• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.7
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• pp.90-97
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• 1989

In this paper, we have taken the formation of two-dimension codeword named doubly-encoded code using the Reed-Solomon code, C1(32, 28) with minimum distance 5 and C2(32, 26) with minimum distance 7 and we have had computer simulation of these error correcting processes using modeled R-DAT (Rotationary Digital Audio Tape). As the result, the error rate per symbol has been decreased about 0.05 and on these processes, the newly developed digital signal processing technology such as erro correction using Berlekamp-Massey algorithm in frequency domain have been proven.

• Journal of Korean Institute of Industrial Engineers
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• v.31 no.3
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• pp.257-264
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• 2005

This paper suggests a heuristic algorithm for the clustering problem. Clustering involves grouping similar objects into a cluster. Clustering is used in a wide variety of fields including data mining, marketing, and biology. Until now there are a lot of approaches using Self-Organizing Feature Maps(SOFMs). But they have problems with a small output-layer nodes and initial weight. For example, one of them is a one-dimension map of k output-layer nodes, if they want to make k clusters. This approach has problems to classify elaboratively. This paper suggests one-dimensional output-layer nodes in SOFMs. The number of output-layer nodes is more than those of clusters intended to find and the order of output-layer nodes is ascending in the sum of the output-layer node's weight. We can find input data in SOFMs output node and classify input data in output nodes using Euclidean distance. We use the well known IRIS data as an experimental data. Unsupervised clustering of IRIS data typically results in 15 - 17 clustering error. However, the proposed algorithm has only six clustering errors.

• The Pure and Applied Mathematics
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• v.27 no.3
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• pp.137-155
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• 2020

Redundancy is commonly employed to improve system reliability. In most situations, components in the standby configurations are assumed statistically similar but independent. In many realistic models, all parts in standby are not treated as identical as they have different failure possibilities. The operational structure of the system has subsystem-1 with five identical components working under 2-out-of-5: G; policy, and the subsystem-2 has two units and functioning under 1-out-of-2: G; policy. Failure rates of units of subsystems are constant and assumed to follow an exponential distribution. Computed results give a new aspect to the scientific community to adopt multi-dimension repair in the form of the copula.

• Transactions on Electrical and Electronic Materials
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• v.11 no.2
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• pp.65-68
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• 2010

The operation principle of a traveling wave rotary type ultrasonic motor can be successfully applied to the fluidic transfer mechanism of the micro-pump. This paper proposes an innovative valveless micro-pump type that uses an extensional vibration mode of a traveling wave as a volume transportation means. The proposed pump consists of coaxial cylindrical shells that join the piezoelectric ceramic ring and metal body, respectively. In order to confirm the actuation mechanism of the proposed pump model, a numerical simulation analysis was implemented. In accordance with the variations in the exciting wave mode and pump body dimension, we analyzed the vibration displacement characteristics of the proposed model, determined the optimal design condition, fabricated the prototype pump from the analysis results and evaluated its performance. The maximum flow rate was approximately $595\;{\mu}L/min$ and the highest back pressure was 0.88 kPa at an input voltage of $130\;V_{rms}$. We confirmed that the peristaltic motion of the piezoelectric actuator was effectively applied to the fluid transfer mechanism of the valveless type micro pump throughout this research.

• International Journal of Advanced Culture Technology
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• v.3 no.1
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• pp.145-152
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• 2015

The article aims to apply a friction stir spot welding for producing the lap joint between AA5052 aluminum alloy and C11000 copper alloy. The dimension of the materials was 100 mm in length, 30 mm in width and 1.0 mm in thickness. The copper plate was set overlap the aluminum plate by 30 mm. The welding parameter was the rotating speed of 2500-4000 rpm, the pin inserting rate of 2-8 mm/min and the holding time of 6 sec. The mechanical properties test and the microstructure investigation were performed to evaluate the lap joint quality. The summarized results are as follows. The friction stir spot welding could produce effectively the lap joint between AA5052 and C11000 copper. Increase of the rotating speed and holding time directly affected to decrease the tensile shear strength of the lap joint. The optimized welding parameters in this study that indicated the tensile shear strength of 864 N was the rotating speed of 3500 rpm, the pin inserting rate of 6 mm/min and the holding time of 4sec. The experimental results also showed that the hardness of the weld metal was lower than that of the base materials.

• Structural Engineering and Mechanics
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• v.62 no.4
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• pp.465-475
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• 2017

Photovoltaic (PV) panels are used in high-rise buildings to convert solar energy to electricity. Due to the considerable energy consumption of high-rise buildings, applying PV technology is of great significance to energy saving. In the application of PV panels, one of the most important construction issues is the connection of the PV panel with the main structures. One major difficulty of the connection design is that the PV panel connection consists of two separate components with coupling and indeterminate dimension. In this paper, the gap element is employed in these two separated but coupled components, i.e., hook and catch. Topology optimization is applied to optimize and design the cross-section of the PV panel connection. Pareto optimization is conducted to operate the optimization subject to multiple load scenarios. The initial design for the topology optimization is determined by the common design specified by the Technical Code for Glass Curtain Wall Engineering (JGJ 102-2003). Gravity and wind load scenarios are considered for the optimization and numerical analysis. Post analysis is conducted for the optimal design obtained by the topology optimization due to the manufactory requirements. Generally, compared with the conventional design, the optimized connector reduces material use with improved structural characteristics.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.08a
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• pp.95-98
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• 2008

The vehicle has many technique change from The requirement of the safety the energy environment and convenience dimension is an enlargement toe. This is keeping changing the paradigm of the vehicle industry rapidly. The change to be technical such brought the intelligence of the former control device. And this organizes a sensor network among each systems and makes new traffic system. This paper a standard framework based on Sensor. We call it Vehicle Management System. The VMS used MOST network and It is able to make the stability of the component swap time or vehicle order the greatest.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.18.1-18.9
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• 2020

Background: Bone grafting has been considered the gold standard for hard tissue reconstructive surgery and is widely used for large mandibular defect reconstruction. However, the midface encompasses delicate structures that are surrounded by a complex bone architecture, which makes bone grafting using traditional methods very challenging. Three-dimensional (3D) bioprinting is a developing technology that is derived from the evolution of additive manufacturing. It enables precise development of a scaffold from different available biomaterials that mimic the shape, size, and dimension of a defect without relying only on the surgeon's skills and capabilities, and subsequently, may enhance surgical outcomes and, in turn, patient satisfaction and quality of life. Review: This review summarizes different biomaterial classes that can be used in 3D bioprinters as bioinks to fabricate bone scaffolds, including polymers, bioceramics, and composites. It also describes the advantages and limitations of the three currently used 3D bioprinting technologies: inkjet bioprinting, micro-extrusion, and laserassisted bioprinting. Conclusions: Although 3D bioprinting technology is still in its infancy and requires further development and optimization both in biomaterials and techniques, it offers great promise and potential for facial reconstruction with improved outcome.

• Geomechanics and Engineering
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• v.24 no.6
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• pp.545-557
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• 2021

Since the functionally graded materials (FGMs) are used extensively as thermal barriers in many of applications. Therefore, the current article focuses on studying and presenting dynamic responses of multilayer functionally graded (FG) deep beams placed in a thermal environment that is not addressed elsewhere. The material properties of each layer are proposed to be temperature-dependent and vary continuously through the height direction based on the Power-Law function. The deep layered beam is exposed to harmonic sinusoidal load and temperature rising. In the modelling of the multilayered FG deep beam, the two-dimensional (2D) plane stress continuum model is used. Equations of motion of deep composite beam with the associated boundary conditions are presented. In the frame of finite element method (FEM), the 2D twelve-node plane element is exploited to discretize the space domain through the length-thickness plane of the beam. In the solution of the dynamic problem, Newmark average acceleration method is used to solve the time domain incrementally. The developed procedure is verified and compared, and an excellent agreement is observed. In numerical examples, effects of graduation parameter, geometrical dimension and stacking sequence of layers on the time response of deep multilayer FG beams are investigated with temperature effects.

• Journal of Chest Surgery
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• v.54 no.6
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• pp.439-448
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• 2021

Remodeling is a commonly encountered term in the field of cardiothoracic surgery that is often used to describe various pathophysiological changes in the dimension, structure, and function of various cardiac chambers, including the aorta. Stanford type A or DeBakey type 1 aortic dissection (TAAD) is a perplexing pathologic condition that can present surgical teams with the need to navigate a maze of complex decision-making. Ascending or hemi-arch replacement leaves behind a significant amount of distal diseased aortic tissue, which might have a persistent false lumen or primary or secondary intimal tears (or communications between lumina), which can lead to dilatation of the aortic arch. Unfavorable aortic remodeling is a major cause of distal aortic deterioration after the index surgery. Cardiac surgeons are aware of post-surgical cardiac chamber remodeling, but the concept of distal aortic remodeling is still idealized. The contemporary literature from established aortic centers supports aggressive management of the residual aortic pathology during the index surgery, and with continuing technical advancements, endovascular stenting options are readily available for patients with TAAD or for complicated type B aortic dissection cases. This review discusses the pathophysiology and treatment options for favorable distal aortic remodeling, as well as its impact on mid- to long-term outcomes following TAAD repair.