• Communications of Mathematical Education
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• v.23 no.2
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• pp.327-347
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• 2009

The purpose of the present study is to investigate the effects of mathematical communication-centered teaching using peer feedbacks on students' mathematics achievement and mathematical dispositions toward mathematics, and then this study examined the characteristics of feedbacks used by students. To do this study, two sixth grade classes selected from an elementary school in Seoul participated in the current study; one class for a treatment group applying mathematical communication-centered teaching using peer feedback, and the other for a comparison group applying traditional teaching using teacher-centered communication. The results of this study showed the fact that a treatment group of mathematical communication-centered teaching applying peer feedback scored statistically higher than a comparison group applying teacher-centered communication with respect to both students' mathematical achievement and disposition. Especially, this communication-centered teaching program focused on peer feedback was more effective to middle or lower level students than higher level students. In addition, mathematical communication-centered teaching applying peer feedbacks helps students reflect their own thinking process about problem solving, and students experienced the improvement of their confidence about mathematics from opportunities to provide peers with feedbacks. Finally, the present study suggests the important role of communication in mathematics learning, particularly student-to-student feedbacks rather than teacher-to-students feedbacks. That is to say, students need to have many opportunities to represent their own mathematical thinking processes using mathematical language.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.4
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• pp.382-389
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• 2017

Currently, reticulocyte experimental calculation technology used in clinical laboratories are divided two types: manual and automated. Manual reticulocyte counting using a microscopy lacks accuracy due particularly to its low reproducibility, affecting the accuracy of manual reticulocyte count. Moreover, Automatic blood corpuscle analyzer flow cytometry is difficult to be used in underdeveloped countries and small scale laboratories due to relatively high cost. Therefore, this study tried to find a new method to complement these drawbacks. The aim of this study was to compare the stained reticulocytes count by spectrophotometer and also to analyze the statistics of spectrophotometer and flow cytometer. The same 8 EDTA samples were repeated 36 times to compare the agreement between spectrophotometer and flow cytometer. This study measured the specimen diluted 600 times at 700~780 nm by 10 differences. Wavelength between 710 to 730 by absorbance showed a positive correlation between standard data and test data (r=0.967, p<0.01), presenting a correlation between variables. Statistical analyses of regression for test and standard parametric data, the optimal dilution factor was 600 times. Therefore, this study tried to technical utilizes such as contributing economical for the reticulocyte absorbance apply from the auto spectrophotometer, a monitoring system for the reticulocyte relation anemia, etc. Therefore, more extensive studies, including an auto chemical analyzer application, will be needed.

• Journal of the Korean Regional Science Association
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• v.32 no.2
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• pp.45-59
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• 2016

The purpose of this study is to analyze the static and dynamic change of wage differentials of women with disabilities in the Seoul local labor market. This study attempts to explain the double discrimination mechanism for disabled women and empirically gender discrimination and disability discrimination for them by using Oaxaca-Blinder decomposition analysis. In addition, using Juhn-Murphy-Pierce decomposition analysis. we analyze the wage differentials caused by the changed characteristics of disabled women and structures of discrimination at the Seoul local labor market. Data from the Panel Survey of Employment for the Disabled and Korean Labor and Income Panel Study for two years (2008, 2012) are used. According to the result, wage differentials of disabled women caused by disability discrimination is approximately 55% of total wage discrimination, whereas 45% is caused by gender discrimination during the period. Both observed and unobserved components move in the same direction to narrow wage differentials due to the disability discrimination and gender discrimination. Also the endowments in the Seoul local labor market about the changes of observed and unobserved components contribute more to narrow gender wage differentials, while these endowments widen disability wage differentials.

• Pediatric Infection and Vaccine
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• v.13 no.2
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• pp.180-185
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• 2006

Invasive Pseudomonas infections most often occur in the immunocompromised patients and are associated with high mortality rate. Rarely this disease may develop in healthy infants and children. We report two cases of invasive Pseudomonas aeruginosa infections that were diagnosed in otherwise healthy infants. The first case was a previously healthy 5-month-old infant with ecthyma gangrenosum and septicemia. She presented with fever, swelling of left periorbital area and multiple erythronodular skin lesions. Each skin lesion formed a black eschar surrounded by an erythematous areola over time. Cultures of blood, urine and discharge from skin lesions grew P. aeruginosa. On the day of visit, she showed pancytopenia which was normalized after 10 days. The patient responded well to the management with ceftazidime and tobramycin. The other case was a previously healthy 9-month-old infant with community-acquired pneumonia. He was referred from an outside hospital with fever and cough. Chest x-ray revealed pneumonic infiltrations on both lower lungs with pleural effusion on the right side. Cultures of blood and pleural fluid grew P. aeruginosa. Chest CT performed on the ninth day demonstrated pneumatoceles, lung abscess and necrosis of lung parenchyma. He was managed with ceftazidime and amikacin for 50 days. No residual pulmonary complications were noted during the three month follow-up. Laboratory results to evaluate immunologic defects of phagocytic cells, complement components and T- and B-lymphocytes were all within normal range in both patients. It should be kept in mind that Pseudomonas can be, though uncommon, a cause of community-acquired invasive infections in the previously healthy infants.

• Journal of Preventive Medicine and Public Health
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• v.24 no.1 s.33
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• pp.93-97
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• 1991

The time honoured tuning fork at present widely available for examining vibration sensation is brought about the problem of great interobserver variation. To resolve t his problem, author developed a divice using electric magnet that stimulates constantly tuning fork. The perception time of vibration from tunung fork by this device was tested on the index finger of dominant hand of twenty eight subjects. It was 12.44 seconds on average and ranged from 9.47 to 17.25. Coefficient of variation of it was 16.89 percent. Correlation coefficient between test and retest after 30 minutes was 0.957(p<0.01). This device is portable. Test procedure in non-invasive, non-aversive and simple, can be performed within one minute, and does not require the skilled technician. It is felt that this device testing vibration perception time is suitable as screening tool for early detection of occupational peripheral neuropathy.

• International Journal of Highway Engineering
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• v.10 no.3
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• pp.57-68
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• 2008

The stabilization techniques in the pavement foundations have advantages in increasing pavement performance and reducing pavement thickness. By mixing the geomaterials and stabilizer, the economical and structurally sound layer can be added in the pavement system. Until now, these techniques have been applied in the field empirically and the design criteria for stabilization has not been established. The purposes of this paper are to evaluate the mechanistic properties of stabilizers used for geomaterials and determine the type and optimum amount of stabilizer for each technique. The unconfined compressive testing and repeated load resilient modulus test were conducted on the coarse grained soils mixed with various types of stabilizer to investigate the strength and deformation characteristics of stabilized geomaterials. It is found from the test that the unconfined compressive strength of stabilized geomaterials is more than ten times higher than that of gradation modified geomaterials. The resilient modulus of stabilized geomaterials increases by $6{\times}10$ times compared to the original soils and tends to increase with increase of volumetric and deviatoric stress, and amount of stabilizer.

• Journal of radiological science and technology
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• v.33 no.2
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• pp.85-91
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• 2010

Digital radiography has been replacing rapidly the analog radiography for diagnosis of pneumoconiosis. The purpose of this study is to compare quality control of digital radiography (DR) and analog radiography (AR) for chest radiography in medical institution for pneumoconiosis (MIP) For the first time, we visited MIP to evaluate the chest radiography which is used for patients with pneumoconiosis, including equipment, technical parameters and reading environment. There were 33 institutions. DR and AR were installed in 24 and 9 institutions, respectively. Between DR and AR, we compared the radiological technique (RT), image quality (IQ) and reading environment (RE) to use the guideline published by Occupational Safety and Health Research Institute (OSHRI). The image quality was rated by two experienced chest radiologists for pneumoconiosis with certified from OSHRI. The chest radiography equipment was not significantly difference between AR and DR, but there were significantly difference in tube voltage and grid ratio used for chest radiography except to tube current, exposure time. Statistically, DR is significantly higher in RT(70.3 vs. 43.8, p = 0.009), RE(77.7 vs. 33.3, p = 0.004) than AR, but it's not significantly difference in IQ (65.6 vs. 52.8, p = 0.050). AR and DR in RT were passed 33.3%, 75.0% respectively (p = 0.044) and 44.4%, 79.2% (p = 0.090) in IQ and 44.4%, 91.7% (p = 0.009) in RE. In MIP, DR needs to replace AR in diagnosis of pneumoconiosis.

• Journal of radiological science and technology
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• v.39 no.3
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• pp.429-434
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• 2016

This study was performed in order to identify the relation between bone nineral density and life styles of some of Korean colleage students. A total of 121 college students were assessed through bone mineral density test on femoral neck and lumbar spine using dual energy X-ray absorptiometry(DEXA). The survey about their lifestyles with a self-rating questionnaire, was conducted from September 2014 to November 2014. SPSS 18.0 Program was used for those research data analyses such as the frequency analysis, the cross analysis. The percentage of the osteoporisis, osteopenia and normal groups were 0.0%, 24.8% and 75.2%. BMI, Regular menstrual cycle, Walking and Regular exercise in adolescence were positively related with T-score. But Using time of electronic devices was negative related with T-score. It can be concluded that desirable life style in time of college students and adolescence is important for their bone health. The necessity of preparing guideline for preventing bone disease in old age connected with the school curriculum should be recognized to the public and educational authorities.

• Korean Security Journal
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• no.17
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• pp.109-129
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• 2008

The purpose of this study is to analyze the relationship of market orientation, and business performance in the security firms. To achieve the goal of the study, it has used various methods to study. First of all, it has carried out documentary surveys through literatures review on market orientation and business performance of the security firms, and practical researches side by side. In the documentary surveys, it has developed the framework of study and questionnaires based on the domestic and foreign books, theses, materials of public institutions, and other materials. In the practical researches, basing on the selected study models and hypotheses, it has selected 15 security companies which are located in Seoul, Gyeonggi and Chungcheong Provinces with the stratified cluster random sampling method. It has polled the employees of the security companies for about 2 months from 5 August to 10 October 2006, distributing 20$\sim$50 pieces per company. It has distributed 600 pieces and used 565 pieces for analysis excepting unfaithful 35 pieces. The collected questionnaires were analyzed by SPSSWIN 14.0 program. and The methods to analyze the materials were factor analysis, reliability analysis, correlation analysis, multiple regression analysis, and path analysis through regression analysis. The results obtained from the study using analysis methods above are as follows. Finally, market orientation influences on business performance. In other words, the higher market orientation is, the better financial and non financial outcomes are.

• Journal of Korean Society of Transportation
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• v.35 no.5
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• pp.434-446
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• 2017

This study was carried out to suggest new indicators to be used at airports. Generally, passengers and cargo will be handled at the airport, and the airport will achieve revenues through them. However, all airports can not have the same distribution of passenger and cargo throughput. When comparing and analyzing several airports, a uniform result can be expected only if a unit airport throughput indicator is applied. The 'Work Load Unit' is an indicator that integrates passengers and cargo into one, and assumes that the value of one passenger is equivalent to the cargo volume of 100kg. The existing WLU was set up based on the experience at the airport rather than being established through reasonable grounds or analysis, so there was a lot of controversy. The purpose of this study is to overcome these limitations and to suggest new index. In this study, we applied a method to compare the relative value of cargo and passenger to airport revenue. In order to analyze cargo value and passenger value, airport revenues are classified into aircraft operation related revenues, passenger handling related revenues, and commercial revenues. A total of 50 airports were selected, including 14 airports in Asia, 18 airports in Europe and 18 airports in North America. According to the final analysis results, it is concluded that the cargo is equivalent to 280kg of cargo based on the contribution of one passenger averagely. This is higher than the value of 100Kg cargo per passenger.