• 한국환경교육학회지:환경교육
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• 제13권2호
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• pp.91-102
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• 2000

National curriculum for environmental education recommends various teaching-learning methods including survey and discussion of environmental problems, investigation of case studies, experiments, role play, and field-experience learning in addition to the traditional lecture-oriented teaching methods. The field experience learning in environmental education is considered to be a good method to develop environmentally sound attitude and to cultivate environmental sensitivity, but here has been very limited research concerning models for field-experience learning. The aim of this study is to develop a model of the field-experience learning program of environmental education utilizing environmental facilities. In this study a kind of such a basic model was developed and presented. The developed basic model of the field-experience learning was applied to the case utilizing landfill facilities. A specific application of the landfill program to the Bangcheon-ri landfill, in Daegu, was also presented with related teaching materials developed in this studies. And various aspects in the program was discussed.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1191-1196
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• 2009

The T-s chart of air displays graphically the thermophysical properties, so it is very conveniently used in various thermal systems. In previous study, the software analyzing 31 kinds of values in water system and 32 kinds of values in air-conditioning system were developed. In this study, the software drawing 13 kinds of quantity of state on air properties as ideal gas and analyzing 25 kinds of values in any air system was developed. The 13 kinds of quantity of state on air properties are temperature, pressure, specific volume, specific internal energy, specific enthalpy, specific entropy, specific exergy, exergy ratio, density, isobaric specific heat, isochoric specific heat, ratio of specific heat, and velocity of sound, and the 25 kinds of values including 13 kinds are mass flow rate, volume flow rate, internal energy flow rate, enthalpy flow rate, entropy flow rate, exergy flow rate, heat flow rate, power output, power efficiency, reversible work, lost work, and relative humidity. The developed software can draw any range of chart and analysis any state or process on air system. Also, this supports various document-editing functions such as power point. We wish to this chart is a help to design, analysis, and education in air system field.

• 한국작물학회지
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• 제50권4호
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• pp.238-246
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• 2005

Rice yield and protein content have been shown to be highly variable across paddy fields. In order to characterize this spatial variability of rice within a field, two-year experiments were conducted in 2002 and 2003 in a large-scale rice field of $6,600m^2$ In year 2004, an experiment was conducted to know if variable rate treatment (VRT) of N fertilizer, that was prescribed for site-specific management at panicle initiation stage, could reduce spatial variation in yield and protein content of rice while increasing yield compared to conventional uniform N topdressing (UN, 33kg N/ha at PIS) method. VRT nitrogen prescription for each grid was calculated based on the nitrogen (N) uptake (from panicle initiation to harvest) required for target rice protein content of $6.8\%$, natural soil N supply, and recovery of top-dressed N fertilizer. The required N uptake for target rice protein content was calculated from the equations to predict rice yield and protein content from plant growth parameters at panicle initiation stage (PIS) and N uptake from PIS to harvest. This model· equations were developed from the data obtained from the previous two-year experiments. The plant growth parameters for the calculation of the required N were predicted non-destructively by canopy reflectance measurement. Soil N supply for each grid was obtained from the experiment of year 2003, and N recovery was assumed to be $60\%$ according to the previous reports. The prescribed VRT N ranged from 0 to 110kg N/ha with an average of 57kg/ha that was higher than 33 kg/ha of UN. The results showed that VRT application successfully worked not only to reduce spatial variability of rice yield and protein content but also to increase rough rice yield by 960kg/ha. The coefficient of variation (CV) for rice yield and protein content was reduced significantly to $8.1\%$ and $7.1\%$ in VRT from $14.6\%$ and $13.0\%$ in UN, respectively. And also the average protein content of milled rice in VRT showed very similar value of target protein content of $6.8\%$. In conclusion the procedure used in this paper was believed to be reliable and promising method for reducing within-field spatial variability of rice yield and protein content. However, inexpensive, reliable, and fast estimation methods of natural N supply and plant growth and nutrition status should be prepared before this method could be practically used for site-specific crop management in large-scale rice field.

• 한국농림기상학회지
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• 제17권4호
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• pp.317-325
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• 2015

우리나라 농촌은 지형이 복잡하고 소규모 농장이 많아 농업기상서비스 개선을 위해서는 먼저 기상청 종관 예보의 규모축소가 필요하다. 지형기후학에 근거한 공간정보기술을 이용하여 기상청의 기온예보자료 가운데 0600과 1500 LST자료를 선정된 집수역에 대해 30 m급의 국지규모로 상세화하고, 14개 관측소의 실측기온 자료를 2013년부터 2014년까지 수집하여 비교하였다. 그 결과 0600 LST기온의 경우 집수역 가운데 고도가 낮은 곳에서, 1500 LST 기온의 경우 계곡의 서향 및 남향 사면에서 정확도가 크게 개선되는 것을 확인하였다. 상세화 한 기온실황자료를 이용하여 지역 내 소규모 농장을 대상으로 하는 시범서비스를 시작하였으며 농장 맞춤 기상정보를 제공하고 있다. 예컨대 이 서비스시스템은 기온자료를 토대로 작물의 발육단계를 추정하고, 발육단계별 최저기온에 따른 서리해 발생 관계식에 의해 내일 아침 예보기온의 서리위험 여부를 판정한다. 만약 서리위험도가 미리 설정된 기준을 넘으면 농장주의 휴대폰으로 대응지침과 함께 서리해 경보를 발송하여 피해를 예방할 수 있도록 도와준다.

• Journal of Radiation Protection and Research
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• 제22권4호
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• pp.299-307
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• 1997

점선원 주위에 형성되는 방사상의 감마선장에서 개인선량당량 $H_p$, 유효선량 E, 성별 유효선량 $E^m$과 $E^f$를 MIRD형 남녀 모의 피폭체를 이용하여 평가하였다. 선원은 신체의 전방 각각 15, 40 및 100 cm 거리의 여러 높이에 있는 것으로 하였고 방사성 핵종으로는 시범적으로 $^{137}Cs$과 $^{131}I$을 선정하였다. 성별 유효선량에서는 일부 예외적인 경우-예를 들면 선원이 생식선 앞에 위치할 때-를 제외하고는 대체로 여성의 경우가 크게 나타났으나, 남녀 평균값과의 차이는 크지않아 방사상 감마선장에서 성별 유효선량환산인자를 사용할 필요성은 없었다. 선량계를 가슴에서 하복부까지의 몸통 전방에 착용할 경우에는 $H_p$/E의 비가 약$1{\sim}3$의 범위에 있었고 극단적인 경우는 0.34에서 6.5까지 큰 편차를 보였다. 그러나 일반적인 방사선원 취급방법과 선량계 착용위치(흉곽 전방)를 가정하고, 선량계가 넓고 평행한 방사선장에서 유효선량에 대해 교정된다면 평행하지는 않지만 넓은 빔인 방사상 감마선장에 대해서는 용인할 수 있는 오차의 범위에서 유효선량 평가치를 제공할 수 있을 것으로 나타났다.

• 한국전자파학회논문지
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• 제15권3호
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• pp.291-300
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• 2004

이동통신 서비스의 급격한 증가로 인해, EMF(Electromagnetic field)노출의 생물학적 효과에 대한 많은 연구들이 수행되어져 왔다. 그러나 연구 수행에 있어서 필요한 무선 주파수 대역에서의 균일장 생성은 쉬운 일이 아니다. 이러한 어려움을 극복하기 위해 전신노출 시 스템에서의 전기장과 SAR(Specific Absorption Rate) 분포 측정이 발전을 해왔다. 본 논문에서는 EMC 대용 챔버로의 활용 가능성이 높은 전자파 잔향실 챔버를 이용하여 동물 실험용 전신 노출 장치를 개발하였다. 설계된 전자파 잔향실은 시뮬레이션과 측정 데이터를 이용하여 시험영역의 균일장에 대한 유효성을 검증하였다. 마우스에 대한 전신노출 실험에 있어서, 노출된 전자파에 대해 SAR을 확인하기 위해서 FDTD수치해석 방법과 측정 결과를 비교하였다. 전자파 잔향실 내부에서의 전기장 분포 특성을 해석하고, 이러한 해석 결과들을 통계적으로 처리하였다. CDMA 이동전화 주파수 대역에서(PCS ＆ Cellular 대역) 입력 파워 변화에 따른 실험상태에서의 마우스 전신 SAR 평균값 및 국부 최대값을 제시하였다.

• 대한수의학회지
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• 제38권1호
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• pp.53-63
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• 1998

Total of 1085 swine sera (1996-1997) from nation-wide were tested for the presence of antibodies to influenza A virus. Fifty nine percent of the tested sera showed seropositive by HI test. Positive sera consisted of 24--- of H3, 15--- of H1, and 20--- of the sample had both antibodies, respectively. Sera collected from various region represented 7~27--- seropositivity to H1N1, 15~25--- to H3N2, respectively. Swine influenza field isolate from nasal swab was characterized antigenically and genetically to elucidate its relatedness with other known strains of influenza A virus. The study was focused on the HA gene which is related to pathogenecity and antigenic variability of the influenza virus. By RT-PCR using influenza A/H1N1 specific primers, influenza virus H1N1 specific DNA fragment was amplified from A/Swine/Iowa/15/30(H1N1), US field isolate but not in H3N2 strain. PCR products were sequenced by dideoxy chain termination method to determine nucleotide homology with other strains of influenza A virus. The US field isolate and A/Swine/Indiana/1726/88 strain had 97--- of nucleotide homology and 98--- of amino acid homology. Based on the results obtained from this experiment, the field isolate was genetically related to A/Swine/Indiana/1726/88 and had higher homology with A/Swine/Indiana/1726/88 than with classical swine influenza virus, A/Swine/Iowa/15/30. The field isolate had no amino acid changes at the antigenic site compare to that of the A/Swine/Indiana/1726/88. The proteolytic enzyme cleavage site between HA1 and HA2 had no alteration and the amino acid arginine was intact. There is no evidence has been found that the field isolate has genetic shift or genetic drift which might altered antigenic determinant.

• 한국전기전자재료학회논문지
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• 제35권5호
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• pp.459-465
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• 2022

This paper reports a method to use a wireless sensor network deployed in the field to real-time monitor soil moisture, warning when the moisture level reaches a specific value, and wirelessly controlling an additional device (LED or water supply system, etc.). In addition, we report all processes related to wireless irrigation system, including field deployment of sensors, real-time monitoring using a smartphone, data calibration, and control of additional devices deployed in the field by smartphone. A commercially available open-source Internet of Things (IoT) platform, NodeMCU, was used, which was combined with a 9V battery, LED and soil humidity sensor to be integrated into a portable prototype. The IoT-based soil humidity sensor prototype deployed in the field was installed next to a tree for on-site demonstration for the measurement of soil humidity in real-time for about 30 hours, and the measured data was successfully transmitted to a smartphone via Wifi. The measurement data were automatically transmitted via e-mail in the form of a text file, stored on the web, followed by analyses and calibrations. The user can check the humidity of the soil real-time through a personal smartphone. When the humidity of a soil reached a specific value, an additional device, an LED device, placed in the field was successfully controlled through the smartphone. This LED can be easily replaced by other electronic devices such as water supplies, which can also be controlled by smartphones. These results show that farmers can not only monitor the condition of the field real-time through a sensor monitoring system manufactured simply at a low cost but also control additional devices such as irrigation facilities from a distance, thereby reducing unnecessary energy consumption and helping improve agricultural productivity.

• ETRI Journal
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• 제21권3호
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• pp.22-28
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• 1999

A new tapered TEOS oxide technique has been developed to use field oxide of the power integrated circuits. It provides better uniformity of less than 3 % and reproducibility. On-resistance of P-channel RESURE (REduced SURface Field) LDMOS transistors has been optimized and improved by using a novel simulation and tapered TEOS field oxide on the drift region of the devices. With the similar breakdown voltage, at $V_{gs}$=-0.5V, the specific on-resistance of the LDMOS with the tapered field oxide is about $31.5{\Omega}{\cdot}cm^2$, while that of the LDMOS with the conventional field oxide is about $57m{\Omega}{\cdot}cm^2$.

• 정보학연구
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• 제12권2호
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• pp.49-55
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• 2009

Currently the Web, multiple files in the Client to upload to the server of the multi-upload method, files are stored in specific folders on the server, the file name field in DB(Database Field) stored in a way that the process has been widely utilized. Therefore, a minimum number of file upload as many file names in the Database and the Table should be created in the field, but also a variable number of files can be uploaded has no limits. In this paper we proposed the new method that files to be uploaded to the server, you can upload a limited number of files, nor due to upload files to reduce load on the database to improve the processing speed of a single field using a multi-method file uploads using PHP directly implemented