• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.12
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• pp.11-17
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• 2000

We investigated the growth of InGaN/GaN multiple quantum wells (MQWs) structures which emit blue light. The samples were grown in a low pressure metalorganic chemical vapor deposition system. We examined InGaN/GaN MQWs by varying growth temperatures and thicknesses of InGaN well and GaN barrier layers in MQWs. Especially, the thickness of GaN barrier in InGaN/GaN MQWs was found to severely affect the interfacial abruptness between InGaN well and GaN barrier layers. The higher order satellite peaks in the high resolution x-ray diffraction spectra and the high resolution cross sectional transmission electron microscope image of MQW structrues revealed that the interface between InGaN and GaN layers was very abrupt. Room-temperature photoluminescence spectra also showed a blue emission from InGaN/GaN MQWs at the wavelength of 463.5nm with a narrow full width at half maximum of 72.6meV.

• Journal of Digital Convergence
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• v.14 no.5
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• pp.227-236
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• 2016

Co-creation is an important approach to innovation that uses internal and external sources for value creation. This study identified the effects of intrinsic motivation, extrinsic motivation, and the moderating effects of activation factors using multiple regression and moderated multiple regression. To this end, 181 usable questionnaires were collected and analyzed. The result of analysis showed that intrinsic motivation had the significant meaning and the moderating effects of activation factors on the relationship between extrinsic motivation and co-creation participation exist. Companies may use this result to activate the co-creation participation of the customer. The future study analyzed by survey responses in multiple layers will improve the generalization of the study.

• Korean Journal of Optics and Photonics
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• v.14 no.5
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• pp.555-564
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• 2003

WDM thin film filters for fiber optical communication were designed using Fabry-Prot type multiple cavity filters and an equivalent thin film technique. As the number of cavities in multiple cavity filters increases, it becomes difficult to design the filters due to a great number of variables (the number of cavities, period of reflectors, order of spacers). To solve the problem of design, we treated the fewest variables, regarding symmetrical thin films as equivalent layers, and we applied structural and numerical formulas based on an analysis method of multiple cavity filters. The equivalent thin film technique was able to provide systematic and quantitative design of the WDM thin film filters.

• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2543-2554
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• 2000

Packet schedulers for real-time communication must provide bounded delay and efficient use of network resources such as bandwidth, buffers and so on. In order to satisfy them, a large number of packet scheduling methods have been proposed. Among packet scheduling methods, an EDF (Earliest Deadline First) scheduling is the optimal one for a bounded delay service. A disadvantage of EDF scheduling is that queued packets must be sorted according to their deadlines, requiring a search operation whenever a new packet arrives at the scheduler. Although an RPQ (Rotating Priority Queue) scheduler, requiring large size of buffers, does not use such operation, it can closely approximate the schedulability of an EDF scheduler. To overcome the buffer size problem of an RPQ scheduler, this paper proposes a new scheduler named MRPQ (Multiple Rotating Priority Queue). In a MRPQ scheduler, there are several layers with a set of Queues. In a layer, Queues are configured by using a new strategy named block Queue. A MRPQ scheduler needs nearly half of buffer size required in an RPQ scheduler and produces schedulability as good as an RPQ scheduler.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.6
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• pp.714-721
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• 2020

DNN is expanding its use in embedded systems such as robots and autonomous vehicles. For high recognition accuracy, computational complexity is greatly increased, and multiple DNNs are running aperiodically. Therefore, the ability processing multiple DNNs in embedded environments is a crucial issue. Accordingly, multicore based platforms are being released. However, most DNN models are operated in a batch process, and when multiple DNNs are operated in multicore together, the execution time deviation between each DNN may be large and the end-to-end execution time of the whole DNNs could be long depending on how they are allocated to the cores. In this paper, we solve these problems by providing a framework that decompose each DNN into individual layers and then distribute to multicores through a global queue. As a result of the experiment, the total DNN execution time was reduced by 31%, and when operating multiple identical DNNs, the deviation in execution time was reduced by up to 95.1%.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.3
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• pp.377-387
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• 2006

The objective of this study was to evaluate the influence of multiple adhesive coatings on the thickness of hybrid and adhesive layer and shear bond strength(SBS) of self-etch adhesives and self-etch primer adhesives. The buccal or lingual crown dentin of extracted human molars was used. Self-etch adhesives or self-etch primer adhesives were applied 1, 2 and 3 times on the dentin before light curing. In another group adhesives were reapplied after light curing first layer. Treated surfaces were prepared to measure the thickness of hybrid and adhesive layer with SEM, and shear bond strength to dentin using an Instron machine. The following results were obtained : 1. The adhesive layers increased with the number of coatings(p<0.05) with all adhesives. Adpor Prompt L-Pop and Xeno III were significantly thinner than self-etch primer adhesives (p<0.05). 2. The thickness of hybrid layers increased with the number of coatings (p<0.05). 3. The shear bonding strength of Unifil Bond and Clearfill SE Bond were higher than Scotchbond Multipurpose Plus and Adpor Prompt L-Pop (p<0.05), and similar with Xeno III. 4. The shear bond strength increased significantly with the number of coatings in Adpor Prompt L-Pop(p<0.05), but decreased at 3 times in AdheSE Bond(p>0.05). 5. In Adpor Prompt L-Pop and Xeno III, the shear bond strength decreased when adhesives were reapplied after curing the first adhesive layer.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1747-1749
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• 1999

Organic electroluminescent devices (OLEDs) have received a great deal of attention due to their potential application as full-color displays. Europium complexes are known as excellent red color-emitting materials for OLEDs since they show intense photoluminescence at around 610 nm with a sharp spectral bandwidth. In this study, triple-layer and multiple quantum-well structures consisting of Eu$(TTA)_3$(bpy) complex well layer sandwiched triphenyldiamine derivative (TPD) layers were fabricated and their photoluminescent characteristics were investigated. Sharp emission at the wavelength of 615 nm has been observed from the triple-layer and multiple quantum-well structures containing Eu complex. Details on the electrical properties of these structures will be also discussed.

• Journal of Korea Multimedia Society
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• v.20 no.8
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• pp.1406-1420
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• 2017

Artificial neural networks (ANNs) play an important role in the fields of function approximation, prediction, and classification. ANN performance is critically dependent on the input parameters, including the number of neurons in each layer, and the optimal values of weights and biases assigned to each neuron. In this study, we apply the particle swarm optimization method, a popular optimization algorithm for determining the optimal values of weights and biases for every neuron in different layers of the ANN. Several regression models, including general linear regression, Fourier regression, smoothing spline, and polynomial regression, are conducted to evaluate the proposed method's prediction power compared to multiple linear regression (MLR) methods. In addition, residual analysis is conducted to evaluate the optimized ANN accuracy for both training and test datasets. The experimental results demonstrate that the proposed method can effectively determine optimal values for neuron weights and biases, and high accuracy results are obtained for prediction applications. Evaluations of the proposed method reveal that it can be used for prediction and estimation purposes, with a high accuracy ratio, and the designed model provides a reliable technique for optimization. The simulation results show that the optimized ANN exhibits superior performance to MLR for prediction purposes.

• Restorative Dentistry and Endodontics
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• v.29 no.5
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• pp.423-429
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• 2004

The purpose of this study was to evaluate the effect of multiple application of all-in-one dentin adhesive system on microtensile bond strength using confocal laser scanning microscope and microtensile bond strength test. Flat occlusal dentin surfaces were prepared using low-speed diamond saw. In group I, Scotchbond Multipurpose (SM) was applied by manufacturer's recommendation. In group II, after Adper Prompt L-Pop was applied for 15s and light cured for 10s. the second coat was re-applied and light-cured. In group III, after light-curing the second layer. the third coat was re-applied and light-cured. Specimens bonded with a resin-composite were sectioned into resin-dentin stick for measuring the adhesive layer thickness by confocal laser scanning microscope and evaluating micro-tensile bond strength. The adhesive layers of three-step dentin adhesive system. 3 coats of Adper Prompt L-Pop had significantly thicker than SM. 2 coats of Adper Prompt L-Pop (p < 0.05). However. there was no significant differences in bond strengths between SM and 3 coats of Adper Prompt L-Pop (p > 0.05). And SM. 3 coats of Adper Prompt L-Pop had significantly higher than 2 coats of Adper Prompt L-Pop in bond strengths (p < 0.05).

• Environmental Engineering Research
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• v.22 no.1
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• pp.75-86
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• 2017

The aerosol content dynamics in a virtual system were investigated. The outcome was extended to monitor the mean concentration diffusion of aerosols in a predefined macro and micro scale. The data set used were wind data set from the automatic weather station; satellite data set from Total Ozone Mapping Spectrometer aerosol index and multi-angle imaging spectroradiometer; ground data set from Aerosol robotic network. The maximum speed of the macro scale (West Africa) was less than 4.4 m/s. This low speed enables the pollutants to acquire maximum range of about 15 km. The heterogeneous nature of aerosols layer in the West African atmosphere creates strange transport pattern caused by multiple refractivity. It is believed that the multiple refractive concepts inhibit aerosol optical depth data retrieval. It was also discovered that the build-up of the purported strange transport pattern with time has enormous potential to influence higher degrees of climatic change in the long term. Even when the African Easterly Jet drives the aerosols layer at about 10 m/s, the interacting layers of aerosols are compelled to mitigate its speed to about 4.2 m/s (macro scale level) and boost its speed to 30 m/s on the micro scale level. Mean concentration diffusion of aerosols was higher in the micro scale than the macro scale level. The minimum aerosol content dynamics for non-decaying, logarithmic decay and exponential decay particulates dispersion is given as 4, 1.4 and 0 respectively.