• Korean Journal of Health Education and Promotion
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• 제19권3호
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• pp.51-72
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• 2002

This research was conducted to understand and analyze the health-related behaviors of middle school students and get fundamental research data essential to provide efficient student guidance and public health service at school. The interview using Youth Risk Behavior Surveillance System(YRBSS). Translation and modification for Korean students of the YRBS. The Korean version of YRBS(Youth Risk Behavior Surveillance System) that translation and modification for Korean students of the YRBS developed by the Centers for Disease Control and Prevention(CDC)was used to assessment to health-related behaviors of youth. The interviewees were 1040 enrolled students at middle school in Daegu metropolitan city. YRBSS monitors six categories of priority health behaviors among youth and young adults behaviors that contribute to unintentional and intentional injuries; tobacco use; alcohol and other drug use, sexual behaviors that contribute to unintended pregnancy and sexually transmitted diseases(STDs)(including human immunodeficiency virus infection); unhealthy dietary behaviors; and physical activity. The result shows that over 30% of students rarely or never used safety belt and almost students were rarely or never wore a bicycle helmet. During the 12 months preceding the survey, 21.9% female students had felt so sad or hopeless almost every day for $\geq$ 2weeks in a row that they stopped doing some usually activities 20.5% of male middle school students have ever tried cigarette smoking. 26.2% of male students and 27.2% do female students had had over one drinks of alcohol during their lifetime(lifetime alcohol use). 47% of male students had had over one drinks of alcohol on $\geq$ 1 of the 30 days preceding the survey(current alcohol use). Over one half of female student were thought they were overweight. These results suggest that some risk behaviors be very prevalent in a korean middle school students and priority health-risk behaviors, which contribute to the leading cause of mortality and morbidity among youth and adult, often are establish during middle school age, extend into adulthood, are interrelated. Among both children and adults, the leading causes of death are closely linked to these behaviors. Among adults, chronic diseases such as cardiovascular disease, cancer, and diabetes are the national leading killers. Practicing healthy behaviors, such as eating low-fat, high-fruit-and-vegetable diets, getting regular physical activity, and refraining from tobacco use, would prevent many premature deaths. Because health-related behaviors are usually established in childhood, positive choices need to be promoted before damaging behaviors are initiated or become ingrained.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• 제6권2호
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• pp.155-162
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• 2008

Inventories to be disposed of, reference turnup, and source terms for CANDU spent fuel were evaluated for geological disposal system design. The historical and projected inventory by 2040 is expected to be 14,600 MtU under the condition of 30-year lifetime for unit 1 and 40-year lifetime for other units in Wolsong site. As a result of statistical analysis for discharge burnup of the spent fuels generated by 2007, average and stand deviation revealed 6,987 MWD/MtU and 1,167, respectively. From this result, the reference burnup was determined as 8,100 MWD/MtU which covers 84% of spent fuels in total. Source terms such as nuclide concentration for a long-term safety analysis, decay heat, thermo-mechanical analysis, and radiation intenity and spectrum was characterized by using ORIGEN-ARP containing conservativeness in the aspect of decay heat up to several thousand years. The results from this study will be useful for the design of storage and disposal facilities.

• Proceedings of the KSRS Conference
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1197-1199
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• 2003

ROCSAT-2 mission is to daily image over Taiwan and the surrounding area for disaster monitoring, land use, and ocean surveillance during the 5-year mission lifetime. The satellite will be launched in December 2003 into its mission orbit, which is selected as a 14 rev/day repetitive Sun-synchronous orbit descending over (120 deg E, 24 deg N) and 9:45 a.m. over the equator with the minimum eccentricity. National Space Program Office (NSPO) is developing a ROCSAT-2 Image Processing System (IPS), which aims to provide real-time high quality image data for ROCSAT-2 mission. A simulated ROCSAT-2 image, based on Level 1B QuickBird Data, is generated for IPS verification. The test image is comprised of one panchromatic data and four multispectral data. The qualification process consists of four procedures: (a) QuickBird image processing, (b) generation of simulated ROCSAT-2 image in Generic Raw Level Data (GERALD) format, (c) ROCSAT-2 image processing, and (d) geometric error analysis. QuickBird standard photogrammetric parameters of a camera that models the imaging and optical system is used to calculate the latitude and longitude of each line and sample. The backward (inverse model) approach is applied to find the relationship between geodetic coordinate system (latitude, longitude) and image coordinate system (line, sample). The bilinear resampling method is used to generate the test image. Ground control points are used to evaluate the error for data processing. The data processing contains various coordinate system transformations using attitude quaternion and orbit elements. Through the qualification test process, it is verified that the IPS is capable of handling high-resolution image data with the accuracy of Level 2 processing within 500 m.

• Journal of Korean Society of Industrial and Systems Engineering
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• 제20권44호
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• pp.357-368
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• 1997

본 연구에서는 의학분야의 생존분석에서 적용되어 왔던 Cox의 비례위험모형을 신뢰성예측 에 적용할 때의 분석절차 및 그에 따른 소프트웨어를 다룬다. 이 비례 위험모형은 신뢰성공학 분야에 적용될 경우 많은 잠재력을 가지고 있으나, 그 분야에 적용된 경우가 많지 않고, 이미 적용된 사례들도 잘못 적용되어 왔다는 지적이 많은 실정이다. 본 연구에서는 시스템 , 서브시스템, 부품수준에서의 각 라이프사이클을 거치며 얻어진 수명데이타를 분석하여 신뢰도를 예측할 수 있는 모형을 설정하고, 그에 따른 소프트웨어를 다루며, 이 방법의 개관, 장단점, 주의점등을 고찰한다.

• Journal of the Korean Chemical Society
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• 제54권1호
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• pp.55-58
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• 2010

Aliphatic and aromatic nitro compounds were selectively reduced to their corresponding amino derivatives in good yields using formic acid and CeY zeolite under monomode reactor. This system is found to be compatible with several sensitive functionalities. Beside the recycling result showed it had a long catalyst lifetime and could maintain activity even after being used for 20 cycles.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제23권8호
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• pp.638-644
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• 2010

We have carry out numerical simulation of the electric-optical characteristics of organic light emitting diodes with gradient-doped emitting layer which were reported to be effective in improving luminous efficiency and lifetime. In this paper, the basic structure is comprised of ITO/NPB/$Alq_3$:C545T[%]/$Alq_3$/LiF/Al, six devices by separating the emitting layer of $Alq_3$:C545T[%] were studied. As the result, the uniformly-doped devices exhibited superior luminous efficiency-current density characteristics over conventional undoped device. In the case of gradient-doped devices, electric-optical characteristics were improved similar to uniformed-doped devices, unusually the distribution of traped-charge density in the OLED devices was shown as the staircase.

• Membrane and Water Treatment
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• 제1권1호
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• pp.61-74
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• 2010

This paper will integrate models at different levels (from filtration, backwashing to chemical cleaning and membrane lifetime) that can be used to minimize overall operating costs of a dead-end ultra filtration process that is used for the purification of surface water. Integration of the models leads to a multi-level optimization problem (at different levels different objectives should be reached). This problem is solved as a MINLP. Systematic modelling and optimization of membrane systems is not extensively discussed in the scientific literature. In this paper the first steps are taken in the formulation of proper models and the use of systems engineering tools to come to real optimal operating conditions. The optimized variables are used to calculate fouling profiles which can subsequently be used as inputs for a control system that actually enforces the profiles to a real pilot plant.

• Tribology and Lubricants
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• 제29권5호
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• pp.318-323
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• 2013

Overheating in electrical motors results in detrimental effects such as degradation of the insulation materials, demagnetization of magnets, increases in Joule losses, and decreases in motor efficiency and lifetime. Thus, it is important to find ways to dissipate heat from the motor and to keep the motor operating at its most efficient temperature. In this study, a new design to guide air flow through a given brushless direct current (BLDC) motor is developed and the design is analyzed, specifically by using computational fluid dynamics (CFD) simulations. The results showed that the temperature distribution in the three proposed models is lower than that in the original model, although the speed of the cooling fan in the original model reaches a very high value of $15{\times}10^3$ rpm. The results also showed that CFD can be effectively used to simulate the heat transfer of BLDC motors.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권3호
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• pp.735-748
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• 2014

The fault-tolerance routing problem is one of the most important issues in the application of the Internet of Things, and has been attracting growing research interests. In order to maintain the communication paths from source sensors to the macronodes, we present a hybrid routing scheme and model, in which alternate paths are created once the previous routing is broken. Then, we propose an improved efficient and intelligent fault-tolerance algorithm (IEIFTA) to provide the fast routing recovery and reconstruct the network topology for path failure in the Internet of Things. In the IEIFTA, mutation direction of the particle is determined by multi-swarm evolution equation, and its diversity is improved by the immune mechanism, which can improve the ability of global search and improve the converging rate of the algorithm. The simulation results indicate that the IEIFTA-based fault-tolerance algorithm outperforms the EARQ algorithm and the SPSOA algorithm due to its ability of fast routing recovery mechanism and prolonging the lifetime of the Internet of Things.

• Journal of the Korea Safety Management & Science
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• 제15권4호
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• pp.73-80
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• 2013

Because the damages of corrosion resulting from the chloride ion are very serious, many research studies have been performed to measure the penetration depth of the chloride ion. However, there is a problem with data selection obtained from collection during experiments. In this study, it appears that the collected data are not conformed to a normal distribution. The result of this study will play a very important role, as a first step for the development and construction of a forecasting system to help determine a reliable service lifetime of marine structures.