• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.618-622
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• 2008

In this paper, we suggest new music composition algorithm based on fractal theory. User can define and control fractal shape by setting an initial state and production rules in L-System. We generate an asymmetric fractal tree based on L-System and probability. Then a music is generated by the fractal tree image using sonification techniques. We introduce two composition algorithm using the fractal tree. First, monophonic music can be generated by mapping x and y axis to velocity and pitch, respectively Second, harmonic music also can be generated by mapping x and y axis to time and pitch, respectively Using our composition algorithm, user can easily generate a music which has repeated pattern created by recursive feature of fractal, and a music which has structure similar to fractal tree image.

• Journal of the Korea Concrete Institute
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• v.16 no.2 s.80
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• pp.283-291
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• 2004

Recently, the construction of underwater structures has been gradually increased, but underwater concrete got some problems of quality deterioration and water contamination around cast-in-situ of construction. In addition, massive underwater structures such as LNG tank, underwater concrete structures of large and continuous high- strength subterranean wall under water are being demanded lower heat of hydration. In this paper, the mechanical properties of high-strength antiwashout underwater concrete (HAWC) containing with two kinds of mineral admixtures respectively were investigated. On the basis of these results, the pH value and suspended solids of HAWC manufactured in the mock-up test were 10.0$\Box$11.0 and 51 mg/${\iota}$ at 30 minutes later, respectively, initial and final setting time were about 30,37 hours, and the slump flow was 530$\pm$20Tm. In the placement at a speed of $27 m^3/hr$, there was no large difference in flowing velocity with or without reinforcing bar, and flowing slope was maintained at horizontal level. Compressive strength and elastic modulus of the cored specimen somewhat decreased as flowing distance was far; however, those of central area showed the highest value.

• Journal of Korean Critical Care Nursing
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• v.3 no.2
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• pp.1-11
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• 2010

Purpose: This study was designed to identify the factors affecting healing of Stage 2 pressure ulcer in an acute care facility in Korea. Methods: 286 Stage 2 pressure ulcers of 145 patients were examined. Data were collected in the period between October $1^{st}$, 2006 and September $30^{th}$, 2007. Data were analyzed with Kaplan-Meier survival analysis for cumulative recovery rate of Stage 2 pressure ulcers. Cox proportional hazard model was used to examine effects of multiple variables simultaneously. Results: Out of 286 initial Stage 2 pressure ulcers, 204 (71.3%) pressure ulcers healed completely. The median time to heal was 15 days according to Kaplan-Meier survival analysis. Cox proportional hazard model showed that the Stage 2 pressure ulcers healed more quickly when pressure redistribution surfaces were used (p<.001, HR=2.184), patients were administered with vitamins (p= .038, HR=1.451), and the size of the pressure ulcers were small (${\leq}3.0cm^2$, p= .006, HR=1.765). Conclusion: The factors contributing to the healing of Stage 2 pressure ulcer in an acute care setting were the application of pressure redistribution surface, small ulcer size (${\leq}3.0cm^2$), and the administration of vitamins.

• Archives of Plastic Surgery
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• v.41 no.4
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• pp.414-417
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• 2014

Serratia marcescens (S. marcescens) emerged as an opportunist in the setting of immunodeficiency in the 1970s, when serious infections occurred in San Francisco hospitals after USA. Navy experiments had aerosolized the bacteria to study biologic warfare. We investigate the risks of S. marcescens in San Franciscans who undergo mastectomy with implant reconstruction. From 2007 to 2011, the senior author took breast capsule cultures for all patients at the time of tissue expander exchange/explant. Of the 142 women who had reconstruction, 23 had positive cultures. Only the two patients who were positive for S. marcescens developed clinical infections that required explantation. Both had postoperative chemotherapy with transient neutropenia, and both had close ties to San Francisco. Clinical signs of infection emerged for both patients months after initial surgery, despite having previously well healed incisions. Other patients were culture positive for Pseudomonas, Proteus, Enterococcus and MRSA and did not develop require explant. While the link between San Francisco and S. marcescens is controversial, a patient's geography is a simple screening tool when considering postoperative risks, especially in the immunocompromised. Closer monitoring for neutropenia during chemotherapy, and a lower threshold to administer S. marcescens targeted antibiotics may be warranted in these patients.

• Korea-Australia Rheology Journal
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• v.19 no.2
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• pp.61-66
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• 2007

The aggregation characteristics of red blood cells (RBCs) are known as important factors in the microvascular flow system, and increased RBC aggregation has been observed in various pathological diseases, such as thrombosis and myocardial infarction. This paper describes a simple microfluidic device for measuring the RBC aggregation by integrating a microfluidic slit rheometry and laser-backscattering technique. While a decreasing-pressure mechanism was applied to the microfluidic rheometry, a syllectogram (the light intensity versus time) showed an initial increase and a peak caused by the high shear stress-induced disaggregation, immediately followed by a decrease in the light intensity due to RBC aggregation. The critical shear stress (CST) corresponding to the peak intensity was examined as a new index of the RBC aggregation characteristics. The CST of RBCs increased with increasing aggregation-dominating protein (fibrinogen) in the blood plasma. The essential feature of this design was the combination of the rheometric-optic characterization of RBC aggregation with a microfluidic chip, which may potentially allow cell aggregation measurements to be easily carried out in a clinical setting.

• Computers and Concrete
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• v.32 no.2
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• pp.185-206
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• 2023

This article aimed to explore the optimization of mineral admixtures and retarding admixture for high-performance concrete. In essence, fresh concrete can be regarded as a mixture in which both coarse and fine aggregates are suspended in a cement-based matrix paste. Based on this view, the test procedure was divided into three progressive stages of binder paste, mortar, and concrete to explore their rheological behavior and mechanical properties respectively. At each stage, there were four experimental control factors, and each factor had three levels. In order to reduce the workload of the experiment, the Taguchi method with an L9(3⁴) orthogonal array and four controllable three-level factors was adopted. The test results show that the use of the Taguchi method effectively optimized the composition of high-performance concrete. The slump of the prepared concrete was above 18 cm, and the slump flow was above 50 cm, indicating that it had good workability. On the other hand, the 28-day compressive strength of the hardened concretes was between 31.3-59.8 MPa. Furthermore, the analysis of variance (ANOVA) results showed that the most significant factor affecting the initial setting time of the fresh concretes was the retarder dosage, and its contribution percentage was 62.66%. On the other hand, the ANOVA results show that the most significant factor affecting the 28-day compressive strength of the hardened concretes was the water to binder ratio, and its contribution percentage was 79.05%.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.1
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• pp.76-84
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• 2017

This study selected a method which uses high early strength cement as a way to reduce the curing time and curing energy source of concrete secondary products and reviewed the improvement in the initial strength of concrete secondary products setting the target strength of the concrete capable of removing the form to 15MPa and the curing time to 6 hours. As a result of the test, the only specimen which achieved the form removal strength of 15 MPa only through atmospheric curing within the target curing time of 6hours was ACC-100, and the specimens of TRC-100 and TRC-50 satisfied the values of 6 hours and 15MPa through steam curing. However, we could see that it was difficult to secure workability in the case of the specimen of ACC-100 due to its high rapid setting property and a retarder such as anhydrous citric acid was required to be used to improve the workability. When we look into the pattern following changes in the water to binder ratio, while, in the case of stream curing, OPC-100, TRC-100, and TRC-50 were all found to satisfy achievement of the form removal strength within 6hours as the water to binder ratio decreased, in the case of atmospheric curing, TRC-100, and TRC-50 achieved 15MPa within 12hours.

• Journal of Korea Multimedia Society
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• v.9 no.10
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• pp.1266-1275
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• 2006

In this paper, we propose a real-lime face detection and tracking algorithm using AdaBoost(Adaptive Boosting) algorithm. The proposed algorithm consists of two levels such as the face detection and the face tracking. First, the face detection used the eight-wavelet feature models which ate very simple. Each feature model applied to variable size and position, and then create initial feature set. The intial feature set and the training images which were consisted of face images, non-face images used the AdaBoost algorithm. The basic principal of the AdaBoost algorithm is to create final strong classifier joining linearly weak classifiers. In the training of the AdaBoost algorithm, we propose SAT(Summed-Area Table) method. Face tracking becomes accomplished at real-time using the position information and the size information of detected face, and it is extended view region dynamically using the fan-Tilt camera. We are setting to move center of the detected face to center of the Image. The experiment results were amply satisfied with the computational efficiency and the detection rates. In real-time application using Pan-Tilt camera, the detecter runs at about 12 frames per second.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.609-616
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• 2021

In this experimental, water-repellent powder, which is a metal salt-based inorganic substance, and natural zeolite powder, which is a pozzolan-based material, were mixed into cement mortar, and their physical properties and resistance to moisture were confirmed. It was confirmed that the test specimen using natural zeolite at the same time had excellent resistance in the water permeation test and the chloride penetration test as compared with the test specimen in which the inorganic metal salt-based water-repellent powder was mixed alone. When a metal salt-based water-repellent powder is used, it cannot be uniformly dispersed inside water due to its insoluble property, and is limited to the surface. When used at the same time as natural zeolite, the setting time at the initial stage of hydration is fast due to the pozzolan reaction, and the water-repellent powder adheres to the porous of the natural zeolite and is evenly distributed inside the test specimen to generate some water resistance.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.578-584
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• 2021

This study comparatively analyzed the properties of hydration reaction and strength development of four types of pond ash(PA) and fly ash(FA), aiming for the effective use of PA. The PA whose chlorine content was highest due to the seawater movement method had a faster setting time, higher cumulative heat, and greater initial strength development than those of FA due to the acceleration of the cement hydration reaction. However, the activity factor increase rate decreased after seven days of curing due to the rapid generation of early hydrates. The PA that contained impurities, such as a large amount of unburned carbon, had a delayed setting time due to the lower hydration reaction. Moreover, the strength was degraded in all curing ages. The PA whose chlorine content was lower due to the freshwater movement method and the amorphous content exhibited similar hydration reactivity and strength development characteristics compared to that of FA. The thermogravimetric analysis results verified that it had a similar level of Ca(OH)₂ consumption and pozzolanic reactivity with that of FA. Conclusively, it is necessary to expand the application of the freshwater movement method and manage the ignition loss to raise PA's usability.