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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Biosystems Engineering
Journal Basic Information
Journal DOI :
Korean Society for Agricultural Machinery
Editor in Chief :
Volume & Issues
Volume 33, Issue 6 - Dec 2008
Volume 33, Issue 5 - Oct 2008
Volume 33, Issue 4 - Aug 2008
Volume 33, Issue 3 - Jun 2008
Volume 33, Issue 2 - Apr 2008
Volume 33, Issue 1 - Feb 2008
Selecting the target year
Adoptability Review of a Rotor Airfoil (SW05) to an Agricultural Unmanned Helicopter Using CFD Analysis
Jung, Han-Kyung ; Koo, Young-Mo ;
Journal of Biosystems Engineering, volume 33, issue 5, 2008, Pages 289~295
DOI : 10.5307/JBE.2008.33.5.289
The task of chemical spraying has been seriously considered as an irritating and annoying job for Korean rice farmers. An agricultural unmanned helicopter was suggested to solve this problem so as the farmers to have more decent farming condition. The objectives of this study were to analyze the adoptability of an experimental rotor blade (SW05) using the CFD simulation and also to compare the simulation results with experimental results. The simulation results showed that the induced power of this rotor reached to
of total power and the profile power was about
of total power. Therefore it can be concluded that this rotor's performance characteristics were not so efficient for the size of unmanned helicopter due to the low induced power and high profile power relatively compared with ones of conventional rotors. The comparison with experimental results showed that the tested lifts were less than 70% of simulated ones at the grip pitch of
and decreased to 40% at the
grip pitch. Therefore, it can be concluded that the rotor was too oversized to be used for a 15.4 kW (21 PS) engine.
Estimation of Effective Moisture Diffusivity of Rapeseed (Brassica napus L.)
Duc, Le Ahn ; Hong, Sang-Jin ; Han, Jae-Woong ; Keum, Dong-Hyuk ;
Journal of Biosystems Engineering, volume 33, issue 5, 2008, Pages 296~302
DOI : 10.5307/JBE.2008.33.5.296
The effective moisture diffusivity and its dependence on drying temperature during drying of rapeseed were experimentally investigated. The data were recorded from thin layer drying experiments at nine different combinations of drying air temperatures of 40, 50, and
and the relative humidities of 30, 45, and 60%. The moisture diffusion equation was analyzed using stepwise multiple regression analysis. Effective moisture diffusivities were calculated based on the moisture diffusion equation for a spherical shape using Fick's second law. The effective diffusivities during the drying of rapeseed were
at 40, 50 and
, respectively. The activation energy for moisture diffusion during drying was
. The dependence of moisture diffusivity on temperature was described by an Arrhenius-type equation. Drying occurred in the falling rate period and the internal moisture diffusion phenomenon is the governing physical mechanism of the moisture movement in the particles.
Cold Thermal Energy Storage Characteristics of Spherical PCM Capsule
Yun, Hong-Sun ; Kwon, Jin-Kyung ; Jeong, Hoon ; Lee, Hyun-Dong ; Kim, Young-Geon ;
Journal of Biosystems Engineering, volume 33, issue 5, 2008, Pages 303~308
DOI : 10.5307/JBE.2008.33.5.303
The freezing characteristics of two kinds of phase change materials (PCM) encapsulated in a spherical container were investigated with various cooling air temperatures and velocities. The super cooling and solidification time of PCM were highly affected by cooling air temperature and velocity. The experimental equations are derived to express total solidification time of the PCM in terms of Nusselt number and dimensionless temperature.
Development of Prediction Model to Estimate the Storage Days of Tomato Using Transmittance Spectrum
Kim, Young-Tae ; Suh, Sang-Ryong ;
Journal of Biosystems Engineering, volume 33, issue 5, 2008, Pages 309~316
DOI : 10.5307/JBE.2008.33.5.309
The goal of this study was to develop prediction models to estimate the storage days of tomato. The transmittance spectral data measured on tomato were preprocessed through normalization, SNV, Savitzky-Golay, and Norris Gap and then were used to build the prediction models using partial least square (PLS) method. For the experiments, the tomato samples of different varieties were collected at different harvest time. The samples were taken right after harvest from the field and then were stored in a low-temperature storage room in which room temperature was maintained at
. The transmittance spectral data of the tomato samples were measured at three-day intervals for 16 days. The performance of the prediction models was affected by the preprocessing techniques as well as the varieties and harvest time of the tomato. The best model was found when SNV was applied. The accuracy of the best model was 90.2%. It can be concluded that the transmittance spectra are useful information for predicting the period of storage of tomato.
Analysis of QRS-wave Using Wavelet Transform of Electrocardiogram
Choi, Chang-Hyun ; Kim, Yong-Joo ; Kim, Tae-Hyeong ; Ahn, Yong-Hee ; Shin, Dong-Ryeol ;
Journal of Biosystems Engineering, volume 33, issue 5, 2008, Pages 317~325
DOI : 10.5307/JBE.2008.33.5.317
The electrocardiogram (ECG) measurement system consists of I/O interface to input the ECG signals from two electrodes, FPGA (Field programmable gate arrays) module to process the signal conditioning, and real time module to control the system. The algorithms based on wavelet transform were developed to remove the noise of the ECG signals and to determine the QRS-waves. Triangular wave tests were conducted to determine the optimal factors of the wavelet filter by analyzing the SNRs (signal to noise ratios) and RMSEs (root mean square errors). The hybrid rule, soft method, and symlets of order 5 were selected as thresholding rule, thresholding method, and mother wavelet, respectively. The developed wavelet filter showed good performance to remove the noise of the triangular waves with 10.98 dB of SNR and 0.140 mV of RMSE. The ECG signals from a total of 6 subjects were measured at different measuring postures such as lying, sitting, and standing. The durations of QRS-waves, the amplitudes of R-waves, the intervals of RR-waves were analyzed by using the finite impulse response (FIR) filter and the developed wavelet filter. The wavelet filter showed good performance to determine the features of QRS-waves, but the FIR filter had some problems to detect the peaks of Q and S waves. The measuring postures affected accuracy and precision of the ECG signals. The noises of the ECG signals were increased due to the movement of the subject during measurement. The results showed that the wavelet filter was a useful tool to remove the noise of the ECG signals and to determine the features of the QRS-waves.
Development of Pneumography Impedance Based Respiration Measurement System Using Kalman Filter
Nam, Eun-Hye ; Choi, Chang-Hyun ; Kim, Yong-Joo ; Shin, Dong-Ryeol ;
Journal of Biosystems Engineering, volume 33, issue 5, 2008, Pages 326~332
DOI : 10.5307/JBE.2008.33.5.326
A respiration measurement system for vital signs was developed. Respiration signals were measured, processed, and analyzed. Four electrodes, attached on the surface of the skin, were used to monitor respiration signals by impedance pneumography. The measured signals were amplified, detrended, filtered, and transferred toan embedded module. The Kalman filter was used to remove motion artifact from the respiration signals. Experiments were conducted at stable condition and walking condition to evaluate the performance of the system. Respiration rates of five males and five females were measured and analyzed at each condition. The referenced respiration signal was determined by temperature of nose surroundings. The results showed that the respiration rates at the walking condition had more motion artifacts than the stable condition. The accuracies of the respiration measurement system with Kalman filter were found as 96% at the stable condition and 95% at the walking condition. The results showed that the Kalman filter was an effective tool to remove the motion artifact from the respiration signal.
Development of a Portable Electronic Nose System (I) - System Development -
Lee, Jeong-Woo ; Kim, Seong-Min ;
Journal of Biosystems Engineering, volume 33, issue 5, 2008, Pages 333~339
DOI : 10.5307/JBE.2008.33.5.333
The purpose of this study was to develop a portable electronic nose system to measure volatile components of agricultural and food products. Also, a graphical operating software to control the electronic nose system and to acquire signals through the Internet was developed. An array of five commercial metal oxide gas sensors was used to detect various volatile gas components of target samples. Transient and steady state signals were analyzed to extract variables related to sample states, To find optimal operating conditions of the system, several experiments were performed with different gas chambers, vacuum pumps, gas sampling temperatures, and sample container sizes. The patterns of gas sensor signals were analysed to find effects of the various conditions.
Classification of UTI Using RBF and LVQ Artificial Neural Network in Urine Dipstick Screening Test
Min, Kyoung-Kee ; Kang, Myung-Seo ; Shin, Ki-Young ; Lee, Sang-Sik ; Hun, Joung-Hwan ;
Journal of Biosystems Engineering, volume 33, issue 5, 2008, Pages 340~347
DOI : 10.5307/JBE.2008.33.5.340
Dipstick urinalysis is used as a routine test for a screening test of UTI (urinary tract infection) in primary practice because urine dipstick test is simple. The result of dipstick urinalysis brings medical professionals to make a microscopic examination and urine culture for exact UTI diagnosis, therefore it is emphasized on a role of screening test. The objective of this study was to the classification between UTI patients and normal subjects using hybrid neural network classifier with enhanced clustering performance in urine dipstick screening test. In order to propose a classifier, we made a hybrid neural network which combines with RBF layer, summation & normalization layer and L VQ artificial neural network layer. For the demonstration of proposed hybrid neural network, we compared proposed classifier with various artificial neural networks such as back-propagation, RBFNN and PNN method. As a result, classification performance of proposed classifier was able to classify 95.81% of the normal subjects and 83.87% of the UTI patients, total average 90.72% according to validation dataset. The proposed classifier confirms better performance than other classifiers. Therefore the application of such a proposed classifier expect to utilize telemedicine to classify between UTI patients and normal subjects in the future.
Automatic Eggshell Crack Detection System for Egg Grading
Choi, Wan-Kyu ; Lee, Kang-Jin ; Son, Jae-Ryong ; Kang, Suk-Won ; Lee, Ho-Young ;
Journal of Biosystems Engineering, volume 33, issue 5, 2008, Pages 348~354
DOI : 10.5307/JBE.2008.33.5.348
Egg grading is determined by exterior and interior quality. Among the evaluation methods for the egg quality, a candling method is common to identify eggs with cracked shells and interior defects. But this method is time-consuming and laborious. In addition, practically, it is challenging to detect hairline and micro cracks. In this study, an on-line inspection system based on acoustic resonance frequency analysis was developed to detect hairline cracks on eggshells. A roller conveyor was used to transfer eggs along one lane to the impact position where each of eggs rotated by the roller was excited with an impact device at four different locations on the eggshell equator. The impact device was consisted of a plastic hammer and a rotary solenoid. The acoustic response of the egg to the impact was measured with a small condenser microphone at the same position as the impact device was installed. Two acoustic parameters, correlation coefficient for normalized power spectra and standard deviation of peak resonant frequencies, were used to detect cracked eggs. Intact eggs showed relatively high correlations among the four normalized power spectra and low standard deviations of the four peak resonant frequencies. On the other hand, cracked eggs showed low correlations and high standard deviations as compared to the intact. This method allowed a crack detection rate of 97.6%.
Spectral Analysis of On-the-go Soil Strength Sensor Data
Chung, Sun-Ok ; Suduth, Kenneth A. ; Tan, Jinglu ;
Journal of Biosystems Engineering, volume 33, issue 5, 2008, Pages 355~361
DOI : 10.5307/JBE.2008.33.5.355
As agricultural machinery has become larger and tillage practices have changed in recent decades, compaction as a result of wheel traffic and tillage has caused increasing concern. If strategies to manage compaction, such as deep tillage, could be applied only where needed, economic and environmental benefits would result. For such site-specific compaction management to occur, compacted areas within fields must be efficiently sensed and mapped. We previously developed an on-the-go soil strength profile sensor (SSPS) for this purpose. The SSPS measures within-field variability in soil strength at five soil depths up to 50 cm. Determining the variability structure of SSPS data is needed for site-specific field management since the variability structure determines the required intensity of data collection and is related to the delineation of compaction management zones. In this paper, soil bin data were analyzed by a spectral analysis technique to determine the variability structure of the SSPS data, and to investigate causes and implications of this variability. In the soil bin, we observed a repeating pattern due to soil fracture with an approximate 12- to 19-cm period, especially at the 10-cm depth, possibly due to cyclic development of soil fracture on this interval. These findings will facilitate interpretation of soil strength data and enhance application of the SSPS.
Analysis of Spatial Variability in a Korean Paddy Field Using Median Polish Detrending
Chung, Sun-Ok ; Jung, In-Kyu ; Sung, Je-Hoon ; Sudduth, Kenneth A. ; Drummond, Scott T. ;
Journal of Biosystems Engineering, volume 33, issue 5, 2008, Pages 362~369
DOI : 10.5307/JBE.2008.33.5.362
There is developing interest in precision agriculture in Korea, despite the fact that typical Korean fields are less than 1 ha in size. Describing within-field variability in typical Korean production settings is a fundamental first step toward determining the size of management zones and the inter-relationships between limiting factors, for establishment of site-specific management strategies. Measurements of rice (Oriza Sativa L) yield, chlorophyll content, and soil properties were obtained in a small (100-m by 30-m) Korean rice paddy field. Yield data were manually collected on 10-m by 5-m grids (180 samples with 3 samples in each of 60 grid cells) and chlorophyll content was measured using a Minolta SPAD 502 in 2-m by 2-m grids. Soil samples were collected at 275 points to compare results from sampling at different scales. Ten soil properties important for rice production in Korea were determined through laboratory analyses. Variogram analysis and point kriging with and without median polishing were conducted to determine the variability of the measured parameters. Influence of variogram model selection and other parameters on the interpretation of the data was investigated. For many of the data, maximum values were greater than double the minimum values, indicating considerable spatial variability in the small paddy field, and large-scale spatial trends were present. When variograms were fit to the original data, the limits of spatial dependency for rice yield and SP AD reading were 11.5 m and 6.5 m, respectively, and after detrending the limits were reduced to 7.4 m and 3.9 m. The range of spatial dependency for soil properties was variable, with several having ranges as short as 2 m and others having ranges greater than 30 m. Kriged maps of the variables clearly showed the presence of both large-scale (trend) variability and small-scale variability in this small field where it would be reasonable to expect uniformity. These findings indicate the potential for applying the principles and technology of precision agriculture for Korean paddy fields. Additional research is needed to confirm the results with data from other fields and crops.d similar tendency with the result for the frequency less than 20 Hz, but the width of change was reduced highly.