• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.263-266
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• 2001

The performance of the powertrain can be analyzed using dynamic models including transient characteristics, and the equations of motion can also be derived from the dynamic models of the powertrain. In this study, the shift transient characteristics of the vehicle equipped with Ravigneaux type planetary gears automatic transmission has been investigated.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.8
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• pp.709-714
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• 2001

Recently, most vehicles has the Automatic transmission system as their transmission system. The automatic transmission system operates with fixed shift patterns. In the opposite of manual operation, it is easy and convenient for driving. Though these merit, the system can not evaluate the driver s intension because of usage of fixed shift pattern. To consider driver s intension, we must consider both the driving intensity of driver and the status of vehicle. In this paper, we developed flexible automatic transmission system by using the proposed moduled neural networks which can learn the status of th vehicle and driver s intensity. As a results, we compare the transmission system using fixed shift pattern and the proposed transmission system and show the good performance in the change of shift position.

• Korean Journal of Occupational Health Nursing
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• v.18 no.1
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• pp.14-21
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• 2009

Purpose: This study was performed to investigate the effect of shift work on diurnal blood pressure (BP) pattern in nurses. Method: We studied 20 healthy nurses engaged in 3 shift work. 24-hour ambulatory BP monitoring was performed to each nurse two times during the day and night shift. Five nurses were excluded because of inadequate BP measurement. Results: All subjects were female. The mean age was 27.4 years (range: 23-33 years) and mean body mass index was 19.7 Kg/$m^2$ (range: 18.0-21.2 Kg/$m^2$). The changes of systolic BP ($17.8{\pm}9.1$ vs. $13.2{\pm}4.7%$, p=0.031), diastolic BP ($22.3{\pm}8.7$ vs. $17.3{\pm}9.0%$, p=0.061), and heart rate ($25.2{\pm}5.2$ vs. $12.5{\pm}8.7%$, p=0.001) during the sleeping period were decreased after a night shift compared with day shift. The non-dipper group significantly increased from 20% to 40% after a night shift (p=0.018). Conclusion: Working night shift is significantly associated with non-dipper status in nurses.

• Korean Journal of Occupational Health Nursing
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• v.17 no.1
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• pp.45-54
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• 2008

Purpose: This study was conducted to compare and estimate sleep patterns and health status of the shift and non-shift factory workers. Methods: The subjects of this study were 290 male workers in 13 companies, which manufacture automobile parts in Daegu, Korea. Survey data were collected from March 5th, 2007 to April 5th, 2007. PSQI was scored to check the quality of sleep, ESS for excessive daytime sleep disorder, ISI for insomnia, and SF-36 for health status. The data were analyzed by $X^2$ and t-test using SPSS 12.0 for windows. Results: There was a difference in quality of sleep patterns between shift and non-shift workers (p=.033). A difference in the pattern of excessive daytime sleep (P=.005) and in the degree of insomnia (p=.030) were observed between the two groups. However, there were no significant difference in health status between the two groups. Conclusion: Based on these results, shift workers are in need of careful and continuous monitoring regarding sleep disorders and we need to develop health promotion programs including sleep hygiene for shift workers.

• Journal of Mechanical Science and Technology
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• v.15 no.11
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• pp.1472-1481
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• 2001

In this paper, an advanced shift controller that supervises the shift transients with adaptive compensation is presented. Modern shift control systems for vehicle automatic transmission are designe d to provide smooth transients for passengers' comfort and better component durability. In the conventional methods, lots of testing and calibration works have been done to tune gains of the controller, but it does not assure optimum shift quality at all times owing to system variations often caused by uncertainties in shifting hydraulic systems and external disturbances. In the proposed control scheme, an adaptive compensation controller with intelligent supervisor is implemented to achieve improved shift quality over the system variations. The control input pattern which generates clutch pressure commands in hydraulic actuating systems, is updated through a learning process to adjust for each subsequent shift based on continuous monitoring of shifting performance and environmental changes. The proposed algorithm is implemented and evaluated on the experimental test setup. Results from the experimental studies for several operation modes show both improved performance and adaptability of the proposed shift controller to uncertain changes of the shifting environment in vehicle power transmission systems.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.5
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• pp.822-827
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• 2002

In general, jerk phenomenon appeared because of gear changing, when a vehicle starts off or climbs an incline. Therefore, it makes ride quality worse. In this paper, an optimal pattern of automatic transmission was designed using fuzzy logic in order to improve ride quality. After del eloping fuzzy rule for shift pattern control of automatic transmission, dynamic characteristics (i.e. acceleration, velocity, distance and so on) were simulated using dynamic model of a car. To do this he powertrain model of a vehicle with automatic transmission including torque converter, gear box, and final gear drive - from engine to tire - is developed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.409-412
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• 1996

In this paper, the response characteristics of organic gases were investigated by using quartz crystal microbalance(Q.C.M) with different polymeric sensitive materials. The new linear parameter was discussed in order to develope gas sensing system using neural network and pattern recognition. We analyzed the response characteristics by the area of resonant frequency shift of quartz crystal, which mean affinities of organic gases for polymeric sensitive firm. The experimental results shows that the parameter made by the area of frequency shift which was linear with injection amount of organic gases has possibility to be used for pattern recognition and neural network. And they have different normalized pattern.

• Korean Journal of Optics and Photonics
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• v.8 no.3
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• pp.241-244
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• 1997

A speckle pattern from an optical fiber is used for a reference beam in writing and reading a volume hologram. The photorefractive volume hologram with this scheme shows good spatial selectivity for spatial(shift) multiplexing because the speckle pattern in writing and reading a hologram looses correlation with a small spatial shift. This scheme has the insensitivity to axial movement. The data storage system with this scheme will have a high storage density and a good stability in operation. We theoretically analyze the diffracted beam from a volume hologram recorded with the speckle pattern from the optical fiber. Experimental results are presented and compared with numerical analysis.

• The KIPS Transactions:PartA
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• v.12A no.2 s.92
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• pp.87-94
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• 2005

Pattern matching is one of critical parts of Network Intrusion Prevention Systems (NIPS) and computationally intensive. To handle a large number of attack signature fattens increasing everyday, a network intrusion prevention system requires a multi pattern matching method that can meet the line speed of packet transfer. In this paper, we analyze Snort, a widely used open source network intrusion prevention/detection system, and its pattern matching characteristics. A multi pattern matching method for NIPS should efficiently handle a large number of patterns with a wide range of pattern lengths and case insensitive patterns matches. It should also be able to process multiple input characters in parallel. We propose a multi pattern matching hardware accelerator based on Shift-OR pattern matching algorithm. We evaluate the performance of the pattern matching accelerator under various assumptions. The performance evaluation shows that the pattern matching accelerator can be more than 80 times faster than the fastest software multi-pattern matching method used in Snort.

• Journal of Nutrition and Health
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• v.47 no.6
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• pp.416-425
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• 2014

Purpose: The purpose of this study was to investigate the stress, dietary habits, dietary behaviors, and health-related behavior of nurses. Method: The subjects of this study were 161 nurses studying at a cyber university. The general characteristics, stress, dietary habits, dietary behaviors, and health-related behavior of the subjects were surveyed using a self-administered questionnaire in October, 2010. The subjects were divided into two groups according to the working pattern: shift workers (n = 110) and non-shift workers (n = 51). Results: In the general characteristics, there were significant differences in marriage, monthly income, employment type, and job satisfaction between the two groups. Total stress score did not differ significantly between the two groups. In dietary habits, significant differences in meal regularity, skipping meals, skipping reasons, having regular mealtimes, frequency of snack and the snack time between shift workers and non-shift workers (p<0.05). Total score of dietary behaviors in shift workers was significantly lower than that in non-shift workers (p<0.05). Score of shift workers in taking three meals per day regularly was significantly lower than that of non-shift workers. In health-related behavior, a significant difference in sleeping time was observed between shift workers and non-shift workers. Dietary behavior showed negative correlation with shift work (r = 0.176) and positive correlation with health consciousness (r = 0.210) and perceived health status (r = 0.198) in subjects after adjustment for age, marriage, monthly income, and employment type (p < 0.05). Multiple regression analysis revealed that shift work, health consciousness, and perceived health status affected dietary behavior in subjects. Conclusion: These results indicate that shift working nurses had poor dietary habits and dietary behaviors, and these dietary behaviors are affected by their shift work, health consciousness, and perceive health status.