• Journal of Korean Home Economics Education Association
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• v.32 no.1
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• pp.1-14
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• 2020

The main purpose of this research was to develop upcycled DIY kits made from subway billboard material to make living products. This study was conducted based on the following four stages of design process: research and analyses, DIY kits' design direction establishment, completion of DIY kits, and implementation and evaluation. Through this study, we developed DIY kits for pouches, tissue cases and pencil cases. In the implementation and evaluating stage, we chose to make pouches because it includes zipper attachment process. Implementation was conducted by recruiting four high school students and four female adults. As a result, we found the following: First, the participants were able to make pouches in less than an hour. Second, pouch making has a moderate degree of difficulty. Third, video instructions should be slowed down. Forth, materials need to be improved. Fifth, environmental awareness was improved by using unfamiliar subway billboard materials. The upcycled DIY kits, developed as a result of this study, can be used as eco-friendly education sources for secondary school students as well as for adults' healing hobby.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.2
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• pp.119-125
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• 2015

A concentration meter is widely used at purification plants, sewage treatment plants and waste water treatment plants to sort and transfer high concentration sludge and to control the amount of chemical dosage. When the strange substance is contained in the sludge, however, the attenuation of ultrasonic wave could be increased or not be transmitted to the receiver. At that case, the value of concentration meter is higher than the actual density value or vibrated up and down. It has also been difficult to automate the residuals treatment process according to the problems as sludge attachment or damage of a sensor. Multi-beam ultrasonic concentration meter has been developed to solve these problems, but the failure of the ultrasonic beam of a specific concentration measurement value degrade the performance of the entire system. This paper proposes the method to improve the accuracy of sludge concentration rate by choosing reliable sensor values and learning them by proposed algorithm. The prediction algorithm is chosen as neuro-fuzzy model, which is tested by the various experiments.

• Korean Journal of Construction Engineering and Management
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• v.10 no.5
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• pp.67-75
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• 2009

While the trend of all industries recently lies in combination, construction industry is much interested in enhancing efficiency and competitiveness in the aspect of site control by adopting RFID. Though RFID has been applied to diverse areas thus far, it cannot be easily applied to construction industry due to diverse physical, chemical and use-environmental properties of construction materials. Furthermore, it is rarely applied to the site because of many problems in its application. It is required to prepare RFID code issuance and system that can systematically control the code as well as to research the standardization of frequency, specification, protocol, package method, recognition method, etc in order to apply RFID to construction industry. In this research, RFID code issuance and management program are proposed as a part of program research to apply RFID. Furthermore, the restricted matters of existing RFID tag are drawn to produce pilot product of RFID tag that can solve it so as to perform site application test. According to the experiment, effective recognition distance varies depending on material/environmental property and control efficiency changes depending on attachment method and application method. Thus, preparing diverse restrictive factors and solutions by systematically analyzing control method(medium, process) of current architecture materials and applying it to construction site can be the way to successfully apply RFID.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.3
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• pp.593-610
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• 1996

The objective of this paper was to evaluate the shear bond strength of luting glass ionomer cement with defferent calcium based solution treatment on dentin surface. 120 extracted human teeth were classified into 12 group based on presence of smear layer on dentin surface and type of treatment solution. Smear layer remove on dentin surface was done using 6% citric acid for 60 seconds. Five different dentin surface treatment solutions(calcium acetate, calcium carbonate, clacium chlorided, calcium hydroxide, and calcium phosphate) were evaluated in this study. After surface modification, metal ring(inner diameter : 3mm, depth : 1mm) was placed to expose the same dentin surface area and inner space was filled with luting glass ionomer cement according to the recommended procedure for stadard clinical procedure. The shear bond strength of glass ionomer cement was determined after 24 hours. SEM was used for the evaluation of the surface morphologic changes and EDAX analysis was done for determination of the change of the calcium contents of treated dentin. Follwing conclusion can be drawn : 1. In the group of the dentin surface with smear layer, the calcium carbonate solution was the most effective for the increase of the clacium content and the shear bond strength of glass ionomer cement to dentin surfaces. 2. In the group of the calcium carbonate treated dentin with msear layer, the shear bond strength was increased twice compared to the control group and cohesive failure mode was observed. 3. The shear bond strength of cement was increased significantly be the removal of smear layer using 6% citric aicd. However, additional calcium solution treatments were not effective for further bond strength increase. 4. The shear bond strength of cement was significantly improved by both of the removal of smear layer and the calcium solution treatment, and the former was more effective for bond strength improvement. 5. The smear layer removed/calcium solution treated groups showed dentinal tubule obstruction and crystal attachment in SEM evaluation. However, the shear bond strengths of these groups were not increased compared to the smear layer removed/no dentin treatment group.

• Journal of Periodontal and Implant Science
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• v.31 no.2
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• pp.345-356
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• 2001

The purpose of the present study was to evaluate the clinical efficacy of guided tissue regeneration(GTR) using resorbable polylactic/polyglycolic copolymer(PLA/PGA) membrane in mandibular class II furcation involvement and to compare it to the clinical efficacy of only flap operation. Both procedures were conducted in 5 patients with class II furcation involvements. After 6 months of follow up, the probing pocket depth, clincial attachment level, bone probing depth, and radiographic changes were compared, and the following results were obtained: 1. GTR using PLA/PGA demonstrated a statistically significant reduction in probing pocket depth and bone probing depth, and the control group demonstrated a statistically significant reduction in bone probing depth. 2. The comparison between the experimental and control group failed to demonstrate statistically significant difference in clinical improvement, but more reduction in probing pocket depth and bone probing depth were observed in the experimental group. The probing pocket depth and the bone probing depth were $2.2{\pm}1.6mm$ and $2.4{\pm}1.1mm$ respectively in the control group, while they were $2.4{\pm}1.3mm$ and $3.0{\pm}1.2mm$ respectively in the experimental group. 3. Radiographic change was not detectable for the both groups during the 6 months of follow up. 4. Sites with deeper probing pocket depth at baseline examination showed greater amount of clinical improvement in both groups. Other clinical factors didn't have any significant effect on the treatment results. It is concluded that though there are some limitations, PLA/PGA membrane is effective for the treatment of mandibular class II furcation involvement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.665-674
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• 2011

This study examined how students' satisfaction with their major department influences their organizational commitment and intention to pursue a career in tourism-related fields among college students majoring in hospitality and tourism. The results indicated that their overall satisfaction with their department affected positively their organizational commitment but not the behavioral intention to pursue career in the tourism-related fields. Organizational commitment, on the other hands, exerted a positively significant influence behavioral intention to pursue tourism-related career. The results of this study underscored the needs for the educators to manage students' psychological attachment to the department they belong to and their major field of study. Continuous relationship-building efforts should be made for the students to pursue tourism-related career after graduation. Such efforts include efficient communication between faculty and students, extended supports from the school and alumni to the students, and last but not the least, sufficient supports from colleges.

• Science of Emotion and Sensibility
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• v.20 no.4
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• pp.89-100
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• 2017

Since smart devices are able to efficiently provide information without barriers of time and location, they are widely utilized with advent of the hyper-connected society. Especially, the smart devices have been developed in the form of wearable devices for mutual interaction between human and objects. Smart clothing, which embeds smart devices within clothes, measures and obtains a variety of bio-signals as it is in close contact with the human bodies. Conventional smart clothing generated wearers' discomfort because they were developed by simple attachment of electronic devices to clothes. Therefore, it is highly recommended to develop novel smart clothing based on smart textiles which integrate electronic devices as parts of textiles. As smart watches are currently the most available wearable devices in the market, smart watch users were selected in this study, for the purpose of investigating core needs of wearable smart device users based on the user experience and user's sensibility. Qualitative research was performed through semi-structured interview in order to obtain detailed answers about user sensibility based on smart watch user experience. After the in-depth interview, the user's sensibility was categorized into four aspects; functional, aesthetic, social, and empirical. Sensibility adjectives and key words were assigned to each aspect and their frequency was analyzed. It was the functional aspect of sensibility that the wearable device users require the most. The results of this study will be utilized as a fundamental data to develop the smart textiles required for the next generation of smart clothing which is attracting as a future wearable device.

• Journal of Dairy Science and Biotechnology
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• v.32 no.2
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• pp.141-145
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• 2014

There is a burgeoning number of products on the market that contain probiotics, but do they do you any good? What exactly are probiotics? They have been defined as living organisms that, when ingested in sufficient quantities, provide health benefits beyond basic nutrition. They are often referred to as "friendly bacteria" or "good bacteria." Probiotics have been claimed, amongst other things, to (i) reduce the incidence of colon cancer and other diseases of the colon, such as IBS, (ii) stimulate the immune system, (iii) have anti-hypertensive and anti-cholesterolemic properties, (iv) mitigate against the effect of antibiotics on the intestinal microbiota, and (v) protect against gastrointestinal infections. However, the scientific basis for many of these claims is not well-established. Indeed, the European Food Safety Authority has denied the use of several health claims associated with probiotics, particularly those related to mitigation of diarrhea following consumption of antibiotics. Thus, there is a need for research on the mechanisms of action of probiotics. We have been mainly interested in the use of probiotics to control enteric infections. There are several possible modes of action to explain how probiotics may protect the host from enteric pathogens, including competitive exclusion and immunomodulation. We have shown that probiotics produce bioactive molecules that interfere with bacterial cell-cell communication (also called quorum sensing), and this results in a down-regulation of virulence genes that are responsible for attachment of the pathogen to the gastrointestinal epithelium. These bioactive molecules act on a variety of bacteria, including enterohemorrhagic and enterotoxigenic Escherichia coli, Salmonella, Clostridium difficile and Clostridium perfringens, and there is evidence that they can inhibit the formation of biofilms by Listeria monocytogenes. These bioactive molecules, which are peptidic in nature, can exert their effects not only in vitro but also in vivo, and we have shown that they mitigate against E. coli O157:H7 and Salmonella in mice and Salmonella and E. coli K88 infections in pigs. They can be delivered in foods such as yoghurt and maintain their activity.

• Journal of Dairy Science and Biotechnology
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• v.35 no.4
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• pp.255-261
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• 2017

The purpose of this study was to investigate the probiotic properties and antioxidant capacity of lactic acid bacteria isolated from Vietnamese feces and the Korean traditional food kimchi. Six isolated strains were identified as Lactobacillus sp. by 16S rRNA sequencing. All strains showed good resistance to low pH (1.5, 2.0, and 3.0) and 0.3% oxgall bile acids. Culture filtrates from the six strains showed various antioxidant effects, including DPPH, ABTS, reducing power, and metal chelating ($Fe^{2+}$) activities. Two of the six Lactobacillus strains showed potential probiotic activity. Heat resistance and adhesion assays were conducted by mixing the selected strains, Lactobacillus acidophilus V4, Lactobacillus plantarum V7, and Lactobacillus paracasei DK121 isolated from kimchi. The results showed that the heat resistance of these strains was similar to that of a commercial strain, L. plantarum LP. In addition, a mucin attachment assay using the mixture of selected strains (V4, V7, and DK121) showed high binding activity to the mucous layer. In conclusion, a mixture of V4, V7, and DK121 shows promising probiotic activity and may be useful for the development of health-related products.

• Journal of Animal Science and Technology
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• v.46 no.5
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• pp.763-772
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• 2004

The patterns of fungal growth and fiber digestion under the microscope, and tile productions of fibrolytic enzyme were studied in an in vitro culture with Neocallimastix frontalis SA when either filter paper or rice straw was provided as sole energy source. Under the microscopic observation, active zoospores attachment, sporangium development and complex rhizoidal system were founded on the surface and at the edge of filter paper. After 7 days of incubation, a reduced fiber mass, a decreased fiber cohesion and a weakened fiber structure by fungal digestion were clearly observed. Similar fungal development was observed with rice straw, but fungal growth and digestion took place mostly on the damaged and exposed portion of rice straw. Although there were some differences in absolute concentration and pattern, the concentration of both cellulase and xylanase increased with incubation time with the higher activity being obtained with filter paper. Their differences were large especially after 48 and 96hr of incubation(P< 0.05). The filter paper was more good inducer of cellulolytic and xylanolytic enzymes compared with complex substrate, rice straw. These findings suggest that the filter paper is the better energy source for N frontalis than the complex substrate, and structural disintegration by physical process is able to help rumen fungal growth on the lignified roughage although anaerobic rumen fungi have mechanical and enzymatic functions for fiber digestion.