• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.8
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• pp.621-629
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• 2020

LRU layout is a complex problem that requires consideration of various criteria such as airworthiness, performance, maintainability and environmental requirements. As aircraft functions become more complex, the necessary equipment is increasing, and unmanned aerial vehicles are equipped with more equipment as a substitute for pilots. Due to the complexity of the problem, the increase in the number of equipment, and the limited development period, the placement of equipment is largely dependent on the engineer's insight and experience. For optimization, quantitative criteria are required for evaluation, but criteria such as safety, performance, and maintainability are difficult to quantitatively compare or have limitations. In this study, we consider the installation and maintenance of the equipment, simplify the deployment model to the traveling salesman problem, Optimization was performed using a genetic algorithm to minimize the weight of the connecting cable between the equipment. When the optimization results were compared with the global calculations, the same results were obtained with less time required, and the improvement was compared with the heuristic.

• Journal of Biomedical Engineering Research
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• v.16 no.4
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• pp.543-554
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• 1995

This paper describes the improvement of driving stability and the control system for INMEL-VII which is motorized manual wheelchair to satisfy requirements of the disabled The INMEL-VI was based on high maneuverability of the omnidirection drive and safety But the results of field tests about two years showed some problems to the disabled in daily life such as driving stability, Pm switching noise, and rotation of motor without driving command on negative slope. To solve the problems due to an increased DC motor power and applied to direct connection method in INMEL- VII. It improved the driving circuits and set switching frequency to 5KHz to eliminate the switching noise caused by PWM control of DC motor, As compare with the INMEL-VI, INMEL-VII is improved in driving stability by transfer the weight center to forward. The results of field testing proved the improvement of the driving stability and software algorithm It has been estimated to have a hlgh practical use for powered walking aids to the disabled's daily life.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.6
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• pp.85-92
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• 2010

Recently the earthquake occurrences in Korea are likely to increase. Therefore, the facilities such as bridges and tunnels under the unexpected earthquakes need to be enhanced. Especially most of the subways previously built before 1988 have not been seismically designed, so their seismic safety requirements are required to be inspected and/or reinforced. In this study, the seismic reinforcement using FRP-ductile material layered composites was proposed to reinforce for the subway columns. Material properties of FRP-ductile material layered composites were calculated by laboratory tests considering the laminated conditions of the composites. Numerical simulations were performed using the experimental results of the specimens and the calculated properties of the composites. Seismic performance varied according to the types of composites: ductile material, number of layers, fiber orientations.

• Journal of Korea Society of Industrial Information Systems
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• v.18 no.2
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• pp.1-12
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• 2013

Information Security System is implemented in software, hardware and FPGA device. Implementation of S/W provides high flexibility about various information security algorithm, but it has very vulnerable aspect of speed, power, safety, and performing ASIC is really excellent aspect of speed and power but don't support various security platform because of feature's realization. To improve conflict of these problems, implementation of recent FPGA device is really performed. The goal of this thesis is to design and develop a FPGA hardware accelerator for information security system. It performs as AES, SHA-256 and ECC and is controlled by the Integrated Interface. Furthermore, since the proposed Security Information System can satisfy various requirements and some constraints, it can be applied to numerous information security applications from low-cost applications and high-speed communication systems.

• Korean Journal of Construction Engineering and Management
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• v.8 no.6
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• pp.246-262
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• 2007

The performance of projects has always been an area of interest in the construction industry. Roles of all construction supply chain partners are necessary; however the role of a contractor firm in the construction project is pivotal. So, this research intended to explore a Construction Firm's performance criteria which could measure the level of performance of that firm in an ongoing project. Data was collected from construction professionals working in three principal project participant organizations, namely Owner, Consultant and Contractor. A total of 113 nos. of performance measuring items were sorted from literature review and used to collect data. Statistical tools processed by SPSS program was employed to analyze the data. Out of total 113 items, only 65 nos. of variables were found to be acceptable to every population group of this study. Factor analysis revealed 12 key performance predicting factors (KPPF) with 53 predictive indicators. 12 KPPFS with index weight are: work progress and smoothening (9.3%), change order management and work accuracy (9.1%), business relationship building (8.1%), adequacy of construction work procedure (8.6%), quality performance (8.0%), health and site safety adequacy (8.8%), Innovative contractor (8.0%), adequacy of construction site information (6.8%), compliance with contract plan/specification requirements (8.9%), creditworthiness and financial capability (8.3%), intra-agency relationship and responsiveness (7.0%) and resource management (9.2%). These results could be useful to project management body to evaluate performance of its contractor firm on site as well as the contractor itself to assess own performance and its subcontractors on-site.

• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.3
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• pp.18-25
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• 2006

In order to perform system requirements quickly and accurately, an automatic design program of solid rocket motors(SRM) structure designated as the 'ProDes software' has been developed and verified. from given system design criteria and constraints, it has the capabilities to design, analysis, simulation and drawing process to greatly reduce the over 'design cycle time' and manpower of a project. The conception of the program is modular, and calculations are performed step by step allowing parametric design studies and providing final selected design goal. Each configurations of SRM components and joint types composed of various master models is obtained from the data base module of the library. Between the design results of the ProDes software and those of the previous detail design of the established motor showed good agreements.

• Structural Engineering and Mechanics
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• v.37 no.2
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• pp.233-251
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• 2011

The seismic provisions of the current edition (2005) of the National Building Code of Canada (NBCC) differ significantly from the earlier edition. The current seismic provisions are based on the uniform hazard spectra corresponding to 2% probability of exceedance in 50 years, as opposed to the seismic hazard level with 10% probablity of exeedance in 50 years used in the earlier edition. Moreover, the current code is presented in an objective-based format where the design is performed based on an acceptable solution. In the light of these changes, an assessment of the expected performance of the buildings designed according to the requirements of the current edition of NBCC would be very useful. In this paper, the seismic performance of a set of six, twelve, and eighteen story buildings of regular geometry and with concrete moment resisting frames, designed for Vancouver western Canada, has been evaluated. Although the effects of non-structural elements are not considered in the design, the non-structural elements connected to the lateral load resisting systems affect the seismic performance of a building. To simulate the non-structural elements, infill panels are included in some frame models. Spectrum compatible artificial ground motion records and scaled actual accelerograms have been used for evaluating the dynamic response. The performance has been evaluated for each building under various levels of seismic hazard with different probabilities of exceedance. From the study it has been observed that, although all the buildings achieved the life-safety performance as assumed in the design provisions of the building code, their performance characteristics are found to be non-uniform.

• Journal of the Society of Naval Architects of Korea
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• v.40 no.6
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• pp.20-29
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• 2003

When Arctic offshore development in the 1970's first led to the consideration of ice capable tankers, there was a high level of uncertainty over design requirements for both safety and ship performance. Also here was a lack of reliable methods to evaluate design proposals. Since that time, improved understanding of the ice environment has raised the confidence of design specifications. Parallel developments have resulted in a suite of engineering tools for ship performance evaluation at the design stage Recent development of offshore and near shore oil and gas reserves in several countries together with economic studies of increased transportation through the Russian Arctic has newly introduced the interest in ice capable tanker design. in response, Samsung Heavy Industries (SHI) applied its experience in tanker design and construction to the design of a specialized tanker with ice capability. SHI produced two prototype hull designs for further study. The performance of both hulls and of the propellers was evaluated at the Institute for Marine Dynamics (IMD) in St. John's, Newfoundland This paper discusses the development of the design, describes the model experiments to determine performance and variations, and presents the results.

• Korean journal of food and cookery science
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• v.33 no.3
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• pp.300-306
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• 2017

Purpose: This study aimed to prepare sea tangle vinegar and test its applicability as a vinegar-based functional salad dressing in terms of physicochemical properties. Methods: Sea tangle vinegar was prepared by mixing sea tangle with sugar and vinegar and fermenting the mixture at room temperature for 3 months. The resulting sea tangle vinegar was examined for its physicochemical properties and antioxidant activity with brewed vinegar and persimmon vinegar as controls. Results: The sea tangle vinegar showed significantly higher viscosity than control vinegars, and shear thinning behavior that is typical for salad dressing containing polymers. In addition, storage modulus (G′) of sea tangle vinegar was relatively high in dynamic viscosity measurement while that of control vinegars remained negligible. Together with the high soluble solids content of sea tangle vinegar, rheological behavior indicates that sea tangle vinegar had soluble polysaccharides extracted from sea tangle, consequently leading to an increase in viscosity. Titratable acidity (TA) and pH were 2.52% and 3.58, respectively, which satisfies the TA and pH requirements for microbiological safety of a salad dressing. Absorbance at 285 nm and Folin Ciocalteu's reagent method revealed that sea tangle vinegar contained antioxidative phenolic compounds. Conclusion: This study demonstrates that sea tangle vinegar could be potentially developed as a vinegar-based functional salad dressing when combined with sensory evaluation in the future.

• Fire Science and Engineering
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• v.25 no.6
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• pp.120-126
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• 2011

Recently luminous egress guide-lines are introduced for the fire safety of residents in the multi-use buildings such as Gosiwon. Little literature, however, on the quantitative and qualitative estimation for the egress performance of the luminous egress guide-lines can be found. This study carried out experimental investigations to evaluate the egress performance of the existing egress guide-lights and new luminous egress guide-lines. The results showed that both luminous egress guide-lines and egress guide-light satisfied the basic performance of KFI requirements. Under the 7 % smoke transmittance, however, luminous egress guide-lines showed 3 times longer visibility and less evacuation time than egress guide-lights. The evacuation density and smoke transmittance have significant effect on the evacuation time increase without the luminous egress guide-lines, however little effect with the installation.