가시광선-근적외선 반사스펙트럼을 이용한 쇠고기의 신선도 평가

최창현,김종훈,김용주,Choi, Chang-Hyun,Kim, Jong-Hun,Kim, Yong-Joo 한국축산식품학회 2011 한국축산식품학회지 Vol.31 No.1

본 연구에서는 유통현장에서 실시간으로 쇠고기 신선도를 측정하기 위해 가시광선-근적외선 반사 스펙트럼을 이용하여 쇠고기 신선도에 영향을 미치는 인자와 설정된 저장기간에 대하여 예측 모델을 개발하고 검증하였다. 쇠고기 시료는 총 216개를 사용하였으며 0-14일의 기간 동안 2일 간격으로 가시광선-근적외선 반사 스펙트럼을 측정한 후, 쇠고기의 신선도에 영향을 미치는 인자인 총균수, pH, VBN, TMA, TBA값을 공인된 방법을 이용하여 측정하였다. 예측모델은 다중회귀분석 방법과 최적 변수 선택이 가능한 stepwise 방법을 이용하여 개발하였으며, 예측모델의 선정은 결정계수, 오차, RPD를 이용하였다. 예측모델의 검증은 미지의 시료를 이용하였으며 그 결과 결정계수, 오차, RPD는 총균수에서 각각 0.74, 0.64, 2.75 Log CFU/$cm^2$, VBN은 각각 0.73, 1.45, 2.00 mg%, TMA는 각각 0.70, 0.19, 2.58 mg%, TBA값은 각각 0.73, 0.13, 2.77 mg MA/kg로 비교적 안정된 예측성능을 보여 주었다. 저장기간에 따른 예측모델의 검증결과는 결정계수, 오차, RPD가 각각 0.77, 1.94일, 2.53으로 실험 시 저장기간이 2일 간격인 점을 고려할 때, 비교적 높은 정밀도를 보이고 있음을 알 수 있다. pH의 예측성능은 결정계수, 오차, RPD가 각각 0.43, 0.10, 1.10로 다른 신선도 인자에 비해 낮은 결과를 보여 주었다. 본 연구에서는 가시광선-근적외선 분광분석법을 이용하여 쇠고기 신선도의 비파괴 평가에 대한 가능성을 제시하였으나 유통현장에서 적용을 위해서는 보다 많은 시료의 확보를 통한 예측모델의 신뢰성 향상과 stepwise방법으로 선정된 파장 영역을 기본으로 하는 부분최소자승법, 인공지능 등의 다양한 알고리즘의 적용을 통한 성능개선이 필요할 것으로 판단된다. The objective of this study was to develop models to predict freshness factors (total viable counts (TVC), pH, volatile basic nitrogen (VBN), trimethylamine (TMA), and thiobarbituric acid (TBA) values) and the storage period in beef using a visible and near-infrared (NIR) spectroscopic technique. A total of 216 beef spectra were collected during the storage period from 0 to 14 d at a $10^{\circ}C$ storage. A spectrophotometer was used to measure reflectance spectra from beef samples, and beef freshness spectra were divided into a calibration set and a validation set. Multi-linear regression (MLR) models using the stepwise method were developed to predict the factors. The MLR results showed that beef freshness had a good correlation between the predicted and measured factors using the selected wavelength. The correlation of determination ($r^2$), standard error of prediction (SEP), and ratio of standard deviation to SEP (RPD) of the prediction set for TVC was 0.74, 0.64, and 2.75 Log CFU/$cm^2$, respectively. The $r^2$, SEP, and RPD values for pH were 0.43, 0.10, and 1.10; those for VBN were 0.73, 1.45, and 2.00 mg%; those for TMA were 0.70, 0.19, and 2.58 mg%; those for TBA values were 0.73, 0.13, and 2.77 mg MA/kg; and those for storage period were 0.77, 1.94, and 2.53 d, respectively. The results indicate that visible and NIR spectroscopy can predict beef freshness during storage.

콤바인 예취부 고장진단을 위한 예취 칼날부의 진단 시스템 개발(I) - 진동 및 부하 신호 분석 -

최창현,김용주,김종혁,문정환,Choi, Chang-Hyun,Kim, Yong-Joo,Kim, Jong-Hyuck,Mun, Joung-Hwan 한국농업기계학회 2007 바이오시스템공학 Vol.32 No.3

The purpose of this study is to develop a measurement system of cutter conditions for combine header diagnosis during rice harvesting. A load cell was installed at the locker-arm to measure load fluctuation and an acceleration senor was used to monitor vibration signal of cutter bar. The data were collected from a paddy field during harvesting. The tests were conducted with a normal cutter, a loosened cutter, a broken cutter, and a worn-out connecter pin at the field. The vibration signals converted by FFT (Fast Fourier Transformation), filtered, and normalized. The load data and peak values of vibration signals in four different frequency ranges were used to determine the cutting operation and the cutter conditions of combine. The multiple comparison tests showed that the load data and peak values of vibration signals were important to monitor the cutting operation and cutter conditions of combine header.

BIM기반 MEP공사 시공용 도면 작성 자동화 프로세스 제안

최창현,권대용,조상호,김주형,Choi, Chang-Hyun,Kwon, Dae-Yong,Cho, Sang-Ho,Kim, Ju-Hyung 한국BIM학회 2020 KIBIM Magazine Vol.10 No.4

Shop drawing tasks conducted after finishing coordinated or engineering design have great influences on the quality and cost of a project. However, despite the development of commercial BIM applications, shop drawings have mainly produced manually in certain engineering fields. Incorrect shop drawings with human errors have occurred various problems such as cost overrun, time delay and reworks. An automated shop drawing publishing from BIM is expected to resolve these problems. Despite attempts for automate shop drawing production, the field of mechanical, electrical and plumbing (MEP) is yet regarded challenging due to complexity of components and connection. In this research, we develop a process for automated producing 3D MEP shop drawings in BIM environment as following steps: to analyze conventional MEP shop drawing process, to identify detailed process that can be automated, to classify existing MEP objects and assign codes usable in BIM, and to develop an application. The validation of automated process is conducted against 10 clean room projects in which MEP is more complex and its cost is higher than other projects in terms of productivity and workers' satisfaction. Results show that the number of manpower for shop drawing is reduced by 30%, and the working time is shortened by 31%. Personal opinions of involved practitioners is interpreted as positive as the average rate of agrement on practicability, easy-to-use and necessary retouch tasks is around 66%.

맥류 연구의 과거, 현재, 그리고 미래

김경민(Kyeong-Min Kim),강천식(Chon-Sik Kang),김양길(Yang-Kil Kim),김경훈(Kyeong-Hoon Kim),박종호(Jong-Ho Park),윤영미(Young-Mi Yoon),박형호(Hyoung-Ho Park),정한용(Han-Yong Jeong),최창현(Chang-Hyun Choi),박진희(Jinhee Park),김영진(You 한국육종학회 2020 한국육종학회지 Vol.52 No.S

Barley and wheat are a major food crop of humans, along with rice, soybean and corn. A systematic breeding program for Korean barley began in 1906 with selection and introduction breeding. In 1908, landrace barley was collected, and breeding focused on selection and introduction for high yielding varieties until the 1970s. In the 1980s and 1990s, breeding was carried out for diversity; thereafter, we aimed to improve quality, productivity and lodging tolerance that can be applied to the paddy field in Korea. Since 2010, the major result of breeding was shortening cultivation to approximately 6–12 days, making a double cropping system possible in the paddy field in Korea. Yield has increased by 1.2 times from 438 kg/10 a in the 1960s to 536 kg/10 a in the 2010s, and farm yield has increased by 1.7 times. In addition, as cultivation safety has been enhanced, the varieties have also improved, such as the covered barley used in making tea and other processing products. In case of wheat, up to now forty cultivars have been developed in Korea. In the early stage, we developed a domestic wheat variety that was early maturing and high yielding. As a result, the maturation time of wheat planted in the 1970s to 2010 was shortened (from 13 to 30 days), while productivity increased by 30% from 408 kg/10 a in the 1970s to 532 kg/10 a in 2010. In recent years, there have been remarkable efforts for a more stable production by focusing on increasing disaster and pest resistance due to climate change. In addition, a wheat variety discrimination marker was developed using a variety-specific marker, and selection was made using a trait-specific marker at the early stage of breeding to enhance breeding efficiency. In the 2000s, winter cereals for forage have been promoted to expand forage production and to replace imported feed grains. Therefore, winter cereal that is useful for feed, such as rye, oat, and triticale, have had various varieties and safe production techniques developed. Currently, our research goal for winter cereals for feed is to develop a double-cropping adaptation and abiotic stress tolerance cultivar, and safe production in paddy field. Hence, aggressive action is needed to support the strategic survival of the Korean wheat and barley industry. Barley is a health food that requires a multifaceted effort to improve breeding efficiency, develop varieties that contain large amounts of functional components and are more resistant to stronger biotic and abiotic stresses in response to climate change. It is necessary to recognize the role of wheat and barley as the second main crop after rice, and to improve the self-sufficiency rate of these crops for the health and food industry crisis of Korea.

군수품의 개발 품질보증 적용사례 연구

최창현 ( Chang-hyun Choi ) 한국품질경영학회 2018 한국품질경영학회 학술대회 Vol.2018 No.-

Purpose 신뢰성 있는 구수품의 품질을 확보하기 위해서는 개발단계에서 설계품질을 확보하는 것이 중요하다. 개발단계 품질보증체계를 구축 또는 재정비하여 개발, 양산 및 운용단계의 균형있는 전순기 품질보증 체계를 갖추어야 하며 이를 위하여 개발단계 품질보증체계 구축을 위한 적용 사례소개와 발전방안을 제시하고자 한다. Methods 개발단계 설계품질의 확보를 위하여 ‘02년에 CMM의 SQA 품질보증 요구사항에 적합한 개발 품질보증체계를 구축하여 개발단계 품질보증 활동을 시작하였으며 ’09년 CMMI Levl5에 적합한 개발 관련 프로세스를 구축&인증을 기반으로 하여 소프트웨어 신뢰성시험(‘09년), 형상확인(’10년), MRA 프로세스 구축(‘12년), 개발 Control Gate 구축(’13년), 실패사례 피드백 체계 구축(‘13년), 초기고장 배제시험 전체계 개발과제 적용(’14년) 및 TMMi 프로세스 구축/인증(‘15년) 등 지속적으로 개발 품질보증 활동을 확대 및 강화하고 있다. Results 군수품의 개발단계 품질보증 구축&적용사례를 제시함으로써 개발단계 품질보증체계 구축 또는 강화하고자 하는 업체에 도움이 될것임. [지표상으로는 초도기술변경율 83% 감소, 초도시장 불량률 82% 향상, 고객시험불량률 Zero화, 제조성숙도 평가(MRA)는 달성율이 타사평균 30.4% 대비 한화시스템(HSC)은 81.8%로 월등히 높음] ‘14년: 국방품질연구회 총회 기념세미나 “개발단계 품질보증 발전방안_우수사례” 발표 ‘15년: 방사청장 연구개발장려금 품질분야 방산업체 최초 수상 “고품질 확보를 위한 개발 Control Gate 체계 구축” ‘16년: 방사청장 주관 국방 품질관리 강화를 위한 토론회 “개발단계 품질보증 추진사례 및 발전방안” 우수사례 발표 Conclusion: 신뢰성 있는 군수품의 품질을 확보하기 위해서는 예방품질 이론 1:10:100의 법칙처럼 예방활동에 역점을 두고 “처음부터 올바르게” 하기 위해서는 개발단계에서 품질을 확보 할 수 있는 품질보증체계를 구축하여야 하며 무엇보다도 중요한 것은 구축된 시스템이 잘 실행 될 수 있도록 제도화 하여야 하며 개발, 양산 및 운용단계의 균형있는 전순기 품질보증체계를 갖추어야 한다. 이를 위한 몇가지 발전방안을 제언하고자한다.

근적외 분광법을 응용한 휴대용 벌꿀 품질 평가 장치 개발

최창현 ( Chang Hyun Choi ),김종훈 ( Jong Hun Kim ),권기현 ( Ki Hyun Kwon ),김용주 ( Yong Joo Kim ) 한국식품저장유통학회(구 한국농산물저장유통학회) 2011 한국식품저장유통학회지 Vol.18 No.2

This study was conducted to develop a portable quality evaluation system of bee-honey by near infrared spectroscopic technique. Two kinds of bee-honeys from acacia and polyflower sources were tested in this study. The system consists of power supply, tungsten-halogen lamp, detector, and optical fiber probe. Performance of the system was analyzed by comparing the prediction accuracy of the laboratory spectrophotometer. Total of 346 spectra was divided into a calibration set and a prediction set. The PLS (Partial Least Squares) models were developed to predict the quality parameters of bee-honeys. Reflectance spectra, moisture contents, ash, invert sugar, sucrose, F/G ratio, HMF (hydroxy methyl furfural), and C12/C13 ratio of honeys were measured. The PLS models of the laboratory spectrophotometer showed good relationships between predicted and measured quality parameters of honeys in the wavelength range of 1,100~2,200 nm. The PLS analysis of the portable quality evaluation system showed good relationships between predicted and measured quality parameters of honeys in the wavelength range of 1,100~1,300 nm and 1,400~1,700 nm. The results showed the feasibility of the portable quality evaluation system to determine the quality parameters of bee-honey in the field during harvesting.

논문 : 정보처리 및 복합기술 ; 콤바인 예취부 고장진단을 위한 예취 칼날부의 진단 시스템 개발(1) -진동 및 부하 신호 분석-

최창현 ( Chang Hyun Choi ),김용주 ( Yong Joo Kim ),김종혁 ( Jong Hyuck Kim ),문정환 ( Joung Hwan Mun ) 한국농업기계학회 2007 바이오시스템공학 Vol.32 No.3

이송 사과의 내부 결함 검출을 위한 투과 스펙트럼의 분광특성 분석

최창현 ( Chang Hyun Choi ),장현준 ( Hyeon Jun Jang ),홍성호 ( Sung Ho Hong ),주재옥 ( Jae Ok Joo ),이대현 ( Dae Hyun Lee ) 한국농업기계학회 2015 한국농업기계학회 학술발표논문집 Vol.20 No.2

각막 창상후 상피 세포 치유속도의 비교관찰

최창현(Chang Hyun Choi),정장현(Jang Hyun Chung) 대한안과학회 1993 대한안과학회지 Vol.34 No.10

정신장애인 ‘당사자’ 운동의 가능성: 정신장애인 운동 내 당사자성 논란과 정신장애차별주의적 보조금 지원 정책의 문제점

최창현 ( Choi Chang-hyun ) 한국문화인류학회 2022 韓國文化人類學 Vol.55 No.3

This study dealt with the conflict in an organization that tried to resolve negative perceptions of the mentally challenged people by hosting an event called Mad Pride Seoul; it was among the various attempts to form a mentally challenged ‘led’ movement that began in Korea in the 2010s. In this context, I carried out this study to reveal the factors affecting the survival of the social movement. In my role as researcher, I entered an organization that had prepared the ‘Mad Pride Seoul’ festival and prepared for the festival with them. The organization that I studied exemplifies the mentally challenged-led movement, because the ‘first-personness’ or ‘Dang-sa-ja-sung’ question is critical, because of the problem of determining who can be the subjects of the activism. It is important to note that ‘first-person’ or ‘Dang-sa-ja (Tōjisha)’ is a being in the process of ‘becoming’ through ritualization, and is not made by forcing that being to become itself. However, the people in the organization wanted to stage a recovery of everyday life that could be understood, even if it is too slow for others, instead of a social movement to become the ‘first-person.’ However, the organization which has covered most of the necessary finances with many public and privately subsidized projects have constantly demanded results, which has required their competence. Mentally challenged people in the organization have lost their place amid positive and negative feedback from the subjects of the projects. In the end, the organization lost its power and collapsed, as the ousted people gathered and accused their former representatives. Through this case stud y, I have shown that the method of the projects based on Sanism that supported the survival of the mentally challenged-led movement was the direct cause of conflict within the organization, and it eliminated the possibility of a social movement that focused on the subjectivity of the ‘first-person’.