• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.6
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• pp.525-537
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• 2001

In this paper a new space vector RPPWM(Random Position PWM) is proposed. In the propsed RPPWM each of three phase pulses is located randomly in each switching interval. Based on the Space vector modulation technique the duty ratio of the pulses is calculated Along with the randomization of the PWM pulses. we can obtain the effects of spread spectra of votlage, current as in the case of randomly changed switching frequency, To verify the validity of the proposed RPPWM simulation study was tried using Matlab/Simulink The main model described in Simulink block diagrams includes the space vector modulation block pulse position randomization block inverter block 3 phase induction motor block and so on By the simulation study, the harmonics of the output voltage and the current of inverter are predicted in different PWM methods- SVPWM, LLPWM proposed RPPWM.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.1
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• pp.35-43
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• 2016

PURPOSE: The purpose of this study was to investigate the effects of passive stretching exercises of the scalene muscles known as respiratory accessory muscles, on forced vital capacity. METHODS: Ten of the participants were randomly selected as an experiment group to perform passive stretching exercises on the scalene muscles. Ten additional students were selected randomly as a control group. The forced vital capacity was assessed by using a digital spirometer (Pony FX, COSMED Inc, Italy) both before and after the passive stretching exercises were performed. Subsequently, passive stretching exercises of the scalene muscles were performed in the experimental group. There were no interventions to the control group. RESULTS: As for the forced vital capacity (FVC), the experiment group showed significant increase in items of forced vital capacity (FVC), forced expiratory volume in 1 second ($FEV_1$), peak expiratory flow (PEF), forced expiratory volume in 1 second/vital capacity ($FEV_1/VC$), and maximal expiratory flow 75%(MEF 75%) after the scalenemuscles passive stretching exercises were performed. The control group, however, showed no change. CONCLUSION: This study demonstrated that passive stretching exercises of the scalene muscles could be helpful for forced vital capacity improvement.

• Journal of Advanced Navigation Technology
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• v.21 no.2
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• pp.187-192
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• 2017

The compensation characteristics of the distorted WDM channels compensated for by dispersion management (DM) and optical phase conjugation in the long-haul (50 fiber spans ${\times}80km$) transmission link with the randomly distributed single mode fiber (SMF) length and residual dispersion per spans (RDPS) are investigated as a function of the arrangement of SMF and dispersion compensating fiber (DCF) and the control position of net residual dispersion (NRD). It is confirmed that the compensation effect of the distorted WDM channels strongly depends on the arragement of SMF and DCF, rather than the control position of NRD.

• Korean Journal of Veterinary Research
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• v.42 no.4
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• pp.531-536
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• 2002

A total of 576 fatteners selected randomly from 6 Korean native goat farms in Chonnam area were examined for louse infestation from March 1997 to February 1998. The lice collected from the goats were identified. Four goat farms were selected and 20 goats were randomly chosen from each farm; blood samples were taken from the goats seasonally and examined hematologically and chemically. It was found that 495 out of 576 goats (85.9%) were infested with lice. The infestation rate in one of the 6 farms reached 92.9%. Two species of lice were identified; Linognathus sp. (sucking lice) and Bovicola sp. (biting lice). Goats infested with lice showed higher values in white blood cell, neutrophil and eosinophil counts than the goats not infested counterparts; same trend was seen with total protein, albumin and globulin concentrations. The results of this study indicate that louse infestation in the goat should be investigated extensively in view of the goat farming.

• The Korea Journal of Herbology
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• v.21 no.2
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• pp.175-180
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• 2006

Objectives : The difference of delayed luminescence-biophoton emission was investigated in Cervi Pantotrichum Cornu selected randomly. Cervi Pantotrichum Cornu was used as a tonic in Korean medicine. Methods : Randomly selected samples of Cervi Pantotrichum Cornu were radiated with 150 W metal halide lamp for 1 minute. After radiation, biophoton emissions of each sample were detected by electron multiplication(EM)-charge coupled device camera. The detected biophoton image was calculated with unit of counts per pixel. Results : The average biophoton emissions of delayed luminescence with EM ratio of ${\times}l50\;and\;{\times}250$ were distinguished significantly. The maximum biophoton emissions of delayed luminescence with EM ratio of ${\times}250$ were distinguished significantly. Conclusion : These results suggest that biophoton imaging of Cervi Pantotrichum Cornu could become the meaningful method for the study of differentiation and classification of Cervi Pantotrichum Cornu.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.16 no.3
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• pp.301-309
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• 2003

The non linear control algorithm with actuator saturation for a randomly excited oscillator has been widely explored and has shown promising results, but the probabilistic analysis of the algorithm has been rarely made due to its non-linear nature and the fact that the analytical solution of probability density function (PDF) for controlled responses does not exist. In this paper, a method for the probabilistic analysis on the non linear control algorithm with actuator saturation is proposed based on the equivalent non linear system method. Numerical examples are given to verify the approximation solution of PDF comparing to a statistically obtained PDF using a Gaussian white noise and a Kanai - Tagimi filtered Gaussian white noise.

• International journal of advanced smart convergence
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• v.6 no.1
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• pp.26-31
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• 2017

When mobile navigator device accesses data randomly, the cache memory performance is rapidly deteriorated due to low memory access locality. For instance, GPS (General Positioning System) of navigator program for automobiles or drones, that are currently in common use, uses data from 32 satellites and computes current position of a receiver. This computation of positioning is the major part of GPS which accounts more than 50% computation in the program. In this computation task, the satellite signals are received in real time and stored in buffer memories. At this task, since necessary data cannot be sequentially stored, the data is read and used at random. This data accessing patterns are generated randomly, thus, memory system performance is worse by low data locality. As a result, it is difficult to process data in real time due to low data localization. Improving the low memory access locality inherited on the algorithms of conventional communication applications requires a certain optimization technique to solve this problem. In this study, we try to do optimizations with data and memory to improve the locality problem. In experiment, we show that our case study can improve processing speed of core computation and improve our overall system performance by 14%.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.7
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• pp.387-398
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• 2002

In this paper, a new Three-Phase Lead-Lag Random Pulse Position PWM(LL-RPWM) scheme is proposed and implemented for decreasing audible acoustic noise of motor drives. In the proposed RPWM(Random PWM), each of three phase pulses is located randomly in each switching interval. Based on the space vector modulation technique, the duty ratio of the pulses is calculated. Along with the randomization of the PWM pulses, we can obtain the effects of spread spectra of voltage, current as in the case of randomly changed switching frequency. To verify the validity of the proposed LL-RPWM, the simulation and experimental study was tried. Along with the randomization PWM pulses, the space vector modulation is also executed in the C167 micro-controller. The simulation and experimental results show that the voltage and current harmonics are spread to a wide band area and that the audible acoustic noise is reduced by the proposed RPWM method.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2000.04a
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• pp.157-163
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• 2000

The application as the parts of an automobile, using the property of GMT-Sheet, is increasing. In order to exchange the parts of an automobile for GMT-Sheet, at first, the establishment and joining problem of exact joining strength must be determined. We have studied it using composites which is not same each other fiber oriented condition so as to determine joining strength and joining condition of GMT-Sheet. In this study, the result of experiment of forming condition concerned joining problem of GMT-Sheet is this ; joining efficiency of GMT-Sheet, increases as lap joint length L increases. Increase of compression ration cause decrease of joining efficiency after of GMT-Sheet, joining. In the viewpoint of recycling, randomly oriented composite of GMT-Sheet is desirable more than unidirectional oriented composite. We have better design the structure so as not occur to stress centralization on the joining part.

• Journal of Forest and Environmental Science
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• v.33 no.2
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• pp.91-96
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• 2017

Trees at farm are considered as one of the option to reduce poverty of smallholders by contributing to livelihood security and resilience to climate change. A perception based study was conducted to assess the cultural importance of tree species suitable for practicing agroforestry in randomly selected agroforestry-dominated villages in Alaknanda valley of Western Himalayas during 2015-16. Semi-structured questionnaire was used to collect primary data on the provisioning services of major agroforestry tree species in randomly surveyed 87 households. Based on cultural importance (CI) index value, the most suitable agroforestry tree species was Morus alba (3.32) followed by Celtis australis (3.22), Mangifera indica (3.01), Grewia optiva (2.79), Toona ciliata (2.22), Bauhinia variegata (2.08), Leucaena leucocephala (1.76) and Emblica officinalis (1.74). The preference of use has also been governed based on their indigenous knowledge. This study will also facilitate in evaluating the importance of provisioning services of agroforestry tree species in improving livelihood as well as facilitates smallholder's resilience to climate change in Western Himalayas.