• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.10
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• pp.1197-1205
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• 2014

Recently signal transmission of ultra high-definition(4K-UHD) video system is transferred as uncompressed high speed data. However, this has a limit to compose the system because EMI between separate cables of high speed interface section and skew bring distortion of the video signal and jitter. In this paper we applied V-by-One HS interface technique to transfer uncompressed high speed data. We analyzed HSD(High Speed Differential) transmission line signal integrity. Also we applied RF transmission technique instead of UHD video pattern control interface PCB design. When we measured V-by-One HS video signal of designed 4K-UHD class signal generator, We found that the transmission performance has been signal standard.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.432-435
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• 2008

It's necessary to judge between success and failure of a project in order to secure the objective evaluation index and the transparency of that. In case of the public works including a construction section, the large-scale budget input proceeds, but the awareness regarding the efficiency and usefulness of the public works is decreasing because it's hard to estimate benefit originated from the results of the budget input. Therefore, this study is to propose the measurement standard for the post-evaluation based on the list of the resident response degree and user satisfaction degree to systematically and quantitatively measure the results of the post-evaluation for the public projects within the range of quantifying the consumer satisfaction degree for the facilities which preform the post-evaluation among the public projects with 50 billion budget.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.2
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• pp.349-353
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• 2012

As the world wind energy market grows rapidly, the productions of wind power generation equipment have recently increased, but manufacturers are not able meet this requirement. Particularly offshore wind energy industry is one of the most popular renewable energy sectors. To generalize welding processes, the welding automation is considered for steel structure manufacturing in offshore wind energy to get high quality and productivity. Welding technology in construction of the wind towers is depended on progress productivity. In addition, the life of wind tower structures should be considered by taking account of the natural weathering and the load it endures. The root passes are typically deposited using Gas Tungsten Arc Welding(GTAW) with a specialized backing gas shield. Not only the validation consists of welders experienced in determining the welding productivity of the baseline welding procedure, but also the standard testing required by the ASME section IX and API1104 codes, toughness testing was performed on the completed field welds. This paper presents the welding characteristics of the root-pass welding of high tensile steel in manufacturing of offshore wind tower. Based on the result from welding experiments, optimal welding conditions were selected after analyzing correlation between welding parameters(peak current, background current and wire feed rate) and back-bead geometry such as back-bead width(mm) and back-bead height performing root-pass welding experiment under various conditions. Furthermore, a response surface approach has been applied to provide an algorithm to predict an optimal welding quality.

• 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.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.7
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• pp.561-568
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• 2013

After we designed Bearingless rotor hub system for 7,000lb class helicopter, flexbeam fatigue analysis was conducted for validation of requirement life time 8,000 hours. sectional structural analysis method applying elastic beam model was used. Fatigue analysis for two sections of flexbeam which were expected to weak to fatigue damage from result of static analysis was conducted. Extension, bending and torsion stiffness of flexbeam section shape was calculated using VABS for structure analysis. S-N curve of two composite material which composed flexbeam was generated using wohler equation. Load analysis of bearingless rotor system was conducted using CAMRAD II and load analysis result was applied HELIX/FELIX standard load spectrum to generate bearingless rotor system load spectrum which was used flexbeam fatigue safe life analysis.

• Journal of the Korean Society for Nondestructive Testing
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• v.34 no.4
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• pp.311-317
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• 2014

The Pressurized water reactor owners group (PWROG) developed and applied a risk-informed in-service inspection (RI-ISI) program, as an alternative to the existing ASME Section XI' sampling inspection method. The RI-ISI programs enhance overall safety by focusing inspections of piping at high safety significance (HSS) locations where failure mechanisms are likely to be present. Additionally, the RI-ISI program can reduce nondestructive evaluation (NDE) exams, man-rem exposure for inspectors, and inspection time, among other benefits. The RI-ISI method of in-service piping inspection was applied to 3 units (KSNPs: Korea standard nuclear power plants) and is being deployed to the other units. In this paper, the results of RI-ISI for a Framatome type (France CPI) nuclear power plant are presented. It was concluded that application of RI-ISI to the plant could enhance and maintain plant safety, as well as provide the benefits of greater reliability.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.2001-2005
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• 2005

The tensile test is generally used to measure mechanical properties with conventional fracture test. This test is extremely certain method to measure Young's modulus, yield strength, tensile strength and so on. ASTM, by international standard, prescribes two classes of tensile tests in tubular products. One is method that specimens aren't done by any process with Tube-shape. The other is that specimens are made on process for C-shape. In this paper, we would like to present the new-shape specimens for the tensile test. The presented specimen's shape is that put two pieces of C-shape specimens together. Besides a load point and a support point are fixed like Tube-shape specimens. This shape of specimen has a difference that existing specimen is made on one-step process out this specimen is made on two-step process. This shape is considered that stress concentration phenomenon occurs at the reduced section if a specimen is made on one step process.

• Journal of Korean Society of Steel Construction
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• v.10 no.4 s.37
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• pp.657-666
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• 1998

This study presents an effective dual algorithm for the optimal design of steel structures with displacement constraints. The dual method can replace a primary optimization problem with a sequence of approximate explicit subproblems with a simple algebraic structure. Since being convex and separable, each subproblem can be solved efficiently by the dual method. Specifically, this study uses the principle of virtual work to obtain the displacement constraint equations with an explicit form and adds the linear regression equation expressing the relationships between the cross-section properties to the dual algorithm to reduce the number of design variables. Furthermore, this study deals with the discrete optimization problem to select members with the standard steel sections. Through numerical analyses, the proposed method will be compared with the conventional optimality criteria method.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.4
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• pp.333-339
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• 2007

Adequate bone quantity is one of the important factor to obtain osseointegration after implantation. Guided bone regeneration (GBR) has widely used in implantation for reconstruction of bony defects. Since introducing this procedure, there are many studies about survival rate of implants, changing in surrounding bone volume after function. The purpose of this study was to evaluate the amount of resorption according to placement timing and survival rate after function. The subjects were patients who had been operated with GBR from Jun 2003 to Jun 2004 in Seoul National University Bundang Hospital. They were divided into simultaneous and delayed placement group. The follow up had been performed at the time of just after GBR, 1, 3, 6, 12, 24-month later and standard periapical radiographs were taken to estimate the bone level at the time. The total average of bone level change in radiographs was 1.94mm(${\pm}0.25$), and 1.92mm(${\pm}0.72$) in simultaneous installation, 2.03mm(${\pm}0.25$) in delayed installation. In this report, the survival rates were 92.2% in simulataneous group and 92.3% in delayed group. Insufficient primary stability, early contamination of wound, overloading, poor oral hygiene, and infection were thought to be associated factors in the failed cases.

• Journal of Ocean Engineering and Technology
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• v.30 no.3
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• pp.201-207
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• 2016

In this paper, an aluminum pressure vessel (cylinder) for a 200 m water depth is designed and analyzed. Because of their lack of usage in the deep sea, only a few papers about pressure vessels subjected to external pressures have previously been published. Moreover, the high level of imported external-pressure-vessel products limits the academic pursuit. Yet, research on internal pressure vessels is widely available because of their broad usage at onshore. This paper presents the process of basic designing and modelling of pressure vessels using the design rules of American Standard of Mechanical Engineering (ASME) Section VIII Division 1. To promote understanding, finite element analysis (FEA) result of an existing sample cylinder which was not designed by ASME code is compared with the design obtained in this paper. Several methodologies are used for the finite element analysis, including rectangular, cylindrical, and axisymmetric coordinate, to attain an accurate stress result. Same dimensions except the thickness of the cylinder and loading condition of 0.200 MPa was given for the current study. Finally, a rigorous design procedure is added for the bolt and boundary conditions of the cylindrical body and its ends. The obtained stress level satisfies the allowable design stress value specified in the ASME code.