• The Journal of Korean Orthopaedic Ultrasound Society
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• v.7 no.2
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• pp.105-112
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• 2014

Purpose: Ultrasound-guided epidural caudal block for low back pain and radiating pain is often performed in the treatment of outpatients. However, this procedure has a failure rate of up to 25% even when it performed by an experienced physician. The authors investigate the effectiveness of Ultrasound-guided epidural caudal block in patients related to disc herniation or spinal stenosis. Materials and Methods: Ultrasound-guided caudal epidural block was performed in 55 outpatients with LBP and radiating pain. Patient was placed in the prone position and sonographic image of sacral hiatus was obtained using linear probe. A 22-gauge needle was advanced into the sacrococcygeal membrane under ultrasound guidance and then medication was injected into the caudal epidural space. There were 31 cases of disc herniation, and 24 cases of spinal stenosis. Patients were evaluated by Visual Analog Scale (VAS) pain score at pre-treatment, post-treatment, 2 weeks and 4 weeks by telephone interviews. Results: 53 of the 55 cases (96.4%) of needle insertion into the sacral canal under ultrasound guidance were successful. Gender was not significantly different between disc herniation group and spinal stenosis group. But there was a significant age difference between disc herniation group ($42.3{\pm}10.8$), and spinal stenosis group ($62.8{\pm}15.1$) [p<0.001]. The VAS score at pre-treatment, post-treatment, 2 weeks, 4 weeks in disc group were 6.84, 3.1, 1.8 & 1.77. The VAS score at pre-treatment, post-treatment, 2 weeks, 4 weeks in spinal stenosis group were 6.88, 3.58, 4.33 & 4.88. The VAS score in both groups was significantly improved after the procedure (p<0.001). Over time, the two groups were statistically significant differences in VAS score after adjusting for age (p<0.001). Conclusion: Ultrasound-guided caudal epidural block seems to provide a high success rate and a significantly better response in disc group than spinal stenosis group.

• Korean Journal of Psychosomatic Medicine
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• v.20 no.2
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• pp.75-81
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• 2012

Objectives : Thyroid cancer patients may experience emotional distress during cancer treatment including surgical operation and radioactive iodine treatment. The aims of this prospective study were to investigate changes of anxiety and depressive symptoms in patients with differentiated thyroid cancer(DTC) under preoperative, postoperative and short-term hypothyroidism state. Methods : Using the Hospital Anxiety and Depression scale(HAD) and the Distress Thermometer, we sequentially assessed the levels of anxiety, depression and distress in 41 DTC patients at 3 time points such as preoperative state, postoperative state and short-term hypothyroidism state. Results : The HAD-anxiety score was significantly higher in preoperative state($6.93{\pm}3.97$) than postoperative state($4.22{\pm}2.92$) and short-term hypothyroidism state($4.93{\pm}3.64$). Any other significant change in depression or distress thermometer score was not observed. Especially, difference of HADS score between the distress and none-distress groups was significant in preoperative state and post-operative state, but the difference become not significant in the short-term hypothyroidism state. Conclusions : Induced thyroid hormone deficiency during cancer treatment does not significantly affect emotional distress in patient with DTC. Anxiety and depression in these patients may be associated with distress of the patient before active cancer treatment.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.4
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• pp.311-318
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• 2010

U. S. NRC Regulation Guide 1.52 regulating ESF ACS in nuclear power plants has been revised to revision 3. To apply reduction of operability test time, allowance of alternative challenge agents for in-place leak test of HEPA filters, and upgrade of Methyl Iodide penetration acceptance criterion in activated carbon performance test suggested in Reg. Guide 1.52(Rev.3) on Yonggwang units 5 and 6 ESF ACSes, technical feasibility study was carried out with on-site experiments as well as experiments with a lab-scale model. It was confirmed that the moisture in the system returned to the level before the test in 1 or 4 days even though the moisture was removed during the operability test lasting more than 10 hours. Therefore, it is appropriate to perform monthly operability test in 15 minutes just long enough to check the operability of equipment. To change challenge material for in-place HEPA filter leak test, size of aerosol, production rate, and leak detection capability were compared for DOP and PAO. It was concluded that PAO can be substituted for DOP in nuclear power plants. The upgrade of Methyl Iodide penetration acceptance criterion from 0.175 % to 0.5 % in active carbon filter bed deeper than 4 inches was to conform to the change of activated carbon performance test method to ASTM D3803(1989). It was confirmed that Methyl Iodide penetration acceptance criterion of 0.5 % under $30^{\circ}C$, relative humidity 95 % condition was conservatively good enough for testing performance of active carbon insitu. The licence change of Yonggwang units 5 and 6 has been completed based on this study.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.3
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• pp.389-396
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• 2014

Purpose: The study examined dry eye symptoms of occupants in a newly constructed building and its effects on their work productivity and general activity. Methods: The study subjects were 33 office workers who spent more than eight hours per day on average in a new building constructed in the past three months. The indoor air quality of the new building was evaluated by measuring aldehydes, temperature and humidity. The level of dry eye symptoms was classified into normal, mild, moderate and severe by using the Ocular Surface Disease Index (OSDI). The experience of LASIK surgery, use of eye makeup, daily use time of a computer and smart-phone, and average daily working hours were also examined. The Work Limitation Productivity Questionnaire was used as the questionnaire about work productivity and general activity to measure the impairment level on a ten-point scale. Results: The concentration variation of formaldehyde in the office was $42.42{\pm}6.30{\mu}g/m^3$. The temperature and humidity were $26.2{\pm}0.70^{\circ}C$ and $40{\pm}1%$, respectively. The respondents with normal, mild, moderate and severe dry eye symptoms were 15.2%, 18.2%, 18.2% and 48.5%, respectively. The severity of dry eye symptoms and impairment of work productivity and general activity demonstrated high correlations of 0.599 and 0.655, respectively (p<0.001). Compared to the normal case, severe dry eye symptoms demonstrated significantly high impairment of work productivity and interruption of general activity (p<0.001). The case of serious dry symptoms showed the possibilities of having impairment level of work productivity and interruption of general activity above three points 3.26 times (p=0.032) and 2.25 times (p=0.045), respectively, higher than that of the normal case. Conclusions: It was confirmed that dry eye symptoms among office workers in a newly constructed building affects work productivity and general activity.

• Clinical and Experimental Pediatrics
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• v.46 no.3
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• pp.265-270
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• 2003

Purpose : To characterize the infants under 3 months of age with urinary tract infections(UTIs), and especially patients with bacteremia or meningitis Methods : Hospital records of all the infants under 3 months of age discharged from our hospital for 69 consecutive months with the diagnosis of initial episode of UTI were reviewed. UTI was defined when patients had fever with pyuria, and had urine culture results of ${\geq}10^5$ colony forming units/mL from a bag specimen. Patients with previously known urologic abnormality or immunodeficiency were excluded. Nosocomial infections were also excluded from the study. Results : The male:female ratio was 35 : 6. Of the urine cultures, 40(97.6%) yielded single pathogen, one yielded two pathogens. Escherichia coli was the predominant isolate from the urine. Five patients(12%) also had bacteremia. Pathogens isolated from the blood cultures were E. coli(4) and Enterococcus faecalis(1). No patient had culture-positive meningitis or cerebrospinal fluid pleocytosis. Clinical or laboratory findings between patients with and without bacteremia were not different significantly. The rate of vesicoureteral reflux(VUR) was 44%. The sensitivity of ultrasound for detection of VUR was 38%; specificity was 50%. Conclusion : Clinical and laboratory data were not helpful for identifying patients with bacteremia at the time of presentation. Consequently, blood cultures need to be obtained from all febrile infants under 3 months of age with UTIs. A large-scale study including the indication of lumbar puncture for infants with a febrile UTI and study of evaluation and treatment of infants under 3 months of age with UTIs are required.

• Journal of Korean Orthopaedic Sports Medicine
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• v.4 no.1
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• pp.18-28
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• 2005

Purpose: The purpose of this study is to evaluate the clinical, radiological and histopathological results after microfracture surgery for degenerative arthritis of the knee. Materials and Methods: From Oct. 1997 to Dec. 1998, 48 knees in 46 patients were treated by microfracture technique. Their mean age at the time of operation was 56 years(range, 40-75 years) and mean period of follow-up study was one year(range, 7-20 months). For 24 knees in 22 patients, 'second-look' arthroscopies and biopsies were performed at 6 months following microfracture. At the last follow up clinical results were evaluated with Baumgaertner's scale. The specimens of 24 cases were stained with H-E, Safranin-O, and Masson's trichrome. Eighteen of 24 cases were stained immunohistochemically and the Western blotting test was performed on 12 cases for type II collagen. We analyzed the relationship of the Western blotting for type II collagen with clinical score, preoperative varus deformity, joint space widening in radiological result, extent of repaired articular cartilage in '2nd-look' arthroscopic findings, patient's age and weight. Results: Clinical results were excellent in 90% and good in 10%. Among the 24 knees, more than 80% of areas of chondral defect were covered with regenerated cartilage in 21 knees Histologically, the repaired tissue appears to be a hybrid of hyaline cartilage and fibrocartilage. Repaired cartilage contains variable amounts of type II collagen with immunohistochemical staining. The results of the Western blotting test were similar. The amounts of type II collagen formation had positive correlation with the extent of repaired cartilage and preoperative varus deformity. Conclusion: 'Second-look' showed that the chondral defect areas were covered with newly grown grayish white tissue. Articular cartilage repair was confirmed with histological and immunohisto-chemical study qualitatively, and the amount of type II collagen was calculated with the Western blotting test quantitatively. The exact nature and fate of repaired cartilagenous tissues need further long term follow-up study. The results of this study provide the rationale to select osteoarthritic patients indicated for microfracture surgery.

• Journal of Intelligence and Information Systems
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• v.18 no.4
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• pp.129-143
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• 2012

Recently, the rapid progress of a number of standardized web technologies and the proliferation of web users in the world bring an explosive increase of producing and consuming information documents on the web. In addition, most companies have produced, shared, and managed a huge number of information documents that are needed to perform their businesses. They also have discretionally raked, stored and managed a number of web documents published on the web for their business. Along with this increase of information documents that should be managed in the companies, the need of a solution to locate information documents more accurately among a huge number of information sources have increased. In order to satisfy the need of accurate search, the market size of search engine solution market is becoming increasingly expended. The most important functionality among much functionality provided by search engine is to locate accurate information documents from a huge information sources. The major metric to evaluate the accuracy of search engine is relevance that consists of two measures, precision and recall. Precision is thought of as a measure of exactness, that is, what percentage of information considered as true answer are actually such, whereas recall is a measure of completeness, that is, what percentage of true answer are retrieved as such. These two measures can be used differently according to the applied domain. If we need to exhaustively search information such as patent documents and research papers, it is better to increase the recall. On the other hand, when the amount of information is small scale, it is better to increase precision. Most of existing web search engines typically uses a keyword search method that returns web documents including keywords which correspond to search words entered by a user. This method has a virtue of locating all web documents quickly, even though many search words are inputted. However, this method has a fundamental imitation of not considering search intention of a user, thereby retrieving irrelevant results as well as relevant ones. Thus, it takes additional time and effort to set relevant ones out from all results returned by a search engine. That is, keyword search method can increase recall, while it is difficult to locate web documents which a user actually want to find because it does not provide a means of understanding the intention of a user and reflecting it to a progress of searching information. Thus, this research suggests a new method of combining ontology-based search solution with core search functionalities provided by existing search engine solutions. The method enables a search engine to provide optimal search results by inferenceing the search intention of a user. To that end, we build an ontology which contains concepts and relationships among them in a specific domain. The ontology is used to inference synonyms of a set of search keywords inputted by a user, thereby making the search intention of the user reflected into the progress of searching information more actively compared to existing search engines. Based on the proposed method we implement a prototype search system and test the system in the patent domain where we experiment on searching relevant documents associated with a patent. The experiment shows that our system increases the both recall and precision in accuracy and augments the search productivity by using improved user interface that enables a user to interact with our search system effectively. In the future research, we will study a means of validating the better performance of our prototype system by comparing other search engine solution and will extend the applied domain into other domains for searching information such as portal.

• Journal of Intelligence and Information Systems
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• v.26 no.1
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• pp.23-45
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• 2020

Big data is creating in a wide variety of fields such as medical care, manufacturing, logistics, sales site, SNS, and the dataset characteristics are also diverse. In order to secure the competitiveness of companies, it is necessary to improve decision-making capacity using a classification algorithm. However, most of them do not have sufficient knowledge on what kind of classification algorithm is appropriate for a specific problem area. In other words, determining which classification algorithm is appropriate depending on the characteristics of the dataset was has been a task that required expertise and effort. This is because the relationship between the characteristics of datasets (called meta-features) and the performance of classification algorithms has not been fully understood. Moreover, there has been little research on meta-features reflecting the characteristics of multi-class. Therefore, the purpose of this study is to empirically analyze whether meta-features of multi-class datasets have a significant effect on the performance of classification algorithms. In this study, meta-features of multi-class datasets were identified into two factors, (the data structure and the data complexity,) and seven representative meta-features were selected. Among those, we included the Herfindahl-Hirschman Index (HHI), originally a market concentration measurement index, in the meta-features to replace IR(Imbalanced Ratio). Also, we developed a new index called Reverse ReLU Silhouette Score into the meta-feature set. Among the UCI Machine Learning Repository data, six representative datasets (Balance Scale, PageBlocks, Car Evaluation, User Knowledge-Modeling, Wine Quality(red), Contraceptive Method Choice) were selected. The class of each dataset was classified by using the classification algorithms (KNN, Logistic Regression, Nave Bayes, Random Forest, and SVM) selected in the study. For each dataset, we applied 10-fold cross validation method. 10% to 100% oversampling method is applied for each fold and meta-features of the dataset is measured. The meta-features selected are HHI, Number of Classes, Number of Features, Entropy, Reverse ReLU Silhouette Score, Nonlinearity of Linear Classifier, Hub Score. F1-score was selected as the dependent variable. As a result, the results of this study showed that the six meta-features including Reverse ReLU Silhouette Score and HHI proposed in this study have a significant effect on the classification performance. (1) The meta-features HHI proposed in this study was significant in the classification performance. (2) The number of variables has a significant effect on the classification performance, unlike the number of classes, but it has a positive effect. (3) The number of classes has a negative effect on the performance of classification. (4) Entropy has a significant effect on the performance of classification. (5) The Reverse ReLU Silhouette Score also significantly affects the classification performance at a significant level of 0.01. (6) The nonlinearity of linear classifiers has a significant negative effect on classification performance. In addition, the results of the analysis by the classification algorithms were also consistent. In the regression analysis by classification algorithm, Naïve Bayes algorithm does not have a significant effect on the number of variables unlike other classification algorithms. This study has two theoretical contributions: (1) two new meta-features (HHI, Reverse ReLU Silhouette score) was proved to be significant. (2) The effects of data characteristics on the performance of classification were investigated using meta-features. The practical contribution points (1) can be utilized in the development of classification algorithm recommendation system according to the characteristics of datasets. (2) Many data scientists are often testing by adjusting the parameters of the algorithm to find the optimal algorithm for the situation because the characteristics of the data are different. In this process, excessive waste of resources occurs due to hardware, cost, time, and manpower. This study is expected to be useful for machine learning, data mining researchers, practitioners, and machine learning-based system developers. The composition of this study consists of introduction, related research, research model, experiment, conclusion and discussion.

• Journal of Soil and Groundwater Environment
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• v.13 no.4
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• pp.30-39
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• 2008

The uranium removal efficiency of rhizofiltration was investigated in lab scale experiment. Three plants such as sunflower (Helianthus annuus L.), bean (Phaseolus vulgaris var.), and Indian mustard (Brassica juncea (L.) Czern.) were cultivated in artificially contaminated solution by uranium at 30 ${\mu}g$/L and 80 ${\mu}g$/L for 72 hours. The removal efficiencies of three cultivars were calculated from the ICP/MS analysis of uranium mass in solution and the plant. For Helianthus annuus L., more than 80% of initial uranium were removed from the solution and the uranium concentration of residual solution maintained lower than 10 ${\mu}g$/L. For Phaseolus vulgaris var. and Brassica juncea (L.) Czern., their uranium removal efficiencies ranged from 60 to 80%. Even the uranium concentration of solution was higher than 500 ${\mu}g$/L, these cultivars removed more than 70% of initial uranium by rhizofiltration, suggesting that the rhizofiltration has a great capability to remove uranium in the contaminated groundwater. The removal efficiency of rhizofiltration by using Brassica juncea (L.) Czern decreased from 83% to 42% with the increase of pH in solution. From the results of the analysis for the uranium accumulation in plants, 99% of uranium transferred into the plant from solution were accumulated in the root and only 1% of uranium existed in the shoot part (including leaves), suggesting that the cost and the time to treat massive grown plants after the rhizofiltration could be dramatically cut down because only their root parts needs to be treated. Finally, the genuine groundwater having high uranium concentration (81.4 ${\mu}g$/L), sampled from Daejoun area, was used in the experiment. The uranium removal efficiency of Helianthus annuus L. for the real groundwater was higher than 95%, investigating that the rhizofiltration is the very useful method to remediate uranium contaminated groundwater.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.4
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• pp.283-295
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• 1979

A new Farmland Expansion and Development Promotion Law was enacted in 1975. This law authorizes the Government to undertake development within a declared "reclamation area", wherever the land owners are unable to do so. In order to give additional impetus to conversion of waste hilly land into productive farmland, these hilly land development projects were conducted as large scale scheme which include soil fertility improvements such as the application of lime and phosphate. Farmland Expansion and Development Promotion Corps has attempted to undertake annual farm surveys in order to obtain some information about hilly land agriculture and farming operations within the reclamation project areas since 1976. As survey data accumulates, more and more clear picture of hilly land farming come to appear and enable us to conduct in-depth study. Effects of such upland reclamation include converting of previously unproductive slopeland into cultivable farmland for lucrative and commercial farming or food production. Furthermore, idle or marginal resources such as farm labor, equipment and compost would be fully employed. Socio-economic effects would include increases in land value and attitude change of farmers. On the other hand the preservation of natural environments might be damaged to the some extend by the projects. As shown in Table 7, the average farm size increased from 3,156 pyeong($3.3m^2$) to 5,562 pyeong, a 76.2% increase. The proportion of small farms with less than I ha dropped from 59.8% to 34.4%, but that of the large farms over 2 ha rose from 13.1% to 32.0% (See Table 8). The survey results indicate that as the farming on reclaimed uplands become time-honored, the acreage devoted for food crop production decreases against the economic crop growing acreage (see Table 6). For example, in the case of uplands reclaimed in 1972, the ratio of food crop acreages decreased from 99.7% in 1972 to 62.5% in 1977, whereas that of economic crop acreages increased from 0.3% in 1972 to 37.5% in 1977. The government used to actively encourage the farmers to carry out food crop production in the reclaimed upland targting toward the realization of self-sufficiency in food grains. It is, however, apparent that the farmers did hardly take the government advises as far as their economic interest were concerned. Yield per 10a. of various crops from the reclaimed uplands by year were surveyed as seen in Table 12. On the average, barley production in the reclaimed areas achieved 83.3% of the average unit yield from the existing upland in its 5 th year. Soybean yields showed a modest increase from 64% in the first year to 95%, in the 5 th year. In contrast, economic crops such as red pepper, totacco and radish achieved their maximum target yields in 3 years from starting to cultivate on the reclaimed farms. In order to test the post economic viability, an economic analysis was performed for each of selected subprojects on the basis of the data obtained through survey. The average actual internal economic rate of return on upland reclamation investments was found to be 20.3% which exceeded other types of projects of land and water development such as tidal land reclamation, irrigation or paddy rearrangement. The actual IRRs of subcategories of upland reclamation projects varied from 17.9% to 21.4% depending upon the kinds of cropping system adopted in each reclaimed areas such as food, economic, fruit or forage crops.