• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.234-234
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• 2010

Most high efficiency silicon solar cells use a passivated selective emitter. It have been an important research subject for crystalline silicon solar cells for decades. It is being used in production for high efficiency solar cells. Most of the selective emitter process require expensive extra masking, etching steps, and a double diffusion process making selective emitters not cost effective. In this paper, we study method for single diffusion step selective emitter process as an alternative to not cost effective double diffusion process. Cost effective selective emitter that the efficiency should be increased significantly (mare than 0.2%) and that the process should simple, robust and cheap.

• Journal of the Korean Society of Earth Science Education
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• v.4 no.3
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• pp.267-277
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• 2011

The purpose of this study is to examine the effect of IIM-based science writhing lesson on the science process skills and self-directed learning in elementary science-gifted students. To verify research problems, the subjects of this study were forth-grade students selected from one classes of an elementary science-gifted class in Busan National Universty of education : the research group is composed of twenty students who were participated in IIM-based science writing lessons. During 12 weeks, the IIM-based science writing lessons was executed in the reasearch group. Post-test showed following results: First, the research group showed a significant improvement in the science process skill. We look into detailly this, the research group showed a significant improvement in the basis science skill. The sub-factor 'expectation' of the science process skill effects a significant improvement. Second, the research group showed a significant improvement in the self-directed learning. In conclusion, IIM-based science writing lesson was more effective on science process skill and self-directed learning. However, since the study has a limit on an object of the study and the applied program, the additional studies need to be conducted with an extended comparative group and program.

• Journal of the Korean Society of Earth Science Education
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• v.4 no.1
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• pp.20-31
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• 2011

The purpose of this study is to examine the effect of PBL-based astronomical observation on the science process skills and scientific attitudes in elementary science-gifted students. To verify research problems, the subjects of this study were forth-grade students selected from one classes of an elementary science-gifted class in Busan National University of education : the research group is composed of twenty students who were participated in PBL-based astronomical observation program. During four weeks, the PBL-based astronomical observation program instruction was executed in the reasearch group. Post-test showed following results: First, the research group showed a significant improvement in the science process skill. We look into detailly this, the research group showed a significant improvement in the basis science skill. The sub-factor 'expectation' of the science process skill effects a significant improvement. Second, the research group showed a significant improvement in the scientific attitudes. In conclusion, PBL-based astronomical observation program was more effective on science process skill and scientific attitudes. However, since the study has a limit on an object of the study and the applied program, the additional studies need to be conducted with an extended comparative group and program.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.186-189
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• 2006

The flexible organic thin film transistor (OTFT) array to use as a switching device for an organic light emitting diode (OLED) was designed and fabricated in the microcontact printing and room temperature process. The gate, source, and drain electrode patterns of OTFT were fabricated by microcontact printing process. The OTFT array with dielectric layer and organic active semiconductor layer formed at room temperature or at a temperature lower than $40^{\circ}C$. The microcontact printing process using SAM and PDMS stamp made it possible to fabricate OTFT arrays with channel lengths down to even submicron size, and reduced the fabrication process by 10 steps compared with photolithography. Since the process was done in room temperature, there was no pattern shrinkage, transformation, and bending problem appeared. Also, it was possible to improve electric field mobility, to decrease contact resistance, to increase close packing of molecules by SAM, and to reduce threshold voltage by using a big dielectric.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.10a
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• pp.119-123
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• 2002

Liquefied Natural Gas(LNG) continues to attract modern gas industries as well as domestic markets as their main energy source in the recent years. This is mainly because LNG is inherently cleaner and more energy efficiency than other fuels. Offshore LNG production plant is of interest to many oil producing companies all over the world. This article discuss about the production process encountered while developing such a production facility. Typical offshore oil and gas processing required for oil stabilization and other optional units that can be added to the facilities. The production process can broadly be divided into five major units namely, (i) Oil Stabilization unit, (ii) Gas Treatment unit, (iii) Methane Recovery unit, (iv) Distillation unit and (v) LNG Liquefaction unit. The process simulation was carried out for each unit with a given wellhead composition. The topside facilities of offshore LNG production plant will be very similar to the process adopted in offshore processing platform along with the typical onshore LNG production plant. However, the process design problems associated with FPSO motion to be taken care of while developing floating LNG production plant.

• Journal of Radiation Protection and Research
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• v.48 no.2
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• pp.77-83
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• 2023

Background: The purpose of this study is to purify uranium (U[VI])-contaminated soil-flushing effluent using the precipitation-distillation process for clearance. Precipitation and distillation are commonly used techniques for water treatment. We propose using a combination of these methods for the simple and effective removal of U(VI) ions from soil-flushing effluents. In addition, the U concentration (Bq/g) of solid waste generated in the proposed treatment process was analyzed to confirm whether it satisfies the clearance level. Materials and Methods: Uranium-contaminated soil was decontaminated by soil-flushing using 0.5 M sulfuric acid. The soil-flushing effluent was treated with sodium hydroxide powder to precipitate U(VI) ions, and the remaining U(VI) ions were removed by phosphate addition. The effluent from which U(VI) ions were removed was distilled for reuse as a soil-flushing eluent. Results and Discussion: The purification method using the precipitation-distillation process proposed in this study effectively removes U(VI) ions from U-contaminated soil-flushing effluent. In addition, most of the solid waste generated in the purification process satisfied the clearance level. Conclusion: The proposed purification process is considered to have potential as a soil-flushing effluent treatment method to reduce the amount of radioactive waste generated.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.73-75
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• 2007

Micro-cell LC film and polymer network liquid crystal (PNLC) film by using continuous compatible process have been developed . A high-contrast micro-cell LC film has a strong potential as a high-performance flexible device. PNLC film has the low driving voltage. Both films show the characteristics of lightness, thinness and mechanical stability.

• Applied Science and Convergence Technology
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• v.26 no.6
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• pp.179-183
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• 2017

The direct growth method is simplified manufacturing process used to avoid damages and contaminants from the graphene transfer process. In this paper, graphene nano-walls (GNWs) were direct synthesized using electron cyclotron resonance (ECR) plasma by varying the $CH_4/H_2$ gas flow rate on the copper foil at low temperature (without substrate heater). Investigations were carried out of the changes in the morphology and characteristic of GNWs due to the relative intensity of hydrocarbon radical and molecule in the ECR plasma. The results of these investigations were then discussed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.8
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• pp.2316-2332
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• 2024

In this paper, we introduce a web-based system that leverages the capabilities of the ρ(rho)-algorithm, which is a Structure Information Control Net (SICN)-oriented process mining algorithm, with open-source platforms, including Django, Graphviz, and Cytoscape, to facilitate the rediscovery and visualization of business process models. Our approach involves discovering SICN-oriented process models from process instances from the IEEE XESformatted process enactment event logs dataset. This discovering process is facilitated by the ρ-algorithm, and visualization output is transformed into either a JSON or DOT formatted file, catering to the compatibility requirements of Cytoscape or Graphviz, respectively. The proposed system utilizes the robust Django platform, which enables the creation of a userfriendly web interface. This interface offers a clear, concise, modern, and interactive visualization of the rediscovered business processes, fostering an intuitive exploration experience. The experiment conducted on our proposed web-based process discovery system demonstrates its ability and efficiency showing that the system is a valuable tool for discovering business process models from process event logs. Its development not only contributes to the advancement of process mining but also serves as an educational resource. Readers, students, and practitioners interested in process mining can leverage this system as a completely free process miner to gain hands-on experience in rediscovering and visualizing process models from event logs.

• Journal of the Microelectronics and Packaging Society
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• v.20 no.4
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• pp.65-68
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• 2013

A novel bumping process using solder bump maker (SBM) is developed for fine-pitch flip chip bonding. It features maskless screen printing process. A selective solder bumping mechanism without the mask is based on the material design of SBM. Maskless screen printing process can implement easily a fine-pitch, low-cost, and lead-free solder-on-pad (SoP) technology. Its another advantage is ternary or quaternary lead-free SoP can be formed easily. The process includes two main steps: one is the thermally activated aggregation of solder powder on the metal pads on a substrate and the other is the reflow of the deposited powder on the pads. Only a small quantity of solder powder adjacent to the pads can join the first step, so a quite uniform SoP array on the substrate can be easily obtained regardless of the pad configurations. Through this process, an SoP array on an organic substrate with a pitch of 130 ${\mu}m$ is, successfully, formed.