• Title/Summary/Keyword: optical fiber

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Scientific Investigation of the Clothes Collected at Comfort Station in Nara, Japan (일본 나라현 위안소 수습 의복 조사 및 과학적 분석)

  • Choi, Jung Eun;Jeon, Yu Ree;Lee, Yu Jin;Kim, Min Seo;Jin, Chul Min
    • Journal of Conservation Science
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    • v.33 no.5
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    • pp.363-370
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    • 2017
  • The aim of this study was to obtain information about two early-20th Century clothes, for which the "National Memorial Museum of Forced Mobilization under Japanese Occupation" has sought to receive preservation treatment. Optical microscopes and a scanning electron microscope were used to investigate the weaving of the clothes, and Fourier transform infrared spectroscopy(FT-IR) was used to investigate the fibers. Cloth A is believed to be a Japanese half sleeved inner wear(Hanjuban) used by women. Cloth B is believed to be working clothing that was checked by an Osaka plant. This was verified by a book written by the Japanese army. Both of the clothes were made mostly from cotton, although the inner wear also used viscose rayon on the neck collar. The button on the working wear was made of urea formaldehyde resin, an early precursor to plastic.

An Exploratory Study on Luminescent Properties and the Relevant Applications of POF-based Flexible Textile Display for Mountaineer Wear with Safe-guard Function (안전보호 기능의 산악복을 위한 유연 광섬유 직물 디스플레이의 발광특성 및 적용에 관한 탐색적 연구)

  • Kim, Jin-Sun;Park, Soo-Jin;Kim, Yu-Ji;Lee, Joo-Hyeon
    • Science of Emotion and Sensibility
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    • v.14 no.1
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    • pp.165-174
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    • 2011
  • Recent years have witnessed that IT-convergence technology has become the most important issue in the global market. Along with this trend, demand for PSS(i.e., Product-Service Systems) design has been rapidly increased in the smart clothing market. A case of the PSS design research, this study aimed to identify optimum conditions for weaving of POF-based flexible textile display(abbreviated as "PFTD") for mountaineer wear with safe-guard function regarding luminescent properties. Based on the findings regarding the optimum weaving condition of PFTD, several designs of mountaineer wear were suggested in this study. A total of 15 PFTD samples were prepared under various weaving conditions of weave structures and density of POF, and the luminance values of each sample were measured. As the results, the types of PFTD with structures and density of 'satin 3:1', 'satin 2:1', 'twill 3:1' and 'twill 2:1' indicated relatively higher luminescence. And based on the results and recent sports fashion trends, two suited mountaineering wears applying PFTD were illustrated in this study.

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Performance Analysis of the Powerline Communication for Condition Monitoring System of an MW Class Offshore Wind Turbine's Nacelle (MW급 해상풍력발전기 나셀의 상태 감시를 위한 전력선 통신 성능 분석)

  • Sohn, Kyung-Rak;Kim, Kyoung-Hwa;Jeong, Seong-Uk;Nam, Seung-Yun;Kim, Hyun-Sik
    • Journal of Navigation and Port Research
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    • v.40 no.3
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    • pp.159-164
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    • 2016
  • The goal of this study is to implement a communication system that can monitor the status of the nacelle using the power cable itself, without the dedicated communication lines such as an UTP cable and optical fiber for the offshore wind turbine. An inductive coupling powerline communication system for a MW class offshore wind turbine was proposed and its communication performance was demonstrated. The inductive couplers was designed for operation at up to 500 A using a ferrite composite materials. Field test was carried out on the wind farms of Jeju island. Using the iperf communication test program, we have obtained more than 15 Mbps data transmission rate through the 100 m power cable that was installed between the nacelle and the bottom of the power converter. In the data transmission stability test for a week, there was no failure ever. The minimum transmission rate was 15 Mbps and the average data rate was about 20 Mbps. Next, we have installed an infrared camera inside the nacelle in order to measure the temperature distribution and variation of the nacelle. The real-time thermal image taken by the camera was successfully sent to the monitoring system without error.

Toxic Optic Neuropathy Caused by Chlorfenapyr Poisoning (클로르페나피르 음독 후 발생한 독성 시신경병증 1예)

  • Park, Su Jin;Jung, Jae Uk;Kang, Yong Koo;Chun, Bo Young;Son, Byeong Jae
    • Journal of The Korean Ophthalmological Society
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    • v.59 no.11
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    • pp.1097-1102
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    • 2018
  • Purpose: To report a case of toxic optic neuropathy caused by chlorfenapyr ingestion accompanied by central nervous system involvement. Case summary: A 44-year-old female visited our clinic complaining of reduced visual acuity in both eyes for 7 days. She had ingested a mouthful of chlorfenapyr for a suicide attempt 2 weeks prior to the visit. Gastric lavage was performed immediately after ingestion at the other hospital. Her best-corrected visual acuity was finger count 30 cm in the right eye and hand motion in the left eye. Both pupils were dilated by 5.0 mm and the response to light was sluggish in both eyes. A relative afferent pupillary defect was detected in her left eye. Funduscopy revealed optic disc swelling in both eyes. Magnetic resonance imaging of the brain showed a symmetric hyper-intense signal in the white matter tract including the internal capsule, corpus callosum, middle cerebellar peduncle, and brainstem. The patient was diagnosed with toxic optic neuropathy induced by chlorfenapyr ingestion, and underwent high-dose intravenous corticosteroid pulse therapy. Three days later, the best-corrected visual acuity was no light perception in both eyes. Three months later, optic atrophy was observed in both eyes. Optical coherence tomography revealed a reduction in the thicknesses of the retinal nerve fiber layer and ganglion cell and inner plexiform layer in the macular area. Conclusions: Ingestion of even a small amount of chlorfenapyr can cause severe optic nerve damage through the latent period, despite prompt lavage and high-dose steroid treatment.

Linewidth Reduction of a Yellow Laser by a Super-cavity and the Measurement of the Cavity Finesse (초공진기를 이용한 노란색 레이저의 선폭 축소 및 초공진기의 예리도 측정)

  • Lee, Won-Kyu;Park, Chang-Yong;Park, Sang-Eon;Ryu, Han-Young;Yu, Dai-Hyuk;Mun, Jong-Chul;Suh, Ho-Suhng
    • Korean Journal of Optics and Photonics
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    • v.21 no.3
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    • pp.123-128
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    • 2010
  • Sum frequency generation was utilized to obtain a yellow laser with the wavelength of 578.4 nm for a probe laser of an Yb lattice clock. The output of an Nd:YAG laser with wavelength of 1319 nm and that of an Yb-fiber laser with wavelength of 1030 nm were passed through a waveguided periodically-poled lithium niobate (WG-PPLN) for sum frequency generation. It is required that the probe laser has a linewidth of the order of 1 Hz to fully resolve the Yb lattice clock transition. Thus, the linewidth of the probe laser was reduced by stabilizing the frequency to a super-cavity. This was made of ULE with a low thermal expansion coefficient, and was mounted on an active vibration-isolation table at the optimal point for the reduced sensitivity to vibration. Also, this was installed in a vacuum chamber, and the temperature was stabilized to 1 mK level. This system was installed in an acoustic enclosure to block acoustic noise. The finesse of the super-cavity was measured to be 380 000 from the photon life time of the cavity.

Non-ablative Fractional Thulium Laser Irradiation Suppresses Early Tumor Growth

  • Yoo, Su Woong;Park, Hee-Jin;Oh, Gyungseok;Hwang, Soonjoo;Yun, Misun;Wang, Taejun;Seo, Young-Seok;Min, Jung-Joon;Kim, Ki Hean;Kim, Eung-Sam;Kim, Young L.;Chung, Euiheon
    • Current Optics and Photonics
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    • v.1 no.1
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    • pp.51-59
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    • 2017
  • In addition to its typical use for skin rejuvenation, fractional laser irradiation of early cancerous lesions may reduce the risk of tumor development as a byproduct of wound healing in the stroma after the controlled injury. While fractional ablative lasers are commonly used for cosmetic/aesthetic purposes (e.g., photorejuvenation, hair removal, and scar reduction), we propose a novel use of such laser treatments as a stromal treatment to delay tumorigenesis and suppress carcinogenesis. In this study, we found that non-ablative fractional laser (NAFL) irradiation may have a possible suppressive effect on early tumor growth in syngeneic mouse tumor models. We included two syngeneic mouse tumor models in irradiation groups and control groups. In the irradiation group, a thulium fiber based NAFL at 1927 nm was used to irradiate the skin area including the tumor injection region with 70 mJ/spot, while no laser irradiation was applied to the control group. Numerical simulation with the same experimental condition showed that thermal damage was confined only to the irradiation spots, sparing the adjacent tissue area. The irradiation groups of both tumor models showed smaller tumor volumes than the control group at an early tumor growth stage. We also detected elevated inflammatory cytokine levels a day after the NAFL irradiation. NAFL treatment of the stromal tissue could potentially be an alternative anticancer therapeutic modality for early tumorigenesis in a minimally invasive manner.

Hybrid CMA-ES/SPGD Algorithm for Phase Control of a Coherent Beam Combining System and its Performance Analysis by Numerical Simulations (CMA-ES/SPGD 이중 알고리즘을 통한 결맞음 빔 결합 시스템 위상제어 및 동작성능에 대한 전산모사 분석)

  • Minsu, Yeo;Hansol, Kim;Yoonchan, Jeong
    • Korean Journal of Optics and Photonics
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    • v.34 no.1
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    • pp.1-12
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    • 2023
  • In this study, we propose a hybrid phase-control algorithm for multi-channel coherent beam combining (CBC) system by combining the covariant matrix adaption evolution strategy (CMA-ES) and stochastic parallel gradient descent (SPGD) algorithms and analyze its operational performance. The proposed hybrid CMA-ES/SPGD algorithm is a sequential process which initially runs the CMA-ES algorithm until the combined final output intensity reaches a preset interim value, and then switches to running the SPGD algorithm to the end of the whole process. For ideal 7-channel and 19-channel all-fiber-based CBC systems, we have found that the mean convergence time can be reduced by about 10% in comparison with the case when the SPGD algorithm is implemented alone. Furthermore, we analyzed a more realistic situation in which some additional phase noise was introduced in the same CBC system. As a result, it is shown that the proposed algorithm reduces the mean convergence time by about 17% for a 7-channel CBC system and 16-27% for a 19-channel system compared to the existing SPGD alone algorithm. We expect that for implementing a CBC system in a real outdoor environment where phase noise cannot be ignored, the hybrid CMA-ES/SPGD algorithm proposed in this study will be exploited very usefully.

Effect of Sample Preparations on Prediction of Chemical Composition for Corn Silage by Near Infrared Reflectance Spectroscopy (시료 전처리 방법이 근적외선분광법을 이용한 옥수수 사일리지의 화학적 조성분 평가에 미치는 영향)

  • Park Hyung-Soo;Lee Jong-Kyung;Lee Hyo-Won;Hwang Kyung-Jun;Jung Ha-Yeon;Ko Moon-Suck
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.26 no.1
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    • pp.53-62
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    • 2006
  • Near infrared reflectance spectroscopy (NIRS) has been increasingly used as a rapid, accurate method of evaluating some chemical compositions in forages. Analysis of forage quality by NIRS usually involves dry ground samples. Costs might be reduced if samples could be analyzed without drying or grinding. The objective of this study was to investigate effect of sample preparations and spectral math treatments on prediction ability of chemical composition for corn silage by NIRS. A population of 112 corn silage representing a wide range in chemical parameters were used in this investigation. Samples of com silage were scanned at 2nm intervals over the wavelength range 400-2500nm and the optical data recorded as log l/Reflectance(log l/R) and scanned in overt-dried grinding(ODG), liquid nitrogen grinding(LNG) or intact fresh(IF) condition. Samples were analysed for neutral detergent fiber(NDF), acid detergent fiber(ADF), acid detergent lignin(ADL), crude protein(CP) and crude ash content were expressed on a dry-matter(DM) basis. The spectral data were regressed against a range of chemical parameters using modified partial least squares(MPLS) multivariate analysis in conjunction with four spectral math treatments to reduce the effect of extraneous noise. The optimum calibrations were selected on the basis of minimizing the standard error of cross validation(SECV). The results of this study show that NIRS predicted the chemical parameters with very high degree of accuracy(the correlation coefficient of cross validation$(R^2cv)$ range from $0.70{\sim}0.95$) in ODG. The optimum equations were selected on the basis of minimizing the standard error of prediction(SEP). The Optimum sample preparation methods and spectral math treatment were for ADF, the ODG method using 2,10,5 math treatment(SEP = 0.99, $R^2v=0.93$), and for CP, the ODG method using 1,4,4 math treatment(SEP = 0.29. $R^2v=0.91$).

Evaluation of Feed Values for Imported Hay Using Near Infrared Reflectance Spectroscopy (근적외선분광법을 이용한 수입 건초의 사료가치 평가)

  • Park, Hyung Soo;Kim, Ji Hye;Choi, Ki Choon;Oh, Mirae;Lee, Ki-Won;Lee, Bae Hun
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.39 no.4
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    • pp.258-263
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    • 2019
  • Near infrared reflectance spectroscopy (NIRS) has become increasingly used as a rapid and accurate method of evaluating some chemical compositions in forages. The objective of this study was to evaluate the potential of NIRS, applied to imported forage, to estimate the moisture and chemical parameters for imported hays. A population of 392 imported hay representing a wide range in chemical parameters was used in this study. Samples of forage were scanned at 1 nm intervals over the wavelength range 680-2500nm and the optical data was recorded as log 1/Reflectance(log 1/R), which scanned in intact fresh condition. The spectral data were regressed against a range of chemical parameters using partial least squares(PLS) multivariate analysis in conjunction with spectral math treatments to reduced the effect of extraneous noise. The optimum calibrations were selected based on the highest coefficients of determination in cross validation(R2) and the lowest standard error of cross-validation(SECV). The results of this study showed that NIRS predicted the chemical parameters with very high degree of accuracy. The R2 and SECV for imported hay calibration were 0.92(SECV 0.61%) for moisture, 0.98(SECV 0.65%) for acid detergent fiber, 0.97(SECV 0.40%) for neutral detergent fiber, 0.99(SECV 0.06%) for crude protein and 0.97(SECV 3.04%) for relative feed value on a dry matter(%), respectively. Results of this experiment showed the possibility of NIRS method to predict the moisture and chemical composition of imported hay in Korea for routine analysis method to evaluate the feed value.

Mathematical Transformation Influencing Accuracy of Near Infrared Spectroscopy (NIRS) Calibrations for the Prediction of Chemical Composition and Fermentation Parameters in Corn Silage (수 처리 방법이 근적외선분광법을 이용한 옥수수 사일리지의 화학적 조성분 및 발효품질의 예측 정확성에 미치는 영향)

  • Park, Hyung-Soo;Kim, Ji-Hye;Choi, Ki-Choon;Kim, Hyeon-Seop
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.36 no.1
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    • pp.50-57
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    • 2016
  • This study was conducted to determine the effect of mathematical transformation on near infrared spectroscopy (NIRS) calibrations for the prediction of chemical composition and fermentation parameters in corn silage. Corn silage samples (n=407) were collected from cattle farms and feed companies in Korea between 2014 and 2015. Samples of silage were scanned at 1 nm intervals over the wavelength range of 680~2,500 nm. The optical data were recorded as log 1/Reflectance (log 1/R) and scanned in intact fresh condition. The spectral data were regressed against a range of chemical parameters using partial least squares (PLS) multivariate analysis in conjunction with several spectral math treatments to reduce the effect of extraneous noise. The optimum calibrations were selected based on the highest coefficients of determination in cross validation ($R^2{_{cv}}$) and the lowest standard error of cross validation (SECV). Results of this study revealed that the NIRS method could be used to predict chemical constituents accurately (correlation coefficient of cross validation, $R^2{_{cv}}$, ranging from 0.77 to 0.91). The best mathematical treatment for moisture and crude protein (CP) was first-order derivatives (1, 16, 16, and 1, 4, 4), whereas the best mathematical treatment for neutral detergent fiber (NDF) and acid detergent fiber (ADF) was 2, 16, 16. The calibration models for fermentation parameters had lower predictive accuracy than chemical constituents. However, pH and lactic acids were predicted with considerable accuracy ($R^2{_{cv}}$ 0.74 to 0.77). The best mathematical treatment for them was 1, 8, 8 and 2, 16, 16, respectively. Results of this experiment demonstrate that it is possible to use NIRS method to predict the chemical composition and fermentation quality of fresh corn silages as a routine analysis method for feeding value evaluation to give advice to farmers.