• Journal of Korean Society of Environmental Engineers
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• v.39 no.5
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• pp.282-287
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• 2017

The purpose of this study was predicted the effects of mixing and diffusion due to the operation of the apparatus before the development of the mixed diffusion device for the decontamination absorbent to minimize the influence of contaminant inflow due to radiation accident. The tracer used for the flow characteristics was $^{68}Ga$, $^{99m}Tc$, which is a radioactive isotope, and 2 inch NaI radiation detector was used to detect it. The impeller of the decontamination mixed diffusion system applied to this study was made into three types and the mixing diffusion effect was compared. As a result of analyzing the flow characteristics of the radio-isotope with decontamination mixed diffusion device, mixing, diffusion and flow pattern were obtained. The radial mixing type impeller was able to diffuse to the water surface by the upflow flow, and the fin structure was adjusted for finding optimal conditions. The model 3 type consists of a fin guiding part and an auxiliary fin so that the diffusion speed is higher than that of other types of impellers. It also showed a short time to reach complete mixing.

• The Journal of the Korea Contents Association
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• v.16 no.2
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• pp.686-695
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• 2016

In this thesis, girls' suicidal mentality which appears in some adolescent novels was sought. We can conclude like these: first, in the novel, Elegant Lies written by Ryeo-ryung Kim, the girl named Wha-yun leaves out Cheon-ji not to be left out alone by her companies. Wha-yun has succeeded in giving an ugly impression of Cheon-ji to the peer girls around her by exercising relational aggression. As a result, Cheon-ji sees herself as a meaningless being and after recognizing that she can't change the situation, she shows psychology of escape. Second, in the novel, Goodbye, from Kilimanjaro written by Ok-soo Lee, Sung-min Yoon's girlfriend Soo-hee born and grown in Africa lives with trauma from her mother's death. As her step-mother suppressed her not to keep in touch with the pet animals, Soo-hee got depressed and out of energy. Parental oppression and verbal violence can let the girl activates self-punishment and lead to suicide. Third, in the novel, Thursday, in Cyprus written by Chae-ran Park, girls could use suicide as a negotiation agenda. Adolescents could commit suicide even if their trivial requests are rejected. In these situations above we can read anticipation of compensation, retaliation and self-punishment mentality.

• The Journal of the Acoustical Society of Korea
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• v.30 no.8
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• pp.421-427
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• 2011

This study aimed to figure out the numbers and note distributions and sexagenary cycles of old pyeongyoungs systematically, and estimate the nominal frequency of whangjongeum, the Korean tradition pitch standard. As a total 214 old stones in the National Palace Museum, the National Kukak Center, the Kukak National High School were counted by notes and sexagenaries. The nominal frequencies of 17 old whangjong stones' sounds were categorized by cluster analysis method. Using nominal frequencies of stones according to their sexagenaries and Korean traditional intonation were used to estimate the nominal frequencies of the whangjong. The nominal frequency can be estimated by 22 Keychuk stones as 266.9 Hz, by Cheongyu and Gabja stones as 262.4~262.5 Hz, and by Gabjin, Sowha 12 and Sowha 13 as Estimating by 22 Kyechuk stones which were matched with the records. These results seem to be more reliable, because it is based on the whol samples of old pyeongyoungs, while the former studies have been based on couples of whangjong stones' sounds.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.320-326
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• 2017

Multistage deep-drawing technology is used widely in the production of mobile phone battery cases to improve productivity and economy. To ensure adequate capacity and rigidity, such cases are fabricated as a rectangular cup with a high slender ratio. The multistage deep-drawing of a rectangular cup entails a high slender ratio, and the heights of the product sides may be non-uniform because of the complicated deformation mechanisms. This causes problems in product assembly that affects the surface quality of the case. This study examined a blank shape that minimizes the height variations of the product to resolve the aforementioned problems. Optimization design and analysis were performed to identify the shape that yields the least variation. The long and short sides of an oval blank were set as the design variables. The objective function was set to yield the lowest height difference, and the thickness reduction rate of the product was set to the target range. In addition, the height of the final shape was set as a constraint. The height difference was minimized successfully using the optimized design. The design process of the initial blank for all rectangular shapes can be automated in the future.

• Journal of Aerospace System Engineering
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• v.14 no.1
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• pp.28-35
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• 2020

This paper presents the design improvements made for the crack which is in the mounting structure of the mechanical structure of rotary wing aircraft. The doubler added to the mounting structure of rotary wing aircraft was designed and manufactured based on the load at the development stage, and a crack was found in the surface of doubler at a certain point during the operation of the aircraft. To identify the cause of the crack, the initial deformation of the structure, which may occur as a result of fastening condition, was considered and the dynamic analysis of the natural frequency of the structure comparing to the blade passing frequency of the aircraft were additionally reviewed. As a result of this study, a shim was added to remove the physical gap of the fastening area, and a doubler with thickened reinforcement was installed. The increase of structural strength is shown by reviewing the results of dynamic analysis for the structural verification of the improved design, and the fatigue evaluation complied to the requirement of the aircraft lifetime.

• Korean Journal of Applied Biomechanics
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• v.18 no.4
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• pp.109-114
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• 2008

The purpose of this study was to estimate the energy expenditure simply and practically during physical activities. The physical activity is quantified by the integration of the accelerometer signals obtained from the triaxial accelerometer attached at the waist level of the human body. To find a relationship between energy expenditure and accelerometer data, 6 male and 5 female subjects walked and ran on the treadmill with speeds of 1.5, 3.0, 4.5, 6.0, 6.5, 7.0, and 8.5 km/hr. Each subject performed walking at the speed lower than 6.0 km/hr and running at the speed higher than 6.5 km/hr. Actual energy expenditure was determined by a continuous direct gas analyzer. Two predictive equations of walking and running mode for energy expenditure which includes gender, body mass index(BMI) and data from accelerometer were developed using multiple regression analysis. The correlation coefficients and coefficients of determination between the estimated and measured energy expenditure were R=0.936, R2=0.876 and R=0.881, R2=0.776 in walking and running mode, respectively. For further study, experiments on a larger scale of test subjects are essential for acquiring more reliable results.

• Journal of the Korean Geographical Society
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• v.45 no.1
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• pp.144-164
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• 2010

This study aims to reveal path selection strategies and individual differences in a navigation task. Two experiments were presented that studied human route planning performance as well as the cognitive strategies and processes involved. For the outdoor task, university students were asked to select a route based on the instruction, i.e. to find the best route from the campus main gate to the Education Building for conference visitors by locating eight signposts. Results indicate (1) that locations of signposts were selected preferably at decision points where the traveler needs to make a choice and starting/ending points of the navigation task and (2) a variety of route planning strategies considering efficiency goal (e.g., the shortest path), environmental characteristics (e.g., fewest turns), and aesthetic purpose (e.g., most scenic) were used. It is notable that some participants took into account more than one path by locating one or two signposts on an alternative route while others preferred a linear route connecting signposts between the start point and the destination. Prior to the main experiment, the same participants were asked to complete the same task inside the classroom to investigate changes in strategies between two tasks. Participants often tend to place signposts at more regular intervals for the indoor navigation task than the same task conducted outside.

• Journal of The Korean Association For Science Education
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• v.36 no.2
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• pp.231-251
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• 2016

The goal of the study was to examine pre-service teachers' emotional experiences, especially during student teaching. The following questions guided this study. First, during student teaching, what are the characteristics of emotional experiences of pre-service science teachers? Second, what are used as the emotional rules and strategies by student teacher? In this study, we tracked nine pre-service science teachers over a four-week period of the student teaching. The data sources were lesson observations, interviews, emotional journals, and video-recorded classroom lessons. Results showed that student teachers experienced various 25 different types of emotions which were reported as the primary emotions of Koreans. The main subjects for interaction for positive emotions were students. For negative emotions, students, teachers and student teachers themselves all resulted in such negative emotional experiences. When the student teachers experienced negative emotions, they followed the emotional rule that their emotions should not be expressed in front of the students. Because of this, they tried various strategies for controlling emotions, such as 'understanding students', 'finding the positive side', 'seeing good students', 'ignoring', 'holding back', 'evading', and 'giving up'. Finally, suggestions for teacher education were discussed.

• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2349-2360
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• 2000

In medical image processing, if new technologies arc developed, they arc applied to real clinical cases. The results are to be analyzed by doctors to improve the new technologies. So, it is important for doctors to have a tool that helps the doctors in applying the new technologies to clinical cases and analyzing the clinical results. In this paper, we design and implement a visual programming environment where non-programming experts, such as medical doctors, can easily compose a medical image processing application program. A set of image processing functions are implemented and represented as icons. Thc user selects functions by clicking correslxmding icons. The users can easily find necessary' functions from the visualized library. A user selects a function from the visualized library and [Jut the function node into a canvas of Visual Programming Interface. The user connects nodes to compose a dataflow diagram. The connected dataflow diagram shows the now of the program. Hyperbolic Tree is helpful in visualizing a set of function icons in a single screen because it provides both the whole stmcture of the function Iihrary and the details of the focused functions at the same time. We also developed a CUI builder where the user interfaces of the medical image processing applications are composed. Therefore. non'programming experts such as physicians can apply new medical image processing algorithms to clinical cases without performing complex computer programming procedures.

• Journal of Korea Spatial Information System Society
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• v.4 no.2 s.8
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• pp.55-64
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• 2002

VEfficient generation of road data is one of the most important issues in GIS (Geographic Information System). In this paper, we propose a hybrid approach for automatic generation of road data by combining mobile mapping and image processing techniques. Mobile mapping systems have a form of vehicle equipped with CCD camera, GPS, and INS. They can calculate absolute position of objects that appear in acquired image by photogrammetry, but it is labor-intensive and time-consuming. Automatic road detection methods have been studied also by image processing technology. However, the methods are likely to fail because of obstacles and exceptive conditions in the real world. To overcome the problems, we suggest a hybrid method for automatic road generation, by exploiting both GPS/INS data acquired by mobile mapping system and image processing algorithms. We design an estimator to estimate 3-D coordinates of road line and corresponding location in an image. The estimation process reduces complicated image processing operations that find road line. The missing coordinates of road line due to failure of estimation are obtained by cubic spline interpolation. The interpolation is done piecewise, separated by rapid change such as road intersection. We present experimental results of the suggested estimation and interpolation methods with image sequences acquired by mobile mapping system, and show that the methods are effective in generation of road data.