• Journal of the Korean Applied Science and Technology
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• v.40 no.3
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• pp.534-546
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• 2023

In this study, we investigated the antioxidant and anti-winkle activity in human fibroblast cell (CCD-986sk) of Persimmon Leaves (PL) as a cosmetic ingredient. As a result of investigating antioxidant activity through electron-donating ability and ABTS⁺ radical scavenging assay, the PL showed concentration-dependent antioxidant activity similar to ascorbic acid, a control group, at a concentration of 1,000 ㎍/ml. As a result of investigating the anti-wrinkle effect through elastase inhibition and collagenase inhibition assay, the PL showed concentration-dependent antioxidant activity similar to epigallocatechin gallate, a control group, at a concentration of 1,000 ㎍/ml. As a result of measuring the synthesis rate of pro-collagen type I and the inhibition rate of MMP-1 in UVB-induced CCD-986sk cells, the control group EGCG showed a 90.2% pro-collagen synthesis rate at 20 ㎍/ml and PL showed an 88.5% synthesis rate at 30 ㎍/ml. In addition, the inhibition rate of MMP-1 of 33.0% and 40.8% were confirmed in EGCG 20 ㎍/ml and PL 30 ㎍/ml, respectively. As a result of measuring the protein expression of pro-collagen type I and MMP-1 in the PL through western blot, it was confirmed that the protein expression of pro-collagen type I increased, and MMP-1 decreased when the PL was treated together compared to the UVB alone group. According to the above experimental results, it is expected to be used as a natural product material for cosmetics by confirming that the PL prevent photoaging caused by UVB stimulation and have antioxidant and anti-wrinkle effects.

• Journal of Digital Convergence
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• v.10 no.10
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• pp.333-338
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• 2012

Human resource management is bringing the various changes with the IT technology. In particular, if HRM is non-scientific method such as group management, physical plant, working hours constraints, personal contacts, etc, the current enterprise human resources management(e-HRM) appeared in the individual dimension management, virtual workspace (for example: smart work center, home work, etc.), working time flexibility and elasticity, computer-based statistical data and the scientific method of analysis and management has been a big difference in the sense. Therefore, depending on changes in the environment, companies have introduced a variety of techniques as RFID card, fingerprint time & attendance systems in order to build more efficient and strategic human resource management system. In this paper, time and attendance, access control management system was developed using multi camera for 2D and 3D face recognition technology-based for efficient enterprise human resource management. We had an issue with existing 2D-style face-recognition technology for lighting and the attitude, and got more than 90% recognition rate against the poor readability. In addition, 3D face recognition has computational complexities, so we could improve hybrid video recognition and the speed using 3D and 2D in parallel.

• The Journal of Society for e-Business Studies
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• v.20 no.1
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• pp.183-199
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• 2015

Due to the Four Major Rivers Restoration Project, Nakdong River Estuary Barrage's designed flood quantity has been largely increased, and this has caused to construct several drainage gates at the right side of Eulsukdo island to secure the safety of downstream river area. For successful functioning of Nakdong River Estuary Barrage, such as flood control, disaster prevention, and the securing of sufficient water capacity, drainage gates at the both sides of island have to operate systematically and reliably. To manage this under restricted personnel and resources, we have implemented the IOS (Integrated Operation System) by integrating previous facilities and resources via information and communication technologies. The IOS has been designed to have higher availability and fault tolerance to function continuously even with the partial system's failure under the emergency situation like flood. Operators can use the system easily and acknowledge alarms of facilities through its IWS (Integrated Warning System) earlier. Preparing for Integrated Water Resources Management and Smart Water Grid, the architecture of IOS conformed to open system standards which will be helpful to link with the other systems easily.

• Smart Structures and Systems
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• v.20 no.1
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• pp.61-74
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• 2017

One of the most reliable and simplest tools for structural vibration control in civil engineering is Tuned Mass Damper, TMD. Provided that the frequency and damping parameters of these dampers are tuned appropriately, they can reduce the vibrations of the structure through their generated inertia forces, as they vibrate continuously. To achieve the optimal parameters of TMD, many different methods have been provided so far. In old approaches, some formulas have been offered based on simplifying models and their applied loadings while novel procedures need to model structures completely in order to obtain TMD parameters. In this paper, with regard to the nonlinear decision-making of fuzzy systems and their enough ability to cope with different unreliability, a method is proposed. Furthermore, by taking advantage of both old and new methods a fuzzy system is designed to be operational and reduce uncertainties related to models and applied loads. To design fuzzy system, it is required to gain data on structures and optimum parameters of TMDs corresponding to these structures. This information is obtained through modeling MDOF systems with various numbers of stories subjected to far and near field earthquakes. The design of the fuzzy systems is performed by three methods: look-up table, the data space grid-partitioning, and clustering. After that, rule weights of Mamdani fuzzy system using the look-up table are optimized through genetic algorithm and rule weights of Sugeno fuzzy system designed based on grid-partitioning methods and clustering data are optimized through ANFIS (Adaptive Neuro-Fuzzy Inference System). By comparing these methods, it is observed that the fuzzy system technique based on data clustering has an efficient function to predict the optimal parameters of TMDs. In this method, average of errors in estimating frequency and damping ratio is close to zero. Also, standard deviation of frequency errors and damping ratio errors decrease by 78% and 4.1% respectively in comparison with the look-up table method. While, this reductions compared to the grid partitioning method are 2.2% and 1.8% respectively. In this research, TMD parameters are estimated for a 15-degree of freedom structure based on designed fuzzy system and are compared to parameters obtained from the genetic algorithm and empirical relations. The progress up to 1.9% and 2% under far-field earthquakes and 0.4% and 2.2% under near-field earthquakes is obtained in decreasing respectively roof maximum displacement and its RMS ratio through fuzzy system method compared to those obtained by empirical relations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.1-8
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• 2016

Current sensors are used widely in the fields of current control, monitoring, and measuring. They have become more popular with the increasing demand for smart grids in a power network, generation of renewable energy, electric cars, and hybrid cars. Although open loop Hall effect current sensors have merits, such as low cost, small size, and weight, they have low accuracy. This paper describes the design and fabrication of a 300A open loop current sensor that has high accuracy and temperature performance. The core of the current sensor was calculated numerically and the signal conditioning circuits were designed using circuit analysis software. The characteristics of the manufactured open loop current sensor of 300 A class was measured at currents up to 300 A. According to the test of the current sensor, the accuracy error and linearity error were 0.75% and 0.19%, respectively. When the temperature compensation was carried out with the relevant circuit, the temperature coefficients were less than $0.012%/^{\circ}C$ at temperatures between $-25^{\circ}C$ and $85^{\circ}C$.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.4
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• pp.577-582
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• 2016

This Study focused on the development of SMPS (Switching Mode Power Supply) to supply the constant votage and current nevertheless LED fluorescent Light generated the electric noise (with Harmonics) and Inrush current at instant time of turn-on and off. Recently, according to the Green policy in government, the LED fluorescent Lighter showed the rapidly increasing tend as indoor and outdoor Lighter. But, because of costs, LED fluorescent Light not considered and neglected the following items; power factor, efficiency, Harmonics and Inrush current. So, we are developed the SMPS about 3 key issues as follows: 1st, power factor and efficiency is 85%. 2nd, the switching noisy by harmonic is minimized. 3rd, the Inrush current at turn on and off time is reduced the minimum 0.3 A after $100{\mu}sec$ on turnon time. The proposed SMPS adjusted by LNK 409 driver (included the high frequency modulation function). Although, the developed SMPS maintained the about 85% of power factor and efficiency. but, the SMPS must be generated low heat by the variation of minute load current at switching timing. To improve the above weak point, the developed SMPS have the feedback monitoring circuit between input side and output side to maintain the power factor and efficiency. Also, we are studied the time-constant of control circuit to output the constant voltage and current nevertheless the load disturbance of LED lighting. The LED fluorescent Light of 46W is checked the above items.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.13 no.1
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• pp.145-155
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• 2018

The matter of cultivating entrepreneurship and will to start a business of university students majoring in agriculture and life sciences and college students majoring in agriculture as a future leader in the sector is a very important object of study. However, the discussion on entrepreneurship, establishment of a business and venture based on creative technology and innovative management have been scarcely had, because traditionally the majority of agricultural business has been a small-sized and simple business run by a small farmer. Education for starting an agricultural business in agriculture industry has been ignored even in the developed countries. ICT and AI(artificial intelligence)-based smart agriculture in the 4th Industrial Revolution Age is emerging as a new growth potential of our agriculture industry. Thus, the interest in farmers to start a business and venture agriculture is growing in the agriculture industry. Accordingly, the study draws the influence factors regarding the effect of the planned behavior of the university students who take part in the education course for starting an agricultural business and an agricultural venture business on entrepreneurship and will to start the business and conducts the empirical analysis. The businessmen who newly join the agriculture industry should perform the technical innovation and the creative business activities to be able to compete in the agriculture industry.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.12 s.159
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• pp.1800-1809
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• 2006

The wearable technology takes the concept of clothing over its limits -integrating software, communication devices, and sensors into the garments to enable them to 'think' for the wearer. A dress is no longer just a dress, but a dress as well as a wearable computer interface. This wearable computer network transports the data power and control signals within the wearer's personal space. The purpose of this thesis is to explore the wearable technology from a commercial perspective. On this theme I made a survey and interviewed 20 men and 20 women in London to find out if many people are familiar with the concept of the wearable technology. The main results of this study include: Firstly, according to the survey, people are not familiar with the concept of the wearable technology, and further people thought negatively about the wearable computer rather than positively they worried about hish prices, inappropriate technology and side effects. Secondly, people are especially interested in items related to health and security, so in this area there are huge potential opportunities for the wearable technology, Finally, wearable technology needs to be a simplified set of interactive devices, which are in a user friendly format for marketability because convenience was one of the biggest concern for consumers. Therefore, development of the wearable computer should be promoted not only through computer engineering but also through the connection with human lift.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.97-104
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• 2018

Recently, many studies have examined UAVs (unmanned aerial vehicles), which can replace and supplement existing surveying sensors, systems, and images. This study focused on the use of UAV images and assessed the possibility of utilization in areas where it is difficult to obtain GCPs (ground control points), such as disasters. Therefore, 3D (dimensional) pointcloud data were generated using UAV images and the absolute/relative accuracy of the generated model data using GCPs and without GCPs was assessed. The results showed the 3D shape pointcloud generated by UAV image matching was proven if the relative accuracy was set, regardless of whether GCPs were used or not; the quantitative measurement error rate was within 1%. Even if the absolute accuracy was low, the 3D shape pointcloud that had been post processed quickly was sufficient to be utilized when it is impossible to acquire GCPs or urgent analysis is required. In particular, the results can obtain quantitative measurements and meaningful data, such as the length and area, even in cases with the ground reference point surveying and post-process.

• The Journal of the Korea Contents Association
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• v.14 no.7
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• pp.395-406
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• 2014

This research observes how an adolescent's usage of social network services is related with media use time, and also tries to verify how a parent's participation in acting to limit usage time serves as a mediating effect. For this analysis, data from The Korean Information Society Development Institute [Korea Media Panel Research] was used, being a survey conducted on 1,572 students from primary to secondary and high schools nationwide. The subjects' gender in the final analysis was 818 male students and 754 female students. In addition, primary school students consisted of 672 individuals, 416 were from secondary and 484 from high schools. To verify the appropriateness of the model proposed in this research, analyzed through the structural equation, using social network services(SNS) was not shown to have an effect on media usage time. However, there was an indirect effect from the use of alternative activities. In addition, the parent's limitation of usage showed no effect on media use time. This research attempts to identify the reasons why parents' limiting the usage time, along with alternative activities, do not have any significant effect in reducing media usage time in this era of smart media evolution. Further, this research hopes to suggest meaningful and political implications for the nation and society to understand and resolve media addiction.