• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.4
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• pp.316-328
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• 2021

In this study, the leaf Na content prediction model for spring potato was established using 400-1000 nm hyperspectral sensor to develop the multispectral sensor for the salinity monitoring in reclaimed land. The irrigation conditions were standard, drought, and salinity (2, 4, 8 dS/m), and the irrigation amount was calculated based on the amount of evaporation. The leaves' Na contents were measured 1st and 2nd weeks after starting irrigation in the vegetative, tuber formative, and tuber growing periods, respectively. The reflectance of the leaves was converted from 5 nm to 10 nm, 25 nm, and 50 nm of FWHM (full width at half maximum) based on the 10 nm wavelength intervals. Using the variance importance in projections of partial least square regression(PLSR-VIP), ten band ratios were selected as the variables to predict salinity damage levels with Na content of spring potato leaves. The MLR(Multiple linear regression) models were estimated by removing the band ratios one by one in the order of the lowest weight among the ten band ratios. The performance of models was compared by not only R2, MAPE but also the number of band ratios, optimal FWHM to develop the compact multispectral sensor. It was an advantage to use 25 nm of FWHM to predict the amount of Na in leaves for spring potatoes during the 1st and 2nd weeks vegetative and tuber formative periods and 2 weeks tuber growing periods. The selected bandpass filters were 15 bands and mainly in red and red-edge regions such as 430/440, 490/500, 500/510, 550/560, 570/580, 590/600, 640/650, 650/660, 670/680, 680/690, 690/700, 700/710, 710/720, 720/730, 730/740 nm.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.19 no.3
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• pp.125-131
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• 2013

In order to protect agricultural products against damage by physical load, various shock absorbing materials is used. As the demands of environment protection increase, the use of plastic materials have been restricted. On the other hand, Pulp mold products have some benefits - easy manufacturing, superior shock absorbing and eco-friendly. In order to develop pulp mold tray for melon packaging as shock absorbing packaging material, we investigated physical properties and vibration transmission characters of 180, 200 and 220 g pulp mold tray for melon. As the weight of pulp increased, compression strength and shock absorbing performance increased, while vibration transmissibility decreased. Especially in case of 180g pulp mold tray, it is not suitable for melon packaging because the transmitted vibration acceleration was higher than the forced vibration acceleration. And 200g pulp mold tray is suitable for melon packaging because the vibration transmissibility was lowest in three trays. And the vibration acceleration transmitted to the melon in edge of pulp mold tray was higher than to the melon in center of pulp mold tray. As the result of the simulated transportation test, the firmness of melon packaging using pulp mold tray was higher than that of conventional packaging. Therefore, these results suggest that pulp mold tray packaging could be suitable for melon packaging.

• Journal of the Korean Institute of Gas
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• v.18 no.6
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• pp.27-31
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• 2014

This paper presents a study on the strength safety of the weak parts at Part 1, Part 2 and Part 3 in the valve structure for LPG cylinder by using the finite element method. The maximum Von Mises stress of 27.5MPa was occurred at the corner edge of a valve Part 1 for the valve thickness of 1.5mm and LPG pressure of 3.5MPa. And the maximum Von Mises stresses for the valve thickness of 1.5mm and LPG pressure of 3.5MPa were 41.5MPa at Part 2 and 46.5MPa at Part 3. The FEM computed results show that the maximum Von Mises stresses at Part 1, Part 2 and Part 3 are very low value of 9.2~15.5% compared with the yield strength of a copper alloy, C3604. This means that the valve thickness for LPG cylinder is so over designed for the conventional valve. Thus, this paper recommends that the thickness at Part 1 and Part 2 is reduced for a light weight of a copper valve. But, the thickness at Part 3 may be better for a thick valve as a conventional valve for high torque strength.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.235-243
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• 2002

Ni-base superalloys are used extensively in industry, both in aeroengines and land based turbines. About 60% by weight of most modern gas turbine engine structural components are made of Ni-base superalloys. To satisfy practical demands, the efficiency of gas turbine engines has been steadily and systematically increased by design modifications to handle higher turbine inlet or firing temperatures. However, the increase in operating temperatures has lead to a decrease in the life of components and increase in costs of replacement. Moreover, around 80% of the large frame size industrial/utility gas turbines operating in the world today were installed in the mid-sixties to early seventies and are now 25 to 30 years old. Consequently, there are greater opportunities now to repair and refurbish the older models. Basically, there are two major factors influencing the weldability of the cast alloys: strain-age cracking and liquation cracking. Susceptibility to strain-age cracking is due to the total Ti plus AI content of the alloy; Liquation cracking is due either to the presence of low melting constituents or constitutional liquation of constituents. Though Rene 41 superalloy has 4.5wt.% total Ti and Al content and falls just below the safe limit proposed by Prager et al., controlled grain size and special heat treatments are needed to obtain crack-free welds. Varying heat treatments and filler materials were used in a laboratory study, then the actual welding of service parts was carried out to verity the possibility of crack-tree weld of components fabricated from Rene 41 superalloy. The microstructural observations indicated that there were two kinds of carbides in the FCC matrix. MC carbides were located along the grain boundaries, while M$_{23}$C$_{6}$ carbide was located both inter and intra granularly. Two kinds of filler materials, Rene 41 and Hastelloy X were used to gas tungsten arc weld a patch into the sheet metal, along with varying pre-weld heat treatments. The microstructure, hardness and tensile tests were determined. The service distressed parts were categorized into three classes: with large cracks, with medium cracks and with small or no visible cracks. No significant difference in microstructure among the specimens was observed. Specimens were cut from the corner and the straight edge of the patch repair, away from the corner. The only cracks present were found to be associated with inadequate surface preparation to remove oxidation. Guidelines for oxide removal and the welding procedures developed in the research enabled crack-free welds to be produced.d.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.1
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• pp.17-25
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• 2007

In most electronic imaging applications, image with high resolution(HR) are desired. HR means that pixel density within an image is high, and therefore HR image can offer more details that may be critical in various applications. Digital images that are captured by CCD and CMOS cameras usually have a very low resolution, which significantly limits the performance of image recognition systems. Image super-resolution techniques can be applied to overcome the limits of these imaging systems. Super-resolution techniques have been proposed to increase the resolution by combining information from multiple images. To techniques were consisted of the registration algorithm for estimation and shift, the nearest neighbor interpolation using weight of acquired frames and presented frames. In this paper, it is proposed the image interpolation techniques using the wavelet base function. This is applied to embody a correct edge image and natural image when expend part of the still image by applying the wavelet base function coefficient to the conventional Super-Resolution interpolation method. And the proposal algorithm in this paper is confirmed to improve the image applying the nearest neighbor interpolation algorithm, bilinear interpolation algorithm.,bicubic interpolation algorithm through the computer simulation.

• Advances in pediatric surgery
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• v.12 no.2
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• pp.167-174
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• 2006

Central venous catheter (CVC) for long-term venous access is indispensable for various reasons including hyperalimentation, frequent blood sampling, frequent IV drug use in pediatric patients. We report clinical experience of surgical neonates in whom CVC was inserted primarily via great saphenous vein into suprarenal inferior vena cava. From March 2004 to March 2006, we performed CVC insertion via saphenous vein - contralateral side to main wound - into suprarenal inferior vena cava in surgeries of neonates. 2.7Fr or 4.2Fr, single lumen, tunneled Broviac catheters (Bard Access system, Inc, Salt Lake City, Utah) were used. Skin exit site of tunneled catheter was located in ipsilateral flank area just below edge lower rib. At the end of the procedure, location of the catheter tip was confirmed by plain radiography of abdomen. We retrospectively reviewed the admission records of the patients including nursing staff charts. Nine (50.0 %) patients were male and nine (50.0%) were female. Median gestational age was 38 weeks (range, 29-42 weeks) and median birth weight was 3,105 gm (range, 1,040-3,720 gm). Median age at catheter insertion was 38.5 days (range, 1-236 days). The purpose of CVC insertion was short-and long-term hyperalimentation in nine (50.0 %) patients. CVC insertion was performed in operation room under general anesthesia in sixteen (88.9 %) patients (in these cases, CVC insertion was performed just prior to concurrent operation) and neonatal intensive care unit (NICU) under local anesthesia with adequate sedation in two (11.2%). During the admission period (total catheter-indwelling time: 553 days), CVC functioned well without any significant side effects. Transient swelling of the ipsilateral leg (n=1, 5.6 %) and transient migration of catheter tip (n=1, 5.6 %) were noted, which did not affect function of the indwelled CVC. Mean catheter-indwelling time was 30.7days (range, 3-72 days). All catheters were removed electively except two mortality case. Complications, such as thrombosis, infection, kinking or extravasation of drugs, were not observed in our study period. Tunneled trans-great saphenous vein inferior vena cava catheters are not only comparable to cervical CVCs in terms of function and complication rates, but also very beneficial in selected patients, especially those in whom cervical approach is technically impossible or contraindicated.

• International Journal of Highway Engineering
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• v.19 no.6
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• pp.67-74
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• 2017

PURPOSES : In this study, a three-dimensional nonlinear finite element analysis (FEA) model for airport concrete pavement was developed using the commercial program ABAQUS. Users can select an analysis method and set the range of input parameters to reflect actual conditions such as environmental loading. METHODS : The geometrical shape of the FEA model was chosen by considering the concrete pavement located in the third-stage construction site of Incheon International Airport. Incompatible eight-node elements were used for the FEA model. Laboratory test results for the concrete specimens fabricated at the construction site were used as material properties of the concrete slab. The material properties of the cement-treated base suggested by the Federal Aviation Administration(FAA) manual were used as those of the lean concrete subbase. In addition, preceding studies and pavement evaluation reports of Incheon International Airport were referred for the material properties of asphalt base and subgrade. The kinetic friction coefficient between the concrete slab and asphalt base acquired from a preceding study was used for the friction coefficient between the layers. A nonlinear temperature gradient according to slab depth was used as an input parameter of environmental loading, and a quasistatic method was used to analyze traffic loading. The average load transfer efficiency obtained from an Heavy falling Weight Deflectomete(HWD) test was converted to a spring constant between adjacent slabs to be used as an input parameter. The reliability of the FEA model developed in this study was verified by comparing its analysis results to those of the FEAFAA model. RESULTS : A series of analyses were performed for environmental loading, traffic loading, and combined loading by using both the model developed in this study and the FEAFAA model under the same conditions. The stresses of the concrete slab obtained by both analysis models were almost the same. An HWD test was simulated and analyzed using the FEA model developed in this study. As a result, the actual deflections at the center, mid-edge, and corner of the slab caused by the HWD loading were similar to those obtained by the analysis. CONCLUSIONS : The FEA model developed in this study was judged to be utilized sufficiently in the prediction of behavior of airport concrete pavement.

• Journal of Korean Society of Steel Construction
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• v.19 no.3
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• pp.303-312
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• 2007

Steel box girder bridges are being commonly designed for medium-span bridges of span length. Composite truss bridges with steel diagonals instead of concrete webs can be an excellent design alternative, because it can reduce the dead weight of superstructures. One of the key issues in the design of composite truss bridges is the joint structureconnecting the diagonal steel members with the upper and lower concrete slabs. Because the connection has to carry concentrated combined loads and the design provisions for the joint are not clear, it is necessary to investigate the load transfer mechanism and the design methods for each limit state. There are various connection details according to the types of diagonal members. In this paper, the joint structure with group stud connectors welded on a gusset plate is used. Push-out tests for the group stud connectors of were performed. The test results showed that the current design codes on the ultimate strength ofthe stud connection can be used when the required minimum spacing of stud connectors is satisfied. Flexure-shear tests were conducted to verify the applicability of the design provisions for combined load effects to the strength of joint structures. To increase the pullout strength of the connection, bent studs were proposed and utilized for the edge studs in the group arrangement of the joint. The results showed that the details of the joint structure were enhanced. Thereafter, design guidelines were proposed.

• The Korean Journal of Mycology
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• v.40 no.3
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• pp.145-151
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• 2012

Two strains Pleurotus eryngii KNR2312 and A8B10 (Na) which have good traits in cap quality and speedy growing were selected to breed a new strain carrying the two traits. KNR2312-2636-$10{\times}18$ (Ga) with 45.2 cap lightness and 6.5 quality was breeded by a consecutive inbreeding between KNR2312-derived monokaryons. $Ga5{\times}Na5$ came from outcrossing between Ga and Na was backcrossed with KNR2312-derived monokaryons twice to improve quality in cap color and shape. Therethrough Ga5NaKNR2312-47KNR2312-$12{\times}38$ carrying lightness of 49.5, quality of 7.3 and weight of 95.1 g was selected. The selected strain possesses good quality and dark color of cap. Especially its edge is 24 mm thick, therefore it is not likely damaged during processing and distribution.

• Journal of the Korean Society for Railway
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• v.17 no.2
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• pp.94-99
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• 2014

Recently, trends in new transportation system development have been primarily focused on sustainable and ecofriendly mobility solutions. The personal rapid transit (PRT) system has been considered a promising candidate in this category; its competitiveness is being improved through convergence with cutting-edge electric vehicle (EV) technologies. However, battery-powered vehicles pose difficult technical challenges in attempts to achieve reliable and efficient operation. In this study, a design approach for a solar-power assisted PRT system is presented with small-scale demonstrations aimed at circumventing challenges facing its adoption, as well as helping speed the transition to electric-powered ground transportation. From the results, it is expected that flexible photovoltaic (PV) cells will be able to supply 11% of the power required by the service equipment installed in a prototype vehicle. In particular, flexible photovoltaic (PV) cells are advantageous in terms of cost, weight, and design considerations. Most importantly, the cells' flexibility and attach-ability are expected to give them great potential for extended application in various areas.