• 제목/요약/키워드: Fiber measurements

검색결과 463건 처리시간 0.034초

포설된 단일모드 광섬유의 손실 특성 측정 (Loss Measurements of Installed Single-Mode Optical Fibers)

  • 전영윤;박재동;이만섭;양권식
    • 한국통신학회논문지
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    • 제16권12호
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    • pp.1266-1273
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    • 1991
  • 장거리 국간 선로에 포설된 단일모드 광섬유의 샘플집단과 모집단의 손실특성을 측정하였고, 구간(중계)거리분포를 측정 분석하였다. 접속손실을 포함한 평균손실은 130nm와 155nm에서 각각 0.55 0.05dB/km, 0.59 0.11/km로써 1550nm대역의 손실이 크게 나타났다. OTDR에 의한 손실특성 조사결과 1550nm대역의 손실증가 주 요인은 접속지점의 부적절한 여장처리에 따른 것이었다. 그리고 국내 평균중계거리는 24 7 km로써 31km 이하의 구간거리가 전체의 약 90%를 차지하고 있었다.

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발한써멀마네킨을 이용한 투습방수의류의 착용쾌적성 평가 (Wear Comfort Evaluation on Water-vapor-permeable (WVP) Garments Using a Movable Sweating Thermal Manikin)

  • 강인형;이한섭
    • 한국의류학회지
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    • 제37권8호
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    • pp.1095-1106
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    • 2013
  • This study evaluated the wear comfort properties of water-vapor-permeable (WVP) garments using a movable sweating thermal manikin. Manikin tests were performed in a climatic chamber (temperature T=20, $35{\pm}0.5^{\circ}C$ and relative humidity $H=50{\pm}10%$) using seven sportswear outfits (a long sleeve shirts and a long pants) made with seven different WVP fabrics. Physiological responses of wear trials could be correlated with measurement parameters of the thermal manikin experiment; subsequently, a regression model that represented a final comfort sensation could be obtained. The regression model developed in this work is based on thermal manikin measurements; consequently, it provides an independent comfort sensation level in a relatively short time at a low cost while maintaining the reproducibility of results. It translates into more actual choices for sportswear manufacturers and sportswear consumers.

Effects of seaweed supplementation on blood glucose concentration, lipid profile, and antioxidant enzyme activities in patients with type 2 diabetes mellitus

  • Kim, Min-Sun;Kim, Jung-Yun;Choi, Woong-Hwan;Lee, Sang-Sun
    • Nutrition Research and Practice
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    • 제2권2호
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    • pp.62-67
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    • 2008
  • The present study was carried out to evaluate the physiological effects of seaweed supplementation on blood glucose levels, lipid profile, and antioxidant enzyme activities in subjects with type 2 diabetes mellitus. Subjects were randomized into either a control group or a seaweed supplementation group. Pills with equal parts of dry powdered sea tangle and sea mustard were provided to the seaweed supplementation group three times a day for 4 weeks. Total daily consumption of seaweed was 48 g. We found that total dietary fiber intake was 2.5 times higher in subjects receiving seaweed supplementation than in the control group. Accordingly, fasting blood glucose levels (p<0.01) and 2-hour postprandial blood glucose measurements (p<0.05) were decreased significantly in those ingesting seaweed. Furthermore, the serum concentrations of triglycerides were decreased and high-density lipoprotein cholesterol was increased significantly in seaweed supplement group (p<0.05). However, the concentrations of total cholesterol and low-density lipoprotein cholesterol were not affected by seaweed supplementation. The level of thiobarbituric acid reactive substances in erythrocytes was significantly lower with seaweed supplementation compared to controls (p<0.05). Catalase and glutathione peroxidase activities with seaweed supplementation were higher than the controls (p<0.05), but superoxide dismutase activity was not affected. We, therefore, conclude that ingestion of seaweed influences glycemic control, lowers blood lipids, and increases antioxidant enzyme activities.

Analysis of various composite patches effect on mechanical properties of notched Al-Mg plate

  • Meran, Ahmad P.;Samanci, Ahmet
    • Steel and Composite Structures
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    • 제25권6호
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    • pp.685-692
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    • 2017
  • In this study, the effect of various adhesively bonded composite patches on mechanical properties of notched Al-Mg alloy plates was analyzed. For this purpose firstly, the un-notched and notched specimens were fabricated from 5086 Al-Mg alloys which have been used in armor-plated military vehicles. The surface notches as a flaw were machined with circular cutting tool to form notch aspect ratio a/c=0.15 and notch-to-thickness ratios a/t=0.5 in the radial direction on the test specimens. Then, various composite patches which reinforced by glass, carbon and Kevlar fibers were bonded adhesively at elliptically surface notches. Finally, experimental measurements conducted by applying tensile static loading. The experimental results showed that repairing with composite patches with order of carbon, glass and Kevlar fibers have remarkable effect on tensile strength of the notched plate. Also the finite element models were developed using Abaqus/Explicit code to predict the tensile strength and elongation of unrepaired notched specimen and specimen repaired by carbon fiber composite patch. The comparison between numerical and experimental results showed good agreement between them and proved the accuracy of numerical modeling.

Free vibration of actual aircraft and spacecraft hexagonal honeycomb sandwich panels: A practical detailed FE approach

  • Benjeddou, Ayech;Guerich, Mohamed
    • Advances in aircraft and spacecraft science
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    • 제6권2호
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    • pp.169-187
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    • 2019
  • This work presents a practical detailed finite element (FE) approach for the three-dimensional (3D) free-vibration analysis of actual aircraft and spacecraft-type lightweight and thin honeycomb sandwich panels. It consists of calling successively in $MATLAB^{(R)}$, via a developed user-friendly GUI, a detailed 3D meshing tool, a macrocommands language translator and a commercial FE solver($ABAQUS^{(R)}$ or $ANSYS^{(R)}$). In contrary to the common practice of meshing finely the faces and core cells, the proposed meshing tool represents each wall of the actual hexagonal core cells as a single two-dimensional (2D) 4 nodes quadrangularshell element or two 3 nodes triangular ones, while the faces meshes are obtained simply using the nodes at the core-faces interfaces. Moreover, as the same 2D FE interpolation type is used for meshing the core and faces, this leads to an automatic handling of their required FE compatibility relations. This proposed approach is applied to a sample made of very thin glass fiber reinforced polymer woven composite faces and a thin aluminum alloy hexagonal honeycomb core. The unknown or incomplete geometric and materials properties are first collected through direct measurements, reverse engineering techniques and experimental-FE modal analysis-based inverse identification. Then, the free-vibrations of the actual honeycomb sandwich panel are analyzed experimentally under different boundary conditions and numerically using different mesh basic cell shapes. It is found that this approach is accurate for the first few modes used for pre-design purpose.

AUDIT-K 척도에 따른 뇌 이랑 부위의 확산텐서 비등방도 측정값 분석 (Analysis of Fractional Anisotropy Measurements of Diffusion Tensor Images in the Gyrus of the Brain by AUDIT-K Scale)

  • 곽종혁;김경립;조희정;이은숙;성순기
    • 한국콘텐츠학회논문지
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    • 제19권7호
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    • pp.176-185
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    • 2019
  • AUDIT-K 척도에 따른 중년남성을 대상으로 뇌 회백질의 손상 유무를 파악 할 수 있는 확산텐서영상을 검사하여 영상을 획득 한 후 Tract-Based Spatial Statics(TBSS)방법으로 뇌 회백질 부위의 이랑(Gyrus) 신경 섬유로의 비등방도 FA(fractional anisotropy)값을 측정 분석한 결과 모든 영역에서 정상 음주자가 알코올 사용 장애 추정자보다 FA값이 낮게 측정되었으며 통계적으로 유의하였다. 본 연구의 측정한 FA결과 값으로 추측하자면 즉, 알코올 사용이 뇌 회백질 부위의 이랑(Gyrus) 계측한 해부학적 미세 구조성 변화에 크게 영향을 미치며 신경 섬유로를 손상시키고 이와 관련된 기능적 이상에 영향을 준다고 할 수 있다.

생약제와 식이섬유로 제조한 다이어트 제제가 대학생의 체중, 체지방, 혈액지방분획 및 배변습관에 미치는 영향 (Effects of Herb and Fiber-Rich Dietary Supplement on Body Weight, Body Fat, Blood Lipid Fractions and Bowel Habits in Collegians)

  • 이복희;조경동
    • 한국식품영양과학회지
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    • 제34권5호
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    • pp.644-651
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    • 2005
  • 본 연구는 생약제와 식이섬유가 주성분인 다이어트 제제가 체중, 체지방, 혈액지질분획 및 배변습관에 미치는 영향을 알아보기 위하여 대학생 자원자 30명을 대상으로 5주 동안 실시하였다. 다이어트 제제는 1일 2회 섭취케 하되 본인의 일상 식사 및 생활양식을 그대로 유지케 하였으며 실험전 설문지 조사를 통한 대상자의 일반환경요인 평가와 식이섭취 평가가 실시되었다. 실험기간 중에는 주 3회 식이일지 작성과 매주 체중을 측정토록 하였고 실험 개시 일과 종료일에는 혈액채취와 신체계측이 실시되었다. 실험대상자의 특성을 보면 중산층 이상으로 평균 나이 21세로 정상체중을 유지하였다. 운동은 절어도 30분간, 주 $1\~2$회 이상하였고 음주율은 매우 높았으나 흡연은 거의 하지 않았다. 식사는 적어도 2끼 이상 먹는 편이나 외식빈도가 많았고 식습관이 불량하였으며 배변횟수는 보통이었으나 변비경험은 비교적 많았다. 영양소 섭취량은 전반적으로 낮았으며 실험개시기에 비해 종료시에 식이섭취 및 영양소 섭취량이 낮은 경향을 보였다. 체중, 체질량지수, 표준체중백분율은 물론 체지방비율, 피부지방두께, 허리둘레, 엉덩이 둘레 및 WHR등은 실험개시시에 비해 종료시 감소하였으며(p<0.05),반면에 근육량의 비율은 유의하게 증가하였다(p<0.05). 한편 혈액 총 콜레스테롤과 중성지방은 유의하게 감소하였으나(p<0.05) HDL-콜레스테롤농도는 변화가 없었고 LDL-콜레스테롤농도는 실험개시시에 비해 종료시 감소하는 경향을 보였다. 혈압은 실험 전과 후에 변화하지 않았다. 배변횟수는 실험 개시기에 비해 종료시에 증가하였다(p<0.05).위의 결과를 종합해 볼 때 본 연구의 생약제와 섬유질로 제조한 다이어트 제제가 체중과 체지방 및 비만관련 신체지표를 유의하게 감소시켰으며, 혈액 중 일부 지방분획과 배변횟수도 바람직하게 변화하였다. 그러나 더욱 통제된 후속 연구가 이뤄져야 할 것으로 사료된다.

투습발수직물과 보온단열소재의 열 및 수분전달 특성 (Thermal and Water Transmission Properties of Vapor Permeable Water Repellent Fabrics and Thermal Insulation Batting Materials)

  • 조길수;최종명;이정주;이선우
    • 한국의류학회지
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    • 제16권2호
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    • pp.237-244
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    • 1992
  • The purpose of this study was to comparatively evaluate thermal and water transmission properties of several vapor permeable water repellent (VPWR) fabrics and synthetic battings that became available in recent years. Five VPWR fabrics evaluated were Hipora in three coating variants, $Gore-Tex^{\circledR}$ and $Aitace^{\circledR}$. Battings evaluated were $Viwarma^{\circledR}$, $Uniwarmr^{\circledR}$, $Thinsulate^{\circledR}$, and $Airseal^{\circledR}$ Thermal resistance and water vapor transmission were measured for each fabric and batting and in all combinations. Thermal resistance at zero and 37 cm/sec air velocity was determined by the Thermo Labo II technique for simultaneously measuring conduction and radiation heat transfer. Water vapor transmission over 24 hours was measured by a modified weight-gain method in a compact humid chamber at conditions simulating the clothing climate under heavy exercise ($40{\pm}1^{\circ}C$, $90{\pm}2\%$ R.H., and 0.5 m/sec air velocity). Fabric porosity was calculated from fiber density and fabric weight, thickness, and area. Thermal resistance results for the fabrics showed the effectiveness of coatings in inhibiting heat transfer. Measurements taken in wind were: $31.1\~37.6\%$ for $Hipora^{\circledR}$ variants; $31.0\%$ for $Gore-Tex^{\circledR}$; and $18.4\%$ for $Aitaca^{\circledR}$ Measurements without wind were higher but in the same order. Water vapor transmission results were in reverse order: $Aitac^{\circledR}$, $8.8 kg/m^{2};\;Gore-Tex^{\circledR}$, 6.4 kg/$m^{2}$; and $Hipora^{\circledR},\;4.4\~6.0\;kg/m^{2}$. In general thermal resistance increased with porosity. For battings, the thermal resistance with wind results were: $Viwarmu^{\circledR}$, $65.0\%;\; Thinsulate^{\circledR}$, $62.0\%$; $Uniwarm^{\circledR}$, $61.0\%$; and $Airseala^{\circledR},\;53.1\%$. Thermal resistance was proportional to thickness. Thermal resistance of fabric-batting combinations were $20\%$ higher than those of the battings only. Water vapor transmission for combinations was mainly affected by that for the VPWR fabric used.

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신경근전기자극치료가 암 환자의 근육 손실에 미치는 영향: 체계적 문헌고찰 (Effects of Neuromuscular Electrical Stimulation on Muscle Wasting with Cancer Patient: A Systematic Review)

  • 박은수;김종희;김수담;김동현;이은정;오민석;유화승
    • 한방재활의학과학회지
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    • 제33권4호
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    • pp.15-29
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    • 2023
  • Objectives The purpose of this study is to systematically review the effects of Neuromuscular Electrical Stimulation treatment on muscle wasting in cancer patients. Methods Randomized controlled trials (RCTs) were searched from seven online databases (PubMed, Cochrane Library, EMBASE, China National Knowledge Infrastructure, Oriental Medicine Advanced Searching Integrated System, Korean studies Information Service System, Research Information Sharing Service. The selected RCTs were evaluated for methodological quality through the Cochrane RoB. Results A total of 126 articles were identified, and 4 randomized controlled trials were selected for systematic review. In one study, it was found that there were statistically significant improvements in the Health-Related Quality of Life (FACTH&N total score, p<0.001). Additionally, significant effects were observed in measurements that represented the size of the quadriceps muscle (cross-sectional area of Vastus lateralis and Rectus femoris, p=0.004), maximum muscle strength, the twitch response of resistance muscles, and voluntary activation (p<0.001). However, no significant differences were observed between the intervention and control groups in terms of quadriceps muscle strength in two other studies (p>0.05). Lastly, while one study showed no significant differences in muscle fiber characteristics between the two groups, it did report significant improvements in measurements related to mitochondria within muscle tissue and muscle strength in the intervention group (p<0.05). Conclusions Neuromuscular electrical stimulation can be a method used to improve muscle strength in muscle wasting of cancer patients, but it is difficult to see its effects as significant compared to other treatments.

Effects of Source of Supplemental Zinc on Performance, Nutrient Digestibility and Plasma Mineral Profile in Cashmere Goats

  • Jia, Wenbin;Zhu, Xiaoping;Zhang, Wei;Cheng, Jianbo;Guo, Cuihua;Jia, Zhihai
    • Asian-Australasian Journal of Animal Sciences
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    • 제22권12호
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    • pp.1648-1653
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    • 2009
  • This experiment was designed to evaluate the effects of source of supplemental zinc (Zn) on performance, nutrient digestibility and plasma mineral profile in Cashmere goats during the cashmere fiber growing period. Twenty-seven Liao Ning Cashmere wether goats (9-10 month of age; initial BW = 19.31${\pm}$0.32 kg) were fed a basal diet (containing 22.3 mg Zn/kg DM) with no supplemental Zn (control) or 20 mg of supplemental Zn/kg of DM from Zn sulfate ($ZnSO_{4}$) or Zn methionine (ZnMet) for 60 days including a 10-day metabolism trial. Average daily gain (ADG) (p<0.05) and gain:feed (G/F) (p<0.05) were increased by Zn supplementation, but no differences were noted between Zn sources (p>0.05). The length and diameter of cashmere fiber did not differ among treatments (p>0.05). Zn supplementation had no influence on digestibility of DM, CP, EE and NDF (p>0.05). However, ADF digestibility in the group supplemented with ZnMet was significantly higher than in other treatments (p<0.05). Plasma Zn was increased (p<0.05) and Cu tended to be decreased (p = 0.057) by Zn supplementation, but no differences were found between Zn sources (p>0.05). Plasma alkaline phosphatase activity (AKP) was improved by Zn supplementation (p<0.05) and was higher in the $ZnSO_{4}$ than the ZnMet group (p<0.05). Zn retention was increased (p<0.05) and apparent absorption rate was decreased (p<0.05) by Zn supplementation. The results indicate that supplementation of 20 mg Zn/kg DM either as $ZnSO_{4}$ or ZnMet in the basal diet containing 22.3 mg Zn/kg DM can improve growth performance in Cashmere goats, and effectiveness of the two sources is similar on performance measurements.