• Korean Journal of Environmental Agriculture
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• v.8 no.1
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• pp.1-6
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• 1989

This study was performed to reveal the heavy metal contents in apple leaves, and to estimate the correlation between contents of heavy metals of orchard lands and those of apple leaves. For this experiment, the apple leaves were collected from 58 apple orchards in Korea. The results were as follows ; 1. The average heavy metal contents in apple leaves were 26.44(6,23-182,85) ppm in Cu, 0.34 (0.07-0,61) ppm in Cd and 9.47 (0.00-225.50) ppm in Pb. 2. On the simple correlation coefficients between contents of heavy metals of orchard lands and those of apple leaves, all three copper cadmium and lead were positive but cadmium was insignificanfly, correlated. There was no difference among varieties (Ralls, Jonathan, etc) in these results. 3. The 0.1N HCl extraetion proved, was more suitable than the $IN-NH_4OAC$ extraction for describing the relation-Ship between heavy metal contents of apple leaves and those of orchard lands.

• Journal of the Korean Society for Nondestructive Testing
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• v.34 no.4
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• pp.283-289
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• 2014

This study was conducted to develop a non-destructive detection method for adulterated powder products using Raman spectroscopy and partial least squares regression(PLSR). Garlic and ginger powder, which are used as natural seasoning and in health supplement foods, were selected for this experiment. Samples were adulterated with corn starch in concentrations of 5-35%. PLSR models for adulterated garlic and ginger powders were developed and their performances evaluated using cross validation. The $R^2_c$ and SEC of an optimal PLSR model were 0.99 and 2.16 for the garlic powder samples, and 0.99 and 0.84 for the ginger samples, respectively. The variable importance in projection (VIP) score is a useful and simple tool for the evaluation of the importance of each variable in a PLSR model. After the VIP scores were taken pre-selection, the Raman spectrum data was reduced by one third. New PLSR models, based on a reduced number of wavelengths selected by the VIP scores technique, gave good predictions for the adulterated garlic and ginger powder samples.

• Polymer(Korea)
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• v.29 no.2
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• pp.177-182
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• 2005

Montmorillonite (MMT) modified with siloxane diamine was reacted with a reactant obtained from 4,4'-diphenyl methane diisocyanate (MDI) and polyester type polyol, $Nippollan4010(\bar{M}_n2000)$. Finally, polyurethane (PU)/MMT composites were prepared by using 1,4-butane diol as a chain extender in $25\;wt\%$ solution of N,N-dimethyl acetamide (DMAc). It was expected that these nanocomposites had superior exfoliation property to that of MMT dispersed polyurethanes produced by simple mixing due to insertion of siloxane main chain to the silicate interlayer of MMT. Extent of reaction and formation of final products were analysed by using FT-IR spectroscopy. Dispersion into the PU and intercalation of MMT were identified by applying X-ray diffraction (XRD) and transmission electron microscopy (TEM). Tensile data were acquired by universal test machine (UTM). Thermal stability and variation of surface energy were characterized by thermal gravimetric analysis (TGA) method and measurement of contact angle on the synthesized composites, respectively. As the results the organo-MMT modified with siloxane diamine in the PU composites has an intercalated structure relatively well-expanded rather than a completely exfoliated structure. The tensile strengths and the moduli for the PU/organo-MMT composites were drastically enhanced in comparison to those of $PU/Na^+-MMT$ composites.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1121-1121
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• 2001

A previous study (Berzaghi et al., 2001) evaluated the performance of 3 calibration methods, modified partial least squares (MPLS), local PLS (LOCAL) and artificial neural networks (ANN) on the prediction of the chemical composition of forages, using a large NIR database. The study used forage samples (n=25,977) from Australia, Europe (Belgium, Germany, Italy and Sweden) and North America (Canada and U.S.A) with reference values for moisture, crude protein and neutral detergent fibre content. The spectra of the samples were collected using 10 different Foss NIR Systems instruments, only some of which had been standardized to one master instrument. The aim of the present study was to evaluate the behaviour of these different calibration methods when predicting the same samples measured on different instruments. Twenty-two sealed samples of different kind of forages were measured in duplicate on seven instruments (one master and six slaves). Three sets of near infrared spectra (1100 to 2500nm) were created. The first set consisted of the spectra in their original form (unstandardized); the second set was created using a single sample standardization (Clone1); the third was created using a multiple sample procedure (Clone6). WinISI software (Infrasoft International Inc., Port Mathilda, PA, USA) was used to perform both types of standardization, Clone1 is just a photometric offset between a “master” instrument and the “slave” instrument. Clone6 modifies both the X-axis through a wavelength adjustment and the Y-axis through a simple regression wavelength by wavelength. The Clone1 procedure used one sample spectrally close to the centre of the population. The six samples used in Clone 6 were selected to cover the range of spectral variation in the sample set. The remaining fifteen samples were used to evaluate the performances of the different models. The predicted values for dry matter, protein and neutral detergent fibre from the master Instrument were considered as “reference Y values” when computing the statistics RMSEP, SEPC, R, Bias, Slope, mean GH (global Mahalanobis distance) and mean NH (neighbourhood Mahalanobis distance) for the 6 slave instruments. From the results we conclude that i) all the calibration techniques gave satisfactory results after standardization. Without standardization the predicted data from the slaves would have required slope and bias correction to produce acceptable statistics. ii) Standardization reduced the errors for all calibration methods and parameters tested, reducing not only systematic biases but also random errors. iii) Standardization removed slope effects that were significantly different from 1.0 in most of the cases. iv) Clone1 and Clone6 gave similar results except for NDF where Clone6 gave better RMSEP values than Clone1. v) GH and NH were reduced by half even with very large data sets including unstandardized spectra.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.5
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• pp.635-643
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• 2018

This paper propose a method to identify the motor parameters and improve input voltage error which affect the low speed position error of the back-emf(back electromotive force) based sensorless algorithm and to secure the operation reliability and stability even in the case where the load fluctuation is severe and the start and low speed operation frequently occurs. In the model-based observer used in this paper, stator resistance, inductance, and input voltage are particularly influential factors on low speed performance. Stator resistance can cause resistance value fluctuation which may occur in mass production process, and fluctuation of resistance value due to heat generated during operation. The inductance is influenced by the fluctuation due to the manufacturing dispersion and at a low speed where the change of the current is severe. In order to find stator resistance and inductance which have different initial values and fluctuate during operation and have a large influence on sensorless performance at low speed, they are commonly measured through 2-point calculation method by 2-step align current injection. The effect of voltage error is minimized by offsetting the voltage error. In addition, when the command voltage is used, it is difficult to estimate the back-emf due to the relatively large distortion voltage due to the dead time and the voltage drop of the power device. In this paper, we propose a simple circuit and method to detect the voltage by measuring the PWM(Pulse Width Modulation) pulse width and compensate the voltage drop of the power device with the table, thereby minimizing the position error due to the exact estimation of the back-emf at low speed. The suitability of the proposed algorithm is verified through experiment.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.2
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• pp.10-16
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• 2000

The purpose of this study is to identify relationships between a central angle and a radius of curvature of divided roads in flat terrain of traditional villages, suggesting layout criteria for traditional villages: Nak-an, Sung-Eup, Ha-Whe. This study is sought to find the optimum model through the various SAS regression analyses. a regression analysis of this data was adopted to induce the relationship formula between a central angle of curve and a radius of curvature. Results of this study are as follows: 1) Most of the divided roads in traditional villages have a complex curve rather than a simple curve. 2) A central angle of curve has ranged from 11$^{\circ}$to 127$^{\circ}$, with a mean degree of 63.9. 3) In the lower level of central angle(11-40$^{\circ}$), the branch roads have distributed with a high frequency, but with a low frequency in the higher level of central angle(90-140$^{\circ}$). 4) A radius of curvature in the divided roads has ranged from 0.9m to 59.6, but half of the roads have concentrated on 1-6m of the curvature. 5) Compared to the result of hilly villages in previous study(Ahn, 1999), value of central angels in flat villages is lower than that of hilly villages, while a mean value of the curvature is higher than that of hilly villages. 6) A Non-linear regression analysis, resulting from the SAS application, was useful method to induce a relationship formula between a central angle and a radius of curvature in the branch roads. Our study's formula is as follow: R=100.3*EXP(-0.06*$\delta$)+3.91. 7) Our study model has less error than that of the Kishizuka's method, being applicable to a broader range of the branch roads. 8) A minimum radius of curvature in our study has showed 3.9m, suggesting to reconsider applications of the Kishizuka's(5.8m) in the footpass design, In the study for this presupposition model the efficiency and utility of it can be estimated to grow large according to how much and how far it includes both extremes of data. This study is for the application to a design in future through the numerical formula of divided roads of various traditional villages. The studies from now on will be about the quasi-hilly quasi-hilly village and hilly village supplementing these factors more.

• Archives of Plastic Surgery
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• v.36 no.3
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• pp.336-340
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• 2009

Purpose: The wound of a patient who has chronic venous insufficiency is easy to recur. Also they develop a complication even after the conservative therapy or skin graft. We have to diagnose the venous stasis ulcer correctly and remove the cause to improve the effectiveness of treatment. We operated endoscopic perforating vein ligation and splitt thickness skin graft on a patient with venous stasis ulceration on right leg. Methods: A 26 year old male patient who had a scalding burn on his right leg in July 2005 checked into our hospital in March 2008. Even though he got three operations - the split thickness skin graft - at different clinics, the wound did not heal. The size of the wound was 12 by $8cm^2$ and granulation with edema and fibrosis had been formed. We kept observation on many collateral vessels and perforating vein through venogram and doppler sonography and firmly get to know that the wound came with chronic venous insufficiency. After a debridement and an application of VAC$^{(R)}$ for two weeks, the condition of granulation got better. So we proceeded with the operation using subfascial endoscopic perforating surgery and split thickness skin graft. Results: Through the venogram after the operation, we found out that the collateral vessels had been reduced compared to the previous condition and the widened perforating vein disappeared. During a follow up of 6 months, the patient did not develop recurrent stasis ulcer and postoperative complications. Conclusion: Subfascial endoscopic perforator ligation is relatively simple technique with a low complication rate and recurrence rate. Split thickness skin graft with subfascial endoscopic perforator surgery can be valuable method for treating severe venous stasis ulcers.

• Journal of the Korean Wood Science and Technology
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• v.41 no.4
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• pp.358-373
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• 2013

In this study, both mild acid and alkali treatments with 1.0 wt% and 2.0 wt% of $H_2SO_4$ and NaOH solution were applied to evaluate the effects on chemical compositions of wood biomass. Yellow poplar (Liriodendron tulipifera L.) and larch (Larix kaempferi C.) were chosen due to major species planted in Korea. Chemical treatments of biomass were carried out by being soaked in either acid or alkali solution with 1:20 ratio for 72 hours at ambient temperature. Afterward, lignin, 5 major reduced sugars, ash contents and elemental composition were determined. To statistically understand the relationship between samples and chemical treatments, the Tukey test, simple linear regression model and ANOVA analysis were introduced using a statistical software R. As results from both wet chemistry and statistical analysis, yellow poplar was more affected on the lignin and xylose contents by acid treatments under these experimental conditions. Meanwhile, larch was more affected on the composition of galactose and lignin by alkali treatments. A series of results in this study would show that equivalent chemical treatment makes a change the chemical composition of each species.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.8
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• pp.572-577
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• 2011

The unit load has simply been used to estimate total pollutant loading from non-point sources, however, it does not count on the variable pollutant loading according to land use characteristics and rainfall intensity. Since pollutant emission from the watershed is strongly dependent on the rainfall intensity, it is necessary to find out the relationship between pollutant loading and rainfall intensity. The objective of this study is to develop simple and easy method to compute non-point source pollution loads with consideration of rainfall intensity. Two non-point source removal facility at Gyeongan-dong (Gwangju-si) and Mohyeon-myeon (Yongin-si), Gyeonggi-do was selected to monitor total rainfall, rainfall intensity, runoff characteristics and water quality from June to November, 2010. Most of Event Mean Concentrations (EMC) of measured water quality data were higher in Gyeongan which has urban land use than in Mohyeon which has rural land use. For the case of TP (Total Phosphorus), Mohyeon has higher values by the influence of larger chemical uses such as fertilizer. The relationship between non-point source pollution load and rainfall intensity is perfectly well explained by cubic regression with 0.33~0.81 coefficients of determination($R^2$). It is expected that the pollution loading function based on the long-term monitoring would be very useful with good accuracy in computing non-point source pollution load, where a rainfall intensity is highly variable.

• Applied Biological Chemistry
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• v.46 no.2
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• pp.140-143
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• 2003

This study was performed to develop a more rapid and simple nutrient diagnosis method of plants than the conventional leaf analysis method. tomato (Lycopersicon esculentum Mill. cv. super momotaro) was planted in the mixed media produced by mixing perlite and rock wool at 1 . 1 (v/v) ratio. The Yamazakki nutrient solutions for cucumber and tomato were supplied to the media using the micro-drip irrigation system. Experimental plots produced consisted of no fertilization, deficient fertilization, adequate fertilization and surplus fertilization for N, P and K, respectively. Each experimental plot was replicated four times. Specific color different sensor values (SCDSV) measured by the chlorophyll meter were closely related to total-N concentrations in the leaves measured by the conventional method. Nitrate, $PO_4$ and K concentrations in petiole sap measured by test strips #(Reflectoquant^{\circledR},\;Merck,\;Germany)$ showed a significant relationship with total-N, p and K concentrations in leaves. The linear regression equations between $NO_3,\;PO_4$ and K concentrations in petiole sap and total-N, p and K concentrations in the leaves were prepared. The optimum levels of $NO_3,\;PO_4$ and K in petiole sap were obtained by plugging the optimum concentrations of total-N, p and K in the leaves by other researchers into the equations. In conclusion, the SCDSV by the chlorophyll meter and concentrations of NO3, p and K in petiole sap measured by the test strips would be suitable for rapid estimation of plant nutrient status.