• Journal of Digital Contents Society
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• v.19 no.4
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• pp.837-844
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• 2018

Recently, the cloud technology has made dynamical network changes by enabling the construction of a logical network without building a physical network. Despite recent research on the cloud, it is necessary to study security functions for the identification of fake virtual network functions and the encryption of communication between entities. Because the VNFs are open to subscribers and able to implement service directly, which can make them an attack target. In this paper, we propose a virtual public key infrastructure mechanism that detects a fake VNFs and guarantees data security through mutual authentication between VNFs. To evaluate the virtual PKI, we built a management and orchestration environment to test the performance of authentication and key generation for data security. And we test the detection of a distributed denial of service by using several AI algorithms to enhance the security in NFV.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.397-397
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• 2016

Triboelectric nanogenerators (TENG) can produce power from ambient mechanical sources and have strong points of high output performance, light weight, low cost, and easy manufacturing process. It is expected that TENG can be utilized in the fields of wireless electronics and self-powered devices in the world which pays attention to healthcare and the IoT. In this work, we focus on scavenging ambient rotational energy by using a durably designed TENG. In previous studies regarding harvesting rotation mode energy, the devices were based on sliding mechanism and durability was not considered as a major issue. However friction by rotation causes reliability problems due to wear and tear. Therefore, in this study, we convert rotary motion to linear motion utilizing a cam by which we can then utilize contact-mode TENG and improve device reliability. In order to increase output performance, bumper springs were used below the TENG and the optimum value for the bumper spring constant was analyzed theoretically. Furthermore, the inserting a soft substrate was proposed and its effect on high output was determined to be due to an increase in the contact area. By increasing the number of cam noses, the output frequency was shown to increase linearly. For the purpose of maximum power transfer, the input impedance of the device was determined. Finally, to demonstrate the use of the C-TENG as a direct power source, it was installed on a commercial bicycle wheel and connected to 180 LEDs. In conclusion we present a rotational motion TENG energy scavenger system designed for enhanced durability and optimized output by appropriate choice of spring constants and substrate.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.534-539
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• 2008

This paper is about intelligent hexapod robot for the support walking of the aged person. The robot using various sensors and small camera has various abilities of forward backward walking, turing left or right, control the speed of walking, avoiding the obstacles and detecting risky situation of fire or gas. To let the aged feel soft and safe walking, we used special servo motor and developed hexapod walking mechanism and effective algorithm.

• Journal of Dental Rehabilitation and Applied Science
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• v.20 no.1
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• pp.31-41
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• 2004

The osseointegration in implant therapy is achieved following general wound healing mechanism. Platelet play a major role in wound healing process. In addition to blood clot formation, they secrete many growth factors which regulate the attachment, proliferation and differentiation of nearly all cell types. The use of these growth factors is now known to be very effective methods to improve the cellular activity. Platelet-rich plasma which is made with the newly developed technique concentrating platelets 3-folds or more is also proven to be very effective method to stimulate and accelerate the healing of bone and soft tissue. Previous study proved that platelet-rich plasma enhanced the cellular attachment by inducing fibronectin, vitronectin from osteoblast. So, this study was aimed to investigate the effect of platelet-rich plasma on the cellular proliferation and differentiation in vitro. The effect on the proliferation was evaluated by MTT assay. To evaluate autocrine and paracrine effect, conditioned medium was made and compared. By measuring alkaline phosphatase activity, the effect on the cellular differentiation was evaluated. The results were as following: The cellular proliferation of osteoblast cell line increased depending on the concentration of platelet-rich plasma and conditioned medium. The alkaline phosphatase activity increased depending on the concentration of platelet-rich plasma and conditioned medium. These findings imply that platelet-rich plasma enhance the cellular proliferation and differentiation and maximize the cellular activity by using the autocrine and paracrine effect.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2003.09a
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• pp.75-75
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• 2003

Purpose: To investigate whether or not acupuncture of GB34 produces a significant response of the modulation of somatomotor areas by functional magnetic resonance imaging (fMRI) study. Methods: The acupoint, GB34, located in the back of the knee, is known to be effective in recovering motor function after stroke. Using 3T MRI scanner, functional MR imaging of the whole brain was performed in 12 normal healthy subjects during two stimulation paradigms; acupuncture manipulation on GB 34 and sham points. This study investigates the activation of the motor cortex elicited by a soft and an intensified stimulation of GB 34. Three different paradigms were carried out to detect any possible modulation of the Blood Oxygenation Level Dependent (BOLD) response in the somatomortor area to motor stimulation through acupuncture. Results: Group analysis from seven individuals showed that bilateral sensorimotor areas (BA 3,4,6 and 7) showed stimulation related BOLD signal contrast of approximately 6% whereas very few areas were activated when sham stimulation is given. Conclusions: The present study shows that acupuncture fMRI study can be safely conducted in 3T MRI environment, and acupuncture stimulation in GB34 modulates the cortical activities of the soma- to motor area in human. The present findings may shed light on the CNS mechanism of motor function by acupuncture and form a basis for future investigations of motor modulation circuits in the stroke patients. Acknowledgement: This study was supported by a grant of the Mid and Long Term Nuclear RID Plan Program, Ministry of Science and Technology, Republic of Korea.

• Journal of Animal Science and Technology
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• v.59 no.5
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• pp.12.1-12.7
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• 2017

Background: Despite the widespread use of dexamethasone in veterinary and human medicine, it is reported to cause some severe pregnancy related side effects like abortion in some animals. The mechanism of the response is not clear but seems to be related to interspecies and/or breed difference in response which may involve alterations in the concentrations of some reproductive hormones. Methods: Twenty Sahel goats comprising 18 does and 2 bucks were used for this study. Pregnancies were achieved by natural mating after synchronization. Repeated dexamethasone injections were given at 0.25 mg/kg body weight. Blood samples were collected biweekly for hormonal assay. Uterine biopsies were harvested at days 28 and day 78 of gestation through caesarean section for immunohistochemical analysis using 3 pregnant does randomly selected from each group at each instant. Data were expressed as Means ${\pm}$ Standard Deviations and analyzed using statistical soft ware package, GraphPad Instant, version 3.0 (2003) and progesterone receptor (PR) were scored semi-quantitatively. Results: Dexamethasone treatments had no significant (p > 0.05) effect on progesterone and estrogen concentrations in pregnant Sahel goats but up regulated PR from 2+ to 3+ in second trimester. Conclusion: As dexamethasone adverse effect on placenta is an established fact, the lack of effect on progesterone level in this study may be due to the fact that unlike other species whose progesterone production during pregnancy is placenta - dependent, in goats is corpus luteum - dependent. Consequently dexamethasone adverse effect on placenta reported in literatures did not influence progesterone levels during pregnancy in Sahel goat. The up regulation of progesterone receptor (PR) in Sahel goat gravid uterus is a beneficial effects and that dexamethasone can safely be used in corpus luteum - dependent progesterone secreting pregnant animal species like Sahel goat and camel. Therefore source of progesterone secretions during pregnancy should be considered in clinical application of dexamethasone in pregnancy.

• Archives of Plastic Surgery
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• v.34 no.6
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• pp.671-678
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• 2007

Purpose: Venous malformation(VM) which often causes pain and discomfort is the most common type of vascular malformations. Although it is presented with disfigured appearance and associated soft tissue or skeletal hypertrophy, the molecular bases of VMs are poorly understood. Differentially expressed genes(DEGs) of VMs were investigated to illuminate the molecular mechanism of the disease entity. Methods: Gene expressions of VM patients' subcutaneous tissue were studied in comparison with normal persons' by $GeneFishing^{TM}$ technique using the annealing control primers (ACPs) to identify DEGs. Candidate genes were sequenced and screened by basic local alignment search tool (BLAST) afterwards. Results: Among seventy DEGs identified, forty DEGs which had shown significantly different expression pattern were sequenced. Twenty eight out of 40 were up-regulated while 12 were down-regulated. BLAST searches revealed that 37 were known genes and 3 were unknown genes. Many genes were involved in the differentiation and remodeling of smooth muscle cells, opposed to the previous hypothesis that a lot of angiogenetic genes would be involved. Furthermore, several transcription factors and related genes, as well as cell signaling and metabolism regulators, were up regulated. Conclusion: It suggests that analysis of DEGs in VMs provide basic knowledge about its pathophysiology. and new therapeutic approaches.

• The Journal of the Korean dental association
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• v.49 no.4
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• pp.219-226
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• 2011

Snoring and obstructive sleep apnea (OSA) are common sleep disordered breathing conditions. Habitual snoring is caused by a vibration of soft tissue of upper airway while breath in sleeping, and obstructive sleep apnea is caused by the repeated obstructions of airflow for a sleeping, specially airflow of pharynx. Researchers have shown that snoring is the most important symptom connected with the obstructive sleep apnea syndrome The treatment is directed toward improving the air flow by various surgical and nonsurgical methods. The current surgical procedures used are uvulopalatopharyngoplasty(UPPP), orthognathic surgery, nasal cavity surgery. Among the nonsurgical methods there are nasal continuous positive air pressure(CPAP), pharmacologic therapy. weight loss in obese patient, oral appliance(sleep splint). Sleep splint brings the mandible forward in order to increase upper airway volume and prevents total upper airway collapse during sleep. However, the precise mechanism of action is not yet completely understood, especially aerodynamic factor. The aim of this study evaluated the effect of conservative treatment of snoring and OSAS by sleep splint through measured aerodynamic change by an aerophone II. We measured a airflow, sound pressure level, duration, mean power from overall airflow by aerophone II mask. The results indicated that on a positive correlation between a decrease in maximum airflow rate and a decrease in maximum sound pressure level, on a negative correlation between a decrease in maximum airflow rate and a increase in duration.

• Korean Journal of Environmental Biology
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• v.18 no.1
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• pp.145-151
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• 2000

The mouthparts of the Apionidae are almost of the same structures as in the Curculionidae feeding soft plant tissues, and two subfamilies in the current system are well supported by their structures. The subfamilies Apioninae and Nanophyinae are clearly characterized as follows. In Apioninae, clypeal margin sinuate; mandibles meet anteropo-steriorly when retracted and more or less curved internally; maxillary palpi two-segmented, with large palpiger; labial palpi one-segmented; prementum parallel-sided, longer than wide. In Nanophyinae, clypeal margin with two to three notches in the middle; mandibles meet anteroposteriorly when retracted and more or less curved internally; maxillary palpi three-segmented, palpiger about as great as stipes; labial palpi two-segmented, separated to each other by the apical protrusion of prementum; prementum about as long as wide. [Insecta, Coleoptera, Comparative morphology, Mouthparts, Apionidae].

• The Journal of the Korean bone and joint tumor society
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• v.9 no.1
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• pp.77-83
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• 2003

Aggressive fibromatosis is a rare soft tissue tumor with locally invasive and infiltrative characteristics. The mechanism of this invasive nature was not reported until now. Mutations or reduction of PTEN, tumor suppressor gene, in cancer tissues, have been found to be associated with invasiveness and metastatic properties of cancer cells. To know the pattern of expression of PTEN in aggressive fibromatosis, we analysed the expression of PTEN with immunohistochemical stain and immunoblotting. PTEN was homogeneously expressed in the normal musculoaponeurotic tissues, but absent or very faint in tissues of patients with aggressive fibromatosis as evidenced by western blot analysis and immunohistochemical examinations. Although the meaning of decreased PTEN expression in aggressive fibromatosis is not certain, it might be involved in the growth of the aggressive fibromatosis, and associated with phenotype of aggressive fibromatosis.