• 제목/요약/키워드: attrition rate

검색결과 52건 처리시간 0.031초

황토를 지지체로 사용한 중온건식 아연계 탈황제의 반응특성 연구 (A Study on the Reactivity of Zinc-based Sorbents Using Yellow Earth as Support at Middle Temperatures)

  • 박노국;정용화;이종대;류시옥;이태진
    • 에너지공학
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    • 제12권4호
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    • pp.302-308
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    • 2003
  • 본 연구에서는 황토를 지지체로 사용한 고온연료가스 정제용 아연계 탈황제의 성능시험을 수행하였다. 산화아연과 황토를 75:25의 비율로 혼합하여 탈황제를 제조하였고 황화/재생 반응속도, 황수용능력, 내마모성을 조사하였다. 탈황 및 재생반응실험은 중온(황화/재생 : 48$0^{\circ}C$/58$0^{\circ}C$)에서 수행되었다. 황토를 지지체로 사용한 아연계 탈황제는 장기사이클실험중에 나타나는 급속한 비활성화가 억제되었으며 반응속도, 황수용능력, 내구성 그리고 내마모성이 개선되었다. 황수용능력은 약 19gS/100g sorbent정도로 10 cycle 까지 유지되었으며, 내마모도는 AI=19.1%정도였다. 아연계 탈황제의 성능개선은 황토에 함유된 금속산 화물(Fe$_2$O$_3$, $Na_2$O, MnO$_2$)의 영향으로 판단된다. 이들 결과로부터 황토를 지지체로 사용하여 중온건식 아연계 탈황제의 특성을 개선할 수 있음을 확인하였다.

Barriers to Participation in a Randomized Controlled Trial of Qigong Exercises Amongst Cancer Survivors: Lessons Learnt

  • Loh, Siew Yim;Lee, Shing Yee;Quek, Kia Fatt;Murray, Liam
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권12호
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    • pp.6337-6342
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    • 2012
  • Background: Clinical trials on cancer subjects have one of the highest dropout rates. Barriers to recruitment range from patient-related, through institutional-related to staff-related factors. This paper highlights the low response rate and the recruitment barriers faced in our Qigong exercises trial. Materials and Method: The Qigong trial is a three-arm trial with a priori power size of 114 patients for 80% power. The University Malaya Medical Centre database showed a total of 1,933 patients from 2006-2010 and 751 patients met our inclusion criteria. These patients were approached via telephone interview. 131 out of 197 patients attended the trial and the final response rate was 48% (n=95/197). Results: Multiple barriers were identified, and were regrouped as patient-related, clinician-related and/or institutional related. A major consistent barrier was logistic difficulty related to transportation and car parking at the Medical Centre. Conclusions: All clinical trials must pay considerable attention to the recruitment process and it should even be piloted to identify potential barriers and facilitators to reduce attrition rate in trials.

불꽃소멸에 의한 연삭특성에 관한 연구 (A study on the characteristic of grinding by spark-out)

  • 이연종;김정두
    • 오토저널
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    • 제15권3호
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    • pp.120-125
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    • 1993
  • The surface roughness of workpiece is reduced during spark-out. The reduction of roughness is a benefit of spark-out, but spark-out lowers productivity. The characteristics of spark-out are different to those of plunge grinding to which feed is applied. This difference is due to overlapping cutting during spark-out. Effect of spark-out is in proportion to volume of grain wear. This phenomenon is due to different overlapping area. Dressing interval can be enlarged by spark-out, when volume of grain wear is large. In this study, the characteristic of spark-out was studied by spark-out obserbation in various grinding conditions. For this purpose thrust force, spark-out time and surface roughness of workpiece were experimentally investigated in various grinding conditions.

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Firing State와 Observing State를 갖는 Lanchester형 전투모형에 관한 연구 (A Study on the Development of a Lanchester-Type Model Incorporating Firing & Observing States in the Direct Fire Engagement)

  • 함일환;최상영;송문호
    • 한국국방경영분석학회지
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    • 제17권2호
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    • pp.44-53
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    • 1991
  • This paper is aimed to develop a Lanchester type combat model for the direct-fire engagement. This model incorporates number of combatants, inter-firing time, detection time by movement, detection probability by the signature of fire, where the inter-firing time and the detection time are assumed to follow a negative exponential distribution. The approach to modeling is as follows : in the process of an engagement, a combatant takes one of the states('observing' state or 'firing' state), a combatant is initially in the observing state, if the combatant detects a target, he changes his state from 'observing' to 'firing' and will cause attrition to the opposing forces. Thus this transition mechanism is embodied into the differential equation form with each transition rate. A limited examination of the validity has been conducted by comparison with the Monte-Carlo simulation model 'BAGSIM', and with a traditional Deterministic Lanchester model.

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EFFECTIVE USAGE OF FIXED AMOUNT OF SCATTERABLE MINES ON THE INFANTRY BATTLEFIELD

  • Lee, Jae-Yeong
    • 한국국방경영분석학회지
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    • 제16권1호
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    • pp.94-112
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    • 1990
  • The basic mathematical tools are developed to determine the optimum emplacement of limited numbers of scatterable mines on the infantry battlefield. A deterministic model is developed for heterogeneous infantry battalion level battle using APL version 7.0. The Helmbold-type combat equation is applied to claculate comparative casulties, and range dependency is also considered to establish the correlation between attrition rate coefficients and the distance of opposing forces, Based on this deterministic model the effective range for employment of scatterable mines is determined. Because mines are primarily effective when employed in conjunction with direct fire weapons, it is inferred that minefield are best employed when used within the maximum effective range of infantry weapons systems such as the M16Al rifle. The model developed verifies this fact.

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전투종료규칙의 포괄적 적용방법 (An Inclusive Method for Application of Combat Termination Rules)

  • 백자성;하석태
    • 한국국방경영분석학회지
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    • 제26권1호
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    • pp.125-144
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    • 2000
  • Occasionally, there are combat situations which one or both forces can´t terminate the combat using selected combat termination rule according to given relationship between ratio of attrition rate coefficient and threshold values. In this study, we classify the situations that one or both forces can´t terminate the combat with selected combat termination rule into four conditions. Condition${\circled1}$ is the situation which both Blue and Red can terminate the combat using all selected combat termination rules. condition${\circled2}$ and condition${\circled3}$ are those which neither Blue or Red can terminate the combat using selected proportional decision rule, and condition${\circled4}$ is that which both Blue and Red can´t terminate the combat using selected proportional decision rule. We analyze the effect of combat termination rules on parity number, final combat power, and combat durations for each conditions. Also, we propose the method to apply the analyzed effect of combat termination rules to combat analysis.

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생전분의 효소당화에서 유리구 마찰효과 (Attrition Effect of Beads on Enzymatic Saccharification of Raw Starch)

  • 최성현;김찬조;이석건
    • Applied Biological Chemistry
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    • 제32권4호
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    • pp.374-377
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    • 1989
  • 생전분 분해효소에 의한 전분의 당화에서 유리구를 첨가시켜 회전진탕시키므로 당화시간의 단축과 당화율의 증대에 효과가 있었다. 옥수수전분과 유리구의 중량비를 1 : 5로 하여 Streptomyces sp. 4M-2의 ${\alpha}-amylase$를 첨가하고 300rpm으로 교반시켰을 때 30시간 후에 88%, 감자전분에서 69%의 당화율을 나타냈다. 옥수수전분에서 amyloglucosidase를 병용하였을 때는 6시간 후에 88%의 당화율을 보였다.

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란체스터 모형에 대한 통계적 고찰과 해석 (Statistical review and explanation for Lanchester model)

  • 유병주
    • 응용통계연구
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    • 제33권3호
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    • pp.335-345
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    • 2020
  • 본 논문에서는 과거 2차 세계대전 자료 중 Ardennes 전역에서 있었던 실제 전투 자료를 란체스터 모형에 적합 시키기 위하여 로그변환된 선형회귀모형을 추정하는 문제를 다루었다. 먼저 동일한 자료에 대하여 기존 연구 결과를 고찰하여 모수에 대한 최적해(Global Solution) 결정 문제와 다중공선성 문제들을 확인하였다. 최소제곱 추정법에 의한 모수 추정은 특정 제약조건이나 제한된 후보군을 고려할 경우 최적해를 찾지 못하고 지역해(Local Solution)를 찾을 수 있음으로 주의가 필요하고, 모형에 포함된 변수들은 통계적으로 충분히 유의성을 검토하여 포함해야지 그렇지 않았을 때 모수 추정값들이 왜곡될 수 있다. 모형에 과도하게 많은 설명 변수를 포함하는 경우 변수 간의 상관관계로 인하여 추정값이 왜곡되고 변수의 추가나 제거 시 불안정한 현상들이 발생한다. 이런 다중공선성 문제를 탐색하는 방법은 설명 변수 간의 선형적 연관 관계를 측정할 수 있는 분산확대인자(VIF)로 알려진 통계량에 의해 확인이 가능하며 이를 조치하기 위해서는 상호 연관된 설명 변수들을 제거하여 모형을 단순화해야 한다. 그래서 이러한 문제가 발생하지 않도록 모형을 단순화하고 이해와 설명이 용이한 전투력 손실률 모형을 제안하였고 Ardennes 자료에 대하여 적합한 결과 모수 추정이 안정적이고 자료에 대한 설명과 해석이 용이하다는 점을 입증하였다. 특히, 모수 추정간 선형회귀 모형의 기본적인 가정사항인 독립성, 정규성, 등분산성을 검증하여 자기상관(Autocorrelation) 문제로 독립성이 훼손되어 과대 과소 추정될 우려가 있는 사항을 Cochrane-Orcutt 방법에 의해 변환하여 독립성과 정규성을 보장하였다.

Quitline Activity in Rajasthan, India

  • Gupta, Rakesh;Verma, Vinit;Mathur, Pankaj
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권sup2호
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    • pp.19-24
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    • 2016
  • Quitline activity in Rajasthan, India is a voluntary activity of Rajasthan Cancer Foundation (RCF) since April 2013. To kick-off, it took the benefit of the State Government- PIRAMAL SWASTHYA (PS)1 collaborative 104 Health Information Helpline that existed already in public-private partnership. It is a reactive quitline that helps callers through the counselors and nursing staff trained specifically through the weekly sessions held by the first author, the RCF resource on quitline. Besides structuring of the scripts for primary intervention and follow-ups after 1 week, 1 month, 6 months and a year, he also monitors calls, advices and coordinates with the supervisors to manage and analyze the data base, and reports to the PS lead at the Jaipur Center on overall performance and to plan strategic communication with the State Government on its outcomes. The quitline has limitations of its informal existence through a voluntary effort of RCF, no specific resource allocation, suboptimal data management, minimal awareness in the masses due to poor IEC (Information, Education and Communication; except its efforts made by RCF in last 1 year through the government-run State TV and City Radio) and staff shortage and its attrition due to lack of plan for career advancement. Despite these challenges in the year 2013, the quit line has registered a quit rate (for complete abstinence) of 19.93% amongst 1525 callers. The quit rate were 58.01% (304/ 524) among the responders at the 3rd follow-up at 18 months (in September 2014)2. In view of an increase in quit rate by 5- 9 times over the prevailing quit rate in the former ever daily users [both smokers and the users of smokeless tobacco (SLT)], efforts are being made by RCF in concurrence with PS to have this cost-effective model established formally with optimal resource allocation in collaboration with willing agencies (the State and Central Governments and the International Quitline Agencies) and its replication in 4 more states where PS is collaborating with the respective state governments similarly (Assam, Chhattisgarh, Jharkhand and Karnataka).

Using Analytic Network Process to Construct Evaluation Indicators of Knowledge Sharing Effectiveness in Taiwan's High-tech Industries

  • Liu, Pang-Lo;Tsai, Chih-Hung
    • International Journal of Quality Innovation
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    • 제9권2호
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    • pp.99-117
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    • 2008
  • High-tech industry has been the principal economic source for Taiwan in recent years. The characteristics of high-tech industries in Taiwan are changeable product markets, short product life cycles and high company attrition rate. In the globalization trend, the high-tech industry has gradually increased corporate competitiveness and reached the goal of sustainable operations through knowledge management, knowledge sharing and new product research and development. Firms have aggressively strengthened and integrated their internal and external resources and enhanced knowledge sharing to increase industry operational performance. Effectively strengthening the knowledge management operation and performance evaluation of knowledge sharing in Taiwan's high-tech industry has become a critical issue. In the selection of knowledge sharing Key Performance Indicators (KPI), this research divided the knowledge sharing indicators into representative strategic indicators such as organizational knowledge learning, organizational knowledge resources, organizational information capacity and organizational knowledge performance through screening using Factor Analysis. The characteristics of the constructs were interdependent. This research calculated and adjusted the correlation among the key performance knowledge sharing indicators using ANP and determined the relative weight of knowledge sharing.