• Geomechanics and Engineering
• /
• v.1 no.4
• /
• pp.307-321
• /
• 2009

The paper employs a feed forward neural network with back-propagation algorithm for modeling time dependent swell in clays containing carbonate in the presence of sulfuric acid. The oedometer swell percent is estimated at a nominal surcharge pressure of 6.25 kPa to develop 612 data sets for modeling. The input parameters used in the network include time, sulfuric acid concentration, carbonate percentage, and liquid limit. Among the total data sets, 280 (46%) were assigned to training, 175 (29%) for testing and the remaining 157 data sets (25%) were relegated to cross validation. The network was programmed to process this information and predict the percent swell at any time, knowing the variable involved. The study demonstrates that it is possible to develop a general BPNN model that can predict time dependent swell with relatively high accuracy with observed data ($R^2$=0.9986). The obtained results are also compared with generated non-linear regression model.

• Journal of Welding and Joining
• /
• v.16 no.5
• /
• pp.48-55
• /
• 1998

This study was undertaken to investigate the friction welding of A2024-T6 aluminum alloy and SM45C carbon steel using insert metals. The relationships among the friction welding conditions, the tensile strength of joints, the hardness distribution of welds, the microstructure of welds and the tensile fracture surfaces were mainly investigated through this experiment. When the A6063-T5 aluminum alloy of insert metal was used, the maximum tensile strengh of joint was obtained. In this case, the maximum joint efficiency was 75.3 percent and in the case of unusing the insert metals, it was 37.7 percent. Optimal welding conditions were N=2000rpm, P$_1$=40MPa, P$_2$=140MPa, t$_1$=1.0sec and t$_2$=5sec.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.26 no.2
• /
• pp.59-68
• /
• 1984

The Purpose of this study was to investigate the effect of the change in misture content on some physical properties of grains, and some relations amont the properties. Materials included ere rough rice, brown rice, barley and wheat with the range of moisture content of 6~26 percent, 7~25 percent, 10~24 percent and 6~22 percent, respectively. Kernel dimension, sphericity, kernel weight, and volume were included as the physical properties of the grains. The results obtained are summarized as follows; 1. The ratio of grain length to the thickness was in the range of 3.59~4.16 for rough rice(Indica type), 2.98~3.27 for rough rice(Japonica type), 3.25 for brown rice (I.T.), 2.14~2.38 for brown rice(J.T.), 2.92~3.13 for barley and 2.10~2.21 for wheat, respectively. 2. The sphericity was found to be 42 percent for rough rice(I.T.), 48 percent for rough rice(J.T.), 52 percent for brown rice(I.T.), 62 percent for brown rice(J.T.), 45 percent for barley and 61 percent for wheat, respectively. 3. The kernel weight of grains was linealy increased with the increase of moisture content. At a specified moisture centent of 14 percent, the kernel weight was shown to be in the range of 4.72${\times}10^{-5}$~3.58${\times}10^{-5}$kg for wheat, 3.60${\times}10^{-5}$~3.12${\times}10^{-5}$kg for barley, 2.80${\times}10^{-5}$~2.35${\times}10^{-5}$kg for rough rice, and 2.24${\times}10^{-5}$~1.82${\times}10^{-5}$kg for brown rice, respectively. 4. The kernel volume was linearly increased with increase of moisture content. The rate of increase was significantly low for rough rice in comparison with the remaining grains. The kernel volume, at a specified moisture content of 14 percent, was in the range of 3.51${\times}10^{-8}$~2.76${\times}10^{-8}m^3$ for wheat, 2.84${\times}10^{-8}$~2.43${\times}10^{-8}m^3$ for barley, 2.93${\times}10^{-8}$~1.97${\times}10^{-8}m^3$ for rough rice, and 1.61${\times}10^{-8}$~1.29${\times}10^{-8}m^3$ for brown rice, respectively. 5. The kernel volume of grains was found to be related to the length, width, thickness and kernel weight as a exponential function. The kernel volume was shown to have correlation coefficient to the length factor rough rice and barley which were of low sphericity, while the width factor was predominant for brown rice and wheat which was of high sphericity.

• Journal of Technology Innovation
• /
• v.11 no.1
• /
• pp.99-123
• /
• 2003

This study aims to explore the patterns of various innovation policies pursued by local governments in Korea. We surveyed and analyzed 16 regions at the county level and 7 ministries at the central government. It was found from the analysis that there are 719 policy programs having been enacted including some overlaps among 16 regions. 3,369 billion won in total were spent on the policy programs in 2002, of which 36.7 percent was contributed by the central government, 46.4 percent by local governments and remaining 16.8 percent by private partners who may have benefits from the policy programs. It was discovered that support programs for basic research and applied research activities were rare having small budget size, due to the lack of the importance of R&D activities in regional development and budget constraint of local governments. Technology sharing policies, particularly networks and technology transfer are the most underdeveloped one among types of innovation policies. Based upon the results of our analysis, we recommend that budget allocation, associated with science and technology, to local governments should be increased so that they can expand the support scale of existing program: as well as design new types of innovation policies.

• Tuberculosis and Respiratory Diseases
• /
• v.39 no.4
• /
• pp.361-365
• /
• 1992

Lymphangiomas are rare benign shlow-growing tumors composed of lymphatic channels. They are generally classified according to the size of their lymph channels as simple, cavernous, and cystic lymphangioma or cystic hygroma. The simple and cavernous types usually occur in the head, neck or axillae. About 75 percent of cystic lymphangioma occur in the neck and 20 percent in the axillae, the remaining 5 percent occur in the mediastinum, omentum, pelvis, groin, spleen, bone, and skin, etc. Purely mediastinal cystic lymphangiomas are very uncommon. We report a case of purely mediastinal cystic lymphangioma confirmed pathologically and treated by operation, along with a review of the literature.

• Proceedings of the IEEK Conference
• /
• 2003.07e
• /
• pp.2263-2266
• /
• 2003

Three-dimensional face recognition algorithm using curvature information representing characteristics of surface form is suggested. The experiment showed more than 90 percent of recognition for the noses which had definite change value of data, and contained much information about surface curvature. Recognition ratio using a contour taken from the remaining part other than the eyes, noses, mouths which are the main components of faces showed the important role, which could be used as the important index information in the three-dimensional face recognition.

• Journal of Preventive Medicine and Public Health
• /
• v.43 no.3
• /
• pp.265-273
• /
• 2010

Objectives: Due to the economic crisis and globalization, many workers have been suffering from severe occupational stress due to job insecurity and struggles related to downsizing and restructuring. This study aims to assess the stress levels among workers involved in fierce labor disputes and massive layoffs and to evaluate their specific needs and satisfaction with counseling services set up to help workers cope with severely stressful situations? Methods: The authors provided crisis intervention to workers in traumatic situations to compare the differential level of stress responses and needs among the workers remaining employed in a large auto factory, those laid off by it, and those laid off by other companies in the same region (Pyeongtaek, Gyeonggi Province). We measured stress levels using the worker's stress response inventory (WSRI) and heart rate variability (HRV), and assessed workers' satisfaction with the counseling services. Results: 502 workers participated in the program. Fifty-seven percent of them consulted with occupational problems. The mean WSRI score of the workers remaining employed in the automobile factory was higher than that of the unemployed (employed: $39.8{\pm}19.9$ unemployed: $29.3{\pm}18.8$). Ninety-five percent of workers responded that they were satisfied or very satisfied with the counseling services. Conclusions: This study suggests the urgent need for the establishment of a national crisis intervention program dedicated to supporting workers in severely stressful situations.

• Journal of Korean society of Dental Hygiene
• /
• v.3 no.2
• /
• pp.157-168
• /
• 2003

The purpose of this study was to examine the relationship of oral state and health condition among elderly people. The subjects in this study were 220 senior citizens who were randomly selected from among dwellers in Eunpyeong-gu and Jongno-gu, Seoul. A survey was conducted by one-on-one interview to find out their oral state and health condition. The collected data were analyzed with SPSS 10.0 program, and variance analysis, correlation analysis and regression procedure were employed. The findings of this study were as follows: First, Regarding subjective oral health state, 52.3 percent of the elderly people, more than the half, considered their mouth to be in good health. The number of their mean remaining permanent teeth was 14.85, which was one of the indexes to indicate their objective oral state. Second, Concerning their abnormal oral health experience, 75 percent didn't feel that their masticatory force was good enough, and 55.9 percent felt pain in their teeth, 70.0 percent suffered from mouth dryness. Those fact showed that a lot of the elderly people felt there was something wrong with their oral cavity, and the unhealthy oral state made it difficult for them to eat food, as their masticatory force weakened and they couldn't get a good taste for food. Third, Those who viewed their oral cavity as healthy thought that they were in good shape, and there was a significant correlational relationship between their subjective oral and overall physical health states. Their own perception of oral state made a difference to their subjective health status, and the subjective oral health was significantly related to ADL as well, which implied that their ADL was different according to the way they looked at their own oral health status.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.25 no.2
• /
• pp.458-466
• /
• 1998

Non-odontogenic tumors can be classified as malignant or benign. Most oral tumors in children are benign. In the Belfast series only 7.5 percent of soft tissue tumors were malignant and Bhaskar(l963) found only 9 percent of 293 oral tumors of all kinds to be malignant. Benign tumors may be classified as epithelial and mesenchymal. The most common tumor of surface epithelium is the squamous papilloma. These are easily recognized clinically as cauliflower-like lesions. Fibrous lesions are very common in children's mouths. Many of these are not true neoplasms but are related to fibrous hyperplasia. Another common oral tumor in children is angiomatous tumors. Hemangioma occurred more frequently than lymphangioma. Cystic hygroma, a cystic subtype of lymphangioma, is a developmental tumor of lymphatic origin. It is a considered to be a relatively rare lesion. About 50 percent of cystic hygroma are present at birth, and most of the remaining 50 percent appear in the early years of life during the period of active lymphatic growth. The preferred treatment for these lesions, except for hemangioma, is complete surgical excision. With proper surgical techniques, recurrence is not expected.

• Journal of Yeungnam Medical Science
• /
• v.21 no.1
• /
• pp.51-59
• /
• 2004

Background: The objective of this study is to evaluate the relationship between chewing ability and health status in order to provide basic information for the development of program which may lead to an improvement of a the elderly health status in urban areas. Materials and methods: The subjects of this study were 128 elderly urban female over the age of 65 who reside at house. The data were collected from May 21 to August 20, 2001, through questionnaires about nutrient intake status, direct measurement of anthropometrics, and oral examinations. Results: In terms of remaining teeth, there was significant negative relationship between age and number of remained teeth. The average number of remained teeth our subjects was $13.1{\pm}10.6$. About sixty five percent of the subjects were denture users (partial or full dentures) and there was positive relationship between age and the percentage of denture user. There was a significant negative correlation between age and chewing ability. The group that was able to chew had more remained teeth than the other group. Conclusion: This study suggests that there is strong positive relationship between chewing ability (remaining teeth) and elderly health status in urban areas, and the importance of preserving original teeth to improve the elderly health status in the public health program.