• Journal of Satellite, Information and Communications
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• v.10 no.2
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• pp.86-89
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• 2015

Formula acoustic characteristics of the room with a double layer, are compared through simulation and actual measurement. The rear area of the under- balcony speakers will cause a delay difference between the main speaker. In the mid / bass parts do not generate sufficient pressure is lowered and comb-Filtering phenomenon occurs significantly. The lower right area of the under- balcony speakers and speaker distance is the sound pressure of the under- balcony speakers to around 2 ~ 3m bigger than the main speakers and the sound image matches the pulpit is broken. Also, under area is more than 5 ~ 6m from the balcony outside speakers and causes differ by more than 10dB lower than the under- balcony speakers depending on the local laws of Translator wins Well, the main speaker at mid / high frequency sounds do not enter the sound pressure variations will drop by a significant. Appropriate arrangement and the output of the speaker according to the position under the balcony, and output of the main speakers are requested to minimize this problem sound. The proper sound design direction for the under- balcony speakers must be presented in order to improve the lower balcony area more pleasant acoustic environment.

• Proceedings of the KIEE Conference
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• 2006.05a
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• pp.74-77
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• 2006

This research is focused on the development of GIS Diagnostic SYSTEM to prevent accidents beforehand by inspecting the internal defects of GIS (Gas Insulated Switchgear) which is a main power-facility for substations. GIS Diagnostic SYSTEM is categorized as 'Real time on-line test type' and 'Portable test type' depending on the types of testing, it uses PD(partial discharge) which mostly incurs in GIS internal defects, to inspect. As of now, mostly foreign equipments are imported for use due to the lack of the technology localization, and these are installed and operated on only some parts of highly-graded GIS power-facilities such as in 76skv or 345kv for its being expensive. Furthermore, other than foreign equipments being costly, it also has a weak point of very long unavailability in case of Diagnostic system break-down while using, because it takes a comparatively long period of corrective maintenance precesses. We have localized to develop personal real-time multi -functional GIS Diagnostic system which can test on all GIS power-facility comprehensively and economically therefore overcome all these problems mentioned above, a market expansion is expected from the decrease of price and replacing the import equipments in the future. As the equipment was developed to be Personal for the simple ways of installing and utilizing, it can be operated without any complex cable installation like other existing GIS Diagnostic system requires, therefore also decrease the cost of cable installation.

• KIPS Transactions on Computer and Communication Systems
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• v.6 no.9
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• pp.369-376
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• 2017

Recently, an RSSI-based fingerprinting localization technology has been widely used in indoor location-based services. In the conventional fingerprinting method, as many APs as possible are used to increase the accuracy of location estimation. In another study, a part of APs having the strongest RSSI signal intensity are selected and used to reduce the time spent for positioning. However, it does not reflect the influence of RSSI occurred from the changes of the surrounding environments such as human movement or moving obstacles in a real environment. The environmental changes may cause the difference between the predicted RSSI signal strength value and the measured value, and thus occur an unpredictable error in the position estimation. Therefore, in order to mitigate the error caused by environmental factors, it is necessary to select APs suitable for indoor positioning estimation considering the changes in the surrounding environments. In this paper, we propose a method to select stable APs considering the influence of surrounding environments and derive a suitable positioning algorithm. In addition, we compare and analyze the performance of the proposed method with that of the existing AP selection methods through experiments.

• Nuclear Engineering and Technology
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• v.6 no.4
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• pp.231-237
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• 1974

For detection and localization of leaks in closed vessels or pipes carrying liquid flow, $^{51}$ Cr-EDTA and $^{51}$ Cr-DTPA were synthesized and, the column and batch equilibrium experiments were carried out. In the column experiment, the recovery of $^{51}$ Cr-EDTA is 100% in quartz sand and 80.9% in steel sawdust, and that of $^{51}$ Cr-DTPA is 77.4% in quartz sand and 6.4% in steel sawdust. The recovery curve. $^{51}$ Cr-DTPA system in steel sawdust does not show a certain plateau, exceptionally. In general, $^{51}$ Cr-EDTA is adsorbed less than $^{51}$ Cr-DTPA. In the batch equilibrium experiment, the distribution coefficients (Kd) and effect of pH were investigated by using quartz sand, montmorillonite, steel sawdust, and mixed cement raw material as media. In general, the Kd values for $^{51}$ Cr-EDTA are lower than that of $^{51}$ Cr-DTPA. The Kd values for $^{51}$ Cr-EDTA are almost zero at pH 6.0, 7.0, and 8.0.

• Journal of Digital Convergence
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• v.12 no.12
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• pp.129-137
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• 2014

The purpose of this study is to understand major factors of site selection of convenience stores in Busan and Gyeong-nam Region. This will be done by analyzing correlations of sale, profit and localization factors and choosing the major correlation factors out of them and carrying out regression analysis to analyze each factor's influence extent. the competition factor : It is shown that the competition factor has significant result with the sale and the profit and the effect of that is proved the biggest among all location requirements. Therefore, the competition factor is the most important factors above all. By providing recently standards and implications of site selection of stores, this study suggests a guideline for site selection not only to prep entrepreneurs and store developers but also prep entrepreneurs of retail store.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.5C
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• pp.726-736
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• 2004

In this paper, we proposed a new scalar multiplier structure needed for an elliptic curve cryptosystem(ECC) over the standard basis in GF(2$^{163}$ ). It consists of a bit-serial multiplier and a divider with control logics, and the divider consumes most of the processing time. To speed up the division processing, we developed a new division algorithm based on the extended Euclid algorithm. Dynamic data dependency of the Euclid algorithm has been transformed to static and fixed data flow by a localization technique, to make it independent of the input and field polynomial. Compared to other existing scalar multipliers, the new scalar multiplier requires smaller gate counts with improved processor performance. It has been synthesized using Samsung 0.18 um CMOS technology, and the maximum operating frequency is estimated 250 MHz. The resulting performance is 148 kbps, that is, it takes 1.1 msec to process a 163-bit data frame. We assure that this performance is enough to be used for digital signature, encryption/decryption, and key exchanges in real time environments.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.182-184
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• 2009

FlexRay is a new standard of network communication system which provides a high speed serial communication, time triggered bus and fault tolerant communication between electronic devices for future automotive and ship applications. FlexRay communication controller(CC) is the core of the FlexRay protocol specification. In this paper, we first design the FlexRay CC protocol specification and function parts using SDL(Specification and Description Language). Then, the system is re-designed using Verilog HDL based on the SDL source. The FlexRay CC system was synthesized using Samsung $0.35{\mu}m$ technology. It is shown that the designed system can operate in the frequency range above 80 MHz. In addition, to show the validity of the designed FlexRay system, the FlexRay system is combined with sound source localization system in Robot applications. The combined system is implemented using ALTERA Excalibur ARM EPXA4F672C3. It is shown that the implemented system operates successfully.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.3
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• pp.210-216
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• 2016

This paper presents a novel collision avoidance technique for mobile robots based on omni-directional vision simultaneous localization and mapping (SLAM). This method estimates the avoidance path and speed of a robot from the location of an obstacle, which can be detected using the Lucas-Kanade Optical Flow in images obtained through fish-eye cameras mounted on the robots. The conventional methods suggest avoidance paths by constructing an arbitrary force field around the obstacle found in the complete map obtained through the SLAM. Robots can also avoid obstacles by using the speed command based on the robot modeling and curved movement path of the robot. The recent research has been improved by optimizing the algorithm for the actual robot. However, research related to a robot using omni-directional vision SLAM to acquire around information at once has been comparatively less studied. The robot with the proposed algorithm avoids obstacles according to the estimated avoidance path based on the map obtained through an omni-directional vision SLAM using a fisheye image, and returns to the original path. In particular, it avoids the obstacles with various speed and direction using acceleration components based on motion information obtained by analyzing around the obstacles. The experimental results confirm the reliability of an avoidance algorithm through comparison between position obtained by the proposed algorithm and the real position collected while avoiding the obstacles.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.8 s.111
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• pp.767-772
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• 2006

The receiver of this paper is Dual-band monopulse type for prototype of tracking radar. Localization of radar technology is an issue of SamsungThales and go into development. Dual-band radar in comparison with Single-band radar requires higher cost and power consumption but there are many advantages of dealing with jamming, detection range, image signal rejection, cloud-rain influence, clutter, resolution. The receiver is comprised of X-band RF head module, Ka-band RF head module and common IF module. Each signal of X-band and Ka-band is selected by the switch in If module. Phase shifter in IF module of local stage controls the phase of sum, azimuth, elevation channel. In the test result, gain is $40{\pm}3 dB$, isolation of transmitter/receiver is 39 dBc, dynamic range is 110 dB and noise figure of each channel is 4.5dB and 6.9dB.

• Journal of Agricultural Extension & Community Development
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• v.8 no.1
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• pp.133-142
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• 2001

The objectives of this study were 1) to review the current status of cooperative extension services in Japan, and 2) to draw implications for improving Korean agricultural extension system. Faced with various problems since its localization of extension services in 1997, Korean agricultural extension needs to be improved and strengthened in order to continually achieve the national goals of food production, balanced national development and preservation of environment, at the same time to meet increasing needs of farmers. The results of the study revealed the major characteristics of agricultural extension services in Japan as follows; 1) Each agricultural extension centers were administratively and technically coordinated by the prefectural (provincial) government, 2) There were 11 public corporations with agricultural extension functions under the MAFF(Ministry of Agricultural Forestry and Fisheries) financed by government subsidies 3) Agricultural experiment stations at provincial level were responsible for developing agricultural innovations for farmers' adoption, 4) The functions and operation of the agricultural extension centers were independent from the local agricultural administration. Some of the implications drawn from the study were as follows; 1) In order to accomplish major objectives of agricultural extension services in Korea legal status of agricultural extension centers should be changed from city/county to provincial government, 2) It would be desirable to establish public corporations concerned with agricultural extension under the Rural Development Administration, 3) Provincial Rural Development Administration should be reinforced in terms of applied farming research and diffusion of new technology, 4) Agricultural extension centers should be independent from administrative function and be separated from administration at the city/county level.