• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.2
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• pp.129-138
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• 2021

Due to the active progress in space programs for various types of ground and space missions, the high agile spacecraft maneuverability is also required. To meet the requirement of the given space missions, the Control Moment Gyros (CMG) for the alternatives of the classical reaction wheels can release the attitude maneuverability restrictions. In addition, the angular rates of the spacecraft is constrained due to the limited actuator characteristics. In this paper, a sliding mode control technique for the attitude control of the spacecraft equipped with the pyramid type of CSCMG(Constant Speed CMG) is designed, and the stability of the control system is guaranteed by using the Lyapunov stability theory. Finally, the control law proposed is analyized by numertical simulations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.3
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• pp.678-700
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• 2023

Diagnosing breast diseases using ultrasound (US) images remains challenging because it is time-consuming and requires expert radiologist knowledge. As a result, the diagnostic performance is significantly biased. To assist radiologists in this process, computer-aided diagnosis (CAD) systems have been developed and used in practice. This type of system is used not only to assist radiologists in examining breast ultrasound images (BUS) but also to ensure the effectiveness of the diagnostic process. In this study, we propose a new approach for breast lesion localization and segmentation using a multi-scale pyramid of the ultrasound image of a breast organ and a convolutional semantic segmentation network. Unlike previous studies that used only a deep detection/segmentation neural network on a single breast ultrasound image, we propose to use multiple images generated from an input image at different scales for the localization and segmentation process. By combining the localization/segmentation results obtained from the input image at different scales, the system performance was enhanced compared with that of the previous studies. The experimental results with two public datasets confirmed the effectiveness of the proposed approach by producing superior localization/segmentation results compared with those obtained in previous studies.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.4
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• pp.394-400
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• 2008

Crop characteristics of 137 common millet (Panicum miliaceum L.) resources collected in Korea were investigated in order to establish basic data for the improvement of crop breeding. Spike types of 137 plant resources were classified as 4 types of oblate, spreading, oblate-compact (intermediary type between oblate and compact) and oblate-spreading (intermediary type between oblate and compact) type, of which oblate spike type was the highest percentage of 66.4% (91 plant resources) of 137 germplasm. Seed color was classified as 5 colors of dark brown, yellow, brown, yellowish brown, and yellowish white, of which yellowish white was the highest percentage of 66.4% (54 plant resources) among them. Seed type was classified as 2 types of pyramid shape and short pyramid shape, which showed 62.8% and 37.2% respectively. Days from seeding to heading date showed the range from 68 to 85 days with 73.7 days in the average and the highest frequency proportion of it was the group from 70 to 75 days, which occupied 46.7% (64 plant resources) of 137 germplasm. Days from seeding to physiological maturity showed the range from 109 to 124 days with 112.0 days in the average and the highest frequency proportion (60.6%) of it was the group from 111 to 115 days, while there were also occupied with 6.6% below 110 days and 5.1% over 120 days among 137 germplasm. Group from 181 cm to 190 cm of culm length showed the highest frequency proportion of 47.4%, whereas below 160 cm was the lowest occupancy of 2.9%. Spike length showed the range from 181 to 190 cm with 181.4 cm in the average and the highest frequency distribution of it was the group from 31 to 35 cm with the proportion of 54.0%. Number of grains per spike showed the range from 432 to 2,665 grains with 1,429.5 grains in the average and group from 1,200 to 1,400 grains per spike was the highest frequency distribution with the proportion of 20.4%. There were also occupied with 13.1% below 1,000 grains and 8.6% over 2,000 grains per spike among 137 germplasm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.10
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• pp.948-956
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• 2014

Today, Intelligent Vehicle Detection System seeks to reduce the negative factors, such as accidents over to get the traffic information of existing system. This paper proposes detection algorithm for the illegal U-turn vehicles which can cause critical accident among violations of road traffic laws. We predicted that if calculated optical flow vectors were shown on the illegal U-turn path, they would be cause of the illegal U-turn vehicles. To reduce the high computational complexity, we use the algorithm of pyramid Lucas-Kanade. This algorithm only track the key-points likely corners. Because of the high computational complexity, we detect center lane first through the color information and progressive probabilistic hough transform and apply to the around of center lane. And then we select vectors on illegal U-turn path and calculate reliability to check whether vectors is cause of the illegal U-turn vehicles or not. Finally, In order to evaluate the algorithm, we calculate process time of the type of algorithm and prove that proposed algorithm is efficiently.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.2
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• pp.231-242
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• 2014

It is throwing the spotlight on the cultivation crops about high quality crops and productivity improvement per unit area because of rapid climate change caused by global warming. Therefore, we propose a water culture management of circulation nutrient method control system applies to solar tracking method not using traditional method of deep flow technique and artificial light source. We design it in the form of the circulation nutrient method in waterway of a certain amount of nutrient solution and water flowed into the way of circular. In addition, we design a multistage structure in pyramid shape which be possible continuous photosynthesis action to crops of water culture bottom part. Also, solar tracking method is designed five sensor method of center hole sensor method for tracking shadow of solar light not using traditional two hole, four hole sensor method. Finally, through the water culture device applies to solar light tracking method was not introduced in existing study yet, we can reduce growth speed of crops which be possible continuous photosynthesis action to crops. Moreover, We can expect high productivity of per unit area which be possible all crops can be offered growth environment of same type by using form of pyramid shape of multistage structure without top or bottom part.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.4
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• pp.90-96
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• 2016

Incremental sheet forming (ISF) is a highly versatile and flexible process for rapid manufacturing of complex sheet metal parts. Compared to conventional sheet forming processes, ISF is of a clear advantage in manufacturing small batch or customized parts. ISF needs die-less machine alone, while conventional sheet forming requires highly expensive facilities like dies, molds, and presses. This equipment takes long time to get preparation for manufacturing. However, ISF does not need the full facilities nor much cost and time. Because of the facts, ISF is continuously being used for small batch or prototyping manufacturing in current industries. However, spring-back induced in the process of incremental forming becomes a critical drawback on precision manufacturing. Since sheet metal, being a raw material for ISF, has property to resilience, spring-back would come in the case. It is the research objective to investigate how geometrical shaping parameters make effect on shape dimensional errors. In order to analyze the spring-back occurred in the process, this study experimented on Al 1015 material in the ISF. The statistical tool employed experimental design with factors. The table of orthogonal arrays of $L_8(2^7)$ are used to design the experiments and ANOVA method are employed to statistically analyze the collected data. The results of the analysis from this study shows that the type of shape and the slope of bottom are the significant, whereas the shape size, the shape height, and the side angle are not significant factors on dimensional errors. More error incurred on the pyramid than on the circular type in the experiments. The sloped bottom showed higher errors than the flat one.

• Journal of Korean Academy of Nursing
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• v.1 no.1
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• pp.3-26
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• 1970

That's an attempt to study about knowledge, attitudes and practice of the residents with regard to maternal child health, family, planning, and tuberculosis in rural area which was chosen to be a demonstration area for nursing students of College of Nursing, Yonsei University for their public health nursing practice. In addition, it is designed to collect information on population of the area such as age and sex distribution, mobility, and other characteristics also be sought by doing a census. The purpose of study is to obtain data which are needed for planning student learning experiences in the community. The information which was obtainable through this study is as follows; 1. In demographic aspect a. Population structure was a typical rural type in terms of population pyramid. b. Distribution of age and sex of residents showed more female in the older ages. c. Population has not moved much. Majority of them have been living in the area since their births. 2. In sociological aspect a. The level of education of female was comparatively lower than male. b. The residents of the area did not have any special religion. c. The economic status was found low or middle class. 3. In health practice In general health knowledge, attitudes and practice appeared to be poor. As a result of this study, it could be summararized that there are a great public health nursing needs in the community. According to these needs found and to it's nature, severity and massiveness, the nurse instructors with students were able to set up a priority system in services. Meanwhile student case load can be logically figured out in consideration of variety of experiences need for each student. The study helped student not only to find out resident characteristics and their health problems in terms of family and community problem but also to provide a good learning experience by participating in the interviewing. In sum this type of study is necessary for planning of student field experience when no data are available where students are going to have field experiences in public health nursing.

• Journal of Biomedical Engineering Research
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• v.41 no.4
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• pp.147-153
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• 2020

This study was to evaluate the usability of self-developed phantom for evaluating automatic exposure control (AEC) using three-dimensions (3D) printer. 3D printer of fused deposition modeling (FDM) type was utilized to make the self-developed AEC phantom and image acquisitions were conducted by two different type of scanners. The self-developed AEC phantom consisted of four different size of portions. As a result, two types of phantom (pyramid and pentagon shape) were created according to the combination of the layers. For evaluating the radiation dose with the two types of phantom, the values of tube current, computed tomography dose index volume (CTDIvol), and dose length product (DLP) were compared. As a result, it was confirmed that the values of tube current were properly reflected according to the thickness, and the CTDIvol and DLP were not significantly changed regardless of AEC functions of different scanners. In conclusion, the self-developed phantom by using 3D printer could assess whether the AEC function works well. So, we confirmed the possibility that a self-made phantom could replace the commercially expensive AEC performance evaluation phantom.

• Journal of The Korean Association For Science Education
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• v.13 no.1
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• pp.56-65
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• 1993

The purpose of this study is to analyze the inquiry activities of SCIIS and Korea primary school science curricular meterials and to make suggestions for the improvement of inquiry learning based on the analysis The Scientific Inquiry Evaluation Inventory (SIEI: Myung Hur, 1984) was used to evaluate the inquiry activity content of the primary school "Science, Level-6" and "SCIIS, Level-6" textbooks. The results are as follows: 1) The inquiry activities of Korean science textbooks are stressing on gathering and organizing data, but rarely require students to formulate a hypothesis, to design an experiment. 2) The SCIIS textbooks relatively tended to put more weight on interpreting/ analysing data and hypothesizing/ designing experiments. 3)The Korean science textbooks had little concern about establishing hypothesis and designing experiments, interpreting / analysing data. 4) The SCIIS textbooks require students to perform a variety of inquiry skills when compare to Korean science textbooks. 5) Competition / Cooperation Scale checks the level of competition and cooperation among student teams inherent in science curricular materials. The result from each team is incorporated into the formation of a class result. The communication is required to formulate a synthesized class response, enhances cooperation among teams. The SCIIS(84%) is the higher than Korea(50%) in cooperation scale. 6) Korean science textbooks rarely require students to discuss about experiment when compare to SCIIS textbooks. 7) Korean science textbooks provide students with both inquiry problems and experimental procedure, or including answers SCIIS textbooks provide students with both inquiry problems and experimental procedure, or problems only. 8) The Korean textbooks emphasize demonstrating or verifying of the text while the SCIlS emphasize extending the content of the text in inquiry scope scsle. The inquiry pyramid which helps analysis the inquiry activity curriculum as a whole is one of type 1- the course is centered on gathering and organizing data. The SCIIS are better than the Korean science textbook in the light of proportion of interpreting / analysing data and hypothesizing / designing experiments.

• The KIPS Transactions:PartB
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• v.10B no.2
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• pp.135-142
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• 2003

Robust extraction of 3D object's features, shape and global motion information from 2D image sequence is described. The object's 21 feature points on the pyramid type synthetic object are extracted automatically using color transform technique. The extracted features are used to recover the 3D shape and global motion of the object using stereo paraperspective camera model and sequential SVD(Singuiar Value Decomposition) factorization method. An inherent error of depth recovery due to the paraperspective camera model was removed by using the stereo image analysis. A 30 synthetic object with 21 features reflecting various position was designed and tested to show the performance of proposed algorithm by comparing the recovered shape and motion data with the measured values.