자율 주행 트랙터를 위한 포장형상 및 경운작업특성 인식시스템 개발

서일환(Il-Hwan Seo),서동현(Dong-Hyun Seo),김만수(Man-Soo Kim),정선옥(Sun-Ok Chung),김기대(Ki-Dae Kim) 충남대학교 농업과학연구소 2011 농업과학연구 Vol.38 No.2

Precise traveling and tillage operation using an autonomous tractor is difficult with the data from the Geographic Information System(GIS) because it does not include the data of the width and inclination of the field to work. The minimum turing radius of the tractor could be different from the value presented by the tractor maker due to the moisture content of the field soil or operators’ skill. Two programs were developed to process data obtained with the tillage path measuring system: one for recognizing coordinates of the 4 field corners, and the other for recognizing the minimum turning radius of the tractor.

가역적 리간드 결합에 의하여 유발되는 DNA 의 응축 - 풀림 구조변이 : 2. DNA Conformation Probes 로서의 Anionic Potential Reporter 분자의 구조 연구 Anionic Potential Reporter Molecules as Probes of DNA Conformation

서일환,이천배,고동성,서정인 생화학분자생물학회 1992 BMB Reports Vol.14 No.2

The hydrolytic susceptibility of calf thymus DNA to DNase 1 was enhanced by such anionic Quinolone antibiotics as nalidixic acid and oxolinic acid in the presence of spermine, as well as by such cat-ionic intercalative agents as ethidium bromide, profavine, and actidine orange. In contrast with the susceptibility of the native DNA, the susceptibility of the denatured DNA was not affected by the quinolone antibiotics, not either by the cationic dyes. Even the native DNA, however, was not influenced by the anionic antibiotics in its susceptibility to DNase 1 if spermine was omitted. The data here may lead to a tentative contusion that the quinolone antibiotics may form intercalative complexes with spermine, and that thereby the quinolone antibiotics can be used as probes of DNA conformation, whereas the anionic antibiotics alone without spermine may not have the intercalation activity, as supported by the MO data.

전산유체역학을 이용한 미세조류 배양용 광생물반응기의 정량적 평가 방안

서일환 ( I. -h. Seo ),이인복 ( I. -b Lee ) 한국농공학회 2010 한국농공학회 학술대회초록집 Vol.2010 No.-

Renewable energy has been interested due to the fossil energy depletion and the carbon dioxide reduction. Bio-diesel is one of the most desirable renewable energy because it can alternate the diesel from petroleum directly. However, the bio-diesel using soybean, canola, corn crop, etc. can be confronted with food consumption. Because a microalgae has higher oil lipid contents and rapider growth rates comparing to the earlier raw materials, it can be a good source for bio-diesel production. Because pond production system is limited in distinguishable four seasons and insufficient land availability in Korea, photo-bioreactor (PBR) is a good alternative way to cultivate microalgae by artificially controlling the internal environments such as light, nutrients, temperature, carbon dioxide, and so on. Despite the availability of these PBRs, only few of them can be practically used for mass production. In this study, computational fluid dynamics (CFD) was used to find an optimum bubble-column PBRs for mass cultivation of the microalgae. Multi-phase models including bubble movement, meshes & time step independent tests were used to design the three dimensional CFD model. The model was validated comparing to the field experiments including particle image velocimetry (PIV) tests. Using the validated CFD model, various types of PBRs were compared quantitatively with consideration of a microalgae growth model adaptable for the CFD model. An evaluation method for mixing efficiency in the PBRs was developed by tracing the movement of each particle in the PBRs connected with the growth model according to the light intensity. The results showed that the mixing efficiency and uniformity in the 20 L of plate type PBRs can be enhanced by 73% and 36% respectively when the baffle was installed in order to guide the fluid flow using bubble injection.

돈사의 시설 및 환기구조에 따른 돼지 호흡기성 질병 발생 가능성

서일환 ( Seo I. -h. ),이인복 ( Lee I. -b. ),황현섭 ( Hwang H. -s. ),홍세운 ( Hong S. -w. ),( Jessie P. Bitog ),유재인 ( Yoo J. I. ),권경석 ( Kwon K. -s. ),김용희 ( Kim Y. -h. ) 한국농공학회 2008 한국농공학회 학술대회초록집 Vol.2008 No.-

The typical diseases for pigs in Korea are Porcine epidemic diarrhea (PED), Porcine reproductive and respiratory syndrome (PRRS), Post weaning multi-systemic wasting syndrome (PMWS), and Porcine respiratory disease complex (PRDC). The main factor for the occurrence of these diseases specially the respiratory diseases is the environmental condition particularly ventilation inside the pig house. Considering that Korea has 4 distinct season, the environmental condition in the pig house changes every season. The purpose of this study was to find the relationship between the configuration of the structure and ventilation system of pig houses and the occurrence of pig respiratory disease. The effect of internal airflow distribution to internal disease dispersion in pig house was analyzed. Several field experiments were conducted at several pig farms to understand the environmental control in relation to disease occurrence. To overcome the difficulties of conducting field experiments and obtain internal airflow visualization quantitatively and qualitatively, computational fluid dynamic (CFD). The accuracy of the simulations was preliminarily examined and improvements were made in the model based form the seasonally collected farm data.

농업지역 대기질 모니터링을 위한 대상지역 및 측정소 설계

서일환 ( Il-hwan Seo ),오병욱 ( Byung-wook Oh ) 한국농공학회 2022 한국농공학회 학술대회초록집 Vol.2022 No.-

온실가스와 탄소배출 저감 및 미세먼지 등 농업에서의 대기질에 대한 관심이 증대되고 있으며, 특히 암모니아는 국내 배출량의 약 80% 정도가 농업부문에서 발생되고 있다. 암모니아는 2차생성 미세먼지의 전구물질로서 미세먼지 및 암모니아에 대한 적정한 현장에서의 관리목표를 수립하고, 사업에 대한 영향을 검토하기 위하여 기본적인 농촌지역의 농업대기질에 대한 기초데이터를 확보하는 것이 중요하다. 특히 농업은 타 산업과는 다르게 작목에 따라서 비료를 시비하는 특정시기에 암모니아의 농도가 증가하거나, 농작업을 위한 경운, 수확 시 미세먼지의 농도가 증가하는 등 작업 및 영농방식에 따라 시공간적인 배출특성의 연중변동이 심하기 때문에 장기적인 연속모니터링을 수행하여야 한다. 이에 본 연구에서는 농업대기질 측정을 위하여 미세먼지(PM-10, PM-2.5), NH3, NOx, SOx를 실시간으로 모니터링하기 위하여, 대표적인 작목과 대상지역을 지역별 분배와 작목별 분배를 바탕으로 배분하여 적정한 설치 지역 및 측정소 설치위치를 결정하였다. 또한 농업 대기질에 대한 연속적인 데이터의 확보를 위하여 측정 프로토콜을 정립하였으며, 공인된 모니터링 장비를 바탕으로 암모니아, 미세먼지 등 대기질을 측정하기 위한 측정소를 설계하였다. 측정장비는 데이터 품질향상을 위하여 주기적으로 검정 및 센서교체를 수행하며, 현장조사를 기반으로 영농활동과 함께 대기질에 영향을 미칠 수 있는 환경적 특이사항을 기록하여 장기적으로 기초데이터를 수집할 수 있는 기반을 마련하였다. 지속적으로 수집되는 농업대기질 빅데이터는 시기별, 작목별, 영농활동별 배출특성을 연구하기 위하여 사용될 수 있으며, 향후 농업대기질 측정망 구축을 위한 가이드라인을 마련하기 위하여 활용될 수 있다.

응집효율 향상을 위한 미세조류 배양용 Raceway Pond 설계

서일환 ( Il-hwan Seo ) 한국농공학회 2016 한국농공학회 학술대회초록집 Vol.2016 No.-

미세조류는 작물보다 빠른 성장력을 가지고 있어, 바이오디젤 생산을 위한 차세대원료이자 가축분뇨에서 발생하는 영양물질을 효율적으로 제거하는데 시스템 개발에 활용될 수 있다. 에너지 생산시설 및 생물학적 분해에 의한 수처리시설에 활용하기 위해서는 배양시설의 대형화가 필요하며, 기존의 현장실험을 통하여 보기 어려운 배양액의 유동해석을 바탕으로 생산, 응집, 혼합 등의 생물학적인 배양환경 분석이 필요하다. 특히 미세조류의 성장을 위하여 광, 이산화탄소 농도, 온도, 영양물질 등이 안정적으로 균일하게 제공되어야 한다. 본 연구에서는 10 톤 급의 미세조류 배양용 Raceway pond에서 생산은 물론 수확을 위한 응집효율 향상을 위한 시스템의 문제점을 고찰하고 해결방안 및 최적화된 모델을 설계하고자 한다. 이를 위하여 전산유체역학 (CFD, Computational fluid dynamics)을 이용하여 Raceway pond 모델링을 수행하였으며, VOF (volume of fluid) 다상모델 등을 통하여 내부 배양환경을 모의하였다. 현재까지 응집효율 향상을 위한 범용적인 모델이 개발 및 적용되어 있지 않기 때문에 현장에서 분석 및 조절이 가능한 난류강도와 이산화탄소 주입량에 따른 pH 농도 등을 바탕으로 응집을 조율할 수 있다.

原點選擇에 따른 構造因子의 位相變化 : Triclinic, Monoclinic, Orthorhombic System에서 Primitive이면서 Centrosymmetric인 Space Groups에만 適用 Only for Primitive and Centrosymmetric Space Groups of Triclinic, Monoclinic and Orthorhombic Systems

徐日煥,李珍昊,郭相姬,崔成山 충남대학교 기초과학연구소 1995 忠南科學硏究誌 Vol.22 No.2

Triclinic, monoclinic, orthorhombic systems에서 primitive이면서 centrosymmetric space group이면 8가지 對稱中心點中 任意의 한 點을 原點으로 指定하기 爲하여 3個의 structure factor에게 任意의 phase를 割當할 수 있음을 보였다. 이들 phase들은 direct method에서 structure factor의 phase를 決定해가는 basic set이 될 수 있다. In any primitive and centrosymmetric space group in the triclinic, monoclinic, or orthorhombic systems, arbitrary signs can be allocated to three reflections in order to specify the origin at one of the eight centers of symmetry. These signs form a basic set, from which more and more signed reflections emerge in the process of direct method.

粉末法을 爲한 多重度 因子

徐日煥,秋錦洪,李珍昊,林星秀,柳保盈,朴晶蘭,金憲俊,成百石,李正秀,金文執 충남대학교 자연과학연구소 1993 忠南科學硏究誌 Vol.20 No.1

The multiplicity factor, which may be defined as the number of different planes in a form having identical interplanar spacing and identical intensity, is tabulated here for eleven Laue groups on the basis of their symmetries.

Out of Sequence Measurement 환경에서의 MPDA 성능 분석

서일환,임영택,송택렬 대한전기학회 2006 전기학회논문지 D Vol.55 No.9(D)

- In a multi-sensor multi-target tracking systems, the local sensors have the role of tracking the target and transferring the measurements to the fusion center. The measurements from the same target can arrive out of sequence called the out-of-sequence measurements(OOSMs). Out-of-sequence measurements can arise at the fusion center due to communication delay and varying preprocessing time for different sensor platforms. In general, the track fusion occurs to enhance the tracking performance of the sensors using the measurements from the sensors at the fusion center. The target informations can arrive at the fusion center with the clutter informations in cluttered environment. In this paper, the OOSM update step with MPDA(Most Probable Data Association) is introduced and tested in several cases with the various clutter density through the Monte Carlo simulation. The performance of the MPDA with OOSM update step is compared with the existing NN, PDA, and PDA-AI for the air target tracking in cluttered and out-of-sequence measurement environment. Simulation results show that MPDA with the OOSM has compatible root mean square errors with out-of-sequence PDA-AI filter and the MPDA is sufficient to be used in out-of-sequence environment.

Multi-lag Out of Sequence Measurement 환경에서의 IMM-MPDA 필터 성능 분석

徐日煥(Il-Hwan Seo),宋澤烈(Taek-Lyul Song) 대한전기학회 2007 전기학회논문지 Vol.56 No.8

In a multi-sensor target tracking systems, the local sensors have the role of tracking the target and transferring the measurements to the fusion center. The measurements from the same target can arrive out of sequence called, the out-of-sequence measurements(OOSMs). The OOSM can arise in a form of single-lag or multi-lag throughout the transfer at the fusion center. The recursive retrodiction step was proposed to update the current state estimates with the multi-lag OOSM from the several previous papers. The real world has the possible situations that the maneuvering target informations can arrive at the fusion center with the random clutter in the possible OOSMs. In this paper, we incorporate the IMM-MPDA(Interacting Multiple Model - Most Probable Data Association) into the multi-lag OOSM update. The performance of the IMM-MPDA filter with multi-lag OOSM update is analyzed for the various clutter densities, OOSM lag numbers, and target maneuvering indexes. Simulation results show that IMM-MPDA is sufficient to be used in out of sequence environment and it is necessary to correct the current state estimates with OOSM except a very old OOSM.