• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.5
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• pp.109-126
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• 2017

Universal soil loss equation (USLE) is used to estimate soil loss solely or employed in any hydrologic models. Since soil erosion has been an issue in South Korea for decades, the Ministry of Environment enacted a law to regulate soil erosion in 2012, which is the Notification of topsoil erosion status. The notification is composed of preliminary and field investigations, the preliminary investigation suggests to use USLE and provides USLE factors. However, the USLE factors provided in the notification was prepared at least 10 years ago, therefore it is limited to reflect recent climate changes. Moreover the current yearly USLE approach does not provide an opportunity to consider seasonal variation of soil erosion in South Korea. A GIS-based model was therefore applied to evaluate the yearly USLE approach in the notification. The GIS-based model employs USLE to estimate soil loss, providing an opportunity to estimate monthly soil loss with monthly USLE factor databases. Soil loss was compared in five watersheds, which were Geumgang, Hangang, Nakdonggang, Seomjingang, and Yeongsangang watersheds. The minimum difference was found at Seomjingang watershed, the yearly potential soil loss were 40.15 Mg/ha/yr by the notification approach and 34.42 Mg/ha/yr by the GIS-based model using monthly approach. And, the maximum difference was found at Nakdonggang watershed, the yearly potential soil loss were 27.01 Mg/ha/yr by the notification approach and 10.67 Mg/ha/yr by the GIS-based model using monthly approach. As a part of the study result, it was found that the potential soil loss can be overestimated in the notification approach.

• Nuclear Engineering and Technology
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• v.50 no.4
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• pp.589-598
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• 2018

To maintain safety and reliability of reactors, redundant sensors are usually used to measure critical variables and estimate their averaged time-dependency. Nonhealthy sensors can badly influence the estimation result of the process variable. Since online condition monitoring was introduced, the online cross-calibration method has been widely used to detect any anomaly of sensor readings among the redundant group. The cross-calibration method has four main averaging techniques: simple averaging, band averaging, weighted averaging, and parity space averaging (PSA). PSA is used to weigh redundant signals based on their error bounds and their band consistency. Using the consistency weighting factor (C), PSA assigns more weight to consistent signals that have shared bands, based on how many bands they share, and gives inconsistent signals of very low weight. In this article, three approaches are introduced for improving the PSA technique: the first is to add another consistency factor, so called trend consistency (TC), to include a consideration of the preserving of any characteristic edge that reflects the behavior of equipment/component measured by the process parameter; the second approach proposes replacing the error bound/accuracy based weighting factor ($W^a$) with a weighting factor based on the Euclidean distance ($W^d$), and the third approach proposes applying $W^d$, TC, and C, all together. Cold neutron source data sets of four redundant hydrogen pressure transmitters from a research reactor were used to perform the validation and verification. Results showed that the second and third modified approaches lead to reasonable improvement of the PSA technique. All approaches implemented in this study were similar in that they have the capability to (1) identify and isolate a drifted sensor that should undergo calibration, (2) identify a faulty sensor/s due to long and continuous missing data range, and (3) identify a healthy sensor.

• Nuclear Engineering and Technology
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• v.48 no.2
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• pp.339-350
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• 2016

Based on the resonance integral (RI) tables produced by the NJOY program, the conventional subgroup method usually ignores both the resonance elastic scattering and the resonance interference effects. In this paper, on one hand, to correct the resonance elastic scattering effect, RI tables are regenerated by using the Monte Carlo code, OpenMC, which employs the Doppler broadening rejection correction method for the resonance elastic scattering. On the other hand, a fast resonance interference factor method is proposed to efficiently handle the resonance interference effect. Encouraging conclusions have been indicated by the numerical results. (1) For a hot full power pressurized water reactor fuel pin-cell, an error of about +200 percent mille could be introduced by neglecting the resonance elastic scattering effect. By contrast, the approach employed in this paper can eliminate the error. (2) The fast resonance interference factor method possesses higher precision and higher efficiency than the conventional Bondarenko iteration method. Correspondingly, if the fast resonance interference factor method proposed in this paper is employed, the $k_{inf}$ can be improved by ~100 percent mille with a speedup of about 4.56.

• Tunnel and Underground Space
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• v.24 no.4
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• pp.289-296
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• 2014

A simple analytical approach for stability assessment of underground storage caverns against ground uplift of overburden rock above the rock caverns for high pressurized fluid such as compressed air energy storage (CAES) and compressed natural gas (CNG) was developed. In the developed approach, we assumed that failure plane of the overburden is straight upward to ground surface, and factor of safety can be calculated from a limit equilibrium analysis in terms of this cylindrical shape failure model. The frictional resisting force on the failure plane was estimated by Hoek-Brown strength criterion which replaces with Mohr-Coulomb criterion such that both intact rock strength and rock mass conditions can be considered in the current approach. We carried out a parametric sensitivity analysis of strength parameters under various rock mass conditions and demonstrated that the factor of safety againt ground uplift was more sensitive to Mohr-Coulomb strength criterion rather than Hoek-Brown criterion.

• Archives of Plastic Surgery
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• v.33 no.4
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• pp.465-468
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• 2006

Purpose: Subciliary approaches to orbitozygomatic fractures have high incidence of complications such as scleral show and ectropion. Abnormal rearrangement of eyelid flaps may be a very important factor to induce abnormal cicatrical and consequent contracture. To prevent this problem, we used temporary lower eyelid suspension. Methods: A total of two hundred five patients were investigated for lower eyelid complication of orbitozygomatic fractures that underwent reconstruction with subciliary approach. The lower eyelid margin was pulled up toward the forehead using lower eyelid suspension suture to stretch the lower lid flaps. The lid suspension was maintained for one day after surgery. Results: The complications of the lower eyelid were in 15 cases(7.3%); seven cases(3.4%) of visible depressed scar, three cases(1.4%) of scleral show, two cases(1%) of ectropion, two cases(1%) of conjunctival swelling and one case(0.5%) of hematoma. Conclusions: The lower eyelid suspension seems to allow adhering lid flap in proper anatomical position and in the status of the maximal stretch and consequently preventing the severe complications such as scleral show and ectropion caused by scar contraction after subciliary approach.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.2
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• pp.220-227
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• 2001

The fatigue crack initiation life is studied on automotive tensile-shear spot weldment made from cold rolled carbon steel(SPC) sheet by using DCPDM and local strain approach. It can be found that the fatigue crack initiation behavior in spot weldment can be definitely detected by DCPDM system. To predict the fatigue life of spot weldment, the local stresses and strains at the potential critical region are estimated by approximate method based on Neubers rule and elastic-plastic FEM analysis. A satisfactory correlation between the predicted life obtained from Local strain approach based on Neubers rule and experimental life can be found in spot weldment within a factor of 2.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.7
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• pp.1050-1060
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• 2009

This study develops a scale for consumer clothing satisfaction based on Lee et al. 's (2002) five stages of the consumer life cycle (acquisition, possession, consumption, maintenance, and disposal). Data were gathered by surveying college students using convenience sampling, and 419 questionnaires were used in the statistical analysis. In analyzing the data, an exploratory factor analysis and a confirmatory factor analysis using a structural equation modeling were conducted. The proposed scale, which identified various sources of satisfaction and dissatisfaction associated with the 5 consumption cycles of clothing, suggests some guidelines for marketers in enhancing consumer clothing satisfaction across consumption stages. The model test for the scale also identified that consumption satisfaction had the greatest effect on consumer clothing satisfaction showing the strongest loading and squared multiple correlation.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.308-311
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• 2004

A novel single-stage power factor corrected (PFC) drive for switched reluctance motor (SRM) is presented to achieve sinusoidal, near unity power factor input current. The proposed PFC SRM drive has no additional active switch. And a single-stage approach, which combines a DC link capacitor used as do source and a drive used for driving the motor into one power stage, has a simple structure and low cost. The characteristics and validity of the proposed circuit will be discussed in depth through the experimental results.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.8 no.2
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• pp.87-93
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• 2008

In this paper, we propose a hierarchical fuzzy based nutrition evaluation system that can analyze the individuals' nutrition status through the inference results generated by each layer. Moreover, a method to minimize the uncertainty of inference in the evaluated nutrition status is discussed. To show the effect of the uncertainty in fuzzy inference, we compared the results of nutrition evaluation with/without the certainty factor of rules on 132 people over the age of 65. From the experimental results, we can see that the evaluation method with the modified certainty factor provides better reliability than that of the general evaluation method without the certainty factor.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.364-366
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• 2012

Quantification of acoustic amplification in a model chamber has been studied for combustion stabilization induced by passive control devices. DMD(Dynamic mode Decomposition) method is adopted and the results from method are compared with those from damping factor approach. The model chamber has a faceplate with baffled injectors, where damping factor has its maximum at a specific baffle gap. They show a good agreement with the results from the previous method.