• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.266-271
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• 2009

A modeling method for the modal analysis of a multi-packet blade system having a crack undergoing rotational motion is presented in this paper. Each blade is assumed as a slender cantilever beam. The stiffness coupling effects between blades due to the flexibilities of the disc and the shroud are modeled with discrete springs. Hybrid deformation variables are employed to derive the equations of motion. The flexibility due to crack, which is assumed to be open during the vibration, is calculated basing on a fracture mechanics theory. To obtain more general information, the equations of motion are transformed into dimensionless forms in which dimensionless parameters are identified. The effects of the dimensionless parameters related to the angular speed, the depth and location of a crack on the modal characteristics of the system are investigated with some numerical examples.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.4
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• pp.745-750
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• 2009

The goal of this study is to examine on reasoning and search for construction of diagnosis ontology as a knowledge base of diagnosis expert system in oriental medicine. Expert system is a field of artificial intelligence. It is a system to acquire information with diverse reasoning methods after putting expert's knowledge in computer systematically. A typical model of expert system consists of knowledge base and reasoning & explanatory structure offering conclusion with the knowledge. To apply ontology as knowledge base to expert system practically, consideration on reasoning and search should be together. Therefore, this study compared and examined reasoning, search with diagnosis process in oriental medicine. Reasoning is divided into Rule-based reasoning and Case-based reasoning. The former is divided into Forward chaining and Backward chaining. Because of characteristics of diagnosis, sometimes Forward chaining or backward chaining are required. Therefore, there are a lot of cases that Hybrid chaining is effective. Case-based reasoning is a method to settle a problem in the present by comparing with the past cases. Therefore, it is suitable to diagnosis fields with abundant cases. Search is sorted into Breadth-first search, Depth-first search and Best-first search, which have respectively merits and demerits. To construct diagnosis ontology to be applied to practical expert system, reasoning and search to reflect diagnosis process and characteristics should be considered.

• Journal of Korean Academy of Nursing
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• v.37 no.7
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• pp.1119-1130
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• 2007

Purpose: This study was done to develop the concept of grief focusing on the process of spousal bereavement in Korea. Methods: The Hybrid model was used for analysis according to the 3 phases. An extensive literature review was done for the Theoretical phase. In-depth interviews were conducted with 15 participants whose spouses died within the past 3 years in the Field phase. In the Final analytic phase, the results in the Theoretical and the Field phases were compared, analyzed, and integrated according to the process of grief. Results: The antecedent of the concept of spousal grief was spousal death. The dimensions of grief were classified to inner dimensions related to oneself, relational dimensions related to family and others, and existential dimensions related to the meaning of being. The attributes of grief were physical suffering, decline of cognitive ability, heartbreaking sorrow, expectations and conflicts of a new life, social stigma, dependence on or resentment towards God, etc. The empirical referent of grief was physical, psychological, social, and spiritual health status. The grieving progressed through 3 phases-shock-emancipation, suffering, and integration. Conclusion: Nurses should recognize the importance of their unique position as supporters for grievers, and try to assess individual characteristics and to provide tailored nursing interventions.

• Journal of the Korean Society of Combustion
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• v.11 no.2
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• pp.7-14
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• 2006

Catalytic combustion is one of the suitable methods for micro power source due to high energy density and it can be applied to micro structured chamber without consideration of quenching since it is flameless combustion. Catalyst loading in the micro structured combustion chamber is one of the most important issues in the development of micro catalytic combustors. In this research, to coat catalyst on the chamber wall, two methods were investigated. First, $Al_2O_3$ was selected as a support of Pt and $Pt/Al_2O_3$ was synthesized through the alumina sol-gel procedure. To improve the coating thickness and adhesion between catalyst and substrate, heat resistant and water solvable organic-inorganic hybrid binder was used. Porous silicon was also investigated as a catalyst support for platinum. Through the parametric studies of current density and etching time, fabrication process of $1{\sim}2{\mu}m$ of diameter and about $25{\mu}m$ depth pores was confirmed. Coated substrates were test in the micro channel combustor which was fabricated by the wet etching and machining of SUS 304. Using $Pt/Al_2O_3$ coated substrate and Pt coated porous silicon substrate, conversion rate of fuel was over 95 % for $H_2/Air$ premixed gas.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.1
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• pp.1-17
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• 2013

The investigation for species composition and catch in the Korean deep-water of the East Sea (also known as Sea of Japan) was carried out with trammel nets of 7 mesh sizes (6.1~24.2cm) offshore Donghae (2006) and Yangyang (2007) of Korea. The catches were 1,268kg and composed of 37 species between 200m and 1,200m in depth. The principal species caught were Taknka's snailfish, salmon snailfish, red snow crab, hunchback sculpin, snow crab, spinyhead sculpin, Tanaka's eelpout, Alaska cod and so on. Those were target fish for commercial value except salmon snailfish. The mesh sizes for the largest catch were 10.6cm and 15.2cm in the fishing ground of Donghae and Yangyang, respectively. The habitat of snow crab was shallower than that of red snow crab in both areas. Trammel net enabled to investigate fish in deep-water with small fishing vessel and rather cheap expenses in contrast to bottom trawl that required too much of it. With increasing inner mesh size of trammel net the mean size of some principal species such as Taknka's snailfish, spinyhead sculpin, hunchback sculpin, Pacific cod, snow crab, red snow crab and hybrid between snow crab and red snow crab tended to be large in certain range of mesh size.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.10
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• pp.1017-1024
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• 2002

In this paper, we present the analysis of radio wave propagation characteristics in curved tunnels. Tunnel propagation models are performed in two cases which are using ray-tracing method for straight tunnels and geometrical optics extension to the standard hybrid waveguide model for curved ones. By regression analysis for measured power based on distance between the transmitter and the received antenna in tunnels that have 3.5 m $\times$ 6 m cross section and limited wall depth path loss are 0.19 dB/m for straight section and 0.68 dB/m for curved ones. By comparing model analysis with measurement in tunnels, it has been shown that the simulated results of tunnel propagation models are similar to the measured values.

• Nuclear Engineering and Technology
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• v.42 no.5
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• pp.546-551
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• 2010

The objective of this research is to estimate the crack location and size of a carbon steel pipe by using a laser ultrasound guided wave for the wall thinning evaluation of an elbow. The wall thinning of the carbon steel pipe is one of the most serious problems in nuclear power plants, especially the wall thinning of the carbon steel elbow caused by Flow-Accelerated Corrosion (FAC). Therefore, a non-destructive inspection method of elbow is essential for the nuclear power plants to operate safely. The specimens used in this study were carbon steel elbows, which represented the main elements of real nuclear power plants. The shape of the wall thinning was an oval with a width of 120mm, a length of 80mm, and a depth of 5mm. The L(0,1) and L(0,2) modes variation of the ultrasound guided wave signal is obtained from the response of the laser generation/air-coupled detection ultrasonic hybrid system represent the characteristics of the defect. The trends of these characteristics and signal processing were used to estimate the size and location of wall thinning.

• The Research Journal of the Costume Culture
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• v.22 no.2
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• pp.313-325
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• 2014

This study seeks to establish a ubiquitous wardrobe with a clothing management function through detailed and subdivided integration research. To create a database, a survey was conducted, and the output data were analyzed and used as the basic data. In particular, this study researched clothing management programs and companies' standards of clothing product classification systems. First, through an in-depth analysis centering on specialists, we established the contents of a ubiquitous wardrobe and used the concept of cloud computing to support the wardrobe contents and smart phone applications. Second, this research found significant differences between individuals, schools, and enterprises in their applications of, and the importance they attach to, design images. A detailed database composed of various categories was established to present the ubiquitous wardrobe contents with efficient functions. Third, we facilitated the search process by designating clothes with QR codes, which is one of the functions of contents. Fourth, the code numbers generated in the process of entering clothes into the database were utilized as RFID information as a way to arrange the products in a simpler manner. The ubiquitous wardrobe was constructed as a web-style hybrid, and its contents areavailable through mobile applications and QR codes.

• Journal of Korean Academy of Nursing
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• v.50 no.1
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• pp.81-100
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• 2020

Purpose: The purpose of this study was to define and clarify the concept of political competence for nurses. Methods: A hybrid model method was used to investigate the dimensions, attributes, and definitions of the concept. In the theoretical stage of the study, literature on nursing, politics, and other discipline were reviewed. In the fieldwork stage, individual in-depth interviews and focus groups interviews were conducted with politically seasoned experts or activists who had an understanding of the concept of political competence for extensive descriptions in nursing and field of health care. Results: The concept of political competence was represented in four dimensions as political knowledge, political efficacy, political interaction, and political activity. In the political knowledge dimension, there were three attributes, namely, political knowledge, political information and systematic analysis ability. The political efficacy dimension had three attributes of internal political efficacy, external political efficacy, and self-pride of nursing profession. The political interaction dimension had three attributes of organizations and community service, networking, and persuasive power. The political activity dimension had six attributes of political leadership, political expression, assertive behavior, political advocacy, political participation, and policy intervention. Conclusion: This concept development might provide a basic understanding of developing a measurement tool and for constructing a theory promoting nurses' political competence.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.4
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• pp.506-516
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• 2007

In this paper, a study on low-velocity impact response of four different sandwich panels for the hybrid bodyshell and floor structure application of the Korean low floor bus vehicle was done. Square samples of 100mm sides were subjected low-velocity impact loading using an instrumented testing machine at six energy levels. Impact parameters like maximum force, time to maximum force, deflection at maximum force and absorbed energy were evaluated and compared for four different types of sandwich panels. The impact damage size and depth of the permanent indentation were measured by 3-Dimensional Scanner. Failure modes were studied by sectioning the specimens and observed under optical microscope. The impact test results show that sandwich panel with composite laminate facesheet could not observe damage mode of a permanent visible indentation after impact and has a good impact damage resistance in comparison with sandwich panel with metal aluminum facesheet.