• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.8
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• pp.43-49
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• 2009

This paper presents a routing mechanism to prolong the lifetime of error-prone wireless sensor networks. The proposed mechanism estimates the amount of energy consumption for communications and the expected residual energy in advance, which is based on the qualities of wireless links. Then, the proposed mechanism selects a path that is expected to have the most residual energy, and sends sensory data along the path. This mechanism reduces energy consumption caused by unnecessary retransmissions and distributes traffic evenly over the network owing to taking error rates into consideration, and extends energy depletion by selecting a path with the maximum of the minimal expected residual energy amounts. The experiment results show that the proposed mechanism prolongs network lifetime, compared to the existing methods.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.13 no.2
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• pp.140-146
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• 2013

In this paper, we describe a vision sensor-based driving algorithm for indoor automatic guided vehicles (AGVs) that facilitates a path tracking task using two mono cameras for navigation. One camera is mounted on vehicle to observe the environment and to detect markers in front of the vehicle. The other camera is attached so the view is perpendicular to the floor, which compensates for the distance between the wheels and markers. The angle and distance from the center of the two wheels to the center of marker are also obtained using these two cameras. We propose five movement patterns for AGVs to guarantee smooth performance during path tracking: starting, moving straight, pre-turning, left/right turning, and stopping. This driving algorithm based on two vision sensors gives greater flexibility to AGVs, including easy layout change, autonomy, and even economy. The algorithm was validated in an experiment using a two-wheeled mobile robot.

• The Journal of the Acoustical Society of Korea
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• v.4 no.2
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• pp.3-12
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• 1985

The surface intensity method is a relatively new tool which can identify the noise source or path and measure the radiation power. One microphone and one accelerometer are used in this new technique. In this study, this new technique has been used to measure the field transmission loss trough doors. The results of the experiment indicate that the surface intensity method produces reliable data and can be applied to the transmission loss measurement.

• The Journal of the Acoustical Society of Korea
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• v.4 no.2
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• pp.3.1-3.1
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• 1985

The surface intensity method is a relatively new tool which can identify the noise source or path and measure the radiation power. One microphone and one accelerometer are used in this new technique. In this study, this new technique has been used to measure the field transmission loss trough doors. The results of the experiment indicate that the surface intensity method produces reliable data and can be applied to the transmission loss measurement.

• 전기의세계
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• v.18 no.1
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• pp.11-14
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• 1969

This paper shows experimentally one method of preventing porcelain insulators from salt accident likely to be caused in the region of sea coast. In this experiment some results that, if a conductor barrier is inserted into the flash over discharge path which is wetted by salt dissolved water, the flash over voltage found to be raised up, were gotten. This results may be actually applied to suspension insulator or bushing to prevent them from salt accidents.

• The KIPS Transactions:PartD
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• v.12D no.5 s.101
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• pp.663-672
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• 2005

This Paper Proposes an approach that removes the redundancy of Path information and uses an inverted index, as an efficient way to store a large volume of XML documents and to retrieve wanted information from there. An XML document is decomposed into nodes based on its tree structure, and stored in relational tables according to the node type, with path information from the root to each node. The existing methods using path information store data for all element paths, which cause retrieval performance to be decreased with increased data volume. Our approach stores only data for leaf element path excluding internal element paths. As the inverted index is made by the leaf element path only, the number of posting lists by key words become smaller than those of the existing methods. For the storage and retrieval of U data, our approach doesn't require the XML schema information of XML documents and any extension of relational database. We demonstrate the better performance of on approach than the existing approaches within the scope of our experiment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.4
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• pp.1406-1423
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• 2014

Multi-mode device which combines multiple access technologies into a device will offer more cost-effective solution than a sole access implementation. Its concurrent multipath transfer (CMT) technology can transmit media flows over multiple end-to-end paths simultaneously, which is essential to select at least two paths from all available paths. At real networks, different paths are likely to overlap each other and even share bottleneck, which can weaken the path diversity gained through CMT. Spurred by this observation, it is necessary to select multiple independent paths as much as possible to avoid underlying shared bottleneck between topologically joint paths. Recent research in this context has shown that different paths with shared bottleneck can weaken the path diversity gained through CMT. In our earlier work, a grouping-based multipath selection (GMS) mechanism is introduced and developed. However, how to estimating the selection is still to be resolved. In this paper, we firstly introduce a Selection Correctness Index (SCI) to evaluate the correctness of selection results in actual CMT experiment. Therefore, this metric is helpful to discuss and validate the accuracy of the output paths. From extensive experiments with a realized prototype, the proposed scheme provides better evaluation tool and criterion in various network conditions.

• Korean Institute of Interior Design Journal
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• v.22 no.6
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• pp.212-219
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• 2013

This study uses a fashion shop facade design to track human gaze, find gaze frequency for gaze time for the gaze points along the path of sight, and expose the importance of facade design and figure out the value through theoretical systematization. Thus, this study employed the measurement method in physiological psychology which is sight-tracking device with eye-tracking to perform effective data evaluation. To find gaze frequency and study the contents to reflect on the facade, precedent study review, and case study of facade design to collect stimulants to be used in eye-tracking experiment were executed. And the eye-tracking experiment which traces the movement of eye[pupil] was performed. As the result of analyzing gaze frequency, The characteristics of such gaze path formation made the characteristics for gaze frequency even clearer. What was characteristic in the analysis result according to 'average value for gaze time' was that only 8 out of 2000 areas showed over 1 second of frequency and, and all other shoed less than 1 second of gaze time. This indicates that human sight endlessly jumps around, and that it 'Stay' where it has interest. This study found the average of the frequency of this 'Stay' in facade design. This study well presents the major points to add value to the design of the space of facade based on scientific measurement/analysis data obtained through visual understanding. Through such, this study is thought to be able to have a positive interaction with marketing by forming a theoretical background bringing utility to purchase environment and assisting in sales increase.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.5
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• pp.374-379
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• 2002

A new active muffler system has been developed and its superior performance on both noise reduction and engine torque increase is demonstrated with experiment. Main characteristic of the proposed muffler system is the use of destructive interference by transmission path difference of divided exhaust pipes to reduce major exhaust noise components thereby overcoming problems of other active exhaust noise control methods. The exhaust pipe is divided into two sections and joined again downstream. One divided pipe has a sliding mechanism to vary its length, which is controlled to make half wavelength transmission path difference for the major engine rpm frequency. In this system one divided pipe is used to control major rpm frequency and its Harmonics and another pipe is used to control noise component double the frequency of rpm. An after-market tuning muffler, which has very simple internal structure and minimal back pressure, is also installed to remove remaining wideband noise. To make the system to be small enough to be practical, conventional muffler is also installed and used in low rpm range and active muffler is only employed in high rpm range. Noise reduction of the proposed system is comparable to conventional passive muffler. The engine dynamo test has proved the proposed system can recover almost all the torque lost by conventional muffler.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.1
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• pp.105-112
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• 2014

The utilization of Wireless Ad Hoc Network which can build easily network using wireless device in difficult situation to build network is very good. However, it has security threat element because it transfers data by only forwarding of wireless devices. The measures against this should be prepared because damage by especially routing attack can affect the entire network. It is hard to distinguish malicious node and normal node among nodes composing network and it is not easy also to detect routing attack and respond to this. In this paper, we propose new method which detect routing attack and can respond to this. The amount of traffic in all nodes is measured periodically to judge the presence or absence of attack node on the path set. The technique that hides inspection packet to suspected node and transmits is used in order to detect accurately attack node in the path occurred attack. The experiment is performed by comparing SRAODA and SEAODV technique to evaluate performance of the proposed technique and the excellent performance can be confirmed.