• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.658-661
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• 2005

In many fire emergencies, the auditory fire alarm signals are very important to save the occupant's life. But as the sound insulation of building elements has been improved, it is more difficult for occupant to recognize the fire alarm signals when the audible fire alarm worked. This is the first study to show the sound attenuation of audible fire alarm device in apartments. We measured and analyzed the sound attenuation level in seven units. The result showed that it was not sufficient to detect the sound from the fire alarm device in bedrooms. Whether the fire alarm device worked or not, the differences of sound level in bedrooms were below 1$\sim$10dBA. To give the minimum sound level 60dBA in bedrooms, the proper sound levels from alarm device installed in livingrooms were suggested using computer simulation.

• ETRI Journal
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• 제35권1호
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• pp.80-88
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• 2013

A passive infrared or pyroelectric infrared (PIR) sensor is mainly used to sense the existence of moving objects in an indoor environment. However, in an outdoor environment, there are often outbreaks of false alarms from environmental changes and other sources. Therefore, it is difficult to provide reliable detection outdoors. In this paper, two algorithms are proposed to reduce false alarms and provide trustworthy quality to surveillance systems. We gather PIR signals outdoors, analyze the collected data, and extract the target features defined as window energy and alarm duration. Using these features, we model target and false alarms, from which we propose two target decision algorithms: window energy detection and alarm duration detection. Simulation results using real PIR signals show the performance of the proposed algorithms.

• 한국소음진동공학회논문집
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• 제16권6호
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• pp.593-601
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• 2006

In many fire emergencies, the auditory fire alarm signals are very important to save the occupant's life. But as the sound insulation of building elements has been improved, it is more difficult for occupant to recognize the fire alarm signals when the audible fire alarm worked. This is the first study to show the sound attenuation of audible fire alarm device in apartments. We measured and analyzed the sound attenuation level in seven units. The result showed that it was not sufficient to detect the sound from the fire alarm device in bedrooms. Whether the fire alarm device worked or not, the differences of sound level in bedrooms were below 1$\sim$10 dBA. To give the minimum sound level 60 dBA in bedrooms, the proper sound levels from alarm device installed in livingrooms were suggested using computer simulation.

• 한국정보처리학회논문지
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• 제7권9호
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• pp.2958-2968
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• 2000

WDM 시스템에서 효과적으로 감시제어 기능을 수행하기 위해서는 경보신호의 적용이 요구된다. 그러나 광전달망의 각 계층별 적용되어야 할 경보신호에 대한 연구는 현재까지 아직 기초적인 상태에 머물러 있고, 그리고 감시채널의 구조와 구성에 대해서 제안된 연구결과가 없다. 따라서 본 논문은 ITU-T 광전달망의 요구사항을 기초로 하고, 자국과 대구 및 텐덤 구간의 신호 감시기법을 적용하여 단국형과 ADM형 WDM 시스템 모두에 적용할 수 있는 각 계층별 경보신호와 이의 전파 체계를 제시하였고, 감시채널의 구성 및 오버헤드 구조를 보였다. 또한 단국형과 ADM 형의 WDM 시스템에서 다양하게 발생할 수 있는 장애상태에서도 감시제어 기능을 효과적으로 수행할 수 있음을 보였다.

• 한국음향학회지
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• 제40권2호
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• pp.99-108
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• 2021

본 논문에서는 수괴가 능동소나에서 허위표적으로 오인 탐지 될 수 있는지에 대한 여부를 시각적으로 확인하기 위해 시간영역에 대한 음파 전달 수치 실험을 수행하였다. 수치 실험을 위해 무한영역에 과장된 수괴를 표적으로 구성하였으며 불연속 경계에 대해 개발된 시간영역 유사스펙트럴 모델을 이용하여 산란신호를 계산하고 해석해와 비교하였다. 또한, 시간에 따른 음파전달양상을 모의하였다. 이를 통해 수괴 자체가 허위표적으로 탐지 될 수 없음을 확인하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.1162-1168
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• 2007

In many fire emergencies, the audible fire alarm signals are very important to save the occupant's life. But as the sound insulation of building elements has been improved, it is more difficult for occupant to recognize the fire alarm signals when the fire alarm worked. This is the study to show the sound attenuation of the fire alarm sounder system in apartment buildings. We measured and analyzed the sound attenuation level in 17 units, and the results were compared with the minimum sound level at sleeping area by NFPA(National Fire Protection Association) 72. When only the fire alarm worked in stair hall, the sound levels in bedroom were in the range of $30.6{\sim}42.8dB(A)$ and the differences between sound level and ambient sound level in bedrooms were in the range of $7.1{\sim}13.8dB(A)$. And when the emergency broadcasting device in the livingroom and the fire alarm worked simultaneously, the sound levels in bedrooms were in the range of $54.2{\sim}63.0dBA$. Finally, it was showed that the fire alarm sounder system didn't give a sufficient sound level in bedroom to awake out of sleep.

• 한국안전학회지
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• 제37권5호
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• pp.14-21
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• 2022

The purpose of this study was to apply the signal pattern recognition technique to the digital wireless fire-alarm system and to reduce unwanted fire alarms. In this study, the fire alarms of the K Institute, which operates the largest digital wireless fire-alarm system in Korea, were classified into normal operations and unwanted fire alarms, and these were analyzed and compared with actual fire signals. In addition, by designing a non-fire signal filter and applying it to the K Institute, we confirmed that the monthly unwanted fire alarm rate of all 5,713 detectors decreased sharply. In particular, the unwanted fire alarm rate for flame decreased from 1.09% to 0.11% and the unwanted fire alarm rate for smoke decreased from 0.65% to 0.035%.

• 한국안전학회지
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• 제24권3호
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• pp.13-18
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• 2009

This paper is purposed to develop DAQ H/W, S/W and DB which can be used in developing electrical fire alarm system or in analyzing electrical fire cause, by detecting and monitoring precursor signals which have high possibility leading to electrical fire on electrical distribution wires. In this paper, developed was DAQ H/W adopting the C8051FXXX CPU which can analyze the measurement signals of current and voltage in electrical distribution wires, other CPU was investigated in view of the best digital sampling rate on the basis of previous researches for electrical fire alarm system. Also, the S/W which can interface with DAQ H/W's communication protocol and can be applied for electrical fire causes analysis, are embodied by LabVIEW. The combined DAQ H/W and S/W could analyze efficiently normal as well as abnormal electrical signals such as RMS value, instantaneous value of current and voltage, frequency signals etc, on the electrical wires. Also, DB system was constructed for recording various analysis results for precursor signals including voltage and current signals. The results by simulator and experiment showed that the suggested scheme with DAQ H/W, S/W and DB in this paper has high usability.

• 한국안전학회지
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• 제37권3호
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• pp.16-23
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• 2022

This study aims to provide a fundamental material for identifying fire and no-fire signals using the detection signal characteristics of IoT-based fire-detection systems. Unlike analog automatic fire-detection equipment, IoT-based fire-detection systems employ wireless digital communication and are connected to a server. If a detection signal exceeds a threshold value, the measured values are saved to a server within seconds. This study was conducted with the detection data saved from seven fire accidents that took place in traditional markets from 2020 to 2021, in addition to 233 fire alarm data that have been saved in the K institute from 2016 to 2020. The saved values demonstrated variable and continuous VC-Signals. Additionally, we discovered that the detection signals of two fire accidents in the K institution had a VC-Signal. In the 233 fire alarms that took place over the span of 5 years, 31% of smoke alarms and 30% of temperature alarms demonstrated a VC-Signal. Therefore, if we selectively recognize VC-Signals as fire signals, we can reduce about 70% of false alarms.

• 한국군사과학기술학회지
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• 제14권1호
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• pp.100-105
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• 2011

Generally, because received signals from radar are very bulky, the data are divided into manageable size called section, and sections are distributed into several digital signal processors. And then, target detection algorithms are applied simultaneously in each processor. CFAR(Constant False Alarm Rate) algorithm, which is the most popular target detection algorithm, can estimate accurate threshold values to determine which signals are targets or noises within center-cut of section allocated to each processor. However, its estimation precision is diminished in section edge data because of insufficient surrounding data to be referred. Especially this edge problem of CFAR is too serious if we have many sections to be processed, because it causes many false alarms in most every section edges. This paper describes false alarm issues on MCA(Minimum Cell Average)-CFAR, and proposes a false alarm elimination method by changing section size alternatively. Real received data from multi-function radar were used to evaluate a proposed method, and we show that our method drastically decreases false alarms without missing real targets, and improves detection performance.