• Investigative Magnetic Resonance Imaging
• /
• v.1 no.1
• /
• pp.148-153
• /
• 1997

Purpose: To evaluate the diagnostic role of a three-dimensional MR cholangiopancreatography (MRCP) over endoscopic retrograde cholangio-pancreatography (ERCP) in various extrah-epatic biliary disease. Materials and Methods: MRCP and ERCP were performed in 45 consecutive patients with suspected extrahepatic biliary diseases. MRCP was obtained using a reverse fast imaging with a steady-state free precession (reverse FISP: PSIF) sequence, and then images were reconstructed by standard MIP algorithm. The predictability of biliary dilatation and level of obstruction of MRCP was evaluated using ERCP as a gold standard. The accuracy distinguishing malignant from benign lesions, and overall diagnostic accuracy were compared between MRCP and ERCP. Results: The sensitivity, specificity and accuracy of MRCP in predicting biliary dilatation were 94.6%, 75.0% and 91.1%, respectively. The level of obstruction was accurate in 87.0% with MRCP. The sensitivity, specificity and accuracy of MRCP and ERCP in distinguishing malignant from benign lesions were 76.2%, 87.5% and 82.2% and 71.4%, 83.3% and 77.8%, respectively. The overall diagnostic accuracy was 60.0% with MRCP and 55.6% with ERCP. Conclusion: 3D MRCP shows a good diagnostic value compared to that of ERCP, and can replace a ERCP.

• Journal of the Korean earth science society
• /
• v.24 no.5
• /
• pp.440-448
• /
• 2003

We have performed 3-D geomagnetic induction Modeling considering with anomalous conductive structures to interpret the conductive anomaly proposed by previous studies on the Korean Peninsula. The results of modeling coincide well with the observed induction arrow. we confirm the fact that Imjin River Belt and Ogcheon Belt presumed in the model are reasonable. In the western-middle area of the peninsula (YIN, ICHN) the induction arrows seem to reflect the existence for the Imjin River Belt and the induction arrows in western-south area (HNS, CHY, DZN, MWN) is likely to reflect the effect of the Ogcheon Belt. The difference arrows, calculated by subtracting the sea effect from observed induction arrow in the western area of the peninsula at the period of 60-minutes, show little difference with the observed induction arrows. Especially, the difference arrows in YIN, ICHN also show a similar pattern to those at the periods longer than 10-minutes. These results strongly suggest that the Imjin River Belt and the Ogcheon Belt extend down to the deep part of the crust in spite of the limitation of our model.

• Journal of Digital Convergence
• /
• v.18 no.8
• /
• pp.201-215
• /
• 2020

We conducted the analysis using the data of the '2019 Korean Middle and Elderly Technology Acceptance Survey' to verify the comprehensive senior technology acceptance model. In this study, we examined the significant effect the relationship between behavioral intention to use the diital health devices and perceived usefulness, perceived ease of use, gerontechnology self-efficacy, gerontechnology anxiety, facilitating conditions, attitude to life and satisfaction through the structural equation. The results of the research model are as follows. First, the usefulness and ease of use had significant effects on intention to use. Second, the self-efficacy had significant effects on the intention to use. But they had negative effect. Third, perceived usefulness, self-efficacy and anxiety had significant effects on ease of use. Lastly, self-efficacy, facilitating conditions, attitude to life and satisfaction had significant effects on perceived usefulness. These findings highlight that verified the comprehensive senior technology acceptance model in Korea.

• Journal of the Korean School Mathematics Society
• /
• v.14 no.2
• /
• pp.123-142
• /
• 2011

Recently, a number of researches acknowledge the importance of 'reflection' and 'reflective teacher education,' and they highlight the implication of 'reflection' on the teacher's profession or the teacher education. The reflective thought is interpreted as a subject that should be taught or a sort of strategy that a teacher should learn, while the aspect is excluded that reflection is the interaction between the innate knowledge and the practice. As a result, the reflective teacher education programs that increase the level of reflection are developed and practiced, and the reflection is accepted as a tool for increasing teacher professionalism. Reflective teaching is en essential and basic element for the development of teacher knowledge. In particular, such teacher knowledge might be being gradually expanded by a teacher's self-assessment on reflection on his own instruction. For this reason, this study develops an assessment framework on instruction which is comprized of teacher knowledge and instructional process. To accomplish this, in this study, teacher knowledge is considered as a whole practice knowledge combined by subject matter knowledge, understanding of learners, teaching and learning methods and assessment, and instructional environment. Also, success on instruction in mathematics class might depend on the acquisition of teacher knowledge, instructional planning, instructional execution, and furthermore reflection on instruction. Especially, this study emphasizes that 'reflection on instruction', the most important step of instruction be reflected and examined by the teacher himself.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.54 no.2
• /
• pp.106-114
• /
• 2017

In this paper, we propose the method of designing an extended kalman filter in order to accurately measure the position of the spatial-phase system using sensor fusion. We use the quaternion as a state variable in expressing the attitude of an object. Then, the attitude of rigid body can be calculated from the accelerometer and magnetometer by applying the Gauss-Newton method. We estimate the changes of state by using the measurements obtained from the gyroscope, the quaternion, and the vision informations by ARVR_SDK. To increase the accuracy of estimation, we designed and implemented the extended kalman filter, which showed excellent ability to adjust and compensate the sensor error. As a result, we could experimentally demonstrate that the reliability of the attitude estimation value can be significantly increased.

• (The)Study of the Eastern Classic
• /
• no.71
• /
• pp.129-146
• /
• 2018

Choi Han-gi(崔漢綺)'s system of ideas is roughly called Ki-philosophy(氣哲學) because he presupposes ki(氣) as the foundational element as well as operational agent of the whole universe. Choi suggests that each extant entity should try to approximate itself to the greater cosmic operation and changes[大氣運化], thus achieving an harmonious unity with ilki(一氣), the ultimate originator as well as principle of the universe. In order to make this happen, he proposes that one execute chuchik(推測), a kind of empirical reasoning, which is gradually sharpened through expanding and accumulating his experiences of the outer world. Continuous practicing of chuchik(推測) helps one enlarge his conceptual, experiential and existential horizon much more greatly than could otherwise be possible. Such an expansion of the self naturally brings about one's ultimate development as an ethical, responsible, sociable and even cosmic being. Seen in this respect, chuchik(推測) is not simply a cognitive maneuver but a powerful catalyst which help bind all entities under heaven in a great harmonious whole.

• Current Industrial and Technological Trends in Aerospace
• /
• v.7 no.1
• /
• pp.141-152
• /
• 2009

The simultaneous operation of multiple UAV's makes it possible for us to raise the mission accomplishment and cost efficiency. For this we need an easily scalable control algorithm, and swarm intelligence having the characteristics such as flexibility, robustness, decentralized control and self-organization comes into the spotlight as a practical substitute. In this paper the features of swarm intelligence are described, and various research results are introduced which show that the application of swarm intelligence to the control of multiple UAV's enables the missions of surveillance, path planning, target tracking and attack to be accomplished efficiently by simulations and tests.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.11
• /
• pp.2717-2722
• /
• 2013

Sophisticated business intelligent software and personalized web services help collecting and mining huge amounts of personal information. This increase in digitalized personal information and advances in Internet technologies poses new challenges to consumers' information privacy. Based on the identified concept of information privacy concerns (IPC), this study additionally explores the interrelationships among consumers' individual characteristics(self-efficacy, digital literacy, customer alienation), customer satisfaction and intention to buy in e-commerce process. Academically, this study extends IPC to an empirical research model by identifying the conceptualization and organization of IPC. Moreover, practically, e-commerce providers can develop how to relieve IPC of online consumers.

• Journal of Biomedical Engineering Research
• /
• v.20 no.1
• /
• pp.59-68
• /
• 1999

In this paper, we propose an algorithm to locate the corpus callosum automatically from midsagittal brain MR images using the statistical characteristics and shape information of the corpus callosum. In the proposed algorithm, we first extract regions satisfying the statistical characteristics of the corpus callosum and then find a region matching the shape information. In order to match the shape information, a new directed window region-growing algorithm is proposed instead of using conventional contour matching algorithms. Using the proposed algorithm, we adaptively relax the statistical requirement until we find a region matching the shape information. Experiments show promising results.

• The Korean Journal of Applied Statistics
• /
• v.34 no.2
• /
• pp.127-139
• /
• 2021

Independent Component Analysis is a popular statistical method to separate independent signals from the mixed data, and Group Independent Component Analysis is an its multi-subject extension of Independent Component Analysis. It has been applied Functional Magnetic Resonance Imaging data and provides promising results. However, classical Group Independent Component Analysis works poorly when outliers exist on data which is frequently occurred in Magnetic Resonance Imaging scanning. In this study, we propose a robust version of the Group Independent Component Analysis based on ROBPCA. Through the numerical studies, we compare proposed method to the conventional method, and verify the robustness of the proposed method.