• Title/Summary/Keyword: power law process

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Error Check Algorithm in the Wireless Transmission of Digital Data by Water Level Measurement

  • Kim, Hie-Sik;Seol, Dae-Yeon;Kim, Young-Il;Nam, Chul
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1666-1668
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    • 2004
  • By wireless transmission data, there is high possibility to get distortion and lose by noise and barrier on wireless. If the data check damaged and lost at receiver, can't make it clear and can't judge whether this data is right or not. Therefore, by wireless transmission data need the data error check algorithm in order to decrease the data's distortion and lose and to monitoring the transmission data as real time. This study consists of RF station for wireless transmission, Water Level Meter station for water level measurement and Error check algorithm for error check of transmission data. This study is also that investigation and search for error check algorithm in order to wireless digital data transmission in condition of the least data's damage and lose. Designed transmitter and receiver with one - chip micro process to protect to swell the volume of circuit. Had designed RF transmitter - receiver station simply by means of ATMEL one - chip micro process in the systems. Used 10mW of the best RF power and 448MHz-449MHz on frequency band which can get permission to use by Frequency Law made by Korean government

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HIP Diffusion Bonding of Two Types of Superalloys for Engine Blisk Applications (엔진 블리스크 제조를 위한 초내열합금 이종재의 HIP Diffusion Bonding)

  • 나영상;황형철;염종택;권영삼;박노광
    • Transactions of Materials Processing
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    • v.12 no.1
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    • pp.60-65
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    • 2003
  • HIP diffusion bonding of Ni-based superalloys, cast Mar-M247 (MM247) and Udimet 720 (U720) powder, was experimentally and numerically studied. Subsolvus HIP treatment was optimized by investigating the variations of high temperature tensile properties of HIP-bonded specimens with powder size, HIP'ing time, etc. While the tensile strength at high temperatures showed no detectable changes, the tensile elongation and reduction in area were slightly increased as the powder size decreased from -140 mesh to -270 mesh. While as-HIP'ed U720 showed a high tensile strength comparable to that of lorded U720 alloy, the HIP diffusion-bonded specimen showed a strength lower than the forged U720 alloy and the cast MM247 alloy The increase of HIP'ing tune from 2 hours to 3 hours resulted in a rapid risc of tensile strength and elongation due to the disappearence of microvoids in the cast MM247. FEM simulation for HIP process was conducted by applying the McMeeking micromechanical model, which uses power-law creep model as constitutive equations. ABAQUS user subroutine CREEP with an implemented microscopic model was used for the simulation. Numerical simulation was shown to be essential for the near-net shape manufacturing as well as the HIP process optimization.

Performance assessment of {tris (2-methyl-1-aziridinyl) phosphine oxide} photocatalytic mineralization in a falling film reactor, using response surface methodology

  • Saien, J.;Raeisi, A.;Soleymani, A.R.;Norouzi, M.
    • Advances in environmental research
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    • v.1 no.4
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    • pp.289-304
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    • 2012
  • Tris (2-methyl-1-aziridinyl) phosphine oxide (MAPO) is extremely poisonous and persistent in aqueous media. An efficient UV/nano$TiO_2$ process was employed for its mineralization in a high duty falling film photo-reactor based on an experimental design scheme that considers interactions between the main variables. The influencing variables and their range were determined with preliminary studies. The results show substrate mineralization to some extent under mild conditions of: T = $30^{\circ}C$, pH = 8.5, $[MAPO]_0=60\;mg\;L^{-1}$ and $[TiO_2]=110\;mg\;L^{-1}$. The relative importance of the influencing parameters were initial pH > temperature > $[MAPO]_0$ > [$TiO_2$]; while the interdependence of all the parameters was significant. Accordingly, a reduced quadratic expression was developed. Meanwhile, mineralization kinetic studies, based on chemical oxygen demand, revealed a power law model with order of 2.6 during process time until 150 min.

Development of Finite Element Program for Analyzing Springback Phenomena of Non-Isothermal Forming Processes for Aluminum Alloy Sheets (Part2 : Theory & Analysis) (알루미늄 합금박판 비등온 성형공정 스프링백 해석용 유한요소 프로그램 개발 (2부 : 이론 및 해석))

  • ;;R.H. Wagoner
    • Transactions of Materials Processing
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    • v.12 no.8
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    • pp.710-717
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    • 2003
  • The implicit, finite element analysis program for analyzing the springback in the warm forming process of aluminum alloy sheets was developed. For the description of planar anisotropy in warm forming temperatures, Barlat's yield function is employed, and the power law type constitutive equation is used in terms of working temperatures for the depiction of work hardening in high temperatures. Also, Jetture's 4-node shell elements are introduced for reflecting the mechanical behavior of aluminum alloy sheet and the non-steady heat balance equations are solved for considering heat gain and loss during the forming process. For the springback evaluation, Newton-Raphson iteration method is introduced for overcoming the geometric nonlinearlity problem. In order to verify the validity of the FEM program developed, the stretching bending and springback processes are simulated. Though springback analysis results are slightly bigger than experimental ones, they have the same trend of the decreasing springback as the forming temperature increases.

Numerical Analysis of Extrusion Processes of Particle Filled Plastic Materials Subject to Slip at the Wall (미끄럼현상을 갖는 입자충전 플라스틱재료의 압출공정 수치해석)

  • 김시조;권태헌
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.10
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    • pp.2585-2596
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    • 1994
  • Many particle filled materials like Poweder/Binder mixtures for poweder injection moldings, have complicated rheological behaviors such as an yield stress and slip phenomena. In the present study, numerical simulation programs via a finite element method and a finite difference method were developed for the quasi-three-dimensional flows and the two-dimensional flow models, respectively, with the slip phenomena taken into account in terms of a slip velocity. In order to qualitatively understand the slip effects, typical numerical results such as vector plots, pressure contours in the cross-channel plane, and isovelocity controus for the down-channel direction were discussed with respect to various slip coefficients. Slip velocities along the boudary surfaces were also investigated to find the effects of the slip coefficient and processing conditions on the overall flow behavior. Based on extensive numerical calculations varying the slip coefficients, pressure gradient, aspect ratio, and power law index, the screw characteristics of the extrusion process were studied in particular with comparisons between the slip model and non-slip model.

Development of Finite Element Program for Analyzing Springback Phenomena of Non-isothermal Forming Processes for Aluminum Alloy Sheets (Part II : Theory & Analysis) (알루미늄 합금박판 비등온 성형공정 스프링백 해석용 유한요소 프로그램 개발 (2부 : 이론 및 해석))

  • Keum Y. T.;Han B. Y.;Wagoner R.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.08a
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    • pp.13-20
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    • 2003
  • The implicit, finite element analysis program for analyzing the springback in the warm forming process of aluminum alloy sheets was developed. For the description of planar anisotropy in warm forming temperatures, Barlat's yield function is employed, and the power law type constitutive equation is used in terms of working temperatures fur the depiction of work hardening in high temperatures. Also, Jetture's 4-node shell elements are introduced for reflecting the mechanical behavior of aluminum alloy sheet and the non-steady heat balance equations are solved for considering heat gain and loss during the forming process. For the springback evaluation, Newton-Raphson iteration method is introduced for overcoming the geometric nonlinearlity problem. In order to verify the validity of the FEM program developed, the stretching bending and springback processes are simulated. Though springback analysis results are slightly bigger than experimental ones, they have the same trend of the decreasing springback as the forming temperature increases.

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The Current Status of the Discussions on International Norms Related to Space Activities in the UN COPUOS Legal Subcommittee (우주활동 국제규범에 관한 유엔 우주평화적이용위원회 법률소위원회의 최근 논의 현황)

  • Jung, Yung-Jin
    • The Korean Journal of Air & Space Law and Policy
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    • v.29 no.1
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    • pp.127-160
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    • 2014
  • The UN COPUOS was established in 1959 as a permanent committee of the UN General Assembly with the aims to promote international cooperation in peaceful uses of outer space, to formulate space-related programmes within the UN, to encourage research and dissemination of information on space, and to study legal problems arising from the outer space activities. Its members have been enlarged from 24 members in 1959 to 76 in 2014. The Legal Subcommittee, which has been established under COPUOS in 1962 to deal with legal problems associated with space activities, through its first three decades of work has set up a framework of international space law: the five treaties and agreements - namely the Outer Space Treaty, Rescue Agreement, Liability Convention, Registration Convention, Moon Agreement - and the five declarations and legal principles. However, some sceptical views on this legal framework has been expressed, concerning the applicability of existing international space law to practical issues and new kinds of emerging space activities. UNISPACE III, which took place in 1999, served as a momentum to revitalize the discussions of the legal issues faced by the international community in outer space activities. The agenda of the Legal Subcommittee is currently structured into three categories: regular items, single issue/items, and items considered under a multi-year workplan. The regular items, which deal with basic legal issues, include definition and delimitation of outer space, status and application of the five UN treaties on outer space, and national legislation relevant to the peaceful exploration and use of outer space. The single issues/items, which are decided upon the preceding year, are discussed only for one year in the plenary unless renewed. They include items related to the use of nuclear power sources in outer space and to the space debris mitigation. The agenda items considered under a multi-year work plan are discussed in working group. Items under this category deal with non-legally binding UN instruments on outer space and international mechanism for cooperation. In recent years, the Subcommittee has made some progress on agenda items related to nuclear power sources, space debris, and international cooperation by means of establishing non-legally binding instruments, or soft law. The Republic of Korea became the member state of COPUOS in 2001, after rotating seats every two years with Cuba and Peru since 1994. Korea's joining of COPUOS seems to be late, in considering that some countries with hardly any space activity, such Chad, Sierra Leone, Kenya, Lebanon, Cameroon, joined COPUOS as early as 1960s and 1970s and contributed to the drafting of the aforementioned treaties, declarations, and legal principles. Given the difficulties to conclude a treaty and un urgency to regulate newly emerging space activities, Legal Subcommittee now focuses its effort on developing soft law such as resolutions and guideline to be adopted by UN General Assembly. In order to have its own practices reflected in the international practices, one of the constituent elements of international customary law, Korea should analyse its technical capability, policy, and law related to outer space activities and participate actively in the formation process of the soft law.

A Study on the Efficiency of the North Korean Foreign Economy Arbitration Law (북한 대외경제중재법의 실효성 고찰)

  • Kim, Suk-Chul
    • Journal of Arbitration Studies
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    • v.18 no.1
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    • pp.167-184
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    • 2008
  • The economic cooperation between the South and North Koreas is a very important issue for the unification and economic development of both Koreas. In order to reach a successful economic cooperation, there is a need to coordinate the differences of the two countries before unification. The economic cooperation and the cooperation in other sectors will be followed by the entire unification. It is necessary to prepare a mechanism that could peacefully solve the conflicts and disputes that could arise during the actual process of cooperation, which will secure stable investments and trades. The study on the possibility of introducing the arbitration system as a conflict solving mechanism between the two Koreas is a very important subject, and the basis of this study is on the examination of the arbitration laws of North Korea. Therefore, the study on the efficiency of the North Korean arbitration laws on foreign economy is studying the possibility of a systematical solution to economic conflicts between the South and North Koreas. The problems and possible solutions of the North Korean foreign economy arbitration laws are summarized as follows. First, juridical cooperation system for both South and North courts of justice needs to be set up to smoothly carry out the main procedures. Mutual correspondence and telecommunication needs to be guaranteed, also remittance and the movement of goods shall precede. Second, the free liquidation of businesses by unit and the individual and independent management of wealth of the North Korean economic bodies, organizations and businesses shall precede to independently liquidate wealth and thus make arbitration possible. Third, amendments in the North Korea's foreign economy arbitration law shall be made to some parts of regulations on arbitration agreements and specific contents of written arbitration agreements to avoid conflicts regarding arbitration agreement. Fourth, the members of the North Korean arbitration committee shall impartially manage the committee only without taking the role of arbitrator, and the clause that allows the North Korean committee to nominate the arbitrator shall be erased. In case an agreement regarding the number of arbitrators is not reached, the three arbitrators general rule shall be applied. In case of requests from any of the parties, a third country arbitrator nomination shall be guaranteed. Also, the requested arbitrator by the party shall be nominated with the cooperation of the court. Fifth, the trial in case of non-appearance or written trial shall be added to the North Korean law in to prevent intended negligence or evasion. Sixth, regulations regarding the court's investigation of evidence shall be added to the North Korean law to make fair arbitration possible in case that government power is needed in order to investigate evidence. Seventh, provisions regarding majority decision shall be added in the North Korean law in the impossibility of unanimous decisions, and the certified system in the arbitration committee official text shall be erased to prevent arrogation and assure the power of the decision made by the arbitration government. Eighth, as "the wrong decision approved" reason for cancellation of arbitration in the North Korean law includes the content of the decision made by the arbitrator could lead to uselessness of arbitration, amendment will be necessary to limit it to legitimacy of the arbitration agreement and wrong procedures. It is hoped that this thesis will be of important use in understanding the issues on the workability and the solutions to the South and North Koreas' arbitration that could be presented during the negotiations for the countries' economic cooperation.

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Analysis Pregnant Women's Perceived Delivery Experiences According to Delivery Supporters (산모가 인지한 분만지지자별 분만경험분석)

  • Shin, Gi-Soo
    • Women's Health Nursing
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    • v.2 no.1
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    • pp.5-24
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    • 1996
  • The Delivery Process can be viewed as one of the developmental crisis that forces the majority of women. During the labor and delivery process the women may face a variety of problems and pain with all its subjectivity. This developmental crisis may lead a pregnant women to have a negative experience in delivery. For nurses, to help to pregnant women check with the crisis and perceived support and to positive experience. This study intended to analyze the pregnant women's delivery experience according to supporter during labor. The subjects for this study were 45 pregnant women who had normal delivery without complications, within 37 to 42 weeks of pregnancy. Data Collection was done from April 24th to May 20th 1995 by two instruments, a support measurement scale and a delivery experience measurement scale which were consisted it 18-items scale developed by researcher. The data was analyzed by SPPS program using descriptive statistic Kruskal-Wallis one way analysis and Spearman Correlation Coefficient. The result of this study are as follows. 1. Support distribution by support contents is shown is order of holding the hands (97.8%), help to urination(86.7%), bed arrangement(57.8%), massaging the arms and legs(55.6%), changes in posture(44.4%), teaching how to produce power(44.4%), while emotional support is disclosed in order of sympathy(97.8%), encouragement(82.2%), hearing the needs(60.0%), However, information support was as low as less than 33.3%. 2. The extent of delivery experience a Pregnant woman perceives is revealed in order of a sense of comfortableness(44%), satisfaction(43.2%), reduction of fear(43.2%), familiarity (42.8%), self-confidence (42.5%), decrease of laborpain(39.9%). 3. The extent of delivery support a pregnant woman perceives reveals that physical support($x^2$=22.4452, P=.000) and information support($x^2$=7.5187, P=.0233) Show a significant difference among the mothers group, the mothers-in-law group, the husbands group, but to significant difference was found in emotional support among them. 4. The extent of delivery experience a pregnant woman perceives represents a significant difference in order of the mothers group, the mothers in-law group, and the husbands group($x^2$=13.4255, P=.0012). 5. A positive correlation was manifested between the extent of support and delivery experience a pregnant woman perceives(r=.8643, P=.000). This information can be utilized as data to further the understanding delivery experience according to supporter. In Consequence, it is recommended that the range of family support limited to husband should be expended including mother and mother-in-law.

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A study of 'the spleen(脾) is the basis of the acquired constitution(後天)' (비자후천지본(脾者後天之本)에 관한 고찰(考察) -오행이론을 중심으로-)

  • Jeong, Hyeon-Seok;Park, Chan-Guk
    • Journal of Korean Medical classics
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    • v.12 no.1
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    • pp.197-224
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    • 1999
  • The conception of 'earth(土)' belonging to the five evolutive phases(五行) is cognized that it is not partial to any side differing from other four phases and it can control other four phases so, it is the first gate to enter the process of changes. In the five organs(五臟), the spleen come under the earth phases and it have been very importantly considered for past to now in oriental medical history, for example by Li Dongyuan(李東垣). In this study, the results are summarized as the followings. 1. The term of the acquired constitution(後天) made by So-ong(邵雍), a scholar in the north so-dynasty, is used in the study of the book of changes(易經). And he said "The inborn constitution(先天) is the law of the nature itself and, the acquired constitution(後天) is the law of making the changes with the nature." In the myung-dynasty Li jungjae(李仲梓) made extract from this remarks 10 define that the spleen is the basis of the acquired constitution. So it considered that the the idea of changes(易) had an effect on the oriental medicine. 2. The one element of five phases, earth is the center of the changes and it composes the power of life with the sangsu(生數)-1, 2, 3, 4, and the sungsu(成數)-6, 7, 8, 9. In this process, the earth is the basis of the changes of the five phases. At the same time the spleen carry out the important physiological role in the humanbody controlling the other four organs. 3. In the change of the universe, the repetitionary movement of Yin(陰) and yang(陽) is the action of earth and it means illimitable division. In the course of this division all things change to new phases for example, the food changes 10 the ki(氣) through the action of spleen and stomach. So the organ of spleen and stomach is the space that the action of change occur. 4. Consequently the conception of bi(脾) is close to the pancreas that the spleen. And the duodenum is close to the conception of stomach because the space is the site of mito(未土). 5. The action of yin and yang in the ancient taegukdo(太極圖) is close 10 the connection of N-pole and S-pole. In the humanbody the two power is compared to the action of spleen and kidney, that means expansion and contraction. Also it means the inborn constitution and the acquired constitution so, it applyed to the all things in the universe.

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