• 한국위성정보통신학회논문지
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• 제12권1호
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• pp.101-106
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• 2017

In this paper, we present Emergency exit signs are installed to provide escape routes or ways in buildings like shopping malls, hospitals, industry, and government complex, etc. and various other places for safety purpose to aid people to escape easily during emergency situations. In case of an emergency situation like smoke, fire, bad lightings and crowded stamped condition at emergency situations, it's difficult for people to recognize the emergency exit signs and emergency doors to exit from the emergency building areas. This paper propose an automatic emergency exit sing recognition to find exit direction using a smart device. The proposed approach aims to develop an computer vision based smart phone application to detect emergency exit signs using the smart device camera and guide the direction to escape in the visible and audible output format. In this research, a CAMShift object tracking approach is used to detect the emergency exit sign and the direction information extracted using template matching method. The direction information of the exit sign is stored in a text format and then using text-to-speech the text synthesized to audible acoustic signal. The synthesized acoustic signal render on smart device speaker as an escape guide information to the user. This research result is analyzed and concluded from the views of visual elements selecting, EXIT appearance design and EXIT's placement in the building, which is very valuable and can be commonly referred in wayfinder system.

• Ocean and Polar Research
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• 제27권3호
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• pp.335-339
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• 2005

The underwater positioning system is important in interpreting data that are acquired from towing vehicles such as the deep-sea camera (DSC) system. Currently, several acoustic positioning systems such as long baseline (LBL), short baseline (SBL), and ultra short baseline (USBL), are used for underwater positioning. The accurate position of DSC, however, could not be determined in a R/V Onnuri unequipped with any of these underwater positioning systems. As an alternative, the DSC position was estimated based on the topography of towing track and cable length in the cruises before 1999. The great uncertainties, however, were found in the areas of flat bottom topography. In the 2003 and 2004 cruises these uncertainties were reduced by calculating the position of DSC with the cable length and seafloor depth below the vessel. The Japanese cruises for Mn-nodule used a similar estimation method for the DSC positioning system with a CTD sensor. Although the latter can provide better information for the position of DSC, the USBL underwater positioning system is strongly recommended for establishing better positioning of DSC and other towing devices.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2003년도 춘계학술대회 논문집
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• pp.89-93
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• 2003

The Korea Research Institute of Ships and Ocean Engineering (KRISO), the ocean engineering branch of KORDI, has designed and manufactured a model of an autonomous underwater vehicle (AUV) to test underwater docking. This paper introduces the AUV model, ASUM, equipped with a visual servo control system to dock into an underwater station with a camera and motion sensors. To make a visual servoing AUV, this paper implemented the visual servo control system designed with an augmented state equation, which was composed of the optical flow model of a camera and the equation of the AUV's motion. The system design and the hardware configuration of ASUM are presented in this paper. A small long baseline acoustic positioning system was developed to monitor and record the AUV's position for the experiment in the Ocean Engineering Basin of KRISO, KORDI. ASUM recognizes the target position by processing the captured image for the lights, which are installed around the end of the cone-type entrance of the duct. Unfortunately, experiments are not yet conducted when we write this article. The authors will present the results for the docking test of the AUV in near future.

• 한국음향학회지
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• 제39권3호
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• pp.151-162
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• 2020

본 논문에서는 음향 역산법을 이용한 기포의 크기 분포 추정 기법을 제시하였다. 제 1종 Fredholm 적분방정식으로 표현된 감쇠계수의 추정오차를 목적함수로 정의하였고, 최적해를 구하기 위해 Levenberg-Marquardt(LM)기법을 적용하였다. 두 가지의 기포 분포에 대한 수치 시뮬레이션을 통해 제안된 역산 기법의 유용성을 검증하였다. 세 종류의 기포발생기를 이용하여 사각 수조(1.0 m × 0.54 m × 0.6 m)에서 기포 실험을 수행하였다. 고속카메라 촬영을 통해 기포의 분포 이미지를 획득하였고, 음원과 수중청음기를 이용하여 기포층의 주파수별 삽입손실(insertion loss)을 계측하였다. 촬영된 이미지는 후처리를 통해 기포 발생기별 기포 분포 특성을 파악하는데 활용하였고, 계측된 삽입손실에 역산 기법을 적용하여 기포의 크기 분포를 추정하였다. 음향 역산결과로부터 기포의 크기가 작아짐에 따라 기포 개수는 지수적으로 증가하며, 70 ㎛ ~ 120 ㎛의 국부 피크를 지난 후 다시 증가하는 경향성을 확인하였다.

• 지구물리와물리탐사
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• 제26권1호
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• pp.8-17
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• 2023

해양 환경에서의 기포는 바람, 파도, 선박 및 해저 가스 누출을 포함한 여러 요인에 의해 생성된다. 수중에서의 기포는 강력한 산란 신호를 생성하여 음향 신호를 측정하는데 영향을 미친다. 이러한 기포의 특성은 음파 신호의 세기를 감쇠시켜 소음 차단 목적으로 주로 이용되고 있으며, 최근에는 해저에서 대규모로 누출되는 메탄가스 탐지를 위한 연구가 진행되고 있다. 이러한 가스 누출은 기포플룸의 형태를 취하며, 기포의 물리적 특성과 분포 구조를 이해하는 것은 누출된 가스를 기후 변화와 연관성을 파악하는데 중요한 요소 중 하나이다. 본 연구에서는 탄성파 영상화 기법을 이용하여 기포플룸의 분포를 추정하고자 수조환경에서 실험을 수행하였으며, 별도로 제작된 인공기포 발생기, 자료 취득 시스템을 이용하여 기포에 의한 음향 신호를 취득하였다. 기포플룸을 영상화하기 위해 지진파 영상기법 중 역시간 구조보정을 이용하였으며, 획득한 음향 신호의 포락선 신호를 이용하여 기포 분포 패턴을 효과적으로 추정하였다. 영상화 결과의 검증을 위해 추정된 기포플룸의 분포와 광학카메라 영상을 비교하였다. 실험결과 탄성파 영상화 기법 통해 인공 기포플룸의 산란신호를 이용한 영상화가 가능함을 확인하였다.

• 한국음향학회지
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• 제42권3호
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• pp.243-249
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• 2023

함정 추진기에서 발생하는 캐비테이션은 함의 생존성과 직결되어 있으며, 생존성 향상을 위해 추진기 캐비테이션 초생이 지연되는 추진기 형상을 요구하고 있다. 그러나 한번 함정이 건조되고 나면 다양한 운용 조건에서 캐비테이션이 발생할 수 있어, 설계 뿐만 아니라 운용 시에도 추진기 캐비테이션 발생 여부를 알 수 있어야 한다. 이를 위해 선내에서 계측한 신호를 이용한 캐비테이션 발생 여부 판단이 필요하다. 본 연구에서는 추진기 상방 선체에 하이드로폰과 가속도계를 설치하여 추진기에서 발생하는 음향/진동 신호의 상관관계와 각 센서를 이용한 캐비테이션 초생 분석 성능에 대해 비교를 수행하였다. 캐비테이션 발생을 시각적으로 파악하기 위하여 선미부에 관측창을 설치하여 고속카메라 계측을 수행하였다. 계측 결과 음향과 진동 신호 간 스펙트럼 형상은 다르게 나타났으나, 선속에 따른 밴드별 레벨 증가분, 1 kHz ~ 10 kHz 대역의 전체 레벨 등은 비슷한 경향을 나타냈다. Detction of Envelope Modulation On Noise(DEMON) 분석에서도 음향과 진동신호 모두 비슷한 결과를 보여주었으며, 이를 통해 추진기 캐비테이션 발생분석에는 하이드로폰과 가속도계 모두 활용할 수 있음을 확인하였다.

• 대한기계학회논문집A
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• 제24권6호
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• pp.1491-1498
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• 2000

In recent years, CFRP composite materials have been increasingly used in various fields of engineering because of a high specific strength and stiffness properties. Drilling is one of the most impo rtant cutting processes that are generally carried out on CFRP materials owing to the need for the structural integration. However, delamination are often occurred as one of the drilling damages. Therefore, there are needs studying for the relationships between CFRP drilling and delamination in order to avoid low strength of the structures and inaccuracies of the integration. In this study, AE signals and thrust forces were used for the evaluations of the delamination from a drilling process in [0/900]s CFRP materials. And the drilling damage processes were observed and measured by a real time monitoring technique with a video camera. From the results, we found that the relationships between the delamination from drilling and AE characteristics and drill thrust forces for [0/900]s CFRP composites. Also, we proposed the monitoring method for a visual analysis of drilling damages.

• 수산해양기술연구
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• 제32권1호
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• pp.50-58
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• 1996

The authors carried out a field experiment to confirm the effect of underwater sound on the luring of fish schools in a setnet in the coast of Cheju Island. The effects of the acoustic emission on the luring of fish schools were observed using a manufectured underwater speaker in the setnet, and pure sound, of which frequency was 600Hz and the source level was 126dB, was emitted on and off at 5 minutes intervals in the set net during the night of ,July 29 and ,July 31. So we had recorded behavior of fish schools by the telesounder with two channel and shape of the setnet by underwater video camera and analyzed them. When the flood and ebb currents were around the setnet, the nets rised to the surface of water and it happened occasionaly at the stand of tide. Therefore, it was in the state that fish schools feel constraint to enter into the setnet, and was required a new design of the setnet stand up to strong tidal current. As the pure sound, of which frequency was 600Hz was emitted for the luring of fish schools in a setnet, the catch ammounts of fish, the young horce mackereWI'rachllrlls japonicus), was increased 4~6 times than not emitted.

• 한방안이비인후피부과학회지
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• 제20권2호통권33호
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• pp.142-150
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• 2007

Objectives : This study was carried out to investigate the latest study tendency in mouse model of skin pruritus published since 2005 and to arrange various experimental methods. Methods : We examined the journal(such as Experimental dermatology and British journal of dermatology) and in Pubmed since 2005, regarded pruritus and scratching behavior model as key words. Results and Conclusion : 1. BALB/c, hairless, NC/Nga and ICR mice were the most used in scratching behavior model. According to scratching-induced agents. we need to select experimental mice. 2. There are various methods inducing skin pruritus; by cohabitation with NC/Nga mice having severe skin lesions, by injection intradermally(or subcutaneously) with agent inducing inflammation, by inducing contact dermatitis with TNCB, TNFB, destruction of skin barrier and by transgenic mice. 3. Injection intradermally(or subcutaneously) with agent inducing inflammation is the most used out of methods inducing skin pruritus. Compound 48/80, histamine, substance P and others(chloroquine, serotonin, carrageenin, TPA etc.) were included in agents inducing inflammation and pruritus in skin pruritus model. 4. Video camera, SCLABA system, MicroAct and acoustic evaluation system were included in evaluation methods of scratching behavior mouse model.

• 한국소음진동공학회논문집
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• 제24권3호
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• pp.253-260
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• 2014

conducted. In-situ measurements were conducted to investigate the noise characteristics in high-speed trains such as KTX and KTX-Sancheon. Binaural microphones and spherical microphone were adopted to record and evaluate the spectral characteristics and noise incidence characteristics at the seats in the passenger cars. Environmental elements were also recorded during the noise measurements using a camcorder and GPS application. In addition, auditory tests were conducted to investigate annoyance of interior noise of high-speed trains. Based on the objective measure and subjective responses on interior noise, statistical analysis such as correlation and regression analyses were carried out. From the results perception models for evaluating the interior noise of high-speed train were derived.