• Journal of the Microelectronics and Packaging Society
• /
• v.8 no.3
• /
• pp.69-75
• /
• 2001

Photoimageable thick film technology is a new technology in that the lithography process such as exposure and development is applied to the conventional thick film process. Line resolution of 25 $\mu\textrm{m}$ width and 25 $\mu\textrm{m}$ space could be obtained by laminating green sheet, printing photoimageable Ag paste, exposing the test patterns, developing, and co-firing. In case of using the alumina substrate, 20 $\mu\textrm{m}$ fine line could be also obtained by similar process. Test results showed that exposing power density and developing time were the most important processing parameters for the fine line formation. Microstrip and series gap resonators with well-defined line morphology and good transmission characteristics in high frequency were formed by this new technology, and thereby dielectric constant and loss of test substrate were calculated.

• The Transactions of the Korea Information Processing Society
• /
• v.4 no.7
• /
• pp.1881-1892
• /
• 1997

This paper proposes the method for recognition of printed chinese characters by probabilistic VQ networks and multi-stage recognizer has hierarchical structure. We use modular neural networks, because it is difficult to construct a large-scale neural network. Problems in this procedure are replaced by probabilistic neural network model. And, Confused Characters which have significant ratio of miss-classification are reclassified using the entropy theory. The experimental object consists of 4,619 chinese characters within the KSC5601 code except the same shape but different code. We have 99.33% recognition rate to the training data, and 92.83% to the test data. And, the recognition speed of system is 4-5 characters per second. Then, these results demonstrate the usefulness of our work.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.4
• /
• pp.810-814
• /
• 2007

It is now possible for the general public to publish their own publications without difficulties because of versatile Internet environments and cost-effective printing machines. However, special software design tools are still required in order to design name cards, leaflets, yellow books and free newspaper. In this paper, we present a computerized typesetting model which automates all procedures of generating business cards the most representative commercial design example. All processes in our model are performed over the Internet from application to generation. Based on our model, we also introduce a web-based computerized typesetting system which collaborates with the Adobe InDesign CS2 and generates image files in real time for user requests. Such a system is linked with an automatic payment system so that a PDF file, a target output, is generated after a user confirms his/her order.

• Journal of Hydrogen and New Energy
• /
• v.32 no.5
• /
• pp.347-355
• /
• 2021

This paper is a study on the thermal design of printed circuit heat exchanger (PCHE) to supply cryogenic high pressure liquid hydrogen stored from hydrogen liquefaction process by using computational fluid dynamics (CFD). This PCHE should be thermally designed to raise the temperature of cryogenic liquid hydrogen to a desired temperature and also to be anti-icing to avoid any local freezing in hot channel. This research presents the effect of inlet velocity and inlet temperature of hydrogen, and the effect of flow configurations of co/counter-flow on thermal design of PCHE heat exchanger based on various CFD simulation analysis.

• Resources Recycling
• /
• v.23 no.6
• /
• pp.30-39
• /
• 2014

The trajectories of PCB(Printed Circuit Board) particles in the corona discharge electrostatic separation was simulated. The PCB particles are prepared by crushing bare board, which disassembled from electronic components, consist mostly of copper and FR-4(Flame Retardant Level-4) Firstly, a model was established for calculating of detachment points of PCB particles from the rotating electrode in separator. The model of detachment points was derived from equilibrium of force such as gravity force, centrifugal force, electrostatic force. The trajectories of particles after detachment was calculated by acceleration derived from time-integrating method of motion equation. In this simulation, particle size, supplied voltage, rotation speed of rotating roll electrode and angle of induction electrode were adopted as variables. While the trajectories of FR-4 particles were affected by all variables, rotation speed of rotating roll electrode was dominant variables affecting trajectories of copper particles.

• The KIPS Transactions:PartB
• /
• v.10B no.7
• /
• pp.777-784
• /
• 2003

In this Paper. we propose a recognition method of machine printed characters based on the combination of recognition units using multiple neural networks. In our recognition method, the input character is classified into one of 7 character types among which the first 6 types are for Hangul character and the last type is for non-Hangul characters. Hangul characters are recognized by several MLP (multilayer perceptron) neural networks through two stages. In the first stage, we divide Hangul character image into two or three recognition units (HRU : Hangul recognition unit) according to the combination fashion of graphemes. Each recognition unit composed of one or two graphemes is recognized by an MLP neural network with an input feature vector of pixel direction angles. In the second stage, the recognition aspect features of the HRU MLP recognizers in the first stage are extracted and forwarded to a subsequent MLP by which final recognition result is obtained. For the recognition of non-Hangul characters, a single MLP is employed. The recognition experiments had been performed on the character image database collected from 50,000 real letter envelope images. The experimental results have demonstrated the superiority of the proposed method.

• The KSFM Journal of Fluid Machinery
• /
• v.17 no.6
• /
• pp.77-83
• /
• 2014

The vessel of integral reactor contains its major primary components such as the fuel and core, pumps, steam generators, and a pressurizer, so its size is proportional to the required space for the installation of each component. The steam generators take up the largest volume of internal space of reactor vessel and their volumes is substantial for the overall size of reactor vessel. Reduction of installation space for steam generators can lead to much smaller reactor vessel with resultant decrease of overall cost for the components and related facilities. A printed circuit heat exchanger is one of the compact types of heat exchangers available as an alternative to conventional shell and tube heat exchangers. Its name is derived from the procedure used to manufacture the flat metal plates that form the core of the heat exchanger, which is done by chemical milling. These plates are then stacked and diffusion bonded, converting the plates into a solid metal block containing precisely engineered fluid flow passages. The overall heat transfer area and pressure drops are evaluated for the steam generator based on the concept of the printed circuit heat exchanger in this study. As the printed circuit heat exchanger is known to have much larger heat transfer area density per unit volume, we can expect significantly reduced steam generator compared to former shell and tube type of steam generator. For the introduction of new steam generator, two design requirements are considered: flow area ratio between primary and secondary flow paths, and secondary side parallel channel flow oscillation. The results show that the overall volume of the steam generator can be significantly reduced with printed circuit type of steam generator.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.40 no.5
• /
• pp.266-279
• /
• 2003

In this paper, we propose machine printed character recognition methods which utilize the character type information and divide the character clusters. The characters are subdivided into a total of seven types, of which six types are for Hangul according to the grapheme combination fashions and one type for English characters, numerals, and symbols. According to the character type, we separate input character image into several recognition units and recognize them by using the direction angle feature. The recognition for each character type is completed by combining recognition units which are recognized by neural networks respectively For combining a total of seven character recognizers, we implemented seven methods such as switching method, integrating method, and their several variants. As experimental results, we obtained 98.2% recognition rate of simple switching method, 90.54% of integrating one, and between 97.35% and 98.65% of five variants.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.10
• /
• pp.3893-3897
• /
• 2010

Developer roller of LBP(laser beam printer) cartridge made with magnetic substance and density of magnetic flux was decreased with the elapse of a year. Owing to this reason, quality of printing was decreased with decreasing of magnetic flux. This study investigated about the elapse of a year of magnetic substance and possible about usage of recycling production.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.47 no.6
• /
• pp.58-63
• /
• 2010

In this paper, distributed tension observer for R2R process is proposed. The minimal order observer theory is utilized to design the distributed tension observer. The proposed method estimates the tension of a specific sub-process based on the speed and tension information from its adjacent sub-processes. Utilizing its properties, the proposed method can be applied to decentralized control structure. In order to achieve high estimation accuracy, sliding mode technique is also adopted to the proposed method.