• Transactions of Materials Processing
• /
• v.10 no.6
• /
• pp.500-508
• /
• 2001

The integration of Rapid prototyping (RP) and Rapid Tooling (RT) has the potential for rapid net shaping of thee-dimensional parts, which have a geometrical complexity. In this study, a new R)P process, (VLM-SP), was proposed to manufacture net shapes of three-dimensional prototypes and it was shown that VLM-SP is an effective and economic process through the comparison of building time, building cost and dimensional accuracy for the test parts with the commercial RP processes ; LOM and FDM. In addition, the metal parts, which are a spanner shape and a clover punch, were produced by the plaster casting as one of RT using the prototypes of VLM-SP.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.6
• /
• pp.160-165
• /
• 1999

In surface grinding, the conditions of the grinding wheel give a significant effect on the ground workpieces comparing with other metal removal provesses. In this paper, to assist the development, a non-contacting optical method by the laser beam is introduced. The in-process measurement of scattering intensities has been made during surface grinding processes and the surface textures of wheel working surfaces are captured. Also, in order to determine the dressing time monitoring method of a grinding wheel, a three-dimensional computer simulation of the grinding operation has been attempted based on the contact mechanism and the surface-shaping system between the grinding wheel and the workpiece. The optimal dressing time is determined by the amount of the grain wear and work surface roughness.

• Journal of the East Asian Society of Dietary Life
• /
• v.4 no.1
• /
• pp.19-29
• /
• 1994

In this paper a review of literature on Nuruk(yeast) between 1907 and 1945 was made, which showed that barley, rice bran, oat, rye, and other ingredients were originally used according to region and production quantity. Yeast can be classified into rough (Chokuk) and powder (Bunkuk) types depending on the degree of grinding. Yeast also had seasonal names, being called " Choonkuk", Hakuk", Jeolkuk", and "Dongkuk" in the spring, summer, autumn and wither respectively. The form of yeast in terms of quantity, size, and shape varied greatly by region, Production facilities were composed of plant structures to suit each process, enabling continuous output. The production process included shaping, placement in the fermenting chamber, piling by turns, risk-sifting and final output. Testing procudures were divided into visual inspection, physical testing, and chemical analyses.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.20 no.4
• /
• pp.76-92
• /
• 1993

This paper is to propose an interpretation method of urban landscapes in Korea, which are formed and transformed in the course of modernization. As the theoretical basis, an extensive study is done to define the concepts of urban landscape; townscape in the architectonic terms, urban landscape in the cultural-geographical terms, and urban landscape in the landscape ecology are those scrutinized. As for the interpretation method, the landscape process that encompasses the spatio-temporal transformation, the causes and effects of morphogenesis, the contents and forms of landscape change are studied. The emphasis is placed on the reasons and process of the cultural change from the original landscapes toward the contemporary landscapes in the rapidly urbanizing area. With these basic concepts and interpretation method, an on-site case study of 'Inchon' that has been changed drastically since the late 19th century is done, of which results will be reported in the following article(II).

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09a
• /
• pp.225-226
• /
• 2006

In this present investigation, Metal Injection Moulding (MIM) of M2 High Speed Steel (HSS) parts using a wax-High Density Polyethylene (HDPE) binder is shown. The elimination of organic binder was carried out by thermal debinding under inert atmosphere. In order to keep carbon in the sample that could improve the sintering process, incomplete debinding was performed between 450 and $600^{\circ}C$. The specimens were sintered at temperatures between 1210 and $1280^{\circ}C$ in high vacuum atmosphere, obtaining the 98% of the theoretical density. In the samples with higher residual carbon content, the sintering window was extended up to 20 degrees and the optimum temperature was lower.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2005.05a
• /
• pp.270-274
• /
• 2005

The capability of net shaping for complex 3-D geometry, powder injection molding(PIM) is widely used for parts in the field of automotives, electronics and medical industry. Powder injection mold design for dental scaler tip, a component of medical appliance, was presented. In comparison with conventional machining process, powder injection molding has many advantages, specially in price and dimensional stability, for molding dental scaler tip. Product design and mold design for dental scaler tip was presented. Short shot experiment with scaler tip PIM mold and several defect (flash etc.) during injection molding process was discussed.

• Archives of Craniofacial Surgery
• /
• v.23 no.5
• /
• pp.193-204
• /
• 2022

Tongue reconstruction remains a major aspect of head and neck reconstructive procedures. Surgeons planning tongue reconstruction should consider several factors to optimize the overall outcomes. Specifically, various technical aspects related to tongue reconstruction have been found to affect the outcomes. Multidisciplinary teams dedicated to oncologic, reconstructive, and rehabilitative approaches play an essential role in the reconstructive process. Moreover, operative planning addressing certain patient-related and defect-related factors is crucial for optimizing functional speech and swallowing, as well as quality of life outcomes. Furthermore, tongue reconstruction is a delicate process, in which overall functional outcomes result from proper flap selection and shaping, recipient vessel preparation and anastomosis, surgical approaches to flap insetting, and postoperative management. The second part of this review summarizes these factors in relation to tongue reconstruction.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.1
• /
• pp.107-114
• /
• 2017

A turbocharger is an engine supercharger that is driven by exhaust gas. It improves the output and fuel efficiency by increasing the charging efficiency of the mixture gas, which is achieved by changing the rotatory power of the turbine connected to the exhaust passage. It is important to control the supercharging for this purpose. A nozzle slide joint is one of the core parts. Austenitic stainless steel is currently used as the material for this part, and its excellent mechanical properties include high heat resistance and corrosion resistance. However, because of its poor machinability, there are many difficulties in producing products with complicated shapes. Machining is used in the production of nozzle slide joints for high dimensional accuracy after metal powder injection molding. As design variables in this study, we investigated the sintering temperature, product stress, deformation rate, radius of curvature of the punch, and angle of the chamfer punch, which are related to the strain and shapes. The goal is to suggest a forming process using Nitronic 60 that does not require machining to manufacture a nozzle slide joint for a turbocharger. Accordingly, we determined the best process environment using finite-element analysis, the signal-noise ratio, and the Taguchi method for experiment design. The relative density and hydrostatic pressure of the final product were in accordance with the results of the finite element analysis. Therefore, we conclude that the Taguchi method can be applied to the design process of metal powder injection molding.

• Journal of Korean Philosophical Society
• /
• v.126
• /
• pp.79-108
• /
• 2013

Is the development of linguistic competence due to the learning process or the maturational process? According to Piaget, its development is a genuine learning process involving authentic constructions with gradual disclosure of new possibilities. But According to Chomsky, the acquisition of linguistic competence is due to a genetically conditioned maturational process. So it merely involves the actualization of a set of possibilities existing from the beginning Consequently, Piaget supposes that interaction with the environment plays a shaping role, while Chomsky allows it to have a mere triggering role. In broad respective, Chomsky supposes the rationalism that knowledge is largely inborn, while Piaget in the constructivist position which strives to find a middle course between radical rationalism and radical empiricism. In the one hand, an ultra-rationalistic concept such as 'fixed nucleus' supposed by Chomsky is, in my eye, nor plausible. In the other hand, if Piagetian constructivism is to be sustained, it must be sustained independently of its dubious biological fundament, and merely as a developmental psychological theory. In one word, we need to synthesize Piagetian cognitive approach and Chomskian syntactical, in order to explain exactly the source of human linguistic competence.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.16 no.4
• /
• pp.53-61
• /
• 2017

Turbocharger is a device for increasing the power of a vehicle engine. The control plate is the main component for fixing the vane of the turbocharger. Now, the control plate is made of austenite steel cutting after the casting process. It has excellent corrosion, heat resistance and mechanical characteristics of material. However, present the process is made by cutting after casting. when cutting is processed after casting, so materials, processing time, and processing energy are lost. Therefore, this study proposes a process to powder compact use of stainless steel Deklak2 and to minimize amount of cutting through net shape process. The mechanical properties of Deklak2 were verified by tensile test, hardness test and relative density measurement, and the governed equation was defined. Also, the curvature radius 1, 2 and the density, affects the shape, were selected as the design parameters, and the best process conditions was proposed through the Taguchi method and the evaluation of SN ratio. And then prototype molds were fabricated and compared with the results of the finite element analysis for the verification, and it was found that the tendency of relative density and dimension was coincided. Therefore, it was found that the amount of cutting can be minimized by only the net shape process after the sintering process and it can be applied to mass production.