• Journal of Food Hygiene and Safety
• /
• v.26 no.3
• /
• pp.273-282
• /
• 2011

This study established hazards which may cause risk to human at farm during cultivation stage of paprika. Samples of plants (paprika, leaf, stem), cultivation environments (water, soil), personal hygiene (hand, glove, clothes), work utensils (carpet, basket, box) and airborne bacteria were collected from three paprika farms (A, B, C) located in Western Gyeongnam, Korea. The collected samples were assessed for biological (sanitary indications and major foodborne pathogens), chemical (heavy metals, pesticide residues) and physical hazards. In biological hazards, total bacteria and coliform were detected at the levels of 1.9~6.6 and 0.0~4.610g CFU/g, leaf, mL, hand or 100 $cm^2$, while Escherichia coli was not detected in all samples. In major pathogens, only Bacillus cereus were detected at levels of ${\leq}$ 1.5 log CFU/g, mL, hand or 100 $cm^2$, while Staphylococuus aureus, Listeria monocytogenes, E. coli O157 and Salmonella spp. were not detected in all samples. Heavy metal and pesticide residue as chemical hazards were detected at levels below the regulation limit, physical hazard factors, such as insects, pieces of metal and glasses, were also found in paprika farms. Proper management is needed to prevent biological hazards due to cross-contamination while physical and chemical hazards were appropriate GAP criteria.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.29 no.5
• /
• pp.389-395
• /
• 2016

In this paper, vibration characteristics in terms of the airfoil cross-sectional shape was examined by using the EDISON co-rotational plane beam-transient analysis. Co-Rotational plane beam analysis is appropriate for large rotation and small strain. Assuming aircraft wing as a cantilevered beam, natural frequencies of each airfoil cross-sectional shape were estimated using VABS program and fast Fourier transformation(FFT). VABS conducts finite element analysis on the cross-section including the detailed geometry and material distribution to estimate the beam sectional properties. Under the same airfoil geometric configuration and material selection, variation of material induced difference in the deflection and natural frequencies. It was observed that variation of the natural frequency was dependent on variation of the airfoil shape and material.

• Research in Plant Disease
• /
• v.12 no.3
• /
• pp.278-283
• /
• 2006

The effect of calcium cyanamide($CaCN_2$) on suppression of clubroot of Chinese cabbage was evaluated in the fields infested with Plasmodiophora brassicae at National Institute of Highland Agriculture, Pyeongchang, Korea, from 2002 to 2003. Calcium cyanamide was found to be more effective in reducing disease severity than flusulfamide dust powder. The optimal dosage of calcium cyanamide for control of clubroot of Chinese cabbage was 61 kg/10a. When calcium cyanamide was incorporated into soil at 5, 10, 15 and 20 days before planting(DBP), maximum disease suppression was obtained in the plot with calcium cyanamide, applied 5DBP. The fertilizer property of calcium cyanamide as a nitrogen fertilizer was also investigated by comparing with urea on cv. CR Gangta, a resistant variety of Chinese cabbage. The nitrogen uptake in calcium cyanamide treatment(17.6 kg/10a), was not significantly different from that of urea(17.8 kg/10a). These results indicated that calcium cyanamide could be used as a soil disinfectant as well as a nitrogen fertilizer.

• Journal of Korean Society of Steel Construction
• /
• v.15 no.3
• /
• pp.291-298
• /
• 2003

Recently, as the size of buildings structure becomes large increases, their mat area of building structure is supported or by an inhomogeneous foundation. This paper presents a vibration analysis on thick plates subjected to in-plane force is presented in this paper. The rectangular plate is isotropic, homogeneous, and composed of a linearly elastic material. A vibration analysis of the rectangular thick plate iwas done by useing ofarectangular finite element with 8 nodes and 9 nodes. In this study, the foundation was idealized as a Pasternak foundation model. A Pasternak foundation haves a shear layer on Winkler's model, which idealizes the foundation as a vertical spring. In order tTo analysze the vibration of a plate supported on by an inhomogeneous Pasternak foundation, the value of the Winkler foundation parameter of the central and border zones of the plate awere chosen as WFP1 and WFP2. (fFigure 4.). The Winkler foundation parameter of WFP1 and WFP2 is varied from 0 to 10, $10^2$, and $10^3$ and the shear foundation parameters is were 0, 5, and 10. The ratio of the in-plane force to the critical load iwas applied as 0.4 to 0.8

• KSBB Journal
• /
• v.6 no.2
• /
• pp.167-174
• /
• 1991

Enzymatic cellulose hydrolysis depends on the several factors such as the structural features (CrI, particle size and surface area, etc.), the nature of cellulase enzyme system, the inhibitory effects of products, and enzyme deactivation. At the presence of products on the initial hydro- lysis rate of cellulose, cellobiose has more severe inhibitory effect than glucose. Othewise, the inhibition effect of products for adsorbed enzyme is related to the glucose and cellobiose conentration hyperbolically. Enzyme deactivation of FPA and ${\beta}-glucosidase$ were expressed by exponential decay profile.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.06a
• /
• pp.418-422
• /
• 2007

Ubiquitous Computing System란, 언제 어디서나 통신 및 컴퓨팅이 가능하고 컴퓨팅 시스템이 상호간에 정보를 공유하고 협력하는 컴퓨팅 시스템이다. 이로써 기존의 컴퓨팅 환경과 같이 사용자와 컴퓨터간의 대화형 상호작용이 아닌 물리적인 환경 상황(Context)등을 시스템이 스스로 인식하고 이를 기반으로 사용자와의 상호 작용을 지원하는 상황인식 기술이 필수적인 요소로 부각되고 있다. Ubiquitous Computing System을 위해 사용자 및 주변 환경의 정보를 감지하는 센서(Sensor) 기술이 필요하다. 하지만 사용자 및 주변 환경으로부터 입력되는 불확실하거나 모호한 상황정보에 대한 표현과 추론에 대한 연구는 부족한 실정이다. 본 논문은 Rule based System을 활용하여 CRS(Context Recognition Switch)라는 새로운 개념을 도입한 Context Aware Architecture를 제시한다. CRS는 유비쿼터스 컴퓨팅 시스템을 위해서는 센서로부터 복합적으로 인지된 사용자 정보 및 주변환경의 정보를 사용자로부터 수동적으로 설정되거나 System의 지속적으로 수집된 정보의 통계 값인 Reference Value와 비교하여, 각 상황에 따른 개별적이고 특화된 서비스를 실행을 하도록 제공한다. 이로써 같은 정보의 입력이 들어와도 그 주변 환경의 상황에 따라 사용자의 필요에 최적화된 실행을 할 수 있다. 마지막으로, Ubiquitous Computing System의 향후 발전 가능성을 예상해고, 본 논문에서 제시한 Context Aware Architecture의 유용성을 짐작해 본다.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.25 no.11
• /
• pp.1705-1712
• /
• 2001

Mechanical component has striation with constant width and SEM can estimate fracture type and loading condition. SEM has benefit to fatigue fracture analysis but striation can be observed according to the kind of material and range of crack growth rate and can't. In this case, it needs AFM that can measure 3-dimensional surface profile with resolution of atomic size. In this study. to find fracture reason of torsion-mounted blade in nuclear plant, we estimate the relation between stress intensity factor range and root mean square roughness in 12% Cr steel by AFM and predict in-service loading condition of turbine blade. failure analysis is performed by finite element method and Goodman diagram on torsion-mounted blade.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.27 no.12
• /
• pp.2019-2027
• /
• 2003

Pitting wear is a dominant from of polyethylene surface damage in total knee replacements, and may originate from surface cracks that propagate under repeated tribological contact. In this study, stress intensity factors, K$\_$I/and $_{4}$, were calculated for a surface crack in a polyethylene-CoCr-bone system under the rolling and/or sliding contact pressures. Crack length and load location were considered in determination of probable crack propagation mechanisms and fracture modes. Positive K$\_$I/ values were obtained for shorter cracks in rolling contact and for all crack lengths when the sliding load was apart from the crack. $_{4}$ was the greatest when the load was directly adjacent to the crack (g/a=${\pm}$1). Sliding friction caused a substantial increase of both K$\_$I/$\^$max/ and $_{4}$$\^$max/. The effective Mode I stress intensity factors, K$\_$eff/, were the greatest at g/a=${\pm}$1, showing the significance of high shear stresses generated by loads adjacent to surface cracks. Such behavior of K$\_$eff/ suggests mechanisms for surface pitting by which surface cracks may propagate along their original plane under repeated rolling or sliding contact.

• Journal of the Korean Society for Precision Engineering
• /
• v.32 no.3
• /
• pp.269-277
• /
• 2015

Compressed natural gas (CNG) composite vessels for vehicles have been generally made of 34CrMo4 for a inner liner part and E-glass/epoxy for a composite layer part. But, there is a problem of material loss of CNG composite vessels used in vehicles due to the design of excessive thickness of the liner. And, light weight of the CNG composite vessel is required for improving fuel efficiency. In this study, optimal design for CNG composite pressure vessel was performed by using basalt fiber, which is the environment-friendly material having a good mechanical strength. The optimal thickness of each part (inner liner and composite layer) was determined by theoretical analysis and FEA for satisfying structural safety and lightweight of the vessel. Also, for improving fatigue life, optimal autofrettage pressure was derived from FEA results.

• Journal of the Korea Society of Computer and Information
• /
• v.8 no.4
• /
• pp.176-185
• /
• 2003

The SCM is on the effective treatment solution that has process schedule, material supplying, inventory management for perfect product these days. The SCM is innovative process activity to attain effective whole. It depends on the structure of approach because supplying network is consist of organization, budgeting, responsibility and authority. The major objective of the thesis was to propose the integration model and structure method technique of the SCM. Thus, to implement strategy model, firstly, it is determined repairs and non-effectiveness of supplying network. secondly, to set up future vision and goal, it is considered success factor of supplying net. thirdly, no gaps introduce between present and future of supplying net fourthly as above-mentioned consequence, Alternative is to set up integration and implementing model according to enterprise administration strategy .