• Title/Summary/Keyword: Fast-setting

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A Study of Priority Setting of Healthy City Project Indicators with the use of AHP Model (계층 분석적 의사결정 방법(AHP)에 의한 건강도시 사업 평가기준의 우선순위 결정에 관한 연구)

  • Park, Myung-Bae;Nam, Eun-Woo;Lee, Hae-Jong;Shin, Taek-Su
    • Korean Journal of Health Education and Promotion
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    • v.25 no.3
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    • pp.139-151
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    • 2008
  • Objectives: Since 2000 interests in Healthy City Project has been growing fast in Korea. Amid this atmosphere, the need for establishing priorities when planning Healthy City Project and carrying forward the plan has arisen. Therefore, this study tries to conduct practical research on the manner of setting priorities of business valuation standard about Healthy City Project. Methods: The research was carried out with Healthy City experts and government official. And in this research the responses of 28 participants among 37 have been taken into consideration due to their consistent responses. Results: The results of Level 1 showed that the "social & environmental approach" accounted for more than the "individual approach". In the case of Level 2, fields resulted in order of "environment", "infrastructure", "behavior", "evaluation and reflection", "disease prevention and rehabilitation", and "setting approach". Conclusions: The findings derived from this study are first, it is feasible to suggest the ways of establishing priorities as to the evaluation standards for the Healthy City Project and second, the results present the ways to proceed in terms of what tasks should be done for the healthy City Project development.

Evaluation of Early-age Properties of Controlled Low Strength Material Using Non-destructive Testing (비파괴 기법을 이용한 유동성 채움재의 초기경화특성 평가)

  • Kim, Dong-Ju;Kim, Sang-Cheol;Han, WooJin;Lee, Jong-Sub;Byun, Yong-Hoon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.62 no.2
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    • pp.31-38
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    • 2020
  • Controlled Low Strength Material (CLSM) has high fluidity and self-compaction characteristics. CLSM is mainly used for backfilling the excavated road. Early-age properties of CLSM should be characterized for fast restoration of the road. In this study, shear wave monitoring and Vicat needle test are performed to investigate the early-age properties of CLSM depending on the setting time. CLSM consists of CSA cement, fly ash, silt and sand, accelerator, and water. Five fly ashes with different chemical properties are used for CLSM samples. The penetration of CLSM along setting time is obtained through the Vicat needle test. A pair of bender elements are placed in a mold for shear wave measurement, and the change in shear waves with the setting time is monitored. The experimental results show that, regardless of the type of fly ash, the penetration depth decreases and the shear wave velocity increases with the setting time. Depending on the type of fly ash, initial and final times and shear wave velocity change. After testing, the correlation between penetration and shear wave velocity is obtained with high coefficient of determination. The shear wave measurement technique using the bender element can be used to identify early-age properties.

A Study on Security Routing using MD5 in MANET Environments (MANET 환경에서 MD5를 이용한 보안 라우팅에 관한 연구)

  • Lee, Cheol-Seung;Jung, Sung-Ok;Lee, Joon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2008.10a
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    • pp.728-731
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    • 2008
  • Recently demands in construction of the stand-alone networks and interconnection between convergence devices have led an increase in research on IETF MANET working group, Bluetooth, and HomeRF working group and much attention has been paid to the application of MANET as a Ubiquitous network which is growing fast. With performance both as hosts and routers, easy network configuration, and fast response, mobile nodes participating in MANET are suitable for Embedded computing, but have vulnerable points, such as lack of network scalability and dynamic network topology due to mobility, passive attacks, active attacks, which make continuous security service impossible. For perfect MANET setting, routing is required which can guarantee security and efficiency through secure routing. In routing in this study, hashed AODV is used to protect from counterfeiting messages by malicious nodes in the course of path 'finding and setting, and disguising misrouted messages as different mobile nodes and inputting them into the network.

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Estimation of Process Parameters Using QFD and Neural Networks in Injection Molding (품질기능전개와 신경망 회로를 이용한 사출성형 공정변수의 예측)

  • Koh, Bum-Wok;Kim, Jong-Seong;Choi, Hoo-Gon
    • IE interfaces
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    • v.21 no.2
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    • pp.221-228
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    • 2008
  • The injection molding process is able to produce high precision manufactures as a single process with fast speed. However, the prices of both the mold and the molding machine are expensive, and the single process is very complex and difficult to compose of the exact relationship between the process setting conditions and the product quality. Therefore, the quality of a molded product often depends on a skillful engineer's operations in the design of both parts and molds. In this paper, the relationship between the process conditions and the defectiveness is built for better manufactures under settings of the appropriate parameters, and so it can reduce the setup time in the injection molding process. Quality Function Deployment (QFD) provides severe defectiveness factors along with the related process parameters. Also, neural networks estimate the relationship between defective factors and process setting parameters, and lead to reduce the defectiveness of molded parts.

Effects of calcium silicate cements on neuronal conductivity

  • Derya Deniz-Sungur;Mehmet Ali Onur;Esin Akbay;Gamze Tan;Fugen Dagli-Comert;Taner Cem Sayin
    • Restorative Dentistry and Endodontics
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    • v.47 no.2
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    • pp.18.1-18.9
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    • 2022
  • Objectives: This study evaluated alterations in neuronal conductivity related to calcium silicate cements (CSCs) by investigating compound action potentials (cAPs) in rat sciatic nerves. Materials and Methods: Sciatic nerves were placed in a Tyrode bath and cAPs were recorded before, during, and after the application of test materials for 60-minute control, application, and recovery measurements, respectively. Freshly prepared ProRoot MTA, MTA Angelus, Biodentine, Endosequence RRM-Putty, BioAggregate, and RetroMTA were directly applied onto the nerves. Biopac LabPro version 3.7 was used to record and analyze cAPs. The data were statistically analyzed. Results: None of the CSCs totally blocked cAPs. RetroMTA, Biodentine, and MTA Angelus caused no significant alteration in cAPs (p > 0.05). Significantly lower cAPs were observed in recovery measurements for BioAggregate than in the control condition (p < 0.05). ProRoot MTA significantly but transiently reduced cAPs in the application period compared to the control period (p < 0.05). Endosequence RRM-Putty significantly reduced cAPs. Conclusions: Various CSCs may alter cAPs to some extent, but none of the CSCs irreversibly blocked them. The usage of fast-setting CSCs during apexification or regeneration of immature teeth seems safer than slow-setting CSCs due to their more favorable neuronal effects.

Strength Development and Permeability of Latex-Modified Concrete with Rapid-Setting Cement (초속경시멘트를 이용한 라텍스개질 콘크리트의 강도 및 투수특성)

  • 윤경구;홍창우;이주형;최상릉
    • Journal of the Korea Concrete Institute
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    • v.14 no.3
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    • pp.299-306
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    • 2002
  • The purpose of this research was to develop a rapid setting cement latex modified concrete (RSLMC) for bridge deck repairing and overlaying. The main experimental variables were latex contents, antifoamer contents and water-cement ratioes. The workability, strength development and permeability were measured as responses. The results showed that latex content increased the slump and reduced the unit water required for same workability. The air contents were measured as 8.0∼9.0% and 2.0∼3.0% without antifoamer and with 1.6∼3.2% of antifoamer, respectively. This resulted in the increment of compressive strength development by 10∼20 %. The flexural strength of RSLMC increased greatly as the latex content increased, but not in compressive strength. The compressive strength and flexural strength developed enough for opening the overlayed RSLMC to the traffic after 3 hours of RSLMC placement. The permeability of RSLMC was evaluated as negligible due to its very low charge passed. Thus, RSLMC could be used at repairing or overlaying the concrete bridge deck at fast-track job sites.

A Study on Distance Relay of Transmission UPFC Using Artificial Neural Network (신경회로망을 이용한 UPFC가 연계된 송전선로의 거리계전기에 관한 연구)

  • Lee, Jun-Kyong;Park, Jeong-Ho;Lee, Seung-Hyuk;Kim, Jin-O
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.18 no.6
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    • pp.37-44
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    • 2004
  • This paper represents a new approach for the protective relay of power transmission lines using a Artificial Neural Network(ANN). A different fault m transmission lines need to be detected classified and located accurately and cleared as fast as possible. However, The protection range of the distance relay is always designed on the basis of fixed settings, and unfortunately these approach do not have the ability to adapt dynamically to the system operating condition. ANN is suitable for the adaptive relaying and the detection of complex faults. The backpropagation algerian based multi-layer protection is utilized for the teaming process. It allows to make control to various protection functions. As expected, the simulation result demonstrate that this approach is useful and satisfactory.

Reactivity of aluminosilicate materials and synthesis of geopolymer mortar under ambient and hot curing condition

  • Zafar, Idrees;Tahir, Muhammad Akram;Hameed, Rizwan;Rashid, Khuram;Ju, Minkwan
    • Advances in concrete construction
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    • v.13 no.1
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    • pp.71-81
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    • 2022
  • Aluminosilicate materials as precursors are heterogenous in nature, consisting of inert and partially reactive portion, and have varying proportions depending upon source materials. It is essential to assess the reactivity of precursor prior to synthesize geopolymers. Moreover, reactivity may act as decisive factor for setting molar concentration of NaOH, curing temperature and setting proportion of different precursors. In this experimental work, the reactivities of two precursors, low calcium (fly ash (FA)) and high calcium (ground granulated blast furnace slag (GGBS)), were assessed through the dissolution of aluminosilicate at (i) three molar concentrations (8, 12, and 16 M) of NaOH solution, (ii) 6 to 24 h dissolution time, and (iii) 20-100℃. Based on paratermeters influencing the reactivity, different proportions of ternary binders (two precursors and ordinary cement) were activated by the combined NaOH and Na2SiO3 solutions with two alkaline activators to precursor ratios, to synthesize the geopolymer. Reactivity results revealed that GGBS was 20-30% more reactive than FA at 20℃, at all three molar concentrations, but its reactivity decreased by 32-46% with increasing temperature due to the high calcium content. Setting time of geopolymer paste was reduced by adding GGBS due to its fast reactivity. Both GGBS and cement promoted the formation of all types of gels (i.e., C-S-H, C-A-S-H, and N-A-S-H). As a result, it was found that a specified mixing proportion could be used to improve the compressive strength over 30 MPa at both the ambient and hot curing conditions.

A Study on MD5 Security Routing based on MANET (MANET 기반 MD5 보안 라우팅에 관한 연구)

  • Lee, Cheol-Seung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.7 no.4
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    • pp.797-803
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    • 2012
  • Recently demands in construction of the stand-alone networks and interconnection between convergence devices have led an increase in research on and much attention has been paid to the application of MANET as a Ubiquitous network which is growing fast. With performance both as hosts and routers, easy network configuration, and fast response, mobile nodes participating in MANET are suitable for Embedded computing, but have vulnerable points, such as lack of network scalability and dynamic network topology due to mobility, passive attacks, active attacks, which make continuous security service impossible. In this study, hashed AODV routing is used to protect from counterfeiting messages by malicious nodes in the course of path finding and setting, and disguising misrouted messages as different mobile nodes and inputting them into the network.

Minimization of Losses in Permanent Magnet Synchronous Motors Using Neural Network

  • Eskander, Mona N.
    • Journal of Power Electronics
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    • v.2 no.3
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    • pp.220-229
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    • 2002
  • In this paper, maximum efficiency operation of two types of permanent magnet synchronous motor drives, namely; surface type permanent magnet synchronous machine (SPMSM) and interior type permanent magnet synchronous motor(IPMSM), are investigated. The efficiency of both drives is maximized by minimizing copper and iron losses. Loss minimization is implemented using flux weakening. A neural network controller (NNC) is designed for each drive, to achieve loss minimization at difffrent speeds and load torque values. Data for training the NNC are obtained through off-line simulations of SPMSM and IPMSM at difffrent operating conditions. Accuracy and fast response of each NNC is proved by applying sudden changes in speed and load and tracking the UC output. The drives'efHciency obtained by flux weakening is compared with the efficiency obtained when setting the d-axis current component to zero, while varying the angle of advance "$\vartheta$" of the PWM inverter supplying the PMSM drive. Equal efficiencies are obtained at diffErent values of $\vartheta$, derived to be function of speed and load torque. A NN is also designed, and trained to vary $\vartheta$ following the derived control law. The accuracy and fast response of the NN controller is also proved.so proved.