• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.10
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• pp.1403-1407
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• 2013

This paper presents the method to calculate the motor parameters considering skew in EPS Interior Permanent Magnet Synchronous Motor (IPMSM). The skew is applied to stator or rotor by general technology used for design of reducing noise and vibration in motor. The characteristics analysis of motor including the skew is mostly used by 3D Finite Element Analysis (FEA), though, this analysis is a very time-consuming to perform. Besides, The reliability lacks due to the considerable change of motor characteristics according to the number of elements in 3D FEA. However, analysis time and effort can be saved by characteristic analysis considering skew using 2D FEA. Therefore, in this paper, a quick and accurate method for the calculations of motor parameters considering skew is suggested. The proposed method is verified by the comparison of calculated and experimental results.

• Journal of Environmental Science International
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• v.11 no.7
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• pp.669-677
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• 2002

This study was conducted to investigate the characteristics of role of transport on aerosol concentration at Crate Lake, Oregon USA for 1988.3~1999. 5. The IMPROVE program is a cooperative measurement effort governed by a steering committee composed of representatives from USA federal and regional-state organizations. Also IMPROVE sampler is designed to obtain a complete signature of the composition of the airborne particles affecting visibility. According to 10-day backward isentropic trajectory analysis, the frequency of local, marine and Asian trajectory showed 33.1%(335 cases), 47%(478 cases), 5.2%(53 cases) respectively. The monthly variation of nss $SO_4^{2-}$, nss S, $NO_3^-$, K and C showed the double peak pattern, high in April~May and August~september and showed the lowest concentration in Winter. The other constituents concentration except for Cl$^{[-10]}$ , Na, Mg was high in local trajectory than marine trajectory. A ratio nss $SO_4^{2-}$ to $SO_4^{2-}$ was 90.5% in marine trajectory and 98% in local trajectory. It suggest that the aerosol in Crater Lake was effected by salt. The annual mean concentration of nss $SO_4^{2-}$ and nss S decreased but the springtime concentration increased.

• Journal of the Korean Society of Mechanical Technology
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• v.20 no.6
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• pp.947-956
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• 2018

This research has been conducted to design upright parts of hand-made vehicles with the purpose of reducing material and machining cost while ensuring structural safety. Aluminum knuckles were modelled with three parts in order to enhance design flexibility as well as to reduce CNC machining cost. A vehicle model was constructed in CAD program and simulated in ADAMS View in order to estimate joint forces developing during 20 degree step steering condition at 60km/h. The joint forces obtained in the vehicle dynamics simulation were used for the structural analysis in ANSYS and dimensions of knuckle parts were adjusted until the lowest safety factor reached 2.0. The weight of knuckle decreased by 50% compared to the previous version that was designed without the structural analysis. The overall manufacturing cost decreased by 33% due to the reduction in the material as well as the CNC machining effort.

• Health Policy and Management
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• v.24 no.2
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• pp.136-142
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• 2014

Background: This study is to research on how hypertension control is associated with adherence in newly diagnosed hypertension patients. Methods: The study is based on 255,916 patients who were diagnosed with hypertension in 2009 and didn't have any previous medical history of hypertension or associated complication for the past year using data collected by National Health Insurance Corporation. Newly diagnosed hypertension patients are divided into two group by visiting medical center numbers (more than 300 days was adherence group, if not non-adherence group). Patients are considered to have successfully controlled their hypertension based on blood pressure measured by health examination. Chi-square test and logistic regression, repeated measured analysis of variance was used to analyze. Results: The relations between adherence and hypertension control show that 1.12 times of patients in adherence group was able to control their hypertension. The additional analysis proves that adherence group are more decreased level of blood pressure than non-adherence group except for patients who are over 70. Comparison of the average of systolic blood pressure and diastolic blood pressure between adherence and non-adherence groups shows that the blood pressure has been significantly among the adherence group. Conclusion: The study proves that constant treatment for hypertension could control the blood pressure and encourages patients to put more effort for persistent treatment. It also shows that hypertension treatment are more effective in younger patients than the elderly and strategies of approaching are different depending on age.

• Journal of the Korean Geographical Society
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• v.43 no.4
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• pp.511-525
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• 2008

Residential segregation is often considered to be one of the social problems that intensify urban inequality This study reviews three different frameworks about the causes of residential segregation and tests their validity in the real world. The review focuses on racial/ethnic residential segregation in U.S. cities since it has been blamed for persistent socio-economic gap among racial/ethnic groups. The three different segregation frameworks include 'spatial assimilation' that attributes segregation to low degree of assimilation and acculturation, 'place stratification' to discriminatory practices in the housing and mortgage markets such as steering, blockbusting, and redlining, and 'resurgent ethnicity' to racial/ethnic preference in residential choice, particularly in-group attraction. As an effort to test their validity, the paper examined residential pattern changes of the four major Asian nationality groups through 1990s and found that their residences got decentralized but re-cluster in some selected suburbs. This supports 'resurgent ethnicity' largely and 'spatial assimilation' only partly.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.11
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• pp.1429-1436
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• 2013

This study presents an approach for designing a vehicle rollover prevention controller using differential game theory and multi-level programming. The rollover prevention problem can be modeled as a non-cooperative zero-sum two-player differential game. A controller as an equilibrium solution of the differential game guarantees the worst-case performance against every possible steering input. To obtain an equilibrium solution to the differential game with a small amount of computational effort, a multi-level programming approach with a relaxation procedure is used. To cope with the loss of maneuverability caused by the active suspension, an electronic stability program (ESP) is adopted. Through simulations, the proposed method is shown to be effective in obtaining an equilibrium solution of the differential game.

• Health Policy and Management
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• v.25 no.2
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• pp.90-96
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• 2015

Background: This study aimed to research on how adherence and blood control could make a difference when it comes to develop complications. Methods: The study's subjects were 255,916 patients who were newly diagnosed with hypertension in 2009 using data collected by National Health Insurance Cooperation. Patients are considered as a group under adherence if visit days and prescription days are more than 300 days. Patients are considered to have successfully controled their hypertension based on actual value measured by National Health Insurance Cooperation and the study takes a look at whether they were diagnosed with complications of cerebrocardiovascular disease in 2012. Chi-square test and logistic regression was used to analyze. Results: Patients who were able to control their hypertension show 0.80 times chance of developing cerebrovascular disease, and 0.89 times chance of developing cardiocerebrovascular disease. The group of adherence shows lower chance of developing complication in general than the group of non-adherence. Conclusion: The study revealed that hypertension's constant treatment could control the blood pressure and prevent complications. It is important that encourages patients to effort for persistent treatment for reducing complication.