• Journal of Biosystems Engineering
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• v.24 no.4
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• pp.325-334
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• 1999

The aim of this study was to present a groundwork for development of a sorting system of peeled garlics using machine vision. Images of various garlic samples such as sound, partially defective, discolored, rotten and un-peeled were obtained with a B/W machine vision system. Sorting factors which were based on normalized histogram and statistical analysis(STEPDISC Method) had good separability for various garlic samples. Bayes discriminant function and neural network sorting algorithms were developed with the sample images and were experimented on various garlic samples. It was showed that garlic samples could be classified by sorting algorithm with average sorting accuracies of 88.4% by Bayes discriminant function and 93.2% by neural network.

• Speech Sciences
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• v.14 no.4
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• pp.213-220
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• 2007

This study investigates the voice quality including F0, jitter, shimmer, and NHR for the children with cochlear implant (CI group) and those with normal hearing (NH group). The CI group was further classified two sub-groups depending upon the time of surgery (i.e. under four years vs. over four years). Three corner vowels (e.g. /a/, /i/, /u/) with extended vocalization were used and analyzed with Multi-Dimensional Voice Program (Kay Elemetrics, Model 4300). The statistics were made in two independent sample t-test with SPSS 11.5. The results can be summarized as follows: (1) The children with cochlear implanted before 4 years of age had very similar data with the NH group except for the vowel /a/. (2) The children with cochlear implanted after 4 years of age, however, indicated significant differences in Fo (/a/, /i/, /u/), Jitter (/e/), shimmer (/a/, /i/, /u/) and NHR(/a/) in all three vowels. It is concluded that the early CI surgery and the early intervention would be very important to maintain better voice quality.

• Journal of Electrical Engineering and Technology
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• v.1 no.1
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• pp.16-22
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• 2006

Selective ground relays (SGRs) are useful fur distinguishing a faulted feeder from the sound feeders in ungrounded systems. However, they sometimes mis-operate due to human or device errors. Particularly, the reversed polarity of zero-sequence current transducers (ZCTs) is the most frequent cause of mis-operation. This paper presents a modified SGR for reducing the probability of mis-operations caused by the reversed polarity of ZCTs. The modification is achieved by introducing an adaptive time delay, which depends on the magnitude of the zero-sequence current and the phase angle deviation from the reference. The modified SGR was successfully demonstrated on a sample ungrounded system without mis-operation.

• MALSORI
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• no.19_20
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• pp.43-57
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• 1990

The teaching of pronunciation is one of the areas in which linguistic phonetics can play an extremely useful role. This paper is concerned with the application of the results of my phonetic research to the actual teaching of Korean standard pronunciation with special reference to speech rhythm. It has been found that Korean words and utterances of various lengths are pronounced in standard Korean with one of the four main rhythmic patterns, each containing a strong stress. Unless we get the rhythmic patterns right in pronouncing Korean words and utterances, therefore, the resulting pronounciation is bound to sound dialectal or incorrect and in many instances even unintelligible to listeners. Hence the undeniable need to devise a useful technique to teach the Korean speech rhythm in a systematic way. In this paper each of the four main rhythmic patterns is presented and elaborated with sample examples taken from the living Korean. It is hoped that these examples of words and utterances can be used at the same time as useful pronunciation drill material not only for Koreans with dialectal background but also for foreign learners of Korean.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.594-599
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• 2000

Two basic acoustic quantities, the characteristic impedances and the propagation constants, of the two different ultra lightweight concrete absorbers were examined with impedance tube method. A transmission loss was tested and compared with theoretical values. The results show that these kinds of sample have proper sound absorption and transmission loss capabilities. It means that they can be used in various fields where noise proof is needed.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.168-171
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• 1997

The purpose of this study is the development of PBL(problem-based learning) system using visual C++5.0 as a window-based application program. A patient who complains of weight loss was used in PBL case. Initial frame is made by dialog-based in MFC(microsoft foundation class). Also, sample medical images are composed of ultra-sound, chest PA, Thyroid scan, otherwise. we will make this program as CD-ROM and the internet application or computer assisted learning and continuous medical education.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.7
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• pp.503-509
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• 2015

Based on ISO 7235, an experimental setup to measure the acoustic performance of splitter type dissipative silencers was fabricated. The length of each duct, sound source, microphone locations, modal filter, and anechoic termination were considered in the design of this setup. The modal filter is a particularly important factor because it affects the limit of measurement. The effects of number of splitters, absorptive material density, perforate plate, and media on the noise reduction of the sample silencers were experimentally investigated. The experimental results show that the insertion loss of a silencer with media, high perforate opening, and higher number of splitters increases especially at higher frequencies.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.710-714
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• 2002

Whenever a noise problem of a product is concerned, a first step is to identify the energy transmission path whether it is an air-borne or a structure-borne. Depending on the characteristic of the noise path, tools on the noise reduction are different. In this paper. an important aspect of the “mass law” in a noise transmission has been investigated. Since an air-borne has 20 dB/Decade, and a structure-borne 10 dB/Decade of a sound transmission loss due to a mass, an engineer who aims to have a light product design should have an enough knowledge on the mass law, especially, the sensitivity of the weight itself. A honeycomb plate is examined as a sample of a light structure to implement a mass law.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.874-878
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• 2003

Acoustic materials are used for the purpose of absorbing noise and reducing transmission of sound into the receiving room. The purpose of this research is to predict the performance of absorbent materials with respect to absorbing behavior and transmission loss as possible as accurately. The performance of the absorbent materials are carried out systematically as follows: The Biot parameter are measured, first. Then using above parameters as input, LMS's SYSNOISE and VIOLINS programs are used to predict absorption coefficient and transmission loss values, which magnitudes are compared with experimental results. As an sample acoustic material, SK SKY VIVA and PET are selected.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.5C
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• pp.305-312
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• 2005

Three classification algorithms are tested using musical instruments. Several classification algorithms are introduced and among them, Bayes rule, NN and k-NN performances evaluated. ZCR, mean, variance and average peak level feature vectors are extracted from instruments sample file and used as data set to classification system. Used musical instruments are Violin, baroque violin and baroque cello. Results of experiment show that the performance of NN algorithm excels other algorithms in musical instruments classification.