• Journal of the Korea Concrete Institute
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• v.24 no.3
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• pp.275-283
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• 2012

Steel Plate for Rebar Connection was recently developed to splice rebars in delayed slab-wall joints in high-rise building, slurry wall-slab joints, temporary openings, etc. It consists of several couplers and a thin steel plate with shear key. Cyclic loading tests on slab-wall joints were conducted to verify structural behavior of the joints having Steel Plate for Rebar Connection. For comparison, joints with Rebend Connection and without splices were also tested. The joints with Steel Plate for Rebar Connection showed typical flexural behavior in the sequence of tension re-bar yielding, sufficient flexural deformation, crushing of compression concrete, and compression rebar buckling. However, the joints with Rebend Connection had more bond cracks in slabs faces and spalling in side cover-concrete, even though elastic behavior of the joints was similar to that of the joints with Steel Plate for Re-bar Connection. Consequently, the joints with Rebend Connection had less strengths and deformation capacities than the joints with Steel Plate for Re-bar Connection. In addition, stiffness of the joints with Rebend Connection degraded more rapidly than the other joints as cyclic loads were applied. This may be caused by low elastic modulus of re-straightened rebars and restraightening of kinked bar. For two types of diameters (13mm and 16mm) and two types of grades (SD300 and SD400) of rebars, the joints with Steel Plate for Rebar Connection had higher strength than nominal strength calculated from actual material properties. On the contrary, strengths of the joints with Rebend Connection decreased as bar diameter increased and as grade becames higher. Therefore, Rebend Connection should be used with caution in design and construction.

• Journal of Oral Medicine and Pain
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• v.34 no.4
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• pp.397-407
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• 2009

The aim of the study was to evaluate psychosocial impact of non-dental chronic orofacial pain (OFP) on daily living using the graded chronic pain (GCP) scale. It is also investigated the clinical profile such as demographics, event related to initiation of OFP and prior treatments for patients. During previous 6 months since September 2008, 572 patients (M:F=1:1.5, mean age=34.7 years) with non-dental OFP attended university-based specialist orofacial pain clinic (Dankook University Dental Hospital, Cheonan) to seek care although 63% of them already experienced related treatment for their OFP problem. They visited the most frequently general dental practitioner and orthopedic doctors due to their pain problem and medication was the most commonly employed modality. Most of the patients (89.2%) had TMD and the most common related event to initiation of their pain was trauma, followed by dental treatment. Almost half of the patients (46%) suffered from chronic pain(${\geq}6\;M$) and 40% of them exhibited relatively high disability due to chronic OFP. GCP pain intensity and disability days were significantly different for age and diagnosis (p<0.05) but not for gender and duration. GCP grades were affected by all the factors including gender, age, pain duration and diagnosis.(p=0.000) Female gender, elders, and long lasting pain were closely related to high disability. The patients with neuropathic Pain and mixed OFP rather than TMD were graded as being highly disabled. Conclusively, a considerable percentage of chronic OFP patients reports high pain-related disability in their daily, social and work activity, which suggest a need for psychosocial support and importance of earlier referral for appropriate diagnosis and tailored management.

• Journal of Korean Society of Forest Science
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• v.102 no.2
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• pp.272-280
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• 2013

This study aims to develop a standard diagnostic table for management and administration that oak mushroom cultivators of forestry households can utilize. By diagnosing their current level of management with the table, the cultivators themselves will be able to grasp and address their operational challenges better. The table is composed of; questions on the status of forestry households; columns for a series of management performance indices, and; questionnaire with 4 categories and 20 subcategories to check the current level of management and administration by the households. In order to prepare the standard diagnostic table for oak mushroom management, 196 forestry households throughout 10 areas - Cheong-yang, Gong-ju, Bu-yeo and Seocheon in Chungcheongnam-do, Mun-kyung and Ye-cheon in Gyeongsangbuk-do, Jin-an in Jeollabuk-do, Jangheung and Jang-seong in Jeollanam-do, and Jeju Islands - were interviewed with and a total of 190 questionnaires were acquired and made use of in the result analysis. Then, the score on management level of each forestry household was determined in the way of aggregating scores from each subcategory. The overall average score of every household was calculated at 62.2 point with more than half of the respondents, 54.7%, belonging to the range of 60 to 80. When considered by regional groups, the average score of Jin-an was the lowest with 57.6 point while that of Jang-seong was the highest with 69.6 point. In case of the 'cultivation management' category, there were a lot of cultivators who expressed a negative awareness of the term 'pest control' because they had a tendency to think the term in connection with 'herbicides or pesticides'. So it is inevitable to adapt and modify existing groups and grades to make sure that the cultivators can make a right choice without confusing the concept 'pest control' with 'herbicides or pesticides'. Meanwhile, the average scores of 'management and administration' categories were mostly low. It was remarkable in these categories that forestry households in Jeolla province, which had remained in lower ranks in the other three categories, recorded higher scores than those in Chungcheong province, boasting a relatively high level of management and administration.

• Journal of The Korean Association For Science Education
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• v.18 no.4
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• pp.601-615
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• 1998

Establishing and evaluating science education policies and revising and monitoring the effectiveness of science curriculum should be based upon the results of systematic and scientific research studies. Advanced nations have already been administering and developing national level science assessments for these purposes. The science assessments administered in Korea have been reported having many limitations and problems, and not succeeded in providing data for science education policy making and curriculum reform. The major purpose of the study is developing national level science knowledge assessment system in order to identify longitudinal trends of elementary and secondary school students science knowledge achievements. The research team consisted of science education experts and teachers from various school levels, decided the directions and major elements of national level science knowledge assessment with the consultation of educational evaluation experts. Item developing ability of the researchers was improved by seminars? and workshops on national assessment in advanced nations and developing skills of writing science items. Nearly 500 items were developed and revised. Pilot test was administered with 958 students at various school levels. 380 items were selected and tested with 8766 students, and the characteristics were analyzed in terms of item response theory. The target populations for national level science knowledge assessment are 5th-grade of elementary school, 2nd-grade of middle school, 1st and 2nd-grade of high school students. The proper period for the assessment is February every year. Multi-stage clustered sampling method is desirable and rotated forms are recommendable for the test format. Bridge items should be introduced to compare the results of multiple tests, and various grades. Anchor items should also be used for longitudinal interpretations of the results. The items for elementary school require low to medium abilities, for middle school and first grade of high school require medium to high abilities and for 2nd-grade of high school high abilities. The discrimination ability of the items developed is high.

• Journal of Korean Society of Forest Science
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• v.32 no.1
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• pp.1-8
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• 1976

One of the most common needle leaf species used in planting in Korea is korean pine (Pinus koraiensis S. et Z.), and jack pine (Pinus banksiana Lamb.) is one of the test species for suitability. The relation of nursery bed density of 2-1 korean pine and 1-1 jack pine was studied at the Kwang Nung Nursery, Central Branch Station of Forest Research Institute, and about 40km north of Seoul. Nursery bed density of 2-1 korean pine, which ranged from 36 to 324 trees per square meters and of 1-1 jack pine, which ranged from 25 to 169 trees per square meters, had a marked effect on caliper, height, dry weight and percent and amount of plantable stock. The soil physical and chemical properties is silt plus clay, 50.55 percent; organic matter, 2.09 percent; total nitrogen, 0.13 percent; available phosphorus, 253.25 ppm; exchangeable potash, 0.46 m.e/100g; and pH, 5.58. As the density of the nursery seedling stand of 2-1 korean pine increases, the average tree height increases (Fig. 1A), but in 1-1 jack pine density do not affect to increase or decrease the average tree height. As the density of nursery bed increases, the average stem caliper (at 2cm above ground line) and dry weight decrease (Fig. 1B), but the decreasing rate is more seriously in 1-1 jack pine than 2-1 korean pine (Fig.5). As increasing the density of nursery bed, the T/R ratio of trees of the test species increase. Also the dry weight of leaf, stem and root parts are decreasing in proportion to the increase of stand density, but the drop rate of jack pine is more rapid than korean pine (table. 1) The patent facts of difference of growth characteristics between 2-1 korean pine and 1-1 jack pine were studied. These facts should be used to select the scale of stand density at the nursery bed or the plantable site. Korean pine is demanded high density, on the other hand in jack pine low density are more suitable to manage the stand density. Stands of comparatively low density had the greatest percentage of high-quality stock, and the stands of high density had less than the high quality trees of low density. An important criterion of the best density is percent and number of high-quality trees produced per square meter of bed area. Stem caliper and stem height of seedling is used in most public nurseries to sort seedling into plantable grades. The stock grade standard has set at 4.5mm caliper and 16cm height of 2-1 korean pine as the minimum desired stem caliper and height. By the result studies, the plantable stock grade standards of 2-1 korean pine used at stem height 16cm and stem caliper 4.5mm from public nurseries should be reformed to stem height 18cm and stem caliper 4.0mm by the growth characteristics and the tree distribution of stem height and caliper of relation to density. For the 2-1 korean pine, best density should be about 160 to 200 trees per square meter according to soil fertility. For the 1-1 jack pine, the suitable standard of plantable stock should be at stem height 25cm and caliper 6mm (at 2cm above ground line) and best density was about 100 to 120 trees.

• Journal of Intelligence and Information Systems
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• v.16 no.4
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• pp.67-84
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• 2010

In terms of business, forecasting is a work of what is expected to happen in the future to make managerial decisions and plans. Therefore, the accurate forecasting is very important for major managerial decision making and is the basis for making various strategies of business. But it is very difficult to make an unbiased and consistent estimate because of uncertainty and complexity in the future business environment. That is why we should use scientific forecasting model to support business decision making, and make an effort to minimize the model's forecasting error which is difference between observation and estimator. Nevertheless, minimizing the error is not an easy task. Case-based reasoning is a problem solving method that utilizes the past similar case to solve the current problem. To build the successful case-based reasoning models, retrieving the case not only the most similar case but also the most relevant case is very important. To retrieve the similar and relevant case from past cases, the measurement of similarities between cases is an important key factor. Especially, if the cases contain symbolic data, it is more difficult to measure the distances. The purpose of this study is to improve the forecasting accuracy of case-based reasoning approach using fuzzy relation and composition. Especially, two methods are adopted to measure the similarity between cases containing symbolic data. One is to deduct the similarity matrix following binary logic(the judgment of sameness between two symbolic data), the other is to deduct the similarity matrix following fuzzy relation and composition. This study is conducted in the following order; data gathering and preprocessing, model building and analysis, validation analysis, conclusion. First, in the progress of data gathering and preprocessing we collect data set including categorical dependent variables. Also, the data set gathered is cross-section data and independent variables of the data set include several qualitative variables expressed symbolic data. The research data consists of many financial ratios and the corresponding bond ratings of Korean companies. The ratings we employ in this study cover all bonds rated by one of the bond rating agencies in Korea. Our total sample includes 1,816 companies whose commercial papers have been rated in the period 1997~2000. Credit grades are defined as outputs and classified into 5 rating categories(A1, A2, A3, B, C) according to credit levels. Second, in the progress of model building and analysis we deduct the similarity matrix following binary logic and fuzzy composition to measure the similarity between cases containing symbolic data. In this process, the used types of fuzzy composition are max-min, max-product, max-average. And then, the analysis is carried out by case-based reasoning approach with the deducted similarity matrix. Third, in the progress of validation analysis we verify the validation of model through McNemar test based on hit ratio. Finally, we draw a conclusion from the study. As a result, the similarity measuring method using fuzzy relation and composition shows good forecasting performance compared to the similarity measuring method using binary logic for similarity measurement between two symbolic data. But the results of the analysis are not statistically significant in forecasting performance among the types of fuzzy composition. The contributions of this study are as follows. We propose another methodology that fuzzy relation and fuzzy composition could be applied for the similarity measurement between two symbolic data. That is the most important factor to build case-based reasoning model.

• Journal of Intelligence and Information Systems
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• v.19 no.4
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• pp.97-121
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• 2013

With the growing importance of knowledge for sustainable competitive advantages and innovation in a volatile environment, many researches on knowledge sharing have been conducted. However, previous researches have mostly relied on the questionnaire survey which has inherent perceptive errors of respondents. The current research has drawn the relationship among primary participant behaviors towards the participation level in knowledge sharing, basically from online user behaviors on Wikipedia, a representative community for online knowledge collaboration. Without users' participation in knowledge sharing, knowledge collaboration for creating knowledge cannot be successful. By the way, the editing patterns of Wikipedia users are diverse, resulting in different revisiting periods for the same number of edits, and thus varying results of shared knowledge. Therefore, we illuminated the participation level of knowledge sharing from two different angles of number of edits and revisiting period. The behavioral dimensions affecting the level of participation in knowledge sharing includes the article talk for public discussion and user talk for private messaging, and community registration, which are observable on Wiki platform. Public discussion is being progressed on article talk pages arranged for exchanging ideas about each article topic. An article talk page is often divided into several sections which mainly address specific type of issues raised during the article development procedure. From the diverse opinions about the relatively trivial things such as what text, link, or images should be added or removed and how they should be restructured to the profound professional insights are shared, negotiated, and improved over the course of discussion. Wikipedia also provides personal user talk pages as a private messaging tool. On these pages, diverse personal messages such as casual greetings, stories about activities on Wikipedia, and ordinary affairs of life are exchanged. If anyone wants to communicate with another person, he or she visits the person's user talk page and leaves a message. Wikipedia articles are assessed according to seven quality grades, of which the featured article level is the highest. The dataset includes participants' behavioral data related with 2,978 articles, which have reached the featured article level, with editing histories of articles, their article talk histories, and user talk histories extracted from user talk pages for each article. The time period for analysis is from the initiation of articles until their promotion to the featured article level. The number of edits represents the total number of participation in the editing of an article, and the revisiting period is the time difference between the first and last edits. At first, the participation levels of each user category classified according to behavioral dimensions have been analyzed and compared. And then, robust regressions have been conducted on the relationships among independent variables reflecting the degree of behavioral characteristics and the dependent variable representing the participation level. Especially, through adopting a motivational theory adequate for online environment in setting up research hypotheses, this work suggests a theoretical framework for the participation level of online knowledge sharing. Consequently, this work reached the following practical behavioral results besides some theoretical implications. First, both public discussion and private messaging positively affect the participation level in knowledge sharing. Second, public discussion exerts greater influence than private messaging on the participation level. Third, a synergy effect of public discussion and private messaging on the number of edits was found, whereas a pretty weak negative interaction effect of them on the revisiting period was observed. Fourth, community registration has a significant impact on the revisiting period, whereas being insignificant on the number of edits. Fifth, when it comes to the relation generated from private messaging, the frequency or depth of relation is shown to be more critical than the scope of relation for the participation level.

• Journal of Yeungnam Medical Science
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• v.2 no.1
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• pp.135-147
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• 1985

The authors studied neuroticism, using Eysenck's Maudsley Personality Inventory (MPI), in 3,893 male college students and 1,976 female college students of Yeungnam University. There was significant difference in the mean averages of total neuroticism scores between male and female students, male students scored $13.45{\pm}7.44$, female students scored $16.89{\pm}7.19$. The items relating to (16) Do you sometimes feel happy, sometimes depressed, without any apparent reason? (38) Do you daydream a lot? (1) Do you have dizzy turns? (2) Do you get palpitations or thumping in your heart? and (35) Do you worry about your health? were scored highly in male, and the items relating to (16) Do you sometimes feel happy, sometimes depressed, without any apparent reason? (1) Do you have dizzy turns? (38) Do you daydream a lot? (8) Do you worry too long over humiliating experiences? (9) Do you consider yourself rather a nervous person? were scored highly in female. Three hundreds and ninety eight male students (10.3%) showed seriously high neuroticism scores of 24 or higher, while 256 female students (13.0%) showed high neuroticism scores of 26 or higher. In a comparison between male students in different school grades, freshman showed the highest level of neuroticism scores. Among the psychosocial factors, there were strong tendencies toward higher neuroticism scores in the students who were dissatisfied with their colleges or departments, and who had pessimistic views of self-image in the past, present, or future in both groups. The male students whose educational fees were paid by their parents, and whose spending money per month was under 10,000 won, showed higher neuroticism scores. The female students whose educational fees were paid by their brothers or sisters, and whose maturation locations were U-P, and who resided in dormitory or other residencies, showed higher neuroticism scores.

• Investigative Magnetic Resonance Imaging
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• v.2 no.1
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• pp.104-112
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• 1998

Purpose : To evaluate the clinical utility of diffusion-weighted imaging by analyzing the signal intersity of lesions in patients with various intracranial diseases. Materials and Methods : difusion-weighted MR imaging was prospectively perormed in randomly selected 70 patients with various intracranial idseases. They consisted of 20 patients with acute infarct, 21 patients with chronic infarct of small vessel disease, 14 patients with primary intracranial tumor, three patients with brain metastasis, five patient with brain abscess, five patients with brain abscess, five patients with cerebral hemorrhage, one patient with neurocysticercosis, and one patient with epidermoid cyst. the diffusion-weighted images were obtained immediately after routine T2-weighted imaging on a 1.5T MR unit using single shot spin echo EPI technique with 6500 ms TR, 107ms TE, $128{\times}128$ matrix, 1 number of excitation, $24{\times}24$ field of view, 5-7 mm slice thickness, 2-3 mm inter-slice gap. The diffusion-gradients (b value of ($1000s{\;}/{\;}textrm{mm}^2$)) were applied along three directions(x, y, z). On visual inspection of diffusion-weighted images, the signal intersity of lesions was arbitrarily graded as one of 5 grades. In quantitative assessment, we measured the signal intensity of all the lesions and the contralateral corresponding normal area using round region of interest(ROI), and then calculated the signal intensity ratio of the lesion to the normal brain parenchyma. Results : On visual inspection, markedly hyperintense signals were seen in all cases of acute infarct, brain abscess, epidermoid cyst, and neurocysticercosis in degenerating stage. In all cases of cerebral hematoma, the very high signal internsity was intermingled with low signal intensity. focal very high signal intersity was also seen in a solid portion of the tumor in a patient. the mean signal intensity ratios of all those lesions to the normal brain parenchyma were above 2.5. Gliosis, solid component of brain tumor, brain metastasis, and vasogenic dedma appeared isointense to the normal brain parenchyma in 71%, 64%, 100%, and 67%, respectively ; the mean signal intensity ratios of those lesions to the normal brain parenchyma ranged 1.15 to 1.28 and there was no significant difference among these(p>0.1). Cystic cerebromalacia and necrotic or cystic portions in tumor were markedly or slightly hypointense, and the mean signal intensity ratios were 0.45 and 0.42, respectively. Conclusion : Very high signal intensity of acute infarct, brain abscess, epidermoid cyst, and cystic neurocysticercosis in degenerating stage on diffusion-weighted images may be helpful in differentiating from other diseases that are hypointense or isointense to the normal brain parenchyma. It may be especially useful differentiation of brain abscess from brain tumor with necrotic or cystic portion.

• Journal of dental hygiene science
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• v.14 no.3
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• pp.332-341
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• 2014

This study was aimed to define the predicting factor account for the Korean Dental Hygienist Licensing Examination (KDHLE) by analyzing the academic grade score and the KDHLE score. The subjects included 185 graduates (2007, 2009, 2011~2014 graduates). The ratio of successful applicants of the subjects was 99.2%. The academic grade scores were calculated to grade point average, the KDHLE was scoring marks out of 300 (200 of written examination score and 100 of performance evaluation score) for correlation and regression analysis. The graduation grades and comprehensive examination scores correlated significantly with the KDHLE written examination scores (correlation coefficient=0.612), and KDHLE total score (correlation coefficient=0.258). First~third grade score and comprehensive examination scores correlated significantly with KDHLE total scores (p<0.05). Especially, there are the highest correlated between second comprehensive examination scores and KDHLE total scores (correlation coefficient=0.455), the last score in time sequence is the important factors account for the KDHLE total score. But there is no correlation between academic grade score and KDHLE performance evaluation scores, therefore it is necessary to study for determine the reason. The results of multiple linear regression analysis, second grade score and the average score of comprehensive examination were the main predicting factors account for the KDHLE total score, the explanatory power was 31.6%. Our results show that KDHLE total and written examination scores are predicted by the academic grade score reliably, but not the KDHLE performance evaluation scores. Further studies are needed to determine relationship between dental hygiene education and KDHLE.