• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1993.11a
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• pp.4-4
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• 1993

Ferrous powder metallurgy in Japan has developed in the last four decades, where every decade is featured by certain breakthroughs in materials. The progress in PM materials is closely related to newly developed powders. Low alloy steel powders for high strength PM components are grouped into three types: Ni and/or Mo containing completely alloyed powders, Ni containing partially alloyed powders, and Cr containing completely alloyed powders. Every type has its special characteristics. The tensile strength of PM materials is improved up to 2 GPa. The hardness is also increased to exceed 500 HV with normal hardening methods, and 700 HV with novel surface treatment techniques. The present maximum of fatigue strength is 550 MPa, and that of impact energy is 100 J. Novel PM materials with improved properties are applied to a variety of automobile and other components: power steering pumps, rocker anns, valve guides and inserts, bearings, torque sensors, etc. The future outlook for the ferrous PM is Quite positive, and the industry is expected to show renewed growth by applying many types of alloy steel powders and new ferrous PM materials.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.03a
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• pp.69-90
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• 1996

In the chemical industry, in the pharmaceutical industry, and in a number of other industries separation processes are necessary to separate and purify products and raw materials [1,2]. Separation processes are also widely used in other applications such as in recycling valuable materials from waste streams. Unit operations for separation processes can be classified in phase separation techniques and component separation techniques based on the nature of the feed mixtures to be separated. The former techniques are used for the separation of heterogeneous mixtures, in which the feed is already present in two or more separated phases on a micro-scale. The latter are suitable for the separation of homogeneous mixtures such as gaseous mixtures and mixtures of completely miscible liquids. tn these cases the separation into individual components is generally achieved by utilizing the differences in physico-chemical properties of components, and is much more difficult compared to phase separation techniques. Separation processes such as distillation, evaporation, liquid-liquid extraction, and crystallization belong to this class.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.764-767
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• 2005

In the construction industry, materials management is one of the most important components in construction engineering life cycle. Materials management optimization is one of the research subjects in the field of construction management. In the materials management system of a construction project, the suitability of selecting procurement planning strategy will influence the result of project completion. This study conducts literature review at first and also refers the related issue in other industry's application. Associated with the characteristics of construction project in civil engineering and the concept of object oriented design applied in the materials management, this research is aimed to establish a construction materials requirement preliminary system.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.9
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• pp.33-39
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• 2020

Self-piercing rivets are often used in the automotive industry, among other industries, as mechanical components to join multiple materials such as aluminum alloys. Self-piercing rivets have a strong sealing property, although there is considerable scope for their performance improvement. In this study, to enhance the performance of self-piercing rivets, the hybrid self-piercing riveting (SPR) technique, using the existing SPR and structural adhesive, was proposed. Moreover, heterogeneous material specimens subjected to the hybrid SPR technique were manufactured and tested. The joint strength of the test pieces of different materials was evaluated through finite element analyses.

• Management & Information Systems Review
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• v.31 no.1
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• pp.273-292
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• 2012

This paper attempts to analyze the efficiency of Korean Materials and Components Industry. 48 sample companies are extracted and efficiency analysis for them are accomplished by using DEA model. We use both CCR-I model and BCC-I model and classify the 48 companies into two groups; efficient and inefficient companies. We find the reference set which inefficient companies should benchmark in order to achieve efficiency and present the improving values for input and output variables. We analyze whether the inefficiencies come from scale or inefficient operation by measuring the scale efficiency. Finally the ranking among the efficient companies is derived through the super-efficiency analysis.

• Communications for Statistical Applications and Methods
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• v.15 no.6
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• pp.883-897
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• 2008

This paper provides correct informations inflecting the present situation using the sample design in population that the National Statistical Office puts in operation of the mining and manufacturing industry statistical survey in 2006. This paper proposes new sampling design which is able to grasp business fluctuations and provide basic data for the rearing policy and management of the material industry and components industry. These sample design are the modified cut-off method and multivariate Neyman allocation using principal components and sampling method is the probability proportional systematic sampling.

• Journal of the Korean Ceramic Society
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• v.49 no.6
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• pp.581-585
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• 2012

Machinability is important in engineering applications, especially in the current micro-electronics industry. Most ceramic components have complex shapes and hence require machining generally with diamond tools, which incurs a high production cost. Recently, h-BN-containing machinable ceramics have been developed, but these materials are very expensive due to the high raw materials and production costs. Therefore, the development of low-cost machinable ceramics is necessary. In this study, inexpensive $Al_2TiO_5$ was studied as a replacement for h-BN. $Al_2O_3$, $TiO_2$ and partially stabilized $ZrO_2$(PSZ) powders were mixed with various mole ratios and were sintered at $1500^{\circ}C$ for 1 h. The density, hardness and strength were then measured. The phase analysis and microstructures were observed by XRD and SEM, respectively. The machinability of each specimen was tested by micro-hole machining. The results of this research showed that the produced composites could be used as low-cost machinable ceramics.

• Journal of the Microelectronics and Packaging Society
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• v.18 no.2
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• pp.1-9
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• 2011

Rare metals, called as vitamins of industry, are defined as the elements which are very few in the earth and are difficult to extract from ores. The requirements for total amounts of rare metals have increased as the global economics grows and the function of electronic components varies considerably. The rare metals have been maldistributed to America, CIS(Commonwealth of Independent States), China, Australia, Canada as about 80% of total natural resources, which also lead to unequal materials flow or distribution. Therefore, it was needed to investigate the feature of rare metals in terms of industry as well as technology. We could identify the industrial issues associated with the supply of critical rare elements in electronic components.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.06a
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• pp.68-75
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• 2000

The development of flexible automation in the manufacturing industry is concerned with production activities performed by unmanned machining system. A major topic relevant to metal-cutting operations is monitoring tool wear, which affects process efficiency and product quality, and implementing automatic tool replacements. In this paper, the measurement of the cutting force components has been found to provide a method for an in-process detection of tool wear. Cutting force components are divided into static and dynamic components in this paper, and the static components of cutting force have been used to detect flank wear. To eliminate the influence of variations in cutting conditions, tools, and workpiece materials, the force modeling is performed for various cutting conditions. The normalized force disparities are defined in this paper, and the relationships between normalized disparity and flank wear are established. Finally, Artificial neural network is used to learn these relationships and detect tool wear. According to the proposed method, the static force components could provide the effective means to detect flank wear for varying cutting conditions in turning operation.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.5
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• pp.15-22
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• 2015

The crop production technologies keep in improving and the cultivation becomes more standardization owing to the significant developments of various agricultural materials. The artificial soil and base system for root could be one of the major technologies for the modern cultivation especially for controlled horticulture. Although the perlite, cocopeat, and peat moss are the major components of the artificial soil and are broadly used for various application, there is a great need for the new alternative materials for overcoming the low nutrition and the possible shortage of raw materials. In this study, the application of oil palm EFB fiber as an alternative materials for artificial soil especially for the seeding pad components was evaluated. The changes in the structural properties and the functional properties such as moisture holding properties were compared by laboratory produced seeding pads with different mixture of oil palm EFB fiber. The addition of fibrillated EFB fiber resulted in the significant increase in durability of the seeding pad, which showed the possible application of EFB fiber to the seeding pad instead of the wood fiber (UBKP). The moisture holding properties and the germination condition characteristics of the EFB fiber showed the slight less than those of the cocopeat, which require more sophisticated study for improving the functional properties of seeding pad made of the EFB fiber.