• Journal of the Korean Institute of Telematics and Electronics
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• v.3 no.1
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• pp.18-23
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• 1966

An experimental study of a steel plate thickness gauge by means of the measurements of backscatered gamma-rays has been carried out. The difference between this and other methods is that this method does not include any shilding matterials in the detecting probe, because the primary radiations and the backscattered radiations are detected simultaneously by an NaI (TI) scintillating crystal, and the activity of the Co-60 source used is low enough. In this thickness gauge, the thickness of the steel plates can be read directly on the counting ratemeter scale. The optimum conditions in the source-to-detector distance, window width of the analyzer, energy and strength of the gamma-ray source were found experimentally. The results have shown that the accuracy of the gauge was about $\pm$3% in the range of 3 to 8mm thickness. This gauge can be used to detect the pits or corrosions on the inner walls of the steel pipes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.276-279
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• 2009

Is introducing ship automation system for the safety of ship and work environment mend recently. Is endeavoring for sea safety and fire at sea prevention solidifying control of standard technology and safety supervision aspect in IMO but sea accident and ship fire are happening continuously. Because using Robot in artistic talent of ship in this treatise, studied that correspond to Risk and manage. Attach fire perception sensor for Robot's Risk confrontation, and because using infrared rays sensor, TOUCH SWITCH, sound perception sensor, gas perception sensor, light perception sensor that is threaded in Robot and is achieved, controlled Robot, and establish Low-High value the speed of sound output use and DC MOTOR and COM SEN of when indicate Risk confrontation to Robot and establish Robot's Risk confrontation administration action.

• The Journal of the Acoustical Society of Korea
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• v.38 no.4
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• pp.467-475
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• 2019

A high-intensity ultrasound wave generates acoustic streaming and acoustic radiation forces when propagating through a medium. An acoustic radiation force generated in a three-dimensional space can produce a solid tactile sensation, delivering spatial information directly to the human skin. We placed 154 ultrasound transmit elements with a frequency of 40 kHz on a concave circular dish, and generated an acoustic radiation force at the focal point by transmitting the ultrasound wave. To feel the tactile sensation better, the transmit elements were excited by sine waves whose amplitude was modulated by a 60 Hz square wave. As an application of ultrasonic tactile sensing, a region where tactile sense is formed in the air is used as an indicator for the position of the hand. We confirmed the utility of ultrasonic tactile feedback by implementing a system that provides the number of fingers to a machine by receiving the shape of the hand at the focal point where the tactile sense is detected.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.11
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• pp.481-492
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• 2023

This study explores how to build a Korean dataset to extract information from text using generative large language models. In modern society, mixed information circulates rapidly, and effectively categorizing and extracting it is crucial to the decision-making process. However, there is still a lack of Korean datasets for training. To overcome this, this study attempts to extract information using text-based zero-shot learning using a generative large language model to build a purposeful Korean dataset. In this study, the language model is instructed to output the desired result through prompt engineering in the form of "system"-"instruction"-"source input"-"output format", and the dataset is built by utilizing the in-context learning characteristics of the language model through input sentences. We validate our approach by comparing the generated dataset with the existing benchmark dataset, and achieve 25.47% higher performance compared to the KLUE-RoBERTa-large model for the relation information extraction task. The results of this study are expected to contribute to AI research by showing the feasibility of extracting knowledge elements from Korean text. Furthermore, this methodology can be utilized for various fields and purposes, and has potential for building various Korean datasets.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.10
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• pp.311-322
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• 2014

IoT(Internet of Things) is a concept of connected internet pursuing direct access to devices or sensors in fused environment of personal, industrial and public area. In IoT environment, it is possible to access realtime data, and the data format and topology of devices are diverse. Also, there are bidirectional communications between users and devices to control actuators in IoT. In this point, IoT is different from the conventional internet in which data are produced by human desktops and gathered in server systems by way of one-sided simple internet communications. For the cloud or portal service of IoT, there should be a file management framework supporting systematic naming service and unified data access interface encompassing the variety of IoT things. This paper implements a DB-based virtual file system maintaining attributes of IoT things in a UNIX-styled file system view. Users who logged in the virtual shell are able to explore IoT things by navigating the virtual file system, and able to access IoT things directly via UNIX-styled file I O APIs. The implemented virtual file system is lightweight and flexible because it maintains only directory structure and descriptors for the distributed IoT things. The result of a test for the virtual shell primitives such as mkdir() or chdir() shows the smooth functionality of the virtual file system, Also, the exploring performance of the file system is better than that of Window file system in case of adopting a simple directory cache mechanism.

• 한국체육학회지인문사회과학편
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• v.58 no.6
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• pp.449-459
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• 2019

The purpose of this study is to identify how postural mechanics affects postural control on balance and stability by using frequency analysis technique from the kinematic data acquired during the one leg standing posture. For this purpose, the experimental group consisted of two groups, the normal group (n=6) and the national Gymnastics group (n=6). Displacement data of CoP were analyzed by frequency analysis of rambling (RM) and trembling (TR) by FFT signal processing. As a results, there was a significant difference in evaluating the stabilization index between the two groups with the eyes open and closed one leg stnading (p <.05). The cause of the difference was found to be the output of the maximum amplitude of RM (f1) and TR (f2) (p <.05). In particular, in the low frequency RM of 8-9 Hz, which is a natural frequency of signal wave involved in postural feedback feedback, the main frequency appeared to be performs the exercise mechanism of stable brain posture control. And in the high frequency TM of 120-135 Hz, it is considered that the adaptation of the reflective muscle response is minimized to minimize posture shaking. In conclusion, this study provides evidence for the intrinsic main frequencies according to the postural control ability which affects the CNS in one leg standing.

• Journal of Bio-Environment Control
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• v.4 no.1
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• pp.50-58
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• 1995

These studies were carried out to develop a system for non -destructive and continuous measurement of fresh weight and to analyse the growth response of leaf lettuce under the different nutrient solution and light condition with this system. The developed measurement system was consisted of four load cells and a microcomputer. The output from the system was highly positive correlation with the plant fresh weight above the surface of the hydroponic solution. The top fresh weight of plant could be measured within the error $\pm$ 1.0g in the range of 0 - 2000g. The top fresh weight of leaf lettuce increased 44 times at 18th day after transferring to the nutrient solution, and the maximum growth rate was observed at 13th day after transferring. The growth rate was 10.7- 29.6% per day during 18 days. Optimum concentration of the nutrient solution for the growth of lettuce was 1.4 - 2.2 mS/cm of EC level. When the light condition was changed from dark to light, the fresh weight was temporarily decreased, but the fresh weight increased under the opposite condition. Top fresh weight of leaf lettuce in the darkness normally increased within 12 hours after darkness treatment, and then slowly increased until 78 hours under continuous dark condition. After that times, the fresh weight began to decrease.