• Journal of Aerospace System Engineering
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• v.14 no.1
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• pp.21-27
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• 2020

Aircraft should be equipped with various external stores for mission performance. Since these external stores may cause structural instability of aircraft, an evaluation of the effects between the aircraft and the external stores is required. For this purpose, an aircraft dynamic characteristics analysis reflecting an external store was performed, and the finite element model for the analysis of aircraft dynamic characteristics should simulate the dynamic characteristics of the component as accurately as possible while using a minimum of the nodes and elements. In this study, a stick model was constructed for dynamic characteristics analysis of the external fuel tank and installation pylon using MSC Patran/Nastran. For the calculation of the equivalent stiffness of the stick model, a simple beam theory was applied to construct the stick model of each part, and the validity of each stick models was confirmed by mode comparison with the fine model. Additionally, the model analysis of the stick model assembly, simulating a pylon equipped with an external fuel tank was performed to confirm that the basic modes required for the analysis of aircraft dynamic characteristics are well extracted. Finally, it was confirmed that the developed stick model assembly could be used for analysis of aircraft dynamic characteristics by comparing the errors in modes between the fine model assembly and the stick model assembly.

• Korean Journal of Agricultural Science
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• v.42 no.3
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• pp.191-199
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• 2015

We conducted this research to observe the changes of surface morphology and composition of clay minerals influenced by various concentrations of fluoric acid. Hydrofluoric acid (HA), a solution of hydrogen fluoride (HF) in water, is a colourless solution that is highly corrosive, capable of dissolving many materials, especially oxides. To do this, we treated several concentrations of HA on the ground soil samples collected from the agricultural experimental station located at Chungnam National University to observe the influence of fluoric acid on the changes of surface structures and elemental composition of clay particles. Generally, microscopic examination showed that the HA can not only attack an edge of clay particles but also start at any point where structural defects and weaknesses predisposed sites to acid. The orderly flake arrangement of clay minerals may reflect certain crystal symmetry elements. The ESEM-EDS results of element composition of clay particles influenced by HA indicated the changes of structures of clay minerals. It is also clear from the formation of etch figures and element composition of clay particles that the product layer at least partially dissolved or disintegrated in the presence of acid. Conclusively, the clay structures can be strongly influenced by concentrations of HA, resulting in changes of physical and chemical properties that can determine the behavior of solute transport as well as mobility of ions in soils.

• Journal of the Korean Geographical Society
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• v.39 no.4
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• pp.562-584
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• 2004

This paper intends to identify the structure of homogeneous regions and functional regions in Seoul based on B.J.L. Berry's ‘general field theory of spatial behavior’. The structure of homogeneous regions by using socio-economic variables can explain how the structural elements of the city are arranged. It can be ssid that Seoul has shifted towards more complicated and differentiated features in terms of homogeneous regions. The different patterns are found between the northern part to Han River where old torn areas are located and the southern part to Han River where newly urbanized areas are located. Usually, the concentric pattern and the sectoral pattern coexist, which is enhanced moving from CBD to the outskirt area. The distribution of different social classes shows irregular pattern similar to the variation of living environment. The social gap is expected to be more widening between new towns and old towns. The analysis of spatial movement pattern shows no clear hierarchical order because of current shifts towards both multi-nuclear pattern and spatial dispersion. The functional regions show duplicated structure overlapping their boundaries each other. The ‘general field theory of spatial behavior’ strongly suggests that spatial interactions among sub-areas in the city are differentiated from the basic characteristics and function of each sub-area. The attributes of homogeneous regions and functional regions are interrelated in the characteristics of isomorphic nature.

• Journal of the Korea Concrete Institute
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• v.28 no.2
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• pp.167-176
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• 2016

Shear friction strength model of concrete was proposed to explain the direct friction mechanism at the concrete interfaces intersecting two structural elements. The model was derived from a mechanism analysis based on the upper-bound theorem of concrete plasticity considering the effect of transverse reinforcement and applied axial loads on the shear strength at concrete interfaces. Concrete was modelled as a rigid-perfectly plastic material obeying modified Coulomb failure criteria. To allow the influence of concrete type and maximum aggregate size on the effectiveness strength of concrete, the stress-strain models proposed by Yang et al. and Hordijk were employed in compression and tension, respectively. From the conversion of these stress-strain models into rigidly perfect materials, the effectiveness factor for compression, ratio of effective tensile strength to compressive strength and angle of concrete friction were then mathematically generalized. The proposed shear friction strength model was compared with 91 push-off specimens compiled from the available literature. Unlike the existing equations or code equations, the proposed model possessed an application of diversity against various parameters. As a result, the mean and standard deviation of the ratios between experiments and predictions using the present model are 0.95 and 0.15, respectively, indicating a better accuracy and less variation than the other equations, regardless of concrete type, the amount of transverse reinforcement, and the magnitude of applied axial stresses.

• Journal of the Korea Concrete Institute
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• v.26 no.3
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• pp.267-275
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• 2014

Recently, the construction of curved bridge has increased, thus researchers perform the analytic studies on PSC curved bridge. However, the grid analysis method that are mostly used in the construction industry is not adequate to acquire the precise behavior evaluation of curved PSC briges. Therefore, the precise finite element analysis considering the effective variables were performed to establish the basis for the design method of curved PSC bridge by using 3D elements and bar element. The evaluated variables in this analysis were the number of girders, loading point, section figure, change of prestressing force. The results show the load carrying capacity of the 3 girder type bridge is 200% of that of the 2 girder type, and that applying load on outer girder makes the load resistance capacity and the deflection deviation of 2 girders smaller. The structural capacity of the bridge is improved when the section size is increased, but the efficiency of it is not sufficient enough compare to that of the change of prestressing forces. The change of prestressing forces shows that the camber and the load carrying capacity are linearly increased as PS force is increased. Moreover, when the PS force applied on outer girder is increased than that of inner girder, the deviation of deflection the girders decreases, thereby the stability of the bridge is enhanced.

• Journal of Korean Association for Spatial Structures
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• v.4 no.2 s.12
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• pp.63-71
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• 2004

The structural space is gradually wide and is wanting agreeable environment by the requirement and necessity of people who lives modem stage. The building coincides with such requirements and is the high rise building actual circumstances which is doing ultra-large. The confirmed report of the technology to organize great merit is becoming currently considerably important issue in constructing a building field. Thus, this paper examine closely for nonlinear unstable taking a picture uneasiness height of prosperity considering to initial imperfection by a numerical method with a space frame structure of discrete system in large space structure. Based on previous investigation method, this paper induce nodal stiffness matrix of solid truss elements considering geometrical nonlinear using finite element method. In this paper, three types of space structure considered; i) 1-free node space structure, ii) 2-free node space structure, iii) multi-free node space structure. It apply the above examples to a nonlinear program, next, grasp the characteristic of an unstable conduct and the result was a clearing low.

• Journal of the Korean Society of Marine Environment & Safety
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• v.9 no.1
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• pp.51-56
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• 2003

The prevention of marine accidents has been a major topic in marine society for long time and various safety policies and Countermeasures have been developed and applied to prevent those accidents. In spite of these efforts, however significant marine accidents have taken place intermittently. Ship is being operated under a highly dynamic environments and many factors are related with ship's collision and those factors are interacting. So, the analysis on ship's collision rouses are very important to prepare countermeasures which will ensure the safe navigation. This study analysed the ship's collision data over the past 10 years(1991-2000), which is compiled by Korea Marine Accidents Inquiry Agency. The analysis confirmed that ‘ship's collision’ is occurred most frequently and the cause is closely related with human factor. The main purpose if this study is to propose risk control countermeasures of ship's collision. For this, the structure of human factor is analysed by the questionnaire methodology. Marine experts were surveyed based on major elements that were extracted from the human factor affecting to ship's collision FSM has been widely adopted in modeling a dynamic system which is composed of human factors. Then, the structure analysis on the rouses of ship's collision using FSM are performed. This structure model could be used in understanding and verifying the procedure of real ship's collision. Furthermore it could be used as the model to prevent ship's collision and to reduce marine accidents.

• 모자간호학회지
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• v.2 no.1
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• pp.70-86
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• 1992

What is the meaning of menopause experienced by urban Korean women? Nurses need an under standing of menopause as it is experienced by women themselves. Nursing needs to build knowledge of womens' health experiences. This phenomenological study examined what menopause means to modern Korean woman to build a structure of knowledge useful for practice to enhance the quality of life of women throughout this experience. Traditional definition of menopause according to physiological changes, as illness and more recently as psychosociocultural phenomena were examined along with the folk lore information generally available in the society A review of the research and scientific literature was done from the perspectives of four models including the medical model of menopause as disease, the psychosocial model as positive and negative behavioral responses to menopause, a feminist model of menopause as a time of rebirth and a nursing model of the changing patterns of meaning, rythms and transformation women experience through menopause. Van Kaam's method was used to analyse data audio-recorded during interviews by the investigator with 65 women, 40 to 60 years of agey whose confidentility was assured. Interpretation of the data was enhanced luther by consultation with professional colleugues and with informants. Four rhythmical patterns of process emerged : from suffering to comfort, from oppression to freedom from being a good wife and wise mother to becoming a woman and from a hard life to an abundant life. The detailed common elements making up each of the four patterns and definitions of each pattern were presented. Each pattern was discussed critically from the point of view of medical, psychosociocultural, womens' and nursing models. The structural definition of the synthesis of the four process patterns was stated as : in spite of suffering the middle-aged urban Korean woman find she is able to help herself to feel comfortable and to realize release as she moves from oppression to liberation and freedom from being a good wife and wise mother she experiences rebirth as a woman : she begins to live a profitable and valuable life : her life becomes one of transformed abundant living. The definition transcends the medical and phychosociocultural model to embody a nursing model. The analysis was critiqued by using Parse' Human Becomming theory of nursing because the emerging themes were process patterns. Parse' theory provides and explanation of the experience of menopause consistant with the data which enhances nursing understanding of womens' experience of menopause. Parse' practice methodology provide guidance for promoting womens' quality of life throughout the experience of menopause. Feminist analysis contributes valuable critique to nursing research, richly expanding the perspective from traditional approaches to promote understanding of the meaning of womens' health experiences.

• Science of Emotion and Sensibility
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• v.13 no.4
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• pp.741-752
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• 2010

City culture resources are critical elements to city brand strategies for improving city attraction and provide much contribution to induce visitors from competitive city. A city brand needs to be distinguished and differentiated from competing cities because they are all engaged in the similar environment of city. The differentiation of brand achievement has become increasingly important to highlight certain brand functions to include emotional, self-expressive, and symbolic functions since the importance of such functions has been further emphasized in promoting tourism activities. In particular, That is the recent role of city brand personality that has been emphasized in city management. In other words, visitors now freely and actively express their personalities or egos in tourism activities, taking an important role in construction of a brand asset. The study examines how culture resources affect city brand personality, relationship quality, and city brand royalty in the tourism city. The authors test the proposed model using data from Jeju tourists. The pivotal findings via the structural equation model in the study are as follows; 1) culture resources have been classified culture programs, culture infra, human resources, 2) The city brand personality has been classified as innovativeness, peacefulness, sophistication, confidence and dynamics; 3) The culture resources influenced on the city brand personality; 4) The city brand personality influenced on the satisfaction and involvement; 5) The satisfaction and involvement influenced on the loyalty. Results from the empirical study indicates that culture resources have a strong positive impaction on city brand personality. To increase tourist' royalty of city brand personality, managements must manage culture effectively and create friendly city brand personality to in accord with tourist needs.

• Journal of architectural history
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• v.8 no.3 s.20
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• pp.23-38
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• 1999

The purpose of this study is to analogize the appearance of Korean Ancient Architecture in view of the Stone Remains from 3 Kingdom Period to Unificated Shilla Period. But in these period, there is no building remains but some stupas and fine arts. Especially, there are many architectural appearance and revealing signature in these Historical Stone remains. Architectural elements which are analogized by stone remains what has value as historical materials by preservation of original form from 3 Kingdom Preiod to Unificated Shilla Period are as follows : 1) Platform, the representative characteristic of Korean traditional architecture, was frame structure and accumulate structure. And circular or square footing stood a same shape column on it is put on the platform. 2) In the case of column, there used entasis column and inclined column and circular chamfer technique was applied on the top side of it. Upper side of column, capital and head pentrating tie that small bearing block was put on the center of it was joined. And longitu야nal rest(長舌) supported a cross beam. Capital and small bearing block had no bottom heel, and heel side was curved and straight. Centered bracket structure was often used, and multi bracket structure is not used yet. Inward incline technique was used. 3) Inward opening pair door which had lintel, threshold, doorjamb was usually used, Fixing stone was used for structural safety, and circular handle and lock was used for decoration. Handrail was used on the edge of wooden floor for decorative effect and safety. 4) Square rafter and circular rafter were used in the same period and so did flying rafter. Double eaves and single eave were used in the same period but, single eave was usually used. In this period, square rafter was usually used. This would be studied more by comparing with Japanese wooden architecture. 5) Hipped roof was used and half-hipped roof was not used yet. In front of th hip, there are small sculpture called Jap-Sang(雜像), and windbell was hang on the end of the hip rafter. Concave roof tile, convex roof tile, round eaver tile, decorative tile at end of roof ridge were used. Lotus style was well used on the face of roof tile for decoration. From the results of this study, wooden architecture of Unificated Shilla period was simple compare to Koryo dynasty and Chosun dynasty but, it had some brilliant character. It was hard work that analogized the form of non-existent wood architecture of Ancient Korean period by restricted stone remains. But, in addition to the results of this study and research of old documentations, more study should be go on.