• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.43 no.6
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• pp.373-387
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• 2017

Objectives: The purpose of this study was to introduce our three experiments on bone morphogenetic protein (BMP) and its carriers performed using the critical sized segmental defect (CSD) model in rat fibula and to investigate development of animal models and carriers for more effective bone regeneration. Materials and Methods: For the experiments, 14, 16, and 24 rats with CSDs on both fibulae were used in Experiments 1, 2, and 3, respectively. BMP-2 with absorbable collagen sponge (ACS) (Experiments 1 and 2), autoclaved autogenous bone (AAB) and fibrin glue (FG) (Experiment 3), and xenogenic bone (Experiment 2) were used in the experimental groups. Radiographic and histomorphological evaluations were performed during the follow-up period of each experiment. Results: Significant new bone formation was commonly observed in all experimental groups using BMP-2 compared to control and xenograft (porcine bone) groups. Although there was some difference based on BMP carrier, regenerated bone volume was typically reduced by remodeling after initially forming excessive bone. Conclusion: BMP-2 demonstrates excellent ability for bone regeneration because of its osteoinductivity, but efficacy can be significantly different depending on its delivery system. ACS and FG showed relatively good bone regeneration capacity, satisfying the essential conditions of localization and release-control when used as BMP carriers. AAB could not provide release-control as a BMP carrier, but its space-maintenance role was remarkable. Carriers and scaffolds that can provide sufficient support to the BMP/carrier complex are necessary for large bone defects, and AAB is thought to be able to act as an effective scaffold. The CSD model of rat fibula is simple and useful for initial estimate of bone regeneration by agents including BMPs.

• The Journal of the Korea Contents Association
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• v.8 no.9
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• pp.172-184
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• 2008

The purpose of this study analyzes services and the markets creating the profit of the national home network industry and the promotion strategy will be proposed. First, the technologies and products of the home network industry are analyzed, and the value chain of this industry is grasped. Second, the home network industry is classified into the communication common carrier, the construction carrier, the content/solution carrier, and the electronic business carrier. Third, The business model of the home network industry reconstructed based on the researches of Morris et al.(2005) and Chesbrough and Rosenbloom(2002), and the strategies are analyzed. We performed the industrial analysis as the company environment analysis, factor analysis of the value creation, business strategy analysis and so on.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.4
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• pp.373-382
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• 2019

This paper shows numerical results for the estimation of the propulsor efficiency of Pre-Swirl Duct for 176k bulk carrier as well as its design method. Reynolds averaged Navier-Stokes equations have been solved and the k-epsilon model applied for the turbulent closure. The propeller rotating motion is determined using a sliding mesh technique. The design process is divided into each part of Pre-Swirl Duct, duct and Pre-Swirl Stator. The design of duct was performed first because it is located further upstream than Pre-Swirl Stator. The distribution of velocity through the duct was analyzed and applied for the design of Pre-Swirl Stator. The design variables of duct include duct angle, diameter, and chord length. Diameter, chord length, equivalent angle are considered when designing the Pre-Swirl Stator. Furthermore, a variable pitch angle stator is applied for the final model of Pre-Swirl Duct. The largest reduction rate of the delivered power in model scale is 7.6%. Streamlines, axial and tangential velocities under the condition that the Pre-Swirl Duct is installed were reviewed to verify its performance.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.11
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• pp.42-46
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• 2006

As an application of SDINS/GPS integration for its synergistic results, the SDINS alignments utilizing GPS carrier phase rate measurements. A measurement model of GPS carrier phase rate is derived in order to be used with SDINS alignment process. For in-flight alignment, the performance of the suggested SDINS/GPS integration method is analyzed using the covariance analysis and its results are confirmed by those of van test. Consequently, it is shown that all states of the SDINS integrated system by utilizing GPS carrier phase rate measurements can be estimated more efficiently than a general SDINS/GPS during in-flight alignment.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.11
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• pp.1085-1091
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• 2014

This paper presents the guidance and control design for automatic carrier landing of a UAV (Unmanned Aerial Vehicle). Differently from automatic landing on a runway on the ground, the motion of a carrier deck is not fixed and affected by external factors such as ship movement and sea state. For this reason, robust guidance/control law is required for safe shipboard landing by taking the relative geometry between the UAV and the carrier deck into account. In this work, linear quadratic optimal controller and longitudinal/lateral trajectory tracking guidance algorithm are developed based on a linear UAV model. The feasibility of the proposed control scheme and guidance law for the carrier landing are verified via numerical simulations using X-Plane and Matlab/simulink.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.179-184
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• 2006

Rapid and high-precision positioning with a Global Navigation Satellite System (GNSS) is feasible only when very precise carrier-phase observations can be used. There are two kinds of mathematical models for ambiguity resolution. The first one is based on both pseudorange and carrier phase measurements, and the observation equations are of full rank. The second one is only based on carrier phase measurement, which is a rank-defect model. Though the former is more commonly used, the latter has its own advantage, that is, ambiguity resolution will be freed from the effects of pseudorange multipath. Galileo will be operational. One of the important differences between Galileo and current GPS is that Galileo will provide signals in four frequency bands. With more carrier-phase data available, frequency combinations with long equivalent wavelength can be formed, so Galileo will provide more opportunities for fast and reliable ambiguity resolution than current GPS. This paper tries to investigate phase only fast ambiguity resolution performance with four Galileo frequencies for short baseline. Cascading Ambiguity Resolution (CAR) method with selected optimal frequency combinations and LAMBDA method are used and compared. To validate the resolution, two tests are used and compared. The first one is a ratio test. The second one is lower bound success-rate test. The simulation test results show that, with LAMBDA method, whether with ratio test or lower bound success rate validation criteria, ambiguity can be fixed in several seconds, 8 seconds at most even when 1 sigma of carrier phase noise is 12 mm. While with CAR method, at least about half minute is required even when 1 sigma of carrier phase noise is 3 mm. It shows that LAMBDA method performs obviously better than CAR method.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.2
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• pp.223-231
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• 2010

Purpose : The Purpose of this study was to compare muscle activation and foot pressure on baby carrier and sling for baby care. Methods : Thirty one women subjects (mean age 23.2 years) participated in four static conditions : unloaded quite standing, carrying an anterior baby carrier, carrying a posterior baby carrier, and sling. The baby carrier and sling were loaded with baby model that filled 7.6kg loads. Surface electromyography was used to measure activity in the internal oblique, T4, L3, L5 paraspinal muscle, vastus medialis, biceps femoris, tibialis anterior, and gastrocnemius for four conditions. And foot pressure was measured by using MatScan system(Tekscan, USA). Results : The activation of Biceps femoris, T4, L3, and L5 paraspinal muscle were significant differences(p<.05), but other muscles were no significant differences in four conditions(p>.05). Right foot contact area and peak pressure of right mid foot area were significant differences in four conditions(p<.05). Conclusion : The results of this study indicate that the use of baby carrier of sling for baby care were influenced postural responses of young women. Further work is recommended to find out the influences of various assistive devices for baby care.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.1
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• pp.94-100
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• 2017

Stress drain bias dependent current model is proposed for sub-70-nm p-channel metal-oxide semiconductor field-effect transistors (pMOSFETs) under drain-avalanche-hot-carrier (DAHC-) mechanism. The proposed model describes the both on-current and off-current degradation by using two device parameters: channel length variation (${\Delta}L_{ch}$) and threshold voltage shift (${\Delta}V_{th}$). Also, it is a simple and effective model of predicting reliable circuit operation and standby power consumption.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.2037-2042
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• 2003

The purpose of this research is to develop the model of turbulence modulation due to the presence of particles in various types of particle-laden flows. Available experimental data were surveyed and the dependence of turbulence modulation of carrier-phase on particle size, concentration and particle Reynolds number were examined. This study takes into account the effect of wake produced by particle, the drag between phases and the velocity gradient in the wake to estimate the production of turbulence. The model of turbulence modulation using the mixing length theory under the assumption of equilibrium flow is proposed. Numerical results show that the model is successful in predicting the characteristics of the particle-laden flow in various conditions both qualitatively and quantitatively.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.7
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• pp.406-412
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• 2013

A hybrid heat pump is under development with the goal of utilizing 120% of primary energy resources. A plate heat exchanger is added between the compressor and air-cooled condenser of an ordinary heat pump to heat water. For successful operation of the heat pump, it is necessary to develop a control algorithm under various operating conditions. As a virtual test bed for that purpose, a dynamic model has been developed, to simulate its dynamic behavior. It was modeled in transient one-dimensions, with varying phase lengths considered. The model was implemented in Matlab and Simulink. Simulation results were effectively applied to design a control algorithm. They also provided physical insight into how to design and operate the system.