• KSBB Journal
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• v.18 no.2
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• pp.107-110
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• 2003

Biodegradable polymers, poly(lactic-co-glycolic acid) (PLGA), poly(3-hydroxybutyrate) (PHB), and medium chain length polyhydroxyalkanoates (MCL-PHA) containing rose bengal (model drug) were coated onto the surface of stainless steel (stent materials) and their in vitro release characteristics were investigated. Drug release increased with; decreasing PLGA concentration, increasing rose bengal concentration, and Increasing dip-coating duration. The order of drug release from the polymer coating was: PHB > PLGA > MCL-PHA. These results suggest that drug release can be controlled by: changing the concentration and type of polymer, the drug concentration, and the dip-coating duration.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.5
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• pp.1333-1339
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• 1995

Recently developed technique of measuring minor species concentration by using the modulation dip in broadband CARS has been applied to the flame structure study of methane/air premixed flames in a counterflow. This method used the modulation dip from the cold band CO Q-branch resonant signal superimposed on the nonresonant background. The measured CO concentration profile in a symmetric and unsymmetric methane/air premixed flames together with the velocity and temperature by using LDV and CARS have been compared with the numerical results adopting detailed chemistry modeling. The results show that there is a satisfactory agreement between the experimental data and numerical results for velocities, temperatures and CO concentrations. And the modulation dip technique of measuring minor species, such as CO is a viable tool for a quantitative measurement in a flame.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.1843-1846
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• 2003

In MPEG-21 Multimedia Framework, Digital Item (DI) is the minimum unit fur processing and delivering the multimedia contents. So how to process, manipulate and represent DI is a very important problem in the standpoint of interoperability for each terminal and provide., and Digital Item Processing (DIP) regarding this issue. This paper suggests technologies which are concerning how DIP should interact with other parts of MPEG-21 (Digital Item Adaptation (DIA), Intellectual Property Management and Protection (IPMP), etc.). For this concept, this paper uses the video summary contents which can describe the hierarchical structures of original multimedia contents. In MPEG-21 environment, the usage of this summary video is very useful delivery and consumption way in view of network burden, efficient accessing to contents.

• Korean Membrane Journal
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• v.7 no.1
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• pp.19-27
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• 2005

PP hollow fiber membrane was hydrophilized by EVOH dip coating followed by low temperature plasma treatment and UV irradiation. EVOH coating attained high water flux without any prewetting but its stability did not guaranteed at high water permeation rate. At high water permeation rate, water flux declined gradually due to swelling and delamination of the EVOH coating layer causing pore blocking effect. However, plasma treatment reduces the swelling, which suppress delamination of the EVOH coating layer from PP support result in relieving the flux decline. Also, UV irradiation helped the crosslinking of the EVOH coating layer to enhance the performance at low water permeation rate. FT-IR and ESCA analyses reveal that EVOH dip coating performed homogeneously through not only membrane surface but also matrix. Thermogram of EVOH film modified plasma treatment and W irradiation show that crosslinking density of EVOH layer increased. Chemical modification by plasma treatment and UV irradiation stabilized the hydrophilic coating layer to increase the critical flux of the submerged membrane.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.232-234
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• 2002

Due to development of power electronics technology, power conversion system are tend to small size, easy to use and light weight. Especially motor control system have increased concerns and interests about IPM(Intelligent Power Module) inverter, which contains protection circuit, drive circuit and power devices. So, we manufactured 3-phase inverter using DIP-IPM(Dual in-line package IPM) PS21245- E(1.5 Kw) made by MITSUBISHI Electric. Some of these features include -HVIC to Provide level shifting and gate drive for high-side IGBTs. The interface circuit between pwm controller and DIP-IPM can made by direct connection. In order to validate dynamic performance of the proposed system, the actual experiment worked out at wide speed range. The developed system is shown as a good dynamic characteristics.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.215-222
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• 2007

Coating of Hot-dip galvannealed steel consists of various Fe-Zn intermetallic compounds. Since the coating is hard and there for is very brittle, the surface of steel sheet is easy to be ruptured during second manufacturing processing. This is called as powdering. In addition, forming equipment might be polluted with debris by powdering. Therefore, various research have been carried out to prohibit powdering fur improving the quality of GA steel. This paper carried out finite element analysis combined with damage model which simulate the failure of local layer of hot-dip galvannealed steel surface during v-bending test. Since the mechanical property of intermetallic compound was unknown exactly, we used the properties calculated from measurements. The specimen was divided into substrate, coating layer and interface layer. Local failure at coating layer or interface layer was simulated when elemental strain reached a prescribed strain.

• Journal of the Korean institute of surface engineering
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• v.36 no.1
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• pp.42-47
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• 2003

Hot-dip galvanizing process is used widely in industry to achieve corrosion resistant coatings. Poor drainage during this process often leads to problems such as icicle formation and bridging In this work, mild steel specimens were hot-dip galvanized. Influence of the addition of bismuth, aluminum and both (bismuth and aluminum) to the zinc bath on the zinc drainage were determined. Bismuth additions improved the drainage significantly. Zinc bath containing 0.1 wt.% Bi and 0.025∼0.05 wt.% Al showed uniformity of coatings. Industrial trials with this bath composition showed reduction in zinc consumption, reduction of ash and dross, and good luster of workpiece.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.218-218
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• 2003

• The Korean Journal of Pain
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• v.27 no.4
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• pp.345-352
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• 2014

Background: Epidural administration of dexamethasone has been suggested for pain control after minor orthopedic surgery. This study was conducted to assess its efficacy after such surgery, combined or not to IV dipyrone, IV parecoxibe or their combination. Methods: 91 patients were randomly assigned to seven groups. Patients were submitted to spinal bupivacaine anesthesia combined to epidural administration of either 10 ml saline or 10 mg dexamethasone diluted to 10-ml volume. Patients also received 10 ml IV saline or 1 gr dipyrone and/or 40 mg parecoxibe diluted to 10 ml with saline. Control group (CG) received epidural and IV saline. Dexamethasone group (DexG) received epidural dexamethasone and IV saline. Dipyrone group (DipG) received epidural saline and IV dipyrone. Dex-Dip G received epidural dexamethasone and IV dipyrone. Parecoxibe group (ParG) received epidural saline and IV parecoxibe. Dex-ParG received epidural dexamethasone and IV parecoxibe. Finally, Dex-Dip-ParG received epidural dexamethasone and IV dipyrone plus IV parecoxibe. Results: The CG expressed 4h of analgesia and sooner requested pain killer. DexG was similar to DipG or ParG or Dex-ParG (7-hours), and they requested less ketoprofen compared to the CG (P < 0.05). However, the Dex-DipG and the Dex-Dip-ParG resulted in longer time to demand pain killer (17-hours) and less ketoprofen consumption in 24-hours (P < 0.002). Adverse effects were similar among groups. Conclusions: The analgesia secondary to epidural dexamethasone was enhanced by IV dipyrone, while no effects were observed by the addition of IV parecoxibe.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.272-275
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• 2003

This paper presents the role and its function of Tool server. MPEG-21 means multimedia framework for delivery and consumption of multimedia which is being discussed in ISO/IEC 21000. A view of MPEC-21 aims to define multimedia framework to enable transparent use of multimedia resource across a wide range of networks and devices used by different communities. MPEG-21 will enable all-electronic creation delivery and trade of digital multimedia content and transparent usage of various content types on network device. Therefore, we can provide access to information and services from almost anywhere at anytime with various terminals and networks. In order to support multimedia delivery chain that contains content creation, production, delivery and consumption, we need many standards(elements) for identify, describe, manage and protect the content. Thus, we define Digital Item Player(DIP), Digital Item Adaptation(DIA) server and Tool server as primary objects of MPEG-21 multimedia framework. DIP provides a function which creates and consumes Digital Item(DI) as a kind of a digital object by user. A DI contains both media resources and metadata including rights information. DIA server deals with the usage environment description schema of the user characteristics, terminal and network characteristics and natural environments. DIA server adapts the original DI to the usage environment description sent from the terminal and transmits the adapted DI to the terminal. Tool server searches for a tool requested from DIP or DIA and downloads the best tool to DIP or DIA server. In this paper, we present how Tool sewer is organized and is used among 2 primary objects. The paper is structured as followings: Section 1 briefly describes why MPEG-21 is needed and what MPEG-21 wants. We see requirement that tool server must equip functionally in section 2. The proposed tool server,its structure and its functionality are presented in section 3. Section 4 explains a scenario that tool server transmits tool to DIP and shows the experimental result. The paper concludes in section 5.