• Title/Summary/Keyword: Rate Law

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Wear Behavior of C/B filled NR Compounds using a Blade-type Abrader (칼날형 마모시험기를 이용한 C/B충전 NR 배합고무의 마모거동)

  • Youn, J.H.;Kaang, Shinyoung
    • Elastomers and Composites
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    • v.49 no.1
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    • pp.73-81
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    • 2014
  • Friction and wear behaviors of natural rubber(NR) compounds were investigated using a blade-type abrader. The effects of temperature, normal load, and rotation speed on wear rate were studied, and wear behaviors of deteriorated compounds were also evaluated. As the rotation speed of specimen and the normal load to specimen increased, the wear rate increased. However, as the experimental temperature increased, the frictional coefficient decreased and the wear rate decreased accordingly. It was found from the wear studies that a power-law relation works between the frictional work input and the wear rate. It was observed that the wear rate dramatically increased by the degradation of the rubber specimen. The wear pattern was developed and the bigger ridge space of the pattern was observed usually in the higher normal load applied. In determining the wear rate of rubber compound, the continuous measurements of wear distance using the blade-type abrader could be successfully used instead of intermittent measurements of wear-loss weight.

A Study of New Technique Development for Creep Evaluation of Heat Resistant Steel Weldment(I) (내열강 용접부의 크리프 평가 신기술 개발에 관한 연구)

  • 유효선;백승세;권일현;이송인
    • Journal of Welding and Joining
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    • v.20 no.6
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    • pp.30-30
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    • 2002
  • It has been reported that the creep characteristics on weldment which is composed of weld metal(W.M), fusion line(F.L), heat-affected zone(HAZ), and base meta(B.M) could be unpredictably changed in severe service conditions such as high temperature and high pressure. However, the studies done on creep damage in power plant components have been mostly conducted on B.M and not the creep properties of the localized microstructures in weldment have been thoroughly investigated yet. In this paper, it is investigated the creep characteristics for three microstructures like coarse-grain HAZ(CGHAZ), W.M, and B.M in X20CrMoV121 steel weldment by the small punch-creep-(SP-Creep) test using miniaturized specimen(l0×10×0.5mm). The W.M microstructure possesses the higher creep resistance and shows lower creep strain rate than the B.M and CGHAZ. In the lower creep load the highest creep strain rate is exhibited in CGHAZ, whereas in the higher creep load the B.M represents the high creep strain rate. The power law correlation for all microstructures exists between creep rate and creep load at 600℃. The values of creep load index (n) based on creep strain rate for B.M, CGHAZ, and W.M are 7.54, 4.23, and 5.06, respectively and CGHAZ which shows coarse grains owing to high welding heat has the lowest creep loade index. In all creep loads, the creep life for W.M shows the highest value.

A Study on New Technique Development for Creep Evaluation of Heat Resistant Steel Weldment (I) (내열강 용접부의 크리프 평가 신기술 개발에 관한 연구(I))

  • 유효선;백승세;권일현;이송인
    • Journal of Welding and Joining
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    • v.20 no.6
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    • pp.754-761
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    • 2002
  • It has been reported that the creep characteristics on weldment which is composed of weld metal(W.M), fusion line(F.L), heat-affected zone(HAZ), and base meta(B.M) could be unpredictably changed in severe service conditions such as high temperature and high pressure. However, the studies done on creep damage in power plant components have been mostly conducted on B.M and not the creep properties of the localized microstructures in weldment have been thoroughly investigated yet. In this paper, it is investigated the creep characteristics for three microstructures like coarse-grain HAZ(CGHAZ), W.M, and B.M in X20CrMoV121 steel weldment by the small punch-creep-(SP-Creep) test using miniaturized specimen($10{\times}10{\times}0.5mm$). The W.M microstructure possesses the higher creep resistance and shows lower creep strain rate than the B.M and CGHAZ. In the lower creep load the highest creep strain rate is exhibited in CGHAZ, whereas in the higher creep load the B.M represents the high creep strain rate. The power law correlation for all microstructures exists between creep rate and creep load at $600^{\circ}C$. The values of creep load index (n) based on creep strain rate for B.M, CGHAZ, and W.M are 7.54, 4.23, and 5.06, respectively and CGHAZ which shows coarse grains owing to high welding heat has the lowest creep loade index. In all creep loads, the creep life for W.M shows the highest value.

Estimation of Parking Requirements of an Apartment (공동주택 주차장 설치기준)

  • Oh, Jae Hak;Park, Junsik
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.4D
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    • pp.451-457
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    • 2009
  • This study verifies parking requirements of an apartment suggested in parking generation law in Korea through analysing the surveyed parking generation rate. It is revealed that the parking requirements according to the gross floor area in parking generation law is similar to the surveyed parking generation rate as an average but the differences of each requirements by region and apartment's size are not significant. Parking generation rate results in strong correlation with the number of household rather than the gross floor area, and the new requirements suggested in this study, based on the number of household, shows significant difference by region and apartment's size, which is consistent with common sense. This study suggests parking requirements of an apartment, based on the number of household, by region and apartment's size for 6 groups. Surveyed parking generation rate of each group is fitted to statistical distribution and the mean value of fitted statistical distribution is suggested as the parking requirements of each group. Parking requirements based on the number of household is easily recognized of its relative and absolute value, and moreover is consistent with the surveyed parking generation rate.

A Study of Nurses' Knowledge, Attitude on the Nurses' Law and Nurses' Perception on the Causes, Coping Patterns with the Nursing Accidents (간호사의 간호관련법에 대한 지식$\cdot$태도 및 간호사고에 대한 원인$\cdot$대처양상에 관한 연구)

  • Mun Heui Ja;Lee Mi Aie
    • Journal of Korean Public Health Nursing
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    • v.13 no.1
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    • pp.41-62
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    • 1999
  • Recently the request of the patients to participate in the medical courses has been expanding due to elevated sense of right on the people's health. merchandised medical treatment by mass supply, human right declaration of the patients, generalized medical informations by the mass media and the change of human relation between the medical personnels and the patients. Under these phenomena the accident by the nurses have been increasing by the area of the nurses having been expanded and their independent roles having been increased. Such nursing accidents are the important subject which the professional occupation of the nurses has been facing but legal protective capability of the nurses has been very weak. Therefore this study has examined the degree of the experience of the nursing accident that happens in the clinical nursing scenes in the general hospital to provide the basic materials for the protection and the counter measures of the nursing accidents. The following is the conclusion based by the above examination. 1) The general characters of the subjects of this study is that they are mostly single in their twenties and graduate from nursing college. Their total clinical career is above 5 years$(44.8\%)$ and their current clinical parts' career is between 1-3 years$(40.1\%)$. So these facts suggest that most hospitals has taken the working rotation policy on nurses. 2) The level of nurses' knowledge on the nursing law is accurate partially but isn't it patially. So it is suggested that nurses need the accurate information and education about the nursing law. But the nurses' attitude is very approved of the establishment of a unilateral nursing law. 3) The relation between the demographic characters of the subjects and their attitudes on the nursing law shows that there is no significant differences except the relation between the attitude 6(the sufficient level of education on nursing law in formal education course) and age. total clinical career. 4) The perception of the nurses shows that the cause of the nursing accident has been due to the heavy work$(78.2\%)$. short of professional knowledge and skill$(60.2\%)$, discordance with Doctors. patients and patients' families. They report the accident to the head nurse first$(81.8\%)$ and within 30 minute$(75.1\%)$. The hour of nursing accident frequently happened is regardless of service hour with $49.4\%$ in response rate. the highest rate. and the nursing accident happens in the night more than the daytime. Even though most nurses think that they are themselves responsible for nursing accident. it is found that the chief cause of the nursing accident is due to the nurses' heavy work$(78.2\%)$. So the causes of nursing accidents is analysed. it may be suggested that the endeavor of hospital and nursing organizations to decrease nursing accidents is very important. 5) The coping patterns of patients with nursing accidents are mostly active attitude such as a violent words$(69\%)$. sue or accusation$(36.4\%)$, monetary compensation $(35.6\%)$ except a understanding cases$(38.7\%)$. But the coping patterns of hospitals with nursing accidents are mostly to investigate the accurate cause.

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A study on the duties of an issuing bank and a negotiating bank and proper law issues with the documentary credit (신용장거래에서 개설은행과 매입은행의 주의의무와 준거법 -대법원 2011. 1. 27. 선고 2009다10249 판결의 평석을 중심으로-)

  • Lee, Jung-Won
    • Journal of Arbitration Studies
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    • v.22 no.1
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    • pp.65-88
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    • 2012
  • Even though there are some discrepancies in detail with the legal characteristic of the issuing bank's notice to the beneficiary of opening of the letter of credit, article 25 of "the Korean Private International Act(hereunder, 'KPIA')" can be applied to the legal relation between the issuing bank and the beneficiary or the negotiating bank. According to article 26 of the KPIA, if there is no agreement between the issuing bank and its opponent party as to the governing law issues, a state's law which has the closest relationship with the subject case may be applied. In the latter case, given the facts that the issuing bank plays important roles in every phasis of the sale of goods by the letter of credit, a law of place where the issuing bank's business premises is situated(the $lex$ $situs$) can be the applicable law. Meanwhile, "the Korean Supreme Court(hereunder 'KSC')" held that the beneficiary or the negotiating bank can claim any damages arising due to the refusal or deferred payment of the issuing bank, and the law which governs the above mentioned situation is the same law that is applicable to the legal relation between the issuing bank and the beneficiary or the negotiating bank. The main reason of the KSC's ruling is that the nature of the legitimate interest rate which is stated in article 3 of "the Act on Special Cases concerning Expedition etc. of Legal Proceeding(hereunder 'ASCELP')" is substantial matters, not procedural. Taking into account, however, that the main object of ASCELP lies in expedition of legal proceeding, prompt realization of people's rights and duties, and prevention of delayed legal proceeding, it is recommendable that ASCELP, instead of the law applicable to the legal relation between the issuing bank and the beneficiary or the negotiating bank, should be applied to the cases in which the malicious debtor's only and main purpose is delaying the legal proceedings. On the other hand, even if the issuing bank's duty of examination of the documents which were tendered by the beneficiary or the negotiating bank is restricted to the formality and strict conformity of the documents and not the substantiality of the documents, the issuing bank still has to examine the documents with due diligence that is required to the banks whose main business is sales of documents, not the real goods. In this regard, under the circumstances where the document lacked the regularity and/or the formality on its face because of the forgery of the document and where it was expected that an ordinary banker might have easily found any faults with the document, the issuing bank must compensate any parties for damages when it pays money without due diligence as a banker who engaged in the sales of documents.

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The Rate Dependent Deformation Behavior of AISI Type 304 Stainless Steel at Room Temperature (304 스테인리스강의 점소성 특성에 관한 연구)

  • Ho, Kwang-Soo
    • Transactions of Materials Processing
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    • v.16 no.2 s.92
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    • pp.101-106
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    • 2007
  • Uniaxial displacement controlled tests were performed on annealed Type 304 stainless steel at room temperature. A servo-controlled testing machine and strain measurement on the gage length were employed to measure the response to a given input. The test results exhibit that the flow stress increases nonlinearly with the strain rate and the relaxed stress at the end of the relaxation periods depends strongly on the strain rate preceding the relaxation test. The rate-dependent inelastic deformation behavior is simulated using a new unified viscoplasticity model that has the rate-dependent format of nonlinear kinematic hardening rule, which plays a key role in modeling the rate dependence of relaxation behavior. The model does not employ yield or loading/unloading criteria and consists of a flow law and the evolution laws of two tensor and one scalar-valued state variables.

High Temperature Deformation Behavior of Rapid-Solidification Processed Al-18Si Alloy (급냉응고된 과공정 Al-Si합금의 고온변형특성에 관한 연구)

  • 김성일
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2000.04a
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    • pp.183-186
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    • 2000
  • The high temperature deformation behavior of spray-formed Al-19wt%Si-1.87wt%Mg-0.085wt.%Fe alloy was studied by torsion testing in the strain rate range of 0.001-1 sec-1 and in the temperature range of 300-500 $^{\circ}C$. The relationship between stress temperature and strain rate is expressed using the Power law. the behavior of dynamic recrystallization is showed in 300-35$0^{\circ}C$, 1-0.1sec-1 and the behavior of dynamic recovery is showed in 450-50$0^{\circ}C$, 0.01-0.001sec-1 The size of Si particles is mall when the temperature is low and the strain rate is high. The strain rate sensitivity(m) and the apparent activation energy(Q) indicate the dependence on strain rate and temperature for flow stress respectively. The hot ductility is high when m is high and Q is low. The maps of strain rate sensitivity and apparent activation energy suggest the optimum processing conditions.

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A Generalized Viscoplasticity Theory Based on Overstress (과응력에 기초하여 일반화된 점소성 이론)

  • Ho, Kwang-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.10
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    • pp.1953-1960
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    • 2002
  • The viscoplasticity theory based on overstress, one of the unified state variable theories, is generalized to model zero (no influence of loading rate) and negative (flow stress decreases with loading rate) as well as positive (flow stress increases with loading rate) rate sensitivity in a consistent way. On the basis of the long-time asymptotic solution the different types of rate sensitivity are classified with respect to an augmentation function that is introduced in the evolution law fur a state variable equilibrium stress. The theory predicts normal relaxation and creep behaviors even if unusual rate sensitivity is modeled. The constitutive model fir the behavior of a modified 9Cr-1 Mo steel at various temperatures is then compared with experimental data found in the literature.

A Study of Tax Payment Consciousness Influence for Increase of Additional Tax Rate (가산세율(加算稅率) 인상(引上)에 대한 납세의식(納稅意識)의 영향(影響)에 관한 연구(硏究))

  • Doo, Chang-Ho
    • Journal of Industrial Convergence
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    • v.8 no.1
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    • pp.49-64
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    • 2010
  • Penalty tax of basic law that has been revised in December 30, 2006 has been amended to tax 40 percent on no report and under-reporting in unjustifiable way. This revision is a punitive regulation that reflects the national tax service's will to not sit back and watch taxpayers' intentional tax evasion by imposing a heavier tax burden, and it raised penalty tax rate that has been applied leniently compared to foreign countries. Therefore, this study examines how changes in penalty tax rate affected faithful tax report and in what level the punitive penalty tax rate should be legislated so that the effect of the penalty tax rate can be maximized by performing empirical analysis on the effect on income tax rate reporting standard of self-employed businesses before and after the time the penalty tax rate increased dramatically from 33.3% to 300% based on the items.

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