• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.12
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• pp.1025-1031
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• 2012

The present paper deals with concept design of supersonic inlet based on compressible flow theory and flow control of bleeding in order to guarantee stability of supersonic inlet of ramjet engine in broad range of operating conditions. Shock instability, shock wave-boundary layer interaction and flow separation should be properly controlled to improve performance of the supersonic inlet. Considering shock strength, boundary layer and flow separation, the supersonic inlet is modified from the basic model which is designed under inviscid theory. Consequently, shock is stabilized, and required mass flow rate is obtained. Furthermore, bleeding is applied to the supersonic inlet to maintain performance in off-design conditions. Mass flow condition is adopted for modeling of bleeding effect, and performance of the supersonic inlet is evaluated by changing bleeding locations and numbers.

• Journal of the Society of Naval Architects of Korea
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• v.53 no.2
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• pp.115-126
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• 2016

In the process of ship building, it is known that the maintenance of working period and saving cost are one of the important part during the logistics of blocks transportation. Precise operational planning inside the shipyard plays a big role for a smooth transportation of blocks. But many problems arise in the process of block transportation such as the inevitable road damage during the transportation of the blocks, unpredictable stockyard utilization of the road associated with a particular lot number, addition of unplanned blocks. Therefore, operational plan needs to be re-established frequently in real time for an efficient block management. In order to find the shortest path between lot numbers, there are several representative methods such as Floyd algorithm that has the characteristics of many-to-many mapping, Dijkstra algorithm that has the characteristic of one-to-many mapping, and the A* algorithm which has the one-to-one mapping, but many authors have published without the mutual comparisons of these algorithms. In this study, some appropriate comparison have been reviewed about the advantages and disadvantages of these algorithms in terms of precision and cost analysis of calculating the paths and planning system to operate the transporters. The flexible operating plan is proposed to handle a situation such as damaged path, changing process during block transportation. In addition, an operational algorithm of a vacant transporter is proposed to cover the shortest path in a minimum time considering the situation of transporter rotation for practical use.

• Korea journal of population studies
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• v.11 no.2
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• pp.67-76
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• 1988

The purpose of this study was to find out the factors affecting birth sex ratio which had revealed alarmingly higher in recent years. This study was conducted to get hold of the basic data such as the sex ratio of live births which had been delivered at 5 general hospitals in Taegu from 1982 to 1986. And author chose Dongsan Medical Center from those 5 hospitals for further detailed study, and reviewed 1,286 medical records of mothers who had birth in each February and March from 1984 to 1987. Of these 1,286 deliveries, 30 cases were twin deliveries, which added the total children numbers to 1,316. The findings of this study were as follows: The average of birth sex ratio( 114.5) for 5 years at five general hospitals in Taegu was slightly higher than the traditional birth sex ratio( 102-107) and the highest was 123.4 in 1985. There was no significant difference in birth sex ratio by mother's educational level, her religion nor father's occupation. The birth sex ratio of the cases whose mother was above 35 years old was significantly high(400.0), that of the cases who were born to the mothers who had more than 3rd parity was significantly high(309.5), and that of the cases whose mother had more than two daughters and no son was also significantly high (330.7). The birth sex ratio of the cases who did not have ultrasonogram on their prenatal visits was 87.8. In contrast to this, that of the cases who had ultrasonogram was significantly higher( 135.5). Of the mothers who have more than two daughters and no son' 80.4% (45 cases) had ultrasonogram and their newborn's birth sex ratio was significantly high(542.9). Of the cases who were born to more than 3rd parity mothers, 75.6%(65 cases) of their mothers had ultrasonogram and their sex ratio was significantly high(441.6). It was revealed by this study that the birth sex ratio is changed to significantly high due to sex confirmation of the fetus by ultrasonogram. Thus it is recommended that the value related to having equality of sexes must be ingrained by changing the various social systems and value systems which is now aggrevating the son preference and should provide controlling system which can prohibit the ultrasonogram for sex confirmation only.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.3
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• pp.55-65
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• 2019

Although crack on concrete exists from its early formation, crack requires attention as it affects stiffness of structure and can lead demolition of structure as it grows. Detecting cracks on concrete is needed to take action prior to performance degradation of structure, and deep learning can be utilized for it. In this study, transfer learning, one of the deep learning techniques, was used to detect the crack, as the amount of crack's image data was limited. Pre-trained Inception-v3 was applied as a base model for the transfer learning. Web scrapping was utilized to fetch images of concrete wall with or without crack from web. In the recognition of crack, image post-process including changing size or removing color were applied. In the visualization of crack, source images divided into 30px, 50px or 100px size were used as input data, and different numbers of input data per category were applied for each case. With the results of visualized crack image, false positive and false negative errors were examined. Highest accuracy for the recognizing crack was achieved when the source images were adjusted into 224px size under gray-scale. In visualization, the result using 50 data per category under 100px interval size showed the smallest error. With regard to the false positive error, the best result was obtained using 400 data per category, and regarding to the false negative error, the case using 50 data per category showed the best result.

• Clinical and Experimental Reproductive Medicine
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• v.49 no.1
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• pp.16-25
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• 2022

In mammalian species, females are born with a number of oocytes exceeding what they release via ovulation. In humans, an average girl is born with over a thousand times more oocytes than she will ovulate in her lifetime. The reason for having such an excessive number of oocytes in a neonatal female ovary is currently unknown. However, it is well established that the oocyte number decreases throughout the entire lifetime until the ovary loses them all. In this review, data published in the past 80 years were used to assess the current knowledge regarding the changing number of oocytes in humans and mice, as well as the reported factors that contribute to the decline of oocyte numbers. Briefly, a collective estimation indicates that an average girl is born with approximately 600,000 oocytes, which is 2,000 times more than the number of oocytes that she will ovulate in her lifetime. The oocyte number begins to decrease immediately after birth and is reduced to half of the initial number by puberty and almost zero by age 50 years. Multiple factors that are either intrinsic or extrinsic to the ovary contribute to the decline of the oocyte number. The inflammation caused by the ovulatory luteinizing hormone surge is discussed as a potential contributing factor to the decline of the oocyte pool during the reproductive lifespan.

• Korean Journal of Clinical Pharmacy
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• v.32 no.3
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• pp.155-165
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• 2022

Background: Chronic obstructive pulmonary disease (COPD) is not completely reversible and requires long-term management with appropriate treatment. This study aimed to analyze trends in treatment regimens and medication costs for COPD patients using a national claims database. Methods: We conducted this analysis using National Patient Sample data from the Health Insurance Review and Assessment Service covering the period from 2015 to 2018. We have constructed a dataset comprising COPD disease classification codes J43.x and J44.x (based on KCD-7 code, J43.0 was excluded) and compiled a list of drugs fitting current guidelines. To identify trends, we calculated frequency, ratio, and compound annual growth rate (CAGR) using the numbers of prescriptions and patients. Results: The number of COPD patients was 7,260 in 2018, slightly decreased from 2015. Most of these COPD patients were aged 60 or older and included a high proportion of males (72.2%; 2018). The number of patients prescribed inhaled medications increased gradually from 2015 to 2018 (9,227 (47.1%); 2015, 9,285 (51.5%); 2018), while the number of patients prescribed systemic beta-agonists and Xanthines has decreased since 2015 (CAGR -14.7; systemic beta-agonist, -5.8; Xanthines). The per capita cost of medication has increased by 0.4% (KRW 206,667; 2018, KRW 204,278; 2015) annually during the study period. Conclusion: This study showed that treatment with inhaled medications had continuously increased in accord with changing guidelines, but oral medications were still widely used. It is necessary to emphasize the importance of inhaled medications in treating COPD to reduce additional economic burden through appropriate medication use.

• 한국정보교육학회:학술대회논문집
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• 2021.08a
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• pp.275-281
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• 2021

Much of our lives are closely related to artificial intelligence, and society is changing more rapidly. Reflecting this era, the need for artificial intelligence education has emerged and various learning methods have been proposed, but guidance on artificial intelligence teaching and learning activities for lower grades elementary school students is insufficient. Therefore, in this study, the data collection education program for the lower grades of elementary school was developed based on the contents standards of the Korea Foundation for the Advancement of Science & Creativity. Focusing on the principles of artificial intelligence and the detailed data area of the utilization area, the focus was on expressing numbers and letters in various ways, such as colors and pictures, and finding various types of data in life to learn the principles of artificial intelligence. Through this program, it is expected that lower-grade elementary school students will be able to understand the importance of data collection in artificial intelligence through the process of knowing about data and collecting sound, picture, and text data.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.673-673
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• 2015

Earthwork is an operation that provides space for structures, and it takes up a large portion of the construction costs in a construction project. In large-scale earthwork, numerous types of construction equipment are used in the operation. The types of equipment should be selected based on the field conditions and the construction methods. These construction vehicles are constantly changing positions during the earthwork operation. Therefore, the equipment operators require effective communication to ensure the efficiency of the earthwork operation. All equipment operators should exchange information with the other equipment operators. Information should be exchanged continuously to support decision making and increase productivity during the earthwork operation at the construction site. This paper investigates the attributes required for an information interface between construction vehicles during an earthwork operation. This paper 1) discusses the importance of an information interface for construction vehicles in order to increase productivity during an earthwork operation, 2) analyses the types of attributes that need to be communicated between construction vehicles, and 3) provides a database that has been built for attribute control. The database built for the information interface between construction vehicles will enhance communication between vehicle operators. Table I shows the typical attributes that should be shared between the excavator operator and the dump truck operator. This information needs to be shared among the operators, as it helps them to plan the earthwork operation in a more efficient manner. A database has been developed to store this information in an entity relation diagram. A user-interface display environment is also developed to provide this information to the operators in the construction vehicles. The proposed interface can help exchange information effectively and facilitate a common understanding during the earthwork operation. For example, the vehicle operators will be aware of the planned volume, excavated volume, transportation time, and transportation numbers. As a part of this study, mobile devices, such as mobile phones and google glasses, will be used as hands-on communication tools.

• Journal of dental hygiene science
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• v.24 no.1
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• pp.29-36
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• 2024

Background: This study aimed to investigate whether there is a difference in organizational member attitudes by workplace environment and workplace types in dental hygienists working at dental health centers. Methods: A face-to-face survey or online survey was administered to dental hygienists working at dental health centers, and a total of 95 subjects were included. The survey includes 13 items to ask factors affecting employee's job satisfaction. Also, some questions were included to assess perception of organizational member attitude: five about organizational citizenship behavior, two about innovative behavior, and four about organizational commitment. Results: Dental hygienists working at dental clinics were more satisfied with their incomes and numbers of working days, while those from dental university hospitals and general hospitals were more satisfied with education support. In addition, hygienists working at dental hospitals were more satisfied with job autonomy, individual work capability, safe working environment, personal relation, potential for personal development, and positive labor-management relations, compared to those working at general and university hospitals (p<0.05). Among the items about perception of organizational member attitudes, the scores of items about organizational citizenship behaviors were higher, whereas the scores of items about innovative behaviors were relatively lower. Individuals working at dental hospitals than those working at general and university hospitals, chiefs and team and department leaders than team members, and those with increased satisfaction with current workplace had more positive perception of organizational member attitudes. Conclusion: For dental hygienists to have positive attitudes as organizational members, working environment should be improved, and executives of dental healthcare centers should pay attention to improving job satisfaction of organizational members. Moreover, since dental hygienists need to improve their perception of innovative behaviors and citizenship behaviors to strengthen specialty of dental hygienists in a changing dental healthcare, relevant training should be addressed in refresher courses or school programs.

• Journal of the Korean Society of School Health
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• v.9 no.1
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• pp.109-123
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• 1996

The study was designed to gain necessary basic data, in order to grasp the actual condition on personal hygiene of primary school students and to help school health education and child health education data development of parents of students, the survery was carried out through this reporter's interview for mothers who have primary school pupil in KyungBug area during the period of a month from 14 the April to 30 the April 1994. The results of this study can be summarized as follows. 1. As for general characteristics, the percent of answer mothers with 30~34 years 44.9%, and the percent of answer mothers with 35~39 years was 37.6%, 14.6% of answer mother was 40 years and over. The most house types was apartment house, that is 64.8% and independence house was 18.9%, 13.7% of answer mothers was multivalent house residents. As for level of school career, the percent of high school was 64.2% and the percent of university was 20.5%, 10.1% of answer mothers was finishment of middle school. As for religion a lack of religion was 38.4% and a Buddhist was 36.8%, a christian was 13.4%, 10.4% of answer mothers was a catholic. As for jobs, the percent of office was 33.9%, specialist and expert skiller was 17.3%, self-management was 16.0%, fishing and agrarian villiages was 11.6%, public service personnel and shool personnel was 9.1%. As for the number of sons and daughters, the percent of two was 70.5%, the percent of one was 16.0%, and the percent of male students was 54.1%. As for level of economic life middle level was 59.9%. 2. The percentage of washing hand after school hours was 66.8% and not washing hand after school hours was 33.2%. In washing hand after school hours family of independence house, mothers that have schoolcareer of university, female students, three and over of sons and daughters was high individually (p<0.05). 3. As for paring one's nails, once a ten days was 52.9% once a five days was 22.5% once a fifteen days was 19.0%, once a twenty and over was 5.6%. 4. 54.7% of primary school students of answer mother's take a bath once a few days and 31.6% take a bath once a week, 10.1% take a bath once a tendays. 5. The percentage of changing of underwear once a day was 60.9%, once a few days was 37.1%, once a week was 2.0%, as for changing of underwear, sons and daughters that has mothers with 29 years and downward, one number of sons and daughters, females students was high individually (p<0.01). 6. The percentage of haircut once a 20~30 days was 59.9%, once a 31~40 days was 17.9%, once a 40 days and over was 16.6%. As for the percentage of haircut once a 20~30 days apartment house residents, male students was high (p<0.01). 7. The percentage of experience in taking nutrition was 79.8% and the percentage of experience in taking restorative was 72.3%. As for taking nutrition, apartment house residents, one number of sons and daughters, male students was high individually (p<0.01). As for taking restorative apartment house residents, on number of sons and daughters, male students was high individually (p<0.05). 8. The percentage of habit of unbalanced diet was 44.0%, sons and daughters that have mother with 40 years and over apartment house residents, male students, one number of sons and daughters was high indivdually (p<0.05). 9. As for hygiene condition of sons and daughters, the percentage of good state of health was 65.2%, middle state of health was 3.5% bad state of health was 11.4%. In good state of health sons and daughters that have mothers with 29 years and downward, multivalent house residents, three numbers of sons and daughters, female students, high birth was high individually. 10. As for fattness of sons and daughters, existence was 18.2%. No existence was 81.8%. in existence sons and daughters who have mothers with 40 years and downward, independence house resident, special job and expert skill job, three and over number of sons and daughters, female students, low birth was high individually. 11. As for use aspect of medical facilities of sons and daughters, hospital doctors was 53.1%, drugstore was 42.3%, chinese medicine hospitals or health organization was 4.6%. In usage of drugstore, sons and daughters of mothers with 29 years, 40 years and over was 55.6%, 61.4% individully, inusage of hospital doctors 30~34 years, 34~39 tears was 64.5%, 49.1% individully (p<0.01), apartment house residents, one or two numbers of sons and daughters, male students was high individually. In the percentage of using drugstore, school career of middle school and downward, in occupation, three and over numbers of sons and daughters, low birth was high individually (p<0.05). According to the results mentioned above. An actual condition and a related matters on personal hygiene of primary school students must be used as the basis data of a health education program and a health data of a health education program and a health data related, a teaching materials development and must be helped to the health life education of parents of students and childs.