• Journal of Environmental Health Sciences
• /
• v.38 no.5
• /
• pp.386-392
• /
• 2012

Objectives: This study aims to evaluate the blood concentrations and dietary intake for 24-hour food duplicate of low level polycyclic aromatic hydrocarbons (PAHs). Design: The geometric means of the blood concentrations and dietary intake of 16 PAHs in college student candidates were simply compared with instrumental detection. Methods: The concentrations of 16 PAHs in venous blood and 24-hour food duplicates were analyzed with head-space solid phase microextraction (HS-SPME) of gas chromatography-mass spectrometry. Results: Naphthalene, acenaphthylene, pyrene, benz(a)anthracene, chrysene, and acenaphthene among the 16 analyzed PAHs were simultaneously detected both in venous blood and 24-hour food duplicate samples. Conclusion: The main exposure source of the six PAHs is thought to be oral intake from food through low level non-occupational exposure.

• Journal of Mechanical Science and Technology
• /
• v.14 no.6
• /
• pp.645-654
• /
• 2000

In this paper, low level control algorithms of a metal belt CVT are suggested. A feedforward PID control algorithm is adopted for line pressure based on a steady state relationship between the input duty and the line pressure. Experimental results show that feedforward PID control of the line pressure guarantees a fast response while reducing the pressure undershoot which may result in belt slip. For ratio control, a fuzzy logic is suggested by considering the CVT shift dynamics and on-off characteristics of the ratio control valve. It is found from experimental results that a desired speed ratio can be achieved at steady state in spite of the fluctuating primary pressure. It is expected that the low level control algorithms for the line pressure and speed ratio suggested in this study can be implemented in a prototype CVT.

• Journal of the Optical Society of Korea
• /
• v.15 no.4
• /
• pp.321-328
• /
• 2011

Various methods have been investigated to increase photon density in soft tissue, an important factor in low-level laser therapy. Previously we developed a compression-controlled low-level laser probe (CCLLP) utilizing mechanical negative compression, and experimentally verified its efficacy. In this study, we used Bezier curves to numerically simulate the skin deformation and photon density variation generated by the CCLLP. In addition, we numerically modeled changes in optical coefficients due to skin deformation using a linearization technique with appropriate parameterization. The simulated results were consistent with both human in vivo and porcine ex vivo experimental results, confirming the efficacy of the CCLLP.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.1279-1282
• /
• 2006

An ultra low-power down-conversion level shifter using low temperature poly-crystalline silicon thin film transistors is proposed for mobile applications. The simulation result shows that the power consumption of the proposed circuits is only 17% and the propagation delay is 48% of those of the conventional cross-coupled level shifter without additional area. And the measured power consumption is only 21% of that of the crosscoupled level shifter.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.11a
• /
• pp.496-496
• /
• 2007

Low level laser has various therapy effects. This paper performed the basic study for fabricating the low level laser therapy apparatus, and one of the goals of this paper was to make this apparatus used handily. The apparatus has been fabricated using the laser diode and microprocessor unit. The apparatus used a 660nm Laser diode for blood stream improvement and was designed for a pulse width modulation type to increase stimulation effects. In result, we could get the light power of 660nm wavelength and the 1~10Hz irradiation frequency could be controlled stably.

• Korean Journal of Remote Sensing
• /
• v.11 no.1
• /
• pp.31-45
• /
• 1995

The values of brightness temperature difference (BTD) between 11um and 12um infrared channels may reflect amounts of low-level water vapor and cloud types due to the different absorptivity for water vapor between two channels. A simple method of classifying cloud types at night was proposed. Two-dimensional histograms of brightness temperature of the 11um channel and the BTD between the split window data over subareas around characteristic clouds such as Cb(cumulonimbus), Ci(cirrus), and Sc(stratocumulus) was constructed. Cb, Ci and Sc can be classified by seleting appropriate thresholds in the two-dimensional histograms. And we can see amounts of low-level water vapor in clear area as well as cloud types in cloudy area in the BTD image. The map of cloud types and low-level water vapor generated by this method was compared with 850hPa and 1000hPa relative humidity(%) of numerical analysis data and nephanalysis chart. The comparisons showed reasonable agreement.

• Journal of Computing Science and Engineering
• /
• v.9 no.4
• /
• pp.204-213
• /
• 2015

Under the conditional independence assumption among local features, the Naive Bayes Nearest Neighbor (NBNN) classifier has been recently proposed and performs classification without any training or quantization phases. While the original NBNN shows high classification accuracy without adopting an explicit training phase, the conditional independence among local features is against the compositionality of objects indicating that different, but related parts of an object appear together. As a result, the assumption of the conditional independence weakens the accuracy of classification techniques based on NBNN. In this work, we look into this issue, and propose a novel Bayesian network for an NBNN based classification to consider the conditional dependence among features. To achieve our goal, we extract a high-level feature and its corresponding, multiple low-level features for each image patch. We then represent them based on a simple, two-level layered Bayesian network, and design its classification function considering our Bayesian network. To achieve low memory requirement and fast query-time performance, we further optimize our representation and classification function, named relation-based Bayesian network, by considering and representing the relationship between a high-level feature and its low-level features into a compact relation vector, whose dimensionality is the same as the number of low-level features, e.g., four elements in our tests. We have demonstrated the benefits of our method over the original NBNN and its recent improvement, and local NBNN in two different benchmarks. Our method shows improved accuracy, up to 27% against the tested methods. This high accuracy is mainly due to consideration of the conditional dependences between high-level and its corresponding low-level features.

• The Mathematical Education
• /
• v.51 no.3
• /
• pp.301-321
• /
• 2012

Since research has barely been done on the minority with low-achievement & low-SES in probability, this research attempted to search the change of their thinking level in the classes of probability and motivate them on the mathematical learning to feel confident in mathematics. We can say that the problems of the educational discriminations are due to the overlook on the individual conditions, situations, and environments. Therefore, in order to resolve some discrimination, 4 students who belonged to the minority group, engaged in the research, based on 10 units of the instructional materials designed for the research. As a result, for the student's thinking level, it was observed that they were improved from the 1st to the 3rd level in probability. Also, the researcher found that the adequate use of the encouragement, the praise, the direct explanation, and the scaffolding enabled them to prompt their learning motives and the increased responsibility on the learning. As time passed, the participants could share their mathematical knowledge and its concept with others, in the increased confidence.

• Journal of Environmental Science International
• /
• v.2 no.3
• /
• pp.179-191
• /
• 1993

This paper aims to know the characteristics of occurrence of the anomaly level and variability of the monthly precipitation in Kyeongnam, Korea. For this study, it was investigated 주e distribution of the annual and cont비y mean precipitation, the precipitation variability and its annual change, and the characteristics of occurrence of the anomaly level in Kyeongnam area the results were summarized as follows : 1) she mean of annual total precipitation averaged over Kyeongnam area is 1433.3mm. I'he spatial distribution of the annual total precipitation shows that in Kyeongnam area, the high rainfall area locates in the southwest area and south coast and the low rainfall area in an inland area. 2) Monthly mean precipitation in llyeongnam area was the highest in July(266.4mm) 각lowed by August(238.0mm), June(210.2mm) in descending order. In summer season, rainfall was concentrated and accounted for 49.9 percent of the annual total precipitation. Because convergence of the warm and humid southwest current which was influenced by Changma and typhoon took place well in this area. 3) The patterns of annual change of precipitaion variability can be divided into two types; One is a coast type and the other an inland type. The variability of precipitation generally appears low in spring and summer season and high in autumn and winter season. This is in accord with the large and small of precipitation. 4) The high frequency of anomaly level was N( Normal)-level and the next was LN( Low Informal) -level and 25(Extremely Subnormal)-level was not appeared in all stations. The occurrence frequency of N level was high in high rainfall area and distinguish성 in spring and summer season but the low rainfall area was not. hey Words : anomaly level, variability, precipitation, coast type, inland type.

• Journal of Nutrition and Health
• /
• v.37 no.5
• /
• pp.385-393
• /
• 2004

This study examined the relations of educational level and life-style behaviors to the obesity. A total of 507 male adults aged 30 - 50 years completed the self-reported questionnaires. Educational level was used for measuring socioeconomic status. Activity at work, leisure-time activity and TV watching were measured for life-style behaviors related to physical activity, and some demographic and family history of disease as well. Subjects were categorized as obese when BMI was equal to or over 25kg/$m^2$, in which 19.7％ resulted obesity. Using multivariate logistic regression, the association between the measured factors and obesity was assessed. The odds ratios (OR) for risk of obesity did not differ with either age or monthly income. Subjects who completed high school (OR = 0.36; 95％ CI = 0.20 - 0.66) or university (OR = 0.34; 95％ CI = 0.16 - 0.71) had lower risk of obesity than those with education below middle school. Those with moderate activity level at work (OR = 0.41; 95％ CI = 0.24 - 0.72) showed lower risk of obesity than in inactive ones. The subjects watching TV more than 3.5 hr/day presented higher risk of obesity (OR = 2.46; 95％ CI = 1.28 - 4.74), compared with those watching TV less than 1.5 hr/day. The higher risk of obesity observed in high level of leisure time activity than in low one was considered due to that physical activity at work and leisure-time might counteract each other. Educational level and activity at work or leisure-time activity or TV watching were jointed and categorized, and then OR for obesity was estimated. The extent of obesity risk at a given level of each work activity or leisure-time activity or TV watching was different depending the educational level, which was significantly high when educational level was below middle school. Educational difference had no effect on activity level at work. However, higher educational attainment increased the leisure activity and reduced TV watching (p＜0.05), indicating that low education tended to contribute to more sedentary life-style. The findings of this study is concluded that low education was related to obesity in adult males, and its relation can partly be explained through acquiring inactive life-style behaviors. Individuals with low education might be more susceptible to the risk factors of obesity.