• Journal of radiological science and technology
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• v.30 no.2
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• pp.167-175
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• 2007

There are some positive effects by the introduction of PACS(Picture Archiving Communication System). This study is to analyze the mutual relation between before and after of the introduction of PACS in terms of the environment effect. It is supposed to cause the reduction of developing and fixing wastewater according to the increase in the rate of a non-film. This study will also show the amount of wastewater. Target places were the department of image medicine(diagnostic radiation) of the general hospitals in Seoul and Gyeonggi-Do, which are equiped with full PACS. The authors examined questionnaires on the number of projection, the number of indirect projection, the amount of the film used, the number of radiation image CD loan, the amount of the developing and fixing solution used, the change of the amount of fixing wastewater. According to the analysis, we analyzed the change of the amount of developing and fixing solution per a film and the change of the amount of developing and fixing wastewater which is supposed to be reduced proportionally by the introduction of PACS. We got conclusion as below after analyzing 8 hospitals except the largest and the least amount of examination, film used, developing and fixing solution and the amount of developing and fixing wastewater in order to decrease the deviation from 10 general hospitals located in Seoul and Gyeonggi-Do. We compared data one year before adopting PACS Versus 3 years after adopting PACS. 1. The frequences of examination increased to 7,357.7 cases per month but the amount of film used decreased to 90%, from 42,774.4 to 4,181.88 after adopting the PACS. 2. 3 years after adopting PACS, monthly average amount of developing solution used decreased to 92% and the monthly average amount of fixing solution decreased to 86%. 3. Monthly average amount of developing solution used per film increased to 1.49 times and fixing solution increased as much as three times. 4. Monthly average wastewater for developing decreased to 88% and wastewater for fixing decreased up to 87%. 5. Monthly average wastewater for developing per film increased to 3.77 times and wastewater for fixing increased to 3.85 times. Although the amount of film used and the amount of developing and fixing wastewater affected by the reduction of the developing and fixing solution became less on the whole by introduction of PACS, they did not decrease proportionally. Moreover the amount of the developing and fixing solution used and the amount of developing and fixing wastewater per a film increased. That means the expectation for an environmental improvement differs from the actual condition.

• Environmental and Resource Economics Review
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• v.27 no.2
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• pp.233-260
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• 2018

The West Coast is known as one of the world's three largest intertidal mudflats but the mudflat ecosystems have been constantly destroyed by various reclamation projects and industrial complexes. This study intends to estimate the economic values of major ecosystem services provided by the Seocheon intertidal flats using a choice modeling method. The benefits of the intertidal flats are categorized as four different attributes: number of migratory birds (related to biodiversity and cultural services), production of fish and shellfish (regulating services and habitats), tourism activities (cultural services), and number of fishing households in local communities (cultural services). Study results show that the general public enjoys the economic benefits of 1.777 trillion won (900 million won/hectare) as of 2015 in order to preserve 1,200ha of Seocheon mudflat. Assuming that future generations continue to enjoy these economic benefits of mudflat conservation, the annual value converted is about 64.7 billion won/year, corresponding to 53.9 million won/hectare per year. Individuals are willing to pay are expected to maintain their entire life in the 1,000 households living in the Seocheon tidal-flat fishing village, with an average of 11,000 won per person and an additional 50,000 tourist activities per year. It was estimated to have the amount of payment of 9,000 won. An individual's marginal willingness to pay was estimated to be about 11,000 won per year for supporting a total of 1,000 fishing households, 6,000 won to provide tourism activities of 50,000 visitors, and 9,000 won to provide the habitats of 90,000 migratory birds. For segmentation analysis, residents of Seocheon did not place significant values for the attributes besides migratory bird conservation. However, those of Gunsan showed relatively low margtinal willingness to pay for conservation of migratory birds and fishing villages but showed similar preferences for the maintenance of tourism activities compared to the general public. The results imply that the introduction of economic incentive system is needed to effectively manage and conserve ecosystem services of specific intertidal flats.

• Journal of Yeungnam Medical Science
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• v.11 no.2
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• pp.230-239
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• 1994

In Order to evaluate determinants of successful percutaneous transluminal coronary angioplasty (PTCA), PTCA was performed for 172 coronary arterial lesions in 120 patients (89 male, 31 female) at Yeungnam university hospital from Sep. 1992 to Aug. 1993. The corinary artery luminal diameter at the site of the original stenosis was eveluated from end-diastolic frames of identical projections of the preangioplasty and immediate post angioplasty. The coronary luminal and balloon diameters were measured with using of computer measuring system. Overall success rate of 172 attempted lesions was 87.2%. Success rate of female patients was 93.5% and higher than those of male patients. According to the clinical diagnosis, success rate in stable angina was 93.7% and higher than those of post myocardial infarction angina, unstable angina and acute myocardial infarcrion. Success rate of American Heart Association type C lesion was 65.5% and lower those of type A (95.7%), type B (89.5%). There was signfifcantly difference in preangioplasty luminal stenosis, elastic recoil and length of lesion between successful PTCA group and failed PTCA group. Success rate of lesion location at a bend > $45^{\circ}$ and presence of intracoronary thrombus were lower than than those of other angiographic findings. In coclusion, primary angioplasty success was affected by specific angiographic factors. Stenosis severity, thrombus, lesion location at a bend > $45^{\circ}$, elastic recoil, and length of lesion were the principle of determinants of coronary angioplasty success rate.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.2
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• pp.167-174
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• 2015

Purpose : The pre-treatment QA using Portal dosimetry for Volumetric Arc Therapy To analyze whether maintaining the reproducibility depending on various factors. Materials and Methods : Test was used for TrueBeam STx$^{TM}$ (Ver.1.5, Varian, USA). Varian Eclipse Treatment planning system(TPS) was used for planning with total of seven patients include head and neck cancer, lung cancer, prostate cancer, and cervical cancer was established for a Portal dosimetry QA plan. In order to measure these plans, Portal Dosimetry application (Ver.10) (Varian) and Portal Vision aS1000 Imager was used. Each Points of QA was determined by dividing, before and after morning treatment, and the after afternoon treatment ended (after 4 hours). Calibration of EPID(Dark field correction, Flood field correction, Dose normalization) was implemented before Every QA measure points. MLC initialize was implemented after each QA points and QA was retried. Also before QA measurements, Beam Ouput at the each of QA points was measured using the Water Phantom and Ionization chamber(IBA dosimetry, Germany). Results : The mean values of the Gamma pass rate(GPR, 3%, 3mm) for every patients between morning, afternoon and evening was 97.3%, 96.1%, 95.4% and the patient's showing maximum difference was 95.7%, 94.2% 93.7%. The mean value of GPR before and after EPID calibration were 95.94%, 96.01%. The mean value of Beam Output were 100.45%, 100.46%, 100.59% at each QA points. The mean value of GPR before and after MLC initialization were 95.83%, 96.40%. Conclusion : Maintain the reproducibility of the Portal Dosimetry as a VMAT QA tool required management of the various factors that can affect the dosimetry.

• Journal of Radiation Protection and Research
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• v.23 no.4
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• pp.229-236
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• 1998

In order to establish a testing system for personnel dosimetry performance, the radiation fields from photons, beta particles and neutrons are required, in recent, Korea Institute of Nuclear Safety(KINS) established the reference radation fields except neutrons and tested a variety of their properties. As a result of the test, the reference beams were shown to meet satisfactorily not only the standards of the International Organization for Standardization(ISO), but also the standard levels of the developed countries which are intercomparable with the international traceability. This paper describes the reference beam of gamma radiation. The self-designed and established reference radiation fields were investigated and analyzed by ISO and other international standards. The secondary photon contribution and the beam uniformity of the gamma radiation field were measured and evaluated to fulfill those requirements suggested by the ISO-4037. The measured air kerma rate for the $^{137}$Cs and $^{60}$Co gamma fields was 0.1891 $\sim$ 23.4967 $\mu$Gy/s sand 0.5844 $\sim$ 15.9954 $\mu$Gy/s respectively. The uncertainty with 95 % confidence level of the measured air kerma rate was determined to be less than 2.5 % which is comparable to the international reference gamma radiation fields. It was found that the evaluated air kerma calibration factors of Exradin ionization chamber were in good agreement within 0.9 % and 0.03 % with those given by PTB and NIST, respectively. The gamma radiation fields installed at KINS can maintain traceability systems in Korea, Germany and United State.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.2
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• pp.147-155
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• 1987

In order to examine the effect of dietary fish oil on lipid peroxide formation and antiperoxidative efficiency in liver and brain, a group of male and female rats weighing about 70 grams were fed for three months, diet containing mackerel oil(MO) at the level of 10% (w/w). Results were compared, according to sex and source of dietary fat, i.e., in addition to MO, perilla oil(PO), soybean oil(SO), rapeseed oil(RO) or beef tallow(BT). Liver lipid peroxide level was significantly higher and levels of ${\alpha}-tocopherol$ and reduced glutathione(GSH) were lower in MO group than in other groups. This phenomenon was less clear in male than in female. Liver GSH level was lower in male, compared to female, but oxidized glutathione (GSSG) level did not vary, depending on either sex or dietary fat source. Brain lipid peroxide and ${\alpha}-tocopherol$ levels were not different among five experimental groups. Activities of liver and brain glutathione peroxidase and superoxide dismutase were not changed by dietary fat source, but glutathione peroxidase activity was higher in female than in male. The present study shows (a) that there is sex-related difference in antiperoxidatiye activity and (b) that fish oil containing $C_{20-22}({\omega}3)$ fatty acids, increases body lipid peroxide level and consumes more of cellular antioxidant, although it has lower total PUFA content than perilla or soybean oils.

• Journal of Intelligence and Information Systems
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• v.24 no.2
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• pp.243-264
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• 2018

Although the worldwide battery market is recently spurring the development of lithium secondary battery, lead acid batteries (rechargeable batteries) which have good-performance and can be reused are consumed in a wide range of industry fields. However, lead-acid batteries have a serious problem in that deterioration of a battery makes progress quickly in the presence of that degradation of only one cell among several cells which is packed in a battery begins. To overcome this problem, previous researches have attempted to identify the mechanism of deterioration of a battery in many ways. However, most of previous researches have used data obtained in a laboratory to analyze the mechanism of deterioration of a battery but not used data obtained in a real world. The usage of real data can increase the feasibility and the applicability of the findings of a research. Therefore, this study aims to develop a model which predicts the battery deterioration using data obtained in real world. To this end, we collected data which presents change of battery state by attaching sensors enabling to monitor the battery condition in real time to dozens of golf carts operated in the real golf field. As a result, total 16,883 samples were obtained. And then, we developed a model which predicts a precursor phenomenon representing deterioration of a battery by analyzing the data collected from the sensors using machine learning techniques. As initial independent variables, we used 1) inbound time of a cart, 2) outbound time of a cart, 3) duration(from outbound time to charge time), 4) charge amount, 5) used amount, 6) charge efficiency, 7) lowest temperature of battery cell 1 to 6, 8) lowest voltage of battery cell 1 to 6, 9) highest voltage of battery cell 1 to 6, 10) voltage of battery cell 1 to 6 at the beginning of operation, 11) voltage of battery cell 1 to 6 at the end of charge, 12) used amount of battery cell 1 to 6 during operation, 13) used amount of battery during operation(Max-Min), 14) duration of battery use, and 15) highest current during operation. Since the values of the independent variables, lowest temperature of battery cell 1 to 6, lowest voltage of battery cell 1 to 6, highest voltage of battery cell 1 to 6, voltage of battery cell 1 to 6 at the beginning of operation, voltage of battery cell 1 to 6 at the end of charge, and used amount of battery cell 1 to 6 during operation are similar to that of each battery cell, we conducted principal component analysis using verimax orthogonal rotation in order to mitigate the multiple collinearity problem. According to the results, we made new variables by averaging the values of independent variables clustered together, and used them as final independent variables instead of origin variables, thereby reducing the dimension. We used decision tree, logistic regression, Bayesian network as algorithms for building prediction models. And also, we built prediction models using the bagging of each of them, the boosting of each of them, and RandomForest. Experimental results show that the prediction model using the bagging of decision tree yields the best accuracy of 89.3923%. This study has some limitations in that the additional variables which affect the deterioration of battery such as weather (temperature, humidity) and driving habits, did not considered, therefore, we would like to consider the them in the future research. However, the battery deterioration prediction model proposed in the present study is expected to enable effective and efficient management of battery used in the real filed by dramatically and to reduce the cost caused by not detecting battery deterioration accordingly.

• Journal of Intelligence and Information Systems
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• v.24 no.2
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• pp.1-19
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• 2018

Since stock movements forecasting is an important issue both academically and practically, studies related to stock price prediction have been actively conducted. The stock price forecasting research is classified into structured data and unstructured data, and it is divided into technical analysis, fundamental analysis and media effect analysis in detail. In the big data era, research on stock price prediction combining big data is actively underway. Based on a large number of data, stock prediction research mainly focuses on machine learning techniques. Especially, research methods that combine the effects of media are attracting attention recently, among which researches that analyze online news and utilize online news to forecast stock prices are becoming main. Previous studies predicting stock prices through online news are mostly sentiment analysis of news, making different corpus for each company, and making a dictionary that predicts stock prices by recording responses according to the past stock price. Therefore, existing studies have examined the impact of online news on individual companies. For example, stock movements of Samsung Electronics are predicted with only online news of Samsung Electronics. In addition, a method of considering influences among highly relevant companies has also been studied recently. For example, stock movements of Samsung Electronics are predicted with news of Samsung Electronics and a highly related company like LG Electronics.These previous studies examine the effects of news of industrial sector with homogeneity on the individual company. In the previous studies, homogeneous industries are classified according to the Global Industrial Classification Standard. In other words, the existing studies were analyzed under the assumption that industries divided into Global Industrial Classification Standard have homogeneity. However, existing studies have limitations in that they do not take into account influential companies with high relevance or reflect the existence of heterogeneity within the same Global Industrial Classification Standard sectors. As a result of our examining the various sectors, it can be seen that there are sectors that show the industrial sectors are not a homogeneous group. To overcome these limitations of existing studies that do not reflect heterogeneity, our study suggests a methodology that reflects the heterogeneous effects of the industrial sector that affect the stock price by applying k-means clustering. Multiple Kernel Learning is mainly used to integrate data with various characteristics. Multiple Kernel Learning has several kernels, each of which receives and predicts different data. To incorporate effects of target firm and its relevant firms simultaneously, we used Multiple Kernel Learning. Each kernel was assigned to predict stock prices with variables of financial news of the industrial group divided by the target firm, K-means cluster analysis. In order to prove that the suggested methodology is appropriate, experiments were conducted through three years of online news and stock prices. The results of this study are as follows. (1) We confirmed that the information of the industrial sectors related to target company also contains meaningful information to predict stock movements of target company and confirmed that machine learning algorithm has better predictive power when considering the news of the relevant companies and target company's news together. (2) It is important to predict stock movements with varying number of clusters according to the level of homogeneity in the industrial sector. In other words, when stock prices are homogeneous in industrial sectors, it is important to use relational effect at the level of industry group without analyzing clusters or to use it in small number of clusters. When the stock price is heterogeneous in industry group, it is important to cluster them into groups. This study has a contribution that we testified firms classified as Global Industrial Classification Standard have heterogeneity and suggested it is necessary to define the relevance through machine learning and statistical analysis methodology rather than simply defining it in the Global Industrial Classification Standard. It has also contribution that we proved the efficiency of the prediction model reflecting heterogeneity.

• Journal of Korean Public Health Nursing
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• v.6 no.1
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• pp.32-45
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• 1992

An important role of community health nurses in health centers is to solve community health problems found through data collection methodology which has been used to identify the health needs of the community, diagnose the health problems and to plan health programs suitable for the health problems. Also community health nurses must be prepared to know the community health needs and to participate in the planning process. Since 1956 when the health center law was established, community health nurses have really implemented only the services which the government has asked them to do. This has kept them busy enough. But these days as society is in rapid change, community health nurses should have the flexibility to deal with the social change and demands that are unique to their community each which has different health needs and demands. So community health nurses need to identify what community health problems exist in their particular communities. The purposes of this study were as follows. 1) To explore the suitability of the health programs which the government has asked the community health nurses to do for their own communities and if these programs are not suitable, to explore the reasons why. 2) To explore the degree to which the community health nurses have the ability to identify health problems in their own communities and activate the community diagnostic process. 3) To identify the degree that the community health nurses have the ability to implement plans related to community diagnosis. 4) To find out how much data related to community health problems, the community health nurses have and how they are utilizing it. 5) To measure the community health nurses self-confidence concerning diagnostic activities for community health. The study subjects were 454 Community Health Nurses working in Health Centers in Seoul, Korea. The period of data collection was 6 days(Nov. 9th 1991-Nov. 15th 1991). A questionnaire used for data collection was composed of three different items; general characteristics, community health diagnostic activities and self-confidence in performing diagnostic activities. The results of the study are as follows. First, over one third of the respondents replied that the government required activities for their communities are not appropriate. Of these activities the most frequent reply $(51.2\%)$ indicated that many of the activities in the community were inappropriate to the actual situation. Further, $25\%$ of the replies indicated that many activities were only administratively oriented and as such not appropriate. Second, $49.8\%$ of the respondents replied that they had done general assessments and had a general idea of the health problems of their community. Effective solutions to health problems could be found with an increase in health personnel and management ability according to $41.5\%$ of the respondents. Third, to the question as to whether they had ever independently implemented a plan towards solving community diagnosed problems, $52\%$ of nurses replied 'never', $40\%$ 'occasionally' but only $7.5\%$ replied that they did it frequently. Actually there was very little done even in the basic work of collecting the necessary data. Fourth, when asked how much of basic information they had collected that might be used in community diagnosis activity, of 26 items in 5 areas, there was hardly one for which complete data had been collected. Fifteen percent did have data on the geographical aspects of their area, housing distribution and types of housing, while $17.8\%$ knew the frequency with which the health center was used. Concerning community resources, even with a list of community resources, only $12.3\%$ had data on any of these resources, and this data was incomplete. Further, information about social work institutions, and facilities was also incomplete, only $14.2\%$ of the respondents had any data and even it was incomplete; that is, in general, the nurses did not have this information. Fifth, concerning the confidence of the community health nurse in their ability to carry out community diagnoses activities, $60\%$ replied that they were very or at least nominally confident, indicating that although they were not doing community diagnostic activities they felt they could do so, as they were carrying out home visits and program planning as part of their official duties. The following recommendations are made based on the results of this study. First; since the community health nurses have a high perception of the need for community diagnostic activities and. high confidence in their ability to carry out this activity and high percentage of respondents replied that with a little training they could do this even better it is recommended that community diagnostic activity training be included in the continuing education program for community health nurses. Second, in order for the Community Health Nurses to successfully solve the health problems of their respective community they reported to a need to increase the number of health personnel, improve the facilities and the system of managing their work. Considering this, it is recommended that ways be sought to remedy these deficits.

• Journal of Bio-Environment Control
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• v.14 no.1
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• pp.22-28
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• 2005

The use of blankets to preserve heat in oriental melon cultivation is a common practise without artificial heating and warming systems. Efficiency of blanket decreased with annually usage. This experiment was conducted to investigate the effect of double layer nonwoven fabrics on heat conservation, plant growth, fruit quality and yield of oriental melon in greenhouse. The results were compared among the non-woven fabrics of 9+3, 6+6, 6+3 and 12 ounce from transplanting to April 20, 2001, 2002. Night temperature within tunnel was high at 9+3, 6+6, 6+3 and 12 ounce in order. In plant growth, stem length, leaf numbers and exudate, under double layer nonwoven fabrics were better than single layer blanket of 12 ounce especially, 9+3 double layer blanket was the best. Fruit weight, flesh thickness, soluble solid and marketable yield rate remained same in all treatments. Fermented fruit rate was the highest in 12 ounce as $32.9\%,\;19.6\%\;under\;9+3,\;17.1\%\;under\;6+6,\;16.6\%$ under 6+3 double layer nonwoven fabric, respectively. Compared to 2,260kg yield per 10a of 12 ounce single layer nonwoven fabrics, $7\%$ was increased under 9+3 but $3\%\;and\;13\%$ were decreased under 6+6 and 6+3 double layer nonwoven fabrics, respectively. Compared to income, 4,499-thousand-won per 10a, of 12 ounce single layer blanket, $13\%\;and\;3$ were increased under 9+3 and 6+6 double layer nonwoven fabrics, respectively. Whereas, $10\%$ decreased under 6+3 double layer nonwoven fabrics. From this results it is evident that 9+3 double layer nonwoven fabrics was the best for thermokeeping, fruit quality, and was most economic under non heating system.