• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.5
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• pp.792-798
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• 2015

Joint angle generally can be measured to check the recovery process in rehabilitation field. This paper suggests to measure joint angle with Infrared sensor based on triangulation principle. We performed various experiments to find the optimal condition of the sensor’s attached distance, height, and angle. The results were compared with commercial goniometer for accuracy. The proposed infrared joint angle sensor can be effectively used in rehabilitation and sport science fields.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.175-175
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• 2017

To understand molecular mechanisms underlying adaptation of plant cells to saline stress and stress memory, we developed Arabidopsis callus suspension-cultured cells adapted to high salt. Adapted cells to high salt exhibited enhanced tolerance compared to control cells. Moreover, the salt tolerance of adapted cells was stably maintained even after the stress is relieved, indicating that the acquired salt tolerance of adapted cells was memorized. In order to characterize metabolic responses of plant cells during adaptation to high salt stress as well as stress memory, we compared metabolic profiles of salt-adapted and stress-memorized cells with control cells by using NMR spectroscopy. A principle component analysis showed clear metabolic discrimination among control, salt-adapted and stress-memorized cells. Compared with control cells, metabolites related to shikimate metabolism such as tyrosine, and flavonol glycosides, which are related to protective mechanism of plant against stresses were largely up-regulated in adapted cell lines. Moreover, coniferin, a precursor of lignin, was more abundant in salt-adapted cells than control cells. Cell morphology analysis using transmission electron microscopy indicated that cell wall thickness of salt-adapted cells was significantly induced compared to control cells. Consistently, salt adapted cells contained more lignin in their cell walls compared to control cells. The results provide new insight into mechanisms of plant adaptation to saline stress as well as stress memory in metabolic level.

• Transactions of the Korean hydrogen and new energy society
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• v.14 no.3
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• pp.187-194
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• 2003

The production of hydrogen fuel depends basically on the water electrolysis. The study on the decrease of overpotential which activates the hydrogen production is the core to elevate the hydrogen production efficiency on principle. Characteristics on the overpotential decrease are observed through the micro reaction by ultrasonic in electrolytic cell. For the above, the electrochemical analyzer, i.e., BAS is applied, Experiments with ultrasonic forcing into 4 kinds of solution such as city water, city water plus nitrogen. distilled water, and distilled water plus nitrogen are carried out. And concentrations of KOH are 0%, 10%, 20% and 30%. The basic characteristics of the overpotential decrease are obtained through the analysis by LSV technique in sweep technique. In results, it is clarified that the ultrasonic influences the decrease of overpotential to obtain the efficiency elevation of hydrogen fuel production.

• Advances in Traditional Medicine
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• v.9 no.2
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• pp.142-148
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• 2009

Anxiety disorders are one of the serious problems which need proper therapy devoid of side effects of presently available medicines. The present study evaluates the anxiolytic and sedative activity of leaf galls of Piper nigrum Linn. in Swiss Albino mice. The pet. ether, chloroform, ethyl acetate and ethanol extracts of leaf galls of Piper nigrum Linn were obtained by continuous soxhlet extraction. The prepared extracts were found to be safe up to 2000 mg/kg body weight of mice in the acute toxicity study. Each extract was assessed for anxiolytic activity in Swiss Albino mice by elevated plus Maze, open field test, rota rod test and phenobarbitone induced sleeping time test. In the Elevated Plus Maze test, the pet.ether extract and chloroform extract at a dose of 50 mg/kg b.w. orally, significantly (P < 0.01) increased the number of entries and time spent in open arm comparable with standard diazepam at the dose of 10 mg/kg. b.w. p.o. In the open field test, pet. ether extract (50 mg/kg b.w. p.o.) showed significant increase (P < 0.01) in ambulation and activity in the center. Chloroform extract (50 mg/kg b.w p.o.) was significant (P < 0.05) for both ambulation and center activity. Pet. ether extract (50 mg/kg b.w. p.o) also showed significant activity (P < 0.01) in rota rod test. All the results are comparable with standard diazepam at the dose of 1 mg /kg b.w, p.o. Moreover all the extracts showed significant (P < 0.01) increase in the phenobarbitone induced sleeping time among which pet.ether showed more prominent activity (36%) comparable with control. The results revealed that, the active pet.ether extract and chloroform extract of leaf galls of Piper nigrum Linn is worthwhile to develop the bioactive principle for anxiolytic activity.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.5
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• pp.1768-1789
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• 2015

The maximal signal-to-interference-plus-noise ratio (Max-SINR) algorithm for interference alignment (IA) has received considerable attention for its high sum rate achievement in the multiple-input multiple-output (MIMO) interference channel. However, its complexity may increase dramatically when the number of users approaches the IA feasibility bound, and the number of iterations and computational time may become unacceptable. In this paper, we study the properties of the Max-SINR algorithm thoroughly by presenting theoretical insight into the algorithm and by providing the potential of reducing the overall computational cost. Furthermore, a novel IA algorithm based on the principle direction search is proposed, which can converge more rapidly than the conventional Max-SINR method. In the proposed algorithm, it searches along the principle direction, which is found to approximately point to the convergence values, and can approach the convergence solutions rapidly. In addition, the closed-form solution of the optimal step size can be formulated in the sense of minimal interference leakage. Simulation results demonstrate that the proposed algorithm outperforms the conventional minimal interference leakage and Max-SINR algorithms in terms of the convergence rate while guaranteeing the high throughput of IA networks.

• 전기의세계
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• v.25 no.5
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• pp.70-74
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• 1976

In this paper, the problem of controlling deterministic contimuous linear system with a slightly modified quadratic performance criteria is studied. When the number of out put variables is much lesser then that of state variables, either the controller becomes complex or the performance measure becomes much higher with only output feedback. So the design philosphy treated in this paper lies in finding a compromising point between the controller complexity and the performance measure. thd controller is composed of stasic plus dynamic compensator with order equal to the mtmber of output variables. Several unknowns are unknown parameters are bundled into one, and using Pontryagin's minimum principle, conditions and formula for optimum control are induced which are different from that of Kalman optimal regulator.

• Archives of Plastic Surgery
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• v.41 no.1
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• pp.19-28
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• 2014

Recently, in Korea, the septal extension graft from the septum or rib has become a common method of correcting a small or short nose. The success rate of this method has led to the blind faith that it provides superior tip projection and definition, and to the failure to notice its weaknesses. Even if there is a sufficient amount of cartilage, improper separation or fixation might waste the cartilage, resulting in an inefficient operation. Appropriate resection and effective fixation are essential factors for economical rhinoplasty. The septal extension graft is a remarkable procedure since it can control the nasal tip bidirectionally and three dimensionally. Nevertheless, it has a serious drawback since resection is responsible for septal weakness. Safe resection and firm reconstruction of the framework should be carried out. Operating on the basis of the principle of "safe harvest" and rebuilding the structures is important. Further, it is important to learn several techniques to manage septal weakness, insufficient cartilage quantity, and failure of the rigid frame during the surgery.

• International Journal of Automotive Technology
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• v.7 no.2
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• pp.173-177
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• 2006

A noise transfer function(NTF) is the frequency response function between an input force applied to an exterior point of a vehicle body and the resultant interior sound pressure usually measured at the driver's ear position. It represents the measure of noise sensitivity for the output force transmitted to the joints between the body and chassis. The principle of vibro-acoustic reciprocity is often utilized in the measurement of NTF. One difficulty in using the volume source is that most of the previously proposed methods require the knowledge of the volume velocity of the acoustic source in advance. A new method proposed in the present work does not require any calculation related with the volume velocity of the acoustic source, but still yields even more accurate results both in the amplitude and phase of the NTF. In the present work, the new method is applied to obtain NTF data for a midsize sedan.

• Smart Structures and Systems
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• v.23 no.4
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• pp.319-327
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• 2019

Continuous rotating SMA actuators require motion conversion mechanisms, so their structure is relatively complex and difficult to realize the miniaturization. Here, a new type of continuous rotating actuator driven by SMA is proposed. It combines the movable tooth drive with SMA drive. The structure and working principle of the integrated movable tooth drive system is introduced. The equations of temperature, stress and strain of memory alloy wires, and the output torque of drive system are given. Using these equations, the temperature, the output forces of the SMA wires, and output torque of the drive system are studied. Results show that the compact drive system could give large output torque. To obtain large output torque plus small fluctuation, large eccentricity and small diameter of the SMA wire should be taken. Combined application of ventilation cooling and high current can increase the rotary speed of the drive system.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.473-480
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• 2004

Recently, they are interested in the relation between night's vehicle accidents of drivers and the dynamic visual acuity at home and aboard. So, in this research, we tried to design an optical system of the inspection equipment to measure the dynamic visual acuity. A optotype standard did to Landolt's ring with 45mm of diameter and 9mm of gap to maintain the visual acuity of 1.0 in the 30m distance. An optical structure of the inspection equipment was composed of the sequence of an observer, a plus refraction lens system, a minus refraction lens system, and an optotype that was arranged to have characteristics that the size of the first virtual image of the optotype made by the minus refraction lens system grows bigger gradually according to the optotype movement to near distance from far distance, and also the first virtual image moves to the principle plane from the focal point of the plus refraction lens system as the size of the first virtual image arranged to the inside of focal distance of plus refraction lens system grows bigger gradually. As doing these processes, we completed the optical system of which characteristic is that the position of the final second virtual image moves to 3m from 50m as the size of the second virtual image made by the plus refraction lens system maintains to be regular.