• Journal of Positioning, Navigation, and Timing
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• v.11 no.4
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• pp.351-360
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• 2022

Autonomous vehicles require precise knowledge of their position, velocity and orientation in all weather and traffic conditions in any time. And, these information is effectively used for path planning, perception, and control that are key factors for safety of vehicle driving. For this purpose, a high precision GNSS technology is widely adopted in autonomous vehicles as a core localization and navigation method. However, due to the lack of infrastructure as well as cost issue regarding GNSS correction data communication, only a few high precision GNSS technology will be available for future commercial autonomous vehicles. Recently, a high precision GNSS sensor that is based on a Broadcast-RTK system to dramatically reduce network maintenance cost by utilizing the existing broadcasting network is released. In this paper, we present the performance test result of the broadcast-RTK-based commercial high precision GNSS receiver to test the feasibility of the system for autonomous driving in Korea. Massive measurement campaigns covering of Korea region were performed, and the obtained measurements were analyzed in terms of ambiguity fixing rate, integer ambiguity loss recovery, time to retry ambiguity fixing, average correction information update rate as well as accuracy in comparison to other high precision systems.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.539-543
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• 2005

The research presented in this paper enables real-time 3D modeling to help make construction processes ultimately faster, more predictable and safer. Initial research efforts used an emerging sensor technology and proved its usefulness in the acquisition of range information for the detection and efficient representation of static and moving objects. Based on the time-of-flight principle, the sensor acquires range and intensity information of each image pixel within the entire sensor's field-of-view in real-time with frequencies of up to 30 Hz. However, real-time working range data processing algorithms need to be developed to rapidly process range information into meaningful 3D computer models. This research ultimately focuses on the application of safer heavy equipment operation. The paper compares (a) a previous research effort in convex hull modeling using sparse range point clouds from a single laser beam range finder, to (b) high-frame rate update Flash LADAR (Laser Detection and Ranging) scanning for complete scene modeling. The presented research will demonstrate if the FlashLADAR technology can play an important role in real-time modeling of infrastructure assets in the near future.

• Tuberculosis and Respiratory Diseases
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• v.79 no.2
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• pp.53-57
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• 2016

Severe sepsis or septic shock is characterized by an excessive inflammatory response to infectious pathogens. Acute respiratory distress syndrome (ARDS) is a devastating complication of severe sepsis, from which patients have high mortality. Advances in treatment modalities including lung protective ventilation, prone positioning, use of neuromuscular blockade, and extracorporeal membrane oxygenation, have improved the outcome over recent decades, nevertheless, the mortality rate still remains high. Timely treatment of underlying sepsis and early identification of patients at risk of ARDS can help to decrease its development. In addition, further studies are needed regarding pathogenesis and novel therapies in order to show promising future treatments of sepsis-induced ARDS.

• Journal of The Korean Dental Society of Anesthesiology
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• v.14 no.1
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• pp.3-10
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• 2014

The inferior alveolar nerve (IAN) block is the most frequently used mandibular injection technique for achieving local anesthesia for restorative and surgical procedures. However, The IAN block does not always result in successful anesthesia, especially pulpal anesthesia. Lidocaine is used as a "standard" local anesthetic for the inferior alveolar nerve. Articaine recently joined Korean market as a form of dental cartridge. It has an advantage of superior diffusion through bony tissue. A variety of trial was performed to improve the success rate of inferior alveolar nerve block. In this review, the recent update related with inferior alveolar nerve block anesthesia will be discussed on the anatomical consideration, anesthetic agent, technique, and complications.

• Journal of the Korean Data and Information Science Society
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• v.13 no.1
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• pp.55-65
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• 2002

In this paper we present a Bayesian approach for determining an optimal maintenance policy following the expiration of warranty for a repairable system. We consider two types of warranty policies : non-renewing free replacement warranty (NFRW) and non-renewing pro-rata warranty (NPRW). The mathematical formula of the expected cost rate per unit time is obtained for NFRW and NPRW, respectively. When the failure time is Weibull distribution with uncertain parameters, a Bayesian approach is established to formally express and update the uncertain parameters for determining an optimal maintenance policy. We illustrate the use of our approach with simulated data.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.81-84
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• 2001

A real time optimization algorithm for fed-batch cultures of recombinant yeast to determine the optimal substrate feed rate profile has been developed. Its development involved four key steps: (1) development of reliable adaptive model. (2) development of optimization algorithm. (3) design of on-line model update algorithm to be incorporated into the optimization algorithm and (4) experimental validation. A recombinant Saccharomyces cerevisiae producing human parathyroid hormone (hPTH) was chosen as the model strain. It was found to be very successful in maintaining cell growth and galactose consumption at leigh levels, thus resulting in significant improvements in the productivity (up to 2.1 times) and intact hPTH concentration (up to 1.5 times) compared with the case of an intermittent glucose and galactose, or galactose feeding.

• International Journal of Aeronautical and Space Sciences
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• v.13 no.2
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• pp.260-265
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• 2012

Satellite devices for fine attitude control of the Science & Technology Satellite-2 (STSAT-2). Based on the mission requirements of STSAT-2, the conventional analog-type sun sensors were found to be inadequate, motivating the development of a compact, fast and fine digital sun sensor (FDSS). The FDSS uses a CMOS image sensor and has an accuracy of less than 0.03degrees, an update rate of 5Hz and a weight of less than 800g. A pinhole-type aperture is substituted for the optical lens to minimize its weight. The target process speed is obtained by utilizing the Field Programmable Gate Array (FPGA), which acquires images from the CMOS sensor, and stores and processes the image data. The sensor accuracy is maintained by a rigorous centroid algorithm. This paper describes the FDSS designs, realizations, tests and calibration results.

• Clinical and Experimental Pediatrics
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• v.53 no.5
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• pp.629-633
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• 2010

Pertussis is a highly contagious respiratory tract disease caused by $Bordetella$ $pertussis$ infection. The clinical manifestation of this infection can be severe enough to cause death. Although pertussis has been supposed to be a vaccine-preventable disease ever since the widespread vaccination of children against pertussis was started, since the 1990s, cases of pertussis and related fatalities are on the rise, especially in countries with high vaccination coverage. In Korea, there have been no deaths due to pertussis since 1990, and the vaccination rate continues to be approximately 94%. However, the number of pertussis cases reported to the Korea Center for Disease Control and Prevention has tended to increase in the 2000s, and in 2009, there was an obvious increase in the number of pertussis cases reported. This review aims to present the latest information about the pathogenesis, diagnosis, treatment, and prevention of pertussis.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.5
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• pp.767-774
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• 1990

Successive images can be reconstructed without great degradation by using one codebook in vector quantization, because statistics of successive images are sinilar. In this paper, we propose a method to update vector centroids in one slot of an image sequence and reconstruct images with the codebook replenished with the updated vector centroids. To remove the overhead required to transmit the updated vector centroids, we catagorize image blocks into changing blocks and nonchanging blocks, and then transmit only the labels of the changing blocks. Therefore, we can assign the remaining bits to the replenishment of a codebook. By the proposed method, almost the same image as the same image as the one reconstructed by LBG algorithm can be obtained and the bit rate can be reduced to below 0.5 bit/pixel.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.7
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• pp.720-727
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• 2009

This paper proposes a new integrated navigation system for a mobile robot in indoor environments. This system consists of five frameworks which are classified by function. This architecture can make the navigation system scalable and flexible. The robot can recover from exceptional situations, such as environmental changes, failure of entering the narrow path, and path occupation by moving objects, using the exception recovery framework. The environmental change can be dealt with using the probabilistic approach, and the problems with the narrow path and path occupation are solved using the ray casting algorithm and the Bayesian update rule. The proposed navigation system was successfully applied to several robots and operated in various environments. Experimental results showed good performance in that the exception recovery framework significantly increased the success rate of navigation. The system architecture proposed in this paper can reduce the time for developing robot applications through its reusability and changeability.