• Journal of Power Electronics
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• v.2 no.1
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• pp.55-66
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• 2002

A new on-line dead-time compensation method for a permanent magnet (PM) synchronous motor drive is proposed. Using a simple disturbance observer without any additional circuit and off-line experimental measurement, disturbance voltages in the synchronous reference dq frame caused by the dead time and non-ideal switching characteristics of power devices are estimated in an on-line manner and fed to voltage references in order to compensate the dead-time effects. The proposed method is applied to a PM synchronous motor drive system and implemented by using software of a digital signal processor (DSP) TMS320C31. Simulations and experiments are carried out for this system and the results well demonstrate the effectiveness of the proposed method.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11b
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• pp.423-429
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• 2000

The water conditioning experiments of brown rice were performed to verify the effect of brown rice conditioner and to decide the optimum operating variables for the conditioner. The initial moisture contents of 13-14%(wb) brown rice were used as experimental samples. The flow rate of brown rice passing through the conditioner was 2,940 kg/hr and water was supplied proportionally from 80 cc/min to 240 cc/min. The differences between expected and measured moisture contents were neglected except 0.25%(wb) of the maximum differences at 0.2920((cc/min)-water/(kg/min)'%-brown rice) of water supply rate. For the initial moisture contents of 13-14%(wb) brown rice, it was found that a proper water supply rate was 0.2415((cc/min)-water/(kg/min).%-brown rice) and the increments of whole rice was 2.3% compared to non conditioned ones. It was considered that the conditioning process did not influence the whiteness of milled rice because the whiteness differences between conditioned and non-conditioned milled rice were negligible.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.1
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• pp.26-39
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• 2021

This study investigated the characteristics of the watershed and pollutants in the Seonakdong River basin in the lower stream of the Nakdong River Water System, and evaluated the areas vulnerable to nonpoint pollution by subwatershed according to the TOPSIS(Technique for Order of Preference by Similarity to Ideal Solution) method. The selection method consists of selection of evaluation factors, calculation of weights and selection of areas vulnerable to non-point pollution through evaluation factors and weights. The entropy method was used as the weight calculation method and TOPSIS, a multi-criteria decision making(MCDM) method was used as the evaluation method. Indicator data were collected as of 2018, and national pollution source survey data and national statistics were used. Most of the vulnerable watersheds were highly urbanized had a large number of residents and were evaluated as having a large land area among industrial facilities and site area rate. Through this study, it is necessary to approach a variety of weighting methodologies to assess the vulnerability of non-point pollution with high reliability, and scientific analysis of the factors that affect non-point pollution sources and consideration of the effects are necessary.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.16 no.2
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• pp.158-164
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• 2005

Melody intonation therepy (MIT) is to improve the linguistic aspects of the verbal utterance for aphasic patients utilizing the intact right brain. It is applied to the aphasic patients with good comprehension, poor fluency, and little available speech are thought to be ideal candidates. The purpose of the study was to investigate the effects of Korean Melody intonation therapy (kMIT) in patients with non-fluent aphasia. Five male non-fluent aphasic patients were participated in this study. Average ages were 49.9 years old. Each therapy took 45-50minutes once a week for six months. Aphasic Screen lest (RISS) was used to assess language parameter such as Auditory comprehension, oral expression, reading, writing and calculation ability before and after kMIT. Mean of Length Utterance, verbal intelligibility and articulation disorder were assessed also. Computerized Speech Lab was used to assess the acoustic characteristics of aphasic patients before and after kMIT. The results are as follows : 1) Auditory comprehension, oral expression, reading, writing and calculation ability of the subjects increased after UH'. However, only oral expression showed significant difference (p<0.05). 2) Mean of Length Utterance of five patients generally increased after Un. 3) After kMIT, verbal intelligibility increased and showed significant difference (p<0.05). 4) Misarticulation rate generally decreased after m. 5) Voice Onset Time of the alveolar lenis /t/ and velar lenis /k/ gradually decreased after kMIT. 6) However, intonation pattern were increased gradually in yes'no question after kMIT.

• Journal of the Korean Society of Fashion and Beauty
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• v.1 no.1 s.1
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• pp.143-151
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• 2003

As korean women despised to transform their appearance into totally different shape, and they regarded to enhance a inherent beauty ideal beauty, korean traditional make-up culture was natural. But in modern society, make-up has been developing as one of the beauty industry and it means make-up involves more meanings than primitive period and needs to study its multi-dimensional connotation to understand in the culture. The purposes of this study were to find out what was represented in make-up ad and how it has been changed. The data of this study were collected from make-up advertisement printed in 'Hyang Jang' which is a periodical of amole pacific cosmetic industry from 1972-2001, and qualitatively analysed. As a results of content analysis were: The characteristics of non-verbal expression in make-up advertisements were different by the time. Generally person-appeal advertisements were more than product-appeal advertisements. And in the 1970s and early 1980s, person-appeal advertisements were appeal to the lifestyle, but after that person itself was appealed. And also after early 1980s, image-appeal advertisements were increased.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.4
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• pp.264-271
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• 2009

Characteristics of a counter flowing diffusion flame, which is formulated by an oppositely-injected methane-jet flow in a narrow channel of a uniform air flow. The location of the flame fronts and the flame lengths were compared by changing the flow rates of fuel. To distinguish the effects of the narrow channel on the diffusion flame, a numerical simulation for an ideal two-dimensional flame was conducted. Overall trends of the flame behavior were similar in both numerical and experimental results. With the increase of the ratio of jet velocity to air velocity flame front moved farther upstream. It is thought that the flow re-direction in the channel suppresses fuel momentum more significantly due to the higher temperature and increased viscosity of burned gas. Actual flames in a narrow channel suffer heat loss to the ambient and it has finite length of diffusion flame in contrast to the numerical results of infinite flame length. Thus a convective heat loss was additionally employed in numerical simulation and closer results were obtained. These results can be used as basic data in development of a small combustor of a nonpremixed flame.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1190-1195
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• 2005

Biomass burning is a source of greenhouse gases, carbon dioxide, methane, and nitrous oxide. Under the ideal conditions of complete combustion, the burning of biomass produces carbon dioxide and water vapor. Since complete combustion is not achieved under any conditions of biomass burning, other carbon species, including carbon monoxide, methane, non-methane hydrocarbons and particulate carbon are produced. In this study, we analyze the combustion characteristics of rice-husk, such as heat release rate, smoke production rate, the percentage variation of CO and $CO_2$, oxygen consumption rate, and mass loss under different heat fluxes (20, 50 and 70kW). As a result, at 20kW incomplete combustion is occurred so that the percentage of CO is high in initial burning and total smoke release is higher than the others. At 50kW and 70kW, the combustion behaviors is very similar except the variation of CO percentage.

• Journal of the Korean Society of Costume
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• v.58 no.2
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• pp.134-148
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• 2008

Methods of delivering products to consumers do not act as less important factor than creative activities to create new product designs. Mobilizing various psychological elements based on human instinct and desire, fashion industry presents a product as an object of envy, gaining viewers' attention. Here, the viewer does not simply take the product as an object to view, but also imagine transformation it will bring. The study of the cause and effects of the interaction, which is found in the relationship between "the viewer" and "what is viewed" is an important factor that needs to be identified in the phase of creation as well as in the aspect of delivery. The relationship between the perceiver and what is perceived features in designs, product advertisements, related articles, and fashion shows in modern fashion, serving as a medium that enables the humans, who must inevitably exist between the two poles such as mind and body, the subject and the object, the ego and non-ego, and the reality and an ideal, to communicate between the poles. Humans cannot do arbitrary acts or make arbitrary selections only as they access to foreign things through instinct, desire, or experienced perception, and they are sometimes positioned passive by things. In the background, as there are human dual characteristics in which they are expressed as the ego and another ego who exists inside of the ego, they not only view an object, but also become an object to be viewed. Many products in modern fashion, as the objects of reciprocal transposition, grow giving illusions to humans. Having a desire for such objects is human's instinct and normal act to keep the life balanced between the reality and an ideal, which is based on the activation of reality function. Furthermore, freely acting rather than ignoring or overcoming the desire may be the act of retrieving one's ownership to the ego.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.10 s.89
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• pp.983-995
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• 2004

This paper introduces a pre-compensation filter for compensating dispersive and resonant properties experienced along the usage of non-ideal wideband antennas in impulse communication systems. It has been well blown that the transmitted impulse signal becomes deformed because of dispersive and resonant characteristics. Accordingly, in spite of using ideal template signal at the correlator in coherent receiver, these impairments degrade overall performance attributed to low level of coherence. To overcome this problem this paper exploits a realization technique of pre-compensation filter purposely installed at transmitter whose stability is automatically guaranteed because it has an inversion form of minimum-phase ARMA (Auto-Regressive Moving Average) system. The performance of proposed scheme will be shown in results from computer simulations to verify its affirmative impact on impulse communication system with regarding several distinctively shaped antennas.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.5
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• pp.372-378
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• 2009

With the increase in capacity of photovoltaic generation systems, studies are being actively conducted to improve system efficiency. In order to develop the high performance photovoltaic power system it is required to understand the physical characteristics of the solar cell. However, solar cell models have a non-linear form with many parameters entangled and conventional methods suggested to extract the parameters of the solar cell model require some kind of assumptions, which accompanies the calculation errors, thereby lowering the accuracy of the model. Therefore, in this paper a novel method is proposed to calculate the ideality factor and reverse saturation current of the solar cell from the I-V curve measured and announced by solar cell manufacturers, derive the ideal I-V curve, and then extract the series and shunt resistances value from the difference between the ideal and measured I-V curve. Also, validity of the proposed method is demonstrated by calculating the correlation between I-V curve based on modeling parameters and I-V curve actually measured through least squares method.