• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.366-372
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• 2019

In this paper, we fabricated a capacitive humidity sensor with an IDT(Interdigitated) electrode using commercial polyimide containing fluorine, and its properties were measured and analyzed. First, in order to analyze the composition of commercial polyimide, EDS analysis was performed after patterning process on a silicon wafer. The area of the humidity sensor was $1.56{\times}1.66mm^2$, and the width of the electrode and the gap between the electrodes were $3{\mu}m$ each. The number of electrodes was 166 and the length of the electrode was 1.294mm for the sensitivity of the sensor. The fabricated sensor showed that the sensitivity was 24 fF/%RH, linearity <${\pm}2.5%RH$ and hysteresis <${\pm}4%RH$. As a result of measuring the capacitance value according to the frequency change, the capacitance vlaue decreased with increasing frequency. Capacitance deviations with 10kHz and 100kHz were measured as 0.3pF on average.

• Korean Journal of Construction Engineering and Management
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• v.23 no.1
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• pp.98-105
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• 2022

It is essential for vertical smart farms that artificially grow crops in an enclosed space to properly utilize air environment facilities to create an appropriate growth environment. However, domestic vertical smart farm companies are creating a growing environment by relying on empirical data rather than systematic methods. Using IoT to create a growing environment based on systematic and precise monitoring can increase crop production yield and maximize profitability. This study aims to construct a monitoring system using IoT and to analyze the cause by demonstrating the imbalance of temperature environment, which is a significant factor in crop cultivation. 1) The horizontal temperature distribution of the multi-layer shelf was measured with different operating methods of LED and air conditioner. As a result, there was a temperature difference of "up to 1.7℃" between the sensors. 2) As a result of measuring the vertical temperature distribution, the temperature difference was "up to 6.3℃". In order to reduce this temperature gap, a strategy for proper arrangement and operation of air conditioning equipment is required.

• Korea Trade Review
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• v.41 no.3
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• pp.27-42
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• 2016

This study is to investigate seaport clustering by using meta-frontier and cross-efficiency models. Data covers the 13 Asian ports during 2009, 2010 and 2013 with 3 inputs(depth, total area, and number of cranes) and 1 output(TEU). Correlations coefficient from cross-efficiency matrix are used for measuring clustering dendrogram. After that, meta-frontier analysis for investigating whether the clustering using cross-efficiency method increases the meta-efficiency. Empirical main results are as follows: First, group efficiencies of Busan, Incheon, and Gwangyang ports are increased. Second, meta and group efficiencies of China ports are greater than those of Korean ports. Third, distortion of technology gap of Gwangyang is lower than that of Busan and Incheon. Fourth, Gwangyang, clustering with Ningbo, Chingtao, Tokyo and Caosung ports in 2009 and with Dubai port in 2013 can increase the efficiency. Fifth, to enhance the efficiency, Busan port should be clustered to group 2 in 2010 and group 1 in 2013, and Incheon port clustered to group 2 in 2010 and 2013. Fifth, it is empirically investigated that Busan, Incheon and Gwangyang ports can increase the efficiency by using Cross-efficiency and Meta-frontier models. Port policy planner should promote the clustering policy for Busan with Hong Kong, Shanghai, and Singapore, Incheon and Gwangyang with Chingtao, Nagoya, Ningbo, Tokyo, and Kaoshung ports.

• Journal of Korean Library and Information Science Society
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• v.54 no.2
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• pp.131-154
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• 2023

This study analyzed the effectiveness of visiting reading programs for vulnerable children, focusing on the case of libraries in A-si, Gyeonggi-do. Library A utilized a visiting teacher to deliver books that matched the children's levels and interests through non-face-to-face interactions, or to engage in face-to-face reading sessions and deliver books together. In 2022, a total of 158 individuals from 103 families participated in the program, with 103 individuals from 67 families delivering books and 55 individuals from 36 families engaging in book reading activities. Pre- and post-project surveys were conducted to assess the reading effects, and interviews were conducted with the visiting teachers. The analysis revealed that the level and interest of the children during book delivery and reading sessions were identified, and the effects of reading books with high levels of interaction were significant. Infants who were able to easily acquire reading experiences according to their age exhibited better reading effects compared to elementary school students. The program aimed at the new participant group showed slightly greater effectiveness than the group of continuing participants. Furthermore, following the implementation of the program, improvements were observed in reading interest, reading attitude, reading environment, reading interaction, self-esteem, social skills, language ability, reading proficiency, self-directed learning ability, and library utilization rate.

• The Korean Journal of Franchise Management
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• v.7 no.1
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• pp.31-44
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• 2016

Purpose - This study aims to examine different impacts of franchisor's leadership and franchisee's marketing efforts on franchisee dissatisfaction and switching intentions, and to investigate how franchisee dissatisfaction plays a mediating role in the relationship between these constructs. This study attempted to fill the gap in the literature by treating the franchisee dissatisfaction as a mediator in the relationship between these constructs, identify how franchisor's leadership and franchisee's marketing efforts have effects on franchisee dissatisfaction, in turn, reduce switching intentions, and provide the managerial implications for building a long-term relationship to achieve mutual goals between franchisors and franchisees Research design, data, and methodology - In order to test the hypotheses, the data were collected from franchisees in Seoul and Gyeonggi Province. The franchisee owners were informed about the purpose of this study by the trained interviewers. The respondents received a letter introducing the purpose of this study and another letter that the owners wrote to encourage their active participation. Among the 300 questionnaires distributed, 260 (86.7%) questionnaires were returned. Of those collected questionnaires, 6 uncompleted responses were excluded, and 254 questionnaires with an effective response rate of 84.7% were coded and analyzed using frequency, confirmatory factor analysis, and correlations analysis, and structural equation modeling with SPSS 21.0 and SmartPLS 3.0. Results - The findings of the study are as follows. First, franchisor leadership had a negative effect on franchisee dissatisfaction, but franchisee marketing efforts did not have a significant effect on franchisee dissatisfaction. Second, franchisee dissatisfaction had a positive effect on switching intentions. Third, franchisor leadership had a negative effect on switching intentions, but franchisee marketing efforts did not have a significant effect on switching intentions. Conclusions - This study researched the franchisor's leadership as a single factor of transformational leadership. Thus, it may have limits in measuring leadership. Future studies shall include emotional, loyal, and transactional leadership. In addition, the future studies shall also research the effect of franchisor's leadership and franchisees' marketing efforts on dissatisfaction and switching intentions. For example, the franchisor's relationship-oriented efforts can be a crucial parameter that reduces dissatisfaction and switching intentions.

• Journal of the Korean Society of Radiology
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• v.18 no.2
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• pp.171-177
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• 2024

In this study, two general X-ray device, CT, and MRI inspection devices were selected from general hospitals in the Daejeon area and an experiment was conducted to predict the level of infection by measuring the surface contamination of the inspection devices at different times and to use it as basic data for infection prevention. As a result, the surface contamination level by time zone for general X-ray devices and MRI examination devices was in the order of 13H > 8H > 16H, and for CT examination devices, it was 13H > 16H > 8H, which appeared to be influenced by the number of tests. In addition, the surface contamination results for each part of the test device showed that the highest ATP contamination value was found on the stand bucky handle for the general X-ray device, the headrest for the CT examination device, and the operation switch for the MRI examination device, which was closely related to the number of contacts. As a result of comparing before and after disinfection, all devices showed a significant decrease after disinfection. Based on the results of the experiment, it is believed that it can be used as basic data to identify the level of contamination in radiology laboratories and prevent infectious diseases.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.1
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• pp.15-24
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• 2003

The purpose of this study is to investigate the sterilization effect of Er:YAG laser against the intraoral acid producing bacterium, S. mutans, by irradiating the culture solution containing S. mutans KCTC 3065 with Er:YAG laser having a $650{\mu}m$ diameter beam through the non-contact method. We obtained the following results after examining the temperature changes of the culture solution, numbers of bacterial colonies, and acid-producing ability and attaching ability on teeth by measuring the amount of extracellular polysaccharide produced by S. mutans. The number of bacterial colony was decreased in $10{\mu}l$ culture solution irradiated with laser in overall compared to the control solution. The number decreased as the irradiation intensity and pulse repetition rate were larger and as the exposure time was increased. However, it did not change significantly in $100{\mu}l$ culture solution compared to the control solution. Although the acid-producing ability of S. mutans was inhibited for a certain duration after laser irradiation in 10r1 bacterial culture solution, it did not change in $100{\mu}m$ solution compared with the control solution. The amount of extracellular polysaccharide synthesized by S. mutans was partially decreased through laser irradiation in $10{\mu}m$ culture solution but did not change in $100{\mu}m$ culture solution. Based on these findings, we concluded that Er:YAG laser has an sterilization effect on S. mutans in which we presume that the mechanism is through the heat effect rather than the mechanical effect from development of ultrasound.

• Journal of Korean Orthopaedic Sports Medicine
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• v.3 no.1
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• pp.60-65
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• 2004

Purpose: The purpose of this study was to evaluate the results of limited vastus lateralis release for treatment of painful bipartite patella. Materials and Methods: From Jan. 1995 to Jun. 2002, we performed limited lateral retinacular release in 14 patients(16 cases) for treatment of painful bipartite patella. All patients were men and mean age was 22.3 years old. The opeative techique was that insertion of the vastus lateralis to the painful patellar fragment is detached subperiosteally. We evaluated the clinical results by degree of pain and level of activity. Also we analyzed the radiologic findings by measuring fragment tilting angle and gap between fragments. The mean follow up period was 14 months. Results: At final follow up, all of the patients showed pain relief and can be returned to more than recreational sports activity after the operation. On radiologic findings, fragment tilting angle and gap between fragments were reduced at statistically significant level. Conclusion: The limited lateral retinacular release for treatment of painful bipartite patella is one of good methods which is less invasive and shows good results in clinical and radiologic findings.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.4
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• pp.271-278
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• 2012

Purpose: Recently implant surgical guides were used for accurate and atraumatic operation. In this study, the accuracy of two different types of surgical guides, positioning device fabricated and stereolithography fabricated surgical guides, were evaluated in four different types of tooth loss models. Materials and methods: Surgical guides were fabricated with stereolithography and positioning device respectively. Implants were placed on 40 models using the two different types of surgical guides. The fitness of the surgical guides was evaluated by measuring the gap between the surgical guide and the model. The accuracy of surgical guide was evaluated on a pre- and post-surgical CT image fusion. Results: The gap between the surgical guide and the model was $1.4{\pm}0.3mm$ and $0.4{\pm}0.3mm$ for the stereolithography and positioning device surgical guide, respectively. The stereolithography showed mesiodistal angular deviation of $3.9{\pm}1.6^{\circ}$, buccolingual angular deviation of $2.7{\pm}1.5^{\circ}$ and vertical deviation of $1.9{\pm}0.9mm$, whereas the positioning device showed mesiodistal angular deviation of $0.7{\pm}0.3^{\circ}$, buccolingual angular deviation of $0.3{\pm}0.2^{\circ}$ and vertical deviation of $0.4{\pm}0.2mm$. The differences were statistically significant between the two groups (P<.05). Conclusion: The laboratory fabricated surgical guides using a positioning device allow implant placement more accurately than the stereolithography surgical guides in dental clinic.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.1
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• pp.48-54
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• 2010

Purpose: The objective of this study was to evaluate and compare the accuracy of impression body taking by the closed and the open tray impression technique with 3 types of impression tray. Individual tray, metal stock tray and polycarbonate tray were used. Materials and methods: Nine closed tray impressions were taken by individual tray, metal stock tray and polycarbonate stock tray, respectively with polyether impression material. 9 open tray impressions were also acquired by same manner. Precision analysis on the master models was performed by attaching the reference frameworks with alternate single screws and measuring the vertical fit discrepancy of respective analogues in working cast with a stereo microscope. Data were analyzed by 1 way ANOVA and independent t-test. Results: The average fit accuracy of impression bodies was calculated. With the closed tray impression technique, there were significant statistical differences in vertical fit discrepancy according to the types of tray. The individual tray group showed the lowest value and the polycarbonate stock tray group represented the highest. With the open tray impression technique, there was no significant difference in vertical fit discrepancy. Significant statistical difference in vertical fit discrepancy was found between the open and the closed impression technique with the polycarbonate stock tray. Conclusion: From the results above, more precise impressions could be acquired by the rigid individual tray compared with the polycarbonate stock tray. It was hard to get consistent accuracy impressions by the closed tray impression technique with polycarbonate stock trays.