The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Dongkuk Chang - One of the best experts on this subject based on the ideXlab platform.
-
Social crime or spatial crime? exploring the effects of social, economical, and spatial Factors on burglary rates
Environment and Behavior, 2011Co-Authors: Dongkuk ChangAbstract:Space-crime research has primarily focused on crime prevention through environmental Design, based on the ideology of defensible space, territoriality, target-hardening Factors, and so on. Much of the research has attempted to determine ideological imperatives within the scope of either architectural buildings or urban areas. Few studies can be found dealing with whether there exists a significant influence of spatial configuration or CPTED-based building Designs or social and economical reasons for the patterns of residential burglary distribution. This research focuses on three major Factors: social Factor of building use patterns, economical Factor of building values, and two spatial Factors, namely, the configurational Factor of urban space structures and the Design Factor of architectural buildings. To examine the effect of the latter Factors on burglary distribution patterns, configurational Factor of urban space structures will be examined by investigating the configurational Factors of intelligibility and integration. Other Factors in consideration are road types, the types of buildings that witness high crime rates, and visibility issues. For the effect of building Design Factors, issues such as the number of entrances, building height, and target-hardening facilities will be examined. Our findings across six areas in a metropolitan city suggest that intelligible areas that can be easily accessible by passersby, and thus, enable more people to enter the area, are deemed to be less vulnerable than less intelligible areas. The urban space structure configures residential burglary patterns and building-use patterns significantly affect burglary rates, followed by road type and Design Factor issues.
Seok-jun Moon - One of the best experts on this subject based on the ideXlab platform.
-
Development of Hybrid Vibration Isolator by Inertial-Type Actuator and Wire Mesh Mount
IEEE ASME Transactions on Mechatronics, 2019Co-Authors: Yun-ho Shin, Byung Chang Jung, Seok-jun MoonAbstract:Hybrid-type mounts have been frequently developed as combining active vibration control techniques to preDesigned passive mounts in order to increase equipment precision and to provide sufficient performance in extreme environments. Among various passive vibration isolation materials, wire mesh is regarded as a good candidate for reducing vibration due to its moderate material price, ease of machining, and long life cycle, without significant deterioration induced by aging or environmental effects. However, research on Design, including wire mesh material, as a mount material, and the application of active control technology to its performance have rarely been conducted. In this paper, the method and procedure of an active hybrid mount Design using a wire mesh material and inertial mass type actuator are proposed. Prior to Designing a passive wire mesh isolator, the static and dynamic elastic modulus of wire mesh materials were experimentally extracted using simple shaped cylindrical specimens, and their characteristics relating to vibration isolator Design were examined. From the experimental results of the simple shape specimens, density was determined to be the most important Design Factor, and the procedure for Designing the passive component of the hybrid mount was proposed with density as the Design Factor. In addition, a procedure for Designing an inertial mass type active vibration reduction device using a piezo actuator is also proposed with the goal of vibration reduction in equipment with periodic operation frequency, such as motors and pumps, and the vibration reduction effectiveness of the hybrid mount system was examined by simple two- and three-degree-of-freedom systems.
Jeffrey H Lang - One of the best experts on this subject based on the ideXlab platform.
-
mechanical Design considerations for conventionally laminated high speed interior pm synchronous machine rotors
IEEE Transactions on Industry Applications, 2004Co-Authors: E C Lovelace, T M Jahns, T A Keim, Jeffrey H LangAbstract:This paper discusses mechanical Design considerations that are particular to conventionally (i.e., radially) laminated rotors of interior permanent-magnet synchronous machines. Focus is placed on applications where the radial forces due to high-speed operation are the major mechanically limiting Design Factor. Proper Design of the lamination bridges, or ribs, at the rotor outer diameter is explained in terms of the both material considerations and electromagnetic performance impact. The tradeoff of complexity versus performance associated with using strengthening ribs in the magnet cavities is discussed. The sensitivity of the mechanical Design limitations to the rotor-shaft mounting mechanism is also highlighted. These effects are then analyzed using finite-element analysis for a 150-N/spl middot/m/6-kW integrated starter/alternator Designed for operation up to 6000 r/min with an annular rotor to accommodate a torque converter or clutch assembly. This example demonstrates that it is possible to significantly improve the rotor's structural integrity using the techniques described in this paper with only a very modest impact on the projected machine drive cost.
-
Mechanical Design considerations for conventionally-laminated, high-speed, interior PM synchronous machine rotors
IEMDC 2001. IEEE International Electric Machines and Drives Conference (Cat. No.01EX485), 2001Co-Authors: E C Lovelace, T M Jahns, T A Keim, Jeffrey H LangAbstract:This paper discusses mechanical Design that are particular to conventionally (i.e., radially) laminated rotors of interior permanent-magnet synchronous machines. Focus is placed on applications where the radial forces due to high-speed operation are the major mechanically limiting Design Factor. Proper Design of the lamination bridges, or ribs, at the rotor outer diameter is explained in terms of the both material considerations and electromagnetic performance impact. The tradeoff of complexity versus performance associated with using strengthening ribs in the magnet cavities is discussed. The sensitivity of the mechanical Design limitations to the rotor-shaft mounting mechanism is also highlighted. These effects are then analyzed using finite element analysis for a 150 Nm/6 kW integrated starter/alternator Designed for operation up to 6000 RPM with an annular rotor to accommodate a torque converter or clutch assembly. This example demonstrates that it is possible to significantly improve the rotor's structural integrity using the techniques described in this paper with only a very modest impact on the projected machine drive cost.
Yun-ho Shin - One of the best experts on this subject based on the ideXlab platform.
-
Development of Hybrid Vibration Isolator by Inertial-Type Actuator and Wire Mesh Mount
IEEE ASME Transactions on Mechatronics, 2019Co-Authors: Yun-ho Shin, Byung Chang Jung, Seok-jun MoonAbstract:Hybrid-type mounts have been frequently developed as combining active vibration control techniques to preDesigned passive mounts in order to increase equipment precision and to provide sufficient performance in extreme environments. Among various passive vibration isolation materials, wire mesh is regarded as a good candidate for reducing vibration due to its moderate material price, ease of machining, and long life cycle, without significant deterioration induced by aging or environmental effects. However, research on Design, including wire mesh material, as a mount material, and the application of active control technology to its performance have rarely been conducted. In this paper, the method and procedure of an active hybrid mount Design using a wire mesh material and inertial mass type actuator are proposed. Prior to Designing a passive wire mesh isolator, the static and dynamic elastic modulus of wire mesh materials were experimentally extracted using simple shaped cylindrical specimens, and their characteristics relating to vibration isolator Design were examined. From the experimental results of the simple shape specimens, density was determined to be the most important Design Factor, and the procedure for Designing the passive component of the hybrid mount was proposed with density as the Design Factor. In addition, a procedure for Designing an inertial mass type active vibration reduction device using a piezo actuator is also proposed with the goal of vibration reduction in equipment with periodic operation frequency, such as motors and pumps, and the vibration reduction effectiveness of the hybrid mount system was examined by simple two- and three-degree-of-freedom systems.
M. Shiratori - One of the best experts on this subject based on the ideXlab platform.
-
Reliability Evaluation Method for Electronic Device BGA Package Considering the Interaction Between Design Factors
2020Co-Authors: S. Kondo, Q. Yu, T. Shibutani, M. ShiratoriAbstract:The recent development of electric and electronic devices has been remarkable. The miniaturization of electronic devices and high integration are progressing by advances in mounting technology. As a result, the reliability of fatigue life has been prioritized as an important concern, since the thermal expansion difference between a package and printed circuit board causes thermal fatigue. It is demanded a long-life product which has short development time. However, it is difficult because of interaction between each Design Factor. The authors have investigated the influence of various Design Factors on the reliability of soldered joints in BGA model by using response surface method and cluster analysis. By using these techniques, the interaction of all Design Factors was clarified. Based upon the analytical results, Design engineers can rate each Factor’s effect on reliability and assess the reliability of their basic Design plan at the concept Design stage.
-
New Reliability Assessment Method for Solder Joints in BGA Package by Considering the Interaction between Design Factors
2007Co-Authors: S. Kondo, Q. Yu, T. Shibutani, M. ShiratoriAbstract:As the integration and the miniaturization of electronics devices, Design space become narrower and interactions between Design Factors affect their reliability. This paper presents a methodology of quantifying the interaction of each Design Factor in electronics devices. Thermal fatigue reliability of BGA assembly was assessed with the consideration of the interaction between Design Factors. Sensitivity analysis shows the influence of each Design Factor to inelastic strain range of a solder joint characterizing the thermal fatigue life if no interaction occurs. However, there is the interaction in BGA assembly since inelastic strain range depends on not only a mismatch in CTE but also a warpage of components. Clustering can help engineers to clarify the relation between Design Factors. The variation in the influence was taken to quantify the interaction of each Design Factor. Based on the interaction, simple evaluating approach of inelastic strain range for the BGA assembly was also developed. BGA package was simplified into a homogeneous component and equivalent CTE wascalculated from the warpage of BGA and PCB. The estimated equation was derived by using the response surface method as a function of Design Factors. Based upon these analytical results, Design engineers can rate each Factor's effect on reliability and assess the reliability of their basic Design plan at the concept Design stage.
-
Easy reliability Design approach for solder joint BGA package considering correlation of each Design Factor
Thermal and Thermomechanical Proceedings 10th Intersociety Conference on Phenomena in Electronics Systems 2006. ITHERM 2006., 2006Co-Authors: Q. Yu, T. Shibutani, S. Kondo, M. ShiratoriAbstract:The recent development of electric and electronic devices has been remarkable. The miniaturization of electronic devices and high integration are progressing by advances in mounting technology. As a result, the reliability of fatigue life has been prioritized as an important concern, since the thermal expansion difference between a package and printed circuit board causes thermal fatigue. In addition, because the development time of the product is being intensified, shortening the development time and reducing the cost are important concerns. It is demanded a good quality product which has short development time. However, it is difficult to guarantee quality during the Design phase, because it is hard to know which Design Factors will prolong the fatigue life. The authors have investigated the influence of various Design Factors on the reliability of soldered joints in BGA model by using response surface method. However, it became clear that this sensitivity analysis was not enough for reliability Design because of the effect of Design Factor correlation. So, it is necessary that the correlations between Design Factors of BGA package should be clarified. In order to investigate correlations between Design Factors, the authors have proposed a new approach to emboss efficiently the each Design Factor by applying cluster analysis. By using this technique, the correlation structure of the all Design Factor was clarified. Based upon the analytical results, Design engineers can rate each Factor's effect on reliability and assess the reliability of their basic Design plan at the concept Design stage
