• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.24-27
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• 2001

Nowadays, increasing demand of the customized products has led to an increased usage of rapid prototyping in the product development. However, the acquisition price of a rapid prototyping equipment is still too high that not every body can afford to buy one. To offer a wide access to the users who need physical prototypes, a connection of the rapid prototyping equipment to the Internet is a viable step. It would allow a large group of customers all over the world to use the manufacturing capability of a service provider offering this kind of manufacturing service. To realize how such an e-manufacturing concept can look like, a LOM-type 3D printer developed at KIST has been used as test site and connected to the Internet. A possible user can log on to the server of the equipment and view his STL file and start the building operation from a remote place. To see whether the operation runs properly, a CCD camera is used to transmit the actual state of operation online. The result so far proves the feasibility of rapid prototyping on the Internet as well as an order-adaptive manufacturing system via web.

• 한국전자거래학회:학술대회논문집
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• 한국전자거래학회 2002년도 e-Biz World Conference
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• pp.107-131
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• 2002

최근 제조산업에 있어 다품종, 소량화하는 생산환경과 생산이라는 기능 이외의 판매, 기술 개발 등의 부분을 컴퓨터 네트워크로 결합하여 전반적인 기업 활동의 종합적인 효율화가 중요한 문제로 대두되고 있다. 이러한 요구에 의해 통합 생산정보시스템이 발전하였고 각종 산업제품의 치열한 국제경쟁에 따른 생산시스템 및 마케팅의 세계화는 이러한 변화에 대처하는 지능형 생산시스템(IMS : Intelligent Manufacturing System) 체계를 필요로 하게 되었다. 따라서, 본 연구에서는 이러한 IMS를 효율적으로 구축하기 위해 제조분야의 정보시스템에 대한 분석과 문제점 및 발전방안을 알아보고, 효율적인 제조 정보시스템 구축에 있어서 필수적인 정보화 전략계획의 체계적인 수립 방안으로 각 정보화 전략계획 수립 단계별 절차와 산출물 그리고 산출물의 통합관리에 대한 체계를 개발하였다. 또한, 정보화 전락계획의 효율적 적용을 위해 각 단계별 상세한 체계설계와 Template를 제시하여 IMS를 효율적으로 지원하는 정보화 전략계획 수립 방안을 제시하였다.

• 보존과학회지
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• 제38권4호
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• pp.301-313
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• 2022

We made a Korean white porcelain or Joseon Baekja jar and based on the raw materials used and reproductions of each stage, we aimed to compare and analyze the physicochemical changes of the raw materials such as clay at each manufacturing stage, as well as identify the characteristics and correlations. Although the basic main components of clay and glaze material are similar, their texture becomes denser in the process of bisque firing pottery (Chobeol-pyeon) and glaze firing pottery (Jaebeol-pyeon), and we confirmed that in addition to the tendency of increasing vitrification, low-temperature minerals such as mica and illite gradually disappeared, while high-temperature minerals such as cristobalite were newly created. This phenomenon has also been verified by the rapid decrease in absorption rate while the change in specific gravity was small. In addition, the color was greatly affected by the firing atmosphere, and the yellow-red chromaticity of the raw materials was higher during bisque firing but showed a rapidly decreasing characteristic during glaze firing. The value of magnetic susceptibility, which is related to iron (Fe) component, showed a tendency to decrease in glaze firing pottery. CT images were confirmed as a method that can indirectly estimate the change in the material properties of the object step-by-step for the entire object. In conclusion, the study of manufacturing stages of reproduction can provide basic data for scientific research on the estimation of porcelain and pottery making technology and changes in raw materials.

• Membrane and Water Treatment
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• 제1권1호
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• pp.13-37
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• 2010

The performance of an electrodialyzer for concentrating seawater is predicted by means of a computer simulation, which includes the following five steps; Step 1 mass transport; Step 2 current density distribution; Step 3 cell voltage; Step 4 NaCl concentration in a concentrated solution and energy consumption; Step 5 limiting current density. The program is developed on the basis of the following assumption; (1) Solution leakage and electric current leakage in an electrodialyzer are negligible. (2) Direct current electric resistance of a membrane includes the electric resistance of a boundary layer formed on the desalting surface of the membrane due to concentration polarization. (3) Frequency distribution of solution velocity ratio in desalting cells is equated by the normal distribution. (4) Current density i at x distant from the inlets of desalting cells is approximated by the quadratic equation. (5) Voltage difference between the electrodes at the entrance of desalting cells is equal to the value at the exits. (6) Limiting current density of an electrodialyzer is defined as average current density applied to an electrodialyzer when current density reaches the limit of an ion exchange membrane at the outlet of a desalting cell in which linear velocity and electrolyte concentration are the least. (7) Concentrated solutions are extracted from concentrating cells to the outside of the process. The validity of the computer simulation model is demonstrated by comparing the computed results with the performance of electrodialyzers operating in salt-manufacturing plants. The model makes it possible to discuss optimum specifications and operating conditions of a practical-scale electrodialyzer.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 춘계학술대회 논문집
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• pp.504-509
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• 2003

In this paper, a multi-step optimization using a G.A.(Genetic Algorithm) with variable penalty function is introduced to the structural design optimization of a high speed machining center. The design problem, in this case, is to find out the best cross-section shapes and dimensions of structural members which minimize the static compliance, the dynamic compliance, and the weight of the machine structure simultaneously. The first step is the cross-section shape optimization, in which only the section members are selected to survive whose cross-section area have above a critical value. The second step is a static design optimization, in which the static compliance and the weight of the machine structure are minimized under some dimensional constraints and deflection limits. The third step is a dynamic design optimization, where the dynamic compliance and the structure weight are minimized under the same constraints as those of the second step. The proposed design optimization method was successful applied to the machining center structural design optimization. As a result, static and dynamic compliances were reduced to 16% and 53% respectively from the initial design, while the weight of the structure are also reduced slightly.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.944-947
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• 2000

Sculptured surface machining plays a vital role in the process of bring new products to the market place. A great variety of products rely on this technology for the production of the dies and moulds used in manufacturing. And, the use of CNC machines and CAD/CAM system has become a vital parts of product development process. The propose of this study is to investigate the effect of cutting parameters on the machinability such as surface roughness and cusp generated in the machining of sculptured surface on a three-axis CNC machining center using the CAD/CAM system. Experimental result showed that: In step down cutting, as the inclined angle of surface became smaller, the cusp height appeared higher. On the other hand, in step over cutting, as the inclined angle of surface became larger, the cusp height appeared higher. In the point of precision machining, step over cutting was more effective. For the minimization of cusp height, step down cutting was effective in larger inclined surface, but step over cutting in smaller inclined surface.

• International Journal of Precision Engineering and Manufacturing
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• 제4권5호
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• pp.27-33
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• 2003

G-code, another name of ISO6983, has been a popular commanding language for operating machine tools. This G-code, however, limits the usage of today's fast evolving high-performance hardware. For intelligent machines, the communications between machine and CAD/CAM departments become important, but the loss of information during generating G-code makes the production department isolated. The new standard for operating machine tools, named STEP-NC is just about to be standardized as ISO14649. As this new standard stores CAD/CAM information as well as operation commands of CNC machines, and this characteristic makes this machine able to exchange information with other departments. In this research, the new CNC machine operated by STEP-NC was built and tested. Unlike other prototypes of STEP-NC milling machines, this system uses the STEP-NC file in XML file form as data input. This machine loads information from XML file and deals with XML file structure. It is possible for this machine to exchange information to other databases using XML. The STEP-NC milling machines in this research loads information from the XML file, makes tool paths for two5D features with information of STEP-NC, and machines automatically without making G-code. All software is programmed with Visual $C^{++}$, and the milling machine is built with table milling machine, step motors, and motion control board for PC that can be directly controlled by Visual $C^{++}$ commands. All software and hardware modules are independent from each other; it allows convenient substitution and expansion of the milling machine. Example 1 in ISO14649-11 having the full geometry and machining information and example 2 having only the geometry and tool information were used to test the automatic machining capability of this system.

• Journal of Electrochemical Science and Technology
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• 제8권3호
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• pp.215-221
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• 2017

The electroless plating process largely consists of substrate cleaning, seed formation (activator formation), and electroless plating. The most widely used activator in the seed formation step is Pd, and Sn ions are used to facilitate the formation of this Pd seed layer. This is problematic because the Sn ions interfere with the reduction of Cu ions during electroless plating; thus, the Sn ions must be removed by a hydrochloric acid cleaning process. This method is also expensive due to the use of Pd. In this study, Cu electroless plating was performed by forming a seed layer using a silver nanosol instead of Pd and Sn. The effects of the Ag nanosol concentration in the pretreatment solution and the pretreatment time on the thickness and surface morphology of the Cu layer were investigated. The degrees of adhesion to the substrate were similar for the electroless-plated Cu layers formed by conventional Pd activation and those formed by the Ag nanosol.

• 한국의사학회지
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• 제26권2호
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• pp.135-148
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• 2013

This study analyzed surface-chemical transitions in manufacturing process of traditional acupuncture as proposed method by Dongeuibogam. The manufacturing process of traditional acupuncture from a used iron for a long time was divided by primary medicinal herbs treatment, secondary medicinal herbs treatment and tertiary treatment using by dog meat. The traditional acupuncture research process was measured according to the characteristics and changes of the specimens at each processing step of the manufacturing process. The following devices were used to Surface analysis. Scanning electron microscopy (SEM), Energy Dispersive Spectrometer (EDS), X-ray diffraction analyzer (XRD). As a result, medicinal herbs removed impurities on the surface and raised the antibacterial effect in the manufacturing process of traditional acupuncture. Furthermore, the ingredients of medicinal herbs were coated on the surface of the iron. Dog meat influenced to prevent surface corrosion, reduce friction when the acupuncture was inserted. Although the process empirically obtained, a glimpse of the wisdom of our ancestors was revealed. These ancestral wisdom can be expected to apply today, when used in manufacturing process of a modern stainless steel acupuncture to compensate for the defective part.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.574-575
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• 2021

재제조(Re-manufacturing)는 제품의 수명이 다하여 폐기단계에 있는 사용 후 제품이나 부품을 회수하여 재처리 후 신제품 조립공정과 같은 재조립 과정을 거쳐 본래 가지고 있던 제품의 기능 및 성능을 회복하도록 하는 제조방법의 하나이다. 재재조 산업은 환경보호 측면 뿐만 아니라 경제적 측면 또한 중요하다. 산업전반의 성패는 제품에 대한 신뢰 및 가격 경쟁력에 달려있다. 제품 제조 공정에서 인건비를 줄이고 제품의 신뢰도를 향상시키기 위해 영상처리 시스템을 이용한다. 본 연구에서는 폐드럼을 재생하기 위해 전처리 단계인 재활용 여부 판단 단계 및 드럼을 재생한 후 출고직전 영상처리를 이용하여 사람의 육안으로 식별이 어려운 이물질 및 불량을 검출한다.