• 한국병원경영학회지
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• 제12권1호
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• pp.51-74
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• 2007

This study applied Data Envelopment Analysis to a set of Korean Public Corporation Medical Centers and Japanese Municipal Hospitals to compare their relative human resource efficiencies. Based on the data provided on the inputs and outputs, the analysis showed Japanese municipal hospitals were relatively efficient than Korean hospitals. The result of analysing BCC model shows 5 hospitals in Japan and 7 in Korea with an efficiency rating of less than 1 as considered relatively inefficient. For the inefficient hospitals the manner in which inefficient hospitals may be made efficient were indicated by the managerial strategies based on dual variables. A subsequent analysis of Wilcoxon rank-sum test revealed that the medical revenue per medical expense, labor cost per value added revenue were statistically significant between efficient and inefficient Korean hospitals and medical revenue per medical expense, labor cost per value added revenue, bed occupancy rate, average length of stay, rate of personnel expenses per medical revenue were statistically significant between efficient and inefficient Japanese hospitals.

• 전자공학회논문지S
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• 제35S권4호
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• pp.85-95
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• 1998

In this paper, a new watermarking method for a copy protectionof images is proposed. The proposed method adaptively embeds a watermark in the frequency domain of images using human visual system model. For this purpose, the Just Noticeable Differences(JNDs) of each frequency coeffeicient value of a luminance plane is first found using Watson and Solomon's visual system model. An invisible maximum watermark value with is different in every position according to the characteristics of images is determined usig JND and Minkowski metric. A low frequency domain is divided into two sets based on a PN-sequence to protect thewatermark from the attack. The watermarks are added to one set of coefficients and detecting a watermark, the difference between the mean values of absolute coefficient values of both sets is calculated. The embedded watermark is tested using statistical hypothesis based on test static dertermined by the ean difference. To demonstrate the perfromance of the proposed method, the new watermarking method is applied to a high frequency image and low frequency images. Experimenatal results show the watermark is invisible and robust to JPEGlossy compression and noise.

• Elastomers and Composites
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• 제52권4호
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• pp.237-241
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• 2017

The tensile strength (TS) and elongation-at-break (EB) loss of a CR/CB rubber composite sample prepared for the automotive parts were measured after accelerated thermal ageing at temperatures of 100, 120, 140, and $150^{\circ}C$. The change in TS was observed to be linear from the master curve prepared using the time-temperature superposition-principle (TTSP). An Arrhenius type of shift factor, $a_T$ was used to predict the life time of the sample, and a plot of ln $a_T$ vs. 1/T was also shown to be linear. The activation energy ($E_a$) of the sample was calculated as 70.30 kJ/mole from the Arrhenius plot. The expected life time of the sample was predicted at the given operating conditions by applying Arrhenius analysis. Assuming the $E_a$ value was constant at lower operating condition, life time of the sample was calculated as 2.3 years when the life limit was set as time to reach the 20% decrease of the initial TS value at operating temperature of $40^{\circ}C$.

• Advances in concrete construction
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• 제6권1호
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• pp.15-28
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• 2018

In the present investigation, influence of various material parameters on the cavitation erosion resistance of concrete was investigated on the basis of laboratory experiments. As there is no well-established laboratory test method for evaluating the cavitation resistance of concrete, a test set up called 'cavitation jet' was specially established in the present study in order to simulate the cavitation phenomenon experienced in the hydraulic structures. Various mixtures of concrete were designed by varying the grade of concrete, type and quantity of pozzolana, type of aggregates and cement type to develop good cavitation resistant concrete constructed using marginal aggregates. Three types of aggregates having three different Los Angeles abrasion values (less than 30%, between 30% and 50% and more than 50%) were employed in this study. To evaluate the cavitation resistance a total of 60 cylindrical specimens and 60 companion cubes were tested in the laboratory respectively. The results indicate that cavitation resistance of concrete degrades significantly as the L.A. abrasion value of aggregates goes beyond the 30% value. Incorporation of pozzolanic admixtures was seemed to be beneficial to enhance the cavitation resistance of concrete. Influence of other material parameters on the cavitation resistance of concrete was also noted and important observations have been made in the paper.

• 핵의학기술
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• 제16권2호
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• pp.156-161
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• 2012

IRMA법의 실험결과 측정 시 각 축의 설정과 곡선 유형에 따라서 값이 다르게 계산되어 나온다. 시약의 안내서에 있는 대로 설정을 하되 안내가 되어 있지 않은 경우에는 안내서의 도표를 참고하여 설정을 하거나. 어려가지 실험을 통해서 가장 최적화된 설정 값을 찾아내야 한다. 본 실험에서 Immunotech사의 TSH에서는 Linear-Logit 값이 가장 좋은값을 나타낸다고 사료된다. 작은 규모의 실험실에서 감마카운터가 고장 시 SR-300을 이용하여 CPM만 측정 후 EXCEL을 이용하여 결과값을 계산 후 보고해도 좋을 것같다.

• Korean Journal of Radiology
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• 제22권3호
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• pp.344-353
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• 2021

Objective: The mitotic count of gastrointestinal stromal tumors (GIST) is closely associated with the risk of planting and metastasis. The purpose of this study was to develop a predictive model for the mitotic index of local primary GIST, based on deep learning algorithm. Materials and Methods: Abdominal contrast-enhanced CT images of 148 pathologically confirmed GIST cases were retrospectively collected for the development of a deep learning classification algorithm. The areas of GIST masses on the CT images were retrospectively labelled by an experienced radiologist. The postoperative pathological mitotic count was considered as the gold standard (high mitotic count, > 5/50 high-power fields [HPFs]; low mitotic count, ≤ 5/50 HPFs). A binary classification model was trained on the basis of the VGG16 convolutional neural network, using the CT images with the training set (n = 108), validation set (n = 20), and the test set (n = 20). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated at both, the image level and the patient level. The receiver operating characteristic curves were generated on the basis of the model prediction results and the area under curves (AUCs) were calculated. The risk categories of the tumors were predicted according to the Armed Forces Institute of Pathology criteria. Results: At the image level, the classification prediction results of the mitotic counts in the test cohort were as follows: sensitivity 85.7% (95% confidence interval [CI]: 0.834-0.877), specificity 67.5% (95% CI: 0.636-0.712), PPV 82.1% (95% CI: 0.797-0.843), NPV 73.0% (95% CI: 0.691-0.766), and AUC 0.771 (95% CI: 0.750-0.791). At the patient level, the classification prediction results in the test cohort were as follows: sensitivity 90.0% (95% CI: 0.541-0.995), specificity 70.0% (95% CI: 0.354-0.919), PPV 75.0% (95% CI: 0.428-0.933), NPV 87.5% (95% CI: 0.467-0.993), and AUC 0.800 (95% CI: 0.563-0.943). Conclusion: We developed and preliminarily verified the GIST mitotic count binary prediction model, based on the VGG convolutional neural network. The model displayed a good predictive performance.

• 대한임상검사과학회지
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• 제36권2호
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• pp.239-244
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• 2004

Recently automatic equipment has been well popularized for the erythrocyte sedimentation rate, a widely used test, but no standard quality control has been established yet. Thus, we are going to report a case that established and applied a quality control method using the TEST 1 automatic analyzer. For internal quality control, we adopted the repeatability test through comparison with daily mean check, with a manual method using patients' specimens and with the results of a test on the previous day. In order to set the tolerance standard for each quality control method, we compared the results of 50 specimens that showed a wide range of ESR results and examined correlation and differences according to result. After setting the tolerance standard, we applied the standard at tertiary university hospitals for 120 days and investigated positive rates and re-examination rates. If the tolerance standard was exceeded, the cause was also identified. We selected a specimen of below 25 mm/hr (T1), one between 26-50 mm/hr (T2) and one of over 51 mm/hr (T3) at random. The correlation between the manual method and the automatic method was quite high (r=0.98), and it is found appropriate to set based on differences in result values below 25 mm/hr, the upper limit of the reference value, and based on differences in the percentage of result values above 25 mm/hr. Accordingly, we set the criteria for rejection above 10 mm/hr and above 20%. When the criteria were applied in the laboratory, 1.7% of specimens in the range of T1, 8.3% of those in the range of T2 and 7.5% of those in the range of T3 were rejected. Because all the rejected ones fell within the tolerance limit in re-examination calibration verification was not carried out. With the wide popularization of erythrocyte sedimentation rate analyzers that can carry out a lot of tests quickly using automatic methods, it is necessary to improve the reliability of test results by establishing internal quality control policies. We expect that an agreed standard quality control method may be established based on the method proposed in this study.

• 소성∙가공
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• 제4권1호
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• pp.9-16
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• 1995

Model material technique, which requires only the small space of experimental set-up and low cost for experiment, is used to estimate the deformed profile and the forging load in rotary forging. The materials and working conditions are determined to satisfy the similitude conditions between the model test and the prototype test. The model material of the so-called plasticine and the mild steel are chosen as specimens, and they represent almost the same value of strain gardening exponent in the stress-strain relationship. Lubricant in the model test is also carefully selected so that it gives the same frictional conditions at the tool-specimen interface. Experiments for two kinds of specimens are carried out in each testing equipment at room temperatue. From the experiments the deformed dimensions and the forging loads are measured and compared with each other by using the simulation coefficients. It is shown that there are good agreements between the model test and the prototype test. Finally, for verifying the availability of the model material technique this mathod is applied to forging of bevel gear product. the good result is obained which can demonstrate that the model material technique is very efficent for estimating or developing a new process.

• 한국수산과학회지
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• 제1권2호
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• pp.121-127
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• 1968

This research has been dealt with the nutritional component analysis of two kinds of non-edible marine algae, Sargassum herneri (Turner) C. Ag. and Zostera marina Linne which grow abundantly around the southern coast of Korea, These marine algae were mixed in several kinds of samples rates with the combined feed for poultry sold in the market. These were given to 35 chicken in seven test divisions respectively. We have experimented with 35 chicken grown up for two weeks after hatchout. The combined food for poultry obtained from the market was set up as control divisions. The experiments were as follows: 1) The average weight increase in each test division during feeding (Table 5, Fig.2). 2) Food conversion rate and food efficiency in each test division (Table 7). 3) The comparison of digestive rate of crude protein during feeding (Table 8), The results were as follows: 1) The weight increasing rate of the test animal stock fed the food containing $5\~10\%$ of Sargassum horneri (Turner) C. Ag. powder was higher than the rate of those fed only market food for poultry. 2) The stock given food containing $10\%$ Zostera marine powder showed lower growth than the control divison. 3) No apparent trouble owing to salt component involved in the marine algae was found. 4) The stock given food containing sodium glutaminate and Sargassum horneri (Turner) C. Ag. had better result than that without sodium glutaminate.

• 한국도서관정보학회지
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• 제47권2호
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• pp.329-358
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• 2016

이 연구는 아동의 독서태도를 다양한 측면에서 측정할 수 있는 검사도구를 개발하는 데에 목적이 있다. 이에 따라 선행 독서태도 검사 도구, 독서태도 모델과 독서태도에 관한 암묵적 지식 연구를 토대로 구성요인을 설정하고 문항을 작성하였다. 검사도구의 타당도와 신뢰도 검증을 위해 초등학교 4-6학년 학생을 대상으로 1차와 2차 검사를 실시하였다. 독서태도 검사도구에 대한 탐색적 요인분석을 통해 3개의 구성요인에서 8개의 하위요인을 추출하였고, 추출된 8개의 요인은 전체변량의 66.29%를 설명하였다. 문항내적 상관계수 r값은 모든 문항에서 0.4이상으로 나타났고, 독서태도 검사도구의 Cronbach ${\alpha}$값이 0.950으로 나타나 개발된 독서태도 검사도구의 신뢰도와 타당도가 양호함을 확인하였다. 따라서 인지, 정서, 행동의지를 독서태도 구성요인으로 하고 독서효용성과 독서효능감, 여가, 자극, 몰입, 표현, 학습, 적극성을 하위요인으로 하는 독서태도 검사도구는 아동의 독서태도에 관한 다양한 측면을 검사하기에 유용한 도구로 기능할 수 있다는 점을 제시하고 있다.