• 한국인터넷방송통신학회논문지
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• 제21권6호
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• pp.1-8
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• 2021

몰카범죄의 증가에 발맞추어 은닉형 카메라는 스마트폰의 기술발전 속도에 따라 소형화 및 기술 집적이 고도화되어 성능이 날로 발전하고 있다. 이러한 외적인 네트워킹 컴퓨팅 환경이 고도화 되고, 활동이 많은 현대인의 생활양상이 다양화됨에 따라 일반 안전용 카메라외에 은닉형 카메라에 노출 또한 증가되고 있는 추세이다. 반면 은닉형 카메라를 탐지하고 예방하기 위한 기술은 이러한 은닉형 카메라 기술발전과 속도를 따라가지 못하고 있는 실정이다. 이에 본 연구에서는 일반영상과 열화상 이미지 합성기술을 바탕으로 적외선 열 방식의 탐지기술을 이용하여 은닉카메라의 발열을 감지하고, 주변 온도 차이에 따른 각 파장의 반사율을 분석하여 오탐율도 줄이도록 하였다.

• 한국임상수의학회지
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• 제35권6호
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• pp.251-257
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• 2018

We determined the relationships between calving season and the incidence of postpartum disorders, milk yield, and reproductive performance in dairy cows. Data regarding cow parity, postpartum disorders, milk yield, and reproduction were collected from 1,478 lactations. The incidence of retained placenta was higher in spring- and summer-calving cows than in autumn- and winter-calving cows (P < 0.05). The incidence of septicemic metritis was highest in spring- and summer-calving cows, and was higher in autumn-calving cows than in winter-calving cows (P < 0.05). The incidence of metabolic disorders was higher in summer-calving cows than in autumn- and winter-calving cows (P < 0.01). The mean milk yield 1 and 2 months after calving was higher in spring-calving cows than in summer-calving cows (P < 0.05). The percentage of cows that had resumed cycling, defined by detection of a corpus luteum using ultrasonography 4 weeks after calving, was highest in autumn-calving cows, and was higher in summer- and winter-calving cows than in spring-calving cows (P < 0.05). The hazard of first insemination by 150 days after calving was higher in summer- and autumn-calving cows (hazard ratio [HR] = 1.19; P < 0.05) than in spring-calving cows. The hazard of pregnancy by 210 days after calving was also higher in summer-calving (HR = 1.24; P < 0.05) and autumn-calving (HR = 1.59; P < 0.0001) cows than in spring-calving cows. The probability of conception at the first insemination was higher (P < 0.0001) in autumn-calving (odds ratio [OR] = 1.96) and winter-calving (OR = 2.04) cows than in spring-calving cows. In conclusion, spring calving is associated with the worst, and autumn calving with the best, postpartum health and reproductive performance, whereas milk yield is higher in spring-calving cows than in summer-calving cows. Therefore, an effective strategy to support postpartum health and fertility should be instituted for spring-calving dairy cows kept in the Korean climate.

• Corrosion Science and Technology
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• 제19권6호
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• pp.296-301
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• 2020

Failure analysis on the welded type 304 pipe used for cooling water piping in the district heating primary side was conducted. Inorganic elements and bacteria in the cooling water and in corrosion products were analyzed, and the weldment was inspected by microscopy and a sensitization test. Corrosion damages were observed in the heat-affected zone, on weld defects such as incomplete fusion or excessive penetration caused by improper welding, or/and at the 6 o'clock position along the pipe axial direction. However, the level of concentration of chloride in the cooling water as low as 80 ppm has been reported to be not enough for even a sensitized type 304 steel, meaning that the additional corrosive factor was required for these corrosion damages. The factor leading to these corrosion damages was drawn to be the metabolisms of the types of bacteria, which is proved by the detection of proton, sulfur containing species, biofilms, and both bacteria and corrosion product analyses.

• 한국추진공학회지
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• 제24권5호
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• pp.34-42
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• 2020

현대 항공전에서 적외선 신호는 상대방 탐지에 있어 중요한 역할을 하며, 생존성 및 스텔스성 향상을 위해 저감되어야 한다. 특히 항공기 엔진 후류에서 발생하는 적외선 신호는 높은 강도를 가지며 파장이 짧아 대부분의 열 추적 미사일이 이러한 신호를 따라 탐지하게 된다. 이에 따라 본 연구에서는 엔진 후류에서 발생하는 Gas radiation 신호 측정 및 특성 분석을 수행하였다. 실제 항공기 터보팬 엔진을 모사하기 위해 마이크로 터보제트 엔진을 구성하였으며, 바이패스 비 조절을 통한 적외선 신호 저감 특성을 파악하였다. 이를 통해 각 파장 별 적외선 신호 특성을 분석하고 신호 저감 기술들에 대한 검증을 수행한다.

• 한국전기전자재료학회논문지
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• 제35권4호
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• pp.412-417
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• 2022

Capacitive-type humidity sensors with a high sensitivity and fast response/recovery times have attracted a great attention in non-contact respiration biological signal monitoring applications. However, complicated fabrication processes involving high-temperature heat treatment for the hygroscopic film is essential in the conventional ceramic-based humidity sensors. In this study, a non-toxic ceramic/metal halide (BaTiO₃(BT)/NaCl) humidity sensor was prepared at room temperature using a solvent-free aerosol deposition process (AD) without any additional process. Currently prepared BT/NaCl humidity sensor shows an excellent sensitivity (245 pF/RH%) and superior response/recovery times (3s/4s) due to the NaCl ionization effect resulting in an immense interfacial polarization. Furthermore, the non-contact respiration signal variation using the BT/NaCl sensor was determined to be over 700% by maintaining the distance of 20 cm between the individual and the sensor. Through the AD-fabricated sensor in this study, we expect to develop a non-contact biological signal monitoring system that can be applied to various fields such as respiratory disease detection and management, infant respiratory signal observation, and touchless skin moisture sensing button.

• 한국수산과학회지
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• 제55권2호
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• pp.218-223
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• 2022

Cholesterol is an essential component for maintaining health; however, excessive consumption can lead to diseases. Thus, continuous monitoring of cholesterol content is important in food research. The cholesterol analysis method used in Korea follows the Korean Food Standards Codex. As this method uses gas chromatography, derivatization of the sample is required, and analysis time is more than 30 min. Kim developed a new method using liquid chromatography; however saponification by the non-heat saponification method is insufficient. To address these limitations, a new cholesterol analysis method was developed and verified. The correlation coefficients for the cholesterol standard (STD) were maintained above 0.99. The limit of detection and limit of quantitation of cholesterol STD were 2.41 ㎍/mL and 7.31 ㎍/mL, respectively. The accuracies for cholesterol were 92.21-99.02%. The developed analytical method was also verified using three standard reference materials, and their accuracies were 93.71-97.09%. In addition, the cholesterol content of fishes was analyzed, and the values were compared with those recorded by the United States Department of Agriculture. Our results suggest that this method could be used as a new analytical method for cholesterol in seafood.

• Composites Research
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• 제36권3호
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• pp.217-223
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• 2023

본 연구에서는 폴리아크릴로니트릴계 탄소나노섬유 스펀지의 제조 및 오일 흡착 거동을 조사하였다. 제조된 탄소나노섬유 스펀지는 물과 기름의 혼합용액에서 우수한 선택적 오일 흡착 능력을 보였으며, 탄소나노섬유 스펀지의 재사용시 흡착 능력도 확인하였다. 또한, 흡착제 내부구조에 정렬된 채널을 형성함으로써, 모세관 현상에 의하여 빠른 오일 흡착 거동을 보이는 탄소나노섬유 스펀지를 제조할 수 있었다. 이후 사용 폐기된 탄소나노섬유 스펀지는 질소 분위기에서 800℃로 열처리하여, 4-아미노페놀의 전기화학적 검출을 위한 센서로의 가능성을 검토하였다.

• 분석과학
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• 제21권2호
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• pp.117-122
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• 2008

표면오염도 측정용 검출소재로 주로 이용되고 있는 알파와 베타선의 동시 측정용 이중섬광체 검출소재를 개발하였다. 본 연구에서는 기존의 열용융 공정이 아닌, 고분자 소재를 용매로 녹여서 검출소재를 제조하는 용매법을 이용함으로써 제조공정을 단순화하였다. 베타선 측정용 플라스틱 섬광체는 유기섬광체, 고분자, 그리고 용매가 혼합된 용액을 도말한 후에 고형화하여 제조하였다. ZnS(Ag) 섬광체는 플라스틱 섬광체 위에 ZnS(Ag), 접착소재, 그리고 용매가 혼합된 용액을 스크린 프린팅 방법으로 도포하여 제조하였다. 제조한 이중섬광체의 알파선과 베타선에 대한 방사능 검출 성능을 평가한 결과 우수한 검출 성능을 확인하였으며, 표염오염도 측정용 소재로 적용이 가능함을 확인하였다.

• 복식문화연구
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• 제31권1호
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• pp.107-123
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• 2023

This research studied the electrical characteristics, IR transmission characteristics, stealth functions, and thermal characteristics of infrared thermal-imaging cameras of copper-sputtered samples. Nylon samples were prepared for each density as a base material for copper-sputtering treatment. Copper-sputtered NFi, NM1, NM2, NM3, NM4, and NM5, showed electrical resistance of 0.8, 445.7, 80.7, 29.7, 0.3, and 2.2 Ω, respectively, all of which are very low values; for the mesh sample, the lower the density, the lower the electrical resistance. Measuring the IR transmittance showed that the infrared transmittance of the copper-sputtered samples was significantly reduced compared to the untreated sample. Compared to the untreated samples, the transmittance went from 92.0-64.1%. When copper sputtered surface was directed to the IR irradiator, the IR transmittance went from 73.5 to 43.8%. As the density of the sample increased, the transmittance tended to decreased. After the infrared thermal imaging, the absolute values of △R, △G, and △B of the copper phase increased from 2 to 167, 98 to 192, and 7 to 118, respectively, and the closer the density of the sample (NM5→NFi), the larger the absolute value. This proves that the dense copper phase-up sample has a stealth effect on the infrared thermal imaging camera. It is believed that the copper-sputtered nylon samples produced in this study have applications in multifunctional uniforms, bio-signal detection sensors, stage costumes, etc.

• Journal of Dairy Science and Biotechnology
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• 제41권3호
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• pp.103-112
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• 2023

This study aimed to assess the effectiveness of 10 different pre-enrichment methods using Real-Time polymerase chain reaction (PCR) in support of the FDA method. When the initial Cronobacter spp. (Enterobacter sakazakii) inoculation was 7.2 CFU/g, the Ct values were observed in the following order: 21.37 (Enterobacteriaceae enrichment [EE] broth), 21.95 (brain heart infusion [BHI]), 22.72 (tryptic soy broth [TSB]), 23.02 (violet red bile lactose [VRBL]), 22.31 (TSB-0.1% sodium pyruvate [SP]), 23.43 (distilled water [DW]), 24.34 (phosphate buffered saline [PBS]), 24.95 (nutrient broth [NB]), 25.82 (TSB-0.6% yeast extract [YE]), and 28.27 (violet red bile glucose [VRBG]). For an inoculation of 1.82% CFU/g of Cronobacter spp. (E. sakazakii), the Ct values were recorded in this sequence: 20.34 (EE broth), 22.16 (TSB-0.6% YE), 22.37 (BHI), 22.71 (VRBL), 22.88 (TSB), 23.01 (DW), 23.19 (NB), 23.79 (TSB-0.1% SP), 24.66 (VRBG), and 24.70 (PBS). Finally, when the inoculum of Cronobacter spp. (E. sakazakii) was 0.182 CFU/g, the Ct values followed this order: 21.93 (VRBL), 23.07 (TSB-0.6% YE), 23.31 (DW), 23.47 (PBS), 23.70 (BHI), 24.14 (TSB-0.1% SP), 25.14 (TSB), 29.00 (VRBG), 31.55 (EE broth), and were undetected in the case of NB. Consequently, these results indicate that there were no significant differences among the 10 different pre-enrichment broths. Future studies should focus on exploring pre-enrichment broths that can improve the limit of detection at very low Cronobacter spp. (E. sakazakii) concentrations and enhance the selective recovery of Cronobacter spp. (E. sakazakii) under acid, antibiotic, cold, and heat damage conditions.