• 산업경영시스템학회지
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• 제39권1호
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• pp.91-97
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• 2016

This study is concerned about the process capability index in single process. Previous process capability indices have been developed for the consistency with the nonconforming rate due to the process target value and skewness. These indices calculate the process capability by measuring one spot in an item. But the only one datum in an item reduces the representativeness of the item. In addition to the lack of representativeness, there are many cases that the uniformity of the item such as flatness of panel is absolutely important. In these cases, we have to measure several spots in an item. Also the nonconforming judgment to an item is mainly due to the range not due to the standard variation or the shift from the specifications. To imply the uniformity concept to the process capability index, we should consider only the variation in an item. It is the within subgroup variation. When the universe is composed of several subgroups, the sample standard deviation is the sum of the within subgroup variation and the between subgroup variation. So the range R which represents only the within subgroup variation is the much better measure than that of the sample standard deviation. In general, a subgroup contains a couple of individual items. But in our cases, a subgroup is an item and R is the difference between the maximum and the minimum among the measured data in an item. Even though our object is a single process index, causing by the subgroups, its analytic structure looks like a system process capability index. In this paper we propose a new process capability index considering the representativeness and uniformity.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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• pp.729-736
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• 1997

This paper gives the information of field concrete placed under raining condition. Experimental factors in this study are concrete strength, standard deviation and coefficient of variation. The results are as follows: 1. The strength of field concrete placed under raining condition is not largely dependent on the raining condition. 2. But, the quality of concrete is very critical.

• 한국지반환경공학회 논문집
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• 제13권11호
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• pp.43-50
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• 2012

본 연구에서는 국내외 적용 중인 압밀지수의 값을 조사하고 조사된 표준편차 범위를 분석하였으며, 편차에 따른 침하량을 계산하였다. 또한 지반에서 내재한 불확실성 변수인 압축지수가 연약지반 처리공법 하에서 미치는 영향을 분석하였다. 수치해석을 통해 프리로딩 공법, 배수촉진 공법, 치환 공법을 적용하여 성토단계별 침하거동을 분석하였고, 추가적으로 장기적인 침하에 안정적인 Piled Raft 공법을 추가로 분석하여 침하거동을 파악하였다. 그 결과, 최종침하량에 따른 평균분석 결과는 해석 값의 평균, 해석값의 최대 최소의 중간값, 평균 압축지수(Cc=0.35)를 사용할 경우에 발생된 침하량이 상이한 것으로 나타났다. 최종침하량에 따른 변동계수의 비교 분석 결과, 각 공법별로 시간에 따라 변동계수의 차이를 보였다. 그 중 Piled Raft 공법이 시간의 경과와 상관없이 일정한 변동계수 값을 보이며, 다른 공법보다 낮은 값으로 불확실성 지반정수의 압축지수에 영향이 가장 적은 것으로 확인되었다.

• International Journal of Industrial Entomology and Biomaterials
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• 제6권2호
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• pp.171-178
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• 2003

Four thermo-tolerant lines of silkworm, Bombyx mori, (L.) viz., A HT, B HT (Chinese type) and F HT, G HT (Japanese type) were evolved by utilizing the breeding resource material (identified from initial screening at a temperature of 31 ${\pm} 1^{\circ}C$ and relative humidity 85 ${\pm}$ 5%) through conventional breeding. These tolerant lines were crossed with productive breeds and forty four hybrids were evaluated on eight economic traits by the Multiple Trait Evaluation Index Method. Ten hybrids were short-listed based on the average evaluation index value larger than 50 for eight economic traits studied. The identified ten hybrids recorded higher index values (＞ 50) for most of the traits studied. Single hybrid G ${\times}$ CSR12 indicated average index value larger than 50 for six traits viz., pupation number (58), cocoon weight (67), shell weight (65), average filament length (74), raw silk % (69), reelability % (51) except for shell ratio % (41). The standard deviation of the cocoons in the above hybrid was 8.41 in the hybrid cocoon length and width measurement. However, two selected hybrids viz., A ${\times}$ CSR5 and G ${\times}$ CSR13 recorded average index value larger than 50 for all the traits viz., pupation number (57, 60), cocoon weight (50, 54), shell weight (56, 57), shell ratio percentage (59, 53), average filament length (55, 60), raw silk percentage (63, 67) and reelability percentage (53, 53). The standard deviation of the cocoons in the two selected hybrids viz., A ${\times}$ CSR5 and G ${\times}$ CSR13 was 8.41 and 8.06 respectively in the cocoon length and width measurement.

• 한국CDE학회논문집
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• 제18권5호
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• pp.359-366
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• 2013

In the lower arm design process, a tolerance optimization of the variance of design variables should be preceded before manufacturing process, since it is very cost-effective compared to a strict management of tolerance of products. In this study, a design of experiment (DOE) based on response surface model (RSM) was carried out to find optimized design variables of the lower arm, which can meet a given requirement of probability constraint for the process capability index (Cpk) of the weight and maximum stress. Then, the design space was explored by using the central composite design method, in which the 2nd order Taylor expansion was applied to predict a standard deviation of the responses. The optimal solutions satisfying the probability constraint of the Cpk were found by considering both of the mean value and the standard deviation of the design variables.

• 한국전자파학회논문지
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• 제15권6호
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• pp.599-607
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• 2004

이 논문은 PLL주파수 합성기의 루프 대역폭보다 높은 주파수에서 낮은 주파수까지 변화하는 신호에 대한 주파수 변조가 일정한 최대 주파수 편이를 갖도록 하는 단순하면서도 저가의 새로운 주파수 변조회로를 소개하였다. 이 주파수 변조회로는 PLL 안에서의 주파수에 따른 루프 필터의 궤환량을 보상하도록 설계되었고 최대주파수 편이값 조절과 루프와의 상호 간섭을 제거할 수 있도록 설계되었다. 또한 기존의 스펙트럼 분석기로 $\Delta$f(최대 주파수 편이)또는 $\beta$(변조 지수)를 측정하는 방법은 협대역 주파수 변조에서만 유용하여 광대역 주파수에서 측정할 수 있도록 새로운 측정방법을 제안하고 변조 신호 발생기를 이용하여 정확성을 확인하였다. 이런 한 방법으로 설계하여 제작한 회로를 측정하여 기대한 일정한 최대 주파수 편이를 가지는 것을 확인하였다.

• 대한치과교정학회지
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• 제23권1호
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• pp.17-35
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• 1993

We tried to evaluate frequencies and severities of malocclusion of various socioeconomic areas according to growth and development. To obtain objective validity, we used Handicapping Labiolingual Deviation (HLD) suggested by Draker, Treatment Priority Index (TPI) by Grainger, Handicapped Malocclusion Assessing Record (HMAR) by American Dental Association and American Association of Orthodontist. Seoul and Kwangju were selected as an urban group, Ahnyang as an middle socioeconomic group and Hwasun near the Kwangju area as an rural group. 140 (male 63, female 73) of 5th grade in 'E' elementary school students in Seoul, 202 (male 101, female 101) of 'S' elementary school students in Kwangju, 207(male 105, female 102) of 'H' elementary school students in Hwasun, and 100(male 49, female 51) of 'M' elementary school students of in Ahnyang of all the same grade were analyzed and we obtained the results as follows; 1. TPI, HLD, and HMAR showed high coincidence and reproducibility between different observer. (p<0.01) 2. In comparison of TPI, HLD, and HMAR according to clinical decision, there was statistically difference between each other. (p<0.01) 3. As the severity of malocclusion increases there was high correlation between TPI and HLD, and between HLD and HMAR (p<0.05) 4. With respect to differences between areas in TPI and HLD, there was statistically difference between Ahnyang and other areas. 5. In Seoul as an urban group there was a high incidence of periodic checkup and history of orthodontic treatment than other area. 6. Mode of feeding and posture during sleeping did not affect the severity of malocclusion. As a conclusion, TPI, HLD and HMAR are so reproducible and coincident that they can be used as a guide on evaluating the frequency and severity of malocclusion and determining the priority of orthodontic treatment to determine the need and supply of orthodontic treatment. Furthermore these indices can provide objectively valid data for establishing public health problem solution.

• 펄프종이기술
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• 제38권3호
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• pp.47-60
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• 2006

This study was carried out to investigate the sheet formation properties of Morus Hanjis, made of bast and whole stalk pulps by different pulping methods, such as alkali, alkali-peroxide and sulfomethylated pulping. Two species of Morus, M. alba and M. lhou, were used. Effect of morphological properties of pulp stocks on the sheet formation and its gray levels based on optical property were evaluated using an Image analyzer. In addition, the effect of fiber distribution index(FDI) which was calculated from tile data of Confocal laser scanning microscopy(CLSM) on the sheet formation and optical properties of Morus Hanji were also discussed. On the sheet formation, Hanji from whole stalk pulp was superior than that of bast pulp. The more the sheet formation improved, the more paper opacity decreased. In the aspect of Hanji's surface characteristics analyzed by an Image analyzer, the average gray level and its standard deviation of Hanji from the whole stalk pulp were rather lower than those of bast pulp because of better sheet formation of the former. However, high brightness Hanji showed high value of gray level. The sheet formation and paper opacity were increased with the decrease of standard deviation of gray level. From these results, gray level measurement could be used to predict the paper opacity as well as sheet formation. Sheet formation of whole stalk Hanji and its FDI measured by CLSM were higher than those of bast fibers. In conclusion, the sheet formation and opacity of Hanji could be evaluated by standard deviation value of Hanji's gray level using an Image analyzer and by fiber distribution index using CLSM.

• 한국전산구조공학회논문집
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• 제21권5호
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• pp.413-419
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• 2008

확정론적 최적설계에서는 설계변수의 변동이나 불확실성 등을 최적화 과정에서 고려하지 않는다. 신뢰성 최적설계는 설계변수의 임의성을 체계적인 확률 및 통계이론을 적용하여 생산품의 안정성을 보다 정밀하고 합리적으로 다룬다. 본 논문에서 설계변수를 확률변수로 취급하여 실제 제작시의 제작오차를 고려한 표준편차를 주었으며, 설계변수의 평균에 대한 표준편차를 기존의 고정된 값을 사용하지 앉고 평균과 표준편차의 관계가 오목함수로 나타나도록 하였다 즉, 설계변수의 평균이 달라짐에 따라 표준편차도 변동계수만큼 변하도록 하였다. 신뢰성해석은 불변 2차 모멘트 방법을 이용하고 신뢰성을 구하는 방법은 신뢰도 지수 접근방법의 개선된 일계 2차 모멘트 방법을 이용하여 신뢰성을 구하였다. 두 가지 예제를 통해 확정론적 최적설계, 신뢰성 최적설계와 표준편차의 변동을 고려한 신뢰성 최적설계의 값을 비교하였다.

• 재무관리연구
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• 제21권1호
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• pp.205-229
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• 2004

풋-콜 패리티에 괴리가 생길 경우 각종 차익거래 및 스프레드 전략이 가능하게 되고 이로 인해 현물, 선물 및 옵션시장 가격의 움직임이 발생하게 되므로 이 관계식의 성립여부는 실제로 시장가격에 영향을 미칠 수 있다. 본 연구에서는 10분 간격으로 측정된 현물, 선물, 콜 옵션, 그리고 풋 옵션 가격 및 가격의 변화가 풋-콜 패리티 조건으로부터의 괴리율과 어떤 관계를 가지고 있는지 GARCH(1,1)모형을 이용하여 분석하였다. 우선 풋-콜 패리티 조건에 괴리가 발생했을 때 다시 균형상태로 회귀하려는 경향을 발견할 수 있었다. 즉, 괴리율이 (+)의 값을 가질 때 현물가격과 풋 옵션의 가격은 하락하고, 콜 옵션의 가격은 상승함으로써 향후 괴리율의 크기가 줄어드는 모습을 보여주었다. 시장에 따라 다소 차이가 있지만 전반적으로 괴리율의 변화는 각 시장에서 가격의 향후 변동에 약 60분가량 영향을 주고 있었으며, 시차항 변수에 대한 회귀계수의 크기를 비교해볼 때 시간이 지날수록 괴리율이 각 시장가격에 미치는 영향도 점차 줄어들고 있었다. 그러나 KOSPI 200 주가지수 선물가격의 움직임에서는 풋-콜 패리티 괴리율과의 뚜렷한 연관성을 보이지 않았다. 교차상관분석에 따르면 주가지수선물의 가격이 새로운 정보에 가장 신속하게 반응함으로써 기타 시장에서의 가격을 일정기간 선도하고 있는 것으로 여겨진다.