• Journal of the Korea Concrete Institute
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• v.16 no.6 s.84
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• pp.741-750
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• 2004

Air voids in hardened concrete have an important influence on concrete durability such as freeze-thaw resistance, surface scaling resistance, and water permeability, and they have been characterized by spacing factor Linear traverse and point count methods in ASTM standard have been used in estimating an air void system in hardened concrete. However, these methods require lots of time and efforts, further they are not repeatable. Image analysis method could be utilized In estimating an air void systems in hardened concrete with a developments of microscope, digital camera and computer program. The purpose of this study was to develope image analysis method and provide a guideline by comparing the results from ASTM method and image analysis method. The concerns were at air void content and diameter distribution, air voids system as well as spacing factors. The experimental variables included air content by air entrained agent (0, 0.01, $0.03\%$) and depth of specimen (top, middle, bottom). The result showed that it was possible to calculate spacing factor using image analysis technique, as well as air content, air diameter distribution, and air structure. This study also contributed in developing an reasonable and repeatable image analysis method.

• Tuberculosis and Respiratory Diseases
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• v.53 no.1
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• pp.56-65
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• 2002

A pulmonary epithelioid hemangioendothelioma (PEH) is a rare tumor with a vascular origin. A PEH can arise in many organ systems, such as the lung, liver, bone and soft tissues. It is a borderline malignancy but the clinical course is usually benign. In this report, we describe three cases of PEH. Case 1, a 61-year-old man, had nonspecific chest discomfort and the chest X-ray showed a solitary lung nodule. This nodule was diagnosed by an open lung biopsy. The pathologic findings including abundant necrosis, mitosis and hyperchromatic and pleomorphic nuclei, indicated a malignancy. The electron microscopic study showed Weibel-Palade bodies and the immunohistochemical stain for CD31 showed a positive reaction in the tumor cells, and linear staining along the vascular lumina. Case 2, a 34-year-old man, was admitted for an evaluation of multiple small nodules, incidentally detected a screening chest X-ray. The nodules were diagnosed by a immunohistochemical stain for the factor VIII-related antigen. Case 3, a 34-year-old woman, complained of left pleuritic chest pain. A simple chest film and the chest CT scan revealed multiple bilateral nodules and a left pleural effusion. An immunohistochemical stain for the factor VIII-related antigen was used to diagnose the nodules. Forth-one months after the diagnosis, she died of pulmonary insufficiency.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.11 no.4
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• pp.103-112
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• 1991

In this study, a numerical model was established and applied to simulate the steady-state groundwater and heat flow in an isotropic, heterogeneous, three dimensional aquifer system with uniform thermal properties and no change of state. This model was developed as an aid in screening large groundwater-flow systems as prospects for underground waste storage. Driving forces on the system are external hydrologic conditions of recharge from precipitation and fixed hydraulic head boundaries. Heat flux includes geothermal heat-flow, conduction to the land surface, advection from recharge, and advection to or from fixed-head boundaries. The model uses an iterative procedure that alternately solves the groundwater-flow and heat-flow equations, updating advective flux after solution of the groundwater-flow equation, and updating hydraulic conductivity after solution of the heat-flow equation. Dierect solution is used for each equation. Travel time is determined by particle tracking through the modeled space. Velocities within blocks are linear interpolations of velocities at block faces. Applying this model to the groundwater-flow system located in Jigyung-ri. Songla-myun, Youngil-gun. Kyungsangbuk-do, the groundwater-flow system including distribution of head, temperature and travel time and flow line, is analyzed.

• Journal of radiological science and technology
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• v.40 no.2
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• pp.311-316
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• 2017

Generally assessing bone mineral density (BMD) were performed on dual energy X-ray absorptiometry (DEXA) the same as dual energy CT (DECT) with a rapid-kVp switching. The purpose of this study is to compare the different of BMD value between DEXA and DECT method, and evaluate usefulness of DECT method. Using scanner for BMD measurements were GE, Healthcare Discovery 750 HD for DECT and Hologic QDR 4500W for DEXA. For compare BMD value in each method, scanned lumbar spine phantom and subjects visiting Korean National Cancer Center from April 2015 to December 2015, records of 50 patients. This study was approved by the Institutional Review Board. The mean BMD value measures for spine phantom and for subjects in each scanners presented strong correlation (r=0.948 with p<0.05 for phantom; r=0.635 with p<0.05 and Kendall's tau $({\tau})=0.46$ with p<0.05 for subjects) and linear relationship between DECT and conventional DEXA. DECT technique for BMD measurement will provide a very useful methodology without additional radiation dose.

• Radiation Oncology Journal
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• v.24 no.4
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• pp.211-216
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• 2006

$\underline{Purpose}$: An analysis of the infrastructure for radiotherapy in Korea was performed to establish a baseline plan in 2006 for future development. $\underline{Materials\;and\;Methods}$: The data were obtained from 61 radiotherapy centers. The survey covered the number of radiotherapy centers, major equipment and personnel. Centers were classified into technical level groups according to the IAEA criteria. $\underline{Results}$: 28,789 new patients were treated with radiation therapy in 2004. There were 104 megavoltage devices in 61 institutions, which included 96 linear accelerators, two Cobalt 60 units, three Tomotherapy units, two Cyberknife units and one proton accelerator in 2006. Thirty-five high dose rate remote after-loading systems and 20 CT-simulators were surveyed. Personnel included 132 radiation oncologists, 50 radiation oncology residents, 64 medical physicists, 130 nurses and 369 radiation therapy technologists. All of the facilities employed treatment-planning computers and simulators, among these thirty-two percent (20 facilities) used a CT-simulator. Sixty-six percent (40 facilities) used a PET/CT scanner, and 35% (22 facilities) had the capacity to implement intensity modulated radiation therapy. Twenty-five facilities (41%) were included in technical level 3 group (having one of intensity modulated radiotherapy, stereotactic radiotherapy or intra-operative radiotherapy system). $\underline{Conclusion}$: Radiation oncology in Korea evolved greatly in both quality and quantity recently and demand for radiotherapy in Korea is increasing steadily. The information in this analysis represents important data to develop the future planning of equipment and human resources.

• The Transactions of the Korea Information Processing Society
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• v.7 no.12
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• pp.3866-3873
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• 2000

In this paper, we investigates the long-term memory and the Correct answer rate of the foreign exchange data (Yen/Dollar) that is one of economic time series, There are many cases where two kinds of fractal dimensions exist in time series generated from dynamical systems such as AR models that are typical models having a short terrr memory, The sample interval separating from these two dimensions are denoted by kcrossover. Let the fractal dimension be $D_1$ in K < $k^{crossover}$,and $D_2$ in K > $k^{crossover}$ from the statistics mode. In usual, Statistic models have dimensions D1 and D2 such that $D_1$ < $D_2$ and $D_2\cong2$ But it showed a result contrary to this in the real time series such as NIKKEL The exchange data that is one of real time series have relation of $D_1$ > $D_2$ When the interval between data increases, the correlation between data increases, which is quite a peculiar phenomenon, We predict exchange data by neural networks, We confirm that $\beta$ obrained from prediction errors and D calculated from time series data precisely satisfy the relationship $\beta$ = 2-2D which is provided from a non-linear model having fractal dimension, And We identified that the difference of fractal dimension appeaed in the Correct answer rate.

• The Journal of the Petrological Society of Korea
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• v.18 no.2
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• pp.115-135
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• 2009

We have studied general orientational characteristics of microcracks distributed in Tertiary crystalline tuff from the northeastern part of the Gyeongsang Basin. 108 sets of microcracks on horizontal surfaces of 6 rock samples from Heunghae-eup and Cheongha-myeon, Pohang-si areas were distinguished by image processing. Those microcrack sets show a distinct linear array in 38 images. Whole domain of the directional angle(${\theta}$)-frequency(N) chart for crystalline tuff can be divided into 20 domains in terms of the phases of the distribution of microcracks. From the related chart, microcrack sets show preferred orientation which are coincident with the direction of vertical common joints. Consequently, the potential for macroscopic vertical joints in a rock body can be inferred from the directional angle showing high frequency in each domain of the related chart. This joint pattern is nearly the same in Mesozoic granites from Seokmo-do, Gwanghwa-gun. From the rose diagram for orientations of microcrack in crystalline tuff, orientations of dominant sets of microcracks in terms of frequency orders reflect representative orientations of maximum principal stress acted on crystalline tuff. Meanwhile, orientations of microcracks in crystalline tuff were compared with those of open microcracks in Bulgugsa granites from the southwestern part of the Gyeongsang Basin, and vertical rift/grain planes from Mesozoic granite quarries in Korea. In regional distribution chart, the agreement of distribution pattern between above two types of microcrack sets and vertical planes suggests that microcrack systems developed in crystalline tuff probably occur regionally in Mesozoic granites in Korea.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.6
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• pp.1249-1256
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• 2019

In this paper, we propose a new algorithm to remove acoustic feedback and noise in hearing aids. Instead of using the conventional FIR structure, this algorithm is a deep learning algorithm using neural network adaptive prediction filter to improve the feedback and noise reduction performance. The feedback canceller first removes the feedback signal from the microphone signal and then removes the noise using the Wiener filter technique. Noise elimination is to estimate the speech from the speech signal containing noise using the linear prediction model according to the periodicity of the speech signal. In order to ensure stable convergence of two adaptive systems in a loop, coefficient updates of the feedback canceller and noise canceller are separated and converged using the residual error signal generated after the cancellation. In order to verify the performance of the feedback and noise canceller proposed in this study, a simulation program was written and simulated. Experimental results show that the proposed deep learning algorithm improves the signal to feedback ratio(: SFR) of about 10 dB in the feedback canceller and the signal to noise ratio enhancement(: SNRE) of about 3 dB in the noise canceller than the conventional FIR structure.

• Journal of Nutrition and Health
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• v.53 no.2
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• pp.129-140
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• 2020

Purpose: Although the importance of life satisfaction in patients with chronic diseases has been emphasized, limited studies have been performed on the health-related quality of life (HRQoL) among elderly patients with chronic diseases. This study examined the HRQoL among Korean patients with diabetes aged 65 years or older. Methods: This study used data from the Korea National Health and Nutrition Examination Survey 2008-2016. The analysis included data of 2,353 elderly patients with diabetes aged 65 years or older who were aware that they had type 2 diabetes. Each participant was categorized into one of three age groups (65-69 years, 70-74 years, and ≥ 75 years). The EuroQol-5 Dimensions (EQ-5D) scale was computed to estimate the HRQoL. Multivariate linear regression analysis was used to compare the demographic characteristics, lifestyle characteristics, nutrient intake, and EQ-5D scores between the age groups. Results: The intake levels of most nutrients were similar in the three age groups, but the total energy intake levels were significantly lower, and the sodium intake levels were significantly higher in the older age groups (p < 0.001). In addition, all items of the EQ-5D index, except for anxiety/depression, tended to decrease with age. In particular, the oldest age group (≥ 75 years) showed significantly lower levels on most items and the EQ-5D index than those in the other age groups (p < 0.001). Conclusion: Elderly patients with type 2 diabetes may have low levels of life satisfaction, which worsens with increasing age. Therefore, it is important to develop and manage personalized guidelines and medical systems so that elderly patients have a higher quality of life for the remainder of their lives. The results of this study are expected to be used as basic data for the systematic management of diabetes in elderly Korean patients.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.634-643
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• 2013

This study purposed to examine how emotional intelligence affect undergraduate students' personal agency beliefs. For the purpose, this study conducted a questionnaire survey of 446 undergraduate students in metropolitan area. Data were analyzed by t-test, Pearson's correlation, correlation analysis, and linear regression analysis. The results were as follows. The regulation of emotion of emotional intelligence and capability beliefs of personal agency beliefs were significantly different according to sex and others' emotion appraisal of emotional intelligence and capability beliefs of personal agency beliefs were significantly different according to school level. Also, the others' emotion appraisal of emotional intelligence and capability beliefs of personal agency beliefs were significantly different according to religion existence. There was a correlation between the emotional intelligence and personal agency beliefs. The others' emotion appraisal, regulation of emotion and use of emotion of emotional intelligence have an impact on personal agency beliefs including capability beliefs and context beliefs, the explanation concerning capability beliefs(47%) and context beliefs(22%) was persuasive. Therefore, when undergraduate students have to make career decision for their future, in order to encourage personal agency beliefs which are related to motivational factors, the consequence of emotional intelligence was verified. It is necessary to establish many kinds of supporting systems to encourage the emotional intelligence and personal agency beliefs.