• Journal of the Korean Society for Railway
• /
• v.11 no.2
• /
• pp.158-164
• /
• 2008

Abstract Infiltration of rainfall that may lead to reduce resistance force due to reduction of matric suction and to increase driving force due to increase of self weight makes the slope fail. There are many specifications to make slope stable based on factor of safety. Although result of slope stability analysis satisfy the specifications, slope failures triggered by rainfall are frequently occurred in reality because slope stability analysis cannot consider uncertainty of each soil properties. This is why conventional analysis has limitation and development of alternative method is needed. So it is suggested to adopt the reliability analysis rather than design based on factor of safety into designing safer structure. Through the evaluation of handicaps for the factor of safety based design, calculation of soil properties by site investigation, and reliability analysis considering distribution of each soil properties, distribution of failure probability in railway slope is obtained. Then, Risk assessment of slopes in Korean railway is executed from the results. Damage loss and incoming loss are considered as the loss. Using these results, it is possible to make proper countermeasure or efficient maintenance.

• Journal of Korean Society for Atmospheric Environment
• /
• v.20 no.E1
• /
• pp.35-41
• /
• 2004

Aerosol wall loss is an important factor affecting smog chamber experiments, especially with chambers made of Teflon film. In this work, the aerosol wall loss was investigated in 2.5 and $5.8-m^3$ cubic-shaped Teflon film chambers filled with ambient air. The natural change in the particle size distribution was measured using a scanning mobility particle sizer in a dark environment. The rate of aerosol wall loss was obtained from the deposition theory suggested by Crump and Seinfeld (1981). The measured rates of aero-sol wall loss were In a good agreement with the theoretical and experimental values given by McMurry and Rader (1985), implying that the electrostatic effect enhances particle deposition on the chamber wall. The significance of aerosol wall loss correction was demonstrated with the photochemical reaction experiments using the ambient air.

• Journal of the Korean Statistical Society
• /
• v.24 no.1
• /
• pp.257-266
• /
• 1995

Consider a p-variate $(p \geq 4)$ normal distribution with mean $\b{\theta}$ and identity covariance matrix. For estimating $\b{\theta}$ under a quadratic loss we investigate the behavior of risks of Stein-type estimators which shrink the usual estimator toward the mean of observations. By using concavity of the function appearing in the shrinkage factor together with new expectation identities for noncentral chi-squared random variables, a characterization of estimators with nondecreasing risk is obtained.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.20 no.7
• /
• pp.626-630
• /
• 2007

The AC loss is an important issue in the design of the high temperature superconductor (HTS) power cables and fault current limiters. In these applications, a cylindrical HTS conductor is often used. In commercialization of these apparatuses, AC loss is a critical factor but not elucidated completely because of complexities in its measurement, e.g. non-uniform current distribution and phase difference between currents flowing in an individual HTS tape. We have prepared two cylindrical conductors composed of a Bi-2223 tape with different critical current density. In this paper, the AC loss characteristics of the conductors have been experimentally investigated and numerically analyzed. The result show that the measured losses for two conductors are not dependent on both arrangements and contact positions of a voltage lead. This implies that most of loss flux is only in the conductors. The loss for the Bi-2223 conductor with low critical current density is in good agreement with the calculated loss from Monoblock model, whereas the loss measured for the Bi-2223 conductor with high critical current density doesn't coincide with the loss calculated from the Monoblock model. The measured loss is also different from numerically calculated one based on the polygon model especially in low transport current.

• Journal of Haehwa Medicine
• /
• v.2 no.2
• /
• pp.219-246
• /
• 1993

In 1991, Obesity rate of South Korea has reached to 18.7%. Because of economical development, the pattern of diet is exchanged from carbohydrate to rich protein and fat. The more problem is not only obesity of adult but also one of little child. Obesity is induced to diabetes mellitus, hypertension, artherosclerosis, hyperlipoidemia. heart and C.V.A disease, etc. In Woman, special important ploblem is the complex of beauty about Woman's figure. In Oriental Medicine, the factor of obesity is mainly regarded as dampness. And there are many treatments and methods to body weight loss, but obesity patients dislike to use them because of their side effects and inconvenience, intolerance. Now ear acupuncture is applied on so many disease because of its easy handly, non-side effect and high efficiency in clinics. Here obesity acupuncture is used to ear and whole body acupuncture. Because they react eachother for lack point. Therefore, in order to investigate the effect of obesity acupuncture and develop non-drug, non-starvation etc, we analyzed 453 the cases of body weight loss patients treated with ear and whole body acupuncture in Oriental Medicine Hospital of Jeon-Ju Woo-Sug University from April.1.1992. to March.17. 1993. The results were summarized as follows. 1. Distribution of sex ; male (4.4%), Female(95.6%) 2. Distribution of age in descending order ; 30s, 20s, 40s, 10s, 50s, below 10s, abowe 60s. The 20s-30s are group made up 60.7% of the group. 3. Distribution of occupation in descending order; housewife, student, service, salaried, merchant, teacher, farmer, inoccupation. 4. Distribution of human coporal constitution in descending order : Tae-Eum-In, So-Eum-In, So-Yang-In. 5. Distribution of body height and weight, 155-164cm ; 71.1%, 60-70kg, 74.6% are majority. 6. Distribution of weight variation, 2-6kg(71.0%) is majority, also 13-14kg(0.4%). 7. Distribution of duration in descending order ; 1-3 years, 3-6 years, 1-12months, above 10 years but in success, 1-12 months, 1-3 years, 3-6 years, above 10 years. Therefore, we know that the shorter duration of obesity is, the more loss of body weight. 8. Past experiences to body weight loss; Yes(69.5%), No(30.5%). The success rate accordant with the past temporary experiences shows that the cases without experience is higher than the ones with experience. 9. In distribution of times(treatments), 10 times is top. The rate of body weight loss is the highest in 14 times. Therefore, I think that one would need at least 10 times. in order lose body weight 10. Distribution of body weight variation in treatments times is at 2 times(3-4kg loss), and surprisingly is 14kg loss at above 15 times. 11. Distribution of symptoms improvement, in descending order ; heavy sense in body, dec. of appetite, inc.of exercise, lumbago, edema, knee pain, inc.of urine, inc. of fullness sense, thirsty, disease of gynecology, white tung, chest burning, heart burning, dec.of tobacco, drink taste. motion sickness, allergy, water eczema, arthma, belching. 12. Distribution of snack; Yes(87.4%), No(78.6%) 13. Distribution of exercise; Yes(21.4%), No(78.6%) 14. Distribution of sleeping times, above 7 hours(79.0%) 15. Distribution of the reason to body loss, the complex of beauty(68.7%) is top. 16. Distribution of side effect in obesity acupuncture, constipation (17.4%) is top. 17. Distribution of method in body weight loss ; dietary treatment (31.1%), sauna(26.7%), exercise(19.7%), the center of body weight loss (15.0%) herb-med and starvation treatments (5.1%), hand-finger acupuncture (hand-foot acupuncture) is 1.6%, diet pill(0.3%), etc(0.6%).

• Steel and Composite Structures
• /
• v.33 no.6
• /
• pp.891-906
• /
• 2019

This study considers the instability behavior of sandwich plates considering magnetorheological (MR) fluid core and piezoelectric reinforced facesheets. As facesheets at the top and bottom of structure have piezoelectric properties they are subjected to 3D electric field therefore they can be used as actuator and sensor, respectively and in order to control the vibration responses and loss factor of the structure a proportional-derivative (PD) controller is applied. Furthermore, Halpin-Tsai model is used to determine the material properties of facesheets which are reinforced by graphene platelets (GPLs). Moreover, because the core has magnetic property, it is exposed to magnetic field. In addition, Kelvin-Voigt theory is applied to calculate the structural damping of the piezoelectric layers. In order to consider environmental forces applied to structure, the visco-Pasternak model is assumed. In order to consider the mechanical behavior of structure, sinusoidal shear deformation theory (SSDT) is assumed and Hamilton's principle according to piezoelasticity theory is employed to calculate motion equations and these equations are solved based on differential cubature method (DCM) to obtain the vibration and modal loss factor of the structure subsequently. The effect of different factors such as GPLs distribution, dimensions of structure, electro-magnetic field, damping of structure, viscoelastic environment and boundary conditions of the structure on the vibration and loss factor of the system are considered. In order to indicate the accuracy of the obtained results, the results are validated with other published work. It is concluded from results that exposing magnetic field to the MR fluid core has positive effect on the behavior of the system.

• Journal of Environmental Science International
• /
• v.22 no.2
• /
• pp.225-234
• /
• 2013

The relationship between debris flow and topographical factors is essential for the reliable estimation of soil loss. The objective of this paper is to estimate stability index and soil loss for assessing landsliding risk caused by debris flow. SIMAP and RUSLE are used to estimate stability index and soil loss, respectively. The landsliding risk area estimated by using SIMAP is found to be different from the large land area estimated by RUSLE. It is found that the spatial distribution of soil cover significantly influences landsliding risk area. Results also indicate that stability index and soil loss, estimated by soil cover factor, improve the assessment of landsliding risk.

• Journal of Korean Society of Water and Wastewater
• /
• v.23 no.6
• /
• pp.871-879
• /
• 2009

The Korea has high population density, so the precipitation per capita is only one tenth to world average. The water resource in Korea is insufficient. But the leakage in the water distribution system is about 25%, and it is lower than other countries where water utilities are managed well. The pipelines' management also is getting worse because the leakage in the pipelines lower the ground density surrounding pipes. So, managing the leakage in the water distribution system is very important in the view of increasing the water resources and doing the efficient management of the pipeline system. Accordingly this study aimed to conduct a cause-analysis with scientific approaches considering key local factor related to water loss of distribution system and derive better performance indicators which are able to evaluate the real state of water loss management reasonably. Also this research aimed to develop a methodology capable of judging condition of infrastructure of water distribution system.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.3
• /
• pp.804-811
• /
• 2015

The presence of responsive loads in the promising active distribution networks (ADNs) would definitely affect the power system problems such as distributed generations (DGs) studies. Hence, an optimal procedure is proposed herein which takes into account the simultaneous placement of DGs and smart meters (SMs) in ADNs. SMs are taken into consideration for the sake of successful implementing of demand response programs (DRPs) such as direct load control (DLC) with end-side consumers. Seeking to power loss minimization, the optimization procedure is tackled with genetic algorithm (GA) and tested thoroughly on 69-bus distribution test system. Different scenarios including variations in the number of DG units, adaptive power factor (APF) mode for DGs to support reactive power, and individual or simultaneous placing of DGs and SMs have been established and interrogated in depth. The obtained results certify the considerable effect of DRPs and APF mode in determining the optimal size and site of DGs to be connected in ADN resulting to the lowest value of power losses as well.

• Journal of Information Technology Services
• /
• v.6 no.3
• /
• pp.163-177
• /
• 2007

This research is the concept of a game addiction absorbed in the game based on the review and analysis of factors that affect the characteristics of game addiction, it is appropriate to extract the purpose of factors. Game addiction factor is composed of a total of 32 questions, and a total of 356 people, to collect data through surveys. Factor analysis of the collected data to the target as a result of physical and mental problems, loss of control, tolerance, and avoidance of real world consists of three sub-factors. Factors that affect flow of tolerance and loss of control, and avoid the real world, including two sub-factors that could determine. Diagnostic game addiction factor in the reliability coefficients (Cronbach alpha) is a robust .966 aspects in the event. The game addiction scale score of 90-game addiction by category 'regular user', 90 points and 114 between the terms 'potentially dangerous user' and 13 percent of the overall. Finally, more than 115 points in the 'high-risk user' has been classified as 5% of the overall distribution of the notice that. Such factors extract game is a game addict, addicted users of the game and tend to properly evaluate and navigate game addiction-related problems early in the game addiction and found it could be used properly.