• KIPS Transactions on Computer and Communication Systems
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• v.10 no.9
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• pp.251-260
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• 2021

Gait analysis is one of the research fields for obtaining various information related to gait by analyzing human ambulation. It has been studied for a long time not only in the medical field but also in various academic areas such as mechanical engineering, electronic engineering, and computer engineering. Efforts have been made to determine whether there is a problem with gait through gait analysis. In this paper, as a pre-step to find out gait abnormalities, it is investigated whether it is possible to differentiate whether experiment participants wear elderly simulation suit or not by applying gait data to machine learning models for the same person. For a total of 45 participants, each gait data was collected before and after wearing the simulation suit, and a total of six machine learning models were used to learn the collected data. As a result of using an artificial neural network model to distinguish whether or not the participants wear the suit, it showed 99% accuracy. What this study suggests is that we explored the possibility of judging the presence or absence of abnormality in gait by using machine learning.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.9 no.9
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• pp.819-831
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• 2019

The types of properties traded in modern times are rapidly increasing due to changes in consumption patterns. However, as the type of properties traded increases, estimation about the value of properties may become inaccurate. There is a problem that it is difficult for consumers to estimate the right value and the variety of trading forms makes it difficult to guarantee the reliability of value estimation As access to a variety of properties has expanded, these shortcomings are considered to be a factor that hinders the stability of the shared economic market. In this paper, to resolve this issue, we present a blockchain-based property contract service through a trusted broker. The developed service registers trusted brokers into smart contracts on the Ethereum blockchain and use them for the evaluation and contract process of properties. In addition, registered contents, proposals and contracts of properties are stored in the blockchain to ensure the reliability of the contract process. Every step of the contract process is stored in the smart contract, recorded in the transaction history of the blockchain, ensuring the reliability of the stored data. In addition, the entire process of registration, proposal, and contract is driven by smart contracts designed by state machine technology, enabling users to more securely control the contract process.

• Korea Science and Art Forum
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• v.37 no.5
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• pp.239-248
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• 2019

This study started from the need to improve one of shortcomings of synthetic PVAc adhesives - potential physical harm and environmental hazards to the workers or their users. As a matter of fact, PVAc adhesives are currently mainly used because of their convenience and economy for the production of woodcrafts. The purpose of this study was to develop natural adhesives through research on natural adhesives in step with the current increase of societal attention to environmental friendliness and rapid surge in their demand in the face of such problems. So, the study attempted research on the bases to develop natural adhesives for woodcraft, using cellulose extracts from wood - natural adhesive material. The findings of the study were as follows. Firstly, natural adhesives showed the improved effect in the field of adhesive strength, a basic physical property by 0.2 - 4 times compared with the existing materials and the study confirmed they had the similar or stable pH value. Besides, they had good reversibility, demonstrating their basic physical property as a natural adhesive for woodcraft. While, their durability to ultraviolet ray degradation also showed an excellent result value being better by 1.5 - 8.5 times than the existing materials. The study expects natural adhesives with improved and better performances compared with the existing materials could be developed, if further research on adhesive strength, antibiosis, conservative property were to continue by developing refinery technology for cellulose extracts from wood and rendering the functionality to them.

• Journal of Internet of Things and Convergence
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• v.7 no.4
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• pp.85-94
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• 2021

This study verified what differences in screen golf content characteristics, intention to reuse, customer satisfaction and economic value experienced by consumers according to the image feeling, expression method, and image color provided by screen golf graphic content. In addition, the purpose of this study was to analyze what kind of influence the content characteristics of screen golf have on the economic value and what kind of influence the intention to reuse and customer satisfaction have in this process. From September 1, 2021 to September 30, 2021, a survey of 225 copies of consumers using the screen golf course was conducted. For data processing, frequency analysis, factor analysis, reliability analysis, cluster analysis, chi-square analysis and 3-step mediated regression analysis were performed. The research results are as follows. First, the preferred image feeling showed a high level of clean and sophisticated feeling and the preferred expression method showed a high realistic image. In addition, the preferred image color showed a high level of green color. Second, there were differences in competitiveness, ease of use, sense of solidarity and realism according to the degree of consideration of graphic content and differences in consumer's intention to reuse, customer satisfaction, and economic value. Third, in the relationship between screen golf content characteristics and economic value, customer satisfaction and re-use intention had a mediating effect. Through this study, by providing basic data to derive the graphic design model of screen golf, the operating entity suggested a way to improve economic benefits and tried to contribute to the growth of the screen golf industry.

• The Korean Journal of Blood Transfusion
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• v.29 no.3
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• pp.310-319
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• 2018

Background: Research on next-generation sequencing (NGS)-based HLA typing is active. To resolve the phase ambiguity and long turn-around-time of conventional high resolution HLA typing, this study developed a NGS-based high resolution HLA typing method that can handle large-scale samples within an efficient testing time. Methods: For HLA NGS, the condition of nucleic acid extraction, library construction, PCR mechanism, and HLA typing with bioinformatics were developed. To confirm the accuracy of the NGS-based HLA typing method, the results of 192 samples HLA typed by SSOP and 28 samples typed by SBT compared to NGS-based HLA-A, -B and -DR typing. Results: DNA library construction through two-step PCR, NGS sequencing with MiSeq (Illumina Inc., San Diego, USA), and the data analysis platform were established. NGS-based HLA typing results were compatible with known HLA types from 220 blood samples. Conclusion: The NSG-based HLA typing method could handle large volume samples with high-throughput. Therefore, it would be useful for HLA typing of bone marrow donation volunteers.

• Applied Chemistry for Engineering
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• v.29 no.6
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• pp.690-695
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• 2018

Advanced oxidation processes (AOPs) composed of O3 and UV were applied to degrade penicillin (PEN). The degradation efficiency was evaluated in terms of changes in the absorbance (ABS) and total organic carbon (TOC). The combination of $O_3/H_2O_2/UV$ and $O_3/UV$ showed the best performance for the reduction of ABS (100% for 9 min) and TOC (70% for 60 min) values, although the mineralization was uncompleted under the experimental condition in this study. The change in biotoxicy was monitored with Escherichia coli susceptibility and Vibrio fischeri biofluorescence. The E. coli susceptibility was eliminated completely for 9 min by $O_3/UV$, and the toxicity to V. fischeri biofluorescence was 57% reduced by $O_3/H_2O_2/UV$. For the ultimate treatment of PEN, it is suggested that an AOP using $O_3/UV$ is followed by biological treatment, utilizing the enhanced biodegradability by the AOP. During 30 min of $O_3/UV$ treatment, the $BOD_5/COD$ ratio as an indication of biodegradability showed about 4-fold increment, compared to that of using a non-treated sample. TOC removal rate for AOP-pretreated PEN wastewater increased 55% compared to that of using the non-pretreated one through an aerobic biological treatment by Pseudomonas putida for artificial wastewater containing 20 mg/L of PEN. In conclusion, $O_3/UV$ process is recommended as a pretreatment step prior to an aerobic biological process to improve the ultimate degradation of penicillin.

• Journal of Multimedia Information System
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• v.5 no.4
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• pp.235-244
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• 2018

Potential maximum soil moisture retention (S) is a dominant parameter in the Soil Conservation Service (SCS; now called the USDA Natural Resources Conservation Service (NRCS)) runoff Curve Number (CN) method commonly used in hydrologic modeling for event-based flood forecasting (SCS, 1985). Physically, S represents the depth [L] soil could store water through infiltration. The depth of soil moisture retention will vary depending on infiltration from previous rainfall events; an adjustment is usually made using a factor for Antecedent Moisture Conditions (AMCs). Application of the method for continuous simulation of multiple storms has typically involved updating the AMC and S. However, these studies have focused on a time step where S is allowed to vary at daily or longer time scales. While useful for hydrologic events that span multiple days, this temporal resolution is too coarse for short-term applications such as flash flood events. In this study, an approach for deriving a time-variable potential maximum soil moisture retention curve (S-curve) at hourly time-scales is presented. The methodology is applied to the Napa River basin, California. Rainfall events from 2011 to 2012 are used for estimating the event-based S. As a result, we derive an S-curve which is classified into three sections depending on the recovery rate of S for soil moisture conditions ranging from 1) dry, 2) transitional from dry to wet, and 3) wet. The first section is described as gradually increasing recovering S (0.97 mm/hr or 23.28 mm/day), the second section is described as steeply recovering S (2.11 mm/hr or 50.64 mm/day) and the third section is described as gradually decreasing recovery (0.34 mm/hr or 8.16 mm/day). Using the S-curve, we can estimate the hourly change of soil moisture content according to the time duration after rainfall cessation, which is then used to estimate direct runoff for a continuous simulation for flood forecasting.

• Journal of Korea Technology Innovation Society
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• v.21 no.3
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• pp.1101-1126
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• 2018

As incipient organizations progress from formation to become larger entities, the procedures and rules that provided managerial and structural advantages in having established the organizations and promoting the growth impede the innovation and creativity vital to maintain the competitive advantage. Adopting Corporate Entrepreneurship (CE), large corporations have tried to overcome the dilemma and to sustain the innovation and creativity in order to effectively cope with harsh competitive realities. Recently, some advanced corporations are trying to enhance CE by setting up an internal venture program as a seed organization for CE. By making an in-depth analysis of the internal venture program, 'C-Lab' of Samsung that is promoting CE-related characteristics for enhancing CE, we attempt to shed light on (1) what kinds of environments should be built around the seed organization for CE (2) what are the major characteristics that should be promoted through the seed organization in relation to CE (3) What kinds of achievements can be made from the promoted characteristics (4) How the characteristics are spread over the entire organization. Based on the analysis, we suggest a generalized process in which CE can be enhanced. Since different approaches should be taken for managing the seed organization and spreading the characteristics depending on the strengths and weaknesses of a corporation, there must be the step, 'evaluation of corporate internal capabilities' in the process. We believe that each corporation can enhance CE by taking advantage of the process with reference to the C-Lab case study.

• Korean Journal of Materials Research
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• v.29 no.7
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• pp.437-442
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• 2019

Green $BaSi_2O_2N_2:0.02Eu^{2+}$ phosphor is synthesized through a two-step solid state reaction method. The first firing is for crystallization, and the second firing is for reduction of $Eu^{3+}$ into $Eu^{2+}$ and growth of crystal grains. By thermal analysis, the three-time endothermic reaction is confirmed: pyrolysis reaction of $BaCO_3$ at $900^{\circ}C$ and phase transitions at $1,300^{\circ}C$ and $1,400^{\circ}C$. By structural analysis, it is confirmed that single phase [$BaSi_2O_2N_2$] is obtained with Cmcm space group of orthorhombic structure. After the first firing the morphology is rod-like type and, after the second firing, the morphology becomes round. Our phosphor shows a green emission with a peak position of 495 nm and a peak width of 32 nm due to the $4f^65d^1{\rightarrow}4f^7$ transition of $Eu^{2+}$ ion. An LED package (chip size $5.6{\times}3.0mm$) is fabricated with a mixture of our green $BaSi_2O_2N_2$, and yellow $Y_3Al_5O_{12}$ and red $Sr_2Si_5N_8$ phosphors. The color rendering index (90) is higher than that of the mixture without our green phosphor (82), which indicates that this is an excellent green candidate for white LEDs with a deluxe color rendering index.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.2
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• pp.29-43
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• 2019

The calibration of microscopic traffic simulation models has received much attention in the simulation field. Although no standard has been established for it, a genetic algorithm (GA) has been widely employed in recent literature because of its high efficiency to find solutions in such optimization problems. However, the performance still falls short in simulation analyses to support fast decision making. This paper proposes a new calibration procedure using a dual GA and central composite design (CCD) in order to improve the efficiency. The calibration exercise goes through three major sequential steps: (1) experimental design using CCD for a quadratic response surface model (RSM) estimation, (2) 1st GA procedure using the RSM with CCD to find a near-optimal initial population for a next step, and (3) 2nd GA procedure to find a final solution. The proposed method was applied in calibrating the Gipps car-following model with respect to maximizing the likelihood of a spacing distribution between a lead and following vehicle. In order to evaluate the performance of the proposed method, a conventional calibration approach using a single GA was compared under both simulated and real vehicle trajectory data. It was found that the proposed approach enhances the optimization speed by starting to search from an initial population that is closer to the optimum than that of the other approach. This result implies the proposed approach has benefits for a large-scale traffic network simulation analysis. This method can be extended to other optimization tasks using GA in transportation studies.