• 센서학회지
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• 제29권5호
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• pp.360-364
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• 2020

In this study, the colorimetric sensor, polyester (PET) fabric dyed with lead (II) acetate (Pb(C₂H₃O₂)₂), was fabricated and characterized for the detection of the hydrogen sulfide (H₂S). The surface morphology of the fabric was determined using scanning electron microscope and energy-dispersive X-ray spectroscopy. The optical properties of the fabric were evaluated by measuring the variation in the blue value of an RGB sensor. The fabric showed a significant color change, high linearity (R² : 0.98256), and fast response time (< 1.0 s) when exposed to H₂S. This is because the sensor is highly porous and permeable to the gas. The fabric can not only be used as a hydrogen sulfide sensor but also be used to detect and prevent H₂S influx using sticky tape on pipelines.

• 한국미생물·생명공학회지
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• 제47권4호
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• pp.645-650
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• 2019

Despite differences in virulence between strains of Toxoplasma gondii, rapid and accurate genotyping methods are lacking. In this study, a method was developed to detect and genotype T. gondii in food and environmental samples using PCR and a novel peptide nucleic acid (PNA) melting array. An alignment of genome sequences for T. gondii type I, II, and III obtained from NCBI was generated, and a single nucleotide polymorphism analysis was performed to identify targets for PCR amplification and a PNA melting array. Prior to the PNA melting array, conventional PCR was used to amplify GRA6 of T. gondii. After amplification, the PNA melting array was performed using two different PNA hybridization probes with fluorescent labels (FAM and HEX) and quenchers. Melting curves for each probe were used to determine genotypes and identify mutations. A 214-bp region of the GRA6 gene of T. gondii was successfully amplified by PCR. For all T. gondii strains (type I, II, and III) used to evaluate specificity, the correct genotypes were determined by the PNA melting array. Non-T. gondii strains, including 14 foodborne pathogens and 3 protozoan parasites, such as Giardia lamblia, Cryptosporidium parvum, and Entamoeba histolytica, showed no signal, suggesting that the assay has a high specificity. Although this is only a proof-of-concept study, the assay is promising for the fast and reliable genotyping of T. gondii from food and environmental samples.

• 한국압력기기공학회 논문집
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• 제10권1호
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• pp.90-95
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• 2014

Local wall thinning is a point of concern in almost all steel structures such as pipe lines covered with a thermal insulator made up of materials with low thermal conductivity(fiberglass or mineral wool); hence, Non Destructive Technique(NDT) methods that are capable of detecting the wall thinning and defects without removing the insulation are necessary. In this study we developed a Pulsed Eddy Current(PEC) system to detect the wall thinning of Ferro magnetic steel pipes covered with fiber glass thermal insulator and shielded with Aluminum plate. The developed system is capable of detecting the wall thickness change through an insulation of thickness 10cm and 0.4mm aluminum shielding. In order to confirm the thickness change due to wall thinning, two different sensors, a hall sensor and coil sensor were used as a detecting element. In both cases, the results show a very good change corresponding to the thickness change of the test specimen. During these experiments a carbon steel tube of diameter 210mm and a length of 620mm, which is covered with insulator of 95mm thickness was used. To simulate the wall thinning, the thickness of the tube is changed for a specified length such as 2.5mm, 5mm and 8 mm from the inner surface of the tube. A 0.4mm thick Aluminum plate was covered on the Test specimen to simulate the shielding of the insulated pipelines. For both hall sensor and coil detection methods Fast Fourier transform(FFT) was calculated using window approach and the results for the test specimen without Aluminum shielding were summarized which shows a clear identification of thickness change in the test specimen by comparing the magnitude spectra. The PEC system can detect the wall thinning under the 95 mm thickness insulation and 0.4 mm Al shielding, and the output signal showed linear relation with tube wall thickness.

• 조명전기설비학회논문지
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• 제20권2호
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• pp.50-59
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• 2006

제안된 소방설비는 기존 P형과 R형 시스템에 비해 결선량이 P형 대비 74[%]로 획기적으로 줄고, 비 숙련자도 결선이 쉬워 공기와 인건비를 줄일 수 있고, 수신기나 중계기 등의 부가적인 장치가 없어도 안정적으로 동작될 수 있음을 실험을 통해 확인하였다. 소방효과는 R형과 동일하나 물의 사용 양이나 화재 추적 등에 탁월한 기능이 있으며, 사람의 개입 없이 대피유도나 화재진압 정도를 스스로 조절함으로써 얻을 수 있는 무형적 이익과 공사비 절감 및 공기단축 등 유형적 이익을 통해 제안된 시스템이 아주 효과적임을 판단할 수 있었다. 특히 화재진행 상황에 따라 대응정도를 다르게 수행하므로 현재와 같은 유비쿼터스 환경에서 인간의 개입을 최소화하며, 효율을 극대화함으로써 차세대 소방 시스템으로서의 기능을 충분히 갖춘 시스템으로 발전이 가능하다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권4호
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• pp.1457-1470
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• 2015

In wireless multimedia sensor networks (WMSN), the latency of transmission is an increasingly problem. With the improvement of resolution, the time cost in image and video compression is more and more, which seriously affects the real-time of WMSN. In JPEG system, the core of the system is DCT, but DCT-JPEG is not the best choice. Block-based DCT transform coding has serious blocking artifacts when the image is highly compressed at low bit rates. APBT is used in this paper to solve that problem, but APBT does not have a fast algorithm. In this paper, we analyze the structure in JPEG and propose a parallel framework to speed up the algorithm of JPEG on GPU. And we use all phase biorthogonal transform (APBT) to replace the discrete cosine transform (DCT) for the better performance of reconstructed image. Therefore, parallel APBT-JPEG is proposed to solve the real-time of WMSN and the blocking artifacts in DCT-JPEG in this paper. We use the CUDA toolkit based on GPU which is released by NVIDIA to design the parallel algorithm of APBT-JPEG. Experimental results show that the maximum speedup ratio of parallel algorithm of APBT-JPEG can reach more than 100 times with a very low version GPU, compared with conventional serial APBT-JPEG. And the reconstructed image using the proposed algorithm has better performance than the DCT-JPEG in terms of objective quality and subjective effect. The proposed parallel algorithm based on GPU of APBT also can be used in image compression, video compression, the edge detection and some other fields of image processing.

• Structural Engineering and Mechanics
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• 제75권4호
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• pp.477-485
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• 2020

Finite element (FE) model based structural damage detection (SDD) methods play vital roles in effectively locating and quantifying structural damages. Among these methods, structural model updating should be conducted before SDD to obtain benchmark models of real structures. However, the characteristics of updating parameters are not reasonably considered in existing studies. Inspired by the l_∞ norm regularization, a novel anti-sparse representation method is proposed for structural model updating in this study. Based on sensitivity analysis, both frequencies and mode shapes are used to define an objective function at first. Then, by adding l_∞ norm penalty, an optimization problem is established for structural model updating. As a result, the optimization problem can be solved by the fast iterative shrinkage thresholding algorithm (FISTA). Moreover, comparative studies with classical regularization strategy, i.e. the l₂ norm regularization method, are conducted as well. To intuitively illustrate the effectiveness of the proposed method, a 2-DOF spring-mass model is taken as an example in numerical simulations. The updating results show that the proposed method has a good robustness to measurement noises. Finally, to further verify the applicability of the proposed method, a six-storey aluminum alloy frame is designed and fabricated in laboratory. The added mass on each storey is taken as updating parameter. The updating results provide a good agreement with the true values, which indicates that the proposed method can effectively update the model parameters with a high accuracy.

• 한국산학기술학회논문지
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• 제13권12호
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• pp.6208-6214
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• 2012

해양미세조류 유래 독성물질에 대한 이해와 활용에 있어서 가장 중요하지만 간과되고 있는 부분은 독성물질을 검출할 수 있는 빠르고, 쉽고 경제적인 검출기술을 개발하는 것이다. 이 논문에서 우리는 삭시톡신(STX)에 대한 항체를 생산하였다. 헤모시아닌(mariculture keyhole limpet hemocyanin, mcKLH)과 오브알부민(ovalbumin, OVA)을 운반단백질로 사용하였다. 면역반응을 위해서 mcKLH-STX 결합체를 BALB/c 쥐에 복강주사하였다. 채혈 후 항-STX 항혈청을 분리하였다. 항혈청의 역가분석을 위하여 유리 STX와 OVA-STX로 코팅된 microtiter plate를 이용하여 간접 ELISA 실시하였다. 발색반응을 위한 이차항체로는 goat anti-mouse IgG-phosphatase conjugate가 사용되었다. 항-STX 항혈청은 OVA-STX와 유리 STX에 특이적으로 반응하였다. 항-STX 항혈청의 민감도는 매우 높았으며, STX를 위한 검출한계는 약 64.9 ng/kg이었다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권6호
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• pp.2935-2937
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• 2014

Studies of the causes of cancer, early detection, prevention or treatment need accurate, comprehensive, and timely cancer data. The clinical laboratory provides important cancer information needed for physicians which influence clinical decisions regarding treatment, diagnosis and patient monitoring. Poor communication between health care providers and clinical laboratory personnel can lead to medical errors and wrong decisions in providing cancer care. Because of the key impact of laboratory information on cancer diagnosis and treatment the quality of the tests, lab reports, and appropriate lab management are very important. A laboratory information management system (LIMS) can have an important role in diagnosis, fast and effective access to cancer data, decrease redundancy and costs, and facilitate the integration and collection of data from different types of instruments and systems. In spite of significant advantages LIMS is limited by factors such as problems in adaption to new instruments that may change existing work processes. Applications of intelligent software simultaneously with existing information systems, in addition to remove these restrictions, have important benefits including adding additional non-laboratory-generated information to the reports, facilitating decision making, and improving quality and productivity of cancer care services. Laboratory systems must have flexibility to change and have the capability to develop and benefit from intelligent devices. Intelligent laboratory information management systems need to benefit from informatics tools and latest technologies like open sources. The aim of this commentary is to survey application, opportunities and necessity of intelligent clinical laboratory as a tool to increase cancer care management productivity.

• 한국정보과학회논문지:정보통신
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• 제37권2호
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• pp.122-134
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• 2010

자동차 관련 응용 프로그램에 대한 요구가 빠르게 증가되면서, 자동차 무선 네트워크에서 연속적이고 견고한 멀티미디어 서비스를 위한 필요성이 대두되고 있다. 이동성이 있는 환경에서 연속적인 서비스를 제공해주기 위해, 기본적인 이동성 프로토콜인 MIPv6은 물론 MIPv6의 문제점을 해결하기 위한 FMIPv6와 같은 프로토콜들이 개발되었다. 하지만, MIPv6, FMIPv6는 긴 핸드오버 지연시간과 패킷 손실 문제로 인해 멀티미디어와 같이 품질 보증이 필요한 서비스에는 사용할 수 없다. 따라서 본 논문은 자동차 무선 네트워크 환경에서 자동차가 처음 속해있던 액세스 라우터에서 만든 원래 임시 주소(oCoA : original CoA)와 뒷단 주소 중복성 검사(background DAD : Duplicate Address Detection)를 이용하여 연속적이고 견고한 멀티미디어 서비스를 제공해줄 수 있는 이동성 프로토콜을 제안한다. 성능평가를 통해 제안한 방식이 자동차 무선 네트워크 환경에서 제일 적합함을 증명한다.

• 전력전자학회논문지
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• 제9권6호
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• pp.568-576
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• 2004

본 논문은 신$.$재생에너지를 이용한 분산전원시스템을 위한 새로운 단독운전 방지기법을 제시한다. 유효전력과 무효전력 불균형의 개념에 근거해서 3가지 다른 단독운전 조건이 분석된다. 단독운전 전압이 유효전력의 함수이고 그 주파수는 유효전력과 무효전력의 함수임이 분석을 통해 보여준다. 이 분석결과를 이용해서 새로운 단독운전 방지기법이 개발되었다. 제안된 보호 알고리즘은 분산전원에 의해 공급되는 무효전력을 계속적으로 $\pm$5% 변화시키면서 동시에 계통전압과 주파수를 관측한다. 만일 단독운전에 의해 측정할 정도의 주파수 이탈이 발생하면 더 나아가 분산전원의 유효전력을 80%로 감소시킨다. 이 검출기법은 공진부하에서도 빠르게 동작됨을 보여준다. 가능한 단독 운전조건이 모의되고 분석 증명된다. 0.5 kW 연계형 연료전지 시스템의 실험결과가 제시된다.