• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.6
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• pp.969-975
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• 2000

New class of three dimensional (3-D) micromachined microwave planar filters at K and Ka-band are presented using LIGA micro-machined process. The K-and Ka-band filters show wide bandpass characteristics of~36% and ~39% with the insertion loss 1.26dB at 19.11GHz and 1.7dB at GHz, respectively. These filters can be applicable in high power MMIC of MIMIC.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5381-5384
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• 2012

Background and Aim: Cholangiocarcinoma (CCA) is an uncommon malignancy of the bile duct, occurring in nearly 2 out of 100,000 people. It is a type of adenocarcinoma that originates in the mucous glands of the epithelium, or surface layers of the bile ducts. The aim of this study was to evaluate the clinical features, diagnostic results and factors associated with survival, morbidity and mortalityof cholangiocarcinoma cases in Iranian patients. Method: In this retrospective study the hospital medical records of 283 patients with a primary or final diagnosis of cholangiocarcinoma who had been admitted to gastroenterology ward of our hospital from 2004 to 2011 were retrospectively reviewed. Results: 283 patients (180 male, 63%, and 103 female, 38.6%) with a mean age of $59.7{\pm}14.4$ years were studied. The most frequent symptoms were painless jaundice (190, 66.9%), abdominal pain (77, 27%), pruritus 133 (46.8%) and weight loss (169, 59.5%). The most frequent associated risk factors and diseases were as follows: gallstones (72, 25.4%), diabetes (70, 24.6%), HBV infection (52 (18.3%), HCV infection 43 (15%), primary sclerosing cholangitis (16, 5.6%) and smoking (120, 42.3%). The most frequent type of cholangiocarcinoma in ERCP and MRCP was hilar. The mean survival time was $7.42{\pm}5.76$ months. Conclusion: The mean survival time in our study was lower than one year. Moreover the most frequent risk factors and associated diseases were smoking, gallstones and diabetes. Painless jaundice, abdominal pain and weight loss were the most clinical features related to cholangiocarcinoma. Additionally survival time did not correlate with risk factors, associated diseases and clinical presentations, but was linked to biliary metallic stenting and surgery.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.1
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• pp.117-125
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• 2014

The temperature distribution of steady state rolling tires with detailed tread blocks is numerically predicted using the three dimensional full patterned tire model. A three dimensional periodic patterned tire model is constructed by copying 1-sector mesh in the circumferential direction. Using the static tire contact analysis, the strain cycles during one revolution are approximated with the strains at Guassian points of the elements which are sector-wise repeated within the same circular ring of elements, by neglecting the tire rolling effect. Based upon the multi-axial fatigue theory, the maximum principal strain is used to represent the combined effect of six strain components on the hysteretic loss. In the following, the deformation due to the inflation and vertical load is calculated using ABAQUS. Then heat generation rate in each element is calculated using an in-house code. Lastly, temperature distribution is calculated using ABAQUS again. Through the numerical experiments, the validity of the proposed prediction method is examined by comparing with the experiment and the temperature distribution of a patterned tire model is compared with those of the main-grooved simple tire model.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.326-326
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• 2010

The dielectric properties of continuous composition spreaded (CCS) $BaTiO_3-SrTiO_3$ (BST) thin filmsgrown at room temperature and annealed at different temperature ($350^{\circ}C$ and $550^{\circ}C$) were investigated. Moreover, electrical properties (leakage current and breakdown voltage) of CCS BST thin films were also investigated. The aluminum top-electrode, sized by $200{\times}200\;{\mu}m2$ and apart from each other by $300\;{\mu}m$, were deposited on the CCS BST thin films by the DC sputtering system. The dielectric properties of the CCS BST thin films were significantly influenced depending on the distance from $BaTiO_3$ and $SrTiO_3$ targets which was attributed to the $BaTiO_3-SrTiO_3$ composition ratio. The maps of dielectric constants and loss tangents were plotted via $1500\;{\mu}m$ - step measuring. The specific points showing the dielectric constant (k: ~300) and loss tangent (tand: ~0.008) at 1 MHz were found.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.11
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• pp.1639-1645
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• 2016

We investigated marinade absorption and physicochemical characteristics of vacuum-aged duck breasts that were halved and individually vacuum-packed for chiller aging at $4^{\circ}C$ for 14 d. One half was marinated for 0, 7, or 14 d, while the second half was used as a control. Marinade absorption, cooking loss, cooking yield, texture profile, pH, color, protein solubility, and thiobarbituric acid reactive substances (TBARS) values were evaluated, and protein sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed. Marinade absorption and pH did not vary significantly after 14 d of aging. Marination increased the pH, color ($a^*$ and $b^*$) values, and cooking yield and reduced cooking loss. TBARS values significantly increased with aging time, but were significantly reduced by marination. Myofibril and total protein solubility increased with aging and marination, while SDS-PAGE showed protein degradation. Hence, aging and marination can be used simultaneously to improve physicochemical quality and cooking yield of vacuum-aged duck breast.

• Korean Journal of Veterinary Service
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• v.40 no.3
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• pp.177-185
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• 2017

In this study, we evaluated the efficacy of a commercial vaccine stress-relieving agent (Anti VS-2 injection) to reduce the adverse effects of foot-and-mouth disease (FMD) vaccination site in 120 pigs on two tested pig farms. The results showed that incidence of pig with abnormal meat, size of abnormal meat and weight of discarded abnormal meat are significantly decreased in Anti VS-2 injection-supplemented FMD vaccinated pig groups (n=60) compared to the non-supplemented FMD vaccinated pig groups (n=60) (P<0.05). And the average economic loss by discard of abnormal meat were estimated 99,382 won or 21,514 won in the non-supplemented FMD vaccinated groups or in the Anti VS-2 injection-supplemented FMD vaccinated groups, respectively, showing that the cost saving effect was 78% (77,869 won). In conclusion, it is expected to reduce the incidence and severity of abnormal meat in the FMD vaccinated pigs and to contribute not only to the reduced economic loss of pig farmers but also to the promotion of food hygiene when the Anti VS-2 injection is mixed with FMD vaccine.

• Archives of Reconstructive Microsurgery
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• v.13 no.1
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• pp.63-67
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• 2004

Because traumatic tissue damage on hands and feet often lead to loss of function, permanent deformity, prompt and adequate reconstruction is essential. For children, future growth, as well as function and esthetics, must be taken into account. Several techniques have been employed to reconstruct hand and foot dorsum defects of children. However, skin graft and muscle free flap with skin graft cannot prevent contracture and will interfere with normal growth. Fasciocutaneous free flap reduces contracture and enables early physical therapy, decreasing the need for additional surgical intervention. Parascapular flap is particularly suitable because it has reliable pedicle and is relatively thin. There is little functional loss in the donor site, and also simultaneous extensor tendon reconstruction of hand and foot is possible. The disadvantage of this technique is that postoperative defatting is needed to adjust volume. Our department has achieved satisfactory results using this approach, and would like to report 13 cases of hand and foot reconstruction using parascapular flap in patients under the age of 15 (from March, 1998 to May, 2003).

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.117-117
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• 2016

Total ankle replacement (TAR) is a visible option in the surgical treatment of degenerative or inflammatory diseases of ankle joint. it is attributed to the current TAR which has improvements in surgical technique, uncemented implant fixation and minimally constrained articulation. In the clinical result, they can show promised surgical result when compared to earlier attempts in TAR. However, TAR is still not as successful as total knee replacement (TKR) or total hip replacement (THR), it needs to be note that there are limitations in concerning of long term performance of TAR, the high failure rate still associated with wear of the PE (polyethylene) component that has related with their material property and surface roughness. The aim of this study was to introduce the tribology characteristics of total ankle joint prosthesis with one of TDR model which was fabricated to try multi-axis wear test as a region of motion in ankle joint. The wear specimen of TDR was prepared with Ti-6Al-4V alloy and UHMWPE (ultra-high molecular weight polyethylene) for tibia-talus and bearing component, respectively. A wear test was carried out using a Force 5 (AMTI, Massachusetts, US) wear simulator which can be allowed to move in three axis to flexion-extension ($+3^{\circ}{\sim}-6^{\circ}$), internal-external axial rotation (${\pm}5^{\circ}$), as well as sinusoidal compressive load (1.6 kN, R=10). All tests were performed following standard ISO 14243, wear rate was calculated with weight loss of UHMWPE bearing while the specimen has tested at certain cycles. As based on the preliminary results, wear rate of UHMWPE bearing was $7.9{\times}10^{-6}mg/cycles$ ($R^2=0.86$), calculated loss weight until $10^7cycles$ was 79 mg, respectively.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.5
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• pp.410-420
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• 2015

This paper provides a comparison of power converter loss and thermal description for voltage source and current source type 5 MW-class medium-voltage topologies of wind turbines. Neutral-point clamped three-level converter is adopted for a voltage source type topology, whereas a two-level converter is employed for current source type topology, considering the popularity in the industry. To match the required voltage level of 4160 V with the same switching device of IGCT as in the voltage source converter, two active switches are connected in series for the case of current source converter. Transient thermal modeling of a four-layer Foster network for heat transfer is done to better estimate the transient junction and case temperature of power semiconductors during various operating conditions in wind turbines. The loss analysis is confirmed through PLECS simulations. Comparison result shows that the VSC-based wind turbine system has higher efficiency than the CSC under the rated operating conditions.

• Journal of electromagnetic engineering and science
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• v.19 no.1
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• pp.64-70
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• 2019

In this study, a compact series-fed center-fed open-stub (SFCFOS) linear array antenna for K-band applications is presented. The antenna is composed of a single-line 10-element linear array. A symmetrical Chebyshev amplitude distribution (CAD) is used to obtain a low sidelobe characteristic against a uniform amplitude distribution (UAD). The amplitude is controlled by varying the width of the microstrip patch elements, and open-ended stubs are arranged next to the last antenna element to use the energy of the radiating signal more effectively. We insert a series-fed stub between two patches and obtain a low mutual coupling for a 4.28-mm center-to-center spacing ($0.7{\lambda}$ at 21 GHz). A prototype of the antenna is fabricated and tested. The overall size of the uniform linear array is $7.04{\times}1.05{\times}0.0563{\lambda}_g^3$ and that of the Chebyshev linear array is $9.92{\times}1.48{\times}0.0793{\lambda}_g^3$. The UAD array yields a ${\mid}S_{11}{\mid}$ < -10 dB bandwidth of 1.33% (20.912-21.192 GHz) and 1.45% (20.89-21.196 GHz) for the CAD. The uniform array design gives a -23 dB return loss, and the Chebyshev array achieves a -30.68 dB return loss at the center frequency with gains of 15.3 dBi and 17 dBi, respectively. The simulated and measured results are in good agreement.