• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1998년도 춘계학술대회 논문집
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• pp.298-303
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• 1998

Most of mechanical structures are combined of substructures such as beam and/or plates. There are few system with unibody structures but are not a few systems with united body structures. Generally the dynamic analysis of whole structures is perform ed under alternating load. However, the analysis of each joint area is more important than others for zero severity. This paper presents the results of analysis of concentration stress in bolt jointed structure with variable preload. At frist, a static vibration test was performed to find out a nominal stress of bolt joint ed plates from the relationship between natural frequency and nominal stress. Then a concentration stress was computed at contact point between bolt and plate in the structure. It is believed that the proposed method has promising implications for safer design with fatigue quality index of stress concentration factor and has merit for cost down and saving time at the beginning of vehicle development.

• 대한치과기공학회지
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• 제7권1호
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• pp.33-40
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• 1985

When full denture is being fabricated, pronounciation, recovery of aesthetics of function and mastificatory function should be satisfies for patients. To satisfy for the function of denture, following is the difference between this new way of fabricating and formerly one of it. 1. The size of fabricating tooth which is harmony of original oral structure for patients is deaded by manufacturing labial index and artificial tongue. 2. By the use of artificial tongue and labial index, the arranges of artificial tooth is to become harmony of oral structure. 3. Formation of gingival decided functional impression which is used by impression paste, is harmony of oral structure. Therefore, this full denture can be satisfied with pronouncing oral function of recovery of aesthetics as well as mastificatory through physiological movement of oral tissue not disturbed with anything but cooperated drastically. In manufacturing of this full denture, both dentist and dental technician under cooperation need to proceed the work on the base of importance of communication.

• Earthquakes and Structures
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• 제25권6호
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• pp.429-442
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• 2023

To study the seismic vulnerability of the composite material structure of adobe and timber, we collected and statistically analysed empirical observation samples of 542,214,937 m² and 467,177 buildings that were significantly impacted during the 179 earthquakes that occurred in mainland China from 1976 to 2010. In multi-intensity regions, combined with numerical analysis and a probability model, a non-linear continuous regression model of the vulnerability, considering the empirical seismic damage area (number of buildings) and the ratio of seismic damage, was established. Moreover, a probability matrix model of the empirical seismic damage mean value was provided. Considering the coupling effect of the annual and seismic fortification factors, an empirical seismic vulnerability curve model was constructed in the multiple-intensity regions. A probability matrix model of the mean vulnerability index (MVI) was proposed, and was validated through the above-mentioned reconnaissance sample data. A matrix model of the MVI of the regions (19 provinces in mainland China) based on the parameter (MVI) was established.

• 한국컴퓨터산업학회논문지
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• 제4권4호
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• pp.613-624
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• 2003

본 논문은 우선순위 큐와 접미어 트리로 색인 구조를 생성한 후. 이미지 시퀀스 데이터베이스에서 다차원 타임 워핑 거리 함수를 이용하여 유사한 이미지 서브시퀀스를 신속하고 정확하게 검색할 수 있는 방법을 제안한다. 본 논문에서 제안된 방법은 사전에 정의된 중요도에 따라 선별된 이미지 시퀀스로 구성된 우선순위 큐 색인의 이미지 서브시퀀스에 대한 유사성 거리 계산을 첫 단계로 시행하여 유사한 서브시퀀스집합을 얻고 만족할 결과를 얻지 못했을 경우에는 두 번째 단계로 나머지 유사 서브시퀀스에 대해 디스크 기반의 접미어 트리를 색인 구조체로 하여 유사한 서브시퀀스를 검색하는 것이다. 하한 거리 함수를 활용하여 질의 이미지 시퀀스와 유사한 이미지 서브시퀀스를 검색하는 과정에서 생성 가능한 오류를 방지 하면서 동시에 비 유사 이미지 서브시퀀스를 제거하도록 한다.

• 한국경영과학회지
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• 제37권2호
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• pp.73-88
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• 2012

Even though the final source selection of foreign weapon system purchase project in defense area is the most important phase, the standard evaluation index has not been developed. This paper provides an appropriate evaluation index using DEMATEL and ANP methods. First, the all possible evaluation criteria applied to the relevant previous literatures in domestic and overseas researches are derived and classified into groups. Second, DEMATEL method is used to determine the network structure representing the relations of cause and effect between groups and their sub-criteria. If isolated factors, not connected with other factors, are existed in the network structure, all factors except for the isolated ones are grouped as one large factor so that the independency between those ones is maintained. The weights of criteria are determined using AHP method if the criteria are independent relation and ANP method if the criteria are networked. The weights of higher and lower level criteria are then integrated and distributed as a point with respect to the decision making purpose. The developed evaluation index can be used as a standard one in various foreign weapon system purchase projects in defense area.

• 한국수산과학회지
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• 제51권5호
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• pp.571-578
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• 2018

Seasonal variability in algal community structure of the subtidal zone was examined at four study sites on the southeastern coast of Korea from February to November 2016. A total of 81 species of algae (8 green, 12 brown, and 61 red) were indentified. During the study period, the greatest number of species was observed at Sinamri (57 species) followed by Daesongri (50 species), Dongbaekri (47 species) and Gangyangri (42 species). Of the six functional seaweed forms, the coarsely-branched form was the most dominant, accounting for about 43% of the total species at Daesongri. The annual average biomass in wet weight varied from $700.59g/m^2$ at Sinamri to $1,712.45g/m^2$ at Daesongri. The parameters of seaweed community structures were as follows: dominance index (DI), 0.30-0.54; richness index (R), 4.92-7.05; evenness index (J'), 0.54-0.72; and diversity index (H'), 2.05-2.91.

• 국제초고층학회논문집
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• 제3권4호
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• pp.297-304
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• 2014

Recently, there have been some reported examples of structural collapse due to gravity, subsequent to damage from accident or an excitation that was not prepared for in the design process. A close view of new concepts, such as a redundancy and key elements, has been taken with the aim of ensuring the robustness of a structure, even in the event of an unexpected disturbance. The author previously proposed a sensitivity index of the vertical load carrying capacity to member disappearance for framed structures. The index is defined as the ratio of the load carrying capacity after a member or a set of an adjacent member disappears, to the original load carrying capacity. The member with the highest index may be regarded as a key element. The concept of bio-mimicry is being applied to various fields of engineering, and tree-shaped structures are sometimes used for the design of building structures. In this study a sensitivity analysis is applied to the irregular-framed structures such as tree-shaped structures.

• Journal of Electrical Engineering and Technology
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• 제13권4호
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• pp.1724-1731
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• 2018

The conventional polynomial neural network (PNN) is a classical flexible neural structure and self-organizing network, however it is not free from the limitation of overfitting problem. In this study, we propose a space search-optimized polynomial neural network (ssPNN) structure to alleviate this problem. Ranking selection is realized by means of ranking selection-based performance index (RS_PI) which is combined with conventional performance index (PI) and coefficients based performance index (CPI) (viz. the sum of squared coefficient). Unlike the conventional PNN, L2-norm regularization method for estimating the polynomial coefficients is also used when designing the ssPNN. Furthermore, space search optimization (SSO) is exploited here to optimize the parameters of ssPNN (viz. the number of input variables, which variables will be selected as input variables, and the type of polynomial). Experimental results show that the proposed ranking selection-based polynomial neural network gives rise to better performance in comparison with the neuron fuzzy models reported in the literatures.

• Journal of Korea Trade
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• 제25권4호
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• pp.1-16
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• 2021

Purpose - This study reviews changes in the steel export-import structure between Korea and Japan to strengthen the competitive advantage of the Korea Steel industry using a trade-related index. Design/methodology - This study focuses on analyzing comparative advantage based on the trade intensity index (TII), revealed comparative advantage index (RCA), and trade specialization index (TSI). Findings - Korea's steel import from Japan increased due to the domestic supply shortage of HR (Hot Rolled Coil) and Plate, rather than the sharp decline of the domestic steel industry's competitiveness in 2010. However, after the completion of Hyundai Steel's blast furnace, the Korea Steel industry solved the supply shortage. Additionally, the import of Japanese steel products had decreased significantly from 2009 to 2019. Originality/value - This study attempts to analyze Japanese steel products' competitiveness in trade and the domestic influence of high-quality Japanese steel products. These results are connected to domestic steel supply and demand structure and relations with the Japanese steel industry. After completing Hyundai Steel's blast furnace, the Korea Steel industry solved the supply shortage, and the import of Japanese steel products has decreased significantly from 2009 to 2019.

• Steel and Composite Structures
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• 제47권5호
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• pp.633-644
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• 2023

Taking a look at the previously published papers, it is revealed that there is a porosity index limitation (around 0.35) for the mechanical behavior analysis of the functionally graded porous (FGP) structures. Over mentioned magnitude of the porosity index, the elastic modulus falls below zero for some parts of the structure thickness. Therefore, the current paper is presented to analyze the vibrational behavior of the FGP Timoshenko beams (FGPTBs) using a novel refined formulation regardless of the porosity index magnitude. The silica aerogel foundation and various hydrothermal loadings are assumed as the source of external forces. To obtain the FGPTB's properties, the power law is hired, and employing Hamilton's principle in conjunction with Navier's solution method, the governing equations are extracted and solved. In the end, the impact of the various variables as different beam materials, elastic foundation parameters, and porosity index is captured and displayed. It is revealed that changing hygrothermal loading from non-linear toward uniform configuration results in non-dimensional frequency and stiffness pushing up. Also, Al - Al2O3 as the material composition of the beam and the porosity presence with the O pattern, provide more rigidity in comparison with using other materials and other types of porosity dispersion. The presented computational model in this paper hopes to help add more accuracy to the structures' analysis in high-tech industries.