• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.3
• /
• pp.306-311
• /
• 2017

This paper deals with the design optimization of the kinematic characteristics of an automotive suspension system. The kinematic characteristics of the suspension determine the attitude of the wheels, such as the toe and camber, which not only relates to tire wear during driving, but also greatly affects the control of the vehicle and its stability, which corresponds to the motion performance of the vehicle. Therefore, it is very important to determine the characteristics of the suspension mechanism at the initial stage of the design. In this study, a displacement analysis is performed to determine the kinematic properties of the suspension for the McPherson strut suspension. For this purpose, a set of constraint equations for the joints constituting the suspension mechanism was established and a program was developed to solve them. We also used ADS, a design optimization program, to obtain the desired kinematic characteristics of the suspension. As the design variables for optimization, we used the coordinates of the hard points, which are the points of attachment of the suspension to the vehicle body, and are defined as the summation of the toe-in for the up and down movement of the wheel as the objective function. As the constraint functions, the maximum camber angle and minimum roll center height, which are design requirements, are considered. As a result of this study, it was possible to determine the optimal locations of the hard points that satisfy both constraint functions and minimize the change of the toe-in.

• KIISE Transactions on Computing Practices
• /
• v.23 no.6
• /
• pp.359-370
• /
• 2017

In overseas-hospital construction, the digital hospital is a trend that is based on the developments of the information and communication technologies, state-of-the-art medical equipment, smart health, and telemedicine. Along with the increasing proportion of IT, this has resulted in the spreading of the concept throughout city-like hospitals and their transformation into digital hospitals. In the hospital-construction business, IT is a key element that will link the modernization of the mechanical, electrical, and equipment systems, construction, and medical equipment for efficiency maximization through integration. The purpose of this study is the analysis of the market-expansion success factors through the construction of a success-story-based, IT-driven overseas-hospital business. The digital-hospital concept and the development process are analyzed through a literature review, and the success factors are analyzed in terms of the cost, time, and quality that are proposed in the project-management body of knowledge. The main contributions of this study regarding the success factors are as follows: First, a cost-side need exists regarding the establishment of strategic-value engineering in terms of increasing the value from the perspectives of the IT and operational infrastructures; second, in terms of the construction time, all of the hospital systems must comply with the established deadlines for the integrated test and commissioning; and lastly, in terms of quality, it is important to ensure that the System Integration digital-hospital services are delivered according to the user requirements.

• International Journal of High-Rise Buildings
• /
• v.1 no.1
• /
• pp.37-51
• /
• 2012

New generation of tall and complex buildings systems are now introduced that are reflective of the latest development in materials, design, sustainability, construction, and IT technologies. While the complexity in design is being overcome by the availability and advances in structural analysis tools and readily advanced software, the design of these buildings are still reliant on minimum code requirements that yet to be validated in full scale. The involvement of the author in the design and construction planning of Burj Khalifa since its inception until its completion prompted the author to conceptually develop an extensive survey and real-time structural health monitoring program to validate all the fundamental assumptions mad for the design and construction planning of the tower. The Burj Khalifa Project is the tallest structure ever built by man; the tower is 828 meters tall and comprises of 162 floors above grade and 3 basement levels. Early integration of aerodynamic shaping and wind engineering played a major role in the architectural massing and design of this multi-use tower, where mitigating and taming the dynamic wind effects was one of the most important design criteria established at the onset of the project design. Understanding the structural and foundation system behaviors of the tower are the key fundamental drivers for the development and execution of a state-of-the-art survey and structural health monitoring (SHM) programs. Therefore, the focus of this paper is to discuss the execution of the survey and real-time structural health monitoring programs to confirm the structural behavioral response of the tower during construction stage and during its service life; the monitoring programs included 1) monitoring the tower's foundation system, 2) monitoring the foundation settlement, 3) measuring the strains of the tower vertical elements, 4) measuring the wall and column vertical shortening due to elastic, shrinkage and creep effects, 5) measuring the lateral displacement of the tower under its own gravity loads (including asymmetrical effects) resulting from immediate elastic and long term creep effects, 6) measuring the building lateral movements and dynamic characteristic in real time during construction, 7) measuring the building displacements, accelerations, dynamic characteristics, and structural behavior in real time under building permanent conditions, 8) and monitoring the Pinnacle dynamic behavior and fatigue characteristics. This extensive SHM program has resulted in extensive insight into the structural response of the tower, allowed control the construction process, allowed for the evaluation of the structural response in effective and immediate manner and it allowed for immediate correlation between the measured and the predicted behavior. The survey and SHM programs developed for Burj Khalifa will with no doubt pioneer the use of new survey techniques and the execution of new SHM program concepts as part of the fundamental design of building structures. Moreover, this survey and SHM programs will be benchmarked as a model for the development of future generation of SHM programs for all critical and essential facilities, however, but with much improved devices and technologies, which are now being considered by the author for another tall and complex building development, that is presently under construction.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.8
• /
• pp.2484-2496
• /
• 2000

High speed switches have been developing to interconnect a large number of nodes. It is important to analyze the switch performance under various conditions to satisfy the requirements. Queueing analysis, in general, has the intrinsic problem of large state space dimension and complex computation. In fact, The petri net is a graphical and mathematical model. It is suitable for various applications, in particular, manufacturing systems. It can deal with parallelism, concurrence, deadlock avoidance, and asynchronism. Currently it has been applied to the performance of computer networks and protocol verifications. This paper presents a framework for modeling and analyzing ATM switch using stochastic activity networks (SANs). In this paper, we provide the ATM switch model using SANs to extend easily and an approximate analysis method to apply A TM switch models, which significantly reduce the complexity of the model solution. Cell arrival process in output-buffered Queueing A TM switch with finite buffer is modeled as Markov Modulated Poisson Process (MMPP), which is able to accurately represent real traffic and capture the characteristics of bursty traffic. We analyze the performance of the switch in terms of cell-loss ratio (CLR), mean Queue length and mean delay time. We show that the SAN model is very useful in A TM switch model in that the gates have the capability of implementing of scheduling algorithm.

• Journal of the Korean earth science society
• /
• v.26 no.7
• /
• pp.683-690
• /
• 2005

As remote sensing imagery with high spatial resolution (e.g. pixel resolution of 1m or less) is used widely in the specific application domains, the requirements of advanced methods for this imagery are increasing. Among many applicable methods, the texture image analysis, which was characterized by the spatial distribution of the gray levels in a neighborhood, can be regarded as one useful method. In the texture image, we compared and analyzed different results according to various directions, kernel sizes, and parameter types for the GLCM algorithm. Then, we studied spatial feature characteristics within each result image. In addition, a template matching program which can search spatial patterns using template images selected from original and texture images was also embodied and applied. Probabilities were examined on the basis of the results. These results would anticipate effective applications for detecting and analyzing specific shaped geological or other complex features using high spatial resolution imagery.

• Journal of the Korean Society for Library and Information Science
• /
• v.50 no.3
• /
• pp.215-247
• /
• 2016

This study was performed in order to derive components that librarians think preferentially necessary and realistically important when applying the NCS 'Library and Information Administration's duty' to the library working environments. It was possible by evaluating and analyzing the importance and utilization of ability unit and its element which are the components of NCS 'Library and Information Administration's duty'. First, ability units of 'User Information Services', 'Reading and Culture Programs' were higher in importance and utilization at the same time. Ability units of 'Library and Information Practical Research Perform', 'Library and Information Curation', 'Library and Information System Operation' were lower in importance and utilization when we evaluate the importance and utilization of ability unit and its element which are the components of NCS 'Library and Information Administration's duty'. Second, components of 'Reading and Culture Programs', 'User Information Service', 'Library and Information Collection' were higher in the order, and components of 'Library and Information Curation', 'Library and Information System Operation', 'Library and Information Practical Research Perform' were found lower in demands as the desirable level and the current level appear less common when we analyzed the demands on the duty components utilizing Borich requirements analysis model. Third, six ability units of 'Reading and Culture Programs', 'User Information Services', 'Library and Information Collection', 'Library and Information Services Marketing', 'Library and Information Preservation', 'Library and Information Use Analysis' were derived as priority components when we analyzed the priority of the duty component (ability unit) utilizing The Locus for Focus model.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.47 no.3
• /
• pp.22-30
• /
• 2010

This paper proposes a combination system of Adaptive Modulation and Coding (AMC) and Multiple Input Multiple Output (MIMO), which improves the throughput and has a better reliability. In addition, the system includes Precoding, Antenna Subset Selection and MIMO Mode Selection scheme. Finally, we make a performance analysis of the proposed system. The principal environmental parameters for the simulation experiment consist of a frequency non-selective rayleigh fading channel and a Spreading Factor (SF) of 16. Other parameters may be included in order to fulfill the requirements of the HSDP A Standard. The proposed system has a higher throughput and more reliability than the conventional system, which does not include MIMO Mode Selection scheme, Precoding or Antenna Subset Selection. According to the simulation results, the proposed system reaches the maximum throughput at 8dB, presentlng an improvement of 6dB and twice higher throughput, respect to the conventional system. Specifically, at the point of -6dB, the conventional system reaches 2.5Mbps, while the proposed system reaches 6.4Mbps at the same SNR. Also, at the point of 2dB, each system reaches 7.5Mbps (conventional system) and 15.3Mbps (proposed system), with near twice the difference. According to the results exposed above, we can conclude that the system proposed in this paper has, as the greatest contribution, the improvement of the throughput, especially, the average throughput.

• Journal of Trauma and Injury
• /
• v.19 no.1
• /
• pp.67-73
• /
• 2006

Purpose: The arterial base deficit (BD) has proven to be useful in the evaluation and management of trauma patients. Indicators such as the Triage-Revised Trauma Score (t-RTS) and the systemic inflammatory response syndrome (SIRS) score have been used as triage tools for emergency trauma patients in Korea. The purpose of this study was to assess the usefulness of the initial BD in predicting injury severity and outcome in the trauma population. Methods: The medical records of 308 consecutive trauma patients admitted to the Emergency Center of Masan Samsung Hospital from January 2004 to December 2004 were carefully examined prospectively and retrospectively, and 291 patients were selected as subjects for this research. The SIRS score and the t-RTS were calculated based on the records from the emergency department, and the BD was calculated based on the arterial blood gas analysis obtained within 30 minutes of admission. The efficiency of the three indicators as triage tools was evaluated by using cross tabulations in two - by - two matrices and by using a receiver operating characteristic (ROC) curve analysis. Results: When the mortality was used as the outcome parameter, the sensitivity and the accuracy of the initial BD were higher than those of the SIRS score (p<0.05) and were same as those of the t-RTS. The areas under the ROC curves of the initial BD, the SIRS score, and the t-RTS were $0.740{\pm}0.087$, $0.696{\pm}0.082$, and $0.871{\pm}0.072$, respectively (95% confidence interval). When emergency operation and blood transfusion requirements were used as outcome parameters, the comparisons of the sensitivities and the accuracies of the initial BD and the other two indicators showed the same pattern as mentioned above. The areas under the ROC curves of the initial BD were 0.7~0.8 and were larger than those of the SIRS score (p<0.05). Conclusion: The ability of the initial BD to predict injury severity and outcome was similar to those of the t-RTS and the SIRS score. Therefore, the authors suggest that the initial BD may be used as an alternative to previous triage tools for trauma patients.

• Journal of the Korean earth science society
• /
• v.26 no.6
• /
• pp.501-510
• /
• 2005

An analysis was done on the “inquiry sections” of Earth Science chapters of 10th grade science textbooks. The Inquiry sections were classified into different types and the frequencies of basic process skills, integrated process skills, and inquiry activities were measured in section to find out whether they sufficiently satisfy the requirements based on the 7th National Curriculum. The number of selected science textbooks that have been used in high school for this study were eleven. The number of inquiry tasks were on an average of 24.0. The types of inquiry sections and the elements of basic and integrated process skills were different in every textbooks. The number of inquiry activities were also different and analyzed more than those presented. They were not integrated activities but presented as scientific process skills. The basic process skills and integrated process skills presented in textbooks were $16\%\;and\;77.2\%$, respectively. However, the distribution of two kinds of process skills were analyzed to be $45.6\%\;and\;55.4\%$, respectively. In the process skills, the frequencies of inferring $(49.5\%)$ and data interpretation (68.7%) were the highest; however, the other process skills including recognizing problem, formulating hypothesis and generalization were not even presented in any of the text books. Due to the lack of the definitions of Science process skills and inquiry activities in the 7th National Curriculum, each text book defined these terms differently. It suggests that the meaning of inquiry, science process skills, and inquiry activities should be operationally defined in the national curriculum and the criteria for construction of inquiry activities are required.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.37 no.6
• /
• pp.761-768
• /
• 2013

New warheads are designed and developed to be highly lethal when used as part of ballistic missile payloads. There are many trades associated with the design of a central warhead core, mainly dealing with the projectiles or penetrators. Obviously, a payload-type configuration is very susceptible to kills from one projectile because of the high impacts required for bomblet or submunition payloads. Based on these requirements, the optimum kill vehicle configuration will have the smallest mass and relative velocity that will kill all the submunitions. The designs of the penetrator shape and size are directly related to the space and weight of the warhead. The shape, size, L/D, penetrator material, and manner in which they are inserted inside the surrounding explosive segments are critical in achieving successful penetrator design. The AUTODYN-3D code was used to study the effect of penetrator penetration. The objective of numerical analysis was to determine the penetration characteristics of the penetrator produced by hypervelocity impacts under different initial conditions such as initial velocity, shape, and L/D of the penetrator.