• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.3
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• pp.221-230
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• 2001

This study was performed to evaluate hard tissue cephalometric norms for Korean adults which can be implemented in surgical orthodontic treatment planning using selected horizontal reference plane especially for Koreans (Male: $SN-7.5^{\circ}$, Female: $SN-9.0^{\circ}$) and a simplified analytical method. 70 males and 70 females consisting of freshmen of Yonsei University from 1996 to 1997 and students from the Dental College of Yonsei University were chosen according to clinical examination and cephalometric analysis. The samples had normal profiles, normal anteroposterior skeletal relationship(ANB angle of $0^{\circ}$ to $4^{\circ}$ and Wits appraisal of -4.0mm to 0mm), and Class I molar and canine relationship. They had no missing or supernumerary teeth and had no experience of orthodontic or prosthetic treatment. After the selection of 23 landmarks and the construction of horizontal and vertical reference lines, 22 skeletal and 12 dental measurements were taken. These consisted of vertical and horizontal linear measurements and angular measurements. The results were as follows. 1. Mean and standard deviation of the measurements were calculated for males and females. 2. Most of the skeletal vertical measurements, and maxillary and mandibular length were bigger in males than females. Whereas anterior facial height ratio(N-ANS/ANS-Me) as well as maxillary and mandibular antero-posterior position in relation to the vertical reference line(N-perpendicular) showed no signigicant difference between sexes. 3. Maxillary and mandibular dental antero-posterior position in relation to the vertical reference line(N-perpendicular) showed no significant difference between sexes. 4. The upper incisor show(U1-Stms) was $2.1{\pm}1.7mm$ in males and $3.3{\pm}1.7mm$ in females. In this study, hard tissue cephalometric norms of Korean adults for orthognathic surgery were obtained.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.14
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• pp.5815-5818
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• 2014

For an exact comparison of mRNA transcription in different samples or tissues with real time quantitative reverse transcription-polymerase chain reaction (qRT-PCR), it is crucial to select a suitable internal reference gene. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and beta-actin (ACTB) have been frequently considered as house-keeping genes to normalize for changes in specific gene expression. However, it has been reported that these genes are unsuitable references in some cases, because their transcription is significantly variable under particular experimental conditions and among tissues. The present study was aimed to investigate which reference genes are most suitable for the study of gastric cancer tissues using qRT-PCR. 50 pairs of gastric cancer and corresponding peritumoral tissues were obtained from patients with gastric cancer. Absolute qRT-PCR was employed to detect the expression of GAPDH, ACTB, RPII and 18sRNA in the gastric cancer samples. Comparing gastric cancer with corresponding peritumoral tissues, GAPDH, ACTB and RPII were obviously upregulated 6.49, 5.0 and 3.68 fold, respectively. Yet 18sRNA had no obvious expression change in gastric cancer tissues and the corresponding peritumoral tissues. The expression of GAPDH, ${\beta}$-actin, RPII and 18sRNA showed no obvious changes in normal gastric epithelial cells compared with gastric cancer cell lines. The carcinoembryonic antigen (CEA), a widely used clinical tumor marker, was used as a validation gene. Only when 18sRNA was used as the normalizing gene was CEA obviously elevated in gastric cancer tissues compared with peritumoral tissues. Our data show that 18sRNA is stably expressed in gastric cancer samples and corresponding peritumoral tissues. These observations confirm that there is no universal reference gene and underline the importance of specific optimization of potential reference genes for any experimental condition.

• Korean Journal of Agricultural Science
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• v.38 no.2
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• pp.277-284
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• 2011

The compositions of health functional food products (HFFP; 18 products) containing gamma linolenic acid (GLA; $C_{18:3}$, n-6) and omega-3 fatty acids (EPA and DHA) were investigated. The contents of index components (especially, GLA and omega-3) in HFFPs were monitored by GC-FID analysis. Among the GLA products (sample No. 1~8), the content of GLA in most samples (except sample No.6) ranged from 8.04 to 9.98 g/100 g. These results were suitable for the reference standard (more 7.0 g/100 g) of HFF. In the omega-3 products (sample No. 10 and 15) derived from harp seal oil (HSO), the total contents of EPA and DHA were 14.21-15.98 g/100 g, respectively. These values were suitable for the reference standard (more 12.0 g/100 g) of HFF. Besides, among the omega-3 products (sample No.9, 11~14, 16~18) derived from fish oil, the total content of EPA and DHA ranged from 24.11 to 31.20 g/100 g. These results were suitable for the reference standard (more 18.0 g/100 g) of HFF. In the result of TLC analysis, the HFFPs of 18 were mainly composed of triacylglycerols (TAGs). The content of trans fatty acid in 18 HFFPs was detected in less than 0.30 g/100 g. For the detection of trans fatty acid, $^1H$-NMR (600 MHz) can be used because chemical shift of trans fatty acid was observed at 5.3 ppm in this study.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.177-180
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• 2006

This study is to make a basic study if solid zinc (Zn) can be used for buried reference electrode, so we examined the adequacy of zinc as reference electrode by using zinc which showed regular electrode for buried period. The deference of electric potential if zinc electrode for corrosion factor such as soil resistivity or pH didn't show fixed trend and there was no clear trend on the change of measurement period. From field test, it is known that the natural electric potential difference of CSE electrode and zinc electrode is 1,100mV, but the electric potential of zinc electrode for CSE electrode in the natural soil and copying soil was 1,094~1,158mV. There was no fixed trend on the change of measurement period and electric potential difference of zinc electrode for corrosion factors such as soil resistivity or pH. Consequently, there was 40~60mV of electric potential difference in every copying soil during the experiment measurement.

• Journal of Mushroom
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• v.16 no.3
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• pp.140-146
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• 2018

Pleurotus eryngii is one of the most commercially important mushrooms cultivated in Korea. However, the shelf-life of the fruiting body is short, limiting its export. A new hybrid strain H17 of P. eryngii was developed to extend the shelf-life by mono-mono crossing between monokaryotic strains derived from DanBi and KNR2774. Although the cultivation period of H17 was slightly longer than that of the reference cultivar Kenneutari No.2, the quality did not change and remained normal after a period of 65.0 days at $4^{\circ}C$. This result was significantly different from that of the reference cultivar Kenneutari No.2. Analysis of the genetic characteristics of the new hybrid strain H17 revealed a different profile from that of the parental and reference cultivars when random amplification of polymorphic DNA (RAPD) primers was used. These results demonstrate that H17 is a new cultivar with improved storability after harvesting.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.3
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• pp.592-606
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• 2011

Currently, the development of multimedia communication has progressed so rapidly that the video program service has become a requirement for ordinary customers. The quality of experience (QoE) for the visual signal is of the fundamental importance for numerous image and video processing applications, where the goal of video quality assessment (VQA) is to automatically measure the quality of the visual signal in agreement with the human judgment of the video quality. Considering the codec effect to the video quality, in this paper an efficient non-reference (NR) VQA algorithm is proposed which estimates the video quality (VQ) only by utilizing the distorted video signal at the destination. The VQA feature vectors (FVs) which have high relationships with the subjective quality of the distorted video are investigated, and a hybrid NR VQA (HNRVQA) function is established by considering the multiple FVs. The simulation results, testing on the SDTV programming provided by VCEG Phase I, show that the proposed algorithm can represent the VQ accurately, and it can be used to replace the subjective VQA to measure the quality of the video signal automatically at the destinations.

• Imaging Science in Dentistry
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• v.41 no.2
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• pp.53-57
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• 2011

Purpose : The purpose of this study was to evaluate the diagnostic performance of dental students in detection of mandibular condyle fractures and the effectiveness of reference panoramic images. Materials and Methods : Forty-six undergraduates evaluated 25 panoramic radiographs for condylar fractures and the data were analyzed through receiver operating characteristic (ROC) analysis. After a month, they were divided into two homogeneous groups based on the first results and re-evaluated the images with (group A) or without (group B) reference images. Eight reference images included indications showing either typical condylar fractures or anatomic structures which could be confused with fractures. Paired t-test was used for statistical analysis of the difference between the first and the second evaluations for each group, and student�fs t-test was used between the two groups in the second evaluation. The intra- and inter-observer agreements were evaluated with Kappa statistics. Results : Intra- and inter-observer agreements were substantial (k=0.66) and moderate (k=0.53), respectively. The area under the ROC curve (Az) in the first evaluation was 0.802. In the second evaluation, it was increased to 0.823 for group A and 0.814 for group B. The difference between the first and second evaluations for group A was statistically significant (p<0.05), however there was no statistically significant difference between the two groups in the second evaluation. Conclusion : Providing reference images to less experienced clinicians would be a good way to improve the diagnostic ability in detecting condylar fracture.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.5
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• pp.611-616
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• 2018

In the cost based pool market in Korea, there is no compensation of reactive power because the fuel cost for reactive power is relatively low compared to that of active power. However, the change of energy paradigm in the future, such as widespread integration of distributed renewable energy source, will prevent the system operator from mandating the reactive power supply without any compensation. Thus, in this study, we propose the reference voltage of the 345 kV transmission system that minimizes the reactive power supply. This is closely related to the economic dispatch of reactive power aiming at minimizing the compensation cost for the reactive power service. In order to verify the effectiveness of the proposed reference voltage, the simulations are performed using the IEEE 14 bus system and the KEPCO real networks. The simulation results show that a voltage lower than the current reference value is recommended to reduce the reactive power supply and also suggest that the current voltage specification for the 345 kV system needs to be reviewed.

• Korean Journal of Child Studies
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• v.33 no.5
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• pp.53-70
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• 2012

The purpose of this study was to investigate the effects of task conditions (physical similarity between the spatial product and the reference space, presentation place of the spatial product) on children's spatial representation. The participants consisted of 40 3-year-olds and 40 4-year-olds. The results of this study are as follows. Both 3-year-olds and 4-year-olds were capable of a greater degree of spatial representation when there was a high level of physical similarity between the spatial product and the reference space, and when the presentation place of the spatial product was in the reference space. 4-year-olds were capable of more accurate spatial representation than 3-year-olds. There was no significant difference in the children's spatial representation depending on the type of spatial product (scale model, map). The results revealed that the physical similarity between the spatial product and the reference space and the presentation place of the spatial product are essential in young children's spatial representation. Additionally, the results indicated that spatial representation of children develops gradually from when they are three to when they turn four.

• Culinary science and hospitality research
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• v.13 no.2
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• pp.123-135
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• 2007

This study intended to determine how price-ending types used for menu products affected consumers' price evaluation and value perception and such behavioral intentions as purchase intention and search intention. The collected data went through statistical processing, including frequency analysis, factor analysis, T-test and ANOVA using an $SPSS/PC^+$ 12.0 statistical package. The results can be summarized as follows: First, as for differences in internal reference price by ending, internal reference price was lower if menu ending was an odd number than it was an even number, which indicates that consumers tend to consider the price of the menu products to be lower if the ending of menu products is an odd number. Second, menu price-ending was found to have significant differences on consumers' purchase intention, search intention, and value perception. But the results of two-way ANOVA showed that price ending by restaurant types had no effect on consumers' search intention and restaurant type. This study suggested a desirable external reference price-ending type for menu products as one of sales promotion strategies to menu products planners and drew up a concrete plan to determine which price-ending type is useful by consumers' personal properties.