• Journal of the Society of Naval Architects of Korea
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• v.57 no.6
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• pp.345-352
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• 2020

This study aims to investigate the crabbing motion of the research vessel "NARA" by full-scale maneuvering trials. The crabbing test method refers to ITTC recommended procedures and guidelines. In order to minimize the fluctuation of the heading angle due to the external force acting on the hull during the pure lateral motion, the tests are conducted using the dynamic positioning system applied to the ship. The test results are analyzed by applying a low-pass filter to remove the noise included in the measurement data. Three conditions are set to define the steady state of crabbing motion. The index to be derived from the crabbing test is quantitatively presented. The ship is confirmed to be capable of the lateral motion of up to 0.844m/s in Beaufort 3.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.6 no.3
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• pp.532-543
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• 1999

This study was conducted to provide the basic data necessary for the improvement of the teaching method for basic nursing practice as well as the effectiveness of the practice by examining the students' competency in cleansing enema after doing the self study instead of the traditional education. To examine the competency in cleansing enema after the self study, this study is an one group pretest-posttest design that subjects did the enema practice through the self study. The subjects were 89 sophomore students at Y University. College of Nursing. In basic nursing lab practice class, cleansing enema self study module was given to the students which was developed by the researcher based on the literature review and asked them to finish doing the pre study and checking the self study evaluation criteria after reading the goal, learning activities and theoretical guideline. After watching the video tape, students practiced the process in the module by themselves. For the competency in cleansing enema. repeated autonomous practices were done during the open lab other than the regular class. Whenever the practice was done, the frequency and time were measure and documented. When the student felt confident through repeated practices, the competency was evaluated by the researcher and two assistants based on the evaluation criteria. And the process was repeated till the student could perform all the items on evaluation criteria completely. The data were collected for 42 days from Oct. 15 to Nov. 26 in 1996. Collected data were analyzed by frequency, percentage, Pearson correlation coefficient and variance analysis. The results are summarized as follows : 1. 43.2% of the students were favorable to nursing and 63.6% like lecture, but 71.6% like practice. So they were more interested in practice than in lecture. 2. 62.3% of the students scored high in written test, 97.8% scored high in practice. So the practice score was better. 3. The frequency of repeated practice to pass the test ranged from 1 to 4 and the average is 2.2. 4. The average time needed in preparation and the performance was nearly the same regardless of the frequency. It took 5 to 38 minutes for those who passed the test after practicing once and the average was 16 minutes. 5 to 60 minutes were taken for those who practiced twice to pass the test and the average was 21 minutes. Those who passed the test after three practices needed 8 to 30 minutes and the average was 15 minutes, which was similar to the time that the students who passed the test for the first trial. Only one student passed the test after 4 practices and it took 10 minutes. 5. 64% of the students agreed that the context and the content of the module were appropriate for the self study and 68.2% were satisfied. And 71.9% said that the module helped them to practice the enema self study 6. Though only 42% of the students were satisfied with the video. 50.6% said that it was helpful for the self study. 7. 52.3% of the students were satisfied with the self study method, and 86.6% obtained self-confidence when performing the enema. 8. The lower the student's practice score was, the more practices were needed for them to pass the test(r=-.213, P<.05). As a result, for performing the enema practice competently, two or more practice opportunities were needed to be given. And it is possible to obtain the less complex nursing skills through the self study, when enough learning resources and assistance such as learning guidance or video tapes are provided. Based on this study. I want to suggest that. 1. There must be college policy that can support the new method instead of the traditional learning method for the students to attain the proficiency in basic nursing skills. 2. The assistant materials should be developed as soon as possible to promote the self study of basic nursing skills.

• Journal of Ocean Engineering and Technology
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• v.20 no.2 s.69
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• pp.52-58
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• 2006

The effect of various environmental conditions on the durability of E-glass fiber/vinylester resin composites have been investigated using the tensile test specimen of strand type. It was found that the durability test method performed by the stand type specimen was more convenient and reliable than other conventional test method. The weight gains increased with the immersion time in both water and alkaline solution, and the Weight gains at $50^{\circ}C$. were much bigger than those at $20^{\circ}C$ in both conditions. The tensile strength decreased with the pass of immersion time in all aqueous solution, and the tensile strength at $80^{\circ}C$ in alkaline solution decreased very steeply at beginning of immersion time. The decrement of tensile strength according to the immersion time in various environmental conditions was mainly caused by the degradation of interface and the damage of glass fiber surface.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.52-56
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• 2004

Unmanned Aerial Vehicles (UAVs) are remotely piloted or self-piloted aircraft by inputted program in advance or artificial intelligence. In this study Aileron and Elevator are used to control the movement of airplane for horizontal and vertical flights about its longitudinal and lateral axis. In an introduction, the drone was linearly modeled by extracting aerodynamic parameter through flight test and simulation, lift and drag coefficient corresponding to angle of attack, changes of pitching moment coefficient. In the main subject, the flight simulation was performed after constructing hardware using TMS320F2812 from TI company and PID with lateral and longitudinal controller for horizontal and vertical flights. Flying characteristics of two system were estimated and compared through real flight test with hardware equipped algorithm and adaptive algorithm that was applied to consider external factors such as turbulence. In conclusion the control performance of the controller with proposed algorithm was streamlined at lateral and longitudinal controller respectively, we will discuss guidance command to pass way point.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.6
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• pp.562-566
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• 1991

Many research and development activities have found that Superconducting Generators (SCG) have advantages such as high efficiency, light weight, small size, large unit size and good steady-state stability over conventional ones. However the transient stability of SCG is comparable to that of conventional ones. One way to improve the transient stability of SCG is to apply quick-response excitation system to the SCG. For this purpose, an SCG with an electrothermal shield of short electric time constants should be developed. In this paper, a new electrothermal shield, called slitted electrothermal shield(SES), is proposed. The SES can easily transmit radiated heat into the ends of the shield as in the conventional electrothermal shields(CES) and can easily pass magnetic flux produced by armature and field windings. By finite element analysis and experimental test, the slitting effects of SES on magnetic shielding are compared. Good agreement is obtained between simulated and test results.

• 전기의세계
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• v.18 no.1
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• pp.15-23
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• 1969

A lot of recent researches have shown that a Pseudo Random Binary Signal is a quite effective test signal to measure the impulse response of a plant. Generally speaking, however, such a response itself is not satisfactory to determine the appropriate control parameters or control inputs. Here, the author intends to estimate the unknown parameters of the First Order Plant with Dead Time by means of correlation method using M-sequence signal. The time constant T and the dead time L of the plant are eatimated with one tracking loop by automatically adjusting delay time .tau. of M-sequence signal according to variations of T and L. In this paper, a three level M-sequence signal is used as a test signal in order to avoid troublesome operations to calculate partial derivatives of a given performance index with respect to the parameters which are usually required in the Model Method. Several experiments with analogue computer using low pass filters as averaging circuits showed good results as expected.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.703-704
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• 2007

Most of the transmission lines in Korea pass through a mountains. The forest fire occurred in around the transmission lines make an accident such as flashover and faults in the power transmission lines. In spite of that risk, there are no research on the flashover characteristics by fires in electric discharge engineering in our country. This paper was mentioned about the relation between the flame and flashover characteristics. We were carried out simple test by using artificial flame generator and rod-plane or conductor-plane gaps. And we were summarized test results.

• Journal of Oriental Neuropsychiatry
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• v.9 no.2
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• pp.37-44
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• 1998

Purpose: This study was conducted to find out the effects od Sahyangsohapwon on learning and memory of rats.Method: In the experiment, rats were divided two groups. One was control group which was adminstered Sahyangsohapwon and the other was sample group administered placebo. Numbers of each group were 13 rats. 8-arm radial maze task was used in it, and working memory test and retention(reference memory) test were done.Before the beginning of the test, the rats were deprived of water for 24hrs.In the frist test, each of eight arm was baited with water and a rat was permitted to remain on the maze until all eight arms were entered. A working memory error was defined as revisit of any previously entered arm. When a rat made an error not exceeding one time in consecutive 3 days-performance, it was regarded as learning criteria and the test was ended. The reference memory was evaluated with total days which it took rats to pass the learning crtirtia.The second test was performed after 24 hours when the first test was over. When a rat entered 4 arms, the entrance of arm was cut off during 30 seconds.Here the number if errors which was produced during a rat find remaining 4 tracks was regarded as the index of memory.This experiment compared the number of error at the control group with that of the sample group.Result: 1. In the first test, it was shown that the sample group took 7.69${\pm}$1.11 days and the control group 9.31${\pm}$1.97 days to pass the learning criteria.There was statistically significant reference mernory development at the sample group.2. In the second test, the frequency of errors made by the two groups were 0.92${\pm}$1.32 times for the control group and 1.23${\pm}$1.59 times for the Sahyangsohapwon group. There was no difference between the groups in frequency of errors.Conclusion: It is suggested that Sahyangsohapwon has effects on the improvement of learning and memory.

• Korean journal of communication and information
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• v.39
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• pp.69-101
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• 2007

Some clauses of the prior review rules for broadcasting commercials, which are enforced by the Broadcasting Act violate the right to free speech guaranteed by the Constitution. The range of prohibited expression under the clauses are too vague and overbroad to distinguish between permissible and impermissible broadcasting commercials. The clauses also fail to pass the constitutional principle that restrict government from excessive regulation on constitutional rights. The principle has a four-pronged test on the government action; 1) the validity of its goal; 2) availability of appropriate means; 3) necessity of infringement; 4) and balancing test of interests. Some clauses of the prior review rules that forbid expressions on sensitive political and cultural issues fail to pass none of the four-pronged standards.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.11
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• pp.787-797
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• 2015

In this paper, a cochlea-inspired artificial filter bank(CAFB) was developed in order to efficiently acquire dynamic response of structure, and it was also evaluated via dynamic response experiments. To sort out signals containing significant modal information from all the dynamic responses of structure, it was made to adopt a band-pass filter optimizing algorithm(BOA) and a peak-picking algorithm (PPA). Optimally designed on the basis of El-centro and Kobe earthquake signals, it was then embedded into the wireless multi-measurement system(WiMMS). In order to evaluate the performance of the developed CAFB, a vibration test was conducted using the El-centro and Kobe earthquake signals, and structural responses of a two-span bridge were obtained and analyzed simultaneously by both a wired measurement system and a CAFB-based WiMMS. The test results showed that the compressed dynamic responses acquired by the CAFB-based WiMMS matched with those of the wired system, and they included significant modal information of the two-span bridge. Therefore this study showed that the developed CAFB could be used as a new, economic, and efficient measurement device for wireless sensor networks(WSNs) based real time structural health monitoring because it could reconstruct the whole dynamic response using the compressed dynamic response with significant modal information.