• Journal of Hydrogen and New Energy
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• v.26 no.3
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• pp.294-299
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• 2015

Free piston linear engine (FPLE) is a promising concept being explored in the mid-20th century. On the other hand, Arficial neural networks (ANNs) are non-linear computer algorithms and can model the behavior of complicated non-linear processes. Some researchers already studied this method to predict internal combustion engine characteristics. However, no investigation to predict the performance of a FPLE using ANN approach appears to have been published in the literature to date. In this study, the ability of an artificial neural network model, using a back propagation learning algorithm has been used to predict the in-cylinder pressure, frequency, maximum stroke length of a free piston linear engine. It is advised that, well-trained neural network models can provide fast and consistent results, making it an easy-to-use tool in preliminary studies for such thermal engineering problems.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.3
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• pp.69-79
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• 1999

Recently, new concept and paradigm of 'Environmentally-Friendless' is taking a growing interest in environmental planning and design. This study is to develop the new approach of sustainable development, and to establish the indicators for environmentally-friendliness of "Tourism Farms" in rural areas. A questionnaire survey was conducted for deputy manager group and expert group. The environmentally-friendliness of tourism farms is composed of three categories, conservation of global environment(Low Impact), friendliness to surrounding nature(High Contact), and environmental health and amenities (Health '||'&'||' Amenity). Four indicators, such as saving of energy and water resource, reduction and reuse of garbage, natural purification of sewage disposal, and utilization of natural energy, were affecting the first category, i.e., conservation of global environment(Low Impact). And, friendliness to surrounding nature (High Contact) is affected by 3 indicators, such as contact to nature and diverse green areas, water intimate '||'&'||' contact areas, and natural ecology observation by biotope. Finally, the dimension of environmental health and amenity is affected by 3 indicators, such as nature affinity by farming experience, environmental-friendliness of soil '||'&'||' crops by organic farming, campaign and education programs of environmentally-friendliness. From the result of Importance-Performance Analysis(IPA) for 10 indicators, environmentally-friendliness was recommended as 'Concentrate Here'. And, the content validity of 10 indicators for 3 categories was examined by factor analysis. The result showed as the same as hypothetical model, which proved the validity of hypothetical model.

• KIEAE Journal
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• v.13 no.4
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• pp.87-94
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• 2013

This Study, as a Eco-Friendly Design Process of Office for sustainable design, aims to develop a sustainable design process by letting the designers easily approach the concept of Eco-Friendly Design Process and applying this to Eco-Friendly Design Process when the designers perform design. Through a review on simulation, a research was made on the seriousness of environmental problems and control that was caused by design, Environmentally friendly design, sustainability, and sustainable design's background and definition were studied. In order to develop a Eco-Friendly Design Process, an existing review from Building Energy Simulation that proposed about energy environmentally friendly design element and sustainable design element's semantic similarities were restructured as sustainable design element comparative analysis. Restructured sustainable design elements and the relationship between sustainable design elements and the relationship of each product developmental process levels were analyzed. Finally, through clustering, sustainable design guideline were developed. This Eco-Friendly Design Process is expected to be applied to as one of the methods in solving the global environmental issues in design practice.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.59-63
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• 2011

Friction damping is one of the attractive vibration control technique for space structures due to its simplicity and large damping capacity. However, passive approaches for friction damping have a limitation because energy is no longer dissipated at sticking. In order to overcome this problem, semi-active control methods to adjust normal force at frictional interface have been studied in previous researches. In this paper, two semi-active friction control method is compared by simulating SDOF model of truss structure. The first approach is on-off control to maximize rate of energy dissipation, whereas the second concept is variable friction force control to minimize amplitude ratio for each half period. The maximum friction force, control variable in on-off control method, is obtained to minimize 1% settling time, and is different from optimal friction force in passive control. Simulation results show that performance of on-off control is better than that of variable friction force control in terms of settling time and controlled friction force.

• Journal of the Korean Institute of Educational Facilities
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• v.26 no.4
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• pp.27-34
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• 2019

Recently the architectural paradigm have been changing into eco-friendly architecture as an sustainable architecture. This social background encourages the development of various methods of building applicable for eco-friendly buildings in architectural design. Among them, passive architecture is an design approach for eco-friendly design that contrasts with technology-based methods through MEP for renewable energy. This study researches the Passive Architectural Design methodology with two points of view; Passive Architectural Design Techniques as a guideline, which defines the elements to consider for passive architecture, and the project of Sejong Municipal Public Library as a case, which is to analysis the architectural design process. The purpose of this study is to propose an eco-friendly public building based on the methodology which is suitable for passive architectural design. Finally, this study suggests that the eco-friendly public building design for passive architecture should consider from the early step of design process, such as concept and building form etc. What is important for the passive architecture is not how much building can produce the natural energy but how less building consumes it to maintain.

• International Journal of Highway Engineering
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• v.17 no.6
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• pp.47-54
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• 2015

PURPOSES : The objective of this study is to evaluate the early adhesive characteristic of asphalt emulsions, including polymer-modified emulsions, for chip seals using the surface energy concept, the bitumen bond strength (BBS) test, and the Vialit test. METHODS : Two general methods, the BBS test and Vialit test, were applied to investigate the bond strength and the aggregate loss, respectively. A new theory, the surface free energy (SFE) theory, was used to evaluate the adhesive characteristic between the emulsion and the aggregate. Based on the theory, the contact angles were measured, and then the surface energy components were calculated. Using those components, the work of adhesion (Wa) was calculated for each emulsion. To ensure reliable results, all the tests were performed under the same conditions, i.e., at $25^{\circ}C$ for 240 minutes of curing time. For the materials, three emulsions (CRS-2, CRS-2L, and CRS-2P) and one aggregate type (granite) were employed. RESULTS AND CONCLUSIONS : Under the same conditions, the modified emulsions showed better adhesive characteristics and curing behaviors than the unmodified emulsions. In addition, there was no significant difference between the various modified emulsions. One of the important findings is that the analysis by Wa presents more sensitive results than other methods. The results of the Wa showed that the CRS-2P emulsion has the best adhesive characteristics. Consequently, the use of modified emulsions for chip seals could prevent aggregate loss and allow open traffic earlier.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.11
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• pp.1495-1504
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• 2013

Renewable energy integration and increased system complexities make system operator maintain supply and demand balance harder than before. To keep the grid frequency in a stable range, an appropriate spinning reserve margin should be procured with consideration of ever-changing system situation, such as demand, wind power output and generator failure. This paper propose a novel concept of dynamic reserve, which arrange different spinning reserve margin depending on time. To investigate the effectiveness of the proposed dynamic reserve, we developed a new short-term reliability criterion that estimates the probability of a spinning reserve shortage events, thus indicating grid frequency stability. Uncertainties of demand forecast error, wind generation forecast error and generator failure have been modeled in probabilistic terms, and the proposed spinning reserve has been applied to generation scheduling. This approach has been tested on the modified IEEE 118-bus system with a wind farm. The results show that the required spinning reserve margin changes depending on the system situation of demand, wind generation and generator failure. Moreover the proposed approach could be utilized even in case of system configuration change, such as wind generation extension.

• Clean Technology
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• v.2 no.2
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• pp.201-213
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• 1996

Environmental regulation has traditionally focused on specific phenomena and adopted the so-called end-of-pipe approach. Recently, however, the new environmental paradigm is more concerned with minimization of waste generation, efficient material and energy use, pollution prevention, etc. The basis of above concept is that one must consider the environmental impacts of a product not only during its manufacturing stage, but during all life stages. In the present study, the current status of LCA and its importance to environmental impacts have been reviewed. In the usual approach to LCA, screening LCA method has been used to promote international competition and define environmental concerns during semiconductor manufacturing. In the present study, a review of semiconductor manufacturing process and its environmental implication has been conducted to quantify the material and energy requirements, minimize the waste generation, and evaluate production cost. Recommended activities are also specified for process modification to improve the process efficiency.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.3
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• pp.453-460
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• 2014

Fault injection attack is the process of attempting to acquire the information on-chip through inject artificially generated error code into the cryptographic algorithms operation (or perform) which is implemented in hardware or software. From the details above, the laser-assisted failure injection attacks have been proven particularly successful. In this paper, we propose an improved laser probing system for fault injection attack which is called the Dual-Laser FA tool set, a hybrid approach of the Flash-pumping laser and fiber laser. The main concept of the idea is to improve the laser probe through utilizing existing equipment. The proposed laser probe can be divided into two parts, which are Laser-I for laser cutting, and Laser-II for fault injection. We study the advantages of existing equipment, and consider the significant parameters such as energy, repetition rate, wavelength, etc. In this approach, it solves the high energy problem caused by flash-pumping laser in higher repetition frequency from the fiber laser.

• Journal of Radiation Protection and Research
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• v.48 no.2
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• pp.68-76
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• 2023

Background: In the process of discussion on the possibility of using radionuclide-contaminated soil and debris generated by radiation disasters, a strategy for the proper management of radiation exposure protection while considering the source of the contaminated materials is necessary. Materials and Methods: The radiological protection criteria that are likely to be applied to the source-related approach based on the International Commission on Radiological Protection recommendations and the International Atomic Energy Agency safety standards are summarized. We proposed five interpretations of radiation protection to contribute to the promotion of discussion on the possibility of using a part of low-level-radionuclide-contaminated soil and debris in the post-accident rehabilitation. Interpretations I to III are based on the idea of "using a reference level to protect the public in post-accident rehabilitation," whereas IV and V are based on the idea of "using the dose constraint to protect the public in the post-accident rehabilitation when the sources are handled in a planned activity." The former idea is subdivided into three based on the definition of the source, which is managed by the reference level, and the latter idea is divided into two depending on whether or not additional dose from using contaminated materials is deemed acceptable. Results and Discussion: To confirm the applicability of the five interpretations presented, we suggested the concrete values of protection criteria via two feasible cases. In this case study, we proposed radiation protection by the dose constraint based on the Interpretation IV and chose 1 mSv/yr for the public and 20 mSv/yr for workers dealing with radionuclide-contaminated materials. Conclusion: We concretely and systematically demonstrated how the concept of radiation protection can be applied to the process of discussion on the possibility of using radionuclide-contaminated materials within the framework of an international system of protection. This study's findings can provide necessary information to discuss the possibility of using radionuclide-contaminated materials as an alternative option for recovery and reconstruction after a radiation disaster from the viewpoint of radiation protection.