• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.12
• /
• pp.6047-6052
• /
• 2013

A cosmetic manufacturing process requires a mold that is inevitable for mass production. Cosmetic containers are one of major factors affecting the customer's purchase decision. In addition, the manufacturing cost in cosmetic container comprises a large portion of the entire product cost. Therefore, a mold satisfying the economical feasibility, aesthetics and functionality is necessary. Among the cosmetic containers, square shape containers have a tendency of having a short shot defect product. The square shaped cosmetic containers are mostly produced as a side gate shape on the two-plate molds. On the other hand, there are two disadvantages, such as gate trace and post processing requirement. The overlap-gateproposed in this study has the characteristics of intaglio gate cutting and no need for post processing. The delivery system of the overlap gate was simulated and compared with the side gate via Moldflow. The improvement in flow, frozen rate, density, and Air trap was confirmed. Based on the simulation results, the mold and performed injection molding was fabricated. In this study, the possibility of the mass production of high aesthetic and functionality cosmetic containers was verified.

• Archives of Plastic Surgery
• /
• v.38 no.4
• /
• pp.359-368
• /
• 2011

Purpose: Aquacel Ag$^{(R)}$ is a hydrofiber wound dressing integrated with ionic silver. Sorbact$^{(R)}$ is a hydrophobiccoated dressing that uses the hydrophobic interaction with microbes. In this study, we compared the wound healing effects and the antibacterial effects of Medifoam$^{(R)}$, Betadine soaked, Aquacel Ag$^{(R)}$ and Sorbact$^{(R)}$ dressings against MRSA-infected wounds. Methods: Eighty rats were divided into four groups: Medifoam$^{(R)}$; Betadine soaked; Aquacel Ag$^{(R)}$; and Sorbact$^{(R)}$. A $1.5{\times}1.5cm$ square full-thickness wound was made on the dorsum of each rat and infected with MRSA. Twenty-four hours thereafter, each dressing was applied to the wound and changed every other day. One, 3, 7, 11 and 15 days after the wound infection, swab culture grade, wound bed appearance score, and wound defect size change were evaluated, and 7 and 15 days after, histologic evaluation was compared between the groups. Results: The bacteria load of wounds in the Sorbact$^{(R)}$ group decreased earlier than in the other groups. The wound bed appearance score of the Sorbact$^{(R)}$ group also increased quicker, compared with the other groups. However, the size of wounds of the Aquacel Ag$^{(R)}$ group decreased more rapidly, compared with other groups. From the histologic point of view, there was no significant difference between Betadine soaked, Aquacel Ag$^{(R)}$ and Sorbact groups. Conclusion: The hydrophobic dressing using Sorbact$^{(R)}$ showed a more rapid reduction in the MRSA load and an elevation in the wound bed appearance score, but a slower decrease in wound size change due to detachment of wound bed tissue when the dressing was eliminated in the low exudate wound. The silver-containing hydrofiber dressing using Aquacel Ag$^{(R)}$ was more effective in ultimate wound size reduction, but some debris was trapped in the wound tissue and induced foreign body reaction in the high exudate wound. Thus, ongoing selection process of treatment based on the evaluation of the infectious wound state will be very important.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.24 no.3
• /
• pp.271-279
• /
• 2006

Acoustic Emission (AE) technology is an effective nondestructive testing for continuous monitoring of defect formation and failures in structural materials. This paper presents a source location model using Acoustic Emission (AE) sensors in a Pre-Stressed Concrete (PSC) beam and the evaluation of the model was performed through lab experiments. 54 AE events were made on the surface of the 5m-PSC beam using a Schmidt Hammer and arrival times were measured with 7AE sensors. The source location f3r each event was estimated using least squares. The results were compared with actual positions and the RMSE (Root Mean Square Errors) was about 2cm.

• Journal of the Optical Society of Korea
• /
• v.14 no.2
• /
• pp.163-169
• /
• 2010

Novel wafer-level fabrication of a glass ball-lens is realized for optoelectronic applications. A Pyrex wafer is bonded to a silicon wafer and cross-cut into a square-tile pattern, followed by wet-etching of the underlying silicon. Cubes of Pyrex on the undercut silicon are then turned into ball shapes by thermal reflow, and separated from the wafer by further etching of the silicon support. Radial variation and surface roughness are measured to be less than ${\pm}3\;{\mu}m$ and ${\pm}1\;nm$, respectively, for ball diameter of about $500\;{\mu}m$. A surface defect on the ball that is due to the silicon support is shown to be healed by using a silicon-optical-bench. Optical power-relay of the ball lens showed the maximum efficiency of 65% between two single-mode fibers on the silicon-optical-bench.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.19 no.2
• /
• pp.162-168
• /
• 2006

Recently, diagnosis techniques have been investigated to detect a Partial Discharge associated with a dielectric material defect in a high voltage electrical apparatus, However, the properties of detection technique of Partial Discharge aren't completely understood because the physical process of Partial Discharge. Therefore, this paper analyzes the process on surface discharge of polymer insulator using wavelet transform. Wavelet transform provides a direct quantitative measure of spectral content in the time~frequency domain. As it is important to develop a non-contact method for detecting the kaolin contamination degree, this research analyzes the electromagnetic waves emitted from Partial Discharge using wavelet transform. This result experimentally shows the process of Partial Discharge as a two-dimensional distribution in the time-frequency domain. Feature extraction parameter namely, maximum and average of wavelet coefficients values, wavelet coefficients value at the point of $95\%$ in a histogram and number of maximum wavelet coefficient have used electromagnetic wave signals as input signals in the preprocessing process of neural networks in order to identify kaolin contamination rates. As result, root sum square error was produced by the test with a learning of neural networks obtained 0.00828.

• Journal of Welding and Joining
• /
• v.29 no.3
• /
• pp.82-88
• /
• 2011

With a tendency for the application of thin magnesium alloy plates in portable electronic equipment such as cell phone and notebook PC, there is a requirement to develop a welding technology for the lap welding of these thin magnesium alloy. This paper presents the single pulsed laser welding of AZ31B magnesium alloy. The effects of fiber types and parameters such as peak power and pulse width on laser weldability were investigated. The results show that weld defects, especially solidification crack, were always generated in the weld. These defects couldn't be controlled by the simple square pulse, but could be improved through the application of variable pulse. It is because that variable pulse has effect of solidification delay by dropping peak power gradually.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.18 no.2
• /
• pp.180-186
• /
• 2005

As a driving method of AC-PDP, Address-Display Separated(ADS) driving has been widely adopted for its simple architecture and low discharge failure rate. However, a high definition like a HDTV has defect of long addressing time by reason of a number of pixels. Priming effect isn't fully sustained because of long addressing time during the address period. Therefore, it has different wall charge and luminance of each addressing time in the sustain period. In this study, we suggest a new driving waveform on the address period to improve these defects. We applied a ramp waveform, instead of a square waveform, to an address period in ADS, for operating on the AC-PDP, which used the conventional gas [He-Ne-Xe]. When the ramp waveform is applied to the address period, we experimented for uniform wall charge and the improved luminance by sustained Priming effect at each addressing time in the sustain period.

• Smart Structures and Systems
• /
• v.17 no.1
• /
• pp.31-43
• /
• 2016

Applications of ultrasonic tomography to concrete structures have been reported for many years. However, practical and effective application of this tool for nondestructive assessment of internal concrete condition is hampered by time consuming transducer coupling that limits the amount of ultrasonic data that can be collected. This research aims to deploy recent developments in air-coupled ultrasonic measurements of solids, described in Part 1 of this paper set, to concrete in order to image internal inclusions. Ultrasonic signals are collected from concrete samples using a fully air-coupled (contactless) test configuration. These air coupled data are compared to those collected using partial semi-contact and full-contact test configurations. Two samples are considered: a 150 mm diameter cylinder with an internal circular void and a prism with $300mm{\times}300mm$ square cross-section that contains internal damaged regions and embedded reinforcement. The heterogeneous nature of concrete material structure complicates the application and interpretation of ultrasonic measurements and imaging. Volumetric inclusions within the concrete specimens are identified in the constructed velocity tomograms, but wave scattering at internal interfaces of the concrete disrupts the images. This disruption reduces defect detection accuracy as compared with tomograms built up of data collected from homogeneous solid samples (PVC) that are described in Part 1 of this paper set. Semi-contact measurements provide some improvement in accuracy through higher signal-to-noise ratio while still allowing for reasonably rapid data collection.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.36 no.6
• /
• pp.515-519
• /
• 2010

Introduction: Bone defects in the jaw are frequently observed after odontogenic cyst enucleation. The success of bone healing appears to be related to the size of the bone defect, the anatomical location, the patient's age and other parameters. The use of bone grafting material is dependent on the operator's preference. No evidence-based definite treatment protocol has been established. This study evaluated the effect of a bone graft into the defect after odontogenic cyst enucleation. Materials and Methods: A total of 55 patients, who had been treated for an odontogenic cyst with cyst enucleation from 2000 to 2009 at the department of Oral and Maxillofacial Surgery, Samsung Medical Center, were included in this study. Patients who were followed-up for more than 1 year were included. Two groups were defined according to the bone graft (with or without a bone graft) after cyst enucleation. The differences in the healing periods and patterns of bone healing were compared clinically and radiologically. The postoperative 1 year radiographs were analyzed for bone healing and density. Statistical analysis was performed using a Pearson chi square test and Wilcoxon rank-sum test. Results: More infection signs were observed in the bone graft group than in the other group, but there was no statistically significant difference. Radiographically, there was also no significant difference in the size of the radiolucent lesions between the two groups. Conclusion: There was no significant difference in healing between the groups with a bone graft and without bone graft after cyst enucleation.

• Journal of Periodontal and Implant Science
• /
• v.26 no.1
• /
• pp.266-275
• /
• 1996

The purpose of this study was to evaluate the effect of anatomical predisposing factors on the development of furcation involvement. Root trunk length, root divergency angle, buccal root trunk concavity and cervical enamel projection of the mandibular 1st and 2nd molars with(l03 teeth) and without(42 teeth) furcation involvement and enamel projection were classified by Lindhe's degree and Masters's classification, respectively, and buccal root trunk concavity was examined by probing. Statistical analysis was performed by means of ANOVA and CHI-SQUARE test in Microstat. The obtained results were as follows : 1. Root trunk length was longer in teeth without furcation involvement($4.20{\pm}1.05mm$) than teeth with furcation involvement(I : $3.62{\pm}0.68mm$, II : $3.64{\pm}0.86mm$, III: $3.61{\pm}0.74mm$)(p<0.05), but there was fno significant difference among furcation involvement group according to the degree of furcation involvement(p0>.05). 2. The root divergency angle was wider in teeth with furcation involvement(I : $53.14^0{\pm}15.11^0$, II : $44.82^0{\pm}14.26^0$, III : $52.69^0{\pm}16.09^0$) than teeth without furcation involvement($34.81^0{\pm}16.57^0$(p<0.05). 3. The group of teeth without furcation involvement showed significantly hign percentage of teeth without buccal root concavity, and the group of teeth with furcation involvement showed significantly hign percentage of teeth with buccal root concavity(p<0.05) 4. The group of teeth without furcation involvement showed higher percentage of teeth with grade I cervical enamel projection, teeth with furcation involvement I or II defect showed higher percentage of teeth with grade II enamel projection, and teeth with furcation involvement III defect showed higher percentage of teeth with grade III enamel projection(p<0.05) The results suggest that short root trunk length, wide root divergency, buccal root concavity and well-developed enamel projection could affect development and progression of furcation involvement as anatomical predisposing factors of periodontal diseases.