• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.04a
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• pp.75-76
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• 2013

화재가 발생하면 소방과 경찰기관 등에서 화재원인과 관련된 조사를 하여 조사보고서를 작성하고 있고, 화재와 관련된 법적분쟁 등이 발생한 경우에 이 조사보고서는 법적분쟁을 해결하는데 중요한 역할을 하고 있다. 법적분쟁에서 가장 핵심적인 부분은 발화개소와 발화원인(화재원인)인 경우가 많으므로 조사보고서의 발화개소와 발화원인 판정에 오류가 있어서는 안 된다. 발화개소와 발화원인 판정에 오류가 있는 경우 불필요한 분쟁초래 등 심각한 문제가 발생하고 있다. 이 논문에서는 화재조사관련 전문지식 부족으로 인해 화재원인판정에 오류가 있었던 사례에 대해 구체적으로 분석하고, 유사 오류를 예방하기 위한 유의사항을 제시한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.414-417
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• 2019

스마트 스피커는 기존 서비스와 달리 음성으로 데이터를 수집할 뿐 아니라 수집한 데이터를 기반으로 처리한 정보를 스피커를 통해 발화하는, 즉 소리로 전달하는 특징을 가진다. 이러한 서비스 응답 구조는 스피커에서 음성을 통해 전달되는 정보에 사용자의 개인정보가 포함되어 발화될 수 있는 위험이 존재한다. 구글, 아마존의 스마트 스피커 초기 설정 시 동의 과정 분석을 통해 개인정보 발화 위험을 사용자가 명확히 인지하기 어렵다는 문제를 발견하였다. 이에 본 연구는 스마트 스피커 서비스의 사용자 동의 과정에서 사용자의 개인정보 발화 위험 인식 재고를 위한 UI/UX 개선방안으로 1) 개인정보 발화 위험성 약관 명시 및 별도 화면 제시, 2) 사용자의 자유로운 서비스 동의 허용, 3) 컨트롤러에게 전달되는 개인정보와 스피커를 통해 발화될 수 있는 개인정보를 구분하여 제시, 4) 개인정보 발화 위험에 대한 음성 고지 및 동의 과정 추가를 제안하였다.

• Phonetics and Speech Sciences
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• v.11 no.2
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• pp.33-44
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• 2019

This paper dealt with how realization of pauses in utterance is affected by speech style, gender, and generation. For this purpose, we analyzed the frequency and duration of pauses. Pauses were categorized into four types: pause with breath, pause with no breath, utterance medial pause, and utterance final pause. Forty-eight subjects living in Seoul were chosen from the Korean Standard Speech Database. All subjects engaged in reading and spontaneous speech, through which we could also compare the realization between the two speech styles. The results showed that utterance final pauses had longer durations than utterance medial pauses. It means that utterance final pause has a function that signals the end of an utterance to the audience. For difference between tasks, spontaneous speech had longer and more frequent pauses because of cognitive reasons. With regard to gender variables, women produced shorter and less frequent pauses. For male speakers, the duration of pauses with breath was significantly longer. Finally, for generation variable, older speakers produced more frequent pauses. In addition, the results showed several interaction effects. Male speakers produced longer pauses, but this gender effect was more prominent at the utterance final position.

• The Journal of the Acoustical Society of Korea
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• v.23 no.2
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• pp.162-172
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• 2004

This study investigates the following three things through a production experiment and acoustic analysis: 1) relationship between speech rate and the segment duration in Korean, 2) relationship between speech rate and spectral characteristics of vowels, i. e. undershoot, and 3) correlation between the vowel duration and undershoot. The results showed that the faster the speech rate nab, the shorter the duration of syllables and segments was. A few speakers were affected by speech rate in the durational ratios between closure and aspiration in a stop and between Towel and consonant in a syllable. Closure duration and vowel duration were more affected compared to aspiration and consonant duration, respectively. Speakers showed some differences in the extent to which speech rate affected vowel undershoot, implying that speakers used different production mechanisms for spectral characteristics of vowels: Some speakers speeded up movement of articulatory organs according to speech rate increase while some kept it constant regardless of speech rate change.

• The Journal of the Korea Contents Association
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• v.13 no.9
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• pp.495-503
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• 2013

The purpose of this study was to investigate how Korean speakers produce English vowels. Twenty one Korean learners produced the vowels [i, ɪ, eɪ, ɛ, æ, ɑ, ʌ, ɔ, oʊ, ʊ, u] in bVt or pVt forms of real words. Acoustic measurements were conducted for the vowel formant frequencies (F1, F2) and duration. Results showed that Korean learners tended to produce the vowel duration longer than native English speakers. Also, the front vowels produced by Korean participants tended to be produced at the more frontal part of the tongue. In addition, Korean participants distinguished the tense and lax pairs not through quality(F1, F2) but through vowel duration. This is different from the native English speakers in that they differentiate tense and lax pairs by quality(F1, F2) as well as vowel duration. Based on these results, pedagogical implications are discussed.

• Journal of Energy Engineering
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• v.25 no.1
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• pp.48-55
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• 2016

The autoignition temperature (AIT) of a material is the lowest temperature at which the material will spontaneously ignite. The AIT is important index for the safe handling of flammable liquids which constitute the solvent mixtures. This study measured the AITs of n-hexanol+p-xylene system by using ASTM E659 apparatus. The AITs of n-hexanol and p-xylene system which constituted binary system were $275^{\circ}C$ and $557^{\circ}C$, respectively. The experimental AITs of n-hexanol+p-xylene system system were a good agreement with the calculated AITs by the proposed equations with a few A.A.D.(average absolute deviation).

• Journal of the Korea society of information convergence
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• v.7 no.2
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• pp.59-65
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• 2014

Grassfire spot matching method is based on similarity comparison of topological patterns for neighbor spots. This is a method where spot matching is performed as if fire spreads all around on grass. Spot matching starts from a seed spot pair confirmed as a matched pair of spots and spot matching spreads to the direction where the best matching result is produced. In this paper, it is a bit complicated way of grassfire method where multi-seed matched spot pair are manually selected and spot matching is performed from each multi-seed matched spot pair. The proposed method shows better performance in detection rate and accuracy than that of the previous method.

• Journal of the Korean Applied Science and Technology
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• v.39 no.2
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• pp.368-376
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• 2022

Spontaneous ignition occurs in industrial sites or anywhere in our lives, and is a phenomenon in which a substance ignites itself without an ignition source in the atmosphere. As the rate of chemical reaction increases, the heat generated increases, and the risk of spontaneous ignition increases. In this study, safe raw materials used for food and cosmetics were mixed to prepare coal spontaneous ignition prevention agents specifically among various spontaneous ignition phenomena. The effect of suppressing spontaneous combustion of coal was confirmed through lab and field tests with low-calorie, low-grade coal from Indonesia. As a result of the outdoor field test, the ignition prevention agent manufactured in this study compared with the control group(Fire after 90 days) showed excellent ignition inhibitors for more than 120 days. In addition, CO concentration control was confirmed by comparing the concentration of carbon monoxide for 50 days at the indoor coal yard. It was confirmed that the results were better than the comparative group coal and the existing anti-firing method. In addition, the possibility of coal fire prevention agents for indoor coal farms will be applied from 2024 was confirmed by studying the environment and safety of workers' working environments through official test such as soil and water quality test, MSDS of coal fire prevention agents in consideration of working workers, water quality, and eye irritation tests.

• Fire Science and Engineering
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• v.33 no.2
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• pp.20-29
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• 2019

In this paper, the effect of spontaneous combustion inhibitor on the surface of coal stockpile in coal yard was investigated by numerical analysis. First, the numerical analysis method of the present study was compared with the results of the previous study by analyzing the case where the spontaneous combustion inhibitor was not applied, and the effect of preventing spontaneous combustion by various areas and positions for spraying spontaneous combustion inhibitor was analyzed. As a result, the larger the application area of the spontaneous combustion inhibitor, the more the effect of preventing spontaneous combustion by blocking the oxygen inflow into the coal stockpile, and the greater the effect of the spontaneous combustion prevention when spraying spontaneous combustion inhibitor from the bottom of the coal stockpile. Spontaneous combustion inhibitor should be sprayed effectively, considering the economic aspects, such as manufacturing cost etc.

• Fire Science and Engineering
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• v.33 no.1
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• pp.7-14
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• 2019

While wood pellets are often used as a fuel in thermoelectric power plants and firewood boilers, there is a risk of ignition temperature when strong wood pellets, which have a high calorific value, for prolonged periods of time. In this research study, the minimum auto ignition temperature and the ignition limitation temperature according to the change in flow rate depending on the size of the test vessel were calculated, and based on these temperatures, the apparent activation energy was calculated to predict the combustive properties of the material. The apparent activation energy was calculated to be 190.224 kJ/mol. The thicker the sample is storage in the vessel, the longer the ignition induction time was due to the increased difficulty in heat being transferred from the surface of the vessel to the middle section area of the vessel. For vessel of the same size, the higher the flow rate, the lower the auto ignition temperature was. It was also confirmed that increases in the size of the test vessel lowered the auto ignition temperature and increased the ignition induction time.