• Radiation Oncology Journal
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• v.18 no.4
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• pp.277-282
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• 2000

Purpose : Though It has been known that the to tolerance of the liver to external beam irradiation depends on the irradiated volume and dose, few data exist which Quantify this dependence. However, recently, with the development of three dimensional (3-D) treatment planning, have the tools to Quantify the relationships between dose, volume, and normal tissue complications become available. The objective of this study is to investigate the relationships between normal tissue complication probabili쇼 (WCP) and the risk of radiation hepatitis for patients who received variant dose partial liver irradiation. Materials and Methods : From March 1992 to December 1994, 10 patients with hepatoma and 10 patients with bile duct cancer were included in this study. Eighteen patients had normal hepatic function, but 2 patients (prothrombin time 73$\%$, 68$\%$) had mild liver cirrhosis before irradiation. Radiation therapy was delivered with 10MV linear accelerator, 180$\~$200 cGy fraction per day. The total dose ranged from 3,960 cGy to 6,000 cGy (median dose 5,040 cGy). The normal tissue complication probability was calculated by using Lyman's model. Radiation hepatitis was defined as the development of anicteric elevation of alkaline phosphatase of at least two fold and non-malignant ascites in the absence of documented progressive. Results: The calculated NTCP ranged from 0.001 to 0.840 (median 0.05). Three of the 20 patients developed radiation hepatitis. The NTCP of the patients with radiation hepatitis were 0.390, 0.528, 0.844(median : 0.58$\pm$0.23), but that of the patients without radiation hepatitis ranged fro 0.001 to 0.308 (median .0.09$\pm$0.09). When the NTCP was calculated by using the volume factor of 0.32, a radiation hepatitis was observed only in patients with the NTCP value more than 0.39. By contrast, clinical results of evolving radiation hepatitis were not well correlated with NTCP value calculated when the volume factor of 0.69 was applied. On the basis of these observations, the volume factor of 0.32 was more correlated to predict a radiation hepatitis. Conclusion : The risk of radiation hepatitis was increased above the cut-off value. Therefore the NTCP seems to be used for predicting the radiation hepatitis.

• The KIPS Transactions:PartD
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• v.10D no.6
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• pp.885-896
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• 2003

The typws of service using location Information are being various and extending their domain as wireless internet tochnology is developing and its application par is widespread, so it is prospected that LBS(Location-Based Services) will be killer application in wireless internet services. This location information is basic and high value-added information, and this information services make prior GIS(Geographic Information System) to be useful to anybody. The acquisition of this location information from moving object is very important part in LBS. Also the interfacing of acquisition of moving object between MODB and telecommunication network is being very important function in LBS. After this, when LBS are familiar to everybody, we can predict that LBS system load is so heavy for the acquisition of so many subscribers and vehicles. That is to say, LBS platform performance is fallen off because of overhead increment of acquiring moving object between MODB and wireless telecommunication network. So, to make stable of LBS platform, in this MODB system, acquisition of moving object location par as reducing the number of acquisition of unneccessary moving object location. We study problems in acquiring a huge number of moving objects location and design some acquisition model using past moving patternof each object to reduce telecommunication overhead. And after implementation these models, we estimate performance of each model.

• Journal of Korean Society for Geospatial Information Science
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• v.8 no.1 s.15
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• pp.51-63
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• 2000

Dynamic traffic assignment(DTA) has been a topic of substantial research during the past decade. While DTA is gradually maturing, many aspects of DTA still need improvement, especially regarding its formulation and solution algerian Recently, with its promise for In(Intelligent Transportation System) and GIS(Geographic Information System) applications, DTA have received increasing attention. This potential also implies higher requirement for DTA modeling, especially regarding its solution efficiency for real-time implementation. But DTA have many mathematical difficulties in searching process due to the complexity of spatial and temporal variables. Although many solution algorithms have been studied, conventional methods cannot iud the solution in case that objective function or constraints is not convex. In this paper, the genetic algorithm to find the solution of DTA is applied and the Merchant-Nemhauser model is used as DTA model because it has a nonconvex constraint set. To handle the nonconvex constraint set the GENOCOP III system which is a kind of the genetic algorithm is used in this study. Results for the sample network have been compared with the results of conventional method.

• Korean Journal of Food Science and Technology
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• v.36 no.5
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• pp.701-710
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• 2004

Uncertainty was quantified to evaluate calcium determination result in infant formula with AAS (Atomic Absorption Spectrometry) and ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrometry). Uncertainty sources in measurand, such as sample weight, final volume of sample, sample dilution and the instrumental result were identified and used as parameters for combined standard uncertainty based on the GUM (Guide to the expression of uncertainty in measurement) and Draft EURACHEM/CITAC Guide. Uncertainty components of each sources in measurand were identified as resolution, reproducibility and stability of chemical balance, standard material purity, standard material molecular weight, standard solution concentration, standard solution dilution factor, sample dilution factor, calibration curve, recovery, instrumental precision, reproducibility, and stability, Each uncertainty components were evaluated by uncertainty types and included to calculate combined uncertainty. The kinds of uncertainty sources and components in the analytical method by AAS and ICP-AES were same except sample dilution factor for AAS. The analytical results and combined standard uncertainties of calcium content were estimated within the certification range $(367{\pm}20\;mg/100g)$ of CRM (Certified Reference Material) and were not significantly different between method by AAS followed by ashing and method by ICP-AES followed by acid digestion as $359.52{\pm}23.61\;mg/100g\;and\;354.75{\pm}16.16\;mg/100g$, respectively. Identifying uncertainty sources related with precision, repeatability, stability, and maintaining proper instrumental conditions as well as personal proficiency was needed to reduce analytical error.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.8
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• pp.1296-1303
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• 2014

This study was conducted to develop predictive models for the growth of Bacillus cereus on carrot treated with slightly acidic electrolyzed water (SAcEW) and ultrasonication (US) at different storage temperatures. In addition, the inactivation of B. cereus by US with SAcEW was investigated. US treatment with a frequency of 40 kHz and an acoustic energy density of 400 W/L at $40^{\circ}C$ for 3 min showed the maximum reduction of 2.87 log CFU/g B. cereus on carrot, while combined treatment of US (400 W/L, $40^{\circ}C$, 3 min) with SAcEW reached to 3.1 log CFU/g reduction. Growth data of B. cereus on carrot treated with SAcEW and US at different temperatures (4, 10, 15, 20, 25, 30, and $35^{\circ}C$) were collected and used to develop predictive models. The modified Gompertz model was found to be more suitable to describe the growth data. The specific growth rate (SGR) and lag time (LT) obtained from the modified Gompertz model were employed to establish the secondary models. The newly developed secondary models were validated using the root mean square error, bias factor, and accuracy factor. All results of these factors were in the acceptable range of values. After compared SGR and LT of B. cereus on carrot, the results showed that the growth of B. cereus on carrot treated with SAcEW and US was slower than that of single treatment. This result indicates that shelf life of carrot treated with SAcEW and US could be extended. The developed predictive models might also be used to assess the microbiological risk of B. cereus infection in carrot treated with SAcEW and US.

• Journal of The Korean Association For Science Education
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• v.12 no.1
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• pp.75-92
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• 1992

The purpose of this study was to point out the problems of the competency exam for college education, a new college entrance exam, and to suggest the improvement ideas for it For this purpose, the test items of science inquiry were taken from the first, the second and the third pilot studies of the competency exam for college education which National Institute of Educational Evaluation had done. These tests were administered to 1,223 students of the general high school(422 for the 1st 400 for the 2nd, and 401 for the 3rd test). Also, those students' and the high school science teacher's opinions about the tests and the new college entrance exam were surveyed. The evaluation objectives of those test items were analyzed and the test item analyses were done. The results were as follows; (1) The evaluation objective analysis showed that most of the test The purpose of this study was to point out the problems of the competency exam for college education, a new college entrance exam, and to suggest the improvement ideas for it For this purpose, the test items of science inquiry were taken from the first, the second and the third pilot studies of the competency exam for college education which National Institute of Educational Evaluation had done. These tests were administered to 1,223 students of the general high school(422 for the 1st, 400 for the 2nd, and 401 for the 3rd test). Also, those students' and the high school science teacher's opinions about the tests and the new college entrance exam were surveyed. The evaluation objectives of those test items were analyzed and the test item analyses were done. The results were as follows; (1) The evaluation objective analysis showed that most of the test items were constructed based on the evaluation framework which was composed of scientific inquiry thinking ability, science concept, and scientific inquiry context dimensions. But, those items were unevenly distributed into a few areas of the evaluation framework. (2) The boys had higher mean scores than the girls in all of the tests, but these differences were not statistically significant. The natural science course students had significantly higher mean than the humanities course students in all of the test:(1st, F=12.643, p=0.0004 ; 2nd, F=45.757, p=0.0001 ; 3rd, F=36.162, p=0.0001). A significant interaction of sex and course was found in only 1st test( F=11.352. p=0.0008). (3) Most students answered the test was difficult and they needed more time to finish it Also, they added they had to study in a different way from the traditional one in order to prepare the new college entrance exam. Science teachers answered that those evaluation objectives of the tests corresponded well with the educational objectives of high school science and that the tests were suitable as measuring instruments of the scientific thinking abilities. But they pointed out it would be very difficult for them to teach students for preparing the exam under the exsting educational conditions. To carry out successfully the competency exam for college education, the following improvements were suggested. (1) Good evaluation methodology should be developed. (2) In-service science teacher training models on evaluation should be put in force. (3) Effective teaching models and strategies should be developed.(4) The high school science curriculum should be revised.

• Journal of The Korean Association For Science Education
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• v.31 no.1
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• pp.78-98
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• 2011

The purpose of this study was to analyze elementary school students' interpretation of data characteristics by cognitive style. Participants were elementary students in sixth grade who can use integrated inquiry process skills. The students were divided into two groups, analytic cognitive style and wholistic cognitive style according to their response to Cognitive Style Analysis. They performed scientific interpretation of data activity. To collect data for this study, participants recorded the result on scientific interpretation of data activity paper and researcher recorded the situation on videotape and interviewed with participants after the end of interpretation of data to get additional data. And the findings of this study were as follows: First, the study analyzed interpretation of data characteristics by the operator regarding different situations of interpreting data according to cognitive style. For example, in the intermediate state, analytic-cognitive style students showed high achievement in identifying variables, and wholistic-cognitive style students were active in using prior knowledge to interpret data. Second, the result of analysis on the direction of interpreting data and preference for data types in interpreting data activities according to cognitive style are as follows: Wholistic-cognitive style students showed relatively high perception of information through the top-down approach. On the other hand, analytic-cognitive style students usually used the bottom-up approach gradually expanding detailed information to the scientific question-related answer and showed a preference data of the table type. Through the result, this study aimed to help establish a data interpretation strategy for learners to solve problems based on understanding of interpretation of data characteristics according to learners' cognitive style, and purposed the instruction design suggesting the data requiring various data interpretation strategies to develop learners' data interpretation ability.

• Journal of Mushroom
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• v.11 no.3
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• pp.131-136
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• 2013

The effects of fixed and variable relative humidity on fruiting body formation and characters of Pleurotus eryngii were investigated with normal and thinning treatment plots. In fixed relative humidity, as humidity was lower, period of harvest was longer as well as days for pinheading in the both of normal and thinning plots. In the normal plot, qualities of mushroom were 5.5, 5.8, and 6.3 and yield was 98.6 g per bottle for 90% relative humidity, it was best. In the thinning plot, qualities of mushroom were 7.7, 8.4, and 8.5 and yields were 102.1, 105.8, and 116.9 g at 70, 80, and 90% respectively. In variable relative humidity with a thinning plot, the yield of P. eryngii on condition I(>90% for 1 day ${\rightarrow}$ 85% until thinning(for about 11 days) ${\rightarrow}$ 80%) and III(>90% until pin-heading(about for a week) ${\rightarrow}$ 85% until thinning(about for 5 days) ${\rightarrow}$ 80%) were 85.5 and 87.8 g per bottle, and qualities were 7.8 and 8.0 respectively. For long shelf life and a cultural control of bacterial soft rot disease, the condition I will be more largely adopted by mushroom farmers.

• Journal of Gifted/Talented Education
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• v.26 no.4
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• pp.565-585
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• 2016

This study purpose was to explore whether career maturity and parents-children relationship related factors were differentiated by giftedness, gender and secondary school level (research question 1). In addition, this study focused on the effects of parents-children relationship related factors on career maturity with a comparison on gifted and regular students (research question 2). The sample included 213 gifted middle school and high school students who participated in the Korean gifted education center and 243 regular students. Multivariate analysis of variance was conducted for research question 1, and hierarchical regression analysis was conducted for research question 2. The results of this study showed that (1) gifted students showed a higher level of career maturity, achievement expectation (parents-children relationship), respect (parents-children relationship), discussion and leisure (activity with parents), sharing ordinary life and communication (activity with parents), career support of parents compared to regular students ; (2) Girls showed higher level only in sharing ordinary life and communication compared to boys ; (3) middle school students more highly perceived the parents' achievement expectation and control, respect for parents, activities with parents (discussion and leisure, sharing ordinary life and communication) compared to high school students ; (4) the career support of parents was the strongest predictor of career maturity, and discussion and leisure was also a significant factor predictor of career maturity. Based on these results, it was suggested for parents to support their children's career maturity of both gifted and regular students by increasing frequencies of various activities shared with their children such as discussion and leasure.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.29 no.2
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• pp.109-120
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• 2017

A discounted cost model for preventive maintenance of armor units of rubble-mound breakwaters is mathematically derived by combining the deterioration model based on a discrete-time stochastic process of shock occurrence with the cost model of renewal process together. The discounted cost model of condition-based maintenance proposed in this paper can take into account the nonlinearity of cumulative damage process as well as the discounting effect of cost. By comparing the present results with the previous other results, the verification is carried out satisfactorily. In addition, it is known from the sensitivity analysis on variables related to the model that the more often preventive maintenance should be implemented, the more crucial the level of importance of system is. However, the tendency is shown in reverse as the interest rate is increased. Meanwhile, the present model has been applied to the armor units of rubble-mound breakwaters. The parameters of damage intensity function have been estimated through the time-dependent prediction of the expected cumulative damage level obtained from the sample path method. In particular, it is confirmed that the shock occurrences can be considered to be a discrete-time stochastic process by investigating the effects of uncertainty of the shock occurrences on the expected cumulative damage level with homogeneous Poisson process and doubly stochastic Poisson process that are the continuous-time stochastic processes. It can be also seen that the stochastic process of cumulative damage would depend directly on the design conditions, thus the preventive maintenance would be varied due to those. Finally, the optimal periods and scale for the preventive maintenance of armor units of rubble-mound breakwaters can be quantitatively determined with the failure limits, the levels of importance of structure, and the interest rates.