• International Journal of Highway Engineering
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• v.19 no.2
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• pp.1-6
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• 2017

PURPOSES : Pavement textures can be categorized into four according to wavelength: microtexture, macrotexture, megatexture (roads), and roughness. Pavement surface texture influences a number of aspects of tire-pavement interaction such as wet-weather friction, tire-pavement noise, splash, spray, tire-wear, and rolling resistance. In particular, macrotexture is the pavement surface characteristic that considerably impacts tire-pavement noise. In general, it can be demonstrated that tire-pavement noise increases with the increase of texture depth and wavelength. Recently, mean profile depth (MPD) and wavelength have been used to evaluate tire-pavement noise. This study aimed to identify the relationship between mean profile depth and average wavelength for asphalt pavement based on the information obtained on a number of asphalt pavement sections. METHODS : Profile data were collected from a number of expressway sections in Korea. In addition, mean profile depth and average wavelength were calculated by using this profile data. Statistical analysis was performed to determine the correlationship between mean profile depth and average wavelength. RESULTS:This study demonstrates a linear relationship between mean profile depth and average wavelength for asphalt concrete pavement. CONCLUSIONS :The strong relationship between mean profile depth and average wavelength of asphalt pavement was determined in this study.

• Journal of Power System Engineering
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• v.17 no.5
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• pp.38-43
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• 2013

In order to design a wave energy generating system, a 6-DOF analysis technique is applied to CFD analysis on of a floating body and the behavior is interpreted according to the nature of the incoming waves. A spring constant is adopted to control the motion of multi floating bodies and to calculate the total average power absorption. Three cases of different wavelengths namely 20D, 30D and 40D have been modeled to analyze the total average power absorption. The average power absorption not only varies with the position of the floating body but also varies with wavelength. From the results obtained, it is concluded that the maximum total average power absorption is 9W approximately in wavelength 30D and the minimum total average power absorption is 4.3W approximately in wavelength 40D.

• Journal of the Optical Society of Korea
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• v.8 no.2
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• pp.55-58
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• 2004

Several internal wavelength locker schemes for 10 Gbps electro-absorption modulated laser EML) module were reviewed. 10 Gbps EML modules with simple and robust internal wavelength ockers for metro dense WDM application were successfully demonstrated. The wavelength aging ver 2000 hours was done at elevated temperature of 7$0^{\circ}C$. The average wavelength drift of 10 modules was measured to be about $\pm$ 5 pm. These modules can be successfully applied to the 0 Gbps DWDM systems with 50 ㎓ channel spacing.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.8
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• pp.119-125
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• 1995

Strained multiple quantum well(SMQW) PBH-DFB-LDs emitting at 1.55$\mu$m wavelength has been fabricated using OMVPE and LPE crystal growth tecnique. Using the SMQW active layer, a linewidty enhancement factor of 2.65 was obtained at lasing wavelength and consequnently, packaged 42 modules showed a very low average chirp of 0.44nm at 2.5Gbps NRZ direct modulation. The 77 devices showed average threshold current of 8.72mA and average slope efficiency of 0.181 mW/mA, and single longitudinal mode operation with SMSR larger than 30dB up to 5mW. Among the 77 devices, standard deviation of lasing wavelength of 3.57nm was obtained owing to a good crystal growth uniformity.

• Journal of Biomedical Engineering Research
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• v.17 no.4
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• pp.491-498
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• 1996

The development of a compact two-wavelength Nd:YAG laser for dental and ENT applications is presented. The Nd:YAG resonator generates either 1.06$\mu$m or 1.32$\mu$m. The wavelength selection is made at the control panel. The Nd:YAG laser parameters at 1.06$\mu$m are ; the maximum pulse duration of 150$\mu$s, repetition rates of I-100Hz, and the maximum average power of 25W. At 1.32$\mu$m, the pulse duration is the same where the repetition rates and the maximum average power are I-30Hz and lOW respectively. High voltage power supply consists of a simmer module and two identical high voltage DC converters. In order to make a complete medical laser system, an optical fiber delivery unit, foot pedal and water spray handpiece are also developed. The wavelength selection is reliable since no movement of optical or mechanical components is required. The high voltage power supply is compact, easy to be maintained and applicable for other laser systems due to its modular design.

• Journal of Microbiology and Biotechnology
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• v.25 no.1
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• pp.109-118
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• 2015

Open raceway ponds are cost-efficient for mass cultivation of microalgae compared with photobioreactors. Although low-cost options like wastewater as nutrient source is studied to overcome the commercialization threshold for biodiesel production from microalgae, a cost analysis on the use of wastewater and other incremental increases in productivity has not been elucidated. We determined the effect of using wastewater and wavelength filters on microalgal productivity. Experimental results were then fitted into a model, and cost analysis was performed in comparison with control raceways. Three different microalgal strains, Chlorella vulgaris AG10032, Chlorella sp. JK2, and Scenedesmus sp. JK10, were tested for nutrient removal under different light wavelengths (blue, green, red, and white) using filters in batch cultivation. Blue wavelength showed an average of 27% higher nutrient removal and at least 42% higher chemical oxygen demand removal compared with white light. Naturally, the specific growth rate of microalgae cultivated under blue wavelength was on average 10.8% higher than white wavelength. Similarly, lipid productivity was highest in blue wavelength, at least 46.8% higher than white wavelength, whereas FAME composition revealed a mild increase in oleic and palmitic acid levels. Cost analysis reveals that raceways treating wastewater and using monochromatic wavelength would decrease costs from 2.71 to 0.73 $/kg biomass. We prove that increasing both biomass and lipid productivity is possible through cost-effective approaches, thereby accelerating the commercialization of low-value products from microalgae, like biodiesel.

• Journal of Sensor Science and Technology
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• v.26 no.5
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• pp.324-330
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• 2017

In this paper, the automation of sweeping center setting for wavelength swept laser used in SS-OCT has implemented. For 3 regions where the initial FFP-TF pass wavelength can be located, each different DC voltage pattern is applied to FFP-TF. Through its performance test to the laser, fast and exact setting to sweeping central wavelength, flat sweeping with ${\pm}0.5dB$ fluctuation range, and 10 mW average optical power were obtained. This shows that the realized automatic setting process can replace an inconvenient manual setting operation used for current wavelength swept laser. Additionally it cuts costs for optical spectrum analyzer necessary to laser spectrum monitoring.

• International journal of advanced smart convergence
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• v.4 no.1
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• pp.99-103
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• 2015

Quake wavelength technique was designed of the sway by the body. There was presented a concept of the dangle wavelength by twisting condition of posture. We compared to the twisting condition for an average variation and maximum variation with the movement. There was used a combination system and correlation system of the posture. Their correlation signal was presented a control data by the dynamic movement. The quake wavelength system was to be formation of activity aspects by posture. The correlation of wavelength technique was applied to the a little action of posture variation signal. Quake wavelength by the dynamic movement was determined to a variation of vision condition of the $Vi-{\alpha}_{AVG}$ with $(-1.27){\pm}(-0.34)$ units, that vestibular condition of the $Ve-{\alpha}_{AVG}$ with $(-0.49){\pm}(-0.4)$ units, that somatosensory condition of the $So-{\alpha}_{AVG}$ with $0.037{\pm}0.269$ units, that CNS condition of the $C-{\alpha}_{AVG}$ with $(-0.049){\pm}0.015$ units. As the study of the quake wavelength technique was depended on the action system of body movement that a maximum and averag values was used a movement of combination data. The system was required an action signal for the form of actual signal on the basis of a little movement condition in the body. The human action systemwas compared to maximum and average from the movement derived the body. Therefore, their system was controlled to evaluate posture condition for the body correlation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.7
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• pp.1393-1397
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• 2009

A high-speed wavelength swept laser, which is based on oscillation characteristics of a fiber Fabry-Perot tunable filter, is described. The laser is constructed by using a semiconductor optical amplifier, a fiber Fabry-Perot tunable filter, and 3.348 km fiber ring cavity. The wavelength sweeps are repeatatively generated with the repetition period of 61 kHz which is the first parallel oscillation frequency of the Fabry-Perot tunable filter for the low power consumption. Mode-locking is implemented by 3.348 km fiber ring cavity for matching the fundamental of cavity roundtrip time to the sweep period. The wavelength tuning range of the laser is 87 nm(FWHM) and the average output power is 1.284 mW.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.150-151
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• 2014

This paper evaluates performance of a dynamic wavelength and bandwidth allocation algorithm of TWDM PON (time and wavelength division multiplexed passive optical network) which consists of an OLT (optical line termination) and multiple ONU (optical network unit). The allocation algorithm reduces the number of upstream wavelengths to save power. Using self-similar traffic, we simulate TWDM PON systems and measure the average packet delay and the average number of upstream wavelengths.