• JSTS:Journal of Semiconductor Technology and Science
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• 제14권6호
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• pp.706-711
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• 2014

A low power 6-bit flash ADC that uses an input voltage range detection algorithm is described. An input voltage level detector circuit has been designed to overcome the disadvantages of the flash ADC which consume most of the dynamic power dissipation due to comparators array. In this work, four digital input voltage range detectors are employed and each input voltage range detector generates the specific clock signal only if the input voltage falls between two adjacent reference voltages applied to the detector. The specific clock signal generated by the detector is applied to turn the corresponding latched comparators on and the rest of the comparators off. This ADC consumes 68.82 mW with a single power supply of 1.2V and achieves 4.3 effective number of bits for input frequency up to 1 MHz at 500 MS/s. Therefore it results in 4.6 pJ/step of Figure of Merit (FoM). The chip is fabricated in 0.13-um CMOS process.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2008년도 춘계학술발표대회
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• pp.935-938
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• 2008

DoS/DDoS 공격과 웜 공격으로 대표되는 트래픽 폭주 공격은 그 특성상 사전 차단이 어렵기 때문에 빠르고 정확한 탐지는 공격 탐지 시스템이 갖추어야 할 필수요건이다. 기존의 SNMP MIB 기반 트래픽 폭주공격 탐지 방법은 1 분 이상의 탐지 시간을 요구하였다. 본 논문은 SNMP MIB 객체의 상관 관계를 이용한 빠른 트래픽 폭주 공격 탐지 알고리즘을 제안한다. 또한 빠른 탐지 시간으로 발생되는 시스템의 부하와 탐지 트래픽을 최소화하는 방안도 함께 제시한다. 공격 탐지 방법은 3 단계로 구성되는데, 1 단계에서는 MIB 정보의 갱신주기를 바탕으로 탐지 시점을 결정하고, 2 단계에서는 MIB 정보간의 상관 관계를 이용하여 공격의 징후를 판단하고, 3 단계에서는 프로토콜 별 상세 분석을 통하여 공격 탐지뿐만 아니라 공격 유형까지 판단한다. 따라서 빠르고 정확하게 공격을 탐지할 수 있고, 공격 유형을 분류해 낼 수 있어 신속한 대처가 가능해 질 수있다.

• 약학회지
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• 제3권1호
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• pp.45-47
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• 1957

A paper chromatographical method is studied to detect As and Sb from a mixed sample applying the principle of Gutzeit's. After spoting the mixed $AsH_3$ sample on the $AgNO_3$ band of paper strip (6 mm $\times$ 300 mm of Whatman No.52 or Toyo No.2 filter paper), the strip is developed by ascending method using N-HCl solution as a developing soluvent. The color spot detection of As and Sb is done by exposing the dried chromatogram to $H_2S$ stream. According to the experiments, the detectable minimum range of As is 3 micrograms and that of Sb is 15 micrograms. The yellow phosphorous interfers to the color spot detection of As and Sb, so that, previously the most of yellow phosphorous from the sample should be removed out.

• International Journal of Computer Science & Network Security
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• 제21권2호
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• pp.221-228
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• 2021

Recent improvements on the quality, fidelity and availability of biometric data have led to effective human physical activity detection (HPAD) in real time which adds significant value to applications such as human behavior identification, healthcare monitoring, and user authentication. Current approaches usually use machine-learning techniques for human physical activity recognition based on the data collected from wearable accelerometer sensor from a single wearable smart device on the user. However, collecting data from a single wearable smart device may not provide the complete user activity data as it is usually attached to only single part of the user's body. In addition, in case of the absence of the single sensor, then no data can be collected. Hence, in this paper, a continuous HPAD will be presented to effectively perform user activity detection with mobile service infrastructure using multiple wearable smart devices, namely smartphone and smartwatch placed in various locations on user's body for more accurate HPAD. A case study on a comprehensive dataset of classified human physical activities with our HAPD approach shows substantial improvement in HPAD accuracy.

• 대한수의학회지
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• 제34권3호
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• pp.529-536
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• 1994

To establish more specific and simple diagnostic methods for detection of the antibodies and antigens of Aujeszky's disease virus(ADV), we designed indirect dot-immunoassay(IDI) and double sandwich dotimmunoassay(DSDI) using the solid phases of nitrocellolose paper and polystyrene plate. The diagnostic efficacy of these methods was investigated. As the sensitivity of IDI was tested by various virus concentration, the specimens with the virus titer above $10^{4.0}TCID_{50}/0.2ml$ showed positive reaction, but that below $10^{1.0}TCID_{50}/ml$ revealed negative. Tonsil emulsion at the virus titer of $10^{4.5}TCID_{50}/0.2ml$ showed the highest sensitivity as diluted by 1/100. In detection of ADV antigens from the various tissues of the rats and pigs infected with ADV, IDI using monoclonal antibody showed the higher specificity as compared with IDI using polyclonal antibody and virus isolation method. The efficacy of the DSDI for detection of ADV antibody was compared with other tests. The sensitivity of DSDI was higher than virus neutralization(VN) and agar gel immunodiffusion test(AGID). Meanwhile, specificity of DSDI was lower than AGID, but similar to IDEA. In comparison with VN test, DSDI showed 96.9% agreement to VN test that is the highest of three tests. In general, application of polyclonal antibody in both tests caused the higher sensitivity but the lower specificty.

• KIEE International Transactions on Power Engineering
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• 제3A권4호
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• pp.214-221
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• 2003

In view of the fact that gas insulated switchgear (GIS) is an important piece of equipment in a substation, it is highly desirable to continuously monitor the state of equipment by measuring the partial discharge (PD) activity in a GIS, as PD is a symptom of an insulation weakness/breakdown. However, since the PD signal is relatively weak and the external noise makes detection of the PD signal difficult, it therefore requires careful attention in its detection. In this paper, the algorithm for detection of PD in the GIS using the wavelet transform (WT) is proposed. The WT provides a direct quantitative measure of the spectral content and dynamic spectrum in the time-frequency domain. The most appropriate mother wavelet for this application is the Daubechies 4 (db4) wavelet. 'db4', the most commonly applied mother wavelet in the power quality analysis, is very well suited to detecting high frequency signals of very short duration, such as those associated with the PD phenomenon. The proposed algorithm is based on utilizing the absolute sum value of coefficients, which are a combination of D1 (Detail 1) and D2 (Detail 2) in multiresolution signal decomposition (MSD) based on WT after noise elimination and normalization.

• 한국임상수의학회지
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• 제25권4호
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• pp.241-244
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• 2008

본 연구는 특이적인 임상증상이 없는 360두의 개를 대상으로 multiplex nested PCR 기법을 이용하여 Brucella spp. 및 Leptospira interrogans를 검출하였다. Brucella spp.는 총4두 (1.1%, 암컷 2두, 수컷 2두)가 검출되었고, Leptospira interrogans는 59두 (16.4%, 암컷31두, 수컷28두)에서 검출되었다. 결론적으로 Brucella spp.의 검출률은 낮은 반면 Leptospira interrogans는 높았다. 또한 multiplex nested PCR기법은 무증상의 개 혈액에서 Brucella spp. 및 Leptospira interrogans를 조기에 검출하는데 빠르고 편리한 기법으로 판단된다.

• Journal of Photoscience
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• 제9권2호
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• pp.527-529
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• 2002

Photodynamic therapy (PDT) is a medical treatment using laser and photosensitizing drug taken up to destroy cancer cells. Singlet oxygen ($^1$0$_2$) generation is strongly related to this treatment. We have built a direct detection system monitoring feeble luminescence, in the near IR region, from $^1$0$_2$, We have comparatively studied the photophysical and photochemical properties in solution of a newly developed drug ATX-S10 and Photofrin already investigated clinically. We demonstrdted that ATX-S10 was capable of efficiently yielding $^1$0$_2$, which may lead to highly efficient PDT treatment. Successive laser excitation photobleached ATX -S10 readily in a dose-dependent manner. This result shows that ATX -S10 is useful in setting up suitable medical treatment conditions to minimize side effects.

• 미생물학회지
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• 제44권2호
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• pp.130-134
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• 2008

미생물 자동배양기를 이용한 감염성 물질의 검출은 시험적 오차의 경감은 물론 분리율 향상과 시간 단축을 가능하게 하였다. BacT/ALERT 3D 자동배양기는 미생물성장 시 발생되는 이산화탄소를 비색법으로 검출하는 장비로서 임상시료를 이용한 미생물 배양과 검출에 이용되어왔다. 자동배양기의 효율성을 검증하고 의약품의 무균 시험에 적용가능한지를 평가하기 위하여 6종의 세균을 이용하여 중식 및 검출특성을 분석하였다. 3종의 호기성세균 Pseudomonas aeruginosa, Micrococcus Iuteus, Bacillus subtilis와 Staphylococcus aureus는 1 CFU가 31.44 시간 내에 검출되었고, 혐기성균인 Clostridium sporogenes는 15.96시간에 균의 중식이 감지되었다. 저성장 혐기성세균인 Propionibacterium acnes는 $10^4$ CFU의 균수에서 검출에 129.36시간이 소요되었다. 이 같은 결과는전통적 직접 배양법보다 검출감도에 있어서 $10\sim10^5$배 높고 검출시간을 $2\sim10$10시간 단축한 것으로서 자동배양법이 미생물 증식과 검출에 효율적임을 말해준다. 따라서 본 시험에서 이용한 자동배양법은 임상시료에서의 감염원 진단뿐 아니라 생물의약품의 무균시험에 이용 가능하다고 판단된다.

• 정보보호학회논문지
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• 제7권3호
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• pp.53-64
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• 1997

고속 데이터 통신을 위한 T1 전송시스템에 동기식 스트림암호를 적용시 수신 데이터는 매우 긴 비트 간격 동안 연속해서 "0" 또는 "1"이 발생될 수 있다. 이러한 경우 수신클럭 복구가 어려울 뿐 아니라 통신규약을 위반하게 된다. 본 논문에서는 T1 전송시스템에 동기식 스트림암호를 적용시 출력단에서 암호문의 연속 "0" 비트수를 k( $\geq$ 2) 이하로 억제하는 블록검출방식과 직렬검출방식(ZS, Zero Suppression)을 제안한다. 제안된 ZS방식들은 암호학적 비도를 유지하면서 스트림동기 문제를 효과적으로 해결한다.도를 유지하면서 스트림동기 문제를 효과적으로 해결한다.