• Journal of Biomedical Engineering Research
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• v.25 no.4
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• pp.261-268
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• 2004

Osteoporosis is a clinical condition in which the amount of bone tissue is reduced and the likelihood of fracture is increased. It is known that the electrical property of the bone is related to its density, and, in particular, the electrical resistance of the bone decreases as the bone loss increases. This implies that the electrical property of bone may be an useful parameter to diagnose osteoporosis, provided that it can be readily measured. The study attempted to evaluate the electrical conductivity of bone using a technique of electrical impedance tomography (EIT). It nay not be easy in general to get an EIT for the bone due to the big difference (an order of 2) of electrical properties between the bone and the surrounding soft tissue. In the present study, we took an adaptive mesh regeneration technique originally developed for the detection of two phase boundaries and modified it to be able to reconstruct the electrical conductivity inside the boundary provided that the geometry of the boundary was given. Numerical simulation was carried out for a tibia phantom, circular cylindrical phantom (radius of 40 mm) inside of which there is an ellipsoidal homeogenous tibia bone (short and long radius are 17 mm and 15 mm, respectively) surrounded by the soft tissue. The bone was located in the 15 mm above from the center of the circular cross section of the phantom. The electrical conductivity of the soft tissue was set to be 4 mS/cm and varies from 0.01 to 1 ms/cm for the bone. The simulation considered measurement errors in order to look into its effects. The simulated results showed that, if the measurement error was maintained less than 5 %, the reconstructed electrical conductivity of the bone was within 10 % errors. The accuracy increased with the electrical conductivity of the bone, as expected. This indicates that the present technique provides more accurate information for osteoporotic bones. It should be noted that tile simulation is based on a simple two phase image for the bone and the surrounding soft tissue when its anatomical information is provided. Nevertheless, the study indicates the possibility that the EIT technique may be used as a new means to detect the bone loss leading to osteoporotic fractures.

• Journal of Korean Foot and Ankle Society
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• v.20 no.4
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• pp.163-169
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• 2016

Purpose: To investigate the measured values of the talus in Koreans. Materials and Methods: We measured 88 tali from 44 cadavers that have been donated between December 2012 and December 2015. Of the cadavers, 27 were male and 17 were female. Their mean age was 73 years. The length and width of the talus were measured using a digital goniometer and vernier caliper. Results: The values of cadaveric measurement, mean maximal width and length, width and length of the dome anterior, width and length of the posterior facet, height and length of the trochlear medial facet, and height and length of the trochlear lateral facet were $43.6{\pm}2.6mm$, $56.5{\pm}3.3mm$, $32.5{\pm}2.0mm$, $42.2{\pm}2.7mm$, $22.2{\pm}2.2mm$, $34.7{\pm}2.0mm$, $15.3{\pm}1.3mm$, $33.3{\pm}2.9mm$, $25.3{\pm}3.3mm$, and $30.8{\pm}2.4mm$ for men and $38.9{\pm}1.6mm$, $53.6{\pm}2.4mm$, $27.9{\pm}2.1mm$, $37.4{\pm}3.2mm$, $20.6{\pm}0.8mm$, $31.9{\pm}1.2mm$, $13.6{\pm}2.6mm$, $28.4{\pm}2.5mm$, $24.9{\pm}2.1mm$, and $28.9{\pm}1.4mm$ for women, respectively. The size of the talus showed an accuracy of 86% when anteroposterior diameter was greater than 59 mm. A difference in the size of the right and left talus was not observed. The mean inclination and declination angles were $24.4^{\circ}{\pm}4.2^{\circ}$ and $28.2^{\circ}{\pm}5.4^{\circ}$ for men, and $24.6^{\circ}{\pm}3.6^{\circ}$ and $24.7^{\circ}{\pm}6.7^{\circ}$ for women (p=0.980, p=0.018), respectively, at least $15^{\circ}$, which showed a big difference for every object up to $37^{\circ}$. Conclusion: This paper, to the best of our knowledge, is the first study to measure the talus in Koreans. There were differences by gender and ethnicity in the in measured talus values. The measurements were smaller than European-Americans and greater than Japanese.

• Journal of Intelligence and Information Systems
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• v.21 no.1
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• pp.1-13
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• 2015

As opinion mining in big data applications has been highlighted, a lot of research on unstructured data has made. Lots of social media on the Internet generate unstructured or semi-structured data every second and they are often made by natural or human languages we use in daily life. Many words in human languages have multiple meanings or senses. In this result, it is very difficult for computers to extract useful information from these datasets. Traditional web search engines are usually based on keyword search, resulting in incorrect search results which are far from users' intentions. Even though a lot of progress in enhancing the performance of search engines has made over the last years in order to provide users with appropriate results, there is still so much to improve it. Word sense disambiguation can play a very important role in dealing with natural language processing and is considered as one of the most difficult problems in this area. Major approaches to word sense disambiguation can be classified as knowledge-base, supervised corpus-based, and unsupervised corpus-based approaches. This paper presents a method which automatically generates a corpus for word sense disambiguation by taking advantage of examples in existing dictionaries and avoids expensive sense tagging processes. It experiments the effectiveness of the method based on Naïve Bayes Model, which is one of supervised learning algorithms, by using Korean standard unabridged dictionary and Sejong Corpus. Korean standard unabridged dictionary has approximately 57,000 sentences. Sejong Corpus has about 790,000 sentences tagged with part-of-speech and senses all together. For the experiment of this study, Korean standard unabridged dictionary and Sejong Corpus were experimented as a combination and separate entities using cross validation. Only nouns, target subjects in word sense disambiguation, were selected. 93,522 word senses among 265,655 nouns and 56,914 sentences from related proverbs and examples were additionally combined in the corpus. Sejong Corpus was easily merged with Korean standard unabridged dictionary because Sejong Corpus was tagged based on sense indices defined by Korean standard unabridged dictionary. Sense vectors were formed after the merged corpus was created. Terms used in creating sense vectors were added in the named entity dictionary of Korean morphological analyzer. By using the extended named entity dictionary, term vectors were extracted from the input sentences and then term vectors for the sentences were created. Given the extracted term vector and the sense vector model made during the pre-processing stage, the sense-tagged terms were determined by the vector space model based word sense disambiguation. In addition, this study shows the effectiveness of merged corpus from examples in Korean standard unabridged dictionary and Sejong Corpus. The experiment shows the better results in precision and recall are found with the merged corpus. This study suggests it can practically enhance the performance of internet search engines and help us to understand more accurate meaning of a sentence in natural language processing pertinent to search engines, opinion mining, and text mining. Naïve Bayes classifier used in this study represents a supervised learning algorithm and uses Bayes theorem. Naïve Bayes classifier has an assumption that all senses are independent. Even though the assumption of Naïve Bayes classifier is not realistic and ignores the correlation between attributes, Naïve Bayes classifier is widely used because of its simplicity and in practice it is known to be very effective in many applications such as text classification and medical diagnosis. However, further research need to be carried out to consider all possible combinations and/or partial combinations of all senses in a sentence. Also, the effectiveness of word sense disambiguation may be improved if rhetorical structures or morphological dependencies between words are analyzed through syntactic analysis.

• Health Policy and Management
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• v.10 no.3
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• pp.19-49
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• 2000

This study was conducted to help staff members of health centers manage personnel by examining the staff members' recognition level of organization structure of health centers, their motivation, their job satisfaction level and its related factors. Data were collected from 471 staff members of 14 health centers from March 3, 1999 to April 30, 1999. The results of this study are summarized as follows. In recognition levels of organization structure of health centers, the recognition level of necessity of discretion right was highest(3.55 points on the base of 5 points), while the recognition level of the location of decision making right was lowest(2.77 points). The general recognition of organization structure of health centers was 3.06 points, the suitability of division of duties was 3.05 points, and the optimum of manpower and budget was 2.93 points. The staff members' general recognition level of the organization structure appeared significantly higher in case of the groups of small and medium sized cities, above fifties, below high school graduate, above the sixth grade, public service experience of above 20 years, service period of below 2 years at present post, and average monthly salary of one million, eight hundred and ten thousand won. In the recognition level of the location of decision making right, the groups of big cities, male, the married, above the sixth grade, health and administration posts, average monthly salary of one million, three hundred and ten thousand won to one million, and eight hundred thousand won were significantly higher than the other groups. The recognition level of necessity of discretion right was higher in case of the groups of the twenties, the unmarried, above college graduate, nursing post, public service experience of below 5 years, service period of below 2 years at present post, and average monthly salary of below eight hundred thousand won. In the recognition level of suitability of division of duties, the groups of small and medium sized cities, the married, medical technicians, public service experience of above 20 years, and service period of below 4 years at present post were significantly higher than the other groups. In the staff members' recognition levels of organization management, the recognition level of opinion response when making decision was highest(2.92 points). The recognition level of rationality of the target amount establishment method was 2.88 points and the recognition level of personnel management was 2.63 points. The recognition level of personnel management was significantly higher in case of the groups of small and medium sized cities, the forties, above the sixth grade, medical technicians, public service experience of above 20 years, service period of below 2 years at present post, and average monthly salary of above one million, eight hundred and ten thousand won. In the recognition level of opinion response when making decision, the groups of small and medium sized cities, female, the eighth grade, health and administration posts, and service period of below 2 years at present post were higher than the other groups. The recognition level of rationality of the target amount establishment method was significantly higher in case of the groups of above fifties, below high school graduate, above the sixth grade, medical service post, and public service experience of 15 to 20 years. The factors significantly influencing sanitation were sex, education level, the period of public service experience, general recognition of organization structure, recognition of necessity of discretion right, recognition of suitability of division of duties, and recognition of opinion response when making decision. The factors which significantly influenced motivation were marital status, grade, recognition of the location of decision making right, recognition of necessity of discretion right, recognition of division of duties, recognition of opinion response when making decision, and sanitation. Sex, education level, recognition of suitability of division of duties, recognition of the target amount establishment method, and motivation influenced job satisfaction significantly. The factors significantly influencing organization culture were age, the period of public service experience, service period at present post, recognition of optimum of manpower and budget, recognition of suitability of division of duties, recognition of opinion response when making decision, and recognition of rationality of the target amount establishment method. In the coming days, the staff members' job satisfaction level must be increased through motivation and efficient conduct of duty must be accomplished through rational organization structure and management. Moreover, change of the staff members' consciousness and administrative system which are suitable for local autonomy system have to be established with increase of local residents' consciousness level and education level. Forming organization culture by reformative idea which fits the new era, public health service by the Community Health Act and health education service by the Health Promotion Act must be carried out efficiently. In doing so, financial support of central government and active efforts and concerns of local governments have to be devoted in order to get public health service in which peculiarity of the community is considered to be pursued well.