• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.4
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• pp.309-316
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• 2017

In this paper, numerical modeling is conducted to analyze the tension of an anchor line by varying the size and drag coefficient of a buoy when the trapnet is influenced by the wave and the current simultaneously. A mass-spring model was used to analyze the behavior of trapnet underwater under the influence of waves and current. In the simulation of numerical model, wave height of 3, 4, 5 and 6 m, a period of 4.4 s, and the flow speed of 0.7 m/s were used for the wave and current condition. The drag coefficients of buoy were 0.8, 0.4 and 0.2, respectively. The size of buoy was 100, 50 and 25% based on the cylindrical buoy ($0.0311m^3$) used for swimming crab trap. The drag coefficient of the trapnet, the main model for numerical analysis, was obtained by a circular water channel experiment using a 6-component load cell. As a result of the simulation, the tension of the anchor line decreased proportional to buoy's drag coefficient and size; the higher the wave height, the greater the decrease rate of the tension. When the buoy drag coefficient and size decreased to one fourth, the tension of the anchor line decreased to a half and the tension of the anchor line was lower than the holding power of the anchor even at 6 m of wave height. Therefore, reducing the buoy drag coefficient and size appropriately reduces the trapnet load from the wave, which also reduces the possibility of trapnet loss.

• Korean journal of applied entomology
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• v.30 no.2
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• pp.124-129
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• 1991

This study investigated seasonal occurrence and daily flight activity using synthetic sex pherom mone and injury characteristics of 야et armyworm, Spodoptera exigua in Chonnam area of K Korea in 1990. Male adults were attracted to phermone trap from mid-June to late November w with the peaks at mid-late August, mid-late September and early-mid November in vinyl i house and also were attracted from mid October to late November in field. Primary peak of occurrence in vinyl house was 20 days sooner than field. It seems to have 6 generations a year in C Chonnam region based on the estimation of larval biomass. Daily male flight was active from m midnight to before sunrise with the peak at 4-6 A.M .. In injury characteristics at various host plants, damage was great in early growing stage at below 10 cm of plant height in Allium fistulsum. Chrysanthemum morifolium was damaged at mostly upper part of leaves reaching to m the extent up to 70%. In case of Gypsophila paniculata, plants injured at early growing stage do n not grow and flower normally.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.118-118
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• 2011

The Nano-Floating Gate Memory(NFGM) devices with ZnO:Cu thin film embedded in Al2O3 and AlOx-SAOL were fabricated and the electrical characteristics were evaluated. To further improve the scaling and to increase the program/erase speed, the high-k dielectric with a large barrier height such as Al2O3 can also act alternatively as a blocking layer for high-speed flash memory device application. The Al2O3 layer and AlOx-SAOL were deposited by MLD system and ZnO:Cu films were deposited by ALD system. The tunneling layer which is consisted of AlOx-SAOL were sequentially deposited at $100^{\circ}C$. The floating gate is consisted of ZnO films, which are doped with copper. The floating gate of ZnO:Cu films was used for charge trap. The same as tunneling layer, floating gate were sequentially deposited at $100^{\circ}C$. By using ALD process, we could control the proportion of Cu doping in charge trap layer and observe the memory characteristic of Cu doping ratio. Also, we could control and observe the memory property which is followed by tunneling layer thickness. The thickness of ZnO:Cu films was measured by Transmission Electron Microscopy. XPS analysis was performed to determine the composition of the ZnO:Cu film deposited by ALD process. A significant threshold voltage shift of fabricated floating gate memory devices was obtained due to the charging effects of ZnO:Cu films and the memory windows was about 13V. The feasibility of ZnO:Cu films deposited between Al2O3 and AlOx-SAOL for NFGM device application was also showed. We applied our ZnO:Cu memory to thin film transistor and evaluate the electrical property. The structure of our memory thin film transistor is consisted of all organic-inorganic hybrid structure. Then, we expect that our film could be applied to high-performance flexible device.----못찾겠음......

• Korean Journal of Materials Research
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• v.27 no.1
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• pp.48-52
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• 2017

In this study, we used I-V spectroscopy, photoconductivity (PC) yield and internal photoemission (IPE) yield using IPE spectroscopy to characterize the Schottky barrier heights (SBH) at insulator-semiconductor interfaces of Pt/$HfO_2$/p-type Si metal-insulator-semiconductor (MIS) capacitors. The leakage current characteristics of the MIS capacitor were analyzed according to the J-V and C-V curves. The leakage current behavior of the capacitors, which depends on the applied electric field, can be described using the Poole-Frenkel (P-F) emission, trap assisted tunneling (TAT), and direct tunneling (DT) models. The leakage current transport mechanism is controlled by the trap level energy depth of $HfO_2$. In order to further study the SBH and the electronic tunneling mechanism, the internal photoemission (IPE) yield was measured and analyzed. We obtained the SBH values of the Pt/$HfO_2$/p-type Si for use in Fowler plots in the square and cubic root IPE yield spectra curves. At the Pt/$HfO_2$/p-type Si interface, the SBH difference, which depends on the electrical potential, is related to (1) the work function (WF) difference and between the Pt and p-type Si and (2) the sub-gap defect state features (density and energy) in the given dielectric.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.1
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• pp.33-38
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• 2003

Turbidity meter calibrations were conducted using bottom sediment and suspended material collected with a vertical array of sediment traps at the coastal water off Gaduk Island. Compared to the bottom sediment comprising sand fraction of approximately 6％, trapped suspended material was composed entirely of silt and clay fractions and showed a tendency to get finer as elevation from the sea-bed increases. Slope parameter of linear regression due to bottom sediment was of minimum value and values of those due to suspended material increased gradually as the height of sediment trap increases (i.e., sediment size decreases). This result shows that turbidity meter calibration using bottom sediment can cause an overestimation error in the calculation of suspended sediment concentration and that the error can reach up to 25% in case of this study. Therefore, it is suggested that the use of a corrected calibration curve based on grain size distribution of suspended material instead of bottom sediment may reduce the measurement error of suspended sediment concentration.

• Journal of Periodontal and Implant Science
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• v.36 no.2
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• pp.345-359
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• 2006

Loss of maxillary molar teeth leads to rapid loss of crestal bone and inferior expansion of the maxillary sinus floor (secondary pneumatization). Rehabilitation of the site with osseointegrated dental implants often represents a clinical challenge because of the insufficient bone volume resulted from this phenomenon. Boyne & James proposed the classic procedure for maxillary sinus floor elevation entails preparation of a trap door including the Schneiderian membrane in the lateral sinus wall. Summers proposed another non-invasive method using a set of osteotome and the osteotome sinus floor elevation (OSFE) was proposed for implant sites with at least 5-6mm of bone between the alveolar crest and the maxillary sinus floor. The change of grafted material in maxillary sinus is important for implant survival and the evaluation of graft height after maxillary sinus floor elevation is composed of histologic evaluation and radiomorphometric evaluation. The aim of the present study was radiographically evaluate the graft height change after maxillary sinus floor elevation and the influence of the graft material type in height change and the bone remodeling of grafts in sinus. A total of 59 patients (28 in lateral approach and 31 in crestal approach) who underwent maxillary sinus floor elevation composed of lateral approach and crestal approach were radiographically followed for up to about 48 months. Change in sinusgraft height were calculated with respect to implant length (IL) and grafted sinus height(BL). It was evaluated the change of the graft height according to time, the influence of the approach technique (staged approach and simultaneous approach) in lateral approach to change of the graft height, and the influence of the type of graft materials to change of the graft height. Patients were divided into three class based on the height of the grafted sinus floor relative to the implant apex and evaluated the proportion change of that class (Class I, in which the grafted sinus floor was above the implant apex; Class II, in which the implant apex was level with the grafted sinus floor; and Class III, in which the grafted sinus floor was below the implant apex). And it was evaluated th bone remodeling in sinus during 12 months using SGRl(by $Br\ddot{a}gger$ et al). The result was like that; Sinus graft height decreased significantly in both lateral approach and crestal approach in first 12 months (p$MBCP^{TM}$ had minimum height loss. Class III and Class II was increased by time in both lateral and crestal approach and Class I was decreased by time. SGRI was increased statistically significantly from baseline to 3 months and 3 months(p<0.05) to 12 months(p$ICB^{(R)}$ single use, more reduction of sinusgraft height was appeared. Therefore we speculated that the mixture of graft materials is preferable as a reduction of graft materials. Increasing of the SGRI as time goes by explains the stability of implant, but additional histologic or computed tomographic study will be needed for accurate conclusion. From the radiographic evaluation, we come to know that placement of dental implant with sinus floor elevation is an effective procedure in atrophic maxillary reconstruction.

• Journal of the Korean Vacuum Society
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• v.16 no.3
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• pp.197-204
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• 2007

Ultra thin Er-silicide layers formed by Er deposition on the clean p-silicon and in situ post annealing technique were investigated with respect to change of the Schottky barrier height. The formation of Er silicides was confirmed by XPS results. UPS measurements revealed that the workfunction of the silicide decreased and was saturated as the deposited Er thickness increased up to $10{\AA}$. We found that the silicides were mainly composed of Er5Si3 phase through the XRD experiments. After Schottky diodes were fabricated with the Er silicide/p-Si junctions, the Schottky barrier heights were calculated $0.44{\sim}0.78eV$ from the I-V measurements of the Schottky diodes. There was large discrepancy in the Schottky barrier heights deduced from the UPS with the ideal junction condition and the real I-V measurements, so that we attributed the discrepancy to the $Er_5Si_3$ phase in the Er-silicides and the large interfacial density of trap state of it.

• Korean journal of applied entomology
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• v.45 no.1 s.142
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• pp.37-43
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• 2006

Catch of garden thrips, Frankliniella intonsa, on sticky traps was assessed by color and height in commercial plastic vinyl house strawberry crops grown on 40-cm-high trellises. Yellow, blue and white sticky cards were tested for color attractiveness, and upper (50 cm), lower (10 cm above the floor) and ground were for height. At each height, trapped thrips on yellow, blue and white were significantly different. Blue sticky cards were significantly greater than traps on yellow and white. The trapped thrips were also significantly greatest at 50 cm above the floor, less at lower and ground. However, there is no significantly different the population of garden thrips on the flower in each tested site.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.2
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• pp.85-90
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• 2012

In this paper, we compared and analyzed 3D silicon-oxide-nitride-oxide-silicon (SONOS) multi layer flash memory devices fabricated on nitride or oxide layer, respectively. The device fabricated on nitride layer has inferior electrical properties than that fabricated on oxide layer. However, the device on nitride layer has faster program / erase speed (P/E speed) than that on the oxide layer, although having inferior electrical performance. Afterwards, to find out the reason why the device on nitride has faster P/E speed, 1/f noise analysis of both devices is investigated. From gate bias dependance, both devices follow the mobility fluctuation model which results from the lattice scattering and defects in the channel layer. In addition, the device on nitride with better memory characteristics has higher normalized drain current noise power spectral density ($S_{ID}/I^2_D$>), which means that it has more traps and defects in the channel layer. The apparent hooge's noise parameter (${\alpha}_{app}$) to represent the grain boundary trap density and the height of grain boundary potential barrier is considered. The device on nitride has higher ${\alpha}_{app}$ values, which can be explained due to more grain boundary traps. Therefore, the reason why the devices on nitride and oxide have a different P/E speed can be explained due to the trapping/de-trapping of free carriers into more grain boundary trap sites in channel layer.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.77-83
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• 2022

This study was conducted to determine the optimal composition of sex attractant for monitoring adults of the tobacco cutworm, Spodoptera litura, in Korea. Lures of different compositions from the two sex pheromone components the female, (Z,E)-9,11-tetradecadienyl acetate (Z9E11-14:Ac) and (Z,E)-9,12-tetradecadienyl acetate (Z9E12-14:Ac), were compared for male attraction using synthetic chemicals, rubber septa, and funnel traps in soybean and peanut fields. After sequential tests were conducted using three sets of the two components different ranges from 5:5 to 10:1, from 9:1 to 99:1, and from 9:1 to 39:1, the 19:1 ratio was identified as the most efficient composition. However, S. litura males were barely caught in the trap of the Z9E11-14Ac single component lure. The results show that both the sex attractant compounds are necessary for monitoring adults S. litura males. The higher the pheromone amount in the dispenser in the range from 0.1 to 10 mg, the more males were attracted. Furthermore, the trap height of 1.5 m was optimal for male capture.