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A Review Study on Major Factors Influencing Chlorine Disappearances in Water Storage Tanks (저수조 내 잔류염소 감소에 미치는 주요 영향 인자에 관한 문헌연구)

  • Noh, Yoorae;Kim, Sang-Hyo;Choi, Sung-Uk;Park, Joonhong
    • Journal of Korean Society of Disaster and Security
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    • v.9 no.2
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    • pp.63-75
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    • 2016
  • For safe water supply, residual chlorine has to be maintained in tap-water above a certain level from drinking water treatment plants to the final tap-water end-point. However, according to the current literature, approximately 30-60% of residual chlorine is being lost during the whole water supply pathways. The losses of residual chlorine may have been attributed to the current tendency for water supply managers to reduce chlorine dosage in drinking water treatment plants, aqueous phase decomposition of residual chlorine in supply pipes, accelerated chlorine decomposition at a high temperature during summer, leakage or losses of residual chlorine from old water supply pipes, and disappearances of residual chlorine in water storage tanks. Because of these, it is difficult to rule out the possibility that residual chlorine concentrations become lower than a regulatory level. In addition, it is concerned that the regulatory satisfaction of residual chlorine in water storage tanks can not always be guaranteed by using the current design method in which only storage capacity and/or hydraulic retention time are simply used as design factors, without considering other physico-chemical processes involved in chlorine disappearances in water storage tank. To circumvent the limitations of the current design method, mathematical models for aqueous chlorine decomposition, sorption of chlorine into wall surface, and mass-transfer into air-phase via evaporation were selected from literature, and residual chlorine reduction behavior in water storage tanks was numerically simulated. The model simulation revealed that the major factors influencing residual chlorine disappearances in water storage tanks are the water quality (organic pollutant concentration) of tap-water entering into a storage tank, the hydraulic dispersion developed by inflow of tap-water into a water storage tank, and sorption capacity onto the wall of a water storage tank. The findings from his work provide useful information in developing novel design and technology for minimizing residual chlorine disappearances in water storage tanks.

Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2016 (설비공학 분야의 최근 연구 동향 : 2016년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.29 no.6
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    • pp.327-340
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    • 2017
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2016. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of flow, heat and mass transfer, the reduction of pollutant exhaust gas, cooling and heating, the renewable energy system and the flow around buildings. CFD schemes were used more for all research areas. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results of the long-term performance variation of the plate-type enthalpy exchange element made of paper, design optimization of an extruded-type cooling structure for reducing the weight of LED street lights, and hot plate welding of thermoplastic elastomer packing. In the area of pool boiling and condensing, the heat transfer characteristics of a finned-tube heat exchanger in a PCM (phase change material) thermal energy storage system, influence of flow boiling heat transfer on fouling phenomenon in nanofluids, and PCM at the simultaneous charging and discharging condition were studied. In the area of industrial heat exchangers, one-dimensional flow network model and porous-media model, and R245fa in a plate-shell heat exchanger were studied. (3) Various studies were published in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, subjects include mobile cold storage heat exchanger, compressor reliability, indirect refrigeration system with $CO_2$ as secondary fluid, heat pump for fuel-cell vehicle, heat recovery from hybrid drier and heat exchangers with two-port and flat tubes. In the alternative refrigeration/energy system category, subjects include membrane module for dehumidification refrigeration, desiccant-assisted low-temperature drying, regenerative evaporative cooler and ejector-assisted multi-stage evaporation. In the system control category, subjects include multi-refrigeration system control, emergency cooling of data center and variable-speed compressor control. (4) In building mechanical system research fields, fifteenth studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, renewable energies, etc. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which could be help for improving the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the analyses of indoor thermal environments controlled by portable cooler, the effects of outdoor wind pressure in airflow at high-rise buildings, window air tightness related to the filling piece shapes, stack effect in core type's office building and the development of a movable drawer-type light shelf with adjustable depth of the reflector. The subjects of building energy were worked on the energy consumption analysis in office building, the prediction of exit air temperature of horizontal geothermal heat exchanger, LS-SVM based modeling of hot water supply load for district heating system, the energy saving effect of ERV system using night purge control method and the effect of strengthened insulation level to the building heating and cooling load.

The Relationship among Country of Origin, Brand Equity and Brand Loyalty: Comparison among USA, China and Korea (원산지효과, 상표자산 및 상표충성 간의 관계에 관한 연구: 미국, 중국, 한국의 비교분석)

  • Ko, Eun-Ju;Kim, Kyung-Hoon;Kim, Sook-Hyun;Li, Guo-Feng;Zou, Peng;Zhang, Hao
    • Journal of Global Scholars of Marketing Science
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    • v.19 no.1
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    • pp.47-58
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    • 2009
  • The marketing environment has become competitive to an extent that requires firms to target their products at markets that span national boundaries. However, competitive clout cannot be achieved in global consumer markets unless firms thoroughly understand and adequately respond to the core values and needs of those consumers. Brand equity is one of the most important assets to a company. Especially in sportswear markets, brand equity is the crucial value added to a product by its brand name. Factors such as country of origin also influence customer's attitude towards brand equity. Therefore, this paper discusses the relationship between country of origin effect and brand equity, and how they influence consumers' loyalty for respective brands. This paper focused on the sports shoes market, because it is an increasing area of opportunity for world manufacturers. The objectives of this study were the following. (1) Test the effect of country of origin on brand equity. (2) Test how brand equity influences consumers' brand loyalty. (3) Find whether there are differences in the effects of country of origin and brand equity among the three countries. (4) Find whether there are differences in the effects of country of origin and brand equity among the different lifestyles. Based on the review of literature results, the hypotheses are concluded as the following: H1-a: Country image has positive influence on country of origin. H1-b: Product perception has positive influence on country of origin. H2-a: Perceived quality has positive effect on brand equity. H2-b: Perceived price has positive effect on brand equity. H3: Country of origin has positive effect on brand equity. H4: Brand equity has a positive impact on brand loyalty. Research model was constructed (see Fig. 1). After data analysis, the following results were concluded: sports shoes purchase behavior showed significant differences among Korean, Chinese, and American consumers for favorite brand, purchased brand, purchased place, information usage, and favorite sports games. The results of this study also extend the research of the relationship among country of origin, brand equity and brand loyalty to the sports shoes market. Brand equity was proven to have a significant relationship with brand loyalty for all countries. The factors which can influence brand equity are different for different countries. The third finding of this paper is that we identified different three lifestyles, adventurer, follower, and laggard, for Korean, Chinese and American consumers. Without the nationality boundary, seeing the emergence of a new group of consumers who have similar preferences and buy similar brands is more important. All of the consumers consider brand equity to keep their brand loyalty. Perceived price is the only factor which can influence brand equity for adventurers; brand is more important for them. The laggards were not influenced by any factor. All of the factors expect perceived price are important for the followers. Marketing managers should consider brand equity when introducing their brand into a new market. Also localization is the basic strategy that all the sports shoes companies should understand. But as a global brand, understanding the same characteristics for each country is more important to build global strategy.

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Production of Medium-chain Fatty Acids in Brassica napus by Biotechnology (유채에서의 중쇄지방산 생산)

  • Roh, Kyung-Hee;Lee, Ki-Jong;Park, Jong-Sug;Kim, Hyun-Uk;Lee, Kyeong-Ryeol;Kim, Jong-Bum
    • Journal of Applied Biological Chemistry
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    • v.53 no.2
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    • pp.65-70
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    • 2010
  • Medium-chain fatty acids (MCFA) are composed of 8-12 carbon atoms, and are found in coconut, cuphea, and palm kernel oil. MCFA were introduced into clinical nutrition in the 1950s for dietary treatment of malabsorption syndromes because of their rapid absorption and solubility. Recently, MCFA have been applied to Gastrointestinal Permeation Enhancement Technology (GIPET), which is one of the most important parts in drug delivery system in therapeutics. Therefore, to accumulate the MCFA in seed oil of rapeseed, much effort has been conducted by classical or molecular breeding. Laurate can be successfully accumulated up to 60 mol% in the seed oil of rapeseed by the expression of bay thioesterase (Uc FatB1) alone or crossed with a line over-expressing the coconut lysophosphatidic acid acyltransferase (LPAAT) under the control of a napin seed-storage protein promoter. Also, caprylate and caprate were obtained 7 mol% and 29 mol%, respectively, from plants over-expressing of the medium-chain specific thioesterase (Ch FatB2) alone or together with the chain-length-specific condensing enzyme (Ch KASIV). Despite the success of some research in utilizing parallel classical and molecular breeding to produce MCFA, commercially available seed oils have for the most part, not been realized. Recent research in the field of developing MCFA-enriched transgenic plants has established that there is no single rate-limiting step in the production of the target fatty acids. The purpose of this article is to review some of the recent progress in understanding the mechanism and regulation of MCFA production in seed oil of rapeseed.

A Study on the Precedents Changing Related to International Jurisdiction in Electronic Commerce-Focused on U.S. Cases- (전자상거래의 국제재판관할 관련 판례변화에 관한 연구)

  • Woo, Kwang-Myung
    • International Commerce and Information Review
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    • v.13 no.3
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    • pp.3-29
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    • 2011
  • The Internet has become a medium through which people engage in increasingly sophisticated transactions. Businesses and consumers now use the Internet to communicate and engage in commercial transactions creating a virtual worldwide marketplace. They fear that the determination of Internet jurisdiction could be uncertain because electronic commerce is not executed in one particular place. Until now, there are no specific rules in the model laws and conventions dealing with international jurisdiction in electronic commerce. Due to the fact that U.S. companies are at the forefront of Internet technology, litigation regarding electronic commerce in the U.S. is more advanced than anywhere else in the world This paper analysis the basic framework for personal jurisdiction and approach for determining international jurisdiction in electronic commerce cases and explain the differences of several approaches involving interactions over the Internet. According to jurisdiction approach test, the U.S. employs sliding scale, effects and targeting test in electronic commerce. In recent many research views the targeting test as a global standard for determining international electronic commerce jurisdiction. However, there is still no clear indication of conclusive test of jurisdiction determination for electronic commerce. Therefore, it is a changing and process of jurisdiction test in the U.S. cases. In Korea, there is jurisdiction related clause in Private International Law, but it may be asked whether applicable in electronic commerce. Accordingly, analysis of the precedents changing related to electronic commerce jurisdiction of U.s. is full of suggestions in Korean companies, consumers and helps an enactment of code of civil procedure that containing many group's demands.

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An Approach for Enhancing Current Korean e-Grocery Business Focusing on Delivery Service Alternatives (한국의 e-Grocery 배송서비스 대안에 관한 연구)

  • Koo, Jong-Soon;Lee, Jung-Sun;Jeon, Dong-Hwa
    • International Commerce and Information Review
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    • v.13 no.3
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    • pp.169-201
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    • 2011
  • There was a new wave in grocery business with development of information and technology, thus a movement from traditional stores to online stores, In order to expand the scale of traditional supermarket and to satisfy the customers' needs, they provide offline and online services simultaneously. This paper is based on the previous studies which had been researched in developed countries from late 1990s to early 2000s and the purpose of this study is to introduce the idea and operation system of e-Grocery business. Moreover, we suggest the alternatives on delivery service methods in order to satisfy the customers' needs through analyzing the current condition of e-Grocers in Korea. According to the result of this study, Korean e-Grocers offer only attended home delivery services. In our opinion, Korean supermarkets have to take hybrid model which Tesco.com is using. There are some alternatives to increase the profits of Korean e-Grocers and to provide better services to their customers as follows: As an alternatives for delivery services, picking service is the easiest and cheapest way to apply for supermarkets. This is very useful for working women and also it is possible to order by smartphone recently. They can order the goods to the closest local supermarkets from working place, and then they pick them up on the way home from working off. In order to improve the quality of delivery services, to use the reception box will be the way to provide better services to the customers. The reception box is a way to protect the quality of goods such as fresh-cut product, which require the freshness through the temperature adjustment, and also to keep the safety of ordered goods through locking system Through this system, supermarkets are able to use attended or unattended services under the customers' satisfaction. However, using the reception box is expensive, so shared reception box will be an alternative. As an alternative for development of e-Grocery business, the advertisement for e-Grocery business has to be supported in order to attract potential customers in e-Grocery business. Furthermore, the main concerns of e-Grocery business such as the sanitation and safety of goods, and convenience must be guaranteed in order to keep the loyal customers and to attract new customers.

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A Review of the Neurocognitive Mechanisms for Mathematical Thinking Ability (수학적 사고력에 관한 인지신경학적 연구 개관)

  • Kim, Yon Mi
    • Korean Journal of Cognitive Science
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    • v.27 no.2
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    • pp.159-219
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    • 2016
  • Mathematical ability is important for academic achievement and technological renovations in the STEM disciplines. This study concentrated on the relationship between neural basis of mathematical cognition and its mechanisms. These cognitive functions include domain specific abilities such as numerical skills and visuospatial abilities, as well as domain general abilities which include language, long term memory, and working memory capacity. Individuals can perform higher cognitive functions such as abstract thinking and reasoning based on these basic cognitive functions. The next topic covered in this study is about individual differences in mathematical abilities. Neural efficiency theory was incorporated in this study to view mathematical talent. According to the theory, a person with mathematical talent uses his or her brain more efficiently than the effortful endeavour of the average human being. Mathematically gifted students show different brain activities when compared to average students. Interhemispheric and intrahemispheric connectivities are enhanced in those students, particularly in the right brain along fronto-parietal longitudinal fasciculus. The third topic deals with growth and development in mathematical capacity. As individuals mature, practice mathematical skills, and gain knowledge, such changes are reflected in cortical activation, which include changes in the activation level, redistribution, and reorganization in the supporting cortex. Among these, reorganization can be related to neural plasticity. Neural plasticity was observed in professional mathematicians and children with mathematical learning disabilities. Last topic is about mathematical creativity viewed from Neural Darwinism. When the brain is faced with a novel problem, it needs to collect all of the necessary concepts(knowledge) from long term memory, make multitudes of connections, and test which ones have the highest probability in helping solve the unusual problem. Having followed the above brain modifying steps, once the brain finally finds the correct response to the novel problem, the final response comes as a form of inspiration. For a novice, the first step of acquisition of knowledge structure is the most important. However, as expertise increases, the latter two stages of making connections and selection become more important.

A Study on the Relationship between Adiponectin, BDNF and Leptin with Abdominal Fat Thickness in Male Workers (남성 근로자의 복부지방두께와 adiponectin, BDNF 및 leptin의 관련성)

  • Ko, Kyung-Sun;Choi, Yoon-Jung
    • Journal of radiological science and technology
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    • v.36 no.3
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    • pp.209-217
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    • 2013
  • Adiponectin (AdipoN), brain-derived nerotrophic factor (BDNF) and leptin (LeP) are mainly secreted from adipose tissue and are known to be involved in regulation of the development of obese. However, there are not many studies on the association between abdominal fat and neuropeptides such as AdipoN, BDNF and LeP. The aim of this study was undertaken to investigate the association between abdominal fat thickness, neuropeptides and cardiovascular disease (CVD) risk factors. The participants in the study were 138 male employees without CVD. This study was approved by the Institutional Review Board of Occupational Safety and Health Research Institute. Written informed consent for the participants in this study was obtained from all individuals. We obtained subcutaneous fat thickness (SFT) and visceral fat thickness (VFT) by using ultrasonography and neuropeptides levels were measured with ELISA kit according to the method suggested by kit manufacturer. The mean SFT and VFT were $1.58{\pm}0.51$ and $4.52{\pm}1.44$ cm. The mean concentrations of AdipoN, BDNF and LeP were $3.14{\pm}3.52$ ng/ml, $24.11{\pm}8.52$ pg/ml and $4.27{\pm}2.38$ ng/ml, respectively. VFT were positively correlated with total cholesterol (r=0.217, p<0.05), LDL-cholesterol (r=0.271, p<0.01), triglyceride (r=0.233, p<0.05) and insulin (r=0.338, p<0.01), but was inversely correlated with HDL-cholesterol (r=-420, p<0.01). AdipoN levels were positively correlated with HDL-cholesterol (r=0.220, p<0.05) and were inversely correlated with total cholesterol (r=-0.196, p<0.05), LDL-cholesterol (r=-0.190, p<0.05), triglyceride (r=-0.199, p<0.05), SFT (r=-0.195, p<0.05) and VFT (r=-0.412, p<0.01). However, LeP levels showed a reverse trend to AdipoN. AdipoN level was significantly higher in non-obese participants (BMI<25 kg/m), but LeP concentration was significantly higher in obese participants (BMI>25 kg/m) than in non-obese. On multiple logistic regression analysis, obese were significantly associated with AdipoN (odds ratio=0.784) and LeP (odds ratio=1.494). These results suggested that AdipoN and LeP concentrations are affected abdominal fat and that dysfunction and/or declination in the production and secretion of neuropeptides might induced ultimately obese and CVD.

Review: Distribution, Lactose Malabsorption, and Alleviation Strategies of Lactose Intolerance (유당불내증(Lactose Intolerance)의 발생 원인과 경감 방안에 대한 고찰)

  • Yoon, Sung-Sik
    • Journal of Dairy Science and Biotechnology
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    • v.27 no.2
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    • pp.55-62
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    • 2009
  • Milk is called an almost complete food in terms of nutrition, especially for the younger generations because it contains a number of nutrients required for growth and development. Lactose intolerance is defined as a malabsorption of lactose in the intestine with some typical symptoms of abdominal pains and bloating, and occurred at 75% of global populations, which hampers milk consumption worldwide. Lacks of milk consumption in the underdeveloped countries frequently lead to many nutrients deficiencies, so that diseases including osteoporosis, hypertension, and colon cancer are more prevalent in the recent days. Lactose in foods needs to be hydrolyzed prior to intestinal absorption. The hydrolytic enzyme responsible for splitting lactose into its monomeric forms, glucose and galactose, is called as lactase or $\beta$-galactosidase. The former is primarily used as blood sugar and energy source and the latter used in glycolipid synthesis of brain tissues in infants. Lactose is clinically diagnosed with the breath hydrogen production test as well as intestinal biopsy. Reportedly, symptoms of lactose intolerance are widely prevalent at 25% of Europeans, 50 to 80% of Hispanics, South Indians, Africans, and Jews, almost 100% of Asians and native Americans. For the adults, phenotype of lactase persistence, which is able to hydrolyse lactose, is more common in the northern Europeans, but in the other area lactase non-persistence or adult-type hypolactasia is dominant. Genetic analysis on human lactase gene continued that lactase persistence was closely related to the err site of 1390 single nucleotide polymorphism from the 5'-end. To alleviate severity of lactose intolerance symptoms, some eating patterns including drinking milk a single cup or less, consumption along with other foods, whole milk rather than skimmed milk, and drink with live yogurt cultures, are highly recommended for the lactose maldigesters. Also, delay of gastric emptying is effective to avoid the symptoms from lactose intolerance. Frequency of lactose intolerance with conventional diagnosis is thought overestimated mainly because the subjects are exposed to too much lactose of 50 g rather than a single serving amount. Thus simple and accurate diagnostic method for lactose intolerance need to be established. It is thought that fermented milk products and low- or free lactose milks help improve currently stagnant milk consumption due to lactose intolerance which contributes to major barrier in milk marketing especially in Asian countries.

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Review on Usefulness of EPID (Electronic Portal Imaging Device) (EPID (Electronic Portal Imaging Device)의 유용성에 관한 고찰)

  • Lee, Choong Won;Park, Do Keun;Choi, A Hyun;Ahn, Jong Ho;Song, Ki Weon
    • The Journal of Korean Society for Radiation Therapy
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    • v.25 no.1
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    • pp.57-67
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    • 2013
  • Purpose: Replacing the film which used to be used for checking the set-up of the patient and dosimetry during radiation therapy, more and more EPID equipped devices are in use at present. Accordingly, this article tried to evaluated the accuracy of the position check-up and the usefulness of dosimetry during the use of an electronic portal imaging device. Materials and Methods: On 50 materials acquired with the search of Korea Society Radiotherapeutic Technology, The Korean Society for Radiation Oncology, and Pubmed using "EPID", "Portal dosimetry", "Portal image", "Dose verification", "Quality control", "Cine mode", "Quality - assurance", and "In vivo dosimetry" as indexes, the usefulness of EPID was analyzed by classifying them as history of EPID and dosimetry, set-up verification and characteristics of EPID. Results: EPID is developed from the first generation of Liquid-filled ionization chamber, through the second generation of Camera-based fluoroscopy, and to the third generation of Amorphous-silicon EPID imaging modes can be divided into EPID mode, Cine mode and Integrated mode. When evaluating absolute dose accuracy of films and EPID, it was found that EPID showed within 1% and EDR2 film showed within 3% errors. It was confirmed that EPID is better in error measurement accuracy than film. When gamma analyzing the dose distribution of the base exposure plane which was calculated from therapy planning system, and planes calculated by EDR2 film and EPID, both film and EPID showed less than 2% of pixels which exceeded 1 at gamma values (r%>1) with in the thresholds such as 3%/3 mm and 2%/2 mm respectively. For the time needed for full course QA in IMRT to compare loads, EDR2 film recorded approximately 110 minutes, and EPID recorded approximately 55 minutes. Conclusion: EPID could easily replace conventional complicated and troublesome film and ionization chamber which used to be used for dosimetry and set-up verification, and it was proved to be very efficient and accurate dosimetry device in quality assurance of IMRT (intensity modulated radiation therapy). As cine mode imaging using EPID allows locating tumors in real-time without additional dose in lung and liver which are mobile according to movements of diaphragm and in rectal cancer patients who have unstable position, it may help to implement the most optimal radiotherapy for patients.

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