations of anode-cathode system. It also describes of finding the performance of new electrode materials by various experiments viz. i. Cyclic Voltammetry ii. Chronoamperometry iii. Potentiodynamic Polarization iv. Electrochemical Impedance Spectroscopy (EIS). Research works of different battery materials scientists are discussed for the development of existing battery materials and new nano materials for high energetic electrodes. Problems and prospects of a few promising future batteries are explained.

• 지식경영연구
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• 제14권5호
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• pp.1-14
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• 2013

This paper is aimed at investigating the factors to grow the new technology based firm(NTBF), K-MAC. NTBFs need an environment in which novelty is encouraged, employees find work meaningful and controllable, learning is incorporated into work, ideas and process improvements are implemented and a balanced focus of the internal and external to the company is fostered. With collaboration between industry and academia, Lynda Aiman-Smith made an instrument of VIQ(Value Innovation Quotient), which is consist of 9 factors, 33 items. VIQ Results can help the company to develop a better understanding of the organization's culture, and its formal subgroups. That is to identify subcultures in the organization, to diagnose potential problems or inhibitors of innovation, to identify organizational strengths for innovation and set a quantitative baseline. Using the VIQ,K-MAC analysed the subculture of innovation potential capability. K-MAC organized the COP(community of practice) with the young employees' participation and try to solve the real problem in the working place. This paper explained the diverse growing trajectory through the TPM concept and suggest for the future strategy.

• 기술혁신연구
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• 제14권2호
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• pp.93-116
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• 2006

The purpose of this study is to contribute reference material that provides insight into innovative process management that increases R&D output in commercializing new products. A model of a process from research to commercialization with the cumulative profit and loss curve is put forward and hypotheses related to success and failure are developed at the stages up to product launch. Seventeen large projects that have resulted in successful product launches have been examined from the initial research stage to commercialization. Prefect duration, standardized cumulative R&D expenditures and research resource concentration are analyzed in terms of statistical method and patterns in cumulative profit and loss curves after product sales, as well as the reasons for and other aspects of success/failure are investigated and analyzed. Consequently, valuable information on future management tasks has been obtained such as: (1) project duration differs depending on market sectors, product types and presence/absence of materials research (2) cumulative profit and loss curves can be categorized into four patterns (3) reasons for failure can be divided into technological and market problem categories and (4) these factors have an impact on product sales.

• World Technopolis Review
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• 제4권3호
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• pp.132-143
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• 2015

In the 21st Century, scientific discovery and technological development are fueled by unprecedented changes in knowledge, societal needs and wants, engineering designs, materials, and instrumentation. Such rapid global changes pose major opportunities and challenges for the innovation ecosystem-especially in developing countries. In particular, our models for human resource development and engagement must evolve so as to better prepare leaders in higher education institutions, research institutes, science cities and science parks, businesses and industries, and governments. Universities throughout the world must play a greater role in both the research and practice of human resource development and engagement for the knowledge-based and creative economies. This paper explores the current and potential talent development and talent engagement dimensions of universities in economic development, and research and practice in education and policy-with implications of such dimensions for science cities/science parks. The paper highlights the importance of a greater role for universities, in collaborating with business/industry and governments, in examining new economics-sensitive and values-sensitive models for education and human resource development so as to better understand and support innovation in global contexts.

• 현장농수산연구지
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• 제25권4호
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• pp.67-77
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• 2024

This study analyzed the profitability and diagnosed business performance of fruit and vegetable (cherry tomatoes, tomatoes, strawberries, cucumbers) businesses targeting young farmers participating in the youth business incubation center of A Smart Farm Innovation Valley. The purpose of this is to provide basic data for decision-making by prospective young entrepreneurs. As a result of the analysis, Smart Farm Innovation Valley had the advantage of having a fixed rental fee. As a result, it was analyzed that various costs such as depreciation of large farm equipment, depreciation of farming facilities, repair and maintenance costs, land rent, floating capital service cost, fixed capital service cost, and land capital service cost are being reduced. However, excessive input of labor, water, electricity, other materials, and fertilizer costs was being made. Guidance to reduce these costs is expected to make a significant contribution to expanding the influx of young farmers.

• 한국분말재료학회지
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• 제23권2호
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• pp.149-169
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• 2016

Additive manufacturing (AM) is defined as the manufacture of three-dimensional tangible products by additively consolidating two-dimensional patterns layer by layer. In this review, we introduce four fundamental conceptual pillars that support AM technology: the bottom-up manufacturing factor, computer-aided manufacturing factor, distributed manufacturing factor, and eliminated manufacturing factor. All the conceptual factors work together; however, business strategy and technology optimization will vary according to the main factor that we emphasize. In parallel to the manufacturing paradigm shift toward mass personalization, manufacturing industrial ecology evolves to achieve competitiveness in economics of scope. AM technology is indeed a potent candidate manufacturing technology for satisfying volatile and customized markets. From the viewpoint of the innovation technology adoption cycle, various pros and cons of AM technology themselves prove that it is an innovative technology, in particular a disruptive innovation in manufacturing technology, as powder technology was when ingot metallurgy was dominant. Chasms related to the AM technology adoption cycle and efforts to cross the chasms are considered.