• The Journal of the Acoustical Society of Korea
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• v.43 no.2
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• pp.214-224
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• 2024

Sonobuoys are disposable devices that utilize sound waves for information gathering, detecting engine noises, and capturing various acoustic characteristics. They play a crucial role in accurately detecting underwater targets, making them effective detection systems in anti-submarine warfare. Existing sonobuoy deployment methods in multistatic systems often rely on fixed patterns or heuristic-based rules, lacking efficiency in terms of the number of sonobuoys deployed and operational time due to the unpredictable mobility of the underwater targets. Thus, this paper proposes an optimal sonobuoy placement strategy for Unmanned Aerial Vehicles (UAVs) to overcome the limitations of conventional sonobuoy deployment methods. The proposed approach utilizes reinforcement learning in a simulation-based experimental environment that considers the movements of the underwater targets. The Unity ML-Agents framework is employed, and the Proximal Policy Optimization (PPO) algorithm is utilized for UAV learning in a virtual operational environment with real-time interactions. The reward function is designed to consider the number of sonobuoys deployed and the cost associated with sound sources and receivers, enabling effective learning. The proposed reinforcement learning-based deployment strategy compared to the conventional sonobuoy deployment methods in the same experimental environment demonstrates superior performance in terms of detection success rate, deployed sonobuoy count, and operational time.

• Journal of the military operations research society of Korea
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• v.1 no.1
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• pp.111-129
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• 1975

U.S. Air Force Regulation 80-1 defines that a weapon system is composed of equipments, skills, and techniques, the composite of which ferns an instrument of combat. The complete weapon system includes all related facilities, equipments, materials, services, and personnels required for the operation of the system, so that the instrument of combat can be considered as a self-sufficient unit of striking power in its intended operational environment. Effectiveness of a weapon system can be expressed as a function of its liability, reliability and performance capability. Among these attributes which influence the weapon effectiveness, performance capability is considered to be the most critical factor for many weapon systems. In order to illustrate the application of the methodology of performance capability, a specific ease study on the effectiveness of Vulcan anti-air craft gun system is presented with special emphasis on hitting probability on moving targets, effects of artificial rounds dispersion, and several principles related to the deployment of the system. This thesis includes the thorough survey of the possibility of calculating the absolute value of hitting probability on moving targets, indicates that the effects of artificial rounds dispersion increase the value of probability only when the total number of rounds fired within fire range exceeds a certain critical number, and suggests that concentrated guns deployment is better than scattered deployment in order to obtain higher probability and lower average amount of rounds if it is assumed that the effects of counter-attack from enemy threats are not serious.

• Journal of Korean Society for Quality Management
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• v.41 no.2
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• pp.197-208
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• 2013

Purpose: This study proposed a systematic approach to measure eco-efficiency of products based on the concept of quality function deployment(QFD). QFD method has been used to convert customer's subjective requirements to design specifications. A extension of QFD to environmental issues is known as quality environmental function deployment(QEFD). QEFD includes environmental requirements into customer's demand for quality, and incorporates them to design specifications of a product. Methods: In this study, we compared eco-efficiency of old and new models through application of QEFD. Results: The result revealed that the new model's eco-efficiency improved 24% better than the old model. Also, we found that user's Factor X of the new model has been improved to 1.178, which is about 18% better than that of the old model. Conclusion: This study implied that we can systematically use QEFD to determine eco-efficiency of two comparable products in any industries.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.3
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• pp.421-430
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• 2010

This work describes a derivation process of JIC(Joint Integrating Concept) based JFC(Joint Functional Concept) analysis of an Aegis BMD(Ballistic Missile Defense). JIC is developed through JOC(Joint Operating Concept) and JFC based on capstone strategy and concept. Aegis BMD is a sea-based ballistic missile defense to detect ballistic missile threat, increase engagement battlespace and enable multiple engagement based on Aegis ships. Aegis BMD is a good case of JIC due to performing an Joint operations based on System of Systems under highly complicated NCW environment. This work analyses JFC using QFD(Quality Function Deployment) and UJTL(Universal Joint Task List). From this analysis the JIC of Aegis Korean BMD is derived using a CASE tool.

• Korean Journal of Community Nutrition
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• v.8 no.5
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• pp.744-754
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• 2003

At present, health care industries throughout the world are struggling with the challenges to set up financial structures as cost-effective ways and means of satisfying customer needs for health care services. Many hospitals consign foodservice management to foodservice companies for the purpose of efficiency. The companies taking charge of hospital foodservice are also striving to gain an advantage over keen competitions. This study applied Quality Function Deployment(QFD) to one hospital (which will be shown as $\ulcorner$A hospital$\lrcorner$ below) managed by a contract foodservice company for the purpose of strategy planning to provide sustainable competitive advantage. First of all, this study scanned internal and external environment of $\ulcorner$A hospital$\lrcorner$ by means of a Quality Measurement Tool and a fieldwork study. With the result of environment scanning, this study elicited 20 strategies through SWOT analysis, which were categorized by 4 perspectives such as financial, customer, internal process, learning and growth perspectives. Finally, the priorities of 20 strategies were extracted from QFD methodology. According to the results obtained by applying QFD to $\ulcorner$A hospital$\lrcorner$'s foodservice, the strategies which $\ulcorner$A hospital$\lrcorner$ foodservice was obliged to introduce and implement were : the specialization of Children's hospital foodservice, scientific foodservice management through the standardization of foodservice operations, the maintenance of sanitary quality through sanitary system, the remodeling of facilities, the introduction of new equipment, the prompt and accurate response to customer needs, the development of appropriate patient menus, the provision of competitively priced meals for patient selection, the development of a demand forecast model by considering the characteristics of a children's hospital, improvement of productivity and the reduction of labor costs through the employment of experienced employees based on their seniority.

• Journal of Aerospace System Engineering
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• v.8 no.1
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• pp.36-41
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• 2014

KAFASAT is a CubeSat which has a high level mission of testing the possibility of establishing the LEO satellite constellation providing the role of communication nodes and quasi-realtime image recognition of battlefield in accordance with the aspect of future-war-environment. The high level mission is developed using the Pugh selection method, which is one of system engineering tools. In order to accomplish the high level mission objectives and deduce engineering level requirements, system engineering tools such as Analytic Hierarchy Process and Quality Function Deployment are used. The subsystem synthesis in the context of system engineering process is done using a developed integrated design environment. The paper also includes the conceptual design results of the KAFASAT, which can be used as a baseline for upcoming preliminary design.

• Proceedings of Korean Society of Archives and Records Management
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• 2019.05a
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• pp.35-41
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• 2019

Providing efficient recording information services has become vital in a utilization-oriented records management environment and further increasing the importance of the quality of the services offered. This study is a preliminary study to propose improvement measures by applying Quality Function Development (QFD), a quality control method, to the National Archives of Korea (NAK) and Records Information Service. The quality dimensions of the recording information service were analyzed, and specific user requirements were derived. Through this process, the user requirements' questionnaire was developed, reflecting the characteristics of the NAK, and the application model of QFD was designed based on its prior study. Based on the QFD application model proposed, the results obtained by performing the QFD step by step can be expressed in House of Quality (HoQ), which can be used as a basis for service design.

• Journal of the Korea Institute of Building Construction
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• v.23 no.4
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• pp.417-428
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• 2023

The demolition of domestic infrastructures mirrors other significant construction initiatives in presenting a markedly high accident rate. A comprehensive investigation into the origins of such accidents is crucial for the prevention of future incidents. Upon detailed inspection, the causes of demolition construction accidents are multifarious, encompassing unsafe worker behavior, hazardous conditions, psychological and physical states, and site management deficiencies. While statistics relating to demolition construction accidents are consistently collated and reported, there exists an exigent need for a more foundational cause categorization system based on accident type. Drawing from Heinrich's Domino Theory, this study classifies the origins of accidents(unsafe behavior, unsafe conditions) and human errors(human factors) as per the type of accidents experienced during demolition construction. In this study, a three-step model of QFD-FMEA(Quality Function Deployment - Failure Mode Effect Analysis) is employed to systematically categorize accident causes according to the types of accidents that occur during demolition construction. The QFD-FMEA method offers a technique for cause classification at each stage of the demolition process, including direct causes(unsafe behavior, unsafe environment), and human errors(human factors) through a tri-stage process. The results of this accident cause classification can serve as safety knowledge and reference checklists for accident prevention efforts.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2973-2978
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• 2011

In this paper, a system is developed to support multi-attribute decision making for designing light-weight of rolling stock. Conceptual design of light-weight of rolling stock does not only mean reducing weight. It should be considered about some attributes like safety and environment, technology, etc. So technical attributes and needs of customers, manufacturers and management companies, passengers, should be reflected and qualitative evaluation methods are required. AHP(Analytical Hierarchy Process) and QFD(Quality Function Deployment) are used to decide weighted values of technical attributes and needs from customers. Finally, Alternatives for light-weight of rolling stock that are composed of alternatives of equipment are evaluated by TOPSIS(Technique for Order Preference by Similarity to Ideal Solution). A series of this process are made as a S/W. It could suggest a near-optimal alternative for light-weight of rolling stock.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.1
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• pp.72-81
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• 2007

This study mainly aims at suggesting plans applicable to the outdoor of environment-friendly communities in Korea by leveraging more natural conditions and materials when creating an outdoor biotop for an environment-friendly community and generating material types and development techniques enabling a natural circulation system. To this end, materials used in the outdoor of environment-friendly communities and traditional residential areas in Korea and biotop materials found in natural areas were examined. First, when the case examples of environment-friendly communities were reviewed, biotop spaces and materials that may function as habitats were hardly found. Materials used in biotop were mainly man-made structures made of artificial or processed materials, such as concrete, stones, bricks, woods and steels. Meanwhile, the outdoor space of traditional Korean villages had stone walls, soil walls, rock piles and composite piles, which composed of natural materials such as rocks, soil and plants, that naturally formed porous spaces along with the introduction of plants and provided habitats for a variety of insects. In natural areas, naturally created biotop spaces, such as rock piles, log piles, old tree deployment, branch piles, hay stacks and defoliated leaves, were found. Meanwhile, when spaces and materials available for biotop creation were reviewed to create an environment-friendly residential complex, they were divided into fences and hedges, green spaces between parks and residential buildings, ponds and waterscape spaces, zones separating pedestrian walks and roadways, breast walls and slope boundary, plant box and pergola. For each space, materials used for creating biotops and that were found in traditional Korean residential areas and natural areas were applied and suggested.