Density Correlation of Solubility of C. I. Disperse Orange 30 Dye in Supercritical Carbon Dioxide

Baek, Jong-Kook,Kim, Sunwook,Lee, Gwang-Soo,Shim, Jae-Jin 한국화학공학회 2004 Korean Journal of Chemical Engineering Vol.21 No.1

The solubility of C.I. Disperse Orange 30 (O30) dye in CO_(2) has been measured by using a closed-loop(batch) solid-fluid equilibrium apparatus at temperatures between 313 and 393K and at pressures between 11 and 33MPa. Kumar and Johnston's equation based on Chrastil's concept has been used to describe the experimental solubility data. The solubility versus density plot appears much simpler than the solubility versus pressure plot. The isotherms are nearly straight and parallel to each other, as seen in the previous studies. Peng-Robinson equation of state (PR EOS) has also been used successfully in modeling the dye solubility in supercriticial carbon dioxide as a function of pressure or density of the fluid phase. The validity of this method has been verified by the vapor pressure calculation.

Occult papillary thyroid carcinoma presenting with cervical neck lymph node metastasis

Sunwook Han,Sunghoon Hong,Jongeun Lee,Sungyong Kim,Moo-Jun Baek 대한종양외과학회 2019 Korean Journal of Clinical Oncology Vol.15 No.2

A 74-year-old male patient was conducted total thyroidectomy with functional neck dissection and final pathologic report confirm occult thyroid carcinoma. Although the frequency of occult thyroid cancer (OTC) has decreased owing to developments in cervical ultrasonography and improved accuracy of histological tests, rare cases are still reported. Due to the decreased frequency of OTC, a benign cervical neck lymph node mass is sometimes diagnosed, which can result in delays to more accurate diagnoses and appropriate treatment. Therefore, we report our case.

Analysis of Rice Grain and Morphological Characteristics in 3D Model Generated from Multi-Camera UAV Images

( Md Nasim Reza ),( Sunwook Baek ),( Sang-eon Oh ),( Kyeonghwan Lee ) 한국농업기계학회 2019 한국농업기계학회 학술발표논문집 Vol.24 No.1

Advanced crop management is an important issue in the field of precision agriculture. Rice yield estimation during crop growing season is a significant indicator and plant parameters, such as leaf area index, height, stem diameter, biomass, etc. are highly related with yield to analyze the impact of crop management practices. The traditional approaches to attain these parameters from rice field are very challenging, laborious and time-consuming. 3D geometric information based on UAV imagery of rice plant can be a relevant solution to estimate these valuable parameters. The objective of this study was to evaluate the application of the 3D model generated from low altitude UAV based multi-camera images to analyze rice grain and estimate plant height and biomass. We flied DJI S1000 octocopter with a camera bracket beneath it. The bracket was designed to hold three Sony alpha a5100 digital cameras with one nadir and two oblique views on the ground. RGB images were taken from a height of 10m using autoflight and predesigned flight path. With these images being processed into 3D point clouds, which were subsequently used to generate 3D model of rice plants. We designed an algorithm to recognize grain and measure height and biomass from the 3D model. The classification of ground and vegetation part was done to compute vegetation height. To identify rice grain in panicles, we applied regionprops and object featured segmentation. Then, we applied 3D surface plotting and voxelization to measure biomass volume. The proposed method showed a strong correlation between observed and actual measurement of rice grain count, height and biomass. Multi-camera imaging was shown to be effective at 3D modelling and estimating morphological characteristics of the rice plant.

The Analysis of Rice Transplant Characteristics by using Low Altitude UAV Images

( Md Nasim Reza ),( Inseop Na ),( Sunwook Baek ),( Kyeonghwan Lee ) 한국농업기계학회 2016 한국농업기계학회 학술발표논문집 Vol.21 No.2

Manual field based monitoring is labor intensive, expansive and time consuming. To overcome this situation automatic monitoring of rice seedlings lane and growth can be done. So, we proposed an image processing technique to detect and count the rice plant lane using low altitude Unmanned Aerial vehicle (UAV) images. The main objective of the study is to make an image processing technique based on horizontal and vertical projection of low altitude RGB images obtained from UAV for automatic rice plant lane detection. The algorithm was developed as follows: the initial RGB images, convert the images to gray or binary, noise filter, vertical and horizontal projection, detection of plant lane and calculate the length width, removal of false lane, final result. An adaptive median filter was used to remove the noise and image projection method was applied to optimize the plant lane. The result of the image projection was used to detect the plant lanes in the field. The accuracy of the result was compared with the ground truth. Our method showed that it is efficient for detecting and counting the rice plant lanes. The proposed method have shown that it is able to detect and count lanes without any mechanical interferences and it may be used as an automated tool for different crops.

Lab Color Space based Rice Yield Prediction using Low Altitude UAV Field Image

( Md Nasim Reza ),( Inseop Na ),( Sunwook Baek ),( In Lee ),( Kyeonghwan Lee ) 한국농업기계학회 2017 한국농업기계학회 학술발표논문집 Vol.22 No.1

Prediction of rice yield during a growing season would be very helpful to magnify rice yield as it also allows better farm practices to maximize yield with greater profit and lesser costs. UAV imagery based automatic detection of rice can be a relevant solution for early prediction of yield. So, we propose an image processing technique to predict rice yield using low altitude UAV images. We proposed L*a*b* color space based image segmentation algorithm. All images were captured using UAV mounted RGB camera. The proposed algorithm was developed to find out rice grain area from the image background. We took RGB image and applied filter to remove noise and converted RGB image to L*a*b* color space. All color information contain in both a* and b* layers and by using k-mean clustering classification of these colors were executed. Variation between two colors can be measured and labelling of pixels was completed by cluster index. Image was finally segmented using color. The proposed method showed that rice grain could be segmented and we can recognize rice grains from the UAV images. We can analyze grain areas and by estimating area and volume we could predict rice yield.

디지털 래디오그라피 시스템에서 산란선이 영상의 화질에 미치는 영향에 관한 연구

서재홍(Jaehong Seo),정준호(Junho Jeong),신중현(Junghyeon Shin),원종훈(Jonghun Won),정선욱(Sunwook Jung),하소영(Soyoung Ha),백철하(Cheolha Baek) 한국방사선학회 2014 한국방사선학회 학술대회 논문집 Vol.8 No.1

디지털 래디오그라피 시스템에서 산란선은 피검사체와 엑스선의 반응에 의해 발생하는 근원적인 현상이다. 래디오그라피 투사영상은 일차선에 의해 형성되는 감쇠정보를 영상화 하므로 산란선은 투사영상에서 노이즈로써 작용한다. 본 연구에서는 다양한 촬영조건에서 발생하는 산란선을 빔 저지체(beam stopper)를 이용하여 정량화 하고 동시에 반 산란 그리드의 효과를 확인 하였다. 또한 산란선이 영상의 화질에 미치는 영향을 확인하기 위해 산란선에 의해 저하되는 대조도 대잡음비를 측정 하였다. 본 연구를 통해 산란선은 피검사체의 두께 및 공기층(air gap)에 지배적인 경향을 가짐을 확인 하였다. 또한 산란선은 영상의 대조도를 현저히 저하시킴을 정량적으로 측정 하였다. 산란선을 저감하기 위해 그리드를 장착함으로써 상당량의 산란선을 저감할 수 있었으나 여전히 두꺼운 피검사체에 대해 100% 이상의 산란선이 남아 있음을 확인 하였다. Scattered radiation is inherent phenomenon of x-ray, which occurs inside the subject (or patient). Therefore it cannot be avoidable but also interacts as serious noise factor because the only meaningful information of x-ray radiography is primary x-ray photons. In this study, we quantified scattered radiation for various shooting parameters and we verified the effect of anti-scatter grid. We emplyed beam stopper method to characterize scatter to primary ratio. To evaluate effect on the projection images we also calculate constrast to noise ratio with given shooting paramteres. From the experiments, we identified the scattered radiation increases for thicker patient and smaller airgap. Moreover, scattered radiation degrades contrast to noise ratio in the projection images. We find out that the anti-scatter grid reject scattered radiation effectively, however there were not fewer than 100% of scatter to primary ratio in some shooting parameters.

디지털 래디오그라피 시스템에서 산란선이 영상의 화질에 미치는 영향에 관한 연구

서재홍(Jaehong Seo),정준호(Junho Jeong),신중현(Junghyeon Shin),원종훈(Jonghun Won),정선욱(Sunwook Jung),하소영(Soyoung Ha),백철하(Cheolha Baek) 한국방사선학회 2014 한국방사선학회 학술대회 논문집 Vol.2014 No.춘계

디지털 래디오그라피 시스템에서 산란선은 피검사체와 엑스선의 반응에 의해 발생하는 근원적인 현상이다. 래디오그라 피 투사영상은 일차선에 의해 형성되는 감쇠정보를 영상화 하므로 산란선은 투사영상에서 노이즈로써 작용한다. 본 연구 에서는 다양한 촬영조건에서 발생하는 산란선을 빔 저지체(beam stopper)를 이용하여 정량화 하고 동시에 반 산란 그리 드의 효과를 확인 하였다. 또한 산란선이 영상의 화질에 미치는 영향을 확인하기 위해 산란선에 의해 저하되는 대조도 대 잡음비를 측정 하였다. 본 연구를 통해 산란선은 피검사체의 두께 및 공기층(air gap)에 지배적인 경향을 가짐을 확인 하였다. 또한 산란선은 영상의 대조도를 현저히 저하시킴을 정량적으로 측정 하였다. 산란선을 저감하기 위해 그리드를 장착함으로써 상당량의 산란선을 저감할 수 있었으나 여전히 두꺼운 피검사체에 대해 100% 이상의 산란선이 남아 있음을 확인 하였다. herefore it cannot be avoidable but also interacts as serious noise factor because the only meaningful information of x-ray radiography is primary x-ray photons. In this study, we quantified scattered radiation for various shooting parameters and we verified the effect of anti-scatter grid. We emplyed beam stopper method to characterize scatter to primary ratio. To evaluate effect on the projection images we also calculate constrast to noise ratio with given shooting paramteres. From the experiments, we identified the scattered radiation increases for thicker patient and smaller airgap. Moreover, scattered radiation degrades contrast to noise ratio in the projection images. We find out that the anti-scatter grid reject scattered radiation effectively, however there were not fewer than 100% of scatter to primary ratio in some shooting parameters.