• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2292-2297
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• 2008

Recently, a study on condensers for refrigerators has focused on new model which will cost less and will be more efficient. Some widely used condensers for domestic refrigerators are wire-and-tube type condenser, hot-wall type condenser, and spiral type condenser. Some companies which use the spiral type condenser at the moment try to develop a new type condenser which will cost less and will be as efficient as the spiral type. The new type condenser consists of a steel tube, steel plates and louver fins attached to the tube. The tube and the plate are bent into a single-passage serpentine shape.

• Industrial Engineering and Management Systems
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• v.7 no.2
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• pp.113-125
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• 2008

This paper presents a model for designing cellular manufacturing systems (CMS) by integrating system cost, machine reliability, and preventive maintenance (PM) planning. In a CMS, a part is processed using alternative process routes, each consisting of a sequence of visits to machines. Thus, a level of 'system reliability' is associated with the machines along the process route assigned to a part type. Assuming machine reliabilities to follow the Weibull distribution, the model assigns the machines to cells, and selects, for each part type, a process route which maximizes the overall system reliability and minimizes the total costs of manufacturing operations, machine underutilization, and inter-cell material handling. The model also incorporates a reliability based PM plan and an algorithm to implement the plan. The algorithm determines effective PM intervals for the CMS machines based on a group maintenance policy and thus minimizes the maintenance costs subject to acceptable machine reliability thresholds. The model is a large mixed integer linear program, and is solved using LINGO. The results point out that integrating PM in the CMS design improves the overall system reliability markedly, and reduces the total costs significantly.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.267-270
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• 2001

A lot of efforts have been made to analyze the performance of the vehicle equipped with automatic transmission through simulation. It might be necessary to understand the different types of transmissions, i.e., different power flows, for different models. If there is a module that can be applied to different types of automatic transmission, it could be helpful to transmission-related engineers. This study has started up from this idea. The common bond graph has been obtained from several types of the automatic transmission. The overall generalized equations and kinematic constraint equations have been derived using virtual power sources on common bond graph. They are used to derive state equations and constraints. These equations have been applied as an application to the vehicle equipped with two simple planetary gear set type of Ravigneaux gear type automatic transmission. The state equation, kinematic constraints, and dynamic constraints have been derived in every gear and shift operation using overall generalized equations and kinematic constraint equations. Simulations for constraint speed running, standing-start running, rolling-start running, and LA-4 mode have been conducted to analyze the performance of the vehicle powertrain using GVPS(Generalized Vehicle Powertrain Simulation) program wit pull down menus.

• Journal of Magnetics
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• v.18 no.2
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• pp.207-211
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• 2013

In a coaxial magnetic gear, bridges connecting separate pole pieces are useful for fabrication and also improve mechanical reliability. However, they have a negative influence on electromagnetic performance parameters such as transmission torque and iron loss. This paper investigates the effect of stationary pole pieces connected by bridges on the electromechanical characteristics. The bridge type and thickness are the main parameters influencing the performance of a coaxial magnetic gear. The inner, center, and outer bridge types each show the best performance in terms of different characteristics. However, for any bridge type, an increase in the bridge thickness reduces the overall electromagnetic performance, except for the torque ripple, and improves the overall mechanical performance, including the deformation, von Mises stress, and natural frequency of the stationary part.

• KCI Concrete Journal
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• v.11 no.3
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• pp.141-151
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• 1999

In the replacement of bearing system of bridges, the jacking work to secure work spaces may cause damage of the superstructure, hence the behavior of superstructure by the jacking force must be considered. Especially, in prestressed concrete I-type girder bridges, considering the stress concentration at the girder and the load redistribution of superstructure, the allowable jacking force and jacking sequence have to be determined. In this study, an analytical method is proposed to calculate the jacking force and overall jacking sequence for the replacement of bearing system without any damage to the superstructure. The stress concentration at the girder and load redistribution of the deck due to jacking force are considered to compute the allowable jacking force for each girder and overall jacking sequence for girders in the deck. Using the solution algorithm developed in this study, the optimum jacking sequence and required jacking force for the prestressed concrete I-type gilder bridge having the standard sections are calculated.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.10 no.2
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• pp.202-216
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• 1998

A computer simulation for the performance analysis of automobile air conditioning components is carried out for the various operating conditions. The automobile air conditioning system consists of laminated type evaporator, swash plate type compressor, parallel flow type condenser, externally equalized thermostatic expansion valve and receiver drier. The overall heat transfer coefficient and the pressure drop in laminated type evaporator were obtained through experiments. In parallel flow type condenser, the performance analysis computer program using the empirical equation for heat transfer coefficient has been developed and the results are compared with experimental results. A model for matching the performance analysis programs of respective components .of automobile air conditioning system is introduced. Further, the effects of varying condenser size and refrigerant charge on the performance of automobile air conditioning system are discussed clearly.

• Journal of Korean Academy of Nursing
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• v.31 no.6
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• pp.1088-1097
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• 2001

This study was formed to propose a theoretical background trying to create a positive delivery experience by understanding college women's subjective accounts (their view and attitude) on delivery. Method: Q- methodology was used to appreciate the highly abstract concept in an objective manner, since delivery can be assessed differently with each experience. Result: There were three types of opinions about the delivery in college women. The first type (matured type) understood delivery to be a precious experience that enables women to gain the value of life through labor pain, and granted then more appreciation to their own mothers. The second type (will type) recognizes delivery as an option rather than an obligation for women. They think women chooses whether or not to experience the process, especially since delivery requires a great deal of responsibility. The third type (positive type) takes delivery as a valuable, worthwhile, and marvelous process that they wish to experience. They are not even afraid of giving birth multiple times. Conclusion: The study explains and allows us to understand college women's overall opinion and attitudes about delivery. Thus this study aids the seizure of an opportunity to build a theoretical base for delivery management.

• Journal of Family Resource Management and Policy Review
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• v.13 no.3
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• pp.281-305
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• 2009

The purpose of this study was to investigate the effect of use motivation type for mobile phones and the degree of loss perception related to mobile phone consumption consciousness in adolescents. The subjects of this study were 503 students in middle and high school in Daegu. A questionnaire was used for the survey. Factor analysis, cluster analysis, and MANOVA were employed for the data analysis and the $Scheff\acute{e}$ test was used for post-hoc analysis. The results are as follows: First, there are significant differences in mobile phone consumption consciousness in all sub-dimension areas according to use motivation type for mobile phone. Second, adolescents with high economic loss perception for mobile phones show high consumption consciousness in sub-dimension area, and adolescents with high academic loss perception show high relation-oriented consumption consciousness. Adolescents with high physical loss perception show high health-oriented, relation-oriented, and function-oriented consumption consciousness. Adolescents with high psychological loss perception, on the other hand, show high relation-oriented consumption consciousness. Third, there are significant differences in mobile phone consumption consciousness according to use motivation type for mobile phones and the degree of overall loss perception. However, there are no significant differences in the mobile phone consumption consciousness according to use motivation type for mobile phones and the degree of overall loss perception.

• The Journal of Advanced Prosthodontics
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• v.10 no.5
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• pp.388-394
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• 2018

PURPOSE. To measure axial displacement of different implant-abutment connection types and materials during screw tightening at the recommended torque by using a contact scanner for two-dimensional (2D) and three-dimensional (3D) analyses. MATERIALS AND METHODS. Twenty models of missing mandibular left second premolars were 3D-printed and implant fixtures were placed at the same position by using a surgical guide. External and internal fixtures were used. Three implant-abutment internal connection (INT) types and one implant-abutment external connection (EXT) type were prepared. Two of the INT types used titanium abutment and zirconia abutment; the other INT type was a customized abutment, fabricated by using a computer-controlled milling machine. The EXT type used titanium abutment. Screws were tightened at $10N{\cdot}cm$, simulating hand tightening, and then at the manufacturers' recommended torque ($30N{\cdot}cm$) 10 min later. Abutments and adjacent teeth were subsequently scanned with a contact scanner for 2D and 3D analyses using a 3D inspection software. RESULTS. Significant differences were observed in axial displacement according to the type of implant-abutment connection (P<.001). Vertical displacement of abutments was greater than overall displacement, and significant differences in vertical and overall displacement were observed among the four connection types (P<.05). CONCLUSION. Displacement according to connection type and material should be considered in choosing an implant abutment. When adjusting a prosthesis, tightening the screw at the manufacturers' recommended torque is advisable, rather than the level of hand tightening.

• Journal of the Korean Dietetic Association
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• v.13 no.3
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• pp.277-294
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• 2007

The purposes of this study were to a) examine using status, b) measure the service quality attributes, c) analyze IPA and customer satisfaction, d) develop the LSM(Local Store Marketing) by location of K theme restaurant such as residential type(A), complex type(B) and downtown type(C). The questionnaires were handed out to 346 of 450(usage rate 76.9%). The statistical data analysis was completed using SPSS(ver 12.0) for descriptive analysis, $X^2$, t-test, ANOVA, reliability analysis, factor analysis, multiple linear regression. From an analysis on service quality attributes, most importance of service quality attributes was more highly perceived than performance of those, except for 'attractive exterior', 'variety of kid's menu', 'convenient facilities for kid' and perceived importance and performance were also significantly different by location of branch restaurant. The attributes to be improved were 'convenience of restaurant's parking lot', 'food tast', 'speedy service' and 'service competency' as branch A(residential type) restaurant, 'convenience of the restaurant location' as branch B(complex type) restaurant and 'convenience of the restaurant location' and 'speedy service' as branch C(downtown type) through IPA analysis. The Overall customer satisfaction was 3.74 and service quality factors had significant effect on overall customer satisfaction. Location of restaurant, which gives a great effect on its operation and marketing, has a important correlation with success or failure of restaurant business enterprises. Therefore, marketing strategy by restaurant location should be developed.