• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.3
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• pp.233-244
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• 2014

Precise Point Positioning (PPP) is an increasingly recognized precisely the GPS/GNSS positioning technique. In order to improve the accuracy of PPP, the error sources in PPP measurements should be reduced as much as possible and the ambiguities should be correctly resolved. The correct ambiguity resolution requires a careful control of residual errors that are normally categorized into random and systematic errors. To understand effects from two categorized errors on the PPP ambiguity resolution, those two GPS datasets are simulated by generating in locations in South Korea (denoted as SUWN) and Hong Kong (PolyU). Both simulation cases are studied for each dataset; the first case is that all the satellites are affected by systematic and random errors, and the second case is that only a few satellites are affected. In the first case with random errors only, when the magnitude of random errors is increased, L1 ambiguities have a much higher chance to be incorrectly fixed. However, the size of ambiguity error is not exactly proportional to the magnitude of random error. Satellite geometry has more impacts on the L1 ambiguity resolution than the magnitude of random errors. In the first case when all the satellites have both random and systematic errors, the accuracy of fixed ambiguities is considerably affected by the systematic error. A pseudorange systematic error of 5 cm is the much more detrimental to ambiguity resolutions than carrier phase systematic error of 2 mm. In the $2^{nd}$ case when only a portion of satellites have systematic and random errors, the L1 ambiguity resolution in PPP can be still corrected. The number of allowable satellites varies from stations to stations, depending on the geometry of satellites. Through extensive simulation tests under different schemes, this paper sheds light on how the PPP ambiguity resolution (more precisely L1 ambiguity resolution) is affected by the characteristics of the residual errors in PPP observations. The numerical examples recall the PPP data analysts that how accurate the error correction models must achieve in order to get all the ambiguities resolved correctly.

• Child Health Nursing Research
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• v.3 no.2
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• pp.178-189
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• 1997

This study was done to compare the breast-feeding primiparas' perceptions of their babies with bottle-feeding primiparas' at 2-3 days after delivery. The subjects of this study included 42 breast-feeding mothers and 56 bottle-feeding mothers. Data were collected by using the Neonatal Perception Inventory(NPI) devised by Broussard (1963) and added by Lee, Ja Hyung(1986) from December, 1996 to June, 1997. The results of this study are as follows, 1. Primiparas' perceptions of their babies according to their general characteristics. 1) There was no significant difference in mothers' perceptions according to mothers' age and whether they have a job or not. 2) There was a difference in mothers' perceptions according to their educational level (P<0.1). 2. The comparisons of breast-feeding mothers' perceptions of their babies with bottle-feeding mothers'. 1) There was no significant difference in the two groups' perceptions of other babies 2) There was no significant difference in the two groups' perceptions of their own babies. (1) Breast-feeding mothes' general perceptions of their own babies were better than bottle-feeding mothers', but there was no significant difference between the two groups. (2) Breast-feeding mothers' perceptions about the basic needs of their own babies were better than bottle-feeding mothers', and there was a significant difference between the two groups (P<0.05). (3) Breast-feeding mothers'perceptions about the sense and motor abilities of their own babies were better than bottle-feeding mothers', but there was no significant difference between the two groups. (4) Breast-feeding mothers' perceptions about the necessary care of their own babies were lower than bottle-feeding mothers', but there was no significant difference between the two groups. 3) There was no significant difference between the two groups' positive-negative perceptions of their babies (1) 69% of breast-feeding mothers and 69.9% of bottle-feeding mothers had positive perceptions about general conditions, but there was no significant difference between the two groups (2) 57.1% of breast-feeding mothers and 46.4% of bottle-feeding mothers had positive perceptions about the needs of babies, but there was no significant difference between the two groups. (3) 50% of breast -feeding mothers and 48.2% of bottle-feeding mothers had positive perceptions about the sense and motor abilities of babies, but there was no significant difference between the two groups. (4) 57.1% of breast-feeding mothers and 60.7% of bottle-feeding mothers had positive perceptions about the necessary care for babies, but there was no significant difference between the two groups. 3. 54.8% of breast-feeding mothers tried to feed their own babies on the 1st day after delivery. 83.3% of breast-feeding mothers chose the feeding method for themselves. Only 9.5% of breast-feeding mothers took recomendations for breast-feeding from nurses. 78.6% of breast-feeding mothers had no chance to learn about breast-feeding. 69% of breast-feeding mothers complained about the difficulties of breast-feeding. The most serious problems were : 'insufficient milk supply', 'lack of knowledge about feeding technique' and 'problems with nipples'.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.31 no.3
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• pp.101-124
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• 2020

Plan S is a policy that mandates research papers supported by specific funders such as the European Community be published in open access journals. The funder supports APC to researchers, providing a chance to advance the era of gold open access, and is expected to bring significant changes to the scholarly publishing ecosystem. This study explored the impact of Plan S from the perspective of each stakeholder of the scholarly publishing ecosystem, such as funders, academic societies or publishers, authors, and libraries, through a review of previous studies. In addition, the status of Korean gold open access publishing and position for each stakeholder were identified through the collected data analysis. As a result of the analysis, the share of publishing gold open access journals in Korea was 22%, which was less than 26% worldwide. Korean funding agencies were predicting and preparing for the impact of Plan S. On the other hand, Korean academic societies produce about 70% of all papers, but there are not many open access papers except medicine (51%). The response of the Korean library was not sufficient, and it contrasted with the activities of librarians in the U.S. that actively provide research support services based on the research lifecycle. It was suggested that Korean libraries should also actively try to change the role of librarians; advising researchers to plan open access publishing in grant project applications, consulting on copyrights, and so on. This study identified the background, principles, and impact of Plan S policy that would be effective in 2021 and examined the response situation in Korea. This study is valuable in that it served as the necessary basis for revitalizing the academic publishing ecosystem in Korea.

• Journal of Korean society of Dental Hygiene
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• v.2 no.2
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• pp.145-158
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• 2002

This is a section study for research of main cause and coping ways caused by stresses during the clinical experiment. It was researched by 231 students of third grade have finished clinical experiment until September though questionnaire. The methods for this study used the a stress measuring instrument thai was used by Hoa-Yun Jun and coping ways of stresses devised by Bell. We computed the frequency and the mean value by the SPSS 10.0 statistical data and we got the following result that from the experiment with t-test and the ANOVA analysis. 1. The mean value of stresses indicated rather higher states in figures 2,855 and the figures that were classified by each areas, indicated highest figures are affected by circumstances, that is 3.065. 2. As higher as the degree of satisfactions in their major, students feel stress less so, the result was not quite different between each of them (p=0.007). 3. The copping ways of stresses indicated, similar differences by using of long-term copping ways and short-term copping ways to cope with stresses(p=0.000). 4. In case of the students who failed college entrance exams and prepared for the next chance for more than one year, indicated highest figures that is 2.57 in short-term ways to cope with stresses, so it showed slightly differences between them(p=0.014). 5. According to the satisfactions of clinical experiments, there were not any statistical differences in long-term coping ways but, as smaller as the satisfactions, in that evidence of the students use short-term copping ways, it showed slightly differences between them(p=0.041). 6. According to the degree of stresses, low-stress groups use short-term coping ways more than high-stress groups, so it showed slightly differences between them(p=0.001). 7. As far as the using of long-term coping ways, the figures of between the lower stress groups and the higher stress groups indicated 2.89 and 2.97 respectably so, the figures were not so closed.

• Korean Journal of Social Welfare
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• v.59 no.3
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• pp.147-174
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• 2007

This study examines how path dependency of working poor labor market segmented from the primary and the secondary labor market affects employment and quality of employment of working poor. It Further examines how path dependency makes working poor to remain in the labor market and makes it difficult for them to escape from a vicious poverty cycle. Data is based on the $3{\sim}7th$ Korea Labor and Income Panel Study(KLIPS). Markov's transition probability and discrete-time hazard analysis are used for analysis. This study finds that Korea labor market is divided into three parts; the primary labor market, the secondary labor market and the working poor labor market. The proportion of employed poor has been reduced, but the proportion of non economically-active working poor has been increased and has become the main group among the working poor. This shows that labor demand of working poor is fundamentally lacking and there are structural barriers that block working poor's employment itself. The regression analysis shows that the longer working poor labor market participation is, the lower poverty-exit rate. This is an evidence of vicious poverty cycle that the poor have little chance to exit from working poor labor market, once they step into it. Therefore, the longer their participation in poor labor market, the more likely they would move only within the closed working poor labor market. Consequently, it is necessary to fundamentally reform labor market structure and to alleviate negative perception and discrimination about the poor labor while activating labor demand.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.2 no.1
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• pp.7-18
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• 1995

This study was designed to explore the effectiveness of education to improve self-care of stroke patients with three types of charactor health locus of control and constitution. A total of 56 patients were selected by convenience sampling at one oriental hospital. The teaching of self-care was conducted by the researcher. The self-care performance was measured for 10 days. The data were analyzed using t-test, ANOVA and Scheffe method as post hoc test. The results of this study are as follows : 1. The self-care performance by patients' characteristics : Age and education had impact on the self-care performance. The level of self-care performance of young and high educated patients was high, gender, religion, occupation, monthly income, and the paralyzed side, however, didn't have influence on the self-care performance. 2. The self-care performance of patients with three types of constitution : There was no statistical significance on the self-care performance of patients group by constitution. However, average score of self-care performance of patients with So-Um was high. 3. The self-care performance of patients with three types of health locus of control : There was no statistical significance on self-care performance of patient group by health locus of control. 4. The correlation between the constitution and the health locus of control : There was no statistical significance on the introverted and chance health locus of control of patients with three types of constitution. However, there was a statistically significant relationship between the powerful others health locus of control and So-Yang. Even though there was no statistically significant self-care performance of patients with So-Um, there was a clinical significance on the high score of self-care performance of patients with So-Um as compared with the self-care performance of the patients. The health locus of control didn't have influence on the self-care performance of patients. There was a statistically significant relationship between the powerful others health locus of control and So-Yang. Therefore, this study suggest the need to develop the nursing intervention to improve the self-care of stroke patients with the powerful others health locus of control and So-Yang, Furthermore, the longitudinal research is needed to determine the effectiveness of training to imp

• Journal of Preventive Medicine and Public Health
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• v.30 no.3 s.58
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• pp.643-664
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• 1997

This study is to provide evidence-based recommendations for the most-effective treatments of benign prostatic hyperplasia based on patient preference or clinical need, and to meta-analyze the Korean literatures for the development of BPH treatment guidelines. For these analyses, extensive literature searches (208 articles), with priority given to the Korean Journal of Urology, were conducted from 1960 to August, 1996. Meta-analysis, like all statistical analysis, has two main functions: data summarization (qualitative meta-analysis) and smoothing o. pattern recognition (quantitative meta-analysis). As well, critical reviews and syntheses with the mean and 90-percent confidence intervals for the likelihood were used to evaluate empirical evidence and significant outcomes of the BPH treatment literatures (106 articles). For this task, the Methodologic Panel for BPH Guidelines was composed of multidisciplinary experts in the field. The results of the study were summarized as follows: For all that watchful waiting is an appropriate treatment strategy for the majority of patients with prostatism, we couldn't find the Korean literatures which carried this article. The literatures on alpha-1-adrenergic receptor blockers provide no evidence to suggest that any one alpha blocker is more effective than another. The finasteride reduces the size of the prostate, on average, and leads to a small yet perceptible reduction in sysptoms. Of all treatment options, prostate surgery with transurethral resection of the prostate (TURP), transurethral incision of the prostate (TUIP), and so on, offers the best chance for symptom improvement. However, surgery also has the highest rates of significant complications. Therefore, surgery need not always be a treatment of last resort. Balloon dilation of the prostatic urethra is clearly less effective than surgery in relieving symptoms, but it is associated with fewer complications. Emerging technologies for treating BPH include lasers, coils, stents, thermal therapy and hyperthermia. Established technologies will also be reanalyzed as results of new trials are reported. Although this study has some limitations due to lacking for good quality literatures, ' it provides a cornerstone for our medical research. It represents the most current scientific knowledge regarding the clinical epidemiology including treatment of BPH. It will be revised and updated as needed.

• Information Systems Review
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• v.15 no.3
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• pp.111-128
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• 2013

Conventions play important roles as tools for effective marketing. It will be able to understand the changes of particular industry's market, develop a new market and potential clients, and get a chance such as strategic network constructing. To support effective viewing of visitors, conventions have introduced a variety of ubiquitous computing technologies. This study introduces a case of applying the Utility Tag-based convention service system at the Cosmetics & Beauty Expo, Osong Korea 2013. The Utility Tag-based convention service system is constructed total three systems: (1) NFC Tag Management System; allowing effective access and management of NFC tags in various locations and objects, (2) Information Provide System; allowing participating vendors to manage information they want to provide information to visitors, and (3) Utility Tags; providing a variety of service to visitors for effective viewing in exhibition/convention space. This study first explores literature review and applying case related to ubiquitous computing in this field and introduces Applying an Utility Tag-based convention service system. In addition, we analyze visitors' behaviors and association rules by take advantage of collected touch data, present various possible for applications of the Utility Tag-based convention service system.

• Restorative Dentistry and Endodontics
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• v.27 no.4
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• pp.382-388
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• 2002

Compomer is composed of matrix and filler : matrix is made of the combination of resins and polycarboxylic molecules that are light-cured, and a filler is a glass component which is capable of ion-release. The resin content of compomers produces polymerization shrinkage which can adversely affect marginal adaptation. Pretreatment is a fundamental step which is treated with conditioner or primer in the use of these materials. Microleakage of restorative materials has been investigated mostly by dye penetration method. Dye penetration method was not quantitative and not measured repeatedly. Fluid filtration method, introduced and developed by Pashley's group, has been extensively used for 20 years for research purpose to understand the physiology of dentin, as well as the effects of various restorative treatments on dentin permeability. It permits quantitative, nondestructive measurment of microleakage in a longitudinal manner. The purpose of this study was to evaluate the change of dentin permeability according to the process of compomer restoration. In this study. Cl V cavities were prepared on buccal surface of thirty extracted human molars. The prepared cavities were etched by 37% phosphoric acid. The experimental teeth were randomly divided into three groups. Each group was treated with following materials Group 1 : Prime & Bond NT/Dyract AP, Group2： Single Bond/F2000 compomer, Group 3 : Syntac Single Component/Compoglass. The bonding agent and compomer were applied for each group following manufacturers information. Dentin permeability of each group was measured at each process by fluid filtration method; Step 1 : preparation(smear layer). Step 2 : etching(smear layer removal), Step 3 : applying the bonding agent, Step 4 : filling the compomer. Dentin permeability was expressed by hydraulic conductance ($\mu\textrm{l}$ min$^{-1}$cm$H_2O$$^{-1}$). The data were analysed statistically using One-way ANOVA and Sheffe's method. The results were as follows : 1. Dentin permeability differences between each process were significant except between step 1 and step 2(p<0.01). 2. Dentin permeability after removal of smear layer was highly increased(p<0.01). 3. In most case, decrease of dentin permeability was obtained by applying bonding agent(p<0.01). 4. Dentin permeability differences among the experimental groups were not significant(p>0.05). 5. None of compomers used in this study showed perfect seal at the interface.

• Journal of the Korean Geophysical Society
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• v.1 no.1
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• pp.41-50
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• 1998

Schlumberger soundings, dipole-dipole survey and electrical conductivity mappings were carried out inside and in front of the entrance of the Okmyung waste landfill in August, 1997 and January, 1998. Inside and in front of the landfill, 11 and 4 electrical soundings and 1 dipole-dipole survey were carried out, respectively. Electrical conductivities were measured at 164 points along the 4 lines in front of the entrance of the landfill. Interpretations of survey data show that low resistivity zones of 0.3∼3 Ωm extend down to 65 m depth from the surface in the 6th landfill, which indicates subsurface contamination by leachate and leachate level at 3∼6 m depth from the surface. In the 9th landfill, low resistivity zones below 2 Ωm appear at 11∼15 m depth from the surface, which indicates a very slim chance of subsurface contamination. On the other hand, electrical surveys and electrical conductivity mappings reveal low resistivities at shallow depths in front of the entrance of the landfill, indicating a high possibility of contamination of weathered zone in this area. It appears that southern part of this area close to the 6th landfill is more contaminated by leachate.