• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권11호
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• pp.512-515
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• 2003

This paper is to investigate how partial discharge pulse signal can flow in 6.6㎸ motor stator windings. Pulse propagation is experimentally analyzed in stator windings using a variety of frequency-domain techniques. The experiments were performed on two stator windings in the laboratory. Spectrum analyzer(9KHz to 3㎓) with tracking generator(100kHz to 3㎓) was used. Sweep time of the tracking generator was looms. The frequency spectrum of the response signal was detected by active FET probe(1㎓). The active FET probe has a flat amplitude response up to 1㎓ without high frequency attenuation. The stator winding acts as a low-pass filter below 600KHz, the high-frequency components being highly declined. The resonance peaks show about 1.1MHz and 2MHz in low frequency of No. 1 and No. 2 stator windings, respectively. This low-frequency range indicates that attenuation is low. The peaks of partial discharge magnitude show about 900MHz, 1.6MHz in No. 1 stator winding and about 800KHz, 1.4MHz in No. 2 stator winding.

• 통상정보연구
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• 제10권3호
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• pp.41-57
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• 2008

This research studies the effects of pre-show promotion, at-show promotion, and booth staff training on the image-building and relationship improvement performance of exhibitors. To this purpose, we relate each performance dimension to tactical variables such as pre show promotion, at-show promotion, and booth staff training through related literature review and conduct empirical study on their relationship. The results of this study are as follows: (1) Pre-show promotion and booth staff training have positive influence on image-building and relationship improvement performance. (2) But, at-show promotion has no effect on image-building performance, and has a negative effect on relationship improvement performance. (3) Especially, pre-show promotion has the greatest effect on relationship improvement performance, and booth staff training has the greatest effect on image-building improvement.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제29회 KOSCI SYMPOSIUM 논문집
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• pp.169-174
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• 2004

The NOx emission characteristics with oxygen enrichment in nonpremixed counterflow and coflow jet flame of $CH_4$ fuel have been investigated numerically. A small amount of nitrogen is included in oxygen-enriched combustion, in order to consider the inevitable $N_2$ contamination by air infiltration. The results show that the initial increase of NO with increasing oxygen enrichment is due to increasing temperature and residence time, while its subsequent decrease above 75% oxygen is due to decreasing the consumption rate of nitrogen. When oxygen addition exceeds 30%, Thermal NO gradually becomes the dominant production pathway and Prompt NO becomes negative pathway for net NO production rate. It is also seen that Thermal NO plays an important role in NO reduction when strain rate increase in oxygen-enriched combustion. Finally, the results of EINOx with oxygen enrichment in coflow jet flame show the similar profile with those of conterflow flame. It is confirmed that, with leakage of 1% nitrogen in the oxidizer stream, the corresponding EINOx is eight times of that emitted from regular $CH_4$/Air flame.

• 영어어문교육
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• 제11권1호
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• pp.179-202
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• 2005

The purpose of this study is to examine whether the teacher feedback (TF) group and the peer feedback (PF) group exhibit significant differences in their English writing abilities and attitudes toward English writing. The subjects of this study are eighty-three college first-year students enrolled in a college English reading class. The subjects' first and final writing samples are used to measure the improvement of English writing abilities and a set of pretest and posttest questionnaires is administered in order to find their attitudes. The qualitative and quantitative analyses of the data collected show the following results. First, the two groups show no significant difference in their holistic scores. Neither do the two groups display any significantly different development in their analytic scores. Second, the two groups show no significant differences in attitude factors but writing confidence. These findings suggest that peer feedback can be used to encourage EFL college students to develop their writing abilities.

• 대한화학회지
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• 제10권1호
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• pp.1-3
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• 1966

The organic yields (i.e. fraction of nuclear events resulting in organic compound formation) of the radioative neutron capture reactions of halogens in purified bromobenzene have been determined varying extraction time, at $100^{\circ}C$ for thermal effect, varying irradiation time, varying neutron flux and with additional U. V. irradiation. Among the important results are; (1) The organic yields show no remarkable fluctuations with time following neutron irradiation; (2) The organic yields show no change with thermal energy; (3) The organic yields of degassed samples are same in different length of irradiation time whereas the yields of the samples in open air appear to increase with increasing time of irradiation (4) The organic yields increase remarkably with increased neutron flux; (5) The organic yields show a sharp increase by additional U. V. irradiation after neutron irradiation.

• 대한치과기공학회지
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• 제25권1호
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• pp.21-28
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• 2003

The purpose of this study was to process bio-active glass ceramic composite, reinforced with sapphire fibers, by hot press. Also to study the interface of the matrix and the sapphire fiber, and the mechanical properties. Glass raw materials melted in Pt crucible at 1300$^{\circ}C$ during 3.5 hours. The melt was crushed in ball mill and then crushed material, ground and sieved to $<40{\beta}{\mu}m$. Sapphire fibers cut (30mm) and aligned. Powder and fibers hot pressed. The micrographs show good bonding between the matrix and the fiber and no porosity in the glass matrix. This means ideal fracture phenomena. Glass is fractured before the fiber. This is indication of good fracture strength. EDXS showing aluminum rich phase and crystalline phase. Bright field image of the matrix showing crystalline phase. Also diffraction pattern of TEM showing the crystalline phase and more than one phase. Strength of the samples was determined by 3 point bend testing. Strength of the 10vol% sample was approximately 69MPa, while strength of the control sample is 35MPa. Conclusions through this study as follow: 1. Micrographs show no porosity in the glass matrix and the interface. 2. The interface between the fiber and the glass matrix show no gaps. 3. Fracture of the glass indicates characteristic fiber-matrix separation. 4. Presence of crystalline phase at high processing temperature. 5. Sapphire is compatible with bioactive glass.

• 한국정밀공학회지
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• 제14권11호
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• pp.34-41
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• 1997

This paper presents a technique to control a very flexible robot moving in a vertical plane. The flexible robot is modeled as an Euler-Bernoulli beam. Elastic deformation is approximated using the assmed modes method. A comparison function which satisfies all geometric and natural boundary conditions of a cantilever beam with an end mass is used as an assumed mode shape. Lagrange's equation is utilized for the development of a discretized model. A control algorithm is developed using a simple PID cnotrol tech- nique. The proportional, integral and deivative control gains are determined based on the dominant pole placement method and tuned to show no overshoot and no steady state error, and short settling time. The effectiveness of the developed control scheme is showed in the hub angular diaplacement control experiment. Three different end masses are uned in the experiment. The experimental results show that developed control algorithm is very effective showing little overshoot, no steady state error, and less than 2.5 second settl- ing time in case of having an end mass which is equivalent to 45% of the manipulator mass. Also the experimental results show that the residual vibration fo the end point is effectively controlled.

• The Journal of Asian Finance, Economics and Business
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• 제9권5호
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• pp.1-9
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• 2022

The study examines stock prices (LOGKSE) and exchange rate (LOGPK)-Pakistani Rupee vis-à-vis US Dollar- interactions in Pakistan. This study employs a multivariate VAR-GARCH model using monthly data from January 2012 to October 2020. The results of the Johansen cointegration test show that there is no relationship between Foreign Exchange Market and Stock Market in the long run. In the short-run, stock exchange returns are affected slightly negatively by the changes in the foreign exchange market, but the foreign exchange market does not seem to be affected by the ups and downs of the stock exchange. The VAR model and Granger Causality show that both markets are strongly influenced by their own lagged values rather than by the lagged values of one another and show weak or no correlation between the two markets. Volatility persistence is observed in both the stock and foreign exchange markets, implying that shocks and past period volatility are major drivers of future volatility in both markets. Thus greater uncertainties today will induce panic and consequently generate higher volatility in the future period. This phenomenon has been observed many times on Pakistan Stock Exchange especially. The results have important implications for local international investors in portfolio diversification decisions and risk hedging strategies.

• 무역상무연구
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• 제52권
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• pp.73-96
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• 2011

The economic globalization has contributed the easy interchangeability of goods and services worldwide and consequently this tendency gives a great impetus to the expansion of exhibition Nowadays there is no dispute that the exhibition industry contains Export Marketing, Sales, Market Research and New product launching. This paper is trade show strategy use for export firms. Therefore, paper discusses theory of exhibition, character and utility. Moreover study to basic strategy of participate in Trade show Participate in Trade show strategies are several point. First, Trade show goal accord to firm's purpose. Second, Devise of trade show competition strategy. Third, Support of government and relevant agency. forth, Trade Show insurance.

• 음성과학
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• 제11권3호
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• pp.111-128
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• 2004

In English, a focused word with new information receives a pitch accent. This paper examines how English native speakers and Korean speakers produce and perceive focus in English yes-no questions. The production experiments show that native speakers realize an appropriate intonation of yes-no questions, in which a focused word has a low pitch accent followed by a high phrasal accent and a high boundary tone. However, Korean speakers usually give a high tone to a focused word. In a like manner, the perception experiments show that English native speakers judge a word with a low tone to be focused, while Korean speakers have difficulty in comprehending a focused word realized as a low tone. And it is found that Korean speakers tend to perceive low tones on sentence initial and final focused words better than those on sentence medial focused words, and they often perceive a word with a relatively high fundamental frequency or a sharp rise of fundamental frequency as a focused word. This paper shows that Korean speakers have trouble to produce and perceive an appropriate tonal pattern of a focused yes-no question, and that can cause confusion in a conversation with native speakers.