• Communications for Statistical Applications and Methods
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• v.29 no.6
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• pp.655-664
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• 2022

On the motivation by an integrative study of multi-omics data, we are interested in estimating the structure of the sparse cross correlation matrix of two high-dimensional random vectors. We rewrite the problem as a multiple testing problem and propose a new method to estimate the sparse structure of the cross correlation matrix. To do so, we test the correlation coefficients simultaneously and threshold the correlation coefficients by controlling FRD at a predetermined level α. Further, we apply the proposed method and an alternative adaptive thresholding procedure by Cai and Liu (2016) to the integrative analysis of the protein expression data (X) and the mRNA expression data (Y) in TCGA breast cancer cohort. By varying the FDR level α, we show that the new procedure is consistently more efficient in estimating the sparse structure of cross correlation matrix than the alternative one.

• Health Policy and Management
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• v.27 no.4
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• pp.276-283
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• 2017

Background: Electronic cigarette (e-cigarette) has rapidly increased. Even though e-cigarettes are actually not smoking cessation alternative supplies, some people perceive them as smoking cessation alternative supplies. The purpose of this study is to identify the relationship between e-cigarette experiences and smoking cessation behaviors among Korean adults. Methods: Cross-sectional data was collected from 7,550 participants of Korea National Health and Nutrition Examination Survey in 2014. A total of 867 participants who were current smokers were enrolled in this study. Multi-variable logistic regression analysis were performed to identify the relationship between the smoking cessation behavior and the e-cigarette experience. Results: The e-cigarette experience rate of current smokers was 22.1%. The e-cigarette experience rate was higher in groups with the higher income, the higher education level, and the white collar jobs. Smokers with experience of smoking cessation (odds ratio [OR], 3.03; 95% confidence interval [CI], 1.67 to 5.76) and with intention to smoking cessation in the future (OR, 1.59; 95% CI, 1.05 to 2.43) were more likely to experience the e-cigarette. Especially, smokers who used smoking cessation alternative supplies were more likely to experience the e-cigarette than smokers who did not use it (OR, 2.87; 95% CI, 1.59 to 5.18). Conclusion: We confirmed that e-cigarette experiences were associated with smoking cessation experience, smoking cessation plan, and use of smoking cessation aid among smokers in Korea. Additional studies should be continued to confirm whether e-cigarette are continuously influencing the smoking cessation of current smokers in South Korea as one of the smoking cessation alternative supplies.

• Environmental Analysis Health and Toxicology
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• v.30
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• pp.7.1-7.7
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• 2015

Objectives The widely promising applications of graphene nanomaterials raise considerable concerns regarding their environmental and human health risk assessment. The aim of the current study was to evaluate the toxicity profiling of graphene family nanano-materials (GFNs) in alternative in vitro and in vivo toxicity testing models. Methods The GFNs used in this study are graphene nanoplatelets ([GNPs]-pristine, carboxylate [COOH] and amide [$NH_2$]) and graphene oxides (single layer [SLGO] and few layers [FLGO]). The human bronchial epithelial cells (Beas2B cells) as in vitro system and the nematode Caenorhabditis elegans as in vivo system were used to profile the toxicity response of GFNs. Cytotoxicity assays, colony formation assay for cellular toxicity and reproduction potentiality in C. elegans were used as end points to evaluate the GFNs' toxicity. Results In general, GNPs exhibited higher toxicity than GOs in Beas2B cells, and among the GNPs the order of toxicity was pristine > $NH_2$ > COOH. Although the order of toxicity of the GNPs was maintained in C. elegans reproductive toxicity, but GOs were found to be more toxic in the worms than GNPs. In both systems, SLGO exhibited profoundly greater dose dependency than FLGO. The possible reason of their differential toxicity lay in their distinctive physicochemical characteristics and agglomeration behavior in the exposure media. Conclusions The present study revealed that the toxicity of GFNs is dependent on the graphene nanomaterial's physical forms, surface functionalizations, number of layers, dose, time of exposure and obviously, on the alternative model systems used for toxicity assessment.

• Clean Technology
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• v.14 no.2
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• pp.103-109
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• 2008

In this study, in order to develop evaluation method of the cleaning efficiency of residual flux which remains on the surface after soldering with solder paste, a specially designed metal tool is used to reduce spread uncertainty of flux while soldering. Using this tool, the measurement of cleaning efficiency of flux after soldering for some typical alternative semi-aqueous cleaners and 1,1,1-TCE by weighing method was conducted. As the test result of cleaning efficiency for each cleaner at several different cleaning times, the precision of the data is confirmed to within about 4% relative standard deviation (RSD) range. So, it is considered that this would be a good evaluation method for evaluating the cleaning efficiency of the residual flux which remains after solder paste soldering in the alternative cleaning. The results of this test method shows that the cleaning efficiency of ST 100SX and Neozal 750H in the cleaning of residual flux was better than other semi-aqueous cleaners, but its cleaning efficiency was clearly inferior to 1,1,1-TCE.

• Journal of the Korean Society for Railway
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• v.14 no.1
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• pp.31-38
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• 2011

Turnkey and alternative-design contracts was introduced operation in the country from january 2004 to February 2010. this was introduced operation. The selecting method of contractor for turnkey projects has being operated by an open forum type that consists of technical committee and appraisal committee in an integrated design approach deliberations. But to improve the operation of the problems, the government is operating design review committee consisting of the central, local and special design advisory committee in march 2010. But this system has also been suggested as still problems, too many contracts by large companies, increasing of design cost and excessive competition. This study is intended to contribute that turnkey and alternative-design contracts can be well operated in domestic construction markets. In this paper suggests some improvement methods and operational problems caused from application of an open forum type for selecting contractor of turnkey project.

• International Journal of Highway Engineering
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• v.15 no.1
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• pp.23-36
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• 2013

PURPOSES: The problem under this circumstance is that the erosion not only drops strength of the steel dowel bar but also comes with volume expansion of the steel dowel bar which can reduce load transferring efficiency of the steel dowel bar. To avoid this erosion problem, alternative dowers bars are developed. METHODS: In this study, the bearing stresses between the FRP tube dowel bar and concrete slab are calculated and compared with its allowable bearing stress to check its structural stability in the concrete pavement. These comparisons are conducted with several cross-sections of FRP tube dowel bars. Comprehensive laboratory tests including the shear load-deflection test on a full-scale specimen and the full-scale accelerated joint concrete pavement test are conducted and the results were compared with those from the steel dowel bar. RESULTS: In all cross-sections of FRP tube dowel bars, computed bearing stresses between the FRP tube dowel bar and concrete slab are less than their allowable stress levels. The pultrusion FRP-tube dowel bar show better performance on direct shear tests on full-scale specimen and static compression tests at full-scale concrete pavement joints than prepreg and filament-winding FRP-tube dowel bar. CONCLUSIONS: The FRP tube dowel bars as alternative dowel bar are invulnerable to erosion that may be caused by moisture from masonry joint or bottom of the pavement system. Also, the pultrusion FRP-tube dowel bar performed very well on the laboratory evaluation.

• International Journal of Highway Engineering
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• v.2 no.2
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• pp.149-161
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• 2000

The stiffness of the subbase materials is represented by the resilient modulus, $M_R$, which are very important properties in the mechanistic design of flexible pavement system. However, the cyclic $M_R$ testing method is too complex, expensive, and time consuming to be applicable on a production basis. In this study, the alternative $M_R$ testing technique for subbase materials was developed using a free-free resonant column (FF-RC) test considering deformational characteristics of subbase materials. To estimate the deformational characteristics of subbase materials, effects of strain amplitude and mean effective stress on modulus of subbase materials were investigated. The $M_R$ values determined by alternative testing procedures matched well with those determined by standard $M_R$ test, showing the capability of the proposed methods being used in determining $M_R$ values.

• Korean Journal of Head & Neck Oncology
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• v.21 no.1
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• pp.21-25
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• 2005

Background and Objectives: The popularity of complementary and alternative medicine(CAM) has grown at an astonishing rate in recent years. Because patients are interested in CAM and want to use it, physicians also should be concerned about CAM and know about the current situation of its usage. In this study, we tried to determine the prevalence of CAM use in the patients with head and neck cancer and correlate with demographics and tumor characteristics. Materials and Methods: A total of 87 patients with head and neck cancer previously treated with surgery at Seoul National University Hospital from March through June, 2004 were enrolled in this study. The patients were completed, questionnaire about the use of CAM and demographic information. Tumor characteristics were obtained from the patient's medical records. Results: Of the 87 patients, 33 patients(37.9%) use at least one CAM. There was no statistically significant correlation between patient's data and prevalence of CAM use. Of those patients using CAM, 16(48.5%) of 33 were using 2 or more therapies. The majority of agents used by patients in this study are mushrooms such as Phellinus and Reishi, followed by dietary therapy. A majority(60.6%) of patients were introduced to alternative medicine by friends or family members. Conclusion: Considerable cancer patients use CAM. Head and neck oncologists should inform themselves about CAM to counsel and educate the patients. Further scientific investigations on promising CAM agents may help advance cancer treatment.

• Journal of Korean Neurosurgical Society
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• v.64 no.1
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• pp.60-68
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• 2021

Objective : Until recently, the transfemoral approach (TFA) was used as the primary method of arterial approach in acute ischemic stroke (AIS). However, TFA resulted in longer reperfusion times and worse outcomes in the mechanical thrombectomy (MT) of patients with complex aortic arches and significant carotid tortuosity. We found that the transradial approach (TRA) is a more favorable alternative approach for MT in such cases. Methods : We performed a retrospective review of our institutional database to identify 202 patients who underwent MT for AIS between February 2015 and December 2019. Patient characteristics, cause of TFA failure, procedure time, intra-procedural complications, and outcomes were recorded. Results : Eleven (5.4%) of 202 patients, who underwent MT for AIS, crossed over to TRA for recanalization, and eight (72%) of 11 achieved successful recanalization (≥modified Treatment in Cerebral Infarction 2b). The mean age (mean±standard deviation [median]) was 82.3±6.6 (76) years, and five of the 11 patients were male. The last seen normal to puncture time was 467.9±264.72 (264) minutes; baseline National Institutes of Health Stroke Scale score was 28.9±14.5 (16). Six (55%) of the 11 patients had right vertebrobasilar occlusions, and the remaining five (45%) had anterior circulation occlusive disease. The time from groin puncture to final recanalization time (overall procedural time) was 78.0±20.1 (62) minutes. The mean crossover time from TFA to TRA was 45.2±10.5 (41) minutes. The mean time from radial puncture to final recanalization was 33.8±10.5 (28) minutes. Distal thrombus migration events in previously unaffected territories occurred in 3/8 patients (37%). At 90 days, three patients (28%) had a favorable clinical outcome. Conclusion : Although rare, failure of TFA has been known to occur during MT for AIS. Our results demonstrate that TRA may be an alternative option for AIS intervention for select patients with subsequent timely revascularization. However, the incidence of distal thrombus migration was high, and the first puncture to reperfusion time was prolonged because of the time taken for the crossover to TRA after failure of TFA. This study provides some evidence that the TRA may be a viable alternative option to the TFA for MT of AIS.

• Journal of Pharmacopuncture
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• v.24 no.2
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• pp.84-90
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• 2021

Objectives: Our study aimed to determine the attitudes of second- and final-year medical students and doctors (teaching faculty) of modern medicine towards complementary and alternative medicine (CAM) using the Complementary, Alternative, and Integrative Medicine Attitude Questionnaire (CAIMAQ). Methods: We invited 248 second-year medical students, 245 final-year medical students, and 48 faculty members to participate in the study. The CAIMAQ consists of 30 items, divided into five categories assessing various aspects of CAM, and scored using a 7-point Likert scale. The median scores obtained were compared between groups; a p-value < 0.05 was considered statistically significant. Results: A total of 138 medical students and faculty responded and participated in the study, of which, 24 (17.4%) were faculty, 40 (29%) were final-year medical students and 74 (53.6%) were second-year medical students. The overall attitude towards the various CAM concepts and therapies was positive. In general, the faculty were significantly less likely to consider referring patients for CAIM treatments, integrating them with conventional medicine, referring patients to alternative healthcare providers, considering the use of subtle energy fields as an ethical form of treatment, or considering CAIM treatments to be less invasive and harmful compared with conventional medicine. There was no significant difference in the attitudes of second- and final-year students. Conclusion: The attitude of medical students and doctors towards CAM is positive, and although the medical faculty have reservations in recommending specific types of CAM therapies or integrating them with conventional care, building evidence for supporting CAM therapies in specific diseases is likely to increase its uptake among health care professionals.