상추 친환경 재배시 수입 유박 대체제로서 하계 녹비 작물의 효과

최장용,윤여욱,강희경 한국국제농업개발학회 2022 韓國國際農業開發學會誌 Vol.34 No.1

This study was conducted to investigate the effects of summer green manure crops as an alternative for imported expeller cake fertilizer on environment-friendly lettuce production. Sunnhemp, soybean, sudangrass, and sorghum, as summer green manure crops, were evaluated under the condition of a plastic film house. In the amount of nitrogen supplied through cultivation of green manure crops, soybean plot, which supplied 187 kg ha-1, was the highest, followed by sorghum plot, 156 kg ha-1. Since all green manure plots supplied more nitrogen than that required by soil testing, it was possible to replace the nitrogen supply of expeller cake fertilizer with the amount of nitrogen produced by green manures for autumn lettuce cultivation. N nutrient balances in sunnhemp, sudangrass, soybean, and sorghum plots were 13 kg ha-1, 28 kg ha-1, 30 kg ha-1, and 38 kg ha-1, respectively. The initial yield and total yield of lettuce showed no significant difference in green manure plots compared to the expeller cake plot, but . It was thought that all green manure crops could be substituted for expeller cake fertilizer used as nitrogen fertilizer, but it would be necessary to adjust the cultivation period and reduction point according to the type of green manure in order to maintain the C/N ratio, nitrogen supply, and nitrogen balance suitable for lettuce production.

친환경 고추 재배에서 유박 비료 대체재로서 동계 풋거름 작물의 이용 가능성 평가

최장용,윤여욱,이진일,홍기흥,강영식 한국유기농업학회 2022 韓國有機農業學會誌 Vol.30 No.2

This study was conducted to find out that winter green manure crops could be efficient replacements of expeller cake fertilizers, which were mostly imported, on environment-friendly red pepper production. Four treatments were compared under the condition of plastic film house: 1) barley (B); 2) hairy vetch (HV); 3) mixtures of barley and hairy vetch (B/HV); 4) expeller cake (EC). Total nitrogen content in hariy vetch was 3.6%, which was higher than 1.5~1.8% in barley and mixtures of barley and hairy vetch. P2O5 and K2O contents were similar in all green manures. Supplying amount of nitrogen from B, HV and B/HV plot, which were 172 kg ha-1, 193 kg ha-1, and 198 kg ha-1, were higher than amount of basal nitrogen required by soil testing but were lower than that of total nitrogen, respectively. Among the green manure crops, C/N ratio of HV was the lowest at 11.8, showing a similar value to that of expeller cake, but that of B was the highest at 30.6. Total yield was no significant difference in all treatment plots although B/HV plot showed the highest yield, but initial yield in B plot with high C/N ratio was lower than that in EC plot.

비정질 셀레늄을 이용한 직접방식의 디지털 방사선 검출기와 X-ray film과의 MTF 측정을 통한 영상 질(Quality) 비교 평가에 관한 연구

崔壯墉,박지군,姜相植,文治雄,李亨媛,南尙熙 대한전자공학회 2003 電子工學會論文誌-SC (System and control) Vol.40 No.5

To evaluate the performance of the digital radiography(DR) system developed in our group, the modulation transfer function(MTF) was measured and compared with that of an analog X-ray detector, film/screen system. The DR system has an amorphous selenium(a-Se) layer vacuum-evaporated on a TFT flat panel detector. The speed class 400 film/screen(Fuji) system has been being used in the clinical field as analog X-ray detectors. Both the square wave and slit method were used to evaluate their MTF. The square method was applied to both film/screen and the DR system. The slit method, however, was applied to only DR system. The full-width half maximum resolution of film/screen was 357㎛(1.4 lp/mm at 50% spatial frequency), and the resolution of DR was limited to 200㎛(2.5 lp/mm at 50%). These results indicate the measured resolution limitations approximate to the pixel pitch, 139 ㎛, of TFT. The MTF of DR is higher than that of film/screen by the factor of 1.785. It is proved that our a-Se based DR system has potential usefulness in the clinical field. 디지털 방사선 검출기의 성능을 측정하기 위해 변조전달함수(Modulation Transfer Function)을 측정하여 기존 방사선 영상 시스템인 필름/스크린과 비교하였다. 제작된 디지털 방사선 검출기는 TFT 패널위에 진공 증착법을 통해 비정질 셀레늄이 코팅되었다. 비교 측정물이 감도 400의 필름/스크린은 아날로그 방식의 방사선 검출기로서 현재 임상에서 이용되고 있는 필름이다. Square wave & slit 측정법을 통해 두 시스템의 변조전달함수를 측정하였다. 필름/스크린의 반치폭(FWHM)은 357㎛(1.4 lp/mm at 50% spatial frequency)으로 측정되었으며, 디지털 방사선 검출 시스템은 200㎛(2.5 lp/mm at 50%)였다. 영상의 표현 성능 평가의 결과 디지털 방사선 시스템은 필름 시스템보다 높은 것으로 나타났다.

Application of chitosan and chitosan derivatives as biomaterials

최장용,남정표,나재운 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.33 No.-

Chitosan is a linear polysaccharide composed of randomly distributed b-(1-4)-linked D-glucosamineand N-acetyl-D-glucosamine. It is one of the major cationic polymers and the second most abundantpolysaccharides in nature. It is extensively used to the biomedical and the industrial fields. Specially,chitosan has been studied much in the field of gene therapy during the last decade for itsbiocompatibility and non-cytotoxicity. However, it has several problems such as solubility, lowtransfection efficiency, and low specialty on targeted disease. To solve these problems, variousstrategies have been reported to enhance them. This review briefly introduces various strategies ofchitosan carrier.

Effects of Green Manure Crops Replacing Organic Fertilizer (Yubak) on Environmental-friendly Pepper Cultivation in Greenhouse

Jang-Yong Choi(최장용),Yeo-Uk Yun(윤여욱),Moon-Tae Choi(최문태),Jin-Il Lee(이진일),In-Hee Park(박인희) 한국토양비료학회 2017 한국토양비료학회 학술발표회 초록집 Vol.2017 No.10

Survey on the Physical Properties of Upland Soil in Chungnam Province

Jang-Yong Choi(최장용),Jin-Il Lee(이진일),Yeo-Uk Yun(윤여욱),Moon-Tae Choi(최문태),Hee-Rae Cho(조희래) 한국토양비료학회 2017 한국토양비료학회 학술발표회 초록집 Vol.2017 No.10

Monitoring on the Physical Properties of Orchard Soils in Chungnam Province

Jang-Yong Choi(최장용),Su-Dong Kim(김수동),Yeo-Uk Yun(윤여욱),So-Hye Choi(최소혜),Jin-Il Lee(이진일),Jeong-Woo Son(손정우),Seung-Oh Hur(허승오) 한국토양비료학회 2022 한국토양비료학회 학술발표회 초록집 Vol.2022 No.10

Survey on the Change of Physical Properties of Upland Soil in Chungnam Province

Jang-Yong Choi(최장용),Dong-Chan Kim(김동찬),Yeo-Uk Yun(윤여욱),So-Hye Choi(최소혜),Jin-Il Lee(이진일),Jeong-Woo Son(손정우) 한국토양비료학회 2021 한국토양비료학회 학술발표회 초록집 Vol.2021 No.11

The growth and yield of crops are directly affected by soil physical properties. In most of the arable lands, the soil physical properties are expected to change with climate changes and the use of large agricultural machinery, and it should be surveyed on the arable land characteristics and the scientific management for the sustainable agriculture. In order to survey the physical properties of upland soil in Chungnam region, the soil samples for this study were collected from 45 places as points that represent the distribution rate of upland field, and investigated the agricultural condition as the kind of crops, structural condition and land-use pattern and examined the soil physical properties as soil texture, three phases of soil, and bulk density and the soil chemical properties as pH, EC and OM. Soil texture of the surveyed upland soils were mostly sandy loam and loam. The rate of cultivated crops were ordered as garlic(12plots), perilla(6), pepper(6), and were cultivated maize, sweet potato, potato, and peanut etc. The depth of A horizon was 21.1㎝ and the results of bulk density were top soil 1.33 Mg m<SUP>-3</SUP> and subsoil 1.57. The rates of three phases of the top soil were composed of solid 50.2%, liquid 25.6, and air 24.2, however the subsoil were composed of solid 59.3%, liquid 30.9, and air 9.9. The distribution rates of the particle size in top soil samples were sand 47.2%, silt 37.7, and clay 15.1, however the subsoil samples were distributed with sand 44.9%, silt 36.0, and clay 19.1. It is necessary to improve long-term soil physical properties with methods such as application of organic matter and deep tillage since the physical properties of bulk density and solid phase ratio have deteriorated compared with the data surveyed 4years ago.

비정질 셀레늄을 이용한 평판 Digital X선 검출기 개발

박지군,최장용,강상식,차병열,장기원,최준영,남상희,Park, J.K.,Choi, J.Y.,Kang, S.S.,Cha, B.Y.,Jang, G.W.,Choi, J.Y.,Nam, S.H. 대한디지털의료영상학회 2003 대한디지털영상기술학회지 Vol.6 No.1

Flat-panel detector(FPD) is the driving force for realizing the next gene ration of x-ray system. In this study, we developed amorphous selenium(a-Se) based flat-panel digital X-ray detector(DXD) for radiography. The prototype detector consists of an amorphous selenium layer and a thin-film transistor(TFT) array. Comparing to other papers1)-4), optimization of amorphous selenium and progress of evaporation were similar. The pixel pitch of fabricated detector was $139{\mu}m$, fill factor was 86%, and the size was 14"${\times}$8.5". Hand and test bar pattern images were acquired. A high modulation transfer function(MTF) factor was obtained: 58% at 3.0 lp/mm. 평판 digital x-선 검출기는 차세대 x-ray system으로 최근 연구와 개발이 활발하게 진행되고 있는 system이다. 본 연구는 환자의 피폭 및 작업 종사자의 피폭을 최소화 할 수 있고 의료장비의 디지털화에 발맞추어 PACS 등에 사용 가능한 a-Se을 이용한 직접방식의 digital x-선 검출기 구현에 관한 것이다. Prototype digital x-선 검출기는 TFT층과 a-Se층으로 이루어져 있다. Digital x-선 검출기센서 증착과 정의 최적화 수행 결과를 참고문헌1)-4)과 비교했을 때 매우 유사함을 확인하였다. 제작된 검출기의 pixel pitch는 $139{\mu}m$였고, fill factor는 86%, 전체 검출기의 검출면적은 14"${\times}$8.5"였다. Digital 영상의 해상력을 고려하기 위해 손과 test 패턴영상을 얻었고, 58%, 3.0lp/mm의 높은 MTF를 얻을 수가 있었다. 이러한 결과로 a-Se 기반의 Digital X선 검출기가 구현되었으며 본 연구결과를 토대로 향후 digital X선 검출기 개발기술의 발전과 성능향상을 가져올 것으로 기대된다.

Development of $14"{\times}8.5"$ active matrix flat-panel digital x-ray detector system and Imaging performance

박지군,최장용,강상식,이동길,석대우,남상희,Park, Ji-Koon,Choi, Jang-Yong,Kang, Sang-Sik,Lee, Dong-Gil,Seok, Dae-Woo,Nam, Sang Hee 대한방사선기술학회 2003 방사선기술과학 Vol.26 No.4

의료영상 분야에서의 디지털화가 시도되면서부터 평판형 디지털 영상검출기가 일반촬영 및 투시영상을 비롯한 다양한 영상 획득 장치에의 적용을 위해 꾸준히 연구, 개발되어져 왔다. 본 연구는 비정질 셀레늄을 이용한 디지털 방사선 검출기를 통해 획득된 영상의 평가를 통해 순수 국내 기술로 개발중인 디지털 방사선 검출기의 임상 사용여부를 확인하고, 영상평가의 주요인자인 modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) 이용하여 정량적인 값을 도출함으로써 의료영상평가에 필요한 측정 방법 및 그 기초 자료의 제공을 그 목적으로 한다. 비정질 셀레늄을 이용한 디지털 방사선 검출기는 pixel pitch가 $139\;{\mu}m$이며, 전체 active area은 $14{\times}8.5\;inch^2$, 전체 pixel의 수는 3.9백만개이다. 디지털 X-선 검출기에서 광도전체로서 비정질 셀레늄은 TFT 평판 패널 위에 진공 증착된다. 비정질 셀레늄의 두께는 $500\;{\mu}m$이다. 디지털 방사선 검출기의 성능을 평가하기 위해 민감도, 선형성, MTF, NPS, 그리고 DQE가 측정되었다. 선형성 평가에서는 뛰어난 선형성[($r^2$)=0.9693]을 보였다. 측정된 민감도는 인가전압 $10\;V/{\mu}m$에서 $4.16{\times}10^6\;ehp/pixel{\cdot}mR$이며, MTF는 2.5\;lp/mm에서 52%이다. 그리고 DQE는 1.5\;lp/mm에서 75%이다. 본 연구를 통해 영상평가 측정 기술의 기본적 토대를 마련하고, 측정된 값은 국내 기술로 개발중인 비정질 셀레늄을 이용한 직접방식의 디지털 방사선 검출기의 임상적 사용가치가 충분함을 뒷받침할 수 있는 기초 자료로서 제공될 수 있을 것으로 판단된다. Digital radiographic systems based on solid-state detectors, commonly referred to as flat-panel detectors, are gaining popularity in clinical practice. Large area, flat panel solid state detectors are being investigated for digital radiography. The purpose of this work was to evaluate the active matrix flat panel digital x-ray detectors in terms of their modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE). In this paper, development and evaluation of a selenium-based flat-panel digital x-ray detector are described. The prototype detector has a pixel pitch of $139\;{\mu}m$ and a total active imaging area of $14{\times}8.5\;inch^2$, giving a total 3.9 million pixels. This detector include a x-ray imaging layer of amorphous selenium as a photoconductor which is evaporated in vacuum state on a TFT flat panel, to make signals in proportion to incident x-ray. The film thickness was about $500\;{\mu}m$. To evaluate the imaging performance of the digital radiography(DR) system developed in our group, sensitivity, linearity, the modulation transfer function(MTF), noise power spectrum (NPS) and detective quantum efficiency(DQE) of detector was measured. The measured sensitivity was $4.16{\times}10^6\;ehp/pixel{\cdot}mR$ at the bias field of $10\;V/{\mu}m$ : The beam condition was 41.9\;KeV. Measured MTF at 2.5\;lp/mm was 52%, and the DQE at 1.5\;lp/mm was 75%. And the excellent linearity was showed where the coefficient of determination ($r^2$) is 0.9693.