• Journal of the Korean earth science society
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• v.27 no.3
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• pp.289-301
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• 2006

The purpose of this study is to investigate beginning secondary science teachers' teaching practices in terms of motivating and understanding students. Six first-year teachers participated in this study. Data were collected by classroom observations and structured interviews. Instructional materials used during the class were also collected to understand teaching practice. Lessons observed were video-tape recorded and the teachers were interviewed. Video- and audio-tape recording were transcribed. The framework, developed by Knowles Project Team of Michigan State University, was adopted and revised according to Korean classroom context and employed as an analytical tool for teaching practices. The beginning secondary science teachers intention ranged from 'Managing Work' to 'School Science.' No teachers revealed 'Reform Science Teaching' orientation. For the execution of science lessons, one teacher with 'Managing Work' orientation showed 'expert' level of execution, but the others executed at a 'novice' level. Beginning science teachers need to be guided and informed about 'Reform Science Teaching' for motivating and understanding students to develop professionally.

• Women's Health Nursing
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• v.21 no.3
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• pp.241-251
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• 2015

Purpose: The purpose of this study was to explore preserved belief system supporting Korean immigrant women's Taekyo practices and influencing factors while they observe the tradition within US sociocultural context. Methods: Leininger's exploratory focused ethnographic approach was used. Semi-structured in-depth interviews were conducted with purposive sample of sixteen Korean immigrant women who gave birth in the US within last 6 months. Researcher's observation and reflective field notes were also integrated into the interview data. Leininger and McFarland's four phases of ethnographic analysis guided data analysis process. Results: The perceived belief system supporting Taekyo practices included Taekyo as an enculturated Korean tradition, connecting parents with fetus, and positive impacts on fetal development. And Korean immigrant women's Taekyo practices were influenced by resources of information, woman's orientation toward Taekyo, pressure from local Korean community, and child order. Conclusion: The findings from this research would serve as an important knowledge base to expand US health care providers' understanding of Korean traditional Taekyo practices observed by Korean immigrant women's as important prenatal self-care practices. The findings could also aid in providing more patient-centered and culturally-tailored prenatal care plan to Korean immigrant by including Korean traditional belief system supporting Taekyo practices.

• Journal of Ocean Engineering and Technology
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• v.21 no.4
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• pp.45-54
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• 2007

In the context of auto-landing containers from a container ship to a truck or automatic guided vehicle and vice versa, this research investigates three schemes, one in Part I and two in Part II, for measuring the absolute position of a container. Coordinate transformations between the reference-coordinate, sensor-coordinate, and body-coordinate systems are briefly discussed. The scheme explored in Part I aims the use of three laser-slit sensors, which are relatively inexpensive. In this case, nine nonlinear equations are formulated for six unknown variables (three for orientation and three for position), so a closed-form solution is not available. Instead, an approximate solution through linearization was derived. An advantage of the method in Part I is its ability to measure an absolute position in 3D space, while a disadvantage is the computation time required to obtain pseudo-inverses and the approximate nature of the obtained solution. Numerical examples are provided.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.153-158
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• 2004

The coupling phenomenon between stress and magnetic induction, known as magnetostriction, has been successfully applied to generate and measure elastic waves. Most applications of this phenomenon thus far, however, are rather limited to cylindrical ferromagnetic waveguides. The main objective of this work is to develop a new patch-type, orientation-adjustable magnetostrictive transducer that is applicable for non-cylindrical, non-ferromagnetic waveguides. The existing patch-type transducer consisting of a ferromagnetic patch and a racetrack coil is useful to generate elastic waves only in one specific direction once the patch is bonded to a test specimen. However, the proposed transducer can transmit and receive elastic waves in any direction only with one patch at a given location. The proposed magnetostrictive transducer consists of a circular nickel patch, a figure-of-eight coil, and a couple of bias permanent magnets. Because of the unique configuration of the transducer, the propagating direction of the generated waves can be freely controlled since the set of bias magnets and the coil is not bonded to the magnetostrictive patch. In this work, the characteristics of the proposed transducer were investigated experimentally.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.8
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• pp.579-584
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• 2016

When surgical instruments are tracked in an image-guided surgical navigation system, a stereo vision system with high accuracy is generally used, which is called optical tracker. However, this optical tracker has the disadvantage that a line-of-sight between the tracker and surgical instrument must be maintained. Therefore, to complement the disadvantage of optical tracking systems, an internal vision sensor is attached to a surgical instrument in this paper. Monitoring the target marker pattern attached on patient with this vision sensor, this surgical instrument is possible to be tracked even when the line-of-sight of the optical tracker is occluded. To verify the system's effectiveness, a series of basic experiments is carried out. Lastly, an integration experiment is conducted. The experimental results show that rotational error is bounded to max $1.32^{\circ}$ and mean $0.35^{\circ}$, and translation error is in max 1.72mm and mean 0.58mm. Finally, it is confirmed that the proposed tool tracking method using an internal vision sensor is useful and effective to overcome the occlusion problem of the optical tracker.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.856-859
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• 2005

The OPMT(Orientation-adjustable Patch-type Magnetostrictive Transducer) was proposed as a tool for generating and measuring the ultrasonic Lamb wave in plate type structures. This sensor has a lot of new features compared to the traditional piezo-type ultrasonic transducers. As an example, it does not need any kind of wiring for lunching or measuring ultrasonic waves. But it has also definite limitation for practical usage as a nondestructive testing tool in that it cannot help rotating the direction of ultrasonic wave manually. The idea for 'scanning OPMT' is proposed in this respect. Two kinds of basic ideas for rotating the wave direction not manually but electrically are proposed. The fabrication of the transducer and the testing for Identifying the primary characteristics are done for one of the proposed transducers. The results says that there are the possibilities as a new tool for NDE in that the proposed transducer follows well the characteristics of the traditional OPMT. But there are also the 1imitations to overcome.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.11
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• pp.965-972
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• 2016

This paper presents results of flight experiments on a navigation algorithm including multiplicative extended Kalman filter for estimating attitude of the guided munition. The filter describes orientation of aircraft by data fusion with low-cost sensors where measurement update is done by multiplication, rather than addition, which is suitable for quaternion representation. In determining attitude from vector observations, the existing approach utilizes a 3-axis accelerometer as a 2-axis inclinometer by measuring gravity to estimate pitch and roll angles, while GNSS velocity is used to derive heading of the vehicle. However, during accelerated maneuvers such as coordinated flight, the accelerometer provides inadequate inclinometer measurements. In this paper, the measurement update process is newly defined to complement the vulnerability by using different vector observations. The acceleration measurement is considered as a result of a centrifugal force and gravity during turning maneuvers and used to estimate roll angle. The effectiveness of the proposed method is verified through flight experiments.

• Journal of The Korean Association For Science Education
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• v.27 no.5
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• pp.432-446
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• 2007

The purpose of the study is to explore the science teaching orientations of secondary science teachers, and how they influence the planning and execution of reform-based lessons. Professional development workshop for constructivist teaching consisted of three different phases; five lectures, small group discussion, and preparing lesson plans. Four teachers who participated also executed their lesson plans in their own classroom. All workshops were videotape recorded. Classroom observations and interviews were conducted and recorded. Instructional materials were also collected for each science class. All data recorded were transcribed and analyzed. Based on the data collected from multiple sources, we identified each teacher's teaching orientations, and through this lens, we also tried to understand their classroom practices. We expected teacher-participants to implement constructivist science teaching. However, the differences among teachers in the course of actual planning and implementing activities for constructivist science was wider than we expected and even some teachers were unsuccessful. Teaching orientations can act as a filter for teachers when they decide whether to accept and apply new knowledge about teaching and learning to actual lessons or not. Even if a teacher plans a guided-inquiry lesson, her/his didactic teaching orientation could be revealed in actual classroom, and lead her/his class to other direction which is quite different from her/his original intention. Although the teachers participated in the same workshops in our study, they planned and executed differently and their own teaching orientations contribute substantially to their practice. Understanding the role of science teaching orientations could be an important step in addressing issues of diverse difficulties in supporting reform efforts in science.

• Journal of Biomedical Engineering Research
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• v.37 no.2
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• pp.68-74
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• 2016

In this study, we investigated the rotational characteristics which were comprised of directionality and linearity of target registration error (TRE) as a study in advance to enhance the accuracy of contour-based registration in neuronavigation. For the experiment, two rigid head phantoms that have different faces with specially designed target frame fixed inside of the phantoms were used. Three-dimensional coordinates of facial surface point cloud and target point of the phantoms were acquired using computed tomography (CT) and 3D scanner. Iterative closest point (ICP) method was used for registration of two different point cloud and the directionality and linearity of TRE in overall head were calculated by using 3D position of targets after registration. As a result, it was represented that TRE had consistent direction in overall head region and was increased in linear fashion as distance from facial surface, but did not show high linearity. These results indicated that it is possible for decrease TRE by controlling orientation of facial surface point cloud acquired from scanner, and the prediction of TRE from surface registration error can decrease the registration accuracy in lesion. In the further studies, we have to develop the contour-based registration method for improvement of accuracy by considering rotational characteristics of TRE.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.48 no.2
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• pp.165-173
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• 2012

Nationally, flatfish vaccination has been performed manually, and is a laborious and time-consuming procedure with low accuracy. The handling requirement also makes it prone to contamination. With a view to eliminating these drawbacks, we designed an automatic vaccine system in which the injection is delivered by a Cartesian coordinate robot guided by a vision system. The automatic vaccine injection system is driven by an injection site location algorithm that uses a template-matching technique. The proposed algorithm was designed to derive the time and possible angles of injection by comparing a search area with a template. The algorithm is able to vaccinate various sizes of flatfish, even when they are loaded at different angles. We validated the performance of the proposed algorithm by analyzing the injection error under randomly generated loading angles. The proposed algorithm allowed an injection rate of 2000 per hour on average. Vaccination of flatfish with a body length of up to 500mm was possible, even when the orientation of the fish was random. The injection errors in various sizes of flatfish were very small, ranging from 0 to 0.6mm.