• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.554-557
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• 2018

A catch basin sump is one major habitat for mosquito larvae, especially in urban areas. This study developed a device for mosquito control, specifically for the catch basin sump. It consists of a housing, is a little smaller than the catch basin sump, numerous floating materials, which the key component for mosquito control, and mesh nets. The small balls or pyramid-shaped floating materials inhibit mosquito enclosures and spawning by significantly decreasing the surface area of the water, which is essential for the mosquito life cycle. These floating materials were designed to keep the water flowing. The mesh nets were installed to prevent the outflow of floating materials. The efficiency of the floating materials was tested with 3 conditions (1, 2, 3 layers of floating materials) and a control group. The emergence of mosquito adults decreased by 20% in one-layer, and 70-80% in second and third layers. Therefore, this device is expected to certainly contribute to mosquito population control in the catch basin sump.

• Journal of the Ergonomics Society of Korea
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• v.10 no.2
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• pp.31-42
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• 1991

To understand the shape of the neck in a view of garment planning, principal component analysis has been appliedto the measurement of the neck. The neck surface development and the cross sections of the neck have been observed. The materials consist of the body mearsurements, the neck surface developments and the cross sec- tions of the necks of a total of 108 korean woman students. The difference between the right side and the left side of the neck has not been reconginiged. But the differenece among the height of the front neck point, that of the side neck point and that of the back neck point has been recognized. 2. The initial 41 items have been found having variety and duplication. So two criteria have been made to solve those problems and the selection of 34 items have been made by each criterion. 3. 43 and 34 items have been compared by means of accumulative ratios of contribution and of clearness within the meaning of principal component. As a result, 34 measurement items have been further anylysis. 4. As a result of principal component analysis on the 34 items, the four principal components have been found obtaines and inter-preted. The four principal components are 1) the thick of the neck, 2) the front neck-line on the waist basic pattern, basic pattern, 3) the shape of the neck surface development, and 4) the back neck-line on the waist basic pattern. 5. According to the graphic informations concerning these principal components, the meaning of these four principal components has been grasped on the visual. As a result, there is a large individual difference in the shape of neck.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.690-693
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• 2005

In this paper, probabilistic distribution of fatigue life of chassis component is determined statistically by applying the design of experiments and the Pearson system. To construct $p-\varepsilon-N$ curve, the case that fatigue data are random variables is attempted. Probabilistic density function(p.d.f) for fatigue life is obtained by design of experiment and using this p.d.f fatigue reliability about any aimed fatigue life can be calculated. Lower control arm and rear torsion bar of chassis component are selected as examples for analysis. Component load histories, which are obtained by multi-body dynamic simulation for Belsian load history, are used. Finite element analysis are performed using commercial software MSC Nastran and fatigue analysis are performed using FE Fatigue. When strain-life curve itself is random variable, probability density function of fatigue life has very little difference from log-normal distribution. And the case of fatigue data are random variables, probability density functions are approximated to Beta distribution. Each p.d.f is verified by Monte-Carlo simulation.

• Steel and Composite Structures
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• v.6 no.1
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• pp.33-53
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• 2006

The rotational behaviour of bolted extended end plate beam-to-column connections is evaluated in the context of the component method. The full moment-rotation response is characterized from the force-deformation curve of the individual joint components. The deformability of end plate connections is mostly governed by the bending of the column flange and/or end plate and tension elongation of the bolts. These components form the tension zone of the joint that can be modelled by means of "equivalent T-stubs". A systematic analytical procedure for characterization of the monotonic force-deformation behaviour of individual T-stub connections is proposed. In the framework of the component method, the T-stub is then inserted in the joint spring model to generate the moment-rotation response of the joint. The procedures are validated with the results from an experimental investigation of eight statically loaded extended end plate bolted moment connections carried out at the Delft University of Technology. Because ductility is such an important property in terms of joint performance, particularly in the partial strength joint scenario, special attention is given to this issue.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.9
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• pp.4451-4456
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• 2016

Background: In this study, we examined epidemiological aspects of dynamic changes in incidences of laryngeal cancer in male and female populations in Kazakhstan. Materials and Methods: Primary data were for registered patients with malignant laryngeal tumors in the whole country during the period of 1999-2014. Evaluation of changes in laryngeal cancer incidence in the population of Kazakhstan was performed using component analysis. Results: It was determined that the number of patients with laryngeal cancer in the whole country is decreasing although with conflicting impacts of different factors. Despite population growth (all - ${\Delta}_P=+66.1%$, men - ${\Delta}_P=+70.9%$ and women - ${\Delta}_P=+46.4%$), and aging (all - ${\Delta}_A=+45.1%$, men - ${\Delta}_A=+54.3$ and women - ${\Delta}_A=+22.2$), the reduction in risk of developing the disease (all - ${\Delta}_R=-165.6%$, men - ${\Delta}_R=-170.9%$ and women - ${\Delta}_R=-141.0%$) was overwhelming. Conclusions: This investigation was the first epidemiological study of dynamics of laryngeal cancer by component analysis in population of Kazakhstan. Implementation of the results of the study is recommended in management of anti-cancer activities for laryngeal cancer.

• ETRI Journal
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• v.40 no.6
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• pp.802-812
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• 2018

Disease discrimination using an electronic nose is achieved by measuring the presence of a specific gas contained in the exhaled breath of patients. Many studies have reported the presence of acetone in the breath of diabetic patients. These studies suggest that acetone can be used as a biomarker of diabetes, enabling diagnoses to be made by measuring acetone levels in exhaled breath. In this study, we perform a chemical sensor array optimization to improve the performance of an electronic nose system using Wilks' lambda, sensor selection based on a principal component (B4), and a stepwise elimination (SE) technique to detect the presence of acetone gas in human breath. By applying five different temperatures to four sensors fabricated from different synthetic materials, a total of 20 sensing combinations are created, and three sensing combinations are selected for the sensor array using optimization techniques. The measurements and analyses of the exhaled breath using the electronic nose system together with the optimized sensor array show that diabetic patients and control groups can be easily differentiated. The results are confirmed using principal component analysis (PCA).

• The Korean Journal of Ceramics
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• v.6 no.2
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• pp.134-137
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• 2000

Zirconia films stabilized b $Y_2O_3$, YSZ, films were deposition by metal organic chemical vapor deposition (MOCVD) onto various kind of substrates. $Y_2O_3$, $ZrO_2$and the mixtures of these two were deposited and characterized. The deposition rate, the film composition and the structure could be systematically varied through the $Y(C_{11}H_{19}O_2)_3$, Zr(O.t-$C_H_9)_4$source gas ratios and the deposition temperature. The Y/Zr ratio in YSZ film could be adjusted by controlling the ratio of $Y(C_{11}H_{19}O_2)_3$, Zr(O.t-$C_4H_9)_4$partial pressures. This is because the ratios of the deposition rates of Y and Zr atoms in $Y_2O_3$and $ZrO_2$films to those in YSZ films, Ф, are constant irrespective of the input gas concentration. However, the Y/Zr ratio was found to be smaller than that estimated based on the deposition rates of un-mixed $Y_2O_3$and $ZrO_2$films. This is because the Фs of Y and Zr atoms are not equal. The activation energy of $Y_2O_3$component in YSZ films was similar to that of $ZrO_2$component in YSZ films. These YSZ values were more than 4 times larger than those of un-mixed $Y_2O_3$or $ZrO_2$films.

• Current Photovoltaic Research
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• v.2 no.1
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• pp.28-35
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• 2014

High-efficiency in $Cu(In,Ga)Se_2$ (CIGS) solar cells were usually achieved on soda-lime glass substrates due to Na incorporation that reduces deep-level defects. However, this supply of sodium from sodalime glass to CIGS through Mo back electrode could be limited at low deposition temperature. Na content could be more precisely controlled by supplying Na from known amount of an outside source. For the purpose, an $Na_2S$ layer was deposited on Mo electrode prior to CIGS film deposition and supplied to CIGS during CIGS film. With the $Na_2S$ underlayer a more uniform component distribution was possible at $350^{\circ}C$ and efficiency was improved compared to the cell without $Na_2S$ layer. With more precise control of bulk and surface component profile, CIGS film can be deposited at low temperature and could be useful for flexible CIGS solar cells.

• Korean Journal of Materials Research
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• v.24 no.11
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• pp.573-577
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• 2014

The existing metal getters are invariably covered with thin oxide layers in air and the native oxide layer must be dissolved into the getter materials for activation. However, high temperature is needed for the activation, which leads to unavoidable deleterious effects on the devices. Therefore, to improve the device efficiency and gas-adsorption properties of the device, it is essential to synthesize the getter with a method that does not require a thermal activation temperature. In this study, getter material was synthesized using palladium oxide (PdOx) which can adsorb $H_2$ gas. To enhance the efficiency of the hydrogen and moisture absorption, a porous layer with a large specific area was fabricated by an etching process and used as supporting substrates. It was confirmed that the moisture-absorption performance of the $SiO_2/Si$ was characterized by water vapor volume with relative humidity. The gas-adsorption properties occurred in the absence of the activation process.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.9
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• pp.1169-1174
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• 2013

Most products are indeed governed by multiple failure modes. However, there are few cases in which reliability analysis applies to only one failure mode at a time. Furthermore, reliability data do not include information about failure modes, or the reliability analysis is performed using a representative failure mode. The Weibull shape parameter for failure modes is more important than one for products in the reliability qualification test. This paper presents reliability analysis methods for a mechanical component with multiple failure modes. These methods include the competing failure modes (CFM) method and the mixed Weibull method. Pneumatic cylinder test data with three failure modes are presented to estimate the shape parameter for each separate failure mode. In addition, reliability measures (B10 life, characteristic life) of the pneumatic cylinder considering three failure modes were compared with those assuming a single failure mode.