• Journal of Internet of Things and Convergence
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• v.9 no.3
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• pp.61-67
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• 2023

In order to optimize the pulse electroforming copper process, a double hidden layer BP (Back Propagation) neural network is constructed. Through sample training, the mapping relationship between electroforming copper process conditions and target properties is accurately established, and the prediction of microhardness and tensile strength of the electroforming layer in the pulse electroforming copper process is realized. The predicted results are verified by electrodeposition copper test in copper pyrophosphate solution system with pulse power supply. The results show that the microhardness and tensile strength of copper layer predicted by "3-4-3-2" structure double hidden layer neural network are very close to the experimental values, and the relative error is less than 2.32%. In the parameter range, the microhardness of copper layer is between 100.3~205.6MPa and the tensile strength is between 112~485MPa.When the microhardness and tensile strength are optimal,the corresponding process conditions are as follows: current density is 2A-dm-2, pulse frequency is 2KHz and pulse duty cycle is 10%.

• Educational Technology International
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• v.11 no.1
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• pp.93-117
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• 2010

The purpose of this study was to develop the problem solving instruction facilitating novice learner to represent the problem. For the purpose, we mainly focused on three aspects of problem solving. First, learner should represent the targeted problem and its solutions for problem solving. Second, from crucial notions of cognitive load theory, learner's mental load should be optimized for problem representation. Third, for optimizing students' mental load, experts may support making their thinking more visible and mapping from their intuition to expert practice. We drew the design principles as follows. First, since providing worked examples for the targeted problem has been considered to minimize analogical errors as well as reduce cognitive load in problem representation at line of problem solving and instructional research, it is needed to elaborate the way of designing. The worked example alternatively corresponds to expert schema that consists of domain knowledge as well as strategies for expert-like problem representation and solution. Thus, it may help learner to represent what the problem is and how to solve it in problem space. Second, principle can be that expert should scaffold learner's self-explanations. Because the students are unable to elicit the rationale from worked example, the expert's triggering scaffold may be critical in that process. The unexplained and incomplete parts of the example should be completed not by expert's scaffold but by themselves. Critical portion of the expert's scaffold is to explain about how to apply and represent the given problem, since students' initial representations may be reached at superficial or passive pattern of example elaboration. Finally, learner's mental model on the designated problem domain should be externalized or visualized for one's reflection as well as expert's scaffolding activities. The visualization helps learner to identify one's partial or incorrect model. The correct model of learner could be constructed by expert's help.

• Geophysics and Geophysical Exploration
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• v.10 no.4
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• pp.383-392
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• 2007

Karstic features and mining-related cavities not only lead to severe restrictions in land utilizations, but also constitute serious concern about geohazard and groundwater contamination. A microgravity survey was applied for detecting, mapping and monitoring karstic cavities in the test site at Muan prepared by KIGAM. The gravity data were collected using an AutoGrav CG-3 gravimeter at about 800 stations by 5 m interval along paddy paths. The density distribution beneath the profiles was drawn by two dimensional inversion based on the minimum support stabilizing functional, which generated better focused images of density discontinuities. We also imaged three dimensional density distribution by growing body inversion with solution from Euler deconvolution as a priori information. The density image showed that the cavities were dissolved, enlarged and connected into a cavity network system, which was supported by drill hole logs. A time-lapse microgravity was executed on the road in the test site for monitoring the change of the subsurface density distribution before and after grouting. The data were adjusted for reducing the effects due to the different condition of each survey, and inverted to density distributions. They show the change of density structure during the lapsed time, which implies the effects of grouting. This case history at the Muan test site showed that the microgravity with accuracy and precision of ${\mu}Gal$ is an effective and practical tool for detecting, mapping and monitoring the subsurface cavities.

• The KIPS Transactions:PartD
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• v.12D no.4 s.100
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• pp.627-636
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• 2005

The Intelligent Web Service is proposed for the purpose of automatic discovery, invocation, composition, inter-operation, execution monitoring and recovery web service through the Semantic Web and the Agent technology. To accomplish this Intelligent Web Service, the Ontology is a necessity for reasoning and processing the knowledge by the computer. However, creating service ontology, for the intelligent web service, has two problems not only consuming a lot of time and cost depended on heuristic of service developer, but also being hard to be mapping completely between service and service ontology. Moreover, the markup language to describe the service ontology is currently hard to be learned by the service developer In a short time. This paper proposes the efficient way of designing and creating the service ontology using MDA methodology. This proposed solution reuses the creating model in terms of desiEninE and constructing Web Service Model using UML based on MDA. After converting the Platform-Independent Web Service Model to the dependent model of OWL-S which is a Service Ontology description language, it converts to OWL-S Service Ontology using XMI. This proposed solution has profits, oneis able to be easily constructed the Service Ontology by Service Developers, the other is enable to be created the both service and Service Ontology from one model. Moreover, it can be effective to reduce the time and cost as creating Service Ontology automatically from a model, and calmly dealt with a change of outer environment like as the platform change. This paper cites an instance for the validity of designing Web Service model and creating the Service Ontology, and validates whether the created Service Ontology is valid or not.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.249-249
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• 2013

Surface-enhanced Raman spectroscopy (SERS) is a sensitive approach to detect and to identify a variety of molecules. To enhance the Raman signal, optimization of the gap between nanostructures is quite important. One-dimensional materials such as nanowires, nanotubes, and nanograsses have great potential to be used in SERS due to their unique sizes and shape dependent characteristics. In this study we investigate a simple way to fabricate SERS substrates based on randomly grown copper oxide (CuO) nanowires. CuO nanograss is fabricated on pre-cleaned Cu foils. Cu oxidized in an ammonium ambient solution of 2.5 M NaOH and 0.1 M $(NH_4)_2S_2O_8$ at $4^{\circ}C$ for 10, 30, and 60 minutes. Then, Cu(OH)2 nanostructures are formed and dried at $180^{\circ}C$ for 2 h. With the drying process, the Cu(OH)2 nanostructure is transformed to CuO nanograss by dehydration reaction. CuO nanograss are grown randomly on Cu foil with the average length of 10 ${\mu}m$ and the average diameter of a 100 nm. CuO nanograsses are covered by Ag with various thicknesses from 10 to 30 nm using a thermal evaporator. Then, we immerse uncoated and Ag coated CuO nanowire samples of various oxidation times in a 0.001M methanol-based 4-mercaptopyridine (4-Mpy) in order to evaluate SERS enhancement. Raman shift and SERS enhancement are measured using a Raman spectrometer (Horiba, LabRAM ARAMIS Spectrometer) with the laser wavelength of 532 nm. Raman scattering is believed to be enhanced by the interaction between CuO nanograss and Ag island film. The gaps between Ag covered CuO nanograsses are diverse from <10 nm at the bottom to ~200 nm at the top of nanograsses. SERS signal are improved where the gaps are minimized to near 10s of nanometers. There are many spots that provide sufficiently narrow gap between the structures on randomly grown CuO nanograss surface. Then we may find optimal enhancement of Raman signal using the mapping data of average results. Fabrication of CuO nanograss based on a solution method is relatively simple and fast so this result can potentially provide a path toward cost effective fabrication of SERS substrate for sensing applications.

• Journal of Korean Philosophical Society
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• v.141
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• pp.43-62
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• 2017

The main purpose of this paper is to survey the debates between Searle and Smith over the problem of "freestanding Y terms" in Searle's conception of social reality, and offer a viable solution, drawing on the experientialist conception of symbolic experience. Smith raises the problem of "freestanding Y term" against Searle's formula "X counts as Y in C" that there may be some cases where we cannot identify an X term to which an Y term refers. In case of an abstract concept such as equity, we may not find exactly what it stands for. That is, we cannot identify exactly what(X term) counts as equity. If there is nothing like an X for Y term, we can regard anything as equity, which may disrupt Searle's formula. Understandably, Smith does not say that the problem dismantles Searle's whole conception of social reality. Instead, Smith intends to show that Searle's formula is neither complete nor specific enough. Apparently, Searle admits that there may be freestanding Y terms and tries to articulate it within his formula, which does not seem to work. I suggest that the experientialist account of symbolic experience may serve to dissolve Smith's challenge, without modifying Searle's original formula. According to the experientialist conception of symbolization, we symbolically map some portion of our experience onto a physical object, which serves as a signifier, and we then understand and experience the signifier "in terms of" the mapped portion of experience. Thus, we experience certain buildings and some relevant people, say students, staffs, and professors in terms of "university." The status functions of university have been created by means of symbolic mappings, which change the way we understand and experience the buildings and people. In this picture, there need not be any notions such as "one-to-one correspondence" between X terms and Y terms. In this way, Searle may maintain his original formula, while dissolving, not answering, Smith's challenge. What Searle needs is a more appropriate theory of symbolization, part of which has been articulated by the experientialist account of symbolic experience.

• Journal of KIISE:Computing Practices and Letters
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• v.13 no.7
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• pp.508-519
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• 2007

Flash memory based storage has been used in various mobile systems and now is to be used in Laptop computers in the name of Solid State Disk. The Flash memory has not only merits in terms of weight, shock resistance, and power consumption but also limitations like erase-before-write property. To overcome these limitations, Flash memory based storage requires special address mapping software called FTL(Flash-memory Translation Layer), which often performs merge operation for block recycling. In order to reduce block recycling cost in NAND Flash memory based storage, we introduce another block recycling scheme which we call migration. As a result, the FTL can select either merge or migration depending on their costs for each block recycling. Experimental results with Postmark benchmark and embedded system workload show that this cost-based selection of migration/merge operation improves the performance of Flash memory based storage. Also, we present a solution of macroscopic optimal migration/merge sequence that minimizes a block recycling cost for each migration/merge combination period. Experimental results show that the performance of Flash memory based storage can be more improved by the macroscopic optimization than the simple cost-based selection.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.129-129
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• 2016

Graphene, as a single layer of $sp^2$-bonded carbon atoms packed into a 2D honeycomb crystal lattice, has attracted much attention due to its outstanding properties. In order to synthesize high quality graphene, transition metals, such as nickel and copper, have been widely employed as catalysts, which needs transfer to desired substrates for various applications. However, the transfer steps are not only complicated but also inevitably induce defects, impurities, wrinkles, and cracks of graphene. Furthermore, the direct synthesis of graphene on dielectric surfaces has still been a premature field for practical applications. Therefore, cost effective and concise methods for transfer-free graphene are essentially required for commercialization. Here, we report a facile transfer-free graphene synthesis method through nickel and carbon co-deposited layer. In order to fabricate 100 nm thick NiC layer on the top of $SiO_2/Si$ substrates, DC reactive magnetron sputtering was performed at a gas pressure of 2 mTorr with various Ar : $CH_4$ gas flow ratio and the 200 W DC input power was applied to a Ni target at room temperature. Then, the sample was annealed under 200 sccm Ar flow and pressure of 1 Torr at $1000^{\circ}C$ for 4 min employing a rapid thermal annealing (RTA) equipment. During the RTA process, the carbon atoms diffused through the NiC layer and deposited on both sides of the NiC layer to form graphene upon cooling. The remained NiC layer was removed by using a 0.5 M $FeCl_3$ aqueous solution, and graphene was then directly obtained on $SiO_2/Si$ without any transfer process. In order to confirm the quality of resulted graphene layer, Raman spectroscopy was implemented. Raman mapping revealed that the resulted graphene was at high quality with low degree of $sp^3$-type structural defects. Additionally, sheet resistance and transmittance of the produced graphene were analyzed by a four-point probe method and UV-vis spectroscopy, respectively. This facile non-transfer process would consequently facilitate the future graphene research and industrial applications.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.5
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• pp.356-362
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• 2013

An attempt has been made to optimize elongated rotating arc plasma $NH_3$ scrubber. Among diverse semiconductor processes, diffusion and implantation process inevitably produce $NH_3$ as byproduct and efficient dry process for the decomposition of $NH_3$ is required. Plasma process does not produce NOx that is commonly produced in combustion process and there is no problem of deactivation, usually experienced in catalyst process. However, plasma process uses electrical energy and needs to be optimized to achieve feasibility of application. In this work, mode control of rotating arc is presented as tentative solution for the possible optimization of the process. Based on existing rotating arc, scale-up and following mode mapping was tried. Proposed reactor design was evaluated in the $NH_3$ decomposition process and revealed that optimization scheme is at hand. In the experiment of full scale scrubber including heat exchanger, the process gave more stable and efficient process of $NH_3$ decomposition.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.6
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• pp.1011-1021
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• 2016

This study performs the potential flood hazard analysis by applying elevation data, soil data and land use data. The susceptibility maps linked to elevation, soil and land use are combined to develop the new types of flood hazard map such as runoff production map and runoff accumulation map. For the development of the runoff production map, land use, soil thickness, permeability, soil erosion and slope data are used as runoff indices. For the runoff accumulation map, elevation, knick point and lowland analysis data are used. To derive an integrated type of flood potential hazard, a TOPSIS (The Technique for Order of Preference by Similarity to Ideal Solution) technique, which is widely applied in MCDM (Multi-Criteria Decision Making) process, is adopted. The indices applied to the runoff production and accumulation maps are considered as criteria, and the cells of analysis area are considered as alternatives for TOPSIS technique. The model is applied to Gamcheon watershed to evaluate the flood potential hazards. Validation with large scale data shows the good agreements between historical data and runoff accumulation data. The analysis procedure presented in this study will contribute to make preliminary flood hazard map for the public information and for finding flood mitigation measures in the watershed.