• 수산해양교육연구
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• 제28권3호
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• pp.713-726
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• 2016

This study were attempted to apply the HACCP system adopted in the dried anchovy workplace to ensure the hygiene safety of dried anchovy workplace. In this study, HACCP system procedures, including HACCP team organization, determination of critical control point(CCP), establishment of critical limits, mornitering and verification etc., were established using KFDA 12 procedures. To determine whether hazards were critical elements, we evaluated the likelihood and seriousness of each hazard element. The likelihood of residual microorganism and metal piece exceeding the acceptable limit in dried anchovy products were demonstrated to be a critical hazard element. Management of the boiling(CCP-1B) and metal detection(CCP-2P) were determined to be a critical control point. The standards for acceptable residual microorganism and metal piece were set based on relevant laws and regulations, and then the limits were adapted and established for the CCP. An HACCP plan applicable to dried anchovy workplace was established.

• 소성∙가공
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• 제24권6호
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• pp.395-399
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• 2015

A microstructure-based finite element simulation was conducted to predict the plastic strain ratio (R-value) of a dual-phase (DP) steel. The representative volume elements (RVEs) concept was adopted for the image-based FE modeling and a 3D model was constructed using sequential 2D images. Each phase was considered with the von-Mises yield criterion and the Swift model. The Swift parameters were defined by the empirical equations based on the chemical composition. The developed model was applied to analyze the effect of residual stress on the R-value and stress distribution. In order to consider the residual stress development after cold rolling, 10 % compression was applied in the thickness direction and unloaded before the tensile stress was applied in the rolling direction. The results showed a reasonable prediction for the R-value evolution: a sharp increase at small strains was well described and a transition followed in the downward direction. The R-value evolution was analyzed using the stress distribution change on the π-plane

• 한국강구조학회 논문집
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• 제18권6호
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• pp.687-696
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• 2006

본 논문에서는 공간 뼈대구조의 탄-소성 후좌굴 강도를 파악하기 위한 효율적인 수치해석 기법을 개발하고, 매개변수해석을 통하여 보-기둥 및 뼈대구조물의 비탄성 후좌굴 거동을 분석하였다. 외력의 증가에 따라 점진적인 강도감소효과를 효율적으로 고려하는 개선된 소성힌지 해석법을 적용하여 문헌에서 제시된 다양한 잔류응력 분포 형태에 따른 뼈대구조물의 탄-소성 해석을 수행하였다. 요소의 소성화 진행정도를 나타내는 파라미터들을 도입하고 등가단면력 및 요소분할에 따른 매개변수해석을 수행하여 그 결과를 문헌에서 제시된 소성영역해석, 쉘요소를 이용한 정밀해석 그리고 실험결과와 비교하여 뼈대구조물 극한강도를 평가하였다.

• International journal of advanced smart convergence
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• 제9권2호
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• pp.185-194
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• 2020

Designing of a hierarchical clustering algorithm is one of the numerous approaches to minimize the energy consumption of the Wireless Sensor Networks (WSNs). In this paper, a homogeneous and randomly deployed sensor nodes is considered. These sensors are energy constrained elements. The nominal selection of the Cluster Head (CH) which falls under the clustering part of the network protocol is studied and compared to Low Energy Adaptive Clustering Hierarchy (LEACH) protocol. CHs in this proposed process is the function of total remaining energy of each node as well as total average energy of the whole arrangement. The algorithm considers initial energy, optimum value of cluster heads to elect the next group of cluster heads for the network as well as residual energy. Total remaining energy of each node is compared to total average energy of the system and if the result is positive, these nodes are eligible to become CH in the very next round. Analysis and numerical simulations quantify the efficiency and Average Energy Ratio (AER) of the proposed system.

• 한국전산구조공학회논문집
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• 제19권4호
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• pp.347-356
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• 2006

본 논문에서는 단면상의 화이버 요소를 사용하여 3차원 강구조물의 점진적인 소성화를 고려하는 실용적인 비선형 비탄성 해석방법을 개발하였다. 부재의 p-$\delta$, p-$\Delta$ 등의 기하비선형은 안정함수로 고려하였다. 잔류응력은 단면상에 있는 화이버 요소에 초기응력을 가하여 고려하였다. 각 하중 단계에서 탄성상태인 단면을 계산하여 축강성과 휨강성을 직접 결정함으로서 점진적인 소성화를 고려하였다. 각 화이버 요소의 응력 변화를 계산하여 변형률 반전효과를 고려하였다. 제안된 해석 방법은 3차원 강구조물의 실용적인 해석 및 설계에 유용하게 사용될 것이라 판단한다.

• 동굴
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• 제92호
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• pp.9-18
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• 2009

A number of closed metal mines act as point sources of contamination on nearby streams, soils and plants in our country. The contamination of twelve decomposed samples had earned from nine closed metal mines had been evaluated by TEA-3000. The contents of heavy metal with ion fraction exchange and carbonate fraction forms had been showed that the speciation of heavy metals represented with easy solubility, mobility and bioavailable of plants, and in case of sulfide compounds and organic residuals forms are related with the speciation of metals which may be stable forms because of strong bindable capacity. Also heavy metals elements in mosts of mines got with relative stable within crystal lattice, but results of trace element analyser showed that, in the most of tailings from mine areas, large portions of concentration of heavy metals were explained as stable from, sulfides/ organics and residual. In tailing from Imchun mines, the concentrations extracted by water were relatively high as compared with other mine areas whose total concentrations were very high because of large quantities of exchangeable ions and carbonates and low soil pH. Danger Index (D.I.) suggested in this study was based on the cumulative concentrations of step 1 and 2 from the result of trace element analyser. When the soil pH was considered, this index became better indicator to determine the priority for the remediation of mine area.

• Smart Structures and Systems
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• 제7권5호
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• pp.329-348
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• 2011

Large-scale earthquakes pose serious threats to infrastructure causing substantial damage and large residual deformations. Superelastic (SE) Shape-Memory-Alloys (SMAs) are unique alloys with the ability to undergo large deformations, but can recover its original shape upon stress removal. The purpose of this research is to exploit this characteristic of SMAs such that concrete Beam-Column Joints (BCJs) reinforced with SMA bars at the plastic hinge region experience reduced residual deformation at the end of earthquakes. Another objective is to evaluate the seismic performance of SMA Reinforced Concrete BCJs repaired with flowable Structural-Repair-Concrete (SRC). A $\frac{3}{4}$-scale BCJ reinforced with SMA rebars in the plastic-hinge zone was tested under reversed cyclic loading, and subsequently repaired and retested. The joint was selected from an RC building located in the seismic region of western Canada. It was designed and detailed according to the NBCC 2005 and CSA A23.3-04 recommendations. The behaviour under reversed cyclic loading of the original and repaired joints, their load-storey drift, and energy dissipation ability were compared. The results demonstrate that SMA-RC BCJs are able to recover nearly all of their post-yield deformation, requiring a minimum amount of repair, even after a large earthquake, proving to be smart structural elements. It was also shown that the use of SRC to repair damaged BCJs can restore its full capacity.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권6호
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• pp.1818-1832
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• 2022

Violence in the Internet era poses a new challenge to the current counter-riot work, and according to research and analysis, most of the violent incidents occurring are related to the dissemination of violence images. The use of the popular deep learning neural network to automatically analyze the massive amount of images on the Internet has become one of the important tools in the current counter-violence work. This paper focuses on the use of transfer learning techniques and the introduction of an attention mechanism to the residual network (ResNet) model for the classification and identification of violence images. Firstly, the feature elements of the violence images are identified and a targeted dataset is constructed; secondly, due to the small number of positive samples of violence images, pre-training and attention mechanisms are introduced to suggest improvements to the traditional residual network; finally, the improved model is trained and tested on the constructed dedicated dataset. The research results show that the improved network model can quickly and accurately identify violence images with an average accuracy rate of 92.20%, thus effectively reducing the cost of manual identification and providing decision support for combating rebel organization activities.

• Steel and Composite Structures
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• 제45권5호
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• pp.683-695
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• 2022

Conventional braces are often used to provide stiffness to structures; however due to buckling they cannot be used as seismic energy dissipating elements. In this study, a seismic energy dissipation device is proposed which is comprised of a bracing member and a steel hysteretic damper made of steel hexagonal plates. The hexagonal shaped designated fuse causes formation of plastic hinges under axial deformation of the brace. The main advantages of this damper compared to conventional metallic dampers and buckling-restrained braces are the stable and controlled energy dissipation capability with ease of manufacture. The mechanical behavior of the damper is formulated first and a design procedure is provided. Next, the theoretical formulation and the efficiency of the damper are verified using finite element (FE) analyses. An analytical model of the damper is established and its efficiency is further investigated by applying it to seismic retrofit of a case study structure. The seismic performance of the structure is evaluated before and after retrofit in terms of maximum interstory drift ratio, top story displacement, residual displacement, and energy dissipation of dampers. Overall, the median of maximum interstory drift ratios is reduced from 3.8% to 1.6% and the residual displacement decreased in the x-direction which corresponds to the predominant mode shape of the structure. The analysis results show that the developed damper can provide cost-effective seismic protection of structures.

• 한국광학회지
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• 제11권4호
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• pp.239-245
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• 2000

본 논문에서는 회절광학소자를 이용하여 컴팩트형 디지털 스틸 카메라용 광학계를 설계 및 평가하였다. 기존의 디지털 스틸 카메라용 광학계가 retrofocus 형태인 것에 비해 컴팩트한 광학계를 얻기 위해서 telephoto 형태로 구성하였다. 또한, 본 광학계를 회절광학소자와 굴절광학소자가 결합된 hybrid 플라스틱 렌즈 1매와 순수한 굴절광학소자 1매로 구성하여 무게, 부피등을 줄이고자 하였다. Gauss 괄호를 이용한 근축 광선추적을 통해 초기 설계치를 수치 해석적인 방법으로 구하였다. 제1면을 비구면화하고, 색수차를 보정하기 위해 제2면을 회절광학소자를 이용하여 설계된 광학계는 1/4" CCD, F/4에 대응되도록 최적화하였다. 최종적으로 설계된 광학계의 초점거리는 3.89mm, 전장(overall length)은 5.19mm로서 컴팩트하며, 현재의 디지털스틸 카메라용 광학계에서 요구하는 성능을 충분히 만족하며, 차세대 화상통신용 광학계에 응용될 수 있을것으로 기대된다.