• Steel and Composite Structures
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• 제24권4호
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• pp.391-397
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• 2017

With the increasing application of explosive composite structure in many engineering fields, its interface bonding state detection is more and more significant to avoid catastrophic accidents. However, this task still faces challenges due to the complexity of the bonding interface. In this paper, the concept of nonlinear output frequency response functions (NOFRFs) is introduced to detect the bonding state of explosive composite structure. The NOFRFs can describe the nonlinear characteristics of nonlinear vibrating system. Because of the presence of the bonding interface, explosive composite structure itself is a nonlinear system; when bonding interface of the structure is damaged, its dynamic characteristics show enhanced nonlinear characteristic. Therefore, the NOFRFs-based detection index is proposed as indicator to detect the bonding state of explosive composite pipes. The experimental results verify the effectiveness of the detection approach.

• 공업화학
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• 제30권4호
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• pp.399-407
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• 2019

국내외 테러에 대한 공포와 안보 환경에서 폭발물을 검출 기술 개발은 매우 중요한 문제이다. 특히, 최근 항공보안성능 인증제 실시에 따른 폭발물 탐지 기술의 국산화 기술에 있어서 관련 연구가 요구된다. 폭발물 검출 및 탐지 기술은 전통적인 화학분석법을 통하여 이루어지고 있으나 높은 민감도, 빠른 분석, 소형화, 휴대성 등을 위해서는 전기화학적 방법이 적합하다고 여겨진다. 전기화학적 폭발물 탐지 기술의 대부분은 미국, 중국, 이스라엘 등에서 주로 연구가 되고 있지만 국내에서는 아직 관련 연구가 미비한 실정이다. 본 총설에서는 해외에서 수행되고 있는 전기화학적 폭발물 탐지 기술의 원리와 연구 동향을 보고하고 앞으로 우리가 탐구해야 할 연구 방향을 제시하고자 한다.

• 반도체디스플레이기술학회지
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• 제17권1호
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• pp.54-61
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• 2018

In this study, two aspects were analyzed about the robot for removal of explosive devices. First, the cost analyses were performed to provide a reasonable solution for the acquirement of the system. It is processed by an engineering estimate method and the process was consisted of two ways : a system development expense and a mass production unit price. In additions, the resultant cost analyses were compared between the cases excluding and including a mines detection system. As results, in the case of the acquirement of the robot system for removal of explosive devices, it is recommended that the performance by improving the mines detection ability should be considered preferentially rather than the cost because the material cost for the mines detection system is negligible compared to the whole system cost. Second, as a way for improving the system performance by the mine detection function, the carbon nanotube (CNT) based sensor technology was studied in terms of sensitivity and simple productivity with presenting its preliminary experimental results. The detection electrodes were formed by a photolithography method using a photosensitive CNT paste. As results, this method was shown as a scalable and expandable technology for the excellent mines detection sensors.

• 공업화학
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• 제33권1호
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• pp.1-10
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• 2022

본 논문은 주요 폭발물 탐지 기술에 대한 원리, 장단점 및 향후 필요한 연구 분야에 대한 총설이다. 폭발물 탐지 기술은 분광학적 방법(spectroscopic methods), 감지기 기술(sensor techniques), 후각 감지기(olfactory type sensors)로 분류할 수 있다. 이러한 탐지 기술은 많은 발전이 있었지만 폭발물 탐지를 위한 판별성, 휴대성, 감도에 관한 연구 가능성이 높은 것으로 보인다.

• Steel and Composite Structures
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• 제19권3호
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• pp.569-583
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• 2015

Recent years, explosive welding structures have been widely used in many engineering fields. The bonding state detection of explosive welding structures is significant to prevent unscheduled failures and even catastrophic accidents. However, this task still faces challenges due to the complexity of the bonding interface. In this paper, a new method called dual-tree complex wavelet transform based permutation entropy (DTCWT-PE) is proposed to detect bonding state of such structures. Benefiting from the complex analytical wavelet function, the dual-tree complex wavelet transform (DTCWT) has better shift invariance and reduced spectral aliasing compared with the traditional wavelet transform. All those characters are good for characterizing the vibration response signals. Furthermore, as a statistical measure, permutation entropy (PE) quantifies the complexity of non-stationary signals through phase space reconstruction, and thus it can be used as a viable tool to detect the change of bonding state. In order to more accurate identification and detection of bonding state, PE values derived from DTCWT coefficients are proposed to extract the state information from the vibration response signal of explosive welding structure, and then the extracted PE values serve as input vectors of support vector machine (SVM) to identify the bonding state of the structure. The experiments on bonding state detection of explosive welding pipes are presented to illustrate the feasibility and effectiveness of the proposed method.

• 한국지하수토양환경학회지:지하수토양환경
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• 제14권2호
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• pp.45-53
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• 2009

환경 시료 (토양 및 수질)내 화약물질을 신속하고 간편하게 검출할 수 있다면, 현장조사에서 오염도 조사를 위한 스키리닝 단계로 이용하여 불필요한 시료의 갯수와 고가의 실험실 정량분석비용을 줄일 수 있다. 상용 EXPRAY$^{(R)}$ Explosives Field Detection Kit(EXPRAY)를 이용하여 14종의 화약물질을 대상으로 화약물질 표준용액에 대한 최저검출농도를 결정 하고 및 준정량화 가능성을 확인하기 위한 실험을 실시하였다. 실험결과 EXPRAY는 14종의 화약물질 중에서, TNT, RDX, HMX, Tetryl및 TNB등 5종의 화약물질을 검출할 수 있었다. Nitramine계열인 HMX와 RDX에 대한 최저검출농도는 모두 14ng/mm$^2$이었다 EXPRAY는 nitroaromatic계열에는 더욱 민감하게 반응하여, Tetryl, TNB및 TNT에 대한 단위면적당(mm$^2$)최저 검출량이 각각 3ng, 3ng및 0.3ng이었다. 실험이 통제되는 조건에서 화약물질 표준용액에 EXPRAY를 적용하였을 경우에는 발색 강도의 비교를 통해 10배 단위의 준정량화가 가능하였다. 그러나 오염토양으로 실험한 경우에는 화약물질의 존재여부 및 종류만을 확인할 수 있었다. EXPRAY Explosives Detection Kit$^{(R)}$가 화약물질을 검출할 수 있는 경제적이고 민감한 방법이지만, 현장시료의 스크리닝 단계에만 적용할 수 있는 방법이다.

• Steel and Composite Structures
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• 제31권3호
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• pp.233-242
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• 2019

Early detection of damage bonding state such as insufficient bonding strength and interface partial contact defect for the explosive clad pipe is crucial in order to avoid sudden failure and even catastrophic accidents. A generalized and efficient model of the explosive clad pipe can reveal the relationship between bonding state and vibration characteristics, and provide foundations and priory knowledge for bonding state detection by signal processing technique. In this paper, the slender explosive clad pipe is regarded as two parallel elastic beams continuously joined by an elastic layer, and the elastic layer is capable to describe the non-uniform bonding state. By taking the characteristic beam modal functions as the admissible functions, the Rayleigh-Ritz method is employed to derive the dynamic model which enables one to consider inhomogeneous system and any boundary conditions. Then, the proposed model is validated by both numerical results and experiment. Parametric studies are carried out to investigate the effects of bonding strength and the length of partial contact defect on the natural frequency and forced response of the explosive clad pipe. A potential method for identifying the bonding quality of the explosive clad pipe is also discussed in this paper.

• 융합보안논문지
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• 제18권1호
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• pp.157-166
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• 2018

이 연구는 세계적으로 국가뿐만 아니라 민간인들을 대상으로 폭발물 테러가 빈번히 발생하고 있는 시점에서 다양한 기계장치와 인력을 배치하여 폭발물 탐지를 실시하고 있으나 기계장치의 오류, 인간의 감지능력 한계로 인하여 완벽한 폭발물 테러 예방이 어려운 상황임에 주목하였다. 따라서 이 연구는 폭발물 탐지견 도수사들의 인식을 분석을 토대로 폭발물 탐지견 활용을 통해 다양한 형태의 폭발물 테러로부터 국가중요시설 및 대형민간 시설과 시설 이용자들의 안전을 도모하기 위해 폭발물 탐지견 활용의 필요성을 인식하고 현재 문제점으로 나타나고 있는 상황에 대하여 개선책을 제시하고자 하였다. 도출된 결과는 첫째, 국가중요시설 및 대형 민간시설에 대한 폭발물 탐지견 도입 의무사항을 법률제도로서 입법화하는 것이다. 둘째, 폭발물 탐지견의 탐지능력을 검증하기 위하여 폭발물 탐지견의 인증제도를 도입하는 것이다. 셋째, 폭발물 탐지견을 운용하는 전문 도수사 활성화를 위한 전문 인력 양성제도를 도입하는 것이다.

• Bulletin of the Korean Chemical Society
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• 제34권6호
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• pp.1668-1672
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• 2013

We developed a standoff Raman detection system for explosive molecules (EMs). Our system was composed of reflective telescope with 310 mm diameter lens, 532 nm pulse laser, and Intensified Charge-Coupled Device (ICCD) camera. In order to remove huge background noise coming from ambient light, laser pulses with nanosecond time width were fired to target sample and ICCD was gated to open only during the time when the scattered Raman signal from the sample arrived at ICCD camera. We performed standoff experiments with military EMs by putting the detector at 10, 20 and 30 m away from the source. The standoff results were compared with the confocal Raman results. Based on our standoff experiments, we were able to observe the peaks in the range of 1200 and $1600cm^{-1}$, where vibrational modes of nitro groups were appeared. The wave numbers and shapes of these peaks may serve as good references in detecting and identifying various EMs.

• 한국소음진동공학회논문집
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• 제21권3호
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• pp.280-284
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• 2011

The mass change during the molecular interaction between explosive specific bio-receptors and target molecules has been measured using quartz crystal microbalance(QCM), which has a mass change detection limit up to ~ng/$cm^2$. The environmental effect on the molecular interaction has been evaluated. In the liquid phase molecular interaction experiments, the high selectivity of the bio-receptor to DNT compared with toluene has been shown and the sensitivity for various concentrations of DNT has been demonstrated.