• KIEE International Transactions on Power Engineering
• /
• v.12A no.1
• /
• pp.6-14
• /
• 2002

In this paper, an EMM(Equivalent Mechanical Model) Is developed to explain the voltage collapse mechanism by reflecting the effects of reactive powers. The proposed EMM exactly represents the voltage instability mechanism described by the system equations. By the use of the EMM model, the voltage collapse mechanism has been illustrated by showing the exactness of the results. The stable region has been investigated with a reactive-power-controlled two-bus system, which shows that special alerts are required when the system operates with leading power factor. It is also discussed a system transform technique to eliminate the resistance component of the Thevenin equivalent impedance for practical applications. Finally, the results adopting the proposed method fur sample systems which were transformed are listed

• Journal of the Semiconductor & Display Technology
• /
• v.17 no.2
• /
• pp.26-31
• /
• 2018

In this paper, surface defects and typical illumination mechanisms for steel plates are analyzed, and then optimum illumination mechanism is selected using discrete wavelet transform (DWT) synthetic images and discriminant measure (DM). The DWT synthetic images are generated using component images decomposed by Haar wavelet transform filter. The best synthetic image according to surface defects is determined using signal to noise ratio (SNR). The optimum illumination mechanism is selected by applying discriminant measure (DM) to the best synthetic images. The DM is applied using the tenengrad-euclidian function. The DM is evaluated as the degree of contrast using the defect boundary information. The performance of the optimum illumination mechanism is verified by quantitative data and intuitive image looks.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.38 no.11
• /
• pp.1215-1220
• /
• 2014

Breaking time is an important performance indicator of a circuit breaker. Thus, the operating mechanism of the circuit breaker should be optimized for reducing the breaking time. The operating mechanism in a gas circuit breaker is made up of several latches. Specifically, the geometry and relative positions of latches influence the dynamic behaviors of the operating mechanism. In this study, a three-stage latch operating mechanism is analyzed on the basis of the verified multibody dynamics model constructed using the MSC.ADAMS program. The relative positions and lengths of latches are selected as design variables. The dominant design variables are selected by a design study. Optimization is performed using a genetic algorithm (GA). The study results demonstrate that the performance of the circuit breaker improves by about 22.5.

• Asian Oncology Nursing
• /
• v.3 no.2
• /
• pp.103-111
• /
• 2003

The purpose of this study was to identify the effect of imagery therapy on "coping mechanism and type C personality of the women with mastectomy. To achieve this purpose, 2 hours sessions of imagery therapy were given to the patients with breast cancer twice a week for 6 weeks. The period of data collection was from July, 7th to August, 12th 2002. The participants were 30 patients, 15 experimental group, 15 control group who were treated at the G University hospital in J City. This study was designed using a quasi-experimental approach with non-equivalent Pre test-Post test Design. The themes for the Imagery Therapy Program were composed of Leuner's(1969) 12 Imagery Themes: flower, green-field, stream, mountain, house, woods, significant figures, rose, lion, ideal self-image, cave and volcano. The data were analyzed with ${\chi}2-test$ and MANOVA using the SPSS program. The course of image change of the 12 imagery themes was analyzed by content analysis. The results of this study are as follows: First Hypothesis, 'The score of type C personality in the women with mastectomy who received imagery therapy will be significantly lower than that of the control group' was supported(p<.05). Second Hypothesis, 'The score of coping mechanism' in the women with mastectomy who received imagery therapy will be significantly higher than that of the control group' was rejected. In conclusion, imagery therapy is suggested as an effective nursing intervention to change type C personality of the women with mastectomy, but not effective to improve coping mechanism. Therefore, the program for the women with mastectomy should be developed to change their coping mechanism, method of problem solving and Quality of life.

• Journal of Aerospace System Engineering
• /
• v.12 no.5
• /
• pp.69-75
• /
• 2018

In this study, we proposed a nylon wire cutting-type solar panel separation mechanism for CubeSat applications using spring-loaded pogo-pins, which has been widely used as temporary electrical interface between two separate electronics. The mechanism proposed in this study has great advantages of higher holding capability, ability to constrain along in-plane and out-of-plane directions of solar panels, simplicity in tightening of nylon wire and synchronous separation of multiple panels. In addition, the pogo-pins used for the proposed mechanism act as electrical power interface, separation status switch and separation spring. In this study, the functionality of the proposed mechanism was validated through the separation tests with various number of nylon wire windings.

• Environmental and Resource Economics Review
• /
• v.30 no.1
• /
• pp.107-128
• /
• 2021

It has been recognized that implementing the marginal price mechanism to CBP is not acceptable due to the lack of revenue of the marginal generators. This study shows that it is not the problem of marginal price mechanism but the structural problems originated by the suspension of restructuring, the technical limits of RSC program and inaccuracy of the generation cost estimation method. This study explains the method to calculate the cost function in operating modes of the CC generators and proposes the modeling for the CC generators in RSC program. To implementing the cost function in operating modes could give an opportunity to change the price setting mechanism from average to marginal cost. The price setting mechanism based on the marginal cost will be one of the main points to provide the right price signals and to introduce a real-time and A/S markets to prepare the energy transition era.

• Journal of Industrial Convergence
• /
• v.21 no.3
• /
• pp.57-64
• /
• 2023

As the technology advances and convergence progresses, companies are increasingly interested in the appropriability mechanism. Therefore in this study tried to understand the effectiveness of the appropriability mechanism of domestic IT companies. To this end, 7 appropriability mechanisms were finally derived and empirically analyzed from a review of previous studies and experts. As a result of the analysis, the importance of lead time advantage, patent, secrecy, complementary sales and service, design registered, complementary manufacturing, and learning curve effect was shown in the order of SW companies. HW companies, the importance of patent, secrecy, lead time advantage, design registered, complementary sales and service, learning curve effect, and complementary manufacturing were shown in the order of importance. Also patent, secrecy, and lead time advantage was selected as important factors. The results of in this study are expected to be used as useful guidelines on establishing an appropriability mechanism strategy in companies.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.10
• /
• pp.3253-3257
• /
• 2012

Second-order rate constants for the reactions of phenyl Y-substituted-phenyl carbonates 5a-g with Z-substituted-phenoxides ($k_{Z-PhO^-}$) have been measured spectrophotometrically in 80 mol % $H_2O$/20 mol % DMSO at $25.0{\pm}0.1^{\circ}C$. 4-Nitrophenyl phenyl carbonate (5e) is up to 235 times more reactive than 4-nitrophenyl benzoate (4e). The Br$\o$nsted-type plot for the reactions of 5e with Z-substituted-phenoxides is linear with ${\beta}_{nuc}=0.54$, which is typical for reactions reported previously to proceed through a concerted mechanism. Hammett plots correlated with ${\sigma}^o$ and ${\sigma}^-$ constants for the reactions of 5a-f with 4-chlorophenoxide exhibit highly scattered points. In contrast, the Yukawa-Tsuno plot results in an excellent linear correlation with ${\rho}_Y=1.51$ and r = 0.52, indicating that the leaving-group departure occurs at the rate-determining step (RDS). A stepwise mechanism, in which leaving-group departure occurs at RDS, has been excluded since the incoming 4-$ClPhO^-$ is more basic and a poorer nucleofuge than the leaving Y-substituted-phenoxides. Thus, the reaction has been concluded to proceed through a concerted mechanism. Our study has shown that the modification of the nonleaving group from benzoyl to phenyloxycarbonyl causes a change in the reaction mechanism (i.e., from a stepwise mechanism to a concerted pathway) as well as an increase in the reactivity.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.41 no.9
• /
• pp.720-725
• /
• 2013

Nylon wire cutting method by nichrome wire is generally applicable for cube satellite applications due to its advantages of simplicity. However, the system complexity is not avoidable to apply it on the cube satellite with multi-deployable structures. A lower constraint force of the mechanism is also one of the disadvantages of the mechanism. In this study, we proposed a preliminary structure design of cube satellite with the separation mechanism which is applicable for holding and release of the multi-deployable structures. The effectiveness of the mechanism design was verified through function test of EM mechanism. The structure analysis results showed that the structure design proposed in this study is feasible.

• The Journal of Korean Medicine
• /
• v.24 no.3
• /
• pp.108-117
• /
• 2003

Objective : The central opioid mechanism of acupuncture analgesia has been fairly well documented in acute behavioral experiments, but little electrophysiological study has been performed on the peripheral mechanism and subtypes of opioid receptors responsible for acupuncture-induced antinociception in chronic animal models. In the present electrophysiological experiment, we studied the peripheral mechanism and opioid receptor subtypes which Were implicated in electroacupuncture-induced antinociception in the rat with chronic inflammatory and neurogenic pain. Methods : In the rat with complete Freund's adjuvant-induced inflammation and spinal nerve injury, dorsal horn cell responses to afferent C fiber stimulation were recorded before and after electroacupuncture (EA) stimulation applied to the contralateral Zusanli point for 30 minutes. Also studied Were the effects of specific opioid receptor antagonists and naloxone methiodide, which can not cross the blood-brain barrier, on EA-induced inhibitory action. Results : EA-induced inhibitory action was significantly attenuated by naloxone methiodide, suggesting that EA-induced inhibition was mediated through peripheral mechanism. Pretreatment, but not posttreatment of naltrexone and spinal application significantly blocked EA-induced inhibitory actions. In inflammatory and neurogenic pain models, ${\mu}-$ and ${\delta}-opioid$ receptor antagonists (${\beta}-funaltrexamine$ & naltrindole) significantly reduced EA-induced inhibitory action, but ${\kappa}-opioid$ receptor antagonist had weak inhibitory effect on EA-induced antinociception. Conclusion : These results suggest that 2Hz EA-stimulation induced antinoeiceptive action is mediated through peripheral as well as central mechanism, and mainly through ${\mu}-$ and ${\delta}-opioid$ receptors.