• Title/Summary/Keyword: ppc

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Safety Assessment of Cracked Prestressed concrete Cylinder Pipes (균열손상을 입은 프리스트레스트 콘크리트관의 안전도분석)

  • Kim, Young Jin;Lee, Sang Min;Lee, Ki Seong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.2 no.3
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    • pp.168-175
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    • 1998
  • This study investigated the structural performance of the precast prestressed cylinder pipe having cracked under construction. The finite element formulation of PPC pipe incorporates Asoild elements using SAP90 program and the radial prestress force was transformed into the eqivalent external pressure. The analytical results were compared with the experimental results of full scale tests on PPC pipes subjected to static load. It is shown that the proposed modelling gives a realistic represention of the actual behavior. The analytical procedure is used to calculate the stresses in the PPC pipes and to check the crack opening under various situations such as bedding angle, earth pressure, and earth cover. Finally, the proposed modelling and analytical procedure should be especially usefull for the safety assessment of the PPC pipes under general loading conditions.

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Synthesis and Characterization of Waterborne Polyurethane for Water Resistance (내수성 향상을 위한 수성 폴리우레탄의 합성 및 특성)

  • Choi, Min Ji;Jeong, Boo Young;Cheon, Jung Mi;Park, Kuenbyeol;Chun, Jae Hwan
    • Journal of Adhesion and Interface
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    • v.18 no.1
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    • pp.8-12
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    • 2017
  • In this study, waterborne polyurethane was synthesized with polyester polyol, poly(propylene carbonate) (PPC), 4,4-dicyclohexylmethane diisocyanate ($H_{12}MDI$) and dimethylol propionic acid (DMPA) to improve the water resistance. The properties of the synthesized waterborne polyurethane using poly(propylene carbonate) (WPUP) was evaluated through FT-IR, GPC, DSC and UTM. The mechanical properties were increased with the increase in the amount of PPC. When the ratio of polyester polyol to poly(propylene carbonate) is 9:1, the highest water resistance was showed.

Optimization of Redundancy by using Genetic Algorithm for Reliability of Plant Protection Controller (플랜트 보호 제어기의 신뢰도분석과 유전알고리듬을 이용한 다중성의 최적화)

  • Yu, Dong-Wan;Kim, Dong-Hun;Park, Hui-Yun;Gu, In-Su;Seo, Bo-Hyeok
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.49 no.9
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    • pp.504-511
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    • 2000
  • The reliability of system is to become a important concern in developed industry. The controller based on the reliability is so important position. PPC(Plant Protection Controller) is for plant protection and human life by fault detection and control action against the transient condition of plant. The protection system of the nuclear reactor and chemical reactor are representative of PPC. This paper presents analysis of PPC relaibility formal problem statement of optimal redundancy based on the reliability for PPC. And the problem is optimized by genetic algorithm, The genetic algorithms is useful algorithm in case of large searching complex gradient existence local minimum. The genetic algorithms is useful algorithm is case of large searching complex gradient existence local minimum. The ability and effectiveness of the proposed optimization is demonstrated by the target reliability of one channel. PPC. using the failure rate based on the MIL-HDBK-217

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Fatigue performance monitoring of full-scale PPC beams by using the FBG sensors

  • Wang, Licheng;Han, Jigang;Song, Yupu
    • Smart Structures and Systems
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    • v.13 no.6
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    • pp.943-957
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    • 2014
  • When subjected to fatigue loading, the main failure mode of partially prestressed concrete (PPC) structure is the fatigue fracture of tensile reinforcement. Therefore, monitoring and evaluation of the steel stresses/strains in the structure are essential issues for structural design and healthy assessment. The current study experimentally investigates the possibility of using fiber Bragg grating (FBG) sensors to measure the steel strains in PPC beams in the process of fatigue loading. Six full-scale post-tensioned PPC beams were exposed to fatigue loading. Within the beams, the FBG and resistance strain gauge (RSG) sensors were independently bonded onto the surface of tensile reinforcements. A good agreement was found between the recorded results from the two different sensors. Moreover, FBG sensors show relatively good resistance to fatigue loading compared with RSG sensors, indicating that FBG sensors possess the capability for long-term health monitoring of the tensile reinforcement in PPC structures. Apart from the above findings, it can also be found that during the fatigue loading, there is stress redistribution between prestressed and non-prestressed reinforcements, and the residual strain emerges in the non-prestressed reinforcement. This phenomenon can bring about an increase of the steel stress in the non-prestressed reinforcement.

Small and Medium Business Workers' Positive Psychological Capital, Life Satisfaction, and Innovative Work Behavior

  • Yang, Hoe-Chang;Cho, Hee-Young
    • Journal of Distribution Science
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    • v.13 no.7
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    • pp.25-31
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    • 2015
  • Purpose - This study aims to measure the influence of the positive psychological capital (PPC) of business workers by using innovative work behavior (IWB) and the influence of Leader-member exchange (LMX) and Member-member exchange (MMX) in this relation and investigating the directional efforts of small and medium company leaders and members. Research Design, Data, and Methodology - This study selects PPC as an integrated superior concept to establish research models and hypotheses of the influence of PPC on IWB, and the influence of LMX and MMX in these relations. Of the questionnaires distributed, 373 valid questionnaires were collected in total. Results - It was confirmed that the PPC of workers has a statistically significant influence on LMX, MMX, and IWB. Moreover, LMX and MMX have similar influence on worker life satisfaction with life satisfaction and innovative work behavior having different dimensions. Conclusion - To enhance IWB, worker PPC is very important as it has significant influence on the relations with leaders. However, it is also notable that positive relations with colleagues did not influence IWB.

A Study on Design of High-Speed Parallel Multiplier over GF(2m) using VCG (VCG를 사용한 GF(2m)상의 고속병렬 승산기 설계에 관한 연구)

  • Seong, Hyeon-Kyeong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.3
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    • pp.628-636
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    • 2010
  • In this paper, we present a new type high speed parallel multiplier for performing the multiplication of two polynomials using standard basis in the finite fields GF($2^m$). Prior to construct the multiplier circuits, we design the basic cell of vector code generator(VCG) to perform the parallel multiplication of a multiplicand polynomial with a irreducible polynomial and design the partial product result cell(PPC) to generate the result of bit-parallel multiplication with one coefficient of a multiplicative polynomial with VCG circuits. The presented multiplier performs high speed parallel multiplication to connect PPC with VCG. The basic cell of VCG and PPC consists of one AND gate and one XOR gate respectively. Extending this process, we show the design of the generalized circuits for degree m and a simple example of constructing the multiplier circuit over finite fields GF($2^4$). Also, the presented multiplier is simulated by PSpice. The multiplier presented in this paper uses the VCGs and PPCS repeatedly, and is easy to extend the multiplication of two polynomials in the finite fields with very large degree m, and is suitable to VLSL.

An Experimental Study on the Thermal Physiological Response in the Pesticide Proof Clothing Textile Materials for a Fruit-grower (과수용 농약방제복 소재 특성에 따른 인체생리반응에 관한 연구)

  • Hwang, Kyoung-Sook;Kim, Kyung-Ran;Lee, Kyung-Suk;Kim, Hyo-Cher;Baek, Yoon-Jeong
    • Journal of the Korean Society of Clothing and Textiles
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    • v.32 no.11
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    • pp.1792-1801
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    • 2008
  • This study was to develope the pesticide-proof clothes(PPC) for fruit-grower which has been well known over applied agricultural chemicals. The ergonomic evaluation of PPC were tested in two ways. Male adults volunteered the tests to evaluate the safety to pesticide in the field and the thermal comforts in the climate-chamber($30^{\circ}C$, 60%R.H.). PPC were made of 4 different fabrics. Two of them were on the market(coated non-woven and coated nylon). Others were water-repellent treatment and coated waterproof film by developed polyester. The field study was conducted for farmers growing apples to evaluate pesticide exposure. In this experiment, we collected data with patch test on the head, chest, back, right upperarm, right forearm, left thigh and left calf. From the results, the developed PPC showed the more excellent comfort than an existing PPC with nylon coated polyurethane. But the developed PPC of water-repellent fabric was penetrated into the PPC. Therefore, we designed the functional pesticide-proof clothes of 2 different developed polyester fabrics(water-repellent treatment in chest, abdomen, the lower of back, waist, and calf; coated waterproof film in head, shoulder, the upper of back, the crotch, hip, upper arm and thigh).

Effects of Pear Phenolic Compound on Blood Pressure, Plasma Renin, ANP and Cardiac Hypertophy in Hypertensive RAT Induced by 2K1C (배 추출 Phenolic compound 투여가 흰쥐의 혈압 변화, 혈장 Renin, ANP 및 Cardiac hypertrophy에 미치는 영향)

  • Na Chang Su;Yun Dae Hwan;Choi Dong Hee;Kim Jeong sang;Jo Chun Hwa;Eun Jong Bang
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.17 no.2
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    • pp.363-367
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    • 2003
  • Oriental pear was used as treatment of asthma, control of blood pressure tonic medicine vasoaction, diabetes in oriental medicine. In this study, it was investigated that pear phenolic compound effects on cardiovascular system as blood pressure and renin and atrial natriuretic peptide(ANP) in plasma, Cardiac hypertrophy. The experiments were performed on Sprague Dawley rats, 2K1C hypertension model was prepared by constricting the left renal artery with a sliver clip. Animals were then divided into four groups, 5mg/Kg(PPC-A) 10mg/Kg(PPC-B) 15mg/Kg(PPC-c) and control group. Pear phenolic compound solution were supplied with them for 3weeks, a day's interval. The results are that The blood pressure was significantly decreased at 15days in PPC-A group than control group. The plasma ANP was increased in PPC-A and PPC-C group, and cardiac hypertrophy was significantly decrease in PPC-C group compared with control group.

The Role of Brain and Feeding Response on Lysine Devoid Diet (Lysine 결핍에 따른 섭식반응과 뇌의 역할)

  • Kim, C.H.
    • Journal of Animal Science and Technology
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    • v.44 no.2
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    • pp.221-232
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    • 2002
  • This study was conducted to investigate the effects of deficiency of essential amino acid in diet on feed intake and concentrations of free amino acid in plasma and brain(prepyriform cortex, PPC), and thereby to know the brain area engaged in the mechanism of feed intake regulation. In all trials, experimental diets were formulated with pure amino acid mixture to level of 15% nitrogen. Rats were trained to eat a single meal for 6 hours daily(meal feeding, 17:00-21:00). Feed intake and body weight were measured hourly on and after 7th day of feeding. In Exp. 1, feed intake and body weight were measured every hour, and the free amino acid concentrations of plasma and PPC were analysed at 0, 1, 2, 3 and 6 h on the 11th day of feeding. In Exp. 2, the complete diet was replaced with lysine devoid diet at the 11th day, and feed intake, body weight and free amino acid concentrations in plasma and PPC were samely measured on Exp. 1. In Exp. 1, feed intake on complete diet was self-sufficiented to daily feed intake level(15g/day) from the 7th day. Free amino acid concentrations of plasma and PPC at the 11th day were plateau at 1 hour after feeding. In Exp. 2, feed intake was quickly reduced by the diet replacement(P$<$0.05), and the free lysine concentration of plasma and PPC was also significantly decreased at 2 hour after feeding. However, cumulative feed intake was significantly decreased at 4 hour after feeding. These results may indicate that the concentrations of free lysine in plasma and PPC, under the condition of devoided lysine in diet, were more quickly droped than the reduction of feed intake rate. Hence, it is expected that PPC in brain might be a part of response area for limited amino acid.

Mechanical Properties of Permeable Polymer Concrete for Permeability Pavement with Recycled Aggregate and Fiber Volume Fraction (재생골재 및 섬유 혼입률에 따른 포장용 투수성 폴리머 콘크리트의 역학적 특성)

  • Sung, Chan-Yong;Kim, Young-Ik
    • Journal of The Korean Society of Agricultural Engineers
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    • v.52 no.1
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    • pp.69-77
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    • 2010
  • Research on permeable pavement like asphalt and concrete pavement with porous structure has been increasing due to environmental and functional need such as reduction of run off and flood, and increase and purification of underwater resource. This study was performed to evaluate permeability, strengths and durability of permeable polymer concrete (PPC) using recycled aggregate that is obtained from waste concrete. Also, 6mm length of polypropylene fiber was used to increase toughness and interlocking between aggregate and aggregate surrounded by binder. In the test results, regardless of kinds of aggregates and fiber contents, the compressive strength and permeability coefficient of all types of PPC showed the higher than the criterion of porous concrete that is used in permeable pavement in Korea. Also, strengths of PPC with increase polypropylene fiber volume fraction showed slightly increased tendency due to increase binder with increase of fiber volume fraction. The weight reduction ratios for PPC after 300 cycles of freezing and thawing were in the range of 1.6~3.8 % and 2.2~5.6 %, respectively. The weight change ratio was very low regardless of the fiber volume fraction and aggregates. The weight reduction ratios of PPC with fiber and aggregate were in the range of 1.3~2.7 % and 2.2~3.2 % after 13 weeks and was very low regardless of the fiber volume fraction and aggregates.