• 정보처리학회논문지D
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• 제13D권5호
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• pp.709-716
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• 2006

소프트웨어 복잡도가 증가할수록 소프트웨어 성공률은 기하급수적으로 감소하며, 반대로 실패율은 증가한다. 소프트웨어 규모 증가에 따른 실패율은 성장곡선으로 표현할 수 있다. 이 현상에 따라, 본 논문은 Gompertz 성장곡선으로 개발 성공률과 완료율을 추정하였다. 먼저, 수치적으로 제시된 $10^n$의 소프트웨어 규모를 로그값으로 변환시켜 데이터 간격을 일정하게 하였다 로그값의 소프트웨어 규모 변화에 따른 개발 성공률과 완료율의 함수관계를 유도하고자 하였다. 그러나 이 관계를 적절히 표현하는 함수를 찾지 못하였다. 따라서 본 논문에서는 개발 성공률의 역 개념인 실패율과 완료율의 역 개념인 취소율을 도입하였다. 로그값의 소프트웨어 규모 변화에 따른 개발 실패율과 취소율 관계는 성장곡선 형태를 나타내었다. 결론적으로, 개발 취소율과 실패율을 적절히 표현하는 함수로 Gompertz 성장곡선을 적용한 결과 실측 데이터를 적절히 표현할 수 있었다. 본 모델을 적용하면 특정 규모의 소프트웨어에 대한 개발 성공률과 완료율을 보다 정확히 얻을 수 있을 것이다.

• 한국세라믹학회지
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• 제32권11호
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• pp.1227-1232
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• 1995

Effect of heating rate on the microstructure of the silicon nitride ceramics has been investigated. The specimens with composition of 92Si3N4-6Y2O3-2Al2O3 (in wt%) were sintered at 176$0^{\circ}C$ under 127 kPa for 3h in N2 atmosphere at various heating rates from 1 to 10$0^{\circ}C$/min. The grain size of larger than 2${\mu}{\textrm}{m}$ and less than 1${\mu}{\textrm}{m}$ were measured and compared for the specimens. Regardless of heating rate, grain size of all the specimens showed bimodal distributions and the fracture toughness remained in the range of 5.53~5.72 MPa.m1/2. However, the aspect ratio of the grains of diameter above 2${\mu}{\textrm}{m}$ increased with the heating rate while their grain size and volume fraction decreased.

• 산업경영시스템학회지
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• 제38권2호
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• pp.72-81
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• 2015

This paper studied the differences of the inventories asset turnover change ratio and several characteristics variable between large and small manufacturing firm group. Large and small firm group were determined based on number of labors and asset size. Several characteristics variable of firms such as assets size, sales growth rate, return on assets, leverage ratio, credit rating and age of firm were used to find out the differences of firm group. As a result, the inventory asset turnover change ratio of large firm was 5.16% and that of the middle and small firm was 9.3%. For the large firm, sales growth rate, ROA and credit rating affect inventory assets turnover change ratio. For the middle and small sized firm, Assets size, sales growth rate and credit rating affect inventory assets turnover change ratio. Using this result, we can say that manufacturing company need to consider their firm size and their characteristics to make their own operation strategy of inventory.

• 대한의용생체공학회:의공학회지
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• 제28권1호
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• pp.1-7
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• 2007

To determine the effect of posture change on autonomic activity and to investigate valid parameters to reflex the autonomic activity from time-series pupil size data, a posture-related experiment was performed with 15 subjects, which involved measuring their electrocardiograms and pupil sizes. The experimental procedure consisted of three-sequence postures-supine, sitting and upright-for 5 minutes each, with rest sessions between postures. The subjects were notified of the entire experimental procedure. The parameters of the subjects' heart rate variability showed significant differences between the postures (heart rate: 63-70-80 beat, normalized low frequency power: 28-50-75, normalized high frequency power: 72-49-25 and ratio: 0.5-1.2-4.4 in supine-sitting-upright position respectively) as did the parameters of their mean pupil sizes (41300-53900-53700 pixels respectively) and the major frequencies (the third trend: 0.23-0.2-0.18 Hz respectively) of their pupil size variability according to changes in their autonomic activities induced by posture change. The experiment thus proved that posture change affects autonomic activity and that such activity can be estimated by the parameters of pupil size as similar as heart rate variability.

• 산업기술연구
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• 제21권B호
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• pp.149-153
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• 2001

A study on the particle growth in $TEOS/O_2$ plasma was performed, and particle size and its distribution was measured by the electrical aerosol analyzer (EAA), light scattering particle size analyzer and the particle size was also determined by SEM. The effects of process variables such as total gas flow rate, reactor pressure, supplied power and initial reactant concentration on the particle growth were investigated. From the EAA results, the particle size distribution is divided into three groups of the cluster size and the small and large size particles. The particle size distribution measured by the light scattering particle size analyzer becomes bimodal, because the cluster size particles smaller than 20 nm in diameter cannot be detected by the light scattering particle size analyzer. The size of particles measured by the light scattering particle size analyzer is in good agreements with those by the SEM. Also we could understand that the particle formation is very sensitive to the changes of reactor pressure and reactant concentration. As the total gas flow rate increases, the particle size decreases because of the shorter residence time. As the reactor pressure, or the reactant concentration increases, the particle concentration increases and the particles grow more quickly by the faster coagulation between particles.

• 디지털콘텐츠학회 논문지
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• 제8권1호
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• pp.9-15
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• 2007

스무딩은 가변 비트율로 저장된 비디오 데이터를 고정 비트율로 변환하는 전송 계획이다. 이러한 스무딩 알고리즘들에는 CBA, MCBA, MVBA, PCRTT, e-PCRTT 알고리즘 등이 있다. 이중에서 PCRTT 알고리즘을 개선한 e-PCRTT 알고리즘은 전송률 변화 횟수가 주어지고 런의 크기가 일정하다. 이는 버퍼 크기가 크고 런의 크기가 작은 경우에 불필요한 전송률의 변화를 필요로 한다. 본 논문에서는 e-PCRTT 알고리즘의 단점을 해결하기 위해 동일한 전송률로 보다 많은 구간을 전송할 수 있게 e-PCRTT 알고리즘을 개선한 알고리즘을 제안하고 성능을 평가한다. 제안 알고리즘의 성능은 e-PCRTT 알고리즘과 전송률 변화 횟수, 첨두 전송률, 전송률 변화량 등의 평가 요소들로 비교하여 우수함을 보였다.

• Journal of Gastric Cancer
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• 제12권3호
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• pp.164-172
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• 2012

Purpose: The purpose of this study is to investigate the prognostic significance of tumor size for 5-year survival rate in patients with gastric cancer. Materials and Methods: A total of 1,697 patients with gastric cancer, who underwent potentially curative gastrectomy, were evaluated. Patients were divided into 4 groups as follows, according to the median size of early and advanced gastric cancer, respectively: small early gastric cancer (tumor size ${\leq}3$ cm), large early gastric cancer (tumor size >3 cm), small advanced gastric cancer (tumor size ${\leq}$ 6 cm), and large advanced gastric cancer (tumor size >6 cm). The prognostic value of tumor size for 5-year survival rate was investigated. Results: In a univariate analysis, tumor size is a significant prognostic factor in advanced gastric cancer, but not in early gastric cancer. Multivariate analysis showed that tumor size is an independent prognostic factor for 5-year survival rate in advanced gastric cancer (P=0.003, hazard ratio=1.372, 95% confidence interval=1.115~1.690). When advanced gastric cancer is subdivided into 2 groups, according to serosa invasion: Group 1; serosa negative (T2 and T3, 7th AJCC), and Group 2; serosa positive (T4a and T4b, 7th AJCC), tumor size is an independent prognostic factor in Group 1 (P=0.011, hazard ratio=1.810, 95% confidence interval=1.149~2.852) and in Group 2 (P=0.033, hazard ratio=1.288, 95% confidence interval=1.020~1.627), respectively. Conclusions: Tumor size is an independent prognostic factor in advanced gastric cancer irrespective of the serosa invasion, but not in early gastric cancer.

• 한국군사과학기술학회지
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• 제20권6호
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• pp.844-852
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• 2017

Since guided weapon is high-cost and one-shot device which is non-reusable, it requires a lot of resources to prove required accuracy as a part of reliability demonstration. Once a test for proving accuracy rate of guided missile fails, it causes an additional cost and delay of schedule. This study introduces an equation for proper sample size and plan for guided-missile accuracy rate test in order to minimize the risk of test failure. Proper sample size for the test is derived by considering the reliability growth. Furthermore, each task for accuracy rate test is defined according to the development step. Therefore, this study can contribute to reduce sample size for accuracy rate test in order to meet the reliability requirement and assure transparency in the test process.

• Fisheries and Aquatic Sciences
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• 제8권2호
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• pp.90-96
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• 2005

The larvae of Palaemon gravieri were reared in the laboratory at three different temperature regimes ($15^{\circ}C,\;20^{\circ}C,\;and\;25^{\circ}C$) with the salinity ranges (28-32 psu) to understand how temperature and body size influence survival rate, and growth components (molt increment and intermolt period). The optimum temperature for the highest survival rate was $25^{\circ}C$. The intermolt periods consistently increased with an increase in size and instar number; however, the molt increments at successive instars generally decreased with an increase in size and instar number. The shortest intermolt period and the highest larval growth rate both occurred at $25^{\circ}C$. Thus, the optimum temperature for larval survival and growth rate was found to be $25^{\circ}C$ which was the temperature at which the larvae actually appear in nature.

• 한국기계기술학회지
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• 제13권4호
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• pp.9-14
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• 2011

The flow rate analysis for sanitary fixtures has been studied to determine the water supply piping system and size. The study has been carried out to analyze for a various water supply pressure and piping size theoretically. Also, the study has been carried out to analyze for a various water supply piping system experimentally. The water supply pressure is varied from 0.01MPa to 0.07MPa, and the piping size is varied from 6mm to 15mm. The water supply piping systems are one-to-one, all-loop-type, and bathroom-loop-type water supply piping system. The results indicate that the piping size is able to supply water fully in case of smaller than 15mm if the water supply pressure keep an necessary minimum pressure. And the gap of flow rate is very little for the various water supply piping systems.