• Applied Biological Chemistry
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• v.19 no.1
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• pp.24-30
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• 1976

Rhizomes of the common reed (Phragmites communis Trin.) were incubated for three days in the dark. Methanol extract of the shoots was thin layer chromatographed with several solvent systems and visualized with five reagents. The results may be summarized as follows: 1. Serotonin, tryptophan, and tryptamine were identified by cochromatography with the respective authentic compounds. Bufotenine, N-methylserotonin, and N,N-dimethyltryptamine were tentatively identified by their Rf values and colour reactions. The presence of skatole and gramine was suggested. 2. It was esteemed that the common reed might have an active methylation/hydroxylation system of indole compounds at least for a period of time. 3. The presently devised 'overlap' thin layer chromatographic technique may be a useful tool for the identification of a compound whose Rf value was diverse from that of the authentic one by the interferance containing in a sample material.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.8
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• pp.875-881
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• 2014

The redundancy resolution of the seven DOF (Degree of Freedom) upper limb exoskeleton is key to the synchronous motion between a robot and a human user. According to the seven DOF human arm model, positioning and orientating the wrist can be completed by multiple arm configurations that results in the non-unique solution to the inverse kinematics. This paper presents analysis on the kinematic and dynamic aspect of the human arm movement and its effect on the redundancy resolution of the seven DOF human arm model. The redundancy of the arm is expressed mathematically by defining the swivel angle. The final form of swivel angle can be represented as a linear combination of two different swivel angles achieved by optimizing two cost functions based on kinematic and dynamic criteria. The kinematic criterion is to maximize the projection of the longest principal axis of the manipulability ellipsoid of the human arm on the vector connecting the wrist and the virtual target on the head region. The dynamic criterion is to minimize the mechanical work done in the joint space for each of two consecutive points along the task space trajectory. The contribution of each criterion on the redundancy was verified by the post processing of experimental data collected with a motion capture system. Results indicate that the bimodal redundancy resolution approach improved the accuracy of the predicted swivel angle. Statistical testing of the dynamic constraint contribution shows that under moderate speeds and no load, the dynamic component of the human arm is not dominant, and it is enough to resolve the redundancy without dynamic constraint for the realtime application.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.12
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• pp.1106-1114
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• 2012

To achieve synchronized motion between a wearable robot and a human user, the redundancy must be resolved in the same manner by both systems. According to the seven DOF (Degrees of Freedom) human arm model composed of the shoulder, elbow, and wrist joints, positioning and orientating the wrist in space is a task requiring only six DOFs. Due to this redundancy, a given task can be completed by multiple arm configurations, and thus there exists no unique mathematical solution to the inverse kinematics. This paper presents analysis on the kinematic and dynamic aspect of the human arm movement and their effect on the redundancy resolution of the human arm based on a seven DOF manipulator model. The redundancy of the arm is expressed mathematically by defining the swivel angle. The final form of swivel angle can be represented as a linear combination of two different swivel angles achieved by optimizing different cost functions based on kinematic and dynamic criteria. The kinematic criterion is to maximize the projection of the longest principal axis of the manipulability ellipsoid for the human arm on the vector connecting the wrist and the virtual target on the head region. The dynamic criterion is to minimize the mechanical work done in the joint space for each two consecutive points along the task space trajectory. As a first step, the redundancy based on the kinematic criterion will be thoroughly studied based on the motion capture data analysis. Experimental results indicate that by using the proposed redundancy resolution criterion in the kinematic level, error between the predicted and the actual swivel angle acquired from the motor control system is less than five degrees.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.11
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• pp.1199-1206
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• 2012

Recently, technologies to help the elderly or disabled people who have difficulty in walking are being developed. In order to develop these technologies, it is necessary to construct a system that gathers the gait data of people and analysis of these data is also important. In this research, we constructed the development of sensor system which consists of pressure sensor, three-axis accelerometer and two-axis gyro sensor. We used k-means clustering algorithm to classify the data for characterization, and then calculated the symmetry index with histogram which was produced from each cluster. We collected gait data from sensors attached on two subjects. The experiment was conducted for two kinds of gait status. One is walking with normal gait; the other is walking with abnormal gait (abnormal gait means that the subject walks by dragging the right leg intentionally). With the result from the analysis of acceleration component, we were able to confirm that the analysis technique of this data could be used to determine gait symmetry. In addition, by adding gyro components in the analysis, we could find that the symmetry index was appropriate to express symmetry better.

• Applied Biological Chemistry
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• v.14 no.3
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• pp.177-182
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• 1971

A new method for the measure of iron pools using 0.02M EDTA and $Na_2S_2O_4$ was tested on Akagare diseased and healthy rice leaf tissue 1) The proposed method could fraction iron into four fractions; ferrous iron($Fe^{++}$), ferric iron($Fe^{+++}$) precipitated iron(PFe) and bound iron(BFe) well indicating the physiological status of tissue. 2) The pattern of iron pools appears to be $Fe^{+++}>PFe>BFe>Fe^{++}$ in most physiologically favorable status of iron, $PFe>Fe^{+++}>BFe>Fe^{++}$ in favorable status, $BFe>Fe^{+++}>PFe>Fe^{++}$ in unfavorable status and $BFe>PFe>Fe^{+++}>Fe^{++}$ in toxic status. 3) The percentage of each fraction to total iron was less than 10 for $Fe^{++}$, 20 to 40 for $Fe^{+++}$ and PFe and 20 to 50 for BFe. 4) Ferrous iron was always higher in upper half leaf, the appearance of which is less healthier than lower half indicating that there is more active metabolic system in which ferrous iron is involved.

• Applied Biological Chemistry
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• v.12
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• pp.115-118
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• 1969

In a series of studies on the formation processes and chemical properties of humic substances from paddy soils the photoabsorption spectra of hymatomelanic and humic acids were recorded in the visible, ultraviolet and infrared regions. The spectra patterns of both fractions in the visible range were indicative of the decrease in optical density with the rise of wavelength and the UV-spectra showed the maximum peak at $235\;m{\mu}$, the minimum at $395\;m{\mu}$. The IR-spectra indicate a typical pattern showing a few sharp peaks in both fractions. The spectra of both fractions were compared and discussed.

• Applied Biological Chemistry
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• v.6
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• pp.33-36
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• 1965

1. The extraction of securine, an alkaloid, from Securinega suffruticosa Rehder growing in Korea was investigated. 2. The distribution of the source plant in Korea is considered to be most intense among the Fareast countries. 3. The extracted material was identified to be genuine securinine viewing from melting point and microscopic observation. 4. The yield of the substance in this study was 0.075% in average. The less amount of recovery may be due to the collection of the plant in October instead of that in the prime season. 5. There should be more efficient way in the separation of resinous impurities from the crude product. Application of Chromatographic technique and selection of more efficient solvent will be investigated hereafter.

• Applied Biological Chemistry
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• v.19 no.2
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• pp.65-69
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• 1976

Methanolic extract of the common reed sprouts (Phragmites communis Trin.), unincubated or incubated at $27^{\circ}C$ in the dark, was subjected to thin layer chromatography for the indole compounds. Serotonin, tryptophan and tryptamine were the major indoles in the unincubated sprouts. At early stage of incubation of sprouts, however, serotonin and tryptamine decreased while other indoleamines increased. Tryptophan remained constant throughout the incubation periods. From the observation in the present study, it was speculated that serotonin be synthesized from tryptophan via tryptamine and in turn metabolized to bufotenine.

• Journal of Ginseng Research
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• v.1 no.1
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• pp.51-58
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• 1976

The phenomenon of sail sickness in the continuous cropping of ginseng is n serious problem for the cultivation practices and is an unelucidated subject scientifically. Present study is concerned mainly with ecochemical search on the cause of soil sickness in the continuous cropping of ginseng and the obtained results are summarized as follows: The humic substances isolated from both cultivated and uneulvidated soils with ginseng were compared with respect to its IR spectra but any difference which may be causative of sail sickness between them was not detected. In contrast, same saponin-like substances extracted from the ginseng cultivate soil in root tone were detected but not from the uncultivated soil. Presumably. the saponin like substances in the soils are originate) from the ginseng radices and are accumulaetd in root zone year by year, while the interrelation between the root exudate of ginseng and soil sickness is still obscure. According to a survey on the distributive Pattern of microflora in rhizosphere of ginseng radices the number of fungi is relatively diminished with the cul tivation years, while the number of actinomycetes is increased. It is supposed that the soil sickness in the continuous cropping of ginseng has any correlation between the activities of microflora in rhizosphere and the reef exudates.

• Korean Journal of Food Science and Technology
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• v.3 no.2
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• pp.101-104
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• 1971

The dye-binding method based on the reaction of acidic orange-G dye with basic groups of protein molecule was investigated to observe its applicability to the determination of protein, basic amino acid and lysine contents in brown rice of several high-protein rice lines. The protein content of rice samples ranged from 7.91 to 10.53% and from 8.93 to 11.96% in terms of wet and dry bases, respectively. The correlation between dye-binding absorbance and protein content in terms of both dry and wet bases was highly significant; their correlation coefficients being $-0.955^{**}\;and\;-0.975^{**}$, respectively. The correlation of dye-binding absorbance lysine and basic amino acids were highly significant and their correlation coefficients were similar. Dye-binding absorbance-lysine showed a lower correlation than dye-binding absorbance-protein but a higher correlation than protein-lysine.