• Communications of the Korean Mathematical Society
• /
• v.8 no.3
• /
• pp.499-509
• /
• 1993

• Journal of the Korean Mathematical Society
• /
• v.28 no.2
• /
• pp.267-274
• /
• 1991

• Journal of Welding and Joining
• /
• v.32 no.4
• /
• pp.10-14
• /
• 2014

Laser aided Direct Metal Tooling(DMT) process is a kind of Additive Manufacturing processes (or 3D-Printing processes), which is developed for using various commercial steel powders such as P20, P21, SUS420, H13, D2 and other non-ferrous metal powders, aluminum alloys, titanium alloys, copper alloys and so on. The DMT process is a versatile process which can be applied to various fields like the mold industry, the medical industry, and the defense industry. Among of them, the application of DMT process to the mold industry is one of the most attractive and practical applications since the conformal cooling channel core of injection molds can be fabricated at the slightly expensive cost by using the hybrid fabrication method of DMT technology compared to the part fabricated with the machining technology. The main objectives of this study are to provide various characteristics of the parts made by DMT process compared to the same parts machined from bulk materials and prove the performance of the injection mold equipped with the conformal cooling channel core which is fabricated by the hybrid method of DMT process.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.4
• /
• pp.2663-2665
• /
• 2013

Objective: To compare the efficacy and complications of chemotherapy and late course three-dimensional conformal radiotherapy (3DCRT) in treating patients with stage III non-small cell lung cancer (NSCLC). Patients and Methods: All patients were divided into two groups: to receive chemotherapy and late course 3DCRT (3DCRT group), or chemotherapy and conventional fraction radiation (control group). In the 3DCRT-group, patients were given 6~15 MV X-rays with a total dose of 40 Gy, followed by 3DCRT, 2.5 Gy~3.0 Gy per fraction, 1 fraction/every day, total 68 Gy~70 Gy; in the control group, with conventional fraction radiation the total dose was 64~66 Gy. The chemotherapy regimen in both cases was EP (VP-16 and DDP). Results: Sixty four patients with stage III NSCLC were divided into two groups: 32 patients into 3DCRT, 32 into the control group. One and 2-year survival rates in 3DCRT and control group were 87.5%, 56.3%mad 65.6%, 34.4%, respectively (P<0.05); local control rates were 90.6%, 81.3% and 65.6%, 53.1%, respectively (P<0.05). Conclusion: Chemotherapy and late course 3DCRT is associated with improved survival rate in patients with stage III NSCLC with good tolerability.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.25 no.5
• /
• pp.592-600
• /
• 2014

This paper proposes an enhanced adaptive genetic algorithm(EAGA) dedicated to pattern synthesis of array antenna which conforms to a curved surface of rotation with quadratic function. EAGA combines adaptive genetic algorithm(AGA) with invasive weed optimization(IWO) for the faster convergence and the lower cost value of the cost function. The amplitude and phase of each excited weighting factor are optimized to meet the required goals using EAGA. The EAGA results indicate that the proposed algorithm is superior to AGA when applied to the problem of conformal array antenna pattern synthesis.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.5
• /
• pp.1743-1745
• /
• 2015

Objective: To evaluate the efficacy and adverse effects of three dimensional conformal radiotherapy (3D-CRT) with tamoxifen in treating patients with postoperative malignant glioma. Patients and Methods: 60 patients of postoperative malignant glioma were randomly assigned into two groups, 30 patients were treated with 3D-CRT plus tamoxifen (treatment group), and the other 30 patients with 3D-CRT plus temozolomide (control group). All patients were radiated by 6MV X-ray, 2.0Gy per fraction, once daily, with a total dose (DT) of 56~60Gy. Tamoxifen was delivered at $60mg/m^2/d$, temozolomide was given at $75mg/m^2/d$. All patients were treated with concurrent radiotherapy. Results: One, 2, 3 year survival rates of treatment and control group were 63.3%, 30.0%, 23.0% and 70.0%, 33.3%, 26.7%, respectively (${\chi}^2=0.01$, 0.23, 0.09, P>0.05). The rate of thromboembolism in treatment group was 6.7%. Conclusion: Therapeutic efficacy of two groups was similar, but it was more cost-effective in treatment group, and toxicity did not increase.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2009.06a
• /
• pp.28-28
• /
• 2009

Fabrications of antireflection structures on solar cell were investigated to trap the light and to improve quantum efficiency. Introductions of patterned substrate or textured layer for Si solar cell were performed to prevent reflectance and to increase the path length of incoming light. However, it is difficult to deposit conformally flat electrode on perpendicular plane. ZnO is II-VI compound semiconductor and well-known wide band-gap material. It has similar electrical and optical properties as ITO, but it is nontoxic and stable. In this study, Al-doped ZnO thin films are deposited as transparent electrode by atomic layer deposition method to coat on Si substrate with micro-scale structures. The deposited AZO layer is flatted on horizontal plane as well as perpendicular one with conformal 200 nm thickness. The carrier concentration, mobility and resistivity of deposited AZO thin film on glass substrate were measured $1.4\times10^{20}cm^{-3}$, $93.3cm^2/Vs$, $4.732\times10^{-4}{\Omega}cm$ with high transmittance over 80%. The AZO films were coated with polyimide and performed selective polyimide stripping on head of column by reactive ion etching to measure resistance along columns surface. Current between the micro-columns flows onto the perpendicular plane of deposited AZO film with low resistance.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.8
• /
• pp.4163-4167
• /
• 2012

Aims: To prospectively assess the efficacy and safety of moderately hypofractionated conformal radiotherapy in patients with thoracic esophageal cancer. Methods and Materials: From Sept. 2002 to Oct, 2005, 150 eligible patients with T2-4N0-1M0 stage thoracic esophageal squamous cell cancers were enrolled to receive either conventional fractionated radiation (CFR) or moderately hypofractionated radiation (MHR) with a three-dimensional conformal radiation technique. Of the total, 74 received moderately hypofractionated radiation with total dose of 54-60Gy/18-20fractions for 3.5-4 weeks in the MHR arm, and 76 received conventional radiation with total dose of 60Gy/30 fractions for 6 weeks in the CFR arm. Concurrent chemotherapy comprised of paclitaxel and cisplatin. Safety was evaluated, and local control and overall survival rates were calculated. Results: Statistically significant differences between the CFR versus MHR arms were observed in local/regional failure rate (47.3% v 27.0%, P=0.034) and the percentage of patients with persistent local disease (26.3% v 10.8%, P=0.012). But 3 and 5-year overall survival rates (43.2%, 38.8% v 38.2%, 28.0%, respectively) were not different between the two arms (P=0.268). There were no significant differences in the incidences of grade 3 or higher acute toxicities (66.3% v 50.0%) and late complications rates (27.0% v 22.4%) between the MHR and CFR arms. Conclusions: Moderately hypofractionated, three-dimensional radiation treatment could improve the local control rate of esophageal cancer and potentially increase patients' survival.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.27 no.6
• /
• pp.491-494
• /
• 2016

A design method is proposed to minimize the scattering cross section(SCS) of the electromagnetic cloak based on the quasi-conformal mapping. Often times in such cloaking structures, parts that require refractive index below one are approximated with free space because of the difficulty involved with realization. In this process, preformance degradation is inevitable. In this work, the size of the cloak is optimized to compensate for the deterioration, and thus to minimize the scattering cross section of a diamond shaped conductor. Proposed cloak is fabricated using a 3D printer, and verified by measuring the cloaking performance of a diamond shaped aluminum target.

• 대한공업교육학회지
• /
• v.33 no.2
• /
• pp.273-286
• /
• 2008

Underwater acoustic sensor array can detect acoustic signal in underwater and the sensor array can be mounted in each left, right or front side of the UUV(Unmanned Underwater Vehicle). The sensor array could be conformal array and effected turbulent boundary layer flow noise. Therefore, in this paper numerical simulations were performed to know the how the outer flow noise affect the hydrophone which embedded in the elastomer. Corcos wall pressure model was used as turbulent boundary layer flow noise and this model was applied to the frequency density function. Characteristics of transfer function according the kx wave number were simulated and design parameters were thickness of elastomer, density, and modulus of elasticity. Based on the simulation results when increasing the thickness of elastomer noise reduction was increased. This results can be applied to the design of conformal array of UUV.