• Analytical Science and Technology
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• v.12 no.4
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• pp.332-340
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• 1999

Homemade cryogenic preconcentration system is constructed to preconcentrate the VOCs in the ambient air collected in canister. Homemade preconcentrator equipped with GC-MS was used for analysis of air sample containing VOCs at ppb level identified in EPA TO-14 method. The system was evaluated for analytical performance by comparison with the results of adsorption tube method widely used in the past, and shows good agreement for concentrations of benzene, toluene, ethylbenzene, and xylenes.

• Journal of Korean Society of Forest Science
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• v.86 no.3
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• pp.334-341
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• 1997

Artificial precipitation test with sprinkler system was carried out to develop the collection method of arboreal larvae(proctotrupoid wasps) of pine needle gall midge for biological control in 1995. Effects of larvae falling on each amount of precipitation, season of precipitation and time of precipitation of a day following artificial precipitation were examined during the period of larvae falling season. The results obtained were summarized as follows; 1. Artificial precipitation with sprinkler system was highly effective for collection of pine needle gall midge larvae and the most suitable amount of precipitation was 5.3-9.4mm; application amount and hours of water were $8,000-16.000{\ell}$ and 180-360 minutes, respectively. 2. The most effective period of larvae collection for artificial precipitation was approximately 20 days, from early through mid November, and larvae falling was 93.4% of the total number of larvae collection during this period. 3. Larvae falling from the tree crown was not affected by the artificial precipitation for the precipitation hour intervals in a day. 4. The percentage of parasitism of collected larvae of pine needle gall midge in November exceeded that of December but was not significantly different between two seasons. 5. Artificial precipitation of sprinkler system was effective in reducing 34% of gall formation after one year at collected sites of pine needle gall midge larvae. 6. The collection method of larvae following artificial precipitation was effective in reducing the expenses by 14-50% than that of collection method of infested needles.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.7
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• pp.867-872
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• 2010

Unused energy derived from sources in nature can be captured and stored for future use, for example, to recharge a battery or power a device; this process of capturing and storing energy is called energy harvesting. Extensive investigations are being carried out in order to use piezoelectricity to harvest the energy generated by body movements or machine vibrations. This paper presents a simple analytical model that describes the output voltage effectiveness of a Piezocomposite Generating Element (PCGE) from vibration and its experimental verification. PCGE is composed of carbon/epoxy, PZT, and glass/epoxy layers. During the manufacturing process, the stacked layers were cured at $177^{\circ}C$ in an autoclave, which created residual stresses in PCGE and altered the piezoelectric properties of the PZT layer. In the experiments, three kinds of lay-up configurations of PCGE were considered to verify the proposed prediction model and to investigate its capability to convert oscillatory mechanical energy into electrical energy. The predicted performance results are in good agreement with observed experimental ones.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.6
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• pp.679-685
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• 2011

This paper presents an algorithm identifying devices that generate observed mixed signals that are collected at main power-supply line. The proposed algorithm, which is necessary for low cost electric power monitoring system at appliance-level, that is non-intrusive load monitoring system, divides incoming mixed signal into multiple time intervals, calculating difference-signals between consecutive time interval, and identifies which device is operating at the time interval by analysing the difference-signals. Since the features of one device can remain when the time interval is short enough and the features are independent and additive, well-known classification algorithms can be used to classify the difference-signals with features of N individual devices, otherwise $2^N$ features might be necessary. The proposed algorithm was verified using data mixed in a laboratory with individual devices's data collected from field. When maximum 4 devices operate or stop sequentially and when features satisfy the requirements of proposed algorithm, the proposed algorithm resulted nearly 100% success rate under the constrained test condition. In order to apply the proposed algorithm in real world, the number devices shall increase, the time interval shall be smaller and the pattern of mixture shall be more diverse. However we can expect, if features used follow guidelines of proposed algorithm, future system could have certain level of performance without the guideline.

• Journal of Sericultural and Entomological Science
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• v.47 no.2
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• pp.93-98
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• 2005

The antioxidant capacity of yield-type mulberry leaves and fruits (Morus alba L., M. bombycis Koidz, and M. Lhou (Ser). Koidz) collected from In-je, Won-ju and Yang-yang regions, Kang-won province, Korea, was investigated with minium L-100 device and ARAW-KIT (anti-radical ability of water-soluble substance), in comparison to the ascorbic acid. The results indicated that total antioxidant capacity of yield-type mulberry leaves was 2711.2 nmol (ascorbic acid equivalents). The highest stage of antioxidant capacity (3587.6 nmol) was opening stage of five leaves in spring. Especially, antioxidant capacity of mulberry leave collected from In-je region was high than that of other regions. No. 7 mulberry leave showed the strongest antioxidant capacity (6184.9 nmol) at opening stage of five leaves in spring. Also, fluit growing condition including fruit size and yield was good, too. Therefore, No. 7 mulberry three from In-je region, possessed not only high antioxidant capacity but also considerable fruit quality, was selected as potent resource for mulberry breeding and functional material development.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.2
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• pp.141-145
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• 2000

The daily fluctuations of occurrence rate and standing stock of zooplankton, the relationship between dry and wet weights of gelatinous zooplankton, and the size distributions of body length and body weight of zooplankton were investigated in the sea around Cheju Island from September 1996 to August 1997. Mean ratios of wet to dry weights were 66.46 (raging from 47.05 to 84.64) in the gelatinous zooplankton and 10.89 (raging 9.21 to 14.85) in the non-gelatinous zooplankton which consisted of crustaceans such as copepods, decapods, mysids, and ostracods etc. Rarios of gelatinous zooplankton to non-gelatinous zooplankton (G/NG) in wet weight was 0.99 (0.28-2.30), indicating high occurrence rate of gelatinous in the study area. The seasonal and diel fluctuations of the gelatinous zooplankton were very large, and G/NG ratios greatly varied with seasons and dat/night cycles. The size distributions of body length of zooplankton (250-500 urn: 35.5% in maximum), and wet (0.1-0.2 mg: 34.4%) and dry weights (0.025-0.05 mg: 44.8%) showed much difference depending composition of the zooplankton groups. These results show that quantitative estimations of zooplankton produc- tivity only based on wet weight should be corrected to better understand and evaluate marine resources in Korean waters.

• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.3
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• pp.9-15
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• 1999

The Analysis of spray characteristics for combined spray group are necessary to develop large rocket engine. In this study, basic effects of interaction from spray fan formed by impinging jets were investigated with respect to mass distribution, droplet velocities and diameter. Patternater and PDPA are used for experimental apparatus. Water was used as a test fluid When momentum ratio is 1, effect of interaction from collision of spray fan on mass distribution are small. Also, effect of interaction from collision of spray fan on droplet velocities and diameter are small. But, droplet diameter is smaller near collision point due to second collision. Therefor, for the same momentum ratio from spray fan formed by impinging jets, we may neglect effect of interaction on mass distribution, droplet velocities and diameter.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.827-829
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• 2013

생체인식을 통한 개인 인증방법에는 지문인식과, 홍채인식 등이 활발하게 연구가 진행되고 있다. 본 논문에서는 생체인식을 통한 개인 인증 방법 중 우측 검지손가락 정맥을 이용한 방법을 사용하였다. 적외선 LED 8개를 이용하여 적외선을 손가락에 투과하여 CMOS카메라를 통하여 영상을 획득하는 정맥인식장치를 개발하고 영상을 채집한다. ROI영역을 추출하여 손가락 정맥인식을 위한 영상부분만 추출한다. 추출된 영상을 통하여 미디언 필터를 이용하여 noise를 제거하고 히스토그램 평활화를 통한 정맥영역을 부각시킨다. 특히 지역적 히스토그램 평활화를 통해서 보다 정확한 정맥의 영역을 찾는다. 지역적 히스토그램 평활화를 통한 영상을 이진화를 시키고 세선화를 통해서 이후 패터매칭을 통한 개인 인증방법에 대한 전처리 영상을 구한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1289-1292
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• 2010

용수부족 현상을 극복하기 위하여 댐건설 등의 생태계의 교란을 일으키는 방안을 배제하고 친생태적인 우수이용 등의 대체수자원을 개발하여 수자원 이용효율을 높이는 방안이 중요시 되고 있다. 이에 본 연구에서는 초기우수의 수질특성과 대기의 상태에 크게 영향을 미치는 수문학적 요인인 선행강우에 따른 수질변화에 대하여 분석하였다. 시료채취기간은 2001년 11월 22일에서 2003월 7월 06일까지 발생한 5mm 이상 호우사상을 대상으로 26회 에 걸쳐 초기 우수를 채집하여 분석을 실시하였으며, 이 중 봄 12회, 여름 7회, 가을 2회, 겨울 5회였다. 강우량 규모는 5~10mm인 호우가 5회, 10~20mm인 호우가 9회, 20mm~30mm인 호우가 5회, 30mm~50mm 인 호우가 2회, 50mm~100mm인 호우가 3회, 100mm~200mm인 호우가 2회였으며, 이를 채취하여 탁도, 증발잔유물, BOD, NH3-N, ${SO_4}^{-2}$, 전기 전도도 등의 항목을 측정하였다. 우수수질은 강우가 지속됨에 따라 급격히 개선되었으며, 이에 대한 상관관계도 높게 분석되었다.

• Journal of the Korea Convergence Society
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• v.10 no.10
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• pp.75-80
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• 2019

During the medical ultrasound exercise at school, we randomly select parts of the ultrasound device and areas with the most contact in the abdominal phantom to detect bacteria that are above the probe and determine the number of pathogens. I want to find out. The experimental method was rubbed 20 times with the sterilized cotton swab for sterilization and then smeared on Lysogeny broth (LB) agar, put into the incubator and incubated for 48 hours, and the colony forming unit (CFU) count was measured. The bacterial distribution of probe handle and abdominal phantom was evaluated by evaluation. As a result, the CFU value is the lens was $3.0{\pm}0.87$, print button was $5.5{\pm}1.06$, freeze button was $8.0{\pm}4.95$, phantom was $20.0{\pm}2.78$, line was $23.5{\pm}2.50$, and probe handle was measured as $35.3{\pm}10.75$. In this study, it is expected that attention to infection control of equipment during practice during medical ultrasound practice can be highlighted and further contributed to the reduction of bacterial infection rate of ultrasound devices.