• 제목/요약/키워드: Small Sample

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Y/MH의 혼합비가 YMnO$_3$ 세라믹의 소결 및 전기적 특성에 미치는 영향 (The effect of Y/Mn ratio on sintering and electrical properties of YMnO$_3$ ceramics)

  • 김재윤;김부근;김강언;정수태;조상희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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    • pp.657-660
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    • 1999
  • In this paper, we have investigated YMnO$_3$ bulk ceramics, which was made by Mixed oxide method, with Y/Mn ratios of 0.80/1.20, 0.90/1.10, 0.95/1.05, 1.00/1.00, 1.05/0.95 and 1.10/0.90. The samples crystall structure with Y/Mn ratios of 0.95/1.05 was hexagonal structure. The physical properties of YMnO$_3$ ceramics were divided into two groups, the sample with Y/Mn ratios of 0.80/1.20, 0.90/1.10 and 0.95/1.05 is classified to Mn rich sample, and with Y/Mn ratios of 1.00/1.00, 1.05/0.95 and 1.10/0.90 is classified to Y rich sample. The sintering and dielectric properties of this sample were summarized as following sintering density of Mn rich sample was increased. Dissipation factor of Mn rich sample was small The dielectric constant, dissipation factor of sample with Y/Mn ratio (0.90/1.10) were 37, 0.017 respectively at measured 1MHz

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중소기업실태조사를 위한 표본설계 (A sample design for the survey on actual state of SMEs)

  • 김달호;황진섭;곽상규
    • Journal of the Korean Data and Information Science Society
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    • 제21권6호
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    • pp.1021-1029
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    • 2010
  • 중소기업의 조사부담 완화를 위하여 2009년부터 기존의 "중소기업실태조사", "중소기업인력실태 조사" 및 "중소기업사업전환실태조사"를 통합하여 하나의 조사로 수행하게 되었다. 통합 중소기업실태조사를 위한 새로운 표본설계에서 중소제조업과 지식기반서비스업 부문이 너무 상이하므로 별개의 모집단을 구성하였으며, 전체 표본수는 10,000개로 하였다. 변동계수를 사용한 배분공식으로 1차 층인 종사자규모 산업분류별로 표본을 배분하고 루트비례배분을 사용하여 2차 층인 지역별로 표본의 크기를 결정하였다. 새로운 표본설계에서는 가중치를 계산하였고 이를 이용한 추정량과 추정오차 공식을 유도하여 기존의 단순집계를 벗어나 종사자 규모별, 업종별 그리고 지역별 추정과 추정의 정도에 대한 평가를 가능하게 하였다.

순환표본의 결합을 위한 가중치 산출에 대한 연구 (A Study on the Construction of Weights for Combined Rolling Samples)

  • 송종호;박진우;변종석;박민규
    • 한국조사연구학회지:조사연구
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    • 제11권1호
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    • pp.19-41
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    • 2010
  • 순환표본조사를 시행할 경우 매 순환주기별로 적절한 통계적 신뢰도를 가진 전체 모집단 특성이 추정될 수 있는 반면에, 작은 표본크기로 인하여 통계적 신뢰도가 높은 소지역 추정량의 산출은 어렵다. 따라서 소지역 추정량은 일반적으로 일정 주기 후 혹은 전체조사가 마무리된 후 독립적인 순환표본들을 결합하여 얻어진 최종표본을 통해 산출된다. 본 연구에서 는 순환표본을 결합하여 추정량을 만들 때 필요한 가중치 산출의 문제를 고려하였다. 기존의 연구들이 각 조사에 따른 경험을 바탕으로 조사별로 가능한 순환표본 결합 가중치를 정의하였으나, 본 연구에서는 모든 가능한 관심변수에 적용 가능하도록 표본설계변수에만 의존하는 모형을 설정하고 주어진 모형하에서의 최량선형불편예측치(Best Linear Unbiased Predictor: BLUP)를 고려하였다. 모의실험을 통하여 각 모형 하에서 정의되는 여러 BLUP을 비교하여 모형변화에 강건한 추정량을 제안하고 그 결과를 제4기 국민건강영양조사에 적용하였다.

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외국인 기관투자자와 기업지배구조가 차입비용에 미치는 영향 (The impacts of foreign institutional investors and governance mechanism on the cost of debt)

  • 김충환
    • 한국산학기술학회논문지
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    • 제14권1호
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    • pp.143-147
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    • 2013
  • 본 연구는 기업지배구조가 차입비용에 미치는 영향을 외국인 기관투자자의 역할에 초점을 맞추면서 분석하였다. 서로 다른 지배구조에 따른 차입비용에 영향을 보기 위해, 최대주주 지분율 기준으로 소유 집중도가 작은 기업표본, 중간 기업표본, 큰 기업표본으로 분류하여 회귀분석을 실시하였다. 분석결과, 소유 집중도가 중간이나 작은 기업표본에서는 외국인 투자자가 기업 차입비용에 영향을 미치는 것이 확인되지 않았으나, 소유 집중도가 큰 기업표본에서는 외국인 투자자가 기업의 차입비용을 크게 감소시키고 있는 것으로 나타났다. 본 연구의 학술적 시사점으로는, 지배대주주의 지분율이 높아질수록 이해일치가설에 의해 지배대주주는 자신의 사적 이익을 추구하게 되어 대리인 비용이 증가하고 경제적 가치가 하락하여 신용위험과 차입비용 증가로 이어질 수 있다는 것을 보여 준다. 실무적 시사점으로는, 외국인 투자자는 소유 집중도가 큰 기업에서 지배 대주주를 잘 견제 감시하고 경영의 외부감시 주체로서 경영 의사결정 효율화에 중요한 역할을 담당할 수 있다는 것을 보여준다.

연속주조한 구상흑연주철의 미세조직과 기계적 성질 (Microstructure and Mechanical Properties of Continuous Cast Ductile Iron)

  • 최경환;조규섭;이경환;김기영
    • 한국주조공학회지
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    • 제24권1호
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    • pp.52-59
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    • 2004
  • Microstructure and mechanical properties of ductile cast iron were investigated in terms of diameter change of samples that gives rise to modify the microstructure due to different cooling rate in the continuous casting process. The chemical composition used in this study was GCD 400 grade. From the microstructural observation, we have found a large number of graphite with small size in diameter which is comparable to the microstructure of the sample produced by conventional sand casting. The major reason of this would he due to high cooling rate. In the sample with 26 mm in diameter, the microstructure was composed of pearlite, iron carbide, and graphite. In the samples with 60 and 100 mm in diameter, however, we have observed a dissimilar microstructure that consisting of ferrite and graphite. Concerning the mechanical property, the sample with 26 mm in diameter showed higher hardness and strength compared to those samples with 60 and 100 mm in diameter. The result obtained for ductility appeared a reversal. Much more works such as inoculation, process design and chemical composition would be required in order to have a sound product even in a small diameter of samples.

Detection of Deep Subsurface Cracks in Thick Stainless Steel Plate

  • Kishore, M.B.;Park, D.G.;Jeong, J.R.;Kim, J.Y.;Jacobs, L.J.;Lee, D.H.
    • Journal of Magnetics
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    • 제20권3호
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    • pp.312-316
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    • 2015
  • Unlike conventional Eddy Current Test (ECT), Pulsed Eddy Current (PEC) uses a multiple-frequency current pulse through the excitation coil. In the present study, the detection of subsurface cracks using a specially designed probe that allows the detection of a deeper crack with a relatively small current density has been attempted using the PEC technique. The tested sample is a piece of 304 stainless steel (SS304) with a thickness of 30mm. Small electrical discharge machining (EDM) notches were put in the test sample at different depths from the surface to simulate the subsurface cracks in a pipe. The designed PEC probe consists of an excitation coil and a Hall sensor and can detect a subsurface crack as narrow and shallow as 0.2 mm wide and 2 mm deep. The maximum distance between the probe and the defect is 28 mm. The peak amplitude of the detected pulse is used to evaluate the cracks under the sample surface. In time domain analysis, the greater the crack depth the greater the peak amplitude of the detected pulse. The experimental results indicated that the proposed system has the potential to detect the subsurface cracks in stainless steel plates.

Definition of Success According to Women Entrepreneur in Malang, Indonesia

  • PRAJAWATI, Maretha Ika;WAHJOEDI, Wahjoedi;WAHYONO, Hari;SUNARYANTO, Sunaryanto
    • The Journal of Asian Finance, Economics and Business
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    • 제7권9호
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    • pp.747-753
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    • 2020
  • This study aims to interpret the meaning of a successful entrepreneur from the perspective of women entrepreneurs in Malang, Indonesia. This research offers a phenomenological approach using purposive sampling. Data was collected by in-depth interviews using structured questionnaire with registered women entrepreneurs in Malang obtained from MSMEs (micro small and medium-sized enterprises) entrepreneurs. The 'continually developing' is one of the meanings of a successful entrepreneur. This study also found that success is when what women do can be useful to others. Besides, the meaning of success has two criteria, i.e., when they can meet their needs (individual satisfaction) and social performance as a goal to be achieved by entrepreneurs. The motivation of women entrepreneurs to establish their venture was not only financial returns, but also personal satisfaction, which was also the indicator of entrepreneurial success for women. This study has several limitations. First, our sample size is too small and consists of entrepreneurs that have an average age above 40 years. Hopefully, further research will be able to generalize our findings to a broader sample in various industries outside the city of Malang. As our research shows, the criteria and meaning of success may be different for a larger sample of entrepreneurs.

공시된 자료를 이용한 한의원 환산지수 연구 (A Conversion factor of Oriental Medicine based on the publicly available information)

  • 오동일
    • 한국산학기술학회논문지
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    • 제9권2호
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    • pp.535-543
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    • 2008
  • 본 연구에서는 그 동안 많은 조사비용에도 불구하고 원가분석연구의 단점으로 지적되어왔던 적은 표본수와 신뢰성 문제를 해결하고 보다 적은 비용으로 한의원 환산지수를 산출할 수 있는 방법론을 개발하였다. 널리 공시되어 있고 쉽게 구할 수 있는 대규모 자료에 기반을 둠으로써 분석의 공정성과 검증가능성을 확보할 수 있었다. 그러나 공시된 자료의 종류에 따라 환산지수 차이가 발생하므로 공시된 자료를 이용한 분석과 표본 추출에 의한 원가분석을 병행해서 사용할 필요성이 있다. 보다 근본적으로는 합리적인 수가 산출을 위해서는 한의원과 관련된 원가정보를 포함하는 보건 의료 통계시스템 구축이 매우 절실하다.

Effect of Different Aging Times on Sn-Ag-Cu Solder Alloy

  • Ervina Efzan, M.N.;Siti Norfarhani, I.
    • Transactions on Electrical and Electronic Materials
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    • 제16권3호
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    • pp.112-116
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    • 2015
  • This work studied the thickness and contact angle of solder joints between SAC 305 lead-free solder alloy and a Copper (Cu) substrate. Intermetallic compound (IMC) thickness and contact angle of 3Sn-Ag-0.5Cu (SAC 305) leadfree solder were measured using varying aging times, at a fixed temperature at 30℃. The thickness of IMC and contact angle depend on the aging time. IMC thickness increases as the aging increases. The contact angle gradually decreased from 39.49° to 27.59° as aging time increased from zero to 24 hours for big solder sample. Meanwhile, for small solder sample, the contact angle increased from 32.00° to 40.53° from zero to 24 hours. The IMC thickness sharply increased from 0.007 mm to 0.011 mm from zero to 24 hours aging time for big solder. In spite of that, for small solder the IMC thickness gradually increased from 0.009 mm to 0.017 mm. XRD analysis was used to confirm the intermetallic formation inside the sample. Cu6Sn5, Cu3Sn, Ni3Sn and Ni3Sn2 IMC layers were formed between the solder and the copper substrate. As the aging time increased, the strength of the solder joint mproved due to reduced contact angle.

Determinants of Tax Aggressiveness: Empirical Evidence from Malaysia

  • JAFFAR, Rosmaria;DERASHID, Chek;TAHA, Roshaiza
    • The Journal of Asian Finance, Economics and Business
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    • 제8권5호
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    • pp.179-188
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    • 2021
  • The purpose of this study is to examine the level of aggressive tax planning (ATP) among companies listed in the Access, Certainty, Efficiency (ACE) Market of Bursa Malaysia. On top of that, this study also investigates the relationship between company characteristics, ethnicity, and ATP. This study uses a balanced pooled sample of 105 firm years-observations for the period from 2014 to 2018. These samples were selected to provide new insight into this market and to explore the attitude of small firms toward ATP in Malaysia. The data was retrieved from DataStream and the downloaded annual reports. The finding shows that profitability and financial distress have a significant relationship with ATP. Other variables including size, capital intensity, inventory intensity, leverage, and ethnicity, were not determinants of ATP. The result in this study may assist the reader in understanding the nature of companies in the ACE market, particularly on its behavior toward tax planning. A strict requirement is needed to be adopted in the sample selection process, thus limiting the sample size. Further, since the previous study focused on large companies, the discussion of this paper will provide new insight into the nature of tax planning within the small- and medium-sized companies in Malaysia.