• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.8
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• pp.1450-1455
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• 2007

Recently DSP chips are widely used in high quality car audio to achieve high quality sound and to process various sound sources, e.g. navigation, cell phones. In this paper, we developed a set of design tools useful for developing high quality car audio systems using Philips' SAF7730 car audio chips. The tool is consist of the GUI(Graphic User Interface) program running on the Windows operating system and the interface board which performs data conversion between RS232C and I2C protocols. The developed system has been successfully applied to commecial car audio design.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.193-200
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• 2020

This study used a structured questionnaire to analyze the effects of oral habits and stress on temporomandibular disorders in high school students. A total of 339 students attending high schools in Ulsan agreed to participate in the study. Data was analyzed using the SPSS Statistics ver. 18.0 for Windows program, t-test, one-way ANOVA, correlation, and regression analysis. Our results reveal that the temporomandibular disorder index is statistically correlated with the oral habit index, school life stress index, family life stress index, interpersonal stress index, and egosphere stress index (p≤0.01). The oral habit index had maximum influence on the temporomandibular disorder index. Moreover, higher the stress level in egosphere stress, greater significant differences were observed in the temporomandibular disorder index (p≤0.01). In other words, persistence of oral habits and non-addressal of stress increased the likelihood of experiencing temporomandibular disorders in adulthood. This was determined by the regression formula Y (temporomandibular disorder index) = 2.563 + 0.550X1 (oral habit index) + 0.134X2 (egosphere stress index). Thus, bad oral habits and stress in adolescence can be the potential cause of jaw joint disorders in adulthood. We believe that measures are needed to actively recognize and improve oral habits, and properly cope with stress during adolescence.

• Journal of the Optical Society of Korea
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• v.7 no.4
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• pp.230-233
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• 2003

This study describes the conceptual design of a soft x-ray microscope system based on a laserbased source for biomedical application with high resolution (${\leq}$50nm). The laboratory scale soft x-ray microscope consists of high power laser plasma x-ray source and grazing incidence mirrors with high reflectivity. The laser plasma source used for developing this system employs Q-switched Nd-YAG pulsed laser. The laser beam is focused on a tantalum (Ta) target. The Wolter type I mirror was used as condenser optics for sample illumination and as objective mirror for focusing on a detector. The fabrication of the Wolter type I mirror was direct internal cutting using ultraprecision DTM. A hydrated biological specimen was put between the two silicon wafers, the center of which was $Si_3N_4$ windows of 100㎚ thickness. The main issues in the future development work are to make a stable, reliable and reproducible x-ray microscope system.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.92-101
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• 2015

As one type of power quality (PQ) disturbance sources, high-speed rail (HSR) can have major impacts on the power supply grid. Providing timely and accurate warning information for PQ problems of HSR is important for the safe and stable operation of traction power supply systems and the power supply grid. This study proposes a novel warning approach to identify PQ problems and provide warning prompts based on the monitored data of HSR. To embody the displacement and status change of monitored data, multi-features of different sliding windows are computed. To reflect the relative importance degree of these features in the overall evaluation, an analytic hierarchy process (AHP) is used to analyse the weights of multi-features. Finally, a multi-features similarity algorithm is applied to analyse the difference between monitored data and the reference data of HSR, and PQ warning results based on dynamic thresholds can be analysed to quantify its severity. Cases studies demonstrate that the proposed approach is effective and feasible, and it has now been applied to an actual PQ monitoring platform.

• Journal of Korean society of Dental Hygiene
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• v.19 no.6
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• pp.919-929
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• 2019

Objectives: The purpose of this study was to comprehensively examine the relationship between periodontal disease and high-sensitivity C reactive protein (hs-CRP) level. Methods: This study was conducted using the data from the sixth Korea National Health and Nutrition Examination Survey. SPSS 18.0 for Windows was used for statistical analysis. The data were collected from 4,576 subjects aged ≥19 years. To analyze the association between periodontal disease and hs-CRP level, chi-squared test and logistic regression analysis were used. Results: Consequent to correcting all the disturbance variables, the moderate risk of hs-CRP was 1.39 times higher in patients with periodontal disease than in those without (OR=1.39; 95% CI:1.14-1.69), whereas the high risk of hs-CRP was 1.10 times but there was no statistical significance (OR=1.10; 95% CI:0.79-1.53). Conclusions: Periodontal disease contributes to raising the risk of systemic inflammation and hs-CRP from low to moderate. Periodontal disease is associated with an early rise in hs-CRP.

• Korean Journal of Human Ecology
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• v.18 no.2
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• pp.509-522
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• 2009

This is a basic study to improve air quality of school classrooms in winter time. The purposes are to check indoor thermal and air environment in school classrooms during winter and to analyze influencing factors on indoor environment. The measurements of students' physical elements with questionnaire surveys were carried out in a total of 6 classrooms. As a result, this research shows that the temperature of one classroom was below indoor thermal standard level, three classrooms had lack of heat, and two classrooms are heated much, which induce relatively low humidity. All of 6 classrooms had lack of ventilation, being high level of $CO_2$ concentration and 2 classrooms are in condition of high PM10 concentration. The majority of students(76%) answered that the cause of their 'heated space syndrome' is because of the lack of ventilation. Students' opening windows for ventilations is hardly carried out at normal times, except that indoor temperature is over standard. That is, we can suggest one of solutions, which is to enable students to operate heating and ventilating system by themselves according to students' physical condition.

• Korean journal of food and cookery science
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• v.25 no.6
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• pp.712-724
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• 2009

The purpose of this study was to examine the degree of concern about endocrine disruptors, the degree of recognition about the risk of endocrine disruptors towards humans, the degree of worry about the risk of endocrine disruptors towards ones self or family, information-obtaining behavior regarding endocrine disruptors, the degree of knowledge and the degree of behavior to decrease exposure to endocrine disruptors, and the degree of an educational need for endocrine disruptors in the dietary life of elementary school students. The data were collected from 162 students in Seoul, Incheon, Daejeon, Daegu, Busan and Gwangju. Frequencies, Cronbach's alpha, t tests, analysis of variance, Duncan's multiple range tests and chi-square tests were conducted using SPSS V.14.0 for WINDOWS. The results of this study were as follows. The degree of concern about endocrine disruptors was not high. The respondents obtained most of their information regarding endocrine disruptors from TV/radio. Respondents had difficulty in acquiring and understanding the information. Both the degree of knowledge and the degree of behavior to decrease exposure were not high. The respondents showed a high degree of educational need for endocrine disruptors, the most important was methods to prevent damage from endocrine disruptors followed by risk of endocrine disruptors.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.5
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• pp.926-932
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• 2007

Various research groups proposed various architecture of hardware VPN for the high performance VPN system. However, the VPN based on hardware researcher are focused only on the encryption acceleration. Soft based VPN is only useful when the network connection is slow. We have to consider the hardware performance (encryption/decryption processing capability, packet processing, architecture method) to implement hardware based VPN. In this paper, we have analysed architecture of hardware, consideration and problems for high-speed VPN system, From the result, we can choose the proper design guideline.

• Child Health Nursing Research
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• v.25 no.4
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• pp.496-506
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• 2019

Purpose: The purpose of this study was to examine the effects of a virtual reality simulation and a blended simulation on nursing care for children with asthma through an evaluation of critical thinking, problem-solving processes, and clinical performance in both education groups before and after the educational intervention. Methods: The participants were 48 nursing students. The experimental group (n=22) received a blended simulation, combining a virtual reality simulation and a high-fidelity simulation, while the control group (n=26) received only a virtual reality simulation. Data were collected from February 25 to 28, 2019 and analyzed using SPSS version 25 for Windows. Results: The pretest and posttest results of each group showed statistically significant improvements in critical thinking, problem-solving processes, and clinical performance. In a comparison of the results of the two education groups, the only statistically significant difference was found for critical thinking. Conclusion: Simulation-based education in child nursing has continued to involve high-fidelity simulations that are currently run in many programs. However, incorporating a new type of blended simulation, combining a virtual reality simulation and a high-fidelity simulation, into the nursing curriculum may contribute to the further development of nursing education.

• Journal of the Korea Society of Computer and Information
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• v.6 no.4
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• pp.104-109
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• 2001

In this paper, we designed a 3D shape measuring system with high speed and high measurement resolution using line-shaped sine stripes of a LCD projector We proposed an effective method to improve measurement efficiency for a 3D shape measuring system by finding the deficient shape information areas and recovering the shape information efficiently. We experimentally confirmed the improvement of measurement efficiency. Deficient shape information areas can be inevitably existed in a acquired image caused by the camera view angle and surface shapes of an object. The measurement efficiency is turned out to be improved by extracting these shadow areas and recovering the shape information efficiently using both a variable rated normalization and a variable sized phase recovering windows.