• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.6
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• pp.510-522
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• 2005

To assess the clinical applicability of bio-artificial mucosa which was made with autologous oral keratinocytes and human acellular dermal matrix, the formation of basement membrane and stratification of oral keratinocytes were evaluated. Six New Zealand white rabbits (around 2kg in weight) were anesthetized and its buccal mucosa was harvested (1.0 $\times$ 0.5cm size). Oral keratinicytes were extracted and cultured primarily with the feeder layer of pretreated NIH J2 3T3 fibroblast. These confluent cells were innoculated on the human acellular dermal matrix and cultured in multiple layer by air-rafting method. After 3, 5, 7, 10, 14 days of culture, each cultured bio-artificial mucosa was investigated the number of epthelial layer of by H&E stain and toluidine blue stain. The immuhohistochemical methods were used to evaluate the cell division capacity, the formation of basement membrane, and it's property of specific cells (PCNA, cytokeratin 14, laminin). Transmission electromicroscopy was used for the attachment between cells and matrix with the number of hemidesmosome. In result, the numbers of layer of stratified growth of oral keratinocyte cultured on the human acellular dermal matrix and the number of hemidesomal attachment between epithelial cells and human acellular dermal matrix were similar to the layers of normal oral mucosa after 10 days of culture. The cell division rate, basement membrane formation and proliferation rate increased as culture period increased. With these results, bio-artificial mucosa with autologous oral epithelial cells cultured on the acellular dermal matrix had clinically adaptable properties after 10 days' culture and this new bio-artificial mucosa model with relatively short culture time can be expected clinical applicability.

• Applied Microscopy
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• v.28 no.2
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• pp.171-180
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• 1998

In the present study, the vacuolar apparatus were investigated in the hepatocytes of rats treated with DA by transmission electron microscopy of conventional and cytochemical thin sections. In the rats after 20 min of dehydrocholic acid treatment, the cis Golgj cisterns were sacculated in line. The saccule occasionally occured by elongation and attenuated neck. The lysosomes also showed protrudent saccule. The vesicles were observed near the cis Golgi cisterns, lysosome and bile canaliculi. Some of the vesicles appeared to be fused to bile canaliculi. The cis Golgi cisterns usually faced toward the bile canaliculi both in normal and experimental groups. The cis Golgi cisterns, protrudent saccule and vesicles were almost devoid of visible contents. The osmium deposits were heavy on the protrudent saccule as well as on the cis Golgi cisterns or on the vesicles isolated near by, but they were light or not observed on the vesicles in the immediate vicinity of bile canaliculi. The acid phosphatase activities appeared on the lysosome and vesicles located near by, but did not appear on the vesicles as approaching closer to the bile canaliculi. The evidence suggests that the vesicles are derived from the cis Gogi cistern and lysosomes and fuse to bile canaliculi for exocytosis, and that the activity in the vesicles is diminished as approaching closer to the bile canaliculi.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.506-510
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• 2004

A torque transmission system composed of several gears and couplings is flexible. In order to get an exact response of motor, the torsional vibration due to an unexpected change of motor speed must be suppressed. Therefore, it is very important that motor control suppress vibration. Various methods to control it including dual inertia system are proposed. Specially, the method of vibration suppression is that vibration can be suppressed to fee㏈ack the estimated torsion torque via the disturbance observer filter being of normal filter. The suitable Proportional controller and coefficient parameter can be designed using CDM and the torsional vibration also be suppressed, but it has a low degree of adaptability to disturbance. The PID controller can be designed easily, but makes the excessive overshoot and oscillation for system response in the early period. To resolve these problems, simple and practical PID controller with two degree of freedom is proposed recently that it ran improve performance of obeying the reference unconcerned in any disturbance by changing the proportional gain by two degree of freedom parameter. But it has also the defect that parameter a must be changed to obtain the ideal Proportional parameter. On this paper, we design the controller which automatically adjusts parameter u using fuzzy Algorithm to overcome such defects. Also, we compare the proposed method with established one and evaluate them to confirm performance of the designed controller.

• Parasites, Hosts and Diseases
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• v.36 no.1
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• pp.7-14
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• 1998

In order to understand the action mechanism of polyhexamethylene biguanide (PHMB) to the cyst of Accnthcnloebc on the morphological basis, the cysts of four corneal isolates of Acanthanoebc were treated with minimal cysticidal concentration (MCC) of PHMB and their ultrastructural changes were examined by transmission electron microscopy. The most striking change of cysts treated with PHMB compared with normal cysts was the shrinkage of intracystic amoebae, which resulted in the separation of the plasma membrane of intracystic amoeba from endocystic wall. Subplasmalemmal lipid droplets became irregularly shaped . In severely damaged cysts, cytoplasm was aggregated and organelles were severely deformed. Cytoplasmic materials were leaked out through the damaged plasma membrane. Most cysts showed aggregation of nuclear chromatin material. Number of mitochondrial cristae was also reduced. Ecto- and endo-cystic walls were relatively well tolerated. Findings in the present study revealed that PHMB affected mainly on plasma membrane, but lesser on organellar membrane of intracystic amoeba. It seemed likely that PHMB might kill cystic forms of Accnthamoebc by similar mechanism in which this environmental biocide can damage the cell wall of Escherichia coli by binding with acidic phospholipids.

• Journal of Korea Multimedia Society
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• v.5 no.4
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• pp.458-467
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• 2002

There has been proposed many simplification algorithms for effectively decreasing large-volumed polygonal surface data. These algorithms apply their own cost function for collapse to one of fundamental simplification unit, such as vertex, edge and triangle, and minimize the simplification error occurred in each simplification steps. Most of cost functions adopted in existing works use the error estimation method based on distance optimization. Unfortunately, it is hard to define the local characteristics of surface data using distance factor alone, which is basically scalar component. Therefore, the algorithms cannot preserve the characteristic features in surface areas with high curvature and, consequently, loss the detailed shape of original mesh in high simplification ratio. In this paper, we consider the vector component, such as surface orientation, as one of factors for cost function. The surface orientation is independent upon scalar component, distance value. This means that we can reconsider whether or not to preserve them as the amount of vector component, although they are elements with low scalar values. In addition, we develop a simplification algorithm based on half-edge collapse manner, which use the proposed cost function as the criterion for removing elements. In half-edge collapse, using one of endpoints in the edge represents a new vertex after collapse operation. The approach is memory efficient and effectively applicable to the rendering system requiring real-time transmission of large-volumed surface data.

• Journal of IKEEE
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• v.23 no.2
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• pp.743-746
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• 2019

In this paper we proposed a new ocean radiation automatic monitoring system. The proposed system has the following characteristics: First, using NaI + PVT mixed detectors, the response speed is fast and precision analysis is possible. Second, the application of temperature compensation algorithm to scintillator-type sensors does not require additional cooling devices and enables stable operation in the changing ocean environment. Third, since cooling system is not needed, electricity consumption is low, and electricity can be supplied reliably by utilizing solar energy, which can be installed at the observation deck of ocean environment. Fourth, using GPS and wireless communications, accurate location information and real-time data transmission function for measurement areas enables immediate warning response in the event of nuclear accidents such as those involving neighboring countries. The results tested by the authorized testing agency to assess the performance of the proposed system were measured in the range of $5{\mu}Sv/h$ to 15mSv/h, which is the highest level in the world, and the accuracy was determined to be ${\pm}8.1%$, making normal operation below the international standard ${\pm}15%$. The internal environmental grade (waterproof) was achieved, and the rate of variation was measured within 5% at operating temperature of $-20^{\circ}C$ to $50^{\circ}C$ and stability was verified. Since the measured value change rate was measured within 10% after the vibration test, it was confirmed that there will be no change in the measured value due to vibration in the ocean environment caused by waves.

• Journal of the Korean Applied Science and Technology
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• v.38 no.1
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• pp.48-59
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• 2021

This study aimed to explore anxiety, risk perception, information literacy, and performance level of infection prevention practices against coronavirus disease (COVID-19) among nursing students during the pandemic. A descriptive online survey was conducted, targeting a total of 224 nursing students from June 8, 2020 to 14, 2020. The collected data were analyzed using descriptive statistics, t-test, analysis of variance, and correlation analysis using SPSS 26.0. The nursing students' level of anxiety was 6.86 out of 10, which was normal. Their information literacy level and performance level of infection prevention practices were 3.50 out of 4 and 4.44 out of 5, respectively, and these scores were considered high. The higher the level of anxiety, risk perception, and information literacy, the higher the level of infection prevention practices. The level of anxiety with respect to infection and risk perception may increase when new types of infectious diseases such as COVID-19 break out. Therefore, it is necessary to promote the accurate understanding of the infectious diseases by providing sufficient information. Accurate understanding of new infectious diseases can reduce the risk of transmission as it encourages people to thoroughly perform infection prevention practices.

• Journal of IKEEE
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• v.26 no.3
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• pp.510-514
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• 2022

In this paper, we propose the development of high-sensitivity low-end radiation measuring sensor module. The proposed measurement sensor module is a scintillator + photomultiplier(SiPM) sensor optimization structure design, amplification and filter and control circuit design for sensor driver, control circuit design including short-distance communication, sensor mechanism design and manufacturing, and GUI development applied to prototypes consists of, etc. The scintillator + photomultiplier(SiPM) sensor optimization structure design is designed by checking the characteristics of the scintillator and the photomultiplier (SiPM) for the sensor structure design. Amplification, filter and control circuit design for sensor driver is designed to process fine scintillation signal generated by radiation with a scintillator using SiPM. Control circuit design including short-distance communication is designed to enable data transmission through MCU design to support short-range wireless communication function and wired communication support. The sensor mechanism design and manufacture is designed so that the glare generated by wrapping a reflective paper (mirroring) on the outside of the plastic scintillator is reflected to increase the efficiency in order to transmit the fine scintillation signal generated from the plastic scintillator to the photomultiplier(SiPM). The GUI development applied to the prototype expresses the date and time at the top according to each screen and allows the measurement unit and time, seconds, alarm level, communication status, battery capacity, etc. to be expressed. In order to evaluate the performance of the proposed system, the results of experiments conducted by an authorized testing institute showed that the radiation dose measurement range was 30 𝜇Sv/h ~ 10 mSv/h, so the results are the same as the highest level among products sold commercially at domestic and foreign. In addition, it was confirmed that the measurement uncertainty of ±7.4% was measured, and normal operation was performed under the international standard ±15%.

• Pediatric Infection and Vaccine
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• v.29 no.3
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• pp.141-146
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• 2022

Purpose: Congenital tuberculosis (TB) is difficult to diagnose owing to its non-specific symptoms. Delayed diagnosis increases the risk of nosocomial infections. We examined the TB status of infants and healthcare workers who were in proximity to preterm twins diagnosed with congenital TB 63 days after birth and 48 days after admission to the neonatal intensive care unit (NICU). Methods: Contact investigations were conducted on 24 staff members and 35 infants who had contact with the twins with congenital TB. Results: Two of the exposed infants, both of whom had received the Bacille Calmette-Guérin vaccine, had positive tuberculin skin test results. Four of the 24 exposed staff members had positive interferon-gamma release assay (IGRA) test results before exposure and were not re-tested after exposure; the remaining 20 had negative IGRA test results. All exposed staff members and infants had normal chest radiographic findings. Conclusions: Although transmission of TB in the NICU is unusual, it can occur. These results support the need for a systematic investigation of the TB status of exposed infants, their family members, and healthcare workers.

• Journal of Food Hygiene and Safety
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• v.39 no.3
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• pp.181-190
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• 2024

Bovine mastitis-associated Escherichia coli (BMEC) is considered the main causative agent of significant financial losses in the dairy industry worldwide, as it alters both the quantity and quality of milk produced and increases the rate of culling. This creates a variety of challenges for researchers, veterinarians, and farmers in understanding and determining the most effective therapies and diagnostic techniques. Subclinical mastitis is particularly concerning, as infected bovines exhibit no obvious symptoms and continue to secrete apparently normal milk over an extended period, allowing the causative pathogen, E. coli, to spread within the herd. For effective prevention, understanding the pathogenesis of mastitis through three stages invasion, infection, and inflammation is essential. To date, no clear correlation has been found between virulence factors and pathogenicity contributing to the clinical severity of BMEC. Multidrug-resistant E. coli and the evolution of novel resistance mechanisms have become concerns owing to the extensive use of antibiotics to treat mastitis. Therefore, it is vital to explore alternative controls to enhance the efficacy of BMEC treatment. Over the past 30 years, various genetic typing techniques have been used to examine the subspecies-level epidemiology of bovine mastitis. These studies have advanced our understanding of the origin, transmission pathway, population structure, and evolutionary relatedness of BMEC strains. In this review we provide an overview of BMEC, including insights into its etiology, genetic relationship, pathogenesis, and management of the disease, as well as new therapy options.