• Journal of radiological science and technology
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• v.15 no.2
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• pp.25-30
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• 1992

With transmitted dose through chest which has the problem of wide variations in absorption, simple film/screen combination method makes it diffucult to image lung field, mediastinum and retrocardiac areas. In order to overcome this, it is very common to use the high kilovoltage technique in diminishing the differences between high and low contrast. We have been adopting this method at department of diagnostic radiology, Seoul National University Hospital. To compare the image of it with that of low kilovoltage technique, we did radiographic tests using beans on the skin. We marked off into three anatomical categories such as lungs, mediastinum and near diaphragm, then attached a bean on a marked area at random. In order to compare with high and low, we took a radiography of high($120{\sim}140\;kVp$) and low($70{\sim}90\;kVp$) kilovoltage tehchniques, respectively at the same time. We have done experiments 320 cases. We evaluated the results of test in response to sensitivity(true positive) and specificity(true negative). In evaluating, we gave them points from 1 to 5 according to true or false. With given points by a radiologist having much experiences, we could acquire the percentage of sensitivity and specificity. The percentage made us to get the schematic table of ROC curve of those two methods. Consequently, high kilovoltage technique appeared 18% better than low kilovoltage technique for detecting beans with our apparatus.

• Progress in Medical Physics
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• v.21 no.1
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• pp.42-51
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• 2010

Imaging studies using MRI, PET, and/or MEG have been primary evaluation methods to quantitatively assess cognitive function. Recent advances in computational technology and information technology may allow a novel evaluation methodology to quantitate cognitive function more cost-effectively. In this study, we developed a software package composed of a series of tests to evaluate cognitive ability combined with a user-friendly touch screen input device. This cognitive assessment tool can quantitate concentration, numeric memory, associative memory, topological memory, visual and muscular reaction, and acoustic reaction over a relatively short testing time. We performed an empirical study on eighty normal subjects aged 20 and 59 years old using the developed evaluation methods. Age-related cognitive deterioration after 40 years old was confirmed. There was no difference in cognitive ability between male and female in the same age group. This study demonstrates the feasibility of a simple but effective evaluation software tool to quantitatively assess cognitive ability. This methodology may provide improved accessibility and reduced costs to perform cognitive function studies to compare between various subject groups.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.3
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• pp.82-87
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• 2013

In this work, the 1L grade integrated metal DOC/DPF filter that can install in engine manifold position was developed to investigate the effect of platinum-coating amount of filter on the improvement of filter activation temperature and reduction of particulate matter (PM). This filter was installed in 2.9L CI engine which meets the EURO-4 emission regulation. Tests for PM reduction efficiency of filter were conducted under ND-13 mode with full-load test condition. It was revealed that the time to reach the activation temperature of metal filter ($280^{\circ}C$) was shorter as the amount of platinum-coating increased. This short activation time can be helpful for the reduction of CO and HC emissions during cold start condition. At the same time, PM reduced as the coating amount increased. The reduction percentage of $DOC_{40}$, $DOC_{20}$, and $DOC_0$ were 96.7% (2.34 mg/kW'h), 95.1% (3.47 mg/kW'h), and 94.5% (3.69 mg/kW'h) compared to previous result (71.4 mg/kW'h), respectively.

• The Korean Journal of Pain
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• v.30 no.1
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• pp.51-58
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• 2017

Background: Recently symptoms-based screening questionnaires have gained attention for screening for a neuropathic pain component (NePC) in various chronic pain conditions. The present study assessed the usefulness of four commonly used NePC screening questionnaires including the Self-completed douleur neuropathique 4 (S-DN4), the ID Pain, the painDETECT questionnaire (PDQ), and the Self-completed Leeds Assessment of neuropathic Symptoms and Signs (S-LANSS) questionnaire in patients with chronic low back pain (CLBP) to assess the presence of NePC. Methods: This is a single-center cross-sectional study where patients with CLBP, with or without leg pain, were included. Participants were initially screened for NePC presence by a physician according to the regular practice, and later assessed using screening questionnaires. The diagnostic accuracy of these questionnaires was compared assuming the physician-made diagnosis as the gold standard. Results: A total of 215 patients with CLBP of which 164 (76.3%, 95% CI, 70.2-81.5) had a NePC were included. S-DN4, ID Pain, and PDQ have an area under the curve (AUC) > 0.8 indicating excellent discrimination. However, S-LANSS has an AUC of 0.69 (0.62-0.75), indicating low discrimination. S-DN4 has a significantly higher AUC as compared to ID Pain (d(AUC) = 0.063, P < 0.01) and S-LANSS (d(AUC) = 0.197, P < 0.01). But the AUC of S-DN4 does not significantly differ from that of PDQ (d(AUC) = 0.013, P = 0.62). Conclusions: S-DN4, ID Pain, and PDQ, but not S-LANSS, have good discriminant validity to screen for NePCs in patients with CLBP. Despite using all the tests, 20-30% of patients with an NePC were missed. Thus, these questionnaires can only be used as an initial clue in screening for NePCs, but do not replace clinical judgment.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.4
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• pp.281-287
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• 2007

Purpose: This study was conducted in order to evaluate how chemiluminescent lighting($ViziLite^{(R)}$) could increase the sharpness of margin and contrast to normal mucosa in the diagnosis of oral lichen planus(OLP), the most frequent oral premalignant lesion, compared with direct visual inspection under incandescent light. Methods: 41 consecutive patients, diagnosed to have OLP with visual inspection under incandescent light, were further examined with chemiluminescent light. The degrees of margin sharpness and lesion contrast were ranked on a scale from 1 to 3 for all patients under visual inspection and chemiluminescent light. The presence of additional lesion only detected by chemiluminescent light, complication, and discomfort were checked for each patient. After both screening tests, biopsy specimens were harvested from all patients with scalpels and histopathologic assessments were done. Results: All 41 patients were diagnosed to have OLP by both visual inspection and chemiluminescent light examination. This result was definitively diagnosed by histopathology. Degrees of margin sharpness and lesion contrast were increased by chemiluminescent light compared with visual inspection, but only the difference of lesion contrast was statistically significant. In 22.0% of patients, additional lesions were detected and 88.9% of them were diagnosed to have OLP histopathologically. 17.1% of patients noted discomfort and 9.8% of patients showed complications after chemiluminescent test. Conclusion: Chemiluminescent light may not be proper for the screen test of oral cancer or premalignant lesion but showed some possibility for additional diagnostic tool for definitively diagnosed patients in determination of lesion margin and scope.

• Information Systems Review
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• v.7 no.1
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• pp.81-96
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• 2005

Because the web sites are in common today, the access to the web for disabled people and old aging people, what we call accessibility, becomes more important. Even though efforts to reduce the informational gap resulted from the lack of the accessibility have been carried out, the studies in this field in Korea are not still in popular. In this study, previous research on the measurements for the accessibility is reviewed and then a new model measuring accessibility is suggested. To increase the validity of the measurement, both an automated tool and a manual test are employed. First we used the 'A-Prompt', one of the popular automated validation tools and analyzed web sources, and applied manual tests by HPR Screen Reader. With the error rates calculated, the accessibility of the government web sites between Korea and the United States was compared and finally the conclusions were drawn.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1171-1176
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• 2012

Objective: The current study aimedto screen for possible factors which affect prognosis of chondrosarcoma. Methods: Thirty seven cases were selected and analyzed statistically. The patients received surgical treatment at our hospital between December 2005 and March 2008. All of them had complete follow-up data. The survival rates were calculated by univariate analysis using the Kaplan-Meier method and tested by Log-rank. ${\chi}^2$ or Fisher exact tests were carried out for the numeration data. The significant indexes after univariate analysis were then analyzed by multivariate analysis using COX regression model. Based on the literature, factors of gender, age, disease course, tumor location, Enneking grades, surgical approaches, distant metastasis and local recurrence were examined. Results: Univariate analysis showed that there were significant differences in Enneking grades, surgical approaches and distant metastasis related to the patients' 3-year survival rate after surgery (P<0.001). No significant difference was not found in gender, age, disease course, tumor location or local recurrence (P>0.05). Multivariate analysis showed that Enneking grade (P=0.007) and surgical approaches (P=0.010) were independent factors affecting the prognosis of chondrosarcoma, but distant metastasis was not (P=0.942). Conclusion: Enneking grades, surgical approaches and distant metastasis are risk factors for prognosis of chondrosarcoma, among which the former two are independent factors.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.7
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• pp.4057-4059
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• 2013

Background: Fluorescence in situ hybridization (FISH) testing may be useful to screen for bladder carcinoma or dysplasia by detecting aneuploidy chromosomes 3, 7, 17 and deletion of the chromosome 9p21 locus in urine specimens. This study aimed to assess the sensitivity, specificity, positive and negative predictive value of FISH in a multi-ethnic population in Asia. Materials and Methods: Patients with haematuria and/or past history of urothelial cancer on follow-up had their voided urine tested with FISH. Patients then underwent cystoscopy/ureteroscopy and any lesions seen were biopsied. The histopathological reports of the bladder or ureteroscopic mucosal biopsies were then compared with the FISH test results. Results: Two hundred sixty patients were recruited. The sensitivity and specificity of the FISH test was 89.2% and 83.4% respectively. The positive (PPV) and negative predictive values (NPV) were 47.1% and 97.9%. By excluding patients who had positive deletion of chromosome 9, the overall results of the screening test improved: sensitivity 84.6%; specificity 96.4%; PPV 75.9% and NPV 97.9%. Conclusions: UroVysion FISH has a high specificity of detecting urothelial cancer or dysplasia when deletion of chromosome 9 is excluded. Negative UroVysion FISH-tests may allow us to conserve health resources and minimize trauma by deferring cystoscopic or ureteroscopic examination.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.2
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• pp.38-45
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• 2012

If an infant with congenital hearing loss is diagnosed in good time and get proper treatment as soon as possible, treatment effect could be maximized and the social costs could be considerably reduced. For these reasons, the medical equipment to screen hearing impairment objectively is needed. The ABR(auditory brainstem response) is typical diagnostic tools for this purpose but there are drawbacks in sense that it does not have frequency specificity and shows hearing information of usually high frequency band. The ASSR(auditory steady-state response) is excellent in frequency specificity, but the rate of wrong diagnosis is slightly high. In this study, we proposed the system which can measure both the ABR and the ASSR, and can show the objective and quantitative indices(Fsp and F-test). It was designed to allow various tests without hardware modification by minimizing hardware components and by increasing software roles. The objective assessment of the developed system was evaluated by experiments with 10 normal persons.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.1
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• pp.62-67
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• 1986

Forty-nine malting barley varieties were tested at 3 and 8 weeks after harvest, stored in natural glasshouse so as to investigate varietal variation of germinative energy(GE), capacity(GC) and water sensitivity(WS). The differences among GE, GC, promptness index(PI), and WS on paper at two moisture levels (4$m\ell$ and 8$m\ell$ tests) were great at 3 weeks after harvest, but small at 8 weeks after harvest. Excess water depressed the germination of dormant grains. The GE of whole varieties were excellent, but WS of only two varieties, CI 12062 and CI 15631 were bad at 8 weeks after harvest. So in the case of broad germplasm to be used for crossing materials, it is suggested that WS will be tested to screen good quality malting lines. WS was highly significantly correlated with GE, GC, and PI of 8 ml test, but was not with three factors of 4 $m\ell$ test. GE and WS were various with storage period, varieties and grain plumpness, indicated that breeding good grain-filling varieties and improving production practice for good grain-filling would be studied in the future.