• 원예과학기술지
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• 제33권1호
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• pp.24-30
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• 2015

분화 노루귀(Hepatica asiatica Nakai)의 적정광도 및 분용토, 그리고 시비수준을 알아보기 위해 플라스틱 하우스안에서 실험을 수행하였다. 차광망을 이용하여 자연광을 52, 82, 90, 97%로 차광을 하고 노루귀를 재배하였다. 차광율이 낮은 처리구(52%)에서는 생존율이 65%로 낮고, 차광율이 높아질수록 생존율도 높아져 90% 이상의 차광하에서는 생존율이 80% 이상이었다. 생체중이나 엽수와 같은 생육지표에서는 처리간 유의적인 차이가 보이지 않았다. 적정 분용토 선발 실험에서는 마사토:유비상토:녹소토(60:10:30, v/v/v)와 강모래:유비상토:바크(50:20:30, v/v/v) 혼합토에서 85% 이상으로 생존율이 높았으며, 강모래:유비상토:녹소토(50:30:20, v/v/v)와 밝흙:강모래(40:60, v/v) 배합토에서는 생존율이 60% 이하로 낮았다. 엽수와 초장에서도 마사토:유비상토:녹소토(60:10:30, v/v/v)에서 가장 좋았다. 적정 시비수준을 찾기 위해 Hyponex 액비를 1,000배 또는 2,000배로 희석하여 1회/1주, 또는 1회/2주로 처리했다. 생존율이 현저하게 떨어졌던 처리구는 1,000배 희석액을 주 1회 관주처리했을 때이었고, 다른 처리구에서는 처리간 유의적인 차이가 보이지 않았다. 결론적으로 노루귀는 매우 낮은 광도에서도 살아남을 수 있는 내음성이 매우 뛰어난 식물이며, 배양토로는 배수성과 통기성이 좋은 용토를 선호하고, 상당히 폭넓은 시비수준에 적응할 수 있는 식물이라고 생각되었다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 추계학술대회
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• pp.139-140
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• 2010

This paper presents an indoor prototype for wireless digital signal transmission using Visible Light Communications (VLC) in which high power Light Emitting Diode (LED) is used. Using low cost and off-the-shelf components, the transmitter module is constructed using an AVR Atmega128 microcontroller and commercial white beam LEDs. Modulating the light intensity of the LED enables digital signals to be transmitted across the optical link. The receiver module employs a high speed PIN photodetector for optical signal detection and a recovery circuit for optical-electro signal conversion. By sending digitalized data via VLC technology, many applications can be realized in the areas of consumer advertising, traffic safety information and disaster control.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 춘계학술대회 논문집
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• pp.10-11
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• 2008

We developed the equipment palpating cell proliferation using a high brightness LED. This equipment was fabricated using a micro-controller and a high brightness LED, and designed to enable us to control light irradiation time, intensity, frequency and so on. Especially, to control the light irradiation frequency, FPGA was used, and to control the change of output value, TLC5941 was used. Control stage is divided into 30 levels by program. Consequently, the current value could be controlled by the change of level in Continue Wave(CW) and Pulse Width Modulation(PWM), and the output of a high brightness LED could be controlled stage by stage. And then, each experiment was performed to irradiation group and non-irradiation group for bone marrow cells. MIT assay method was chosen to verify the cell increase of two groups and the effect of irradiation on cell proliferation was examined by measuring 590nm transmittance of ELISA reader. As a result, the cell increase of bone marrow cells was verified in irradiation group as compared to non-irradiation group.

• Journal of Photoscience
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• 제5권2호
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• pp.53-61
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• 1998

Using a squash plant, a chilling-sensitive species, and a spinach plant, a chilling-resistant one, effects of chilling temperature on the photosynthetic machinery were studied in terms of chlorophyll fluorescence. When thylakoid membranes were isolated and subjected to incubation at different temperatures, spinach showed stable photosystem II activity at the low temperature side, in contrast to squash which showed quite severe inactivation at low temperature. When parameters of chlorophyll fluorescence were examined, chilling in darkness did not affect either Fv/Fm or photochemical and non-photochemical quenching, in both types of plants. However, chilling of squash plants under irradiance of medium intensity caused a specific decrease in Fv/Fm accompanied by a decline in energy-dependent quenching. Contrastingly, photosystem li of spinach plants were not much affected by light-chilling. When the pool size of zeaxanthin was examined after exposure to high light at different temperatures, squash plants was shown to have a much lower content of antheraxanthin + zeaxanthin, as compared to spinach plants, during low-temperature photoinhibition. These results suggest that chilling-sensitive plants have low capacity to dissipate excitation energy nonradiatively, when they are exposed to low-temperature photoinhibition, and, as a consequence, more vulnerable to photoinhibitory, damage to the photosynthetic apparatus.

• 한국작물학회지
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• 제28권4호
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• pp.497-503
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• 1983

수광율의 차이가 인삼엽내의 saponin과 유리당함량 및 Panaxatriol(PT)/Panaxadiol(PD) 비에 미치는 영향을 구명코자 수광량이 자연광의 5, 10, 20, 30%의 수광율(LTR) 하에서 자란 4년생 인삼엽에서 이들을 조사하였던 바 그 결과는 다음과 같다. 1. Ginsenoside별 함량은 PD계 사로닌에서는 -Rd가 가장 많았고, PT계 사포닌에서는 -Re, $Rg_1$, $-Rg_2$순으로 많았다. 2. Total 사포닌과 PT계 사로닌함량과 PT/PD의 비는 20% LTP까지 수광율이 많을수록 증가되다가 30% LTR에서는 약간 감소되었고, PD계 사포닌 함량은 수광율이 증가할수록 많아졌다. 3. Glucose, Fluctose 함량은 20% LTR에서 가장 많았으나 sucrose함량은 오히려 20% LTR에서 가장 적었다. 4. Total 사포닌 함량과 Glucose함량간에는 정(+)의 상관($r=0.992$^{**}$)이 인정되었다.

• 한국식품과학회지
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• 제47권6호
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• pp.785-788
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• 2015

식품 저장 중 효소적 갈변을 일으키는 타이로시네이스의 활성을 저해시킬 수 있는 LED의 파장을 구명하기 위하여 파란색, 초록색, 빨간색 LED와 형광등을 이용하여 타이로시네이스에 7일동안 조사하였다. 또한 강도에 따른 타이로시네이스의 활성을 조사하기 위하여 파란색, 초록색, 빨간색 LED를 선택하여 빛의 강도를 3단계로 구분하여 사용하였다. 파장에 따른 타이로시네이스의 활성 저해율은 형광등에서 가장 컸으며 그 다음으로 파란색 LED에서 높은 저해율을 보였다. 빨간색 LED에서는 대조구와 유사한 저해율을 보였으며 초록색 LED에서 저해율이 가장 낮았다. 상대적 빛의 강도에 따른 타이로시네이스 활성은 초록색과 빨간색 LED 조사 시 효소활성의 변화가 크지 않았고, 반면 파란색 LED에서 강도가 증가할수록 큰 저해효과를 보였다. 이러한 결과를 토대로 볼 때 여러 가지 파장의 LED 중 고강도의 파란색 LED에서 타이로시네이스에 의한 식품의 갈변을 최소화 할 수 있을 것으로 판단되며 이는 갈변 억제를 유도함으로써 과일 및 채소의 저장 중 품질을 향상시킬 수 있을 것이다.

• 대한의용생체공학회:의공학회지
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• 제30권1호
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• pp.18-22
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• 2009

Laser has been widely used in various fields of medicine. Recently, noninvasive low-level laser therapeutic medical devices have been introduced in market. However, low-level laser cannot deliver enough photon density to expect positive therapeutic results in deep tissue layer due to the light scattering property in tissue. In order to overcome the limitation, this study was aimed to develop a negative pressure applied low-level laser probe to optimize laser transmission pattern and therefore, to improve photon density in soft tissue. In order to evaluate the possibility of clinical application of the developed laser probe, ex-vivo experiments were performed with porcine skin samples and laser transmissions were quantitatively measured as a function of tissue compression. The laser probe has an air suction hole to apply negative pressure to skin, a transparent plastic body to observe variations of tissue, and a small metallic optical fiber guide to support the optical fiber when negative pressure was applied. By applying negative pressure to the laser probe, the porcine skin under the metallic optical fiber guide is compressed down and, at the same time, low-level laser is emitted into the skin. Finally, the diffusion images of laser in the sample were acquired by a CCD camera and analyzed. Compared to the peak intensity without the compression, the peak intensity of laser increased about $2{\sim}2.5$ times and FWHM decreased about $1.67{\sim}2.85$ times. In addition, the laser peak intensity was positively and linearly increased as a function of compression. In conclusion, we verified that the developed low-level laser probe can control the photon density in tissue by applying compression, and therefore, its potential for clinical applications.

• 신재생에너지
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• 제18권1호
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• pp.1-16
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• 2022

Climatic characteristics were described using the LiDAR (Light Detection and Ranging) and the met-mast on Dongbok·Bukchon region. The influences of meteorological conditions on the power performance of wind turbines were presented using the data of Supervisory Control And Data Acquisition (SCADA) and met-mast of the Dongbok·Bukchon Wind Farm (DBWF) located in Jeju Island. The stability was categorized into three parameters (Richardson number, Turbulence intensity, and Wind shear exponent). DBWF was dominant in unstable atmospheric conditions. At wind speeds of 14 m/s or more, the proportion of slightly unstable conditions accounted for more than 50%. A clear difference in the power output of the wind turbine was exhibited in the category of atmospheric stability and turbulence intensity (TI). Particularly, a more sensitive difference in power performance was showed in the rated wind speeds of the wind turbine and wind regime with high TI. When the flow had a high turbulence at low wind speeds and a low turbulence at rated wind speeds, a higher wind energy potential was produced than that in other conditions. Finally, the high-efficiency of the wind farm was confirmed in the slightly unstable atmospheric stability. However, when the unstable state become stronger, the wind farm efficiency was lower than that in the stable state.

• 공업화학
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• 제10권7호
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• pp.1035-1040
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• 1999

자외선 조사하에서 $TiO_2$를 촉매로 하여 trichloroethylene의 광분해반응을 행하였다. 여러 가지 $TiO_2$ 촉매의 활성을 비교하였고, 반응조건에 따른 광분해 활성을 조사하였다. 또한 빛의 세기에 따른 분해활성과 반응물에 첨가된 물의 영향을 조사하였다. 여러 가지 $TiO_2$ 촉매에서 P-25가 가장 높은 활성을 보였고, anatase형이 rutile형보다 높은 활성을 보였다. 또한 반응물의 유속이 느릴수록 또한 초기농도가 낮을수록 trichloroethylene의 분해 반응 활성은 증가하였고, 산화제로서 공기를 사용하는 것이 효과적이었다. 한편 반응물에 첨가된 물은 촉매의 활성을 감소시켰고, 빛의 세기가 증가할수록 분해 반응속도가 증가하였으나 태양광에 의해서는 분해율이 매우 낮았다. trichloroethylene의 농도가 낮을 경우에는 촉매의 활성저하가 거의 일어나지 않았다.

• Journal of Biosystems Engineering
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• 제35권5호
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• pp.310-315
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• 2010

The amount of salt intake of Korean people is 11.4 grams per a day, which is 2.3 times of the recommended daily salt intake by WHO - 5 grams of salt a day. The relationship between high salt consumption and increased risk of high blood pressure, observed not only in hypertensive but also in normotensive patients. High salt intake is also associated with an increased risk of heart attack, cerebral ischemia and osteoporosis. Therefore, this research is for developing a salt taste sensor to reduce sodium consumption and improve meal habits for the perception of a more bland taste of most foods. When the sensor was put into food sample, current intensity achieved with distribution cables. Current intensity was correlate with a simple equivalent of salt taste stimulus intensity. The salt taste sensor consists of salinity & temperature measuring probe, signal processing circuit and LCD display & LED warning light. When salinity is going over a set point, LCD displayer indicate salt taste on LCD panel by percent value (%), and at the same time, blue LED light change to red LED light. So we could know the grade of salt taste in soup before meals conveniently and objectively. The results show that operating range of 10 to $80^{\circ}C$ and accuracy of ${\pm}0.1%$ were achieved with an analysis time of about 2 or 3 sec. Moderate reductions in salt intake can help to avert adult diseases and lead a healthy life.