• Journal of Technology Innovation
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• v.24 no.4
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• pp.1-26
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• 2016

The period after the PhD has a huge impact on the careers of researcher from a researcher lifecycle perspective. This is a turning point which student receives guidance from professor and become an independent researcher. Furthermore, they learn to develop ideas for independent research, apply for grants and manage a project; they also form expert networks in related filed and publish papers to share their findings. This study focuses on the period between earning doctoral degree and being employed as a stable position in university. This study starts from a research questions that asks which factors of postdoctoral experience affect research output. In this study, the paper performance, especially co-authorship of paper, of postdoctoral researchers was investigated. The cumulative advantage theory and Matthew effect were employed to shed a light on this research question. The empirical work is based on the Survey & Analysis of National R&D program in Korea conducted by Korea Institute of S&T Evaluation and Planning (KISTEP). The correlations between the research output and characteristics of postdoctoral experience were verified. These results are expected to contribute as new empirical evidences on investigating knowledge transfer activities of new PhDs.

• Journal of Korean Neurosurgical Society
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• v.63 no.5
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• pp.590-597
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• 2020

Objective : Covered stenting is an optional strategy for traumatic carotid pseudoaneurysm, especially in malignant conditions of potential rupture, but the long-term outcomes are not clear. Our aim was to determine if covered stenting is an effective option for traumatic carotid pseudoaneurysm with promising long-term outcomes. Methods : Self-expanding Viabahn and balloon-expandable Willis covered stents were separately implanted for extra- and intracranial traumatic carotid pseudoaneurysm. The covered stent was placed across the distal and proximal pseudoaneurysm leakage under roadmap guidance. Procedural success was defined as technical success (complete exclusion of the pseudoaneurysm and patency of the parent artery) without a primary end point (any stroke or death within 30 days after the procedure). Long-term outcomes were evaluated as ischemic stroke in the territory of the qualifying artery by clinical follow-up through outpatient or telephone consultation and as the exclusion of the pseudoaneurysm and patency of the parent artery by imaging follow-up through angiography. Results : Five patients with traumatic carotid pseudoaneurysm who underwent covered stenting were enrolled. The procedural success rate was 100%. No ischemic stroke in the territory of the qualifying artery was recorded in any of the five patients during a mean clinical follow-up of 44±16 months. Complete exclusion of the pseudoaneurysm and patency of the parent artery were maintained in all five patients during a mean imaging follow-up of 39±16 months. Conclusion : Satisfactory procedural and long-term outcomes were obtained, suggesting that covered stenting is an effective option for traumatic carotid pseudoaneurysm.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.1
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• pp.79-86
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• 2015

Purpose : The purpose of this study was to determine the proper treatment time of stereotactic body radiation therapy for spine metastasis cancer by using the image guidance system of CyberKnife(Accuray Incorporated, USA) which is able to correct movements of patients during the treatment. Materials and Methods : Fifty seven spine metastasis cancer patients who have stereotactic body radiation therapy of CyberKnife participate, 8 of them with cervical spine cancer, 26 of them with thoracic spine cancer, and 23 of them with lumbar spine cancer. X-ray images acquired during the treatment were classified by treatment site. From the starting point of treatment, motion tendency of patients is analyzed in each section which is divided into every 5 minutes. Results : In case of cervical spine, there is sudden increase of variation in 15 minutes after the treatment starts in rotational direction. In case of thoracic spine, there is no significantly variable section. However, variation increases gradually with the passage of time so that it is assumed that noticeable value comes up in approximately 40 minutes. In case of lumbar spine, sharp increase of variation is seen in 20 minutes in translational and rotational direction. Conclusion : Without having corrections during the treatment, proper treatment time is considered as less than 15 minutes for cervical spine, 40 minutes for thoracic spine, and 20 minutes for lumbar spine. If treatment time is longer than these duration, additional patient alignments are required or PTV margin should be enlarged.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.501-506
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• 2015

Background: To evaluate the effectiveness of the National Train-the-Trainers Program for Hospice and Palliative Care Experts (TTHPC) sponsored by the National Cancer Center of Korea between 2009 and 2012. This program was developed to improve the teaching skills of those in the field of hospice and palliative care (HPC). Materials and Methods: Training was offered in eight 1-day sessions between 2009 and 2012. The effect of the program was measured using Kirkpatrick's model of educational outcomes. First, levels 1 and 2 were evaluated immediately after the 1-day program (n=120). In 2012, the level-3 evaluation test was administered to trainers who offered at least one HPC training (n=78) as well as to their trainees (n=537). Results: The level-1 evaluation addressed participant reactions to and satisfaction with the program. Participants (n=120) were generally satisfied with the content, the method, and the overall course (mean range: 3.94-4.46 on a five-point Likert scale). The level-2 evaluation (learning) showed that participants gained knowledge and confidence related to teaching HPC (4.24 vs. 4.00). The level-3 evaluation (behavioral), which assessed trainers' application of teaching skills to HPC, showed that trainees rated the teaching methods of trainers (mean range: 4.03-4.08) more positively than did trainers (p<0.05). Female trainers were more likely than were male trainers to plan sessions in consideration of their trainees' characteristics (4.11 vs. 3.58; p<0.05), and nurse trainers were more likely than physician trainers to use a variety of instructional methods (4.05 vs. 3.36; p<0.05) Conclusions: We conducted systematic evaluations based on Kirkpatrick's model to assess the effectiveness of our train-the-trainers program. Our educational program was practical, effective, and followed by our HPC experts, who needed guidance to learn and improve their clinical teaching skills.

• The Journal of the Korea Contents Association
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• v.14 no.10
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• pp.754-775
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• 2014

At the point of growth management, weighted values for the each index have been calculated by applying AHP method based on the interview. With calculated weighted values, an example assessment had been performed on Gyunggi area, a typical place where urban growth management is needed urgently, and intended to provide applicable implications by analyzing them when establishing the means of the urban growth management plans. The result of this research is presented in order of the weight values highest to lowest as below: 'preventing disordered urban sprawl', 'protecting taxpayers', 'promoting efficient urban development' and 'improving the quality of life'. When applied to Gyunggi area, the results are in similar patterns: 'preventing disordered urban sprawl (11 cities)', 'protecting taxpayers (11 cities)', 'improving the quality of life (5 cities)' and 'promoting efficient urban development (4 cities)'. To build the well-balanced urban growth management plans, two factors must be in consideration as well as with others, 'Improving quality of the life' and 'promoting efficient urban development'. Furthermore, the result of the index in this research can provide a guidance to local governments of provinces and cities to build their urban growth management plans in the future.

• Toxicological Research
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• v.26 no.4
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• pp.285-291
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• 2010

Recently, reproductive and neurobehavioral effects of bisphenol A (BPA) have been documented, and thus a review was requested for BPA management direction by the government. Therefore, this study was performed to establish a Korean tolerable daily intake (TDI) for BPA. An expert committee, consisting of specialists in fields such as toxicology, medicine, pharmacology, and statistics, was asked to evaluate BPA health based guidance values (HbGVs). Although many toxicological studies were reviewed to select a point of departure (POD) for TDI, rat and mouse reproductive studies by Tyl et al. (2002, 2006), which were performed according to GLP standards and OECD guidelines, were selected. This POD was the lowest value determined from the most sensitive toxicological test. The POD, a NOAEL of 5 mg/kg bw/day, was selected based on its systemic toxicity as critical effects. An uncertainty factor of 100 including interspecies and intraspecies differences was applied to calculate the TDI. According to the evaluation results, a TDI of BPA for Korean was suggested at 0.05 mg/kg bw/day. In addition, the BPA exposure level based on food consumption by the Korean population was estimated as 1.509 ${\mu}g/kg$ bw/day, and the HI was evaluated at 0.03 when the TDI of 0.05 mg/kg bw/day was applied. This HI value of 0.03 indicated that hazardous effects would not be expected from BPA oral exposures. Although highly uncertain, further studies on low dose neurobehavioral effects of BPA should be performed. In addition, it is recommended that the 'as low as reasonably achievable' (ALARA) principle be applied for BPA exposure from food packaging materials in newborn infants and children.

• 모자간호학회지
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• v.2 no.1
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• pp.70-86
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• 1992

What is the meaning of menopause experienced by urban Korean women? Nurses need an under standing of menopause as it is experienced by women themselves. Nursing needs to build knowledge of womens' health experiences. This phenomenological study examined what menopause means to modern Korean woman to build a structure of knowledge useful for practice to enhance the quality of life of women throughout this experience. Traditional definition of menopause according to physiological changes, as illness and more recently as psychosociocultural phenomena were examined along with the folk lore information generally available in the society A review of the research and scientific literature was done from the perspectives of four models including the medical model of menopause as disease, the psychosocial model as positive and negative behavioral responses to menopause, a feminist model of menopause as a time of rebirth and a nursing model of the changing patterns of meaning, rythms and transformation women experience through menopause. Van Kaam's method was used to analyse data audio-recorded during interviews by the investigator with 65 women, 40 to 60 years of agey whose confidentility was assured. Interpretation of the data was enhanced luther by consultation with professional colleugues and with informants. Four rhythmical patterns of process emerged : from suffering to comfort, from oppression to freedom from being a good wife and wise mother to becoming a woman and from a hard life to an abundant life. The detailed common elements making up each of the four patterns and definitions of each pattern were presented. Each pattern was discussed critically from the point of view of medical, psychosociocultural, womens' and nursing models. The structural definition of the synthesis of the four process patterns was stated as : in spite of suffering the middle-aged urban Korean woman find she is able to help herself to feel comfortable and to realize release as she moves from oppression to liberation and freedom from being a good wife and wise mother she experiences rebirth as a woman : she begins to live a profitable and valuable life : her life becomes one of transformed abundant living. The definition transcends the medical and phychosociocultural model to embody a nursing model. The analysis was critiqued by using Parse' Human Becomming theory of nursing because the emerging themes were process patterns. Parse' theory provides and explanation of the experience of menopause consistant with the data which enhances nursing understanding of womens' experience of menopause. Parse' practice methodology provide guidance for promoting womens' quality of life throughout the experience of menopause. Feminist analysis contributes valuable critique to nursing research, richly expanding the perspective from traditional approaches to promote understanding of the meaning of womens' health experiences.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.5
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• pp.35-41
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• 2008

This paper presents the design method of current-mode signal processing for high speed and low power digital audio signal processing. The digital audio processor requires a digital signal processing such as fast Fourier transform (FFT), which has a problem of large power consumption according to the settled point number and high speed operation. Therefore, a current-mode signal processing with a switched Current (SI) circuit was employed to the digital audio signal processing because a limited battery life should be considered for a low power operation. However, current memory that construct a SI circuit has a problem called clock-feedthrough. In this paper, we examine the connection of dummy MOS that is the common solution of clock-feedthrough and are willing to calculate the relation of width between dummy MOS for a proposal of the design methodology for improvement of current memory. As a result of simulation, in case of that the width of memory MOS is 20um, ratio of input current and bias current is 0.3, the relation of width between switch MOS and dummy MOS is $W_{M4}=1.95W_{M3}+1.2$ for the width of switch MOS is 2~5um, it is $W_{M4}=0.92W_{M3}+6.3$ for the width of switch MOS is 5~10um. Then the defined relation of MOS transistors can be a useful design guidance for a high speed low power digital audio processor.

• Journal of Elementary Mathematics Education in Korea
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• v.20 no.3
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• pp.431-456
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• 2016

The purpose of this study is to investigate the appropriate time of introduction and the usage of the number line, in order to suggest the right point of learning the number concept to the elementary school students. For the efficient achievement of this purpose, we investigated the mathematical models for constructing the number concept such as number line, empty number line and double number line, counting and development of number concept. Then, we conducted case study on the time of introduction and the usage of the number line. Finally, we analyzed the result. First, there is need for adjustment to conduct the introduction of the number line from the second year of elementary school, so to help the students understand the continuing number concept through the understanding on the metaphorical concept of the number line. Second, there is the need of positive introduction and the use on the mathematical models; empty number line which helps to draw various thinking strategy visually through the process of operations such as addition and subtraction; the division into equal part and division by equal part in which multiplicative comparative situation or division takes place; the double number line which helps to understand the rate or proportional distribution. Finally, when adopting the number line, the empty number line, or the double number line, we suggested the necessity of learning about elaborate guidance and the usage in order to fully understand the metaphorical concept of the number line.

• Education of Primary School Mathematics
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• v.23 no.3
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• pp.135-156
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• 2020

The purpose of this study is to analyze the effect of average unit learning on the knowledge of the representative value of 5th grade elementary school students. In the information-oriented society, the ability to organize and summarize the data has become an essential resource. In the process of correctly analyzing statistical data and making reasonable decisions, the summary of the data plays an important role, and it is necessary to learn the concept of representative values in order to describe the center of the data in a series of numbers. For research, an informal knowledge type possessed by a fifth grade elementary school student with respect to a representative value before learning an average unit is examined and compared with the representative value after learning the average unit. A suggestion point for representative value guidance in school mathematics is provided while examining the change in knowledge with respect to the representative value. Seeing the informal types of elementary school students' representative values will help them learn how to formalize the concept of representative values in middle and high schools. It will give suggestions about the concept of representative values and the method of instruction that should be dealt with in elementary schools. The informal knowledge about the representative value can help with formal representative value that will be learned later. Therefore, This study's discussions on statistical learning of elementary school students are expected to present meaningful implications for statistical education.