• Journal of the Korean Society for Heat Treatment
• /
• v.17 no.3
• /
• pp.139-145
• /
• 2004

Equal channel angular pressing (ECAP) technique had been adapted to the Mg alloy (AZ31) for achieving effective grain refinement through severe deformation. The average grain size of $2.5{\mu}m$ could be obtained after 4 passes. The stability of the ECAPed structure at elevated temperatures was examined by annealing the ECAPed materials over a wide range of temperature between 473 and 748 K. The average activation energy, Q, for static grain growth of 1, 2 and 3 passes was 33.7 kJ/mole (=0.25QL, activation for lattice diffusion). The abnormally low Q value in the lower temperature range may indicate that grain growth occurs in the unrecrystallized microstructure where non-equilibrium grain boundaries containing a large number of extrinsic dislocations exist. The yield stresses of the ECAPed alloys decreased whereas the elongations increased after the ECAP process. These results should be related to the modification of texture for easier slip on basal plane.

• Journal of the Korea Society of Computer and Information
• /
• v.10 no.4 s.36
• /
• pp.191-201
• /
• 2005

In this paper, we propose a method to calculate camera motion parameter, which is based on efficient invariant features irrelevant to the camera veiwpoint. As feature information in previous research is variant to camera viewpoint. information content is increased, therefore, extraction of accurate features is difficult. LM(Levenberg-Marquardt) method for camera extrinsic parameter converges on the goat value exactly, but it has also drawback to take long time because of minimization process by small step size. Therefore, in this paper, we propose the extracting method of invariant features to camera viewpoint and two-stage calculation method of camera motion parameter which enhances accuracy and convergent degree by using camera motion parameter by 2D homography to the initial value of LM method. The proposed method are composed of features extraction stage, matching stage and calculation stage of motion parameter. In the experiments, we compare and analyse the proposed method with existing methods by using various indoor images to demonstrate the superiority of the proposed algorithm.

• Journal of Digital Convergence
• /
• v.19 no.6
• /
• pp.113-132
• /
• 2021

This study is a new evaluation using the Arrhenius equation, which is known as the chemical reaction rate estimation equation, to evaluate the intrinsic and extrinsic value elements of patents as a model. The performance of the evaluation model was superior to the SVM, Logistic reg. and ANN models that were used as patent evaluation models in prior studies. In addition, there was a strong correlation between the predicted lifespan of the patent and the actual lifespan of the patent. These evaluation models may be used for evaluation purposes only, or if an evaluation is required, including a commercialization entity or technical characteristics.

• Journal of Sensor Science and Technology
• /
• v.9 no.2
• /
• pp.96-105
• /
• 2000

Fiber optic TR-EFPI(total reflected extrtinsic Fabry-Perot interferometric) sensor was developed to measure the strain of structures, such as building, bridge, aircraft, etc. It has been difficult to distinguish the increase and decrease of the strain from the conventional fiber optic EFPI sensor because their signals only have a sinusoidal wave pattern related to the change of strain. Also, the absolute strain could not be measured by the simple fiber optic EFPI sensor. In this study, in order to measure the magnitude of strain with the direction of strain, the fiber optic sensor was simply constructed with the total reflected EFPI sensor probe. This probe was manufactured with a single mode fiber and a mirror coated fiber in a silica glass capillary tube. The output signal of this fiber optic TR-EFPT sensor can give the information about the magnitude and the direction of strain. The loading-unloading test was performed by the universal testing machine with alluminum beam specimen to compare the strain from fiber optic TR-EFPI sensor with the value from electrical strain gauge. In the result of this experiment. the strain from fiber optic TR-EFPI sensor had a good agreement with the values from the electrical strain gauge.

• The korean journal of orthodontics
• /
• v.36 no.6
• /
• pp.442-450
• /
• 2006

Objective: Many factors are considered when a patient chooses the type of dental institution they wish to receive treatment from. Numerous studies have been conducted regarding this issue. However, more research is needed in analyzing the patient's psychological aspects when he/she decides to choose the dental institution they wish to receive treatment from. Methods: A locus of control test was utilized to analyze the psychological aspects in orthodontic patients of a university dental hospital and a private dental clinic. The locus of control test is known to be useful in predicting a human being's behavior. Both intrinsic and extrinsic locus of control tests were carried out in 934 orthodontic patients attending Seoul National University Dental Hospital and 1466 orthodontic patients from a private dental clinic. Results: The orthodontic patients at the university dental hospital showed a stronger extrinsic locus of control compared with those from the private dental clinic. Conclusion: The orthodontic patients at the university dental hospital value the doctor as the authority figure and the treatment quality more than those at the private dental clinic.

• Journal of vocational education research
• /
• v.37 no.3
• /
• pp.113-131
• /
• 2018

The purpose of this study is to explore various factors during the career development period affecting the formation of the perspective on work of young workers after they graduated from high school, and to analyze the influence of each factor. The panel data of the Korean Education Longitudinal Study 2005 was used for the study. Specifically, the data on the 303 employees in the 7th year(2011) of their employment was used. First, perspective of young workers on work was affected by social self (self-awareness-related variables), educational background of their father(family background-related variables), and intrinsic and extrinsic learning motivation(learning motivation-related variables) formed during the career development period. However, extrinsic learning motivation had a passive and negative effect on motivation and giving value to work. Second, the variables related to self-awareness in the career development period and the variables related to the family background were found to have a causal relationship with the formation of young workers' perspective on work. This study is significant in that the learning motives formed during the career development period are found to be very meaningful and important variables for the formation of young workers' perspective on work.

• Tuberculosis and Respiratory Diseases
• /
• v.43 no.4
• /
• pp.651-656
• /
• 1996

We have experienced a case of sarcoidosis appearing asymmetrical diffuse interstitial lung lesions with multiple lymphadenopathy. This patient was a 57 year-old female who had been in good health until 2 months ago. At that time she noted the onset of an exertional dyspnea and weakness. Pulmonary function tests showed moderate obstructive pattern with mild decreased DLco. In the chest CT, multiple lymphadenopathy with small nodular lesions are scattered, and the impression was a metastatic lymph nodes with lymphangitic carcinomatosis. In bronchofiberscopy, we noted luminal narrowing by extrinsic compression in the right middle and lower lobe bronchi. And microscopic examination of by bronchofiberscopic biopsy showed chronic inflammation. Thus we performed subcarinal and tight supraclaviclar lymph nodes aspiration biopsy cytology, and that revealed class 0 and class 1, respectively. Finally, we performed an excisional biopsy for the right scalene lymph node, which revealed the specimen as a noncaseating granuloma. The angiotensin convecting enzyme level was overt two folds compared to normal value. And the patient had negative PPD skin test and hyperglobulinemia. After 18 weeks treatment with prednisone, the signs and symptoms which the patient clad suffered from, disappeared.

• Journal of the Korean Society of Earth Science Education
• /
• v.11 no.1
• /
• pp.55-62
• /
• 2018

The purpose of this study was to examine the pre-service elementary teachers' views on the necessity of science learning. The eighty five student teachers in their second year of studies were participated in this study. The participants freely wrote their thoughts on a question'Why should students learn science?' The results of the study are as follows: (1) The participants' responses were very diverse, so their responses contained almost all kind of values or arguments about the science learning suggested by researchers, and there was no difference in their response ratio between views of focusing on intrinsic values and views of focusing on extrinsic values; (2) About 30% of the participants had the biased conceptions on the necessity of science learning and they would be likely to explain their biased conceptions to their future students. The educational implications and the suggestions for further studies are also presented in this paper.

• The Journal of the Korea Contents Association
• /
• v.20 no.7
• /
• pp.417-428
• /
• 2020

Augmented reality(AR) service as one of the representative technologies in the era of the 4th industrial revolution has gotten people's increasing attention. At this time, this study aimed to examine the determinants affecting service satisfaction of the AR-based camera application service by focusing on Naver's service. Several factors that might have influences on satisfaction of the AR-based camera application service were conceived based on the previous literature. And it was tested whether they had influences on satisfaction of the AR-based camera application service or not empirically. The responses of a sample of 312 people who had experienced using Naver's service were collected by means of an online survey and they were analyzed employing a hierarchical regression analysis. The results of this research indicated that gender as one of demographic variable, perceived interactivity, aesthetic value, trend following motivation as an extrinsic motivation and playfulness as an intrinsic motivation have significant influences on the service satisfaction of the AR-based camera application service. The results in this study have meanings since they can be used as references for AR service providers to develop more satisfactory AR services.

• Proceedings of the IEEK Conference
• /
• 2003.07b
• /
• pp.771-774
• /
• 2003

Passivation Ledge's device is taken possession on one-side to the Emitter in this Paper. contact used in this paper Pt as Passivation Ledge of device to use Schottky Diode which has leitmotif, It is accomplished Current Modulation that we wish to do purpose using this device. Space Charge acts as single device which is becoming Passivation to know this phenomenon. This device becomes floating as well as Punched-through. V$_{L}$ (Voltage for Ledge) = - 0.5V ~ 0.5V variable values , PD(Partially Depleted ; Λ＞0), as seeing FD(Fully Depleted ; A = 0) maximum electric current gains and Gummel Plot of I-V characteristics (V$_{L}$ = 0.1/ V$_{L}$ = -0.1 ). Becomming Degradation under more than V$_{L}$ = 0.1 , less than V$_{L}$ =-0.05 and Maximum Gain(=98.617076 A/A) value in the condition V$_{L}$ = 0.1. A Change of Modulation is electric current gains by using Schottky Diode and Extrinsic Base PN Diode of Passivation Ledge to Emitter Depletion Layer in HBT of Gummel-Poon I-V characteristics and the RF wide-band electric current gains change the Modulation of CE(Common-Emitter) amplifier description, and it had accomplished Current Gain Modulation by Ledge Bias that change in high frequency and wide bands. wide bands.s.