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Mean wavelength stability of broadband erbium-doped fiber sources (광대역폭 Erbium 첨가 광섬유 광원의 중심파장 안정성)

  • 진영준;박희갑
    • Korean Journal of Optics and Photonics
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    • v.8 no.6
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    • pp.476-481
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    • 1997
  • Optimum operating conditions of the 0.98 $\mu\textrm{m}$-pumped broadband erbium-doped fiber sources, where the mean wavelength variation is minimized, have been experimentally investigated. The optimum conditions for the mean wavelength stabilization were found to be different between the case of the isolated source and the case of the presence of feedback. In case of feedback, the proper pump power that yields zero slope of mean wavelength variation was found to be lower than that of the isolated case, and the mean wavelength was found nearly unchanged over the wide range of pump power. Howerer, the feedback resulted in lower output power and the mean wavelength was found to be sensitive to the variation of feedback level. In the respect of mean wavelength stability, the better performance could be obtained with some feedback, provided that the feedback level is kept constant. Thus we could also enhance the mean wavelength stability by allowing appropriate constant feedback into the source.

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MEAN-FIELD BACKWARD STOCHASTIC DIFFERENTIAL EQUATIONS ON MARKOV CHAINS

  • Lu, Wen;Ren, Yong
    • Bulletin of the Korean Mathematical Society
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    • v.54 no.1
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    • pp.17-28
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    • 2017
  • In this paper, we deal with a class of mean-field backward stochastic differential equations (BSDEs) related to finite state, continuous time Markov chains. We obtain the existence and uniqueness theorem and a comparison theorem for solutions of one-dimensional mean-field BSDEs under Lipschitz condition.

Estimation of Mean Using Multi Auxiliary Information in Presence of Non Response

  • Kumar, Sunil;Singh, Housila P.
    • Communications for Statistical Applications and Methods
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    • v.17 no.3
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    • pp.391-411
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    • 2010
  • For estimating the mean of a finite population, three classes of estimators using multi-auxiliary information with unknown means using two phase sampling in presence of non-response have been proposed with their properties. Asymptotically optimum estimator(AOE) in each class has been identified along with their mean squared error formulae. An empirical study is also given.

Evaluation of 119 emergency medical technicians' work related musculoskeletal disorders risk with regard to patient lifting procedures (119 구급대원의 업무관련성 근골격계 손상 위험성 평가 - 환자 들기 작업을 중심으로 -)

  • Son, Jeong-Won
    • The Korean Journal of Emergency Medical Services
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    • v.23 no.1
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    • pp.101-112
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    • 2019
  • Purpose: The purpose of the study was to contribute to the prevention of musculoskeletal disorders (MSDs) in 119 emergency medical technicians (EMTs) by evaluating ergonomic risk factors of patient lifting work-postures. Methods: Four procedures were evaluated: using long back-board (LBB) on the sitting and standing main stretcher, using variable stretcher on the sitting and standing main stretcher. Wok-postures were assessed during training. Results: In using LBB on the sitting main stretcher, the OWAS-score was Mode:3 (Mean:2.30, Maximum:3), the REBA-score was Mode:9 (Mean:7.61, Maximum:11), requiring improvement soon. In using LBB on the standing main stretcher, the OWAS-score was Mode:3 (Mean:2.33, Maximum:3), requiring as soon as possible corrective action, the REBA-score was Mode:6 (Mean:5.44, Maximum:11), requiring improvement. In using variable stretcher on the sitting main stretcher, the OWAS-score was Mode:1 (Mean:1.85, Maximum:3), not requiring corrective action, the REBA-score was Mode:6 (Mean:6.78, Maximum:11), requiring improvement. In using variable stretcher on the standing main stretcher, the OWAS-score was Mode:3 (Mean:2.84, Maximum:3), requiring as soon as possible corrective action, the REBA-score was Mode:11 (Mean:9.38, Maximum:11), requiring immediate improvement. Conclusion: All four-procedures showed improvement in work-posture. Thereby, required attention and management in training, occupational health professionals should participate in change of lifting-method, and programs aimed at preventing MSDs should be developed and implemented in fire-academy and fire-station.

Investigation on the Inhabitation Environments and Growth Conditions of Machilus thunbergii Community in Pyonsanbando (변산반도내 후박나무군락의 서식환경 및 생육실태에 관한 조사연구)

  • 박종민
    • Korean Journal of Environment and Ecology
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    • v.12 no.3
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    • pp.242-252
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    • 1998
  • The inhabitation environments and growth conditions of Machilus thunbergii community in the Pyonsanbando located at southwestern area in Korea were examined and analyzed to provide some practical data to be used to establish measures for long term succession monitoring, protection and sustainable management. The Machilus thunbergii community are located at Kyokpo-ri, Pyonsan-myon, Puan-gun(35$^{\circ}$35′24"N~35$^{\circ}$ 42′30"N, 126$^{\circ}$28′18"E~126$^{\circ}$40′40"E). Within the Pyonsanbando area the mean temperature is 12.4$^{\circ}C$, the warmth index 101.5$^{\circ}C$.month, the coldness index -12.3$^{\circ}C$ month and the annual precipitation 1,016mm. The soil within the community is silt loam or clay loam and so fertile. 30 species and 1 varieties of 21 families inhabited at the community. There were 18 grown trees and 131 saplings of Machilus thunbergii within the community. The mean basal diameter, mean height, and crown width of grown trees was measured to be 57.4cm, 7.4m and 9.0~9.8m respectively. And 9 trees were full flowering, 2 trees small flowering here and there, and 7 trees non flowering in 1998. The mean branch growth length was 8.3cm, mean leaf area 18.3$\textrm{cm}^2$, mean inflorecence length 9.3cm, mean fertilization 14.5% and mean seed diameter 7.6mm. Further rich management measure and investigation were recommended such as sapling protection, signboard construction, soil erosion controlling and regular monitoring within the community.

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Blood chemistry profiles in indigenous Korean striped calves from birth up to the age of 2 months (칡소 송아지의 생후 2개월간 혈액화학치 양상에 관한 연구)

  • Cho, Kwang-Hyun;Park, Yong-Soo;Kim, Seong-Guk;Do, Jae-Cheul;Eo, Kyung-Yeon;Kwak, Dongmi;Kwon, Oh-Deog
    • Korean Journal of Veterinary Service
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    • v.39 no.3
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    • pp.151-157
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    • 2016
  • The present study was undertaken to clarify the changes in blood chemical values of indigenous Korean striped calves according to age. Blood samples were collected from 15 calves (8 females and 7 males) reared at the Gyeongsangbukdo Livestock Research Institute and the levels of various chemicals in serum were analyzed. The mean total protein, albumin and globulin concentration in calves increased from 2 weeks after birth, and the levels in females were higher than those in males at 8 weeks after birth. The mean glucose concentration increased significantly at 2 weeks after birth. The mean blood urea nitrogen concentration increased from 2 weeks after birth, whereas the mean creatinine concentration decreased significantly from 2 weeks after birth. The mean uric acid concentration increased gradually from 2 weeks after birth. The mean glutamic oxaloacetic transaminase and glutamic pyruvic transaminase concentration increased significantly from 2 weeks after birth. The mean total bilirubin concentration tended to decrease from 2 weeks after birth. The mean triglyceride, total cholesterol and high density lipoprotein cholesterol concentration increased significantly from 2 weeks after birth. In conclusion, the data obtained from this study may be valuable as a standard for interpreting results of biochemical analyses in indigenous Korean striped calves.

Technical Influences and Caring Attributes of Nurses' Perceptions (의료기계장비 발달의 영향과 돌봄의 속성에 대한 간호사의 지각)

  • Sohng Kyeong-Yae;Noh Choon-Hee
    • Journal of Korean Public Health Nursing
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    • v.13 no.2
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    • pp.84-100
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    • 1999
  • Caring is the essential and universal concept of underlying nursing. Exactly how caring attributes relate to nurses' perception in the context of a contemporary technological environment have yet to be operationlized. In total. 560 Registered Nurses from 5 different university hospitals were involved in this study which aimed to : investigate technological influence and caring attributes as perceived by nurse. Data were obtained using Technological Influence Questionnaire (TIQ) and Caring Attributes Questionnaires(CAQ) which developed by Arthur et al(1999). Data were analyzed using SAS program for frequency. t-test. ANOVA and Tukey's Studentized Range test. and Pearson correlation coefficients. The results were as follows : 1) The mean score of TIQ was 48.84 and special unit nurses' TIQ was higher than that of general ward nurses. 2) The mean score of CAQ was 237.02 and it showed significant differences in the following variables : age. religion. educational background. marital status. career, and position. 3) With regard to the mean item score of CAQ by 3 perspectives : theoretical perspectives score was 3.76. practical perspectives score was 4.03, and pedagogical perspectives score was 3.84. 4) The correlation between TIQ score and CAQ score was slightly moderate (r=.35), The CAQ mean scsre was significantly different accordig to the level of TIQ meen score. The CAQ mean score was $247.19(\pm18.17)$ in high TIQ(>mean+1SD) group, $236.21(\pm19.71)$ In moderate $TIQ(between\;mean{\pm}1SD) $ group, and $228.47(\pm18.07)$ in low TIQ( (mean-1SD) group. In conclusion, nurses perceived the CAQ differently by several demographic characteristics which relating to age. religion, eduacational background. marital status. career. and position. This study provides an important message for administrators and nurse educators by highlighting factors which can be addressed by education programs. staff development and appraisal. Further research is necessary to improve and refine the Korean version of TIQ and CAQ instead of Arthur et al's scales directly to Korean nurses.

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Zinc and Copper Intake with Food Analysis and Levels of Zinc and Copper in Serum, Hair and Urine of Female College Students (도시 여대생에 있어 식품분석에 의한 아연, 구리섭취량과 혈액, 머리카락, 소변의 아연, 구리 함량에 관한 연구)

  • 손숙미
    • Journal of Nutrition and Health
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    • v.32 no.6
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    • pp.705-712
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    • 1999
  • The purpose of this study was to assess the zinc and copper nutritional status of 102 college women by measuring zinc and copper intake, hematological parameters of zinc and copper, hair zinc and urinary excretion of zinc and copper. The mean zinc intake was 5.5mg(45.8% RDA) with food analysis and 4.5mg(37.8% RDA) with computation from food composition table. The copper intake with food analysis was 2.3mg and 1.2mg with computation. Mean serum zinc concentration was 77.02ug/dl and the proportion of subjects with zinc deficiency estimated by serum zinc(<70ug/dl)was 23.0%. Mean serum copper concentration was 121.80ug/dl and 4.1% of subjects showed serum copper less than 70ug/dl, The mean ceruloplasmin concentration was 22.63mg/dl and the proportion of subjects whose ceruloplasmin was lower than 18-40mg/dl was 6.6%. The mean hair zinc of subjects was 143.8ppm and the mean hair copper was 11.2ppm. The mean urinary excretion of zinc was 0.43mg/day and the proportion of subjects with marginal deficiency estimated by urinary zinc excretion( <0.3mg/day) was 23.3%. The mean urinary copper excretion was 0.044mg/day which was within the normal range(0.01-0.06mg/day). Assessing by zinc content in hair, urine and serum, 22.9-23.3% of college women had bordeline zinc deficiency or zinc deficiency. Whereas 4.1-6.6% of college women was assessed copper deficiency estimated by serum copper and ceruloplasmin.

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Variation of Water Level on the Upstream Gauging Station by Operation of the Drainage Sluice Gate of Geumgang Estuary Dam (금강하구둑 배수갑문 조작에 의한 상류수역의 수위변동)

  • Park, Seung-Ki
    • Journal of The Korean Society of Agricultural Engineers
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    • v.47 no.6
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    • pp.15-24
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    • 2005
  • The normalization on the characteristics of water level change at the upstream gauging station was attempted according to the operation of drainage sluice gate of the Geumgang estuary dam. The characteristics were normalized by the analysis of water level change and by the linear-regression of the water level data measured at the inner station of Geumgang estuary dam and upstream gauging station. The results of normalization may be referred to the management of Geumgang estuary lake, the operation of pumping and drainage stations in the shore of the lake. The mean response time of water level change on Ibpo, Ganggyeong and Gyuam water level station were 39,81 and 160 minutes, when sluice gate was opened respectively. The mean velocity of surface wave, the mean displacement of water level change, the mean time of water level change and the mean rate of water level change varied largely depending on the location of gauging station and the characteristics of stream section of the water level gauging station.

CT Based 3-Dimensional Treatment Planning of Intracavitary Brachytherapy for Cancer of the Cervix : Comparison between Dose-Volume Histograms and ICRU Point Doses to the Rectum and Bladder

  • Hashim, Natasha;Jamalludin, Zulaikha;Ung, Ngie Min;Ho, Gwo Fuang;Malik, Rozita Abdul;Ee Phua, Vincent Chee
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.13
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    • pp.5259-5264
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    • 2014
  • Background: CT based brachytherapy allows 3-dimensional (3D) assessment of organs at risk (OAR) doses with dose volume histograms (DVHs). The purpose of this study was to compare computed tomography (CT) based volumetric calculations and International Commission on Radiation Units and Measurements (ICRU) reference-point estimates of radiation doses to the bladder and rectum in patients with carcinoma of the cervix treated with high-dose-rate (HDR) intracavitary brachytherapy (ICBT). Materials and Methods: Between March 2011 and May 2012, 20 patients were treated with 55 fractions of brachytherapy using tandem and ovoids and underwent post-implant CT scans. The external beam radiotherapy (EBRT) dose was 48.6Gy in 27 fractions. HDR brachytherapy was delivered to a dose of 21 Gy in three fractions. The ICRU bladder and rectum point doses along with 4 additional rectal points were recorded. The maximum dose ($D_{Max}$) to rectum was the highest recorded dose at one of these five points. Using the HDRplus 2.6 brachyhtherapy treatment planning system, the bladder and rectum were retrospectively contoured on the 55 CT datasets. The DVHs for rectum and bladder were calculated and the minimum doses to the highest irradiated 2cc area of rectum and bladder were recorded ($D_{2cc}$) for all individual fractions. The mean $D_{2cc}$ of rectum was compared to the means of ICRU rectal point and rectal $D_{Max}$ using the Student's t-test. The mean $D_{2cc}$ of bladder was compared with the mean ICRU bladder point using the same statistical test. The total dose, combining EBRT and HDR brachytherapy, were biologically normalized to the conventional 2 Gy/fraction using the linear-quadratic model. (${\alpha}/{\beta}$ value of 10 Gy for target, 3 Gy for organs at risk). Results: The total prescribed dose was $77.5Gy{\alpha}/{\beta}10$. The mean dose to the rectum was $4.58{\pm}1.22Gy$ for $D_{2cc}$, $3.76{\pm}0.65Gy$ at $D_{ICRU}$ and $4.75{\pm}1.01Gy$ at $D_{Max}$. The mean rectal $D_{2cc}$ dose differed significantly from the mean dose calculated at the ICRU reference point (p<0.005); the mean difference was 0.82 Gy (0.48-1.19Gy). The mean EQD2 was $68.52{\pm}7.24Gy_{{\alpha}/{\beta}3}$ for $D_{2cc}$, $61.71{\pm}2.77Gy_{{\alpha}/{\beta}3}$ at $D_{ICRU}$ and $69.24{\pm}6.02Gy_{{\alpha}/{\beta}3}$ at $D_{Max}$. The mean ratio of $D_{2cc}$ rectum to $D_{ICRU}$ rectum was 1.25 and the mean ratio of $D_{2cc}$ rectum to $D_{Max}$ rectum was 0.98 for all individual fractions. The mean dose to the bladder was $6.00{\pm}1.90Gy$ for $D_{2cc}$ and $5.10{\pm}2.03Gy$ at $D_{ICRU}$. However, the mean $D_{2cc}$ dose did not differ significantly from the mean dose calculated at the ICRU reference point (p=0.307); the mean difference was 0.90 Gy (0.49-1.25Gy). The mean EQD2 was $81.85{\pm}13.03Gy_{{\alpha}/{\beta}3}$ for $D_{2cc}$ and $74.11{\pm}19.39Gy_{{\alpha}/{\beta}3}$ at $D_{ICRU}$. The mean ratio of $D_{2cc}$ bladder to $D_{ICRU}$ bladder was 1.24. In the majority of applications, the maximum dose point was not the ICRU point. On average, the rectum received 77% and bladder received 92% of the prescribed dose. Conclusions: OARs doses assessed by DVH criteria were higher than ICRU point doses. Our data suggest that the estimated dose to the ICRU bladder point may be a reasonable surrogate for the $D_{2cc}$ and rectal $D_{Max}$ for $D_{2cc}$. However, the dose to the ICRU rectal point does not appear to be a reasonable surrogate for the $D_{2cc}$.