• Smart Media Journal
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• v.11 no.10
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• pp.22-29
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• 2022

Voice interactions are particularly effective in applications targeting the digital underprivileged who are not proficient in the use of smart devices. However, applications based on open APIs are using voice signals only for short, fragmentary input and output due to the limitations of existing touchscreen-oriented UI and API provided. In this paper, we design a conversational voice interaction model for interactions between users and intelligent mobile/IoT applications and propose a keyword detection algorithm based on the edit distance. The proposed model and scheme were implemented in an Android environment, and the edit distance-based keyword detection algorithm showed a higher recognition rate than the existing algorithm for keywords that were incorrectly recognized through speech recognition.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.1
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• pp.1-10
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• 2001

In order to generate the gray scale image by the binary state imaging devices such as a digital printer, the gray scale image needs to be converted into the binary image by the halftoning techniques. This paper presents a new error diffusion technique to achieve the homogeneous dot distributions on the binary images. In this paper,'the minimum pixel distance'from the current pixel under binarization to the nearest minor pixel is defined first. Also, the gray levels of the input image are converted into a new variable based on the principal distance for the error diffusion. In the proposed method, the difference in the principal distances is utilized for the error propagation, whereas the gray level difference due to the binarization is diffused to the neighboring pixels in the existing error diffusion techniques. The quantization is accomplished by comparing the updated principal distance with the minimum pixel distance. In order to calculate the minimum pixel distance, MPOA(Minor Pixel Offset Array) is employed to reduce the computational loads and memory resources.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.8
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• pp.40-46
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• 2014

The development of the superconducting fault current limiter (SFCL) to apply into a power transmission system where makes larger fault current compared to the power distribution system has been performed. Among various SFCLs, the trigger-type SFCL is suitable for application into the power transmission system due to the effective reduction on power burden of the high temperature superconducting element (HTSC) for the larger fault current. To protect the power transmission line in the power grid, the distance relay, which decides to interrupt fault section where can be calculated by the measured voltage and current from sound grid, is one of important protective devices in the power transmission system. However, the operation of the distance relay from the impedance of the fault point on the transmission line is affected by the impedance of the trigger-type SFCL. Therefore, the analysis on the operational characteristics of distance relay considering the application of the SFCL is required. In this paper, the effect on the operation zones of the distance relay by the impedance of the SFCL in a power transmission system was analyzed through the PSCAD/EMTDC simulation.

• Journal of the Korean Institute of Gas
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• v.16 no.1
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• pp.15-21
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• 2012

An analysis was completed of the hazards distance of hydrogen accidents such as jet release, jet fire, and vapor cloud explosion(VCE) of hydrogen gas, and simplified equations have been proposed to predict the hazard distances to set up safety distance by the gas dispersion, fire, and explosion following hydrogen gas release. For a small release rate of hydrogen gas, such as from a pine-hole, the hazard distance from jet dispersion is longer than that from jet fire. The hazard distance is directly proportional to the pressure raised to a half power and to the diameter of hole and up to several tens meters. For a large release rate, such as from full bore rupture of a pipeline or a large hole of storage vessel, the hazard distance from a large jet fire is longer than that from unconfined vapor cloud explosion. The hazard distance from the fire may be up to several hundred meters. Hydrogen filling station in urban area is difficult to compliance with the safety distance criterion, if the accident scenario of large hydrogen gas release is basis for setting up the safety distance, which is minimum separation distance between the station and building. Therefore, the accident of large hydrogen gas release must be prevented by using safety devices and the safety distance may be set based on the small release rate of hydrogen gas. But if there are any possibility of large release, populated building, such as school, hospital etc, should be separated several hundred meters.

• Journal of Internet Computing and Services
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• v.15 no.6
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• pp.85-97
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• 2014

IoT devices that collect information for end users and provide various services like giving traffic or weather information to them that are located everywhere aim to raise quality of life. Currently, the number of devices has dramatically increased so that there are many companies and laboratories for developing various IoT devices in the world. However, research about IoT computing such as connecting IoT devices or management is at an early stage. A server node that manages lots of IoT device in IoT computing environment is certainly needed. But, it is difficult to manage lots of devices efficiently. However, anyone cannot surly know about how many servers are needed or where they are located in the environment. In this paper, we suggest a method that is a way to dynamic clustering IoT computing environment by logical distance among devices. With our proposed method, we can ensure to manage the quality in large-scale IoT environment efficiently.

• Science of Emotion and Sensibility
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• v.20 no.3
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• pp.89-96
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• 2017

This study developed a method which recognizes emotional interactions from the social distance by a beacon wearable device. The recognized interaction was evaluated by comparing with the cardiovascular synchrony from photoplethysmogram (PPG). The interaction was recognized when social distance was maintained for a certain period of time. The cardiovascular synchrony was estimated by correlation anaysis between beat per minute (BPM) from PPG. The maintenance time was determined by Mann-Whitney U test between the cardiovascular synchrony of interaction and non-interaction groups. Fifteen groups (2 persons per a group) participated in the experiment and they were asked to wear the beacon and PPG wearable devices in daily life. Experimental results showed that the interaction groups had more higher cardiovascular synchrony than non-interaction groups and the significant interaction time was determined to be 11 seconds (p=.045). Consequently, the real-time measurement and evaluation of the social network in real space was expected to be improved.

• Journal of Internet Computing and Services
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• v.9 no.4
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• pp.51-59
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• 2008

In wireless sensor networks, one of most common location detection methods that do not require additional devices such as GPS and ultrasonic sensor, is the location detection method based on received signal strength. However, measured received signal strength will fluctuate over time mainly due to physical radio channel characteristics between nodes, which subsequently will cause errors to measured distance between nodes. Since these contaminated distance data are utilized to detect the location of unknown node, there will be accumulated errors in the location of unknown node. In order to overcome the limitation of the location detection method based on received signal strength, we propose a location scheme in which reliability information of distance data as well as distance data between nodes are utilized to estimate the location of unknown node. Through simulation, it is shown that the proposed scheme can accomplish 30% capacity improvement.

• Journal of Internet Computing and Services
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• v.21 no.6
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• pp.71-79
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• 2020

In this paper, we propose a theft prevention technology based on beacon and smart device for smart stroller. The smart stroller has two Bluetooth devices. One is for data transmission and the other is for distance measurement as beacon. Thus, smart device uses a Bluetooth for strength level setting, manual locking and data transmission of smart stroller. Furthermore, smart device can do automatic locking of smart stroller using Bluetooth beacon when the stroller go further away from smart device. At this time, we apply a distance measurement algorithm and theft prevention algorithm with improved beacon distance measurement technique. To show usefulness of the proposed technology, we make a smart stroller and developed a smart device application. We did two distance measurement experiments and a theft prevention experiment with the proposed technology and the result shows 91.3% accuracy for theft prevention. Therefore, the proposed technology would be more usefulness technology for smart stroller.

• Journal of Korea Game Society
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• v.8 no.2
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• pp.85-96
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• 2008

Recently, research on augmented games as a new game genre has attracted a lot of attention. An augmented game overlaps virtual objects in an augmented reality(AR) environment, allowing game players to interact with the AR environment through manipulating real and virtual objects. However, it is difficult to release existing augmented games to ordinary game players, as the games generally use very expensive and inconvenient 'backpack' systems: To solve this problem, several augmented games have been proposed using mobile devices equipped with cameras, but it can be only enjoyed at a previously-installed location, as a ‘color marker' or 'pattern marker’ is used to overlap the virtual object with the real environment. Accordingly, this paper introduces an augmented game, called augmented galaga based on traditional well-known galaga, executed on mobile devices to make game players experience the game without any economic burdens. Augmented galaga uses real object in real environments, and uses scale-invariant features(SIFT), and Euclidean distance to recognize the real objects. The virtural aliens are randomly appeared around the specific objects, several specific objects are used to improve the interest aspect, andgame players attack the virtual aliens by moving the mobile devices towards specific objects and clicking a button of mobile devices. As a result, we expect that augmented galaga provides an exciting experience without any economic burdens for players based on the game paradigm, where the user interacts with both the physical world captured by a mobile camera and the virtual aliens automatically generated by a mobile devices.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.1
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• pp.7-14
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• 2013

Presently, there are many different technologies used for position detection. However, as signal-receiving devices operating in different locations must detect the precise position of objects located at long distances, it is essential to know the precise time at which an object's or a user's terminal device sends a signal. For this purpose, the existing time of arrival (ToA) technology is not sufficiently reliable, and the existing time difference of arrival (TDoA) technology is more suitable. If a TDoA-based electric surveillance system and other tracking devices fail to achieve precise time-synchronization between devices with separation distance operation, it is impossible to obtain correct TDoA values from the signals sent by the signal-receiving devices; this failure to obtain the correct values directly affects the location estimation error. For this reason, the technology for achieving precise time synchronization between signal-receiving devices in separation distance operation, among the technologies previously mentioned, is a core technology for detecting TDoA-based locations. In this paper, the accuracy of the proposed time synchronization and the measurement error in the TDoA-based location detection technology is evaluated. The TDoA-based location measurement error is significantly improved when using the proposed method for time-synchronization error reduction.