• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.102-107
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• 2012

Purpose : Because of the rapid physical decay of the short half-lived radionuclide, counting of event for image is very limited. In this reason, long scan duration is applied for more accurate quantitative analysis in the relatively low sensitive examination. The aim of this study was to evaluate the difference according to scan duration and investigate the resonable scan duration using the radionuclide of 11C and 18F in PET scan. Materials and Methods : 1994-NEMA Phantom was filled with 11C of $30.08{\pm}4.22MBq$ and 18F of $40.08{\pm}8.29MBq$ diluted with distilled water. Dynamic images were acquired 20frames/1minute and static image was acquired for 20minutes with 11C. And dynamic images were acquired 20frames/2.5minutes and static image was acquired for 50minutes with 18F. All of data were applied with same reconstruction method and time decay correction. Region of interest (ROI) was set on the image, maximum radioactivity concentration (maxRC, kBq/mL) was compared. We compared maxRC with acquired dynamic image which was summed one bye one to increase the total scan duration. Results : maxRC over time of 11C was $3.85{\pm}0.45{\sim}5.15{\pm}0.50kBq/mL$ in dynamic image, and static image was $2.15{\pm}0.26kBq/mL$. In case of 18F, the maxRC was $9.09{\pm}0.42{\sim}9.48{\pm}0.31kBq/mL$ in dynamic image and $7.24{\pm}0.14kBq/mL$ in static. In summed image of 11C, as total scan duration was increased to 5, 10, 15, 20minutes, the maxRC were $2.47{\pm}0.4$, $2.22{\pm}0.37$, $2.08{\pm}0.42$, $1.95{\pm}0.55kBq/mL$ respectively. In case of 18F, the total scan duration was increased to 12.5, 25, 37.5, and 50minutes, the maxRC were $7.89{\pm}0.27$, $7.61{\pm}0.23$, $7.36{\pm}0.21$, $7.31{\pm}0.23kBq/mL$. Conclusion : As elapsed time was increased after completion of injection, the maxRC was increased by 33% and 4% in dynamic study of 11C and 18F respectively. Also the total scan duration was increased, the maxRC was reduced by 50% and 20% in summed image of 11C and 18F respectively. The percentage difference of each result is more larger in study using relatively shorter half-lived radionuclide. It appears that the accuracy of decay correction declined not only increment of scan duration but also increment of elapsed time from a starting point of acquisition. In study using 18F, there was no big difference so it's not necessary to consider error of quantitative evaluation according to elapsed time. It's recommended to apply additional decay correction method considering decay correction the error concerning elapsed time or to set the scan duration of static image less than 5minutes corresponding 25% of half life in study using shorter half-lived radionuclide as 11C.

• Journal of the Korea Society of Computer and Information
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• v.25 no.3
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• pp.243-250
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• 2020

In this paper, we propose an effective software education scheme for universities. The key idea of this software education scheme is to analyze software curriculum of QS world university rankings Top 10, SW-oriented university, and regional main national university. And based on the results, we propose five improvements for the effective SW education method of universities. The first is to enhance the adaptability of the industry by developing courses based on the SW developer's job analysis in the curriculum development process. Second, it is necessary to strengthen the curriculum of the 4th industrial revolution core technologies(cloud computing, big data, virtual/augmented reality, Internet of things, etc.) and integrate them with various fields such as medical, bio, sensor, human, and cognitive science. Third, programming language education should be included in software convergence course after basic syntax education to implement projects in various fields. In addition, the curriculum for developing system programming developers and back-end developers should be strengthened rather than application program developers. Fourth, it offers opportunities to participate in industrial projects by reinforcing courses such as capstone design and comprehensive design, which enables product-based self-directed learning. Fifth, it is necessary to develop university-specific curriculum based on local industry by reinforcing internship or industry-academic program that can acquire skills in local industry field.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.1
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• pp.57-61
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• 2010

Objective: Second primary malignancy (SPM) that occur in various period and region are important factors that deteriorate long-term survival rate in patients who recovered from oral cancer. Researches such as chemoprevention are being tried to reduce occurrence of SPMs. Only if analysis of clinical features of patients who develop SPM such as period, region and factors precedes, adequate prevention and treatment of SPM is possible. But, there are few researches about clinical features of SPMs that have primary lesion in oral cavity. In this study, we analysis that occurrence rates, regions that happen, risk factors and effect to survival rates of 2nd primary malignancies in oral cancer patients. From this survey, we willing to collect basic data for prevention and early diagnosis of SPMs. Methods: The medical records of 139 patients of oral oncology clinic of National Cancer Center who had up to 2-years follow up records after surgical or radiological treatment due to squamus cell carcinoma of oral cavity were reviewed. In these patients, survey of occurrence rate of SPMs, duration, survival rate and risk factors about occurrence of SPMs such as history of smoking, body mass index, age, sex, stage of primary lesion and history of radiologic treatment were achieved. Results: There are 15 patients who developed SPM in 139 cases. The actual occurrence rate of SPM was 10.79% and SPM were more likely to occur in male patients with 11 male Vs 4 female patients. Median age of these patient is 61.47 within 32 to 74 range. The regions that develop SPM are oral cavities (2 cases), stomach (4 cases), esophagus (2 cases), lung (2 cases) and others (1 case each breast, larynx, cervix, liver and kidney). In addition, metachronous cancers were 11 cases which happened more common than 4cases of synchronous cancers. Surveys of risk factors that relate to development of SPMs, such as sex, age, history of radiologic treatment, body mass index, history of smoking and stage of primary disease were done. Among them, factor of sex is only appear statistically significant (P=0.001), but rest are not significant in statistically. Conclusion: Occurrence rates of SPMs were reported from 10% to 20% by precede study. In this study, occurrence rate of SPMs is 10.79% that is similar to results of precede research. In comparison of 5-yr survival rates of groups that develop SPMs or not, there is statistically significance between two groups. Present treatment modalities of SPMs are surgical operation, radiotherapy, chemotherapy and combination of these modalities. In choosing the treatment modality, we must consider the first treatment modality, region of primary disease, region of SPMs and general conditions of patient. Because development of SPMs have big effect on prognosis, prevention of SPMs must regard to important objective of treatments in patients of SCCa in oral cavity.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.4
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• pp.359-367
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• 2020

The aim of this study was to identify the association between candidiasis and early childhood caries and to investigate whether the experience of candidiasis or oral candidiasis before age 1 can be considered as a risk factor for early childhood caries. The database used in this study was provided by Health Insurance Review and Assessment Service. Medical records of children born from January 2010 to December 2012 were obtained, and those without dental records were excluded. Subjects were divided into several groups based on the experience of candidiasis or oral candidiasis before age 6: candidiasis group and non-candidiasis group; oral candidiasis group and non-oral candidiasis group. Another categorization was done according to the experience of candidiasis or oral candidiasis before age 1. The incidence rate of early childhood caries in each group were compared. The prevalence of dental caries in children who have been diagnosed with candidiasis or oral candidiasis before age 6 was significantly different from those who have not experienced candidiasis. Similarly, children who have suffered from candidiasis or oral candidiasis before age 1 had significantly different incidence of caries from the children without candidiasis experience.

• Journal of the Korean Society of Food Culture
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• v.5 no.3
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• pp.331-347
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• 1990

This study was designed under the purpose to analyze the Korean Traditional Folk Remedies on food, to submit the basic statistical data, and to utilize them by examining how much they know about the Korean Traditional Folk Remedies and also by examining how frequently they used them. The sample was consisted of 312 housewives living in Daegu, Kyungsan city and Kyungsan-eup, the survey was made by use of questionaires from July 15 to August 1 1989. The results are as follows 1. Analysis of Folk Remedical Contents 1) The method of the Folk Remedies used in this area was mainly food, which can be easily found around their house and easy to use, it was possible to apply scientific principles in some cases. 2) The major popular method was shown to feed boiled barley or brown rice which are known as the Folk Remedy for Diabetes. 3) The ANOVA of variable shows the significant influence on each object which age, religion, the level of education, job, monthly income, and the area except family formation. 2. The Frequency of Folk Remedies and additional analysis 1) The most frequently used Folk Remedy was Arterio-sclerosis(1.44), which is followed by the loss of Eyesight(1.40), Hang over(1.28), Couth(1.27), Cold(1.26) etc. 2) In the analysis of Pearson Correlation between frequencies of Folk Remedies used, and demographic variables such as age(p<.05), the monthly income(p<.01), in that area, total number of response items showed a positive correlation. 3. The source to learn about Folk Remedy. 1) It is acknoledged that they are mostly instructed by their forefathers, friends, neighbors, professional textbooks, mass communications, herb doctors, other medical sources or education at school etc. 2) The ANOVA of Variables shows the big differences between each group by age. Based on the above findings, the following suggestions are made ; Most of Korean Traditional Folk Remedies are recognized scientific and reasonable which are based on the scientific research and herb medicine therefore it should be made good use of for our life in good health additionally. I hereby insist that the importance of our Folk Remedies should be reviewed and focused for maintenance our health.

• The Journal of Korean Medicine
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• v.18 no.1
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• pp.126-142
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• 1997

For last four or five years, the number of Korean students have gone on increasing awfully. After the year 1997 when they will flow in, our field and government will be undergone a big shock and social problems. Therefore, thorough grasping and the method of provision is expeced to need. 1. The situation, According to the data published from the year 1993 to 1997, their results are great different. But recent Korean embassy in China examined the situation of the Korean students, whose result was investigated as follows: about 1500 persons, their average age is 24 to 44, the ratio of male and female students is 3 to 1, that of their academic background which is a graduate of university : that of college : that of highschool is 1.6 : 1 : 4.7, and that of their class attitude which is direct : common : indirect appears the percents 30.4 : 52.8 : 16.8. 2. The controversial points (1) A lowering of standards on Chinese medical treatment is expected by the imprudent studying abroad without qualification. And because of excessive production of herb doctors, the amount of treatment may be above people's demand. Besides owing to the impossibility of prediction on the number the counterplans of our government may fall into utler confusion. (2) The curriculum, the teaching schedule and contents are so different that the graduates seem not to be given real education of chinese medicine from the point of Korean view. (3) In the wrong national examination, the important thought of china, and the system of WTO in Korea, when China will become mighty rival above problems contain the negative sides. 3. The counterplans - what should be performed soon. (1) Illegal contents about studying abroadl in China ought to inform sidely that students might not go on increasing. Before they form nam-power, the government and the field of chinese medicine should cope with such a situation together. (2) The law of regulation about agents should be legislated and they should be surpervised. (3) The exact numbers of students, their situation, and the present condition of each university should be examined. (4) After investigating the problems of the present system of national test, its enforcement and many counterplans is requisite. (5) The cooperating confrontation with the conference of dentistry is in need. (6) Since the problems are possibility to be developed to diplomatic questions, the effort of both nations is needful. - what need middle of long time. (1) The effort that suppress the more establishment of the college of oriental medicine is necessary. (2) After comparing with the system of foreign test, the government should make the system of test in accord with the mutualism and the principle of indiscrimination among nations and cope with such a many issues thoroughly.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.4
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• pp.164-170
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• 2017

The CNC machine tool field is showing a growing trend with the recent rapid development of manufacturing industries such as semiconductors, automobiles, medical devices, various inspection and test equipment, mechanical metal processing equipment, aircraft, shipbuilding and electronic equipment. However, small and medium-sized machining companies that use CNC machine tools are experiencing difficulties in increasingly intense competition. Especially, small companies which are receiving orders from 3rd or 4th venders are very difficult in business management. In recent years, company S experienced difficulty to make product quality and delivery time due to the ignorance of the processing method when manufacturing cooling plate jig made of SUS304 material used for cell phone liquid crystal glass processing. In order to solve these problems, we redesigned the process according to the size of our company and tried to manage all processes with quantified data. In the meantime, we have found that there is a need to improve the cutter process, which accounts for most of the machining process. Therefore, we have investigated the correlation between RPM and FEED of three cutters that have been used in the past. As a result, we found that it is the most urgent problem to solve the roughing process during the cutter operation which occupies more than 70% of the total machining. In order to shorten the machining time and improve the quality in machining of SUS304 cooling plate jig, we select the main factors such as price, tool life, maintenance cost, productivity, quality, RPM, and FEED and use AHP to find the most suitable milling cutter. We also tried to solve the problem of delivery, quality and production capacity which was a big problem of S company through experiment operation with selected cutter tool. As a result, the following conclusions were drawn. First, the most efficient of the three cutters currently available in the machining center has proven to be an M-cutter. Second, although one additional facility was required, it was possible to produce the existing facilities without additional investment by supplementing the lack of production capacity due to productivity improvement. Third, the Company's difficulties in delivery and capacity shortfalls have been resolved. Fourth, annual sales increased by KRW 109 million and profits increased by KRW 32 million annually. Fifth, it can confirm the usefulness of AHP method in corporate decision making and it can be utilized in various facility investment and process improvement in the future.

• Safety and Health at Work
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• v.10 no.3
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• pp.377-383
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• 2019

Objectives: Exposure to fine particles in urban air has been associated with a number of negative health effects. High levels of fine particles have been detected at underground stations in big cities. We investigated the exposure conditions in four occupational groups in the Stockholm underground train system to identify high-exposed groups and study variations in exposure. Methods: $PM_1$ and $PM_{2.5}$ were measured during three full work shifts on 44 underground workers. Fluctuations in exposure were monitored by a real-time particle monitoring instrument, pDR, DataRAM. Qualitative analysis of particle content was performed using inductively coupled plasma mass spectrometry. Nitrogen dioxide was measured using passive monitors. Results: For all underground workers, the geometric mean (GM) of $PM_1$ was $18{\mu}g/m^3$ and of $PM_{2.5}$ was $37{\mu}g/m^3$. The particle exposure was highest for cleaners/platform workers, and the GM of $PM_1$ was $31.6{\mu}g/m^3$ [geometric standard deviation (GSD), 1.6] and of $PM_{2.5}$ was $76.5{\mu}g/m^3$ (GSD, 1.3); the particle exposure was lowest for ticket sellers, and the GM of $PM_1$ was $4.9{\mu}g/m^3$ (GSD, 2.1) and of $PM_{2.5}$ was $9.3{\mu}g/m^3$ (GSD, 1.5). The $PM_1$ and $PM_{2.5}$ levels were five times higher in the underground system than at the street level, and the particles in the underground had high iron content. The train driver's nitrogen dioxide exposure level was $64.1{\mu}g/m^3$ (GSD, 1.5). Conclusions: Cleaners and other platform workers were statistically significantly more exposed to particles than train drivers or ticket sellers. Particle concentrations ($PM_{2.5}$) in the Stockholm underground system were within the same range as in the New York underground system but were much lower than in several older underground systems around the world.

• Journal of Intelligence and Information Systems
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• v.22 no.1
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• pp.83-105
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• 2016

Measuring an individual's subjective wellbeing in an accurate, unobtrusive, and cost-effective manner is a core success factor of the wellbeing support system, which is a type of medical IT service. However, measurements with a self-report questionnaire and wearable sensors are cost-intensive and obtrusive when the wellbeing support system should be running in real-time, despite being very accurate. Recently, reasoning the state of subjective wellbeing with conventional sentiment analysis and unstructured data has been proposed as an alternative to resolve the drawbacks of the self-report questionnaire and wearable sensors. However, this approach does not consider contextual polarity, which results in lower measurement accuracy. Moreover, there is no sentimental word net or ontology for the subjective wellbeing area. Hence, this paper proposes a method to extract keywords and their contextual polarity representing the subjective wellbeing state from the unstructured text in online websites in order to improve the reasoning accuracy of the sentiment analysis. The proposed method is as follows. First, a set of general sentimental words is proposed. SentiWordNet was adopted; this is the most widely used dictionary and contains about 100,000 words such as nouns, verbs, adjectives, and adverbs with polarities from -1.0 (extremely negative) to 1.0 (extremely positive). Second, corpora on subjective wellbeing (SWB corpora) were obtained by crawling online text. A survey was conducted to prepare a learning dataset that includes an individual's opinion and the level of self-report wellness, such as stress and depression. The participants were asked to respond with their feelings about online news on two topics. Next, three data sources were extracted from the SWB corpora: demographic information, psychographic information, and the structural characteristics of the text (e.g., the number of words used in the text, simple statistics on the special characters used). These were considered to adjust the level of a specific SWB. Finally, a set of reasoning rules was generated for each wellbeing factor to estimate the SWB of an individual based on the text written by the individual. The experimental results suggested that using contextual polarity for each SWB factor (e.g., stress, depression) significantly improved the estimation accuracy compared to conventional sentiment analysis methods incorporating SentiWordNet. Even though literature is available on Korean sentiment analysis, such studies only used only a limited set of sentimental words. Due to the small number of words, many sentences are overlooked and ignored when estimating the level of sentiment. However, the proposed method can identify multiple sentiment-neutral words as sentiment words in the context of a specific SWB factor. The results also suggest that a specific type of senti-word dictionary containing contextual polarity needs to be constructed along with a dictionary based on common sense such as SenticNet. These efforts will enrich and enlarge the application area of sentic computing. The study is helpful to practitioners and managers of wellness services in that a couple of characteristics of unstructured text have been identified for improving SWB. Consistent with the literature, the results showed that the gender and age affect the SWB state when the individual is exposed to an identical queue from the online text. In addition, the length of the textual response and usage pattern of special characters were found to indicate the individual's SWB. These imply that better SWB measurement should involve collecting the textual structure and the individual's demographic conditions. In the future, the proposed method should be improved by automated identification of the contextual polarity in order to enlarge the vocabulary in a cost-effective manner.

• 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.