• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.388-393
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• 2012

Acoustic brightness and contrast control are promising techniques for manipulating acoustic energy over selected zones of interest using loudspeaker arrays. In this paper, the fundamental theory and concept of the brightness and contrast control is reviewed. The similarity and difference of two different strategies are explained in terms of the constraint required to determine a unique solution among many possible candidates. The application examples and recent progresses of the brightness and contrast control are presented.

• 축산식품과학과 산업
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• v.5 no.2
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• pp.58-69
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• 2016

건강지향의 식육, 육제품에 대한 사회적 요구에 부응하기 위해 기능성 첨가물 대체 연구로부터 원재료인 신선육과 가공공정 중 식육 단백질의 변성을 제어하고 최적화하기 위한 연구과제로써 온도체 가공/급속동결송풍냉각/저온 세절혼합 조합 기술(처리구)에 대한 유효성이 평가되었다. 그 결과 새로 제안된 조합 공정기술은 기존의 냉도체/수침냉각/세절혼합 조합(대조구)과 비교했을 때 단백질 변성 제어를 통한 기능성 단백질 추출성의 향상으로 인해 신선육의 품질향상뿐만 아니라 가열 처리 후 단백질 겔의 수율과 조직감 모두 증진되었으며, 특히 나트륨을 저감화한 조건($2%{\rightarrow}1%$)에서도 기존의 대조구와 유사한 특성을 보여 나트륨 저감화를 위한 기술로 제안될 수 있었다.

• Korean Journal of Ecology and Environment
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• v.54 no.4
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• pp.272-279
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• 2021

A pump-type eDNA filtering system that can control voltage and hydraulic pressure respectively has been developed, and applied a filter case that can filter out without damaging the filter. The filtering performance of the developed system was evaluated by comparing the eDNA concentration with the conventional vacuum-pressured filtering method at the catchment conduit intake reservoir. The developed system was divided into a voltage control (manual pump system) method and a pressure control (automatic pump system) method, and the pressure was measured during filtering and the pressure change of each system was compared. The voltage control method started with 65 [KPa] at the beginning of the filtering, and as the filtering time elapsed, the amount of filtrate accumulated in the filter increased, so the pressure gradually increased. As a result of controlling the pressure control method to maintain a constant pressure according to the designed algorithm, there was a difference in the width of the hydraulic pressure fluctuation during the filtering process according to the feedback time of the hydraulic pressure sensor, and it was confirmed that the pressure was converged to the target pressure. The filtering performance of the developed system was confirmed by measuring the eDNA concentration and comparing the voltage control method and the hydraulic control method with the control group. The voltage control method obtained similar results to the control group, but the hydraulic control method showed lower results than the control group. It is considered that the low eDNA concentration in the hydraulic control method is due to the large pressure deviation during filtering and maintaining a constant pressure during the filtering process. Therefore, rather than maintaining a constant pressure during filtering, it was confirmed that a voltage control method in which the pressure is gradually increased as the filtrate increases with the lapse of filtering time is suitable for collecting eDNA. As a result of comparing the average concentration of eDNA in lentic zone and lotic zone as a control group, it was found to be 96.2 [ng µL^-1] and 88.4 [ng µL^-1l], respectively. The result of comparing the average concentration of eDNA by the pump method was also high in the lentic zone sample as 90.7 [ng µL^-1] and 74.8 [ng µL^-1] in the lentic zone and the lotic zone, respectively. The high eDNA concentration in the lentic zone is thought to be due to the influence of microorganisms including the remaining eDNA.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.21-21
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• 2001

일반적으로 세포는 방사능이나 항암제 등의 자극에 의해 DNA가 손상받았을 때 DNA를 합성하기 전, DNA변이를 복구하기 위해 cell cycle을 정지시키게 된다. pRB(retinoblatoma protein)는 이러한 cell cycle의 조절기작에서 중요한 역할을 담당하는 것으로 알려져 있다. G1기에서 S기로 진행하는 것을 조절하는 단백질인 pRB 은 E2F(cell cycle transcription factor)와 상호작용하여 cell cycle 진행에 필요한 전사활성을 억제, PCNA (proliferating cell nuclear antigen)의 합성을 저해한다. 또한, E2F와 결합된 pRB는 apoptosis를 제어하는 유전자를 조절하는 것으로 알려져 있다. Cell cycle에 영향을 미치는 항암제의 일종인 busulfan을 처리하면, 정소 내에 존재하는 대부분의 생식세포들은 사멸되고 spermatogonia만 남는 것으로 알려져 있다. 그러나 그 기작에 대해서는 자세히 연구된 바가 없다. 본 연구에서는 busulfan처리시 spermatogonial stem cell이 어떤 기작에 의해 손상받지 않고 유지되는지를 알아보고자 실험을 수행하였다. Busulfan을 처리한 마우스 (항암제 투여 후 5주)와 정상적인 13주령의 마우스의 정소로부터 각각 세포를 분리하였다. LSC (laser scanning cytometry)를 이용하여 처리군(busulfan treated mice)과 대조군(normal mature mice)에 대해 각각 DNA함량을 비교ㆍ분석한 결과 G0/G1(2N)에 머물러 있는 세포비율이 처리군에서 현저하게 증가했다 (79.3$\pm$5.5%:8.1$\pm$1.3%). Cell cycle의 G1/S check point인 pRB와 PCNA 발현을 Western blot과 면역조직학적인 방법(immunohisto-chemistry)을 이용하여 조사하였다 PCNA는 대조군과 비교해, 처리군에서 매우 낮은 수준으로 발현되었다. 면역염색된 정소단면을 살펴보면, 대조군에서는 모든 세정관에서 PCNA를 발현하는 세포가 높은 비율로 검출되었고, 처리군에서는 소수의 세정관에서 세포들이 낮은 수준으로 검출되었다. 반면에, pRB의 경우 PCNA와는 상반된 결과를 나타내어, 대조군에서는 거의 발현이 되지 않는 반면, 처리군에서는 대부분의 세정관내, 기저막을 따라 위치한 세포들에서 발현되었다. 이상의 결과는 busulfan에 의해 pRB의 인산화가 억제, pRB 와 결합된 E2F는 전사 활성이 억제되어, PCNA 합성을 저해하는 것으로 설명되어질 수 있다. 결론적으로, 인산화가 억제된 pRB (underphosphorylated RB protein)이 quiescent spermatogonial stem cell에서만 특이하게 발현하는 단백질이며, 이러한 pRB의 발현은 apoptosis를 제어하는 역할을 담당해 busulfan처리에 의해 손상받지 않고 남아있는 것으로 시사된다.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2008.11a
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• pp.515-516
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• 2008

MBR공정에서 막 오염을 제어하기 위하여 분리막 모듈에 원통형 관을 도입하여 각각 공기공급량과 MLSS농도, 분리막 면적에 따른 막 오염 정도를 나타내는 TMP를 분석하였다. 원통형 관을 사용하지 않은 대조군보다 원통형 관을 사용한 M$_1$과 M$_2$ 경우에 운전 종료 시점이 연장된 것을 확인할 수 있었고 공기공급량과 MLSS농도, 분리막 면적의 변화에 따른 TMP의 변화가 생기는 것을 확인할 수 있었다.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.1
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• pp.75-84
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• 2015

This study was conducted to investigate the effects of high temperature and drought on growth performance, photosynthetic parameters and photosynthetic pigment contents of Liriodendron tulipifera L. seedlings. The seedlings were grown in controlled-environment growth chambers with combinations of four temperature ($-3^{\circ}C$, $0^{\circ}C$, $+3^{\circ}C$, $+6^{\circ}C$; based on the monthly average for 30 years in Korea) and two water status (control, drought). Temperature rise increased growth, total dry weight and leaf area in all water status. Also photosynthetic rate, dark respiration, stomatal conductance and transpiration rate increased with increasing temperature. In contrast, growth and photosynthetic parameters of L. tulipifera seedlings were lower in $-3^{\circ}C$ than $0^{\circ}C$. But temperature rise decreased water use efficiency in all water status. Temperature rise increased photosynthetic pigment contents of leaf. Also chlorophyll a/b ratio increased with increasing temperature. In conclusion, the elevated temperature lead to causes growth increase through the increase of energy production by higher photosynthetic rate during a growth period of L. tulipifera seedlings.

• Ecology and Resilient Infrastructure
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• v.4 no.3
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• pp.130-141
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• 2017

We evaluated the field application feasibility that biologically derived substances (Naphthoquinone derivate: NQ 2-0) can be used for the eco-friendly mitigation of natural harmful cyanobacterial blooms in freshwater. We conducted a 30 ton scale mesocosm experiment to investigate the effects of NQ 2-0 on biotic and abiotic factors in water collected from Gi-heung reservoir. In the mesocosm experiments, the abundance of Microcystis sp. was continuously increased in the control. However, the Microcystis sp. cell density was sharply decreased on the $10^{th}$ day. In the treatment, NQ 2-0 showed the strong and selective algicidal activity toward the target cyanobacteria (Microcystis sp.). Accordingly, the algicidal activity of NQ 2-0 compound increased gradually until $10^{th}$, $15^{th}$ days and algal biomass was decreased to 99.4 and 100 %, respectively. NQ 2-0 compound was not only selective algicidal activity but also the growth of other phytoplankton and increased the Shannon-Wiener diversity index of phytoplankton. In the mesocosm experiments, the dynamics of biotic (bacteria, heterotrophic nanoflagellate, ciliates, zooplankton) and abiotic (water temperature, dissolved oxygen, pH, conductivity, nutrients) factors remained unaffected. These results suggest that NQ 2-0 could be a selective and ecologically safe algicide to mitigate harmful cyanobacterial blooms. In addition, it is believed that NQ 2-0 will play a major role in forming a healthy aquatic ecosystem by facilitating habitat and food supply of aquatic organisms.

• Journal of Bio-Environment Control
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• v.29 no.3
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• pp.265-276
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• 2020

This study was conducted to provide a basis for raising farm income by increasing the yield and extending the cultivation period by creating an environment where crops can be cultivated normally during high temperatures in summer. The maximum cooling load of the multi-span greenhouse with a floor area of 504 ㎡ was found to be 462,609 W, and keeping the greenhouse under 32℃ without shading the greenhouse at a high temperature, it was necessary to fog spray 471.6 L of water per hour. The automatic fog cooling control device was developed to effectively control the fog device, the flow fan, and the light blocking device constituting the fog cooling system. The fog cooling system showed that the temperature of the greenhouse could be lowered by 6℃ than the outside temperature. The relative humidity of the fog-cooled greenhouse was 40-80% during the day, about 20% higher than that of the control greenhouse, and this increase in relative humidity contributed to the growth of cucumbers. The relative humidity of the fog cooling greenhouse during the day was 40-80%, which was about 20% higher than that of the control greenhouse, and this increase in relative humidity contributed to the growth of cucumbers. The yield of cucumbers in the fog-cooled greenhouse was 1.8 times higher in the single-span greenhouse and two times higher in the multi-span greenhouse compared to the control greenhouse.

• Ecology and Resilient Infrastructure
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• v.2 no.3
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• pp.224-236
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• 2015

We conducted the algicidal activity screening tests using 10 L microcosm to investigate the possibility of the field application of naphthoquinone derivative Nq 4-6 compound as an algicide. We determined its application range to assess its algicidal effects on the phytoplankton and to evaluate the response of the planktonic community and the water environment to this chemical. From results of the microcosm experiments, Nq 4-6 compound showed high algicidal activity on the centric diatoms such as Stephanodiscus hantzschii and Cyclotella meneghiniana, but it had no effect on other phytoplankton. The abundance of S. hantzschii continuously increased in the control, but its cell density decreased 1 day after the Nq 4-6 treatment. In particular, Nq 4-6 showed algicidal activity of 94.4% against S. hantzschii 7 days after the treatment. The dominance index of phytoplankton community was lower in the treatment than in the control. The diversity index, richness index and evenness index of phytoplankton community was higher in the treatment. Environmental factors and biological factors did not show specific changes after the Nq 4-6 compound treatment. Therefore, the results of this study demonstrates that Nq 4-6 is an effective agent for the control of S. hantzschii blooms, and that the microcosm tests play a crucial role when assessing field application.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.173-173
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• 2017

드론의 시장규모가 커짐에 따라 초창기 군사 목적에서 현재 민간부문으로 확대되고 있다. 현재 드론은 실외에서 사용될 목적으로 제작된 것이 많으나 실내에서도 드론의 활용 여부가 증가할 것으로 예상된다. 본 연구에서는 실외에서만 사용 가능한 GPS를 대신하여 영상 촬영으로 획득한 이미지를 CNN으로 학습을 시켜 자율고도제어비행을 하도록 한다. 첫 번째로 수동 조작하는 드론에 IMU센서를 부착하여 획득한 고도 데이터를 표로 제시함으로써 GPS를 사용하지 않는 드론의 실내주행에서 일정한 고도 유지는 다소 무리가 있음을 보여준다. 두 번째로 드론의 수동 조작은 일정하지 않은 고도 때문에 CNN의 학습할 영상 획득이 어렵다. 일정한 고도의 영상 획득을 위한 실험용 높이 조절 Base를 제작하여 고도별 영상을 획득한다. 획득한 영상을 통해 얻은 이미지를 CNN 학습을 시킨 후, 학습에 사용되지 않은 이미지를 사용하여 고도 판별을 확인한다. 대조군으로 실내장소를 바꾸어 미리 학습된 CNN으로 고도 판별을 확인한다. 학습에 사용된 이미지의 환경(생명공학관)과 대조군(제 2 공학관)이 촬영된 장소의 환경요소의 차이로 오차가 발생한다. 오차는 실내 장소의 총 높이의 차이 및 서로 상이한 천장 구조물에 따른 것으로 사료되며 Data crop을 통해 획득한 이미지의 천정 부분을 제거하여 노이즈를 줄여 고도 판별의 정확도를 높일 수 있을 것으로 예상한다. 세 번째, CNN으로 학습을 통해 Model을 도출하여 자율 고도 제어 프로세스를 제시한다. 그리고 해당 프로세스를 이용한 자율고도제어 주행과 수동조작을 통한 주행에서의 Z축 가속도 데이터의 표준편차를 비교하여 본 연구의 실효성을 보여준다