• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.7
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• pp.1038-1044
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• 2013

A research on thermal analysis method is conducted for the characterization of heat generation during operation of Interior Permanent Magnet Synchronous Motor(IPMSM) for Light Railway Transits(LRT) in this paper. Efficient cooling of the heat generated in the IPMSM is important because the excessive heat generated from the winding, core and permanent magnet makes it harder for a long time continuous operation of IPMSM. Therefore, in order to analyze the heat generation characteristics of the 110kW-class IPMSM as advanced research for application the IPMSM to the cooling device, the heat transfer coefficients for each component of the 110 kW-class IPMSM were derived and the thermal equivalent network was configured to perform the thermal analysis in this study. Finally, the 110kW-class IPMSM prototype is made and a comparative verification between the test data and the thermal analysis results through its various performance tests are carried out.

• Journal of Korea Multimedia Society
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• v.14 no.1
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• pp.85-93
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• 2011

Previous existing vocabulary recognition programs calculate general vector values from a database, so they can not process phonemes that form during a search. And because they can not create a model for phoneme data, the accuracy of the Gaussian model can not secure. Therefore, in this paper, we recommend use of the Bhattacharyya distance measurement method based on the features of the phoneme-thus allowing us to improve the recognition rate by picking up accurate phonemes and minimizing recognition of similar and erroneous phonemes. We test the Gaussian model optimization through share continuous probability distribution, and we confirm the heighten recognition rate. The Bhattacharyya distance measurement method suggest in this paper reflect an average 1.9% improvement in performance compare to previous methods, and it has average 2.9% improvement based on reliability in recognition rate.

• Journal of the Korean Operations Research and Management Science Society
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• v.32 no.1
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• pp.77-91
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• 2007

In this paper, we present a symbiotic evolutionary algorithm for multi-objective optimization. The goal in multi-objective evolutionary algorithms (MOEAs) is to find a set of well-distributed solutions close to the true Pareto optimal solutions. Most of the existing MOEAs operate one population that consists of individuals representing the entire solution to the problem. The proposed algorithm has a two-leveled structure. The structure is intended to improve the capability of searching diverse and food solutions. At the lower level there exist several populations, each of which represents a partial solution to the entire problem, and at the upper level there is one population whose individuals represent the entire solutions to the problem. The parallel search with partial solutions at the lower level and the Integrated search with entire solutions at the upper level are carried out simultaneously. The performance of the proposed algorithm is compared with those of the existing algorithms in terms of convergence and diversity. The optimization problems with continuous variables and discrete variables are used as test-bed problems. The experimental results confirm the effectiveness of the proposed algorithm.

• Journal of Korean Academy of Nursing Administration
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• v.21 no.1
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• pp.88-98
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• 2015

Purpose: To evaluate the relationship between organizational socialization and intention to leave, and to identify factors affecting on intention to leave in operating room nurses. Methods: This study used a descriptive design. Seventy operating room nurses recruited from three hospitals under the same management style, in-service educational system, and working conditions agreed to participate in this study, and completed self-administered questionnaires of the organizational socialization and the intention to leave questionnaire. Respondents were classified by career as advanced beginner, competent practitioner, proficient practitioner and expert practitioner by Benner's stages of nursing proficiency. Data were analyzed with t-test, ANOVA with multiple comparisons, Spearman correlation, and multiple regression analysis. Results: Nurses unsatisfied with the current in-service continuous education had lower organizational socialization and higher intention to leave. In advanced beginners, job performance was lowest and organizational commitment was highest. In expert practitioners, intention to leave was highest. Organizational commitment, interpersonal relationship, identity and burnout were associated with intention to leave. Mutual trust, burnout, and interpersonal relationship were predictors of intention to leave explained 20.8% of variance. Conclusion: The career ladder program to enhance nurses' organizational socialization and intention to stay should be established and expanded for well-experienced operating room nurses.

• International Journal of Quality Innovation
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• v.1 no.1
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• pp.89-96
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• 2000

Evolutionary operation (EVOP) is a continuous improvement system which explores a region of process operating conditions by deliberately creating some systematic changes to the process variable levels without jeopardizing the product. It is aimed at securing a satisfactory operating condition in full-scale manufacturing processes, which is generally different from that obtained in laboratory or pilot plant experiments. Information on how to improve the process is generated from a simple experimental design. Traditional EVOP procedures are established on the assumption that the variance of the response variable should be small and stable in the region of the process operation. However, it is often the case that process noises have an influence on the stability of the process. This process instability is due to many factors such as raw materials, ambient temperature, and equipment wear. Therefore, process variables should be optimized continuously not only to meet the target value but also to keep the variance of the response variables as low as possible. We propose a scheme to achieve robust process improvement. As a process performance measure, we adopted the mean square error (MSE) of the replicate response values on a specific operating condition, and used the Kruskal-Wallis test to identify significant differences between the process operating conditions.

• Transactions of the Korean hydrogen and new energy society
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• v.15 no.3
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• pp.208-219
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• 2004

To find a suitable oxygen carrier particle for a 50kW chemical-looping combustor, which was designed and installed to demonstrate continuous oxidation and reduction, three oxygen carrier particles(NiO/bentonite, $NiO/NiAl_2O_4$, $CoO_x/CoAl_2O_4$) were prepared. The reactivity and the attrition resistance of particles were measured and investigated by a thermo-gravimetrical analyzer and an attrition test apparatus respectively. From the viewpoints of oxygen transfer capacity, optimum reaction temperature(operating temperature range), reaction rate, carbon deposition rate, and attrition resistance, NiO/bentonite particle showed better performance than the other particles, therefore we selected NiO/bentonite particle as an optimum oxygen carrier particle.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.244-246
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• 2004

Compared with other transport means, safety and timeliness are the merits of railways. Unexpectedly when accident happens, much time and human strength are required to cope with the accident. And for swift recovery, systematic rehabilitation is needed. Recently using MTS(Moving picture Transmission System), we can perform accident rehabilitation and recording work efficiently. MTS is the device that transmits continuous picture information from accident field to control center. We are developing the appropriate system to railway situation to make use of the existing information communication technology, processing technology of video-tex, super high speed transmission technology through fiber-optic, copper cable and network description of information Technology, etc. If these communication-based can technologies are applied to railway system, railway managers can control the accident by inspecting the picture of accident field and can contribute to the safe train operation and the improvement of railway management. In this paper, we investigate the connecting methods when optical fiber is used for moving picture data transmission of train accidents, and its problems. And, we validate MTS's performance through about 28km section of field test.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.679-680
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• 2008

Most of the small wind turbines are set as the stand alone type in the area where the access to the grid is difficult and compulsorily uses the battery. Depending on the volume of the battery, securing of the space necessary, and has the shortcoming of replacing the battery periodically due to it's limited working life span. Recently, setting up in the vicinity of the city area is increasing and the trend of using the Grid inverter instead of battery is also increasing. This thesis is aiming mainly analyzing the characteristics of the output power of the Prototype Permanent Magnet Generator(PMG) and the Grid-Inverter and to verify through the theoretical study and tests. Tested the characteristics of the output power of the PMG through the stage 1-2 and at the stage 3 connected the output of the PMG to the Inverter and tested the characteristics of the Inverter. And at the stage 4, the maximum output power is confirmed by the continuous running test of the PMG.

• Journal of Korean Society of Transportation
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• v.27 no.6
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• pp.157-166
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• 2009

A network design problem (NDP) is to find a design parameter to optimize the performance of transportation system. This paper presents a modified NDP, called target-oriented NDP, which contains a target that we try to arrive in real world, and also proposes a solution algorithm. Unlike general NDP which seeks an optimal value to minimize or to maximize objective function of the system, in target-oriented NDP traffic manager or operator can set a target level prior and then try to find an optimal design variable to attain this goal. A simple example for mode choice problem is given to test the model.

• Agricultural and Biosystems Engineering
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• v.5 no.2
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• pp.40-44
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• 2004

This study was conducted to solve the problem of spinach harvesting done by manpower at the outdoor field during the cold winter season. Prototype spinach harvester was designed to dig, pick-up, and collect in a continuous operation for harvesting outdoor field-planted crawling type spinach. In the field test, two types of blades (Type A : angle of $150^{\circ}$, Type B : straight) were used for measuring the cutting loads of spinach and chain conveyor with lugs was used for picking up the root cut spinach. Prototype's vibrating blade reduced the digging power of the fixed blade by $46\%$. The loss was also very little ($0.7\%$) with a digging depth of 4 cm, an oscillation frequency of 748 rpm, and an oscillation distance of 33 mm. The working performance of the prototype spinach harvester was 38 hour/ha resulting to $96\%$ labor cost reduction compared to the conventional harvesting.