• Korean Journal of Radiology
• /
• v.23 no.5
• /
• pp.539-547
• /
• 2022

Objective: To investigate the association between functional tumor burden of peritoneal carcinomatosis (PC) derived from diffusion-weighted imaging (DWI) and overall survival in patients with advanced ovarian carcinoma (OC). Materials and Methods: This prospective study was approved by the local research ethics committee, and informed consent was obtained. Fifty patients (mean age ± standard deviation, 57 ± 12 years) with stage III-IV OC scheduled for primary or interval debulking surgery (IDS) were recruited between June 2016 and December 2021. DWI (b values: 0, 400, and 800 s/mm²) was acquired with a 16-channel phased-array torso coil. The functional PC burden on DWI was derived based on K-means clustering to discard fat, air, and normal tissue. A score similar to the surgical peritoneal cancer index was assigned to each abdominopelvic region, with additional scores assigned to the involvement of critical sites, denoted as the functional peritoneal cancer index (fPCI). The apparent diffusion coefficient (ADC) of the largest lesion was calculated. Patients were dichotomized by immediate surgical outcome into high- and low-risk groups (with and without residual disease, respectively) with subsequent survival analysis using the Kaplan-Meier curve and log-rank test. Multivariable Cox proportional hazards regression was used to evaluate the association between DWI-derived results and overall survival. Results: Fifteen (30.0%) patients underwent primary debulking surgery, and 35 (70.0%) patients received neoadjuvant chemotherapy followed by IDS. Complete tumor debulking was achieved in 32 patients. Patients with residual disease after debulking surgery had reduced overall survival (p = 0.043). The fPCI/ADC was negatively associated with overall survival when accounted for clinicopathological information with a hazard ratio of 1.254 for high fPCI/ADC (95% confidence interval, 1.007-1.560; p = 0.043). Conclusion: A high DWI-derived functional tumor burden was associated with decreased overall survival in patients with advanced OC.

• Journal of dental hygiene science
• /
• v.17 no.2
• /
• pp.123-133
• /
• 2017

The aim of this study was to analyze in depth the standardized Clinical dental hygiene curriculum of the Fones School in the United States. We investigated the clinical dental hygiene curriculum in 2015~2016 including title, credit, hours, contents, goals, competencies, and evaluation. We obtained the course syllabus and data related to each subject, for each grade, from the professors and students at the university. The goals and competencies, of the clinical dental hygiene program, which were based on the goals of the Fones School and the mission of the University of Bridgeport, were developed in accordance with the dental hygienist practice standards proposed by the American Dental Hygienists Association. The curriculum consisted of theory to teach proper dental hygiene care procedures and incorporated practical exercises that modeled an actual clinical setting. The students had to document the procedures performed for each client/patient and improve their clinical competency through discussion with the professors. Dental hygiene care should be provided for children, adolescents, adults, elderly, and patients, which includes patients with moderate or severe periodontal status. Students were evaluated by a paper test or case study presentation and their clinical evaluation was based on their clinical competency. In particular, professors evaluated students on a rotational basis, so they could evaluate the level of achievement of clinical competency of all students and find ways to improve any weaknesses. Therefore, the current study suggested that clinical dental hygiene program in Korea could be improved if based on the curriculum of Fones School in the United States.

• Journal of the Korean Institute of Gas
• /
• v.8 no.2 s.23
• /
• pp.15-27
• /
• 2004

The purpose of this paper is to improve the performance of Polymer electrolyte fuel cell(PEMFC) by studying the channel dimension of bipolar plates using commercial CFD program 'Fluent'. Simulations are done ranging from 0.5 to 3.0mm for different size in order to find the channel size which shoves the highst hydrogen consumption. The results showed that the smaller channel width, land width, channel depth, the higher hydrogen consumption in anode. When channel width is increased, the pressure drop in channel is decreased because total channel length Is decreased, and when land width is increased, the net hydrogen consumption is decreased because hydrogen is diffused under the land width. It is also found that the influence of hydrogen consumption is larger at different channel width than it at different land width. The change of hydrogen consumption with different channel depth isn't as large as it with different channel width, but channel depth has to be small as can as it does because it has influence on the volume of bipolar plates. however the hydrogen utilization among the channel sizes more than 1.0mm which can be machined in reality is the most at channel width 1.0, land width 1.0, channel depth 0.5mm and considered as optimum channel size. The fuel cell combined with 2cm${\times}$2cm diagonal or serpentine type flow field and MEA(Membrane Electrode Assembly) is tested using 100W PEMFC test station to confirm that the channel size studied in simulation. The results showed that diagonal and serpentine flow field have similarly high OCV and current density of diagonal (low field is higher($2-40mA/m^2$) than that of serpentine flow field under 0.6 voltage, but the current density of serpentine type has higher performance($5-10mA/m^2$) than that of diagonal flow field under 0.7-0.8 voltage.

• Journal of dental hygiene science
• /
• v.17 no.6
• /
• pp.523-532
• /
• 2017

The purpose of this study was to provide basic data to standardize the clinical dental hygiene curriculum, based on analysis of current clinical dental hygiene curricula in Korea. We emailed questionnaires to 12 schools to investigate clinical dental hygiene curricula, from February to March, 2017. We analyzed the clinical dental hygiene curricula in 5 schools with a 3-year program and in 7 schools with a 4-year program. The questionnaire comprised nine items on topics relating to clinical dental hygiene, and four items relating to the dental hygiene process and oral prophylaxis. The questionnaire included details regarding the subject name, the grade/semester/credit system, course content and class hours, the number of senior professors, and the number of patients available for dental hygiene clinical training purposes. In total, there were 96 topics listed in the curricula relating to clinical dental hygiene training, and topics varied between the schools. There was an average of 20.4 topic credits, and more credits and hours were allocated to the 4-year program than to the 3-year program. On average, the ratio of students to professors was 21.4:1. Course content included infection control, concepts for dental hygiene processes, dental hygiene assessment, intervention and evaluation, case studies, and periodontal instrumentation. An average of 2 hours per patient was spent on dental hygiene practice, with an average of 1.9 visits. On average, student clinical training involved 19 patients and 26.6 patients in the 3-year and 4-year programs, respectively. The average participation time per student per topic was 38.0 hours and 53.1 hours, in the 3-year and 4-year programs, respectively. Standardizing the clinical dental hygiene curricula in Korea will require consensus guidelines on topics, the number of classes required to achieve core competencies as a dental hygienist, and theory and practice time.

• International Journal of Computer Science & Network Security
• /
• v.21 no.12spc
• /
• pp.664-674
• /
• 2021

The relevance of this scientific research is determined by the negative impact of the COVID-19 pandemic on the current trends and dynamics of world tourism development. This article aims to identify patterns of development of the modern tourist market, analysis of problems and prospects of development in the context of the COVID-19 pandemic. Materials and methods. General scientific methods and methods of research are used in the work: analysis, synthesis, comparison, analysis of statistical data. The analysis of the viewpoints of foreign and domestic authors on the research of the international tourist market allowed us to substantiate the actual directions of tourism development due to the influence of negative factors connected with the spread of a new coronavirus infection COVID-19. Economic-statistical, abstract-logical, and economic-mathematical methods of research were used during the process of study and data processing. Results. The analysis of the current state of the tourist market by world regions was carried out. It was found that tourism is one of the most affected sectors from COVID-19, as, by the end of 2020, the total number of tourist arrivals in the world decreased by 74% compared to the same period in 2019. The consequence of this decline was a loss of total global tourism revenues by the end of 2020, which equaled $1.3 trillion. 27% of all destinations are completely closed to international tourism. At the end of 2020, the economy of international tourism has shrunk by about 80%. In 2020 the world traveled 98 million fewer people (-83%) relative to the same period last year. Tourism was hit hardest by the pandemic in the Asia-Pacific region, where travel restrictions are as strict as possible. International arrivals in this region fell by 84% (300 million). The Middle East and Africa recorded declines of 75 and 70 percent. Despite a small and short-lived recovery in the summer of 2020, Europe lost 71% of the tourist flow, with the European continent recording the largest drop in absolute terms compared with 2019, 500 million. In North and South America, foreign arrivals declined. It is revealed that a significant decrease in tourist flows leads to a massive loss of jobs, a sharp decline in foreign exchange earnings and taxes, which limits the ability of states to support the tourism industry. Three possible scenarios of exit of the tourist industry from the crisis, reflecting the most probable changes of monthly tourist flows, are considered. The characteristics of respondents from Ukraine, Germany, and the USA and their attitude to travel depending on gender, age, education level, professional status, and monthly income are presented. About 57% of respondents from Ukraine, Poland, and the United States were planning a tourist trip in 2021. Note that people with higher or secondary education were more willing to plan such a trip. The results of the empirical study confirm that interest in domestic tourism has increased significantly in 2021. The regression model of dependence of the number of domestic tourist trips on the example of Ukraine with time tendency (t) and seasonal variations (Turˆt = 7288,498 - 20,58t - 410,88∑5) it forecast for 2020, which allows stabilizing the process of tourist trips after the pandemic to use this model to forecast for any country. Discussion. We should emphasize the seriousness of the COVID-19 pandemic and the fact that many experts and scientists believe in the long-term recovery of the tourism industry. In our opinion, the governments of the countries need to refocus on domestic tourism and deal with infrastructure development, search for new niches, formats, formation of new package deals in new - domestic - segment (new products' development (tourist routes, exhibitions, sightseeing programs, special rehabilitation programs after COVID) -19 in sanatoriums, etc.); creation of individual offers for different target audiences). Conclusions. Thus, the identified trends are associated with a decrease in the number of tourist flows, the negative impact of the pandemic on employment and income from tourism activities. International tourism needs two to four years before it returns to the level of 2019.

• Korea Journal of Hospital Management
• /
• v.19 no.3
• /
• pp.11-28
• /
• 2014

This study, targeting Korean tertiary hospitals and general hospitals, aims to analyze how value chain model in health and medical institution suggested by Duncan and else influences on hospital management. A survey was conducted to verify the actual proof analysis of this study model. 880 questionnaires were distributed to entire 88 hospitals and 739 copies were returned from 76 hospitals. This study mainly consists of three steps to analyze the effect value chain activity has on management performance of general hospitals. For the first step, we analyzed the effects service delivery activity has on management performance. For the second step, we analyzed the effects service support activity has on management performance and for the third, we analyzed the effects interaction between service delivery activity and service support activity has on management performance. The main results of this study are as follows. First, in terms of the management performance of scale, the factors which influenced on daily charge of outpatient were service activity before treatment, at the moment of treatment and value chain activity, while more important factors in daily charge of inpatient were organizational culture, organizational structure and value chain activity. In terms of management performance of quality, the factors which influenced on the first medical examination rate of outpatient were service activity before, at the moment of and after treatment, while activity at the moment of treatment, organizational structure, and value chain activity which is interaction were more important factors in average length of stay. In terms of non-financial performance, the management performance factors which influenced on job satisfaction were service activity at the moment of, after the treatment and value chain activity, while organizational culture, strategy resources and value chain activity which is interaction were more important factors in job commitment. Secondly, all the service support activity, service delivery activity and value chain activity had statistically significant effect on management performance. Among the three factors, service support activity had relatively high effect than others.

• Science of Emotion and Sensibility
• /
• v.11 no.4
• /
• pp.511-520
• /
• 2008

The fundamental goal of this study is to analyze characteristics of combined relations of formative element factors that compose robot's face based on a result of preference response from robot's design. Also, in order to improve preference from the analysis result, this study intended to inquire into possibilities of suggesting design guideline. For these, pictures of 27 different kinds of robot faces were selected as experimental stimuli, and experiments of preference response and association response were performed. As a result of the experiments, various characteristics were achieved such as robot's eye shape having greater influences than facial structure, etc. Based on the result, formative element factor characteristics that could positively influence preference response on robot's face could be drawn and a basic design guideline could also be suggested. An eye should be oval so that the length-to-width ratio may be 1.67:1. The distance between both eyes should be 35% of the facial width. Also, eyes should be above the central latitude of the face so that they may be visually stable. It is advisable to round the face generally. Eyes should be harmonious with the face so that the robot may seem cute and charming.

• Journal of the Korean Chemical Society
• /
• v.55 no.3
• /
• pp.478-485
• /
• 2011

Merocyanine derivatives transformed from spiropyran-containing compounds by irradiating the light of ultraviolet (UV) include zwitterion of phenolate anion and amine cation. Complexation of this phenolate anion on merocyaninemodified surface and Ni ion among metal ions led to a change of surface charge and it was measured with kelvin prove force microscopy (KFM). We found that the resultant surface potential decreased linearly as UV-exposed time increased, and finally were saturated. Also it was analyzed through XPS the immobilized amount of Ni ions was increased according to increase of UV-exposed time. It is considered that these properties could be applied for detection and a quantitative control of different metal ions. Further research is to aim construct specific scaffold/matrix which enable high selective, high sensitive and, especially, a quantitative immobilization of metal ions-binding biomaterials such as proteins and cells.

• Korean Journal of Materials Research
• /
• v.19 no.2
• /
• pp.61-67
• /
• 2009

Electrolessly deposited Co (Re,P) was investigated as a possible capping layer for Cu wires. 50 nm Co (Re,P) films were deposited on Cu/Ti-coated silicon wafers which acted as a catalytic seed and an adhesion layer, respectively. To obtain the optimized bath composition, electroless deposition was studied through an electrochemical approach via a linear sweep voltammetry analysis. The results of using this method showed that the best deposition conditions were a $CoSO_4$ concentration of 0.082 mol/l, a solution pH of 9, a $KReO_4$ concentration of 0.0003 mol/l and sodium hypophosphite concentration of 0.1 mol/L at $80^{\circ}C$. The thermal stability of the Co (Re,P) layer as a barrier preventing Cu was evaluated using Auger electron spectroscopy and a Scanning calorimeter. The measurement results showed that Re impurities stabilized the h.c.p. phase up to $550^{\circ}C$ and that the Co (Re,P) film efficiently blocked Cu diffusion under an annealing temperature of $400^{\circ}C$ for 1hr. The good barrier properties that were observed can be explained by the nano-sized grains along with the blocking effect of the impurities at the fast diffusion path of the grain boundaries. The transformation temperature from the amorphous to crystal structure is increased by doping the Re.

• Journal of Korean society of Dental Hygiene
• /
• v.20 no.1
• /
• pp.107-116
• /
• 2020

Objectives: This study applied the co-orientation model to investigate the degree to which dental hygienists and dentists recognize the efficiency of dental hygienists' non-surgical periodontal therapy work; the basic data can be provided as a systematic arrangement that can be applied and extended to dental clinics to raise mutual understanding. Methods: Independent sample t-tests, one-way ANOVA, and paired t-tests were conducted with a total of 888 subjects (530 dental hygienists and 358 dentists) using SPSS Statistics 22.0. Results: The analysis showed that, dental hygienists had higher recognition of the efficiency of their work (p<0.001) than dentists, with respect to all items(p>0.05). With respect to subjective agreement, dental hygienists estimated lower recognition among dentists than other dental hygienists and dentists estimated higher recognition among dentists than dental hygienists. With respect to accuracy, dentists' estimation was lower than the actual recognition among dental hygienists and dental hygienists' estimation was higher than the actual recognition among dentists in all cases except the efficiency of dental hygienists' patient education work and constant learning. Conclusions: There was wide gap between dental hygienists and dentists in recognition of the efficiency of dental hygienists' non-surgical periodontal therapy work. Actions must be taken to raise mutual understanding between dental hygienists and dentists regarding dental hygienists' non-surgical periodontal therapy work, to spread this recognition throughout the dental industry, and to implement systematic support at dental clinics.