• Title/Summary/Keyword: Decrease rate

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The Study on the Gragting Rate MAA onto Silk Fiber by Redox System (Redox계에 의한 MAA Gragt 속도에 관한 연구)

  • 배도규;김종호
    • Journal of Sericultural and Entomological Science
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    • v.39 no.1
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    • pp.62-66
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    • 1997
  • The MAA graftings in silk fiber were done by redox system for the purpose of investingating the effect of ferrous sulfate additive on the grafting rate and graft ratio in various conditions. The graft ratio was higher in redox graft system than in peroxide graft system and the graft ratio in redox graft system was also higher depending on decrease of ferrous sulfate additive. The saturation graft ratio obtained by empirical equation, log X=K/t, was increasing depending on the increase of ferrous sulfate additive. Initial grafting rate was increased but the latter grafting rate was decreased in redox graft system. The effects of liquor ratio(L.R.) on the graft ratio in redox graft system, were higher in high L.R. than in low L.R..

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Experimental Investigation on Separated Flows of Axial Flow Stator and Diagonal Flow Rotor

  • Kinoue, Yoichi;Shiomi, Norimasa;Setoguchi, Toshiaki;Jin, Yingzi
    • International Journal of Fluid Machinery and Systems
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    • v.2 no.3
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    • pp.223-231
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    • 2009
  • Experimental investigations were conducted for the internal flows of the axial flow stator and diagonal flow rotor. Corner separation near the hub surface and the suction surface of stator blade are mainly focused on. For the design flow rate, the values of the axial velocity and the total pressure at stator outlet decrease between near the suction surface and near the hub surface by the influence of corner wall. For the flow rate of 80-90% of the design flow rate, the corner separation of the stator between the suction surface and the hub surface is observed, which becomes widely spread for 80% of the design flow rate. At rotor outlet for 81% of the design flow rate, the low axial velocity region grows between near the suction surface of rotor and the casing surface because of the tip leakage flow of the rotor.

Growth and characterization of lead bromide: application to mercurous bromide

  • Kim, Geug-Tae
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.14 no.2
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    • pp.50-57
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    • 2004
  • Mercurous Bromide ($Hg_2Br_2$) crystals hold promise for many acousto-optic and opto-electronic applications. This material is prepared in closed ampoules by the physical vapor transport (PVT) growth method. We investigate the effects of solutal convection on the crystal growth rate in a horizontal configuration for diffusive-convection conditions and purely diffusion conditions achievable in a low gravity environment. Our results show that the growth rate is decreased by a factor of one-fourth with a ten reduction of gravitational acceleration near y = 2.0 cm. For 0.1 $g_O$ the growth rate pattern exhibits relatively flat which is intimately related to diffusion-dominated processes. The growth rate nonuniformity is regardless of aspect ratio across the interfacial positions from 0 to 1.5. Also, the effect of a factor of the ten reduction in the gravitational acceleration is same to both Ar = 5 and 2. The enlargement in the molecular weight of B from 50 to 500 by a factor 4 causes a decrease in the maximum growth rate by the same factor, indicative of the effect of solutal gradients.

Effect of Cooling Rate on the Prediction of Mechanical Properties of Al Alloys (알루미늄 합금 주물의 냉각 속도에 따른 기계적 성질 예측)

  • Dong, Quan-Zhi;Cho, In-Sung;Hwang, Ho-Young
    • Journal of Korea Foundry Society
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    • v.32 no.5
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    • pp.225-230
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    • 2012
  • In this study, a more practical and simulation approach which can predict the mechanical properties of aluminum alloys is proposed. First, cooling rate, micro-structure, and mechanical properties of casting product were measured through casting experiment. The relation between cooling rate and SDAS decrease exponentially and the linearly decreasing relation exist between SDAS and mechanical properties. Then, the cooling rate was calculated by casting process simulation and the mechanical properties were predicted by using the relations that were derived through experiment. Experimentally measured mechanical properties and predicted values by simulation were in the range of relatively small difference. The mechanical properties of various Al alloys are expected to be predicted by the casting process simulation before actual casting.

Dynamic Sensing-Rate Control Scheme Using a Selective Data-Compression for Energy-Harvesting Wireless Sensor Networks (에너지 수집형 무선 센서 네트워크에서 선택적 데이터 압축을 통한 동적 센싱 주기 제어 기법)

  • Yoon, Ikjune;Yi, Jun Min;Jeong, Semi;Jeon, Joonmin;Noh, Dong Kun
    • IEMEK Journal of Embedded Systems and Applications
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    • v.11 no.2
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    • pp.79-86
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    • 2016
  • In wireless sensor networks, increasing the sensing rate of each node to improve the data accuracy usually incurs a decrease of network lifetime. In this study, an energy-adaptive data compression scheme is proposed to efficiently control the sensing rate in an energy-harvesting wireless sensor network (WSN). In the proposed scheme, by utilizing the surplus energy effectively for the data compression, each node can increase the sensing rate without any rise of blackout time. Simulation result verifies that the proposed scheme gathers more amount of sensory data per unit time with lower number of blackout nodes than the other compression schemes for WSN.

Effect of Strain Rate on Tensile Behavior of Hybrid Fiber Reinforced Cement-based Composites (하이브리드 섬유보강 시멘트복합체의 인장거동에 미치는 변형속도의 영향)

  • Son, Min-Jae;Kim, Gyu-Yong;Lee, Bo-Kyeong;Lee, Sang-Kyu;Kim, Gyeong-Tae;Nam, Jeong-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.05a
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    • pp.122-123
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    • 2017
  • In this study, the tensile behavior of single and hybrid fiber reinforced cement composite according to strain rate was evaluated. Experimental results, in the strain rate 10-6/s, fiber reinforced cement composite showed improved of tensile strength and decrease of strain at peak stress as SSF volume content increased. In the strain rate 101/s, the single and hybrid reinforced cement composite' s tensile properties are improved, because of the improved bond strength between the fiber and matrix. And hybrid fiber reinforced cement composite showed high energy absorption capacity, because the SSF prevented the cracking and fracture of the surrounding matrix when during the HSF pull-out.

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Comparative Study on Internet Pricing : Flat-rate vs. Usage-based (초고속인터넷 요금제 유형에 대한 비교 검토 : 정액제, 종량제)

  • Song, Jae-Do
    • Korean Management Science Review
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    • v.26 no.1
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    • pp.21-35
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    • 2009
  • There is a controversy on Internet pricing, flat-rate vs. usage-based. This study gives a comparative analysis between flat-rate and two-part tariff which is realistic alternative of usage-based pricing. In a basic economic model, two-part tariff based on ISP's cost structure satisfies allocative efficiency and relatively expand the number of subscribers. But the characteristics of Internet service like consumers' uncertainty on cost, measurement cost of traffic and network externality induce increase of cost or decrease of marginal utility. The analysis shows that small impact of these can make flat-rate more efficient.

Result of Radiation Therapy of the Cervix Cancer Stage IIIB (자궁경부암 IIIB 기의 방사선치료 성적)

  • Huh, Seung-Jae
    • Radiation Oncology Journal
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    • v.11 no.1
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    • pp.143-148
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    • 1993
  • From September 1985 through September 1989,56 patients with stage IIIB carcinoma of the cervix were treated with radiation therapy with curative aim. The overall survival at 5 year was $38{\%}$. The survival rate was better for patients treated with combined external radiotherapy and high dose rate intracavitary radiotherapy than with external radiotherapy alone. No significant survival difference was observed between the unilateral and bilateral parametrial extension of the tumor Seventeen patients experienced recurrence within the irradiated field with a loco-regional recurrence rate of $30{\%}$. Ten patients had complications ($18{\%}$). The complications were mild in three, moderate in four, and severe in three patients. A study was made on the relationship between the fraction numbers of intracavitary radiotherapy, vaginal packing and the complication rate, respectively. In this analysis author observed that the significant treatment factor influencing the survival of cervical cancer was the use of intracavitary radiation, and meticulous vaginal packing could decrease the late complication rate of radiotherapy of cervical cancer.

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Investment Effect Analysis of Industrial Firms with a Measurement Standard Laboratory -With Reference to the Statistical Analysis of Product Inferiority Rate- (측정표준실(測定標準室) 설치업체(設置業體)의 투자효과분석(投資效果分析) -제품(製品)의 불량률변동(不良率變動)의 통계적(統計的) 고찰(考察)을 중심(中心)으로-)

  • Kim, Dong-Jin;An, Ung-Hwan
    • Journal of Korean Society for Quality Management
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    • v.18 no.1
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    • pp.84-95
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    • 1990
  • The objective of this study is to understand the effect of measurement-related investment. That is, this study aims at verifying the correlation between the measurement-related investment and inferiority rate of products by statistical analysis. The samples of this study are 376 industrial companies in Korea, and the research data was analysed on inferiority state of industrial companies with a measurement standard laboratory. The analysis was made by the elementary statistics, the correlation analysis and the regression analysis. The results are summarized as follows : First, the inferioriy rate of the industrial companies with a measurement standard laboratory was relatively lower than that of the other companies without the laboratory by statistical significance. Second, the increment on measurement-related investment had a negative correlation with the increment of inferiority rate, and the increase of measurement-related investment showed decrease of the inferiority rate by regression analysis.

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Effect of Chip Breaker Shape and Cutting Condition on the Chip Breaking and Surface Roughness (칩브레이커의 형상과 절삭조건이 칩 절단과 표면거칠기에 미치는 영향)

  • 나기철;태순호;이병곤
    • Journal of the Korean Society of Safety
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    • v.9 no.4
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    • pp.17-28
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    • 1994
  • Chip breaking is important in lathe work for maintaining good surface of the products and safety of operator. The purpose of this study is to investigate the performance of chip breaking and chip shape resulted from the carbide inserts with grooved type and obstruction type chip breaker. Experiments have been performed under the following cutting conditions, (1) constant cutting speed with variable depth of cut and feed rate, (2) constant depth of cut with variable cutting speed and feed rate. Also, the flying distance of chip and it's distribution have been investigated. As a results, good performance of chip breaking can be obtained for small radius of curvature and land width of grooved type chip breaker. And the thickness of chip increase with the increase of feed rate and decrease of cutting speed, and the chip breaking becomes easier with the increase of chip thickness due to the large deformation rate. Obstraction type chip breaker shows better performance of surface roughness than the grooved type. The flying distance of the chips over 90% are less than 1 meter, and the distance decreases as the feed rate decreases.

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