• Journal of Pharmaceutical Investigation
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• v.40 no.5
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• pp.263-267
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• 2010

Nanoemulsions have been widely investigated for many years because of their attractive and unique characteristics. Nanoemulsions are composed of oil, surfactant, co-surfactant and water. Especially, cosurfactant plays a critical role in formation of nanoemulsions. In pharmaceutical area, a pre-concentrate form of nanoemulsions which is known as self-nanoemulsifying drug delivery systems (SNEDDS) was available for some water-insoluble drugs. In this study, we investigated the functional behaviors of cosurfactant in design of SNEDDS and nanoemulsions. Cremophor RH 40$^{(R)}$, Propylene carbonate and medium chain triglyceride were selected for surfactant, cosurfactant and oil, respectively. Cyclosporine was employed as a drug. Phase diagrams showed the area of isotropic o/w region which forms o/w nanoemulsions was not significantly affected by the compositional ratio of cosurfactant. But, drug solubilization capacity, droplet size of nanoemulsions and drug release rate were greatly affected by the cosurfactant.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.301-301
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• 2011

We present theoretical investigations of the self-assembled growth of one-dimensional (1D) molecular lines directed across the dimer rows on the H-terminated Si(001) surface [1]. Based on density-functional theory calculations, a new growth mechanism of the 1D acetylacetone line is proposed [2], which involves the radical chain reaction initiated at two dangling-bond sites on one side of two adjacent Si dimers. It is also enabled that, if an H-free Si dimer were employed as the initial reaction site, a 1D acetylacetone line can grow along the dimer row. Our findings represent the first insight into the growth of 1D molecular lines not only across but also along the dimer rows on the H-terminated Si(001) surface.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.1987-1989
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• 1998

A single phase induction motor is predominant in fractional horsepower rating and is widely used in home and industrial equipment. For example, these motors provide the motive power to washing machines, fans, refrigerators, etc. In this paper has presented the design and implementation of a microcontroller software - based self - starting SPIM. The control algorithm used in the experimentation employed simple control strategies which enabled a single chip programmable microcontroller to execute both the self - starting and self - detecting control of SPIM with relatively simplified hardware.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1996.10a
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• pp.29-48
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• 1996

Previous studies on user training have largely focused on assessing models which describe the determinants of information technology usage or examined theeffects of training, on user satisfaction, productivity, performance and so on. Scant research efforts have been made, however, to examine those effects of training by using theoretical models. This study presented a conceptural model to predict intention to use information technology and conducted an experimentto understand how training for computer skill acquisition affects primary variables of the model. The data were obtained from 32 student subjects of an experimental group and 31 students of a control group, and the information technology employed for this study was a university's electronic mail system. The study results revealed that attitude toward usage and perceived behavioral control helped to predict user intentions ; outcome expectations were positively related to attitude toward usage ; and self-efficacy was positively related to perceived behavioral control. Thd hands-on training for the experimental group led to increases in perceived ease of use, self-efficacy and perceived behaviroal control. The changes in those variables suggest more causal effects of user training than other survey studies.

• Journal of the Korean Operations Research and Management Science Society
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• v.26 no.3
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• pp.1-20
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• 2001

The amount of financial information in sophisticated large data bases is huge and makes interfirm performance comparisons very difficult or at least very time consuming. The purpose of this paper is to investigate whether neural networks in the form of self-organizing maps (SOM) can be successfully employed to manage the complexity for competitive financial benchmarking. SOM is known to be very effective to visualize results by projecting multi-dimensional financial data into two-dimensional output space. Using the SOM, we overcome the problems of finding an appropriate underlying distribution and the functional form of data when structuring and analyzing a large data base, and show an efficient procedure of competitive financial benchmarking through clustering firms on two-dimensional visual space according to their respective financial competitiveness. For the empirical purpose, we analyze the data base of annual reports of 100 Korean listed companies over the years 1998, 1999, and 2000.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1211-1212
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• 2006

The electrophoretic deposition process of Ni nano-particles was employed for self-repairing of heat exchanger tubes. For electrophoretic deposition of Ni nano-particles on pitted Ni alloy specimen, a constant electric field of 100 V $cm^{-1}$ was applied to the specimen for 180 s in Ni-dispersed solution. It was found that as electrophoretic deposition proceeded, the size of the pit remarkably decreased due to the agglomeration of Ni nano-particles at the pit. This strongly suggests that the electrophoretic mobility of the charged particles is larger for the pit with a higher current value rather than outer surfaces with a lower current value.

• Journal of the Korean Institute of Telematics and Electronics
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• v.4 no.3
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• pp.28-33
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• 1967

The analysis of differential amplifier is simplified by the extention of bisection theorem. In order to reduce the thermal and porwor drifts, a self compensating circuit is employed. The optimum conditions of the self compensating circuit are: the base-emitter voltage of one transistor should be equal to the other's base-emitter voltage for basic self compensating circuit, the tempereature coefficients of base-emitter voltage of one transistor equal to the others for thermal compensation. By regarding the thermal and power drifts the experiments were performed were performed and the numerical results were consistent with the measured values.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.9
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• pp.76-87
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• 1992

A novel self-organizing fuzzy plus PD control algorithm is proposed, where the proposed controller consists of a typical fuzzy reasoning part and self organizing part in which both on-line and off-line algorithms are employed to modify the Look-Up Table(LUT) for the fuzzy control rules and to decide how much fuzzy rules are to be modifid after evaluating the control performance, respectively. And the fuzzy controller is replaced by a PD controller in a prespecified region nearby the set point for good settling actions, where gain parameters are determined by fuzzy rules based on the magnitude of error velocity at the instant when the output penetrates into the prespecified region. To show the effectiveness of the proposed controller, extensive computer simulation results as well as experimental results are illustrated for an inverted pendulum system.

• Journal of Families and Better Life
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• v.15 no.4
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• pp.253-268
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• 1997

the purpose of this study was to analyze the relationship between elderly's leissure participation and the type of leisure attitude and leisure constraints. The sample of this study consisted of 485 elderly over 55 years old living in Seoul Daejeon Jeonju and Daegu. Statistics employed for the analysis were frequencies means cross-tabs and multiple regression analysis. The results could be summarized as follows The types of leisure attitude and leisure constraints of elderly was affected by the age educational attaintment health status region total asset income pocket money family relationship locus of control and self-esteem. And educational attaintment health status region family relationship locus of control and self-esteem had effects on leisure participation level of elderly. These findings pointed that psychological factors such as family relation self-esteen and type of leisure attitude and leisure constraints were the variables explaining leisure activities of elderly.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.05b
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• pp.101-106
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• 2009

We study on the segregation reduction effect of Self-Leveling Color Mortar by using variable composition set of plasticizer and thickener, Naphthalene, melamine and polycarbonate-based dispersants were employed as plasticizers for examining on fluidity of mortar mixtures. For enhancement of mortar stability without loss of it's fluidity, two types of thickener were used such as polysaccharide(PS) and hydroxyethylcellulose(HEC). As a result, the most effective mortar was composed by feeding 0.519% of polycarbonate-based dispersant with 0.002587% of PS and 0.155844% of HEC on amount of basic mortar.