• Progress in Medical Physics
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• v.25 no.3
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• pp.176-184
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• 2014

In this study, we compared dose distributions from simultaneously integrated boost (SIB) method versus the RTOG 0631 protocol for spine radiosurgery. Spine radiosurgery plans were performed in five patients with localized spinal metastases from hepatocellular carcinoma. The computed tomography (CT) and T1- and T2-weighted magnetic resonance imaging (MRI) were fused for delineating of GTV and spinal cord. In SIB plan, the clinical target volume (CTV1) was included the whole compartments of the involved spine, while RTOG 0631 protocol defines the CTV2 as the involved vertebral body and both left and right pedicles. The CTV2 includes transverse process and posterior element according to the extent of GTV. The doses were prescribed 18 Gy to GTV and 10 Gy to CTV1 in SIB plan, while the prescription of RTOG 0631 protocol was applied 18 Gy to CTV2. The results of dose-volume histogram (DVH) showed that there were competitive in target coverage, while the doses of spinal cord and other normal organs were lower in SIB method than in RTOG 0631 protocol. The 85% irradiated volume of VB in RTOG 0631 protocol was similar to that in the SIB plan. However, the dose to normal organs in RTOG 0631 had a tendency to higher than that in SIB plan. The SIB plan might be an alternative method in case of predictive serious complications of surrounded normal organs. In conclusion, although both approaches of SIB or RTOG 0631 showed competitive planning results, tumor control probability (TCP) and normal tissue complication probability (NTCP) through diverse clinical researches should be analyzed in the future.

• Journal of dental hygiene science
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• v.10 no.3
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• pp.131-139
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• 2010

The purpose of this study was to evaluate smoking patterns, oral health behavior and perception of dental healthcare of military personnel in the South Korea Army. All 367 subjects were surveyed by the structured questionnaires with convenience sampling method. The questionnaires were consisting of 22 items. Depending on the conditions of military training, the distribution and differences of smoking patterns and oral behaviors were evaluated by frequency test, Weighted Kappa, Paired t-test and ANOVA. The differences of oral health perception on smoking were demonstrated by Mantel-Haenszel Chi-square test. In addition, Generalized Estimating Equation (GEE) was used to estimate the effects of oral behavior for the conditions of military training and smoking. The number of cigarette during military training period was similar to that during non-military training (p=0.109). The perception of smokers such as smoking effect on oral health, oral health and systemic health, and need of education for smoking cessation was significantly lower than non-smokers (p=0.0095, p=0.0007, and p<0.0001). The probability that toothbrush frequency per day was only one was associated with higher during military training period than non-military training (OR=9.29, 95% CI 5.05-17.07). Moreover, the probability that hours of toothbrush were less than one minute was associated with higher during military training than non-military training (OR=2.19, 95% CI 1.78-2.71). To improve knowledge, attitude, and behavior of oral health for the members, the army needs to develop oral health education and tobacco cessation programs. In particular, motivation and practice for oral health care are required to improve poor oral health behavior during the military training.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.2
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• pp.45-58
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• 2012

For the development of reference values and evaluation of water quality in various environmental conditions, we divided the coastal region around Korean peninsular into 5 distinctive ecological regions based on the influence of surface current, depth, tidal range, turbidity, and climate condition. We used national marine environment monitoring data collected by National Fisheries Research & Development Institute(NFRDI) from 2000-2009. For the reference values, we used maximum seasonal mean from 2000 to 2007 for DIN, DIP, and chlorophyll-a and minimum seasonal mean for secchi depth measured at stations without the influence of river runoff in each ecological regions. For the reference value of bottom dissolved oxygen saturation, we used minimum mean value of 90% calculated from minimal riverine influence stations of whole regions. We calculated enrichment score for each assessment criteria. The enrichment score of DIN, DIP, and Chlorophyll-a was 1 (=< reference value), 2 (< 110% of reference value), 3 (< 125% of reference value), 4 (< 150% of reference value), and 5 (> 150% of reference value). The enrichment score of DO saturation and Secchi depth was 1 (> reference value), 2 (> 90% of reference value), 3 (>75 % of reference value), 4 (> 50% of reference value), and 5 (< 50% of reference value). We calculated water quality index using weighted linear combination of five enrichment score for the comparison of whole regions. From the water quality index distribution calculated from all stations between 2000 and 2007 period, we classified into 5 grade based on the standard deviation calculated from total water quality index. We assigned grade very good(I), good(II), moderate(III), bad(IV), and very bad(V) when the water quality index was less than 23, minimum + 1 sd, +2 sd, +3 sd, and grater than minium+ 3 sd, respectively.

• Journal of Nutrition and Health
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• v.47 no.4
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• pp.247-257
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• 2014

Purpose: It is reported that most senior people consume a high carbohydrate diet, while a high carbohydrate diet could contribute to the risk of chronic disease. The aim of this study is to determine whether a high carbohydrate diet can increase the risk of chronic disease in elderly Koreans. Methods: Using the 2007-2009 Korean National Health Nutrition Examination Survey data, out of a total of 3,917 individuals aged 65 and above, final 1,535 subjects were analyzed, divided by dietary carbohydrate energy ratio into two groups of moderate carbohydrate ratio (MCR, 55-70%) and excessive carbohydrate ratio (ECR, > 70%). All data were processed after the application of weighted value, using a general linear model or logistic regression. Results: Eighty one percent of elderly Koreans consumed diets with carbohydrate energy ratio above 70%. The ECR group included more female subjects, rural residents, lower income, and lower education level. The ECR group showed lower waist circumference, lower diastolic blood pressure, and lower frequency of consumption of meat and egg, milk, and alcohol. The intake of energy and most nutrients, with the exception of fiber, potassium, vitamin A, and carotene, was lower in the ECR group compared to the MCR group. When analyzed by gender, the ECR group showed lower risk of dyslipidemia in male and obesity in female subjects, even though the ECR group showed low intake of some nutrients. No difference in the risk of hypertension, diabetes, and anemia was observed between the two groups in male or female subjects. Conclusion: This result suggested that a high carbohydrate diet would not be a cause to increase the risk of chronic disease in the elderly. Further study is needed in order to determine an appropriate carbohydrate energy ratio for elderly Koreans to reduce the risk of chronic disease.

• Korean Journal of Veterinary Research
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• v.37 no.1
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• pp.167-176
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• 1997

The present investigation was focussed mainly on the development of the tumors and proliferating cells on the intestinal tracts of 1, 2-dimethyl-hydrazine(DMH)-treated young or adult rats. 26 rats(Wistar, 14 young rats weighting approximately 130~180gm and 12 adult rats weighting approximately 500~550gm) were given subcutaneously once weekly with 20mg of DMH/kg body weight(BW)/week for 8~22 weeks. Individual body weight were recorded weekly at the same day and time. The rats were killed at 8, 13, 15. 17, 19, 21 and 22 weeks. The intestinal tracts were opened longitudinally and carefully examined for tumors. The localization, number, and size of tumors were noted. Tumor-bearing areas were dissected out and fixed on neutral buffered 10% formalin and normal-looking mucosa from 8~22 weeks rats were also taken for fixation. Paraffin sections were stained by H-E for histopathological examination or with immunohistochemical stain for bromodeoxyuridine(Brdur) positive cells. 1. The growth proportion of body weight appeared to be decreased in the DMH-treated young rats than in control young rats and body weight of DMH-treated adult rats appeared to be 13.4% or less lower than weighted on 0 week. 2. Macroscopically, the developed tumors in the intestinal tracts were not observed as early as the 13 weeks after DMH treatment. The number of developed tumors per rat was found to be 14.3, 18.8, 22.3 in 15, 17 and 22 weeks. The numbers of tumors in intestinal regions per rat were 2.1, 4.3, 5.4, 2.5 in duodenum, jejunum, ilium and colon on 15 weeks, 2.3, 6.4, 7.8, 2.3, on 17 weeks, and 2.7, 9.3, 9.0, 1.3 on 22 weeks, respectively and the ileum and jejunum were higher in appearance rate of tumors and tumor types are dome shapes and diameter of largest tumor were 6.3mm. 3. Histopathologically, intestinal mucosa were thickened by the irregular distorted and distended crypts following hyperplasia. The tumors developed on the mucosa and submucosa and were recognized to be adenocarcinoma. 4. Immunohistochemically, the labeling index(LI) was calculated as the ratio of the number of Brdur-labeled cells to the total number of column cells of the crypts with longitudinal axis. LI of Brdur positive cells per crypt were 5.6%, 8.0% on small intestine of control and 22 week group, respectively and 3.7%, 12.7% on large intestine of control and 22 week group, respectively and were appeared to be increase in 22 week group than in control group and to be more number of proliferating cells in 22 week group than in control group. 5. LI of Brdur positive cells in 1, 2, 3, 4, 5 segments of crypt column were 11.7%, 10.7%, 3.8%, 0.6%, 0% in small intestine of control group and 23.5%, 11.8%, 2.3%, 2.4%, 0.8% in small intestine of 22 week group, and 5.4%, 7.4%, 3.8%, 1.0%, 0.4% in large intestine of control group and 29.5%, 20.3%, 5.9%, 6.3%, 1.3% in large intestine of 22 week group respectively. So results indicate that the number of proliferating cells by DMH treatment increase and were concentrated on the 1, 2 segments of crypt columns.

• Journal of Korea Water Resources Association
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• v.55 no.12
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• pp.1041-1052
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• 2022

This study is to estimate the optimal ecological flow and analysis the spatial distribution of fish habitat for Andong dam downstream reach (4,565.7 km²) using PHABSIM (Physical Habiat Simulation System) and River2D. To establish habitat models, the cross-section informations and hydraulic input data were collected uisng the Nakdong river basic plan report. The establishment range of PHABSIM was set up about 410.0 m from Gudam streamflow gauging station (GD) and about 6.0 km including GD for River2D. To select representative fish species and construct HSI (Habitat Suitability Index), the fish survey was performed at Pungji bridge where showed well the physical characteristics of target stream located downstream of GD. As a result of the fish survey, Zacco platypus was showed highly relative abundance resulting in selecting as the representative fish species, and HSI was constructed using physical habitat characteristics of the Zacco platypus. The optimal range of HSI was 0.3~0.5 m/s at the velocity suitability index, 0.4~0.6 m at the depth suitability index, and the substrate was sand to fine gravel. As a result of estimating the optimal ecological flow by applying HSI to PHABSIM, the optimal ecological flow for target stream was 20.0 m³/sec. As a result of analysis two-dimensional spatial analysis of fish habitat using River2D, WUA (Weighted Usable Area) was estimated 107,392.0 m²/1000 m under the ecological flow condition and it showed the fish habitat was secured throughout the target stream compared with Q₃₅₅ condition.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.2
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• pp.63-77
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• 2022

Our aim was to reduce estimation errors of a wind velocity model used as an early warning system for weather risk management in the agricultural sector. The Rural Development Administration (RDA) agricultural weather observation network's wind velocity data and its corresponding estimated data from January to December 2020 were used to calculate linear regression equations (Y = aX + b). In each linear regression, the wind estimation error at 87 points and eight time slots per day (00:00, 03:00, 06:00, 09.00, 12.00, 15.00, 18.00, and 21:00) is the dependent variable (Y), while the estimated wind velocity is the independent variable (X). When the correlation coefficient exceeded 0.5, the regression equation was used as the wind velocity correction equation. In contrast, when the correlation coefficient was less than 0.5, the mean error (ME) at the corresponding points and time slots was substituted as the correction value instead of the regression equation. To enable the use of wind velocity model at a national scale, a distribution map with a grid resolution of 250 m was created. This objective was achieved b y performing a spatial interpolation with an inverse distance weighted (IDW) technique using the regression coefficients (a and b), the correlation coefficient (R), and the ME values for the 87 points and eight time slots. Interpolated grid values for 13 weather observation points in rural areas were then extracted. The wind velocity estimation errors for 13 points from January to December 2019 were corrected and compared with the system's values. After correction, the mean ME of the wind velocities reduced from 0.68 m/s to 0.45 m/s, while the mean RMSE reduced from 1.30 m/s to 1.05 m/s. In conclusion, the system's wind velocities were overestimated across all time slots; however, after the correction model was applied, the overestimation reduced in all time slots, except for 15:00. The ME and RMSE improved b y 33% and 19.2%, respectively. In our system, the warning for wind damage risk to crops is driven by the daily maximum wind speed derived from the daily mean wind speed obtained eight times per day. This approach is expected to reduce false alarms within the context of strong wind risk, by reducing the overestimation of wind velocities.

• Asia Marketing Journal
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• v.14 no.1
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• pp.53-81
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• 2012

Constructing attractive bundle offers depends on more than an understanding of the distribution of consumer preferences. Consumers are also sensitive to the framing of price information in a bundle offer. In classical economic theory, consumers' utility should not change as long as the total price paid stays same. However, even when total prices are identical, consumers' preferences toward a bundle product could be different depending on the format of price presentation and the locus of price discount. A weighted additive model predicts that the impact of a price discount on the overall evaluation of the bundle will be greater when the discount is assigned to the more important product in the bundle(Yadav 1995). Meanwhile, a reference dependent model asserts that it is better to assign a price discount to a tie-in component that has a negative valuation at its current offer price than to a focal product that has a positive valuation at its current offer price(Janiszewski and Cunha 2004). This paper has expanded previous research regarding price discount presentation format, investigating the reasons for mixed results of prior research and presenting new mechanisms for price discount framing effect. Prior research has hypothesized that bundling is used to sell a tie-in component with an offer price above the consumer's reference price plus a focal product of the same offer price with reference price(e.g., Janiszewski and Cunha 2004). However, this study suggests that bundling strategy can be used for increasing product's attractiveness through the synergy between components even when offer prices of bundle components are the same with reference prices. In this context, this study employed various realistic bundle sets with same price between offer price and reference price in the experiment. Hamilton and Srivastava(2008) demonstrated that when evaluating different partitions of the same total price, consumers prefer partitions in which the price of the high-benefit component is higher. This study determined that their mechanism can be applied to price discount presentation formats. This study hypothesized that price discount framing effect depends not on the negative perception of tie-in component with offer price above reference price but rather on the consumers' perceived consumption benefit in bundle product. This research also hypothesized that preference for low-benefit discount mechanism is that perceived consumption benefit reduces price sensitivity. Furthermore, this study investigated how consumers' concern for quality in a price discount--a factor not considered in previous research--influences price discount framing. Yadav(1995)'s experiment used only one magazine bundle of relatively low quality uncertainty and could not show the influence of perceived uncertainty of quality. This study assumed that as perceived uncertainty of quality increases, the price sensitivity mechanism for assigning the discount to low-benefit will increase. Further, this research investigated the moderating effect of uncertainty of quality in price discount framing. The results of the experiment showed that when evaluating different partitions of the same total price and the same amount of discounts, the partition that discounts in the price of low benefit component is preferred to the partition that decreases the price of high benefit component. This implies that price discount framing effect depends on the perceived consumption benefit. The results also demonstrated that consumers are more price sensitive to low benefit component and less price sensitive to high benefit component. Furthermore, the results showed that the influence of price discount presentation format on the evaluation of bundle product varies with the perceived uncertainty of quality in high consumption benefit. As perceived uncertainty of quality gradually increases, the preference for discounts in the price of low consumption benefit decreases. Besides, the results demonstrate that as perceived uncertainty of quality gradually increases, the effect of price sensitivity in consumption benefit also increases. This paper integrated prior research by using a new mechanism of perceived consumption benefit and moderating effect of perceived quality uncertainty, thus providing a clearer explanation for price discount framing effect.

• Journal of Intelligence and Information Systems
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• v.19 no.4
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• pp.147-157
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• 2013

With the advent of the digital environment that can be accessed anytime, anywhere with the introduction of high-speed network, the free distribution and use of digital content were made possible. Ironically this environment is raising a variety of copyright infringement, and product images used in the online shopping mall are pirated frequently. There are many controversial issues whether shopping mall images are creative works or not. According to Supreme Court's decision in 2001, to ad pictures taken with ham products is simply a clone of the appearance of objects to deliver nothing but the decision was not only creative expression. But for the photographer's losses recognized in the advertising photo shoot takes the typical cost was estimated damages. According to Seoul District Court precedents in 2003, if there are the photographer's personality and creativity in the selection of the subject, the composition of the set, the direction and amount of light control, set the angle of the camera, shutter speed, shutter chance, other shooting methods for capturing, developing and printing process, the works should be protected by copyright law by the Court's sentence. In order to receive copyright protection of the shopping mall images by the law, it is simply not to convey the status of the product, the photographer's personality and creativity can be recognized that it requires effort. Accordingly, the cost of making the mall image increases, and the necessity for copyright protection becomes higher. The product images of the online shopping mall have a very unique configuration unlike the general pictures such as portraits and landscape photos and, therefore, the general image watermarking technique can not satisfy the requirements of the image watermarking. Because background of product images commonly used in shopping malls is white or black, or gray scale (gradient) color, it is difficult to utilize the space to embed a watermark and the area is very sensitive even a slight change. In this paper, the characteristics of images used in shopping malls are analyzed and a watermarking technology which is suitable to the shopping mall images is proposed. The proposed image watermarking technology divide a product image into smaller blocks, and the corresponding blocks are transformed by DCT (Discrete Cosine Transform), and then the watermark information was inserted into images using quantization of DCT coefficients. Because uniform treatment of the DCT coefficients for quantization cause visual blocking artifacts, the proposed algorithm used weighted mask which quantizes finely the coefficients located block boundaries and coarsely the coefficients located center area of the block. This mask improves subjective visual quality as well as the objective quality of the images. In addition, in order to improve the safety of the algorithm, the blocks which is embedded the watermark are randomly selected and the turbo code is used to reduce the BER when extracting the watermark. The PSNR(Peak Signal to Noise Ratio) of the shopping mall image watermarked by the proposed algorithm is 40.7~48.5[dB] and BER(Bit Error Rate) after JPEG with QF = 70 is 0. This means the watermarked image is high quality and the algorithm is robust to JPEG compression that is used generally at the online shopping malls. Also, for 40% change in size and 40 degrees of rotation, the BER is 0. In general, the shopping malls are used compressed images with QF which is higher than 90. Because the pirated image is used to replicate from original image, the proposed algorithm can identify the copyright infringement in the most cases. As shown the experimental results, the proposed algorithm is suitable to the shopping mall images with simple background. However, the future study should be carried out to enhance the robustness of the proposed algorithm because the robustness loss is occurred after mask process.

• Journal of Intelligence and Information Systems
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• v.16 no.3
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• pp.77-97
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• 2010

Market timing is an investment strategy which is used for obtaining excessive return from financial market. In general, detection of market timing means determining when to buy and sell to get excess return from trading. In many market timing systems, trading rules have been used as an engine to generate signals for trade. On the other hand, some researchers proposed the rough set analysis as a proper tool for market timing because it does not generate a signal for trade when the pattern of the market is uncertain by using the control function. The data for the rough set analysis should be discretized of numeric value because the rough set only accepts categorical data for analysis. Discretization searches for proper "cuts" for numeric data that determine intervals. All values that lie within each interval are transformed into same value. In general, there are four methods for data discretization in rough set analysis including equal frequency scaling, expert's knowledge-based discretization, minimum entropy scaling, and na$\ddot{i}$ve and Boolean reasoning-based discretization. Equal frequency scaling fixes a number of intervals and examines the histogram of each variable, then determines cuts so that approximately the same number of samples fall into each of the intervals. Expert's knowledge-based discretization determines cuts according to knowledge of domain experts through literature review or interview with experts. Minimum entropy scaling implements the algorithm based on recursively partitioning the value set of each variable so that a local measure of entropy is optimized. Na$\ddot{i}$ve and Booleanreasoning-based discretization searches categorical values by using Na$\ddot{i}$ve scaling the data, then finds the optimized dicretization thresholds through Boolean reasoning. Although the rough set analysis is promising for market timing, there is little research on the impact of the various data discretization methods on performance from trading using the rough set analysis. In this study, we compare stock market timing models using rough set analysis with various data discretization methods. The research data used in this study are the KOSPI 200 from May 1996 to October 1998. KOSPI 200 is the underlying index of the KOSPI 200 futures which is the first derivative instrument in the Korean stock market. The KOSPI 200 is a market value weighted index which consists of 200 stocks selected by criteria on liquidity and their status in corresponding industry including manufacturing, construction, communication, electricity and gas, distribution and services, and financing. The total number of samples is 660 trading days. In addition, this study uses popular technical indicators as independent variables. The experimental results show that the most profitable method for the training sample is the na$\ddot{i}$ve and Boolean reasoning but the expert's knowledge-based discretization is the most profitable method for the validation sample. In addition, the expert's knowledge-based discretization produced robust performance for both of training and validation sample. We also compared rough set analysis and decision tree. This study experimented C4.5 for the comparison purpose. The results show that rough set analysis with expert's knowledge-based discretization produced more profitable rules than C4.5.