• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.81-86
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• 2012

Purpose : Combined MR/PET scanners that use the MRI for PET AC face the challenge of absent surface coils in MR images and thus cannot directly account for attenuation in the coils. To make up for the weak point of MR attenuation correction, Three Modality System (PET/CT +MR) were used in Severance hospital. The goal of this work was to investigate the effects of MR Torso Coil on CT attenuation correction for PET. Materials and Methods : PET artifacts were evaluated when the MR Torso Coil was present of CTAC data with changing various kV and mA in uniformity water phantom and 1994 NEMA cylinderical phantom. They evaluated and compared the following two scenarios: (1) The uniform cylinder phantom and the MR Torso Coil scanned and reconstructed using CT-AC; (2) 1994 NEMA cylinderical phantom and the MR Torso Coil scanned and reconstructed using CT-AC. Results : Streak artifacts were present in CT images containing the MR Torso Coil due to metal components. These artifacts persisted after the CT images were converted for PET-AC. CT scans tended to over-estimate the linear attenuation coefficient when the kV and mA is increasing of the metal components when using conventional methods for converting from CT number. Conclusion : The presence of MR coils during PET/CT scanning can cause subtle artifacts and potentially important quantification errors. Alternative CT techniques that mitigate artifacts should be used to improve AC accuracy. When possible, removing segments of an MR coil prior to the PET/CT exam is recommended. Further, MR coils could be redesigned to reduce artifacts by rearranging placement of the most attenuating materials.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.11 no.2
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• pp.179-186
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• 2008

Purpose: Feeding problems are common for typically developing children and have negative effects on physical, behavioral, and cognitive development. The purpose of the current study was to examine factors related to childhood feeding problems for typically developing children via parental reports. Methods: The feeding questionnaire developed by the authors and the Childhood Eating Behavior Inventory (CEBI) were administered to 796 parents of children who recruited from 2 pediatric outpatient clinics (n=379) and community (n=417). Problem eaters (PE) were identified by parental report and frequency analysis was conducted for types of feeding problems and its severity, problem behaviors during mealtime, the feeding methods of the parents, and the need for treatment. Results: The CEBI scores were significantly different between the PE and non-problem eaters (NPE), which suggests that the parental reports were reliable. The younger children had more feeding problems than the older children. The most frequent and severe feeding problems were selective eating and longer mealtimes across all age groups. One-half of the children had more than one problem behaviors during mealtime. Most parents of PE used ineffective methods to deal with children's behaviors during meal time, such as cajoling, which was related to their increased level of stress. Many parents reported their children need professional help for the feeding problems. Conclusion: Feeding problems are prevalent among children, especially younger children. Children with feeding problems showed a number of problem behaviors during mealtime and parental coping methods appeared to be ineffective. The need for treatment was considerable, thus the characteristics of this population must be acknowledged for providing proper treatment and advice.

• Journal of Korean Society of Transportation
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• v.22 no.3 s.74
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• pp.145-157
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• 2004

The cycle length design model of the Korean traffic responsive signal control systems is devised to vary a cycle length as a response to changes in traffic demand in real time by utilizing parameters specified by a system operator and such field information as degrees of saturation of through phases. Since no explicit guideline is provided to a system operator, the system tends to include ambiguity in terms of the system optimization. In addition, the cycle lengths produced by the existing model have yet been verified if they are comparable to the ones minimizing delay. This paper presents the studies conducted (1) to find shortcomings embedded in the existing model by comparing the cycle lengths produced by the model against the ones minimizing delay and (2) to propose a new direction to design a cycle length minimizing delay and excluding such operator oriented parameters. It was found from the study that the cycle lengths from the existing model fail to minimize delay and promote intersection operational conditions to be unsatisfied when traffic volume is low, due to the feature of the changed target operational volume-to-capacity ratio embedded in the model. The 64 different neural network based cycle length design models were developed based on simulation data surrogating field data. The CORSIM optimal cycle lengths minimizing delay were found through the COST software developed for the study. COST searches for the CORSIM optimal cycle length minimizing delay with a heuristic searching method, a hybrid genetic algorithm. Among 64 models, the best one producing cycle lengths close enough to the optimal was selected through statistical tests. It was found from the verification test that the best model designs a cycle length as similar pattern to the ones minimizing delay. The cycle lengths from the proposed model are comparable to the ones from TRANSYT-7F.

• Journal of Korean Home Economics Education Association
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• v.23 no.1
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• pp.159-176
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• 2011

The purpose of this study was to investigate 1) how the middle school Home Economics teachers perceive the importance of the practical problem-focused instruction, 2) how often they perform the instruction, and 3) what they require for the implementation the instruction. Data were collected from 150 Home Economics teachers via e-mail survey and from 6 Home Economics teachers' face-to-face interviews. Descriptive statistics including frequency, percentage, average, and standard deviation, and the results of such analyses as ANOVA, T-test, and correlation were reported using SPSS/win 10.1. The results of this research were as follows: First, even though the majority of the respondents recognized the high need for practical problem-focused instruction, only a small portion of the respondents reported that they performed that instruction in the classroom. There was no correlation between the perception of the need for practical problem-focused instruction and the degree of performance of practical problem-focused instruction. Secondly, the of performance of practical problem-focused instruction was significantly different depending on the years of teaching experience and the subject that the teachers majored in. Job satisfaction had positive correlations with the perception of the need for practical problem-focused instruction and the degree of performance of practical problem-focused instruction. Thirdly, the more teachers shared information and materials with colleagues, the better they tended to be at practical problem-focused instruction. On the other hand, insufficient time for their instruction and a deficiency in understanding the rationale of the instruction were pointed out as barriers to classroom practice. The respondents answered that long-term training programs on the philosophical foundation of practical problem-focused instruction, materials related to the instruction as well as additional credits for Home Economics are most critical to reduce the discrepancy between the teacher perception and the classroom practice of practical problem-focused instruction.

• Knowledge Management Research
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• v.21 no.3
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• pp.249-269
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• 2020

Recently, as the online market has matured, it is facing many problems to prevent the growth. The most common problem is the homogenization of online products, which fails to increase the number of customers any more. Moreover, although the portion of the online market has increased significantly, it now becomes essential to expand offline for further development. In response, many online firms have recently sought to expand their businesses and marketing channels by securing offline spaces that can complement the limitations of online platforms, on top of their existing advantages of online channels. Based on their competitive advantage in terms of analyzing large volumes of customer data utilizing information technologies (e.g., big data and artificial intelligence), they are reinforcing their offline influence as well through this online for offline (O4O) business model. On the other hand, most of the existing research has primarily focused on online to offline (O2O) business model, and there is still a lack of research on O4O business models, which have been actively attempted in various industrial fields in recent years. Since a few of O4O-related studies have been conducted only in an experience marketing setting following a case study method, it is critical to conduct an empirical study on O4O selection attributes and their impact on customer satisfaction and loyalty. Therefore, focusing on China's representative O4O business model, 'Fresh Hema,' this study attempts to identify some key selection attributes specialized for O4O services from the customers' viewpoint and examine the impact of these attributes on customer satisfaction and loyalty. The results of the structural equation modeling (SEM) with 300 O4O (Fresh Hema) experienced customers, reveal that, out of seven O4O selection attributes, four (mobile app quality, mobile payment, product quality, and store facilities) have an impact on customer satisfaction, which also leads to customer loyalty (reuse intention, recommendation intention, and brand attachment). This study would help managers in an O4O area well adapt to rapidly changing customer needs and provide them with some guidelines for enhancing both customer satisfaction and loyalty by allocating more resources to more significant selection attributes, rather than less significant ones.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.8
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• pp.870-876
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• 2005

The multiple regression models which have two factors(population and commercial area) have been used to forecast the water demand in the future. But, the coefficient of population had a negative value because proper regional classification wasn't performed, and it is not reasonable because the population must be a positive factor. So, the regional classification was performed by principal component and cluster analysis to solve the problem. 6 regional characters were transformed into 4 principal components, and the areas were divided into two groups according to cluster analysis which had 4 principal components. The new regression models were made by each group, and the problem was solved. And, the future water demands were estimated by three scenarios(Active, moderate, and passive one). The increase of water demand ore $89.034\;m^3/day$ in active plat $49,077\;m^3/day$ in moderate plan, and $19,996\;m^3/day$ in passive plan. The water supply ability as scenarios is enough in water treatment plant, however, 2 reservoirs among 4 reservoirs don't have enough retention time in all scenarios.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.3
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• pp.319-324
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• 2014

Soybean (Glycine max (L.) Merr.) is an important crop for protein, oil, carbohydrates, isoflavones, and many other nutrients to humans and animals. But, antinutritional factors in the raw mature soybean are exist. Raffinose and stachyose are main antinutritional factors in soybean seed. Both raffinose and stachyose are carbohydrates, belonging to the raffinose family of oligosaccharides (RFOs). RFOs are not readily digested in humans and cause flatulence or diarrhea. The objective of this research is to obtain the information on raffinose and stachyose content according to genotype and environment. A total of twenty two soybean genotypes (11 cultivars, 3 germplasms and 8 breeding lines) were selected. Each genotype was grown in the field for two years with two replications and harvested in bulk at natural maturity for two years. Content of raffinose and stachyose was detected by HPLC. The raffinose content (g/kg) of 22 genotypes was $2.68{\pm}0.21-5.87{\pm}2.43$ in year 1 and was $3.24{\pm}0.37-9.05{\pm}0.16$ in year 2. The stachyose content (g/kg) was $4.23{\pm}0.98-27.68{\pm}9.90$ at year 1 and was $5.11{\pm}1.09-25.32{\pm}0.35$ in year 2. Genotype and environment have highly significant effects on raffinose and stachyose content. Three genotypes (Da-7, 116-13, and RS-78) have low stachyose content at 5% significant level in two years. A positive correlation ($R^2=0.1985^*$) between raffinose and stachyose was observed in year 2. These informations are valuable in soybean genetics and breeding program related with raffinose and stachyose content.

• Cartoon and Animation Studies
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• s.48
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• pp.85-116
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• 2017

The purpose of this study is to analyze conditions that robots depicted in cinematographic works like animations or movies sympathize with and form an attachment with the nuclear person and organize characterizing strategies for emotional sympathetic robots. Along with the development of technology, the areas of artificial intelligence and robots are no longer considered to belong to science fiction but as realistic issues. Therefore, this author assumes that the expressive characteristics of emotional sympathetic robots created by cinematographic works should be used as meaningful factors in expressively embodying human-friendly service robots to be distributed widely afterwards, that is, in establishing the features of characters. To lay the grounds for it, this research has begun. As the subjects of analysis, this researcher has chosen robot characters whose emotional intimacy with the main person is clearly observed among those found in movies and animations produced after the 1920 when robot's contemporary concept was declared. Also, to understand robots' appearance and behavioral tendency, this study (1) has classified robots' external impressions into five types (human-like, cartoon, tool-like, artificial bring, pet or creature) and (2) has classified behavioral tendencies considered to be the outer embodiment of personality by using DiSC, the tool to diagnose behavioral patterns. Meanwhile, it has been observed that robots equipped with high emotional intimacy are all strongly independent about their duties and indicate great emotional acceptance. Therefore, 'influence' and 'Steadiness' types show great emotional acceptance, the influencing type tends to be highly independent, and the 'Conscientiousness' type tends to indicate less emotional acceptance and independency in general. Yet, according to the analysis on external impressions, appearance factors hardly have any significant relationship with emotional sympathy. It implies that regarding the conditions of robots equipped with great emotional sympathy, emotional sympathy grounded on communication exerts more crucial effects than first impression similarly to the process of forming interpersonal relationship in reality. Lastly, to study the characters of robots, it is absolutely needed to have consilient competence embracing different areas widely. This author also has felt that only with design factors or personality factors, it is hard to estimate robot characters and also analyze a vast amount of information demanded in sympathy with humans entirely. However, this researcher will end this thesis as the foundation for it expecting that the general artistic value of animations can be used preciously afterwards in developing robots that have to be studied interdisciplinarily.

• The Journal of Korean Society for Radiation Therapy
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• v.18 no.1
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• pp.1-5
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• 2006

Purpose: IMRT quality assurance(Q.A) is consist of the absolute dosimetry using ionization chamber and relative dosimetry using the film. We have in general used 0.015 cc ionization chamber, because small size and measure the point dose. But this ionization chamber is too small to give an accurate measurement value. In this study, we have examined the degree of calculated to measured dose difference in intensity modulated radiotherapy(IMRT) based on the observed/expected ratio using various kinds of ion chambers, which were used for absolute dosimetry. Materials and Methods: we peformed the 6 cases of IMRT sliding-window method for head and neck cases. Radiation was delivered by using a Clinac 21EX unit(Varian, USA) generating a 6 MV x-ray beam, which is equipped with an integrated multileaf collimator. The dose rate for IMRT treatment is set to 300 MU/min. The ion chamber was located 5cm below the surface of phantom giving 100cm as a source-axis distance(SAD). The various types of ion chambers were used including 0.015cc(pin point type 31014, PTW. Germany), 0.125 cc(micro type 31002, PTW, Germany) and 0.6 cc(famer type 30002, PTW, Germany). The measurement point was carefully chosen to be located at low-gradient area. Results: The experimental results show that the average differences between plan value and measured value are ${\pm}0.91%$ for 0.015 cc pin point chamber, ${\pm}0.52%$ for 0.125 cc micro type chamber and ${\pm}0.76%$ for farmer type 0.6cc chamber. The 0.125 cc micro type chamber is appropriate size for dose measure in IMRT. Conclusion: IMRT Q.A is the important procedure. Based on the various types of ion chamber measurements, we have demonstrated that the dose discrepancy between calculated dose distribution and measured dose distribution for IMRT plans is dependent on the size of ion chambers. The reason is small size ionization chamber have the high signal-to-noise ratio and big size ionization chamber is not located accurate measurement point. Therefore our results suggest the 0.125 cc farmer type chamber is appropriate size for dose measure in IMRT.

• Journal of Hospice and Palliative Care
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• v.19 no.4
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• pp.303-309
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• 2016

Purpose: Malignant ascites is a common complication in terminal cancer patients. Less-invasive pigtail catheter insertion is the most frequent procedure in patients who need repeated ascites drainage. This study investigated effects and adverse events associated with catheter insertion for ascites drainage and evaluated prognostic outcomes. Methods: We reviewed medical records between 2010 and 2013 of hospice and palliative care institutions in Seoul, South Korea. Among 2,608 inpatients, 67 patients received ascites pigtail catheter drainage. We reviewed demographic data, palliative performance scale, laboratory data, duration of catheter insertion, prevalence and type of complications, use and duration of antibiotics, and survival time. Univariate and multivariate Cox regression models were used to evaluate prognostic outcomes related with catheter insertion. Results: Ascites drainage was performed most commonly in hepatobiliary and gastric cancer patients. Ascites symptoms improved in 55 patients after the catheter drainage. Adverse events included pain (19.4%), leakage (14.9%), disconnection (7.5%), catheter occlusion (6%) and fever (4.5%). In Cox regression analysis, survival time from the catheter insertion was significantly associated with Palliative Performance Scale (PPS) (HR 0.73; P value 0.045) and serum sodium level (HR 2.77; P value 0.003) in a multivariate model. Conclusion: Patients' PPS and serum sodium level should be considered before making a decision of pigtail catheter insertion.