• Smart Structures and Systems
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• v.7 no.3
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• pp.229-240
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• 2011

Recent developments in Smart Structures with very large scale embedded sensors and actuators have introduced new challenges in terms of data processing and sensor fusion. These smart structures are dynamically classified as a large-scale system with thousands of sensors and actuators that form the musculoskeletal of the structure, analogous to human body. In order to develop structural health monitoring and diagnostics with data provided by thousands of sensors, new sensor informatics has to be developed. The focus of our on-going research is to develop techniques and algorithms that would utilize this musculoskeletal system effectively; thus creating the intelligence for such a large-scale autonomous structure. To achieve this level of intelligence, three major research tasks are being conducted: development of a Bio-Inspired data analysis and information extraction from thousands of sensors; development of an analytical technique for Optimal Sensory System using Structural Observability; and creation of a bio-inspired decision-making and control system. This paper is focused on the results of our effort on the first task, namely development of a Neuro-Morphic Engineering approach, using a neuro-symbolic data manipulation, inspired by the understanding of human information processing architecture, for sensor fusion and structural diagnostics.

• Journal of Korean Neurosurgical Society
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• v.60 no.6
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• pp.755-762
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• 2017

Objective : The purpose of this study is to describe the detailed surgical technique and short-term clinical and radiological outcomes of lateral lumbar interbody fusion (LLIF) and in situ lateral screw fixation using a conventional minimally invasive screw fixation system (MISF) for revision surgery to treat rostral lumbar adjacent segment disease. Methods : The medical and radiological records were retrospectively reviewed. The surgery was indicated in 10 consecutive patients with rostral adjacent segment stenosis and instability. After the insertion of the interbody cage, lateral screws were inserted into the cranial and caudal vertebra using the MISF through the same LLIF trajectory. The radiological and clinical outcomes were assessed preoperatively and at 1, 3, 6, and 12 months postoperatively. Results : The median follow-up period was 13 months (range, 3-48 months). Transient sensory changes in the left anterior thigh occurred in 3 patients, and 1 patient experienced subjective weakness; however, these symptoms normalized within 1 week. Back and leg pain were significantly improved (p<0.05). In the radiological analysis, both the segmental angle at the operated segment and anterior disc height were significantly increased. At 6 months postoperatively, solid bony fusion was confirmed in 7 patients. Subsidence and mechanical failure did not occur in any patients. Conclusion : This study demonstrates that LLIF and in situ lateral screw fixation may be an alternative surgical option for rostral lumbar adjacent segment disease.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.2
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• pp.16-28
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• 2000

In this paper, we propose a navigation algorithm for a mobile robot, which is intelligently searching the goal location in unknown dynamic environments using an ultrasonic sensor. Instead of using "sensor fusion"method which generates the trajectory of a robot based upon the environment model and sensory data, "command fusion"method is used to govern the robot motions. The major factors for robot navigation are represented as a cost function. Using the data of the robot states and the environment, the weight value of each factor is determined for an optimal trajectory in dynamic environments. For the evaluation of the proposed algorithm, we peformed simulations in PC as well as real experiments with ZIRO. The results show that the proposed algorithm is apt to identify obstacles in unknown environments to guide the robot to the goal location safely.

• Journal of KIISE
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• v.43 no.12
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• pp.1365-1375
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• 2016

One of the most important capabilities for autonomous service robots working in living environments is to recognize and understand the correct context in dynamically changing environment. To generate high-level context knowledge for decision-making from multiple sensory data streams, many technical problems such as multi-modal sensory data fusion, uncertainty handling, symbolic knowledge grounding, time dependency, dynamics, and time-constrained spatio-temporal reasoning should be solved. Considering these problems, this paper proposes an effective dynamic context management and spatio-temporal reasoning method for intelligent service robots. In order to guarantee efficient context management and reasoning, our algorithm was designed to generate low-level context knowledge reactively for every input sensory or perception data, while postponing high-level context knowledge generation until it was demanded by the decision-making module. When high-level context knowledge is demanded, it is derived through backward spatio-temporal reasoning. In experiments with Turtlebot using Kinect visual sensor, the dynamic context management and spatio-temporal reasoning system based on the proposed method showed high performance.

• Journal of Digital Convergence
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• v.20 no.4
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• pp.575-584
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• 2022

The purpose of this study is to derive interaction types that appear variously in immersive contents through John Dewey's empirical theory, and to explore how the derived types are delivered in real cases. For this reason, two cases of the National Museum of Korea 'Immersive Digital Gallery' and 'Arte Museum Jeju' were analyzed through interaction types derived from the empirical theory. The interaction types derived based on the experience theory are the elements of 'multi-sensory', 'simultaneous experience' and 'sensory expansion'. In both cases, these types appear connected rather than grafted one by one in common. In one direction, 'multi-sensory' leads to 'sensory expansion', and in two directions, 'simultaneous experience' leads to 'sensory expansion'. As such, the core types of communication between technology and humans are not delivered one by one, but a cycle of interaction is formed in multiple ways. Therefore, it can be seen that the interaction type of immersive contents is expanded step by step by fusion of various senses and experiences in various fields, rather than a 1:1 partial delivery method. Based on this, it will be necessary to study how types are expanded and how viewers are affected when interaction is implemented in immersive contents in the future.

• Food Science and Biotechnology
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• v.16 no.3
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• pp.329-336
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• 2007

Caking has been a serious problem in food, feed, pharmaceutical, and related industries, where dry powdered materials are produced and/or utilized. Caking of dry food powders occurs when water is redistributed or absorbed by the powders during processing and storage. The powders become sticky when their surfaces are mobilized by water, resulting in inter-particle binding, formation of clusters, and inter-particle fusion, which lead to caking. As a result of caking, the solubility of the powdered materials may decrease, lipid oxidation and enzymatic activity may increase, and sensory qualities such as flavor and crispness may deteriorate. Caking may also lead to microbial growth. For consumers, caking of powder products is a sign of poor quality and possible food safety problems. This paper provides a review of factors affecting caking, caking mechanisms, and analysis of caking based on previous studies.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1898-1899
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• 2011

In this paper, we propose an obstacle avoidance algorithm for a network-based autonomous mobile robot. The obstacle avoidance algorithm is based on the VFH (Vector Field Histogram) algorithm and delay-compensative methods with the VFH algorithm are proposed for the network-based robot that is a unified system composed of distributed environmental sensors, mobile actuators, and the VFH controller. Firstly, the compensated readings of the sensors are used for building the polar histogram of the VFH algorithm. Secondly, a sensory fusion using the Kalman filter is proposed for the localization of the robot to compensate both the delay of the readings of an odometry sensor and the delay of the readings of the environmental sensors. The performance enhancements of the proposed obstacle avoidance algorithm from the viewpoint of efficient path generation and accurate goal positioning are also shown in this paper through some simulation experiments by the Marilou Robotics Studio Simulator.

• Journal of Korean Neurosurgical Society
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• v.41 no.3
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• pp.207-209
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• 2007

We present an elderly patient with unilateral foraminal stenosis treated by isthmus resection. An 83-year-old female could not walk due to severe leg pain along right L5 sensory dermatome. Despite the laminotomy for spinal stenosis on the right side at the L4-5 level, her leg pain did not improve. Careful review of computed tomography scans and coronal source images of magnetic resonance myelography revealed foraminal stenosis on the right side at the L5 vertebra. Because of medical problem, she underwent isthmus resection on the right side at the L5 level instead of total facetectomy and fusion. After surgery, her leg pain was markedly improved. Isthmus resection showed successful result for this medically compromised elderly patient with unilateral foraminal stenosis.

• Journal of Korean Neurosurgical Society
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• v.46 no.5
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• pp.505-510
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• 2009

The possible causes of Brown-S$\acute{e}$quard Syndrome (BSS) have been frequently observed with spinal trauma and extramedullary spinal tumors, but the cervical disc herniation to cause BSS is rare. The authors present five cases of patients who were diagnosed with BSS resulting from cervical disc herniation, and the results of the literature in view of their distinctive symptoms and clinical outcomes. Postoperatively, the patients showed complete or almost complete recovery from their motor and sensory deficits. On the basis of our cases, it is important to diagnose it early by cervical magnetic resonance imaging, especially in the absence of the typical symptoms of cervical disc herniation or other obvious etiology of extremity numbness. Immediate surgical treatment is also essential for a favorable functional neurological recovery.

• Annals of Clinical Neurophysiology
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• v.1 no.2
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• pp.112-117
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• 1999

Background : Posterior tibial nerve somatosensory evoked potentials (PTSEP) have cortical potentials on primary sensory area of foot around 40 msec. The direct cortical recordings of the cortical potentials shows high voltage positive wave on medial hemisphere, especially on paracentral lobule (PCL). However, it is so difficult to record the potential directly on PCL that the cortical potential of PTSEP is not well understood. We investigated the cortical potential of PTSEP on subdural electrodes. Methods : We recorded cortical potentials to posterior tibial nerve stimulation on subdural electrodes which were on medial hemisphere near PCL in 15 intractable neocortical epilepsy patients. The numbers of subdural electrodes were 8 in 10 subjects ($1{\times}8array$) and 16 in 5 subjects ($2{\times}8arrays$). Seven subjects had three-dimensional imaging fusion (3D-fusion) of MRI and the electrodes using Analyze program. We investigated the amplitude, latency, polarity, and phase of the waves regarding location. Results : The waves had maximal amplitude on PCL in 4 subjects, precuneus in 1, cingulate gyrus nearest to PCL in 2 among 7 subjects with 3D-fusion. Also the electrodes were located on posterior area of PCL (2 out of 2 subjects with more than two electrodes put on PCL in 3D-fusion) and superior area of it (5 out of 5 subjects with $2{\times}8arrays $). All the high (more than 20 uV) amplitude around 40msec had positive polarity in 7 subjects. The phase reversals were detected between the electrodes with the highest amplitude and the just posterior (2 subjects) or anterior (6 subjects) located electrodes. The just posterior located electrodes had sharper phase reversal than the anterior one. Conclusion : PTSEP might have maximal amplitude of cortical potentials on the more superior and posterior area of PCL. The highest amplitude potential has positivity. The wave with maximal amplitude could have phase reversal of cortical potentials with surrounding electrodes, especially shaper with posterior part than with anterior one.